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Articles 841 - 870 of 1828

Full-Text Articles in Engineering

Coupling Of Oxidation-Reduction Reactions Of Chromium, Iron And Manganese: Implications For The Fate And Mobility Of Chromium In Aquatic Environments, Chao Pan Dec 2017

Coupling Of Oxidation-Reduction Reactions Of Chromium, Iron And Manganese: Implications For The Fate And Mobility Of Chromium In Aquatic Environments, Chao Pan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Both within the United States and internationally, hexavalent chromium (Cr(VI)) is a contaminant of concern in drinking water supplies. The U.S. Environmental Protection Agency is considering a Cr(VI)-specific standard. Thus improved technologies for Cr(VI) removal in drinking water are needed. Iron electrocoagulation for Cr(VI) removal was examined at conditions directly relevant to drinking water treatment, and humic acid (HA) affects the performance of electrocoagulation in multiple ways. The success of the chromium treatment or remediation also relies on the stability of the Cr(III)-containing solids with respect to reoxidation under groundwater conditions. Manganese is ubiquitous in aquatic and terrestrial environments, and …

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Bio-Inspired Multi-Spectral And Polarization Imaging Sensors For Image-Guided Surgery, Nimrod Missael Garcia Dec 2017

Bio-Inspired Multi-Spectral And Polarization Imaging Sensors For Image-Guided Surgery, Nimrod Missael Garcia

McKelvey School of Engineering Graduate Student Theses & Dissertations

Image-guided surgery (IGS) can enhance cancer treatment by decreasing, and ideally eliminating, positive tumor margins and iatrogenic damage to healthy tissue. Current state-of-the-art near-infrared fluorescence imaging systems are bulky, costly, lack sensitivity under surgical illumination, and lack co-registration accuracy between multimodal images. As a result, an overwhelming majority of physicians still rely on their unaided eyes and palpation as the primary sensing modalities to distinguish cancerous from healthy tissue. In my thesis, I have addressed these challenges in IGC by mimicking the visual systems of several animals to construct low power, compact and highly sensitive multi-spectral and color-polarization sensors. I …

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Bi-Axial Tissue Stretching Machine: Mems 411 Senior Design Project, Wending Zhu, Martin Valkov, Jordan Patterson Dec 2017

Bi-Axial Tissue Stretching Machine: Mems 411 Senior Design Project, Wending Zhu, Martin Valkov, Jordan Patterson

Mechanical Engineering Design Project Class

This report contains information on the development of a device to strain polyvinyl alcohol hydrogel samples. The device was made with the purpose of gathering data on the creation of anisotropy in brain tissue-like materials, such as PVA, by repeatedly subjecting materials to strain in low temperatures.

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Asme Soccer Robot- Group V, Gonzalo Berluzconi, Lyndon Zhao, Chan-Hwi Cho Dec 2017

Asme Soccer Robot- Group V, Gonzalo Berluzconi, Lyndon Zhao, Chan-Hwi Cho

Mechanical Engineering Design Project Class

The ASME design challenge, featuring a soccer playing robot theme, was attempted and successfully completed. A robot was built that could move in all directions for translational motion, while a Foosball inspired kicking function completed the design.

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Tissue Stretcher Research Device, Taylor Vitunic, Zhang Liu, Edward Tiemann Dec 2017

Tissue Stretcher Research Device, Taylor Vitunic, Zhang Liu, Edward Tiemann

Mechanical Engineering Design Project Class

This senior design project resulted in a prototype of a tissue stretcher for a particular need in a lab at WashU. The prototype uses a stepper motor, micrometer, force transducer, linear slide, and manufactured couplings to precisely record the stress strain response of a bio-tissue through different protocols. This is a holistic report encompassing all parts of the design process from the initial goal to design creation and evaluation to assembly.

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3d Printed Below-The-Knee Prosthetic Leg, Sam Jamison, Katelin Fournier, Isabelle Agostini Dec 2017

3d Printed Below-The-Knee Prosthetic Leg, Sam Jamison, Katelin Fournier, Isabelle Agostini

Mechanical Engineering Design Project Class

There are over 2 million amputees in the United States and more than 90 percent of amputations done today are for lower limbs. While there are highly advanced options on the market today, there are still several areas of improvement. For instance, there are not many options that are completely waterproof, and the more advanced ones are extremely expensive and heavy. Our project idea is to create a below-the-knee prosthetic leg that is water resistant, affordable, and promotes comfort. The leg will be designed to disperse the loads and stresses over the whole structure using 3D printing and supporting metal …

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Light Activated Blinds Group K, Griffin Beriont, Kessashun Arthur, Madeline Stadler Dec 2017

Light Activated Blinds Group K, Griffin Beriont, Kessashun Arthur, Madeline Stadler

Mechanical Engineering Design Project Class

The purpose of this project is to develop an attachable device to a pair of rolling blinds that will automatically open them when sunlight is detected and close them when the sun goes down. This device will promote energy efficiency during warmer and colder months. And be a commodity for those who tend to forget to open close blinds.

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Threading Mechanism For A Home Warp Knitting Machine, Daniel Martin, Samuel Fortmann, Andrew O'Sullivan Dec 2017

Threading Mechanism For A Home Warp Knitting Machine, Daniel Martin, Samuel Fortmann, Andrew O'Sullivan

Mechanical Engineering Design Project Class

A home warp knitting machine has a huge disadvantage compared to weft knitting in that it is very difficult to start up. Though it can provide better quality garments, each needle requires a thread to be individually loaded. If this problem could be mechanically solved, a home warp knitting machine would be feasible. Our machine should be able to spool out the appropriate amount of thread onto smaller spools which can then be loaded into the various needles. However it is able to do this, it should not take up more space than reasonably allocated by thread volume itself, and …

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Group G: Drink Mixer Ii, Yvette Anguiano, Tristram Wilson, Jacob Rother Dec 2017

Group G: Drink Mixer Ii, Yvette Anguiano, Tristram Wilson, Jacob Rother

Mechanical Engineering Design Project Class

We, group G, want to address the needs of the restaurant industry by facilitating it with the products, alcoholic beverages, that often brings in the most income in a night for the business and for its bartenders. Mixing drinks takes specialized attention, energy, and time and can be a stressful task for bartenders to perform when a restaurant is packed with customers. Waits become longer and drink orders back up until the restaurant empties again. Our group strives to create a product that will ensure each customer is served with fast and efficient service, while still providing the special attention …

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3d Printed Prosthetic Hand, Mark Sullivan, Bryan Oh, Ian Taylor Dec 2017

3d Printed Prosthetic Hand, Mark Sullivan, Bryan Oh, Ian Taylor

Mechanical Engineering Design Project Class

3D printed prosthetic hands are a common medical device for pediatric partial hand patients due to their manufacturability and cost-effectiveness. Current designs employ a single fist grip, but prosthetists agree that the most useful grip is the three-finger chuck. We aim to modify an existing 3D printed prosthetic hand to enable the user to switch between a single fist grip and three-finger chuck as well as lock the grip that is being used.

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Cloth Folding Machine, Yiwei Liu, Dung Tran, Kexin Wang Dec 2017

Cloth Folding Machine, Yiwei Liu, Dung Tran, Kexin Wang

Mechanical Engineering Design Project Class

The project was designed to meet the needs of folding clothes for college students, housewives or anyone who has trouble folding clothes. Lots of college students are annoyed by spending time folding clothes based on our customer interviews. In addition, most of clothes folding machine in market are either for industry use or too expensive. We are trying to build a portable automatic clothes folding machine at a cheap cost to serve most people. It not only combined the metrics from existing products but also have two folding patterns, which is more convenient and efficient.

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Blind-Automation Device, Melinda Lai, Dalton Nonweiler, Haley Nichols Dec 2017

Blind-Automation Device, Melinda Lai, Dalton Nonweiler, Haley Nichols

Mechanical Engineering Design Project Class

This project is intended to be a safe, easy, and inexpensive addition to existing window covers to maintain consistent indoor lighting by automatically adjusting blinds in response to ambient light levels. Our target customers are homeowners/renters and business owners concerned about employee productivity and wellness. This product will allow homeowners, business owners, and building tenants to increase occupant productivity. Bright sunlight can cause glare, making employees uncomfortable and reducing their productivity, along with their health. The product will automatically adjust window blinds to maintain a comfortable interior lighting level, promoting productivity and the bottom line. The product can also reduce …

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Rc Plane Variable Wing Design, Brian Mincks, Cameron Bard, Noah Rowe Dec 2017

Rc Plane Variable Wing Design, Brian Mincks, Cameron Bard, Noah Rowe

Mechanical Engineering Design Project Class

Each year the AIAA (American Institute of Aeronautics and Astronautics) hosts a design competition where college teams design and fly a small, remote-controlled, battery-powered airplane. For this competition, scoring primarily depends upon the following: maximizing payload, maximizing speed, minimizing weight, minimizing wingspan. Since wingspan is a key scoring factor and variable wing geometry is allowed, our design team has decided to design a pivoting wing system that can be remotely activated immediately before and after takeoff and landing respectively.

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Group Q- Automatic Ball Launching Entity, Zachary White, Tim Grote, Joshua Norlin Dec 2017

Group Q- Automatic Ball Launching Entity, Zachary White, Tim Grote, Joshua Norlin

Mechanical Engineering Design Project Class

The goal of the project is to create a machine that can track and aim at a target and deliver a tennis ball at a safe speed. The machine can be calibrated to ensure accurate aim. The application of the product is for entertainment and sports training, with calibration being able to be used to make easy shots for fun, and difficult shot for training. The device uses a two-axis rotation, allowing it to aim up/down and left/right. The device uses a microprocessor to calculate aim based on position of target and knowledge about the strength of the firing mechanism.

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Mems 411 Design Project: Dry Ingredients Dispenser, David Robinson, Maya Wong, Elijah Kessler Dec 2017

Mems 411 Design Project: Dry Ingredients Dispenser, David Robinson, Maya Wong, Elijah Kessler

Mechanical Engineering Design Project Class

No abstract provided.

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Group F Drink Mixer - Mixotron, Rebecca Danielle Stone, Christina Bell, Devon Roell Dec 2017

Group F Drink Mixer - Mixotron, Rebecca Danielle Stone, Christina Bell, Devon Roell

Mechanical Engineering Design Project Class

Bars are a great setting for friends to meet and drink however there aren’t many special features that set one bar apart from the rest. What you won’t find in any bar today is robotic bartender able to make any drink to order. In addition, there are many ways to make certain drinks, allowing for much variation. Automating the cocktail making process eliminates the variation in alcohol levels and in ingredients used. In addition, it guarantees that a customer’s drink will not have anything in it that the customer does not explicitly see. Giving the customer options of existing drinks …

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Automated Color Selector, Mark Mcmillin, Mike Mehaffy, Nicholas Mcmillan, Andrew Krieger Dec 2017

Automated Color Selector, Mark Mcmillin, Mike Mehaffy, Nicholas Mcmillan, Andrew Krieger

Mechanical Engineering Design Project Class

Design, build, and sell a safe automated primary color dye mixer to schools for the purpose of teaching children how 12 secondary colors (and shades) on a color wheel can be made via the primary colors. The user will select the desired color (on a color wheel) and the machine will automatically deposit the correct amount of each primary color to create the selected color (or shade). The dye will diffuse in the cup, to create the desired color. Dye will be used in the machine so that if a mess is made, the cleanup is easy. However, we will …

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Dry Ingredient Dispenser, Group S, 2017, Nick Caywood, Noelle T. Wojciechowsi Dec 2017

Dry Ingredient Dispenser, Group S, 2017, Nick Caywood, Noelle T. Wojciechowsi

Mechanical Engineering Design Project Class

We wanted to come up with a way to automate the process of measuring and dispensing dry ingredients for baking.

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The Automatic Bartender, Richard Wu, Alex Nassar, Keegan Lathrum Dec 2017

The Automatic Bartender, Richard Wu, Alex Nassar, Keegan Lathrum

Mechanical Engineering Design Project Class

The automatic bartender will hold 2 liquors and 2 mixers. When the user selects the option to make a drink, the device will pour out the required amounts of liquid into a container, via tubing that feeds into the container. The container has an internal stirrer to mix the components together, and then empties into a cup. The end result is a finished cocktail, and the machine is designed for residential use.

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Tissue Stretching Device, Usama Ismail, Humza Ismail, Elvir Sarajlic Dec 2017

Tissue Stretching Device, Usama Ismail, Humza Ismail, Elvir Sarajlic

Mechanical Engineering Design Project Class

This tissue loading project consists of designing an apparatus that has two main functions. The first, and most obvious of these, being creating a device that will deform a band or disk of tissue with cells pre-seeded on them uniaxially while recording the stress and strain, specifically strain rate, that is applied to the tissue. While the deformation aspect of this device will be key, an equally important part of this project will be designing a part of our tissue loader that mimics the environmental chamber that the lab already uses or is compatible with the environmental chamber that is …

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2018 Asme Student Design Competition - Group T Senior Design Project, Thomas Hess, Anker Anderson, Drew Daugherty, Jack Dufelmeier Dec 2017

2018 Asme Student Design Competition - Group T Senior Design Project, Thomas Hess, Anker Anderson, Drew Daugherty, Jack Dufelmeier

Mechanical Engineering Design Project Class

The purpose of this project is to create a single soccer playing robot to compete in the 2018 ASME student design competition. The robot, along with spare parts and all other devices must fit inside a 50x50x50 cm box. This robot must be able to traverse the field via remote control and have the ability to control a tennis ball and shoot it with sufficient force.

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Torsional Stiffness Measuring Device, Cheyne Shiroma, Clayton Over, Nadab Wubshet Dec 2017

Torsional Stiffness Measuring Device, Cheyne Shiroma, Clayton Over, Nadab Wubshet

Mechanical Engineering Design Project Class

This device will measure the torsional stiffness of a FSAE race car frame. Our design will apply a torsional load to the frame while simultaneously providing precise measurements required to calculate the applied load, displacement, angular deflection, and torsional stiffness. Unlike the most popular method of testing torsional stiffness by applying load with a lever, our device twists the frame using hydraulic bottle jacks with an integrated pressure gauge. This aspect enables precise control of the twist, and the pressure gauges provide the capability of load-measurement. The validity of measurements will be assessed by comparing results to theoretical calculations.

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Macroscopic Model Of A Cilium Appendage, Laura Barber, Rachel Mickelson, Wilson Roen, Isabella Merz Dec 2017

Macroscopic Model Of A Cilium Appendage, Laura Barber, Rachel Mickelson, Wilson Roen, Isabella Merz

Mechanical Engineering Design Project Class

The goal of this project is to develop a macroscopic model of the cilia appendage and a realistic testing environment for the model. The model should be created with materials that effectively replicate the material and mechanical properties of the appendage in the human body. Additionally, the testing environment should mimic the viscous fluid that surrounds cilia in the human body to allow for more accurate testing. The fluid’s flow should be parallel to the model and induce instability in the system. This instability should force the cilia model to oscillate like a flag in the wind. Upon completion of …

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Modeling Acoustic Microfluidic Phenomena In Unconventional Geometries, Andrew Ledbetter Dec 2017

Modeling Acoustic Microfluidic Phenomena In Unconventional Geometries, Andrew Ledbetter

McKelvey School of Engineering Graduate Student Theses & Dissertations

In this work, the performance of a piezoelectrically-actuated ultrasonic droplet generator is analyzed by modeling the harmonic response of a two-dimensional representation of the device cross-section. Observed vibrational and acoustic resonances provide insight into optimal design conditions to achieve efficient, robust droplet ejection. Numerical simulations highlight the importance of the coupled electrical and mechanical behavior of the resonator assembly and show that elastic modes can effectively amplify or dampen acoustic modes within the fluid chamber. Experimentally-validated modeling results guide development of an optimization strategy to further improve device performance. In addition, the standing acoustic field that is the focus of …

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A Novel Device For Mr Foot Perfusion Stress Testing, David John Muccigrosso Aug 2017

A Novel Device For Mr Foot Perfusion Stress Testing, David John Muccigrosso

McKelvey School of Engineering Graduate Student Theses & Dissertations

No abstract provided.

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Jme 4110 Final Design Report - Plant Growth Chamber, Deontez Myers, Chad Szwargulski Aug 2017

Jme 4110 Final Design Report - Plant Growth Chamber, Deontez Myers, Chad Szwargulski

Washington University / UMSL Mechanical Engineering Design Project JME 4110

To facilitate study of resource use efficiency in crop plants, it is necessary to pulse-saturate them with certain stable isotopes. This is done by exposing the shoots to gases and the roots to liquid. We were tasked with designing a system to deliver and control this process.

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Jme 4110 Seed Cross-Breeze Distance Tester, Ty Krewson, John Jensen, Emily Dahlberg Aug 2017

Jme 4110 Seed Cross-Breeze Distance Tester, Ty Krewson, John Jensen, Emily Dahlberg

Washington University / UMSL Mechanical Engineering Design Project JME 4110

Because seeds vary in shape, size, and weight, their behaviors in cross-breezes vary as well. The customer’s laboratory is researching seeds for prairie grasses. Their laboratory currently has data for seed structures; however, data for seed dispersion is needed to provide a better correlation to known environmental and genetic factors such as precipitation and DNA changes. The Seed Cross-Breeze Distance Tester is a controlled chamber designed to test the distance a seed will travel in a user-specified windspeed.

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Development And Validation For A Mobile Speech-In-Noise Audiometric Task, Tommy Peng Aug 2017

Development And Validation For A Mobile Speech-In-Noise Audiometric Task, Tommy Peng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional speech-in-noise hearing tests are performed by clinicians with specialized equipment. Furthermore, these tasks often present contextually weak sentences in background babble, which are poor representations of real-world situations. This study proposes a mobile audiometric task, Semantic Auditory Search, which uses the Android platform to bypass the need for specialized equipment and presents multiple tasks of two competing real-world conversations to estimate the user’s speech-in-noise hearing ability. Through linear regression models built from data of seventy-nine subjects, three Semantic Auditory Search metrics have been shown to have statistically significant (p < 0.05) with medium effects sizes for predicting QuickSIN SNR50. The internal consistency of the task was also high, with a Cronbach’s alpha of 0.88 or more across multiple metrics. In conclusion, this preliminary study suggests that Semantic Auditory Search can accurately and reliably perform as an automated speech-in-noise hearing test. It also has tremendous potential for extension into automated tests of cognitive function, as well.

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Single-Step, Atmospheric Pressure Chemical Vapor Deposition Of Methylammonium Bismuth Iodide Thin Films, Xiao Chen Aug 2017

Single-Step, Atmospheric Pressure Chemical Vapor Deposition Of Methylammonium Bismuth Iodide Thin Films, Xiao Chen

McKelvey School of Engineering Graduate Student Theses & Dissertations

Lead halide perovskites (CH3NH3PbI3 and its variants) are promising solar cell absorber materials. Though the reported power conversion efficiencies of lead halide perovskite solar cells (up to 21%) are competitive with commercial silicon solar cells, lead toxicity in these perovskites present a challenge to further scale-up and eventual commercialization. Recently, bismuth (Bi3+) based organic halide perovskite has drawn attention as a substitution for lead-free perovskites, since it is a non-toxic 6p-block element, isoelectronic with Pb2+. Methylammonium bismuth iodide ((CH3NH3)3Bi2I9) is reported …

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Cfd Performance Of Turbulence Models For Flow From Supersonic Nozzle Exhausts, Han Ju Lee Aug 2017

Cfd Performance Of Turbulence Models For Flow From Supersonic Nozzle Exhausts, Han Ju Lee

McKelvey School of Engineering Graduate Student Theses & Dissertations

The goal of this thesis is to compare the performance of several eddy-viscosity turbulence models for computing supersonic nozzle exhaust flows. These flows are of relevance in the development of future supersonic transport airplane. Flow simulations of exhaust flows from three supersonic nozzles are computed using ANSYS Fluent. Simulation results are compared to experimental data to assess the performance of various one- and two-equation turbulence models for accurately predicting the supersonic plume flow. One particular turbulence model of interest is the Wray-Agarwal (WA) turbulence model. This is a neat model which has demonstrated promising results mimicking the strength of two …

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