153,539 research outputs found
Electrofishing survey of the River Calder and its tributaries - April 1978.
An electrofishing survey was undertaken in the period April 24th - 28th as part of the detailed biological study of the Calder Catchment being carried out by this department in early 1978. The sites to be fished were selected to indicate broadly the fishing status of the major sections of the main river and its larger tributaries and by no means
intended to describe the fishing status of the whole catchment in detail. The results on the distributions of fish species are discussed, in general, in relation
to the major polluting influences on the catchment. The results of the second survey are given and discussed separately in Appendix I
Electrofishing, survey of Skirden and Swanside Beck August/September 1987.
As a follow up survey, the report assesses Skirden and Swanside Beck (North West England) in order to determine:
1. The status of these systems as salmonid nursery streams.
2. The success of planting with salmon fry and parr, carried our earlier in the year.
The report gives methods, results, a summary and the author's recommendations
Automated array assembly
Manufacturing techniques are evaluated using expenses based on experience and studying basic cost factors for each step to evaluate expenses from a first-principles point of view. A formal cost accounting procedure is developed which is used throughout the study for cost comparisons. The first test of this procedure is a comparison of its predicted costs for array module manufacturing with costs from a study which is based on experience factors. A manufacturing cost estimate for array modules of $10/W is based on present-day manufacturing techniques, expenses, and materials costs
Precise orbit determination for NASA's earth observing system using GPS (Global Positioning System)
An application of a precision orbit determination technique for NASA's Earth Observing System (EOS) using the Global Positioning System (GPS) is described. This technique allows the geometric information from measurements of GPS carrier phase and P-code pseudo-range to be exploited while minimizing requirements for precision dynamical modeling. The method combines geometric and dynamic information to determine the spacecraft trajectory; the weight on the dynamic information is controlled by adjusting fictitious spacecraft accelerations in three dimensions which are treated as first order exponentially time correlated stochastic processes. By varying the time correlation and uncertainty of the stochastic accelerations, the technique can range from purely geometric to purely dynamic. Performance estimates for this technique as applied to the orbit geometry planned for the EOS platforms indicate that decimeter accuracies for EOS orbit position may be obtainable. The sensitivity of the predicted orbit uncertainties to model errors for station locations, nongravitational platform accelerations, and Earth gravity is also presented
Cooling system for removing metabolic heat from an hermetically sealed spacesuit
An improved cooling and ventilating system is described for removing metabolic heat, waste gases and water vapor generated by a wearer of an hermetically sealed spacesuit. The cooling system was characterized by a body suit, having a first circuit for simultaneously establishing a cooling flow of water through the thorax and head sections of the body suit. Circulation patches were included mounted in the thorax section and head section of the body suit. A second circuit for discharing a flow of gas throughout the spacesuit and a disconnect unit for coupling the circuits with a life support system externally related to the spacesuit were provided
Liquid-cooled liner for helmets
Liner acts as coolant tubing, manifold, and supporting structures. Fabric of waffle-design is made of several integrated channels (or capillaries) through which coolant liquid can flow. Thin and light-weight liner can be incorporated into any type of helmet or head gear
As-built design specification for historical daily data bases for testing advanced models
There are no author-identified significant results in this report
Holographic analysis of thin films
Technique for monitoring deposition of films on surfaces, in place on a real-time basis, reads both the thickness and the uniformity of the deposited film. Holograms are produced from both reflected and transmitted light on one plate
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