Engineering Commons^™

Assessing Appropriate Technology Handwashing Stations In Mali, West Africa, Colleen Claire Naughton

USF Tampa Graduate Theses and Dissertations

Proper hand hygiene is the most effective and efficient method to prevent over 1.3 million deaths annually from diarrheal disease and Acute Respiratory Infections (ARIs). Hand hygiene is also indispensable in achieving the fourth Millennium Development Goal (MDG) to reduce the childhood mortality rate by 2/3rds between 1990 and 2015. Handwashing has been found in a systematic review of studies to reduce diarrhea by 47%#37; and is, thus, capable of preventing a million deaths (Curtis et. al., 2003). Despite this evidence, hand washing rates remain seriously low in the developing world (Scott et al., 2008).

This study developed and implemented …

Evaluating Cfrp-Masonry Bond Using Thermal Imaging, Joseph Christopher Ross

USF Tampa Graduate Theses and Dissertations

This study presents results from non-destructive testing to evaluate the degradation of the CFRP-masonry bond using thermal imaging. The goal of the research was to identify locations where there was evidence of bond deterioration that could subsequently be verified through destructive pull-off testing.

Four full-scale masonry walls were built outdoors at the University of South Florida in 1995 to evaluate the effectiveness of CFRP for repairing settlement damage. Two of the settlement-damaged walls were repaired using single layer, commercially available unidirectional CFRP systems that used Tonen (wall 3) and Henkel (wall 2) epoxies. These two walls were the subject of …

Kelvin Probe Electrode For Contactless Potential Measurement On Concrete-Properties And Applications, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

The practical feasibility of using a Kelvin Probe as a novel reference electrode in the measurement of both potential and polarization pulse response of reinforcing steel in concrete is demonstrated. Potential values measured using a KP reflect greater stability and repeatability than can typically be attained with conventional reference electrodes. Duplicate reinforced concrete beam test specimens with well-differentiated centrally corroding rebar segments were analyzed using both the Kelvin Probe (KP) and a conventional Saturated Calomel Electrode (SCE). Potential profile maps were developed using potential values recorded under static conditions with both the SCE and the KP. Nominal polarization resistance was …

Effect Of Localized Corrosion Of Steel On Chloride-Induced Concrete Cover Cracking In Reinforced Concrete Structures, Ezeddin Rafaa Busba

USF Tampa Graduate Theses and Dissertations

Abstract: Concrete cover cracking due to reinforcement corrosion is widely accepted as a limit-state indicator in defining the end of functional service life for existing reinforced concrete (RC) structures undergoing corrosion. Many of the currently available durability prediction models are incapable of providing realistic estimates of remaining service lives of RC structures beyond the corrosion initiation point. Therefore, the need to incorporate the length of the corrosion propagation stage in a comprehensive durability prediction approach has recently received much research attention. Previous research focus however was mostly limited to the case of uniformly corroding reinforcement with only few studies addressing …

Corrosion Of Post-Tensioning Strands In Ungrouted Ducts - Unstressed Condition, Michael John Hutchison

USF Tampa Graduate Theses and Dissertations

Recent failures and severe corrosion distress of post-tensioned (PT) bridges in Florida have revealed corrosion of the 7-wire strands in tendons. Post-tensioned duct assemblies are fitted with multiple 7-wire steel strands and ducts are subsequently filled with grout. During construction, the length of time from the moment in which the strands have been inserted into the ducts, until the ducts are grouted, is referred to as the `ungrouted' period. During this phase, the steel strands are vulnerable to corrosion and consequently the length of this period is restricted (typically to 7 days) by construction guidelines. This investigation focuses on determining …

Towards Rans Parameterization Of Vertical Mixing By Langmuir Turbulence In Shallow Coastal Shelves, Nityanand Sinha

USF Tampa Graduate Theses and Dissertations

Langmuir turbulence in the upper ocean is generated by the interaction between the wind-driven shear current and the Stokes drift velocity induced by surface gravity waves. In homogenous (neutrally stratified) shallow water, the largest scales of Langmuir turbulence are characterized by full-depth Langmuir circulation (LC). LC consists of parallel counter-rotating vortices aligned roughly in the direction of the wind. In shallow coastal shelves, LC has been observed engulfing the entire water column, interacting with the boundary layer and serving as an important mechanism for sediment re-suspension.

In this research, large-eddy simulations (LES) of Langmuir turbulence with full-depth LC in a …

Direct Shear Transfer Of Lightweight Aggregate Concretes With Non-Monolithic Interface Conditions, Dane Michael Shaw

Masters Theses

"This thesis describes the results of a study initiated to examine the influence of concrete unit weight on the direct shear transfer across an interface of concretes cast at different times. This type of interface is common with structural precast concrete connections, such as corbels, for which shear friction design provisions are commonly used. Increasing use of lightweight aggregate concretes prompted this investigation to determine the appropriateness of current shear friction design provisions with respect to all-lightweight and sand-lightweight concrete. The experimental investigation included thirty-six push-off test specimens, each of which was constructed with a cold-joint at the interface shear …

Library Holdings (2013) Ce Report, Georgia Southern University, Zach S. Henderson

Program Accreditation Reports (2013-2023)

This document is a part of the 2013 Library Holdings Report for the Zach S. Henderson Library at Georgia Southern University. The report includes data for the library resources and services supporting the research of the Allen E. Paulson College of Engineering and Computing, Department of Civil Engineering and Construction.

Shear And Fracture Behavior Of High Performance Concretes, Mahdi Arezoumandi

Doctoral Dissertations

"Concrete is the most widely used man-made material in the world. Like other materials, it has been improved over time. Nowadays, with continued development of science and technology, a new generation of concretes is produced and is termed high performance concretes. A review of previously published work indicates that very few studies (in some cases none) have addressed the structural behavior of full-scale, high performance concrete elements. This study investigated the shear and fracture behavior of two types of high performance concrete - high-volume fly ash concrete (HVFAC) and self-consolidating concrete (SCC). The HVFAC incorporates up to 70% cement replacement …

Numerical Analyses Of Long Carbon Fiber Reinforced Concrete Panels Exposed To Dynamic Loading, Zahra Sadat Tabatabaei

Doctoral Dissertations

"The purpose of this research was to evaluate impact and blast performance of long carbon fiber reinforced concrete experimentally and numerically. Experimental tests were conducted on plain concrete (PC), reinforced concrete, and four different types of long carbon fiber reinforced concrete (LCFRC). The results from each test were then compared to one another. This comparison indicates that adding long carbon fibers to concrete both increases the post-cracking behavior of concrete and decreases the spalls in either an impact or blast test. Among all of the fibers tested, Fiber Type B3 outperformed the other fibers, absorbing more energy during impact. Numerical …

A Method To Reduce Plastic Shrinkage Cracking Of Concrete Using Re-Vibration Technique, Mustafa Abushaala Aldalinsi

Open Access Theses & Dissertations

One of the problems that reduce durability; thus, performance of concrete is the development of plastic shrinkage cracking (PSC). Traditionally, the development of PSC has been minimized by controlling its exposure to weather conditions or by adding fibers. In this study, concrete re-vibration was used as an alternative technique to control PSC because of the limited availability of fibers in the developing countries. In this study, the wait time after slab casting and before vibration was selected to be 90 minutes while length of re-vibration time was varied from 15 to 45 seconds. Also, the water-cement ratios were selected to …

A Hybrid Modelling Approach For Maintenance And Rehabilitation Treatment Effectiveness Of Asphalt Pavements In Texas, Daniel Saenz

Open Access Theses & Dissertations

Analysis tools in pavement management systems are critical to assist transportation agencies in developing the most adequate maintenance and rehabilitation program. The significant elements are not only the type of treatment selected and its cost, but also the quantification of its short-term and long-term effectiveness and the timing of intervention. Methodologies with complex statistical approaches and performance model theories have been previously implemented in their derivation, but they may not be suitable or accurate. Therefore, it is imperative to factor in engineering experience in their assessment. In this thesis, a hybrid modelling approach was presented to systematically introduce expert knowledge …

A Systematic Approach To Manage Missing Data In Pavement Management Systems, Mazin M. Al-Zou'bi

Open Access Theses & Dissertations

Pavements are an important part of the highway transportation infrastructure, accounting for the largest share of the overall investment. A tremendous amount of time and money is spent each year on the construction of new pavements, as well as on the maintenance and rehabilitation of existing pavements.

Transportation agencies use pavement management systems (PMS) for their maintenance and rehabilitation planning, programming, and budgeting. PMS are used to make decisions regarding when maintenance and rehabilitation should be applied. The systems also select what type of treatment should be applied for each pavement section in the network with clear estimations of the …

Investigation Into The Operation And Safety Of Freeway Auxiliary Lanes: Towards Uniform Design Guidelines, Yubian Wang

Open Access Theses & Dissertations

Freeways operate closest to the purest form of uninterrupted traffic flow. There is no constant interruption to traffic flow (such as stop sign and traffic signal), and access is limited to ramp locations. Therefore, at freeways, bottlenecks, if exist, are usually caused by merging and diverging traffic at ramp locations. Bottleneck removal at freeway ramp areas can reduce average freeway commuter delay. Currently, engineers may add auxiliary lanes at ramp areas to mitigate or remove bottlenecks.

The American Association of State Highway Transportation Officials (AASHTO) publication A Policy on Geometric Design of Highways and Streets, commonly known as the "Green …

An Evaluation Of The Cerro Process As An Efficient Ro Concentrate Management System, Guillermo Guadalupe Delgado

Open Access Theses & Dissertations

The Concentrate Enhanced Recovery Reverse Osmosis (CERRO) Process is a new method to treat RO concentrate and brackish water with high concentrations of silica and calcium sulfate. Prior investigations have shown that the CERRO process can treat this kind of water without fouling or scaling the membranes, but the main factors that allow the system to operate in such conditions were not studied. The research presented here is an evaluation of the CERRO process as an efficient RO concentrate management system. The parameters of operation of the system were evaluated and improved. The precipitation of calcium sulfate was identified as …

Optimization Of Stress Wave-Based Nondestructive Methods In Identifying Deterioration In Concrete Structures, Hoda Azari

Open Access Theses & Dissertations

The transportation infrastructure across the United States is deteriorating and requires periodic inspection to predict the cost of repair and extent of maintenance activities, to remedy structural problems, and to ensure safety and serviceability. The use of nondestructive testing (NDT) methods in detecting and characterizing flaws in the infrastructure has become more common. Among different NDT methods, the stress wave-based methods, including ultrasonic surface waves (USW) and impact echo (IE) methods, are widely used to maintain concrete structures. In this dissertation, a complete literature review of seismic wave theory and wave propagation in plate like structures, and stress wave-based methods …

Attitude Towards Green Warehousing In El Paso, Texas: An Exploratory Analysis, Lynda Jeanette Macias

Open Access Theses & Dissertations

The increasing reliance on fossil fuels by today's emerging economies has a profound implication on the sustainability of many warehousing and distribution logistical systems worldwide. This research attempts to fill the gap in current green warehousing literature by investigating how warehousing and distribution facilities view greener strategies as a way to increase operation efficiency through a stated preference approach. A survey instrument was developed, and the survey was conducted to identify warehousing characteristics, green practices, and current green views of warehouse managers in El Paso, Texas. The survey results found a balanced outlook within the environment and business needs. Companies …

Adsorption Of Arsenic, Chromium, And Uranium From Saline Water On Clinoptilolite And The Treatment Of The Spent Regenerant By Duffusion Dialysis, Mutiu Olaitan Tanimola

Open Access Theses & Dissertations

Among various water purification and recycling technologies, adsorption is a fast, inexpensive and universal method. The development of low-cost adsorbents has led to the rapid growth of research interests in this field. The objective of this present study is the optimization of process parameters in adsorption of arsenic, chromium and uranium ions. The adsorption behavior of natural zeolite (clinoptilolite) has been studied in order to determine its applicability in treating water containing arsenic, chromium and uranium. The multiple adsorption of arsenic As (V), trivalent chromium Cr (III)] and uranium (VI) on natural zeolite (clinoptilolite) in single component and multiple component …

Analysis Of Vehicle Interactions On Interstate Highways: Discrete Choice And Linear System Approaches, Alicia Romo

Open Access Theses & Dissertations

The research in this dissertation developed statistical and linear system models to predict driving behavior according to driver attributes, vehicle characteristics, car-following dynamics and/or driving conditions. The scope of this research was limited to the interaction of two vehicles traveling in the same direction on interstate highways.

The statistical models proposed in this research investigated the contributions of the different vehicle types on the manner and likelihood of collision. Discrete choice models were used to estimate the probability of the types of collision (rear-end, angle and sideswipe) as functions of driver attributes, striking and struck vehicle types, pre-crash driving actions …

Recovering Magnesium Hydroxide And Sodium Chloride From Zero Discharge Desalination Concentrate Streams, Alemayehu Asfaw Yetayew

Open Access Theses & Dissertations

UTEP and Veolia Water Solutions & Technologies have been demonstrating and commercializing the Zero Discharge Desalination (ZDD) technology as part of a three year project sponsored by the U.S. Bureau of Reclamation. ZDD is able to achieve up to 98% recovery by desalinating brackish groundwater. ZDD is typically comprised of a reverse osmosis (RO) or nanofiltration (NF) system and a unique variation of electrodialysis called electrodialysis metathesis (EDM). The ZDD technology increases the yield of fresh water from water supplies that contain enough CaSO4 to cause precipitation problems when the water is treated with RO or NF alone. The EDM …

A Methodology To Consolidate Transit Stops For Enhancing Transit Users Travel Times, Mohammad Nurul Hassan

Theses

This study develops a methodology to consolidate transit stops. It develops a mathematical model and a program which takes stop consolidation decision(s) according to users travel time savings and desired accessibility. The model iterates until the users travels time savings are maximized. The study tests this mathematical model in different hypothetical scenarios. Six factors (distance between stops, passengers’ activity, average cruising speed, and maximum walkable distance, frequency of service and percentage of decreased passengers) with multiple levels were set to build the scenarios. Three responses (percentage of consolidated stops, percentage of travel time savings and percentage of operating …

Investigation Of The Mechanical Behavior Of I-Shaped Steel Beams Strengthened By Mechanically-Fastened Frp Laminates, Hothifa Nayef Rojob

Theses

Retrofitting and strengthening of steel structures have gained significant importance due to the highly increasing number of deteriorated steel structures in many places around the globe. The conventional method of retrofitting or strengthening of steel structures by replacing steel members or attaching additional external steel plates are usually time-consuming, corrodible, and a cumbersome task. Many of the drawbacks of the conventional retrofitting systems can be overcome through the use of Fiber Reinforced Polymers (FRP) due to their high strength-to-weight ratio. Furthermore, FRP materials are corrosion resistant, which makes them more durable especially when environmental deterioration is a concern. In recent …

Thermo-Elasto-Plastic Behavior Of Biaxially Loaded Steel Beam-Columns Inducing Those From World Trade Center Towers, Yanhong Zhao

Civil & Environmental Engineering Theses & Dissertations

An experimental and theoretical investigation into the behavior of biaxially loaded steel beam-columns is conducted including the effects of high temperature. Systems of materially nonlinear differential equations of beam-column equilibrium are first formulated for both ambient and high temperature conditions. An iterative finite integral procedure is formulated and programmed to solve the governing differential equations. To check the validity of the theoretically predicted behavior and strength of the beam-columns, a series of forty-two laboratory tests are conducted at both ambient and high temperature up to 950°F. Upon achieving a good agreement between the predicted beam-column behavior and that observed in …

Watershed-Scale Hybrid Stochastic-Deterministic Modeling Framework And Diffused Sources Superpositioning, Ruby Juvah Damalie

Civil & Environmental Engineering Theses & Dissertations

Predicting hydrologic system behavior is imperative to planning and management of water resources. The study developed an integrated hybrid stochastic and deterministic framework to improve prediction accuracy for overland flow and diffused sources in a watershed. The methodology includes sampling input parameters at system level and contribution of nonpoint source from hydrologically disconnected areas (heretofore referred to as system-level approach and superpositioning respectively). System-level approach includes the integration of a topography-based sampling grid generalized linear model developed by the study and Monte Carlo methods. The superpositioning method adopts in-stream water quality equation for overland flow pollution estimation.

The system-level approach …

Exploring Travel And Activity Behavior In Transit-Oriented Developments: Insights Into Transportation Benefits And Travel Demand Modelling, Sanghoon Son

Civil & Environmental Engineering Theses & Dissertations

As a sustainable urban development and transportation planning strategy, researchers and planners are increasingly interested in transit-oriented development (TOD). By integrating transit system and neighborhood design, TOD aims to provide a livable environment that is alternative mode friendly, higher density, and mixed-use to residents and workers in the vicinity of transit stations. Despite the recent growing interest in TOE), however, transportation benefits of TOD are not well quantified and characteristics of TOD are not adequately reflected in travel demand models.

This dissertation contributes to understanding of the travel and activity behavior by comprehensively exploring them in the context of TOD. …

An Evaluation Of Models Of Bare Soil Evaporation Formulated With Different Land Surface Boundary Conditions And Assumptions, Kathleen M. Smits, Viet V. Ngo, Abdullah Cihan, Toshihiro Sakaki, Tissa H. Illangasekare

Civil Engineering Faculty Publications - Archive

Bare soil evaporation is a key process for water exchange between the land and the atmosphere and an important component of the water balance. However, there is no agreement on the best modeling methodology to determine evaporation under different atmospheric boundary conditions. Also, there is a lack of directly measured soil evaporation data for model validation to compare these methods to establish the validity of their mathematical formulations. Thus, a need exists to systematically compare evaporation estimates using existing methods to experimental observations. The goal of this work is to test different conceptual and mathematical formulations that are used to …

Game Theory Approach To Transportation Network Vulnerability Measurement, Qixing Wang

Master's Theses

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

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

Master's Theses

No abstract provided.

Experimental Validation Of A Numerical Forward Model For Tunnel Detection Using Cross-Borehole Radar, Arvin Farid, Jose A. Martinez-Lorenzo, Akram N. Alshawabkeh, Carey M. Rappaport

Civil Engineering Faculty Publications and Presentations

The goal of this research is to develop an experimentally validated twodimensional (2D) finite difference frequency domain (FDFD) numerical forward model to study the potential of radar-based tunnel detection. Tunnel detection has become a subject of interest to the nation due to the use of tunnels by illegal immigrants, smugglers, prisoners, assailants, and terrorists. These concerns call for research to nondestructively detect, localize, and monitor tunnels. Nondestructive detection requires robust image reconstruction and inverse models, which in turn need robust forward models. Cross-Well Radar (CWR) modality is used for experimentation to avoid soil-air interface roughness. CWR is not a versatile …

Assessment Of Passive Fire Protection On Steel-Girder Bridges, Michael Davidson

Masters Theses & Specialist Projects

Bridges in the US are severely damaged or suffer collapse from fires at significant rates, even when compared to other hazards such as earthquakes. Fire-induced bridge collapses are perpetuated by the general lack of installed fire protection systems. Therefore, new materials and applications are needed to mitigate structural damage that can be caused to civil infrastructure by severe fires. Accordingly, the objective of this study is to further the development of new fire protection applications in transportation structures. Specifically, the investigation centers on the development of new applications in passive fire protection materials, within the context of shielding steel-girder bridges …