We report on a study of the forced van der Pol equation x + [epsilon](x[superscript 2] - 1)x + x = F cos[omega]t, by solving numerically the differential equation for a variety of values of the parameters [epsilon], F and [omega]. In doing so, many striking and interesting trajectories can be discovered and phenomena such as frequency entrainment,…

The use of electronic instrumentation to monitor physiological function in conscious research animals and humans has become routine. Beyond basic research, animal studies using these methods are required by government regulatory agencies worldwide before human testing of potential new drugs. Living, as we do, in an age of miniaturized high-tech…

Our school has a very small budget for equipment. So finding a gem like a conservation of momentum lab requiring only basic materials ("TPT", October 2005) adds a great deal to my physics course. In this lab, a "shooter" nickel makes a non-head-on collision with a stationary "target" nickel. Students measure the distance each nickel slides after…

We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…

The aryl sulfonate ester, menthyl N-acetylsulfanilate, is synthesized from N-acetylsulfanilyl chloride and menthol in pyridine, then pyrolyzed (thermally decomposed) at reduced pressure. The volatile (elimination) products of the reaction are analyzed using gas chromatography, and the resulting product distribution is used to determine whether the…

Headspace (HS) gas chromatography (GC) is commonly used to analyze samples that contain non-volatiles. In 1996, a new sampling technique called single drop microextraction, SDME, was introduced, and in 2001 it was applied to HS analysis. It is a simple technique that uses equipment normally found in the undergraduate laboratory, making it ideal…

To promote understanding of the authority of the primary literature in students taking our biochemistry laboratory courses, a biochemistry laboratory exercise on the determination of an acceptable molar absorptivity value of 2-nitrophenol (2-NP) was developed. This made the laboratory course much more relevant by linking to a thematic thread,…

A simple experimental set-up to study free and forced convection in undergraduate physics laboratories is presented. The flat plate of a domestic iron has been chosen as the hot surface, and a hairdryer is used to generate an air stream around the plate. Several experiments are proposed and typical numerical results are reported. An analysis and…

A sorption experiment using a gas chromatograph is described that can help students understand the "molecular-shape selectivity" behavior of zeolites in the subnano regime. Hexane isomers are used as probe molecules to demonstrate the sorption phenomena. In the experiment, a zeolite adsorbs certain hexane isomers with molecular sizes smaller than…

This program evaluation study addressed the struggle of local elementary school speech-language pathologists (SLPs) in a school district to provide evidence-based intervention in language for students below grade level as required by the U.S. Department of Education. Recently, Language Lab™ was published to address the needs of oral language…

Microcomputer based laboratory activities have been suggested to have a number of benefits in science education. However, their implementation produces mixed results, and student perception data have in the past yielded responses that are negative regarding the technology. This work presents a case study of three first year undergraduate chemistry…

The level of job performance, international comparability and competitiveness of Nigerian university graduates are burning issues. Consequently, the academic quality of Nigerian universities has come under severe criticism. Since university lecturers are key players in quality control in universities, this study explored their perceptions of…

We use the theory of communities of practice and the concept of accountable disciplinary knowledge to describe how a learning community develops in the context of an upper-division physics laboratory course. The change in accountable disciplinary knowledge motivates students' enculturation into a community of practice. The enculturation process is…

The purpose of this qualitative multiple-case study was to explore academic leaders' experiences with the organizational elements of their own high school-college writing center collaborations. Conjoining theories framed this study: collaborative leadership theory, Kenneth Bruffee's notion of social constructionism and collaborative learning…

This dissertation is a combination of two research areas, experimental physical chemistry, Chapters I to V, and chemical education, Chapters VI to VII. Chapters I to V describe research on the water-mediated chemistry of oxidized atmospheric molecules and the impact that water has on the spectra of these environmental systems. The role of water…