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Full-Text Articles in Mining Engineering
Sulfur Dioxide And Particles In Quiescent Volcanic Plumes From Poás, Arenal, And Colima Volcanos, Costa Rica And Mexico, T. Casadevall, William I. Rose, William H. Fuller, William H. Hunt, Mark A. Hart, Jarvis L. Moyers, David C. Woods, Raymond L. Chuan, James P. Friend
Sulfur Dioxide And Particles In Quiescent Volcanic Plumes From Poás, Arenal, And Colima Volcanos, Costa Rica And Mexico, T. Casadevall, William I. Rose, William H. Fuller, William H. Hunt, Mark A. Hart, Jarvis L. Moyers, David C. Woods, Raymond L. Chuan, James P. Friend
Department of Geological and Mining Engineering and Sciences Publications
Measurements of SO2 emission rates and concentrations and of particle distribution, size, shape, and composition were made in quiescent volcanic plumes emitted into the troposphere from Poás and Arenal volcanos, Costa Rica, and Colima volcano, Mexico. SO2 emission rates were 700±180 metric tons per day (t/d) for Poás, 210±30 t/d for Arenal, and 320±50 t/d for Colima. The concentrations of SO2 calculated from the COSPEC/lidar data were 5–380 ppb. Concentrations of SO2measured directly by flame photometry were 10–250 ppb. Particles collected in the plumes with a quartz crystal microbalance impactor were mostly less than 3 …
Amatitlan, An Actively Resurging Cauldron 10 Km South Of Guatemala City, Richard L. Wunderman, William I. Rose
Amatitlan, An Actively Resurging Cauldron 10 Km South Of Guatemala City, Richard L. Wunderman, William I. Rose
Department of Geological and Mining Engineering and Sciences Publications
A 14×16 km diameter collapse caldera has been recognized 10 km south of Guatemala City, Guatemala. The caldera is north of the presently active volcano Pacaya and west of Agua, a large stratovolcano. The caldera was not previously recognized because its eastern and western margins coincide with faults that outline the Guatemala City graben and because the northern margin of the caldera is buried by pyroclastic rocks. The existence of the northern caldera margin is now established by gravity data and a variety of geological observations including circumferential faults, hot springs, well-log data, and lithological changes in sedimentary rocks. A …
Equivalent Electron Fluence For Space Qualification Of Shallow Junction Heteroface Gaas Solar Cells, John W. Wilson, L. V. Stock
Equivalent Electron Fluence For Space Qualification Of Shallow Junction Heteroface Gaas Solar Cells, John W. Wilson, L. V. Stock
Mining Engineering Faculty Research & Creative Works
It is desirable to perform qualification tests prior to deployment of solar cells in space power applications. Such test procedures are complicated by the complex mixture of differing radiation components in space which are difficult to simulate in ground test facilities. Although it has been shown that an equivalent electron fluence ratio cannot be uniquely defined for monoenergetic proton exposure of GaAs shallow junction cells, an equivalent electron fluence test can be defined for common spectral components of protons found in space. Equivalent electron fluence levels for the geosynchronous environment are presented.
Proton Damage In Gaas Solar Cells, John W. Wilson, G. H. Walker, R. A. Outlaw
Proton Damage In Gaas Solar Cells, John W. Wilson, G. H. Walker, R. A. Outlaw
Mining Engineering Faculty Research & Creative Works
A simplified model for the short-circuit current reduction caused by proton-induced radiation damage is described. The model accounts for the nonuniformity of defect production within heteroface GaAs shallow junction solar cells. The results from the model show agreement with the strong energy dependence observed in proton radiation damage experiments.