Small Engine Component Technology (SECT) studies

A study was conducted to identify component technology requirements for small, expendable gas turbine engines that would result in substantial improvements in performance and cost by the year 2000. A subsonic, 2600 nautical mile (4815 km) strategic cruise missile mission was selected for study. A baseline (state-of-the-art) engine and missile configuration were defined to evaluate the advanced technology engines. Two advanced technology engines were configured and evaluated using advanced component efficiencies and ceramic composite materials; a 22:1 overall pressure ratio, 3.85 bypass ratio twin-spool turbofan; and an 8:1 overall pressure, 3.66 bypass ratio, single-spool recuperated turbofan with 0.85 recuperator effectiveness. Results of mission analysis indicated a reduction in fuel burn of 38 and 47 percent compared to the baseline engine when using the advanced turbofan and recuperated turbofan, respectively. While use of either advanced engine resulted in approximately a 25 percent reduction in missile size, the unit life cycle (LCC) cost reduction of 56 percent for the advanced turbofan relative to the baseline engine gave it a decisive advantage over the recuperated turbofan with 47 percent LCC reduction. An additional range improvement of 10 percent results when using a 56 percent loaded carbon slurry fuel with either engine. These results can be realized only if significant progress is attained in the fields of solid lubricated bearings, small aerodynamic component performance, composite ceramic materials and integration of slurry fuels. A technology plan outlining prospective programs in these fields is presented

Succession Planning Activities at a Rural Public Health Department

This qualitative case study utilized interviews and evaluation of publicallyavailable documents to investigate the process of succession planning in a moderately-sized public health office located in a metropolitan community in a frontier-rural state. Following analysis of the data, the results were compared to literature findings. Four public health directors, the County Health Officer and the Board of Health chairperson participated in the private, face-to-face interviews. These individuals were asked to participate because they have the ability to direct staff leadership development activities. A formal succession planning program did not exist at this agency; however, on an informal basis, leadership development was evident. Successes in promotion of leadership development included establishment of a cooperative and collegial work atmosphere. Barriers to the process of succession planning included a lack of stable funding, lack of understanding about the role of public health by the public, erosion of public health authority, inability to recruit trained personnel, low pay scales, and aging of the current workforce. The results of this study indicate that although formal succession planning programs may not exist within an agency, leadership development is still possible through proven adult education methods

Drama: A Comparative Analysis of Individual Narratives

In a narrative inquiry, five educators who taught college in prison share stories about working in this non-traditional learning environment that is often dangerous and frustrating. From the tension between the prison\u27s emphasis on social control and the educators\u27 concern for democratic classrooms, three broad themes emerged: working in borderlands, negotiating power relations, and making personal transformations. Large intact segments from transcripts of participant interviews form a dramatic text that illuminates how a selected group of educators made meaning of their experience teaching college courses to incarcerated students. A comparative analysis presented in a one act play brings together the individual participant voices to tell a collective story, which has meaning in the context of a shared emotional experience

On the Convergence of the Holistic Analysis for EDF Distributed Systems

Dynamic scheduling techniques, and EDF (Earliest Deadline First) in particular, have demonstrated their ability to increase the schedulability of real time systems compared to fixed-priority scheduling. In distributed systems, the scheduling policies of the processing nodes tend to be the same as in stand-alone systems and, although few EDF networks exist, it is foreseen that dynamic scheduling will gradually develop into real-time networks. There are some response time analysis techniques for EDF scheduled distributed systems, mostly derived from the holistic analysis developed by Spuri. The convergence of the holistic analysis in context of EDF distributed systems with shared resources had not been studied until now. There is a circular dependency between tasks’ release jitter values, response times and preemption level ceilings of shared resources. In this paper we present an extension of Spuri’s algorithm and we demonstrate that its iterative formulas are non-decreasing, even in the presence of shared resources. This result enables us to assert that the new algorithm converges towards a solution for the response times of the tasks and messages in a distributed system

Molecular Electroporation and the Transduction of Oligoarginines

Certain short polycations, such as TAT and polyarginine, rapidly pass through the plasma membranes of mammalian cells by an unknown mechanism called transduction as well as by endocytosis and macropinocytosis. These cell-penetrating peptides (CPPs) promise to be medically useful when fused to biologically active peptides. I offer a simple model in which one or more CPPs and the phosphatidylserines of the inner leaflet form a kind of capacitor with a voltage in excess of 180 mV, high enough to create a molecular electropore. The model is consistent with an empirical upper limit on the cargo peptide of 40--60 amino acids and with experimental data on how the transduction of a polyarginine-fluorophore into mouse C2C12 myoblasts depends on the number of arginines in the CPP and on the CPP concentration. The model makes three testable predictions.Comment: 15 pages, 5 figure