Experimental design of packaging materials to withstand the impact of gravity by 5th grade students. (EJS)

A 1-hour laboratory exercise which demonstrates the correctness of the relativistic relationship between energy and momentum is described. In addition, a value of Planck's constant and the velocity of light can be derived. (JN)

Einstein's equivalence principle relates effects seen by an accelerating observer to those experienced by an observer in a gravitational field, providing an explanation of bending of a light beam by gravity. Because the calculations lead to results one-half the value found experimentally, obtaining the correct light deflection is discussed.…

Describes an experiment to demonstrate Boyle's law that provides pressure measurements in a familiar unit (psi) and makes no assumptions concerning atmospheric pressure. Items needed include bathroom scales and a 60-ml syringe, castor oil, disposable 3-ml syringe and needle, modeling clay, pliers, and a wooden block. Commercial devices use a…

Describes a very simple and effective method of DNA extraction from dried peas. Presents information on the Green Machine Science Education Center that promotes education in gene technology. (JRH)

Describes an experiment using a plant pathogenic fungus in which students learn to follow aseptic techniques, grow and produce spores of a fungus, use a hemacytometer for enumerating spores, prepare serial dilutions, grow and inoculate plants, isolate a pure culture using agar streak plates, and demonstrate the four steps of Koch's postulates.…

Traces the evolution of physics research methods in Finland from passive observations to planned experiments. Presents examples of planned experiments designed to solve particular problems with the goal of establishing a theory of the phenomenon under study. Contains 16 references. (JRH)

Presents an experiment designed to give students some experience with photochemistry, electrochemistry, and basic theories about semiconductors. Uses a liquid-junction solar cell and illustrates some fundamental physical and chemical principles related to light and electricity interconversion as well as the properties of semiconductors. (JRH)

Presents a headspace gas chromatography experiment that enables discovery of the temperature dependence of the vapor pressure of a pure liquid. Illustrates liquid-vapor phase equilibrium of pure liquids. Contains 22 references. (JRH)

Presents an experiment designed to show students that the Henderson-Hasselbalch equation will fail when they use this particular one-half titration technique for acids with large pKa's. Involves determining the apparent pKa for such acids and using that to calculate the true pKa. (JRH)

Presents methods commonly used for investigating enzyme activity using catalase and presents a new method for measuring catalase activity that is more reliable and accurate. Provides results that are readily reproduced and quantified. Can also be used for investigations of enzyme properties such as the effects of temperature, pH, inhibitors,…

Presents a protocol that uses reverse phase chromatography for the separation of chloroplast pigments. Provides a simple and relatively safe procedure for use in teaching laboratories. Discusses pigment extraction, chromatography, results, and advantages of the process. (JRH)

Presents an exercise that demonstrates how plants cope with multiple resource limitations in the field. Stimulates students to think about interactions among multiple limited resources and the challenges plants as immobile organisms face when characteristics that increase the capture of one resource negatively impact the availability of another.…

Discusses clinical trials in general, protecting human research subjects, and the role the research administrator can play in facilitating the process. The discussion is not intended to be a thorough treatise on clinical trials, but is an overview of new and lesser known human protection issues that are better handled prospectively. (EV)