The precision of major—minor silicate analyses employing a rotating disk-solution technique may be improved upon by restricting the number of sparkings on each end of the counter electrode to no more than two times; and by placing a more rigid control on disk weight than presently supplied by the manufacturer, i.e., prior to sparking, weigh the disks and place them in weight categories with a range of no greater than 30 mg. Boom temperature fluctuations of 5°F or less are enough to decrease precision of the analysis; therefore, in order to maintain maximum precision, a tighter control on room temperature is required. Changes in barometric pressure affect the precision of certain major and minor oxides, therefore, during periods of stable barometric pressure the precision of the analysis is at an optimum. Relative humidity in the range of 40%–60% and minor shifts in the optical alignment of the grating appears to have little effect on the precision of the analyses.
A Sagnac interferometer splits an incident beam of light into two components which travel in opposite directions of the same path. Consequently, each beam travels an equivalent distance. However, by rotating the entire apparatus at a sufficient speed, a noticeable change in the beams’ interference pattern is observed. This pattern results from one beam travelling against rotation and the other travelling with rotation, resulting in an increase or decrease in apparent path length, respectively. This is known as the Sagnac Effect. By using a traditional mirror-and-laser interferometer setup and a large turntable, we demonstrate the Sagnac Effect by showing that a given angular velocity results in a phase shift which matches what is predicted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.