Civil and Environmental Engineering Commons^™

Occupational Health And Job Satisfaction Assessment Of Bus Rapid Transit (Brt) Drivers, Alireza Samerei, Kayvan Aghabayk, Alireza Soltani

Journal of Public Transportation

Several studies have focused on ergonomics of commercial and urban bus drivers; however, there exists a dearth of research on BRT drivers. This study was conducted to investigate the factors affecting the BRT drivers' mental health and satisfaction. The study was carried out on 171 BRT drivers in Tehran, Iran. The required data were collected through two questionnaires. The Classification and Regression Tree (CART) and Hierarchical clustering (HC) was used to extract factors affecting mental health and satisfaction of BRT drivers. The important factors affecting BRT drivers' mental health were: dispute with passengers, depression, BMI, criminal behaviours of passengers, driver's …

Computational Fluid Dynamics (Cfd) Analysis Of The Hydraulic Performance And Bio-Kinetics In A Full-Scale Oxidation Ditch, Kiesha C. Pierre

USF Tampa Graduate Theses and Dissertations

An oxidation ditch is a biological wastewater treatment unit process where microorganisms are utilized to transform organic matter, and nitrogen from wastewater to meet the desirable effluent concentrations. Mechanical aerators are part of these biological reactors facilitating oxygen transfer for the aerobic microorganisms, while agitating and circulating the phase constituents within the ditch. Modeling the performance of an oxidation ditch involves combining hydrodynamics, oxygen mass transfer, and bio-kinetics and is one of the grand challenges that is of paramount importance in optimization of design and operations of these facilities in an energy efficient way while meeting the targeted effluent concentrations. …

Biochar Amended Bioretention Systems For Nutrient And Fecal Indicator Bacteria Removal From Urban And Agricultural Runoffs, Md Yeasir Arif Rahman

USF Tampa Graduate Theses and Dissertations

Excessive nitrogen and fecal indicator bacteria (FIB) in stormwater runoff from urban areas or dairy farm operations impair water bodies resulting algal blooms, gastrointestinal illness, and economic losses. Recent advancements in stormwater management, including low impact development (LID) techniques, have provided engineers with a variety of tools to use in place of traditional catch basins and retention ponds. One promising LID technology for runoff management is bioretention, which consists of a shallow depression containing engineered porous media and vegetation. Prior studies have shown that modified bioretention systems that include an internal water storage zone (IWSZ) to promote denitrification can improve …

Influence Of Coating Defects Within The Lock Seams On The Corrosion Performance Of Aluminized Steel Drainage Pipes, Mohammed Al Yaarubi

USF Tampa Graduate Theses and Dissertations

The electrochemical behavior of aluminized steel is investigated to determine the corrosion performance of coating deficiencies generated within the lock seams during the fabrication of aluminized steel corrugated pipe. Electrochemical techniques and visual and profilometric analysis are used to assess the ability of the aluminum and zinc coating to provide sufficient galvanic protection to the underlying steel in the presence of a crevice. Also, Crevice coupons and lock-seam samples were used in this investigation in different environmental conditions simulating natural water conditions to relate the corrosion rate with the level of protection that the coating will provide. In addition, a …

Development Of A Numerical Process Model For Adsorbent-Amended Constructed Wetlands, Lillian Mulligan

USF Tampa Graduate Theses and Dissertations

There is a need for alternative methods for municipal landfill leachate treatment as the high concentrations of pollutants in leachate interfere with processes at publicly owned treatment works (POTWs). Constructed wetlands (CWs) have been shown to be a sustainable alternative with good removal efficiencies for chemical oxygen demand (COD) and ammonia nitrogen (NH4+). The addition of an adsorbent media, such as zeolite and biochar, to CWs to further enhance removal efficiencies has been investigated in recent years. However, the long-term effects of zeolite and biochar addition to CWs is not well known. A model could be a useful tool to …

Corrosion Propagation Of Stainless Steel Reinforced Concrete, Nelly Sofía Orozco Martínez

USF Tampa Graduate Theses and Dissertations

Structural durability is a growing concern in global infrastructure. The infrastructure report card released by the American Society of Civil Engineers (ASCE) indicates that approximately 9.1% of the total bridges in the United States were structurally deficient in 2016. In addition, it suggests that about 40% of the total bridges in the country are now 50 years or older. This issue becomes even more critical in structures exposed to aggressive environments such as marine structures. Thus, federal and regional efforts are now being directed towards infrastructural durability improvement to improve the long-term cost-efficiency of civil infrastructure.

Corrosion prevention strategies may …

Corrosion Durability Service Life Of Calcium Silicate-Based Reinforced Concrete, Carolina Páez Jiménez

USF Tampa Graduate Theses and Dissertations

Corrosion of reinforcing steel is a major area of study for assessing durability of reinforced concrete infrastructure. Conventional concrete infrastructure designs use ordinary Portland cement (OPC) as the primary cementitious material. However, the world's current challenge to achieve sustainable development requires the cement industry to reduce its environmental impact, as it is responsible for 8% of the anthropogenic CO2 emissions. Hence, a new type of cement has been developed. This novel calcium silicate cement (CSC) reduces the carbon dioxide emissions during its manufacturing process as compared to OPC, providing an environmentally-sound alternative for reinforced concrete fabrication.

Corrosion of steel reinforcement …

Sustainability Assessment Of A Pressure Retarded Osmosis System, Samar Al Mashrafi

USF Tampa Graduate Theses and Dissertations

Desalination has the potential to provide a stable supply of clean fresh water and meet the increasing water demands; however, this process does come with a few challenges such as high energy consumption, high energy cost, and a discharge of a highly concentrated brine. Pressure retarded osmosis (PRO) is a technology that could work as an efficient energy recovery technology for desalination since it can significantly reduce the energy consumption and dilute the brine before discharge. Studies have assessed the economic feasibility of PRO systems; however, these studies have not addressed the environmental sustainability of the systems. Thus, there is …

Leaf Cutter Ant Nest Soil Cement Stabilized Earthen Bricks: Materials And Methods For Engineering Field Applications, Faith Malay

USF Tampa Graduate Theses and Dissertations

As climate change threatens vulnerable tropical climates and development outpaces resource availability, the need for diverse construction material grows. The United Nations Sustainable Development Goals aim to reduce poverty in all forms. Diversifying construction material works toward reducing indoor air pollution, the eradication of houselessness, encouraging diversification in industry, and supporting small scale industrialization. In the Province of Bocas del Toro in Panama, there is a tenuous connection to the greater industries in the country due to location and existing infrastructure.This research presents a literature review of the historical approaches to the construction and chemistry of cement stabilized earth bricks, …

Chorine Conversion: Biological And Water Quality Impact On Activated Carbon Block Point Of Use Filters, Horace S. Jakpa

USF Tampa Graduate Theses and Dissertations

Point-of-use (POU) activated carbon (AC) filters are ubiquitous in many U.S. households. AC can reduce concentrations of lead, other heavy metals, and mitigate taste and odor issues. However, AC filters also remove residual disinfectants, thus allowing for the proliferation of microbes in the filter. In chloraminated systems, this can lead to localized, filter-induced nitrification. Most notably, high nitrite and nitrate in drinking water can cause methemoglobinemia (blue baby syndrome) in children under the age of three, raising public health concerns.

As a control measure for nitrification within distribution systems, utilities practice periodic, short-term secondary disinfectant switches from chloramine to free …

Health Risk Assessment Of Local Populations Ingesting Water With Naturally Occurring Arsenic And Fecal Related Contaminants In Lake Atitlan, Guatemala, Marisol Alvarez

USF Tampa Graduate Theses and Dissertations

Lake Atitlan, Guatemala acts as a sink for wastewater discharge and as a source of drinking water. The populations living in the lake basin are primarily indigenous with a large percentage (70%) living in poverty. Wastewater effluent entering the lake poses an immediate health risk to those using it as a drinking-water source. Additionally, the lake is surrounded by three volcanoes and the water has concentrations of naturally occurring arsenic above the recommended reference level of 10 µg/L. Arsenic is acutely poisonous at high concentrations and has carcinogenic and neurological effects when chronically exposed at low concentrations.

The goal of …

Increasing Boarding Lost Time At Regular Bus Stops During Rainy Conditions: A Case Study, Margarita Novales, Alfonso Orro, José-Benito Pérez-López, Jorge Feal, Miguel R. Bugarín

Journal of Public Transportation

Inclement weather conditions affect the behavior of travelers and transportation system operations. Understanding this influence can help improve operational planning schemes for any mode of transport, especially for buses. One of the factors that can be affected by rainfall is the time expended by a passenger from the moment a bus opens its doors until he/she boards the bus. This time is known as the boarding lost time (BLT); it was first introduced in the last edition of the Transit Capacity and Quality of Service Manual (TCQSM). TCQSM only considers the BLT for bus rapid transit (BRT) stations with more …

Modeling Bus Bunching And Anti-Bunching Control Accounting For Signal Control And Passenger Swapping Behavior, Qi Xin, Rui Fu, Shaowei Yu, Satish V. Ukkusuri, Rui Jiang

Journal of Public Transportation

The conventional bus propagation process has two main shortcomings: one is bus bunching, the other is extra energy consumption by idling at signalized intersection and unexpected speed variation along the route. To overcome these problems simultaneously, an extended bus propagation model and an anti-bunching control are proposed. To extend the time-based bus propagation model, we employ finite state machine and intelligent driver model to establish a spatial-temporal based bus propagation model accounting for bus dynamic motion and passenger swapping behavior between bunching buses. To mitigate bus bunching and improve bus fuel economy in a cyber-traffic environment, an anticipated average speed …

Impact Of Grain Morphology On The Temporal Evolution Of Interfacial Area During Multi-Phase Flow In Porous Media, Fizza Zahid

USF Tampa Graduate Theses and Dissertations

Many environmental issues deal with the movement of immiscible fluids in the subsurface, e.g., cleanup of oil spills and geological carbon dioxide sequestration. Engineers face a constant challenge to improve the efficiency of these processes. This can be facilitated by studying the underlying physics of how fluids flow and interact in these systems.

Traditionally, lab experiments can provide reliable information about fluid architecture in porous medium, such as trapped fluid volumes and contact area between two immiscible fluids (interfacial area). However, these methods can be expensive and tedious. A well designed numerical experiment is not only able to describe fluid …

Corrosion Rate Prediction In Frp-Concrete Repair, Mohammad A. Khawaja

USF Tampa Graduate Theses and Dissertations

Research has proven that wrapping structural elements with fiber-reinforced polymers (FRPs) slows down chloride-induced corrosion rate but does not stop it. Although FRP has been used for corrosion repair for over 40 years, predictive corrosion rate models for FRP-concrete systems are limited in literature. This dissertation presents an oxygen diffusion-based predictive framework to estimate corrosion rate in FRP-concrete systems.

The dissertation has three main components. First, a core framework that is referred to as Khawaja-Sen-Bhethanabotla (KSB) model. In the KSB model, statistical methods were used to extend experimental data on oxygen permeation coefficients. These data were for one and two …

Assessment Of The Environmental Sustainability Of A Small Water Production Facility In Madagascar, Jesal Patel

USF Tampa Graduate Theses and Dissertations

Nearly 2.2 billion people around the globe struggle with access to safely managed drinking water (WHO/UNICEF, 2019), however, there have been certain initiatives taken, particularly by means of small water production facilities for enhancing access to basic drinking water services in rural areas. The water production facility, specifically located in the low- and middle-income countries, usually encounter operational difficulties as a result of limited availability of resources and are required to depend on other resourceful countries for goods and services. Although, with limited research done for assessing the environmental sustainability of water facilities in low- and middle-income countries, numerous data …

Understanding The Leaching Mechanism For Lead (Pb) Found In Components Of Locally Manufactured Handpumps In Eastern Madagascar, Nidhi Shah

USF Tampa Graduate Theses and Dissertations

This research sought to determine the lead leaching mechanism impacted by an inorganic scale observed from lead valve weights of the pitcher pump systems used in Tamatave, Madagascar. Based on previous research, these valve weights are considered to be a major source for high lead levels in pump water consumed by the residents. As a part of the study, Raman Spectroscopy, X-ray Fluorescence Spectroscopy (XRF) and Energy Dispersive Spectroscopy with Scanning Electron Microscope (SEM-EDS) were performed to address the objectives of this research. The pump component samples for the analysis were selected based on the amount and visual characteristics of …

Longitudinal Trajectory Tracking Analysis For Autonomous Electric Vehicles Based On Pid Control, Hossein Amiri

USF Tampa Graduate Theses and Dissertations

The implementation of autonomous vehicles has huge potential for revolutionizing transportation as we currently know it. All use cases of autonomous vehicles require the vehicle to travel on a pre-specified path. Accurate tracking of this defined trajectory is a crucial aspect of the implementation of autonomous vehicles; a controller system is required to translate this pre- defined trajectory in the form of the throttle, brake, and steering inputs. This project covers the application of a Proportional-Integral-Derivative (PID) controller to achieve longitudinal trajectory tracking of autonomous electric vehicles with stability and accuracy in the CARLA autonomous driving simulation platform. The implemented …

Passive Nitrifying Biofilters For Onsite Treatment Of Saline Domestic Wastewater, Daniel Arnulfo Delgado

USF Tampa Graduate Theses and Dissertations

The infrastructure to support the growing world population has polluted many water bodies with nitrogen from urban and agricultural runoff and failing wastewater systems, such as improperly sited and maintained septic systems. Septic systems present a low energy and maintenance option to treat domestic wastewater and is a treatment option that can be done far from a centralized grid. This further reduces cost, maintenance, and energy as it reduces the need to build and maintaining sewage piping and the infrastructure to move the water longer distances. However, these systems tend to fail when their upkeep is left to homeowners that …

Prediction Of The Effects Of Turbulence On Vehicle Hydroplaning Using A Numerical Model, Thathsarani Dilini Herath Herath Mudiyanselage

USF Tampa Graduate Theses and Dissertations

Pneumatic hydroplaning has been identified as one of the major causes of wet weathertraffic accidents. Therefore, knowledge of potential hydroplaning speeds is crucial in designing roadways to reduce crash risks. It has been shown that the tire inflation pressure is the predominant factor affecting the hydroplaning speed while factors such as the water film thickness also contribute heavily to this phenomenon. Extensive research has been directed at the development of accurate models to predict the effects of vehicle characteristics, pavement conditions and water film thickness on hydroplaning. Current literature does not indicate any studies directed at understanding the effects of …

Feasibility Of Epoxy Bond Enhancement On High-Strength Concrete, Amanda A. Lewis

USF Tampa Graduate Theses and Dissertations

While fiber-reinforced polymer materials have many applications in various industries,when used structurally, many cases, such as flexural and shear strengthening, are considered bond critical. Interfacial bond quality between a fiber-reinforced polymer system and the substrate is dependent on two mechanisms: chemical bonding and mechanical interlock, with mechanical interlock having the greater effect on bond quality. Mechanical interlock describes the type of bond that occurs as a result of surface roughness and substrate porosity and can be significantly affected by surface preparation methods and surface moisture. This study aims to explore the possibility of enhancing bond quality between carbon-fiberreinforced polymers and …

A Systems Approach For Improving The Performance Of Rural Community-Managed Water Systems Using Siasar: Case Studies In Bolivia And Colombia, Rachel A. Cannon

USF Tampa Graduate Theses and Dissertations

Globally, the focus of environmental engineers and water, sanitation, and hygiene (WASH) professionals in the rural water sector has shifted from building new technology to ensuring long-term functionality of water systems and closing the access gap between urban and rural residents. In Latin America and the Caribbean, the main challenges to ensuring clean water for all rural residents is poor service delivery quality and limited sustainability over time. A common management strategy in the region, and globally, is community-management, where community members manage, operate, and maintain the water system through cost sharing and financial management. The failure of community-managed water …

The Effect Of Cement And Blast Furnace Slag Characteristics On Expansion Of Heat-Cured Mortar Specimens, Jair G. Burgos

USF Tampa Graduate Theses and Dissertations

Delayed ettringite formation (DEF) is a durability issue that typically occurs in concrete exposed to high temperatures at an early age such as precast elements and massive concrete structural elements. There are many advantages to precast concrete such as its quality control, better safety control, and reusable forms, which make them cheaper than casting on site [1]. Heat curing of precast concrete is conducted to obtain high early-strength. However, in doing so, durability issues can arise in the form of internal sulfate attack also known as DEF, if the internal temperature of concrete exceeds 70°C. Past this threshold, ettringite decomposes …

Designing Next-Generation Transportation Systems With Emerging Vehicle Technologies, Zhiwei Chen

USF Tampa Graduate Theses and Dissertations

Recent advances in computing and artificial intelligence have enabled the development of various emerging vehicle technologies, e.g., autonomous vehicles (AV) and modular autonomous vehicles (MAV). These technologies bring new scientific and engineering problems challenging transportation researchers and practitioners. This dissertation aims to develop a suite of scalable computational and analytical tools for designing and analyzing next-generation transportation systems with the MAV technologies. Also, we intend to empirically study the system impacts in terms of the quality of service, energy implications, and inequality impacts.

For MAV system design, we develop a methodological framework centering at theoretical properties of the optimal system …

Coral Reef Restoration In The Tropical West Atlantic Amid The Covid-19 Pandemic, Linden Cheek

USF Tampa Graduate Theses and Dissertations

Climate change is increasing threats to coasts, both from storm surge and sea level rise. Healthy coral reefs provide reduction in storm surges, wave energy, coastal flooding and everyday erosion, and are found across a variety of spatial scales. Given the state of coral reefs worldwide, active Coral Reef Restoration (CRR) in emerging as a necessary component of coastal protection. CRR can be classified as a nature-based solutions (NbS) for coastal protection that also provides a multitude of ecosystem-based services to both humans and other life. Nearly all literature on coral restoration efforts assume a steady-state of human-ecological interactions, but …

A Framework For Assessing The Reliability, Availability, Maintainability, And Safety (Rams) Of Decentralized Sanitation, Adefunké Adeosun

USF Tampa Graduate Theses and Dissertations

In established industry sectors, Reliability, Availability, Maintainability, and Safety (RAMS) risk assessments are normally used to compare the risks associated with different technologies on process units. Sanitation solutions are split into traditional wastewater treatment which is centralized treatment and can be classified as an established industry, and decentralized treatment such as pit latrines and septic tank systems which are on much smaller scales. Also they can be classified as non-conventional methods such as reinvented advanced decentralized non-sewered sanitation solution techniques exist mainly in two forms as “Single-User Reinvented Toilet (SURT)” systems or “Multiple-User Reinvented Toilet (MURT)” systems. Advanced decentralized non-sewered …

Strength Restoration Of Corrosion Damaged Piles Repaired With Carbon Fiber Reinforced Polymer Systems, Jethro Clarke

USF Tampa Graduate Theses and Dissertations

Of the 12,741 bridges accounted for by the Florida Department of Transportation (FDOT), approximately 50% were built between the 1950s and 1960s. During this period, bridges were typically constructed in coastal environments using pile bents. Now, the main threat to bridges in these environments is corrosion, which occurs in the splash zones of most bridge piles. These zones contain high concentrations of chlorides, oxygen and moisture, the corner stones of a highly corrosive environment. Corrosion compromises steel reinforcement in these areas leading to cracking, spalling and an inevitable loss of capacity.

In recent years, significant strides have been made in …

An Inferential Study Of The Potential Consumer Value Of Free Charging For Users Of Public Electric Vehicle Charging Infrastructure, Divyamitra Mishra

USF Tampa Graduate Theses and Dissertations

Although there is economic and marketing evidence of consumers assigning additional benefits to free products and bundles, there is limited research into the behavioral consequences of offering public electric vehicle charging for free. Previous exploratory research by Maness and Lin analyzed possible economic and environmental benefits from offering free public charging infrastructure and policy. Their work found that providing free public charging infrastructure could increase plug-in electric vehicle sales and cause decreased reliance on fossil fuels in the personal transportation sector. However, their study assumed the increased value which consumers would place on free charge events. This project proposes to …

Black Lives Matter In Engineering, Too! An Environmental Justice Approach Towards Equitable Decision-Making For Stormwater Management In African American Communities, Maya Elizabeth Carrasquillo

USF Tampa Graduate Theses and Dissertations

The United States and the world have recently been challenged with the disparate effects of COVID-19 and the continual killings of unarmed Black men and women across the nation. A history of anti-black racism has led to systemic structures of inequity that thread throughout institutions and communities across the nation. This environmental engineering research comes at a time when understanding how to effectively engage in, and with Black communities is at the forefront of discourse in academia, utilities and private sector.

In 2018 the Brookings Institute published a report on workforce in the water sector demonstrating the lack of diversity …

Using A Systems Thinking Approach And Health Risk Assessment To Analyze The Food-Energy-Water System Nexus Of Seaweed Farming In Belize, Estenia J. Ortiz Carabantes

USF Tampa Graduate Theses and Dissertations

Certain macroalgae, commonly referred to as seaweed, have traditionally been used as a food source for many coastal communities around the world. In Belize, residents of the Placencia Peninsula cultivate two seaweed types, Eucheuma isiforme and Gracilaria spp. at Little Water Caye located 19 miles offshore. The dried seaweed is sold at the Placencia Producers Cooperative Society Limited (PPCSL) where community members process it into a variety of value-added products such as soaps, cosmetics, hair products, and food additives.

The overall goal of this research was to understand the existing food-energy-water system (FEWS) infrastructure landscape for seaweed production in Placencia, …