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Full-Text Articles in Engineering

Elution Tailing Of Nonaqueous Phase Liquids In Porous Media, Louisa Orr Nov 2017

Elution Tailing Of Nonaqueous Phase Liquids In Porous Media, Louisa Orr

Civil and Environmental Engineering Undergraduate Honors Theses

A variety of porous media were studied to characterize contaminant dispersion over time. This work looked at a compilation of previously published studies to investigate the dependence of long term elution tailing trends on particular soil characteristics. Recession curve analysis was conducted on existing dispersed contaminant literature, to yeild the low-concentration recession constant (K). The R2 values correlating the soil properties to contaminant concentration ranged from 0.12494 to 0.95429. The low-concentration recession constant (K) values ranged from 0.9745407 0.9999988. The relationship between K and the soil properties porosity, organic carbon, and fines fraction is increasing ...


Torrefaction Kinetics Of Hemp Hurds, An Emerging Agricultural Byproduct, In A Small Retort, Tel Jensen Sep 2017

Torrefaction Kinetics Of Hemp Hurds, An Emerging Agricultural Byproduct, In A Small Retort, Tel Jensen

Civil and Environmental Engineering Undergraduate Honors Theses

As knowledge concerning the consequences of unsustainable energy sources and agricultural practices grows, development of low-impact alternatives to both becomes more important. Sustainable sources of biomass offer solutions to both problems. This study characterized the reaction kinetics of torrefying an agricultural byproduct, the woody interior of hemp stems, or hurds. Torrefaction was carried out at 250 °C in small and simple retorts made of galvanized steel pipe. A first-order model most closely approximated the reaction. A sensitivity analysis was performed and the data was adjusted to correct for three potential sources of error, and regressed to find the best fit ...


A Statistical Investigation Of Lower Columbia River Water Temperature, 1915-2003, Corina Christina Mae Overman Aug 2017

A Statistical Investigation Of Lower Columbia River Water Temperature, 1915-2003, Corina Christina Mae Overman

Civil and Environmental Engineering Undergraduate Honors Theses

The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (Tw) to survive. In recent years, high summer Tw in the Columbia River has caused increased mortality of salmon. Different possible explanations for increased Tw include climate change, deforestation, and decreased summertime streamflow (Q) due to dams. In this study, robust linear regression models of Tw based on air temperature (Ta) and Q were developed to examine the change in Tw over time. The data was separated into an historical period (1938-1956 ...


Effectiveness Of Indoor Plants For Passive Removal Of Indoor Ozone, Omed A. Abbass, David J. Sailor, Elliott T. Gall Jul 2017

Effectiveness Of Indoor Plants For Passive Removal Of Indoor Ozone, Omed A. Abbass, David J. Sailor, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor vegetation is often proposed as a passive approach for improving indoor air quality. While studies of outdoor environments indicate that vegetation can be an important sink of outdoor ozone, there is scant data in the literature concerning the dynamics of ozone uptake by indoor plants. This study determined ozone deposition velocities (vd) for five common indoor plants (Peace Lily, Ficus, Calathia, Dieffenbachia, Golden Pothos). The transient vd was calculated, using measured leaf areas for each plant, for exposures mimicking three diurnal cycles where ozone concentrations in chamber tests were elevated for 8 h followed by 16 h ...


Hydrodynamic And Water Quality Modeling Of The Chehalis River Using Ce-Qual-W2, Sarah Van Glubt Feb 2017

Hydrodynamic And Water Quality Modeling Of The Chehalis River Using Ce-Qual-W2, Sarah Van Glubt

Dissertations and Theses

The Chehalis River Basin is located in the southwest region of Washington State, originating in the Olympic Mountains and flowing to Grays Harbor and the Pacific Ocean. The Chehalis River is over 125 miles, exists within five counties, and flows through agricultural, residential, industrial, and forest land areas. Four major rivers discharge to the Chehalis River, as well as many smaller creeks, five wastewater treatment plants, and groundwater flows.

Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia, with severe consequences for property, safety and transportation. As a result, construction of a ...