Every classroom constructs its own culture through the interactions of all participants, students and instructors. This culture, often covert or invisible, has a direct impact on students’ opportunities to learn. Therefore, it is critical that instructors understand their classrooms’ interaction patterns and their effect on student learning. We suggest that discourse analysis may serve as a tool to enhance instructors’ understanding of their classrooms and to serve as an intervention particularly useful for junior faculty as they are beginning their teaching career. To this end, this paper (1) describes the theoretical foundation of discourse analysis and (2) demonstrates its application, effectiveness, and applicability in STEM classrooms, particularly at the introductory level, the time when students make their first steps in negotiating ‘academic literacies’.
Examining the perceptions of first-year undergraduates and their instructors can provide insight into these students’ experiences and shed light on the emerging issues of student attrition and lack of preparedness for the workforce. Students’ perceptions about introductory courses have been examined in previous work. On the other hand, as the high rate of university student dropouts has frequently been attributed to the poor quality of teaching in first-year undergraduate courses, this study aims to investigate the perceptions of faculty members instructing first-year undergraduates. Our analysis results in several emergent themes, which include (1) instructor’s beliefs about Project-Based Learning as a teaching practice, (2) instructor’s level of abstraction when talking about students, (3) instructor’s affect towards students, (4) value instructors place on one-on-one interactions with students, (5) instructors’ perceptions of their role in development of student motivation and interest toward their courses, (6) instructors’ perceived ability to impact students, (7) overall teaching goals, and (8) instructors’ motivation towards teaching. From analysis of these emergent themes, there appear to be two distinct instructor groups. These groups, which we will refer to as Personal Coaches and Group Ushers, are observed to have different attitudes and expressed behaviors towards teaching and their students. These findings are important as they shed light into one aspect of undergraduates’ experience, that of faculty support in students’ academic development. The implications of these findings have a profound effect on how we educate the next generation of our national workforce and particularly STEM professionals and we suggest further investigations in this direction. Understanding faculty perceptions is a key step to affect STEM educational reform.
Harvesting energy from ambient vibration is a promising method for providing a continuous source of power for wireless sensor nodes. However, traditional energy harvesters are often derived from resonant linear oscillators which are capable of providing sufficient output power only if the dominant frequency of input vibrations closely matches the device resonant frequency. The limited scope of such devices has sparked an interest in the use of nonlinear oscillators as mechanisms for broadband energy harvesting. In this study, we investigate the harvesting performance of an electromagnetic harvester sustaining oscillations through the phenomena of magnetic levitation. The nonlinear behavior of the device is effectively modeled by Duffing’s equation, and direct numerical integration confirms the broadband frequency response of the nonlinear harvester. The nonlinear harvester’s power generation capabilities are directly compared to a linear electromagnetic harvester with similar dynamic parameters. Experimental testing shows that the presence of both high and low amplitude solutions for the nonlinear energy harvester results in a tendency for the oscillator to remain in a low energy state for non-harmonic vibration inputs, unless continuous energy impulses are provided. We conclude by considering future applications and improvements for such nonlinear devices.