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2012

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Articles 1 - 30 of 308

Full-Text Articles in Mechanical Engineering

Separation Control On High Lift Low-Pressure Turbine Airfoils Using Pulsed Vortex Generator Jets, Ralph J. Volino, Mounir B. Ibrahim Dec 2012

Separation Control On High Lift Low-Pressure Turbine Airfoils Using Pulsed Vortex Generator Jets, Ralph J. Volino, Mounir B. Ibrahim

Mechanical Engineering Faculty Publications

Boundary layer separation control has been studied using vortex generator jets (VGJs) on a very high lift, low-pressure turbine airfoil. Experiments were done under low (0.6%) freestream turbulence conditions on a linear cascade in a low speed wind tunnel. Pressure surveys on the airfoil surface and downstream total pressure loss surveys were documented. Instantaneous velocity profile measurements were acquired in the suction surface boundary layer. Cases were considered at Reynolds numbers (based on the suction surface length and the nominal exit velocity from the cascade) of 25000 and 50000. Jet pulsing frequency and duty cycle were varied. In cases ...


Comparison Of 4d Phase-Contrast Mri Flow Measurements To Computational Fluid Dynamics Simulations Of Cerebrospinal Fluid Motion In The Cervical Spine, Theresia Yiallourou, Jan Robert Kroger, Nikolaos Stergiopulos, David Maintz, Bryn A. Martin, Alexander C. Bunck Dec 2012

Comparison Of 4d Phase-Contrast Mri Flow Measurements To Computational Fluid Dynamics Simulations Of Cerebrospinal Fluid Motion In The Cervical Spine, Theresia Yiallourou, Jan Robert Kroger, Nikolaos Stergiopulos, David Maintz, Bryn A. Martin, Alexander C. Bunck

Mechanical Engineering Faculty Research

Cerebrospinal fluid (CSF) dynamics in the cervical spinal subarachnoid space (SSS) have been thought to be important to help diagnose and assess craniospinal disorders such as Chiari I malformation (CM). In this study we obtained time-resolved three directional velocity encoded phase-contrast MRI (4D PC MRI) in three healthy volunteers and four CM patients and compared the 4D PC MRI measurements to subject-specific 3D computational fluid dynamics (CFD) simulations. The CFD simulations considered the geometry to be rigid-walled and did not include small anatomical structures such as nerve roots, denticulate ligaments and arachnoid trabeculae. Results were compared at nine axial planes ...


Stress And Strain Adaptation In Load-Dependent Remodeling Of The Embryonic Left Ventricle, Christine Buffinton Dec 2012

Stress And Strain Adaptation In Load-Dependent Remodeling Of The Embryonic Left Ventricle, Christine Buffinton

Faculty Journal Articles

Altered pressure in the developing left ventricle (LV) results in altered morphology and tissue material properties. Mechanical stress and strain may play a role in the regulating process. This study showed that confocal microscopy, three-dimensional reconstruction, and finite element analysis can provide a detailed model of stress and strain in the trabeculated embryonic heart. The method was used to test the hypothesis that end-diastolic strains are normalized after altered loading of the LV during the stages of trabecular compaction and chamber formation. Stage-29 chick LVs subjected to pressure overload and underload at stage 21 were reconstructed with full trabecular morphology ...


High Performance Low Temperature Solid Oxide Fuel Cells With Novel Electrode Architecture, Yu Chen, Qian Liu, Zhibin Yang, Fanglin Chen, Minfang Han Dec 2012

High Performance Low Temperature Solid Oxide Fuel Cells With Novel Electrode Architecture, Yu Chen, Qian Liu, Zhibin Yang, Fanglin Chen, Minfang Han

Faculty Publications

In this study, we have fabricated high performance low temperature solid oxide fuel cells (LT-SOFCs) with both acicular anodes and cathodes with thin Gd-doped ceria (GDC) electrolyte film. The acicular Ni-Gd0.1Ce0.9O2−δ (Ni-GDC) anode was prepared using freeze drying tape casting, while the hierarchically porous cathode with nano-size Sm0.5Sr0.5CoO3 (SSC) particles covering an acicular GDC skeleton was prepared by a combination of freeze drying tape casting and self-rising approaches. The acicular electrodes with 5–200 μm pores/channels enhance mass transport, while SSC particles of about ...


A Building Energy Efficiency Optimization Method By Evaluating The Effective Thermal Zones Occupancy, Anna Laura Pisello, Michael Bobker, Franco Cotana Dec 2012

A Building Energy Efficiency Optimization Method By Evaluating The Effective Thermal Zones Occupancy, Anna Laura Pisello, Michael Bobker, Franco Cotana

Publications and Research

Building energy efficiency is strongly linked to the operations and control systems, together with the integrated performance of passive and active systems. In new high quality buildings in particular, where these two latter aspects have been already implemented at the design stage, users’ perspective, obtained through post-occupancy assessment, has to be considered to reduce whole energy requirement during service life. This research presents an innovative and low-cost methodology to reduce buildings’ energy requirements through post-occupancy assessment and optimization of energy operations using effective users’ attitudes and requirements as feedback. As a meaningful example, the proposed method is applied to a ...


Coarse-Graining Approach To Infer Mesoscale Interaction Potentials From Atomistic Interactions For Aggregating Systems, Sergiy Markutsya, Rodney O. Fox, Shankar Subramaniam Dec 2012

Coarse-Graining Approach To Infer Mesoscale Interaction Potentials From Atomistic Interactions For Aggregating Systems, Sergiy Markutsya, Rodney O. Fox, Shankar Subramaniam

Mechanical Engineering Publications

A coarse-graining (CG) approach is developed to infer mesoscale interaction potentials in aggregating systems, resulting in an improved potential of mean force for Langevin dynamics (LD) and Brownian dynamics (BD) simulations. Starting from the evolution equation for the solute pair correlation function, this semi-analytical CG approach identifies accurate modeling of the relative acceleration between solute particles in a solvent bath as a reliable route to predicting the time-evolving structural properties of nonequilibrium aggregating systems. Noting that the solute–solvent pair correlation function attains a steady state rapidly as compared to characteristic aggregation time scales, this CG approach derives the effective ...


College Of Engineering Senior Design Competition Fall 2012, University Of Nevada, Las Vegas Dec 2012

College Of Engineering Senior Design Competition Fall 2012, University Of Nevada, Las Vegas

Senior Projects (COE)

Senior Design Experience

Part of every UNLV engineering student's academic experience, the Senior Design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. Working in teams, the senior design project encourages students to use everything learned in the engineering and computer design programs to create a practical, real world solution to an engineering challenge.

Beyond the classroom ...

Because of the requirement to work in teams, students also build good communication skills, presentation skills and even business writing skills. They also have to ...


Integrating Qplm And Biomedical Test Data With An Anisotropic Fiber Distribution Model And Predictions Of Tgf-Β1 And Igf-1 Regulation Of Articular Cartilage Fiber Modulus, Michael E. Stender, Christopher B. Raub, Kevin A. Yamauchi, Reza Shirazi, Pasquale Vena, Robert L. Sah, Scott J. Hazelwood, Stephen M. Klisch Dec 2012

Integrating Qplm And Biomedical Test Data With An Anisotropic Fiber Distribution Model And Predictions Of Tgf-Β1 And Igf-1 Regulation Of Articular Cartilage Fiber Modulus, Michael E. Stender, Christopher B. Raub, Kevin A. Yamauchi, Reza Shirazi, Pasquale Vena, Robert L. Sah, Scott J. Hazelwood, Stephen M. Klisch

Mechanical Engineering

A continuum mixture model with distinct collagen (COL) and glycosaminoglycan elastic constituents was developed for the solid matrix of immature bovine articular cartilage. A continuous COL fiber volume fraction distribution function and a true COL fiber elastic modulus ( Ef) were used. Quantitative polarized light microscopy (qPLM) methods were developed to account for the relatively high cell density of immature articular cartilage and used with a novel algorithm that constructs a 3D distribution function from 2D qPLM data. For specimens untreated and cultured in vitro, most model parameters were specified from qPLM analysis and biochemical assay results; consequently, Ef was predicted ...


Enskog Kinetic Theory For Monodisperse Gas–Solid Flows, V. Garzó, Sudheer Tenneti, Shankar Subramaniam, C. M. Hrenya Dec 2012

Enskog Kinetic Theory For Monodisperse Gas–Solid Flows, V. Garzó, Sudheer Tenneti, Shankar Subramaniam, C. M. Hrenya

Mechanical Engineering Publications

The Enskog kinetic theory is used as a starting point to model a suspension of solid particles in a viscous gas. Unlike previous efforts for similar suspensions, the gas-phase contribution to the instantaneous particle acceleration appearing in the Enskog equation is modelled using a Langevin equation, which can be applied to a wide parameter space (e.g. high Reynolds number). Attention here is limited to low Reynolds number flow, however, in order to assess the influence of the gas phase on the constitutive relations, which was assumed to be negligible in a previous analytical treatment. The Chapman–Enskog method is ...


Rotor Model Updating And Validation For An Active Magnetic Bearing Based High-Speed Machining Spindle, Adam C. Wroblewski, Jerzy T. Sawicki, Alexander H. Pesch Dec 2012

Rotor Model Updating And Validation For An Active Magnetic Bearing Based High-Speed Machining Spindle, Adam C. Wroblewski, Jerzy T. Sawicki, Alexander H. Pesch

Mechanical Engineering Faculty Publications

This paper presents an experimentally driven model updating approach to address the dynamic inaccuracy of the nominal finite element (FE) rotor model of a machining spindle supported on active magnetic bearings. Modeling error is minimized through the application of a numerical optimization algorithm to adjust appropriately selected FE model parameters. Minimizing the error of both resonance and antiresonance frequencies simultaneously accounts for rotor natural frequencies as well as for their mode shapes. Antiresonance frequencies, which are shown to heavily influence the model’s dynamic properties, are commonly disregarded in structural modeling. Evaluation of the updated rotor model is performed through ...


An Investigation Into Using Magnetically Attached Piezoelectric Elements For Vibration Control, J. C. Collinger, W. C. Messner, Jonathan A. Wickert Dec 2012

An Investigation Into Using Magnetically Attached Piezoelectric Elements For Vibration Control, J. C. Collinger, W. C. Messner, Jonathan A. Wickert

Mechanical Engineering Publications

A novel vibration control method utilizing magnetically mounted piezoelectric elements is described. Piezoelectric elements are bonded to permanent magnets, termed here as control mounts, which are attached to the surface of a steel beam through their magnetic attraction. The magnetic-piezoelectric control mounts are an alternative to traditional epoxy attachment methods for piezoelectric elements which allows for easy in-the-field reconfiguration. In model and laboratory measurements, the beam is driven through base excitation and the resonant shunt technique is utilized to demonstrate the attenuation characteristics of two magnetic-piezoelectric control mounts. The coupled system is discretized using a Galerkin finite element model that ...


Sustainability For Die Manufacturing: Comparative Study Of Wedm And Milling, Matthew S. Kalus Dec 2012

Sustainability For Die Manufacturing: Comparative Study Of Wedm And Milling, Matthew S. Kalus

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

Sustainability is more important in today's culture due to the increasing demand for a more eco-friendly society. Concentrations in minimizing and reducing environmental impacts, energy and natural resources have been forthcoming in industry. The tool, mold and die industries are the most well known industries that machine harder materials using mills and WEDM. The objective of this thesis was to compare the sustainability differences in both of these machines utilizing the accepted standards for evaluating the manufacturing process performance for sustainability. These standards include the evaluation of the process parameters, raw materials, power, tools and fluids which all contribute ...


A Study Of Hdpe In High Pressure Of Hydrogen Gas—Measurement Of Permeation Parameters And Fracture Criteria, Sompong Prachumchon Dec 2012

A Study Of Hdpe In High Pressure Of Hydrogen Gas—Measurement Of Permeation Parameters And Fracture Criteria, Sompong Prachumchon

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

The permeation parameters of hydrogen gas in high density polyethylene (HDPE) system are sought by comparison with a diffusion model. The method of Green’s functions is used to obtain solutions for the diffusion model. Permeation parameters are found from transient experimented data during two processes; pressurization followed by depressurization. The mechanical compression of HDPE during the pressurization process resulted in lower diffusivity coefficient values and higher solubility values. The results show that the diffusivity coefficient value in the pressurization process is 37% of that during the depressurization process. At the start of the depressurization process, a short-duration fast flow ...


Energy Trapping Of Thickness-Shear And Thickness-Twist Modes In A Partially Electroded At-Cut Quartz Resonator, Huijing He, Guoquan Nie, Jinxi Liu, Jiashi Yang Dec 2012

Energy Trapping Of Thickness-Shear And Thickness-Twist Modes In A Partially Electroded At-Cut Quartz Resonator, Huijing He, Guoquan Nie, Jinxi Liu, Jiashi Yang

Mechanical & Materials Engineering Faculty Publications

The thickness-shear and thickness-twist vibrations of a finite and partially electroded AT-cut quartz resonator are investigated. The equations of anisotropic elasticity are used with the omission of the small elastic constant c56 . An analytical solution is obtained using Fourier series from which the free vibration resonant frequencies, mode shapes, and energy trapping are calculated and examined.


Implementation Of Magnetic Resonance Elastography For The Investigation Of Traumatic Brain Injuries, Thomas Boulet Dec 2012

Implementation Of Magnetic Resonance Elastography For The Investigation Of Traumatic Brain Injuries, Thomas Boulet

Engineering Mechanics Dissertations & Theses

Magnetic resonance elastography (MRE) is a potentially transformative imaging modality allowing local and non-invasive measurement of biological tissue mechanical properties. It uses a specific phase contrast MR pulse sequence to measure induced vibratory motion in soft material, from which material properties can be estimated. Compared to other imaging techniques, MRE is able to detect tissue pathology at early stages by quantifying the changes in tissue stiffness associated with diseases. In an effort to develop the technique and improve its capabilities, two inversion algorithms were written to evaluate viscoelastic properties from the measured displacements fields. The first one was based on ...


Modular Joystick Design For Virtual Reality Surgical Skills Training, Michael Head Nov 2012

Modular Joystick Design For Virtual Reality Surgical Skills Training, Michael Head

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

A modular control interface and simulated virtual reality environment was designed and created in order to determine how the kinematic architecture of a control interface affects minimally invasive surgery. A user is able to selectively determine how many, the type, and location of degrees of freedom they require for the specific surgical simulation through the use of modular joints and constraint components. Furthermore, passive locking was designed and implemented through the use of inflated latex tubing around rotational degree of freedom joints. It is believed these features will have the ability to effectively simulate a variety of surgical simulations and ...


Predicting Vehicle Dynamics For Roadside Safety Using Multibody Systems Simulations, Brett D. Schlueter Nov 2012

Predicting Vehicle Dynamics For Roadside Safety Using Multibody Systems Simulations, Brett D. Schlueter

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

Accurate means for predicting vehicle dynamics is required in the design and testing of roadside safety hardware. Past research has used finite element (FE) modeling to this end, but multibody systems (MBS) modeling may provide a more efficient way to solve these problems. MBS modeling using Adams/Car was investigated by first compiling an introduction to the program, then performing basic vehicle dynamics simulations using a supplied model. Next, a model of a 2270 kg pickup was created and validated against physical test data involving impact with a speed bump. Finally, pickup trajectories in 4H:1V and 6H:1V V-ditches ...


Cable Median Barrier Failure Analysis And Remediation, Cody S. Stolle Nov 2012

Cable Median Barrier Failure Analysis And Remediation, Cody S. Stolle

Civil and Environmental Engineering Theses, Dissertations, and Student Research

On divided roadways, cross-median fatalities are disproportionately overrepresented in fatal and serious injury crashes. Many state DOTs sought to mitigate cross-median crash risk by installing cable median barriers. Despite increased crash rates, studies evaluating crash rates before and after cable median barriers were installed indicated excellent improvement in overall safety.

Although cable median barriers are intended to prevent serious cross-median crashes, cable barriers can also contribute to serious injury and fatality crashes which would not have otherwise occurred, including penetration and rollover crashes. In order to reduce the frequency of undesirable penetration and rollover crashes occurring with cable median barriers ...


A Model For Emission Yield From Planar Photocathodes Based On Photon-Enhanced Thermionic Emission Or Negative-Electron-Affinity Photoemission, Kunal Sahasrabuddhe, Jared W. Schwede, Igor Bargatin, Joel Jean, Roger T. Howe, Zhi-Xun Shen, Nicholas A. Melosh Nov 2012

A Model For Emission Yield From Planar Photocathodes Based On Photon-Enhanced Thermionic Emission Or Negative-Electron-Affinity Photoemission, Kunal Sahasrabuddhe, Jared W. Schwede, Igor Bargatin, Joel Jean, Roger T. Howe, Zhi-Xun Shen, Nicholas A. Melosh

Departmental Papers (MEAM)

A general model is presented for electron emission yield from planar photocathodes that accounts for arbitrary cathode thickness and finite recombination velocities at both front and back surfaces. This treatment is applicable to negative electron affinity emitters as well as positive electron affinity cathodes, which have been predicted to be useful for energy conversion. The emission model is based on a simple one-dimensional steady-state diffusion treatment. The resulting relation for electron yield is used to model emission from thin-film cathodes with material parameters similar to GaAs. Cathode thickness and recombination at the emissive surface are found to strongly affect emission ...


Can Silver Be A Reliable Current Collector For Electrochemical Tests?, Yunhui Gong, Changyong Qin, Kevin Huang Nov 2012

Can Silver Be A Reliable Current Collector For Electrochemical Tests?, Yunhui Gong, Changyong Qin, Kevin Huang

Faculty Publications

The true functionality of a current collector employed in electrochemical cells is to ensure a low- resistance steady electrons flow between the cell and instrumentation without involving in any local electrochemical reactions of the electrode. In this study, we investigated the effect of curing temperature of a common current collector, silver, on the polarization area specific resistance (ASR) of a cathode. The results explicitly showed that at least one order of magnitude lower ASR for a cathode with Ag cured at 800°C than that cured at 650°C of the same cathode configuration. Microscopic analysis of the 800°C-cured ...


Fourier Transform Profilometry Using A Binary Area Modulation Technique, William F. Lohry, Song Zhang Nov 2012

Fourier Transform Profilometry Using A Binary Area Modulation Technique, William F. Lohry, Song Zhang

Mechanical Engineering Publications

A recent study found that it is very difficult to use the squared binary defocusing technique to eliminate the influence of third-order harmonics without compromising fringe quality, and thus it is challenging to utilize Fourier transform profilometry to achieve high-quality three-dimensional measurement. A novel approach is presented to effectively eliminate the third-order harmonics by modulating the squared binary structured patterns. Both simulation and experiments are presented to verify the performance of the proposed technique.


Experimental Studies And Dynamics Modeling Analysis Of The Swimming And Diving Of Whirligig Beetles (Coleoptera: Gyrinidae), Zhonghua Xu, Scott C. Lenaghan, Benjamin E. Reese, Xinghua Jia, Mingjun Zhang Nov 2012

Experimental Studies And Dynamics Modeling Analysis Of The Swimming And Diving Of Whirligig Beetles (Coleoptera: Gyrinidae), Zhonghua Xu, Scott C. Lenaghan, Benjamin E. Reese, Xinghua Jia, Mingjun Zhang

Faculty Publications and Other Works -- Mechanical, Aerospace and Biomedical Engineering

Whirligig beetles (Coleoptera, Gyrinidae) can fly through the air, swiftly swim on the surface of water, and quickly dive across the air-water interface. The propulsive efficiency of the species is believed to be one of the highest measured for a thrust generating apparatus within the animal kingdom. The goals of this research were to understand the distinctive biological mechanisms that allow the beetles to swim and dive, while searching for potential bio-inspired robotics applications. Through static and dynamic measurements obtained using a combination of microscopy and high-speed imaging, parameters associated with the morphology and beating kinematics of the whirligig beetle ...


The Car And The Cloud: Automotive Architectures For 2020, Rahul Mangharam Nov 2012

The Car And The Cloud: Automotive Architectures For 2020, Rahul Mangharam

Real-Time and Embedded Systems Lab (mLAB)

Three trends are emerging in drivers’ expectations for their vehicle: (1) continuous connectivity with both the infrastructure (e.g., smart traffic intersections) and other commuters, (2) enhanced levels of productivity and entertainment for the duration of travel, and (3) reduction in cognitive load through semiautonomous operation and automated congestion-aware route planning. To address these demands, vehicles should become more programmable so that almost every aspect of engine control, cabin comfort, connectivity, navigation, and safety will be remotely upgradable and designed to evolve over the lifetime of the vehicle.

Progress toward the vehicle of the future will entail new approaches in ...


A Microfluidic Reactor For Energy Applications, Luke T. Wagner, Jie Yang, Susan Ghobadian, Reza Montazami, Nicole N. Hashemi Nov 2012

A Microfluidic Reactor For Energy Applications, Luke T. Wagner, Jie Yang, Susan Ghobadian, Reza Montazami, Nicole N. Hashemi

Mechanical Engineering Publications

Miniature microbial fuel cells have recently drawn lots of attention as portable power generation devices due to their short startup time and environmentally-friendly process which could be used for powering small integrated biosensors. We designed and fabricated a microbial fuel cell in a microfluidic platform. The device was made in polydimethylsiloxane with a volume of 4 μL and consisted of two carbon cloth electrodes and proton exchange membrane. Shewanella Oneidensis MR-1 was chosen to be the electrogenic bacterial strain and inoculated into the anode chamber. Ferricyanide was used as the catholyte and pumped into the cathode chamber at a constant ...


Chemical Vapor-Deposited Carbon Nanofibers On Carbon Fabric For Supercapacitor Electrode Applications, Yang Gao, Gaind P. Pandey, James Turner, Charles R. Westgate, Bahgat Sammakia Nov 2012

Chemical Vapor-Deposited Carbon Nanofibers On Carbon Fabric For Supercapacitor Electrode Applications, Yang Gao, Gaind P. Pandey, James Turner, Charles R. Westgate, Bahgat Sammakia

Mechanical Engineering Faculty Scholarship

Entangled carbon nanofibers (CNFs) were synthesized on a flexible carbon fabric (CF) via water-assisted chemical vapor deposition at 800A degrees C at atmospheric pressure utilizing iron (Fe) nanoparticles as catalysts, ethylene (C2H4) as the precursor gas, and argon (Ar) and hydrogen (H-2) as the carrier gases. Scanning electron microscopy, transmission electron microscopy, and electron dispersive spectroscopy were employed to characterize the morphology and structure of the CNFs. It has been found that the catalyst (Fe) thickness affected the morphology of the CNFs on the CF, resulting in different capacitive behaviors of the CNF/CF electrodes. Two different Fe thicknesses (5 ...


An Rna Aptamer-Based Microcantilever Sensor To Detect The Inflammatory Marker, Mouse Lipocalin-2, Lijie Zhai, Tianjiao Wang, Kyungho Kang, Yue Zhao, Pranav Shrotriya, Marit Nilsen-Hamilton Oct 2012

An Rna Aptamer-Based Microcantilever Sensor To Detect The Inflammatory Marker, Mouse Lipocalin-2, Lijie Zhai, Tianjiao Wang, Kyungho Kang, Yue Zhao, Pranav Shrotriya, Marit Nilsen-Hamilton

Mechanical Engineering Publications

Lipocalin-2 (Lcn2) is a biomarker for many inflammatory-based diseases, including acute kidney injury, cardiovascular stress, diabetes, and various cancers. Inflammatory transitions occur rapidly in kidney and cardiovascular disease, for which an in-line monitor could be beneficial. Microcantilever devices with aptamers as recognition elements can be effective and rapidly responsive sensors. Here, we have selected and characterized an RNA aptamer that specifically binds mouse Lcn2 (mLcn2) with a dissociation constant of 340 ± 70 nM in solution and 38 ± 22 nM when immobilized on a surface. The higher apparent affinity of the immobilized aptamer may result from its effective multivalency that decreases ...


Advanced Phase-Field Approach To Dislocation Evolution, Valery I. Levitas, Mahdi Javanbakht Oct 2012

Advanced Phase-Field Approach To Dislocation Evolution, Valery I. Levitas, Mahdi Javanbakht

Aerospace Engineering Publications

The phase-field approach to dislocations is conceptually advanced. Large strain formulation is developed. A local thermodynamic potential eliminates stress dependence of the Burgers vector and reproduces the desired local stress-strain curve, as well as the desired, mesh-independent, dislocation height for any dislocation orientation. A gradient energy contains an additional term, which excludes localization of dislocation within a height smaller than the prescribed height but does not produce artificial interface energy and dislocation widening. Problems for nucleation and evolution of multiple dislocations along the single and multiple slip systems, and the interaction of dislocations with an austenite (A)-martensite (M) interface ...


Work In Progress: Outreach Assessment: Measuring Engagement, Lizabeth Schlemer, John Oliver, Katherine Chen, Sophia Rodriguez Mata, Eric Kim Oct 2012

Work In Progress: Outreach Assessment: Measuring Engagement, Lizabeth Schlemer, John Oliver, Katherine Chen, Sophia Rodriguez Mata, Eric Kim

Industrial and Manufacturing Engineering

The Learn By Doing Lab (LBDL) at Cal Poly, San Luis Obispo is an on-campus laboratory where 5th through 8th grade students are taught by undergraduates who may be planning a careers in teaching. The two populations - elementary students and undergraduates - are equally important in the process. Since 2008, the lab has seen over 4000 elementary and junior high students and over 100 undergrads have participated. In most outreach assessment the number of individuals participating is an important metric, but this last Spring we experimented with a more in depth measure of effectiveness. As in any learning experience engagement in ...


Designing For Success: Developing Engineers Who Consider Universal Design Principles, Kimberly Edginton Bigelow Oct 2012

Designing For Success: Developing Engineers Who Consider Universal Design Principles, Kimberly Edginton Bigelow

Mechanical and Aerospace Engineering Faculty Publications

Engineers must design for a diverse group of potential users of their products; however, engineering curricula rarely include an emphasis on universal design principles. This research article details the effectiveness of a design project implemented in a first-year engineering course in an effort to raise awareness of the need for engineers to be more inclusive when designing. Students were asked to apply universal design principles to redesign an engineering laboratory to make it more usable to all, including individuals with disabilities who use the room. A representative from the university’s disability services staff, as well as individuals with first-hand ...


Electrochemical And Metal-Phase Processes Accompanying Hydrogen Absorption In Aluminum During Aqueous Corrosion, Kurt R. Hebert, Ömer Ö. Çapraz, Pranav Shrotriya, Guiping Zhang Oct 2012

Electrochemical And Metal-Phase Processes Accompanying Hydrogen Absorption In Aluminum During Aqueous Corrosion, Kurt R. Hebert, Ömer Ö. Çapraz, Pranav Shrotriya, Guiping Zhang

Mechanical Engineering Conference Presentations, Papers, and Proceedings

Alkaline corrosion of aluminum results in large supersaturations of hydrogen, and formation of hydride and subsurface voids.1-4 Aluminum itself is not susceptible to stress corrosion cracking (SCC), but hydrogen and hydride effects are significant for SCC mechanisms on Al and Mg alloys. Chu found evidence that corrosion-induced tensile stress in several alloys additively combines with external tensile stress to promote SCC, and attributed the former to lattice contraction associated with vacancies injected during corrosion.5 Evidence for vacancy injection on Al was found from X-ray diffraction and in situ curvature measurements on Al thin films undergoing corrosion.1,6 ...