Mechanical Engineering Commons^™

A Study Of The Cause Of Failure Of Rotationally Molded, High-Density Polyethylene, Sodium Hypochlorite Storage Tanks, Dixon Harold Abell

Theses and Dissertations

The topic of chemical oxidative degradation in rotational molded polyethylene (high-density cross-linked) chemical (sodium hypochlorite) storage tanks is an industry problem that ranks at the top of current business issues for manufacturers of chemical storage tanks. The degradation of these tanks not only compromises the physical and mechanical properties of the tank material, but reduces the life expectancy of the tank, eventually resulting in catastrophic tank failure. Premature tank failure comes at a hefty cost. The reputation of the manufacturer is questioned often resulting in immediate loss of customer satisfaction and future business. The leaking of the chemical from the …

A Proteolytic Process To Simulate The Mechanics Of Disc Dengeration In Bovine Cadaveric Tissue, Timothy A. Bishop

Theses and Dissertations

Purpose. The present work hypothesized that proteolytic dissolution of intervertebral discs could induce biomechanical change comparable to the change observed in natural disc degeneration. A method to do such could be utilized for in vitro research where intersample differences in geometry and chemical makeup render it difficult to compare and aggregate results into generalized conclusions.
Methods. Forty-one bovine coccygeal intervertebral discs were isolated with individual functional spinal units. Samples were loaded in three modes: compression/tension, flexion/extension, and axial rotation. The anulus fibrosus of each disc was injected with 200µl trypsin or fetal bovine serum (control) and incubated for an allotted …

Shaped Mems Contact, Ronald A. Coutu Jr., Paul E. Kladitis, Robert L. Crane

AFIT Patents

A MEMS switch fabrication process and apparatus inclusive of a bulbous rounded surface movable contact assembly that is integral with the switch movable element and achieving of long contact wear life with low contact electrical resistance. The disclosed process is compatible with semiconductor integrated circuit fabrication materials and procedures and includes an unusual photoresist reflow step in which the bulbous contact shape is quickly defined in three dimensions from more easily achieved integrated circuit mask and etching-defined precursor shapes. A plurality of differing photoresist materials are used in the process. A large part of the contact and contact spring formation …

Disturbance Attenuation In A Magnetic Levitation System With Acceleration Feedback, Feng Tian, Craig Kevin, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

The objective of this work is to demonstrate the use of acceleration feedback to improve the performance of a maglev system, especially in disturbance attenuation. In the single degree-of-freedom (DOF) system studied here, acceleration feedback has the effect of virtually increasing inertia, damping and stiffness. It is shown that it can be used to increase disturbance rejection without sacrificing tracking performance. Both analytical and experimental results demonstrate that disturbance rejection can be improved with acceleration feedback.

Electromagnetic Modeling And Measurement Of Adaptive Metamaterial Structural Elements, Matthew E. Jussaume

Theses and Dissertations

This document addresses two major obstacles facing metamaterial development: uncertainty in the characterization of electromagnetic field behavior in metamaterial structures and the relatively small operational bandwidth of metamaterial structures. To address the first obstacle, a method of prediction aided measurement is developed and exploited to examine the field interactions within metamaterial devices. The fusion of simulation and measurement techniques enhances the understanding of the physical interactions of fields in the presence of metamaterials. To address the second obstacle, this document characterizes the effectiveness of an adaptive metamaterial design that incorporates a microelectromechanical systems (MEMS) variable capacitor. Applying voltages to the …

Sr2Fe1.5Mo0.5O6 As Cathodes For Intermediate-Temperature Solid Oxide Fuel Cells With La0.8Sr0.2Ga0.87Mg0.13O3 Electrolyte, Guoliang Xiao, Qiang Liu, Fei Zhao, Lei Zhang, Changrong Xia, Fanglin Chen

Faculty Publications

The performance of Sr₂Fe_1.5Mo_0.5O₆ (SFMO) as a cathode material has been investigated in this study. The oxygen ionic conductivityof SFMO reaches 0.13 S cm^-1 at 800°C in air. The chemical diffusion coefficient (D_chem) and surface exchange constant (k_ex) of SFMO at 750°C are 5.0 x 10^-6 cm² s^-1 and 2.8 x 10^-5 cm s^-1, respectively, suggesting that SFMO may have good electrochemicalactivity for oxygen reduction. SFMO shows a thermal expansion coefficient (TEC) of 14.5 x 10^-6 K^-1 the …

Building America Industrialized Housing Partnership (Baihp Ii) Final Report Budget Periods 1-5, April 1, 2006 - November 30, 2010, Florida Solar Energy Center, Robert Abernethy

FSEC Energy Research Center®

This report summarizes the work conducted by the Building America Industrialized Housing Partnership (BAIHP - www.baihp.org) during the final budget period (BP5) of our contract, January 1, 2010 to November 30, 2010. Highlights from the four previous budget periods are included for context.

BAIHP is led by the Florida Solar Energy Center (FSEC) of the University of Central Florida. With over 50 Industry Partners including factory and site builders, work in BP5 was performed in six tasks areas:

• Task 1: Building America System Research Management, Documentation and Technical Support
• Task 2A: Stage G1A: Integrated Solutions for Specific Climate Regions
• Task …

Analysis Of Heat Effects On Marine Corps Am2 Mat Mechanical Properties, V. Vega, U. N. Huynh, J. Holmes, J. Dechellis, P. Stoyanov, D. Piatkowski, E. W. Lee, J. Ogren, N. Drusina, Omar S. Es-Said

Mechanical Engineering Faculty Works

Navy AM2 mats are used as portable aircraft landing platforms for the Short Take-off/Vertical Landing (STOVL) aircraft operations. This investigation presents the study performed to determine whether the surface discoloration is a precursor to degradation in the mechanical property of the AM2 mat material. The red discoloration on the mat surfaces had a clear correlation with the decrease in yield strength, ultimate strength, and hardness properties.

A Peridynamic Formulation For Transient Heat Conduction In Bodies With Evolving Discontinuities, Monchai Duangpanya

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Modeling heat flow in bodies with discontinuities, such as cracks, or with inclusions that have different thermal properties has been a very challenging problem. Classical models lead to infinite heat fluxes at the tip of a crack and convergence of numerical methods that approximate solutions to such models have convergence and mesh dependency issues. To remove the difficulties faced by the classical models a novel nonlocal theory is formulated.
The new theory starts from the conservation of energy principle and uses the idea of nonlocal heat-transfer between material points. This idea leads to a transient heat transfer model that does …

Deterministic Integrated Tuning Of Multicavity Resonances And Phase For Slow-Light In Coupled Photonic Crystal Cavities, T. Gu, S. Kocaman, Xiaodong Yang, J. F. Mcmillan, M. B. Yu, G.-Q. Lo, D.-L. Kwong, C. W. Wong

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We present the integrated chip-scale tuning of multiple photonic crystal cavities. The optimized implementation allows effective and precise tuning of multiple cavity resonances (up to ~1.60 nm/mW) and intercavity phase (~0.038 π/mW) by direct local temperature tuning on suspended silicon nanomembranes. Through designing the serpentine metal electrodes and careful electron-beam alignment to avoid cavity mode overlap, the coupled photonic crystal L3 cavities preserve their high quality factors. The deterministic resonance and phase control enables switching between the all-optical analog of electromagnetically-induced-transparency to flat-top filter lineshapes, with future applications of trapping photons and optoelectronic modulators.

Tensile Properties And Microstructures Of Laser-Formed Ti-6al-4v, J. Alcisto, A. Enriquez, H. Garcia, S. Hinkson, T. Steelman, E. Silverman, P. Valdovino, H. Gigerenzer, J. Foyos, J. Ogren, J. Dorey, K. Karg, T. Mcdonald, Omar S. Es-Said

Mechanical Engineering Faculty Works

The room temperature tensile properties of Ti-6Al-4V alloy prepared under two different processing routes were evaluated and compared. One group of samples was prepared by conventional casting-forging-rolling into flat plates. The other group was prepared by using Triton's Laser Free-Form Fabrication (LF3)(TM) processes, i.e., a laser was used to melt pre-alloyed powders of the required metallic composition as they were dropped onto a moveable substrate programmed to move in such a manner as to form a solid alloy plate. Five populations of Ti-6Al-4V were evaluated: a standard wrought form, an as-deposited form, a machined as-deposited form, a heat-treated as-deposited form, …

High-Resolution, Non-Contact Angular Measurement System For Psa/Rsa, Ronald D. Sloat

Master's Theses

A non-contact angular measurement system for Pitch Static Attitude (PSA) and Roll Static Attitude (RSA) of hard disk drive sliders is designed and built. Real-time sampling at over 15 KHz is achieved with accuracy of +/- 0.05 degrees over a range of approximately 2-3 degrees. Measuring the PSA and RSA is critical for hard drive manufacturers to control and improve the quality and reliability of hard drives. Although the hard drive industry is able to measure the PSA and RSA at the subassembly level at this time, there is no system available that is able to measure PSA/RSA at the …

2011 (Spring) Ensi Informer, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 2011.

Predicting Articular Cartilage Constituent Material Properties Following In Vitro Growth Using A Proteoglycan-Collagen Mixture Model, Michael Stender

Master's Theses

      A polyconvex continuum-level  proteoglycan Cauchy stress function was developed based on the continuum electromechanical Poisson-Boltzmann unit cell model for proteoglycan interactions. The resulting proteoglycan model was combined with a novel collagen fibril model and a ground substance matrix material to create a polyconvex constitutive finite element model of articular cartilage. The true collagen fibril modulus , and the ground substance matrix shear modulus , were varied to obtain the best fit to experimental tension, confined compression, and unconfined compression data for native explants and explants cultured in insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1).  Results indicate …

Tower-Tracking Heliostat Array, Joel T. Masters

Master's Theses

This thesis presents a method of tracking and correcting for the swaying of a central receiver tower in concentrated solar production plants.  The method uses a camera with image processing algorithms to detect movement of the center of the tower.  A prototype was constructed utilizing a CMOS camera connected to a microcontroller to control the movements of three surrounding heliostats.  The prototype uses blob-tracking algorithms to detect and correct for movements of a colored model target.  The model was able to detect movements in the tower with average error of 0.32 degrees, and was able to correctly orient the surrounding …

Me-Em Enewsbrief, March 2011, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Fuel Cycle Co2-E Targets Of Renewable Hydrogen As A Realistic Transportation Fuel In Australia, Alberto Boretti

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The claim of catastrophic manmade climate change or global warming through anthropogenic CO₂ has presently focused the interest on the tailpipe emissions of CO₂ per km, with recent legislations obsessively targeting these emissions of CO₂ with defectively implemented procedures. with a variety of different propulsion solutions (electric, hybrid electric, hybrid mechanic, conventional) and different fuels (Diesel, Petrol, alternative fossil, alternative renewable) available in the near future, a more comprehensive approach based on the full fuel cycle, and eventually also the full life cycle of the vehicle appear to be necessary. the paper is a contribution to trigger …

Crop Updates 2011 - Weeds, Grant Thompson, Abul Hashem, Catherine Borger, Peter Newman, Mike Ashworth, Glen Riethmuller, David Minkey, Harmohinder Dhammu, David Nicholson, Michael Walsh, Ray Harrington, Nicholas Woods

Crop Updates

This session covers twelve papers from different authors:

1. Herbicides for selective spot spraying application on winter weeds in chemical fallow, Grant Thompson, Landmark/Crop Circle Consulting, Geraldton

2. Management of emerging weeds within the Western Australian wheatbelt, Abul Hashem and Catherine Borger Department of Agriculture and Food

3. Integrated Weed Management (IWM) – it’s all about early sowing of a big crop, Peter Newman, Department of Agriculture and Food

4. Increased water rates improve the performance of trifluralin in minimum tillage systems, Catherine Borger1, Mike Ashworth2, Glen Riethmuller1, David Minkey2, Abul …

Effects Of Heat Flux On Nucleate Boiling In Microgravity, Andrew Fassman

Presentations

No abstract provided.

The Design And Construction Of A Microgravity Boiling Experiment, Troy Munro

Presentations

No abstract provided.