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2014

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Articles 1 - 30 of 1205

Full-Text Articles in Mechanical Engineering

Design And Development Of The Portable Build Platform And Heated Travel Envelope For The Multi3d Manufacturing System, Steven Daniel Ambriz Dec 2014

Design And Development Of The Portable Build Platform And Heated Travel Envelope For The Multi3d Manufacturing System, Steven Daniel Ambriz

Open Access Theses & Dissertations

The final product functionality of parts produced by Additive Manufacturing (AM) can, in part, be improved by the inclusion of multi-material capabilities. The “Multi3D system” that is under development at The University of Texas at El Paso uses material extrusion printing (or fused deposition modeling), solid conductor wire embedding, direct-write, component placement, and micromaching to enable multi-material fabrication. The Multi3D was designed to transport a workpiece between manufacturing stations via a six-axis robot, portable build platform (PBP), and a controlled temperature environment or chamber that travels to each manufacturing station. The heated travel envelope (HTE) was included to mitigate thermal ...


Cruise Ship Preliminary Design: The Influence Of Design Features On Profitability, Justin Epstein Dec 2014

Cruise Ship Preliminary Design: The Influence Of Design Features On Profitability, Justin Epstein

University of New Orleans Theses and Dissertations

This thesis provides a means to estimate the physical and performance characteristics of a preliminary cruise ship design. The techniques utilized to estimate these characteristics are showcased in the user-friendly interface known as the Cruise Ship Analysis Tool (CSAT). Using the CSAT, the implications that design feature decisions in the preliminary design stage have on a cruise ship’s profitability is analyzed. Then, the most profitable design feature assemblage among a finite number of varying design feature combinations is estimated and compared among cruise ship designs with different passenger carrying capacities. Profitability is analyzed using the measure of merit (MOM ...


Modal Characterization And Structural Dynamic Response Of A Crane Fly Forewing, Jose E. Rubio Dec 2014

Modal Characterization And Structural Dynamic Response Of A Crane Fly Forewing, Jose E. Rubio

University of New Orleans Theses and Dissertations

This study describes a method for conducting the structural dynamic analysis of a crane fly (family Tipulidae) forewing under different airflow conditions. Wing geometry is captured via micro-computed tomography scanning. A finite element model of the forewing is developed from the reconstructed model of the scan. The finite element model is validated by comparing the natural frequencies of an elliptical membrane with similar dimensions of the crane fly forewing to its analytical solution. Furthermore, a simulation of the fluid-structure interaction of the forewing under different airflows is performed by coupling the finite element model of the wing with a computation ...


Investigation Of The Quenching Characteristics Of Steel Components By Static And Dynamic Analyses, Pratik Sarker Dec 2014

Investigation Of The Quenching Characteristics Of Steel Components By Static And Dynamic Analyses, Pratik Sarker

University of New Orleans Theses and Dissertations

Machine components made of steel are subjected to heat treatment processes for improving mechanical properties in order to enhance product life and is usually done by quenching. During quenching, heat is transferred rapidly from the hot metal component to the quenchant and that rapid temperature drop induces phase transformation in the metal component. As a result, quenching generates some residual stresses and deformations in the material. Therefore, to estimate the temperature distribution, residual stress, and deformation computationally; three-dimensional finite element models are developed for two different steel components – a spur gear and a circular tube by a static and a ...


A Reversible And Stable Flake-Like Licoo2 Cathode For Lithium Ion Batteries, Tao Wei, Rui Zeng, Yongming Sun, Yunhui Huang, Kevin Huang Dec 2014

A Reversible And Stable Flake-Like Licoo2 Cathode For Lithium Ion Batteries, Tao Wei, Rui Zeng, Yongming Sun, Yunhui Huang, Kevin Huang

Faculty Publications

A dense and thick flake-like cathode structure was demonstrated to have a preferential crystallographic orientation for Li+ migration and a better tolerance to cracking, both of which enable a reversible and stable capacity at moderate rates from 0.1 to 2 C.


Wind And Thermal Effects On Ground Mounted Photovoltaic (Pv) Panels, Chowdhury Mohammad Jubayer Dec 2014

Wind And Thermal Effects On Ground Mounted Photovoltaic (Pv) Panels, Chowdhury Mohammad Jubayer

Electronic Thesis and Dissertation Repository

A combination of Computational Fluid Dynamics (CFD) simulations and wind tunnel experiments are carried out to investigate the effects of wind on the aerodynamic loading and heat transfer of a ground mounted stand-alone photovoltaic (PV) panel with tilt angle of 25o in open country atmospheric boundary layer. Several azimuthal wind directions are considered: Southern 0o, Southwest 45o, Northwest 135o and Northern 180o. Three dimensional Reynolds-Averaged Navier-Stokes (RANS) approaches with an unsteady solver using Shear Stress Transport (SST) k-ω turbulence closure are employed for the CFD simulations, whereas Particle Image Velocimetry (PIV) and Hot Wire Anemometry ...


Snowboard, Ski, And Skateboard Sensor System Application, Adrien Doiron, Michael Fernandez, Victor Ojeda, Robert Ross Dec 2014

Snowboard, Ski, And Skateboard Sensor System Application, Adrien Doiron, Michael Fernandez, Victor Ojeda, Robert Ross

Mechanical Engineering Senior Theses

The goal of this project was develop a sensor for the commercial market for skiers, snowboarders, and skateboarders that can give them the data such as speed, elevation, pressure, temperature, flex, acceleration, position, and other performance data such as trick characterization. This was done by using a variety of sensors, including a GPS, flex sensors, accelerometer, and others to provide data such as speed, position, position, and temperature. The sensors were placed in an external polycarbonate casing attached to the ski or board by using an adhesive pad on the bottom of the casing. These sensors then transmit the data ...


Behavior Of Piezoelectric Wafer Active Sensor In Various Media, Tuncay Kamas Dec 2014

Behavior Of Piezoelectric Wafer Active Sensor In Various Media, Tuncay Kamas

Theses and Dissertations

The dissertation addresses structural health monitoring (SHM) techniques using ultrasonic waves generated by piezoelectric wafer active sensors (PWAS) with an emphasis on the development of theoretical models of standing harmonic waves and guided waves. The focal objective of the research is to extend the theoretical study of electro-mechanical coupled PWAS as a resonator/transducer that interacts with standing and traveling waves in various media through electro-mechanical impedance spectroscopy (EMIS) method and guided wave propagation. The analytical models are developed and the coupled field finite element analysis (CF-FEA) models are simulated and verified with experiments. The dissertation is divided into two ...


Low Reynolds Number Turbulence: Mechanisms And Applications, Wei Zhao Dec 2014

Low Reynolds Number Turbulence: Mechanisms And Applications, Wei Zhao

Theses and Dissertations

Turbulence, as one of "the most important unsolved classical problem in physics" (R. Feynman, 1932), has been investigated for more than 130 years. Conventionally, turbulence is believed to be a phenomenon of high Reynolds numbers (Re). However, we find that turbulence can also be achieved at low Re by proper external forcing, either in macroflows or in microflows. In macroflows, the characteristics of high Re turbulence can be achieved in confined flows, when the bulk flow Re is around 400, by external forcing at its optimal frequency (Wang 2003; Wang 2006). Interestingly, the optimal narrow band of frequency is fixed ...


Cost Avoidance Analysis Of Military Aircraft Components Utilizing Condition-Based Maintenance Practices, Erin Ballentine Dec 2014

Cost Avoidance Analysis Of Military Aircraft Components Utilizing Condition-Based Maintenance Practices, Erin Ballentine

Theses and Dissertations

This research involves two major case studies. Both look at the current maintenance practices done by the United States Army and propose a solution for improvement utilizing condition-based maintenance (CBM) practices. Each study details a cost avoidance that can be earned by implementing the solutions and the resulting benefits that can be experienced. Case Study I is a return on investment (ROI) that analyzes the benefits of the implementation of elastomeric wedges as vibration control on the Apache (AH-64D) aircraft. Analysis of the material and operational costs shows that the use of self-adhering elastomeric trailing edge wedges on the Apache ...


On The Development Of High Strain Rate Experiments For The Characterization Of Engineering Materials, Silas P. Mallon Dec 2014

On The Development Of High Strain Rate Experiments For The Characterization Of Engineering Materials, Silas P. Mallon

Theses and Dissertations

In order to predict the damage accumulation and failure processes associated with highly dynamic events such as blast loading, shock wave loading, and ballistic impact loading, a commensurate understanding of the fundamental constitutive and fracture behavior of materials subjected to such high rate loading conditions is necessary. In this effort, high strain rate experimental facilities consisting of a shock tube apparatus and a torsional split Hopkinson bar apparatus have been designed, constructed, and subsequently used to investigate the mechanical properties of an array of engineering materials subjected to a variety of dynamic loading conditions. Designs for the experimental equipment utilized ...


Fabrication And Characterization Of Novel Electrodes For Solid Oxide Fuel Cell For Efficient Energy Conversion, Yu Chen Dec 2014

Fabrication And Characterization Of Novel Electrodes For Solid Oxide Fuel Cell For Efficient Energy Conversion, Yu Chen

Theses and Dissertations

Solid oxide fuel cells (SOFCs) have been considered as one of the most promising technologies for future energy conversion since they can in principle be operated with fuels ranging from H2 to any hydrocarbon fuel. However, the system cost and coking (when using hydrocarbon as fuel) issues for the state-of-art electrode materials/designs often limit their further application. The objective of this Ph.D dissertation is aiming at overcoming these problems and accelerating SOFC commercialization. One approach to cost reduction is lowering the SOFC operating temperature to below 800 or even 600 oC, so that inexpensive materials can be used ...


Applications Of Advanced Imaging Methods: Macro-Scale Studies Of Woven Composites And Micro-Scale Measurements On Heated Ic Packages, Siming Guo Dec 2014

Applications Of Advanced Imaging Methods: Macro-Scale Studies Of Woven Composites And Micro-Scale Measurements On Heated Ic Packages, Siming Guo

Theses and Dissertations

As a representative advanced imaging technique, the digital image correlation (DIC) method has been well established and widely used for deformation measurements in experimental mechanics. This methodology, both 2D and 3D, provides qualitative and quantitative information regarding the specimen’s non-uniform deformation response. Its full-field capabilities and non-contacting approach are especially advantageous when applied to heterogeneous material systems such as fiber-reinforced composites and integrated chip (IC) packages. To increase understanding of damage evolution in advanced composite material systems, a series of large deflection bending-compression experiments and model predictions have been performed for a woven glass-epoxy composite material system. Stereo digital ...


Developing A Wireless Sensor Network Programming Language Application Guide Using Memsic Devices And Labview, Xiao Xie Dec 2014

Developing A Wireless Sensor Network Programming Language Application Guide Using Memsic Devices And Labview, Xiao Xie

Master of Technology Management Plan II Graduate Projects

The principal objective of this project is to develop a wireless sensor network (WSN) programming language application guide for junior and senior undergraduate students in College of Technology, Architecture and Applied Engineering in Bowling Green State University. Memsic device, MoteWorks and LabVIEW software are used to conduct experiments in developing WSN applications after both software and hardware platform are verified to be usable with experimental and statistical analysis. The guide is divided into six chapters including both theoretical knowledge and practical experiments in WSN area. Programs, both in nesC language and LabVIEW are improved from previous work, tested to run ...


Multiple Pure Tone Noise Prediction, Fei Han, Anupam Sharma, Umesh Paliath, Chingwei Shieh Dec 2014

Multiple Pure Tone Noise Prediction, Fei Han, Anupam Sharma, Umesh Paliath, Chingwei Shieh

Aerospace Engineering Publications

This paper presents a fully numerical method for predicting multiple pure tones, also known as “Buzzsaw” noise. It consists of three steps that account for noise source generation, nonlinear acoustic propagation with hard as well as lined walls inside the nacelle, and linear acoustic propagation outside the engine. Noise generation is modeled by steady, part-annulus computational fluid dynamics (CFD) simulations. A linear superposition algorithm is used to construct full-annulus shock/pressure pattern just upstream of the fan from part-annulus CFD results. Nonlinear wave propagation is carried out inside the duct using a pseudo-two-dimensional solution of Burgers׳ equation. Scattering from nacelle ...


On The Application Of Mechanical Vibration In Robotics-Assisted Soft Tissue Intervention, Iman Khalaji Dec 2014

On The Application Of Mechanical Vibration In Robotics-Assisted Soft Tissue Intervention, Iman Khalaji

Electronic Thesis and Dissertation Repository

Mechanical vibration as a way of transmitting energy has been an interesting subject to study. While cyclic oscillation is usually associated with fatigue effect, and hence a detrimental factor in failure of structures and machineries, by controlled transmission of vibration, energy can be transferred from the source to the target. In this thesis, the application of such mechanical vibration in a few surgical procedures is demonstrated.

Three challenges associated with lung cancer diagnosis and treatment are chosen for this purpose, namely, Motion Compensation, tumor targeting in lung Needle Insertion and Soft Tissue Dissection:

  1. A robotic solution is proposed for compensating ...


Toy Train Group Ii, Track Laying Train, William Andersen, Jordan Zwetchkenbaum, Chiamaka Asinugo Dec 2014

Toy Train Group Ii, Track Laying Train, William Andersen, Jordan Zwetchkenbaum, Chiamaka Asinugo

Mechanical Engineering Design Project Class

No abstract provided.


A Microstructural Constitutive Framework For Injured Ligament, Christina J. Stender, Evan Rust, Raquel J. Brown, Trevor J. Lujan Dec 2014

A Microstructural Constitutive Framework For Injured Ligament, Christina J. Stender, Evan Rust, Raquel J. Brown, Trevor J. Lujan

Biomolecular Research Center Student Presentations

No abstract provided.


Evaluation Of The Mass Transfer Effect Of The Stalk Contraction-Relaxation Cycle Of Vorticella Convallaria, Jiazhong Zhou Dec 2014

Evaluation Of The Mass Transfer Effect Of The Stalk Contraction-Relaxation Cycle Of Vorticella Convallaria, Jiazhong Zhou

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Vorticella convallaria is a genus of protozoa living in fresh water. It has a bell-shaped zooid equipped with adoral ciliary bands and a contractile stalk tethering the zooid to a substrate. Vorticella is regarded as a biological spring because its contractile stalk can pull the zooid towards the substrate at a remarkably high speed and then relaxes to its extended state much more slowly. However, reasons for Vorticella’s stalk contraction are still unknown. It is presumed that the flow field induced by the contraction-relaxation cycle of Vorticella would augment mass transfer effect near the substrate. We investigated this hypothesis ...


Mems 411 Rc Glider 2.0 Senior Design Project, Armando Gallegos, Sayan Patra, Reggie S. Clark, Diego Alarcon Dec 2014

Mems 411 Rc Glider 2.0 Senior Design Project, Armando Gallegos, Sayan Patra, Reggie S. Clark, Diego Alarcon

Mechanical Engineering Design Project Class

Design a radio controlled scale model glider with a true "morphing" wing.


Mems 411 Senior Design: Wind Powered Walking Robot, Timothy J. Elliott, Kenna Middleton, Jose Rodes Dec 2014

Mems 411 Senior Design: Wind Powered Walking Robot, Timothy J. Elliott, Kenna Middleton, Jose Rodes

Mechanical Engineering Design Project Class

Build a ‘Machine That Walks’ using leg like linkages that is only powered by wind. It must walk a minimum of 4 meters to prove that it is capable of walking and at least half of the materials used must be recyclable or reusable within the greater St. Louis area. The machine must not exceed 10 kg and must fit in the volume of 30 cm x 60 cm x 40 cm and must be unable to be easily knocked over.


Team Sunflower - Solar Tracker Team 2, Lindsey Warden, Laura Scott, Ethan Glassman, Max Kapczynski Dec 2014

Team Sunflower - Solar Tracker Team 2, Lindsey Warden, Laura Scott, Ethan Glassman, Max Kapczynski

Mechanical Engineering Design Project Class

Our design problem was to create a solar radiation tracking device. The primary goal of this device was to keep a solar panel perpendicular to the solar radiation with 95% efficiency throughout the day. The tracker had to be able to account for the sun’s seasonal angle in St. Louis, and the design would be even better if it could account for the sun’s seasonal angle at any latitude. Another important aspect of the solar tracker design was that it must be able to reset itself each day for the sunrise without human input. Other aspects to consider ...


Toy Train Group 1, Peter A. Szostak, Chris Levin, Chris Haeberle Dec 2014

Toy Train Group 1, Peter A. Szostak, Chris Levin, Chris Haeberle

Mechanical Engineering Design Project Class

Create a toy train that lays its own tracks.


Process Simulation Of Biomass Gasification Integrated With A Solid Oxide Fuel Cell Stack, Wayne Doherty, Anthony Reynolds, David Kennedy Dec 2014

Process Simulation Of Biomass Gasification Integrated With A Solid Oxide Fuel Cell Stack, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

Biomass gasification-solid oxide fuel cell (BG-SOFC) combined heat and power (CHP) systems are of major interest in the context of climate change mitigation, energy security and increasing energy efficiency. Aspen Plus is employed to simulate various BG-SOFC CHP systems. The aim of the research work is to investigate the technical feasibility of these systems and to study the influence of important operating parameters and examine integration options. Systems based on dual fluidised bed steam gasification and tubular SOFC technologies are modelled. The cathode recycle and electric heater integration options are not attractive in comparison to the base case anode recycle ...


Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei Dec 2014

Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei

Electronic Thesis and Dissertation Repository

This thesis reports on the design, construction, and evaluation of a prototype two degrees-of-freedom (DOF) haptic interface, which takes advantage of Magneto-Rheological Fluid (MRF) based clutches for actuation. Haptic information provides important cues in teleoperated systems and enables the user to feel the interaction with a remote or virtual environment during teleoperation. The two main objectives in designing a haptic interface are stability and transparency. Indeed, deficiencies in these factors in haptics-enabled telerobotic systems has the introduction of haptics in medical environments where safety and reliability are prime considerations. An actuator with poor dynamics, high inertia, large size, and heavy ...


Control Of Responses Of Smart Plate Structures Under Non-Stationary Random Excitations, Xiaojian Yang Dec 2014

Control Of Responses Of Smart Plate Structures Under Non-Stationary Random Excitations, Xiaojian Yang

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

This thesis is concerned with an investigation of the control of responses of plate structures with piezoelectric layers and under complicated excitations modeled as a non-stationary random process. The plate structures and piezoelectric layers are both discretized by the mixed formulation finite element method (FEM).

The investigation consists of three parts. The first part is a literature survey and theoretical development. The second part is the eigenvalue solution and computation of uncontrolled response statistics of laminated plate structures under nonstationary random excitations. The final part is the introduction and application of the stochastic central difference (SCD) method that was presented ...


Heat Transfer Enhancement And Applications Of Femtosecond Laser Processed Metallic Surfaces, Corey M. Kruse Dec 2014

Heat Transfer Enhancement And Applications Of Femtosecond Laser Processed Metallic Surfaces, Corey M. Kruse

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

In the present work, functionalized 304 stainless steel metallic surfaces were created with the use of a Femtosecond Laser Surface Processing (FLSP) technique. The laser processing technique produces self-organized micro/nanostructures on the surface. The heat transfer performance of various FLSP functionalized surfaces were characterized through pool boiling and Leidenfrost experiments. Enhancement in both the nucleate and film boiling heat transfer were observed through an increase of the critical heat flux and heat transfer coefficient as well as shifts in the Leidenfrost temperature respectively. For both experiments, a polished reference sample was used as a baseline line to compare against ...


Numerical Modeling Of Deformation, Oscillation, Spreading And Collision Characteristics Of Droplets In An Electric Field, Osameh Ghazian Dec 2014

Numerical Modeling Of Deformation, Oscillation, Spreading And Collision Characteristics Of Droplets In An Electric Field, Osameh Ghazian

Electronic Thesis and Dissertation Repository

Electric field induced flows, or electrohydrodynamics (EHD), have been promising in many fast-growing technologies, where droplet movement and deformation can be controlled to enhance heat transfer and mass transport. Several complex EHD problems existing in many applications were investigated in this thesis.

Firstly, this thesis presents the results of numerical simulations of the deformation, oscillation and breakup of a weakly conducting droplet suspended in an ambient medium with higher conductivity. It is the first time that the deformation of such a droplet was investigated numerically in a 3D configuration. We have determined three types of behavior for the droplets, which ...


Carbon Dioxide Photoreduction With Water Vapor By Titanium-Containing Magnesium-Aluminum Layered Double Hydroxides, Jinye Xu Dec 2014

Carbon Dioxide Photoreduction With Water Vapor By Titanium-Containing Magnesium-Aluminum Layered Double Hydroxides, Jinye Xu

Theses and Dissertations

Photocatalytic conversion of CO2 into value-added solar fuels is a promising approach to simultaneously address the greenhouse gas pollution and energy shortage issues. TiO2, the most widely studied photocatalyst, suffers from drawbacks like fast electron-hole recombination and limited CO2 adsorption. In this study, Ti-containing MgAl layered double hydroxides (MgAl/Ti-LDHs) were designed to provide high activity of CO2 photoreduction by dispersing Ti species over MgAl-LDHs which have been extensively investigated as CO2 adsorbent. This study was the first attempt to apply MgAl/Ti-LDHs for photoreduction of CO2 with water vapor.

MgAl/Ti-LDHs were prepared through coprecipitation (CP) method, the most ...


Mems Based Microneedle Actuator With Piezoresistive Force Feedback System For Biomedical Applications, Innovative Research Publications Irp India, Ashen Wijesiri, Y.W.R. Amarasinghe Dec 2014

Mems Based Microneedle Actuator With Piezoresistive Force Feedback System For Biomedical Applications, Innovative Research Publications Irp India, Ashen Wijesiri, Y.W.R. Amarasinghe

Innovative Research Publications IRP India

This paper presents a novel design of MEMS based microneedle actuator with force feedback system which can be used for biomedical applications such as cell manipulation, drug delivery and DNA injection. The actuation mechanism of microneedle is driven by two electrostatic comb actuators. Since the manipulated objects are very sensitive, and can be easily damaged, it’s essential to have a force feedback system in the micro actuator to avoid unnecessary deformations. Piezoresistive sensing elements are used for the force feedback of the system. The proposed system was simulated using COMSOL Multiphysics software considering the anisotropic material properties and the ...