In determining how the Appalachian Mountains were formed, various workings of tectonic processes at continental margins are also being illuminated. The research has important implications for understanding specific processes which shaped the earth and for unraveling the record of plate movements now preserved only in present and former continental…

Chemical responses as active and precisely targeted as those of animal immune systems characterize the defenses plants mount against microbial/herbivoral predation and disease. Past and current research in this field is reported and discussed. Applications, such as the prediction of past outbreaks, are also discussed. (JN)

Methods of preparing and characterizing modified electrodes are outlined and several applications are described. Topics include how electrodes are modified, characterization of such electrodes, and why it is necessary to modify electrodes. Reasons include use in electrocatalysis and display devices and in analytical/photoelectrochemical…

Biological nitrogen fixation accounts for almost 70 percent of nitrogen for plant growth. If food is to keep abreast of population growth, even more nitrogen must be fixed. For this international research institutes continue the search for natural variants in the bacterial population while also pursuing novel genetic engineering methods. (Author)

Discusses how, in some circumstances, a two-body reaction (association in absence of a third body) is the only possible association, and how reactions proceed in this case. Taking competition between two/three-body reactions into account, considers relative importance of such combinations and conditions under which the former can be competitive.…

Discusses educational applications and implications of the GeoRef geoscience database. GeoRef is 15 years old and will soon contain one million references. The online product of the database is explained in relation to accessibility, educational impact, and searching methodology. (Author/JN)

Students often have difficulty in understanding the processes responsible for the ionic basis of the membrane potential. Because descriptions in textbooks are not satisfactory and in some cases in error, a discussion of the processes underlying the potential (combining known results) is provided. (Author/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.…

Provides instructions for and examples of balancing chemical equations using a desktop calculator. (JN)

Biographical sketches are given for several women who made early contributions to the science of geology. A short biography of Inge Lehmann is also included as a more recent example of a woman who has made a notable contribution to the geological field. (Author)

Discusses theory of facies models (attempts to synthesize/generalize information about depositional environments), strengths/weaknesses of facies modelling, recent advances in facies models for siliciclastic sediments (focusing on fluvial, lacustrine, eolian and glacial environments, clastic shorelines and continental shelves, and clastic…

Described is the first part of a two-term project involving final-year students in biochemistry. Listed are the required experiments compiled to test students' abilities to search biochemical literature, extract experiments from journals and carry them out, generate data, and interpret results. (CS)

Discusses a series of interactive BASIC computer programs used in general chemistry and quantitative analysis at Emory University (Atlanta, Georgia). Programs include 368 multiple-choice items organized into 23 topics for chemistry; material for quantitative analysis includes both multiple-choice items and numerical problems. (SK)

States that the object of any geochemical survey is to detect the trace element "halo" associated with a mineral deposit. Describes primary and secondary halos and the following types of surveys: stream sediment, water, soil, vegetation, bedrock, and vapor surveys. Briefly reviews future trends including airborne geochemistry. (SK)

Presents a description of the chemical engineering department of the Louisiana State University. (BB)