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Interplay Of Molecular And Nanoscale Behaviors In Biological Soft Matter, Nicholas Ciaffone
Interplay Of Molecular And Nanoscale Behaviors In Biological Soft Matter, Nicholas Ciaffone
Electronic Theses and Dissertations
The complexity of biological soft matter at the sub-micrometer level is fundamentally correlated to the functionalities at the larger scale. Reflecting the level of heterogeneities in the properties of systems remains challenging when probing small scales, due to the mismatch between the area surveyed with the tools offering nanoscale resolution, such as atomic force microscopy (AFM), and the scale of natural variations inherent to biology. Hence, to understand the physiological and mechanical alterations that occur within a single cell relative to a cell population, a multiscale approach is necessary. In this work we show that it is possible to observe …
The Relationship Between Agile Project Management And Project Success Outcomes, Thomas Bergmann
The Relationship Between Agile Project Management And Project Success Outcomes, Thomas Bergmann
Electronic Theses and Dissertations
Agile project management (APM) has recently emerged as a new approach to managing complex projects. Some experts believe that APM will become the standard project management approach used in the 21st century. However, thus far, the role of agility in project management has not been widely investigated. In the recent past, the concept of agility has mainly been applied to software development projects. The literature on agility is still in its early stages, and further research needs to be conducted in new project management domains. This study is intended to determine the impact of the adoption of APM on project …
Experimental Investigation Of Advanced Ignition Systems For High Efficiency Combustion, Bader Almansour
Experimental Investigation Of Advanced Ignition Systems For High Efficiency Combustion, Bader Almansour
Electronic Theses and Dissertations
Consumption of fossil and bio-derived fuels is growing due to energy demands associated with increase in population and standard of living across the globe. Power generation and transportation sectors are the primary two sources of fuel consumption, which have raised the demand for crude oil and led to serious environmental pollution issues. This demand for energy forced various government agencies to strengthen the allowable exhaust pollutant concentration limits. Recently, CO, CO2, particulate matter, and nitrogen oxides (NOx) emission restrictions have become more stringent to the extent that engines must operate at higher energy densities and efficiencies. Towards this goal, this …
A Holistic Analysis Of The Long-Term Challenges & Potential Benefits Of The Green Roof, Solar Pv Roofing, And Gripv Roofing Markets In Orlando, Florida, Carolina Kelly
Electronic Theses and Dissertations
Green roofs and roof-mounted solar PV arrays have a wide range of environmental and economic benefits, including significantly longer roof lifetimes, reductions in urban runoff, mitigation of the urban heat island (UHI) effect, reduced electricity demand and energy dependence, and/or reduced emissions of greenhouse gases (GHGs) and other harmful pollutants from the electricity generation sector. Consequently, green roofs and solar panels have both become increasingly popular worldwide, and promising new research has emerged for their potential combination in Green Roof Integrated Photovoltaic (GRIPV) roofing applications. However, due to policy resistance, these alternatives still have marginal market shares in the U.S., …
Development Of A Tabletop Coherent Soft X-Ray Source, Hanfu Kong
Development Of A Tabletop Coherent Soft X-Ray Source, Hanfu Kong
Electronic Theses and Dissertations
The goal of this thesis is to design a tabletop coherent soft X-ray source for attosecond high resolution imaging. We collect signals from gas cells with different length and lens with different focal length. A spectrometer with a grating and a CCD camera is applied to observe and measure the spectrum of the X-ray attosecond pulses. This thesis first introduces the theory background of ultrafast lasers, then mainly explains high harmonic generation, which is the key method for attosecond pulses generation, subsequently presents the experiment system and analyzes the results from the experiment, also compares different combinations of parameters of …
Regolith-Based Construction Materials For Lunar And Martian Colonies, Kevin Grossman
Regolith-Based Construction Materials For Lunar And Martian Colonies, Kevin Grossman
Electronic Theses and Dissertations
Humankind's ambitions of exploring our solar system and parts beyond depend heavily on our ability to collect resources from local environments at our destinations rather than bringing materials on the journey. This is a concept known as in-situ resource utilization (ISRU) and it is one that has been understood by every explorer and settler in the history of humankind. Regolith on the moon and Mars has been shown to be a particularly useful resource and has the ability to provide humans with resources including water, oxygen, construction material, fabric, radiation shielding, metals, and may more. This dissertation focuses on construction …
Seepage And Stability Analysis Of The Earth Dams Under Drawdown Conditions By Using The Finite Element Method, Salama Al-Labban
Seepage And Stability Analysis Of The Earth Dams Under Drawdown Conditions By Using The Finite Element Method, Salama Al-Labban
Electronic Theses and Dissertations
One of the major concerns in the behavior of an earth dam is the change in the exit gradient and the impact on the slope stability under drawdown conditions. Drawdown can cause increased seepage forces on the upstream slope which may result in the movement of soil particles in the flow direction and cause erosion problems. In this research, a numerical approach, based on the finite element method (FEM) is used to analyze the seepage through the dam and its foundation to study exit gradients and slope stability under both steady-state and transient conditions. The results show that a central …
Energy-Optimal Guidance Of An Auv Under Flow Uncertainty And Fluid-Particle Interaction, Demuni Singith De Zoysa Abeysiriwardena
Energy-Optimal Guidance Of An Auv Under Flow Uncertainty And Fluid-Particle Interaction, Demuni Singith De Zoysa Abeysiriwardena
Electronic Theses and Dissertations
The work presented gives an energy-optimal solution to the guidance problem of an AUV. The presented guidance methods are for lower level control of AUV paths, facilitating existing global planning methods to be carried out comparatively more efficiently. The underlying concept is to use the energy of fluid flow fields the AUVs are navigating to extend the duration of missions. This allows gathering of comparatively more data with higher spatio-temporal resolution. The problem is formulated for a generalized two dimensional uniform flow field given a fixed final time and free end states. This allows the AUVs to navigate to certain …
Turbulent Flame-Vortex Dynamics Of Bluff-Body Premixed Flames, Marissa Geikie
Turbulent Flame-Vortex Dynamics Of Bluff-Body Premixed Flames, Marissa Geikie
Electronic Theses and Dissertations
This study explores the effects of turbulence and pressure-gradient tailoring on the turbulent flame and vorticity transport mechanisms of premixed flames. A turbulent premixed flame stabilized by a bluff-body in a high-speed combustor is used for the investigation. The combustor pressure gradient is altered using a variable-geometry test section. The turbulence within the combustor is controlled using a custom-designed, supersonic variable-turbulence generator. The turbulent flame-flow field is measured and characterized using simultaneous high-speed particle imaging velocimetry (PIV) and CH* chemiluminescence. The flame-vortex dynamics of the turbulent flame are analyzed using a Lagrangian tracking methodology. Lagrangian fluid elements (LFEs) are tagged …
Bio-Inspired Visual Servo Control Of A Picking Mechanism In An Agricultural Ground Robot, Sinem Gozde Defterli
Bio-Inspired Visual Servo Control Of A Picking Mechanism In An Agricultural Ground Robot, Sinem Gozde Defterli
Electronic Theses and Dissertations
For a recently constructed disease detection agricultural ground robot, the segregation of unhealthy leaves from strawberry plants is a major task of the robot's manipulation subsystem in field operations. In this dissertation, the motion planning of a custom-designed picking mechanism in the ground robot's subsystem is studied in two sections. First, a set of analytical, suboptimal semi-analytical and numerical algorithms are studied to solve the inverse kinematics problem of the handling mechanism in firm circumstances. These premeditated approaches are built on the computation of the joint variables by an identified 3D position data of the target leaf only. The outcomes …
Design Of High Efficiency Brushless Permanent Magnet Machines And Driver System, Chengyuan He
Design Of High Efficiency Brushless Permanent Magnet Machines And Driver System, Chengyuan He
Electronic Theses and Dissertations
The dissertation is concerned with the design of high-efficiency permanent magnet synchronous machinery and the control system. The dissertation first talks about the basic concept of the permanent magnet synchronous motor (PMSM) design and the mathematics design model of the advanced design method. The advantage of the design method is that it can increase the high load capacity at no cost of increasing the total machine size. After that, the control method of the PMSM and Permanent magnet synchronous generator (PMSG) is introduced. The design, simulation, and test of a permanent magnet brushless DC (BLDC) motor for electric impact wrench …
Harmful Algal Bloom Mitigating Using Recycled Concrete Aggregate Coated With Fixed-Quat., Ikenna Ezeodurukwe
Harmful Algal Bloom Mitigating Using Recycled Concrete Aggregate Coated With Fixed-Quat., Ikenna Ezeodurukwe
Electronic Theses and Dissertations
Human activities generate surplus nutrients which may lead to algal bloom events in water resources along with serious ecological problems and thus substantial economic losses. Particularly, harmful algal blooms (HABs) represent toxic cyanobacterial blooms which produce cyanotoxins. The primary concerns of HABs are the exposures to a wide variety of cyanotoxins via ingestion of contaminated drinking water, inhalation during recreational activities, and consumption of contaminated fish and shellfish. However, conventional physical and chemical methods are not always possible to efficiently handle these HABs events. It is urgent to develop viable and rapid solutions to control HABs in field and mitigate …
Fast Compressed Automatic Target Recognition For A Compressive Infrared Imager, Brian Millikan
Fast Compressed Automatic Target Recognition For A Compressive Infrared Imager, Brian Millikan
Electronic Theses and Dissertations
Many military systems utilize infrared sensors which allow an operator to see targets at night. Several of these are either mid-wave or long-wave high resolution infrared sensors, which are expensive to manufacture. But compressive sensing, which has primarily been demonstrated in medical applications, can be used to minimize the number of measurements needed to represent a high-resolution image. Using these techniques, a relatively low cost mid-wave infrared sensor can be realized which has a high effective resolution. In traditional military infrared sensing applications, like targeting systems, automatic targeting recognition algorithms are employed to locate and identify targets of interest to …
The Formation And Characterization Of Mesoscopic J- And H-Aggregates With Controlled Morphologies By The Co- And Templated Assembly Of Cyanine Dyes, Samuel Rhodes
Electronic Theses and Dissertations
The supramolecular aggregates of π-conjugated molecules have become an area of great interest to the scientific community in recent years for their promise in biosensors and optoelectronic devices. Among various supramolecular aggregates, J- and H-aggregates of πconjugated dye molecules are particularly interesting because of their unique optical and excitonic properties that are not given by individual molecules. H-aggregates are composed of dye molecules in a face-to-face stacking, giving rise to a blue-shifted absorption band compared with the monomer band and a strong emission quenching. In contrast, J-aggregates represent an edge-toedge stacking of dye molecules, showing a red-shifted absorption band with …
Influence Of Chitosan-Alginate Scaffold Stiffness On Bone Marrow Stromal Cell Differentiation, Isabel Arias Ponce
Influence Of Chitosan-Alginate Scaffold Stiffness On Bone Marrow Stromal Cell Differentiation, Isabel Arias Ponce
Electronic Theses and Dissertations
Tissue grafts are the gold standard for replacing large volume tissue defects. Yet, they present several risks, including infection, low functional outcomes, and reduced graft integrity. Tissue engineering (TE) combines cells and biomaterial scaffolds to foster tissue growth and remodeling. Bone marrow stromal cells (BMSCs) have been shown to respond to the stiffness of their microenvironment, resulting in differentiation into different lineages. 3D porous chitosan-alginate (CA) scaffolds have been previously demonstrated for bone TE with osteoblasts and BMSCs; however, only a single scaffold composition (4 wt%) was studied. Three CA scaffold compositions (2, 4, 6 wt% CA) were produced. Scanning …
Navigation Of An Autonomous Differential Drive Robot For Field Scouting In Semi-Structured Environments, Douglas Freese
Navigation Of An Autonomous Differential Drive Robot For Field Scouting In Semi-Structured Environments, Douglas Freese
Electronic Theses and Dissertations
In recent years, the interests of introducing autonomous robots by growers into agriculture fields are rejuvenated due to the ever-increasing labor cost and the recent declining numbers of seasonal workers. The utilization of customized, autonomous agricultural robots has a profound impact on future orchard operations by providing low cost, meticulous inspection. Different sensors have been proven proficient in agrarian navigation including the likes of GPS, inertial, magnetic, rotary encoding, time of flight as well as vision. To compensate for anticipated disturbances, variances and constraints contingent to the outdoor semi-structured environment, a differential style drive vehicle will be implemented as an …
Investigation Into The Feasibility Of Adding Turbulators To Rocket Combustion Chamber Cooling Channels Using A Conjugate Heat Transfer Analysis, Tyler Buchanan
Investigation Into The Feasibility Of Adding Turbulators To Rocket Combustion Chamber Cooling Channels Using A Conjugate Heat Transfer Analysis, Tyler Buchanan
Electronic Theses and Dissertations
A conjugate heat transfer analysis will be carried out to simulate an 89 kN thrust chamber hydrogen cooling channel, to determine the feasibility of adding turbulators to the combustion chamber cooling channels at various parameters such as angle, pitch, and height of the turbulator. An existing regeneratively cooled chamber environment is simulated and used as a baseline case to be compared against. The new design includes using ribbed turbulators or delta wedges in the cooling channels to increase the heat transfer on the channel hot wall (wall adjacent to the hot gas wall) and on the two channel sidewalls. With …
Non-Hermitian Optics, Absar Ulhassan
Non-Hermitian Optics, Absar Ulhassan
Electronic Theses and Dissertations
From the viewpoint of quantum mechanics, a system must always be Hermitian since all its corresponding eigenvalues must be real. In contrast, the eigenvalues of open systems-unrestrained because of either decay or amplification-can be in general complex. Not so long ago, a certain class of non-Hermitian Hamiltonians was discovered that could have a completely real eigenvalue spectrum. This special class of Hamiltonians was found to respect the property of commutation with the parity-time (PT) operator. Translated into optics, this implies a balance between regions exhibiting gain and loss. Traditionally, loss has been perceived as a foe in optics and something …
High Quality Gate Dielectric/Mos2 Interfaces Probed By The Conductance Method, Adithi Pandrahal Krishnaprasad Sharada
High Quality Gate Dielectric/Mos2 Interfaces Probed By The Conductance Method, Adithi Pandrahal Krishnaprasad Sharada
Electronic Theses and Dissertations
Two-dimensional materials provide a versatile platform for various electronic and optoelectronic devices, due to their uniform thickness and pristine surfaces. We probe the superior quality of 2D/2D and 2D/3D interfaces by fabricating molybdenum disulfide (MoS2)-based field effect transistors having hexagonal boron nitride (h-BN) and Al2O3 as the top gate dielectrics. An extremely low trap density of ~7x10^10 states/cm2-eV is extracted at the 2D/2D interfaces with h-BN as the top gate dielectric on the MoS2 channel. 2D/3D interfaces with Al2O3 as the top gate dielectric and SiOx as the nucleation layer exhibit trap densities between 7x10^10 and 10^11 states/cm2-eV, which is …
Equivalency Analysis Of Sidestick Controller Modes During Manual Flight, Alex Rummel
Equivalency Analysis Of Sidestick Controller Modes During Manual Flight, Alex Rummel
Electronic Theses and Dissertations
Equivalency analysis is a statistical procedure that can enhance the findings of an analysis of variance in the case when non-significant differences are identified. The demonstration of functional equivalence or the absence of practical differences is useful to designers introducing new technologies to the flight deck. Proving functional equivalence is an effective means to justify the implementation of new technologies that must be "the same or better" than previous technology. This study examines the functional equivalency of three operational modes of a new active control sidestick during normal operations while performing manual piloting tasks. Data from a between-subjects, repeated-measures simulator …
Mechanisms Of Flame Extinction For Bluff Body Stabilized Flames With Influences Of Pressure Gradient Tailoring, Anthony Morales
Mechanisms Of Flame Extinction For Bluff Body Stabilized Flames With Influences Of Pressure Gradient Tailoring, Anthony Morales
Electronic Theses and Dissertations
Flame extinction continues to hinder the performance of combustion technologies used in propulsion systems and power generating turbomachinery. Within these applications, there is a crucial need to improve energy output while minimizing harmful environmental impacts. Lean combustion helps attain these goals by minimizing fuel costs and reducing NOx emissions. However, operating at lean conditions increases the likelihood of flame extinction; the flame becomes more susceptible to hydrodynamic instabilities which can induce global blowout and termination of the combustion process. The work in this thesis is focused on identifying the mechanisms of flame extinction and controlling these mechanisms via pressure gradient …
Power Scaling Of High Power Solid State Lasers., Bumjin Oh
Power Scaling Of High Power Solid State Lasers., Bumjin Oh
Electronic Theses and Dissertations
The solid-state laser is one of the most widely used lasers in scientific research and industrial applications. This thesis describes detailed investigations of two modern architectures of high power cw solid-state lasers, a 20 W diode-pumped Yb:YAG thin disc laser and 300 W diode-pumped Nd:YAG rod laser. With the thin disc laser architecture, the signal beam must fit to the pump area on the disc defined by the multi-pass diode pump configuration. The beam propagation, beam diameter, phase and thermal effects for various cavity configurations are investigated theoretically and experimentally. In addition, the internal loss, small signal gain, and thermal …
Dynamic Hotspot Identification For Limited Access Facilities Using Temporal Traffic Data, Samer Al Amili
Dynamic Hotspot Identification For Limited Access Facilities Using Temporal Traffic Data, Samer Al Amili
Electronic Theses and Dissertations
Crash frequency analysis is the most critical tool to investigate traffic safety problems. Therefore, an accurate crash analysis must be conducted. Since traffic continually fluctuates over time and this effects potential of crash occurrence, shorter time periods and less aggregated traffic factors (shorter intervals than AADT) need to be used. In this dissertation, several methodologies have been conducted to elevate the accuracy of crash prediction. The performance of using less aggregated traffic data in modeling crash frequency was explored for weekdays and weekends. Four-time periods for weekdays and two time periods for weekends, with four intervals (5, 15, 30, and …
Joint Optimization Of Illumination And Communication For A Multi-Element Vlc Architecture, Sifat Ibne Mushfique
Joint Optimization Of Illumination And Communication For A Multi-Element Vlc Architecture, Sifat Ibne Mushfique
Electronic Theses and Dissertations
Because of the ever increasing demand wireless data in the modern era, the Radio Frequency (RF) spectrum is becoming more congested. The remaining RF spectrum is being shrunk at a very heavy rate, and spectral management is becoming more difficult. Mobile data is estimated to grow more than 10 times between 2013 and 2019, and due to this explosion in data usage, mobile operators are having serious concerns focusing on public Wireless Fidelity (Wi-Fi) and other alternative technologies. Visible Light Communication (VLC) is a recent promising technology complementary to RF spectrum which operates at the visible light spectrum band (roughly …
Investigating And Facilitating The Transferability Of Safety Performance Functions, Ahmed Tarek Ahmed Farid
Investigating And Facilitating The Transferability Of Safety Performance Functions, Ahmed Tarek Ahmed Farid
Electronic Theses and Dissertations
Safety performance functions (SPFs) are essential analytical tools in the road safety field. The SPFs are statistical regression models used to predict crash counts by roadway facility type, crash type and severity. The national Highway Safety Manual (HSM) is a generic guidebook used for road safety evaluation and enhancement. In it, default SPFs, developed using negative binomial (NB) regression, are provided for multiple facility types and crash categories. Roadway agencies, whether public or private, may opt to not invest their resources in data collection and processing to develop own localized SPFs. Instead, the agencies may adopt the HSM's. However, the …
Hierarchical Corridor Safety Analysis Using Multiple Approaches, Saif Alarifi
Hierarchical Corridor Safety Analysis Using Multiple Approaches, Saif Alarifi
Electronic Theses and Dissertations
Traffic crashes are a major cause of concern globally. Extensive efforts from transportation professionals have been made to investigate new methods to identify the contributing factors to crashes at various locations on the road network. Corridors, among other road network's components, play a vital role in moving people and goods between primary zones in different areas, and the safety and operational improvements of them have been the focus of many studies since they carry the most traffic on the road network. Corridors contain mainly intersections and segments, and previous corridor studies have focused on a sole type of road entity. …
Fiber Optimization For Operation Beyond Transverse Mode Instability Limitations, Joshua Bradford
Fiber Optimization For Operation Beyond Transverse Mode Instability Limitations, Joshua Bradford
Electronic Theses and Dissertations
Transverse Mode Instabilities (TMIs) stand as a fundamental limitation to power and brightness scaling in laser systems based upon optical fiber technologies. This work comprises experimental and theoretical investigations into fiber laser design that should minimize the effects of Stimulated Thermal Rayleigh Scattering. Theoretical discussions and simulations focus on how fiber parameters affect transverse mode coupling. These include core geometry optimization, pump geometry optimization, in addition to the effects of HOM content and losses on the TMI threshold. Experimentally, a high-power laser facility is commissioned with beam quality diagnostics to quantify the thresholds of the onset of modal interferences and …
A Game-Theoretic Model For Regulating Freeriding In Subsidy-Based Pervasive Spectrum Sharing Markets, Mostafizur Rahman
A Game-Theoretic Model For Regulating Freeriding In Subsidy-Based Pervasive Spectrum Sharing Markets, Mostafizur Rahman
Electronic Theses and Dissertations
Cellular spectrum is a limited natural resource becoming scarcer at a worrisome rate. To satisfy users' expectation from wireless data services, researchers and practitioners recognized the necessity of more utilization and pervasive sharing of the spectrum. Though scarce, spectrum is underutilized in some areas or within certain operating hours due to the lack of appropriate regulatory policies, static allocation and emerging business challenges. Thus, finding ways to improve the utilization of this resource to make sharing more pervasive is of great importance. There already exists a number of solutions to increase spectrum utilization via increased sharing. Dynamic Spectrum Access (DSA) …
Compressible Turbulent Flame Speed Of Highly Turbulent Standing Flames, Jonathan Sosa
Compressible Turbulent Flame Speed Of Highly Turbulent Standing Flames, Jonathan Sosa
Electronic Theses and Dissertations
This work presents the first measurement of turbulent burning velocities of a highly-turbulent compressible standing flame induced by shock-driven turbulence in a Turbulent Shock Tube. High-speed schlieren, chemiluminescence, PIV, and dynamic pressure measurements are made to quantify flame-turbulence interaction for high levels of turbulence at elevated temperatures and pressure. Distributions of turbulent velocities, vorticity and turbulent strain are provided for regions ahead and behind the standing flame. The turbulent flame speed is directly measured for the high-Mach standing turbulent flame. From measurements of the flame turbulent speed and turbulent Mach number, transition into a non-linear compressibility regime at turbulent Mach …
Robust, Scalable, And Provable Approaches To High Dimensional Unsupervised Learning, Mostafa Rahmani
Robust, Scalable, And Provable Approaches To High Dimensional Unsupervised Learning, Mostafa Rahmani
Electronic Theses and Dissertations
This doctoral thesis focuses on three popular unsupervised learning problems: subspace clustering, robust PCA, and column sampling. For the subspace clustering problem, a new transformative idea is presented. The proposed approach, termed Innovation Pursuit, is a new geometrical solution to the subspace clustering problem whereby subspaces are identified based on their relative novelties. A detailed mathematical analysis is provided establishing sufficient conditions for the proposed method to correctly cluster the data points. The numerical simulations with both real and synthetic data demonstrate that Innovation Pursuit notably outperforms the state-of-the-art subspace clustering algorithms. For the robust PCA problem, we focus on …