The "quantum efficiency" (QE) is an important property of a light detector. This quantity can be determined in the undergraduate physics laboratory. The experimentally determined QE of a silicon photodiode appeared to be in reasonable agreement with expected values. The experiment confirms the quantum properties of light and seems to be a useful…

We present a toy model of quantum electrodynamics (QED) in (1 + 1) dimensions. The QED model is much simpler than QED in (3 + 1) dimensions but exhibits many of the same physical phenomena, and serves as a pedagogical introduction to both QED and quantum field theory in general. We show how the QED model can be derived by quantizing a toy model of…

Evolutionary processes can be studied in nature and in the laboratory, but time and financial constraints result in few opportunities for undergraduate and high school students to explore the agents of genetic change in populations. One alternative to time consuming and expensive teaching laboratories is the use of computer simulations. We…

Peer-facilitated workshops enhanced interactivity in our introductory biology course, which led to increased student engagement and learning. A majority of students preferred attending two lectures and a workshop each week over attending three weekly lectures. In the workshops, students worked in small cooperative groups as they solved challenging…

Both harmonic oscillations and friction are the types of concepts in freshman physics that are readily applicable to the "real world" and as such, most students find these ideas interesting. Damped oscillations are usually presented with resistance proportional to velocity, which has the advantage of a relatively straightforward mathematical…

The introductory course in college physics has been criticized as fragmented and lacking in a theme or "story" to tie together the disparate chapters. As physicists, we see it as highly organized and hierarchical, developing from the great principles of Newton, Maxwell, etc. But to the student, it's just the chapter on lost hikers, the chapter on…

Arnol'd's second stability theorem is approached from an elementary point of view. First, a sufficient criterion for stability is found analytically as either -[mu][subscript 1] less than U[double prime]/U-U[subscript s] less than 0 or 0 less than U[double prime]/U-U[subscript s] in the flow, where U[subscript s] is the velocity at the inflection…

Several valerian-containing products sold in pharmacies were evaluated to verify the presence of Valeriana officinalis by identifying the presence of valerenic acid found only in species of Valeriana. The content of valerenic acid was found to vary considerably in the products analyzed, thus emphasizing the importance of standardizing herbal…

A practical hands-on course encompassing enzyme purification, biochemical characterization, and crystallization that completed the course work of 350 second-year bachelor students enrolled in molecular biology/biochemistry was given at the Universite Louis Pasteur of Strasbourg (France). The experimental part of the practical dealt entirely with…

The guided-inquiry approach is applied to the reactions of sodium borohydride and phenyl magnesium bromide with benzaldehyde, benzophenone, benzoic anhydride, and ethyl benzoate. Each team of four students receives four unknowns. Students identify the unknowns and their reaction products by using the physical state of the unknown, an…

Einstein's famous equation E = mc[superscript 2] is derived by utilizing a thought experiment that can be easily understood by any serious student of chemistry. (Contains 3 figures and 2 notes.)

A high-performance liquid chromatography (HPLC) laboratory experiment based on the separation of four prescription drugs (disopyramide, lidocaine, procainamide, and quinidine) is presented. The experiment is set within the forensic science context of the discovery of a patient's mysterious death where a drug overdose is suspected. Each lab group…

A real-time, labeled-free and nanogram-sensitive mass sensor, electrochemical quartz crystal microbalance (EQCM) is used to monitor a cyclic voltammetric deposition of polyaniline (PANI). The results determined that the efficiency for PANI deposition and the anion-doping ratio is calculated in one single cyclic voltammetric.

Introduce students to grant-writing through their own peer-review process.

The photochemical synthesis and subsequent ligand exchange reactions of Ru(CO)[subscript 4] (eta[superscript2]-alkene) compounds has provided a novel experiment for upper-level inorganic chemistry laboratory courses. The experiment is designed to provide a system in which the changing electronic properties of the alkene ligands could be easily…