PHD, Kent State University, 2023, College of Arts and Sciences / Department of Biological Sciences

Climate change is exerting profound and far-reaching impacts on ecosystems worldwide, encompassing both aquatic and terrestrial environments. The evolving precipitation patterns and shifting temperature regimes impact fluctuations in hydrology, resulting in shifts in redox conditions which can impact the availability of nutrients like phosphorus (P). Phosphate, the bioavailable form of P, is only present in small amounts within soils, making the biological demand greater than soil phosphate availability. The majority of soil P is present in non-labile forms including organic P and phosphate sorbed to metal oxides like iron (Fe). Microorganisms must content with geochemical and other abiotic factors to access phosphate from these non-labile sources through the use of various strategies including the secretion of enzymes, the production of phosphate solubilizing acids, as well as indirect mechanisms associated with the reduction of Fe oxides. The primary goal of this dissertation was to advance our understanding of how microorganisms access both labile and non-labile forms of P in the presence of changing hydrologic and redox conditions which impact the speciation of Fe that is present, altering phosphate availability. Specifically, I investigated 1) how phosphate availability changes across a permafrost thaw gradient (palsa, bog, and fen) in the presence of iron oxides, 2) how microorganisms access and mobilize chemically diverse phosphorus sources under contrasting redox conditions, and 3) how changes in hydrology, redox, iron mineralogy, and phosphate availability drive shifts in microbial community composition, specifically iron oxidizers, reducers, and phosphate solubilizers. In our first study assessing microbial phosphate accessibility across a permafrost thaw gradient, we found that near surface redox conditions changed as a function of permafrost thaw which impacted phosphate availability. Reducing conditions in the bog promoted the dissolution of Fe oxides, (open full item for complete abstract)

Committee: Lauren Kinsman-Costello (Advisor); Christie Bahlai (Committee Member); David Costello (Committee Member); Christopher Blackwood (Committee Member); Elizabeth Herndon (Committee Member); Timothy Gallagher (Committee Member) Subjects: Biogeochemistry; Climate Change; Ecology; Geobiology; Geochemistry; Microbiology; Mineralogy; Soil Sciences

Bachelor of Science, Wittenberg University, 2023, Biology

The Painted turtle (Chrysemys picta) is a widespread North American species, and its subspecies found in Ohio is the Midland Painted turtle (Chrysemys picta marginata). While it is generally a widespread species and less at risk than other freshwater turtle species, understanding different local populations of the species can help us better understand the species as a whole, as well as factors that may play a role in conserving other freshwater turtle species. I conducted a mark-recapture study over the course of two separate study periods to assess the Midland Painted population in Conrad Balliet Family Nature Preserve's Pond, a local pond in Clark County, Ohio. Of the turtles recorded, 28 individual turtles were captured, and there was a 1.33:1 ratio of male turtles to female turtles and a 0.19:1 ratio of juveniles to adult turtles. Males tended to be in higher abundance in traps when there were few females and accounted for more recaptures than females. The estimated population size for the pond is 30 Midland Painted turtles. Males were smaller in size than females, in carapace length and width, plastron length and width, shell height, and weight. This information, and further studies on the pond's population, can serve to inform conservation methods for this species and other applicable freshwater turtle species as is relevant.

Committee: Richard Phillips (Advisor); John Ritter (Committee Member); Kathleen Reinsel (Committee Member) Subjects: Animal Sciences; Animals; Biology; Conservation; Ecology; Environmental Science; Environmental Studies; Wildlife Conservation; Wildlife Management; Zoology

Master of Science, The Ohio State University, 2022, Environment and Natural Resources

Small artificial ponds are widely distributed throughout the United States and represent a considerable human footprint on the aquatic landscape. Management of these freshwater systems differ somewhat and are dependent on individual landowner decisions. While many management actions are directed toward one or two components of a pond, different management strategies are implemented as landowners invest varying amounts of time and effort in pond management. Active management of ponds come in varying degrees and approaches and include such practices as the removal of vegetation through mechanical or chemical (e.g. herbicides) means, fish stocking, aeration, and dredging. These actions are often meant to improve environmental conditions for aquatic wildlife, especially fish, however increasing levels of management present greater human induced disturbances that may be counterproductive to management goals. I used a combination of field surveys and an experimental study to investigate the effects of management activities on fish health, biodiversity, and water quality. The field surveys consisted of repeated sampling efforts of artificial ponds in rural Ohio. I found that increased management had little effect on water quality parameters (e.g. dissolved oxygen, conductivity, turbidity, etc.). Likewise, taxonomic richness and diversity measures (Shannon's Diversity Index) of aquatic macroinvertebrates were not affected by increased management. I did find differences in presence of several taxonomic orders across increasing intensities of management which contributed to disparity in macroinvertebrate community assemblages. This indicated that increased management inputs, or even specific actions, could affect favorability of environmental conditions for unique taxonomic groups. I also found no differences in fish abundance or health between ponds. My findings from the field surveys suggest two possible explanations. First, increased management actions did not negatively i (open full item for complete abstract)

Committee: Suzanne Gray (Advisor); Robert Gates (Committee Member); Rachel Gabor (Committee Member) Subjects: Environmental Management; Fish Production; Freshwater Ecology; Wildlife Management

Master of Science (MS), Wright State University, 2021, Earth and Environmental Sciences

Excess loading of nitrogen (N) and phosphorus (P) is a serious global problem and has numerous negative impacts on water quality of aquatic ecosystems including eutrophication, harmful algal blooms, and hypoxia. Anthropogenic activities (such as the Haber-Bosch process, burning of fossil fuels, sewage treatment, and manure reuse) have led to excess N loading to aquatic systems. Sediment N dynamics were examined from Oct 2019 – Oct 2020 in an agricultural settling pond connected to a constructed wetland adjacent to an agricultural field. Intact sediment cores were amended with 15N for continuous-flow incubations to measure denitrification and N fixation rates, as well as net nutrient and oxygen fluxes. Net N2 consumption (N fixation > denitrification) was observed over most of the year, suggesting that pond sediments were a net N source. Denitrification was stimulated when 15N-nitrate was added, and net denitrification was observed following a N fertilizer application in May 2020. NOx entering the wetland and settling pond was rapidly transformed or assimilated. However, during winter and following fertilizer application, ambient NOx concentrations increased in the wetland, but remained lower in the settling pond, suggesting rapid N removal in the pond. Sediment oxygen demand and potential denitrification rates increased in warmer months, suggesting greater microbial activity and organic matter decomposition. Settling ponds in agricultural settings thus have the potential to supplement agricultural nutrient control practices. Further research should focus on understanding the frequency, timing, and amount of N loading that enters field-adjacent wetlands and ponds to determine if the sediments will consistently function as a net N sink and to maximize denitrification efficiency.

Committee: Silvia E. Newell Ph.D. (Advisor); Mark J. McCarthy Ph.D. (Committee Member); Rebecca E. Teed Ph.D. (Committee Member) Subjects: Biogeochemistry; Environmental Science

MFA, Kent State University, 2021, College of the Arts / School of Art

"What Comes After the Blues" is an art installation by Matt Kurtz that uses found objects, video and performance art to reclaim identity in the ruins of industry and faith. The videos and projections exhibit dualities through site-specificity and personal narrative. Spiritual objects are reimagined while abandoned materials are sanctified. Oftentimes the objects in this installation serve as material memory for past experiences and expand on the concepts of the videos they interact with. Viewers are given the opportunity to participate in the installation through sound performance and meditative play. In his artwork, Kurtz enters the sacred voids of his past and considers local mythology, musical familiarity and the evangelical conditions of his background to convey his experience.

Committee: Eli Kessler (Advisor) Subjects: American History; Art History; Fine Arts; Folklore; Music; Religion

MS, Kent State University, 2021, College of Arts and Sciences / Department of Earth Sciences

The Marcellus Formation is a Devonian age shale play in the Appalachian Basin and is an economical energy resource in the Eastern United States. This formation is known to contain high amounts of total organic carbon (TOC), which is one method used to estimate the possible productivity, and therefore economic feasibility, of drilling a well. More recently, degree of pyritization has been another method utilized in answering this same question. This method has even been referenced as the standard to compare geochemical paleo-redox proxies and is based on the idea that the preservation of organic matter is affected by the degree of bottom-water oxygenation. Oxic environments are less favorable for organic matter preservation, whereas anoxic-euxinic conditions are more conducive of organic matter preservation. However, the degree of pyritization method does not distinguish between anoxic and euxinic conditions and it is based upon the assumption that the sulfur values measured in the lab had exclusively a pyritic source. This leads to the following questions: “Are there environments in which degree of pyritization should not be held as the standard method for comparing geochemical paleo-redox conditions?” and “What method(s) can be used to confirm that the degree of pyritization method should be used for a specific set of samples?” The focus of this research was to compare 34 samples from a Marcellus Shale core taken from a producing well in West Virginia to 50 samples from the modern Sluice Pond in Lynn, Massachusetts. The Marcellus Shale core represents an oil and gas play that has proven to be economical. In this study it acts as the industry standard to which the Sluice Pond is being compared. The primary methods used for this comparison were (1) degree of pyritization and (2) framboidal pyrite size and abundance. These two methods allowed for relationships to be drawn between pyritic iron (Fepyr), acid soluble iron, (Fesol) pyritic sulfur (Spy (open full item for complete abstract)

Committee: Jeremy Williams (Advisor); Joseph Ortiz (Committee Member); David Singer (Committee Member) Subjects: Geology

Doctor of Philosophy, University of Toledo, 2019, Biology (Ecology)

Invasive species are one of the top threats to native biodiversity. Their population genetics and genomics can be useful in control and management of invasive species and can be regarded as accidental evolutionary experiments. Here, in a temporal study of the high impact invasive round goby Neogobius melanostomus in the Laurentian Great Lakes, the ability of invasion genetics to track sources and temporal changes in population structure was demonstrated. We tested for three possible alternative temporal patterns in population genetic diversity over time – termed the `genetic stasis', `supplementation', and `replacement' hypotheses. `Genetic stasis' or no change in allelic composition over time could be caused by a large number of introduced propagules that possibly possess all (or most) of the diversity present in the native source, or by a density dependent process circumventing the establishment of later arrivals. Alternatively, there may be `genetic supplementation' in which populations that experienced an initial founder effect then gain diversity over time. Finally, `replacement' of all or some of the initial founding genetic diversity could result when the early arrivals are the best dispersers, followed by those that are better competitors. Results showed that near the site of initial establishment (the invasion core), high genetic diversity due to a large number of introduced individuals precluded significant changes in allelic composition over time. Further from the invasion core, some slight changes in genetic diversity occurred soon after population establishment. Results supported `genetic stasis' and the founder takes all hypothesis. Due to the territoriality of adult round gobies, it is possible that a density dependent process circumvented establishment of later arrivals. Additional introductions from separate native sources were implicated in some areas of the invasion. Detection of newly introduced species before they can become established and (open full item for complete abstract)

Committee: Carol Stepien (Committee Chair); Jonathan Bossenbroek (Committee Member); Kerry Naish (Committee Member); Matthew Neilson (Committee Member); Von Sigler William (Committee Member) Subjects: Bioinformatics; Biology; Ecology; Genetics; Organismal Biology

Master of Science, University of Akron, 2017, Geology-Environmental Geology

Population growth during the 20th century in Northeast Ohio has led to an overall increase in developed land cover and anthropogenic pollution such as fossil fuel combustion. Urban expansion and fossil fuel combustion result in an increase of polluted runoff into fluvial systems, which jeopardizes water quality, undermines infrastructure, and stresses local ecosystems that buffer floods. This study compares heavy metal pollution levels and land cover change during the 20th century in dammed impoundments within the rural Haskell Run watershed (Lake Butler), the rural Ritchie Run (Lake Litchfield), and the urban Mud Brook watershed (Old Mill Pond) in Northeast Ohio. Surficial sediment samples were collected from each impoundment to assess current pollution levels and sediment cores were collected for the past record of pollution. The two end-member watershed types have similar bedrock, glacial history, and climate, however, land cover differs greatly. Between 1985-2010, there was no land cover change in the rural Ritchie Run watershed, and in 2010, Ritchie Run had 3.4% developed land cover and 0.63% impervious cover. During the same period, the rural Haskell Run watershed increased by 1.37% in developed land cover, and in 2010, 12% of the Haskell Run watershed was developed land and 3.3% was impervious cover. Developed land cover, from 1985-2010, increased by 15.3% in the urban Mud Brook watershed, and in 2010, 74% was developed land cover and 23% was impervious cover. Old Mill Pond impoundment sediments were found to have higher heavy metal and ferrimagnetic concentrations, whereas, Lakes Butler and Litchfield sediments have comparatively lower heavy metal and ferrimagnetic concentrations. There is a moderate direct relationship between heavy metal and ferrimagnetic content. Therefore, magnetics can be used as an inexpensive and rapid screening tool for heavy metal pollution studies. The Old Mill Pond sediment core records an increase in heavy metal and ferrimagnetic (open full item for complete abstract)

Committee: John Peck (Advisor); John Senko (Committee Member); Linda Barrett (Committee Member) Subjects: Environmental Geology

Master of Science (MS), Ohio University, 2016, Civil Engineering (Engineering and Technology)

Raceway ponds for microalgae are broadly used in cultivating microalgae for high production because of their effectiveness and cost savings. One of the challenging factors of microalgae growth is how to optimize the impact of mixing during cultivation. The effects of light characteristics, LED, and fluorescence, are also significant for growing microalgae. Mixing paddlewheel speeds were investigated using speeds at 11 rpm, 13 rpm, and 15 rpm. Maximum algae concentrations and growth rates were higher with higher rpm. Shear calculations showed that these mixing rates were not high enough to injure cells. Maximum velocities in raceways varied from 16.5 to 41.8 cm/s, adequate for mixing. LED lights were more effective than fluorescent likely due to higher intensity and better radiation spectra. Growth nearly stopped after six days due to high turbidities that greatly diminished light penetration. A CFD model matched measured velocities well and showed eddy problems were more severe at lower mixing rates.

Committee: Guy Riefler R. (Advisor); Shad Sargand (Committee Chair); Sarah Davis (Committee Member); Ben Sperry (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy (PhD), Wright State University, 2013, Computer Science and Engineering PhD

A sensor network serves as a vital source for collecting raw sensory data. Sensor data are later processed, analyzed, visualized, and reasoned over with the help of several decision making tools. A decision making process can be disastrously misled by a small portion of anomalous sensor readings. Therefore, there has been a vast demand for mechanisms that identify and then eliminate such anomalies in order to ensure the quality, integrity, and/or trustworthiness of the raw sensory data before they can even be interpreted. Prior to identifying anomalies, it is essential to understand the various anomalous behaviors prevalent in a sensor network deployment. Therefore, we begin this work by providing a comprehensive study of anomalies that exist in a sensor network deployment, or are likely to exist in future deployments. After this thorough systematic analysis, we identify those anomalies that, in fact, hinder the quality and/or trustworthiness of the collected sensor data. One approach towards the reduction of the negative impact of misleading sensor readings is to perform off-line analysis after storing a large amount of sensor data into a centralized database. To this end, in this work, we propose an off-line abnormal node detection mechanism rooted in machine learning and data mining. Our proposed mechanism achieves high detection accuracy with low false positives. The major disadvantage of a centralized architecture is the tremendous amount of energy wasted while communicating the sensor readings. Therefore, we further propose an on-line distributed anomaly detection framework that is capable of accurately and rapidly identifying data-centric anomalies in-network, while at the same time maintaining a low energy profile. Unlike previous approaches, our proposed framework utilizes a very small amount of data memory through on-line extraction of few statistical features over the sensor data stream. In addition, previous detection mechanisms leverage sensor (open full item for complete abstract)

Committee: Bin Wang Ph.D. (Advisor); Yong Pei Ph.D. (Committee Member); Keke Chen Ph.D. (Committee Member); Shu Schiller Ph.D. (Committee Member) Subjects: Computer Engineering; Computer Science

Master of Science (MS), Ohio University, 1989, Mechanical Engineering (Engineering)

Computer simulation of Ringbom stirling engine with solar pond

Committee: Israel Urieli (Advisor) Subjects: Engineering, Mechanical

Master of Science (MS), Ohio University, 2001, Chemical Engineering (Engineering)

Evaluation of the flue gas desulfurization mine seal and sedimentation pond at Broken Aro Mine Reclamation Site located in Coshocton County, Ohio

Committee: Ben Stuart (Advisor) Subjects: Engineering, Chemical

Master of Environmental Science, Miami University, 2010, Environmental Sciences

This report is an inventory of types of stormwater management practices, both the poor and the best, in the City of Oxford. A structure or practice is regarded as a “poor stormwater management practice” if it increases peak flow, decreases base flow, increases or does not eliminate pollution, exacerbates erosion and degrades aquatic habitats. These practices include connected impervious surfaces, poorly designed or poorly managed stormwater infrastructure, uncollected trash and pet waste. A structures and practices is regarded as a stormwater “best management practice” if it reduces peak flow, increases baseflow, eliminates or does not contribute to stormwater pollution and does not degrade streams and aquatic habitats. Such practices include pervious pavers, filter strips, storm drains, rain gardens, disconnected impervious surfaces, street sweeping, vegetated depressions and retention gardens. This study does not attempt to uncover issues of policy regarding stormwater management in the city. Some recommendations on how the City of Oxford could encourage stormwater best management practices are given in the end. A glossary of key stormwater terms is also provided.

Committee: Mark R. Boardman PhD (Advisor); David L. Prytherch PhD (Committee Member); Donna S. McCullom PhD (Committee Member) Subjects: Hydrology

MA, Kent State University, 2011, College of Arts and Sciences / Department of Anthropology

Paleoindian toolkits represent successful adaptations to the unique and varying environments that existed in North America at the end of the Wisconsin glacial period. Because such adaptations were ecologically influenced, different emphases appear in toolkits throughout the continent which provide insight into the lives of these people. Compared to sites in western North America, sites in the eastern woodlands demonstrate a dramatic increase in the amounts of stone end scrapers that have been recovered from Paleoindian contexts. This disparity points to the fact that the activity or activities associated with these tools became more adaptively significant. Nobles Pond, a Gainey phase (ca. 11,200 BP) Paleoindian site in northeastern Ohio, contains the largest collection of end scrapers recovered to date. This assemblage represents a unique opportunity to systematically study the morphological characteristics of these tools to create a general use-life of end-scrapers in an eastern Paleo-Indian context. Detailed observation of features such as form, size, and symmetry will help outline a sequence of production, use, and depletion. This use-life model helps support the conclusion that Paleoindian end scrapers were functionally redundant; the variation exhibited by this class of tools is seen as a result of extensive retouch and depletion.

Committee: Mark Seeman (Committee Chair); Richard Meindl (Committee Member); T. Kam Manahan (Committee Member) Subjects: Archaeology

Master of Science, University of Akron, 2009, Geology-Environmental Geology

The field of paleotempestology has gained more awareness in the past decade as a result of increased hurricane intensity, quantity, and duration within the late Holocene. One of the best localities to find records of hurricane overwash deposits is in the Bahamian islands. San Salvador Island, Bahamas (SSI) is a small (150km2), isolated carbonate platform, that contains shallow (0.5-3m) saline lakes that occur in between interdune areas of arcuate dune ridges. Due to San Salvador Island's location within the Bahamian archipelago and the Atlantic Ocean, the island is poised to record hurricane strikes and the record of these events can be found in coastal lakes. Clear Pond is a shallow (~1m), variably saline (16-30 ppt) lake in the southwestern edge of the island, that is separated from the Atlantic Ocean by Holocene dunes. It was a previously uncharacterized pond, but like many other depositional environments on San Salvador, it is constantly recording climatic and anthropogenic changes on the island. This study addresses the following questions: 1) Is there a seasonal salinity variation within the pond and what is the general limnology of the pond, 2) Can we identify large storm events in the sedimentary record of Clear Pond, and 3) What is the depositional history for Clear Pond for the past 4000 years? Nine sediment cores, ranging in length from 50 to 150 cm, were recovered from Clear Pond. The cores were analyzed for organic and carbonate content, dry bulk density, grain size, sediment fabric, and mollusk and ostracode composition. Additionally, x-ray fluorescence, spectrophotometry, and x-radiography were carried out on sediment cores. Salinity varied from brackish conditions in the summer and fall to more marine during the winter and spring seasons. It was also influenced by a previously uncharacterized karst conduit. Large storm events were identified through an increase in grain size and dry bulk density, and additionally by x-radiographs. A catastrophic hurr (open full item for complete abstract)

Committee: Lisa Park PhD (Advisor) Subjects: Geology; Paleoecology