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Mechanical Engineering Commons™

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2008

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Articles 331 - 360 of 567

Full-Text Articles in Mechanical Engineering

Experimental Testing And Performance Analysis Of "Room Air Cleaners", Pavan Kumar Mudiya Jan 2008

Experimental Testing And Performance Analysis Of "Room Air Cleaners", Pavan Kumar Mudiya

ETD Archive

HMI industries are the manufacture of the air cleaners and vacuum cleaners, in which a solution is adapted for the current model of the volute to the new design of the volute in order to calculate the "Clean Air Delivery rate" and qualify for the "Energy Star requirements". For the above model to be employed as a Energy Star certificate, a test rig was made in which "air velocity" and "flow rate" was calculated for the three different air cleaners in two cases i.e. (i) three different air cleaners with different filters and different rpm's (ii) three different air cleaners …

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Radiation View Factors Between A Disk And The Interior Of A Class Of Axisymmetric Bodies Including Converging Diverging Rocket Nozzles, Mark Richard Murad Jan 2008

Radiation View Factors Between A Disk And The Interior Of A Class Of Axisymmetric Bodies Including Converging Diverging Rocket Nozzles, Mark Richard Murad

ETD Archive

A general symbolic exact analytic solution is developed for the radiation view factors including shadowing by the throat between a divergence thin gas disk between the combustion chamber and the beginning of the rocket nozzle radiating energy to the interior downstream of the nozzle contour for a class of coaxial axisymmetric converging diverging rocket nozzles. The radiation view factors presented in this thesis for the projection which are blocked or shadowed through the throat radiating downstream to the contour have never been presented before in the literature. It was found that the curvature of the function of the contour of …

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Application Of Reverse Engineering And Rapid Prototyping To Casting, Venkat Deepak Kolar Jan 2008

Application Of Reverse Engineering And Rapid Prototyping To Casting, Venkat Deepak Kolar

ETD Archive

The automotive industry has an increasing need for the re manufacturing of spare parts through reverse engineering. In this thesis we will review the techniques used in Fused Deposition Modeling system for the reverse engineering of vintage automotive parts. The objective of the project is to be able to generate part-to-CAD and CAD-to-part reconstruction of the original part for future usage. These newly created 3D models will be added to the 3D Part Database. The integration of reverse engineering and rapid prototyping is being used for getting product to the market quickly by resolving a long-standing conflict between design and …

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Probabilistic Finite Element Heat Transfer And Structural Analysis Of A Cone-Cylinder Pressure Vessel, Omar Haddad Jan 2008

Probabilistic Finite Element Heat Transfer And Structural Analysis Of A Cone-Cylinder Pressure Vessel, Omar Haddad

ETD Archive

Stress analysis of a cone-cylinder pressure vessel was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for overall Von Mises stresses due to the structural and thermodynamic random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design and make it cost effective. The analysis leads to the selection of the appropriate measurements to be used in structural and heat transfer analysis and to the identification of both the most …

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Mathematical Analysis Of A Geothermal System, Ivan P. Erceg Jan 2008

Mathematical Analysis Of A Geothermal System, Ivan P. Erceg

ETD Archive

The issue being examined is to design a more economical and efficient therefore superior geothermal system than currently in use in industry. Current geothermal systems are designed and built 300 feet into the ground. After researching ground temperature gradients for Ohio we found out that below 10 feet of depth, the temperature varies by 1 degree Fahrenheit per 100 feet depth. Our goal is to utilize the heat as close to the surface as possible and greatly reduce the need to dig so deeply into the ground. The procedure used to go about designing a superior geothermal system is to …

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Conduction In Rectangular Plates With Boundary Temperatures Specified, James V. Beck, Neil T. Wright, A. Haji-Sheikh, Kevin D. Cole, Donald E. Amos Jan 2008

Conduction In Rectangular Plates With Boundary Temperatures Specified, James V. Beck, Neil T. Wright, A. Haji-Sheikh, Kevin D. Cole, Donald E. Amos

Department of Mechanical and Materials Engineering: Faculty Publications

Steady-state components of heat conduction solutions may have very slowly convergent series for temperatures and non-convergent heat fluxes for temperature boundary conditions. Previous papers have proposed methods to remove these convergence problems. However, even more effective procedures based on insights of Morse and Feshbach are given herein. In some cases it is possible to replace poorly-convergent or non-convergent series by closed-form algebraic solutions. Examples are given.

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Test 1898a: Case Ih Magnum 215 Diesel, Nebraska Tractor Test Lab Jan 2008

Test 1898a: Case Ih Magnum 215 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Nebraska Summary: S721 New Holland T4030, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S721 New Holland T4030, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Nebraska Summary: S765 New Holland Td5030, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S765 New Holland Td5030, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Test 1938a: Case Ih Dx 50 Also Farmall 50, Nebraska Tractor Test Lab Jan 2008

Test 1938a: Case Ih Dx 50 Also Farmall 50, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Factors Affecting The Spread Of A Bioterrorist Agent Throughout A Building, William A. Cantrell Jan 2008

Factors Affecting The Spread Of A Bioterrorist Agent Throughout A Building, William A. Cantrell

Inquiry: The University of Arkansas Undergraduate Research Journal

Bioterrorism has become a greater concern for Americans since the 2001 anthrax letters. Recent studies have explored the possibilities of biological attacks, and most deal with possible large-scale attacks. However, there is reason to believe that small-scale attacks are more likely. Even though there have been investigations of the postal delivery system and the spread of bioagents through mail, few if any studies have looked at attack on a single building and the resultant spread form room to room. One particular method of attacking a building would be a single-even release of an aerosol bioagent in the building. This paper …

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Thermodynamically Coupled Transport In Simple Catalytic Reactions, Yaşar Demirel Jan 2008

Thermodynamically Coupled Transport In Simple Catalytic Reactions, Yaşar Demirel

Yaşar Demirel Publications

Considerable work published on chemical reaction-diffusion systems investigates mainly mathematically coupled nonlinear differential equations. This study presents the modeling of a simple elementary chemical reaction with thermodynamically and mathematically coupled heat and mass transport with external mass and heat transfer resistances. The thermodynamic coupling refers that a flow occurs without or against its primary thermodynamic driving force, which may be a gradient of temperature or chemical potential. The modeling is based on the linear nonequilibrium thermodynamics approach and phenomenological equations by assuming that the system is in the vicinity of global equilibrium. This approach does not need detailed coupling mechanisms. …

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Nebraska Summary: S648 Massey Ferguson 8650, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S648 Massey Ferguson 8650, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Semi-Analytical Complex Variable Based Stochastic Finite Element Method, Weiya Jin Jan 2008

Semi-Analytical Complex Variable Based Stochastic Finite Element Method, Weiya Jin

Mechanical and Aerospace Engineering Dissertations - Archive

The stochastic finite element method (SFEM) is an approach that allows an analyst to define material, load, and geometry parameters as random variables to represent uncertainty in an engineering problem. The method is then used to estimate the probability of exceeding specified performance thresholds. A necessary ingredient for this analysis is consistent, accurate and efficient algorithms for computing finite element response sensitivities. In this work, the semi-analytical complex variable method (SACVM) is introduced as a method for computing accurate response sensitivities of stochastic models. The SACVM incorporates the complex variable method (CVM) with the semi-analytical method (SAM). It takes advantage …

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Effects Of Edge Distance, Hole Size Ratio And Hole Spacing On Peak Stresses Of Composite Laminate With Multiple Holes, Manishkumar Kheradiya Jan 2008

Effects Of Edge Distance, Hole Size Ratio And Hole Spacing On Peak Stresses Of Composite Laminate With Multiple Holes, Manishkumar Kheradiya

Mechanical and Aerospace Engineering Theses - Archive

Unlike isotropic material, the stress distribution of laminate with a hole varies with its size, its material properties and fiber orientations of each layer. Moreover, presence of a hole in the neighborhood of another hole may also affect their stress distribution, too. The major objective of this study is to determine stress distribution of finite width laminated composite having multiple holes. The effect of stress concentration due to presence of holes in each angle ply of laminated composite is a focus of this study. Three dimensional finite element models are developed to determine the stress distribution in laminate using commercial …

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Characterization And Cooling Capacity Enhancement Of A Porous Ceramic Wick Based Coldplate, Mauricio Adrian Salinas Jan 2008

Characterization And Cooling Capacity Enhancement Of A Porous Ceramic Wick Based Coldplate, Mauricio Adrian Salinas

Mechanical and Aerospace Engineering Dissertations - Archive

Current passive cooling methods of aerospace and military, high heat-flux electronics include the use of thermal planes made of exotic metal alloys, which have been designed, at a great expense, to have high thermal conductivity and low density (i.e. light weight). Also, phase change modules composed of a metal matrix saturated with a solid phase change material are being employed for systems requiring a transient cooling scheme such as expendable weapons. This method requires the heat to be transferred from the source location, through the metal matrix (typically a porous aluminum foam), to the available phase change material. Preliminary empirical …

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Thermal Design Optimization Of Internally Cooled Turbine Blades, James Daniel Ruiz Jan 2008

Thermal Design Optimization Of Internally Cooled Turbine Blades, James Daniel Ruiz

Mechanical and Aerospace Engineering Theses - Archive

This paper outlines the use of Computational Fluid Dynamics (CFD) and Genetic Algorithm (GA) Optimization to enhance the design of a 3-dimensional internally cooled turbine blade. The optimization code utilizes principles of Genetic Algorithms to optimize (i.e. minimize) the integrated heat flux through the turbine blade. The optimization is accomplished by adjusting the size and position (within pre-determined constraints) of cooling passages internal to the turbine blade. Starting with an aerodynamically optimized airfoil shape, cooling passage designs are generated by the optimization process and coupled with boundary and airfoil domains. The analysis becomes a Conjugate Heat Transfer (CHT) problem analyzing …

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Development Of Spectral And Wavelet Time-Of-Flight Methods For Propagating Shock And Detonation Waves, Alfredo Albert Ortiz Jan 2008

Development Of Spectral And Wavelet Time-Of-Flight Methods For Propagating Shock And Detonation Waves, Alfredo Albert Ortiz

Mechanical and Aerospace Engineering Theses - Archive

An accurate time delay estimate for a propagating disturbance, including an estimate of its uncertainty, is important in many areas of science. Several techniques were developed for determining the propagation time of a shock and detonation wave. The speed of the propagating wave was then determined by the time delay estimates provided for the best techniques. The techniques used ranged from the commonly used time-of-flight method to a nonstationary cross-spectral density phase method that provided a statistical estimation of the propagation time. The time delay results for a shock tube experiment showed that most of the methods had difficulties in …

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Thermal Analysis Of Pulse Detonation Engines, Raghu Raman Ghandikota Jan 2008

Thermal Analysis Of Pulse Detonation Engines, Raghu Raman Ghandikota

Mechanical and Aerospace Engineering Theses - Archive

The pulse detonation engine (PDE) is a compact system that can be modeled thermodynamically by the Humphrey cycle and is capable of high efficiency. The rapid heat release for stochiometric fuel/oxidizer ratios results in developing high temperatures. The high temperatures produced during its operation can cause the engine to fail. Thus, operating this engine for a longer duration would become dubious if the temperatures are not dissipated from it. The current research aims to perform a preliminary thermal analysis. This analysis consists of two steps. The first step is to determine the heat dissipated from the engine using the unsteady …

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Effect Of Pullout And Torsional Strength Of Composites With Co-Molded Thread Inserts, Dan L. Reller Jan 2008

Effect Of Pullout And Torsional Strength Of Composites With Co-Molded Thread Inserts, Dan L. Reller

Mechanical and Aerospace Engineering Theses - Archive

Rotorcraft transmission housings and drive system components are typically made from cast metals due to their highly complex geometries. Utilizing composite materials offers potential to reduce weigh and manufacturing cost while increasing corrosive resistance and extending part life. Traditional compression molded composites have not been utilized in aerospace because they typically experience low fiber volume fraction. Currently there are numerous materials which offer opportunities for composites in drive system housing applications and also offer the ability to co-mold details to reduce post mold operations. One of the issues associated with composite structures is the ability to fasten them to one …

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Electromagnetic Flow Control: A Review And Experimental Development And Testing Of A Compact Actuator, Eric Braun Jan 2008

Electromagnetic Flow Control: A Review And Experimental Development And Testing Of A Compact Actuator, Eric Braun

Mechanical and Aerospace Engineering Theses - Archive

This thesis is divided into two sections which both relate to the field of magnetohydrodynamics and particularly electromagnetic flow control (EMFC). The first section contains a review of recent research in EMFC. The second section presents the experimental results of a compact EMFC actuator designed for use at low speeds where the flow conductivity is raised by conductive seed particle injection.Fifty years ago, publications began to discuss the possibilities of using EMFC to improve aerodynamic performance. This led to an era of research that focused on coupling the fundamentals of magnetohydrodynamics (MHD) with propulsion, control, and power generation systems. Unfortunately, …

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Finite Element Analysis Of Helicopter Main Rotor Hub Plates To Evaluate The Possibility Of Increasing The Time To Retirement, Douglas Wittig Jan 2008

Finite Element Analysis Of Helicopter Main Rotor Hub Plates To Evaluate The Possibility Of Increasing The Time To Retirement, Douglas Wittig

Mechanical and Aerospace Engineering Theses - Archive

Rotorcraft main rotor systems have multiple components that are subject to very high loads and moments. These loads and moments dictate the life expectancy of the parts based upon the components material of composition. This project will primarily focus on the upper and lower hub plates on the main rotor system of a typical four bladed commercial helicopter. The upper and lower plates are machined from 7075-T73 aluminum forgings. The upper and lower plates were laboratory fatigue tested during product development as supporting parts in the test of the main rotor assembly. With recent advances in finite element analysis, there …

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Fabrication Of Complex 3d Micro-Scale Scaffolds And Drug Delivery Devices Using Dynamic Mask Projection Microstereolithography, Jae-Won Choi, In-Baek Park, Ryan B. Wicker, Seok-Hee Lee, Ho-Chan Kim Jan 2008

Fabrication Of Complex 3d Micro-Scale Scaffolds And Drug Delivery Devices Using Dynamic Mask Projection Microstereolithography, Jae-Won Choi, In-Baek Park, Ryan B. Wicker, Seok-Hee Lee, Ho-Chan Kim

Mechanical Engineering Faculty Research

Microstereolithography (μSL) technology can fabricate three-dimensional (3D) tissue engineered scaffolds with controlled biochemical and mechanical micro-architectures. A μSL system for tissue engineering was developed using a Digital Micromirror Device (DMDTM) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for crosslinking the photoreactive polymer solution. The μSL system was designed with x-y resolution of ~2 μm and a vertical (z) resolution of ~1 μm. To demonstrate the use of μSL in tissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weight of ~1200 Da. The viscosity of the PPF was reduced to ~150 cP (at …

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A Simulation-Based Approach For Dock Allocation In A Food Distribution Center, Balagopal Gopakumar, Suvarna Sundaram, Shengyong Wang Jan 2008

A Simulation-Based Approach For Dock Allocation In A Food Distribution Center, Balagopal Gopakumar, Suvarna Sundaram, Shengyong Wang

Mechanical Engineering Faculty Research

This research endeavor focused on the warehouse receiving process at a large food distribution center, which comprises of trucks with goods reaching the destination warehouse, unloading and finally putting away the contents to the specific aisles. Discrete event simulation was used to model the current system’s functioning and to identify operational inefficiencies which were quantified through a detailed value stream mapping exercise. Inspired by ‘lean’ philosophy, a dock allocation algorithm was designed to take into account the relationship between the dock location and the destination aisle to ‘optimally’ assign the trucks to the docks. After validating the baseline, new scenarios …

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An Evaluation Of A Stem Program For Middle School Students On Learning Disability Related Ieps, Paul C. Lam, Dennis Doverspike, Julie Zhao, Jiang Zhe, Craig C. Menzemer Jan 2008

An Evaluation Of A Stem Program For Middle School Students On Learning Disability Related Ieps, Paul C. Lam, Dennis Doverspike, Julie Zhao, Jiang Zhe, Craig C. Menzemer

Mechanical Engineering Faculty Research

A year long Science, Technology, Engineering and Math (STEM) program was developed for middle schools students on Individualized Education Programs (IEPs) involving learning disabilities. The workshops were designed to encourage students both on IEPs and not on IEPs to explore STEM as a future career choice by building their knowledge and confidence. The participants in the workshops included 11 students on IEPs and 15 students not on IEPs. Parents also provided feedback regarding their attitudes toward the program. The results indicated that there were increases in student participant knowledge and career interest for both the students not on IEPs and …

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A Separation Criterion And Non-Intrusive Thickness Measurement Technique For Shear-Driven Films, Mark A. Friedrich Jan 2008

A Separation Criterion And Non-Intrusive Thickness Measurement Technique For Shear-Driven Films, Mark A. Friedrich

Masters Theses

"The behavior of a shear-driven thin liquid film at a sharp expanding corner is of interest in many engineering applications. However, details of the interaction between inertial, surface tension, and gravitational forces at the corner that result in partial or complete separation of the film from the surface are not clear. The focus of this study was to develop a criterion to predict the onset of shear-driven film separation from the surface at an expanding corner as well as to develop a film thickness measurement technique that could be used to obtain an average film thickness for input into the …

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Computer Simulation Of Radio Frequency Heating Of Model Fruit Immersed In Water, Sohan Birla, Shaojin Wang, Juming Tang Jan 2008

Computer Simulation Of Radio Frequency Heating Of Model Fruit Immersed In Water, Sohan Birla, Shaojin Wang, Juming Tang

Department of Engineering Mechanics: Faculty Publications

The present study investigated the effect of different factors on temperature distribution within a spherical object in a parallel plate radio frequency (RF) heating system. A finite element-computer simulation program - FEMLAB was used to solve the electromagnetic and Navier-Stoke equations for developing a model to study the effect of dielectric properties of a model fruit and its surrounding medium. The model fruit was prepared from 1% gellan gel for experimental validation of the simulation results. The results showed that spherically-shaped samples surrounded with air between RF electrodes and placed in the proximity of electrodes would not heat uniformly. Immersing …

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Creating A Reinforcement Learning Controller For Functional Electrical Stimulation Of A Human Arm, Philip S. Thomas, Michael Branicky, Antonie Van Den Bogert, Kathleen Jagodnik Jan 2008

Creating A Reinforcement Learning Controller For Functional Electrical Stimulation Of A Human Arm, Philip S. Thomas, Michael Branicky, Antonie Van Den Bogert, Kathleen Jagodnik

Mechanical Engineering Faculty Publications

Clinical tests have shown that the dynamics of a human arm, controlled using Functional Electrical Stimulation (FES), can vary significantly between and during trials. In this paper, we study the application of Reinforcement Learning to create a controller that can adapt to these
changing dynamics of a human arm. Development and tests were done in simulation using a two-dimensional arm model and Hill-based muscle dynamics. An actor-critic architecture is used with artificial neural networks for both the actor and the critic. We begin by training it using a Proportional Derivative (PD) controller as a supervisor. We then make clinically relevant …

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Helical Axes Of Skeletal Knee Joint Motion During Running, Antonie J. Van Den Bogert, C. Reinschmidt, A. Lundberg Jan 2008

Helical Axes Of Skeletal Knee Joint Motion During Running, Antonie J. Van Den Bogert, C. Reinschmidt, A. Lundberg

Mechanical Engineering Faculty Publications

The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase …

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Development Of Optical Fiber Sensors For Distance, Refractive Index And Strain Measurement, Ayan Majumdar Jan 2008

Development Of Optical Fiber Sensors For Distance, Refractive Index And Strain Measurement, Ayan Majumdar

Mechanical and Aerospace Engineering Theses - Archive

This thesis is focused on the development of optical fiber based sensors for the measurement of distance, refractive index, and strain. The fabrication, implementation, analysis, and evaluation of the sensors are presented. The Extrinsic Fabry-Perot Interferometric (EFPI) distance sensor is one of the most popular distance sensors but it possesses an inherent drawback. When the free-space cavity distance is very small, the numbers of fringes generated are not sufficient for the distance demodulation algorithm; therefore the smallest distance it can measure is determined by the bandwidth of the light source. An optical fiber based distance sensor is developed in this …

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