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The KnowledgeBank at OSU (74.956 recursos)

Knowledge Bank contains collections of presentations, publications and reports related to Ohio State University.

Engineering

Mostrando recursos 1 - 20 de 602

  1. Exploring Oxygen Delivery Strategies for Oxidative Coupling of Methane

    Jindra, Michael
    A myriad of metal oxide catalysts have been explored for upgrading methane into higher hydrocarbons in a process called oxidative coupling of methane (OCM). Because of the ramifications of utilizing methane as a chemical feedstock, efforts to optimize the reactor design and catalyst for OCM process have been ongoing since 1980. Catalytic oxygen carriers (COCs) used for cycling oxygen to the reactant gas in OCM reaction processes have shown distinct advantages over cofeeding reaction schemes. Manganese based COCs have exhibited multiple oxidation states that function in the cyclic reduction oxidation reactions of OCM. This study aims to elucidate the different forms...

  2. Energy Storage Applications of Ionic Redox Transistor Membranes

    Marino, Chris
    Electric vehicles in recent years have offered a cleaner alternative to internal combustion engines (ICE’s), but the lithium-ion batteries which power them currently lack the high energy density that gasoline provides. Modern battery architectures like redox flow batteries have achieved higher energy densities than conventional Li-ion batteries, but struggle with capacity fade due to self-discharge across the microporous membranes used to separate the anodic and cathodic cells of the battery. The purpose of this research is to demonstrate the use of an ionic redox transistor membrane, which assumes the function of the standard, porous membrane, and verify its ability to...

  3. Design of an Experimentally Simulated Moving Bed Reactor for Oxidative Coupling of Methane

    Drees, William
    With the recent increase in natural gas production, methane has become an increasingly attractive compound with which to upgrade to higher value products such as ethylene. One method of great interest, the oxidative coupling of methane, has been prevented from commercialization by low yield caused mainly by reaction of intermediates and products with gas phase oxygen. This makes a chemical looping reaction scheme very attractive because in this scheme, oxygen is delivered via the lattice oxygen on a catalytic oxygen carrier (COC) eliminating gas phase oxygen contact with any hydrocarbon species. In a chemical looping scheme, a moving bed reducer...

  4. Experimental Investigations of Microchannel Cooling within a Nozzle Guide Vane Trailing Edge Configuration

    Walsh, James
    Improving component cooling to sustain higher gas turbine inlet temperatures is a widely-studied subject to improve engine efficiency. From advances in additive manufacturing technology, the use of microchannel cooling is possible within turbine components and appears advantageous due to significant heat transfer benefit within a small packaging and the ability to provide targeted cooling [1]. Although microchannel usage at relevant engine conditions has been characterized in prior research [16,18], application into a trailing edge geometry and direct comparison to current trailing edge cooling technologies has yet to be explored. The purpose of this study is to characterize the heat transfer...

  5. Selective Conversion of Glucose to Fructose with Immobilized Tertiary Amines

    Pattanaik, Lagnajit
    Increasing global energy demands necessitate research in alternative sources of energy such as biomass. Sustainable biomass conversion strategies require high yields for the isomerization reaction of glucose to fructose. The key challenge for this reaction is achieving high selectivity towards fructose using inexpensive catalytic materials. Previous studies have achieved 32% fructose yields using tin-containing catalysts (Sn-BEA zeolite) and homogeneous organic bases (triethylamine), but these catalysts are either expensive to synthesize or require energy-intensive downstream separation processes. By functionalizing a mesoporous silica material with a triethylamine analogue, we combined aspects of these studies to create an improved heterogeneous catalyst to convert...

  6. Engineering Out Systematic Oppression: Disenfranchisement, Discrimination, and Solutions for Election Systems

    Lawson, Jeremiah
    This comparative analysis reviews literature from the perspective of legal, sociological, political and engineering disciplines. The interdisciplinary approach allows for a holistic examination of what problems persist in commissioning of elections. In many cases, practical engineering considerations are forced to defer to legal precedent. I blend both historical and contemporary issues regarding elections and democracy in the United States, and I trace the failures of the election system to achieve full enfranchisement. I discuss these legal battles in the context of maintaining secure elections. I review technological aspects of elections and various election systems. A newly developed tool, the Perspective On...

  7. Intracellular Calcium Responses of Endothelial Cells Exposed to Pulsatile and Oscillatory Fluid Mechanical Shear Stresses

    Cetnar, Alexander
    Calcium (Ca2+) is a ubiquitous 2nd messenger that dictates many cellular pathways including muscle contraction, cell proliferation, and apoptosis. Disregulation of Ca2+ homeostasis is believed to contribute to vascular endothelial cell (EC) dysfunction, which transitions the endothelium to a pro-inflammatory mode, initiating atherosclerosis. Since ECs are continually exposed to fluid mechanical shear stress from blood flow, the effect that shear stress has on the intracellular Ca2+ levels ([Ca2+]i) is of major interest. Increases in fluid shear stress are known to increase cytosolic Ca2+. In ECs, the endoplasmic reticulum (ER), the mitochondria, and the extracellular media are the three main sources...

  8. An Experimental Investigation of Spin Power Losses of a Turbofan Gearbox

    McDonald, Kyler
    Planetary gear sets are commonly used in automotive, industrial and aerospace gearbox and transmission applications as they provide certain advantages over their counter-shaft alternatives. Any planetary gear set design must meet multiple requirements of size, weight, noise, load carrying capacity, fatigue life, noise, and efficiency. Planetary gear set efficiency is dictated by two classes of power losses. One class includes load dependent power losses that are induced by friction of contact interfaces and they can be predicted using physics-based models. The other class includes load independent losses that are due to interactions of the fluid with rotating gear components. These...

  9. Non-Isothermal Gas-Assisted Injection Molding at Low Capillary Numbers

    Ta, Lena
    In gas-assisted injection molding (GAIM), pressurized gas is injected into a cavity filled with molten polymer to create a mold with a hollowed core. Experimentation in non- isothermal conditions at lower capillary numbers was necessary to evaluate the accuracy of a recently developed simulation model. Fractional coverage is dependent on a multitude of parameters including the mold’s temperature gradient, delay time, and capillary number used. Capillary number is the ratio of viscous forces to interfacial tension and is a strong function of gas bubble velocity and fluid viscosity. Previous experiments have been performed at capillary numbers high enough to maintain...

  10. Computational Modeling of Cervical Remodeling During Pre-term Labor

    Stein, Cory
    Pre-term labor (PTL) is the leading cause of death for neonates and is on the rise in industrial nations. If it does not cause death, there is a greater chance that physical or intellectual abilities can occur. Normally, the cervix stays closed and firm during the gestation period to keep the baby in a controlled environment and will remodel as labor begins. The cervix goes through two phases, called cervical softening and cervical ripening, that cause the cervix to remodel. Issues in these remodeling phases can lead to PTL. PTL occurs when labor is initiated early in the gestation period,...

  11. Experimental Investigation of Nonlinear Mode Shape in Microscale Beams

    Ma, Min
    Micro-electro-mechanical-systems (MEMS) have drawn a great interest over last serval decades due to its wide applications including accelerometers and pressure sensors, micro-mirrors, radiofrequency (RF) switches, microphones, and inertia sensors. The moving mechanical element integrated in MEMS devices is typically operating in its resonant mode. Due to its small size and low damping, the micro-beams often exhibit the nonlinear resonance, which is being widely investigated to overcome the limitations of linear mode in term of its levels of sensitivity and reliability. This work covers an experimental study of the dynamic responses of micro-beams, including the nonlinear mode shape and resonances by...

  12. Induction of Hypertrophy in Human Cartilage Endplate Cells Promotes Angiogenesis and Catabolism in the Intervertebral Disc

    Yeater, Taylor
    Low back pain is second only to cancer in terms of socioeconomic burden in the U.S., but current treatments are highly invasive and fail to target the underlying cellular mechanisms of intervertebral disc (IVD) degeneration. In degeneration, the cartilaginous end plate (CEP) becomes calcified, however the mechanisms are not well understood. In diseases such as osteoarthritis, a proposed mechanism is the recapitulation of developmental processes and we suggest that in degeneration, CEP cells undergo hypertrophic differentiation similar to endochondral ossification. The aim of this study was to determine if CEP cells can undergo hypertrophic differentiation, leading to angiogenesis. Human CEP...

  13. Corrosion Behaviors of Aluminum Following a Loss of Coolant Accident

    Leong, Amanda Sue Wen
    Aluminum (Al) corrosion in the containment of nuclear reactor has detrimental effects on the performance of emergency-core–cooling system (ECCS). In a loss-of-coolant accident (LOCA), the ECCS is initiated to shut down the operation of a nuclear power plant safely. The cooling alkaline solution flowing through the ECCS has a high concentration of boric acid, which has been suggested to be corrosive to Al alloy. Precipitations caused by Al corrosion potentially obstructs the sump screens while the solution is re-circulated in the nuclear core through ECCS. This study aims to understand the release and corrosion behaviors of Al alloy exposed to...

  14. Study of Co-Injection Processes using Viscous Newtonian Fluids in a Hele-Shaw Cell

    Ellison, Matthew
    Co-injection molding incorporates the use of two or more immiscible polymers to make a singular part. Industrially, this process is accomplished by injecting one material within another to create a skin and core combination. This allows for the creation of parts that combine desirable characteristics such as rigidity and flexibility seen in products ranging from toothbrushes to phone cases. In addition, this process is used to create plastics that combine virgin and recycled material without sacrificing durability through degradation. To better understand the influence of viscosity and surface tension in the co-injection process, a Hele-Shaw cell, consisting of two long...

  15. Optical Detection of Acoustically Driven Ferromagnetic Resonance

    Guo, Qiaochu
    The nitrogen-vacancy (NV) center is a diamond defect that has been considered a potential material to develop nanoscale magnetometers. In this study, we use NV-centers in diamond to optically detect ferromagnetic resonance (FMR) driven by surface acoustic waves. An experimental setup was designed to simultaneously measure the fluorescence of NV-diamonds and electrical transmission signal when the ferromagnetic sample reaches FMR. We investigated the correlation between NV-center fluorescence and input microwave frequency, external magnetic field, and position relative to the ferromagnetic material. Moreover, we developed a scanning magnetometer by attaching NV-diamonds to the tip of an AFM probe. An optically detected...

  16. Particulate Adhesion and Removal From Substrates

    Beal, Patrick
    One of the major issues plaguing the semiconductor industry is the adhesion of submicron-sized particles (called particulates) to silicon wafers (substrates) during wafer manufacturing. Such substrate contamination results in unreliable performance of the wafers when used as the foundation for integrated circuits, causing electronic device failure. Currently, brush cleaning, Atomic Force Microscope (AFM) manipulation, and laser induced shock waves are utilized to cleanse contaminated substrates. While these are genuine contributions to particulate removal efforts, the prohibitive cost and lack of efficiency in mass-scaling these techniques pose major issues. This project aims to develop an efficient technique to remove particulates from...

  17. Investigation of Light-off Temperature and Conversion Efficiency of Electrically-Heated Catalyst

    Yang, Shuhan
    As concern for the environmental issues become more severe, emission regulations are becoming more stringent. To meet increasing demands of emissions regulations, industrial leading auto maker try to replace the conventional gasoline vehicles by renewable vehicles such as EVs (electrical vehicles) and PHEVs (Plug-In Hybrid Electrical Vehicles). Although these renewable vehicles decrease the annual emission greatly, the manufacturing cost and operational range are primary constrains to prevent the mass production in large scale. On top of this, TWC (Three-Way Catalyst) is the current solution to reduce the emission on the conventional vehicles. But it is limited during the cold start...

  18. Quantification and Analysis of Carbon Deposition on Catalytic Oxygen Carriers for the Oxidative Coupling of Methane

    Ikeda, Kevin
    The current commercial method of obtaining ethylene, a highly valuable product, through steam cracking is highly process and energy intensive. An alternative way to obtain ethylene is through the direct conversion of natural gas to ethylene in a one step process through oxidative coupling of methane (OCM). A chemical looping scheme is an attractive mode of operation for OCM because of the enhanced selectivity towards ethylene made possible by a catalytic oxygen carrier (COC). However, a major concern for this process is carbon deposition, or “coking”, which deactivates the COC by blocking active sites. Coking may be prominent in a...

  19. Improvement of Reliability Indices in a Micro-grid System involving Renewable Generation and Energy Storage

    Reed, Emily
    Integrating renewable energy sources is important to policy-makers worldwide, especially as the depletion of traditional energy sources and the declining health of the environment continue to be of critical concern. As the installation costs of renewable generation decrease, the incorporation of these sources into the grid is becoming more attractive and feasible. However, in order for renewable generation to be incorporated on a large scale, utilities must be able to guarantee that customers receive adequate and quality power, constituting a reliable system. Thus, ensuring the reliability of a grid system that includes sources of generation with low predictability and high...

  20. Retrofit of Reinforced Concrete Columns

    Gaitan, James
    Many reinforced concrete structures are deficient in stiffness, ductility, and strength capacity compared to current standards. When a powerful event, such as an earthquake, occurs, un-strengthened and inadequate concrete members may fail and produce catastrophic results. In order to counteract this problem, many different retrofit and repair methods have been studied, implemented and have produced a variety of results. This research is focused on comparing dozens of retrofit and repair methods for reinforced concrete columns in order to analyze the efficacy of these methods. The primary methods compared are reinforced concrete jacketing and a variety of steel confinement methods. The...

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