The capillary rise/fall of a liquid within a thin capillary tube is described by the well-established Jurin's law. The liquid reaches an equilibrium height/depth as the capillary pressure is balanced by the hydrostatic pressure. When the adhesion force at the three-phase contact line is counteracted by the liquid weight, the liquid column also…

Enzyme stereospecificity and equilibrium thermodynamics can be demonstrated using the coupling of two amino acid derivatives by Thermoase C160. This protease will catalyze peptide bond formation between Z-L-AspOH and L-PheOMe to form the Aspartame precursor Z-L-Asp-L-PheOMe. Reaction completion manifests itself by precipitation of the product. As…

This article describes a simple and robust laboratory exercise on the regulation of membrane unsaturated fatty acid composition in bacteria by a decrease in growth temperature. We take advantage of the well characterized Des pathway of "Bacillus subtilis", composed of a [delta]5-desaturase (encoded by the "des" gene) and the canonical…

The production of bioethanol from cellulosic waste is described. The experiment is suitable for students in secondary school classroom settings and leads to bioethanol in a concentration high enough to burn the liquid. The experiment consists of three steps: (i) the cellulose of the waste material is converted to glucose by cellulase enzymes, (ii)…

In the 1960s, Tanzanian student Erasto Mpemba and his teacher published a paper with the title "Cool?" in this journal (Mpemba and Osborne 1969 "Phys. Educ." 4 172-5). They claimed that hot water freezes more quickly than cold water. The paper not only led to a wave of discussion, and more publications about this topic, but also to a whole series…

An upper-division laboratory project has been developed as a collaborative investigation of a reaction routinely taught in organic chemistry courses: the reduction of carbonyl compounds by borohydride reagents. Determination of several trends regarding structure-activity relationship was possible because each student contributed his or her results…

In this paper we suggest a simple technique for validating the Goldstein-Wehner law for a stratified positive column of dc glow discharge while studying the properties of gas discharges in an undergraduate laboratory. To accomplish this a simple device with a pre-vacuum mechanical pump, dc source and gas pressure gauge is required. Experiments may…

Much of the nature of science research has been focused on high school students. High school students are primarily the target of such research to aid and to guide them in making informed decisions about possible career choices in the sciences (Bell, Blair, Crawford, & Lederman, 2002). Moreover, during review of the literature, little to no…

Fermat's principle is considered as a unifying concept. It is usually presented erroneously as a "least time principle". In this paper we present some software that shows cases of maxima and minima and the application of Fermat's principle to the problem of focusing in lenses. (Contains 12 figures.)

Liquid-free cryogenic devices are acquiring importance in basic science and engineering. But they can also lead to improvements in teaching low temperature and solid-state physics to graduate students and specialists. Most of the devices are relatively expensive, but small-sized equipment is slowly becoming available. Here, we have designed…

A survey and analysis of four major research paradigms--positivism, postpositivism, critical theory and constructivism--reveal that all have been applied effectively in recent theological inquiry. Although these paradigms might resemble worldviews to some extent, they are not so all-encompassing. Rather, they are essentially matrices of deeply…

Thermodynamic principles are basic to an understanding of the complex fluxes of energy and information required to keep cells alive. These microscopic machines are nonequilibrium systems at the micron scale that are maintained in pseudo-steady-state conditions by very sophisticated processes. Therefore, several nonstandard concepts need to be…

The new Minnesota Case Study Collection is profiled, along with other examples. They complement the work of the HIPST Project in illustrating the aims of: (1) historically informed inquiry learning that fosters explicit NOS reflection, and (2) engagement with faithfully rendered samples of Whole Science.

Studies regarding the whoosh bottle combustion experiment have largely focused on the detonation hazard of the demonstration, particularly with regards to fuel and container choice. Previous work has suggested that the fuel should be 2-propanol owing to its relatively cool flame characteristics. The current study has found that the combustion of…

Revision can be a rather dull part of the academic year, especially if it means the wholesale revisiting of the syllabus using the same old notes. This article presents an attempt at using the "biography" of an element to give an alternative framework for recapping some of the key concepts in a typical A-level chemistry syllabus. It does…