We introduce a model of radiative transfer in circumstellar dust shells. By assuming that the shell is both isothermal and its thickness is small compared to its radius, the model is simple enough for students to grasp and yet still provides a quantitative description of the relevant physical features. The isothermal model can be used in a…

In basic physics courses at undergraduate level, the dynamics of self-propelled bodies is presented as an example of momentum conservation law applied to systems with time-varying mass. However, is often studied the simple situation of free motion or the motion under the action of a constant gravitational field. In this work, we investigate the…

In the framework of group theory, a new procedure is described for a one-step automated reduction of reducible representations. The matrix inversion tool, provided by standard spreadsheet software, is applied to the central part of the character table that contains the characters of the irreducible representation. This method is not restricted to…

An inexpensive multichannel pipet designed to deliver small volumes of liquid simultaneously to wells in a multiwell plate can be prepared by students in a single laboratory period. The multichannel pipet is made of disposable plastic 1 mL syringes and drilled plastic plates, which are used to make plunger and barrel assemblies. Application of the…

The physical significance of complex characters is explored with particular reference to the C[subscript 4] point group. While a diagrammatic representation of these characters in this group is possible, the extension to higher groups C[subscript n], n greater than 4 is left as a problem for discussion. (Contains 3 tables, 8 figures, and 1 note.)

In this article a thin optical lens model is considered. It is shown that the limits of its applicability are determined not only by the ratio between the thickness of the lens and the modules of the radii of curvature, but above all its geometric type. We have derived the analytical criteria for the applicability of the model for different types…

The purpose of this study was to explore how to enhance students' critical thinking in an introductory undergraduate science course. As a design experiment, this study aimed to design, develop, implement, and refine learning activities, and investigate how the learning activities worked in fostering students' critical thinking in a large size…

High school honor graduates at a rural high school in the Southeastern United States of America have not been as prepared for science classes at the college level as their teachers expected. At the study site, which is located in one rural high school, honor graduates have been struggling with their freshman college science classes although these…

Optical activity using an iPad as a source of polarized light is demonstrated. A sample crystal or solution can be placed on the iPad running a white screen app. The sample is viewed through a polarized filter that can be rotated. This setup can be used in the laboratory or with a document camera to easily project in a large lecture hall.…

This article describes the development of a ten-item scale to assess biology majors' self-efficacy towards the critical thinking and data analysis skills taught in an upper-division cell biology course. The original seven-item scale was expanded to include three additional items based on the results of item analysis. Evidence of reliability and…

This study focuses on processes and outcomes associated with a faculty grassroots initiative to reform teaching and learning in an introductory chemistry course at a research university. The purpose of this study is threefold. First, the study considers faculty groups and teams as sites and sources of pedagogical change in an effort to improve…

Women are underrepresented in most scientific disciplines, with achievement gaps expanding throughout the career trajectory. Gender differences in perceptions of scientific competence are evident at an early age. We examined the extent to which college-level instructor gender affects the confidence of males and females in their scientific…

Academic success in first-year college science coursework can strongly influence future career paths and usually includes a solid performance in introductory biology. We wanted to know whether factors affecting biology student performance might include learning style preferences and one's ability and confidence in self-assessing those learning…

Two separate writing-to-learn activities in which students wrote to authentic audiences outside of the instructor were used in a college integrated science course, Science of Water. For the first task, students were asked to write to fourth-grade students, and for the second, students were asked to write to their academic advisor. An overview of…

The purpose of this study is to investigate whether the teaching, learning and assessment strategies conceived and implemented in a higher education chemistry course promote the development of higher-order skills as intended. Thus, our main aim is to analyse the approaches to learning in chemistry undergraduates. This research was carried out in a…