4,029 research outputs found
The Economic Basis of Social Class
In this paper we adopt a theory of class positions based on employment relations to assess what implications individuals¿ class positions have for their economic life. In particular we consider economic security (the risk of unemployment), economic stability (the variability component in earnings) and economic prospects (lifetime earnings profiles). Our findings provide empirical support for the theory itself and little evidence for the currently fashionable claims of the decline, or even death, of class in today¿s society.social class, relations and conditions of employment, lifetime earnings, employment stability, employment security
Coupled structural/thermal/electromagnetic analysis/tailoring of graded composite structures
Accomplishments are described for the third years effort of a 5-year program to develop a methodology for coupled structural/thermal/electromagnetic analysis/tailoring of graded composite structures. These accomplishments include: (1) structural analysis capability specialized for graded composite structures including large deformation and deformation position eigenanalysis technologies; (2) a thermal analyzer specialized for graded composite structures; (3) absorption of electromagnetic waves by graded composite structures; and (4) coupled structural thermal/electromagnetic analysis of graded composite structures
Turbine blade tip durability analysis
An air-cooled turbine blade from an aircraft gas turbine engine chosen for its history of cracking was subjected to advanced analytical and life-prediction techniques. The utility of advanced structural analysis techniques and advanced life-prediction techniques in the life assessment of hot section components are verified. Three dimensional heat transfer and stress analyses were applied to the turbine blade mission cycle and the results were input into advanced life-prediction theories. Shortcut analytical techniques were developed. The proposed life-prediction theories are evaluated
Keeping Secrets: The Unsettled Law of Judge-Made Exceptions to Grand Jury Secrecy
Federal Rule of Criminal Procedure 6(e) functionally binds everyone who is present during grand jury proceedings (except witnesses) to secrecy. But questions arise when courts are asked to make exceptions to grand jury secrecy outside those enumerated in the rule, such as exceptions for Congress or for the release of historically significant grand jury records.
This Note examines the propriety of judge-made exceptions to grand jury secrecy. Contrary to some courts authorizing disclosure outside of Rule 6(e), this Note argues that the text and development of Rule 6(e), along with limitations on courts’ inherent authority over grand jury procedure, caution against this practice. The tension between the current practice of some courts and the apparent meaning of Rule 6(e) renders the law of grand jury secrecy unsettled. To clarify the law, the Advisory Committee on Criminal Rules should add a residual exception to Rule 6(e) that would not only give courts flexibility and discretion but also a clear source of authority on which to authorize disclosures
Coupled structural/thermal/electromagnetic analysis/tailoring of graded composite structures
Accomplishments are described for the first year effort of a 5-year program to develop a methodology for coupled structural/thermal/electromagnetic analysis/tailoring of graded composite structures. These accomplishments include: (1) the results of the selective literature survey; (2) 8-, 16-, and 20-noded isoparametric plate and shell elements; (3) large deformation structural analysis; (4) eigenanalysis; (5) anisotropic heat transfer analysis; and (6) anisotropic electromagnetic analysis
Thermal barrier coating life prediction model development
This report describes work performed to determine the predominat modes of degradation of a plasma sprayed thermal barrier coating system and to develop and verify life prediction models accounting for these degradation modes. The primary TBC system consisted of a low pressure plasma sprayed NiCrAlY bond coat, an air plasma sprayed ZrO2-Y2O3 top coat, and a Rene' 80 substrate. The work was divided into 3 technical tasks. The primary failure mode to be addressed was loss of the zirconia layer through spalling. Experiments showed that oxidation of the bond coat is a significant contributor to coating failure. It was evident from the test results that the species of oxide scale initially formed on the bond coat plays a role in coating degradation and failure. It was also shown that elevated temperature creep of the bond coat plays a role in coating failure. An empirical model was developed for predicting the test life of specimens with selected coating, specimen, and test condition variations. In the second task, a coating life prediction model was developed based on the data from Task 1 experiments, results from thermomechanical experiments performed as part of Task 2, and finite element analyses of the TBC system during thermal cycles. The third and final task attempted to verify the validity of the model developed in Task 2. This was done by using the model to predict the test lives of several coating variations and specimen geometries, then comparing these predicted lives to experimentally determined test lives. It was found that the model correctly predicts trends, but that additional refinement is needed to accurately predict coating life
Community acceptance and implementation of HIV prevention interventions for injection drug users
In 1997, the National Institutes of Health (NIH) reviewed evidence of the effectiveness of HIV prevention programs for injection drug users (IDUs) and recommended that three types ofinterventions be implemented to prevent transmission of HIV among IDUs: 1) community-based outreach, 2) expanded syringe access (including needle exchange programs [NEP] and pharmacy sales), and 3) drug treatment. Progress on increasing the acceptance and feasibility of implementing these programs has been made at the national level, but their implementation has been varied at the local level.Understanding the conditions under which communities accept and implement interventions can help guide effective strategies to foster the implementation of these interventions in areas where programs do not currently exist
Thermal barrier coating life prediction model
The objectives of this program are to determine the predominant modes of degradation of a plasma sprayed thermal barrier coating system, and then to develop and verify life prediction models accounting for these degradation modes. The program is divided into two phases, each consisting of several tasks. The work in Phase 1 is aimed at identifying the relative importance of the various failure modes, and developing and verifying life prediction model(s) for the predominant model for a thermal barrier coating system. Two possible predominant failure mechanisms being evaluated are bond coat oxidation and bond coat creep. The work in Phase 2 will develop design-capable, causal, life prediction models for thermomechanical and thermochemical failure modes, and for the exceptional conditions of foreign object damage and erosion
Suicides Among Farmers in Three Southeastern States, 1990-1998
Several studies have documented higher rates of suicide among farmers in comparison to other occupational groups, both in the U.S. and internationally. The purpose of this study is to describe the epidemiology of farmer suicides in three southeastern states (Kentucky, North Carolina, and South Carolina) during the nine-year period 1990-1998. Electronic death certificate data were obtained from the National Center for Health Statistics. Over the nine-year period, there were 590 deaths related to suicide (E-codes: 950-959) among farmers (occupation codes: 473, 474, 475, 477, and 479) in the states of Kentucky, North Carolina, and South Carolina. The results of this study confirm the increased rate of suicide mortality among white male farmers in comparison to the total white male population in these three southern states. The increased rate of suicide was significantly elevated among farmers age 25-34 years (RR: 2.07; 95% CI: 1.61-2.67) and among those age 75-84 (RR: 2.04; 95% CI: 1.70-2.45) and age 85 years and older (RR: 2.67; 95% CI: 2.02-3.54) in comparison to the total white male population.The use of a firearm was the primary mechanism of death for the majority (86%) of the cases. Farmer suicide mortality rates in the southeastern U.S. are higher than in Midwestern states. The elevated rate of white male farmer suicides in North Carolina over this time period (35% higher age-adjusted suicide rate in comparison to South Carolina) suggests a need for further investigation to assess the individual, social, and economic factors that may explain this elevated rate. Interventions for the prevention of suicide need to be directed to older male farmers who consistently have higher suicide rates than similar males in other occupations
Designing evaluation for a high school research integrated learning outreach program
BACKGROUND
Educational outreach programs that bridge university and high school contexts aim to increase students’ engagement and commitment to STEM career pathways (Tytler et al., 2017). Likewise, opportunities for students to engage in authentic scientific research (research integrated learning, RIL) have also been demonstrated to develop STEM skills and lead to increased STEM identity and aspiration (Beier et al., 2018; Stets et al., 2017). Outreach programs may also support access to STEM pathways for students from diverse backgrounds (Scull & Cuthill, 2010). However, these positive outcomes cannot be assumed from program design alone. Rigorous evaluation is required to ensure that goals are being reached and to support iterative improvements in program design (Australian Academy of Science, 2019).
AIMS
This study presents the design and preliminary results of an evaluation of a high school outreach program, SciX (this intervention is described in another ACSME 2023 abstract by Laura McKemmish). The evaluation approach focuses on the program’s impact on students’ perceived scientific skills, science identity, and commitment to pursue a career in STEM. It also explores differences in these effects between demographic groups (girls, students from rural locations, students from low SES schools). Other program goals including sustainability, scalability, and a positive impact on teachers and mentors are also incorporated. The goal of this research is to support iterative improvement of the intervention and identify transferrable principles to enhance the effectiveness and equity of similar student research programs.
DESIGN AND METHODS
An evaluation framework was designed around a program logic model that also incorporated elements of motivation theory and identity theory. Student surveys (University of New South Wales Human Research Ethics approved) were administered immediately before and immediately following the one-week RIL summer school in 2021-2023. A total of 238 students completed a survey following the intervention.
RESULTS AND CONCLUSIONS
The full evaluation framework will involve mixed methods studies that incorporate survey and interview data from students, teachers, and mentors, as well as key informant interviews and program administration data. Preliminary results will be presented from student surveys. These results show positive experiences (73% of respondents were extremely happy they attended) and significant increases in science identity, which were greater for girls. Survey results also reveal the key importance of the student-mentor relationship to the experience, which will be further explored in later studies. Initial results have informed program design and future iterations of the evaluation research.
REFERENCES
Australian Academy of Science. (2019). Women in STEM Decadal Plan. www.science.org.au/womeninSTEMplan
Beier, M. E., Kim, M. H., Saterbak, A., Leautaud, V., Bishnoi, S., & Gilberto, J. M. (2018). The effect of authentic project‐based learning on attitudes and career aspirations in STEM. Journal of Research in Science Teaching, 56(1), 3-23.
Scull, S., & Cuthill, M. (2010). Engaged outreach: using community engagement to facilitate access to higher education for people from low socio‐economic backgrounds. Higher Education Research & Development, 29(1), 59-74.
Stets, J. E., Brenner, P. S., Burke, P. J., & Serpe, R. T. (2017). The science identity and entering a science occupation. Social science research, 64, 1-14.
Tytler, R., Symington, D., & Cripps Clark, J. (2017). Community-School Collaborations in Science: Towards Improved Outcomes Through Better Understanding of Boundary Issues. International Journal of Science and Mathematics Education, 15(4), 643-661
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