Describes an experiment to be performed in an undergraduate biochemistry laboratory that is based on a gradient centrifugation system employing a simple bench top centrifuge, a freezer, and frozen surcose gradient solution to separate macromolecules and subcellular components. (CW)

Describes a kinetic and mechanistic investigation of ascorbic acid by a substitution-inert complex in acidic medium suitable for the undergraduate level. Discusses obtaining the second order rate constant for the rate determining step at a given temperature and comparison with the value predicted on the basis of the Marcus cross-relation. (CW)

Presents a model for planning the measurement of physical quantities. Provides two examples of optimizing the conditions of indirect measurement for laboratory experiments which involve measurements of acceleration due to gravity and of viscosity by means of Stokes' formula. (ML)

Describes a laboratory experiment that is designed to aid in the understanding of the fundamental process involved in gas chromatographic separations. Introduces the Kovats retention index system for use by chemistry students to establish criteria for the optimal selection of gas chromatographic stationary phases. (TW)

Reviews a study that examined the effects of laboratories on the grade performance of undergraduates in an introductory crop science course. Results indicated that students enrolled in lecture and laboratory concurrently did not receive higher lecture grades than students enrolled solely in lecture, but did have higher laboratory grades. (ML)

This study explores the effectiveness of conceptual change oriented instruction and standard science instruction and contribution of logical thinking ability on seventh grade students' understanding of heat and temperature concepts. Misconceptions related to heat and temperature concepts were determined by related literature on this subject.…

Students set in their ways are usually reluctant, as a general rule, to deal with open-ended investigative scenarios. In order to acquaint the student with the physical method and philosophical thought process of the discipline, the tone of the course must be set early on. The present study was conducted to develop scenarios and microbial model…

A prototype system based on an inverted pendulum is used to study the Quality of Service and discuss requirements of remote-experimentation systems utilized for carrying out control engineering experiments over the Internet. This class of applications involves the transmission over the network of a variety of data types with their own peculiar…

This paper presents the experiment being conducted in the Electric Circuits II course (ELE1103) at PUC-Rio's Electrical Engineering Department since March 1997. This experiment was held in both the fall and the spring semesters of 1997. The basis for the experiment was concurrent teaching methodology, to which the principles of entrepreneurship…

Examines the pros and cons of laboratory instruction. Complaints lodged against laboratory instruction include its high cost, and lack of research supporting the lab. Justifications listed include science education research supporting the lab, psychology, and common sense. (DS)

Describes the relationship of Popper's theory of knowledge to chemistry instruction. Suggests that students be allowed to learn from their mistakes and presents five experiments with an implicit falsification purpose. (JN)

Presents seven selected biology notes which could be used in the school biology courses. Each includes the name of the author and a description of activities suggested. (HM)

Describes a technique for the laboratory culture of Eucyclops agilis using Euglena. Details of the life cycle are given, and suggestions for its use in laboratory practicals, and in investigations with sixth-form (16 to 18 year-olds) and college students in the United Kingdom. (Author/HM)

Describes a laboratory demonstration in chemical equilibrium using ferric chloride and ammonium thiocyanate that would serve as a useful basis for an inquiry investigation. (BT)

Described is a base-friction modeling technique for studying the development of collapse structures in jointed rocks. A moving belt beneath weak material is designed to simulate gravity. A description is given of the model frame construction. (Author/SA)