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Numerical Simulation Of Shock Wave Propagation In Ducts With Grooves, Seyed Mehdi Mortazawy 2018 Embry-Riddle Aeronautical University

Numerical Simulation Of Shock Wave Propagation In Ducts With Grooves, Seyed Mehdi Mortazawy

Dissertations and Theses

The pressure attenuation of moving shocks when they propagate in ducts, is of great importance in a wide variety of applications, such as health, safety, and transportation. The objective of this research is to simulate the propagation of shock waves in ducts with roughness. The roughness is added in the form of grooves as in an existing experiment. Different shapes are considered in order to better understand the physics behind the evolution of the complex shock patterns resulting from diffraction, reflection and refraction of the primary moving shock. The contribution of grooves and duct shape on these phenomena and pressure ...


A Novel Magnetorheological Fluid Damper For A Small Spacecraft With Flexible Appendages, Robert Waelchili 2018 Embry-Riddle Aeronautical University

A Novel Magnetorheological Fluid Damper For A Small Spacecraft With Flexible Appendages, Robert Waelchili

Dissertations and Theses

Small satellites have become increasingly popular over the past thirty years, particularly since the adoption of the common CubeSat architecture early this century. Because of their restricted volume and electrical budgets however, there are practical limits to the missions that small satellites may adopt. One potential near-term solution to the problem of limited electrical power may be the adoption of larger, flexible solar arrays. However, spacecraft with flexible appendages have historically presented attitude control challenges relating to platform stability given the dynamic response of the flexible components to applied torques. These challenges may be particularly disruptive to a small spacecraft ...


Vision-Aided Navigation Using Tracked Lankmarks, Nicodemus Myhre 2018 Embry-Riddle Aeronautical University

Vision-Aided Navigation Using Tracked Lankmarks, Nicodemus Myhre

Dissertations and Theses

This thesis presents vision-based state estimation algorithms for autonomous vehicles to navigate within GPS-denied environments. To accomplish this objective, an approach is developed that utilizes a priori information about the environment. In particular, the algorithm leverages recognizable ‘landmarks’ in the environment, the positions of which are known in advance, to stabilize the state estimate. Measurements of the position of one or more landmarks in the image plane of a monocular camera are then filtered using an extended Kalman filter (EKF) with data from a traditional inertial measurement unit (IMU) consisting of accelerometers and rate gyros to produce the state estimate ...


Design, Fabrication, And Characterization Of Novel Optoelectronic Devices For Near-Infrared Detection, Ahmad Nusir 2018 University of Arkansas, Fayetteville

Design, Fabrication, And Characterization Of Novel Optoelectronic Devices For Near-Infrared Detection, Ahmad Nusir

Theses and Dissertations

Investigating semiconductor materials and devices at the nanoscale has become crucial in order to maintain the exponential development in today’s technology. There is a critical need for making devices lower in power consumption and smaller in size. Nanoscale semiconductor materials provide a powerful platform for optoelectronic device engineers. They own interesting properties which include enhanced photoconductivity and size-tunable interband transitions.

In this research, different types of nanostructures were investigated for optoelectronic devices: nanocrystals, nanowires, and thin-films. First, lead selenide nanocrystals with narrow bandgap were synthesized, size-tailored, and functionalized with molecular ligands for the application of uncooled near-infrared photodetectors. The ...


Methods For The Aerostructural Design And Optimization Of Wings With Arbitrary Planform And Payload Distribution, Jeffrey D. Taylor 2018 Utah State University

Methods For The Aerostructural Design And Optimization Of Wings With Arbitrary Planform And Payload Distribution, Jeffrey D. Taylor

All Graduate Theses and Dissertations

The design of an aircraft wing often involves the use of mathematical methods for simultaneous aerodynamic and structural design. The goal of many of these methods is to minimize the drag on the wing. A variety of computer models exist for this purpose, but some require the use of expensive time and computational resources to give meaningful results. As an alternative, some mathematical methods have been developed that give reason ably accurate results without the need for a computer. However, most of these methods can only be used for wings with specific shapes and payload distributions. In this thesis, a ...


Simulation And Optimization Models To Evaluate Performance Of Aquifer Storage And Recovery Wells In Fresh Water Aquifers, Ali Forghani 2018 Utah State University

Simulation And Optimization Models To Evaluate Performance Of Aquifer Storage And Recovery Wells In Fresh Water Aquifers, Ali Forghani

All Graduate Theses and Dissertations

Aquifer storage and recovery (ASR) involves artificially recharging an aquifer through well(s) using surplus water for later recovery in high-demand months. The operators of the studied ASR system developed the system as a means of receiving additional water rights to supplement their pre-existing water rights for extraction in dry months. However, the region’s water regulators define the performance of this ASR system as the amount of the injected water that is recoverable from the same wells during extraction periods. The study proposes recovery effectiveness (REN) as the performance index of this ASR system. REN equals the injectate proportion ...


A Propeller Model Based On A Modern Numerical Lifting-Line Algorithm With An Iterativesemi-Free Wake Solver, Zachary S. Montgomery 2018 Utah State University

A Propeller Model Based On A Modern Numerical Lifting-Line Algorithm With An Iterativesemi-Free Wake Solver, Zachary S. Montgomery

All Graduate Theses and Dissertations

A fundamental aerodynamic analysis technique for a single straight fixed wing has been expounded upon and turned into a modern technique that can analyze multiple wings of more realistic shapes common on aircraft. This modern technique is extended further to apply towards propellers. A method to overcome propeller analysis problems at low airspeeds is presented. This method is compared to more traditional propeller analysis techniques.


Distribution Of Particle Image Velocimetry (Piv) Errors In A Planar Jet, Jaron A. Howell 2018 Utah State University

Distribution Of Particle Image Velocimetry (Piv) Errors In A Planar Jet, Jaron A. Howell

All Graduate Theses and Dissertations

Particle Image Velocimetry (PIV) is an optical fluid measurement technique used to obtain velocity measurements. Two PIV systems were used to capture data simultaneously and measurement error for the MS PIV system is calculated. An investigation of error distribution is performed to determine when uncertainty estimations fail for the CS PIV-UQ method. Investigation of when results from multi pass PIV processing are achieve were performed so that reliable uncertainty estimations are produced with the CS method. An investigation was also performed which determined that error distributions in PIV systems are correlated with flow shear and particle seeding density. Correlation of ...


Allocating Interventions Based On Counterfactual Predictions: A Case Study On Homelessness Services, Amanda R. Kube 2018 Washington University in St. Louis

Allocating Interventions Based On Counterfactual Predictions: A Case Study On Homelessness Services, Amanda R. Kube

Engineering and Applied Science Theses & Dissertations

Modern statistical and machine learning methods are increasingly capable of modeling individual or personalized treatment effects by predicting counterfactual outcomes. These counterfactual predictions could be used to allocate different interventions across populations based on individual characteristics. In many domains, like social services, the availability of possible interventions can be severely resource limited. This thesis considers possible improvements to the allocation of such services in the context of homelessness service provision in a major metropolitan area. Using data from the homeless system, I show potential for substantial predicted benefits in terms of reducing the number of families who experience repeat episodes ...


The Response Of Fuzzy Electronics To Ionizing Radiation, Simar Singh 2018 University of Tennessee at Chattanooga

The Response Of Fuzzy Electronics To Ionizing Radiation, Simar Singh

Honors Theses

Small satellites such as CubeSats operate under environmental constraints that are outside of typical commercial specifications. Such constraints include the ability to operate over an extended temperature range and during exposure to ionizing radiation. Nevertheless, commercial technologies are being implemented in CubeSat spacecraft because of the low-cost, low-power, and space savings requirements often achievable with advanced microelectronics [1]. Due to flexibility and the ability to handle uncertainty, fuzzy logic is viable for satellite control while meeting the strict design requirements of a CubeSat. This work evaluates the response of fuzzy control logic to ionizing radiation and compares the response to ...


Improving Alternative Fuel Efficiency With Water Injection, Connor Strawn 2018 University of Tennessee at Chattanooga

Improving Alternative Fuel Efficiency With Water Injection, Connor Strawn

Honors Theses

Alternative fuel internal combustion engines (ICEs) have been increasing in popularity as the harmful effects of pollution and the need for a sustainable energy source are becoming more apparent. Two alternative fuels, E85 and hydrogen gas, are considered in this study. These fuels are renewable and have less emissions than traditional fuels, but there are many inherent disadvantages to their use. Water injection could alleviate some of the issues that plague these fuels. To test this, a Briggs and Stratton Baja engine was used, with and without water injection. Gasoline with water injection showed better performance than without: the power ...


Advancing The Implementation Of Hydrologic Models As Web-Based Applications, Prasanna Dahal 2018 Utah State University

Advancing The Implementation Of Hydrologic Models As Web-Based Applications, Prasanna Dahal

All Graduate Theses and Dissertations

Deeper understanding of relationships between flow in river sand various hydrologic elements such as rainfall, land use, and soil type is imperative to solve water related problems like droughts and floods. Advanced computer models are becoming essential in helping us understand such relationships. However, preparing such models requires huge investment of time and resources, much of which are concentrated on acquisition and curation of data. This work introduces agree and open source web Application (web App) that provides researchers with simplified access to hydrological data and modeling functionality. The web App helps in the creation of both hydrologic models, and ...


Mitochondrial Mrna Translation Is Required For Maintenance Of Oxidative Capacity, David Lee 2018 University of Arkansas, Fayetteville

Mitochondrial Mrna Translation Is Required For Maintenance Of Oxidative Capacity, David Lee

Theses and Dissertations

Oxidative metabolism is required to produce adequate energy to sustain human life. A primary example of deteriorating oxidative capacity is seen in the cardiac musculature during chronic heart failure. This suggests that by improving oxidative potential, chronic heart disease could be mitigated and one approach to accomplish this may be through targeting the mt-mRNA translation system. Purpose: This investigation’s purpose was to characterize disruptions in mt-mRNA translation machinery in multiple forms of cardiomyopathy and to determine if mitochondrial mRNA translation initiation factor (mtIF2) is necessary to maintain oxidative capacity in cardiomyocytes. Methods Using a combination of animal and cell ...


Career: Nanoscale Thermal Transport In Hydrogen-Bonded Materials, Ling Liu 2018 Utah State University

Career: Nanoscale Thermal Transport In Hydrogen-Bonded Materials, Ling Liu

Funded Research Records

No abstract provided.


Developing Kenya’S Educational Capacity In Nuclear Security Through Nuclear Forensics Research, Hudson Kalambuka Angeyo 2018 Department of Physics, University of Nairobi, Kenya

Developing Kenya’S Educational Capacity In Nuclear Security Through Nuclear Forensics Research, Hudson Kalambuka Angeyo

International Journal of Nuclear Security

Nuclear energy’s distinctive characteristics give rise to special educational requirements. These requirements are necessary to not only address the danger of nuclear proliferation, but also to build capacity for a secure nuclear fuel circle. In this paper, I assess the status of educational capacity in nuclear security both in response to, and in support of, Kenya’s nuclear power program. I highlight the nuclear security educational infrastructure’s key features in the context of nuclear power, noting the low capacity at Kenyan universities. I identify the steps required to ensure that the country’s dynamic nuclear regulatory infrastructural framework ...


Additive Manufacturing Of High Solids Loading Hybrid Rocket Fuel Grains, Stephen P. Johnson 2018 Olivet Nazarene University

Additive Manufacturing Of High Solids Loading Hybrid Rocket Fuel Grains, Stephen P. Johnson

Scholar Week 2016 - present

Hybrid rocket motors offer many of the benefits of both liquid and solid rocket systems. Like liquid engines, hybrid rocket motors are able to be throttled, can be stopped and restarted, and are safer than solid rocket motors since the fuel and oxidizer are in different physical states. Hybrid rocket motors are similar to solid motors in that they are relatively simple and have a high density-specific impulse. One of the major drawbacks of hybrid rocket motors is a slower burning rate than solid rocket motors. Complex port geometries provide greater burning surface area to compensate for lower burning rates ...


Vocal Processing With Spectral Analysis, Brad Fitzgerald 2018 Olivet Nazarene University

Vocal Processing With Spectral Analysis, Brad Fitzgerald

Scholar Week 2016 - present

A method of vocal signal processing was examined to determine if principal component analysis of spectral data may be used to characterize differences between speakers and if these differences may be used to separate mixtures of vocal signals. Processing was done on a set of voice recordings from 30 different speakers in order to create a projection matrix which could be used by an algorithm to identify the source of an unknown recording from one of the 30 speakers. Two different identification algorithms were tested, both of which were generally unable to correctly identify the source of a single vocal ...


Design Optimization For A Cnc Machine, Alin Resiga 2018 Portland State University

Design Optimization For A Cnc Machine, Alin Resiga

Dissertations and Theses

Minimizing cost and optimization of nonlinear problems are important for industries in order to be competitive. The need of optimization strategies provides significant benefits for companies when providing quotes out for products. Accurate and easily attained estimates allow for less waste, tighter tolerances, and better productivity. The Nelder-Mead Simplex method with exterior penalty functions was employed to solve optimum machining parameters. Two case studies were presented for optimizing cost and time for a multiple tools scenario. In this study, the optimum machining parameters for milling operations were investigated. Cutting speed and feed rate are considered as the most impactful design ...


Library Awesome Sauce Undergraduate Research, Jeremy Evert, Phillip Joe Fitzsimmons, Hector Lucas 2018 Southwestern Oklahoma State University

Library Awesome Sauce Undergraduate Research, Jeremy Evert, Phillip Joe Fitzsimmons, Hector Lucas

Faculty Articles & Research

Library Awesome Sauce Undergraduate Research was a presentation at the 2018 CADRE Conference in Stillwater, OK. The presenters discussed their collaboration on a video project to film interviews of students giving progress reports about their software engineering projects. The videos were posted on the institutional repository.

The speakers discussed Student-Led research and the role that academic libraries play in facilitating student and faculty research and publishing for all disciplines on campus.


Pborrego_Umasslowell_Chemistrydepartment_April2018.Pdf, Paulina Borrego 2018 University of Massachusetts - Amherst

Pborrego_Umasslowell_Chemistrydepartment_April2018.Pdf, Paulina Borrego

Paulina Borrego

Patent presentation to University of Massachusetts Lowell graduate students and faculty. Presented on Wednesday April 18, 2018.


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