Master of Science, The Ohio State University, 2016, Civil Engineering

Fractured shale formations that are depleted of natural gas could be attractive targets for geologic carbon dioxide (CO2) storage. These formations have large capacity and existing infrastructure, which can be repurposed for injection, but they are not as geographically widespread as saline aquifers, a more common repository for CO2 storage. To examine the geospatial and economic viability of CO2 storage in fractured shale formations compared to storage in saline aquifers, estimates were calculated for the storage capacities and costs associated with storing CO2 in depleted shale formations and saline aquifers in Ohio, Pennsylvania, and West Virginia using the Tao and Clarens (2013), NATCARB, and CO2-PENS models. These estimates were then used in the engineering-economic geospatial optimization model for CO2 capture and storage SimCCS (Scalable infrastructure model for CO2 Capture and Storage). The average cost of CO2 storage in shale formations was found to be cheaper than in CO2 storage in saline aquifers by $5-10/tCO2 (10-15%) on average, due, in part, to smaller estimated Areas of Review and assumed repurposing of well infrastructure. Based on the results of the SimCCS, in this region CO2 storage in shale formations can be more centralized, occur in fewer sites, require less pipeline infrastructure, and have lower system-wide costs than if equivalent amounts of CO2 were stored in saline aquifers. System-wide costs could be reduced another 10-30% by sequestering the entire flue gas in shale formations. Common pipeline routes are deployed for CCS networks using either saline aquifers or fractured shale formations for storage and across various CO2 storage rates or CO2 prices, indicating that a robust network could be built that could serve many different storage scenarios. The results suggest that CO2 storage in fractured shale is attractive in regions with abundant shale gas development for both technical and economic reasons due to the lower storage costs and (open full item for complete abstract)

Committee: Jeffrey Bielicki (Advisor); Mark McCord (Committee Member); Gajan Sivandran (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy, The Ohio State University, 2023, Molecular Genetics

The c-type cytochromes or cytochromes c are heme-containing metalloproteins that act as electron carriers in energy transducing membranes involved in processes such as photosynthesis and respiration. The maturation of cytochromes c requires covalent attachment of the heme cofactor to a heme-binding motif (CXXCH)in the apocytochrome c. In chloroplasts, cytochrome c assembly depends on factors known as CCS (Cytochrome c Synthesis), that are essential for the heme attachment reaction taking place in the thylakoid lumen The covalent attachment of heme requires the heme-linking cysteines of apocytochrome c to be maintained in a reduced state (providing free -SH) by the operation of a trans-thylakoid disulfide reducing pathway. CCDA, a polytopic thylakoid membrane oxido-reductase, and CCS5, a thioredoxin-like protein, are two components of a trans-thylakoid disulfide-reducing pathway, which also operates in bacteria This pathway transfers electrons from stroma via signature redox motifs and sequential thiol-disulfide exchanges from CCDA to CCS5 to reduce apocytochrome c disulfide bonded CXXCH in the thylakoid lumen. CCS4, first identified in the unicellular alga Chlamydomonas reinhardtii, is a thylakoid-bound stroma-facing component of this disulfide-reducing pathway with no residue or motif suggestive of a biochemical activity. A ccs4 mutant is partially deficient for photosynthesis (due to a defect in cytochrome c assembly) and can be rescued by application of exogenous thiols or overexpression of CCDA. In this work, we evidenced that CCDA accumulation is decreased in a ccs4 mutant but not in a ccs5 mutant, suggesting a functional interaction between CCS4 and CCDA. Our genetic studies show that CCS4 and CCS5 are partially redundant for the delivery of reducing power for the apocytochrome c CXXCH reduction. We also show that gain-of-function mutations in the CCS4 gene that correspond to changes in the stromal domain of the protein can suppress a ccs5-null mutant. This su (open full item for complete abstract)

Committee: Patrice Hamel Dr. (Advisor); Natacha Ruiz Dr. (Committee Member); Amanda Bird Dr. (Committee Member); Iris Meier Dr. (Committee Member) Subjects: Biochemistry; Genetics; Microbiology; Molecular Biology

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

As universities within the United States continue to compete for students and resources, there is increasing pressure for these institutions to maximize the enrollment of students per classroom. Evidence exists that higher-enrollment classrooms can have negative effects on the students who are exposed to them, with students in higher-enrollment classrooms displaying decreases in engagement, persistence, and sense of belonging (MacGregor, 2000). In this paper, the analysis of survey, observational, and demographic data, that was collected from BGSU students enrolled in multiple gateway STEM courses (3278 Students; 41 Classrooms), is described. The purpose of this research is to better understand how the implementation of the BGSU Learning Assistant (LA) Program in these courses impacts course structure as well as student perceptions of belonging and their academic success. The results indicate that classes with Learning Assistants (LAs) present spend a lower percentage of time engaged in exposition-centered teaching styles (i.e. lecture) and a greater percentage of time engaged in constructivist teaching modes, during which students have the opportunity to take a more active role in discussing and refining their thoughts and understanding of the course concepts. Data also indicate that students in these transformed classroom environments report an increase in their sense of community, as measured using the Classroom Community Scale (Rovai, 2002), and students in classes with LAs present are retained at a higher rate than students in classes without LAs. Correlations between class instructional profiles, student perceptions of classroom community, and retention are analyzed in order to better understand how these variables relate to one another, in order to gain a clearer understanding of how LAs are able to impact the students in their classes. Results indicate that at least some of the increase in community and retention can be explained by the positive influences o (open full item for complete abstract)

Committee: Karen Sirum (Advisor); Julia Matuga (Committee Member); Kevin McCluney (Committee Member) Subjects: Science Education

Doctor of Philosophy, The Ohio State University, 2019, Environmental Science

Reducing carbon dioxide (CO2) emissions is one of the most pressing issues facing the electricity system. Towards this end, prior work investigated generating electricity with geologically stored CO2 by using it to extract heat from sedimentary basins geothermal resources. This dissertation expands on this idea by developing and valuing approaches for CO2-based energy storage. In the first chapter, we investigate the value that three bulk energy storage (BES) approaches have for reducing system-wide CO2 emissions and water requirements: CO2-Bulk Energy Storage (CO2-BES), which is a CO2-based energy storage approach that uses a concentric-ring, pressure based (CRP-BES) design, Pumped Hydro Energy Storage (PHES), and Compressed Air Energy Storage (CAES). Our results suggest that BES could decrease system-wide CO2 emissions by increasing the utilization of wind, but it can also alter the dispatch order of regional electricity systems in other ways (e.g., increase in the utilization of natural gas power capacity and of coal power capacity, decrease in the utilization of nuclear power capacity). While some changes provide negative value (e.g., decrease in nuclear increased CO2 emission), the system-wide values can be greater than operating cost of BES. In the second and third chapters, we investigate two mechanisms for using CO2 for energy storage: storage of (1) pressure and (2) heat. For pressure storage, we investigated the efficacy of the CO2-BES system using the CRP-BES design over cycles of varying durations. We found that CO2-BES could time-shift up to a couple weeks of electricity, but the system cannot frequently dispatch electricity for longer durations than was stored. Also, the cycle duration does not substantially affect the power storage capacity and power output capacity if the total time spent charging, discharging, or idling is equal over a multi-year period. For thermal energy storage, we investigated the efficacy of using pre-heated CO2 and pre-h (open full item for complete abstract)

Committee: Jeffrey Bielicki (Advisor); Ramteen Sioshansi (Committee Member); Gil Bohrer (Committee Member); Brent Sohngen (Committee Member) Subjects: Alternative Energy; Energy; Engineering; Environmental Economics; Environmental Science

Master of Science, The Ohio State University, 2011, Geological Sciences

Subtle shifts in the lithology or diagenetic history of a sedimentary formation may result in different reservoir properties of that formation, by affecting porosity and permeability in varied ways. This may create a geographic heterogeneity that will alter the accuracy of reservoir storage estimations of a formation. The Mt. Simon and Rose Run Sandstones of Ohio are both established as appropriate targets for the sequestration of supercritical CO2, but each of these formations may contain heterogeneities that are heretofore unaccounted for by standard well exploration. The porosity and permeability of these formations may differ based upon their local diagenetic histories. To account for these differences, the concentrations of quartz and feldspar within these sandstones offer evidence of diagenetic processes that have occurred in the past and those that may still occur in the future. Grain-size variations and any geographic trends they show can also be used as evidence of diagenetic variations that may indicate further heterogeneities that will affect the porosity and permeability of the formation on a local level. In this study, feldspar concentrations in both the Rose Run and Mt. Simon Sandstones are studied, on a microscopic level, and are shown to be extremely low with subtle variation of concentration based on location. Grain sizes of these formations also show subtle variations based on geographic location. Both results show that further study into the locally geographic differences of these formations will be necessary in order to accurately evaluate their storage capacity.

Committee: Michael Barton Dr. (Advisor); Loren Babcock Dr. (Committee Member); David Cole Dr. (Committee Member) Subjects: Earth; Energy; Environmental Engineering; Environmental Geology; Environmental Science; Environmental Studies; Geological; Geology; Geotechnology

BA, Oberlin College, 2011, Physics and Astronomy

There are a range of environmental and industrial applications to capturing carbon dioxide from gas mixtures. Currently, materials being used in these applications bind carbon dioxide too strongly for practical purposes, such that they require large amounts of energy to be regenerated for reuse. Highly porous materials called metal-organic frameworks (MOFs) could serve much more effectively as carbon-capturing materials, as they suck up large amounts of carbon dioxide gas at pressures and temperatures that are nearly ideal for carbon-capture applications. Moreover, they require much less energy than current materials to release the carbon dioxide and be regenerated. Additionally, many different structures can be created fairly easily, so scientists are on the hunt for the ideal carbon-capturing MOF. In this thesis we study Mg-MOF-74, a particularly promising metal-organic framework material for separating carbon dioxide from gas mixtures. We use infrared spectroscopy to probe the interactions between the Mg-MOF-74 host and both carbon dioxide and methane. By shining infrared radiation on Mg-MOF-74 with gases trapped in it and looking at which frequencies of radiation are absorbed by the bound gases, we can learn about the binding nature of the framework. This in turn helps us to better understand the properties are are preferable in metal organic frameworks, and will aid chemists in fabricating new structures that are ideal for carbon-capture and other applications.

Committee: Stephen FitzGerald PhD (Advisor) Subjects: Molecular Physics; Physical Chemistry; Physics