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Full-Text Articles in Physical Sciences and Mathematics

Plastic Rain In Protected Areas Of The United States, Janice Brahney, Margaret Hallerud, Eric Heim, Maura Hahnenberger, Suja Sukumaran Jun 2020

Plastic Rain In Protected Areas Of The United States, Janice Brahney, Margaret Hallerud, Eric Heim, Maura Hahnenberger, Suja Sukumaran

Watershed Sciences Faculty Publications

Eleven billion metric tons of plastic are projected to accumulate in the environment by 2025. Because plastics are persistent, they fragment into pieces that are susceptible to wind entrainment. Using high-resolution spatial and temporal data, we tested whether plastics deposited in wet versus dry conditions have distinct atmospheric life histories. Further, we report on the rates and sources of deposition to remote U.S. conservation areas. We show that urban centers and resuspension from soils or water are principal sources for wet-deposited plastics. By contrast, plastics deposited under dry conditions were smaller in size, and the rates of deposition were related …


Strategies For Determining Electron Yield Material Parameters For Spacecraft Charge Modeling, Phil Lundgreen, John R. Dennison Mar 2020

Strategies For Determining Electron Yield Material Parameters For Spacecraft Charge Modeling, Phil Lundgreen, John R. Dennison

All Physics Faculty Publications

Accurate modeling of spacecraft charging is essential to mitigate well‐known and all‐too‐common deleterious and costly effects on spacecraft resulting from charging induced by interactions with the space plasma environment. This paper addresses how limited availability of electron emission and transport properties of spacecraft materials—in particular, secondary electron yields—and the wide ranges measured for such properties pose a critical issue for modeling spacecraft charging. It describes a materials charging database for electron emission properties under development, which facilitates more accurate spacecraft charge modeling when used in concert with the strategies outlined herein. These data and techniques provide tools for more accurate …