Introduces three laboratory exercises which develop an understanding of principles of mechanics by using examples of bicycle operation: Newton's laws, statics and dynamics, and energy relationships. Describes related theory and laboratory procedures with diagrams and pictures in each exercise. (YP)

Summarizes the capabilities of a computer program related to forest fertilization. Provides a description of input parameters, some sample exercises, software specifications, and availability information. Additional references are listed. (Author/RT)

Discusses a student exercise which requires the optimizing of the charring and atomization temperatures by producing a plot of absorbance versus temperature for each temperature parameter. Notes that although the graphite furnace atomic absorption spectroscopy technique has widespread industrial use, there are no published, structured experiments…

Presents an examination of the buoyancy principle which can serve as a simple but rigorous illustration of a falsification test that not only clears up a possible misconception but also points the way to a number of practical uses of buoyancy measurements that have not generally been recognized. (MVL)

Describes the layout, working principle, and uses of an ultrasonic interferometer for demonstrating the impact of the motion of the medium upon wave propagation. Suggests some technical improvements of the interferometer. (YP)

Describes two simple procedures allowing students to experiment with living membranes and to relate their results to fundamental membrane structure. Provides instructions for determining the effects of temperature and organic solvent stress on cellular membranes, and spectrophotometric analysis. (RT)

Discussed is a method of measuring the coefficient of linear expansion of a solid. Getting many data points, using a computer program using the least square fit technique, and modifying the apparatus are described. (YP)

Attempts to show that in the closed loops of cyclic structures the protons situated in conic regions above and below the ring will be shielded. Uses the diamagnetic and air stable octahedral tin(IV) complexes of porphyrins for study. Notes complexes crystallize easily and offer spectacular purple colors. (MVL)

Described are three physics experiments: (1) "Holographic Prism"; (2) "Teaching about Energy with the Gravicar"; and (3) "The Coherer." In each experiment, a brief description of the experiment devised is provided with diagrams and references. (YP)

Discusses the mechanism and the change of pH during the reaction. Notes that a dramatic rise in pH occurs when the reaction nears completion. Evaluates theories by other authors. (MVL)

Gives upper level chemistry students a better understanding of the application of lasers in the field of spectroscopy. Provides three experiments to demonstrate the thermal lens effect: determination of beam profile, cell position optimization, and pKa determination. (MVL)

Describes a combined field and laboratory exercise suitable for teaching concepts of tillering and yield component compensation which is adapted to climatic conditions where extensive class fieldwork is not possible. Provides information on materials and methods, pedagogical aspects, evaluation, and conclusions. (Author/RT)

Demonstrates a variety of electrical phenomena to help explain atomic structure. Topics include: establishing electrical properties, electrochemistry, and electrostatic charges. Recommends demonstration equipment needed and an explanation of each. (MVL)

Describes two demonstrations (1) a dust explosion using a coffee can, candle, rubber tubing, and cornstarch and (2) forming a silicate-polyvinyl alcohol polymer which can be pressed into plastic sheets or molded. Gives specific instructions. (MVL)

Uses paper chromatography with food dyes to provide a simple and inexpensive basis for teaching chromatography. Provides experimental methodology and tabled results. Includes a solvent system comparison (Rf) for seven dyes and twenty-two solvents. (MVL)