Engineering Commons^™

Use Of International Hydrographic Organization Tidal Data For Improved Tidal Prediction, Songwei Qi

Dissertations and Theses

Tides are the rise and fall of water level caused by gravitational forces exerted by the sun, moon and earth. Understanding sea level variation and its impact currents is very important especially in coastal regions. With knowledge of the tide-generating force and boundary conditions, hydrodynamic models can be used to predict or model tides in coastal regions. However, these models are not sufficiently accurate, and in-situ tide gauge data may be used to improve them in coastal regions. The International Hydrographic Organization (IHO) tidal data bank consists of over 4000 tide gauge stations scattered all around the globe, most of …

Game Theory Approach To Transportation Network Vulnerability Measurement, Qixing Wang

Master's Theses

The vulnerability of a transportation network is strongly correlated with the ability of the network to withstand shocks and disruptions. A robust network with strategic redundancy allows for the redistribution or reassignment of traffic without unduly compromising system performance. As such, high-volume edges with limited alternative paths represent system vulnerabilities – a feature of transportation networks that has been exploited in the past to identify critical components. In this thesis, a mixed-strategy, two opponents, non-zero sum, combinatorial game theoretical framework are presented for measuring network vulnerability. Two solution approaches (Shortest Path Algorithm with Entropy function (SPE) & User Equilibrium Assignment …

Investigation Of In-Situ Immobilization Of Contaminated Sediments Using Alginate Gels For The Reduction Of Ecological Risk, Michael V. Podany Mr.

Master's Theses

Remediation methods for contaminated sediments include dredging, treatment and disposal and sediment isolation through capping. These methods are costly and adversely impact local ecosystems, in some cases causing major disturbances to the sediment bed and water column. A new remediation technique is proposed for slowly biodegradable contaminants using alginate hydrogels as a binding agent of sediment. The rational is that sediment particles bound in alginate hydrogel are less likely to be resuspended and the treatment is less disruptive than capping. Here we show addition of alginate increased the shear strength of sediment comprised of defined particle sizes. The increase in …

Weather-Based Damage Prediction Models For Electric Distribution Networks, David W. Wanik

Master's Theses

From thunderstorms to hurricanes, electric distribution networks are subject to a wide range of warm weather storm events. Tropical Storm Irene (2011) and Hurricane Sandy (2012) are two events in recent memory that disrupted over half of The Connecticut Light and Power Company’s (CL&P) service territory, which left some customers without power for up to eleven days. This research study investigates a damage prediction framework for both thunderstorms and hurricanes that combines two generalized linear models to probabilistically determine the occurrence and extent of damages, known as trouble spots, to the overhead power distribution network. The models are inputted with …

Odor Monitoring At Wastewater Treatment Plants, Natasha Halageri

University of New Orleans Theses and Dissertations

Hydrogen sulfide (H₂S) is notable for its toxicity and corrosion is one of the major sources of odor in wastewater treatment plants. Evaluation of existing or potential odor problems requires knowledge of the type of compounds likely to cause such problems and the mechanism of their formation in wastewater systems which is discussed in this paper. For the present study, the East Bank wastewater treatment plant was chosen since it is the largest wastewater treatment facility within Jefferson Parish, Louisiana. To combat the odor problems in this facility, a monitoring program was designed and developed to characterize the …

Environmental Justice Ties To Electronic Travel Surveys And Transit Accessibility, Nicholas A. Hart

Master's Theses

No abstract provided.

Structural Design Of Flexible Etfe Atrium Enclosures Using A Cable-Spring Support System, Ryan Paul Bessey

Theses and Dissertations

This research designed and analyzed an innovative structural support system for ETFE (ethylene tetrafluoroethylene) atrium roofs between buildings. A cable-spring system was conceived, which is much lighter and more flexible than arches, frames, trusses, and beams which usually support ETFE roofs. Flexibility was a desirable property because the displacements may vary significantly among the buildings supporting the ETFE atrium roof during wind and seismic loading. The springs in the cable-spring system allow large differential displacements without exerting large support reactions on the buildings. The flexibility of the cable-spring system was compared to the cable-strut system which is used to support …

Complexity Of Bed-Load Transport In Gravel Bed Streams: Data Collection, Prediction, And Analysis, Darren D. Hinton

Theses and Dissertations

Bedload transport has long been known for its complexity. Despite decades of research, significant gaps of understanding exist in the ability to assess and predict bedload movement. This work introduces a comprehensive bedload database that is a compilation of field samples collected over the past 40 years; compares prediction formulae using a subset of the database; evaluates the influence of the armor layer on stream response to sediment input based on a hypothesis linked to one of the tested formulae, presents a mathematically manipulation of the empirical Pagosa Good/Fair formula for bedload transport into a format similar to the semi-empirical …

Impact Of Bioparticle Recirculation In A Circulating Fluidized Bed Biofilm Reactor On Simultaneous Organic And Nitrogen Removal, Ming Li

Electronic Thesis and Dissertation Repository

The Circulating Fluidized Bed Biofilm Reactor (CFBBR), a bioparticle technology designed for biological nutrient removal, has been implemented to achieve considerable biodegradation efficiency and low sludge production, compared with activated sludge system and typical biofilm technology. The inherent advantages of bioparticle technology are enhanced substantially by the CFBBR, for example, decoupling of hydraulic retention time (HRT) from solids retention time (SRT), large specific surface area, ideal conditions for biofilm ecosystem.

In this work, bioparticle recirculation, as a novel control method for bioparticle system, was demonstrated in CFBBRs. To verify the impact of bioparticle recirculation on the reactor performance, bio-kinetics and …

Passive And Semi-Active Structure-Multiple Tuned Liquid Damper Systems, Islam Soliman

Electronic Thesis and Dissertation Repository

The resonant vibration motion of tall buildings due to dynamic loading, such as wind storms and earthquakes, can be reduced by adding passive dynamic vibration absorbers (DVAs). A single sway mode of vibration is usually considered, however, for certain structures, multiple modes may need to be suppressed. Furthermore, the location of the TLD on the floor plate is important for certain modes, such as the torsional mode. As a result, a three dimensional finite element structure-TLD system model capable of dynamically analyzing a 3D structure is developed and validated. Two different nonlinear TLD models are considered. A full dynamic analysis …

Topographic Influences On Trends And Cycles In Nutrient Export From Forested Catchments On The Precambrian Shield, Samson G. Mengistu

Electronic Thesis and Dissertation Repository

This dissertation explored topographic controls on spatial and temporal patterns in water yield and nutrient (carbon, nitrogen and phosphorus) export from forested headwater catchments in the Turkey Lakes Watershed in central Ontario, where other factors contributing to differences in water yield and nutrient export, including climate, geology, forest, and soils, are relatively constant. Topographic characteristics, including (a) hydrological flushing potential (expansion of water table into nitrate-N producing areas); (b) hydrological storage potential (area of wetlands, which can alternatively allow water and nutrients to bypass wetlands when storage capacity is filled with water or to trap them when not filled); and …

Best Practices Using Building Information Modeling In Commercial Construction, Simon Beveridge

Theses and Dissertations

There has been an increase in adoption of building information modeling (BIM) by commercial contractors over the past few years but there is not a clear indication of current application or the frequency of each use. This research was undertaken to determine the frequency and best practices of using BIM in commercial construction. Leading commercial contracting firms were contacted and employees were selected to complete a telephone survey that was designed to determine how they are using BIM. It was found that BIM is being used with more frequency on projects, with plans to continue to implement it even further …

Wind Field Measurements Around Photovoltaic Panel Arrays Mounted On Large Flat-Roofs, R Nicolas Pratt

Electronic Thesis and Dissertation Repository

An investigation of the wind field around roof-mounted PV arrays has been undertaken, utilizing synchronized TR-PIV and pressure measurements, in order to better understand the mechanisms which result in the aerodynamic loads, most importantly uplift, which act on such arrays. The mean flow is not significantly altered above the array as compared to a bare roof, while Reynolds normal and shear stresses are markedly reduced. Increasing the tilt angle of the array results in a progression from uplifts driven by vortex induced suction, which cause peak uplifts on a bare roof, towards uplifts which are driven primarily by local flow …

Two-Refinement By Pillowing For Structured Hexahedral Meshes, J. Bruce Malone

Theses and Dissertations

A number of methods for adaptation of existing all-hexahedral grids by localized refinement have been developed; however, none ideally fit all refinement needs. This thesis presents the structure to a method of two-refinement developed for conformal, structured, all-hexahedral grids that offers flexibility beyond what has been offered to date. The method is fundamentally based on pillowing pairs of sheets of hexes. This thesis also suggests an implementation of the method, shows the results of examples refined using it and compares these results to results from implementing three-refinement on the same examples.

Seismic Response Of Stiffening Elastic Systems, Andrew Scott Morgan

Theses and Dissertations

Traditional seismic load resisting systems in buildings are designed to undergo inelastic deformations in order to dissipate energy, resulting in residual displacements. This work explores an approach to eliminate these residual displacements. The systems investigated have low initial stiffness which increases at a predefined displacement, and are therefore called stiffening elastic systems. This thesis begins with an examination of single-degree-of-freedom stiffening elastic systems. A case study is presented which suggests that the benefits from stiffening elastic behavior may be limited to systems which would have long periods if designed traditionally. A thorough parameter study is also presented which indicates the …

Electric Vehicles In China: Emissions, Health Impacts, And Equity, Shuguang Ji

Doctoral Dissertations

E-bikes in China are the single largest adoption of alternative fuel vehicles in history, with more than 100 million e-bikes purchased in the past decade and vehicle ownership about 2× [time] larger for e-bikes as for conventional cars; e-cars sales, too, are rapidly growing. Electric vehicles (EVs) in China are being considered as a strategy to improve air quality, energy efficiency, and reduce health impacts due to transport emissions. Because EVs have different pollution sources, namely electric generating units (EGUs), quantitative analysis for health impacts requires understanding the exposure efficiency of related pollution sources. In this dissertation, EVs will be …

Investigating The Prediction Of High Resolution Heat Waves And Extreme Precipitation And The Impact Of Heat Waves On Air Quality In U.S. In The 21st Century, Yang Gao

Doctoral Dissertations

In this study, the perennial problem of scale is addressed with an updated set of modeling tools that include global climate, atmospheric chemistry simulation, mesoscale weather, and air quality simulations. The evaluation of coupled model performance across geographic scales and the assessment of local scale climate change impacts under a fossil fuel intensive climate change scenario Representative Concentration Pathway (RCP 8.5) was achieved by linking the global climate model Community Earth System Model (CESM), with the regional climate model Weather Research and Forecasting (WRF) Model. This study is the first evaluation of dynamical downscaling using WRF on a 4km by …

Stiffness-Driven Design And Interface Debonding Study Of Frp Sandwich Structures For Bridges, Wenchao Song

Doctoral Dissertations

Bridge decks entirely made of fiber reinforced polymer (FRP) materials are a potential solution to fast construction in bridge engineering. This study mainly focuses on the stiffness-driven design of FRP decks for short-span slab bridges and the interface debonding of an FRP sandwich structure with honeycomb cores. As is evidenced by the analytical and experimental results in this study, these two topics are closely related to the application of FRP materials in bridge deck construction. The design verification of an FRP slab bridge showed that its design should be controlled by stiffness rather than strength. The tests of the FRP …

Pervious Pavement Infiltrometer, Madeline Musgrove

BioResource and Agricultural Engineering

This project tests infiltration rates on three different slabs of pervious pavement. A methodology was put in place to ensure that all three slabs were tested the same way. The test that is used for the infiltration rates is a constant head test. A steel ring is placed on the surface of the pervious pavement and sealed with Plumbers Putty around the bottom of the ring. A mark is then sketched on the inside of the ring at 2 inches above the surface of the pavement for a constant backpressure that is equal in all scenarios. Five gallons of water …

Investigation Of Out-Of-Plane Properties Of Interlocking Compressed Earth Block Walls, Nicholas Anthony Herskedal

Master's Theses

Interlocking compressed earth blocks (ICEBs) are cement stabilized soil blocks that allow for dry stacked construction. The incomplete understanding of the inelastic performance of ICEB building systems limits widespread acceptance of this structural system in earthquake prone areas. This thesis presents results from an experimental program designed to explore the behavior of ICEB walls, built according to current design practice in Indonesia and Thailand, and subjected to out-of-plane loading. A total of five reinforced and grouted ICEB walls were constructed and tested.

Results from experimentation show the current masonry design code, ACI 530, adequately predicts the yield strength of these …

Prestress Losses In Lightweight Self-Consolidating Concrete, Jared Bymaster

Graduate Theses and Dissertations

While much research has been performed on lightweight concrete and self-consolidating concrete (SCC), the knowledge of prestress losses in lightweight self-consolidating concrete (LWSCC) is still limited. LWSCC has the benefits of increased flowability, reduced placement labor, and decreased shipping cost compared to conventional concrete. This research program included the study of 14 SCC beams cast with expanded clay, expanded shale, and limestone aggregates. Strains in the beams were measured with vibrating-wire strain gages, and the measured prestress losses were compared with current AASHTO methods for calculating prestress losses. The AASHTO approximate method better predicted actual losses than did the AASHTO …

Development Of Mems-Based Corrosion Sensor, Feng Pan

Graduate Theses and Dissertations

This research is to develop a MEMS-based corrosion sensor, which is used for monitoring uniform, galvanic corrosion occurring in infrastructures such as buildings, bridges. The corrosion sensor is made up of the composite of micro/nano metal particles with elastomers. The mechanism of corrosion sensor is based on the mass transport of corrosive species through the sensor matrix. When the metal particles in the matrix corrode, the electrical resistivity of the material increases due to increasing particle resistances or reduction of conducting pathways. The corrosion rate can be monitored by detecting the resistivity change in sensing elements. The life span of …

Comprehensive Drainage Study Of The Upper Reach Of College Branch In Fayetteville, Arkansas, Kathryn Lea Mccoy

Graduate Theses and Dissertations

College Branch is a stream with headwaters located on the University of Arkansas campus. The stream flows through much of the west side of campus, gaining discharge and enlarging its channel as it meanders to the south. College Branch has experienced erosion and flooding issues in recent years due to increased urbanization of its watershed and increased runoff volume.

The purpose of this project was to develop a comprehensive drainage study of College Branch on the University of Arkansas campus. Storm runoff and flood flow patterns were evaluated in order to understand the hydraulics and hydrology of the watershed and …

Implementing Conductive Concrete With Photovoltaic Energy To Develop Anti-Icing Airfield Runways, Adam Benjamin Osweiler

Graduate Theses and Dissertations

Snow and ice accumulation on airport runways force airports to cancel or significantly delay flights. Winter weather can also drastically affect airport safety during times of aircraft takeoff and landing. During these times, countless dollars are used to remove snow and return airports to their functional conditions. In this thesis, a conductive concrete solar energy system will be examined in order to prevent snow and ice accumulation. The objective of this research is to implement a conductive concrete overlay system on airport runways in conjunction with photovoltaic energy so that no frost precipitation accumulates on the runway surface.

New Framework And Decision Support Tool To Warrant Detour Operations During Freeway Corridor Incident Management, Jing Mao

Theses and Dissertations

As reported in the literature, the mobility and reliability of the highway systems in the United States have been significantly undermined by traffic delays on freeway corridors due to non-recurrent traffic congestion. Many of those delays are caused by the reduced capacity and overwhelming demand on critical metropolitan corridors coupled with long incident durations. In most scenarios, if proper detour strategies could be implemented in time, motorists could circumvent the congested segments by detouring through parallel arterials, which will significantly improve the mobility of all vehicles in the corridor system. Nevertheless, prior to implementation of any detour strategy, traffic managers …

Estimation Of Solute Fluxes From Ungaged Headwater Catchments In The Catskill Park Of New York State, Chris Gianfagna

Civil and Environmental Engineering - Theses

Predictions of flow and subsequent solute fluxes from ungaged basins have important implications both for water resources management and ecosystem monitoring studies. The Catskill region of New York State is one such place that requires both water resources management and ecosystem monitoring due to its strategic location as the main water-supplying region for New York City. This study examines the differences in chemical mass flux estimates made in ungaged basins using three different chemistry aggregation methods for solute concentrations determined from monthly grab samples. The efficacy of area ratios for predicting flow at the upstream location of a nested pair …

Spatial Patterns Of Mercury In Atmospheric Deposition, Soils And Lake Biota In The Adirondack Park, New York, Xue Yu

Civil and Environmental Engineering - Dissertations

Mercury (Hg), as a trace element cycling in the environment, poses a serious health threat to both humans and wildlife due to its toxicity. Atmospheric deposition is the main source of Hg to most remote environments. The Adirondack Park in New York State of the United States receives moderate Hg deposition, and is a region characterized by relatively high concentrations of Hg in the terrestrial and especially aquatic biota. It is important to understand the mechanisms that contribute to the sensitivity of this region to Hg inputs. In my research, studies of the spatial patterns of Hg in atmospheric deposition, …

Performance And Cost Analysis Of A Structured Concrete Thermocline Thermal Energy Storage System, Matt Nicholas Strasser

Graduate Theses and Dissertations

Increasing global energy demands and diminishing fossil fuel resources have raised increased interest in harvesting renewable energy resources. Solar energy is a promising candidate, as sufficient irradiance is incident to the Earth to supply the energy demands of all of its inhabitants. At the utility scale, concentrating solar power (CSP) plants provide the most cost-efficient method of harnessing solar energy for conversion to electrical energy. A major roadblock to the large-scale implementation of CSP plants is the lack of thermal energy storage (TES) that would allow the continued production of electricity during the absence of constant irradiance. Sensible heat TES …

Hydraulic Modeling: Pipe Network Analysis, Trevor T. Datwyler

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Water modeling is becoming an increasingly important part of hydraulic engineering. One application of hydraulic modeling is pipe network analysis. Using programmed algorithms to repeatedly solve continuity and energy equations, computer software can greatly reduce the amount of time required to analyze a closed conduit system. Such hydraulic models can become a valuable tool for cities to maintain their water systems and plan for future growth. The Utah Division of Drinking Water regulations require cities to maintain hydraulic models of their culinary water systems, and before additional connections can be made to the water system, a licensed professional engineer must …

Utilization Of Rainwater As A Supplementary Water Source For Cooling Tower Makeup: A Sustainability Strategy For Potable Water Use Reduction, Elizabeth Stassun Costello

Masters Theses

The use of rainwater as a supplementary water source for cooling water makeup was explored in an effort to reduce the potable water demand of theUniversityofTennessee’sKnoxvillecampus. A water quality analysis involving the measurement of parameters relevant to cooling tower operation was conducted on tap water currently used for makeup supply and rainwater collected from the roof of a campus building. In anticipation of limited rainwater supplies due to issues of catchment surface area, collection efficiency, storage capacity, and climatic conditions, blends of rainwater and tap water were also analyzed. The dissolved solids concentration of the rainwater was significantly lower than …