Doctor of Philosophy, The Ohio State University, 2017, Environmental Science

Carbon dioxide concentration is increasing in the atmosphere. This has encouraged the world community to change its energy usages from a fossil resource-based that currently dominates to a renewable bio-based in the future. This opened the door for “solutions from the land” which has led to exploration of land used in the Conservation Reserve Program (CRP) with mixed prairie plant genomes. CRP, a massive public-private partnership program was instituted in 1985 and has reached a total enrolment of about ~10 million hectares that has not been harvested during the past 30 years. Much of the CRP land has degraded, resulting in reduced land cover and a net loss of primary productivity. This research is based on the premise that CRP lands can be harvested for to supply biofuel feedstocks or forage for livestock without long term harmful effects on the plant community and soil environment and without compromising wildlife habitats. This may lead to a Win-Win situation where lignocellulosic materials can be harvested from the CRP lands while at the same time protecting wildlife habitat. In 2009, CRP land located near Piketon, OH was selected for this study. The site was planted in 1999 with nine different warm-season perennials in a prairie mix that had not been harvested for ten years. The site was burned once in 2009 to get rid of weeds and brambles. Treatments imposed on this land in 2009 were designed to test the effect of N fertilization and harvest timing and frequency on the response of CRP land. Five levels of N (0, 10, 20, 40 and 80 kg N ha-1) and three management strategies (A: Harvest in March or April; B: 1st harvest in May, and 2nd harvest in March or April; and C: Multiple harvests during May through October) with four replications in a factorial randomized complete block design with a strip-block restriction on treatment randomization. Energy yields (GJ ha-1 yr-1) increased from 96.0 in 2009 to 287.0 in 2014 with Management-A, 83.0 in 2009 to 202 in 2014 (open full item for complete abstract)

Committee: R. Mark Sulc Ph.D. (Advisor); Warren Dick Ph.D. (Committee Co-Chair); Richard Moore Ph.D. (Committee Member); Norman Fausey Ph.D. (Committee Member) Subjects: Environmental Science; Natural Resource Management; Soil Sciences

Doctor of Philosophy, The Ohio State University, 2023, Food Science and Technology

Underutilized biomasses hold promise as sustainable food, feed, and fuel. As food, novel materials must be nutritious, safe, and desirable to consumers while causing minimal environmental damage. This dissertation hopes to encourage future cultivations of macroalgae and an insect, Hermetia illuscens (the Black Soldier Fly larvae, BSFL). Macroalgae and BSFL are associated with environmental benefits including low land, water, and energy demands. They are both nutritious but are not readily accepted by modern consumers as food. To facilitate their adoption, novel materials must take the shape of familiar foods. This requires processing into novel food ingredients. Environmental impacts increase as processing and materials are employed during the creation of novel ingredients. While the desirability of the final product may benefit, the process must be scrutinized to reduce resource use and ensure sustainability. Extraction and separation operations aim to concentrate a specific component, such as protein, in a single fraction. Depending on the composition, the remaining materials will also have value. Optimal co-product development requires that the influence of each process parameter be well understood. This is advantageous to processors since each additional product shares the costs and environmental impacts associated with production. The research aimed to evaluate hypotheses concerning the influence of processing parameters on material separation and physicochemical properties after biomass fractionation. The following specific objectives were addressed during this research 1) understand the nutritional quality of macroalgae and BSFL, 2) evaluate aqueous extracts from BSFL and macroalgae, 3) develop an experimental fractionation system to monitor component separation using experimental data and mass balance relationships, and 4) evaluate the effects of process parameters on the outputs of the fractionation. Macroalgae and insects were found to be promising fut (open full item for complete abstract)

Committee: Dennis Heldman (Committee Chair) Subjects: Agricultural Engineering; Food Science

Doctor of Philosophy, The Ohio State University, 2022, Economics

This dissertation contains three chapters bringing together my work in investment, maintenance, and repair. In the three chapters, I construct a market-oriented M&R model to match the stylized facts of the M&R markets in the real world and use it to explore the significance of M&R in the aggregate economy. I present the techniques and difficulties in incorporating the M&R model into a macro-finance framework with endogenous debt default and develop a feasible algorithm to solve the macro-M&R model with non-convexity and multiple equilibria. In the first chapter, titled "Maintenance and Repair: A Parsimonious Model," I modeled the production and trading of maintenance and repair (M&R) in the after-market of capital and developed a generalized model to match the stylized facts documented in the micro studies and survey. In almost all previous studies, the M&R produced by the third parties M&R companies and the capital producers are assumed to be homogeneous. However, I revise this assumption and utilize a CES function to describe the complementarity among the M&R goods made by different producers. Such settings allow me to model the locked-in effect in the M&R market and keep the structure of the M&R market more consistent with the real world. Given the M&R model, I then propose a novel calibration strategy so that the cyclicality and the volatility of the aggregate M&R expenditures sequence generated by the model match the correspondent statistics in the data. In the second chapter, titled "Quantifying the Indirect Cost of Financial Distress," I study the interactions between the firm's financial condition and the demand for the goods it produces, focusing on the physical capital manufacturers in Canada. The interactions are constructed through the capital's maintenance and repair (M&R), which is also supplied by capital manufacturers and is necessary to keep the used capital operative. When the possible bankruptcy of a financially distressed manufacturer makes (open full item for complete abstract)

Committee: Sanjay Chugh (Committee Chair); Pok-sang Lam (Committee Member); Mario Miranda (Committee Member) Subjects: Economics

Doctor of Philosophy (PhD), Wright State University, 2020, Engineering PhD

This research focuses on the hierarchical structure of bone and associated mechanical properties at different scales to assess damage accumulation leading to premature failure, with or without instrumentation. In this work, an attempt was made to develop a framework of macro, micro, and nano damage accumulation models and implementing them to derive mechanical behavior of the bone. At macrolevel, retrospective evaluation of 313 subjects was conducted, and the damage of bone tissue was investigated with respect to subject demography including age, gender, race, body mass index (BMI), height and weight, and their role in initiating fracture. Experimental data utilized 28 human femoral bones implanted with cephalomedullary nails were used to develop damage prediction models. Investigation of three real life medical device failures identified the mechanical and clinical bases of bone failure. At the micro level, microdamage accumulation of the bone was investigated in 307 subjects and new effective morphological parameters at microscale were proposed. At the nano level, molecular dynamics simulation was performed to investigate the effect of interaction, orientation, and hydration on the atomic models of the bone composed of collagen helix and hydroxyapatite crystal. The results showed that bone density and maximum von Mises stress decreased drastically in elderly patients, implying fixation devices and implants used by the young cannot be used. The results also showed that the two-dimensional representation of the morphological parameters of the bone at microscale does not provide a realistic description of bone structure. Therefore, in this work, three-dimensional representations at microscale indicated that bone interconnectivity is higher in female patients than in male patients. Gender has a significant effect on microdamage distribution in the bone. More precautions should be taken into consideration for older female patients. Race should also be considered during (open full item for complete abstract)

Committee: Tarun Goswami D.Sc. (Advisor); Caroline GL Cao Ph.D. (Committee Member); Arnab K. Shaw Ph.D. (Committee Member); Partha P. Banerjee Ph.D. (Committee Member); Richard T. Laughlin M.D. (Committee Member); Jennie J. Gallimore Ph.D. (Committee Member) Subjects: Biomechanics; Biomedical Engineering; Biomedical Research; Engineering; Industrial Engineering; Molecular Biology; Nanoscience; Nanotechnology

Master of Science (MS), Wright State University, 2020, Computer Science

In the last decade, the advent of social media and microblogging services have inevitably changed our world. These services produce vast amounts of streaming data, and one of the most important ways of analyzing and discovering interesting trends in the streaming data is through clustering. In clustering streaming data, it is desirable to perform a single pass over incoming data, such that we do not need to process old data again, and the clustering model should evolve over time not to lose any important feature statistics of the data. In this research, we have developed a new clustering system that clusters social media data based on their textual content and displays the clusters and their locations on the map. Our system takes advantage of a text stream clustering algorithm, which uses the two-phase clustering process. The online micro-clustering phase incrementally creates micro-clusters, called text droplets, that represent enough information about topics occurring in the text stream. The off-line macro-clustering phase clusters micro-clusters for a user-specified time interval and can change macro-clustering algorithms dynamically. Our experiments demonstrated that the performance of our system is scalable; and it can be easily used by first responders and crisis management personnel to quickly determine if a crisis is happening, where it is concentrated, and what resources are best to deploy to the situation.

Committee: Soon M. Chung Ph.D. (Advisor); Nikolaos Bourbakis Ph.D. (Committee Member); Vincent A. Schmidt Ph.D. (Committee Member) Subjects: Computer Science

MS, Kent State University, 0, College of Education, Health and Human Services / School of Health Sciences

The purpose of this study was to determine the differences between nutritional knowledge of mothers of preschoolers and the growth status and dietary intake of preschoolers who attend the Child Development Center at Kent State University for which two hypotheses were stated. The independent variable of this study was knowledge of the mother and the dependent variables was the growth status of the child measured by plotting the child's BMI-for-age and the dietary intake of the child which was assessed by taking a 24-hour food log and by evaluating macronutrient (energy, carbohydrate, protein, total fat, saturated fat) intake of the child. The data was collected by a paper-pen survey. Mothers were asked to fill the first four sections of the survey at the CDC and were given the 24-hour-food log to be filled in at home. Total 29 mothers participated in the survey from which 13 mothers turned in the food log of the child. One-way analysis of variance was used in SPSS version 24.0 to analyze the quantitative data and themes and patterns were formed to analyze the qualitative data. The results indicated that there was no significance found (p>0.05). The overall education level of the mothers was observed to be high with the majority of them having a Masters or a Ph.D. degree, but their nutrition knowledge in general was found to be extremely low. While the current study provided beneficial insights into mother's nutrition knowledge, the results indicated an overall lack of impact of mother's nutrition knowledge on the growth status and dietary intake of the child (p>0.05). Despite previous research supporting the influence of mother's nutrition knowledge on a child's development and dietary intake, this study lacked many positive outcomes previously obtained, indicating that additional research is necessary to assess the impact of mother's nutrition knowledge on growth status and dietary intake of the child.

Committee: Natalie Caine-Bish (Advisor); Karen Lowry Gordon (Committee Member); Emily Baker (Committee Member) Subjects: Nutrition

Master of Science (MS), Ohio University, 2019, Geological Sciences (Arts and Sciences)

Geochemical analysis was carried out on samples of environmental phases (water, sediments, and soils) from La Barra de Santiago estuary (El Salvador, Central America) and adjacent streams to understand the dynamics and possible environmental and health effects of heavy metals, nutrient and sulfate concentrations in the ecosystem. Physiochemical parameters such as nutrient concentration (Nitrate and Phosphate), oxidation reduction potential (ORP), dissolved oxygen (DO), conductivity, total dissolved solids (TDS), pH, temperature, Chloride, Iodide and sulfate concentrations were determined using spectrophotometric methods, while heavy metal analysis was carried out using ICP-MS. Multivariate statistical methods, including correlation analysis (CA) and principal component analysis (PCA) were applied to define the mutual relationships between these parameters. Low concentration of sulfate in the water and sediments suggest it is unlikely that sulfur contamination due to the eruption of Santa Ana volcano in 2005 could be causing the lack of macroinvertebrates in the region. Phosphate in sediments and soil samples has low variability in concentration probably due to buffering by the solubility of phosphate minerals, whereas Nitrate concentration in the sediment is higher than in soil samples. High nutrient concentration and chloride in the region with low DO (symptoms of eutrophication) suggest hypernutrification could be the driver for the lack of macroinvertebrates in the estuary. The statistically significant relationships between Sr, Rb and Cl, and between Sr, Rb and SO4, suggest a chemical contribution from marine sources for these elements, while correlation between Fe, Cu, Cd, Zn, Cr, Ce, Co and Al indicates inland input into the ecosystem for these metals. Lastly, results from sediment quality assessments using several pollution indices such as geoaccumulation index (Igeo), mean-ERM quotient, concentration factor (CF), pollution load index (PLI), and contaminatio (open full item for complete abstract)

Committee: Dina Lopez (Advisor); Gregory Nadon (Committee Member); Keith Milam (Committee Member) Subjects: Agricultural Chemicals; Aquatic Sciences; Biogeochemistry; Biological Oceanography; Chemical Oceanography; Earth; Ecology; Environmental Geology; Environmental Health; Environmental Science; Environmental Studies; Geochemistry; Geological; Geology; Marine Geology; Natural Resource Management

Master of Sciences (Engineering), Case Western Reserve University, 2018, Chemical Engineering

Inexpensive and scalable energy storage is necessary for the transition to a cleaner, more sustainable, electricity grid. The Acid-Base Energy Storage System (ABESS) utilizes an extremely inexpensive, safe, and abundant electrolyte, can be deployed anywhere without geographical constraints, and is predicted to be economical at very large energy storage capacities and long discharge times. The ABESS stores energy by utilizing the potential difference created by a proton (H+) concentration gradient in a saltwater electrolyte. The coulombic efficiency (ηC ) of an ABESS is unknown and it is crucial to understand for further development. In this thesis, the mass transport of the active species through Nafion® was measured and modeled in the charging of an ABESS under a high salt environment to determine ηC limitations. A macro-homogeneous model based on dilute solution theory utilizing Nernst-Planck equations was developed to relate ηC to the current density of an ABESS during charging. Effective diffusivities and transference numbers of sodium and active species under various electrolyte conditions were experimentally determined and reported for an ABESS operating with a concentrated saltwater electrolyte and a Nafion® separator. Using a Nafion®-212 membrane and a saturated sodium sulfate electrolyte at room temperature (∼1.5M Na2SO4 at 22°C ± 1.0°C), a maximum ηC of 86.7% ± 2.5% was measured during charging at 100 mA/cm2 up to a concentration of 0.5N Acid/Base in the respective reservoirs. These are promising results and show that a full battery will be able to achieve a 70% - 75% overall energy efficiency, comparable to other flow battery technologies.

Committee: Jesse Wainright Dr. (Advisor); Robert Savinell Dr. (Committee Member); Christine Duval Dr. (Committee Member) Subjects: Alternative Energy; Chemical Engineering; Energy; Engineering

MS, Kent State University, 2017, College of Arts and Sciences / Department of Computer Science

ImageJ is a java based open source desktop application which is widely used in the image processing community. It is a combination of various user authored plugins. The developer API can be used to implement new plugins for specific image processing tasks or analysis. However, ImageJ wasn't designed to work on a distributed system. Currently, it is still being used on single machines to process large medical images which takes several hours to complete. In this thesis, we make a number of important and widely used ImageJ plugins to work within a clustered architecture. For easy communication among distributed nodes of the cluster we used a shared drive cluster architecture. One of the main challenges of running these plugins on a cluster is to generate combined final results with high accuracy from outputs generated by the original existing processing plugin running on different nodes. We implement several ImageJ plugins to distribute tasks and generate combined results. In particular, we consider the 3D object counter plugin for testing the developed cluster based system. Experimental results on test images shows high accuracy and similarity with single machine based results. However, for extra overhead for task distribution and gathering results we obtain improved performance of our system only for large size images in terms of execution time.

Committee: Cheng Chang Lu (Advisor); Robert J. Clements (Advisor); Arvind K. Bansal (Committee Member); Kambiz Ghazinour (Committee Member) Subjects: Computer Science

Master of Science (MS), Ohio University, 2017, Mechanical Engineering (Engineering and Technology)

Inaccuracy in cable suspended robots has led to research in the addition of a micro system to correct for the inaccuracies of the macro system (cable suspended robot). With the addition of this micro system, the total system inherently becomes kinematically redundant. Due to this, the two systems can be configured in such as to have minimal uncertainty with respect to an end effector pose. For the selection of the minimal uncertainty configuration, a genetic algorithm was used. The genetic algorithm assessed the robotic system with respect to compensability (tracking performance) and minimal configuration change. The reason for these two parameters is to provide an optimal trajectory generation for the control of the macro/micro system to minimize inaccuracy. This controller design dependent on the optimal trajectory generation was compared to the macro/micro system without control to show the improved effect. Finally dependent on these results, recommendations were made with respect to how to improve the genetic algorithm as well as a different trajectory generation method for a macro/micro cable suspended robot.

Committee: Robert Williams II/Ph.D. (Advisor); Timothy Cyders Ph.D. (Committee Member); David Burnette Ph.D. (Committee Member); Todd Young Ph.D. (Committee Member) Subjects: Robotics

Master of Science, The Ohio State University, 2016, Allied Medicine

One population of healthcare workers for which the link between job specific activities and work-related musculoskeletal disorders (WRMSD) has been reported are sonographers. Existing literature on the topic has focused on self-reported survey data which has demonstrated that upwards of 80% of sonographers perform their jobs in pain. Many studies have identified risk factors for WRMSD relating to the micro-ergonomic interface between sonographer and equipment and the macro-ergonomic interface between sonographer and hospital organization. However, very few prospective or intervention studies which address these risks have been executed. Recent research has demonstrated the feasibility of mind-body techniques in the improvement of micro- as well as macro-level ergonomic concerns for populations of professionals at-risk for developing WRMSD. The current study was designed as a prospective teaching pilot of a series of mind-body techniques for a group of student sonographers. The proposed research question is: What combination of mind-body techniques, taught to a cohort of novice sonography students, would provide exploratory reduction of the risk of WRMSD? A pre-post experimental design was employed and longitudinal data were collected from a cohort of first year sonography students at The Ohio State University (n=12). In order to measure variables of self-reported health influenced by micro-and macro-ergonomic factors, a set of surveys was administered to participants at study baseline and upon completion of the interventions: the Short-Form Health survey, the Perceived Stress Scale, and the Visual Analog Scale for upper extremity pain. Students who participated in the study were exposed to two types of interventions: ergonomics education and mind-body techniques. As ergonomics education is a curricular requirement of accredited sonography programs, this intervention was delivered to all participants. The two mind-body techniques employed were biofeedback an (open full item for complete abstract)

Committee: Kevin Evans PhD (Advisor); Maryanna Klatt PhD (Committee Member); Carolyn Sommerich PhD (Committee Member) Subjects: Health Care; Health Sciences; Occupational Health; Occupational Safety

Doctor of Philosophy, The Ohio State University, 2015, Industrial and Systems Engineering

The long term goal of this study is to prevent work-related musculoskeletal disorders associated with physically demanding activities through the adoption of an ergonomics intervention. The adoption was considered a process that involves multiple stages of behavioral change towards intervention use based on the Stages of Change Model. Factors believed to affect an individual's adoption stage were examined for their positive impact as a facilitator or negative impact as a barrier. The current study was conducted in the context of health care workers' adoption of a lifting device. The aims of this study were to (1) develop a survey instrument that could be used to assess adoption stages of a lifting device and categorize the barriers and facilitators, (2) identify key factors that differentiate between stages and (3) develop adoption models that classify an individual's adoption stage based upon that individual's response to selected factors. This study used a survey instrument to assess individuals' adoption stages and to assess factors that potentially affect individuals at each adoption stage in specific resident-handling situations where a lifting device with a full-body sling is recommended to use by The National Institute for Occupational Safety and Health. These situations include the following: Situation 1 represented the transfer of a non-cooperative resident that was able to partially bear weight, Situation 2 represented the transfer of a cooperative resident unable to bear weight, and Situation 3 focused on repositioning a patient. Survey data were collected from 297 healthcare professionals in 12 skilled nursing facilities. Based on reported frequency of use and intention to use a lift device, an individual was classified as a full adopter, partial adopter, trial user, contemplator, pre-contemplator, or non-adopter. The results indicate that the distribution of adoption stages varies by resident-handling situation. In Situation 1, participants were evenl (open full item for complete abstract)

Committee: Steven A. Lavender (Advisor); Carolyn M. Sommerich (Committee Member); Emily S. Patterson (Committee Member) Subjects: Industrial Engineering

MS, University of Cincinnati, 2011, Engineering and Applied Science: Computer Science

Development of femtocells is the most recent step towards increasing the network capacity of a wireless network and improving the quality of service for cellular users. However, large scale femtocell deployment can significantly affect existing wireless network. We examine the effect of interference due to closed-access femtocell deployment in a wireless network on macro users. Numerical analysis and simulation are performed in order to understand the impact of femtocells in an existing wireless network. Another interference scenario arising in such networks is the interference amongst neighboring femtocells. This is due to the fact that all the femtocells use the same radio band, and thus it poses a serious interference issue amongst neighboring femtocells, especially when femtocells are densely deployed. We study the problem of downlink and uplink interference used in conjunction with the LTE technology and propose a solution to mitigate this interference using Fractional Frequency Reuse (FFR) technique. User equipments (UEs) report to their serving femto base stations (F-BS) periodically. If the report reveals high interference level, neighboring F-BSs locally adopt FFR in a coordinated but decentralized way. FFR divides the femtocell in cell-center and cell-edge areas where the cell-edge of interfering F-BSs use distinct set of sub carriers. The division takes place in a way such that the affected UE falls in the cell-edge area. The simulation results indicate that the proposed scheme decreases interference in the neighboring F-BSs, femto UEs (F-UEs) and macro UEs (M-UEs) and improves the overall throughput.

Committee: Dharma Agrawal DSc (Committee Chair); Chia Han PhD (Committee Member); Carla Purdy PhD (Committee Member) Subjects: Computer Science

PhD, University of Cincinnati, 2004, Engineering : Computer Engineering

This work focuses on the development of accurate and efficient performance parameter macro-models for use in the synthesis of analog circuits. Once constructed the mathematical models may be used as substitutes for full SPICE simulation, providing efficient computation of performance parameter estimates. In this thesis, we explore various modeling architectures, develop and apply two unique sampling methodologies for adaptively improving model quality, and attempt to apply the sizing rules methodology in order to perform dimensional reduction and ensure proper operation of analog circuits. In order to properly create an analog performance model, a training data set is needed to create the model, and an independent validation data set is needed to verify the accuracy of the model. The training and validation data sets are comprised of discretely sampled points in the design space. Various methods exist for generating these sample points. A static sampler does not take into account the shape of the function under scrutiny, whereas an adaptive sampler strives to reduce modeling error through strategic placement of costly sample points. Two unique adaptive sampling methodologies are developed and are applied to various analog circuit performance metrics. It is shown experimentally that both adaptive samplers are capable of improving maximum modeling errors for various performance metrics and analog topologies. Strategic placement of costly sample points improves model quality while reducing the time needed to create the performance models. Adaptive sampling also alleviates human intervention during model construction, realizing an automatic framework for sampling and modeling performance parameters. The sizing rules method and feasibility region modeling are analyzed and applied to analog performance macro-modeling in an attempt to automatically reduce the dimensionality of the design space, simplify performance parameter behavior, and ensure proper DC biasing. A feasib (open full item for complete abstract)

Committee: Dr. Ranga Vemuri (Advisor) Subjects:

MS, University of Cincinnati, 2003, Engineering : Electrical Engineering

Work has been carried out to help develop a potentially revolutionary planar microLHP (Micro Loop Heat Pipe) in a collaborative team effort. The author has made several contributions including considerable improvements in the area of CPS (Coherent Porous Silicon) etching in which the etch rate was increased by an order of magnitude from 0.08 mm/min to 1mm/min. The reliability of the CPS etching process was increased from 10% to over 90%. Different modes of CPS etching were explored that include potentiostatic and galvanostatic. The importance of a Si3N4 passivation layer during CPS etching is discussed. The porosity of wicks used in the LHP test was increased from 6% to 25-40%. A characterization technique was introduced to cut down time between CPS etch runs. Multiple packaging issues were addressed such as the idea of using a secondary wick in the CPS based LHP and the intricate issue of evacuating and backfilling this microfludic MEMS device. The first ever closed loop test results gathered by the author are presented and discussed. A introduction into the thermal modeling of the LHP and evaporator package is discussed. A full model of the CPS based LHP is under development by colleagues in the mechanical engineering department. Finally, known areas of improvement in the CPS based LHP are discussed.

Committee: Dr. H.T. Henderson (Advisor) Subjects:

MS, University of Cincinnati, 2003, Engineering : Electrical Engineering

The present work deals with the development of a very novel and prototypical Micro Loop Heat Pipe (LHP) using the Coherent Porous Silicon (CPS) technology developed at the University of Cincinnati for different thermal and space applications. The main emphasis of this thesis is the development of an automated process for batch fabrication of Coherent Porous Silicon (CPS) wicks and development/characterization of novel anodic bonding techniques. The micro cooling of Integrated Circuits (IC), solar cells are some of the applications of LHP. In this work, it was determined that individual wafers should be given individual attention in determining the critical parameters for etching. A generalized approach, while ignoring the wafer level details has many limitations. A method to determine critical current density was established by introducing a current-voltage sweeps, before etching. Different types of etching methods are studied viz., potentiostat etching mode, galvanostat etching mode, current compensation mode and light compensation mode. In this present study, it was also determined to have a higher etch rate and uniform concentration of the etchant in the etch rig. A new flow system was developed, which would increase the temperature of the etchant, for faster etch rates. This new system would supply fresh etchant to the etching rig. Etchant level controlling logic was also implemented. One of the challenging micro processing technique needed to make a LHP package is bonding wafers producing hermetic seals. The mechanisms of formation of anodic bonds between glasses and metals are examined. Prior research works suggests electrochemical, electrostatic and thermal mechanisms for bond formation, but the dominant mechanism has not been clearly defined. The process is found to be an electrochemical analog to thermal glass-to-metal seals, where the metal surface is oxidized into the glass due to the development of large electric fields across the anodic depletion layer. (open full item for complete abstract)

Committee: DR. H. HENDERSON (Advisor) Subjects:

Doctor of Philosophy, The Ohio State University, 2012, Environmental Science

Widespread automobile use has left a distinctive mark on urban transportation in the United States, where growth has been tailored to automobiles. Although cars enable people to travel farther than at any point in human history, evidence of their costs has grown. In particular, the environmental impacts of automobiles are extensive, including air and water pollution, greenhouse gas emissions, and reductions in urban transportation ecoefficiency (TE). Overall, TE is the environmental impact per unit of travel; as a concept it can capture differential impacts of different transportation modes and travel distances. There are large variations in TE between metropolitan areas, and it is important to investigate factors that influence it to determine what measures can reduce the environmental impact of transportation. This dissertation describes the concept of TE in depth, arguing that it captures the systemic environmental impacts of transportation and is ideal for macro-level transportation studies. A TE measure using readily available data is then proposed, with four components: 1) percent of commuters driving to work; 2) percent of commuters taking public transit; 3) percent of commuters walking or riding a bicycle; and 4) population density. A confirmatory factor analysis and discussion of TE trends demonstrate that these components are useful for measuring TE and consistent in their relationships over time. Using this measure the trend for TE is downward – most U.S. metropolitan areas have seen TE decline over the last 30 years. Next, a macro-level analysis of institutional and structural predictors of TE is presented. Specifically, a general linear regression is used to predict TE change from 1980 to 2008, for a sample of 225 Metropolitan Statistical Areas (MSAs). Since the trend in TE is downward, a positive relationship indicates a slower decline in most cases. Results point to the following conclusions: * A New Political Culture (NPC), measured by professiona (open full item for complete abstract)

Committee: J. Craig Jenkins PhD (Advisor); Ed Malecki PhD (Committee Member); Maria Conroy PhD (Committee Member); Richard Yerkes PhD (Committee Member) Subjects: Area Planning and Development; Environmental Science; Environmental Studies; Geographic Information Science; Geography; Land Use Planning; Political Science; Sociology; Sustainability; Transportation; Transportation Planning; Urban Planning

Doctor of Philosophy, University of Akron, 2012, Polymer Engineering

Biocompatible and biodegradable polymeric systems benefit the biomedical field in applications such as tissue engineering, drug delivery, and implantable devises. In order for these applications to experience wide spread use, rapid and efficient production of these materials with controllable mechanical and degradative properties needs to be possible. Furthermore, the biomaterials should be easily incorporated into the body with minimal damage. In the first part of this study, telechelic acrylic poly(lactic acid) (PLA) oligomers were prepared through transesterification of PLA with ethylene glycol diacrylate. The oligomers were then incorporated into a series of photopolymerizable, biodegradable, and biocompatible films. The second part of this study introduces a new initiation method, magnetic initiation, which will allow polymeric systems to be polymerized without the use of heat or application or radiation. In magnetic initiation, free radicals will be produced by means of a magnetic macro-initiator (MI) and an alternating current magnetic field (AC MF). PLA films were formulated to contain either 1,4-Butanediol dimethacrylate (BDDM) or triethylene glycol dimethacrylate (TEGDMA). The kinetics of the photopolymerizable material was studied by photo-differential scanning calorimeter (DSC). Additionally, the tensile properties, pencil hardness, reverse impact resistance, pull of adhesion, and solvent resistance of the coatings were evaluated. Degradation was monitored by direct measurement of the carboxylic acid groups formed upon ester hydrolysis of the films in an enzyme solution by means of titration. Photo-DSC results showed that the photo-curing speed of the samples decreased as the concentration of PLA increased. Both water uptake and degradation rate increased as the concentration of PLA increased and were higher for films formulated with TEGDMA, for a given PLA concentration. The degradation rate of the films was proportional to the water uptake of the film (open full item for complete abstract)

Committee: Mark Soucek Dr. (Advisor); Thein Kyu Dr. (Committee Member); Gustavo Carri Dr. (Committee Member); David Modarelli Dr. (Committee Member); Kevin Cavicchi Dr. (Committee Chair) Subjects: Engineering; Polymers

Doctor of Philosophy, University of Akron, 2012, Civil Engineering

An analytical method has been developed to simulate the impact response of triaxially braided carbon fiber - epoxy composites, including the penetration velocity and impact damage patterns. Textile composites are being analyzed for their use in a variety of impact and containment situations. In particular, analysis methods that capture the architecturally dependent damage observed in impact tests in a computationally efficient manner are required. Before an impact simulation can be generated, all material input parameters must be found. The objective of this study is to develop an overall analysis method; creating a systematic method to determine the required input properties is just a portion of the work. In order to determine the input parameters, both the fiber and matrix properties and static tests conducted on standard coupon samples are used. In the analytical model, the triaxial braid architecture is simulated by using four parallel shell elements, each of which is analyzed as a laminated composite. Specifically, non-shifted homogeneous subcells, and a new, more systematic method for impact property determination was developed. In order to determine the stiffness and strength properties required for the constitutive model used, a top-down approach for determining the strength properties is merged with a bottom-up approach for determining the stiffness properties. Combining these two types of calculations allows the material parameters to be established using a systematic approach. The model is correlated with the actual material properties using quasi-static coupon level tests for a number of representative triaxially braided composite materials. The resulting model is then used to conduct a number of simulations. Specifically, the impact of a flat plate with a gelatin projectile, a flat plate with an aluminum projectile, and a composite tube pressurized with an elastomer are simulated and compared with experimental impact tests for a range of triaxially b (open full item for complete abstract)

Committee: Wieslaw K. Binienda Dr. (Advisor); Robert Goldberg Dr. (Committee Member); Ernian Pan Dr. (Committee Member); Anil Patnaik Dr. (Committee Member); Xiaosheng Gao Dr. (Committee Member); Kevin Kreider Dr. (Committee Member) Subjects: Aerospace Materials; Civil Engineering; Engineering; Materials Science; Mechanical Engineering