Civil and Environmental Engineering Commons^™

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 …

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 …

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 …

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 …

High-Solids Anaerobic Digestion Of The Organic Fraction Of Municipal Solid Waste State Of The Art, Outlook In Florida, And Enhancing Methane Yields From Lignocellulosic Wastes, Gregory Richard Hinds

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion (AD) is a biotechnology that employs natural microbial metabolism under oxygen-free conditions to stabilize organic waste. AD has been shown to be the most environmentally sustainable technology for treating the organic fraction of municipal solid waste (OFMSW), as it allows for the recovery of energy and nutrients from the waste. AD of OFMSW also saves landfill space and reduces leachate generation and fugitive methane emissions from landfills. High-solids AD (HS-AD) technologies (those designed to process feedstocks with >15% total solids content) have been shown to yield additional benefits when compared with liquid AD (L-AD) for treating OFMSW, including …

The Effect Of Urbanization On The Embodied Energy Of Drinking Water In Tampa, Florida, Mark Vincent Eli Santana

USF Tampa Graduate Theses and Dissertations

Increasing urbanization has serious implications for resource and energy use. One of these resources is drinking water. The increased amount of impervious surfaces associated with urban development is responsible for increased runoff during rain events, which may have a negative impact on the quality of nearby bodies of water, including drinking water sources. The growing populations associated with urbanization require a higher water demand. In addition, urban drinking water systems use energy to collect, treat, and distribute a safe reliable effluent to users. Therefore, this study focuses on the degree to which urbanization influences the embodied energy of drinking water …

Energy Production And Effluent Quality In Tubular Digesters Treating Livestock Waste In Rural Costa Rica, Maureen Njoki Kinyua

USF Tampa Graduate Theses and Dissertations

Use of tubular anaerobic digesters to treat livestock waste in developing countries has energy, agricultural, health, social and environmental benefits. However, careful use of digester effluent as a soil amendment is required due to the potential presence of protozoan parasites Cryptosporidium parvum and Giardia lamblia. This research investigated the performance of four tubular digesters in the Monteverde region of Costa Rica. High (>75%) volatile solids and BOD5 removal efficiencies were observed, which was attributed to the formation of a biologically active floccular sludge layer. Computational fluid dynamics (CFD) and bioprocess models were developed to evaluate the transport and transformation …

Environmental Sustainability Of Wastewater Treatment Plants Integrated With Resource Recovery: The Impact Of Context And Scale, Pablo K. Cornejo

USF Tampa Graduate Theses and Dissertations

There is an urgent need for wastewater treatment plants (WWTPs) to adapt to a rise in water and energy demands, prolonged periods of drought, climate variability, and resource scarcity. As population increases, minimizing the carbon and energy footprints of wastewater treatment, while properly managing nutrients is crucial to improving the sustainability WWTPs. Integrated resource recovery can mitigate the environmental impact of wastewater treatment systems; however, the mitigation potential depends on various factors such as treatment technology, resource recovery strategy, and system size.

Amidst these challenges, this research seeks to investigate the environmental sustainability of wastewater treatment plants (WWTPs) integrating resource …

Large-Eddy Simulation Of The Inner Continental Shelf Under The Combined Effects Of Surface Temperature Fluxes, Tidal Currents And Langmuir Circulation, Rachel Walker

USF Tampa Graduate Theses and Dissertations

In a shallow shelf region, turbulent motion can have a major effect on coastal processes including ecosystem functioning, surface gas exchange and sediment resuspension. Many factors contribute to such turbulence; wind and wave forcing, buoyancy induced by surface heat fluxes and tidal forcing all play a key role in generating vertical mixing in this shallow region. Alongside these independent sources of turbulence, combinations thereof can lead to full-depth turbulent structures acting secondary to the mean flow and leading to enhanced vertical mixing throughout the entire water column.

Field and laboratory experiments can often prove to be costly and time consuming, …

Mainstreaming Green Infrastructure: The Nexus Of Infrastructure And Education Using The Green Space Based Learning (Gsbl) Approach For Bioretention Plant Selection, Ryan Charles Robert Locicero

USF Tampa Graduate Theses and Dissertations

The Green Space Based Learning (GSBL) approach builds on a long-term partnership between a Research I university, surrounding community, and local school district, transforming underutilized community green space into an interactive educational tool to addresses national infrastructure and educational challenges. The GSBL approach is an educational platform for engaging K-12 and the local community in engineering design and construction of sustainable Green Infrastructure (GI) projects. GSBL was piloted as a part of a federally funded Research Experience for Teachers (RET) program in which teachers participated in two intensive 6-week summer research experiences and two consecutive academic year components. The summer …

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 …

Integrated Multi-Criteria Signal Timing Design For Sustainable Traffic Operations, Rui Guo

USF Tampa Graduate Theses and Dissertations

Traffic signal systems serve as one of the most powerful control tools in improving the efficiency of surface transportation travel. Traffic operations on arterial roads are particularly complex because of traffic interruptions caused by signalized intersections along the corridor. This dissertation research presents a systematic framework of integrated traffic control in an attempt to break down the complexities into several simpler sub-problems such as pattern recognition, environment-mobility relationships and multi-objective optimization for multi-criterial signal timing design.

The overall goal of this dissertation is to develop signal timing plans, including a day plan schedule, cycle length parameters, splits and offsets, which …

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 …

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, …

Evaluation Of School Vip Latrines And User Preferences And Motivations For Adopting Communal Sanitation Technologies In Zwedru, Liberia, Sarah J. Ness

USF Tampa Graduate Theses and Dissertations

This thesis has three objectives as follows: 1) to investigate VIP latrine design and establish if the communal school VIP latrines located on the shared campus of Tubman Wilson Institute (TWI) Junior and Senior High School and J.C. Barlee Elementary School were properly designed and constructed, 2) to explore the user preferences and motivations impacting the adoption of these school latrines, and 3) to develop a framework for factors that influence latrine adoption. These goals were formed by the author in response to her Peace Corps experience working at a high school in Zwedru, Liberia from August 2012 to August …

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 …

Effects Of Solids Retention Time And Feeding Frequency On Performance And Pathogen Fate In Semi-Continuous Mesophilic Anaerobic Digesters, Nathan Daniel Manser

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion is a biochemical process in which organic carbon is biodegraded in an oxygen free environment through a microbial consortium. Engineered biological systems used for resource recovery often utilize anaerobic digestion to treat anthropogenic organic wastes by reclaiming the carbon as energy (methane gas) and a soil amendment (biosolids). Small-scale, or household, semi-continuous anaerobic digesters have been used in developed and developing countries for many decades to produce biogas from human and livestock waste, which is used for heating, lighting, and cooking. This application has been shown to improve the quality of life of the user. Although there is …

Direct Membrane Filtration Of Domestic Wastewater: Implications For Coupling With Anaerobic Membrane Bioreactor (Df-Anmbr) For Wastewater Resource Recovery, George H. Dick

USF Tampa Graduate Theses and Dissertations

With the growing use of membranes in the water industry, different methods for using membranes to treat water is still occurring. Enhancing membrane performance is generally performed with extensive pretreatment methods before the feedwater is filtered by the membrane. With the utilization of direct membrane filtration (DF), no pretreatment is performed and the membrane is exposed to raw wastewater. While this may suggest that membrane performance and permeate quality would suffer in the process, DF testing with a 0.03 µm ultrafiltration PVDF membrane showed that relatively high membrane flux was sustained while producing a high quality effluent. Due to the …

Ecological Sanitation In Uganda: Promotion Through Demonstration Facilities And Potential For Ascaris Reduction By Free Ammonia Inactivation Using Stored Urine, John Thomas Trimmer

USF Tampa Graduate Theses and Dissertations

As Uganda works to transform itself into an industrialized, middle-income country in the coming decades, the country is faced with a number of problematic trends that could hinder this transition. High population growth and urbanization are quickly forcing small towns to deal with issues of limited space and the aesthetic conditions within sanitation systems, while declining soil fertility in surrounding rural areas calls into question the future nutritional security of the growing population. Ecological Sanitation (Eco-San) systems, which are designed to recover nutrients from human excreta, may help to address these trends.

Improved sanitation coverage in Uganda is currently estimated …

A Framework For Determining Building Water Cycle Resilience Using A Dynamic Water Resilience Assessment Model (Wram), Caryssa Joustra

USF Tampa Graduate Theses and Dissertations

The aim of this project was to quantitatively measure the resilience of the building water cycle. In order to accomplish this goal, a framework was developed that outlines how building water resilience can be evaluated. The framework presented assumed that resilience describes the fulfillment of system functions; in this case, the system functions considered are those actualized by the building water system. A building water resilience assessment model (WRAM) was developed with the ability to simulate different building water cycles and resilience scenarios. Resilience is dependent on the type and magnitude of a disturbance. Therefore, unique disruption scenarios were developed …

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 …

Development Of A Reusable Nutrient Recovery System To Sustainably Integrate Small-Scale Sanitation And Agriculture, Jorge Luis Calabria

USF Tampa Graduate Theses and Dissertations

Emerging technologies in sanitation and food production foster the potential to advance progress towards key sustainable development goals of ensuring adequate sanitation and food security to all. Non-Sewered Sanitation Systems (NSSSs), as detailed by the recent International Organization for Standardization’s (ISO) 30500 standard, are being developed to overcome challenges of lacking sanitation infrastructure and resource scarcity by providing autonomous, off-grid wastewater treatment (WWT) service in a much smaller footprints than large centralized treatment facilities. A promising NSSS platform is the anaerobic membrane bioreactor (AnMBR) that can achieve high (WWT) throughput in a small footprint using ultrafiltration (UF) membrane filtration to …

Residual-Based Variational Multiscale Les With Wall-Modeling For Oceanic Boundary Layers In Shallow Water, Roozbeh Golshan

USF Tampa Graduate Theses and Dissertations

Large-eddy simulation (LES) of wind and wave forced oceanic turbulent boundary layers is performed using the residual-based variational multiscale method (RBVMS) and near-wall modeling. Wind and surface gravity wave forcing generates Langmuir turbulence characterized by Langmuir circulation (LC) with largest scales consisting of streamwise vortices aligned in the direction of the wind, acting as a secondary flow structure to the primary wind-driven component of the flow. The LES here is representative of a shallow water continental shelf flow (10 to 30 meters in depth) far from lateral boundaries in which LC engulfs the full depth of the water column and …

A Passive Membrane Photobioreactor For The Isolated Cultivation Of Algal Resource Utilizing Selectivity (Icarus), With Wastewater As A Feedstock, Ivy Lea Cormier Drexler

USF Tampa Graduate Theses and Dissertations

Renewed momentum in the microalgae industry due to commercial interest in biofuels and bioproducts is driving the need to increase the economic competitiveness of large-scale microalgal production. Current knowledge of membrane systems common in other disciplines, such as environmental engineering, marine science, and biomedicine, are relevant to algae production. With pore sizes ranging from microns to angstroms, membranes provide tailored functions for solid/liquid separation (cell retention, biomass concentration and dewatering), gas/liquid separation (gas delivery and removal), and solute/liquid separation (bioproduct recovery, feedstock preparation and effluent recycling) that are problematic or not possible with other technologies. Though membranes have great potential …

Wastewater Nutrient Recovery Using Anaerobic Membrane Bioreactor Permeate For Hydroponic Fertigation, Jorge Luis Calabria

USF Tampa Graduate Theses and Dissertations

The imbalance between global population growth and resource consumption is indicative of unsustainable practices and foreshadows a grim future of continued resource depletion, food and water scarcity, social inequality, and deteriorating public and environmental health. Meanwhile, the urban centers of the world continue to experience exponential growth resulting in overwhelmed food, water, and sanitation infrastructure. Decentralized and satellite wastewater treatment technologies capable of resource recovery, such as anaerobic membrane bioreactors (AnMBR), foster synergistic opportunities to help manage the food, energy, and water sectors of urban environments. Specifically, the nutrient concentration and high effluent quality of permeate produced by AnMBR systems …

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. …

Effects Of Mix Design Using Chloride-Based Accelerator On Concrete Pavement Cracking Potential, Daniel Aaron Buidens

USF Tampa Graduate Theses and Dissertations

Cracked pavement slabs lead to uncomfortable and eventual unsafe driving conditions for motorists. Replacement of cracked pavement slabs can interrupt traffic flow in the form of lane closures. In Florida, the traffic demands are high and pavement repairs need to be carried out swiftly typically using concrete with high cement contents and accelerators to create rapid setting and strength gain. The concrete used in these pavement replacements is usually accompanied by a high temperature rise, making the replaced slabs susceptible to cracking. Cracking is a result of developed tensile stresses in the concrete, which exceed the concrete's tensile strength capacity. …

Opuntia Ficus-Indica Mucilage Potential To Remove Nuclear Active Contaminants From Water Based On A Surrogate Approach, Jose Adan Leon

USF Tampa Graduate Theses and Dissertations

Potable water is a necessity and unfortunately, it can be contaminated in many different ways. This paper specifically addresses the case scenario when, water has been contaminated by radionuclides. The mucilage of Opuntia ficus-indica (OFI), has been proven to be a great flocculating agent, turbidity reducer, crude oil dispersant and an environmentally friendly substance as an absorbent of water contaminants. In this work, the OFI mucilage was investigate to evaluate its capacity to separate radioactive ions from water. The surrogate approach is modeled based on water studies performed by Willi A. Brand, who proved that radioactive isotopes behave similar to …

Interpolating Beach Profile Data Using Linear And Non-Linear Functions, Lance Calloway Croft

USF Tampa Graduate Theses and Dissertations

ABSTRACT

Beach and nearshore surveys are conducted in a variety of ways, the most commonly used being the level-and-transit method; because it is inexpensive, time conducive and highly accurate. Specifically, beach surveys are conducted to better understand cross-shore, long-shore sediment transport processes, as well as to quantify volume changes, which are used to evaluate beach performance. In this study, a section of the beach on Sand Key, FL was surveyed using rod-and-transit. In addition to the commonly used linear data analysis, a non-linear analysis was conducted using NURBS (Non-Uniform Rational B-Splines).

Survey data was collected within a short time window …