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Kinetics of phase growth in the Cu-Sn system and application to composite Nb3Sn strands

Description: Nb{sub 3}Sn is the superconductor most used in the R and D of high field accelerator magnets by either the wind and react or the react and wind technique. In order to program the low temperature steps of the heat treatment, the growth kinetics of Cu-Sn intermetallics was investigated as a function of duration and temperature. The diffusion constants of {eta}, {var_epsilon} and {delta} phases between 150 and 550 C were evaluated using Cu-Sn model samples. Statistical and systematic errors were thoroughly evaluated for an accurate data analysis. Next the behavior of Internal Tin and Modified Jelly Roll Nb{sub 3}Sn composites was compared with the model predictions.
Date: November 18, 2002
Creator: al.1, Emanuela Barzi et
Partner: UNT Libraries Government Documents Department

Hadronic Contributions to R and G-2 from Initial-State-Radiation Data

Description: I review the recent efforts to improve the precision of the prediction of the anomalous moment of the muon, in particular of the hadronic contribution of the vacuum polarization, which is the contribution with the largest uncertainty. Focus is given to the recent result for e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} by the BaBar collaboration, obtained using events with radiation in the initial state.
Date: April 6, 2012
Creator: Bernard, Denis, 1 & Polytechnique, /Ecole
Partner: UNT Libraries Government Documents Department

Spatial filter lens design for the main laser of the National Ignition Facility

Description: The National Ignition Facility (NIF), being designed and constructed at Lawrence Livermore National Laboratory (LLNL), comprises 192 laser beams The lasing medium is neodymium in phosphate glass with a fundamental frequency (1{omega}) of 1 053{micro}m Sum frequency generation in a pair of conversion crystals (KDP/KD*P) will produce 1 8 megajoules of the third harmonic light (3{omega} or {lambda}=351{micro}m) at the target The purpose of this paper is to provide the lens design community with the current lens design details of the large optics in the Main Laser This paper describes the lens design configuration and design considerations of the Main Laser The Main Laser is 123 meters long and includes two spatial filters one 13 5 meters and one 60 meters These spatial filters perform crucial beam filtering and relaying functions We shall describe the significant lens design aspects of these spatial filter lenses which allow them to successfully deliver the appropriate beam characteristic onto the target For an overview of NIF please see ``Optical system design of the National Ignition Facility,`` by R Edward English. et al also found in this volume.
Date: June 5, 1998
Creator: Korniski, R. J., Optics 1 Inc, Westlake Village, CA
Partner: UNT Libraries Government Documents Department

Conceptual Design of A 1-2 GeV Synchroton Radiation Source

Description: A description is presented of the conceptual design of the Lawrence Berkeley Laboratory 1-2 GeV Synchrotron Radiation Source, which is designed to produce ultraviolet and soft x-ray radiation. The facility consists of an injection system (linac plus booster synchrotron), a low emittance storage ring optimized at 1.5 GeV, several insertion devices (wigglers and undulators) located in the storage ring straight sections, and beam lines from the insertion devices and bending magnets. Storage ring performance is analyzed in terms of lattice, collective instabilities and beam lifetime. The injection system and its performance are discussed. Spectral characteristics of the radiation are presented.
Date: August 1, 1986
Creator: St, The 1-2 GeV Synchrotron Radiation Source Design
Partner: UNT Libraries Government Documents Department

Large Angular Jump Mechanism Observed for Hydrogen Bond Exchange in Aqueous Perchlorate Solution

Description: The mechanism for hydrogen bond (H-bond) switching in solution has remained subject to debate despite extensive experimental and theoretical studies. We have applied polarization-selective multidimensional vibrational spectroscopy to investigate the H-bond exchange mechanism in aqueous NaClO{sub 4} solution. The results show that a water molecule shifts its donated H-bonds between water and perchlorate acceptors by means of large, prompt angular rotation. Using a jump-exchange kinetic model, we extract an average jump angle of 49 {+-} 4{sup o}, in qualitative agreement with the jump angle observed in molecular dynamics simulations of the same aqueous NaClO{sub 4} solution.
Date: June 11, 2010
Creator: Ji, Minbiao; /SLAC, PULSE /Stanford U., Phys. Dept.; Odelius3, Michael; U., /Stockholm; Gaffney1, K.J. & /aff SLAC, PULSE
Partner: UNT Libraries Government Documents Department

Infrared birefringence imaging of residual stress and bulk defects in multicrystalline silicon

Description: This manuscript concerns the application of infrared birefringence imaging (IBI) to quantify macroscopic and microscopic internal stresses in multicrystalline silicon (mc-Si) solar cell materials. We review progress to date, and advance four closely related topics. (1) We present a method to decouple macroscopic thermally-induced residual stresses and microscopic bulk defect related stresses. In contrast to previous reports, thermally-induced residual stresses in wafer-sized samples are generally found to be less than 5 MPa, while defect-related stresses can be several times larger. (2) We describe the unique IR birefringence signatures, including stress magnitudes and directions, of common microdefects in mc-Si solar cell materials including: {beta}-SiC and {beta}-Si{sub 3}N{sub 4} microdefects, twin bands, nontwin grain boundaries, and dislocation bands. In certain defects, local stresses up to 40 MPa can be present. (3) We relate observed stresses to other topics of interest in solar cell manufacturing, including transition metal precipitation, wafer mechanical strength, and minority carrier lifetime. (4) We discuss the potential of IBI as a quality-control technique in industrial solar cell manufacturing.
Date: May 5, 2010
Creator: Ganapati, Vidya; Schoenfelder, Stephan; Castellanos, Sergio; Oener, Sebastian; Koepge, Ringo; Sampson, Aaron et al.
Partner: UNT Libraries Government Documents Department

Cluster expansion of fcc Pd-V intermetallics

Description: A cluster expansion is used to compute fcc ground states from first principles for the Pd-V system. Intermetallic structures are not assumed but derived rigorously by minimizing the configurational energy subject to linear constraints. A large number of concentration-independent interactions are calculated by the method of direct configurational averaging. Agreement with the fcc-based portion of the experimentally-determined Pd-V phase diagram is quite satisfactory. 25 refs., 2 figs.
Date: June 1, 1991
Creator: de Fontaine, D.; Wolverton, C.; Ceder, G. (Lawrence Berkeley Lab., CA (United States)) & Dreysse, H. (Nancy-1 Univ., 54 (France). Lab. de Physique du Solide)
Partner: UNT Libraries Government Documents Department

Spontaneous Brain Activity as a Source of Ideal 1/f Noise

Description: In this article, the authors study the electroencephalogram (EEG) of 30 closed-eye subjects with a technique of analysis recently proposed to detect punctual events signaling rapid transitions between different metastable states.
Date: December 18, 2009
Creator: Allegrini, Paolo; Menicucci, Danilo; Bedini, Remo; Fronzoni, Leone; Gemignani, Angelo; Grigolini, Paolo et al.
Partner: UNT College of Arts and Sciences

Neutron-antineutron oscillations in nuclei

Description: We briefly review the state of the art for extracting the period of neutron-antineutron oscillations from the lifetime of nuclei. The most recent data on nuclear stability provide a limit of 10{sup 8} s for the oscillation period. 13 refs.
Date: January 1, 1989
Creator: Dover, C.B.; Gal, A.; Richard, J.M. (Brookhaven National Lab., Upton, NY (USA); Hebrew Univ., Jerusalem (Israel). Racah Inst. of Physics & Grenoble-1 Univ., 38 (France). Inst. des Sciences Nucleaires)
Partner: UNT Libraries Government Documents Department

Ground state searches in fcc intermetallics

Description: A cluster expansion is used to predict the fcc ground states, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational energy subject to linear constraints. This ground state search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the ground state results with the fcc-based portions of the experimentally-determined phase diagrams under consideration.
Date: December 1, 1991
Creator: Wolverton, C.; de Fontaine, D. (Lawrence Berkeley Lab., CA (United States)); Ceder, G. (Massachusetts Inst. of Tech., Cambridge, MA (United States)) & Dreysse, H. (Nancy-1 Univ., 54 (France). Lab. de Physique du Solide)
Partner: UNT Libraries Government Documents Department

Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.

Description: Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented by products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle.
Date: February 26, 2008
Creator: 1Harry Reid Center for Environmental Studies, Nuclear Science and Technology Division, University of Nevada, Las Vegas, Las Vegas, NV, 89154-4006; Gong, Cynthia-May S; Poineau, Frederic; Lukens, Wayne W & Czerwinski, Kenneth R.
Partner: UNT Libraries Government Documents Department

CYP1B1 expression, a potential risk factor for breast cancer

Description: CYP1B1 expression in non-tumor breast tissue from breast cancer patients and cancer-free individuals was determined to test the hypothesis that high CYP1B1 expression is a risk factor for breast cancer. Large interindividual variations in CYP1B1 expression were found with CYP1B1 levels notably higher in breast cancer patients than cancer-free individuals. The results indicate that CYP1B1 might play a role in breast cancer either through increased PAH activation or through metabolism of endogenous estrogen to a carcinogenic derivative.
Date: May 31, 2001
Creator: Goth-Goldstein, Regine; Erdmann, Christine A. & Russell, Marion
Partner: UNT Libraries Government Documents Department

Stress Activation of a Bean Hydroxyproline-Rich Glycoprotein Promoter is Superimposed on a Pattern of Tissue-Specific Developmental Expression

Description: Article discussing stress activation of a bean hydroxyproline-rich glycoprotein promoter superimposed on a pattern of tissue-specific developmental expression.
Date: September 1, 1995
Creator: Wycoff, Keith L.; Powell, Patricia A.; Gonzales, Robert A.; Corbin, David R.; Lamb, Christopher J. & Dixon, R. A.
Partner: UNT College of Arts and Sciences

Complete genome sequence of Thauera aminoaromatica strain MZ1T

Description: Article discussing research on the complete genome sequence of Thauera aminoaromatica strain MZ1T.
Date: 2012
Creator: Jiang, Ke; Sanseverino, John; Chauhan, Archana; Lucas, Susan; Copeland, Alex; Lapidus, Alla et al.
Partner: UNT College of Arts and Sciences