Engineering Commons^™

Long-Term Trends In Water Quality For A High-Elevation Stream In The Great Smoky Mountains National Park: Impacts Of Acid Deposition, Angela Vanessa Smith

Masters Theses

In the Southern Appalachians, high-elevation streams with small watershed areas tend to be sensitive to acid deposition (Deviney et al., 2006; Cook et al., 1994) because high elevations tend to have more cloud contact, leading to greater atmospheric deposition of pollutants containing sulfate and nitrate acids (Lovett and Kinsman 1990). In a recent study by Webb et al. (2004) examined the link between atmospheric acid deposition and stream water quality in brook trout (Salvelinus Fontinalis) streams in western Virginia and Shenandoah National Park (SNP). The study acknowledged that water quality improvement had been seen in response …

Evaluation Of A New Method To Estimate The Micropore Volume And External Surface Area Of Single-Walled Carbon Nanotubes, Yijing Zheng

Masters Theses

Since the discovery of carbon nanotubes in 1991, significant progress has been made to understand their electrical, mechanical, magnetic and optical properties. However, as the ideal adsorbent for adsorption of gases and vapors, nanotubes, especially the single-walled carbon nanotubes (SWNTs), and their adsorption properties remain not been investigated enough. The unique microporous structure of SWNTs gives them remarkable adsorption properties, i.e. surface area and porosity. Several methods exist to determine the surface area and pore volume of adsorbents: t-plot method, Dubinin-Radushkevich (DR) method, and Dubinin-Astakhov (DA) method. The results are usually specific to a certain method and to the segment …

Use Of The Annagnps Pollutant Loading Model For Prediction Of Sediment Yields In A Mountainous Cumberland Plateau Region: Correlations With The Stream Bed Sediment Characteristics, Michael Patrick Massey

Masters Theses

This study attempts to develop a relationship with the hillslope sediment yield (estimated from a computer model) and the deposited sediment particle size characteristics within stream channels. By using specific hydrological parameters within a watershed, a calibrated Annualized Agricultural Non-Point Source (AnnAGNPS) pollutant loading model was created for four different sub-watersheds in the mountainous New River Basin of eastern Tennessee. The AnnAGNPS pollutant loading model predicted daily runoff and sediment yield reasonably well, but it poorly predicted daily peak flow rate for most sub-watersheds analyzed in the New River Basin. Overall, the AnnAGNPS pollutant loading model provided satisfactory results in …

Comparing In Situ Submerged Jet Test Device And Laboratory Flume Methods To Estimate Erosional Properties Of Cohesive Soils For Bank Stability Models, Tara Liyana Mallison

Masters Theses

In order to accurately predict the stability of riverbanks, model input parameters must be reliable bank failure estimators. Currently, bank stability models require two input parameters to predict bank erosion: critical erosion shear stress and erodibility coefficient. The investigation’s purpose was to compare two erosion estimation methods and improve the bank stability models for cohesive soil commonly found on the banks.

To accomplish the objective, critical shear stresses and erodibility coefficients obtained using the in situ submerged jet test device (SJT) were measured against results from the closed-loop laboratory flume method for 12 cohesive bank sites. Additionally, SJT critical shear …