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

Description: An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.
Date: May 3, 2010
Creator: Arceo, Elena; Ellman, Jonathan & Bergman, Robert
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The hierarchy of multiple many-body interaction scales in high-temperature superconductors

Description: To date, angle-resolved photoemission spectroscopy has been successful in identifying energy scales of the many-body interactions in correlated materials, focused on binding energies of up to a few hundred meV below the Fermi energy. Here, at higher energy scale, we present improved experimental data from four families of high-T{sub c} superconductors over a wide doping range that reveal a hierarchy of many-body interaction scales focused on: the low energy anomaly ('kink') of 0.03-0.09eV, a hi… more
Date: May 3, 2010
Creator: Meevasana, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Glass Composition Constraint Recommendations for Use in Life-Cycle Mission Modeling

Description: The component concentration limits that most influence the predicted Hanford life-cycle HLW glass volume by HTWOS were re-evaluated. It was assumed that additional research and development work in glass formulation and melter testing would be performed to improve the understanding of component effects on the processability and product quality of these HLW glasses. Recommendations were made to better estimate the potential component concentration limits that could be applied today while technolo… more
Date: May 3, 2010
Creator: McCloy, John S. & Vienna, John D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Angle-resolved photoemission studies of lattice polaron formation in the cuprate Ca2CuO2Cl2

Description: To elucidate the nature of the single-particle excitations in the undoped parent cuprates, we have performed a detailed study of Ca{sub 2}CuO{sub 2}Cl{sub 2} using photoemission spectroscopy. The photoemission lineshapes of the lower Hubbard band are found to be well-described by a polaron model. By comparing the lineshape and temperature dependence of the lower Hubbard band with additional O 2p and Ca 3p states, we conclude that the dominant broadening mechanism arises from the interaction bet… more
Date: May 3, 2010
Creator: Shen, K.M.
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Partner: UNT Libraries Government Documents Department
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Anomalous Fermi-Surface Dependent Pairing in a Self-Doped High-Tc Superconductor

Description: We report the discovery of a self-doped multi-layer high T{sub c} superconductor Ba{sub 2}Ca{sub 3}Cu{sub 4}O{sub 8}F{sub 2} (F0234) which contains distinctly different superconducting gap magnitudes along its two Fermi surface(FS) sheets. While formal valence counting would imply this material to be an undoped insulator, it is a self-doped superconductor with a T{sub c} of 60K, possessing simultaneously both electron- and hole-doped FS sheets. Intriguingly, the FS sheet characterized by the mu… more
Date: May 3, 2010
Creator: Chen, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Doping Dependent Charge Transfer Gap and Realistic Electronic Model of n-type Cuprate Superconductors

Description: Based on the analysis of the measurement data of angle-resolved photoemission spectroscopy (ARPES) and optics, we show that the charge transfer gap is significantly smaller than the optical one and is reduced by doping in electron doped cuprate superconductors. This leads to a strong charge fluctuation between the Zhang-Rice singlet and the upper Hubbard bands. The basic model for describing this system is a hybridized two-band t-J model. In the symmetric limit where the corresponding intra- an… more
Date: May 3, 2010
Creator: Xiang, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Doping Evolution of the Underlying Fermi Surface in La_2&#8722xSr_xCuO_4

Description: We have performed a systematic doping dependent study of La{sub 2-x}Sr{sub x}CuO{sub 4} (LSCO) (0.03 {le} x {le} 0.3) by angle-resolved photoemission spectroscopy. In the entire doping range, the underlying 'Fermi surface' determined from the low energy spectral weight approximately satisfies Luttinger's theorem, even down to the lightly-doped region. This is in strong contrast to the result on Ca{sub 2-x}Na{sub x}CuO{sub 2}Cl{sub 2} (Na-CCOC), which shows a strong deviation from Luttinger's th… more
Date: May 3, 2010
Creator: Yoshida, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Enhanced superconducting pairing interaction in indium-doped tin telluride

Description: The ferroelectric degenerate semiconductor Sn{sub 1-{delta}}Te exhibits superconductivity with critical temperatures, T{sub c}, of up to 0.3 K for hole densities of order 10{sup 21} cm{sup -3}. When doped on the tin site with greater than x{sub c} = 1.7(3)% indium atoms, however, superconductivity is observed up to 2 K, though the carrier density does not change significantly. We present specific heat data showing that a stronger pairing interaction is present for x > x{sub c} than for x &lt… more
Date: May 3, 2010
Creator: Erickson, A.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of the Spectral Function of Nd1.85Ce0.15CuO4, Obtained by Angle Resolved Photoemission Spectroscopy

Description: Samples of Nd{sub 2-x}Ce{sub x}CuO{sub 4}, an electron-doped high temperature superconducting cuprate (HTSC), near optimal doping at x = 0.155 were measured via angle resolved photoemission (ARPES). We report a renormalization feature in the self energy ('kink') in the band dispersion at {approx} 50-60 meV present in nodal and antinodal cuts across the Fermi surface. Specifically, while the kink had been seen in the antinodal region, it is now observed also in the nodal region, reminiscent of w… more
Date: May 3, 2010
Creator: Schmitt, F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Direct observation of the mass renormalization in SrVO3 by angle resolved photoemission spectroscopy

Description: We have performed an angle-resolved photoemission study of the three-dimensional perovskite-type SrVO{sub 3}. Observed spectral weight distribution of the coherent part in the momentum space shows cylindrical Fermi surfaces consisting of the V 3d t{sub 2g} orbitals as predicted by local-density approximation (LDA) band-structure calculation. The observed energy dispersion shows a moderately enhanced effective mass compared to the LDA results, corresponding to the effective mass enhancement seen… more
Date: May 3, 2010
Creator: Yoshida, t.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Superconductivity-Induced Self-Energy Evolution of the Nodal Electron in Optimally-Doped Bi2212

Description: The temperature dependent evolution of the renormalization effect in optimally-doped Bi2212 along the nodal direction has been studied via angle-resolved photoemission spectroscopy. Fine structure is observed in the real part of the self-energy (Re{Sigma}), including a subkink and maximum, suggesting that electrons couple to a spectrum of bosonic modes, instead of just one mode. Upon cooling through the superconducting phase transition, the fine structures of the extracted Re{Sigma} exhibit a t… more
Date: May 3, 2010
Creator: Lee, W.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Pressure-induced quenching of the charge-density-wave state observed by x-ray diffraction

Description: We report an x-ray diffraction study on the charge-density-wave (CDW) LaTe{sub 3} and CeTe{sub 3} compounds as a function of pressure. We extract the lattice constants and the CDW modulation wave-vector, and provide direct evidence for a pressure-induced quenching of the CDW phase. We observe subtle differences between the chemical and mechanical compression of the lattice. We account for these with a scenario where the effective dimensionality in these CDW systems is dependent on the type of l… more
Date: May 3, 2010
Creator: Sacchetti, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Renewable Resources for Hydrogen

Description: This presentation provides an overview of renewable resources for hydrogen. It was presented at the National Hydrogen Association Hydrogen Conference & Expo in Long Beach, CA, May 3-6, 2010.
Date: May 3, 2010
Creator: Jalalzadeh-Azar, A. A.
Item Type: Refine your search to only Presentation
Partner: UNT Libraries Government Documents Department
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Simulation of E-Cloud Driven Instability and Its Attenuation Using a Feedback System in the Cern Sps

Description: Electron clouds have been shown to trigger fast growing instabilities on proton beams circulating in the SPS [1], and a feedback system to control the instabilities is under active development [2]. We present the latest improvements to the Warp-Posinst simulation framework and feedback model, and its application to the self-consistent simulations of two consecutive bunches interacting with an electron cloud in the SPS.
Date: May 3, 2010
Creator: Vay, J. L.; Byrd, J. M.; Furman, M. A.; Secondo, R.; Venturini, M.; Fox, J. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Sps Ecloud Instabilities - Analysis of Machine Studies and Implications for Ecloud Feedback

Description: The SPS at high intensities exhibits transverse single-bunch instabilities with signatures consistent with an Ecloud driven instability. They present recent MD data from the SPS, details of the instrument technique and spectral analysis methods which help reveal complex vertical motion that develops within a subset of the injected bunch trains. The beam motion is detected via wideband exponential taper striplines and delta-sigma hybrids. The raw sum and difference data is sampled at 50 GHz with… more
Date: May 3, 2010
Creator: Fox, J. D.; Bullitt, A.; Mastorides, T.; Ndabashimiye, G.; Rivetta, C.; Turgut, O. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Potential Impact of Adopting Maximum Technologies as Minimum Efficiency Performance Standards in the U.S. Residential Sector

Description: The US Department of Energy (US DOE) has placed lighting and appliance standards at a very high priority of the U.S. energy policy. However, the maximum energy savings and CO2 emissions reduction achievable via minimum efficiency performance standards (MEPS) has not yet been fully characterized. The Bottom Up Energy Analysis System (BUENAS), first developed in 2007, is a global, generic, and modular tool designed to provide policy makers with estimates of potential impacts resulting from MEPS f… more
Date: May 3, 2010
Creator: Letschert, Virginie; Desroches, Louis-Benoit; McNeil, Michael & Saheb, Yamina
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Muon g-2 Calorimeter Prototypes

Description: The proposed design is a tungsten-scintillating fiber calorimeter with 35 segments, each read out by a separate PMT. Tungsten, which is significantly denser than lead, produces compact showers. This is necessary, in order to improve shower separation in analysis and to fully contain the showers within a calorimeter that satisfies the strict space constraints of the experiment. A single calorimeter segment (4 x 6 x 15 cm{sup 3}) has been constructed in order establish the feasibility of the new … more
Date: May 3, 2010
Creator: Polly, Chris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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U.S.-Vietnam Economic and Trade Relations: Issues for the 111th Congress

Description: This report will examine each of these trade issues, discussing their main elements and exploring their implications for the 111th Congress. This will be followed by an analysis of key trends in bilateral trade to discern any potential sources of trade friction in the future.
Date: May 3, 2010
Creator: Martin, Michael F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress

Description: This report provides background information and presents potential issues for Congress concerning the Navy's ship force-structure goals and shipbuilding plans. The planned size of the Navy, the rate of Navy ship procurement, and the prospective affordability of the Navy's shipbuilding plans have been matters of concern for the congressional defense committees for the past several years. Decisions that Congress makes on Navy shipbuilding programs can substantially affect Navy capabilities and fu… more
Date: May 3, 2010
Creator: O'Rourke, Ronald
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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State Efforts to Deter Unauthorized Aliens: Legal Analysis of Arizona's S.B. 1070

Description: This report discusses the major provisions of S.B.1070, as modified by H.B. 2162, and the legal and constitutional considerations possibly implicated by their implementation. The report focuses primarily on those provisions that require state enforcement of federal immigration law and impose criminal penalties for immigration-related conduct, and discusses preemption issues that might be raised by these measures.
Date: May 3, 2010
Creator: Garcia, Michael J.; Eig, Larry M. & Kim, Yule
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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