Experimental and theoretical investigation of fatigue life in reusable rocket thrust chambers

During a test program to investigate low-cycle thermal fatigue, 13 rocket combustion chambers were fabricated and cyclically test fired to failure. Six oxygen-free, high-conductivity (OFHC) copper and seven Amzirc chambers were tested. The failures in the OFHC copper chambers were not typical fatigue failures but are described as creep rupture enhanced by ratcheting. The coolant channels bulged toward the chamber centerline, resulting in progressive thinning of the wall during each cycle. The failures in the Amzirc alloy chambers were caused by low-cycle thermal fatigue. The zirconium in this alloy was not evenly distributed in the chamber materials. The life that was achieved was nominally the same as would have been predicted from OFHC copper isothermal test data

Calculations of economy of 18-cylinder radial aircraft engine with exhaust-gas turbine geared to the crankshaft

Calculations based on dynamometer test-stand data obtained on an 18-cylinder radial engine were made to determine the improvement in fuel consumption that can be obtained at various altitudes by gearing an exhaust-gas turbine to the engine crankshaft in order to increase the engine-shaft work

An Empirical Study of Scoring Methods for the Conover Driving Attitude Inventory

The measurement of driving attitudes has followed in the wake of various studies and statistical data indicating that improper attitudes are responsible for an unduly high percentage of accidents. Certain of these tests have limitations, one of which is an economical method of scoring. Conover (Conover, 1947) used a scoring method such that the values 0, 1, 2, 3, 4, are assigned respectively to the responses designated as; most displeasing, displeasing, indifferent, pleasing, and most pleasing, for the positive items, and to avoid negative scores the values 4, 3, 2, 1, 0, are assigned respectively to the same responses; most displeasing, displeasing, indifferent, pleasing, and very pleasing, on the negative items. Summing the positive items according to the values given and the negative items by the reverse scoring system, the score for an individual is obtained. The Conover Driving Attitude Inventory is designed to measure the attitudes of individuals toward factors shown to be important in safe driving. An individual\u27s attitude toward specific factors, as indicated by his response to the items of the scale may be considered to constitute his attitude toward safe driving in general. In other words it is a test of one\u27s reactions to everyday driving experiences while behind the wheel. One-hundred fifty items make up the scale, thirty-five of which are considered positive items, thirty negative, and the remaining eighty-five are considered as fillers

Self-protection in dry recycle technologies

In response to the INFCE conclusions, the U.S. undertook development of a new dry fuel cycle. Dry recycle processes have been demonstrated to be feasible. Safeguarding such fuel cycles will be dramatically simpler than the PUREX fuel cycle. At every step of the processes, the materials meet the {open_quotes}spent-fuel standard.{close_quotes} The scale is compatible with collocation of power reactors and their recycle facility, eliminating off-site transportation and storage of plutonium-bearing materials. Material diverted either covertly or overtly would be difficult (relative to material available by other means) to process into weapons feedstock

Supporting Online Learning for Advanced Placement Students in Small Rural Schools: Conceptual Foundations and Intervention Components of the Facilitator Preparation Program

This paper examines the need for interventions to support students who are taking advanced placement courses in small rural districts and describes the Facilitator Preparation Program (FPP) as a strategy to address this need. Issues in the delivery of Online Distance Education (ODE) in small rural schools are summarized and the conceptual foundations and service delivery considerations of the FPP are outlined. Future research needs are also considered

The benefits of an advanced fast reactor fuel cycle for plutonium management

The United States has no program to investigate advanced nuclear fuel cycles for the large-scale consumption of plutonium from military and civilian sources. The official U.S. position has been to focus on means to bury spent nuclear fuel from civilian reactors and to achieve the spent fuel standard for excess separated plutonium, which is considered by policy makers to be an urgent international priority. Recently, the National Research Council published a long awaited report on its study of potential separation and transmutation technologies (STATS), which concluded that in the nuclear energy phase-out scenario that they evaluated, transmutation of plutonium and long-lived radioisotopes would not be worth the cost. However, at the American Nuclear Society Annual Meeting in June, 1996, the STATS panelists endorsed further study of partitioning to achieve superior waste forms for burial, and suggested that any further consideration of transmutation should be in the context of energy production, not of waste management. 2048 The U.S. Department of Energy (DOE) has an active program for the short-term disposition of excess fissile material and a `focus area` for safe, secure stabilization, storage and disposition of plutonium, but has no current programs for fast reactor development. Nevertheless, sufficient data exist to identify the potential advantages of an advanced fast reactor metallic fuel cycle for the long-term management of plutonium. Advantages are discussed

Individual leader to interdependent leadership: A case study in leadership development and tripartite evaluation

This article is available open access through the publisher’s website at the link below. Copyright @ 2013 Sage Publications.The Problem - In this case study we see a move away from orthodox views of school leadership as “headship” to a more contemporary model of educational leadership wherein we note a departure from functional, curricula-based school leadership toward more human resource development (HRD) approaches. The aim of this study was to consider the effectiveness of an educational development program for middle leaders within an educational establishment. The Solution - We examined the impact of a bespoke higher education leadership development intervention in Leadership (and Change) on the formation and cohesiveness of a newly formed innovative leadership structure. The Stakeholders - The leadership development intervention was designed through a tripartite collaboration including a university, senior school leaders, and staff. The intervention was designed to shift leadership from individual leader agency to interdependent human leadership agency. Through tripartite evaluation we uncover leadership development praxis that transcends the boundaries of conventional educational leadership and reemphasizes the benefits of bridging the academic/practitioner divide and the application of theory to praxis

The practices of apartheid as a war crime: a critical analysis

The human suffering caused by the political ideology of apartheid in South Africa during the Apartheid era (1948-1994) prompted worldwide condemnation and a variety of diplomatic and legal responses. Amongst these responses was the attempt to have apartheid recognised both as a crime against humanity in the 1973 Apartheid Convention as well as a war crime in Article 85(4)(c) of Additional Protocol I. This article examines the origins, nature and current status of the practices of apartheid as a war crime and its possible application to the Israeli-Palestinian conflict

Doing more with less: Teacher professional learning communities in resource-constrained primary schools in rural China.

Teacher professional learning communities provide environments in which teachers engage in regular research and collaboration. They have been found effective as a means for connecting professional learning to the day-to-day realities faced by teachers in the classroom. In this article, the authors draw on survey data collected in primary schools serving 71 villages in rural Gansu Province as well as transcripts from in-depth interviews with 30 teachers. Findings indicate that professional learning communities penetrate to some of China’s most resource-constrained schools but that their nature and development are shaped by institutional supports, principal leadership, and teachers’ own initiative