Master of Science (MS), Wright State University, 2010, Biological Sciences

Emerald Ash Borer (EAB) is more damaging to North American ashes than Asian ashes. Variation in the resistance of ash species to feeding by larvae of EAB may be related to variation in levels of chemical defenses in the phloem. I compared constitutive and methyl jasmonate (MeJA)-inducible levels of several chemical defenses in the phloem of young Manchurian, Chinese, white, and green ashes. Manchurian ash is known to be highly resistant to attack by EAB in the field, while white and green ashes are both susceptible. The hypotheses of this experiment were that: (1) Manchurian (Fraxinus mandshurica) and Chinese ash (Fraxinus chinensis) trees' phloem or bark contains concentrations of unique secondary compounds and higher level of defense protein activities than white and green ash. (2) MeJA treatment will induce increases in content of protein, Peroxidase (POD), polyphenol oxidase (PPO) content and most of the secondary compounds in all species. Phloem extracts of Manchurian ash showed higher total soluble protein content and significantly faster browning than white and green ash, but lower peroxidase activity and polyphenoloxidase activity. Activities of PPO, POD, phenolic and lignin content, and the rate of browning reactions were not found to exhibit differences between MeJA treated and untreated groups. However, our HPLC results revealed Manchurian ash contained nine unique phenolic compounds: Homovanillic Alcohol, Esculetin, Esculin Related Cmpd, Esculin, Fraxin, Fraxidin hexoside, Pinoresinol dihexoside, Calceolarioside A, Calceolarioside B. We also found obvious increases in specific compounds (of the 20 compounds we reanalyzed in the four ash species) in Green ash, Chinese ash and Manchurian ash in the MeJA treated group. Also, Canonical Discriminant Function Analysis of five common compounds (Tyrosol Hexoside, Mandshurin, Pinoresinol compound, Syringaresinol and Oleuropein) revealed that Manchurian ash was different from the other three ashes, but closer to G (open full item for complete abstract)

Committee: Don Cipollini PhD (Advisor); Thomas Rooney PhD (Committee Member); John Stireman PhD (Committee Member) Subjects: Biology

Master of Science (MS), Bowling Green State University, 2023, Biological Sciences

Fraxinus ash trees in North America a threatended by the invasive Agrilus planipennis, emerald ash borer (EAB). EAB infestation has wide ranging economic, cultural and ecological impacts upon the North American environment. This study aims to look at the biological impact that infestation of ash trees can have on the soil microbiome around the tree's roots. A previous study has already examined the possible geochemical effects of the trees sampled, and by looking at the effects on the microbiome through 16S ribosomal sequencing, we hoped to gain some estimation of the effect imposed on microbiota surrounding the tree. With a combination of alpha, beta, and network analysis, we can see some possible changes within the rhizosphere associated to the health of trees. Alpha diversity was inconclusive as there was inconsistent data amongst our sampled set of trees. There is confounding points in the data pertaining to geographic differences in sample locations. However, when stratifying to sample locations, beta and network analyses show shifts in the microbiome are significant, with site 2 and 4 beta diversity showing a progression of microbiome makeup to change as health state changed. Differential networks between health states indicate a change in taxa between healthy and unhealthy tree rhizopheres exist. The network topography as well as the strength of edges between networks showed a difference in taxonomic makeup comparing health states with some phyla of note being Verrucomicrobia, Nitrospirae, and Acidobacteria. Because our sample size within each location was small, we recommend further studies be done to explore those differences.

Committee: Zhaohui Xu Ph.D. (Committee Chair); Jungfeng Shang Ph.D. (Committee Member); Angelica Vazquez Ortega Ph.D. (Committee Member) Subjects: Bioinformatics; Biology; Microbiology

Master of Science in Biological Sciences, Youngstown State University, 2023, Department of Biological Sciences and Chemistry

Since the discovery of the emerald ash borer (Agrilus planipennis, Coleoptera: Buprestidae) in 2002, it has caused near 100% mortality of North American ash trees (genus Fraxinus). Moreover, uncertainties remain regarding the future of the forest regeneration dynamics after the introduction this prolific forest pathogen. The objectives of this study were to: 1) Assess regeneration potential of green ash (Fraxinus pennsylavnica Marsh.) on the Lake Erie and Lake Tonawanda plains in Western New York State where it was formerly one of the dominant trees; 2) Identify other native tree species that could repopulate depleted ash stands; and 3) Assess factors constraining regeneration like invasive shrub cover and deer browsing pressure. In 32 plots (400 – 3600 m2), proportion of ash trees in c. 2010 pre-ash-borer stands was catalogued (including dead or fallen stems), and all ash trees were assigned into health categories ranging from dead to unimpacted. Stump sprout and seedling recruits were recorded. Canopy and understory stems of all other trees were identified and measured (diameter at breast height). Identity and coverage of invasive shrubs were recorded. Data were analyzed and interpreted along gradients in two important independent variables: 1) stand age at ash borer invasion (from increment counts of fallen dead ash trees, or estimated from aerial imagery), and 2) % of ash in pre-ash-borer stands. Most adult ashes within plots were dead, and with no association with stand age or pre-ash-borer ash dominance. However, 11% of ash trees were completely un-impacted, but were <5 cm diameter and concentrated in young (<60 y) ash-dominated (>80%) stands. Stump sprouting was present in 78% of plots, and ash seedlings were noted at most sites, again primarily in young ash-dominated stands. Red and/or silver maples and American elms were the most common native trees and were most important in older less ash-dominated stands. Unfortunately, invasive shrubs were often very a (open full item for complete abstract)

Committee: Thomas Diggins PhD (Advisor); Ian Renne PhD (Committee Member); Felicia Armstrong PhD (Committee Member) Subjects: Biology; Macroecology; Plant Biology

Master of Science (MS), Bowling Green State University, 2020, Geology

The impact of Emerald Ash Borer infestation on Fraxinus trees in eastern North America has been extensively studied, yet impacts to the soil health as the infestation progresses are not well understood. This study characterized soil samples from 5 health categories of Ash (Category 1: healthy; Category 5: dead) in 4 wooded upland sites in Northwest Ohio to gain a current assessment of soil health on locations with similar soil characteristics and geographic factors. Results indicated a strong positive relationship between canopy openness and health categorization (towards decline tree health). However, only a moderate negative relationship between humification index (degree of aromaticity) and canopy openness, indicating less aromatic soil organic matter beneath infested Ash trees. This suggests leaf litter from formation of epicormic branching may be replenishing or maintaining solid organic carbon stocks in soil even after the tree reaches category 4. Density of epicormic branching may also affect trends in bioavailable total nitrogen (TN) and dissolved organic carbon stocks (DOC: TN). The DOC: N ratio combined with a pattern of decrease and increase exhibited individually by DOC and TN, suggests leaf litter supply to the soil was directly affected by loss of canopy and epicormic branching. This feedback system was more visible in soil testing by the presence of neutral to slightly alkaline pH, which may be facilitating nitrification, maintaining low DOC: N ratios and increasing sensitivity to leaf litter fluxes. The neutral to slightly alkaline pH was most likely the result of high calcium (Ca) concentrations on all 4 sites. Results suggested that Ca concentrations were unaffected by base cation leaching, indicating external influxes of Ca. This study suggests Ash trees on these sites may be lingering at category 3 to 4 for several years with epicormic branching making significant contributions to soil fertility even at category 4. Results from category 4 and 5 o (open full item for complete abstract)

Committee: Angélica Vázquez-Ortega Dr. (Advisor); Nathan Hensley Dr. (Committee Member); Jeff Snyder Dr. (Committee Member); Zhaohiu Xu Dr. (Committee Member) Subjects: Biogeochemistry; Environmental Science; Forestry; Geochemistry; Geology; Organic Chemistry; Soil Sciences; Sustainability

Master of Science in Botany, Miami University, 2019, Biology

The study of the rapid decline of ash trees caused by the emerald ash borer beetle (EAB) has been well documented, but little is known about the decline of ash stands when a subset of trees is treated with insecticide. The treatment of a subset of ash trees in areas may provide protection to those ash trees that are untreated, resulting in the associational protection of untreated ash trees provided by treated ash trees. Two objectives of this study were to test whether such associational protection can occur, and the threshold, if any, at which associational protection occurs. The third objective was to test whether any ensuing mortality depended on the density of ash trees. This study was conducted in the Allegheny National Forest, located in Northwestern Pennsylvania and is part of a larger study by the U.S. Forest Service focused on preserving the genetic diversity of ash trees in the Allegheny National Forest. My analyses indicate no protection from insecticide and no associational protection. Further, I found that low ash density forest stands display faster rates of decline caused by EAB than high ash density forest stands. These findings are from the analyses of datasets from the first two years of a ten-year study and although they are from the early stages of a long-term study, the management implications are valuable.

Committee: Martin Stevens Dr. (Advisor); Vincent Michael Dr. (Committee Member); Moore Richard Dr. (Committee Member) Subjects: Botany; Ecology

Master of Fine Arts, The Ohio State University, 2019, Art

How are institutions processed through individual human beings? How do they intersect and permeate human bodies? What is the effect of institutions on the individual and how does the individual in turn affect social structures? My work investigates the physical, psychogenic, and material interchanges between social institutions and personhood. Repetition, landscape, and organic materials play reoccurring roles in my work as I explore complex socially-constructed systems and the imbalanced relationship between institutions and the individual. Through my most recent bodies of work, Collected and Early Winter, I make visible the movement of time and family through physical bodies. I employ ash trees and menstrual blood as both material and subject in works of sculpture, painting, photography, and poetry.

Committee: Jared Thorne (Committee Chair); Alison Crocetta (Committee Member); Gina Osterloh (Committee Member) Subjects: Fine Arts

Bachelor of Science (BS), Ohio University, 2017, Environmental and Plant Biology

Populations of North American ash (Fraxinus sp.) are declining due to the introduction of emerald ash borer (EAB; Agrilus planipennis), a wood-boring beetle native to East Asia. At Oak Openings Preserve Metropark in northwest Ohio, a population of green ash (F. pennsylvanica) exists in which 99% of the trees have succumbed to emerald ash borer, but a small number of trees have remained healthy. These “lingering” ash may be closely related, thus sharing common alleles that may be contributing to EAB resistance. However, relatedness may also indicate an overall lack of genetic diversity in the lingering ash relative to the former intact population. To compare genetic diversity, 39 individuals were sampled from the lingering population as well as from 19 individuals that declined significantly or suffered above-ground mortality due to EAB infestation, but developed stump sprouts. This essentially creates a temporal sampling of the population, with the susceptible and lingering samples allowing estimation of the gene pool pre- and post-EAB arrival, respectively. Genotyping of trees at 12 EST-SSR loci revealed similar levels of allelic diversity and heterozygosity between the two groups. In addition, relatedness was not significantly higher among post-EAB trees (p>0.05), but a spatial autocorrelation analysis revealed that genetically similar trees were clustering close together in geographic space. These results suggest that green ash are buffering population loss and maintaining genetic diversity, probably through life history characteristics (e.g. dioecy, wind-pollination). Knowledge of the lingering ash's genotypes will aid any breeding efforts undertaken by the US Forest Service to preserve ash on the North American landscape.

Committee: Harvey Ballard (Advisor) Subjects: Conservation; Ecology; Genetics; Plant Biology

Doctor of Philosophy, The Ohio State University, 2017, Entomology

Emerald ash borer (EAB) has killed millions of trees since its accidental introduction to southeastern Michigan more than 20 years ago. Near the invasion epicenter, nearly all mature ashes have died, reproduction has ceased, and the seed bank depleted, leaving an “orphaned” cohort of established seedlings and saplings. Because of high seedling mortality, it is possible that seedlings that established recently may have lower genetic variation than those that established before the EAB invasion. Insecticides can successfully protect ash trees from EAB and clusters of treated ash trees may slow ash mortality by reducing EAB densities. Therefore, insecticides, in high enough densities, may protect ash trees in order to maintain reproduction, regeneration, and genetic variation. I tested these questions at Five Rivers Metroparks in southwestern Ohio and the Upper Huron River Watershed in southeastern Michigan. From 2014 – 2016, green and white ash mortality differed between parks, with survival higher at Sugarcreek, Englewood, and Germantown Metroparks (low EAB impact) than at Cox Arboretum, Taylorsville, and Twin Creek (high EAB impact). I found that survival of untreated green-white ashes increased with percentage of ash phloem area treated, but only in parks with low EAB impact. Additionally, survival of untreated trees was higher when the nearest treated ash was within 100 m, percentage of ash phloem treated was high, and EAB impact was low. However, this pattern was not observed in parks with high EAB impact. These results suggest that treating ash trees with insecticide may slow the progression of ash mortality if the program is initiated when ash mortality is still low. There were more flowering green and white ash trees (treated and untreated) in plots with higher percentage ash phloem treated. In parks with high EAB impact, seedling density was low and was not affected by insecticide treatment. In parks with low EAB impact, seedling densities increased w (open full item for complete abstract)

Committee: Daniel Herms (Advisor); Mary Gardiner (Committee Member); P. Charles Goebel (Committee Member); Andrew Michel (Committee Member) Subjects: Ecology; Entomology

MS, University of Cincinnati, 2013, Engineering and Applied Science: Mechanical Engineering

Instrumental Neutron Activation Analysis (INAA) was used to evaluate the elemental composition of ash samples collected from the baghouse, electro-static precipitator, and multi-cyclone separator at the steam generation plant at the University of Cincinnati. Twenty-seven individual quantifiable elements were found in the samples including samples of crushed coal. The concentrations of elements were reported according to sample type and classified into three groups: class 1 elements [Al, Fe, Hf, K, Mn, Ni, Ta, Tb, Th, and U] were those that were equally dispersed between fly and bottom ash, class 2 elements [Ba, Cr, Sb, Se, V, and Zn] were enriched in fly ash, class 3 elements [Ce, Cs, Co, Eu, Na, Rb, Sc, Ti, Yb, and Zr] were distributed randomly between class 1 and class 2 elements. Scanning electron microscopy was used to evaluate the size of more than 2700 particles collected from the baghouse, electro-static precipitator and multi-cyclone as well as bottom ash. Particles from the electro-static precipitator exhibited the smallest average particle size [9 µm] followed by the baghouse [13 µm]. Elements collected by the electro-static precipitator included Ag, Cr, Sb, Se and V, which are among the smallest particles. However, particle size within the flue gas stream is greatly affected by the volatility of the element, so that the elemental composition of particles collected at different stages in the flue gas stream will vary based upon the type of engineering controls used to reduce emissions. Thus, samples of ash collected for nuclear forensics analysis to detect undisclosed processes involving nuclear and radiological materials will contain different elements depending upon the type of engineering controls used to reduce emissions.

Committee: Henry Spitz Ph.D. (Committee Chair); Sam Glover Ph.D. (Committee Member); Milind Jog Ph.D. (Committee Member) Subjects: Mechanics

Master of Science, The Ohio State University, 2013, Entomology

Emerald Ash Borer (EAB) (Agrilus planipennis Fairmare) is an exotic invader in North American forests. The buprestid wood borer has killed millions of ash trees since its discovery in southeastern Michigan in 2002. Because North American ash trees lack an evolutionary history with EAB, it has the potential to functionally extirpate the genus Fraxinus from the North American continent. Widespread, simultaneous ash mortality is likely to initiate a cascade of direct and indirect ecological effects. Forest infestation by EAB and subsequent loss of ash trees may lead to altered habitat and food availability for native insectivores such as birds. The objectives of this research were to: (1) determine utilization of EAB as a food resource by non-migratory bark-gleaning birds, (2) quantify forest regeneration in response to EAB-induced ash tree mortality and (3) determine the impact of EAB-induced regeneration on forest bird communities. Bird/vegetation monitoring plots were established during the winters of 2011 and 2012 in 51 forested stands throughout agricultural western and central Ohio as well as along the Huron river watershed in southeastern Michigan. During the spring of 2011 and 2012, point counts were conducted at each of the three plots per site. Bird species richness, evenness and diversity were calculated for all sites based on their stage of ash tree decline as were specific indicator species. Relative abundance was calculated for common species. Following completion of spring point counts, percent cover and composition (ie. species, native or invasive) in the overstory, understory, shrub and herbaceous groundcover layers were assessed. Importance values were calculated for tree species. Ash trees were closely inspected for signs of EAB infestation and each was assigned a rating based upon the degree of EAB-induced decline. Observations of bark-gleaning birds were conducted at each of the 51 forests during the springs of 2011 and 2012 and the winters of 20 (open full item for complete abstract)

Committee: Daniel Herms PhD (Advisor); Mary Gardiner PhD (Committee Member); Kathleen Knight PhD (Committee Member); Amanda Rodewald PhD (Committee Member) Subjects: Ecology; Entomology

Master of Science, The Ohio State University, 2011, Entomology

Ash trees (Fraxinus spp.) are widely spread throughout eastern North America and represent an important tree species in urban landscape and natural settings. Since the accidental introduction of the invasive insect pest emerald ash borer (Agrilus planipennis Fairmaire) millions of ash trees have been killed by this devastating pest. North American species such as black (F. nigra), white (F. americana), green (F. pennsylvanica), and to some extent blue (F. quadrangulata) are susceptible to this pest. However, in Asia, A. planipennis' natural habitat, the damage to native ash is isolated and only observed in trees under stressed conditions, indicating some level of resistance, presumably due to a shared co-evolutionary history. To date various efforts to contain A. planipennis have been implemented, yet it continues to spread at an alarming rate within the US and Canada. Despite the high impact status of A. planipennis, there is little information available at the molecular level for any Fraxinus species. The main objective of this study was to characterize the transcriptome of ash phloem including North American and Manchurian species, which would then lay the foundation for future functional and applied studies. The first part of the study was to describe the phloem transcriptome and predict potential molecular markers using 454 pyrosequencing. A database of more than 50,000 sequences was obtained from a pooled sample of black, green, white, blue and Manchurian ash. The database was profiled using Blast2GO software in order to annotate the sequences, determine gene ontology (GO), and identify associated metabolic pathways. Also, the expression of eight candidate genes was quantified using real time quantitative PCR (RTqPCR) in three ash species: black, green and Manchurian ash. Finally, more than 1,272 single nucleotide polymorphisms (SNPs) and 980 microsatellites were predicted. The information obtained from the first part of the study was used to carry out the (open full item for complete abstract)

Committee: Omprakash Mittapalli PhD (Advisor); Daniel Herms PhD (Committee Member); Pierluigi Bonello PhD (Committee Member) Subjects: Entomology; Forestry; Molecular Biology; Plant Sciences

Doctor of Philosophy (PhD), Ohio University, 2006, Civil Engineering (Engineering)

The disposal of fly ash (particularly class F fly ash) is increasingly becoming a problem, and the way to solve this problem safely and economically is by utilization. Due to the unique behavior of fly ashes, it has not been widely used in soil modification applications. To improve or increase fly ash utilization, this study seeks to develop a generalized theory that can adequately predict the behavior of fly ash modified soils and to quantify the uncertainties in the behavior of the ash, which hinders its wide application in soil modification. For this study, laboratory tests were performed on mixtures made from three different fly ashes of different chemical compositions. The laboratory tests were designed such that all the necessary properties needed for the analyses were addressed as well as data gaps observed in the literature. The laboratory testing provided engineering (index, deformation, and strength) properties and the necessary physicochemical properties of mixtures at various fly ash percentages for all the mixtures were determined. Three mixture theory models were used to predict engineering properties based on the properties of individual constituents. The predictive accuracies of three models were assessed, and the model that best predicted actual results was selected for modification. The need for modification is because of deviations in the model predictions. The selected model was that of Voigt (1889). Upon physicochemical analysis, it was observed that the chemical composition of the fly ashes play a significant role in the behavior of the modified soils, particularly that of calcium oxide (CaO). A relationship was found between CaO and the sum of oxides (SiO2+Al2O3+Fe2O3) in the fly ashes. As a result, the selected model was modified based on the two chemical components (CaO and the sum of oxides) of the fly ashes. A modification term ( ) was defined as a ratio between the CaO and the sum of oxides raised to an experimental index (x). The term va (open full item for complete abstract)

Committee: Sebastian Bryson (Advisor) Subjects:

PHD, Kent State University, 2010, College of Arts and Sciences / Department of Biological Sciences

The introduction of exotic species is the inevitable consequence of an expanding global society that relies heavily on international trade of goods and services. These introduced species have negative effects on biodiversity and disrupt native communities. In fact, the spread of non-native species is the second greatest threat to the loss of biodiversity next to habitat destruction. The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Buprestidae), is a recent example of an exotic forest pest species. EAB completes its life cycle on ash trees (Fraxinus spp.) including larvae feeding on cambium tissue which interferes with water and nutrient translocation. Once ash trees become infested with EAB, mortality is >99%. This dissertation was initiated after EAB was discovered and attempts to understand how EAB affects long-term forest community dynamics in order to provide practical applied conservation strategies. These research projects are designed to identify the ecological impacts of EAB and to determine long-term community changes to native deciduous forests. The research objectives are: (1) to identify consequences of EAB eradication efforts, (2) to determine altered community composition under different disturbance intensities (tree removal management recommendations) and (3) to design effective ex situ conservation protocols for future ash tree preservation. EAB causes a disturbance to native forest by creating large light gaps through ash tree dieback; yet, EAB eradication efforts magnified the scale of disturbance through time and space which facilitated the establishment of invasive plant species. The tracked vehicles used during eradication also caused significant soil compaction. Management efforts applied to EAB-infested forests should prioritize appropriate tree removal techniques to minimize the disturbance to the surrounding community. Ash stands in close proximity to roads or edges, or near established invasive populations may benefit from (open full item for complete abstract)

Committee: Oscar Rocha PhD (Advisor); Andrea Case PhD (Committee Member); Daniel Herms PhD (Committee Member); Marilyn Norconk PhD (Committee Member); Alison Smith PhD (Committee Member) Subjects: Biology; Botany; Ecology; Environmental Management; Forestry; Molecular Biology; Plant Biology

Master of Science (MS), Wright State University, 2024, Biological Sciences

Emerald ash borer (EAB), Agrilus planipennis, is an invasive pest that significantly impacts olive trees (Olea europaea). This study aimed to assess the role of abiotic stress factors such as drought and salinity in influencing plant defenses and resistance to EAB, while also examining cultivar variation in resistance. The study specifically aimed to address: (1) What effects do varying degrees of abiotic stress (drought, salinity) have on olive trees' antioxidant and peroxidase activity in olive tree? (2) Do distinct olive cultivars exhibit varying levels of resistance to EAB under various stressors? We used a controlled experimental design with two stress treatments (drought and salinity) and 20 olive cultivars to conduct the bioassay. Growth metrics (height and stem diameter), peroxidase activity, and antioxidant activity were measured, while EAB survival and performance were assessed by monitoring larval feeding and growth. Results indicated no significant differences in antioxidant activity between treatments, although low salinity slightly enhanced antioxidant responses. Peroxidase activity was highest under high salinity, and growth responses varied by treatment and cultivar, with Leccino showing the highest antioxidant activity. EAB larvae performed best under drought conditions but exhibited poor survival on certain cultivars. These findings suggest that abiotic stress influences both plant defense mechanisms and pest resistance, with cultivar-specific responses to stress and pest pressure.

Committee: Don Cipollini Ph.D. (Advisor); John Stireman III Ph.D. (Committee Member); Volker Bahn Ph.D. (Committee Member) Subjects: Agriculture; Agronomy; Biology; Botany; Chemistry; Ecology; Entomology; Environmental Science; Environmental Studies; Nutrition; Plant Biology; Plant Pathology; Plant Sciences; Public Health; Soil Sciences

Master of Science, The Ohio State University, 2007, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1921, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1933, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2024, Food, Agricultural and Biological Engineering

This thesis discusses the use of fly ash particles coated by sulfurized vegetable oil created by our colleagues at the University of Illinois Urbana-Champaign to greatly increase the hydrophobicity of the material as partial replacement of carbon black in Hevea natural rubber composites. Composites created with surface modified fly ash retained their tensile strengths and crosslink densities up to 20 wt% replacement of carbon black, while composites created with unmodified fly ash only retained their physical properties up to 10 wt% replacement of carbon black. The partial replacement of petroleum-based carbon black in rubber-based products with fly ash would increase the sustainability of the rubber industry while simultaneously reducing the overall cost by using a waste-derived filler. The thesis will also discuss a micro-compounding procedure that was adopted from a saturated polyisobutylene-based thermoplastic elastomer to effectively compound, cure, and test natural rubber compounds with a polymer mass less than 10 grams. Based on tensile tests and crosslink density measurement using solvent swelling, this micro-compounding method was found to be comparable to conventional macro-compounding for use in laboratory settings when testing commercial Hevea and semicommercial guayule control polymers. Comparative tests of greenhouse guayule rubbers were also carried out.

Committee: Judit Puskas (Advisor); Gonul Kaletunc (Committee Member); Ajay Shah (Committee Member); Katrina Cornish (Advisor) Subjects: Engineering

Master of Science, The Ohio State University, 2023, Aerospace Engineering

In this thesis there are two main studies. The first is an assessment of the role of mineral composition for Air Force Research Laboratory Test Dust (AFRL) for deposition in a realistic gas turbine engine environment. The second is an attempt to recreate Arizona Road Dust (ARD) synthetically by analyzing the chemical components of the natural dust and blending synthetic minerals together to match it. In the first study, experiments were performed on an effusion cooling test article with a coolant flow temperature of 894K and surface temperature of 1144K. Aerosolized dust with a 0-10 µm particle size distribution was delivered to the test article. The mineral recipe of AFRL was altered such that the presence of each of the five components ranged from 0% to 100%. For each of these AFRL recipe experiments several results were reported including capture efficiency, hole capture efficiency, mass flow reduction per gram, and normalized deposit height. Results are compared to a previous study of the inter-mineral synergies in an impingement cooling jet at the same temperature conditions. Despite differences in experimental facility flow geometry, overall agreement was found between the trends in deposition behavior of the dust blends. The strong deposition effects that were observed were shown to be related to adhesion forces of particles, mechanical properties, and chemical properties of the dust minerals. In the second study, X-Ray Diffraction (XRD) was performed on ARD to identify minerals present in a naturally sourced dust blend. Pure minerals were mixed in quantities that matched the XRD spectrum of ARD, and oxide content of this synthetic dust blend was shown to match the ISO standard (12103-1) to which ARD conforms. Particle size distribution was also matched to ARD (0-15 µm). Experiments were then conducted in four deposition facilities, one of which was representative of turbine hot section conditions (1500-1625K) and two were representative of internal coola (open full item for complete abstract)

Committee: Datta Gaitonde (Committee Member); Jeffrey Bons (Advisor) Subjects: Aerospace Engineering

PHD, Kent State University, 2022, College of Arts and Sciences / Department of Earth Sciences

This dissertation contains 6 chapters which examine the effects of volcanic ash deposition on paleoenvironment, sedimentology, fossil preservation, and paleoecology. It includes field-based research and experimental data which demonstrate that volcanic ash deposition can play an important role in shaping the nature of the sedimentary and fossil records in marine settings at both distal and proximal localities. Chapters 1 and 2- Summary and introduction. Chapter 3 – This chapter discusses two Cenozoic marginal marine settings which occur proximal (within 100 km) to prominent volcanic centers; one in the Pacific Northwestern United States, and one in the south of the Patagonian Cordillera, Argentina. The Oligocene Lincoln Creek Formation in Washington contains an exceptionally well-preserved marine fauna dominated by crustaceans and mollusks, and the late Miocene-early Oligocene Estancia 25 de Mayo Formation in southern Patagonia, Argentina, contains a similar exceptionally preserved fauna. In both settings, evidence shows that exceptional fossil preservation was facilitated by the deposition of mass quantities of volcanic ash via marine hyperpycnal flows following large volcanic eruptions. Chapter 4 – As discussed in the previous chapter, volcanic sediments can facilitate exceptional fossil preservation. The rapid deposition of fine-grained material in marine settings can preserve fossil material which may otherwise not be preserved. One such example of preservation in volcanic ash is a new species of isopod from the above-described Estancia 25 de Mayo Formation. In this chapter, Cirolana centinelensis n. sp. is described as the first known occurrence of the Isopoda in the fossil record of Argentina. The chapter discusses the recalcitrance of fossil isopods with respect to preservation and elucidates how the rapid deposition of volcanic ash facilitated the preservation of this exceptionally rare fossil specimen. Also discussed are the vagaries of the f (open full item for complete abstract)

Committee: Rodney Feldmann (Advisor); Carrie Schweitzer (Committee Co-Chair); Silvio Casadio (Committee Member); Joseph Ortiz (Committee Member) Subjects: Geology; Paleoecology; Paleontology