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X-ray spectroscopic study of the charge state and local orderingof room-temperature ferromagnetic Mn oped ZnO

Description: The charge state and local ordering of Mn doped into a pulsed laser deposited single-phase thin film of ZnO are investigated by using X-ray absorption spectroscopy at the O K-, Mn K- and L-edges, and X-ray emission spectroscopy at the O K- and Mn L-edge. This film is found to be ferromagnetic at room temperature. EXAFS measurement shows that Mn{sup 2+} replaces Zn site in tetrahedral symmetry, and there is no evidence for either metallic Mn or MnO in the film. Upon Mn doping, the top of O 2p va… more
Date: August 7, 2007
Creator: Guo, J.-H.; Gupta, Amita; Sharma, Parmanand; Rao, K.V.; Marcus,M.A.; Dong, C.L. et al.
Partner: UNT Libraries Government Documents Department
open access

Ultrafast gigantic photo-response in (EDO-TTF)2PF6 initiated by 10-fs laser pulses

Description: We photo-exited a charge-ordered organic salt (EDO-TTF)2PF6 with sub-10-fs optical pulses. The photo-induced metallic phase appeared within 80-fs after pumping, characterized by large changes in reflectivity (DELTA R/R~0.8) followed by strong coherent phonon modulation
Date: August 7, 2006
Creator: Schoenlein, Robert William; Itatani, Jiro; Rini, Matteo; Cavalleri, Andrea; Onda, Ken; Ishikawa, Tadahiko et al.
Partner: UNT Libraries Government Documents Department
open access

Sensitivity study of CO2 storage capacity in brine aquifers withclosed boundaries: Dependence on hydrogeologic properties

Description: In large-scale geologic storage projects, the injected volumes of CO{sub 2} will displace huge volumes of native brine. If the designated storage formation is a closed system, e.g., a geologic unit that is compartmentalized by (almost) impermeable sealing units and/or sealing faults, the native brine cannot (easily) escape from the target reservoir. Thus the amount of supercritical CO{sub 2} that can be stored in such a system depends ultimately on how much pore space can be made available for … more
Date: February 7, 2007
Creator: Zhou, Q.; Birkholzer, J.; Rutqvist, J. & Tsang, C-F.
Partner: UNT Libraries Government Documents Department
open access

Development of backlighting sources for a Compton radiography diagnostic of Inertial Confinement Fusion targets

Description: We present scaled demonstrations of backlighter sources, emitting Bremsstrahlung x-rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the Bremsstrahlung spectrum as a function of laser intensity and pulse length, … more
Date: May 7, 2008
Creator: Tommasini, R.; MacPhee, A.; Hey, D.; Ma, T.; Chen, C.; Izumi, N. et al.
Partner: UNT Libraries Government Documents Department
open access

Geometrical Properties of a "Snow-Flake" Divertor

Description: Using a simple set of poloidal field coils, one can reach the situation where the null of the poloidal magnetic field in the divertor region is of a second order, not of the first order as in the usual X-point divertor. Then, the separatrix in the vicinity of the null-point splits the poloidal plane not into four sectors, but into six sectors, making the whole structure looking like a snow-flake (whence a name, [1]). This arrangement allows one to spread the heat load over much broader area tha… more
Date: February 7, 2007
Creator: Ryutov, D. D.
Partner: UNT Libraries Government Documents Department
open access

Mixing and CP violation in the D0 and B0(s) systems

Description: Recent developments for mixing and CP violation in the D0 and Bs systems are reviewed, including (i) the recently emerging evidence for D0-D0bar mixing and the interpretations of the measurements; (ii) the theoretical status of the calculations of Delta(Gamma_D) and Delta(m_D); (iii) some implications of the measurement of Bs mixing for new physics.
Date: May 7, 2007
Creator: Ligeti, Zoltan & Ligeti, Zoltan
Partner: UNT Libraries Government Documents Department
open access

Enhanced geothermal systems (EGS) using CO2 as working fluid - Anovelapproach for generating renewable energy with simultaneoussequestration of carbon

Description: Responding to the need to reduce atmospheric emissions of carbon dioxide, Donald Brown (2000) proposed a novel enhanced geothermal systems (EGS) concept that would use CO{sub 2} instead of water as heat transmission fluid, and would achieve geologic sequestration of CO{sub 2} as an ancillary benefit. Following up on his suggestion, we have evaluated thermophysical properties and performed numerical simulations to explore the fluid dynamics and heat transfer issues in an engineered geothermal re… more
Date: June 7, 2006
Creator: Pruess, Karsten
Partner: UNT Libraries Government Documents Department
open access

Holographic Grand Unification

Description: No Description Available.
Date: May 7, 2006
Creator: Nomura, Yasunori; Poland, David & Tweedie, Brock
Partner: UNT Libraries Government Documents Department
open access

COMPARISONS OF CRYSTALLINE SILICOTITANATE AND RESORCINOL FORMALDEHYDE MEDIA FOR CESIUM REMOVAL BY IN-TANK COLUMN PROCESSING

Description: Chemical and thermal performance of crystalline silicotitanate (CST) and resorcinol-formaldehyde (RF) ion exchange media were predicted for column configurations designed for installation in high level waste tanks and intended for cesium removal from radioactive waste supernates. Modeling predictions for the processing of a known Savannah River Site tank waste composition were generated. In a two column configuration under presumed nominal operating conditions (432 gallon packed bed, 10 gpm liq… more
Date: November 7, 2007
Creator: King, W; Frank02 Smith, F; Si Lee, S & Daniel McCabe, D
Partner: UNT Libraries Government Documents Department
open access

Numerical modeling of self-limiting and self-enhancing caprock alteration induced by CO2 storage in a depleted gas reservoir

Description: This paper presents numerical simulations of reactive transport which may be induced in the caprock of an on-shore depleted gas reservoir by the geological sequestration of carbon dioxide. The objective is to verify that CO{sub 2} geological disposal activities currently being planned for the study area are safe and do not induce any undesired environmental impact. In our model, fluid flow and mineral alteration are induced in the caprock by penetration of high CO{sub 2} concentrations from the… more
Date: September 7, 2007
Creator: Xu, Tianfu; Gherardi, Fabrizio; Xu, Tianfu & Pruess, Karsten
Partner: UNT Libraries Government Documents Department
open access

Targeting the tumor microenvironment

Description: Despite some notable successes cancer remains, for the most part, a seemingly intractable problem. There is, however, a growing appreciation that targeting the tumor epithelium in isolation is not sufficient as there is an intricate mutually sustaining synergy between the tumor epithelial cells and their surrounding stroma. As the details of this dialogue emerge, new therapeutic targets have been proposed. The FDA has already approved drugs targeting microenvironmental components such as VEGF a… more
Date: November 7, 2006
Creator: Kenny, P. A.; Lee, G. Y. & Bissell, M. J.
Partner: UNT Libraries Government Documents Department
open access

Single shot extreme ultraviolet laser imaging of nanostructures with wavelength resolution

Description: We have demonstrated near-wavelength resolution microscopy in the extreme ultraviolet. Images of 50 nm diameter nanotubes were obtained with a single {approx}1 ns duration pulse from a desk-top size 46.9 nm laser. We measured the modulation transfer function of the microscope for three different numerical aperture zone plate objectives, demonstrating that 54 nm half-period structures can be resolved. The combination of near-wavelength spatial resolution and high temporal resolution opens myriad… more
Date: January 7, 2008
Creator: Jones, Juanita; Brewer, Courtney A.; Brizuela, Fernando; Wachulak, Przemyslaw; Martz, Dale H.; Chao, Weilun et al.
Partner: UNT Libraries Government Documents Department
open access

Disruption of Maternal DNA Repair Increases Sperm-DerivedChromosomal Aberrations

Description: The final weeks of male germ cell differentiation occur in aDNA repair-deficient environment and normal development depends on theability of the egg to repair DNA damage in the fertilizing sperm. Geneticdisruption of maternal DNA double-strand break repair pathways in micesignificantly increased the frequency of zygotes with chromosomalstructural aberrations after paternal exposure to ionizing radiation.These findings demonstrate that radiation-induced DNA sperm lesions arerepaired after fertil… more
Date: February 7, 2007
Creator: Marchetti, Francesco; Essers, Jeroun; Kanaar, Roland & Wyrobek,Andrew J.
Partner: UNT Libraries Government Documents Department
open access

Lightest Isotope of Bh Produced Via the 209Bi(52Cr,n)260BhReaction

Description: The lightest isotope of Bh known was produced in the new {sup 209}Bi({sup 52}Cr,n){sup 260}Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. {sup 260}Bh decays with a 35{sub -9}{sup +19} ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59{sub -20}{sup +29}… more
Date: May 7, 2007
Creator: Nelson, Sarah L.; Gregorich, Kenneth E.; Dragojevic, Irena; Garcia, Mitch A.; Gates, Jacklyn M.; Sudowe, Ralf et al.
Partner: UNT Libraries Government Documents Department
open access

Reactions of Monomeric [1,2,4-(Me3C)3C5H2]2CeH and CO with orwithout H2:An Experimental and Computational Study

Description: Addition of CO to [1,2,4-(Me3C)3C5H2]2CeH, Cp'2CeH, intoluene yields the cis (Cp'2Ce)2(mu-OCHCHO), in which the cis enediolategroup bridges the two metallocene fragments. The cis enediolatequantitatively isomerizes intramolecularly to the trans-enediolate inC6D6 at 100oC over seven months. When the solvent is pentane,Cp'2Ce(OCH2)CeCp'2 forms, in which the oxomethylene group or theformaldehyde dianion bridges the two metallocene fragments. The cisenediolate is suggested to form by insertion of C… more
Date: September 7, 2006
Creator: Werkema, Evan L.; Maron, Laurent; Eisenstein, Odile & Andersen, Richard A.
Partner: UNT Libraries Government Documents Department
open access

Insulator-to-metal transition induced by mid-IR vibrational excitation in a magnetoresistive manganite

Description: Selective vibrational excitation of insulating Pr0.7Ca0.3MnO3 at 17 ?m triggers a transition to a metallic state. A four order of magnitude drop of the sample resistivity and ultrafast, nanosecond-lived reflectivity changes are observed
Date: August 7, 2006
Creator: Schoenlein, Robert William; Rini, Matteo; Itatani, Jiro; Tomioka, Yasuhide; Tokura, Yoshinori; Schoenlein, Robert W. et al.
Partner: UNT Libraries Government Documents Department
open access

Sensor Development for the Large Synoptic Survey Telescope.

Description: The Large Synoptic Survey project proposes to build an 8m-class ground-based telescope with a dedicated wide field camera. The camera consists of a large focal plane mosaic composed of multi-output CCDs with extended red response. Design considerations and preliminary characterization results for the sensors are presented in this contribution to the Workshop.
Date: June 7, 2007
Creator: O'Connor, P.; Radeka, V. & Takacs, P.
Partner: UNT Libraries Government Documents Department
open access

Search for B0 to K*+ K*-

Description: The authors report the results of a search for the decay B{sup 0} {yields} K*{sup +}K*{sup -} with a sample of 454 {+-} 5 million B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the Stanford Linear Accelerator Center. They obtain an upper limit at the 90% confidence level on the branching fraction for {Beta}(B{sup 0} {yields} K*{sup +}K*{sup -}) < 2.0 x 10{sup -6}, assuming the decay is fully longitudinally polarized.
Date: August 7, 2008
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department
open access

Interlayer Interaction and Electronic Screening in MultilayerGraphene

Description: The unusual transport properties of graphene are the direct consequence of a peculiar bandstructure near the Dirac point. We determine the shape of the {pi} bands and their characteristic splitting, and find the transition from two-dimensional to bulk character for 1 to 4 layers of graphene by angle-resolved photoemission. By detailed measurements of the {pi} bands we derive the stacking order, layer-dependent electron potential, screening length and strength of interlayer interaction by compar… more
Date: June 7, 2007
Creator: Ohta, Taisuke; Bostwick, Aaron; McChesney, J.L.; Seyller, Thomas; Horn, Karsten & Rotenberg, Eli
Partner: UNT Libraries Government Documents Department
open access

MODELING OF NI-CR-MO BASED ALLOYS: PART II - KINETICS

Description: The CALPHAD approach is applied to kinetic studies of phase transformations and aging of prototypes of Ni-Cr-Mo-based alloys selected for waste disposal canisters in the Yucca Mountain Project (YMP). Based on a previous study on alloy stability for several candidate alloys, the thermodynamic driving forces together with a newly developed mobility database have been used to analyze diffusion-controlled transformations in these Ni-based alloys. Results on precipitation of the Ni{sub 2}Cr-ordered … more
Date: July 7, 2006
Creator: Turchi, P A; Kaufman, L & Liu, Z
Partner: UNT Libraries Government Documents Department
open access

The Extinction Toward the Galactic Bulge from RR Lyrae Stars

Description: The authors present mean reddenings toward 3525 RR0 Lyrae stars from the Galactic bulge fields of the MACHO Survey. These reddenings are determined using the color at minimum V-band light of the RR0 Lyrae stars themselves and are found to be in general agreement with extinction estimates at the same location obtained from other methods. Using 3256 stars located in the Galactic Bulge, they derive the selective extinction coefficient R{sub V,VR} = A{sub V}/E(V-R) = 4.2 {+-} 0.2. this value is wha… more
Date: November 7, 2007
Creator: Kunder, A.; Popowski, P.; Cook, K. & Chaboyer, B.
Partner: UNT Libraries Government Documents Department
open access

Passive Spectroscopy Bolometers, Grating- And X-Ray Imaging Crystal Spectrometers

Description: This tutorial gives a brief introduction into passive spectroscopy and describes the working principles of bolometers, a high-resolution grating spectrometer, and a novel X-ray imaging crystal spectrometer, which is of particular interest for profile measurements of the ion temperature and plasma rotation velocity on ITER and future burning plasma experiments.
Date: November 7, 2007
Creator: Bitter, M.; Hill, K. W.; Scott, S.; Paul, S.; Ince-Cushmann, A.; Reinke, M. et al.
Partner: UNT Libraries Government Documents Department
open access

Quantum entanglement of baby universes

Description: We study quantum entanglements of baby universes which appear in non-perturbative corrections to the OSV formula for the entropy of extremal black holes in type IIA string theory compactified on the local Calabi-Yau manifold defined as a rank 2 vector bundle over an arbitrary genus G Riemann surface. This generalizes the result for G=1 in hep-th/0504221. Non-perturbative terms can be organized into a sum over contributions from baby universes, and the total wave-function is their coherent super… more
Date: December 7, 2006
Creator: Essman, Eric P.; Aganagic, Mina; Okuda, Takuya & Ooguri, Hirosi
Partner: UNT Libraries Government Documents Department
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