PhD, University of Cincinnati, 2023, Engineering and Applied Science: Computer Science and Engineering

Given a test input, not knowing the expected output of the software under test (SUT) is called the oracle problem. An emerging method of alleviating the oracle problem is metamorphic testing (MT). Rather than focusing on the correctness of output from a single execution of the SUT, MT exploits metamorphic relations (MRs) as derived oracles for checking the functional correctness of the code. Although researchers have argued that MT can be a simple and effective technique to help software developers, little is known about the actual cost of constructing MRs in real-world software and the relationship between MT and the already well-adopted method in software development. This research examines a series of practices to evaluate the effectiveness of MT during software development. Our investigation is conducted within the context of a real-world scientific software, the Storm Water Management Model (SWMM), developed and maintained by the U.S. Environmental Protection Agency (EPA). To ensure SWMM's accuracy in modeling stormwater runoff and executing hydraulic and water quality simulations, the development team continually evolves the software. Among the challenges they face, software testing stands out as one of the most technically complex tasks. Our research initially investigates the current testing practices and software quality assurance (QA) workflows in scientific software development, taking the SWMM as a case study. The value of our work resides in the qualitative characterizations and quantitative assessments of the tests that scientific software developers have independently written and released within the SWMM context. Our findings indicate that oracles indeed play a role in scientific software testing. Furthermore, by employing an empirical approach, we identified four critical requirements for the improved integration of MT into scientific software development. Constructing MRs is critical because without them, MT cannot b (open full item for complete abstract)

Committee: Nan Niu Ph.D. (Committee Chair); Wen-Ben Jone Ph.D. (Committee Member); Tingting Yu Ph.D. (Committee Member); Boyang Wang Ph.D. (Committee Member); Michelle Simon Ph.D. (Committee Member) Subjects: Computer Science

Doctor of Philosophy, University of Toledo, 2022, Engineering

Polyethylene terephthalate (PET) is used in packaging and textile industries such as in productions of water bottles and packaging of soft drinks. As the PET products have short lifetimes, they turn into waste rapidly. Since the market for PET products has been constantly expanding, the rate of PET waste has been increased. This may negatively affect the environment and living species. In addition, PET is produced from fossil fuels, a limited resource that should be reserved to decrease the adverse effects of its applications on the environment. Therefore, recycling has been proposed as a resolution to PET waste. Chemical recycling can decompose PET to the associated oligomers and monomers. This may provide an alternative resource for reproduction of PET and subsequently PET products. In this dissertation, hydrolysis was studied- a technique for chemically recycling of PET waste. In chemical recycling, the factors affecting the rate of PET decomposition are PET shape, PET size, reaction temperature, reaction pressure, catalyst type, catalyst concentration, and surface wetting. Few studies are reported on surface wetting. So, the main interest of this dissertation was to explore the effect of surface wetting on the rate of PET decomposition in hydrolysis reactions. In this dissertation, series of catalysts were introduced that could increase the rate of PET decomposition due to the better surface wetting of PET particles occurring with the solutions of these catalysts during the hydrolysis of PET. This effect was explored by applying a shrinking core model to interpret the kinetics data of TPA yield for calculations of reaction rate constants. These constants were correlated to the partition coefficient and distribution coefficient values of catalysts for the octanol/water system to indirectly study the PET/water system in hydrolysis. This revealed the role of functional group in catalyst structure as a determining factor for the hydrophobicity of catalyst solution (open full item for complete abstract)

Committee: Maria R. Coleman (Committee Chair); G. Glenn Lipscomb (Committee Member); Defne Apul (Committee Member); Constance A. Schall (Committee Member); Dong-Shik Kim (Committee Member) Subjects: Chemical Engineering; Chemistry; Engineering; Environmental Engineering; Environmental Science; Experiments; Materials Science; Mathematics; Mechanical Engineering; Organic Chemistry; Packaging; Plastics; Polymer Chemistry; Polymers; Sustainability

Master of Science in Civil Engineering, Cleveland State University, 2017, Washkewicz College of Engineering

Urbanization causes a serious impact on storm water systems by expansion of impervious surfaces. Low Impact Development (LID) is a technique growing in popularity to solve the issue of storm water management. However, to evaluate the benefits of LIDs is a difficult task due to realistic parametrization of LIDs and subcatchments for modeling. The goals of this study are: a) to provide a practical guideline to parameterize and simulate LIDs (bio-retention and rain barrels) in residential areas; and b) to evaluate the resulting effect on the current drainage system under various design storms. U.S. Environmental Protection Agency's Storm Water Management Model 5 (SWMM5) was used to simulate the hydrologic performance of LID controls and their effects on reducing direct runoff from a residential area, Klusner Avenue in Parma, Ohio. This study conceptualized the study site in reasonable detail, including house, garage, backyard, tree lawn, driveway, sidewalk, and street, so that the performance of LID controls could be identified easily. Specifically, a street catchment was carefully modeled using an open-conduit routing option, which simulated the street drainage systems more effectively. SWMM5 parameters were calibrated using the observed rainfall-runoff data which was collected before implementing LID practices at Klusner Avenue. The Nash-Sutcliffe efficiency (NSE) had a value of 0.69 for the calibrated model which indicates a strong fit between the output and observed data. Finally, the calibrated model was used to add LID controls to evaluate its effects under various design storms, 1-year, 2-year, 5-year, 10-year, 25-year, and 50-year return periods. The results show that two types of LID controls, bio-retention cell and rain barrel installed in the study site reduced the total runoff volume from 9 to 13% and the peak flow by from 11 to 15% depending on rainfall intensities. The analysis of results suggested that the performance of LID controls should be based on n (open full item for complete abstract)

Committee: Ung Tae Kim Ph.D. (Committee Chair); Jacqueline Jenkins Ph.D. (Committee Member); Yung Tse Hung Ph.D. (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy, The Ohio State University, 2010, Environmental Science

Conservation management practices are considered one of the best answers to escalating water quality deterioration by nonpoint source pollution. Integrated watershed economic model (IWEM) offers a multidisciplinary framework by addressing both the biophysical and the economic (cost and benefit) aspects of water quality improvement. An IWEM would have: a watershed model, an economic model, and an integration tool. Components of IWEM were translated into three essays of the dissertation and applied to the Upper Big Walnut Creek (UBWC) watershed in central.The modeling of the UBWC watershed was performed in the first essay. Soil and Water Assessment Tool (SWAT) was used to predict the nutrient export associated with land management practices. A new integrated calibration procedure was introduced for the calibration and validation of the UBWC watershed model. The predicted flow for daily, monthly and annual time scales were not statistically different from the measured values. Moreover, the predicted crop yield was also not statistically different from the reported values. Nitrate fluxes, calibrated using the field measured values at the two paired sub-watersheds, predicted nitrate loading was statistically not different from the measured values. The uncertainty analysis showed that the model predicted flow and nitrate load was with the lowest uncertainty. Recreational value of water quality improvement was estimated in second essay by using a combined revealed and stated preference method with baseline dependence and unobserved heterogeneity modeling. A mailed survey method was used to collect data, in which 1400 registered anglers and licensed boaters in 5 surrounding counties of the watershed were selected for the study. The baseline average number of trips was 2.35, which was reduced to 1.72 with more information about pollution level in the watershed. However, water quality improvement would increase the number of trips to 2.78. The average annual consumer surplus (open full item for complete abstract)

Committee: Brent Sohngen D.F (Advisor); Douglas Southgate PhD (Committee Member); Fausey Norman PhD (Committee Member); Kevin King PhD (Committee Member); Jonathan Witter PhD (Committee Member) Subjects: Agricultural Economics; Environmental Science

Doctor of Philosophy, The Ohio State University, 2002, Soil Science

Research was conducted to determine how water table management affects select physical properties and carbon fractions of a Hoytville clay loam soil. The research took place at the Northwest Branch of the Ohio Agricultural Research and Development Center in Wood County, Ohio. Water table management treatments included subsurface drainage and subsurface drainage with subirrigation. Subirrigation was applied during the vegetative, flowering and seed fill stages of crop growth to maintain a constant water table at 0.25 m below the surface and prevent moisture stress in the crops. The cropping system was a corn soybean rotation with fall tillage with a chisel for both crops and spring leveling with a Roterra before planting soybeans. Results show a difference in water stable aggregates (WSA) at a depth of 0.4 – 0.75 meters with the subirrigated treatment having a lower percentage of WSA. The mean weight diameter of aggregates in the subirrigated treatment was smaller than in the subsurface drainage treatment at a depth of 0.3 – 0.75 meters. A shift in the pore size distribution toward smaller pores in the subirrigated treatment further supported “loss of stable soil structure” theory for the subirrigated treatment. Penetration resistance measurements also revealed a change in the structural stability of the soil at a depth of 0.30 – 0.45 meters. No differences were seen between water management treatments in the carbon fractions of the upper 0 – 0.20 meters of the soil. The CENTURY model was tested to determine if it could be used to predict levels of soil organic matter as a result of subirrigation. The model was unable to predict the amount of total SOM in the soil unless the starting value of carbon was lowered well below actual values. Subirrigation of the Hoytville soil led to a loss of stable structure at a depth of approximately 0.40 meters in the soil. The exact reason for the loss of soil structure is unclear but may be related to long periods of saturation res (open full item for complete abstract)

Committee: Norman Fausey (Advisor) Subjects: