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Articles 17821 - 17850 of 30239

Full-Text Articles in Mechanical Engineering

Some Project Manegement Challenges When Planning To Conduct Vertical Transportation Study, Magdelena Krstanoski Jan 2014

Some Project Manegement Challenges When Planning To Conduct Vertical Transportation Study, Magdelena Krstanoski

Early Career Technical Journal (ECTJ)

Section 9: Miscelleneous; pp. 236-240


Design And Development Of Air Powered Engine, Shalin Shah, Nisarg Patel, Kirtan Khajanchi, Vimal Savsani Jan 2014

Design And Development Of Air Powered Engine, Shalin Shah, Nisarg Patel, Kirtan Khajanchi, Vimal Savsani

Early Career Technical Journal (ECTJ)

Section 9: Miscelleneous; pp. 241-248


Asme Early Career Technical Journal (End Matter), Asme Ectc Coordinating Committee Jan 2014

Asme Early Career Technical Journal (End Matter), Asme Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Proceedings of the ASME Early Career Technical Conference, November 1-2, 2014. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama; pp. 249-250


Asme Early Career Technical Journal (Conference Program), Asme Ectc Coordinating Committee Jan 2014

Asme Early Career Technical Journal (Conference Program), Asme Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Program of the ASME Early Career Technical Conference, November 1-2, 2014. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama


An Environmentally-Friendly Design To Reduce Energy Loss By Heat Transfer Through Windows, Andrew Li Jan 2014

An Environmentally-Friendly Design To Reduce Energy Loss By Heat Transfer Through Windows, Andrew Li

Honors Theses

With windows as main areas of energy loss in residential environments, a market exists for a product to act a removable barrier which improves heat transfer for cases of extreme temperatures in seasonal weather. Such a product would allow consumers to save money in the long run without permanently losing the use of their windows when the weather is mild and such an apparatus is not needed. This project designs such a product using an assembly of polished aluminum foil for low radiation emissivity, ABS plastic for an insulating material with low conductivity, and an aluminum glass mirror pane which …


Improving Startability And Reducing Emissions In Flexfuel Spark Ignition Direct Injection Variable Cam Timing Engine, Vaibhav S. Kale Jan 2014

Improving Startability And Reducing Emissions In Flexfuel Spark Ignition Direct Injection Variable Cam Timing Engine, Vaibhav S. Kale

Dissertations, Master's Theses and Master's Reports - Open

Experimental work and analysis was done to investigate engine startup robustness and emissions of a flex-fuel spark ignition (SI) direct injection (DI) engine. The vaporization and other characteristics of ethanol fuel blends present a challenge at engine startup. Strategies to reduce the enrichment requirements for the first engine startup cycle and emissions for the second and third fired cycle at 25°C ± 1°C engine and intake air temperature were investigated.

Research work was conducted on a single cylinder SIDI engine with gasoline and E85 fuels, to study the effect on first fired cycle of engine startup. Piston configurations that included …


Water Access And Maintenance In Karonga, Malawi, Donald A. Norris Jan 2014

Water Access And Maintenance In Karonga, Malawi, Donald A. Norris

Dissertations, Master's Theses and Master's Reports - Open

This report is a case study of how Mwangalala community accesses water and how that access is maintained. Mwangalala community is located in the northern tip of Karonga district in Malawi, Africa. The case study evaluates how close the community is to meeting target 10 of the Millennium Development Goals, sustainable access to safe drinking water, and evaluates the current water system through Human Centered Design’s criteria of desirability, feasibility, and viability. It also makes recommendations to improve water security in Mwangalala community.

Data was collected through two years of immersive observation, interviews with 30 families, and observing two wells …


A Study Of Acoustic Boom Generation Due To Vibro-Acoustic Coupling In Passenger Cars, Mayuresh Pathak Jan 2014

A Study Of Acoustic Boom Generation Due To Vibro-Acoustic Coupling In Passenger Cars, Mayuresh Pathak

Dissertations, Master's Theses and Master's Reports - Open

This thesis aims at understanding the vibro-acoustic behavior related to vehicle boom in passenger cars. Acoustic boom in the 40 Hz frequency range is studied on a 2013 Chevrolet Cruze LTZ model. Impact testing, full vehicle structural and acoustic modal tests are first performed to understand, locate and test the boom phenomenon and the fluid-structure interaction between the vehicle structure and acoustic cavity. Later, different iterations like effect of door cavities, trunk cavity and rear seats are also tested to understand their participation. LMS Test.Lab software is used for data acquisition, processing and analysis of the test results.

Finite Element …


A Backing Device Based On An Embedded Stiffener And Retractable Insertion Tool For Thin-Film Cochlear Arrays, Radheshyam Tewari Jan 2014

A Backing Device Based On An Embedded Stiffener And Retractable Insertion Tool For Thin-Film Cochlear Arrays, Radheshyam Tewari

Dissertations, Master's Theses and Master's Reports - Open

Intracochlear trauma from surgical insertion of bulky electrode arrays and inadequate pitch perception are areas of concern with current hand-assembled commercial cochlear implants. Parylene thin-film arrays with higher electrode densities and lower profiles are a potential solution, but lack rigidity and hence depend on manually fabricated permanently attached polyethylene terephthalate (PET) tubing based bulky backing devices. As a solution, we investigated a new backing device with two sub-systems. The first sub-system is a thin poly(lactic acid) (PLA) stiffener that will be embedded in the parylene array. The second sub-system is an attaching and detaching mechanism, utilizing a poly(N-vinylpyrrolidone)-block-poly(d,l-lactide) (PVP-b-PDLLA) copolymer-based …


Development Of Confocal Imaging Techniques For Probing Interfacial Dynamics In Microscale, Gas-Liquid, Two-Phase Flow, Joseph E. Hernandez Jan 2014

Development Of Confocal Imaging Techniques For Probing Interfacial Dynamics In Microscale, Gas-Liquid, Two-Phase Flow, Joseph E. Hernandez

Dissertations, Master's Theses and Master's Reports - Open

Micro-scale, two-phase flow is found in a variety of devices such as Lab-on-a-chip, bio-chips, micro-heat exchangers, and fuel cells. Knowledge of the fluid behavior near the dynamic gas-liquid interface is required for developing accurate predictive models. Light is distorted near a curved gas-liquid interface preventing accurate measurement of interfacial shape and internal liquid velocities. This research focused on the development of experimental methods designed to isolate and probe dynamic liquid films and measure velocity fields near a moving gas-liquid interface. A high-speed, reflectance, swept-field confocal (RSFC) imaging system was developed for imaging near curved surfaces.

Experimental studies of dynamic gas-liquid …


Use Of An Electrical Impedance Tomography Method To Detect And Track Fractures In A Gelatin Medium, Evan G. Lucas Jan 2014

Use Of An Electrical Impedance Tomography Method To Detect And Track Fractures In A Gelatin Medium, Evan G. Lucas

Dissertations, Master's Theses and Master's Reports - Open

Electrical impedance tomography is applied to the problem of detecting, locating, and tracking fractures in ballistics gelatin. The hardware developed is intended to be physically robust and based on off-the-shelf hardware. Fractures were created in two separate ways: by shooting a .22 caliber bullet into the gelatin and by injecting saline solution into the gelatin. The .22 caliber bullet created an air gap, which was seen as an increase in resistivity. The saline solution created a fluid filled gap, which was seen as a decrease in resistivity. A double linear array was used to take data for each of the …


Thickness Measurement Of Dynamic Thin Liquid Films Generated By Plug-Annular Flow In Non-Wetting Microchannels, David C. Deisenroth Jan 2014

Thickness Measurement Of Dynamic Thin Liquid Films Generated By Plug-Annular Flow In Non-Wetting Microchannels, David C. Deisenroth

Dissertations, Master's Theses and Master's Reports - Open

Surface tension forces are significant at millimeter length-scales, causing profoundly different flow morphologies in microchannels than in macroscale flows. The existence and morphology of thin liquid films is particularly relevant for predicting performance and operational stability of devices containing microscale two phase flows. Analytical, computational, and experimental methods previously employed in the study of thin liquid films are discussed. Thicknesses before and after a novel film morphology, referred to as a `shock,' are measured with a novel film thickness measurement technique that uses confocal microscopy. Film thicknesses predicted by previous work are compared to experimental results. Methods for increasing the …


Density Of Amorphous Carbon By Using Density Functional Theory, Sorayot Chinkanjanarot Jan 2014

Density Of Amorphous Carbon By Using Density Functional Theory, Sorayot Chinkanjanarot

Dissertations, Master's Theses and Master's Reports - Open

Amorphous carbon has been investigated for a long time. Since it has the random orientation of carbon atoms, its density depends on the position of each carbon atom. It is important to know the density of amorphous carbon to use it for modeling advance carbon materials in the future. Two methods were used to create the initial structures of amorphous carbon. One is the random placement method by randomly locating 100 carbon atoms in a cubic lattice. Another method is the liquid-quench method by using reactive force field (ReaxFF) to rapidly decrease the system of 100 carbon atoms from the …


Understanding Chassis Inputs From The Rear Suspension Of A Snowmobile, Jamie L. Kleinendorst Jan 2014

Understanding Chassis Inputs From The Rear Suspension Of A Snowmobile, Jamie L. Kleinendorst

Dissertations, Master's Theses and Master's Reports - Open

Today’s snowmobile industry faces great challenges in the field of noise & vibration. The area of main concern is the pass-by noise restriction defined by the Society of Automotive Engineers (SAE) test standard J192, with a maximum sound pressure level of 78 dB(A) being required by many states and national parks. To continue meet or beat this requirement without effecting machine performance, a deeper understanding of the sound transfer paths is required. This thesis examines the transfer paths created by the tunnel, rear suspension, drive shaft, and rubber composite track, with the primary source being suspension input through the ground. …


A Proposed Return Algorithm For Elastoplastic Constitutive Relations, David A. Cooper, David L. Littlefield Jan 2014

A Proposed Return Algorithm For Elastoplastic Constitutive Relations, David A. Cooper, David L. Littlefield

Early Career Technical Journal (ECTJ)

Section 5: Numerical Methods; pp. 121-125


Gravitational Stabilization Methods For Hydrocodes, Gerald Pekmezi, David Littlefield, Stephen Akers, Kent Danielson Jan 2014

Gravitational Stabilization Methods For Hydrocodes, Gerald Pekmezi, David Littlefield, Stephen Akers, Kent Danielson

Early Career Technical Journal (ECTJ)

Section 5: Numerical Methods; pp. 150-157


Unidirectional Rotary Tendency Of A Wave-Driven Rotor, Yingchen Yang Jan 2014

Unidirectional Rotary Tendency Of A Wave-Driven Rotor, Yingchen Yang

Mechanical Engineering Faculty Publications

Ocean waves can directly drive WECs (wave energy converters) to perform two types of motion—reciprocating motion and unidirectional rotary motion. In general, the efficiency of a reciprocating WEC is strongly wave-frequency dependent, whereas the efficiency of a rotary WEC can be somewhat wave-frequency independent. To date, a huge majority of WEC technologies under development in industry belong to the reciprocating class, and only a few WEC concepts fall in the unidirectional rotary class. In the present work, a wave-driven rotor for unidirectional rotary motion was proposed and characterized. A numerical tool has been developed for characterization of the rotor’s unidirectional …


Thermal Analysis, Microstructural Characterization And Nanoindentation For Electron Beam Additive Manufacturing, Bo Chang, Xibing Gong, Xiaoqing Wang, Kevin Chou Jan 2014

Thermal Analysis, Microstructural Characterization And Nanoindentation For Electron Beam Additive Manufacturing, Bo Chang, Xibing Gong, Xiaoqing Wang, Kevin Chou

Early Career Technical Journal (ECTJ)

Section 7: Design & Manufacturing; pp. 196-203


A Novel Microgrid Demand-Side Management System For Manufacturing Facilities, Terance J. Harper, William J. Hutzel, James C. Foreman, Aaron L. Adams, Athula Kulatunga Jan 2014

A Novel Microgrid Demand-Side Management System For Manufacturing Facilities, Terance J. Harper, William J. Hutzel, James C. Foreman, Aaron L. Adams, Athula Kulatunga

Purdue Polytechnic Masters Theses

Thirty-one percent of annual energy consumption in the United States occurs within the industrial sector, where manufacturing processes account for the largest amount of energy consumption and carbon emissions. For this reason, energy efficiency in manufacturing facilities is increasingly important for reducing operating costs and improving profits. Using microgrids to generate local sustainable power should reduce energy consumption from the main utility grid along with energy costs and carbon emissions. Also, microgrids have the potential to serve as reliable energy generators in international locations where the utility grid is often unstable.

For this research, a manufacturing process that had approximately …


Strain Modulations As A Mechanism To Reduce Stress Relaxation In Laryngeal Tissues, Eric J. Hunter, Thomas Siegmund, Roger W. Chan Jan 2014

Strain Modulations As A Mechanism To Reduce Stress Relaxation In Laryngeal Tissues, Eric J. Hunter, Thomas Siegmund, Roger W. Chan

School of Mechanical Engineering Faculty Publications

Vocal fold tissues in animal and human species undergo deformation processes at several types of loading rates: a slow strain involved in vocal fold posturing (on the order of 1 Hz or so), cyclic and faster posturing often found in speech tasks or vocal embellishment (1–10 Hz), and shear strain associated with vocal fold vibration during phonation (100 Hz and higher). Relevant to these deformation patterns are the viscous properties of laryngeal tissues, which exhibit non-linear stress relaxation and recovery. In the current study, a large strain time-dependent constitutive model of human vocal fold tissue is used to investigate effects …


Pedestrian Head Protection During Car To Pedestrian Accidents: In The Event Of Primary Impact With Vehicle And Secondary Impact With Ground, Vishal Gupta Jan 2014

Pedestrian Head Protection During Car To Pedestrian Accidents: In The Event Of Primary Impact With Vehicle And Secondary Impact With Ground, Vishal Gupta

Wayne State University Dissertations

Current regulations for assessing pedestrian safety use a simplified test setup that ignores many real-world factors. In particular, the level of protection is assessed using a free-motion headform impacting the vehicle's hood at a fixed angle. As such, this test setup does not capture the effect due to the vehicle front-end profile, nor does it comprehend injury due to a possible secondary impact of the pedestrian's head with ground. This thesis aims to numerically simulate vehicle to pedestrian crashes to develop knowledge that may suggest ways to improve safety above and beyond the regulatory tests. Inputs to the simulations include …


Study Of Chaotic Ultrasound And Frequency Sweep Excitations In Sonic Ir Nde Technology, Ding Zhang Jan 2014

Study Of Chaotic Ultrasound And Frequency Sweep Excitations In Sonic Ir Nde Technology, Ding Zhang

Wayne State University Dissertations

Sonic Infrared (IR) Imaging Nondestructive Evaluation (NDE) technology has shown inherent advantages, such as fast detection for all direction and all dimension flaws, for both metal and composite materials. The purpose of this dissertation is to study and investigate the physical process of two most important methods, frequency sweep excitation and chaotic excitation, to improve the defect detection ability of Sonic IR technology.

The tool used in our study is known as finite element analysis (FEA). According to test process of Sonic IR technology, some special technologies were developed in FEA simulation, such as creating cracks with flat contact surfaces …


Communication Protocol Design Considerations For Highway Vehicle Platoons And Enhanced Networked Robustness By Stochastic Dithers, Lijian Xu Jan 2014

Communication Protocol Design Considerations For Highway Vehicle Platoons And Enhanced Networked Robustness By Stochastic Dithers, Lijian Xu

Wayne State University Dissertations

Highway platooning of vehicles has been identified as a promising framework in

developing intelligent transportation systems. By autonomous or semi-autonomous

vehicle control and inter-vehicle coordination, an appropriately managed platoon can

potentially offer enhanced safety, improved highway utility, increased fuel economy,

and reduced emission. This thesis is focused on quantitative characterization of impact

of communication information structures and contents on platoon safety. By

comparing different information structures which combine front sensors, rear sensors,

and wireless communication channels, and different information contents such

as distances, speeds, and drivers' actions, we reveal a number of intrinsic relationships

between vehicle coordination and communications in …


High-Performance Accelerometer Based On Asymmetric Gapped Cantilevers For Physiological Acoustic Sensing, Yating Hu Jan 2014

High-Performance Accelerometer Based On Asymmetric Gapped Cantilevers For Physiological Acoustic Sensing, Yating Hu

Wayne State University Dissertations

Continuous or mobile monitoring of physiological sounds is expected to play important role in the emerging mobile healthcare field. Because of the miniature size, low cost, and easy installation, accelerometer is an excellent choice for continuous physiological acoustic signal monitoring. However, in order to capture the detailed information in the physiological signals for clinical diagnostic purpose, there are more demanding requirements on the sensitivity/noise performance of accelerometers. In this thesis, a unique piezoelectric accelerometer based on the asymmetric gapped cantilever which exhibits significantly improved sensitivity is extensively studied. A meso-scale prototype is developed for capturing the high quality cardio and …


Non-Linear Robust Observers For Systems With Non-Collocated Sensors And Actuators, Constantine Mastory Jan 2014

Non-Linear Robust Observers For Systems With Non-Collocated Sensors And Actuators, Constantine Mastory

Wayne State University Dissertations

Challenges in controlling highly nonlinear systems are not limited to the development of sophisticated control algorithms that are tolerant to significant modeling imprecision and external disturbances. Additional challenges stem from the implementation of the control algorithm such as the availability of the state variables needed for the computation of the control signals, and the adverse effects induced by non-collocated sensors and actuators.

The present work investigates the adverse effects of non-collocated sensors and actuators on the phase characteristics of flexible structures and the ensuing implications on the performance of structural controllers. Two closed-loop systems are considered and their phase angle …


Jp-8 Surrogates For Diesel Engine Application: Development, Validation, And Cfd Simulation, Amit Shrestha Jan 2014

Jp-8 Surrogates For Diesel Engine Application: Development, Validation, And Cfd Simulation, Amit Shrestha

Wayne State University Dissertations

Recently, diesel engine cycle simulation has been acknowledged as an effective way for the development and performance optimization of compression ignition engines operating on a variety of fuels. The goal of this research was, therefore, to develop a JP-8 surrogate with a limited number of fuel components so that its chemical mechanism could be developed for its use with computational fluid dynamics (CFD) codes for enabling time-efficient diesel engine cycle simulation. In order to achieve this goal, a new approach was developed for the formulation of surrogate for compression ignition engine application. The development approach required the surrogate to match …


Evaluation Of Nozzle Geometry On High Pressure Gasoline Direct Injection Spray Atomization, Mark Shost Jan 2014

Evaluation Of Nozzle Geometry On High Pressure Gasoline Direct Injection Spray Atomization, Mark Shost

Wayne State University Dissertations

This research presents a critical study of injector nozzle geometry on high-pressure Gasoline Direct Injection, GDi, injector spray morphology. The study was conducted with the aid of multi-fluid Volume-of-Fluid, Large-Eddy-Simulation, VOF-LES, method. Alternative nozzle geometries, that are the subject of current interest including varying nozzle hole length to diameter ratio, counter-bore presence and nozzle-hole skew-angle geometry, are studied in detail in order to provide insight into their specific influence on spray plume targeting and jet primary breakup characteristics. A comparison of the simulation results with near-field shadowgraph and Mie scatter imaging as well as phase-contrast x-ray imaging is provided. When …


Finite Element Analysis Of Shear Resistant Mechanisms For Biolaminate Interfaces, Matthew Nelms Jan 2014

Finite Element Analysis Of Shear Resistant Mechanisms For Biolaminate Interfaces, Matthew Nelms

Electronic Theses and Dissertations

The Alligator gar possesses a flexible dermal armor consisting of overlapping ganoid scales. Each scale is a bilayer hydroxyapatite and collagen-based bio-laminate for protection against predation. The exoskeleton fish scale is comprised of a stiff outer ganoine layer, a characteristic "sawtooth" pattern at the interface and a compliant bone inner layer with all materials exhibiting a decreasing elastic modulus, yield strength and density through the thickness. Experiments on ganoid scales revealed properties such as damage mitigation and energy dissipation that are unique to biological dermal armor. The objective of this investigation is to develop a fundamental understanding of the stress …


Visualizing Interior And Exterior Jet Aircraft Noise, Manmohan Singh Moondra Jan 2014

Visualizing Interior And Exterior Jet Aircraft Noise, Manmohan Singh Moondra

Wayne State University Dissertations

In today's competitive aerospace industry, the quest for quiet has drawn significant attention to both the interior and exterior design of an airplane. Understanding the noise generation mechanisms of a jet aircraft is a crucial first step toward developing the most cost-effective noise and vibrations abatement methods. In this investigation, the Helmholtz Equation Least Squares (HELS) based nearfield acoustic holography will be used to understand noise transmission caused by jet engine and turbulence into the fuselage of a jet aircraft cruising at 30,000 ft.

Modern propulsive jet engines produce exterior noise sources with a high amplitude noise field and complicated …


Nebraska Summary: S944 Case-Ih Farmall 115c, Nebraska Tractor Test Lab Jan 2014

Nebraska Summary: S944 Case-Ih Farmall 115c, 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 …