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Portland State University

Theses/Dissertations

Civil and Environmental Engineering Undergraduate Honors Theses

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Precipitation Impacts On Groundwater Levels In The Ephemeral Holgate Lake: A Modflow Inquiry, Amory Cervarich Jun 2018

Precipitation Impacts On Groundwater Levels In The Ephemeral Holgate Lake: A Modflow Inquiry, Amory Cervarich

Civil and Environmental Engineering Undergraduate Honors Theses

Holgate Lake, an ephemeral lake located in southeast Portland, has a history of flooding and inundating residential areas. The appearance of the lake is hypothesized to be a function of precipitation-driven changes in groundwater levels. A model was developed using MODFLOW-NWT, a U.S. Geological Survey (USGS) modular hydrologic program, to analyze parameters contributing to the appearance of the lake. The model was most sensitive to changes in aquifer properties including hydraulic conductivity and storativity. The model displayed low sensitivity to changes in precipitation, evapotranspiration, and conductance of surface waters. Results from the analysis contribute to a better understanding of ...


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 ...


Rate-Limited Mass Transfer Of Trichloroethene, Deza R. Irving Jan 2017

Rate-Limited Mass Transfer Of Trichloroethene, Deza R. Irving

Civil and Environmental Engineering Undergraduate Honors Theses

Trichloroethene (TCE) is a volatile and toxic contaminant commonly found in the subsurface. To help reduce the effects of this contaminant, it is important to understand the transport and fate behavior of TCE through the subsurface. As groundwater fills the void spaces of a porous media contaminated with pure-phase TCE, the TCE will dissolve into the water, contaminating the groundwater. It was expected that this dissolution would follow a first-order mass transfer process, suggesting that the rate of dissolution of TCE is dependent on the mass of TCE present in solution. The purpose of this study was to characterize the ...


Emerging Pollutants In The Columbia River: A Simple Assessment Of Nonpoint Source Zones, Chulgi Kim Jan 2017

Emerging Pollutants In The Columbia River: A Simple Assessment Of Nonpoint Source Zones, Chulgi Kim

Civil and Environmental Engineering Undergraduate Honors Theses

Water quality modeling in the Columbia River Basin was conducted at the confluence of the Willamette and Columbia Rivers, river mile 101. The study area for this research consists of Sauvie Island, OR, and the surrounding areas of Vancouver, WA. Analysis of the region’s watershed and simple hydrologic calculations allowed for estimates of potential sources contributing to PBDEs in the Columbia River along river mile 101. This research included assessment of rainfall patterns and peak discharge rates in the areas along the rivers. A simple model of overland flow for the watershed was applied to estimate the area’s ...


Preliminary Design Guidelines For Poraver-Based Lightweight Concrete, Marlow Stanton Jan 2016

Preliminary Design Guidelines For Poraver-Based Lightweight Concrete, Marlow Stanton

Civil and Environmental Engineering Undergraduate Honors Theses

This research project investigated lightweight Portland cement concrete batching procedures and developed guidelines for designing Poraver-based mixes. Lightweight concrete has a variety of applications, from structural fills to structural members. The study was completed in two stages: Stage 1 was a pilot study serving to confirm whether the ACI211.2-98 Volumetric Method was appropriate for Poraver-based lightweight concrete. Additionally, Stage 1 examined the range of outcomes possible with a large combination of test mixes and explored handling techniques for presoaked aggregate. Stage 2 focused on confirming the linear relationship of cement content and compressive strength through a large quantity of ...


Small-Scale Minimal-Maintenance Anaerobic Digestion Of Food Waste For Solids Reduction And Methane Production: Feasibility Study, Leland C. Scantlebury Jan 2014

Small-Scale Minimal-Maintenance Anaerobic Digestion Of Food Waste For Solids Reduction And Methane Production: Feasibility Study, Leland C. Scantlebury

Civil and Environmental Engineering Undergraduate Honors Theses

Six gallons of food waste was anaerobically digested for 76 days in two small-scale digesters sitting by a lab window. The main difference, besides waste sources, of these digesters was substrate processing: chopping versus blending. An effort was made to minimize the maintenance of the digesters, however, after 45 days of overly acidic (pH


Benchtop Minimal-Intervention Anaerobic Digestion Of Vegetarian Food Waste For Ph And Methane Production: Conceivability And Control Study, Emily J. Heleva-Ponaski Jan 2014

Benchtop Minimal-Intervention Anaerobic Digestion Of Vegetarian Food Waste For Ph And Methane Production: Conceivability And Control Study, Emily J. Heleva-Ponaski

Civil and Environmental Engineering Undergraduate Honors Theses

Cities around the world transport large quantities of waste to landfills at a great expense to their residents, infrastructures, and environments. The objective of this study was to run an anaerobic food waste digester with minimal interference or maintenance. One specific goal of this research was to evaluate the relationship between anaerobic food waste and pH. Two benchop digesters were started with vegetarian food waste collected from the Portland State University campus. Measurements were collected over the course of the digestion process. Due to low pH and lack of biogas production, the digesters were buffered with sodium carbonate and seeded ...


The Effect Of The Bicycle Detector Symbol And R10-22 Sign On Cyclist Queuing Position At Signalized Intersections, Stefan W. Bussey Dec 2013

The Effect Of The Bicycle Detector Symbol And R10-22 Sign On Cyclist Queuing Position At Signalized Intersections, Stefan W. Bussey

Civil and Environmental Engineering Undergraduate Honors Theses

The Manual of Traffic Control Devices (MUTCD) includes a roadway marking and accompanying explanatory sign which may be installed on public roads to help guide cyclists position themselves over detection at actuated traffic signals. While adopted into the MUTCD in 2003, little research is available on the effectiveness of the marking and sign. This study evaluates the influence that the roadway marking, roadway marking installed in conjunction with the explanatory sign, and an alternative detector marking comprised of the MUTCD marking installed over a one foot by two feet green rectangle, have on cyclist queuing position at actuated, signalized intersections ...


Carbon Sponsoring: A New Idea In Personal Carbon Trading, Direct Carbon Offset Pledges For Travel, Alexander Y. Bigazzi Apr 2009

Carbon Sponsoring: A New Idea In Personal Carbon Trading, Direct Carbon Offset Pledges For Travel, Alexander Y. Bigazzi

Civil and Environmental Engineering Undergraduate Honors Theses

Public and political consensus expresses the need for broad action to mitigate climate change. To this end, different forms of carbon trading exist to initiate carbon reduction projects. This thesis proposes the idea of carbon sponsoring, a new tool for personal carbon trading. Unlike carbon offsets, the main option for individuals wishing to mitigate their carbon footprint, carbon sponsoring is a purely social instrument involving carbon-reducing pledges. Carbon sponsoring is intended for individuals who seek immediate, direct carbon offsets for their personal emissions. It is not meant as a broad tool correcting the various deficiencies of the carbon trading markets ...