Engineering Commons^™

Multi-Fidelity Surrogate And Reduced-Order Model-Based Microfluidic Concentration Gradient Generator Design, Haizhou Yang

Theses and Dissertations

The microfluidic concentration gradient generator (μCGG) is an important device to generate and maintain concentration gradients (CGs) of biomolecules for understanding and controlling biological processes. However, determining the optimal operating parameters of μCGG is still a significant challenge, especially for complex CGs in cascaded networks. To tackle such a challenge, this study presents multi-fidelity surrogate and reduced-order model-based optimization methodologies for accurate and computationally efficient design of μCGGs.

The surrogate-based optimization (SBO) method is first proposed for the design optimization of μCGGs based on an efficient physics-based component model (PBCM). Various combinations of regression and correlation functions in Kriging and …

Mechanical Strength Of Sic Composite Tubing Under Uniaxial And Multiaxial Loading, Colton Corley

Theses and Dissertations

Silicon carbide fiber reinforced silicon carbide matrix composite is one of the candidate materials for accident tolerant nuclear fuel cladding concepts. In a Nuclear power plant, the reactions between the fuel, cladding, and coolant in a potential loss of coolant accident(LOCA) are of utmost importance to ensure safety in the accident tolerance of such plants. It is for this reason that SiC(silicon carbide) composite tubes have been selected as a possible alternative to the older Zirconium based cladding methods currently used in the industry, which were a partial cause of the Fukushima 2011 meltdown. To serve as fuel cladding, a …

Purification Of Uranium Tetrafluoride Using Ammonium Bifluoride, Kyle Robert Foster

Theses and Dissertations

Molten salt reactors are being deployed as one of the Generation IV nuclear reactor concepts starting in 2025. While their applications and safety potential are considered extremely advantageous, there is a lack of operating history to draw on, so thorough understanding of proposed molten salt materials’ thermochemical behavior is crucial to their successful implementation.

The most prominent fissile fuel proposed for molten salts is uranium tetrafluoride (UF4) using ²³³U of the thorium fuel cycle. UF₄ is extremely hygroscopic, meaning it will react with moisture and oxygen in its environment, so as-received powders contain significant levels of impurity. In …

Fabrication And Characterization Of Micro/Nanostructured Ceramic Device For Energy Conversion, Yun Gan

Theses and Dissertations

The deteriorating climate is threatening our living habitat and arousing public awareness. To achieve the carbon neutral goal by the middle of 21st century, developing novel technologies to reduce CO₂ emission or promote its capture become urgent. Among them, oxygen permeation membrane (OPM) and solid oxide cell (SOC) are two promising devices for clean energy conversion.

In chapter 1, the background of OPM and SOC are briefly introduced. Fundamental mechanism and application of phase inversion, the key process involved in fabrication of hollow fiber OPM and microtubular SOC are emphatically described. Mixed ionic and electronic conducting (MIEC) perovskites demonstrate …

Computer Vision-Based Automatic Railroad Crossing Monitoring And Track Inspection, Feng Guo

Theses and Dissertations

Currently, there are many imminent challenges in the railroad infrastructure system of the United States, impacting the operation, safety, and management of railroad transportation. In this work, three major challenges which are overcrowded traffic congestion at the grade crossing, low-efficiency and accuracy on inspection of missing or broken rail track components, and dense rail surface defects without quantification, respectively are studied. The congested railroad grade crossing not only introduces significant traffic delays to travelers but also brings potential safety concerns to the first responders. However, limited studies have been devoted on developing an intelligent traffic monitoring system which is significant …

Increased Detectivity And Low Temperature Performance Analysis Of Sub-20Μm Micropixel Array A1gan Uv Photodiodes, Samia Islam

Theses and Dissertations

This thesis is divided into two sections. At first, we demonstrate ~1.5x detectivity increase in AlGaN photodiodes on sapphire using distributed micropixel arrays with 5-15 µm pixel diameter. This is due to the ~10x larger chip footprint of the 5um diameter micropixel arrays compared to planar control structures with identical p contact area. The responsivity of the larger areas was the same as that of the control structure despite the larger footprint while the dark currents, an indicator of noise, remained unchanged. The photocurrent generated between pixels was collected due to transmission line effects connecting the pixels separated by 5um, …

Robot Area Coverage Path Planning In Aquatic Environments, Nare Karapetyan

Theses and Dissertations

This thesis is motivated by real world problems faced in aquatic environments. It addresses the problem of area coverage path planning with robots - the problem of moving an end-effector of a robot over all available space while avoiding existing obstacles. The problem is considered first in a 2D space with a single robot for specific environmental monitoring operations, and then with multi-robot systems — a known NP-complete problem. Next we tackle the coverage problem in 3D space - a step towards underwater mapping of shipwrecks or monitoring of coral reefs.

The first part of this thesis leverages human expertise …

Fine Points For Broad Bumps: The Extension Of Rietveld Refinement For Benchtop Powder Xrd Analysis Of Ultra-Small Supported Nanoparticles, Jeremiah W. Lipp

Theses and Dissertations

The goal of this work is to demonstrate the capabilities of benchtop Bragg diffraction in characterizing ultra-small (< 2nm) nanoparticles. To this end we have established a method for accurately separating the background, adjusting for relevant intensity effects, and analyzing the results with Rietveld refinement. This method is applied to the characterization of six silica-supported “noble” metals under ambient conditions: Pt, Pd, Ir, Rh, Ru, and Au. Surprisingly, Bragg diffraction is capable of shining light on this difficult-to-characterize size region – revealing the propensity of these metal nanoparticles to oxidize at room temperature. Preliminary findings for future work are also discussed: extending our method to crystalline supports and fluorescent samples.

The Effect Of Visual Field Manipulations On Standing Balance Control In People With Multiple Sclerosis, Lara I. Riem, Scott A. Beardsley, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Background

Multiple sclerosis (MS) is associated with an increased risk of falls, degeneration of sensory organization, and possible increased reliance on vision for balance control.

Research question

The aim of this study was to assess differences in standing postural control between people with MS and age and sex matched controls during medial-lateral (ML) oscillations of the visual field, with and without blinders to the lower periphery.

Methods

Ten persons with MS (mean age 54.0 ± 5.3 years) and ten age and sex matched controls (mean age: 56.3 ± 6.0 years) participated in this study. Balance control was assessed while participants …

From The Surface To The Reactor: Identifying The Active Sites For Propane Dehydrogenation On Platinum-Based Catalysts Through Density Functional Theory, Experimental Data, And Uncertainty Quantification, Charles Henry Fricke

Theses and Dissertations

Propane dehydrogenation is a critical process of producing propylene, an important feedstock for the chemical industrial. There are multiple key processes to produce propylene in this manner, but one of the largest processes involves non-oxidative dehydrogenation on a platinum-tin alloy based catalyst. In general, these reactions and catalytic particles are complex, with many dehydrogenation, cracking, and reforming reactions taking place during these processes on multiple surfaces. With this in mind, ab initio computational catalysis models are used to generate further insight into these catalytic processes. In this dissertation, there are three aims to be solved: identifying the most likely active …

The Effect Of Low Dose Penicillin On Tumor Development In ApcMin/+ Mice, Kinsey Ann Sierra Meggett

Theses and Dissertations

Antibiotics have been our most effective weapon against bacterial infections since their discovery in the early 1900s. Their use has been critical in reducing mortality rate from infectious diseases. However, in the last few decades, the overuse of antibiotics, beginning at an early age and into adulthood, has become a growing concern globally. Penicillin is one of many extensively used antibiotics in early childhood that has been used to treat childhood infections. Recent studies showed that exposure to low dose penicillin can have adverse effects leading to chronic illness such as diabetes, allergies, inflammation, and susceptibility to obesity, with the …

Mems 411: Safely Capturing Giant African Pouch Rats, Anthony Brown, John Christensen, Jared Harrison

Mechanical Engineering Design Project Class

We were tasked with designing a trap to safely capture Giant African Pouch Rats. The traps are used in both urban and rural environments that include city streets, basements, farms, river beds, and bushes among other locations. Pouch rats are much larger than most rats and are a very ferocious species; they will harm themselves if there are any non-smooth surfaces when captured. It is very important that we designed a trap with this safety top of mind.

Mems 411: The Water Bike, Erin Flynn, Patrick Grindel, Nicholas Payne, Ryan Allin

Mechanical Engineering Design Project Class

This design project explored the concept of a bike that can float on water and be used to assist lifeguards in rescues. The goal was for it to be quickly converted from a road to water configuration and be quick and stable enough to be a useful tool in saving drowning swimmers.

Mems 411: Lost Grains Thresher, Alicia Gupte, Sophie Fox, Dan Heikes, Andrew Waldherr

Mechanical Engineering Design Project Class

The Lost Grains Thresher project aims to design and implement a device that can successfully separate the seed and chaff from various grains that are native to the greater St. Louis area. This project is designed for Dr. Natalie Mueller at Washington University in St. Louis to replace her current method of separating plant seeds from chaff by hand. This project focused on three main performance goals: 1) the device should work on a minimum of two types of seeds and thresh them to an acceptable quality, 2) the device should be easily cleaned and reset within three minutes, and …

Mems 411: Bearing Plate Loader, Daniel Firescu, Treeton Allison, Bethany Starr

Mechanical Engineering Design Project Class

Create a Bearing Plate Loader to move a plate from one location to another.

Mems 411: P.O.T.T.E.R. Test Frame, Marie Drevets, Kiersten Horton, Tony Sancho

Mechanical Engineering Design Project Class

Our senior mechanical engineering design is a flexure test frame. At our university, third-year mechanical engineering students take a class called machine elements, in which the final project is a structural design competition. The students design a strong but lightweight object. The P.O.T.T.E.R. device can be used to judge the structural integrity of students contest entries. The customer who commissioned this project is Dr. Potter, who teaches the machine elements class. The customer needs a portable test frame which can apply enough compressive force to fracture an object which is secured in the device. The test frame should also measure …

Mems 411: Soccer Robot, Sam Ginsberg, Ella Johnson, Aaron Ocken, Andrew Bergantz

Mechanical Engineering Design Project Class

This design project was altered from the 2018 ASME Soccer Robot competition. Dr. Jackson Potter led a competition where groups built remote control robots to compete against each other in 1v1 matches based on a modified rule set from the initial 2018 competition.

Mems 411: The Hash Setting Slasher, Garrett Barber, William Koopman, Andrew Werner, Alexandra Carr

Mechanical Engineering Design Project Class

The volleyball setter has certain patents that utilize some sort of rotational component or is a stationary platform that the ball rests on before the player hits it. Our design is different because it utilizes the mechanical properties of springs to propel the ball forwards. We had certain specifications to meet to allow the volleyball to be natural in its trajectory and able to be shot efficiently and effectively. Some specifications required positioning adjustments and some defined how the ball should be propelled through the air. We also had parameters involving cost, weight, and the repeatability of the mechanism to …

Mems 411: Free Kick Robot, Rahi Miraftab-Salo, Will Goldberg, Wlodie Rebesque

Mechanical Engineering Design Project Class

The free kick robot was designed to help train the club soccer goalkeeper: Brady Shaeffer, to save shots on goal. After a customer interview with the our client, we aimed our design to shoot accurate and powerful shots in quick succession. In addition the robot was to be easily transportable. Initially, after looking at some patents, the most commercially used soccer training robots involved two parallel disks spinning and shooting out soccer balls. As a result an initial prototype was built with this idea. However, during our concept selection, we realized that the cost of building our machine was out …

Mems 411: Soccer Robot Project, Evan Sucherman, Dylan Mitchell, Benjamin Hessman, Emre Koc

Mechanical Engineering Design Project Class

This project aims at designing a robot that is capable of playing a simplified form of soccer against other robots. The original competition was created by the ASME organization as a student design competition in 2018. This project is an adapted version in which some of the rules and guidelines have been changed to fit the goals of this class better. The design parameters for this project include: having the robot drive around the parameter of the playing field in under 17 seconds, having the vehicle successfully capture the ball within 2 seconds of approaching 8 out of times, and …

Mems 411: Rowing Force Plate, Mae Hubel, Taylor Southwick, Miles Petersen

Mechanical Engineering Design Project Class

The Rowing Force Plate is a device that is designed to measure a rower’s force
over time so that they can understand how hard they are rowing. Most rowing
aids communicate the speed at which someone is rowing, which is variant on water
speed, wind speed, and other inconsistent environmental and situational factors.
Force, however, can be consistently measured and is a better indicator of effort a
rower is exerting. Other products that measure force do exist, but use complex and
expensive technology, unlike our design.
After brainstorming and analyzing multiple possible designs, we concluded to use
four force sensors …

Mems 411: Giant Pouched Rat Trap, Ronald Fields, Mariano Gonzalez, Edward Li, Jordan Hu

Mechanical Engineering Design Project Class

Dr. Braude from the Biology department at Washington University in St. Louis is currently working on a project training giant Gambian pouched rats to find mines and other bombs in former conflict zones. In order to trap Gambian pouched rats, Professor Braude asked a few MEMS 411 Senior Design groups to design and build a trap that can safely capture the rats. The trap had to be about 2-3 feet long, 6 inches in diameter, completely mechanical, simple, and it had to cost less than 30 USD to build.

Mems 411: Laundry No Mo (Lnm), Justin Tai, Minju Lee, Logan Johnson, Elijah Stewart

Mechanical Engineering Design Project Class

How can you optimize your time and labor while folding laundry? You can do so with this laundry folding device called Laundry No Mo (LNM).

Mems 411: Volleyball Setter, Alexander Zuga, Liam Cadden, Neil Cumberland, Jacob Ridderhoff

Mechanical Engineering Design Project Class

Our volleyball setting machine is intended for use by the WashU men’s club volleyball team to improve their training. It allows their skilled hitters to get more reps in practice because there currently aren’t enough skilled setters on their team.

Mems 411: The Bueffer 3000, Ty W. Bedillion, Krista Sudar, Anna Oneto, Cole Kocjancic

Mechanical Engineering Design Project Class

We were tasked with creating a quality product for a customer for MEMS 411 Senior Design. Our customer was the Washington University in St. Louis Men's Club Volleyball team and they asked us to create a volleyball setting machine.

Mems 411: Friction Frenzy, Angelo Hawa, Landon Tafoya, Noah Owens

Mechanical Engineering Design Project Class

The demo is designed to demonstrate the concept of friction to younger children(ages 4+) using an incline plane. The premise is to allow the user to slowly elevate a surface until a block resting on top begins to slide, at which point an electronic interface displays the calculated amount (or coefficient) of friction. The core functions of the device are discussed based on the customer needs in order to identify key performance goals for its successful operation. The design process is documented from initial modeling to the final prototype and critical metrics including safety and ease of fabrication are discussed. …

Mems 411: Mini Test Frame, Howard Wu, Max Richter, Baker Blevins, Andrew Issac

Mechanical Engineering Design Project Class

A lightweight, cheap, and portable compression test frame designed for testing students' structural designs for the Machine Elements class. Measures load and displacement applied on the specimen to determine the specimen with the highest strength.

Mems 411: Giant Pouched Rat Trap, Shannon Wang, Isha Shah, Vaishali Shah, Elizabeh Saliba

Mechanical Engineering Design Project Class

Our goal is to design a giant pouched rat trap that meets the customer needs from professor Stan Braude. The giant pouched rats are to be breed and trained to find land mines. Therefore, the rats must be captured in good condition. However, giant pouched rats are not passive once caught and tries to escape every way possible. In the past, with traditional trap wires, they tend to get caught in the wire and hurt themselves. Our solution offers a completely smooth inner wall of the trap to prevent damage to the rats, while improving on the functionality of the …

Mems 411: African Pouched Rat Trap, Kelechi Achilefu, Paul Joseph, David Allen, Chase Green

Mechanical Engineering Design Project Class

What is often thought of as a rat trap is often in reality a mouse trap, or a trap designed to catch small rodents. Rats can be quite large and catching them without harming them can be quite difficult. Current market solutions generally either kill or harm the rodent which is not acceptable for our client's needs. While there are some solutions on the market, they fall short of the needs of our client which is more specialized due to the size of rodent they will be capturing, the circumstances surrounding the capture, the number of rodents our client needs …

Mems 411: Asme Soccer Robot, Braden Arango, Brendan Otani, Florie Markwell

Mechanical Engineering Design Project Class

This project was based off of a variation of the ASME Soccer Robot Competition, where 5 teams were tasked with creating a soccer robot to compete with. The main objective for each team was to create a remote-controlled robot with an integrated shooting mechanism that was capable of shooting a tennis ball, with accuracy, into a goal. A design process was used to create this robot from scratch, where multiple concepts were created and tested through mock-ups and prototypes to better understand the problem at hand. Throughout this process, three main prototype goals were prioritized: the ability to drive around …