Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

PDF

Utah State University

Contamination

Articles 1 - 10 of 10

Full-Text Articles in Physical Sciences and Mathematics

Soil Health And Remediation For Urban Gardens In Utah, Melissa Chilinski May 2023

Soil Health And Remediation For Urban Gardens In Utah, Melissa Chilinski

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Urban environments are at an increased risk of soil contamination and poor soil health due to anthropogenic causes. As healthy farmland is developed, new urban farmers and gardeners are often left growing food on unwanted land with unknown histories of previous use. Varied research and methods for obtaining healthy soils can cause new growers to make decisions that negatively impact soil health and fertility, or on the other hand, conflicting information can cause individuals to become unnecessarily fearful of common soil contaminants and their effect on human health. Common soil contaminants, like trace metals (often referred to as heavy metals) …

Go to article

The Surface Conditions Of Spacecraft Panels May Significantly Affect Spacecraft Survivability, Trace Taylor Feb 2022

The Surface Conditions Of Spacecraft Panels May Significantly Affect Spacecraft Survivability, Trace Taylor

Research on Capitol Hill

USU junior Trace grew up in Brigham City and studies physics and electrical engineering. The majority of spacecraft failure is caused by electron charging on the outer surfaces of the craft. Additionally, contaminants on the craft can cause a film over surface panels, increasing the problem. Trace is studying how roughness on panels can mitigate this contamination as it affects the charging that can lead to craft failure. This research will help determine what optimal panel materials should be used in future spacecraft construction. Trace started research almost as soon as he came to campus in his freshman year, and …

Go to article

Charge Enhanced Contamination And Environmental Degradation Of Misse-6 Suspecs Materials, John R. Dennison, Amberly Evans, Danielle Fulmer, Joshua L. Hodges Feb 2012

Charge Enhanced Contamination And Environmental Degradation Of Misse-6 Suspecs Materials, John R. Dennison, Amberly Evans, Danielle Fulmer, Joshua L. Hodges

All Physics Faculty Publications

The effects of prolonged exposure to the LEO space environment and charge-enhanced contamination on optical, thermal, and electron emission and transport properties of common spacecraft materials have been investigated by comparing pre- and post-flight characterization measurements. The State of Utah Space Environment and Contamination Study (SUSpECS) deployed in March 2008 on board the Materials International Space Station Experiment (MISSE-6) payload, was exposed for ~18 months on the exterior of the International Space Station (ISS), and was retrieved in September 2009. A total of 165 samples were mounted on three separate SUSpECS panels on the ram and wake sides on the …

Go to article

Flight Experiments On The Effects Of Contamination On Electron Emission Of Materials, John R. Dennison, Joshua L. Hodges, Jeff Duce, Amberly Evans Jun 2009

Flight Experiments On The Effects Of Contamination On Electron Emission Of Materials, John R. Dennison, Joshua L. Hodges, Jeff Duce, Amberly Evans

All Physics Faculty Publications

We report on a study of the effects of prolonged exposure to the space environment and of chargeenhanced contamination on the electron emission and resistivity of spacecraft materials. The State of Utah Space Environment & Contamination Study (SUSpECS) was deployed on the International Space Station (ISS) in March 2008 onboard the MISSE-6 payload during STS-123. The Materials International Space Station Experiment (MISSE-6) program is designed to characterize the performance of candidate new space materials over the course of its ~17 month exposure to the LEO environment, with a target return date of August 2009 on STS-127. Approximately 165 samples are …

Go to article

Calculation Of Spectral Degradation Due To Contaminant Films On Infrared And Optical Sensors, L. Gamble, John R. Dennison, B. Wood, J. Herrick, J. S. Dyer Jan 2002

Calculation Of Spectral Degradation Due To Contaminant Films On Infrared And Optical Sensors, L. Gamble, John R. Dennison, B. Wood, J. Herrick, J. S. Dyer

All Physics Faculty Publications

Molecular surface contaminants can cause degradation of optical systems, especially if the contaminants exhibit strong absorption bands in the region of interest. Different strategies for estimation of spectral degradation responses due to uniform films for various types of systems are reviewed. One tool for calculating the effects of contaminant film thickness on signal degradation in the mid IR region is the simulation program CALCRT. The CALCRT database will be reviewed to correlate spectral n and k values associated with specific classes of organic functional groups. Various schemes are also investigated to estimate the spectral degradation in the UV-Vis region. Experimental …

Go to article

Effects Of Evolving Surface Contamination On Spacecraft Charging, W. Y. Chang, John R. Dennison, Jason Kite, R. E. Davies Jan 2000

Effects Of Evolving Surface Contamination On Spacecraft Charging, W. Y. Chang, John R. Dennison, Jason Kite, R. E. Davies

All Physics Faculty Publications

The effects of evolving surface contamination on spacecraft charging have been investigated through (i) ground-based measurements of the change in electron emission properties of a conducting surface undergoing contamination and (ii) modeling of the charging of such surfaces using the NASCAP code. Specifically, we studied a Au surface as adsorbed species were removed and a very thin disordered carbon film was deposited as a result of exposure to an intense, normal incidence electron beam. As a result of this contamination, we found an ~50% decrease in secondary electron yield and an ~20% reduction in backscattered yield. The type and rates …

Go to article

In Situ Bioremediation Of Contaminated Unsaturated Subsurface Soils, Joseph L. Sims, R. C. Sims, R. R. Dupont, J. E. Mathews, M. M. Russell Jul 1994

In Situ Bioremediation Of Contaminated Unsaturated Subsurface Soils, Joseph L. Sims, R. C. Sims, R. R. Dupont, J. E. Mathews, M. M. Russell

Reports

An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of the utilization of these systems, are issues which have been identified by the Regional Superfund Engineering Forum as concerns of Superfund decision makers.

Go to article

Remedial Action Plan For The Codisposal And Stabilization Of The Monument Valley And Mexican Hat Uranium Mill Tailings At Mexican Hat, Utah, Uranium Mill Tailings Remedial Action Project Office, Albuquerque Operations Office, Department Of Energy Feb 1993

Remedial Action Plan For The Codisposal And Stabilization Of The Monument Valley And Mexican Hat Uranium Mill Tailings At Mexican Hat, Utah, Uranium Mill Tailings Remedial Action Project Office, Albuquerque Operations Office, Department Of Energy

All U.S. Government Documents (Utah Regional Depository)

The Mexican Hat tailings site is in the San Juan County, Utah, two road miles southwest of the town of Mexican Hat on the Navajo Reservation. The Navajo community of Halchita is approximately 0.5 mile southwest of the site. The mill at the Mexican Hat site was operated from 1957 to 1965 by Texas-Zinc Minerals Corporation and the Atlas Corporation. Originally, two irregularly shaped tailings piles were located in the northeastern portion of the site. They occupied approximately 69 acres of the 235-acre designated site and contained approximately 2,575,000 cubic yards (cy) of tailings. The total amount of materials, including …

Go to article

Bioremediation Of Contaminated Surface Soils, J. L. Sims, R. C. Sims, J. E. Matthews Aug 1989

Bioremediation Of Contaminated Surface Soils, J. L. Sims, R. C. Sims, J. E. Matthews

Reports

Biological remediation of soils contaminated with organic chemicals is an alternative treatment technology that can often meet the goal of achieving a permanent clean-up remedy at hazardous waste sites, as encouraged by the U.S. Environmental Protection Agency (U.S. EPA) for implementation of The Superfund Amendments and Authorization Act (SARA) of 1986. Bioremediation is consistent with the philosophical thrust of SARA, for it involves the use of naturally occurring microorganisms to degrade and/or detoxify hazardous constituents in the soil at a contaminated slip to protect public health and the environment.Bioremediation of contaminated soils, including applications and limitations, has been addressed.

Go to article

Assessment Of The Radiological Impact Of The Inactive Uranium-Mill Tailings At Mexican Hat, Utah, F. F. Haywood, W. A. Goldsmith, B. S. Ellis, H. M. Hubbard Jr., W. F. Fox, W. H. Shinpaugh, Oak Ridge National Laboratory Mar 1980

Assessment Of The Radiological Impact Of The Inactive Uranium-Mill Tailings At Mexican Hat, Utah, F. F. Haywood, W. A. Goldsmith, B. S. Ellis, H. M. Hubbard Jr., W. F. Fox, W. H. Shinpaugh, Oak Ridge National Laboratory

All U.S. Government Documents (Utah Regional Depository)

High surface soil concentrations of 226Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health effect of exposure to gamma rays during a 2000-hr work year in the area represents an increase of 0.1% in the …

Go to article