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open access

An Insect Herbivore Microbiome with High Plant Biomass-Degrading Capacity

Description: Herbivores can gain indirect access to recalcitrant carbon present in plant cell walls through symbiotic associations with lignocellulolytic microbes. A paradigmatic example is the leaf-cutter ant (Tribe: Attini), which uses fresh leaves to cultivate a fungus for food in specialized gardens. Using a combination of sugar composition analyses, metagenomics, and whole-genome sequencing, we reveal that the fungus garden microbiome of leaf-cutter ants is composed of a diverse community of bacteria w… more
Date: September 23, 2010
Creator: Suen, Garret; Barry, Kerrie; Goodwin, Lynne; Scott, Jarrod; Aylward, Frank; Adams, Sandra et al.
Partner: UNT Libraries Government Documents Department
open access

Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX)

Description: We report results on lithium alumino-silicate ion source development in preparation for warmdense-matter heating experiments on the new Neutralized Drift Compression Experiment (NDCXII). The practical limit to the current density for a lithium alumino-silicate source is determined by the maximum operating temperature that the ion source can withstand before running into problems of heat transfer, melting of the alumino-silicate material, and emission lifetime. Using small prototype emitters, at… more
Date: October 1, 2010
Creator: Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W.; Seidl, Peter A.; Waldron, William L. & Wu, James K.
Partner: UNT Libraries Government Documents Department
open access

A truncated Levenberg-Marquardt algorithm for the calibration of highly parameterized nonlinear models

Description: We propose a modification to the Levenberg-Marquardt minimization algorithm for a more robust and more efficient calibration of highly parameterized, strongly nonlinear models of multiphase flow through porous media. The new method combines the advantages of truncated singular value decomposition with those of the classical Levenberg-Marquardt algorithm, thus enabling a more robust solution of underdetermined inverse problems with complex relations between the parameters to be estimated and the… more
Date: October 15, 2010
Creator: Finsterle, S. & Kowalsky, M.B.
Partner: UNT Libraries Government Documents Department
open access

What Can China Do? China's Best Alternative Outcome for Energy Efficiency and CO2 Emissions

Description: After rapid growth in economic development and energy demand over the last three decades, China has undertaken energy efficiency improvement efforts to reduce its energy intensity under the 11th Five Year Plan (FYP). Since becoming the world's largest annual CO{sub 2} emitter in 2007, China has set reduction targets for energy and carbon intensities and committed to meeting 15% of its total 2020 energy demand with non-fossil fuel. Despite having achieved important savings in 11th FYP efficiency… more
Date: July 1, 2010
Creator: G. Fridley, David; Zheng, Nina & T. Aden, Nathaniel
Partner: UNT Libraries Government Documents Department
open access

Biospecimen Reporting for Improved Study Quality (BRISQ)

Description: Human biospecimens are subjected to collection, processing, and storage that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research that uses … more
Date: September 2, 2010
Creator: Institute, National Cancer; Jewell, Ph.D., Scott D.; Seijo, M.S., Edward; Kelly, Ph.D., Andrea; Somiari, Ph.D., Stella; B.Chir., M.B. et al.
Partner: UNT Libraries Government Documents Department
open access

A New Approach in Advance Network Reservation and Provisioning for High-Performance Scientific Data Transfers

Description: Scientific applications already generate many terabytes and even petabytes of data from supercomputer runs and large-scale experiments. The need for transferring data chunks of ever-increasing sizes through the network shows no sign of abating. Hence, we need high-bandwidth high speed networks such as ESnet (Energy Sciences Network). Network reservation systems, i.e. ESnet's OSCARS (On-demand Secure Circuits and Advance Reservation System) establish guaranteed bandwidth of secure virtual circui… more
Date: January 28, 2010
Creator: Balman, Mehmet; Chaniotakis, Evangelos; Shoshani, Arie & Sim, Alex
Partner: UNT Libraries Government Documents Department
open access

Correlation between structure and electrical transport in ion-irradiated graphene grown on Cu foils

Description: Graphene grown by chemical vapor deposition and supported on SiO2 and sapphire substrates was studied following controlled introduction of defects induced by 35 keV carbon ion irradiation. Changes in Raman spectra following fluences ranging from 1012 cm-2 to 1015 cm-2 indicate that the structure of graphene evolves from a highly-ordered layer, to a patchwork of disordered domains, to an essentially amorphous film. These structural changes result in a dramatic decrease in the Hall mobility by or… more
Date: November 4, 2010
Creator: Buchowicz, G.; Stone, P. R.; Robinson, J. T.; Cress, C. D.; Beeman, J. W. & Dubon, O. D.
Partner: UNT Libraries Government Documents Department
open access

Modified magnetic ground state in NiMn2O4 thin films

Description: We demonstrate the stabilization of a magnetic ground state in epitaxial NiMn2O4 (NMO) thin films not observed in their bulk counterpart. Bulk NMO exhibits a magnetic transition from a paramagnetic phase to a collinear ferrimagnetic moment configuration below 110 K and to a canted moment configuration below 70 K. By contrast, as-grown NMO films exhibit a single magnetic transition at 60 K and annealed films exhibit the magnetic behavior found in bulk. Cation inversion and epitaxial strain are r… more
Date: August 3, 2010
Creator: Nelson-Cheeseman, B. B.; Chopdekar, R. V.; Toney, M. F.; Arenholz, E.; Suzuki, Y. & Iwata, J.M.
Partner: UNT Libraries Government Documents Department
open access

The BErkeley Lab Laser Accelerator (BELLA): A 10 GeV Laser Plasma Accelerator

Description: An overview is presented of the design of a 10 GeV laser plasma accelerator (LPA) that will be driven by a PW-class laser system and of the BELLA Project, which has as its primary goal to build and install the required Ti:sapphire laser system for the acceleration experiments. The basic design of the 10 GeV stage aims at operation in the quasi-linear regime, where the laser excited wakes are largely sinusoidal and offer the possibility of accelerating both electrons and positrons. Simulations s… more
Date: June 1, 2010
Creator: Leemans, W. P.; Duarte, R.; Esarey, E.; Fournier, S.; Geddes, C. G. R.; Lockhart, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Importance of electronic relaxation for inter-coulombic decay in aqueous systems

Description: Inspired by recent photoelectron spectroscopy (PES) experiments on hydroxide solutions, we have examined the conditions necessary for enhanced (and, in the case of solutions, detectable) intercoulombic decay (ICD)--Auger emission from an atomic site other than that originally excited. We present general guidelines, based on energetic and spatial overlap of molecular orbitals, for this enhancement of ICDbased energy transfer in solutions. These guidelines indicate that this decay process should … more
Date: October 1, 2010
Creator: Schwartz, Craig P.; Fatehi, Shervin; Saykally, Richard J. & Prendergast, David
Partner: UNT Libraries Government Documents Department
open access

Electronic structure and spectroscopy of nucleic acid bases: Ionization energies, ionization-induced structural changes, and photoelectron spectra

Description: We report high-level ab initio calculations and single-photon ionization mass spectrometry study of ionization of adenine (A), thymine (T), cytosine (C) and guanine (G). For thymine and adenine, only the lowest-energy tautomers were considered, whereas for cytosine and guanine we characterized five lowest-energy tautomeric forms. The first adiabatic and several vertical ionization energies were computed using equation-of-motion coupled-cluster method for ionization potentials with single and do… more
Date: August 2, 2010
Creator: Bravaya, Ksenia B.; Kostko, Oleg; Dolgikh, Stanislav; Landau, Arie; Ahmed, Musahid & Krylov, Anna I.
Partner: UNT Libraries Government Documents Department
open access

Review of the Recent Frequency Performance of the Eastern, Western and ERCOT Interconnections

Description: The reliable operation of an electric power system depends on careful management of the balance between generation and load to ensure that system frequency is maintained within narrow bounds around a scheduled value. Yet, maintaining frequency at the scheduled value is challenging because the load served is continuously changing, and occasionally, events such as the sudden loss of a large generation plant or large amount of load, cause frequency to deviate abruptly. This report reviews the rece… more
Date: December 20, 2010
Creator: Lacommare, Kristina S H
Partner: UNT Libraries Government Documents Department
open access

High Rate Deposition of High Quality ZnO:Al by Filtered Cathodic Arc

Description: High quality ZnO:Al (AZO) thin films were prepared on glass substrates by direct current filtered cathodic arc deposition. Substrate temperature was varied from room temperature to 425oC, and samples were grown with and without the assistance of low power oxygen plasma (75W). For each growth condition, at least 3 samples were grown to give a statistical look at the effect of the growth environment on the film properties and to explore the reproducibility of the technique. Growth rate was in the… more
Date: November 18, 2010
Creator: Mendelsberg, Rueben J.; Lim, S.H.N.; Milliron, D.J. & Anders, Andre
Partner: UNT Libraries Government Documents Department
open access

Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

Description: We present an overview of diagnostic techniques for measuring key parameters of electron bunches from Laser Plasma Accelerators (LPAs). The diagnostics presented here were chosen because they highlight the unique advantages (e.g., diverse forms of electromagnetic emission) and difficulties (e.g., shot-to-shot variability) associated with LPAs. Non destructiveness and high resolution (in space and time and energy) are key attributes that enable the formation of a comprehensive suite of simultane… more
Date: June 1, 2010
Creator: Matlis, N. H.; Bakeman, M.; Geddes, C. G. R.; Gonsalves, T.; Lin, C.; Nakamura, K. et al.
Partner: UNT Libraries Government Documents Department
open access

Summary Report of Working Group 1: Laser-Plasma Acceleration

Description: Advances in and physics of the acceleration of particles using underdense plasma structures driven by lasers were the topics of presentations and discussions in Working Group 1 of the 2010 Advanced Accelerator Concepts Workshop. Such accelerators have demonstrated gradients several orders beyond conventional machines, with quasi-monoenergetic beams at MeV-GeV energies, making them attractive candidates for next generation accelerators. Workshop discussions included advances in control over inje… more
Date: June 1, 2010
Creator: Geddes, C.G.R.; Clayton, C.; Lu, W. & Thomas, A.G.R.
Partner: UNT Libraries Government Documents Department
open access

Experimental Evaluation of Installed Cooking Exhaust Fan Performance

Description: The installed performance of cooking exhaust fans was evaluated through residential field experiments conducted on a sample of 15 devices varying in design and other characteristics. The sample included two rear downdraft systems, two under-cabinet microwave over range (MOR) units, three different installations of an under-cabinet model with grease screens across the bottom and no capture hood, two devices with grease screens covering the bottom of a large capture hood (one under-cabinet, one w… more
Date: November 1, 2010
Creator: Singer, Brett C.; Delp, William W. & Apte, Michael G.
Partner: UNT Libraries Government Documents Department
open access

A Ferrocene-Based Catecholamide Ligand: the Consequences of Ligand Swivel for Directed Supramolecular Self-Assembly

Description: A ferrocene-based biscatecholamide ligand was prepared and investigated for the formation of metal-ligand supramolecular assemblies with different metals. Reaction with Ge(IV) resulted in the formation of a variety of Ge{sub n}L{sub m} coordination complexes, including [Ge{sub 2}L{sub 3}]{sup 4-} and [Ge{sub 2}L{sub 2}({mu}-OMe){sub 2}]{sup 2-}. The ligand's ability to swivel about the ferrocenyl linker and adopt different conformations accounts for formation of many different Ge{sub n}L{sub m}… more
Date: February 4, 2010
Creator: Mugridge, Jeffrey; Fiedler, Dorothea & Raymond, Kenneth
Partner: UNT Libraries Government Documents Department
open access

Bridging silyl groups in sigma-bond metathesis and [1, 2] shifts. An experimental and computational study of the reaction between cerium metallocenes and MeOSiMe3

Description: The reaction of Cp'2CeH (Cp' = 1,2,4-(Me3C)3C5H2 ) with MeOSiMe3 gives Cp'2CeOMe and HSiMe3 and the reaction of the metallacycle, Cp'[(Me3C)2C5H2C(Me) 2CH2]Ce, with MeOSiMe3 yields Cp'2CeOCH2SiMe3, formed from hypothetical Cp'2CeCH2OSiMe3 by a [1, 2] shift also known as a silyl-Wittig rearrangement. Although both cerium products are alkoxides, they are formed by different pathways. DFT calculations on the reaction of the model metallocene, Cp2CeH, and MeOSiMe3 show that the lowest energy pathwa… more
Date: April 21, 2010
Creator: Werkema, Evan; Yahia, Ahmed; Maron, Laurent; Eisenstein, Odile & Andersen, Richard
Partner: UNT Libraries Government Documents Department
open access

Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation

Description: An interconnected electric power system is a complex system that must be operated within a safe frequency range in order to reliably maintain the instantaneous balance between generation and load. This is accomplished by ensuring that adequate resources are available to respond to expected and unexpected imbalances and restoring frequency to its scheduled value in order to ensure uninterrupted electric service to customers. Electrical systems must be flexible enough to reliably operate under a … more
Date: December 20, 2010
Creator: Eto, Joseph H.; Undrill, John; Mackin, Peter; Daschmans, Ron; Williams, Ben; Haney, Brian et al.
Partner: UNT Libraries Government Documents Department
open access

The Role of Quench-back in the Passive Quench Protection of Uncoupled Solenoids in Series with and without Coil Sub-division

Description: This paper is the final paper in a series of papers that discusses passive quench protection for high inductance solenoid magnets. This report describes how passive quench protection system may be applied to superconducting magnets that are connected in series but not inductively coupled. Previous papers have discussed the role of magnet sub-division and quench back from a conductive mandrel in reducing the hot-spot temperature and the peak coil voltages to ground. When magnets are connected in… more
Date: October 15, 2010
Creator: Guo, Xing Long; Green, Michael A; Wang, Li; Wu, Hong & Pan, Heng
Partner: UNT Libraries Government Documents Department
open access

Determination of the spin-flip time in ferromagnetic SrRuO3 from time-resolved Kerr measurements

Description: We report time-resolved Kerr effect measurements of magnetization dynamics in ferromagnetic SrRuO{sub 3}. We observe that the demagnetization time slows substantially at temperatures within 15K of the Curie temperature, which is {approx} 150K. We analyze the data with a phenomenological model that relates the demagnetization time to the spin flip time. In agreement with our observations the model yields a demagnetization time that is inversely proportional to T-T{sub c}. We also make a direct c… more
Date: July 30, 2010
Creator: Kantner, C. L. S.; Langner, M. C.; Siemons, W.; Blok, J. L.; Koster, G.; Rijnders, A.J. H. M. et al.
Partner: UNT Libraries Government Documents Department
open access

Metabolic Design and Control for Production in Prokaryotes

Description: Prokaryotic life on earth is manifested by its diversity and omnipresence. These microbes serve as natural sources of a large variety of compounds with the potential to serve the ever growing, medicinal, chemical and transportation needs of the human population. However, commercially viable production of these compounds can be realized only through significant improvement of the native production capacity of natural isolates. The most favorable way to achieve this goal is through the genetic ma… more
Date: November 10, 2010
Creator: Chhabra, Swapnil R. & Keasling, J.D.
Partner: UNT Libraries Government Documents Department
open access

Subduction Controls of Hf and Nd Isotopes in Lavas of the Aleutian Island Arc

Description: The Hf and Nd isotopic compositions of 71 Quaternary lavas collected from locations along the full length of the Aleutian island arc are used to constrain the sources of Aleutian magmas and to provide insight into the geochemical behavior of Nd and Hf and related elements in the Aleutian subduction-magmatic system. Isotopic compositions of Aleutian lavas fall approximately at the center of, and form a trend parallel to, the terrestrial Hf-Nd isotopic array with {var_epsilon}{sub Hf} of +12.0 to… more
Date: August 29, 2010
Creator: Yogodzinski, Gene; Vervoort, Jeffery; Brown, Shaun Tyler & Gerseny, Megan
Partner: UNT Libraries Government Documents Department
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