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Role Of Grain Boundary Character Distribution On Dynamic Recrystallization Using Monte Carlo Simulations, Jared Stein, Megan Frary 2010 Boise State University

Role Of Grain Boundary Character Distribution On Dynamic Recrystallization Using Monte Carlo Simulations, Jared Stein, Megan Frary

Megan Frary

Monte Carlo simulations are commonly applied to study microstructural evolution, including abnormal grain growth and recrystallization. Here, Monte Carlo simulations are used to study the effects of grain boundary character distribution on dynamic recrystallization. The initial stored energy is uniformly distributed and a constant strain rate is achieved by incremental increases in stored energy. The simulation tracks the grain size, special boundary fraction, and recrystallization fraction. Recrystallization rates vary with initial special boundary fraction and are compared to kinetic models. Similar to experimental results, a high percentage of grains that nucleate early in the simulation have special-boundary relationships with surrounding ...


Comparison Of Microstructural Evolution Of Nickel During Conventional And Spark Plasma Sintering, Matthew Luke, Darryl Butt, Megan Frary 2010 Boise State University

Comparison Of Microstructural Evolution Of Nickel During Conventional And Spark Plasma Sintering, Matthew Luke, Darryl Butt, Megan Frary

Megan Frary

Spark plasma sintering (SPS) is a rapid powder consolidation technique that uses pulsed electric current to directly heat the powder. A comparison was made between the microstructural evolution of pure polycrystalline nickel powder processed by conventional (press and sinter) and SPS routes. The sintering temperature, dwell time, applied pressure and ramp rate were varied to affect the densification and microstructural evolution of the powders. Characterization of grain size, morphology, grain boundary character, and crystallographic texture was performed on SPS and traditionally-processed specimens using electron backscatter diffraction. The microstructure of SPS nickel was observed to vary between one that resembles a ...


Improving Ozone Modeling In Complex Terrain At A Fine Grid Resolution: Part I – Examination Of Analysis Nudging And All Pbl Schemes Associated With Lsms In Meteorological Model, Yunhee Kim, Joshua Fu, Terry Miller 2010 University of Tennessee, Knoxville

Improving Ozone Modeling In Complex Terrain At A Fine Grid Resolution: Part I – Examination Of Analysis Nudging And All Pbl Schemes Associated With Lsms In Meteorological Model, Yunhee Kim, Joshua Fu, Terry Miller

Joshua Fu

Meteorological variables such as temperature, wind speed, wind directions, and Planetary Boundary Layer (PBL) heights have critical implications for air quality simulations. Sensitivity simulations with five different PBL schemes associated with three different Land Surface Models (LSMs) were conducted to examine the impact of meteorological variables on the predicted ozone concentrations using the Community Multiscale Air Quality (CMAQ) version 4.5 with local perspective. Additionally, the nudging analysis for winds was adopted with three different coefficients to improve the wind fields in the complex terrain at 4-km grid resolution. The simulations focus on complex terrain having valley and mountain areas ...


Three-Dimensional Grain Boundary Networks: Modeling And Connections To Experimental Data, Megan Frary 2010 Boise State University

Three-Dimensional Grain Boundary Networks: Modeling And Connections To Experimental Data, Megan Frary

Megan Frary

The grain boundary network that makes up a microstructure plays an important role in determining the properties of the material. These networks are well-studied in two dimensional systems; however, most microstructures are inherently three dimensional, so an understanding of the role microstructure plays in determining properties must account for the full 3D microstructure. Here, percolation-based models are applied to 3D grain boundary networks with both regular and irregular grain shapes. The microstructures are characterized in terms of the cluster size distribution, mean cluster size, and radius of gyration; grain boundary area must be accounted for when calculating these properties in ...


Weldability Characteristics Of Oxide Dispersion Strengthened Alloys: An Overview, Kalyan Chitrada, Ramprashad Prabhakaran, Jiye Wang, Larry Zirker, Mitchell Meyer, James Cole, Korukonda Murty, Rajiv Mishra, Darryl Butt, Megan Frary, Indrajit Charit 2010 University of Idaho

Weldability Characteristics Of Oxide Dispersion Strengthened Alloys: An Overview, Kalyan Chitrada, Ramprashad Prabhakaran, Jiye Wang, Larry Zirker, Mitchell Meyer, James Cole, Korukonda Murty, Rajiv Mishra, Darryl Butt, Megan Frary, Indrajit Charit

Megan Frary

Oxide dispersion strengthened (ODS) alloys are considered an important class of structural materials for various high temperature applications including advanced nuclear reactors. Conventional fusion welding methods lead to high porosity and agglomerated oxide particles in these alloys deteriorating critical properties of the joint. That is why solid state joining techniques are touted as the potential remedy for the welding issues encountered in these alloys. Research activities in an ongoing research program supported by the DOE (grant # DEFG07-08ID14925) are highlighted. In this program, friction stir welding and pressure resistance welding have been used to successfully weld various ODS alloys, such as ...


Optimal Heating And Energy Management For Slabs In A Reheating Furnace, Wei-Hsin Chen 2010 National Cheng Kung University

Optimal Heating And Energy Management For Slabs In A Reheating Furnace, Wei-Hsin Chen

Wei-Hsin Chen

No abstract provided.


Pulverized Coal Burnout In Blast Furnace Simulated By A Drop Tube Furnace, Wei-Hsin Chen 2010 National Cheng Kung University

Pulverized Coal Burnout In Blast Furnace Simulated By A Drop Tube Furnace, Wei-Hsin Chen

Wei-Hsin Chen

No abstract provided.


Making Sense Of Software Development And Personality Types, Luiz Fernando Capretz, Faheem Ahmed Dr. 2010 University of Western Ontario

Making Sense Of Software Development And Personality Types, Luiz Fernando Capretz, Faheem Ahmed Dr.

Electrical and Computer Engineering Publications

No abstract provided.


Single Cell Manipulation Using Ferromagnetic Composite Microtransporters, Mahmut Selman Sakar, Edward B. Steager, Dal Hyung Kim, Min Jun Kim, George J. Pappas, Vijay Kumar 2010 University of Pennsylvania

Single Cell Manipulation Using Ferromagnetic Composite Microtransporters, Mahmut Selman Sakar, Edward B. Steager, Dal Hyung Kim, Min Jun Kim, George J. Pappas, Vijay Kumar

Lab Papers (GRASP)

For biomedical applications, such as single cell manipulation, it is important to fabricate microstructures that can be powered and controlled wirelessly in fluidic environments. In this letter, we describe the construction and operation of truly micron-sized, biocompatible ferromagnetic microtransporters driven by external magnetic fields. Microtransporters were fabricated using a simple, single step fabrication method and can be produced in large numbers. We demonstrate that they can be navigated to manipulate single cells with micron-size precision without disturbing the local environment.


Modeling Of Commercial Ethylene Oxide Reactor: A Hybrid Approach By Artificial Neural Network & Differential Evolution, Nadeem Muhammed Khalfe 2010 TASNEE

Modeling Of Commercial Ethylene Oxide Reactor: A Hybrid Approach By Artificial Neural Network & Differential Evolution, Nadeem Muhammed Khalfe

Nadeem Khalfe

This study is motivated by a growing popularity of artificial neural network for process modeling and regression problems. However, many ANN regression application studies are performed by ‘expert’ users who have a good understanding of ANN methodology. Since the quality of ANN models depends on a proper setting of ANN architecture and ANN meta-parameters, the main issue for practitioners trying to apply ANN regression is how to set these parameter values (to ensure good generalization performance) for a given data set. Non-expert users face a difficulty in finding an optimum ANN architecture and are often confused about how to choose ...


Inverse Scattering And Acousto-Optic Imaging, Giullaume Bal, John C. Schotland 2010 Columbia University

Inverse Scattering And Acousto-Optic Imaging, Giullaume Bal, John C. Schotland

Departmental Papers (BE)

We propose a tomographic method to reconstruct the optical properties of a highly scattering medium from incoherent acousto-optic measurements. The method is based on the solution to an inverse problem for the diffusion equation and makes use of the principle of interior control of boundary measurements by an external wave field.


Life Cycle Greenhouse Gas Emissions From Biofuels: Variability, Uncertainty, And Steps Toward Accurate Regulation, Adam J. Liska, Bruce E. Dale 2010 University of Nebraska-Lincoln,

Life Cycle Greenhouse Gas Emissions From Biofuels: Variability, Uncertainty, And Steps Toward Accurate Regulation, Adam J. Liska, Bruce E. Dale

Adam Liska Papers

a)Variability in life cycle greenhouse gas (GHG) emissions from corn-ethanol:
biorefineries
cropping systems
co-product feeding to livestock


b) EPA regulation of life cycle GHG emissions from biofuels & use of life cycle analysis (LCA):
uncertainties & inaccuracies
indirect effects


c) Building accurate knowledge infrastructure, theory, and research teams for accurate LCA methods for biofuels


Work In Progress - Attaining And Measuring Global Competency For Engineering Graduates, James Widmann, Linda Vanasupa 2010 California Polytechnic State University - San Luis Obispo

Work In Progress - Attaining And Measuring Global Competency For Engineering Graduates, James Widmann, Linda Vanasupa

Linda Vanasupa

Downey et al. laid out a clear path of learning criteria and outcomes for global competence in their 2006 Journal of Engineering Education publication. We build on their work by integrating other disciplinary perspectives to expand upon the questions: "How can global competency be learned?", and "How can we assess it?" In this work-in-progress paper, we propose an expanded framework for global competence and identify the use of Fink's taxonomy of significant learning as a tool to consider how it can be achieved through careful design of classroom learning experiences. Drawing heavily from other models, our framework attempts to ...


Cuda Implementation Of A Navier-Stokes Solver On Multi-Gpu Desktop Platforms For Incompressible Flows, Julien C. Thibault, Inanc Senocak 2010 Boise State University

Cuda Implementation Of A Navier-Stokes Solver On Multi-Gpu Desktop Platforms For Incompressible Flows, Julien C. Thibault, Inanc Senocak

Inanc Senocak

Graphics processor units (GPU) that are traditionally designed for graphics rendering have emerged as massively-parallel "co-processors" to the central processing unit (CPU). Small-footprint desktop supercomputers with hundreds of cores that can deliver teraflops peak performance at the price of conventional workstations have been realized. A computational fluid dynamics (CFD) simulation capability with rapid computational turnaround time has the potential to transform engineering analysis and design optimization procedures. We describe the implementation of a Navier-Stokes solver for incompressible fluid flow using desktop platforms equipped with multi-GPUs. Specifically, NVIDIA’s Compute Unified Device Architecture (CUDA) programming model is used to implement the ...


An Mpi-Cuda Implementation For Massively Parallel Incompressible Flow Computations On Multi-Gpu Clusters, Dana A. Jacobsen, Julien C. Thibault, Inanc Senocak 2010 Boise State University

An Mpi-Cuda Implementation For Massively Parallel Incompressible Flow Computations On Multi-Gpu Clusters, Dana A. Jacobsen, Julien C. Thibault, Inanc Senocak

Inanc Senocak

Modern graphics processing units (GPUs) with many-core architectures have emerged as general-purpose parallel computing platforms that can accelerate simulation science applications tremendously. While multi-GPU workstations with several TeraFLOPS of peak computing power are available to accelerate computational problems, larger problems require even more resources. Conventional clusters of central processing units (CPU) are now being augmented with multiple GPUs in each compute-node to tackle large problems. The heterogeneous architecture of a multi-GPU cluster with a deep memory hierarchy creates unique challenges in developing scalable and efficient simulation codes. In this study, we pursue mixed MPI-CUDA implementations and investigate three strategies to ...


Stochastic Event Reconstruction Of Atmospheric Contaminant Dispersion Using Bayesian Inference, Inanc Senocak, Nicolas W. Hengartner, Margaret B. Short, W. Brent Daniel 2010 Boise State University

Stochastic Event Reconstruction Of Atmospheric Contaminant Dispersion Using Bayesian Inference, Inanc Senocak, Nicolas W. Hengartner, Margaret B. Short, W. Brent Daniel

Inanc Senocak

Environmental sensors have been deployed in various cities for early detection of contaminant releases into the atmosphere. Event reconstruction and improved dispersion modeling capabilities are needed to estimate the extent of contamination, which is required to implement effective strategies in emergency management. To this end, a stochastic event reconstruction capability that can process information from an environmental sensor network is developed. A probability model is proposed to take into account both zero and non-zero concentration measurements that can be available from a sensor network because of a sensor’s specified limit of detection. The inference is based on the Bayesian ...


Miniature Ceramic Pifa For Uwb Band Group 3 And 6, David Kearney, Matthias John, Max Ammann 2010 Dublin Institute of Technology

Miniature Ceramic Pifa For Uwb Band Group 3 And 6, David Kearney, Matthias John, Max Ammann

Articles

A ceramic chip planar inverted-F antenna (PIFA) is proposed for integration into a mobile handset providing UWB functionality across band groups 3 and 6. The antenna design exhibits a total efficiency of greater than 50% across the entire 6.39 GHz bandwidth while maintaining a very small volume of 57.6 mm^3 . The antenna uses a combination of the normal PIFA resonance and a second resonance due to the ceramic block to achieve a broad ultrawideband (UWB) bandwidth.


Discussion Of “Analyzing Liquefaction-Induced Lateral Spreads Using Strength Ratios" By S.M. Olson And C.I. Johnson, Robb E.S. Moss, Justin Chow Hollenback 2010 California Polytechnic State University - San Luis Obispo

Discussion Of “Analyzing Liquefaction-Induced Lateral Spreads Using Strength Ratios" By S.M. Olson And C.I. Johnson, Robb E.S. Moss, Justin Chow Hollenback

Robb E. S. Moss, Ph.D. P.E. F.ASCE

No abstract provided.


High-Speed Concatenation Of Frequency Ramps Using Sampled Grating Distributed Bragg Reflector Laser Diode Sources For Oct Resolution Enhancement, Brandon George, Dennis J. Derickson 2010 California Polytechnic State University - San Luis Obispo

High-Speed Concatenation Of Frequency Ramps Using Sampled Grating Distributed Bragg Reflector Laser Diode Sources For Oct Resolution Enhancement, Brandon George, Dennis J. Derickson

Electrical Engineering

Brandon George and Dennis Derickson California Polytechnic State Univ. (USA) Wavelength tunable sampled grating distributed Bragg reflector (SG-DBR) lasers used for telecommunications applications have previously demonstrated the ability for linear frequency ramps covering the entire tuning range of the laser at 100 kHz repetition rates1. An individual SG-DBR laser has a typical tuning range of 50 nm. The InGaAs/InP material system often used with SG-DBR lasers allows for design variations that cover the 1250 to 1650 nm wavelength range. This paper addresses the possibility of concatenating the outputs of tunable SGDBR lasers covering adjacent wavelength ranges for enhancing the ...


Systems Social Seience: A Design Inquiry Approach For Stabilization And Reconstruction Of Social Systems, Barry G. Silverman 2010 University of Pennsylvania

Systems Social Seience: A Design Inquiry Approach For Stabilization And Reconstruction Of Social Systems, Barry G. Silverman

Departmental Papers (ESE)

This paper explores novel approaches under the design inquiry paradigm that promise to help organizations better understand and solve socio-technical dilemmas. Design inquiry is contrasted with scientific inquiry (Section 1). Section 2 presents a meso-scale model of models methodology for design inquiry that synthesizes systems science, agent modeling and simulation, knowledge management architectures, and domain theories and knowledge. The goal is to focus computational science on exploring underlying mechanisms (white box modeling) and to support reflective theorizing and discourse to explain social dilemmas and potential resolutions. Section 3 then describes an evolving agent modeling and simulation testbed while Section 4 ...


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