Engineering Commons^™

Developing An Adaptable Best Value Contractor Selection Tool For Federal Construction Projects, Robert B. Kitson

Theses and Dissertations

Currently, there is no Air Force-wide best practice or standard for using an other-than lowest price source selection process for construction projects. Installations often award contracts using Lowest Price Technically Acceptable (LPTA) because of perceived cost and time savings. However, a heavy reliance on LPTA often leads to long-term decreases in quality and value. To allow the Air Force to receive the best value for its construction funding, a simple and adaptable tool was developed that allows installations to pursue contractor selection for construction projects by other-than lowest price methods. This research conducted a systematic literature review to obtain a …

A Scientometric Analysis Of Smart Sensors In Facility Management And Applications In Air Force Operations, Joseph-Thomas H. Lehotsky

Theses and Dissertations

To investigate the areas which smart sensors can be implemented to assist facility managers to optimize limited resources, this research consists of a scientometric analysis to identify the areas of research quantitatively and qualitatively. Existing literature related to smart sensors in facility management operations were compiled and trends were analyzed to determine the ways in which researchers have been applying this technology. The title, abstracts, and keyword were used to perform frequency, networking, and clustering analysis. This research effort serves to provide ways in which Air Force installations can implement smart sensors in a way which fulfills the initiatives posed …

A Post-Disaster Construction Portfolio Optimization Framework For Tyndall Afb Rebuild Post Hurricane Michael, Andre J. May

Theses and Dissertations

Natural disasters such as hurricanes, earthquakes, tsunamis, and extreme flooding cause severe social and economic disruptions. Restoration of social and revenue-generating services often requires extensive reconstruction, from the facility to the campus scale. For multi-facility portfolios, decision-makers must prioritize post-disaster reconstruction activities appropriately to ensure facilities and infrastructure are restored. In addition, any expansion or new construction initiatives are ideally completed in order of decision-maker and community preference. Most post-disaster optimization and decision framework research consider a single stakeholder as guiding decisions related to a project portfolio. However, these portfolio prioritization frameworks ignore the effect of multiple stakeholders and competing …

Application Of Machine Learning Models With Numerical Simulations Of An Experimental Microwave Induced Plasma Gasification Reactor, Owen D. Sedej

Theses and Dissertations

This thesis aims to contribute to the future development of this technology by providing an in-depth literature review of how this technology physically operates and can be numerically modeled. Additionally, this thesis reviews literature of machine learning models that have been applied to gasification to make accurate predictions regarding the system. Finally, this thesis provides a framework of how to numerically model an experimental plasma gasification reactor in order to inform a variety of machine learning models.

Infrastructure Decision-Making Under Climate Change Uncertainty: Case Study Of Centralized Heating At Wright-Patterson Afb, Ohio, Tyler A. Ferry, Justin D. Delorit, Christopher M. Chini

Faculty Publications

Increased prevalence, lower cost, and reduced environmental impacts have granted natural gas status as a bridge fuel over the past decade in place of coal-fired heat and power generation across the United States. As a result, some coal facilities are retrofitting their systems to combust natural gas for heating and power. However, data and economic criteria surrounding these decisions are not widely available. Wright-Patterson Air Force Base (WPAFB) invested approximately $25 million, from 2014 to 2016, to retrofit two coal-fired steam-heat-generating plants with natural gas equipment. Economic analyses used to inform these long-term infrastructure decisions rarely consider the uncertainty of …

Development Of Intensity-Duration-Frequency (Idf) Models For Manually Operated Rain Gauge Catchment: A Case Study Of Port Harcourt Metropolis Using 50 Years Rainfall Data, Francis Ogbozige

Tanzania Journal of Engineering and Technology (TJET)

Hydraulic structures such as surface drainages and culverts are usually constructed in urban areas with the intention of draining runoff into nearby streams and rivers in order to avoid flooding. However, most of these structures frequently fail to serve the intended use due to the occurrence of high intensity rainfall accompanied with long duration, which produce runoff discharge higher than their designed capacities. This is common in many developing countries as drainages and culverts are most times constructed without considering hydrological analysis of the catchment. Hence, this research considered Port Harcourt city as a case study by utilizing 50 years …

Chlorine Taste Threshold And Acceptability As A Water Disinfectant Among Indigenous Ngäbe And Non-Indigenous In Rural Panama, Ashley Osler

USF Tampa Graduate Theses and Dissertations

More than two billion people globally still lack access to safely managed drinking water (WHO & UNICEF, 2021). Although gains in access to water service over the past two decades have been large, universal access to safe and affordable drinking water (SDG 6, target 6.1) is not on track to be achieved. In Panama, safely managed drinking water access has not been measured. However, the data on basic water access illustrates the large disparities between rural and urban areas of Panama. While 98% of urban Panamanian households have basic access to water, only 86% of rural Panamanian households, and 54% …

Efficacy Of Softener For Enhancing Fatigue And Low-Temperature Performance Of Asphalt Binders With High Rap, Sumon Roy

Student Theses and Dissertations

The use of a higher percentage of reclaimed asphalt pavement (RAP) in asphalt concrete can lead to developing premature failure of asphalt pavements due to fatigue and/or low-temperature cracking. The incorporation of softening agents in asphalt binders can resolve these problems and enhance pavement durability. This study aims to evaluate the effectiveness of waste-based softening agents for enhancing the properties of asphalt mixes with high RAP contents. Waste cooking oil (WCO), and engine bottom oil (EBO) along with a commercial rejuvenator were investigated in this study. Three types of Performance Grade (PG) binders, each collected from two different sources, used …

Predicting Seismic Site Coefficients For Northeast Arkansas (Nea) By Performing Site Specific Ground Motion Response Analysis (Ssgmra), Md Radiue Islam

Student Theses and Dissertations

Northeast Arkansas (NEA) has a deep deposition of soil overlying the bedrock. The code-based design approach e.g., the American Association of State Highway and Transportation Officials (AASHTO) does not account for deep deposition of soil overlying the bedrock. As a result, structures with short-period spectral accelerations are overdesigned at significant cost, and structures with long-period spectral accelerations are under-designed at significant risk. The purpose of this study is to perform SSGMRA for areas in NEA and predict seismic site factors. Seismic hazard analyses have been carried out, and one dimensional (1D) site response analysis has been performed for seven different …

Influence Of Supplementary Cementitious Material (Scm) On Concrete Durability (Drying Shrinkage And Alkali-Silica Reactivity), Raiyan Chowdhury

Student Theses and Dissertations

This study investigates the long-term durability of concrete by replacing cement (10%, 20%, and 30%) with four potential Supplementary Cementitious Material (SCMs), namely, Reclaimed Fly Ash (RFA), Ground Bottom Ash (GBA), Class F Fly Ash (FA), and Metakaolin® (MK). For long-term durability, drying shrinkage and alkali-silica reactivity (ASR) tests were performed along with workability (slump) and compressive strength tests. The FA and RFA demonstrated better workability compared to GBA, MK, and combined mixes (RFA-MK or GBA-MK). The GBA and RFA modified specimens exhibited better compressive strength than other SCMs. Modifying concrete mix with SCMs lowered the ASR expansion than the …

Increasing Heat-Stress Inequality In A Warming Climate, Mohammad Reza Alizadeh, John T. Abatzoglou, Jan F. Adamowski, Jeffrey P. Prestemon, Bhaskar Chittoori, Ata Akbari Asanjan, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Adaptation is key to minimizing heatwaves' societal burden; however, our understanding of adaptation capacity across the socioeconomic spectrum is incomplete. We demonstrate that observed heatwave trends in the past four decades were most pronounced in the lowest-quartile income region of the world resulting in >40% higher exposure from 2010 to 2019 compared to the highest-quartile income region. Lower-income regions have reduced adaptative capacity to warming, which compounds the impacts of higher heatwave exposure. We also show that individual contiguous heatwaves engulfed up to 2.5-fold larger areas in the recent decade (2010–2019) as compared to the 1980s. Widespread heatwaves can overwhelm …

Evaluation Of Gev Over Lp3 When Predicting Return Period Annual Exceedance For Santa Ana, San Gabriel And Urbanized Regions In California, Maria Beatriz De Paula Macedo

LMU Theses and Dissertations

The objective of this present thesis was to determine whether GEV (Generalized Extreme Value) itself can be a more conservative distribution than LP3 (Log Pearson III) associated with other methods, such as the B17B weighting procedure with Single Grubbs-Beck (SGB) for low outliers, when determining the projected floods in a flood frequency analysis (FFA) for Santa Ana and San Gabriel regions and other urbanized stream gages present in California. In this work, USGS PeakFQ was utilized. From the results obtained, it was possible to state that GEV fitting results were directly affected by the length of the data. When the …

Glycerol-Driven Denitratation: Process Kinetics, Microbial Ecology, And Operational Controls, Matthew Baideme, Chenghua Long, Luke Plante, Jeffrey A. Starke, Michael A. Butkus, Katrik Chandran

Civil and Environmental Engineering Faculty Research and Publications

Denitratation, the selective reduction of nitrate to nitrite, is a novel process and when coupled with anaerobic ammonium oxidation (anammox) could achieve resource-efficient biological nitrogen removal of ammonium- and nitrate-laden waste streams. Using a fundamentally-based, first principles approach, this study optimized a stoichiometrically-limited, glycerol-driven denitratation process and characterized mechanisms supporting nitrite accumulation with results that aligned with expectations. At the optimal influent chemical oxygen demand to nitrate ratio of 3.0 : 1 identified, glycerol supported selective nitrate reduction to nitrite (nitrite accumulation ratio, NAR = 62%) and near-complete nitrate conversion (nitrate reduction ratio, NRR = 96%), indicating its viability in …

Blast Analysis Of Steel-Plate Composite Slabs: Sdof And Fem Analyses, Joshua R. Harmon, Amit H. Varma

Bowen Laboratory Research Reports

Steel-plate composite (SC) members have emerged as competitive construction methods for tall buildings and nuclear power plants. Detailed design guidance has been created for these functions and design of these members is now covered in AISC 341-16 and ASIC N690-18. However, SC members are emerging for use in protective structures to withstand blast and impact loads. Although experimental tests of SC members for blast resistant design have been conducted, design of SC members for blast loads has not been addressed in existing design references for blast loadings (UFC 3-340-02). This report details a general design philosophy for blast loaded SC …

Numerical Investigation On Blast Response Of Cold-Formed Steel Framing Protected With Functionally Graded Composite Material, Elias Ali

Faculty Scholarship

This paper presents a numerical simulation on the blast response of cold-formed steel (CFS) structural framing system protected with a functionally graded composite material (FGM) panel. The steel frame consists of four CFS studs, which were protected by 12.5 mm thick gypsum, aluminum composite, and FGM composite materials on both sides. The numerical simulation was performed using ABAQUS on a 1.8 m × 2.4 m, overall wall panel exposed to air blast on one side. A 1.0 kg TNT explosive charge placed at four standoff distances (R) of 1.0 m, 1.5 m, 2.0 m, and 2.5 m from the framing …

Collaborative Environmental Approach For Development Of The Lower Laguna Madre Estuary Program Strategic Plan In South Texas, Javier Guerrero, Ahmed Mahmoud, Taufiqul Alam, Augusto Sanchez, Kim D. Jones, Andrew Ernest

Civil Engineering Faculty Publications

The National Estuary Program (NEP) is a promising eco-system based approach to improve the water quality and ecological integrity of estuaries of national importance in the United States. Due to population growth and concomitant development pressure in South Texas, the future of the Lower Laguna Madre (LLM) without an estuary program is problematic. The development of a management plan for the LLM will enable the region to develop local solutions to local problems. The fundamental purpose of this research was to develop a strategic plan for the foundation of the Laguna Madre Estuary Program of the Gulf Coast of Texas. …

Paper Mill Sludge Biochar To Enhance Energy Recovery From Pyrolysis: A Comprehensive Evaluation And Comparison, Zhongzhe Liu, Matthew Hughes, Yiran Tong, William Kreutter, Hugo Cortes Lopez, Simcha L. Singer, Daniel Zitomer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Bio-oil and pyrolysis gas (py-gas) are two pyrolysis products available for potential energy recovery. Crude bio-oil, however, is typically corrosive and unstable, requiring special combustion equipment or catalytic upgrading to produce drop-in-grade fuel. In contrast, py-gas is readily useable in standard equipment for energy recovery. Previous research revealed that Ca-impregnated biochar catalyst improved bio-oil to py-gas conversion. Biochar produced from paper mill sludge (p-sludge) has very high Ca content. In this study, the catalytic ability of p-sludge biochar was systematically evaluated for the first time in pyrolysis. P-sludge biochar resulted in higher py-gas yield (40 wt% of total pyrolysis products) …

Durability Properties Of Concrete With 100 Percent Coarse Recycled Concrete Aggregates, Tasnia Tarannum Khan

Theses and Dissertations

The supplies of concrete aggregates from natural sources are rapidly reducing. Recycled concrete aggregates (RCA) are produced by crushing the concrete obtained from demolished concrete structures. The purpose of this study is to determine the durability properties of concrete with 100% recycled concrete coarse aggregates and relate the durability of such concrete to the physical, mechanical, and durability properties of RCA and the RCA parent concrete. The correlations of several properties are determined by developing model equations to predict RCA properties. The parent concrete is crushed and graded at two nominal maximum sizes, 1" and 0.75", to determine the RCA …

Comparison Of Phosphorus Removal And Recovery Methods And Proposed Design Of High Rate Algal Pond For Swine Wastewater, Taylor Fauth

Civil and Environmental Engineering Graduate Students Plan B Capstone Projects

High phosphorus concentrations in wastewater effluent can have harmful effects to aquatic environments and water quality. An excess of nutrients such as phosphorus in water bodies will cause eutrophication, which depletes the available oxygen within the water and is detrimental to aquatic life. Additionally, phosphorus leaching from wastewater discharge has negative impacts to groundwater quality. The depletion of phosphorus as a natural resource is also of concern as phosphorus is an essential product for agricultural and industrial production. Phosphorus is a non-renewable resource, and natural sources are becoming more difficult and expensive to access. Therefore, the removal and recycle of …

A Systematic Literature Review Exploring The Barriers To Innovative Modular Construction Methods For The International Hyper-Scale Data Centre Sector, Peter E. Lonergan, A.Omar Portillo-Dominguez

Other

Data centres form the essential global infrastructure relied upon for multiple industries such as the internet, financial services, and telecommunications. Consequently, data centre construction has developed into a buoyant business sector, leveraging increasing global investment. However, traditional means of data centre procurement do not match stakeholder’s ambitions or current delivery demands. Thus, there is a need for the adoption of new and innovative construction methodologies in the sector to introduce improvements for the delivery of this essential infrastructure. As a step in that direction, this paper presents a Systematic Literature Review (SLR) that investigates the barriers preventing the implementation of …

Analytical And Experimental Investigation Into Pre-Stressed Carbon Fiber Reinforced Polymer (Cfrp) Fatigue Retrofits For Steel Waterway Lock-Gate Structures, Christina Lozano, Maggie Langston, Mohammad H. Kashefizadeh, Gary S. Prinz

Civil Engineering Faculty Publications and Presentations

Lock gates are an important part of the transportation infrastructure within the United States (US). Unfortunately, many existing lock gates have reached or exceeded their initial design lives and require frequent repairs to remain in service. Unscheduled repairs often increase as gates age, having a local economic impact on freight transport, which can create economic ripples throughout the nation. Metal fatigue is a key cause of unscheduled service interruptions, degrading lock gate components over time. Additionally, because lock gates are submerged during operation, crack detection prior to component failure can be difficult, and repair costs can be high. This paper …

Multiphysics Numerical Modeling Of Transient Transport Of Pfas, Pierrette Iradukunda, Arvin Farid

Civil Engineering Faculty Publications and Presentations

The need to understand the fate and transport of Per- and Polyfluoroalkyl substances (PFAS) has grown due to the widespread contamination of the environment by them. PFAS are persistent, mobile, toxic manmade chemicals of great concern that contribute to the contamination of soil and groundwater. The presence of PFAS in unsaturated soil complicates their transport due to the impact of the air–water interface and solid-phase adsorption. The air–water interface can significantly increase the retention of PFAS during its transport. In this paper, a numerical model has been developed to study the transport of PFAS by coupling transient seepage and advection-dispersion, …

The Role Of Ball Backspin Alignment And Variability In Basketball Shooting Accuracy, Nathan Slegers, Dave Love

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Interaction between the shooting hand and ball at the moment a basketball is released generates a three dimensional backspin of the ball. This study is the first to investigate how characteristics of the backspin alignment and variability contribute to lateral shooting accuracy. Spin axis (SA) direction and backspin magnitude were measured on 25 shot attempts for 26 collegiate basketball players (male: n = 16, female: n = 10). The mean SA alignment, as viewed from the shooting hand side, was found to be tipped down and towards the target (p < 0.001). Standard deviations (SD) in the SA alignment were strong predictors of lateral accuracy (vertical SD: r = 0.80, p < 0.001, forward-backward SD: r = 0.51, p = 0.01), with variation in the vertical alignment being the best predictor. No significant correlation between mean SA misalignment and lateral accuracy was observed. However, intra-individual relationships between SA misalignment and lateral error revealed that individuals tended to have 0.17 degrees more misalignment for each cm of lateral error (p < 0.001, 95% CI: 0.24–0.09). These indicate that while an individual’s mean alignment may not predict lateral accuracy, improving one’s SA alignment and reducing alignment variability may increase lateral accuracy.

Detecting And Tracking Vulnerable Road Users' Trajectories Using Different Types Of Sensors Fusion, Zhongchuan Wang

Electronic Theses and Dissertations, 2020-2023

Vulnerable road user (VRU) detection and tracking has been a key challenge in transportation research. Different types of sensors such as the camera, LiDAR, and inertial measurement units (IMUs) have been used for this purpose. For detection and tracking with the camera, it is necessary to perform calibration to obtain correct GPS trajectories. This method is often tedious and necessitates accurate ground truth data. Moreover, if the camera performs any pan-tilt-zoom function, it is usually necessary to recalibrate the camera. In this thesis, we propose camera calibration using an auxiliary sensor: ultra-wideband (UWB). USBs are capable of tracking a road …

High Fidelity Injury Severity Analysis Using Econometric Modeling Approaches, Ahmed Kabli

Electronic Theses and Dissertations, 2020-2023

Crash severity models are typically developed using police reported injury severity databases. However, several research studies have identified various challenges associated with police reported data. Therefore, the current dissertation is focusing on developing high resolution crash severity models based on medical professional driver injury severity reported using Abbreviated Injury Scale for eight body regions. The dissertation focused on developing a disaggregate injury severity modeling framework that can enhance the estimation accuracy of independent variable impacts on severity. Within this broad research vision, the dissertation has multiple objectives. First, a joint random parameters multivariate model structure with as many dimensions as …

Machine Learning Algorithms For Forecasting The Impacts Of Connected And Automated Vehicles On Highway Construction Costs, Amirsaman Mahdavian

Electronic Theses and Dissertations, 2020-2023

A multitude of externalities affects transport efficiency and numbers of trips. Population expansion, urban development, political issues, fiscal trends, and growth in the field of connected, automated, shared, and electric (CASE) vehicles have all played prominent roles. While the market is keenly aware of the upcoming shift to the CASE vehicles, the transformation itself is reliant upon the development of technologies, customer outlook, and guidelines. The purpose of this research is to establish an overview of the possible network design problems, as well as potential consequences to vehicle automation systems by employing machine learning and system dynamics analysis. Finally, the …

A Spatiotemporal Evaluation Of Freeway Traffic Demand In Florida During Covid-19 Pandemic, Md Istiak Jahan

Electronic Theses and Dissertations, 2020-2023

This thesis contributes to our understanding of the changes in traffic volumes on major roadway facilities in Florida due to COVID-19 pandemic from a spatiotemporal perspective. Three different models were tested in this study- a) Linear regression model, b) Spatial Autoregressive Model (SAR) and c) Spatial Error Model (SEM). For the model estimation, traffic volume data for the year 2019 and 2020 from 3,957 detectors were augmented with independent variables, such as- COVID-19 case information, socioeconomics, land-use and built environment characteristics, roadway characteristics, meteorological information, and spatial locations. Traffic volume data was analyzed separately for weekdays and holidays. SEM models …

Accuracy And Uncertainty In Traffic And Transit Ridership Forecasts, Jawad Mahmud Hoque

Theses and Dissertations--Civil Engineering

Investments of public dollars on highway and transit infrastructure are influenced by the anticipated demands for highways and public transportations or traffic and transit ridership forecasts. The purpose of this study is to understand the accuracy of road traffic forecasts and transit ridership forecasts, to identify the factors that affect their accuracy, and to develop a method to estimate the uncertainty inherent in those forecasts. In addition, this research investigates the pre-pandemic decline in transit ridership across the US metro areas since 2012 and its influence on the accuracy of transit forecasts.

The sample of 1,291 road projects from the …

Evaluation Of Scoring Methods For Prioritizing Pedestrian And Bicycle Projects, Daria Korostina

Theses and Dissertations--Civil Engineering

To increase the number of pedestrian and bicycle facilities and to grow the number of people using those facilities in Kentucky more such projects need to be implemented. The Strategic Highway Investment Formula for Tomorrow (SHIFT) is a data-driven approach that Kentucky uses for prioritizing projects in the state, but its focus is auto-centric. The purpose of this study was to develop and evaluate a prioritization scoring approach for pedestrian and bicycle projects that could be implemented into SHIFT. The study used the SHIFT–2022 pedestrian and bicycle projects to develop and evaluate different scoring scenarios. After scoring each project on …

Identifying And Evaluating The Perceptions Of Near-Miss Reporting Within The Kentucky Transportation Cabinet, Seth Atkins

Theses and Dissertations--Civil Engineering

In the field of construction, most safety data and practices focus on preventing and mitigating serious incidents resulting in injuries or fatalities. However, on construction sites, near-miss events occur more frequently than said serious incidents and, under marginally different conditions, could potentially lead to damages, injuries, or fatalities. Therefore, near-miss reporting can serve as a useful tool for managing safety as it allows for workers to identify and managers to address potential risk factors within construction sites. While most construction companies have implemented some method for reporting near-miss events, many organizations, such as the Kentucky Transportation Cabinet (KYTC), struggle with …