Atomic fluorescence spectroscopy

Imperial Users onl

Computational analysis and preliminary redesign of the nozzle contour of the Langley hypersonic CF4 tunnel

A computational analysis, modification, and preliminary redesign study was performed on the nozzle contour of the Langley Hypersonic CF4 Tunnel. This study showed that the existing nozzle was contoured incorrectly for the design operating condition, and this error was shown to produce the measured disturbances in the exit flow field. A modified contour was designed for the current nozzle downstream of the maximum turning point that would provide a uniform exit flow. New nozzle contours were also designed for an exit Mach number and Reynolds number combination which matches that attainable in the Langley 20-Inch Mach 6 Tunnel. Two nozzle contours were designed: one having the same exit radius but a larger mass flow rate than that of the existing CF4 Tunnel, and the other having the same mass flow rate but a smaller exit radius than that of the existing CF4 Tunnel

AICPA-NASBA Committee on Professional Recognition and Regulation, Report to Spring Meeting of Council, May3, 1972

https://egrove.olemiss.edu/aicpa_assoc/2090/thumbnail.jp

An investigation of the science content preparation of Iowa State University elementary education majors: relationships among secondary and college course backgrounds, attitude toward teaching science, science teaching efficacy, science misconceptions, and science achievement

The goal of this study was to explore the role that formal science content education plays in the process of educating future elementary teachers of science. The formal science content preparation of elementary education majors was investigated to explore the relationships between secondary school and college science content preparation and science achievement, attitude toward teaching science, science teaching efficacy, selected science misconceptions, and other demographic variables. Some of the instruments utilized included Enoch\u27s and Rigg\u27s Science Teaching Efficacy Belief Instrument Form B, Thompson\u27s and Shrigley\u27s Revised Science Attitude Scale, the ACT Science Reasoning Test, student constructed concept maps, and a demographics questionnaire;Although a number of statistically significant relationships were found to exist among the variables, the significant correlations were mainly in what might be classified as low to moderate ranges of correlation;The results of this research can be drawn upon to make recommendations and set strategies for policy makers to consider when determining how to best prepare elementary education majors to teach science

Urgency of Unity, Remarks at AICPA Council Meeting, May 5, 1969

https://egrove.olemiss.edu/aicpa_assoc/2091/thumbnail.jp

ASSESSING THE EFFECTS OF AN AUTHENTIC PROJECT-BASED INTERVENTION ON SECONDARY STUDENTS’ UNDERSTANDING OF ECOSYSTEMS AND THEIR ATTITUDES TOWARD AND INTERESTS IN STEM

There is a need for secondary schools to provide more authentic, hands-on experiences in science, technology, engineering, and mathematics (STEM), and specifically, project-based investigation (PBI) environments in the classroom that focus on real-world problems relevant to students’ experiences, interest, and lives that manifest the Next Generation Science Standards (NGSS) following practices they prescribe. This study investigated how, to what extent, a contextualized aquaponics PBI (APBI) 10-week model unit affected high school students’ attitudes toward STEM in general, and aquaculture and aquaponics in particular, and interests in future STEM-related disciplines and/or STEM career pathways. This study also measured changes in students’ understanding of standard-based ecological relationships and concepts concerning interactions in ecosystems and specifically the phenomena carrying capacity and bacterial nitrification process. Currently, there is very little research literature on how APBI may engage students in learning science, initiate affective attitudes and interest in their local environments, and potentially pique their interests in STEM, and aquaculture/aquaponics fields as a career choice. Using a quantitative methods, quasi-experimental research design, three different student groups who participated in the authentic, hands-on APBI intervention (i.e., treatment groups) were given a pre- and post-attitude/interest survey (N=55). The 12 survey items were rated by a 5-point Likert-type scale that measured changes in student interest and attitudes toward STEM as discipline and area of interest. In addition, the survey included a profile of the respondents with the demographic items. Further, the treatment groups and control group were given a pre- and post-content-aligned test (N=88) which measured changes in students’ ecological knowledge. The results in this study revealed that the intervention contributed to the treatment group students’ positive attitudes toward STEM in general, and aquaculture and aquaponics in particular, and developing an interest in STEM disciplines and/or STEM career pursuits. Results also demonstrate that the project-based intervention, utilizing a real-life aquaculture/aquaponics context, was an effective method to provide meaningful learning and content understanding of standard-based ecological concepts and relationships. The evidence from this study suggest that authentic instructional experiences can facilitate students’ understanding of standard-based ecological concepts and knowledge of ecosystems as the three treatment group students showed statistically significantly higher mean difference (improvement) sum scores after taking the pre- and post-content-aligned assessment when compared to the control group (Group 1). Overall, the gain in understanding and appreciation for and interest in STEM and aquaculture can be attributed to the project-enhanced unit implemented in this study. The implications of this study suggest APBI models may create authentic science learning environments that promote student learning of scientific concepts while piquing their interest in STEM related disciplines and/or career pathways. The intervention design and findings in this study may provide educators new insights and ideas on how to incorporate and use contextualized, aquaponics project-based instruction as a teaching and learning tool. In addition, APBI can offer engaging curricula that articulates NGSS