Various studies indicate that high school physics students and even college students majoring in physics have difficulties in qualitative understanding of basic concepts and principles of physics. For example, studies carried out with the Force Concept Inventory (FCI) illustrate that qualitative tasks are not easy to solve even at the college…

Idealized models are often used in introductory physics courses. For one, such models involve simple mathematics, which is a definite plus since complex mathematical manipulations quickly become an obstacle rather than a tool for a beginner. Idealized models facilitate a student's understanding and grasp of a given physical phenomenon, yet they…

The purpose of this activity is for students to build a rainstick out of materials in their own environment and imitate the sound of rain while investigating the physical principles of sound. Students will be able to relate the sound produced by an instrument to the type and quantity of materials used in its construction.

Students frequently confuse and incorrectly apply the several "deltas" that are used in chemical engineering. The deltas come in three different flavors: "out minus in", "big minus little" and "now versus then." The first applies to a change in a stream property as the stream flows through a process. For example, the "[delta]H" in an energy…

Examples of conceptests and suggestions for preparing them for use in an undergraduate, chemical engineering thermodynamics course are presented. Conceptests, combined with hand-held transmitters (clickers), is an effective method to engage students in class. This method motivates students, improves their functional understanding of…

The Onsager reciprocal relations are essential to multicomponent transport theory. A discussion of the principles that should be used to derive flux laws for coupled diffusion is presented here. Fluctuation theory is employed to determine the reciprocal relation for transport coefficients that characterize coupled mass and heat transfer in binary…

Ask a graduating chemical engineering student the following question: What makes one reactor different from the next? The answers received will often be unsatisfactory and will vary widely in scope. Some may cite the difference between the basic design equations, others may point out a PFR is "longer," and still others may state that it…

This paper proposes a different experimental setup compared with the traditional ones, in order to determine the acceleration of gravity, which is carried out by using a fluid at a constant rotation. A computerized rotational system--by using a data acquisition system with specific software, a power amplifier and a rotary motion sensor--is…

The Understanding Evolution website (http://evolution.berkeley.edu/) was developed to provide a freely accessible resource that promotes the teaching of evolution and improved understandings of evolution among students and the general public. Evaluations show that the strategies employed in site design have allowed it to effectively meet those…

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS or simply MALDI) has become ubiquitous in the identification and analysis of biomacromolecules. As a technique that allows for the molecular weight determination of otherwise nonvolatile molecules, MALDI has had a profound impact in the molecular…

The process of diffusion is described as the movement of a substance from an area of high concentration to an area of low concentration. In this article, the authors present a novel way to introduce students to diffusion through the use of an analytical puzzle. This exercise engages students in active learning through a thought provoking exercise…

Many high school biology courses address mainly the molecular and cellular basis of life. The complexity that underlies the most essential processes is often difficult for the students to understand; possibly, in part, because of the inability to see and explore them. Six simple practical experiments on purine catabolism as a part of a…

This paper describes ongoing research investigating student approaches to quantitative and qualitative problem solving in physics. This empirical study was conducted using a phenomenographic approach to analyze data from individual semistructured problem solving interviews with 22 introductory college physics students. The main result of the study…

This article describes the use of limits in topics that are usually covered in a high school advanced placement chemistry course or a first-year college chemistry course. Such an approach supplements the interpretation of the graph of an equation since it is usually easier to evaluate the limit of a function than to generate its graph. In…

In the last 25 years, A-level Mathematics syllabi have changed very considerably, introducing a broader range of application areas but reducing the previous emphasis on classical mechanics. This article describes a baseline survey undertaken to establish in detail the entry levels in mechanics for the cohort of students entering Engineering…