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2011

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Articles 31 - 60 of 930

Full-Text Articles in Mechanical Engineering

Product And Process Based Assembly Time Estimation In Engineering Design, Michael Miller Dec 2011

Product And Process Based Assembly Time Estimation In Engineering Design, Michael Miller

All Theses

This thesis presents the research and development of two assembly time estimation techniques for the automotive industry. Both of these techniques are capable of being implemented early in the product life-cycle of a vehicle and require information available in this phase. Currently, assembly time estimation is performed after production has begun and is a tedious manual process requiring hours of motion-time method studies for each assembly activity. The techniques proposed in this thesis can both be performed prior to the start of production and are capable of being performed automatically after the initial mapping.
The first assembly time estimation technique …


Management Theories In Manufacturing, James Nathan Webster Dec 2011

Management Theories In Manufacturing, James Nathan Webster

Graduate Research Papers

The principles and ideology of management have been around for thousands of years. "Before industrialization, organizations were primarily the household, the tribe, the church, the military, and government" (Wren, 1987, p. 13). It was very rare for people to gather and organize outside of these structures prior to the industrial revolution. As mankind and civilization have progressed, the power of organizations has shifted throughout time. In the time of Confucius, government positions were of the utmost respect, and Confucius taught that positions of power "should go to men of proven merit and ability" (Wren, 1987, p. 14). The ancient Egyptians …


Raytheon Uav Launcher, Chad Amonn, Spencer Chin, Alexander (Alex) Deuitch, Mark Jastrzebski Dec 2011

Raytheon Uav Launcher, Chad Amonn, Spencer Chin, Alexander (Alex) Deuitch, Mark Jastrzebski

Mechanical Engineering

No abstract provided.


An Investigation Into Temperature Trending In Railroad Tapered Roller Bearings Through Vibration Monitoring Techniques, Rafael Kristian Maldonado Dec 2011

An Investigation Into Temperature Trending In Railroad Tapered Roller Bearings Through Vibration Monitoring Techniques, Rafael Kristian Maldonado

Theses and Dissertations - UTB/UTPA

A series of laboratory experiments have been conducted at The University of Texas-Pan American to investigate the cause of bearing “temperature trending.” A combination of theoretical and experimental studies has identified potential sources for the abrupt changes in temperature often seen in railroad bearings. Previous studies suggest the possibility of vibration induced roller misalignment as the root cause for temperature trending. Subsequent research conducted by the UTPA team was designed to provide evidence through vibration monitoring techniques for the proposed hypothesis. To that end, a dynamic bearing tester was used to run four bearings at various speeds and loads experienced …


Anisotropic Thermal Property Measurement Of Carbon-Fiber/Epoxy Composite Materials, Tian Tian Dec 2011

Anisotropic Thermal Property Measurement Of Carbon-Fiber/Epoxy Composite Materials, Tian Tian

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

This work originated from a need for understanding heat transfer in carbon-fiber/epoxy natural-gas tanks undergoing rapid heating during refilling. The dissertation is focused on the determination of the anisotropic thermal properties of carbon-fiber/epoxy composite materials for in-plane and through-thickness directions. An effective anisotropic parameter estimation system consisting of the 3ω experimental technique and an anisotropic two-dimensional heat transfer model is developed.

In the present work, the 3ω method, an experimental technique that has been well established to evaluate the thermal properties of isotropic materials, especially thin film materials, is extended to treat the thermal properties of bulk anisotropic …


Design, Analysis, And Testing Of In Vivo Surgical Robots, Tyler David Wortman Dec 2011

Design, Analysis, And Testing Of In Vivo Surgical Robots, Tyler David Wortman

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

Advances in technology have shaped the history of surgical procedures. Recent developments have allowed surgical procedures to become less invasive than traditional open procedures. The transition to Minimally Invasive Surgery (MIS) has resulted in decreased recovery times, improved cosmetic results, and reduced costs. For these reasons, there is interest in further reducing the invasiveness of surgical procedures by accessing the abdominal cavity through a single incision, such as with Laparoendoscopic Single-Site (LESS) surgery. Added complexities, such as unintuitive controls and limited dexterity, prevent the widespread adoption of LESS for complex surgical procedures. Multi-functional in vivo surgical robots have been designed …


Strength Of Polycrystalline Ceramics Under Shock Compression, Jianbin Zhu Dec 2011

Strength Of Polycrystalline Ceramics Under Shock Compression, Jianbin Zhu

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

Determinations of Some polycrystalline ceramics’ strength properties and inelastic deformation mechanisms in the shocked state are critically important to the design and optimization of armor structures involving these materials. In this work, multiscale modeling and simulations have been carried out to study strength of the effects of polycrystalline microstructure, crystal anisotropy, porosity, and their interactions with microscopic deformation/damage mechanisms on the responses of several polycrystalline ceramics under shock compression and to extract their shock strengths from the wave profiles measured in the related plate impact shock wave experiments.

With a mesoscopic computational model, the roles of intragranular microplasticity and deformation …


Improving The Efficiency Of Lpg Compression Ignition Engines For Passenger Cars Through Waste Heat Recovery, Alberto Boretti Dec 2011

Improving The Efficiency Of Lpg Compression Ignition Engines For Passenger Cars Through Waste Heat Recovery, Alberto Boretti

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The turbocharged direct injection lean burn Diesel engine is the most efficient now in production for transport applications with full load brake efficiencies up to 40 to 45% and reduced penalties in brake efficiencies reducing the load by the quantity of fuel injected. the secrets of this engine's performances are the high compression ratio and the lean bulk combustion mostly diffusion controlled in addition to the partial recovery of the exhaust energy to boost the charging efficiency. the major downfalls of this engine are the carbon dioxide emissions and the depletion of fossil fuels using fossil diesel, the energy security …


Alternative Crankshaft Mechanisms And Kinetic Energy Recovery Systems For Improved Fuel Economy Of Light Duty Vehicles, Alberto Boretti, Houshsng Masudi, Joseph Scalzo Dec 2011

Alternative Crankshaft Mechanisms And Kinetic Energy Recovery Systems For Improved Fuel Economy Of Light Duty Vehicles, Alberto Boretti, Houshsng Masudi, Joseph Scalzo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The introduction of advanced internal combustion engine mechanisms and powertrains may improve the fuel conversion efficiency of an engine and thus reduce the amount of energy needed to power the vehicle. the paper presents a novel design of a variable compression ratio advanced spark ignition engine that also permits an expansion ratio that may differ from the induction stroke therefore generating an Atkinson cycle effect. the stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. the variable ratio of maximum to minimum in-cylinder volumes also …


Efficient Uncertainty Quantification In Multidisciplinary Analysis Of A Reusable Launch Vehicle, Benjamin R. Bettis, Serhat Hosder, Tyler Winter Dec 2011

Efficient Uncertainty Quantification In Multidisciplinary Analysis Of A Reusable Launch Vehicle, Benjamin R. Bettis, Serhat Hosder, Tyler Winter

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The objective of this study was to apply a recently developed uncertainty quantification framework to the multidisciplinary analysis of a reusable launch vehicle (RLV). This particular framework is capable of efficiently propagating mixed (inherent and epistemic) uncertainties through complex simulation codes. the goal of the analysis was to quantify uncertainty in various output parameters obtained from the RLV analysis, including the maximum dynamic pressure, cross-range, range, and vehicle takeoff gross weight. Three main uncertainty sources were treated in the simulations: (1) reentry angle of attack (inherent uncertainty), (2) altitude of the initial reentry point (inherent uncertainty), and (3) the Young's …


Understanding Svocs, Ying Xu, Jianshun Zhang Dec 2011

Understanding Svocs, Ying Xu, Jianshun Zhang

Mechanical and Aerospace Engineering - All Scholarship

Semi-volatile organic compounds (SVOCs) are an important class of indoor pollutants that are of great health concern. However, they have not received much attention within the ASHRAE community. This column provides an overview of the sources, sinks, transport mechanisms, and potential health effects, and discusses how HVAC systems may affect occupants’ exposure to SVOCs.


Dynamic Botanical Filtration System For Indoor Air Purification, Zhiqiang Wang Dec 2011

Dynamic Botanical Filtration System For Indoor Air Purification, Zhiqiang Wang

Mechanical and Aerospace Engineering - Dissertations

A dynamic botanical air filtration (DBAF) system was developed, tested and modeled for indoor air purification. The DBAF system consisted of an activated-carbon/hydroculture-based root bed for potted-plant, a fan for driving air through the root bed for purification, and an irrigation system for maintaining proper moisture content in the root bed. Results from test conducted in a full-scale open office space indicated that the filtration system had ability to supply clean air equivalent to 80% of required outdoor air supply for the space. The DBAF was effective for removing both formaldehyde and toluene at 5 to 32% volumetric water content …


Wireless Solar-Powered Thermal Imaging Camera, Andy Bonk, Billy Mcvicker, Jacob Richardson Dec 2011

Wireless Solar-Powered Thermal Imaging Camera, Andy Bonk, Billy Mcvicker, Jacob Richardson

Mechanical Engineering

Creation of a mounted wireless self-powered thermal imaging camera system.


Robotic Turret, Daniel Romero, Matthew (Matt) Martelle, Scott Mullens, Rachel Diamant Dec 2011

Robotic Turret, Daniel Romero, Matthew (Matt) Martelle, Scott Mullens, Rachel Diamant

Mechanical Engineering

No abstract provided.


Ergonomic Lifter, Bejan Brian Banihashemi, Dylan James Schockemoehl, Andrew Ouellet Dec 2011

Ergonomic Lifter, Bejan Brian Banihashemi, Dylan James Schockemoehl, Andrew Ouellet

Mechanical Engineering

No abstract provided.


Wiihopp, Jeff Christian, Ben Hoselton, Derek Simon Dec 2011

Wiihopp, Jeff Christian, Ben Hoselton, Derek Simon

Mechanical Engineering

Childhood obesity is becoming a growing problem in the United States. According to the CDC, childhood obesity has more than tripled in the past 30 years [7]. It can lead to health problems previously reserved for adults, such as diabetes, high blood pressure, and high cholesterol. For the team WiiHopp project, we plan to turn a JumpSport mini-trampoline into a controller for the Nintendo Wii console. The hope is to help turn the problem of video games and the laziness surrounding them into an active solution to combat the problem of childhood obesity.

Our goal is to produce an add-on …


Access|Closure Balloon Catheter Redesign Project, Keenan Bamburg, Yvette Castillo, Elizabeth Eskildsen Dec 2011

Access|Closure Balloon Catheter Redesign Project, Keenan Bamburg, Yvette Castillo, Elizabeth Eskildsen

Mechanical Engineering

No abstract provided.


Strider, George Cummings, Brian Kreidle, Ricky Lee, Clark Steen Dec 2011

Strider, George Cummings, Brian Kreidle, Ricky Lee, Clark Steen

Mechanical Engineering

No abstract provided.


Fenestration Studies On Building Energy Using The Facade Evaluation Facility, Wendell Cocina Dec 2011

Fenestration Studies On Building Energy Using The Facade Evaluation Facility, Wendell Cocina

UNLV Theses, Dissertations, Professional Papers, and Capstones

The project was developed to assess several types of facades and their influence on building energy, mainly focused on windows and other building fenestrations. Requirements for the facility are stated in this paper alongside corresponding solutions. The facility is designed to represent a section of a building façade. Experimenting on a wide range of fenestrations including windows with integrated PV elements was the primary prerequisite. The option of removable façade configurations was used and allowed testing specimens to be changed effortlessly. Instrumentation and data acquisition are discussed including calibration and uncertainty analysis. Investigation of the air conditioning unit was concluded …


Investigation On Interactions Of Unsteady Wakes And Film Cooling On An Annular Endwall, Matthew J. Golsen Dec 2011

Investigation On Interactions Of Unsteady Wakes And Film Cooling On An Annular Endwall, Matthew J. Golsen

HIM 1990-2015

In recent decades, greater interest in the effect of rotational wakes on gas turbine film cooling applications has produced increasing numbers of studies on these unsteady phenomena. Wakes are primarily shed from upstream components such as transition duct walls, stator vanes, and rotors. Studies have shown that in areas of unsteady flow, the best performing parameters in conventional steady investigations may not be the best for unsteady applications. One common method of modeling the unsteady wake interaction in subsonic flows is the use of spoke wheel type wake generators using cylindrical rods to produce the velocity detriment and local increase …


Historic Calculator Project, Will Harris, Dan Marioni, Kevin Webb, Chad Williams Dec 2011

Historic Calculator Project, Will Harris, Dan Marioni, Kevin Webb, Chad Williams

Mechanical Engineering

The Deutsches Museum of Munich, Germany requested add-on components to their mechanical calculator exhibit. The end-goal is to produce an interactive 3D model in software to demonstrate the functions of the Braun-Vayringe Machine (BVM). There will be four students working on this project at California Polytechnic State University, San Luis Obispo: two mechanical engineers (Dan Marioni and Will Harris) and two computer engineers (Chad Williams and Kevin Webb).This project involves the coordination of three facilities; the Deutsches Museum, and the Mechanical and Computer Science Departments of Cal Poly. The name of the project is known as the Historic Calculator Project …


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

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

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


High Temperature Thermodynamic Properties Of Znte(S), Robert F. Brebrick Dec 2011

High Temperature Thermodynamic Properties Of Znte(S), Robert F. Brebrick

Mechanical Engineering Faculty Research and Publications

We have gathered the partial pressure, Knudsen cell, and emf measurements on ZnTe(s) from which the Gibbs energy of formation can be calculated. Published partial pressures of diatomic tellurium have been adjusted to take account of a subsequently published third law analysis of tellurium. The equation used to calculate the total pressure from the rate of mass loss from an extensive set of Knudsen cell measurements has been corrected to give a 5% increase in total pressure and the Gibbs energy of formation has been recalculated. A high temperature heat capacity for ZnTe(s) has been selected from the published data. …


The Role Of Thermally-Induced Geometrical Changes In Temperature Trending Of Railroad Tapered Roller Bearings, Andrei G. Vaipan Dec 2011

The Role Of Thermally-Induced Geometrical Changes In Temperature Trending Of Railroad Tapered Roller Bearings, Andrei G. Vaipan

Theses and Dissertations - UTB/UTPA

The understanding of the phenomenon of temperature trending of railroad tapered roller bearings is of paramount importance to the railroad industry. The problem that this poses to the industry is that it leads to false alarms triggered by wayside detectors, which forces the premature removal of defect-free bearings. This thesis provides more insight into this phenomenon and answers questions regarding the importance of key tapered roller bearing components geometry and geometrical changes during temperature trending events. In this study, dynamic experiments conducted in the laboratory have represented the primary method of testing bearing temperature trending. The experimental results are brought …


Analysis And Design Of An Anisotropic, Compliant Suspension Component, Samantha Jean Salinas Dec 2011

Analysis And Design Of An Anisotropic, Compliant Suspension Component, Samantha Jean Salinas

Theses and Dissertations - UTB/UTPA

A steering pad on a train is meant to reduce the force on the wheel while moving along a curve in the rail. A new steering pad was desired with properties tuned for a new suspension system design. An anisotropic, compliant pad was designed for a specific stiffness anisotropy, 20:1. Finite element analysis was performed on various models as a guide to designing a pin with the desired stiffness ratio. A design was chosen for a prototype made of thermoset polyurethane, a similar material to that currently used. Experiments were performed on the prototype pad model to determine vertical and …


Linear Electromagnetic Energy Scavenging Device Designed In Low Temperature Co-Fired Ceramics, Hope A. Bateman Dec 2011

Linear Electromagnetic Energy Scavenging Device Designed In Low Temperature Co-Fired Ceramics, Hope A. Bateman

Boise State University Theses and Dissertations

For a soldier deployed in a remote location on the earth or a recreational hiker in the wilderness or a wild land firefighter battling a destructive wildfire, access to a power source is problematic. Local and regional communication systems, navigation, lights, imaging: all of these require a power source. For short time periods, batteries may be sufficient but with extended time periods the weight of the batteries and cost of replacement becomes a problem. Energy scavenging devices could fill this need and be used as a secondary power source when solar or batteries are not available.

A linear electromagnetic generator …


Modeling And Control Of A Flexible Ionic Polymer Metal Composite(Ipmc) Actuator For Underwater Propulsion, Shivakanth Gutta Dec 2011

Modeling And Control Of A Flexible Ionic Polymer Metal Composite(Ipmc) Actuator For Underwater Propulsion, Shivakanth Gutta

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this research is to model and control the underwater vehicle propelled by IPMC actuator. IPMC consists of an ionic membrane sandwiched between two metallic electrodes. When an external voltage is applied, IPMC undergoes large deformation due to transport of ions. Due to its ability to work in aqueous environments, it can be used for developing small scale underwater vehicles.

First, Finite element approach is used to describe the dynamics of the both single and segmented IPMC actuator. In the approach presented, each element is attached with a local coordinate system that undergoes rigid body motion along with …


A Study Of A Novel Modular Variable Geometry Frame Arranged As A Robotic Surface, Christopher James Salisbury Dec 2011

A Study Of A Novel Modular Variable Geometry Frame Arranged As A Robotic Surface, Christopher James Salisbury

UNLV Theses, Dissertations, Professional Papers, and Capstones

The novel concept of a "variable geometry frame" is introduced and explored through a three-dimensional robotic surface which is devised and implemented using triangular modules. The link design is optimized using surplus motor dimensions as firm constraints, and round numbers for further arbitrary constraints. Each module is connected by a passive six-bar mechanism that mimics the constraints of a spherical joint at each triangle intersection. A three dimensional inkjet printer is used to create a six-module prototype designed around surplus stepper motors powered by an old computer power supply as a proof-of-concept example.

The finite element method is applied to …


Energy-Based Analysis Of Utility Scale Hybrid Power Systems, Kwame Agyenim-Boateng Dec 2011

Energy-Based Analysis Of Utility Scale Hybrid Power Systems, Kwame Agyenim-Boateng

UNLV Theses, Dissertations, Professional Papers, and Capstones

The promise of large-scale use of renewables such as wind and solar for supplying electrical power is tempered by the sources' transient behavior and the impact this would have on the operation of the grid. Among the methods cited for addressing some of those concerns are exploring the complementary nature of solar and wind power generation, and through the use of supplemental energy storage. While the technology for the latter has not been proven to be economical on a large scale at the present time, some assessments of what magnitude is required can be made. An energy-based analysis of utility …


Quantification Of Stochastic Uncertainty Propagation For Monte Carlo Depletion Methods In Reactor Analysis, Quentin Thomas Newell Dec 2011

Quantification Of Stochastic Uncertainty Propagation For Monte Carlo Depletion Methods In Reactor Analysis, Quentin Thomas Newell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Monte Carlo method provides powerful geometric modeling capabilities for large problem domains in 3-D; therefore, the Monte Carlo method is becoming popular for 3-D fuel depletion analyses to compute quantities of interest in spent nuclear fuel including isotopic compositions. The Monte Carlo approach has not been fully embraced due to unresolved issues concerning the effect of Monte Carlo uncertainties on the predicted results.

Use of the Monte Carlo method to solve the neutron transport equation introduces stochastic uncertainty in the computed fluxes. These fluxes are used to collapse cross sections, estimate power distributions, and deplete the fuel within depletion …