ETD Search Results: instcode:osu

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138 matches in the database. These are records: 1 - 30.

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1. Ahn, Gi-Choul. The effect of urbanization on the hydrologic regime of the Big Darby Creek watershed, Ohio.

Degree: PhD, Civil Engineering, 2007, Ohio State University

► The Big Darby Creek Watershed located near the Columbus, Ohio, metropolitan area,… (more)

▼ The Big Darby Creek Watershed located near the Columbus, Ohio, metropolitan area, is widely recognized for its excellent quality of environmental health and high biological diversity in a Midwest agricultural landscape. The watershed has been affected by an increasing amount of runoff due to urban growth, causing occasional flooding, non-point pollution problems, and reduced biological diversity. This study focused on how urban growth in a once agricultural watershed impacted the surface hydrology. To accomplish this, an improved classification algorithm – the singular value decomposition (SVD) method with key vector analysis – for mapping land use/land cover (LULC) was developed. The process produced high accuracy LULC maps for the years of 1974, 1984, 1994, and 2005 with an overall accuracy of >89%. Also, an urban change matrix was introduced to better interpret urban change scenarios in this study. The urban change matrix showed that major urbanization in the Big Darby Creek Watershed occurred between 1994 and 2005. To investigate the hydrologic impact of the land use change in the Big Darby Creek Watershed, the improved LULC maps were used. The HEC-GeoHMS/HEC-HMS tools were used to develop a hydrologic model for the watershed in a distributed modeling scheme. The hydrologic simulation results showed that there is a significant increase (15%) in the peak hydrograph for Hellbranch Run, which is the most urbanized subwatershed in Big Darby Creek. When compared to the population forecast and recent reports on the Darby Creek development plan, the impact of the urban development will have a significant effect on the hydrology of the watershed. The sensitivity analysis of the LULC maps showed that the resulting hydrograph from the simulated LULC error would be minor for small urbanizing areas. In conclusion, an improved method for mapping LULC and its change in an urbanizing watershed was developed to investigate the impact of surface hydrology. The research resulted in a framework that can be used to study urbanizing watersheds. This framework can be used for future modeling efforts to understand the hydrological impact of LULC change in a watershed on a large scale. Advisors/Committee Members: Merry, Carolyn J.

Subjects: Engineering, Civil

Keywords: Urbanization, Big Darby Creek Watershed, LULC, hydrologic modeling, HEC-HMS

2. Al-Humaidi, Hanouf M. A fuzzy logic approach to model delays in construction projects.

Degree: PhD, Civil Engineering, 2007, Ohio State University

► Delays in construction projects are inevitable; as a result claims and disputes… (more)

▼ Delays in construction projects are inevitable; as a result claims and disputes arise among different construction parties. Different causes of delay can come into play, therefore, there is a need to identify and classify different causes of project delay. Estimation of the likelihood of delay resulting from different factors that contribute to project delay is essential to project success. Different factors that contribute to project delay affect the likelihood of project delay in different effectiveness degrees. There is a pressing need to estimate the likelihood of delay by implementing analysis methods and examining these methods. Probabilistic fault tree analysis and fuzzy fault tree analysis are two methods suggested by this research to estimate the likelihood of delay. Fuzzy fault tree analysis is performed by planners and managers since they select the delay causes that are applicable to a given project and categorize these delay causes into enabling, triggering, and procedural causes. Then, managers assess the degree of effectiveness of each cause of delay to overall project delay. Assessment of the contributing causes of delay and their degree of effectiveness on project delay uses subjective judgment linguistic terms. The result of the fuzzy fault tree analysis is a likelihood of delay membership function that is compared to the predefined fuzzy logic model to assess the degree of severity of the likelihood of delay. Likelihood of delay membership function is further quantified using the weighted average defuzzification method. Different fuzzy logic models are implemented into the fuzzy fault tree analysis, using Visual Basic software, these models are Baldwin’s rotational model, the Angular model, the Translational model and the Triangular model. Recommendation of the fuzzy logic model that is best applied to a given scenario needs further sensitivity analysis and is beyond the scope of this research. Validation of the fuzzy fault tree analysis computer model is performed. Some suggestions by experts are implemented into the computer model while other suggestions are deferred to future research. The computer software suggested by this study is an attempt to help reduce delays in construction projects that can cause time loss. Advisors/Committee Members: Tan, Fabian Hadipriono.

Subjects: Engineering, Civil

Keywords: Fuzzy Logic; Likelihood of Project Delay; Fuzzy Fault Tree Analysis; Fuzzy Logic Models; Translational Fuzzy Logic Model; Rotational Fuzzy Logic Model; Triangular Fuzzy Logic Model; Angular Fuzzy Logic Model; Delays in Projects

3. Ali, Tarig Abdelgayoum. New methods for positional quality assessment and change analysis of shoreline features.

Degree: PhD, Civil Engineering, 2003, Ohio State University

► In this dissertation, four positional quality measures for linear features presented by… (more)

▼ In this dissertation, four positional quality measures for linear features presented by Ramirez (2000) were thoroughly investigated on shoreline features including Generalization Factor, Distortion Factor, Bias Factor, and Fuzziness Factor. The investigation addresses the uniquness of each one of the four measures and the effect of random errors, systematic errors and blunders in the shoreline on the four measures. The results show that these four measures describe different characteristics of a shoreline. Also a new shoreline change modeling method was developed in this study based on a new concept known as shoreline-segment orientation. This method helps to better analyze shoreline-change at the segment level by studying the angular deviation from the surrounding segments and also from the whole shoreline. Shoreline segment orientation is critical in shoreline erosion analysis because it considers the direction of the incoming waves towards the shoreline. The results of analyzing shoreline change in the study area based on this concept of segment orientation have been found to correlate to the recorded change in the period of study. Using shoreline segment as a modeling unit, a new shoreline change forecast model was developed to analyze changes and furthermore to predict future shoreline positions. This model has the advantage of capturing the physical movement of a given shoreline segment through time by two indices. These indices represent the effects of scale-and-rotation and translation that have occurred to shoreline at a previous time causing the change. These indices are assumed to encapsulate the effects of the coastal erosion processes in the study area including shoreline shape, water-level change, shoreline geology or soil types, and erosion structures. The model uses the recorded change in the period of study to capture the pattern of shoreline-change at the segment level. Furthermore, the incorporation of shoreline positional quality information in the shoreline-change model has been addressed in this study. The significance of the models developed in this research is demonstrated by the quality of the results obtained in the case study. Also this study showed the need for future research on the Bias factor for positional quality assessment, and further investigation to expand the linear quality metrics for assessing the positional quality of other types of linear features. Advisors/Committee Members: Li, Rongxing.

Keywords: GEOGRAPHIC INFORMATION SYSTEMS; POSITIONAL QUALITY ASSESSMENT; SHORELINE FEATURES

4. Al-Kaabi, Noura Salem. A fuzzy-based construction safety advisor (CSA) for construction safety in the United Arab.

Degree: PhD, Civil Engineering, 2006, Ohio State University

► Construction safety is a concern for many researchers and people in the… (more)

▼ Construction safety is a concern for many researchers and people in the construction industry. The field of safety has been a topic of research, development and improvement for many decades, but little has been done in studying and improving construction safety in countries like The United Arab Emirates (UAE). The UAE has one of the fastest growing economies in the Middle East, where construction constitutes a major percentage of the gross domestic product. The government and regulatory agencies of UAE are working hard to regulate the industry and improve construction safety, but a more specialized study is needed. This research focuses on creating an automated tool, a construction safety advisor (CSA), that has the capability of assisting UAE construction contractor in improving their construction safety, and the UAE government agencies in establishing a basis for comprehensive construction safety codes. CSA has two main modules, each of which represents a model for improving construction safety. The first module evaluates the performance of a construction firm safety program using a program from OSHA and HSE. The module uses fuzzy logic to define two variables, significance and availability, for each unit of the safety program and evaluates the total safety program performance using two fuzzy membership forms. The second module evaluates the construction site safety setting using the ecological approach of environmental psychology. This module performs fault tree analysis to derive the basic events that contribute to the undesired construction site safety setting. The module is designed with default probabilities values that have been assigned for approximation based on literature reviews and subjective judgment. CSA also provides users with a number of resources including CSA help file, glossary of technical terms, links to construction safety resources on the web, and printable checklists for different units of the safety program, which could be used for onsite inspections. CSA was evaluated by safety engineers and construction managers in the USA whom rated it as very good. CSA can be used by construction firms wishing to evaluate their basic safety requirements before or during construction and to perform an onsite inspection using CSA printable checklists. Advisors/Committee Members: Hadipriono, Fabian C.

Subjects: Engineering, Civil

Keywords: Construction Safety, Safety Performance, Fuzzy Logic, United Arab Emirates

5. Al-Kaabi, Noura Salem. Improving safety performance in construction site operations in the United Arab Emirates.

Degree: MS, Civil Engineering, 2001, Ohio State University

► Construction related work is one of the world's most dangerous occupations making… (more)

▼ Construction related work is one of the world's most dangerous occupations making construction safety of paramount importance. This is particularly true in countries that have rapidly growing economies. These countries are engaged in a large number of construction projects where frequently construction workers are foreign national who do not speak the language of the country where they are working. Although many researchers have investigated the field of construction safety, few have focused on these special problems. The United Arab Emirates (UAE) is considered one of the fastest growing and most developed countries in the Middle East. Despite this fact, construction safety has not been seriously considered, and construction workers are threatened by possibility that a serious or fatal accident may occur while performing their job. Construction companies in the UAE value saving human lives and want to control the rising costs of accidents and reduce project delays due to accidents, but they don't know where to start. This study has the objective of assessing construction safety in the UAE and serves a first step in initiating a comprehensive safety program. This study is an overall evaluation of the UAE construction safety performance based on both a literature review and survey of construction company safety performance and attitudes. The literature review covers previous studies about safety in the UAE construction industry, the nature of the construction industry, as well as case studies of construction site accidents. An evaluation of the United Arab Emirates Federal Law No.8 (labor law) is also included in the review so as to establish a basis for judging the quality of safety regulations and codes in construction industry. The survey of construction contractors in the UAE is used to gather information not available in the literature on individual company performance. Despite the fact that the United Arab Emirates is a highly developed country, it lacks regulations and codes necessary for construction operation safety. The findings of this study, suggest that significant reforms are needed to establish either a new organization that will serve as an authority to guard and monitor safety in construction as well as other industries in the UAE, or alternatively, develop the current system into a more comprehensive one that will guard and regulate safety and health for all the industries in the UAE and especially the construction industry. Advisors/Committee Members: Hadipriono, Fabian.

6. Al-Khalidi, Aous Nahad. Evaluating Quality of Ziggurat of Ur Using Fuzzy Logic Concept and Fuzzy Logic Models.

Degree: MS, Civil Engineering, 2009, Ohio State University

► During the ancient civilizations many methods and techniques were used to build… (more)

▼ During the ancient civilizations many methods and techniques were used to build and construct structures, roads, bridges and buildings. Most of these methods and techniques are similar to what is being used nowadays. The significance of these methods and techniques is evaluated and estimated using linguistic expression specifically when dealing with ambiguous condition. These linguistic expressions are usually imprecise, and unclearly defined, yet extraordinarily useful. Using these imprecise expressions will make it difficult to apply mathematical calculations in order to conclude a crisp result with regard to project condition and structure quality. To avoid such difficulty, it is therefore essential to find a solution; that is the use of the concept of fuzzy logic and fuzzy set models. In using the fuzzy set models, it is applicable to manipulate certain expressions and transform them to numerical values on which mathematical calculations can be applied to acquire the consequences of variables and overall conclusion. This thesis presents and discusses three different fuzzy models: 1) The Angular Model, 2) The Translational Model, and 3) Triangular Model. The three models discussed are illustrated using C-Sharp programming language for user-friendliness. Each of the developed models has its own unique calculation process and has its encompassed advantages. The reason behind illustrating three different models is to allow for preference and selection of different users so they can compare between the features of each model and make their own decision in using the model of their choice. These models are used to evaluate the overall quality of the ziggurat and to estimate the integrity of the of the construction process of the ziggurat. Furthermore, the thesis presents an illustration of an intelligent system. An intelligent system program is illustrated to find the quality of the Ziggurat of Ur (Zigg-Ex) via evaluating the reliability of two factors that affect the structure directly. This computer program suggested by the study can be used as an attempt to help evaluate the overall quality of the Ziggurat of Ur. Advisors/Committee Members: Tan, Fabian.

Subjects: Civil engineering

7. Alsado, M. Hisham. Analytical versus measured reaction components of multi-stringer skewed steel bridges.

Degree: MS, Civil Engineering, 1988, Ohio State University

Advisors/Committee Members: Bishara, Alfred G.

8. Amaya, Peter. Progressive Damage and Failure Model for Composite Laminates under Multiaxial Loading Conditions.

Degree: MS, Civil Engineering, 2012, Ohio State University

► A progressive damage and failure model is proposed for continuous fiber reinforced… (more)

▼ A progressive damage and failure model is proposed for continuous fiber reinforced composite laminates under triaxial loading conditions. A literature review with emphasis on macromechanics based failure theories applied to composite laminates under static loading conditions shows that there is a need to validate failure models for composite laminates under triaxial loading conditions. Available experimental data show that the mechanical behavior and progressive damage of composite laminates may be different under multiaxial loading than under uniaxial loading conditions. The proposed failure model is an extension of the strain energy failure theory for triaxial loading conditions. The proposed strain energy model requires six parameters in order to predict the mechanical behavior and progressive damage of a composite laminate. Three material parameters are determined through laboratory tests involving unidirectional laminates subjected to multiaxial loading or multidirectional laminates subjected to uniaxial loading. The remaining three model parameters are used to represent unloading of failed lamina after initial failure has occurred. The proposed strain energy based failure theory and post initial-failure degradation model are combined with a stress field developed using either classical lamination theory or the finite element method using reduced integration quadratic hexahedral elements. The proposed failure model with classical lamination theory stress field gave adequate predictions compared with published experimental results for the initial failure, progressive damage, and final failure for tubular specimens under combined torsion and hydrostatic pressure as well as cylindrical dogbone specimens under combined uniaxial loading and hydrostatic pressure. The proposed failure model with the finite element stress field was able to adequately model stress concentrations near the free edges as well as predict initial, intermediate, and final failures for a cross-ply coupon under uniaxial extension as compared with experimental data. The validation of the proposed model suggests that it may be extended to predict the progressive damage and failure of composite laminate structures of complex geometries under complex loading conditions. Advisors/Committee Members: Butalia, Tarunjit.

9. Atves, Colleen E. A Fuzzy Logic Analysis of Sustainable Concrete Pile Foundations.

Degree: MS, Civil Engineering, 2010, Ohio State University

► Building foundations are commonly overlooked when it comes to sustainable construction practices.… (more)

Subjects: Civil engineering

10. Beal, Philip Edward. Estimation of the shear strengths of root reinforced soils.

Degree: MS, Civil Engineering, 1987, Ohio State University

Advisors/Committee Members: Wu, Tien H.

Keywords: SHEAR; SOILS; ROOT; SHEAR STRENGTHS; Shear Face; Shear Tests

11. Bob, Mustafa M. Enhanced Removal of Natural Organic Matter During Lime-Soda Softening.

Degree: PhD, Civil Engineering, 2003, Ohio State University

► In this research, a number of new approaches to increase the removal… (more)

▼ In this research, a number of new approaches to increase the removal of NOM during the lime-soda softening process were investigated. Specifically, softening sludge recycling in the presence and absence of cationic polyelectrolytes, MgCl2 addition in the presence and absence of softening sludge, and the role of high magnesium lime were all evaluated. Recycling of softening sludge during lime softening was found to effectively improve NOM removal. A 554 mg/L sludge dose added with the stoichiometric lime-soda ash dose removed 28% of NOM present in a raw water as compared to only 10% NOM removal in the absence of sludge. In addition, Hydrophobic/Hydrophilic fractionation analyses, together with SUVA measurements indicated that hydrophobic fractions of NOM were preferentially removed. Further experiments showed that sludge recycling did not significantly affect pH, turbidity, hardness and level of inorganic elements in treated waters. The presence of polyelectrolyte CPAM was found to increase the sorption capacity of calcite particles for Aldrich humic acid by three times. Based on this, softening sludge was coated with CPAM and recycled during jar tests. Results showed that sludge coated with low doses of CPAM can improve NOM removal to level significantly higher than regular softening. However, the NOM removal level was comparable to that achieved by recycling bare softening sludge. The use of high magnesium hydrated lime and the addition of magnesium were found to be promising techniques to increase Mg(OH)2 precipitation and consequently NOM removal during the softening process. DOC removal increased as available magnesium in hydrated lime increased. A dolomitic quick lime sample, slaked at ambient pressure, however, hindered NOM removal due to lack of available magnesium and subsequent coprecipitation. As high as 43% NOM removal was achieved in the presence of 0.312 mM MgCl2 and 457 mg/L softening sludge dose as compared to only 13% for regular softening. DBP precursors were removed as indicated by THM concentration measurements. All the techniques discussed here can be implemented without any modifications in existing facilities or addition of new treatment step and/or equipments. Advisors/Committee Members: Walker, Harold W.

Keywords: NOM; DBP; Sludge Recycle; Lime Softening; Hardness; Cationic Polymers; Inorganic Elements

12. Bova, Anthony Scott. Modeling the Ventilation of Natural Animal Shelters in Wildland Fires.

Degree: MS, Civil Engineering, 2010, Ohio State University

► The level of protection from wildland fires that tree cavities provide to… (more)

▼ The level of protection from wildland fires that tree cavities provide to sheltered fauna is not well understood. Further, few experiments have been performed to investigate the transfer of combustion products into, and ventilation of, tree cavity shelters in wildland fires. This paucity of data is unlikely to change in the near future. However, increasingly realistic fluid and fire dynamics simulation software has made the execution of “virtual experiments” tenable. In such experiments, data from simulations are used to form empirical relationships between the investigated phenomena and simulated conditions. As an example of this approach, the National Institute of Standards and Technology’s (NIST) Fire Dynamics Simulator (FDS) was used to create formulas for estimating maximum combustion product concentrations, doses (concentration integrated over time) and maximum gas temperatures within a single-entrance cylindrical shelter at heights above 3 m. A three-step approach was taken: First, FDS was validated for single-entrance ventilation by comparison of simulation results to data from large- and small-scale ventilation experiments. Second, data from 45 simulations of a single-entrance, cylindrical shelter subjected to frontal winds at various speeds, angles of incidence and temperatures, were used to create empirical formulas relating these variables to entrance flux and rates of temperature change. Third, these formulas were applied to data from 26 separate simulations of different surface fire scenarios. As a result, a single empirical formula was found relating gas concentrations, doses and maximum temperatures inside a shelter to fire intensity, flame depth and wind speed. The findings suggest that virtual experiments can help provide tools for forest and land managers to estimate the impact and minimize the hazards of prescribed burning, as well as evaluate the consequences of naturally occurring wildland fires. Advisors/Committee Members: Bohrer, Gil.

Subjects: Environmental engineering; Environmental science; Fluid dynamics

Keywords: wildland fire; animal shelter; cavity ventilation; fire dynamics simulator

13. Chen, Cheng. Study of Indicators of Recurrent Congestion on Urban Roadway Network Based on Bus Probes.

Degree: MS, Civil Engineering, 2010, Ohio State University

► Congestion has long been a concern to transportation operation and planning. Various… (more)

▼ Congestion has long been a concern to transportation operation and planning. Various methods and technologies have been developed and applied in detecting congestion. This study focuses on using bus as probes to indicate recurrent congestion on urban roadway networks. In this study, bus speeds are used to reflect indications of congestion. Bus speed data collected over “homogeneous days” are pooled in order to find indications of recurrent congestion. Bus speeds collected during a time period at each location are compared to bus speeds collected during other time periods (or during the whole day) at the same location. For practical purposes, the entire bus route investigated for the purpose of method development, validation, and demonstration is discretized into 10 meter spatial sections, and time of day is discretized into 30 minute time intervals. Each 10 meter long spatial section and 30 minute duration time interval constitutes a space-time cell for which existence or absence of an indication of congestion is determined. Three different methods are used to determine the existence or absence of an indication of congestion for each space-time cell. Two of the three methods, the Mean Based method and the Median Based method, apply traditional statistical tests. The other method, the Low Speed Threshold (LST) method, is developed in this study. An empirical study based on Automatic Vehicle Location (AVL) data collected using The Ohio State University (OSU) Campus Transit Lab (CTL) is conducted to evaluate the three methods. The indications of congestion produced by the three methods are then compared to a priori expectation of recurrent congestions along the route. The Mean Based method produces few indications of recurrent congestion. It misses space-time cells where recurrent congestion is expected. The Median Based method and the LST method produce similar general patterns in terms of where and when recurrent congestions are indicated. However, there exist some differences between the Median Based method and the LST method in terms of the specific locations where and specific times when recurrent congestions are indicated. A systematic analysis and comparison based on the Median Based method and the LST method is conducted. Based on the empirical analyses and a priori expectation of recurrent congestions along the route, the LST method seems more appealing than the Median Based method (and the Mean Based method) for determining indications of recurrent congestion. Although the empirical results produced by the LST method are encouraging, more research is necessary before concluding that the LST method could be used to detect recurrent congestion on a widespread basis. A sensitivity analysis of the parameters used in this study is suggested for future research. Other traffic related elements such as speed limits, bus trip running times, and schedule adherence might also be utilized to improve the recurrent congestion detection methods. Advisors/Committee Members: McCord, Mark R.

Subjects: Transportation

Keywords: recurrent congestion; bus probes; urban street

14. Chen, Dong. Ultrasonic Control of Ceramic Membrane Fouling Caused by Silica Particles and Dissolved Organic Matter.

Degree: PhD, Civil Engineering, 2005, Ohio State University

► This study systematically investigated the mechanism and efficiency of the ultrasonic control… (more)

▼ This study systematically investigated the mechanism and efficiency of the ultrasonic control of gamma-alumina ceramic membrane fouling caused by silica particles and dissolved organic matter (DOM). Ultrasound at 20 kHz was applied to a cross-flow filtration system. First, ultrasonic cleaning was explored with filtration of silica particles to investigate influence of both particle characteristics and ultrasonic factors on cleaning. Experimental results indicated that more effective control of fouling occurring at low particle concentrations, hydrophilic particles, and large particle sizes based on measurements of sound wave intensity, images of the cavitation region, and force balance analysis of a particle deposited on the membrane. In addition to the effect of particle characteristics, ultrasonic factors affecting membrane cleaning were explored. Optimal cleaning occurred when the membrane was outside but close to the cavitation region. However, damage in the form of pits and cracks were found when the membrane was within the cavitation region. An increase in the filtration pressure resulted in less improvement in permeate flux of ultrasound. Furthermore, pulsed ultrasound with short pulse intervals resulted in a relative permeate flux improvement close to that of continuous sonication. Second, besides sonophysical cleaning of particle fouled membranes, membrane cleaning was also explored by studying sonochemical reactions of DOM. Property changes of Aldrich and Pahokee peat DOM at different ultrasonic frequencies and energy densities were systematically investigated. Exposure of DOM to ultrasound resulted in decreases in hydrophobicity, aromaticity, and molecular weight, while DOM acidity increased. However, at low ultrasonic frequency (20 kHz) and low energy density, sonochemical transformation of DOM was insignificant. Finally, the effect of solution chemistry on ultrasonic control of membrane fouling caused by DOM and silica particles was examined. Experimental results indicated that more effective control of membrane fouling occurred at high pH, low ionic strength, and in the absence of divalent cations, due to stronger electrostatic repulsion among DOM macromolecules, silica particles, and the membrane. The decrease of the DOM rejection rate by ultrasound may be explained by the decreased steric exclusion effect, because ultrasound partially released membrane pore blocking and/or partially removed the foulant layer from the membrane surface. Advisors/Committee Members: Weavers, Linda K.

Subjects: Engineering, Environmental

Keywords: ultrasound, ultrafiltration, membrane cleaning, membrane fouling, luminol, cavitation, pitting, natural organic matter, dissolved organic matter,Aldrich, Pahokee, 13C NMR, aromaticity, oxidation

15. Cheng, Chin-Min. Leaching of coal combustion products: field and laboratory studies.

Degree: PhD, Civil Engineering, 2005, Ohio State University

► This study combines field monitoring and laboratory experiments to investigate the environmental… (more)

▼ This study combines field monitoring and laboratory experiments to investigate the environmental impacts associated with the re-use of coal combustion by-products (CCPs). The monitoring data obtained from two full-scale CCP applications allowed environmental impacts to be evaluated under real or simulated in-service conditions. A complimentary laboratory leaching study elucidated fundamental physical and chemical mechanisms that determine the leaching kinetics of inorganic contaminants from CCPs. In the first field study, water quality impacts associated with the re-use of flue gas desulfurization (FGD) material as a low permeability liner for a swine manure pond were examined by monitoring the water quality of water samples collected from pond water and sump collection system beneath the liner over a period of 5 years. In the second field study, the release of metals and metalloids from full-scale portland cement concrete pavements containing CCPs was evaluated by laboratory leaching tests and accelerated loading of full-scale pavement sections. To further elucidate the mechanisms controlling the leaching of CCPs, a flow-through-rotating-disk system was applied to investigate the mechanism, e.g., bulk diffusion, pore diffusion, or surface chemical reaction, controlling the leaching process of fixated FGD material. It was found that the leaching process was controlled by surface reaction and can be described by a combination of an intrinsic hydration reaction and a proton-promoted dissolution reaction. Also, the effects of oxalate, citrate, maleate, and Pahokee peat humic acid (PPHA) on the leaching kinetics of fixated FGD material were investigated at pH2.9 and 5. It was found that the leaching process was inhibited in the presence of oxalate at both pHs due to the formation of calcium oxalate on the leaching surface. The effects of maleate and humic acid on the leaching process were more complicated. According to ATR-FTIR analysis, both ligands were adsorbed predominantly as outer-sphere complexes on the leaching surface which either promoted or inhibited the leaching kinetics at pH 5. Both ligands, however, inhibited the leaching process at pH 2.9 by forming both inner- and outer-sphere complexes with the fixated FGD material surface. Unlike other organic ligands tested in this study, citrate significantly promoted the leaching process. Advisors/Committee Members: Walker, Harold.

Subjects: Engineering, Environmental

Keywords: coal combustion by-product (CCP), flue gas desulfurization (FGD) material, leaching mechanism, diffusion-controlled, surface-controlled, effect of pH, effect of organic ligand, ATR-FTIR analysis

16. Cheng, Fang. Sediment transport and channel adjustments associated with dam removal.

Degree: PhD, Civil Engineering, 2005, Ohio State University

► Dam removal has recently become one of the most controversial issues among… (more)

▼ Dam removal has recently become one of the most controversial issues among the environmental society community in the United States. Release of reservoir sediment is the main uncertainty associated with this issue. This study has extensively documented the short-term changes in channel geometry, bed level profile, size distribution of substrates, and their relations with the sediment transport at the reach scale after a low-head dam removal. Before the complete removal, the structure was breached to de-water the reservoir. The suspended sediment concentration (SSC) and discharge downstream of the dam showed nearly no change during the breach. In contrast, the complete removal of the structure produced a sudden increase in downstream discharge and SSC. However, the amount of increase was insignificant compared to the annual rainfall event. The SSC within 10 months after the removal showed no significant difference with that of SSC before the removal. No bank erosion was evident at both upstream and downstream of the dam; while net deposition occurred downstream and net erosion occurred in the reservoir. Deposition and scouring were evident in the reservoir with overall decrease by 30% in bed slope. Deposition measurements showed up to a 20 cm increase in bed level downstream of the dam. Downstream bed materials size became at least 40% finer for post-removal conditions than for pre-removal conditions as a result of deposition of finer materials. High resolution Digital Elevation Models (DEMs) of the river bathymetry were generated from differential GPS surveys. The volume of deposition and erosion was computed from differencing the DEM for post-removal from the DEM for pre-removal. Compared with the observations, the transport rate estimated from the DEMs overestimated the transport rate within an order of magnitude. A 1-D hydrodynamic model, calibrated with the observations showed promising simulation results on the dynamics of dam removal and sediment transport. The major features described by the model were: 1) the magnitude and timing of the flood wave during the dam removal; and 2) the bed level adjustments after dam removal. Sensitivity analysis showed that the model was strongly dependent on the size distribution of the reservoir substrates. Advisors/Committee Members: Granata, Tim C.

Keywords: dam removal, channel adjustment, sediment transport

17. Chilukuri, Sastry V. S. Extraction of vehicle information from 1-m resolution imagery.

Degree: MS, Civil Engineering, 2000, Ohio State University

► To manage the existing transportation infrastructure in an efficient manner, detailed traffic… (more)

▼ To manage the existing transportation infrastructure in an efficient manner, detailed traffic information is needed. Although, traffic information obtained from ground-based devices is temporally rich, the ground data lacks in spatial extent. Remote sensing offers a convenient platform for collecting data over large spatial extents. By integrating traffic information extracted from remotely sensed data with ground-based counter measurements, temporally and spatially rich data sets can be generated that will prove valuable for traffic studies. In this research, an attempt is made to develop an efficient vehicle detection system for deriving vehicle information like vehicle counts, vehicle class and vehicle velocity. Detection techniques that use shadows, temporal differencing and model-based methods are briefly examined before a successful region-based technique is developed. The proposed technique integrates contextual, multiresolution, radiometric, textural, geometric and multispectral information. A Geographic Information Systems (GIS) road centerline file is used to introduce the context of the roads. Daubechies' 4 tap wavelet is used to derive a three level lowpass image pyramid. Then texture properties are extracted at every resolution of the image pyramid. Principal component analysis is used to integrate the features obtained at multiple resolutions. One of the principal components is found to best isolate the vehicles. This is suitably thresholded to obtain a binary image. The geometric properties of the vehicles are used to identify the vehicles. Geometric and radiometric properties of the vehicles are used to track them across the stereo-pairs to obtain an estimate of the velocity. The developed method is tested on 1-m resolution images covering approximately 2.5 km. of highway with different types of geometry and pavement materials. The errors of commission and omission for the obtained results are examined and suitable methods are proposed to reduce these errors. Advisors/Committee Members: Merry, Carolyn J.

18. Conroy, Colton J. ADmesh: An ADvanced Mesh Generator for Hydrodynamic Models.

Degree: MS, Civil Engineering, 2010, Ohio State University

► The purpose of this research is the development and implementation of a… (more)

Subjects: Civil Engineering; Computer Engineering; Environmental Engineering; Fluid Dynamics

Keywords: mesh generator; computational hydrodynamics; fluid dynamics; ADCIRC model; distmesh

19. Corrigan, Lauren Nicole. The Effect of Dissimilatory Arsenate-Reducing Bacteria on Arsenic Release from Spent Adsorbents Under Landfill Conditions.

Degree: MS, Civil Engineering, 2012, Ohio State University

► Recent studies have observed arsenic release from spent adsorbent media under landfill… (more)

▼ Recent studies have observed arsenic release from spent adsorbent media under landfill conditions; however, the specific mechanisms causing the release remain unclear due to the numerous and complex chemical and biological processes that occur in landfills. Studies have found that bacteria can directly influence arsenic speciation, which may be a factor in arsenic release from spent adsorbent media in landfills. The purpose of this research is to investigate the role of the dissimilatory arsenic reducing bacteria (Bacillus benzoevorans strain HT-1) on arsenic release from iron oxide adsorptive media under anaerobic landfill conditions. HT-1 was cultured in synthetic leachate media with arsenate added as the sole electron acceptor. The bacteria were then transferred into large serum bottles containing the synthetic leachate and arsenic-loaded goethite media. Arsenic release was monitored under seven amended media conditions with abiotic controls: (1) lactate as the electron donor, (2) citrate as the electron donor, (3) acetate as the electron donor, (4) elevated silicate concentrations, (5) elevated sulfate concentrations, (6) elevated bicarbonate concentrations, and (7) elevated phosphate concentrations. With the exception of the acetate treatment, arsenic release was observed under each scenario in concentrations exceeding arsenic release observed under abiotic conditions. Citrate had a greater influence on arsenic release than lactate, likely due to the ability of citrate to sorb to the media and compete with arsenic for sorption sites. Therefore, the heterogeneity of organic acids in landfill leachate will likely influence arsenic release from adsorbent media differently. Concentrations of anions in landfill leachate vary between different landfills and are likely to influence arsenic release from spend adsorbent media. Elevated concentrations of bicarbonate and phosphate significantly influenced arsenic release. The increased concentration of either bicarbonate or phosphate resulted in a greater extent of arsenic reduction and release. Therefore, landfills with higher concentrations of bicarbonate and phosphate will likely see a greater extent of arsenic released from arsenic-bearing solid residuals. This research shows that the biological arsenic reduction process can enhance arsenic release from spend adsorbent media under anaerobic landfill conditions and as a result, the spent media may be a significant source of arsenic in landfill leachate. Further research is required to ascertain the predominant mechanism causing arsenic release from spent adsorbent media in landfills; however, the role of arsenate-reducing bacteria should not be overlooked. Advisors/Committee Members: Lenhart, Dr. John J.

Subjects: Civil Engineering; Environmental Engineering

20. Cotellesso, Paul. Statistical and Fuzzy Set Modeling for the Risk Analysis for Critical Infrastructure Protection.

Degree: PhD, Civil Engineering, 2009, Ohio State University

► A survey of experts that work in the protection of critical infrastructure… (more)

▼ A survey of experts that work in the protection of critical infrastructure was developed and administered that captured the data upon which the analysis rests. The survey consisted of four major sections: consent, primary data acquisition, demographic data acquisition, and closing remarks. Primary data acquisition focused on four areas: weapon implementation likelihood and a three variable: consequence, threat, and vulnerability; risk function. There were two scales used in the primary data acquisition a forced rank order and a 7-point Likert scale.Non-parametric and parametric statistical models were used to analyze the data, describe the behavior, establish relationships, and explain the phenomena. The non-parametric model, Friedman’s test, was used to ascertain a rank order based on the data from weapon implementation likelihood in the four major weapon categories: conventional, chemical biological and nuclear. The parametric model consisted of the proportional odds model which was used to explore the relationships through the risk function. The proportional odds model calculated cumulative and individual probabilities of a response level, and point estimates of severity. Confidence intervals were projected using the bootstrap method and the models were validated using internal cross validation procedures. The proportional odds model estimates consequence, threat, and vulnerability values. These values can be used separately in risk management and analysis or manipulated using other methodologies. A fuzzy logic triangle model was used to estimate risk from the consequence, threat, and vulnerability values. The model represents a reasonable estimate of risk. Critical infrastructure protection is crucial to the functioning of US society, the economy, democracy, and national security. The terrorist attacks on the World Trade Center caused a shift in strategic, operational, and tactical policy toward improving critical infrastructure protection by the public and private sectors. The policies placed new emphasis on establishing safe, reliable, survivable, and resilient infrastructure. The magnitude of critical infrastructure and limited quantity of resources available to protect it necessitates establishing a scientific methodology upon which to develop policy and make decisions. This study advances the protection of critical infrastructure knowledge through the exploration of tactics, perimeter security functions, countermeasures, and buildings relationships. Advisors/Committee Members: Tab, Fabian.

Subjects: Civil engineering

Keywords: Critical Infrastructure Protection, Perimeter Security, Fuzzy Triangular Model, Proportional Odds Model, Friedman's Test

21. Danatzko, Joseph M. Sustainable Structural Design.

Degree: MS, Civil Engineering, 2010, Ohio State University

► Efficient energy use during construction and operation of buildings and sustainable building… (more)

▼ Efficient energy use during construction and operation of buildings and sustainable building design are important issues in both modern society and the engineering community. Innovative methods are needed to address the environmental impact, energy use and other sustainability issues faced during planning and design of buildings. This study investigates sustainable design methodologies, the relationships between structural system and the 2009 Leadership in Energy and Environmental Design (LEED) rating system, the impact that project size and type can have on project sustainability, sustainable properties associated with construction materials (such as steel, cast-in-place concrete and prestressed/precast concrete) and computer programs aimed at determining the properties of sustainable structural design alternatives. This study investigates some sustainable structural design methodologies including minimizing material use, minimizing material production energy, minimizing embodied energy, life-cycle analysis/inventory/assessment and maximizing building reuse and presents their positive and negative sustainable qualities. This study discusses and reviews the categories of the 2009 LEED rating system in which points could be awarded to a project for sustainability of its structural frame. This study presents the role that project size and structural system-type play on aspects of sustainable design including the design and analysis phase, land use, investments in sustainable technologies, use of timber as a primary load bearing material and other sustainable issues. This study reviews the structurally applicable sustainable properties associated with structural steel, cast-in-place and prestessed/precast concrete. Finally, this study provides a review of life-cycle analysis computer programs focusing on three (Building for Environmental and Economic Sustainability (BEES) v4.0, SimaPRO v7.1 and Athena Impact Estimator v4.0) aimed at assessing the sustainability of design alternatives. This study determined that no single current sustainable design methodology can address all project sustainability issues at this time. Also, the LEED 2009 rating system does not reward projects for sustainable design of their structural systems in the same manner it does other aspects of design. It was determined that construction type and project size can have significant impact on sustainable opportunities for a project and that no single construction material is the most sustainable compared to others for all design types at this time. Finally, existing sustainability analysis software does not meet the current needs of its users in assessing design alternative sustainable properties and provides users with basic structural system comparisons, as exemplified by parametric studies using the Athena Impact Estimator v4.0. Advisors/Committee Members: Sezen, Halil.

Subjects: Architecture; Civil engineering

Keywords: Sustainability, Construction Materials, Sustainable Design Methodologies, Construction Type, Design Alternatives, LEED, Sustainable Analysis Computer Programs

22. Dibling, David R. Development And Validation Of A High-Resolution, Nearshore Model For Lake Erie.

Degree: MS, Civil Engineering, 2012, Ohio State University

► The purpose of this research is to make progress toward correcting the… (more)

Subjects: Civil Engineering; Computer Engineering; Environmental Engineering; Fluid Dynamics

Keywords: Lake Erie; ADCIRC; SWAN; hydrodynamic model; hindcast; finite element; fluid dynamics

23. Dicken, Christopher L. An Expert System Approach to Best Management Practice Selection for Nominal Scale Low-Impact Redevelopments.

Degree: MS, Civil Engineering, 2011, Ohio State University

► Commissioned by a world appealing for sustainable efforts, those charged with the… (more)

▼ Commissioned by a world appealing for sustainable efforts, those charged with the development and restoration of our nation’s infrastructure have discovered a need for alternatives to prior unsustainable designs. In order to contend with this demand for innovation, civil engineers must continue to foster sustainable practices in their profession. This state of affairs requires that alternative construction methods be conveyed to those capable of implementing fresh approaches. Mechanisms for controlling stormwater runoff are one such item of infrastructure which benefit from this re-evaluation of intrinsic conventions. Stormwater Best Management Practices (BMPs) have emerged as the result addressing the need for more sustainable stormwater control. With the aforementioned interest in sustainable practices and the requisite for new infrastructure, a system to convey the efficacy of BMPs can assist in the adoption of these practices as mainstream applications. To help realize this premise, a software package was developed to introduce the concept of sustainable hydrological developments to those with the interest, influence, or capability to include these features in their designs. This package includes a fully-customizable BMP database, a knowledge-based expert system able to recommend BMPs for a site, and a component to rate the sustainability of a site’s hydrological function. The customizable BMP database allows for the centralization of alterative stormwater management practices molded to the destination environment. The expert system is an interactive way to provide less-experienced personnel with contending BMPs backed by expert intuition. Sustainability is a subjective topic, and to properly rate a development as sustainable, a more firm definition of sustainability is necessary in order to convey a clear message and provide for dependable comparisons. Therefore, several fuzzy logic applications are incorporated into this software program to clarify measures of hydrological sustainability. This software package provides an interactive system for those who wish to learn about stormwater BMPs. While several tools exist to aid in the design and placement of BMPs, these programs often expect the user to collect a significant amount of information before they are of use. By using the system developed here, the dissemination of knowledge held by established professionals can be conveyed to those with a lesser understanding of BMPs. This in turn promotes BMPs to a wider audience where the program acts as a higher level application that is able to supplement existing software, or perform independently. Advisors/Committee Members: Tan, Fabian.

Subjects: Civil Engineering; Engineering; Hydrology; Sustainability; Transportation

Keywords: best management practices; expert system; street; road; reconstruction; stormwater; fuzzy logic; sustainability; runoff; low-impact development; residential

24. Dusini, Douglas S. The effect of Lake Erie water level variation on sediment resuspension.

Degree: MS, Civil Engineering, 2005, Ohio State University

► A recent decline in water level on Lake Erie may result in… (more)

Keywords: incipient motion; sediment resuspension; Lake Erie; hydrodynamic; GLFS; closure contour

25. Elmir, Wassef E. Spatial interaction between cross frames and girders of multi-stringer skewed steel bridges.

Degree: MS, Civil Engineering, 1988, Ohio State University

Advisors/Committee Members: Bishara, Alfred G.

26. Erb, Ronald T. The effect of roots on the shearing strength of soil.

Degree: MS, Civil Engineering, 1985, Ohio State University

Advisors/Committee Members: Wu, T. H.

Keywords: SOIL; ROOTS; Model Root; Shear Strength; SOIL-ROOT

27. Farmer, Danny Dale. An evaluation of the fire resistive qualities of wall assemblies with gypsum wallboard membranes.

Degree: MS, Civil Engineering, 1973, Ohio State University

Advisors/Committee Members: Bletzacker, Richard W.

28. Fisco, Nicholas Robert. Comparison of Macrotexture Measurement Methods.

Degree: MS, Civil Engineering, 2009, Ohio State University

► This study investigates and compares mean profile depth (MPD) measurements from three… (more)

Subjects: Civil engineering

Keywords: macrotexture, mean profile depth, MPD, mean texture depth, MTD, pavement, friction

29. Fisher, Matthew John. Experimental Evaluation of Reinforcement Methods for Concrete Beam-Column Joints.

Degree: MS, Civil Engineering, 2009, Ohio State University

► Prefabricated Cage System (PCS), a new method of reinforcement for concrete members,… (more)

Subjects: Engineering

Keywords: Beam-column joints, steel reinforcement, reinforced concrete, shear failure

30. Foos, Bryan Carl. Damage progression in composite plates due to low velocity impact.

Degree: MS, Civil Engineering, 1990, Ohio State University

Advisors/Committee Members: Wolfe, William E.

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