Mechanical Engineering Commons^™

All-Optical Photoacoustic Detection Of Absorbers In Tissue Phantoms, Jami Johnson, Michelle Sabick, Kasper Vanwijk

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Visualizing and characterizing vascular structures is important for many areas of health care, from accessing difficult veins and arteries for laboratory testing, to diagnosis and treatment of cardiovascular disease. Photoacoustic (PA) imaging, one of the fastest growing fields of biomedical imaging, is well suited for this task. PA imaging is based on the photoacoustic effect, which starts with a pulsed laser source incident on biological tissue. If the wavelength of the source matches an absorption wavelength of a chromophore within the tissue, a portion of the pulse energy is absorbed by the chromophore and converted into heat. A subsequent increase …

Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan

Student Publications & Research

Ordered arrays of high-aspect-ratio micro/nanostructures in semiconductors stirred a huge scientific interest due to their unique one-dimensional physical morphology and the associated electrical, mechanical, chemical, optoelectronic, and thermal properties. Metal-assisted chemical etching enables fabrication of such high aspect ratio Si nanostructures with controlled diameter, shape, length, and packing density, but suffers from structure deformation and shape inconsistency due to uncontrolled migration of noble metal structures during etching. Hereby the authors prove that a Ti adhesion layer helps in stabilizing gold structures, preventing their migration on the wafer surface while not impeding the etching. Based on this finding, the authors demonstrate …

Computational Modeling And Experimental Study On Optical Microresonators Using Optimal Spherical Structure For Chemical Sensing, Hanzheng Wang, Lei Yuan, Jie Huang, Xinwei Lan, Cheol-Woon Kim, Lan Jiang, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

Chemical sensors based on optical microresonators have been demonstrated highly sensitive by monitoring the refractive index (RI) changes in the surrounding area near the resonator surface. In an optical resonator, the Whispering Gallery Modes (WGMs) with high quality (Q) factor supported by the spherical symmetric structure interacts with the contiguous background through evanescent field. Highly sensitive detection can be realized because of the long lifetime of the photons. The computational models of solid glass microspheres and hollow glass spheres with porous wall (PW-HGM) were established. These two types of microresonators were studied through simulations. The PWHGM resonator was proved as …

Design And Development Of A Low Cost Platform To Facilitate Post-Stroke Rehabilitation Of The Elbow/Shoulder Region, Stephen Curran

Masters

For post-stroke rehabilitation of the upper limbs, increased amounts of therapy are directly related to improved rehabilitation outcomes. As such, a low cost therapy platform is proposed suitable for facilitating active therapy and administering activeassist therapy to the shoulder/elbow region of the upper limbs of individuals post-stroke in a local clinic or domestic setting. Enabling a person to undergo intensive rehabilitation therapy outside of a rehabilitation hospital setting permits the amount of therapy administered to be maximised. While studies have shown that technological approaches to post-stroke rehabilitation do not produce better outcomes than equal amounts of traditional therapy in a …

Implementation Of A Plastically Dissipated Energy Criterion For Three Dimensional Modeling Of Fatigue Crack Growth, Parag G. Nittur, Anette M. Karlsson, Leif A. Carlsson

Mechanical Engineering Faculty Publications

Fatigue crack growth is simulated using three dimensional elastic-plastic finite element analysis. The crack extension per load cycle, da/dN, as well as crack front profile changes (crack tunneling) under cyclic loading is not specified as an input but evaluated based on a condition that relates plastically dissipated energy to a critical value. Simulation of cyclic crack propagation in a middle-crack tension M(T) specimen using this implementation captures the well established, experimentally obtained crack growth rate reduction accompanying a single overload event. The analysis predicts that the single overload also affects the crack front profile, where a tunneling crack propagates with …

Multi-Axis Planning Of A Hybrid Material Deposition And Removal Combined Process, J. Zhang, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Qualitative Methods Used To Develop And Characterize The Circulation Control System On Cal Poly's Amelia, Eric N. Paciano

Master's Theses

The circulation control system onboard Cal Poly's Advanced Model for Extreme Lift and Improved Aeroacoustics was a critical component of a highly complex wind tunnel model produced in order to fulfill the requirements of a NASA Research Announcement awarded to David Marshall of the Aerospace Engineering Department. The model was based on a next generation, 150 passenger, regional, cruise efficient, short take-off and landing concept aircraft that achieved high lift through circulation control wings and over-the-wing mounted engines. The wind tunnel model was 10-ft in span, used turbine propulsion simulators, and had a functioning circulation control system driven from tunnel …

Me-Em Enewsbrief, September 2013, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Study Of A Molten Carbonate Fuel Cell Combined Heat, Hydrogen And Power System: End-Use Application, Tarek A. Hamad, Abdulhakim Amer A. Agll, Yousif M. Hamad, Sushrut Bapat, Mathew Thomas, Kevin B. Martin, John W. Sheffield

Engineering Management and Systems Engineering Faculty Research & Creative Works

To address the problem of fossil fuel usage and high greenhouse gas emissions at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and greenhouse gas emissions. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed the design of CHHP system for the campus using local resources. An energy flow and resource availability study is performed to identify the type and source of feedstock required to continuously run the …

Profile Synthesis Of Planar Variable Joints, Brian James Slaboch

Dissertations (1934 -)

Reconfigurable mechanisms provide quick changeover and reduced costs for low volume manufacturing applications. In addition, these mechanisms provide added flexibility in the context of a constrained environment. A subset of planar reconfigurable mechanisms use variable joints to provide this added adaptability.

In this dissertation, the profile synthesis of planar variable joints that change from a rotational motion to a translational motion was investigated. A method was developed to perform automated profile synthesis. It was shown that combinations of higher variable joints can be used to create kinematically equivalent variable joints that are geometrically different.

The results were used to create …

Coupling Rotation And Lamination Theory With Product Development To Create Barriers To Reverse Engineering, Stephen P. Harston, Dr. Christopher A. Mattson

Journal of Undergraduate Research

Introducing a novel product into the market place inevitably invites competitors to reverse engineer it; enabling them to determine proprietary trade secrets and decrease potential profits. Unfortunately, there are relatively few barriers to reverse engineering and the few that do exist are not easily implemented. We will show how a numerical optimization method was used to search for improved material properties in metals as obtainable by the rotation and lamination theory as defined below. These improved material properties are generally thought to be unobtainable in metals and results in unexpected (yet desirable) performance, thus a barrier to reverse engineering is …

Pegleg Crutch, Levi Leishman, Darrel Zeltner

Journal of Undergraduate Research

The progress of a cheap, simple and practical substitute for the common crutch for us has had many design improvements and successes in this year. We were able to meet with medical, educational, and engineering professionals who were all able to input their criticisms and advice. We have decided on a final design that is not the best design for use, but the best when considering cost. See figure 1 for a visual of the final design.

Unilateral Human Vocal Fold Stiffness, Paul Gollnick, Dr. Scott Thomson

Journal of Undergraduate Research

Sounds produced in human speech originate from the vocal folds (also known as vocal chords). In order to speak, the vocal folds must close together. Air is then forced between them causing the folds to vibrate and produce sound.

Improvement Of Body-Powered Prostheses Using Supplemental Power, Kasey Greenland, Dr. Mark Colton

Journal of Undergraduate Research

Many upper-limb amputees are fitted with body-powered prostheses. These are typically operated by the user wearing a harness and making a certain body movement. That movement pulls a cable which then moves the terminal device, which may be an artificial hand or a hook, to perform desired functions. With such prostheses the user is typically limited in their use of the individual fingers and many opt for a hook. Some have voluntary-closing terminal devices, meaning that the hand is in an open position when no force is applied . Though these devices are useful, they often do not provide the …

Investigation Of The Effects Of Intraosseous Pressure Rise In The Formation Of Spinal Burst Fractures: A Biphasic Material Approach, Spencer Shore, Dr. Anton Bowden

Journal of Undergraduate Research

Burst fractures are high-speed spine injuries caused by rapid axial compression of the vertebrae. The traditional explanation for the burst fracture mechanism points to an intraosseous pressure rise due to the entrance of the intervertebral disc through a fractured endplate. Recent experiments [1], however, indicate an actual decrease in both internal pressure and hydraulic resistance in high-speed tests that result in burst fractures. These results cast doubt on the validity of the traditional burst fracture theory. The current study seeks to model the intraosseous pressure rise using the finite element method. In this model, the trabecular core and marrow of …

High-Resolution Bulk Measurement Of Crystal Defects During Deformation Of Highly Textured Copper, Colin Landon, Dr. Brent Adams

Journal of Undergraduate Research

Plastic deformation of crystalline materials is accommodated by crystallographic slip, and the formation and motion of dislocations. Of particular interest to deformation predictions are the dislocation structures that form internal to grains (i.e. the cellular structures), because of their impact on the plastic behavior of the crystal. However, no generally acceptable models that link the dislocation structures and crystal plasticity exist, as is shown by the number of new theories emerging in the literature.

Csf Sniffer Final Report, Alyssa Huber, David Miller, Dr. Brian Jensen

Journal of Undergraduate Research

The purpose of our research was to create a tool to help in the treatment of hydrocephalus; hydrocephalus is a disease in which an obstruction causes a build-up of cerebral spinal fluid (CSF), a liquid found in the brain. Artificial shunts or passageways are used to relocate excess CSF in the treatment of hydrocephalus. Shunts are commonly misplaced, further aggravating patients’ symptoms. We developed an instrument, the CSF Sniffer, to increase the accuracy of shunt placement; it informs the neurosurgeon of the location of the instrument tip in the brain by measuring the intensity of light reflected off the brain. …

Collision Avoidance Using Haptic Feedback For A Quadrotor Helicopter, Adam Brandt, Dr. Mark Colton

Journal of Undergraduate Research

The remote operation of a quadrotor unmanned aerial vehicle (UAV) presents unique challenges to the pilot. When flying a traditional aircraft a camera can be directed so that the field of view points out the nose, which is always in the direction of flight, assuming small side-slip angles. Using this camera, a remote pilot can always see obstacles that the aircraft is approaching and respond appropriately to avoid them.

The Influence Of Superhydrophobicity On Laminar Jet Impingement And Turbulent Flow In A Channel With Walls Exhibiting Riblets, Joseph Fletcher Prince

Theses and Dissertations

The object of this work is to explore the influence superhydrophobic (SH) surfaces exert in laminar jet impingement and when they are combined with riblets in turbulent channel flow. A SH surface generates an apparent slip due to the combination of micropatterning and chemical hydrophobicity. Because of surface tension, water does not enter the cavities between the features, increasing the contact angle of a water droplet on the surface and reducing the liquid-solid contact area. An analysis based on the integral momentum approach of Karman and Pohlhausen is presented that predicts jet impingement behavior on SH surfaces. The model is …

A Parametric Study On Power Variation For Model Wind Turbine Arrays, Dominic Delucia

Dissertations and Theses

This thesis presents the results of wind tunnel experiments performed for various model wind turbine arrays. The aim is to understand how siting affects power output. To optimize wind farm efficiency the experiments vary the parameters of the model wind turbines and the layout of the wind turbine array. The parameters include the alignment, height, spacing, and the rotational direction of the model wind turbines. These experiments employ mechanical torque sensors to simultaneously measure the torque and rotor angular velocity, which yields a direct measurement of the fluid mechanical power extracted by the turbine at multiple locations. For a 4 …

Thermal Transport To Sessile Water Droplets On Heated Superhydrophobic Surfaces Of Varying Cavity Fraction, Robb C. Hays

Theses and Dissertations

The hydrophobicity of a surface is defined as the degree to which it repels water molecules, and the internal contact angle that the droplet makes with the surface is a measure of the hydrophobicity. Contact angles less than 90° occur on hydrophilic surfaces, while contact angles greater than 90° occur on hydrophobic surfaces. If a surface's contact angle is greater than 120° the surface is commonly defined as superhydrophobic (SH). Superhydrophobicity is accomplished through a combination of microscale surface roughness and water repellant surface chemistry. The roughness creates cavities, or pockets, of vapor underneath the droplet which act to increase …

Identification Of Markov Processes Within A Wind Turbine Array Boundary Layer, Matthew Scott Melius

Dissertations and Theses

The Markovianity within a wind turbine array boundary layer is explored for data taken in a wind tunnel containing a model wind turbine array. A stochastic analysis of the data is carried out using Markov chain theory. The data were obtained via hot-wire anemometry thus providing point velocity statistics. The theory of Markovian processes is applied to obtain a statistical description of longitudinal velocity increments inside the turbine wake using conditional probability density functions. It is found that two and three point conditional probability density functions are similar for scale differences larger than the Taylor micro-scale. This result is quantified …

Analysis Of Prosthetic Leg Shock Absorption And Structure, Russell Dibb, David Williams, Dr. Mark Colton

Journal of Undergraduate Research

The purpose of the prosthetic leg project was to research and design a below-the-knee prosthetic leg that could be used in developing countries. Many prosthetic legs that are currently on the market are very expensive and difficult to manufacture in undeveloped areas of the world. The engineering challenges that the prosthetic leg design addressed include a device that is 1) capable of being manufactured at a low cost ($100-$500), 2) simply and easily reproducible in a developing country, 3) durable enough to hold up to the vigorous conditions that exist in a developing country, and 4) able to effectively modeling …

Parametric Human Spine Model, Simeon Smith, Dr. Anton Bowden

Journal of Undergraduate Research

Three-dimensional computer models are commonly used to understand and analyze pathological conditions of the spine. Models of the spine are most beneficial when they match each patient’s spinal geometry. Currently, making a model for a specific patient is a long, multi-step process that must be started anew for each person. The goal of this project was to create a parametric model that can be used to instantly generate the spinal geometry of any particular patient based on the input of a few controlling parameters.

Development Of A Simple Manufacturing Process For A Prosthetic Leg, Kyle Smith, Dr. Mark Colton

Journal of Undergraduate Research

The purpose of this project was to develop a simple process to manufacture a useful and affordable prosthetic leg to be made available to below-the-knee amputees in a sub-Saharan African country. This project was motivated by a desire for learning and experience and also by humanitarian and social entrepreneurship ideals. The project was carried out as a joint effort by a larger research team composed of members of the BYU Biomedical Engineering Club. As this was a joint team effort, many of the tasks detailed in this report were shared between several team members. Currently, the team has identified partners …

Sustainable Bulding Materials In Mozambique, Jared Geddes, Dr. Robert Todd

Journal of Undergraduate Research

The research that I conducted this year was in the area of sustainable building materials. I worked with a team of six engineers to develop a sustainable building material that would be able to withstand the heavy monsoon rains common to the area of Beira, Mozambique. Every year, these rains destroy up to 60% of the local buildings, consisting mainly of local residences made from mud, straw, and sticks. This destruction and the resultant flooding causes an unsafe and unsanitary condition for the local residents. One of the most dangerous aspects of this flooding is the problem of the sanitation. …

Development Of A Simple Manufacturing Process For A Prosthetic Leg, John Christiansen, Dr. Mark Colton

Journal of Undergraduate Research

The purpose of this project was to develop a simple process to manufacture a useful and affordable prosthetic leg to be made available to below-­‐the-­‐knee amputees in a sub-­‐ Saharan African country. This project was motivated by a desire for learning and experience and also by humanitarian and social entrepreneurship ideals. The project was carried out as a joint effort by a larger research team composed of members of the BYU Biomedical Engineering Club. As this was a joint team effort, many of the tasks detailed in this report were shared between several team members. Currently, the team has identified …

Prosthetic Leg Project, Carl Ellingson

Journal of Undergraduate Research

The idea of this project was to research prosthetic leg designs in an effort to create a below-the-knee prosthetic device. The goal was to come up with a device that could be used in third world countries where the need is most considerable. In the past year we have come up with a design and are still in the process of testing the leg. We did not finish as fast as we would have liked, and we are still working on additional testing before we can present our idea to the scholarly community.

Pace Global Collaboration Race Car Project And Pace Emerging Market Engine Project, Jesse Davis, Dr. C. Greg Jensen

Journal of Undergraduate Research

I have been involved with Partners for the Advancement of Collaborative Engineering Education (PACE) since January 2008. The goal of this organization involving industry sponsors and student teams is to teach and foster engineering collaboration in today’s global market. Various projects are undertaken in PACE, but the main focus is design and engineering in the automotive field. I participated in two projects during the past year.

Analysis Of Prosthetic Leg Shock Absorption And Structure, David Williams, Russell Dibb, Dr. Mark Colton

Journal of Undergraduate Research

The purpose of the prosthetic leg project was to research and design a below-the-knee prosthetic leg that could be used in developing countries. Many prosthetic legs that are currently on the market are very expensive and difficult to manufacture in undeveloped areas of the world. The engineering challenges that the prosthetic leg design addressed include a device that is 1) capable of being manufactured at a low cost ($100-$500), 2) simply and easily reproducible in a developing country, 3) durable enough to hold up to the vigorous conditions that exist in a developing country, and 4) able to effectively modeling …