A thermal oscillator is a self-sustained, nonlinear oscillating system. One part of the system vibrates continuously because of the transfer of heat. Four such devices, two new and two demonstrated in the 19th century are described. Although each depends on the periodic redistribution of heat, they are all quite different. (Author/JN)

Describes a low-cost, high-voltage, two-terminal, constant-current source for student use in electrophoresis experiments (includes circuit diagram) and a simple device for the continuous registering of gas flows. Also lists seven cost-saving tips for chemical reagent, including use decorative stones (purchased from nursery stores) in place of…

Discusses analytical design and experimental verification of a PID control value for a temperature controlled liquid delivery system, demonstrating that the analytical design techniques can be experimentally verified by using digital controls as a tool. Digital control instrumentation and implementation are also demonstrated and documented for…

Tandem electrostatic accelerators produce beams of positive ions which are used to penetrate atomic nuclei in a target, inducing nuclear reactions whose study elucidates varied properties of the nucleus. Uses of the system, which acts like a mass spectrometer, are discussed. These include radiocarbon dating measurements. (JN)

Discusses the basics of scientific glassblowing, including equipment needed, lighting a hand torch (which uses a gas and oxygen mixture), and cutting tubing. Also discusses preparation of butt joints, tee joints, and bends. Photographs illustrating various techniques are provided. (JN)

In addition to oceans, the earth is subjected to tidal stresses and undergoes tidal deformations. Discusses origin of tides, tidal stresses, and methods of determining tidal deformations (including gravity, tilt, and strain meters). (JN)

Describes contruction of an instrument which measures effects of reversible physiological changes on the motor coordination of laboratory animals. The "rotarod" is used to perform carefully planned, humane experiments which produce quantifiable results. A photograph and diagram of the apparatus are provided. (JN)

A chromatographic procedure for analyzing organophosphorus pesticides (such as PCB's, nitrosamines, and phthalate esters) in orange juice is described, including a summary of the method, instrumentation, methodology, results/discussion, and calculations. (JN)

Describes a science education class developed for elementary school children who are blind, deaf, or emotionally disturbed. Lessons are designed to work equally well for physically handicapped, emotionally disturbed, and nonhandicapped children. Concepts include modified classroom equipment, development of independence, and the role of the teacher…

Due to the expense of glass eye-piece grids and haemocytometers, suggests using a simple film grid (made from photographic film) in the same way as an eye-piece graticule is used. A diagram of the grid is provided as well as examples of its use. (JN)

Describes a low-cost instrument using a solar cell as a sensor to measure both instantaneous and integrated value of solar flux. Constructing and calibrating such an instrument constitutes an undergraduate experimental project, affording students an opportunity to examine a variety of aspects associated with solar energy measurements. (Author/SK)

Describes collection of quantitative samples of microorganisms and accumulation of physical data from a pond over a year. Provides examples of how final-year degree students have used materials and data for ecological projects (involving mainly algae), including their results/conclusions. Also describes apparatus and reagents used in the student…

Presents specific techniques for lectures and demonstrations in acoustics for deaf students. (SK)

Provides methods for making instruments and supplies accessible to the visually impaired student in the chemistry laboratory and classroom. (CS)

Presents a technique to produce samples for x-ray diffraction studies on the Tel-X-Ometer 80 x-ray apparatus from readily available crystalline powders and discusses observations of transverse modes of an optical resonator. (SK)