12,410 research outputs found
Towards characterizing the relationship between students' interest in and their beliefs about physics
We examine the relationships between students' self-reported interest and their responses to a physics beliefs survey. Results from the Colorado Learning Attitudes about Science Survey (CLASS v3), collected in a large calculusbased introductory mechanics course (N=391), were used to characterize students' beliefs about physics and learning physics at the beginning and end of the semester. Additionally students were asked at the end of the semester to rate their interest in physics, how it has changed, and why. We find a correlation between surveyed beliefs and self-rated interest (R=0.65). At the end of the term, students with more expert-like beliefs as measured by the 'Overall' CLASS score also rate themselves as more interested in physics. An analysis of students' reasons for why their interest changed showed that a sizable fraction of students cited reasons tied to beliefs about physics or learning physics as probed by the CLASS survey. The leading reason for increased interest was the connection between physics and the real world
The Design and Validation of the Colorado Learning Attitudes about Science Survey
The Colorado Learning Attitudes about Science Survey (CLASS) is a new instrument designed to measure various facets of student attitudes and beliefs about learning physics. This instrument extends previous work by probing additional facets of student attitudes and beliefs. It has been written to be suitably worded for students in a variety of different courses. This paper introduces the CLASS and its design and validation studies, which include analyzing results from over 2400 students, interviews and factor analyses. Methodology used to determine categories and how to analyze the robustness of categories for probing various facets of student learning are also described. This paper serves as the foundation for the results and conclusions from the analysis of our survey dat
Mapping the dynamic interactions between vortex species in highly anisotropic superconductors
Here we use highly sensitive magnetisation measurements performed using a
Hall probe sensor on single crystals of highly anisotropic high temperature
superconductors to study the dynamic interactions
between the two species of vortices that exist in such superconductors. We
observe a remarkable and clearly delineated high temperature regime that
mirrors the underlying vortex phase diagram. Our results map out the parameter
space over which these dynamic interaction processes can be used to create
vortex ratchets, pumps and other fluxonic devices.Comment: 7 pages, 3 figures, to be published in Supercond. Sci. Techno
A New Instrument For Measuring Student Beliefs About Physics and Learning Physics: The Colorado Learning Attitudes About Science Survey
The Colorado Learning Attitudes about Science Survey (CLASS) is a new instrument designed to measure student beliefs about physics and about learning physics. This instrument extends previous work by probing additional aspects of student beliefs and by using wording suitable for students in a wide variety of physics courses. The CLASS has been validated using interviews, reliability studies, and extensive statistical analyses of responses from over 5000 students. In addition, a new methodology for determining useful and statistically robust categories of student beliefs has been developed. This paper serves as the foundation for an extensive study of how student beliefs impact and are impacted by their educational experiences. For example, this survey measures: that most teaching practices cause substantial drops in student scores; that a student's likelihood of becoming a physics major correlates with their 'Personal Interest' score; and that, for a majority of student populations, women's scores in some categories, including 'Personal Interest' and 'Real World Connections', are significantly different than men's scores
A Study of Educational Simulations Part I - Engagement and Learning
Interactive computer simulations with complex representations and sophisticated graphics are a relatively new addition to the classroom, and research in this area is limited. We have conducted over 200 individual student interviews during which the students described what they were thinking as they interacted with simulations. These interviews were conducted as part of the research and design of simulations for the Physics Education Technology (PhET) project. PhET is an ongoing project that has developed over 60 simulations for use in teaching physics, chemistry, and physical science. These interviews are a rich source of information about how students interact with computer simulations and what makes an educationally effective simulation. We have observed that simulations can be highly engaging and educationally effective, but only if the student's interaction with the simulation is directed by the student's own questioning. Here we describe our design process, what features are effective for engaging students in educationally productive interactions and the underlying principles which support our empirically developed guidelines. In a companion paper we describe in detail the design features used to create an intuitive simulation for students to use
On the robustness of ultra-high voltage 4H-SiC IGBTs with an optimized retrograde p-well
The robustness of ultra-high voltage (>10kV) SiC IGBTs comprising of an optimized retrograde p-well is investigated. Under extensive TCAD simulations, we show that in addition to offering a robust control on threshold voltage and eliminating punch-through, the retrograde is highly effective in terms of reducing the stress on the gate oxide of ultra-high voltage SiC IGBTs. We show that a 10 kV SiC IGBT comprising of the retrograde p-well exhibits a much-reduced peak electric field in the gate oxide when compared with the counterpart comprising of a conventional p-well. Using an optimized retrograde p-well with depth as shallow as 1 μm, the peak electric field in the gate oxide of a 10kV rated SiC IGBT can be reduced to below 2 MV.cm -1 , a prerequisite to achieve a high-degree of reliability in high-voltage power devices. We therefore propose that the retrograde p-well is highly promising for the development of>10kV SiC IGBTs
Developing and Researching PhET simulations for Teaching Quantum Mechanics
Quantum mechanics is difficult to learn because it is counterintuitive, hard
to visualize, mathematically challenging, and abstract. The Physics Education
Technology (PhET) Project, known for its interactive computer simulations for
teaching and learning physics, now includes 18 simulations on quantum mechanics
designed to improve learning of this difficult subject. Our simulations include
several key features to help students build mental models and intuitions about
quantum mechanics: visual representations of abstract concepts and microscopic
processes that cannot be directly observed, interactive environments that
directly couple students' actions to animations, connections to everyday life,
and efficient calculations so students can focus on the concepts rather than
the math. Like all PhET simulations, these are developed using the results of
education research and feedback from educators, and are tested in student
interviews and classroom studies. This article provides an overview of the PhET
quantum simulations and their development. We also describe research
demonstrating their effectiveness and share some insights about student
thinking that we have gained from our research on quantum simulations.Comment: accepted by American Journal of Physics; v2 includes an additional
study, more explanation of research behind claims, clearer wording, and more
reference
A device-dependent interface for interactive image display
The structure of the device independent Display Management Subsystem (DMS) and the interface routines that are available to the applications programmer for use in developing a set of portable image display utility programs are described
Viable 3C-SiC-on-Si MOSFET design disrupting current Material Technology Limitations
The cubic polytype (3C-) of Silicon Carbide (SiC) is an emerging semiconductor technology for power devices. The featured isotropic material properties along with the Wide Band Gap (WBG) characteristics make it an excellent choice for power Metal Oxide Semiconductor Field Effect Transistors (MOSFETs). Nonetheless, material related limitations originate from the advantageous fact that 3C-SiC can be grown on Silicon (Si) wafers. One of these major limitations is an almost negligible activation of the p-type dopants after ion implantation because the annealing has to take place at relatively low temperatures. In this paper, a novel process flow for a vertical 3C-SiC-on-Si MOSFET is presented to overcome the difficulties that currently exist in obtaining a p-body region through implantation. The proposed design has been accurately simulated with Technology Computer Aided Design (TCAD) process and device software and a comparison is performed with the conventional SiC MOSFET design. The simulated output characteristics demonstrated a reduced on-resistance and at the same time it is shown that the blocking capability can be maintained to the same level. The promising performance of the novel design discussed in this paper is potentially the solution needed and a huge step towards the realisation of 3C-SiC-on-Si MOSFETs with commercially grated characteristics
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