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Full-Text Articles in Engineering

Assessment Of Biomass Burning And Mineral Dust Impacts On Air Quality And Regional Climate, Xinyi Dong Dec 2015

Assessment Of Biomass Burning And Mineral Dust Impacts On Air Quality And Regional Climate, Xinyi Dong

Doctoral Dissertations

East Asia is frequently influenced by dust storms and biomass burning. This study conducts a comprehensive investigation of its kind based on data analysis with surface measurements, satellite products, and model simulations. The objective of this study is to improve the understanding of the impacts of biomass burning and dust on air quality and regional climate. The study period covers March and April from 2006 to 2010. Biomass burning from Peninsular Southeast Asia (PSEA) has significant annual variations by up to 60% within the study period. The impact of biomass burning on air quality is mainly confined within the upper …


Removal Of Trace Organic Compounds In Domestic Wastewater Using Recirculating Packed-Bed Media Filters, Brittani Nikole Perez Dec 2015

Removal Of Trace Organic Compounds In Domestic Wastewater Using Recirculating Packed-Bed Media Filters, Brittani Nikole Perez

Masters Theses

Pharmaceuticals and personal care products (PPCPs) are commonly detected in the environment resulting from their survival from conventional wastewater treatment systems. More information is needed about the fate and transfer of these trace organic compounds in domestic wastewater and their associated risks so that efficient strategies for their removal can be developed for both large/small scale treatment systems. This study aimed to determine whether onsite wastewater treatment systems were capable of providing PPCP removal, in addition to quantifying different forms of removal (biodegradation/sorption). A column study was constructed to determine the removal efficiencies of 3 target PPCPs, endocrine disrupting compound …


Non-Residential Pedestrian Access To Transit Systems: A Gis Modeling Application, Luis Miguel Taboada Dec 2015

Non-Residential Pedestrian Access To Transit Systems: A Gis Modeling Application, Luis Miguel Taboada

Masters Theses

The success of a city’s urban transit system relies on the efficacy of its pedestrian infrastructure. A functional and access-oriented pedestrian network translates into safer pedestrian travel, increased demand in transit ridership, increases in commerce patronage, and reduced motorized travel (i.e., less congestion, and less vehicle emissions). Prioritization and allocation of sidewalk construction improvements are not always done in conjunction with transit service provisions. As a result, potential destinations are left inaccessible to pedestrians using the transit system. This study is motivated by concurrent research involving sidewalk improvement prioritization methods, within the scope of home-based work pedestrian transit trips. This …


The Economic Implications Of Evolving Aviation Funding Policy In Tennessee, Hunter Pressley Mccracken Dec 2015

The Economic Implications Of Evolving Aviation Funding Policy In Tennessee, Hunter Pressley Mccracken

Masters Theses

The majority of state funding for capital improvements at Tennessee’s general aviation and commercial airports comes through grants awarded from the Tennessee Transportation Equity Trust Fund (TETF). Through a 4.5 percent sales and use tax on the consumption of aviation fuel, users help to fund the continued improvement and maintenance of aviation facilities around the state. Aircraft refueling operations associated with the FedEx “SuperHub” in Memphis were responsible for two-thirds of the TETF’s revenue for Fiscal Year 2014. In response to speculation that FedEx would relocate its refueling operations to reduce its fuel tax liability, the Tennessee General Assembly passed …


Effect Of Particle Morphology On The Deformation Behavior Of Sand Under Monotonic Loading Conditions, Alexia Rose Leib Dec 2015

Effect Of Particle Morphology On The Deformation Behavior Of Sand Under Monotonic Loading Conditions, Alexia Rose Leib

Masters Theses

When a projectile hits sand, the projectile places high stresses on the sand surface. Granular materials at high stresses are liable to crushing. The pressure at which crushing occurs depends greatly on particle shape and relative density. These parameters also greatly influence the changes in particle shape and size after crushing. Additionally, projectiles fired at extremely high velocities are preceded by a pressure wave. This pressure wave can crush granular material before the projectile ever touches the surface. If the sand has been crushed and its inherent particle properties changed before projectile impact, the projectile may not behave as expected. …


Bankfull Geomorphic Relationships And Hec-Ras Assessment In Small Catchments Of The Cumberland Plateau Ecoregion, Ryan Lee Hodges Dec 2015

Bankfull Geomorphic Relationships And Hec-Ras Assessment In Small Catchments Of The Cumberland Plateau Ecoregion, Ryan Lee Hodges

Masters Theses

There is a great need for state governments to have effective watershed restoration and mitigation efforts to return degraded ecosystems to a stable, healthy condition. Given the growing investment in stream restoration efforts, there is an urgent need for tools to assess and improve the effectiveness of restoration efforts at local, state, and nationwide scales. In 2000 there was less than ten stream restoration permits provided by the state of Tennessee and has increased each year with almost forty permits issued in 2013. To better achieve successful stream restoration, appropriate channel designs must be used that reflect the hydraulic conditions …


Modeling Route Choice Of Utilitarian Bikeshare Users From Gps Data, Ranjit Khatri Dec 2015

Modeling Route Choice Of Utilitarian Bikeshare Users From Gps Data, Ranjit Khatri

Masters Theses

This research examines the behavior of bikeshare users from Grid Bikeshare Program in Phoenix, Arizona under two behavioral frameworks: facility usage assessment and route choice assessment. The analysis is performed for the two different categories of subscribers: registered and casual subscribers. This is the first study that uses the real-time GPS data from bikeshare users to model their route preferences. The data used for this study were obtained from 9,101 trips made by 1,866 bikeshare. An important aspect of this bikeshare is that it allows non-station origin and destinations. The GPS points collected from the trips made by bikeshare users …


Spatial Variation In Fine Sediment And Microbial Transport Along Stream Cross Sections: Implications To Modeling And Monitoring, Thomas Michael Walton Dec 2015

Spatial Variation In Fine Sediment And Microbial Transport Along Stream Cross Sections: Implications To Modeling And Monitoring, Thomas Michael Walton

Masters Theses

Spatial variations in suspended concentrations of fine sediment and indicator bacteria in streams is noted as a source of uncertainty in various applications of water quality datasets. Without proper analysis of the persistence and reasoning for this variance in natural systems, a finer resolution of model calibration is necessary to account for spatial variation in stream cross sections. This level of calibration has become of utmost importance due to technological advancements presenting the ability for water quality modeling frameworks to generate a much finer resolution of outputs. While the importance of model calibration has been noted for remediating levels of …


Modeling Water Age And Disinfection Byproduct Formation In Drinking Water Distribution Systems In East Tennessee, Seth Adam Fischer Aug 2015

Modeling Water Age And Disinfection Byproduct Formation In Drinking Water Distribution Systems In East Tennessee, Seth Adam Fischer

Masters Theses

Chlorine disinfection of drinking waters is responsible for the standard of health we enjoy today and the eradication of waterborne disease. Chlorine also reacts with natural organic matter (NOM) to form disinfection byproducts (DBPs) which have been linked to cancer as well as reproductive and developmental issues. The exact mechanism for formation of regulated DBPs, trihalomethanes (THMs) and haloacetic acids (HAAs), is unknown. The literature has identified relationships between DBP formation and, most notably, characteristics of NOM, chlorine contact time, temperature, pH [negative log of hydrogen ion concentration], and chlorine dose. This study develops models both specific to individual utilities, …


Modeling Water Quality For Switchgrass Crop Production: Implications For Bioenergy Sustainability In East Tennessee, Zachariah Tzvi Seiden Aug 2015

Modeling Water Quality For Switchgrass Crop Production: Implications For Bioenergy Sustainability In East Tennessee, Zachariah Tzvi Seiden

Masters Theses

With passing of the US Energy Independence and Security Act (EISA) of 2007, there has been considerable research conducted on the sustainability of bioenergy crop production in the United States; switchgrass has shown particular potential for bioenergy production in East Tennessee. Many studies evaluating the environmental impact switchgrass has on runoff and water quality use the Soil and Water Assessment Tool (SWAT) for watershed modeling. Because SWAT is a lumped watershed model, it evaluates the result of hydrological processes for each hydrologic response unit (HRU), without accounting for the physical interactions between these HRUs. The Water Erosion Prediction Project (WEPP) …


Durability Of Lightweight Concrete For Bridge Decks, Andrew Mccullough Wagner Aug 2015

Durability Of Lightweight Concrete For Bridge Decks, Andrew Mccullough Wagner

Masters Theses

As concrete durability becomes a higher priority for departments of transportation’s acceptability of concrete for bridge decks, consideration of resistance to the penetration of chloride ions has become a key consideration in defining durability. For years the “Rapid Chloride Ion Penetration (RCP) test has been the accepted standard to measure penetrability of concrete to chloride ions. With the movement to use chloride ion penetrability as a part of acceptance criteria for a concrete mix, use of the newer and easier Surface Resistivity (SR) test as an alternative to the slower, more complicated “Rapid Chloride Ion” test became a desirable option. …


3d Kinematic And Strength Behavior Of Granular Materials At The Particle-Level, Mehmet Burak Cil May 2015

3d Kinematic And Strength Behavior Of Granular Materials At The Particle-Level, Mehmet Burak Cil

Doctoral Dissertations

The macro-scale behavior of uncemented granular materials is governed by the particle-to-particle interactions. Therefore, accurate assessment of the micro-scale mechanics is essential for better understanding of the fundamental behavior of granular materials. Particle fracture phenomenon and force transmission mechanisms in natural granular assemblies such as sands have not been fully understood due to the lack of micro-scale experimental measurements. The objective of this dissertation is to provide key quantitative measurements about these issues using powerful non-destructive experimental 3D x-ray diffraction (3DXRD) and synchrotron micro-tomography (SMT) techniques, as well as distinct element method (DEM). 3DXRD was employed to measure the volume-averaged …


Driving Volatility In Instantaneous Driving Behaviors: Studies Using Large-Scale Trajectory Data, Jun Liu May 2015

Driving Volatility In Instantaneous Driving Behaviors: Studies Using Large-Scale Trajectory Data, Jun Liu

Doctoral Dissertations

Increasing amounts of data, generated by electronic sensors from various sources that include travelers, vehicles, infrastructure and the environment, referred to as “Big Data”, represent an opportunity for innovation in transportation systems and toward achieving safety, mobility and sustainability goals. The dissertation takes advantage of large-scale trajectory data coupled with travel behavioral information and containing 78 million second-by-second driving records from 100 thousand trips made by nearly four thousand drivers. The data covers 70 counties across the State of California and Georgia, representing various land use types, roadway network conditions and population. The trajectories cover various driving practices made by …


Spatio-Temporal Dynamics Of Short-Term Traffic, Jianjiang Yang May 2015

Spatio-Temporal Dynamics Of Short-Term Traffic, Jianjiang Yang

Doctoral Dissertations

Short-term traffic forecasting and missing data imputation can benefit from the use of neighboring traffic information, in addition to temporal data alone. However, little attention has been given to quantifying the effect of upstream and downstream traffic on the traffic at current location. The knowledge about temporal and spatial propagation of traffic is still limited in the current literature. To fill this gap, this dissertation research focus on revealing the spatio-temporal correlations between neighboring traffic to develop reliable algorithms for short-term traffic forecasting and data imputation based on spatio-temporal dynamics of traffic.

In the first part of this dissertation, spatio-temporal …


Self-Learning License Plate Matching Algorithm: Some Enhancements And Its Role In Travel Time Ground Truth Measurements, Stephanie Raven Ann Hargrove May 2015

Self-Learning License Plate Matching Algorithm: Some Enhancements And Its Role In Travel Time Ground Truth Measurements, Stephanie Raven Ann Hargrove

Doctoral Dissertations

Probe vehicle and floating traveler data can provide more detailed information about highway use across a roadway network than traditional transportation data sources. However, there are numerous concerns about accuracy, e.g., road user coverage, locational accuracy, and aggregation methods. To address these concerns, evaluations must be completed using a highly accurate data collection method to capture ideal ground truth. For the purpose of this dissertation, license plate recognition (LPR) technology is considered to be the suitable collection method for, and in lieu of, the all ground truth. The data can be obtained using a pair of mobile LPR units to …


Integrating Engineering And Social Aspects In Selecting Stormwater Control Measures (Scms), Maudy Indriani Budipradigdo May 2015

Integrating Engineering And Social Aspects In Selecting Stormwater Control Measures (Scms), Maudy Indriani Budipradigdo

Masters Theses

The Low Impact Development (LID) approach to stormwater management is rapidly becoming the required replacement for the traditional approach of development design, solely for peak runoff attenuation. Stormwater Control Measures (SCMs) used in LID designs are some combination of physical structures and /or agronomic practices designed to capture runoff, remove pollutants, promote groundwater recharge, and protect receiving streams from channel degradation. The LID approach has been studied and documented in many journals and design manuals, but we know of no comprehensive study that combines the engineering (hydrologic performance requirements) and social aspects (complementary requirements) of the approach. SCMs have historically …


Design And Construction Of A Full-Scale Lateral Impact Testing Facility, Cody Aaron Mitchell May 2015

Design And Construction Of A Full-Scale Lateral Impact Testing Facility, Cody Aaron Mitchell

Masters Theses

The goal of this work is to design and construct a full scale lateral impact testing facility that is capable of recreating the damage that would be created by an overheight vehicle collision. This was accomplished by impacting a test specimen with an 8000 lbs. impact cart. The impact cart is raised on an elevated track and allowed to roll down the track with a change in height of 10 ft. This change in height is what provides the impact force necessary to recreate an overheight vehicle collision. The track is constructed out of wood and is designed to withstand …


Cleveland Sidewalk Studies: Plan For Blythe Avenue Area Sidewalk Extension To 20th Street Se And Plan For Neighborhood Connector Sidewalks To Wildwood Avenue, Thuy Trieu, Kelly Nicholas, Scott Rice, Michael Williams, Heath Sain, Jonathan Reagan May 2015

Cleveland Sidewalk Studies: Plan For Blythe Avenue Area Sidewalk Extension To 20th Street Se And Plan For Neighborhood Connector Sidewalks To Wildwood Avenue, Thuy Trieu, Kelly Nicholas, Scott Rice, Michael Williams, Heath Sain, Jonathan Reagan

Chancellor’s Honors Program Projects

No abstract provided.


Modeling Of Debonding And Crack Propagation In Fibrous Composites Using A Discontinuous Galerkin Approach, Wesley Michael Hicks May 2015

Modeling Of Debonding And Crack Propagation In Fibrous Composites Using A Discontinuous Galerkin Approach, Wesley Michael Hicks

Masters Theses

A recently proposed Discontinuous Galerkin (DG) method for modeling debonding and fracture within the context of the finite element method is investigated for problems relating to fiber reinforced composites, namely fiber-matrix interfacial debonding which progresses to matrix fracture. The results are then compared against an existing intrinsic cohesive zone method and a hybrid Discontinuous Galerkin method. The results show that the method can eliminate the problem of artificial compliance that is associated with intrinsic cohesive zone models. Eliminating this stiffness has the positive effect of removing user-defined numerical parameters that are not actually present in the physical system. A key …