Engineering Commons^™

Quantifying On-Orbit Performance Of Cubesat Micropropulsion Systems By Observing Orbital Element Variations, Bradyn William Morton

Masters Theses

"The Advanced Propulsion Experiment mission in development by the Missouri University of Science and Technology's satellite research team (M-SAT) is a technology demonstration mission of a multi-mode propulsion system. The true test of any satellite propulsion system is the on-orbit performance. The purpose of this research is to develop methods for quantifying the on-orbit performance of the multi-mode propulsion system. This performance can be determined by observing the small variations in the orbital element parameters and using a differential corrector with the Gauss Variation of Parameter equations. Furthermore, this research could be used to determine and quantify a propulsion system's …

Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin

Masters Theses

The purpose of this study was to investigate durable solar cell cover glass joins produced by diffusion bonding with deep eutectic solvents (DES) and to develop a novel process of joining optically transparent materials at low temperatures. A joined PV cell-glass specimen was characterized using Raman, μ-FTIR, SEM-EDS, and thin-film XRD. DESs were created with malonic acid (MAL) and choline chloride (ChCl) of varying composition factors (CF; CF=MAL/ChCl). Joining borosilicate glass coupons was attempted using DESs with CF = 0.65 and 1 at temperatures between 100-150 °C for 20 hours. Joining the glass coupons failed at all temperatures and oxygen …

Customized Multi-Group Cross Section Generation With Njoy For Discrete Ordinates Computed Tomography And Radiography Simulation, Steven Michael Wagstaff

Masters Theses

"The purpose of this work was to explore the creation of photoatomic multi-group cross section libraries to be used with a software package DOCTORS (Discrete Ordinates Computed TOmography and Radiography Simulator). This software solves the linear Boltzmann equation using the discrete ordinates method [1]. To create these libraries, NJOY2016 was used, creating both fine and broad energy multi-group cross section files. The cross section's accuracy was tested against an equivalent Monte Carlo simulation using MCNP6.

Two simulation geometries were used. The first, a cylindrical water phantom with a single source projection placed in front, simulating an X-ray radiography. The second …

Effect Of Microstructural Features On Steel Machinability, Mark C. Emmendorfer

Masters Theses

Non-metallic inclusions can have a tremendous impact on the machinability of steel. Some oxide inclusions such as alumina, spinel, and other refractory abrasive oxide inclusions can have a detrimental effect on machinability. Modification of oxide inclusions by calcium treatment can promote the formation of low melting point oxides such as anorthite and gehlenite inclusions that can assist in chip formation and form a lubricating layer on the rake surface of the machine tool. MnS is known to be beneficial to improving the machinability of steel. They assist in chip formation by being heavily deformed in the primary shear zone. Sulfide …

The Development Of A New Formulation Of Fly Ash Class C Based Geopolymer And Assessing Its Performance In Presence Of Drilling Fluid Contamination, Mohamed Saad Ahdaya

Masters Theses

"Cementing is one of the most critical steps in the drilling and completion of oil wells. Traditionally, Portland cement is used for oil cementing operations; however, geopolymer materials have recently attracted much attention because they are more cost-effective and have less environmental impacts.

An intensive laboratory work was conducted to obtain a new formulation of fly ash class C based geopolymer cement to be used as a potential alternative cementing material to Portland cement in oil and gas cementing. Twenty-four variations of fly ash class C based geopolymers were prepared, and by comparing several of their properties using API standard …

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 …

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 …

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 …

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 …

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.

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 …

Enhancing Frp-To-Concrete Bond Behavior By Epoxy Ribs, Cheng Jiang, Baolin Wan, John Omboko

Civil and Environmental Engineering Faculty Research and Publications

The bond between external bonding (EB) of fiber reinforced polymer (FRP) composite materials to concrete is the weakest link in the strengthened concrete flexural members. There are three mechanisms to transfer the interfacial shear between FRP and the concrete substrate, i.e., adhesion, interlocking and friction. This paper proposes a new approach by grooving on the concrete surface before applying epoxy to make epoxy ribs to increase interlocking. An experimental program was conducted to verify the effectiveness of the proposed epoxy ribs. Six grooves perpendicular to the fiber direction were cut on the bonding surface of the concrete blocks. The grooves …

Bs News January/February

Building Services Engineering

No abstract provided.

Life Is A Lab: Developing A Communication Research Lab For Undergraduate And Graduate Education, Autumn P. Edwards, Chad Edwards, Patric R. Spence

Journal of Communication Pedagogy

Tips offered center on classroom discourse, curriculum choices, and potential assignments. In this article, we present tips for creating a thriving undergraduate and graduate communication research lab. Based on our experiences developing and co-directing the Communication and Social Robotics Labs (CSRLs), we offer 10 best practices for acquiring resources and recognition, building a strong lab community, and attaining faculty and student goals for scholarship and beyond. Our overarching approach is framed by Dewey’s (1916) pragmatist educational metaphysic, which stresses student- and subject-centered learning, enlarging experiences, and the co-construction of meaning and knowledge. Although our labs are focused on human-machine communication …

Experienced Mental Workload, Perception Of Usability, Their Interaction And Impact On Task Performance, Luca Longo

Articles

No abstract provided.

Investigating The Application Of Deep Convolutional Neural Networks In Semi-Supervised Video Object Segmentation, Jayadeep Sasikumar

Dissertations

This thesis investigates the different approaches to video object segmentation and the current state-of-the-art in the discipline, focusing on the different deep learning techniques used to solve the problem. The primary contribution of the thesis is the investigation of usefulness of Exponential Linear Units as activation functions for deep convolutional neural architectures trained to perform object semi-supervised segmentation in videos. Mask R-CNN was chosen as the base convolutional neural architecture, with the view of extending the image segmentation algorithm to videos. Two models were created, one with Rectified Linear Units and the other with Exponential Linear Units as the respective …

Is It Worth It? Budget-Related Evaluation Metrics For Model Selection, Filip Klubicka, Giancarlo Salton, John D. Kelleher

Conference papers

Projects that set out to create a linguistic resource often do so by using a machine learning model that pre-annotates or filters the content that goes through to a human annotator, before going into the final version of the resource. However, available budgets are often limited, and the amount of data that is available exceeds the amount of annotation that can be done. Thus, in order to optimize the benefit from the invested human work, we argue that the decision on which predictive model one should employ depends not only on generalized evaluation metrics, such as accuracy and F-score, but …

Whispering-Gallery Mode Microsphere Resonators For Applications In Environmental Sensing, Arun Mallik

Doctoral

Humidity, temperature and volatile organic compounds (VOCs), particularly ammonia, are key environmental conditions that have a major impact on human comfort, well-being and productivity, as well as on agriculture, food processing and storage, electronic manufacturing and many other industries. This results in the urgent need for the development of sensing technologies allowing rapid detection and accurate measurement of these environmental parameters. Over the past decades many electrical as well as optical sensors have been proposed and demonstrated for environmental applications. However, challenge always exists for these sensors in terms of sensitivity, selectivity, detection limit, speed of response and robustness, where …

Scope Management Strategies For Engineering Leaders To Improve Project Success Rates, Kevin Lee Ramage

Walden Dissertations and Doctoral Studies

Civil engineering projects undertaken without successful implementation of scope management strategies by project leaders are approximately 10% more likely to fail than projects undertaken with scope management strategies. Using scope management theory, the purpose of this single case study was to explore scope management strategies used by some project leaders in the engineering field to improve project success rates. Data were collected using semistructured interviews with 3 purposefully selected project leaders in Georgia, and a review of project completion reports, budget reports, government proposals, and scope management documents. Data analysis occurred using Yin's 5-step process of compiling, disassembling, reassembling, interpreting, …

A Study Of The Product Development Process For The Stackable Shelf, Stool, And Table, Harleigh Elizabeth Huggins

Honors Theses

The purpose of this project was to create a viable furniture product by utilizing the various phases of the product development process. The project began in Phase 0 with market research, formulation of an initial idea, and a product pitch to an executive board to check the viability of the idea. Then, the idea was developed into a concept with Phase 1 by finalizing an initial concept and looking into the potential customer. Next, the product concept was prototyped through several iterations of trial and error in Phase 2. By Phase 3, the product design was finalized, and an initial …

Targeting Metastatic Breast Cancer With Statin Drugs And Coq10, Jacob Thrasher

Honors Theses

Statin drugs are commonly prescribed to lower cholesterol levels in patients, but recently statins have been under investigation as a potential anti-cancer drug. Statins are HMG-CoA reductase inhibitors and subsequently inhibit the mevalonate pathway and cholesterol synthesis. Since cholesterol trafficking is vital in the growth and metastasis of cancer, statin drugs are being studied to explore their effects on cancer cells. CoQ10, one of the products from the mevalonate pathway, also has shown some potential anti-cancer properties, but its use to combat cancer is controversial. While some studies have shown that CoQ10 supplements can be synergistic with other cancer treatment …

Cm-Dii And Mcf-7 Breast Cancer Cell Responses To Chemotherapeutic Agents, Ashten M.C. Anderson

Honors Theses

CM-DiI is a lipophilic, red fluorescent dye used for staining and tracking the migration of cells. CM-DiI makes it possible to visualize cells in histological regions and can therefore be very useful for the tracking of cancer cell proliferation and metastasis in vivo. The ability to track and quantitate cancer cell proliferation in vivo is essential for cancer drug discovery. If CM-DiI labeled cancer cells respond to chemotherapy agents similar to unlabeled cancer cells, it facilitates screening of potential anti-cancer compounds using CM-DiI labeled cells in a xenotransplanted, transgenic zebrafish model (Danio rerio). To investigate whether CM-DiI labeling would affect …

The Development And Optimization Of An Ethylbenzene Process, Aynslie Fritz

Honors Theses

The purpose of this thesis was to optimize a pre-existing vapor phase ethylbenzene process, and to develop a base case liquid phase ethylbenzene process. A brief introduction is included to present an overview of process optimization and suggest common strategies to employ. While optimizing the vapor phase process, discrete optimization was performed to determine the local optima for multiple unit operations by comparing their net present value to that of the base case. After optimization, an $81.5 million increase in net present value was obtained. When developing the liquid phase ethylbenzene process, Antoine's Equation, Raoult's Law, the first law of …

Analysis Of Eeg Coherence During Active Suppression In Patients With Tourette's Syndrome, William Kalusche

Honors Theses

One of the first studies that investigated quantitative qualities of Tourette syndrome (TS) found that during active suppression of tics TS patients exhibit increased coherence in the alpha frequency (Serrien, Orth, Evans, Lees, & Brown, 2005). In this study, we attempted to validate the previous literature to allow for future research into the role played by increased coherence during active suppression. Our findings,however, showed that there was no significant increase in coherence between active suppression and rest. The findings in this study, along with previous literature, may suggest that TS patients with comorbid obsessive-compulsive disorder (OCD) affect the alpha power …

Nonlinear Computational Analysis Of Postural Stability And Its Relationship To Estrogen Deficiency In Postmenopausal Women, Zachary Mitchell

Honors Theses

This study aims to determine if multi-scale entropy analysis will more accurately differentiate the postural stability of postmenopausal women as a function of their estrogen status than traditional measures of postural assessment. The study participants included 7 non-Hormone Replacement Therapy (HRT) postmenopausal women (mean age = 57) and 4 HRT postmenopausal women (mean age = 55). Postural stability was measured with the NeuroCom Equitest and the use of conditions 1-4 of the Sensory Organization Test (SOT). The subjects received an equilibrium score for each condition with a score near 100 representing good postural stability. A modification of the Multi-Scale Entropy …