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Accelerating Battery Design Using Computer-Aided Engineering Tools: Preprint (open access)

Accelerating Battery Design Using Computer-Aided Engineering Tools: Preprint

Computer-aided engineering (CAE) is a proven pathway, especially in the automotive industry, to improve performance by resolving the relevant physics in complex systems, shortening the product development design cycle, thus reducing cost, and providing an efficient way to evaluate parameters for robust designs. Academic models include the relevant physics details, but neglect engineering complexities. Industry models include the relevant macroscopic geometry and system conditions, but simplify the fundamental physics too much. Most of the CAE battery tools for in-house use are custom model codes and require expert users. There is a need to make these battery modeling and design tools more accessible to end users such as battery developers, pack integrators, and vehicle makers. Developing integrated and physics-based CAE battery tools can reduce the design, build, test, break, re-design, re-build, and re-test cycle and help lower costs. NREL has been involved in developing various models to predict the thermal and electrochemical performance of large-format cells and has used in commercial three-dimensional finite-element analysis and computational fluid dynamics to study battery pack thermal issues. These NREL cell and pack design tools can be integrated to help support the automotive industry and to accelerate battery design.
Date: January 1, 2011
Creator: Pesaran, A.; Heon, G. H. & Smith, K.
System: The UNT Digital Library
Accurate simulation of the electron cloud in the Fermilab Main Injector with VORPAL (open access)

Accurate simulation of the electron cloud in the Fermilab Main Injector with VORPAL

We present results from a precision simulation of the electron cloud (EC) in the Fermilab Main Injector using the code VORPAL. This is a fully 3d and self consistent treatment of the EC. Both distributions of electrons in 6D phase-space and E.M. field maps have been generated. This has been done for various configurations of the magnetic fields found around the machine have been studied. Plasma waves associated to the fluctuation density of the cloud have been analyzed. Our results are compared with those obtained with the POSINST code. The response of a Retarding Field Analyzer (RFA) to the EC has been simulated, as well as the more challenging microwave absorption experiment. Definite predictions of their exact response are difficult to obtain,mostly because of the uncertainties in the secondary emission yield and, in the case of the RFA, because of the sensitivity of the electron collection efficiency to unknown stray magnetic fields. Nonetheless, our simulations do provide guidance to the experimental program.
Date: January 1, 2011
Creator: Lebrun, Paul L. G.; Spentzouris, Panagiotis; Cary, John R.; Stoltz, Peter & Veitzer, Seth A.
System: The UNT Digital Library
Achievements and Lessons from Tevatron (open access)

Achievements and Lessons from Tevatron

For almost a quarter of a century, the Tevatron proton-antiproton collider was the centerpiece of the world's high energy physics program - beginning operation in December of 1985 until it was overtaken by LHC in 2011. The aim of the this unique scientific instrument was to explore the elementary particle physics reactions with center of mass collision energies of up to 1.96 TeV. The initial design luminosity of the Tevatron was 10{sup 30} cm{sup -2}s{sup -1}, however as a result of two decades of upgrades, the accelerator has been able to deliver 430 times higher luminosities to each of two high luminosity experiments, CDF and D0. Tevatron will be shut off September 30, 2011. The collider was arguably one of the most complex research instruments ever to reach the operation stage and is widely recognized for many technological breakthroughs and numerous physics discoveries. Below we briefly present the history of the Tevatron, major advances in accelerator physics, and technology implemented during the long quest for better and better performance. We also discuss some lessons learned from our experience.
Date: January 1, 2011
Creator: Shiltsev, V.
System: The UNT Digital Library
Application of Distribution Transformer Thermal Life Models to Electrified Vehicle Charging Loads Using Monte-Carlo Method: Preprint (open access)

Application of Distribution Transformer Thermal Life Models to Electrified Vehicle Charging Loads Using Monte-Carlo Method: Preprint

Concentrated purchasing patterns of plug-in vehicles may result in localized distribution transformer overload scenarios. Prolonged periods of transformer overloading causes service life decrements, and in worst-case scenarios, results in tripped thermal relays and residential service outages. This analysis will review distribution transformer load models developed in the IEC 60076 standard, and apply the model to a neighborhood with plug-in hybrids. Residential distribution transformers are sized such that night-time cooling provides thermal recovery from heavy load conditions during the daytime utility peak. It is expected that PHEVs will primarily be charged at night in a residential setting. If not managed properly, some distribution transformers could become overloaded, leading to a reduction in transformer life expectancy, thus increasing costs to utilities and consumers. A Monte-Carlo scheme simulated each day of the year, evaluating 100 load scenarios as it swept through the following variables: number of vehicle per transformer, transformer size, and charging rate. A general method for determining expected transformer aging rate will be developed, based on the energy needs of plug-in vehicles loading a residential transformer.
Date: January 1, 2011
Creator: Kuss, M.; Markel, T. & Kramer, W.
System: The UNT Digital Library
Application of the Theory of Interacting Continua to Blood Flow (open access)

Application of the Theory of Interacting Continua to Blood Flow

Micro-scale investigations of the flow and deformation of blood and its formed elements have been studied for many years. Early in vitro investigations in the rotational viscometers or small glass tubes revealed important rheological properties such as the reduced blood apparent viscosity, Fahraeus effect and Fahraeus-Lindqvist effect [1], exhibiting the nonhomogeneous property of blood in microcirculation. We have applied Mixture Theory, also known as Theory of Interacting Continua, to study and model this property of blood [2, 3]. This approach holds great promise for predicting the trafficking of RBCs in micro-scale flows (such as the depletion layer near the wall), and other unique hemorheological phenomena relevant to blood trauma. The blood is assumed to be composed of an RBC component modeled as a nonlinear fluid, suspended in plasma, modeled as a linearly viscous fluid.
Date: January 1, 2011
Creator: Massoudi, Mehrdad; Kim, Jeongho; Hund, Samuel J. & Antaki, James F.
System: The UNT Digital Library
Assessment of Styrene Oxide Neurotoxicity Using In Vitro Auditory Cortex Networks (open access)

Assessment of Styrene Oxide Neurotoxicity Using In Vitro Auditory Cortex Networks

Article discussing an assessment of styrene oxide neurotoxicity using in vitro auditory cortex networks.
Date: 2011
Creator: Gopal, Kamakshi V.; Wu, Calvin; Moore, Ernest J. & Gross, Guenter W.
System: The UNT Digital Library
Azimuthal decorrelations and multiple parton interactions in photon+2 jet and photon+3 jet events in ppbar collisions at sqrt{s}=1.96 TeV (open access)

Azimuthal decorrelations and multiple parton interactions in photon+2 jet and photon+3 jet events in ppbar collisions at sqrt{s}=1.96 TeV

Samples of inclusive {gamma} + 2 jet and {gamma} + 3 jet events collected by the D0 experiment with an integrated luminosity of about 1 fb{sup -1} in p{bar p} collisions at {radical}s = 1.96 TeV are used to measure cross sections as a function of the angle in the plane transverse to the beam direction between the transverse momentum (p{sub T}) of the {gamma} + leading jet system (jets are ordered in p{sub T}) and p{sub T} of the other jet for {gamma} + 2 jet, or p{sub T} sum of the two other jets for {gamma} + 3 jet events. The results are compared to different models of multiple parton interactions (MPI) in the pythia and sherpa Monte Carlo (MC) generators. The data indicate a contribution from events with double parton (DP) interactions and are well described by predictions provided by the pythia MPI models with p{sub T}-ordered showers and by sherpa with the default MPI model. The {gamma} + 2 jet data are also used to determine the fraction of events with DP interactions as a function of the azimuthal angle and as a function of the second jet p{sub T}.
Date: January 1, 2011
Creator: Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; U., /Oklahoma; Acharya, Bannanje Sripath; Inst., /Tata et al.
System: The UNT Digital Library
Battery Ownership Model: A Tool for Evaluating the Economics of Electrified Vehicles and Related Infrastructure; Preprint (open access)

Battery Ownership Model: A Tool for Evaluating the Economics of Electrified Vehicles and Related Infrastructure; Preprint

Electric vehicles could significantly reduce greenhouse gas (GHG) emissions and dependence on imported petroleum. However, for mass adoption, EV costs have historically been too high to be competitive with conventional vehicle options due to the high price of batteries, long refuel time, and a lack of charging infrastructure. A number of different technologies and business strategies have been proposed to address some of these cost and utility issues: battery leasing, battery fast-charging stations, battery swap stations, deployment of charge points for opportunity charging, etc. In order to investigate these approaches and compare their merits on a consistent basis, the National Renewable Energy Laboratory (NREL) has developed a new techno-economic model. The model includes nine modules to examine the levelized cost per mile for various types of powertrain and business strategies. The various input parameters such as vehicle type, battery, gasoline, and electricity prices; battery cycle life; driving profile; and infrastructure costs can be varied. In this paper, we discuss the capabilities of the model; describe key modules; give examples of how various assumptions, powertrain configurations, and business strategies impact the cost to the end user; and show the vehicle's levelized cost per mile sensitivity to seven major operational parameters.
Date: January 1, 2011
Creator: O'Keefe, M.; Brooker, A.; Johnson, C.; Mendelsohn, M.; Neubauer, J. & Pesaran, A.
System: The UNT Digital Library
Beam-beam simulation code BBSIM for particle accelerators (open access)

Beam-beam simulation code BBSIM for particle accelerators

A highly efficient, fully parallelized, six-dimensional tracking model for simulating interactions of colliding hadron beams in high energy ring colliders and simulating schemes for mitigating their effects is described. The model uses the weak-strong approximation for calculating the head-on interactions when the test beam has lower intensity than the other beam, a look-up table for the efficient calculation of long-range beam-beam forces, and a self-consistent Poisson solver when both beams have comparable intensities. A performance test of the model in a parallel environment is presented. The code is used to calculate beam emittance and beam loss in the Tevatron at Fermilab and compared with measurements. They also present results from the studies of stwo schemes proposed to compensate the beam-beam interactions: (a) the compensation of long-range interactions in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven and the Large Hadron Collider (LHC) at CERN with a current carrying wire, (b) the use of a low energy electron beam to compensate the head-on interactions in RHIC.
Date: January 1, 2011
Creator: Kim, Hyung J. & Sen, Tanaji
System: The UNT Digital Library
Bhopal Chemical Disaster (open access)

Bhopal Chemical Disaster

Encyclopedia article describing the devastating effects of a chemical disaster that took place in Bhopal, India in 1984. The author describes the effects of the chemical disaster and the events that followed.
Date: 2011
Creator: Gupta, Kailash
System: The UNT Digital Library
Breast Cancer in Texas Counties 1980-1998 (open access)

Breast Cancer in Texas Counties 1980-1998

Paper examines effects of race/ethnicity, socioeconomic status, genes and environment on breast cancer morbidity in Texas counties from 1980-1998.
Date: 2011
Creator: Barry, Djenabou
System: The UNT Digital Library
The CDMS II data acquisition system (open access)

The CDMS II data acquisition system

The Data Acquisition System for the CDMS II dark matter experiment was designed and built when the experiment moved to its new underground installation at the Soudan Lab. The combination of remote operation and increased data load necessitated a completely new design. Elements of the original LabView system remained as stand-alone diagnostic programs, but the main data processing moved to a VME-based system with custom electronics for signal conditioning, trigger formation and buffering. The data rate was increased 100-fold and the automated cryogenic system was linked to the data acquisition. A modular server framework with associated user interfaces was implemented in Java to allow control and monitoring of the entire experiment remotely.
Date: January 1, 2011
Creator: Bauer, D. A.; /Fermilab; Burke, S.; /UC, Santa Barbara; Cooley, J.; U., /Southern Methodist et al.
System: The UNT Digital Library
Contrasting Perceptions of STEM Content and Careers (open access)

Contrasting Perceptions of STEM Content and Careers

This article presents a second year analysis of baseline attitudinal data gathered from a National Science Foundation Innovative Technology Experiences for Students and Teachers project concerning contrasts between the perceptions of practicing professionals and students toward science, technology, engineering, and mathematics (STEM) disciplines and careers.
Date: January 2011
Creator: Knezek, Gerald; Christensen, Rhonda & Tyler-Wood, Tandra L.
System: The UNT Digital Library
Correlation of Solute Transfer Into Toluene and Ethylbenzene from Water and from the Gas Phase Based on the Abraham Model (open access)

Correlation of Solute Transfer Into Toluene and Ethylbenzene from Water and from the Gas Phase Based on the Abraham Model

This article discusses correlation of solute transfer into toluene and ethylbenzene from water and from the gas phase based on the Abraham model.
Date: 2011
Creator: Stephens, Timothy W.; Loera, Matthew; Quay, Amanda N.; Chou, Vicky; Shen, Connie; Wilson, Anastasia et al.
System: The UNT Digital Library
Coupled models and parallel simulations for three-dimensional full-Stokes ice sheet modeling (open access)

Coupled models and parallel simulations for three-dimensional full-Stokes ice sheet modeling

A three-dimensional full-Stokes computational model is considered for determining the dynamics, temperature, and thickness of ice sheets. The governing thermomechanical equations consist of the three-dimensional full-Stokes system with nonlinear rheology for the momentum, an advective-diffusion energy equation for temperature evolution, and a mass conservation equation for icethickness changes. Here, we discuss the variable resolution meshes, the finite element discretizations, and the parallel algorithms employed by the model components. The solvers are integrated through a well-designed coupler for the exchange of parametric data between components. The discretization utilizes high-quality, variable-resolution centroidal Voronoi Delaunay triangulation meshing and existing parallel solvers. We demonstrate the gridding technology, discretization schemes, and the efficiency and scalability of the parallel solvers through computational experiments using both simplified geometries arising from benchmark test problems and a realistic Greenland ice sheet geometry.
Date: January 1, 2011
Creator: Zhang, Huai; Ju, Lili; Gunzburger, Max; Ringler, Todd & Price, Stephen
System: The UNT Digital Library

Cracking the Code: Using Tonal Theory to Solve the Puzzle Between the Notes

Access: Use of this item is restricted to the UNT Community
This article discusses strategies for harpists to use music theory for learning and memorizing music.
Date: 2011
Creator: Haefner, Jaymee
System: The UNT Digital Library
Democratization in the Middle East and North Africa: Challenges, Explanations and Suggestions for the Future (open access)

Democratization in the Middle East and North Africa: Challenges, Explanations and Suggestions for the Future

Paper explores why democratization has been unsuccessful in the Middle East and North Africa, and the impact of the U.S. and global policy on this failure.
Date: 2011
Creator: Young, Krysten
System: The UNT Digital Library
Demonstrating the Uses of the Novel Gravitational Force Spectrometer to Stretch and Measure Fibrous Proteins (open access)

Demonstrating the Uses of the Novel Gravitational Force Spectrometer to Stretch and Measure Fibrous Proteins

Article on demonstrating the uses of the novel gravitational force spectrometer to stretch and measure fibrous proteins.
Date: 2011
Creator: Dunn, James W. & Root, Douglas D.
System: The UNT Digital Library
Demonstrating the Uses of the Novel Gravitational Force Spectrometer to Stretch and Measure Fibrous Proteins (open access)

Demonstrating the Uses of the Novel Gravitational Force Spectrometer to Stretch and Measure Fibrous Proteins

Article on demonstrating the uses of the novel gravitational force spectrometer to stretch and measure fibrous proteins.
Date: 2011
Creator: Dunn, James W. & Root, Douglas D.
System: The UNT Digital Library
Density functional theory study of the structural, electronic, lattice dynamical, and thermodynamic properties of Li4SiO4 and its capability for CO2 capture (open access)

Density functional theory study of the structural, electronic, lattice dynamical, and thermodynamic properties of Li4SiO4 and its capability for CO2 capture

The structural, electronic, lattice dynamical, optical, thermodynamic, and CO{sub 2} capture properties of monoclinic and triclinic phases of Li{sub 4}SiO{sub 4} are investigated by combining density functional theory with phonon lattice dynamics calculations. We found that these two phases have some similarities in their bulk and thermodynamic properties. The calculated bulk modulus and the cohesive energies of these two phases are close to each other. Although both of them are insulators, the monoclinic phase of Li{sub 4}SiO{sub 4} has a direct band gap of 5.24 eV while the triclinic Li{sub 4}SiO{sub 4} phase has an indirect band gap of 4.98 eV. In both phases of Li{sub 4}SiO{sub 4}, the s orbital of O mainly contributes to the lower-energy second valence band (VB{sub 2}) and the p orbitals contribute to the fist valence band (VB{sub 1}) and the conduction bands (CBs). The s orbital of Si mainly contributes to the lower portions of the VB1 and VB{sub 2}, and Si p orbitals mainly contribute to the higher portions of the VB{sub 1} and VB{sub 2}. The s and p orbitals of Li contribute to both VBs and to CBs, and Li p orbitals have a higher contribution than the Li s …
Date: January 1, 2011
Creator: Duan, Yuhua & Parlinski, K.
System: The UNT Digital Library
Development of Direct-Use Projects: Preprint (open access)

Development of Direct-Use Projects: Preprint

A geothermal direct-use project utilizes a natural resource, a flow of geothermal fluid at elevated temperatures, which is capable of providing heat and/or cooling to buildings, greenhouses, aquaculture ponds, and industrial processes. Geothermal utilization requires matching the varied needs of the user and characteristics of the resource in order to development a successful project. Each application is unique; guidelines are provided for the logical steps required to implement a project. Recommended temperature and flows are suggested for spas and pools, space and district heating, greenhouse and aquaculture pond heating, and industrial applications. Guidelines are provided for selecting the necessary equipment for successfully implementing a direct-use project, including downhole pumps, piping, heat exchangers, and heat convectors. Additionally, the relationship between temperature, flow rate, and the use of heat exchangers to provide heat to a space with hot water or hot air is provided for a number of applications, with suggested 'rules of thumb'.
Date: January 1, 2011
Creator: Lund, J.
System: The UNT Digital Library
Documenting Captured Records From Terrorist Organizations (open access)

Documenting Captured Records From Terrorist Organizations

Article discussing documenting captured records from terrorist organizations. This article discusses documenting captured records from terrorist organizations. During the 2003 invasion of Iraq, American forces captured 43,000 boxes of government documents and thousands of hours of previously unknown audio recordings. This article traces the release of these records, archival considerations, political initiatives, effect of these records on protecting the public, and future developments.
Date: 2011
Creator: Gieringer, Morgan Davis
System: The UNT Digital Library
Drugs and Peace Duration (open access)

Drugs and Peace Duration

Paper explores the impact that the production and/or transit of drugs have on the durability of peace following civil war.
Date: 2011
Creator: Adams, Mark
System: The UNT Digital Library
Education and Civil Unrest (open access)

Education and Civil Unrest

Paper explores the relationship between education and civil unrest, specifically in Sub-Saharan Africa.
Date: 2011
Creator: Smith, Amber
System: The UNT Digital Library