Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds. (open access)

Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds.

Recent in situ observations in stratiform clouds suggest that mixed phase regimes, here defined as limited cloud volumes containing both liquid and solid water, are constrained to narrow layers (order 100 m) separating all-liquid and fully glaciated volumes (Hallett and Viddaurre, 2005). The Department of Energy Atmospheric Radiation Measurement Program's (DOE-ARM, Ackerman and Stokes, 2003) North Slope of Alaska (NSA) ARM Climate Research Facility (ACRF) recently started collecting routine measurement of radar Doppler velocity power spectra from the Millimeter Cloud Radar (MMCR). Shupe et al. (2004) showed that Doppler spectra has potential to separate the contributions to the total reflectivity of the liquid and solid water in the radar volume, and thus to investigate further Hallett and Viddaurre's findings. The Mixed-Phase Arctic Cloud Experiment (MPACE) was conducted along the NSA to investigate the properties of Arctic mixed phase clouds (Verlinde et al., 2006). We present surface based remote sensing data from MPACE to discuss the fine-scale structure of the mixed-phase clouds observed during this experiment.
Date: July 10, 2006
Creator: Rambukkange,M.; Verlinde, J.; Elorante, E.; Luke, E.; Kollias, P. & Shupe, M.
Object Type: Article
System: The UNT Digital Library
Chemical imaging of biological materials by NanoSIMS using isotopic and elemental labels (open access)

Chemical imaging of biological materials by NanoSIMS using isotopic and elemental labels

The NanoSIMS 50 combines unprecedented spatial resolution (as good as 50 nm) with ultra-high sensitivity (minimum detection limit of {approx}200 atoms). The NanoSIMS 50 incorporates an array of detectors, enabling simultaneous collection of 5 species originating from the same sputtered volume of a sample. The primary ion beam (Cs{sup +} or O{sup -}) can be scanned across the sample to produce quantitative secondary ion images. This capability for multiple isotope imaging with high spatial resolution provides a novel new approach to the study of biological materials. Studies can be made of sub-regions of tissues, mammalian cells, and bacteria. Major, minor and trace element distributions can be mapped on a submicron scale, growth and metabolism can be tracked using stable isotope labels, and biogenic origin can be determined based on composition. We have applied this technique extensively to mammalian and prokaryotic cells and bacterial spores. The NanoSIMS technology enables the researcher to interrogate the fate of molecules of interest within cells and organs through elemental and isotopic labeling. Biological applications at LLNL will be discussed.
Date: April 10, 2006
Creator: Weber, P K; Fallon, S J; Pett-Ridge, J; Ghosal, S & Hutcheon, I D
Object Type: Article
System: The UNT Digital Library
A review of the properties of Nb3Sn and their variation with A15composition, morphology and strain state (open access)

A review of the properties of Nb3Sn and their variation with A15composition, morphology and strain state

None
Date: November 10, 2006
Creator: Godeke, Arno
Object Type: Article
System: The UNT Digital Library
Probing Dark Energy via Neutrino and Supernova Observatories (open access)

Probing Dark Energy via Neutrino and Supernova Observatories

A novel method for extracting cosmological evolution parameters is proposed, using a probe other than light: future observations of the diffuse anti-neutrino flux emitted from core-collapse supernovae (SNe), combined with the SN rate extracted from future SN surveys. The relic SN neutrino differential flux can be extracted by using future neutrino detectors such as Gadolinium-enriched, megaton, water detectors or 100-kiloton detectors of liquid Argon or liquid scintillator. The core-collapse SN rate can be reconstructed from direct observation of SN explosions using future precision observatories. Our method, by itself, cannot compete with the accuracy of the optical-based measurements but may serve as an important consistency check as well as a source of complementary information. The proposal does not require construction of a dedicated experiment, but rather relies on future experiments proposed for other purposes.
Date: July 10, 2006
Creator: Hall, Lawrence; Hall, Lawrence J.; Murayama, Hitoshi; Papucci, Michele & Perez, Gilad
Object Type: Report
System: The UNT Digital Library
Diffusion through Carbon Nanotube Semipermeable membranes (open access)

Diffusion through Carbon Nanotube Semipermeable membranes

None
Date: February 10, 2006
Creator: Bakajin, O
Object Type: Report
System: The UNT Digital Library
Power Corrections in Charmless Nonleptonic B Decays: Annihilationis Factorizable and Real (open access)

Power Corrections in Charmless Nonleptonic B Decays: Annihilationis Factorizable and Real

We classify {Lambda}{sub QCD}/m{sub b} power corrections to nonleptonic B {yields} M{sub 1}M{sub 2} decays, where M{sub 1,2} are charmless non-isosinglet mesons. Using recent developments in soft-collinear effective theory, we prove that the leading contributions to annihilation amplitudes of order {alpha}{sub s}(m{sub b}) {Lambda}{sub QCD}/m{sub b} are real. The leading annihilation amplitudes depend on twist-2 and the twist-3 three parton distributions. A complex nonperturbative parameter from annihilation first appears at {Omega}[{alpha}{sub s}{sup 2}({radical}{Lambda}m{sub b}){Lambda}{sub QCD}/m{sub b}]. 'Chirally enhanced' contributions are also factorizable and real at lowest order. Thus, incalculable strong phases are suppressed in annihilation amplitudes, unless the {alpha}{sub s}({radical}{Lambda}m{sub b}) expansion breaks down. Modeling the distribution functions, we find that (11 {+-} 9)% and (15 {+-} 11)% of the absolute values of the measured {bar B}{sup 0} {yields} K{sup -}{pi}{sup +} and B{sup -} {yields} K{sup -}K{sup 0} penguin amplitudes come from annihilation. This is consistent with the expected size of power corrections.
Date: October 10, 2006
Creator: Arnesen, Christian M.; Ligeti, Zoltan; Rothstein, Ira Z. & Stewart, Iain W.
Object Type: Article
System: The UNT Digital Library
Characterization of chemical bonding in low-k dielectric materialsfor interconnect isolation: a xas and eels study (open access)

Characterization of chemical bonding in low-k dielectric materialsfor interconnect isolation: a xas and eels study

The use of low dielectric constant materials in the on-chipinterconnect process reduces interconnect delay, power dissipation andcrosstalk noise. To achieve the requirements of the ITRS for 2007-2009minimal sidewall damage from etch, ash or cleans is required. In chemicalvapor deposited (CVD) organo-silicate glass (OSG) which are used asintermetal dielectric (IMD) materials the substitution of oxygen in SiO2by methyl groups (-CH3) reduces the permittivity significantly (from 4.0in SiO2 to 2.6-3.3 in the OSG), since the electronic polarizability islower for Si-C bonds than for Si-O bonds. However, plasma processing forresist stripping, trench etching and post-etch cleaning removes C and Hcontaining molecular groups from the near-surface layer of OSG.Therefore, compositional analysis and chemical bonding characterizationof structured IMD films with nanometer resolution is necessary forprocess optimization. OSG thin films as-deposited and after plasmatreatment are studied using X-ray absorption spectroscopy (XAS) andelectron energy loss spectroscopy (EELS). In both techniques, the finestructure near the C1s absorption or energy loss edge, respectively,allows to identify C-H, C-C, and C-O bonds. This gives the opportunity todifferentiate between individual low-k materials and their modifications.The O1s signal is less selective to individual bonds. XAS spectra havebeen recorded for non-patterned films and EELS spectra for patternedstructures. The chemical bonding is compared for as-deposited …
Date: April 10, 2006
Creator: Hoffmann, P.; Schmeisser, D.; Engelmann, H. J.; Zschech, E.; Stegmann, H.; Himpsel, F. et al.
Object Type: Article
System: The UNT Digital Library
Gel Electrophoresis of Gold-DNA Nano-Conjugates (open access)

Gel Electrophoresis of Gold-DNA Nano-Conjugates

Single stranded DNA of different lengths and different amounts was attached to colloidal phosphine stabilized Au nanoparticles. The resulting conjugates were investigated in detail by a gel electrophoresis study based on 1200 gels. We demonstrate how these experiments help to understand the binding of DNA to Au particles. In particular we compare specific attachment of DNA via gold-thiol bonds with nonspecific adsorption of DNA. The maximum number of DNA molecules that can be bound per particle was determined. We also compare several methods to used gel electrophoresis for investigating the effective diameter of DNA-Au conjugates, such as using a calibration curve of particles with known diameters and Ferguson plots.
Date: January 10, 2006
Creator: Pellegrino, T.; Sperling, R. A.; Alivisatos, A. P. & Parak, W. J.
Object Type: Article
System: The UNT Digital Library
Gas Storage Technology Consortium (open access)

Gas Storage Technology Consortium

Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services, and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet (TCF) over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is critical in meeting the needs of these new markets. In order to address the gas storage needs of the natural gas industry, an industry-driven consortium was created--the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance operational flexibility and deliverability of the Nation's gas storage system, and provide a …
Date: May 10, 2006
Creator: Morrison, Joel L. & Elder, Sharon L.
Object Type: Report
System: The UNT Digital Library
The use of bulk states to accelerate the band edge statecalculation of a semiconductor quantum dot (open access)

The use of bulk states to accelerate the band edge statecalculation of a semiconductor quantum dot

We present a new technique to accelerate the convergence of the folded spectrum method in empirical pseudopotential band edge state calculations for colloidal quantum dots. We use bulk band states of the materials constituent of the quantum dot to construct initial vectors and a preconditioner. We apply these to accelerate the convergence of the folded spectrum method for the interior states at the top of the valence and the bottom of the conduction band. For large CdSe quantum dots, the number of iteration steps until convergence decreases by about a factor of 4 compared to previous calculations.
Date: May 10, 2006
Creator: Vomel, Christof; Tomov, Stanimire Z.; Wang, Lin-Wang; Marques,Osni A. & Dongarra, Jack J.
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for the 100-D-9 Boiler Fuel Oil Tank Site, Waste Site Reclassification Form 2006-030 (open access)

Remaining Sites Verification Package for the 100-D-9 Boiler Fuel Oil Tank Site, Waste Site Reclassification Form 2006-030

The 100-D-9 site is the former location of an underground storage tank used for holding fuel for the 184-DA Boiler House. Results of soil-gas samples taken from six soil-gas probes in a rectangle around the site the tank had been removed from concluded that there were no volatile organic compounds at detectable levels in the area. The 100-D-9 Boiler Fuel Oil Tank Site meets the remedial action objectives specified in the Remaining Sites ROD. The results demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: August 10, 2006
Creator: Dittmer, L. M.
Object Type: Report
System: The UNT Digital Library
Design and Application of an Electronic Logbook for Space System Integration and Test Operations (open access)

Design and Application of an Electronic Logbook for Space System Integration and Test Operations

In the highly technological aerospace world paper is still widely used to document space system integration and test (I&T) operations. E-Logbook is a new technology designed to substitute the most commonly used paper logbooks in space system I&T, such as the connector mate/demate logbook, the flight hardware and flight software component installation logbook, the material mix record logbook and the electronic ground support equipment validation logbook. It also includes new logbook concepts, such as the shift logbook, which optimizes management oversight and the shift hand-over process, and the configuration logbook, which instantly reports on the global I&T state of the space system before major test events or project reviews. The design of E-Logbook focuses not only on a reliable and efficient relational database, but also on an ergonomic human-computer interactive (HCI) system that can help reduce human error and improve I&T management and oversight overall. E-Logbook has been used for the I&T operation of the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) at the Stanford Linear Accelerator Center (SLAC). More than 41,000 records have been created for the different I&T logbooks, with no data having been corrupted or critically lost. 94% of the operators and 100% of …
Date: October 10, 2006
Creator: Kavelaars, Alicia T. & /SLAC /Stanford U., Dept. Aeronaut. Astronaut.
Object Type: Report
System: The UNT Digital Library
MODIFIED BOROHYDRIDES FOR REVERSIBLE HYDROGEN STORAGE (open access)

MODIFIED BOROHYDRIDES FOR REVERSIBLE HYDROGEN STORAGE

This paper reports the results in the effort to destabilize lithium borohydride for reversible hydrogen storage. A number of metals, metal hydrides, metal chlorides and complex hydrides were selected and evaluated as the destabilization agents for reducing dehydriding temperature and generating dehydriding-rehydriding reversibility. It is found that some additives are effective. The Raman spectroscopic analysis shows the change of B-H binding nature.
Date: May 10, 2006
Creator: Au, Ming
Object Type: Article
System: The UNT Digital Library
Bottom-up, decision support system development : a wetlandsalinity management application in California's San Joaquin Valley (open access)

Bottom-up, decision support system development : a wetlandsalinity management application in California's San Joaquin Valley

Seasonally managed wetlands in the Grasslands Basin ofCalifornia's San Joaquin Valley provide food and shelter for migratorywildfowl during winter months and sport for waterfowl hunters during theannual duck season. Surface water supply to these wetland contain saltwhich, when drained to the San Joaquin River during the annual drawdownperiod, negatively impacts downstream agricultural riparian waterdiverters. Recent environmental regulation, limiting discharges salinityto the San Joaquin River and primarily targeting agricultural non-pointsources, now addresses return flows from seasonally managed wetlands.Real-time water quality management has been advocated as a means ofmatching wetland return flows to the assimilative capacity of the SanJoaquin River. Past attempts to build environmental monitoring anddecision support systems to implement this concept have failed forreasons that are discussed in this paper. These reasons are discussed inthe context of more general challenges facing the successfulimplementation of environmental monitoring, modelling and decisionsupport systems. The paper then provides details of a current researchand development project which will ultimately provide wetland managerswith the means of matching salt exports with the available assimilativecapacity of the San Joaquin River, when fully implemented. Manipulationof the traditional wetland drawdown comes at a potential cost to thesustainability of optimal wetland moist soil plant habitat in thesewetlands - hence the project …
Date: May 10, 2006
Creator: Quinn, Nigel W.T.
Object Type: Article
System: The UNT Digital Library
Continuous active-source seismic monitoring of CO2 injection in abrine aquifer (open access)

Continuous active-source seismic monitoring of CO2 injection in abrine aquifer

Continuous crosswell seismic monitoring of a small-scale CO2injection was accomplished with the development of a noveltubing-deployed piezoelectric borehole source. This piezotube source wasdeployed on the CO2 injection tubing, near the top of the saline aquiferreservoir at 1657-m depth, and allowed acquisition of crosswellrecordings at 15-minute intervals during the multiday injection. Thechange in traveltime recorded at various depths in a nearby observationwell allowed hour-by-hour monitoring of the growing CO2 plume via theinduced seismic velocity change. Traveltime changes of 0.2 to 1.0 ms ( upto 8 percent ) were observed, with no change seen at control sensorsplaced above the reservoir. The traveltime measurements indicate that theCO2 plume reached the top of the reservoir sand before reaching theobservation well, where regular fluid sampling was occuring during theinjection, thus providing information about the in situ buoyancy ofCO2.
Date: December 10, 2006
Creator: Daley, Thomas M.; Solbau, Ray D.; Ajo-Franklin, Jonathan B. & Benson, Sally M.
Object Type: Article
System: The UNT Digital Library
THRESHOLD RESUMMATION FOR HIGGS PRODUCTION IN EFFECTIVE FIELD THEORY. (open access)

THRESHOLD RESUMMATION FOR HIGGS PRODUCTION IN EFFECTIVE FIELD THEORY.

None
Date: May 10, 2006
Creator: YUAN, F.
Object Type: Article
System: The UNT Digital Library
Documentation of Naval Reactors Papers and Presentations for the Space Technology and International Forum (STAIF) 2006 (open access)

Documentation of Naval Reactors Papers and Presentations for the Space Technology and International Forum (STAIF) 2006

None
Date: April 10, 2006
Creator: Ashcroft, JM
Object Type: Report
System: The UNT Digital Library
Hydrogeologic Assessment of the 4-S Land and Cattle CompanyRanch (open access)

Hydrogeologic Assessment of the 4-S Land and Cattle CompanyRanch

Hydrogeological assessment of the 4-S Land and Cattle Company (4-S Ranch) was conducted using a combination of field investigations and a survey of available literature from nearby agricultural water districts and other entities. The 4-S Ranch has been able to meet most of its own water needs providing irrigated pasture for beef cattle by an active program of shallow groundwater pumping in these miconfined aquifer above the Corcoran Clay. Comparison of groundwater pumping on the 4-S Ranch property with groundwater pumping in the adjacent Merquin and Stevinson Water Districts shows great similarity in the well screened depths and the quality of the groundwater produced by the well fields. The pump yield for the eight active production wells on the 4-S property are comparable to the production and drainage wells in the adjacent water districts. Like these Districts the 4-S Ranch lies close to the Valley trough in a historic discharge area. The 4-S Ranch is unique in that it is bounded and bisected by several major water conveyance facilities including Bear Creek. Although the large number of potential recharge structures would suggest significant groundwater conjunctive use potential the major well field development has occurred along the length of the Eastside …
Date: April 10, 2006
Creator: Quinn, Nigel W.T.
Object Type: Report
System: The UNT Digital Library
Enabling Science and Technology Computation Directorate 2005 Annual Report (open access)

Enabling Science and Technology Computation Directorate 2005 Annual Report

None
Date: March 10, 2006
Creator: Anderson, S R; Zosel, M E & Miller, M C
Object Type: Report
System: The UNT Digital Library
Brilliant Sm, Eu, Tb and Dy chiral lanthanide complexes withstrong circularly polarized luminescence (open access)

Brilliant Sm, Eu, Tb and Dy chiral lanthanide complexes withstrong circularly polarized luminescence

The synthesis, characterization and luminescent behavior of trivalent Sm, Eu, Dy and Tb complexes of two enantiomeric, octadentate, chiral, 2-hydroxyisophthalamide ligands are reported. These complexes are highly luminescent in solution. Functionalization of the achiral parent ligand with a chiral 1-phenylethylamine substituent on the open face of the complex in close proximity to the metal center yields complexes with strong circularly polarized luminescence (CPL) activity. This appears to be the first example of a system utilizing the same ligand architecture to sensitize four different lanthanide cations and display CPL activity. The luminescence dissymmetry factor, g{sub lum}, recorded for the Eu(III) complex is one of the highest values reported, and this is the first time the CPL effect has been demonstrated for a Sm(III) complex with a chiral ligand. The combination of high luminescence intensity with CPL activity should enable new bioanalytical applications of macromolecules in chiral environments.
Date: July 10, 2006
Creator: Petoud, Stephane; Muller, Gilles; Moore, Evan G.; Xu, Jide; Sokolnicki, Jurek; Riehl, James P. et al.
Object Type: Article
System: The UNT Digital Library
Cleanup Verification Package for the 618-8 Burial Ground (open access)

Cleanup Verification Package for the 618-8 Burial Ground

This cleanup verification package documents completion of remedial action for the 618-8 Burial Ground, also referred to as the Solid Waste Burial Ground No. 8, 318-8, and the Early Solid Waste Burial Ground. During its period of operation, the 618-8 site is speculated to have been used to bury uranium-contaminated waste derived from fuel manufacturing, and construction debris from the remodeling of the 313 Building.
Date: August 10, 2006
Creator: Appel, M. J.
Object Type: Report
System: The UNT Digital Library
Multiple-code benchmark simulation study of coupled THMC processesin the excavation disturbed zone associated with geological nuclear wasterepositories (open access)

Multiple-code benchmark simulation study of coupled THMC processesin the excavation disturbed zone associated with geological nuclear wasterepositories

An international, multiple-code benchmark test (BMT) studyis being conducted within the international DECOVALEX project to analysecoupled thermal, hydrological, mechanical and chemical (THMC) processesin the excavation disturbed zone (EDZ) around emplacement drifts of anuclear waste repository. This BMT focuses on mechanical responses andlong-term chemo-mechanical effects that may lead to changes in mechanicaland hydrological properties in the EDZ. This includes time-de-pendentprocesses such as creep, and subcritical crack, or healing of fracturesthat might cause "weakening" or "hardening" of the rock over the longterm. Five research teams are studying this BMT using a wide range ofmodel approaches, including boundary element, finite element, and finitedifference, particle mechanics, and elasto-plastic cellular automatamethods. This paper describes the definition of the problem andpreliminary simulation results for the initial model inception part, inwhich time dependent effects are not yet included.
Date: May 10, 2006
Creator: Rutqvist, J.; Feng, X. T.; Hudson, J.; Jing, L.; Kobayashi, A.; Koyama, T. et al.
Object Type: Article
System: The UNT Digital Library
Solid Target Studies for Muon Colliders And Neutrino Beams (open access)

Solid Target Studies for Muon Colliders And Neutrino Beams

This paper presents preliminary results from an ongoing post-irradiation analysis of materials that have been irradiated at the Brookhaven National Laboratory (BNL) Isotope facility. The effort is part of an experimental study that focuses on how prone to irradiation damage these materials are and thus what is their potential in playing the role of high power targets in the neutrino superbeam and the muon collider initiatives.
Date: May 10, 2006
Creator: Simos, N.; Kirk, H.; Ludewig, H.; Thieberger, P.; Weng, W. T.; Trung, P. T. et al.
Object Type: Article
System: The UNT Digital Library
Why every national deep-geological-isolation program needs a long-term science & technology component (open access)

Why every national deep-geological-isolation program needs a long-term science & technology component

The objective of this paper is to set down the rationale for a separate Science & Technology (S&T) Program within every national deep-geological-isolation program. The fundamental rationale for such a Program is to provide a dedicated focus for longer-term science and technology activities that ultimately will benefit the whole repository mission. Such a Program, separately funded and with a dedicated staff (separate from the ''mainline'' activities to develop the repository, the surface facilities, and the transportation system), can devote itself exclusively to the development and management of a long-term science and technology program. Broad experience in governments worldwide has demonstrated that line offices are unlikely to be able to develop and sustain both the appropriate longer-term philosophy and the specialized skills associated with managing longer-term science and technology projects. Accomplishing both of these requires a separate dedicated program office with its own staff.
Date: February 10, 2006
Creator: Budnitz, R J
Object Type: Article
System: The UNT Digital Library