Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site (open access)

Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site

Groundwater is sampled from 39 monitoring wells on the Nevada Test Site (NTS) as part of the Routine Radiological Environmental Monitoring Program. Many of these wells were not designed or constructed for long-term groundwater monitoring. Some have extensive completion zones and others have obstructions such as pumps and tubing. The high-volume submersible pumps in some wells are unsuitable for long-term monitoring and result in large volumes of water that may have to be contained and characterized before subsequent disposition. The configuration of most wells requires sampling stagnant well water with a wireline bailer. Although bailer sampling allows for the collection of depth-discrete samples, the collected samples may not be representative of local groundwater because no well purging is done. Low-maintenance, solar-powered jack pumps will be deployed in nine of these onsite monitoring wells to improve sample quality. These pumps provide the lift capacity to produce groundwater from the deep aquifers encountered in the arid environment of the NTS. The water depths in these wells range from 700 to 2,340 ft below ground surface. The considerable labor and electrical power requirements of electric submersible pumps are eliminated once these pumps are installed. Access tubing will be installed concurrent with the installation …
Date: May 3, 2007
Creator: David Hudson, Charles Lohrstorfer, Bruce Hurley
System: The UNT Digital Library
Tomographic wavefront correction for the LSST (open access)

Tomographic wavefront correction for the LSST

The Large Synoptic Survey Telescope (LSST) is a three mirror modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary followed by a 3-element refractive corrector producing a 3.5 degree field of view. This design produces image diameters of <0.3 arcsecond 80% encircled energy over its full field of view. The image quality of this design is sufficient to ensure that the final images produced by the telescope will be limited by the atmospheric seeing at an excellent astronomical site. In order to maintain this image quality, the deformations and rigid body motions of the three large mirrors must be actively controlled to minimize optical aberrations. By measuring the optical wavefront produced by the telescope at multiple points in the field, mirror deformations and rigid body motions that produce a good optical wavefront across the entire field may be determined. We will describe the details of the techniques for obtaining these solutions. We will show that, for the expected mirror deformations and rigid body misalignments, the solutions that are found using these techniques produce an image quality over the field that is close to optimal. We will discuss how many wavefront sensors are needed and the …
Date: May 3, 2006
Creator: Phillion, D. W.; Olivier, S. S.; Baker, K.; Seppala, L. & Hvisc, S.
System: The UNT Digital Library
Future Accelerator Challenges in Support of High-Energy Physics (open access)

Future Accelerator Challenges in Support of High-Energy Physics

Historically, progress in high-energy physics has largely been determined by development of more capable particle accelerators. This trend continues today with the imminent commissioning of the Large Hadron Collider at CERN, and the worldwide development effort toward the International Linear Collider. Looking ahead, there are two scientific areas ripe for further exploration--the energy frontier and the precision frontier. To explore the energy frontier, two approaches toward multi-TeV beams are being studied, an electron-positron linear collider based on a novel two-beam powering system (CLIC), and a Muon Collider. Work on the precision frontier involves accelerators with very high intensity, including a Super-BFactory and a muon-based Neutrino Factory. Without question, one of the most promising approaches is the development of muon-beam accelerators. Such machines have very high scientific potential, and would substantially advance the state-of-the-art in accelerator design. The challenges of the new generation of accelerators, and how these can be accommodated in the accelerator design, are described. To reap their scientific benefits, all of these frontier accelerators will require sophisticated instrumentation to characterize the beam and control it with unprecedented precision.
Date: May 3, 2008
Creator: Zisman, M. S.
System: The UNT Digital Library
ESTIMATING THE STRENGTH OF SINGLE-ENDED DISLOCATION SOURCES IN MICROMETER-SIZED SINGLE CRYSTALS (open access)

ESTIMATING THE STRENGTH OF SINGLE-ENDED DISLOCATION SOURCES IN MICROMETER-SIZED SINGLE CRYSTALS

A recent study indicated that the behavior of single-ended dislocation sources contributes to the flow strength of micrometer-scale crystals. In this study 3D discrete dislocation dynamics simulations of micrometer-sized volumes are used to calculate the effects of anisotropy of dislocation line tension (increasing Poisson's ratio, {nu}) on the strength of single-ended dislocation sources and, to compare them with the strength of double-ended sources of equal length. This is done by directly modeling their plastic response within a 1 micron cubed FCC Ni single crystal using DDS. In general, double-ended sources are stronger than single-ended sources of an equal length and exhibit no significant effects from truncating the long-range elastic fields at this scale. The double-ended source strength increases with Poisson ratio ({nu}), exhibiting an increase of about 50% at u = 0.38 (value for Ni) as compared to the value at {nu} = 0. Independent of dislocation line direction, for {nu} greater than 0.20, the strengths of single-ended sources depend upon the sense of the stress applied. The value for {alpha}, in the expression for strength, {tau} = {alpha}(L){micro}b/L is shown to vary from 0.4 to 0.84 depending upon the character of the dislocation and the direction of operation of …
Date: May 3, 2007
Creator: Rao, S I; Dimiduk, D M; Tang, M; Parthasarathy, T A; Uchic, M D & Woodward, C
System: The UNT Digital Library
Gated Microchannel Plate Photomultiplier For Longitudinal BeamDiagnostics (open access)

Gated Microchannel Plate Photomultiplier For Longitudinal BeamDiagnostics

A gated microchannel plate photomultiplier can be used as aneffective tool for measuring the longitudinal distribution of particlesaround most electron and high-energy proton rings. The broad availablewavelength range,low noise, and high sensitivity allow using such adevice for measuring the emitted synchrotron radiation and to extract thebeam intensity. The fast gate rise time can be used to reject strongsignals coming from filled RF buckets and avoid saturation of thephotocathode so that it is possible to monitor, with a high degree ofresolution, gaps in the machine fill and growth of parasitic bunches. Therugged characteristics of the device and its simplicity of use make itideal for all those applications where more complex and expensiveinstrumentation is not absolutely necessary. We present the experimentalresults obtained at the Advanced Light Source and on the Tevatron usingan Hamamatsu R5916U-50 series model.
Date: May 3, 2006
Creator: Byrd, John M.; De Santis, Stefano & Thurman-Keup, Randy
System: The UNT Digital Library
High-energy coherent THz radiation from laser wakefieldaccelerated ultrashort electron bunches (open access)

High-energy coherent THz radiation from laser wakefieldaccelerated ultrashort electron bunches

None
Date: May 3, 2004
Creator: van Tilborg, J.; Fubiani, G. J.; Geddes, C. G. R.; Toth, C.; Esarey, E.; Schroeder, C. B. et al.
System: The UNT Digital Library
Design of Spintronic Materials with Simple Structures (open access)

Design of Spintronic Materials with Simple Structures

A brief comparison of conventional electronics and spintronics is given. The key features of half metallic binary compounds with the zincblende structure are presented, using MnAs as an example. We discuss the interactions responsible for the half metallic properties. Special properties of superlattices and a digital ferromagnetic heterostructure incorporating zincblende half metals are also discussed.
Date: May 3, 2007
Creator: Fong, C Y; Qian, M C; Liu, K; Yang, L H & Pask, J E
System: The UNT Digital Library
Temporal changes in noble gas compositions within the Aidlinsector ofThe Geysers geothermal system (open access)

Temporal changes in noble gas compositions within the Aidlinsector ofThe Geysers geothermal system

The use of nonreactive isotopic tracers coupled to a full thermal-hydrological reservoir simulation allows for an improved method of investigating how reservoir fluids contained within matrix and fractures contribute over time to fluids produced from geothermal systems. A combined field and modeling study has been initiated to evaluate the effects of injection, production, and fracture-matrix interaction on produced noble gas contents and isotopic ratios. Gas samples collected periodically from the Aidlin steam field at The Geysers, California, between 1997 and 2006 have been analyzed for their noble gas compositions, and reveal systematic shifts in abundance and isotopic ratios over time. Because of the low concentrations of helium dissolved in the injection waters, the injectate itself has little impact on the helium isotopic composition of the reservoir fluids over time. However, the injection process may lead to fracturing of reservoir rocks and an increase in diffusion-controlled variations in noble gas compositions, related to gases derived from fluids within the rock matrix.
Date: May 3, 2006
Creator: Dobson, Patrick; Sonnenthal, Eric; Kennedy, Mack; van Soest,Thijs & Lewicki, Jennifer
System: The UNT Digital Library
Saturating interactions in /sup 4/He with density dependence (open access)

Saturating interactions in /sup 4/He with density dependence

With the advent of larger and faster computers, as well as modern shell model codes, nuclear structure calculations for the light nuclei (A<16) which include full 2/bar h/..omega.. model spaces are quite feasible. However, there can be serious problems in the mixing of 2/bar h/..omega.. and higher excitations into the low-lying spectra if the effective interaction is non-saturating. Furthermore, effective interactions which are both saturating and density dependent have not generally been used in previous nuclear structure calculations. Therefore, we have undertaken studies of /sup 4/He using two-body potential interactions which incorporate both saturation and density-dependence. Encouraging initial results in remedying the mixing of 0 and 2/bar h/..omega.. excitations have been obtained. We have also considered the effects of our interaction on the /sup 4/He compressibility and the centroid of the breathing mode strength. First indications are that a saturating effective interaction, with a short-range density dependent part and a long-range density independent part, comes close to matching crude predictions for the compressibility of /sup 4/He. 11 refs., 6 tabs.
Date: May 3, 1989
Creator: Bloom, S.D.; Resler, D.A. & Moszkowski, S.A.
System: The UNT Digital Library
High Resolution Spectrometer in studies of e/sup +/e/sup -/ annihilation at. sqrt. s = 29 GeV (open access)

High Resolution Spectrometer in studies of e/sup +/e/sup -/ annihilation at. sqrt. s = 29 GeV

The High Resolution Spectrometer is a general-purpose spectrometer which measures both charged particles and electromagnetic energy over 90% of the solid angle. The detection elements are in a 1.62-T magnetic field. The detector elements consist of a central drift chamber, an outer drift-chamber system, a barrel shower counter, and an end-cap shower-counter system. The goals of the program of research with the High Resolution Spectrometer include measurements of the electroweak coupling of the quarks and leptons, studies of the strong interactions of the quarks, and search for qualitatively new phenomena. 20 refs., 35 figs. (LEW)
Date: May 3, 1985
Creator: Derrick, M.
System: The UNT Digital Library
Fuel system and structural alloy considerations for space nuclear reactor systems (open access)

Fuel system and structural alloy considerations for space nuclear reactor systems

Sufficient data exist to provide a high level of confidence that refractory-alloy-clad ceramic fuel pins and refractory structural alloys can be used successfully in an operational space power system. However, data are not yet sufficient to ensure that these materials can meet the temperature, lifetime, and system mass envelope requirements for reliable operation of a 100 kW(e) system as specified by the SP-100 Project. Development efforts to provide these data are being initiated.
Date: May 3, 1981
Creator: Hoffman, E.E. & Cooper, R.H. Jr.
System: The UNT Digital Library
A Fast Online Event Display for a High Intensity Fixed-Target Spectrometer (open access)

A Fast Online Event Display for a High Intensity Fixed-Target Spectrometer

A workstation-based event display program for the Fermilab Tagged Photon Spectrometer (TPS) is described. Fast displays are required to monitor detector elements, observe hit patterns and energy deposition, and to check track reconstruction. Design considerations, novel features, and performance are designed. 5 refs., 4 figs., 1 tab.
Date: May 3, 1990
Creator: Napier, Austin
System: The UNT Digital Library
Experimental evaluation of vertically versus horizontally split yokes for SSC (Superconducting Super Collider) dipole magnets (open access)

Experimental evaluation of vertically versus horizontally split yokes for SSC (Superconducting Super Collider) dipole magnets

The yoke in SSC dipole magnets provides mechanical support to the collared coil as well as serving as a magnetic element. The yoke and skin are used to increase the coil prestress and reduce collar deflections under excitation. Yokes split on the vertical or horizontal mid-plane offer different advantages in meeting these objectives. To evaluate the relative merits of the two configuration a 1.8 m model dipole was assembled and tested first with horizontally split and then with vertically split yoke laminations. The magnet was extensively instrumented to measure azimuthal and axial stresses in the coil and the cold mass skin resulting from cooldown and excitation. Mechanical behavior of this magnet with each configuration is compared with that of other long and short models and with calculations. 13 refs., 5 figs.
Date: May 3, 1990
Creator: Strait, J.; Coulter, K.; Jaffery, T.; Kerby, J.; Koska, W. & Lamm, M.J.
System: The UNT Digital Library
A lattice gas model for thermohydrodynamics (open access)

A lattice gas model for thermohydrodynamics

The FHP lattice gas model is extended to include a temperature variable in order to study thermohydrodynamics. The compressible Navier-Stokes equations are derived using a Chapman-Enskog expansion. Heat conduction and convention problems are investigated, including Benard convention. It is shown that the usual FHP rescaling procedure can be avoided by controlling the temperature. 20 refs., 12 figs.
Date: May 3, 1990
Creator: Chen, Shiyi; Chen, Hudong; Doolen, G. D.; Gutman, S. & Lee, M.
System: The UNT Digital Library
Tritium in the World Trade Center September 11, 2001 Terrorist Attack: It's Possible Sources and Fate (open access)

Tritium in the World Trade Center September 11, 2001 Terrorist Attack: It's Possible Sources and Fate

Traces of tritiated water (HTO) were determined at World Trade Center (WTC) ground zero after the 9/11/01 terrorist attack. A method of ultralow-background liquid scintillation counting was used after distilling HTO from the samples. A water sample from the WTC sewer, collected on 9/13/01, contained 0.174{plus_minus}0.074 (2{sigma}) nCi/L of HTO. A split water sample, collected on 9/21/01 from the basement of WTC Building 6, contained 3.53{plus_minus}0.17 and 2.83{plus_minus}0.15 nCi/L, respectively. Several water and vegetation samples were analyzed from areas outside the ground zero, located in Manhattan, Brooklyn, Queens, and Kensico Reservoir. No HTO above the background was found in those samples. All these results are well below the levels of concern to human exposure. Several tritium radioluminescent (RL) devices were investigated as possible sources of the traces of tritium at ground zero. Tritium is used in self-luminescent emergency EXIT signs. No such signs were present inside the WTC buildings. However, it was determined that Boeing 767-222 aircraft operated by the United Airlines that hit WTC Tower 2 as well as Boeing 767-223ER operated by the American Airlines, that hit WTC Tower 1, had a combined 34.3 Ci of tritium at the time of impact. Other possible sources of tritium include …
Date: May 3, 2002
Creator: Parekh, P; Semkow, T; Husain, L; Haines, D; Woznial, G; Williams, P et al.
System: The UNT Digital Library
Iterative Algorithms for Ptychographic Phase Retrieval (open access)

Iterative Algorithms for Ptychographic Phase Retrieval

Ptychography promises diffraction limited resolution without the need for high resolution lenses. To achieve high resolution one has to solve the phase problem for many partially overlapping frames. Here we review some of the existing methods for solving ptychographic phase retrieval problem from a numerical analysis point of view, and propose alternative methods based on numerical optimization.
Date: May 3, 2011
Creator: Yang, Chao; Qian, Jianliang; Schirotzek, Andre; Maia, Filipe & Marchesini, Stefano
System: The UNT Digital Library
INFLUENCE OF FILM STRUCTURE AND LIGHT ON CHARGE TRAPPING AND DISSIPATION DYNAMICS IN SPUN-CAST ORGANIC THIN-FILM TRANSISTORS MEASURED BY SCANNING KELVIN PROBE MICROSCOPY (open access)

INFLUENCE OF FILM STRUCTURE AND LIGHT ON CHARGE TRAPPING AND DISSIPATION DYNAMICS IN SPUN-CAST ORGANIC THIN-FILM TRANSISTORS MEASURED BY SCANNING KELVIN PROBE MICROSCOPY

Herein, time-dependent scanning Kelvin probe microscopy of solution processed organic thin film transistors (OTFTs) reveals a correlation between film microstructure and OTFT device performance with the location of trapped charge within the device channel. The accumulation of the observed trapped charge is concurrent with the decrease in I{sub SD} during operation (V{sub G}=-40 V, V{sub SD}= -10 V). We discuss the charge trapping and dissipation dynamics as they relate to the film structure and show that application of light quickly dissipates the observed trapped charge.
Date: May 3, 2012
Creator: Teague, L.; Moth, M. & Anthony, J.
System: The UNT Digital Library
Proceedings of the international conference on liquid metal technology in energy production (open access)

Proceedings of the international conference on liquid metal technology in energy production

Each paper in the volume has been separately abstracted and indexed. (DG)
Date: May 3, 1976
Creator: Cooper, M. H.
System: The UNT Digital Library
A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid (open access)

A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.
Date: May 3, 2010
Creator: Arceo, Elena; Ellman, Jonathan & Bergman, Robert
System: The UNT Digital Library
Fermi Surface Evolution Across Multiple Charge Density Wave Transitions in ErTe3 (open access)

Fermi Surface Evolution Across Multiple Charge Density Wave Transitions in ErTe3

None
Date: May 3, 2010
Creator: Moore, R. G.
System: The UNT Digital Library
A new optical parametric amplifier based on lithium thioindate used for sum frequency generation vibrational spectroscopic studies of the Amide I mode of an interfacial model peptide (open access)

A new optical parametric amplifier based on lithium thioindate used for sum frequency generation vibrational spectroscopic studies of the Amide I mode of an interfacial model peptide

We describe a new optical parametric amplifier (OPA) that employs lithium thioindate, LiInS{sub 2} (LIS), to create tunable infrared light between 1500 cm{sup -1} and 2000 cm{sup -1}. The OPA based on LIS described within provides intense infrared light with a good beam profile relative to similar OPAs built on silver gallium sulfide, AgGaS{sub 2} (AGS), or silver gallium selenide, AgGaSe{sub 2} (AGSe). We have used the new LIS OPA to perform surface-specific sum frequency generation (SFG) vibrational spectroscopy of the amide I vibrational mode of a model peptide at the hydrophobic deuterated polystyrene (d{sub 8}-PS)-phosphate buffered saline interface. This model polypeptide (which is known to be an ?-helix in the bulk solution under the high ionic strength conditions employed here) contains hydrophobic leucyl (L) residues and hydrophilic lysyl (K) residues, with sequence Ac-LKKLLKLLKKLLKL-NH{sub 2}. The amide I mode at the d{sub 8}-PS-buffer interface was found to be centered around 1655 cm{sup -1}. This can be interpreted as the peptide having maintained its {alpha}-helical structure when adsorbed on the hydrophobic surface, although other interpretations are discussed.
Date: May 3, 2008
Creator: York, Roger L.; Holinga, George J.; Guyer, Dean R.; McCrea, Keith R.; Ward, Robert S. & Somorjai, Gabor A.
System: The UNT Digital Library
Information Booklet For FY91/FY92 Capital Project Validation Review (open access)

Information Booklet For FY91/FY92 Capital Project Validation Review

None
Date: May 3, 1989
Creator: unknown
System: The UNT Digital Library
Neutron Spectral Brightness of Cold Guide 4 at the High Flux Isotope Reactor (open access)

Neutron Spectral Brightness of Cold Guide 4 at the High Flux Isotope Reactor

The High Flux Isotope Reactor resumed operation in June of 2007 with a super-critical hydrogen cold source in horizontal beam tube 4. Cold guide 4 is a guide system designed to deliver neutrons from this source at reasonable flux at wavelengths greater than 4 Å to several instruments, and includes a 15-m, 96-section, 4-channel bender. A time-of-flight spectrum with calibrated detector was recorded at port C of cold guide 4, and compared to McStas simulations, to generate a brightness spectrum.
Date: May 3, 2009
Creator: Winn, B. L.; Robertson, J. L.; Iverson, E. B. & Selby, D. L.
System: The UNT Digital Library
The hierarchy of multiple many-body interaction scales in high-temperature superconductors (open access)

The hierarchy of multiple many-body interaction scales in high-temperature superconductors

To date, angle-resolved photoemission spectroscopy has been successful in identifying energy scales of the many-body interactions in correlated materials, focused on binding energies of up to a few hundred meV below the Fermi energy. Here, at higher energy scale, we present improved experimental data from four families of high-T{sub c} superconductors over a wide doping range that reveal a hierarchy of many-body interaction scales focused on: the low energy anomaly ('kink') of 0.03-0.09eV, a high energy anomaly of 0.3-0.5eV, and an anomalous enhancement of the width of the LDA-based CuO{sub 2} band extending to energies of {approx} 2 eV. Besides their universal behavior over the families, we find that all of these three dispersion anomalies also show clear doping dependence over the doping range presented.
Date: May 3, 2010
Creator: Meevasana, W.
System: The UNT Digital Library