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Sample records for core ii fragmentation

  1. A discrete neutral transition-metal citrate cubane with an M₄O₄ core; coordinative versatility of the [M(II)₄(citrate)₄]⁸⁻ fragment.

    Science.gov (United States)

    Falvello, Larry R; Forcén-Vázquez, Elena; Palacio, Fernando; Sanz, Sergio; Tomás, Milagros

    2014-07-28

    The neutral cluster [Mn(II)8(citrate)4(H2O)18] is formed by the [M4(citrate)4](8-) fragment, with an Mn4O4 cubane core, which bonds four peripheral aquomanganese units--two [Mn(H2O)4](2+) and two [Mn(H2O)5](2+)--through a total of six metal-ligand bonds, giving a discrete neutral compound. The compound presents a unique coordination mode in which the citrate cubane acts as a chelate to each of the two peripheral [Mn(H2O)4](2+) (tetra-aquo) units. A detailed analysis of the central and peripheral geometries is given in terms of the tetrahedral distortions of key structural features. A reversible dehydration-rehydration process has been observed in a polycrystalline sample of the complex, whose structure lacks pores or channels.

  2. Fragmentation of massive dense cores down to ≲ 1000 AU: Relation between fragmentation and density structure

    Energy Technology Data Exchange (ETDEWEB)

    Palau, Aina; Girart, Josep M. [Institut de Ciències de l' Espai (CSIC-IEEC), Campus UAB-Facultat de Ciències, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Estalella, Robert [Departament d' Astronomia i Meteorologia (IEEC-UB), Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès, 1, E-08028 Barcelona (Spain); Fuente, Asunción [Observatorio Astronómico Nacional, P.O. Box 112, E-28803 Alcalá de Henares, Madrid (Spain); Fontani, Francesco; Sánchez-Monge, Álvaro [Osservatorio Astrofisico di Arcetri, INAF, Lago E. Fermi 5, I-50125 Firenze (Italy); Commerçon, Benoit; Hennebelle, Patrick [Laboratoire de Radioastronomie, UMR CNRS 8112, École Normale Supérieure et Observatoire de Paris, 24 rue Lhomond, F-75231 Paris Cedex 05 (France); Busquet, Gemma [INAF-Istituto di Astrofisica e Planetologia Spaziali, Area di Recerca di Tor Vergata, Via Fosso Cavaliere 100, I-00133 Roma (Italy); Bontemps, Sylvain [Université de Bordeaux, LAB, UMR 5804, F-33270 Floirac (France); Zapata, Luis A. [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, P.O. Box 3-72, 58090 Morelia, Michoacán (Mexico); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Di Francesco, James, E-mail: palau@ieec.uab.es [Department of Physics and Astronomy, University of Victoria, P.O. Box 355, STN CSC, Victoria, BC, V8W 3P6 (Canada)

    2014-04-10

    In order to shed light on the main physical processes controlling fragmentation of massive dense cores, we present a uniform study of the density structure of 19 massive dense cores, selected to be at similar evolutionary stages, for which their relative fragmentation level was assessed in a previous work. We inferred the density structure of the 19 cores through a simultaneous fit of the radial intensity profiles at 450 and 850 μm (or 1.2 mm in two cases) and the spectral energy distribution, assuming spherical symmetry and that the density and temperature of the cores decrease with radius following power-laws. Even though the estimated fragmentation level is strictly speaking a lower limit, its relative value is significant and several trends could be explored with our data. We find a weak (inverse) trend of fragmentation level and density power-law index, with steeper density profiles tending to show lower fragmentation, and vice versa. In addition, we find a trend of fragmentation increasing with density within a given radius, which arises from a combination of flat density profile and high central density and is consistent with Jeans fragmentation. We considered the effects of rotational-to-gravitational energy ratio, non-thermal velocity dispersion, and turbulence mode on the density structure of the cores, and found that compressive turbulence seems to yield higher central densities. Finally, a possible explanation for the origin of cores with concentrated density profiles, which are the cores showing no fragmentation, could be related with a strong magnetic field, consistent with the outcome of radiation magnetohydrodynamic simulations.

  3. DR 21(OH): A HIGHLY FRAGMENTED, MAGNETIZED, TURBULENT DENSE CORE

    Energy Technology Data Exchange (ETDEWEB)

    Girart, J. M.; Frau, P. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, C5p 2, E-08193 Bellaterra, Catalonia (Spain); Zhang, Q. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Koch, P. M.; Tang, Y.-W.; Lai, S.-P.; Ho, P. T. P. [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Qiu, K., E-mail: girart@ice.cat [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2013-07-20

    We present high angular resolution observations of the massive star-forming core DR21(OH) at 880 {mu}m using the Submillimeter Array (SMA). The dense core exhibits an overall velocity gradient in a Keplerian-like pattern, which breaks at the center of the core where SMA 6 and SMA 7 are located. The dust polarization shows a complex magnetic field, compatible with a toroidal configuration. This is in contrast with the large, parsec-scale filament that surrounds the core, where there is a smooth magnetic field. The total magnetic field strengths in the filament and in the core are 0.9 and 2.1 mG, respectively. We found evidence of magnetic field diffusion at the core scales, far beyond the expected value for ambipolar diffusion. It is possible that the diffusion arises from fast magnetic reconnection in the presence of turbulence. The dynamics of the DR 21(OH) core appear to be controlled energetically in equal parts by the magnetic field, magnetohydrodynamic turbulence, and the angular momentum. The effect of the angular momentum (this is a fast rotating core) is probably causing the observed toroidal field configuration. Yet, gravitation overwhelms all the forces, making this a clear supercritical core with a mass-to-flux ratio of {approx_equal} 6 times the critical value. However, simulations show that this is not enough for the high level of fragmentation observed at 1000 AU scales. Thus, rotation and outflow feedback are probably the main causes of the observed fragmentation.

  4. HIERARCHICAL GRAVITATIONAL FRAGMENTATION. I. COLLAPSING CORES WITHIN COLLAPSING CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Naranjo-Romero, Raúl; Vázquez-Semadeni, Enrique; Loughnane, Robert M. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Apdo. Postal 3-72, Morelia, Michoacán, 58089, México (Mexico)

    2015-11-20

    We investigate the Hierarchical Gravitational Fragmentation scenario through numerical simulations of the prestellar stages of the collapse of a marginally gravitationally unstable isothermal sphere immersed in a strongly gravitationally unstable, uniform background medium. The core developes a Bonnor–Ebert (BE)-like density profile, while at the time of singularity (the protostar) formation the envelope approaches a singular-isothermal-sphere (SIS)-like r{sup −2} density profile. However, these structures are never hydrostatic. In this case, the central flat region is characterized by an infall speed, while the envelope is characterized by a uniform speed. This implies that the hydrostatic SIS initial condition leading to Shu's classical inside-out solution is not expected to occur, and therefore neither should the inside-out solution. Instead, the solution collapses from the outside-in, naturally explaining the observation of extended infall velocities. The core, defined by the radius at which it merges with the background, has a time-variable mass, and evolves along the locus of the ensemble of observed prestellar cores in a plot of M/M{sub BE} versus M, where M is the core's mass and M{sub BE} is the critical BE mass, spanning the range from the “stable” to the “unstable” regimes, even though it is collapsing at all times. We conclude that the presence of an unstable background allows a core to evolve dynamically from the time when it first appears, even when it resembles a pressure-confined, stable BE-sphere. The core can be thought of as a ram-pressure confined BE-sphere, with an increasing mass due to the accretion from the unstable background.

  5. Fragmentation patterns of doubly charged acrylonitrile molecule following carbon core ionization.

    Science.gov (United States)

    Itälä, E; Kukk, E; Ha, D T; Granroth, S; Caló, A; Partanen, L; Aksela, H; Aksela, S

    2009-09-21

    Dissociation of acrylonitrile into pairs of cations and neutral fragments following molecular core ionization was investigated using the photoelectron-photoion-photoion coincidence (PEPIPICO) technique. The fragment ion mass spectra were recorded in coincidence with the carbon 1s photoelectrons. Deuterated and (13)C-substituted samples were used for resolving fragment mass ambiguities. Slope analysis of the PEPIPICO patterns was used in determining the fragment separation sequences in case of multiparticle processes. The results show that there are several fragmentation channels producing a wide range of charged coincident fragments. The dynamics of the dominant fragmentation processes is investigated in detail.

  6. EARLY STAGES OF CLUSTER FORMATION: FRAGMENTATION OF MASSIVE DENSE CORES DOWN TO {approx}< 1000 AU

    Energy Technology Data Exchange (ETDEWEB)

    Palau, Aina; Girart, Josep M. [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB-Facultat de Ciencies, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Fuente, Asuncion [Observatorio Astronomico Nacional, P.O. Box 112, E-28803 Alcala de Henares, Madrid (Spain); Estalella, Robert [Departament d' Astronomia i Meteorologia (IEEC-UB), Institut de Ciencies del Cosmos, Universitat de Barcelona, Marti Franques, 1, E-08028 Barcelona (Spain); Ho, Paul T. P.; Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Sanchez-Monge, Alvaro; Fontani, Francesco; Cesaroni, Riccardo [Osservatorio Astrofisico di Arcetri, INAF, Lago E. Fermi 5, I-50125 Firenze (Italy); Busquet, Gemma [INAF-Istituto di Astrofisica e Planetologia Spaziali, Area di Recerca di Tor Vergata, Via Fosso Cavaliere 100, I-00133 Roma (Italy); Commercon, Benoit; Hennebelle, Patrick [Laboratoire de Radioastronomie, UMR CNRS 8112, Ecole Normale Superieure et Observatoire de Paris, 24 rue Lhomond, F-75231 Paris Cedex 05 (France); Boissier, Jeremie [Istituto di Radioastronomia, INAF, Via Gobetti 101, I-40129 Bologna (Italy); Zapata, Luis A., E-mail: palau@ieec.uab.es [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, P.O. Box 3-72, 58090 Morelia, Michoacan (Mexico)

    2013-01-10

    In order to study the fragmentation of massive dense cores, which constitute the cluster cradles, we observed the continuum at 1.3 mm and the CO (2-1) emission of four massive cores with the Plateau de Bure Interferometer in the most extended configuration. We detected dust condensations down to {approx}0.3 M {sub Sun} and separate millimeter sources down to 0.''4 or {approx}< 1000 AU, comparable to the sensitivities and separations reached in optical/infrared studies of clusters. The CO (2-1) high angular resolution images reveal high-velocity knots usually aligned with previously known outflow directions. This, in combination with additional cores from the literature observed at similar mass sensitivity and spatial resolution, allowed us to build a sample of 18 protoclusters with luminosities spanning three orders of magnitude. Among the 18 regions, {approx}30% show no signs of fragmentation, while 50% split up into {approx}> 4 millimeter sources. We compiled a list of properties for the 18 massive dense cores, such as bolometric luminosity, total mass, and mean density, and found no correlation of any of these parameters with the fragmentation level. In order to investigate the combined effects of the magnetic field, radiative feedback, and turbulence in the fragmentation process, we compared our observations to radiation magnetohydrodynamic simulations and found that the low-fragmented regions are reproduced well in the magnetized core case, while the highly fragmented regions are consistent with cores where turbulence dominates over the magnetic field. Overall, our study suggests that the fragmentation in massive dense cores could be determined by the initial magnetic field/turbulence balance in each particular core.

  7. THE FRAGMENTATION OF MAGNETIZED, MASSIVE STAR-FORMING CORES WITH RADIATIVE FEEDBACK

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Andrew T.; McKee, Christopher F. [Department of Physics, University of California, Berkeley, Berkeley, CA 94720 (United States); Cunningham, Andrew J. [Lawrence Livermore National Laboratory, P.O. Box 808, L-23, Livermore, CA 94550 (United States); Klein, Richard I. [Department of Astronomy, University of California, Berkeley, Berkeley, CA 94720 (United States); Krumholz, Mark R., E-mail: atmyers@berkeley.edu [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2013-04-01

    We present a set of three-dimensional, radiation-magnetohydrodynamic calculations of the gravitational collapse of massive (300 M{sub Sun }), star-forming molecular cloud cores. We show that the combined effects of magnetic fields and radiative feedback strongly suppress core fragmentation, leading to the production of single-star systems rather than small clusters. We find that the two processes are efficient at suppressing fragmentation in different regimes, with the feedback most effective in the dense, central region and the magnetic field most effective in more diffuse, outer regions. Thus, the combination of the two is much more effective at suppressing fragmentation than either one considered in isolation. Our work suggests that typical massive cores, which have mass-to-flux ratios of about 2 relative to critical, likely form a single-star system, but that cores with weaker fields may form a small star cluster. This result helps us understand why the observed relationship between the core mass function and the stellar initial mass function holds even for {approx}100 M{sub Sun} cores with many thermal Jeans masses of material. We also demonstrate that a {approx}40 AU Keplerian disk is able to form in our simulations, despite the braking effect caused by the strong magnetic field.

  8. The GBT 3mm Survey of Infall and Fragmentation of Dense Cores in Taurus

    Science.gov (United States)

    Seo, Youngmin; Goldsmith, Paul; Shirley, Yancy L.; Church, Sara; Frayer, David

    2018-01-01

    We present preliminary results of the infall and fragmentation survey toward a complete population of prestellar cores in Taurus that was carried out with the 16-element W-band focal plane array receiver (Argus) on the 100m Green Bank Telescope. The survey is designed take advantage of the 8.5” angular resolution and high sensitivity of Argus on the GBT to trace infall motions in HCN 1-0 & HCO+ 1-0 and find any evidence of fragmentation in N2H+ & NH2D within prestellar cores ranging in size from 0.05 pc to 0.0075 pc (1500 AU), which is a typical size scale of individual planetary systems. The scientific goal is to estimate the fraction of infall candidates from a complete population of prestellar cores and to understand internal velocity structure during the final gravitational collapse before forming stars. The survey started in the winter of 2016 and is to continue to the end of January 2018. So far, we observed 23 prestellar cores out of 65 targets in HCN 1-0 and HCO+ 1-0. We have so far found only two prestellar cores (L1495A-N, L1521D) out of 23 observed that show infall signatures, which is a fraction of infalling cores less than half of that reported by the previous surveys toward the bright, dense cores in various molecular clouds (Lee et al. 2004; Sohn et al. 2007). We also found that L1495A-N has a highly asymmetric infall motion which does not fit to a conventional model of dense core collapse, while L1521D has a slow infall motion similar to L1544.

  9. SMART core preliminary nuclear design-II

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Chan; Ji, Seong Kyun; Chang, Moon Hee

    1997-06-01

    Three loading patterns for 330 MWth SMART core are constructed for 25, 33 and 29 CRDMs, and one loading pattern for larger 69-FA core with 45 CRDMs is also constructed for comparison purpose. In this study, the core consists of 57 reduced height Korean Optimized Fuel Assemblies (KOFAs) developed by KAERI. The enrichment of fuel is 4.95 w/o. As a main burnable poison, 35% B-10 enriched B{sub 4}C-Al{sub 2}O{sub 3} shim is used. To control stuck rod worth, some gadolinia bearing fuel rods are used. The U-235 enrichment of the gadolinia bearing fuel rods is 1.8 w/o as used in KOFA. All patterns return cycle length of about 3 years. Three loading patterns except 25-CRDM pattern satisfy cold shutdown condition of keff {<=} 0.99 without soluble boron. These three patterns also satisfy the refueling condition of keff {<=} 0.95. In addition to the construction of loading pattern, an editing module of MASTER PPI files for rod power history generation is developed and rod power histories are generated for 29-CRDM loading pattern. Preliminary Fq design limit is suggested as 3.71 based on KOFA design experience. (author). 9 tabs., 45 figs., 16 refs.

  10. Coordination of dibensothiophenes and corannulenes to organometallic ruthenium (II) fragments

    Energy Technology Data Exchange (ETDEWEB)

    Vecchi, Paul Anthony [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    This dissertation contains five papers in the format required for journal publication which describe (in part) my research accomplishments as a graduate student at Iowa State University. This work can be broadly categorized as the binding of weakly-coordinating ligands to cationic organometallic ruthenium fragments, and consists of two main areas of study. Chapters 2-4 are investigations into factors that influence the binding of dibenzothiophenes to [Cp'Ru(CO)2(+ fragments, where Cp' = η5-C5H5 (Cp) and η5-C5Me5 (Cp*). Chapters 5 and 6 present the synthesis and structural characterization of complexes containing corannulene buckybowls that are η6-coordinated to [Cp*Ru(+ fragments. The first chapter contains a brief description of the difficulty in lowering sulfur levels in diesel fuel along with a review of corannulene derivatives and their metal complexes. After the final paper is a short summary of the work herein (Chapter 7). Each chapter is independent, and all equations, schemes, figures, tables, references, and appendices in this dissertation pertain only to the chapter in which they appear.

  11. Mg(II) binding by bovine prothrombin fragment 1 via equilibrium dialysis and the relative roles of Mg(II) and Ca(II) in blood coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Deerfield, D.W. 2d.; Olson, D.L.; Berkowitz, P.; Byrd, P.A.; Koehler, K.A.; Pedersen, L.G.; Hiskey, R.G.

    1987-03-25

    The first direct equilibrium dialysis titration of the blood coagulation protein bovine prothrombin fragment 1 with Mg(II) is presented. Fragment 1 has fewer thermodynamic binding sites for Mg(II) than Ca(II), less overall binding affinity, and significantly less cooperativity. Several nonlinear curve fitting models were tested for describing the binding of fragment 1 with Mg(II), Ca(II), and mixed metal binding data. The Mg(II) data is represented by essentially five equivalent, noninteracting sites; for Ca(II), a model with three tight, cooperative sites and four ''loose'', equal affinity, noninteracting sites provides the best model. Based on the reported equilibrium dialysis data and in conjunction with other experimental data, a model for the binding of Ca(II) and Mg(II) to bovine prothrombin fragment 1 is proposed. The key difference between the binding of these divalent ions is that Ca(II) apparently causes a specific conformational change reflected by the cooperativity observed in the Ca(II) titration. The binding of Ca(II) ions to the three tight, cooperative sites establishes a conformation that is essential for phospholipid X Ca(II) X protein binding. The filling of the loose sites with Ca(II) ions leads to charge reduction and subsequent phospholipid X Ca(II) X protein complex interaction. Binding of Mg(II) to bovine prothrombin fragment 1 does not yield a complex with the necessary phospholipid-binding conformation. However, Mg(II) is apparently capable of stabilizing the Ca(II) conformation as is observed in the mixed metal ion binding data and the synergism in thrombin formation.

  12. LMR core disassembly calculation using the VENUS-II code

    Energy Technology Data Exchange (ETDEWEB)

    Suk, S. D.; Lee, Y. B. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    In this study, core disassembly analysis in the sodium-voided core of the KALIMER were performed using the VENUS-II code for various reactivity insertion rates up to 100 $/s, which has been widely considered to be the upper limit of ramp rates due to fuel compaction. The VENUS-II code is a two-dimensional coupled neutronics-hydrodynamics program that calculates the dynamic behavior of an LMFR during a prompt critical excursion. Core disruptive accidents have been investigated at Korea Atomic Energy Research Institute(KAERI) as part of the work to demonstrate the inherent and ultimate safety of conceptual design of the Korea Advanced Liquid Metal Reactor(KALIMER), a pool-type sodium cooled prototype fast reactor that uses U-TRU-Zr metallic fuel. Results of previous scoping studies using a modified Bethe-Tait methods showed that the core disruptive power excursions are terminated without any significant pressure rise or energy release to threaten the integrity of the reactor system.This study is a continual to the previous scoping studies, analyzing core disruptive accidents in more detail using the VENUS-II code.

  13. Structural determination of the photosystem II core complex from spinach

    NARCIS (Netherlands)

    Irrgang, Klaus-D.; Boekema, Egbert J.; Vater, Joachim; Renger, Gernot

    1988-01-01

    A photosystem II core complex was purified with high yield from spinach by solubilization with β-dodecylmaltoside. The complex consisted of polypeptides with molecular mass 47, 43, 34, 31, 9 and 4 kDa and some minor components, as detected by silver-staining of polyacrylamide gels. There was no

  14. The type II collagen fragments Helix-II and CTX-II reveal different enzymatic pathways of human cartilage collagen degradation

    DEFF Research Database (Denmark)

    Charni-Ben Tabassi, N; Desmarais, S; Jensen, Anne-Christine Bay

    2008-01-01

    that they may be generated through different collagenolytic pathways. In this study we analyzed the release of Helix-II and CTX-II from human cartilage collagen by the proteinases reported to play a role in cartilage degradation. METHODS: In vitro, human articular cartilage extract was incubated with activated...... sections were then incubated for up to 84h in the presence or absence of E-64 and GM6001, inhibitors of cysteine proteases and MMPs, respectively. RESULTS: In vitro, Cats K, L and S generated large amount of Helix-II, but not CTX-II. Cat B generated CTX-II fragment, but destroyed Helix-II immunoreactivity...

  15. Structural Rearrangement upon Fragmentation of the Stability Core of the ALS-Linked Protein TDP-43.

    Science.gov (United States)

    Morgan, Brittany R; Zitzewitz, Jill A; Massi, Francesca

    2017-08-08

    Amyotrophic lateral sclerosis (ALS) is the most common adult degenerative motor neuron disease. Experimental evidence indicates a direct role of transactive-response DNA-binding protein 43 (TDP-43) in the pathology of ALS and other neurodegenerative diseases. TDP-43 has been identified as a major component of cytoplasmic inclusions in patients with sporadic ALS; however, the molecular basis of the disease mechanism is not yet fully understood. Fragmentation within the second RNA recognition motif (RRM2) of TDP-43 has been observed in patient tissues and may play a role in the formation of aggregates in disease. To determine the structural and dynamical changes resulting from the truncation that could lead to aggregation and toxicity, we performed molecular dynamics simulations of the full-length RRM2 domain (the stability core of TDP-43) and of a truncated variant (where residues 189-207 are deleted to mimic a site of cleavage within RRM2 found in ALS patients). Our simulations show heterogeneous structural reorganization and decreased stability of the truncated RRM2 domain compared to the full-length domain, consistent with previous experimental results. The decreased stability and structural reorganization in the truncated RRM2 result in a higher probability of protein-protein interactions through altered electrostatic surface charges and increased accessibility of hydrophobic residues (including the nuclear export sequence), providing a rationale for the increased cytoplasmic aggregation of RRM2 fragments seen in sporadic ALS patients. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. The etching property of the surface of CR-39 and the track core radius of fission fragment

    CERN Document Server

    Mineyama, D; Yamauchi, T; Oda, K; El-Rahman, A

    2002-01-01

    The etch pits of fission fragments in CR-39 detector have been observed carefully using an atomic force microscope (AFM) after extremely short chemical etching in stirred 6N KOH solution kept at 70degC. It was found that there existed a thin layer where the bulk etch rate is relativity from large the etch-pit growth curve for the etching duration between 10 and 1800 seconds. The track core radius of fission fragment was evaluated to be about 6 nm from the extrapolation of the growth curve in a thinner region. (author)

  17. Frequency dependent conductivity of vortex cores in type II superconductors

    Science.gov (United States)

    Hsu, Theodore C.

    1993-08-01

    Recent experiments by Karraï et al. probed vortices in YBa 2Cu 3O 7 at frequencies near the “minigap” between discrete core states, Δ 2/ EF. EF is the Fermi energy and Δ is the bulk energy gap. Here we calculate the conductivity, σ(ω), of vortices using a novel, microscopic description of single vortex dynamics based on the Bogoliubov-deGennes equations and self-consistency through the gap equation. It is applicable to the low temperature, clean, type II limit. An equation of motion for vortex cores valid at non-zero frequencies, including Magnus, drag, and pinning forces, is derived. The cyclotron resonance as well as structure at the minigap appear in σ(ω). The expected dipole transition between localized states is hidden because the vortex is a self-consistent potential. Unless translation invariance is broken, single particle properties are invisible to a long wavelength probe. Upon adding drag and pinning, dissipation near h̵hω≈Δ 2/ EF appears.

  18. Manganism and Parkinson's disease: Mn(II) and Zn(II) interaction with a 30-amino acid fragment.

    Science.gov (United States)

    Remelli, Maurizio; Peana, Massimiliano; Medici, Serenella; Ostrowska, Malgorzata; Gumienna-Kontecka, Elzbieta; Zoroddu, Maria Antonietta

    2016-03-28

    A protected 30-amino acid fragment, Acetyl-SPDEKHELMIQLQKLDYTVGFCGDGANDCG-Amide, Acetyl-Ser-Pro-Asp-Glu-Lys-His-Glu-Leu-Met-Ile-Gln-Leu-Gln-Lys-Leu-Asp-Tyr-Thr-Val-Gly-Phe-Cys-Gly-Asp-Gly-Ala-Asn-Asp-Cys-Gly-Amide, encompassing the sequence from residues 1164 to 1193 in the encoded protein from Parkinson's disease gene Park9 (YPk9), was studied for manganese and zinc binding. Manganese exposure is considered to be an environmental risk factor connected to PD and PD-like syndrome. Research into the genetic and environmental risk factors involved in disease susceptibility has recently uncovered a link existing between Park9 and manganese. It seems that manganese binding to Park9 (YPk9) protein is involved in the detoxification mechanism exerted by this protein against manganese toxicity. In this study, we used potentiometric, mono- and bi-dimensional (TOCSY, HSQC) NMR, EPR and ESI-MS measurements to analyze complex formation and metal binding sites in the peptide fragment. Presumably octahedral species, in which the Mn(II) ion was bound to oxygens of the carboxyl groups of Glu and Asp, and species where the involvement of sulfur from Cys and nitrogen from His residues, depending on the metal to ligand molar ratio, were detected for manganese coordination. Structural changes in the 30-amino acid fragment were triggered by Zn(II) interaction. A general decrease in the intensity of NMR signals was detected, suggesting the occurrence of chemical exchange among some coordinated species in an intermediate NMR timescale. The coordination may involve both S and N donor atoms from cysteine as well as histidine residues, together with O donor atoms from glutamic and aspartic residues.

  19. Ultrafast energy transfer within the photosystem II core complex.

    Science.gov (United States)

    Pan, Jie; Gelzinis, Andrius; Chorošajev, Vladimir; Vengris, Mikas; Senlik, S Seckin; Shen, Jian-Ren; Valkunas, Leonas; Abramavicius, Darius; Ogilvie, Jennifer P

    2017-06-14

    We report 2D electronic spectroscopy on the photosystem II core complex (PSII CC) at 77 K under different polarization conditions. A global analysis of the high time-resolution 2D data shows rapid, sub-100 fs energy transfer within the PSII CC. It also reveals the 2D spectral signatures of slower energy equilibration processes occurring on several to hundreds of picosecond time scales that are consistent with previous work. Using a recent structure-based model of the PSII CC [Y. Shibata, S. Nishi, K. Kawakami, J. R. Shen and T. Renger, J. Am. Chem. Soc., 2013, 135, 6903], we simulate the energy transfer in the PSII CC by calculating auxiliary time-resolved fluorescence spectra. We obtain the observed sub-100 fs evolution, even though the calculated electronic energy shows almost no dynamics at early times. On the other hand, the electronic-vibrational interaction energy increases considerably over the same time period. We conclude that interactions with vibrational degrees of freedom not only induce population transfer between the excitonic states in the PSII CC, but also reshape the energy landscape of the system. We suggest that the experimentally observed ultrafast energy transfer is a signature of excitonic-polaron formation.

  20. Investigation of Explosively Driven Fragmentation of Metals - Two Dimensional Fracture and Fragmentation of Metal Shells: Progress Report II

    Energy Technology Data Exchange (ETDEWEB)

    Grady, D

    2003-02-01

    High explosive enclosed by a metal case qualitatively describes an essential component of high energy systems of importance to the Department of Energy. Detonation of the high explosive causes intense transient pressure loading of the metal following arrival of normal or obliquely incident explosive detonation wave. Subsequent expansion and deformation of the metal case leads to eventual rupture and the opening of fractures and fissures. Details of the rupture process are critical to performance of the system. Consequently, it is essential that the material and kinematic issues governing the processes of dynamic loading and subsequent failure of an explosive-metal case component within a functioning system be adequately understood. Among the reasons are to quantify existing performance, characterize potential degradation of performance resulting from system aging, and optimizing or maintaining system performance through implementation of structural or material changes. The physical and engineering issues underlying this dynamic response and failure phenomena are not adequately understood. The purpose of the present program is to identify the key issues and develop theoretical, computational and experimental models needed to achieve a satisfactory theoretical and analysis framework for analysis of metal case failure in the explosive environment. Specific tasks within the present program include: (1) Models and theories currently being pursued based on physical principles of both the statistical fragmentation concepts of Mott and the energy-based concept of others show promise of providing the analytic and computational methodology capable of predicting explosion-induced fracture and fragmentation of metal components. Experimental studies initiated in the earlier effort offer promise to provide critical test data for validation. The present task shall involve the further refinement and development of the dynamic failure and fragmentation models and theories, and the

  1. Collapse and fragmentation of molecular cloud cores. 2: Collapse induced by stellar shock waves

    Science.gov (United States)

    Boss, Alan P.

    1995-01-01

    The standard scenario for low-mass star formation involves 'inside-out' collapse of a dense molecular cloud core following loss of magnetic field support through ambipolar diffusion. However, isotopic anomalies in presolar grains and meteoritical inclusions imply that the collapse of the presolar cloud may have been triggered by a stellar shock wave. This paper explores 'outside-in' collapse, that is, protostellar collapse initiated directly by the compression of quiescent dense cloud cores impacted by relatively slow stellar shock waves. A second-order accurate, gravitational hydrodynamics code has been used to study both the spherically symmetrical and three-dimensional evolution of initially centrally condensed, isothermal, self-gravitating, solar-mass cloud cores that are struck by stellar shock waves with velocities up to 25 km/s and postshock temperatures of 10 to 10,000 K. The models show that such mild shock waves do not completely shred and destroy the cloud, and that the dynamical ram pressure can compress the cloud to the verge of self-gravitational collapse. However, compression caused by a high postshock temperature is a considerably more effective means of inducing collapse. Shock-induced collapse produces high initial mass accretion rates (greater than 10(exp -4) solar mass/yr in a solar-mass cloud) that decline rapidly to much lower values, depending on the presence (approximately 10(exp -6) solar mass/yr) or absence (approximately 10(exp -8) to 10(exp -7) solar mass/yr) of an infinite reservoir of mass. Stellar mass accretion rates approximately 10(exp -7) solar mass/yr have been previously inferred from the luminosities of T Tauri stars; balanced mass accretion (stellar rate = envelope rate) at approximately 10(exp -7) solar mass/yr could then be possible if accretion occurs from a finite mass reservoir. Fluid tracers are used to determine what fraction of the stellar shock material is incorporated into the resulting protostellar object and disk

  2. Significance of pregnancy test false negative results due to elevated levels of β-core fragment hCG.

    Science.gov (United States)

    Johnson, Sarah; Eapen, Saji; Smith, Peter; Warren, Graham; Zinaman, Michael

    2017-01-01

    Very high levels of β-core fragment human chorionic gonadotrophin (βcf-hCG) are reported to potentially cause false negative results in point-of-care (POC)/over-the-counter (OTC) pregnancy tests. To investigate this further, women's daily early morning urine samples, collected prior to conception and during pregnancy, were analysed for intact, free β-, and βcf-hCG. The proportion of βcf-hCG was found to be related to that of hCG produced and in circulation. Therefore, best practice for accuracy testing of POC/OTC pregnancy tests would be to test devices against clinical samples containing high levels of βcf-hCG as well as standards spiked with biologically relevant ratios.

  3. Some comments to Cicero, De Natura Deorum II 37, 95-96: a fragment of Aristotle’s On Philosophy

    Directory of Open Access Journals (Sweden)

    Anton-Hermann Chroust

    1975-12-01

    Full Text Available A reconstruction of a likely theme in Aristotle’s On Philosophy with the help of its echo in Seneca, Dio Chrysostomus, Synesius and Psellus. Cicero’s, De Natura Deorum II 37, 95-96, might well be considered an authentic fragment of the Aristotelian On Philosophy.

  4. Kansas Vocational Agriculture Education. Basic Core Curriculum Project, Horticulture II.

    Science.gov (United States)

    Albracht, James, Ed.

    This second horticulture guide is one of a set of three designated as the basic core of instruction for horticulture programs in Kansas. Units of instruction are presented in eight sections: (1) Leadership, (2) Supervised Occupational Experience, (3) Plant Propagation, (4) Soil and Plant Growth Media, (5) Fertilizers, (6) Greenhouse, (7) Plant…

  5. Apparent climate-mediated loss and fragmentation of core habitat of the American pika in the Northern Sierra Nevada, California, USA

    Science.gov (United States)

    Joseph A. E. Stewart; David H. Wright; Katherine A. Heckman; Robert Guralnick

    2017-01-01

    Contemporary climate change has been widely documented as the apparent cause of range contraction at the edge of many species distributions but documentation of climate change as a cause of extirpation and fragmentation of the interior of a species' core habitat has been lacking. Here, we report the extirpation of the American pika (Ochotona princeps...

  6. Anchor side chains of short peptide fragments trigger ligand-exchange of class II MHC molecules.

    Directory of Open Access Journals (Sweden)

    Shashank Gupta

    Full Text Available Class II MHC molecules display peptides on the cell surface for the surveillance by CD4+ T cells. To ensure that these ligands accurately reflect the content of the intracellular MHC loading compartment, a complex processing pathway has evolved that delivers only stable peptide/MHC complexes to the surface. As additional safeguard, MHC molecules quickly acquire a 'non-receptive' state once they have lost their ligand. Here we show now that amino acid side chains of short peptides can bypass these safety mechanisms by triggering the reversible ligand-exchange. The catalytic activity of dipeptides such as Tyr-Arg was stereo-specific and could be enhanced by modifications addressing the conserved H-bond network near the P1 pocket of the MHC molecule. It affected both antigen-loading and ligand-release and strictly correlated with reported anchor preferences of P1, the specific target site for the catalytic side chain of the dipeptide. The effect was evident also in CD4+ T cell assays, where the allele-selective influence of the dipeptides translated into increased sensitivities of the antigen-specific immune response. Molecular dynamic calculations support the hypothesis that occupation of P1 prevents the 'closure' of the empty peptide binding site into the non-receptive state. During antigen-processing and -presentation P1 may therefore function as important "sensor" for peptide-load. While it regulates maturation and trafficking of the complex, on the cell surface, short protein fragments present in blood or lymph could utilize this mechanism to alter the ligand composition on antigen presenting cells in a catalytic way.

  7. Negative- and positive-ion fragmentation of core-excited formic-acid molecules studied with three- and four-ion coincidence spectroscopy

    Science.gov (United States)

    Strâhlman, Christian; Kivimäki, Antti; Richter, Robert; Sankari, Rami

    2017-08-01

    The negative-ion fragmentation of formic acid (HCOOH) is studied with negative- and positive-ion coincidence spectroscopy. We report four-body ionic fragmentation where up to three positive ions are collected in coincidence with one negative ion. We report yields for 21 three-body channels and five four-body channels. More than 80% of all negative-ion fragmentation involves production of O-, and it is dominated by complete dissociation of all molecular bonds. Negative-ion creation is most abundant at high-Rydberg resonances and just above the molecule's core-ionization potentials. The existence of four-body fragmentation channels evidences a strong charge redistribution in the molecule.

  8. Probing the picosecond kinetics of the photosystem II core complex in vivo

    NARCIS (Netherlands)

    Tian, L.; Farooq, S.; Amerongen, van H.

    2013-01-01

    Photosystems I (PSI) and II (PSII) are two major pigment–protein complexes of photosynthetic organisms that function in series to convert sunlight energy into chemical energy. We have studied the picosecond fluorescence behaviour of the core of both photosystems in vivo by using two Synechocystis

  9. Career Ladders and Core Curriculum in Human Services. Phase II Final Report.

    Science.gov (United States)

    Soong, Robert K.

    This portion of Phase II of the Social Service Aide Project, a program of exemplary education for the career development of paraprofessionals in social and/or human services, represented an attempt to broaden the career ladders developed during Phase I and to extend the core curriculum above and below the Associate in Arts degree. The scheme of…

  10. Double-Diels-Alder Approach to Maoecrystal V. Unexpected C-C Bond-Forming Fragmentations of the [2.2.2]-Bicyclic Core.

    Science.gov (United States)

    Smith, Brandon R; Njardarson, Jon T

    2017-10-06

    Synthetic studies toward maoecrystal V are reported. An oxidative dearomatization/Diels-Alder cascade to assemble the natural product carbocyclic core in one step is proposed. A facile electrocyclization is shown to suppress the intramolecular allene Diels-Alder pathway. This obstacle is alleviated via a stepwise approach with an allene equivalent to access the key cyclopentadiene-fused [2.2.2]-bicyclic core. Upon treatment with Lewis acid, the proposed intramolecular hetero-Diels-Alder reaction is cleanly and unexpectedly diverted either via C-C bond-forming fragmentation to the spiro-indene product (when R = OMe) or via elimination (when R = H).

  11. Palladium(II) complexes bearing di-(2-picolyl)amine functionalized chrysin fragments. An experimental and theoretical study

    Science.gov (United States)

    González-Montiel, Simplicio; Valdez-Calderón, Alejandro; Vásquez-Pérez, J. Manuel; Torres-Valencia, J. Martín; Martínez-Otero, Diego; López, Jorge A.; Cruz-Borbolla, Julián

    2017-10-01

    A new series of chrysin derivatives containing the di-(2-picolyl)amine (2a-d) moiety have been designed, synthesized, and treated with PdCl2·2CH3CN allowing the preparation of new cationic Palladium(II) complexes (3a-d). Solution-phase studies by 1H NMR spectroscopy of 3a-d revealed that the protons of the methylene groups of the di(2-picolyl)amine fragment are diasterotopic. GIAO/DFT studies were performed to predict the molecular structures of 3a-d by comparing the experimental and theoretical 1H-NMR chemical shifts. The molecular structure of 3c was determined by X-ray crystallographic analysis revealing that di-(2-picolyl)amine fragment is coordinated to the palladium center in a κ3-N,N,N-tridentate fashion in an overall square-planar geometry completed with a chloride atom.

  12. Effects of Site-Mutations Within the 22 kDa No-Core Fragment of the Vip3Aa11 Insecticidal Toxin of Bacillus thuringiensis.

    Science.gov (United States)

    Liu, Ming; Liu, Rongmei; Luo, Guoxing; Li, Haitao; Gao, Jiguo

    2017-05-01

    Bacillus thuringiensis vegetative insecticidal proteins (VIPs) are not homologous to other known Cry proteins, and they act against lepidopteran larvae via a unique process. All reported studies on the mode of action of Vip3 proteins have been performed on the Vip3A family, mostly on the Vip3Aa subfamily. Vip3Aa proteins are activated by midgut proteases, and they cross the peritrophic membrane and bind specific proteins in apical membrane epithelial midgut cells, which results in pore formation and, eventually, death to the insects. Some studies of trypsin-activated protein (core fragment) and the full-length protein show differences in mortality on the same insect species. The N-terminus of Vip3A proteins is responsible for the translocation of the protein across the cell membrane. To determine whether the N-terminus of Vip3Aa11 proteins contribute to insecticidal activity, we exchanged Vip3Aa11 residues with Vip3Aa39 no-core fragment residues using site-directed mutagenesis. Bioassays showed that the toxicity of S9N, S193T, and S194L mutants displayed approximately one- and twofold increases in toxicity against Helicoverpa armigera. Mutant protein R115H demonstrated a threefold decrease in toxicity. This work serves as a guideline for the study of the Vip3Aa11 no-core fragment protein insecticidal mechanism.

  13. Analytical approach for type-II semiconductor spherical core-shell quantum dots heterostructures with wide band gaps

    OpenAIRE

    Cheche, Tiberius O.; Chang, Yia-Chung

    2013-01-01

    A one-band model within the effective mass approximation is adopted to characterize the energy structure and oscillator strength of type-II semiconductor spherical core-shell quantum dots. The heteroepitaxial strain of the core-shell heterostructure is modeled by the elastic continuum approach. The model is applied to ZnTe/ZnSe core-shell, a wide band gap type-II heterostructure. The simulated absorption spectra are in fair agreement with available experimental results.

  14. Macrocyclic effects upon isomeric Cu II Mii and Mii Cu II cores ...

    Indian Academy of Sciences (India)

    The macrocycles have dissimilar N(amine)2O2 and N(imine)2O2 metal-binding sites sharing the phenolic oxygens. The reaction of the mononuclear CuII precursors, [Cu(L2;2)], [Cu(L2;2)] and [Cu(L2;2)], with a MII perchlorate and a MII acetate salt formed (acetato)MII CuII complexes:[CoCu(L2;2)(AcO)]ClO4 0 5H2O] (1), ...

  15. The Core Collapse Supernova Rate from the SDSS-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Matt; Cinabro, David; Dilday, Ben; Galbany, Lluis; Gupta, Ravi R.; Kessler, R.; Marriner, John; Nichol, Robert C.; Richmond, Michael; Schneider, Donald P.; Sollerman, Jesper

    2014-08-26

    We use the Sloan Digital Sky Survey II Supernova Survey (SDSS-II SNS) data to measure the volumetric core collapse supernova (CCSN) rate in the redshift range (0.03 < z < 0.09). Using a sample of 89 CCSN, we find a volume-averaged rate of 1.06 ± 0.19 × 10(–)(4)((h/0.7)(3)/(yr Mpc(3))) at a mean redshift of 0.072 ± 0.009. We measure the CCSN luminosity function from the data and consider the implications on the star formation history.

  16. Features of the Energy Balance and Fragmentation Mechanisms at Spontaneous Failure of Class I and Class II Rocks

    Science.gov (United States)

    Tarasov, Boris G.; Stacey, Thomas R.

    2017-10-01

    Practically, all types of rockbursts are accompanied by release of seismic energy, rock bulking (due to fracturing and fragmentation), and ejection of fragmented rocks in the opening. Principles of the energy redistribution during rockbursts in some regards are comparable with principles taking place at spontaneous failure of rock specimens under compression in loading systems. In both cases, the total potential elastic energy accumulated in the failing material and in the loading system (or surrounding rock mass) is converted into such components of dynamic energy as rupture energy, seismic energy (or energy of oscillation of the loading system due to dynamic energy release), and kinetic energy of flying fragments of the failed material. It is known that spontaneous failure takes place at the post-peak failure stage and is determined by the ratio between stiffness of the loading system and stiffness (or brittleness) of the failing material. However, principles of the energy redistribution between different components of the energy balance are still unclear. The paper discusses results of laboratory experiments conducted on rock specimens of different brittleness (including Class I and Class II) that were loaded in testing machines of different loading stiffness. The most brittle of the tested specimens are represented by quartzite and glass, and the less brittle by salt. The loading stiffness of testing machines used in experiments was variable within three decimal orders of magnitude. The specific variations of the dynamic energy balance depending on rock brittleness and loading stiffness were established. The role of each portion of elastic energy stemming from the specimen and from the loading system in determining the dynamic energy balance and fragmentation mechanisms operating at spontaneous failure is analysed. The results obtained contribute to the understanding of dynamic processes taking place during rockbursts.

  17. Effects of fragmentation, supplementation and the addition of phase II compost to 2nd break compost on mushroom (Agaricus bisporus) yield.

    Science.gov (United States)

    Royse, Daniel J

    2010-01-01

    Double-cropping offers growers an opportunity to increase production efficiency while reducing costs. We evaluated degree of fragmentation, supplementation, and addition of phase II compost (PIIC) to 2nd break compost (2BkC) on mushroom yield and biological efficiency (BE%). One crop was extended as a triple crop in which we evaluated effect of compost type, and addition of phase II compost and supplement. All crops involved removing the casing layer after 2nd break and then using 2BkC for the various treatments. Simple fragmentation of the compost increased mushroom yield by 30% compared to non-fragmented compost. Addition of a commercial supplement to fragmented compost increased mushroom yield by 53-56% over non-supplemented, fragmented 2BkC. Fragmented, supplemented 2BkC resulted in a 99% and 108% yield increase over the non-fragmented control depending on degree of fragmentation (3x, 1x, respectively). A 3rd crop of mushrooms was produced from 2BkC, but yields were about one-half that of the 1st and 2nd crops. Double-cropping (and even triple-cropping) offers growers an opportunity to increase bio-efficiency, reduce production costs, and increase profitability. The cost of producing Agaricus bisporus continues to rise due to increasing expenses including materials, energy, and labor. Optimizing production practices, through double- or triple-cropping, could help growers become more efficient and competitive, and ensure the availability of mushrooms for consumers.

  18. Apparent climate-mediated loss and fragmentation of core habitat of the American pika in the Northern Sierra Nevada, California, USA.

    Science.gov (United States)

    Stewart, Joseph A E; Wright, David H; Heckman, Katherine A

    2017-01-01

    Contemporary climate change has been widely documented as the apparent cause of range contraction at the edge of many species distributions but documentation of climate change as a cause of extirpation and fragmentation of the interior of a species' core habitat has been lacking. Here, we report the extirpation of the American pika (Ochotona princeps), a temperature-sensitive small mammal, from a 165-km2 area located within its core habitat in California's Sierra Nevada mountains. While sites surrounding the area still maintain pikas, radiocarbon analyses of pika fecal pellets recovered within this area indicate that former patch occupancy ranges from before 1955, the beginning of the atmospheric spike in radiocarbon associated with above ground atomic bomb testing, to c. 1991. Despite an abundance of suitable rocky habitat climate warming appears to have precipitated their demise. Weather station data reveal a 1.9°C rise in local temperature and a significant decline in snowpack over the period of record, 1910-2015, pushing pika habitat into increasingly tenuous climate conditions during the period of extirpation. This is among the first accounts of an apparently climate-mediated, modern extirpation of a species from an interior portion of its geographic distribution, resulting in habitat fragmentation, and is the largest area yet reported for a modern-era pika extirpation. Our finding provides empirical support to model projections, indicating that even core areas of species habitat are vulnerable to climate change within a timeframe of decades.

  19. Relationship between Disease Activity and Circulating Level of Collagen II C-Telopeptide Fragments in Papain Induced Osteoarthritis Rat Model

    Directory of Open Access Journals (Sweden)

    Humaira Majeed Khan

    2014-01-01

    Full Text Available Osteoarthritis (OA is a progressive degeneration of articular cartilage leading to failure in functional mobility of joints. It is characterized by morphological, biochemical and molecular changes in histology of cartilage. Different biological markers are used as indicators to precisely predict the stage of cartilage destruction of joints in OA patients and to evaluate the therapeutic efficacy of drugs used for OA. The present research was chalked out to establish relationship between disease activity and serum level of C-terminal telopeptide of type II collagen (CTX-II in experimentally induced OA rat model. Out of 30 male Wistar rats, 25 were used to induce OA by injecting papain (10mg/0.5mL of 0.05M sodium acetate in right knee joints whereas five (control were injected with sterile normal saline solution on day 0. Blood samples (5mL each were collected on weekly basis up to 28th days of post papain injection. Sera were separated and subjected to perform ELISA for estimating CTX-II fragments as cartilage biomarker (CartiLaps ® ELISA kit in experimental groups. Maximum level of CTX–II (pg/mL (40.44±3.07 was observed in sera samples of day 14 post papain injection followed by days 21 (40.22±2.01, 28 (36.82±3.81, 7 (34.48±4.17, 1 (15.08±4.22 and day 0 (2.55±0.10. The early changes in serum CTX-II from day 0 to 14 showed significant association with cartilage damage. Later on, no significant difference was observed in CTX-II level on day 14, 21 and 28 post papain injection. It is concluded that elevation in serum CTX-II level was concomitant with the onset of disease and degradation of cartilage. Moreover, CTX-II is a sensitive diagnostic biomarker to monitor joint disorder severity in papain induced OA rat experimental model on different days. These findings may be used as base line for early diagnosis of disease and initiation of therapy for successful outcome.

  20. Stability Analysis of the EBR-I Mark-II Core Meltdown Accident

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae-Yong; Kang, Chang Mu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The purpose of this paper is to analyze the stability of the EBR-I core meltdown accident using the NuSTAB code. The result of NuSTAB analysis is compared with previous stability analysis by Sandmeier using the root locus method. The Experimental Breeder Reactor I (EBR-1) at Argonne National Laboratory was designed to demonstrate fast reactor breeding and to prove the use of liquid-metal coolant for power production and reached criticality in August 1951. The EBR-I reactor was undergoing a series of physics experiments and the Mark-II core was melted accidentally on Nov. 29, 1955. The experiment was going to increase core temperature to 500C to see if the reactor loses reactivity, and scram when the power reached 1500 kW or doubling of fission rate per second. However the operator scrammed with a slow moving control and missed the shutdown by two seconds and caused the core meltdown. The NuSTAB code has an advantage of analyzing space-dependent fast reactors and predicting regional oscillations compared to the point kinetics. Also, NuSTAB can be useful when the coupled neutronic-thermal-hydraulic codes cannot be used for stability analysis. Future work includes analyses of the PGSFR for various operating conditions as well as further validation of the NuSTAB calculations against SFR stability experiments when such experiments become available.

  1. CORE

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Hundebøll, Martin

    2013-01-01

    different flows. Instead of maintaining these approaches separate, we propose a protocol (CORE) that brings together these coding mechanisms. Our protocol uses random linear network coding (RLNC) for intra- session coding but allows nodes in the network to setup inter- session coding regions where flows...... intersect. Routes for unicast sessions are agnostic to other sessions and setup beforehand, CORE will then discover and exploit intersecting routes. Our approach allows the inter-session regions to leverage RLNC to compensate for losses or failures in the overhearing or transmitting process. Thus, we...... increase the benefits of XORing by exploiting the underlying RLNC structure of individual flows. This goes beyond providing additional reliability to each individual session and beyond exploiting coding opportunistically. Our numerical results show that CORE outperforms both forwarding and COPE...

  2. Immunochemical studies of Shigella flexneri 2a and 6, and Shigella dysenteriae type 1 O-specific polysaccharide-core fragments and their protein conjugates as vaccine candidates.

    Science.gov (United States)

    Kubler-Kielb, Joanna; Vinogradov, Evgeny; Mocca, Christopher; Pozsgay, Vince; Coxon, Bruce; Robbins, John B; Schneerson, Rachel

    2010-07-19

    There is no licensed vaccine for the prevention of shigellosis. Our approach to the development of a Shigella vaccines is based on inducing serum IgG antibodies to the O-specific polysaccharide (O-SP) domain of their lipopolysaccharides (LPS). We have shown that low molecular mass O-SP-core (O-SPC) fragments isolated from Shigella sonnei LPS conjugated to proteins induced significantly higher antibody levels in mice than the full length O-SP conjugates. This finding is now extended to the O-SPC of Shigella flexneri 2a and 6, and Shigella dysenteriae type 1. The structures of O-SPC, containing core plus 1-4 O-SP repeat units (RUs), were analyzed by NMR and mass spectroscopy. The first RUs attached to the cores of S. flexneri 2a and 6 LPS were different from the following RUs in their O-acetylation and/or glucosylation. Conjugates of core plus more than 1 RU were necessary to induce LPS antibodies in mice. The resulting antibody levels were comparable to those induced by the full length O-SP conjugates. In S. dysenteriae type 1, the first RU was identical to the following RUs, with the exception that the GlcNAc was bound to the core in the beta-configuration, while in all other RUs the GlcNAc was present in the alpha-configuration. In spite of this difference, conjugates of S. dysenteriae type 1 core with 1, 2, or 3 RUs induced LPS antibodies in mice with levels statistically higher than those of the full size O-SP conjugates. O-SPC conjugates are easy to prepare, characterize, and standardize, and their clinical evaluation is planned. Published by Elsevier Ltd.

  3. Matérn's hard core models of types I and II with arbitrary compact grains

    DEFF Research Database (Denmark)

    Kiderlen, Markus; Hörig, Mario

    Matérn's classical hard core models can be interpreted as models obtained from a stationary marked Poisson process by dependent thinning. The marks are balls of fixed radius, and a point is retained when its associated ball does not hit any other balls (type I) or when its random birth time...... is strictly smaller than the birth times of all balls hitting it (type II). Extending ideas of [M. Månsson and M. Rudemo. Random patterns of nonoverlapping convex grains. Adv. in Appl. Probab., 34:718--738, 2002.], who considered grains that are isotropic rotations or random scalings of a fixed convex set, we......-Minkowski's inequality, the volume density associated to model II turns out to be bounded by 2−d. This bound is sharp. It is attained asymptotically (when the proposal intensity tends to infinity) only when all grains coincide with one deterministic origin-symmetric convex set. We also discuss how known connections...

  4. Fragmented testament: letters written by World War II resisters before their execution.

    Science.gov (United States)

    Griffin, Anne; Lefer, Jay

    2010-01-01

    Psychoanalysis does not always take moral greatness as a given, a fact attributed by Horney to Freud's view of psychology as a natural science. The French psychiatrist Henri Baruk, however, attempts to bridge the gap between normative and empirical considerations by proposing a model based on the Biblical concept of tsedek, a Hebrew term for altruism coupled with a strong sense of justice. Those who possessed these qualities, Baruk argued, had a more highly developed sense of Self and Other. Consistent with Baruk's model, we argue that moral greatness may be defined as a high degree of moral consciousness combined with courage. Character qualities of World War II resisters, as revealed in a review of over 200 letters written to family and friends immediately before their execution, indicate a strong sense of Self and Other and an equilibrium between a sense of duty and an affective impulse. These qualities are seen in letters written by those engaged in a broad spectrum of resistance activity. The interpersonal quality of these letters; the concern for the suffering that their deaths will cause others; the efforts to reassure those left behind and even to impart useful information and instructions; and the gratitude expressed for large and small favors, all suggest that altruism is a marker for moral greatness, and that it is present even in those whose resistance activity might not at first be classified as altruistic.

  5. Directly probing redox-linked quinones in photosystem II membrane fragments via UV resonance Raman scattering.

    Science.gov (United States)

    Chen, Jun; Yao, Mingdong; Pagba, Cynthia V; Zheng, Yang; Fei, Liping; Feng, Zhaochi; Barry, Bridgette A

    2015-01-01

    In photosynthesis, photosystem II (PSII) harvests sunlight with bound pigments to oxidize water and reduce quinone to quinol, which serves as electron and proton mediators for solar-to-chemical energy conversion. At least two types of quinone cofactors in PSII are redox-linked: QA, and QB. Here, we for the first time apply 257-nm ultraviolet resonance Raman (UVRR) spectroscopy to acquire the molecular vibrations of plastoquinone (PQ) in PSII membranes. Owing to the resonance enhancement effect, the vibrational signal of PQ in PSII membranes is prominent. A strong band at 1661 cm(-1) is assigned to ring CC/CO symmetric stretch mode (ν8a mode) of PQ, and a weak band at 469 cm(-1) to ring stretch mode. By using a pump-probe difference UVRR method and a sample jet technique, the signals of QA and QB can be distinguished. A frequency difference of 1.4 cm(-1) in ν8a vibrational mode between QA and QB is observed, corresponding to ~86 mV redox potential difference imposed by their protein environment. In addition, there are other PQs in the PSII membranes. A negligible anharmonicity effect on their combination band at 2130 cm(-1) suggests that the 'other PQs' are situated in a hydrophobic environment. The detection of the 'other PQs' might be consistent with the view that another functional PQ cofactor (not QA or QB) exists in PSII. This UVRR approach will be useful to the study of quinone molecules in photosynthesis or other biological systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Lead Discovery of Type II BRAF V600E Inhibitors Targeting the Structurally Validated DFG-Out Conformation Based upon Selected Fragments

    Directory of Open Access Journals (Sweden)

    Qingwen Zhang

    2016-07-01

    Full Text Available The success of the first approved kinase inhibitor imatinib has spurred great interest in the development of type II inhibitors targeting the inactive DFG-out conformation, wherein the Phe of the DFG motif at the start of the activation loop points into the ATP binding site. Nevertheless, kinase inhibitors launched so far are heavily biased toward type I inhibitors targeting the active DFG-in conformation, wherein the Phe of the DFG motif flips by approximately 180° relative to the inactive conformation, resulting in Phe and Asp swapping their positions. Data recently obtained with structurally validated type II inhibitors supported the conclusion that type II inhibitors are more selective than type I inhibitors. In our type II BRAF V600E inhibitor lead discovery effort, we identified phenylaminopyrimidine (PAP and unsymmetrically disubstituted urea as two fragments that are frequently presented in FDA-approved protein kinase inhibitors. We therefore defined PAP and unsymmetrically disubstituted urea as privileged fragments for kinase drug discovery. A pharmacophore for type II inhibitors, 4-phenylaminopyrimidine urea (4-PAPU, was assembled based upon these privileged fragments. Lead compound SI-046 with BRAF V600E inhibitory activity comparable to the template compound sorafenib was in turn obtained through preliminary structure–activity relationship (SAR study. Molecular docking suggested that SI-046 is a bona fide type II kinase inhibitor binding to the structurally validated “classical DFG-out” conformation of BRAF V600E. Our privileged fragments-based approach was shown to efficiently deliver a bona fide type II kinase inhibitor lead. In essence, the theme of this article is to showcase the strategy and rationale of our approach.

  7. Light-triggered dissociation of self-assembled β-amyloid aggregates into small, nontoxic fragments by ruthenium (II) complex.

    Science.gov (United States)

    Son, Giyeong; Lee, Byung Il; Chung, You Jung; Park, Chan Beum

    2018-02-01

    The self-assembly of β-amyloid (Aβ) peptides into highly stable plaques is a major hallmark of Alzheimer's disease. Here, we report visible light-driven dissociation of β-sheet-rich Aβ aggregates into small, nontoxic fragments using ruthenium (II) complex {[Ru(bpy) 3 ] 2+ } that functions as a highly sensitive, biocompatible, photoresponsive anti-Aβ agent. According to our multiple analyses using thioflavin T, bicinchoninic acid, dynamic light scattering, atomic force microscopy, circular dichroism, and Fourier transform infrared spectroscopy, [Ru(bpy) 3 ] 2+ successfully disassembled Aβ aggregates by destabilizing the β-sheet secondary structure under illumination of white light-emitting diode light. We validated that photoexcited [Ru(bpy) 3 ] 2+ causes oxidative damages of Aβ peptides, resulting in the dissociation of Aβ aggregates. The efficacy of [Ru(bpy) 3 ] 2+ is attributed to reactive oxygen species, such as singlet oxygen, generated from [Ru(bpy) 3 ] 2+ that absorbed photon energy in the visible range. Furthermore, photoexcited [Ru(bpy) 3 ] 2+ strongly inhibited the self-assembly of Aβ monomers even at concentrations as low as 1 nM and reduced the cytotoxicity of Aβ aggregates. Alzheimer's disease is the most common progressive neurodegenerative disease, affecting more than 13% of the population over age 65. Over the last decades, researchers have focused on understanding the mechanism of amyloid formation, the hallmark of various amyloid diseases including Alzheimer's and Parkinson's. In this paper, we successfully demonstrate the dissociation of β-Amyloid (Aβ) aggregates into small, less-amyloidic fragments by photoexcited [Ru(bpy) 3 ] 2+ through destabilization of β-sheet secondary structure. We validated the light-triggered dissociation of amyloid structure using multiple analytical tools. Furthermore, we confirmed that photoexcited [Ru(bpy) 3 ] 2+ reduces cytotoxicity of Aβ aggregates. Our work should open a new horizon in the study of

  8. Network characteristics of individual pigments in cyanobacterial photosystem II core complexes

    Science.gov (United States)

    Lee, Eun; Holme, Petter

    2013-12-01

    Part of the excitation energy transfer (EET) characteristics of the photosystem II (PSII) comes from the interconnection between pigments. To understand the correlation between the EET and the pigments' interaction structure, we construct a network from the EET rates which are related to both the distance between the pigments (chlorophylls and pheophytins) and their spatial orientations. Especially, we investigate how well the PS II core complex's EET functionality can be explained by using only the network topology in Thermosynechococcus vulcanus 1.9 °A. Starting from the Förster theory, we construct a network of EET pathways. For an analysis of the network structure, we calculate common network-structural measures like betweenness centrality, eigenvector centrality and weighted clustering. These measures can reflect the role of individual pigments in the EET network. In our work, we found that some well-known properties were reproduced by the network analysis of the simplified network, which means that the topology of the network encodes functionally relevant information. For example, from the network structural analysis, we can infer that most of the chlorophyll molecules (clorophylls) in the pigment-protein complex CP47 have heightened probability to transfer energy compared with other chlorophylls. We also see that the active branch chlorophylls in the reaction center are characterized by a high eigenvector centrality, a high betweenness centrality and a low weighted clustering coefficient. This is indicative of functionally important vertices.

  9. Development of a standard data base for FBR core nuclear design. 10. Reevaluation of atomic number density of JOYO Mk-II core

    Energy Technology Data Exchange (ETDEWEB)

    Numata, Kazuyuki; Sato, Wakaei [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Ishikawa, Makoto; Arii, Yoshio [Nuclear Energy System Incorporation, Tokyo (Japan)

    1999-07-01

    The material composition of JOYO Mk-II core components in its initial core was reevaluated as a part of the effort for developing a standard data base for FBR core nuclear design. The special feature of the reevaluation is to treat the decay of Pu-241 isotope, so that the atomic number densities of Pu-241 and Am-241 in fuel assemblies can be exactly evaluated on the initial critical date, Nov. 22nd, 1982. Further, the atomic number densities of other core components were also evaluated to improve the analytical accuracy. Those include the control rods which were not so strictly evaluated in the past, and the dummy fuels and the neutron sources which were not treated in the analytical model so far. The results of the present reevaluation were as follows: (1) The changes of atomic number densities of the major nuclides such as Pu-239, U-235 and U-238 were about {+-}0.2 to 0.3%. On the other hand, the number density of Pu-241, which was the motivation of the present work, was reduced by 12%. From the fact, the number densities in the past analysis might be based on the isotope measurement of the manufacturing point of time without considering the decay of Pu-241. (2) As the other core components, the number densities of control rods and outer reflector-type A were largely improved. (author)

  10. Coupled neutronics and thermal hydraulics of high density cores for FRM II

    Energy Technology Data Exchange (ETDEWEB)

    Breitkreutz, Harald

    2011-03-04

    According to the 'Verwaltungsvereinbarung zwischen Bund und Land vom 30.5.2003' and its updating on 13.11.2010, the Forschungs-Neutronenquelle Heinz Maier-Leibnitz, Frm II, has to convert its fuel element to an uranium enrichment which is significantly lower than the current 93%, in case this is economically reasonable and doesn't impact the reactor performance immoderate. In the framework of this conversion, new calculations regarding neutronics and thermal hydraulics for the anticipated core configurations have to be made. The computational power available nowadays allows for detailed 3D calculations, on the neutronic as well as on the thermal hydraulic side. In this context, a new program system, 'X{sup 2}', was developed. It couples the Monte Carlo code McnpX, the computational fluid dynamics code Cfx and the burn-up code sequence MonteBurns. The codes were modified and extended to meet the requirements of the coupled calculation concept. To verify the new program system, highly detailed calculations for the current fuel element were made and compared to simulations and measurements that were performed in the past. The results strengthen the works performed so far and show that the original, conservative approach overestimates all critical thermal hydraulic values. Using the CFD software, effects like the impact of the combs that fix the fuel plates and the pressure drop at the edges of the fuel plates were studied in great detail for the first time. Afterwards, a number of possible new fuel elements with lower enrichment, based on disperse and monolithic UMo (uranium with 8 wt.-% Mo) were analysed. A number of straight-forward conversion scenarios was discussed, showing that a further compaction of the fuel element, an extended cycle length or an increased reactor power is needed to compensate the flux loss, which is caused by the lower enrichment. This flux loss is in excess of 7%. The discussed new fuel elements include a 50

  11. Synthesis, characterisation, cellular uptake and cytotoxicity of functionalised magnetic ruthenium (II) polypyridine complex core-shell nanocomposite.

    Science.gov (United States)

    Kandibanda, Srinivasa Rao; Gundeboina, Narasihmha; Das, Sourav; Sunkara, V Manorama

    2018-01-01

    The development of multifunctional nanoparticles comprising of a magnetic core in conjunction with appropriate molecules with capabilities to impart functionalities like luminescent, specific binding sites to facilitate attachment of moieties. This has attracted increasing attention and enables identification of promising candidates using for applications such as diagnostics and cure through early detection and localized delivery. Many studies have been performed on the synthesis and cellular interactions of core-shell nanoparticles, in which a functional inorganic core is coated with a biocompatible polymer layer that should reduce nonspecific uptake and cytotoxicity Here we report the synthesis and characterisation of multifunctional core-shell magnetic, luminescent nanocomposite (Fe 3 O 4 @SiO 2 @[Ru(Phen) 3 ] 2+ @SiO 2 @NH 2 ). Fe 3 O 4 as core and a luminescent ruthenium (II) complex encapsulated with silica shell, and then it is functionalized by an amine group by APTMS. The magnetic, luminescent, and biological activity of this multifunctional nanocomposite have also been studied to prove the nanocomposite is biocompatible, cellular uptake. The synthesized nanocomposite was completely characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and emission spectroscopy. MTT assay and cellular uptake by flow cytometry results proved that magnetic ruthenium (II) polypyridine complex - core shell nanocomposite has biocompatibility, minimum cytotoxicity and internalized inside B16F10 cells and confirms the potential biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Core map generation for the ITU TRIGA Mark II research reactor using Genetic Algorithm coupled with Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Türkmen, Mehmet, E-mail: tm@hacettepe.edu.tr [Nuclear Engineering Department, Hacettepe University, Beytepe Campus, Ankara (Turkey); Çolak, Üner [Energy Institute, Istanbul Technical University, Ayazağa Campus, Maslak, Istanbul (Turkey); Ergün, Şule [Nuclear Engineering Department, Hacettepe University, Beytepe Campus, Ankara (Turkey)

    2015-12-15

    Highlights: • Optimum core maps were generated for the ITU TRIGA Mark II Research Reactor. • Calculations were performed using a Monte Carlo based reactor physics code, MCNP. • Single-Objective and Multi-Objective Genetic Algorithms were used for the optimization. • k{sub eff} and ppf{sub max} were considered as the optimization objectives. • The generated core maps were compared with the fresh core map. - Abstract: The main purpose of this study is to present the results of Core Map (CM) generation calculations for the İstanbul Technical University TRIGA Mark II Research Reactor by using Genetic Algorithms (GA) coupled with a Monte Carlo (MC) based-particle transport code. Optimization problems under consideration are: (i) maximization of the core excess reactivity (ρ{sub ex}) using Single-Objective GA when the burned fuel elements with no fresh fuel elements are used, (ii) maximization of the ρ{sub ex} and minimization of maximum power peaking factor (ppf{sub max}) using Multi-Objective GA when the burned fuels with fresh fuels are used. The results were obtained when all the control rods are fully withdrawn. ρ{sub ex} and ppf{sub max} values of the produced best CMs were provided. Core-averaged neutron spectrum, and variation of neutron fluxes with respect to radial distance were presented for the best CMs. The results show that it is possible to find an optimum CM with an excess reactivity of 1.17 when the burned fuels are used. In the case of a mix of burned fuels and fresh fuels, the best pattern has an excess reactivity of 1.19 with a maximum peaking factor of 1.4843. In addition, when compared with the fresh CM, the thermal fluxes of the generated CMs decrease by about 2% while change in the fast fluxes is about 1%.Classification: J. Core physics.

  13. Phylogenetic analysis of the core histone doublet and DNA topo II genes of Marseilleviridae: evidence of proto-eukaryotic provenance.

    Science.gov (United States)

    Erives, Albert J

    2017-11-28

    While the genomes of eukaryotes and Archaea both encode the histone-fold domain, only eukaryotes encode the core histone paralogs H2A, H2B, H3, and H4. With DNA, these core histones assemble into the nucleosomal octamer underlying eukaryotic chromatin. Importantly, core histones for H2A and H3 are maintained as neofunctionalized paralogs adapted for general bulk chromatin (canonical H2 and H3) or specialized chromatin (H2A.Z enriched at gene promoters and cenH3s enriched at centromeres). In this context, the identification of core histone-like "doublets" in the cytoplasmic replication factories of the Marseilleviridae (MV) is a novel finding with possible relevance to understanding the origin of eukaryotic chromatin. Here, we analyze and compare the core histone doublet genes from all known MV genomes as well as other MV genes relevant to the origin of the eukaryotic replisome. Using different phylogenetic approaches, we show that MV histone domains encode obligate H2B-H2A and H4-H3 dimers of possible proto-eukaryotic origin. MV core histone moieties form sister clades to each of the four eukaryotic clades of canonical and variant core histones. This suggests that MV core histone moieties diverged prior to eukaryotic neofunctionalizations associated with paired linear chromosomes and variant histone octamer assembly. We also show that MV genomes encode a proto-eukaryotic DNA topoisomerase II enzyme that forms a sister clade to eukaryotes. This is a relevant finding given that DNA topo II influences histone deposition and chromatin compaction and is the second most abundant nuclear protein after histones. The combined domain architecture and phylogenomic analyses presented here suggest that a primitive origin for MV histone genes is a more parsimonious explanation than horizontal gene transfers + gene fusions + sufficient divergence to eliminate relatedness to eukaryotic neofunctionalizations within the H2A and H3 clades without loss of relatedness to each of

  14. A simple microfluidic system for efficient capillary electrophoretic separation and sensitive fluorimetric detection of DNA fragments using light-emitting diode and liquid-core waveguide techniques.

    Science.gov (United States)

    Wang, Shi-Li; Fan, Xiao-Feng; Xu, Zhang-Run; Fang, Zhao-Lun

    2005-10-01

    A miniaturized CE system has been developed for fast DNA separations with sensitive fluorimetric detection using a rectangle type light-emitting diode (LED). High sensitivity was achieved by combining liquid-core waveguide (LCW) and lock-in amplification techniques. A Teflon AF-coated silica capillary on a compact 6x3 cm baseplate served as both the separation channel for CE separation and as an LCW for light transmission of fluorescence emission to the detector. An electronically modulated LED illuminated transversely through a 0.2 mm aperture, the detection point on the LCW capillary without focusing, and fluorescence light was transmitted to the capillary outlet. To simplify the optics and enhance collection of light from the capillary outlet, an outlet reservoir was designed, with a light transmission window, positioned directly in front of a photomultiplier tube (PMT), separated only by a high pass filter. Automated sample introduction was achieved using a sequential injection system through a split-flow interface that allowed effective release of gas bubbles. In the separation of a phiX174 HaeIII DNA digest sample, using ethidium bromide as labeling dye, all 11 fragments of the sample were effectively resolved in 400 s, with an S/N ratio comparable to that of a CE system with more sophisticated LIF.

  15. Neutronic and thermal-hydraulic analysis of new irradiation channels inside the Moroccan TRIGA Mark II research reactor core.

    Science.gov (United States)

    Chham, E; El Bardouni, T; Benaalilou, K; Boukhal, H; El Bakkari, B; Boulaich, Y; El Younoussi, C; Nacir, B

    2016-10-01

    This study was conducted to improve the capacity of radioisotope production in the Moroccan TRIGA Mark II research reactor, which is considered as one of the most important applications of research reactors. The aim of this study is to enhance the utilization of TRIGA core in the field of neutron activation and ensure an economic use of the fuel. The main idea was to create an additional irradiation channel (IC) inside the core. For this purpose, three new core configurations are proposed, which differ according to the IC position in the core. Thermal neutron flux distribution and other neutronic safety parameters such as power peaking factors, excess reactivity, and control rods worth reactivity were calculated using the Monte Carlo N-Particle Transport (MCNP) code and neutron cross-section library based on ENDF/B-VII evaluation. The calculated thermal flux in the central thimble (CT) and in the added IC for the reconfigured core is compared with the thermal flux in the CT of the existing core, which is taken as a reference. The results show that all the obtained fluxes in CTs are very close to the reference value, while a remarkable difference is observed between the fluxes in the new ICs and reference. This difference depends on the position of IC in the reactor core. To demonstrate that the Moroccan TRIGA reactor could safely operate at 2MW, with new configurations based on new ICs, different safety-related thermal-hydraulic parameters were investigated. The PARET model was used in this study to verify whether the safety margins are met despite the new modifications of the core. The results show that it is possible to introduce new ICs safely in the reactor core, because the obtained values of the parameters are largely far from compromising the safety of the reactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Pressure dependent optical gain in Type-II PbSe/PbS core /shell quantum dots

    Science.gov (United States)

    Saravanamoorthy, S. N.; John Peter, A.; Lee, Chang Woo

    2017-11-01

    Pressure induced nonlinear optical properties of Type-II lead based core/shell quantum dot heterostructure are investigated. The pressure dependent exciton binding energies are obtained with the increase of shell thickness for various inner core radii. The exciton interaction energies in a PbSe/PbS core/shell quantum dot inner core radii are found in the presence of hydrostatic pressure using variational method within the single band effective mass approximation. The threshold current density with the hydrostatic pressure and inner dot radii in a PbSe/PbS dot with the constant shell width is obtained. The pressure dependence on peak optical gain with the current density in a PbSe/PbS core/shell quantum dot with the fixed carrier density is found. The pressure related optical gain with the photon energy in a PbSe/PbS core/shell quantum dot is also obtained. The results show that the threshold current density increases by 20% when the pressure increases from 0 GPa to 4 GPa for 20 Å quantum dot radius whereas 16% of increase in threshold current density is observed for 50 Å quantum dot radius for the same increase of pressure values. The peak of the optical gain is observed to increase nonlinearly with the applied hydrostatic pressure and 12% of optical gain is enhanced for every 2 GPa pressure value. The results will be useful for some potential applications in near infrared light sources.

  17. Probing dark matter with star clusters: a dark matter core in the ultra-faint dwarf Eridanus II

    Science.gov (United States)

    Contenta, Filippo; Balbinot, Eduardo; Petts, James A.; Read, Justin I.; Gieles, Mark; Collins, Michelle L. M.; Peñarrubia, Jorge; Delorme, Maxime; Gualandris, Alessia

    2018-02-01

    We present a new technique to probe the central dark matter (DM) density profile of galaxies that harnesses both the survival and observed properties of star clusters. As a first application, we apply our method to the `ultra-faint' dwarf Eridanus II (Eri II) that has a lone star cluster ˜45 pc from its centre. Using a grid of collisional N-body simulations, incorporating the effects of stellar evolution, external tides and dynamical friction, we show that a DM core for Eri II naturally reproduces the size and the projected position of its star cluster. By contrast, a dense cusped galaxy requires the cluster to lie implausibly far from the centre of Eri II (>1 kpc), with a high inclination orbit that must be observed at a particular orbital phase. Our results, therefore, favour a dark matter core. This implies that either a cold DM cusp was `heated up' at the centre of Eri II by bursty star formation, or we are seeing an evidence for physics beyond cold DM.

  18. The influence of the boat-to-chair conversion on the demetallation of the nickel(II) complex of an open-chain tetramine containing a piperazine fragment.

    Science.gov (United States)

    Boiocchi, Massimo; Bonizzoni, Marco; Fabbrizzi, Luigi; Foti, Francesco; Licchelli, Maurizio; Taglietti, Angelo; Zema, Michele

    2004-02-21

    The nickel(II) complex with an open chain tetramine containing a piperazine fragment (1) displays an unusual resistance to demetallation in acidic solution and exhibits a lifetime of about five minutes in a solution 0.1 M in HClO4 and 7.0 M in NaClO4. Sluggishness with respect to the demetallation is ascribed to the occurrence of the boat-to-chair conformational conversion of the piperazine fragment, which implies the passage through the highly energetic half-boat transition state. The use of a high concentration of the inert electrolyte induces a 'salting out' effect on both thermodynamics (stability of metal complexes is enhanced) and kinetics (resistance to demetallation is increased).

  19. Microwave-assisted synthesis of water-dispersed CdTe/CdSe core/shell type II quantum dots

    Science.gov (United States)

    2011-01-01

    A facile synthesis of mercaptanacid-capped CdTe/CdSe (core/shell) type II quantum dots in aqueous solution by means of a microwave-assisted approach is reported. The results of X-ray diffraction and high-resolution transmission electron microscopy revealed that the as-prepared CdTe/CdSe quantum dots had a core/shell structure with high crystallinity. The core/shell quantum dots exhibit tunable fluorescence emissions by controlling the thickness of the CdSe shell. The photoluminescent properties were dramatically improved through UV-illuminated treatment, and the time-resolved fluorescence spectra showed that there is a gradual increase of decay lifetime with the thickness of CdSe shell. PMID:21711922

  20. Microwave-assisted synthesis of water-dispersed CdTe/CdSe core/shell type II quantum dots

    Directory of Open Access Journals (Sweden)

    Sai Li-Man

    2011-01-01

    Full Text Available Abstract A facile synthesis of mercaptanacid-capped CdTe/CdSe (core/shell type II quantum dots in aqueous solution by means of a microwave-assisted approach is reported. The results of X-ray diffraction and high-resolution transmission electron microscopy revealed that the as-prepared CdTe/CdSe quantum dots had a core/shell structure with high crystallinity. The core/shell quantum dots exhibit tunable fluorescence emissions by controlling the thickness of the CdSe shell. The photoluminescent properties were dramatically improved through UV-illuminated treatment, and the time-resolved fluorescence spectra showed that there is a gradual increase of decay lifetime with the thickness of CdSe shell.

  1. Core cross-linked block ionomer micelles as pH-responsive carriers for cis-diamminedichloroplatinum(II).

    Science.gov (United States)

    Oberoi, Hardeep S; Laquer, Frederic C; Marky, Luis A; Kabanov, Alexander V; Bronich, Tatiana K

    2011-07-15

    Benefits of the frequently prescribed platinum (II) chemotherapy drugs are compromised by undesirable side effects, poor pharmacokinetics and development of drug resistance. Polymer micelles derived from amphiphilic block copolymers, offer a novel macromolecular platform for carrier based delivery of such compounds. Soft polymeric nanocarriers were synthesized by template-assisted method involving condensation of the poly(ethylene oxide)-b-polymethacrylate anions by metal ions into core-shell block ionomer complex micelles followed by chemical cross-linking of the polyion chains in the micelle cores. The resulting micelles can efficiently incorporate cisplatin with a high loading capacity (up to 42% w/w). Core cross-linking stabilized the micelles against structural disintegration and prevented premature drug release. The reversible cisplatin entrapment involved the carboxylate groups of the micellar core. The drug was released in a pH-responsive manner, without loss of its biological activity. The stable cross-linked polymer micelles can potentially improve platinum (II) drug disposition with improved therapeutic potential. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Study of charm quark fragmentation into D{sup *} mesons with the H1 detector at HERA II

    Energy Technology Data Exchange (ETDEWEB)

    Liptaj, Andrej

    2008-12-15

    In this work charm quark fragmentation into D{sup *} mesons is investigated in deep-inelastic electron proton collisions. This work is based on data collected in the years 2004 - 2007 by the H1 detector at HERA, corresponding to a total integrated luminosity of 354.1 pb{sup -1}. Three observables denoted z{sub jet},z{sub hem} and z{sub hem}{sup (jet)} are measured, each of them meant to approximate the momentum fraction of the charm quark transferred to the D{sup *} meson. In case of z{sub jet} the quark momentum is estimated as the momentum of the D{sup *} jet, for the two other observables it is approximated by the momentum of an appropriately chosen D{sup *} hemisphere. The visible range is defined by the phase space requirements on the DIS events: Q{sup 2} > 5 GeV{sup 2}, 0.05 < y < 0.6 and by the cuts applied on the reconstructed D{sup *{+-}} particles: 1.5 GeV < p{sub T}(D{sup *}) < 15.0 GeV and vertical stroke {eta}(D{sup *}) vertical stroke < 1.5. An additional constraint E{sub T}(D{sup *}jet) > 3.0 GeV enters the phase space definition in case of z{sub jet} and z{sub hem}{sup (jet)}, where a reconstructed jet containing the D{sup *} meson is required. Within this phase space the normalized single differential cross sections are measured in bins of the three observables. Two Monte Carlo models, RAPGAP and CASCADE, both interfaced with the PYTHIA program for the Lund string fragmentation, are used to make predictions of the respective cross sections for different parametrizations (Peterson and Kartvelishvili) of the charm fragmentation function. The difference in cross sections between data and Monte Carlo model predictions for different values of the fragmentation parameter is quantified by calculating values of {chi}{sup 2} in order to extract optimal parameters for the Peterson and Kartvelishvili parametrization. Using predictions from PYTHIA for e{sup +}e{sup -} annihilation optimal parameters are extracted also from the published BELLE and ALEPH data

  3. Zinc(II)-cyclen polyacrylamide gel electrophoresis for detection of mutations in short Ade/Thy-rich DNA fragments.

    Science.gov (United States)

    Kinoshita-Kikuta, Emiko; Kinoshita, Eiji; Harada, Naoko; Koike, Tohru

    2011-01-15

    We describe an improved gel-based method with an additive Zn(2+)-cyclen complex (cyclen, 1,4,7,10-tetraazacyclododecane), Zn(2+)-cyclen-PAGE, for mutation detection in DNA fragments by PCR that contain more than 65% Ade/Thy bases and fewer than 100base pairs (bp). Existing techniques have a problem in analyzing such short Ade/Thy-rich fragments because the duplexes are disrupted and are not detectable due to binding of Zn(2+)-cyclen to Thy bases. In this strategy using a PCR primer with a Gua/Cyt-lined sequence attached at its 5'-end, we successfully detected a mutation in an 86-bp Ade/Thy-rich region of the BRCA1 gene from formalin-fixed paraffin-embedded breast cancer-tissue sections. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. The Effects of Habitat Fragmentation on the Behavior of the Cotton Rat (Sigmodon hispidus):Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, G.W.; Drelin, E.A.; Mabry, K.E.

    2001-07-01

    The authors studied the movements of cotton rats and cotton mice in experimental landscapes at the SRS in order to determine the effects of fragmentation and connectivity between habitat patches on dispersal movements and population dynamics. Densities between connected and isolated patches were not different. Small patches tended to support higher densities. Cotton rats were more common in corridors than expected and cotton mice were more likely to leave by a corridor.

  5. Both Met(109) and Met(112) are Utilized for Cu(II) Coordination to the Amyloidogenic Fragment of the Human Prion Protein

    Energy Technology Data Exchange (ETDEWEB)

    Shearer, J.; Soh, P; Lentz, S

    2008-01-01

    The prion protein is a ubiquitous neuronal membrane protein. Misfolding of the prion protein has been implicated in transmissible spongiform encephalopathies (prion diseases). It has been demonstrated that the human prion protein (PrP) is capable of coordinating at least five Cu{sup II} ions under physiological conditions; four copper binding sites can be found in the octarepeat domain between residues 61 and 91, while another copper binding site can be found in the unstructured 'amyloidogenic' domain between residues 91 and 126 PrP(91-126). Herein we expand upon a previous study (J. Shearer, P. Soh, Inorg. Chem. 46 (2007) 710-719) where we demonstrated that the physiologically relevant high affinity Cu{sup II} coordination site within PrP(91-126) is found between residues 106 and 114. It was shown that Cu{sup II} is contained within a square planar (N/O){sub 3}S coordination environment with one His imidazole ligand (H(111)) and one Met thioether ligand (either M(109) or M(112)). The identity of the Met thioether ligand was not identified in that study. In this study we perform a detailed investigation of the Cu{sup II} coordination environment within the PrP fragment containing residues 106-114 (PrP(106-114)) involving optical, X-ray absorption, EPR, and fluorescence spectroscopies in conjunction with electronic structure calculations. By using derivatives of PrP(106-114) with systematic Met {yields} Ile 'mutations' we show that the Cu{sup II} coordination environment within PrP(106-114) is actually comprised of a mixture of two major species; one CuII(N/O){sub 3}S center with the M(109) thioether coordinated to Cu{sup II} and another Cu{sup II}(N/O){sub 3}S center with the M(112) thioether coordinated to Cu{sup II}. Furthermore, deletion of one or more Met residues from the primary sequence of PrP(106-114) both reduces the Cu{sup II} affinity of the peptide by two to seven fold, and renders the resulting Cu{sup II} metallopeptides redox

  6. Seismic assessment of WSDOT bridges with prestressed hollow core piles : part II.

    Science.gov (United States)

    2009-12-01

    This report investigates the seismic performance of a reinforced concrete : bridge with prestressed hollow core piles. Both nonlinear static and nonlinear dynamic : analyses were carried out. A three-dimensional spine model of the bridge was : ...

  7. Spectroscopic properties of the CP43 core antenna protein of photosystem II

    NARCIS (Netherlands)

    Groot, ML; Frese, RN; de Weerd, FL; Bromek, K.; Pettersson, A.; Peterman, EJG; van Stokkum, IHM; van Grondelle, R; Dekker, JP

    1999-01-01

    CP43 is a chlorophyll-protein complex that funnels excitation energy from the main light-harvesting system of photosystem II to the photochemical reaction center. We purified CP43 from spinach photosystem II membranes in the presence of the nonionic detergent n-dodecyl-β,d-maltoside and recorded its

  8. Explicit identification and implicit recognition of facial emotions: II. Core domains and relationships with general cognition.

    Science.gov (United States)

    Mathersul, Danielle; Palmer, Donna M; Gur, Ruben C; Gur, Raquel E; Cooper, Nick; Gordon, Evian; Williams, Leanne M

    2009-04-01

    Both general and social cognition are important in providing endophenotypic markers and predicting real-world functional outcomes of clinical psychiatric disorders. However, to date, focus has been on general cognition, rather than on core domains of social/emotional cognition. This study sought to determine core domains of emotion processing for both explicit identification and implicit recognition and their relationships with core domains of general cognition. Age effects and sex differences were also investigated. A sample of 1,000 healthy individuals (6 to 91 years, 53.5% female) undertook the WebNeuro tests of emotion identification and recognition and tests of general cognitive function. Factor analysis revealed seven core domains of emotion processing: speed of explicit emotion identification, speed of implicit emotion recognition, implicit emotion recognition accuracy, "threat" processing, sadness-disgust identification, "positive emotion" processing, and general "face perception." Seven corresponding core domains of general cognition were identified: information-processing speed, executive function, sustained attention/vigilance, verbal memory, working-memory capacity, inhibition/impulsivity, and sensorimotor function. Factors of emotion processing generally showed positive associations with those of general cognitive function, suggesting commonality in processing speed in particular. Moreover, age had a consistent nonlinear impact on both emotion processing and general cognitive factors, while sex differences were more specific. These findings contribute to a normative and standardized structure for assessment of emotional and general cognition in clinical groups.

  9. Accurate pan-specific prediction of peptide-MHC class II binding affinity with improved binding core identification

    DEFF Research Database (Denmark)

    Andreatta, Massimo; Karosiene, Edita; Rasmussen, Michael

    2015-01-01

    by T helper lymphocytes. NetMHCIIpan is a state-of-the-art method for the quantitative prediction of peptide binding to any human or mouse MHC class II molecule of known sequence. In this paper, we describe an updated version of the method with improved peptide binding register identification. Binding...... with known binding registers, the new method NetMHCIIpan-3.1 significantly outperformed the earlier 3.0 version. We illustrate the impact of accurate binding core identification for the interpretation of T cell cross-reactivity using tetramer double staining with a CMV epitope and its variants mapped...... to the epitope binding core. NetMHCIIpan is publicly available at http://www.cbs.dtu.dk/services/NetMHCIIpan-3.1....

  10. [Effect of core: dentin thickness ratio on the flexure strength of IPS Empress II heat-pressed all-ceramic restorative material].

    Science.gov (United States)

    Liu, Yi-hong; Feng, Hai-lan; Bao, Yi-wang; Qiu, Yan

    2007-02-18

    To evaluate the effect of core:dentin thickness ratio on the flexure strength, fracture mode and origin of bilayered IPS Empress II ceramic composite specimens. IPS Empress II core ceramic, dentin porcelain and bilayered composite specimens with core:dentin thickness ratio of 2:1 and 1:1 were tested in three-point flexure strength. Mean strengths and standard deviations were determined. The optical microscopy was employed for identification of the fracture mode and origin. The flexure strength of dentin porcelain was the smallest(62.7 MPa), and the strength of bilayered composite specimens was smaller than single-layered core ceramic(190.2 MPa). The core: dentin ratio did not influence the strength of bilayered composite specimens. The frequency of occurrence of bilayered specimen delaminations was higher in the group of core: dentin thickness ratio of 1:1 than in the group of 2:1. IPS Empress II core ceramic was significantly stronger than veneering dentin porcelain. Core:dentin thickness ratio could significantly influence the fracture mode and origin, and bilayered IPS Empress II ceramic composite specimens showed little influence in the fracture strength.

  11. Many Drops Interactions II: Simulation of Coalescence, Flocculation and Fragmentation of Multiple Colliding Drops with Smoothed Particle Hydrodynamics

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2012-06-01

    Full Text Available In this study, the SPH method is applied to simulate for the first time the multiple hydrodynamics collisions and the formation of clusters of equally sized liquid drops in three-dimensional space. Smoothed Particle Hydrodynamics is a Lagrangian mesh-free formalism and has been useful to model continuous fluid. This formalism is employed to solve the Navier-Stokes equations by replacing the fluid with a set of particles. These particles are interpolation points from which properties of the fluid can be determined. We observe that when the velocity of collision varies between 0.2 mm/ms and 30.0 mm/ms different results may arise, such as: coalescence, fragmentation and formation of clusters of liquid drops. The velocity vector fields formed inside the drops during the collision process are shown.

  12. Integration of Skills and Competencies in the Missouri Marketing Education Core Curriculum. Section II.

    Science.gov (United States)

    Ruhland, Sheila K.; Wilkinson, Richard F.

    This publication contains teaching activities for the Fundamentals of Marketing and Advanced Marketing curriculum. Chapter 1 presents an alignment of the marketing education core competencies within the nine curriculum units for Fundamentals of Marketing and Advanced Marketing as they relate to the basic academic skills, advanced academic skills,…

  13. Recognition of core and flanking amino acids of MHC class II-bound peptides by the T cell receptor.

    Science.gov (United States)

    Sant'Angelo, Derek B; Robinson, Eve; Janeway, Charles A; Denzin, Lisa K

    2002-09-01

    CD4 T cells recognize peptides bound to major histocompatibility complex (MHC) class II molecules. Most MHC class II molecules have four binding pockets occupied by amino acids 1, 4, 6, and 9 of the minimal peptide epitope, while the residues at positions 2, 3, 5, 7, and 8 are available to interact with the T cell receptor (TCR). In addition MHC class II bound peptides have flanking residues situated outside of this peptide core. Here we demonstrate that the flanking residues of the conalbumin peptide bound to I-A(k) have no effect on recognition by the D10 TCR. To study the role of peptide flanks for recognition by a second TCR, we determined the MHC and TCR contacting amino acids of the I-A(b) bound Ealpha peptide. The Ealpha peptide is shown to bind I-A(b) using four alanines as anchor residues. TCR recognition of Ealpha peptides with altered flanking residues again suggested that, in general, no specific interactions occurred with the peptide flanks. However, using an HLA-DM-mediated technique to measure peptide binding to MHC class II molecules, we found that the peptide flanking residues contribute substantially to MHC binding.

  14. Highly efficient near-infrared light-emitting diodes by using type-II CdTe/CdSe core/shell quantum dots as a phosphor.

    Science.gov (United States)

    Shen, Huaibin; Zheng, Ying; Wang, Hongzhe; Xu, Weiwei; Qian, Lei; Yang, Yixing; Titov, Alexandre; Hyvonen, Jake; Li, Lin Song

    2013-11-29

    In this paper, we present an innovative method for the synthesis of CdTe/CdSe type-II core/shell structure quantum dots (QDs) using 'greener' chemicals. The PL of CdTe/CdSe type-II core/shell structure QDs ranges from 600 to 820 nm, and the as-synthesized core/shell structures show narrow size distributions and stable and high quantum yields (50–75%). Highly efficient near-infrared light-emitting diodes (LEDs) have been demonstrated by employing the CdTe/CdSe type-II core/shell QDs as emitters. The devices fabricated based on these type-II core/shell QDs show color-saturated near-infrared emission from the QD layers, a low turn-on voltage of 1.55 V, an external quantum efficiency (EQE) of 1.59%, and a current density and maximum radiant emittance of 2.1 × 10(3) mA cm−2 and 17.7 mW cm−2 at 8 V; it is the first report to use type-II core/shell QDs as near-infrared emitters and these results may offer a practicable platform for the realization of near-infrared QD-based light-emitting diodes, night-vision-readable displays, and friend/foe identification system.

  15. Novel Bioinformatics-Based Approach for Proteomic Biomarkers Prediction of Calpain-2 & Caspase-3 Protease Fragmentation: Application to βII-Spectrin Protein

    Science.gov (United States)

    El-Assaad, Atlal; Dawy, Zaher; Nemer, Georges; Kobeissy, Firas

    2017-01-01

    The crucial biological role of proteases has been visible with the development of degradomics discipline involved in the determination of the proteases/substrates resulting in breakdown-products (BDPs) that can be utilized as putative biomarkers associated with different biological-clinical significance. In the field of cancer biology, matrix metalloproteinases (MMPs) have shown to result in MMPs-generated protein BDPs that are indicative of malignant growth in cancer, while in the field of neural injury, calpain-2 and caspase-3 proteases generate BDPs fragments that are indicative of different neural cell death mechanisms in different injury scenarios. Advanced proteomic techniques have shown a remarkable progress in identifying these BDPs experimentally. In this work, we present a bioinformatics-based prediction method that identifies protease-associated BDPs with high precision and efficiency. The method utilizes state-of-the-art sequence matching and alignment algorithms. It starts by locating consensus sequence occurrences and their variants in any set of protein substrates, generating all fragments resulting from cleavage. The complexity exists in space O(mn) as well as in O(Nmn) time, where N, m, and n are the number of protein sequences, length of the consensus sequence, and length per protein sequence, respectively. Finally, the proposed methodology is validated against βII-spectrin protein, a brain injury validated biomarker.

  16. Poly(amidehydroxyurethane template magnetite NPs electrosynthesis. II. Core and shell characterization

    Directory of Open Access Journals (Sweden)

    Laura Ursu

    2013-10-01

    Full Text Available Core and layer polymer characterization of magnetite nanoparticles (NPs surface-functionalized with poly(amidehydroxyurethane (PAmHU, obtained by a new electrochemical synthesis route is presented. The core magnetic properties were investigated by Vibrating Sample Magnetometer (VSM, showing that the obtained NPs have superparamagnetic to ferromagnetic behaviour (very low coercivity and remanence. The magnetite–PAmHU NPs morphology and size were studied by Atomic Force Microscopy (AFM and Dynamic Light Scattering (DLS; both methods showed the existence of PAmHU out-flaked layer on NPs. Structural analysis by Infrared spectroscopy (FTIR and Thermogravimetry (TG confirm the out-flaking of magnetic NPs with PAmHU.

  17. The core helium flash revisited. II. Two and three-dimensional hydrodynamic simulations

    Science.gov (United States)

    Mocák, M.; Müller, E.; Weiss, A.; Kifonidis, K.

    2009-07-01

    Context: We study turbulent convection during the core helium flash close to its peak by comparing the results of two and three-dimensional hydrodynamic simulations. Aims: In a previous study we found that the temporal evolution and the properties of the convection inferred from two-dimensional hydrodynamic studies are similar to those predicted by quasi-hydrostatic stellar evolutionary calculations. However, as vorticity is conserved in axisymmetric flows, two-dimensional simulations of convection are characterized by incorrect dominant spatial scales and exaggerated velocities. Here, we present three-dimensional simulations that eliminate the restrictions and flaws of two-dimensional models and that provide a geometrically unbiased insight into the hydrodynamics of the core helium flash. In particular, we study whether the assumptions and predictions of stellar evolutionary calculations based on the mixing-length theory can be confirmed by hydrodynamic simulations. Methods: We used a multidimensional Eulerian hydrodynamics code based on state-of-the-art numerical techniques to simulate the evolution of the helium core of a 1.25 M⊙ Pop I star. Results: Our three-dimensional hydrodynamic simulations of the evolution of a star during the peak of the core helium flash do not show any explosive behavior. The convective flow patterns developing in the three-dimensional models are structurally different from those of the corresponding two-dimensional models, and the typical convective velocities are lower than those found in their two-dimensional counterparts. Three-dimensional models also tend to agree more closely with the predictions of mixing length theory. Our hydrodynamic simulations show the turbulent entrainment that leads to a growth of the convection zone on a dynamic time scale. In contrast to mixing length theory, the outer part of the convection zone is characterized by a subadiabatic temperature gradient.

  18. Relative translucency of six all-ceramic systems. Part II: core and veneer materials.

    Science.gov (United States)

    Heffernan, Michael J; Aquilino, Steven A; Diaz-Arnold, Ana M; Haselton, Debra R; Stanford, Clark M; Vargas, Marcos A

    2002-07-01

    STATEMENT OF PROBLEM All-ceramic core materials with various strengthening compositions have a range of translucencies. It is unknown whether translucency differs when all-ceramic materials are fabricated similarly to the clinical restoration with a veneered core material. This study compared the translucency of 6 all-ceramic materials veneered and glazed at clinically appropriate thicknesses. Core specimens (n = 5 per group) of Empress dentin, Empress 2 dentin, In-Ceram Alumina, In-Ceram Spinell, In-Ceram Zirconia, and Procera AllCeram were fabricated as described in Part I of this study and veneered with their corresponding dentin porcelain to a final thickness of 1.47 +/- 0.01 mm. These specimens were compared with veneered Vitadur Alpha opaque dentin (as a standard), a clear glass disc (positive control), and a high-noble metal-ceramic alloy (Porc. 52 SF) veneered with Vitadur Omega dentin (negative control). Specimen reflectance was measured with an integrating sphere attached to a spectrophotometer across the visible spectrum (380 to 700 nm); 0-degree illumination and diffuse viewing geometry were used. Measurements were repeated after a glazing cycle. Contrast ratios were calculated from the luminous reflectance (Y) of the specimens with a black (Yb) and a white backing (Yw) to give Yb/Yw with CIE illuminant D65 and a 2-degree observer function (0.0 = transparent, 1.0 = opaque). One-way analysis of variance and Tukey's multiple-comparison test were used to analyze the data (Pceramic systems tested when they were veneered (Pceramic systems tested. Such variability may affect their ability to match natural teeth. The glazing cycle resulted in decreased opacity for all test materials except the completely opaque In-Ceram Zirconia and metal-ceramic specimens.

  19. LIDAR TS for ITER core plasma. Part II: simultaneous two wavelength LIDAR TS

    Science.gov (United States)

    Gowers, C.; Nielsen, P.; Salzmann, H.

    2017-12-01

    We have shown recently, and in more detail at this conference (Salzmann et al) that the LIDAR approach to ITER core TS measurements requires only two mirrors in the inaccessible port plug area of the machine. This leads to simplified and robust alignment, lower risk of mirror damage by plasma contamination and much simpler calibration, compared with the awkward and vulnerable optical geometry of the conventional imaging TS approach, currently under development by ITER. In the present work we have extended the simulation code used previously to include the case of launching two laser pulses, of different wavelengths, simultaneously in LIDAR geometry. The aim of this approach is to broaden the choice of lasers available for the diagnostic. In the simulation code it is assumed that two short duration (300 ps) laser pulses of different wavelengths, from an Nd:YAG laser are launched through the plasma simultaneously. The temperature and density profiles are deduced in the usual way but from the resulting combined scattered signals in the different spectral channels of the single spectrometer. The spectral response and quantum efficiencies of the detectors used in the simulation are taken from catalogue data for commercially available Hamamatsu MCP-PMTs. The response times, gateability and tolerance to stray light levels of this type of photomultiplier have already been demonstrated in the JET LIDAR system and give sufficient spatial resolution to meet the ITER specification. Here we present the new simulation results from the code. They demonstrate that when the detectors are combined with this two laser, LIDAR approach, the full range of the specified ITER core plasma Te and ne can be measured with sufficient accuracy. So, with commercially available detectors and a simple modification of a Nd:YAG laser similar to that currently being used in the design of the conventional ITER core TS design mentioned above, the ITER requirements can be met.

  20. Loss-of-function of OsSTN8 suppresses the photosystem II core protein phosphorylation and interferes with the photosystem II repair mechanism in rice (Oryza sativa).

    Science.gov (United States)

    Nath, Krishna; Poudyal, Roshan Sharma; Eom, Joon-Seob; Park, Yu Shin; Zulfugarov, Ismayil S; Mishra, Sujata R; Tovuu, Altanzaya; Ryoo, Nayeoon; Yoon, Ho-Sung; Nam, Hong Gil; An, Gynheung; Jeon, Jong-Seong; Lee, Choon-Hwan

    2013-11-01

    STN8 kinase is involved in photosystem II (PSII) core protein phosphorylation (PCPP). To examine the role of PCPP in PSII repair during high light (HL) illumination, we characterized a T-DNA insertional knockout mutant of the rice (Oryza sativa) STN8 gene. In this osstn8 mutant, PCPP was significantly suppressed, and the grana were thin and elongated. Upon HL illumination, PSII was strongly inactivated in the mutants, but the D1 protein was degraded more slowly than in wild-type, and mobilization of the PSII supercomplexes from the grana to the stromal lamellae for repair was also suppressed. In addition, higher accumulation of reactive oxygen species and preferential oxidation of PSII reaction center core proteins in thylakoid membranes were observed in the mutants during HL illumination. Taken together, our current data show that the absence of STN8 is sufficient to abolish PCPP in osstn8 mutants and to produce all of the phenotypes observed in the double mutant of Arabidopsis, indicating the essential role of STN8-mediated PCPP in PSII repair. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  1. Fukushima Daiichi Unit 1 Uncertainty Analysis-Exploration of Core Melt Progression Uncertain Parameters-Volume II.

    Energy Technology Data Exchange (ETDEWEB)

    Denman, Matthew R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    Sandia National Laboratories (SNL) has conducted an uncertainty analysi s (UA) on the Fukushima Daiichi unit (1F1) accident progression wit h the MELCOR code. Volume I of the 1F1 UA discusses the physical modeling details and time history results of the UA. Volume II of the 1F1 UA discusses the statistical viewpoint. The model used was developed for a previous accident reconstruction investigation jointly sponsored by the US Department of Energy (DOE) and Nuclear Regulatory Commission (NRC). The goal of this work was to perform a focused evaluation of uncertainty in core damage progression behavior and its effect on key figures - of - merit (e.g., hydrogen production, fraction of intact fuel, vessel lower head failure) and in doing so assess the applicability of traditional sensitivity analysis techniques .

  2. SIMMER-II: A computer program for LMFBR disrupted core analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bohl, W.R.; Luck, L.B.

    1990-06-01

    SIMMER-2 (Version 12) is a computer program to predict the coupled neutronic and fluid-dynamics behavior of liquid-metal fast reactors during core-disruptive accident transients. The modeling philosophy is based on the use of general, but approximate, physics to represent interactions of accident phenomena and regimes rather than a detailed representation of specialized situations. Reactor neutronic behavior is predicted by solving space (r,z), energy, and time-dependent neutron conservation equations (discrete ordinates transport or diffusion). The neutronics and the fluid dynamics are coupled via temperature- and background-dependent cross sections and the reactor power distribution. The fluid-dynamics calculation solves multicomponent, multiphase, multifield equations for mass, momentum, and energy conservation in (r,z) or (x,y) geometry. A structure field with nine density and five energy components; a liquid field with eight density and six energy components; and a vapor field with six density and on energy component are coupled by exchange functions representing a modified-dispersed flow regime with a zero-dimensional intra-cell structure model.

  3. Validation of the REBUS-3/RCT methodologies for EBR-II core-follow analysis

    Energy Technology Data Exchange (ETDEWEB)

    McKnight, R.D.

    1992-01-01

    One of the many tasks to be completed at EBR-2/FCF (Fuel Cycle Facility) regarding fuel cycle closure for the Integral Fast Reactor (IFR) is to develop and install the systems to be used for fissile material accountancy and control. The IFR fuel cycle and pyrometallurgical process scheme determine the degree of actinide of actinide buildup in the reload fuel assemblies. Inventories of curium, americium and neptunium in the fuel will affect the radiation and thermal environmental conditions at the fuel fabrication stations, the chemistry of reprocessing, and the neutronic performance of the core. Thus, it is important that validated calculational tools be put in place for accurately determining isotopic mass and neutronic inputs to FCF for both operational and material control and accountancy purposes. The primary goal of this work is to validate the REBUS-2/RCT codes as tools which can adequately compute the burnup and isotopic distribution in binary- and ternary-fueled Mark-3, Mark-4, and Mark-5 subassemblies. 6 refs.

  4. Key cofactors of photosystem II cores from four organisms identified by 1.7-K absorption, CD and MCD.

    Science.gov (United States)

    Arsköld, Sindra Peterson; Smith, Paul J; Shen, Jian-Ren; Pace, Ron J; Krausz, Elmars

    2005-06-01

    Active Photosystem II (PS II) cores were prepared from spinach, pea, Synechocystis PCC 6803, and Thermosynechococcus vulcanus, the latter of which has been structurally determined [Kamiya and Shen (2003) Proc Natl Acad Sci USA 100: 98-103]. Electrochromic shifts resulting from QA reduction by 1.7-K illumination were recorded, and the Qx and Qy absorption bands of the redox-active pheophytin a thus identified in the different organisms. The Qx transition is approximately 3 nm (100 cm-1) to higher energy in cyanobacteria than in the plants. The predominant Qy shift appears in the range 683-686 nm depending on species, and does not appear to have a systematic shift. Low-temperature absorption, circular dichroism (CD) and magnetic circular dichroism (MCD) spectra of the chlorophyll Qy region are very similar in spinach and pea, but vary in cyanobacteria. We assigned CP43 and CP47 trap-chlorophyll absorption features in all species, as well as a P680 transition. Each absorption identified has an area of one chlorophyll a. The MCD deficit, introduced previously for spinach as an indicator of P680 activity, occurs in the same spectral region and has the same area in all species, pointing to a robustness of this as a signature for P680. MCD and CD characteristics point towards a significant variance in P680 structure between cyanobacteria, thermophilic cyanobacteria, and higher plants.

  5. Ferromagnetic coupling in trinuclear, partial cubane Cu(II) complexes with a micro(3)-OH core: magnetostructural correlations.

    Science.gov (United States)

    Sarkar, Biswarup; Ray, Mau Sinha; Li, Yi-Zhi; Song, You; Figuerola, Albert; Ruiz, Eliseo; Cirera, Jordi; Cano, Joan; Ghosh, Ashutosh

    2007-01-01

    Three new trinuclear copper(II) complexes, [(CuL(1))(3)(micro(3)-OH)][ClO(4)](2).3 H(2)O (1), [(CuL(2))(3)(micro(3)-OH)][ClO(4)](2).H(2)O (2), and [(CuL(3))(3)(micro(3)-OH)][ClO(4)](2).7 H(2)O (3) have been synthesized from the three tridentate Schiff bases HL(1), HL(2), and HL(3) (HL(1)=6- aminomethyl-3-methyl-1-phenyl-4-azahex-2-en-1-one, HL(2)=6-aminoethyl-3-methyl-1-phenyl-4-azahex-2-en-1-one, and HL(3)=6-aminodimethyl-3-methyl-1-phenyl-4-azahex-2-en-1-one). They have been characterized by X-ray crystallography and IR and UV spectroscopy, and their magnetic properties have been investigated. All the compounds contain a partial cubane [Cu(3)O(4)] core consisting of the trinuclear unit [(CuL)(3)(micro(3)-OH)](2+), perchlorate ions, and water molecules. In each of the complexes, the copper atoms are five-coordinate with a distorted square-pyramidal geometry except complex 1, in which one of the Cu(II) of the trinuclear unit is weakly coordinated to one of the perchlorate ions. Magnetic measurements performed in SQUID MPMS-XL7 using polycrystalline samples at an applied field of 2 kOe indicate a global intramolecular ferromagnetic coupling. Magnetostructural correlations have been calculated on the basis of theoretical models without symmetry restriction. Continuous shape measurements are an appropriate tool for establishing the degree of distortion of the Cu(II) from square-planar geometry. Structural, theoretical, and experimental magnetic data indicate that the higher the degree of distortion, the greater the ferromagnetic coupling.

  6. Process Fragments

    Science.gov (United States)

    Eberle, Hanna; Unger, Tobias; Leymann, Frank

    The concepts presented in this paper are motivated by the assumption that process knowledge is distributed knowledge and not completely known just by one person. Driven by this assumption we deal in this paper with the following questions: How can partial process knowledge be represented? How can this partial knowledge be used to define something more complete? To use higher level artefacts as building blocks to new applications has a long tradition in software engineering to increase flexibility and reduce modeling costs. In this paper we take a first step in applying this concept to processes, by defining process building blocks and operations which compose process building blocks. The building blocks will be referred to as process fragments in the following. The process fragment composition may take place either at design or runtime of the process. The design time approach reduces design costs by reusing artefacts. However the runtime fragment composition approach realizes high flexibility due to the possibility in the dynamic selection of the fragments to be composed. The contribution of this work lies in a fragment definition that enables the fragment modeler to represent his 'local' and fragmentary knowledge in a formal way and which allows fragment models to be composed.

  7. Interfacial charge separation and recombination in InP and quasi-type II InP/CdS core/shell quantum dot-molecular acceptor complexes.

    Science.gov (United States)

    Wu, Kaifeng; Song, Nianhui; Liu, Zheng; Zhu, Haiming; Rodríguez-Córdoba, William; Lian, Tianquan

    2013-08-15

    Recent studies of group II-VI colloidal semiconductor heterostuctures, such as CdSe/CdS core/shell quantum dots (QDs) or dot-in-rod nanorods, show that type II and quasi-type II band alignment can facilitate electron transfer and slow down charge recombination in QD-molecular electron acceptor complexes. To explore the general applicability of this wave function engineering approach for controlling charge transfer properties, we investigate exciton relaxation and dissociation dynamics in InP (a group III-V semiconductor) and InP/CdS core/shell (a heterostructure beween group III-V and II-VI semiconductors) QDs by transient absorption spectroscopy. We show that InP/CdS QDs exhibit a quasi-type II band alignment with the 1S electron delocalized throughout the core and shell and the 1S hole confined in the InP core. In InP-methylviologen (MV(2+)) complexes, excitons in the QD can be dissociated by ultrafast electron transfer to MV(2+) from the 1S electron level (with an average time constant of 11.4 ps) as well as 1P and higher electron levels (with a time constant of 0.39 ps), which is followed by charge recombination to regenerate the complex in its ground state (with an average time constant of 47.1 ns). In comparison, InP/CdS-MV(2+) complexes show similar ultrafast charge separation and 5-fold slower charge recombination rates, consistent with the quasi-type II band alignment in these heterostructures. This result demonstrates that wave function engineering in nanoheterostructures of group III-V and II-VI semiconductors provides a promising approach for optimizing their light harvesting and charge separation for solar energy conversion applications.

  8. Interface control of electronic and optical properties in IV-VI and II-VI core/shell colloidal quantum dots: a review.

    Science.gov (United States)

    Jang, Youngjin; Shapiro, Arthur; Isarov, Maya; Rubin-Brusilovski, Anna; Safran, Aron; Budniak, Adam K; Horani, Faris; Dehnel, Joanna; Sashchiuk, Aldona; Lifshitz, Efrat

    2017-01-17

    Semiconductor colloidal quantum dots (CQDs) have attracted vast scientific and technological interest throughout the past three decades, due to the unique tuneability of their optoelectronic properties by variation of size and composition. However, the nanoscale size brings about a large surface-to-bulk volume ratio, where exterior surfaces have a pronounced influence on the chemical stability and on the physical properties of the semiconductor. Therefore, numerous approaches have been developed to gain efficient surface passivation, including a coverage by organic or inorganic molecular surfactants as well as the formation of core/shell heterostructures (a semiconductor core epitaxially covered by another semiconductor shell). This review focuses on special designs of core/shell heterostructures from the IV-VI and II-VI semiconductor compounds, and on synthetic approaches and characterization of the optical properties. Experimental observations revealed the formation of core/shell structures with type-I or quasi-type-II band alignment between the core and shell constituents. Theoretical calculations of the electronic band structures, which were also confirmed by experimental work, exposed surplus electronic tuning (beyond the radial diameter) with adaptation of the composition and control of the interface properties. The studies also considered strain effects that are created between two different semiconductors. It was disclosed experimentally and theoretically that the strain can be released via the formation of alloys at the core-shell interface. Overall, the core/shell and core/alloyed-shell heterostructures showed enhancement in luminescence quantum efficiency with respect to that of pure cores, extended lifetime, uniformity in size and in many cases good chemical sustainability under ambient conditions.

  9. Two emissive-magnetic composite platforms for Hg(II) sensing and removal: The combination of magnetic core, silica molecular sieve and rhodamine chemosensors.

    Science.gov (United States)

    Mao, Hanping; Liu, Zhongshou

    2018-01-15

    In this paper, a composite sensing platform for Hg(II) optical sensing and removal was designed and reported. A core-shell structure was adopted, using magnetic Fe3O4 nanoparticles as the core, silica molecular sieve MCM-41 as the shell, respectively. Two rhodamine derivatives were synthesized as chemosensor and covalently immobilized into MCM-41 tunnels. Corresponding composite samples were characterized with SEM/TEM images, XRD analysis, IR spectra, thermogravimetry and N2 adsorption/desorption analysis, which confirmed their core-shell structure. Their emission was increased by Hg(II), showing emission turn on effect. High selectivity, linear working curves and recyclability were obtained from these composite samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Tropical forest fragmentation affects floral visitors but not the structure of individual-based palm-pollinator networks.

    Directory of Open Access Journals (Sweden)

    Wesley Dáttilo

    Full Text Available Despite increasing knowledge about the effects of habitat loss on pollinators in natural landscapes, information is very limited regarding the underlying mechanisms of forest fragmentation affecting plant-pollinator interactions in such landscapes. Here, we used a network approach to describe the effects of forest fragmentation on the patterns of interactions involving the understory dominant palm Astrocaryum mexicanum (Arecaceae and its floral visitors (including both effective and non-effective pollinators at the individual level in a Mexican tropical rainforest landscape. Specifically, we asked: (i Does fragment size affect the structure of individual-based plant-pollinator networks? (ii Does the core of highly interacting visitor species change along the fragmentation size gradient? (iii Does forest fragment size influence the abundance of effective pollinators of A. mexicanum? We found that fragment size did not affect the topological structure of the individual-based palm-pollinator network. Furthermore, while the composition of peripheral non-effective pollinators changed depending on fragment size, effective core generalist species of pollinators remained stable. We also observed that both abundance and variance of effective pollinators of male and female flowers of A. mexicanum increased with forest fragment size. These findings indicate that the presence of effective pollinators in the core of all forest fragments could keep the network structure stable along the gradient of forest fragmentation. In addition, pollination of A. mexicanum could be more effective in larger fragments, since the greater abundance of pollinators in these fragments may increase the amount of pollen and diversity of pollen donors between flowers of individual plants. Given the prevalence of fragmentation in tropical ecosystems, our results indicate that the current patterns of land use will have consequences on the underlying mechanisms of pollination in

  11. Tropical forest fragmentation affects floral visitors but not the structure of individual-based palm-pollinator networks.

    Science.gov (United States)

    Dáttilo, Wesley; Aguirre, Armando; Quesada, Mauricio; Dirzo, Rodolfo

    2015-01-01

    Despite increasing knowledge about the effects of habitat loss on pollinators in natural landscapes, information is very limited regarding the underlying mechanisms of forest fragmentation affecting plant-pollinator interactions in such landscapes. Here, we used a network approach to describe the effects of forest fragmentation on the patterns of interactions involving the understory dominant palm Astrocaryum mexicanum (Arecaceae) and its floral visitors (including both effective and non-effective pollinators) at the individual level in a Mexican tropical rainforest landscape. Specifically, we asked: (i) Does fragment size affect the structure of individual-based plant-pollinator networks? (ii) Does the core of highly interacting visitor species change along the fragmentation size gradient? (iii) Does forest fragment size influence the abundance of effective pollinators of A. mexicanum? We found that fragment size did not affect the topological structure of the individual-based palm-pollinator network. Furthermore, while the composition of peripheral non-effective pollinators changed depending on fragment size, effective core generalist species of pollinators remained stable. We also observed that both abundance and variance of effective pollinators of male and female flowers of A. mexicanum increased with forest fragment size. These findings indicate that the presence of effective pollinators in the core of all forest fragments could keep the network structure stable along the gradient of forest fragmentation. In addition, pollination of A. mexicanum could be more effective in larger fragments, since the greater abundance of pollinators in these fragments may increase the amount of pollen and diversity of pollen donors between flowers of individual plants. Given the prevalence of fragmentation in tropical ecosystems, our results indicate that the current patterns of land use will have consequences on the underlying mechanisms of pollination in remnant forests.

  12. Effect of core-shell copper oxide nanoparticles on cell culture morphology and photosynthesis (photosystem II energy distribution) in the green alga, Chlamydomonas reinhardtii.

    Science.gov (United States)

    Saison, Cyril; Perreault, François; Daigle, Jean-Christophe; Fortin, Claude; Claverie, Jérôme; Morin, Mario; Popovic, Radovan

    2010-01-31

    The effect of core-shell copper oxide nanoparticles with sizes smaller than 100 nm on cellular systems is still not well understood. Documenting these effects is pressing since core-shell copper oxide nanoparticles are currently components of pigments used frequently as antifouling paint protecting boats from crustacean, weed and slime fouling. However, the use of such paints may induce strong deteriorative effects on different aquatic trophic levels that are not the intended targets. Here, the toxic effect of core-shell copper oxide nanoparticles on the green alga, Chlamydomonas reinhardtii was investigated with regards to the change of algal cellular population structure, primary photochemistry of photosystem II and reactive oxygen species formation. Algal cultures were exposed to 0.004, 0.01 and 0.02 g/l of core-shell copper oxide nanoparticles for 6h and a change in algal population structure was observed, while the formation of reactive oxygen species was determined using the 2',7'-dichlorodihydrofluorescein diacetate marker measured by flow cytometry. For the study of the photosystem II primary photochemistry we investigated the change in chlorophyll a rapid rise of fluorescence. We found that core-shell copper oxide nanoparticles induced cellular aggregation processes and had a deteriorative effect on chlorophyll by inducing the photoinhibition of photosystem II. The inhibition of photosynthetic electron transport induced a strong energy dissipation process via non-photochemical pathways. The deterioration of photosynthesis was interpreted as being caused by the formation of reactive oxygen species induced by core-shell copper oxide nanoparticles. However, no formation of reactive oxygen species was observed when C. reinhardtii was exposed to the core without the shell or to the shell only. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  13. A new insight on the core-shell structure of zerovalent iron nanoparticles and its application for Pb(II) sequestration.

    Science.gov (United States)

    Zhang, Yalei; Su, Yiming; Zhou, Xuefei; Dai, Chaomeng; Keller, Arturo A

    2013-12-15

    Nanoscale zerovalent iron (nZVI) has shown a high efficacy for removing heavy metals from liquid solution. However, its removal capacity has not been fully explored due to its common shell composition (FeOOH). In this study, a much higher removal capacity of Pb(II) is observed (1667 mg Pb(II)/gFe), which is over 100% higher than the highest removal capacity of nZVI reported before. High-resolution X-ray photoelectron spectroscopy (HR-XPS) reveals that through restricting the dehydration process of Fe(OH)3, nZVI can acquire a unique shell, which is composed of 45.5% Fe(OH)3 and 54.5% FeOOH. The presence of Fe(OH)3 suppresses the reduction of Pb(II), but greatly promotes the co-precipitation and adsorption of Pb(II). Combining the ratio of Fe-released to Pb-immobilized and the result of HR-XPS, a reaction between Fe(0) core, Fe(OH)3, and Pb(II) is proposed. The Fe released from the Fe(0) core leads to the core depletion, observed by transmission electron microscopy (TEM) under high Pb(II) loading. While temperature has little influence on the removal capacity, pH affects the removal capacity greatly. pH4.5 promotes Pb(II) adsorption. Given the high Pb removal capacity via the Fe(OH)3 shell, nZVI can be used to remedy Pb(II) contamination. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Ionic fragmentation of a natural product, limonene (C{sub 10}H{sub 16}), following core [C 1s] photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Castilho, R.B. de [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Cidade Universitaria, Ilha do Fundao, 21949-900 Rio de Janeiro, RJ (Brazil); Nunez, C.V. [Instituto Nacional de Pesquisas da Amazonia, INPA, Manaus, Amazonas (Brazil); Coutinho, L.H. [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Cidade Universitaria, Ilha do Fundao, 21949-900 Rio de Janeiro, RJ (Brazil); Lago, A.F. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Bernini, R.B. [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Cidade Universitaria, Ilha do Fundao, 21949-900 Rio de Janeiro, RJ (Brazil); Souza, G.G.B. de [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Cidade Universitaria, Ilha do Fundao, 21949-900 Rio de Janeiro, RJ (Brazil)], E-mail: gerson@iq.ufrj.br

    2007-03-15

    Photoionization of the limonene [C{sub 10}H{sub 16}] molecule was studied for the first time following C 1s ionization, using synchrotron radiation and time-of-fight mass spectrometry. As a reference for further analysis of the photon induced fragmentation of the limonene molecule, the He(I) mass spectrum was also obtained. Previously unreported singly charged species have been observed at 310 eV: H{sup +}, C{sup +}, CH{sup +}, CH{sub 2}{sup +}, CH{sub 3}{sup +}. A close similarity has been observed between the high photon energy mass spectrum and the standard electron impact mass spectrum of limonene, obtained at 70 eV. In particular, the base peak [C{sub 5}H{sub 8}{sup +}, m/q = 68], known to result from a Retro Diels-Alder reaction, remains the same in both cases. Approximate values for the mean kinetic energy were determined for all ionic species.

  15. Chameleon fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov [Institute for the Early Universe, Ewha University, International Education, Building #601, 11-1, Daehyun-Dong Seodaemun-Gu, Seoul 120-750 (Korea, Republic of)

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  16. Correlated behavior of the EPR signal of cytochrome b-559 heme Fe(III) ligated by OH- and the multiline signal of the Mn cluster in PS-II membrane fragments.

    Science.gov (United States)

    Fiege, R; Shuvalov, V A

    1996-05-27

    EPR signals of Cyt b-559 heme Fe(III) ligated by OH- and the multiline signal of the Mn cluster in PS-II membrane fragments have been investigated. In 2,3-dicyano-5,6-dichloro-p-benzoquinone-oxidized PS-II membrane fragments the light-induced decrease of the EPR signal of the heme Fe(III)-OH- is accompanied by the appearance of the EPR multiline signal of the Mn cluster. Addition of F- ions, which act as a stronger ligand for heme Fe(III) than OH-, decreases to the same extent the dark- and light-induced signal of the heme Fe(III)-OH- and the light-induced multiline signal of the Mn cluster. These results are discussed in terms of the light-induced formation of a bound OH' radical shared between the Cyt b-559 heme Fe and the Mn cluster as a first step of water oxidation.

  17. An Assessment of Southern Ocean Water Masses and Sea Ice During 1988-2007 in a Suite of Interannual CORE-II Simulations

    Science.gov (United States)

    Downes, Stephanie M.; Farneti, Riccardo; Uotila, Petteri; Griffies, Stephen M.; Marsland, Simon J.; Bailey, David; Behrens, Erik; Bentsen, Mats; Bi, Daohua; Biastoch, Arne; hide

    2015-01-01

    We characterise the representation of the Southern Ocean water mass structure and sea ice within a suite of 15 global ocean-ice models run with the Coordinated Ocean-ice Reference Experiment Phase II (CORE-II) protocol. The main focus is the representation of the present (1988-2007) mode and intermediate waters, thus framing an analysis of winter and summer mixed layer depths; temperature, salinity, and potential vorticity structure; and temporal variability of sea ice distributions. We also consider the interannual variability over the same 20 year period. Comparisons are made between models as well as to observation-based analyses where available. The CORE-II models exhibit several biases relative to Southern Ocean observations, including an underestimation of the model mean mixed layer depths of mode and intermediate water masses in March (associated with greater ocean surface heat gain), and an overestimation in September (associated with greater high latitude ocean heat loss and a more northward winter sea-ice extent). In addition, the models have cold and fresh/warm and salty water column biases centred near 50 deg S. Over the 1988-2007 period, the CORE-II models consistently simulate spatially variable trends in sea-ice concentration, surface freshwater fluxes, mixed layer depths, and 200-700 m ocean heat content. In particular, sea-ice coverage around most of the Antarctic continental shelf is reduced, leading to a cooling and freshening of the near surface waters. The shoaling of the mixed layer is associated with increased surface buoyancy gain, except in the Pacific where sea ice is also influential. The models are in disagreement, despite the common CORE-II atmospheric state, in their spatial pattern of the 20-year trends in the mixed layer depth and sea-ice.

  18. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  19. Theoretical study on photophysical properties of Pt(II) triarylborons with a 2,2-bpy core derivatives.

    Science.gov (United States)

    Liu, Yan; Yang, Guochun; Sun, Shiling; Si, Yanling; Su, Zhongmin

    2013-07-01

    The photophysical properties of the linear and v shaped Pt(II) triarylborons with a 2,2'-bpy core derivatives have been investigated by density functional theory (DFT) method. The calculated electronic absorption wavelengths are in agreement with experimental ones, which can be described as a mixed transition of intra-ligand charge transfer (ILCT), ligand to ligand charge-transfer (LLCT), and metal-to-ligand charge transfer (MLCT). It is found that the MLCT transition is mainly responsible for the low-energy absorption band with relative smaller oscillator strength, while the high-energy absorption band mainly derives from ILCT and LLCT transition. Moreover, the electron absorption wavelengths are not only dependent on the position of the Ph-BMes2 but also on the electron-accepting ability of the acceptor groups. The first hyperpolarizability values of the v shaped complexes are larger than that of the linear shape complex, which indicates that larger intramolecular charge transfer for the v shaped complexes will come into being under the external electric field. Moreover, these complexes exhibit two-dimensional second-order nonlinear optical (NLO) character. Thus, the studied complexes have a possibility to be excellent second-order NLO materials. Based on the two-level model, the variation of first hyperpolarizabilities of the studied complexes can be explained by the combined effect of the difference between the ground state and excited state dipole moment, the oscillator strength, and the cube of the transition energy. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. A windmill-shaped hexacopper(II) molecule built up by template core-controlled expansion of diaquatetrakis(mu2-adeninato-N3,N9)dicopper(II) with aqua(oxydiacetato)copper(II).

    Science.gov (United States)

    González-Pérez, Josefa María; Alarcón-Payer, Carolina; Castiñeiras, Alfonso; Pivetta, Tiziana; Lezama, Luis; Choquesillo-Lazarte, Duane; Crisponi, Guido; Niclós-Gutiérrez, Juan

    2006-01-23

    The windmill-shaped hexanuclear copper(II) cluster {(H(2)O)(2)Cu(2)(mu(3)-(Ade)(4)[Cu(oda)(H(2)O)](4)}.6H(2)O (1-o) has been synthesized in aqueous medium by in situ core-controlled expansion of the neutral building block Cu(2)(mu(2)-N3,N9-Ade)(4)(H(2)O)(2) (2) with Cu(oda)(H(2)O) (3-o) (Ade = adeninato(1-) and oda = oxydiacetato(2-) ligands). Crystal data for 2-b (2.5H(2)O): triclinic, space group P(-)1; a = 9.374(1), b = 9.440(1), c = 10.326(1) A; alpha = 78.72(1), beta = 76.77(1), gamma = 63.51(1) degrees ; final R(1) = 0.059; T = 100(2) K. Crystal data for 1-o: monoclinic, space group P2(1)/n; a = 15.203(2), b = 10.245(1), c = 19.094(2) A; beta = 101.61(1) degrees ; final R(1) = 0.049; T = 293(2) K. The X-shaped hexanuclear molecule consists of a central core (2) and four terminal arms (3-o) linked together by bridging mu(3)-N3,N7,N9-Ade ligands. There are three crystallographic independent metal atoms (two terminals, one central). All Cu(II) atoms exhibit a 4 + 1 coordination, of which one is an aqua apical ligand. The basal coordination sets complete the CuN(4) + O or CuO(3)N + O chromophores for the central or terminal metal atoms, respectively. Thermal stability and spectral and magnetic properties were also studied. Analogous compounds to 1-o with tridentate or tripodal tetradentate ligands L(2-), instead of oda, have also been synthesized.

  1. Achieving enhanced visible-light-driven photocatalysis using type-II NaNbO3/CdS core/shell heterostructures.

    Science.gov (United States)

    Kumar, Sandeep; Khanchandani, Sunita; Thirumal, Meganathan; Ganguli, Ashok K

    2014-08-13

    Expanding the light-harvesting range and suppressing the quick recombination of photogenerated charge carriers are of paramount significance in the field of photocatalysis. One possible approach to achieve wide absorption range is to synthesize type-II core/shell heterostructures. In addition, this system also shows great promise for fast separation of charge carriers and low charge recombination rate. Herein, following the surface functionalization method using 3-mercaptopropionic acid (MPA) as a surface functionalizing agent, we report on designing NaNbO3/CdS type-II core/shell heterostructures with an absorption range extending to visible range and explore the opportunity toward degradation of methylene blue (MB) dye as a model pollutant under visible light irradiation. Characterizations including X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), UV-vis diffuse reflectance spectrum (DRS), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy support the growth of CdS shell onto NaNbO3 nanorods. The resulting core/shell heterostructures unveiled high surface areas, enhanced light harvesting, and appreciably increased photocatalytic activity toward MB degradation compared to individual counterparts and the photocatalytic standard, Degussa P25, under visible light irradiation. The remarkably enhanced photocatalytic activity of core/shell heterostructures could be interpreted in terms of efficient charge separation owing to core/shell morphology and resulting type-II band alignment between NaNbO3 and CdS, which creates a step-like radial potential favoring the localization of one of the carriers in the core and the other in the shell. A plausible mechanism for the degradation of MB dye over NaNbO3/CdS core/shell heterostructures is also elucidated using active species scavenger studies. Our findings imply that hydroxyl radicals (OH(•)) play a crucial role in dictating the degradation

  2. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2017-01-01

    The PhD project Bespoke Fragments is investigating the space emerging in the exploration of the relationship between digital drawing and fabrication, and the field of materials and their properties and capacities. Through a series of different experiments, the project situates itself in a shuttling...... tangible experiments, the project discusses materiality and digitally controlled fabrication tools as a expansion of the architect’s tool box and workflow. Bespoke Fragments considers this expansion as an opportunity to establish a connection between forms of digital drawing and the specificities...... of materials. Through that connection, the project seeks to use the realisation to generate developments and findings and, through an iterative mode of thinking, establish a dialogue between drawing, materials, and fabrication. The use of digital fabrication tools through digital drawing opens up a new...

  3. Architectural fragments

    DEFF Research Database (Denmark)

    Bang, Jacob Sebastian

    2018-01-01

    . I try to invent the ways of drawing the models - that decode and unfold them into architectural fragments- into future buildings or constructions in the landscape. [1] Luigi Moretti: Italian architect, 1907 - 1973 [2] Man Ray: American artist, 1890 - 1976. in 2015, I saw the wonderful exhibition......I have created a large collection of plaster models: a collection of Obstructions, errors and opportunities that may develop into architecture. The models are fragments of different complex shapes as well as more simple circular models with different profiling and diameters. In this contect I have...... been studying Luigi Moretti's [1] plastermodel - "the Model of the inner spaces of the Saint Maria of the Divine Providence" - in which context I see my own models. In 1934, Man Ray [2] photographed mathematical rmodels (in plaster) at the Henri Poincaré Institute in Paris and later used...

  4. NSGA-II Algorithm with a Local Search Strategy for Multiobjective Optimal Design of Dry-Type Air-Core Reactor

    Directory of Open Access Journals (Sweden)

    Chengfen Zhang

    2015-01-01

    Full Text Available Dry-type air-core reactor is now widely applied in electrical power distribution systems, for which the optimization design is a crucial issue. In the optimization design problem of dry-type air-core reactor, the objectives of minimizing the production cost and minimizing the operation cost are both important. In this paper, a multiobjective optimal model is established considering simultaneously the two objectives of minimizing the production cost and minimizing the operation cost. To solve the multi-objective optimization problem, a memetic evolutionary algorithm is proposed, which combines elitist nondominated sorting genetic algorithm version II (NSGA-II with a local search strategy based on the covariance matrix adaptation evolution strategy (CMA-ES. NSGA-II can provide decision maker with flexible choices among the different trade-off solutions, while the local-search strategy, which is applied to nondominated individuals randomly selected from the current population in a given generation and quantity, can accelerate the convergence speed. Furthermore, another modification is that an external archive is set in the proposed algorithm for increasing the evolutionary efficiency. The proposed algorithm is tested on a dry-type air-core reactor made of rectangular cross-section litz-wire. Simulation results show that the proposed algorithm has high efficiency and it converges to a better Pareto front.

  5. New core@shell nanogel based 2-acrylamido-2-methyl-1-propane sulfonic acid for preconcentration of Pb(II) from various water samples

    Science.gov (United States)

    Shoueir, Kamel Rizq; Akl, Magda Ali; Sarhan, Ali Ali; Atta, Ayman Mohamdy

    2017-11-01

    Poly(vinyl alcohol) core coated with poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co- N-isopropylacrylamide) shell to produce well-define PVA@P(AMPS-co-NIPAm) core shell nanogels with a core of 25 ± 0.5 nm and shell of 5 ± 0.5 nm. The synthetic approach was produced by a surfactant free emulsion polymerization (SFEP). The specific area was found to be 1685.8 m2/g. The nanogels were studied in a batch adsorption for removal of Pb(II) ions and characterized by SEM, TEM, TGA and BET measurements. The results showed that the adsorption equilibrium data fitted the Langmuir isotherm and the kinetic studies are well described by the pseudo-second-order kinetic model. The Pb(II) maximum adsorption was 510.2 (mg/g) for PVA@P(90AMPS-co-10NIPAm) (wt.: wt%). The PVA@P(AMPS-co-NIPAm) nanogels were applied for extracting of Pb(II) in real different environmental water samples successfully with high recoveries reaches 104.4%.

  6. Core and conal component analysis of pulsar B1237+25 - II. Investigation of the segregated modes

    NARCIS (Netherlands)

    Smith, E.; Rankin, J.; Mitra, D.

    2013-01-01

    Radio pulsar B1237+25 is the prime exemplar of a five-component profile indicating a core/double cone emission-beam structure. Here we conduct a pulse-sequence analysis of its three behaviours based on our earlier partial profile study in Paper I. Focusing on the core region, we find first that its

  7. Fragmentation based

    Directory of Open Access Journals (Sweden)

    Shashank Srivastava

    2014-01-01

    Gaining the understanding of mobile agent architecture and the security concerns, in this paper, we proposed a security protocol which addresses security with mitigated computational cost. The protocol is a combination of self decryption, co-operation and obfuscation technique. To circumvent the risk of malicious code execution in attacking environment, we have proposed fragmentation based encryption technique. Our encryption technique suits the general mobile agent size and provides hard and thorny obfuscation increasing attacker’s challenge on the same plane providing better performance with respect to computational cost as compared to existing AES encryption.

  8. Refactoring the six-gene photosystem II core in the chloroplast of the green algae Chlamydomonas reinhardtii

    DEFF Research Database (Denmark)

    Gimpel, Javier A.; Nour-Eldin, Hussam Hassan; Scranton, Melissa A.

    2016-01-01

    production, particularly under specific environmental conditions. PSII is a complex multisubunit enzyme with strong interdependence among its components. In this work, we have deleted the six core genes of PSII in the eukaryotic alga Chlamydomonas reinhardtii and refactored them in a single DNA construct....... Complementation of the knockout strain with the core PSII synthetic module from three different green algae resulted in reconstitution of photosynthetic activity to 85, 55, and 53% of that of the wild-type, demonstrating that the PSII core can be exchanged between algae species and retain function. The strains...

  9. New cyclic tetranuclear copper(II) complexes containing quadrilateral cores: Synthesis, structure, spectroscopy and their interactions with DNA in aqueous solution

    Science.gov (United States)

    Giri, Gopal C.; Haldar, Shobhraj; Ghosh, Aloke Kumar; Chowdhury, Priyanka; Carrella, Luca; Ghosh, Utpal; Bera, Manindranath

    2017-08-01

    Three new cyclic tetranuclear copper(II) complexes, Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrachloro)tetracopper(II)methanolhydrate (1·CH3OH·H2O), Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrathiocyanato)tetracopper(II) (2) and Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetraazido)tetracopper(II) (3) have been synthesized by exploiting the chelating ability and bridging potential of a carboxyamine functionalized tridentate ligand, HL (HL = 3-[(2-Pyridylmethyl)-amino]-propionic acid). Complexes 1, 2 and 3 have been synthesized by carrying out reaction of the ligand HL with stoichiometric amounts of CuCl2·2H2O, CuCl2·2H2O/NH4SCN, and CuCl2·2H2O/NaN3, respectively, in the presence of NMe4OH at ambient temperature. Various analytical techniques have been employed to characterize the complexes, including single crystal X-ray diffraction study of 1. Structures of complexes 2 and 3 have been optimized by DFT calculation at B3LYP/6-311G level. Analysis of X-ray crystal structure reveals that the metallic core of complex 1 contains four distorted square pyramidal Cu(II) ions. The Cu(II) ions in each complex are arranged at the corners of a quadrilateral showing a μ2:η1:η1syn-anti bidentate bridging mode of four carboxylate groups of L- ligands with each bridging between two Cu(II) ions. These complexes represent a new family of 16-MCCuII-4 metallocoronates with repeating -[CuIIsbnd Osbnd Csbnd O]- units. In aqueous solution (pH∼7.5), the interactions of complexes with DNA have been investigated by UV-Vis and fluorescence titration spectroscopy, and viscosity measurements.

  10. The Copper(II) Adduct of the Unstructured Region of the Amyloidogenic Fragment Derived from theHuman Prion Protein is Redox-Active at Physiological pH

    Energy Technology Data Exchange (ETDEWEB)

    Shearer,J.; Soh, P.

    2007-01-01

    Prion diseases are caused by the misfolding and aggregation of the prion protein (PrP). Herein we provide evidence that the Cu{sup II} adduct of the unstructured amyloidogenic fragment of the human PrP (PrP(91-126)) is redox active under physiological conditions. We have identified that the relevant high-affinity Cu{sup II} binding region of PrP(91-126) is contained between residues 106 and 114. Both [Cu{sup II}(PrP(91-126))] and [Cu{sup II}(PrP(106-114))] have Cu{sup II} K{sub d} values of {approx}90 {mu}M. Furthermore, the smaller PrP fragment PrP(106-114) coordinates Cu{sup II} producing an electronic absorption spectrum nearly identical with [Cu{sup II}(PrP(91-126))] ({lambda}{sub max} {approx}610 nm ({var_epsilon} {approx}125 M{sup -1} cm{sup -1})) suggesting a similar coordination environment for Cu{sup II}. Cu K-edge X-ray absorption spectroscopy (XAS) reveals a nearly identical CuN(N/O){sub 2}S coordination environment for these two metallopeptides (2N/O at {approx}1.97 {angstrom}; 1S at {approx}2.30 {angstrom}; 1 imidazole N at {approx}1.95 {angstrom}). Both display quasireversible Cu{sup II}/Cu{sup I} redox couples at {approx}-350 mV vs Ag/AgCl. ESI-MS indicates that both peptides will coordinate Cu{sup I}. However, XAS indicates differential coordination environments between [Cu{sup I}(PrP(91-126))] and [Cu{sup I}(PrP(106-114))]. These data indicate that [Cu{sup I}(PrP(91-126))] contains Cu in a four coordinate (N/O){sub 2}S{sub 2} environment with similar (N/O)-Cu bond distances (Cu-(N/O) r = 2.048(4) {angstrom}), while [Cu{sup I}(PrP(106-114))] contains Cu in a four coordinate (N/O){sub 2}S{sub 2} environment with differential (N/O)-Cu bond distances (Cu-(N/O) r{sub 1} = 2.057(6) {angstrom}; r{sub 2} = 2.159(3) {angstrom}). Despite the differential coordination environments both Cu-metallopeptides will catalytically reduce O{sub 2} to O{sub 2}{sup {sm_bullet}-} at comparable rates.

  11. Au-Ag Core-Shell Nanospheres for Surface-Enhanced Raman Scattering Detection of Sudan I and Sudan II in Chili Powder

    Directory of Open Access Journals (Sweden)

    Lu Pei

    2015-01-01

    Full Text Available Au-Ag core-shell (Au@Ag bimetallic nanospheres synthesized by a facile seed-growth method are proposed as a substrate for surface-enhanced Raman spectroscopy (SERS to detect azo-group dyes including Sudan I and Sudan II. Au@Ag nanospheres with a series of particle sizes (diameter: 30–120 nm and silver shell thicknesses (6–51 nm were synthesized and compared for their morphological and optical properties to obtain optimum enhancement effect. Normal Raman, SERS, infrared, and ultraviolet-visible were used to investigate the optical absorption properties of Sudan I and Sudan II as well as the enhancement mechanism of Au@Ag substrates. The nanospheres with particle size of 73 ± 6 nm in diameter and silver layer of 27 ± 2 nm resulted in the highest enhancement effect and could be used to detect Sudan I and Sudan II standard solutions at levels as low as 0.4 and 0.1 mg/L, respectively. Moreover, Sudan I and Sudan II in chili powder could be detected at 0.6 and 0.4 mg/kg, respectively. Sudan I and Sudan II with similar structures in complicated food matrices could be distinguished through applying principal component analysis, indicating good selectivity of the SERS method for detection of banned additives in food stuffs at trace levels.

  12. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2016-01-01

    the digital environment with the reality of materials – and use realisation and materialisation to generate architectural developments and findings through an iterative mode of thinking about the dialogue between drawing, materials and fabrication. The control of fabrication tools through digital drawing......The Ph.D. -project Bespoke Fragments seeks to explore and utilise the space emerging between the potentials of digital drawing and fabrication and the field of materials and their properties and capacities. Within this span, the project is situated in a shuttling between the virtual and the actual......, investigating levels of control and uncertainty encountering with these. Through tangible experiments, the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect's digital drawing and workflow. The project sees this expansion as an opportunity to connect...

  13. Framing Fragmentation

    DEFF Research Database (Denmark)

    Bundgaard, Charlotte

    2009-01-01

    Contemporary industrialized architecture based on advanced information technology and highly technological production processes, implies a radically different approach to architecture than what we have experienced in the past. Works of architecture composed of prefabricated building components......, contain distinctive architectural traits, not only based on rational repetition, but also supporting composition and montage as dynamic concepts. Prefab architecture is an architecture of fragmentation, individualization and changeability, and this sets up new challenges for the architect. This paper...... tries to develop a strategy for the architect dealing with industrially based architecture; a strategy which exploits architectural potentials in industrial building, which recognizes the rules of mass production and which redefines the architect’s position among the agents of building. If recent...

  14. Structure of peptide fragments of a cross-linked complex of [Lys(Abz){sup 26}]neurotoxin II from Naja naja oxiana with the nicotinic acetylcholine receptor from Torpedo californica

    Energy Technology Data Exchange (ETDEWEB)

    Utkin, Yu.N.; Machold, J.; Franke, P. [M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Moscow (Russian Federation)] [and others

    1994-09-10

    After irradiation of a complex of the nicotinic acetylcholine receptor (AChR) with iodinated [Lys(Abz){sup 26}]neurotoxin II, the labeled {delta}-subunit of AChR was isolated, and it was cleaved with the aid of LysC endoproteinase, the hydrolysate being separated by rfHPLC. In a mass-spectrometric analysis of the radioactive fraction, the peptide of the {delta}-subunit (M{sub r} 2593) was detected. By purification of the radioactive rfHPLC fraction with the aid of electrophoresis in tricine gel, three radioactive bands were obtained (M {approximately} 16, 10, and 8 kDa). Edman degradation gave for all of them the sequence of a fragment of the {delta}-subunit beginning from Phe{sup 148}. On further cleavage of the radioactive fraction within the gel by the action of AspN proteinase, followed by rfHPLC, the radioactive peak was eluted under conditions close to those for the elution of the single radioactive peptide 30-44 obtained by the successive cleavage of the [{sup 125}I] neurotoxin II by LysC/AspN proteinases. This result shows the presence of the corresponding neurotoxin fragment in the sample in which the above-mentioned sequence of the receptor was detected. Since no sequences of the neurotoxin were detected in the radioactive products of the cross-linkages in model experiments at the picomolar level, neurotoxin II and its fragments were investigated by Edman degradation at the picomole level and so was the influence of the p-azidobenzyl group and its photoactivation on the degradation. On the whole, the sequencing of neurotoxin II and its fragments containing photolabeled and iodinated residues took place with extremely low initial yields; a further fall in the yields was observed on the degradation of irradiated Lys{sup 26}-peptides. The results obtained explain the difficulties in the detection of the sequences of the neurotoxin in cross-linkage products available in amounts of only 10-20 pmole.

  15. Optimal implantation depth and adherence to guidelines on permanent pacing to improve the results of transcatheter aortic valve replacement with the medtronic corevalve system: The CoreValve prospective, international, post-market ADVANCE-II study

    NARCIS (Netherlands)

    A.S. Petronio (Anna S.); J.-M. Sinning (Jan-Malte); N.M. van Mieghem (Nicolas); G. Zucchelli (Giulio); G. Nickenig (Georg); R. Bekeredjian (Raffi); J. Bosmans (Johan); F. Bedogni (Francesco); M. Branny (Marian); K. Stangl (Karl); J. Kovac (Jan); M. Schiltgen (Molly); S. Kraus (Stacia); P.P.T. de Jaegere (Peter)

    2015-01-01

    textabstractObjectives The aim of the CoreValve prospective, international, post-market ADVANCE-II study was to define the rates of conduction disturbances and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement with the Medtronic CoreValve System (Minneapolis,

  16. Analysis of energy released from core disruptive accident of sodium cooled fast reactor using CDA-ER and VENUS-II codes

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S. H.; Ha, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The fast reactor has a unique feature in that rearranged core materials can produce a large increase in reactivity and recriticality. If such a rearrangement of core materials should occur rapidly, there would be a high rate of reactivity increase producing power excursions. The released energy from such an energetic recriticality might challenge the reactor vessel integrity. An analysis of the hypothetical excursions that result in the disassembly of the reactor plays an important role in a liquid metal fast reactor (LMFR) safety analysis. The analysis of such excursions generally consists of three phases (initial or pre-disassembly phase, disassembly phase, energy-work conversion phase). The first step is referred to as the 'accident initiation' or 'pre-disassembly' phase. In this phase, the accident is traced from some initiating event, such as a coolant pump failure or control rod ejection, up to a prompt critical condition where high temperatures and pressures rapidly develop in the core. Such complex processes as fuel pin failure, sodium voiding, and fuel slumping are treated in this phase. Several computer programs are available for this type of calculation, including SAS4A, MELT-II and FREADM. A number of models have been developed for this type of analysis, including the REXCO and SOCOOL-II computer programs. VENUS-II deals with the second phase (disassembly analysis). Most of the models used in the code have been based on the original work of Bethe and Tait. The disassembly motion is calculated using a set of two-dimensional hydrodynamics equations in the VENUS code. The density changes can be explicitly calculated, which in turn allows the use of a more accurate density dependent equation of state. The main functional parts of the computational model can be summarized as follows: Power and energy (point kinetics), Temperature (energy balance), Internal pressure (equation of state), Material displacement (hydrodynamics), Reactivity

  17. A note on the self-similar solutions to the spontaneous fragmentation equation

    Science.gov (United States)

    Breschi, Giancarlo; Fontelos, Marco A.

    2017-05-01

    We provide a method to compute self-similar solutions for various fragmentation equations and use it to compute their asymptotic behaviours. Our procedure is applied to specific cases: (i) the case of mitosis, where fragmentation results into two identical fragments, (ii) fragmentation limited to the formation of sufficiently large fragments, and (iii) processes with fragmentation kernel presenting a power-like behaviour.

  18. Investigating the Theoretical Structure of the DAS-II Core Battery at School Age Using Bayesian Structural Equation Modeling

    Science.gov (United States)

    Dombrowski, Stefan C.; Golay, Philippe; McGill, Ryan J.; Canivez, Gary L.

    2018-01-01

    Bayesian structural equation modeling (BSEM) was used to investigate the latent structure of the Differential Ability Scales-Second Edition core battery using the standardization sample normative data for ages 7-17. Results revealed plausibility of a three-factor model, consistent with publisher theory, expressed as either a higher-order (HO) or a…

  19. A prescription and fast code for the long-term evolution of star clusters - II. Unbalanced and core evolution

    NARCIS (Netherlands)

    Gieles, M.; Alexander, P.E.R.; Lamers, H.J.G.L.M.; Baumgardt, H.

    2014-01-01

    We introduce version two of the fast star cluster evolution code Evolve Me A Cluster of StarS (emacss). The first version (Alexander and Gieles) assumed that cluster evolution is balanced for the majority of the life cycle, meaning that the rate of energy generation in the core of the cluster equals

  20. The formation of planets by disc fragmentation

    Directory of Open Access Journals (Sweden)

    Stamatellos Dimitris

    2013-04-01

    Full Text Available I discuss the role that disc fragmentation plays in the formation of gas giant and terrestrial planets, and how this relates to the formation of brown dwarfs and low-mass stars, and ultimately to the process of star formation. Protostellar discs may fragment, if they are massive enough and can cool fast enough, but most of the objects that form by fragmentation are brown dwarfs. It may be possible that planets also form, if the mass growth of a proto-fragment is stopped (e.g. if this fragment is ejected from the disc, or suppressed and even reversed (e.g by tidal stripping. I will discuss if it is possible to distinguish whether a planet has formed by disc fragmentation or core accretion, and mention of a few examples of observed exoplanets that are suggestive of formation by disc fragmentation.

  1. Multireversible redox processes in pentanuclear bis(triple-helical) manganese complexes featuring an oxo-centered triangular {Mn(II)2Mn(III)(μ3-O)}5+ or {Mn(II)Mn(III)2(μ3-O)}6+ core wrapped by two {Mn(II)2(bpp)3}-.

    Science.gov (United States)

    Romain, Sophie; Rich, Jordi; Sens, Cristina; Stoll, Thibaut; Benet-Buchholz, Jordi; Llobet, Antoni; Rodriguez, Montserrat; Romero, Isabel; Clérac, Rodolphe; Mathonière, Corine; Duboc, Carole; Deronzier, Alain; Collomb, Marie-Noëlle

    2011-09-05

    A new pentanuclear bis(triple-helical) manganese complex has been isolated and characterized by X-ray diffraction in two oxidation states: [{Mn(II)(μ-bpp)(3)}(2)Mn(II)(2)Mn(III)(μ-O)](3+) (1(3+)) and [{Mn(II)(μ-bpp)(3)}(2)Mn(II)Mn(III)(2)(μ-O)](4+) (1(4+)). The structure consists of a central {Mn(3)(μ(3)-O)} core of Mn(II)(2)Mn(III) (1(3+)) or Mn(II)Mn(III)(2) ions (1(4+)) which is connected to two apical Mn(II) ions through six bpp(-) ligands. Both cations have a triple-stranded helicate configuration, and a pair of enantiomers is present in each crystal. The redox properties of 1(3+) have been investigated in CH(3)CN. A series of five distinct and reversible one-electron waves is observed in the -1.0 and +1.50 V potential range, assigned to the Mn(II)(4)Mn(III)/Mn(II)(5), Mn(II)(3)Mn(III)(2)/Mn(II)(4)Mn(III), Mn(II)(2)Mn(III)(3)/Mn(II)(3)Mn(III)(2), Mn(II)Mn(III)(4)/Mn(II)(2)Mn(III)(3), and Mn(III)(5)/Mn(II)Mn(III)(4) redox couples. The two first oxidation processes leading to Mn(II)(3)Mn(III)(2) (1(4+)) and Mn(II)(2)Mn(III)(3) (1(5+)) are related to the oxidation of the Mn(II) ions of the central core and the two higher oxidation waves, close in potential, are thus assigned to the oxidation of the two apical Mn(II) ions. The 1(4+) and 1(5+) oxidized species and the reduced Mn(4)(II) (1(2+)) species are quantitatively generated by bulk electrolyses demonstrating the high stability of the pentanuclear structure in four oxidation states (1(2+) to 1(5+)). The spectroscopic characteristics (X-band electron paramagnetic resonance, EPR, and UV-visible) of these species are also described as well as the magnetic properties of 1(3+) and 1(4+) in solid state. The powder X- and Q-band EPR signature of 1(3+) corresponds to an S = 5/2 spin state characterized by a small zero-field splitting parameter (|D| = 0.071 cm(-1)) attributed to the two apical Mn(II) ions. At 40 K, the magnetic behavior is consistent for 1(3+) with two apical S = 5/2 {Mn(II)(bpp)(3)}(-) and one S

  2. Core-Shell Ferromagnetic Nanorod Based on Amine Polymer Composite (Fe3O4@DAPF) for Fast Removal of Pb(II) from Aqueous Solutions.

    Science.gov (United States)

    Venkateswarlu, Sada; Yoon, Minyoung

    2015-11-18

    Heavy metal ion removal from wastewater constitutes an important issue in the water treatment industry. Although a variety of nanomaterials have been developed for heavy metal removal via adsorption, the adsorption capacity, removal efficiency, and material recyclability still remain a challenge. Here, we present novel Fe3O4@DAPF core-shell ferromagnetic nanorods (CSFMNRs) for the removal of Pb(II) from aqueous solutions; they were prepared by the facile surface modification of twin-like ferromagnetic Fe3O4 nanorods using a 2,3-diaminophenol and formaldehyde (DAPF)-based polymer. The crystallinity and structure of the Fe3O4 nanorods were confirmed via X-ray diffraction (XRD). Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) revealed the core-shell morphology and composition of the materials. Pb(II) removal using the prepared Fe3O4@DAPF CSFMNRs was assessed, and comparable adsorption capacities (83.3 mg g(-1)) to the largest value were demonstrated. A thermodynamic study of the adsorption clearly indicated that the adsorption was exothermic and spontaneous. Due to the ferromagnetic properties with a high saturation magnetization value (56.1 emu g(-1)) of the nanorods, the nanorods exhibited excellent reusability with one of the fastest recovery times (25 s) among reported materials. Therefore, the Fe3O4@DAPF CSFMNRs can serve as recyclable adsorbent materials and as an alternative to commonly used sorbent materials for the rapid removal of heavy metals from aqueous solutions.

  3. Characterization and quantification of an in-core neutron irradiation facility at a TRIGA II research reactor

    Science.gov (United States)

    Aghara, Sukesh; Charlton, William

    2006-07-01

    Experiments have been performed to characterize the neutron environment at an in-core TRIGA type nuclear research reactor. Steady-state thermal and epithermal neutron environment testing is important for many applications including, materials, electronics and biological cells. A well characterized neutron environment at a research reactor, including energy spectrum and spatial distribution, can be useful to many research communities and for educational research. This paper describes the characterization process and an application of exposing electronics to high neutron fluence.

  4. Structural and magnetic characterization of three tetranuclear Cu(II) complexes with face-sharing-dicubane/double-open-cubane like core framework

    Science.gov (United States)

    Paul, Aparup; Bertolasi, Valerio; Figuerola, Albert; Manna, Subal Chandra

    2017-05-01

    Three novel tetranuclear copper(II) complexes namely [Cu4(L1)4]•2(dmf) (1), [Cu4(L1)4] (2) and [Cu4(L2)2(HL2)2(H2O)2]•2(ClO4)·6(H2O) (3) (H2L1, (E)-2-((1-hydroxybutan-2-ylimino)methyl)phenol; H2L2, (E)-2-((1-hydroxybutan-2-ylimino)methyl)-6-methoxyphenol)) were synthesized from the self-assembly of copper(II) perchlorate and the tridentate Schiff base ligands. The structural determination reveals that complex 1 crystallizes in the monoclinic system with space group C2/c, whereas both the complexes 2 and 3 crystallize in the triclinic system with space group P-1. Complexes 1 and 2 possess face-sharing dicubane core, on the other hand complex 3 has double open cubane core structure. The copper(II) ions in the cubane core are in distorted square planar geometries, and weak π…π and C-H…π interactions lead to formation of a 2D supramolecular architecture for complexes 1 and 2. At room temperature complexes 1, 2 and 3, exhibit fluorescence with a quantum yield (Φs) of 0.47, 0.49 and 0.38, respectively. Variable temperature magnetic susceptibility measurements in the range 2-300 K indicate an overall weak antiferromagnetic exchange coupling in all complexes. The PHI program was used to study their magnetic behaviour. In agreement with their face-sharing dicubane structure, a Hamiltonian of the type H =- J1(S1S2+S1S2'+S1'S2+S1'S2') - J2S1S1', where S1 = S1' = S2 = S2' = SCu =1/2, was used for studying complexes 1 and 2. Simulations performed suggest magnetic exchange constants with values close to J1 =-20 cm-1 and J2 =0 cm-1 for these complexes. On the other hand, the spin Hamiltonian H =- J1(S1S4+S2S3) - J2(S1S3+S2S4) - J3S1S2, where S1 = S2 = S3 = S4 = SCu =1/2, was used to study the magnetic behaviour of the double open cubane core of complex 3 and a good agreement between the experimental and simulated results was found by using the parameters g1 = g2 =2.20, g3 = g4 =2.18, J1 =-36 cm-1, J2 =-44 cm-1 and J3 =0 cm-1.

  5. A novel 1,3,5-triaminocyclohexane-based tripodal ligand forms a unique tetra(pyrazolate)-bridged tricopper(ii) core: solution equilibrium, structure and catecholase activity.

    Science.gov (United States)

    Szorcsik, Attila; Matyuska, Ferenc; Bényei, Attila; Nagy, Nóra V; Szilágyi, Róbert K; Gajda, Tamás

    2016-10-14

    Copper(ii) complexes of a polydentate tripodal ligand L × 3HCl (L = N,N',N''-tris(5-pyrazolylmethyl)-cis,cis-1,3,5-triaminocyclohexane) were characterized in both solution and solid states. Combined evaluation of potentiometric, UV-VIS, and EPR data indicated the formation of two mononuclear (CuHL, CuL) and three trinuclear (Cu3H-xL2, x = 2, 3, 4) complexes. The high stability and spectroscopic properties of the CuL species indicate a coordination of two pyrazole rings in addition to the three secondary amino groups of L in a square pyramidal geometry. In parallel with the formation of trinuclear species, intense charge transfer bands appear at around 400-500 nm, which indicate the formation of pyrazolate-bridged complexes. The crystal structure of [Cu3H-4L2](ClO4)2·5H2O (1) reveals the formation of a unique trinuclear complex that features a tetra(pyrazolate)-bridged linear tricopper(ii) core. The CuCu interatomic distances are around 3.8 Å. The two peripheral copper(ii) ions have a slightly distorted square pyramidal geometry. The four pyrazole rings bound to the peripheral copper(ii) ions are deprotonated and create a flattened tetrahedral environment for the central copper(ii), i.e. the formation of the trinuclear complexes is under the allosteric control of the two peripheral copper(ii) ions. The triply deprotonated trinuclear complex is an efficient catechol oxidase mimic with a surprisingly low pH optimum at pH = 5.6. Since the mononuclear CuL species is not able to promote the oxidation of 3,5-di-tert-butylcatechol, we assume that the central copper(ii) ion of the trinuclear complex with an unsaturated coordination sphere has a fundamental role in the binding and oxidation of the substrate. The experimental and structural details were further elaborated by a series of hybrid density functional theory calculations that support the presence of an antiferromagnetically coupled ground state. However, the magnitude and the pattern of spin coupling are

  6. Fragmentation and Hadronization

    OpenAIRE

    Webber, B.R.

    1999-01-01

    Experimental data, theoretical ideas and models concerning jet fragmentation and the hadronization process are reviewed, concentrating on the following topics: factorization and small-x resummation of fragmentation functions, hadronization models, single-particle yields and spectra in Z decay, comparisons between quark and gluon jets, current and target fragmentation in deep inelastic scattering, heavy quark fragmentation, Bose-Einstein correlations and WW fragmentation.

  7. Fragmentation and Hadronization

    OpenAIRE

    Webber, B.R.

    2000-01-01

    Experimental data, theoretical ideas and models concerning jet fragmentation and the hadronization process are reviewed, concentrating on the following topics: factorization and small-x resummation of fragmentation functions, hadronization models, single-particle yields and spectra in Z decay, comparisons between quark and gluon jets, current and target fragmentation in deep inelastic scattering, heavy quark fragmentation, Bose-Einstein correlations and WW fragmentation.

  8. The effect of suture caliber and number of core suture strands on zone II flexor tendon repair: a study in human cadavers.

    Science.gov (United States)

    Osei, Daniel A; Stepan, Jeffrey G; Calfee, Ryan P; Thomopoulos, Stavros; Boyer, Martin I; Potter, Ryan; Gelberman, Richard H

    2014-02-01

    To compare the tensile properties of a 3-0, 4-strand flexor tendon repair with a 4-0, 4-strand repair and a 4-0, 8-strand repair. Following evaluation of the intrinsic material properties of the 2 core suture calibers most commonly used in tendon repair (3-0 and 4-0), we tested the mechanical properties of 40 cadaver flexor digitorum profundus tendons after zone II repair with 1 of 3 techniques: a 3-0, 4-strand core repair, a 4-0, 8-strand repair, or a 4-0, 4-strand repair. We compared results across suture caliber for the 2 sutures and across tendon repair methods. Maximum load to failure of 3-0 polyfilament caprolactam suture was 49% greater than that of 4-0 polyfilament caprolactam suture. The cross-sectional area of 3-0 polyfilament caprolactam was 42% greater than that of 4-0 polyfilament caprolactam. The 4-0, 8-strand repair produced greater maximum load to failure when compared with the 2 4-strand techniques. Load at 2-mm gap, stiffness, and work to yield were significantly greater in the 4-0, 8-strand repair than in the 3-0, 4-strand repair. In an ex vivo model, an 8-strand repair using 4-0 suture was 43% stronger than a 4-strand repair using 3-0 suture, despite the finding that 3-0 polyfilament caprolactam was 49% stronger than 4-0 polyfilament caprolactam. These results suggest that, although larger-caliber suture has superior tensile properties, the number of core suture strands across a repair site has an important effect on time zero, ex vivo flexor tendon repair strength. Surgeons should consider using techniques that prioritize multistrand core suture repair over an increase in suture caliber. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  9. The Effect of Suture Caliber and Number of Core Suture Strands on Zone II Flexor Tendon Repair; A Study in Human Cadavers

    Science.gov (United States)

    Osei, Daniel A.; Stepan, Jeffrey G.; Calfee, Ryan P.; Thomopoulos, Stavros; Boyer, Martin I.; Potter, Ryan; Gelberman, Richard H.

    2014-01-01

    Purpose To compare the tensile properties of a 3-0, 4-strand flexor tendon repair to a 4-0, 4 strand repair and a 4-0, 8-strand repair. Methods Following evaluation of the intrinsic material properties of the 2 core suture calibers most commonly used in tendon repair (3-0 and 4-0), we tested the mechanical properties of 40 cadaver flexor digitorum profundus tendons after zone II repair with one of 3 techniques: a 3-0, 4-strand core repair, a 4-0, 8-strand repair, or a 4-0, 4-strand repair. We compared results across suture caliber for the 2 sutures and across tendon repair methods. Results Maximum load to failure of 3-0 polyfilament caprolactam suture was 49% greater than that of 4-0 polyfilament caprolactam suture. The cross sectional area of 3-0 Supramid was 42% greater than that of 4-0 Supramid. The 4-0, 8 strand, repair produced greater maximum load to failure when compared to the 2 4-strand techniques. Load at 2 mm gap, stiffness, and work to yield were significantly greater in the 4-0, 8-strand repair when compared to the 3-0, 4-strand repair. Discussion In an ex vivo model, an 8-strand repair using 4-0 suture was 43% stronger than a 4-strand repair using 3-0 suture, despite the finding that 3-0 polyfilament caprolactam was 49% stronger than was 4-0 polyfilament caprolactam. These results suggest that, although larger caliber suture has superior tensile properties, the number of core suture strands across a repair site has an important effect on time zero, ex vivo flexor tendon repair strength. Clinical Relevance Surgeons should consider using techniques that prioritize multi-strand core suture repair over an increase in suture caliber. PMID:24342261

  10. Modulating the M-M distance in dinuclear complexes. New ligand with a 2,2'-Biphenol fragment as key unit: synthesis, coordination behavior, and crystal structures of Cu(II) and Zn(II) dinuclear complexes.

    Science.gov (United States)

    Ambrosi, Gianluca; Formica, Mauro; Fusi, Vieri; Giorgi, Luca; Guerri, Annalisa; Micheloni, Mauro; Paoli, Paola; Pontellini, Roberto; Rossi, Patrizia

    2007-01-08

    The synthesis and characterization of the new polyamino-phenolic ligand 3,3'-bis[N,N-bis(2-aminoethyl)aminomethyl]-2,2'-dihydroxybiphenyl (L) are reported. L contains two diethylenetriamine units linked by a 1,1'-bis(2-phenol) group (BPH) on the central nitrogen atom which allows two separate binding amino subunits in a noncyclic ligand. The basicity and binding properties of L toward Cu(II) and Zn(II) were determined by means of potentiometric measurements in aqueous solution (298.1 +/- 0.1 K, I = 0.15 mol dm-3). L behaves as a pentaprotic base and as a monoprotic acid under the experimental conditions used, yielding the H5L5+ or H-1L- species, respectively. L forms both mono- and dinuclear species with both metal ions investigated; the dinuclear species are largely prevalent in aqueous solution with a L/M(II) molar ratio of 1:2 at pH higher than 7. L shows different behavior in Cu(II) and Zn(II) binding, affecting the dinuclear species formed and the distance between the two coordinated metal ions, which is greater in the Zn(II) than in the Cu(II) dinuclear species. This difference can be attributed to the different degree of protonation of BPH which influences the angle between the phenyl rings in the two systems. In this way, it is possible to modulate the M(II)-M(II) distance by the choice M(II) and to space the two M(II) farther away than was possible with the previously synthesized ligands. L does not saturate the coordination sphere of the coordinated M(II) ions in the dinuclear species, and thus, these latter species are prone to add guests. 1H and 13C NMR experiments carried out in aqueous solution, as well as the crystal structures of the dinuclear Cu(II) and Zn(II) species formed in aqueous solution, aided in elucidating the involvement of L and BPH in Zn(II) and Cu(II) stabilization.

  11. Implementation of multifilter based twin-prototypes for core electron temperature measurements in the TJ-II stellarator.

    Science.gov (United States)

    Baião, D; Medina, F; Ochando, M A; Varandas, C; Molinero, A; Chércoles, J

    2010-10-01

    The design and preliminary results from a prototype of a multifilter based electron temperature diagnostic for the TJ-II stellarator are presented. The diagnostic consists of four photodiodes with filters of different thicknesses to determine the electron temperature in a wide variety of plasma compositions, thanks to the set of six different signal-pairs ratios available. The impurity transport code IONEQ, the TJ-II soft x-ray tomography, and the VUV survey diagnostics give the necessary information to assess the proposed diagnostic reliability. In parallel, a vacuum-compatible multichannel electronic board has been designed for a future linear array to determine electron temperature profiles in high-density plasmas.

  12. Reforming the Regulation of Trading Venues in the EU under the Proposed MiFID II – Levelling the Playing Field and Overcoming Fragmentation?

    DEFF Research Database (Denmark)

    Clausen, Nis Jul; Sørensen, Karsten Engsig

    2012-01-01

    The Directive on Markets in Financial Instruments (MiFID 2004), adopted in 2004, brought about substantial changes in the market. Competition between trading venues has increased and a substantial portion of trade in financial instruments has moved from regulated markets to other trading venues....... This has created an unlevel playing field between regulated markets on the one hand and other trading venues on the other. At the same time, the fragmentation of trade has led to problems for ensuring investor protection and market surveillance. The Commission has recently proposed a reform of the Mi...... (MTFs), but that the proposals may introduce new problems of unequal competition in relation to new kinds of regulated trading venue (organised trading facilities – OTFs), and in relation to unregulated activities which are not considered to involve genuine trade execution. Most of the problems created...

  13. Fragmentation in massive star formation.

    Science.gov (United States)

    Beuther, Henrik; Schilke, Peter

    2004-02-20

    Studies of evolved massive stars indicate that they form in a clustered mode. During the earliest evolutionary stages, these regions are embedded within their natal cores. Here we present high-spatial-resolution interferometric dust continuum observations disentangling the cluster-like structure of a young massive star-forming region. The derived protocluster mass distribution is consistent with the stellar initial mass function. Thus, fragmentation of the initial massive cores may determine the initial mass function and the masses of the final stars. This implies that stars of all masses can form via accretion processes, and coalescence of intermediate-mass protostars appears not to be necessary.

  14. Core-shell designs of photoluminescent nanodiamonds with porous silica coatings for bioimaging and drug delivery II: application.

    Science.gov (United States)

    Prabhakar, Neeraj; Näreoja, Tuomas; von Haartman, Eva; Karaman, Didem Şen; Jiang, Hua; Koho, Sami; Dolenko, Tatiana A; Hänninen, Pekka E; Vlasov, Denis I; Ralchenko, Victor G; Hosomi, Satoru; Vlasov, Igor I; Sahlgren, Cecilia; Rosenholm, Jessica M

    2013-05-07

    Recent advances within materials science and its interdisciplinary applications in biomedicine have emphasized the potential of using a single multifunctional composite material for concurrent drug delivery and biomedical imaging. Here we present a novel composite material consisting of a photoluminescent nanodiamond (ND) core with a porous silica (SiO2) shell. This novel multifunctional probe serves as an alternative nanomaterial to address the existing problems with delivery and subsequent tracing of the particles. Whereas the unique optical properties of ND allows for long-term live cell imaging and tracking of cellular processes, mesoporous silica nanoparticles (MSNs) have proven to be efficient drug carriers. The advantages of both ND and MSNs were hereby integrated in the new composite material, ND@MSN. The optical properties provided by the ND core rendered the nanocomposite suitable for microscopy imaging in fluorescence and reflectance mode, as well as super-resolution microscopy as a STED label; whereas the porous silica coating provided efficient intracellular delivery capacity, especially in surface-functionalized form. This study serves as a demonstration how this novel nanomaterial can be exploited for both bioimaging and drug delivery for future theranostic applications.

  15. Composition and strain effects in Type I and Type II heterostructure ZnSe/Cd(Zn)S and ZnSe/Cd1-xZnxS core/shell quantum dots

    Science.gov (United States)

    Gheshlaghi, Negar; Pisheh, Hadi Sedaghat; Ünlü, Hilmi

    2017-11-01

    We investigated the effect of ternary shell alloy composition on the bandgap and diameter of core of ZnSe / Cd1 - x Znx S heterostructure core/shell quantum dots, which were synthesized by using a simple colloidal technique. Characterization by using the x-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis absorption and fluorescence emission spectroscopic techniques indicate that (i) there is a transition of ZnSe / Cd0.6 Zn0.4 S Type-I heterostructure (electrons and holes tend to localize in core) to ZnSe / Cd0.75 Zn0.25 S quasi-Type-II heterostructures (holes tend to localized in the core and electrons are delocalized) and (ii) then after large red shift and Stock-shift in PL emission spectra but not a distinct absorption peak in UV spectra become noticeable in ZnSe/Cd0.75Zn0.25 S quasi-Type II and ZnSe/CdS Type II heterostructures (electrons are localized in core and holes are localized in shell). Furthermore, the increase of Cd:S ratio in shell alloy composition shifts the XRD peaks to lower 2θ degrees which corresponds to tensile strain in the ZnSe core. Finally, the hydrostatic interfacial strain has effect on the squeezing or stretching the capped core: A decrease of compressive force on core from ZnSe/ZnS to tensile force in ZnSe/CdS with increase in Cd:S ratio indicates that transition of compressive strain to tensile strain takes place with the transition from Type-I to II heterostructure.

  16. Gas and dust in the star-forming region ρ Oph A. II. The gas in the PDR and in the dense cores

    Science.gov (United States)

    Larsson, B.; Liseau, R.

    2017-12-01

    Context. The evolution of interstellar clouds of gas and dust establishes the prerequisites for star formation. The pathway to the formation of stars can be studied in regions that have formed stars, but which at the same time also display the earliest phases of stellar evolution, i.e. pre-collapse/collapsing cores (Class -1), protostars (Class 0), and young stellar objects (Class I, II, III). Aims: We investigate to what degree local physical and chemical conditions are related to the evolutionary status of various objects in star-forming media. Methods: ρ Oph A displays the entire sequence of low-mass star formation in a small volume of space. Using spectrophotometric line maps of H2, H2O, NH3, N2H+, O2, O I, CO, and CS, we examine the distribution of the atomic and molecular gas in this dense molecular core. The physical parameters of these species are derived, as are their relative abundances in ρ Oph A. Using radiative transfer models, we examine the infall status of the cold dense cores from their resolved line profiles of the ground state lines of H2O and NH3, where for the latter no contamination from the VLA 1623 outflow is observed and line overlap of the hyperfine components is explicitly taken into account. Results: The stratified structure of this photon dominated region (PDR), seen edge-on, is clearly displayed. Polycyclic aromatic hydrocarbons (PAHs) and O I are seen throughout the region around the exciting star S 1. At the interface to the molecular core 0.05 pc away, atomic hydrogen is rapidly converted into H2, whereas O I protrudes further into the molecular core. This provides oxygen atoms for the gas-phase formation of O2 in the core SM 1, where X(O2) 5 × 10-8. There, the ratio of the O2 to H2O abundance [X(H2O) 5 × 10-9] is significantly higher than unity. Away from the core, O2 experiences a dramatic decrease due to increasing H2O formation. Outside the molecular core ρ Oph A, on the far side as seen from S 1, the intense radiation from

  17. Off-line combination of reversed-phase liquid chromatography and laser desorption/ionization time-of-flight mass spectrometry with seamless post-source decay fragment ion analysis for characterization of square-planar nickel(II) complexes.

    Science.gov (United States)

    Rehulka, Pavel; Popkov, Alexander; Nádvorník, Milan; Planeta, Josef; Mazanec, Karel; Chmelík, Josef

    2006-04-01

    Characterization of square-planar nickel(II) complexes of the Schiff base of (S)-N-benzylproline (2-benzoylphenyl)amide and various amino acids that are used as efficient alpha-amino acids synthons was carried out using laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) in off-line combination with liquid chromatography. A mixture of four square-planar nickel(II) complexes was separated using reversed-phase liquid chromatography (RPLC) and the separated fractions from the chromatographic run were spotted on the metal target directly from the column outlet using a lab-made sample deposition device. The separated fractions were then analyzed by LDI-TOF MS. Seamless postsource decay (sPSD) fragment ion analysis was used for their structural characterization, which made possible the confirmation of expected chemical structures of the analyzed compounds. The off-line combination of the separation by RPLC and analysis by LDI-TOF MS allowed successful separation, sensitive detection and structure elucidation of the square-planar nickel(II) complexes. Copyright (c) 2006 John Wiley & Sons, Ltd.

  18. Dust evolution, a global view: II. Top-down branching, nanoparticle fragmentation and the mystery of the diffuse interstellar band carriers.

    Science.gov (United States)

    Jones, A P

    2016-12-01

    The origin of the diffuse interstellar bands (DIBs), one of the longest-standing mysteries of the interstellar medium (ISM), is explored within the framework of The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS). The likely nature of the DIB carriers and their evolution is here explored within the framework of the structures and sub-structures inherent to doped hydrogenated amorphous carbon grains in the ISM. Based on the natural aromatic-rich moieties (asphaltenes) recovered from coal and oil, the likely structure of their interstellar analogues is investigated within the context of the diffuse band problem. It is here proposed that the top-down evolution of interstellar carbonaceous grains, and, in particular, a-C(:H) nanoparticles, is at the heart of the formation and evolution of the DIB carriers and their associations with small molecules and radicals, such as C2, C3, CH and CN. It is most probable that the DIBs are carried by dehydrogenated, ionized, hetero-cyclic, olefinic and aromatic-rich moieties that form an integral part of the contiguous structure of hetero-atom-doped hydrogenated amorphous carbon nanoparticles and their daughter fragmentation products. Within this framework, it is proposed that polyene structures in all their variants could be viable DIB carrier candidates.

  19. Piezophototronic Effect Enhanced Self-powered UV/Visible Photodetector Based on Type-II ZnO/ZnSe Core/Shell Heterojunction

    Science.gov (United States)

    Yan, Shuke; Rai, Satish; Zheng, Zhi; Alqarni, Fahad; Bhatt, Manish; Retana, Michael; Zhou, Weilie

    Piezophototronic effect, coupling of piezoelectric and optical properties in semiconductor materials, has attracted much interest recently because of its capabilities of improving device performance significantly. In this paper, we report a Piezophototronic effect enhanced self-powered broadband UV/visible photodetector based on ZnO/ZnSe core/shell nanowire array. The integrated photodetector based on the ZnO/ZnSe core/shell structure is capable of detecting the whole band range of the visible spectrum as well as UV light, and it is further boosted through applying compressive load under different wavelength excitation sources by three orders of magnitude in the relative responsivity. The significant improved performance is believed to stem from piezophototronic effect and its abrupt interface between ZnSe and ZnO. Furthermore, the device exhibits good self-powered photodetection performance under UV/visible light illumination. This work is expected to generate broad interest in exploring the application using type II heterostructure for broadband UV/visible photodetection under both powered and self-powered conditions.

  20. HLA Class I and Class II Conserved Extended Haplotypes and Their Fragments or Blocks in Mexicans: Implications for the Study of Genetic Diversity in Admixed Populations

    Science.gov (United States)

    Ohashi, Marina; Lebedeva, Tatiana; Acuña-Alonzo, Víctor; Yunis, María; Granados-Montiel, Julio; Cruz-Lagunas, Alfredo; Vargas-Alarcón, Gilberto; Rodríguez-Reyna, Tatiana S.; Fernandez-Viña, Marcelo; Granados, Julio; Yunis, Edmond J.

    2013-01-01

    Major histocompatibility complex (MHC) genes are highly polymorphic and informative in disease association, transplantation, and population genetics studies with particular importance in the understanding of human population diversity and evolution. The aim of this study was to describe the HLA diversity in Mexican admixed individuals. We studied the polymorphism of MHC class I (HLA-A, -B, -C), and class II (HLA-DRB1, -DQB1) genes using high-resolution sequence based typing (SBT) method and we structured the blocks and conserved extended haplotypes (CEHs) in 234 non-related admixed Mexican individuals (468 haplotypes) by a maximum likelihood method. We found that HLA blocks and CEHs are primarily from Amerindian and Caucasian origin, with smaller participation of African and recent Asian ancestry, demonstrating a great diversity of HLA blocks and CEHs in Mexicans from the central area of Mexico. We also analyzed the degree of admixture in this group using short tandem repeats (STRs) and HLA-B that correlated with the frequency of most probable ancestral HLA-C/−B and -DRB1/−DQB1 blocks and CEHs. Our results contribute to the analysis of the diversity and ancestral contribution of HLA class I and HLA class II alleles and haplotypes of Mexican admixed individuals from Mexico City. This work will help as a reference to improve future studies in Mexicans regarding allotransplantation, immune responses and disease associations. PMID:24086347

  1. Synthesis of Reabsorption-Suppressed Type-II/Type-I ZnSe/CdS/ZnS Core/Shell Quantum Dots and Their Application for Immunosorbent Assay

    Science.gov (United States)

    Wang, Sheng; Li, Jin Jie; Lv, Yanbing; Wu, Ruili; Xing, Ming; Shen, Huaibin; Wang, Hongzhe; Li, Lin Song; Chen, Xia

    2017-06-01

    We report a phosphine-free one-pot method to synthesize ZnSe/CdS/ZnS core-shell quantum dots (QDs) with composite type-II/type-I structures and consequent reabsorption suppression properties. The as-synthesized QDs possess high efficient red emission (with quantum yield of 82%) and high optical stability. Compared to type-I QDs, the ZnSe/CdS/ZnS QDs show larger Stokes shift and lower reabsorption which can reduce the emission loss and improve the level of fluorescence output. The ZnSe/CdS/ZnS QDs are used as fluorescent labels to exploit their application in fluorescence-linked immunosorbent assay (FLISA) for the first time in the detection of C-reactive protein (CRP) with a limit of detection (LOD) of 0.85 ng/mL, which is more sensitive than that of CdSe/ZnS type-I QDs based FLISA (1.00 ng/mL). The results indicate that the ZnSe/CdS/ZnS type-II/type-I QDs may be good candidates for applications in biomedical information detection.

  2. Semi-empirical calculations of radiative decay rates in Mo II. A comparison between oscillator strength parametrization and core-polarization-corrected relativistic Hartree-Fock approaches

    Science.gov (United States)

    Bouazza, Safa; Palmeri, Patrick; Quinet, Pascal

    2017-09-01

    We present a semi-empirical determination of Mo II radiative parameters in a wide wavelength range 1716-8789 Å. Our fitting procedure to experimental oscillator strengths available in the literature permits us to provide reliable values for a large number of Mo II lines, predicting previously unmeasured oscillator strengths of lines involving 4d45p and 4d35s5p odd-parity configurations. The extracted transition radial integral values are compared with ab-initio calculations: on average they are 0.88 times the values obtained with the basic pseudo-relativistic Hartree Fock method and they agree well when core polarization effects are included. When making a survey of our present and previous studies and including also those given in the literature we observe as general trends a decreasing of transition radial integral values with filling nd shells of the same principal quantum numbers for ndk(n + 1)s → ndk(n + 1)p transitions.

  3. Structural and magnetic characterization of three tetranuclear Cu(II) complexes with face-sharing-dicubane/double-open-cubane like core framework

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Aparup [Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721102, West Bengal (India); Bertolasi, Valerio [Dipartimento di Scienze Chimiche e Farmaceutiche, Centro di Strutturistica Diffrattometrica, Università di Ferrara, Via L. Borsari, 46, 44100 Ferrara (Italy); Figuerola, Albert [Departament de Química Inorgànica i Orgànica (Secció de Química Inorgànica) and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Manna, Subal Chandra, E-mail: scmanna@mail.vidyasagar.ac.in [Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721102, West Bengal (India)

    2017-05-15

    Three novel tetranuclear copper(II) complexes namely [Cu{sub 4}(L{sup 1}){sub 4}]∙2(dmf) (1), [Cu{sub 4}(L{sup 1}){sub 4}] (2) and [Cu{sub 4}(L{sup 2}){sub 2}(HL{sup 2}){sub 2}(H{sub 2}O){sub 2}]∙2(ClO{sub 4})·6(H{sub 2}O) (3) (H{sub 2}L{sup 1}, (E)−2-((1-hydroxybutan-2-ylimino)methyl)phenol; H{sub 2}L{sup 2}, (E)−2-((1-hydroxybutan-2-ylimino)methyl)−6-methoxyphenol)) were synthesized from the self-assembly of copper(II) perchlorate and the tridentate Schiff base ligands. The structural determination reveals that crystallizes in the monoclinic system with space group C2/c, whereas both the and crystallize in the triclinic system with space group P-1. and possess face-sharing dicubane core, on the other hand complex 3 has double open cubane core structure. The copper(II) ions in the cubane core are in distorted square planar geometries, and weak π…π and C–H…π interactions lead to formation of a 2D supramolecular architecture for and . At room temperature and , exhibit fluorescence with a quantum yield (Φ{sub s}) of 0.47, 0.49 and 0.38, respectively. Variable temperature magnetic susceptibility measurements in the range 2–300 K indicate an overall weak antiferromagnetic exchange coupling in all complexes. The PHI program was used to study their magnetic behaviour. In agreement with their face-sharing dicubane structure, a Hamiltonian of the type H =– J{sub 1}(S{sub 1}S{sub 2}+S{sub 1}S{sub 2’}+S{sub 1'}S{sub 2}+S{sub 1'}S{sub 2’}) – J{sub 2}S{sub 1}S{sub 1’}, where S{sub 1} = S{sub 1’} = S{sub 2} = S{sub 2’} = S{sub Cu} =1/2, was used for studying and . Simulations performed suggest magnetic exchange constants with values close to J{sub 1} =−20 cm{sup −1} and J{sub 2} =0 cm{sup -1} for these complexes. On the other hand, the spin Hamiltonian H =– J{sub 1}(S{sub 1}S{sub 4}+S{sub 2}S{sub 3}) – J{sub 2}(S{sub 1}S{sub 3}+S{sub 2}S{sub 4}) – J{sub 3}S{sub 1}S{sub 2}, where S{sub 1} = S{sub 2} = S{sub 3} = S{sub 4

  4. A Thiophene-Containing Conductive Metallopolymer Using an Fe(II) Bis(terpyridine) Core for Electrochromic Materials.

    Science.gov (United States)

    Liang, Yawei; Strohecker, Daniel; Lynch, Vincent; Holliday, Bradley J; Jones, Richard A

    2016-12-21

    Three Fe(II) bis(terpyridine)-based complexes with thiophene (Fe(L1)2), bithiophene (Fe(L2)2), and 3,4-ethylenedioxythiophene (Fe(L3)2) side chains were designed and synthesized for the purpose of providing two terminal active sites for electrochemical polymerization. The corresponding metallopolymers (poly-Fe(Ln)2, n = 2 or 3) were synthesized on indium tin oxide (ITO)-coated glass substrates via oxidative electropolymerization of the thiophene-substituted monomers and characterized using electrochemistry, X-ray photoelectron spectroscopy, UV-vis spectroscopy, and atomic force microscopy. The film poly-Fe(L2)2 was further studied for electrochromic (EC) color-switching properties and fabricated into a solid-state EC device. Poly-Fe(L2)2 films exhibit an intense MLCT absorption band at 596 nm (ε = 4.7 × 10(4) M(-1) cm(-1)) in the UV-vis spectra without any applied voltage. Upon application of low potentials (between 1.1 and 0.4 V vs Fc(+)/Fc), the obtained electropolymerized film exhibited great contrast with a change of transmittance percentage (ΔT%) of 40% and a high coloration efficiency of 3823 cm(2) C(-1) with a switching time of 1 s. The film demonstrates commonplace stability and reversibility with a 10% loss in peak current intensity after 200 cyclic voltammetry cycles and almost no loss in change of transmittance (ΔT%) after 900 potential switches between 1.1 and 0.4 V (vs Fc(+)/Fc) with a time interval of 0.75 s. The electropolymerization of Fe(L2)2 provides convenient and controllable film fabrication. Electrochromic behavior was also achieved in a solid-state device composed of a poly-Fe(L2)2 film and a polymer-supported electrolyte sandwiched between two ITO-coated glass electrodes.

  5. Temperature Dependence of Light-Induced Absorbance Changes Associated with Chlorophyll Photooxidation in Manganese-Depleted Core Complexes of Photosystem II.

    Science.gov (United States)

    Zabelin, A A; Shkuropatova, V A; Shkuropatov, A Ya; Shuvalov, V A

    2015-10-01

    Mid-infrared (4500-1150 cm(-1)) absorbance changes induced by continuous illumination of Mn-depleted core complexes of photosystem II (PSII) from spinach in the presence of exogenous electron acceptors (potassium ferricyanide and silicomolybdate) were studied by FTIR difference spectroscopy in the temperature range 100-265 K. The FTIR difference spectrum for photooxidation of the chlorophyll dimer P680 was determined from the set of signals associated with oxidation of secondary electron donors (β-carotene, chlorophyll) and reduction of the primary quinone QA. On the basis of analysis of the temperature dependence of the P680(+)/P680 FTIR spectrum, it was concluded that frequencies of 13(1)-keto-C=O stretching modes of neutral chlorophyll molecules PD1 and PD2, which constitute P680, are similar to each other, being located at ~1700 cm(-1). This together with considerable difference between the stretching mode frequencies of keto groups of PD1(+) and PD2(+) cations (1724 and 1709 cm(-1), respectively) is in agreement with a literature model (Okubo et al. (2007) Biochemistry, 46, 4390-4397) suggesting that the positive charge in the P680(+) dimer is mainly localized on one of the two chlorophyll molecules. A partial delocalization of the charge between the PD1 and PD2 molecules in P680(+) is supported by the presence of a characteristic electronic intervalence band at ~3000 cm(-1). It is shown that a bleaching band at 1680 cm(-1) in the P680(+)/P680 FTIR spectrum does not belong to P680. A possible origin of this band is discussed, taking into account the temperature dependence (100-265 K) of light-induced absorbance changes of PSII core complexes in the visible spectral region from 620 to 720 nm.

  6. Magnetic core-shell CuFe2O4@C3N4 hybrids for visible light photocatalysis of Orange II.

    Science.gov (United States)

    Yao, Yunjin; Lu, Fang; Zhu, Yanping; Wei, Fengyu; Liu, Xueting; Lian, Chao; Wang, Shaobin

    2015-10-30

    Novel CuFe2O4@C3N4 core-shell photocatalysts were fabricated through a self-assembly method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, transmission electron microscopy and Uv-vis diffuse reflection spectroscopy. The photocatalytic performances of the CuFe2O4@C3N4 catalysts were evaluated in photo Fenton-like discoloration of Orange II dye using H2O2 as an oxidant under visible-light irradiation (λ>420 nm). It was found the CuFe2O4@C3N4 hybrid (mass ratio of CuFe2O4/g-C3N4 at 2:1) exhibits a superior activity as compared with single component of CuFe2O4 or g-C3N4 and the mixture of g-C3N4 and CuFe2O4, due to the elevation of the separation efficiency of photoinduced electron-hole pairs, resulted from the heterojunction between the interfaces of g-C3N4 and CuFe2O4. The quenching tests of different scavengers displayed that O2(•-), OH and h(+) are responsible for the Orange II decolorization. In addition, the effects of initial concentration of the dye contaminant (0.014-0.140 mM), different anions (Cl(-), SO4(2-), NO3(-), CH3COO(-) and HCO3(-)) and temperature (15-65 °C) in photoreaction were also investigated. The CuFe2O4@C3N4 sample exhibited stable performance without obvious loss of catalytic activity after five successive runs, showing a promising application for the photo-oxidative degradation of environmental contaminants. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. On Disciplinary Fragmentation and Scientific Progress

    Science.gov (United States)

    Balietti, Stefano; Mäs, Michael; Helbing, Dirk

    2015-01-01

    Why are some scientific disciplines, such as sociology and psychology, more fragmented into conflicting schools of thought than other fields, such as physics and biology? Furthermore, why does high fragmentation tend to coincide with limited scientific progress? We analyzed a formal model where scientists seek to identify the correct answer to a research question. Each scientist is influenced by three forces: (i) signals received from the correct answer to the question; (ii) peer influence; and (iii) noise. We observed the emergence of different macroscopic patterns of collective exploration, and studied how the three forces affect the degree to which disciplines fall apart into divergent fragments, or so-called “schools of thought”. We conducted two simulation experiments where we tested (A) whether the three forces foster or hamper progress, and (B) whether disciplinary fragmentation causally affects scientific progress and vice versa. We found that fragmentation critically limits scientific progress. Strikingly, there is no effect in the opposite causal direction. What is more, our results shows that at the heart of the mechanisms driving scientific progress we find (i) social interactions, and (ii) peer disagreement. In fact, fragmentation is increased and progress limited if the simulated scientists are open to influence only by peers with very similar views, or when within-school diversity is lost. Finally, disciplines where the scientists received strong signals from the correct answer were less fragmented and experienced faster progress. We discuss model’s implications for the design of social institutions fostering interdisciplinarity and participation in science. PMID:25790025

  8. ACFIS: a web server for fragment-based drug discovery

    Science.gov (United States)

    Hao, Ge-Fei; Jiang, Wen; Ye, Yuan-Nong; Wu, Feng-Xu; Zhu, Xiao-Lei; Guo, Feng-Biao; Yang, Guang-Fu

    2016-01-01

    In order to foster innovation and improve the effectiveness of drug discovery, there is a considerable interest in exploring unknown ‘chemical space’ to identify new bioactive compounds with novel and diverse scaffolds. Hence, fragment-based drug discovery (FBDD) was developed rapidly due to its advanced expansive search for ‘chemical space’, which can lead to a higher hit rate and ligand efficiency (LE). However, computational screening of fragments is always hampered by the promiscuous binding model. In this study, we developed a new web server Auto Core Fragment in silico Screening (ACFIS). It includes three computational modules, PARA_GEN, CORE_GEN and CAND_GEN. ACFIS can generate core fragment structure from the active molecule using fragment deconstruction analysis and perform in silico screening by growing fragments to the junction of core fragment structure. An integrated energy calculation rapidly identifies which fragments fit the binding site of a protein. We constructed a simple interface to enable users to view top-ranking molecules in 2D and the binding mode in 3D for further experimental exploration. This makes the ACFIS a highly valuable tool for drug discovery. The ACFIS web server is free and open to all users at http://chemyang.ccnu.edu.cn/ccb/server/ACFIS/. PMID:27150808

  9. Proteomics Core

    Data.gov (United States)

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in a...

  10. Multireversible redox processes in pentanuclear bis(triple-helical) manganese complexes featuring an oxo-centered triangular {Mn II 2Mn III(μ 3-O)} 5+ or {Mn IIMn III 2(μ 3-O)} 6+ core wrapped by two {Mn II 2(bpp) 3} -

    OpenAIRE

    Romain, Sophie; Rich Masallera, Jordi; Sens Llorca, Cristina; Stoll, Thibaut; Benet?Buchholz, Jordi; Llobet Dalmases, Antoni; Rodríguez Pizarro, Montserrat; Romero García, Isabel; Clérac, Rodolphe; Mathonière, Corine; Duboc, Carole; Deronzier, Alain; Collomb, Marie-Noëlle

    2011-01-01

    A new pentanuclear bis(triple-helical) manganese complex has been isolated and characterized by X-ray diffraction in two oxidation states: [{Mn II(μ-bpp) 3} 2Mn II 2Mn III(μ-O)] 3+ (1 3+) and [{Mn II(μ-bpp) 3} 2Mn IIMn III 2(μ-O)] 4+ (1 4+). The structure consists of a central {Mn 3(μ 3-O)} core of Mn II 2Mn III (1 3+) or Mn IIMn III 2 ions (1 4+) which is connected to two apical Mn II ions through six bpp - ligands. Both cations have a triple-stranded helicate configuration, and a pair of en...

  11. A unified N-body and statistical treatment of stellar dynamics. I - The hybrid code. II - Applications to globular cluster cores

    Science.gov (United States)

    Mcmillan, S. L. W.; Lightman, A. P.

    1984-01-01

    A unified N-body and statistical treatment of stellar dynamics is developed and applied to the late stages of core collapse and early stages of post collapse evolution in globular clusters. A 'hybrid' computer code is joined to a direct N-body code which is used to calculate exactly the behavior of particles in the inner spatial region, and the combination is used to follow particles statistically in the outer spatial region. A transition zone allows the exchange of particles and energy between the two regions. The main application results include: formation of a hard central binary system, reversal of core collapse and expansion due to the heat input from this binary, ejection of the binary from the core, and recollapse of the core; density profiles that form a one-parameter sequence during the core oscillations; and indications that these oscillations will eventually cease.

  12. Fragmentation trees reloaded.

    Science.gov (United States)

    Böcker, Sebastian; Dührkop, Kai

    2016-01-01

    Untargeted metabolomics commonly uses liquid chromatography mass spectrometry to measure abundances of metabolites; subsequent tandem mass spectrometry is used to derive information about individual compounds. One of the bottlenecks in this experimental setup is the interpretation of fragmentation spectra to accurately and efficiently identify compounds. Fragmentation trees have become a powerful tool for the interpretation of tandem mass spectrometry data of small molecules. These trees are determined from the data using combinatorial optimization, and aim at explaining the experimental data via fragmentation cascades. Fragmentation tree computation does not require spectral or structural databases. To obtain biochemically meaningful trees, one needs an elaborate optimization function (scoring). We present a new scoring for computing fragmentation trees, transforming the combinatorial optimization into a Maximum A Posteriori estimator. We demonstrate the superiority of the new scoring for two tasks: both for the de novo identification of molecular formulas of unknown compounds, and for searching a database for structurally similar compounds, our method SIRIUS 3, performs significantly better than the previous version of our method, as well as other methods for this task. SIRIUS 3 can be a part of an untargeted metabolomics workflow, allowing researchers to investigate unknowns using automated computational methods.Graphical abstractWe present a new scoring for computing fragmentation trees from tandem mass spectrometry data based on Bayesian statistics. The best scoring fragmentation tree most likely explains the molecular formula of the measured parent ion.

  13. Fragmentation of monoclonal antibodies

    Science.gov (United States)

    Vlasak, Josef

    2011-01-01

    Fragmentation is a degradation pathway ubiquitously observed in proteins despite the remarkable stability of peptide bond; proteins differ only by how much and where cleavage occurs. The goal of this review is to summarize reports regarding the non-enzymatic fragmentation of the peptide backbone of monoclonal antibodies (mAbs). The sites in the polypeptide chain susceptible to fragmentation are determined by a multitude of factors. Insights are provided on the intimate chemical mechanisms that can make some bonds prone to cleavage due to the presence of specific side-chains. In addition to primary structure, the secondary, tertiary and quaternary structures have a significant impact in modulating the distribution of cleavage sites by altering local flexibility, accessibility to solvent or bringing in close proximity side chains that are remote in sequence. This review focuses on cleavage sites observed in the constant regions of mAbs, with special emphasis on hinge fragmentation. The mechanisms responsible for backbone cleavage are strongly dependent on pH and can be catalyzed by metals or radicals. The distribution of cleavage sites are different under acidic compared to basic conditions, with fragmentation rates exhibiting a minimum in the pH range 5–6; therefore, the overall fragmentation pattern observed for a mAb is a complex result of structural and solvent conditions. A critical review of the techniques used to monitor fragmentation is also presented; usually a compromise has to be made between a highly sensitive method with good fragment separation and the capability to identify the cleavage site. The effect of fragmentation on the function of a mAb must be evaluated on a case-by-case basis depending on whether cleavage sites are observed in the variable or constant regions, and on the mechanism of action of the molecule. PMID:21487244

  14. Improved Barriers to Turbine Engine Fragments: Final Annual Report

    National Research Council Canada - National Science Library

    Shockey, Donald

    2002-01-01

    This final annual technical report describes the progress rnade during year 4 of the SPI International Phase II effort to develop a computational capability for designing lightweight fragment barriers...

  15. Embedded Fragments Registry (EFR)

    Data.gov (United States)

    Department of Veterans Affairs — In 2009, the Department of Defense estimated that approximately 40,000 service members who served in OEF/OIF may have embedded fragment wounds as the result of small...

  16. Fragmentation Main Model

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The fragmentation model combines patch size and patch continuity with diversity of vegetation types per patch and rarity of vegetation types per patch. A patch was...

  17. DNA fragmentation in spermatozoa

    DEFF Research Database (Denmark)

    Rex, A S; Aagaard, J.; Fedder, J

    2017-01-01

    Sperm DNA Fragmentation has been extensively studied for more than a decade. In the 1940s the uniqueness of the spermatozoa protein complex which stabilizes the DNA was discovered. In the fifties and sixties, the association between unstable chromatin structure and subfertility was investigated....... In the seventies, the impact of induced DNA damage was investigated. In the 1980s the concept of sperm DNA fragmentation as related to infertility was introduced as well as the first DNA fragmentation test: the Sperm Chromatin Structure Assay (SCSA). The terminal deoxynucleotidyl transferase nick end labelling...... (TUNEL) test followed by others was introduced in the nineties. The association between DNA fragmentation in spermatozoa and pregnancy loss has been extensively investigated spurring the need for a therapeutic tool for these patients. This gave rise to an increased interest in the aetiology of DNA damage...

  18. Fragmented Work Stories

    DEFF Research Database (Denmark)

    Humle, Didde Maria; Reff Pedersen, Anne

    2015-01-01

    stories. We argue that meaning by story making is not always created by coherence and causality; meaning is created by different types of fragmentation: discontinuities, tensions and editing. The objective of this article is to develop and advance antenarrative practice analysis of work stories......Following a strand of narrative studies pointing to the living conditions of storytelling and the micro-level implications of working within fragmented narrative perspectives, this article contributes to narrative research on work stories by focusing on how meaning is created from fragmented...... by exploring how different types of fragmentation create meanings. This is done by studying the work stories of job and personnel consultants and by drawing on the results of a narrative, ethnographic study of a consultancy. The analysis demonstrates how work stories are social practices negotiated, retold...

  19. A DOUBLE CLUSTER AT THE CORE OF 30 DORADUS

    Energy Technology Data Exchange (ETDEWEB)

    Sabbi, E.; De Mink, S. E.; Walborn, N. R.; Anderson, J.; Bellini, A.; Panagia, N.; Van der Marel, R. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lennon, D. J. [ESA/STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gieles, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Apellaniz, J. Maiz, E-mail: sabbi@stsci.edu [Instituto de Astrofisica de Andalucia-CSIC, Glorieta de la Astronomia s/n, E-18008, Granada (Spain)

    2012-08-01

    Based on an analysis of data obtained with the Wide Field Camera 3 on the Hubble Space Telescope we report the identification of two distinct stellar populations in the core of the giant H II region 30 Doradus in the Large Magellanic Cloud. The most compact and richest component coincides with the center of R136 and is {approx}1 Myr younger than a second more diffuse clump, located {approx}5.4 pc toward the northeast. We note that published spectral types of massive stars in these two clumps lend support to the proposed age difference. The morphology and age difference between the two sub-clusters suggests that an ongoing merger may be occurring within the core of 30 Doradus. This finding is consistent with the predictions of models of hierarchical fragmentation of turbulent giant molecular clouds, according to which star clusters would be the final products of merging smaller sub-structures.

  20. Crystallographic fragment screening.

    Science.gov (United States)

    Badger, John

    2012-01-01

    Crystallographic fragment screening is a technique for initiating drug discovery in which protein crystals are soaked or grown with high concentrations of small molecule compounds (typically MW 110-250 Da) chosen to represent fragments of potential drugs. Specific binding of these compounds to the protein is subsequently visualized in electron density maps obtained from analysis of X-ray diffraction data collected from these crystals. Theoretical and practical experience indicate that a suitably diverse library of fragment compounds containing only a few hundred compounds may be sufficient to provide a comprehensive screen of the protein target. By soaking crystals in mixtures of 3-10 compounds a fragment screen may be completed within ∼100 diffraction data sets. This data collection requirement may be met given reproducible well-diffracting protein crystals and robotic sample handling equipment at a high flux X-ray source. The leading practical issue for most crystallography laboratories that wish to launch a fragment screening project is the design and/or procurement of an appropriate fragment library. Although several off-the-shelf fragment libraries are available from chemical suppliers, the numbers, sizes, and solubility of the compounds in relatively few of these libraries are well-match to the specific needs of the crystallographic screening experiment. Informed consideration of the properties of compounds in the screening library, possibly augmented by additional filtering of available compounds with appropriate search tools, is required to design a successful experiment. The analysis of results from crystallographic fragment screening involves highly repetitive application of routine image data processing and structure refinement calculations from many very similar crystals. Efficient handling of the data applies a high-throughput structure determination methodology that conveniently packages the structure solution calculations into a single process that

  1. Fragment Impact Toolkit (FIT)

    Energy Technology Data Exchange (ETDEWEB)

    Shevitz, Daniel Wolf [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Key, Brian P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garcia, Daniel B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-05

    The Fragment Impact Toolkit (FIT) is a software package used for probabilistic consequence evaluation of fragmenting sources. The typical use case for FIT is to simulate an exploding shell and evaluate the consequence on nearby objects. FIT is written in the programming language Python and is designed as a collection of interacting software modules. Each module has a function that interacts with the other modules to produce desired results.

  2. Identification of a functional, CRM-1-dependent nuclear export signal in hepatitis C virus core protein.

    Directory of Open Access Journals (Sweden)

    Andrea Cerutti

    Full Text Available Hepatitis C virus (HCV infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS, but no nuclear export signal (NES has yet been identified.We show here that the aa(109-133 region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126 in the identified NES or in the sequence encoding the mature core aa(1-173 significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication.Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection.

  3. Identification of a functional, CRM-1-dependent nuclear export signal in hepatitis C virus core protein.

    Science.gov (United States)

    Cerutti, Andrea; Maillard, Patrick; Minisini, Rosalba; Vidalain, Pierre-Olivier; Roohvand, Farzin; Pecheur, Eve-Isabelle; Pirisi, Mario; Budkowska, Agata

    2011-01-01

    Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS), but no nuclear export signal (NES) has yet been identified.We show here that the aa(109-133) region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126) in the identified NES or in the sequence encoding the mature core aa(1-173) significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication.Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection.

  4. Mass Spectral Fragmentation of VX

    National Research Council Canada - National Science Library

    Rohrbaugh, Dennis K

    2008-01-01

    The objective of this study was to provide structural identification of VX fragment ions formed during mass spectrometric analysis, elucidation of fragmentation pathways, and a compilation of tandem...

  5. Ice cores

    DEFF Research Database (Denmark)

    Svensson, Anders

    2014-01-01

    Ice cores from Antarctica, from Greenland, and from a number of smaller glaciers around the world yield a wealth of information on past climates and environments. Ice cores offer unique records on past temperatures, atmospheric composition (including greenhouse gases), volcanism, solar activity......, dustiness, and biomass burning, among others. In Antarctica, ice cores extend back more than 800,000 years before present (Jouzel et al. 2007), whereas. Greenland ice cores cover the last 130,000 years...

  6. Distortion of Magnetic Fields in a Starless Core II: 3D Magnetic Field Structure of FeSt 1-457

    Science.gov (United States)

    Kandori, Ryo; Tamura, Motohide; Tomisaka, Kohji; Nakajima, Yasushi; Kusakabe, Nobuhiko; Kwon, Jungmi; Nagayama, Takahiro; Nagata, Tetsuya; Tatematsu, Ken’ichi

    2017-10-01

    Three-dimensional (3D) magnetic field information on molecular clouds and cores is important for revealing their kinematical stability (magnetic support) against gravity, which is fundamental for studying the initial conditions of star formation. In the present study, the 3D magnetic field structure of the dense starless core FeSt 1-457 is determined based on the near-infrared polarimetric observations of the dichroic polarization of background stars and simple 3D modeling. With an obtained angle of line-of-sight magnetic inclination axis {θ }{inc} of 45^\\circ +/- 10^\\circ and previously determined plane-of-sky magnetic field strength {B}{pol} of 23.8 ± 12.1 μ {{G}}, the total magnetic field strength for FeSt 1-457 is derived to be 33.7 ± 18.0 μ {{G}}. The critical mass of FeSt 1-457, evaluated using both magnetic and thermal/turbulent support is {M}{cr}=3.70+/- 0.92 {M}ȯ , which is identical to the observed core mass, {M}{core}=3.55+/- 0.75 {M}ȯ . We thus conclude that the stability of FeSt 1-457 is in a condition close to the critical state. Without infalling gas motion and no associated young stars, the core is regarded to be in the earliest stage of star formation, i.e., the stage just before the onset of dynamical collapse following the attainment of a supercritical condition. These properties could make FeSt 1-457 one of the best starless cores for future studies of the initial conditions of star formation.

  7. Comparação entre fragmentos obtidos com agulhas de calibres 14 e 12 em "core biopsy" estereotáxica de lesões mamárias impalpáveis: diferenças entre o tamanho dos fragmentos e freqüência dos tipos de lesões diagnosticadas Comparison between the fragments obtained by stereotactic core biopsy of nonpalpable breast lesions using 14- and 12-gauge needles: differences on the length of the fragments obtained and on the frequency of the types of diagnosed lesions

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Abreu-e-Lima

    2001-10-01

    Full Text Available Com o objetivo de avaliar o desempenho das agulhas de calibres 14 e 12 na obtenção de "core biopsies" da mama sob controle estereotáxico, os autores compararam biópsias de lesões mamárias impalpáveis obtidas com agulhas desses calibres quanto ao tamanho dos fragmentos e freqüência dos tipos de lesões diagnosticadas. De um total de 1.009 biópsias, os autores analisaram 900 obtidas por agulhas 14 e 109 obtidas por agulhas 12, para análise da freqüência das lesões. Os tamanhos dos fragmentos foram analisados nos 700 primeiros casos para os espécimes obtidos por agulhas 14. A utilização de agulhas 12 resultou em maior tamanho dos fragmentos (p The purpose of this study was to compare the performance of 14- and 12-gauge needles for obtaining biopsy specimens under stereotactic guidance. The authors compared the biopsies of nonpalpable breast lesions using these different size needles, regarding the length of the fragments obtained and the types of diagnosed lesions. A total of 1,009 samples were obtained using 14-gauge (900 samples and 12-gauge (109 samples needles. The size of the samples was evaluated on the first 700 consecutive biopsies using 14-gauge needles. The use of 12-gauge needles consistently provided larger size specimens than 14-gauge needles (p < 0.001; a reduction in the prevalence of benign nonneoplastic lesions (p = 0.03 and a higher frequency of in situ and invasive carcinomas (p < 0.001 were also observed. These findings may suggest a higher diagnostic accuracy of biopsies performed with 12-gauge needles due to the larger samples obtained and/or due to a better radiological selection of those lesions, which were detected by digital mammography and biopsied under digital stereotactic guidance.

  8. A novel cryptic binding motif, LRSKSRSFQVSDEQY, in the C-terminal fragment of MMP-3/7-cleaved osteopontin as a novel ligand for α9β1 integrin is involved in the anti-type II collagen antibody-induced arthritis.

    Directory of Open Access Journals (Sweden)

    Shigeyuki Kon

    Full Text Available Osteopontin (OPN is a multifunctional protein that has been linked to various intractable inflammatory diseases. One way by which OPN induces inflammation is the production of various functional fragments by enzyme cleavage. It has been well appreciated that OPN is cleaved by thrombin, and/or matrix metalloproteinase-3 and -7 (MMP-3/7. Although the function of thrombin-cleaved OPN is well characterized, little is known about the function of MMP-3/7-cleaved OPN. In this study, we found a novel motif, LRSKSRSFQVSDEQY, in the C-terminal fragment of MMP-3/7-cleaved mouse OPN binds to α9β1 integrin. Importantly, this novel motif is involved in the development of anti-type II collagen antibody-induced arthritis (CAIA. This study provides the first in vitro and in vivo evidence that OPN cleavage by MMP-3/7 is an important regulatory mechanism for CAIA.

  9. Highly fluorescent platinum(II) organometallic complexes of perylene and perylene monoimide, with Pt σ-bonded directly to the perylene core.

    Science.gov (United States)

    Lentijo, Sergio; Miguel, Jesús A; Espinet, Pablo

    2010-10-18

    3-Bromoperylene (BrPer) or N-(2,5-di-tert-butylphenyl)-9-bromo-perylene-3,4-dicarboximide (BrPMI) react with [Pt(PEt(3))(4)] to yield trans-[PtR(PEt(3))(2)Br] (R = Per, 1a; R = PMI, 1b). Neutral and cationic perylenyl complexes containing a Pt(PEt(3))X group have been prepared from 1a,b by substitution of the Br ligand by a variety of other ligands (NCS, CN, NO(3), CN(t)Bu, PyMe). The X-ray structures of trans-[PtR(PEt(3))(2)X] (R = Per, X = NCS (2a); R = PMI, X = NO(3) (4b); R = Per, X = CN(t)Bu (5a)) show that the perylenyl fragment remains nearly planar and is arranged almost orthogonal to the coordination plane: The three molecules appear as individual entities in the solid state, with no π-π stacking of perylenyl rings. Each platinum complex exhibits fluorescence associated to the perylene or PMI fragments with emission quantum yields, in solution at room temperature, in the range 0.30-0.80 and emission lifetimes ∼4 ns, but with significantly different emission maxima, by influence of the X ligands on Pt. The similarity of the overall luminescence spectra of these metalated complexes with the perylene or PMI strongly suggests a perylene-dominated intraligand π-π*emissive state, metal-perturbed by interaction of the platinum fragment mostly via polarization of the Ar-Pt bond.

  10. Fragments of Time

    DEFF Research Database (Denmark)

    Christiansen, Steen Ledet

    Time travel films necessarily fragment linear narratives, as scenes are revisited with differences from the first time we saw it. Popular films such as Back to the Future mine comedy from these visitations, but there are many different approaches. One extreme is Chris Marker's La Jetée - a film...... made almost completely of still images, recounting the end of the world. These stills can be viewed as fragments that have survived the end of the world and now provide the only access to the events that occured. Shane Carruth's Primer has a different approach to time travel, the narrative diegesis...

  11. The Serendipity of Fragmentation

    DEFF Research Database (Denmark)

    Leixnering, Stephan; Meyer, Renate E.

    , it was the central government’s task to coordinate, steer and control the newly emerged decentralized organizations. This raises questions about the overall design of the public sector at present. Our paper engages with the prevalent public governance phenomenon of fragmentation from a design perspective in order...... form of organizing between networks and formal organization: lacking a single center and featuring multiplex and multifaceted relations within the politico-administrative apparatus and between government and PSOs, high fragmentation, local and robust action, but latent structures of significant formal...

  12. Computational tools for in silico fragment-based drug design.

    Science.gov (United States)

    Mortier, Jeremie; Rakers, Christin; Frederick, Raphael; Wolber, Gerhard

    2012-01-01

    Fragment-based strategy in drug design involves the initial discovery of low-molecular mass molecules. Owing to their small-size, fragments are molecular tools to probe specific sub-pockets within a protein active site. Once their interaction within the enzyme cavity is clearly understood and experimentally validated, they represent a unique opportunity to design potent and efficient larger compounds. Computer-aided methods can essentially support the identification of suitable fragments. In this review, available tools for computational drug design are discussed in the frame of fragmentbased approaches. We analyze and review (i) available commercial fragment libraries with respect to their properties and size, (ii) computational methods for the construction of such a library, (iii) the different strategies and software packages for the selection of the fragments with predicted affinity to a given target, and (iv) tools for the in silico linkage of fragments into an actual high-affinity lead structure candidate.

  13. Ternary-fragmentation-driving potential energies of 252Cf

    Science.gov (United States)

    Karthikraj, C.; Ren, Zhongzhou

    2017-12-01

    Within the framework of a simple macroscopic model, the ternary-fragmentation-driving potential energies of 252Cf are studied. In this work, all possible ternary-fragment combinations of 252Cf are generated by the use of atomic mass evaluation-2016 (AME2016) data and these combinations are minimized by using a two-dimensional minimization approach. This minimization process can be done in two ways: (i) with respect to proton numbers (Z1, Z2, Z3) and (ii) with respect to neutron numbers (N1, N2, N3) of the ternary fragments. In this paper, the driving potential energies for the ternary breakup of 252Cf are presented for both the spherical and deformed as well as the proton-minimized and neutron-minimized ternary fragments. From the proton-minimized spherical ternary fragments, we have obtained different possible ternary configurations with a minimum driving potential, in particular, the experimental expectation of Sn + Ni + Ca ternary fragmentation. However, the neutron-minimized ternary fragments exhibit a driving potential minimum in the true-ternary-fission (TTF) region as well. Further, the Q -value energy systematics of the neutron-minimized ternary fragments show larger values for the TTF fragments. From this, we have concluded that the TTF region fragments with the least driving potential and high Q values have a strong possibility in the ternary fragmentation of 252Cf. Further, the role of ground-state deformations (β2, β3, β4, and β6) in the ternary breakup of 252Cf is also studied. The deformed ternary fragmentation, which involves Z3=12 -19 fragments, possesses the driving potential minimum due to the larger oblate deformations. We also found that the ground-state deformations, particularly β2, strongly influence the driving potential energies and play a major role in determining the most probable fragment combinations in the ternary breakup of 252Cf.

  14. Stone fragmentation by ultrasound

    Indian Academy of Sciences (India)

    Some delicate nerves and fibres in the surrounding areas of the stones present in the kidney are also damaged by high ultrasonic intensity used in such systems. In the present work, enhancement of the kidney stone fragmentation by using ultrasound is studied. The cavitation bubbles are found to implode faster, with more ...

  15. Fragments of the Past

    Directory of Open Access Journals (Sweden)

    Peter Szende

    2016-10-01

    Full Text Available With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  16. Wildlife habitat fragmentation.

    Science.gov (United States)

    John. Lehmkuhl

    2005-01-01

    A primary issue in forest wildlife management is habitat fragmentation and its effects on viability, which is the "bottom line" for plant and animal species of conservation concern. Population viability is the likelihood that a population will be able to maintain itself (remain viable) over a long period of time-usually 100 years or more. Though it is true...

  17. Forming spectroscopic massive protobinaries by disc fragmentation

    Science.gov (United States)

    Meyer, D. M.-A.; Kuiper, R.; Kley, W.; Johnston, K. G.; Vorobyov, E.

    2018-01-01

    The surroundings of massive protostars constitute an accretion disc which has numerically been shown to be subject to fragmentation and responsible for luminous accretion-driven outbursts. Moreover, it is suspected to produce close binary companions which will later strongly influence the star's future evolution in the Hertzsprung-Russel diagram. We present three-dimensional gravitation-radiation-hydrodynamic numerical simulations of 100 M⊙ pre-stellar cores. We find that accretion discs of young massive stars violently fragment without preventing the (highly variable) accretion of gaseous clumps on to the protostars. While acquiring the characteristics of a nascent low-mass companion, some disc fragments migrate on to the central massive protostar with dynamical properties showing that its final Keplerian orbit is close enough to constitute a close massive protobinary system, having a young high- and a low-mass components. We conclude on the viability of the disc fragmentation channel for the formation of such short-period binaries, and that both processes - close massive binary formation and accretion bursts - may happen at the same time. FU-Orionis-type bursts, such as observed in the young high-mass star S255IR-NIRS3, may not only indicate ongoing disc fragmentation, but also be considered as a tracer for the formation of close massive binaries - progenitors of the subsequent massive spectroscopic binaries - once the high-mass component of the system will enter the main-sequence phase of its evolution. Finally, we investigate the Atacama Large (sub-)Millimeter Array observability of the disc fragments.

  18. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2008-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  19. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2010-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  20. Neo-Epitopes—Fragments of Cartilage and Connective Tissue Degradation in Early Rheumatoid Arthritis and Unclassified Arthritis

    DEFF Research Database (Denmark)

    Maijer, Karen I; Gudmann, Natasja Stæhr; Karsdal, Morten Asser

    2016-01-01

    Objective: Tissue destruction in rheumatoid arthritis (RA) is predominantly mediated by matrix metalloproteinases (MMPs), thereby generating protein fragments. Previous studies have revealed that these fragments include MMP-mediated collagen type I, II, and III degradation, citrullinated and MMP...

  1. Ligament Mediated Fragmentation of Viscoelastic Liquids

    Science.gov (United States)

    Keshavarz, Bavand; Houze, Eric C.; Moore, John R.; Koerner, Michael R.; McKinley, Gareth H.

    2016-10-01

    The breakup and atomization of complex fluids can be markedly different than the analogous processes in a simple Newtonian fluid. Atomization of paint, combustion of fuels containing antimisting agents, as well as physiological processes such as sneezing are common examples in which the atomized liquid contains synthetic or biological macromolecules that result in viscoelastic fluid characteristics. Here, we investigate the ligament-mediated fragmentation dynamics of viscoelastic fluids in three different canonical flows. The size distributions measured in each viscoelastic fragmentation process show a systematic broadening from the Newtonian solvent. In each case, the droplet sizes are well described by Gamma distributions which correspond to a fragmentation-coalescence scenario. We use a prototypical axial step strain experiment together with high-speed video imaging to show that this broadening results from the pronounced change in the corrugated shape of viscoelastic ligaments as they separate from the liquid core. These corrugations saturate in amplitude and the measured distributions for viscoelastic liquids in each process are given by a universal probability density function, corresponding to a Gamma distribution with nmin=4 . The breadth of this size distribution for viscoelastic filaments is shown to be constrained by a geometrical limit which can not be exceeded in ligament-mediated fragmentation phenomena.

  2. Ultraviolet photodetectors with high photosensitivity based on type-II ZnS/SnO2 core/shell heterostructured ribbons.

    Science.gov (United States)

    Huang, Xing; Yu, Yong-Qiang; Xia, Jing; Fan, Hua; Wang, Lei; Willinger, Marc-Georg; Yang, Xiao-Ping; Jiang, Yang; Zhang, Tie-Rui; Meng, Xiang-Min

    2015-03-12

    Semiconducting heterostructures with type-II band structure have attracted much attention due to their novel physical properties and wide applications in optoelectronics. Herein, we report, for the first time, a controlled synthesis of type-II ZnS/SnO2 heterostructured ribbon composed of SnO2 nanoparticles that uniformly cover the surface of ZnS ribbon via a simple and versatile thermal evaporation approach. Structural analysis indicated that the majority of SnO2 nanoparticles have an equivalent zone axis, i.e., of rutile SnO2, which is perpendicular to ±(2-1-10) facets (top/down surfaces) of ZnS ribbon. For those SnO2 nanoparticles decorated on ±(01-10) facets (side surfaces) of ZnS ribbon, an epitaxial relationship of (01-10)ZnO//(020)SnO2 and [2-1-10]ZnO//[001]SnO2 was identified. To explore their electronic and optoelectronic properties, we constructed field-effect transistors from as-prepared new heterostructures, which exhibited an n-type characteristic with an on/off ratio of ∼10(3) and a fast carrier mobility of ∼33.2 cm2 V(-1) s(-1). Owing to the spatial separation of photogenerated electron-hole pairs from type-II band alignment together with the good contacts between electrodes and ribbon, the resultant photodetector showed excellent photoresponse properties, including large photocurrent, high sensitivity (external quantum efficiency as high as ∼2.4×10(7)%), good stability and reproducibility, and relatively fast response speed. Our results suggest great potential of ZnS/SnO2 heterostructures for efficient UV light sensing, and, more importantly, signify the advantages of type-II semiconducting heterostructures for construction of high-performance nano-photodetectors.

  3. Cascading electron and hole transfer dynamics in a CdS/CdTe core-shell sensitized with bromo-pyrogallol red (Br-PGR): slow charge recombination in type II regime

    Science.gov (United States)

    Maity, Partha; Debnath, Tushar; Chopra, Uday; Ghosh, Hirendra Nath

    2015-01-01

    Ultrafast cascading hole and electron transfer dynamics have been demonstrated in a CdS/CdTe type II core-shell sensitized with Br-PGR using transient absorption spectroscopy and the charge recombination dynamics have been compared with those of CdS/Br-PGR composite materials. Steady state optical absorption studies suggest that Br-PGR forms strong charge transfer (CT) complexes with both the CdS QD and CdS/CdTe core-shell. Hole transfer from the photo-excited QD and QD core-shell to Br-PGR was confirmed by both steady state and time-resolved emission spectroscopy. Charge separation was also confirmed by detecting electrons in the conduction band of the QD and the cation radical of Br-PGR as measured from femtosecond transient absorption spectroscopy. Charge separation in the CdS/Br-PGR composite materials was found to take place in three different pathways, by transferring the photo-excited hole of CdS to Br-PGR, electron injection from the photo-excited Br-PGR to the CdS QD, and direct electron transfer from the HOMO of Br-PGR to the conduction band of the CdS QD. However, in the CdS/CdTe/Br-PGR system hole transfer from the photo-excited CdS to Br-PGR and electron injection from the photo-excited Br-PGR to CdS take place after cascading through the CdTe shell QD. Charge separation also takes place via direct electron transfer from the Br-PGR HOMO to the conduction band of CdS/CdTe. Charge recombination (CR) dynamics between the electron in the conduction band of the CdS QD and the Br-PGR cation radical were determined by monitoring the bleach recovery kinetics. The CR dynamics were found to be much slower in the CdS/CdTe/Br-PGR system than in the CdS/Br-PGR system. The formation of the strong CT complex and the separation of charges cascading through the CdTe shell help to slow down charge recombination in the type II regime.Ultrafast cascading hole and electron transfer dynamics have been demonstrated in a CdS/CdTe type II core-shell sensitized with Br

  4. Heavy-Quark Fragmentation

    CERN Document Server

    Cacciari, M; Cacciari, Matteo; Gardi, Einan

    2003-01-01

    We study perturbative and non-perturbative aspects of heavy-quark fragmentation into hadrons, emphasizing the large-x region, where x is the energy fraction of the detected hadron. We first prove that when the moment index N and the quark mass m get large simultaneously with the ratio (N Lambda/m) fixed, the fragmentation function depends on this ratio alone. This opens up the way to formulate the non-perturbative contribution to the fragmentation function at large N as a shape function of m(1-x) which is convoluted with the Sudakov-resummed perturbative result. We implement this resummation and the parametrization of the corresponding shape function using Dressed Gluon Exponentiation. The Sudakov exponent is calculated in a process independent way from a generalized splitting function which describes the emission probability of an off-shell gluon off a heavy quark. Non-perturbative corrections are parametrized based on the renormalon structure of the Sudakov exponent. They appear in moment space as an expone...

  5. Fracture, failure, and fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Dienes, J.K.

    1984-01-01

    Though continuum descriptions of material behavior are useful for many kinds of problems, particularly those involving plastic flow, a more general approach is required when the failure is likely to involve growth and coalescence of a large number of fractures, as in fragmentation. Failures of this kind appear frequently in rapid dynamic processes such as those resulting from impacts and explosions, particularly in the formation of spall fragments. In the first part of this paper an approach to formulating constitutive relations that accounts for the opening, shear and growth of an ensemble of cracks is discussed. The approach also accounts for plastic flow accompanying fragmentation. The resulting constitutive relations have been incorporated into a Lagrangean computer program. In the second part of this paper a theoretical approach to coalescence is described. The simplest formulation makes use of a linear Liouville equation, with crack growth limited by the mean free path of cracks, assumed constant. This approach allows for an anisotropic distribution of cracks. An alternative approach is also described in which the decrease of the mean free path with increasing crack size is accounted for, but the crack distribution is assumed isotropic. A reduction of the governing Liouville equation to an ordinary differential equation of third order is possible, and the result can be used to determine how mean-free-path decreases with increasing crack size.

  6. Ecosystem extent and fragmentation

    Science.gov (United States)

    Sayre, Roger; Hansen, Matt

    2017-01-01

    One of the candidate essential biodiversity variable (EBV) groups described in the seminal paper by Pereira et al. (2014) concerns Ecosystem Structure. This EBV group is distinguished from another EBV group which encompasses aspects of Ecosystem Function. While the Ecosystem Function EBV treats ecosystem processes like nutrient cycling, primary production, trophic interactions, etc., the Ecosystem Structure EBV relates to the set of biophysical properties of ecosystems that create biophysical environmental context, confer biophysical structure, and occur geographically. The Ecosystem Extent and Fragmentation EBV is one of the EBVs in the Ecosystem Structure EBV group.Ecosystems are understood to exist at multiple scales, from very large areas (macro-ecosystems) like the Arctic tundra, for example, to something as small as a tree in an Amazonian rain forest. As such, ecosystems occupy space and therefore can be mapped across any geography of interest, whether that area of interest be a site, a nation, a region, a continent, or the planet. One of the most obvious and seemingly straightforward EBVs is Ecosystem Extent and Fragmentation. Ecosystem extent refers to the location and geographic distribution of ecosystems across landscapes or in the oceans, while ecosystem fragmentation refers to the spatial pattern and connectivity of ecosystem occurrences on the landscape.

  7. The State-of-the-art HST Astro-photometric Analysis of the Core of ω Centauri. II. Differential-reddening Map

    Science.gov (United States)

    Bellini, A.; Anderson, J.; van der Marel, R. P.; King, I. R.; Piotto, G.; Bedin, L. R.

    2017-06-01

    We take advantage of the exquisite quality of the Hubble Space Telescope astro-photometric catalog of the core of ωCen presented in the first paper of this series to derive a high-resolution, high-precision, high-accuracy differential-reddening map of the field. The map has a spatial resolution of 2 × 2 arcsec2 over a total field of view of about 4.‧3 × 4.‧3. The differential reddening itself is estimated via an iterative procedure using five distinct color-magnitude diagrams, which provided consistent results to within the 0.1% level. Assuming an average reddening value E(B - V) = 0.12, the differential reddening within the cluster’s core can vary by up to ±10%, with a typical standard deviation of about 4%. Our differential-reddening map is made available to the astronomical community in the form of a multi-extension FITS file. This differential-reddening map is essential for a detailed understanding of the multiple stellar populations of ωCen, as presented in the next paper in this series. Moreover, it provides unique insight into the level of small spatial-scale extinction variations in the Galactic foreground. Based on archival observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  8. CONTROL OF FRAGMENTATION BY BLASTING

    OpenAIRE

    Božić, Branko

    1998-01-01

    The degree of fragmentation influences the economy of the excavation operations. Characteristics of blasted rock such as fragment size, volume and mass are fundamental variables effecting the economics of a mining operation and are in effect the basis for evaluating the quality of a blast. The properties of fragmentation, such as size and shape, are very important information for the optimization of production. Three factors control the fragment size distribution: the rock structure, the q...

  9. SCALING AND 4-QUARK FRAGMENTATION

    NARCIS (Netherlands)

    SCHOLTEN, O; BOSVELD, GD

    1991-01-01

    The conditions for a scaling behaviour from the fragmentation process leading to slow protons are discussed- The scaling referred to implies that the fragmentation functions depend on the light-cone momentum fraction only. It is shown that differences in the fragmentation functions for valence- and

  10. Core BPEL

    DEFF Research Database (Denmark)

    Hallwyl, Tim; Højsgaard, Espen

    extensions. Combined with the fact that the language definition does not provide a formal semantics, it is an arduous task to work formally with the language (e.g. to give an implementation). In this paper we identify a core subset of the language, called Core BPEL, which has fewer and simpler constructs......, does not allow omissions, and does not contain ignorable elements. We do so by identifying syntactic sugar, including default values, and ignorable elements in WS-BPEL. The analysis results in a translation from the full language to the core subset. Thus, we reduce the effort needed for working...... formally with WS-BPEL, as one, without loss of generality, need only consider the much simpler Core BPEL. This report may also be viewed as an addendum to the WS-BPEL standard specification, which clarifies the WS-BPEL syntax and presents the essential elements of the language in a more concise way...

  11. Ice Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice...

  12. Core benefits

    National Research Council Canada - National Science Library

    Keith, Brian W

    2010-01-01

    This SPEC Kit explores the core employment benefits of retirement, and life, health, and other insurance -benefits that are typically decided by the parent institution and often have significant governmental regulation...

  13. Fragmentation and clustering in star matter

    Directory of Open Access Journals (Sweden)

    Gulminelli F.

    2012-07-01

    Full Text Available The specificity of the crust-core phase transition in neutron star at zero and finite temperature will be discussed. It will be shown that, as a consequence of the presence of long range Coulomb interactions, the equivalence of statistical ensembles is violated and a clusterised phase is expected which is not accessible in the grancanonical ensemble. A specific analytical Nuclear Statistical Equilibrium model will be presented and some new quantitative results relevant for the supernova dynamics will be shown. Finally, the analogies and differences with the phenomenon of nuclear fragmentation will be highlighted.

  14. HIERARCHICAL FRAGMENTATION OF THE ORION MOLECULAR FILAMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Satoko; Ho, Paul T. P.; Su, Yu-Nung [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Teixeira, Paula S. [Institut fuer Astrophysik, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180, Wien (Austria); Zapata, Luis A., E-mail: satoko_t@asiaa.sinica.edu.tw [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia, Michoacan 58090 (Mexico)

    2013-01-20

    We present a high angular resolution map of the 850 {mu}m continuum emission of the Orion Molecular Cloud-3 (OMC 3) obtained with the Submillimeter Array (SMA); the map is a mosaic of 85 pointings covering an approximate area of 6.'5 Multiplication-Sign 2.'0 (0.88 Multiplication-Sign 0.27 pc). We detect 12 spatially resolved continuum sources, each with an H{sub 2} mass between 0.3-5.7 M {sub Sun} and a projected source size between 1400-8200 AU. All the detected sources are on the filamentary main ridge (n{sub H{sub 2}}{>=}10{sup 6} cm{sup -3}), and analysis based on the Jeans theorem suggests that they are most likely gravitationally unstable. Comparison of multi-wavelength data sets indicates that of the continuum sources, 6/12 (50%) are associated with molecular outflows, 8/12 (67%) are associated with infrared sources, and 3/12 (25%) are associated with ionized jets. The evolutionary status of these sources ranges from prestellar cores to protostar phase, confirming that OMC-3 is an active region with ongoing embedded star formation. We detect quasi-periodical separations between the OMC-3 sources of Almost-Equal-To 17''/0.035 pc. This spatial distribution is part of a large hierarchical structure that also includes fragmentation scales of giant molecular cloud ( Almost-Equal-To 35 pc), large-scale clumps ( Almost-Equal-To 1.3 pc), and small-scale clumps ( Almost-Equal-To 0.3 pc), suggesting that hierarchical fragmentation operates within the Orion A molecular cloud. The fragmentation spacings are roughly consistent with the thermal fragmentation length in large-scale clumps, while for small-scale cores it is smaller than the local fragmentation length. These smaller spacings observed with the SMA can be explained by either a helical magnetic field, cloud rotation, or/and global filament collapse. Finally, possible evidence for sequential fragmentation is suggested in the northern part of the OMC-3 filament.

  15. Hollow Core?

    Science.gov (United States)

    Qiao, G. J.; Liu, J. F.; Wang, Yang; Wu, X. J.; Han, J. L.

    We carried out the Gaussian fitting to the profile of PSR B1237+25 and found that six components rather than five are necessary to make a good fit. In the central part, we found that the core emission is not filled pencil beam but is a small hollow cone. This implies that the impact angle could be $\\beta<0.5^\\circ$. The ``hollow core'' is in agreement with Inverse Compton Scattering model of radio pulsars.

  16. Full MOX core in BWR

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, Motoo [Power and Industrial Systems R and D Laboratory, Hitachi Ltd., Hitachi, Ibaraki (Japan)

    1999-12-01

    Studies on the core design, the fuel rod thermal-mechanical design and the safety evaluation have been summarized for the Full MOX-ABWR, loaded with MOX fuels up to 100% of the core. Fuel bundle configuration for MOX fuels is identical to the STEP II fuel design and the discharge burnup is about 33 GWd/t. Core performance evaluations and fuel rod thermal-mechanical design analyses have been performed, and it has been confirmed that the design criteria are satisfied with enough margin like the UO{sub 2} fuel loaded core. Safety analyses on transients and accidents have also been performed by considering the MOX fuel and core characteristics adequately through selecting appropriate input data for each safety analysis. All safety criteria are satisfied like the UO{sub 2} core. (author)

  17. Land Use Change and Agricultural Land Fragmentation due to Anthropogenic Activities in an Hot Spot Area: A Case Study for Thrace Region of Turkey

    Science.gov (United States)

    Altürk, Bahadır; Konukcu, Fatih

    2017-04-01

    Agricultural lands that supply food, energy and ecosystem services for human life have been lost due to anthropogenic activities such as construction of roads, urban and industry areas. The significant reasons for the increase of artificial surfaces were poorly planned economic decisions by the government and internal migration due to this poorly planning. Unplanned urban sprawl also give rise to land fragmentation. Fragmentation of agricultural land affects both the agricultural production capacity and rural sustainable employment. In this study: i) Land use changes between 1990-2014 period were assessed using remotely sensed data and ii) Spatial and temporal agricultural land fragmentation were investigated using landscape pattern indice (effective mesh size), Morphological Spatial Pattern Analysis (MSPA) and Entropy method for 25 years period. The selected"hot spot" study area is located on east Thrace region of Turkey, being the service and industrial development zone where agricultural activities, water resources and natural habitat have been damaged due to rapid urban and industrial development for about 25 years. The results showed that agricultural lands decreased 6.44%, urban areas increased 111.68% and industry areas increased 251.19% during this 25 years period. Additionally, fragmentation analyses demonstrated that core agricultural areas sharply decreased and relative fragmentation (effective mesh size) increased from 50.68% to 56.77% during 1990 and 2014.

  18. Synthesis of arabinoxylan fragments

    DEFF Research Database (Denmark)

    Underlin, Emilie Nørmølle; Böhm, Maximilian F.; Madsen, Robert

    The cell wall of plants can be termed the skeleton of the plant. One of the parts making up the cell wall is hemicellulose. Hemicellulose is composed of a number of saccharides where one of the most abundant are the arabinoxylan-oligosaccharides. In many instances the biosynthesis and degration...... of arabinoxylan oligosaccharides remain elusive. As a consequence defined arabinoxylan fragments have been chosen as synthetic targets which subsequently will be submitted to enzymatic studies. A better understanding of these processes could lead to e.g. better utilisation of the biomass for biofuel production...

  19. An Archeology of Fragments

    Directory of Open Access Journals (Sweden)

    Gerald L. Bruns

    2014-10-01

    Full Text Available This is a short (fragmentary history of fragmentary writing from the German Romantics (F. W. Schlegel, Friedrich Hölderlin to modern and contemporary concrete or visual poetry. Such writing is (often deliberately a critique of the logic of subsumption that tries to assimilate whatever is singular and irreducible into totalities of various categorical or systematic sorts. Arguably, the fragment (parataxis is the distinctive feature of literary Modernism, which is a rejection, not of what precedes it, but of what Max Weber called “the rationalization of the world” (or Modernity whose aim is to keep everything, including all that is written, under surveillance and control.

  20. Preparation of graphene quantum dots based core-satellite hybrid spheres and their use as the ratiometric fluorescence probe for visual determination of mercury(II) ions

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Mengjuan [Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Wang, Chengquan [School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013 (China); Qian, Jing, E-mail: qianj@ujs.edu.cn [Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Wang, Kan; Yang, Zhenting; Liu, Qian; Mao, Hanping [Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Wang, Kun, E-mail: wangkun@ujs.edu.cn [Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China)

    2015-08-12

    We herein proposed a simple and effective strategy for preparing graphene quantum dots (GQDs)-based core-satellite hybrid spheres and further explored the feasibility of using such spheres as the ratiometric fluorescence probe for the visual determination of Hg{sup 2+}. The red-emitting CdTe QDs were firstly entrapped in the silica nanosphere to reduce their toxicity and improve their photo and chemical stabilities, thus providing a built-in correction for environmental effects, while the GQDs possessing good biocompatibility and low toxicity were electrostatic self-assembly on the silica surface acting as reaction sites. Upon exposure to the increasing contents of Hg{sup 2+}, the blue fluorescence of GQDs can be gradually quenched presumably due to facilitating nonradiative electron/hole recombination annihilation. With the embedded CdTe QDs as the internal standard, the variations of the tested solution display continuous fluorescence color changes from blue to red, which can be easily observed by the naked eye without any sophisticated instrumentations and specially equipped laboratories. This sensor exhibits high sensitivity and selectivity toward Hg{sup 2+} in a broad linear range of 10 nM–22 μM with a low detection limit of 3.3 nM (S/N = 3), much lower than the allowable Hg{sup 2+} contents in drinking water set by U.S. Environmental Protection Agency. This prototype ratiometric probe is of good simplicity, low toxicity, excellent stabilities, and thus potentially attractive for Hg{sup 2+} quantification related biological systems. - Highlights: • A facile strategy for preparing GQDs based core-satellite hybrid spheres was reported. • Such spheres can be used as the ratiometric fluorescence probe for Hg{sup 2+} detection. • The Hg{sup 2+} content can be easily distinguished by the naked eye. • The sensor shows high sensitivity and selectivity toward Hg{sup 2+} detection. • The ratiometric probe is of good simplicity, low toxicity, and

  1. Coordination chemistry of sugar-phosphate complexes with palladium(II), rhenium(V) and zinc(II)

    Energy Technology Data Exchange (ETDEWEB)

    Steinborn, Christian Martin

    2013-05-21

    As described before, some studies dealing with coordination chemistry of sugar phosphates are available but no analogous complexes of Zn{sup II} have been investigated yet. The primary goal of this work is, therefore, to fill this gap. In order to stay close to the active sites of enzymes such as class-II-aldolase, the simple metal fragment Zn{sup II}(dien) is used. NMR spectroscopy is used primarily as analytical method since it enables the investigation of both complex equilibria in solution and pH dependence of metal-binding sites. Since this approach is challenging due to the fast metal-ligand exchange and the absence of CIS values, it is necessary to improve the significance of NMR data collected from sugar-phosphate complexes with Zn{sup II}. Hence, further experiments are performed with molecules similar to sugar phosphates such as reducing and methylated sugars or polyols. Beside NMR spectroscopy, crystal-structure analysis will be used to get more detailed information about the binding pattern of the complexes. Additionally, sugar-phosphate complexes of Pd{sup II} are investigated. Further experiments are conducted, on the one hand, to synthesise more sugarphosphate complexes with ReVON2 fragments, and, on the other hand, to grow crystals confirming the theory about mixed sugar-core-phosphate chelation.

  2. Fragmentation of Chitosan by Acids

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Kasaai

    2013-01-01

    Full Text Available Fragmentation of chitosan in aqueous solution by hydrochloric acid was investigated. The kinetics of fragmentation, the number of chain scissions, and polydispersity of the fragments were followed by viscometry and size exclusion chromatography. The chemical structure and the degree of N-acetylation (DA of the original chitosan and its fragments were examined by 1H NMR spectroscopy and elemental analysis. The kinetic data indicates that the reaction was of first order. The results of polydispersity and the DA suggest that the selected experimental conditions (temperature and concentration of acid were appropriate to obtain the fragments having the polydispersity and the DA similar to or slightly different from those of the original one. A procedure to estimate molecular weight of fragments as well as the number of chain scissions of the fragments under the experimental conditions was also proposed.

  3. Three-dimensional Boltzmann-Hydro Code for Core-collapse in Massive Stars. II. The Implementation of Moving-mesh for Neutron Star Kicks

    Science.gov (United States)

    Nagakura, Hiroki; Iwakami, Wakana; Furusawa, Shun; Sumiyoshi, Kohsuke; Yamada, Shoichi; Matsufuru, Hideo; Imakura, Akira

    2017-04-01

    We present a newly developed moving-mesh technique for the multi-dimensional Boltzmann-Hydro code for the simulation of core-collapse supernovae (CCSNe). What makes this technique different from others is the fact that it treats not only hydrodynamics but also neutrino transfer in the language of the 3 + 1 formalism of general relativity (GR), making use of the shift vector to specify the time evolution of the coordinate system. This means that the transport part of our code is essentially general relativistic, although in this paper it is applied only to the moving curvilinear coordinates in the flat Minknowski spacetime, since the gravity part is still Newtonian. The numerical aspect of the implementation is also described in detail. Employing the axisymmetric two-dimensional version of the code, we conduct two test computations: oscillations and runaways of proto-neutron star (PNS). We show that our new method works fine, tracking the motions of PNS correctly. We believe that this is a major advancement toward the realistic simulation of CCSNe.

  4. TMI-2 core damage: a summary of present knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Owen, D.E.; Mason, R.E.; Meininger, R.D.; Franz, W.A.

    1983-01-01

    Extensive fuel damage (oxidation and fragmentation) has occurred and the top approx. 1.5 m of the center portion of the TMI-2 core has relocated. The fuel fragmentation extends outward to slightly beyond one-half the core radius in the direction examined by the CCTV camera. While the radial extent of core fragmentation in other directions was not directly observed, control and spider drop data and in-core instrument data suggest that the core void is roughly symmetrical, although there are a few indications of severe fuel damage extending to the core periphery. The core material fragmented into a broad range of particle sizes, extending down to a few microns. APSR movement data, the observation of damaged fuel assemblies hanging unsupported from the bottom of the reactor upper plenum structure, and the observation of once-molten stainless steel immediately above the active core indicate high temperatures (up to at least 1720 K) extended to the very top of the core. The relative lack of damage to the underside of the plenum structure implies a sharp temperature demarcation at the core/plenum interface. Filter debris and leadscrew deposit analyses indicate extensive high temperature core materials interaction, melting of the Ag-In-Cd control material, and transport of particulate control material to the plenum and out of the vessel.

  5. Hot prominence detected in the core of a coronal mass ejection. II. Analysis of the C III line detected by SOHO/UVCS

    Science.gov (United States)

    Jejčič, S.; Susino, R.; Heinzel, P.; Dzifčáková, E.; Bemporad, A.; Anzer, U.

    2017-11-01

    Context. We study the physics of erupting prominences in the core of coronal mass ejections (CMEs) and present a continuation of a previous analysis. Aims: We determine the kinetic temperature and microturbulent velocity of an erupting prominence embedded in the core of a CME that occurred on August 2, 2000 using the Ultraviolet Coronagraph and Spectrometer observations (UVCS) on board the Solar and Heliospheric Observatory (SOHO) simultaneously in the hydrogen Lα and C III lines. We develop the non-LTE (departures from the local thermodynamic equilibrium - LTE) spectral diagnostics based on Lα and Lβ measured integrated intensities to derive other physical quantities of the hot erupting prominence. Based on this, we synthesize the C III line intensity to compare it with observations. Methods: Our method is based on non-LTE modeling of eruptive prominences. We used a general non-LTE radiative-transfer code only for optically thin prominence points because optically thick points do not allow the direct determination of the kinetic temperature and microturbulence from the line profiles. The input parameters of the code were the kinetic temperature and microturbulent velocity derived from the Lα and C III line widths, as well as the integrated intensity of the Lα and Lβ lines. The code runs in three loops to compute the radial flow velocity, electron density, and effective thickness as the best fit to the Lα and Lβ integrated intensities within the accuracy defined by the absolute radiometric calibration of UVCS data. Results: We analyzed 39 observational points along the whole erupting prominence because for these points we found a solution for the kinetic temperature and microturbulent velocity. For these points we ran the non-LTE code to determine best-fit models. All models with τ0(Lα) ≤ 0.3 and τ0(C III) ≤ 0.3 were analyzed further, for which we computed the integrated intensity of the C III line using a two-level atom. The best agreement between

  6. Controlled redox conversion of new X-ray-Characterized Mono- and dinuclear heptacoordinated Mn(II) complexes into di-micro-oxo-dimanganese core complexes.

    Science.gov (United States)

    Hureau, Christelle; Blanchard, Sébastien; Nierlich, Martine; Blain, Guillaume; Rivière, Eric; Girerd, Jean-Jacques; Anxolabéhère-Mallart, Elodie; Blondin, Geneviève

    2004-07-12

    Two heptacoordinated Mn(II) complexes are isolated and X-ray characterized using the well-known tpen ligand (tpen = N,N,N',N'-tetrakis(2-pyridylmethyl)-1,2-ethanediamine): [(tpen)Mn(OH(2))](ClO(4))(2) (1(ClO(4))(2)) and [(tpen)Mn(micro-OAc)Mn(tpen)](ClO(4))(3).2H(2)O (2(ClO(4))(3).2H(2)O). Crystallographic data for 1(ClO(4))(2) at 110(2) K (respectively at 293(2) K): monoclinic, space group C2/c, a = 15.049(3) A (15.096(3) A), b = 9.932(2) A (10.105(2) A), c = 19.246(4) A (19.443(4) A), beta = 94.21(3) degrees (94.50(3) degrees ), Z = 4. Crystallographic data for 2(ClO(4))(3).0.5(C(2)H(5))(2)O at 123(2) K: triclinic, space group P, a = 12.707(3) A, b = 12.824(3) A, c = 19.052(4) A, alpha = 102.71(3) degrees, beta = 97.83(3) degrees, gamma = 98.15(3) degrees, Z = 2. Investigation of the variation upon temperature of the molar magnetic susceptibility of compound 2(ClO(4))(3).2H(2)O reveals a weak antiferromagnetic exchange interaction between the two high-spin Mn(II) ions (J = -0.65 +/- 0.05 cm(-)(1), H = -JS(1).S(2)). EPR spectra are recorded on powder samples and on frozen acetonitrile solutions, demonstrating the maintenance upon dissolution of the heptacoordination of Mn in complex 1 while complex 2 partially dissociates. Electrochemical responses of complexes 1 and 2 are investigated in acetonitrile, and bulk electrolyses are performed at oxidative potential in the presence of various amounts of 2,6-lutidine (0-2.65 equiv per Mn ion). The formation from either 1 or 2 of the mixed-valent complex [(tpen)Mn(III)(micro-O)(2)Mn(IV)(tpen)](3+) (3) is established from mass spectrometry and EPR and IR spectroscopy measurements. When reaction is started from 2, formation of [(tpen)Mn(IV)(micro-O)(2)(micro-OAc)Mn(IV)](3+) (4) is evidenced from cyclic voltammetry, EPR, and UV-vis data. The Mn vs tpen ratio in the electrogenerated complexes is accurately controlled by the quantity of additional 2,6-lutidine. The role of tpen as a base is discussed.

  7. Preparation of graphene quantum dots based core-satellite hybrid spheres and their use as the ratiometric fluorescence probe for visual determination of mercury(II) ions.

    Science.gov (United States)

    Hua, Mengjuan; Wang, Chengquan; Qian, Jing; Wang, Kan; Yang, Zhenting; Liu, Qian; Mao, Hanping; Wang, Kun

    2015-08-12

    We herein proposed a simple and effective strategy for preparing graphene quantum dots (GQDs)-based core-satellite hybrid spheres and further explored the feasibility of using such spheres as the ratiometric fluorescence probe for the visual determination of Hg(2+). The red-emitting CdTe QDs were firstly entrapped in the silica nanosphere to reduce their toxicity and improve their photo and chemical stabilities, thus providing a built-in correction for environmental effects, while the GQDs possessing good biocompatibility and low toxicity were electrostatic self-assembly on the silica surface acting as reaction sites. Upon exposure to the increasing contents of Hg(2+), the blue fluorescence of GQDs can be gradually quenched presumably due to facilitating nonradiative electron/hole recombination annihilation. With the embedded CdTe QDs as the internal standard, the variations of the tested solution display continuous fluorescence color changes from blue to red, which can be easily observed by the naked eye without any sophisticated instrumentations and specially equipped laboratories. This sensor exhibits high sensitivity and selectivity toward Hg(2+) in a broad linear range of 10 nM-22 μM with a low detection limit of 3.3 nM (S/N = 3), much lower than the allowable Hg(2+) contents in drinking water set by U.S. Environmental Protection Agency. This prototype ratiometric probe is of good simplicity, low toxicity, excellent stabilities, and thus potentially attractive for Hg(2+) quantification related biological systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. CONTROL OF FRAGMENTATION BY BLASTING

    Directory of Open Access Journals (Sweden)

    Branko Božić

    1998-12-01

    Full Text Available The degree of fragmentation influences the economy of the excavation operations. Characteristics of blasted rock such as fragment size, volume and mass are fundamental variables effecting the economics of a mining operation and are in effect the basis for evaluating the quality of a blast. The properties of fragmentation, such as size and shape, are very important information for the optimization of production. Three factors control the fragment size distribution: the rock structure, the quantity of explosive and its distribution within the rock mass. Over the last decade there have been considerable advances in our ability to measure and analyze blasting performance. These can now be combined with the continuing growth in computing power to develop a more effective description of rock fragmentation for use by future blasting practitioners. The paper describes a view of the fragmentation problem by blasting and the need for a new generation of engineering tools to guide the design and implementation of blasting operations.

  9. An Algebra for Program Fragments

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    1985-01-01

    Program fragments are described either by strings in the concrete syntax or by constructor applications in the abstract syntax. By defining conversions between these forms, both may be intermixed. Program fragments are constructed by terminal and nonterminal symbols from the grammar and by variab......Program fragments are described either by strings in the concrete syntax or by constructor applications in the abstract syntax. By defining conversions between these forms, both may be intermixed. Program fragments are constructed by terminal and nonterminal symbols from the grammar...

  10. Substrate and Lewis Acid Coordination Promote O-O Bond Cleavage of an Unreactive L2Cu(II)2(O2(2-)) Species to Form L2Cu(III)2(O)2 Cores with Enhanced Oxidative Reactivity.

    Science.gov (United States)

    Garcia-Bosch, Isaac; Cowley, Ryan E; Díaz, Daniel E; Peterson, Ryan L; Solomon, Edward I; Karlin, Kenneth D

    2017-03-01

    Copper-dependent metalloenzymes are widespread throughout metabolic pathways, coupling the reduction of O2 with the oxidation of organic substrates. Small-molecule synthetic analogs are useful platforms to generate L/Cu/O2 species that reproduce the structural, spectroscopic, and reactive properties of some copper-/O2-dependent enzymes. Landmark studies have shown that the conversion between dicopper(II)-peroxo species (L2Cu(II)2(O2(2-)) either side-on peroxo, (S)P, or end-on trans-peroxo, (T)P) and dicopper(III)-bis(μ-oxo) (L2Cu(III)2(O(2-))2: O) can be controlled through ligand design, reaction conditions (temperature, solvent, and counteranion), or substrate coordination. We recently published ( J. Am. Chem. Soc. 2012 , 134 , 8513 , DOI: 10.1021/ja300674m ) the crystal structure of an unusual (S)P species [(MeAN)2Cu(II)2(O2(2-))](2+) ((S)P(MeAN), MeAN: N-methyl-N,N-bis[3-(dimethylamino)propyl]amine) that featured an elongated O-O bond but did not lead to O-O cleavage or reactivity toward external substrates. Herein, we report that (S)P(MeAN) can be activated to generate O(MeAN) and perform the oxidation of external substrates by two complementary strategies: (i) coordination of substituted sodium phenolates to form the substrate-bound O(MeAN)-RPhO(-) species that leads to ortho-hydroxylation in a tyrosinase-like fashion and (ii) addition of stoichiometric amounts (1 or 2 equiv) of Lewis acids (LA's) to form an unprecedented series of O-type species (O(MeAN)-LA) able to oxidize C-H and O-H bonds. Spectroscopic, computational, and mechanistic studies emphasize the unique plasticity of the (S)P(MeAN) core, which combines the assembly of exogenous reagents in the primary (phenolates) and secondary (Lewis acids association to the MeAN ligand) coordination spheres with O-O cleavage. These findings are reminiscent of the strategy followed by several metalloproteins and highlight the possible implication of O-type species in copper-/dioxygen-dependent enzymes such as

  11. Thermodynamical string fragmentation

    Science.gov (United States)

    Fischer, Nadine; Sjöstrand, Torbjörn

    2017-01-01

    The observation of heavy-ion-like behaviour in pp collisions at the LHC suggests that more physics mechanisms are at play than traditionally assumed. The introduction e.g. of quark-gluon plasma or colour rope formation can describe several of the observations, but as of yet there is no established paradigm. In this article we study a few possible modifications to the Pythia event generator, which describes a wealth of data but fails for a number of recent observations. Firstly, we present a new model for generating the transverse momentum of hadrons during the string fragmentation process, inspired by thermodynamics, where heavier hadrons naturally are suppressed in rate but obtain a higher average transverse momentum. Secondly, close-packing of strings is taken into account by making the temperature or string tension environment-dependent. Thirdly, a simple model for hadron rescattering is added. The effect of these modifications is studied, individually and taken together, and compared with data mainly from the LHC. While some improvements can be noted, it turns out to be nontrivial to obtain effects as big as required, and further work is called for.

  12. Fragmentation of exotic oxygen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Leistenschneider, A.; Elze, Th.W.; Gruenschloss, A.; Palit, R. [Johann Wolfgang Goethe-Univ., Frankfurt (Germany). Inst. fuer Kernphysik; Aumann, T.; Cortina, D.; Datta Pramanik, U.; Emling, H.; Geissel, H.; Helariutta, K.; Hellstroem, M.; Ilievski, S.; Jones, K.; Muenzenberg, G.; Scheidenberger, C.; Schmidt, K.-H.; Suemmerer, K. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Boretzky, K.; Kratz, J.V.; Le Hong, Khiem [Johannes Gutenberg-Univ., Mainz (Germany). Inst. fue Kernchemie; Canto, L.F. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Fisica; Carlson, B.V. [Centro Tecnico Aeroespacial (CTA), Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica (ITA). Dept. de Fisica; Hussein, M.S. [Sao Paulo Univ. (USP), SP (Brazil). Inst. de Fisica; Kulessa, R.; Lubkiewicz, E.; Wajda, E.; Walus, W. [Uniwersytet Jagellonski, Krakow (Poland). Instytut Fizyki; Reiter, P. [Ludwig-Maximilians-Univ., Garching (Germany). Sektion Physik; Simon, H. [Technische Univ., Darmstadt (Germany). Inst. fuer Kernphysik

    2003-06-01

    Abrasion-ablation models and the empirical EPAX parametrization of projectile fragmentation are described. Their cross section predictions are compared to recent data of the fragmentation of secondary beams of neutron-rich, unstable {sup 19,20,21} O isotopes at beam energies near 600 MeV/nucleon as well as data for stable {sup 17,18} O beams. (author)

  13. Polymer fragmentation in extensional flow

    Energy Technology Data Exchange (ETDEWEB)

    Maroja, Armando M.; Oliveira, Fernando A.; Ciesla, Michal; Longa, Lech

    2001-06-01

    In this paper we present an analysis of fragmentation of dilute polymer solutions in extensional flow. The transition rate is investigated both from theoretical and computational approaches, where the existence of a Gaussian distribution for the breaking bonds has been controversial. We give as well an explanation for the low fragmentation frequency found in DNA experiments.

  14. Mass spectrometry for fragment screening.

    Science.gov (United States)

    Chan, Daniel Shiu-Hin; Whitehouse, Andrew J; Coyne, Anthony G; Abell, Chris

    2017-11-08

    Fragment-based approaches in chemical biology and drug discovery have been widely adopted worldwide in both academia and industry. Fragment hits tend to interact weakly with their targets, necessitating the use of sensitive biophysical techniques to detect their binding. Common fragment screening techniques include differential scanning fluorimetry (DSF) and ligand-observed NMR. Validation and characterization of hits is usually performed using a combination of protein-observed NMR, isothermal titration calorimetry (ITC) and X-ray crystallography. In this context, MS is a relatively underutilized technique in fragment screening for drug discovery. MS-based techniques have the advantage of high sensitivity, low sample consumption and being label-free. This review highlights recent examples of the emerging use of MS-based techniques in fragment screening. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  15. The Impact of Dark and Visible Fragmentation on Market Quality

    NARCIS (Netherlands)

    Degryse, H.A.; de Jong, F.C.J.M.; van Kervel, V.L.

    2011-01-01

    Two important characteristics of current European equity markets are rooted in changes in financial regulation (the Markets in Financial Instruments Directive). The regulation (i) allows new trading venues to emerge, generating a fragmented market place and (ii) allows for a substantial fraction of

  16. Population structure of Salmonella investigated by amplified fragment length polymorphism

    DEFF Research Database (Denmark)

    Torpdahl, M.; Ahrens, Peter

    2004-01-01

    Aims: This study was undertaken to investigate the usefulness of amplified fragment length polymorphism (AFLP) in determining the population structure of Salmonella. Methods and Results: A total of 89 strains were subjected to AFLP analysis using the enzymes BglII and BspDI, a combination...

  17. Highly efficient simultaneous ultrasonic assisted adsorption of Pb (II) by Fe3O4@MnO2 core-shell magnetic nanoparticles: Synthesis and characterization, kinetic, equilibrium, and thermodynamic studies

    Science.gov (United States)

    Ashrafi, Amir; Rahbar-Kelishami, Ahmad; Shayesteh, Hadi

    2017-11-01

    Fe3O4@MnO2 core-shell nanoparticles were prepared by a simple one-pot method and characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM) and BET surface area measurement. These nanoparticles were applied for removal of lead ions from aqueous solution by a batch technique. The influence of different adsorption parameters, such as contact time, the dosage of adsorbent, initial concentration of lead ions, pH value of solution and temperature have been investigated. The equilibrium data for adsorption of Pb (II) were fitted well by Langmuir isotherm and the maximum adsorption capacity was 666.67 mg/g at 298 K approximately. The kinetic data were described better with pseudo-second-order kinetic model. In addition, thermodynamic calculations revealed that the adsorption process was spontaneous, exothermic and feasible. Due to easy synthesis of Fe3O4@MnO2 nanoparticles, its fast adsorption, magnetic properties and high adsorption capacity, it can be employed for efficient removal of lead ions.

  18. The spectroscopy of fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.R. [Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    High-resolution measurements on {gamma} rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author) 24 refs., 8 figs., 1 tab.

  19. Stratigraphy and depositional history of the Apollo 17 drill core

    Science.gov (United States)

    Taylor, G. J.; Warner, R. D.; Keil, K.

    1979-01-01

    Lithologic abundances obtained from modal analyses of a continuous string of polished thin sections indicate that the Apollo 17 deep drill core can be divided into three main zones: An upper zone (0-19 cm depth) characterized by high abundances of agglutinates (30%) and a high ratio of mare to non-mare lithic fragments (less than 0.8); a coarse-grained layer (24-56 cm) rich in fragments of high-Ti mare basalts and mineral fragments derived from them, and poor in agglutinates (6%); and a lower zone (56-285 cm) characterized by variable but generally high agglutinate abundances (25%) and a low ratio of mare to nonmare lithic fragments (0.6). Using observations of the geology of the landing site, the principles of cratering dynamics, and the vast amount of data collected on the core, the following depositional history for the section of regolith sampled by the Apollo 17 drill core: was devised.

  20. AUTOMATED DETECTION OF STRUCTURAL ALERTS (CHEMICAL FRAGMENTS IN (ECOTOXICOLOGY

    Directory of Open Access Journals (Sweden)

    Alban Lepailleur

    2013-02-01

    Full Text Available This mini-review describes the evolution of different algorithms dedicated to the automated discovery of chemical fragments associated to (ecotoxicological endpoints. These structural alerts correspond to one of the most interesting approach of in silico toxicology due to their direct link with specific toxicological mechanisms. A number of expert systems are already available but, since the first work in this field which considered a binomial distribution of chemical fragments between two datasets, new data miners were developed and applied with success in chemoinformatics. The frequency of a chemical fragment in a dataset is often at the core of the process for the definition of its toxicological relevance. However, recent progresses in data mining provide new insights into the automated discovery of new rules. Particularly, this review highlights the notion of Emerging Patterns that can capture contrasts between classes of data.

  1. Light quark fragmentations into pions

    Science.gov (United States)

    Edemskaya, A. K.; Naumov, D. V.; Samoylov, O. B.

    2011-12-01

    We discuss a process of hadronization of light quarks into charged pions in e + e - annihilations and in deep inelastic scatering of charged leptons and neutrino off nucleons. The corresponding semi-inclusive cross-sections of pions production we write in terms of quark fragmentation functions and fracture functions. We suggest a new method of measurements of fragmentation and fracture functions based on analysis of semiinclusive data.

  2. QGP and Modified Jet Fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-Nian

    2005-04-18

    Recent progresses in the study of jet modification in hotmedium and their consequences in high-energy heavy-ion collisions are reviewed. In particular, I will discuss energy loss for propagating heavy quarks and the resulting modified fragmentation function. Medium modification of the parton fragmentation function due to quark recombination are formulated within finite temperature field theory and their implication on the search for deconfined quark-gluon plasma is also discussed.

  3. Melt jet fragmentation and oxidation in the lower plenum

    Energy Technology Data Exchange (ETDEWEB)

    Berthoud, G. [CEA-DEN-DTP, Grenoble (France)

    2001-07-01

    During the late phases of a PWR Severe Accident, the core materials discharge into the lower plenum in which water is still present. In that case, we are then concerned by the possible occurrence of a Steam Explosion which may endanger the vessel structure and by the following cooling of the melt debris. So, we have two possible ways of vessel rupture: a mechanical one following an energetic Steam Explosion and a thermal one due to insufficient debris cooling. Both types of problems are linked with the degree of fragmentation of the core material during its penetration into the water of the lower plenum. One of the most likely mode of discharge consists in corium streams or jets. The fragmentation will build a corium-water mixture (the pre-mixing sequence) which, under certain circumstances, may undergo a fine fragmentation sequence leading to an energetic Steam Explosion (the explosion sequence). Whatever the occurrence of a Steam Explosion, the resulting debris will accumulate at the bottom of the Reactor Vessel and the cooling of such a ''debris bed'' is known to be highly dependant of the granulometry and build up of the debris bed which are linked with the previous sequence of corium fragmentation and dispersion. In CEA, the MC3D Code has been developed to deal with all these phenomena. (author)

  4. Response of ultra-thin scintillator foils to fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Manduchi, C.; Russo-Manduchi, M.T.; Segato, G.F.

    1986-03-01

    Luminescence and timing properties of ultra-thin film detectors, with thicknesses ranging from 20 to 200 ..mu..g/cm/sup 2/, are compared. The light collection system, coupled to two selected and matched phototubes, provides an effective method for testing and comparing the properties of different detectors. Typical responses to /sup 252/Cf spontaneous fission fragments are presented in two-dimensional contour plots, relating to (i) residual energy of the fragments vs time-of-flight, (ii) light output vs time-of-flight, and (iii) light output vs residual energy. (orig.).

  5. Limiting Accretion onto Massive Stars by Fragmentation-Induced Starvation

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Thomas; /ZAH, Heidelberg; Klessen, Ralf S.; /ZAH, Heidelberg /KIPAC, Menlo Park; Mac Low, Mordecai-Mark; /Amer. Museum Natural Hist.; Banerjee, Robi; /ZAH, Heidelberg

    2010-08-25

    Massive stars influence their surroundings through radiation, winds, and supernova explosions far out of proportion to their small numbers. However, the physical processes that initiate and govern the birth of massive stars remain poorly understood. Two widely discussed models are monolithic collapse of molecular cloud cores and competitive accretion. To learn more about massive star formation, we perform simulations of the collapse of rotating, massive, cloud cores including radiative heating by both non-ionizing and ionizing radiation using the FLASH adaptive mesh refinement code. These simulations show fragmentation from gravitational instability in the enormously dense accretion flows required to build up massive stars. Secondary stars form rapidly in these flows and accrete mass that would have otherwise been consumed by the massive star in the center, in a process that we term fragmentation-induced starvation. This explains why massive stars are usually found as members of high-order stellar systems that themselves belong to large clusters containing stars of all masses. The radiative heating does not prevent fragmentation, but does lead to a higher Jeans mass, resulting in fewer and more massive stars than would form without the heating. This mechanism reproduces the observed relation between the total stellar mass in the cluster and the mass of the largest star. It predicts strong clumping and filamentary structure in the center of collapsing cores, as has recently been observed. We speculate that a similar mechanism will act during primordial star formation.

  6. Linkage map of the fragments of herpesvirus papio DNA.

    Science.gov (United States)

    Lee, Y S; Tanaka, A; Lau, R Y; Nonoyama, M; Rabin, H

    1981-01-01

    Herpesvirus papio (HVP), an Epstein-Barr-like virus, causes lymphoblastoid disease in baboons. The physical map of HVP DNA was constructed for the fragments produced by cleavage of HVP DNA with restriction endonucleases EcoRI, HindIII, SalI, and PvuI, which produced 12, 12, 10, and 4 fragments, respectively. The total molecular size of HVP DNA was calculated as close to 110 megadaltons. The following methods were used for construction of the map; (i) fragments near the ends of HVP DNA were identified by treating viral DNA with lambda exonuclease before restriction enzyme digestion; (ii) fragments containing nucleotide sequences in common with fragments from the second enzyme digest of HVP DNA were examined by Southern blot hybridization; and (iii) the location of some fragments was determined by isolating individual fragments from agarose gels and redigesting the isolated fragments with a second restriction enzyme. Terminal heterogeneity and internal repeats were found to be unique features of HVP DNA molecule. One to five repeats of 0.8 megadaltons were found at both terminal ends. Although the repeats of both ends shared a certain degree of homology, it was not determined whether they were identical repeats. The internal repeat sequence of HVP DNA was found in the EcoRI-C region, which extended from 8.4 to 23 megadaltons from the left end of the molecule. The average number of the repeats was calculated to be seven, and the molecular size was determined to be 1.8 megadaltons. Similar unique features have been reported in EBV DNA (D. Given and E. Kieff, J. Virol. 28:524-542, 1978). Images PMID:6261015

  7. Bicistronic DNA display for in vitro selection of Fab fragments.

    Science.gov (United States)

    Sumida, Takeshi; Doi, Nobuhide; Yanagawa, Hiroshi

    2009-12-01

    In vitro display methods are superior tools for obtaining monoclonal antibodies. Although totally in vitro display methods, such as ribosome display and mRNA display, have the advantages of larger library sizes and quicker selection procedures compared with phage display, their applications have been limited to single-chain Fvs due to the requirement for linking of the mRNA and the nascent protein on the ribosome. Here we describe a different type of totally in vitro method, DNA display, that is applicable to heterodimeric Fab fragments: in vitro compartmentalization in water-in-oil emulsions allows the linking of an oligomeric protein and its encoding DNA with multiple ORFs. Since previously used emulsions impaired the synthesis of functional Fab fragments, we modified conditions for preparing emulsions, and identified conditions under which it was possible to enrich Fab fragments 10(6)-fold per three rounds of affinity selection. Furthermore, we confirmed that genes encoding stable Fab fragments could be selected from a Fab fragment library with a randomized hydrophobic core in the constant region by applying heat treatment as a selection pressure. Since this method has all advantages of both phage display and totally in vitro display, it represents a new option for many applications using display methods.

  8. The chemistry of protoplanetary fragments formed via gravitational instabilities

    Science.gov (United States)

    Ilee, J. D.; Forgan, D. H.; Evans, M. G.; Hall, C.; Booth, R.; Clarke, C. J.; Rice, W. K. M.; Boley, A. C.; Caselli, P.; Hartquist, T. W.; Rawlings, J. M. C.

    2017-11-01

    In this paper, we model the chemical evolution of a 0.25 M⊙ protoplanetary disc surrounding a 1 M⊙ star that undergoes fragmentation due to self-gravity. We use smoothed particle hydrodynamics including a radiative transfer scheme, along with a time-dependent chemical evolution code to follow the composition of the disc and resulting fragments over approximately 4000 yr. Initially, four quasi-stable fragments are formed, of which two are eventually disrupted by tidal torques in the disc. From the results of our chemical modelling, we identify species that are abundant in the fragments (e.g. H2O, H2S, HNO, N2, NH3, OCS, SO), species that are abundant in the spiral shocks within the disc (e.g. CO, CH4, CN, CS, H2CO) and species that are abundant in the circumfragmentary material (e.g. HCO+). Our models suggest that in some fragments it is plausible for grains to sediment to the core before releasing their volatiles into the planetary envelope, leading to changes in, e.g., the C/O ratio of the gas and ice components. We would therefore predict that the atmospheric composition of planets generated by gravitational instability should not necessarily follow the bulk chemical composition of the local disc material.

  9. Fragmentation and ablation during entry

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1997-09-01

    This note discusses objects that both fragment and ablate during entry, using the results of previous reports to describe the velocity, pressure, and fragmentation of entering objects. It shows that the mechanisms used there to describe the breakup of non-ablating objects during deceleration remain valid for most ablating objects. It treats coupled fragmentation and ablation during entry, building on earlier models that separately discuss the entry of objects that are hard, whose high heat of ablation permits little erosion, and those who are strong whose strength prevents fragmentation, which are discussed in ``Radiation from Hard Objects,`` ``Deceleration and Radiation of Strong, Hard, Asteroids During Atmospheric Impact,`` and ``Meteor Signature Interpretation.`` This note provides a more detailed treatment of the further breakup and separation of fragments during descent. It replaces the constraint on mass per unit area used earlier to determine the altitude and magnitude of peak power radiation with a detailed analytic solution of deceleration. Model predictions are shown to be in agreement with the key features of numerical calculations of deceleration. The model equations are solved for the altitudes of maximum radiation, which agree with numerical integrations. The model is inverted analytically to infer object size and speed from measurements of peak power and altitude to provide a complete model for the approximate inversion of meteor data.

  10. Inner Core Rotation from Geomagnetic Westward Drift and a Stationary Spherical Vortex in Earth's Core

    Science.gov (United States)

    Voorhies, C. V.

    1999-01-01

    The idea that geomagnetic westward drift indicates convective leveling of the planetary momentum gradient within Earth's core is pursued in search of a differentially rotating mean state, upon which various oscillations and secular effects might be superimposed. The desired state conforms to roughly spherical boundary conditions, minimizes dissipative interference with convective cooling in the bulk of the core, yet may aide core cooling by depositing heat in the uppermost core and lower mantle. The variational calculus of stationary dissipation applied to a spherical vortex within the core yields an interesting differential rotation profile akin to spherical Couette flow bounded by thin Hartmann layers. Four boundary conditions are required. To concentrate shear induced dissipation near the core-mantle boundary, these are taken to be: (i) no-slip at the core-mantle interface; (ii) geomagnetically estimated bulk westward flow at the base of the core-mantle boundary layer; (iii) no-slip at the inner-outer core interface; and, to describe magnetic locking of the inner core to the deep outer core, (iv) hydrodynamically stress-free at the inner-outer core boundary. By boldly assuming the axial core angular momentum anomaly to be zero, the super-rotation of the inner core is calculated to be at most 1.5 degrees per year.

  11. A thermodynamic theory of dynamic fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Yew, Ching H. [Texas Univ., Austin, TX (United States); Taylor, P.A. [Sandia National Labs., Albuquerque, NM (United States)

    1993-08-01

    We present a theory of dynamic fragmentation of brittle materials based on thermodynamic arguments. We recover the expressions for average fragment size and number as originally derived by Grady. We extend the previous work by obtaining descriptions of fragment size distribution and compressibility change due to the fragmentation process. The size distribution is assumed to be proportional to the spectral power of the strain history and a sample distribution is presented for a fragmentation process corresponding to a constant rate strain history. The description of compressibility change should be useful in computational studies of fragmentation. These results should provide insight into the process of fragmentation of brittle materials from hypervelocity impact.

  12. Hierarchical Fragmentation in the Perseus Molecular Cloud: From the Cloud Scale to Protostellar Objects

    Science.gov (United States)

    Pokhrel, Riwaj; Myers, Philip C.; Dunham, Michael M.; Stephens, Ian W.; Sadavoy, Sarah I.; Zhang, Qizhou; Bourke, Tyler L.; Tobin, John J.; Lee, Katherine I.; Gutermuth, Robert A.; Offner, Stella S. R.

    2018-01-01

    We present a study of hierarchical structure in the Perseus molecular cloud, from the scale of the entire cloud (≳ 10 pc) to smaller clumps (∼1 pc), cores (∼0.05–0.1 pc), envelopes (∼300–3000 au), and protostellar objects (∼15 au). We use new observations from the Submillimeter Array (SMA) large project “Mass Assembly of Stellar Systems and their Evolution with the SMA (MASSES)” to probe the envelopes, and recent single-dish and interferometric observations from the literature for the remaining scales. This is the first study to analyze hierarchical structure over five scales in the same cloud complex. We compare the number of fragments with the number of Jeans masses in each scale to calculate the Jeans efficiency, or the ratio of observed to expected number of fragments. The velocity dispersion is assumed to arise either from purely thermal motions or from combined thermal and non-thermal motions inferred from observed spectral line widths. For each scale, thermal Jeans fragmentation predicts more fragments than observed, corresponding to inefficient thermal Jeans fragmentation. For the smallest scale, thermal plus non-thermal Jeans fragmentation also predicts too many protostellar objects. However, at each of the larger scales thermal plus non-thermal Jeans fragmentation predicts fewer than one fragment, corresponding to no fragmentation into envelopes, cores, and clumps. Over all scales, the results are inconsistent with complete Jeans fragmentation based on either thermal or thermal plus non-thermal motions. They are more nearly consistent with inefficient thermal Jeans fragmentation, where the thermal Jeans efficiency increases from the largest to the smallest scale.

  13. A rapid and convergent synthesis of the integrastatin core

    KAUST Repository

    Tadross, Pamela M.

    2011-01-01

    The tetracyclic core of the integrastatin natural products has been prepared in a convergent and rapid manner. Our strategy relies upon a palladium(ii)-catalyzed oxidative cyclization to form the central [3.3.1]-dioxabicycle of the natural product core. Overall, the core has been completed in only 4 linear steps from known compounds. © 2011 The Royal Society of Chemistry.

  14. Population pressure and farm fragmentation:

    African Journals Online (AJOL)

    user

    Small farmers play a dominant role in rural area in Rwanda according to many researchers. These farmers have some particular characteristics: most of them have tiny farms, while purchasing and borrowing of land are frequent. In addition, the size of farms is not only very small but farms are further fragmented into ...

  15. Fragmentation of stretched liquid ligaments

    NARCIS (Netherlands)

    Marmottant, P.G.M.; Villermaux, Emmanuel

    2004-01-01

    The dynamics and fragmentation of stretched liquid ligaments is investigated. The ligaments are produced by the withdrawal of a tube initially dipping at a free surface. Time resolved high speed motion experiments reveal two different elongation behaviors, depending on the nondimensional number t,

  16. Fragmented nature: consequences for biodiversity

    NARCIS (Netherlands)

    Olff, H.; Ritchie, M.E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species

  17. Fragmented nature : consequences for biodiversity

    NARCIS (Netherlands)

    Olff, Han; Ritchie, Mark E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species

  18. Memory and change through Le Corbusier. Fragments of urban views

    OpenAIRE

    Gorgeri, Fabiola

    2016-01-01

    [EN] In the urban project of Le Corbusier the relationship between new and existing is opportunity of poetic composition. The real traces of the past of one place are transformative tools by which the new project is developed. The projects after World War II, like reconstruction project of Saint-Dié, are occasions to reflect about the new urban developments, rapid and extensive, and the relation of them with the landscape in a new territorial vision. The fragments of past and the ...

  19. The status of the Munich Fission Fragment Accelerator Project

    Science.gov (United States)

    Groß, M.; Habs, D.; Kester, O.; Ott, J.; Rao, R.; Thirolf, P.; Egidy, T. v.; Kienle, P.; Köster, U.; Steichele, E.

    1998-10-01

    At the new Munich high-flux reactor FRM-II, which is currently under construction and will have properties similar to the ILL reactor, a fission fragment accelerator—similar to the former Grenoble PIAFE project—is under design and will be able to provide very intense ion beams of neutron-rich nuclei. A status report of this project is given with emphasis on new developments concerning the in-pile part of the arrangement.

  20. The VERDI fission fragment spectrometer

    Directory of Open Access Journals (Sweden)

    Frégeau M.O.

    2013-12-01

    Full Text Available The VERDI time-of-flight spectrometer is dedicated to measurements of fission product yields and of prompt neutron emission data. Pre-neutron fission-fragment masses will be determined by the double time-of-flight (TOF technique. For this purpose an excellent time resolution is required. The time of flight of the fragments will be measured by electrostatic mirrors located near the target and the time signal coming from silicon detectors located at 50 cm on both sides of the target. This configuration, where the stop detector will provide us simultaneously with the kinetic energy of the fragment and timing information, significantly limits energy straggling in comparison to legacy experimental setup where a thin foil was usually used as a stop detector. In order to improve timing resolution, neutron transmutation doped silicon will be used. The high resistivity homogeneity of this material should significantly improve resolution in comparison to standard silicon detectors. Post-neutron fission fragment masses are obtained form the time-of-flight and the energy signal in the silicon detector. As an intermediary step a diamond detector will also be used as start detector located very close to the target. Previous tests have shown that poly-crystalline chemical vapour deposition (pCVD diamonds provides a coincidence time resolution of 150 ps not allowing complete separation between very low-energy fission fragments, alpha particles and noise. New results from using artificial single-crystal diamonds (sCVD show similar time resolution as from pCVD diamonds but also sufficiently good energy resolution.

  1. Fragmentation

    Science.gov (United States)

    K.H. Riitters

    2009-01-01

    Effective resource management takes into account the administrative and biophysical settings within which natural resources occur. A setting may be described in many ways; for example, by forest land ownership, by reserved and roadless designation, or by the distribution of human populations in relation to forest (chapter 3). The physical arrangement of forest in a...

  2. Structure/function relationships of bovine prothrombin fragment 1

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, J.S.

    1987-01-01

    The objective of this investigation was to evaluate the unique contribution of the N-terminal 33 residues of prothrombin, the Gla domain, to the Ca(II) and phospholipid binding properties of prothrombin. Prothrombin fragment 1 contains the Gla domain and is often used to study the Ca(II) and phospholipid binding properties of prothrombin. Two Gla domain peptides, 1-42 and 1-45, produced by chymotryptic cleavage of F-1 and isolated by anion-exchange chromatography were utilized to characterize the Gla domain of prothrombin. All experiments with Gla domain peptides was conducted at Ca(II) concentrations less than 2 mM since these peptides will precipitate from the solution at Ca(II) concentrations greater than 2 mM. Examinations of the properties of the Gla domain peptides was undertaken by several experimental approaches. In contrast to F-1, the intrinsic fluorescence of both 1-42 and 1-45 was not quenched upon the addition of 1 mM Ca(II) or any concentration of Mg(II). Equilibrium dialysis studies indicated that 1-42 binds three Ca(II) ions non-cooperatively. Similar studies using F-1 have shown positive cooperativity and seven Ca(II) ion binding sites. Gel permeation chromatography revealed that radioiodinated 1-45 dimerizes at the peptide concentration utilized in the equilibrium dialysis studies.

  3. Animal MRI Core

    Data.gov (United States)

    Federal Laboratory Consortium — The Animal Magnetic Resonance Imaging (MRI) Core develops and optimizes MRI methods for cardiovascular imaging of mice and rats. The Core provides imaging expertise,...

  4. Fragment separator momentum compression schemes

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, Laura, E-mail: bandura@anl.gov [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Erdelyi, Bela [Argonne National Laboratory, Argonne, IL 60439 (United States); Northern Illinois University, DeKalb, IL 60115 (United States); Hausmann, Marc [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Kubo, Toshiyuki [RIKEN Nishina Center, RIKEN, Wako (Japan); Nolen, Jerry [Argonne National Laboratory, Argonne, IL 60439 (United States); Portillo, Mauricio [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Sherrill, Bradley M. [National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States)

    2011-07-21

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  5. Fragment separator momentum compression schemes.

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, L.; Erdelyi, B.; Hausmann, M.; Kubo, T.; Nolen, J.; Portillo, M.; Sherrill, B.M. (Physics); (MSU); (Northern Illinois Univ.); (RIKEN)

    2011-07-21

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  6. Fragment separator momentum compression schemes

    Science.gov (United States)

    Bandura, Laura; Erdelyi, Bela; Hausmann, Marc; Kubo, Toshiyuki; Nolen, Jerry; Portillo, Mauricio; Sherrill, Bradley M.

    2011-07-01

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  7. Fragmentering og korridorer i landskabet

    DEFF Research Database (Denmark)

    Hammershøj, M.; Madsen, A. B.

    , at fragmentering af habitater resulterer i en reduktion og isolering af mange plante- og dyrepopulationer. Det er desuden vist, at korridorer har en funktion som habitater, hvilket er medvirkende til, at et område med korridorer kan huse flere arter og individer end et tilsvarende område uden korridorer. Der......Rapporten indeholder en litteraturudredning, der er baseret på en bearbejdning af den tilgængelige nationale og internationale litteratur omhandlende fragmentering og korridorer på det botaniske og zoologiske område. I alt 1.063 titler ligger til grund for udredningen. Udredningen har vist...... mangler dog entydige beviser for, at korridorer kan være af afgørende betydning for rekolonisering af habitater, i hvilke en given art er forsvundet. Afslutningsvis gives en liste med forskningsbehov samt en række anbefalinger....

  8. Fragmentation in the biopharmaceutical industry.

    Science.gov (United States)

    Goldsmith, Andrew D; Varela, Francisco E

    2017-02-01

    The large number of biopharmaceutical mergers and acquisitions (M&A) that occurred over the past decade has generated questions about whether the industry is consolidating around too-few players, negatively impacting both the number of medicines developed and overall innovation. However, closer examination of the level of biopharmaceutical consolidation by prescription sales shows that the industry was more fragmented in 2015 than in 2003. The trend towards increasing fragmentation is also observed across noncommercial and independent metrics over the same time period. The number and size of M&A deals has masked an active and competitive marketplace in which market growth and the number of companies entering the market exceeded the apparent reduction in the number of players caused by acquisitions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. A Search for Starless Core Substructure in Ophiuchus

    Science.gov (United States)

    Kirk, Helen

    2017-06-01

    Density substructure is expected in evolved starless cores: a single peak to form a protostar, or multiple peaks from fragmentation. Searches for this substructure have had mixed success. In an ALMA survey of Ophiuchus, we find two starless cores with signs of substructure, consistent with simulation predictions. A similar survey in Chameleon (Dunham et al. 2016) had no detections, despite expecting at least two. Our results suggest that Chamleon may lack a more evolved starless cores. Future ALMA observations will better trace the influence of environment on core substructure formation.

  10. Carcinogenesis of Depleted Uranium Fragments.

    Science.gov (United States)

    1996-02-01

    29 of 54 Chinese hamsters injected intravenously with a relatively high dose of Thorotrast (> 0.4 Bq/g) developed fibrosarcomas from perivascular...leakage of some injections (Guilmette et al., 1989). Plutonium fragments have been injected into the footpads of dogs to simulate the plutonium...extensively studied in animals, particularly in rats (Haley, 1982; Haley et al., 1982; Diamond et al., 1987; Morrow et al., 1982) and dogs (Morrow et al

  11. Modeling of Fragmentation of Asteroids

    Science.gov (United States)

    Agrawal, Parul; Prabhu, Dinesh K.; Carlozzi, Alexander; Hart, Kenneth; Bryson, Katie; Sears, Derek

    2015-01-01

    The objective of this study is to understand fragmentation and fracture of a given asteroid and mechanisms of break-up. The focus of the present work is to develop modeling techniques for stony asteroids in 10m-100m range to answer two questions: 1) What is the role of material makeup of an asteroid in the stress distribution? 2)How is stress distribution altered in the presence of pre-existing defects?

  12. Structure, fragmentation and fracture functions

    CERN Document Server

    Canal-Garcia, C A

    2000-01-01

    We address the partonic description of the proton, the photon and the "color singlet, " as seen in inclusive and semi-inclusive DIS, in e /sup +/e/sup $/collisions, and in diffractive processes, respectively. Their formal treatment using structure, fragmentation, and fracture functions is outlined giving an insight into the perturbative QCD framework for these functions. Examples and comparisons with experimental data from LEP, HERA, and Tevatron are also covered. (52 refs).

  13. Fibril fragmentation enhances amyloid cytotoxicity.

    Science.gov (United States)

    Xue, Wei-Feng; Hellewell, Andrew L; Gosal, Walraj S; Homans, Steve W; Hewitt, Eric W; Radford, Sheena E

    2009-12-04

    Fibrils associated with amyloid disease are molecular assemblies of key biological importance, yet how cells respond to the presence of amyloid remains unclear. Cellular responses may not only depend on the chemical composition or molecular properties of the amyloid fibrils, but their physical attributes such as length, width, or surface area may also play important roles. Here, we report a systematic investigation of the effect of fragmentation on the structural and biological properties of amyloid fibrils. In addition to the expected relationship between fragmentation and the ability to seed, we show a striking finding that fibril length correlates with the ability to disrupt membranes and to reduce cell viability. Thus, despite otherwise unchanged molecular architecture, shorter fibrillar samples show enhanced cytotoxic potential than their longer counterparts. The results highlight the importance of fibril length in amyloid disease, with fragmentation not only providing a mechanism by which fibril load can be rapidly increased but also creating fibrillar species of different dimensions that can endow new or enhanced biological properties such as amyloid cytotoxicity.

  14. Residual Fragments after Percutaneous Nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Kaan Özdedeli

    2012-09-01

    Full Text Available Clinically insignificant residual fragments (CIRFs are described as asymptomatic, noninfectious and nonobstructive stone fragments (≤4 mm remaining in the urinary system after the last session of any intervention (ESWL, URS or PCNL for urinary stones. Their insignificance is questionable since CIRFs could eventually become significant, as their presence may result in recurrent stone growth and they may cause pain and infection due to urinary obstruction. They may become the source of persistent infections and a significant portion of the patients will have a stone-related event, requiring auxilliary interventions. CT seems to be the ultimate choice of assessment. Although there is no concensus about the timing, recent data suggests that it may be performed one month after the procedure. However, imaging can be done in the immediate postoperative period, if there are no tubes blurring the assessment. There is some evidence indicating that selective medical therapy may have an impact on decreasing stone formation rates. Retrograde intrarenal surgery, with its minimally invasive nature, seems to be the best way to deal with residual fragments.

  15. A Method for Predicting Fragmentation Characteristics of Natural and Performed Explosive Fragmentation Munitions

    National Research Council Canada - National Science Library

    Gold, Vladimir

    2001-01-01

    New methodology for simulating performance of explosive fragmentation munitions presented in this work integrates three-dimensional axisymmetric hydrocode analyses with analytical fragmentation modeling...

  16. Tropical forest degradation and recovery in fragmented landscapes — Simulating changes in tree community, forest hydrology and carbon balance

    Directory of Open Access Journals (Sweden)

    M. Dantas de Paula

    2015-01-01

    Averages from ten four-hectare simulations show forest biomass degradation lasting around 100 years. If edge effects cease, recovery of biomass lasts around 150 years. Carbon loss is especially intense during the first five years after fragmentation, resulting in a decline of over 5 Mg ha−1y−1 C. Finally, edges of large fragments face an evapotranspiration loss of 43% and total runoff gains of 57% in relation to core areas of large fragments, suggesting that fragmented landscapes can be of significantly lower value in terms of ecosystem services.

  17. Quantum Correlated Multi-Fragment Reaction Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Feagin, James M. [California State Univ., Fullerton, CA (United States)

    2017-06-30

    This grant supported research in basic atomic, molecular and optical physics related to the interactions of atoms with particles and fields. This report will focus on the 12 year period from 2004 to 2017, although the DOE–BES has supported my research every year since 1986. All of the support from the grant was used to pay summer salaries of the PI and students and travel to conferences and meetings. The results were in the form of publications in peer reviewed journals as well as conference invited talks and colloquiums. There were 12 peer reviewed publications in these 12+ years. Innovations in few-body science at molecular and nano levels are a critical component of on- going efforts to establish sustainable environmental and energy resources. The varied research paths taken will require the development of basic science on broad fronts with increasing flexi- bility to crossover technologies. We thus worked to extract understanding and quantum control of few-body microscopic systems based on our long-time experience with more conventional studies of correlated electrons and ions. Given the enormous advances over the past 20 years to our understanding of quantum cor- relations with photon interferometry, AMO collision science generally is ready to move beyond the one-particle, single-port momentum detection that has dominated collision physics since Rutherford. Nevertheless, our familiar theoretical tools for collision theory need to be up- graded to incorporate these more generalized measurement formalisms and ultimately to give incentive for a new generation of experiments. Our interest in these topics remains motivated by the recent surge in and success of exper- iments involving few-body atomic and molecular fragmentation and the detection of all the fragments. The research described here thus involved two parallel efforts with (i) emphasis on reaction imaging while (ii) pursuing longtime work on quantum correlated collective excitations.

  18. Encapsulation of a (H3O2)- unit in the aromatic core of a calix[6]arene closed by two Zn(II) ions at the small and large rims.

    Science.gov (United States)

    Coquière, David; Marrot, Jérôme; Reinaud, Olivia

    2006-10-01

    The coordination of a first Zn(II) ion to a calix[6]arene presenting three imidazolyl arms at the small rim and three aniline moieties at the large rim allows the binding of a second Zn(II) ion while hosting a (H3O2)- unit in the aromatic cavity.

  19. Arrangement of photosystem II supercomplexes in crystalline macrodomains within the thylakoid membrane of green plant chloroplasts

    NARCIS (Netherlands)

    Boekema, EJ; van Breemen, JFL; van Roon, H; Dekker, JP; Dekker, Jan P.

    2000-01-01

    The chloroplast thylakoid membrane of green plants is organized in stacked grana membranes and unstacked stroma membranes. We investigated the structural organization of Photosystem II (PSII) in paired grana membrane fragments by transmission electron microscopy. The membrane fragments were obtained

  20. Fragmentation of small carbon clusters, a review

    Energy Technology Data Exchange (ETDEWEB)

    Beroff, K. [Laboratoire des Collisions Atomiques et Moleculaires, CNRS and Universite Paris-Sud, batiment 351, 91405 Orsay Cedex (France)], E-mail: karine.beroff@u-psud.fr; Chabot, M. [Institut de Physique Nucleaire, CNRS-IN2P3 and Universite Paris-Sud, 91405 Orsay Cedex (France); Mezdari, F. [Laboratoire des Collisions Atomiques et Moleculaires, CNRS and Universite Paris-Sud, batiment 351, 91405 Orsay Cedex (France); Martinet, G.; Tuna, T. [Institut de Physique Nucleaire, CNRS-IN2P3 and Universite Paris-Sud, 91405 Orsay Cedex (France); Desesquelles, P. [Centre de Spectrometrie Nucleaire et Spectrometrie de Masse, Universite Paris-Sud and CNRS-IN2P3, batiment 104, 91405 Orsay Cedex (France); LePadellec, A. [Institut de Recherche sur les Systemes Atomiques et Moleculaires Complexes, Universite Paul Sabatier and CNRS, batiment 3R1B4, 31062 Toulouse Cedex 9 (France); Barat, M. [Laboratoire des Collisions Atomiques et Moleculaires, CNRS and Universite Paris-Sud, batiment 351, 91405 Orsay Cedex (France)

    2009-03-15

    An overview of the works devoted to fragmentation of small carbon clusters is given in a first part. Fragmentation of swift neutral and (multi) charged carbon clusters studied with the AGAT spectrometer is presented and discussed in a second part.

  1. Fragmentation of small carbon clusters, a review

    OpenAIRE

    Béroff, K.; Chabot, M.; Mezdari, F.; Martinet, G.; Tuna, T.; Désesquelles, P.; Le Padellec, Arnaud; Barat, M.

    2008-01-01

    An overview of the works devoted to fragmentation of small carbon clusters is given in a first part. Fragmentation of swift neutral and (multi) charged carbon clusters studied with the AGAT spectrometer is presented and discussed in a second part.

  2. Identification of amplified fragment length polymorphism (AFLP ...

    African Journals Online (AJOL)

    Identification of amplified fragment length polymorphism (AFLP) fragments linked to soybean mosaic virus resistance gene in Glycine soja and conversion to a sequence characterized amplified regions (SCAR) marker for rapid selection.

  3. Fragment Kinetic Energies and Modes of Fragment Formation

    Science.gov (United States)

    Odeh, T.; Bassini, R.; Begemann-Blaich, M.; Fritz, S.; Gaff-Ejakov, S. J.; Gourio, D.; Groß, C.; Immé, G.; Iori, I.; Kleinevoß, U.; Kunde, G. J.; Kunze, W. D.; Lynen, U.; Maddalena, V.; Mahi, M.; Möhlenkamp, T.; Moroni, A.; Müller, W. F.; Nociforo, C.; Ocker, B.; Petruzzelli, F.; Pochodzalla, J.; Raciti, G.; Riccobene, G.; Romano, F. P.; Saija, A.; Schnittker, M.; Schüttauf, A.; Schwarz, C.; Seidel, W.; Serfling, V.; Sfienti, C.; Trautmann, W.; Trzcinski, A.; Verde, G.; Wörner, A.; Xi, Hongfei; Zwieglinski, B.

    2000-05-01

    Kinetic energies of light fragments ( A<=10) from the decay of target spectators in 197Au+197Au collisions at 1000 MeV per nucleon have been measured with high-resolution telescopes at backward angles. Except for protons and apart from the observed evaporation components, the kinetic-energy spectra exhibit slope temperatures of about 17 MeV, independent of the particle species, but not corresponding to the thermal or chemical degrees of freedom at breakup. It is suggested that these slope temperatures may reflect the intrinsic Fermi motion and thus the bulk density of the spectator system at the instant of becoming unstable.

  4. Optimal Economic Landscapes with Habitat Fragmentation Effects

    OpenAIRE

    Lewis, David J.; Wu, JunJie

    2005-01-01

    Habitat fragmentation is widely considered a primary threat to biodiversity. This paper develops a theoretical model of land use to analyze the optimal conservation of landscapes when land quality is spatially heterogeneous and wildlife habitat is fragmented and socially valuable. When agriculture is the primary cause of fragmentation, we show that reforestation efforts should be targeted to the most fragmented landscapes with an aggregate share of forest equal to a threshold, defined by the ...

  5. Self-organized criticality in fragmenting

    DEFF Research Database (Denmark)

    Oddershede, L.; Dimon, P.; Bohr, J.

    1993-01-01

    The measured mass distributions of fragments from 26 fractured objects of gypsum, soap, stearic paraffin, and potato show evidence of obeying scaling laws; this suggests the possibility of self-organized criticality in fragmenting. The probability of finding a fragment scales inversely to a power...

  6. Scaling and four-quark fragmentation

    NARCIS (Netherlands)

    Scholten, O.; Bosveld, G. D.

    1991-01-01

    The conditions for a scaling behaviour from the fragmentation process leading to slow protons are discussed. The scaling referred to implies that the fragmentation functions depend on the light-cone momentum fraction only. It is shown that differences in the fragmentation functions for valence- and

  7. Population pressure and farm fragmentation: Challenges facing ...

    African Journals Online (AJOL)

    In addition, the size of farms is not only very small but farms are further fragmented into diminutive size fields due to increasing population pressure. The magnitude of fragmentation has increased overtime. Effects of population pressure and farm fragmentation are studied based on a survey of 200 households from Rusatira ...

  8. Alternative Modelling Approach to Spatial Harvest Scheduling with Respect to Fragmentation of Forest Ecosystem.

    Science.gov (United States)

    Marušák, Róbert; Kašpar, Jan; Hlavatý, Robert; Kotek, Václav; Kuželka, Karel; Vopěnka, Petr

    2015-11-01

    Fragmentation of the forests affects forest ecosystems by changing the composition, shape, and configuration of the resulting patches. Subsequently, the prevailing conditions vary between patches. The exposure to the sun decreases from the patch boundary to the patch interior and this forms core and edge areas within each patch. Forest harvesting and, in particular, the clear-cut management system which is still preferred in many European countries has a significant impact on forest fragmentation. There are many indices of measuring fragmentation: non-spatial and spatial. The non-spatial indices measure the composition of patches, while the spatial indices measure both the shape and configuration of the resulting patches. The effect of forest harvesting on fragmentation, biodiversity, and the environment is extensively studied; however, the integration of fragmentation indices in the harvest scheduling model is a new, novel approach. This paper presents a multi-objective integer model of harvest scheduling for clear-cut management system and presents a case study demonstrating its use. Harvest balance and sustainability are ensured by the addition of constraints from the basic principle of the regulated forest model. The results indicate that harvest balance and sustainability can be also achieved in minimizing fragmentation of forest ecosystems. From the analyses presented in this study, it can be concluded that integration of fragmentation into harvest scheduling can provide better spatial structure. It depends on the initial spatial and age structure. It was confirmed that it is possible to find compromise solution while minimizing fragmentation and maximizing harvested area.

  9. DRAG COEFFICIENTS FOR IRREGULAR FRAGMENTS

    Science.gov (United States)

    1986-08-01

    regular fragments.were studied In the report, I.e., a sphere, a c-ibe and a bar. Th.a bar length, 1530) 77= pp. P width and thickness were. in the ratio...measurements for the 96 fragmento are contained in Tables A-1, A-2 and A-3 of Appendix A. The esiential aspects of the vertical wind tunnel are shown...THICKNESS L’ MAXIMUM LENGTH P ..UPS AVERAGE LENGTH W’ M AXIMUM WIDTH PLUS AVERAGE WIDTH T’ M I’XIX1MUM THICKNESS PLUS AVERAIE THICKNESS i -- STANDARO DEVIATION

  10. Lead bullet fragments in venison from rifle-killed deer: potential for human dietary exposure.

    Directory of Open Access Journals (Sweden)

    W Grainger Hunt

    Full Text Available Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus shot by hunters with standard lead-core, copper-jacketed bullets under normal hunting conditions. All carcasses showed metal fragments (geometric mean = 136 fragments, range = 15-409 and widespread fragment dispersion. We took each carcass to a separate meat processor and fluoroscopically scanned the resulting meat packages; fluoroscopy revealed metal fragments in the ground meat packages of 24 (80% of the 30 deer; 32% of 234 ground meat packages contained at least one fragment. Fragments were identified as lead by ICP in 93% of 27 samples. Isotope ratios of lead in meat matched the ratios of bullets, and differed from background lead in bone. We fed fragment-containing venison to four pigs to test bioavailability; four controls received venison without fragments from the same deer. Mean blood lead concentrations in pigs peaked at 2.29 microg/dL (maximum 3.8 microg/dL 2 days following ingestion of fragment-containing venison, significantly higher than the 0.63 microg/dL averaged by controls. We conclude that people risk exposure to bioavailable lead from bullet fragments when they eat venison from deer killed with standard lead-based rifle bullets and processed under normal procedures. At risk in the U.S. are some ten million hunters, their families, and low

  11. Dihadron fragmentation functions for large invariant mass.

    Science.gov (United States)

    Zhou, J; Metz, A

    2011-04-29

    Using perturbative quantum chromodynamics, we compute dihadron fragmentation functions for a large invariant mass of the dihadron pair. The main focus is on the interference fragmentation function H(1)(∢), which plays an important role in spin physics of the nucleon. Our calculation also reveals that H(1)(∢) and the Collins fragmentation function have closely related underlying dynamics. By considering semi-inclusive deep-inelastic scattering, we further show that collinear factorization in terms of dihadron fragmentation functions and collinear factorization in terms of single-hadron fragmentation functions provide the same result in the region of intermediate invariant mass.

  12. Dependence of Fission-Fragment Properties On Excitation Energy For Neutron-Rich Actinides

    Directory of Open Access Journals (Sweden)

    Ramos D.

    2016-01-01

    Isotopic fission yields of 250Cf, 244Cm, 240Pu, 239Np and 238U are presented in this work. With this information, the average number of neutrons as a function of the atomic number of the fragments is calculated, which reflects the impact of nuclear structure around Z=50, N=80 on the production of fission fragments. The characteristics of the Super Long, Standard I, Standard II, and Standard III fission channels were extracted from fits of the fragment yields for different ranges of excitation energy. The position and contribution of the fission channels as function of excitation energy are presented.

  13. k -core covers and the core

    NARCIS (Netherlands)

    Sanchez-Rodriguez, E.; Borm, P.; Estevez Fernandez, M.A.; Fiestras-Janeiro, M.G.; Mosquera, M.A.

    2015-01-01

    This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

  14. k-core covers and the core

    NARCIS (Netherlands)

    Sanchez-Rodriguez, E.; Borm, Peter; Estevez-Fernandez, A.; Fiestras-Janeiro, G.; Mosquera, M.A.

    This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

  15. Reframing landscape fragmentation's effects on ecosystem services.

    Science.gov (United States)

    Mitchell, Matthew G E; Suarez-Castro, Andrés F; Martinez-Harms, Maria; Maron, Martine; McAlpine, Clive; Gaston, Kevin J; Johansen, Kasper; Rhodes, Jonathan R

    2015-04-01

    Landscape structure and fragmentation have important effects on ecosystem services, with a common assumption being that fragmentation reduces service provision. This is based on fragmentation's expected effects on ecosystem service supply, but ignores how fragmentation influences the flow of services to people. Here we develop a new conceptual framework that explicitly considers the links between landscape fragmentation, the supply of services, and the flow of services to people. We argue that fragmentation's effects on ecosystem service flow can be positive or negative, and use our framework to construct testable hypotheses about the effects of fragmentation on final ecosystem service provision. Empirical efforts to apply and test this framework are critical to improving landscape management for multiple ecosystem services. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Sleep fragmentation in canine narcolepsy.

    Science.gov (United States)

    Kaitin, K I; Kilduff, T S; Dement, W C

    1986-01-01

    Genetically narcoleptic dogs were recorded continuously for 24 h to examine their sleep-wake patterns and to evaluate the extent of sleep fragmentation. Three narcoleptic and three control dogs from each of two affected breeds (Labrador retrievers and Doberman pinschers) were surgically implanted with electrodes for recording standard sleep parameters. Recordings were scored in 30-s epochs for the states of active waking, drowsiness, light sleep, deep slow wave sleep, REM sleep, and cataplexy. All affected dogs displayed marked fragmentation and disruption of the sleep-wake cycle characterized by repeated awakenings, frequent shifts in sleep stages, numerous attacks of cataplexy occurring from active waking, and a disturbance of the normal REM-NREM periodicity. This sleep disruption was reflected in significantly greater numbers of episodes of each behavioral state as well as in a 38% increase in the total number of all states. These results demonstrate a severe disturbance of the normal sleep pattern in canine narcoleptics. The possibility of a general dysfunction of circadian organization is discussed.

  17. Conceptual study of advanced PWR core design. Development of advanced PWR core neutronics analysis system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Hyo; Kim, Seung Cho; Kim, Taek Kyum; Cho, Jin Young; Lee, Hyun Cheol; Lee, Jung Hun; Jung, Gu Young [Seoul National University, Seoul (Korea, Republic of)

    1995-08-01

    The neutronics design system of the advanced PWR consists of (i) hexagonal cell and fuel assembly code for generation of homogenized few-group cross sections and (ii) global core neutronics analysis code for computations of steady-state pin-wise or assembly-wise core power distribution, core reactivity with fuel burnup, control rod worth and reactivity coefficients, transient core power, etc.. The major research target of the first year is to establish the numerical method and solution of multi-group diffusion equations for neutronics code development. Specifically, the following studies are planned; (i) Formulation of various numerical methods such as finite element method(FEM), analytical nodal method(ANM), analytic function expansion nodal(AFEN) method, polynomial expansion nodal(PEN) method that can be applicable for the hexagonal core geometry. (ii) Comparative evaluation of the numerical effectiveness of these methods based on numerical solutions to various hexagonal core neutronics benchmark problems. Results are follows: (i) Formulation of numerical solutions to multi-group diffusion equations based on numerical methods. (ii) Numerical computations by above methods for the hexagonal neutronics benchmark problems such as -VVER-1000 Problem Without Reflector -VVER-440 Problem I With Reflector -Modified IAEA PWR Problem Without Reflector -Modified IAEA PWR Problem With Reflector -ANL Large Heavy Water Reactor Problem -Small HTGR Problem -VVER-440 Problem II With Reactor (iii) Comparative evaluation on the numerical effectiveness of various numerical methods. (iv) Development of HEXFEM code, a multi-dimensional hexagonal core neutronics analysis code based on FEM. In the target year of this research, the spatial neutronics analysis code for hexagonal core geometry(called NEMSNAP-H temporarily) will be completed. Combination of NEMSNAP-H with hexagonal cell and assembly code will then equip us with hexagonal core neutronics design system. (Abstract Truncated)

  18. Single chain Fab (scFab fragment

    Directory of Open Access Journals (Sweden)

    Brenneis Mariam

    2007-03-01

    Full Text Available Abstract Background The connection of the variable part of the heavy chain (VH and and the variable part of the light chain (VL by a peptide linker to form a consecutive polypeptide chain (single chain antibody, scFv was a breakthrough for the functional production of antibody fragments in Escherichia coli. Being double the size of fragment variable (Fv fragments and requiring assembly of two independent polypeptide chains, functional Fab fragments are usually produced with significantly lower yields in E. coli. An antibody design combining stability and assay compatibility of the fragment antigen binding (Fab with high level bacterial expression of single chain Fv fragments would be desirable. The desired antibody fragment should be both suitable for expression as soluble antibody in E. coli and antibody phage display. Results Here, we demonstrate that the introduction of a polypeptide linker between the fragment difficult (Fd and the light chain (LC, resulting in the formation of a single chain Fab fragment (scFab, can lead to improved production of functional molecules. We tested the impact of various linker designs and modifications of the constant regions on both phage display efficiency and the yield of soluble antibody fragments. A scFab variant without cysteins (scFabΔC connecting the constant part 1 of the heavy chain (CH1 and the constant part of the light chain (CL were best suited for phage display and production of soluble antibody fragments. Beside the expression system E. coli, the new antibody format was also expressed in Pichia pastoris. Monovalent and divalent fragments (DiFabodies as well as multimers were characterised. Conclusion A new antibody design offers the generation of bivalent Fab derivates for antibody phage display and production of soluble antibody fragments. This antibody format is of particular value for high throughput proteome binder generation projects, due to the avidity effect and the possible use of

  19. Photo-fragmentation of the closo-carboranes Part 1: Energetics of Decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Kilcoyne, Arthur L; Feng, Danqin; Liu, Jing; Hitchcock, Adam P.; Kilcoyne, A.L. David; Tyliszczak, Tolek; Riehs, Norman F.; R& #252; hl, Eckart; Bozek, John D.; McIlroy, David; Dowben, Peter A.

    2007-11-09

    The ionic fragmentation following B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-dicarbadodecaboranes: orthocarborane (1,2-C2B10H12), metacarborane (1,7-C2B10H12), and paracarborane (1,12-C2B10H12)], is compared with the energetics of decomposition. The fragmentation yields for all three molecules are quite similar. Thermodynamic cycles are constructed for neutral and ionic species in an attempt to systemically characterize single ion closo-carborane creation and fragmentation processes. Lower energy decomposition processes are favored. Among the ionic species, the photon induced decomposition isdominated by BH+ and BH2+ fragment loss. Changes in ion yield associated with core to bound excitations are observed.

  20. Species-genetic diversity correlations in habitat fragmentation can be biased by small sample sizes.

    Science.gov (United States)

    Nazareno, Alison G; Jump, Alistair S

    2012-06-01

    Predicted parallel impacts of habitat fragmentation on genes and species lie at the core of conservation biology, yet tests of this rule are rare. In a recent article in Ecology Letters, Struebig et al. (2011) report that declining genetic diversity accompanies declining species diversity in tropical forest fragments. However, this study estimates diversity in many populations through extrapolation from very small sample sizes. Using the data of this recent work, we show that results estimated from the smallest sample sizes drive the species-genetic diversity correlation (SGDC), owing to a false-positive association between habitat fragmentation and loss of genetic diversity. Small sample sizes are a persistent problem in habitat fragmentation studies, the results of which often do not fit simple theoretical models. It is essential, therefore, that data assessing the proposed SGDC are sufficient in order that conclusions be robust.

  1. Ionic fragmentation of the isoprene molecule in the VUV energy range (12 to 310 eV)

    Energy Technology Data Exchange (ETDEWEB)

    Bernini, R.B., E-mail: rafael.bernini@ifrj.edu.br [Instituto Federal de Ciência e Tecnologia do Rio de Janeiro (IFRJ), 25050-100 Duque de Caxias, RJ (Brazil); Coutinho, L.H. [Instituto de Física, Universidade Federal do Rio De Janeiro (UFRJ), 21941-972 Rio de Janeiro, RJ (Brazil); Nunez, C.V. [Laboratório de Bioprospecção e Biotecnologia, Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da Amazônia (INPA), 69060-001 Manaus, AM (Brazil); Castilho, R.B. de [Departamento de Química, Instituto de Ciências Exatas, Universidade Federal do Amazonas (UFAM), 69077-000 Manaus, AM (Brazil); Souza, G.G.B. de [Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), 21949-900 Rio de Janeiro, RJ (Brazil)

    2015-07-15

    Highlights: • Ionic fragmentation of isoprene following valence-shell and C 1s excitation. • Experimental observation of single and double ionization processes. • Large increase in fragmentation following core excitation. • Similar dissociation pattern bellow (270 eV) and above (310 eV) core edge. • Stable molecular ion observed at all photon energies. - Abstract: Isoprene, C{sub 5}H{sub 8}, is a biogenic volatile compound emitted from plants and animals, playing an important role in atmospheric chemistry. In this work, we have studied the ionic fragmentation of the isoprene molecule induced by high energy photons (synchrotron radiation), both at the valence (12.0, 14.0, 16.0, 18.0, and 21.0 eV) and carbon 1s edge (270 and 310 eV, respectively, below and above edge) energies. The ionic fragments were mass-analyzed using a Wiley–McLaren time-of-flight spectrometer (TOF) and single (PEPICO) and double ionization coincidence (PEPIPICO) spectra were obtained. As expected, the fragmentation degree increases with increasing energy. Below and above the carbon 1s edge, the fragmentation patterns are quite similar, and basically the same fragments are observed as compared to the spectra following valence-shell ionization. Stable doubly-charged ions were not observed. A PEPIPICO spectrum has shown that the main dissociation route for doubly-ionized species corresponds to the [CH{sub 3}]{sup +}/[C{sub 4}H{sub 2–5}]{sup +} ion pair. Intense fragmentation of the isoprene molecule has been observed following valence shell and core electron ionization. The observance of basically the same fragments when moving from valence to inner-shell suggests that basically the same fragmentation routes are present in both cases. All doubly (or multiply)-charged cations are unstable, at least on a microsecond scale.

  2. A new assay based on terminal restriction fragment length polymorphism of homocitrate synthase gene fragments for Candida species identification.

    Science.gov (United States)

    Szemiako, Kasjan; Śledzińska, Anna; Krawczyk, Beata

    2017-08-01

    Candida sp. have been responsible for an increasing number of infections, especially in patients with immunodeficiency. Species-specific differentiation of Candida sp. is difficult in routine diagnosis. This identification can have a highly significant association in therapy and prophylaxis. This work has shown a new application of the terminal restriction fragment length polymorphism (t-RFLP) method in the molecular identification of six species of Candida, which are the most common causes of fungal infections. Specific for fungi homocitrate synthase gene was chosen as a molecular target for amplification. The use of three restriction enzymes, DraI, RsaI, and BglII, for amplicon digestion can generate species-specific fluorescence labeled DNA fragment profiles, which can be used to determine the diagnostic algorithm. The designed method can be a cost-efficient high-throughput molecular technique for the identification of six clinically important Candida species.

  3. Fragmentation in Carbon Therapy Beams

    CERN Document Server

    Charara, Y M

    2010-01-01

    The state of the art Monte Carlo code HETC-HEDS was used to simulate spallation products, secondary neutron, and secondary proton production in A-150 Tissue Equivalent Plastic phantoms to investigate fragmentation of carbon therapy beams. For a 356 MeV/Nucleon carbon ion beam, production of charged particles heavier than protons was 0.24 spallation products per incident carbon ion with atomic numbers ranging from 1 through 5 (hydrogen to boron). In addition, there were 4.73 neutrons and 2.95 protons produced per incident carbon ion. Furthermore, as the incident energy increases, the neutron production rate increases at a rate of 20% per 10 MeV/nucleon. Secondary protons were created at a rate between 2.62-2.87 per carbon ion, while spallation products were created at a rate between 0.20-0.24 per carbon ion.

  4. Fluid fragmentation from hospital toilets

    CERN Document Server

    Traverso, G; Lu, C -C; Maa, R; Langer, R; Bourouiba, L

    2013-01-01

    Hospital-acquired infections represent significant health and financial burdens to society. Clostridium difficile (C. difficile) is a particularly challenging bacteria with the potential to cause severe diarrhea and death. One mode of transmission for C. difficile, as well as other pathogens, which has received little attention is the potential air contamination by pathogen-bearing droplets emanating from toilets. In the fluid dynamics video submitted to the APS DFD Gallery of Fluid Motion 2013, we present flow visualizations via high-speed recordings showing the capture of the product of the fluid fragmentation generated by hospital toilet high-pressure flushes. Important quantities of both large and small droplets are observed. We illustrate how high-pressure flushes and cleaning products currently used in hospital toilets result in aggravating, rather than alleviating, the suspension and recirculation of tenacious airborne pathogen-bearing droplets.

  5. High yield DNA fragmentation using cyclical hydrodynamic shearing

    NARCIS (Netherlands)

    Shui, Lingling; Sparreboom, Wouter; Spang, Peter; Roeser, Tina; Nieto, Benjamin; Guasch, Francesc; Corbera, Antoni Homs; van den Berg, Albert; Carlen, Edwin

    2013-01-01

    We report a new DNA fragmentation technique that significantly simplifies conventional hydrodynamic shearing fragmentation by eliminating the need for sample recirculation while maintaining high fragmentation yield and low fragment length variation, and therefore, reduces instrument complexity and

  6. Multi-core Microprocessors

    Indian Academy of Sciences (India)

    programming and computer fundamentals. His current research interests are parallel computing and history of computing. Multi-core microprocessor is an interconnected set of inde- pendent processors called cores integrated on a single sili- con chip. These processing cores communicate and cooperate with one another ...

  7. Core Competence and Education.

    Science.gov (United States)

    Holmes, Gary; Hooper, Nick

    2000-01-01

    Outlines the concept of core competence and applies it to postcompulsory education in the United Kingdom. Adopts an educational perspective that suggests accreditation as the core competence of universities. This economic approach suggests that the market trend toward lifetime learning might best be met by institutions developing a core competence…

  8. WHAT IS CONTROLLING THE FRAGMENTATION IN THE INFRARED DARK CLOUD G14.225–0.506?: DIFFERENT LEVELS OF FRAGMENTATION IN TWIN HUBS

    Energy Technology Data Exchange (ETDEWEB)

    Busquet, Gemma; Girart, Josep Miquel [Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193, Cerdanyola del Vallès, Catalunya (Spain); Estalella, Robert [Departament d’Astronomia i Meteorologia, Institut de Ciències del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Martí i Franquès, 1, E-08028 Barcelona, Catalunya (Spain); Palau, Aina [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, P.O. Box 3-72, 58090 Morelia, Michoacán, México (Mexico); Liu, Hauyu Baobab; Ho, Paul T. P. [Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan (China); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); De Gregorio-Monsalvo, Itziar [European Southern Observatory (ESO), Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Pillai, Thushara [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Anglada, Guillem, E-mail: busquet@ice.cat [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía, s/n, E-18008, Granada (Spain)

    2016-03-20

    We present observations of the 1.3 mm continuum emission toward hub-N and hub-S of the infrared dark cloud G14.225–0.506 carried out with the Submillimeter Array, together with observations of the dust emission at 870 and 350 μm obtained with APEX and CSO telescopes. The large-scale dust emission of both hubs consists of a single peaked clump elongated in the direction of the associated filament. At small scales, the SMA images reveal that both hubs fragment into several dust condensations. The fragmentation level was assessed under the same conditions and we found that hub-N presents 4 fragments while hub-S is more fragmented, with 13 fragments identified. We studied the density structure by means of a simultaneous fit of the radial intensity profile at 870 and 350 μm and the spectral energy distribution adopting a Plummer-like function to describe the density structure. The parameters inferred from the model are remarkably similar in both hubs, suggesting that density structure could not be responsible for determining the fragmentation level. We estimated several physical parameters, such as the level of turbulence and the magnetic field strength, and we found no significant differences between these hubs. The Jeans analysis indicates that the observed fragmentation is more consistent with thermal Jeans fragmentation compared with a scenario in which turbulent support is included. The lower fragmentation level observed in hub-N could be explained in terms of stronger UV radiation effects from a nearby H ii region, evolutionary effects, and/or stronger magnetic fields at small scales, a scenario that should be further investigated.

  9. Fragment-based drug discovery and protein–protein interactions

    Directory of Open Access Journals (Sweden)

    Turnbull AP

    2014-09-01

    -dimensional character. These physiochemical properties can potentially be exploited in the rational design of PPI-specific fragment libraries and correlate well with optimized PPI inhibitors, which tend to have properties outside currently accepted guidelines for drug-likeness. Several examples of small-molecule PPI inhibitors derived from fragment-based drug discovery now exist and are described in this review, including navitoclax, a novel Bcl-2 family inhibitor which has entered Phase II clinical trials in patients with small-cell lung cancer and chronic lymphocytic leukemia.Keywords: hot spot, druggability, ligandability

  10. Filter for interpretation of fragmentation during entry

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1997-10-01

    Objects that fragment cascade and decelerate abruptly, producing short, bright, signatures which can be used to estimate object diameter and speed. Other objects can be incorporated into a generalized fragmentation filter. This note summarizes the results of previous reports on the prediction and inversion of signatures from objects that radiate, ablate, and fragment during entry and uses them to produce models for the parameters of entering objects.

  11. Transverse Velocity Scaling in Au+Au Fragmentation

    OpenAIRE

    Lukasik, J.; Hudan, S.; Lavaud, F.; Turzo, K.; Auger, G.; Bacri, Ch.O.; Begemann-Blaich, M.L.; Bellaize, N.; Bittiger, R.; Bocage, F.; Borderie, B.; Buchet, P.; R. Bougault(LPCC); Bouriquet, B.; Charvet, J. L.

    2002-01-01

    Invariant transverse-velocity spectra of intermediate-mass fragments were measured with the 4-pi multi-detector system INDRA for collisions of Au on Au at incident energies between 40 and 150 MeV per nucleon. Their scaling properties as a function of incident energy and atomic number Z are used to distinguish and characterize the emissions in (i) peripheral collisions at the projectile and target rapidities, and in (ii) central and (iii) peripheral collisions near mid-rapidity. The importance...

  12. Interaction of three fission fragments and yields of various ternary fragments

    Science.gov (United States)

    Denisov, V. Yu.; Pilipenko, N. A.; Sedykh, I. Yu.

    2017-01-01

    The interaction potential energy of the three deformed fragments formed in fission of 252Cf is studied for various combinations of three-fragment fission. The lowest height of the potential energy ridge between three touching and separated deformed fragments is sought. The excitation energies of various three-deformed-fragment configurations, at the lowest barrier heights related to the yield of the corresponding configuration, are considered in detail. The most probable three-fragment fission configurations are discussed. The yields of various ternary fragments in fission of 250Cf agree well with available experimental data.

  13. Electronic Predetermination of Ethylene Fragmentation Dynamics

    Directory of Open Access Journals (Sweden)

    Xinhua Xie

    2014-04-01

    Full Text Available We experimentally investigate the dependence of the fragmentation behavior of the ethylene dication on the intensity and duration of the laser pulses that initiate the fragmentation dynamics by strong-field double ionization. Using coincidence momentum imaging for the detection of ionic fragments, we disentangle the different contributions of ionization from lower-valence orbitals and field-driven excitation dynamics to the population of certain dissociative excited ionic states that are connected to one of several possible fragmentation pathways towards a given set of fragment ions. We find that the excitation probability to a particular excited state and therewith the outcome of the fragmentation reaction strongly depend on the parameters of the laser pulse. This, in turn, opens up new possibilities for controlling the outcome of fragmentation reactions of polyatomic molecules in that it may allow one to selectively enhance or suppress individual fragmentation channels, which was not possible in previous attempts of controlling fragmentation processes of polyatomic molecules with strong laser fields.

  14. Molecular energies from an incremental fragmentation method

    Science.gov (United States)

    Meitei, Oinam Romesh; Heßelmann, Andreas

    2016-02-01

    The systematic molecular fragmentation method by Collins and Deev [J. Chem. Phys. 125, 104104 (2006)] has been used to calculate total energies and relative conformational energies for a number of small and extended molecular systems. In contrast to the original approach by Collins, we have tested the accuracy of the fragmentation method by utilising an incremental scheme in which the energies at the lowest level of the fragmentation are calculated on an accurate quantum chemistry level while lower-cost methods are used to correct the low-level energies through a high-level fragmentation. In this work, the fragment energies at the lowest level of fragmentation were calculated using the random-phase approximation (RPA) and two recently developed extensions to the RPA while the incremental corrections at higher levels of the fragmentation were calculated using standard density functional theory (DFT) methods. The complete incremental fragmentation method has been shown to reproduce the supermolecule results with a very good accuracy, almost independent on the molecular type, size, or type of decomposition. The fragmentation method has also been used in conjunction with the DFT-SAPT (symmetry-adapted perturbation theory) method which enables a breakdown of the total nonbonding energy contributions into individual interaction energy terms. Finally, the potential problems of the method connected with the use of capping hydrogen atoms are analysed and two possible solutions are supplied.

  15. Core stability exercise principles.

    Science.gov (United States)

    Akuthota, Venu; Ferreiro, Andrea; Moore, Tamara; Fredericson, Michael

    2008-02-01

    Core stability is essential for proper load balance within the spine, pelvis, and kinetic chain. The so-called core is the group of trunk muscles that surround the spine and abdominal viscera. Abdominal, gluteal, hip girdle, paraspinal, and other muscles work in concert to provide spinal stability. Core stability and its motor control have been shown to be imperative for initiation of functional limb movements, as needed in athletics. Sports medicine practitioners use core strengthening techniques to improve performance and prevent injury. Core strengthening, often called lumbar stabilization, also has been used as a therapeutic exercise treatment regimen for low back pain conditions. This article summarizes the anatomy of the core, the progression of core strengthening, the available evidence for its theoretical construct, and its efficacy in musculoskeletal conditions.

  16. Resolving the fragmentation of high line-mass filaments with ALMA: the integral shaped filament in Orion A

    Science.gov (United States)

    Kainulainen, J.; Stutz, A. M.; Stanke, T.; Abreu-Vicente, J.; Beuther, H.; Henning, T.; Johnston, K. G.; Megeath, S. T.

    2017-04-01

    We study the fragmentation of the nearest high line-mass filament, the integral shaped filament (ISF, line-mass 400 M⊙ pc-1) in the Orion A molecular cloud. We have observed a 1.6 pc long section of the ISF with the Atacama Large Millimetre/submillimeter Array (ALMA) at 3 mm continuum emission, at a resolution of 3″ (1200 AU). We identify from the region 43 dense cores with masses about a solar mass. 60% of the ALMA cores are protostellar and 40% are starless. The nearest neighbour separations of the cores do not show a preferred fragmentation scale; the frequency of short separations increases down to 1200 AU. We apply a two-point correlation analysis on the dense core separations and show that the ALMA cores are significantly grouped at separations below 17 000 AU and strongly grouped below 6000 AU. The protostellar and starless cores are grouped differently: only the starless cores group strongly below 6000 AU. In addition, the spatial distribution of the cores indicates periodic grouping of the cores into groups of 30 000 AU in size, separated by 50 000 AU. The groups coincide with dust column density peaks detected by Herschel. These results show hierarchical, two-mode fragmentation in which the maternal filament periodically fragments into groups of dense cores. Critically, our results indicate that the fragmentation models for lower line-mass filaments ( 16 M⊙ pc-1) fail to capture the observed properties of the ISF. We also find that the protostars identified with Spitzer and Herschel in the ISF are grouped at separations below 17 000 AU. In contrast, young stars with disks do not show significant grouping. This suggests that the grouping of dense cores is partially retained over the protostar lifetime, but not over the lifetime of stars with disks. This is in agreement with a scenario where protostars are ejected from the maternal filament by the slingshot mechanism, a model recently proposed for the ISF. The separation distributions of the dense

  17. HYDRATE CORE DRILLING TESTS

    Energy Technology Data Exchange (ETDEWEB)

    John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

    2002-11-01

    The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate

  18. Graded core/shell semiconductor nanorods and nanorod barcodes

    Science.gov (United States)

    Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

    2010-12-14

    Graded core/shell semiconductor nanorods and shaped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

  19. Decoupling habitat fragmentation from habitat loss: butterfly species mobility obscures fragmentation effects in a naturally fragmented landscape of lake islands.

    Science.gov (United States)

    MacDonald, Zachary G; Anderson, Iraleigh D; Acorn, John H; Nielsen, Scott E

    2018-01-01

    Since the publication of the theory of island biogeography, ecologists have postulated that fragmentation of continuous habitat presents a prominent threat to species diversity. However, negative fragmentation effects may be artifacts; the result of species diversity declining with habitat loss, and habitat loss correlating positively with degree of fragmentation. In this study, we used butterfly assemblages on islands of Lake of the Woods, Ontario, Canada to decouple habitat fragmentation from habitat loss and test two competing hypotheses: (1) the island effect hypothesis, which predicts that decreasing fragment size and increasing fragment isolation reduces species diversity beyond the effects of habitat loss, and (2) the habitat amount hypothesis, which negates fragmentation effects and predicts that only total habitat area determines the diversity of species persisting on fragmented landscapes. Using eight independent size classes of islands (ranging from 0.1 to 8.0 ha) that varied in number of islands while holding total area constant, species diversity comparisons, species accumulation curves, and species-area relationship extrapolations demonstrated that smaller insular habitats contained at least as many butterfly species as continuous habitat. However, when highly mobile species occurring on islands without their larval food plants were excluded from analyses, island effects on potentially reproducing species became apparent. Similarily, generalized linear models suggested that effects of island isolation and vascular plant richness on insular butterfly richness were confounded by species of high mobility. We conclude that inter-fragment movements of highly mobile species may obscure important fragmentation effects on potentially reproducing populations, questioning support for the habitat amount hypothesis.

  20. Detecting protein candidate fragments using a structural alphabet profile comparison approach.

    Science.gov (United States)

    Shen, Yimin; Picord, Géraldine; Guyon, Frédéric; Tuffery, Pierre

    2013-01-01

    Predicting accurate fragments from sequence has recently become a critical step for protein structure modeling, as protein fragment assembly techniques are presently among the most efficient approaches for de novo prediction. A key step in these approaches is, given the sequence of a protein to model, the identification of relevant fragments - candidate fragments - from a collection of the available 3D structures. These fragments can then be assembled to produce a model of the complete structure of the protein of interest. The search for candidate fragments is classically achieved by considering local sequence similarity using profile comparison, or threading approaches. In the present study, we introduce a new profile comparison approach that, instead of using amino acid profiles, is based on the use of predicted structural alphabet profiles, where structural alphabet profiles contain information related to the 3D local shapes associated with the sequences. We show that structural alphabet profile-profile comparison can be used efficiently to retrieve accurate structural fragments, and we introduce a fully new protocol for the detection of candidate fragments. It identifies fragments specific of each position of the sequence and of size varying between 6 and 27 amino-acids. We find it outperforms present state of the art approaches in terms (i) of the accuracy of the fragments identified, (ii) the rate of true positives identified, while having a high coverage score. We illustrate the relevance of the approach on complete target sets of the two previous Critical Assessment of Techniques for Protein Structure Prediction (CASP) rounds 9 and 10. A web server for the approach is freely available at http://bioserv.rpbs.univ-paris-diderot.fr/SAFrag.

  1. Detecting protein candidate fragments using a structural alphabet profile comparison approach.

    Directory of Open Access Journals (Sweden)

    Yimin Shen

    Full Text Available Predicting accurate fragments from sequence has recently become a critical step for protein structure modeling, as protein fragment assembly techniques are presently among the most efficient approaches for de novo prediction. A key step in these approaches is, given the sequence of a protein to model, the identification of relevant fragments - candidate fragments - from a collection of the available 3D structures. These fragments can then be assembled to produce a model of the complete structure of the protein of interest. The search for candidate fragments is classically achieved by considering local sequence similarity using profile comparison, or threading approaches. In the present study, we introduce a new profile comparison approach that, instead of using amino acid profiles, is based on the use of predicted structural alphabet profiles, where structural alphabet profiles contain information related to the 3D local shapes associated with the sequences. We show that structural alphabet profile-profile comparison can be used efficiently to retrieve accurate structural fragments, and we introduce a fully new protocol for the detection of candidate fragments. It identifies fragments specific of each position of the sequence and of size varying between 6 and 27 amino-acids. We find it outperforms present state of the art approaches in terms (i of the accuracy of the fragments identified, (ii the rate of true positives identified, while having a high coverage score. We illustrate the relevance of the approach on complete target sets of the two previous Critical Assessment of Techniques for Protein Structure Prediction (CASP rounds 9 and 10. A web server for the approach is freely available at http://bioserv.rpbs.univ-paris-diderot.fr/SAFrag.

  2. Edge-related loss of tree phylogenetic diversity in the severely fragmented Brazilian Atlantic forest.

    Directory of Open Access Journals (Sweden)

    Bráulio A Santos

    Full Text Available Deforestation and forest fragmentation are known major causes of nonrandom extinction, but there is no information about their impact on the phylogenetic diversity of the remaining species assemblages. Using a large vegetation dataset from an old hyper-fragmented landscape in the Brazilian Atlantic rainforest we assess whether the local extirpation of tree species and functional impoverishment of tree assemblages reduce the phylogenetic diversity of the remaining tree assemblages. We detected a significant loss of tree phylogenetic diversity in forest edges, but not in core areas of small (<80 ha forest fragments. This was attributed to a reduction of 11% in the average phylogenetic distance between any two randomly chosen individuals from forest edges; an increase of 17% in the average phylogenetic distance to closest non-conspecific relative for each individual in forest edges; and to the potential manifestation of late edge effects in the core areas of small forest remnants. We found no evidence supporting fragmentation-induced phylogenetic clustering or evenness. This could be explained by the low phylogenetic conservatism of key life-history traits corresponding to vulnerable species. Edge effects must be reduced to effectively protect tree phylogenetic diversity in the severely fragmented Brazilian Atlantic forest.

  3. High Fragmentation Steel Production Process

    Science.gov (United States)

    1981-08-01

    i 7’ t^ k ....■••■ ;....i’ST .PSI 1 I UJ 229 u HOUSTON INSTHUMENT c •*■? fr c ’•’■"’ ■Musi c ^^ m....l.Ji£.r* J ESAT #i i TE! ,—nr...8217.v.v-.f.:... ■_; i:.; ■ .;.-) N real "/&l!’i ■■■is- *SEA.«/ ■... I;I. 1 ,. , j .._ ■ I ■ ■ i ] . j X ’. i ■"■. i

  4. A dinuclear manganese(II) complex with the [Mn(2)(mu-O(2)CCH(3))(3)](+) core: synthesis, structure, characterization, electroinduced transformation, and catalase-like activity.

    Science.gov (United States)

    Romero, Isabel; Dubois, Lionel; Collomb, Marie-Noëlle; Deronzier, Alain; Latour, Jean-Marc; Pécaut, Jacques

    2002-04-08

    Reactions of Mn(II)(PF(6))(2) and Mn(II)(O(2)CCH(3))(2).4H(2)O with the tridentate facially capping ligand N,N-bis(2-pyridylmethyl)ethylamine (bpea) in ethanol solutions afforded the mononuclear [Mn(II)(bpea)](PF(6))(2) (1) and the new binuclear [Mn(2)(II,II)(mu-O(2)CCH(3))(3)(bpea)(2)](PF(6)) (2) manganese(II) compounds, respectively. Both 1 and 2 were characterized by X-ray crystallographic studies. Complex 1 crystallizes in the monoclinic system, space group P2(1)/n, with a = 11.9288(7) A, b = 22.5424(13) A, c =13.0773(7) A, alpha = 90 degrees, beta = 100.5780(10 degrees ), gamma = 90 degrees, and Z = 4. Crystals of complex 2 are orthorhombic, space group C222(1), with a = 12.5686(16) A, b = 14.4059(16) A, c = 22.515(3) A, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, and Z = 4. The three acetates bridge the two Mn(II) centers in a mu(1,3) syn-syn mode, with a Mn-Mn separation of 3.915 A. A detailed study of the electrochemical behavior of 1 and 2 in CH(3)CN medium has been made. Successive controlled potential oxidations at 0.6 and 0.9 V vs Ag/Ag(+) for a 10 mM solution of 2 allowed the selective and nearly quantitative formation of [Mn(III)(2)(mu-O)(mu-O(2)CCH(3))(2)(bpea)(2)](2+) (3) and [Mn(IV)(2)(mu-O)(2)(mu-O(2)CCH(3))(bpea)(2)](3+) (4), respectively. These results have shown that each substitution of an acetate group by an oxo group is induced by a two-electron oxidation of the corresponding dimanganese complexes. Similar transformations have been obtained if 2 is formed in situ either by direct mixing of Mn(2+) cations, bpea ligand, and CH(3)COO(-) anions with a 1:1:3 stoichiometry or by mixing of 1 and CH(3)COO(-) with a 1:1.5 stoichiometry. Associated electrochemical back-transformations were investigated. 2, 3, and the dimanganese [Mn(III)Mn(IV)(mu-O)(2)(mu-O(2)CCH(3))(bpea)(2)](2+) analogue (5) were also studied for their ability to disproportionate hydrogen peroxide. 2 is far more active compared to 3 and 5. The EPR monitoring of the

  5. FRAGMENTATION OF CONTINENTAL UNITES STATES FORESTS

    Science.gov (United States)

    We report a multiple-scale analysis of forest fragmentation based on 30-m land-cover maps for the conterminous United States. Each 0.09-ha unit of forest was classified according to fragmentation indices measured within the surrounding landscape, for five landscape sizes from 2....

  6. Generalized Fragmentation Functions for Fractal Jet Observables

    NARCIS (Netherlands)

    Elder, B.T.; Procura, M.; Thaler, J.; Waalewijn, W.J.; Zhou, K.

    We introduce a broad class of fractal jet observables that recursively probe the collective properties of hadrons produced in jet fragmentation. To describe these collinear-unsafe observables, we generalize the formalism of fragmentation functions, which are important objects in QCD for calculating

  7. INTERMITTENCY, A TEST FOR STRING FRAGMENTATION PROCESSES

    NARCIS (Netherlands)

    SCHOLTEN, O

    The Artru-Mennessier and the string fragmentation procedure as implemented in the code VENUS have been compared. The two fragmentation prescriptions predict a similar rapidity spectrum including its energy dependence and event multiplicities, but give rise to very different intermittency results.

  8. Fragmentation of eastern United States forest types

    Science.gov (United States)

    Kurt H. Riitters; John W. Coulston

    2013-01-01

    Fragmentation is a continuing threat to the sustainability of forests in the Eastern United States, where land use changes supporting a growing human population are the primary driver of forest fragmentation (Stein and others 2009). While once mostly forested, approximately 40 percent of the original forest area has been converted to other land uses, and most of the...

  9. Pollen and gene flow in fragmented habitats

    NARCIS (Netherlands)

    Kwak, Manja M.; Velterop, Odilia; van Andel, Jelte

    . Habitat fragmentation affects both plants and pollinators. Habitat fragmentation leads to changes in species richness, population number and size, density, and shape, thus to changes in the spatial arrangement of flowers. These changes influence the amount of food for flower-visiting insects and

  10. Analysis of core degradation and relocation phenomena and scenarios in a Nordic-type BWR

    Energy Technology Data Exchange (ETDEWEB)

    Galushin, Sergey, E-mail: galushin@kth.se; Kudinov, Pavel, E-mail: pkudinov@kth.se

    2016-12-15

    Highlights: • A data base of the debris properties in lower plenum generated using MELCOR code. • The timing of safety systems has significant effect on the relocated debris properties. • Loose coupling between core relocation and vessel failure analyses was established. - Abstract: Severe Accident Management (SAM) in Nordic Boiling Water Reactors (BWR) employs ex-vessel cooling of core melt debris. The melt is released from the failed vessel and poured into a deep pool of water located under the reactor. The melt is expected to fragment, quench, and form a debris bed, coolable by a natural circulation and evaporation of water. Success of the strategy is contingent upon melt release conditions from the vessel and melt-coolant interaction that determine (i) properties of the debris bed and its coolability (ii) potential for energetic melt-coolant interactions (steam explosions). Risk Oriented Accident Analysis Methodology (ROAAM+) framework is currently under development for quantification of the risks associated with formation of non-coolable debris bed and occurrence of steam explosions, both presenting a credible threats to containment integrity. The ROAAM+ framework consist of loosely coupled models that describe each stage of the accident progression. Core relocation analysis framework provides initial conditions for melt vessel interaction, vessel failure and melt release frameworks. The properties of relocated debris and melt release conditions, including in-vessel and ex-vessel pressure, lower drywell pool depth and temperature, are sensitive to the accident scenarios and timing of safety systems recovery and operator actions. This paper illustrates a methodological approach and relevant data for establishing a connection between core relocation and vessel failure analysis in ROAAM+ approach. MELCOR code is used for analysis of core degradation and relocation phenomena. Properties of relocated debris are obtained as functions of the accident scenario

  11. Long-term effects of fragmentation and fragment properties on bird species richness in Hawaiian forests

    Science.gov (United States)

    David J. Flaspohler; Christian P. Giardina; Gregory P. Asner; Patrick Hart; Jonathan Price; Cassie Ka’apu Lyons; Xeronimo. Castaneda

    2010-01-01

    Forest fragmentation is a common disturbance affecting biological diversity, yet the impacts of fragmentation on many forest processes remain poorly understood. Forest restoration is likely to be more successful when it proceeds with an understanding of how native and exotic vertebrates utilize forest patches of different size. We used a system of forest fragments...

  12. Simulation analysis of effects of single fragment size on air-blast wave and fragment propagation

    Directory of Open Access Journals (Sweden)

    ZHENG Hongwei

    2017-12-01

    Full Text Available [Objectives] This paper involves the propagation and attenuation of the velocity and energy of air-blast waves and high-velocity fragments while taking their combined effects into account.[Methods] With ANSYS/LS-DYNA software, a simulation model of a columnar TNT air blast is built with prefabricated fragments affixed to its end. When the total quality of fragments is constant, the effects of a single fragment's size on the propagation of the air-blast wave and fragments are studied by changing the size of the single fragment.[Results] The results show that fragments greatly reduce the intensity and velocity of a shockwave, and block the air-blast waves behind them. When the total quality of the fragments remains constant, the effects of single fragment size on blast shockwave propagation characteristics show little difference. The smaller the single fragment, the more kinetic energy the fragments will have and the faster that energy will dissipate.[Conclusions] As a result, more attention should be paid to the combined effects of air-blast waves and high-velocity fragments. Such research can provide reference points for the deeper study of blast loads and their interaction.

  13. Shell instability of a collapsing dense core

    Science.gov (United States)

    Ntormousi, Evangelia; Hennebelle, Patrick

    2015-02-01

    Aims: Understanding the formation of binary and multiple stellar systems largely comes down to studying the circumstances under which a condensing core fragments (or not) during the first stages of the collapse. However, both the probability of fragmentation and the number of fragments seem to be determined to a large degree by the initial conditions. In this work we explore this dependence by studying the fate of the linear perturbations of a homogeneous gas sphere, both analytically and numerically. Methods: In particular, we investigate the stability of the well-known homologous solution that describes the collapse of a uniform spherical cloud. One problem that arises in such treatments is the mathematical singularity in the perturbation equations, which corresponds to the location of the sonic point of the flow. This difficulty is surpassed here by explicitly introducing a weak shock next to the sonic point as a natural way of connecting the subsonic to the supersonic regimes. In parallel, we perform adaptive mesh refinement (AMR) numerical simulations of the linear stages of the collapse and compare the growth rates obtained by each method. Results: With this combination of analytical and numerical tools, we explore the behavior of both axisymmetric and non-axisymmetric perturbations. The numerical experiments provide the linear growth rates as a function of the core's initial virial parameter and as a function of the azimuthal wave number of the perturbation. The overlapping regime of the numerical experiments and the analytical predictions is the situation of a cold and large cloud, and in this regime the analytically calculated growth rates agree very well with the ones obtained from the simulations. Conclusions: The use of a weak shock as part of the perturbation allows us to find physically acceptable solutions to the equations for a continuous range of growth rates. The numerical simulations agree very well with the analytical prediction for the most

  14. EARLIEST STAGES OF PROTOCLUSTER FORMATION: SUBSTRUCTURE AND KINEMATICS OF STARLESS CORES IN ORION

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Katherine; Looney, Leslie W. [Department of Astronomy, University of Illinois, Urbana, IL 61801 (United States); Schnee, Scott [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Li Zhiyun [Astronomy Department, University of Virginia, Charlottesville, VA 22904 (United States)

    2013-08-01

    We study the structure and kinematics of nine 0.1 pc scale cores in Orion with the IRAM 30 m telescope and at higher resolution eight of the cores with CARMA, using CS(2-1) as the main tracer. The single-dish moment zero maps of the starless cores show single structures with central column densities ranging from 7 to 42 Multiplication-Sign 10{sup 23} cm{sup -2} and LTE masses from 20 M{sub Sun} to 154 M{sub Sun }. However, at the higher CARMA resolution (5''), all of the cores except one fragment into 3-5 components. The number of fragments is small compared to that found in some turbulent fragmentation models, although inclusion of magnetic fields may reduce the predicted fragment number and improve the model agreement. This result demonstrates that fragmentation from parsec-scale molecular clouds to sub-parsec cores continues to take place inside the starless cores. The starless cores and their fragments are embedded in larger filamentary structures, which likely played a role in the core formation and fragmentation. Most cores show clear velocity gradients, with magnitudes ranging from 1.7 to 14.3 km s{sup -1} pc{sup -1}. We modeled one of them in detail, and found that its spectra are best explained by a converging flow along a filament toward the core center; the gradients in other cores may be modeled similarly. We infer a mass inflow rate of {approx}2 Multiplication-Sign 10{sup -3} M{sub Sun} yr{sup -1}, which is in principle high enough to overcome radiation pressure and allow for massive star formation. However, the core contains multiple fragments, and it is unclear whether the rapid inflow would feed the growth of primarily a single massive star or a cluster of lower mass objects. We conclude that fast, supersonic converging flow along filaments play an important role in massive star and cluster formation.

  15. Description of gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

    Science.gov (United States)

    Woodrow, Donald L.; John L. Chin,; Wong, Florence L.; Fregoso, Theresa; Jaffe, Bruce E.

    2017-06-27

    Seventy-two gravity cores were collected by the U.S. Geological Survey in 1990, 1991, and 2000 from San Pablo Bay and Carquinez Strait, California. The gravity cores collected within San Pablo Bay contain bioturbated laminated silts and sandy clays, whole and broken bivalve shells (mostly mussels), fossil tube structures, and fine-grained plant or wood fragments. Gravity cores from the channel wall of Carquinez Strait east of San Pablo Bay consist of sand and clay layers, whole and broken bivalve shells (less than in San Pablo Bay), trace fossil tubes, and minute fragments of plant material.

  16. Effects of habitat fragmentation on wild mammal infection by Trypanosoma cruzi.

    Science.gov (United States)

    Vaz, V C; D'Andrea, P S; Jansen, A M

    2007-11-01

    Expansion of human activities frequently results in habitat fragmentation, a phenomenon that has been widely recognized in the last decades as one of the major threats to world's biodiversity. The transformation of a continuous forest into a fragmented area results in a hyper-dynamic landscape with unpredictable consequences to overall ecosystem health. The effect of the fragmentation process on Trypanosoma cruzi infection among small wild mammals was studied in an Atlantic Rain Forest landscape. Comparing continous forest to fragmented habitat, marsupials were less abundant than rodents in the continuous landscape. An overall decrease in small wild mammal richness was observed in the smaller fragments. An anti-T. cruzi seroprevalence of 18% (82/440) was deteced by immunofluorescence assay. Moreover, this seroprevalence was higher in the fragmented habitat than in the continuous forest. According to the collected data, 3 main factors seem to modulate infection by T. cruzi in small wild mammals: (i) habitat fragmentation; (ii) biodiversity loss; (iii) increase of marsupial abundance in mammal communities. Furthermore, an extremely mild controlled infection by T. cruzi was detected since no patent parasitaemia could be detected in fresh blood samples, and no parasites were isolated by haemoculture.

  17. Diquark Fragmentation Contribution in Λ b Production

    Science.gov (United States)

    Osati, T.; Movlanaei, M.

    2017-05-01

    In the framework of the quark-diquark model of baryons, Λ b can be considered as b constituent quark an ud constituent diquark. In this study, we investigate the effect ud scalar diquark fragmentation into Λ b , therefor we calculate frgmentation functions of b quark and ud diquark into Λ b baryon through the use of perturbative QCD. In the next stage, throuth the use of the obtained fragmentation functions, we calculate the total fragmentation probabilities and average fragmentation parameters for b→Λ b and u d→Λ b . Finally, the inclusive cross section of Λ b baryon in electron-positron annihilation in ALEPH experiment is calculated with regard to ud diquark fragmentation contribution.

  18. The Restriction Fragment Map of Rat-Liver Mitochondrial DNA : A Reconsideration

    NARCIS (Netherlands)

    Pepe, G.; Bakker, H.; Holtrop, M.; Bollen, J.E.; Bruggen, E.F.J. van; Cantatore, P.; Terpstra, P.; Saccone, C.

    1977-01-01

    1. Rat-liver mitochondrial DNA (mtDNA) contains at least 8 cleavage sites for the restriction endonuclease Eco RI, 6 for the restriction endonuclease Hind III, 2 for the restriction endonuclease Bam HI and 11 for the restriction endonuclease Hap II. 2. The physical map of the restriction fragments

  19. Sediment Core Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation and expertise for physical and geoacoustic characterization of marine sediments.DESCRIPTION: The multisensor core logger measures...

  20. Adaptive core simulation

    Science.gov (United States)

    Abdel-Khalik, Hany Samy

    The work presented in this thesis is a continuation of a master's thesis research project conducted by the author to gain insight into the applicability of inverse methods to developing adaptive simulation capabilities for core physics problems. Use of adaptive simulation is intended to improve the fidelity and robustness of important core attributes predictions such as core power distribution, thermal margins and core reactivity. Adaptive simulation utilizes a selected set of past and current reactor measurements of reactor observables, i.e. in-core instrumentations readings, to adapt the simulation in a meaningful way. A meaningful adaption will result in high fidelity and robust adapted core simulators models. To perform adaption, we propose an inverse theory approach in which the multitudes of input data to core simulators, i.e. reactor physics and thermal-hydraulic data, are to be adjusted to improve agreement with measured observables while keeping core simulators models unadapted. At a first glance, devising such adaption for typical core simulators models would render the approach impractical. This follows, since core simulators are based on very demanding computational models, i.e. based on complex physics models with millions of input data and output observables. This would spawn not only several prohibitive challenges but also numerous disparaging concerns. The challenges include the computational burdens of the sensitivity-type calculations required to construct Jacobian operators for the core simulators models. Also, the computational burdens of the uncertainty-type calculations required to estimate the uncertainty information of core simulators input data presents a demanding challenge. The concerns however are mainly related to the reliability of the adjusted input data. We demonstrate that the power of our proposed approach is mainly driven by taking advantage of this unfavorable situation. Our contribution begins with the realization that to obtain

  1. Controlled production of sub-millimeter liquid core hydrogel capsules for parallelized 3D cell culture.

    Science.gov (United States)

    Doméjean, Hugo; de la Motte Saint Pierre, Mathieu; Funfak, Anette; Atrux-Tallau, Nicolas; Alessandri, Kevin; Nassoy, Pierre; Bibette, Jérôme; Bremond, Nicolas

    2016-12-20

    Liquid core capsules having a hydrogel membrane are becoming a versatile tool for three-dimensional culture of micro-organisms and mammalian cells. Making sub-millimeter capsules at a high rate, via the breakup of a compound jet in air, opens the way to high-throughput screening applications. However, control of the capsule size monodispersity, especially required for quantitative bioassays, was still lacking. Here, we report how the understanding of the underlying hydrodynamic instabilities that occur during the process can lead to calibrated core-shell bioreactors. The requirements are: i) damping the shear layer instability that develops inside the injector arising from the co-annular flow configuration of liquid phases having contrasting viscoelastic properties; ii) controlling the capillary instability of the compound jet by superposing a harmonic perturbation onto the shell flow; iii) avoiding coalescence of drops during jet fragmentation as well as during drop flight towards the gelling bath; iv) ensuring proper engulfment of the compound drops into the gelling bath for building a closed hydrogel shell. We end up with the creation of numerous identical compartments in which cells are able to form multicellular aggregates, namely spheroids. In addition, we implement an intermediate composite hydrogel layer, composed of alginate and collagen, allowing cell adhesion and thus the formation of epithelia or monolayers of cells.

  2. Analysis of the chondroitin sulfate proteoglycan core protein (CSPGCP) gene in achondroplasia and pseudoachondroplasia.

    Science.gov (United States)

    Finkelstein, J E; Doege, K; Yamada, Y; Pyeritz, R E; Graham, J M; Moeschler, J B; Pauli, R M; Hecht, J T; Francomano, C A

    1991-01-01

    Achondroplasia and pseudoachondroplasia are autosomal dominant skeletal dysplasias resulting in short-limbed dwarfism. Histologic and ultrastructural studies of the cartilage in pseudoachondroplasia and in homozygous achondroplasia have suggested a structural abnormality in chondroitin sulfate proteoglycan (CSPG), a major structural protein in the extra-cellular matrix. The gene encoding CSPG core protein (CSPGCP) is thus a logical "candidate gene" for analysis in these conditions. cDNA probes encoding CSPGCP were used to identify restriction fragment length polymorphisms (RFLPs) in DNA from a panel of control individuals. No gross alterations at the CSPGCP locus were noted in DNA from 37 individuals with achondroplasia and 5 individuals with pseudoachondroplasia. In addition, allelic frequencies of the RFLPs were not significantly different among controls and patients with either condition. In one three-generation family with achondroplasia, close linkage of the CSPGCP locus and the skeletal dysplasia was excluded using a Bgl II polymorphism. Similarly, in a three-generation family with pseudoachondroplasia, the CSPGCP gene was not tightly linked to the disease phenotype. These results indicate that mutations at the chondroitin sulfate proteoglycan core protein locus do not cause achondroplasia or pseudoachondroplasia in these families. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:1670752

  3. Core physics experiment of 100% MOX core: MISTRAL

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T.; Matsu-ura, H.; Ueji, M. [Nuclear Power Engineering Corp., Tokyo (Japan); Cathalau, S.; Cabrillat, J.C.; Chauvin, J.P.; Finck, P.J.; Fougeras, P.; Flamenbaum, G.

    1997-12-31

    An extensive experimental program, MISTRAL, was undertaken in the EOLE critical facility of CEA in order to measure the main core physics parameters of 100% MOX loaded cores of light water reactors. The experimental program comprises four core configurations with high moderator to fuel ratio, including three homogeneous cores and one PWR type mock-up core. This paper presents the experiment of the first homogeneous core of uranium fuel as a reference core of the MOX cores and a part of the experiment of the second core, a 100% MOX homogeneous core. (author)

  4. Exact Solutions of Fragmentation Equations with General Fragmentation Rates and Separable Particles Distribution Kernels

    Directory of Open Access Journals (Sweden)

    S. C. Oukouomi Noutchie

    2014-01-01

    Full Text Available We make use of Laplace transform techniques and the method of characteristics to solve fragmentation equations explicitly. Our result is a breakthrough in the analysis of pure fragmentation equations as this is the first instance where an exact solution is provided for the fragmentation evolution equation with general fragmentation rates. This paper is the key for resolving most of the open problems in fragmentation theory including “shattering” and the sudden appearance of infinitely many particles in some systems with initial finite particles number.

  5. Can Psychiatric Rehabilitation Be Core to CORE?

    Science.gov (United States)

    Olney, Marjorie F.; Gill, Kenneth J.

    2016-01-01

    Purpose: In this article, we seek to determine whether psychiatric rehabilitation principles and practices have been more fully incorporated into the Council on Rehabilitation Education (CORE) standards, the extent to which they are covered in four rehabilitation counseling "foundations" textbooks, and how they are reflected in the…

  6. Gene duplication and fragmentation in the zebra finch major histocompatibility complex

    Directory of Open Access Journals (Sweden)

    Burt David W

    2010-04-01

    Full Text Available Abstract Background Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. Results The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. Conclusion The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving

  7. Geochemical assessment of metal pollution and ecotoxicology in sediment cores along Karachi Coast, Pakistan.

    Science.gov (United States)

    Mashiatullah, Azhar; Chaudhary, Muhammad Zaman; Ahmad, Nasir; Ahmad, Nisar; Javed, Tariq; Ghaffar, Abdul

    2015-05-01

    This paper is an attempt to compare the pollution status in two sediment cores, one from a polluted site (Ghizri Creek) and another from a relatively unpolluted site (Sandspit). Sediment cores (45 cm in length) from coastal locations were characterized in terms of grain size, sediment composition, pH, organic matter, calcium carbonate, and metal element contents. Metal elements, including Al, Ca, Cr, Co Cu, Fe, K, Mg, Mn, Ni, Pb, V, Ti, and Zn, were determined using PIXE. Grain size analysis and sediment composition demonstrated a sandy nature of both cores. Acidic trend in sediment core I was predominant from bottom to top, whereas neutral pH was observed throughout core II. TOC values varied in the range of 1.23-2.68 and 1.14-2.60% in core I and core II, respectively; however, there was an increasing trend in TOC level from bottom to top. The values of enrichment factor for Zn, Cu, Co, Ni, Pb, and Cr were slightly higher in core I than core II. The average geo-accumulation index values for core I and core II showed that sediments were moderately Co- and Pb-polluted but not polluted with Mg, Al, Ca, K, Cr, Cu, Fe, Mn, Ni, Ti, V, and Zn. The degree of contamination was however considerably higher in core I relative to core II. The pollution load index values, although showing an increasing trend from bottom to top in both cores, overall rendered the marine sediment pollution free. The metal toxicology results demonstrated that heavy metal pollution, except Cr, may pose low to moderate risk to marine biota. The sum of toxic unit values however indicated that sediment core I was relatively more polluted than that of core II.

  8. Improved chemical shift based fragment selection for CS-Rosetta using Rosetta3 fragment picker

    Energy Technology Data Exchange (ETDEWEB)

    Vernon, Robert [Hospital for Sick Children, Program in Molecular Structure and Function (Canada); Shen, Yang [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Baker, David [University of Washington, Department of Biochemistry (United States); Lange, Oliver F., E-mail: oliver.lange@tum.de [Technische Universitaet Muenchen, Department Chemie, Biomolecular NMR and Munich Center for Integrated Protein Science (Germany)

    2013-10-15

    A new fragment picker has been developed for CS-Rosetta that combines beneficial features of the original fragment picker, MFR, used with CS-Rosetta, and the fragment picker, NNMake, that was used for purely sequence based fragment selection in the context of ROSETTA de-novo structure prediction. Additionally, the new fragment picker has reduced sensitivity to outliers and other difficult to match data points rendering the protocol more robust and less likely to introduce bias towards wrong conformations in cases where data is bad, missing or inconclusive. The fragment picker protocol gives significant improvements on 6 of 23 CS-Rosetta targets. An independent benchmark on 39 protein targets, whose NMR data sets were published only after protocol optimization had been finished, also show significantly improved performance for the new fragment picker (van der Schot et al. in J Biomol NMR, 2013)

  9. Dual Fragment Impact of PBX Charges

    Science.gov (United States)

    Haskins, Peter; Briggs, Richard; Leeming, David; White, Nathan; Cheese, Philip; DE&S MoD UK Team; Ordnance Test Solutions Ltd Team

    2017-06-01

    Fragment impact can pose a significant hazard to many systems containing explosives or propellants. Testing for this threat is most commonly carried out using a single fragment. However, it can be argued that an initial fragment strike (or strikes) could sensitise the energetic material to subsequent impacts, which may then lead to a more violent reaction than would have been predicted based upon single fragment studies. To explore this potential hazard we have developed the capability to launch 2 fragments from the same gun at a range of velocities, and achieve impacts on an acceptor charge with good control over the spatial and temporal separation of the strikes. In this paper we will describe in detail the experimental techniques we have used, both to achieve the dual fragment launch and observe the acceptor charge response. In addition, we will describe the results obtained against PBX filled explosive targets; discuss the mechanisms controlling the target response and their significance for vulnerability assessment. Results of these tests have clearly indicated the potential for detonation upon the second strike, at velocities well below those needed for shock initiation by a single fragment.

  10. Fungal fragments in moldy houses: A field study in homes in New Orleans and Southern Ohio

    Science.gov (United States)

    Reponen, Tiina; Seo, Sung-Chul; Grimsley, Faye; Lee, Taekhee; Crawford, Carlos; Grinshpun, Sergey A.

    Smaller-sized fungal fragments (mold-related health effects. Previous laboratory-based studies have shown that the number concentration of fungal fragments can be up to 500 times higher than that of fungal spores, but this has not yet been confirmed in a field study due to lack of suitable methodology. We have recently developed a field-compatible method for the sampling and analysis of airborne fungal fragments. The new methodology was utilized for characterizing fungal fragment exposures in mold-contaminated homes selected in New Orleans, Louisiana and Southern Ohio. Airborne fungal particles were separated into three distinct size fractions: (i) >2.25 μm (spores), (ii) 1.05-2.25 μm (mixture), and (iii) <1.0 μm (submicrometer-sized fragments). Samples were collected in five homes in summer and winter and analyzed for (1→3)- β- D-glucan. The total (1→3)- β- D-glucan varied from 0.2 to 16.0 ng m -3. The ratio of (1→3)- β- D-glucan mass in fragment size fraction to that in spore size fraction ( F/ S) varied from 0.011 to 2.163. The mass ratio was higher in winter (average=1.017) than in summer (0.227) coinciding with a lower relative humidity in the winter. Assuming a mass-based F/ S-ratio=1 and the spore size=3 μm, the corresponding number-based F/ S-ratio (fragment number/spore number) would be 10 3 and 10 6, for the fragment sizes of 0.3 and 0.03 μm, respectively. These results indicate that the actual (field) contribution of fungal fragments to the overall exposure may be very high, even much greater than that estimated in our earlier laboratory-based studies.

  11. HETC-3STEP included fragmentation process

    Energy Technology Data Exchange (ETDEWEB)

    Shigyo, Nobuhiro; Iga, Kiminori; Ishibashi, Kenji [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1997-03-01

    High Energy Transport Code (HETC) based on the cascade-evaporation model is modified to calculate the fragmentation cross section. For the cascade process, nucleon-nucleon cross sections are used for collision computation; effective in-medium-corrected cross sections are adopted instead of the original free-nucleon collision. The exciton model is adopted for improvement of backward nucleon-emission cross section for low-energy nucleon-incident events. The fragmentation reaction is incorporated into the original HETC as a subroutine set by the use of the systematics of the reaction. The modified HETC (HETC-3STEP/FRG) reproduces experimental fragment yields to a reasonable degree. (author)

  12. Heart Rate Fragmentation: A Symbolic Dynamical Approach

    Directory of Open Access Journals (Sweden)

    Madalena D. Costa

    2017-11-01

    Full Text Available Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability.Objective: The objectives of this study were to: (1 introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2 evaluate how the distribution of the different dynamical patterns (“words” varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD; and (3 quantify the differences in the fragmentation patterns between the two sample populations.Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW.Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed “soft” inflection points. In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to

  13. Heart Rate Fragmentation: A Symbolic Dynamical Approach.

    Science.gov (United States)

    Costa, Madalena D; Davis, Roger B; Goldberger, Ary L

    2017-01-01

    Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability. Objective: The objectives of this study were to: (1) introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2) evaluate how the distribution of the different dynamical patterns ("words") varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD); and (3) quantify the differences in the fragmentation patterns between the two sample populations. Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words) with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW). Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed "soft" inflection points). In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to deceleration and vice

  14. Composite Overwrap Fragmentation Observations, Concerns, and Recommendations

    Science.gov (United States)

    Bangham, Mike; Hovater, Mary

    2017-01-01

    A series of test activities has raised some concerns about the generation of orbital debris caused by failures of composite overwrapped pressure vessels (COPVs). These tests have indicated that a large number of composite fragments can be produced by either pressure burst failures or by high-speed impacts. A review of prior high-speed tests with COPV indicates that other tests have produced large numbers of composite fragments. As was the case with the test referenced here, the tests tended to produce a large number of small composite fragments with relatively low velocities induced by the impact and or gas expansion.

  15. Bone fragments a body can make

    Energy Technology Data Exchange (ETDEWEB)

    Stout, S.D.; Ross, L.M. Jr. (Department of Anthropology, University of Missouri, Columbia (USA))

    1991-05-01

    Data obtained from various analytical techniques applied to a number of small bone fragments recovered from a crime scene were used to provide evidence for the occurrence of a fatality. Microscopic and histomorphometric analyses confirmed that the fragments were from a human skull. X-ray microanalysis of darkened areas on the bone fragments revealed a chemical signature that matched the chemical signature of a shotgun pellet recovered at the scene of the crime. The above findings supported the deoxyribonucleic acid (DNA) fingerprint evidence which, along with other evidence, was used to convict a man for the murder of his wife, even though her body was never recovered.

  16. The late effect of grenade fragments.

    Science.gov (United States)

    Symonds, R P; Mackay, C; Morley, P

    1985-06-01

    Following the explosion of a grenade or shell, the victim may be peppered with literally hundreds of pieces of metal. Troublesome fragments which perforate a major viscus may be removed but others are often left behind, as it is felt (usually correctly) that these fragments will cause no harm. We describe a case in which a grenade fragment received 16 years previously pierced the large bowel. A psoas abscess developed which was located by ultrasound. Pus was aspirated under ultrasound control and the lesion was successfully treated by antibiotics.

  17. Extraction of 16th Century Calender Fragments

    DEFF Research Database (Denmark)

    Holck, Jakob Povl; Etheridge, Christian

    at the Cultural Heritage & Archaeometric Research Team, SDU. Upon finding medieval manuscript fragments in the university library’s special collections, scholars at the Centre for Medieval Literature are consulted. In most cases, digital pictures of the finds will circulate in the international community...... of medieval scholars. Thousands of 16th and 17th Century books are stored in the University Library of Southern Denmark. One out of five of these books is expected to contain medieval manuscript fragments or fragments of rare prints, e.g. incunabula....

  18. Dark Matter Cores in the Fornax and Sculptor Dwarf Galaxies

    DEFF Research Database (Denmark)

    C. Amorisco, Nicola; Zavala Franco, Jesus; J. L. de Boer, Thomas

    2014-01-01

    We combine the detailed Star Formation Histories of the Fornax and Sculptor dwarf Spheroidals with the mass assembly history of their dark matter halo progenitors to estimate if the energy deposited by Supernova type II (SNeII) is sufficient to create a substantial dark matter core. Assuming...... the efficiency of energy injection of the SNeII into dark matter particles is \\epsilon=0.05, we find that a single early episode, z...

  19. Lunar Core and Tides

    Science.gov (United States)

    Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

    2004-01-01

    Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.

  20. Enhancement of the southward return flow of the Atlantic Meridional Overturning Circulation by data assimilation and its influence in an assimilative ocean simulation forced by CORE-II atmospheric forcing

    Science.gov (United States)

    Fujii, Yosuke; Tsujino, Hiroyuki; Toyoda, Takahiro; Nakano, Hideyuki

    2017-08-01

    This paper examines the difference in the Atlantic Meridional Overturning Circulation (AMOC) mean state between free and assimilative simulations of a common ocean model using a common interannual atmospheric forcing. In the assimilative simulation, the reproduction of cold cores in the Nordic Seas, which is absent in the free simulation, enhances the overflow to the North Atlantic and improves AMOC with enhanced transport of the deeper part of the southward return flow. This improvement also induces an enhanced supply of North Atlantic Deep Water (NADW) and causes better representation of the Atlantic deep layer despite the fact that correction by the data assimilation is applied only to temperature and salinity above a depth of 1750 m. It also affects Circumpolar Deep Water in the Southern Ocean. Although the earliest influence of the improvement propagated by coastal waves reaches the Southern Ocean in 10-15 years, substantial influence associated with the arrival of the renewed NADW propagates across the Atlantic Basin in several decades. Although the result demonstrates that data assimilation is able to improve the deep ocean state even if there is no data there, it also indicates that long-term integration is required to reproduce variability in the deep ocean originating from variations in the upper ocean. This study thus provides insights on the reliability of AMOC and the ocean state in the Atlantic deep layer reproduced by data assimilation systems.

  1. The t-core of an s-core

    OpenAIRE

    Fayers, Matthew

    2011-01-01

    We consider the $t$-core of an $s$-core partition, when $s$ and $t$ are coprime positive integers. Olsson has shown that the $t$-core of an $s$-core is again an $s$-core, and we examine certain actions of the affine symmetric group on $s$-cores which preserve the $t$-core of an $s$-core. Along the way, we give a new proof of Olsson's result. We also give a new proof of a result of Vandehey, showing that there is a simultaneous $s$- and $t$-core which contains all others.

  2. Destabilization and intracranial fragmentation of a full metal jacket bullet.

    Science.gov (United States)

    Farrugia, A; Raul, J S; Geraut, A; Tortel, M C; Ludes, B

    2009-10-01

    We report a case with an atypical entrance wound as a result of a destabilized full metal jacket bullet penetration. The destabilized bullet by an impact with the dorsal hand experiences a yawing to tumbling motion in flight. The large angle of yaw induces a larger presenting profile upon impact that contributes, associated to a rapid deceleration, to a greater mechanical force on the projectile structure and a fragmentation into core and jacket. Forensic pathologists have to be aware that the metal jacket bullet could tend to break up outside or inside the body particularly after a shooting through a target. This phenomenon induces atypical entrance wounds and atypical X-ray presentation. 2009 Elsevier Ltd and Faculty of Forensic and Legal Medicine.

  3. Dependence of Core and Extended Flux on Core Dominance ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Based on two extragalactic radio source samples, the core dominance parameter is calculated, and the correlations between the core/extended flux density and core dominance parameter are investigated. When the core dominance parameter is lower than unity, it is linearly correlated with the core flux ...

  4. Earth's inner core: Innermost inner core or hemispherical variations?

    NARCIS (Netherlands)

    Lythgoe, K. H.; Deuss, A.; Rudge, J. F.; Neufeld, J. A.

    2014-01-01

    The structure of Earth's deep inner core has important implications for core evolution, since it is thought to be related to the early stages of core formation. Previous studies have suggested that there exists an innermost inner core with distinct anisotropy relative to the rest of the inner core.

  5. Dependence of Core and Extended Flux on Core Dominance ...

    Indian Academy of Sciences (India)

    Abstract. Based on two extragalactic radio source samples, the core dominance parameter is calculated, and the correlations between the core/extended flux density and core dominance parameter are investi- gated. When the core dominance parameter is lower than unity, it is linearly correlated with the core flux density, ...

  6. Korrelasjon mellom core styrke, core stabilitet og utholdende styrke i core

    OpenAIRE

    Berg-Olsen, Andrea Marie; Fugelsøy, Eivor; Maurstad, Ann-Louise

    2010-01-01

    Formålet med studien var å se hvilke korrelasjon det er mellom core styrke, core stabilitet og utholdende styrke i core. Testingen bestod av tre hoveddeler hvor vi testet core styrke, core stabilitet og utholdende styrke i core. Innenfor core styrke og utholdende styrke i core ble tre ulike tester utført. Ved måling av core stabilitet ble det gjennomført kun en test. I core styrke ble isometrisk abdominal fleksjon, isometrisk rygg ekstensjon og isometrisk lateral fleksjon testet. Sit-ups p...

  7. Anthropogenic Fragmentation in the western United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — We evaluated the fragmentation of the western United States by anthropogenic features. The addition of roads, railroads, and power lines to wildlands, and the...

  8. The Fragmentation of the College Mathematics Curriculum

    Science.gov (United States)

    Singleton, Cynthia

    2008-01-01

    The purpose of this paper examines to what extent and asking reason the fragmentation of college mathematics have attained the present development in the course of looking at the history of mathematics education. (Contains 1 table.)

  9. The NJL Model for Quark Fragmentation Functions

    Energy Technology Data Exchange (ETDEWEB)

    T. Ito, W. Bentz, I. Cloet, A W Thomas, K. Yazaki

    2009-10-01

    A description of fragmentation functions which satisfy the momentum and isospin sum rules is presented in an effective quark theory. Concentrating on the pion fragmentation function, we first explain the reason why the elementary (lowest order) fragmentation process q → qπ is completely inadequate to describe the empirical data, although the “crossed” process π → qq describes the quark distribution functions in the pion reasonably well. Then, taking into account cascade-like processes in a modified jet-model approach, we show that the momentum and isospin sum rules can be satisfied naturally without introducing any ad-hoc parameters. We present numerical results for the Nambu-Jona-Lasinio model in the invariant mass regularization scheme, and compare the results with the empirical parametrizations. We argue that this NJL-jet model provides a very useful framework to calculate the fragmentation functions in an effective chiral quark theory.

  10. New Methodology for Simulating Fragmentation Munitions

    National Research Council Canada - National Science Library

    Gold, V

    2001-01-01

    This document on New Methodology for Simulating Fragmentation Munitions consists of the 17 presentation slides that were presented at the Proceedings of the 36th Annual Gun and Ammunition Symposium...

  11. Sustained Sleep Fragmentation Induces Sleep Homeostasis in Mice

    Science.gov (United States)

    Baud, Maxime O.; Magistretti, Pierre J.; Petit, Jean-Marie

    2015-01-01

    Study Objectives: Sleep fragmentation (SF) is an integral feature of sleep apnea and other prevalent sleep disorders. Although the effect of repetitive arousals on cognitive performance is well documented, the effects of long-term SF on electroencephalography (EEG) and molecular markers of sleep homeostasis remain poorly investigated. To address this question, we developed a mouse model of chronic SF and characterized its effect on EEG spectral frequencies and the expression of genes previously linked to sleep homeostasis including clock genes, heat shock proteins, and plasticity-related genes. Design: N/A. Setting: Animal sleep research laboratory. Participants : Sixty-six C57BL6/J adult mice. Interventions: Instrumental sleep disruption at a rate of 60/h during 14 days Measurements and Results: Locomotor activity and EEG were recorded during 14 days of SF followed by recovery for 2 days. Despite a dramatic number of arousals and decreased sleep bout duration, SF minimally reduced total quantity of sleep and did not significantly alter its circadian distribution. Spectral analysis during SF revealed a homeostatic drive for slow wave activity (SWA; 1–4 Hz) and other frequencies as well (4–40 Hz). Recordings during recovery revealed slow wave sleep consolidation and a transient rebound in SWA, and paradoxical sleep duration. The expression of selected genes was not induced following chronic SF. Conclusions: Chronic sleep fragmentation (SF) increased sleep pressure confirming that altered quality with preserved quantity triggers core sleep homeostasis mechanisms. However, it did not induce the expression of genes induced by sleep loss, suggesting that these molecular pathways are not sustainably activated in chronic diseases involving SF. Citation: Baud MO, Magistretti PJ, Petit JM. Sustained sleep fragmentation induces sleep homeostasis in mice. SLEEP 2015;38(4):567–579. PMID:25325477

  12. Fragmentation of Care in Ectopic Pregnancy.

    Science.gov (United States)

    Stulberg, Debra B; Dahlquist, Irma; Jarosch, Christina; Lindau, Stacy T

    2016-05-01

    Ectopic pregnancy is an important cause of maternal morbidity and mortality. Women who experience fragmented care may undergo unnecessary delays to diagnosis and treatment. Based on ectopic pregnancy cases observed in clinical practice that raised our concern about fragmentation of care, we designed an exploratory study to describe the number, characteristics, and outcomes of fragmented care among patients with ectopic pregnancy at one urban academic hospital. Chart review with descriptive statistics. Fragmented care was defined as a patient being evaluated at an outside facility for possible ectopic pregnancy and transferred, referred, or discharged before receiving care at the study institution. Of 191 women seen for possible or definite ectopic pregnancy during the study period, 42 (22 %) met the study definition of fragmented care. The study was under-powered to observe statistically significant differences across groups, but we found concerning, non-significant trends: patients with fragmented care were more likely to be Medicaid recipients (65.9 vs. 58.8 %) and to experience a complication (23.8 vs. 18.1 %) compared to those with non-fragmented care. Most patients (n = 37) received no identifiable treatment prior to transfer and arrived to the study hospital with no communication to the receiving hospital from the outside provider (n = 34). Nine patients (21 %) presented with ruptured ectopic pregnancies. The fragmentation we observed in our study may contribute to previously identified socio-economic disparities in ectopic pregnancy outcomes. If future research confirms these findings, health information exchanges and regional coordination of care may be important strategies for reducing maternal mortality.

  13. Studies of Shell Fragment Mass Distribution

    Science.gov (United States)

    1946-01-05

    E-i C) C 5a- 3 HljI 4----- oI ’H+ COC -4 E- I yh E0 O . ’-0 - - 38 Tho,:s2- data arm fairly consitEACnt ý,eith the ecec ption of Shot :,,42 forTPT hs...fragments. In addition, fragment retardation at the New Mexico range is significantly smaller because of the higher altitude. 0 Lo to C𔃻 00 t t fLd 4

  14. Observations of Titan IIIC Transtage Fragmentation Debris

    Science.gov (United States)

    Cowardin, Heather; Seitzer, P.; Abercromby, K.; Barker, E.; Buckalew, B.; Cardona, T.; Krisko, P.; Lederer, S.

    2013-01-01

    The fragmentation of a Titan IIIC Transtage (1968-081) on 21 February 1992 is one of only two known break-ups in or near geosynchronous orbit. The original rocket body and 24 pieces of debris are currently being tracked by the U. S. Space Surveillance Network (SSN). The rocket body (SSN# 3432) and several of the original fragments (SSN# 25000, 25001, 30000, and 33511) were observed in survey mode during 2004-2010 using the 0.6-m Michigan Orbital DEbris Survey Telescope (MODEST) in Chile using a broad R filter. This paper presents a size distribution for all calibrated magnitude data acquired on MODEST. Size distribution plots are also shown using historical models for small fragmentation debris (down to 10 cm) thought to be associated with the Titan Transtage break-up. In November 2010, visible broadband photometry (Johnson/Kron-Cousins BVRI) was acquired with the 0.9-m Small and Moderate Aperture Research Telescope System (SMARTS) at the Cerro Tololo Inter-American Observatory (CTIO) in Chile on several Titan fragments (SSN 25001, 33509, and 33510) and the parent rocket body (SSN 3432). Color index data are used to determine the fragment brightness distribution and how the data compares to spacecraft materials measured in the laboratory using similar photometric measurement techniques. In order to better characterize the break-up fragments, spectral measurements were acquired on three Titan fragments (one fragment observed over two different time periods) using the 6.5-m Magellan telescopes at Las Campanas Observatory in Chile. The telescopic spectra of SSN 25000 (May 2012 and January 2013), SSN 38690, and SSN 38699 are compared with laboratory acquired spectra of materials (e.g., aluminum and various paints) to determine the surface material.

  15. Design Tools for FRIB Fragment Separators

    Science.gov (United States)

    Bandura, Laura

    2009-10-01

    A key component of the Facility for Rare Isotope Beams, FRIB will be the in-flight fragment separator used to select and purify the isotope of interest for experiments. In order to simulate this process, we have developed a hybrid map-Monte Carlo code based on the ion optics code COSY INFINITY that accurately models fragment production and atomic processes. The code COSY INFINTIY uses powerful differential algebraic methods for computing the dynamics of the beam in the fragment separator. Ion production and atomic processes have been added to COSY to calculate beam-material interactions. The code tracks the fragmentation and fission of the beam in target and absorber material while computing energy loss and energy and angular straggling as well as charge state evolution of the beam by implementing auxiliary codes such as ATIMA and GLOBAL. EPAX has been utilized to return the cross sections of fragmentation products. The hybrid map-Monte Carlo code extensions added to COSY provide an integrated beam dynamics-nuclear processes design optimization and simulation framework that is efficient and accurate. The code may be used to optimize any fragment separator system for the selection of any rare isotope.

  16. Core stability and bicycling.

    Science.gov (United States)

    Asplund, Chad; Ross, Michael

    2010-01-01

    Bicycling is a popular fitness activity in the United States and around the world. Because of the nature of the bicycling position, the neck and back are at risk for injury. One method to prevent these injuries is to ensure that the body's "core" is strong and stable. A strong and stable core also provides a platform to maximize power transfer, improving performance. Core exercises also may enhance recovery from intense bicycling efforts. Simple stability exercises can improve performance and may prevent injuries in bicyclists.

  17. IGCSE core mathematics

    CERN Document Server

    Wall, Terry

    2013-01-01

    Give your core level students the support and framework they require to get their best grades with this book dedicated to the core level content of the revised syllabus and written specifically to ensure a more appropriate pace. This title has been written for Core content of the revised Cambridge IGCSE Mathematics (0580) syllabus for first teaching from 2013. ? Gives students the practice they require to deepen their understanding through plenty of practice questions. ? Consolidates learning with unique digital resources on the CD, included free with every book. We are working with Cambridge

  18. Core shroud corner joints

    Science.gov (United States)

    Gilmore, Charles B.; Forsyth, David R.

    2013-09-10

    A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.

  19. Core and Valence Structures in K beta X-ray Emission Spectra of Chromium Materials

    NARCIS (Netherlands)

    Torres Deluigi, Maria; de Groot, Frank M. F.; Lopez-Diaz, Gaston; Tirao, German; Stutz, Guillermo; Riveros de la Vega, Jose

    2014-01-01

    We analyze the core and valence transitions in chromium in a series of materials with a number of different ligands and including the oxidation states: Cr-II, Cr-III, Cr-IV, and Cr-VI. To study the core-to-core transitions we employ the CTM4XAS program and investigate the shapes, widths,

  20. The Capitalist World-System and U.S. Cold War Policies in the Core and the Periphery: A Comparative Analysis of Post-World War II American Nation-building in Germany and Korea

    Directory of Open Access Journals (Sweden)

    Y. Hugh Jo

    2015-08-01

    Full Text Available In response to the emerging cold war, why did the United States stress industrial expansion in Western Europe but focus on primary production alongside policing operations in the non-western world? Examining US postwar occupation in Germany and Korea from a world-systems perspective, this article argues that a given country’s standing in the capitalist economy generally shapes American foreign policy toward that particular country in the early cold war years. A paladin of system-wide prosperity and peace, the United States sought to restore the international division of labor after World War II. Reactions varied across the system, however, because of distinct socio-economic developments. The presence of capital-intensive export-dependent industry afforded western Germany flexible labor-management relations. Politics was overall stable there, and America dispensed with heavy-handed intervention. In southern Korea, labor-exploitive tenancy farming rendered interclass compromise virtually impossible. As intransigent peasants threatened the market economy, the United States used force to keep the ally in the system.

  1. The Relationship between Habitat Loss and Fragmentation during Urbanization: An Empirical Evaluation from 16 World Cities.

    Directory of Open Access Journals (Sweden)

    Zhifeng Liu

    Full Text Available Urbanization results in habitat loss and habitat fragmentation concurrently, both influencing biodiversity and ecological processes. To evaluate these impacts, it is important to understand the relationships between habitat loss and habitat fragmentation per se (HLHF during urbanization. The objectives of this study were two-fold: 1 to quantify the different forms of the HLHF relationship during urbanization using multiple landscape metrics, and 2 to test the validity of the HLHF relations reported in the literature. Our analysis was based on a long-term urbanization dataset (1800-2000 of 16 large cities from around the world. Habitat area was represented as the percentage of non-built-up area in the landscape, while habitat fragmentation was measured using several landscape metrics. Our results show that the relationship between habitat loss and habitat fragmentation during urbanization is commonly monotonic-linear, exponential, or logarithmic, indicating that the degree of habitat fragmentation per se increases with habitat loss in general. We compared our results with 14 hypothesized HLHF relationships based on simulated landscapes found in the literature, and found that four of them were consistent with those of urbanization, whereas the other ten were not. Also, we identified six new HLHF relationships when fragmentation was measured by total core area, normalized total core area, patch density, edge density and landscape shape index, respectively. In addition, our study demonstrated that the "space-for-time" approach, frequently used in ecology and geography, generated specious HLHF relationships, suggesting that this approach is largely inappropriate for analyses of urban landscapes that are highly heterogeneous in space and unusually contingent in dynamics. Our results show both generalities and idiosyncrasies of the HLHF relationship, providing new insights for assessing ecological effects of urbanization.

  2. The Relationship between Habitat Loss and Fragmentation during Urbanization: An Empirical Evaluation from 16 World Cities.

    Science.gov (United States)

    Liu, Zhifeng; He, Chunyang; Wu, Jianguo

    2016-01-01

    Urbanization results in habitat loss and habitat fragmentation concurrently, both influencing biodiversity and ecological processes. To evaluate these impacts, it is important to understand the relationships between habitat loss and habitat fragmentation per se (HLHF) during urbanization. The objectives of this study were two-fold: 1) to quantify the different forms of the HLHF relationship during urbanization using multiple landscape metrics, and 2) to test the validity of the HLHF relations reported in the literature. Our analysis was based on a long-term urbanization dataset (1800-2000) of 16 large cities from around the world. Habitat area was represented as the percentage of non-built-up area in the landscape, while habitat fragmentation was measured using several landscape metrics. Our results show that the relationship between habitat loss and habitat fragmentation during urbanization is commonly monotonic-linear, exponential, or logarithmic, indicating that the degree of habitat fragmentation per se increases with habitat loss in general. We compared our results with 14 hypothesized HLHF relationships based on simulated landscapes found in the literature, and found that four of them were consistent with those of urbanization, whereas the other ten were not. Also, we identified six new HLHF relationships when fragmentation was measured by total core area, normalized total core area, patch density, edge density and landscape shape index, respectively. In addition, our study demonstrated that the "space-for-time" approach, frequently used in ecology and geography, generated specious HLHF relationships, suggesting that this approach is largely inappropriate for analyses of urban landscapes that are highly heterogeneous in space and unusually contingent in dynamics. Our results show both generalities and idiosyncrasies of the HLHF relationship, providing new insights for assessing ecological effects of urbanization.

  3. The Relationship between Habitat Loss and Fragmentation during Urbanization: An Empirical Evaluation from 16 World Cities

    Science.gov (United States)

    He, Chunyang

    2016-01-01

    Urbanization results in habitat loss and habitat fragmentation concurrently, both influencing biodiversity and ecological processes. To evaluate these impacts, it is important to understand the relationships between habitat loss and habitat fragmentation per se (HLHF) during urbanization. The objectives of this study were two-fold: 1) to quantify the different forms of the HLHF relationship during urbanization using multiple landscape metrics, and 2) to test the validity of the HLHF relations reported in the literature. Our analysis was based on a long-term urbanization dataset (1800–2000) of 16 large cities from around the world. Habitat area was represented as the percentage of non-built-up area in the landscape, while habitat fragmentation was measured using several landscape metrics. Our results show that the relationship between habitat loss and habitat fragmentation during urbanization is commonly monotonic—linear, exponential, or logarithmic, indicating that the degree of habitat fragmentation per se increases with habitat loss in general. We compared our results with 14 hypothesized HLHF relationships based on simulated landscapes found in the literature, and found that four of them were consistent with those of urbanization, whereas the other ten were not. Also, we identified six new HLHF relationships when fragmentation was measured by total core area, normalized total core area, patch density, edge density and landscape shape index, respectively. In addition, our study demonstrated that the “space-for-time” approach, frequently used in ecology and geography, generated specious HLHF relationships, suggesting that this approach is largely inappropriate for analyses of urban landscapes that are highly heterogeneous in space and unusually contingent in dynamics. Our results show both generalities and idiosyncrasies of the HLHF relationship, providing new insights for assessing ecological effects of urbanization. PMID:27124180

  4. Fragment library design: using cheminformatics and expert chemists to fill gaps in existing fragment libraries.

    Science.gov (United States)

    Kutchukian, Peter S; So, Sung-Sau; Fischer, Christian; Waller, Chris L

    2015-01-01

    Fragment based screening (FBS) has emerged as a mainstream lead discovery strategy in academia, biotechnology start-ups, and large pharma. As a prerequisite of FBS, a structurally diverse library of fragments is desirable in order to identify chemical matter that will interact with the range of diverse target classes that are prosecuted in contemporary screening campaigns. In addition, it is also desirable to offer synthetically amenable starting points to increase the probability of a successful fragment evolution through medicinal chemistry. Herein we describe a method to identify biologically relevant chemical substructures that are missing from an existing fragment library (chemical gaps), and organize these chemical gaps hierarchically so that medicinal chemists can efficiently navigate the prioritized chemical space and subsequently select purchasable fragments for inclusion in an enhanced fragment library.

  5. Yeast vacuoles fragment in an asymmetrical two-phase process with distinct protein requirements

    Science.gov (United States)

    Zieger, Martin; Mayer, Andreas

    2012-01-01

    Yeast vacuoles fragment and fuse in response to environmental conditions, such as changes in osmotic conditions or nutrient availability. Here we analyze osmotically induced vacuole fragmentation by time-lapse microscopy. Small fragmentation products originate directly from the large central vacuole. This happens by asymmetrical scission rather than by consecutive equal divisions. Fragmentation occurs in two distinct phases. Initially, vacuoles shrink and generate deep invaginations that leave behind tubular structures in their vicinity. Already this invagination requires the dynamin-like GTPase Vps1p and the vacuolar proton gradient. Invaginations are stabilized by phosphatidylinositol 3-phosphate (PI(3)P) produced by the phosphoinositide 3-kinase complex II. Subsequently, vesicles pinch off from the tips of the tubular structures in a polarized manner, directly generating fragmentation products of the final size. This phase depends on the production of phosphatidylinositol-3,5-bisphosphate and the Fab1 complex. It is accelerated by the PI(3)P- and phosphatidylinositol 3,5-bisphosphate–binding protein Atg18p. Thus vacuoles fragment in two steps with distinct protein and lipid requirements. PMID:22787281

  6. Mapping of the antigenic and allergenic epitopes of Lol p VB using gene fragmentation.

    Science.gov (United States)

    Ong, E K; Knox, R B; Singh, M B

    1995-03-01

    The recombinant proteins of Lol p VA and Lol p VB expressed in E. coli reacted with IgE antibodies from sera of allergic patients and mAbs FMC A7 and PpV1. Cross-absorption analyses using these recombinant proteins showed that Lol p VA and Lol p VB possess both similar and unique IgE binding determinants. Gene fragmentation was utilized to localize the antigenic and allergenic determinants of Lol p VB. When full-length cDNA of Lol p VB was digested into three fragments and expressed as the fusions from the glutathione transferase of pGEX vectors, fragments Met1-Val196 and Asp197-Val339 bound IgE while fragment Met1-Pro96 did not. The data suggest that there are at least two IgE binding determinants in Lol p VB. In addition, only fragment Met1-Val196 reacted with mAb PpV1. The localization of these determinants was further resolved using random fragment expression libraries. The mAb PpV1 determinant was near the N-terminal region of Lol p VB molecule. The IgE binding determinants were distributed in the central region: region I (amino acids 111-195) and II (199-254). These IgE binding determinants are conserved in Lol p VA.

  7. Predicting effects of rainforest fragmentation from live trapping studies of small mammals in Sri Lanka

    Directory of Open Access Journals (Sweden)

    M.R. Wijesinghe

    2012-06-01

    Full Text Available This paper examines the impact of forest fragmentation on small mammals inhabiting the rainforests of Sri Lanka. Fifteen forests ranging in size from 145 to 11000 ha were live-trapped for five to eight nights each in both interior and edge habitats, yielding a total of 18400 trap nights. A total of 444 individuals belonging to 10 species of small mammals were captured. Multiple-regression analysis incorporating three indicators of fragmentation: patch area, shape index (perimeter/area and degree of isolation, showed no significant effects on overall species richness of small mammals. This is likely because the decline of forest-adapted species from small forest fragments was accompanied by an increase in more tolerant and adaptive species. Patch size, however, had a significant positive effect on the abundance of small mammals. Of the two dominant species, the endemic Mus mayori was positively affected by patch area whilst Rattus rattus was not affected. Although no differences were evident between interior and edge habitats with respect to total species richness and abundance, endemics were more abundant in core areas while the reverse was true for the non-endemics. Core forest areas were significantly different from forest edges with respect to canopy cover, density of herbaceous vegetation, large trees and litter cover. These results suggest that forest fragmentation is detrimental to some forest specialists and beneficial to some generalists.

  8. The use of autologous adult, allogenic juvenile, and combined juvenile-adult cartilage fragments for the repair of chondral defects.

    Science.gov (United States)

    Bonasia, Davide Edoardo; Martin, James A; Marmotti, Antonio; Kurriger, Gail L; Lehman, Abigail D; Rossi, Roberto; Amendola, Annunziato

    2016-12-01

    The goal of the study was to evaluate the repair of chondral lesions treated with combined autologous adult/allogenic juvenile cartilage fragments, compared with isolated adult and isolated juvenile cartilage fragments. Fifty-eight adult (>16 week old) and five juvenile (cartilage fragments; Group 3 = juvenile cartilage fragments; and Group 4 = adult + juvenile cartilage fragments. Killings were performed at 3 and 6 months. The defects were evaluated with ICRS macroscopic score, modified O'Driscoll score, and Collagen type II immunostaining. At 3 months, Group 4 performed better than Group 1, in terms of modified O'Driscoll score (p = 0.001) and Collagen type II immunostaining (p = 0.015). At 6 months, Group 4 showed higher modified O'Driscoll score (p = 0.003) and Collagen type II immunostaining score (p cartilage fragments improved cartilage repair in a rabbit model. In the clinical setting, a new "one-stage" procedure combining the two cartilage sources can be hypothesized, with the advantages of improved chondral repair and large defect coverage, because of the use of an off-the-shelf juvenile allograft. Further studies on larger animals and clinical trials are required to confirm these results.

  9. (II) complexes

    African Journals Online (AJOL)

    activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

  10. INTEGRAL core programme

    Science.gov (United States)

    Gehrels, N.; Schoenfelder, V.; Ubertini, P.; Winkler, C.

    1997-01-01

    The International Gamma Ray Astrophysics Laboratory (INTEGRAL) mission is described with emphasis on the INTEGRAL core program. The progress made in the planning activities for the core program is reported on. The INTEGRAL mission has a nominal lifetime of two years with a five year extension option. The observing time will be divided between the core program (between 30 and 35 percent during the first two years) and general observations. The core program consists of three main elements: the deep survey of the Galactic plane in the central radian of the Galaxy; frequent scans of the Galactic plane in the search for transient sources, and pointed observations of several selected sources. The allocation of the observation time is detailed and the sensitivities of the observations are outlined.

  11. The core helium flash

    Science.gov (United States)

    Cole, P. W.; Deupree, R. G.

    1980-12-01

    The role of convection in the core helium flash is simulated by two-dimensional eddies interacting with the thermonuclear runaway. These eddies are followed by the explicit solution of the two-dimensional conservation laws with a two-dimensional finite difference hydrodynamics code. Thus, no phenomenological theory of convection such as the local mixing length theory is required. The core helium flash is violent, producing a deflagration wave. This differs from the detonation wave (and subsequent disruption of the entire star) produced in previous spherically symmetric violent core helium flashes as the second dimension provides a degree of relief which allows the expansion wave to decouple itself from the burning front. The results predict that a considerable amount of helium in the core will be burned before the horizontal branch is reached and that some envelope mass loss is likely.

  12. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    Civil servants conduct the work which makes welfare states functions on an everyday bases: Police men police, school teachers teach, and tax inspectors inspect. Focus in this paper is on the core tasks of tax inspectors. The paper argues that their core task of securing the collection of revenue...... has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...

  13. Reference: -300CORE [PLACE

    Lifescience Database Archive (English)

    Full Text Available -300CORE Forde BG, Heyworth A, Pywell J, Kreis M Nucleotide sequence of a B1 hordein gene and the identifica...tion of possible upstream regulatory elements in endosperm storage protein genes fr

  14. iPSC Core

    Data.gov (United States)

    Federal Laboratory Consortium — The induced Pluripotent Stem Cells (iPSC) Core was created in 2011 to accelerate stem cell research in the NHLBI by providing investigators consultation, technical...

  15. The Core Knowledge System

    National Research Council Canada - National Science Library

    Strat, Thomas M; Smith, Grahame B

    1987-01-01

    This document contains an in-depth description of the Core Knowledge System (CKS)-an integrative environment for the many functions that must be performed by sensor-based autonomous and semi-autonomous systems...

  16. METHOD FOR CONTROLLING FRAGMENTATION OF DRIED FOOD DURING COMPRESSION

    Science.gov (United States)

    readily with little fragmentation to original characteristics. Examination included 15 food types. Measurement of fragmentation is described. Storage stability is reported. A progress flow chart is included.

  17. Double sequence core theorems

    Directory of Open Access Journals (Sweden)

    Richard F. Patterson

    1999-01-01

    Full Text Available In 1900, Pringsheim gave a definition of the convergence of double sequences. In this paper, that notion is extended by presenting definitions for the limit inferior and limit superior of double sequences. Also the core of a double sequence is defined. By using these definitions and the notion of regularity for 4-dimensional matrices, extensions, and variations of the Knopp Core theorem are proved.

  18. Core Gene Set As the Basis of Multilocus Sequence Analysis of the Subclass Actinobacteridae

    Science.gov (United States)

    Adékambi, Toïdi; Butler, Ray W.; Hanrahan, Finnian; Delcher, Arthur L.; Drancourt, Michel; Shinnick, Thomas M.

    2011-01-01

    Comparative genomic sequencing is shedding new light on bacterial identification, taxonomy and phylogeny. An in silico assessment of a core gene set necessary for cellular functioning was made to determine a consensus set of genes that would be useful for the identification, taxonomy and phylogeny of the species belonging to the subclass Actinobacteridae which contained two orders Actinomycetales and Bifidobacteriales. The subclass Actinobacteridae comprised about 85% of the actinobacteria families. The following recommended criteria were used to establish a comprehensive gene set; the gene should (i) be long enough to contain phylogenetically useful information, (ii) not be subject to horizontal gene transfer, (iii) be a single copy (iv) have at least two regions sufficiently conserved that allow the design of amplification and sequencing primers and (v) predict whole-genome relationships. We applied these constraints to 50 different Actinobacteridae genomes and made 1,224 pairwise comparisons of the genome conserved regions and gene fragments obtained by using Sequence VARiability Analysis Program (SVARAP), which allow designing the primers. Following a comparative statistical modeling phase, 3 gene fragments were selected, ychF, rpoB, and secY with R2>0.85. Selected sets of broad range primers were tested from the 3 gene fragments and were demonstrated to be useful for amplification and sequencing of 25 species belonging to 9 genera of Actinobacteridae. The intraspecies similarities were 96.3–100% for ychF, 97.8–100% for rpoB and 96.9–100% for secY among 73 strains belonging to 15 species of the subclass Actinobacteridae compare to 99.4–100% for 16S rRNA. The phylogenetic topology obtained from the combined datasets ychF+rpoB+secY was globally similar to that inferred from the 16S rRNA but with higher confidence. It was concluded that multi-locus sequence analysis using core gene set might represent the first consensus and valid approach for

  19. Improving the calculated core stability by the core nuclear design optimization

    Energy Technology Data Exchange (ETDEWEB)

    Partanen, P. [Teollisuuden Voima Oy, Olkiluoto (Finland)

    1995-12-31

    Three different equilibrium core loadings for TVO II reactor have been generated in order to improve the core stability properties at uprated power level. The reactor thermal power is assumed to be uprated from 2160 MW{sub th} to 2500 MW{sub th}, which moves the operating point after a rapid pump rundown where the core stability has been calculated from 1340 MW{sub th} and 3200 kg/s to 1675 MW{sub th} and 4000 kg/s. The core has been refuelled with ABB Atom Svea-100 -fuel, which has 3,64% w/o U-235 average enrichment in the highly enriched zone. PHOENIX lattice code has been used to provide the homogenized nuclear constants. POLCA4 static core simulator has been used for core loadings and cycle simulations and RAMONA-3B program for simulating the dynamic response to the disturbance for which the stability behaviour has been evaluated. The core decay ratio has been successfully reduced from 0,83 to 0,55 mainly by reducing the power peaking factors. (orig.) (7 figs., 1 tab.).

  20. Deployment of a three-dimensional array of Micro-Pocket Fission Detector triads (MPFD3) for real-time, in-core neutron flux measurements in the Kansas State University TRIGA Mark-II Nuclear Reactor

    Science.gov (United States)

    Ohmes, Martin Francis

    A Micro-Pocket Fission Detector (MPFD) is a miniaturized type of fission chamber developed for use inside a nuclear reactor. Their unique design allows them to be located between or even inside fuel pins while being built from materials which give them an operational lifetime comparable to or exceeding the life of the fuel. While other types of neutron detectors have been made for use inside a nuclear reactor, the MPFD is the first neutron detector which can survive sustained use inside a nuclear reactor while providing a real-time measurement of the neutron flux. This dissertation covers the deployment of MPFDs as a large three-dimensional array inside the Kansas State University TRIGA Mark-II Nuclear Reactor for real-time neutron flux measurements. This entails advancements in the design, construction, and packaging of the Micro-Pocket Fission Detector Triads with incorporated Thermocouple, or MPFD3-T. Specialized electronics and software also had to be designed and built in order to make a functional system capable of collecting real-time data from up to 60 MPFD3-Ts, or 180 individual MPFDs and 60 thermocouples. Design of the electronics required the development of detailed simulations and analysis for determining the theoretical response of the detectors and determination of their size. The results of this research shows that MPFDs can operate for extended times inside a nuclear reactor and can be utilized toward the use as distributed neutron detector arrays for advanced reactor control systems and power mapping. These functions are critical for continued gains in efficiency of nuclear power reactors while also improving safety through relatively inexpensive redundancy.

  1. Cores, filaments, and bundles: hierarchical core formation in the L1495/B213 Taurus region

    Science.gov (United States)

    Hacar, A.; Tafalla, M.; Kauffmann, J.; Kovács, A.

    2013-06-01

    Context. Core condensation is a critical step in the star-formation process, but it is still poorly characterized observationally. Aims: We have studied the 10 pc-long L1495/B213 complex in Taurus to investigate how dense cores have condensed out of the lower density cloud material. Methods: We observed L1495/B213 in C18O(1-0), N2H+(1-0), and SO(JN = 32-21) with the 14 m FCRAO telescope, and complemented the data with dust continuum observations using APEX (870 μm) and IRAM 30 m (1200 μm). Results: From the N2H+ emission, we identify 19 dense cores, some starless and some protostellar. They are not distributed uniformly, but tend to cluster with relative separations on the order of 0.25 pc. From the C18O emission, we identify multiple velocity components in the gas. We have characterized them by fitting Gaussians to the spectra and by studying the distribution of the fits in position-position-velocity space. In this space, the C18O components appear as velocity-coherent structures, and we identify them automatically using a dedicated algorithm (FIVE: Friends In VElocity). Using this algorithm, we identify 35 filamentary components with typical lengths of 0.5 pc, sonic internal velocity dispersions, and mass-per-unit length close to the stability threshold of isothermal cylinders at 10 K. Core formation seems to have occurred inside the filamentary components via fragmentation, with few fertile components with higher mass-per-unit length being responsible for most cores in the cloud. On large scales, the filamentary components appear grouped into families, which we refer to as bundles. Conclusions: Core formation in L1495/B213 has proceeded by hierarchical fragmentation. The cloud fragmented first into several pc-scale regions. Each of these regions later fragmented into velocity-coherent filaments of about 0.5 pc in length. Finally, a small number of these filaments fragmented quasi-statically and produced the individual dense cores we see today. Based on

  2. MCNP LWR Core Generator

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Noah A. [Los Alamos National Laboratory

    2012-08-14

    The reactor core input generator allows for MCNP input files to be tailored to design specifications and generated in seconds. Full reactor models can now easily be created by specifying a small set of parameters and generating an MCNP input for a full reactor core. Axial zoning of the core will allow for density variation in the fuel and moderator, with pin-by-pin fidelity, so that BWR cores can more accurately be modeled. LWR core work in progress: (1) Reflectivity option for specifying 1/4, 1/2, or full core simulation; (2) Axial zoning for moderator densities that vary with height; (3) Generating multiple types of assemblies for different fuel enrichments; and (4) Parameters for specifying BWR box walls. Fuel pin work in progress: (1) Radial and azimuthal zoning for generating further unique materials in fuel rods; (2) Options for specifying different types of fuel for MOX or multiple burn assemblies; (3) Additional options for replacing fuel rods with burnable poison rods; and (4) Control rod/blade modeling.

  3. Meteorite Falls and the Fragmentation of Meteorites

    Science.gov (United States)

    Momeni, Daniel

    2016-01-01

    In order to understand the fragmentation of objects entering the atmosphere and why some produce more fragments than others, I have searched the Meteoritical Society database for meteorites greater than 20 kilograms that fell in the USA, China, and India. I also studied the video and film records of 21 fireballs that produced meteorites. A spreadsheet was prepared that noted smell, fireball, explosion, whistling, rumbling, the number of fragments, light, and impact sounds. Falls with large numbers of fragments were examined to look for common traits. These were: the Norton County aubrite, explosion and a flare greater than 100 fragments; the Forest City H5 chondrite explosion, a flare, a dust trail, 505 specimens; the Richardton H5 chondrite explosion and light, 71 specimens; the Juancheng H5 chondrite explosion, a rumbling, a flare, a dust trail,1000 specimens; the Tagish Lake C2 chondrite explosion, flare, dust trail, 500 specimens. I conclude that fragmentation is governed by the following: (1) Bigger meteors undergo more stress which results in more specimens; (2) Harder meteorites also require more force to break them up which will cause greater fragmentation; (3) Force and pressure are directly proportional during falls. General observations made were; (1) Meteorites produce fireballs sooner due to high friction; (2) Meteors tend to explode as well because of high stress; (3) Softer meteorites tend to cause dust trails; (4) Some falls produce light as they fall at high velocity. I am grateful to NASA Ames for this opportunity and Derek Sears, Katie Bryson, and Dan Ostrowski for discussions.

  4. DNA fragmentation in spermatozoa: a historical review.

    Science.gov (United States)

    Rex, A S; Aagaard, J; Fedder, J

    2017-07-01

    Sperm DNA Fragmentation has been extensively studied for more than a decade. In the 1940s the uniqueness of the spermatozoa protein complex which stabilizes the DNA was discovered. In the fifties and sixties, the association between unstable chromatin structure and subfertility was investigated. In the seventies, the impact of induced DNA damage was investigated. In the 1980s the concept of sperm DNA fragmentation as related to infertility was introduced as well as the first DNA fragmentation test: the Sperm Chromatin Structure Assay (SCSA). The terminal deoxynucleotidyl transferase nick end labelling (TUNEL) test followed by others was introduced in the nineties. The association between DNA fragmentation in spermatozoa and pregnancy loss has been extensively investigated spurring the need for a therapeutic tool for these patients. This gave rise to an increased interest in the aetiology of DNA damage. The present decade continues within this research area. Some of the more novel methods recently submerging are sorting of cells with increased DNA fragmentation and hyaluronic acid (HA) binding techniques. The clinical value of these tests remains to be elucidated. In spite of half a century of research within the area, this analysis is not routinely implemented into the fertility clinics. The underlying causes are multiple. The abundance of methods has impeded the need for a clinical significant threshold. One of the most promising methods was commercialized in 2005 and has been reserved for larger licensed laboratories. Myriads of reviews and meta-analyses on studies using different assays for analysis of DNA fragmentation, different clinical Artificial Reproductive Treatments (ART), different definitions of successful ART outcome and small patient cohorts have been published. Although the area of DNA fragmentation in spermatozoa is highly relevant in the fertility clinics, the need for further studies focusing on standardization of the methods and clinical

  5. Novel methods and expected run II performance of ATLAS track reconstruction in dense environments

    CERN Document Server

    Jansky, Roland Wolfgang; The ATLAS collaboration

    2015-01-01

    Detailed understanding and optimal track reconstruction performance of ATLAS in the core of high pT objects is paramount for a number of techniques such as jet energy and mass calibration, jet flavour tagging, and hadronic tau identification as well as measurements of physics quantities like jet fragmentation functions. These dense environments are characterized by charged particle separations on the order of the granularity of ATLAS’s inner detector. With the insertion of a new innermost layer in this tracking detector, which allows measurements closer to the interaction point, and an increase in the centre of mass energy, these difficult environments will become even more relevant in Run II, such as in searches for heavy resonances. Novel algorithmic developments to the ATLAS track reconstruction software targeting these topologies as well as the expected improved performance will be presented.

  6. An abiotic analogue of the diiron(IV)oxo "diamond core" of soluble methane monooxygenase generated by direct activation of O2 in aqueous Fe(II)/EDTA solutions: thermodynamics and electronic structure.

    Science.gov (United States)

    Bernasconi, Leonardo; Belanzoni, Paola; Baerends, Evert Jan

    2011-09-07

    We study the generation of a dinuclear Fe(IV)oxo species, [EDTAH·FeO·OFe·EDTAH](2-), in aqueous solution at room temperature using Density Functional Theory (DFT) and Ab Initio Molecular Dynamics (AIMD). This species has been postulated as an intermediate in the multi-step mechanism of autoxidation of Fe(II) to Fe(III) in the presence of atmospheric O(2) and EDTA ligand in water. We examine the formation of [EDTAH·FeO·OFe·EDTAH](2-) by direct cleavage of O(2), and the effects of solvation on the spin state and O-O cleavage barrier. We also study the reactivity of the resulting dinuclear Fe(IV)oxo system in CH(4) hydroxylation, and its tendency to decompose to mononuclear Fe(IV)oxo species. The presence of the solvent is shown to play a crucial role, determining important changes in all these processes compared to the gas phase. We show that, in water solution, [EDTAH·FeO·OFe·EDTAH](2-) (as well as its precursor [EDTAH·Fe·O(2)·Fe·EDTAH](2-)) exists as stable species in a S = 4 ground spin state when hydrogen-bonded to a single water molecule. Its structure comprises two facing Fe(IV)oxo groups, in an arrangement similar to the one evinced for the active centre of intermediate Q of soluble Methane Monooxygenase (sMMO). The inclusion of the water molecule in the complex decreases the overall symmetry of the system, and brings about important changes in the energy and spatial distribution of orbitals of the Fe(IV)oxo groups relative to the gas phase. In particular, the virtual 3σ* orbital of one of the Fe(IV)oxo groups experiences much reduced repulsive orbital interactions from ligand orbitals, and its consequent stabilisation dramatically enhances the electrophilic character of the complex, compared to the symmetrical non-hydrated species, and its ability to act as an acceptor of a H atom from the CH(4) substrate. The computed free energy barrier for H abstraction is 28.2 kJ mol(-1) (at the BLYP level of DFT), considerably below the gas phase value for

  7. EBR-II Data Digitization

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Su-Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sackett, John [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-08-01

    1. Objectives To produce a validation database out of those recorded signals it will be necessary also to identify the documents need to reconstruct the status of reactor at the time of the beginning of the recordings. This should comprehends the core loading specification (assemblies type and location and burn-up) along with this data the assemblies drawings and the core drawings will be identified. The first task of the project will be identify the location of the sensors, with respect the reactor plant layout, and the physical quantities recorded by the Experimental Breeder Reactor-II (EBR-II) data acquisition system. This first task will allow guiding and prioritizing the selection of drawings needed to numerically reproduce those signals. 1.1 Scopes and Deliverables The deliverables of this project are the list of sensors in EBR-II system, the identification of storing location of those sensors, identification of a core isotopic composition at the moment of the start of system recording. Information of the sensors in EBR-II reactor system was summarized from the EBR-II system design descriptions listed in Section 1.2.

  8. Global-Scale Patterns of Forest Fragmentation

    Directory of Open Access Journals (Sweden)

    Kurt Riitters

    2000-12-01

    Full Text Available We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 x 9 pixels, "small" scale to 59,049 km 2 (243 x 243 pixels, "large" scale were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe-Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types and Europe-Asia (four types, in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland. The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf.

  9. 3D puzzle reconstruction for archeological fragments

    Science.gov (United States)

    Jampy, F.; Hostein, A.; Fauvet, E.; Laligant, O.; Truchetet, F.

    2015-03-01

    The reconstruction of broken artifacts is a common task in archeology domain; it can be supported now by 3D data acquisition device and computer processing. Many works have been dedicated in the past to reconstructing 2D puzzles but very few propose a true 3D approach. We present here a complete solution including a dedicated transportable 3D acquisition set-up and a virtual tool with a graphic interface allowing the archeologists to manipulate the fragments and to, interactively, reconstruct the puzzle. The whole lateral part is acquired by rotating the fragment around an axis chosen within a light sheet thanks to a step-motor synchronized with the camera frame clock. Another camera provides a top view of the fragment under scanning. A scanning accuracy of 100μm is attained. The iterative automatic processing algorithm is based on segmentation into facets of the lateral part of the fragments followed by a 3D matching providing the user with a ranked short list of possible assemblies. The device has been applied to the reconstruction of a set of 1200 fragments from broken tablets supporting a Latin inscription dating from the first century AD.

  10. Stream hydrological fragmentation drives bacterioplankton community composition.

    Directory of Open Access Journals (Sweden)

    Stefano Fazi

    Full Text Available In Mediterranean intermittent streams, the hydrological fragmentation in summer and the successive water flow re-convergence in autumn allow exploring how local processes shape the microbial community within the same habitat. The objectives of this study were to determine how bacterial community composition responded to hydrological fragmentation in summer, and to evaluate whether the seasonal shifts in community composition predominate over the effects of episodic habitat fragmentation. The bacterial community was assessed along the intermittent stream Fuirosos (Spain, at different levels of phylogenetic resolution by in situ hybridization, fingerprinting, and 16S rRNA gene sequencing. The hydrological fragmentation of the stream network strongly altered the biogeochemical conditions with the depletion of oxidized solutes and caused changes in dissolved organic carbon characteristics. In the isolated ponds, beta-Proteobacteria and Actinobacteria increased their abundance with a gradual reduction of the alpha-diversity as pond isolation time increased. Moreover, fingerprinting analysis clearly showed a shift in community composition between summer and autumn. In the context of a seasonal shift, the temporary stream fragmentation simultaneously reduced the microbial dispersion and affected local environmental conditions (shift in redox regime and quality of the dissolved organic matter tightly shaping the bacterioplankton community composition.

  11. Correlation measurements of fission-fragment properties

    Directory of Open Access Journals (Sweden)

    Oberstedt A.

    2010-10-01

    Full Text Available For the development of future nuclear fission applications and for a responsible handling of nuclear waste the a-priori assessment of the fission-fragments’ heat production and toxicity is a fundamental necessity. The success of an indispensable modelling of the fission process strongly depends on a good understanding of the particular mechanism of scission, the mass fragmentation and partition of excitation energy. Experimental observables are fission-fragment properties like mass- and energy-distributions, and the prompt neutron as well as γ-ray multiplicities and emission spectra. The latter quantities should preferably be known as a function of fragment mass and excitation energy. Those data are highly demanded as published by the OECD-NEA in its high priority data request list. With the construction of the double (v, E spectrometer VERDI we aim at measuring pre- and post-neutron masses directly and simultaneously to avoid prompt neutron corrections. From the simultaneous measurement of pre- and post-neutron fission-fragment data the prompt neutron multiplicity may then be inferred fully correlated with fragment mass yield and total kinetic energy. Using an ultra-fast fission event trigger spectral prompt fission γ-ray measurements may be performed. For that purpose recently developed lanthanum-halide detectors, with excellent timing characteristics, were coupled to the VERDI spectrometer allowing for a very good discrimination of fission γ-rays and prompt neutrons due to their different time-of-flight.

  12. Dendrite fragmentation: an experiment-driven simulation.

    Science.gov (United States)

    Cool, T; Voorhees, P W

    2018-02-28

    The processes leading to the fragmentation of secondary dendrite arms are studied using a three-dimensional Sn dendritic structure that was measured experimentally as an initial condition in a phase-field simulation. The phase-field model replicates the kinetics of the coarsening process seen experimentally. Consistent with the experiment, the simulations of the Sn-rich dendrite show that secondary dendrite arm coalescence is prevalent and that fragmentation is not. The lack of fragmentation is due to the non-axisymmetric morphology and comparatively small spacing of the dendrite arms. A model for the coalescence process is proposed, and, consistent with the model, the radius of the contact region following coalescence increases as t1/3 We find that small changes in the width and spacing of the dendrite arms can lead to a very different fragmentation-dominated coarsening process. Thus, the alloy system and growth conditions of the dendrite can have a major impact on the fragmentation process.This article is part of the theme issue 'From atomistic interfaces to dendritic patterns'. © 2018 The Author(s).

  13. Dendrite fragmentation: an experiment-driven simulation

    Science.gov (United States)

    Cool, T.; Voorhees, P. W.

    2018-01-01

    The processes leading to the fragmentation of secondary dendrite arms are studied using a three-dimensional Sn dendritic structure that was measured experimentally as an initial condition in a phase-field simulation. The phase-field model replicates the kinetics of the coarsening process seen experimentally. Consistent with the experiment, the simulations of the Sn-rich dendrite show that secondary dendrite arm coalescence is prevalent and that fragmentation is not. The lack of fragmentation is due to the non-axisymmetric morphology and comparatively small spacing of the dendrite arms. A model for the coalescence process is proposed, and, consistent with the model, the radius of the contact region following coalescence increases as t1/3. We find that small changes in the width and spacing of the dendrite arms can lead to a very different fragmentation-dominated coarsening process. Thus, the alloy system and growth conditions of the dendrite can have a major impact on the fragmentation process. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  14. Packing in protein cores

    Science.gov (United States)

    Gaines, J. C.; Clark, A. H.; Regan, L.; O'Hern, C. S.

    2017-07-01

    Proteins are biological polymers that underlie all cellular functions. The first high-resolution protein structures were determined by x-ray crystallography in the 1960s. Since then, there has been continued interest in understanding and predicting protein structure and stability. It is well-established that a large contribution to protein stability originates from the sequestration from solvent of hydrophobic residues in the protein core. How are such hydrophobic residues arranged in the core; how can one best model the packing of these residues, and are residues loosely packed with multiple allowed side chain conformations or densely packed with a single allowed side chain conformation? Here we show that to properly model the packing of residues in protein cores it is essential that amino acids are represented by appropriately calibrated atom sizes, and that hydrogen atoms are explicitly included. We show that protein cores possess a packing fraction of φ ≈ 0.56 , which is significantly less than the typically quoted value of 0.74 obtained using the extended atom representation. We also compare the results for the packing of amino acids in protein cores to results obtained for jammed packings from discrete element simulations of spheres, elongated particles, and composite particles with bumpy surfaces. We show that amino acids in protein cores pack as densely as disordered jammed packings of particles with similar values for the aspect ratio and bumpiness as found for amino acids. Knowing the structural properties of protein cores is of both fundamental and practical importance. Practically, it enables the assessment of changes in the structure and stability of proteins arising from amino acid mutations (such as those identified as a result of the massive human genome sequencing efforts) and the design of new folded, stable proteins and protein-protein interactions with tunable specificity and affinity.

  15. Assessment of Fragmentation Performance of Blast-enhanced Explosive Fragmentation Munitions

    Science.gov (United States)

    2010-10-01

    weighing the individual fragments with precision electronic scales and measuring their average projected areas using the icosahedron gage technique...The icosahedron gage is an electro-optical devise that throws a shadow of a fragment on an electronic sensing surface resulting in an automated

  16. Bioinformatics Core Project Management

    Science.gov (United States)

    Vangala, Mahesh; Vincent, James; Driscoll, Heather

    2013-01-01

    Bioinformatics cores that provide fee for service style support encounter a wide variety of projects. The scope of projects varies greatly among investigators. Because of this variety, it is difficult to develop a set of predefined services that fit all project types. While our own core has developed a baseline set of services, we found in practice these often needed significant modification to meet the goals of particular investigator. To overcome this problem we factored common features of all projects and partitioned them into groups: workflow management, data management, user results, and tracking and reporting. We then implemented best practices for each group using commercial and open source software combined with our own management policies. Finally we linked these areas together to produce an overall integrated project management solution that combines workflow management, data management, user results management and reporting capabilities. This system solves the problem of developing well defined services that are trackable and repeatable while simultaneously enabling flexibility that is easily managed. The result improves the effectiveness and efficiency of the bioinformatics core for scientists working within the core, for investigators receiving core support and for external auditors and evaluators.

  17. Antiproton Induced Fission and Fragmentation of Nuclei

    CERN Multimedia

    2002-01-01

    The annihilation of slow antiprotons with nuclei results in a large highly localized energy deposition primarily on the nuclear surface. \\\\ \\\\ The study of antiproton induced fission and fragmentation processes is expected to yield new information on special nuclear matter states, unexplored fission modes, multifragmentation of nuclei, and intranuclear cascades.\\\\ \\\\ In order to investigate the antiproton-nucleus interaction and the processes following the antiproton annihilation at the nucleus, we propose the following experiments: \\item A)~Measurement of several fragments from fission and from multifragmentation in coincidence with particle spectra, especially neutrons and kaons. \\item B)~Precise spectra of $\\pi$, K, n, p, d and t with time-of-flight techniques. \\item C)~Installation of the Berlin 4$\\pi$ neutron detector with a 4$\\pi$ Si detector placed inside for fragments and charged particles. This yields neutron multiplicity distributions and consequently distributions of thermal excitation energies and...

  18. Characterizing DebriSat Fragments: So Many Fragments, So Much Data, and So Little Time

    Science.gov (United States)

    Shiotani, B.; Rivero, M.; Carrasquilla, M.; Allen, S.; Fitz-Coy, N.; Liou, J.-C.; Huynh, T.; Sorge, M.; Cowardin, H.; Opiela, J.; hide

    2017-01-01

    To improve prediction accuracy, the DebriSat project was conceived by NASA and DoD to update existing standard break-up models. Updating standard break-up models require detailed fragment characteristics such as physical size, material properties, bulk density, and ballistic coefficient. For the DebriSat project, a representative modern LEO spacecraft was developed and subjected to a laboratory hypervelocity impact test and all generated fragments with at least one dimension greater than 2 mm are collected, characterized and archived. Since the beginning of the characterization phase of the DebriSat project, over 130,000 fragments have been collected and approximately 250,000 fragments are expected to be collected in total, a three-fold increase over the 85,000 fragments predicted by the current break-up model. The challenge throughout the project has been to ensure the integrity and accuracy of the characteristics of each fragment. To this end, the post hypervelocity-impact test activities, which include fragment collection, extraction, and characterization, have been designed to minimize handling of the fragments. The procedures for fragment collection, extraction, and characterization were painstakingly designed and implemented to maintain the post-impact state of the fragments, thus ensuring the integrity and accuracy of the characterization data. Each process is designed to expedite the accumulation of data, however, the need for speed is restrained by the need to protect the fragments. Methods to expedite the process such as parallel processing have been explored and implemented while continuing to maintain the highest integrity and value of the data. To minimize fragment handling, automated systems have been developed and implemented. Errors due to human inputs are also minimized by the use of these automated systems. This paper discusses the processes and challenges involved in the collection, extraction, and characterization of the fragments as well as the

  19. Inner core structure behind the PKP core phase triplication

    NARCIS (Netherlands)

    Blom, Nienke A.; Deuss, Arwen; Paulssen, Hanneke; Waszek, Lauren

    The structure of the Earth's inner core is not well known between depths of ∼100–200 km beneath the inner core boundary. This is a result of the PKP core phase triplication and the existence of strong precursors to PKP phases, which hinder the measurement of inner core compressional PKIKP waves at

  20. Crystallographic fragment-based drug discovery: use of a brominated fragment library targeting HIV protease.

    Science.gov (United States)

    Tiefenbrunn, Theresa; Forli, Stefano; Happer, Meaghan; Gonzalez, Ana; Tsai, Yingssu; Soltis, Michael; Elder, John H; Olson, Arthur J; Stout, Charles D

    2014-02-01

    A library of 68 brominated fragments was screened against a new crystal form of inhibited HIV-1 protease in order to probe surface sites in soaking experiments. Often, fragments are weak binders with partial occupancy, resulting in weak, difficult-to-fit electron density. The use of a brominated fragment library addresses this challenge, as bromine can be located unequivocally via anomalous scattering. Data collection was carried out in an automated fashion using AutoDrug at SSRL. Novel hits were identified in the known surface sites: 3-bromo-2,6-dimethoxybenzoic acid (Br6) in the flap site and 1-bromo-2-naphthoic acid (Br27) in the exosite, expanding the chemistry of known fragments for development of higher affinity potential allosteric inhibitors. At the same time, mapping the binding sites of a number of weaker binding Br-fragments provides further insight into the nature of these surface pockets. © 2013 John Wiley & Sons A/S.

  1. Coordination Chemistry of Linear Oligopyrrolic Fragments Inspired by Heme Metabolites

    Science.gov (United States)

    Gautam, Ritika

    Linear oligopyrroles are degradation products of heme, which is converted in the presence of heme oxygenase to bile pigments, such as biliverdin and bilirubin. These tetrapyrrolic oligopyrroles are ubiquitously present in biological systems and find applications in the fields of catalysis and sensing. These linear tetrapyrrolic scaffolds are further degraded into linear tripyrrolic and dipyrrolic fragments. Although these lower oligopyrroles are abundantly present, their coordination chemistry requires further characterization. This dissertation focuses mainly on two classes of bioinspired linear oligopyrroles, propentdyopent and tripyrrindione, and their transition metal complexes, which present a rich ligand-based redox chemistry. Chapter 1 offers an overview of heme degradation to different classes of linear oligopyrroles and properties of their transition metal complexes. Chapter 2 is focused on the tripyrrin-1,14-dione scaffold of the urinary pigment uroerythrin, which coordinates divalent transition metals palladium and copper with square planar geometry. Specifically, the tripyrrin-1, 14-dione ligand binds Cu(II) and Pd(II) as a dianionic organic radical under ambient conditions. The electrochemical study confirms the presence of ligand based redox chemistry, and one electron oxidation or reduction reactions do not alter the planar geometry around the metal center. The X-Ray analysis and the electron paramagnetic resonance (EPR) studies of the complexes in the solid and solution phase reveals intermolecular interactions between the ligand based unpaired electrons and therefore formation of neutral pi-pi dimers. In Chapter 3, the antioxidant activity and the fluorescence sensor properties of the tripyrrin-1,14-dione ligand in the presence of superoxide are described. We found that the tripyrrindione ligand undergoes one-electron reduction in the presence of the superoxide radical anion (O2•- ) to form highly fluorescent H3TD1•- radical anion, which emits

  2. Dissipative fragmentation in a phase space approach

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.; Di Toro, M.; Bonasera, A.; Gregoire, C.; Gulminelli, F.

    Semi-classical approaches have evidenced the role of one and two-body dissipation in nucleus-nucleus collisions. On the other hand, a substantial energy dissipation and some angular momentum transfer have been observed at moderate energy where a fragmentation process is the dominant reaction mechanism. In order to analyse main features of these reactions, we developed a phenomenological model taking into account phase space constraints. The transition between deep inelastic collisions and abrasion-like fragmentation is described and a general agreement with available data is found.

  3. Parton Propagation and Fragmentation in QCD Matter

    Energy Technology Data Exchange (ETDEWEB)

    Alberto Accardi, Francois Arleo, William Brooks, David D' Enterria, Valeria Muccifora

    2009-12-01

    We review recent progress in the study of parton propagation, interaction and fragmentation in both cold and hot strongly interacting matter. Experimental highlights on high-energy hadron production in deep inelastic lepton-nucleus scattering, proton-nucleus and heavy-ion collisions, as well as Drell-Yan processes in hadron-nucleus collisions are presented. The existing theoretical frameworks for describing the in-medium interaction of energetic partons and the space-time evolution of their fragmentation into hadrons are discussed and confronted to experimental data. We conclude with a list of theoretical and experimental open issues, and a brief description of future relevant experiments and facilities.

  4. Computer Model Of Fragmentation Of Atomic Nuclei

    Science.gov (United States)

    Wilson, John W.; Townsend, Lawrence W.; Tripathi, Ram K.; Norbury, John W.; KHAN FERDOUS; Badavi, Francis F.

    1995-01-01

    High Charge and Energy Semiempirical Nuclear Fragmentation Model (HZEFRG1) computer program developed to be computationally efficient, user-friendly, physics-based program for generating data bases on fragmentation of atomic nuclei. Data bases generated used in calculations pertaining to such radiation-transport applications as shielding against radiation in outer space, radiation dosimetry in outer space, cancer therapy in laboratories with beams of heavy ions, and simulation studies for designing detectors for experiments in nuclear physics. Provides cross sections for production of individual elements and isotopes in breakups of high-energy heavy ions by combined nuclear and Coulomb fields of interacting nuclei. Written in ANSI FORTRAN 77.

  5. Measurement of delta13C and delta18O Isotopic Ratios of CaCO3 by a Thermoquest Finnigan GasBench II Delta Plus XL Continous Flow Isotope Ratio Mass Spectrometer with Application to Devils Hole Core DH-11 Calcite

    Science.gov (United States)

    Revesz, Kinga M.; Landwehr, Jurate Maciunas; Keybl, Jaroslav Edward

    2001-01-01

    A new method was developed to analyze the stable carbon and oxygen isotope ratios of small samples (400?20 ?g) of calcium carbonate. This new method streamlines the classical phosphoric acid - calcium carbonate (H3PO4 - CaCO3) reaction method by making use of a Thermoquest-Finnigan GasBench II preparation device and a Delta Plus XL continuous flow isotope ratio mass spectrometer. To obtain reproducible and accurate results, optimal conditions for the H3PO4 - CaCO3 reaction had to be determined. At the acid-carbonate reaction temperature suggested by the equipment manufacturer, the oxygen isotope ratio results were unsatisfactory (standard deviation () greater than 1.5 per mill), probably because of a secondary reaction. When the acid-carbonate reaction temperature was lowered to 26?C and the reaction time was increased to 24 hours, the precision of the carbon and oxygen isotope ratios for duplicate analyses improved to 0.1 and 0.2 per mill, respectively. The method was tested by analyzing calcite from Devils Hole, Nevada, which was formed by precipitation from ground water onto the walls of a sub-aqueous cavern during the last 500,000 years. Isotope-ratio values previously had been obtained by the classical method for Devils Hole core DH-11. The DH-11 core had been recently re-sampled, and isotope-ratio values were obtained using this new method. The results were comparable to those obtained by the classical method. The consistency of the isotopic results is such that an alignment offset could be identified in the re-sampled core material, a cutting error that was then independently confirmed. The reproducibility of the isotopic values is demonstrated by a correlation of approximately 0.96 for both isotopes, after correcting for an alignment offset. This result indicates that the new method is a viable alternative to the classical method. In particular, the new method requires less sample material permitting finer resolution and allows automation of some processes

  6. Suppression of MMP activity in bovine cartilage explants cultures has little if any effect on the release of aggrecanase-derived aggrecan fragments

    DEFF Research Database (Denmark)

    Wang, Bijue; Chen, Pingping; Jensen, Anne-Christine Bay

    2009-01-01

    -epitope specific immunoassays; (1) sandwich (342)FFGVG-G2 ELISA, (2) competition NITEGE(373)ELISA (3) sandwich G1-NITEGE(373 )ELISA (4) competition (374)ARGSV ELISA, and (5) sandwich (374)ARGSV-G2 ELISA all detecting aggrecan fragments, and (6) sandwich CTX-II ELISA, detecting C-telopeptides of type II collagen......- and aggrecanase-derived fragments of aggrecan and type II collagen into the supernatant of bovine cartilage explants cultures using neo-epitope specific immunoassays, and to associate the release of these fragments with the activity of proteolytic enzymes using inhibitors. FINDINGS: Bovine cartilage explants were....... We found that (1) aggrecanase-derived aggrecan fragments are released in the early (day 2-7) and mid phase (day 9-14) into the supernatant from bovine explants cultures stimulated with catabolic cytokines, (2) the release of NITEGE(373 )neo-epitopes are delayed compared to the corresponding (374...

  7. Exothermic Surface Reactions in Alumina-Aluminum Shell-Core Nanoparticles with Iodine Oxide Decomposition Fragments

    Science.gov (United States)

    2014-02-22

    aluminum and iodine pentoxide (I2O5) powder mixtures. Various equivalence ratios were examined and found to affect the PIR onset temperature. Prior to this...alumina– alumin Approved for public release; distribution is unlimited. 58857.45-EG REPORT DOCUMENTATION PAGE (SF298) (Continuation Sheet...and iodine pentoxide (I2O5) powder mixtures. Various equivalence ratios were examined and found to affect the PIR onset temper- ature. Prior to this

  8. Antihypertensive effects of continuous oral administration of nattokinase and its fragments in spontaneously hypertensive rats.

    Science.gov (United States)

    Fujita, Mitsugu; Ohnishi, Katsunori; Takaoka, Shinsaku; Ogasawara, Kazuya; Fukuyama, Ryo; Nakamuta, Hiromichi

    2011-01-01

    To determine whether the antihypertensive effect of nattokinase is associated with the protease activity of this enzyme, we compared nattokinase with the fragments derived from nattokinase, which possessed no protease activity, in terms of the effect on hypertension in spontaneously hypertensive rats (SHR). In the continuous oral administration test, the groups were given a basic diet alone (control), the basic diet containing nattokinase (0.2, 2.6 mg/g diet) or the basic diet containing the fragments derived from nattokinase (0.2, 0.6 mg/g diet). The group fed the basic diet containing high-dosage nattokinase (2.6 mg/g diet) showed significant reductions in systolic blood pressure (SBP), diastolic blood pressure (DBP) and plasma fibrinogen level, compared with control group and no influence on activities of renin and angiotensin-converting enzyme (ACE, EC 3.4.15.1), and plasma angiotensin II level in the renin-angiotensin system. The treatment of the basic diet containing high-dosage fragments (0.6 mg/g diet) significantly decreased SBP, DBP and plasma angiotensin II level in plasma but the treatment did not influence on plasma fibrinogen level. These results suggest that nattokinase and its fragments are different from each other in the mechanism to reduce hypertension. Nattokinase, retained its protease activity after absorbance across the intestines, may decrease blood pressure through cleavage of fibrinogen in plasma. The fragments, which absorbed as nattokinase-degradation products, prevents the elevation of plasma angiotensin II level to suppress hypertension.

  9. GREEN CORE HOUSE

    Directory of Open Access Journals (Sweden)

    NECULAI Oana

    2017-05-01

    Full Text Available The Green Core House is a construction concept with low environmental impact, having as main central element a greenhouse. The greenhouse has the innovative role to use the biomass energy provided by plants to save energy. Although it is the central piece, the greenhouse is not the most innovative part of the Green Core House, but the whole building ensemble because it integrates many other sustainable systems as "waste purification systems", "transparent photovoltaic panels" or "double skin façades".

  10. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  11. CORE COMPONENT POT

    Energy Technology Data Exchange (ETDEWEB)

    MARTIN RL; OMBERG RP

    1975-12-19

    The core component pot is an open top vessel used to hold both new and irradiated core components for storage in the IDS and for holding the components submerged in sodium while being trasported inside CLEM. The top of the CCP is equipped with a grapple lip which is engaged by the hoisting grapples. Heat for maintaining the preheat of new components and dissipation of decay heat of irradiated fuel assemblies is conducted between the wall of the pot and the surrounding environment by thermal radiation and convection.

  12. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is significantly ...

  13. Cores, Filaments, and Bundles: Hierarchical core formation in the B213 filament in Taurus

    Science.gov (United States)

    Hacar, Alvaro; Tafalla, Mario; Kauffmann, Jens; Kovacs, Attila

    2013-07-01

    Characterizing the dense core formation in filaments is a critical step for our understanding of the star formation process within molecular clouds. Using different molecular tracers to study the gas kinematics at different scales and density regimes, we have investigated the dense core formation in the B213/L1495 filament in Taurus, one of the most prominent structures identified in nearby clouds (see Hacar et al 2013, A&A, 554, A55). Our analysis of its internal kinematics demonstrates that this filament is actually a bundle of 35 velocity-coherent filaments, typically with lengths of ˜ 0.5 pc and oscillatory-like and sonic velocity field, each of them exhibiting linear masses close to the expected mass for a filament in hydrostatic equilibrium. Among them, only a small fraction of these filaments (˜1/4) are "fertile" and efficiently fragment forming all the cores identified within this region, while most of them (˜3/4) do not form cores and remain "sterile". Our observations then suggest that core formation in Taurus occurs in two steps. First, 0.5 pc-long velocity-coherent filaments condense out of the cloud gas, probably as a result of the turbulent cascade. After that, the dense cores condense quasi-statically in only those "fertile" filaments that have accumulated enough mass to became gravitational unstable, inheriting their kinematic properties. The formation of these velocity-coherent filaments appears therefore as a critical step on the star formation process being the first subsonic structures formed out of the turbulent regime that dominates the cloud dynamics at large scales.

  14. High Radiation Environment Nuclear Fragment Separator Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Stephen [Muons, Inc., Batavia, IL (United States); Gupta, Ramesh [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-01-31

    Superconducting coils wound with HTS conductor can be used in magnets located in a high radiation environment. NbTi and Nb3Sn superconductors must operate at 4.5 K or below where removal of heat is less efficient. The HTS conductor can carry significant current at higher temperatures where the Carnot efficiency is significantly more favorable and where the coolant heat capacity is much larger. Using the HTS conductor the magnet can be operated at 40 K. This project examines the use of HTS conductor for the Michigan State University Facility For Rare Isotope Beams (FRIB) fragment separator dipole magnet which bends the beam by 30° and is located in a high radiation region that will not be easily accessible. Two of these magnets are needed to select the chosen isotope. There are a number of technical challenges to be addressed in the design of this magnet. The separator dipole is 2 m long and subtends a large angle. The magnet should keep a constant transverse field profile along its beam reference path. Winding coils with a curved inner segment is difficult as the conductor will tend to unwind during the process. In the Phase I project two approaches to winding the conductor were examined. The first was to wind the coils with curved sections on the inner and outer segments with the inner segment wound with negative curvature. The alternate approach was to use a straight segment on the inner segment to avoid negative curvature. In Phase I coils with a limited number of turns were successfully wound and tested at 77 K for both coil configurations. The Phase II program concentrated on the design, coil winding procedures, structural analysis, prototyping and testing of an HTS curved dipole coil at 40 K with a heat load representative of the radiation environment. One of the key criteria of the design of this magnet is to avoid the use of organic materials that would degrade rapidly in radiation. The Lorentz forces expected from the coils interacting with the

  15. Molecular markers. Amplified fragment length polymorphism

    Directory of Open Access Journals (Sweden)

    Pržulj Novo

    2005-01-01

    Full Text Available Amplified Fragment Length Polymorphism molecular markers (AFLPs has been developed combining procedures of RFLPs and RAPDs molekular markers, i.e. the first step is restriction digestion of the genomic DNA that is followed by selective amplification of the restricted fragments. The advantage of the AFLP technique is that it allows rapid generation of a large number of reproducible markers. The reproducibility of AFLPs markers is assured by the use of restriction site-specific adapters and adapter-specific primers for PCR reaction. Only fragments containing the restriction site sequence plus the additional nucleotides will be amplified and the more selected nucleotides added on the primer sequence the fewer the number of fragments amplified by PCR. The amplified products are normally separated on a sequencing gel and visualized after exposure to X-ray film or by using fluorescent labeled primers. AFLP shave proven to be extremely proficient in revealing diversity at below the species level. A disadvantage of AFLP technique is that AFLPs are essentially a dominant marker system and not able to identify heterozygotes.

  16. Decentralized Development Planning and Fragmentation of ...

    African Journals Online (AJOL)

    of intense research and debate, especially in the developed world (Lewis, .... ple and lower units of government, leading to the fragmentation of government in a polity. In ... public services for the citizenry through competition, and improved political ..... Within the challenges of weak urban planning, poor management of land ...

  17. (DAD1) gene fragment of Chinese kale

    African Journals Online (AJOL)

    To clone the defective in anther dehiscence1 (DAD1) gene fragment of Chinese kale, about 700 bp product was obtained by PCR amplification using Chinese kale genomic DNA as the template and a pair of specific primers designed according to the conserved sequence of DAD1 genes of Arabidopsis thaliana and ...

  18. A note on convex renorming and fragmentability

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    A note on convex renorming and fragmentability. A K MIRMOSTAFAEE. Department of Mathematics, Damghan University of Sciences, P.O. 36715/364,. Damghan, Iran. E-mail: kmirmostafaee@dubs.ac.ir ... general, the domain of sn+1 consists of partial plays of the type. (A1,... ,Ai,Bi,Ai+1,... ,An+1), where, for every i ≤ n, (A1 ...

  19. The paradox of forest fragmentation genetics

    Science.gov (United States)

    Andrea T. Kramer; Jennifer L. Ison; Mary V. Ashley; Henry F. Howe

    2008-01-01

    Theory predicts widespread loss of genetic diversity from drift and inbreeding in trees subjected to habitat fragmentation, yet empirical support of this theory is scarce. We argue that population genetics theory may be misapplied in light of ecological realities that, when recognized, require scrutiny of underlying evolutionary assumptions. One ecological reality is...

  20. Fluorescent amplified fragment length polymorphism (AFLP ...

    African Journals Online (AJOL)

    Rosa rugosa is an excellent ornamental plant with important ecological, economical and medicinal values in China. Polymorphism amplifications of the genomic DNA of 5 wild R. rugosa accessions and 25 cultivars that originated from China with fluorescent amplified fragment length polymorphism molecular markers were ...

  1. Probabilistic Role Models and the Guarded Fragment

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2004-01-01

    We propose a uniform semantic framework for interpreting probabilistic concept subsumption and probabilistic role quantification through statistical sampling distributions. This general semantic principle serves as the foundation for the development of a probabilistic version of the guarded fragm...... fragment of first-order logic. A characterization of equivalence in that logic in terms of bisimulations is given....

  2. Probabilistic role models and the guarded fragment

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2006-01-01

    We propose a uniform semantic framework for interpreting probabilistic concept subsumption and probabilistic role quantification through statistical sampling distributions. This general semantic principle serves as the foundation for the development of a probabilistic version of the guarded fragm...... fragment of first-order logic. A characterization of equivalence in that logic in terms of bisimulations is given....

  3. Vocabularies Clashing: "The Fragmented Generation" Describes Itself

    Science.gov (United States)

    Collins, Daniel

    2011-01-01

    After reading Scott Seider and Howard Gardner's essay "The Fragmented Generation" (2009) in a college freshman writing class, students responded by providing their own labels for their generation. This article includes excerpts from their essays. Following these excerpts is the instructor's theoretical justification for this kind of classroom…

  4. Habitat fragmentation causes rapid genetic differentiation and ...

    African Journals Online (AJOL)

    ... city buildings. These results were supported by multiple statistical analyses including Mantel's test, PCOORDA and AMOVA. Genetic enrichment and epigenetic variation studies can be included in habitat fragmentation analysis and its implications in inducing homogenization and susceptibility in natural plant populations.

  5. Relationship between morphological and amplified fragment length ...

    African Journals Online (AJOL)

    ... morphological and amplified fragment length polymorphism (AFLP) marker based genetic diversity, to estimate mid parent heterosis and to correlate the estimated parental genetic diversity with heterosis chilli. Five CMS B - lines and 30 testers were used for morphological and AFLP marker genetic divergence analysis.

  6. Modified Fragmentation Function from Quark Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Majumder, A.; Wang, Enke; Wang, Xin-Nian

    2005-07-26

    Within the framework of the constituent quark model, it isshown that the single hadron fragmentation function of a parton can beexpressed as a convolution of shower diquark or triquark distributionfunction and quark recombination probability, if the interference betweenamplitudes of quark recombination with different momenta is neglected.Therecombination probability is determined by the hadron's wavefunction inthe constituent quark model. The shower diquark or triquark distributionfunctions of a fragmenting jet are defined in terms of overlappingmatrices of constituent quarks and parton field operators. They aresimilar in form to dihadron or trihadron fragmentation functions in termsof parton operator and hadron states. Extending the formalism to thefield theory at finite temperature, we automatically derive contributionsto the effective single hadron fragmentation function from therecombination of shower and thermal constituent quarks. Suchcontributions involve single or diquark distribution functions which inturn can be related to diquark or triquark distribution functions via sumrules. We also derive QCD evolution equations for quark distributionfunctions that in turn determine the evolution of the effective jetfragmentation functions in a thermal medium.

  7. Targeting incentives to reduce habitat fragmentation

    Science.gov (United States)

    David Lewis; Andrew Plantinga; Junjie Wu

    2009-01-01

    This article develops a theoretical model to analyze the spatial targeting of incentives for the restoration of forested landscapes when wildlife habitat can be enhanced by reducing fragmentation. The key theoretical result is that the marginal net benefits of increasing forest can be convex, in which case corner solutions--converting either none or all of the...

  8. Metagenome Fragment Classification Using -Mer Frequency Profiles

    Directory of Open Access Journals (Sweden)

    Gail Rosen

    2008-01-01

    Full Text Available A vast amount of microbial sequencing data is being generated through large-scale projects in ecology, agriculture, and human health. Efficient high-throughput methods are needed to analyze the mass amounts of metagenomic data, all DNA present in an environmental sample. A major obstacle in metagenomics is the inability to obtain accuracy using technology that yields short reads. We construct the unique -mer frequency profiles of 635 microbial genomes publicly available as of February 2008. These profiles are used to train a naive Bayes classifier (NBC that can be used to identify the genome of any fragment. We show that our method is comparable to BLAST for small 25 bp fragments but does not have the ambiguity of BLAST's tied top scores. We demonstrate that this approach is scalable to identify any fragment from hundreds of genomes. It also performs quite well at the strain, species, and genera levels and achieves strain resolution despite classifying ubiquitous genomic fragments (gene and nongene regions. Cross-validation analysis demonstrates that species-accuracy achieves 90% for highly-represented species containing an average of 8 strains. We demonstrate that such a tool can be used on the Sargasso Sea dataset, and our analysis shows that NBC can be further enhanced.

  9. RESPONSE TO "THE OPTIMAL FRAGMENTATION PRINCIPLE".

    Science.gov (United States)

    Response to "The Optimal Fragmentation Principle"To follow up on my comment to Dale Johnson and to respond to his entertaining and provocative letter, I confess to some frustration in seeing a show-and-tell of a sophisticated tool for data mining and exploration, without ...

  10. Habitat fragmentation causes rapid genetic differentiation and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... 1Laboratory of Plant Molecular Epigenetics, Institute of Genetics and Cytology, Northeast Normal University, Changchun. 130024 ... epigenetic variation studies can be included in habitat fragmentation analysis and its implications in inducing ... together with the environment habitat selection pressure.

  11. Distribution and Causes of Global Forest Fragmentation

    Directory of Open Access Journals (Sweden)

    Timothy G. Wade

    2003-12-01

    Full Text Available Because human land uses tend to expand over time, forests that share a high proportion of their borders with anthropogenic uses are at higher risk of further degradation than forests that share a high proportion of their borders with non-forest, natural land cover (e.g., wetland. Using 1-km advanced very high resolution radiometer (AVHRR satellite-based land cover, we present a method to separate forest fragmentation into natural and anthropogenic components, and report results for all inhabited continents summarized by World Wildlife Fund biomes. Globally, over half of the temperate broadleaf and mixed forest biome and nearly one quarter of the tropical rainforest biome have been fragmented or removed by humans, as opposed to only 4% of the boreal forest. Overall, Europe had the most human-caused fragmentation and South America the least. This method may allow for improved risk assessments and better targeting for protection and remediation by identifying areas with high amounts of human-caused fragmentation.

  12. The St Marys fragmentation grenade explosion.

    Science.gov (United States)

    Nocera, A

    1997-05-19

    The accidental explosion of a fragmentation grenade in a munitions factory at St Marys injured four workers, two critically. The prompt response by ambulances and physician-staffed helicopter emergency medical service prevented deaths, but the incident suggests lessons for the future handling of urban explosions.

  13. Fragmentation of forest, grassland, and shrubland

    Science.gov (United States)

    Kurt H. Riitters

    2013-01-01

    As humans introduce competing land uses into natural landscapes, the public concerns regarding landcover patterns are expressed through headline issues such as urban sprawl, forest fragmentation, water quality, and wilderness preservation. The spatial arrangement of an environment affects all human perceptions and ecological processes within that environment, but this...

  14. Element Distribution and Multiplicity of Heavy Fragments

    CERN Multimedia

    2002-01-01

    This experiment will measure the energy and angular distribution of heavy fragments produced in the reactions of |1|2C on several targets between |2|7Al and |2|3|8U at 86~MeV/u. The systematic investigation of a highly excited interaction region (fireball) by means of a clean N and Z identification of heavy tar fragments, may result in a better understanding of temperature concept and of the degree of equilibration of the local interaction region with respect to the total system. For this investigation a large-area position sensitive ionization chamber of 50~msr solid angle in conjunction with a time-of-flight telescope consisting of parallel-plate detectors will be used. \\\\ \\\\ In order to get information on the transverse momentum transfer and the inelasticity of the collision, the energy of the PROJECTILE-FRAGMENTS will be measured at forward angles with a plastic scintillator hodoscope. In addition to this inclusive measurement correlations between heavy fragments will be investigated by means of three pos...

  15. Fragment size distribution statistics in dynamic fragmentation of laser shock-loaded tin

    Directory of Open Access Journals (Sweden)

    Weihua He

    2017-06-01

    Full Text Available This work investigates the geometric statistics method to characterize the size distribution of tin fragments produced in the laser shock-loaded dynamic fragmentation process. In the shock experiments, the ejection of the tin sample with etched V-shape groove in the free surface are collected by the soft recovery technique. Subsequently, the produced fragments are automatically detected with the fine post-shot analysis techniques including the X-ray micro-tomography and the improved watershed method. To characterize the size distributions of the fragments, a theoretical random geometric statistics model based on Poisson mixtures is derived for dynamic heterogeneous fragmentation problem, which reveals linear combinational exponential distribution. The experimental data related to fragment size distributions of the laser shock-loaded tin sample are examined with the proposed theoretical model, and its fitting performance is compared with that of other state-of-the-art fragment size distribution models. The comparison results prove that our proposed model can provide far more reasonable fitting result for the laser shock-loaded tin.

  16. Copper (II)

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    ABSTRACT: A Schiff base was prepared from the reaction of 2 - amino - 3 – methylbutanoic acid and 2, 4 - pentanedione. The reaction of the prepared Schiff base with ethanolic solution of copper (II) chloride formed diaquo bis( N – 2 – amino – 3 - methylbutyl - 2, 4 - pentanedionato) copper (II) complex. The Schiff base is ...

  17. Inflation targeting and core inflation

    OpenAIRE

    Julie Smith

    2005-01-01

    This paper examines the interaction of core inflation and inflation targeting as a monetary policy regime. Interest in core inflation has grown because of inflation targeting. Core inflation is defined in numerous ways giving rise to many potential measures; this paper defines core inflation as the best forecaster of inflation. A cross-country study finds before the start of inflation targeting, but not after, core inflation differs between non-inflation targeters and inflation targeters. Thr...

  18. NUCLEAR REACTOR CORE DESIGN

    Science.gov (United States)

    Mahlmeister, J.E.; Peck, W.S.; Haberer, W.V.; Williams, A.C.

    1960-03-22

    An improved core design for a sodium-cooled, graphitemoderated nuclear reactor is described. The improved reactor core comprises a number of blocks of moderator material, each block being in the shape of a regular prism. A number of channels, extending the length of each block, are disposed around the periphery. When several blocks are placed in contact to form the reactor core, the channels in adjacent blocks correspond with each other to form closed conduits extending the length of the core. Fuel element clusters are disposed in these closed conduits, and liquid coolant is forced through the annulus between the fuel cluster and the inner surface of the conduit. In a preferred embodiment of the invention, the moderator blocks are in the form of hexagonal prisms with longitudinal channels cut into the corners of the hexagon. The main advantage of an "edge-loaded" moderator block is that fewer thermal neutrons are absorbed by the moderator cladding, as compared with a conventional centrally loaded moderator block.

  19. Schumpeter's core works revisited

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2012-01-01

    This paper organises Schumpeter’s core books in three groups: the programmatic duology,the evolutionaryeconomic duology,and the socioeconomic synthesis. By analysing these groups and their interconnections from the viewpoint of modern evolutionaryeconomics,the paper summarises resolved problems...

  20. Core Obstetrics and Gynaecology*

    African Journals Online (AJOL)

    Core Obstetrics and Gynaecology*. By J. T. Nel. Pp xvii + 992. Illustrated. Durban: Butterworths. 1995. ISBN 0-409-10134-6. For some years now, I have lamented the absence of a good, home-grown, comprehensive, student-centred textbook of obstetrics and gynaecology designed specifically for South African needs.

  1. Adult educators' core competences

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    2016-01-01

    environment as well as the kind of adult education concerned (e.g. basic education, work-related education etc.). However, it seems that it is possible to identify certain competence requirements which transcend national, cultural and functional boundaries. This research note summarises these common or “core...

  2. The core and cosmopolitans

    DEFF Research Database (Denmark)

    Dahlander, Linus; Frederiksen, Lars

    2012-01-01

    Users often interact and help each other solve problems in communities, but few scholars have explored how these relationships provide opportunities to innovate. We analyze the extent to which people positioned within the core of a community as well as people that are cosmopolitans positioned...

  3. Looking for Core Values

    Science.gov (United States)

    Carter, Margie

    2010-01-01

    People who view themselves as leaders, not just managers or teachers, are innovators who focus on clarifying core values and aligning all aspects of the organization with these values to grow their vision. A vision for an organization can't be just one person's idea. Visions grow by involving people in activities that help them name and create…

  4. Some Core Contested Concepts

    Science.gov (United States)

    Chomsky, Noam

    2015-01-01

    Core concepts of language are highly contested. In some cases this is legitimate: real empirical and conceptual issues arise. In other cases, it seems that controversies are based on misunderstanding. A number of crucial cases are reviewed, and an approach to language is outlined that appears to have strong conceptual and empirical motivation, and…

  5. Modeling Core Collapse Supernovae

    Science.gov (United States)

    Mezzacappa, Anthony

    2017-01-01

    Core collapse supernovae, or the death throes of massive stars, are general relativistic, neutrino-magneto-hydrodynamic events. The core collapse supernova mechanism is still not in hand, though key components have been illuminated, and the potential for multiple mechanisms for different progenitors exists. Core collapse supernovae are the single most important source of elements in the Universe, and serve other critical roles in galactic chemical and thermal evolution, the birth of neutron stars, pulsars, and stellar mass black holes, the production of a subclass of gamma-ray bursts, and as potential cosmic laboratories for fundamental nuclear and particle physics. Given this, the so called ``supernova problem'' is one of the most important unsolved problems in astrophysics. It has been fifty years since the first numerical simulations of core collapse supernovae were performed. Progress in the past decade, and especially within the past five years, has been exponential, yet much work remains. Spherically symmetric simulations over nearly four decades laid the foundation for this progress. Two-dimensional modeling that assumes axial symmetry is maturing. And three-dimensional modeling, while in its infancy, has begun in earnest. I will present some of the recent work from the ``Oak Ridge'' group, and will discuss this work in the context of the broader work by other researchers in the field. I will then point to future requirements and challenges. Connections with other experimental, observational, and theoretical efforts will be discussed, as well.

  6. Core calculations of JMTR

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Yoshiharu [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    In material testing reactors like the JMTR (Japan Material Testing Reactor) of 50 MW in Japan Atomic Energy Research Institute, the neutron flux and neutron energy spectra of irradiated samples show complex distributions. It is necessary to assess the neutron flux and neutron energy spectra of an irradiation field by carrying out the nuclear calculation of the core for every operation cycle. In order to advance core calculation, in the JMTR, the application of MCNP to the assessment of core reactivity and neutron flux and spectra has been investigated. In this study, in order to reduce the time for calculation and variance, the comparison of the results of the calculations by the use of K code and fixed source and the use of Weight Window were investigated. As to the calculation method, the modeling of the total JMTR core, the conditions for calculation and the adopted variance reduction technique are explained. The results of calculation are shown. Significant difference was not observed in the results of neutron flux calculations according to the difference of the modeling of fuel region in the calculations by K code and fixed source. The method of assessing the results of neutron flux calculation is described. (K.I.)

  7. The Uncommon Core

    Science.gov (United States)

    Ohler, Jason

    2013-01-01

    This author contends that the United States neglects creativity in its education system. To see this, he states, one may look at the Common Core State Standards. If one searches the English Language Arts and Literacy standards for the words "creative," "innovative," and "original"--and any associated terms, one will…

  8. Keratocyte fragments and cells utilize competing pathways to move in opposite directions in an electric field.

    Science.gov (United States)

    Sun, Yaohui; Do, Hao; Gao, Jing; Zhao, Ren; Zhao, Min; Mogilner, Alex

    2013-04-08

    Sensing of an electric field (EF) by cells-galvanotaxis-is important in wound healing [1], development [2], cell division, nerve growth, and angiogenesis [3]. Different cell types migrate in opposite directions in EFs [4], and the same cell can switch the directionality depending on conditions [5]. A tug-of-war mechanism between multiple signaling pathways [6] can direct Dictyostelium cells to either cathode or anode. Mechanics of motility is simplest in fish keratocytes, so we turned to keratocytes to investigate their migration in EFs. Keratocytes sense electric fields and migrate to the cathode [7, 8]. Keratocyte fragments [9, 10] are the simplest motile units. Cell fragments from leukocytes are able to respond to chemotactic signals [11], but whether cell fragments are galvanotactic was unknown. We found that keratocyte fragments are the smallest motile electric field-sensing unit: they migrate to the anode, in the opposite direction of whole cells. Myosin II was essential for the direction sensing of fragments but not for parental cells, while PI3 kinase was essential for the direction sensing of whole cells but not for fragments. Thus, two signal transduction pathways, one depending on PI3K, another on myosin, compete to orient motile cells in the electric field. Galvanotaxis is not due to EF force and does not depend on cell or fragment size. We propose a "compass" model according to which protrusive and contractile actomyosin networks self-polarize to the front and rear of the motile cell, respectively, and the electric signal orients both networks toward cathode with different strengths. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Restriction fragment polymorphisms in the major histocompatibility complex of diabetic BB rats

    DEFF Research Database (Denmark)

    Kastern, W.; Dyrberg, T.; Scholler, J.

    1984-01-01

    DNA isolated from diabetic BB (BB/Hagedorn) rats was examined for restriction fragment length differences within the major histocompatibility complex (MHC) as compared with nondiabetic (W-subline) BB rats. Polymorphisms were detected using a mouse class I MHC gene as probe. Specifically, a 2-kb Bam......) or a human DC-beta (class II antigen light chain) gene as probes. These results indicate that the BB rat diabetic syndrome may be linked to differences in class I MHC genes....

  10. Genotyping and genetic diversity of Arcobacter butzleri by amplified fragment length polymorphism (AFLP) analysis

    DEFF Research Database (Denmark)

    On, Stephen L.W.; Atabay, H.I.; Amisu, K.O.

    2004-01-01

    American origin from human infections, chickens, turkeys, ducks, sheep and poultry abbatoir effluent were studied by use of a protocol that involved stringent PCR amplification of fragments derived from digestion of genomic DNA with restriction enzymes BglII and Csp6I. The mean similarity value...... for molecular epidemiological studies of this ubiquitous emerging pathogen that is implicated as a causative agent of both human and animal disease....

  11. Analysis of Fragmentation and Resulting Shrapnel Penetration of Naturally Fragmenting Cylindrical Bombs

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, S.E.

    2000-08-01

    Fragmentation of exploding cylinders and penetration mechanics of surrounding vessel walls were examined and a qualitative understanding was achieved. This understanding provided a basis for making simplifying approximations and assumptions that aided in creating a shrapnel penetration model. Several mathematical models were discussed, and results from 6 cylinder tests were analyzed in order to select a model that best represented the data. It was determined that the overall best mathematical model to predict shrapnel penetration uses the modified Gurney equation to calculate fragment velocity, the Mott equation to calculate largest fragment weight, and the Christman/Gehring equation to calculate penetration depth.

  12. What is the usefulness of the fragmentation pattern of the femoral head in managing Legg-Calvé-Perthes disease?

    Science.gov (United States)

    Kim, Hui Taek; Woo, Seung Hun; Jang, Jae Hoon; Lee, Seung Geun; Kim, Harry K W; Browne, Richard

    2014-06-01

    Within the lateral pillar classification of the Legg-Calvé-Perthes (LCP) disease, hips seem quite variable in the pattern of fragmentation as seen in radiographs. The purpose of this study was to determine: if it is possible to reliably subdivide the lateral pillar groups into femoral head fragmentation patterns, and if such a subdivision of the lateral pillar groupings is clinically useful in managing LCP disease. Two hundred and ninety-three anteroposterior radiographs taken at the maximal fragmentation stage (189 lateral pillar B, 57 B/C border, and 47 C hips; mean bone/chronologic age at the time of first visit, 6.2/7.9 years) and at skeletal maturity (mean age, 16.6 years) were analyzed. We distinguished 3 fragmentation patterns in each pillar group based on the region of major involvement. We tested the inter- and intraobserver reliability of our classification system and analyzed the relationships between the fragmentation patterns and the Stulberg outcomes as well as other factors such as surgical treatment and age. Inter- and intraobserver consistency in fragmentation pattern assignments was found to be substantial to excellent. A statistically significant trend (p = 0.001) in the proportion of Stulberg III or IV outcomes in comparison with Stulberg I and II was only found for the different fragmentation patterns in our lateral pillar B patients: fragmentation patterns having mainly lateral-central necrosis led to poor outcomes. No significant association was found between fragmentation patterns and Stulberg outcomes in pillar groups B/C border and C. Our results are consistent with the lateral pillar classification itself. Therefore, fragmentation patterns in each lateral pillar classification did not provide clinical usefulness in the management of LCP disease.

  13. Sustained sleep fragmentation induces sleep homeostasis in mice

    KAUST Repository

    Baud, Maxime O.

    2015-04-01

    Study Objectives: Sleep fragmentation (SF) is an integral feature of sleep apnea and other prevalent sleep disorders. Although the effect of repetitive arousals on cognitive performance is well documented, the effects of long-term SF on electroencephalography (EEG) and molecular markers of sleep homeostasis remain poorly investigated. To address this question, we developed a mouse model of chronic SF and characterized its effect on EEG spectral frequencies and the expression of genes previously linked to sleep homeostasis including clock genes, heat shock proteins, and plasticity-related genes. Design: N/A. Setting: Animal sleep research laboratory. Participants : Sixty-six C57BL6/J adult mice. Interventions: Instrumental sleep disruption at a rate of 60/h during 14 days Measurements and Results: Locomotor activity and EEG were recorded during 14 days of SF followed by recovery for 2 days. Despite a dramatic number of arousals and decreased sleep bout duration, SF minimally reduced total quantity of sleep and did not significantly alter its circadian distribution. Spectral analysis during SF revealed a homeostatic drive for slow wave activity (SWA; 1-4 Hz) and other frequencies as well (4-40 Hz). Recordings during recovery revealed slow wave sleep consolidation and a transient rebound in SWA, and paradoxical sleep duration. The expression of selected genes was not induced following chronic SF. Conclusions: Chronic sleep fragmentation (SF) increased sleep pressure confirming that altered quality with preserved quantity triggers core sleep homeostasis mechanisms. However, it did not induce the expression of genes induced by sleep loss, suggesting that these molecular pathways are not sustainably activated in chronic diseases involving SF.

  14. Melt Fragmentation Characteristics of Metal Fuel with Melt Injection Mass during Initiating Phase of SFR Severe Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Hyo; Lee, Min Ho; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Jerng, Dong Wook [Chung-Ang Univ., Seoul (Korea, Republic of)

    2016-05-15

    The PGSFR has adopted the metal fuel for its inherent safety under severe accident conditions. However, this fuel type is not demonstrated clearly yet under the such severe accident conditions. Additional experiments for examining these issues should be performed to support its licensing activities. Under initiating phase of hypothetic core disruptive accident (HCDA) conditions, the molten metal could be better dispersed and fragmented into the coolant channel than in the case of using oxide fuel. This safety strategy provides negative reactivity driven by a good dispersion of melt. If the coolant channel does not sufficient coolability, the severe recriticality would occur within the core region. Thus, it is important to examine the extent of melt fragmentation. The fragmentation behaviors of melt are closely related to a formation of debris shape. Once the debris shape is formed through the fragmentation process, its coolability is determined by the porosity or thermal conductivity of the melt. There were very limited studies for transient irradiation experiments of the metal fuel. These studies were performed by Transient Reactor Test Facility (TREAT) M series tests in U.S. The TREAT M series tests provided basic information of metal fuel performance under transient conditions. The effect of melt injection mass was evaluated in terms of the fragmentation behaviors of melt. These behaviors seemed to be similar between single-pin and multi-pins failure condition. However, the more melt was agglomerated in case of multi-pins failure.

  15. Population Genetic Structure of Glycyrrhiza inflata B. (Fabaceae) Is Shaped by Habitat Fragmentation, Water Resources and Biological Characteristics.

    Science.gov (United States)

    Yang, Lulu; Chen, Jianjun; Hu, Weiming; Yang, Tianshun; Zhang, Yanjun; Yukiyoshi, Tamura; Zhou, Yanyang; Wang, Ying

    2016-01-01

    Habitat fragmentation, water resources and biological characteristics are important factors that shape the genetic structure and geographical distribution of desert plants. Analysis of the relationships between these factors and population genetic variation should help to determine the evolutionary potential and conservation strategies for genetic resources for desert plant populations. As a traditional Chinese herb, Glycyrrhiza inflata B. (Fabaceae) is restricted to the fragmented desert habitat in China and has undergone a dramatic decline due to long-term over-excavation. Determining the genetic structure of the G. inflata population and identifying a core collection could help with the development of strategies to conserve this species. We investigated the genetic variation of 25 G. inflata populations based on microsatellite markers. A high level of population genetic divergence (FST = 0.257), population bottlenecks, reduced gene flow and moderate genetic variation (HE = 0.383) were detected. The genetic distances between the populations significantly correlated with the geographical distances, and this suggests that habitat fragmentation has driven a special genetic structure of G. inflata in China through isolation by distance. STRUCTURE analysis showed that G. inflata populations were structured into three clusters and that the populations belonged to multiple water systems, which suggests that water resources were related to the genetic structure of G. inflata. In addition, the biological characteristics of the perennial species G. inflata, such as its long-lived seeds, asexual reproduction, and oasis ecology, may be related to its resistance to habitat fragmentation. A core collection of G. inflata, that included 57 accessions was further identified, which captured the main allelic diversity of G. inflata. Recent habitat fragmentation has accelerated genetic divergence. The population genetic structure of G. inflata has been shaped by habitat

  16. Mapping permanent preservation areas and natural forest fragments as subsidy to the registration of legal reserve areas in rural properties

    Directory of Open Access Journals (Sweden)

    Vicente Paulo Soares

    2011-12-01

    Full Text Available The major objective of this work was to identify and quantify forest fragments suitable to be used as private protected land in rural properties located in the São Bartolomeu creek watershed, State of Minas Gerais, Brazil. The methodological procedures included: mapping of 78 forest fragments through the visual interpretation of an Ikonos II satellite image; delineation of Permanent Preservation Areas (PPAs from a hydrographically conditioned digital elevation model and mapping of 292 rural properties through interviews with owners, with the aid of a printed Ikonos II image. The generated maps were overlapped (crossed, allowing the identification of forest fragments that could be used as private protected land in rural property. The result indicated that, from the total of properties evaluated, only 41 (14.04% have more than 20% of forest cover, and therefore, are in condition to attend the environmental law for private protected land.

  17. Assessment and monitoring of deforestation and forest fragmentation in South Asia since the 1930s

    Science.gov (United States)

    Sudhakar Reddy, C.; Saranya, K. R. L.; Vazeed Pasha, S.; Satish, K. V.; Jha, C. S.; Diwakar, P. G.; Dadhwal, V. K.; Rao, P. V. N.; Krishna Murthy, Y. V. N.

    2018-02-01

    The present study, first of its kind, has analyzed the land cover and investigated the spatial patterns of deforestation and forest fragmentation in South Asian region since the 1930's. This region comprises of eight countries: India, Bangladesh, Bhutan, Nepal, Pakistan, Afghanistan, Sri Lanka and Maldives. In South Asia, agricultural land is predominant constituting 43% of the total geographical area followed by barren land (19.99%) and forests (14.72%). The long-term change analysis using the classified maps of 1930 and 2014 indicated a loss of 29.62% of the forest cover. Higher annual net deforestation rates were observed in the period from 1930-1975 (0.68%) followed by 1975-1985 (0.23%), 1985-1995 (0.12%), 1995-2005 (0.06%) and 2005-2014 (0.04%) for the region. Forest fragmentation had significant spatio-temporal variation across the South Asian countries. In 1930, 88.91% of the South Asian forest was classified as large core forest, 8.18% as edge forest and 1.18% as perforated forest. The large core forest category has decreased significantly in area over last eight decades. The results of the present study are expected to serve as a reference for the evaluation of globally agreed Aichi biodiversity target 5 for South Asian countries. This study will be a valuable basis for developing management strategies and restoration programs as it tracks the spatial changes in deforestation and forest fragmentation.

  18. Development of full MOX core in ABWR

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, Motoo; Uchikawa, Sadao; Izutsu, Sadayuki; Sasagawa, Masaru; Kaneto, Kunikazu [Hitachi Ltd., Tokyo (Japan)

    1996-10-01

    The feasibility and performance evaluations of the full mixed-oxide (MOX) core in the Advanced BWR (ABWR) were shown as part of the full scale utilization study of MOX fuel. Core design for the ABWR of 3926 MWt with MOX fuel bundles, which have an identical configuration to the STEP II fuel design, was performed from initial to equilibrium cycles. The operating cycle length is 13 months and the discharge exposure for MOX fuel bundles is about 33 GWd/t. In the equilibrium cycle, about one third of the fuel bundles are replaced by reload fresh MOX fuel bundles at the beginning of cycle. The amount of loaded fissile plutonium (Puf) is about 1.4 tons which is equivalent to about 1.1 tons/year. In the initial cycle, the fraction of loaded MOX fuel bundles is about 30%, and the remainder consists of two UO{sub 2} fuel bundle types with different enrichments. In the second and third cycles, about one third of the fuel bundles are replaced by reload fresh MOX fuel bundles at the beginning of each cycle. As a result, the third cycle becomes the full MOX core, and the amount of fissile plutonium loaded for each cycle is about 1.4 - 1.5 tons. Core performance was shown to meet the design criteria. (author)

  19. The Impact of Dark and Visible Fragmentation on Market Quality (Replaced by EBC Discussion Paper 2011-016)

    NARCIS (Netherlands)

    Degryse, H.A.; de Jong, F.C.J.M.; van Kervel, V.L.

    2011-01-01

    Two important characteristics of current European equity markets are rooted in changes in financial regulation (the Markets in Financial Instruments Directive). The regulation (i) allows new trading venues to emerge, generating a fragmented market place and (ii) allows for a substantial fraction of

  20. The Impact of Dark and Visible Fragmentation on Market Quality (Replaced by CentER DP 2011-069)

    NARCIS (Netherlands)

    Degryse, H.A.; de Jong, F.C.J.M.; van Kervel, V.L.

    2011-01-01

    Two important characteristics of current European equity markets are rooted in changes in financial regulation (the Markets in Financial Instruments Directive). The regulation (i) allows new trading venues to emerge, generating a fragmented market place and (ii) allows for a substantial fraction of

  1. The Impact of Dark and Visible Fragmentation on Market Quality (Replaces CentER Discussion Paper 2011-051)

    NARCIS (Netherlands)

    Degryse, H.A.; de Jong, F.C.J.M.; van Kervel, V.L.

    2011-01-01

    Two important characteristics of current European equity markets are rooted in changes in financial regulation (the Markets in Financial Instruments Directive). The regulation (i) allows new trading venues to emerge, generating a fragmented market place and (ii) allows for a substantial fraction of

  2. The Impact of Dark and Visible Fragmentation on Market Quality (Replaces EBC Discussion Paper 2011-013)

    NARCIS (Netherlands)

    Degryse, H.A.; de Jong, F.C.J.M.; van Kervel, V.L.

    2011-01-01

    Two important characteristics of current European equity markets are rooted in changes in financial regulation (the Markets in Financial Instruments Directive). The regulation (i) allows new trading venues to emerge, generating a fragmented market place and (ii) allows for a substantial fraction of

  3. The Importance of Three-Body Interactions in Molecular Dynamics Simulations of Water with the Fragment Molecular Orbital Method

    Energy Technology Data Exchange (ETDEWEB)

    Pruitt, Spencer R.; Nakata, Hiroya; Nagata, Takeshi; Mayes, Maricris; Alexeev, Yuri; Fletcher, Graham D.; Fedorov, Dmitri G; Kitaura, Kazuo; Gordon, M

    2016-04-12

    The analytic first derivative with respect to nuclear coordinates is formulated and implemented in the framework of the three-body fragment molecular orbital (FMO) method. The gradient has been derived and implemented for restricted Hartree-Fock, second-order Møller-Plesset perturbation, and density functional theories. The importance of the three-body fully analytic gradient is illustrated through the failure of the two-body FMO method during molecular dynamics simulations of a small water cluster. The parallel implementation of the fragment molecular orbital method, its parallel efficiency, and its scalability on the Blue Gene/Q architecture up to 262,144 CPU cores, are also discussed.

  4. Percentile Fragment Size Predictions for Blasted Rock and the Fragmentation-Energy Fan

    Science.gov (United States)

    Ouchterlony, Finn; Sanchidrián, José A.; Moser, Peter

    2017-04-01

    It is shown that blast fragmentation data in the form of sets of percentile fragment sizes, x P, as function of specific charge (powder factor, q) often form a set of straight lines in a log( x P) versus log( q) diagram that tend to converge on a common focal point. This is clear for single-hole shots with normal specific charge values in specimens of virgin material, and the phenomenon is called the fragmentation-energy fan. Field data from bench blasting with several holes in single or multiple rows in rock give data that scatter much more, but examples show that the fragmentation data tend to form such fans. The fan behavior implies that the slopes of the straight size versus specific charge lines in log-log space depend only on the percentile level in a given test setup. It is shown that this property can be derived for size distribution functions of the form P[ln( x max/ x)/ln( x max/ x 50)]. An example is the Swebrec function; for it to comply with the fragmentation-energy fan properties, the undulation parameter b must be constant. The existence of the fragmentation-energy fan contradicts two basic assumptions of the Kuz-Ram model: (1) that the Rosin-Rammler function reproduces the sieving data well and (2) that the uniformity index n is a constant, independent of q. This favors formulating the prediction formulas instead in terms of the percentile fragment size x P for arbitrary P values, parameters that by definition are independent of any size distribution, be it the Rosin-Rammler, Swebrec or other. A generalization of the fan behavior to include non-dimensional fragment sizes and an energy term with explicit size dependence seems possible to make.

  5. Measuring core stability.

    Science.gov (United States)

    Liemohn, Wendell P; Baumgartner, Ted A; Gagnon, Laura H

    2005-08-01

    In this study, a 4-item battery of core stability (CS) tests modeled on core stabilization activities used in training and rehabilitation research was developed, and a measurement schedule was established to maximize internal consistency and stability reliabilities. Specifically, we found that 4 test administrations on each of 4 days produced intraclass correlation coefficients that in most instances exceeded 0.90 and stability reliability coefficients on the third and fourth days of testing that exceeded 0.90 for 2 of the tests and 0.80 for the other 2. Thus, it is recommended that in future research, examiners administer the battery for at least 3 days and consider the data collected on day 3 as the best estimate of participant CS.

  6. Core Outlet Temperature Study

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A. [Argonne National Laboratory (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Laboratory (ANL), Argonne, IL (United States); Majumdar, S. [Argonne National Laboratory (ANL), Argonne, IL (United States)

    2008-07-28

    It is a known fact that the power conversion plant efficiency increases with elevation of the heat addition temperature. The higher efficiency means better utilization of the available resources such that higher output in terms of electricity production can be achieved for the same size and power of the reactor core or, alternatively, a lower power core could be used to produce the same electrical output. Since any nuclear power plant, such as the Advanced Burner Reactor, is ultimately built to produce electricity, a higher electrical output is always desirable. However, the benefits of the higher efficiency and electricity production usually come at a price. Both the benefits and the disadvantages of higher reactor outlet temperatures are analyzed in this work.

  7. Fragmentation model for large L/D (Length over Diameter explosive fragmentation warheads

    Directory of Open Access Journals (Sweden)

    Vladimir M. Gold

    2017-08-01

    Full Text Available New advanced numerical computer model enabling accurate simulation of fragmentation parameters of large Length over Diameter (L/D explosively driven metal shells has been developed and validated. The newly developed large L/D multi-region model links three-dimensional axisymmetric high strain high strain-rate hydrocode analyses with the conventional set of Picatinny Arsenal FRAGmentation (PAFRAG simulation routines. The standard PAFRAG modeling technique is based on the Mott's theory of break-up of idealized cylindrical “ring-bombs”, in which the length of the average fragment is a function of the radius and velocity of the shell at the moment of break-up, and the mechanical properties of the metal. In the newly developed multi-region model, each of the shell region, the break-up is assumed to occur instantaneously, whereas the entire shell is modeled to fragment at multiple times, according to the number of the regions considered. According to PAFRAG methodology, the required input for both the natural and the controlled fragmentation models including the geometry and the velocity of the shell at moment of break-up had been provided from the hydrocode analyses and validated with available experimental data. The newly developed large L/D multi-region PAFRAG model has been shown to accurately reproduce available experimental fragmentation data.

  8. Ice Cores of the National Ice Core Laboratory

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. National Ice Core Laboratory (NICL) is a facility for storing, curating, and studying ice cores recovered from the polar regions of the world. It provides...

  9. Core Exercises: Why You Should Strengthen Your Core Muscles

    Science.gov (United States)

    ... neglected. Still, it pays to get your core muscles — the muscles around your trunk and pelvis — in better shape. ... to find out why. Core exercises train the muscles in your pelvis, lower back, hips and abdomen ...

  10. USGS Core Research Center (CRC) Collection of Core

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Core Research Center (CRC) was established in 1974 by the U.S. Geological Survey (USGS) to preserve valuable rock cores for use by scientists and educators from...

  11. Leadership Core Competencies

    Science.gov (United States)

    2008-03-15

    different approaches led to a very similar understanding of what is required to develop leaders and achieve mission success. LEADERSHIP CORE... Leadership , the first principle, Know yourself and seek self-improvement performs the same function. Similar to the other services, Navy leaders evaluate... leadership styles. Like managers of today, those of tomorrow will also need to do more with less. They will have increased responsibilities and will

  12. Core Support to Global Development Network (GND) - Phase II ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... Entrepreneurship Program : Massachusetts Institute of Technology. The Developmental Entrepreneurship Program at the Massachusetts Institute of Technology (MIT) helps researchers, students and practitioner from developing countries to investigate private-sector... View moreDevelopmental Entrepreneurship Program ...

  13. On the Expressive Power of Sub-Propositional Fragments of Modal Logic

    Directory of Open Access Journals (Sweden)

    Davide Bresolin

    2016-09-01

    Full Text Available Modal logic is a paradigm for several useful and applicable formal systems in computer science. It generally retains the low complexity of classical propositional logic, but notable exceptions exist in the domains of description, temporal, and spatial logic, where the most expressive formalisms have a very high complexity or are even undecidable. In search of computationally well-behaved fragments, clausal forms and other sub-propositional restrictions of temporal and description logics have been recently studied. This renewed interest on sub-propositional logics, which mainly focus on the complexity of the various fragments, raise natural questions on their the relative expressive power, which we try to answer here for the basic multi-modal logic Kn. We consider the Horn and the Krom restrictions, as well as the combined restriction (known as the core fragment of modal logic, and, orthogonally, the fragments that emerge by disallowing boxes or diamonds from positive literals. We study the problem in a very general setting, to ease transferring our results to other meaningful cases.

  14. Habitat fragmentation effects on biodiversity patterns

    Science.gov (United States)

    Conceição, Katiane S.; de Oliveira, Viviane M.

    2010-09-01

    We study the effects of habitat fragmentation on biodiversity patterns by means of a simple spatial model which considers selective geographic colonization, diffusion and mutation. In our model, regions of the lattice are characterized by the amount of resources available to populations of species which are going to colonize that regions. We simulate the fragmentation of the habitat by assuming that a proportion p of the sites is not available for colonization, that is, there is no resource availability in those sites. We analyse the patterns of the species-area relationship and the abundance distribution considering two sample methods, in order to simulate the cases in which the habitats are distributed in islands and continents. We have observed that the pattern of the species-area curve is changed when different sample methods are considered. We have also verified that the abundance distribution is bimodal when small mutation probabilities are considered.

  15. Fission fragment distributions within dynamical approach

    Science.gov (United States)

    Mazurek, K.; Nadtochy, P. N.; Ryabov, E. G.; Adeev, G. D.

    2017-04-01

    The review covers recent developments and achievements in the dynamical description of fission process at high excitation energy. It is shown that the dynamical approach based on multidimensional Langevin equations combined with the statistical description of nuclear decay by particles evaporation is capable of fairly well describing the formation of fission fragment mass-energy, charge, and angular distributions of fission fragments in coincidence with the pre- and post-scission particle emission. The final yields of fission and evaporation residues channels products could be obtained. The detailed description of fission dynamics allows studying different stages of fission process, indicating the most important ingredients governing fission process and studying in detail such fundamental nuclear properties as nuclear viscosity and fission timescale. The tasks and perspectives of multidimensional dynamical approach are also discussed.

  16. Postoperative Airway Obstruction by a Bone Fragment

    Directory of Open Access Journals (Sweden)

    Patrick Schober

    2017-01-01

    Full Text Available Postoperative airway obstructions are potentially life-threatening complications. These obstructions may be classified as functional (sagging tongue, laryngospasm, or bronchospasm, pathoanatomical (airway swelling or hematoma within the airways, or foreign body-related. Various cases of airway obstruction by foreign bodies have previously been reported, for example, by broken teeth or damaged airway instruments. Here we present the exceptional case of a postoperative airway obstruction due to a large fragment of the patient’s maxillary bone, left accidentally in situ after transoral surgical tumor resection. Concerning this type of airway obstruction, we discuss possible causes, diagnosis, and treatment options. Although it is an exceptional case after surgery, clinicians should be aware of this potentially life-threatening complication. In summary, this case demonstrates that the differential diagnosis of postoperative airway obstructions should include foreign bodies derived from surgery, including tissue and bone fragments.

  17. Dynamic contributions to symmetric fragmentation processes

    Science.gov (United States)

    Schulte, H.; Jäckel, B.; Esterlund, R. A.; Knaack, M.; Westmeier, W.; Rox, A.; Patzelt, P.

    1989-11-01

    Angular-distribution anisotropies of fission/fissionlike products from the reactions 5.3 and 7.5 MeV/u 40Ar+ 197Au have been determined as a function of exit-channel mass asymmetry α. At sufficiently large α, the angular distributions become asymmetric about 90° in the rest frame, indicating that the symmetric fragmentation component in this system includes contributions from dynamic processes.

  18. Fragmentation of very high energy heavy ions

    CERN Document Server

    Giorgini, M

    2001-01-01

    A stack of CR39 (C12H18O7)n nuclear track detectors with a Cu target was exposed to a 158 A GeV lead ion beam at the CERN-SPS, in order to study the fragmentation properties of lead nuclei. Measurements of the total, break-up and pick-up charge-changing cross sections of ultrarelativistic Pb ions on Cu and CR39 targets are presented and discussed.

  19. Intentional Information Fragmentation in Email Management

    OpenAIRE

    Shanahan, Daniel Patrick

    2012-01-01

    Personal Information Management (PIM) studies the practice of storing, organizing, and retrieving information by an individual in support of their roles and tasks (Bergman, et al., 2004). One important problem in PIM is information fragmentation (IF) â the condition of having data in different formats, distributed across multiple locations, manipulated by different applications, and residing in a generally disconnected manner (Tungare, 2007). IF can conflict with the PIM ideal that users sh...

  20. N/z Dependence of Projectile Fragmentation

    Science.gov (United States)

    Trautmann, W.; Adrich, P.; Aumann, T.; Bacri, C. O.; Barczyk, T.; Bassini, R.; Bianchin, S.; Boiano, C.; Botvina, A. S.; Boudard, A.; Brzychczyk, J.; Chbihi, A.; Cibor, J.; Czech, B.; de Napoli, M.; Ducret, J.-É.; Emling, H.; Frankland, J. D.; Hellström, M.; Henzlova, D.; Immè, G.; Iori, I.; Johansson, H.; Kezzar, K.; Lafriakh, A.; Le Fèvre, A.; Le Gentil, E.; Leifels, Y.; Lühning, J.; Łukasik, J.; Lynch, W. G.; Lynen, U.; Majka, Z.; Mocko, M.; Müller, W. F. J.; Mykulyak, A.; Orth, H.; Otte, A. N.; Palit, R.; Pawłowski, P.; Pullia, A.; Raciti, G.; Rapisarda, E.; Sann, H.; Schwarz, C.; Sfienti, C.; Simon, H.; Sümmerer, K.; Tsang, M. B.; Verde, G.; Volant, C.; Wallace, M.; Weick, H.; Wiechula, J.; Wieloch, A.; Zwiegliński, B.

    The N/Z dependence of projectile fragmentation at relativistic energies has been studied in a recent experiment at the GSI laboratory with the ALADiN forward spectrometer coupled to the LAND neutron detector. Besides a primary beam of 124Sn, also secondary beams of 124La and 107Sn delivered by the FRS fragment separator have been used in order to extend the range of isotopic compositions of the produced spectator sources. With the achieved mass resolution of ΔA/A ≈ 1.5%, lighter isotopes with atomic numbers Z ≤ 10 are individually resolved. The presently ongoing analyses of the measured isotope yields focus on isoscaling and its relation to the properties of hot fragments at freeze-out and on the derivation of chemical freeze-out temperatures which are found to be independent of the isotopic composition of the studied systems. The latter result is at variance with the predictions for limiting temperatures as obtained with finite-temperature Hartree-Fock calculations.

  1. Gluon fragmentation into P wave heavy quarkonium

    Energy Technology Data Exchange (ETDEWEB)

    Braaten, Eric; Yuan, Tzu Chiang

    1994-03-01

    The fragmentation functions for gluons to split into P-wave heavy quarkonium states are calculated to leading order in the QCD coupling constant. Long-distance effects are factored into two nonperturbative parameters: the derivative of the radial wavefunction at the origin and a second parameter related to the probability for a heavy-quark-antiquark pair that is produced in a color-octet S-wave state to form a color-singlet P-wave bound state. The fragmentation probabilities for a high transverse momentum gluon to split into the P-wave charmonium states \\chi_{c0}, \\chi_{c1}, and \\chi_{c2} are estimated to be 0.4 \\times 10^{-4}, 1.8 \\times 10^{-4}, and 2.4 \\times 10^{-4}, respectively. This fragmentation process may account for a significant fraction of the rate for the inclusive production of \\chi_{cJ} at large transverse momentum in p \\bar p colliders.

  2. Commissioning the A1900 projectile fragment separator

    CERN Document Server

    Morrissey, D J; Steiner, M; Stolz, A; Wiedenhöver, I

    2003-01-01

    An important part of the recent upgrade of the NSCL facility is the replacement of the A1200 fragment separator with a new high acceptance device called the A1900. The design of the A1900 device represents a third generation projectile fragment separator (relative to the early work at LBL) as it is situated immediately after the primary accelerator, has a very large acceptance, a bending power significantly larger than that of the cyclotron and is constructed from large superconducting magnets (quadrupoles with 20 and 40 cm diameter warm bores). The A1900 can accept over 90% of a large range of projectile fragmentation products produced at the NSCL, leading to large gains in the intensity of the secondary beams. The results of initial tests of the system with a restricted momentum acceptance (+-0.5%) indicate that the A1900 is performing up to specifications. Further large gains in the intensities of primary beams, typically two or three orders of magnitude, will be possible as the many facets of high current...

  3. In silico fragment-based drug design.

    Science.gov (United States)

    Konteatis, Zenon D

    2010-11-01

    In silico fragment-based drug design (FBDD) is a relatively new approach inspired by the success of the biophysical fragment-based drug discovery field. Here, we review the progress made by this approach in the last decade and showcase how it complements and expands the capabilities of biophysical FBDD and structure-based drug design to generate diverse, efficient drug candidates. Advancements in several areas of research that have enabled the development of in silico FBDD and some applications in drug discovery projects are reviewed. The reader is introduced to various computational methods that are used for in silico FBDD, the fragment library composition for this technique, special applications used to identify binding sites on the surface of proteins and how to assess the druggability of these sites. In addition, the reader will gain insight into the proper application of this approach from examples of successful programs. In silico FBDD captures a much larger chemical space than high-throughput screening and biophysical FBDD increasing the probability of developing more diverse, patentable and efficient molecules that can become oral drugs. The application of in silico FBDD holds great promise for historically challenging targets such as protein-protein interactions. Future advances in force fields, scoring functions and automated methods for determining synthetic accessibility will all aid in delivering more successes with in silico FBDD.

  4. Cationized Carbohydrate Gas-Phase Fragmentation Chemistry

    Science.gov (United States)

    Bythell, Benjamin J.; Abutokaikah, Maha T.; Wagoner, Ashley R.; Guan, Shanshan; Rabus, Jordan M.

    2017-04-01

    We investigate the fragmentation chemistry of cationized carbohydrates using a combination of tandem mass spectrometry, regioselective labeling, and computational methods. Our model system is D-lactose. Barriers to the fundamental glyosidic bond cleavage reactions, neutral loss pathways, and structurally informative cross-ring cleavages are investigated. The most energetically favorable conformations of cationized D-lactose were found to be similar. In agreement with the literature, larger group I cations result in structures with increased cation coordination number which require greater collision energy to dissociate. In contrast with earlier proposals, the B n -Y m fragmentation pathways of both protonated and sodium-cationized analytes proceed via protonation of the glycosidic oxygen with concerted glycosidic bond cleavage. Additionally, for the sodiated congeners our calculations support sodiated 1,6-anhydrogalactose B n ion structures, unlike the preceding literature. This affects the subsequent propensity of formation and prediction of B n /Y m branching ratio. The nature of the anomeric center (α/β) affects the relative energies of these processes, but not the overall ranking. Low-energy cross-ring cleavages are observed for the metal-cationized analytes with a retro-aldol mechanism producing the 0,2 A 2 ion from the sodiated forms . Theory and experiment support the importance of consecutive fragmentation processes, particularly for the protonated congeners at higher collision energies.

  5. Fibril Fragmentation Enhances Amyloid Cytotoxicity*♦

    Science.gov (United States)

    Xue, Wei-Feng; Hellewell, Andrew L.; Gosal, Walraj S.; Homans, Steve W.; Hewitt, Eric W.; Radford, Sheena E.

    2009-01-01

    Fibrils associated with amyloid disease are molecular assemblies of key biological importance, yet how cells respond to the presence of amyloid remains unclear. Cellular responses may not only depend on the chemical composition or molecular properties of the amyloid fibrils, but their physical attributes such as length, width, or surface area may also play important roles. Here, we report a systematic investigation of the effect of fragmentation on the structural and biological properties of amyloid fibrils. In addition to the expected relationship between fragmentation and the ability to seed, we show a striking finding that fibril length correlates with the ability to disrupt membranes and to reduce cell viability. Thus, despite otherwise unchanged molecular architecture, shorter fibrillar samples show enhanced cytotoxic potential than their longer counterparts. The results highlight the importance of fibril length in amyloid disease, with fragmentation not only providing a mechanism by which fibril load can be rapidly increased but also creating fibrillar species of different dimensions that can endow new or enhanced biological properties such as amyloid cytotoxicity. PMID:19808677

  6. Intermittency in {sup 197}Au fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowska, A.; Holynski, R.; Olszewski, A.; Szarska, M.; Wilczynska, B.; Wolter, W.; Wosiek, B. [Institute of Nuclear Physics, Cracow (Poland); Cherry, M.L.; Deines-Jones, P.; Jones, W.V.; Sengupta, K.; Wefel, B. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; Waddington, C.J. [Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy; Pozharova, E.A.; Skorodko, T.Yu. [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation); KLMM Collaboration

    1995-07-01

    The concept of factorial moments was applied to an analysis of the dynamical fluctuations in the charge distributions of the fragments emitted from gold nuclei with energies 10.6 and < 1.0 GeV/n interacting with emulsion nuclei. Clear evidence for intermittent fluctuations has been found in an analysis using all the particles released from the gold projectile, with a stronger effect observed below 1 GeV/n than at 10.6 GeV/n. For the full data sets, however, the intermittency effect was found to be very sensitive to the singly charged particles, and neglecting these particles strongly reduces the intermittency signal. When the analysis is restricted to the multiply charged fragments, an intermittency effect is revealed only for multifragmentation events, although one that is enhanced as compared to the analysis of all, singly and multiply charged, particles. The properties of the anomalous fractal dimensions suggest a sequential decay mechanism, rather than the existence of possible critical behaviour in the process of nuclear fragmentation. The likely influence of the charge conservation effects and the finite size of decaying systems on the observed intermittency signals was pointed out. (author). 37 refs, 9 figs, 5 tabs.

  7. Fish responses to experimental fragmentation of seagrass habitat.

    Science.gov (United States)

    Macreadie, Peter I; Hindell, Jeremy S; Jenkins, Gregory P; Connolly, Rod M; Keough, Michael J

    2009-06-01

    Understanding the consequences of habitat fragmentation has come mostly from comparisons of patchy and continuous habitats. Because fragmentation is a process, it is most accurately studied by actively fragmenting large patches into multiple smaller patches. We fragmented artificial seagrass habitats and evaluated the impacts of fragmentation on fish abundance and species richness over time (1 day, 1 week, 1 month). Fish assemblages were compared among 4 treatments: control (single, continuous 9-m(2) patches); fragmented (single, continuous 9-m(2) patches fragmented to 4 discrete 1-m(2) patches); prefragmented/patchy (4 discrete 1-m(2) patches with the same arrangement as fragmented); and disturbance control (fragmented then immediately restored to continuous 9-m(2) patches). Patchy seagrass had lower species richness than actively fragmented seagrass (up to 39% fewer species after 1 week), but species richness in fragmented treatments was similar to controls. Total fish abundance did not vary among treatments and therefore was unaffected by fragmentation, patchiness, or disturbance caused during fragmentation. Patterns in species richness and abundance were consistent 1 day, 1 week, and 1 month after fragmentation. The expected decrease in fish abundance from reduced total seagrass area in fragmented and patchy seagrass appeared to be offset by greater fish density per unit area of seagrass. If fish prefer to live at edges, then the effects of seagrass habitat loss on fish abundance may have been offset by the increase (25%) in seagrass perimeter in fragmented and patchy treatments. Possibly there is some threshold of seagrass patch connectivity below which fish abundances cannot be maintained. The immediate responses of fish to experimental habitat fragmentation provided insights beyond those possible from comparisons of continuous and historically patchy habitat. ©2009 Society for Conservation Biology.

  8. A tetranuclear cubane-like nickel(II complex with a tridentate salicylideneimine Schiff base ligand: tetrakis[μ3-4-methyl-N-(2-oxidophenylsalicylideneiminato]tetrakis[methanolnickel(II] methanol 0.8-solvate

    Directory of Open Access Journals (Sweden)

    Gordana Pavlović

    2016-12-01

    Full Text Available The tetranuclear title complex, [Ni4(C14H11NO24(CH3OH4]·0.8CH3OH, has a distorted cubane topology shaped by four Schiff base ligands. The cubane [Ni4(μ3-O4] core is formed via the O atoms from the Schiff base ligands. The octahedrally coordinated NiII ions occupy alternating vertices of the cube. Each NiII ion is coordinated by one O,N,O′-tridentate dianionic ligand, two O atoms of oxidophenyl groups from adjacent ligands and the O atom of a coordinating methanol molecule. The cubane core is stabilized via an intramolecular O—H...O hydrogen bond between the hydroxy group of the coordinating methanol molecules and the phenolate O atom of the aldehyde Schiff base fragment. Additional stabilization is obtained via intramolecular C—H...O hydrogen bonds involving aromatic C—H groups and the oxygen atoms of adjacent methanol molecules. In the crystal, complex molecules are linked into chains parallel to the c axis via weak C—H...O hydrogen bonds. The partial-occupancy disordered methanol solvent molecule has a site occupancy of 0.8 and is linked to the tetranuclear unit via an intermolecular C—H...O hydrogen bond involving a phenolate O atom.

  9. Evaluation of core modeling effect on transients for multi-flow zone design of SFR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Andong; Choi, Yong Won [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-10-15

    SFR core is composed of different types of assemblies including fuel driver, reflector, blanket, control, safety drivers and other drivers. Modeling of different types of assemblies is inevitable in general. But modeling of core flow zones of with different channels needs a lot of effort and could be a challenge for system code modeling due to its limitation on the number of modeling components. In this study, core modeling effect on SFR transient was investigated with flow-zone model and averaged inner core channel model to improve modeling efficiency and validation of simplified core model for EBR-II loss of flow transient case with the modified TRACE code for SFRs. Core modeling effect on the loss flow transient was analyzed with flow-zoned channel model, single averaged inner core model and highest flow channel with averaged inner core channel model for EBR-II SHRT-17 test core. Case study showed that estimations of transient pump and channel flow as well as channel outlet temperatures were similar for all cases macroscopically. Comparing the result of the base case (flow-zone channel inner core model) and the case 2 (highest flow channel considered averaged inner core channel model), flow and channel outlet temperature response were closer than the case1 (single averaged inner core model)

  10. Observing Turbulent Fragmentation In Simulations: Through the Looking Glass of CARMA and ALMA

    Science.gov (United States)

    Offner, Stella; Capodilupo, J.; Schnee, S.; Goodman, A.

    2012-01-01

    We use the CASA software package to synthetically observe binaries forming as a result of turbulent fragmentation in a radiation-hydrodynamic simulation of a collapsing molecular cloud. By following the evolution of such pairs beginning in the prestellar core stage, we are able to make predictions about the feasibility of observing such fragmentation using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the Atacama Large Millimeter/submillimeter Array (ALMA). We find that while intermediate ALMA configurations may potentially resolve structure with one fourth the integration time of CARMA, both instruments only marginally resolve sub-structure within 25 kyr of the onset of gravitational collapse. In addition, interferometric spatial filtering significantly reduces traces of filamentary gas morphology on < 0.1 pc scales. Thus, even with the improved sub-arcsecond resolution of ALMA, constraining stellar multiplicity at the earliest stages of star formation will be challenging.

  11. Optimizing performance by improving core stability and core strength.

    Science.gov (United States)

    Hibbs, Angela E; Thompson, Kevin G; French, Duncan; Wrigley, Allan; Spears, Iain

    2008-01-01

    Core stability and core strength have been subject to research since the early 1980s. Research has highlighted benefits of training these processes for people with back pain and for carrying out everyday activities. However, less research has been performed on the benefits of core training for elite athletes and how this training should be carried out to optimize sporting performance. Many elite athletes undertake core stability and core strength training as part of their training programme, despite contradictory findings and conclusions as to their efficacy. This is mainly due to the lack of a gold standard method for measuring core stability and strength when performing everyday tasks and sporting movements. A further confounding factor is that because of the differing demands on the core musculature during everyday activities (low load, slow movements) and sporting activities (high load, resisted, dynamic movements), research performed in the rehabilitation sector cannot be applied to the sporting environment and, subsequently, data regarding core training programmes and their effectiveness on sporting performance are lacking. There are many articles in the literature that promote core training programmes and exercises for performance enhancement without providing a strong scientific rationale of their effectiveness, especially in the sporting sector. In the rehabilitation sector, improvements in lower back injuries have been reported by improving core stability. Few studies have observed any performance enhancement in sporting activities despite observing improvements in core stability and core strength following a core training programme. A clearer understanding of the roles that specific muscles have during core stability and core strength exercises would enable more functional training programmes to be implemented, which may result in a more effective transfer of these skills to actual sporting activities.

  12. Designing an Institutional Web-based Core Facility Management System

    Science.gov (United States)

    Tabarini, D.; Clisham, S.; John, D.; Hagen, A.

    2011-01-01

    The authors and their four institutions collaborated to (i) identify the key challenges to core facility management; (ii) identify the requirements for an effective core facility management system; (iii) design, test and deploy such a system. Through a series of interviews with all participants in the core work flow (customers, core staff, administrators), the team identified a number of key challenges, including: (i) difficulty for researchers in identifying available services; (ii) inconsistent processes for requesting services; (iii) inadequate controls for approving service requests; (iv) inefficient processes for tracking and communicating about project processes; (v) time-consuming billing practices; (vi) incomplete revenue capture; (vii) manual reporting processes. The team identified the following requirements for a system to address these challenges: (i) ability to support a broad range of core business practices such as complex quote generation and project management; calendaring/equipment reservation management; sample tracking; complex forms; and import of usage data from hardware; (ii) ability to offer services for both internal and external customers, including flexible pricing and off-site access; (iii) ability to interact with institutional financial systems (e.g. SAP, PeopleSoft, Lawson, SunGard Banner) and identify management systems (e.g. Microsoft Active Directory, LDAP, and other SAML 2.0-compliant services). The team developed and deployed this system across the collaborative partners, as well as other major research institutions.

  13. Sub-structure formation in starless cores

    Science.gov (United States)

    Toci, C.; Galli, D.; Verdini, A.; Del Zanna, L.; Landi, S.

    2018-02-01

    Motivated by recent observational searches of sub-structure in starless molecular cloud cores, we investigate the evolution of density perturbations on scales smaller than the Jeans length embedded in contracting isothermal clouds, adopting the same formalism developed for the expanding Universe and the solar wind. We find that initially small amplitude, Jeans-stable perturbations (propagating as sound waves in the absence of a magnetic field) are amplified adiabatically during the contraction, approximately conserving the wave action density, until they either become non-linear and steepen into shocks at a time tnl, or become gravitationally unstable when the Jeans length decreases below the scale of the perturbations at a time tgr. We evaluate analytically the time tnl at which the perturbations enter the non-linear stage using a Burgers' equation approach, and we verify numerically that this time marks the beginning of the phase of rapid dissipation of the kinetic energy of the perturbations. We then show that for typical values of the rms Mach number in molecular cloud cores, tnl is smaller than tgr, and therefore density perturbations likely dissipate before becoming gravitational unstable. Solenoidal modes grow at a faster rate than compressible modes, and may eventually promote fragmentation through the formation of vortical structures.

  14. Fragmentation of armor piercing steel projectiles upon oblique perforation of steel plates

    Directory of Open Access Journals (Sweden)

    Aizik F.

    2012-08-01

    Full Text Available In this study, a constitutive strength and failure model for a steel core of a14.5 mm API projectile was developed. Dynamic response of a projectile steel core was described by the Johnson-Cook constitutive model combined with principal tensile stress spall model. In order to obtain the parameters required for numerical description of projectile core material behavior, a series of planar impact experiments was done. The parameters of the Johnson-Cook constitutive model were extracted by matching simulated and experimental velocity profiles of planar impact. A series of oblique ballistic experiments with x-ray monitoring was carried out to study the effect of obliquity angle and armor steel plate thickness on shattering behavior of the 14.5 mm API projectile. According to analysis of x-ray images the fragmentation level increases with both steel plate thickness and angle of inclination. The numerical modeling of the ballistic experiments was done using commercial finite element code, LS-DYNA. Dynamic response of high hardness (HH armor steel was described using a modified Johnson-Cook strength and failure model. A series of simulations with various values of maximal principal tensile stress was run in order to capture the overall fracture behavior of the projectile’s core. Reasonable agreement between simulated and x-ray failure pattern of projectile core has been observed.

  15. Genotyping of Madurella mycetomatis by Selective Amplification of Restriction Fragments (Amplified Fragment Length Polymorphism) and Subtype Correlation with Geographical Origin and Lesion Size

    Science.gov (United States)

    van de Sande, Wendy W. J.; Gorkink, Roy; Simons, Guus; Ott, Alewijn; Ahmed, Abdalla O. A.; Verbrugh, Henri; van Belkum, Alex

    2005-01-01

    One of the causative organisms of mycetoma is the fungus Madurella mycetomatis. Previously, extensive molecular typing studies identified Sudanese isolates of this fungus as clonal, but polymorphic genetic markers have not yet been identified. Here, we report on the selective amplification of restriction fragment (AFLP) analysis of 37 Sudanese clinical isolates of M. mycetomatis. Of 93 AFLP fragments generated, 25 were polymorphic, and 12 of these 25 polymorphic fragments were found in a large fraction of the strains. Comparative analysis resulted into a tree, composed of two main (clusters I and II) and one minor cluster (cluster III). Seventy-five percent of the strains found in cluster I originated from central Sudan, while the origin of the strains in cluster II was more heterogeneous. Furthermore, the strains found in cluster I were generally obtained from lesions larger than those from which the strains found in cluster II were obtained (chi-square test for trend, P = 0.03). Among the 12 more commonly found polymorphisms, 4 showed sequence homology with known genes. Marker A7 was homologous to an endo-1,4-beta-glucanase from Aspergillus oryzae, 97% identical markers A12 and B3 matched a hypothetical protein from Gibberella zeae, and marker B4 was homologous to casein kinase I from Danio rerio. The last marker seemed to be associated with strains originating from central Sudan (P = 0.001). This is the first report on a genotypic study where genetic markers which may be used to study pathogenicity in M. mycetomatis were obtained. PMID:16145076

  16. Fragmented Romanian Sociology: Growth and Structure of the Collaboration Network

    Science.gov (United States)

    Hâncean, Marian-Gabriel; Perc, Matjaž; Vlăsceanu, Lazăr

    2014-01-01

    Structural patterns in collaboration networks are essential for understanding how new ideas, research practices, innovation or cooperation circulate and develop within academic communities and between and within university departments. In our research, we explore and investigate the structure of the collaboration network formed by the academics working full-time within all the 17 sociology departments across Romania. We show that the collaboration network is sparse and fragmented, and that it constitutes an environment that does not promote the circulation of new ideas and innovation within the field. Although recent years have witnessed an increase in the productivity of Romanian sociologists, there is still ample room for improvement in terms of the interaction infrastructure that ought to link individuals together so that they could maximize their potentials. We also fail to discern evidence in favor of the Matthew effect governing the growth of the network, which suggests scientific success and productivity are not rewarded. Instead, the structural properties of the collaboration network are partly those of a core-periphery network, where the spread of innovation and change can be explained by structural equivalence rather than by interpersonal influence models. We also provide support for the idea that, within the observed network, collaboration is the product of homophily rather than prestige effects. Further research on the subject based on data from other countries in the region is needed to place our results in a comparative framework, in particular to discern whether the behavior of the Romanian sociologist community is unique or rather common. PMID:25409180

  17. Fragmented Romanian sociology: growth and structure of the collaboration network.

    Directory of Open Access Journals (Sweden)

    Marian-Gabriel Hâncean

    Full Text Available Structural patterns in collaboration networks are essential for understanding how new ideas, research practices, innovation or cooperation circulate and develop within academic communities and between and within university departments. In our research, we explore and investigate the structure of the collaboration network formed by the academics working full-time within all the 17 sociology departments across Romania. We show that the collaboration network is sparse and fragmented, and that it constitutes an environment that does not promote the circulation of new ideas and innovation within the field. Although recent years have witnessed an increase in the productivity of Romanian sociologists, there is still ample room for improvement in terms of the interaction infrastructure that ought to link individuals together so that they could maximize their potentials. We also fail to discern evidence in favor of the Matthew effect governing the growth of the network, which suggests scientific success and productivity are not rewarded. Instead, the structural properties of the collaboration network are partly those of a core-periphery network, where the spread of innovation and change can be explained by structural equivalence rather than by interpersonal influence models. We also provide support for the idea that, within the observed network, collaboration is the product of homophily rather than prestige effects. Further research on the subject based on data from other countries in the region is needed to place our results in a comparative framework, in particular to discern whether the behavior of the Romanian sociologist community is unique or rather common.

  18. Fragmented Romanian sociology: growth and structure of the collaboration network.

    Science.gov (United States)

    Hâncean, Marian-Gabriel; Perc, Matjaž; Vlăsceanu, Lazăr

    2014-01-01

    Structural patterns in collaboration networks are essential for understanding how new ideas, research practices, innovation or cooperation circulate and develop within academic communities and between and within university departments. In our research, we explore and investigate the structure of the collaboration network formed by the academics working full-time within all the 17 sociology departments across Romania. We show that the collaboration network is sparse and fragmented, and that it constitutes an environment that does not promote the circulation of new ideas and innovation within the field. Although recent years have witnessed an increase in the productivity of Romanian sociologists, there is still ample room for improvement in terms of the interaction infrastructure that ought to link individuals together so that they could maximize their potentials. We also fail to discern evidence in favor of the Matthew effect governing the growth of the network, which suggests scientific success and productivity are not rewarded. Instead, the structural properties of the collaboration network are partly those of a core-periphery network, where the spread of innovation and change can be explained by structural equivalence rather than by interpersonal influence models. We also provide support for the idea that, within the observed network, collaboration is the product of homophily rather than prestige effects. Further research on the subject based on data from other countries in the region is needed to place our results in a comparative framework, in particular to discern whether the behavior of the Romanian sociologist community is unique or rather common.

  19. Colorado Plateau Rapid Ecoregion Assessment Indicators: Natural Vegetation Fragmentation

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — This dataset presents measures of landscape fragmentation calculated by FRAGSTATS at 4KM and HUC5 reporting unit levels. Fragmentation integrates the influence of...

  20. Fragmentation Point Detection of JPEG Images at DHT Using Validator

    Science.gov (United States)

    Mohamad, Kamaruddin Malik; Deris, Mustafa Mat

    File carving is an important, practical technique for data recovery in digital forensics investigation and is particularly useful when filesystem metadata is unavailable or damaged. The research on reassembly of JPEG files with RST markers, fragmented within the scan area have been done before. However, fragmentation within Define Huffman Table (DHT) segment is yet to be resolved. This paper analyzes the fragmentation within the DHT area and list out all the fragmentation possibilities. Two main contributions are made in this paper. Firstly, three fragmentation points within DHT area are listed. Secondly, few novel validators are proposed to detect these fragmentations. The result obtained from tests done on manually fragmented JPEG files, showed that all three fragmentation points within DHT are successfully detected using validators.