Civil Engineering Commons^™

Modeling The Extent Of Virus Removal In Waste Stabilization Ponds To Support Reuse Of Wastewater, Kelly James Vannoy

USF Tampa Graduate Theses and Dissertations

Waste stabilization ponds (WSPs) are one of the most prevalent types of domestic wastewater treatment technologies employed worldwide, and global stressors such as urbanization, population growth, climate change, and water scarcity have increased the demand for reusing treated wastewater. The safe reuse of treated wastewater in agriculture can ease water scarcity, aid in food production, and reduce environmental degradation from the discharge of wastewater effluent to surface waters. The ability to predict virus concentrations in wastewater effluent is an important criterion for determining whether wastewater is suitable for discharge to the environment or for reuse in agriculture. However, many uncertainties …

Full Scale Evaluation Of Organic Soil Mixing, Kelly Costello

USF Tampa Graduate Theses and Dissertations

Soil mixing is a procedure that has proven to be effective for loose or soft compressible soils. The method stabilizes the soil in-place using specialized augers, tillers, or paddles that inject grout or dry cementitious powders as part of the mixing process. The Federal Highway Administration design manual for soil mixing helps to estimate the required amount of cementitious binder to produce a target design strength. However, it is biased towards inorganic soils and only mentions caution when confronting organic soils which usually come with a high water table, moisture content and void volume.

The Swedish Deep Stabilization Research Centre …

Modeling Food Security, Energy, And Climate And Cultural Impacts Of A Process: The Case Study Of Shea Butter In Sub-Saharan Africa, Colleen Claire Naughton

USF Tampa Graduate Theses and Dissertations

Millions of people in the world, particularly women and people in sub-Saharan Africa, suffer from hunger and poverty. Three of the major 2015-2030 United Nation’s Sustainable Development Goals (SDGs) aim to eliminate hunger through food security and sustainable agriculture, eradicate poverty, and achieve gender equality through women’s empowerment. Shea trees and their associated fruit and butter can play a major role in each of these three SDGs for women and their families throughout sub-Saharan Africa. Shea trees are located over a wide expanse stretching more than 5,000 kilometers across over eighteen countries in sub-Saharan Africa. These trees produce fruit that …

Corrosion Of Steel In Submerged Concrete Structures, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

This investigation determined that severe corrosion of steel can occur in the submerged portions of reinforced concrete structures in marine environments. Field studies of decommissioned pilings from actual bridges revealed multiple instances of strong corrosion localization, showing appreciable local loss of steel cross-section. Quantitative understanding of the phenomenon and its causes was developed and articulated in the form of a predictive model. The predictive model output was consistent with both the corrosion rate estimates and the extent of corrosion localization observed in the field observations. The most likely explanation for the observed phenomena that emerged from the understanding and modeling …

Effect Of Mineral And Chemical Admixtures On Durability Of Cementitious Systems, Victor Tran

USF Tampa Graduate Theses and Dissertations

Mineral and chemical admixtures are used today in almost all concrete mixtures to improve concrete fresh and hardened properties, and to enhance concrete durability. In this study, four mineral and four chemical admixtures were investigated: namely, metakaolin (MK), silica fume (SF), Class F fly ash (FA), blast-furnace slag (BFS), two high-range water reducers (SP), water reducer/retarder (WRD), and air-entrainer (AEA). The objective of this study is to assess the effects of commonly used mineral and chemical admixtures on the durability of the cementitious system. Two durability issues were addressed in this study: the potential of the cementitious system to generate …

Evaluation Of Low-Cost Low Impact Development Practices In Southwest Florida For The Control Of Urban Runoff, Laura Kathren Rankin

USF Tampa Graduate Theses and Dissertations

Stormwater management is required due to development and alteration of the natural environment. It is heavily regulated in Florida and at the national level. Over the last two decades, Low Impact Development (LID) has been promoted as a sustainable and environmentally friendly method of controlling urban runoff. Case studies, provided in Chapter 2, show that LIDs can restore watershed hydrology by balancing the water budget. The difference in runoff between pre-development and post-development appears to increase with soil perviousness. However, the potential for mitigating the impacts of urbanization through runoff reduction is also greater for pervious, sandy soils that dominate …

Binding Of Nitrite In Concrete, Cement Mortar And Paste, Saad Alshehri

USF Tampa Graduate Theses and Dissertations

Calcium nitrite as a corrosion inhibitor is mainly used to protect steel reinforcement in concrete by reducing its corrosion rate. Hence the effectiveness of calcium nitrite depends on its availability as a free nitrite in the pore solution. The present research work aims to determine the concrete mixture component mostly responsible for nitrite binding in concrete. Firstly, the experimental program included testing of nitrite binding in cement paste. Secondly, the effect of adding the fine aggregate (mortar mix) on nitrite binding was assessed. Finally, the mix with coarse aggregate (concrete mix) was evaluated. In-situ leaching method was used to obtain …

Consumer Perception And Anticipated Adoption Of Autonomous Vehicle Technology: Results From Multi-Population Surveys, Nikhil Menon

USF Tampa Graduate Theses and Dissertations

Emerging automotive and transportation technologies, such as autonomous vehicles (AVs) have created revolutionary possibilities in the way we might travel in the future. Major car manufacturers and technology giants have demonstrated significant progress in advancing and testing AV technologies in real-life traffic conditions.

Results from multi-population surveys indicate that despite enjoying moderate familiarity with AVs, more than 40% of the respondents were likely to use them when they become available. Simply looking at the demographic differences without paying any regard to the perceptions might suggest that the demographic differences are the primary causal factors behind the differences observed in the …

Feasibility Of Cathodic Protection In Grouted Post Tensioned Tendons - Exploratory Model Calculations, Jacob Dharma Bumgardner

USF Tampa Graduate Theses and Dissertations

Recent corrosion related failures of grouted post tensioned tendons, even after the introduction of improved grouts, have led to renewed interest in supplemental or backup means of corrosion control for these systems. A finite element model is presented to explore feasibility of impressed current cathodic protection of strand in grouted tendons. The model examines polarization evolution as function of service time and includes consideration of anode placement and size, grout porosity, pore water alkalinity, electrochemical species diffusivity and applied voltage on the polarization efficacy and durability of such a system. The exploratory model projections suggested that, within the context of …

Kelvin Probe Electrode For Field Detection Of Corrosion Of Steel In Concrete, Leonidas Philip Emmenegger

USF Tampa Graduate Theses and Dissertations

While the Kelvin Probe (KP) has been used in a variety of surface scanning applications, the use of the KP in reinforced concrete structures to detect corrosion has been pioneered by previous work performed at the University of South Florida. However, in that work, the scale and construction of the probes was not suited to use in the field. This is primarily attributable to the small operating disk-to-concrete gap which would make the probe unable to accommodate road conditions, such as irregularities in the grading of the road, and local pitting of the surface. Therefore, it was important to investigate …

Prediction Of The Optimum Binder Content Of Open-Graded Friction Course Mixtures Using Digital Image Processing, Yolibeth Mejias De Pernia

USF Tampa Graduate Theses and Dissertations

Florida Department of Transportation (FDOT) has been using Open Graded Friction Course (OGFC) mixture to improve skid resistance of asphalt pavements under wet weather. The OGFC mixture design strongly depends on the Optimum Binder Content (OBC) which represents if the mixture has sufficient bonding between the aggregate and asphalt binder. At present, the FDOT designs OGFC mixtures using a pie plate visual draindown method (FM 5-588). In this method, the OBC is determined based on visual inspection of the asphalt binder draindown (ABD) configuration of three OGFC samples placed on pie plates with pre-determined trial asphalt binder contents (AC). The …

Hydrocompaction Considerations In Sinkhole Investigations, Edward D. Zisman P.E., P.G., Stephen West

Sinkhole Conference 2015

The cause of ground settlement is a significant concern in sinkhole investigations where the potential for shallow and deep-seated instability in the subsurface is a major focus of the investigation. Complicating the investigation is the occurrence of hydrocompaction of surficial soils caused by introduction of large amounts of surface water particularly from improper maintenance of rainfall runoff. This condition is usually followed by the subsequent loss of soil moisture during dry periods. This manuscript will discuss how hydrocompaction plays a role in the analysis of settlement in the investigation of sinkhole loss and how one can distinguish between hydrocompaction settlement …

Predicting Compaction Grout Quantities In Sinkhole Remediation, Edward D. Zisman P.E., P.G.

Sinkhole Conference 2015

Predicting the required quantity of grout needed to remediate a sinkhole-damaged home is a challenging task that involves significant amounts of uncertainty. The difficulty arises from the limited amount of subsurface information that is available to make subsurface predictions particularly in complex karst environments. In typical sinkhole investigations, our understanding of the subsurface is limited by the three to four data points (borings) that provide a small window into actual subsurface conditions. This information is normally obtained from borings and from information inferred by geophysical surveys. In many cases, the information is not sufficient to make accurate predictions of grout …

Monitoring The Threat Of Sinkhole Formation Under A Portion Of Us 18 In Cerro Gordo County, Iowa Using Tdr Measurements, Kevin O'Connor, Matthew Trainum

Sinkhole Conference 2015

Sinkhole formation is a common occurrence in northeast Iowa, and U.S. 18 in Cerro Gordo County was constructed over an area where sinkhole formation had only been locally known. It had not been recorded or identified in the Iowa DNR database at the time. Since 2004, sinkholes have developed along the right of way. Geophysical surveys contributed very little in the identifying the cause. However a Soil Survey (drilling program) identified numerous voids within carbonate bedrock. The soil borings indicated that shale overlying the carbonate rock has been removed/eroded, and resulted in the development of a karst subsurface through the …

Risk-Taking Characteristics As Explanatory Variables In Variations Of Fatality Rates In The Southeastern United States, Jodi Anne Godfrey

USF Tampa Graduate Theses and Dissertations

Traffic fatalities accounted for 1.24 million lives lost in 2013 worldwide, and almost 33 thousand of those fatalities were in the U.S. in 2013. The southeastern region of the nation stands out for continuously having higher fatality rates per mile driven than the national average. If one can establish compelling relationships between various factors and fatality rates, then policies and investments can be targeted to increase the safety on the network by focusing on policies that mitigate those factors. In this research effort risk-taking characteristics are explored. These factors have not been as comprehensively reviewed as conventional factors such as …

Solids Accumulation Rates Of Latrines At Rural Schools In Nimba County, Liberia, Caraline M. Murphy

USF Tampa Graduate Theses and Dissertations

Access to appropriate sanitation facilities as well as access to clean drinking water are considered fundamental human rights (Carr, 2001; Bjorklund & Sjodin, 2010), yet roughly 2.5 billion people on the planet lack access to an improved form of sanitation (WHO/UNICEF, 2014). Additionally, many entities responsible for emergency excreta management and sanitation management design guidelines, specifically solids accumulation rates in latrine pits, use rates that are 30-60 years old and may be established from dated knowledge on diet and lifestyle trends (Franceys et al., 1992; Harvey et al., 2002; Harvey, 2007). Using solids accumulation rates that are dated as well …

Laboratory Evaluation Of Organic Soil Mixing, Spencer Dean Baker

USF Tampa Graduate Theses and Dissertations

Organic soils present a difficult challenge for roadway designers and construction due to the high compressibility of the soil structure, the often associated high water table, and the high moisture content. For other soft or loose soils (inorganic soils), stabilization via cement or similar binders (a method called soil mixing) has proven to be an effective solution. To this end, the Federal Highway Administration has published a comprehensive design manual for these techniques. Organic soils, however, are not addressed therein to a level of confidence for design, as organic soils do not follow the trends of inorganic soils. This has …

Effect Of Dosage Of Non-Chloride Accelerator Versus Chloride Accelerator On The Cracking Potential Of Concrete Repair Slabs, Thomas F. Meagher

USF Tampa Graduate Theses and Dissertations

Due to strict placement time and strength constraints during the construction of concrete pavement repair slabs, accelerators must be incorporated into the mixture design. Since the most common accelerator, calcium chloride, promotes corrosion of concrete reinforcement, a calcium nitrate-based accelerator was studied as an alternative. To replicate mixtures used in the field, commercial accelerators commonly used in concrete pavement repair slabs were used in the current study. Crack risk of different mixtures was assessed using modeling and cracking frame testing. HIPERPAV modeling was conducted using several measured mixture properties; namely, concrete mechanical properties, strength-based and heat of hydration-based activation energies, …

Performance Evaluation And Integrated Management Of Airport Surface Operations, Qing Wang

USF Tampa Graduate Theses and Dissertations

The demand for aviation has been steadily growing over the past few decades and will keep increasing in the future. The anticipated growth of traffic demand will cause the current airspace system, one that is already burdened by heavy operations and inefficient usage, to become even more congested than its current state. Because busy airports in the United States (U.S.) are becoming "bottlenecks" of the National Airspace System (NAS), it is of great importance to discover the most efficient means of using existing facilities to improve airport operations.

This dissertation aims at designing an efficient airport surface operations management system …

Operation Optimization And Water Quality Simulation Of Potable Water Distribution System, Xiongfei Xie

USF Tampa Graduate Theses and Dissertations

A potable water distribution system (WDS) consists of pipes, pumps, valves, storage tanks, control and supporting components. Traditionally, it has two basic functions. First, provides end users with potable water at sufficient pressures and good water quality. Second, provides sufficient pressure and flow for fire fighting. Currently, potable water is still the least expensive material for fire fighting. To accomplish these two goals, water utilities have to consider the integrity and security of the water network. As a result, this research selected three research topics that are closely related to the daily operation of water utilities and water quality simulation. …

Improving Functionality And Sustainability Of Commercial Insulation: Experimental Study, Heat Transfer Modeling, Environmental Assessment, Celine Manoosingh

USF Tampa Graduate Theses and Dissertations

he Department of Energy names executing and integrating high-performance sustainable design and green building best practices a Strategic Sustainability Performance Plan goal under the Executive Order 13514 (U.S DOE, 2009). As sustainability becomes a primary

goal for engineers, a decision making framework is needed to guide their choice of materials and processes; and then to carry out the evaluation of their chosen design. Sustainable design process, and the products developed through its application, work concurrently with functionality and sustainability evaluation methodologies to cultivate a continuous loop of design, implementation, assessment and improvement. In this context, an alternative insulation prototype exploring …

Forecasting Corrosion Of Steel In Concrete Introducing Chloride Threshold Dependence On Steel Potential, Andrea Nathalie Sanchez

USF Tampa Graduate Theses and Dissertations

Corrosion initiates in reinforced concrete structures exposed to marine environments when the chloride ion concentration at the surface of an embedded steel reinforcing bar exceeds the chloride corrosion threshold (CT) value. The value of CT is generally assumed to have a conservative fixed value ranging from 0.2% to - 0.5 % of chloride ions by weight of cement. However, extensive experimental investigations confirmed that CT is not a fixed value and that the value of CT depends on many variables. Among those, the potential of passive steel embedded in concrete is a key influential factor on the value of CT …

Comparison Of Different Approaches To Estimating Budgets For Kuhn-Tucker Demand Systems: Applications For Individuals' Time-Use Analysis And Households' Vehicle Ownership And Utilization Analysis, Bertho Augustin

USF Tampa Graduate Theses and Dissertations

This thesis compares different approaches to estimating budgets for Kuhn-Tucker (KT) demand systems, more specifically for the multiple discrete-continuous extreme value (MDCEV) model. The approaches tested include: (1) The log-linear regression approach (2) The stochastic frontier regression approach, and (3) arbitrarily assumed budgets that are not necessarily modeled as a function of decision maker characteristics and choice-environment characteristics.

The log-linear regression approach has been used in the literature to model the observed total expenditure as way of estimating budgets for the MDCEV models. This approach allows the total expenditure to depend on the characteristics of the choice-maker and the choice …

Evaluation And Modeling Of Internal Water Storage Zone Performance In Denitrifying Bioretention Systems, Thomas Joseph Lynn

USF Tampa Graduate Theses and Dissertations

Nitrate (NO3) loadings from stormwater runoff promote eutrophication in surface waters. Low Impact Development (LID) is a type of best management practice aimed at restoring the hydrologic function of watersheds and removing contaminants before they are discharged into ground and surface waters. Also known as rain gardens, a bioretention system is a LID technology that is capable of increasing infliltration, reducing runoff rates and removing pollutants. They can be planted with visually appealing vegetation, which plays a role in nutrient uptake. A modified bioretention system incorporates a submerged internal water storage zone (IWSZ) that includes an electron donor to support …

Deriving Statewide Freight Truck Flows From Global Positioning System (Gps) Data, Akbar Bakhshi Zanjani

USF Tampa Graduate Theses and Dissertations

An accelerated growth in the volume of freight shipped on Florida's highways has led to a significant increase in truck traffic, influencing traffic operations, safety, and the state of repair of highway infrastructure. Traffic congestion in turn has impeded the speed and reliability of freight movement on the highway system. Appropriate planning and decision making processes are necessary to address these issues. However, a main challenge in establishing such processes is the lack of adequate data on statewide freight movements. As traditional data sources on freight movement are either inadequate or no longer available, new sources of data must be …

A Multi-Period Mixed Integer Linear Programming Model For Desalination And Electricity Co-Generation In Kuwait, Nael Abdulhameed Alqattan

USF Tampa Graduate Theses and Dissertations

Water is the root of life and the engine that drives agriculture, industry, economy and services. The demand for water often necessitates desalination, particularly in arid coastal environments where there are several desalination technologies in use today such as Multi-Effect Distillation (MED) and Reverse Osmosis (RO). The key utility requirement for technologies such as desalination and population in general include energy in one form or another. Therefore, desalination and co-generation are often integrated. Another key utility is electricity which is generated from either renewable or non-renewable sources. The demands for water and electricity change over time and are subject to …

Low-Cost Household Groundwater Supply Systems For Developing Communities, Michael Maccarthy

USF Tampa Graduate Theses and Dissertations

ABSTRACT

Self-supply is widely reported across various contexts, filling gaps left by other forms of water supply provision. This research assesses low-cost household groundwater supply technologies in markets in developing country contexts of sub-Saharan Africa and Latin America, with a focus on the potential for improving Self-supply technology implementation and markets in sub-Saharan Africa. Specifically, a mature and unsubsidized Self-supply market for Pitcher Pump systems (suction pumps fitted onto hand-driven boreholes) is studied in an urban context in Madagascar, EMAS low-cost water supply technologies are assessed in Bolivia, and a technical comparison is completed with manual EMAS Pumps and family …

Diffuse Nutrient Pollution From Residential Catchments, Melissa Rachelle Butcher

USF Tampa Graduate Theses and Dissertations

Nonpoint source nutrient pollution is diffuse pollution lacking discrete origin and conveyance. This thesis synthesizes and critically reviews research on residential nitrogen and phosphorus loss to stormwater runoff and leaching. The evaluation pulls from research covering influential socio-demographic indicators, such as use of lawn maintenance services and homeowner fertilizer practices. The extent to which such social and economic factors may influence the prevalence and fate of diffuse nutrients in stormwater runoff from residential areas has not been adequately established. Understanding the source and influencing factors of diffuse nutrient pollution is important in order to effectively protect surface and groundwater resources. …

Numerical Simulation Of Flow In Ozonation Process, Jie Zhang

USF Tampa Graduate Theses and Dissertations

In the last two decades, Computational Fluid Dynamics (CFD) has shown great potential as a powerful and cost-efficient tool to troubleshoot existing disinfection contactors and improve future designs for the water and wastewater treatment utilities.

In the first part of this dissertation two CFD simulation methodologies or strategies for computing turbulent flow are evaluated in terms of the predicted hydraulic performance of contactors. In the LES (large eddy simulation) methodology, the more energetic, larger scales of the turbulence are explicitly computed or resolved by the grid. In the less computationally intensive RANS (Reynolds-averaged Navier-Stokes) methodology, only the mean component of …

An Assessment Of The Emas Pump And Its Potential For Use In Household Water Systems In Uganda, Jacob Daniel Carpenter

USF Tampa Graduate Theses and Dissertations

Rural improved water supply coverage in Uganda has stagnated around 64% for a number of years and at this point more than 10 million rural people do not have access to an improved drinking water source. It has been recognized that progress toward improved water supply coverage and increased service levels may be gained through Government and nongovernmental organization (NGO) support of private investment in household and shared water supplies, commonly known as Self-supply. Self-supply can be promoted by introducing and building local capacity in appropriate and affordable water supply technologies such as hand-dug wells, manually drilled boreholes, low-cost pumps, …