Describes the necking of polymer sheets that occurs when they are stretched. Discusses the effect and the mechanisms of necking. Lists four references. (YP)

Explains the procedures used to determine the regulatory properties of yeast pyruvate kinase. Involves a partial purification using PEG precipitation that can be done in one laboratory period with simple equipment. (DDR)

Describes a biology unit designed so that students pose their own questions and perform experiments to answer these questions. Plasmodial slime mold is employed as the focus of the study with background information about the mold provided. (DDR)

A simple procedure to quickly screen different consumer products for the presence of lead, cadmium, and other metals is described. This screening technique avoids expending a lot of preparation time on samples known to contain low levels of hazardous metals where only samples testing positive for the desired elements need to be analyzed…

A successful microscale fusion of semicarbazones, or transformation of carbonyl compounds into semicarbazones is performed through an effective grinding system. The donning of protective attire is advised to avoid the hazardous effects of semicarbazide hydrochloride during the fusion process.

The creative application of low-cost, readily available materials and techniques promotes inclusion and provides accessibility in the classroom and laboratory for students who are blind or have low vision. Difficulties encountered by these students include operation of laboratory equipment, execution of ordinary laboratory procedures, and use of…

Multistep syntheses are often important components of the undergraduate organic laboratory experience and a three-step synthesis of 5-(2-sulfhydrylethyl) salicylaldehyde was described. The experiment is useful as a special project for an advanced undergraduate organic chemistry laboratory course and offers opportunities for students to master a…

A set of highly atom-economic experiments was developed to highlight the differences between acid- and base-catalyzed ester syntheses and to introduce the principles of atom economy. The hydrochloric acid-catalyzed formation of an ester was compared with the 4-dimethylaminopyradine-catalyzed ester synthesis.

A typical card sort is an activity in which students are given a set of cards with a single concept written on each card and asked to organize the cards by grouping related concepts. The nontraditional card sorts described in this article foster critical thinking and add elements of inquiry as students use them to develop flowcharts for complex…

Fifteen years ago, Pascual-Leone and colleagues used transcranial magnetic stimulation (TMS) to investigate speech production in pre-surgical epilepsy patients and in doing so, introduced a novel tool into language research. TMS can be used to non-invasively stimulate a specific cortical region and transiently disrupt information processing. These…

Can you imagine a class where students cover the content with each other rather than simply listening to the professor's lecture? Can you envision students developing their own laboratory investigations and quizzing each other weekly to check for understanding? Well, that's pretty much how the major science organizations across the nation are…

A new method is presented for measuring the rate of the oxidation of glucose in the presence of glucose oxidase. The improved method employs luminescence measurements to directly determine the concentration of oxygen in real time, thus obviating complicated reaction schemes employed in previous methods. Our method has been used to determine…

An upper-division forensic chemistry experiment is described. It involves using glycolic acid and sodium glycolate as analogs of [gamma]-hydroxybutyric acid and its sodium salt. The experiment shows the use of silylation in GC-MS analysis and gives students the opportunity to work with a commonly used silylating reagent,…

This article argues that advances in nanotechnology in general, and lab-on-chip technology in particular, have the potential to benefit the developing world in its quest to control risks to human health and the environment. Based on the "risk society" thesis of Ulrich Beck, it is argued that the developed world must realign its science and…