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The KnowledgeBank at OSU (80.208 recursos)

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

Engineering

Mostrando recursos 1 - 20 de 681

  1. The Role of Passengers' Satisfaction with Transit Service Quality - Dissecting Customer Satisfaction

    Li, Mingfeng
    Many large US transit agencies see high levels of ridership turnover, but currently, little is known about how turnover can be predicted. In an effort to better understand customers, many transit agencies conduct surveys at regular intervals, and a key element of those surveys are questions regarding satisfaction. This thesis dissects the relationship between satisfaction with public transportation services and passengers future travel behavior. The goal of this thesis is to show how satisfaction with transit services influences transit customer loyalty. Speci cally, it is composed of three parts: First, it assesses the potential association between transit user behavior and...

  2. Investigating Effects of Spray Characteristics on Fuel-Air Mixture Formation

    Yu, Mingzhe
    Fuel-air mixture formation is an important research topic in the internal combustion (IC) engine field with respect to fuel consumption and emissions of a vehicle. Spray characteristics have significant effects on fuel-air mixture formation. In this research, spray and fuel-air mixture formation processes in the gasoline direction injection (GDI) engine are simulated in the pre-built models in the commercial software Converge CFD with emphasis on the effects of spry characteristics on such processes. The focus is placed on the effects of the injector configuration and operating conditions. A pre-built model is modified by adding spray modeling including injector and nozzles....

  3. Inductively Coupled Plasma Reactor for High-Yield Carbon Vaporization and Generation of Vibrationally Excited CO in Reaction with Molecular Oxygen

    Gulko, Ilya
    Recent work in the Nonequilibrium Thermodynamics Laboratories demonstrated that a chemical reaction between carbon atoms, generated in a high-temperature arc discharge with graphite electrodes, and molecular oxygen produces highly vibrationally excited CO. In these experiments, absolute population inversion among CO vibrational levels has been detected in a collision-dominated environment, suggesting feasibility of development of a novel CO chemical laser. This laser would be able to operate in a high-speed airflow over a hypersonic vehicle, with carbon vapor generated by surface ablation or by evaporation of amorphous carbon powder injected into the flow. Carbon atoms would then react with molecular oxygen...

  4. Design and Prototyping of a Transformable Quadruped Robot

    Cheng, Yupeng
    Quadruped robotic mechanism is a legged robotic structure using four legs to move. In many legged robotic structures, quadruped is the ideal one for mobility performance and efficiency. Quadruped robots features more stable and more smooth movement than wheeled robots on rough and complex terrains. Wheeled robots featuring moving on wheels is another structure different than legged robotic structure. It can move faster on flat and less rough terrains than the quadrupeds. For quadruped and wheeled structures, either one can fail to move properly once the terrains are inappropriate. Correspondingly, to have a robotic structure performing well under whatever terrain...

  5. Analysis of the Feasibility and Utility of Radon as a Electrostatic Ion Thruster Propellant

    Barrington, Brennan
    The feasibility of using radon produced through decay of parent isotopes stored as fuel, as propellant in an ion thruster, is evaluated. It was believed that this approach could result in reduction of power consumption, spacecraft mass, and mission time. Analysis is done of discharge loss, power supply through Stirling convertors, propellant separation, cost, and range safety. It was found that the power and mass benefits are relatively small and heavily dependent upon the performance of technology which is not yet available. Further, absent significant improvements in isotope separation methods, the cost would be astronomical (on the order of that...

  6. HCCI engine CFD simulations: Influence of intake temperature, cylinder wall temperature and the equivalence ratio on ignition timing

    Wang, Kezhuo
    To meet the increasingly stringent emission standards, the automotive industry is actively searching for means to improve the efficiency of an internal combustion engine. One promising solution is a homogeneous charge compression ignition (HCCI) engine which has shown potential in achieving high fuel efficiency while maintaining low emission. However, there remain several challenges to commercialize the HCCI engine due to the nature of its working principle. Since the HCCI engine relies purely on compression to achieve ignition, controlling the ignition timing is much harder than in spark-ignition (SI) engines and diesel engines. This study focuses on simulating the ignition and...

  7. Development of LiNi0.5Mn.1.5-xTixO4 as an Advanced Cathode for Lithium-Ion Batteries

    Zhu, Ge
    After their successful application in small electronics, lithium-ion (Li-ion) batteries have been developed in ever larger sizes to support the energy and power requirements needed for electric vehicles (EVs). To further extend the driving distance of EVs at lower cost, there has been extensive research efforts in developing next-generation battery materials with higher energy density. LiNi0.5Mn1.5O4 (LNMO) is a promising cathode material due to its high operating voltage of 4.7 V. However, LNMO has short cycle life issue attributed to its unwanted surficial reactions in contact with liquid electrolytes. As a solution, partial Ti substituting for Mn in LNMO was...

  8. Effect of Molybdenum on Ductility Dip Cracking in Nickel-Base Weld Filler Metal 52XL

    Blados, Stan
    The nuclear industry has an increasing demand for thick cross-section walls from nickel-based alloys for structural and repair applications. Due to the high restraint and residual stresses developing in these welds, ductility dip cracking (DDC) is a major problem, especially when using high chromium nickel-based filler metals. Previous research has shown that alloying elements, such as niobium (Nb) and tantalum (Ta) decrease the susceptibility to DDC by the formation of eutectic carbides along the solidification grain boundaries. These carbides pin the grain boundaries in the weld metal, which results in tortuous grain boundaries causing a mechanical locking effect, so that...

  9. Investigation of Satellite Constellation Configuration for Earth Observation Using Sierra Nevada Dream Chaser Spacecraft

    Steen, Andrew J.
    As the global climate crisis continues to drive extreme weather conditions, the need for increasingly robust systems to deliver unprecedented Earth Observation (EO) data will become a major economic concern for nations worldwide. The need exists for an international open platform for EO that can be utilized by small, less economically or technologically advanced nations for data acquisition as they attempt to deal with environmental disasters. The purpose of this project is therefore to develop an orbital strategy for the construction and utilization of an EO constellation of satellites, using as its platform the Sierra Nevada Corporation’s Dream Chaser® spacecraft...

  10. Characterization of Type I Collagen Fibrillogenesis Using Atomic Force Microscopy

    Du, Zhengyang
    Bone is a 'smart' material adapting its material composition and properties in response to external loading to maintain the mechanical integrity. Thus, understanding the mechanism to control its adaptive behavior is extremely useful not only for improving clinical treatment but also for mimicking its design strategy for boundless engineering applications. As one of the bone's main constituents, collagen type I is the most abundant protein consisting of osseous tissue. The bio-mineralization process of collagen template controls the mechanical stiffness of bone in response to external loading. While the involvement of collagen in the bone mineralization process is widely accepted, its...

  11. Development of a Micro-Scale Motion Capture System for Analysis of Formicidae Biomechanics

    Farou, Sarah
    Previous investigation has determined that ants are able to lift and support loads up to a magnitude of 1,000 times their body weight. The load path through the ant's body passes entirely through the neck, one of the thinnest structures in diameter on the ant, before it is transferred and distributed to the rest of the body. In order to gain a better understanding of the structural and material properties of the neck tissues, previous research was completed utilizing mechanical loading studies and Scanning Electron Microscopy. SEM was utilized to analyze the location of material failure in the transition region...

  12. Analysis of Traffic Related Pollution Through Low Cost Mobile Air Quality Sensors

    van Dommelen, Emma
    Air pollution monitoring is often stationary and expensive, failing to provide easily accessible data in most nearby locations to where people live and work. In an age of technology, it should be possible to obtain this type of information to create a better understanding of health impacts associated with air pollution. The purpose of this investigation and analysis is to create a method of regular low-cost post-process mobile air quality sampling for Ohio State University's (OSU) campus using OSU's bus system, Campus Area Bus Service (CABS), as a mobile platform and locate highly concentrated areas of traffic emissions. These highly...

  13. Parametric Estimation of Crystallographic Texture Using Estimation Maximization

    Ahlborg, Carl
    The properties of materials are functions of their internal structure. Most engineering materials, including metals, are polycrystalline and composed of microscopic crystals. The crystallographic texture, the description of the orientations of the crystallites in a material, is a key structural indicator of the deformation behavior. Estimating the orientation distribution function (ODF) of a sample allows materials scientists to identify the probability a crystal in a sample is oriented in a certain direction. The current process, which employs a Fourier series expansion over a generalized spherical harmonic basis, leaves much to be desired and is poorly understood by much of the...

  14. Multistage Blisk Large Mistuning Modeling Using Fourier Constraint Modes and Pristine Rogue Interface Modal Expansion

    Stahl, Spencer
    In the turbomachinery field, a great deal of research has focused on understanding the effects of mistuning on the dynamics of each stage. Mistuning in bladed disks is due to the blade to blade differences that typically occur due to manufacturing tolerances and in-service wear. Mistuning greatly complicates the modelling of bladed disks since it is inherently random and requires a statistical analysis to be conducted to understand the full dynamics of a bladed disk design. Moreover, mistuning destroys the cyclic symmetry of the bladed disk, which prevents cyclic analysis from being used to model the system. Cyclic analysis enables...

  15. Characterization of Heat Transfer in Serpentine Passages using Thermochromic Liquid Crystals

    Kulkarni, Aditya
    Since the beginning of the 21st century, air travel has increased over 120%, creating a need for more efficient propulsion. Recent innovations in aircraft gas turbine technology have centered around cold section improvements such as geared fans and higher-pressure ratio compressors. However, improvements in the thermodynamic cycle of the engine that push turbine inlet temperatures ever higher remain an instrumental part in improving efficiency for future aircraft. At the Gas Turbine Laboratory (GTL), experiments using engine hardware are performed at scaled conditions to provide a better understanding of the flow physics and heat transfer in the high-pressure turbine section. The...

  16. ENGINEERING SOLID ELECTROLYTE/ELECTRODE INTERFACES FOR ALL SOLID-STATE LITHIUM-ION BATTERY

    Choi, Junbin
    Nowadays, most commercialized portable electronic devices, such as cell-phones and laptops, use Li-ion batteries as their power source. Li-ion batteries are also being used by automotive companies to power electric vehicles (EVs). However, there is a strong need to make Li-ion batteries safer under abusive conditions, such as car accidents. To address this need, significant research has been recently conducted to utilize solid electrolytes in Li-ion battery cells for the next generation EV applications. In this study, I investigated several solid electrolyte and electrode materials to seek their optimal combinations in terms of chemical stabilities at electrolyte – electrode interfaces....

  17. Influence of Substrate Mechanical Properties on Lens Epithelial Cell Behavior

    Allen, Mallory G.
    Posterior capsular opacification (PCO), or secondary cataract, is the most common complication of after cataract surgery, but current clinical solutions are expensive, have complications, and are not available in developing countries. While PCO has been widely studied, little to no research exists to examine the link between mechanical properties of implanted intraocular lenses (IOLs) and occurrence of secondary cataract. The goal of this project was to start to close this scientific gap by measuring mechanical properties of a series of amphiphilic polymers and investigating their impact on lens epithelial cell (LEC) response. Polymers with different levels of crosslinking were synthesized...

  18. Analysis of a Computationally Simulated Three Stream Jet Flow for Noise Mitigation

    Salamon, Nicholas
    The energetic flow that emanates from a jet engine is what propels aircrafts to their destinations, but it is also the source of noise that is harmful to humans. Exposure to high levels of jet noise can cause acute symptoms like hearing loss and sleep disturbances, while prolonged exposure can significantly decrease a person's quality of life. Due to the ubiquity of commercial air transportation, the problem of jet noise and jet noise mitigation is an important area of research. It is believed that jet noise is caused by the process of turbulent mixing between slow ambient air and fast...

  19. Development of Oxygen-Sensitive Electrosprayed Core-shell Polymer Microparticles for Biological Applications

    DiRando, Nicole
    When upconverting nanoparticles (UCNPs) are combined with oxygen-sensitive molecules, oxygen sensing can be achieved upon near-infrared (NIR) excitation. The combination of the oxygen-sensitive molecules and upconverters can be used to show different oxygen concentrations in the body. If there is a large concentration of oxygen, the intensity of the light emitted will be lower compared to if there were less oxygen. The objective of this research is to develop optimal electrosprayed microparticles and to better understand their polymer processing in order to achieve desired properties. Ideally, the particles will result in high brightness and low leaching. The developed microparticles can...

  20. Indirect Magnetic Force Microscopy - A Multimodal Technique

    Novinc, Rachel
    Magnetic micro- and nano-particles are widely used for labeling cells and tissues and for magneto-separation of biomolecules. Current approaches to detect these particles are limited to an ensemble of particles with poor spatial resolution at the single particle level. In this study we demonstrate how magnetism based microscopy can be utilized for detection of magnetic micro-particles in a label-free and multimodal manner. Earlier work from our laboratory had demonstrated how the atomic force microscopy (AFM) based technique, magnetic force microscopy (MFM), can map magnetic nano-particles and ferritin protein at nanoscale resolution. MFM has thus far been performed using direct MFM...

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