An optical dectector consisting of a high-speed PIN diode and a transistor was evaluated for use in student experiments with a pulsed-ruby laser. Pulses with 36-nsec risetimes were clearly resolved. (LC)

Describes the construction of an insulated wooden wall incubator that combines excellent temperature control over the usual operating range with easy electrical access, low cost, and a wide potential size range. Presents a temperature- monitoring circuit, designed to measure the small temperature variations within the incubator, which could…

Five technology teachers describe how they would design the technology laboratory for the future. What it would look like, who would use it, what kind of activities would be done in it, the required equipment and supplies, and the expense of the lab are discussed. (KR)

An attempt is made to find a solution to the occasional problem of a need for storing large numbers of graduated cylinders in many teaching and research laboratories. A design, which involves the creation of a series of parallel channels that are used to suspend inverted graduated cylinders by their bases, is proposed.

A multipurpose apparatus that can be used to measure the viscosity of solution by the Ostwald method and the surface tension of solution by the drop-weight method or by the capillary-rise method is developed. The apparatus is convenient for in-situ preparation of solutions of different concentrations and avoids the error that frothing of the…

The construction of two simple, inexpensive apparatuses that clearly show the electrolysis of water are described. Traditionally the electrolysis of water is conducted in a Hofmann apparatus which is expensive and fragile.

Leon Foucault's dramatic demonstration of the rotation of the Earth using a freely-rotating pendulum in 1850 shocked the world of science. Scientists were stunned that such a simple proof of our planet's rotation had to wait so long to be developed. Foucault's public demonstration, which was repeated at many locations around the world, put an end…

Pendulums which swing in two dimensions simultaneously and are designed to leave a record of their motion are termed "harmonographs". The curves which they draw are known, alternatively, as "Bowditch curves" or "Lissajous curves". A variety of designs of harmonographs have been invented over the years. These may be a "Y-suspended" "simple"…

Many general physics laboratories involve the use of springs to demonstrate Hooke's law, and much ado is made about how this can be used as a model for describing the elastic characteristics of materials at the molecular or atomic level. In recent years, the proliferation of computers, and appropriate sensors, have made it possible to demonstrate…

This paper reports the modification of an existing experimental subject into a project laboratory for first-year physics students studying in the first cycle of university level and at a higher professional level. The subject is aimed at developing important science-related competences and skills through concrete steps under circumstances that are…

The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as…

A study conducted shows that if digital photography is combined with regular thin-layer chromatography (TLC), it could perform highly improved qualitative analysis as well as make accurate quantitative analysis possible for a much lower cost than commercial equipment. The findings suggest that digitally enhanced TLC (DE-TLC) is low-cost and easy…

At Oklahoma City Community College, they have developed gel electrophoresis activities that support active learning of many scientific concepts, including: pH, electrolysis, oxidation reduction, electrical currents, potentials, conductivity, molarity, gel electrophoresis, DNA and protein separation, and DNA fingerprinting. This article presents…