National Library of Energy BETA

Sample records for determination improved structure

  1. Improving the chances of successful protein structure determination with a random forest classifier

    SciTech Connect (OSTI)

    Jahandideh, Samad [Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92307 (United States); Joint Center for Structural Genomics, (United States); Jaroszewski, Lukasz; Godzik, Adam, E-mail: adam@burnham.org [Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92307 (United States); Joint Center for Structural Genomics, (United States); University of California, San Diego, La Jolla, California (United States)

    2014-03-01

    Using an extended set of protein features calculated separately for protein surface and interior, a new version of XtalPred based on a random forest classifier achieves a significant improvement in predicting the success of structure determination from the primary amino-acid sequence. Obtaining diffraction quality crystals remains one of the major bottlenecks in structural biology. The ability to predict the chances of crystallization from the amino-acid sequence of the protein can, at least partly, address this problem by allowing a crystallographer to select homologs that are more likely to succeed and/or to modify the sequence of the target to avoid features that are detrimental to successful crystallization. In 2007, the now widely used XtalPred algorithm [Slabinski et al. (2007 ?), Protein Sci.16, 24722482] was developed. XtalPred classifies proteins into five crystallization classes based on a simple statistical analysis of the physicochemical features of a protein. Here, towards the same goal, advanced machine-learning methods are applied and, in addition, the predictive potential of additional protein features such as predicted surface ruggedness, hydrophobicity, side-chain entropy of surface residues and amino-acid composition of the predicted protein surface are tested. The new XtalPred-RF (random forest) achieves significant improvement of the prediction of crystallization success over the original XtalPred. To illustrate this, XtalPred-RF was tested by revisiting target selection from 271 Pfam families targeted by the Joint Center for Structural Genomics (JCSG) in PSI-2, and it was estimated that the number of targets entered into the protein-production and crystallization pipeline could have been reduced by 30% without lowering the number of families for which the first structures were solved. The prediction improvement depends on the subset of targets used as a testing set and reaches 100% (i.e. twofold) for the top class of predicted targets.

  2. Structure of CPV17 polyhedrin determined by the improved analysis of serial femtosecond crystallographic data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ginn, Helen M.; Messerschmidt, Marc; Ji, Xiaoyun; Zhang, Hanwen; Axford, Danny; Gildea, Richard J.; Winter, Graeme; Brewster, Aaron S.; Hattne, Johan; Wagner, Armin; et al

    2015-03-09

    The X-ray free-electron laser (XFEL) allows the analysis of small weakly diffracting protein crystals, but has required very many crystals to obtain good data. Here we use an XFEL to determine the room temperature atomic structure for the smallest cytoplasmic polyhedrosis virus polyhedra yet characterized, which we failed to solve at a synchrotron. These protein microcrystals, roughly a micron across, accrue within infected cells. We use a new physical model for XFEL diffraction, which better estimates the experimental signal, delivering a high-resolution XFEL structure (1.75 Å), using fewer crystals than previously required for this resolution. The crystal lattice and proteinmore » core are conserved compared with a polyhedrin with less than 10% sequence identity. We explain how the conserved biological phenotype, the crystal lattice, is maintained in the face of extreme environmental challenge and massive evolutionary divergence. Our improved methods should open up more challenging biological samples to XFEL analysis.« less

  3. Crystal structure determination of Efavirenz

    SciTech Connect (OSTI)

    Popeneciu, Horea Dumitru, Ristoiu; Tripon, Carmen Borodi, Gheorghe Pop, Mihaela Maria

    2015-12-23

    Needle-shaped single crystals of the title compound, C{sub 14}H{sub 9}ClF{sub 3}NO{sub 2}, were obtained from a co-crystallization experiment of Efavirenz with maleic acid in a (1:1) ratio, using methanol as solvent. Crystal structure determination at room temperature revealed a significant anisotropy of the lattice expansion compared to the previously reported low-temperature structure. In both low- and room temperature structures the cyclopropylethynyl fragment in one of the asymmetric unit molecules is disordered. While at low-temperature only one C atom exhibits positional disorder, at room temperature the disorder is present for two C atoms of the cyclopropane ring.

  4. IMPROVED V II log(gf) VALUES, HYPERFINE STRUCTURE CONSTANTS, AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

    SciTech Connect (OSTI)

    Wood, M. P.; Lawler, J. E.; Den Hartog, E. A.; Sneden, C.; Cowan, J. J. E-mail: jelawler@wisc.edu E-mail: chris@verdi.as.utexas.edu

    2014-10-01

    New experimental absolute atomic transition probabilities are reported for 203 lines of V II. Branching fractions are measured from spectra recorded using a Fourier transform spectrometer and an echelle spectrometer. The branching fractions are normalized with radiative lifetime measurements to determine the new transition probabilities. Generally good agreement is found between this work and previously reported V II transition probabilities. Two spectrometers, independent radiometric calibration methods, and independent data analysis routines enable a reduction in systematic uncertainties, in particular those due to optical depth errors. In addition, new hyperfine structure constants are measured for selected levels by least squares fitting line profiles in the FTS spectra. The new V II data are applied to high resolution visible and UV spectra of the Sun and metal-poor star HD 84937 to determine new, more accurate V abundances. Lines covering a range of wavelength and excitation potential are used to search for non-LTE effects. Very good agreement is found between our new solar photospheric V abundance, log ε(V) = 3.95 from 15 V II lines, and the solar-system meteoritic value. In HD 84937, we derive [V/H] = –2.08 from 68 lines, leading to a value of [V/Fe] = 0.24.

  5. Continuous mutual improvement of macromolecular structure models...

    Office of Scientific and Technical Information (OSTI)

    ... Country of Publication: United States Language: English Subject: 59 BASIC BIOLOGICAL SCIENCES; 96 KNOWLEDGE MANAGEMENT AND PRESERVATION structure determination; model quality; data ...

  6. Seismicity and Improved Velocity Structure in Kuwait

    SciTech Connect (OSTI)

    Gok, R M; Rodgers, A J; Al-Enezi, A

    2006-01-26

    relative arrival times. We obtained {approx}1500 absolute P and S arrival times and {approx}3200 P and S wave arrival time differences. Event locations do not change greatly when 3D velocity structure is included. Three-dimensional velocity structure, where resolvable, does not differ greatly from our optimized 1D model, indicating that the improved 1D model is adequate for routine event location. Finally, we calculated moment magnitudes, MW, for nearly 155 events using the coda magnitude technique of Mayeda et al., (2003). The fact that most of the relocated events occur below the known sedimentary structures extending to 7 km suggests that they are tectonic in origin. Shallow events within the sedimentary crust in the (southern) Minagish region may be related to oil field activities, although the current study cannot unambiguously determine the source of current seismicity in Kuwait. The improved velocity model reduces the scatter of travel time residuals relative to the locations reported in the KNSN bulletin and may be used for ground motion prediction and hazard estimate studies in Kuwait.

  7. Analytical Improvements in PV Degradation Rate Determination

    SciTech Connect (OSTI)

    Jordan, D. C.; Kurtz, S. R.

    2011-02-01

    As photovoltaic (PV) penetration of the power grid increases, it becomes vital to know how decreased power output may affect cost over time. In order to predict power delivery, the decline or degradation rates must be determined accurately. For non-spectrally corrected data several complete seasonal cycles (typically 3-5 years) are required to obtain reasonably accurate degradation rates. In a rapidly evolving industry such a time span is often unacceptable and the need exists to determine degradation rates accurately in a shorter period of time. Occurrence of outliers and data shifts are two examples of analytical problems leading to greater uncertainty and therefore to longer observation times. In this paper we compare three methodologies of data analysis for robustness in the presence of outliers, data shifts and shorter measurement time periods.

  8. Heat pipe with improved wick structures

    DOE Patents [OSTI]

    Benson, David A.; Robino, Charles V.; Palmer, David W.; Kravitz, Stanley H.

    2000-01-01

    An improved planar heat pipe wick structure having projections formed by micromachining processes. The projections form arrays of interlocking, semi-closed structures with multiple flow paths on the substrate. The projections also include overhanging caps at their tops to increase the capillary pumping action of the wick structure. The capped projections can be formed in stacked layers. Another layer of smaller, more closely spaced projections without caps can also be formed on the substrate in between the capped projections. Inexpensive materials such as Kovar can be used as substrates, and the projections can be formed by electrodepositing nickel through photoresist masks.

  9. Protein Structure Determination Using Protein Threading and Sparse NMR Data

    SciTech Connect (OSTI)

    Crawford, O.H.; Einstein, J.R.; Xu, D.; Xu, Y.

    1999-11-14

    It is well known that the NMR method for protein structure determination applies to small proteins and that its effectiveness decreases very rapidly as the molecular weight increases beyond about 30 kD. We have recently developed a method for protein structure determination that can fully utilize partial NMR data as calculation constraints. The core of the method is a threading algorithm that guarantees to find a globally optimal alignment between a query sequence and a template structure, under distance constraints specified by NMR/NOE data. Our preliminary tests have demonstrated that a small number of NMR/NOE distance restraints can significantly improve threading performance in both fold recognition and threading-alignment accuracy, and can possibly extend threading's scope of applicability from structural homologs to structural analogs. An accurate backbone structure generated by NMR-constrained threading can then provide a significant amount of structural information, equivalent to that provided by the NMR method with many NMR/NOE restraints; and hence can greatly reduce the amount of NMR data typically required for accurate structure determination. Our preliminary study suggests that a small number of NMR/NOE restraints may suffice to determine adequately the all-atom structure when those restraints are incorporated in a procedure combining threading, modeling of loops and sidechains, and molecular dynamics simulation. Potentially, this new technique can expand NMR's capability to larger proteins.

  10. Improving The Picture Of Nucleon Structure | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Improving The Picture Of Nucleon Structure Improving The Picture Of Nucleon Structure March 1999 In a series of experiments at the Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab), researchers are moving toward a substantially improved picture of nucleon structure and behavior. "There are clearly new things we see in the data," says Volker Burkert, a senior staff scientist in the Lab's Physics Division. "We see preliminary evidence for

  11. Power converter having improved terminal structure

    DOE Patents [OSTI]

    Radosevich, Lawrence D.; Kannenberg, Daniel G.; Phillips, Mark G.; Kaishian, Steven C.

    2007-03-06

    A terminal structure for power electronics circuits reduces the need for a DC bus and thereby the incidence of parasitic inductance. The structure is secured to a support that may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as by direct contact between the terminal assembly and AC and DC circuit components. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  12. Improved determination of the width of the top quark

    SciTech Connect (OSTI)

    Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatia S.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Graf C. P.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; La Cruz I. Heredia-De; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li H.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; et al.

    2012-05-04

    We present an improved determination of the total width of the top quark, {Gamma}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Gamma}{sub t} is extracted from the partial decay width {Gamma}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Gamma}(t {yields} Wb) is obtained from the t-channel single top-quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Gamma}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb}| < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.

  13. Automating the determination of 3D protein structure

    SciTech Connect (OSTI)

    Rayl, K.D.

    1993-12-31

    The creation of an automated method for determining 3D protein structure would be invaluable to the field of biology and presents an interesting challenge to computer science. Unfortunately, given the current level of protein knowledge, a completely automated solution method is not yet feasible, therefore, our group has decided to integrate existing databases and theories to create a software system that assists X-ray crystallographers in specifying a particular protein structure. By breaking the problem of determining overall protein structure into small subproblems, we hope to come closer to solving a novel structure by solving each component. By generating necessary information for structure determination, this method provides the first step toward designing a program to determine protein conformation automatically.

  14. Crystal growth and structure determinations of potassium hafnates...

    Office of Scientific and Technical Information (OSTI)

    Crystal growth and structure determinations of potassium hafnates: Ksub 2Hfsub 2Osub 5 and Ksub 4Hfsub 5Osub 12 Citation Details In-Document Search Title: Crystal ...

  15. Spectrometric Determination of Molecular Structural Evolution at the Solid

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Electrolyte Interphase in Lithium-Ion Batteries - Joint Center for Energy Storage Research August 19, 2015, Research Highlights Spectrometric Determination of Molecular Structural Evolution at the Solid Electrolyte Interphase in Lithium-Ion Batteries The first of its kind capability that allows the study of molecular structure at solid-liquid interface Direct probing the molecular structure of solid electrolyte interface layer operando for lithium-ion battery Combining of in-situ TEM and

  16. Structural determination of intact proteins using mass spectrometry

    DOE Patents [OSTI]

    Kruppa, Gary; Schoeniger, Joseph S.; Young, Malin M.

    2008-05-06

    The present invention relates to novel methods of determining the sequence and structure of proteins. Specifically, the present invention allows for the analysis of intact proteins within a mass spectrometer. Therefore, preparatory separations need not be performed prior to introducing a protein sample into the mass spectrometer. Also disclosed herein are new instrumental developments for enhancing the signal from the desired modified proteins, methods for producing controlled protein fragments in the mass spectrometer, eliminating complex microseparations, and protein preparatory chemical steps necessary for cross-linking based protein structure determination.Additionally, the preferred method of the present invention involves the determination of protein structures utilizing a top-down analysis of protein structures to search for covalent modifications. In the preferred method, intact proteins are ionized and fragmented within the mass spectrometer.

  17. Award Fee Determination Shows Performance Improvement in WTP Contractor

    Broader source: Energy.gov [DOE]

    RICHLAND, Wash. – EM Office of River Protection (ORP) Waste Treatment and Immobilization Plant (WTP) contractor Bechtel National Inc. improved its performance slightly in calendar year 2015 compared to the last half of 2014, earning 66 percent of its possible award fee, or $8.31 million out of a possible $12.6 million.

  18. The Determination of Molecular Structure from Rotational Spectra

    DOE R&D Accomplishments [OSTI]

    Laurie, V. W.; Herschbach, D. R.

    1962-07-01

    An analysis is presented concerning the average molecular configuration variations and their effects on molecular structure determinations. It is noted that the isotopic dependence of the zero-point is often primarily governed by the isotopic variation of the average molecular configuration. (J.R.D.)

  19. Method and apparatus for determining material structural integrity

    DOE Patents [OSTI]

    Pechersky, Martin

    1996-01-01

    A non-destructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis techniques to determine the damping loss factor of a material. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity as a function of time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method. If an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the amount of coil current used in vibrating the magnet. If a reciprocating transducer is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by a force gauge in the reciprocating transducer. Using known vibrational analysis methods, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity measurements. The damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.

  20. Method and apparatus for determining material structural integrity

    DOE Patents [OSTI]

    Pechersky, M.J.

    1994-01-01

    Disclosed are a nondestructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis to determine the damping loss factor. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity vs time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method: if an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the coil current. If a reciprocating transducer is used, the vibrational force is determined by a force gauge in the transducer. Using vibrational analysis, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity data. Damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.

  1. Simple surface structure determination from Fourier transforms of angle-resolved photoemission extended fine structure

    SciTech Connect (OSTI)

    Zheng, Y. |; Shirley, D.A.

    1995-02-01

    The authors show by Fourier analyses of experimental data, with no further treatment, that the positions of all the strong peaks in Fourier transforms of angle-resolved photoemission extended fine structure (ARPEFS) from adsorbed surfaces can be explicitly predicted from a trial structure with an accuracy of about {+-} 0.3 {angstrom} based on a single-scattering cluster model together with the concept of a strong backscattering cone, and without any additional analysis. This characteristic of ARPEFS Fourier transforms can be developed as a simple method for determining the structures of adsorbed surfaces to an accuracy of about {+-} 0.1 {angstrom}.

  2. Method for improving performance of highly stressed electrical insulating structures

    DOE Patents [OSTI]

    Wilson, Michael J.; Goerz, David A.

    2002-01-01

    Removing the electrical field from the internal volume of high-voltage structures; e.g., bushings, connectors, capacitors, and cables. The electrical field is removed from inherently weak regions of the interconnect, such as between the center conductor and the solid dielectric, and places it in the primary insulation. This is accomplished by providing a conductive surface on the inside surface of the principal solid dielectric insulator surrounding the center conductor and connects the center conductor to this conductive surface. The advantage of removing the electric fields from the weaker dielectric region to a stronger area improves reliability, increases component life and operating levels, reduces noise and losses, and allows for a smaller compact design. This electric field control approach is currently possible on many existing products at a modest cost. Several techniques are available to provide the level of electric field control needed. Choosing the optimum technique depends on material, size, and surface accessibility. The simplest deposition method uses a standard electroless plating technique, but other metalization techniques include vapor and energetic deposition, plasma spraying, conductive painting, and other controlled coating methods.

  3. Apparatus for improving performance of electrical insulating structures

    DOE Patents [OSTI]

    Wilson, Michael J.; Goerz, David A.

    2002-01-01

    Removing the electrical field from the internal volume of high-voltage structures; e.g., bushings, connectors, capacitors, and cables. The electrical field is removed from inherently weak regions of the interconnect, such as between the center conductor and the solid dielectric, and places it in the primary insulation. This is accomplished by providing a conductive surface on the inside surface of the principal solid dielectric insulator surrounding the center conductor and connects the center conductor to this conductive surface. The advantage of removing the electric fields from the weaker dielectric region to a stronger area improves reliability, increases component life and operating levels, reduces noise and losses, and allows for a smaller compact design. This electric field control approach is currently possible on many existing products at a modest cost. Several techniques are available to provide the level of electric field control needed. Choosing the optimum technique depends on material, size, and surface accessibility. The simplest deposition method uses a standard electroless plating technique, but other metalization techniques include vapor and energetic deposition, plasma spraying, conductive painting, and other controlled coating methods.

  4. Apparatus for improving performance of electrical insulating structures

    DOE Patents [OSTI]

    Wilson, Michael J.; Goerz, David A.

    2004-08-31

    Removing the electrical field from the internal volume of high-voltage structures; e.g., bushings, connectors, capacitors, and cables. The electrical field is removed from inherently weak regions of the interconnect, such as between the center conductor and the solid dielectric, and places it in the primary insulation. This is accomplished by providing a conductive surface on the inside surface of the principal solid dielectric insulator surrounding the center conductor and connects the center conductor to this conductive surface. The advantage of removing the electric fields from the weaker dielectric region to a stronger area improves reliability, increases component life and operating levels, reduces noise and losses, and allows for a smaller compact design. This electric field control approach is currently possible on many existing products at a modest cost. Several techniques are available to provide the level of electric field control needed. Choosing the optimum technique depends on material, size, and surface accessibility. The simplest deposition method uses a standard electroless plating technique, but other metalization techniques include vapor and energetic deposition, plasma spraying, conductive painting, and other controlled coating methods.

  5. Actions taken by DOD on GAO recommendations to improve spare parts requirements determination

    SciTech Connect (OSTI)

    Not Available

    1985-04-30

    GAO found that actions taken by the military services and DOD to improve the spare parts requirements determination process, in response to prior GAO report recommendations, have resulted in estimated cost savings of over $800 million during the past 5 years. Additional actions in process should result in further estimated savings of over $500 million.

  6. Analysis of phases in the structure determination of an icosahedral virus

    SciTech Connect (OSTI)

    Plevka, Pavel; Kaufmann, Bärbel; Rossmann, Michael G.

    2012-03-15

    The constraints imposed on structure-factor phases by noncrystallographic symmetry (NCS) allow phase improvement, phase extension to higher resolution and hence ab initio phase determination. The more numerous the NCS redundancy and the greater the volume used for solvent flattening, the greater the power for phase determination. In a case analyzed here the icosahedral NCS phasing appeared to have broken down, although later successful phase extension was possible when the envelope around the NCS region was tightened. The phases from the failed phase-determination attempt fell into four classes, all of which satisfied the NCS constraints. These four classes corresponded to the correct solution, opposite enantiomorph, Babinet inversion and opposite enantiomorph with Babinet inversion. These incorrect solutions can be seeded from structure factors belonging to reciprocal-space volumes that lie close to icosahedral NCS axes where the structure amplitudes tend to be large and the phases tend to be 0 or {pi}. Furthermore, the false solutions can spread more easily if there are large errors in defining the envelope designating the region in which NCS averaging is performed.

  7. Improved input and output couplers for SC acceleration structure

    SciTech Connect (OSTI)

    Solyak, N.; Gonin, I.; Latina, A.; Lunin, A.; Poloubotko, V.; Yakovlev, V.; /Fermilab

    2009-04-01

    Different couplers are described that allow the reduction of both transverse wake potential and RF kick in the SC acceleration structure of ILC. A simple rotation of the couplers reducing the RF kick and transverse wake kick is discussed for both the main linac and bunch compressors, along with possible limitations of this method. Designs of a coupler unit are presented which preserve axial symmetry of the structure, and provide reduced both the RF kick and transverse wake field.

  8. Corrosion-resistant multilayer structures with improved reflectivity

    DOE Patents [OSTI]

    Soufli, Regina; Fernandez-Perea, Monica; Robinson, Jeff C.

    2013-04-09

    In one general embodiment, a thin film structure includes a substrate; a first corrosion barrier layer above the substrate; a reflective layer above the first corrosion barrier layer, wherein the reflective layer comprises at least one repeating set of sub-layers, wherein one of the sub-layers of each set of sub-layers being of a corrodible material; and a second corrosion barrier layer above the reflective layer. In another general embodiment, a system includes an optical element having a thin film structure as recited above; and an image capture or spectrometer device. In a further general embodiment, a laser according to one embodiment includes a light source and the thin film structure as recited above.

  9. Method and structure for an improved data reformatting procedure

    DOE Patents [OSTI]

    Chatterjee, Siddhartha; Gunnels, John A.; Gustavson, Fred Gehrung

    2009-06-30

    A method (and structure) of managing memory in which a low-level mechanism is executed to signal, in a sequence of instructions generated at a higher level, that at least a portion of a contiguous area of memory is permitted to be overwritten.

  10. Method for improve x-ray diffraction determinations of residual stress in nickel-base alloys

    DOE Patents [OSTI]

    Berman, Robert M.; Cohen, Isadore

    1990-01-01

    A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys which comprises covering part of a predetermined area of the surface of a nickel-base alloy with a dispersion, exposing the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample.

  11. Method for improving x-ray diffraction determinations of residual stress in nickel-base alloys

    DOE Patents [OSTI]

    Berman, R.M.; Cohen, I.

    1988-04-26

    A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys is discussed. Part of a predetermined area of the surface of a nickel-base alloy is covered with a dispersion. This exposes the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose, since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample. 2 figs.

  12. Improved structural systems for earth sheltered housing. Structural supplement to the design program

    SciTech Connect (OSTI)

    Behr, R.

    1981-10-01

    Additional engineering information is provided with regard to the structural analysis and design of thin shell concrete structures. The design program has tentatively demonstrated the overall architectural and marketing feasibility of curved, thin shell structural systems for earth sheltered housing. This supplement will address the structural feasibility question by presenting a complete manual analysis and structural design of an earth sheltered dome/tension ring/wall structural system, and also by presenting the results of a parametric sensitivity study of the dome/ring/wall configuration with respect to variations in span and rise for a three foot soil loading condition. Double curvature dome configurations are emphasized in this structural supplement because their analysis is not extensively addressed in earth sheltered housing literature.

  13. An improved thin film approximation to accurately determine the optical conductivity of graphene from infrared transmittance

    SciTech Connect (OSTI)

    Weber, J. W.; Bol, A. A. [Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Sanden, M. C. M. van de [Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Dutch Institute for Fundamental Energy Research (DIFFER), Nieuwegein (Netherlands)

    2014-07-07

    This work presents an improved thin film approximation to extract the optical conductivity from infrared transmittance in a simple yet accurate way. This approximation takes into account the incoherent reflections from the backside of the substrate. These reflections are shown to have a significant effect on the extracted optical conductivity and hence on derived parameters as carrier mobility and density. By excluding the backside reflections, the error for these parameters for typical chemical vapor deposited (CVD) graphene on a silicon substrate can be as high as 17% and 45% for the carrier mobility and density, respectively. For the mid- and near-infrared, the approximation can be simplified such that the real part of the optical conductivity is extracted without the need for a parameterization of the optical conductivity. This direct extraction is shown for Fourier transform infrared (FTIR) transmittance measurements of CVD graphene on silicon in the photon energy range of 3707000?cm{sup ?1}. From the real part of the optical conductivity, the carrier density, mobility, and number of graphene layers are determined but also residue, originating from the graphene transfer, is detected. FTIR transmittance analyzed with the improved thin film approximation is shown to be a non-invasive, easy, and accurate measurement and analysis method for assessing the quality of graphene and can be used for other 2-D materials.

  14. Two-station phase velocity determination for structure in North Africa

    SciTech Connect (OSTI)

    Hazler, S; Pasyanos, M; Sheehan, A; Walter, W

    1999-07-28

    The seismic structure of North Africa is poorly understood due to the relative paucity of stations and seismicity when compared to other continental regions of the world. A better understanding of the velocity structure in this area will allow improved models of travel times and regional phase amplitudes. Such models will improve location and identification capability in this region leading to more effective monitoring of the Comprehensive Nuclear-Test-Ban Treaty. Using regional-to-teleseismic Rayleigh and Love waves that traverse the area we can obtain information about the region's seismic structure by examining phase velocity as a function of period. We utilize earthquakes from the tectonically active regions bounding North Africa (Mediterranean, Red Sea, East African Rift, and Mid-Atlantic Ridge) recorded at broadband seismic stations distributed throughout the region. A two-station method is utilized to determine phase velocity information along the interstation segment of the ray path. The two-station method provides particular advantage in this region as it dramatically increases the number of events available to provide pure North African sampling. Bandpass filters are applied to the seismograms so that peaks and troughs may be correlated. The phase is unwrapped and a difference curve computed. The difference curve is then converted to a phase velocity dispersion curve. Phase velocity curves are constructed in the range of 10 to 120 seconds. Rayleigh and Love waves in this period range are most sensitive to the shear velocity structure of the lithosphere and can be used in combination with additional independent seismic observations (e.g. Pn tomography, surface wave group velocity tomography, receiver functions, etc.) to construct reliable velocity models. We compare velocities computed in this study to those generated from well known models for similar tectonic regions throughout the world in order to better define the tectonic setting of North Africa

  15. Determination of the Surface Structure of CeO2(111) by Low-Energy...

    Office of Scientific and Technical Information (OSTI)

    Title: Determination of the Surface Structure of CeO2(111) by Low-Energy Electron Diffraction. Abstract not provided. Authors: McCarty, Kevin F. ; Siegel, David A ; El Gabaly ...

  16. Structure symmetry determination and magnetic evolution in Sr2Ir1...

    Office of Scientific and Technical Information (OSTI)

    evolution in Sr2Ir1-xRhxO4 This content will become publicly available on November 23, 2016 Prev Next Title: Structure symmetry determination and magnetic evolution in ...

  17. Pairwise covariance adds little to secondary structure prediction but improves the prediction of non-canonical local structure

    SciTech Connect (OSTI)

    Bystroff, Christopher; Webb-Robertson, Bobbie-Jo M.

    2009-05-06

    Amino acid sequence probability distributions, or profiles, have been used successfully to predict secondary structure and local structure in proteins. Profile models assume the statistical independence of each position in the sequence, but the energetics of protein folding is better captured in a scoring function that is based on pairwise interactions, like a force field. I-sites motifs are short sequence/structure motifs that populate the protein structure database due to energy-driven convergent evolution. Here we show that a pairwise covariant sequence model does not predict alpha helix or beta strand significantly better overall than a profile-based model, but it does improve the prediction of certain loop motifs. The finding is best explained by considering secondary structure profiles as multivariant, all-or-none models, which subsume covariant models. Pairwise covariance is nonetheless present and energetically rational. Examples of negative design are present, where the covariances disfavor non-native structures. Measured pairwise covariances are shown to be statistically robust in cross-validation tests, as long as the amino acid alphabet is reduced to nine classes. We present an updated I-sites local structure motif library and web server that provide sequence covariance information for all types of local structure in globular proteins.

  18. Significantly Improving Regional Seismic Amplitude Tomography at Higher Frequencies by Determining S -Wave Bandwidth

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fisk, Mark D.; Pasyanos, Michael E.

    2016-05-03

    Characterizing regional seismic signals continues to be a difficult problem due to their variability. Calibration of these signals is very important to many aspects of monitoring underground nuclear explosions, including detecting seismic signals, discriminating explosions from earthquakes, and reliably estimating magnitude and yield. Amplitude tomography, which simultaneously inverts for source, propagation, and site effects, is a leading method of calibrating these signals. A major issue in amplitude tomography is the data quality of the input amplitude measurements. Pre-event and prephase signal-to-noise ratio (SNR) tests are typically used but can frequently include bad signals and exclude good signals. The deficiencies ofmore » SNR criteria, which are demonstrated here, lead to large calibration errors. To ameliorate these issues, we introduce a semi-automated approach to assess the bandwidth of a spectrum where it behaves physically. We determine the maximum frequency (denoted as Fmax) where it deviates from this behavior due to inflections at which noise or spurious signals start to bias the spectra away from the expected decay. We compare two amplitude tomography runs using the SNR and new Fmax criteria and show significant improvements to the stability and accuracy of the tomography output for frequency bands higher than 2 Hz by using our assessments of valid S-wave bandwidth. We compare Q estimates, P/S residuals, and some detailed results to explain the improvements. Lastly, for frequency bands higher than 4 Hz, needed for effective P/S discrimination of explosions from earthquakes, the new bandwidth criteria sufficiently fix the instabilities and errors so that the residuals and calibration terms are useful for application.« less

  19. Determining Orientational Structure of Diamondoid Thiols Attached to Silver Using Near Edge X-ray Absorption Fine Structure Spectroscopy

    SciTech Connect (OSTI)

    Willey, T M; Lee, J I; Fabbri, J D; Wang, D; Nielsen, M; Randel, J C; Schreiner, P R; Fokin, A A; Tkachenko, B A; Fokina, N A; Dahl, J P; Carlson, R K; Terminello, L J; Melosh, N A; van Buuren, T

    2008-10-07

    Near-edge x-ray absorption fine structure spectroscopy (NEXAFS) is a powerful tool for determination of molecular orientation in self-assembled monolayers and other surface-attached molecules. A general framework for using NEXAFS to simultaneously determine molecular tilt and twist of rigid molecules attached to surfaces is presented. This framework is applied to self-assembled monolayers of higher diamondoid, hydrocarbon molecules with cubic-diamond-cage structures. Diamondoid monolayers chemisorbed on metal substrates are known to exhibit interesting electronic and surface properties. This work compares molecular orientation in monolayers prepared on silver substrates using two different thiol positional isomers of [121]tetramantane, and thiols derived from two different pentamantane structural isomers, [1212]pentamantane and [1(2,3)4]pentamantane. The observed differences in monolayer structure demonstrate the utility and limitations of NEXAFS spectroscopy and the framework. The results also demonstrate the ability to control diamondoid assembly, in particular the molecular orientational structure, providing a flexible platform for the modification of surface properties with this exciting new class of nanodiamond materials.

  20. X-ray laser diffraction for structure determination of the rhodopsin-arrestin complex

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhou, X. Edward; Gao, Xiang; Barty, Anton; Kang, Yanyong; He, Yuanzheng; Liu, Wei; Ishchenko, Andrii; White, Thomas A.; Yefanov, Oleksandr; Han, Gye Won; et al

    2016-04-12

    Here, serial femtosecond X-ray crystallography (SFX) using an X-ray free electron laser (XFEL) is a recent advancement in structural biology for solving crystal structures of challenging membrane proteins, including G-protein coupled receptors (GPCRs), which often only produce microcrystals. An XFEL delivers highly intense X-ray pulses of femtosecond duration short enough to enable the collection of single diffraction images before significant radiation damage to crystals sets in. Here we report the deposition of the XFEL data and provide further details on crystallization, XFEL data collection and analysis, structure determination, and the validation of the structural model. The rhodopsin-arrestin crystal structure solvedmore » with SFX represents the first near-atomic resolution structure of a GPCR-arrestin complex, provides structural insights into understanding of arrestin-mediated GPCR signaling, and demonstrates the great potential of this SFX-XFEL technology for accelerating crystal structure determination of challenging proteins and protein complexes.« less

  1. Improved Structure and Fabrication of Large, High-Power KHPS Rotors - Final Scientific/Technical Report

    SciTech Connect (OSTI)

    Corren, Dean; Colby, Jonathan; Adonizio, Mary Ann

    2013-01-29

    Verdant Power, Inc, working in partnership with the National Renewable Energy Laboratory (NREL), Sandia National Laboratories (SNL), and the University of Minnesota St. Anthony Falls Laboratory (SAFL), among other partners, used evolving Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) models and techniques to improve the structure and fabrication of large, high-power composite Kinetic Hydropower System (KHPS) rotor blades. The objectives of the project were to: design; analyze; develop for manufacture and fabricate; and thoroughly test, in the lab and at full scale in the water, the improved KHPS rotor blade.

  2. How Clean is Safe? Improving the Effectiveness of Decontamination of Structures and People Following Chemical and Biological Incidents

    SciTech Connect (OSTI)

    Vogt , B.M.

    2003-04-03

    This report describes a U.S. Department of Energy, (DOE) Chemical and Biological National Security Program project that sought to establish what is known about decontamination of structures, objects, and people following an exposure to chemical or biological materials. Specifically we sought to identify the procedures and protocols used to determine when and how people or buildings are considered ''clean'' following decontamination. To fulfill this objective, the study systematically examined reported decontamination experiences to determine what procedures and protocols are currently employed for decontamination, the timeframe involved to initiate and complete the decontamination process, how the contaminants were identified, the factors determining when people were (or were not) decontaminated, the problems encountered during the decontamination process, how response efforts of agencies were coordinated, and the perceived social psychological effects on people who were decontaminated or who participated in the decontamination process. Findings and recommendations from the study are intended to aid decision-making and to improve the basis for determining appropriate decontamination protocols for recovery planners and policy makers for responding to chemical and biological events.

  3. Structural determinants of nuclear export signal orientation in binding to exportin CRM1

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fung, Ho Yee Joyce; Fu, Szu -Chin; Brautigam, Chad A.; Chook, Yuh Min

    2015-09-08

    The Chromosome Region of Maintenance 1 (CRM1) protein mediates nuclear export of hundreds of proteins through recognition of their nuclear export signals (NESs), which are highly variable in sequence and structure. The plasticity of the CRM1-NES interaction is not well understood, as there are many NES sequences that seem incompatible with structures of the NES-bound CRM1 groove. Crystal structures of CRM1 bound to two different NESs with unusual sequences showed the NES peptides binding the CRM1 groove in the opposite orientation (minus) to that of previously studied NESs (plus). A comparison of minus and plus NESs identified structural and sequencemore » determinants for NES orientation. The binding of NESs to CRM1 in both orientations results in a large expansion in NES consensus patterns and therefore a corresponding expansion of potential NESs in the proteome.« less

  4. Structural determinants of nuclear export signal orientation in binding to exportin CRM1

    SciTech Connect (OSTI)

    Fung, Ho Yee Joyce; Fu, Szu -Chin; Brautigam, Chad A.; Chook, Yuh Min

    2015-09-08

    The Chromosome Region of Maintenance 1 (CRM1) protein mediates nuclear export of hundreds of proteins through recognition of their nuclear export signals (NESs), which are highly variable in sequence and structure. The plasticity of the CRM1-NES interaction is not well understood, as there are many NES sequences that seem incompatible with structures of the NES-bound CRM1 groove. Crystal structures of CRM1 bound to two different NESs with unusual sequences showed the NES peptides binding the CRM1 groove in the opposite orientation (minus) to that of previously studied NESs (plus). A comparison of minus and plus NESs identified structural and sequence determinants for NES orientation. The binding of NESs to CRM1 in both orientations results in a large expansion in NES consensus patterns and therefore a corresponding expansion of potential NESs in the proteome.

  5. Unquenched determination of the kaon parameter B{sub K} from improved staggered fermions

    SciTech Connect (OSTI)

    Gamiz, Elvira; Collins, Sara; Davies, Christine T.H.; Lepage, G. Peter; Shigemitsu, Junko; Wingate, Matthew

    2006-06-01

    The use of improved staggered actions (HYP, Asqtad) has been proved to reduce the scaling corrections that affected previous calculations of B{sub K} with unimproved (standard) staggered fermions in the quenched approximation. This improved behavior allows us to perform a reliable calculation of B{sub K} including quark vacuum polarization effects, using the MILC configurations with n{sub f}=2+1 flavors of sea fermions. We perform such a calculation for a single lattice spacing, a=0.125 fm, and with kaons made up of degenerate quarks with m{sub s}/2. The valence strange quark mass m{sub s} is fixed to its physical value and we use two different values of the light sea quark masses. After a chiral extrapolation of the results to the physical value of the sea quark masses, we find B-circumflex{sub K}=0.83{+-}0.18, where the error is dominated by the uncertainty in the lattice to continuum matching at O({alpha}{sub s}{sup 2}). The matching will need to be improved to get the precision needed to make full use of the experimental data on {epsilon}{sub K} to constrain the unitarity triangle.

  6. Determination

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Determinants of Household Use of Selected Energy Star Appliances May 2016 Independent Statistics & Analysis www.eia.gov U.S. Department of Energy Washington, DC 20585 U.S. Energy Information Administration | Determinants of Household Use of Selected Energy Star Appliances i This report was prepared by the U.S. Energy Information Administration (EIA), the statistical and analytical agency within the U.S. Department of Energy. By law, EIA's data, analyses, and forecasts are independent of

  7. Improved Measurement of the Positive-Muon Lifetime and Determination of the Fermi Constant

    SciTech Connect (OSTI)

    Chitwood, D. B.; Clayton, S. M.; Crnkovic, J.; Debevec, P. T.; Hertzog, D. W.; Kammel, P.; Kiburg, B.; Kunkle, J.; McNabb, R.; Mulhauser, F.; Oezben, C. S.; Polly, C. C.; Webber, D. M.; Winter, P.; Banks, T. I.; Crowe, K. M.; Lauss, B.; Barnes, M. J.; Wait, G. D.; Battu, S.

    2007-07-20

    The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, {tau}{sub {mu}}=2.197 013(24) {mu}s, is in excellent agreement with the previous world average. The new world average {tau}{sub {mu}}=2.197 019(21) {mu}s determines the Fermi constant G{sub F}=1.166 371(6)x10{sup -5} GeV{sup -2} (5 ppm). Additionally, the precision measurement of the positive-muon lifetime is needed to determine the nucleon pseudoscalar coupling g{sub P}.

  8. Input/Output of ab-initio nuclear structure calculations for improved performance and portability

    SciTech Connect (OSTI)

    Laghave, Nikhil

    2010-01-01

    Many modern scientific applications rely on highly computation intensive calculations. However, most applications do not concentrate as much on the role that input/output operations can play for improved performance and portability. Parallelizing input/output operations of large files can significantly improve the performance of parallel applications where sequential I/O is a bottleneck. A proper choice of I/O library also offers a scope for making input/output operations portable across different architectures. Thus, use of parallel I/O libraries for organizing I/O of large data files offers great scope in improving performance and portability of applications. In particular, sequential I/O has been identified as a bottleneck for the highly scalable MFDn (Many Fermion Dynamics for nuclear structure) code performing ab-initio nuclear structure calculations. We develop interfaces and parallel I/O procedures to use a well-known parallel I/O library in MFDn. As a result, we gain efficient I/O of large datasets along with their portability and ease of use in the down-stream processing. Even situations where the amount of data to be written is not huge, proper use of input/output operations can boost the performance of scientific applications. Application checkpointing offers enormous performance improvement and flexibility by doing a negligible amount of I/O to disk. Checkpointing saves and resumes application state in such a manner that in most cases the application is unaware that there has been an interruption to its execution. This helps in saving large amount of work that has been previously done and continue application execution. This small amount of I/O provides substantial time saving by offering restart/resume capability to applications. The need for checkpointing in optimization code NEWUOA has been identified and checkpoint/restart capability has been implemented in NEWUOA by using simple file I/O.

  9. Determination of Structural Carbohydrates and Lignin in Biomass: Laboratory Analytical Procedure (LAP) (Revised July 2011)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Determination of Structural Carbohydrates and Lignin in Biomass Laboratory Analytical Procedure (LAP) Issue Date: April 2008 Revision Date: August 2012 (Version 08-03-2012) A. Sluiter, B. Hames, R. Ruiz, C. Scarlata, J. Sluiter, D. Templeton, and D. Crocker Technical Report NREL/TP-510-42618 Revised August 2012 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National

  10. System and method for forming synthetic protein crystals to determine the conformational structure by crystallography

    DOE Patents [OSTI]

    Craig, G.D.; Glass, R.; Rupp, B.

    1997-01-28

    A method is disclosed for forming synthetic crystals of proteins in a carrier fluid by use of the dipole moments of protein macromolecules that self-align in the Helmholtz layer adjacent to an electrode. The voltage gradients of such layers easily exceed 10{sup 6}V/m. The synthetic protein crystals are subjected to x-ray crystallography to determine the conformational structure of the protein involved. 2 figs.

  11. System and method for forming synthetic protein crystals to determine the conformational structure by crystallography

    DOE Patents [OSTI]

    Craig, George D.; Glass, Robert; Rupp, Bernhard

    1997-01-01

    A method for forming synthetic crystals of proteins in a carrier fluid by use of the dipole moments of protein macromolecules that self-align in the Helmholtz layer adjacent to an electrode. The voltage gradients of such layers easily exceed 10.sup.6 V/m. The synthetic protein crystals are subjected to x-ray crystallography to determine the conformational structure of the protein involved.

  12. SHELXT – Integrated space-group and crystal-structure determination

    SciTech Connect (OSTI)

    Sheldrick, George M.

    2015-01-01

    SHELXT automates routine small-molecule structure determination starting from single-crystal reflection data, the Laue group and a reasonable guess as to which elements might be present. The new computer program SHELXT employs a novel dual-space algorithm to solve the phase problem for single-crystal reflection data expanded to the space group P1. Missing data are taken into account and the resolution extended if necessary. All space groups in the specified Laue group are tested to find which are consistent with the P1 phases. After applying the resulting origin shifts and space-group symmetry, the solutions are subject to further dual-space recycling followed by a peak search and summation of the electron density around each peak. Elements are assigned to give the best fit to the integrated peak densities and if necessary additional elements are considered. An isotropic refinement is followed for non-centrosymmetric space groups by the calculation of a Flack parameter and, if appropriate, inversion of the structure. The structure is assembled to maximize its connectivity and centred optimally in the unit cell. SHELXT has already solved many thousand structures with a high success rate, and is optimized for multiprocessor computers. It is, however, unsuitable for severely disordered and twinned structures because it is based on the assumption that the structure consists of atoms.

  13. Determination of shape anisotropy in embedded low contrast submonolayer quantum dot structures

    SciTech Connect (OSTI)

    Dhomkar, S.; Ji, H.; Kuskovsky, I. L.; Vaxelaire, N.; Noyan, I. C.; Shuvayev, V.; Tamargo, M. C.

    2015-12-21

    We describe a procedure for the morphological characterization of hard-to-image submonolayer quantum dot structures. This procedure employs high resolution x-ray diffraction based reciprocal space mapping, accompanied by rigorous diffraction modeling for precise determination of the morphology of submonolayer quantum dots. Our modelling results and experimental data clearly show that the investigated quantum dots are anisotropically elongated along the [110] orientation. Complementary polarization dependent photoluminescence measurements, combined with our previously reported magneto-photoluminescence data, confirm this conclusion. Our formalism enables direct extraction of structural information of complex embedded three-dimensional structures, which, due to their low electron density contrast with respect to the surrounding host matrix, cannot be readily investigated by traditional electron diffraction techniques.

  14. X-ray structure determination using low-resolution electron microscopy maps for molecular replacement

    SciTech Connect (OSTI)

    Jackson, Ryan N.; McCoy, Airlie J.; Terwilliger, Thomas C.; Read, Randy J.; Wiedenheft, Blake

    2015-07-30

    Structures of multi-subunit macromolecular machines are primarily determined by either electron microscopy (EM) or X-ray crystallography. In many cases, a structure for a complex can be obtained at low resolution (at a coarse level of detail) with EM and at higher resolution (with finer detail) by X-ray crystallography. The integration of these two structural techniques is becoming increasingly important for generating atomic models of macromolecular complexes. A low-resolution EM image can be a powerful tool for obtaining the "phase" information that is missing from an X-ray crystallography experiment, however integration of EM and X-ray diffraction data has been technically challenging. Here we show a step-by-step protocol that explains how low-resolution EM maps can be placed in the crystallographic unit cell by molecular replacement, and how initial phases computed from the placed EM density are extended to high resolution by averaging maps over non-crystallographic symmetry. As the resolution gap between EM and Xray crystallography continues to narrow, the use of EM maps to help with X-ray crystal structure determination, as described in this protocol, will become increasingly effective.

  15. X-ray structure determination using low-resolution electron microscopy maps for molecular replacement

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jackson, Ryan N.; McCoy, Airlie J.; Terwilliger, Thomas C.; Read, Randy J.; Wiedenheft, Blake

    2015-07-30

    Structures of multi-subunit macromolecular machines are primarily determined by either electron microscopy (EM) or X-ray crystallography. In many cases, a structure for a complex can be obtained at low resolution (at a coarse level of detail) with EM and at higher resolution (with finer detail) by X-ray crystallography. The integration of these two structural techniques is becoming increasingly important for generating atomic models of macromolecular complexes. A low-resolution EM image can be a powerful tool for obtaining the "phase" information that is missing from an X-ray crystallography experiment, however integration of EM and X-ray diffraction data has been technically challenging.more » Here we show a step-by-step protocol that explains how low-resolution EM maps can be placed in the crystallographic unit cell by molecular replacement, and how initial phases computed from the placed EM density are extended to high resolution by averaging maps over non-crystallographic symmetry. As the resolution gap between EM and Xray crystallography continues to narrow, the use of EM maps to help with X-ray crystal structure determination, as described in this protocol, will become increasingly effective.« less

  16. Ab-initio structure determination of {beta}-La{sub 2}WO{sub 6}

    SciTech Connect (OSTI)

    Chambrier, M-H.; Kodjikian, S.; Ibberson, R.M.; Goutenoire, F.

    2009-02-15

    The structure of the low-temperature form of {beta}-La{sub 2}WO{sub 6} has been determined from laboratory X-ray, neutron time-of-flight and electron diffraction data. This tungstate crystallizes in the non-centrosymmetric orthorhombic space group (no. 19) P2{sub 1}2{sub 1}2{sub 1}, with Z=8, a=7.5196(1) A, b=10.3476(1) A, c=12.7944(2) A, and a measured density 7.37(1) g cm{sup -3}. The structure consists of tungsten [WO{sub 6}] octahedra and tetrahedral [OLa{sub 4}]. Tungsten polyhedra are connected such that [W{sub 2}O{sub 11}]{sup 10-} units are formed. - Graphical abstract: Projection of La{sub 2}WO{sub 6} structure along [100]. The structure could be described by [W{sub 2}O{sub 11}]{sup -10} structural unit formed by two corner-sharing octahedra.

  17. Improved determination of the atmospheric parameters of the pulsating sdB star Feige 48

    SciTech Connect (OSTI)

    Latour, M.; Fontaine, G.; Brassard, P.; Green, E. M.; Chayer, P.

    2014-06-10

    As part of a multifaceted effort to better exploit the asteroseismological potential of the pulsating sdB star Feige 48, we present an improved spectroscopic analysis of that star based on new grids of NLTE, fully line-blanketed model atmospheres. To that end, we gathered four high signal-to-noise ratio time-averaged optical spectra of varying spectral resolutions from 1.0 to 8.7 , and we made use of the results of four independent studies to fix the abundances of the most important metals in the atmosphere of Feige 48. The mean atmospheric parameters we obtained from our four spectra of Feige 48 are: T {sub eff} = 29,850 60 K, log g = 5.46 0.01, and log N(He)/N(H) = 2.88 0.02. We also modeled, for the first time, the He II line at 1640 from the STIS archive spectrum of the star, and with this line we found an effective temperature and a surface gravity that match well with the values obtained with the optical data. With some fine tuning of the abundances of the metals visible in the optical domain, we were able to achieve a very good agreement between our best available spectrum and our best-fitting synthetic one. Our derived atmospheric parameters for Feige 48 are in rather good agreement with previous estimates based on less sophisticated models. This underlines the relatively small effects of the NLTE approach combined with line blanketing in the atmosphere of this particular star, implying that the current estimates of the atmospheric parameters of Feige 48 are reliable and secure.

  18. The black hole binary V4641 Sagitarii: Activity in quiescence and improved mass determinations

    SciTech Connect (OSTI)

    MacDonald, Rachel K. D.; Bailyn, Charles D.; Buxton, Michelle; Cantrell, Andrew G.; Chatterjee, Ritaban; Kennedy-Shaffer, Ross; Orosz, Jerome A.; Markwardt, Craig B.; Swank, Jean H.

    2014-03-20

    We examine ?10 yr of photometric data and find that the black hole X-ray binary V4641 Sgr has two optical states, passive and active, during X-ray quiescence. The passive state is dominated by ellipsoidal variations and is stable in the shape and variability of the light curve. The active state is brighter and more variable. Emission during the active state varies over the course of the orbital period and is redder than the companion star. These optical/infrared states last for weeks or months. V4641 Sgr spends approximately 85% of X-ray quiescence in the passive state and 15% in the active. We analyze passive colors and spectroscopy of V4641 Sgr and show that they are consistent with a reddened B9III star (with E(B V) = 0.37 0.19) with little or no contribution from the accretion disk. We use X-ray observations with an updated ephemeris to place an upper limit on the duration of an X-ray eclipse of <8.3 in phase (?1.6 hr). High-resolution spectroscopy yields a greatly improved measurement of the rotational velocity of the companion star of V {sub rot}sin i = 100.9 0.8 km s{sup 1}. We fit ellipsoidal models to the passive state data and find an inclination angle of i = 72.3 4.1, a mass ratio of Q = 2.2 0.2, and component masses for the system of M {sub BH} = 6.4 0.6 M {sub ?} and M {sub 2} = 2.9 0.4 M {sub ?}. Using these values we calculate an updated distance to V4641 Sgr of 6.2 0.7 kpc.

  19. Introducing improved structural properties and salt dependence into a coarse-grained model of DNA

    SciTech Connect (OSTI)

    Snodin, Benedict E. K. Mosayebi, Majid; Schreck, John S.; Romano, Flavio; Doye, Jonathan P. K.; Randisi, Ferdinando; ulc, Petr; Ouldridge, Thomas E.; Tsukanov, Roman; Nir, Eyal; Louis, Ard A.

    2015-06-21

    We introduce an extended version of oxDNA, a coarse-grained model of deoxyribonucleic acid (DNA) designed to capture the thermodynamic, structural, and mechanical properties of single- and double-stranded DNA. By including explicit major and minor grooves and by slightly modifying the coaxial stacking and backbone-backbone interactions, we improve the ability of the model to treat large (kilobase-pair) structures, such as DNA origami, which are sensitive to these geometric features. Further, we extend the model, which was previously parameterised to just one salt concentration ([Na{sup +}] = 0.5M), so that it can be used for a range of salt concentrations including those corresponding to physiological conditions. Finally, we use new experimental data to parameterise the oxDNA potential so that consecutive adenine bases stack with a different strength to consecutive thymine bases, a feature which allows a more accurate treatment of systems where the flexibility of single-stranded regions is important. We illustrate the new possibilities opened up by the updated model, oxDNA2, by presenting results from simulations of the structure of large DNA objects and by using the model to investigate some salt-dependent properties of DNA.

  20. Site specific incorporation of heavy atom-containing unnatural amino acids into proteins for structure determination

    DOE Patents [OSTI]

    Xie, Jianming; Wang, Lei; Wu, Ning; Schultz, Peter G.

    2008-07-15

    Translation systems and other compositions including orthogonal aminoacyl tRNA-synthetases that preferentially charge an orthogonal tRNA with an iodinated or brominated amino acid are provided. Nucleic acids encoding such synthetases are also described, as are methods and kits for producing proteins including heavy atom-containing amino acids, e.g., brominated or iodinated amino acids. Methods of determining the structure of a protein, e.g., a protein into which a heavy atom has been site-specifically incorporated through use of an orthogonal tRNA/aminoacyl tRNA-synthetase pair, are also described.

  1. Structure of Csd3 from Helicobacter pylori, a cell shape-determining metallopeptidase

    SciTech Connect (OSTI)

    An, Doo Ri; Kim, Hyoun Sook; Kim, Jieun; Im, Ha Na; Yoon, Hye Jin; Yoon, Ji Young; Jang, Jun Young; Hesek, Dusan; Lee, Mijoon; Mobashery, Shahriar; Kim, Soon-Jong; Lee, Byung Il; Suh, Se Won

    2015-03-01

    H. pylori Csd3 (HP0506), together with other peptidoglycan hydrolases, plays an important role in determining cell shape. Its crystal structure in the latent state is reported. Helicobacter pylori is associated with various gastrointestinal diseases such as gastritis, ulcers and gastric cancer. Its colonization of the human gastric mucosa requires high motility, which depends on its helical cell shape. Seven cell shape-determining genes (csd1, csd2, csd3/hdpA, ccmA, csd4, csd5 and csd6) have been identified in H. pylori. Their proteins play key roles in determining the cell shape through modifications of the cell-wall peptidoglycan by the alteration of cross-linking or by the trimming of peptidoglycan muropeptides. Among them, Csd3 (also known as HdpA) is a bifunctional enzyme. Its d, d-endopeptidase activity cleaves the d-Ala{sup 4}-mDAP{sup 3} peptide bond between cross-linked muramyl tetrapeptides and pentapeptides. It is also a d, d-carboxypeptidase that cleaves off the terminal d-Ala{sup 5} from the muramyl pentapeptide. Here, the crystal structure of this protein has been determined, revealing the organization of its three domains in a latent and inactive state. The N-terminal domain 1 and the core of domain 2 share the same fold despite a very low level of sequence identity, and their surface-charge distributions are different. The C-terminal LytM domain contains the catalytic site with a Zn{sup 2+} ion, like the similar domains of other M23 metallopeptidases. Domain 1 occludes the active site of the LytM domain. The core of domain 2 is held against the LytM domain by the C-terminal tail region that protrudes from the LytM domain.

  2. Optimization of nanoparticle structure for improved conversion efficiency of dye solar cell

    SciTech Connect (OSTI)

    Mohamed, Norani Muti; Zaine, Siti Nur Azella

    2014-10-24

    Heavy dye loading and the ability to contain the light within the thin layer (typically ∼12 μm) are the requirement needed for the photoelectrode material in order to enhance the harvesting efficiency of dye solar cell. This can be realized by optimizing the particle size with desirable crystal structure. The paper reports the investigation on the dependency of the dye loading and light scattering on the properties of nanostructured photoelectrode materials by comparing 4 different samples of TiO{sub 2} in the form of nanoparticles and micron-sized TiO{sub 2} aggregates which composed of nanocrystallites. Their properties were evaluated by using scanning electron microscopy, X-ray diffraction and UVVis spectroscopy while the performance of the fabricated test cells were measured using universal photovoltaic test system (UPTS) under 1000 W/cm{sup 2} intensity of radiation. Nano sized particles provide large surface area which allow for greater dye adsorption but have no ability to retain the incident light in the TiO{sub 2} film. In contrast, micron-sized particles in the form of aggregates can generate light scattering allowing the travelling distance of the light to be extended and increasing the interaction between the photons and dye molecules adsorb on TiO{sub 2}nanocrystallites. This resulted in an improvement in the conversion efficiency of the aggregates that demonstrates the close relation between light scattering effect and the structure of the photolectrode film.

  3. DETERMINING THE NATURE OF THE EXTENDED H I STRUCTURE AROUND LITTLE THINGS DWARF GALAXY NGC 1569

    SciTech Connect (OSTI)

    Johnson, Megan

    2013-06-15

    This work presents an extended, neutral hydrogen emission map around Magellanic-type dwarf irregular galaxy (dIm) NGC 1569. In the spring of 2010, the Robert C. Byrd Green Bank Telescope was used to map a 9 Degree-Sign Multiplication-Sign 2 Degree-Sign region in H I line emission that includes NGC 1569 and IC 342 as well as two other dwarf galaxies. The primary objective for these observations was to search for structures potentially connecting NGC 1569 with IC 342 group members in order to trace previous interactions and thus, provide an explanation for the starburst and peculiar kinematics prevalent in NGC 1569. A large, half-degree diameter H I cloud was detected that shares the same position and velocity as NGC 1569. Also, two long structures were discovered that are reminiscent of intergalactic filaments extending out in a V-shaped manner from NGC 1569 toward UGCA 92, a nearby dwarf galaxy. These filamentary structures extend for about 1. Degree-Sign 5, which is 77 kpc at NGC 1569. There is a continuous velocity succession with the 0. Degree-Sign 5 H I cloud, filaments, and main body of the galaxy. The 0. Degree-Sign 5 H I cloud and filamentary structures may be foreground Milky Way, but are suggestive as possible remnants of an interaction between NGC 1569 and UGCA 92. The data also show two tidal tails extending from UGCA 86 and IC 342, respectively. These structures may be part of a continuous H I bridge but more data are needed to determine if this is the case.

  4. Structure determination of {alpha}-La{sub 6}W{sub 2}O{sub 15}

    SciTech Connect (OSTI)

    Chambrier, M-H.; Ibberson, R.M.; Goutenoire, F.

    2010-06-15

    The structure of the high temperature alpha form of La{sub 6}W{sub 2}O{sub 15} has been determined ab-initio from high temperature laboratory X-ray and neutron time-of-flight data. This tungstate crystallizes in the non-centrosymmetric orthorhombic space group (No. 20) C222{sub 1}, with Z=2, a=12.6250(2) A, b=9.1875(1) A, c=5.9688(1) A. The structure comprises [O{sub 2}La{sub 3}] infinite ribbons and is better described by the structural formula [O{sub 2}La{sub 3}]{sub 2}[WO{sub 5.5}]{sub 2}. Using this description we can understand the strong structural similarity of the present compound with compounds of the general composition BiM{sub 2}AO{sub 6} (M=Cu, Mg, Zn, Mn, Cd, Ca, Pb; A=P, As, V) described as [O{sub 2}M{sub 2}Bi][AO{sub 4}]. The [WO{sub 5.5}] entity implies oxygen disorder in the material. - Graphical abstract: Projection of the polyhedra around the tungsten atom. Atoms labelled in grey are occupied at 50%. Short oxygen-oxygen distances are marked. The polyhedra represents WO{sub 5.5} that is related to the structural unit W{sub 2}O{sub 11} unit. Alpha-La{sub 6}W{sub 2}O{sub 15} could be described as [O{sub 2}La{sub 3}]{sub 2}[WO{sub 5.5}]{sub 2}.

  5. Characterizing the Nano and Micro Structure of Concrete toImprove its Durability

    SciTech Connect (OSTI)

    Monteiro, P.J.M.; Kirchheim, A.P.; Chae, S.; Fischer, Peter; MacDowell, Alastair; Schaible, Eirc; Wenk, H.R.; Macdowell, Alastair A.

    2009-01-13

    New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images of ice inside cement paste and cracking caused by the alkali?silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools are shown on this paper.

  6. Characterizing the nano and micro structure of concrete to improve its durability

    SciTech Connect (OSTI)

    Monteiro, P.J.M.; Kirchheim, A.P.; Chae, S.; Fischer, P.; MacDowell, A.A.; Schaible, E.; Wenk, H.R.

    2008-10-22

    New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images on ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools will be shown on this paper.

  7. Comparison of algorithms for determination of rotation measure and Faraday structure. I. 1100–1400 MHz

    SciTech Connect (OSTI)

    Sun, X. H.; Akahori, Takuya; Anderson, C. S.; Farnes, J. S.; O’Sullivan, S. P.; Rudnick, L.; O’Brien, T.; Bell, M. R.; Bray, J. D.; Scaife, A. M. M.; Ideguchi, S.; Kumazaki, K.; Stepanov, R.; Stil, J.; Wolleben, M.; Takahashi, K.; Weeren, R. J. van E-mail: larry@umn.edu

    2015-02-01

    Faraday rotation measures (RMs) and more general Faraday structures are key parameters for studying cosmic magnetism and are also sensitive probes of faint ionized thermal gas. A definition of which derived quantities are required for various scientific studies is needed, as well as addressing the challenges in determining Faraday structures. A wide variety of algorithms has been proposed to reconstruct these structures. In preparation for the Polarization Sky Survey of the Universe's Magnetism (POSSUM) to be conducted with the Australian Square Kilometre Array Pathfinder and the ongoing Galactic Arecibo L-band Feeds Array Continuum Transit Survey (GALFACTS), we run a Faraday structure determination data challenge to benchmark the currently available algorithms, including Faraday synthesis (previously called RM synthesis in the literature), wavelet, compressive sampling, and QU-fitting. The input models include sources with one Faraday thin component, two Faraday thin components, and one Faraday thick component. The frequency set is similar to POSSUM/GALFACTS with a 300 MHz bandwidth from 1.1 to 1.4 GHz. We define three figures of merit motivated by the underlying science: (1) an average RM weighted by polarized intensity, RM{sub wtd}, (2) the separation Δϕ of two Faraday components, and (3) the reduced chi-squared χ{sub r}{sup 2}. Based on the current test data with a signal-to-noise ratio of about 32, we find the following. (1) When only one Faraday thin component is present, most methods perform as expected, with occasional failures where two components are incorrectly found. (2) For two Faraday thin components, QU-fitting routines perform the best, with errors close to the theoretical ones for RM{sub wtd} but with significantly higher errors for Δϕ. All other methods, including standard Faraday synthesis, frequently identify only one component when Δϕ is below or near the width of the Faraday point-spread function. (3) No methods as currently implemented

  8. Pathway structure determination in complex stochastic networks with non-exponential dwell times

    SciTech Connect (OSTI)

    Li, Xin; Kolomeisky, Anatoly B.; Valleriani, Angelo

    2014-05-14

    Analysis of complex networks has been widely used as a powerful tool for investigating various physical, chemical, and biological processes. To understand the emergent properties of these complex systems, one of the most basic issues is to determine the structure and topology of the underlying networks. Recently, a new theoretical approach based on first-passage analysis has been developed for investigating the relationship between structure and dynamic properties for network systems with exponential dwell time distributions. However, many real phenomena involve transitions with non-exponential waiting times. We extend the first-passage method to uncover the structure of distinct pathways in complex networks with non-exponential dwell time distributions. It is found that the analysis of early time dynamics provides explicit information on the length of the pathways associated to their dynamic properties. It reveals a universal relationship that we have condensed in one general equation, which relates the number of intermediate states on the shortest path to the early time behavior of the first-passage distributions. Our theoretical predictions are confirmed by extensive Monte Carlo simulations.

  9. Crushable structure performance determined from reconstructed dynamic forces during impact tests

    SciTech Connect (OSTI)

    Bateman, V.I.

    1995-01-01

    A force reconstruction technique has been used to assess the dynamic performance of a crushable structure (a bomb nose) in both the axial (90{degrees}) and slapdown (30{degrees}) impact conditions. The dynamic force characteristics for the nose design, determined from these test results, have been used to write a dynamic force specification for a new nose design that will replace the old nose. The dynamic forces are reconstructed from measured acceleration responses with the Sum of Weighted Accelerations Technique (SWAT) developed at Sandia National Laboratories. Axial characterizations for the old nose are presented from tests at two SNL facilities: a rocket rail launcher facility and an 18-Inch horizontal actuator facility. The characterizations for the old nose are compared to the characterizations for two new nose designs. Slapdown characterizations for the old nose are presented. Incorporation of the test results into a dynamic force specification is discussed.

  10. Crystallography Without Crystals: Determining the Structure of Individual Biological Molecules and Nanoparticles

    ScienceCinema (OSTI)

    Ourmazd, Abbas [University of Wisconsin, Milwaukee, Wisconsin, USA

    2010-01-08

    Ever shattered a valuable vase into 10 to the 6th power pieces and tried to reassemble it under a light providing a mean photon count of 10 minus 2 per detector pixel with shot noise? If you can do that, you can do single-molecule crystallography. This talk will outline how this can be done in principle. In more technical terms, the talk will describe how the combination of scattering physics and Bayesian algorithms can be used to reconstruct the 3-D diffracted intensity distribution from a collection of individual 2-D diffiraction patterns down to a mean photon count of 10 minus 2 per pixel, the signal level anticipated from the Linac Coherent Light Source, and hence determine the structure of individual macromolecules and nanoparticles.

  11. Phase 1. Screening guidelines to determine the structures exempt from Executive Order 12941

    SciTech Connect (OSTI)

    1995-09-01

    This report presents data regarding the guidelines for determining structures that are exempt from executive order 12941. Executive order 12941 was enacted to assure seismic safety of existing federally owned or leased buildings. This reports considered only the minimum amount of information. This information varied from building to building and from site to site. The scope of the guidelines is to cover all five DOE sites that fall under the DOE Oak Ridge Operations and are operated by LMES. These facilities are the ORNL, Y-12 Plant, K-25 Site all at Oak Ridge, Tennessee; the Paducah Gaseous Diffusion Plant, Paducah, Kentucky; and the Portsmouth Gaseous Diffusion Plant, Portsmouth, Ohio. Off site facilities, owned or leased, that are occupied by LMES are also included.

  12. 43-kilodalton protein of Torpedo nicotinic postsynaptic membranes: purification and determination of primary structure

    SciTech Connect (OSTI)

    Carr, C.; McCourt, D.; Cohen, J.B.

    1987-11-03

    The primary structure of the 43-kilodalton peripheral membrane protein (43-kDa protein) of Torpedo nicotinic postsynaptic membrane has been determined. The /sup 14/C-labelled 43-kDa protein, which was isolated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis, has an amino terminus resistant to Edman degradation, while the sequence at the carboxyl terminus is Tyr-Val. An amino acid sequence of 405 residues was obtained by NH/sub 2/-terminal sequence analysis of complementary peptides generated by digestion with trypsin, chymotrypsin, Staphylococcus aureus V8 protease, and endoproteinase Lys-C, as well as by chemical cleavage at methionine. This sequence of molecular mass 45,618 daltons lacks the amino terminus but extends to the carboxyl terminus of the 43-kDa protein. Unusual structural features of the 43-kDa protein include two regions of approx. 80 residues, each containing 10% cysteine, as well as stretches predicted to exist as amphipathic ..cap alpha..-helices. Other than the group blocking the amino terminus, no evidence was found for posttranslational modification of amino acids. The 43-kDa protein may represent a novel protein family because a computer search of this sequence with the National Biomedical Research Foundation data base (Release 12.0) did not reveal any significant homology to known protein sequences.

  13. Method of Determining the Extent to which a Nickel Structure has been Attached by a Fluorine-Containing Gas

    DOE Patents [OSTI]

    Brusie, James P.

    2004-07-13

    The method of determining the extent to which a nickel structure has been attacked by a halogen containing gas to which it has been exposed which comprises preparing a quantity of water substantially free from dissolved oxygen, passing ammonia gas through a cuprammonium solution to produce ammonia substantially free from oxygen, dissolving said oxygen-free ammonia in said water to produce a saturated aqueous ammonia solution free from uncombined oxygen, treating at least a portion of said nickel structure of predetermined weight with said solution to dissolve nickel compounds from the surface of said structure without dissolving an appreciable amount of said nickel and analyzing the resulting solution to determine the quantity of said nickel compounds that was associated with said said portion of said structure to determine the proportion of combined nickel in said nickel structure.

  14. Method of determining the extent to which a nickel structure has been attached by a fluorine-containing gas

    DOE Patents [OSTI]

    Brusie, James P.

    2004-07-13

    The method of determining the extent to which a nickel structure has been attacked by a halogen containing gas to which it has been exposed which comprises preparing a quantity of water substantially free from dissolved oxygen, passing ammonia gas through a cuprammonium solution to produce ammonia substantially free from oxygen, dissolving said oxygen-free ammonia in said water to produce a saturated aqueous ammonia solution free from uncombined oxygen, treating at least a portion of said nickel structure of predetermined weight with said solution to dissolve nickel compounds from the surface of said structure without dissolving an appreciable amount of said nickel and analyzing the resulting solution to determine the quantity of said nickel compounds that was associated with said said portion of said structure to determine the proportion of combined nickel in said nickel structure.

  15. Structural Testing at the NWTC Helps Improve Blade Design and Increase System Reliability; NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    2015-08-01

    Since 1990, the National Renewable Energy Laboratory’s (NREL's) National Wind Technology Center (NWTC) has tested more than 150 wind turbine blades. NWTC researchers can test full-scale and subcomponent articles, conduct data analyses, and provide engineering expertise on best design practices. Structural testing of wind turbine blades enables designers, manufacturers, and owners to validate designs and assess structural performance to specific load conditions. Rigorous structural testing can reveal design and manufacturing problems at an early stage of development that can lead to overall improvements in design and increase system reliability.

  16. Synthesis and Structure Determination of Ferromagnetic Semiconductors LaAMnSnO6 (A = Sr Ba)

    SciTech Connect (OSTI)

    T Yang; T Perkisas; J Hadermann; M Croft; A Ignatov; M Greenblatt

    2011-12-31

    LaAMnSnO{sub 6} (A = Sr, Ba) have been synthesized by high temperature solid-state reactions under dynamic 1% H{sub 2}/Ar flow. Rietveld refinements on room temperature powder X-ray diffraction data indicate that LaSrMnSnO{sub 6} crystallizes in the GdFeO{sub 3}-structure, with space group Pnma and, combined with transmission electron microscopy, LaBaMnSnO{sub 6} in Imma. Both space groups are common in disordered double-perovskites. The Mn{sup 3+} and Sn{sup 4+} ions whose valence states were confirmed by X-ray absorption spectroscopy, are completely disordered over the B-sites and the BO{sub 6} octahedra are slightly distorted. LaAMnSnO{sub 6} are ferromagnetic semiconductors with a T{sub C} = 83 K for the Sr- and 66 K for the Ba-compound. The title compounds, together with the previously reported LaCaMnSnO{sub 6} provide an interesting example of progression from Pnma to Imma as the tolerance factor increases. An analysis of the relationship between space group and tolerance factor for the series LaAMnMO{sub 6} (A = Ca, Sr, Ba; M = Sn, Ru) provides a better understanding of the symmetry determination for double perovskites.

  17. Determining heavy metals in spent compact fluorescent lamps (CFLs) and their waste management challenges: Some strategies for improving current conditions

    SciTech Connect (OSTI)

    Taghipour, Hassan; Amjad, Zahra; Jafarabadi, Mohamad Asghari; Gholampour, Akbar; Norouz, Prviz

    2014-07-15

    Highlights: • Heavy metals in spent compact fluorescent lamps (CFLs) determined. • Current waste management condition of CFLs in Iran assessed. • Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. • We propose extended producer responsibility (EPR) for CFLs waste management. - Abstract: From environmental viewpoint, the most important advantage of compact fluorescent lamps (CFLs) is reduction of green house gas emissions. But their significant disadvantage is disposal of spent lamps because of containing a few milligrams of toxic metals, especially mercury and lead. For a successful implementation of any waste management plan, availability of sufficient and accurate information on quantities and compositions of the generated waste and current management conditions is a fundamental prerequisite. In this study, CFLs were selected among 20 different brands in Iran. Content of heavy metals including mercury, lead, nickel, arsenic and chromium was determined by inductive coupled plasma (ICP). Two cities, Tehran and Tabriz, were selected for assessing the current waste management condition of CFLs. The study found that waste generation amount of CFLs in the country was about 159.80, 183.82 and 153.75 million per year in 2010, 2011 and 2012, respectively. Waste generation rate of CFLs in Iran was determined to be 2.05 per person in 2012. The average amount of mercury, lead, nickel, arsenic and chromium was 0.417, 2.33, 0.064, 0.056 and 0.012 mg per lamp, respectively. Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. For improving the current conditions, we propose by considering the successful experience of extended producer responsibility (EPR) in other electronic waste management. The EPR program with advanced recycling fee (ARF) is implemented for collecting and then recycling CFLs. For encouraging consumers to take the spent CFLs back at the end of the products’ useful life, a proportion of

  18. Nanoscale structure in AgSbTe2 determined by diffuse elastic neutron scattering

    SciTech Connect (OSTI)

    Specht, Eliot D [ORNL; Ma, Jie [ORNL; Delaire, Olivier A [ORNL; Budai, John D [ORNL; May, Andrew F [ORNL; Karapetrova, Evguenia A. [Argonne National Laboratory (ANL)

    2015-01-01

    Diffuse elastic neutron scattering measurements confirm that AgSbTe2 has a hierarchical structure, with defects on length scales from nanometers to microns. While scattering from mesoscale structure is consistent with previously-proposed structures in which Ag and Sb order on a NaCl lattice, more diffuse scattering from nanoscale structure suggests a structural rearrangement in which hexagonal layers form a combination of (ABC), (ABA), and (AAB) stacking sequences. The AgCrSe2 structure is the best-fitting model for the local atomic arrangements.

  19. TOWARD AN IMPROVED UNDERSTANDING OF STRUCTURE AND MAGNETISM IN NEPTUNIUM AND PLUTONIUM PHOSPHONATES AND SULFONATES

    SciTech Connect (OSTI)

    Albrecht-Schmitt, Thomas

    2012-03-01

    This grant supported the exploratory synthesis of new actinide materials with all of the actinides from thorium to californium with the exceptions of protactinium and berkelium. We developed detailed structure-property relationships that allowed for the identification of novel materials with selective ion-exchange, selective oxidation, and long-range magnetic ordering. We found novel bonding motifs and identified periodic trends across the actinide series. We identified structural building units that would lead to desired structural features and novel topologies. We also characterized many different spectroscopic trends across the actinide series. The grant support the preparation of approximately 1200 new compounds all of which were structurally characterized.

  20. Method of determining whether radioactive contaminants are inside or outside a structure

    DOE Patents [OSTI]

    Lattin, Kenneth R.

    1977-01-01

    A measure is obtained of the relative quantities of radioactive material inside and outside a structure such as a pipe by obtaining two spectra of gamma radiation on a dummy structure of the same shape and composition. A first spectrum is obtained with a quantity of the radioactive element to be measured located inside the structure and a second spectrum is obtained with a quantity of the same contaminant located outside the structure. The two spectra are normalized to the same equivalent value in a portion of the spectrum that does not reflect the presence of gamma rays resulting from Compton scattering in the structure. Comparison of that portion of the spectra obtained where Compton scattering is a factor gives a measure of the relative amounts of contaminants inside and outside the structure on a spectrum obtained from a test structure. The invention may also be practiced by obtaining a plurality of spectra at varying known concentrations inside and outside the dummy structure.

  1. Performance improvements of symmetry-breaking reflector structures in nonimaging devices

    DOE Patents [OSTI]

    Winston, Roland

    2004-01-13

    A structure and method for providing a broken symmetry reflector structure for a solar concentrator device. The component of the optical direction vector along the symmetry axis is conserved for all rays propagated through a translationally symmetric optical device. This quantity, referred to as the translational skew invariant, is conserved in rotationally symmetric optical systems. Performance limits for translationally symmetric nonimaging optical devices are derived from the distributions of the translational skew invariant for the optical source and for the target to which flux is to be transferred. A numerically optimized non-tracking solar concentrator utilizing symmetry-breaking reflector structures can overcome the performance limits associated with translational symmetry.

  2. Determination of reactive oxygen species from ZnO micro-nano structures with shape-dependent photocatalytic activity

    SciTech Connect (OSTI)

    He, Weiwei; Zhao, Hongxiao; Jia, Huimin; Yin, Jun-Jie; Zheng, Zhi

    2014-05-01

    Graphical abstract: ZnO micro/nano structures with shape dependent photocatalytic activity were prepared by hydrothermal reaction. The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were identified precisely by electron spin resonance spectroscopy. The type of reactive oxygen species was determined by band gap structure of ZnO. - Highlights: ZnO micro/nano structures with different morphologies were prepared by solvothermal reaction. Multi-pod like ZnO structures exhibited superior photocatalytic activity. The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were characterized precisely by electron spin resonance spectroscopy. The type of reactive oxygen species was determined by band gap structure of ZnO. - Abstract: ZnO micro/nano structures with different morphologies have been prepared by the changing solvents used during their synthesis by solvothermal reaction. Three typical shapes of ZnO structures including hexagonal, bell bottom like and multi-pod formed and were characterized by scanning electron microscopy and X-ray diffraction. Multi pod like ZnO structures exhibited the highest photocatalytic activity toward degradation of methyl orange. Using electron spin resonance spectroscopy coupled with spin trapping techniques, we demonstrate an effective way to identify precisely the generation of hydroxyl radicals, superoxide and singlet oxygen from the irradiated ZnO multi pod structures. The type of reactive oxygen species formed was predictable from the band gap structure of ZnO. These results indicate that the shape of micro-nano structures significantly affects the photocatalytic activity of ZnO, and demonstrate the value of electron spin resonance spectroscopy for characterizing the type of reactive oxygen species formed during photoexcitation of semiconductors.

  3. A Top-Down Approach to Determining Global RNA Structures in Solution...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Related Information: RNA 3D Structure Analysis and Prediction Publisher: 2012; Springer;NA;N. Leontis, E. Westhof;335-359 Research Org: Advanced Photon Source ...

  4. Apparatus and method for determining microscale interactions based on compressive sensors such as crystal structures

    DOE Patents [OSTI]

    McAdams, Harley; AlQuraishi, Mohammed

    2015-04-21

    Techniques for determining values for a metric of microscale interactions include determining a mesoscale metric for a plurality of mesoscale interaction types, wherein a value of the mesoscale metric for each mesoscale interaction type is based on a corresponding function of values of the microscale metric for the plurality of the microscale interaction types. A plurality of observations that indicate the values of the mesoscale metric are determined for the plurality of mesoscale interaction types. Values of the microscale metric are determined for the plurality of microscale interaction types based on the plurality of observations and the corresponding functions and compressed sensing.

  5. Using support vector machines to improve elemental ion identification in macromolecular crystal structures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Morshed, Nader; Echols, Nathaniel; Adams, Paul D.

    2015-04-25

    In the process of macromolecular model building, crystallographers must examine electron density for isolated atoms and differentiate sites containing structured solvent molecules from those containing elemental ions. This task requires specific knowledge of metal-binding chemistry and scattering properties and is prone to error. A method has previously been described to identify ions based on manually chosen criteria for a number of elements. Here, the use of support vector machines (SVMs) to automatically classify isolated atoms as either solvent or one of various ions is described. Two data sets of protein crystal structures, one containing manually curated structures deposited with anomalousmore » diffraction data and another with automatically filtered, high-resolution structures, were constructed. On the manually curated data set, an SVM classifier was able to distinguish calcium from manganese, zinc, iron and nickel, as well as all five of these ions from water molecules, with a high degree of accuracy. Additionally, SVMs trained on the automatically curated set of high-resolution structures were able to successfully classify most common elemental ions in an independent validation test set. This method is readily extensible to other elemental ions and can also be used in conjunction with previous methods based on a priori expectations of the chemical environment and X-ray scattering.« less

  6. Using support vector machines to improve elemental ion identification in macromolecular crystal structures

    SciTech Connect (OSTI)

    Morshed, Nader; Echols, Nathaniel; Adams, Paul D.

    2015-04-25

    In the process of macromolecular model building, crystallographers must examine electron density for isolated atoms and differentiate sites containing structured solvent molecules from those containing elemental ions. This task requires specific knowledge of metal-binding chemistry and scattering properties and is prone to error. A method has previously been described to identify ions based on manually chosen criteria for a number of elements. Here, the use of support vector machines (SVMs) to automatically classify isolated atoms as either solvent or one of various ions is described. Two data sets of protein crystal structures, one containing manually curated structures deposited with anomalous diffraction data and another with automatically filtered, high-resolution structures, were constructed. On the manually curated data set, an SVM classifier was able to distinguish calcium from manganese, zinc, iron and nickel, as well as all five of these ions from water molecules, with a high degree of accuracy. Additionally, SVMs trained on the automatically curated set of high-resolution structures were able to successfully classify most common elemental ions in an independent validation test set. This method is readily extensible to other elemental ions and can also be used in conjunction with previous methods based on a priori expectations of the chemical environment and X-ray scattering.

  7. Determination of the crystalline structure of scale solids from the 16H evaporator gravity drain line to tank 38H

    SciTech Connect (OSTI)

    Oji, L. N.

    2015-10-01

    August 2015, scale solids from the 16H Evaporator Gravity Drain Line (GDL) to the Tank 38H were delivered to SRNL for analysis. The desired analytical goal was to identify and confirm the crystalline structure of the scale material and determine if the form of the aluminosilicate mineral was consistent with previous analysis of the scale material from the GDL.

  8. Improved self-absorption correction for extended x-ray absorption fine-structure measurements

    SciTech Connect (OSTI)

    Booth, C.H.; Bridges, F.

    2003-06-04

    Extended x-ray absorption fine-structure (EXAFS) data collected in the fluorescence mode are susceptible to an apparent amplitude reduction due to the self-absorption of the fluorescing photon by the sample before it reaches a detector. Previous treatments have made the simplifying assumption that the effect of the EXAFS on the correction term is negligible, and that the samples are in the thick limit. We present a nearly exact treatment that can be applied for any sample thickness or concentration, and retains the EXAFS oscillations in the correction term.

  9. Determination of the structure of the X(3872) in anti pA collisions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Larionov, A. B.; Strikman, M.; Bleicher, M.

    2015-07-22

    The structure of the X(3872) meson is unknown. Different competing models of the cc exotic state X(3872) exist, including the possibilities that this state is either a mesonic molecule with dominating D0D*0 + c.c. composition, a ccqq tetraquark, or a cc-gluon hybrid state. It is expected that the X(3872) state is rather strongly coupled to the pp channel and, therefore, can be produced in pp and pA collisions at PANDA. We propose to test the hypothetical molecular structure of X(3872) by studying the D or D* source stripping reactions on a nuclear residue.

  10. Improving electronic structure methods to predict nano-optoelectronics and nano-catalyst functions.

    SciTech Connect (OSTI)

    Nielsen, Ida Marie B.; Marzari, Nicola; Shelnutt, John Allen; Kulik, Heather J.; Medforth, Craig John; Leung, Kevin

    2009-10-01

    This report focuses on quantum chemistry and ab initio molecular dynamics (AIMD) calculations applied to elucidate the mechanism of the multi-step, 2-electron, electrochemical reduction of the green house gas molecule carbon dioxide (CO{sub 2}) to carbon monoxide (CO) in aqueous media. When combined with H{sub 2} gas to form synthesis ('syn') gas, CO becomes a key precursor to methane, methanol, and other useful hydrocarbon products. To elucidate the mechanism of this reaction, we apply computational electrochemistry which is a fledgling, important area of basic science critical to energy storage. This report highlights several approaches, including the calculation of redox potentials, the explicit depiction of liquid water environments using AIMD, and free energy methods. While costly, these pioneering calculations reveal the key role of hydration- and protonation-stabilization of reaction intermediates, and may inform the design of CO{sub 2}-capture materials as well as its electrochemical reduction. In the course of this work, we have also dealt with the challenges of identifying and applying electronic structure methods which are sufficiently accurate to deal with transition metal ion complex-based catalyst. Such electronic structure methods are also pertinent to the accurate modeling of actinide materials and therefore to nuclear energy research. Our multi-pronged effort towards achieving this titular goal of the LDRD is discussed.

  11. Device and nondestructive method to determine subsurface micro-structure in dense materials

    DOE Patents [OSTI]

    Sun, Jiangang

    2006-05-09

    A method and a device to detect subsurface three-dimensional micro-structure in a sample by illuminating the sample with light of a given polarization and detecting light emanating from the sample that has a different direction of polarization by means of a confocal optical system.

  12. Using computerized tomography to determine ionospheric structures. Part 1, Notivation and basic approaches

    SciTech Connect (OSTI)

    Vittitoe, C.N.

    1993-08-01

    Properties of the ionosphere are reviewed along with its correlations with other geophysical phenomena and with applications of ionospheric studies to communication, navigation, and surveillance systems. Computer tomography is identified as a method to determine the detailed, three-dimensional distribution of electron density within the ionosphere. Several tomography methods are described, with a basic approach illustrated by an example. Limitations are identified.

  13. Structure of the Archaeoglobus fulgidus orphan ORF AF1382 determined by sulfur SAD from a moderately diffracting crystal

    SciTech Connect (OSTI)

    Zhu, Jin-Yi; Fu, Zheng-Qing; Chen, Lirong; Xu, Hao; Chrzas, John; Rose, John Wang, Bi-Cheng

    2012-09-01

    The crystal structure of the 11.14 kDa orphan ORF 1382 from Archaeoglobus fulgidus (AF1382) has been determined by sulfur SAD phasing using data collected from a moderately diffracting crystal and 1.9 synchrotron X-rays. The crystal structure of the 11.14 kDa orphan ORF 1382 from Archaeoglobus fulgidus (AF1382) has been determined by sulfur SAD phasing using a moderately diffracting crystal and 1.9 wavelength synchrotron X-rays. AF1382 was selected as a structural genomics target by the Southeast Collaboratory for Structural Genomics (SECSG) since sequence analyses showed that it did not belong to the Pfam-A database and thus could represent a novel fold. The structure was determined by exploiting longer wavelength X-rays and data redundancy to increase the anomalous signal in the data. AF1382 is a 95-residue protein containing five S atoms associated with four methionine residues and a single cysteine residue that yields a calculated Bijvoet ratio (?F{sub anom}/F) of 1.39% for 1.9 wavelength X-rays. Coupled with an average Bijvoet redundancy of 25 (two 360 data sets), this produced an excellent electron-density map that allowed 69 of the 95 residues to be automatically fitted. The S-SAD model was then manually completed and refined (R = 23.2%, R{sub free} = 26.8%) to 2.3 resolution. High-resolution data were subsequently collected from a better diffracting crystal using 0.97 wavelength synchrotron X-rays and the S-SAD model was refined (R = 17.9%, R{sub free} = 21.4%) to 1.85 resolution. AF1382 has a winged-helixturnhelix structure common to many DNA-binding proteins and most closely resembles the N-terminal domain (residues 182) of the Rio2 kinase from A. fulgidus, which has been shown to bind DNA, and a number of MarR-family transcriptional regulators, suggesting a similar DNA-binding function for AF1382. The analysis also points out the advantage gained from carrying out data reduction and structure determination on-site while the crystal is

  14. Improved resolution of hydrocarbon structures and constitutional isomers in complex mixtures using Gas Chromatography-Vacuum Ultraviolet-Mass Spectrometry (GC-VUV-MS)

    SciTech Connect (OSTI)

    Aerosol Dynamics Inc; Aerodyne Research, Inc.,; Tofwerk AG, Thun; Isaacman, Gabriel; Wilson, Kevin R.; Chan, Arthur W. H.; Worton, David R.; Kimmel, Joel R.; Nah, Theodora; Hohaus, Thorsten; Gonin, Marc; Kroll, Jesse H.; Worsnop, Doug R.; Goldstein, Allen H.

    2011-09-13

    Understanding the composition of complex hydrocarbon mixtures is important for environmental studies in a variety of fields, but many prevalent compounds cannot be confidently identified using traditional gas chromatography-mass spectrometry (GC-MS) techniques. This work uses vacuum-ultraviolet (VUV) ionization to elucidate the structures of a traditionally"unresolved complex mixture" by separating components by GC retention time, tR, and mass-to-charge ratio, m/Q, which are used to determine carbon number, NC, and the number of rings and double bonds, NDBE. Constitutional isomers are resolved based on tR, enabling the most complete quantitative analysis to date of structural isomers in an environmentally-relevant hydrocarbon mixture. Unknown compounds are classified in this work by carbon number, degree of saturation, presence of rings, and degree of branching, providing structural constraints. The capabilities of this analysis are explored using diesel fuel, in which constitutional isomer distribution patterns are shown to be reproducible between carbon numbers and follow predictable rules. Nearly half of the aliphatic hydrocarbon mass is shown to be branched, suggesting branching is more important in diesel fuel than previously shown. The classification of unknown hydrocarbons and the resolution of constitutional isomers significantly improves resolution capabilities for any complex hydrocarbon mixture.

  15. Determination of the structure of the X(3872) in p¯A collisions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Larionov, A. B.; Strikman, M.; Bleicher, M.

    2015-07-22

    The structure of the X(3872) meson is unknown. Different competing models of the cc¯ exotic state X(3872) exist, including the possibilities that this state is either a mesonic molecule with dominating D0D¯*0 + c.c. composition, a cc¯qq¯ tetraquark, or a cc¯-gluon hybrid state. It is expected that the X(3872) state is rather strongly coupled to the pp¯ channel and, therefore, can be produced in pp¯ and p¯A collisions at PANDA. We propose to test the hypothetical molecular structure of X(3872) by studying the D or D¯* source stripping reactions on a nuclear residue.

  16. Pore-structure determinations of silica aerogels by {sup 129}Xe NMR spectroscopy and imaging.

    SciTech Connect (OSTI)

    Gregory, D. M.; Gerald, R. E., II; Botto, R. E.; Chemistry

    1998-04-01

    Silica aerogels represent a new class of open-pore materials with pore dimensions on a scale of tens of nanometers, and are thus classified as mesoporous materials. In this work, we show that the combination of NMR spectroscopy and chemical-shift selective magnetic resonance imaging (MRI) can resolve some of the important aspects of the structure of silica aerogels. The use of xenon as a gaseous probe in combination with spatially resolved NMR techniques is demonstrated to be a powerful, new approach for characterizing the average pore structure and steady-state spatial distributions of xenon atoms in different physicochemical environments. Furthermore, dynamic NMR magnetization transfer experiments and pulsed-field gradient (PFG) measurements have been used to characterize exchange processes and diffusive motion of xenon in samples at equilibrium. In particular, this new NMR approach offers unique information and insights into the nanoscopic pore structure and microscopic morphology of aerogels and the dynamical behavior of occluded adsorbates. MRI provides spatially resolved information on the nature of the flaw regions found in these materials. Pseudo-first-order rate constants for magnetization transfer among the bulk and occluded xenon phases indicate xenon-exchange rate constants on the order of 1 s-1 for specimens having volumes of 0.03 cm3. PFG diffusion measurements show evidence of anisotropic diffusion for xenon occluded within aerogels, with nominal self-diffusivity coefficients on the order of D= 10-3cm2/s.

  17. Structure symmetry determination and magnetic evolution in Sr2Ir1–xRhxO4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ye, Feng; Wang, Xiaoping; Hoffmann, Christina; Wang, Jinchen; Chi, Songxue; Matsuda, Masaaki; Chakoumakos, Bryan C.; Fernandez-Baca, Jaime A.; Cao, Gang

    2015-11-23

    We use single-crystal neutron diffraction to determine the crystal structure symmetry and to study the magnetic evolution in the rhodium doped iridates Sr2Ir1–xRhxO4 (0 ≤ x ≤ 0.16). Throughout this doping range, the crystal structure retains a tetragonal symmetry (space group I41/a) with two distinct magnetic Ir sites in the unit cell forming staggered IrO6 rotation. Upon Rh doping, the magnetic order is suppressed and the magnetic moment of Ir4+ is reduced from 0.21 μB/Ir for x = 0 to 0.18 μB/Ir for x = 0.12. As a result, the magnetic structure at x = 0.12 is different from thatmore » of the parent compound while the moments remain in the basal plane.« less

  18. Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wong-Ng, W.; Culp, J. T.; Chen, Y. S.; Zavalij, P.; Espinal, L.; Siderius, D. W.; Allen, A. J.; Scheins, S.; Matranga, C.

    2013-01-01

    This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN)4], (L = 1,2-bis(4-pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P21/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, β = 96.141(2)°, V = 2767.4(4) Å3, Z = 4, Dc = 1.46 g cm-1. Ni(bpene)[Ni(CN)4] assumes a pillared layer structure with layers defined by Ni[Ni(CN)4]n nets and bpene ligands acting as pillars. With the present crystallization technique which involves the use of concentrated ammonium hydroxide solution andmore » dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN)4](1/2)bpene∙DMSO2H2O, or Ni2N7C24H25SO3. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline material with a significantly improved CO2 uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO2 uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO2 per unit cell was obtained.« less

  19. Low Resolution Structure and Dynamics of a Colicin-Receptor Complex Determined by Neutron Scattering

    SciTech Connect (OSTI)

    Clifton, Luke A; Johnson, Christopher L; Solovyova, Alexandra; Callow, Phil; Weiss, Kevin L; Ridley, Helen; Le Brun, Anton P; Kinane, Christian; Webster, John; Holt, Stephen A; Lakey, Jeremy H

    2012-01-01

    Proteins that translocate across cell membranes need to overcome a significant hydrophobic barrier. This is usually accomplished via specialized protein complexes, which provide a polar transmembrane pore. Exceptions to this include bacterial toxins, which insert into and cross the lipid bilayer itself. We are studying the mechanism by which large antibacterial proteins enter Escherichia coli via specific outer membrane proteins. Here we describe the use of neutron scattering to investigate the interaction of colicin N with its outer membrane receptor protein OmpF. The positions of lipids, colicin N, and OmpF were separately resolved within complex structures by the use of selective deuteration. Neutron reflectivity showed, in real time, that OmpF mediates the insertion of colicin N into lipid monolayers. This data were complemented by Brewster Angle Microscopy images, which showed a lateral association of OmpF in the presence of colicin N. Small angle neutron scattering experiments then defined the three-dimensional structure of the colicin N-OmpF complex. This revealed that colicin N unfolds and binds to the OmpF-lipid interface. The implications of this unfolding step for colicin translocation across membranes are discussed.

  20. Fault zone structure determined through the analysis of earthquake arrival times

    SciTech Connect (OSTI)

    Michelini, A.

    1991-10-01

    This thesis develops and applies a technique for the simultaneous determination of P and S wave velocity models and hypocenters from a set of arrival times. The velocity models are parameterized in terms of cubic B-splines basis functions which permit the retrieval of smooth models that can be used directly for generation of synthetic seismograms using the ray method. In addition, this type of smoothing limits the rise of instabilities related to the poor resolving power of the data. V{sub P}/V{sub S} ratios calculated from P and S models display generally instabilities related to the different ray-coverages of compressional and shear waves. However, V{sub P}/V{sub S} ratios are important for correct identification of rock types and this study introduces a new methodology based on adding some coupling (i.e., proportionality) between P and S models which stabilizes the V{sub P}/V{sub S} models around some average preset value determined from the data. Tests of the technique with synthetic data show that this additional coupling regularizes effectively the resulting models.

  1. Systems and methods for determining strength of cylindrical structures by internal pressure loading

    DOE Patents [OSTI]

    DeTeresa, Steven John; Groves, Scott Eric; Sanchez, Roberto Joseph; Andrade, William Andrew

    2015-08-04

    In one embodiment, an apparatus, includes: a mandrel; an expansion cylinder, comprising: opposite first and second ends; an inner circumferential surface extending between the ends and characterized by an inner diameter, the inner circumferential surface defining a hollow cavity; an outer circumferential surface extending between the ends and characterized by an outer diameter that is greater than the inner diameter; and a plurality of slots extending from the inner circumferential surface to the outer circumferential surface and latitudinally oriented between the ends; and one or more base plates configured to engage one of the ends of the expansion cylinder. In another embodiment, a method includes: arranging an expansion cylinder inside a test cylinder; arranging a mandrel inside the expansion cylinder; applying a force to the mandrel for exerting a radial force on the expansion cylinder; and detecting one or more indicia of structural failure of the test cylinder.

  2. Advances in the structure and microstructure determination of yttrium silicates using the Rietveld method

    SciTech Connect (OSTI)

    Cannas, Carla; Musinu, Anna; Piccaluga, Giorgio; Deidda, Claudio; Serra, Filomena; Bazzoni, Marco; Enzo, Stefano . E-mail: enzo@uniss.it

    2005-05-15

    The Y{sub 2}O{sub 3}-SiO{sub 2} 1:1 composition doped with a weak concentration of europium ions was prepared with the sol-gel technique and the products studied by X-ray diffraction as a function of temperature in the range from 900 to 1300 deg. C, using the method of Rietveld for quantitative evaluation of amorphous and crystalline evolving phases. The amorphous profile of the yttrium oxyorthosilicate glasses has been described following the 'Rietveld for Disordered Materials' method and subsequently included in the patterns of semicrystalline samples that have been heat-treated for temperatures above 900 deg. C at 1000, 1100, 1150, 1200 and 1300 deg. C. The quantitative evaluation of the amorphous phase is obtainable from the Rietveld approach equivalent to the method after Ruland. This enabled us to study in fine detail the structural rearrangements and growth mechanisms that take place during the crystal-to-amorphous transformation in terms of coordination numbers, average interatomic distances, average crystallite size and microstrain and to identify the polymorphous transformation involving the Y{sub 2}SiO{sub 5} phase from low-to-high-temperature forms, as well as some minor quantities of other phases namely {alpha}-Y{sub 2}Si{sub 2}O{sub 7} phase, Y{sub 2}O{sub 3} and Y{sub 4.67}(SiO{sub 4}){sub 3}O.

  3. The Molecular Structure of a Phosphatidylserine Bilayer Determined by Scattering and Molecular Dynamics Simulations

    SciTech Connect (OSTI)

    Pan, Jianjun [University of South Florida, Tampa (USF)] [University of South Florida, Tampa (USF); Cheng, Xiaolin [ORNL] [ORNL; Monticelli, Luca [Institut National de la Sant et de la Recherche Mdicale (INSERM) and INTS, France] [Institut National de la Sant et de la Recherche Mdicale (INSERM) and INTS, France; Heberle, Frederick A [ORNL] [ORNL; Kucerka, Norbert [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,] [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,; Tieleman, D. Peter [University of Calgary, ALberta, Canada] [University of Calgary, ALberta, Canada; Katsaras, John [ORNL] [ORNL

    2014-01-01

    Phosphatidylserine (PS) lipids play essential roles in biological processes, including enzyme activation and apoptosis. We report on the molecular structure and atomic scale interactions of a fluid bilayer composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (POPS). A scattering density profile model, aided by molecular dynamics (MD) simulations, was developed to jointly refine different contrast small-angle neutron and X-ray scattering data, which yielded a lipid area of 62.7 A2 at 25 C. MD simulations with POPS lipid area constrained at different values were also performed using all-atom and aliphatic united-atom models. The optimal simulated bilayer was obtained using a model-free comparison approach. Examination of the simulated bilayer, which agrees best with the experimental scattering data, reveals a preferential interaction between Na+ ions and the terminal serine and phosphate moieties. Long-range inter-lipid interactions were identified, primarily between the positively charged ammonium, and the negatively charged carboxylic and phosphate oxygens. The area compressibility modulus KA of the POPS bilayer was derived by quantifying lipid area as a function of surface tension from area-constrained MD simulations. It was found that POPS bilayers possess a much larger KA than that of neutral phosphatidylcholine lipid bilayers. We propose that the unique molecular features of POPS bilayers may play an important role in certain physiological functions.

  4. Surface structure determinations of crystalline ionic thin films grown on transition metal single crystal surfaces by low energy electron diffraction

    SciTech Connect (OSTI)

    Roberts, J.G.

    2000-05-01

    The surface structures of NaCl(100), LiF(100) and alpha-MgCl2(0001) adsorbed on various metal single crystals have been determined by low energy electron diffraction (LEED). Thin films of these salts were grown on metal substrates by exposing the heated metal surface to a molecular flux of salt emitted from a Knudsen cell. This method of investigating thin films of insulators (ionic salts) on a conducting substrate (metal) circumvents surface charging problems that plagued bulk studies, thereby allowing the use of electron-based techniques to characterize the surface.

  5. WHAT DETERMINES THE DENSITY STRUCTURE OF MOLECULAR CLOUDS? A CASE STUDY OF ORION B WITH HERSCHEL

    SciTech Connect (OSTI)

    Schneider, N.; Andre, Ph.; Koenyves, V.; Motte, F.; Arzoumanian, D.; Didelon, P.; Hennemann, M.; Hill, T.; Palmeirim, P.; Peretto, N.; Roy, A.; Ward-Thompson, D.; Benedettini, M.; Pezzuto, S.; Rygl, K. L. J.; Bressert, E.; Di Francesco, J.; Griffin, M.; and others

    2013-04-01

    A key parameter to the description of all star formation processes is the density structure of the gas. In this Letter, we make use of probability distribution functions (PDFs) of Herschel column density maps of Orion B, Aquila, and Polaris, obtained with the Herschel Gould Belt survey (HGBS). We aim to understand which physical processes influence the PDF shape, and with which signatures. The PDFs of Orion B (Aquila) show a lognormal distribution for low column densities until A{sub V} {approx} 3 (6), and a power-law tail for high column densities, consistent with a {rho}{proportional_to}r {sup -2} profile for the equivalent spherical density distribution. The PDF of Orion B is broadened by external compression due to the nearby OB stellar aggregates. The PDF of a quiescent subregion of the non-star-forming Polaris cloud is nearly lognormal, indicating that supersonic turbulence governs the density distribution. But we also observe a deviation from the lognormal shape at A{sub V} > 1 for a subregion in Polaris that includes a prominent filament. We conclude that (1) the point where the PDF deviates from the lognormal form does not trace a universal A{sub V} -threshold for star formation, (2) statistical density fluctuations, intermittency, and magnetic fields can cause excess from the lognormal PDF at an early cloud formation stage, (3) core formation and/or global collapse of filaments and a non-isothermal gas distribution lead to a power-law tail, and (4) external compression broadens the column density PDF, consistent with numerical simulations.

  6. Structure of modified [epsilon]-polylysine micelles and their application in improving cellular antioxidant activity of curcuminoids

    SciTech Connect (OSTI)

    Yu, Hailong; Li, Ji; Shi, Ke; Huang, Qingrong

    2015-10-15

    The micelle structure of octenyl succinic anhydride modified {var_epsilon}-polylysine (M-EPL), an anti-microbial surfactant prepared from natural peptide {var_epsilon}-polylysine in aqueous solution has been studied using synchrotron small-angle X-ray scattering (SAXS). Our results revealed that M-EPLs formed spherical micelles with individual size of 24-26 {angstrom} in aqueous solution which could further aggregate to form a larger dimension with averaged radius of 268-308 {angstrom}. Furthermore, M-EPL micelle was able to encapsulate curcuminoids, a group of poorly-soluble bioactive compounds from turmeric with poor oral bioavailability, and improve their water solubility. Three loading methods, including solvent evaporation, dialysis, and high-speed homogenization were compared. The results indicated that the dialysis method generated the highest loading capacity and curcuminoids water solubility. The micelle encapsulation was confirmed as there were no free curcuminoid crystals detected in the differential scanning calorimetry analysis. It was also demonstrated that M-EPL encapsulation stabilized curcuminoids against hydrolysis at pH 7.4 and the encapsulated curcuminoids showed elevated cellular antioxidant activity compared with free curcuminoids. This work suggested that M-EPL could be used as new biopolymer micelles for delivering poorly soluble drugs/phytochemicals and improving their bioactivities.

  7. Improved Pharmacological and Structural Properties of HIV Fusion Inhibitor AP3 over Enfuvirtide: Highlighting Advantages of Artificial Peptide Strategy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhu, Xiaojie; Zhu, Yun; Ye, Sheng; Wang, Qian; Xu, Wei; Su, Shan; Sun, Zhiwu; Yu, Fei; Liu, Qi; Wang, Chao; et al

    2015-08-19

    Enfuvirtide (T20), is the first HIV fusion inhibitor approved for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, its clinical application is limited because of short half-life, drug resistance and cross-reactivity with the preexisting antibodies in HIV-infected patients. Using an artificial peptide strategy, we designed a peptide with non-native protein sequence, AP3, which exhibited potent antiviral activity against a broad spectrum of HIV-1 strains, including those resistant to T20, and had remarkably longer in vivo half-life than T20. While the preexisting antibodies in HIV-infected patients significantly suppressed T20’s antiviral activity, these antibodies neither recognizedmore » AP3, nor attenuated its anti-HIV-1 activity. Structurally different from T20, AP3 could fold into single-helix and interact with gp41 NHR. The two residues, Met and Thr, at the N-terminus of AP3 form a hook-like structure to stabilize interaction between AP3 and NHR helices. Therefore, AP3 has potential for further development as a new HIV fusion inhibitor with improved antiviral efficacy, resistance profile and pharmacological properties over enfuvirtide. Meanwhile, this study highlighted the advantages of artificially designed peptides, and confirmed that this strategy could be used in developing artificial peptide-based viral fusion inhibitors against HIV and other enveloped viruses.« less

  8. Structural properties and band offset determination of p-channel mixed As/Sb type-II staggered gap tunnel field-effect transistor structure

    SciTech Connect (OSTI)

    Zhu, Y.; Jain, N.; Hudait, M. K.; Mohata, D. K.; Datta, S.; Lubyshev, D.; Fastenau, J. M.; Liu, A. K.

    2012-09-10

    The structural properties and band offset determination of p-channel staggered gap In{sub 0.7}Ga{sub 0.3}As/GaAs{sub 0.35}Sb{sub 0.65} heterostructure tunnel field-effect transistor (TFET) grown by molecular beam epitaxy (MBE) were investigated. High resolution x-ray diffraction revealed that the active layers are strained with respect to 'virtual substrate.' Dynamic secondary ion mass spectrometry confirmed an abrupt junction profile at the In{sub 0.7}Ga{sub 0.3}As/GaAs{sub 0.35}Sb{sub 0.65} heterointerface and minimal level of intermixing between As and Sb atoms. The valence band offset of 0.37 {+-} 0.05 eV was extracted from x-ray photoelectron spectroscopy. A staggered band lineup was confirmed at the heterointerface with an effective tunneling barrier height of 0.13 eV. Thus, MBE-grown staggered gap In{sub 0.7}Ga{sub 0.3}As/GaAs{sub 0.35}Sb{sub 0.65} TFET structures are a promising p-channel option to provide critical guidance for the future design of mixed As/Sb type-II based complementary logic and low power devices.

  9. Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4

    SciTech Connect (OSTI)

    Wong-Ng, W.; Culp, J. T.; Chen, Y. S.; Zavalij, P.; Espinal, L.; Siderius, D. W.; Allen, A. J.; Scheins, S.; Matranga, C.

    2013-01-01

    This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN)4], (L = 1,2-bis(4-pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P21/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, β = 96.141(2)°, V = 2767.4(4) Å3, Z = 4, Dc = 1.46 g cm-1. Ni(bpene)[Ni(CN)4] assumes a pillared layer structure with layers defined by Ni[Ni(CN)4]n nets and bpene ligands acting as pillars. With the present crystallization technique which involves the use of concentrated ammonium hydroxide solution and dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN)4](1/2)bpene∙DMSO2H2O, or Ni2N7C24H25SO3. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline material with a significantly improved CO2 uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO2 uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO2 per unit cell was obtained.

  10. IMPROVED V I log(gf) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

    SciTech Connect (OSTI)

    Lawler, J. E.; Wood, M. P.; Den Hartog, E. A.; Feigenson, T.; Sneden, C.; Cowan, J. J. E-mail: mpwood@wisc.edu E-mail: tfeigenson@wisc.edu E-mail: cowan@nhn.ou.edu

    2015-01-01

    New emission branching fraction measurements for 836 lines of the first spectrum of vanadium (V I) are determined from hollow cathode lamp spectra recorded with the National Solar Observatory 1 m Fourier transform spectrometer (FTS) and a high-resolution echelle spectrometer. The branching fractions are combined with recently published radiative lifetimes from laser-induced fluorescence measurements to determine accurate absolute atomic transition probabilities for the 836 lines. The FTS data are also used to extract new hyperfine structure A coefficients for 26 levels of neutral vanadium. These new laboratory data are applied to determine the V abundance in the Sun and metal-poor star HD 84937, yielding log ε(V) = 3.956 ± 0.004 (σ = 0.037) based on 93 V I lines and log ε(V) = 1.89 ± 0.03 (σ = 0.07) based on nine V I lines, respectively, using the Holweger-Müller 1D model. These new V I abundance values for the Sun and HD 84937 agree well with our earlier determinations based upon V II.

  11. Determination of Hydrogen Bond Structure in Water versus Aprotic Environments To Test the Relationship Between Length and Stability

    SciTech Connect (OSTI)

    Sigala, Paul A.; Ruben, Eliza A.; Liu, Corey W.; Piccoli, Paula M. B.; Hohenstein, Edward G.; Martinez, Todd J.; Schultz, Arthur J.; Herschiag, Daniel

    2015-05-06

    Hydrogen bonds profoundly influence the architecture and activity of biological macromolecules. Deep appreciation of hydrogen bond contributions to biomolecular function thus requires a detailed understanding of hydrogen bond structure and energetics and the relationship between these properties. Hydrogen bond formation energies (Delta G(f)) are enormously more favorable in aprotic solvents than in water, and two classes of contributing factors have been proposed to explain this energetic difference, focusing respectively on the isolated and hydrogen-bonded species: (I) water stabilizes the dissociated donor and acceptor groups much better than aprotic solvents, thereby reducing the driving force for hydrogen bond formation; and (II) water lengthens hydrogen bonds compared to aprotic environments, thereby decreasing the potential energy within the hydrogen bond. Each model has been proposed to provide a dominant contribution to Delta G(f), but incisive tests that distinguish the importance of these contributions are lacking. Here we directly test the structural basis of model II. Neutron crystallography, NMR spectroscopy, and quantum mechanical calculations demonstrate that O-H center dot center dot center dot O hydrogen bonds in crystals, chloroform, acetone, and water have nearly identical lengths and very similar potential energy surfaces despite Delta G(f) differences >8 kcal/mol across these solvents. These results rule out a substantial contribution from solvent-dependent differences in hydrogen bond structure and potential energy after association (model II) and thus support the conclusion that differences in hydrogen bond Delta G(f) are predominantly determined by solvent interactions with the dissociated groups (model I). These findings advance our understanding of universal hydrogen-bonding interactions and have important implications for biology and engineering.

  12. Experimental phasing for structure determination using membrane-protein crystals grown by the lipid cubic phase method

    SciTech Connect (OSTI)

    Li, Dianfan; Pye, Valerie E.; Caffrey, Martin

    2015-01-01

    Very little information is available in the literature concerning the experimental heavy-atom phasing of membrane-protein structures where the crystals have been grown using the lipid cubic phase (in meso) method. In this paper, pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine labelling as applied to an integral membrane kinase crystallized in meso are described. An assay to assess cysteine accessibility for mercury labelling of membrane proteins is introduced. Despite the marked increase in the number of membrane-protein structures solved using crystals grown by the lipid cubic phase or in meso method, only ten have been determined by SAD/MAD. This is likely to be a consequence of the technical difficulties associated with handling proteins and crystals in the sticky and viscous hosting mesophase that is usually incubated in glass sandwich plates for the purposes of crystallization. Here, a four-year campaign aimed at phasing the in meso structure of the integral membrane diacylglycerol kinase (DgkA) from Escherichia coli is reported. Heavy-atom labelling of this small hydrophobic enzyme was attempted by pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine incorporation. Strategies and techniques for special handling are reported, as well as the typical results and the lessons learned for each of these approaches. In addition, an assay to assess the accessibility of cysteine residues in membrane proteins for mercury labelling is introduced. The various techniques and strategies described will provide a valuable reference for future experimental phasing of membrane proteins where crystals are grown by the lipid cubic phase method.

  13. One-photon mass-analyzed threshold ionization (MATI) spectroscopy of pyridine: Determination of accurate ionization energy and cationic structure

    SciTech Connect (OSTI)

    Lee, Yu Ran; Kang, Do Won; Kim, Hong Lae E-mail: hlkim@kangwon.ac.kr; Kwon, Chan Ho E-mail: hlkim@kangwon.ac.kr

    2014-11-07

    Ionization energies and cationic structures of pyridine were intensively investigated utilizing one-photon mass-analyzed threshold ionization (MATI) spectroscopy with vacuum ultraviolet radiation generated by four-wave difference frequency mixing in Kr. The present one-photon high-resolution MATI spectrum of pyridine demonstrated a much finer and richer vibrational structure than that of the previously reported two-photon MATI spectrum. From the MATI spectrum and photoionization efficiency curve, the accurate ionization energy of the ionic ground state of pyridine was confidently determined to be 73 570 ± 6 cm{sup −1} (9.1215 ± 0.0007 eV). The observed spectrum was almost completely assigned by utilizing Franck-Condon factors and vibrational frequencies calculated through adjustments of the geometrical parameters of cationic pyridine at the B3LYP/cc-pVTZ level. A unique feature unveiled through rigorous analysis was the prominent progression of the 10 vibrational mode, which corresponds to in-plane ring bending, and the combination of other totally symmetric fundamentals with the ring bending overtones, which contribute to the geometrical change upon ionization. Notably, the remaining peaks originate from the upper electronic state ({sup 2}A{sub 2}), as predicted by high-resolution photoelectron spectroscopy studies and symmetry-adapted cluster configuration interaction calculations. Based on the quantitatively good agreement between the experimental and calculated results, it was concluded that upon ionization the pyridine cation in the ground electronic state should have a planar structure of C{sub 2v} symmetry through the C-N axis.

  14. Continuous mutual improvement of macromolecular structure models in the PDB and of X-ray crystallographic software: The dual role of deposited experimental data

    SciTech Connect (OSTI)

    Terwilliger, Thomas C.; Bricogne, Gerard

    2014-09-30

    Accurate crystal structures of macromolecules are of high importance in the biological and biomedical fields. Models of crystal structures in the Protein Data Bank (PDB) are in general of very high quality as deposited. However, methods for obtaining the best model of a macromolecular structure from a given set of experimental X-ray data continue to progress at a rapid pace, making it possible to improve most PDB entries after their deposition by re-analyzing the original deposited data with more recent software. This possibility represents a very significant departure from the situation that prevailed when the PDB was created, when it was envisioned as a cumulative repository of static contents. A radical paradigm shift for the PDB is therefore proposed, away from the static archive model towards a much more dynamic body of continuously improving results in symbiosis with continuously improving methods and software. These simultaneous improvements in methods and final results are made possible by the current deposition of processed crystallographic data (structure-factor amplitudes) and will be supported further by the deposition of raw data (diffraction images). It is argued that it is both desirable and feasible to carry out small-scale and large-scale efforts to make this paradigm shift a reality. Small-scale efforts would focus on optimizing structures that are of interest to specific investigators. Large-scale efforts would undertake a systematic re-optimization of all of the structures in the PDB, or alternatively the redetermination of groups of structures that are either related to or focused on specific questions. All of the resulting structures should be made generally available, along with the precursor entries, with various views of the structures being made available depending on the types of questions that users are interested in answering.

  15. Continuous mutual improvement of macromolecular structure models in the PDB and of X-ray crystallographic software: The dual role of deposited experimental data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Terwilliger, Thomas C.; Bricogne, Gerard

    2014-09-30

    Accurate crystal structures of macromolecules are of high importance in the biological and biomedical fields. Models of crystal structures in the Protein Data Bank (PDB) are in general of very high quality as deposited. However, methods for obtaining the best model of a macromolecular structure from a given set of experimental X-ray data continue to progress at a rapid pace, making it possible to improve most PDB entries after their deposition by re-analyzing the original deposited data with more recent software. This possibility represents a very significant departure from the situation that prevailed when the PDB was created, when itmore » was envisioned as a cumulative repository of static contents. A radical paradigm shift for the PDB is therefore proposed, away from the static archive model towards a much more dynamic body of continuously improving results in symbiosis with continuously improving methods and software. These simultaneous improvements in methods and final results are made possible by the current deposition of processed crystallographic data (structure-factor amplitudes) and will be supported further by the deposition of raw data (diffraction images). It is argued that it is both desirable and feasible to carry out small-scale and large-scale efforts to make this paradigm shift a reality. Small-scale efforts would focus on optimizing structures that are of interest to specific investigators. Large-scale efforts would undertake a systematic re-optimization of all of the structures in the PDB, or alternatively the redetermination of groups of structures that are either related to or focused on specific questions. All of the resulting structures should be made generally available, along with the precursor entries, with various views of the structures being made available depending on the types of questions that users are interested in answering.« less

  16. IMPROVED Ni I log(gf) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

    SciTech Connect (OSTI)

    Wood, M. P.; Lawler, J. E.; Sneden, C.; Cowan, J. J. E-mail: jelawler@wisc.edu E-mail: cowan@nhn.ou.edu

    2014-04-01

    Atomic transition probability measurements for 371 Ni I lines in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform spectrometer and a new echelle spectrograph are combined with published radiative lifetimes to determine these transition probabilities. Generally good agreement is found in comparisons to previously reported Ni I transition probability measurements. Use of the new echelle spectrograph, independent radiometric calibration methods, and independent data analysis routines enable a reduction of systematic errors and overall improvement in transition probability uncertainty over previous measurements. The new Ni I data are applied to high-resolution visible and UV spectra of the Sun and metal-poor star HD 84937 to derive new, more accurate Ni abundances. Lines covering a wide range of wavelength and excitation potential are used to search for non-LTE effects.

  17. Recent Progress in the Structure Determination of GPCRs, a Membrane Protein Family with High Potential as Pharmaceutical Targets

    SciTech Connect (OSTI)

    Cherezov, Vadim; Abola, Enrique; Stevens, Raymond C.

    2015-11-30

    G protein-coupled receptors (GPCRs) constitute a highly diverse and ubiquitous family of integral membrane proteins, transmitting signals inside the cells in response to an assortment of disparate extra-cellular stimuli. Their strategic location on the cell surface and their involvement in crucial cellular and physiological processes turn these receptors into highly important pharmaceutical targets. Recent technological developments aimed at stabilization and crystallization of these receptors have led to significant breakthroughs in GPCR structure determination efforts. One of the successful approaches involved receptor stabilization with the help of a fusion partner combined with crystallization in lipidic cubic phase (LCP). The success of using an LCP matrix for crystallization is generally attributed to the creation of a more native, membrane-like stabilizing environment for GPCRs just prior to nucleation and to the formation of type I crystal lattices, thus generating highly ordered and strongly diffracting crystals. Here they describe protocols for reconstituting purified GPCRs in LCP, performing pre-crystallization assays, setting up crystallization trials in manual mode, detecting crystallization hits, optimizing crystallization conditions, harvesting, and collecting crystallographic data. The protocols provide a sensible framework for approaching crystallization of stabilized GPCRs in LCP, however, as in any crystallization experiment, extensive screening and optimization of crystallization conditions as well as optimization of protein construct and purification steps are required. The process remains risky and these protocols do not necessarily guarantee success.

  18. Method to improve commercial bonded SOI material

    DOE Patents [OSTI]

    Maris, Humphrey John; Sadana, Devendra Kumar

    2000-07-11

    A method of improving the bonding characteristics of a previously bonded silicon on insulator (SOI) structure is provided. The improvement in the bonding characteristics is achieved in the present invention by, optionally, forming an oxide cap layer on the silicon surface of the bonded SOI structure and then annealing either the uncapped or oxide capped structure in a slightly oxidizing ambient at temperatures greater than 1200.degree. C. Also provided herein is a method for detecting the bonding characteristics of previously bonded SOI structures. According to this aspect of the present invention, a pico-second laser pulse technique is employed to determine the bonding imperfections of previously bonded SOI structures.

  19. IMPROVED Ti II log(gf) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

    SciTech Connect (OSTI)

    Wood, M. P.; Lawler, J. E.; Sneden, C.; Cowan, J. J. E-mail: jelawler@wisc.edu E-mail: cowan@nhn.ou.edu

    2013-10-01

    Atomic transition probability measurements for 364 lines of Ti II in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform spectrometer (FTS) and a new echelle spectrometer are combined with published radiative lifetimes to determine these transition probabilities. The new results are in generally good agreement with previously reported FTS measurements. Use of the new echelle spectrometer, independent radiometric calibration methods, and independent data analysis routines enables a reduction of systematic errors and overall improvement in transition probability accuracy over previous measurements. The new Ti II data are applied to high-resolution visible and UV spectra of the Sun and metal-poor star HD 84937 to derive new, more accurate Ti abundances. Lines covering a range of wavelength and excitation potential are used to search for non-LTE effects. The Ti abundances derived using Ti II for these two stars match those derived using Ti I and support the relative Ti/Fe abundance ratio versus metallicity seen in previous studies.

  20. Mechanisms Determining the Structure of Gold-Catalyzed GaAs Nanowires Studied by in Situ X-ray Diffraction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Takahasi, Masamitu; Kozu, Miwa; Sasaki, Takuo; Hu, Wen

    2015-09-02

    The evolution of polytypism during GaAs nanowire growth was investigated with in situ X-ray diffraction. The growth of nanowires was found to start with the formation of zincblende structure, followed by the growth of wurtzite structure. The growth process was well reproduced by a simulation based on a layer-by-layer nucleation model. The good agreement between the measured and simulated results confirms that nucleation costs higher energy for the stackings changing the crystal structure than for those conserving the preceding structure. The transition in prevalent structure can be accounted for by the change of local growth conditions related to the shapemore » of triple phase line rather than by the change in supersaturation level, which quickly reaches steady state after starting growth.« less

  1. Mechanisms Determining the Structure of Gold-Catalyzed GaAs Nanowires Studied by in Situ X-ray Diffraction

    SciTech Connect (OSTI)

    Takahasi, Masamitu; Kozu, Miwa; Sasaki, Takuo; Hu, Wen

    2015-09-02

    The evolution of polytypism during GaAs nanowire growth was investigated with in situ X-ray diffraction. The growth of nanowires was found to start with the formation of zincblende structure, followed by the growth of wurtzite structure. The growth process was well reproduced by a simulation based on a layer-by-layer nucleation model. The good agreement between the measured and simulated results confirms that nucleation costs higher energy for the stackings changing the crystal structure than for those conserving the preceding structure. The transition in prevalent structure can be accounted for by the change of local growth conditions related to the shape of triple phase line rather than by the change in supersaturation level, which quickly reaches steady state after starting growth.

  2. Improvements to the DOE low-level waste regulatory structure and process under recommendation 94-2 - progress to date

    SciTech Connect (OSTI)

    Regnier, E.

    1995-12-31

    Among the concerns expressed by the Defense Nuclear Facility Safety Board (DNFSB) in its Recommendation 94-2 was the lack of a clearly defined and effective internal Department of Energy (DOE) regulatory oversight and enforcement process for ensuring that low-level radioactive waste management health, safety, and environmental requirements are met. Therefore, part of the response to the DNFSB concern is a task to clarify and strengthen the low-level waste management regulatory structure. This task is being conducted in two steps. First, consistent with the requirements of the current DOE waste management order and within the framework of the current organizational structure, interim clarification of a review process and the associated organizational responsibilities has been issued. Second, in coordination with the revision of the waste management order and consistent with the organizational responsibilities resulting from the strategic alignment of DOE, a rigorous, more independent regulatory oversight structure will be developed.

  3. MO-G-18C-07: Improving T2 Determination and Quantification of Lipid Methylene Protons in Proton Magnetic Resonance Spectroscopy at 3 T

    SciTech Connect (OSTI)

    Breitkreutz, D.; Fallone, B. G.; Yahya, A.

    2014-06-15

    Purpose: To improve proton magnetic resonance spectroscopy (MRS) transverse relaxation (T{sub 2}) determination and quantification of lipid methylene chain (1.3 ppm) protons by rewinding their J-coupling evolution. Methods: MRS experiments were performed on four lipid phantoms, namely, almond, corn, sunflower and oleic acid, using a 3 T Philips MRI scanner with a transmit/receive birdcage head coil. Two PRESS (Point RESolved Spectroscopy) pulse sequences were used. The first PRESS sequence employed standard bandwidth (BW) (?550 Hz) RF (radiofrequency) refocussing pulses, while the second used refocussing pulses of narrow BW (?50 Hz) designed to rewind J-coupling evolution of the methylene protons in the voxel of interest. Signal was acquired with each sequence from a 555 mm{sup 3} voxel, with a repetition time (TR) of 3000 ms, and with echo times (TE) of 100 to 200 ms in steps of 20 ms. 2048 sample points were measured with a 2000 Hz sampling bandwidth. Additionally, 30 mm outer volume suppression slabs were used to suppress signal outside the voxel of interest. The frequency of the RF pulses was set to that of the methylene resonance. Methylene peak areas were calculated and fitted in MATLAB to a monexponentially decaying function of the form M{sub 0}exp(-TE/T{sub 2}), where M{sub 0} is the extrapolated area when TE = 0 ms and yields a measure of concentration. Results: The determined values of M{sub 0} and T{sub 2} increased for all fatty acids when using the PRESS sequence with narrow BW refocussing pulses. M{sub 0} and T{sub 2} values increased by an average amount (over all the phantoms) of 31% and 14%, respectively. Conclusion: This investigation has demonstrated that J-coupling interactions of lipid methylene protons causes non-negligible signal losses which, if not accounted for, Result in underestimations of their levels and T{sub 2} values when performing MRS measurements. Funded by the Natural Sciences and Engineering Research Council of Canada and the

  4. Local Structure of La1-xSrxCoO3 determined from EXAFS and neutron PDF studies

    SciTech Connect (OSTI)

    Sundaram, N.; Jiang, Y.; Anderson, I. E.; Belanger, D. P.; Booth, C. H.; Bridges, F.; Mitchell, J. F.; Proffen, Th.; Zheng, H.

    2009-01-26

    The combined local structure techniques, extended x-ray absorption fine structure (EXAFS) and neutron pair distribution function analysis, have been used for temperatures 4<= T<= 330 K to rule out a large Jahn-Teller (JT) distortion of the Co-O bond in La1?xSrxCoO3 for a significant fraction of Co sites (x<= 0.35), indicating few, if any, JT-active, singly occupied eg Co sites exist.

  5. Single-particle structure determination by correlations of snapshot X-ray diffraction patterns (CXIDB ID 20)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Starodub, D.

    2013-03-25

    This deposition includes the diffraction images generated by the paired polystyrene spheres in random orientations. These images were used to determine and phase the single particle diffraction volume from their autocorrelation functions.

  6. Azine bridged silver coordination polymers: Powder X-ray diffraction route to crystal structure determination of silver benzotriazole

    SciTech Connect (OSTI)

    Rajeswaran, Manju . E-mail: manju.rajeswaran@kodak.com; Blanton, Thomas N.; Giesen, David J.; Whitcomb, David R.; Zumbulyadis, Nicholas; Antalek, Brian J.; Neumann, Marcus M.; Misture, Scott T.

    2006-04-15

    In continuation of our interest in solid-state structures of silver complexes of photographic importance, the structure for silver benzotriazole (AgBZT), has now been obtained. The preferred method for solving crystal structures is via single-crystal X-ray diffraction (XRD). However, for some materials, growing single crystals of appropriate size and quality is often difficult or even impossible. AgBZT is an example of such a silver complex with poor solubility. The usual routes to preparing single crystals using recrystallization from a cooperating solvent resulted in polycrystalline powder samples. We propose a crystal structure for AgBZT, solved from synchrotron X-ray powder diffraction data, using a direct-space Monte Carlo simulated annealing approach. AgBZT crystals are monoclinic (P2{sub 1} /c), with unit cell dimensions, a=14.8052(3) A, b=3.7498(4) A, c=12.3495(12) A, and {beta}=114.200(6){sup o}. The AgBZT complex is constructed from all three of the Benzotriazole (BZT) nitrogens bonding to a separate silver atom. As a consequence of this bonding mode, the structure is a highly cross-linked, coordination polymer.

  7. Using computerized tomography to determine ionospheric structures. Part 2, A method using curved paths to increase vertical resolution

    SciTech Connect (OSTI)

    Vittitoe, C.N.

    1993-08-01

    A method is presented to unfold the two-dimensional vertical structure in electron density by using data on the total electron content for a series of paths through the ionosphere. The method uses a set of orthonormal basis functions to represent the vertical structure and takes advantage of curved paths and the eikonical equation to reduce the number of iterations required for a solution. Curved paths allow a more thorough probing of the ionosphere with a given set of transmitter and receiver positions. The approach can be directly extended to more complex geometries.

  8. Improved estimates of separation distances to prevent unacceptable damage to nuclear power plant structures from hydrogen detonation for gaseous hydrogen storage. Technical report

    SciTech Connect (OSTI)

    Not Available

    1994-05-01

    This report provides new estimates of separation distances for nuclear power plant gaseous hydrogen storage facilities. Unacceptable damage to plant structures from hydrogen detonations will be prevented by having hydrogen storage facilities meet separation distance criteria recommended in this report. The revised standoff distances are based on improved calculations on hydrogen gas cloud detonations and structural analysis of reinforced concrete structures. Also, the results presented in this study do not depend upon equivalencing a hydrogen detonation to an equivalent TNT detonation. The static and stagnation pressures, wave velocity, and the shock wave impulse delivered to wall surfaces were computed for several different size hydrogen explosions. Separation distance equations were developed and were used to compute the minimum separation distance for six different wall cases and for seven detonating volumes (from 1.59 to 79.67 lbm of hydrogen). These improved calculation results were compared to previous calculations. The ratio between the separation distance predicted in this report versus that predicted for hydrogen detonation in previous calculations varies from 0 to approximately 4. Thus, the separation distances results from the previous calculations can be either overconservative or unconservative depending upon the set of hydrogen detonation parameters that are used. Consequently, it is concluded that the hydrogen-to-TNT detonation equivalency utilized in previous calculations should no longer be used.

  9. Minimal Determinants for Binding Activated G alpha from the Structure of a G alpha i1-Peptide Dimer

    SciTech Connect (OSTI)

    Johnston,C.; Lobanova, E.; Shavkunov, A.; Low, J.; Ramer, J.; Blasesius, R.; Fredericks, Z.; willard, F.; Kuhlman, B.; et al.

    2006-01-01

    G-Proteins cycle between an inactive GDP-bound state and an active GTP-bound state, serving as molecular switches that coordinate cellular signaling. We recently used phage display to identify a series of peptides that bind G{alpha}subunits in a nucleotide-dependent manner [Johnston, C. A., Willard, F. S., Jezyk, M. R., Fredericks, Z., Bodor, E. T., Jones, M. B., Blaesius, R., Watts, V. J., Harden, T. K., Sondek, J., Ramer, J. K., and Siderovski, D. P. (2005) Structure 13, 1069-1080]. Here we describe the structural features and functions of KB-1753, a peptide that binds selectively to GDP{center_dot}AlF{sub 4{sup -}}- and GTP{gamma}S-bound states of G{alpha}{sup i} subunits. KB-1753 blocks interaction of G{alpha}{sub transducin} with its effector, cGMP phosphodiesterase, and inhibits transducin-mediated activation of cGMP degradation. Additionally, KB-1753 interferes with RGS protein binding and resultant GAP activity. A fluorescent KB-1753 variant was found to act as a sensor for activated G{alpha} in vitro. The crystal structure of KB-1753 bound to G{alpha}{sub i1}-GDP{center_dot}AlF{sub 4{sup -}} reveals binding to a conserved hydrophobic groove between switch II and 3 helices and, along with supporting biochemical data and previous structural analyses, supports the notion that this is the site of effector interactions for G{alpha}i subunits.

  10. Synthesis, Structure Determination, and Hydrogen Sorption Studies of New Metal-Organic Frameworks Using Triazole and Naphthalenedicarboxylic Acid

    SciTech Connect (OSTI)

    Park,H.; Britten, J.; Mueller, U.; Lee, J.; Li, J.; Parise, J.

    2007-01-01

    Two new metal-organic framework compounds were synthesized under solvothermal conditions using Zn{sup 2+} ion, 1,2,4-triazole (TRZ), and 1,4- and 2,6-naphthalenedicarboxylic acids (NDC): Zn{sub 4}(TRZ){sub 4}(1,4-NDC){sub 2}-2DMF-2H{sub 2}O (1) and Zn{sub 4}(TRZ){sub 4}(2,6-NDC){sub 2}-2DMF-4H{sub 2}O (2). Their crystal structures were characterized by single-crystal X-ray diffraction. Structure 1 crystallizes in the P2{sub 1}/n space group with a = 13.609(2) {angstrom}, b = 27.181(5){angstrom}, c = 13.617(3) {angstrom}, {beta} = 92.46(1){sup o}, V = 5032.4(16) {angstrom}{sup 3}, and Z = 4. Structure 2 crystallizes in orthorhombic Pna2{sub 2} space group with a = 30.978(6) {angstrom}, b = 12.620(3) {angstrom}, c = 13.339(3) {angstrom}, V = 5215(2) {angstrom}{sup 3}, and Z = 4. Both structures are analogues of the previously reported Zn{sub 4}(TRZ){sub 4}(1,4-BDC){sub 2}-16H{sub 2}O where the layers of Zn-triazole moieties are pillared by aromatic dicarboxylates to create 3-D open frameworks. Nitrogen sorption studies revealed that these structures have Brunaer-Emmett-Teller (BET) surface areas of 362.1-584.1 m{sup 2}/g. Hydrogen sorption experiments showed they can store 0.84-1.09 wt % H{sub 2} at 77 K and 1 atm. Although they do not contain large pores or surface areas, they possess the hydrogen sorption capacities comparable to those of highly porous metal-organic frameworks.

  11. Structure determination of the clean (001) surface of strained Si on Si{sub 1−x}Ge{sub x}

    SciTech Connect (OSTI)

    Shirasawa, Tetsuroh; Takeda, Sakura Nishino; Takahashi, Toshio

    2015-02-09

    The surface structure of the strained Si(001) (thickness of 20 nm) on Si{sub 1−x}Ge{sub x} (x = 0.1, 0.2, and 0.3) was studied by low-energy electron diffraction (LEED). LEED intensity-energy spectra of the 2 × 1 reconstructed clean surfaces showed a systematic change that indicates the lattice contraction along the [001] direction remains even at the surfaces. The atomic structures were quantitatively determined, and they were compared with the unstrained pristine Si. The differences in the atomic position almost follow the difference in the bulk lattice constant determined by X-ray diffraction measurements. The results indicate that the strain produced at the Si/Si{sub 1−x}Ge{sub x} interface remains unchanged up to the surface layer.

  12. Underpotential deposition of Ag adlayers on Pt(111): Structures and determination of O{sub 2} adsorption on Pt(111)

    SciTech Connect (OSTI)

    Marinkovic, N.S.; Wang, J.X.; Adzic, R.R.

    1997-09-01

    The structure of Ag adlayers deposited at underpotentials in sulfuric acid on Pt(111), and the inhibition of O{sub 2} reduction they cause, have been studied using grazing incident angle x-ray diffraction measurements, as well as linear sweep voltammetry and in situ FTIR spectroscopy. Ag forms a hexagonal incommensurate bilayer, with two mutually commensurate monolayers. It is aligned with the Pt(111) substrate, although slightly expanded. The first monolayer has a commensurate (1 x 1) structure. A second layer causes a restructuring of the first monolayer. Deposition of each monolayer is associated with one voltammetry Peak. A complete inhibition of O{sub 2} reduction on Pt(111) has been observed upon deposition of both, Ag monolayer and bilayer. Analysis of the inhibition of O{sub 2} reduction as a function of the Ag coverage shows that during reduction O{sub 2} adsorbs in a bridge configuration on Pt(111).

  13. A Procedure for Determination of Degradation Acceptance Criteria for Structures and Passive Components in Nuclear Power Plants

    SciTech Connect (OSTI)

    Nie, J.; Braverman, J.; Hofmayer, C.; Choun, Y-S.; Hahm, D.; Choi, I-K.

    2012-01-30

    The Korea Atomic Energy Research Institute (KAERI) has been collaborating with Brookhaven National Laboratory since 2007 to develop a realistic seismic risk evaluation system which includes the consideration of aging of structures and components in nuclear power plants (NPPs). This collaboration program aims at providing technical support to a five-year KAERI research project, which includes three specific areas that are essential to seismic probabilistic risk assessment: (1) probabilistic seismic hazard analysis, (2) seismic fragility analysis including the effects of aging, and (3) a plant seismic risk analysis. The understanding and assessment of age-related degradations of structures, systems, and components and their impact on plant safety is the major goal of this KAERI-BNL collaboration. Four annual reports have been published before this report as a result of the collaboration research.

  14. Improvement of magnetic and structural stabilities in high-quality Co{sub 2}FeSi{sub 1−x}Al{sub x}/Si heterointerfaces

    SciTech Connect (OSTI)

    Yamada, S.; Tanikawa, K.; Oki, S.; Kawano, M.; Miyao, M.; Hamaya, K.

    2014-08-18

    We study high-quality Co{sub 2}FeSi{sub 1−x}Al{sub x} Heusler compound/Si (0 ≤ x ≤ 1) heterointerfaces for silicon (Si)-based spintronic applications. In thermal treatment conditions, the magnetic and structural stabilities of the Co{sub 2}FeSi{sub 1−x}Al{sub x}/Si heterointerfaces are improved with increasing x in Co{sub 2}FeSi{sub 1−x}Al{sub x}. Compared with L2{sub 1}-ordered Co{sub 2}FeSi/Si, B2-ordered Co{sub 2}FeAl/Si can suppress the diffusion of Si atoms into the Heusler-compound structure. This experimental study will provide an important knowledge for applications in Si-based spin transistors with metallic source/drain contacts.

  15. Structure symmetry determination and magnetic evolution in Sr2Ir1–xRhxO4

    SciTech Connect (OSTI)

    Ye, Feng; Wang, Xiaoping; Hoffmann, Christina; Wang, Jinchen; Chi, Songxue; Matsuda, Masaaki; Chakoumakos, Bryan C.; Fernandez-Baca, Jaime A.; Cao, Gang

    2015-11-23

    We use single-crystal neutron diffraction to determine the crystal structure symmetry and to study the magnetic evolution in the rhodium doped iridates Sr2Ir1–xRhxO4 (0 ≤ x ≤ 0.16). Throughout this doping range, the crystal structure retains a tetragonal symmetry (space group I41/a) with two distinct magnetic Ir sites in the unit cell forming staggered IrO6 rotation. Upon Rh doping, the magnetic order is suppressed and the magnetic moment of Ir4+ is reduced from 0.21 μB/Ir for x = 0 to 0.18 μB/Ir for x = 0.12. As a result, the magnetic structure at x = 0.12 is different from that of the parent compound while the moments remain in the basal plane.

  16. Structural determination of importin alpha in complex with beak and feather disease virus capsid nuclear localization signal

    SciTech Connect (OSTI)

    Patterson, Edward I.; Dombrovski, Andrew K.; Swarbrick, Crystall M.D.; Raidal, Shane R.; Forwood, Jade K.

    2013-09-06

    Highlights: •Circovirus capsid proteins contain large nuclear localization signals (NLS). •A method of nuclear import has not been elucidated. •Beak and feather disease virus (BFDV) capsid NLS was crystallized with importin α. •The structure showed BFDV NLS binding to the major site of importin α. •Result shows implications for mechanism of nuclear transport for all circoviruses. -- Abstract: Circoviruses represent a rapidly increasing genus of viruses that infect a variety of vertebrates. Replication requires shuttling viral molecules into the host cell nucleus, a process facilitated by capsid-associated protein (Cap). Whilst a nuclear localization signal (NLS) has been shown to mediate nuclear translocation, the mode of nuclear transport remains to be elucidated. To better understand this process, beak and feather disease virus (BFDV) Cap NLS was crystallized with nuclear import receptor importin-α (Impα). Diffraction yielded structural data to 2.9 Å resolution, and the binding site on both Impα and BFDV Cap NLS were well resolved. The binding mechanism for the major site is likely conserved across circoviruses as supported by the similarity of NLSs in circovirus Caps. This finding illuminates a crucial step for infection of host cells by this viral family, and provides a platform for rational drug design against the binding interface.

  17. Dominance of interface chemistry over the bulk properties in determining the electronic structure of epitaxial metal/perovskite oxide heterojunctions

    SciTech Connect (OSTI)

    Chambers, Scott A.; Du, Yingge; Gu, Meng; Droubay, Timothy C.; Hepplestone, Steven; Sushko, Petr

    2015-06-09

    We show that despite very similar crystallographic properties and work function values in the bulk, epitaxial Fe and Cr metallizations on Nb:SrTiO3(001) generate completely different heterojunction electronic properties. Cr is Ohmic whereas Fe forms a Schottky barrier with a barrier height of 0.50 eV. This contrast arises because of differences in interface chemistry. In contrast to Cr [Chambers, S. A. et al., Adv. Mater. 2013, 25, 4001.], Fe exhibits a +2 oxidation state and occupies Ti sites in the perovskite lattice, resulting in negligible charge transfer to Ti, upward band bending, and Schottky barrier formation. The differences between Cr and Fe are understood by performing first-principles calculations of the energetics of defect formation which corroborate the observed interface chemistry and structure.

  18. X-ray absorption fine structure spectroscopic determination of plutonium speciation at the Rocky Flats environmental technology

    SciTech Connect (OSTI)

    Lezama-pacheco, Juan S; Conradson, Steven D; Clark, David L

    2008-01-01

    X-ray Absorption Fine Structure spectroscopy was used to probe the speciation of the ppm level Pu in thirteen soil and concrete samples from the Rocky Flats Environmental Technology Site in support of the site remediation effort that has been successfully completed since these measurements. In addition to X-ray Absorption Near Edge Spectra, two of the samples yielded Extended X-ray Absorption Fine Structure spectra that could be analyzed by curve-fits. Most of these spectra exhibited features consistent with PU(IV), and more specificaJly, PuO{sub 2+x}-type speciation. Two were ambiguous, possibly indicating that Pu that was originally present in a different form was transforming into PuO{sub 2+x}, and one was interpreted as demonstrating the presence of an unusual Pu(VI) compound, consistent with its source being spills from a PUREX purification line onto a concrete floor and the resultant extreme conditions. These experimental results therefore validated models that predicted that insoluble PuO{sub 2+x} would be the most stable form of Pu in equilibrium with air and water even when the source terms were most likely Pu metal with organic compounds or a Pu fire. A corollary of these models' predictions and other in situ observations is therefore that the minimal transport of Pu that occurred on the site was via the resuspension and mobilization of colloidal particles. Under these conditions, the small amounts of diffusely distributed Pu that were left on the site after its remediation pose only a negligible hazard.

  19. Improvements of biomass deconstruction enzymes

    SciTech Connect (OSTI)

    Sale, K. L.

    2012-03-01

    Sandia National Laboratories and DSM Innovation, Inc. collaborated on the investigation of the structure and function of cellulases from thermophilic fungi. Sandia's role was to use its expertise in protein structure determination and X-ray crystallography to solve the structure of these enzymes in their native state and in their substrate and product bound states. Sandia was also tasked to work with DSM to use the newly solved structure to, using computational approaches, analyze enzyme interactions with both bound substrate and bound product; the goal being to develop approaches for rationally designing improved cellulases for biomass deconstruction. We solved the structures of five cellulases from thermophilic fungi. Several of these were also solved with bound substrate/product, which allowed us to predict mutations that might enhance activity and stability.

  20. Structure of a complex of uridine phosphorylase from Yersinia pseudotuberculosis with the modified bacteriostatic antibacterial drug determined by X-ray crystallography and computer analysis

    SciTech Connect (OSTI)

    Balaev, V. V.; Lashkov, A. A. Gabdoulkhakov, A. G.; Seregina, T. A.; Dontsova, M. V.; Mikhailov, A. M.

    2015-03-15

    Pseudotuberculosis and bubonic plague are acute infectious diseases caused by the bacteria Yersinia pseudotuberculosis and Yersinia pestis. These diseases are treated, in particular, with trimethoprim and its modified analogues. However, uridine phosphorylases (pyrimidine nucleoside phosphorylases) that are present in bacterial cells neutralize the action of trimethoprim and its modified analogues on the cells. In order to reveal the character of the interaction of the drug with bacterial uridine phosphorylase, the atomic structure of the unligated molecule of uridine-specific pyrimidine nucleoside phosphorylase from Yersinia pseudotuberculosis (YptUPh) was determined by X-ray diffraction at 1.7 Å resolution with high reliability (R{sub work} = 16.2, R{sub free} = 19.4%; r.m.s.d. of bond lengths and bond angles are 0.006 Å and 1.005°, respectively; DPI = 0.107 Å). The atoms of the amino acid residues of the functionally important secondary-structure elements—the loop L9 and the helix H8—of the enzyme YptUPh were located. The three-dimensional structure of the complex of YptUPh with modified trimethoprim—referred to as 53I—was determined by the computer simulation. It was shown that 53I is a pseudosubstrate of uridine phosphorylases, and its pyrimidine-2,4-diamine group is located in the phosphate-binding site of the enzyme YptUPh.

  1. In-situ Mass Spectrometric Determination of Molecular Structural Evolution at the Solid Electrolyte Interphase in Lithium-Ion Batteries

    SciTech Connect (OSTI)

    Zhu, Zihua; Zhou, Yufan; Yan, Pengfei; Vemuri, Venkata Rama Ses; Xu, Wu; Zhao, Rui; Wang, Xuelin; Thevuthasan, Suntharampillai; Baer, Donald R.; Wang, Chong M.

    2015-08-19

    Dynamic molecular evolution at solid/liquid electrolyte interface is always a mystery for a rechargeable battery due to the challenge to directly probe/observe the solid/liquid interface under reaction conditions, which in essence appears to be similarly true for all the fields involving solid/liquid phases, such as electrocatalysis, electrodeposition, biofuel conversion, biofilm, and biomineralization, We use in-situ liquid secondary ion mass spectroscopy (SIMS) for the first time to directly observe the molecular structural evolution at the solid electrode/liquid electrolyte interface for a lithium (Li)-ion battery under dynamic operating conditions. We have discovered that the deposition of Li metal on copper electrode leads to the condensation of solvent molecules around the electrode. Chemically, this layer of solvent condensate tends to deplete the salt anion and with low concentration of Li+ ions, which essentially leads to the formation of a lean electrolyte layer adjacent to the electrode and therefore contributes to the overpotential of the cell. This unprecedented molecular level dynamic observation at the solid electrode/liquid electrolyte interface provides vital chemical information that is needed for designing of better battery chemistry for enhanced performance, and ultimately opens new avenues for using liquid SIMS to probe molecular evolution at solid/liquid interface in general.

  2. Atomic-scale imaging and electronic structure determination of catalytic sites on Pd/Cu near surface alloys

    SciTech Connect (OSTI)

    Tierney, H.L.; Baber, A.E.; Sykes, E.C.H.

    2009-04-15

    Water-gas shift chemistry provides a useful method for producing hydrogen from coal; however, fuel cell applications demand that this hydrogen be free of impurities. Due to their unique properties, Pd/Cu alloys represent an import class of materials used for H purification membranes and also serve as the active metals in many heterogeneous catalysts. Little is known about how Pd and Cu interact electronically in these mixed systems and there is debate in the literature over the direction of charge transfer between the two species. This study used the differential conductance (dI/dV) spectroscopy capabilities of a low-temperature scanning tunneling microscope (STM) to investigate the atomic-scale electronic structure of Pd/Cu surface alloys. dI/dV spectroscopy gives a direct measure of the local density of states of surface sites with subnanometer precision. Results from this work demonstrate that individual, isolated Pd atoms in a Cu lattice are almost electronically identical to their host atoms. Over an energy range that spans 1 eV on either side of the Fermi level, the only significant electronic difference between isolated Pd and their host Cu atoms is that Pd atoms have a very slightly depleted electron density in the region of the Cu surface state maximum.

  3. Surface structure determinations of ordered sulfur overlayers on Mo(100) and Re(0001) by low-energy electron diffraction intensity analysis

    SciTech Connect (OSTI)

    Jentz, D.W.

    1992-11-01

    A newly developed method for surface structure determination, tensor LEED, combined with automated search was used to analyze the structures. The ordered structures of S on Mo(100) which were studied formed a c(2 {times} 2), c(4 {times} 2), and p(2 {times} l) periodicities at coverages of 0.5, 0.75, 1.0 ML (monolayers, of one sulfur atom per one molybdenum atom) respectively. A MO{sub 2}S-like overlayer, which formed at coverages greater than 1.0 ML, is also discussed. Calculations for the c(2 {times} 2) structure gave a best fit geometry with S adsorbed in a four-fold symmetric hollow site and the second layer buckled by 0.09{Angstrom}. The S-Mo bond length is 2.45{Angstrom} and the Pendry R-factor is 0.21. Preliminary calculations for the c(4 {times} 2) structure did not yield an acceptable fit. The three models tried are discussed. Calculations for p(2 {times} l) data did not yield an acceptable geometry either. The types of models that were tried are discussed. Implications of this analysis are discussed along with results of a scanning tunneling microscopy (STM) investigation. The ordered structures on the RE(0001) surface studied have p(2 {times} 2) and (2{radical}3 {times} 2{radical}3)R30{degree} periodicities and occurred at S coverages of 0.25 and 0.5 ML respectively. Best fit structure for p(2 {times} 2) structure has S adsorbed in a three-fold hollow hcp site and exhibits a buckling of the first and second Re layers. The first layer is buckled by 0.05{Angstrom} and the second layer is buckled by 0.06{Angstrom}. Re-S bond length is 2.32{Angstrom} and Pendry R-factor is 0.21. Preliminary results of dynamical LEED investigation of (2{radical}3 {times} 2{radical}3)R30{degree} structure show reasonable agreement with a model with a 6-S atom basis.

  4. History and Solution of the Phase Problem in theTheory of Structure Determination of Crystals from X-ray Diffraction Experiments

    ScienceCinema (OSTI)

    Wolf, Emil [University of Rochester, Rochester, New York, United States

    2010-09-01

    Since the pioneering work of Max von Laue on interference and diffraction of x-rays, carried out almost 100 years ago, numerous attempts have been made to determine structures of crystalline media from x-ray diffraction experiments. The usefulness of all of them has been limited by the inability of measuring phases of the diffracted beams. In this talk, the most important research carried out in this field will be reviewed and a recently obtained solution of the phase problem will be presented.

  5. Structure and band gap determination of irradiation-induced amorphous nano-channels in LiNbO{sub 3}

    SciTech Connect (OSTI)

    Sachan, R. Pakarinen, O. H.; Chisholm, M. F.; Liu, P.; Patel, M. K.; Zhang, Y.; Wang, X. L.; Weber, W. J.

    2015-04-07

    The irradiation of lithium niobate with swift heavy ions results in the creation of amorphous nano-sized channels along the incident ion path. These nano-channels are on the order of a hundred microns in length and could be useful for photonic applications. However, there are two major challenges in these nano-channels characterization: (i) it is difficult to investigate the structural characteristics of these nano-channels due to their very long length and (ii) the analytical electron microscopic analysis of individual ion track is complicated due to electron beam sensitive nature of lithium niobate. Here, we report the first high resolution microscopic characterization of these amorphous nano-channels, widely known as ion-tracks, by direct imaging them at different depths in the material, and subsequently correlating the key characteristics with electronic energy loss of ions. Energetic Kr ions ({sup 84}Kr{sup 22} with 1.98?GeV energy) are used to irradiate single crystal lithium niobate with a fluence of 2 10{sup 10} ions/cm{sup 2}, which results in the formation of individual ion tracks with a penetration depth of ?180??m. Along the ion path, electron energy loss of the ions, which is responsible for creating the ion tracks, increases with depth under these conditions in LiNbO{sub 3}, resulting in increases in track diameter of a factor of ?2 with depth. This diameter increase with electronic energy loss is consistent with predictions of the inelastic thermal spike model. We also show a new method to measure the band gap in individual ion track by using electron energy-loss spectroscopy.

  6. Determination of structure and phase transition of light element nanocomposites in mesoporous silica: case study of NH3BH3 in MCM-41

    SciTech Connect (OSTI)

    Kim, Hyun Jeong; Karkamkar, Abhijeet J.; Autrey, Thomas; Chupas, Peter; Proffen, Thomas E.

    2009-09-30

    The structure of ammonia borane (AB), NH3BH3, infused in mesoporous silica MCM-41 and its evolution over the temperature range of 80 to 300 K was investigated using the atomic pair distribution function (PDF) analysis of synchrotron X-ray powder diffraction data in order to understand the origin of improved dehydrogenation properties of the system. Our study shows how X-ray PDF analysis can be used to elucidate the structure of light guest species loaded in mesoporous silica materials despite of its low scattering power of composed elements (N, B, and H) compared to its host (SiO2). PDF analyses of two AB-loaded compositions with weight ratio AB:MCM-41=1:1 and 3:1 provide a strong evidence that AB aggregate, previously found in AB:MCM-41?1:1 samples, is same species as neat AB. For both of them an orthorhombic to tetragonal structural phase transition occurs at 225 K on warming. On the other hand, AB residing inside meso-pores, which is found in AB:MCM-41=1:2 sample, does not undergo such phase transition. It rather stays in tetragonal phase over a wide temperature range of 110 to 240 K and starts to lose structural correlation above 240 K. This strongly suggests that nano-confinement of AB inside meso-pores stabilizes high temperature tetragonal phase at much lower temperature. These results provide important clues to two critical questions: why nan-compositions of AB leads dehydrogenation to lower temperature and why the neat AB like propoerties are recovered at high AB loading samples. This work was supported by the US Department of Energy Office of Basic Energy Sciences, Chemical Sciences program. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  7. DOE ER63951-3 Final Report: An Integrated Assessment of Geochemical and Community Structure Determinants of Metal Reduction Rates in Subsurface Sediments

    SciTech Connect (OSTI)

    Susan Pfiffner

    2010-06-28

    The objective of this research was to examine the importance of microbial community structure in influencing uranium reduction rates in subsurface sediments. If the redox state alone is the key to metal reduction, then any organisms that can utilize the oxygen and nitrate in the subsurface can change the geochemical conditions so metal reduction becomes an energetically favored reaction. Thus, community structure would not be critical in determining rates or extent of metal reduction unless community structure influenced the rate of change in redox. Alternatively, some microbes may directly catalyze metal reduction (e.g., specifically reduce U). In this case the composition of the community may be more important and specific types of electron donors may promote the production of communities that are more adept at U reduction. Our results helped determine if the type of electron donor or the preexisting community is important in the bioremediation of metal-contaminated environments subjected to biostimulation. In a series of experiments at the DOE FRC site in Oak Ridge we have consistently shown that all substrates promoted nitrate reduction, while glucose, ethanol, and acetate always promoted U reduction. Methanol only occasionally promoted extensive U reduction which is possibly due to community heterogeneity. There appeared to be limitations imposed on the community related to some substrates (e.g. methanol and pyruvate). Membrane lipid analyses (phospholipids and respiratory quinones) indicated different communities depending on electron donor used. Terminal restriction fragment length polymorphism and clone libraries indicated distinct differences among communities even in treatments that promoted U reduction. Thus, there was enough metabolic diversity to accommodate many different electron donors resulting in the U bioimmobilization.

  8. Improved low-lying energy levels determined from solar coronal forbidden and spin-forbidden lines in the 500-1500 A range

    SciTech Connect (OSTI)

    Feldman, U.; Doschek, G.A. . E-mail: george.doschek@nrl.navy.mil

    2007-09-15

    We list observed parity-forbidden and spin-forbidden lines in the 500-1600 A range emitted by solar coronal plasmas and derive improved energy levels from their wavelengths. The lines, emitted by astrophysical abundant elements, belong to transitions within the ground configurations of the type ns{sup 2} np {sup k}, for n = 2, 3 and k = 0-5, and between the lowest term of the first excited configuration 2s2p {sup k+1} and the 2s{sup 2}2p {sup k} ground configurations for k = 0, 1, 2. For each line we give the newly measured wavelength, and the measured or predicted wavelength from the NIST Atomic Spectra Database (ASD) (which except for a few cases includes the previously reported compilation of Kaufman and Sugar [J. Phys. Chem. Ref. Data 15 (1986) 321]), and the values of the transition probability taken from the ASD and CHIANTI database. The list contains measured wavelengths of 136 lines of which over 100 were not available for the Kaufman and Sugar compilation. In addition we provide energy levels that were derived from the reported lines.

  9. Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

    SciTech Connect (OSTI)

    Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; Chan, Sun; Jeffery, Charmaine M.; Price, Roger I.

    2015-09-01

    In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods are significantly affected by the presence of trace-metal contaminants.

  10. Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; Chan, Sun; Jeffery, Charmaine M.; Price, Roger I.

    2015-09-01

    In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods aremore » significantly affected by the presence of trace-metal contaminants.« less

  11. Production of ?Cu by the natZn(p,?) reaction: Improved separation and specific activity determination by titration with three chelators

    SciTech Connect (OSTI)

    Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; Chan, Sun; Jeffery, Charmaine M.; Price, Roger I.

    2015-09-01

    In this study, the cyclotron-based production of position-emitting ?Cu using the (p,?) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched ??Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ?Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ?Cu determined using ICP-MS analysis ranged from 143.314.3(SD) to 506.250.6 MBq/?g while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.70.2 to 412.515.3 MBq/?g), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods are significantly affected by the presence of trace-metal contaminants.

  12. Improved Pharmacological and Structural Properties of HIV Fusion Inhibitor AP3 over Enfuvirtide: Highlighting Advantages of Artificial Peptide Strategy

    SciTech Connect (OSTI)

    Zhu, Xiaojie; Zhu, Yun; Ye, Sheng; Wang, Qian; Xu, Wei; Su, Shan; Sun, Zhiwu; Yu, Fei; Liu, Qi; Wang, Chao; Zhang, Tianhong; Zhang, Zhenqing; Zhang, Xiaoyan; Xu, Jianqing; Du, Lanying; Liu, Keliang; Lu, Lu; Zhang, Rongguang; Jiang, Shibo

    2015-08-19

    Enfuvirtide (T20), is the first HIV fusion inhibitor approved for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, its clinical application is limited because of short half-life, drug resistance and cross-reactivity with the preexisting antibodies in HIV-infected patients. Using an artificial peptide strategy, we designed a peptide with non-native protein sequence, AP3, which exhibited potent antiviral activity against a broad spectrum of HIV-1 strains, including those resistant to T20, and had remarkably longer in vivo half-life than T20. While the preexisting antibodies in HIV-infected patients significantly suppressed T20’s antiviral activity, these antibodies neither recognized AP3, nor attenuated its anti-HIV-1 activity. Structurally different from T20, AP3 could fold into single-helix and interact with gp41 NHR. The two residues, Met and Thr, at the N-terminus of AP3 form a hook-like structure to stabilize interaction between AP3 and NHR helices. Therefore, AP3 has potential for further development as a new HIV fusion inhibitor with improved antiviral efficacy, resistance profile and pharmacological properties over enfuvirtide. Meanwhile, this study highlighted the advantages of artificially designed peptides, and confirmed that this strategy could be used in developing artificial peptide-based viral fusion inhibitors against HIV and other enveloped viruses.

  13. Effect of improved TLD dosimetry on the determination of dose rate constants for {sup 125}I and {sup 103}Pd brachytherapy seeds

    SciTech Connect (OSTI)

    Rodriguez, M.; Rogers, D. W. O.

    2014-11-01

    Purpose: To more accurately account for the relative intrinsic energy dependence and relative absorbed-dose energy dependence of TLDs when used to measure dose rate constants (DRCs) for {sup 125}I and {sup 103}Pd brachytherapy seeds, to thereby establish revised “measured values” for all seeds and compare the revised values with Monte Carlo and consensus values. Methods: The relative absorbed-dose energy dependence, f{sup rel}, for TLDs and the phantom correction, P{sub phant}, are calculated for {sup 125}I and {sup 103}Pd seeds using the EGSnrc BrachyDose and DOSXYZnrc codes. The original energy dependence and phantom corrections applied to DRC measurements are replaced by calculated (f{sup rel}){sup −1} and P{sub phant} values for 24 different seed models. By comparing the modified measured DRCs to the MC values, an appropriate relative intrinsic energy dependence, k{sub bq}{sup rel}, is determined. The new P{sub phant} values and relative absorbed-dose sensitivities, S{sub AD}{sup rel}, calculated as the product of (f{sup rel}){sup −1} and (k{sub bq}{sup rel}){sup −1}, are used to individually revise the measured DRCs for comparison with Monte Carlo calculated values and TG-43U1 or TG-43U1S1 consensus values. Results: In general, f{sup rel} is sensitive to the energy spectra and models of the brachytherapy seeds. Values may vary up to 8.4% among {sup 125}I and {sup 103}Pd seed models and common TLD shapes. P{sub phant} values depend primarily on the isotope used. Deduced (k{sub bq}{sup rel}){sup −1} values are 1.074 ± 0.015 and 1.084 ± 0.026 for {sup 125}I and {sup 103}Pd seeds, respectively. For (1 mm){sup 3} chips, this implies an overall absorbed-dose sensitivity relative to {sup 60}Co or 6 MV calibrations of 1.51 ± 1% and 1.47 ± 2% for {sup 125}I and {sup 103}Pd seeds, respectively, as opposed to the widely used value of 1.41. Values of P{sub phant} calculated here have much lower statistical uncertainties than literature values, but

  14. In situ wettability determination improves formation evalution

    SciTech Connect (OSTI)

    Desbrandes, R. )

    1989-08-01

    Wettability is an important petrophysic parameter which affects capillary pressure, relative permeability, electric properties, water cut production, waterflood behavior, and enhanced recovery. This article describes in situ wettability laboratory experiments and field studies. A laboratory model has been built with a 12-ft long 4-in. clear plastic pipe. A 1 7/8-in. slotted plastic liner has been placed on one side. Ottawa sand F-95 has been packed in the annulus either nontreated, in its naturally water wet condition, or after a silane treatment to render it oil wet. Provided in the sand pack for measurement are 12 pressure pickups with an accurate Omega digital pressure gage. A typical pressure profile recorded during oil drive in a water saturated water wet sand pack is shown. The front was left to stabilize for 60 days. A pressure profile recorded during a water drive in an oil saturated oil wet sand pack is shown. The abrupt change from the water pressure gradient can be seen clearly for the water wet and the oil wet sand. It occurs exactly as expected. The measurements show that the change occurs in less than 4 in. which is the distance between two pressure pickups.

  15. Preliminary Determination Regarding Energy Efficiency Improvements...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Neutral (tradeoff of additional lighting power for additional control) 99 90.1-2010dk 9. ... ASHRAE 90.1 and 62.1, NEMA MG 1, and NFPA 70 and 96. Neutral (updates references ...

  16. Improved aethalometer

    DOE Patents [OSTI]

    Hansen, A.D.

    1988-01-25

    An improved aethalometer having a single light source and a single light detector and two light paths from the light source to the light detector. A quartz fiber filter is inserted in the device, the filter having a collection area in one light path and a reference area in the other light path. A gas flow path through the aethalometer housing allows ambient air to flow through the collection area of the filter so that aerosol particles can be collected on the filter. A rotating disk with an opening therethrough allows light for the light source to pass alternately through the two light paths. The voltage output of the detector is applied to a VCO and the VCO pulses for light transmission separately through the two light paths, are counted and compared to determine the absorption coefficient of the collected aerosol particles. 5 figs.

  17. Determining the Crystal Structure of the aa-CoA Synthase Npht7: Cooperative Research and Development Final Report, CRADA Number CRD-13-533

    SciTech Connect (OSTI)

    Lunin, V.

    2015-02-01

    Attempt to obtain crystals of diffractable quality from protein sample provided by OPX and solve the structure of the aa-CoA synthase enzyme.

  18. HYDRODYNAMICAL SIMULATIONS TO DETERMINE THE FEEDING RATE OF BLACK HOLES BY THE TIDAL DISRUPTION OF STARS: THE IMPORTANCE OF THE IMPACT PARAMETER AND STELLAR STRUCTURE

    SciTech Connect (OSTI)

    Guillochon, James; Ramirez-Ruiz, Enrico

    2013-04-10

    The disruption of stars by supermassive black holes has been linked to more than a dozen flares in the cores of galaxies out to redshift z {approx} 0.4. Modeling these flares properly requires a prediction of the rate of mass return to the black hole after a disruption. Through hydrodynamical simulation, we show that aside from the full disruption of a solar mass star at the exact limit where the star is destroyed, the common assumptions used to estimate M-dot (t), the rate of mass return to the black hole, are largely invalid. While the analytical approximation to tidal disruption predicts that the least-centrally concentrated stars and the deepest encounters should have more quickly-peaked flares, we find that the most-centrally concentrated stars have the quickest-peaking flares, and the trend between the time of peak and the impact parameter for deeply penetrating encounters reverses beyond the critical distance at which the star is completely destroyed. We also show that the most-centrally concentrated stars produced a characteristic drop in M-dot (t) shortly after peak when a star is only partially disrupted, with the power law index n being as extreme as -4 in the months immediately following the peak of a flare. Additionally, we find that n asymptotes to {approx_equal} - 2.2 for both low- and high-mass stars for approximately half of all stellar disruptions. Both of these results are significantly steeper than the typically assumed n = -5/3. As these precipitous decay rates are only seen for events in which a stellar core survives the disruption, they can be used to determine if an observed tidal disruption flare produced a surviving remnant. We provide fitting formulae for four fundamental quantities of tidal disruption as functions of the star's distance to the black hole at pericenter and its stellar structure: the total mass lost, the time of peak, the accretion rate at peak, and the power-law index shortly after peak. These results should be taken into

  19. Fine precipitation scenarios of AlZnMg(Cu) alloys revealed by advanced atomic-resolution electron microscopy study Part I: Structure determination of the precipitates in AlZnMg(Cu) alloys

    SciTech Connect (OSTI)

    Liu, J.Z.; Chen, J.H.; Yuan, D.W.; Wu, C.L.; Zhu, J.; Cheng, Z.Y.

    2015-01-15

    Although they are among the most important precipitation-hardened materials for industry applications, the high-strength AlZnMg(Cu) alloys have thus far not yet been understood adequately about their underlying precipitation scenarios in relation with the properties. This is partly due to the fact that the structures of a number of different precipitates involved in electron microscopy in association with quantitative image simulations have to be employed; a systematic study of these hardening precipitates in different alloys is also necessary. In Part I of the present study, it is shown that there are five types of structurally different precipitates including the equilibrium η-phase precipitate. Using two state-of-the-art atomic-resolution imaging techniques in electron microscopy in association with quantitative image simulations, we have determined and clarified all the unknown precipitate structures. It is demonstrated that atomic-resolution imaging can directly suggest approximate structure models, whereas quantitative image analysis can refine the structure details that are much smaller than the resolution of the microscope. This combination is crucially important for solving the difficult structure problems of the strengthening precipitates in AlZnMg(Cu) alloys. - Highlights: Part I: • We determine and verify all the key precipitate structures in AlMgZn(Cu) alloys. • We employ aberration-corrected scanning transmission electron microscopy (STEM). • We use aberration-corrected high-resolution TEM (HRTEM) for the investigations. • We obtain atomic-resolution images of the precipitates and model their structures. • We refine all precipitate structures with quantitative image simulation analysis. Part II: • The hardening precipitates in AlZnMg alloys shall be classified into two groups. • Two precipitation scenarios coexist in the alloys. • The precipitation behavior of such an alloy depends on the alloy's composition. • Very detailed phase/structure

  20. Means of determining extrusion temperatures

    DOE Patents [OSTI]

    McDonald, Robert E.; Canonico, Domenic A.

    1977-01-01

    In an extrusion process comprising the steps of fabricating a metal billet, heating said billet for a predetermined time and at a selected temperature to increase its plasticity and then forcing said heated billet through a small orifice to produce a desired extruded object, the improvement comprising the steps of randomly inserting a plurality of small metallic thermal tabs at different cross sectional depths in said billet as a part of said fabricating step, and examining said extruded object at each thermal tab location for determining the crystal structure at each extruded thermal tab thus revealing the maximum temperature reached during extrusion in each respective tab location section of the extruded object, whereby the thermal profile of said extruded object during extrusion may be determined.

  1. Determination of the structural changes by Raman and {sup 13}C CP/MAS NMR spectroscopy on native corn starch with plasticizers

    SciTech Connect (OSTI)

    Cozar, O.; Filip, C.; Tripon, C.; Cioica, N.; Coţa, C.; Nagy, E. M.

    2013-11-13

    The plasticizing - antiplasticizing effect of water and glycerol contents on native corn starch samples is investigated by FT-Raman and {sup 13}C CP/MAS NMR spectroscopy. The presence of both amorphous and crystalline structural phases was evidenced in pure native corn starch and also in the samples containing plasticizers. Among the crystalline starch structures, the A- and V- types were suggested by CP/MAS NMR spectra.

  2. Structural Determinants of Nitroxide Motion in Spin-labeled Proteins: Tertiary Contact and Solvent-inaccessible Sties in Helix G of T4 Lysozyme

    SciTech Connect (OSTI)

    Guo,Z.; Cascio, D.; Hideg, K.; Kalai, T.; Hubbell, W.

    2007-01-01

    A nitroxide side chain (R1) has been substituted at single sites along a helix-turn-helix motif in T4 lysozyme (residues 114-135). Together with previously published data, the new sites reported complete a continuous scan through the motif. Mutants with R1 at sites 115 and 118 were selected for crystallographic analysis to identify the structural origins of the corresponding two-component EPR spectra. At 115, R1 is shown to occupy two rotamers in the room temperature crystal structure, one of which has not been previously reported. The two components in the EPR spectrum apparently arise from differential interactions of the two rotamers with the surrounding structure, the most important of which is a hydrophobic interaction of the nitroxide ring. Interestingly, the crystal structure at 100 K reveals a single rotamer, emphasizing the possibility of rotamer selection in low-temperature crystal structures. Residue 118 is at a solvent-inaccessible site in the protein core, and the structure of 118R1, the first reported for the R1 side chain at a buried site, reveals how the side chain is accommodated in an overpacked core.

  3. Categorical Exclusion Determinations: B6.3 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3 Categorical Exclusion Determinations: B6.3 Existing Regulations B6.3: Improvements to environmental control systems Improvements to environmental monitoring and control systems of an existing building or structure (such as changes to scrubbers in air quality control systems or ion-exchange devices and other filtration processes in water treatment systems), provided that during subsequent operations (1) any substance collected by the environmental control systems would be recycled, released, or

  4. Crystal structure refinement with SHELXL

    SciTech Connect (OSTI)

    Sheldrick, George M., E-mail: gsheldr@shelx.uni-ac.gwdg.de [Department of Structural Chemistry, Georg-August Universitt Gttingen, Tammannstrae 4, Gttingen 37077 (Germany)

    2015-01-01

    New features added to the refinement program SHELXL since 2008 are described and explained. The improvements in the crystal structure refinement program SHELXL have been closely coupled with the development and increasing importance of the CIF (Crystallographic Information Framework) format for validating and archiving crystal structures. An important simplification is that now only one file in CIF format (for convenience, referred to simply as a CIF) containing embedded reflection data and SHELXL instructions is needed for a complete structure archive; the program SHREDCIF can be used to extract the .hkl and .ins files required for further refinement with SHELXL. Recent developments in SHELXL facilitate refinement against neutron diffraction data, the treatment of H atoms, the determination of absolute structure, the input of partial structure factors and the refinement of twinned and disordered structures. SHELXL is available free to academics for the Windows, Linux and Mac OS X operating systems, and is particularly suitable for multiple-core processors.

  5. Categorical Exclusion Determinations: B2.1 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1 Categorical Exclusion Determinations: B2.1 Existing Regulations B2.1: Workplace enhancements Modifications within or contiguous to an existing structure, in a previously disturbed or developed area, to enhance workplace habitability (including, but not limited to, installation or improvements to lighting, radiation shielding, or heating/ventilating/air conditioning and its instrumentation, and noise reduction). Previous Regulations Categorical Exclusion Determinations dated before November

  6. Sol-gel Ru/SiO[sub 2] - catalysts: Theoretical and experimental determination of the Ru-in-silica structures

    SciTech Connect (OSTI)

    Lopez, T.; Gomez, R.; Novaro, O. ); Ramirez-Solis, A.; Sanchez-Mora, E.; Castillo, S.; Poulain, E.; Martinez-Magadan, J.M. )

    1993-05-01

    Preparation of Ru/SiO[sub 2] catalysts with sol-gel techniques allows better selectivity and much greater resistance to coke formation and deactivation than the traditional impregnation method. This has been attributed to the incorporation of Ru into the silica network for the sol-gel catalyst. To further understand the structure of the Ru occluded in the silica network, a variety of spectroscopical studies and quantum mechanical calculations were carried out, confirming previously proposed structures and showing good agreement between the theoretical and experimental results. 26 refs., 10 figs., 2 tabs.

  7. Synthesis, Improved Antisense Activity and Structural Rationale for the Divergent RNA Affinities of 3;#8242;-Fluoro Hexitol Nucleic Acid (FHNA and Ara-FHNA) Modified Oligonucleotides

    SciTech Connect (OSTI)

    Egli, Martin; Pallan, Pradeep S.; Allerson, Charles R.; Prakash, Thazha P.; Berdeja, Andres; Yu, Jinghua; Lee, Sam; Watt, Andrew; Gaus, Hans; Bhat, Balkrishen; Swayze, Eric E.; Seth, Punit P.

    2012-03-16

    The synthesis, biophysical, structural, and biological properties of both isomers of 3'-fluoro hexitol nucleic acid (FHNA and Ara-FHNA) modified oligonucleotides are reported. Synthesis of the FHNA and Ara-FHNA thymine phosphoramidites was efficiently accomplished starting from known sugar precursors. Optimal RNA affinities were observed with a 3'-fluorine atom and nucleobase in a trans-diaxial orientation. The Ara-FHNA analog with an equatorial fluorine was found to be destabilizing. However, the magnitude of destabilization was sequence-dependent. Thus, the loss of stability is sharply reduced when Ara-FHNA residues were inserted at pyrimidine-purine (Py-Pu) steps compared to placement within a stretch of pyrimidines (Py-Py). Crystal structures of A-type DNA duplexes modified with either monomer provide a rationalization for the opposing stability effects and point to a steric origin of the destabilization caused by the Ara-FHNA analog. The sequence dependent effect can be explained by the formation of an internucleotide C-F {hor_ellipsis} H-C pseudo hydrogen bond between F3' of Ara-FHNA and C8-H of the nucleobase from the 3'-adjacent adenosine that is absent at Py-Py steps. In animal experiments, FHNA-modified antisense oligonucleotides formulated in saline showed a potent downregulation of gene expression in liver tissue without producing hepatotoxicity. Our data establish FHNA as a useful modification for antisense therapeutics and also confirm the stabilizing influence of F(Py) {hor_ellipsis} H-C(Pu) pseudo hydrogen bonds in nucleic acid structures.

  8. Structure of a B{sub 6}-like phase formed from bent-core liquid crystals determined by microbeam x-ray diffraction

    SciTech Connect (OSTI)

    Kang, Sungmin; Tokita, Masatoshi; Takanishi, Yoichi; Takezoe, Hideo; Watanabe, Junji

    2007-10-15

    We studied the structure of the B{sub x} phase formed from the short terminal homolog, 1,3-(4-bromobenzene) bis[4-(4-n-butoxyphenylliminomethyl)benzoate] (4Br-P-4-O-PIMB), by focusing a microbeam of x ray on the well-developed fan-shaped texture. From the highly oriented x-ray patterns detected at the two states of DC-ON and DC-OFF, the B{sub x} structure was definitely illustrated. It is a kind of frustrated one similar to the B{sub 1} phase: the molecules lie perpendicularly to the layer, and the frustration takes place perpendicularly to the bent direction. Unlike in the B{sub 1} phase, however, the size of the resulting antidomain is not definite, but fluctuates from position to position as observed in the B{sub 6} phase.

  9. Precise determination of the deuteron spin structure at low to moderate Q2 with CLAS and extraction of the neutron contribution

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Guler, N.; Fersch, R. G.; Kuhn, S. E.; Bosted, P.; Griffioen, K. A.; Keith, C.; Minehart, R.; Prok, Y.; Adhikari, K. P.; Adikaram, D.; et al

    2015-11-02

    In this study, we present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron (15ND3) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry Ad1 and the polarized structure function gd1 were extracted over a wide kinematic range (0.05 GeV2 < Q2 < 5 GeV2 and 0.9 GeV < W < 3 GeV). We use an unfolding procedure andmore » a parametrization of the corresponding proton results to extract from these data the polarized structure functions An1 and g1n of the (bound) neutron, which are so far unknown in the resonance region, W < 2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x, a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the Operator Product Expansion.« less

  10. Synthesis and X-ray crystal structure determination of N-p-methylphenyl-4-benzoyl-3,4-diphenyl-2-azetidinone

    SciTech Connect (OSTI)

    Kabak, Mehmet; Senoez, Huelya; Elmali, Ayhan; Adar, Vildan; Svoboda, Ingrid; Dusek, Michal; Fejfarova, Karla

    2010-12-15

    The title compound, C{sub 29}H{sub 23}NO{sub 2}, has been characterized by single-crystal X-ray diffraction at two different temperatures (303 K and 120 K) and wavelengths (MoK{sub {alpha}} and CuK{sub {alpha}}). The non-centrosymmetric hexagonal crystal structure contains four-membered planar {beta}-lactam ring with an unusually long C-C bond. The {beta}-lactam ring is almost planar.

  11. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO{sub 2} by capacitance voltage measurement on inverted metal oxide semiconductor structure

    SciTech Connect (OSTI)

    Zhang, Tian Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan

    2015-10-21

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO{sub 2}. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO{sub 2}/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 10{sup 18}–10{sup 19 }cm{sup −3} despite their high resistivity. The saturation of doping at about 1.4 × 10{sup 19 }cm{sup −3} and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10{sup −3} cm{sup 2}/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  12. Development of improved processing and evaluation methods for high reliability structural ceramics for advanced heat engine applications Phase II. Final report

    SciTech Connect (OSTI)

    Pujari, V.J.; Tracey, D.M.; Foley, M.R.

    1996-02-01

    The research program had as goals the development and demonstration of significant improvements in processing methods, process controls, and nondestructive evaluation (NDE) which can be commercially implemented to produce high reliability silicon nitride components for advanced heat engine applications at temperatures to 1370{degrees}C. In Phase I of the program a process was developed that resulted in a silicon nitride - 4 w% yttria HIP`ed material (NCX 5102) that displayed unprecedented strength and reliability. An average tensile strength of 1 GPa and a strength distribution following a 3-parameter Weibull distribution were demonstrated by testing several hundred buttonhead tensile specimens. The Phase II program focused on the development of methodology for colloidal consolidation producing green microstructure which minimizes downstream process problems such as drying, shrinkage, cracking, and part distortion during densification. Furthermore, the program focused on the extension of the process to gas pressure sinterable (GPS) compositions. Excellent results were obtained for the HIP composition processed for minimal density gradients, both with respect to room-temperature strength and high-temperature creep resistance. Complex component fabricability of this material was demonstrated by producing engine-vane prototypes. Strength data for the GPS material (NCX-5400) suggest that it ranks very high relative to other silicon nitride materials in terms of tensile/flexure strength ratio, a measure of volume quality. This high quality was derived from the closed-loop colloidal process employed in the program.

  13. Global Structure of a Three-Way Junction in a Phi29 Packaging RNA Dimer Determined Using Site-Directed Spin Labeling

    SciTech Connect (OSTI)

    Zhang, Xiaojun; Tung, Chang-Shung; Sowa, Glenna; Hatmal, Ma'mon M.; Haworth, Ian S.; Qin, Peter Z.

    2012-02-08

    The condensation of bacteriophage phi29 genomic DNA into its preformed procapsid requires the DNA packaging motor, which is the strongest known biological motor. The packaging motor is an intricate ring-shaped protein/RNA complex, and its function requires an RNA component called packaging RNA (pRNA). Current structural information on pRNA is limited, which hinders studies of motor function. Here, we used site-directed spin labeling to map the conformation of a pRNA three-way junction that bridges binding sites for the motor ATPase and the procapsid. The studies were carried out on a pRNA dimer, which is the simplest ring-shaped pRNA complex and serves as a functional intermediate during motor assembly. Using a nucleotide-independent labeling scheme, stable nitroxide radicals were attached to eight specific pRNA sites without perturbing RNA folding and dimer formation, and a total of 17 internitroxide distances spanning the three-way junction were measured using Double Electron-Electron Resonance spectroscopy. The measured distances, together with steric chemical constraints, were used to select 3662 viable three-way junction models from a pool of 65 billion. The results reveal a similar conformation among the viable models, with two of the helices (HT and HL) adopting an acute bend. This is in contrast to a recently reported pRNA tetramer crystal structure, in which HT and HL stack onto each other linearly. The studies establish a new method for mapping global structures of complex RNA molecules, and provide information on pRNA conformation that aids investigations of phi29 packaging motor and developments of pRNA-based nanomedicine and nanomaterial.

  14. Efficiency Improvements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    efficiency improvements Efficiency Improvements New Target Alignment Sensor Installed on NIF For successful ignition experiments, NIF's 192 laser beams and targets must be aligned within a tolerance of about 20 microns-about one-fifth the diameter of an average human hair. Achieving this level of precision requires many fine-tuned calibrations and correlations between the laser beams and the target. Earlier this month a key instrument for achieving this level of precision, a new target alignment

  15. Development of improved processing and evaluation methods for high reliability structural ceramics for advanced heat engine applications, Phase 1. Final report

    SciTech Connect (OSTI)

    Pujari, V.K.; Tracey, D.M.; Foley, M.R.; Paille, N.I.; Pelletier, P.J.; Sales, L.C.; Wilkens, C.A.; Yeckley, R.L.

    1993-08-01

    The program goals were to develop and demonstrate significant improvements in processing methods, process controls and non-destructive evaluation (NDE) which can be commercially implemented to produce high reliability silicon nitride components for advanced heat engine applications at temperatures to 1,370{degrees}C. The program focused on a Si{sub 3}N{sub 4}-4% Y{sub 2}O{sub 3} high temperature ceramic composition and hot-isostatic-pressing as the method of densification. Stage I had as major objectives: (1) comparing injection molding and colloidal consolidation process routes, and selecting one route for subsequent optimization, (2) comparing the performance of water milled and alcohol milled powder and selecting one on the basis of performance data, and (3) adapting several NDE methods to the needs of ceramic processing. The NDE methods considered were microfocus X-ray radiography, computed tomography, ultrasonics, NMR imaging, NMR spectroscopy, fluorescent liquid dye penetrant and X-ray diffraction residual stress analysis. The colloidal consolidation process route was selected and approved as the forming technique for the remainder of the program. The material produced by the final Stage II optimized process has been given the designation NCX 5102 silicon nitride. According to plan, a large number of specimens were produced and tested during Stage III to establish a statistically robust room temperature tensile strength database for this material. Highlights of the Stage III process demonstration and resultant database are included in the main text of the report, along with a synopsis of the NCX-5102 aqueous based colloidal process. The R and D accomplishments for Stage I are discussed in Appendices 1--4, while the tensile strength-fractography database for the Stage III NCX-5102 process demonstration is provided in Appendix 5. 4 refs., 108 figs., 23 tabs.

  16. CX-000004: Categorical Exclusion Determination | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    04: Categorical Exclusion Determination CX-000004: Categorical Exclusion Determination Lane-Wendson #1 Structure 10/5 Access Road Improvement and Pole Replacement Project CX(s) Applied: B1.3 Date: 10/08/2009 Location(s): Lane County, Oregon Office(s): Bonneville Power Administration Bonneville Power Administration has a need to replace wood pole structure 10/5 along the Lane-Wendson #1 Transmission line. DOCUMENT(S) AVAILABLE FOR DOWNLOAD CX-000004.pdf (518.71 KB) More Documents &

  17. Comparison between experimental and theoretical determination of the local structure of the GaAs{sub 1-y}N{sub y} dilute nitride alloy

    SciTech Connect (OSTI)

    Ciatto, Gianluca; D'Acapito, Francesco; Sanna, Simone; Fiorentini, Vincenzo; Polimeni, Antonio; Capizzi, Mario; Mobilio, Settimio; Boscherini, Federico

    2005-03-15

    We present a combined experimental and theoretical study of the local structure of the GaAs{sub 1-y}N{sub y} dilute nitride alloy. Experimental results obtained by x-ray absorption spectroscopy have been compared with first-principles density-functional supercell calculations and with the predictions of three different valence force field models. Both experiments and calculations find that inclusion of N induces static disorder in the Ga-As bond length distribution. An increase of the Ga-As bond length upon N incorporation in gallium arsenide has been observed; this is due to the competing effects of the decrease of the free lattice parameter and the tensile strain due to pseudomorphic growth. The different theoretical calculations reproduce more or less accurately this bond length expansion; we discuss the performance of the different valence force field models in predicting the measured bond lengths.

  18. Improving the accuracy of macromolecular structure refinement

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    is challenging at low resolution. We compared refinement methods using synchrotron diffraction data of photosystem I at 7.4 resolution, starting from different initial models...

  19. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

  20. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, J.L.

    1992-12-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

  1. IMPROVED log(gf) VALUES FOR LINES OF Ti I AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937 (ACCURATE TRANSITION PROBABILITIES FOR Ti I)

    SciTech Connect (OSTI)

    Lawler, J. E.; Guzman, A.; Wood, M. P.; Sneden, C.; Cowan, J. J. E-mail: adrianaguzman2014@u.northwestern.edu E-mail: chris@verdi.as.utexas.edu

    2013-04-01

    New atomic transition probability measurements for 948 lines of Ti I are reported. Branching fractions from Fourier transform spectra and from spectra recorded using a 3 m echelle spectrometer are combined with published radiative lifetimes from laser-induced fluorescence measurements to determine these transition probabilities. Generally good agreement is found in comparisons to the NIST Atomic Spectra Database. The new Ti I data are applied to re-determine the Ti abundance in the photospheres of the Sun and metal-poor star HD 84937 using many lines covering a range of wavelength and excitation potential to explore possible non-local thermal equilibrium effects. The variation of relative Ti/Fe abundance with metallicity in metal-poor stars observed in earlier studies is supported in this study.

  2. CX-013633: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Access Road Improvements for Allston-Clatsop No. 1 to Structure 10/1 CX(s) Applied: B1.3Date: 04/22/2015 Location(s): OregonOffices(s): Bonneville Power Administration

  3. CX-008681: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Ostrander-Troutdale No. 1, Structure 16/1, Access Road Improvement Project CX(s) Applied: B1.3 Date: 07/18/2012 Location(s): Oregon Offices(s): Bonneville Power Administration

  4. Experimental phasing for structure determination using membrane...

    Office of Scientific and Technical Information (OSTI)

    ... Copyright (c) Li et al. 2015; This is an open-access article distributed under the terms ... Country of Publication: Denmark Language: English Subject: 75 CONDENSED MATTER PHYSICS, ...

  5. Crystal structure determination of Efavirenz (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Publication Date: 2015-12-23 OSTI Identifier: 22494487 Resource Type: Journal Article Resource Relation: Journal Name: AIP Conference Proceedings; Journal Volume: 1700; Journal ...

  6. Structural Determination of Marine Bacteriogenic Manganese Oxides

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    oxides precipitated around a spore (cell) of the marine Mn(II)-oxidizing bac-terium, Bacillus sp., strain SG-1. This cell is about 0.5 m diameter (small axis). Bacterial...

  7. Spectrometric Determination of Molecular Structural Evolution...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at the Solid Electrolyte Interphase in Lithium-Ion Batteries The first of its kind ... electrolyte interface layer operando for lithium-ion battery Combining of in-situ TEM and ...

  8. Improved Biomass Cooking Stoves | Open Energy Information

    Open Energy Info (EERE)

    TOOL Name: Improved Biomass Cooking Stoves AgencyCompany Organization: various Sector: Energy Focus Area: Biomass Phase: Determine Baseline, Evaluate Options, Prepare a Plan,...

  9. CX-005428: Categorical Exclusion Determination | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    28: Categorical Exclusion Determination CX-005428: Categorical Exclusion Determination Improved Structure and Fabrication of Large High-Power Kinetic Hydropower System Rotors -Year 2 CX(s) Applied: A9, B3.1, B5.1 Date: 03/17/2011 Location(s): New York Office(s): Energy Efficiency and Renewable Energy, Golden Field Office Verdant Power will use the Department of Energy funding to design and test, both in lab and in-water, a next generation advanced waterpower technology - large, high power

  10. CX-010165: Categorical Exclusion Determination | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    165: Categorical Exclusion Determination CX-010165: Categorical Exclusion Determination Libby-Troy Access Road Upgrades CX(s) Applied: B1.3 Date: 03/20/2013 Location(s): Montana Offices(s): Bonneville Power Administration Upgrade and improve access roads from Structures 23/3 through 24/6 on the Libby-Troy section of the Libby-Bonners Ferry No. 1 115-kilovolt (kV) transmission line. CX-010165.pdf (31.85 KB) More Documents & Publications EIS-0379 - Final Environmental Impact Statement

  11. CX-010315: Categorical Exclusion Determination | Department of Energy

    Office of Environmental Management (EM)

    65: Categorical Exclusion Determination CX-010165: Categorical Exclusion Determination Libby-Troy Access Road Upgrades CX(s) Applied: B1.3 Date: 03/20/2013 Location(s): Montana Offices(s): Bonneville Power Administration Upgrade and improve access roads from Structures 23/3 through 24/6 on the Libby-Troy section of the Libby-Bonners Ferry No. 1 115-kilovolt (kV) transmission line. CX-010165.pdf (31.85 KB) More Documents & Publications EIS-0379 - Final Environmental Impact Statement EIS-0379:

  12. CX-007901: Categorical Exclusion Determination | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    CX-007901: Categorical Exclusion Determination Improving Atmospheric Models for Offshore Wind Resource Mapping and Prediction Using LIDAR, Aircraft, and In-Ocean...

  13. CX-100526 Categorical Exclusion Determination | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    This NEPA determination applies to the remaining Tasks 2.0-6.0, including outdoor test support, strain improvement, control optimization, preprocessing unit operations and ...

  14. Structure and yarn sensor for fabric

    DOE Patents [OSTI]

    Mee, David K.; Allgood, Glenn O.; Mooney, Larry R.; Duncan, Michael G.; Turner, John C.; Treece, Dale A.

    1998-01-01

    A structure and yarn sensor for fabric directly determines pick density in a fabric thereby allowing fabric length and velocity to be calculated from a count of the picks made by the sensor over known time intervals. The structure and yarn sensor is also capable of detecting full length woven defects and fabric. As a result, an inexpensive on-line pick (or course) density measurement can be performed which allows a loom or knitting machine to be adjusted by either manual or automatic means to maintain closer fiber density tolerances. Such a sensor apparatus dramatically reduces fabric production costs and significantly improves fabric consistency and quality for woven or knitted fabric.

  15. NREL: Wind Research - Structural Testing Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and improve new blade designs, analyze blade structural properties, and improve their manufacturing processes. As wind turbines grow in size and their blades become longer and...

  16. Polarity of annealing and structural analysis of the RNase H resistant alpha-5'-d(TACACA). beta-5'-r(AUGUGU) hybrid determined by high-field sup 1 H, sup 13 C, and sup 31 P NMR analysis

    SciTech Connect (OSTI)

    Gmeiner, W.H.; Rao, K.E.; Rayner, B.; Vasseur, J.J.; Morvan, F.; Imbach, J.L.; Lown, J.W. )

    1990-11-13

    The novel hybrid duplex alpha-5'-d(TACACA)-3'.beta-5'-r(AUGUGU)-3' was analyzed extensively by 1D and 2D NMR methods. Two forms of the duplex exist in about an 80:20 ratio. Analysis of the exchangeable imino protons of the major component revealed that three AU and one AT base pair are present in addition to two GC base pairs, confirming that the duplex anneals in parallel orientation. The presence of the AT base pair, which can only be accounted for by a parallel duplex, was confirmed by a selective INEPT experiment, which correlated the thymidine imino proton to its C5 carbon. The lesser antiparallel form could be detected by exchangeable and nonexchangeable proton resonances in both strands. An exchange peak was observed in the NOESY spectrum for the thymidine methyl group resonance in both the predominant and lesser conformations, indicating the lifetime of the individual structures was on the millisecond time scale. The nonexchangeable protons of the predominant duplex were assigned by standard methods. The sugar pucker of the ribonucleosides was determined to be of the S type by a pseudorotation analysis according to Altona, with the J-couplings measured from the multiplet components of the phase-sensitive COSY experiment. The NOE pattern observed for the alpha-deoxynucleosides also suggested an S-type sugar pucker. The adoption of an S-type sugar pucker for both strands indicates that, in contrast to RNA.DNA duplexes formed exclusively from beta-nucleotides, the alpha-DNA.beta-RNA duplex may form a B-type helix. The 31P resonances of the alpha and beta strands have very different chemical shifts in the hybrid duplex and the difference persists above the helix melting temperature, indicating an intrinsic difference in 31P chemical shift for nucleotides differing only in the configuration about the glycosidic bond.

  17. Airfoil structure

    DOE Patents [OSTI]

    Frey, Gary A.; Twardochleb, Christopher Z.

    1998-01-01

    Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally "C" configuration of the airfoil. The generally "C" configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion.

  18. Airfoil structure

    DOE Patents [OSTI]

    Frey, G.A.; Twardochleb, C.Z.

    1998-01-13

    Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally ``C`` configuration of the airfoil. The generally ``C`` configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion. 6 figs.

  19. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. One layer of each set of bilayers consist of titanium, and the second layer of each set of bilayers consist of an alloy of nickel with carbon interstitially present in the nickel alloy.

  20. CX-003084: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Maintenance of and Improvements to the Access Roads from Structure 53/3 through 66/3 of the Fairview-Rogue Number 1 Transmission Line CorridorCX(s) Applied: B1.3Date: 06/21/2010Location(s): Curry County, OregonOffice(s): Bonneville Power Administration

  1. CX-001182: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Access Road Improvement Project for Structure 12/1 of the Snoking Tap to Echo Lake-Monroe Number 1 Transmission LineCX(s) Applied: B1.13Date: 03/12/2010Location(s): Snohomish, WashingtonOffice(s): Bonneville Power Administration

  2. CX-001180: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Monroe-Custer Number 1 and 2 500-Kilovolt Transmission Line Structure 16/2 Access Road Improvement and Bridge Replacement ProjectCX(s) Applied: B1.3Date: 03/15/2010Location(s): Snohomish County, WashingtonOffice(s): Bonneville Power Administration

  3. CX-003728: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Improved Structure and Fabrication of Large, High-Power Kinetic Hydropower System Rotors - Year 2CX(s) Applied: A9, B3.1, B5.1Date: 09/16/2010Location(s): New YorkOffice(s): Energy Efficiency and Renewable Energy, Golden Field Office

  4. Efficiency Improvements - 2016

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    6 Efficiency Improvements - 2016 June Dual-Purpose Positioner Installed on NIF March A NIF Record: 17 Shots in a Week January Improving Optics Processing Efficiencies

  5. Hydropower Process Improvements

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Process Improvements William J. Palmer Hydropower Program Manager South Atlantic Division 2 April 2015 BUILDING STRONG Focus Areas For Process Improvements InspectionsCondition ...

  6. Improved multiprocessor garbage collection algorithms

    SciTech Connect (OSTI)

    Newman, I.A.; Stallard, R.P.; Woodward, M.C.

    1983-01-01

    Outlines the results of an investigation of existing multiprocessor garbage collection algorithms and introduces two new algorithms which significantly improve some aspects of the performance of their predecessors. The two algorithms arise from different starting assumptions. One considers the case where the algorithm will terminate successfully whatever list structure is being processed and assumes that the extra data space should be minimised. The other seeks a very fast garbage collection time for list structures that do not contain loops. Results of both theoretical and experimental investigations are given to demonstrate the efficacy of the algorithms. 7 references.

  7. CX-008738: Categorical Exclusion Determination

    Office of Energy Efficiency and Renewable Energy (EERE)

    Determination of Microstructure and Chemical State Changes in Ion-Irradiated Fuels and Structural Components with a High Kinetic Energy Electron Detector – Illinois Institute of Technology CX(s) Applied: B3.6 Date: 05/22/2012 Location(s): Idaho Offices(s): Idaho Operations Office

  8. Improved nuclear fuel assembly grid spacer

    DOE Patents [OSTI]

    Marshall, John; Kaplan, Samuel

    1977-01-01

    An improved fuel assembly grid spacer and method of retaining the basic fuel rod support elements in position within the fuel assembly containment channel. The improvement involves attachment of the grids to the hexagonal channel and of forming the basic fuel rod support element into a grid structure, which provides a design which is insensitive to potential channel distortion (ballooning) at high fluence levels. In addition the improved method eliminates problems associated with component fabrication and assembly.

  9. Graduate Program Salary Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Salary Structure Graduate Program Salary Structure Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive environment that is rich in intellectual vitality and opportunities for growth. Contact Student Programs (505) 665-0987 Email GRA salary determination process Salaries are determined by evaluating students' current transcripts using the following criteria: Salaries for graduate students are based on completion of 12 credit hours annually for the

  10. The roles of RIIbeta linker and N-terminal cyclic nucleotide-binding domain in determining the unique structures of Type IIbeta Protein Kinase A. A small angle X-ray and neutron scattering study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Blumenthal, Donald K.; Copps, Jeffrey; Smith-Nguyen, Eric V.; Zhang, Ping; Heller, William T.; Taylor, Susan S.

    2014-08-11

    Protein kinase A (PKA) is ubiquitously expressed and is responsible for regulating many important cellular functions in response to changes in intracellular cAMP concentrations. Moreover, the PKA holoenzyme is a tetramer (R2:C2), with a regulatory subunit homodimer (R2) that binds and inhibits two catalytic (C) subunits; binding of cAMP to the regulatory subunit homodimer causes activation of the catalytic subunits. Four different R subunit isoforms exist in mammalian cells, and these confer different structural features, subcellular localization, and biochemical properties upon the PKA holoenzymes they form. The holoenzyme containing RIIβ is structurally unique in that the type IIβ holoenzyme ismore » much more compact than the free RIIβ homodimer. We have used small angle x-ray scattering and small angle neutron scattering to study the solution structure and subunit organization of a holoenzyme containing an RIIβ C-terminal deletion mutant (RIIβ(1–280)), which is missing the C-terminal cAMP-binding domain to better understand the structural organization of the type IIβ holoenzyme and the RIIβ domains that contribute to stabilizing the holoenzyme conformation. These results demonstrate that compaction of the type IIβ holoenzyme does not require the C-terminal cAMP-binding domain but rather involves large structural rearrangements within the linker and N-terminal cyclic nucleotide-binding domain of the RIIβ homodimer. The structural rearrangements are significantly greater than seen previously with RIIα and are likely to be important in mediating short range and long range interdomain and intersubunit interactions that uniquely regulate the activity of the type IIβ isoform of PKA.« less

  11. Improved recovery demonstration for Williston basin carbonates. Annual report, June 10, 1994--June 9, 1995

    SciTech Connect (OSTI)

    Sippel, M.; Zinke, S.; Magruder, G.; Eby, D.

    1995-09-01

    The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil in place will result in additional oil recovery by primary and enhanced recovery processes.

  12. Undergraduate Program Salary Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Salary Structure Undergraduate Program Salary Structure Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive environment that is rich in intellectual vitality and opportunities for growth. Contact Student Programs (505) 665-0964 Email Undergraduate salary determination process Salaries are evaluated from students' current transcripts based on college academic progression and hours completed in a degree program. Professional Salary Structure Years

  13. Categorical Exclusion Determinations: Maryland | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Maryland Categorical Exclusion Determinations: Maryland Location Categorical Exclusion Determinations issued for actions in Maryland. DOCUMENTS AVAILABLE FOR DOWNLOAD June 12, 2016 CX-100642 Categorical Exclusion Determination Structural Support of Windows in Walls with Continuous Insulation Award Number: DE-EE0007574 CX(s) Applied: A9, B3.6 Building Technologies Office Date: 6/2/2016 Location(s): MD Office(s): Golden Field Office June 12, 2016 CX-100641 Categorical Exclusion Determination

  14. Solid Oxide Fuel Cell Technologies: Improved Electrode-Electrode...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Solid Oxide Fuel Cell Technologies: Improved Electrode-Electrode Structures for Solid State Electrochemical Devices Lawrence Berkeley National Laboratory Contact LBL About This ...

  15. Improved DC Gun Insulator

    SciTech Connect (OSTI)

    M.L. Neubauer, K.B. Beard, R. Sah, C. Hernandez-Garcia, G. Neil

    2009-05-01

    Many user facilities such as synchrotron light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic, creating a buildup of charge and causing eventual puncture. A novel ceramic manufacturing process is proposed. It will incorporate bulk resistivity in the region where it is needed to bleed off accumulated charge caused by highly energetic electrons. This process will be optimized to provide an appropriate gradient in bulk resistivity from the vacuum side to the air side of the HV standoff ceramic cylinder. A computer model will be used to determine the optimum cylinder dimensions and required resistivity gradient for an example RF gun application. A ceramic material example with resistivity gradient appropriate for use as a DC gun insulator will be fabricated by glazing using doping compounds and tested.

  16. Improved technical specifications

    SciTech Connect (OSTI)

    Hoffman, D.R.

    1994-12-31

    Improved technical specifications for nuclear power plants are outlined. The objectives of this work are to improve safety, provide a clearer understanding of safety significance, and ease NRC and industry administrative burdens. Line item improvements, bases, and implementation of the specifications are discussed.

  17. Refines Efficiency Improvement

    SciTech Connect (OSTI)

    WRI

    2002-05-15

    Refinery processes that convert heavy oils to lighter distillate fuels require heating for distillation, hydrogen addition or carbon rejection (coking). Efficiency is limited by the formation of insoluble carbon-rich coke deposits. Heat exchangers and other refinery units must be shut down for mechanical coke removal, resulting in a significant loss of output and revenue. When a residuum is heated above the temperature at which pyrolysis occurs (340 C, 650 F), there is typically an induction period before coke formation begins (Magaril and Aksenova 1968, Wiehe 1993). To avoid fouling, refiners often stop heating a residuum before coke formation begins, using arbitrary criteria. In many cases, this heating is stopped sooner than need be, resulting in less than maximum product yield. Western Research Institute (WRI) has developed innovative Coking Index concepts (patent pending) which can be used for process control by refiners to heat residua to the threshold, but not beyond the point at which coke formation begins when petroleum residua materials are heated at pyrolysis temperatures (Schabron et al. 2001). The development of this universal predictor solves a long standing problem in petroleum refining. These Coking Indexes have great potential value in improving the efficiency of distillation processes. The Coking Indexes were found to apply to residua in a universal manner, and the theoretical basis for the indexes has been established (Schabron et al. 2001a, 2001b, 2001c). For the first time, a few simple measurements indicates how close undesired coke formation is on the coke formation induction time line. The Coking Indexes can lead to new process controls that can improve refinery distillation efficiency by several percentage points. Petroleum residua consist of an ordered continuum of solvated polar materials usually referred to as asphaltenes dispersed in a lower polarity solvent phase held together by intermediate polarity materials usually referred to as

  18. Challenges for improving estimates of soil organic carbon stored...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    determined, and research efforts that will reduce this discrepancy were identified. Five research challenges for improving empirical assessments of the distribution and potential...

  19. Precise determination of the deuteron spin structure at low to moderate Q2 with CLAS and extraction of the neutron contribution

    SciTech Connect (OSTI)

    Guler, N.; Fersch, R. G.; Kuhn, S. E.; Bosted, P.; Griffioen, K. A.; Keith, C.; Minehart, R.; Prok, Y.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A.; Briscoe, W. J.; Brooks, W. K.; Bltmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crabb, D.; Crede, V.; D'Angelo, A.; Dashyan, N.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Alaoui, A. El; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Forest, T. A.; Garillon, B.; Garon, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Golovatch, E.; Gothe, R. W.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Joosten, S.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Livingston, K.; Lu, H. Y.; Mayer, M.; MacGregor, I. J. D.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Movsisyan, A.; Munoz Camacho, C.; Nadel-Turonski, P.; Net, L. A.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabati, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Simonyan, A.; Skorodumina, Iu.; Sokhan, D.; Sparveris, N.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Ungaro, M.; Voutier, E.; Walford, N. K.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

    2015-11-02

    In this study, we present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron (15ND3) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry Ad1 and the polarized structure function gd1 were extracted over a wide kinematic range (0.05 GeV2 < Q2 < 5 GeV2 and 0.9 GeV < W < 3 GeV). We use an unfolding procedure and a parametrization of the corresponding proton results to extract from these data the polarized structure functions An1 and g1n of the (bound) neutron, which are so far unknown in the resonance region, W < 2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x, a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the Operator Product Expansion.

  20. 2014-05-08 Issuance: Energy Efficiency Improvements in ANSI/ASHRAE...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Improvements in ANSIASHRAEIES Standard 90.1-2013; Preliminary Determination 2014-05-08 Issuance: Energy Efficiency Improvements in ANSIASHRAEIES Standard 90.1-2013; ...

  1. CX-011578: Categorical Exclusion Determination | Department of...

    Office of Environmental Management (EM)

    CX-011578: Categorical Exclusion Determination Off-gas Treatment: Evaluation of Nano-structured Sorbents for Selective Removal of Contaminants CX(s) Applied: B3.6 Date: 11132013 ...

  2. CX-100101: Categorical Exclusion Determination | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    CX-100101: Categorical Exclusion Determination Laufer Wind Group NWTC Structure Lighting Tests; NREL Tracking No. 13-014 Award Number: DE-AC36-08GO28308 CX(s) Applied: A9, B1.31, ...

  3. Categorical Exclusion Determinations: Illinois | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Illinois Categorical Exclusion Determinations: Illinois Location Categorical Exclusion Determinations issued for actions in Illinois. DOCUMENTS AVAILABLE FOR DOWNLOAD July 20, 2016 CX-100656 Categorical Exclusion Determination Improving reliability and reducing cost in CdTe photovoltaics via grain boundary engineering Award Number: DE-EE0007545 CX(s) Applied: A9, B3.6 Solar Energy Technologies Office Date: 7/12/2016 Location(s): IL Office(s): Golden Field Office April 6, 2016 CX-100589

  4. Ergonomic Improvements for Foundries

    SciTech Connect (OSTI)

    Frank Peters; Patrick Patterson

    2002-06-18

    The goal of this project was to make improvements to the production systems of the steel casting industry through ergonomic improvements. Because of the wide variety of products, the wide range of product sizes, and the relatively small quantities of any particular product, manual operations remain a vital part of the production systems of the steel casting companies. Ergonomic improvements will assist the operators to more efficiently and consistently produce quality products.

  5. STRUCtural Simulator

    Energy Science and Technology Software Center (OSTI)

    2004-07-01

    STRUC-ANL is a derivative of the FLUSTR-ANL finite element code. It contains only the structural capabilities of the original fluid-structural FLUSTR code.

  6. Structural Materials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Structural Materials Development enables advanced technologies through the discovery, development, and demonstration of cost-effective advanced structural materials for use in ...

  7. Yellow fluorescent protein phiYFPv (Phialidium): structure and structure-based mutagenesis

    SciTech Connect (OSTI)

    Pletneva, Nadya V.; Pletnev, Vladimir Z. Souslova, Ekaterina; Chudakov, Dmitry M.; Lukyanov, Sergey; Martynov, Vladimir I.; Arhipova, Svetlena; Artemyev, Igor; Wlodawer, Alexander; Dauter, Zbigniew; Pletnev, Sergei

    2013-06-01

    The yellow fluorescent protein phiYFPv with improved folding has been developed from the spectrally identical wild-type phiYFP found in the marine jellyfish Phialidium. The yellow fluorescent protein phiYFPv (λ{sub em}{sup max} ≃ 537 nm) with improved folding has been developed from the spectrally identical wild-type phiYFP found in the marine jellyfish Phialidium. The latter fluorescent protein is one of only two known cases of naturally occurring proteins that exhibit emission spectra in the yellow–orange range (535–555 nm). Here, the crystal structure of phiYFPv has been determined at 2.05 Å resolution. The ‘yellow’ chromophore formed from the sequence triad Thr65-Tyr66-Gly67 adopts the bicyclic structure typical of fluorophores emitting in the green spectral range. It was demonstrated that perfect antiparallel π-stacking of chromophore Tyr66 and the proximal Tyr203, as well as Val205, facing the chromophore phenolic ring are chiefly responsible for the observed yellow emission of phiYFPv at 537 nm. Structure-based site-directed mutagenesis has been used to identify the key functional residues in the chromophore environment. The obtained results have been utilized to improve the properties of phiYFPv and its homologous monomeric biomarker tagYFP.

  8. Structure and yarn sensor for fabric

    DOE Patents [OSTI]

    Mee, D.K.; Allgood, G.O.; Mooney, L.R.; Duncan, M.G.; Turner, J.C.; Treece, D.A.

    1998-10-20

    A structure and yarn sensor for fabric directly determines pick density in a fabric thereby allowing fabric length and velocity to be calculated from a count of the picks made by the sensor over known time intervals. The structure and yarn sensor is also capable of detecting full length woven defects and fabric. As a result, an inexpensive on-line pick (or course) density measurement can be performed which allows a loom or knitting machine to be adjusted by either manual or automatic means to maintain closer fiber density tolerances. Such a sensor apparatus dramatically reduces fabric production costs and significantly improves fabric consistency and quality for woven or knitted fabric. 13 figs.

  9. Method and system for improved resolution of a compensated calorimeter detector

    DOE Patents [OSTI]

    Dawson, John W.

    1991-01-01

    An improved method and system for a depleted uranium calorimeter detector used in high energy physics experiments. In a depleted uranium calorimeter detector, the energy of a particle entering the calorimeter detector is determined and the output response of the calorimeter detector is compensated so that the ratio of the integrated response of the calorimeter detector from a lepton to the integrated response of the calorimeter detector from a hadron of the same energy as the lepton is approximately equal to 1. In the present invention, the energy of a particle entering the calorimeter detector is determined as a function of time and the hadron content of the response of the calorimeter detector is inferred based upon the time structure of the energy pulse measured by the calorimeter detector. The energy measurement can be corrected based on the inference of the hadron content whereby the resolution of the calorimeter can be improved.

  10. Categorical Exclusion Determinations: Nebraska | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Nebraska Categorical Exclusion Determinations: Nebraska Location Categorical Exclusion Determinations issued for actions in Nebraska. DOCUMENTS AVAILABLE FOR DOWNLOAD June 2, 2015 CX-013920: Categorical Exclusion Determination Box Butte-Chadron 115 Kilovolt Transmission Line Structure Replacement Project, Dawes County, CO CX(s) Applied: B1.3 Date: 06/02/2015 Location(s): Nebraska Offices(s): Western Area Power Administration-Rocky Mountain Region January 29, 2015 CX-013921: Categorical Exclusion

  11. Categorical Exclusion Determinations: Utah | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Utah Categorical Exclusion Determinations: Utah Location Categorical Exclusion Determinations issued for actions in Utah. DOCUMENTS AVAILABLE FOR DOWNLOAD March 18, 2016 CX-100576 Categorical Exclusion Determination Structurally Controlled Geothermal Systems in the Eastern Great Basin Extensional Regime, Utah Award Number: DE-EE0006732 CX(s) Applied: A9, B3.1, B3.6 Geothermal Technologies Office Date: 03/18/2016 Location(s): UT Office(s): Golden Field Office October 23, 2015 CX-014392:

  12. Improved solid aerosol generator

    DOE Patents [OSTI]

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  13. Improved wire chamber

    DOE Patents [OSTI]

    Atac, M.

    1987-05-12

    An improved gas mixture for use with proportional counter devices, such as Geiger-Mueller tubes and drift chambers. The improved gas mixture provides a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor. 2 figs.

  14. Method for improving instrument response

    DOE Patents [OSTI]

    Hahn, David W.; Hencken, Kenneth R.; Johnsen, Howard A.; Flower, William L.

    2000-01-01

    This invention pertains generally to a method for improving the accuracy of particle analysis under conditions of discrete particle loading and particularly to a method for improving signal-to-noise ratio and instrument response in laser spark spectroscopic analysis of particulate emissions. Under conditions of low particle density loading (particles/m.sup.3) resulting from low overall metal concentrations and/or large particle size uniform sampling can not be guaranteed. The present invention discloses a technique for separating laser sparks that arise from sample particles from those that do not; that is, a process for systematically "gating" the instrument response arising from "sampled" particles from those responses which do not, is dislosed as a solution to his problem. The disclosed approach is based on random sampling combined with a conditional analysis of each pulse. A threshold value is determined for the ratio of the intensity of a spectral line for a given element to a baseline region. If the threshold value is exceeded, the pulse is classified as a "hit" and that data is collected and an average spectrum is generated from an arithmetic average of "hits". The true metal concentration is determined from the averaged spectrum.

  15. Investigation of the La{sub 2}O{sub 3}–Nb{sub 2}O{sub 5}–WO{sub 3} ternary phase diagram: Isolation and crystal structure determination of the original La{sub 3}NbWO{sub 10} material

    SciTech Connect (OSTI)

    Vu, T.D.; Barre, M.; Adil, K.; Jouanneaux, A.; Suard, E.; Goutenoire, F.

    2015-09-15

    In the course of the exploration of the La{sub 2}O{sub 3}–WO{sub 3}–Nb{sub 2}O{sub 5} ternary phase diagram, a new compound with the formula La{sub 3}NbWO{sub 10} was discovered. Its structure was determined from a combination of powder X-ray and neutron diffraction data. It crystallizes in the tetragonal space group P4{sub 2}/nmc (no. 137) with the lattice parameters: a=10.0807(1) Å; c=12.5540(1) Å. The structure is built up from infinite ribbons of octahedra (W/Nb)O{sub 5} which are perpendicular to each other, lanthanum ions being distributed around these ribbons. The electrical properties of this compound were investigated on sintered pellets by means of complex impedance spectroscopy. - Graphical abstract: Projection along the c-axis of cationic and anionic positions of a La{sub 3}NbWO{sub 10} unit cell. - Highlights: • The structure of La{sub 3}NbWO{sub 10} was resolved from the XRD and ND data. • The structure was described in many ways. • The ionic conduction property was studied.

  16. Solar Forecast Improvement Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    For the Solar Forecast Improvement Project (SFIP), the Earth System Research Laboratory (ESRL) is partnering with the National Center for Atmospheric Research (NCAR) and IBM to develop more...

  17. Thin dielectric film thickness determination by advanced transmission electron microscopy

    SciTech Connect (OSTI)

    Diebold, A.C.; Foran, B.; Kisielowski, C.; Muller, D.; Pennycook, S.; Principe, E.; Stemmer, S.

    2003-09-01

    High Resolution Transmission Electron Microscopy (HR-TEM) has been used as the ultimate method of thickness measurement for thin films. The appearance of phase contrast interference patterns in HR-TEM images has long been confused as the appearance of a crystal lattice by non-specialists. Relatively easy to interpret crystal lattice images are now directly observed with the introduction of annular dark field detectors for scanning TEM (STEM). With the recent development of reliable lattice image processing software that creates crystal structure images from phase contrast data, HR-TEM can also provide crystal lattice images. The resolution of both methods was steadily improved reaching now into the sub Angstrom region. Improvements in electron lens and image analysis software are increasing the spatial resolution of both methods. Optimum resolution for STEM requires that the probe beam be highly localized. In STEM, beam localization is enhanced by selection of the correct aperture. When STEM measurement is done using a highly localized probe beam, HR-TEM and STEM measurement of the thickness of silicon oxynitride films agree within experimental error. In this paper, the optimum conditions for HR-TEM and STEM measurement are discussed along with a method for repeatable film thickness determination. The impact of sample thickness is also discussed. The key result in this paper is the proposal of a reproducible method for film thickness determination.

  18. Improving Meningococcal Vaccines

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Energy Improving Manufacturing through Technology and Innovation Improving Manufacturing through Technology and Innovation June 20, 2016 - 11:12am Addthis Find out how advanced technologies developed by our latest institute will make U.S. manufacturing more productive, energy efficient and competitive. | Advanced Manufacturing Office video. Dr. Ernest Moniz Dr. Ernest Moniz Secretary of Energy KEY FACTS Since February 2010, the U.S. manufacturing sector has added more than 800,000 jobs.

  19. Infrastructure Improvements - SRSCRO

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Infrastructure Improvements As the designated Community Reuse Organization for the Department of Energy's (DOE) Savannah River Site (SRS), our 22-member citizen-led Board of Directors has undertaken a study to point out the critical need for improving the deteriorating infrastructure at SRS. Priority attention needs to be made now to maximize SRS contributions and potential in the years ahead. SRS has all the assets required in people, land, expertise and community support to continue to play a

  20. Improving Entrainment Rate Parameterization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Entrainment Rate Parameterization For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Parameterization of entrainment rate is critical for improving representation of cloud- and convection-related processes in climate models; however, much remains unclear. This work seeks to improve understanding and parameterization of entrainment rate by use of aircraft observations and large-eddy simulations of shallow cumulus clouds over

  1. Method For Determining And Modifying Protein/Peptide Solubilty

    DOE Patents [OSTI]

    Waldo, Geoffrey S.

    2005-03-15

    A solubility reporter for measuring a protein's solubility in vivo or in vitro is described. The reporter, which can be used in a single living cell, gives a specific signal suitable for determining whether the cell bears a soluble version of the protein of interest. A pool of random mutants of an arbitrary protein, generated using error-prone in vitro recombination, may also be screened for more soluble versions using the reporter, and these versions may be recombined to yield variants having further-enhanced solubility. The method of the present invention includes "irrational" (random mutagenesis) methods, which do not require a priori knowledge of the three-dimensional structure of the protein of interest. Multiple sequences of mutation/genetic recombination and selection for improved solubility are demonstrated to yield versions of the protein which display enhanced solubility.

  2. Structural Genomics of Protein Phosphatases

    SciTech Connect (OSTI)

    Almo,S.; Bonanno, J.; Sauder, J.; Emtage, S.; Dilorenzo, T.; Malashkevich, V.; Wasserman, S.; Swaminathan, S.; Eswaramoorthy, S.; et al

    2007-01-01

    The New York SGX Research Center for Structural Genomics (NYSGXRC) of the NIGMS Protein Structure Initiative (PSI) has applied its high-throughput X-ray crystallographic structure determination platform to systematic studies of all human protein phosphatases and protein phosphatases from biomedically-relevant pathogens. To date, the NYSGXRC has determined structures of 21 distinct protein phosphatases: 14 from human, 2 from mouse, 2 from the pathogen Toxoplasma gondii, 1 from Trypanosoma brucei, the parasite responsible for African sleeping sickness, and 2 from the principal mosquito vector of malaria in Africa, Anopheles gambiae. These structures provide insights into both normal and pathophysiologic processes, including transcriptional regulation, regulation of major signaling pathways, neural development, and type 1 diabetes. In conjunction with the contributions of other international structural genomics consortia, these efforts promise to provide an unprecedented database and materials repository for structure-guided experimental and computational discovery of inhibitors for all classes of protein phosphatases.

  3. Improved Flow-Field Structures for Direct Methanol Fuel Cells

    SciTech Connect (OSTI)

    Gurau, Bogdan

    2013-05-31

    The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

  4. Method and structure for an improved data reformatting procedure...

    Office of Scientific and Technical Information (OSTI)

    memory in which a low-level mechanism is executed to signal, in a sequence of instructions generated at a higher level, that at least a portion of a contiguous area of memory is ...

  5. Sensor 17 Thermal Isolation Mounting Structure (TIMS) Design Improvements

    SciTech Connect (OSTI)

    Enstrom, K.

    2015-09-04

    The SENSOR 17 thermographic camera weighs approximately 0.5lbs, has a fundamental mode of 167 Hz, and experiences 0.75W of heat leakage in through the TIMS. The configuration, shown in Figure 1, is comprised of four 300 Series SST washers paired in tandem with P.E.I (Ultem 100) washers. The SENSOR 17 sensor is mounted to a 300 series stainless plate with A-shaped arms. The Plate can be assumed to be at ambient temperatures (≈293K) and the I.R. Mount needs to be cooled to 45K. It is attached to the tip of a cryocooler by a ‘cold strap’ and is assumed to be at the temperature of the cold-strap (≈45K). During flights SENSOR 17 experiences excitations at frequencies centered around 10-30Hz, 60Hz, and 120Hz from the aircraft flight environment. The temporal progression described below depicts the 1st Modal shape at the systems resonant frequency. This simulation indicates Modal articulation will cause a pitch rate of the camera with respect to the body axis of the airplane. This articulation shows up as flutter in the camera.

  6. Method for improving performance of irradiated structural materials

    DOE Patents [OSTI]

    Megusar, Janez; Harling, Otto K.; Grant, Nicholas J.

    1989-01-01

    Method for extending service life of nuclear reactor components prepared from ductile, high strength crystalline alloys obtained by devitrification of metallic glasses. Two variations of the method are described: (1) cycling the temperature of the nuclear reactor between the operating temperature which leads to irradiation damage and a l The U.S. Government has rights in this invention by virtue of Department of Energy, Office of Fusion Energy, Grant No. DE-AC02-78ER-10107.

  7. Structural Testing at the NWTC Helps Improve Blade Design and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Biaxial fatigue test of an MHI Wind Power Americas, Inc. turbine blade at the NWTC. Photo ... National Wind Technology Center (NWTC) has tested more than 150 wind turbine blades. ...

  8. Mesh Quality Improvement Toolkit

    Energy Science and Technology Software Center (OSTI)

    2002-11-15

    MESQUITE is a linkable software library to be used by simulation and mesh generation tools to improve the quality of meshes. Mesh quality is improved by node movement and/or local topological modifications. Various aspects of mesh quality such as smoothness, element shape, size, and orientation are controlled by choosing the appropriate mesh qualtiy metric, and objective function tempate, and a numerical optimization solver to optimize the quality of meshes, MESQUITE uses the TSTT mesh interfacemore » specification to provide an interoperable toolkit that can be used by applications which adopt the standard. A flexible code design makes it easy for meshing researchers to add additional mesh quality metrics, templates, and solvers to develop new quality improvement algorithms by making use of the MESQUITE infrastructure.« less

  9. Improved limited discrepancy search

    SciTech Connect (OSTI)

    Korf, R.E.

    1996-12-31

    We present an improvement to Harvey and Ginsberg`s limited discrepancy search algorithm, which eliminates much of the redundancy in the original, by generating each path from the root to the maximum search depth only once. For a complete binary tree of depth d this reduces the asymptotic complexity from O(d+2/2 2{sup d}) to O(2{sup d}). The savings is much less in a partial tree search, or in a heavily pruned tree. The overhead of the improved algorithm on a complete binary tree is only a factor of b/(b - 1) compared to depth-first search. While this constant factor is greater on a heavily pruned tree, this improvement makes limited discrepancy search a viable alternative to depth-first search, whenever the entire tree may not be searched. Finally, we present both positive and negative empirical results on the utility of limited discrepancy search, for the problem of number partitioning.

  10. Abuse Tolerance Improvements

    SciTech Connect (OSTI)

    Orendorff, Christopher J.; Nagasubramanian, Ganesan; Fenton, Kyle R.; Allcorn, Eric

    2015-10-01

    As lithium-ion battery technologies mature, the size and energy of these systems continues to increase (> 50 kWh for EVs); making safety and reliability of these high energy systems increasingly important. While most material advances for lithium-ion chemistries are directed toward improving cell performance (capacity, energy, cycle life, etc.), there are a variety of materials advancements that can be made to improve lithium-ion battery safety. Issues including energetic thermal runaway, electrolyte decomposition and flammability, anode SEI stability, and cell-level abuse tolerance continue to be critical safety concerns. This report highlights work with our collaborators to develop advanced materials to improve lithium-ion battery safety and abuse tolerance and to perform cell-level characterization of new materials.