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Adapting Existing Spatial Data Sets to New Uses: An Example from Energy Modeling (open access)

Adapting Existing Spatial Data Sets to New Uses: An Example from Energy Modeling

Energy modeling and analysis often relies on data collected for other purposes such as census counts, atmospheric and air quality observations, and economic projections. These data are available at various spatial and temporal scales, which may be different from those needed by the energy modeling community. If the translation from the original format to the format required by the energy researcher is incorrect, then resulting models can produce misleading conclusions. This is of increasing importance, because of the fine resolution data required by models for new alternative energy sources such as wind and distributed generation. This paper addresses the matter by applying spatial statistical techniques which improve the usefulness of spatial data sets (maps) that do not initially meet the spatial and/or temporal requirements of energy models. In particular, we focus on (1) aggregation and disaggregation of spatial data, (2) imputing missing data and (3) merging spatial data sets.
Date: June 23, 2006
Creator: Johanesson, G; Stewart, J S; Barr, C; Sabeff, L B; George, R; Heimiller, D et al.
System: The UNT Digital Library
Accurate labeling of the light-actinide O4,5 ionization edges (open access)

Accurate labeling of the light-actinide O4,5 ionization edges

In this short article the accurate labeling of the O4,5 edges of the light actinides is addressed. The O4 and O5 edges are both contained in what is termed the ''giant resonance'' and the smaller ''pre-peak'' that is observed is a consequence of first-order perturbation by the 5d spin-orbit interaction. Thus, the small prepeak in the actinide 5d {yields} 5f transition should not be labeled the O5 peak, but rather the {Delta}S=1 peak.
Date: August 23, 2006
Creator: Moore, K & der Laan, G v
System: The UNT Digital Library
Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensemblesout-of-equilibrium (open access)

Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensemblesout-of-equilibrium

What is the best description that we can construct of athermodynamic system that is not in equilibrium, given only one, or afew, extra parameters over and above those needed for a description ofthe same system at equilibrium? Here, we argue the most appropriateadditional parameter is the non-equilibrium entropy of the system, andthat we should not attempt to estimate the probability distribution ofthe system, but rather the metaprobability (or hyperensemble) that thesystem is described by a particular probability distribution. The resultis an entropic distribution with two parameters, one a non-equilibriumtemperature, and the other a measure of distance from equilibrium. Thisdispersion parameter smoothly interpolates between certainty of acanonical distribution at equilibrium and great uncertainty as to theprobability distribution as we move away from equilibrium. We deducethat, in general, large, rare fluctuations become far more common as wemove away from equilibrium.
Date: February 23, 2006
Creator: Crooks, Gavin E.
System: The UNT Digital Library
Multipole Shimming of Permanent Magnets Using Harmonic CorrectorRings (open access)

Multipole Shimming of Permanent Magnets Using Harmonic CorrectorRings

Shimming systems are required to provide sufficient fieldhomogeneity for high resolution NMR. In certain specialized applications,such as rotating-field NMR and portable (ex-situ) NMR, permanentmagnet-based shimming systems can provide considerable advantages. Wepresent a simple two-dimensional shimming method based on harmoniccorrector rings which can provide arbitrary multipole order shimmingcorrections. Results demonstrate, for example, that quadrupolar ordershimming improves the linewidth by up to and order of magnitude. Anadditional order of magnitude reduction is in principle achievable byultilizing this shimming method for z-gradient correction and higherorder xy gradients.
Date: October 23, 2006
Creator: Jachmann, Rebecca C.; Trease, David R.; Bouchard, Louis-S.; Sakellariou, Dimitris; Martin, Rachel W.; Schlueter, Ross D. et al.
System: The UNT Digital Library
The Reactivity of Energetic Materials At Extreme Conditions (open access)

The Reactivity of Energetic Materials At Extreme Conditions

Energetic materials are unique for having a strong exothermic reactivity, which has made them desirable for both military and commercial applications. Energetic materials are commonly divided into high explosives, propellants, and pyrotechnics. We will focus on high explosive (HE) materials here, although there is a great deal of commonality between the classes of energetic materials. Although the history of HE materials is long, their condensed-phase properties are poorly understood. Understanding the condensed-phase properties of HE materials is important for determining stability and performance. Information regarding HE material properties (for example, the physical, chemical, and mechanical behaviors of the constituents in plastic-bonded explosive, or PBX, formulations) is necessary for efficiently building the next generation of explosives as the quest for more powerful energetic materials (in terms of energy per volume) moves forward. In modeling HE materials there is a need to better understand the physical, chemical, and mechanical behaviors from fundamental theoretical principles. Among the quantities of interest in plastic-bonded explosives (PBXs), for example, are thermodynamic stabilities, reaction kinetics, equilibrium transport coefficients, mechanical moduli, and interfacial properties between HE materials and the polymeric binders. These properties are needed (as functions of stress state and temperature) for the development of improved micro-mechanical …
Date: October 23, 2006
Creator: Fried, L E
System: The UNT Digital Library
Stark Tuning of Donor Electron Spins of Silicon (open access)

Stark Tuning of Donor Electron Spins of Silicon

We report Stark shift measurements for {sup 121}Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on top of a Sb-implanted {sup 28}Si epi-layer are used to apply electric fields. Two Stark effects are resolved: a decrease of the hyperfine coupling between electron and nuclear spins of the donor and a decrease in electron Zeeman g-factor. The hyperfine term prevails at X-band magnetic fields of 0.35T, while the g-factor term is expected to dominate at higher magnetic fields. A significant linear Stark effect is also resolved presumably arising from strain.
Date: March 23, 2006
Creator: Bradbury, Forrest R.; Tyryshkin, Alexei M.; Sabouret, Guillaume; Bokor, Jeff; Schenkel, Thomas & Lyon, Stephen A.
System: The UNT Digital Library
Modelling H-3 and C-14 transfer to farm animals and their products (open access)

Modelling H-3 and C-14 transfer to farm animals and their products

The radionuclides {sup 14}C and {sup 3}H may both be released from nuclear facilities. These radionuclides differ from most others in that they are isotopes of macro-elements which form the basis of animal tissues, feed and, in the case of {sup 3}H, water. There are few published values describing the transfer of {sup 3}H and {sup 14}C from feed to animal derived food products. Approaches are described which enable the prediction of {sup 14}C and {sup 3}H transfer parameter values from readily available information on the stable H or C concentration of animal feeds, tissues and milk, water turnover rates, and feed intakes and digestibilities. It is recommended that the concentration ratio between feed and animal product activity concentrations be used as it is less variable than the transfer coefficient (ratio between radionuclide activity concentration in animal milk or tissue to the daily intake of a radionuclide).
Date: June 23, 2006
Creator: Galeriu, D.; Melintescu, A.; Beresford, N.; Crout, N.; Peterson, R. & Takeda, H.
System: The UNT Digital Library
Laser light Backscatter from Intermediate and High Z plasmas (open access)

Laser light Backscatter from Intermediate and High Z plasmas

None
Date: February 23, 2006
Creator: Berger, R L; Constantin, C; Divol, L; Meezan, N; Froula, D H; Glenzer, S H et al.
System: The UNT Digital Library
On the work distribution for the adiabatic compression of a diluteclassical gas (open access)

On the work distribution for the adiabatic compression of a diluteclassical gas

We consider the adiabatic and quasi-static compression of adilute classical gas, confined in a piston and initially equilibratedwith a heat bath. We find that the work performed during this process isdescribed statistically by a gamma distribution. We use this result toshow that the model satisfies the non-equilibrium work and fluctuationtheorems, but not the fluctation-dissipation relation. We discuss therare but dominant realizations that contribute most to the exponentialaverage of the work, and relate our results to potentially universal workdistributions.
Date: February 23, 2006
Creator: Crooks, Gavin E. & Jarzynski, Christopher
System: The UNT Digital Library
Geometrically induced metastability and holography (open access)

Geometrically induced metastability and holography

We construct metastable configurations of branes and anti-branes wrapping 2-spheres inside local Calabi-Yau manifolds and study their large N duals. These duals are Calabi-Yau manifolds in which the wrapped 2-spheres have been replaced by 3-spheres with flux through them, and supersymmetry is spontaneously broken. The geometry of the non-supersymmetric vacuum is exactly calculable to all orders of the't Hooft parameter, and to the leading order in 1/N. The computation utilizes the same matrix model techniques that were used in the supersymmetric context. This provides a novel mechanism for breaking supersymmetry in the context of flux compactifications.
Date: October 23, 2006
Creator: Aganagic, Mina; Aganagic, Mina; Beem, Christopher; Seo, Jihye & Vafa, Cumrun
System: The UNT Digital Library
Evaluation of OGC Standards for Use in LLNL GIS (open access)

Evaluation of OGC Standards for Use in LLNL GIS

Over the summer of 2005, the Lawrence Livermore National Laboratory (LLNL) Computer Applications and Research Department conducted a small project that examined whether Open Geospatial Consortium (OGC) standards might be useful in meeting program mission requirements more effectively. OGC standards are intended to facilitate interoperability between geospatial processing systems to lower development costs and to avoid duplication of effort and vendor lock-in. Some OGC standards appear to be gaining traction in the geospatial data community, the Federal government, Department of Energy (DOE) and Department of Homeland Security (DHS) and so an evaluation was deemed appropriate.
Date: June 23, 2006
Creator: Walker, H; Chou, R M; Chubb, K K & Schek, J L
System: The UNT Digital Library
AN OVERVIEW OF THE SNS ACCELERATOR MECHANICAL ENGINEERING. (open access)

AN OVERVIEW OF THE SNS ACCELERATOR MECHANICAL ENGINEERING.

The Spallation Neutron Source (SNS*) is an accelerator-based neutron source currently nearing completion at Oak Ridge National Laboratory. When completed in 2006, the SNS will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. SNS is a collaborative effort between six U.S. Department of Energy national laboratories and offered a unique opportunity for the mechanical engineers to work with their peers from across the country. This paper presents an overview of the overall success of the collaboration concentrating on the accelerator ring mechanical engineering along with some discussion regarding the relative merits of such a collaborative approach. Also presented are a status of the mechanical engineering installation and a review of the associated installation costs.
Date: June 23, 2006
Creator: HSEUH, H.; LUDWIG, H.; MAHLER, G.; PAI, C.; PEARSON, C.; RANK, J. et al.
System: The UNT Digital Library
CRYSTALLINE BEAMS AT HIGH ENERGIES. (open access)

CRYSTALLINE BEAMS AT HIGH ENERGIES.

Previously it was shown that by crystallizing each of the two counter-circulating beams, a much larger beam-beam tune shift can be tolerated during the beam-beam collisions; thus a higher luminosity can be reached for colliding beams [1]. On the other hand, crystalline beams can only be formed at energies below the transition energy ({gamma}{sub T}) of the accelerators [2]. In this paper, we investigate the formation of crystals in a high-{gamma}{sub T} lattice that also satisfies the maintenance condition for a crystalline beam [3].
Date: June 23, 2006
Creator: WEI, J.; OKAMOTO, H.; YURI, Y.; SESSLER, A. & MACHIDA, S.
System: The UNT Digital Library
A Dramatically Reduced Size in the Gantry Design for the Proton-Carbon Therapy. (open access)

A Dramatically Reduced Size in the Gantry Design for the Proton-Carbon Therapy.

Gantries in the proton/carbon cancer therapy machines represent the major cost and are of the largest size. This report explains a new way to the gantry design. The size and cost of the gantries are reduced and their use is simplified by using the fixed magnetic field. The ''new'' gantry is made of a very large momentum acceptance non-scaling Fixed Field Alternating Gradient (FFAG) quarter and half arc beam lines. The gantry is made of combined function magnets with a very strong focusing and small dispersion function. Additional magnets with a fast response are required to allow adjustments of the beam position for different energies at the beginning of the gantry. Additional strong focusing magnets following the gantry have also to be adjustable to provide required spot size and radial scanning above the patients. The fixed field combined function magnets could be made of small permanent magnets for the proton machine, or of the high temperature superconductors or superconductors for the carbon machine, reducing dramatically the size.
Date: June 23, 2006
Creator: Trbojevic, D.; Gupta, R.; Parker, B.; Keil, E. & Sessler, A. M.
System: The UNT Digital Library
PASSIVITY BREAKDOWN AND EVOLUTION OF LOCALIZED CORROSION ON TYPE 316L STAINLESS STEEL (open access)

PASSIVITY BREAKDOWN AND EVOLUTION OF LOCALIZED CORROSION ON TYPE 316L STAINLESS STEEL

Passivity breakdown of 316L SS in the presence of aggressive Cl{sup -} and inhibitive NO{sub 3}{sup -} anions has been experimentally studied and the results have been interpreted in terms of the Point Defect Model (PDM). By introducing the competitive adsorption of Cl{sup -} and NO{sub 3}{sup -} into surface oxygen vacancies at the passive film/solution interface, the PDM yields a critical breakdown potential (V{sub c}) that is predicted to vary linearly with log[Cl{sup -}], or with log ([Cl{sup -}]/[NO{sub 3}{sup -}]) [1] when nitrate ions are present, which is shown in Fig. 1. The Point Defect Model also explains the fact that the slope of V{sub c} vs. log[Cl{sup -}] does not change in the presence of NO{sub 3}{sup -}, which is attributed to the quasi-equilibrium ejection of a cation from the barrier layer to form the vacancy pair V{sub M}V{sub O}{sup (2-{chi})} at the barrier layer/solution interface. The Point Defect Model predicts that measured V{sub c} increases linearly with the square root of voltage scan rate {nu}{sup 1/2} [1]. From this correlation, the critical, areal concentration of cation vacancies at the metal/barrier layer interface, {zeta}, has been estimated and found to be comparable to that calculated from the …
Date: October 23, 2006
Creator: S. Yang, G. Engelhardt, and D. D. Macdonald
System: The UNT Digital Library
Measurements of the Angle Alpha(Phi(2)) at BaBar (open access)

Measurements of the Angle Alpha(Phi(2)) at BaBar

None
Date: May 23, 2006
Creator: Emery, S. & /Saclay
System: The UNT Digital Library
Lattices for High-Power Proton Beam Acceleration and Secondary Beam Collection and Cooling. (open access)

Lattices for High-Power Proton Beam Acceleration and Secondary Beam Collection and Cooling.

Rapid cycling synchrotrons are used to accelerate high-intensity proton beams to energies of tens of GeV for secondary beam production. After primary beam collision with a target, the secondary beam can be collected, cooled, accelerated or decelerated by ancillary synchrotrons for various applications. In this paper, we first present a lattice for the main synchrotron. This lattice has: (a) flexible momentum compaction to avoid transition and to facilitate RF gymnastics (b) long straight sections for low-loss injection, extraction, and high-efficiency collimation (c) dispersion-free straights to avoid longitudinal-transverse coupling, and (d) momentum cleaning at locations of large dispersion with missing dipoles. Then, we present a lattice for a cooler ring for the secondary beam. The momentum compaction across half of this ring is near zero, while for the other half it is normal. Thus, bad mixing is minimized while good mixing is maintained for stochastic beam cooling.
Date: June 23, 2006
Creator: Wang, S.; Wei, J.; Brown, K.; Gardner, C.; Lee, Y. Y.; Lowenstein, D. et al.
System: The UNT Digital Library
Development of Nanofluidic Cells for Ultrafast X-ray Studies of Water (open access)

Development of Nanofluidic Cells for Ultrafast X-ray Studies of Water

In order to study the molecular structure and dynamics of liquid water with soft x-ray probes, samples with nanoscale dimensions are needed. This paper describes a simple method for preparing nanofluidic water cells. The idea is to confine a thin layer of water between two silicon nitride windows. The windows are 1 mm x 1 mm and 0.5 mm x 0.5 mm in size and have a thickness of 150 nm. The thickness of the water layer was measured experimentally by probing the infrared spectrum of water in the cells with a Fourier Transform InfraRed (FTIR) apparatus and from soft x-ray static measurements at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. Water layers ranging from 10 nm to more than 2 {micro}m were observed. Evidence for changes in the water structure compared to bulk water is observed in the ultrathin cells.
Date: August 23, 2006
Creator: Irizarry, Melvin E. & /Puerto Rico U., Mayaguez /SLAC
System: The UNT Digital Library
On the Feasibility of a Spin Decoherence Measurement. (open access)

On the Feasibility of a Spin Decoherence Measurement.

In this paper, I study the feasibility of making a turn-by-turn spin measurement to extract the spin tune from a polarized beam injected perpendicular to the stable spin direction. For the ideal case of a zero-emittance beam with no spin-tune spread, there would be no spin decoherence, and a measurement of the spin tune could easily be made by collecting turn-indexed polarization data over several million turns. However, in a real beam there is a momentum spread which provides a spin-tune spread. With a coasting beam the tune spread can cause decoherence of the spins resulting in a fast depolarization of the beam in as few as a thousand turns. With synchrotron oscillations the decoherence time can be greatly increased, so that a measurement becomes feasible with summation of the turn-by-turn data from a reasonable number of bunches ({approx}< 100). Three cases of 1, 2, and 2 1/2, Siberian snakes are considered. By using spin tune measurements for both the single and double snake cases, we could vastly improve the calibration of the optimum settings for the RHIC snakes.
Date: June 23, 2006
Creator: MacKay, W. W.
System: The UNT Digital Library
Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs (open access)

Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs

The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range 0.5 8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitted with shifted Maxwellian distributions. The results show that it is possible to obtain a plasma composition with a narrow charge-state distribution as well as a narrow IED. These data may enable tailoring thin-film properties through selecting growth conditions that are characterized by predefined charge state and energy distributions.
Date: March 23, 2006
Creator: Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil & Schneider, Jochen M.
System: The UNT Digital Library
Extraction System Design for the Bsns/Rcs. (open access)

Extraction System Design for the Bsns/Rcs.

The BSNS extraction system takes use one of the four dispersion-free straight sections. Five vertical kickers and one Lambertson septum magnet are used for the one-turn extraction. The rise time of less 250 ns and the total kicking angle of 20 mrad are required for the kickers that are grouped into two tanks. The design for the kicker magnets and the PFN is also given. To reduce the low beam loss in the extraction channels due to large halo emittance, large apertures are used for both the kickers and septum. Stray magnetic field inside and at the two ends of the circulating path of the Lambertson magnet and its effect to the beam has been studied.
Date: June 23, 2006
Creator: Wei, J.; Chen, Y.; Chi, Y. L.; Jiang, Y. L.; Kang, W.; Pang, J. B. et al.
System: The UNT Digital Library
Comment on ?Spin crossover in (Mg,Fe)O: A M?ssbauer effect study with an alternative interpretation of x-ray emission spectroscopy data? (open access)

Comment on ?Spin crossover in (Mg,Fe)O: A M?ssbauer effect study with an alternative interpretation of x-ray emission spectroscopy data?

Electronic spin-pairing transition of iron in magnesiow{umlt u}stite-(Mg,Fe)O has been recently studied with X-ray emission and M{umlt o}ssbauer spectroscopies under high pressures. While these studies reported a high-spin to low-spin transition of iron to occur at pressures above approximately 50 GPa, the width of the observed transition varies significantly. In particular, Kantor et al. reported that the transition in (Mg0.8,Fe0.2)O occurs over a pressure range of approximately 50 GPa in high-pressure M{umlt o}ssbauer measurements. To account for the discrepancy in the transition pressure, Kantor et al. reanalyzed the X-ray emission spectra by Lin et al. using a simple spectral decomposition method and claimed that X-ray emission measurements are also consistent with a spin crossover of iron at high pressures. Here we show that the proposed fitting method is inadequate to describe the X-ray emission spectrum of the low-spin FeS2 and would give an erroneous satellite peak (K{sub beta}') intensity, leading to an artificial high-spin component and, consequently, to invalid conclusions regarding the width of the pressure-induced transition in magnesiow{umlt u}stite. Furthermore, we compare Kantor's M{umlt o}ssbauer data with other recent high-pressure M{umlt o}ssbauer studies and show that the width of the transition can be simply explained by different experimental conditions …
Date: May 23, 2006
Creator: Lin, J.; Struzhkin, V. V. & Garriliuk, A.
System: The UNT Digital Library
The Challenges to Coupling Dynamic Geospatial Models (open access)

The Challenges to Coupling Dynamic Geospatial Models

Many applications of modeling spatial dynamic systems focus on a single system and a single process, ignoring the geographic and systemic context of the processes being modeled. A solution to this problem is the coupled modeling of spatial dynamic systems. Coupled modeling is challenging for both technical reasons, as well as conceptual reasons. This paper explores the benefits and challenges to coupling or linking spatial dynamic models, from loose coupling, where information transfer between models is done by hand, to tight coupling, where two (or more) models are merged as one. To illustrate the challenges, a coupled model of Urbanization and Wildfire Risk is presented. This model, called Vesta, was applied to the Santa Barbara, California region (using real geospatial data), where Urbanization and Wildfires occur and recur, respectively. The preliminary results of the model coupling illustrate that coupled modeling can lead to insight into the consequences of processes acting on their own.
Date: June 23, 2006
Creator: Goldstein, N
System: The UNT Digital Library
Single Particle Beam Dynamics Design of Bsns/Rcs. (open access)

Single Particle Beam Dynamics Design of Bsns/Rcs.

Rapid Cycling Synchrotron (RCS) is a key component of Beijing Spallation Neutron Source (BSNS). It accumulates and accelerates protons to design energy of 1.6 GeV, and extracts high energy beam to the target. As a high beam density and high beam power machine, low beam loss is also a basic requirement. An optimal lattice design is essential for the cost and the future operation. The lattice design of BSNS is presented, and the related dynamics issues are discussed. The injection/extraction scheme and the beam collimation system design are introduced.
Date: June 23, 2006
Creator: Wang, S.; Fang, S.-X.; Qin, Q.; Tang, J.-Y. & Wei, J.
System: The UNT Digital Library