Doctor of Philosophy (Ph.D.), Bowling Green State University, 2023, Statistics

This dissertation focuses on methodological innovation for multiple testing on hypotheses related to large-scale and correlated data, where error rate control is intrinsically critical. Research toward this goal necessitates rigorous discussions on a thorny concept, the strong control of familywise error rate (FWER). In the literature, published papers in this regard subsequently avoid this intricate issue by adapting feeble criteria such as the weak control of FWER or the false discovery rate. Different from conventional approaches, we directly tackle the problem with the strong control of FWER. Starting with Efron's data on an inference problem related to 7128 genes of 72 patients, consisting of 47 acute lymphoblastic leukemia patients and 25 acute myeloid leukemia patients, the dissertation lays out fundamental terminologies facilitating the research on multiple inferences after discussing a method controlling the false discovery rate following the empirical approach of estimating the correlation parameter. Following a review of the current literature, one distinct feature of the dissertation attributes to multiple testing procedures on odds ratios when several populations are of interest. When the joint distribution of a cluster of subsequent populations is approximately available, such as the utilization of the Cochran-Mantel-Haenszel statistic, a sequential testing method of strong control of FWER is proposed. The new method outperforms the traditional Holm's procedure (which also strongly controls FWER) in terms of substantiating any signifcant discovery that is detected by the latter. Another feature of the dissertation explores the sequential testing procedure for the comparison of the odds ratio. It effectuates a general stepwise exact inference procedure that strongly controls the FWER. The new procedure is robust and versatile for both parametric and nonparametric settings. When the new procedure was employed with the Jonckheere-Terpstra test, it dist (open full item for complete abstract)

Master of Science in Chemical Engineering, Cleveland State University, 2011, Fenn College of Engineering

Dendritic single crystals of Al-7wt%Si alloy have been directionally solidified at a thermal gradient of 40 K cm-1 over growth speeds, ranging from 5 to 85 to 31µm s-1, using aluminum single crystal seed aligned along [100] crystallographic orientation. Mushy zone morphology parameters, such as, primary dendrite nearest neighbor spacing, primary dendrite trunk diameter, side (secondary dendrite) branch length and side branch orientation, have been characterized in to investigate the transients introduced by step increase and step decrease in growth speed. An increase in the growth speed shows a decrease in both nearest neighbor spacing and trunk diameter. A comparison between the two parameters suggests that the trunk-diameter may be a better metric to quantify differences due to small change in processing parameters, such as, growth in low-gravity in the absence of convection. The trend of decreasing trunk diameter with increasing growth speed is similar to the primary dendrite tip radii trend (predicted by theoretical models). Statistical analysis of the transverse microstructures after the step decrease in growth speed (from 85 to 31µm s-1) showed that primary dendrites which survive the transient are the ones with larger neighbor spacing. However, the predictive ability of nearest-neighbor distance (NNS-1), mean of four nearest neighbor distances (NNS-4) or the mean of six nearest neighbor distances (NNS-6) in terms of which dendrites are likely to dissolve-off appears to be similar. Average side-branch length of the surviving primary dendrites increases and those of the disappearing primary dendrites decreases after the growth speed decrease. Primary dendrites whose side-arms are not orthogonal are more likely to dissolve-off than those which are aligned closer to [100]. Porosity formation during directional solidification can lead to spurious grain formation which will seriously degrade the high temperature creep properties of directionally solidified compone (open full item for complete abstract)

Master of Computing and Information Systems, Youngstown State University, 0, Department of Computer Science and Information Systems

Bootstrap sampling serves as a cornerstone in statistical analysis, providing a robust method to evaluate the precision of sample-based estimators. As the landscape of data processing expands to accommodate big data, approximate query processing (AQP) emerges as a promising avenue, albeit accompanied by challenges inaccurate assessment. By leveraging bootstrap sampling, the errors of sample-based estimators in AQP can be effectively evaluated. However, the implementation of bootstrap sampling encounters obstacles, particularly in the computation-intensive resampling procedure. This thesis embarks on an exploration of various resampling methods, scrutinizing five distinct approaches: On Demand Materialization (ODM) Method, Conditional Binomial Method (CBM), Naive Method, Two-Step Poisson Random (TSPR), and Two-Step Poisson Adaptive (TSPA). Through rigorous evaluation and comparison of the execution time for each method, this thesis elucidates their relative efficiencies and contributions to AQP analyses within the realm of big data processing. Furthermore, this research contributes to the broader understanding of resampling techniques in statistical analysis, offering insights into their computational complexities and implications for big data analytics. By addressing the challenges posed by AQP in the context of bootstrap sampling, this thesis seeks to advance methodologies for accurate assessment in the era of big data processing.

Doctor of Philosophy, University of Toledo, 2022, Physics

Photovoltaic (PV) devices, also commonly known as solar cells, are a very promising renewable energy technology. Recently, thin film solar cells based on hybrid organic-inorganic perovskites (HOIPs) have become highly attractive due to a high solar power conversion efficiency (PCE) that has reached 25%. The high efficiency of perovskite hybrid solar cells is due to material's unique properties such as direct band gap, high absorption coefficient, small exciton binding energy, long charge carriers' and diffusion length. The high efficiencies achieved in these solar cells are already on par with those made from multicrystalline silicon, CIGS, and CdTe, all of which are usually fabricated using high vacuum and high temperature methods which increase production costs and impede application on many flexible substrates. In comparison, HOIPs reduced production costs because of their low-temperature solution processability. This thesis addresses several significant issues that are critical to advancing HOIPs from the lab to the manufacturing environment. Such as enhance grains grow of perovskite film, and deposit large area of perovskite film using low-cost blade-coating technique. Inhomogeneity and decomposition processing in a variety of perovskite solar cells has been investigated using fast EL imaging. Obtaining large grain size and high crystallinity in absorber materials play an important role in fabrication of high-performance methylammonium lead iodide (MAPbI3) perovskite solar cells. Here we studied the effect of adding small concentrations of Cd2+, Zn2+, and Fe2+ions to the perovskite precursor solutions normally used in the single-step solution fabrication process. Enhanced grain size and crystallinity in MAPbI3 films were obtained by using 0.1% of Cd2+ or Zn2+in the precursor solution. Consequently, solar cells constructed with Cd- and Zn-doped perovskite films show a significant improvement in device performance relative to control devices prepared without th (open full item for complete abstract)

Psy. D., Antioch University, 2021, Antioch Santa Barbara: Clinical Psychology

This literature review provides a general overview of the relative effectiveness of different treatment modalities that are available to therapists for the treatment of substance abuse. Some of these models include Cognitive Behavioral Therapy, Relapse Prevention, Mindfulness-Based Stress Reduction, Contingency Management, The 12-Step Approach, Motivational Interviewing, and Harm Reduction. While investigating the effectiveness of these treatment strategies, it was discovered that the conditions under which recovery from substance abuse are likely to occur involves several components. These concepts are common to nearly all of the evidenced-based strategies that were reviewed and include the development of coping and social skills. The promotion of self-awareness, self-efficacy, and interpersonal communication are common themes throughout the literature. This review provides meaningful data that supports the assumption that the application of evidenced-based treatment modalities positively impacts the lives of adult substance abusers and can be used effectively with a wide range of substance use disorders (Killuk, 2014). Cognitive Behavioral Therapy is currently the most widely used and researched treatment strategy. Treatments that help substance abusers gain awareness of the relationship between their thoughts, behaviors, and emotions tend to create desired outcomes. This literature review also explores the effectiveness of spirituality and religion as a part of treatment. This dissertation is available in open access at AURA (https://aura.antioch.edu/) and OhioLINK ETD Center (https://etd.ohiolink.edu).

Master of Science (MS), Ohio University, 2014, Journalism (Communication)

The purpose of this study is to examine how Chinese college students find and distribute advertising information on Renren, from a theoretic perspective of a One-Step and Two-Step Flow of Communication. The method for collecting data used an online survey questionnaire. Respondents were recruited by sending survey invitations to the researcher's friends on Renren.com, a Chinese equivalent of Facebook. This study has four main findings. First, the classic Two-step Information Flow is still the dominant pattern of advertising information flow on Renren. Second, Renren users' interest in different product types is positively correlated with their willingness to distribute information to other users. Third, Renren users' interest in entertaining and informative ads is positively correlated with their likelihood of obtaining information from instant ads and their willingness to distribute information to others. Fourth, gender and frequency of Renren use do not influence Renren users' choice of information sources about advertised products or their willingness to distribute information.

Doctor of Philosophy, The Ohio State University, 2001, Physics

Energetically and kinetically driven step formation and evolution on Si(001) and Si(111) surfaces has been investigated experimentally using scanning tunneling microscopy (STM), atomic force microscopy (AFM), optical microscopy, and low-energy electron microscopy (LEEM). Four systems are investigated: (1) Detailed STM measurements of boron-doped Si(001) surfaces is presented, along with large-scale AFM and LEEM observations of the well-known boron-induced ‘striped' phase at elevated temperatures. Boron is shown to induce a variety of related atomic-scale structures, some of which tend to decorate surface step-edges. This, in turn, could provide an explanation for the observed boron-induced reduction in step formation energy. However, the observed boron-accumulation at step-edges does not appear to vary systematically with annealing temperature, leaving the well-known temperature dependence of the striped phase unresolved. Real-time LEEM observations of striped step formation on Si(001) during diborane (B2H6) exposure at elevated temperatures are used to demonstrate the controlled formation of large (>5 mm) surface regions with highly uniform striped step structures. (2) Large-scale step rearrangements have been investigated on Si(001) and Si(111) surfaces heated to sublimation temperatures (>900 °C) using a direct current. These surfaces undergo dramatic morphological changes, which are believed to arise from a directional drift of diffusing surface atoms in the presence of an applied electric field. Such ‘electromigration' phenomena include step ‘bunching' and step ‘wandering', as well as a predicted step ‘bending' instability. Using AFM and optical microscopy, we argue that the direction of surface atom electromigration on Si(001) can be parallel, anti-parallel, or even sideways to the applied electric field, depending on the direction of the applied field with the high-symmetry <110> crystal directions. In addition, the first experimental evidence for the predi (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2006, Physics

Understanding the processes that govern the motion and arrangement of steps on vicinal semiconductor surfaces been a long-standing problem of great scientific interest. From a technological view point, understanding the behavior of surface steps is very important for semiconductor device processing. Recently there has been great interest in processes that lead to the spontaneous arrangement of steps into large surface structure ranging in size from a few nm up to many microns. One fascinating example of this is step bunching on slightly miscut silicon surfaces heated to high temperatures using a direct current, and although the process of step bunching on Si surfaces is well documented experimentally, it remains poorly understood. In this thesis I will report on a sequence of experiments designed to address the complex step bunching behavior observed on Si(111).

Master of Science (MS), Ohio University, 2024, Physics and Astronomy (Arts and Sciences)

The current advancement in the application of novel plasmonic materials as a result of their interaction with incident light has drawn attention and led to surging interest in many research disciplines to explore more optical properties and information of these materials. In applied plasmonic research, knowledge of the hot electron generation rates and the related ultrafast processes has become very important. To begin with, this thesis presents a detailed study of the time-resolved spectroscopy involving ultrafast processes of Au and TiN NSs. Here, we used femtosecond laser pulses for the heating and employed both one temperature and dual-parabolic two-step model to solve for the nanospheres and heat diffusion equation for the surrounding matrix in order to explain the heat transfer processes. Furthermore, we also studied the effect of chirality on the hot electron generation in some novel plasmonic structures and systems. The insight of the hot electron generation rates and maps shows the hotspots and local distribution crucial in developing costeffective and efficient devices that employ plasmonic activities. After comparing with different geometries, our results of hot electron generation in each of the nanocrystal systems considered give us information of characterization on the insight of how the chirality, of each of LCP and RCP generates hotspots of different magnitudes. Also, the different geometric settings enable us to detect which is responsible for the efficient energy conversion from the hot and enhanced regions. The simulated results showed that the helicoid dimer (with one rotated by 45◦) placed side by side and covered with DNA on a silicon substrate showed enhanced optical and hot electron responses. The experimental and computational results obtained in this study are in agreement.

Doctor of Philosophy, The Ohio State University, 2024, EDU Teaching and Learning

Abstract Using Self Study in Teach Education (S-STEP), this research examined the ways in which my utilization of Linguistic Landscape (LL) as a pedagogical tool contributed to developing teacher candidates as future educators. In doing so, this study aims to highlight the use of LL as an effective pedagogical tool for developing Critical Multilingual Language Awareness (CMLA) and curriculum development, while recognizing the role of the teacher educator in fostering that development. This study was conducted in a 16-week Instructional Planning and Advocacy for Multilingual Learners course at The Ohio State University. The main sources of data were teacher educator and teacher candidate self-reflections. A combination of thematic and axial coding was used to analyze and interpret the reflections. Findings demonstrate that working with the LL developed teacher candidates' CMLA through fostering their knowledge of languages, awareness of plurilingualism, and knowledge that language is socially created and changeable. Additionally, working with the LL developed teacher candidates' knowledge of curriculum creation and alignment. Utilizing S-STEP explored the role of the teacher educator, highlighting connection points used to transfer CMLA and curriculum knowledge to teaching contexts. S-STEP is necessary for bridging the gap between developing individual knowledge base and experience in the LL and transferring that knowledge to future classrooms.

MS, Kent State University, 2024, College of Arts and Sciences / Department of Geography

In 2018, the largest wildfire to ever occur in the Santa Monica Mountains National Recreation Area burned 88% of National Park Service (NPS) land. Located near Los Angeles, this park is the largest urban national park in the U.S. and home to mountain lions (Puma concolor) that are severely threatened. High levels of urbanization force them to live in overlapping and too small of home ranges, leading to intraspecific conflicts and inbreeding. The frequent wildfires add another threat, killing pumas directly or damaging their habitat. Current research conflicts as to how pumas select habitat post-fire, and most do not incorporate remote sensing metrics or consider how movements change with time since fire. In this study, I used global positioning system (GPS) collar data supplied by the NPS to analyze post-fire puma habitat selection. I conducted integrated step selection functions (iSSFs) at individual and population levels, for every 6-month seasonal period following the 2018 fire through 2023. I analyzed nine static variables to account for abiotic landscape variability and three variables derived from multi-temporal remote sensing to capture the dynamic, biotic environment, mainly focused on burn severity and vegetation condition and structure metrics. Habitat selection and variable importance were compared within each time period, as well as throughout the study period. I focused results on the population level analyses only. Results indicated that pumas consistently selected for increased vegetation vigor and selected for higher landscape heterogeneity and structure for the majority of time periods. Vegetation vigor also appeared as one of the most important variables to movement, along with terrain ruggedness and slope. Seasonal trends emerged for some variables post-fire. This study suggests that pumas are considerate of vegetation condition and fire impacts when selecting habitat, highlighting key habitat characteristics that pumas prefer post-fire. The influ (open full item for complete abstract)

Doctor of Philosophy, University of Toledo, 2023, Exercise Science

The repetitive nature of long-distance running contributes to high running-related injury rates in adolescent long-distance runners. Cadence (i.e., the number of steps taken per minute) is a factor that contributes to the loads applied to musculoskeletal structures. For adults, increasing cadence above a runner's self-selected step rate reduces lower extremity peak joint angles, moments, and powers, theoretically reducing the risk of sustaining a running-related injury. While cadence manipulation (i.e., increasing cadence) is a common intervention for treating injured runners, most prior studies have been conducted in adults and in laboratory settings. The potential influence of growth and motor skill development that occurs during physical maturation, as well as running in a lab environment, questions the ecological validity of generalizing results from prior studies to adolescent long-distance runners. The aim of manuscript 1 was to investigate the influence of increasing cadence on lower extremity peak joint angles, moments, and powers, and ground reaction forces for adolescent long-distance runners. We found that increasing cadence reduced peak hip, knee, and ankle angles, knee and ankle moments and powers, and ground reaction forces, but increased peak hip moments and powers. iv The aim of manuscript 2 was to investigate the influence of increasing cadence on the relative work contribution of the hip, knee, and ankle as well as the lower extremity work per step and estimated per 5 km for adolescent long-distance runners. We found that increasing cadence reduced eccentric and concentric knee work per step and per 5 km without significantly changing hip and knee work per 5 km. The aim of manuscript 3 was to investigate the influence of increasing cadence on peak joint angles and tibial acceleration as well as psychophysiological responses when running in the wild for adolescent long-distance runners. We found that increasing cadence reduced peak knee flexion bu (open full item for complete abstract)

Master of Arts (MA), Bowling Green State University, 2022, Sociology

Greater longevity increases the potential share of later life that individuals spend as a parent or grandparent (Margolis 2016; Margolis and Verdery 2019; Wachter 1997). Moreover, increases in marital instability raise the possibility that stepparents and step-grandparents may become an important role for many older adults. Although prior research has demonstrated that step-parenthood and step-grandparenthood are more common among non-Hispanic Black individuals (Yahirun, Park, and Seltzer 2018), we know less about how these roles vary across racial/ethnic groups. Using data from the 2015-2017 Add Health Parent Study (AHPS), this study examines racial/ethnic differences in step- versus biological parent support of adult children and grandchildren. Specifically, the study assesses instrumental support from parents to their adult children who are also parents, and thus offers a measure of indirect support to grandchildren. Additional analyses examine direct grandparent to grandchild support via anticipated childcare availability. Findings from this study suggest that biological parent families provide more instrumental support to adult children with activities such as childcare, errands, transportation, chores, or hands-on care in the past 12 months compared to stepparent families. Moreover, among individuals who did provide instrumental support to their adult child, the hours spent providing support were greater in biological parent families than stepparent families. However, race/ethnicity moderates the relationship between stepfamily structure and hours of instrumental support, such that the step- biological gap is smaller for Hispanic families compared to non-Hispanic White families. Furthermore, the additional analysis found that step-grandparents are less likely to anticipate helping their grandchild “a great deal” in the next 12 months. Findings from this study contribute to the broader literature on family complexity and racial/ethnic differences across kinship (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2022, Electrical and Computer Engineering

Silicon carbide (SiC) metal–oxide–semiconductor field-effect transistors (MOSFETs) greater than 1.2 kV are attractive for medium-voltage (MV) power systems. Compared to traditional silicon (Si) based systems, designs utilizing SiC devices have shown improved performance. Due to improvements in SiC technology, there has been a great investment in the research and development of SiC devices, allowing for an increase in marketshare. Today, SiC MOSFETs have already become more readily available from many device manufacturers. The ruggedness of these devices against short-circuit (SC) events is becoming one of the major concerns for market acceptance. During a SC event, the device is stressed simultaneously with high drain-source voltage and high current, leading to adiabatic heating. This could result in device failure, thus compromising system operation. Industry and transportation applications require switching devices to sustain a considerable SC time to ensure reliable protection. Therefore, it is critical to characterize the SiC devices' SC withstand time (SCWT), SC-induced degradation, and failure mechanisms. As these devices are being applied in MVDC systems, advantages like high power density and efficiency can be achieved. Circuit topologies of isolated high voltage-stepdown ratio dc/dc converters are studied. Among them, the square-wave modular multilevel converter (MMC) based topologies can have high operational flexibility to achieve voltage-step-down and frequency multiplication functions, which have significant implications for designs and applications. In a case study focusing on a 250-kW, 7-kV, MVDC energy storage system designed for improved grid resiliency, comparisons of numerical results are conducted among the MMC-based topologies. A scaled-down 10-kW prototype is presented later. The circuit parameters and failure modes are analyzed, and the design guidelines of the hardware components are introduced. This MV and medium-frequency (MF) conv (open full item for complete abstract)

PhD, University of Cincinnati, 2022, Education, Criminal Justice, and Human Services: Educational Studies

This study investigated factors that are related to student success in using and learning from written corrective feedback (WCF). Focusing on learner affective variables and a student writing corpus collected over the span of a semester, different types of feedback and errors were investigated. Previous studies have focused on one or, at the most, two variables, such as motivation, error type, corpus, instruction type, etc., but a combination of all of the different factors, such as error type, motivation, correction type, and corpus, offers a fresh perspective towards learning about student use of feedback. Using expectancy-value theory and Gass' five-step framework as guiding frameworks, this study offers a convergent mixed methods perspective to WCF through a comprehensive quantitative analysis of student writing and corpus data coupled with a qualitative outlook through analysis of student writing and corpus data feedback and student perception of it. Twenty-two undergraduate ESL students were recruited and their guided writing drafts were studied through the course of a semester. A writing prompt was analyzed with stimulated recall regarding error correction and feedback usage. Motivational testing of student motivation towards feedback and tasks were surveyed through the use of the Motivated Strategies for Learning Questionnaire (MSLQ) and analysis of concordancing and collocations of the writing samples were taken as well. Student interviews were also used to investigate student perception of feedback. The data collected both quantitatively and quantitatively was merged to create themes that helped to show that there was a connection between expectancy-value, motivation, and feedback use and that the breakdown between intake, integration, and output seems to be valid and worth further exploration.

Master of Science, The Ohio State University, 0, Electrical and Computer Engineering

The transportation sector is making a transition from conventional engine vehicles to hybrid electric vehicles because of the environmental concerns like global warming. HEVs are a very lucrative option today because it helps reduce the usage of fossil fuels without much compromise on the range of the vehicle. This is because HEVs offer extra degrees of freedom to operate the vehicle in electric mode or engine mode or both. This calls for optimizing the powertrain of a HEV. As a part of this research work, we present a more realistic approach by considering a large state-space which engenders complex dynamics/ interactions between multiple sub-systems. A P2 parallel hybrid powertrain of a class 6 Pick-up & Delivery truck is considered as the case-study problem. This problem involves 13 states and 4 control levers. Some of these variables are discrete in nature and some are continuously varying with respect to time. Some have slow dynamics like temperature, while some have fast dynamics like battery state of charge which makes it a stiff system. Usage of LUTs, interpolations and conditional formulations exacerbate the complexity of the problem already considered. Optimization of all these variables together makes it very challenging for the solver hence, a novel three-step approach is presented and used to solve the case-study problem. This makes use of pseudo spectral method (PSC) for handling real-valued variables and for accurate state estimations and Dynamic programming (DP) for the optimization of integer-valued variables. We present three scenarios for the case-study problem where fuel consumption alone is minimized, emissions alone are minimized and, lastly a combination of both fuel and emissions are minimized. The computation time for this huge problem is only of the order of 50-80 minutes using the 3-step approach. The fuel minimization case has the least fuel and highest emissions, and vice versa for the emissions minimization case. The fuel & emissions pr (open full item for complete abstract)

Doctor of Philosophy (Ph.D.), Bowling Green State University, 2021, Sociology

The majority of Americans have siblings, who provide one another with warmth, support, and friendship, and also serve as a source of conflict, throughout the life course. Past research shows that sibling relationship quality influences mental health and self-concept. Over the past several decades, as more parents break up and re-partner, a substantial proportion of America's youth grow up with half-siblings or step-siblings. Limited research has examined how sibling relationship quality with half-siblings or step-siblings differs from those with full-siblings, however. Using Waves II and III of the National Longitudinal Study of Adolescent to Adult Health, drawing from the core sample (N = 8,402) and the residential sibling pairs sample (N = 1,753), this dissertation examines the following three questions : (1) Does residential sibling relationship quality in adolescence, measured as feelings of love, fights, and time spent together, vary across full-siblings, half-siblings, and step-siblings, controlling for variation by sibling type in family characteristics, such as mother-child relationship quality, father-child relationship quality, and family belonging? (2) Does sibling relationship quality in young adulthood, measured as visits, phone calls, help-seeking, fights, and emotional closeness, vary by sibling type, controlling for sibling relationship quality during adolescence? (3) Does the association between relationship quality with residential siblings in adolescence and mental health and self-concept in young adulthood differ across the three residential sibling types? The findings suggest that among residential siblings, with the same family characteristics, relationships with step-siblings are more distant than those with full-siblings or half-siblings, while relationships with half-siblings are similar to those with full-siblings, both in adolescence iii and young adulthood. Emotionally close relationships and fights with siblings in adolescence are as (open full item for complete abstract)

Doctor of Philosophy, University of Akron, 2021, Polymer Science

In most synthetic bioresorbable polymers, changing the physical properties such as elasticity and toughness by monomers results in a change to the crystallinity of the material, which manifests through alteration of its mechanical performance. “Thiol-yne” click chemistry has been discovered as an efficient methodology for step-growth polymerization between thiols and activated alkynes. Variation of the solvent polarity and base strength results in a series of elastomers possessing a wide variation of cis stereochemistry and crystallinity resulting in wide range of elasticity and stiffness. These materials are noteworthy that they do not rely on hard block-soft block interactions for their elastic properties nor are they crosslinked, which facilitates their degradation and use in regenerative medicine applications. Significantly, the crystalline domains that form between the cis alkene units and degradable segments to provide unexpected water barrier properties while retaining the ability to be resorbed. Thus, this innovation opens the new route for developing bioresorbable elastomers that can be widely applied into tissue engineering and wireless medical bio-electronics.

PHD, Kent State University, 2021, College of Arts and Sciences / Department of Chemistry and Biochemistry

Porous carbons are promising candidates for CO2 adsorption because of high surface area, good thermal and chemical stability, easy regeneration, widely available precursors, and ability of tailoring their porous structure and surface chemistry. High CO2 adsorption capacity under atmospheric conditions is primarily governed by the volume of micropores below 1 nm. Therefore, the post-synthesis chemical or physical activations of carbons are usually applied to enhance microporosity. This process usually involves harsh chemicals (e.g., KOH and ZnCl2) and high activation temperature. In addition, the presence of mesopores (2-50 nm) is also beneficial for CO2 capture because these pores facilitate CO2 diffusion. Thus, carbons that possess a high fraction of small micropores and suitable amount of mesopores would be ideal materials for high CO2 uptake. Phenolic resins (PRs) produced by polymerization between phenolic compounds and formaldehyde are often used carbon precursors for the synthesis of mesoporous carbons due to easy preparation. Although they are convenient precursors, PRs are highly toxic and expensive. Biomass gains a lot of attention as an alternative carbon source in economic and environmentally friendly production of carbons. However, the biomass derived carbons often have irregular porous structure and low surface area. Therefore, it is very challenging to find an effective synthesis strategy to obtain carbons with tailored porosity from diverse biomass sources. The goal of this dissertation was to develop the facile and eco-friendly synthesis routes for the preparation of micro-mesoporous carbons for superior CO2 uptake. The synthesis was designed based on green chemistry requirements, which includes the use of renewable feedstock and less toxic reagents for the carbon preparation. Porous carbons reported in this dissertation were prepared from condensed tannins, which are natural phenolic compounds, instead of synthetic phenolic compounds as carbon precu (open full item for complete abstract)

MCP, University of Cincinnati, 2020, Design, Architecture, Art and Planning: Community Planning

Access to primary health care is associated with individual and community health. However, there is often an unequal distribution of health care providers, thus leading to over and under-serviced areas. Common metrics of geographic access to primary health care tend to overestimate access as they assume an equal distribution of providers and equal access between where people live and where the health-related services are located through either private vehicles or public transit. Through land use and transport planning decisions, planners shape the built environment and therefore the distribution of different entities. In the field of transport planning, the connection between the built environment, transportation availability, and access to various destinations, such as employment, has been well established. However, coverage remains limited in terms of primary health care. The goal of this research is to provide a relatively comprehensive analysis of potential geographic access to primary health care by considering multiple factors, including modes of transport, neighborhood typologies, and individual built environment variables. Specifically, access scores for car-dependent and bus-dependent populations are separately calculated and compared across distinct neighborhood typologies to see how they change and differ between suburban and urban typologies in Hamilton County, Ohio. Then the relationship between access scores and individual built environment factors is investigated at a local scale by considering spatial heterogeneity. This study employs a multi-dimensional approach that incorporates spatial statistical modeling and geographic mapping to capture the complex relationship between the built environment and the multimodal geographic access to primary health care. The findings from this study show that commonly used metrics do overestimate access and overlook the significant differences in access experienced by car-dependent and bus-dependent populat (open full item for complete abstract)