Engineering Commons^™

Developing Improved Techniques For Gpr Guided Wave Data Analysis, Yunyi Guan

Masters Theses

"This study was conducted to investigate how limiting the allowable velocity range when analyzing guided wave data will affect the results of dielectric permittivity and thickness estimation. We conducted four sets of Experiments: an underlying layer of saturated organic loam is covered by incremental layers of the dry organic loam; a base layer of dry organic loam covered by the saturated organic loam; a saturated basal layer of silt with overlying dry silt layers, and a base layer of dry silt overlain by saturated silt layers to conduct a comparative study and perform three surveys for each of these three …

Field Implementation Of Cement-Based Composite Strengthening Technologies, Michael Andrew Janke

Masters Theses

"With infrastructure continuing to age, technologies are being developed to strengthen structures as a more sustainable option than replacement. The use of fiber-reinforced cementitious matrix (FRCM) strengthening systems is a promising new technology for adding flexural and shear capacity to existing reinforced concrete members. While cement based systems with carbon, PBO, and steel have all been implemented in a lab setting, there is not research data available for installation in the field. FRCM composites have advantages over more widely used fiber reinforced polymer (FRP) composites such as heat resistance and compatibility with concrete substrate. FRP systems have previously been field …

An Investigation Into The Effects Of Ion Tracks On Α-Quartz, Bryant Alan Kanies

Masters Theses

"The passage of a swift heavy ion through a material can cause columnar, amorphous nano-structures known as ion tracks. Swift heavy ions are present in a number of applications ranging from nuclear reactors to nuclear waste storage and onboard spacecraft. The study of ion tracks has been ongoing since the late 1950s and has led to several technological advancements. In fact, ion beams have been used to enhance material properties and aid in the production of electrical components. Ion beams, and their resultant ion tracks, can therefore be seen as a method to purposefully alter material properties such as thermal …

Characterization And Tailoring Of Powder Used In Additive Manufacturing And Plasma Spheroidization, Caitlin S. Kriewall

Masters Theses

"There are many processes that use metal powder as the starting material for the production of parts. With the growth of these manufacturing techniques, more critical part applications are being considered. In order to fully understand the process and create consistent parts, powder properties need to be well understood. Selective laser melting (SLM) is a powder bed-based additive manufacturing process. During processing, heat-affected powders are generated and can deposit within the build area. The current work investigated the characterization of heat-affected 304L stainless steel powder using techniques such as scanning electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy to detect …

Smart Augmented Reality Instructional System For Mechanical Assembly, Ze-Hao Lai

Masters Theses

"Quality and efficiency are pivotal indicators of a manufacturing company. Many companies are suffering from shortage of experienced workers across the production line to perform complex assembly tasks such as assembly of an aircraft engine. This could lead to a significant financial loss. In order to further reduce time and error in an assembly, a smart system consisting of multi-modal Augmented Reality (AR) instructions with the support of a deep learning network for tool detection is introduced. The multi-modal smart AR is designed to provide on-site information including various visual renderings with a fine-tuned Region-based Convolutional Neural Network, which is …

Analysis And Mitigation Of Parallel-Plate Noise For High-Isolation Applications, Zachary Joel Legenzoff

Masters Theses

"Achieving highs levels of isolation between different functionalities in a PCB can be challenging. One of the major issues is that vertically adjacent planes or area fills in a PCB can form a parallel-plate waveguide with no cutoff frequency and serve as an efficient coupling mechanism between interconnects. Due to the finite size of the conductors, reflections off the edges of these parallel-plate cavities can result in the formation of standing-wave patterns with very high field strengths, resulting in high coupling at certain frequencies. This noise coupling mechanism can be suppressed by connecting the parallel plates together with an adequate …

Imaging The Subsurface In Eastern Part Of Lake Chesterfield Using A Combination Of Geophysical Tools, Jiawei Li

Masters Theses

"The Lake Chesterfield North Dam in Wildwood city, Missouri has been leaking, more or less continuously since the dam was constructed in 1986 despite mitigation efforts in 1988, 1994, 1995, 2004, and 2005. Neither the grouting efforts in 1988, 1994, 1995, 2004 or 2005, nor the placement and rehabilitation of an impervious clay liner in 2005 has solved the problem. Indeed, in June of 2017, the water level in Lake Chesterfield dropped at an alarmingly rapid rate.

Prior to authorizing additional mitigation work, the Lake Chesterfield Home Owners Association (LCHOA) decided to acquire geophysical data across the dry lake bed. …

Microstructural Development And Its Effect On Aqueous Corrosion Of A Borosilicate Glass Ceramic For Waste Vitrification, Nicholas Stephen Roberts

Masters Theses

"Waste loadings of reprocessed spent nuclear fuel vitrified into borosilicate glass can be increased by precipitating environmentally stable phases concentrated with waste components in a chemically stable glass matrix. The principal objective of this thesis was to characterize the development of crystalline powellite (CaMoO₄ and related phases) and oxyapatite (Ca₂LN₈Si₆O₂₆) in borosilicate glass-ceramics and to determine how the formation of those phases affected its chemical durability.

Borosilicate glasses provided by PNNL were re-melted and quenched at rates from over 300⁰C/s to ~0.05⁰C/s. Isothermal heat treatment experiments were conducted by quenching melts …

Modulated Photothermal Radiometry: Detector Sensitivity Study And Experimental Setup, Jessica Nicole Seals

Masters Theses

"This thesis outlines the development of a system used for determining the surface thermal diffusivity of both non-irradiated and irradiated materials. The motivation for this work is to establish a modulated photothermal radiometry (PTR) system on the campus of Missouri University of Science and Technology. One of the main efforts described in this thesis is the design and construction of the physical apparatus. Along the way, it was necessary to perform a detailed sensitivity analysis of the system to determine whether the expected signal emitted from the sample falls within the bounds of detectivity for the HgCdTe (MCT) detector used …

Investigation Of Proppant Static Settling Velocity In Hydraulic Fractures Using Viscoelastic Linear Gel, Vismay Manishbhai Shah

Masters Theses

"Few studies have quantified proppant transport in static conditions using actual proppant and validated previously established correlation. The objective of this study is to investigate the rheological properties of the linear gel, and determine the effect of size, shape and specific gravity of the proppant, fracture walls and rheological properties of the fluid on the proppant settling velocity in static condition and validate the previously established correlation.

Shear viscosity and dynamic frequency sweep tests were performed to investigate the viscous and viscoelastic behaviour of the HPG linear gel with five different concentrations. Proppant settling experiments were conducted with different proppant …

Hydraulic Fracture Design Optimization For Nubian Sandstone Formation In Libya, Housameddin Mohamed Sherif

Masters Theses

There is growing interest in developing unconventional oil and gas reserves in Libya, such as the tight portions of the Nubian sandstone.

Well-X7 is a development well drilled to a TD of 13,005' penetrating the Upper Nubain Sandstone (UNSS) at 12,122'-12,207' and the Lower Nubain Sandstone (LNSS) at 12,524'-12,880' KB. Based on open hole logs, the UNSS has 71 ft of net pay and the LNSS was found to have 295 ft of net pay. Openhole logs also showed low permeabilities of 2.5 and 3 md for the UNSS and LNSS, respectively. The well was initially perforated in both zones …

Practical Dwell Times For Switched System Stability With Smart Grid Application, William Roy St. Pierre

Masters Theses

"Switched systems are encountered throughout many engineering disciplines, but confirming their stability is a challenging task. Even if each subsystem is asymptotically stable, certain switching sequences may exist that drive the overall system states into unacceptable regions. This thesis contains a process that grants stability under switching to switched systems with multiple operating points. The method linearizes a switched system about its distinct operating points, and employs multiple Lyapunov functions to produce modal dwell times that yield stability. This approach prioritizes practicality and is designed to be useful for large systems with many states and subsystems due to its ease …

Development Of A Cfd Model Of The Catalytic Combustion Of A Microtube Multi-Mode Propulsion System, Andrew Paul Taylor

Masters Theses

"This thesis presents the process and results of the development of a computational fluid dynamics (CFD) model in ANSYS Fluent 18.1 on the catalytic decomposition of a novel liquid monopropellant in a microtube in order to gain deeper insights than what is available through the experimental data. The CFD model was created using the Euler- Euler Multiphase model in conjunction with the Heterogeneous Reaction submodel. Such a choice of modeling setting was backed up by theory and benchmark computations on multiphase and compressible flow, shown in Section 3 and Appendix A. It was found that the previously determined one-step reaction …

3d Dubins Curves For Multi-Vehicle Path Planning, Yiheng Wang

Masters Theses

"This thesis proposes a unified algorithm for target assignment and path planning in 3D space for multiple Autonomous Underwater Vehicles (AUVs) to visit multiple targets. The multi-target assignment and path planning problem is modeled as a multiple Traveling Salesmen Problem (mTSP) and is usually solved by two separate algorithms: the multiple task assignment problem is first solved by the Genetic Algorithm (GA) using Euclidean distances between the targets; then the 3D path planning problem is solved for each assignment by selecting Dubins curves or other continuity curves. In contrast, this paper embeds the 3D Dubins curve selection into the target …

Tvs Transient Behavior Modeling Method, And System-Level Effective Esd Design For Usb3.X Interface, Pengyu Wei

Masters Theses

"This research proposal presents a methodology whereby a protection device can be modeled in SPICE compatible platforms with respect to the transient behaviors during Electrostatic Discharge (ESD) events. This methodology uses an exclusively "black-box" approach to characterize the parameters of the protection device, thereby allowing it to be implemented without intimate knowledge of the DUT. Results of this methodology can be used to predict the transient response (conductivity modulation and snapback delay) of the ESD protection devices, and thereby predicts how much current could flow into the device (typically a digital IO pin) under protection. The transient behavior modeling methodology …

Conical Folds -- An Artifact Of Using Simple Geometric Shapes To Describe A Complex Geologic Structure, Avery Joseph Welker

Masters Theses

"Accurate representation of the 3D shapes of natural folds is essential to characterization of the dynamic models for fold formation. Geometrical analysis of folds commonly relies upon analyzing patterns defined by the variation in the orientation of poles to planar surfaces deformed by a shortening event when plotted using graphical calculators (e.g., stereogram, polar tangent diagrams) to interpret the shape of folds. Stereograms for which orientation data define small circles are classified as non-cylindrical regular folds and are interpreted as "conical folds," where the shape of the fold is represented by a cone that terminates at a point. Utilizing similar …

Spatial Resolution Study For Magnetic Near-Field Probe, Xin Yan

Masters Theses

"Spatial resolution is an important factor of near-field probe, which represents the ability to distinguish two close radiation sources. Traditional definition of spatial resolution is the distance between peak point and -6dB point when measuring microstrip line. The definition has disadvantage and limitation. In this topic, spatial resolution for magnetic near-field probe is studied, and three dimensions of spatial resolution are put forward. An optimized measurement setup is presented to reflect spatial resolution of probe properly. Then, an example is given to show how spatial resolution affects field distribution in near-field measurement"--Abstract, page iv.

System Level Power Integrity Transient Analysis Using A Physics-Based Approach, Jun Xu

Masters Theses

"With decreasing supply voltage level and massive demanding current on system chipset, power integrity design becomes more and more critical for system stability. The ultimate goal of well-designed power delivery network (PDN) is to deliver desired voltage level from the source to destination, in other words, to minimize voltage noise delivered to digital devices. The thesis is composed of three parts. The first part focuses on-die level power models including simplified chip power model (CPM) for system level analysis and the worst scenario current profile. The second part of this work introduces the physics-based equivalent circuit model to simplify the …

Coaxial Cable Ring Resonator Based On Pair Sided Coaxial Cable Bragg Grating Coupler For Sensing Appllication, Xiaotong Tang

Masters Theses

“Coaxial cable based devices, such as coaxial cable Bragg grating (CCBG), coiled coaxial cable resonator have been demonstrated for sensing applications to address the challenges faced by fiber optic sensors (e.g., large strain survivability, installation). Inspired by the fiber ring resonator (FRR), coaxial cable based ring resonator (CCRR) is reported in this thesis. The device mainly formed by a homemade coaxial cable Bragg grating (CCBG) pair based side coupler. Comparing to the commercial coupler, CCBG-SC improves the flexibility of the device for sensing applications. The coupling frequency of the CCBG-based coupler can be modified by changing the grating length and …

Distributed Fiber Optic Sensors For Monitoring Spatially Continuous Strain And Quasi-Distributed Refractive Index Using Optical Frequency Domain Reflectometry, Sasi Jothibasu

Masters Theses

"This thesis is comprised of two papers and they describe distributed fiber optic sensing using an optical frequency domain reflectometry (OFDR) instrumentation system.

The first paper presents about distributed fiber optic sensor embedded within the layers of a composite laminates to monitor the continuous profile of strain using the optical frequency domain reflectometry (OFDR) system. The OFDR system was used to analyze the Rayleigh backscattered signal. The shift in the Rayleigh backscattered spectrum (RBS) was observed to be linearly related to the change in strain of the composite material. The continuous strain sensing using OFDR was demonstrated by an INSTRON …

Efficient Implementation Of Ieee 802.11i Wi-Fi Security (Wpa2-Psk) Standard Using Fpga, Atal Bajracharya

Masters Theses

The rationale behind the thesis was to design efficient implementations of cryptography algorithms used for Wi-Fi Security as per IEEE 802.11i Wi-Fi Security (WPA2-PSK) standard. The focus was on software implementation of Password-Based Key Derivation Function 2 (PBKDF2) using Keyed-Hash Message Authentication Code (HMAC)-SHA1, which is used for authentication, and, hardware implementation of AES-256 cipher, which is used for data confidentiality.

In this thesis, PBKDF2 based on HMAC-SHA1 was implemented on software using C programming language, and, AES-256 was implemented on hardware using Verilog HDL. The overall implementation was designed and tested on Nexys4 FPGA board. The performance of the …

Model Predictive Power Management Of A Hybrid Electric Propulsion System For Aircraft, Tyler J. Wall

Masters Theses

This work presents the switched optimal power flow control for an aircraft with a hybrid electric propulsion system. The propulsion system is a switched system that operates in either of two modes: (i) battery discharging and electric motor propelling and (ii) battery charging and electric motor generating. The aircraft model and components that form the hybrid propulsion system are modeled as either an algebraic power source/sink or as a dynamic model with appropriate power and state interconnections. With the system model defined, a model predictive control power management strategy is set fourth which minimizes a performance index that includes altitude …

Visualizing The Constructability Of A Steel Structure Using Building Information Modeling And Game Simulation, Mohammed Al Dafaay

Masters Theses

This research aims to visualize a steel structural design to: (1) analyze its constructability, and (2) support collaboration between project participants at the planning stage. The visualization uses Building Information Modeling (BIM) and game engine simulation to develop a realistic interactive simulation for constructability analysis. A case study experiment was conducted on visualizing the erection process of a steel structure to facilitate the understanding of needed construction operation. The simulation incorporated construction domain knowledge through various entity components and predefined interaction rules. Results showed that through such a visualization method, field operation can be observed in real-time at the planning …

Finite Element Analysis Of Tibiofemoral Contact Mechanics, Erika Fojtik

Masters Theses

The effects of lateral meniscus posterior root avulsions (LMPRA) have been studied in combination with meniscofemoral ligament (MFL) deficiencies. The purpose of this study is to validate a set of biomechanical finite element analyses against previously reported experimental results to predict the contact area and peak contact pressure in the lateral tibiofemoral compartment of the knee during lateral meniscal root avulsions in combination with MFL deficiencies. Patient specific MRI data was used to develop finite element models for three distinct testing conditions: 1) intact, 2) lateral meniscus posterior root avulsion, and 3) lateral meniscus posterior root avulsion with deficient meniscofemoral …

Enhancing Intersection Safety For The Blind And Visually Impaired (Bvi) Pedestrian Using Device-To-Infrastructure Communication, Mohammad Sayyah Al-Akash

Masters Theses

Visually impaired pedestrians have limited mobility options, where they rely heavily on walking and transit for their transportation needs. One of the major issues facing these pedestrians is intersection crossing. Accessible Pedestrian Signals (APS), as a means of helping their intersection crossings, were introduced in the United States as early as 1920 but were not included in the Manual on Uniform Traffic Control Device (MUTCD) until 2000. The most recent type of APS is the beaconing APS which has shown improvements in road crossing abilities of blind pedestrians though it has many downsides to it. This study developed a cane …

Experimental Study Of Global Luminescent Oil-Film (Glof) Skin-Friction Meter On Delta Wings, Patrick Nicholas Wewengkang

Masters Theses

This thesis describes how the Global Luminescent Oil-Film (GLOF) Skin-Friction Meter can be applied experimentally to extract skin-friction from a set of images. In this study, the effect of oil viscosity, experimental sample size, and step size were considered to see how they would affect the extracted skin-friction using the GLOF method. These results were then compared to published literature on skin-friction diagnostics of delta wings, based on observations of critical characteristics such as reattachment and separation lines. Delta wings of 50°, 55°, 60°, 65°, and 70° sweep angles were built and placed in the Small Wind Tunnel (SWT) at …

Papermaking Factors Affecting Lateral Web Position During Commercial Heat Set Web Offset Printing, George W. Shields

Masters Theses

The interaction of water with paper plays a role in web handling characteristics during commercial heat set web offset printing. Water absorption leads to lower web tension for a given strain.

This research investigates paper properties and their role in preventing lateral web movement from cross machine air flows in the drying section during normal printing operations. Tensile properties of sheets are measured at various moisture contents and then used to determine the equilibrium stress-strain relationship for papers at moisture contents typical of heat set web offset printing. Permeability, fiber orientation and tensile stiffness are evaluated against lateral web movement …

A Cfd Study Of A Multi-Element Front Wing For A Formula One Racing Car, Shardul C. Kachare

Masters Theses

Presently, one of the key factors in determining a success of an open wheel racecar such as Formula One or Indy car, is its aerodynamic efficiency. A modern racecar front wing can generate about 30% of the total downforce. The present study focuses on investigating the aerodynamic characteristics of such highly efficient multi-element front wing for a Formula One racecar by conducting a three-dimensional computational analysis using Reynolds Averaged Navier-Strokes model. A three-dimensional computational study is performed investigating predictive capability of the structured trimmer and unstructured polyhedral meshing model to generate a three-dimensional volume mesh for a multi-element front wing. …

Effect Of Arm Motion On Standing Lateral Jump Performance, Arif Ahmed Sohel

Masters Theses

Previous jumping studies have examined the role of arm swing in vertical and horizontal long jump performance, but none have been found which studied the role of arm swing in standing lateral jumps. The purpose of this study was to investigate the effect of arm motion on standing lateral jump performance and to examine the biomechanical mechanisms that may explain differences in jump distance.

A series of lateral jump experiments was performed for two jump cases (free and restricted arms) in which six participants jumped laterally for maximum distance from two in-ground force platforms. A motion capture system collected 3D …

Query Expansion Techniques For Enterprise Search, Eric M. Domke

Masters Theses

Although web search remains an active research area, interest in enterprise search has waned. This is despite the fact that the market for enterprise search applications is expected to triple within the next six years, and that knowledge workers spend an average of 1.6 to 2.5 hours each day searching for information. To improve search relevancy, and hence reduce this time, an enterprise- focused application must be able to handle the unique queries and constraints of the enterprise environment. The goal of this thesis research was to develop, implement, and study query expansion techniques that are most effective at improving …