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Articles 16231 - 16260 of 30252

Full-Text Articles in Mechanical Engineering

Use Of Direct Metal Laser Sintering For Tooling In High Volume Production, Joel W. Hendrickson May 2015

Use Of Direct Metal Laser Sintering For Tooling In High Volume Production, Joel W. Hendrickson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Metal 3D printing has caught the attention of many large industries. There have been stories of great success using metal 3D printing. Some of the largest industries to successfully use metal 3D printing are aerospace and medical. These industries have succeeded with metal 3D printing because of their need for light and complex parts. These success stories lead other industries to investigate how metal 3D printing or Direct Metal Laser Sintering (DMLS) can help them. Industries that are involved in high volume production ask how they can take advantage of the complexity and customization that is available with 3D printing. …


Proper Orthogonal Decomposition For Incompressible And Compressible Flows, Seyed Milad Rafieinaini May 2015

Proper Orthogonal Decomposition For Incompressible And Compressible Flows, Seyed Milad Rafieinaini

Theses and Dissertations - UTB/UTPA

In this project, reduced order modelling technique has been used to investigate incompressible and compressible flows. At first, Proper Orthogonal Decomposition (POD), Singular Value Decomposition (SVD) and Principal Component Analysis (PCA) have been used to analyze pulsed jet flow as an incompressible flow and supersonic impinging jet as a compressible flow. Then, two flows have been investigated from physics point of view and finally the link between physics of flows and modes have been studied. All investigations have been done based on the given data from Particle Image Velocimetry (PIV). These data have been analyzed by using MATLAB®. Finally, the …


The Design, Build, And Validation Of A Hybrid Tower Used To Conduct Helmet Impact Tests, Darren Benn May 2015

The Design, Build, And Validation Of A Hybrid Tower Used To Conduct Helmet Impact Tests, Darren Benn

UNLV Theses, Dissertations, Professional Papers, and Capstones

The National Operating Committee on Standards for Athletic Equipment (NOCSAE) was established to enlist research directed towards the reduction of head injuries in organized sports. The function of the test methods developed by NOCSAE is to provide the blueprint for reliable and repeatable procedures to measure the evaluation of various types of protective sports headgear and projectiles. In addition, the methods also govern hardware such as testing apparatus and data acquisition instrumentation. In helmet testing, the method dictates whether the impact is induced by a projectile system or by a drop tower system with an anvil at the base. Altogether, …


Bi-Stable Buckled Energy Harvesters Actuated Via Torque Arms., Daniel Allen Porter May 2015

Bi-Stable Buckled Energy Harvesters Actuated Via Torque Arms., Daniel Allen Porter

Electronic Theses and Dissertations

Vibrational energy harvesters (VEH) are one way to generate electricity. Though the energy quantities are not enough to run desktop computers, they can power remote devices such as temperature, pressure, and accelerometer sensors or power biological implants. New versions of the Bluetooth protocol can even be used with VEH technology to send wireless data. An important aspect of VEH devices is the power output, operating frequency, and bandwidth. This dissertation investigates a novel method of actuating the primary buckled energy harvesting structure using torque arms as a force amplification mechanism. Buckled structures can exhibit snap-through and has the potential to …


Vanadium Trichloride Thermochemical Solar Energy Storage System Analysis., Caleb Michael Rogers May 2015

Vanadium Trichloride Thermochemical Solar Energy Storage System Analysis., Caleb Michael Rogers

Electronic Theses and Dissertations

As annual energy consumption grows, developing renewable solar energy conversion systems, storage systems, and high density electrical energy production systems is growing increasingly important. The proposed system utilizes vanadium trichloride thermal decomposition to produce chlorine gas and vanadium dichloride. A second reaction combines gaseous hydrogen chloride and the product vanadium dichloride to reform vanadium trichloride and produce hydrogen gas. Hydrogen gas and chlorine gas can be stored indefinitely and electrical energy is obtained from the chemicals by a non-humidified dry membrane hydrogen – chlorine fuel cell. The fuel cell produces the gaseous hydrogen chloride needed to reform vanadium trichloride. The …


Supersonic Retro-Propulsion Computational Fluid Dynamics Analysis Applied To Future Mars Mission, Margarita Nataly Brandt May 2015

Supersonic Retro-Propulsion Computational Fluid Dynamics Analysis Applied To Future Mars Mission, Margarita Nataly Brandt

Doctoral Dissertations and Master's Theses

Supersonic Retro-Propulsion is one of the most promising emerging technologies being considered by NASA for use in future Mars missions. This new form of Entry Descent Landing has the potential to help increase the allowable payload mass currently constraining many science instruments and operations. Computational Fluid Dynamics was used to show the feasibility of supersonic retro - propulsion in Mars atmospheric conditions. The results presented show the SRP will be able to perform satisfactory using the same conditions that the Curiosity Rover was exposed to during its landing sequence. The plume expansion was analyzed for various cases, moving from free …


Electrokinetic Flow In A Nanochannel With An Overlapped Electrical Double Layer, Zhuorui Song May 2015

Electrokinetic Flow In A Nanochannel With An Overlapped Electrical Double Layer, Zhuorui Song

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research is a theoretical study aiming to improve the understanding of nanofluidic flows. Nanofluidic flows have a wide range of potential application in many fields, such as DNA analysis, drug delivery, analyte separation, power generation, and so on. The most common material used in nanofluidic flows is silica whose surfaces are charged mainly due to proton exchange with the fluids. Charges on the surfaces as well as near the surfaces in the fluid side cause a significantly different response of the fluids to the applied electric field or pressure difference compared to those at normal scale. In the previous …


Mechanical Properties Of Kenaf Composites Using Dynamic Mechanical Analysis, Thomas A. Loveless May 2015

Mechanical Properties Of Kenaf Composites Using Dynamic Mechanical Analysis, Thomas A. Loveless

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Natural fibers show potential to replace glass fibers in thermoset and thermoplastic composites. Kenaf is a bast-type fiber with high specific strength and great potential to compete with glass fibers.

In this research kenaf/epoxy composites were analyzed using Dynamic Mechanical Analysis (DMA). A three-point bend apparatus was used in the DMA testing. The samples were tested at 1 hertz, at a displacement of 10 μm, and at room temperature.

The fiber volume content of the kenaf was varied from 20%-40% in 5% increments. Ten samples of each fiber volume fraction were manufactured and tested. The flexural storage modulus, the flexural …


Techno-Economic Feasibility And Life Cycle Assessment Of Dairy Effluent To Biofuel Via Hydrothermal Liquefaction, Hailey M. Summers May 2015

Techno-Economic Feasibility And Life Cycle Assessment Of Dairy Effluent To Biofuel Via Hydrothermal Liquefaction, Hailey M. Summers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Delactosed whey permeate (delac) is a low valued by-product in the dairy industry with 90 million tons annually disposed of worldwide. Upgrading delac to bioproducts, specifically biofuel, has been demonstrated at laboratory scale through yeast fermentation. However, the large-scale environmental impact and economic feasibility of this process is yet to be quantified. Further research, focused on evaluating the sustainability, scalability and economic feasibility of the fermentation pathway, directs research and development to move the technology towards commercialization. The enclosed research incorporates biological experimentation with engineering systems modeling to evaluate the large-scale environmental impacts and economic feasibility of generating bioproducts from …


Methods Of Processing Kenaf Chopped Strand Mats For Manufacturing Test Specimens And Composite Structures, Joshua W. Heil May 2015

Methods Of Processing Kenaf Chopped Strand Mats For Manufacturing Test Specimens And Composite Structures, Joshua W. Heil

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Every year in the United States, 10 to 11 million vehicles reach the end of their life cycle. Nearly all of these go to a recycling facility. After the recycling process is complete an average of 25% of each vehicle, by weight, goes to waste. This demonstrates the need to use natural fibers in parts that could be recycled, like parts that can be made from kenaf. There are many reasons to consider using natural/bio-fiber composites (bio-composites). These reasons include human health and environmental factors as well as advantages that natural fibers have over fiberglass, such as: lower costs and …


Effective Properties Of Randomly Oriented Kenaf Short Fiber Reinforced Epoxy Composite, Dayakar Naik L. May 2015

Effective Properties Of Randomly Oriented Kenaf Short Fiber Reinforced Epoxy Composite, Dayakar Naik L.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Natural fibers have drawn attention of researchers as an environmentally-friendly alternative to synthetic fibers. Developing natural fiber reinforced bio-composites are a viable alternative to the problems of non-degrading and energy consuming synthetic composites. This study focuses on (i) the application of kenaf fiber as a potential reinforcement and, (ii) determining the tensile properties of the randomly oriented short kenaf fiber composite both experimentally and numerically. Kenaf fiber micro-structure and its Young's modulus with varying gage length (10, 15, 20, and 25.4 mm) were investigated. The variation in tensile strength of kenaf fibers was analyzed using the Weibull probability distribution function. …


Extensions Of High-Order Flux Correction Methods To Flows With Source Terms At Low Speeds, Jonathan L. Thorne May 2015

Extensions Of High-Order Flux Correction Methods To Flows With Source Terms At Low Speeds, Jonathan L. Thorne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Computational Fluid Dynamics (CFD) is an attempt to mimic the physical world of fluids around us. In general, CFD simulations are completed by first making a mesh. Meshes are made of polygons that are arranged in such a way as to create the item in question and the fluid around it. There are many difficulties associated with mesh generation, and it can take days or weeks for a trained professional to produce adequate meshes. The CFD algorithms affect the accuracy of the simulation. Using high-order methods, more accurate results can be achieved than otherwise possible. Flux correction (FC) is a …


Parameterized Least-Squares Attitude History Estimation And Magnetic Field Observations Of The Auroral Spatial Structures Probe, Ryan J. Martineau May 2015

Parameterized Least-Squares Attitude History Estimation And Magnetic Field Observations Of The Auroral Spatial Structures Probe, Ryan J. Martineau

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As charged particles from the Sun enter the Earth’s atmosphere and create the aurora borealis (Northern lights) and aurora australis (Southern lights), energy is transferred to the atmosphere. In order to better understand the energy transfer processes, the Auroral Spatial Structures Probe rocket was launched to make measurements in the active aurora. Several payloads were deployed by the rocket, each with sensors to measure the magnetic field and the electric field so that the way they change over time and in different positions could be observed. The measurements require accurate knowledge of the spacecraft orientation, and to that end this …


Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photo Catalytic Applications, Haya Abdel Ra’Ouf Ahmed Ra’Ouf Ahmed May 2015

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photo Catalytic Applications, Haya Abdel Ra’Ouf Ahmed Ra’Ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO2 nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO2 nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO2 nanomaterials. In this work, we have prepared Cu-doped TiO2 and Ag-doped TiO2 nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO2 catalyst was prepared by the sol-gel method while the Cu-doped …


Effect Of Manufacturing Processes On The Loss Factor And Other Mechanical Properties Of Kenaf Fiber-Reinforced Composites, Brian P. Spackman May 2015

Effect Of Manufacturing Processes On The Loss Factor And Other Mechanical Properties Of Kenaf Fiber-Reinforced Composites, Brian P. Spackman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The characteristics essential for manufacturing parts and products are not well known for natural fiber-reinforced composite materials. Natural fibers display properties similar to glass fibers, and present a more environmentally friendly option for manufacturing composite materials. This research investigates various parameters in the manufacture of kenaf fiber-reinforced composites including cure time, density, matrix hardener ratio, surface treatment, and fiber length and examines the effect they have on mechanical properties of the composite material. Several samples were created and subjected to a vibrational test. Using known relationships, mechanical properties were extracted from the test results. Samples were found to exhibit repeatable …


Experimental Validation Data For Cfd Of Steady And Transient Mixed Convection On A Vertical Flat Plate, Blake W. Lance May 2015

Experimental Validation Data For Cfd Of Steady And Transient Mixed Convection On A Vertical Flat Plate, Blake W. Lance

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this computer age, simulations are becoming common in science and engineering. One category of simulation, Computational Fluid Dynamics (CFD), begins with physical equations but adds approximations and calibrations in order to complete solutions. Translating these equations into computer languages may cause unintended errors. If simulation results are to be used for decision making, their accuracy needs to be assessed. This accuracy assessment is the theory behind the field of Verification & Validation.

Verification involves confirming the translation of physical equations to computer language was per- formed correctly. It also features methods to detect many types of code errors. Validation …


An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert Apr 2015

An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Here we share a rich gait data set collected from fifteen subjects walking at three speeds on an instrumented treadmill. Each trial consists of 120 s of normal walking and 480 s of walking while being longitudinally perturbed during each stance phase with pseudo-random fluctuations in the speed of the treadmill belt. A total of approximately 1.5 h of normal walking (>5000 gait cycles) and 6 h of perturbed walking (>20,000 gait cycles) is included in the data set. We provide full body marker trajectories and ground reaction loads in addition to a presentation of processed data that …


Collapsible Bicycle Frame, Keith Stone Apr 2015

Collapsible Bicycle Frame, Keith Stone

Mechanical Engineering and Technology Senior Projects

There are many situations where people could choose to ride a bicycle, whether it is to go to school, to a job, to meet with friends, or just for recreational purposes. However, once people reach their destination and have a break between their trips, they are left with a bicycle with little means of storing it while they go about their day. Some people buy a bike lock so that they can secure it in a safe location, while others may just lean it against a wall or even roll it into the building with them. However, according to FBI …


Design And Implementation Of An Interactive Animatronic System For Guest Response Analysis, Brian Burns Apr 2015

Design And Implementation Of An Interactive Animatronic System For Guest Response Analysis, Brian Burns

GS4 Student Scholars Symposium

For nearly half a century, animatronic figures have provided entertainment in the theme park industry by simulating life-like animations and sounds. These figures enhance the storytelling experience by stimulating visual and audio senses among guests. Animatronics must be identified as human partners to establish status for dynamic interactions for enhanced acceptance and effectiveness as socially-interactive agents. An animatronic dragon, Kronos, has been designed, fabricated and implemented with human-identification sensors. The primary sensor input comes from an infrared camera, the PrimeSense Carmine, and includes an Arduino Mega 2560 as the center of control. Using the data from the depth camera, people …


Simulation Of Complex Ionic Liquid Ionization Process, Forrest Grady Kidd Iii Apr 2015

Simulation Of Complex Ionic Liquid Ionization Process, Forrest Grady Kidd Iii

Research and Creative Activities Poster Day

The future of satellites will require dual-mode propulsion to obtain dynamic orbits. One set of propellants capable of dual-mode propulsion are ionic liquids. These energy-dense liquids have similar thrust characteristics to SOTA monopropellants and low vapor pressures making them safer to handle. That low vapor pressure makes ionization more difficult as it requires the propellant to be in a gaseous state. This requires experiments to determine how to efficently vaporize and ionize this propellant. Computational modelling is needed to guide these experiments and to develop simulations that can extrapolate the data to more complex geometries.


Conceptual Development Of An Impact-Attenuation System For Intersecting Roadways, Joseph G. Putjenter Apr 2015

Conceptual Development Of An Impact-Attenuation System For Intersecting Roadways, Joseph G. Putjenter

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Longitudinal barriers are commonly used to shield hazards, including stiff bridge rail ends and slopes. In some locations, a secondary roadway intersects the primary roadway within the guardrail’s length-of-need (LON). Some intersections have as little as 15 ft (4.6 m) between the intersection and beginning of the bridge railing, which require short-radius guardrail systems. No short-radius systems have been tested and approved to current impact safety standards for shielding hazards with these conditions.

Site conditions provided by the Nebraska Department of Roads were used to determine the constraints for a new safety treatment for intersecting roadways and include intersection radii, …


Local Control Robotic Surgical Devices And Related Methods, Eric Markvicka, Tom Frederick, Jack Mondry, Joe Bartels, Shane Farritor Apr 2015

Local Control Robotic Surgical Devices And Related Methods, Eric Markvicka, Tom Frederick, Jack Mondry, Joe Bartels, Shane Farritor

Department of Mechanical and Materials Engineering: Faculty Publications

The various robotic medical devices include robotic devices that are disposed within a body cavity and positioned using a support component disposed through an orifice or opening in the body cavity. Additional embodiments relate to devices having arms coupled to a device body wherein the device has a minimal profile such that the device can be easily inserted through smaller incisions in comparison to other devices without such a small profile. Further embodiments relate to methods of operating the above devices.


Investigation Of Synthesis And Processing Of Cellulose, Cellulose Acetate And Poly(Ethylene Oxide) Nanofibers Incorporating Anti-Cancer/Tumor Drug Cis-Diammineplatinum (Ii) Dichloride Using Electrospinning Techniques, Saheem Absar, Mujibur R. Khan, Kyle Edwards, Jeffrey Neumann Apr 2015

Investigation Of Synthesis And Processing Of Cellulose, Cellulose Acetate And Poly(Ethylene Oxide) Nanofibers Incorporating Anti-Cancer/Tumor Drug Cis-Diammineplatinum (Ii) Dichloride Using Electrospinning Techniques, Saheem Absar, Mujibur R. Khan, Kyle Edwards, Jeffrey Neumann

Mechanical Engineering: Faculty Publications

A model anti-cancer/tumor drug cis-diammineplatinum (II) dichloride (cisplatin) was loaded into micro- and nanofibers of cellulose, cellulose acetate (CA) and poly(ethylene oxide) (PEO), using various electrospinning techniques. Single-nozzle electrospinning was used to fabricate neat fibers of each category. Drug loading in cellulose fibers was performed using single-nozzle electrospinning. Encapsulation of cisplatin in CA and PEO-based fibers was performed using coaxial electrospinning. Morphological analysis of the fibers was performed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The various categories of fibers exhibited diverse morphological features depending on the material compositions and applied process parameters. The drug-loaded cellulose …


Mechanical Engineering News, Georgia Southern University Apr 2015

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

  • Eagle Motorspots Places 5th Overall at Auburn


A Study Of Microwave Curing Of Underfill Using Open And Closed Microwave Ovens, Aditya Thakare Apr 2015

A Study Of Microwave Curing Of Underfill Using Open And Closed Microwave Ovens, Aditya Thakare

Dissertations and Theses

As the demand for microprocessors is increasing with more and more consumers using integrated circuits in their daily life, the demand on the industry is increasing to ramp up production.

In order to speed up the manufacturing processes, new and novel approaches are trying to change certain aspects of it. Microwaves have been tried as an alternative to conventional ovens in the curing of the polymers used as underfills and encapsulants in integrated circuits packages. Microwaves however being electromagnetic waves have non uniform energy distribution in different settings, causing burning or incomplete cure of polymers.

In this study, we compare …


Semi-Annual Program Progress Performance Report For The Electric Vehicle Transportation Center Pppr#3, Florida Solar Energy Center, David L. Block Apr 2015

Semi-Annual Program Progress Performance Report For The Electric Vehicle Transportation Center Pppr#3, Florida Solar Energy Center, David L. Block

FSEC Energy Research Center®

This document covers the program activities of the University of Central Florida's Electric Vehicle Transportation Center (EVTC) for the 6 month period of October 1, 2014 to March 31, 2015. The Electric Vehicle Transportation Center supports the U.S. Department of Transportation's strategic goal of planning for near-term integration of alternative fuel vehicles as a means to build a sustainable transportation system. The project objectives are to evaluate technologies, standards and policies to ensure seamless integration of electric vehicles (EVs) into a complex transportation network and electricity grid. The EVTC will bridge the gap between deployment of electric vehicles and the …


The Research, Design And Implementation Of A Remotely Operated Bioreactor With Incubation System For The Purpose Of A 3d Cell Line Growth, Steven Doyle, John Helms, Ryan Longchamps Apr 2015

The Research, Design And Implementation Of A Remotely Operated Bioreactor With Incubation System For The Purpose Of A 3d Cell Line Growth, Steven Doyle, John Helms, Ryan Longchamps

Research Horizons Day Posters

No abstract provided.


Sailboat Disablement Project- Net Entanglement System, Christine Milton Apr 2015

Sailboat Disablement Project- Net Entanglement System, Christine Milton

Research Horizons Day Posters

No abstract provided.


Distributed Wireless Pzt Fiber Composite Sensor System Development And Demonstration, Ethan Hopping, Markus Murdy Apr 2015

Distributed Wireless Pzt Fiber Composite Sensor System Development And Demonstration, Ethan Hopping, Markus Murdy

Research Horizons Day Posters

No abstract provided.


Slip Length Crossover On A Graphene Surface, Zhi Liang, Pawel Keblinski Apr 2015

Slip Length Crossover On A Graphene Surface, Zhi Liang, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using Equilibrium and Non-Equilibrium Molecular Dynamics Simulations, We Study the Flow of Argon Fluid above the Critical Temperature in a Planar Nanochannel Delimited by Graphene Walls. We Observe that, as a Function of Pressure, the Slip Length First Decreases Due to the Decreasing Mean Free Path of Gas Molecules, Reaches the Minimum Value When the Pressure is Close to the Critical Pressure, and Then Increases with Further Increase in Pressure. We Demonstrate that the Slip Length Increase at High Pressures is Due to the Fact that the Viscosity of Fluid Increases Much Faster with Pressure Than the Friction Coefficient between …