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Sensor Development for the Large Synoptic Survey Telescope.
The Large Synoptic Survey project proposes to build an 8m-class ground-based telescope with a dedicated wide field camera. The camera consists of a large focal plane mosaic composed of multi-output CCDs with extended red response. Design considerations and preliminary characterization results for the sensors are presented in this contribution to the Workshop.
Date:
June 7, 2007
Creator:
O'Connor, P.; Radeka, V. & Takacs, P.
Object Type:
Article
System:
The UNT Digital Library
Effect of High Temperature Aging on the Corrosion Resistance of Iron Based Amorphous Alloys
None
Date:
June 7, 2007
Creator:
Day, S D; Haslam, J J; Farmer, J C & Rebak, R B
Object Type:
Article
System:
The UNT Digital Library
Interlayer Interaction and Electronic Screening in MultilayerGraphene
The unusual transport properties of graphene are the direct consequence of a peculiar bandstructure near the Dirac point. We determine the shape of the {pi} bands and their characteristic splitting, and find the transition from two-dimensional to bulk character for 1 to 4 layers of graphene by angle-resolved photoemission. By detailed measurements of the {pi} bands we derive the stacking order, layer-dependent electron potential, screening length and strength of interlayer interaction by comparison with tight binding calculations, yielding a comprehensive description of multilayer graphene's electronic structure.
Date:
June 7, 2007
Creator:
Ohta, Taisuke; Bostwick, Aaron; McChesney, J.L.; Seyller, Thomas; Horn, Karsten & Rotenberg, Eli
Object Type:
Article
System:
The UNT Digital Library
Design and Development of a 100 MVA HTS Generator for Commercial Entry
In 2002, General Electric and the US Department of Energy (DOE) entered into a cooperative agreement for the development of a commercialized 100 MVA generator using high temperature superconductors (HTS) in the field winding. The intent of the program was to: (1) identify and develop technologies that would be needed for such a generator; (2) develop conceptual designs for generators with ratings of 100 MVA and higher using HTS technology; (3) perform proof of concept tests at the 1.5 MW level for GE's proprietary warm iron rotor HTS generator concept; and (4) design, build, and test a prototype of a commercially viable 100 MVA generator that could be placed on the power grid. This report summarizes work performed during the program and is provided as one of the final program deliverables. The design for the HTS generator was based on GE's warm iron rotor concept in which a cold HTS coil is wound around a warm magnetic iron pole. This approach for rotating HTS electrical machinery provides the efficiency benefits of the HTS technology while addressing the two most important considerations for power generators in utility applications: cost and reliability. The warm iron rotor concept uses the least amount of …
Date:
June 7, 2007
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
EFFECTS OF ONE WEEK TRITIUM EXPOSURE ON EPDM ELASTOMER
This report documents test results for the exposure of four formulations of EPDM (ethylene-propylene diene monomer) elastomer to tritium gas at one atmosphere for approximately one week and characterization of material property changes and changes to the exposure gas during exposure. All EPDM samples were provided by Los Alamos National Laboratory (LANL). Material properties that were characterized include mass, sample dimensions, appearance, flexibility, and dynamic mechanical properties. The glass transition temperature was determined by analysis of the dynamic mechanical property data per ASTM standards. No change of glass transition temperature due to the short tritium gas exposure was observed. Filled and unfilled formulations of Dupont{reg_sign} Nordel{trademark} 1440 had a slightly higher glass transition temperature than filled and unfilled formulations of Uniroyal{reg_sign} Royalene{reg_sign} 580H; filled formulations had the same glass transition as unfilled. The exposed samples appeared the same as before exposure--there was no evidence of discoloration, and no residue on stainless steel spacers contacting the samples during exposure was observed. The exposed samples remained flexible--all formulations passed a break test without failing. The unique properties of polymers make them ideal for certain components in gas handling systems. Specifically, the resiliency of elastomers is ideal for sealing surfaces, for example in …
Date:
June 7, 2007
Creator:
Clark, E
Object Type:
Report
System:
The UNT Digital Library
Noncommutative Inspired Black Holes in Extra Dimensions
In a recent string theory motivated paper, Nicolini, Smailagic and Spallucci (NSS) presented an interesting model for a noncommutative inspired, Schwarzschild-like black hole solution in 4-dimensions. The essential effect of having noncommutative co-ordinates in this approach is to smear out matter distributions on a scale associated with the turn-on of noncommutativity which was taken to be near the 4-d Planck mass. In particular, NSS assumed that this smearing was essentially Gaussian. This energy scale is sufficiently large that in 4-d such effects may remain invisible indefinitely. Extra dimensional models which attempt to address the gauge hierarchy problem, however, allow for the possibility that the effective fundamental scale may not be far from {approx} 1 TeV, an energy regime that will soon be probed by experiments at both the LHC and ILC. In this paper we generalize the NSS model to the case where flat, toroidally compactified extra dimensions are accessible at the TeV-scale and examine the resulting modifications in black hole properties due to the existence of noncommutativity. We show that while many of the noncommutativity-induced black hole features found in 4-d by NSS persist, in some cases there can be significant modifications due the presence of extra dimensions. We …
Date:
June 7, 2006
Creator:
Rizzo, Thomas G.
Object Type:
Report
System:
The UNT Digital Library
Classification of non-coding RNA using graph representations ofsecondary structure
Some genes produce transcripts that function directly in regulatory, catalytic, or structural roles in the cell. These non-coding RNAs are prevalent in all living organisms, and methods that aid the understanding of their functional roles are essential. RNA secondary structure, the pattern of base-pairing, contains the critical information for determining the three dimensional structure and function of the molecule. In this work we examine whether the basic geometric and topological properties of secondary structure are sufficient to distinguish between RNA families in a learning framework. First, we develop a labeled dual graph representation of RNA secondary structure by adding biologically meaningful labels to the dual graphs proposed by Gan et al [1]. Next, we define a similarity measure directly on the labeled dual graphs using the recently developed marginalized kernels [2]. Using this similarity measure, we were able to train Support Vector Machine classifiers to distinguish RNAs of known families from random RNAs with similar statistics. For 22 of the 25 families tested, the classifier achieved better than 70% accuracy, with much higher accuracy rates for some families. Training a set of classifiers to automatically assign family labels to RNAs using a one vs. all multi-class scheme also yielded encouraging …
Date:
June 7, 2004
Creator:
Karklin, Yan; Meraz, Richard F. & Holbrook, Stephen R.
Object Type:
Article
System:
The UNT Digital Library
How Can We Test Seesaw Experimentally?
The seesaw mechanism for the small neutrino mass has been a popular paradigm, yet it has been believed that there is no way to test it experimentally. We present a conceivable outcome from future experiments that would convince us of the seesaw mechanism. It would involve a variety of data from LHC, ILC, cosmology, underground, and low-energy flavor violation experiments to establish the case.
Date:
June 7, 2006
Creator:
Buckley, Matthew R. & Murayama, Hitoshi
Object Type:
Article
System:
The UNT Digital Library
Nondestructive and Destructive Examination Studies on Removed-from-Service Control Rod Drive Mechanism Penetrations
Studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, focused on assessing the effectiveness of nondestructive examination (NDE) techniques for inspecting control rod drive mechanism (CRDM) nozzles and J-groove weldments. The primary objectives of this work are to provide information to the U.S. Nuclear Regulatory Commission (NRC) on the effectiveness of NDE methods as related to the in-service inspection of CRDM nozzles and J-groove weldments and to enhance the knowledge base of primary water stress corrosion cracking (PWSCC) through destructive characterization of the CRDM assemblies. Two CRDM assemblies were removed from service, decontaminated, and then used in a series of NDE and destructive examination (DE) measurements; this report addresses the following questions: 1) What did each NDE technique detect? 2) What did each NDE technique miss? 3) How accurately did each NDE technique characterize the detected flaws? 4) Why did the NDE techniques perform or not perform? Two CRDM assemblies including the CRDM nozzle, the J-groove weld, buttering, and a portion of the ferritic head material were selected for this study. This report focuses on a CRDM assembly that contained suspected PWSCC, based on in-service inspection data and through-wall leakage. The NDE measurements used to examine the …
Date:
June 7, 2007
Creator:
Cumblidge, Stephen E.; Crawford, Susan L.; Doctor, Steven R.; Seffens, Rob J.; Schuster, George J.; Toloczko, Mychailo B. et al.
Object Type:
Report
System:
The UNT Digital Library
Ionization Cooling using Parametric Resonances
Ionization Cooling using Parametric Resonances was an SBIR project begun in July 2004 and ended in January 2008 with Muons, Inc., (Dr. Rolland Johnson, PI), and Thomas Jefferson National Accelerator Facility (JLab) (Dr. Yaroslav Derbenev, Subcontract PI). The project was to develop the theory and simulations of Parametric-resonance Ionization Cooling (PIC) so that it could be used to provide the extra transverse cooling needed for muon colliders in order to relax the requirements on the proton driver, reduce the site boundary radiation, and provide a better environment for experiments. During the course of the project, the theoretical understanding of PIC was developed and a final exposition is ready for publication. Workshops were sponsored by Muons, Inc. in May and September of 2007 that were devoted to the PIC technique. One outcome of the workshops was the interesting and somewhat unexpected realization that the beam emittances using the PIC technique can get small enough that space charge forces can be important. A parallel effort to develop our G4beamline simulation program to include space charge effects was initiated to address this problem. A method of compensating for chromatic aberrations by employing synchrotron motion was developed and simulated. A method of compensating for …
Date:
June 7, 2008
Creator:
Johnson, Rolland P.
Object Type:
Report
System:
The UNT Digital Library
Crude-Oil Burner
Patent for a crude oil burner. Illustrations included.
Date:
June 7, 1910
Creator:
Shaeffer, Charles
Object Type:
Patent
System:
The Portal to Texas History
Adjustable Cultivator-Tooth Seat.
Patent for certain new and useful improvements in adjustable cultivator tooth seats, including instructions and illustrations.
Date:
June 7, 1898
Creator:
Shofield, James Drummond
Object Type:
Patent
System:
The Portal to Texas History
Burial Apparatus.
Patent for certain new and useful improvements in "a burial device adapted particularly for use as a cemetery hearse and also for depositing the casket in the grave" (line 12 - 15).
Date:
June 7, 1898
Creator:
Thorne, Richard Hamilton
Object Type:
Patent
System:
The Portal to Texas History
Cash-Fare-Slip Holder
Patent for a cash fare slip holder for use on train or trolley lines.
Date:
June 7, 1910
Creator:
Thomsen, Herman E.
Object Type:
Patent
System:
The Portal to Texas History
Cooperative sentry vehicles and differential GPS leapfrog
As part of a project for the Defense Advanced Research Projects Agency, Sandia National Laboratories Intelligent Systems and Robotics Center is developing and testing the feasibility of using a cooperative team of robotic sentry vehicles to guard a perimeter, perform a surround task, and travel extended distances. This paper describes the authors most recent activities. In particular, this paper highlights the development of a Differential Global Positioning System (DGPS) leapfrog capability that allows two or more vehicles to alternate sending DGPS corrections. Using this leapfrog technique, this paper shows that a group of autonomous vehicles can travel 22.68 kilometers with a root mean square positioning error of only 5 meters.
Date:
June 7, 2000
Creator:
Feddema, John T.; Lewis, Christopher L. & LaFarge, Robert A.
Object Type:
Article
System:
The UNT Digital Library
Silica control and materials tests at the Salton Sea geothermal field
The Lawrence Livermore Laboratory maintains and operates a test facility near Niland, California, in the Imperial Valley for field studies on SSGF brine chemistry, scale and solids control, materials, and injection. Recent work in silica control and materials testing is reviewed.
Date:
June 7, 1979
Creator:
Quong, R.; Harrar, J. E.; McCright, R. D.; Locke, R. D.; Lorensen, L. E. & Tardiff, G. E.
Object Type:
Article
System:
The UNT Digital Library
Praise enhancements to include general strain hardening exponents and mid-life residual stress and water chemistry changes
The purpose of this document is to describe some recent changes made to the PRAISE Code to provide some additional capabilities. The major changes are associated with the new capability to analyze cases where there is a mid-life change in residual stresses and/or water chemistry. Such changes have been proposed as a means of improving the reliability of BWR piping by reducing the oxygen content of the coolant (or other favorable chemistry changes) or altering the residual stresses near welds to provide a stress distribution less favorable to crack initiation and growth. Induction heating stress improvement (IHSI) and mechanical stress improvement process (MSIP) are considered, with the time at which the process is implemented defined by the user. As-welded residual stresses are considered to be present prior to the stress imrovement treatment. Improved pre- and post-processors were also developed and are described, which should be particularly useful to users of the PC version of PRAISE. In addition, improved J-integral solutions are incorporated that allow a treatment of general Ramberg-Osgood strain hardening, rather than the specific values of the strain hardening exponent included in earlier versions of the PRAISE Code. This document discusses only the new additions to the code and …
Date:
June 7, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Differencing asymptotic diffusion theory
A diffusion theory is presented which extends asymptotic diffusion to non-uniform material properties. Finite difference methods for the diffusion theory naturally result in jump conditions on interfaces when appropriate.
Date:
June 7, 1979
Creator:
Zimmerman, G.B.
Object Type:
Article
System:
The UNT Digital Library
Experimental attempt to achieve microstructure variations through temperature/time permutations for a nonwrought powder metallurgy uranium-6 niobium alloy
The powder metallurgical processing of uranium-6 niobium (U-6Nb) alloy has undergone 3 years of characterization at the Oak Ridge Y-12 Plant. The current structure of the powder metallurgy (P/M) alloy has been described as duplex: a mixture of two or more distinct grain sizes. An experiment was conducted to determine a gamma stabilizing heat treatment (time and temperature combination) to produce a structure consisting of one gamma grain size. Two heat treatments were found to produce an irregular ASTM 4 grain size. Additional P/M U-6Nb alloy material was hot pressed and characterized using the two new heat treatments; however, the resulting microstructures were size ASTM 8. Mechanical properties of the fine-grained P/M material were characterized. Continued evaluation of these results did not determine the cause of the grain refinement.
Date:
June 7, 1985
Creator:
Alexander-Morrison, G.M.
Object Type:
Report
System:
The UNT Digital Library
Inversion approach for thermal data from a convecting hydrothermal system. Revision 1
Hydrothermal systems are often studied by collecting thermal gradient data and temperature-depth curves. These data contain important information about the flow field, the evolution of the hydrothermal system, and the location and nature of the ultimate heat sources. Thermal data are conventionally interpreted by the ''forward'' method; the thermal field is calculated based on selected initial conditions and boundary conditions such as temperature and permeability distributions. If the calculated thermal field matches the data, the chosen conditions are inferred to be possibly correct. Because many sets of initial conditions may produce similar thermal fields, users of the ''forward'' method may inadvertently miss the correct set of initial conditions. Analytical methods for ''inverting'' data allow the determination of all the possible solutions consistent with the definition of the problem. In this paper the authors suggest an approach for inverting thermal data from a hydrothermal system, and compare it to the more conventional approach. The authors illustrate the difference in the methods by comparing their application to the Salton Sea Geothermal Field by Lau (1980a) and Kasameyer, et al. (1984). In this particular example, the inverse method was used to draw conclusions about the age and total rate of fluid flow into …
Date:
June 7, 1985
Creator:
Kasameyer, P.; Younker, L. & Hanson, J.
Object Type:
Article
System:
The UNT Digital Library
Particle physics and superstrings
Implications of recent precision measurements of the standard model gauge coupling constants are discussed in the context of superstring theory. 40 refs.
Date:
June 7, 1991
Creator:
Gaillard, M.K. (California Univ., Berkeley, CA (United States). Dept. of Physics Lawrence Berkeley Lab., CA (United States))
Object Type:
Article
System:
The UNT Digital Library
Pulse-power circuit diagnostics for the Nova laser
The Nova laser will have a large pulse power system for driving laser amplifiers, incorporating approximately 1600 flashlamp circuits. An automated system has been designed for diagnosing the condition of these flashlamp circuits. It records digitized circuit current waveforms and detects current excursions above a given threshold. In addition, it is able to fire flashlamps at a low energy to ascertain the health of the system. Data from this system can be ploted for inspection by the operator, analyzed by the computer system and archived for future reference.
Date:
June 7, 1982
Creator:
Christie, D. J.; Dallum, G. E.; Gritton, D. G.; Merritt, B. T.; Whitham, K. & Berkbigler, L. W.
Object Type:
Article
System:
The UNT Digital Library
The Boron-Carbon System: Final Technical Report, May 1, 1960 - April 30, 1961
Abstract: The boron-carbon equilibrium diagram has been determined by X-ray, metallographic, and thermal analysis of sintered and arc-cast alloys. A single carbide having a range of solubility from approximately 9 to 20 a/o carbon and melting congruently exists in the system. The terminal solubility of carbon in boron is 0.1-0.2a/o. The freezing reaction at the composition and melting temperature of elemental boron; there is a eutectic reaction at 29a/o carbon and 2375 degrees Celcius. No allotropy of boron was observed.
Date:
June 7, 1961
Creator:
Elliott, Rodney P.
Object Type:
Report
System:
The UNT Digital Library
Basic data for domestic supply wells in a five-mile radius of Tatum salt dome, Lamar County, Mississippi. A supplement to technical letter: Dribble-30. Technical letter: Dribble-38
None
Date:
June 7, 1963
Creator:
Taylor, R.E. & Grantham, P.E.
Object Type:
Report
System:
The UNT Digital Library