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Theses and Dissertations

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Articles 5281 - 5310 of 11510

Full-Text Articles in Engineering

Cooperative Estimation For A Vision-Based Multiple Target Tracking System, Joshua Y. Sakamaki Jun 2016

Cooperative Estimation For A Vision-Based Multiple Target Tracking System, Joshua Y. Sakamaki

Theses and Dissertations

In this thesis, the Recursive-Random Sample Consensus (R-RANSAC) algorithm is applied to a vision-based, cooperative target tracking system. Unlike previous applications, which focused on a single camera platform tracking targets in the image frame, this work uses multiple camera platforms to track targets in the inertial or world frame. The process of tracking targets in the inertial frame is commonly referred to as geolocation.In practical applications sensor biases cause the geolocated target estimates to be biased from truth. The method for cooperative estimation developed in this thesis first estimates the relative rotational and translational biases that exist between tracks from …

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Typical And Darkened Portland Cement Concrete Pavement: Temperature, Moisture, And Roughness Analyses, Tenli Waters Jun 2016

Typical And Darkened Portland Cement Concrete Pavement: Temperature, Moisture, And Roughness Analyses, Tenli Waters

Theses and Dissertations

The objectives of this research were to 1) investigate the effects of lower concrete albedo on the thermal behavior of concrete pavement by directly comparing temperatures and moisture contents of typical and darkened concrete pavements and 2) investigate changes in roughness of both typical and darkened concrete pavements as a result of changes in temperature and moisture gradients. The scope of the research included instrumentation, testing, and analysis of typical and darkened concrete pavements constructed in northern Utah.Procedures related to field testing included infrared thermography, thermocouple readings, sensor data collection, and roughness surveys. Elevation surveys and albedo measurements were also …

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Modeling And Control Of A Tailsitter With A Ducted Fan, Matthew Elliott Argyle Jun 2016

Modeling And Control Of A Tailsitter With A Ducted Fan, Matthew Elliott Argyle

Theses and Dissertations

There are two traditional aircraft categories: fixed-wing which have a long endurance and a high cruise airspeed and rotorcraft which can take-off and land vertically. The tailsitter is a type of aircraft that has the strengths of both platforms, with no additional mechanical complexity, because it takes off and lands vertically on its tail and can transition the entire aircraft horizontally into high-speed flight. In this dissertation, we develop the entire control system for a tailsitter with a ducted fan. The standard method to compute the quaternion-based attitude error does not generate ideal trajectories for a hovering tailsitter for some …

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Novel Techniques For Rapid Cardiac Perfusion Magnetic Resonance Imaging With Whole Heart Coverage, Haonan Wang Jun 2016

Novel Techniques For Rapid Cardiac Perfusion Magnetic Resonance Imaging With Whole Heart Coverage, Haonan Wang

Theses and Dissertations

Magnetic Resonance Imaging (MRI) is a non-invasive medical imaging method that is used in the diagnosis of many common diseases. Compared to other medical imaging modalities, MRI has the ability to provide high-resolution 2D and 3D images in arbitrary orientations, without the use of potentially damaging ionizing radiation. Myocardial perfusion MRI is a promising non- invasive clinical way to detect cardiac disease. It can also provide quantitative analysis for blood flow within the heart. However, MRI requires longer scan times to acquire images at comparable resolutions to some other imaging modalities. Increasing image resolution, both spatially and temporally, is very …

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Jezik: A Cognitive Translation System Employing A Single, Visible Spectrum Tracking Detector, Davor Bzik Jun 2016

Jezik: A Cognitive Translation System Employing A Single, Visible Spectrum Tracking Detector, Davor Bzik

Theses and Dissertations

A link between eye movement mechanics and the mental processing associated with text reading has been established in the past. The pausing of an eye gaze on a specific word within a sentence reflects correctness or fluency of a translated text. A cognitive translation system has been built employing a single, inexpensive web camera without the use of infrared illumination. It was shown that the system translates the text, detects rarely occurring and out-of-context words from eye gaze information, and provides solutions in real time while the user is still reading. The solutions are in form of a translation, definition …

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Thermal And Convective Loading Methods For Releasing Hydrophobic Therapeutics From Contact Lenses, Ryan Ruben Horne Jun 2016

Thermal And Convective Loading Methods For Releasing Hydrophobic Therapeutics From Contact Lenses, Ryan Ruben Horne

Theses and Dissertations

This thesis investigates the feasibility of loading silicone hydrogel (SiHy) contact lenses with two different hydrophobic therapeutics, latanoprost and DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine), for treatment of glaucoma and hyperemia respectively. The two methods of loading were 1) thermal loading in an aqueous medium and 2) convective loading in a solution of n-propanol. Dailies Total1® lenses prepared in this manner were tested for their loading and their release into artificial tears. Continuous release over 1-4 days at therapeutic levels is achievable from thermal loading of DMPC, convective loading of DMPC, and convective loading of latanoprost. The DMPC loading processes can be naturally integrated …

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A Quantitative Approach To The Identification And Prediction Of Supply Chain Agility, David A. Sheffield Jun 2016

A Quantitative Approach To The Identification And Prediction Of Supply Chain Agility, David A. Sheffield

Theses and Dissertations

As the product-release cycle in the tech industry speeds up, there is more pressure on manufacturers to bring new products to market faster than ever. This puts a great deal of pressure on the suppliers of capital equipment used to manufacture these tech products. The supply chain agility of these suppliers is increasingly important. The purpose of this study is three-fold (1) to develop a methodology that can be used by any firm for measuring and ranking the agility of suppliers and finding the root causes of supplier agility, (2) to develop the first-ever fully quantitative measure of supply chain …

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Dynamic Liquefied Natural Gas (Lng) Processing With Energy Storage Applications, Farhad Fazlollahi Jun 2016

Dynamic Liquefied Natural Gas (Lng) Processing With Energy Storage Applications, Farhad Fazlollahi

Theses and Dissertations

The cryogenic carbon capture™ (CCC) process provides energy- and cost-efficient carbon capture and can be configured to provide an energy storage system using an open-loop natural gas (NG) refrigeration system, which is called energy storing cryogenic carbon capture (CCC-ES™). This investigation focuses on the transient operation and especially on the dynamic response of this energy storage system and explores its efficiency, effectiveness, design, and operation. This investigation included four tasks.The first task explores the steady-state design of four different natural gas liquefaction processes simulated by Aspen HYSYS. These processes differ from traditional LNG process in that the CCC process vaporizes …

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Investigation Of Structural Capacity Of Geogrid-Reinforced Aggregate Base Materials In Flexible Pavements, Eric J. Sweat Jun 2016

Investigation Of Structural Capacity Of Geogrid-Reinforced Aggregate Base Materials In Flexible Pavements, Eric J. Sweat

Theses and Dissertations

The installation of geogrid as a means of extending the service life of a roadway or reducing the required base course thickness of a pavement structure has become increasingly popular. The realization of these benefits depends largely on the degree to which the geogrid reinforcement leads to an increase in the stiffness of the aggregate base course layer. The objective of this research was to investigate the structural capacity of geogrid-reinforced aggregate base materials in flexible pavements through full-scale testing. The scope involved field testing at two sites in northern Utah that each included five different geogrid-reinforced sections and five …

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Quantifying Computer Vision Model Quality Using Various Processing Techniques, Samantha Anna Ruggles Jun 2016

Quantifying Computer Vision Model Quality Using Various Processing Techniques, Samantha Anna Ruggles

Theses and Dissertations

Recently, the use of unmanned aerial vehicles (UAVs) has increased in popularity across several industries. Most notable, however, is the impact that this technology has had in research at academic institutions worldwide. As the technology for UAVs has improved, with that comes easier to operate, more accessible equipment. UAVs have been used in various types of applications and are quickly becoming a preferred method of studying and analyzing a site. Currently, the most common use of a UAV is to monitor a location of interest to a researcher that is difficult to gain access to otherwise. The UAV can be …

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Nerve Regeneration Using Lysophosphatidylcholine And Nerve Growth Factor, Ryan Lavar Wood Jun 2016

Nerve Regeneration Using Lysophosphatidylcholine And Nerve Growth Factor, Ryan Lavar Wood

Theses and Dissertations

Peripheral nerve damage affects hundreds of thousands of people every year. This study tested the effectiveness of using lysophosphatidylcholine (LPC) in combination with nerve growth factor (NGF) to increase the healing rate of damaged left sciatic nerves in female rats. The rats were randomly divided into eight groups: Sham, Right Sciatic, Crush, LPC, LPC-NGF, Crush- LPC, Crush-NGF, and Crush-LPC-NGF. The healing of the nerves was measured by monitoring gait, electrophysiological parameters (compound muscle action potential amplitudes and nerve conductance velocities) and morphological parameters (total fascicular area, total myelinated fiber counts, fiber densities, fiber diameters, and g-ratio). Gait and electrophysiological parameters …

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Design And Analysis Of Two Compliant Mechanism Designs For Use In Minimally Invasive Surgical Instruments, Jason Lon Dearden Jun 2016

Design And Analysis Of Two Compliant Mechanism Designs For Use In Minimally Invasive Surgical Instruments, Jason Lon Dearden

Theses and Dissertations

Minimally invasive surgery (MIS) has several advantages over traditional methods. Scaling MIS instruments to smaller sizes and increasing their performance will enable surgeons to offer new procedures to a wider range of patients. In this work, two compliant mechanism-based minimally invasive surgical instrument wrist or gripper mechanisms are designed and analyzed.The cylindrical cross-axis flexural pivot (CCAFP) is a single-degree-of-freedom wrist mechanism that could be combined with existing gripper mechanisms to create a multi-degree-of freedom instrument. The simplicity of the CCAFP mechanism facilitates analysis and implementation. The flexures of the CCAFP are integral with the instrument shaft, enabling accessories to be …

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Implementations Of Fourier Methods In Cfd To Analyze Distortion Transfer And Generation Through A Transonic Fan, Marshall Warren Peterson Jun 2016

Implementations Of Fourier Methods In Cfd To Analyze Distortion Transfer And Generation Through A Transonic Fan, Marshall Warren Peterson

Theses and Dissertations

Inlet flow distortion is a non-uniform total pressure, total temperature, or swirl (flow angularity) condition at an aircraft engine inlet. Inlet distortion is a critical consideration in modern fan and compressor design. This is especially true as the industry continues to increase the efficiency and operating range of air breathing gas turbine engines. The focus of this paper is to evaluate the Computational Fluid Dynamics (CFD) Harmonic Balance (HB) solver in STAR-CCM+ as a reduced order method for capturing inlet distortion as well as the associated distortion transfer and generation. New methods for quantitatively describing and analyzing distortion transfer and …

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Friction Bit Joining Of Dissimilar Combinations Of Gadp 1180 Steel And Aa 7085 – T76 Aluminum, Lorne Steele Atwood Jun 2016

Friction Bit Joining Of Dissimilar Combinations Of Gadp 1180 Steel And Aa 7085 – T76 Aluminum, Lorne Steele Atwood

Theses and Dissertations

Friction Bit Joining (FBJ) is a method used to join lightweight metals to advanced high-strength steels (AHSS). The automotive industry is experiencing pressure to improve fuel efficiency in their vehicles. The use of AHSS and aluminum will reduce vehicle weight which will assist in reducing fuel consumption. Previous research achieved joint strengths well above that which was required in three out of the four standard joint strength tests using DP980 AHSS and 7075 aluminum. The joints were mechanically tested and passed the lap-shear tension, cross-tension, and fatigue cycling tests. The t-peel test configuration never passed the minimum requirements. The purpose …

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Heteromorphic To Homeomorphic Shape Match Conversion Toward Fully Automated Mesh Morphing To Match Manufactured Geometry, Robert Ivan Yorgason Jun 2016

Heteromorphic To Homeomorphic Shape Match Conversion Toward Fully Automated Mesh Morphing To Match Manufactured Geometry, Robert Ivan Yorgason

Theses and Dissertations

The modern engineering design process includes computer software packages that require approximations to be made when representing geometries. These approximations lead to inherent discrepancies between the design geometry of a part or assembly and the corresponding manufactured geometry. Further approximations are made during the analysis portion of the design process. Manufacturing defects can also occur, which increase the discrepancies between the design and manufactured geometry. These approximations combined with manufacturing defects lead to discrepancies which, for high precision parts, such as jet engine compressor blades, can affect the modal analysis results. In order to account for the manufacturing defects during …

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Reservoir Sedimentation: The Economics Of Sustainability, Matthew William George Jun 2016

Reservoir Sedimentation: The Economics Of Sustainability, Matthew William George

Theses and Dissertations

Despite mounting demand for a more sustainable worldwide water supply system, available reservoir capacity is relentlessly diminishing due to sedimentation. This fact, coupled with a decrease in the rate of dam construction, indicate an impending water supply dilemma. In the future, dams should be designed following a life cycle management approach rather than the typical short-sighted design life technique.Neither sustainable reservoir lifespans nor intergenerational equity is achieved through conventional cost-benefit analyses (CBA), which render all benefits and costs projected to occur more than several decades into a project as negligible. Consequently, future expenditures, including dam decommissioning or retrofitting with sediment …

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Intermediary System Using Image Classification For Online Shopping, Yunan Liu Jun 2016

Intermediary System Using Image Classification For Online Shopping, Yunan Liu

Theses and Dissertations

Online shopping is becoming a popular option for consumers. Currently, the most common product searching method that online shopping websites provide is keyword search. Most shoppers have to carefully select relevant keywords to search for their favorite products. Finding desired products using a query image for online shopping is currently not available. Image has been used for searching similar images in the database but they are usually not well annotated. Research effort has been devoted to developing reliable image-based retrieval systems for applications such as medical image retrieval and trademark search. None of these developments focuses on improving online shopping …

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Calibration Of Rapidscat Over-Land Σ0, Forrest Dayton Minor Jun 2016

Calibration Of Rapidscat Over-Land Σ0, Forrest Dayton Minor

Theses and Dissertations

RapidScat is a Ku-band radar that measures the normalized backscatter coefficient σ0 of the Earth's surface. Launched in 2015, it currently operates on the International Space Station. Nearly one year into its mission, RapidScat measurements began exhibiting strange behavior that is believed to be caused by a change in receiver gain. Changes in gain are compensated for during post-processing, but the measurements have a lower signal-to-noise ratio (SNR). Calibration and validation of σ0 measurements from this low SNR state are performed using extended land targets with various signal strengths. Study areas include the Amazon rainforest, Congo rainforest, Argentina …

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Quantifying Transit Access In New York City: Formulating An Accessibility Index For Analyzing Spatial And Social Patterns Of Public Transportation, Maxwell S. Siegel May 2016

Quantifying Transit Access In New York City: Formulating An Accessibility Index For Analyzing Spatial And Social Patterns Of Public Transportation, Maxwell S. Siegel

Theses and Dissertations

This paper aims to analyze accessibility within New York City’s transportation system through creating unique accessibility indices. Indices are detailed and implemented using GIS, analyzing the distribution of transit need and access. Regression analyses are performed highlighting relationships between demographics and accessibility and recommendations for transit expansion are presented.

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Developing Modeling, Optimization, And Advanced Process Control Frameworks For Improving The Performance Of Transient Energy-Intensive Applications, Seyed Mostafa Safdarnejad May 2016

Developing Modeling, Optimization, And Advanced Process Control Frameworks For Improving The Performance Of Transient Energy-Intensive Applications, Seyed Mostafa Safdarnejad

Theses and Dissertations

The increasing trend of world-wide energy consumption emphasizes the importance of ongoing optimization of new and existing technologies. In this dissertation, two energy–intensive systems are simulated and optimized. Advanced estimation, optimization, and control techniques such as a moving horizon estimator and a model predictive controller are developed to enhance the profitability, product quality, and reliability of the systems. An enabling development is presented for the solution of complex dynamic optimization problems. The strategy involves an initialization approach to large–scale system models that both enhance the computational performance as well as the ability of the solver to converge to an optimal …

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Design Of Three-Dimensional Near-Zero Refractive Index Metamaterials, David Flores Iii May 2016

Design Of Three-Dimensional Near-Zero Refractive Index Metamaterials, David Flores Iii

Theses and Dissertations

Near-zero refractive index metamaterials exhibit remarkable electromagnetic properties which can and will be applied in the near future. From the known methods of achieving near-zero refractive index, this work primarily focuses on the design of 3D metamaterials whose permittivity and permeability are both close to zero while maintaining relatively low loss factor. The design of the metamaterials is based on the chiral shape “omega” and designed to weave periodically as a fishnet. Theoretical analysis, computer modeling and simulation are steps taken in the design of metamaterials. A computational tool based on the robust method for effective parameter extraction is successfully …

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Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones May 2016

Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones

Theses and Dissertations

Finite element models were created in Abaqus 6.14 to characterize the rotational stiffness of shallowly embedded column-foundation connections. Scripts were programmed to automate the model generation process and allow study of multiple independent variables, including embedment length, column size, baseplate geometry, concrete modulus, column orientation, cantilever height, and applied axial load. Three different connection types were investigated: a tied or one part model; a contact-based model; and a cohesive-zone based model. Cohesive-zone modeling was found to give the most accurate results. Agreement with previous experimental data was obtained to within 27%. Baseplate geometry was found to affect connection stiffness significantly, …

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Automatic Dependent Surveillance-Broadcast For Detect And Avoid On Small Unmanned Aircraft, Matthew Owen Duffield May 2016

Automatic Dependent Surveillance-Broadcast For Detect And Avoid On Small Unmanned Aircraft, Matthew Owen Duffield

Theses and Dissertations

Small unmanned aircraft systems (UAS) are rapidly gaining popularity. As the excitement surrounding small UAS has grown, the Federal Aviation Administration (FAA) has repeatedly stated that UAS must be capable of detecting and avoiding manned and unmanned aircraft. In developing detect-and-avoid (DAA) technology, one of the key challenges is identifying a suitable sensor. Automatic Dependent Surveillance-Broadcast (ADS-B) has gained much attention in both the research and consumer sectors as a promising solution. While ADS-B has many positive characteristics, further analysis is necessary to determine if it is suitable as a DAA sensor in environments with high-density small UAS operations. To …

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Error Propagation Dynamics Of Piv-Based Pressure Field Calculation, Zhao Pan May 2016

Error Propagation Dynamics Of Piv-Based Pressure Field Calculation, Zhao Pan

Theses and Dissertations

Particle Image Velocimetry (PIV) based pressure field calculation is becoming increasingly popular in experimental fluid dynamics due to its non-intrusive nature. Errors propagated from PIV results to pressure field calculations are unavoidable, and in most cases, non-negligible. However, the specific dynamics of this error propagation process have not been unveiled. This dissertation examines both why and how errors in the experimental data are propagated to the pressure field by direct analysis of the pressure Poisson equation. Error in the pressure calculations are bounded with the error level of the experimental data. The error bounds quantitatively explain why and how many …

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Electrical And Manufacturing Limitations For The Miniaturization Of Ion Trap Devices With Digital Excitation, Derek Joseph Andrews May 2016

Electrical And Manufacturing Limitations For The Miniaturization Of Ion Trap Devices With Digital Excitation, Derek Joseph Andrews

Theses and Dissertations

Developing portable mass spectrometry systems is an active area of research due to its broad range of useful applications, including environmental monitoring, threat detection, and space exploration. The mass analyzer is one of the key elements of the mass spectrometry system to develop for a portable system. Ion traps are a good candidate for the mass analyzer in a portable mass spectrometry system because the operating pressure scales with size. This allows for scaling down the other components of the system including the vacuum and electrical systems. Researchers at BYU are making an effort to develop miniature ion traps based …

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Thermal Conductivity Measurements Of Nanomaterials, Javier Acosta Martinez May 2016

Thermal Conductivity Measurements Of Nanomaterials, Javier Acosta Martinez

Theses and Dissertations

Thermal conductivity “k” can be defined as a material property where heat is diffused due to a temperature gradient within the material. Among the applications for thermal conductivity are: thermoelectrics, thermal interface materials, thin films, insulation, among many others. A study was made to compare the different types of studies of thermal conductivity of nanomaterials, as well as, a comparison among the different types of setups used to measure thermal conductivity. For this study a custom made thermal conductivity tester was built, this tester was validated by measuring materials with both low and high thermal conductivity, and comparing the results …

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Nonlinear Dynamics Of Electrostatically Actuated Nanotweezers, Bin Liu May 2016

Nonlinear Dynamics Of Electrostatically Actuated Nanotweezers, Bin Liu

Theses and Dissertations

Bin Liu, Nonlinear Dynamics of Electrostatically Actuated Nanotweezers. Master of Science (MS), May 2016, 77 pp, 6 tables, 59 figures, references, 25 titles. The amplitude-frequency response of electrostatic nanotube nanotweezer device system is investigated; soft alter current was setting at near half natural frequency impulse on nanotubes which are referred to as two arms, parametric and primary resonances will be shown in the results, respectively. Firstly we are using the Method of Multiple Scales (MMS) analytical model; results will be compared with Reduced Order Model (ROM). By variation and comparison of multiple parameters including van der wall molecular forces, electrostatic …

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Handcrafted Electrocorticography Electrodes For A Rodent Neural Activity, Nishat Tasnim May 2016

Handcrafted Electrocorticography Electrodes For A Rodent Neural Activity, Nishat Tasnim

Theses and Dissertations

Electrocorticography (ECoG) is a minimally invasive neural recording method that has been extensively used for neuroscience applications. Although many neural recording methods exist, ECoG provides a combination of stability, high spatial and temporal resolution with chronic and mobile capabilities. This paper presents an animal study using a low cost and simple handcrafted ECoG electrode that is made of commercially accessible materials. The study is performed on a Lewis rat implanted with a handcrafted 32-channel non-penetrative ECoG electrode covering an area of 3 x 3 mm 2 on the cortical surface. The ECoG electrodes were placed on the motor and somatosensory …

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Impact Of Virtualization On Cloud Network Security, Koushicaa Sundar May 2016

Impact Of Virtualization On Cloud Network Security, Koushicaa Sundar

Theses and Dissertations

In this thesis, experimental evaluation of the effect of virtualization on the availability of servers has been performed under Distributed Denial of Service (DDoS) attacks for popular server Operating Systems such as Windows Server 2008 R2, Windows Server 2012 R2 virtualized using Hyper-V. A comparative evaluation of the performance of the servers before and after virtualization under DDoS attacks indicates that after virtualization there is a considerable increase in the vulnerability to attacks and a decline in the performance of the virtualized server compared to when the server is not virtualized.

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Graphene-Based Nanomaterials For Hydrogen Generation And Storage, Lin Wei May 2016

Graphene-Based Nanomaterials For Hydrogen Generation And Storage, Lin Wei

Theses and Dissertations

Hydrogen energy is promising candidate to replace fossil fuel. However, the usage of hydrogen energy was greatly limited due to its generation and storage. In this thesis report, the author synthesized novel metal/carbon nanomaterials used for the hydrogen storage and hydrogen evolution reaction. These materials were characterization by XRD, Raman, XPS, SEM, EDX, etc. And the surface area and the hydrogen storage properties were tested by ASAP 2020, using the BET measurement and hydrogen isotherm curves to discuss the gas adsorption properties. As for hydrogen evolution reaction, the materials were made into electrodes and tested with LSV, CV to shows …

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