Engineering Commons^™

Anthropogenic Effects On Tidal Distortion In A Tidal River, Matthew D. Fischer

Electronic Theses and Dissertations

Tidal rivers are landward portions of estuarine systems constituting the union between coastal, tidally controlled settings and rivers, where fluvial processes dominate. In these reaches, river discharge (mean flow) and tides are the two most important mechanisms in controlling geophysical flows. The processes governing water levels and current amplitudes in tidal rivers are highly nonlinear and modulated by external forcings- thus requiring sophisticated techniques for accurate prediction and forecasting. Physical oceanographers and estuarine physicists tend to limit their study area to the maximum extent of the horizontal tide (salinity intrusion), not the most landward point influenced by tidal water levels. …

Optimization Of A Lightweight Floating Offshore Wind Turbine With Water-Ballast Motion Mitigation Technology, William Ramsay

Electronic Theses and Dissertations

Floating offshore wind turbines are a promising technology to address energy needs utilizing wind resources offshore. The current state of the art is based on heavy, expensive platforms to survive the ocean environment. Typical design techniques do not involve optimization because of the computationally expensive time-domain solvers used to model motions and loads in the ocean environment. However, this project uses an efficient frequency domain solver with a genetic algorithm to rapidly optimize the design of a novel floating wind turbine concept. The concept utilizes liquid ballast mass to mitigate motions on a lightweight post-tensioned concrete platform, with a target …

On The Application Of Dynamical Measures Of Hydrologic Response To Prediction And Similarity Assessment In Watersheds, Prashanta Bajracharya

Electronic Theses and Dissertations

The Prediction in Ungauged Basins (PUB) initiative set out to improve the understanding of hydrological processes with an aim of improving hydrologic models for application in ungauged basins. With a majority of basins around the world essentially ungauged, this suggests the need to shift from calibration-based models that rely on observed streamflow data to models based on process understanding. This is especially important in natural infrastructure planning projects such as investments in the conservation of wetlands across the watershed, where the lack of streamflow data hinders the quantification of their benefits (such as flood attenuation), resulting in a difficulty in …

Development Of Ultra High Performance Composite Impact Panels Using Emaa, Jeffrey Hollstein

Electronic Theses and Dissertations

UHPC with the addition of fibers is recognized for its increased impact resistance compared to typical strength concrete. To further increase the resilience, recent studies have been conducted to reinforce the UHPC with CFRTP on the front and rear face to create sandwich panels. These studies used PETg/E-glass CFRTP bonded to the UHPC using EMAA (Surlyn) in a stamp thermoforming process. Impact tests conducted on these panels have shown that delamination has been the initial and detrimental failure to the sandwich composite. Increasing the composites resistance to debonding will increase the impact energy required to debond the composite. In this …

Road Salt Use Analysis In The Context Of Changing Winter Weather Conditions, Dikshya Parajuli

Electronic Theses and Dissertations

The research is inspired by the past and current patterns of road salt use, changing weather patterns, and management strategies in Maine. The historical road salt application has led to long-term impacts on the environment pressing the need for strategic use of road salt. Winter Severity Indices (WSIs) find their application in the field by aiding in interpreting weather forecasts and planning for strategic salt application. This study uses existing indices: Accumulated Winter Season Severity Index (AWSSI), Strategic Highway Research Program (SHRP) index, Illinois Salt days index, and Accumulated Freezing Degree Days to quantify long-term changes in winter weather conditions. …

Statistical Analysis Of Frequency And Severity Of Lane Departure Crashes In Maine, Alainie A. Sawtelle

Electronic Theses and Dissertations

Lane departure crashes account for approximately 34% of all roadway crashes, and over 70% of all roadway fatalities in Maine. Despite an 18% decrease in average daily traffic volume during the half of the year with colder weather, the months of November to April comprise over 64% of the yearly lane departure crashes. The majority of roadways and roadway crashes in Maine are in rural regions. Moreover, Maine has aging infrastructure, houses the oldest population in the United States, has diverse terrain and land use, and experiences several extreme weather events. The combination of these factors impacts the frequency and …

Non-Destructive Evaluation Of Concrete Using Electrical Resistivity And Ultrasonic Wave Propagation, Justin Harris

Electronic Theses and Dissertations

With the intent to investigate the relationship between concrete physical properties and non-destructive evaluation techniques (NDE), several experiments were performed. Specimens were made at varying geometries using a range of different concrete mixes under several different curing conditions. These specimens were subjected to a combination of electrical resistivity and ultrasonic wave propagation measurements. One part of this study investigated determining the orientation of steel fibers using electrical resistivity. This resulted in the fabrication of a four-probe square device with the potential capabilities of determining fiber orientation. The other part of this research applied ultrasonic wave propagation via through-transmission along with …

Development Of Thermoplastic Composite External Reinforcing Of Concrete Decking System, Jackman A. Mickiewicz

Electronic Theses and Dissertations

The use of reinforced concrete is very common in the construction of a wide variety of structures. In buildings it is used for floors, beams, columns, and walls. It can also be used in infrastructure as parts of bridges, dams, pavements, etc. Typically, concrete is reinforced with steel, primarily rebar, to carry tensile stresses.

Like every other industry, construction is always looking at ways to advance its technology. The work outlined in this thesis looks to assist in that goal, primarily by looking at options for using a different material than the traditional steel reinforcements to create a reinforced concrete …