Discusses the flotation method for the determination of the density of solids. Provides the stepwise experimental procedure with typical data tables and graphs. (YP)

Reports that although excitation at 337nm is less than optimal, detection limits in the range 1-100pg/ml were found. Provides a calibration curve and results for seven organic compounds. (MVL)

Describes a science presentation which promotes various ways to improve laboratory safety. Recommendations for storing chemicals include: minimize the type and amount of stocked materials, purchase certain chemicals in small quantities, and use plastic embedments. Cites several books for reference. (RT)

Describes a course entitled "Biotechnology Laboratory" which introduces a variety of laboratory methods associated with biotechnology. Describes the history, content, and seven experiments of the course. The seven experiments are selected from microbiology and molecular biology, kinetics and fermentation, and downstream…

This article looks at the historical interpretations and counterinterpretations of some experiments selected from science history. The homocentric spheres of Eudoxus, hermetic and scientific concepts of the universe in the middle ages, and the change in the concept of the world are included. (KR)

Describes a physics demonstration in which two-liter plastic bottles can be used to show how force relates to pressure and area. Identical drinking straws are launched out of similar plastic bottles with different-sized openings. This demonstration proves qualitatively that pressure is inversely proportional to the area exposed to an object when a…

Describes the history and uses of the coulometer, a device for measuring quantities of electricity. (Contains 27 references.) (Author/WRM)

Reviews the requirements of the National Titration Competition and describes how a team in a local competition used the technique. Compares microscale titration to conventional titration. Outlines the benefits of employing microscale techniques. (DDR)

Recommends the use of heart models in teaching about the circulatory system. Argues that simulation activities can deepen students' understanding of heart structure, dispel misconceptions of the cardiac cycle, and foster awareness of the importance of maintaining a healthy heart. (DDR)

Describes unexpected experiences with student laboratory activities. Makes recommendations for addressing two types of lab disasters: (1) when lab preparations fail prior to the beginning of lab; and (2) when students produce unexpected results with the proper use of materials. (Contains 11 references.) (WRM)

The advent of genomics, proteomics, and microarray technology has brought much excitement to science, both in teaching and in learning. The public is eager to know about the processes of life. In the present context of the explosive growth of scientific information, a major challenge of modern cell biology is to popularize basic concepts of…

Most, if not all, industrial technology (IT) programs have laboratories or workshops. Often equipped with modern equipment, tools, materials, and measurement and test instruments, these facilities constitute a major investment for IT programs. Improper use or over use of program facilities may result in dirty lab equipment, lost or damaged tools,…

This article describes a novel, hands-on method to qualitatively determine the extent of microbial activity in topsoil using ordinary blank paper. Appropriate and scalable for the high school and college level, these experiments expose students to some of the challenges facing environmental researchers and also contribute to curriculum development…

Forty-eight new secondary science teachers participated in a study that required a listing, discussion, and application of criteria to rank three chemistry laboratory procedures. The three similar lab procedures involved synthesis of a compound from its elements. The top criteria noted by teachers focused on procedural issues (i.e., timeliness,…

Understanding the function of the distinct amygdaloid nuclei in learning comprises a major challenge. In the two studies described herein, we used c-Fos immunolabeling to compare the engagement of various nuclei of the amygdala in appetitive and aversive instrumental training procedures. In the first experiment, rats that had already acquired a…