Investigation of the amorphous to crystalline phase transition of chemical solution deposited Pb(Zr30Ti70)O3 thin films by soft x-ray absorption and soft x-ray emission spectroscopy (open access)

Investigation of the amorphous to crystalline phase transition of chemical solution deposited Pb(Zr30Ti70)O3 thin films by soft x-ray absorption and soft x-ray emission spectroscopy

Chemical solution deposited (CSD) complex oxide thin films attract considerable interest in various emerging fields as for example, fuel cells, ferroelectric random access memories or coated conductors. In the present paper the results of soft-x-ray spectroscopy between 100 eV and 500 eV on the amorphous to crystalline phase transition of ferroelectric PbZr{sub 0.3}Ti{sub 0.7}O{sub 3} (PZT) thin films are presented. Five CSD samples derived from the same wafer coated with a PZT film pyrolyzed at 350 C were heat treated at different temperatures between 400 C and 700 C. At first the sample were morphologically and electrically characterized. Subsequently the soft-x-ray absorption and emission experiments were performed at the undulator beamline 8.0 of the Advanced Light Source of the Lawrence Berkeley National Laboratory. Soft-x-ray absorption spectra were acquired for the Ti L{sub 2,3-}, O K-, and C K-edge thresholds by using simultaneously the total electron yield (TEY) and total fluorescence yield (TFY) detection methods. For two samples, annealed at 400 C and 700 C, respectively, the resonant inelastic soft-x-ray spectroscopy (RIXS) was applied for various excitation energies near the Ti L-, O K-edges. We observed clear evidence of a rutile phase at untypically low temperatures. This rutile phase transforms into …
Date: August 1, 2008
Creator: Schneller, T.; Schneller, T.; Kohlstedt, H.; Petraru, A.; Waser, R.; Guo, J. et al.
System: The UNT Digital Library
Mixing and CP Violation at the Tevatron (open access)

Mixing and CP Violation at the Tevatron

Measurements of meson mixing and CP violation parameters obtained by the CDF and D0 experiments at the Fermilab Tevatron are presented. These include results on B{sub s} and D meson mixing, and searches for CP violation in the decay B{sup +} {yields} J/{psi}K{sup +}, in mixing through semileptonic B{sub s} meson decays, and in the interference between mixing and decay in the process B{sub s} {yields} J/{psi}{phi}.
Date: August 1, 2008
Creator: Brooijmans, G.
System: The UNT Digital Library
Supporting Multiple Cognitive Processing Styles Using Tailored Support Systems (open access)

Supporting Multiple Cognitive Processing Styles Using Tailored Support Systems

According to theories of cognitive processing style or cognitive control mode, human performance is more effective when an individual’s cognitive state (e.g., intuition/scramble vs. deliberate/strategic) matches his/her ecological constraints or context (e.g., utilize intuition to strive for a "good-enough" response instead of deliberating for the "best" response under high time pressure). Ill-mapping between cognitive state and ecological constraints are believed to lead to degraded task performance. Consequently, incorporating support systems which are designed to specifically address multiple cognitive and functional states e.g., high workload, stress, boredom, and initiate appropriate mitigation strategies (e.g., reduce information load) is essential to reduce plant risk. Utilizing the concept of Cognitive Control Models, this paper will discuss the importance of tailoring support systems to match an operator's cognitive state, and will further discuss the importance of these ecological constraints in selecting and implementing mitigation strategies for safe and effective system performance. An example from the nuclear power plant industry illustrating how a support system might be tailored to support different cognitive states is included.
Date: August 1, 2007
Creator: Tran, Tuan Q.; Feigh, Karen M. & Pritchett, Amy R.
System: The UNT Digital Library
Kinetics of the water adsorption driven structural transformationof ZnS nanoparticles (open access)

Kinetics of the water adsorption driven structural transformationof ZnS nanoparticles

Nanoparticles of certain materials can respond structurally to changes in their surface environments. We have previously shown that methanol, water adsorption, and aggregation-disaggregation can change the structure of 3 nm diameter zinc sulfide (ZnS). However, in prior observations of water-driven structure change, aggregation may also have taken place. Therefore, we investigated the structural consequences of water adsorption alone on anhydrous nanoparticles that were dried to minimize changes in aggregation. Using simultaneously collected small- and wide-angle x-ray scattering (SAXS/WAXS) data, we show that water vapor adsorption alone drives a structural transformation in ZnS nanoparticles in the temperature range 22-40 C. The transition kinetics are strongly temperature dependent, with an activation energy of 58.1 {+-} 9.8 kJ/mol, consistent with atom displacement rather than bond breaking. At 50 C, aggregate restructuring occurred, increasing the transition kinetics beyond the rate expected for water adsorption alone. The observation of isosbestic points in the WAXS data suggests that the particles do not transform continuously between the initial and final structural state but rather undergo an abrupt change from a less ordered to a more ordered state.
Date: August 1, 2007
Creator: Goodell, C. M.; Gilbert, B.; Weigand, S. J. & Banfield, J. F.
System: The UNT Digital Library
Measurement of the Top Quark Mass using Quantities with Minimal Dependence on the Jet Energy Scale (open access)

Measurement of the Top Quark Mass using Quantities with Minimal Dependence on the Jet Energy Scale

None
Date: August 1, 2008
Creator: Garberson, F.; Incandela, J.; Koay, S.; Rossin, R.; /UC, Santa Barbara; Hill, C. et al.
System: The UNT Digital Library
IMG/M: A data management and analysis system for metagenomes (open access)

IMG/M: A data management and analysis system for metagenomes

IMG/M is a data management and analysis system for microbial community genomes (metagenomes) hosted at the Joint Genome Institute (JGI). IMG/M consists of metagenome data integrated with isolate microbial genomes from the Integrated Microbial Genomes (IMG) system. IMG/M provides IMG's comparative data analysis tools extended to handle metagenome data, together with metagenome-specific analysis tools. IMG/M is available at http://img.jgi.doe.gov/m. Studies of the collective genomes (also known as metagenomes) of environmental microbial communities (also known as microbiomes) are expected to lead to advances in environmental cleanup, agriculture, industrial processes, alternative energy production, and human health (1). Metagenomes of specific microbiome samples are sequenced by organizations worldwide, such as the Department of Energy's (DOE) Joint Genome Institute (JGI), the Venter Institute and the Washington University in St. Louis using different sequencing strategies, technology platforms, and annotation procedures. According to the Genomes OnLine Database, about 28 metagenome studies have been published to date, with over 60 other projects ongoing and more in the process of being launched (2). The Department of Energy's (DOE) Joint Genome Institute (JGI) is one of the major contributors of metagenome sequence data, currently sequencing more than 50% of the reported metagenome projects worldwide. Due to the higher complexity, …
Date: August 1, 2007
Creator: Markowitz, Victor M.; Ivanova, Natalia N.; Szeto, Ernest; Palaniappan, Krishna; Chu, Ken; Dalevi, Daniel et al.
System: The UNT Digital Library
The Trichoplax Genome and the Nature of Placozoans (open access)

The Trichoplax Genome and the Nature of Placozoans

Placozoans are arguably the simplest free-living animals, possibly evoking an early stage in metazoan evolution, yet their biology is poorly understood. Here we report the sequencing and analysis of the {approx}98 million base pair nuclear genome of the placozoan Trichoplax adhaerens. Whole genome phylogenetic analysis suggests that placozoans belong to a 'eumetazoan' clade that includes cnidarians and bilaterians, with sponges as the earliest diverging animals. The compact genome exhibits conserved gene content, gene structure, and synteny relative to the human and other complex eumetazoan genomes. Despite the apparent cellular and organismal simplicity of Trichoplax, its genome encodes a rich array of transcription factor and signaling pathway genes that are typically associated with diverse cell types and developmental processes in eumetazoans, motivating further searches for cryptic cellular complexity and/or as yet unobserved life history stages.
Date: August 1, 2008
Creator: Srivastava, Mansi; Begovic, Emina; Chapman, Jarrod; Putnam, Nicholas H.; Hellsten, Uffe; Kawashima, Takeshi et al.
System: The UNT Digital Library
Searching for the Optimal Mix of Solar and Efficiency in Zero Net Energy Buildings: Preprint (open access)

Searching for the Optimal Mix of Solar and Efficiency in Zero Net Energy Buildings: Preprint

Zero net energy buildings employ efficiency to reduce energy consumption and solar technologies to produce as much energy on site as is consumed on an annual basis.
Date: August 1, 2008
Creator: Horowitz, S.; Christensen, C. & Anderson, R.
System: The UNT Digital Library
Neutral Beam Injection for Plasma and Magnetic FieldDiagnostics (open access)

Neutral Beam Injection for Plasma and Magnetic FieldDiagnostics

At the Lawrence Berkeley National Laboratory (LBNL) adiagnostic neutral beam injection system for measuring plasma parameters,flow velocity, and local magnetic field is being developed. High protonfraction and small divergence is essential for diagnostic neutral beams.In our design, a neutral hydrogen beam with an 8 cm x 11 cm (or smaller)elliptical beam spot at 2.5 m from the end of the extraction column isproduced. The beam will deliver up to 5 A of hydrogen beam to the targetwith a pulse width of ~;1 s, once every 1 - 2 min. The H1+ ion species ofthe hydrogen beamwill be over 90 percent. For this application, we havecompared two types of RF driven multicusp ion sources operating at 13.56MHz. The first one is an ion source with an external spiral antennabehind a dielectric RF-window. The second one uses an internal antenna insimilar ion source geometry. The source needs to generate uniform plasmaover a large (8 cm x 5 cm) extraction area. We expect that the ion sourcewith internal antenna will be more efficient at producing the desiredplasma density but might have the issue of limited antenna lifetime,depending on the duty factor. For both approaches there is a need forextra shielding to protect the …
Date: August 1, 2007
Creator: Vainionpaa, Jaakko Hannes; Leung, Ka Ngo; Kwan, Joe W. & Levinton,Fred
System: The UNT Digital Library
Neutrino oscillation results from MINOS (open access)

Neutrino oscillation results from MINOS

The Main Injector Neutrino Oscillation Search (MINOS) long-baseline experiment has been actively collecting beam data since 2005, having already accumulated 3 x 10{sup 20} protons-on-target (POT). MINOS uses the Neutrinos at the Main Injector (NuMI) neutrino beam measured in two locations: at Fermilab, close to beam production, and 735 km downstream, in Northern Minnesota. By observing the oscillatory structure in the neutrino energy spectrum, MINOS can precisely measure the neutrino oscillation parameters in the atmospheric sector. These parameters were determined to be |{Delta}m{sub 32}{sup 2}| = 2.74{sub -0.26}{sup +0.44} x 10{sup -3} eV{sup 2}/c{sup 4} and sin{sup 2}(2{theta}{sub 23}) > 0.87 (68% C.L.) from analysis of the first year of data, corresponding to 1.27 x 10{sup 20} POT.
Date: August 1, 2007
Creator: Sousa, Alexandre
System: The UNT Digital Library
Energy in the Mountain West: Colonialism and Independence (open access)

Energy in the Mountain West: Colonialism and Independence

In many ways, the mountain west (Alaska, Arizona, Colorado, Idaho, Montana, New Mexico, Nevada, Utah, Wyoming) is an energy colony for the rest of the United States: it is rich in energy resources that are extracted to fuel economic growth in the wealthier and more populous coastal regions. Federal agencies and global corporations often behave as if the mountain west is a place to be exploited or managed for the benefit of customers and consumers elsewhere. Yet, the area. is not vast empty space with a limitless supply of natural resources, but rather a fast-growing region with a diverse economic base dependent on a limited supply of water. New decision processes and collaborations are slowly changing this situation, but in a piecemeal fashion that places local communities at odds with powerful external interests. Proper planning of major development is needed to insure that the west has a strong economic and cultural future after the fossil energy resources decline, even if that might be a century from now. To encourage the necessary public discussions, this paper identifies key differences between the mountain west and the rest of the United States and suggests some holistic approaches that could improve our future. This …
Date: August 1, 2007
Creator: Piet, Steven; Brown, Lloyd; Cherry, Robert; Cooper, Craig; Heydt, Harold; Holman, Richard et al.
System: The UNT Digital Library
Advantages and Disadvantages of Physiological Assessment For Next Generation Control Room Design (open access)

Advantages and Disadvantages of Physiological Assessment For Next Generation Control Room Design

Abstract - We propose using non-obtrusive physiological assessment (e.g., eye tracking,) to assess human information processing errors (e.g., loss of vigilance) and limitations (e.g., workload) for advanced energy systems early in the design process. This physiological approach for assessing risk will circumvent many limitations of current risk methodologies such as subjective rating (e.g., rater’s biases) and performance modeling (e.g., risk assessment is scripted and is based upon the individual modeler’s judgment). Key uses will be to evaluate (early in the design process) novel control room equipment and configurations as well as newly developed automated systems that will inevitably place a high information load on operators. The physiological risk assessment tool will allow better precision in pinpointing problematic design issues and will provide a “real-time” assessment of risk. Furthermore, this physiological approach would extend the state-of-the-art of human reliability methods from a “static” measure to more “dynamic.” This paper will discuss a broad range of the current popular online performance gauges as well as its advantages and disadvantages for use in next generation control room.
Date: August 1, 2007
Creator: Tran, Tuan Q.; Boring, Ronald L.; Dudenhoeffer, Donald D.; Hallbert, Bruce P; Keller, M. David & Anderson, Tessa M.
System: The UNT Digital Library
The Anti-B ---> D* l anti-nu form factor at zero recoil from three-flavor lattice QCD: A Model independent determination of |V(cb)| (open access)

The Anti-B ---> D* l anti-nu form factor at zero recoil from three-flavor lattice QCD: A Model independent determination of |V(cb)|

None
Date: August 1, 2008
Creator: Bernard, C.; DeTar, C.; Di Pierro, M.; El-Khadra, A. X.; Evans, R. T.; Freeland, E. D. et al.
System: The UNT Digital Library
QCD, Tevatron results and LHC prospects (open access)

QCD, Tevatron results and LHC prospects

We present a summary of the most recent measurements relevant to Quantum Chromodynamics (QCD) delivered by the D0 and CDF Tevatron experiments by May 2008. CDF and D0 are moving toward precision measurements of QCD based on data samples in excess of 1 fb-1. The inclusive jet cross sections have been extended to forward rapidity regions and measured with unprecedented precision following improvements in the jet energy calibration. Results on dijet mass distributions, bbbar dijet production using tracker based triggers, underlying event in dijet and Drell-Yan samples, inclusive photon and diphoton cross sections complete the list of measurements included in this paper. Good agreement with pQCD within errors is observed for jet production measurements. An improved and consistent theoretical description is needed for photon+jets processes. Collisions at the LHC are scheduled for early fall 2008, opening an era of discoveries at the new energy frontier, 5-7 times higher than that of the Tevatron.
Date: August 1, 2008
Creator: Elvira, V.Daniel
System: The UNT Digital Library
Wind Energy Status and Future Wind Engineering Challenges: Preprint (open access)

Wind Energy Status and Future Wind Engineering Challenges: Preprint

This paper describes the current status of wind energy technology, the potential for future wind energy development and the science and engineering challenges that must be overcome for the technology to meet its potential.
Date: August 1, 2008
Creator: Thresher, R.; Schreck, S.; Robinson, M. & Veers, P.
System: The UNT Digital Library
Empirical Analysis of the Spot Market Implications ofPrice-Responsive Demand (open access)

Empirical Analysis of the Spot Market Implications ofPrice-Responsive Demand

Regardless of the form of restructuring, deregulatedelectricity industries share one common feature: the absence of anysignificant, rapid demand-side response to the wholesale (or, spotmarket) price. For a variety of reasons, most electricity consumers stillpay an average cost based regulated retail tariff held over from the eraof vertical integration, even as the retailers themselves are oftenforced to purchase electricity at volatile wholesale prices set in openmarkets. This results in considerable price risk for retailers, who aresometimes additionally forbidden by regulators from signing hedgingcontracts. More importantly, because end-users do not perceive real-time(or even hourly or daily) fluctuations in the wholesale price ofelectricity, they have no incentive to adjust their consumptionaccordingly. Consequently, demand for electricity is highly inelastic,which together with the non storability of electricity that requiresmarket clearing over very short time steps spawn many other problemsassociated with electricity markets, such as exercise of market power andprice volatility. Indeed, electricity generation resources can bestretched to the point where system adequacy is threatened. Economictheory suggests that even modest price responsiveness can relieve thestress on generation resources and decrease spot prices. To quantify thiseffect, actual generator bid data from the New York control area is usedto construct supply stacks and intersect them with demand curves …
Date: August 1, 2005
Creator: Siddiqui, Afzal S.; Bartholomew, Emily S. & Marnay, Chris
System: The UNT Digital Library
HINS Superconducting Lens and Cryostat Performance (open access)

HINS Superconducting Lens and Cryostat Performance

Fermi National Accelerator Laboratory is involved in the development of a 60 MeV superconducting linac. This linac is part of the High Intensity Neutrino Source (HINS) R&D Program. The initial beam acceleration in the front end section of the linac is achieved using room temperature spoke cavities, each of which is combined with a superconducting focusing solenoid. These solenoid magnets are cooled with liquid helium at 4.5K, operate at 250 A and have a maximum magnetic field strength of 7.5 T. A prototype solenoid cryostat was built and tested at the Fermilab Magnet Test Facility. This paper discusses the test results of the prototype and compares the measured and estimated performance of the cryostat. We also present the methods and results for measuring and fiducializing the axis of the solenoid lens.
Date: August 1, 2008
Creator: Page, T. M.; DiMarco, J.; Huang, Y.; Orris, D. F.; Tartaglia, M. A.; Terechkine, I. et al.
System: The UNT Digital Library
Low energy spread 100 MeV-1 GeV electron bunches from laserwakefiel d acceleration at LOASIS (open access)

Low energy spread 100 MeV-1 GeV electron bunches from laserwakefiel d acceleration at LOASIS

Experiments at the LOASIS laboratory of LBNL recentlydemonstrated production of 100 MeV electron beams with low energy spreadand low divergence from laser wakefield acceleration. The radiationpressure of a 10 TW laser pulse guided over 10 diffraction ranges by aplasma density channel was used to drive an intense plasma wave(wakefield), producing acceleration gradients on the order of 100 GV/m ina mm-scale channel. Beam energy has now been increased from 100 to 1000MeV by using a cm-scale guiding channel at lower density, driven by a 40TW laser, demonstrating the anticipated scaling to higher beam energies.Particle simulations indicate that the low energy spread beams wereproduced from self trapped electrons through the interplay of trapping,loading, and dephasing. Other experiments and simulations are alsounderway to control injection of particles into the wake, and henceimprove beam quality and stability further.
Date: August 1, 2006
Creator: Geddes, C. G. R.; Esarey, E.; Michel, P.; Nagler, B.; Nakamura, K.; Plateau, G. R. et al.
System: The UNT Digital Library
Geant4 validation with CMS calorimeters test-beam data (open access)

Geant4 validation with CMS calorimeters test-beam data

CMS experiment is using Geant4 for Monte-Carlo simulation of the detector setup. Validation of physics processes describing hadronic showers is a major concern in view of getting a proper description of jets and missing energy for signal and background events. This is done by carrying out an extensive studies with test beam using the prototypes or real detector modules of the CMS calorimeter. These data are matched with Geant4 predictions. Tuning of the Geant4 models is carried out and steps to be used in reproducing detector signals are defined in view of measurements of energy response, energy resolution, transverse and longitudinal shower profiles for a variety of hadron beams over a broad energy spectrum between 2 to 300 GeV/c.
Date: August 1, 2008
Creator: Piperov, Stefan & /Sofiya, Inst. Nucl. Res. /Fermilab
System: The UNT Digital Library
Searches for squarks and gluinos at CDF and D0 detectors (open access)

Searches for squarks and gluinos at CDF and D0 detectors

This contribution reports on preliminary measurements of searches for squarks and gluinos at CDF and D0 detectors in p{bar p} collisions at {radical}s = 1.96 TeV using 1 fb{sup -1} of data. The analyses are optimized for event topologies with multiple jets and large missing transverse energy in the final state. No excess with respect to the Standard Model predictions is observed and new limits on the gluino and squark masses are extracted in a mSUGRA scenario with R-parity conservation.
Date: August 1, 2007
Creator: Portell, Xavier
System: The UNT Digital Library
Energy Design Guides for Army Barracks: Preprint (open access)

Energy Design Guides for Army Barracks: Preprint

The U.S. Army Corps of Engineers and NREL are developing target energy budgets and design guides to achieve 30% energy savings. This paper focuses the design guide for one type of barracks called unaccompanied enlisted personal housing.
Date: August 1, 2008
Creator: Deru, M.; Zhivov, A. & Herron, D.
System: The UNT Digital Library
Quantitative X-ray microanalysis of submicron carbide formation in chromium (III) oxide rich scale (open access)

Quantitative X-ray microanalysis of submicron carbide formation in chromium (III) oxide rich scale

This paper discusses the chemical microanalysis techniques adapted to identify the precipitates that form on the surface of, or within, the oxide scale of a Fe-22Cr ferritic steel during exposure to a carbon-monoxide rich environment at 750C for 800 hours. Examination of oxidized test coupons revealed the presence of a fiber like structure at the surface, shown in figure 1. Other studies have reported that these structures are carbon precipitates.
Date: August 1, 2007
Creator: Collins, W.K.; Ziomek-Moroz, M.; Holcomb, G.R.; Danielson, P. & Hunt, A.H
System: The UNT Digital Library
Clean Slate Environmental Remediation DSA for 10 CFR 830 Compliance (open access)

Clean Slate Environmental Remediation DSA for 10 CFR 830 Compliance

Clean Slate Sites II and III are scheduled for environmental remediation (ER) to remove elevated levels of radionuclides in soil. These sites are contaminated with legacy remains of non-nuclear yield nuclear weapons experiments at the Nevada Test Site, that involved high explosive, fissile, and related materials. The sites may also hold unexploded ordnance (UXO) from military training activities in the area over the intervening years. Regulation 10 CFR 830 (Ref. 1) identifies DOE-STD-1120-98 (Ref. 2) and 29 CFR 1910.120 (Ref. 3) as the safe harbor methodologies for performing these remediation operations. Of these methodologies, DOE-STD-1120-98 has been superseded by DOE-STD-1120-2005 (Ref. 4). The project adopted DOE-STD-1120-2005, which includes an approach for ER projects, in combination with 29 CFR 1910.120, as the basis documents for preparing the documented safety analysis (DSA). To securely implement the safe harbor methodologies, we applied DOE-STD-1027-92 (Ref. 5) and DOE-STD-3009-94 (Ref. 6), as needed, to develop a robust hazard classification and hazards analysis that addresses non-standard hazards such as radionuclides and UXO. The hazard analyses provided the basis for identifying Technical Safety Requirements (TSR) level controls. The DOE-STD-1186-2004 (Ref. 7) methodology showed that some controls warranted elevation to Specific Administrative Control (SAC) status. In addition to …
Date: August 1, 2006
Creator: James L. Traynor, Stephen L. Nicolosi, Michael L. Space, Louis F. Restrepo
System: The UNT Digital Library
Pursuing Energy Efficiency as a Hedge against Carbon Regulatory Risks: Current Resource Planning Practices in the West (open access)

Pursuing Energy Efficiency as a Hedge against Carbon Regulatory Risks: Current Resource Planning Practices in the West

Uncertainty surrounding the nature and timing of future carbon regulations poses a fundamental and far-reaching financial risk for electric utilities and their ratepayers. Long-term resource planning provides a potential framework within which utilities can assess carbon regulatory risk and evaluate options for mitigating exposure to this risk through investments in energy efficiency and other low-carbon resources. In this paper, we examine current resource planning practices related to managing carbon regulatory risk, based on a comparative analysis of the most-recent long-term resource plans filed by fifteen major utilities in the Western U.S. First, we compare the assumptions and methods used by utilities to assess carbon regulatory risk and to evaluate energy efficiency as a risk mitigation option. Although most utilities have made important strides in beginning to address carbon regulatory risk within their resource plan, we also identify a number of opportunities for improvement and offer recommendations for resource planners and state regulators to consider. We also summarize the composition and carbon intensity of the preferred resource portfolios selected by the fifteen Western utilities, highlighting the contribution of energy efficiency and its impact on the carbon intensity of utilities' proposed resource strategies. Energy efficiency and renewables are the dominant low-carbon resources …
Date: August 1, 2008
Creator: Barbose, Galen; Wiser, Ryan; Phadke, Amol & Goldman, Charles
System: The UNT Digital Library