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Geology topics

L.A. Dedini

Publications and source records attributed to L.A. Dedini.

3 recordsLinked to original sources

The design of a microprocessor-based data logger

The design of a microprocessor-based data logger, which collects and digitizes analog voltage signals from a continuous-measuring instrumentation system and transmits serial data to a magnetic tape recorder, is discussed. The data logger was assembled from commercially-available components and can be user-programmed for greater flexibility. A description of the data logger hardware and software designs, general operating instructions, the microprocessor program listing, and electrical schematic diagrams are presented.

Open-File Report↗

Continuous water sampling and water analysis in estuaries

Salinity, temperature, light transmission, oxygen saturation, pH, pCO2, chlorophyll a fluorescence, and the concentrations of nitrate, nitrite, dissolved silica, orthophosphate, and ammonia are continuously measured with a system designed primarily for estuarine studies. Near-surface water (2-m depth) is sampled continuously while the vessel is underway; on station, water to depths of 100 m is sampled with a submersible pump. The system is comprised of commercially available instruments, equipment, and components, and of specialized items designed and fabricated by the authors. Data are read from digital displays, analog strip-chart recorders, and a teletype printout, and can be logged in disc storage for subsequent plotting. Data records made in San Francisco Bay illustrate physical, biological, and chemical estuarine processes, such as mixing and phytoplankton net production. The system resolves large- and small-scale events, which contributes to its reliability and usefulness.

Open-File Report↗

Salinity and temperature measurements in San Francisco Bay waters, 1980

Measurements of salinity and temperature in waters of the San Francisco Bay estuarine system are presented. Sampling was conducted at selected locations (stations) and depths over the period between January-December 1980 at approximately two week intervals. Stations were located in deep channels and adjacent shallow water areas from Calaveras Point in South San Francisco Bay to the town of Rio Vista on the Sacramento River and to the Three-Mile Slough on the San Joaquin River. Numerical values of salinity, temperature, and station locations are tabulated. Contour maps of deep-channel salinity and temperature are presented and the analytical methods are briefly described.

Open-File Report↗