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Protein Sequence Classification Using Feature Hashing (open access)

Protein Sequence Classification Using Feature Hashing

Article on protein sequence classification using feature hashing.
Date: June 21, 2012
Creator: Caragea, Cornelia; Silvescu, Adrian & Mitra, Prasenjit
System: The UNT Digital Library
Reconfigurable Surface Plasmon Polariton Wave Adapter Designed by Transformation Optics (open access)

Reconfigurable Surface Plasmon Polariton Wave Adapter Designed by Transformation Optics

This article proposes a reconfigurable surface plasmon polariton (SPP) wave adapter designed by transformation optics, which can control the propagation of SPP waves on un-even surfaces.
Date: June 18, 2012
Creator: Arigong, Bayaner; Shao, Jin; Ren, Han; Zheng, Geng; Lutkenhaus, Jeffrey; Kim, HyoungSoo et al.
System: The UNT Digital Library
High-Penetration PV Deployment in the Arizona Public Service System, Phase 1 Update: Preprint (open access)

High-Penetration PV Deployment in the Arizona Public Service System, Phase 1 Update: Preprint

In an effort to better understand the impacts of high penetrations of photovoltaic generators on distribution systems, Arizona Public Service and its partners have begun work on a multi-year project to develop the tools and knowledge base needed to safely and reliably integrate high penetrations of utility- and residential-scale photovoltaics (PV). Building upon the APS Community Power Project -- Flagstaff Pilot, this project will analyze the impact of PV on a representative feeder in northeast Flagstaff. To quantify and catalog the effects of the estimated 1.3 MW of PV that will be installed on the feeder (both smaller units at homes as well as large, centrally located systems), high-speed weather and electrical data acquisition systems and digital 'smart' meters are being designed and installed to facilitate monitoring and to build and validate comprehensive, high-resolution models of the distribution system. These models will be used to analyze the impacts of the PV on distribution circuit protection systems (including anti-islanding), predict voltage regulation and phase balance issues, and develop volt/var control schemes. This paper continues from a paper presented at the 2011 IEEE PVSC conference that introduces the project and describes some of the preliminary consideration, as well as project plans and …
Date: June 1, 2012
Creator: Hambrick, J. & Narang, D.
System: The UNT Digital Library
4 kW Test of Solid Oxide Electrolysis Stacks with Advanced Electrode-Supported Cells (open access)

4 kW Test of Solid Oxide Electrolysis Stacks with Advanced Electrode-Supported Cells

A new test stand has been developed at the Idaho National Laboratory for multi-kW testing of solid oxide electrolysis stacks. This test stand will initially be operated at the 4 KW scale. The 4 kW tests will include two 60-cell stacks operating in parallel in a single hot zone. The stacks are internally manifolded with an inverted-U flow pattern and an active area of 100 cm2 per cell. Process gases to and from the two stacks are distributed from common inlet/outlet tubing using a custom base manifold unit that also serves as the bottom current collector plate. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. Treated metallic interconnects with integral flow channels separate the cells and electrode gases. Sealing is accomplished with compliant mica-glass seals. A spring-loaded test fixture is used for mechanical stack compression. Due to the power level and the large number of cells in the hot zone, process gas flow rates are high and heat recuperation is required to preheat the cold inlet gases upstream of the furnace. Heat recuperation is achieved by means of two inconel tube-in-tube counter-flow heat exchangers. …
Date: June 1, 2012
Creator: O'Brien, J. E.; Zhang, X.; Housley, G. K.; Moore-McAteer, L. & Tao, G.
System: The UNT Digital Library
Microworlds, Simulators, and Simulation: Framework for a Benchmark of Human Reliability Data Sources (open access)

Microworlds, Simulators, and Simulation: Framework for a Benchmark of Human Reliability Data Sources

In this paper, we propose a method to improve the data basis of human reliability analysis (HRA) by extending the data sources used to inform HRA methods. Currently, most HRA methods are based on limited empirical data, and efforts to enhance the empirical basis behind HRA methods have not yet yielded significant new data. Part of the reason behind this shortage of quality data is attributable to the data sources used. Data have been derived from unrelated industries, from infrequent risk-significant events, or from costly control room simulator studies. We propose a benchmark of four data sources: a simplified microworld simulator using unskilled student operators, a full-scope control room simulator using skilled student operators, a full-scope control room simulator using licensed commercial operators, and a human performance modeling and simulation system using virtual operators. The goal of this research is to compare findings across the data sources to determine to what extent data may be used and generalized from cost effective sources.
Date: June 1, 2012
Creator: Boring, Ronald; Kelly, Dana; Smidts, Carol; Mosleh, Ali & Dyre, Brian
System: The UNT Digital Library
A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry (open access)

A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry

We describe the theory and first experimental work on our concept for searching on earth for the presence of dark contents of the vacuum (DCV) using atom interferometry. Specifically, we have in mind any DCV that has not yet been detected on a laboratory scale, but which might manifest itself as dark energy on the cosmological scale. The experimental method uses two atom interferometers to cancel the effect of earth's gravity and diverse noise sources. It depends upon two assumptions: first, that the DCV possesses some space inhomogeneity in density, and second that it exerts a sufficiently strong nongravitational force on matter. The motion of the apparatus through the DCV should then lead to an irregular variation in the detected matter-wave phase shift. We discuss the nature of this signal and note the problem of distinguishing it from instrumental noise. We also discuss the relation of our experiment to what might be learned by studying the noise in gravitational wave detectors such as LIGO. The paper concludes with a projection that a future search of this nature might be carried out using an atom interferometer in an orbiting satellite. The laboratory apparatus is now being constructed.
Date: June 11, 2012
Creator: Adler, Ronald J.; /Stanford U., HEPL /San Francisco State U.; Muller, Holger; /UC, Berkeley; Perl, Martin L. & /KIPAC, Menlo Park /SLAC
System: The UNT Digital Library
The UA9 Experimental Layout (open access)

The UA9 Experimental Layout

None
Date: June 13, 2012
Creator: Scandale, W.; Arduini, G.; Assmann, R.; Bracco, C.; Cerutti, F.; Christiansen, J. et al.
System: The UNT Digital Library
Recent Bottomonium Results from BaBar (open access)

Recent Bottomonium Results from BaBar

Preliminary results from spectroscopic bottomonium studies of the {Upsilon}(2S) and {Upsilon} (3S) datasets collected by BABAR are presented.
Date: June 4, 2012
Creator: Fulsom, B.G.
System: The UNT Digital Library
Comparison of Plug-In Hybrid Electric Vehicle Battery Life Across Geographies and Drive-Cycles (open access)

Comparison of Plug-In Hybrid Electric Vehicle Battery Life Across Geographies and Drive-Cycles

In a laboratory environment, it is cost prohibitive to run automotive battery aging experiments across a wide range of possible ambient environment, drive cycle and charging scenarios. Since worst-case scenarios drive the conservative sizing of electric-drive vehicle batteries, it is useful to understand how and why those scenarios arise and what design or control actions might be taken to mitigate them. In an effort to explore this problem, this paper applies a semi-empirical life model of the graphite/nickel-cobalt-aluminum lithium-ion chemistry to investigate impacts of geographic environments under storage and simplified cycling conditions. The model is then applied to analyze complex cycling conditions, using battery charge/discharge profiles generated from simulations of PHEV10 and PHEV40 vehicles across 782 single-day driving cycles taken from Texas travel survey data.
Date: June 1, 2012
Creator: Smith, K.; Warleywine, M.; Wood, E.; Neubauer, J. & Pesaran, A.
System: The UNT Digital Library
Techniques for correcting velocity and density fluctuations of ion beams (open access)

Techniques for correcting velocity and density fluctuations of ion beams

None
Date: June 19, 2012
Creator: Woo, K. M.; Yu, S. S. & Barnard, J. J.
System: The UNT Digital Library
Event processing track symmary for CHEP 2012 (open access)

Event processing track symmary for CHEP 2012

None
Date: June 1, 2012
Creator: Lyon, Adam L.
System: The UNT Digital Library
3D Equilibrium Effects Due to RMP Application on DIII-D (open access)

3D Equilibrium Effects Due to RMP Application on DIII-D

The mitigation and suppression of edge localized modes (ELMs) through application of resonant magnetic perturbations (RMPs) in Tokamak plasmas is a well documented phenomenon [1]. Vacuum calculations suggest the formation of edge islands and stochastic regions when RMPs are applied to the axisymmetric equilibria. Self-consistent calculations of the plasma equilibrium with the VMEC [2] and SPEC [3] codes have been performed for an up-down symmetric shot (142603) in DIII-D. In these codes, a self-consistent calculation of the plasma response due to the RMP coils is calculated. The VMEC code globally enforces the constraints of ideal MHD; consequently, a continuously nested family of flux surfaces is enforced throughout the plasma domain. This approach necessarily precludes the observation of islands or field-line chaos. The SPEC code relaxes the constraints of ideal MHD locally, and allows for islands and field line chaos at or near the rational surfaces. Equilibria with finite pressure gradients are approximated by a set of discrete "ideal-interfaces" at the most irrational flux surfaces and where the strongest pressure gradients are observed. Both the VMEC and SPEC calculations are initialized from EFIT reconstructions of the plasma that are consistent with the experimental pressure and current profiles. A 3D reconstruction using …
Date: June 20, 2012
Creator: Lazerson, S.; Lazarus, E.; Hudson, S.; Pablant, N. & Gates, D.
System: The UNT Digital Library
PHASE II VAULT TESTING OF THE ARGONNE RFID SYSTEM (open access)

PHASE II VAULT TESTING OF THE ARGONNE RFID SYSTEM

The U.S. Department of Energy (DOE) (Environmental Management [EM], Office of Packaging and Transportation [EM-45]) Packaging and Certification Program (DOE PCP) has developed a Radio Frequency Identification (RFID) tracking and monitoring system, called ARG-US, for the management of nuclear materials packages during transportation and storage. The performance of the ARG-US RFID equipment and system has been fully tested in two demonstration projects in April 2008 and August 2009. With the strong support of DOE-SR and DOE PCP, a field testing program was completed in Savannah River Site's K-Area Material Storage (KAMS) Facility, an active Category I Plutonium Storage Facility, in 2010. As the next step (Phase II) of continued vault testing for the ARG-US system, the Savannah River Site K Area Material Storage facility has placed the ARG-US RFIDs into the 910B storage vault for operational testing. This latest version (Mark III) of the Argonne RFID system now has the capability to measure radiation dose and dose rate. This paper will report field testing progress of the ARG-US RFID equipment in KAMS, the operability and reliability trend results associated with the applications of the system, and discuss the potential benefits in enhancing safety, security and materials accountability. The purpose of …
Date: June 25, 2012
Creator: Willoner, T.; Turlington, R. & Koenig, R.
System: The UNT Digital Library
Gluons and the Quark Sea at High Energies: Distributions, Polarization, Tomography (open access)

Gluons and the Quark Sea at High Energies: Distributions, Polarization, Tomography

This report on the science case for an Electron-Ion Collider (EIC) is the result of a ten-week program at the Institute for Nuclear Theory (INT) in Seattle (from September 13-November 19, 2010), motivated by the need to develop a strong case for the continued study of the QCD description of hadron structure in the coming decades. Hadron structure in the valence quark region will be studied extensively with the Jefferson Lab 12 GeV science program, the subject of an INT program the previous year. The focus of the INT program was on understanding the role of gluons and sea quarks, the important dynamical degrees of freedom describing hadron structure at high energies. Experimentally, the most direct and precise way to access the dynamical structure of hadrons and nuclei at high energies is with a high luminosity lepton probe in collider mode. An EIC with optimized detectors offers enormous potential as the next generation accelerator to address many of the most important, open questions about the fundamental structure of matter. The goal of the INT program, as captured in the writeups in this report, was to articulate these questions and to identify golden experiments that have the greatest potential to provide …
Date: June 7, 2012
Creator: Boer, Daniel; Diehl, Markus; Milner, Richard; Venugopalan, Raju; Vogelsang, Werner; Kaplan, David et al.
System: The UNT Digital Library
Searches for New Physics in Top Events at the Tevatron (open access)

Searches for New Physics in Top Events at the Tevatron

Recent results of searches for new physics in top events at the Tevatron are presented. In case of CDF three searches are discussed using 6 to 8.7 fb{sup -1} of data, with the latter being the final CDF data sample available for this kind of analysis. CDF carried out a search for Top + jet resonance production, dark matter production in association with single top and boosted tops. No signs of new physics are observed and instead upper limits are derived. D0 used 5.3 fb{sup -1} of data and searched for a narrow resonance in t{bar t} production and a time dependent t{bar t} cross section, which would reveal a violation of Lorentz invariance. However, no signs for deviations from standard model are seen and instead upper limits for non-standard model contributions are calculated.
Date: June 1, 2012
Creator: Jung, A.W.
System: The UNT Digital Library
Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon Solar Cells: Preprint (open access)

Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon Solar Cells: Preprint

Post-deposition hydrogenation by remote plasma significantly improves performance of heteroepitaxial silicon solar cells. Heteroepitaxial deposition of thin crystal silicon on sapphire for photovoltaics (PV) is an excellent model system for the study and improvement of deposition on inexpensive Al2O3-coated (100) biaxially-textured metal foils. Without hydrogenation, PV conversion efficiencies are less than 1% on our model system. Performance is limited by carrier recombination at electrically active dislocations that result from lattice mismatch, and other defects. We find that low-temperature hydrogenation at 350 degrees C is more effective than hydrogenation at 610 degrees C. In this work, we use measurements such as spectral quantum efficiency, secondary ion mass spectrometry (SIMS), and vibrational Si-H spectroscopies to understand the effects of hydrogenation on the materials and devices. Quantum efficiency increases most at red and green wavelengths, indicating hydrogenation is affecting the bulk more than the surface of the cells. SIMS shows there are 100X more hydrogen atoms in our cells than dangling bonds along dislocations. Yet, Raman spectroscopy indicates that only low temperature hydrogenation creates Si-H bonds; trapped hydrogen does not stably passivate dangling-bond recombination sites at high temperatures.
Date: June 1, 2012
Creator: Bolen, M. L.; Grover, S.; Teplin, C. W.; Bobela, D.; Branz, H. M. & Stradins, P.
System: The UNT Digital Library
Electron Correlation Effects in Uranium Dioxide from X-ray Emission Spectroscopy (open access)

Electron Correlation Effects in Uranium Dioxide from X-ray Emission Spectroscopy

None
Date: June 11, 2012
Creator: Yu, S W & Tobin, J G
System: The UNT Digital Library
A 4 to 0.1 nm FEL Based on the SLAC Linac (open access)

A 4 to 0.1 nm FEL Based on the SLAC Linac

The author show that using existing electron gun technology and a high energy linac like the one at SLAC, it is possible to build a Free Electron Laser operating around the 4 nm water window. A modest improvement in the gun performance would further allow to extend the FEL to the 0.1 nm region. Such a system would produce radiation with a brightness many order of magnitude above that of any synchrotron radiation source, existing or under construction, with laser power in the multigawatt region and subpicosecond pulse length.
Date: June 5, 2012
Creator: Pellegrini, C.
System: The UNT Digital Library
Effect of Front-Side Silver Metallization on Underlying n+-p Junction in Multicrystalline Silicon Solar Cells: Preprint (open access)

Effect of Front-Side Silver Metallization on Underlying n+-p Junction in Multicrystalline Silicon Solar Cells: Preprint

We report on the effect of front-side Ag metallization on the underlying n+-p junction of multicrystalline Si solar cells. The junction quality beneath the contacts was investigated by characterizing the uniformities of the electrostatic potential and doping concentration across the junction, using scanning Kelvin probe force microscopy and scanning capacitance microscopy. We investigated cells with a commercial Ag paste (DuPont PV159) and fired at furnace setting temperatures of 800 degrees, 840 degrees, and 930 degrees C, which results in actual cell temperatures ~100 degrees C lower than the setting temperature and the three cells being under-, optimal-, and over-fired. We found that the uniformity of the junction beneath the Ag contact was significantly degraded by the over-firing, whereas the junction retained good uniformity with the optimal- and under-fire temperatures. Further, Ag crystallites with widely distributed sizes from <100 nm to several &#956;m were found at the Ag/Si interface of the over-fired cell. Large crystallites were imaged as protrusions into Si deeper than the junction depth. However, the junction was not broken down; instead, it was reformed on the entire front of the crystallite/Si interface. We propose a mechanism of the junction-quality degradation, based on emitter Si melting at the temperature …
Date: June 1, 2012
Creator: Jiang, C. S.; Li, Z. G.; Moutinho, H. R.; Liang, L.; Ionkin, A. & Al-Jassim, M. M.
System: The UNT Digital Library
P50/P90 Analysis for Solar Energy Systems Using the System Advisor Model: Preprint (open access)

P50/P90 Analysis for Solar Energy Systems Using the System Advisor Model: Preprint

To secure competitive financing for a solar energy generation project, the economic risk associated with interannual solar resource variability must be quantified. One way to quantify this risk is to calculate exceedance probabilities representing the amount of energy expected to be produced by a plant. Many years of solar radiation and metereological data are required to determine these values, often called P50 or P90 values for the level of certainty they represent. This paper describes the two methods implemented in the National Renewable Energy Laboratory's System Advisor Model (SAM) to calculate P50 and P90 exceedance probabilities for solar energy projects. The methodology and supporting data sets are applicable to photovoltaic, solar water heating, and concentrating solar power (CSP) systems.
Date: June 1, 2012
Creator: Dobos, A. P.; Gilman, P. & Kasberg, M.
System: The UNT Digital Library
Case Studies Comparing System Advisor Model (SAM) Results to Real Performance Data: Preprint (open access)

Case Studies Comparing System Advisor Model (SAM) Results to Real Performance Data: Preprint

NREL has completed a series of detailed case studies comparing the simulations of the System Advisor Model (SAM) and measured performance data or published performance expectations. These case studies compare PV measured performance data with simulated performance data using appropriate weather data. The measured data sets were primarily taken from NREL onsite PV systems and weather monitoring stations.
Date: June 1, 2012
Creator: Blair, N.; Dobos, A. & Sather, N.
System: The UNT Digital Library
Aerial Measuring System (AMS) Baseline Surveys for Emergency Planning (open access)

Aerial Measuring System (AMS) Baseline Surveys for Emergency Planning

Originally established in the 1960s to support the Nuclear Test Program, the AMS mission is to provide a rapid and comprehensive worldwide aerial measurement, analysis, and interpretation capability in response to a nuclear/radiological emergency. AMS provides a responsive team of individuals whose processes allow for a mission to be conducted and completed with results available within hours. This presentation slide-show reviews some of the history of the AMS, summarizes present capabilities and methods, and addresses the value of the surveys.
Date: June 4, 2012
Creator: Lyons, C
System: The UNT Digital Library
Field Tolerances for the Triplet Quadrupoles of the LHC High Luminosity Lattice (open access)

Field Tolerances for the Triplet Quadrupoles of the LHC High Luminosity Lattice

It has been proposed to implement the so-called Achromatic Telescopic Squeezing (ATS) scheme in the LHC high luminosity (HL) lattice to reduce beta functions at the Interaction Points (IP) up to a factor of 8. As a result, the nominal 4.5 km peak beta functions reached in the Inner Triplets (IT) at collision will be increased by the same factor. This, therefore, justifies the installation of new, larger aperture, superconducting IT quadrupoles. The higher beta functions will enhance the effects of the triplet quadrupole field errors leading to smaller beam dynamic aperture (DA). To maintain the acceptable DA, the effects of the triplet field errors must be re-evaluated, thus specifying new tolerances. Such a study has been performed for the so-called '4444' collision option of the HL-LHC layout version SLHCV3.01, where the IP beta functions are reduced by a factor of 4 in both planes with respect to a pre-squeezed value of 60 cm at two collision points. The dynamic aperture calculations were performed using SixTrack. The impact on the triplet field quality is presented.
Date: June 25, 2012
Creator: Nosochkov, Yuri; Cai, Y.; Jiao, Y.; Wang, M. H.; Fartoukh, S.; Giovannozzi, M. et al.
System: The UNT Digital Library
Robust Optical Richness Estimation with Reduced Scatter (open access)

Robust Optical Richness Estimation with Reduced Scatter

Reducing the scatter between cluster mass and optical richness is a key goal for cluster cosmology from photometric catalogs. We consider various modifications to the red-sequence matched filter richness estimator of Rozo et al. (2009b), and evaluate their impact on the scatter in X-ray luminosity at fixed richness. Most significantly, we find that deeper luminosity cuts can reduce the recovered scatter, finding that {sigma}{sub ln L{sub X}|{lambda}} = 0.63 {+-} 0.02 for clusters with M{sub 500c} {approx}&gt; 1.6 x 10{sup 14} h{sub 70}{sup -1} M{sub {circle_dot}}. The corresponding scatter in mass at fixed richness is {sigma}{sub ln M|{lambda}} {approx} 0.2-0.3 depending on the richness, comparable to that for total X-ray luminosity. We find that including blue galaxies in the richness estimate increases the scatter, as does weighting galaxies by their optical luminosity. We further demonstrate that our richness estimator is very robust. Specifically, the filter employed when estimating richness can be calibrated directly from the data, without requiring a-priori calibrations of the red-sequence. We also demonstrate that the recovered richness is robust to up to 50% uncertainties in the galaxy background, as well as to the choice of photometric filter employed, so long as the filters span the 4000 {angstrom} …
Date: June 7, 2012
Creator: Rykoff, E. S.; Koester, B. P.; Rozo, E.; Annis, J.; Evrard, A. E.; Hansen, S. M. et al.
System: The UNT Digital Library