Sample records for face au dfi

  1. CxP Wireless DFI Summary Presentation for OTI Flight Test Working Group

    NASA Technical Reports Server (NTRS)

    Arteaga, Ricardo A.

    2009-01-01

    This slide presentation reviews the wireless instrumentation architecture needed for the Alatir Lunar Lander, Ares I, Ares V, and the Block II Orion Crew Exploration Vehicle (CEV). It includes information about the Wireless DFI system, mission planning, and the technology roadmap.

  2. Crystal-face-selective adsorption of Au nanoparticles onto polycrystalline diamond surfaces.

    PubMed

    Kondo, Takeshi; Aoshima, Shinsuke; Hirata, Kousuke; Honda, Kensuke; Einaga, Yasuaki; Fujishima, Akira; Kawai, Takeshi

    2008-07-15

    Crystal-face-selective adsorption of Au nanoparticles (AuNPs) was achieved on polycrystalline boron-doped diamond (BDD) surface via the self-assembly method combined with a UV/ozone treatment. To the best of our knowledge, this is the first report of crystal-face-selective adsorption on an inorganic solid surface. Hydrogen-plasma-treated BDD samples and those followed by UV/ozone treatment for 2 min or longer showed almost no adsorption of AuNP after immersion in the AuNP solution prepared by the citrate reduction method. However, the samples treated by UV/ozone for 10 s showed AuNP adsorption on their (111) facets selectively after the immersion. Moreover, the sample treated with UV/ozone for 40-60 s showed AuNP adsorption on the whole surface. These results indicate that the AuNP adsorption behavior can be controlled by UV/ozone treatment time. This phenomenon was highly reproducible and was applied to a two-step adsorption method, where AuNPs from different batches were adsorbed on the (111) and (100) surface in this order. Our findings may be of great value for the fabrication of advanced nanoparticle-based functional materials via bottom-up approaches with simple macroscale procedures.

  3. Successful synthesis and thermal stability of immiscible metal Au-Rh, Au-Ir andAu-Ir-Rh nanoalloys

    NASA Astrophysics Data System (ADS)

    Shubin, Yury; Plyusnin, Pavel; Sharafutdinov, Marat; Makotchenko, Evgenia; Korenev, Sergey

    2017-05-01

    We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn2][Ir(NO2)6], [AuEn2][Ir(NO2)6] х [Rh(NO2)6]1-х and [AuEn2][Rh(NO2)6]. The precursors employed contain all desired metals ‘mixed’ at the atomic level, thus providing significant advantages for obtaining alloys. The observations using high-resolution transmission electron microscopy show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5 ± 3 nm. Еnergy dispersive x-ray spectroscopy and x-ray powder diffraction (XRD) measurements confirm the formation of AuIr, AuRh, AuIr0.75Rh0.25, AuIr0.50Rh0.50 and AuIr0.25Rh0.75 metastable solid solutions. In situ high-temperature synchrotron XRD (HTXRD) was used to study the formation mechanism of nanoalloys. The observed transformations are described by the ‘conversion chemistry’ mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 °C for 30 h does not cause any dealloying process.

  4. Successful synthesis and thermal stability of immiscible metal Au-Rh, Au-Ir andAu-Ir-Rh nanoalloys.

    PubMed

    Shubin, Yury; Plyusnin, Pavel; Sharafutdinov, Marat; Makotchenko, Evgenia; Korenev, Sergey

    2017-05-19

    We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn 2 ][Ir(NO 2 ) 6 ], [AuEn 2 ][Ir(NO 2 ) 6 ] х [Rh(NO 2 ) 6 ] 1-х and [AuEn 2 ][Rh(NO 2 ) 6 ]. The precursors employed contain all desired metals 'mixed' at the atomic level, thus providing significant advantages for obtaining alloys. The observations using high-resolution transmission electron microscopy show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5 ± 3 nm. Еnergy dispersive x-ray spectroscopy and x-ray powder diffraction (XRD) measurements confirm the formation of AuIr, AuRh, AuIr 0.75 Rh 0.25 , AuIr 0.50 Rh 0.50 and AuIr 0.25 Rh 0.75 metastable solid solutions. In situ high-temperature synchrotron XRD (HTXRD) was used to study the formation mechanism of nanoalloys. The observed transformations are described by the 'conversion chemistry' mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 °C for 30 h does not cause any dealloying process.

  5. Evolution of Excited-State Dynamics in Periodic Au 28, Au 36, Au 44, and Au 52 Nanoclusters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhou, Meng; Zeng, Chenjie; Sfeir, Matthew Y.

    An understanding of the correlation between the atomic structure and optical properties of gold nanoclusters is essential for exploration of their functionalities and applications involving light harvesting and electron transfer. We report the femto-nanosecond excited state dynamics of a periodic series of face-centered cubic (FCC) gold nanoclusters (including Au 28, Au 36, Au 44, and Au 52), which exhibit a set of unique features compared with other similar sized clusters. Molecular-like ultrafast S n → S 1 internal conversions (i.e., radiationless electronic transitions) are observed in the relaxation dynamics of FCC periodic series. Excited-state dynamics with near-HOMO–LUMO gap excitation lacksmore » ultrafast decay component, and only the structural relaxation dominates in the dynamical process, which proves the absence of core–shell relaxation. Interestingly, both the relaxation of the hot carriers and the band-edge carrier recombination become slower as the size increases. The evolution in excited-state properties of this FCC series offers new insight into the structure-dependent properties of metal nanoclusters, which will benefit their optical energy harvesting and photocatalytic applications.« less

  6. Evolution of Excited-State Dynamics in Periodic Au 28, Au 36, Au 44, and Au 52 Nanoclusters

    DOE PAGES

    Zhou, Meng; Zeng, Chenjie; Sfeir, Matthew Y.; ...

    2017-08-10

    An understanding of the correlation between the atomic structure and optical properties of gold nanoclusters is essential for exploration of their functionalities and applications involving light harvesting and electron transfer. We report the femto-nanosecond excited state dynamics of a periodic series of face-centered cubic (FCC) gold nanoclusters (including Au 28, Au 36, Au 44, and Au 52), which exhibit a set of unique features compared with other similar sized clusters. Molecular-like ultrafast S n → S 1 internal conversions (i.e., radiationless electronic transitions) are observed in the relaxation dynamics of FCC periodic series. Excited-state dynamics with near-HOMO–LUMO gap excitation lacksmore » ultrafast decay component, and only the structural relaxation dominates in the dynamical process, which proves the absence of core–shell relaxation. Interestingly, both the relaxation of the hot carriers and the band-edge carrier recombination become slower as the size increases. The evolution in excited-state properties of this FCC series offers new insight into the structure-dependent properties of metal nanoclusters, which will benefit their optical energy harvesting and photocatalytic applications.« less

  7. Toward hybrid Au nanorods @ M (Au, Ag, Pd and Pt) core-shell heterostructures for ultrasensitive SERS probes

    NASA Astrophysics Data System (ADS)

    Xie, Xiaobin; Gao, Guanhui; Kang, Shendong; Lei, Yanhua; Pan, Zhengyin; Shibayama, Tamaki; Cai, Lintao

    2017-06-01

    Being able to precisely control the morphologies of noble metallic nanostructures is of essential significance for promoting the surface-enhanced Raman scattering (SERS) effect. Herein, we demonstrate an overgrowth strategy for synthesizing Au @ M (M = Au, Ag, Pd, Pt) core-shell heterogeneous nanocrystals with an orientated structural evolution and highly improved properties by using Au nanorods as seeds. With the same reaction condition system applied, we obtain four well-designed heterostructures with diverse shapes, including Au concave nanocuboids (Au CNs), Au @ Ag crystalizing face central cube nanopeanuts, Au @ Pd porous nanocuboids and Au @ Pt nanotrepangs. Subsequently, the exact overgrowth mechanism of the above heterostructural building blocks is further analysed via the systematic optimiziation of a series of fabrications. Remarkably, the well-defined Au CNs and Au @ Ag nanopeanuts both exhibit highly promoted SERS activity. We expect to be able to supply a facile strategy for the fabrication of multimetallic heterogeneous nanostructures, exploring the high SERS effect and catalytic activities.

  8. Ohmic contacts to N-face p-GaN using Ni/Au for the fabrication of polarization inverted light-emitting diodes.

    PubMed

    Han, Seung Cheol; Kim, Jae-Kwan; Kim, Jun Young; Lee, Dong Min; Yoon, Jae-Sik; Kim, Jong-Kyu; Schubert, E F; Lee, Ji-Myon

    2013-08-01

    The electrical properties of Ni-based ohmic contacts to N-face p-type GaN were investigated. The specific contact resistance of N-face p-GaN exhibits a linear decrease from 1.01 omega cm2 to 9.05 x 10(-3) omega cm2 for the as-deposited and the annealed Ni/Au contacts, respectively, with increasing annealing temperature. However, the specific contact resistance could be decreased down to 1.03 x 10(-4) omega cm2 by means of surface treatment using an alcohol-based (NH4)2S solution. The depth profile data measured from the intensity of O1s peak in the X-ray photoemission spectra showed that the alcohol-based (NH4)2S treatment was effective in removing the surface oxide layer of GaN.

  9. Novel condensation of Au-centered trigonal prisms in rare-earth-metal-rich tellurides: Er7Au2Te2 and Lu7Au2Te2.

    PubMed

    Gupta, Shalabh; Corbett, John D

    2010-07-14

    A new monoclinic structure occurs for Er(7)Au(2)Te(2) according to X-ray diffraction analysis of single crystals grown at 1200 degrees C: C2/m, Z = 4, a = 17.8310(9) A, b = 3.9819(5) A, c = 16.9089(9) A, beta = 104.361(4) degrees. The isostructural Lu(7)Au(2)Te(2) also exists according to X-ray powder pattern means, a = 17.536(4) A, b = 3.9719(4) A, c = 16.695(2) A, beta = 104.33(1) degrees. The structure contains zigzag chains of condensed, Au-centered tricapped trigonal prisms (TCTP) of Er along c that also share basal faces along b to generate puckered sheets. Further bi-face-capping Er atoms between these generate the three dimensional network along a, with tellurium in cavities outlined by augmented trigonal prismatic Er polyhedra. Bonding analysis via LMTO-DFT methods reveal very significant Er-Au bonding interactions, as quantified by their energy-weighted Hamilton overlap populations (-ICOHP), approximately 49% of the total for all interactions. These and similar Er-Te contributions sharply contrast with the small Er-Er population, only approximately 14% of the total in spite of the high proportion of Er-Er contacts. The strong polar bonding of Er to the electronegative Au and Te leaves Er relatively oxidized, with many of its 5d states falling above the Fermi level and empty. The contradiction with customary representations of structures that highlight rare-earth metal clusters is manifest. The large Er-Au Hamilton overlap population is in accord with the strong bonding between early and late transition metals first noted by Brewer in 1973. The relationship of this structure to the more distorted orthorhombic (Imm2) structure type of neighboring Dy(7)Ir(2)Te(2) is considered.

  10. Ultra-relativistic Au+Au and d+Au collisions:

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    In this talk I will review PHOBOS data on charged particle multiplicities, obtained in Au+Au and d+Au collisions at RHIC. The general features of the Au+Au pseudorapidity distributions results will be discussed and compared to those of /line{p}p collisions. The total charged particle multiplicity, scaled by the number of participant pairs, is observed to be about 40% higher in Au+Au collisions than in /line{p}p and d+Au systems, but, surprisingly at the same level of e+e- collisions. Limiting fragmentation scaling is seen to be obeyed in Au+Au collisions.

  11. Composition distributions in FePt(Au) nanoparticles

    NASA Astrophysics Data System (ADS)

    Srivastava, C.; Nikles, D. E.; Harrell, J. W.; Thompson, G. B.

    2010-08-01

    Ternary alloy FePt(Au) nanoparticles were prepared by the co-reduction of platinum(II) acetylacetonate and gold(III) acetate and the thermal decomposition of iron pentacarbonyl in hot phenyl ether in the presence of oleic acid and oleylamine ligands. This gave spherical particles with an average diameter of 4.4 nm with a range of diameters from approximately 1.6-9 nm. The as-synthesized particles had a solid solution, face-centered-cubic structure. Though the average composition of the particles was Fe44Pt45Au11, individual particle analysis by Scanning Transmission Electron Microscopy-X-ray Energy Dispersive Spectroscopy showed a broad distribution in composition. In general, smaller-sized particles tended to have a lower amount of Au as compared to larger-sized particles. As the Au content increased, the ratio of Fe/Pt widened.

  12. A density functional theory study on the acetylene cyclotrimerization on Pd-modified Au(111) surface

    NASA Astrophysics Data System (ADS)

    Ren, Bohua; Dong, Xiuqin; Yu, Yingzhe; Zhang, Minhua

    2017-10-01

    Calculations based on the first-principle density functional theory were carried out to study the possible acetylene cyclotrimerization reactions on Pd-Au(111) surface and to investigate the effect of Au atom alloying with Pd. The adsorption of C2H2, C4H4, C6H6 and the PDOS of 4d orbitals of surface Pd and Au atoms were studied. The comparison of d-band center of Pd and Au atom before and after C2H2 or C4H4 adsorption suggests that these molecules affect the activity of Pd-Au(111) surface to some degree due to the high binding energy of the adsorption. In our study, the second neighboring Pd ensembles on Pd-Au(111) surface can adsorb two acetylene molecules on parallel-bridge site of two Au atoms and one Pd atom, respectively. Csbnd C bonds are parallel to each other and two acetylenes are adsorbed face to face to produce four-membered ring C4H4 firstly. The geometric effect and electronic effect of Pd-Au(111) surface with the second neighboring Pd ensembles both help to reduce this activation barrier.

  13. Crystal Structural Effect of AuCu Alloy Nanoparticles on Catalytic CO Oxidation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhan, Wangcheng; Wang, Jinglin; Wang, Haifeng

    2017-06-07

    Controlling the physical and chemical properties of alloy nanoparticles (NPs) is an important approach to optimize NP catalysis. Unlike other tuning knobs, such as size, shape, and composition, crystal structure has received limited attention and not been well understood for its role in catalysis. This deficiency is mainly due to the difficulty in synthesis and fine-tuning of the NPs’ crystal structure. Here, Exemplifying by AuCu alloy NPs with face centered cubic (fcc) and face centered tetragonal (fct) structure, we demonstrate a remarkable difference in phase segregation and catalytic performance depending on the crystal structure. During the thermal treatment in air,more » the Cu component in fcc-AuCu alloy NPs segregates more easily onto the alloy surface as compared to that in fct-AuCu alloy NPs. As a result, after annealing at 250 °C in air for 1 h, the fcc- and fct-AuCu alloy NPs are phase transferred into Au/CuO and AuCu/CuO core/shell structures, respectively. More importantly, this variation in heterostructures introduces a significant difference in CO adsorption on two catalysts, leading to a largely enhanced catalytic activity of AuCu/CuO NP catalyst for CO oxidation. Furthermore, the same concept can be extended to other alloy NPs, making it possible to fine-tune NP catalysis for many different chemical reactions.« less

  14. Epitaxial growth of a mono-crystalline metastable AuIn layer at the Au/InP(001) interface

    NASA Astrophysics Data System (ADS)

    Renda, M.; Morita, K.

    1990-01-01

    Thermal annealing of a gold layer deposited on the InP(001)-p(2×4) surface has been studied in-situ by means of LEED, AES and RBS techniques and by post analysis of RBS-channeling and glancing incidence X-ray diffraction. A clean LEED pattern of p(2×2) spots was observed for the specimen annealed for 10 min at 300°C. The composition ratio of Au/In in the epitaxial compound layer was found to be 49/51 by RBS and several at% of P was also detected by post sputter-AES analysis. It was also found that the epitaxial layer shows a clear channeling dip for an incident ion beam which is aligned along the <001> axis of InP substrate. The glancing incidence X-ray diffraction analysis indicates diffraction peaks from the pseudo-orthorombic phase of AuIn. From these experimental results, it is concluded that the epitaxial Au-compound layer is a mono-crystalline metastable phase of AuIn, of which every three atomic rows of Au or In in the [110] direction would be situated on every four atomic rows in the [010] direction of the In(001) face of the InP crystal.

  15. Electrophoretic deposition of fluorescent Cu and Au sheets for light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Liu, Jiale; Wu, Zhennan; Li, Tingting; Zhou, Ding; Zhang, Kai; Sheng, Yu; Cui, Jianli; Zhang, Hao; Yang, Bai

    2015-12-01

    Electrophoretic deposition (EPD) is a conventional method for fabricating film materials from nanometer-sized building blocks, and exhibits the advantages of low-cost, high-efficiency, wide-range thickness adjustment, and uniform deposition. Inspired by the interest in the application of two-dimensional (2D) nanomaterials, the EPD technique has been recently extended to building blocks with 2D features. However, the studies are mainly focused on simplex building blocks. The utilization of multiplex building blocks is rarely reported. In this work, we demonstrate a controlled EPD of Cu and Au sheets, which are 2D assemblies of luminescent Cu and Au nanoclusters. Systematic investigations reveal that both the deposition efficiency and the thickness are determined by the lateral size of the sheets. For Cu sheets with a large lateral size, a high ζ-potential and strong face-to-face van der Waals interactions facilitate the deposition with high efficiency. However, for Au sheets, the small lateral size and ζ-potential limit the formation of a thick film. To solve this problem, the deposition dynamics are controlled by increasing the concentration of the Au sheets and adding acetone. This understanding permits the fabrication of a binary EPD film by the stepwise deposition of Cu and Au sheets, thus producing a luminescent film with both Cu green emission and Au red emission. A white light-emitting diode prototype with color coordinates (x, y) = (0.31, 0.36) is fabricated by employing the EPD film as a color conversion layer on a 365 nm GaN clip and further tuning the amount of deposited Cu and Au sheets.Electrophoretic deposition (EPD) is a conventional method for fabricating film materials from nanometer-sized building blocks, and exhibits the advantages of low-cost, high-efficiency, wide-range thickness adjustment, and uniform deposition. Inspired by the interest in the application of two-dimensional (2D) nanomaterials, the EPD technique has been recently extended to

  16. Synthesis of NiAu alloy and core-shell nanoparticles in water-in-oil microemulsions

    NASA Astrophysics Data System (ADS)

    Chiu, Hsin-Kai; Chiang, I.-Chen; Chen, Dong-Hwang

    2009-07-01

    NiAu alloy nanoparticles with various Ni/Au molar ratios were synthesized by the hydrazine reduction of nickel chloride and hydrogen tetrachloroaurate in the microemulsion system. They had a face-centered cubic structure and a mean diameter of 6-13 nm, decreasing with increasing Au content. As Au nanoparticles did, they showed a characteristic absorption peak at about 520 nm but the intensity decreased with increasing Ni content. Also, they were nearly superparamagnetic, although the magnetization decreased significantly with increasing Au content. Under an external magnetic field, they could be self-organized into the parallel lines. In addition, the core-shell nanoparticles, Ni3Au1@Au, were prepared by the Au coating on the surface of Ni3Au1 alloy nanoparticles. By increasing the hydrogen tetrachloroaurate concentration for Au coating, the thickness of Au shells could be raised and led to an enhanced and red-shifted surface plasmon absorption.

  17. Structural and morphological peculiarities of hybrid Au/nanodiamond engineered nanostructures

    NASA Astrophysics Data System (ADS)

    Matassa, Roberto; Orlanducci, Silvia; Reina, Giacomo; Cassani, Maria Cristina; Passeri, Daniele; Terranova, Maria Letizia; Rossi, Marco

    2016-08-01

    Nanostructured Au nano-platelets have been synthesized from an Au(III) complex by growth process triggered by nanodiamond (ND). An electroless synthetic route has been used to obtain 2D Au/ND architectures, where individual nanodiamond particles are intimately embedded into face-centered cubic Au platelets. The combined use of high resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED), was able to reveal the unusual organization of these hybrid nanoparticles, ascertaining the existence of preferential crystallographic orientations for both nanocrystalline species and highlighting their mutual locations. Detailed information on the sample microstructure have been gathered by fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT) of HR-TEM images, allowing us to figure out the role of Au defects, able to anchor ND crystallites and to provide specific sites for heteroepitaxial Au growth. Aggregates constituted by coupled ND and Au, represent interesting systems conjugating the best optoelectronics and plasmonics properties of the two different materials. In order to promote realistically the applications of such outstanding Au/ND materials, the cooperative mechanisms at the basis of material synthesis and their influence on the details of the hybrid nanostructures have to be deeply understood.

  18. Structural and morphological peculiarities of hybrid Au/nanodiamond engineered nanostructures

    PubMed Central

    Matassa, Roberto; Orlanducci, Silvia; Reina, Giacomo; Cassani, Maria Cristina; Passeri, Daniele; Terranova, Maria Letizia; Rossi, Marco

    2016-01-01

    Nanostructured Au nano-platelets have been synthesized from an Au(III) complex by growth process triggered by nanodiamond (ND). An electroless synthetic route has been used to obtain 2D Au/ND architectures, where individual nanodiamond particles are intimately embedded into face-centered cubic Au platelets. The combined use of high resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED), was able to reveal the unusual organization of these hybrid nanoparticles, ascertaining the existence of preferential crystallographic orientations for both nanocrystalline species and highlighting their mutual locations. Detailed information on the sample microstructure have been gathered by fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT) of HR-TEM images, allowing us to figure out the role of Au defects, able to anchor ND crystallites and to provide specific sites for heteroepitaxial Au growth. Aggregates constituted by coupled ND and Au, represent interesting systems conjugating the best optoelectronics and plasmonics properties of the two different materials. In order to promote realistically the applications of such outstanding Au/ND materials, the cooperative mechanisms at the basis of material synthesis and their influence on the details of the hybrid nanostructures have to be deeply understood. PMID:27514638

  19. Ultrathin Au-Alloy Nanowires at the Liquid-Liquid Interface.

    PubMed

    Chatterjee, Dipanwita; Shetty, Shwetha; Müller-Caspary, Knut; Grieb, Tim; Krause, Florian F; Schowalter, Marco; Rosenauer, Andreas; Ravishankar, Narayanan

    2018-03-14

    Ultrathin bimetallic nanowires are of importance and interest for applications in electronic devices such as sensors and heterogeneous catalysts. In this work, we have designed a new, highly reproducible and generalized wet chemical method to synthesize uniform and monodispersed Au-based alloy (AuCu, AuPd, and AuPt) nanowires with tunable composition using microwave-assisted reduction at the liquid-liquid interface. These ultrathin alloy nanowires are below 4 nm in diameter and about 2 μm long. Detailed microstructural characterization shows that the wires have an face centred cubic (FCC) crystal structure, and they have low-energy twin-boundary and stacking-fault defects along the growth direction. The wires exhibit remarkable thermal and mechanical stability that is critical for important applications. The alloy wires exhibit excellent electrocatalytic activity for methanol oxidation in an alkaline medium.

  20. Embedded atom method potential for studying mechanical properties of binary Cu–Au alloys

    NASA Astrophysics Data System (ADS)

    Gola, Adrien; Pastewka, Lars

    2018-07-01

    We present an embedded atom method (EAM) potential for the binary Cu–Au system. The unary phases are described by two well-tested unary EAM potentials for Cu and Au. We fitted the interaction between Cu and Au to experimental properties of the binary intermetallic phases Cu3Au, CuAu and CuAu3. Particular attention has been paid to reproducing stacking fault energies in order to obtain a potential suitable for studying deformation in this binary system. The resulting energies, lattice constant, elastic properties and melting points are in good agreement with available experimental data. We use nested sampling to show that our potential reproduces the phase boundaries between intermetallic phases and the disordered face-centered cubic solid solution. We benchmark our potential against four popular Cu–Au EAM parameterizations and density-functional theory calculations.

  1. Magnetic susceptibilities of liquid Cr-Au, Mn-Au and Fe-Au alloys

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ohno, S.; Shimakura, H.; Tahara, S.

    The magnetic susceptibility of liquid Cr-Au, Mn-Au, Fe-Au and Cu-Au alloys was investigated as a function of temperature and composition. Liquid Cr{sub 1-c}Au{sub c} with 0.5 ≤ c and Mn{sub 1-c}Au{sub c} with 0.3≤c obeyed the Curie-Weiss law with regard to their dependence of χ on temperature. The magnetic susceptibilities of liquid Fe-Au alloys also exhibited Curie-Weiss behavior with a reasonable value for the effective number of Bohr magneton. On the Au-rich side, the composition dependence of χ for liquid TM-Au (TM=Cr, Mn, Fe) alloys increased rapidly with increasing TM content, respectively. Additionally, the composition dependences of χ for liquidmore » Cr-Au, Mn-Au, and Fe-Au alloys had maxima at compositions of 50 at% Cr, 70 at% Mn, and 85 at% Fe, respectively. We compared the composition dependences of χ{sub 3d} due to 3d electrons for liquid binary TM-M (M=Au, Al, Si, Sb), and investigated the relationship between χ{sub 3d} and E{sub F} in liquid binary TM-M alloys at a composition of 50 at% TM.« less

  2. Lumbar lipomeningomyelocele associated with multiple café au lait spots: a case report.

    PubMed

    Balasubramanian, Pradeep; Srinivas, C R; Arunachalam, Pavai; Thirumurthy, K S; Rajkumar, P R; Manuvidhya, H

    2015-01-01

    We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique. © 2015 Wiley Periodicals, Inc.

  3. Time-resolved electronic and optical properties of a thiolate-protected Au38 nanocluster

    NASA Astrophysics Data System (ADS)

    Meng, Qingguo; May, Stanley P.; Berry, Mary T.; Kilin, Dmitri S.

    2015-02-01

    Density functional theory and density matrix theory are employed to investigate the time-dependent optical and electronic properties of an Au14 nanocluster protected by six cyclic thiolate ligands, Au4(SCH3)4. The Au14[Au4(SCH3)4]6 nanocluster, i.e. Au38(SCH3)24, is equivalent to a truncated-octahedral face-centred cubic Au38 core coated by a monolayer of 24 methylthiol molecules. The electronic and optical properties, such as density of states, linear absorption spectra, nonradiative nonadiabatic dissipative electronic dynamics and radiative emission spectra were calculated and compared for the core Au14 and thiolate-protected Au38(SCH3)24 nanocluster. The main observation from computed photoluminescence for both models is a mechanism of radiative emission. Specifically, a strong contribution to light emission intensity originates from intraband transitions inside the conduction band (CB) in addition to interband LUMO → HOMO transition (HOMO: highest occupied molecular orbital and LUMO: lowest unoccupied molecular orbital). Such comparison clarifies the contributions from Au core and methylthiol ligands to the electronic and optical properties of the Au38(SCH3)24 nanocluster.

  4. Efficient electrocatalytic conversion of CO.sub.2 to CO using ligand-protected Au.sub.25 clusters

    DOEpatents

    Kauffman, Douglas; Matranga, Christopher; Qian, Huifeng; Jin, Rongchao; Alfonso, Dominic R.

    2015-09-22

    An apparatus and method for CO.sub.2 reduction using an Au.sub.25 electrode. The Au.sub.25 electrode is comprised of ligand-protected Au.sub.25 having a structure comprising an icosahedral core of 13 atoms surrounded by a shell of six semi-ring structures bonded to the core of 13 atoms, where each semi-ring structure is typically --SR--Au--SR--Au--SR or --SeR--Au--SeR--Au--SeR. The 12 semi-ring gold atoms within the six semi-ring structures are stellated on 12 of the 20 faces of the icosahedron of the Au.sub.13 core, and organic ligand --SR or --SeR groups are bonded to the Au.sub.13 core with sulfur or selenium atoms. The Au.sub.25 electrode and a counter-electrode are in contact with an electrolyte comprising CO.sub.2 and H+, and a potential of at least -0.1 volts is applied from the Au.sub.25 electrode to the counter-electrode.

  5. From the ternary Eu(Au/In) 2 and EuAu 4(Au/In) 2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu 5Au 16(Au/In) 6 structure

    DOE PAGES

    Steinberg, Simon; Card, Nathan; Mudring, Anja -Verena

    2015-08-13

    The ternary Eu(Au/In) 2 (EuAu 0.46In 1.54 (2)) (I), EuAu 4(Au/In) 2 (EuAu 4+xIn 2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu 2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl 4Mo 2-type (tI14; I4/ mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed ofmore » an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au 8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu 2–“EuAu 4In 2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu 4(Au/In) 2” models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au–In contacts. Furthermore, a chemical bonding analysis on two “EuAu 5In” and “EuAu 4In 2” models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.« less

  6. From the ternary Eu(Au/In) 2 and EuAu 4(Au/In) 2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu 5Au 16(Au/In) 6 structure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Steinberg, Simon; Card, Nathan; Mudring, Anja -Verena

    The ternary Eu(Au/In) 2 (EuAu 0.46In 1.54 (2)) (I), EuAu 4(Au/In) 2 (EuAu 4+xIn 2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu 2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl 4Mo 2-type (tI14; I4/ mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed ofmore » an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au 8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu 2–“EuAu 4In 2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu 4(Au/In) 2” models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au–In contacts. Furthermore, a chemical bonding analysis on two “EuAu 5In” and “EuAu 4In 2” models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.« less

  7. Bonding properties of FCC-like Au 44 (SR) 28 clusters from X-ray absorption spectroscopy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Rui; Chevrier, Daniel M.; Zeng, Chenjie

    Thiolate-protected gold clusters with precisely controlled atomic composition have recently emerged as promising candidates for a variety of applications because of their unique optical, electronic, and catalytic properties. The recent discovery of the Au44(SR)28 total structure is considered as an interesting finding in terms of the face-centered cubic (FCC)-like core structure in small gold-thiolate clusters. Herein, the unique bonding properties of Au44(SR)28 is analyzed using temperature-dependent X-ray absorption spectroscopy (XAS) measurements at the Au L3-edge and compared with other FCC-like clusters such as Au36(SR)24 and Au28(SR)20. A negative thermal expansion was detected for the Au–Au bonds of the metal coremore » (the first Au–Au shell) and was interpreted based on the unique Au core structure consisting of the Au4 units. EXAFS fitting results from Au28(SR)20, Au36(SR)24, and Au44(SR)28 show a size-dependent negative thermal expansion behavior in the first Au–Au shell, further highlighting the importance of the Au4 units in determining the Au core bonding properties and shedding light on the growth mechanism of these FCC-like Au clusters.« less

  8. AuNx stabilization with interstitial nitrogen atoms: A Density Functional Theory Study

    NASA Astrophysics Data System (ADS)

    Quintero, J. H.; Gonzalez-Hernandez, R.; Ospina, R.; Mariño, A.

    2017-06-01

    Researchers have been studying 4d and 5d Series Transition Metal Nitrides lately as a result of the experimental production of AuN, PtN, CuN. In this paper, we used the Density Functional Theory (DFT) implementing a pseudopotential plane-wave method to study the incorporation of nitrogen atoms in the face-centered cube (fcc) lattice of gold (Au). First, we took the fcc structure of gold, and gradually located the nitrogen atoms in tetrahedral (TH) and octahedral (OH) interstitial sites. AuN stabilized in: 2OH (30%), 4OH and 4TH (50%), 4OH - 2TH (close to the wurtzite structure) and 6TH (60%). This leads us to think that AuN behaves like a Transition Metal Nitride since the nitrogen atoms look for tetrahedral sites.

  9. Cluster-to-cluster transformation among Au6, Au8 and Au11 nanoclusters.

    PubMed

    Ren, Xiuqing; Fu, Junhong; Lin, Xinzhang; Fu, Xuemei; Yan, Jinghui; Wu, Ren'an; Liu, Chao; Huang, Jiahui

    2018-05-22

    We present the cluster-to-cluster transformations among three gold nanoclusters, [Au6(dppp)4]2+ (Au6), [Au8(dppp)4Cl2]2+ (Au8) and [Au11(dppp)5]3+ (Au11). The conversion process follows a rule that states that the transformation of a small cluster to a large cluster is achieved through an oxidation process with an oxidizing agent (H2O2) or with heating, while the conversion of a large cluster to a small one occurs through a reduction process with a reducing agent (NaBH4). All the reactions were monitored using UV-Vis spectroscopy and ESI-MS. This work may provide an alternative approach to the synthesis of novel gold nanoclusters and a further understanding of the structural transformation relationship of gold nanoclusters.

  10. Interfacial nanodroplets guided construction of hierarchical Au, Au-Pt, and Au-Pd particles as excellent catalysts

    NASA Astrophysics Data System (ADS)

    Ma, Aijing; Xu, Jie; Zhang, Xuehua; Zhang, Bin; Wang, Dayang; Xu, Haolan

    2014-05-01

    Interfacial nanodroplets were grafted to the surfaces of self-sacrificed template particles in a galvanic reaction system to assist the construction of 3D Au porous structures. The interfacial nanodroplets were formed via direct adsorption of surfactant-free emulsions onto the particle surfaces. The interfacial nanodroplets discretely distributed at the template particle surfaces and served as soft templates to guide the formation of porous Au structures. The self-variation of footprint sizes of interfacial nanodroplets during Au growth gave rise to a hierarchical pore size distribution of the obtained Au porous particles. This strategy could be easily extended to synthesize bimetal porous particles such as Au-Pt and Au-Pd. The obtained porous Au, Au-Pt, and Au-Pd particles showed excellent catalytic activity in catalytic reduction of 4-nitrophenol.

  11. Au-Ag-Cu nano-alloys: tailoring of permittivity

    NASA Astrophysics Data System (ADS)

    Hashimoto, Yoshikazu; Seniutinas, Gediminas; Balčytis, Armandas; Juodkazis, Saulius; Nishijima, Yoshiaki

    2016-04-01

    Precious metal alloys enables new possibilities to tailor materials for specific optical functions. Here we present a systematic study of the effects of a nanoscale alloying on the permittivity of Au-Ag-Cu metals at 38 different atomic mixing ratios. The permittivity was measured and analyzed numerically by applying the Drude model. X-ray diffraction (XRD) revealed the face centered cubic lattice of the alloys. Both, optical spectra and XRD results point towards an equivalent composition-dependent electron scattering behavior. Correlation between the fundamental structural parameters of alloys and the resulting optical properties is elucidated. Plasmonic properties of the Au-Ag-Cu alloy nanoparticles were investigated by numerical simulations. Guidelines for designing plasmonic response of nano- structures and their patterns are presented from the material science perspective.

  12. Enzyme-Controlled Nanodevice for Acetylcholine-Triggered Cargo Delivery Based on Janus Au-Mesoporous Silica Nanoparticles.

    PubMed

    Llopis-Lorente, Antoni; Díez, Paula; de la Torre, Cristina; Sánchez, Alfredo; Sancenón, Félix; Aznar, Elena; Marcos, María D; Martínez-Ruíz, Paloma; Martínez-Máñez, Ramón; Villalonga, Reynaldo

    2017-03-28

    This work reports a new gated nanodevice for acetylcholine-triggered cargo delivery. We prepared and characterized Janus Au-mesoporous silica nanoparticles functionalized with acetylcholinesterase on the Au face and with supramolecular β-cyclodextrin:benzimidazole inclusion complexes as caps on the mesoporous silica face. The nanodevice is able to selectively deliver the cargo in the presence of acetylcholine via enzyme-mediated acetylcholine hydrolysis, locally lowering the pH and opening the supramolecular gate. Given the key role played by ACh and its relation with Parkinson's disease and other nervous system diseases, we believe that these findings could help design new therapeutic strategies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Atomistic insight into the adsorption site selectivity of stepped Au(111) surfaces

    NASA Astrophysics Data System (ADS)

    Gaspari, Roberto; Pignedoli, Carlo A.; Fasel, Roman; Treier, Matthias; Passerone, Daniele

    2010-07-01

    Using classical and ab initio simulations, we study the interplay between the Au(111) surface reconstruction and monoatomic steps on a vicinal face. The experimentally observed discommensuration line patterns on a specific vicinal are reproduced and explained, and a complete description of the structure is given. An unusual atomic arrangement is shown to be responsible for the lower reactivity of hcp segments of step edges compared to the one of fcc segments. Our results provide an unprecedented understanding of the electronic and geometric properties of the complex Au(111) surface.

  14. Suppression of Υ production in d + Au + and Au + Au collisions at √ sNN =200 GeV

    DOE PAGES

    None

    2014-07-01

    We report measurements of Upsilon meson production in p + p, d +Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p +p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y|more » < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state part on energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  15. DFT study on stability and H2 adsorption activity of bimetallic Au79-nPdn (n = 1-55) clusters

    NASA Astrophysics Data System (ADS)

    Liu, Xuejing; Tian, Dongxu; Meng, Changgong

    2013-03-01

    The stability and H2 adsorption activity of bimetallic Au79-nPdn (n = 1-55) clusters were studied by density functional theory with GGA-PW91 functional. The stability order for four Pd substitution types is face > mid-edge > corner > edge, and the stability is improved with increasing Pd content. In contrast with the stability order, H2 adsorption activity is corner ≈ edge > mid-edge > face. The Au36Pd43 (3) with Au:Pd ≈ 1:1 ratio and twenty-four Pd substitutions at (1 1 1) facets and nineteen Pd substitutions at subshell sites shows high stability and H2 non-activated dissociation activity. The partial density of d-states and d band center revealed that the electronic properties are closely associated with the geometric characteristic and adsorption activity. Correlating the d band center ɛd and the adsorption energies, the ɛd order agrees with the adsorption activity that the Pd substitution at edge and corner sites are more active than at face and mid-edge sites.

  16. Au-Ag-Cu nano-alloys: tailoring of permittivity

    PubMed Central

    Hashimoto, Yoshikazu; Seniutinas, Gediminas; Balčytis, Armandas; Juodkazis, Saulius; Nishijima, Yoshiaki

    2016-01-01

    Precious metal alloys enables new possibilities to tailor materials for specific optical functions. Here we present a systematic study of the effects of a nanoscale alloying on the permittivity of Au-Ag-Cu metals at 38 different atomic mixing ratios. The permittivity was measured and analyzed numerically by applying the Drude model. X-ray diffraction (XRD) revealed the face centered cubic lattice of the alloys. Both, optical spectra and XRD results point towards an equivalent composition-dependent electron scattering behavior. Correlation between the fundamental structural parameters of alloys and the resulting optical properties is elucidated. Plasmonic properties of the Au-Ag-Cu alloy nanoparticles were investigated by numerical simulations. Guidelines for designing plasmonic response of nano- structures and their patterns are presented from the material science perspective. PMID:27118459

  17. Chiral magnetic effect search in p+Au, d+Au and Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Zhao, Jie

    2018-01-01

    Metastable domains of fluctuating topological charges can change the chirality of quarks and induce local parity violation in quantum chromodynamics. This can lead to observable charge separation along the direction of the strong magnetic field produced by spectator protons in relativistic heavy-ion collisions, a phenomenon called the chiral magnetic effect (CME). A major background source for CME measurements using the charge-dependent azimuthal correlator (Δϒ) is the intrinsic particle correlations (such as resonance decays) coupled with the azimuthal elliptical anisotropy (v2). In heavy-ion collisions, the magnetic field direction and event plane angle are correlated, thus the CME and the v2-induced background are entangled. In this report, we present two studies from STAR to shed further lights on the background issue. (1) The Δϒ should be all background in small system p+Au and d+Au collisions, because the event plane angles are dominated by geometry fluctuations uncorrelated to the magnetic field direction. However, significant Δϒ is observed, comparable to the peripheral Au+Au data, suggesting a background dominance in the latter, and likely also in the mid-central Au+Au collisions where the multiplicity and v2 scaled correlator is similar. (2) A new approach is devised to study Δϒ as a function of the particle pair invariant mass (minv) to identify the resonance backgrounds and hence to extract the possible CME signal. Signal is consistent with zero within uncertainties at high minv. Signal at low minv, extracted from a two-component model assuming smooth mass dependence, is consistent with zero within uncertainties.

  18. Optical enhancement of Au doped ZrO2 thin films by sol-gel dip coating method

    NASA Astrophysics Data System (ADS)

    John Berlin, I.; Joy, K.

    2015-01-01

    Homogeneous and transparent Au doped ZrO2 thin films were prepared by sol-gel dip coating method. The films have mixed phase of tetragonal, monoclinic and face centered cubic with crack free surface. Due to the increase in Au doping concentration many-body interaction occurs between free carriers and ionized impurities causing decrease in optical band gap from 5.72 to 5.40 eV. Localized surface plasmon resonance peak of the Au doped films appeared at 610 nm. Conversion of photons to surface plasmons allows the sub-wavelength manipulation of electromagnetic radiation. Hence the prepared Au doped ZrO2 thin films can be applied in nanoscale photonic devices such as lenses, switches, waveguides etc. Moreover the photoluminescence (PL) intensity of Au doped ZrO2 thin films decrease due to decrease in the radiative recombination, life time of the excitons and suppression of grain growth of ZrO2 with increasing Au dopant.

  19. Large scale structural optimization of trimetallic Cu-Au-Pt clusters up to 147 atoms

    NASA Astrophysics Data System (ADS)

    Wu, Genhua; Sun, Yan; Wu, Xia; Chen, Run; Wang, Yan

    2017-10-01

    The stable structures of Cu-Au-Pt clusters up to 147 atoms are optimized by using an improved adaptive immune optimization algorithm (AIOA-IC method), in which several motifs, such as decahedron, icosahedron, face centered cubic, sixfold pancake, and Leary tetrahedron, are randomly selected as the inner cores of the starting structures. The structures of Cu8AunPt30-n (n = 1-29), Cu8AunPt47-n (n = 1-46), and partial 75-, 79-, 100-, and 147-atom clusters are analyzed. Cu12Au93Pt42 cluster has onion-like Mackay icosahedral motif. The segregation phenomena of Cu, Au and Pt in clusters are explained by the atomic radius, surface energy, and cohesive energy.

  20. Facet-controlled phase separation in supersaturated Au-Ni nanoparticles upon shape equilibration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Herz, A., E-mail: andreas.herz@tu-ilmenau.de, E-mail: dong.wang@tu-ilmenau.de; Rossberg, D.; Hentschel, M.

    2015-08-17

    Solid-state dewetting is used to fabricate supersaturated, submicron-sized Au-Ni solid solution particles out of thin Au/Ni bilayers by means of a rapid thermal annealing technique. Phase separation in such particles is studied with respect to their equilibrium crystal (or Wulff) shape by subsequent annealing at elevated temperature. It is found that (100) faceting planes of the equilibrated particles are enriched with Ni and (111) faces with Au. Both phases are considered by quantum-mechanical calculations in combination with an error-reduction scheme that was developed to compensate for a missing exchange-correlation potential that would reliably describe both Au and Ni. The observedmore » phase configuration is then related to the minimization of strongly anisotropic elastic energies of Au- and Ni-rich phases and results in a rather unique nanoparticle composite state that is characterized by nearly uniform value of elastic response to epitaxial strains all over the faceted surface. The same conclusion is yielded also by evaluating bi-axial elastic moduli when employing interpolated experimental elastic constants. This work demonstrates a useful route for studying features of physical metallurgy at the mesoscale.« less

  1. ZnS-Au planet-like structure: a facile fabrication and improved optical performance induced by surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Yang, Chaoshun; An, Guofei; Zhou, Yawei; Zhao, Xiaopeng

    2013-05-01

    Semiconductor-metal planet-like structure composed of ZnS crystals and Au nanoparticles (NPs) were successfully synthesized using a simple method. The external surface of ZnS was pre-modified with sodium dodecyl sulfate (SDS). With the assistance of this anionic surfactant, Au NPs could be deposited onto the surface of ZnS crystals via electrostatic adsorption. The samples were structurally characterized by X-ray diffraction, Fourier transform infrared, and transmission electron microscope. It was shown that all samples were made up of face-centered cubic Au and wurtzite ZnS. In this structure, the surface coverage of Au NPs could be readily adjusted by varying the Au/ZnS ratio during the synthesis. Photoluminescence results showed that the defect emission intensity of the ZnS-Au planet-like structure improved by 20 % at the Au/ZnS molar ratio of 1:588, with the Au NPs measuring 12 nm in diameter. This enhancement can be primarily ascribed to localized surface plasmon resonance on the surface of the Au NPs.

  2. Crystal Structure of Faradaurate-279: Au279(SPh-tBu)84 Plasmonic Nanocrystal Molecules.

    PubMed

    Sakthivel, Naga Arjun; Theivendran, Shevanuja; Ganeshraj, Vigneshraja; Oliver, Allen G; Dass, Amala

    2017-11-01

    We report the discovery of an unprecedentedly large, 2.2 nm diameter, thiolate protected gold nanocrystal characterized by single crystal X-ray crystallography (sc-XRD), Au 279 (SPh-tBu) 84 named Faradaurate-279 (F-279) in honor of Michael Faraday's (1857) pioneering work on nanoparticles. F-279 nanocrystal has a core-shell structure containing a truncated octahedral core with bulk face-centered cubic-like arrangement, yet a nanomolecule with a precise number of metal atoms and thiolate ligands. The Au 279 S 84 geometry was established from a low-temperature 120 K sc-XRD study at 0.90 Å resolution. The atom counts in core-shell structure of Au 279 follows the mathematical formula for magic number shells: Au@Au 12 @Au 42 @Au 92 @Au 54 , which is further protected by a final shell of Au 48 . Au 249 core is protected by three types of staple motifs, namely: 30 bridging, 18 monomeric, and 6 dimeric staple motifs. Despite the presence of such diverse staple motifs, Au 279 S 84 structure has a chiral pseudo-D 3 symmetry. The core-shell structure can be viewed as nested, concentric polyhedra, containing a total of five forms of Archimedean solids. A comparison between the Au 279 and Au 309 cuboctahedral superatom model in shell-wise growth is illustrated. F-279 can be synthesized and isolated in high purity in milligram quantities using size exclusion chromatography, as evidenced by mass spectrometry. Electrospray ionization-mass spectrometry independently verifies the X-ray diffraction study based heavy atoms formula, Au 279 S 84 , and establishes the molecular formula with the complete ligands, namely, Au 279 (SPh-tBu) 84 . It is also the smallest gold nanocrystal to exhibit metallic behavior, with a surface plasmon resonance band around 510 nm.

  3. Au38(SPh)24: Au38 Protected with Aromatic Thiolate Ligands.

    PubMed

    Rambukwella, Milan; Burrage, Shayna; Neubrander, Marie; Baseggio, Oscar; Aprà, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Dass, Amala

    2017-04-06

    Au 38 (SR) 24 is one of the most extensively investigated gold nanomolecules along with Au 25 (SR) 18 and Au 144 (SR) 60 . However, so far it has only been prepared using aliphatic-like ligands, where R = -SC 6 H 13 , -SC 12 H 25 and -SCH 2 CH 2 Ph. Au 38 (SCH 2 CH 2 Ph) 24 when reacted with HSPh undergoes core-size conversion to Au 36 (SPh) 24 , and existing literature suggests that Au 38 (SPh) 24 cannot be synthesized. Here, contrary to prevailing knowledge, we demonstrate that Au 38 (SPh) 24 can be prepared if the ligand exchanged conditions are optimized, under delicate conditions, without any formation of Au 36 (SPh) 24 . Conclusive evidence is presented in the form of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), electrospray ionization mass spectra (ESI-MS) characterization, and optical spectra of Au 38 (SPh) 24 in a solid glass form showing distinct differences from that of Au 38 (S-aliphatic) 24 . Theoretical analysis confirms experimental assignment of the optical spectrum and shows that the stability of Au 38 (SPh) 24 is not negligible with respect to that of its aliphatic analogous, and contains a significant component of ligand-ligand attractive interactions. Thus, while Au 38 (SPh) 24 is stable at RT, it converts to Au 36 (SPh) 24 either on prolonged etching (longer than 2 hours) at RT or when etched at 80 °C.

  4. Evidence of final-state suppression of high-p{_ T} hadrons in Au + Au collisions using d + Au measurements at RHIC

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.; Zhang, J.

    Transverse momentum spectra of charged hadrons with pT < 6 GeV/c have been measured near mid-rapidity (0.2 < ɛ < 1.4) by the PHOBOS experiment at RHIC in Au + Au and d + Au collisions at {√ {s{NN}} = {200 GeV}}. The spectra for different collision centralities are compared to {p + ¯ {p}} collisions at the same energy. The resulting nuclear modification factor for central Au + Au collisions shows evidence of strong suppression of charged hadrons in the high-pT region (>2 GeV/c). In contrast, the d + Au nuclear modification factor exhibits no suppression of the high-pT yields. These measurements suggest a large energy loss of the high-pT particles in the highly interacting medium created in the central Au + Au collisions. The lack of suppression in d + Au collisions suggests that it is unlikely that initial state effects can explain the suppression in the central Au + Au collisions. PACS: 25.75.-q

  5. Face-to-face stacks of trinuclear gold(I) trihalides with benzene, hexafluorobenzene, and borazine: impact of aromaticity on stacking interactions.

    PubMed

    Tsipis, Athanassios C; Stalikas, Alexandros V

    2013-01-18

    The interplay of electrostatics, charge transfer, and dispersion forces contributing to the interaction energies in 1:1, 1:2, and 2:1 binary stacks of the c-Au(3)(μ(2)-X)(3) (X = F, Cl, Br, I) clusters with benzene, hexafluorobenzene, or borazine were investigated by employing a multitude of electronic structure computational techniques. The molecular and electronic structures, stabilities, bonding features, and magnetotropicity of [c-Au(3)(μ(2)-X)(3)](n)(L)(m) (X = halide; L = C(6)H(6), C(6)F(6), B(3)N(3)H(6); n, m ≤ 2) columnar binary stacks have been investigated by DFT calculations employing the M05-2X functional. The novel binary stacks could be considered as the building blocks of extended columnar supramolecular assemblies formulated as {[c-Au(3)(μ(2)-X)(3)](C(6)H(6))}(∞), {[c-Au(3)(μ(2)-X)(3)](2)(C(6)F(6))}(∞), and {[c-Au(3)(μ(2)-X)(3)](B(3)N(3)H(6))(2)}(∞). In all binary stacks, with a few exceptions, the plane of the alternating c-Au(3)(μ(2)-X)(3) and L (C(6)H(6), C(6)F(6), B(3)N(3)H(6)) stacking participants adopt an almost parallel face-to-face (pff) orientation. The observed trends in the intermolecular distances R in the [c-Au(3)(μ(2)-X)(3)](n)(L)(m) (X = halide; L = C(6)H(6), C(6)F(6), B(3)N(3)H(6); n, m ≤ 2) columnar binary stacks are explained by the diverse intermolecular interactions characterizing the stacks, since the three ligands L and the c-Au(3)(μ(2)-X)(3) cyclic trinuclear clusters (CTCs) exhibit diverse physical properties being important determinants of the intermolecular interactions (consisting of covalent, electrostatic, and dispersion forces). The properties considered are the zz tensor components of quadrupole moment, Q(zz), polarizability, α(zz), nucleus-independent chemical shift, NICS(zz)(1), along with the molecular electrostatic potential, MEP(0), and surface area (S). Energy decomposition analysis (EDA) at the revPBE-D3/TZ2P level revealed that the dominant term in the stacking interactions arises mainly

  6. 3D morphology of Au and Au@Ag nanobipyramids

    NASA Astrophysics Data System (ADS)

    Burgin, Julien; Florea, Ileana; Majimel, Jérôme; Dobri, Adam; Ersen, Ovidiu; Tréguer-Delapierre, Mona

    2012-02-01

    The morphologies of Au and Au@Ag nanobipyramids were investigated using electron tomography. The 3D reconstruction reveals that the Au bipyramids have an irregular six-fold twinning structure with highly stepped dominant {151} facets. These short steps/edges stabilized via surface adsorbed CTAB favor the growth of silver on the lateral facets leading to strong blue shifts in longitudinal plasmon surface resonance.The morphologies of Au and Au@Ag nanobipyramids were investigated using electron tomography. The 3D reconstruction reveals that the Au bipyramids have an irregular six-fold twinning structure with highly stepped dominant {151} facets. These short steps/edges stabilized via surface adsorbed CTAB favor the growth of silver on the lateral facets leading to strong blue shifts in longitudinal plasmon surface resonance. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr11454b

  7. Structure Determination of Au on Pt(111) Surface: LEED, STM and DFT Study

    PubMed Central

    Krupski, Katarzyna; Moors, Marco; Jóźwik, Paweł; Kobiela, Tomasz; Krupski, Aleksander

    2015-01-01

    Low-energy electron diffraction (LEED), scanning tunneling microscopy (STM) and density functional theory (DFT) calculations have been used to investigate the atomic and electronic structure of gold deposited (between 0.8 and 1.0 monolayer) on the Pt(111) face in ultrahigh vacuum at room temperature. The analysis of LEED and STM measurements indicates two-dimensional growth of the first Au monolayer. Change of the measured surface lattice constant equal to 2.80 Å after Au adsorption was not observed. Based on DFT, the distance between the nearest atoms in the case of bare Pt(111) and Au/Pt(111) surface is equal to 2.83 Å, which gives 1% difference in comparison with STM values. The first and second interlayer spacing of the clean Pt(111) surface are expanded by +0.87% and contracted by −0.43%, respectively. The adsorption energy of the Au atom on the Pt(111) surface is dependent on the adsorption position, and there is a preference for a hollow fcc site. For the Au/Pt(111) surface, the top interlayer spacing is expanded by +2.16% with respect to the ideal bulk value. Changes in the electronic properties of the Au/Pt(111) system below the Fermi level connected to the interaction of Au atoms with Pt(111) surface are observed.

  8. Effects of Au content on the structure and magnetic properties of L1{sub 0}-FePt nanoparticles synthesized by the sol–gel method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Yang; Institute of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013; Jiang, Yuhong

    2014-07-01

    (FePt){sub 100−x}Au{sub x} (x=0, 5, 10, and 20) nanoparticles were synthesized by the sol–gel method, and effects of Au content on the structural and magnetic properties of samples were investigated. Au doping reduced the phase transition temperature from face-centered cubic (FCC) to face-centered tetragonal (FCT) structure. In addition, additive Au promotes the chemical ordering of L1{sub 0} FePt NPs and increases the grain size of L1{sub 0} FePt NPs. When Au content increased from 0 to 10 at%, the coercivity (H{sub c}) increased due to the increase in degree of ordering S and grain size of L1{sub 0} FePt NPs.more » By increasing the Au content to 20 at%, H{sub c} decreased. - Graphical abstract: (FePt){sub 100}Au{sub 0} NPs are the coexistence of FCT and FCC phases. However, no hints of FCC phase were found for the (FePt){sub 100−x}Au{sub x} NPs (x=5, 10 and 20), which indicates that addition of gold greatly promotes the FCC to FCT phase transition. - Highlights: • (FePt){sub 100−x}Au{sub x} (x=0, 5, 10 and 20) nanoparticles (NPs) were synthesized. • Au addition promotes the chemical ordering of L1{sub 0} FePt NPs. • Au addition reduces ordering temperature of L1{sub 0} FePt NPs from FCC to FCT phase. • (FePt){sub 90}Au{sub 10} NPs show a high coercivity of 9585 Oe at room temperature.« less

  9. Au/Graphene Oxide Nanocomposite Synthesized in Supercritical CO2 Fluid as Energy Efficient Lubricant Additive.

    PubMed

    Meng, Yuan; Su, Fenghua; Chen, Yangzhi

    2017-11-15

    Au nanoparticles are successfully decorated onto graphene oxide (GO) sheets with the aid of supercritical carbon dioxide (ScCO 2 ) fluid. The synthesized nanocomposite (Sc-Au/GO) was characterized by X-ray diffraction (XRD), Raman spectroscopy, thermal gravimetric analysis (TGA), and transmission electron microscopy (TEM). The characterization results show that the Au nanoparticles are featured with face-centered cubic crystal structure and disperse well on the GO nanosheet surfaces with average diameters of 4-10 nm. The tribological behaviors of Sc-Au/GO as lubricating additive in PAO6 oil were investigated using a ball-on-disc friction tester, and a control experiment by respectively adding GO, nano-Au particles, and Au/GO produced in the absence of ScCO 2 was performed as well. It is found that Sc-Au/GO exhibits the best lubricating performances among all the samples tested. When 0.10 wt % Sc-Au/GO is dispersed into PAO6 oil, the friction coefficient and wear rate are respectively reduced by 33.6% and 72.8% as compared to that of the pure PAO6 oil, indicating that Sc-Au/GO is an energy efficient lubricant additive. A possible lubricating mechanism of Sc-Au/GO additive in PAO6 oil has been tentatively proposed on the basis of the analyzed results of the worn surface examined by scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS).

  10. Controlling the Growth of Au on Icosahedral Seeds of Pd by Manipulating the Reduction Kinetics

    DOE PAGES

    Lv, Tian; Yang, Xuan; Zheng, Yiqun; ...

    2016-03-29

    This article reports a systematic study of how Au atoms nucleate and grow on Pd icosahedral seeds with a multiply twinned structure. By manipulating the reduction kinetics, we obtained Pd–Au bimetallic nanocrystals with two distinct shapes and structures. Specifically, Pd@Au core–shell icosahedra were formed when a relatively fast reduction rate was used for the HAuCl 4 precursor. At a slow reduction rate, in contrast, the nucleation and growth of Au atoms were mainly confined to one of the vertices of a Pd icosahedral seed, resulting in the formation of a Au icosahedron by sharing five adjacent faces with the Pdmore » seed. The same growth pattern was observed for Pd icosahedral seeds with both sizes of 32 and 20 nm. Also, we have also investigated the effects of other kinetic parameters, including the concentration of reducing agent and reaction temperature, on the growth pathway undertaken by the Au atoms. In conclusion, we believe that the mechanistic insights obtained from this study can be extended to other systems, including the involvement of different metals and/or seeds with different morphologies.« less

  11. Air Current Applied to the Face Improves Exercise Performance in Patients with COPD.

    PubMed

    Marchetti, Nathaniel; Lammi, Matthew R; Travaline, John M; Ciccolella, David; Civic, Brian; Criner, Gerard J

    2015-10-01

    Improving dyspnea and exercise performance are goals of COPD therapy. We tested the hypothesis that air current applied to the face would lessen dyspnea and improve exercise performance in moderate-severe COPD patients. We recruited 10 COPD patients (5 men, age 62 ± 6 years, FEV1 0.93 ± 0.11 L (34 ± 3% predicted), TLC 107 ± 6%, RV 172 ± 18%) naïve to the study hypothesis. Each patient was randomized in a crossover fashion to lower extremity ergometry at constant submaximal workload with a 12-diameter fan directed at the patients face or exposed leg. Each patients' studies were separated by at least 1 week. Inspiratory capacity and Borg dyspnea score were measured every 2 min and at maximal exercise. Total exercise time was longer when the fan was directed to the face (14.3 ± 12 vs. 9.4 ± 7.6 min, face vs. leg, respectively, p = 0.03). Inspiratory capacity tended to be greater with the fan directed to the face (1.4 (0.6-3.25) vs. 1.26 (0.56-2.89) L, p = 0.06). There was a reduction in dynamic hyperinflation, as reflected by higher IRV area in the fan on face group (553 ± 562 a.u. vs. 328 ± 319 a.u., p = 0.047). There was a significant improvement in the Borg dyspnea score at maximal exercise (5.0 (0-10) vs. 6.5 (0-10), p = 0.03), despite exercising for 34 % longer with the fan directed to the face. Air current applied to the face improves exercise performance in COPD. Possible mechanisms include an alteration in breathing pattern that diminishes development of dynamic hyperinflation or to a change in perception of breathlessness.

  12. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, T.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, W.; Li, Z. M.; Li, Y.; Li, C.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Ma, R.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, Z.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, F.; Wang, H.; Wang, G.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, H.; Xu, Z.; Xu, Q. H.; Xu, Y. F.; Xu, N.; Yang, S.; Yang, Y.; Yang, Q.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Y.; Zhang, Z.; Zhang, J. B.; Zhang, J.; Zhang, X. P.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.

    2015-12-01

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.

  13. Connected Au network in annealed Ni/Au thin films on p-GaN

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, S. P.; Jang, H. W.; Noh, D. Y.

    2007-11-12

    We report the formation of a connected Au network in annealed Ni/Au thin films on p-GaN, which was studied by scanning electron microscopy, transmission electron microscopy, and synchrotron x-ray diffraction. As the Ni was oxidized into NiO upon annealing at 530 deg. C in air, the Au layer was transformed to an interconnected network with an increased thickness. During annealing, Ni atoms diffuse out onto the Au through defects to form NiO, while Au atoms replace the Ni positions. The Au network grows downward until it reaches the p-GaN substrate, and NiO columns fill the space between the Au network.

  14. "The Open Library at AU" (Athabasca University): Supporting Open Access and Open Educational Resources

    ERIC Educational Resources Information Center

    Elliott, Colin; Fabbro, Elaine

    2015-01-01

    To address challenges that learners, course creators, librarians and academics involved with OER and MOOCs are facing when looking for scholarly materials, Athabasca University Library has initiated the development of "the Open Library at AU." This open library is a full library website that provides easy access to open and free…

  15. Plasmon-enhanced versatile optical nonlinearities in a Au-Ag-Au multi-segmental hybrid structure.

    PubMed

    Yao, Lin-Hua; Zhang, Jun-Pei; Dai, Hong-Wei; Wang, Ming-Shan; Zhang, Lu-Man; Wang, Xia; Han, Jun-Bo

    2018-06-27

    A Au-Ag-Au multi-segmental hybrid structure has been synthesized by using an electrodeposition method based on an anodic aluminum oxide (AAO) membrane. The third-order optical nonlinearities, second harmonic generation (SHG) and photoluminescence (PL) properties containing ultrafast supercontinuum generation and plasmon mediated thermal emission have been investigated. Significant optical enhancements have been obtained near surface plasmon resonance wavelength in all the abovementioned nonlinear processes. Comparative studies between the Au-Ag-Au multi-segmental hybrid structure and the corresponding single-component Au and Ag hybrid structures demonstrate that the Au-Ag-Au multi-segmental hybrid structure has much larger optical nonlinearities than its counterparts. These results demonstrate that the Au-Ag-Au hybrid structure is a promising candidate for applications in plasmonic devices and enhancement substrates.

  16. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    DOE PAGES

    Adamczyk, L.

    2015-10-23

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher formore » leading non-pions than pions. As a result, the consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.« less

  17. Biosynthesis and stabilization of Au and Au Ag alloy nanoparticles by fungus, Fusarium semitectum

    NASA Astrophysics Data System (ADS)

    Dasaratrao Sawle, Balaji; Salimath, Basavaraja; Deshpande, Raghunandan; Dhondojirao Bedre, Mahesh; Krishnamurthy Prabhakar, Belawadi; Venkataraman, Abbaraju

    2008-09-01

    Crystallized and spherical-shaped Au and Au-Ag alloy nanoparticles have been synthesized and stabilized using a fungus, F . semitectum in an aqueous system. Aqueous solutions of chloroaurate ions for Au and chloroaurate and Ag+ ions (1 : 1 ratio) for Au-Ag alloy were treated with an extracellular filtrate of F . semitectum biomass for the formation of Au nanoparticles (AuNP) and Au-Ag alloy nanoparticles (Au-AgNP). Analysis of the feasibility of the biosynthesized nanoparticles and core-shell alloy nanoparticles from fungal strains is particularly significant. The resultant colloidal suspensions are highly stable for many weeks. The obtained Au and Au-Ag alloy nanoparticles were characterized by the surface plasmon resonance (SPR) peaks using a UV-vis spectrophotometer, and the structure, morphology and size were determined by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and transmission electron microscopy (TEM). Possible optoelectronics and medical applications of these nanoparticles are envisaged.

  18. Generalized-stacking-fault energy and twin-boundary energy of hexagonal close-packed Au: A first-principles calculation.

    PubMed

    Wang, Cheng; Wang, Huiyuan; Huang, Tianlong; Xue, Xuena; Qiu, Feng; Jiang, Qichuan

    2015-05-22

    Although solid Au is usually most stable as a face-centered cubic (fcc) structure, pure hexagonal close-packed (hcp) Au has been successfully fabricated recently. However, the phase stability and mechanical property of this new material are unclear, which may restrict its further applications. Here we present the evidence that hcp → fcc phase transformation can proceed easily in Au by first-principles calculations. The extremely low generalized-stacking-fault (GSF) energy in the basal slip system implies a great tendency to form basal stacking faults, which opens the door to phase transformation from hcp to fcc. Moreover, the Au lattice extends slightly within the superficial layers due to the self-assembly of alkanethiolate species on hcp Au (0001) surface, which may also contribute to the hcp → fcc phase transformation. Compared with hcp Mg, the GSF energies for non-basal slip systems and the twin-boundary (TB) energies for and twins are larger in hcp Au, which indicates the more difficulty in generating non-basal stacking faults and twins. The findings provide new insights for understanding the nature of the hcp → fcc phase transformation and guide the experiments of fabricating and developing materials with new structures.

  19. Fermi surfaces properties of AuAl2, AuGa2, and AuIn2 with the CaF2-type cubic structure

    NASA Astrophysics Data System (ADS)

    Nishimura, K.; Kakihana, M.; Suzuki, F.; Yara, T.; Hedo, M.; Nakama, T.; Ōnuki, Y.; Harima, H.

    2018-05-01

    We grew high-quality single crystals of AuAl2, AuGa2, and AuIn2 with the fluorite (CaF2)-type cubic structure and determined the Fermi surface properties by the de Haas-van Alphen (dHvA) experiments using full-potential LAPW bad calculations. The Fermi surface and optical properties for three compounds were once studied from an interest of colors because AuAl2 has a striking bright reddish-purple color, whereas AuGa2 and AuIn2 are, respectively, neutral and bluish. The detected dHvA frequencies in the present study are found to be in a wide range of (0.1-13)×107 Oe. The main dHvA branches for three compounds are in excellent agreement with the theoretical ones, but some dHvA branches with small dHvA frequencies are slightly deviated from the theoretical ones, especially in AuGa2 and AuIn2.

  20. Effects of correcting missing daily feed intake values on the genetic parameters and estimated breeding values for feeding traits in pigs.

    PubMed

    Ito, Tetsuya; Fukawa, Kazuo; Kamikawa, Mai; Nikaidou, Satoshi; Taniguchi, Masaaki; Arakawa, Aisaku; Tanaka, Genki; Mikawa, Satoshi; Furukawa, Tsutomu; Hirose, Kensuke

    2018-01-01

    Daily feed intake (DFI) is an important consideration for improving feed efficiency, but measurements using electronic feeder systems contain many missing and incorrect values. Therefore, we evaluated three methods for correcting missing DFI data (quadratic, orthogonal polynomial, and locally weighted (Loess) regression equations) and assessed the effects of these missing values on the genetic parameters and the estimated breeding values (EBV) for feeding traits. DFI records were obtained from 1622 Duroc pigs, comprising 902 individuals without missing DFI and 720 individuals with missing DFI. The Loess equation was the most suitable method for correcting the missing DFI values in 5-50% randomly deleted datasets among the three equations. Both variance components and heritability for the average DFI (ADFI) did not change because of the missing DFI proportion and Loess correction. In terms of rank correlation and information criteria, Loess correction improved the accuracy of EBV for ADFI compared to randomly deleted cases. These findings indicate that the Loess equation is useful for correcting missing DFI values for individual pigs and that the correction of missing DFI values could be effective for the estimation of breeding values and genetic improvement using EBV for feeding traits. © 2017 The Authors. Animal Science Journal published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Animal Science.

  1. Tailoring characteristic thermal stability of Ni-Au binary nanocrystals via structure and composition engineering: theoretical insights into structural evolution and atomic inter-diffusion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Bangquan; Wang, Hailong; Xing, Guozhong

    We report on the structural evolution and atomic inter-diffusion characteristics of the bimetallic Ni-Au nanocrystals (NCs) by molecular dynamics simulations studies. Our results reveal that the thermal stability dynamics of Ni-Au NCs strongly depends on the atomic configurations. By engineering the structural construction with Ni:Au = 1:1 atomic composition, compared with core-shell Au@Ni and alloy NCs, the melting point of core-shell Ni@Au NCs is significantly enhanced up to 1215 K. Unexpectedly, with atomic ratio of Au:Ni= 1:9, the melting process initiates from the atoms in the shell of Ni@Au and alloy NCs, while starts from the core of Au@Ni NCs.more » The corresponding features and evolution process of structural motifs, mixing and segregation are illustrated via a series of dynamic simulations videos. Moreover, our results revealed that the face centered cubic phase Au{sub 0.75}Ni{sub 0.25} favorably stabilizes in NCs form but does not exist in the bulk counterpart, which elucidates the anomalies of previously reported experimental results on such bimetallic NCs.« less

  2. How Does Amino Acid Ligand Modulate Au Core Structure and Characteristics in Peptide Coated Au Nanocluster?

    PubMed

    Li, Nan; Li, Xu; Zhao, Hongkang; Zhao, Lina

    2018-03-01

    The atomic structures and the corresponding physicochemical properties of peptide coated Au nanoclusters determine their distinctive biological targeting applications. To learn the modulation of amino acid ligand on the atomic structure and electronic characteristics of coated Au core is the fundamental knowledge for peptide coated Au nanocluster design and construction. Based on our recent coated Au nanocluster configuration study (Nanoscale, 2016, 8, 11454), we built the typically simplified Au13(Cys-Au-Cys) system to more clearly learn the basic modulation information of amino acid ligand on Au core by the density functional theory (DFT) calculations. There are two isomers as ligand adjacent bonding (Iso1) and diagonal bonding (Iso2) to Au13 cores. The geometry optimizations indicate the adjacent bonding Iso1 is more stable than Iso2. More important, the Au13 core of Iso1 distorts much more significantly than that of Iso2 by Cys-Au-Cys bonding through the root-mean-square deviation (RMSD) analysis, which modulate their electronic characteristics in different ways. In addition, the frontier molecular orbital results of Au13(Cys-Au-Cys) isomers confirm that the Au cores mainly determine the blue shifts of Au13(Cys-Au-Cys) systems versus the original Au13 core in their UV-visible absorption spectrum studies. The configuration of Au13 core performs deformation under Cys-Au-Cys ligand modulation to reach new stability with distinct atomic structure and electronic properties, which could be the theory basis for peptide coated AuNCs design and construction.

  3. Comparison of the space-time extent of the emission source in d +Au and Au + Au collisions at √{sNN} = 200 GeV

    NASA Astrophysics Data System (ADS)

    Ajitanand, N. N.; Phenix Collaboration

    2014-11-01

    Two-pion interferometry measurements in d +Au and Au + Au collisions at √{sNN} = 200 GeV are used to extract and compare the Gaussian source radii Rout, Rside and Rlong, which characterize the space-time extent of the emission sources. The comparisons, which are performed as a function of collision centrality and the mean transverse momentum for pion pairs, indicate strikingly similar patterns for the d +Au and Au + Au systems. They also indicate a linear dependence of Rside on the initial transverse geometric size R bar , as well as a smaller freeze-out size for the d +Au system. These patterns point to the important role of final-state re-scattering effects in the reaction dynamics of d +Au collisions.

  4. Au/Ti resistors used for Nb/Pb-alloy Josephson junctions. II. Thermal stability

    NASA Astrophysics Data System (ADS)

    Murakami, Masanori; Kim, K. K.

    1984-10-01

    In the preceding paper bilayered Au/Ti resistors were found to have excellent electrical stability during storage at room temperature after preannealing at an elevated temperature, which is essential to design logic and memory circuits of Nb/Pb-alloy Josephson junction devices. The resistors could contact directly with the Pb-alloy control lines in which Pb and In atoms which are known to intermix easily with Au atoms are contained. Since Pb and In atoms in the control lines are separated from Au atoms of the resistors by thin Ti layers, thermal stability at the contacts is a major concern for use of the Au/Ti resistor material in the Josephson devices. In the present study, surface morphology change and diffusion mechanism at the resistor/control-line contacts were studied using x-ray diffraction and scanning electron microscopy for square-shaped Au/Ti resistors covered by Pb-In layers. The samples were isothermally annealed at temperatures ranging from 353 to 423 K. The diffusion did not occur immediately after annealing at these temperatures. After the incubation period, the interdiffusion was observed to initiate at the edges of the resistors facing to the center of the cathode. Significant amounts of the In atoms in the Pb-In layers were observed to diffuse into the Au layers of the resistors, forming AuIn2 compounds under the Ti layers. By measuring growth rates of the AuIn2 layers, the diffusion coefficients and the activation energy for the layer growth were determined. Also, by analyzing changes in the In concentration in the Pb-In layers during annealing, interdiffusion coefficients of In atoms in the Pb-In layers were determined using a computer simulation technique. The activation energy was about 1.1 eV. Since these diffusion coefficients were found to be very close to those determined previously in bulk materials, the diffusion kinetics is believed to be controlled by the lattice diffusion. Based on the present results, several methods to reduce the

  5. Nanoscale thin film growth of Au on Si(111)-7 × 7 surface by pulsed laser deposition method

    NASA Astrophysics Data System (ADS)

    Yokotani, Atsushi; Kameyama, Akihiro; Nakayoshi, Kohei; Matsunaga, Yuta

    2017-03-01

    To obtain important information for fabricating atomic-scale Au thin films that are used for biosensors, we have observed the morphology of Au particles adsorbed on a Si(111)-7 × 7 surface, which is supposed to be the initial stage of Au atomistic thin film formation. Au particles were adsorbed on the clean Si surface using a PLD method, and the adsorbed particles were observed using a scanning tunneling microscope. As the number of laser shots was increased in the PLD method, the size of the adsorbed particle became larger. The larger particles seemed to form clusters, which are aggregations of particles in which each particle is distinguished, so we call this type of cluster a film-shaped cluster. In this work, we have mainly analyzed this type of cluster. As a result the film-shaped clusters were found to have a structure of nearly monoatomic layers. The particles in the clusters were gathered closely in roughly a 3-fold structure with an inter particle distance of 0.864 nm. We propose a model for the cluster structure by modifying Au(111) face so that each observed particle consists of three Au atoms.

  6. The extraction characteristic of Au-Ag from Au concentrate by thiourea solution

    NASA Astrophysics Data System (ADS)

    Kim, Bongju; Cho, Kanghee; On, Hyunsung; Choi, Nagchoul; Park, Cheonyoung

    2013-04-01

    The cyanidation process has been used commercially for the past 100 years, there are ores that are not amenable to treatment by cyanide. Interest in alternative lixiviants, such as thiourea, halogens, thiosulfate and malononitrile, has been revived as a result of a major increase in gold price, which has stimulated new developments in extraction technology, combined with environmental concern. The Au extraction process using the thiourea solvent has many advantages over the cyanidation process, including higher leaching rates, faster extraction time and less than toxicity. The purpose of this study was investigated to the extraction characteristic of Au-Ag from two different Au concentrate (sulfuric acid washing and roasting) under various experiment conditions (thiourea concentration, pH of solvent, temperature) by thiourea solvent. The result of extraction experiment showed that the Au-Ag extraction was a fast extraction process, reaching equilibrium (maximum extraction rate) within 30 min. The Au-Ag extraction rate was higher in the roasted concentrate than in the sulfuric acid washing. The higher the Au-Ag extraction rate (Au - 70.87%, Ag - 98.12%) from roasted concentrate was found when the more concentration of thiourea increased, pH decreased and extraction temperature increased. This study informs extraction method basic knowledge when thiourea was a possibility to eco-/economic resources of Au-Ag utilization studies including the hydrometallurgy.

  7. Structure-activity relationships in cytotoxic Au(I)/Au(III) complexes derived from 2-(2'-pyridyl)benzimidazole.

    PubMed

    Maiore, Laura; Aragoni, Maria Carla; Deiana, Carlo; Cinellu, Maria Agostina; Isaia, Francesco; Lippolis, Vito; Pintus, Anna; Serratrice, Maria; Arca, Massimiliano

    2014-04-21

    Gold(I) and gold(III) complexes derived from 2-(2'-pyridyl)benzimidazole (pbiH) were proven to be a promising class of in vitro antitumor agents against A2780 human ovarian cancer cells. In this paper, a comparative electrochemical, UV-vis absorption, and emission spectroscopic investigation is reported on pbiH, the two mononuclear Au(III) complexes [(pbi)AuX2] (X = Cl (1), AcO (2)), the four mononuclear Au(I) derivatives [(pbiH)AuCl] (3), [(pbiH)Au(PPh3)]PF6 ((4(+))(PF6(-))), [(pbi)Au(PPh3)] (5), and [(pbi)Au(TPA)] (6), the three mixed-valence Au(III)/Au(I) complexes [(μ-pbi)Au2Cl3] (7), [(Ph3P)Au(μ-pbi)AuX2]PF6 (X = Cl ((8(+))(PF6(-))), AcO ((9(+))(PF6(-)))), and the binuclear Au(I)-Au(I) compound [(μ-pbi)Au2(PPh3)2]PF6 ((10(+))(PF6(-))). All complexes feature irreversible reduction processes related to the Au(III)/Au(I) or Au(I)/Au(0) processes and peculiar luminescent emission at about 360-370 nm in CH2Cl2, with quantum yields that are remarkably lower ((0.7-14.5) × 10(-2)) in comparison to that determined for the free pbiH ligand (31.5 × 10(-2)) in the same solvent. The spectroscopic and electrochemical properties of all complexes were interpreted on the grounds of time-dependent PBE0/DFT calculations carried out both in the gas phase and in CH2Cl2 implicitly considered within the IEF-PCM SCRF approach. The electronic structure of the complexes, and in particular the energy and composition of the Kohn-Sham LUMOs, can be related to the antiproliferative properties against the A2780 ovarian carcinoma cell line, providing sound quantitative structure-activity relationships and shedding a light on the role played by the global charge and nature of ancillary ligands in the effectiveness of Au-based antitumor drugs.

  8. Mesoscopic self-organization of a self-assembled supramolecular rectangle on highly oriented pyrolytic graphite and Au(111) surfaces.

    PubMed

    Gong, Jian-Ru; Wan, Li-Jun; Yuan, Qun-Hui; Bai, Chun-Li; Jude, Hershel; Stang, Peter J

    2005-01-25

    A self-assembled supramolecular metallacyclic rectangle was investigated with scanning tunneling microscopy on highly oriented pyrolytic graphite and Au(111) surfaces. The rectangles spontaneously adsorb on both surfaces and self-organize into well ordered adlayers. On highly oriented pyrolytic graphite, the long edge of the rectangle stands on the surface, forming a 2D molecular network. In contrast, the face of the rectangle lays flat on the Au(111) surface, forming linear chains. The structures and intramolecular features obtained through high-resolution scanning tunneling microscopy imaging are discussed.

  9. Generalized-stacking-fault energy and twin-boundary energy of hexagonal close-packed Au: A first-principles calculation

    PubMed Central

    Wang, Cheng; Wang, Huiyuan; Huang, Tianlong; Xue, Xuena; Qiu, Feng; Jiang, Qichuan

    2015-01-01

    Although solid Au is usually most stable as a face-centered cubic (fcc) structure, pure hexagonal close-packed (hcp) Au has been successfully fabricated recently. However, the phase stability and mechanical property of this new material are unclear, which may restrict its further applications. Here we present the evidence that hcp → fcc phase transformation can proceed easily in Au by first-principles calculations. The extremely low generalized-stacking-fault (GSF) energy in the basal slip system implies a great tendency to form basal stacking faults, which opens the door to phase transformation from hcp to fcc. Moreover, the Au lattice extends slightly within the superficial layers due to the self-assembly of alkanethiolate species on hcp Au (0001) surface, which may also contribute to the hcp → fcc phase transformation. Compared with hcp Mg, the GSF energies for non-basal slip systems and the twin-boundary (TB) energies for and twins are larger in hcp Au, which indicates the more difficulty in generating non-basal stacking faults and twins. The findings provide new insights for understanding the nature of the hcp → fcc phase transformation and guide the experiments of fabricating and developing materials with new structures. PMID:25998415

  10. Charged hadron transverse momentum distributions in Au+Au collisions at S=200 GeV

    NASA Astrophysics Data System (ADS)

    Roland, Christof; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2003-03-01

    We present transverse momentum distributions of charged hadrons produced in Au+Au collisions at sqrt(s_NN) = 200 GeV. The evolution of the spectra for transverse momenta p_T from 0.25 to 5GeV/c is studied as a function of collision centrality over a range from 65 to 344 participating nucleons. We find a significant change of the spectral shape between proton-antiproton and peripheral Au+Au collisions. Comparing peripheral to central Au+Au collisions, we find that the yields at the highest p_T exhibit approximate scaling with the number of participating nucleons, rather than scaling with the number of binary collisions.

  11. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

    DOE PAGES

    Adamczyk, L.

    2015-04-01

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore » rapidity range |y| < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  12. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adamczyk, L.

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore » rapidity range |y| < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  13. Diphosphine-protected ultrasmall gold nanoclusters: opened icosahedral Au 13 and heart-shaped Au 8 clusters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Shan-Shan; Feng, Lei; Senanayake, Ravithree D.

    Two ultrasmall gold clusters, Au 13 and Au 8 , were identified as a distorted I h icosahedral Au 13 and edge-shared “core + 4 exo ” structure Au 8 S 2 cores, respectively. They showed interesting luminescence and electrochemical properties.

  14. Diphosphine-protected ultrasmall gold nanoclusters: opened icosahedral Au 13 and heart-shaped Au 8 clusters

    DOE PAGES

    Zhang, Shan-Shan; Feng, Lei; Senanayake, Ravithree D.; ...

    2018-01-01

    Two ultrasmall gold clusters, Au 13 and Au 8 , were identified as a distorted I h icosahedral Au 13 and edge-shared “core + 4 exo ” structure Au 8 S 2 cores, respectively. They showed interesting luminescence and electrochemical properties.

  15. Controlling the stereochemistry and regularity of butanethiol self-assembled monolayers on au(111).

    PubMed

    Yan, Jiawei; Ouyang, Runhai; Jensen, Palle S; Ascic, Erhad; Tanner, David; Mao, Bingwei; Zhang, Jingdong; Tang, Chunguang; Hush, Noel S; Ulstrup, Jens; Reimers, Jeffrey R

    2014-12-10

    The rich stereochemistry of the self-assembled monolayers (SAMs) of four butanethiols on Au(111) is described, the SAMs containing up to 12 individual C, S, or Au chiral centers per surface unit cell. This is facilitated by synthesis of enantiomerically pure 2-butanethiol (the smallest unsubstituted chiral alkanethiol), followed by in situ scanning tunneling microscopy (STM) imaging combined with density functional theory molecular dynamics STM image simulations. Even though butanethiol SAMs manifest strong headgroup interactions, steric interactions are shown to dominate SAM structure and chirality. Indeed, steric interactions are shown to dictate the nature of the headgroup itself, whether it takes on the adatom-bound motif RS(•)Au(0)S(•)R or involves direct binding of RS(•) to face-centered-cubic or hexagonal-close-packed sites. Binding as RS(•) produces large, organizationally chiral domains even when R is achiral, while adatom binding leads to rectangular plane groups that suppress long-range expression of chirality. Binding as RS(•) also inhibits the pitting intrinsically associated with adatom binding, desirably producing more regularly structured SAMs.

  16. Identified particle distributions in pp and Au+Au collisions atsqrt sNN=200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adams, J.; Adler, C.; Aggarwal, M.M.

    2003-10-06

    Transverse mass and rapidity distributions for charged pions, charged kaons, protons and antiprotons are reported for {radical}sNN = 200 GeV pp and Au+Au collisions at RHIC. The transverse mass distributions are rapidity independent within |y| < 0.5, consistent with a boost-invariant system in this rapidity interval. Spectral shapes and relative particle yields are similar in pp and peripheral Au+Au collisions and change smoothly to central Au+Au collisions. No centrality dependence was observed in the kaon and antiproton production rates relative to the pion production rate from medium-central to central collisions. Chemical and kinetic equilibrium model fits to our data revealmore » strong radial flow and relatively long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.« less

  17. Quasi-Dual-Packed-Kerneled Au49 (2,4-DMBT)27 Nanoclusters and the Influence of Kernel Packing on the Electrochemical Gap.

    PubMed

    Liao, Lingwen; Zhuang, Shengli; Wang, Pu; Xu, Yanan; Yan, Nan; Dong, Hongwei; Wang, Chengming; Zhao, Yan; Xia, Nan; Li, Jin; Deng, Haiteng; Pei, Yong; Tian, Shi-Kai; Wu, Zhikun

    2017-10-02

    Although face-centered cubic (fcc), body-centered cubic (bcc), hexagonal close-packed (hcp), and other structured gold nanoclusters have been reported, it was unclear whether gold nanoclusters with mix-packed (fcc and non-fcc) kernels exist, and the correlation between kernel packing and the properties of gold nanoclusters is unknown. A Au 49 (2,4-DMBT) 27 nanocluster with a shell electron count of 22 has now been been synthesized and structurally resolved by single-crystal X-ray crystallography, which revealed that Au 49 (2,4-DMBT) 27 contains a unique Au 34 kernel consisting of one quasi-fcc-structured Au 21 and one non-fcc-structured Au 13 unit (where 2,4-DMBTH=2,4-dimethylbenzenethiol). Further experiments revealed that the kernel packing greatly influences the electrochemical gap (EG) and the fcc structure has a larger EG than the investigated non-fcc structure. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Charged hadron transverse momentum distributions in Au+Au collisions at √ SNN = 200 GeV

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.; van Nieuwenhuizen, Gerrit; PHOBOS Collaboration

    2003-04-01

    We present transverse momentum distributions of charged hadrons produced in Au+Au collisions at √ SNN = 200 GeV. The evolution of the spectra for transverse momenta p T from 0.25 to 5 GeV/C is studied as a function of collision centrality. We find a significant change of the spectral shape between proton-antiproton and peripheral Au+Au collisions. When comparing peripheral to central Au+Au collisions, we find that the yields at the highest p T exhibit approximate scaling with the number of participating nucleons, rather than scaling with the number of binary collisions.

  19. Synthesis, structure, and bonding in K12Au21Sn4. A polar intermetallic compound with dense Au20 and open AuSn4 layers.

    PubMed

    Li, Bin; Kim, Sung-Jin; Miller, Gordon J; Corbett, John D

    2009-12-07

    The new phase K(12)Au(21)Sn(4) has been synthesized by direct reaction of the elements at elevated temperatures. Single crystal X-ray diffraction established its orthorhombic structure, space group Pmmn (No. 59), a = 12.162(2); b = 18.058(4); c = 8.657(2) A, V = 1901.3(7) A(3), and Z = 2. The structure consists of infinite puckered sheets of vertex-sharing gold tetrahedra (Au(20)) that are tied together by thin layers of alternating four-bonded-Sn and -Au atoms (AuSn(4)). Remarkably, the dense but electron-poorer blocks of Au tetrahedra coexist with more open and saturated Au-Sn layers, which are fragments of a zinc blende type structure that maximize tetrahedral heteroatomic bonding outside of the network of gold tetrahedra. LMTO band structure calculations reveal metallic properties and a pseudogap at 256 valence electrons per formula unit, only three electrons fewer than in the title compound and at a point at which strong Au-Sn bonding is optimized. Additionally, the tight coordination of the Au framework atoms by K plays an important bonding role: each Au tetrahedra has 10 K neighbors and each K atom has 8-12 Au contacts. The appreciably different role of the p element Sn in this structure from that in the triel members in K(3)Au(5)In and Rb(2)Au(3)Tl appears to arise from its higher electron count which leads to better p-bonding (valence electron concentrations = 1.32 versus 1.22).

  20. Evidence from d+Au measurements for final-state suppression of high-p(T) hadrons in Au+Au collisions at RHIC.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Gutierrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2003-08-15

    We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high p(T)) in minimum bias and central d+Au collisions at sqrt[s(NN)]=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high p(T) previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions.

  1. Flow in Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Belt Tonjes, Marguerite; the PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2004-08-01

    The study of flow can provide information on the initial state dynamics and the degree of equilibration attained in heavy-ion collisions. This contribution presents results for both elliptic and directed flow as determined from data recorded by the PHOBOS experiment in Au+Au runs at RHIC at \\sqrt{sNN} = 19.6, 130 and 200 GeV. The PHOBOS detector provides a unique coverage in pseudorapidity for measuring flow at RHIC. The systematic dependence of flow on pseudorapidity, transverse momentum, centrality and energy is discussed.

  2. Flow in Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Belt Tonjes, Marguerite; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wyslouch, B.

    2004-08-01

    The study of flow can provide information on the initial state dynamics and the degree of equilibration attained in heavy-ion collisions. This contribution presents results for both elliptic and directed flow as determined from data recorded by the PHOBOS experiment in Au+Au runs at RHIC at \\sqrt{s_{{\\rm NN}}} = 19.6, 130 and 200 GeV. The PHOBOS detector provides a unique coverage in pseudorapidity for measuring flow at RHIC. The systematic dependence of flow on pseudorapidity, transverse momentum, centrality and energy is discussed.

  3. Nanoporous Au structures by dealloying Au/Ag thermal- or laser-dewetted bilayers on surfaces

    NASA Astrophysics Data System (ADS)

    Ruffino, F.; Torrisi, V.; Grillo, R.; Cacciato, G.; Zimbone, M.; Piccitto, G.; Grimaldi, M. G.

    2017-03-01

    Nanoporous Au attracts great technological interest and it is a promising candidate for optical and electrochemical sensors. In addition to nanoporous Au leafs and films, recently, interest was focused on nanoporous Au micro- and nano-structures on surfaces. In this work we report on the study of the characteristics of nanoporous Au structures produced on surfaces. We developed the following procedures to fabricate the nanoporous Au structures: we deposited thin Au/Ag bilayers on SiO2 or FTO (fluorine-doped tin oxide) substrates with thickness xAu and xAg of the Au and Ag layers; we induced the alloying and dewetting processes of the bilayers by furnace annealing processes of the bilayers deposited on SiO2 and by laser irradiations of the bilayers deposited on FTO; the alloying and dewetting processes result in the formation of AuxAgy alloy sub-micron particles being x and y tunable by xAu and xAg. These particles are dealloyed in HNO3 solution to remove the Ag atoms. We obtain, so, nanoporous sub-micron Au particles on the substrates. Analyzing the characteristics of these particles we find that: a) the size and shape of the particles depend on the nature of the dewetting process (solid-state dewetting on SiO2, molten-state dewetting on FTO); b) the porosity fraction of the particles depends on how the alloying process is reached: about 32% of porosity for the particles fabricated by the furnace annealing at 900 °C, about 45% of porosity for the particles fabricated by the laser irradiation at 0.5 J/cm2, in both cases independently on the Ag concentration in the alloy; c) After the dealloying process the mean volume of the Au particles shrinks of about 39%; d) After an annealing at 400 °C the nanoporous Au particles reprise their initial volume while the porosity fraction is reduced. Arguments to justify these behaviors are presented.

  4. Comment on “the ground-state structures of Au10-, Au8Ni and Au9Ni clusters”

    NASA Astrophysics Data System (ADS)

    Zheng, Ben-Xia; Die, Dong; Li, Qian-Qian; Dai, Ming-Liang; Li, Zhi-Qin; Yang, Ji-Xian

    2017-09-01

    The lowest energy structures of Aun+1- and AunNi (n = 2-9) clusters have been researched using the CALYPSO structure searching method in conjunction with the density functional theory. It is found that the most stable structures of Au10-, Au8Ni and Au9Ni clusters reported by Tang et al. [C. M. Tang, X. X. Chen and X. D. Yang, Int. J. Mod. Phys. B 28, 1450138 (2014)] are low-lying isomers. The correct ground states and vibrational spectra are given in this paper.

  5. Computer simulation of formation and decomposition of Au13 nanoparticles

    NASA Astrophysics Data System (ADS)

    Stishenko, P.; Svalova, A.

    2017-08-01

    To study the Ostwald ripening process of Au13 nanoparticles a two-scale model is constructed: analytical approximation of average nanoparticle energy as function of nanoparticle size and structural motive, and the Monte Carlo model of 1000 particles ensemble. Simulation results show different behavior of particles of different structural motives. The change of the distributions of atom coordination numbers during the Ostwald ripening process was observed. The nanoparticles of the equal size and shape with the face-centered cubic structure of the largest sizes appeared to be the most stable.

  6. Inverse Catalysts for CO Oxidation: Enhanced Oxide–Metal Interactions in MgO/Au(111), CeO 2/Au(111), and TiO 2/Au(111)

    DOE PAGES

    Palomino, Robert M.; Gutiérrez, Ramón A.; Liu, Zongyuan; ...

    2017-09-26

    Au(111) does not bind CO and O 2 well. The deposition of small nanoparticles of MgO, CeO 2, and TiO 2 on Au(111) produces excellent catalysts for CO oxidation at room temperature. In an inverse oxide/metal configuration there is a strong enhancement of the oxide–metal interactions, and the inverse catalysts are more active than conventional Au/MgO(001), Au/CeO 2(111), and Au/TiO 2(110) catalysts. An identical trend was seen after comparing the CO oxidation activity of TiO2/Au and Au/TiO 2 powder catalysts. In the model systems, the activity increased following the sequence: MgO/Au(111) < CeO 2/Au(111) < TiO 2/Au(111). Ambient pressure X-raymore » photoelectron spectroscopy (AP-XPS) was used to elucidate the role of the titania–gold interface in inverse TiO 2/Au(111) model catalysts during CO oxidation. Stable surface intermediates such as CO(ads), CO 3 2–(ads), and OH(ads) were identified under reaction conditions. CO 3 2–(ads) and OH(ads) behaved as spectators. The concentration of CO(ad) initially increased and then decreased with increasing TiO 2 coverage, demonstrating a clear role of the Ti–Au interface and the size of the TiO 2 nanostructures in the catalytic process. Overall, our results show an enhancement in the strength of the oxide–metal interactions when working with inverse oxide/metal configurations, a phenomenon that can be utilized for the design of efficient catalysts useful for green and sustainable chemistry.« less

  7. Inverse Catalysts for CO Oxidation: Enhanced Oxide–Metal Interactions in MgO/Au(111), CeO 2/Au(111), and TiO 2/Au(111)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Palomino, Robert M.; Gutiérrez, Ramón A.; Liu, Zongyuan

    Au(111) does not bind CO and O 2 well. The deposition of small nanoparticles of MgO, CeO 2, and TiO 2 on Au(111) produces excellent catalysts for CO oxidation at room temperature. In an inverse oxide/metal configuration there is a strong enhancement of the oxide–metal interactions, and the inverse catalysts are more active than conventional Au/MgO(001), Au/CeO 2(111), and Au/TiO 2(110) catalysts. An identical trend was seen after comparing the CO oxidation activity of TiO2/Au and Au/TiO 2 powder catalysts. In the model systems, the activity increased following the sequence: MgO/Au(111) < CeO 2/Au(111) < TiO 2/Au(111). Ambient pressure X-raymore » photoelectron spectroscopy (AP-XPS) was used to elucidate the role of the titania–gold interface in inverse TiO 2/Au(111) model catalysts during CO oxidation. Stable surface intermediates such as CO(ads), CO 3 2–(ads), and OH(ads) were identified under reaction conditions. CO 3 2–(ads) and OH(ads) behaved as spectators. The concentration of CO(ad) initially increased and then decreased with increasing TiO 2 coverage, demonstrating a clear role of the Ti–Au interface and the size of the TiO 2 nanostructures in the catalytic process. Overall, our results show an enhancement in the strength of the oxide–metal interactions when working with inverse oxide/metal configurations, a phenomenon that can be utilized for the design of efficient catalysts useful for green and sustainable chemistry.« less

  8. Influence of Au and TiO2 structures on hydrogen dissociation over TiO2/Au(100)

    NASA Astrophysics Data System (ADS)

    Nakamura, I.; Mantoku, H.; Furukawa, T.; Takahashi, A.; Fujitani, T.

    2012-11-01

    We performed H2-D2 exchange reactions over TiOx/Au(100) and compared the observed reaction kinetics with those reported for TiOx/Au(111) in order to clarify the influence of the Au and TiO2 structures on dissociation of H2 molecules. Low energy electron diffraction observations showed that the TiO2 produced on Au(100) was disordered, in contrast to the comparatively ordered TiO2 structure formed on Au(111). The activation energies and the turnover frequencies for HD formation over TiO2/Au(100) agreed well with those for TiO2/Au(111), clearly indicating that the hydrogen dissociation sites created over TiO2/Au(100) were the perimeter interface between stoichiometric TiO2 and Au, as was previously concluded for TiO2/Au(111). We concluded that the creation of active sites for hydrogen dissociation was independent of the Au and TiO2 structures consisting perimeter interface, and that local bonds that formed between Au and O atoms of stoichiometric TiO2 were essential for the creation of active sites.

  9. Eczematous Dermatitis Occurring on a Café-au-Lait Spot Long after Laser Radiation.

    PubMed

    Mihara, Motoyuki

    2013-05-01

    A 40-year-old woman presented with an itchy erythematosquamous change of a café-au-lait spot in her face. The onset of this change occurred just after her relocation. The café-au-lait spot had been irradiated by laser approximately 20 years ago. Clinically, there was a coin-sized erythema with a slight scale on the pigmented lesion in the left lateral orbital region. Histopathologically, the lesion demonstrated both spongiotic dermatitis and interface dermatitis together with lymphohistiocytic cell infiltration, in addition to moderate acanthosis and elongation of rete ridges with slight basal hyperpigmentation. From these clinical and histopathological findings, the lesion was diagnosed as eczematous dermatitis occurring on the café-au-lait spot after laser radiation. Another interesting histopathological finding was that some parts of a lobule of the sebaceous gland were occupied exclusively by degenerative atrophic sebocytes. From the viewpoint of pathogenesis, the eczematous dermatitis of this patient could have been an accompanying feature of a neurogenic inflammation occurring on the café-au-lait spot after laser radiation, and the atrophic change of a part of the sebaceous lobule might have been induced by a morphogenetic alteration of certain germinative cells of the sebaceous lobule due to laser radiation.

  10. Charged hadron transverse momentum distributions in Au+Au collisions at √sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Lee, J. W.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2004-01-01

    We present transverse momentum distributions of charged hadrons produced in Au+Au collisions at sNN=200 GeV. The spectra were measured for transverse momenta pT from 0.25 to 4.5 GeV/c in a pseudorapidity range of 0.2<η<1.4. The evolution of the spectra is studied as a function of collision centrality, from 65 to 344 participating nucleons. The results are compared to data from proton-antiproton collisions and Au+Au collisions at lower RHIC energies. We find a significant change of the spectral shape between proton-antiproton and semi-peripheral Au+Au collisions. Comparing semi-peripheral to central Au+Au collisions, we find that the yields at high pT exhibit approximate scaling with the number of participating nucleons, rather than scaling with the number of binary collisions.

  11. A comparative theoretical study of the catalytic activities of Au2(-) and AuAg(-) dimers for CO oxidation.

    PubMed

    Liu, Peng; Song, Ke; Zhang, Dongju; Liu, Chengbu

    2012-05-01

    The detailed mechanisms of catalytic CO oxidation over Au(2)(-) and AuAg(-) dimers, which represent the simplest models for monometal Au and bimetallic Au-Ag nanoparticles, have been studied by performing density functional theory calculations. It is found that both Au(2)(-) and AuAg(-) dimers catalyze the reaction according to the similar mono-center Eley-Rideal mechanism. The catalytic reaction is of the multi-channel and multi-step characteristic, which can proceed along four possible pathways via two or three elementary steps. In AuAg(-), the Au site is more active than the Ag site, and the calculated energy barrier values for the rate-determining step of the Au-site catalytic reaction are remarkably smaller than those for both the Ag-site catalytic reaction and the Au(2)(-) catalytic reaction. The better catalytic activity of bimetallic AuAg(-) dimer is attributed to the synergistic effect between Au and Ag atom. The present results provide valuable information for understanding the higher catalytic activity of Au-Ag nanoparticles and nanoalloys for low-temperature CO oxidation than either pure metallic catalyst.

  12. Chiral Magnetic Effect Search in p(d)+Au, Au+Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Zhao, Jie

    The chiral magnetic effect (CME) refers to charge separation along a strong magnetic field of single-handed quarks, caused by interactions with topological gluon fields from QCD vacuum fluctuations. A major background of CME measurements in heavy-ion collisions comes from resonance decays coupled with elliptical flow anisotropy. These proceedings present two new studies from STAR to shed further light on the background issue: (1) small system p+Au and d+Au collisions where the CME signal is not expected, and (2) pair invariant mass dependence where resonance peaks can be identified.

  13. STM imaging ortho- and para-fluorothiophenol self-assembled monolayers on Au(111).

    PubMed

    Jiang, Peng; Deng, Ke; Fichou, Denis; Xie, Si-Shen; Nion, Aymeric; Wang, Chen

    2009-05-05

    Self-assembled monolayers (SAMs) of para- and ortho-fluorothiophenol (p- and o-FTP) spontaneously formed on Au(111) substrate have been contrasted through investigation by a scanning tunneling microscope (STM) at room temperature. High-resolution STM imaging reveals that p-FTP adopts a 6 x radical3R30 degrees molecule arrangement containing six molecules. Two different kinds of p-FTP molecule dimer line structures have been formed on Au(111) by intermolecular pi-pi stacking along 112 substrate directions, besides a single p-FTP molecule line. In contrast, o-FTP molecules self-assemble into a much looser wave-like SAM, which can be described as a 5 x 3 radical3R30 degrees structure containing two molecules. Periodic density functional theory (DFT) calculations for the two systems suggest that these kinds of FTP molecules preferentially take the asymmetrical positions between 3-fold face-centered cubic (fcc) hollow and bridge sites on Au(111), tilting from the substrate surface. Theoretical simulation gives apparent average tilted angles of 58 degrees and 68 degrees for p-FTP and o-FTP with respect to the surface normal, respectively. This simulation shows that o-FTP is more inclined to lie down toward the Au(111) surface compared to p-FTP. The difference between p-FTP and o-FTP SAM structures can be qualitatively understood in terms of the variation of intermolecular dipole-dipole orientation. This suggests that, besides well-known Au-S and pi-pi interactions, electrostatic interactions including dipole-dipole, quadrupole-quadrupole, and dipole-quadrupole interactions might also play an important role in influencing the SAM structures formed by aromatic thiols with a permanent dipole moment.

  14. Enhanced middle-infrared light transmission through Au/SiO(x)N(y)/Au aperture arrays.

    PubMed

    Xiao, Gongli; Yao, Xiang; Ji, Xinming; Zhou, Jia; Bao, Zongming; Huang, Yiping

    2011-12-01

    The enhanced middle-infrared light transmission through Au/SiO(x)N(y)/Au aperture arrays by changing the refractive index and the thickness of a dielectric layer was studied experimentally. The results indicated that the transmission spectra was highly dependent on the refractive index and the thickness of SiO(x)N(y). We found that the transmission peaks redshifted regularly along with the refractive index from 1.6 to 1.8, owing to the role of surface plasmon polaritons (SPP) coupling in the Au/SiO(x)N(y)/Au cascaded metallic structure. Simultaneously, a higher transmission efficiency and narrower transmission peak was obtained in Au/SiO2.1N0.3/Au cascaded metallic structure with small refractive index (1.6) than in Au/SiO0.6N1/Au cascaded metallic structure with large refractive index (1.8). When the thickness of SiO(x)N(y) changes from 0.2 to 0.4 microm, the shape of transmission spectra exhibits a large change. It was found that a higher transmission efficiency and narrower transmission peak was obtained in Au/SiO(x)N(y)/Au cascaded metallic structure with a thin dielectric film (0.2 microm), with the increase of SiO(x)N(y) film's thickness, the transmission peak gradually widened and disappeared finally. This effect is useful in applications of biochemical sensing and tunable integrated plasmonic devices in the middle-infrared region.

  15. Largely enhanced photocatalytic activity of Au/XS2/Au (X = Re, Mo) antenna-reactor hybrids: charge and energy transfer.

    PubMed

    Chen, Kai; Ding, Si-Jing; Luo, Zhi-Jun; Pan, Gui-Ming; Wang, Jia-Hong; Liu, Jia; Zhou, Li; Wang, Qu-Quan

    2018-02-22

    An antenna-reactor hybrid coupling plasmonic antenna with catalytic nanoparticles is a new strategy to optimize photocatalytic activity. Herein, we have rationally proposed a Au/XS 2 /Au (X = Re, Mo) antenna reactor, which has a large Au core as the antenna and small satellite Au nanoparticles as the reactor separated by an ultrathin two-dimensional transition-metal dichalcogenide XS 2 shell (∼2.6 nm). Due to efficient charge transfer across the XS 2 shell as well as energy transfer via coupling of the Au antenna and Au reactor, the photocatalytic activity has been largely enhanced: Au/ReS 2 /Au exhibits a 3.59-fold enhancement, whereas Au/MoS 2 /Au exhibits a 2.66-fold enhancement as compared to that of the sum of the three individual components. The different enhancement in the Au/ReS 2 /Au and Au/MoS 2 /Au antenna-reactor hybrid is related to the competition and cooperation of charge and energy transfer. These results indicate the great potential of the Au/XS 2 /Au antenna-reactor hybrid for the development of highly efficient plasmonic photocatalysts.

  16. Au36(SPh)24 nanomolecules: X-ray crystal structure, optical spectroscopy, electrochemistry, and theoretical analysis.

    PubMed

    Nimmala, Praneeth Reddy; Knoppe, Stefan; Jupally, Vijay Reddy; Delcamp, Jared H; Aikens, Christine M; Dass, Amala

    2014-12-11

    The physicochemical properties of gold:thiolate nanomolecules depend on their crystal structure and the capping ligands. The effects of protecting ligands on the crystal structure of the nanomolecules are of high interest in this area of research. Here we report the crystal structure of an all aromatic thiophenolate-capped Au36(SPh)24 nanomolecule, which has a face-centered cubic (fcc) core similar to other nanomolecules such as Au36(SPh-tBu)24 and Au36(SC5H9)24 with the same number of gold atoms and ligands. The results support the idea that a stable core remains intact even when the capping ligand is varied. We also correct our earlier assignment of "Au36(SPh)23" which was determined based on MALDI mass spectrometry which is more prone to fragmentation than ESI mass spectrometry. We show that ESI mass spectrometry gives the correct assignment of Au36(SPh)24, supporting the X-ray crystal structure. The electronic structure of the title compound was computed at different levels of theory (PBE, LDA, and LB94) using the coordinates extracted from the single crystal X-ray diffraction data. The optical and electrochemical properties were determined from experimental data using UV-vis spectroscopy, cyclic voltammetry, and differential pulse voltammetry. Au36(SPh)24 shows a broad electrochemical gap near 2 V, a desirable optical gap of ∼1.75 eV for dye-sensitized solar cell applications, as well as appropriately positioned electrochemical potentials for many electrocatalytic reactions.

  17. On the nature of L1{sub 0} ordering in equiatomic AuNi and AuCu thin films grown on Au(001)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dynna, M.; Marty, A.; Gilles, B.

    1997-01-01

    The L1{sub 0} ordering of thin epitaxial films having a (001) surface normal subject to elastic constraints imposed by a similarly oriented substrate has been investigated both experimentally and theoretically. Thin AuNi films grown by MBE at room temperature on Au(001) by means of the alternating deposition of Au and Ni are found to possess a L1{sub 0} structure free of periodic antiphase boundaries when growth is controlled in such a way as to ensure that the quantity of Au or Ni deposited is almost exactly equal to one monolayer. If such control is not exercised during growth, a structuremore » having periodic antiphase boundaries is formed. This behavior stands in contrast to that of AuCu during room temperature MBE growth on Au(001), where a strongly ordered L2{sub 0} structure free of antiphase boundaries is formed even on the codeposition of Au and Cu. The effect of elastic constraints on the state of order in an alloy film which undergoes an L2{sub 0} order-disorder transition is examined as a function of temperature, lattice mismatch, and film thickness within the context of a model which allows for the introduction of dislocations in order to relieve misfit strain. Calculations are performed in detail for the case of AuCu, where particular attention is paid to the coupling between film thickness, the number of misfit dislocations present at equilibrium, and the state of order.« less

  18. Breakeven, cost benefit, cost effectiveness, and willingness to pay for web-based versus face-to-face education delivery for health professionals.

    PubMed

    Maloney, Stephen; Haas, Romi; Keating, Jenny L; Molloy, Elizabeth; Jolly, Brian; Sims, Jane; Morgan, Prue; Haines, Terry

    2012-04-02

    The introduction of Web-based education and open universities has seen an increase in access to professional development within the health professional education marketplace. Economic efficiencies of Web-based education and traditional face-to-face educational approaches have not been compared under randomized controlled trial conditions. To compare costs and effects of Web-based and face-to-face short courses in falls prevention education for health professionals. We designed two short courses to improve the clinical performance of health professionals in exercise prescription for falls prevention. One was developed for delivery in face-to-face mode and the other for online learning. Data were collected on learning outcomes including participation, satisfaction, knowledge acquisition, and change in practice, and combined with costs, savings, and benefits, to enable a break-even analysis from the perspective of the provider, cost-effectiveness analysis from the perspective of the health service, and cost-benefit analysis from the perspective of the participant. Face-to-face and Web-based delivery modalities produced comparable outcomes for participation, satisfaction, knowledge acquisition, and change in practice. Break-even analysis identified the Web-based educational approach to be robustly superior to face-to-face education, requiring a lower number of enrollments for the program to reach its break-even point. Cost-effectiveness analyses from the perspective of the health service and cost-benefit analysis from the perspective of the participant favored face-to-face education, although the outcomes were contingent on the sensitivity analysis applied (eg, the fee structure used). The Web-based educational approach was clearly more efficient from the perspective of the education provider. In the presence of relatively equivocal results for comparisons from other stakeholder perspectives, it is likely that providers would prefer to deliver education via a Web

  19. Breakeven, Cost Benefit, Cost Effectiveness, and Willingness to Pay for Web-Based Versus Face-to-Face Education Delivery for Health Professionals

    PubMed Central

    Haas, Romi; Keating, Jenny L; Molloy, Elizabeth; Jolly, Brian; Sims, Jane; Morgan, Prue; Haines, Terry

    2012-01-01

    Background The introduction of Web-based education and open universities has seen an increase in access to professional development within the health professional education marketplace. Economic efficiencies of Web-based education and traditional face-to-face educational approaches have not been compared under randomized controlled trial conditions. Objective To compare costs and effects of Web-based and face-to-face short courses in falls prevention education for health professionals. Methods We designed two short courses to improve the clinical performance of health professionals in exercise prescription for falls prevention. One was developed for delivery in face-to-face mode and the other for online learning. Data were collected on learning outcomes including participation, satisfaction, knowledge acquisition, and change in practice, and combined with costs, savings, and benefits, to enable a break-even analysis from the perspective of the provider, cost-effectiveness analysis from the perspective of the health service, and cost-benefit analysis from the perspective of the participant. Results Face-to-face and Web-based delivery modalities produced comparable outcomes for participation, satisfaction, knowledge acquisition, and change in practice. Break-even analysis identified the Web-based educational approach to be robustly superior to face-to-face education, requiring a lower number of enrollments for the program to reach its break-even point. Cost-effectiveness analyses from the perspective of the health service and cost-benefit analysis from the perspective of the participant favored face-to-face education, although the outcomes were contingent on the sensitivity analysis applied (eg, the fee structure used). Conclusions The Web-based educational approach was clearly more efficient from the perspective of the education provider. In the presence of relatively equivocal results for comparisons from other stakeholder perspectives, it is likely that providers

  20. Foreign investment in Asia in the 1990s: trends, problems and implications for manpower movements.

    PubMed

    Sekiguchi, S

    1992-01-01

    Direct foreign investment (DFI) is described as an international reallocation of managerial resources through which manpower moves across borders bidirectionally. This paper describes the diversity and rapidity of change in DFI for flows among North America, western Europe, Japan, ASEAN, Taiwan, China, Hong Kong, Korea, and Russia, and the implications for manpower movements. The US share of DFI in the Pacific Rim has declined while that of Japan and Western Europe has increased with the newly industrialized economies emerging regionally as net capital exporters. US and western European DFI will increasingly turn toward the Americas and Europe. Diminished US DFI will likely be compensated by Asian intraregional flows led by Japan, South Korea, Singapore, and Hong Kong. As for migration trends, bidirectinal flows of unskilled and professional labor may be stimulated by DFI, but only limited direct effects upon manpower movements should be expected.

  1. Role of Au(NPs) in the enhanced response of Au(NPs)-decorated MWCNT electrochemical biosensor

    PubMed Central

    Mehmood, Shahid; Ciancio, Regina; Carlino, Elvio; Bhatti, Arshad S

    2018-01-01

    Background The combination of Au-metallic-NPs and CNTs are a new class of hybrid nanomaterials for the development of electrochemical biosensor. Concentration of Au(nanoparticles [NPs]) in the electrochemical biosensor is crucial for the efficient charge transfer between the Au-NPs-MWCNTs modified electrode and electrolytic solution. Methods In this work, the charge transfer kinetics in the glassy carbon electrode (GCE) modified with Au(NPs)–multiwalled carbon nanotube (MWCNT) nanohybrid with varied concentrations of Au(NPs) in the range 40–100 nM was studied using electrochemical impedance spectroscopy (EIS). Field emission scanning electron microscopy and transmission electron microscopy confirmed the attachment of Au(NPs) on the surface of MWCNTs. Results The cyclic voltammetry and EIS results showed that the charge transfer mechanism was diffusion controlled and the rate of charge transfer was dependent on the concentration of Au(NPs) in the nanohybrid. The formation of spherical diffusion zone, which was dependent on the concentration of Au(NPs) in nanohybrids, was attributed to result in 3 times the increase in the charge transfer rate ks, 5 times increase in mass transfer, and 5% (9%) increase in Ipa (Ipc) observed in cyclic voltammetry in 80 nM Au(NP) nanohybrid-modified GCE from MWCNT-modified GCE. The work was extended to probe the effect of charge transfer rates at various concentrations of Au(NPs) in the nanohybrid-modified electrodes in the presence of Escherichia coli. The cyclic voltammetry results clearly showed the best results for 80 nM Au(NPs) in nanohybrid electrode. Conclusion The present study suggested that the formation of spherical diffusion zone in nanohybrid-modified electrodes is critical for the enhanced electrochemical biosensing applications. PMID:29713161

  2. Seed-mediated growth of Au nanorings with size control on Pd ultrathin nanosheets and their tunable surface plasmonic properties

    NASA Astrophysics Data System (ADS)

    Wang, Wenxing; Yan, Yucong; Zhou, Ning; Zhang, Hui; Li, Dongsheng; Yang, Deren

    2016-02-01

    Nanorings made of noble metals such as Au and Ag have attracted particular interest in plasmonic properties since they allow remarkable tunability of plasmon resonance wavelengths associated with their unique structural features. Unfortunately, most of the syntheses for Au nanorings involve complex procedures and/or require highly specialized and expensive facilities. Here, we report a seed-mediated approach for selective deposition of Au nanorings on the periphery of Pd seeds with the structure of an ultrathin nanosheet through the island growth mode. In combination with selective etching of Pd nanosheets, Au nanorings are eventually produced. We can control the outer diameter and wall thickness of the nanorings by simply varying the size of the Pd nanosheets and reaction time. By taking the advantage of this size controllability, the nanorings show tunable surface plasmonic properties in the near infrared (NIR) region arising from both the in-plane dipole and face resonance modes. Owing to their good surface plasmonic properties, the nanorings show substantially enhanced surface-enhanced Raman spectroscopy (SERS) performance for rhodamine 6G, and are therefore confirmed as good SERS substrates to detect trace amounts of molecules.Nanorings made of noble metals such as Au and Ag have attracted particular interest in plasmonic properties since they allow remarkable tunability of plasmon resonance wavelengths associated with their unique structural features. Unfortunately, most of the syntheses for Au nanorings involve complex procedures and/or require highly specialized and expensive facilities. Here, we report a seed-mediated approach for selective deposition of Au nanorings on the periphery of Pd seeds with the structure of an ultrathin nanosheet through the island growth mode. In combination with selective etching of Pd nanosheets, Au nanorings are eventually produced. We can control the outer diameter and wall thickness of the nanorings by simply varying the

  3. Nanocrystallization of Zr-Cu-Ni-Al-Au glassy alloys during severe plastic deformation

    NASA Astrophysics Data System (ADS)

    Yamada, Masahiro; Kamisato, Ryo; Yamasaki, Tohru; Adachi, Hiroki; Tsuchiya, Koichi; Yokoyama, Yoshihiko

    2014-08-01

    A study has been carried out into the formation of nanocrystalline grains during high-pressure torsion (HPT) deformation of Zr65Cu17Ni5Al10Au3 bulk alloys prepared using tilt casting. As a preliminary to this, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses were carried out on as-cast Zr65+xCu17-xNi5Al10Au3 (x=0~5 at.%) and Zr65Cu20Ni5Al10Au3 alloys, in order to determine the effect on the microstructure of the excess Zr content x and the presence of Au. From the XRD patterns, it was determined that all of the alloys had a metallic glassy nature. For Zr65Cu17Ni5Al10Au3, the DSC results indicated the presence of a wide supercooled liquid region between the glass transition temperature (Tg) of 644 K and the crystallization temperature of 763 K, where the stable body-centered tetragonal Zr2Cu phase was formed. In contrast, for the Zr65+xCu17-xNi5Al10Au3 alloys, precipitation of an icosahedral quasicrystalline phase (I-phase) was observed in the supercooled liquid region at about 715 K. HPT deformation of the Zr65Cu17Ni5Al10Au3 alloys was carried out under a high pressure of 5 GPa. Both as-cast specimens and those annealed at Tg-50 K for 90 min were used. Following a single HPT rotation (N=1), transmission electron microscopy identified the presence of face- centered cubic Zr2Ni precipitates in the as-cast alloy, with a size of about 50 nm. For the annealed alloy, a high density of I-phase precipitates with sizes of less than 10 nm was observed following HPT with N=10, indicating that the combination of severe plastic deformation and annealing is effective at producing extremely small grains.

  4. Investigation of the thermal annealing effect on electrical properties of Ni/Au, Ni/Mo/Au and Mo/Au Schottky barriers on AlGaN/GaN heterostructures

    NASA Astrophysics Data System (ADS)

    Sleptsov, E. V.; Chernykh, A. V.; Chernykh, S. V.; Dorofeev, A. A.; Gladysheva, N. B.; Kondakov, M. N.; Sleptsova, A. A.; Panichkin, A. V.; Konovalov, M. P.; Didenko, S. I.

    2017-03-01

    Investigation of the thermal annealing effect on Schottky barrier parameters and the leakage current of Ni/Au, Ni/Mo/Au and Mo/Au Schottky barriers on AlGaN/GaN heterostructures has been performed. Improvement of Schottky barrier parameters after annealing of the investigated metallization schemes was observed. Ni/Au and Mo/Au contacts drastically degrade after annealing at the temperatures higher than 400 °C, whereas the Ni/Mo/Au contact exhibits excellent parameters after 500 °C annealing (qϕb = 1.00 eV, n = 1.13 и Ileak = 5 μA).

  5. The effect of long-range order on the elastic properties of Cu3Au

    NASA Astrophysics Data System (ADS)

    Wang, Gui-Sheng; Krisztina Delczeg-Czirjak, Erna; Hu, Qing-Miao; Kokko, Kalevi; Johansson, Börje; Vitos, Levente

    2013-02-01

    Ab initio calculations, based on the exact muffin-tin orbitals method are used to determine the elastic properties of Cu-Au alloys with Au/Cu ratio 1/3. The compositional disorder is treated within the coherent potential approximation. The lattice parameters and single-crystal elastic constants are calculated for different partially ordered structures ranging from the fully ordered L12 to the random face centered cubic lattice. It is shown that the theoretical elastic constants follow a clear trend with the degree of chemical order: namely, C11 and C12 decrease, whereas C44 remains nearly constant with increasing disorder. The present results are in line with the experimental findings that the impact of the chemical ordering on the fundamental elastic parameters is close to the resolution of the available experimental and theoretical tools.

  6. Relativistic Effects and Gold Site Distributions: Synthesis, Structure, and Bonding in a Polar Intermetallic Na6Cd16Au7

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Samal, Saroj L.; Corbett, John D.

    Na{sub 6}Cd{sub 16}Au{sub 7} has been synthesized via typical high-temperature reactions, and its structure refined by single crystal X-ray diffraction as cubic, Fm{bar 3}m, a = 13.589(1) {angstrom}, Z = 4. The structure consists of Cd{sub 8} tetrahedral star (TS) building blocks that are face capped by six shared gold (Au2) vertexes and further diagonally bridged via Au1 to generate an orthogonal, three-dimensional framework [Cd{sub 8}(Au2){sub 6/2}(Au1){sub 4/8}], an ordered ternary derivative of Mn{sub 6}Th{sub 23}. Linear muffin-tin-orbital (LMTO)-atomic sphere approximation (ASA) electronic structure calculations indicate that Na{sub 6}Cd{sub 16}Au{sub 7} is metallic and that {approx}76% of the total crystalmore » orbital Hamilton populations (-ICOHP) originate from polar Cd-Au bonding with 18% more from fewer Cd-Cd contacts. Na{sub 6}Cd{sub 16}Au{sub 7} (45 valence electron count (vec)) is isotypic with the older electron-richer Mg{sub 6}Cu{sub 16}Si{sub 7} (56 vec) in which the atom types are switched and bonding characteristics among the network elements are altered considerably (Si for Au, Cu for Cd, Mg for Na). The earlier and more electronegative element Au now occupies the Si site, in accord with the larger relativistic bonding contributions from polar Cd-Au versus Cu-Si bonds with the neighboring Cd in the former Cu positions. Substantial electronic differences in partial densities-of-states (PDOS) and COHP data for all atoms emphasize these. Strong contributions of nearby Au 5d{sup 10} to bonding states without altering the formal vec are the likely origin of these effects.« less

  7. Slab melting and the origin of gold in Au and Au-Cu deposits: geochemical clues from recent adakites.

    NASA Astrophysics Data System (ADS)

    Polve, M.; Maury, R.; Joron, J. L.

    2003-04-01

    Understanding the genetic processes responsible for the common occurrence of Au and Au-Cu deposits in subduction environments is a fairly "hot" question nowadays, as it is clear that most subduction-related magmatic rocks are barren. Studies of space and time relationships between magmatic intrusions, hydrothermal episodes and Au deposits have shown that, very often, Au deposits are associated with adakitic intrusions (Thieblemont et al, 1997, Sajona and Maury, 1998). Adakites are here understood as being generated by melting of the subducting oceanic crust. This study aims to check wether or not magmas derived from melted oceanic crust do contain significantly more Au than regular calc-alkaline magmas by measuring directly Au concentrations in fresh (and barren) adakites and equivalent calc-alkaline andesites. There is a lack of reliable data on Au content in unaltered adakites and andesites, because Au analyses are generally done on hydrothermalized rocks in connection with Au deposits and also because old measurements may give overestimated Au contents, due to technical limitations. Therefore we compiled recent literature data on gold contents of fresh calc-alkaline rocks, and measured Au on a selection of 40 well studied and dated adakites from different localities (Philippines, Baja California). Analyses have been performed either by INAA or by ICP-MS after Au extraction with aqua regia, following the method described by Terashima (1988). Preliminary results show that, for equivalent Si02 contents, adakites are systematically enriched in Au compared to regular dacites, even if regional trends also exist. Moreover, Au seems to behave as an incompatible element in adakitic magmas, whereas in calc-alkaline dacites it is controlled by sulfide crystallization. Our data suggest that, not excluding any other processes related to the hydrothermal phase in the deposit generation, adakites may indeed represent the source of Au, a possible explanation for the adakite-Au

  8. Characteristics of Au Migration and Concentration Distributions in Au-Doped HgCdTe LPE Materials

    NASA Astrophysics Data System (ADS)

    Sun, Quanzhi; Yang, Jianrong; Wei, Yanfeng; Zhang, Juan; Sun, Ruiyun

    2015-08-01

    Annealing techniques and secondary ion mass spectrometry have been used to study the characteristics of Au migration and concentration distributions in HgCdTe materials grown by liquid phase epitaxy. Secondary ion mass spectrometry measurements showed that Au concentrations had obvious positive correlations with Hg-vacancy concentration and dislocation density of the materials. Au atoms migrate toward regions of high Hg-vacancy concentration or move away from these regions when the Hg-vacancy concentration decreases during annealing. The phenomenon can be explained by defect chemical equilibrium theory if Au atoms have a very large migration velocity compared with Hg vacancies. Au atoms will also migrate toward regions of high dislocation density, leading to a peak concentration in the inter-diffusion region of HgCdTe materials near the substrate. By use of an Hg and Te-rich annealing technique, different concentration distributions of both Au atoms and Hg vacancies in HgCdTe materials were obtained, indicating that Au-doped HgCdTe materials can be designed and prepared to satisfy the requirements of HgCdTe devices.

  9. Local structure and X-ray magnetic circular dichroism of Au in Au-Co nanoalloys

    NASA Astrophysics Data System (ADS)

    Maurizio, C.; Michieli, N.; Kalinic, B.; Mattarello, V.; Bello, V.; Wilhelm, F.; Ollefs, K.; Mattei, G.

    2018-03-01

    Coupling a plasmonic metal with a magnetic one in thin films and nanostructures is very interesting for the emerging field of magnetoplasmonics. In particular, coupling through alloying is a promising strategy to induce a magnetic moment on the plasmonic metal atoms, in a way that is intimately related to the local structure of the (metastable) alloy material. In this framework, Au:Co bimetallic films have been produced via magnetron co-sputtering deposition. X-ray absorption spectroscopy (XAS) at both Au- and Co-edges clearly indicates the formation of a full-metallic layer composed for the major part of a binary AuxCo1-x alloy, with x = 0.7-0.8. XAS and transmission electron microscopy analyses suggest the presence of a minor fraction of segregated metals. X-ray magnetic circular dichroism (XMCD) analysis at Au L2,3 edges detected a net magnetic moment of Au atoms (μ = 0.06 μB), significantly larger (≈3.5 times) that the one for Au-capped Co nanoclusters and comparable to the one for a Co-rich Au/Co multilayer, despite the 4 times larger concentration of Co with respect to the present case. This Au-Co magnetic coupling is favored by a high degree of mixing of the two metals in the alloy.

  10. Gold(I) Complexes with N-Donor Ligands. 2.(1) Reactions of Ammonium Salts with [Au(acac-kappaC(2))(PR(3))] To Give [Au(NH(3))L](+), [(AuL)(2)(&mgr;(2)-NH(2))](+), [(AuL)(4)(&mgr;(4)-N)](+), or [(AuL)(3)(&mgr;(3)-O)](+). A New and Facile Synthesis of [Au(NH(3))(2)](+) Salts. Crystal Structure of [{AuP(C(6)H(4)OMe-4)(3)}(3)(&mgr;(3)-O)]CF(3)SO(3).

    PubMed

    Vicente, José; Chicote, María-Teresa; Guerrero, Rita; Jones, Peter G.; Ramírez De Arellano, M. Carmen

    1997-09-24

    The complexes [Au(acac-kappaC(2))(PR(3))] (acac = acetylacetonate, R = Ph, C(6)H(4)OMe-4) react with (NH(4))ClO(4) to give amminegold(I), [Au(NH(3))(PR(3))]ClO(4), amidogold(I), [(AuPR(3))(2)(&mgr;(2)-NH(2))]ClO(4), or nitridogold(I), [(AuPR(3))(4)(&mgr;(4)-N)]ClO(4), complexes, depending on the reaction conditions. Similarly, [Au(acac-kappaC(2))(PPh(3))] reacts with (NH(3)R')OTf (OTf = CF(3)SO(3)) (1:1) or with [H(3)N(CH(2))(2)NH(2)]OTf (1:1) to give (amine)gold(I) complexes [Au(NH(2)R')(PPh(3))]OTf (R' = Me, C(6)H(4)NO(2)-4) or [(AuPPh(3))(2){&mgr;(2)-H(2)N(CH(2))(2)NH(2)}](OTf)(2), respectively. The ammonium salts (NH(2)R'(2))OTf (R' = Et, Ph) react with [Au(acac-kappaC(2))(PR(3))] (R = Ph, C(6)H(4)OMe-4) (1:2) to give, after hydrolysis, the oxonium salts [(AuPR(3))(3)(&mgr;(3)-O)]OTf (R = Ph, C(6)H(4)OMe-4). When NH(3) is bubbled through a solution of [AuCl(tht)] (tht = tetrahydrothiophene), the complex [Au(NH(3))(2)]Cl precipitates. Addition of [Au(NH(3))(2)]Cl to a solution of AgClO(4) or TlOTf leads to the isolation of [Au(NH(3))(2)]ClO(4) or [Au(NH(3))(2)]OTf, respectively. The crystal structure of [(AuPR(3))(3)(&mgr;(3)-O)]OTf.Me(2)CO (R = C(6)H(4)OMe-4) has been determined: triclinic, space group P&onemacr;, a = 14.884(3) Å, b = 15.828(3) Å, c = 16.061(3) Å, alpha = 83.39(3) degrees, beta = 86.28(3) degrees, gamma = 65.54(3) degrees, R1 (wR2) = 0.0370 (0.0788). The [(AuPR(3))(3)(&mgr;(3)-O)](+) cation shows an essentially trigonal pyramidal array of three gold atoms and one oxygen atom with O-Au-P bond angles of ca. 175 degrees and Au.Au contacts in the range 2.9585(7)-3.0505(14) Å. These cations are linked into centrosymmetric dimers through two short Au.Au [2.9585(7), 3.0919(9) Å] contacts. The gold atoms of the dimer form a six-membered ring with a chair conformation.

  11. Development of amperometric lysine biosensors based on Au nanoparticles/multiwalled carbon nanotubes/polymers modified Au electrodes.

    PubMed

    Chauhan, Nidhi; Singh, Anamika; Narang, Jagriti; Dahiya, Swati; Pundir, C S

    2012-11-07

    The construction of two amperometric l-lysine biosensors is described in this study. The construction comprises the covalent immobilization of lysine oxidase (LOx) onto nanocomposite composed of gold nanoparticles (AuNPs) and carboxylated multiwalled carbon nanotubes (c-MWCNT), decorated on (i) polyaniline (PANI) and (ii) poly 1,2 diaminobenzene (DAB), electrodeposited on Au electrodes. The biosensors were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and electrochemical impedance spectroscopy (EIS) studies. The optimum response (current) was observed within 2 s at pH 7.0 and 25 °C for LOx/AuNPs/c-MWCNT/PANI/Au, and 4 s at pH 7.0 and 30 °C for LOx/AuNPs/c-MWCNT/DAB/Au electrodes. There was a linear relationship between current and lysine concentration ranging from 5.0 to 600 μM for LOx/AuNPs/c-MWCNT/PANI/Au with a detection limit of 5.0 μM, and 20 to 600 μM for the LOx/AuNPs/c-MWCNT/DAB/Au electrode with a detection limit of 20 μM. The PANI modified electrode was in good agreement with the standard HPLC method, with a better correlation (r = 0.992) compared to the DAB modified electrode (r = 0.986). These observations revealed that the PANI modified Au electrode was better than the DAB modified electrode, and hence it was employed for the determination of lysine in milk, pharmaceutical tablets and sera. The PANI modified electrode showed a half life of 120 days, compared to that of 90 days for the DAB modified electrode, after their 100 uses, when stored at 4 °C.

  12. Synthesis of Au38(SCH2CH2Ph)24, Au36(SPh-tBu)24, and Au30(S-tBu)18 Nanomolecules from a Common Precursor Mixture.

    PubMed

    Rambukwella, Milan; Dass, Amala

    2017-10-17

    Phenylethanethiol protected nanomolecules such as Au 25 , Au 38 , and Au 144 are widely studied by a broad range of scientists in the community, owing primarily to the availability of simple synthetic protocols. However, synthetic methods are not available for other ligands, such as aromatic thiol and bulky ligands, impeding progress. Here we report the facile synthesis of three distinct nanomolecules, Au 38 (SCH 2 CH 2 Ph) 24 , Au 36 (SPh-tBu) 24 , and Au 30 (S-tBu) 18 , exclusively, starting from a common Au n (glutathione) m (where n and m are number of gold atoms and glutathiolate ligands) starting material upon reaction with HSCH 2 CH 2 Ph, HSPh-tBu, and HStBu, respectively. The systematic synthetic approach involves two steps: (i) synthesis of kinetically controlled Au n (glutathione) m crude nanocluster mixture with 1:4 gold to thiol molar ratio and (ii) thermochemical treatment of the purified nanocluster mixture with excess thiols to obtain thermodynamically stable nanomolecules. Thermochemical reactions with physicochemically different ligands formed highly monodispersed, exclusively three different core-size nanomolecules, suggesting a ligand induced core-size conversion and structural transformation. The purpose of this work is to make available a facile and simple synthetic method for the preparation of Au 38 (SCH 2 CH 2 Ph) 24 , Au 36 (SPh-tBu) 24 , and Au 30 (S-tBu) 18 , to nonspecialists and the broader scientific community. The central idea of simple synthetic method was demonstrated with other ligand systems such as cyclopentanethiol (HSC 5 H 9 ), cyclohexanethiol(HSC 6 H 11 ), para-methylbenzenethiol(pMBT), 1-pentanethiol(HSC 5 H 11 ), 1-hexanethiol(HSC 6 H 13 ), where Au 36 (SC 5 H 9 ) 24 , Au 36 (SC 6 H 11 ) 24 , Au 36 (pMBT) 24 , Au 38 (SC 5 H 11 ) 24 , and Au 38 (SC 6 H 13 ) 24 were obtained, respectively.

  13. Snapshots of crystal growth: Nanoclusters of organic conductors on Au(111) surfaces

    NASA Astrophysics Data System (ADS)

    Schott, J. H.; Ward, M. D.

    1994-06-01

    Mono- and multilayer crystalline nanoclusters of tetra-hiafulvalene-tetracyanoquinodimethane ((TTF) (TCNO)), a low-dimensional organic conductor in the bulk form, can be formed readily on Au(111) surfaces by vapor phase sublimation under ambient conditions. Scanning tunneling microscopy of monolayer (TTF)(TCNQ) films reveals a two-dimensional density of states (DOS) that is consistent with the arrangement of TTF and TCNO molecules in the ac face of bulk (TTF)(TCNO), in which the molecular planes are nearly parallel to the Au(111) substrate. In contrast, clusters with thicknesses corresponding to two or three molecular layers exhibit a transformation to a highly anisotropic DOS that can be attributed to interlayer molecular overlap in segregated TTF and TCNQ molecular chains along the c-axis, which can be described as 'molecular wires'. The orientation of the crystalline (TTF)(TCNO) clusters is preserved throughout the crystal growth sequence, leading to meso- and macroscopic (TTF)(TCNO) needles that are oriented perpendicular to the Au(111) substrate. These studies provide visualization of crystal growth from the initial stages of nucleation to macroscopic crystals, and a revealing example of the changes in electronic structure that occur during the evolution of molecular (TTF)(TCNQ) nuclei into a bulk crystalline phase.

  14. Photoluminescence from Au nanoparticles embedded in Au:oxide composite films

    NASA Astrophysics Data System (ADS)

    Liao, Hongbo; Wen, Weijia; Wong, George K.

    2006-12-01

    Au:oxide composite multilayer films with Au nanoparticles sandwiched by oxide layers (such as SiO2, ZnO, and TiO2) were prepared in a magnetron sputtering system. Their photoluminescence (PL) spectra were investigated by employing a micro-Raman system in which an Argon laser with a wavelength of 514 nm was used as the pumping light. Distinct PL peaks located at a wavelength range between 590 and 680 nm were observed in most of our samples, with Au particle size varying from several to hundreds of nanometers. It was found that the surface plasmon resonance (SPR) in these composites exerted a strong influence on the position of the PL peaks but had little effect on the PL intensity.

  15. Multiple Nonstoichiometric Phases with Discrete Composition Ranges in the CaAu5−CaAu4Bi−BiAu2 System. A Case Study of the Chemistry of Spinodal Decomposition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lin, Qisheng; Corbett, John D.

    2010-04-01

    Synthetic explorations in the CaAu{sub 5}-CaAu{sub 4}Bi-BiAu{sub 2} system at 400 C reveal five separate solid solution regions that show three distinct substitution patterns in the CaAu{sub 5} parent: (I) CaAu{sub 4}(Au{sub 1-m}Bi{sub m}) with 0 {le} m {le} 0.15(1), (II) 0.33(1) {le} m {le} 0.64(1), (III) 0.85(4) {le} m {le} 0.90(2); (IV) (Ca{sub 1-r}Au{sub r})Au{sub 4}(Bi{sub 1-s}Au{sub s}) with 0 {le} r {le} 0.39(1) and 0 {le} s {le} 0.12(2); (V) (Ca{sub 1-p-q}Au{sub p}Bi{sub q})Au{sub 4}Bi with 0.09(2) {le} p {le} 0.13(1) and 0.31(2) {le} q {le} 0.72(4). Single crystal X-ray studies establish that all of these phase regionsmore » have common cubic symmetry F{sub 4}3m and that their structures (MgCu{sub 4}Sn-type, an ordered derivative of MgCu{sub 2}) all feature three-dimensional networks of Au{sub 4} tetrahedra, in which the truncated tetrahedra are centered and capped by Ca/Au, Au/Bi, or Ca/Au/Bi mixtures to give 16-atom Friauf polyhedra. TB-LMTO-ASA and -COHP calculations also reveal that direct interactions between Ca-Au and Ca-Bi pairs of atoms are relatively weak and that the Bi-Au interactions in the unstable ideal CaAu{sub 4}Bi are antibonding in character at E{sub F} but that their bonding is optimized at {+-}1 e. Compositions between the five nonstoichiometric phases appear to undergo spinodal decompositions. The last phenomenon has been confirmed by HRTEM, STEM-HAADF, EPMA, and XRD studies of the nominal composition CaAu{sub 4.25}Bi{sub 0.75}. Its DTA analyses suggest that the phases resulting from spinodal decomposition have nearly the same melting point ({approx}807 C), as expected, and that they are interconvertible through peritectic reactions at {approx}717 C.« less

  16. Nanoporous Au: An experimental study on the porosity of dealloyed AuAg leafs

    NASA Astrophysics Data System (ADS)

    Grillo, R.; Torrisi, V.; Ruffino, F.

    2016-12-01

    We present a study on the fraction of porosity for dealloyed nanoporous Au leafs. Nanoporous Au is attracting great scientific interest due to its peculiar plasmonic properties and the high exposed surface (∼10 m2/g). As examples, it was used in prototypes of chemical and biological devices. However, the maximization of the devices sensitivity is subjected to the maximization of the exposed surface by the nanoporous Au, i. e. maximization of the porosity fraction. So, we report on the analyses of the porosity fraction in nanoporous Au leafs as a function of the fabrication process parameters. We dealloyed 60 μm-thick Au23Ag77 at.% leafs and we show that: a) for dealloying time till to 6 h, only a 450 nm-thick surface layer of the leafs assumes a nanoporous structure with a porosity fraction of 32%. For a dealloying time of 20 h the leafs result fragmented in small black pieces with a porosity fraction increased to 60%. b) After 600 °C-30 minutes annealing of the previous samples, the nanopores disappear due to the Au/residual Ag inter-diffusion. c) After a second dealloying process on the previously annealed samples, the surface nanoporous structure is, again, obtained with the porosity fraction increased to 50%.

  17. The effect of Au amount on size uniformity of self-assembled Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, S.-H.; Wang, D.-C.; Chen, G.-Y.; Chen, K.-Y.

    2008-03-01

    The self-assembled fabrication of nanostructure, a dreaming approach in the area of fabrication engineering, is the ultimate goal of this research. A finding was proved through previous research that the size of the self-assembled gold nanoparticles could be controlled with the mole ratio between AuCl4- and thiol. In this study, the moles of Au were fixed, only the moles of thiol were adjusted. Five different mole ratios of Au/S with their effect on size uniformity were investigated. The mole ratios were 1:1/16, 1:1/8, 1:1, 1:8, 1:16, respectively. The size distributions of the gold nanoparticles were analyzed by Mac-View analysis software. HR-TEM was used to derive images of self-assembled gold nanoparticles. The result reached was also the higher the mole ratio between AuCl4- and thiol the bigger the self-assembled gold nanoparticles. Under the condition of moles of Au fixed, the most homogeneous nanoparticles in size distribution derived with the mole ratio of 1:1/8 between AuCl4- and thiol. The obtained nanoparticles could be used, for example, in uniform surface nanofabrication, leading to the fabrication of ordered array of quantum dots.

  18. Colloidal Au and Au-alloy catalysts for direct borohydride fuel cells: Electrocatalysis and fuel cell performance

    NASA Astrophysics Data System (ADS)

    Atwan, Mohammed H.; Macdonald, Charles L. B.; Northwood, Derek O.; Gyenge, Elod L.

    Supported colloidal Au and Au-alloys (Au-Pt and Au-Pd, 1:1 atomic ratio) on Vulcan XC-72 (with 20 wt% metal load) were prepared by the Bönneman method. The electrocatalytic activity of the colloidal metals with respect to borohydride electro-oxidation for fuel cell applications was investigated by voltammetry on static and rotating electrodes, chronoamperometry, chronopotentiometry and fuel cell experiments. The fundamental electrochemical techniques showed that alloying Au, a metal that leads to the maximum eight-electron oxidation of BH 4 -, with Pd or Pt, well-known catalysts of dehydrogenation reactions, improved the electrode kinetics of BH 4 - oxidation. Fuel cell experiments corroborated the kinetic studies. Using 5 mg cm -2 colloidal metal load on the anode, it was found that Au-Pt was the most active catalyst giving a cell voltage of 0.47 V at 100 mA cm -2 and 333 K, while under identical conditions the cell voltage using colloidal Au was 0.17 V.

  19. Measurements of charmonium production in p+p, p+Au, and Au+Au collisions at s NN = 200  GeV with the STAR experiment

    DOE PAGES

    Todoroki, Takahito

    2017-09-25

    Here, we present the first results from the STAR MTD of mid-rapidity charmonium measurements via the di-muon decay channel in p+p, p+Au, and Au+Au collisions at √S NN = 200 GeV at RHIC. The inclusive J/Ψ production cross section in p+p collisions can be described by the Non-Relativistic QCD (NRQCD) formalism coupled with the color glass condensate e ective theory (CGC) at low transverse momentum (p T) and next-to-leading order NRQCD at high p T. The nuclear modification factor in p+Au collisions for inclusive J/Ψ is below unity at low p T and consistent with unity at high p T,more » which can be described by calculations including both nuclear PDF and nuclear absorption e ects. The double ratio of inclusive J/Ψ and Ψ(2S) production rates for 0 < p T < 10 GeV/c at mid-rapidity between p+p and p+Au collisions is measured to be 1.37 0.42 0.19. The nuclear modification factor in Au+Au collisions for inclusive J/Ψ shows significant J/Ψ suppression at high p T in central collisions and can be qualitatively described by transport models including dissociation and regeneration contributions.« less

  20. Measurements of charmonium production in p+p, p+Au, and Au+Au collisions at s NN = 200  GeV with the STAR experiment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Todoroki, Takahito

    Here, we present the first results from the STAR MTD of mid-rapidity charmonium measurements via the di-muon decay channel in p+p, p+Au, and Au+Au collisions at √S NN = 200 GeV at RHIC. The inclusive J/Ψ production cross section in p+p collisions can be described by the Non-Relativistic QCD (NRQCD) formalism coupled with the color glass condensate e ective theory (CGC) at low transverse momentum (p T) and next-to-leading order NRQCD at high p T. The nuclear modification factor in p+Au collisions for inclusive J/Ψ is below unity at low p T and consistent with unity at high p T,more » which can be described by calculations including both nuclear PDF and nuclear absorption e ects. The double ratio of inclusive J/Ψ and Ψ(2S) production rates for 0 < p T < 10 GeV/c at mid-rapidity between p+p and p+Au collisions is measured to be 1.37 0.42 0.19. The nuclear modification factor in Au+Au collisions for inclusive J/Ψ shows significant J/Ψ suppression at high p T in central collisions and can be qualitatively described by transport models including dissociation and regeneration contributions.« less

  1. High-temperature stability of Au/Pd/Cu and Au/Pd(P)/Cu surface finishes

    NASA Astrophysics Data System (ADS)

    Ho, C. E.; Hsieh, W. Z.; Lee, P. T.; Huang, Y. H.; Kuo, T. T.

    2018-03-01

    Thermal reliability of Au/Pd/Cu and Au/Pd(4-6 wt.% P)/Cu trilayers in the isothermal annealing at 180 °C were investigated by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and transmission electron microscopy (TEM). The pure Pd film possessed a nanocrystalline structure with numerous grain boundaries, thereby facilitating the interdiffusion between Au and Cu. Out-diffusion of Cu through Pd and Au grain boundaries yielded a significant amount of Cu oxides (CuO and Cu2O) over the Au surface and gave rise to void formation in the Cu film. By contrast, the Pd(P) film was amorphous and served as a good diffusion barrier against Cu diffusion. The results of this study indicated that amorphous Pd(P) possessed better oxidation resistance and thermal reliability than crystalline Pd.

  2. Self-organization of a self-assembled supramolecular rectangle, square, and three-dimensional cage on Au111 surfaces.

    PubMed

    Yuan, Qun-Hui; Wan, Li-Jun; Jude, Hershel; Stang, Peter J

    2005-11-23

    The structure and conformation of three self-assembled supramolecular species, a rectangle, a square, and a three-dimensional cage, on Au111 surfaces were investigated by scanning tunneling microscopy. These supramolecular assemblies adsorb on Au111 surfaces and self-organize to form highly ordered adlayers with distinct conformations that are consistent with their chemical structures. The faces of the supramolecular rectangle and square lie flat on the surface, preserving their rectangle and square conformations, respectively. The three-dimensional cage also forms well-ordered adlayers on the gold surface, forming regular molecular rows of assemblies. When the rectangle and cage were mixed together, the assemblies separated into individual domains, and no mixed adlayers were observed. These results provide direct evidence of the noncrystalline solid-state structures of these assemblies and information about how they self-organize on Au111 surfaces, which is of importance in the potential manufacturing of functional nanostructures and devices.

  3. Sexual risk behaviors among adolescents in Port-au-Prince, Haiti.

    PubMed

    Carver, Jasmine W; Dévieux, Jessy G; Gaston, Stéphanie C; Altice, Frederick L; Niccolai, Linda M

    2014-08-01

    Engagement in sexual activity among Haitian youth is increasing. The present cross-sectional study examined the independent correlates of sexual risk behaviors among 200 (108 male/92 female) 13-18 year-old adolescents in Port-au-Prince, Haiti using face-to-face interviews. The majority (60.0 %) had engaged in sexual intercourse. Multivariate modeling found males to be 3.52 times more likely to have had sex, 5.42 times more likely to report sexual debut before age 14, 9.75 times more likely to have >1 sexual partner, and 3.33 times more likely to not have used a condom during last sex. Adolescents living with parents, grandparents, aunts or uncles were less likely to report having unprotected sex compared with those without adult family members in the home (AOR range 0.26-0.51). The high prevalence of risky sex among males and the protective influence of stable family cohesiveness have important implications for HIV prevention efforts.

  4. Uncommon and Emissive {[Au2(C3H6NS2)2][Au(C3H6NS2)2]2(PF6)2} Mixed Au+ and Au3+ Pseudotetranuclear Crystalline Compound: Synthesis, Structural Characterization, and Optical Properties.

    PubMed

    Langaro, Ana P; Souza, Ana K R; Morassuti, Claudio Y; Lima, Sandro M; Casagrande, Gleison A; Deflon, Victor M; Nunes, Luiz A O; Da Cunha Andrade, Luis H

    2016-11-23

    An uncommon emissive pseudotetranuclear compound, {[Au 2 (C 3 H 6 NS 2 ) 2 ][Au(C 3 H 6 NS 2 ) 2 ] 2 (PF 6 ) 2 }, was synthesized and characterized in terms of its structure and optical properties. The synthesis produced a crystalline compound composed of four gold atoms with two different oxidation states (Au + and Au 3+ ) in the same crystalline structure. The title complex belonged to a triclinic crystalline system involving the centrosymmetric P1̅ space group. X-ray diffractometry and vibrational spectroscopy (infrared, Raman, and SERS) were used for structural characterization of the new crystal. The vibrational spectroscopy techniques supported the X-ray diffraction results and confirmed the presence of bonds including Au-Au and Au-S. Optical characterization performed using UV-vis spectroscopy showed that under ultraviolet excitation, the emissive crystalline complex presented characteristic broad luminescent bands centered at 420 and 670 nm.

  5. Compound formation and superconductivity in Au-Si: X-ray absorption measurements on ion-beam-mixed Au-Si films

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jeon, Y.; Jisrawi, N.; Liang, G.

    Multilayered Au-Si thin films have been deposited with the net compositions ''Au/sub 1-//sub x/Si/sub x/,'' x = 0.29, 0.5, and 0.8. After ion-beam mixing these films exhibited superconductivity in the 0.3--1.2 K range despite the nonsuperconducting character of both Au and Si. Near-edge x-ray absorption spectroscopy (XAS) measurements on the Au L/sub 3/ edge in these films indicate that metastable Au-Si compound formation occurs in these ion-mixed materials. Specifically, the XAS measurements indicate changes in Au 5d-orbital occupancy and changes in the local Au structural environment which are both consistent with local compound formation.

  6. Au plasmonics in a WS{sub 2}-Au-CuInS{sub 2} photocatalyst for significantly enhanced hydrogen generation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheng, Zhongzhou; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083; Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn

    2015-11-30

    Promoting the activities of photocatalysts is still the critical challenge in H{sub 2} generation area. Here, a Au plasmon enhanced photocatalyst of WS{sub 2}-Au-CuInS{sub 2} is developed by inserting Au nanoparticles between WS{sub 2} nanotubes and CuInS{sub 2} (CIS) nanoparticles. Due to the localized surface plasmonic resonance properties from Au nanoparticles, WS{sub 2}-Au-CIS shows the best performance as compared to Au-CIS, CIS, WS{sub 2}-CIS, CIS-Au, WS{sub 2}-Au, and WS{sub 2}-CIS-Au. The surface plasmonic resonance effects dramatically intensify the absorption of visible light and help to inject hot electrons into the semiconductors. Our findings open up an efficient method to optimizemore » the type-II structures for photocatalytic water splitting.« less

  7. [Correlation of the DNA fragmentation index and malformation rate of optimized sperm with embryonic development and early spontaneous abortion in IVF-ET].

    PubMed

    Jiang, Wei-Jie; Jin, Fan; Zhou, Li-Ming

    2016-06-01

    To investigate the effects of the DNA fragmentation index (DFI) and malformation rate (SMR) of optimized sperm on embryonic development and early spontaneous abortion in conventional in vitro fertilization and embryo transfer (IVF-ET). We selected 602 cycles of conventional IVF-ET for pure oviductal infertility that had achieved clinical pregnancies, including 505 cycles with ongoing pregnancy and 97 cycles with early spontaneous abortion. On the day of ovum retrieval, we examined the DNA integrity and morphology of the rest of the optimized sperm using the SCD and Diff-Quik methods, established the joint predictor (JP) by logistic equation, and assessed the value of DFI and SMR in predicting early spontaneous abortion using the ROC curve. The DFI, SMR, and high-quality embryo rate were (15.91±3.69)%, (82.85±10.24)%, and 46.53% (342/735) in the early spontaneous abortion group and (9.30±4.22)%, (77.32±9.19)%, and 56.43% (2263/4010) respectively in the ongoing pregnancy group, all with statistically significant differences between the two groups (P<0.05 ). Both the DFI and SMR were the risk factors of early spontaneous abortion (OR = 5.96 and 1.66; both P< 0.01). The areas under the ROC curve for DFI, SMR and JP were 0.893±0.019, 0.685±0.028, and 0.898±0.018, respectively. According to the Youden index, the optimal cut-off values of the DFI and SMR obtained for the prediction of early spontaneous abortion were approximately 15% and 80%. The DFI was correlated positively with SMR (r= 0.31, P<0.01) but the high-quality embryo rate negatively with both the DFI (r= -0.45, P<0.01) and SMR (r= -0.22, P<0.01). The DFI and SMR of optimized sperm are closely associated with embryonic development in IVF. The DFI has a certain value for predicting early spontaneous abortion with a threshold of approximately 15%, but SMR may have a lower predictive value.

  8. Identified particles in Au+Au collisions at S=200 GeV

    NASA Astrophysics Data System (ADS)

    Phobos Collaboration; Wosiek, Barbara; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2003-03-01

    The yields of identified particles have been measured at RHIC for Au+Au collisions at S=200 GeV using the PHOBOS spectrometer. The ratios of antiparticle to particle yields near mid-rapidity are presented. The first measurements of the invariant yields of charged pions, kaons and protons at very low transverse momenta are also shown.

  9. pH-Induced transformation of ligated Au25 to brighter Au23 nanoclusters.

    PubMed

    Waszkielewicz, Magdalena; Olesiak-Banska, Joanna; Comby-Zerbino, Clothilde; Bertorelle, Franck; Dagany, Xavier; Bansal, Ashu K; Sajjad, Muhammad T; Samuel, Ifor D W; Sanader, Zeljka; Rozycka, Miroslawa; Wojtas, Magdalena; Matczyszyn, Katarzyna; Bonacic-Koutecky, Vlasta; Antoine, Rodolphe; Ozyhar, Andrzej; Samoc, Marek

    2018-05-01

    Thiolate-protected gold nanoclusters have recently attracted considerable attention due to their size-dependent luminescence characterized by a long lifetime and large Stokes shift. However, the optimization of nanocluster properties such as the luminescence quantum yield is still a challenge. We report here the transformation of Au25Capt18 (Capt labels captopril) nanoclusters occurring at low pH and yielding a product with a much increased luminescence quantum yield which we have identified as Au23Capt17. We applied a simple method of treatment with HCl to accomplish this transformation and we characterized the absorption and emission of the newly created ligated nanoclusters as well as their morphology. Based on DFT calculations we show which Au nanocluster size transformations can lead to highly luminescent species such as Au23Capt17.

  10. Measurements of mass-dependent azimuthal anisotropy in central p + Au, d + Au, and He 3 + Au collisions at s N N = 200 GeV

    DOE PAGES

    Adare, A.; Aidala, C.; Ajitanand, N. N.; ...

    2018-06-11

    Here, we present measurements of the transverse-momentum dependence of elliptic flow v 2 for identified pions and (anti)protons at midrapidity (|η| < 0.35), in 0%–5% central p+Au and 3He+Au collisions at √ s NN = 200 GeV. When taken together with previously published measurements in d + Au collisions at √ s NN = 200 GeV, the results cover a broad range of small-collision-system multiplicities and intrinsic initial geometries. We observe a clear mass-dependent splitting of v 2(p T) in d + Au and 3He + Au collisions, just as in large nucleus-nucleus (A + A) collisions, and a smallermore » splitting in p + Au collisions. Both hydrodynamic and transport model calculations successfully describe the data at low p T (< 1.5GeV/c), but fail to describe various features at higher p T. In all systems, the v 2 values follow an approximate quark-number scaling as a function of the hadron transverse kinetic energy per constituent quark (KE T/n q), which was also seen previously in A + A collisions.« less

  11. Measurements of mass-dependent azimuthal anisotropy in central p + Au, d + Au, and He 3 + Au collisions at s N N = 200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adare, A.; Aidala, C.; Ajitanand, N. N.

    Here, we present measurements of the transverse-momentum dependence of elliptic flow v 2 for identified pions and (anti)protons at midrapidity (|η| < 0.35), in 0%–5% central p+Au and 3He+Au collisions at √ s NN = 200 GeV. When taken together with previously published measurements in d + Au collisions at √ s NN = 200 GeV, the results cover a broad range of small-collision-system multiplicities and intrinsic initial geometries. We observe a clear mass-dependent splitting of v 2(p T) in d + Au and 3He + Au collisions, just as in large nucleus-nucleus (A + A) collisions, and a smallermore » splitting in p + Au collisions. Both hydrodynamic and transport model calculations successfully describe the data at low p T (< 1.5GeV/c), but fail to describe various features at higher p T. In all systems, the v 2 values follow an approximate quark-number scaling as a function of the hadron transverse kinetic energy per constituent quark (KE T/n q), which was also seen previously in A + A collisions.« less

  12. Recent HBT results in Au+Au and p+p collisions from PHENIX

    NASA Astrophysics Data System (ADS)

    PHENIX Collaboration; Glenn, Andrew; PHENIX Collaboration

    2009-11-01

    We present Hanbury-Brown Twiss measurements from the PHENIX experiment at RHIC for final results for charged kaon pairs from s=200 GeV Au+Au collisions and preliminary results for charged pion pairs from s=200 GeVp+p collisions. We find that for kaon pairs from Au+Au, each traditional 3D Gaussian radius shows approximately the same linear increase as a function of Npart1/3. An imaging analysis reveals a significant non-Gaussian tail for r≳10 fm. The presence of a tail for kaon pairs demonstrates that similar non-Gaussian tails observed in earlier pion measurements cannot be fully explained by decays of long-lived resonances. The preliminary analysis of pions from s=200 GeV p+p minimum biased collisions show correlations which are well suited to traditional 3D HBT radii extraction via the Bowler-Sinyukov method, and we present R, R, and R as a function of mean transverse pair mass.

  13. {phi} meson production in Au + Au and p + p collisions at {radical}s{sub NN}=200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adams, J.; Adler, C.; Aggarwal, M.M.

    2004-06-01

    We report the STAR measurement of {psi} meson production in Au + Au and p + p collisions at {radical}s{sub NN} = 200 GeV. Using the event mixing technique, the {psi} spectra and yields are obtained at midrapidity for five centrality bins in Au+Au collisions and for non-singly-diffractive p+p collisions. It is found that the {psi} transverse momentum distributions from Au+Au collisions are better fitted with a single-exponential while the p+p spectrum is better described by a double-exponential distribution. The measured nuclear modification factors indicate that {psi} production in central Au+Au collisions is suppressed relative to peripheral collisions when scaledmore » by the number of binary collisions (). The systematics of versus centrality and the constant {psi}/K{sup -} ratio versus beam species, centrality, and collision energy rule out kaon coalescence as the dominant mechanism for {psi} production.« less

  14. Factors Influencing Dietary Fat Intake among Black Emerging Adults

    ERIC Educational Resources Information Center

    Horton, Shalonda E. B.; Timmerman, Gayle M.; Brown, Adama

    2018-01-01

    Objective: To determine what factors influenced dietary fat intake (DFI) among black emerging adults. Participants: Sample included 251 black emerging adults, ages 18-25 years, living in the US. Methods: This was a nonexperimental cross-sectional study based on self-report data. Results: The sample had high DFI. Factors related to DFI were gender…

  15. Measurements of mass-dependent azimuthal anisotropy in central p + Au, d + Au, and 3He + Au collisions at √{sN N}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Alfred, M.; Andrieux, V.; Apadula, N.; Asano, H.; Azmoun, B.; Babintsev, V.; Bagoly, A.; Bai, M.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bathe, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Blau, D. S.; Boer, M.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Bumazhnov, V.; Campbell, S.; Canoa Roman, V.; Cervantes, R.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Chujo, T.; Citron, Z.; Connors, M.; Cronin, N.; Csanád, M.; Csörgő, T.; Danley, T. W.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dion, A.; Diss, P. B.; Dixit, D.; Do, J. H.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fan, W.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukuda, Y.; Gal, C.; Gallus, P.; Garg, P.; Ge, H.; Giordano, F.; Glenn, A.; Goto, Y.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; He, X.; Hemmick, T. K.; Hill, J. C.; Hill, K.; Hodges, A.; Hollis, R. S.; Homma, K.; Hong, B.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Imai, K.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ivanishchev, D.; Jacak, B. V.; Jezghani, M.; Ji, Z.; Jia, J.; Jiang, X.; Johnson, B. M.; Jorjadze, V.; Jouan, D.; Jumper, D. S.; Kanda, S.; Kang, J. H.; Kapukchyan, D.; Karthas, S.; Kawall, D.; Kazantsev, A. V.; Key, J. A.; Khachatryan, V.; Khanzadeev, A.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, G. W.; Kim, M.; Kim, M. H.; Kimelman, B.; Kincses, D.; Kistenev, E.; Kitamura, R.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Komkov, B.; Kotov, D.; Kudo, S.; Kurgyis, B.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Lacey, R.; Lajoie, J. G.; Lebedev, A.; Lee, S.; Lee, S. H.; Leitch, M. J.; Leung, Y. H.; Lewis, N. A.; Li, X.; Li, X.; Lim, S. H.; Liu, M. X.; Loggins, V.-R.; Lökös, S.; Lovasz, K.; Lynch, D.; Majoros, T.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Masuda, H.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendoza, M.; Metzger, W. J.; Mignerey, A. C.; Mihalik, D. E.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Mitsuka, G.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, T.; Morrison, D. P.; Morrow, S. I.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagai, K.; Nagashima, K.; Nagashima, T.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakano, K.; Nattrass, C.; Netrakanti, P. K.; Niida, T.; Nishimura, S.; Nouicer, R.; Novák, T.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ottino, G. J.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, J. S.; Park, S.; Pate, S. F.; Patel, M.; Peng, J.-C.; Peng, W.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perezlara, C. E.; Perry, J.; Petti, R.; Phipps, M.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Pun, A.; Purschke, M. L.; Radzevich, P. V.; Rak, J.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richford, D.; Rinn, T.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Runchey, J.; Safonov, A. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, K.; Sato, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shioya, T.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Singh, B. K.; Singh, C. P.; Singh, V.; Skoby, M. J.; Slunečka, M.; Snowball, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Stepanov, M.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takeda, A.; Taketani, A.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarnai, G.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Towell, C. L.; Towell, R.; Towell, R. S.; Tserruya, I.; Ueda, Y.; Ujvari, B.; van Hecke, H. W.; Vazquez-Carson, S.; Velkovska, J.; Virius, M.; Vrba, V.; Vukman, N.; Wang, X. R.; Wang, Z.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; White, A. S.; Wong, C. P.; Woody, C. L.; Wysocki, M.; Xia, B.; Xu, C.; Xu, Q.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamamoto, H.; Yanovich, A.; Yin, P.; Yoo, J. H.; Yoon, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zharko, S.; Zhou, S.; Zou, L.; Phenix Collaboration

    2018-06-01

    We present measurements of the transverse-momentum dependence of elliptic flow v2 for identified pions and (anti)protons at midrapidity (|η |<0.35 ), in 0%-5% central p +Au and 3He+Au collisions at √{sNN}=200 GeV. When taken together with previously published measurements in d +Au collisions at √{sNN}=200 GeV, the results cover a broad range of small-collision-system multiplicities and intrinsic initial geometries. We observe a clear mass-dependent splitting of v2(pT) in d +Au and 3He+Au collisions, just as in large nucleus-nucleus (A +A ) collisions, and a smaller splitting in p +Au collisions. Both hydrodynamic and transport model calculations successfully describe the data at low pT (<1.5 GeV /c ), but fail to describe various features at higher pT. In all systems, the v2 values follow an approximate quark-number scaling as a function of the hadron transverse kinetic energy per constituent quark (K ET/nq ), which was also seen previously in A +A collisions.

  16. Electronic behaviour of Au-Pt alloys and the 4f binding energy shift anomaly in Au bimetallics- X-ray spectroscopy studies

    NASA Astrophysics Data System (ADS)

    Wang, Dongniu; Cui, Xiaoyu; Xiao, Qunfeng; Hu, Yongfeng; Wang, Zhiqiang; Yiu, Y. M.; Sham, T. K.

    2018-06-01

    The electronic structure and charge redistribution of 6s conduction charge and 5d charge in Au and Pt alloys, Au9Pt and AuPt9 have been investigated using a charge compensation model. It is found that, both the Au and Pt 4f binding energy (BE) exhibits a negative shift in the alloys relatively to the pure metal in apparent disagreement with electroneutrality considerations (Au is the most electronegative metallic element); more interestingly, the negative Au 4f BE shift in Au-Pt alloy is in contrast to previous observations for a large number of Au bimetallic systems with more electropositive hosts in which the more electropositive the host„ the more positive the Au 4f BE shift. This anomaly is counter intuitive to electronegativity considerations. This dilemma was resolved by the charge compensation model in which both electronegativity and charge neutrality can be satisfied and the overall charge flow δ, onto Au is small and positive and δ arises from charge flow of 6s conduction charge, Δnc onto Au site, which is partially compensated by the depletion of 6d charge Δnd at the Au site (δ = Δnc+ Δnd ˜0.1 >0). The much larger Coulomb interaction between 4f and 5d than that between 4f and 6s results in positive 4f BE shifts. The Au 4f BE shift in Au-Pt alloys together with 193Au Mössbauer data were used in the charge compensation model analysis which shows that the model is still valid in that the Au 4f shift in Au-Pt alloy arises from mainly conduction charge gain with little depletion of d charge at the Au site. The model also works for Pt. The Au and Pt 5d character in the alloys have been examined with valence band spectra which show both maintain their d characteristic in dilute alloys with Pt d piling up at the Fermi level, and the top of the Au valence band being pushed toward the Fermi level; this is confirmed with DFT densities of state calculations. When Pt is diluted in Au, it gains d charge as evident from the reduction in whiteline intensity

  17. The Durham Family Initiative: A Preventive System of Care

    ERIC Educational Resources Information Center

    Dodge, Kenneth A.; Berlin, Lisa J.; Epstein, Matthew; Spitz-Roth, Adele; O'Donnell, Karen; Kaufman, Martha; Amaya-Jackson, Lisa; Rosch, Joel; Christopoulos, Christina

    2004-01-01

    This article describes the Durham Family Initiative (DFI), an innovative effort to bring together child welfare and juvenile justice systems to reach DFI's goal of reducing the child abuse rate in Durham, North Carolina, by 50% within the next 10 years. DFI will follow principles of a preventive system of care (PSoC), which focuses on nurturing…

  18. Au99(SPh)42 nanomolecules: aromatic thiolate ligand induced conversion of Au144(SCH2CH2Ph)60.

    PubMed

    Nimmala, Praneeth Reddy; Dass, Amala

    2014-12-10

    A new aromatic thiolate protected gold nanomolecule Au99(SPh)42 has been synthesized by reacting the highly stable Au144(SCH2CH2Ph)60 with thiophenol, HSPh. The ubiquitous Au144(SR)60 is known for its high stability even at elevated temperature and in the presence of excess thiol. This report demonstrates for the first time the reactivity of the Au144(SCH2CH2Ph)60 with thiophenol to form a different 99-Au atom species. The resulting Au99(SPh)42 compound, however, is unreactive and highly stable in the presence of excess aromatic thiol. The molecular formula of the title compound is determined by high resolution electrospray mass spectrometry (ESI-MS) and confirmed by the preparation of the 99-atom nanomolecule using two ligands, namely, Au99(SPh)42 and Au99(SPh-OMe)42. This mass spectrometry study is an unprecedented advance in nanoparticle reaction monitoring, in studying the 144-atom to 99-atom size evolution at such high m/z (∼12k) and resolution. The optical and electrochemical properties of Au99(SPh)42 are reported. Other substituents on the phenyl group, HS-Ph-X, where X = -F, -CH3, -OCH3, also show the Au144 to Au99 core size conversion, suggesting minimal electronic effects for these substituents. Control experiments were conducted by reacting Au144(SCH2CH2Ph)60 with HS-(CH2)n-Ph (where n = 1 and 2), bulky ligands like adamantanethiol and cyclohexanethiol. It was observed that conversion of Au144 to Au99 occurs only when the phenyl group is directly attached to the thiol, suggesting that the formation of a 99-atom species is largely influenced by aromaticity of the ligand and less so on the bulkiness of the ligand.

  19. Face-to-face: Perceived personal relevance amplifies face processing

    PubMed Central

    Pittig, Andre; Schupp, Harald T.; Alpers, Georg W.

    2017-01-01

    Abstract The human face conveys emotional and social information, but it is not well understood how these two aspects influence face perception. In order to model a group situation, two faces displaying happy, neutral or angry expressions were presented. Importantly, faces were either facing the observer, or they were presented in profile view directed towards, or looking away from each other. In Experiment 1 (n = 64), face pairs were rated regarding perceived relevance, wish-to-interact, and displayed interactivity, as well as valence and arousal. All variables revealed main effects of facial expression (emotional > neutral), face orientation (facing observer > towards > away) and interactions showed that evaluation of emotional faces strongly varies with their orientation. Experiment 2 (n = 33) examined the temporal dynamics of perceptual-attentional processing of these face constellations with event-related potentials. Processing of emotional and neutral faces differed significantly in N170 amplitudes, early posterior negativity (EPN), and sustained positive potentials. Importantly, selective emotional face processing varied as a function of face orientation, indicating early emotion-specific (N170, EPN) and late threat-specific effects (LPP, sustained positivity). Taken together, perceived personal relevance to the observer—conveyed by facial expression and face direction—amplifies emotional face processing within triadic group situations. PMID:28158672

  20. Face-to-face: Perceived personal relevance amplifies face processing.

    PubMed

    Bublatzky, Florian; Pittig, Andre; Schupp, Harald T; Alpers, Georg W

    2017-05-01

    The human face conveys emotional and social information, but it is not well understood how these two aspects influence face perception. In order to model a group situation, two faces displaying happy, neutral or angry expressions were presented. Importantly, faces were either facing the observer, or they were presented in profile view directed towards, or looking away from each other. In Experiment 1 (n = 64), face pairs were rated regarding perceived relevance, wish-to-interact, and displayed interactivity, as well as valence and arousal. All variables revealed main effects of facial expression (emotional > neutral), face orientation (facing observer > towards > away) and interactions showed that evaluation of emotional faces strongly varies with their orientation. Experiment 2 (n = 33) examined the temporal dynamics of perceptual-attentional processing of these face constellations with event-related potentials. Processing of emotional and neutral faces differed significantly in N170 amplitudes, early posterior negativity (EPN), and sustained positive potentials. Importantly, selective emotional face processing varied as a function of face orientation, indicating early emotion-specific (N170, EPN) and late threat-specific effects (LPP, sustained positivity). Taken together, perceived personal relevance to the observer-conveyed by facial expression and face direction-amplifies emotional face processing within triadic group situations. © The Author (2017). Published by Oxford University Press.

  1. Results of aeroheating DFI and ET design-data test on a 0.0175-scale model 60-OTS conducted in the Von Karman Gas Dynamics Facility (VKF) 40" supersonic and the 50" hypersonic wind tunnels A and C

    NASA Technical Reports Server (NTRS)

    Marroquin, J.; Leef, C. R.

    1985-01-01

    The 0.0175-scale thin-skin thermocouple Model 60-OTS was tested in the von Karman Gas Facility 40-inch continuous flow supersonic tunnel A and the VKF Tunnel C. Testing was conducted at Mach numbers 2.25 to 4.0, and Reynolds numbers from 0.4 x 10 to the 6th power/ft to 6.6 x 10 to the 6th power/ft. Angle of attack range was from -5.0 to +5.0 degrees, and angle of sideslip range was from -6 to +6 degrees. The primary objective of this test was to provide a valid base for the external tank (ET) and solid rocket booster (SRB) heating prediction methodology for ascent flight by taking heating data at Development Flight Instrumentation (DFI) locations for flight conditions simulating STS-1 through -4. A second objective was to obtain additional aeroheating data to support potential reduction of the thermal protection system (TPS) on the ET. The third phase of the test was funded and conducted by NASA/MSFC for the purpose of establishing confidence in the data base from the lower temperature tunnel A.

  2. Uptake of Au(III) Ions by Aluminum Hydroxide and Their Spontaneous Reduction to Elemental Gold (Au(0)).

    PubMed

    Yokoyama; Matsukado; Uchida; Motomura; Watanabe; Izawa

    2001-01-01

    The behavior of AuCl(4)(-) ions during the formation of aluminum hydroxide at pH 6 was examined. With an increase in NaCl concentration, the content of gold taken up by aluminum hydroxide decreased, suggesting that chloro-hydroxy complexes of Au(III) ion were taken up due to the formation of Al-O-Au bonds. It was found unexpectedly that the Au(III) ions taken up were spontaneously reduced to elemental gold without addition of a specific reducing reagent and then colloidal gold particles were formed. The mechanisms for the uptake of Au(III) ions by aluminum hydroxide and for their spontaneous reduction are discussed. Copyright 2001 Academic Press.

  3. Facile Syntheses of Monodisperse Ultra-Small Au Clusters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bertino, Massimo F.; Sun, Zhong-Ming; Zhang, Rui

    2006-11-02

    During our effort to synthesize the tetrahedral Au20 cluster, we found a facile synthetic route to prepare monodisperse suspensions of ultra-small Au clusters AuN (N<12) using diphosphine ligands. In our monophasic and single-pot synthesis, a Au precursor ClAu(I)PPh3 and a bidentate phosphine ligand P(Ph)2(CH2)MP(Ph)2 (Ph = phenyl) are dissolved in an organic solvent. Au(I) is reduced slowly by a borane-tert-butylamine complex to form Au clusters coordinated by the diphosphine ligand. The Au clusters are characterized by both high resolution mass spectrometry and UV-Vis absorption spectroscopy. We found that the mean cluster size obtained depends on the chain length M ofmore » the ligand. In particular, a single monodispersed Au11 cluster is obtained with the P(Ph)2(CH2)3P(Ph)2 ligand, whereas P(Ph)2(CH2)MP(Ph)2 ligands with M = 5 and 6 yield Au10 and Au8 clusters. The simplicity of our synthetic method makes it suitable for large-scale production of nearly monodisperse ultrasmall Au clusters. It is suggested that diphosphines provide a set of flexible ligands to allow size-controlled synthesis of Au nanoparticles.« less

  4. STAR Au + Au Fixed Target Results

    NASA Astrophysics Data System (ADS)

    Meehan, Kathryn; STAR Collaboration

    2015-10-01

    The RHIC Beam Energy Scan (BES) program was proposed to look for the turn-off of signatures of the quark gluon plasma (QGP), search for a possible QCD critical point, and study the nature of the phase transition between hadronic and partonic matter. The results from the NA49 experiment at CERN have been used to claim that the onset of deconfinement occurs at a collision energy around a center-of-mass energy of 7 GeV, the low end of the BES range. Data from lower energies are needed to test if this onset occurs. The goal of the STAR Fixed-Target Program is to extend the collision energy range in BES II with the same detector to energies that are likely below the onset of deconfinement. Currently, STAR has inserted a gold target into the beam pipe and conducted test runs at center-of-mass energies 3.9 and 4.5 GeV. Tests have been done with both Au and Al beams. First physics results from a Coulomb analysis of Au + Au fixed-target collisions, which are found to be consistent with previous experiments, will be presented. These results demonstrate that STAR has good particle identification capabilities in this novel detector setup. Furthermore, the Coulomb potential, which is sensitive to the Z of the projectile and degree of baryonic stopping, will be compared with published results from the AGS. This material is based upon work supported by the National Science Foundation under Grant No. 1068833.

  5. A Tandem Microscopic-Electrochemical Examination of A Charge-Induced Surface Phase Sequence: Ordered Au(110) in Aqueous Iodide Electrolytes as Probed by Potentiodynamic Scanning Tunneling Microscopy

    DTIC Science & Technology

    1994-02-01

    and Rh(lll)9-12 by STM, and halides on Au(lll) by SXRS. 1 3 ’ 1 4 For several of these systems, especially anion adsorption on gold , the adsorbate...index faces of gold in aqueous solution by means of in- situ STM combined with conventional electrochemical methods. The value of the electrochemical...structure and conversion dynamics. A related description of the Au(lO0)-I- system, along with a comparison with the behavior of the other two low-index gold

  6. Thiol ligand-induced transformation of Au38(SC2H4Ph)24 to Au36(SPh-t-Bu)24.

    PubMed

    Zeng, Chenjie; Liu, Chunyan; Pei, Yong; Jin, Rongchao

    2013-07-23

    We report a disproportionation mechanism identified in the transformation of rod-like biicosahedral Au38(SCH2CH2Ph)24 to tetrahedral Au36(TBBT)24 nanoclusters. Time-dependent mass spectrometry and optical spectroscopy analyses unambiguously map out the detailed size-conversion pathway. The ligand exchange of Au38(SCH2CH2Ph)24 with bulkier 4-tert-butylbenzenethiol (TBBT) until a certain extent starts to trigger structural distortion of the initial biicosahedral Au38(SCH2CH2Ph)24 structure, leading to the release of two Au atoms and eventually the Au36(TBBT)24 nanocluster with a tetrahedral structure, in which process the number of ligands is interestingly preserved. The other product of the disproportionation process, i.e., Au40(TBBT)m+2(SCH2CH2Ph)24-m, was concurrently observed as an intermediate, which was the result of addition of two Au atoms and two TBBT ligands to Au38(TBBT)m(SCH2CH2Ph)24-m. The reaction kinetics on the Au38(SCH2CH2Ph)24 to Au36(TBBT)24 conversion process was also performed, and the activation energies of the structural distortion and disproportionation steps were estimated to be 76 and 94 kJ/mol, respectively. The optical absorption features of Au36(TBBT)24 are interpreted on the basis of density functional theory simulations.

  7. Autonomous Repair Mechanism of Creep Damage in Fe-Au and Fe-Au-B-N Alloys

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Kwakernaak, C.; Tichelaar, F. D.; Sloof, W. G.; Kuzmina, M.; Herbig, M.; Raabe, D.; Brück, E.; van der Zwaag, S.; van Dijk, N. H.

    2015-12-01

    The autonomous repair mechanism of creep cavitation during high-temperature deformation has been investigated in Fe-Au and Fe-Au-B-N alloys. Combined electron-microscopy techniques and atom probe tomography reveal how the improved creep properties result from Au precipitation within the creep cavities, preferentially formed on grain boundaries oriented perpendicular to the applied stress. The selective precipitation of Au atoms at the free creep cavity surface results in pore filling, and thereby, autonomous repair of the creep damage. The large difference in atomic size between the Au and Fe strongly hampers the nucleation of precipitates in the matrix. As a result, the matrix acts as a reservoir for the supersaturated solute until damage occurs. Grain boundaries and dislocations are found to act as fast transport routes for solute gold from the matrix to the creep cavities. The mechanism responsible for the self-healing can be characterized by a simple model for cavity growth and cavity filling.

  8. AuNP-PE interface/phase and its effects on the tensile behaviour of AuNP-PE composites

    NASA Astrophysics Data System (ADS)

    Wang, Yue; Wang, Ruijie; Wang, Chengyuan; Yu, Xiaozhu

    2018-06-01

    A comprehensive study was conducted for a gold nanoparticle (AuNP)-polyethylene (PE) composite. Molecular dynamic (MD) simulations were employed to construct the AuNP-PE systems, achieve their constitutive relations, and measure their tensile properties. Specifically, the AuNP-PE interface/phase was studied via the mass density profile, and its effect was evaluated by comparing the composite with a pure PE matrix. These research studies were followed by the study of the fracture mechanisms and the size and volume fraction effects of AuNPs. Efforts were also made to reveal the underlying physics of the MD simulations. In the present work, an AuNP-PE interface and a densified PE interphase were achieved due to the AuNP-PE van der Waals interaction. Such an interface/phase is found to enhance the Young's modulus and yield stress but decrease the fracture strength and strain.

  9. Flow and bose-einstein correlations in Au-Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Phobos Collaboration; Manly, Steven; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hofman, D.; Hollis, R. S.; Hołyinski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2003-03-01

    Argonne flow and Bose-Einstein correlations have been measured in Au-Au collisions at S=130 and 200 GeV using the PHOBOS detector at RHIC. The systematic dependencies of the flow signal on the transverse momentum, pseudorapidity, and centrality of the collision, as well as the beam energy are shown. In addition, results of a 3-dimensional analysis of two-pion correlations in the 200 GeV data are presented.

  10. Design and Preparation of Supported Au Catalyst with Enhanced Catalytic Activities by Rationally Positioning Au Nanoparticles on Anatase.

    PubMed

    Wang, Liang; Wang, Hong; Rice, Andrew E; Zhang, Wei; Li, Xiaokun; Chen, Mingshu; Meng, Xiangju; Lewis, James P; Xiao, Feng-Shou

    2015-06-18

    A synergistic effect between individual components is crucial for increasing the activity of metal/metal oxide catalysts. The greatest challenge is how to control the synergistic effect to obtain enhanced catalytic performance. Through density functional theory calculations of model Au/TiO2 catalysts, it is suggested that there is strong interaction between Au nanoparticles and Ti species at the edge/corner sites of anatase, which is favorable for the formation of stable oxygen vacancies. Motivated by this theoretical analysis, we have rationally prepared Au nanoparticles attached to edge/corner sites of anatase support (Au/TiO2-EC), confirmed by their HR-TEM images. As expected, this strong interaction is well characterized by Raman, UV-visible, and XPS techniques. Very interestingly, compared with conventional Au catalysts, Au/TiO2-EC exhibits superior catalytic activity in the oxidations using O2. Our approach to controlling Au nanoparticle positioning on anatase to obtain enhanced catalytic activity offers an efficient strategy for developing more novel supported metal catalysts.

  11. Probing Phase Evolutions of Au-Methyl-Propyl-Thiolate Self-Assembled Monolayers on Au(111) at the Molecular Level.

    PubMed

    Gao, Jianzhi; Lin, Haiping; Qin, Xuhui; Zhang, Xin; Ding, Haoxuan; Wang, Yitao; Rokni Fard, Mahroo; Kaya, Dogan; Zhu, Gangqiang; Li, Qing; Li, Youyong; Pan, Minghu; Guo, Quanmin

    2018-06-18

    A self-assembled monolayer (SAM) consisting of a mixture of CH 3 S-Au-SCH 3 , CH 3 S-Au-S(CH 2 ) 2 CH 3 , and CH 3 (CH 2 ) 2 S-Au-S(CH 2 ) 2 CH 3 was studied systematically using scanning tunneling microscopy and density functional calculations. We find that the SAM is subjected to frequent changes at the molecular level on the time scale of ∼minutes. The presence of CH 3 S or CH 3 S-Au as a dissociation product of CH 3 S-Au-SCH 3 plays a key role in the dynamical behavior of the mixed SAM. Slow phase separation takes place at room temperature over hours to days, leading to the formation of methyl-thiolate-rich and propyl-thiolate-rich phases. Our results provide new insights into the chemistry of the thiolate-Au interface, especially for ligand exchange reaction in the RS-Au-SR staple motif.

  12. Photoinduced Glycerol Oxidation over Plasmonic Au and AuM (M = Pt, Pd and Bi) Nanoparticle-Decorated TiO2 Photocatalysts

    PubMed Central

    Jedsukontorn, Trin; Saito, Nagahiro; Hunsom, Mali

    2018-01-01

    In this study, sol-immobilization was used to prepare gold nanoparticle (Au NP)-decorated titanium dioxide (TiO2) photocatalysts at different Au weight % (wt. %) loading (Aux/TiO2, where x is the Au wt. %) and Au–M NP-decorated TiO2 photocatalysts (Au3M3/TiO2), where M is bismuth (Bi), platinum (Pt) or palladium (Pd) at 3 wt. %. The Aux/TiO2 photocatalysts exhibited a stronger visible light absorption than the parent TiO2 due to the localized surface plasmon resonance effect. Increasing the Au content from 1 wt. % to 7 wt. % led to increased visible light absorption due to the increasing presence of defective structures that were capable of enhancing the photocatalytic activity of the as-prepared catalyst. The addition of Pt and Pd coupled with the Au3/TiO2 to form Au3M3/TiO2 improved the photocatalytic activity of the Au3/TiO2 photocatalyst by maximizing their light-absorption property. The Au3/TiO2, Au3Pt3/TiO2 and Au3Pd3/TiO2 photocatalysts promoted the formation of glyceraldehyde from glycerol as the principle product, while Au3Bi3/TiO2 facilitated glycolaldehyde formation as the major product. Among all the prepared photocatalysts, Au3Pd3/TiO2 exhibited the highest photocatalytic activity with a 98.75% glycerol conversion at 24 h of reaction time. PMID:29690645

  13. Sharp Transition from Nonmetallic Au246 to Metallic Au279 with Nascent Surface Plasmon Resonance.

    PubMed

    Higaki, Tatsuya; Zhou, Meng; Lambright, Kelly J; Kirschbaum, Kristin; Sfeir, Matthew Y; Jin, Rongchao

    2018-05-02

    The optical properties of metal nanoparticles have attracted wide interest. Recent progress in controlling nanoparticles with atomic precision (often called nanoclusters) provide new opportunities for investigating many fundamental questions, such as the transition from excitonic to plasmonic state, which is a central question in metal nanoparticle research because it provides insights into the origin of surface plasmon resonance (SPR) as well as the formation of metallic bond. However, this question still remains elusive because of the extreme difficulty in preparing atomically precise nanoparticles larger than 2 nm. Here we report the synthesis and optical properties of an atomically precise Au 279 (SR) 84 nanocluster. Femtosecond transient absorption spectroscopic analysis reveals that the Au 279 nanocluster shows a laser power dependence in its excited state lifetime, indicating metallic state of the particle, in contrast with the nonmetallic electronic structure of the Au 246 (SR) 80 nanocluster. Steady-state absorption spectra reveal that the nascent plasmon band of Au 279 at 506 nm shows no peak shift even down to 60 K, consistent with plasmon behavior. The sharp transition from nonmetallic Au 246 to metallic Au 279 is surprising and will stimulate future theoretical work on the transition and many other relevant issues.

  14. A fast response hydrogen sensor with Pd metallic grating onto a fiber's end-face

    NASA Astrophysics Data System (ADS)

    Yan, Haitao; Zhao, Xiaoyan; Zhang, Chao; Li, Qiu-Ze; Cao, Jingxiao; Han, Dao-Fu; Hao, Hui; Wang, Ming

    2016-01-01

    We demonstrated an integrated hydrogen sensor with Pd metallic grating fabricated on a fiber end-face. The grating consists of three thin metal layers in stacks, Au, WO3 and Pd. The WO3 is used as a waveguide layer between the Pd and Au layer. The Pd layer is etched by using a focused ion beam (FIB) method, forming a Pd metallic grating with period of 450 nm. The sensor is experimentally exposed to hydrogen gas environment. Changing the concentration from 0% to 4% which is the low explosive limit (LEL), the resonant wavelength measured from the reflection experienced 28.10 nm spectral changes in the visible range. The results demonstrated that the sensor is sensitive for hydrogen detection and it has fast response and low temperature effect.

  15. Au crystal growth on natural occurring Au-Ag aggregate elucidated by means of precession electron diffraction (PED)

    NASA Astrophysics Data System (ADS)

    Roqué Rosell, Josep; Portillo Serra, Joaquim; Aiglsperger, Thomas; Plana-Ruiz, Sergi; Trifonov, Trifon; Proenza, Joaquín A.

    2018-02-01

    In the present work, a lamella from an Au-Ag aggregate found in Ni-laterites has been examined using Transmission Electron Microscope to produce a series of Precision Electron Diffraction (PED) patterns. The analysis of the structural data obtained, coupled with Energy Dispersive X-ray microanalysis, made it possible to determine the orientation of twinned native gold growing on the Au-Ag aggregate. The native Au crystal domains are found to have grown at the outermost part of the aggregate whereas the inner core of the aggregate is an Au-Ag alloy (∼4 wt% Ag). The submicron structural study of the natural occurring Au aggregate points to the mobilization and precipitation of gold in laterites and provides insights on Au aggregates development at supergene conditions. This manuscript demonstrates the great potential of electron crystallographic analysis, and in particular, PED to study submicron structural features of micron sized mineral aggregates by using the example of a gold grain found in a Ni-laterite deposits.

  16. Fluorescent probe for turn-on sensing of L-cysteine by ensemble of AuNCs and polymer protected AuNPs.

    PubMed

    Xu, Xiaozhe; Qiao, Juan; Li, Nan; Qi, Li; Zhang, Shufeng

    2015-06-16

    A new fluorescent probe based on ensemble of gold nanoclusters (AuNCs) and polymer protected gold nanoparticles (AuNPs) for turn-on sensing of L-cysteine was designed and prepared. The AuNCs were protected by bovine serum albumin and had strong fluorescence. The polymer protected AuNPs were synthesized by a facile in situ strategy at room temperature and could quench the fluorescence of AuNCs due to the Förster resonance energy transfer. Interestingly, it has been observed that the quenched fluorescence of AuNCs was recovered by L-cysteine, which could induce the aggregation of polymer protected AuNPs by sulfur group. Then the prepared fluorescent probe was successfully used for determination of L-Cys in human urines, which would have an evolving aspect and promote the subsequent exploration. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Au-nanoparticles grafted on plasma treated PE

    NASA Astrophysics Data System (ADS)

    Švorčík, V.; Chaloupka, A.; Řezanka, P.; Slepička, P.; Kolská, Z.; Kasálková, N.; Hubáček, T.; Siegel, J.

    2010-03-01

    Polyethylene (PE) surface was treated with Ar plasma. Activated surface was grafted from methanol solution of 1,2-ethanedithiol. Then the sample was immersed into freshly prepared colloid solution of Au-nanoparticles. Finally Au layer was sputtered on the samples. Properties of the modified PE were studied using various methods: AFM, EPR, RBS and nanoindentation. It was shown that the plasma treatment results in degradation of polymer chain (AFM) and creation of free radicals by EPR. After grafting with dithiol, the concentration of free radicals declines. The presence of Au and S in the surface layer after the coating with Au-nanoparticles was proved by RBS. Plasma treatment changes PE surface morphology and increases surface roughness, too. Another significant change in surface morphology and roughness was observed after deposition of Au-nanoparticles. Nanoindentation measurements show that the grafting with Au-nanoparticles increases adhesion of subsequently sputtered Au layer.

  18. Au/ZnO nanoarchitectures with Au as both supporter and antenna of visible-light

    NASA Astrophysics Data System (ADS)

    Liu, Tianyu; Chen, Wei; Hua, Yuxiang; Liu, Xiaoheng

    2017-01-01

    In this paper, we fabricate Au/ZnO nanostructure with smaller ZnO nanoparticles loaded onto bigger gold nanoparticles via combining seed-mediated method and sol-gel method. The obtained Au/ZnO nanocomposites exhibit excellent properties in photocatalysis process like methyl orange (MO) degradation and oxidative conversion of methanol into formaldehyde under visible light irradiation. The enhanced properties were ascribed to the surface plasmon resonance (SPR) effect of Au nanoparticles, which could contribute to the separation of photo-excited electrons and holes and facilitate the process of absorbing visible light. This paper contributes to the emergence of multi-functional nanocomposites with possible applications in visible-light driven photocatalysts and makes the Au/ZnO photocatalyst an exceptional choice for practical applications such as environmental purification of organic pollutants in aqueous solution and the synthesis of fine chemicals and intermediates.

  19. Isomorphism and solid solutions among Ag- and Au-selenides

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Palyanova, Galina A.; Seryotkin, Yurii V.; Novosibirsk State University

    Au-Ag selenides were synthesized by heating stoichiometric mixtures of elementary substances of initial compositions Ag{sub 2−x}Au{sub x}Se with a step of x=0.25 (0≤x≤2) to 1050 °C and annealing at 500 °C. Scanning electron microscopy, optical microscopy, electron microprobe analysis and X-ray powder diffraction methods have been applied to study synthesized samples. Results of studies of synthesized products revealed the existence of three solid solutions with limited isomorphism Ag↔Au: naumannite Ag{sub 2}Se – Ag{sub 1.94}Au{sub 0.06}Se, fischesserite Ag{sub 3}AuSe{sub 2} - Ag{sub 3.2}Au{sub 0.8}Se{sub 2} and gold selenide AuSe - Au{sub 0.94}Ag{sub 0.06}Se. Solid solutions and AgAuSe phases were added tomore » the phase diagram of Ag-Au-Se system. Crystal-chemical interpretation of Ag-Au isomorphism in selenides was made on the basis of structural features of fischesserite, naumannite, and AuSe. - Highlights: • Au-Ag selenides were synthesized. • Limited Ag-Au isomorphism in the selenides is affected by structural features. • Some new phases were introduced to the phase diagram Ag-Au-Se.« less

  20. Energy Dependence of Particle Multiplicities in Central Au+Au Collisions

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Corbo, J.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hicks, D.; Hofman, D.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Rafelski, M.; Rbeiz, M.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2002-01-01

    We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at (sNN) = 200 GeV. For the 6% most central collisions, we obtain dNch/dη\\|\\|η\\|<1 = 650+/-35(syst). Compared to collisions at (sNN) = 130 GeV, the highest energy studied previously, an increase by a factor of 1.14+/-0.05 at 90% confidence level, is found. The energy dependence of the pseudorapidity density is discussed in comparison with data from proton-induced collisions and theoretical predictions.

  1. Electronic and geometric structures of Au30 clusters: a network of 2e-superatom Au cores protected by tridentate protecting motifs with u3-S

    NASA Astrophysics Data System (ADS)

    Tian, Zhimei; Cheng, Longjiu

    2015-12-01

    Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters.Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S

  2. Measurements of Strangeness Production on Au+Au collisions at 62 GeV

    NASA Astrophysics Data System (ADS)

    Guimaraes, K. S. F. F.; Munhoz, M. G.; Takahashi, J.; Moura, M. M.; Suaide, A. A. P.; Cosentino, M.

    2005-10-01

    The STAR (Solenoidal Tracker at RHIC) experiment is a large acceptance collider detector that measures primarily hadronic observables to search for signatures of the quark-gluon plasma phase transition and study strongly interacting matter at high energy density. Operational since June 2000, the new heavy ion collider RHIC has already provided Au+Au collisions at σNN = 62, 130 and 200 GeV as well as p+p and d+Au collisions at 200 GeV. The various collision energies and systems allow the systematic study of particle production in heavy ion collisions. In particular, the production of strange (anti-)particles is one of the major topics of STAR. This detector allows the measurement of a variety of particle species at mid-rapidity, like neutral kaons; Λ, Ξ, and Ω. hyperons; and their anti-particles that are reconstructed via their decay topology. The strangeness measurements should provide important information on various phenomenological aspects of ultra-relativistic heavy ion collisions. The goal of this work is to perform the measurement of neutral kaons on Au+Au collisions at 62 GeV. This measurement will bring important information about strangeness production in the energy range between the top RHIC energy and the top SPS energy, where important questions regarding particle production are still open. In this poster, preliminary results of the analysis will be presented, mainly the evaluation of the topological cuts necessary for the neutral kaon reconstruction and the corrections that are necessary to obtain the transverse momentum spectra.

  3. J/ψ suppression at forward rapidity in Au + Au collisions at sNN=39 and 62.4 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Ta'ani, H.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumgart, S.; Bazilevsky, A.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Bing, X.; Blau, D. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Csanád, M.; Csörgő, T.; Dairaku, S.; Datta, A.; Daugherity, M. S.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Garishvili, A.; Garishvili, I.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hanks, J.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Issah, M.; Ivanischev, D.; Jacak, B. V.; Javani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Kamin, J.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, H. J.; Kim, K.-B.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiss, Á.; Kistenev, E.; Klatsky, J.; Kleinjan, D.; Kline, P.; Komatsu, Y.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Král, A.; Krizek, F.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Lim, S. H.; Linden Levy, L. A.; Liu, M. X.; Love, B.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Masumoto, S.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyachi, Y.; Miyasaka, S.; Mohanty, A. K.; Moon, H. J.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Nagae, T.; Nagamiya, S.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Nederlof, A.; Nihashi, M.; Nouicer, R.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Okada, K.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, S. K.; Pate, S. F.; Patel, L.; Pei, H.; Peng, J.-C.; Pereira, H.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Qu, H.; Rak, J.; Ravinovich, I.; Read, K. F.; Reynolds, R.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Samsonov, V.; Sano, M.; Sarsour, M.; Sawada, S.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Themann, H.; Todoroki, T.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Yamaguchi, Y. L.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.

    2012-12-01

    We present measurements of the J/ψ invariant yields in sNN=39 and 62.4 GeV Au + Au collisions at forward rapidity (1.2<|y|<2.2). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au + Au collisions (RCP) and for various centrality selections in Au + Au relative to scaled p + p cross sections obtained from other measurements (RAA). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement.

  4. Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV.

    PubMed

    Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Corral, M M; Cramer, J G; Crawford, H J; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Magestro, D; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

    2003-02-28

    Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

  5. Observation of D 0 meson nuclear modifications in Au + Au collisions at s NN = 200 GeV

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2014-09-30

    We report the first measurement of charmed-hadron (D 0) production via the hadronic decay channel (D 0→K -+π +) in Au+Au collisions at √ sNN=200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N bin, from p+p to central Au+Au collisions. The D 0 meson yields in central Au+Aucollisions are strongly suppressed compared to those in p+p scaled by N bin, for transverse momenta p T>3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p Tmore » is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.« less

  6. Bi-functional Au/FeS (Au/Co3O4) composite for in situ SERS monitoring and degradation of organic pollutants

    NASA Astrophysics Data System (ADS)

    Ma, Shuzhen; Cai, Qian; Lu, Kailing; Liao, Fan; Shao, Mingwang

    2016-01-01

    The bi-functional Au/FeS (Au/Co3O4) composite was fabricated by in situ reducing Au nanoparticles onto the surface of FeS (Co3O4). The as-prepared FeS possessed a multi-structure composed of plenty of nanoplates, which were coated by Au nanoparticles with an average size of 47.5 nm. While the Co3O4 showed a thin hexagonal sheet containing Au nanoparticles on its surface with an average size of 79.0 nm. Both the as-prepared Au/FeS and Au/Co3O4 composites exhibited excellent SERS performance, capable of enhancing the Raman signals of R6G molecules with the enhancement factor up to 1.81 × 106 and 7.60 × 104, respectively. Moreover, Au/FeS (Au/Co3O4) composite also has been verified to have intrinsic peroxidase-like activity, which could decompose H2O2 into hydroxyl radicals and then degrade organic pollutants into small molecules. Therefore, SERS can be used to real-time and in situ monitoring the degradation process of R6G molecules, employing the Au/FeS (Au/Co3O4) composite both as SERS substrate and catalyst.

  7. Nucleation and growth of order in Cu(3)Au (111) films

    NASA Astrophysics Data System (ADS)

    Bonham, Scott William

    The present work epitaxial investigated two types of ordering phenomena using films of Cusb3Au, the order-disorder phase transition on the (111) crystal surface, and preferential selection of one of two possible stacking domains. Cusb3Au has long been a model system for studying order-disorder phase transition. Bulk material exhibits a discontinuous transition while the surfaces exhibit continuos transitions and the long-range order parameter S is proportional to (Tsb{c}-T)sp{beta}, where Tsb{c} is the critical temperature. The transition of the (111) surface is studied with qualitative reflection high-energy electron diffraction (RHEED), which is sensitive to only the first few atomic layers. This work significantly improves on an earlier study through both improved data collection and more comprehensive data analysis. The measured value of beta =0.50± 0.02 agrees with both the earlier measurements and with predictions of mean field theory. In addition, data on surface defects during the transition and on the kinetics of ordering are presented. During epitaxial growth of (111) face-centered cubic crystal films, such as disordered Cusb3Au, there are two possible ways that successive layers can be laid down, leading to two types of stacking domains. However, a small vicinal miscut (0.5sp° {-}1sp° ) of the crystal surface introduces step edges that change nucleation preferences of the domains, resulting in one being preferred over the other by ratios up to 700:1. Fifteen samples were measured and this preference has been found to depend systematically and strongly on the magnitude and direction of the sample miscut. A qualitative RHEED study confirms that a preference for one of the stacking senses is present after deposition of a few monlolayers of Cusb3Au. The observed behavior of the film can be explained by a model in which Cu and Au atoms minimize their number of Nb nearest neighbors when growing over the Nb step edges. This represents both a discovery of a

  8. Gold surfaces and nanoparticles are protected by Au(0)-thiyl species and are destroyed when Au(I)-thiolates form.

    PubMed

    Reimers, Jeffrey R; Ford, Michael J; Halder, Arnab; Ulstrup, Jens; Hush, Noel S

    2016-03-15

    The synthetic chemistry and spectroscopy of sulfur-protected gold surfaces and nanoparticles is analyzed, indicating that the electronic structure of the interface is Au(0)-thiyl, with Au(I)-thiolates identified as high-energy excited surface states. Density-functional theory indicates that it is the noble character of gold and nanoparticle surfaces that destabilizes Au(I)-thiolates. Bonding results from large van der Waals forces, influenced by covalent bonding induced through s-d hybridization and charge polarization effects that perturbatively mix in some Au(I)-thiolate character. A simple method for quantifying these contributions is presented, revealing that a driving force for nanoparticle growth is nobleization, minimizing Au(I)-thiolate involvement. Predictions that Brust-Schiffrin reactions involve thiolate anion intermediates are verified spectroscopically, establishing a key feature needed to understand nanoparticle growth. Mixing of preprepared Au(I) and thiolate reactants always produces Au(I)-thiolate thin films or compounds rather than monolayers. Smooth links to O, Se, Te, C, and N linker chemistry are established.

  9. Identified particle distributions in pp and Au+Au collisions at square root of (sNN)=200 GeV.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gutierrez, T D; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; de Toledo, A Szanto; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2004-03-19

    Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

  10. Surface plasmon aided high sensitive non-enzymatic glucose sensor using Au/NiAu multilayered nanowire arrays.

    PubMed

    Wang, Lanfang; Zhu, Weiqi; Lu, Wenbo; Qin, Xiufang; Xu, Xiaohong

    2018-07-15

    A novel plasmon aided non-enzymatic glucose sensor was first constructed based on the unique half-rough Au/NiAu multilayered nanowire arrays. These multilayered and half-rough nanowires provide high chemical activity and large surface area for glucose oxidation in an alkaline solution. Under visible light irradiation, the surface plasmons originated from Au part enhance the electron transfer in the vertically aligned nanowires, leading to high sensitivity and wide detection range. The resulting sensor exhibits a wide glucose detection concentration range, low detection limit, and high sensitivity for plasmon aided non-enzymatic glucose sensor. Moreover, the detection sensitivity is enhanced by almost 2 folds compared to that in the dark, which significantly enhanced the performance of Au/NiAu multilayered nanowire arrays sensor. An excellent selectivity and acceptable stability were also achieved. These results indicate that surface plasmon aided nanostructures are promising new platforms for the construction of non-enzymatic glucose sensors. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Collective flow measurements with HADES in Au+Au collisions at 1.23A GeV

    NASA Astrophysics Data System (ADS)

    Kardan, Behruz; Hades Collaboration

    2017-11-01

    HADES has a large acceptance combined with a good mass-resolution and therefore allows the study of dielectron and hadron production in heavy-ion collisions with unprecedented precision. With the statistics of seven billion Au-Au collisions at 1.23A GeV recorded in 2012, the investigation of higher-order flow harmonics is possible. At the BEVALAC and SIS18 directed and elliptic flow has been measured for pions, charged kaons, protons, neutrons and fragments, but higher-order harmonics have not yet been studied. They provide additional important information on the properties of the dense hadronic medium produced in heavy-ion collisions. We present here a high-statistics, multidifferential measurement of v1 and v2 for protons in Au+Au collisions at 1.23A GeV.

  12. Coincidence studies of He ionized by C{sup 6+}, Au{sup 24+}, and Au{sup 53+}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McGovern, M.; Walters, H. R. J.; Assafrao, D.

    2010-04-15

    A recently developed [Phys. Rev. A 79, 042707 (2009)] impact parameter coupled pseudostate approximation (CP) is applied to calculate triple differential cross sections for single ionization of He by C{sup 6+}, Au{sup 24+}, and Au{sup 53+} projectiles at impact energies of 100 and 2 MeV/amu for C{sup 6+} and 3.6 MeV/amu for Au{sup 24+} and Au{sup 53+}. For C{sup 6+}, satisfactory, but not perfect, agreement is found with experimental measurements in coplanar geometry, but there is substantial disagreement with data taken in a perpendicular plane geometry. The CP calculations firmly contradict a projectile-nucleus interaction model which has been used tomore » support the perpendicular plane measurements. For Au{sup 24+} and Au{sup 53+}, there is a complete lack of accord with the available experiments. However, for Au{sup 24+} the theoretical position appears to be quite firm with clear indications of convergence in the CP approximation and very good agreement between CP and the completely different three-distorted-waves eikonal-initial-state (3DW-EIS) approximation. The situation for Au{sup 53+} is different. At the momentum transfers at which the measurements were made, there are doubts about the convergence of the CP approximation and a factor of 2 difference between the CP and 3DW-EIS predictions. The discord between theory and experiment is even greater with the experiment giving cross sections a factor of 10 larger than the theory. A study of the convergence of the CP approximation shows that it improves rapidly with reducing momentum transfer. As a consequence, lower-order cross sections than the triple are quite well converged and present an opportunity for a more reliable test of the experiment.« less

  13. Isomorphism and solid solutions among Ag- and Au-selenides

    NASA Astrophysics Data System (ADS)

    Palyanova, Galina A.; Seryotkin, Yurii V.; Kokh, Konstantin A.; Bakakin, Vladimir V.

    2016-09-01

    Au-Ag selenides were synthesized by heating stoichiometric mixtures of elementary substances of initial compositions Ag2-xAuxSe with a step of х=0.25 (0≤х≤2) to 1050 °С and annealing at 500 °C. Scanning electron microscopy, optical microscopy, electron microprobe analysis and X-ray powder diffraction methods have been applied to study synthesized samples. Results of studies of synthesized products revealed the existence of three solid solutions with limited isomorphism Ag↔Au: naumannite Ag2Se - Ag1.94Au0.06Se, fischesserite Ag3AuSe2 - Ag3.2Au0.8Se2 and gold selenide AuSe - Au0.94Ag0.06Se. Solid solutions and AgAuSe phases were added to the phase diagram of Ag-Au-Se system. Crystal-chemical interpretation of Ag-Au isomorphism in selenides was made on the basis of structural features of fischesserite, naumannite, and AuSe.

  14. Sperm chromatin structure assay results after swim-up are related only to embryo quality but not to fertilization and pregnancy rates following IVF.

    PubMed

    Niu, Zhi-Hong; Shi, Hui-Juan; Zhang, Hui-Qin; Zhang, Ai-Jun; Sun, Yi-Juan; Feng, Yun

    2011-11-01

    The aim of this study was to investigate whether the sperm chromatin structure assay (SCSA) results after swim-up are related to fertilization rates, embryo quality and pregnancy rates following in vitro fertilization (IVF). A total of 223 couples undergoing IVF in our hospital from October 2008 to September 2009 were included in this study. Data on the IVF process and sperm chromatin structure assay results were collected. Fertilization rate, embryo quality and IVF success rates of different DNA fragmentation index (DFI) subgroups and high DNA stainability (HDS) subgroups were compared. There were no significant differences in fertilization rate, clinical pregnancy or delivery rates between the DFI and HDS subgroups. However, the group with abnormal DFI had a lower good embryo rate. So, we concluded that the SCSA variables, either DFI or HDS after swim-up preparation, were not valuable in predicting fertilization failure or pregnancy rate, but an abnormal DFI meant a lower good embryo rate following IVF.

  15. Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions.

    PubMed

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; DePhillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Gaudichet, L; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Gupta, N; Gutierrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; LaPointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Buren, G Van; van der Kolk, N; van Leeuwen, M; Molen, A M Vander; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2006-09-29

    We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

  16. Growth of germanium on Au(111): formation of germanene or intermixing of Au and Ge atoms?

    PubMed

    Cantero, Esteban D; Solis, Lara M; Tong, Yongfeng; Fuhr, Javier D; Martiarena, María Luz; Grizzi, Oscar; Sánchez, Esteban A

    2017-07-19

    We studied the growth of Ge layers on Au(111) under ultra-high vacuum conditions from the submonolayer regime up to a few layers with Scanning Tunneling Microscopy (STM), Direct Recoiling Spectroscopy (DRS) and Low Energy Electron Diffraction (LEED). Most STM images for the thicker layers are consistent with a commensurate 5 × 8 arrangement. The high surface sensitivity of TOF-DRS allows us to confirm the coexistence of Au and Ge atoms in the top layer for all stages of growth. An estimation of the Au to Ge ratio at the surface of the thick layer gives about 1 Au atom per 2 Ge ones. When the growth is carried out at sample temperatures higher than about 420 K, a fraction of the deposited Ge atoms migrate into the bulk of Au. This incorporation of Ge into the bulk reduces the growth rate of the Ge films, making it more difficult to obtain films thicker than a few layers. After sputtering the Ge/Au surface, the segregation of bulk Ge atoms to the surface occurs for temperatures ≥600 K. The surface obtained after segregation of Ge reaches a stable condition (saturation) with an n × n symmetry with n on the order of 14.

  17. Electron flow in large metallomacromolecules and electronic switch of nanoparticle stabilization: new click ferrocenyl dentromers that reduce Au(III) to Au nanoparticles.

    PubMed

    Astruc, Didier; Wang, Qi; Fu, Fangyu; Martinez-Villacorta, Angel M; Moya, Sergio; Salmon, Lionel; Ruiz, Jaime; Hunel, Julien; Vax, Amélie

    2018-06-04

    Click ferrocenyl-terminal dentromers, a family of arene-cored dendrimers with triple branching (9-Fc, 27-Fc, 81-Fc and 243-Fc) reduce Au(III) to ferricinium dentromer-stabilized Au nanoparticles (AuNPs). Cyclic voltammetry studies in CH2Cl2 show reversible CV waves with some adsorption for the 243-Fc dentromer and a number of redox groups found, 255 ± 25, using the Bard-Anson method, close to the theoretical number of 243. The dentromers reduce aqueous HAuCl4 to water-soluble ferricinium chloride dentromer-stabilized gold nanoparticles (AuNPs) with core sizes between 30 and 47 nm. These triazolylferricinium dentromer-stabilized AuNPs are reduced by cobaltocene to cobalticinium chloride and ferrocene dentromer-weakly stabilized AuNPs together with red shift of the AuNP plasmon. The weakness of the AuNP stabilization is characterized by dentromer extraction with CH2Cl2 along with irreversible AuNP agglomeration for the 9, 27 and 81-ferrocenyl dentromer, only the 243-ferrocenyl dentromer-AuNP withstanding this process. Altogether this demonstrates the electronic switch of the dentromer-mediated AuNP stabilization. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. External electric field effects on Schottky barrier at Gd3N@C80/Au interface

    NASA Astrophysics Data System (ADS)

    Onishi, Koichi; Nakashima, Fumihiro; Jin, Ge; Eto, Daichi; Hattori, Hayami; Miyoshi, Noriko; Kirimoto, Kenta; Sun, Yong

    2017-08-01

    The effects of the external electric field on the height of the Schottky barrier at the Gd3N@C80/Au interface were studied by measuring current-voltage characteristics at various temperatures from 200 K to 450 K. The Gd3N@C80 sample with the conduction/forbidden/valence energy band structure had a face-centered cubic crystal structure with the average grain size of several nanometers. The height of the Gd3N@C80/Au Schottky barrier was confirmed to be 400 meV at a low electric field at room temperature. Moreover, the height decreases with the increasing external electric field through a change of permittivity in the Gd3N@C80 sample due to a polarization of the [Gd3] 9 +-[N3 -+("separators="|C80 ) 6 -] dipoles in the Gd3N@C80 molecule. The field-dependence of the barrier height can be described using a power math function of the electric field strength. The results of the field-dependent barrier height indicate that the reduction in the Schottky barrier is due to an image force effect of the transport charge carrier at the Gd3N@C80/Au interface.

  19. Highly Stable [C60AuC60]+/- Dumbbells.

    PubMed

    Goulart, Marcelo; Kuhn, Martin; Martini, Paul; Chen, Lei; Hagelberg, Frank; Kaiser, Alexander; Scheier, Paul; Ellis, Andrew M

    2018-05-17

    Ionic complexes between gold and C 60 have been observed for the first time. Cations and anions of the type [Au(C 60 ) 2 ] +/- are shown to have particular stability. Calculations suggest that these ions adopt a C 60 -Au-C 60 sandwich-like (dumbbell) structure, which is reminiscent of [XAuX] +/- ions previously observed for much smaller ligands. The [Au(C 60 ) 2 ] +/- ions can be regarded as Au(I) complexes, regardless of whether the net charge is positive or negative, but in both cases, the charge transfer between the Au and C 60 is incomplete, most likely because of a covalent contribution to the Au-C 60 binding. The C 60 -Au-C 60 dumbbell structure represents a new architecture in fullerene chemistry that might be replicable in synthetic nanostructures.

  20. Heterojunction metal-oxide-metal Au-Fe{sub 3}O{sub 4}-Au single nanowire device for spintronics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reddy, K. M., E-mail: mrkongara@boisestate.edu; Punnoose, Alex; Hanna, Charles

    2015-05-07

    In this report, we present the synthesis of heterojunction magnetite nanowires in alumina template and describe magnetic and electrical properties from a single nanowire device for spintronics applications. Heterojunction Au-Fe-Au nanowire arrays were electrodeposited in porous aluminum oxide templates, and an extensive and controlled heat treatment process converted Fe segment to nanocrystalline cubic magnetite phase with well-defined Au-Fe{sub 3}O{sub 4} interfaces as confirmed by the transmission electron microscopy. Magnetic measurements revealed Verwey transition shoulder around 120 K and a room temperature coercive field of 90 Oe. Current–voltage (I-V) characteristics of a single Au-Fe{sub 3}O{sub 4}-Au nanowire have exhibited Ohmic behavior. Anomalous positivemore » magnetoresistance of about 0.5% is observed on a single nanowire, which is attributed to the high spin polarization in nanowire device with pure Fe{sub 3}O{sub 4} phase and nanocontact barrier. This work demonstrates the ability to preserve the pristine Fe{sub 3}O{sub 4} and well defined electrode contact metal (Au)–magnetite interface, which helps in attaining high spin polarized current.« less

  1. Disentangling flow and signals of Chiral Magnetic Effect in U+U, Au+Au and p+Au collisions

    NASA Astrophysics Data System (ADS)

    Tribedy, Prithwish; STAR Collaboration

    2017-11-01

    We present STAR measurements of the charge-dependent three-particle correlator γ a , b = 〈 cos ⁡ (ϕ1a + ϕ2b - 2ϕ3) 〉 /v2 { 2 } and elliptic flow v2 { 2 } in U+U, Au+Au and p+Au collisions at RHIC. The difference Δγ = γ (opposite-sign) - γ (same-sign) measures charge separation across the reaction plane, a predicted signal of the Chiral Magnetic Effect (CME). Although charge separation has been observed, it has been argued that the measured separation can also be explained by elliptic flow related backgrounds. In order to separate the two effects we perform measurements of the γ-correlator where background expectations differ from magnetic field driven effects. A differential measurement of γ with the relative pseudorapidity (Δη) between the first and second particles indicate that Δγ in peripheral A+A and p+A collisions are dominated by short-range correlations in Δη. However, a relatively wider component of the correlation in Δη tends to vanish the same way as projected magnetic field as predicted by MC-Glauber simulations.

  2. Initial Eccentricity in Deformed 197Au+197Au and 238U+238U Collisions at RHIC

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Filip, Peter; Lednicky, Richard; Masui, Hiroshi

    2010-07-07

    Initial eccentricity and eccentricity fluctuations of the interaction volume created in relativistic collisions of deformed {sup 197}Au and {sup 238}U nuclei are studied using optical and Monte-Carlo (MC) Glauber simulations. It is found that the non-sphericity noticeably influences the average eccentricity in central collisions and eccentricity fluctuations are enhanced due to deformation. Quantitative results are obtained for Au+Au and U+U collisions at energy {radical}s{sub NN} = 200 GeV.

  3. Sperm morphology and chromatin integrity in Swedish warmblood stallions and their relationship to pregnancy rates

    PubMed Central

    Morrell, Jane M; Johannisson, Anders; Dalin, Anne-Marie; Hammar, Linda; Sandebert, Thomas; Rodriguez-Martinez, Heriberto

    2008-01-01

    Background Artificial insemination is not as widely used in horses as in other domestic species, such as dairy cattle and pigs, partly because of the wide variation in sperm quality between stallion ejaculates and partly due to decreased fertility following the use of cooled transported spermatozoa. Furthermore, predictive tests for sperm fertilising ability are lacking. The objective of the present study was to assess sperm morphology and chromatin integrity in ejaculates obtained from 11 warmblood breeding stallions in Sweden, and to evaluate the relationship of these parameters to pregnancy rates to investigate the possibility of using these tests predictively. Methods Aliquots from fortyone ejaculates, obtained as part of the normal semen collection schedule at the Swedish National Stud, were used for morphological analysis by light microscopy, whereas thirtyseven were used for chromatin analysis (SCSA) by flow cytometry. The outcome of inseminations using these ejaculates was made available later in the same year. Results Ranges for the different parameters were as follows; normal morphology, 27–79.5%; DNA-fragmentation index (DFI), 4.8–19.0%; standard deviation of DNA fragmentation index (SD_DFI) 41.5–98.9, and mean of DNA fragmentation index (mean_DFI), 267.7–319.5. There was considerable variation among stallions, which was statistically significant for all these parameters except for mean_DFI (P < 0.001, P < 0.01, P < 0.001 and P < 0.2 respectively). There was a negative relationship between normal morphology and DFI (P < 0.05), between normal morphology and SD_DFI (P < 0.001), and between normal morphology and mean_DFI (P < 0.05). For specific defects, there was a direct relationship between the incidence of pear-shaped sperm heads and DFI (P < 0.05), and also nuclear pouches and DFI (P < 0.001), indicating that either morphological analysis or chromatin analysis was able to identify abnormalities in spermiogenesis that could compromise DNA

  4. Controlling Au Nanorod Dispersion in Thin Film Polymer Blends

    NASA Astrophysics Data System (ADS)

    Hore, Michael J. A.; Composto, Russell J.

    2012-02-01

    Dispersion of Au nanorods (Au NRs) in polymer thin films is studied using a combination of experimental and theoretical techniques. Here, we incorporate small volume fractions of polystyrene-functionalized Au NRs (φrod 0.05) into polystyrene (PS) thin films. By controlling the ratio of the brush length (N) to that of the matrix polymers (P), we can selectively obtain dispersed or aggregated Au NR structures in the PS-Au(N):PS(P) films. A dispersion map of these structures allows one to choose N and P to obtain either uniformly dispersed Au NRs or aggregates of closely packed, side-by-side aligned Au NRs. Furthermore, by blending poly(2,6-dimethyl-p-phenylene oxide) (PPO) into the PS films, we demonstrate that the Au nanorod morphology can be further tuned by reducing depletion-attraction forces and promoting miscibility of the Au NRs. These predictable structures ultimately give rise to tunable optical absorption in the films resulting from surface plasmon resonance coupling between the Au NRs. Finally, self-consistent field theoretic (SCFT) calculations for both the PS-Au(N):PS(P) and PS-Au(N):PS(P):PPO systems provide insight into the PS brush structure, and allow us to interpret morphology and optical property results in terms of wet and dry PS brush states.

  5. Identified hadron transverse momentum spectra in Au+Au collisions at sNN=62.4 GeV

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G. J. Van; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

    2007-02-01

    Transverse momentum spectra of pions, kaons, protons, and antiprotons from Au+Au collisions at sNN = 62.4 GeV have been measured by the PHOBOS experiment at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The identification of particles relies on three different methods: low momentum particles stopping in the first detector layers; the specific energy loss (dE/dx) in the silicon spectrometer, and time-of-flight measurement. These methods cover the transverse momentum ranges 0.03 0.2, 0.2 1.0, and 0.5 3.0 GeV/c, respectively. Baryons are found to have substantially harder transverse momentum spectra than mesons. The pT region in which the proton to pion ratio reaches unity in central Au+Au collisions at sNN = 62.4 GeV fits into a smooth trend as a function of collision energy. At low transverse mass, the spectra of various species exhibit a significant deviation from transverse mass scaling. The observed particle yields at very low pT are comparable to extrapolations from higher pT for kaons, protons and antiprotons. By comparing our results to Au+Au collisions at sNN = 200 GeV, we conclude that the net proton yield at midrapidity is proportional to the number of participant nucleons in the collision.

  6. Parameterization and study of elliptic flow coefficient for Au+Au and Cu+Cu collisions at RHIC energy 200 GeV/A

    NASA Astrophysics Data System (ADS)

    Kumar, Somani Ajit; Bright, Keswani; Sudhir, Bhardwaj; Ashish, Agnihotri

    2018-05-01

    Elliptic flow coefficient is important observable in search of Quark Gluon Plasma. The variation of elliptic flow coefficient with centrality were studied using events generated by AMPT (Default) for Au+Au and Cu+Cu collisions at center of mass energy of 200 GeV/A. We compared the simulated data results with RHIC-PHENIX experimental results and found close agreement between them. The study of the variation of the v2 for Au+Au and Cu+Cu was parameterized by fitting. We proposed a new formula to predict the expected value of v2 at particular centrality for Au+Au or Cu+Cu at 200 GeV/A.

  7. Atomic and electronic structures of Si(1 1 1)-(√3 x √3)R30°-Au and (6 × 6)-Au surfaces.

    PubMed

    Patterson, C H

    2015-12-02

    Si(1 1 1)-Au surfaces with around one monolayer of Au exhibit many ordered structures and structures containing disordered domain walls. Hybrid density functional theory (DFT) calculations presented here reveal the origin of these complex structures and tendency to form domain walls. The conjugate honeycomb chain trimer (CHCT) structure of the [Formula: see text]-Au phase contains Si atoms with non-bonding surface states which can bind Au atoms in pairs in interstices of the CHCT structure and make this surface metallic. Si adatoms adsorbed on the [Formula: see text]-Au surface induce a gapped surface through interaction with the non-bonding states. Adsorption of extra Au atoms in interstitial sites of the [Formula: see text]-Au surface is stabilized by interaction with the non-bonding orbitals and leads to higher coverage ordered structures including the [Formula: see text]-Au phase. Extra Au atoms bound in interstitial sites of the [Formula: see text]-Au surface result in top layer Si atoms with an SiAu4 butterfly wing configuration. The structure of a [Formula: see text]-Au phase, whose in-plane top atomic layer positions were previously determined by an electron holography technique (Grozea et al 1998 Surf. Sci. 418 32), is calculated using total energy minimization. The Patterson function for this structure is calculated and is in good agreement with data from an in-plane x-ray diffraction study (Dornisch et al 1991 Phys. Rev. B 44 11221). Filled and empty state scanning tunneling microscopy (STM) images are calculated for domain walls and the [Formula: see text]-Au structure. The [Formula: see text]-Au phase is 2D chiral and this is evident in computed and actual STM images. [Formula: see text]-Au and domain wall structures contain the SiAu4 motif with a butterfly wing shape. Chemical bonding within the Si-Au top layers of the [Formula: see text]-Au and [Formula: see text]-Au surfaces is analyzed and an explanation for the SiAu4 motif structure is given.

  8. CO oxidation on Alsbnd Au nano-composite systems

    NASA Astrophysics Data System (ADS)

    Rajesh, C.; Majumder, C.

    2018-03-01

    Using first principles method we report the CO oxidation behaviour of Alsbnd Au nano-composites in three different size ranges: Al6Au8, Al13Au42 and a periodic slab of Alsbnd Au(1 1 1) surface. The clusters prefer enclosed structures with alternating arrangement of Al and Au atoms, maximising Auδ-sbnd Alδ+ bonds. Charge distribution analysis suggests the charge transfer from Al to Au atoms, corroborated by the red shift in the density of states spectrum. Further, CO oxidation on these nano-composite systems was investigated through both Eley - Rideal and Langmuir Hinshelwood mechanism. While, these clusters interact with O2 non-dissociatively with an elongation of the Osbnd O bond, further interaction with CO led to formation of CO2 spontaneously. On contrary, the CO2 evolution by co-adsorption of O2 and CO molecules has a transition state barrier. On the basis of the results it is inferred that nano-composite material of Alsbnd Au shows significant promise toward effective oxidative catalysis.

  9. Comparison of the Effects of Magnetic Field on Low Noise MoAu and TiAu TES Bolometers

    NASA Astrophysics Data System (ADS)

    Hijmering, R. A.; Khosropanah, P.; Ridder, M.; Gao, J. R.; Hoevers, H.; Jackson, B.; Goldie, D.; Withington, S.; Kozorezov, A. G.

    2014-08-01

    Recently we have reported on the effects of magnetic field on our low noise (NEP = 4 W/Hz) [1] TiAu TES bolometers that are being developed at SRON for the SAFARI FIR Imaging Spectrometer on SPICA telescope that will be operated in three different wavelength bands: S-band for 30-60 , M-band for 60-110 and L-band for 110-210 . The arrays for the S- and M- band will be based on TiAu TES bolometer arrays, developed by SRON. The L-band array will be based on a MoAu TES bolometer developed by University of Cambridge. We have investigated the effect of the magnetic field on the current, responsivity, speed and critical current for both the TiAu and MoAu TES bolometers in our high accuracy magnetic field set-up. A clear difference in weak link behavior is observed between the two types of TES bolometers in both strength of the effect and period of the oscillations.

  10. Lateral spreading of Au contacts on InP

    NASA Technical Reports Server (NTRS)

    Fatemi, Navid S.; Weizer, Victor G.

    1990-01-01

    The contact spreading phenomenon observed when small area Au contacts on InP are annealed at temperatures above about 400 C was investigated. It was found that the rapid lateral expansion of the contact metallization which consumes large quantities of InP during growth is closely related to the third stage in the series of solid state reactions that occur between InP and Au, i.e., to the Au3In-to-Au9In4 transition. Detailed descriptions are presented of both the spreading process and the Au3In-to-Au9In4 transition along with arguments that the two processes are manifestations of the same basic phenomenon.

  11. Scaling Properties of Proton and Antiproton Production in (sNN)=200 GeV Au+Au Collisions

    NASA Astrophysics Data System (ADS)

    Adler, S. S.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Alexander, J.; Amirikas, R.; Aphecetche, L.; Aronson, S. H.; Averbeck, R.; Awes, T. C.; Azmoun, R.; Babintsev, V.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bazilevsky, A.; Belikov, S.; Berdnikov, Y.; Bhagavatula, S.; Boissevain, J. G.; Borel, H.; Borenstein, S.; Brooks, M. L.; Brown, D. S.; Bruner, N.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camard, X.; Chai, J.-S.; Chand, P.; Chang, W. C.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J.; Choudhury, R. K.; Chujo, T.; Cianciolo, V.; Cobigo, Y.; Cole, B. A.; Constantin, P.; D'Enterria, D. G.; David, G.; Delagrange, H.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Drapier, O.; Drees, A.; Du Rietz, R.; Durum, A.; Dutta, D.; Efremenko, Y. V.; El Chenawi, K.; Enokizono, A.; En'yo, H.; Esumi, S.; Ewell, L.; Fields, D. E.; Fleuret, F.; Fokin, S. L.; Fox, B. D.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fung, S.-Y.; Garpman, S.; Ghosh, T. K.; Glenn, A.; Gogiberidze, G.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, G.; Guryn, W.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hamagaki, H.; Hansen, A. G.; Hartouni, E. P.; Harvey, M.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Heuser, J. M.; Hibino, M.; Hill, J. C.; Holzmann, W.; Homma, K.; Hong, B.; Hoover, A.; Ichihara, T.; Ikonnikov, V. V.; Imai, K.; Isenhower, L. D.; Ishihara, M.; Issah, M.; Isupov, A.; Jacak, B. V.; Jang, W. Y.; Jeong, Y.; Jia, J.; Jinnouchi, O.; Johnson, B. M.; Johnson, S. C.; Joo, K. S.; Jouan, D.; Kametani, S.; Kamihara, N.; Kang, J. H.; Kapoor, S. S.; Katou, K.; Kelly, S.; Khachaturov, B.; Khanzadeev, A.; Kikuchi, J.; Kim, D. H.; Kim, D. J.; Kim, D. W.; Kim, E.; Kim, G.-B.; Kim, H. J.; Kistenev, E.; Kiyomichi, A.; Kiyoyama, K.; Klein-Boesing, C.; Kobayashi, H.; Kochenda, L.; Kochetkov, V.; Koehler, D.; Kohama, T.; Kopytine, M.; Kotchetkov, D.; Kozlov, A.; Kroon, P. J.; Kuberg, C. H.; Kurita, K.; Kuroki, Y.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Ladygin, V.; Lajoie, J. G.; Lebedev, A.; Leckey, S.; Lee, D. M.; Lee, S.; Leitch, M. J.; Li, X. H.; Lim, H.; Litvinenko, A.; Liu, M. X.; Liu, Y.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Manko, V. I.; Mao, Y.; Martinez, G.; Marx, M. D.; Masui, H.; Matathias, F.; Matsumoto, T.; McGaughey, P. L.; Melnikov, E.; Messer, F.; Miake, Y.; Milan, J.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mischke, R. E.; Mishra, G. C.; Mitchell, J. T.; Mohanty, A. K.; Morrison, D. P.; Moss, J. M.; Mühlbacher, F.; Mukhopadhyay, D.; Muniruzzaman, M.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Nakamura, T.; Nandi, B. K.; Nara, M.; Newby, J.; Nilsson, P.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, K.; Ono, M.; Onuchin, V.; Oskarsson, A.; Otterlund, I.; Oyama, K.; Ozawa, K.; Pal, D.; Palounek, A. P.; Pantuev, V. S.; Papavassiliou, V.; Park, J.; Parmar, A.; Pate, S. F.; Peitzmann, T.; Peng, J.-C.; Peresedov, V.; Pinkenburg, C.; Pisani, R. P.; Plasil, F.; Purschke, M. L.; Purwar, A.; Rak, J.; Ravinovich, I.; Read, K. F.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosnet, P.; Ryu, S. S.; Sadler, M. E.; Saito, N.; Sakaguchi, T.; Sakai, M.; Sakai, S.; Samsonov, V.; Sanfratello, L.; Santo, R.; Sato, H. D.; Sato, S.; Sawada, S.; Schutz, Y.; Semenov, V.; Seto, R.; Shaw, M. R.; Shea, T. K.; Shibata, T.-A.; Shigaki, K.; Shiina, T.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, C. P.; Singh, V.; Sivertz, M.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sullivan, J. P.; Takagui, E. M.; Taketani, A.; Tamai, M.; Tanaka, K. H.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarján, P.; Tepe, J. D.; Thomas, T. L.; Tojo, J.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuruoka, H.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; van Hecke, H. W.; Velkovska, J.; Velkovsky, M.; Villatte, L.; Vinogradov, A. A.; Volkov, M. A.; Vznuzdaev, E.; Wang, X. R.; Watanabe, Y.; White, S. N.; Wohn, F. K.; Woody, C. L.; Xie, W.; Yang, Y.; Yanovich, A.; Yokkaichi, S.; Young, G. R.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

    2003-10-01

    We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at (sNN)=200 GeV measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5Au+Au, p+p, and e+e- collisions. This enhancement is limited to pT<5 GeV/c as deduced from the ratio of charged hadrons to π0 measured in the range 1.5

  12. X-ray Absorption Spectroscopy Combined with Time-Dependent Density Functional Theory Elucidates Differential Substitution Pathways of Au(I) and Au(III) with Zinc Fingers.

    PubMed

    Abbehausen, Camilla; de Paiva, Raphael Enoque Ferraz; Bjornsson, Ragnar; Gomes, Saulo Quintana; Du, Zhifeng; Corbi, Pedro Paulo; Lima, Frederico Alves; Farrell, Nicholas

    2018-01-02

    A combination of two elements' (Au, Zn) X-ray absorption spectroscopy (XAS) and time-dependent density functional theory (TD-DFT) allowed the elucidation of differential substitution pathways of Au(I) and Au(III) compounds reacting with biologically relevant zinc fingers (ZnFs). Gold L 3 -edge XAS probed the interaction of gold and the C-terminal Cys 2 HisCys finger of the HIV-1 nucleocapsid protein NCp7, and the Cys 2 His 2 human transcription factor Sp1. The use of model compounds helped assign oxidation states and the identity of the gold-bound ligands. The computational studies accurately reproduced the experimental XAS spectra and allowed the proposition of structural models for the interaction products at early time points. The direct electrophilic attack on the ZnF by the highly thiophilic Au(I) resulted in a linear P-Au-Cys coordination sphere after zinc ejection whereas for the Sp1, loss of PEt 3 results in linear Cys-Au-Cys or Cys-Au-His arrangements. Reactions with Au(III) compounds, on the other hand, showed multiple binding modes. Prompt reaction between [AuCl(dien)] 2+ and [Au(dien)(DMAP)] 3+ with Sp1 showed a partially reduced Au center and a final linear His-Au-His coordination. Differently, in the presence of NCp7, [AuCl(dien)] 2+ readily reduces to Au(I) and changes from square-planar to linear geometry with Cys-Au-His coordination, while [Au(dien)(DMAP)] 3+ initially maintains its Au(III) oxidation state and square-planar geometry and the same first coordination sphere. The latter is the first observation of a "noncovalent" interaction of a Au(III) complex with a zinc finger and confirms early hypotheses that stabilization of Au(III) occurs with N-donor ligands. Modification of the zinc coordination sphere, suggesting full or partial zinc ejection, is observed in all cases, and for [Au(dien)(DMAP)] 3+ this represents a novel mechanism for nucleocapsid inactivation. The combination of XAS and TD-DFT presents the first direct experimental

  13. Evidence of significant covalent bonding in Au(CN)(2)(-).

    PubMed

    Wang, Xue-Bin; Wang, Yi-Lei; Yang, Jie; Xing, Xiao-Peng; Li, Jun; Wang, Lai-Sheng

    2009-11-18

    The Au(CN)(2)(-) ion is the most stable Au compound known for centuries, yet a detailed understanding of its chemical bonding is still lacking. Here we report direct experimental evidence of significant covalent bonding character in the Au-C bonds in Au(CN)(2)(-) using photoelectron spectroscopy and comparisons with its lighter congeners, Ag(CN)(2)(-) and Cu(CN)(2)(-). Vibrational progressions in the Au-C stretching mode were observed for all detachment transitions for Au(CN)(2)(-), in contrast to the atomic-like transitions for Cu(CN)(2)(-), revealing the Au-C covalent bonding character. In addition, rich electronic structural information was obtained for Au(CN)(2)(-) by employing 118 nm detachment photons. Density functional theory and high-level ab initio calculations were carried out to understand the photoelectron spectra and obtain insight into the nature of the chemical bonding in the M(CN)(2)(-) complexes. Significant covalent character in the Au-C bonding due to the strong relativistic effects was revealed in Au(CN)(2)(-), consistent with its high stability.

  14. Au13(8e): A secondary block for describing a special group of liganded gold clusters containing icosahedral Au13 motifs

    NASA Astrophysics Data System (ADS)

    Xu, Wen Wu; Zeng, Xiao Cheng; Gao, Yi

    2017-05-01

    A grand unified model (GUM) has been proposed recently to understand structure anatomy and evolution of liganded gold clusters. In this work, besides the two types of elementary blocks (triangular Au3(2e) and tetrahedral Au4(2e)), we introduce a secondary block, namely, the icosahedral Au13 with 8e valence electrons, noted as Au13(8e). Using this secondary block, structural anatomy and evolution of a special group of liganded gold nanoclusters containing icosahedral Au13 motifs can be conveniently analyzed. In addition, a new ligand-protected cluster Au49(PR3)10(SR)15Cl2 is predicted to exhibit high chemical and thermal stability, suggesting likelihood of its synthesis in the laboratory.

  15. Au particle formation on the electron beam induced membrane

    NASA Astrophysics Data System (ADS)

    Choi, Seong Soo; Park, Myoung Jin; Han, Chul Hee; Oh, Sae-Joong; Kim, Sung-In; Park, Nam Kyou; Park, Doo-Jae; Choi, Soo Bong; Kim, Yong-Sang

    2017-02-01

    Recently the single molecules such as protein and deoxyribonucleic acid (DNA) have been successfully characterized by using a portable solidstate nanopore (MinION) with an electrical detection technique. However, there have been several reports about the high error rates of the fabricated nanopore device, possibly due to an electrical double layer formed inside the pore channel. The current DNA sequencing technology utilized is based on the optical detection method. In order to utilize the current optical detection technique, we will present the formation of the Au nano-pore with Au particle under the various electron beam irradiations. In order to provide the diffusion of Au atoms, a 2 keV electron beam irradiation has been performed During electron beam irradiations by using field emission scanning electron microscopy (FESEM), Au and C atoms would diffuse together and form the binary mixture membrane. Initially, the Au atoms diffused in the membrane are smaller than 1 nm, below the detection limit of the transmission electron microscopy (TEM), so that we are unable to observe the Au atoms in the formed membrane. However, after several months later, the Au atoms became larger and larger with expense of the smaller particles: Ostwald ripening. Furthermore, we also observe the Au crystalline lattice structure on the binary Au-C membrane. The formed Au crystalline lattice structures were constantly changing during electron beam imaging process due to Spinodal decomposition; the unstable thermodynamic system of Au-C binary membrane. The fabricated Au nanopore with an Au nanoparticle can be utilized as a single molecule nanobio sensor.

  16. Conductive Au nanowires regulated by silk fibroin nanofibers

    NASA Astrophysics Data System (ADS)

    Dong, Bo-Ju; Lu, Qiang

    2014-03-01

    Conductive Au-biopolymer composites have promising applications in tissue engineering such as nerve tissue regeneration. In this study, silk fibroin nanofibers were formed in aqueous solution by regulating silk self-assembly process and then used as template for Au nanowire fabrication. We performed the synthesis of Au seeds by repeating the seeding cycles for several times in order to increase the density of Au seeds on the nanofibers. After electroless plating, densely decorated Au seeds grew into irregularly shaped particles following silk nanofiber to fill the gaps between particles and finally form uniform continuous nanowires. The conductive property of the Au-silk fibroin nanowires was studied with current-voltage ( I-V) measurement. A typical ohmic behavior was observed, which highlighted their potential applications in nerve tissue regeneration.

  17. Identified baryon and meson distributions at large transverse momenta from Au + Au collisions at square root sNN=200 GeV.

    PubMed

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; Dephillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Gupta, N; Gutierrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lapointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; Levine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Nepali, N S; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Subba, N L; Sugarbaker, E; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van der Kolk, N; van Leeuwen, M; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2006-10-13

    Transverse momentum spectra of pi+/-, p, and p up to 12 GeV/c at midrapidity in centrality selected Au + Au collisions at square root sNN=200 GeV are presented. In central Au + Au collisions, both pi +/- and p(p) show significant suppression with respect to binary scaling at pT approximately >4 GeV/c. Protons and antiprotons are less suppressed than pi+/-, in the range 1.5 approximately < pT approximately < 6 GeV/c. The pi-/pi+ and p/p ratios show at most a weak pT dependence and no significant centrality dependence. The p/pi ratios in central Au + Au collisions approach the values in p + p and d + Au collisions at pT approximately >5 GeV/c. The results at high pT indicate that the partonic sources of pi+/-, p, and p have similar energy loss when traversing the nuclear medium.

  18. Synthesis of Au@Pt bimetallic nanoparticles with concave Au nanocuboids as seeds and their enhanced electrocatalytic properties in the ethanol oxidation reaction.

    PubMed

    Tan, Lingyu; Li, Lidong; Peng, Yi; Guo, Lin

    2015-12-18

    Herein, a new type of uniform and well-structured Au@Pt bimetallic nanoparticles (BNPs) with highly active concave Au nanocuboids (NCs) as seeds was successfully synthesized by using the classic seed-mediated method. Electrochemical measurements were conducted to demonstrate their greatly enhanced catalytic performance in the ethanol oxidation reaction (EOR). It was found that the electrochemical performance for Au@Pt BNPs with the concave Au NCs as seeds, which were enclosed by {611} high-index facets, could be seven times higher than that of the Au@Pt bimetallic nanoparticles with regular spherical Au NPs as seeds. Furthermore, our findings show that the morphology and electrocatalytic activity of the Au@Pt BNPs can be tuned simply by changing the compositional ratios of the growth solution. The lower the amount of H2PtCl6 used in the growth solution, the thinner the Pt shell grew, and the more high-index facets of concave Au NCs seeds were exposed in Au@Pt BNPs, leading to higher electrochemical activity. These as-prepared concave Au@Pt BNPs will open up new strategies for improving catalytic efficiency and reducing the use of the expensive and scarce resource of platinum in the ethanol oxidation reaction, and are potentially applicable as electrochemical catalysts for direct ethanol fuel cells.

  19. Synthesis of Au@Pt bimetallic nanoparticles with concave Au nanocuboids as seeds and their enhanced electrocatalytic properties in the ethanol oxidation reaction

    NASA Astrophysics Data System (ADS)

    Tan, Lingyu; Li, Lidong; Peng, Yi; Guo, Lin

    2015-12-01

    Herein, a new type of uniform and well-structured Au@Pt bimetallic nanoparticles (BNPs) with highly active concave Au nanocuboids (NCs) as seeds was successfully synthesized by using the classic seed-mediated method. Electrochemical measurements were conducted to demonstrate their greatly enhanced catalytic performance in the ethanol oxidation reaction (EOR). It was found that the electrochemical performance for Au@Pt BNPs with the concave Au NCs as seeds, which were enclosed by {611} high-index facets, could be seven times higher than that of the Au@Pt bimetallic nanoparticles with regular spherical Au NPs as seeds. Furthermore, our findings show that the morphology and electrocatalytic activity of the Au@Pt BNPs can be tuned simply by changing the compositional ratios of the growth solution. The lower the amount of H2PtCl6 used in the growth solution, the thinner the Pt shell grew, and the more high-index facets of concave Au NCs seeds were exposed in Au@Pt BNPs, leading to higher electrochemical activity. These as-prepared concave Au@Pt BNPs will open up new strategies for improving catalytic efficiency and reducing the use of the expensive and scarce resource of platinum in the ethanol oxidation reaction, and are potentially applicable as electrochemical catalysts for direct ethanol fuel cells.

  20. Stabilizing ultrasmall Au clusters for enhanced photoredox catalysis.

    PubMed

    Weng, Bo; Lu, Kang-Qiang; Tang, Zichao; Chen, Hao Ming; Xu, Yi-Jun

    2018-04-18

    Recently, loading ligand-protected gold (Au) clusters as visible light photosensitizers onto various supports for photoredox catalysis has attracted considerable attention. However, the efficient control of long-term photostability of Au clusters on the metal-support interface remains challenging. Herein, we report a simple and efficient method for enhancing the photostability of glutathione-protected Au clusters (Au GSH clusters) loaded on the surface of SiO 2 sphere by utilizing multifunctional branched poly-ethylenimine (BPEI) as a surface charge modifying, reducing and stabilizing agent. The sequential coating of thickness controlled TiO 2 shells can further significantly improve the photocatalytic efficiency, while such structurally designed core-shell SiO 2 -Au GSH clusters-BPEI@TiO 2 composites maintain high photostability during longtime light illumination conditions. This joint strategy via interfacial modification and composition engineering provides a facile guideline for stabilizing ultrasmall Au clusters and rational design of Au clusters-based composites with improved activity toward targeting applications in photoredox catalysis.

  1. Cross section of the 197Au(n,2n)196Au reaction

    NASA Astrophysics Data System (ADS)

    Kalamara, A.; Vlastou, R.; Kokkoris, M.; Diakaki, M.; Serris, M.; Patronis, N.; Axiotis, M.; Lagoyannis, A.

    2017-09-01

    The 197Au(n,2n)196Au reaction cross section has been measured at two energies, namely at 17.1 MeV and 20.9 MeV, by means of the activation technique, relative to the 27Al(n,α)24Na reference reaction cross section. Quasi-monoenergetic neutron beams were produced at the 5.5 MV Tandem T11/25 accelerator laboratory of NCSR "Demokritos", by means of the 3H(d,n)4He reaction, implementing a new Ti-tritiated target of ˜ 400 GBq activity. The induced γ-ray activity at the targets and reference foils has been measured with HPGe detectors. The cross section for the population of the second isomeric (12-) state m2 of 196Au was independently determined. Auxiliary Monte Carlo simulations were performed using the MCNP code. The present results are in agreement with previous experimental data and with theoretical calculations of the measured reaction cross sections, which were carried out with the use of the EMPIRE code.

  2. Neural synchronization during face-to-face communication.

    PubMed

    Jiang, Jing; Dai, Bohan; Peng, Danling; Zhu, Chaozhe; Liu, Li; Lu, Chunming

    2012-11-07

    Although the human brain may have evolutionarily adapted to face-to-face communication, other modes of communication, e.g., telephone and e-mail, increasingly dominate our modern daily life. This study examined the neural difference between face-to-face communication and other types of communication by simultaneously measuring two brains using a hyperscanning approach. The results showed a significant increase in the neural synchronization in the left inferior frontal cortex during a face-to-face dialog between partners but none during a back-to-back dialog, a face-to-face monologue, or a back-to-back monologue. Moreover, the neural synchronization between partners during the face-to-face dialog resulted primarily from the direct interactions between the partners, including multimodal sensory information integration and turn-taking behavior. The communicating behavior during the face-to-face dialog could be predicted accurately based on the neural synchronization level. These results suggest that face-to-face communication, particularly dialog, has special neural features that other types of communication do not have and that the neural synchronization between partners may underlie successful face-to-face communication.

  3. Mechanical properties and grindability of experimental Ti-Au alloys.

    PubMed

    Takahashi, Masatoshi; Kikuchi, Masafumi; Okuno, Osamu

    2004-06-01

    Experimental Ti-Au alloys (5, 10, 20 and 40 mass% Au) were made. Mechanical properties and grindability of the castings of the Ti-Au alloys were examined. As the concentration of gold increased to 20%, the yield strength and the tensile strength of the Ti-Au alloys became higher without markedly deteriorating their ductility. This higher strength can be explained by the solid-solution strengthening of the a titanium. The Ti-40%Au alloy became brittle because the intermetallic compound Ti3Au precipitated intensively near the grain boundaries. There was no significant difference in the grinding rate and grinding ratio among all the Ti-Au alloys and the pure titanium at any speed.

  4. First results on d+Au collisions from PHOBOS

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Noell, A.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sawicki, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Teng, R.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.; Zhang, J.

    2004-02-01

    We have measured transverse momentum distributions of charged hadrons produced in d+Au collisions at √SNN = 200 GeV, in the range 0.25 < pT < 6.0 GeV/c. With increasing collision centrality, the yield at high transverse momenta increases more rapidly than the overall particle density, leading to a strong modification of the spectral shape. This change in spectral shape is qualitatively different from observations in Au+Au collisions at the same energy. The results provide important information for discriminating between different models for the suppression of high-pT hadrons observed in Au+Au collisions.

  5. Deep sub-threshold ϕ production in Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Adamczewski-Musch, J.; Arnold, O.; Behnke, C.; Belounnas, A.; Belyaev, A.; Berger-Chen, J. C.; Biernat, J.; Blanco, A.; Blume, C.; Böhmer, M.; Bordalo, P.; Chernenko, S.; Chlad, L.; Deveaux, C.; Dreyer, J.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Filip, P.; Fonte, P.; Franco, C.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Golubeva, M.; Greifenhagen, R.; Guber, F.; Gumberidze, M.; Harabasz, S.; Heinz, T.; Hennino, T.; Hlavac, S.; Höhne, C.; Holzmann, R.; Ierusalimov, A.; Ivashkin, A.; Kämpfer, B.; Karavicheva, T.; Kardan, B.; Koenig, I.; Koenig, W.; Kolb, B. W.; Korcyl, G.; Kornakov, G.; Kotte, R.; Kühn, W.; Kugler, A.; Kunz, T.; Kurepin, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Lalik, R.; Lapidus, K.; Lebedev, A.; Lopes, L.; Lorenz, M.; Mahmoud, T.; Maier, L.; Mangiarotti, A.; Markert, J.; Maurus, S.; Metag, V.; Michel, J.; Mihaylov, D. M.; Morozov, S.; Müntz, C.; Münzer, R.; Naumann, L.; Nowakowski, K. N.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Petukhov, O.; Pietraszko, J.; Przygoda, W.; Ramos, S.; Ramstein, B.; Reshetin, A.; Rodriguez-Ramos, P.; Rosier, P.; Rost, A.; Sadovsky, A.; Salabura, P.; Scheib, T.; Schuldes, H.; Schwab, E.; Scozzi, F.; Seck, F.; Sellheim, P.; Siebenson, J.; Silva, L.; Sobolev, Yu. G.; Spataro, S.; Ströbele, H.; Stroth, J.; Strzempek, P.; Sturm, C.; Svoboda, O.; Szala, M.; Tlusty, P.; Traxler, M.; Tsertos, H.; Usenko, E.; Wagner, V.; Wendisch, C.; Wiebusch, M. G.; Wirth, J.; Zanevsky, Y.; Zumbruch, P.; Hades Collaboration

    2018-03-01

    We present data on charged kaons (K±) and ϕ mesons in Au(1.23A GeV)+Au collisions. It is the first simultaneous measurement of K- and ϕ mesons in central heavy-ion collisions below a kinetic beam energy of 10A GeV. The ϕ /K- multiplicity ratio is found to be surprisingly high with a value of 0.52 ± 0.16 and shows no dependence on the centrality of the collision. Consequently, the different slopes of the K+ and K- transverse-mass spectra can be explained solely by feed-down, which substantially softens the spectra of K- mesons. Hence, in contrast to the commonly adapted argumentation in literature, the different slopes do not necessarily imply diverging freeze-out temperatures of K+ and K- mesons caused by different couplings to baryons.

  6. A Perspective on Development Flight Instrumentation and Flight Test Analysis Plans for Ares I-X

    NASA Technical Reports Server (NTRS)

    Huebner, Lawrence D.; Richards, James S.; Brunty, Joseph A.; Smith, R. Marshall; Trombetta, Dominic R.

    2009-01-01

    NASA. s Constellation Program will take a significant step toward completion of the Ares I crew launch vehicle with the flight test of Ares I-X and completion of the Ares I-X post-flight evaluation. The Ares I-X flight test vehicle is an ascent development flight test that will acquire flight data early enough to impact the design and development of the Ares I. As the primary customer for flight data from the Ares I-X mission, Ares I has been the major driver in the definition of the Development Flight Instrumentation (DFI). This paper focuses on the DFI development process and the plans for post-flight evaluation of the resulting data to impact the Ares I design. Efforts for determining the DFI for Ares I-X began in the fall of 2005, and significant effort to refine and implement the Ares I-X DFI has been expended since that time. This paper will present a perspective in the development and implementation of the DFI. Emphasis will be placed on the process by which the list was established and changes were made to that list due to imposed constraints. The paper will also discuss the plans for the analysis of the DFI data following the flight and a summary of flight evaluation tasks to be performed in support of tools and models validation for design and development.

  7. K(892)* resonance production in Au+Au and p+p collisions at {radical}s{sub NN} = 200 GeV at RHIC

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adams, J.; Aggarwal, M.M.; Ahammed, Z.

    2004-12-09

    The short-lived K(892)* resonance provides an efficient tool to probe properties of the hot and dense medium produced in relativistic heavy-ion collisions. We report measurements of K* in {radical}s{sub NN} = 200 GeV Au+Au and p+p collisions reconstructed via its hadronic decay channels K(892)*{sup 0} {yields} K{pi} and K(892)*{sup +-} {yields} K{sub S}{sup 0}{pi}{sup +-} using the STAR detector at RHIC. The K*{sup 0} mass has been studied as function of p{sub T} in minimum bias p + p and central Au+Au collisions. The K* p{sub T} spectra for minimum bias p + p interactions and for Au+Au collisions inmore » different centralities are presented. The K*/K ratios for all centralities in Au+Au collisions are found to be significantly lower than the ratio in minimum bias p + p collisions, indicating the importance of hadronic interactions between chemical and kinetic freeze-outs. The nuclear modification factor of K* at intermediate p{sub T} is similar to that of K{sub S}{sup 0}, but different from {Lambda}. This establishes a baryon-meson effect over a mass effect in the particle production at intermediate p{sub T} (2 < p{sub T} {le} 4 GeV/c). A significant non-zero K*{sup 0} elliptic flow (v{sub 2}) is observed in Au+Au collisions and compared to the K{sub S}{sup 0} and {Lambda} v{sub 2}.« less

  8. Rationalization of Au concentration and distribution in AuNi@Pt core-shell nanoparticles for oxygen reduction reaction

    DOE PAGES

    An, Wei; Liu, Ping

    2015-09-18

    Improving the activity and stability of Pt-based core–shell nanocatalysts for proton exchange membrane fuel cells while lowering Pt loading has been one of the big challenges in electrocatalysis. Here, using density functional theory, we report the effect of adding Au as the third element to enhance the durability and activity of Ni@Pt core–shell nanoparticles (NPs) during the oxygen reduction reaction (ORR). Our results show that the durability and activity of a Ni@Pt NP can be finely tuned by controlling Au concentration and distribution. For a NiAu@Pt NP, the durability can be greatly promoted by thermodynamically favorable segregation of Au tomore » replace the Pt atoms at vertex, edge, and (100) facets on the shell, while still keeping the ORR activity on the active Pt(111) shell as high as that of Ni@Pt nanoparticles. Such behavior strongly depends on a direct interaction with the Ni interlayer. The results not only highlight the importance of interplay between surface strain on the shell and the interlayer–shell interaction in determining the durability and activity but also provide guidance on how to maximize the usage of Au to optimize the performance of core–shell (Pt) nanoparticles. As a result, such understanding has allowed us to discover a novel NiAu@Pt nanocatalyst for the ORR.« less

  9. Design Considerations for a Launch Vehicle Development Flight Instrumentation System

    NASA Technical Reports Server (NTRS)

    Johnson, Martin L.; Crawford, Kevin

    2011-01-01

    When embarking into the design of a new launch vehicle, engineering models of expected vehicle performance are always generated. While many models are well established and understood, some models contain design features that are only marginally known. Unfortunately, these analytical models produce uncertainties in design margins. The best way to answer these analytical issues is with vehicle level testing. The National Aeronautics and Space Administration respond to these uncertainties by using a vehicle level system called the Development Flight Instrumentation, or DFI. This DFI system can be simple to implement, with only a few measurements, or it may be a sophisticated system with hundreds of measurement and video, without a recording capability. From experience with DFI systems, DFI never goes away. The system is renamed and allowed to continue, in most cases. Proper system design can aid the transition to future data requirements. This paper will discuss design features that need to be considered when developing a DFI system for a launch vehicle. It will briefly review the data acquisition units, sensors, multiplexers and recorders, telemetry components and harnessing. It will present a reasonable set of requirements which should be implemented in the beginning of the program in order to start the design. It will discuss a simplistic DFI architecture that could be the basis for the next NASA launch vehicle. This will be followed by a discussion of the "experiences gained" from a past DFI system implementation, such as the very successful Ares I-X test flight. Application of these design considerations may not work for every situation, but they may direct a path toward success or at least make one pause and ask the right questions.

  10. Ag@Au concave cuboctahedra: A unique probe for monitoring Au-catalyzed reduction and oxidation reactions by surface-enhanced Raman spectroscopy

    DOE PAGES

    Zhang, Jiawei; Winget, Sarah A.; Wu, Yiren; ...

    2016-01-26

    In this paper, we report a facile synthesis of Ag@Au concave cuboctahedra by titrating aqueous HAuCl4 into a suspension of Ag cuboctahedra in the presence of ascorbic acid (AA), NaOH, and poly(vinylpyrrolidone) (PVP) at room temperature. Initially, the Au atoms derived from the reduction of Au 3+ by AA are conformally deposited on the entire surface of a Ag cuboctahedron. Upon the formation of a complete Au shell, however, the subsequently formed Au atoms are preferentially deposited onto the Au{100} facets, resulting in the formation of a Ag@Au cuboctahedron with concave structures at the sites of {111} facets. The concavemore » cuboctahedra embrace excellent SERS activity that is more than 70-fold stronger than that of the original Ag cuboctahedra at an excitation wavelength of 785 nm. The concave cuboctahedra also exhibit remarkable stability in the presence of an oxidant such as H 2O 2 because of the protection by a complete Au shell. These two unique attributes enable in-situ SERS monitoring of the reduction of 4-nitrothiophenol (4-NTP) to 4-aminothiophenol (4-ATP) by NaBH4 through a 4,4'-dimercaptoazobenzene ( trans-DMAB) intermediate and the subsequent oxidation of 4-ATP back to trans-DMAB upon the introduction of H 2O 2.« less

  11. Ag@Au concave cuboctahedra: A unique probe for monitoring Au-catalyzed reduction and oxidation reactions by surface-enhanced Raman spectroscopy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Jiawei; Winget, Sarah A.; Wu, Yiren

    In this paper, we report a facile synthesis of Ag@Au concave cuboctahedra by titrating aqueous HAuCl4 into a suspension of Ag cuboctahedra in the presence of ascorbic acid (AA), NaOH, and poly(vinylpyrrolidone) (PVP) at room temperature. Initially, the Au atoms derived from the reduction of Au 3+ by AA are conformally deposited on the entire surface of a Ag cuboctahedron. Upon the formation of a complete Au shell, however, the subsequently formed Au atoms are preferentially deposited onto the Au{100} facets, resulting in the formation of a Ag@Au cuboctahedron with concave structures at the sites of {111} facets. The concavemore » cuboctahedra embrace excellent SERS activity that is more than 70-fold stronger than that of the original Ag cuboctahedra at an excitation wavelength of 785 nm. The concave cuboctahedra also exhibit remarkable stability in the presence of an oxidant such as H 2O 2 because of the protection by a complete Au shell. These two unique attributes enable in-situ SERS monitoring of the reduction of 4-nitrothiophenol (4-NTP) to 4-aminothiophenol (4-ATP) by NaBH4 through a 4,4'-dimercaptoazobenzene ( trans-DMAB) intermediate and the subsequent oxidation of 4-ATP back to trans-DMAB upon the introduction of H 2O 2.« less

  12. The electric dipole moments in the ground states of gold oxide, AuO, and gold sulfide, AuS.

    PubMed

    Zhang, Ruohan; Yu, Yuanqin; Steimle, Timothy C; Cheng, Lan

    2017-02-14

    The B 2 Σ - - X 2 Π 3/2 (0,0) bands of a cold molecular beam sample of gold monoxide, AuO, and gold monosulfide, AuS, have been recorded at high resolution both field free and in the presence of a static electric field. The observed electric field induced splittings and shifts were analyzed to produce permanent electric dipole moments, μ→ el , of 2.94±0.06 D and 2.22±0.05 D for the X 2 Π 3/2 (v = 0) states of AuO and AuS, respectively. A molecular orbital correlation diagram is used to rationalize the trend in ground state μ→ el values for AuX (X = F, Cl, O, and S) molecules. The experimentally determined μ→ el are compared to those computed at the coupled-cluster singles and doubles (CCSD) level augmented with a perturbative inclusion of triple excitations (CCSD(T)) level of theory.

  13. Bedtime misalignment and progression of breast cancer.

    PubMed

    Hahm, Bong-Jin; Jo, Booil; Dhabhar, Firdaus S; Palesh, Oxana; Aldridge-Gerry, Arianna; Bajestan, Sepideh N; Neri, Eric; Nouriani, Bita; Spiegel, David; Zeitzer, Jamie M

    2014-03-01

    Disruption of circadian rhythms, which frequently occurs during night shift work, may be associated with cancer progression. The effect of chronotype (preference for behaviors such as sleep, work, or exercise to occur at particular times of day, with an associated difference in circadian physiology) and alignment of bedtime (preferred vs. habitual), however, have not yet been studied in the context of cancer progression in women with breast cancer. Chronotype and alignment of actual bedtime with preferred chronotype were examined using the Morningness-Eveningness Scale (MEQ) and sleep-wake log among 85 women with metastatic breast cancer. Their association with disease-free interval (DFI) was retrospectively examined using the Cox proportional hazards model. Median DFI was 81.9 months for women with aligned bedtimes ("going to bed at preferred bedtime") (n = 72), and 46.9 months for women with misaligned bedtimes ("going to bed later or earlier than the preferred bedtime") (n = 13) (log rank p = 0.001). In a multivariate Cox proportional hazard model, after controlling for other significant predictors of DFI, including chronotype (morning type/longer DFI; HR = 0.539, 95% CI = 0.320-0.906, p = 0.021), estrogen receptor (ER) status at initial diagnosis (negative/shorter DFI; HR = 2.169, 95% CI = 1.124-4.187, p = 0.028) and level of natural-killer cell count (lower levels/shorter DFI; HR = 1.641, 95% CI = 1.000-2.695, p = 0.050), misaligned bedtimes was associated with shorter DFI, compared to aligned bedtimes (HR = 3.180, 95% CI = 1.327-7.616, p = 0.018). Our data indicate that a misalignment of bedtime on a daily basis, an indication of circadian disruption, is associated with more rapid breast cancer progression as measured by DFI. Considering the limitations of small sample size and study design, a prospective study with a larger sample is necessary to explore their causal relationship and underlying

  14. Two Barium Gold Iodates: Syntheses, Structures, and Properties of Polar BaAu(IO3)5 and Nonpolar HBa4Au(IO3)12 Materials.

    PubMed

    Yang, Bing-Ping; Hu, Chun-Li; Mao, Fei-Fei; Xu, Xiang; Mao, Jiang-Gao

    2017-06-19

    Two new barium gold iodates, namely, BaAu(IO 3 ) 5 and HBa 4 Au(IO 3 ) 12 , have been prepared. BaAu(IO 3 ) 5 crystallizes in the polar space group Pca2 1 , whereas HBa 4 Au(IO 3 ) 12 crystallizes in the centrosymmetric space group P2 1 /c. BaAu(IO 3 ) 5 consists of unique polar [Au(IO 3 ) 4 ] - anions whose four iodate groups are located at both sides of the AuO 4 plane and the polarity points in the [001̅] direction. BaAu(IO 3 ) 5 displays strong second-harmonic-generation (SHG) effects about 0.6KTiOPO 4 (KTP) and is phase-matchable. Thermal properties, optical spectra analyses, and theoretical calculations are also reported.

  15. Exfoliation restacking route to Au nanoparticle-clay nanohybrids

    NASA Astrophysics Data System (ADS)

    Paek, Seung-Min; Jang, Jae-Up; Hwang, Seong-Ju; Choy, Jin-Ho

    2006-05-01

    A novel gold-pillared aluminosilicate (Au-PILC) were synthesized with positively charged gold nanoparticles capped by mercaptoammonium and exfoliated silicate layers. Gold nanoparticles were synthesized by NaBH4 reduction of AuCl4- in the presence of N,N,N-Trimethyl (11-mercaptoundecyl)ammonium (HS(CH2)11NMe3+) protecting ligand in an aqueous solution, and purified by dialysis. The resulting positively charged and water-soluble gold nanoparticles were hybridized with exfoliated silicate sheets by electrostatic interaction. The formation of Au clay hybrids could be easily confirmed by the powder X-ray diffraction with the increased basal spacing of clay upon insertion of Au nanoparticles. TEM image clearly revealed that the Au particles with an average size of 4 nm maintain their structure even after intercalation. The Au nanoparticles supported by clay matrix were found to be thermally more stable, suggesting that the Au nanoparticles were homogeneously protected with clay nanoplates. The present synthetic route could be further applicable to various hybrid systems between metal nanoparticles and clays.

  16. Template growth of Au, Ni and Ni–Au nanoclusters on hexagonal boron nitride/Rh(111): a combined STM, TPD and AES study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Fanglue; Huang, Dali; Yue, Yuan

    In this study, the template growth of Au, Ni, and Ni–Au bimetallic nanoclusters on hexagonal boron nitride/Rh(111), i.e. h-BN/Rh(111), was investigated via scanning tunneling microscopy (STM), temperature programmed-desorption (TPD), and Auger electron spectroscopy (AES). STM study shows that template growth of Au clusters on h-BN/Rh(111) forms mainly well-dispersed monolayer clusters. In contrast, Ni forms large multilayer clusters showing a relatively high diffusivity on h-BN/Rh(111) substrate. Ni–Au bimetallic clusters are effectively formed first by Au deposition followed by Ni deposition, with the Au clusters functioning as nucleation sites for the subsequently deposited Ni. Further structural analysis was carried out via TPDmore » and AES. The resulting TPD and AES data show the surface composition and charge transfer between Au and Ni of the bimetallic clusters. These results suggest that the h-BN/Rh(111) substrate represents a unique candidate for supporting Ni–Au bimetallic clusters in further catalytic reactions.« less

  17. Template growth of Au, Ni and Ni–Au nanoclusters on hexagonal boron nitride/Rh(111): a combined STM, TPD and AES study

    DOE PAGES

    Wu, Fanglue; Huang, Dali; Yue, Yuan; ...

    2017-09-12

    In this study, the template growth of Au, Ni, and Ni–Au bimetallic nanoclusters on hexagonal boron nitride/Rh(111), i.e. h-BN/Rh(111), was investigated via scanning tunneling microscopy (STM), temperature programmed-desorption (TPD), and Auger electron spectroscopy (AES). STM study shows that template growth of Au clusters on h-BN/Rh(111) forms mainly well-dispersed monolayer clusters. In contrast, Ni forms large multilayer clusters showing a relatively high diffusivity on h-BN/Rh(111) substrate. Ni–Au bimetallic clusters are effectively formed first by Au deposition followed by Ni deposition, with the Au clusters functioning as nucleation sites for the subsequently deposited Ni. Further structural analysis was carried out via TPDmore » and AES. The resulting TPD and AES data show the surface composition and charge transfer between Au and Ni of the bimetallic clusters. These results suggest that the h-BN/Rh(111) substrate represents a unique candidate for supporting Ni–Au bimetallic clusters in further catalytic reactions.« less

  18. Transformation of Au144(SCH2CH2Ph)60 to Au133(SPh-tBu)52 Nanomolecules: Theoretical and Experimental Study.

    PubMed

    Nimmala, Praneeth Reddy; Theivendran, Shevanuja; Barcaro, Giovanni; Sementa, Luca; Kumara, Chanaka; Jupally, Vijay Reddy; Apra, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Dass, Amala

    2015-06-04

    Ultrastable gold nanomolecule Au144(SCH2CH2Ph)60 upon etching with excess tert-butylbenzenethiol undergoes a core-size conversion and compositional change to form an entirely new core of Au133(SPh-tBu)52. This conversion was studied using high-resolution electrospray mass spectrometry which shows that the core size conversion is initiated after 22 ligand exchanges, suggesting a relatively high stability of the Au144(SCH2CH2Ph)38(SPh-tBu)22 intermediate. The Au144 → Au133 core size conversion is surprisingly different from the Au144 → Au99 core conversion reported in the case of thiophenol, -SPh. Theoretical analysis and ab initio molecular dynamics simulations show that rigid p-tBu groups play a crucial role by reducing the cluster structural freedom, and protecting the cluster from adsorption of exogenous and reactive species, thus rationalizing the kinetic factors that stabilize the Au133 core size. This 144-atom to 133-atom nanomolecule's compositional change is reflected in optical spectroscopy and electrochemistry.

  19. Na8Au9.8(4)Ga7.2 and Na17Au5.87(2)Ga46.63: The diversity of pseudo 5-fold symmetries in the Na-Au-Ga system

    NASA Astrophysics Data System (ADS)

    Smetana, Volodymyr; Corbett, John D.; Miller, Gordon J.

    2013-11-01

    The Na-rich part (~30% Na) of the Na-Au-Ga system between NaAu2, NaGa4, and Na22Ga39 has been found to contain the ternary phases Na8Au9.8(4)Ga7.2 (I) and Na17Au5.87(2)Ga46.63 (II), according to the results of single crystal X-ray diffraction measurements. I is orthorhombic, Cmcm, a=5.3040(1), b=24.519(5), c=14.573(3) Å, and contains a network of clusters with local 5-fold symmetry along the a-axis. Such clusters are frequent building units in decagonal quasicrystals and their approximants. II is rhombohedral, R3¯m, a=16.325(2), c=35.242(7) Å, and contains building blocks that are structurally identical to the Bergman-type clusters as well as fused icosahedral units known with active metals, triels and late transition elements. II also contains a polycationic network with elements of the clathrate V type structure. Tight-binding electronic structure calculations using linear muffin-tin-orbital (LMTO) methods on idealized models of I and II indicate that both compounds are metallic with evident pseudogaps at the corresponding Fermi levels. The overall Hamilton bond populations are generally dominated by Au-Ga and Au-Au bonds in I and by Ga-Ga bonds in II; moreover, the Na-Au and Na-Ga contributions in I are unexpectedly large, ~20% of the total. A similar involvement of sodium in covalent bonding has also been found in the electron-richer i-Na13Au12Ga15 quasicrystal approximant.

  20. First-principles study of Au-decorated carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ju, Weiwei; Li, Tongwei; Zhou, Qingxiao; Li, Haisheng; Li, Xiaohong

    2018-07-01

    The electronic structures and spin-orbit (SO) coupling of carbon nanotubes with adsorbed Au atoms are investigated based on density functional theory. Three kinds of zigzag single-walled CNT (8,0), (10,0) and (12,0) are selected. The Au atoms prefer to adsorb on the top of C atoms. The adsorption of Au atoms can introduce impurity states in the band gap, modifying the electronic properties of systems. Furthermore, the influence of SO coupling on these impurity states is also explored. Considerable SO splitting (∼130 meV) can be obtained. We find that the SO splitting decreases with the increase of the concentration of Au atoms, which can be ascribed to the interaction between Au atoms, suppressing the SO splitting. Our work provides imperative understanding on the electronic properties and SO coupling effect in Au-decorated CNTs.

  1. Transverse-momentum dependent modification of dynamic texture in central Au+Au collisions at sqrt(sNN) = 200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adams, J.; Aggarwal, M.M.; Ahammed, Z.

    2005-01-10

    Correlations in the hadron distributions produced in relativistic Au+Au collisions are studied in the discrete wavelet expansion method. The analysis is performed in the space of pseudorapidity (|{eta}| {le} 1) and azimuth (full 2{pi}) in bins of transverse momentum (p{sub t}) from 0.14 {le} p{sub t} {le} 2.1 GeV/c. In peripheral Au+Au collisions a correlation structure ascribed to minijet fragmentation is observed. It evolves with collision centrality and p{sub t} in a way not seen before which suggests strong dissipation of minijet fragmentation in the longitudinally-expanding medium.

  2. Tuning SPT-3G Transition-Edge-Sensor Electrical Properties with a Four-Layer Ti-Au-Ti-Au Thin-Film Stack

    NASA Astrophysics Data System (ADS)

    Carter, F. W.; Ade, P. A. R.; Ahmed, Z.; Anderson, A. J.; Austermann, J. E.; Avva, J. S.; Thakur, R. Basu; Bender, A. N.; Benson, B. A.; Carlstrom, J. E.; Cecil, T.; Chang, C. L.; Cliche, J. F.; Cukierman, A.; Denison, E. V.; de Haan, T.; Ding, J.; Divan, R.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Foster, A.; Gannon, R. N.; Gilbert, A.; Groh, J. C.; Halverson, N. W.; Harke-Hosemann, A. H.; Harrington, N. L.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Huang, N.; Irwin, K. D.; Jeong, O. B.; Jonas, M.; Khaire, T.; Kofman, A. M.; Korman, M.; Kubik, D.; Kuhlmann, S.; Kuo, C. L.; Kutepova, V.; Lee, A. T.; Lowitz, A. E.; Meyer, S. S.; Michalik, D.; Miller, C. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Noble, G. I.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Posada, C. M.; Rahlin, A.; Ruhl, J. E.; Saunders, L. J.; Sayre, J. T.; Shirley, I.; Shirokoff, E.; Smecher, G.; Sobrin, J. A.; Stan, L.; Stark, A. A.; Story, K. T.; Suzuki, A.; Tang, Q. Y.; Thompson, K. L.; Tucker, C.; Vale, L. R.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Yoon, K. W.; Young, M. R.

    2018-04-01

    We have developed superconducting Ti transition-edge sensors with Au protection layers on the top and bottom for the South Pole Telescope's third-generation receiver (a cosmic microwave background polarimeter, due to be upgraded this austral summer of 2017/2018). The base Au layer (deposited on a thin Ti glue layer) isolates the Ti from any substrate effects; the top Au layer protects the Ti from oxidation during processing and subsequent use of the sensors. We control the transition temperature and normal resistance of the sensors by varying the sensor width and the relative thicknesses of the Ti and Au layers. The transition temperature is roughly six times more sensitive to the thickness of the base Au layer than to that of the top Au layer. The normal resistance is inversely proportional to sensor width for any given film configuration. For widths greater than five micrometers, the critical temperature is independent of width.

  3. Centrality and collision system dependence of antiproton production from p+A to Au+Au collisions at AGS energies

    NASA Technical Reports Server (NTRS)

    Sako, H.; Ahle, L.; Akiba, Y.; Ashktorab, K.; Baker, M. D.; Beavis, D.; Britt, H. C.; Chang, J.; Chasman, C.; Chen, Z.; hide

    1997-01-01

    Antiproton production in heavy ion collisions reflects subtle interplay between initial production and absorption by nucleons. Because the AGS energies (10--20 A(center-dot)GeV/c) are close to the antiproton production threshold, antiproton may be sensitive to cooperative processes such as QGP and hadronic multi-step processes. On the other hand, antiproton has been proposed as a probe of baryon density due to large N(anti N) annihilation cross sections. Cascade models predict the maximum baryon density reaches about 10 times the normal nucleus density in central Au+Au collisions, where the strong antiproton absorption is expected. In this paper, the authors show systematic studies of antiproton production from p+A to Au+Au collisions.

  4. Distributions of charged hadrons associated with high transverse momentum particles in pp and Au+Au collisions at sqrt[sNN]=200 GeV.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Ganti, M S; Gaudichet, L; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grebenyuk, O; Gronstal, S; Grosnick, D; Guertin, S M; Gupta, A; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Hughes, E; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Levine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mischke, A; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, D A; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; Vandermolen, A M; Varma, R; Vasilevski, I; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Vznuzdaev, M; Waggoner, W; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Yuting, B; Zanevski, Y V; Zhang, H; Zhang, W M; Zhang, Z P; Zhaomin, Z P; Zizong, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2005-10-07

    Charged hadrons in [EQUATION: SEE TEXT] associated with particles of [EQUATION: SEE TEXT] are reconstructed in pp and Au+Au collisions at sqrt[sNN]=200 GeV. The associated multiplicity and p magnitude sum are found to increase from pp to central Au+Au collisions. The associated p distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed.

  5. Reconstruction of K*+/-(892) in Au +Au Collisions at √sNN = 200 GeV

    NASA Astrophysics Data System (ADS)

    Zheng, He; STAR Collaboration

    2016-09-01

    The Relativistic Heavy Ion Collider (RHIC) produces a hot, dense and deconfined Quantum ChromoDynamics (QCD) medium, called the quark-gluon plasma (QGP), with Au +Au collisions at √sNN = 200 GeV. The K*+/-(892) resonance is a short-lived particle with a lifetime shorter than the expected lifetime of the QGP. The K* production may provide an effective tool to probe the QGP properties, such as strangeness enhancement. Experimentally, K*+/- analysis is difficult and less studied previously because of large combinatorial background. In recent years, improvements in data sample statistics and particle identification capability promise better K*+/- measurements. In this presentation, we report the reconstruction of K*+/- resonance via the hadronic decay channel K*+/- (892) ->KS0π+/- as a function of transverse momentum (pT) up to 5 GeV/c for various collision centrality classes. The data are Au +Au collisions at √sNN = 200 GeV collected in the year 2011 run from the STAR experiment. Physics implications of our measurements will also be discussed. For the STAR collaboration.

  6. Plasmonic behaviour of sputtered Au nanoisland arrays

    NASA Astrophysics Data System (ADS)

    Tvarožek, V.; Szabó, O.; Novotný, I.; Kováčová, S.; Škriniarová, J.; Šutta, P.

    2017-02-01

    The specificity of the formation of Au sputtered nanoisland arrays (NIA) on a glass substrate or on a ZnO thin film doped by Ga is demonstrated. Statistical analysis of morphology images (SEM, AFM) exhibited the Log-normal distribution of the size (area) of nanoislands-their modus AM varied from 8 to 328 nm2 depending on the sputtering power density, which determined the nominal thicknesses in the range of 2-8 nm. Preferential polycrystalline texture (111) of Au NIA increased with the power density and after annealing. Transverse localised surface plasmonic resonance (LSPR; evaluated by transmission UV-vis spectroscopy) showed the red shift of the extinction peaks (Δl ≤ 100 nm) with an increase of the nominal thickness, and the blue shift (Δλ ≤ -65 nm) after annealing of Au NIA. The plasmonic behaviour of Au NIA was described by modification of a size-scaling universal model using the nominal thin film thickness as a technological scaling parameter. Sputtering of a Ti intermediate adhesive ultrathin film between the glass substrate and gold improves the adhesion of Au nanoislands as well as supporting the formation of more defined Au NIA structures of smaller dimensions.

  7. Gold surfaces and nanoparticles are protected by Au(0)–thiyl species and are destroyed when Au(I)–thiolates form

    PubMed Central

    Reimers, Jeffrey R.; Ford, Michael J.; Halder, Arnab; Ulstrup, Jens; Hush, Noel S.

    2016-01-01

    The synthetic chemistry and spectroscopy of sulfur-protected gold surfaces and nanoparticles is analyzed, indicating that the electronic structure of the interface is Au(0)–thiyl, with Au(I)–thiolates identified as high-energy excited surface states. Density-functional theory indicates that it is the noble character of gold and nanoparticle surfaces that destabilizes Au(I)–thiolates. Bonding results from large van der Waals forces, influenced by covalent bonding induced through s–d hybridization and charge polarization effects that perturbatively mix in some Au(I)–thiolate character. A simple method for quantifying these contributions is presented, revealing that a driving force for nanoparticle growth is nobleization, minimizing Au(I)–thiolate involvement. Predictions that Brust–Schiffrin reactions involve thiolate anion intermediates are verified spectroscopically, establishing a key feature needed to understand nanoparticle growth. Mixing of preprepared Au(I) and thiolate reactants always produces Au(I)–thiolate thin films or compounds rather than monolayers. Smooth links to O, Se, Te, C, and N linker chemistry are established. PMID:26929334

  8. Au 2PbP 2, Au 2TlP 2, and Au 2HgP 2: Ternary Gold Polyphosphides with Lead, Thallium, and Mercury in the Oxidation State Zero

    NASA Astrophysics Data System (ADS)

    Eschen, Marcus; Jeitschko, Wolfgang

    2002-05-01

    The polyphosphide Au2PbP2 was prepared by reaction of the elemental components using liquid lead as a reaction medium. Well-developed crystals were obtained after dissolving the matrix in hydrochloric acid. Their crystal structure was determined from four-circle X-ray diffractometer data: Cmcm, a=323.6(1) pm, b=1137.1(2) pm, c=1121.8(1) pm, Z=4, R=0.023 for 478 structure factors and 20 variable parameters. The structure contains zigzag chains of phosphorus atoms with a typical single-bond distance of 219.4(2) pm. The two different kinds of gold atoms are both in linear phosphorus coordination with typical single-bond distances of 232.6(2) and 234.2(2) pm, and the lead atoms have only metal neighbors (7 Au and 2 Pb). Accordingly, chemical bonding of the compound may be expressed by the formula (Au+1)2Pb±0(P-1)2. The corresponding thallium and mercury polyphosphides Au2TlP2 (a=324.1(1) pm, b=1136.1(1) pm, c=1122.1(1) pm) and Au2HgP2 (a=322.1(1) pm, b=1131.4(2) pm, c=1122.6(1) pm) were found to be almost isotypic with Au2PbP2. Their crystal structures were refined from single-crystal X-ray data to R=0.036 (682 F values, 25 variables) and R=0.026 (539 F values, 35 variables), respectively. The structure of these compounds may also be described as consisting of a three-dimensional network of condensed 8- and 10-membered Au2P6 and Au4P6 rings forming parallel channels, which are filled by the lead, thallium, and mercury atoms. The lead atoms are well localized in these channels, while the thallium and even more the mercury atoms occupy additional positions within these channels. Freshly prepared samples of Au2HgP2 show reproducibly slightly different axial ratios and larger cell volumes (ΔV=0.5%) than those after exposure of the samples to air for several days.

  9. Fabrication of Au25 (SG)18 -ZIF-8 Nanocomposites: A Facile Strategy to Position Au25 (SG)18 Nanoclusters Inside and Outside ZIF-8.

    PubMed

    Luo, Yucheng; Fan, Shiyan; Yu, Wenqian; Wu, Zili; Cullen, David A; Liang, Chaolun; Shi, Jianying; Su, Chengyong

    2018-02-01

    Multifunctional composite materials are currently highly desired for sustainable energy applications. A general strategy to integrate atomically precise Au 25 (SG) 18 with ZIF-8 (Zn(MeIm) 2 , MeIm = 2-methylimidazole), is developed via the typical Zn-carboxylate type of linkage. Au 25 (SG) 18 are uniformly encapsulated into a ZIF-8 framework (Au 25 (SG) 18 @ZIF-8) by coordination-assisted self-assembly. In contrast, Au 25 (SG) 18 integrated by simple impregnation is oriented along the outer surface of ZIF-8 (Au 25 (SG) 18 /ZIF-8). The porous structure and thermal stability of these nanocomposites are characterized by N 2 adsorption-desorption isothermal analysis and thermal gravimetric analysis. The distribution of Au 25 (SG) 18 in the two nanocomposites is confirmed by electron microscopy, and the accessibility of Au 25 (SG) 18 is evaluated by the 4-nitrophenol reduction reaction. The as-prepared nanocomposites retain the high porosity and thermal stability of the ZIF-8 matrix, while also exhibiting the desired catalytic and optical properties derived from the integrated Au 25 (SG) 18 nanoclusters (NCs). Au 25 (SG) 18 @ZIF-8 with isolated Au 25 sites is a promising heterogenous catalyst with size selectivity imparted by the ZIF-8 matrix. The structural distinction between Au 25 (SG) 18 @ZIF-8 and Au 25 (SG) 18 /ZIF-8 determines their different emission features, and provides a new strategy to adjust the optical behavior of Au 25 (SG) 18 for applications in bioimaging and biotherapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Famous face recognition, face matching, and extraversion.

    PubMed

    Lander, Karen; Poyarekar, Siddhi

    2015-01-01

    It has been previously established that extraverts who are skilled at interpersonal interaction perform significantly better than introverts on a face-specific recognition memory task. In our experiment we further investigate the relationship between extraversion and face recognition, focusing on famous face recognition and face matching. Results indicate that more extraverted individuals perform significantly better on an upright famous face recognition task and show significantly larger face inversion effects. However, our results did not find an effect of extraversion on face matching or inverted famous face recognition.

  11. Positron annihilation study of cavities in black Au films

    NASA Astrophysics Data System (ADS)

    Melikhova, O.; Čížek, J.; Hruška, P.; Vlček, M.; Procházka, I.; Anwand, W.; Novotný, M.; Bulíř, J.

    2017-01-01

    Defects in a black Au film were studied using variable energy positron annihilation spectroscopy. Black Au films exhibit porous morphology similar to cauliflower. This type of structure enhances the optical absorption due to a multiple reflections in the micro-cavities. A nanostructured black Au film was compared with conventional smooth Au films with high reflectivity. The black Au film exhibited a remarkably enhanced S-parameter in sub-surface region. This is caused by a narrow para-Positronium contribution to the annihilation peak.

  12. Study on the failure temperature of Ti/Pt/Au and Pt5Si2-Ti/Pt/Au metallization systems

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Han, Jianqiang; Yin, Yijun; Dong, Lizhen; Niu, Wenju

    2017-09-01

    The Ti/Pt/Au metallization system has an advantage of resisting KOH or TMAH solution etching. To form a good ohmic contact, the Ti/Pt/Au metallization system must be alloyed at 400 °C. However, the process temperatures of typical MEMS packaging technologies, such as anodic bonding, glass solder bonding and eutectic bonding, generally exceed 400 °C. It is puzzling if the Ti/Pt/Au system is destroyed during the subsequent packaging process. In the present work, the resistance of doped polysilicon resistors contacted by the Ti/Pt/Au metallization system that have undergone different temperatures and time are measured. The experimental results show that the ohmic contacts will be destroyed if heated to 500 °C. But if a 20 nm Pt film is sputtered on heavily doped polysilicon and alloyed at 700 °C before sputtering Ti/Pt/Au films, the Pt5Si2-Ti/Pt/Au metallization system has a higher service temperature of 500 °C, which exceeds process temperatures of most typical MEMS packaging technologies. Project supported by the National Natural Science Foundation of China (No. 61376114).

  13. Low-mass e+e- mass distributions from 1.23A GeV Au+Au collisions with HADES

    NASA Astrophysics Data System (ADS)

    Galatyuk, Tetyana; Hades Collaboration

    2017-11-01

    We present measurements of low-mass electron pairs for the Au+Au system based on a data sample of 2.6 billion events of the 40% most central collisions. In order to understand the microscopic structure of matter in the region of high baryochemical potential HADES pursues a strategy, which relies on systematic measurements of virtual photons emission in elementary and heavy-ion collisions. As of now, HADES has completed measurements of rare penetrating probes in p+p, n+p, C+C, p+Nb and Ar+KCl collisions. In continuation of a systematic investigation of the emissivity of strongly interacting matter, HADES has recently measured the dielectron emission in Au+Au collisions at 1.23A GeV beam energy. This measurement is part of the beam energy scan and marks lowest point in the excitation function of low-mass thermal dilepton radiation.

  14. Formation, Migration, and Reactivity of Au CO Complexes on Gold Surfaces

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Jun; McEntee, Monica; Tang, Wenjie

    2016-01-12

    Here, we report experimental as well as theoretical evidence that suggests Au CO complex formation upon the exposure of CO to active sites (step edges and threading dislocations) on a Au(111) surface. Room-temperature scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy, transmission infrared spectroscopy, and density functional theory calculations point to Au CO complex formation and migration. Room-temperature STM of the Au(111) surface at CO pressures in the range from 10^ 8 to 10^ 4 Torr (dosage up to 10^6 langmuir) indicates Au atom extraction from dislocation sites of the herringbone reconstruction, mobile Au CO complex formation and diffusion, and Aumore » adatom cluster formation on both elbows and step edges on the Au surface. The formation and mobility of the Au CO complex result from the reduced Au Au bonding at elbows and step edges leading to stronger Au CO bonding and to the formation of a more positively charged CO (CO +) on Au. These studies indicate that the mobile Au CO complex is involved in the Au nanoparticle formation and reactivity, and that the positive charge on CO increases due to the stronger adsorption of CO at Au sites with lower coordination numbers.« less

  15. Electronic Absorption and MCD Spectra for Pd(AuPPh(3))(8)(2+), Pt(AuPPh(3))(8)(2+), and Related Platinum-Centered Gold Cluster Complexes.

    PubMed

    Adrowski, Michael J.; Mason, W. Roy

    1997-03-26

    Electronic absorption and 7.0 T magnetic circular dichroism (MCD) spectra in the UV-vis region, 1.6 to approximately 4.0 &mgr;m(-)(1) (1 &mgr;m(-)(1) = 10(4) cm(-)(1)) are reported for [Pd(AuPPh(3))(8)](NO(3))(2) and [Pt(AuPPh(3))(8)](NO(3))(2) in acetonitrile solutions at room temperature. The MCD spectra are better resolved than the absorption spectra and consist of both A and B terms. The spectra are interpreted in terms of D(4)(d)() skeletal geometry and MO's that are approximated by 5s and 6s orbitals for Pd and Pt/Au atoms, respectively. The lowest energy excited configurations and states are attributed to intraframework (IF) Au(8)(2+) transitions. Evidence is also presented for Pt 5d --> Au 6s transitions in the MCD spectra for Pt(AuPPh(3))(8)(2+). Acetonitrile solution absorption and MCD spectra for the related Pt-centered cluster complexes [Pt(CO)(AuPPh(3))(8)](NO(3))(2), [Pt(AuP(p-tolyl)(3))(8)](NO(3))(2), [Pt(CuCl)(AuPPh(3))(8)](NO(3))(2), [Pt(AgNO(3))(AuPPh(3))(8)](NO(3))(2), [Pt(Hg)(2)(AuPPh(3))(8)](NO(3))(2), [Pt(HgCl)(2)(AuPPh(3))(8)](BF(4))(2), and [Pt(HgNO(3))(2)(AuPPh(3))(8)](BF(4))(2) are also reported and interpreted within the context of the model developed for the M(AuPPh(3))(8)(2+) complexes.

  16. High Activity of Au/K/TiO 2(110) for CO Oxidation: Alkali-Metal-Enhanced Dispersion of Au and Bonding of CO

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rodriguez, Jose A.; Grinter, David C.; Ramirez, Pedro J.

    In this paper, images from scanning tunneling microscopy show high mobility for potassium (K) on an oxidized TiO 2(110) surface. At low coverages, the alkali metal occupies mainly terrace sites of the o-TiO 2(110) system. The results of X-ray photoelectron spectroscopy indicate that K is fully ionized. The electron transferred from K to the titania affects the reactivity of this oxide, favoring the dispersion of Au particles on the terraces of the o-TiO 2(110) surface. When small coverages of K and Au are present on the o-TiO 2(110) system, only a few K–Au pairs are formed and the alkali metalmore » affects Au chemisorption mainly through the oxide interactions. Addition of K to Au/o-TiO 2(110) enhances the reactivity of the system, opening new reaction paths for the adsorption and oxidation of carbon monoxide. CO can undergo disproportionation (2CO → C ads + CO 2,ads) on K/o-TiO 2(110) and Au/K/o-TiO 2(110) surfaces. The Au–KO x interface binds CO much better than plain Au–TiO 2, increasing the surface coverage of CO and facilitating its oxidation. Kinetic tests show that K promotes CO oxidation on Au/TiO 2. Finally, turnover frequencies of 2.1 and 10.8 molecules (Au site) -1 s –1 were calculated for oxidation of CO on Au/o-TiO 2(110) and Au/K/o-TiO 2(110) catalysts, respectively.« less

  17. High Activity of Au/K/TiO 2(110) for CO Oxidation: Alkali-Metal-Enhanced Dispersion of Au and Bonding of CO

    DOE PAGES

    Rodriguez, Jose A.; Grinter, David C.; Ramirez, Pedro J.; ...

    2018-02-14

    In this paper, images from scanning tunneling microscopy show high mobility for potassium (K) on an oxidized TiO 2(110) surface. At low coverages, the alkali metal occupies mainly terrace sites of the o-TiO 2(110) system. The results of X-ray photoelectron spectroscopy indicate that K is fully ionized. The electron transferred from K to the titania affects the reactivity of this oxide, favoring the dispersion of Au particles on the terraces of the o-TiO 2(110) surface. When small coverages of K and Au are present on the o-TiO 2(110) system, only a few K–Au pairs are formed and the alkali metalmore » affects Au chemisorption mainly through the oxide interactions. Addition of K to Au/o-TiO 2(110) enhances the reactivity of the system, opening new reaction paths for the adsorption and oxidation of carbon monoxide. CO can undergo disproportionation (2CO → C ads + CO 2,ads) on K/o-TiO 2(110) and Au/K/o-TiO 2(110) surfaces. The Au–KO x interface binds CO much better than plain Au–TiO 2, increasing the surface coverage of CO and facilitating its oxidation. Kinetic tests show that K promotes CO oxidation on Au/TiO 2. Finally, turnover frequencies of 2.1 and 10.8 molecules (Au site) -1 s –1 were calculated for oxidation of CO on Au/o-TiO 2(110) and Au/K/o-TiO 2(110) catalysts, respectively.« less

  18. Charged particle multiplicity fluctuations in Au + Au collisions at √sNN = 200 GeV

    NASA Astrophysics Data System (ADS)

    Wozniak, Krzysztof; the PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J. L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wuosmaa, A. H.; Wysłouch, B.

    2004-08-01

    This paper presents the first PHOBOS results on charged particle multiplicity fluctuations measured for Au+Au collisions at the highest RHIC energy within a wide pseudorapidity range of |η| < 3. The dependence on collision geometry is removed in the analysis by using the normalized difference between the number of particles in separate η bins. We compare our data to HIJING model predictions.

  19. Development of sustainable precision farming systems for swine: estimating real-time individual amino acid requirements in growing-finishing pigs.

    PubMed

    Hauschild, L; Lovatto, P A; Pomar, J; Pomar, C

    2012-07-01

    The objective of this study was to develop and evaluate a mathematical model used to estimate the daily amino acid requirements of individual growing-finishing pigs. The model includes empirical and mechanistic model components. The empirical component estimates daily feed intake (DFI), BW, and daily gain (DG) based on individual pig information collected in real time. Based on DFI, BW, and DG estimates, the mechanistic component uses classic factorial equations to estimate the optimal concentration of amino acids that must be offered to each pig to meet its requirements. The model was evaluated with data from a study that investigated the effect of feeding pigs with a 3-phase or daily multiphase system. The DFI and BW values measured in this study were compared with those estimated by the empirical component of the model. The coherence of the values estimated by the mechanistic component was evaluated by analyzing if it followed a normal pattern of requirements. Lastly, the proposed model was evaluated by comparing its estimates with those generated by the existing growth model (InraPorc). The precision of the proposed model and InraPorc in estimating DFI and BW was evaluated through the mean absolute error. The empirical component results indicated that the DFI and BW trajectories of individual pigs fed ad libitum could be predicted 1 d (DFI) or 7 d (BW) ahead with the average mean absolute error of 12.45 and 1.85%, respectively. The average mean absolute error obtained with the InraPorc for the average individual of the population was 14.72% for DFI and 5.38% for BW. Major differences were observed when estimates from InraPorc were compared with individual observations. The proposed model, however, was effective in tracking the change in DFI and BW for each individual pig. The mechanistic model component estimated the optimal standardized ileal digestible Lys to NE ratio with reasonable between animal (average CV = 7%) and overtime (average CV = 14%) variation

  20. AuRu/AC as an effective catalyst for hydrogenation reactions

    DOE PAGES

    Villa, Alberto; Chan-Thaw, Carine E.; Campisi, Sebastiano; ...

    2015-03-23

    AuRu bimetallic catalysts have been prepared by sequential deposition of Au on Ru or vice versa obtaining different nanostructures: when Ru has been deposited on Au, a Au core–Ru shell has been observed, whereas the deposition of Au on Ru leads to a bimetallic phase with Ru enrichment on the surface. In the latter case, the unexpected Ru enrichment could be attributed to the weak adhesion of Ru on the carbon support, thus allowing Ru particles to diffuse on Au particles. Both structures result very active in catalysing the liquid phase hydrogenolysis of glycerol and levulinic acid but the activity,more » the selectivity and the stability depend on the structure of the bimetallic nanoparticles. Ru@Au/AC core–shell structure mostly behaved as the monometallic Ru, whereas the presence of bimetallic AuRu phase in Au@Ru/AC provides a great beneficial effect on both activity and stability.« less

  1. AU-FREDI - AUTONOMOUS FREQUENCY DOMAIN IDENTIFICATION

    NASA Technical Reports Server (NTRS)

    Yam, Y.

    1994-01-01

    The Autonomous Frequency Domain Identification program, AU-FREDI, is a system of methods, algorithms and software that was developed for the identification of structural dynamic parameters and system transfer function characterization for control of large space platforms and flexible spacecraft. It was validated in the CALTECH/Jet Propulsion Laboratory's Large Spacecraft Control Laboratory. Due to the unique characteristics of this laboratory environment, and the environment-specific nature of many of the software's routines, AU-FREDI should be considered to be a collection of routines which can be modified and reassembled to suit system identification and control experiments on large flexible structures. The AU-FREDI software was originally designed to command plant excitation and handle subsequent input/output data transfer, and to conduct system identification based on the I/O data. Key features of the AU-FREDI methodology are as follows: 1. AU-FREDI has on-line digital filter design to support on-orbit optimal input design and data composition. 2. Data composition of experimental data in overlapping frequency bands overcomes finite actuator power constraints. 3. Recursive least squares sine-dwell estimation accurately handles digitized sinusoids and low frequency modes. 4. The system also includes automated estimation of model order using a product moment matrix. 5. A sample-data transfer function parametrization supports digital control design. 6. Minimum variance estimation is assured with a curve fitting algorithm with iterative reweighting. 7. Robust root solvers accurately factorize high order polynomials to determine frequency and damping estimates. 8. Output error characterization of model additive uncertainty supports robustness analysis. The research objectives associated with AU-FREDI were particularly useful in focusing the identification methodology for realistic on-orbit testing conditions. Rather than estimating the entire structure, as is

  2. Photon interferometry of Au+Au collisions at the BNL Relativistic Heavy-Ion Collider.

    PubMed

    Bass, Steffen A; Müller, Berndt; Srivastava, Dinesh K

    2004-10-15

    We calculate the two-body correlation function of direct photons produced in central Au+Au collisions at the Relativistic Heavy-Ion Collider. Our calculation includes contributions from the early preequilibrium phase in which photons are produced via hard parton scatterings as well as radiation of photons from a thermalized quark-gluon plasma and the subsequent expanding hadron gas. We find that high energy photon interferometry provides a faithful probe of the details of the space-time evolution and of the early reaction stages of the system.

  3. The relationship between post-thaw sperm DNA integrity and non-return rate among Norwegian cross-bred rams.

    PubMed

    Nordstoga, A B; Krogenæs, A; Nødtvedt, A; Farstad, W; Waterhouse, K

    2013-04-01

    With the aim of investigating the relationship between sperm DNA integrity and non-return rate (NRR) among Norwegian cross-bred rams, semen from 15 individuals was examined by flow cytometry. Sperm Chromatin Structure Assay (SCSA) quantifies the proportion of spermatozoa with denatured DNA after in situ acid treatment, and the four parameters % DFI, % HDS, MEAN DFI and SD DFI are all different measures of DNA denaturation and maturation. Field fertility, reported as NRR 25 days after insemination was based on all inseminations from a large-scale breeding programme and supplied by the Norwegian Association of Sheep and Goat Farmers. From each ram, four straws from four different weeks of the breeding season were analysed, and the associations between 25-day NRR and the mean of the four SCSA parameters were tested using a logistic regression model. The results revealed no association between fertility and % DFI or % HDS, while SD DFI and MEAN DFI showed a significant negative association with NRR. Further, the SCSA values varied significantly between ejaculates within ram among some of the rams in the study. However, no significant association was seen between these intra-individual differences in sperm DNA integrity and NRR. In conclusion, this study suggests an association between sperm DNA integrity and NRR for rams. However, further research must be conducted to confirm these findings and determine whether sperm DNA assessments can be applied to predict ram fertility. © 2012 Blackwell Verlag GmbH.

  4. Electron transfer catalysis with monolayer protected Au25 clusters

    NASA Astrophysics Data System (ADS)

    Antonello, Sabrina; Hesari, Mahdi; Polo, Federico; Maran, Flavio

    2012-08-01

    Au25L18 (L = S(CH2)2Ph) clusters were prepared and characterized. The resulting monodisperse clusters were reacted with bis(pentafluorobenzoyl) peroxide in dichloromethane to form Au25L18+ quantitatively. The kinetics and thermodynamics of the corresponding electron transfer (ET) reactions were characterized via electrochemistry and thermochemical calculations. Au25L18+ was used in homogeneous redox catalysis experiments with a series of sym-substituted benzoyl peroxides, including the above peroxide, bis(para-cyanobenzoyl) peroxide, dibenzoyl peroxide, and bis(para-methoxybenzoyl) peroxide. Peroxide dissociative ET was catalyzed using both the Au25L18/Au25L18- and the Au25L18+/Au25L18 redox couples as redox mediators. Simulation of the CV curves led to determination of the ET rate constant (kET) values for concerted dissociative ET to the peroxides. The ET free energy ΔG° could be estimated for all donor-acceptor combinations, leading to observation of a nice activation-driving force (log kETvs. ΔG°) relationship. Comparison with the kET obtained using a ferrocene-type donor with a formal potential similar to that of Au25L18/Au25L18- showed that the presence of the capping monolayer affects the ET rate rather significantly, which is attributed to the intrinsic nonadiabaticity of peroxide acceptors.Au25L18 (L = S(CH2)2Ph) clusters were prepared and characterized. The resulting monodisperse clusters were reacted with bis(pentafluorobenzoyl) peroxide in dichloromethane to form Au25L18+ quantitatively. The kinetics and thermodynamics of the corresponding electron transfer (ET) reactions were characterized via electrochemistry and thermochemical calculations. Au25L18+ was used in homogeneous redox catalysis experiments with a series of sym-substituted benzoyl peroxides, including the above peroxide, bis(para-cyanobenzoyl) peroxide, dibenzoyl peroxide, and bis(para-methoxybenzoyl) peroxide. Peroxide dissociative ET was catalyzed using both the Au25L18/Au25L18- and

  5. Face recognition system and method using face pattern words and face pattern bytes

    DOEpatents

    Zheng, Yufeng

    2014-12-23

    The present invention provides a novel system and method for identifying individuals and for face recognition utilizing facial features for face identification. The system and method of the invention comprise creating facial features or face patterns called face pattern words and face pattern bytes for face identification. The invention also provides for pattern recognitions for identification other than face recognition. The invention further provides a means for identifying individuals based on visible and/or thermal images of those individuals by utilizing computer software implemented by instructions on a computer or computer system and a computer readable medium containing instructions on a computer system for face recognition and identification.

  6. Transverse-momentum and collision-energy dependence of high-pT hadron suppression in Au+Au collisions at ultrarelativistic energies.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Drees, K A; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Gutierrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2003-10-24

    We report high statistics measurements of inclusive charged hadron production in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. A large, approximately constant hadron suppression is observed in central Au+Au collisions for 5

  7. Fabrication of Au 25(SG) 18–ZIF-8 Nanocomposites: A Facile Strategy to Position Au 25(SG) 18 Nanoclusters Inside and Outside ZIF-8

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luo, Yucheng; Fan, Shiyan; Yu, Wenqian

    Multifunctional composite materials are currently highly desired for sustainable energy applications. A general strategy to integrate atomically precise Au 25(SG) 18 with ZIF-8 (Zn(MeIm) 2, MeIm = 2-methylimidazole), is developed in this paper via the typical Zn-carboxylate type of linkage. Au 25(SG) 18 are uniformly encapsulated into a ZIF-8 framework (Au 25(SG) 18@ZIF-8) by coordination-assisted self-assembly. In contrast, Au 25(SG) 18 integrated by simple impregnation is oriented along the outer surface of ZIF-8 (Au 25(SG) 18/ZIF-8). The porous structure and thermal stability of these nanocomposites are characterized by N 2 adsorption–desorption isothermal analysis and thermal gravimetric analysis. The distribution ofmore » Au 25(SG) 18 in the two nanocomposites is confirmed by electron microscopy, and the accessibility of Au 25(SG) 18 is evaluated by the 4-nitrophenol reduction reaction. The as-prepared nanocomposites retain the high porosity and thermal stability of the ZIF-8 matrix, while also exhibiting the desired catalytic and optical properties derived from the integrated Au 25(SG) 18 nanoclusters (NCs). Au 25(SG) 18@ZIF-8 with isolated Au 25 sites is a promising heterogenous catalyst with size selectivity imparted by the ZIF-8 matrix. Finally, the structural distinction between Au 25(SG) 18@ZIF-8 and Au 25(SG) 18/ZIF-8 determines their different emission features, and provides a new strategy to adjust the optical behavior of Au 25(SG) 18 for applications in bioimaging and biotherapy.« less

  8. Fabrication of Au 25(SG) 18–ZIF-8 Nanocomposites: A Facile Strategy to Position Au 25(SG) 18 Nanoclusters Inside and Outside ZIF-8

    DOE PAGES

    Luo, Yucheng; Fan, Shiyan; Yu, Wenqian; ...

    2017-12-22

    Multifunctional composite materials are currently highly desired for sustainable energy applications. A general strategy to integrate atomically precise Au 25(SG) 18 with ZIF-8 (Zn(MeIm) 2, MeIm = 2-methylimidazole), is developed in this paper via the typical Zn-carboxylate type of linkage. Au 25(SG) 18 are uniformly encapsulated into a ZIF-8 framework (Au 25(SG) 18@ZIF-8) by coordination-assisted self-assembly. In contrast, Au 25(SG) 18 integrated by simple impregnation is oriented along the outer surface of ZIF-8 (Au 25(SG) 18/ZIF-8). The porous structure and thermal stability of these nanocomposites are characterized by N 2 adsorption–desorption isothermal analysis and thermal gravimetric analysis. The distribution ofmore » Au 25(SG) 18 in the two nanocomposites is confirmed by electron microscopy, and the accessibility of Au 25(SG) 18 is evaluated by the 4-nitrophenol reduction reaction. The as-prepared nanocomposites retain the high porosity and thermal stability of the ZIF-8 matrix, while also exhibiting the desired catalytic and optical properties derived from the integrated Au 25(SG) 18 nanoclusters (NCs). Au 25(SG) 18@ZIF-8 with isolated Au 25 sites is a promising heterogenous catalyst with size selectivity imparted by the ZIF-8 matrix. Finally, the structural distinction between Au 25(SG) 18@ZIF-8 and Au 25(SG) 18/ZIF-8 determines their different emission features, and provides a new strategy to adjust the optical behavior of Au 25(SG) 18 for applications in bioimaging and biotherapy.« less

  9. Corrosion behavior and microstructures of experimental Ti-Au alloys.

    PubMed

    Takahashi, Masatoshi; Kikuchi, Masafumi; Takada, Yukyo; Okuno, Osamu; Okabe, Toru

    2004-06-01

    Anodic polarization was performed in 0.9% NaCl and 1% lactic acid solutions to characterize the relationship between the corrosion behavior and microstructures of cast Ti-Au (5-40%) alloys. An abrupt increase in the current density occurred at approximately 0.6 V vs. SCE for the 30% and 40% Au alloys in the 0.9% NaCl solution. The microstructures after corrosion testing indicated that this breakdown may have been caused by the preferential dissolution of the Ti3Au. However, the potential for preferential dissolution was higher than the breakdown potential of stainless steel or Co-Cr alloy, which meant that the corrosion resistance of the Ti-Au alloys was superior. In 1% lactic acid solution, the corrosion resistance of the Ti-Au alloys was excellent, with no breakdown at any composition. In the present test solutions, the Ti-Au alloys up to 20% Au had good corrosion resistance comparable to that for pure titanium.

  10. Measurement of D 0 Azimuthal Anisotropy at Midrapidity in Au + Au Collisions at s N N = 200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.

    In this paper, we report the first measurement of the elliptic anisotropy (v2) of the charm meson D 0 at midrapidity (|y| < 1) in Au + Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$ = 200 GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D 0 v 2 in 0%–80% centrality Au + Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (p T) of less than 4 GeV/c . The D 0 v 2 as a function of transverse kinetic energy (m T - m 0 , where m T = $$\\sqrt{p}$$$2\\atop{T}$$ + m$$2\\atop{0}$$) is consistent with that of light mesons in 10%–40% centrality Au + Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. In conclusion, several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2πTD s) in the range of ~2–12 , are able to simultaneously reproduce our D 0 v 2 result and our previously published results for the D 0 nuclear modification factor.« less

  11. Measurement of D 0 Azimuthal Anisotropy at Midrapidity in Au + Au Collisions at s N N = 200 GeV

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2017-05-26

    In this paper, we report the first measurement of the elliptic anisotropy (v2) of the charm meson D 0 at midrapidity (|y| < 1) in Au + Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$ = 200 GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D 0 v 2 in 0%–80% centrality Au + Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (p T) of less than 4 GeV/c . The D 0 v 2 as a function of transverse kinetic energy (m T - m 0 , where m T = $$\\sqrt{p}$$$2\\atop{T}$$ + m$$2\\atop{0}$$) is consistent with that of light mesons in 10%–40% centrality Au + Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. In conclusion, several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2πTD s) in the range of ~2–12 , are able to simultaneously reproduce our D 0 v 2 result and our previously published results for the D 0 nuclear modification factor.« less

  12. RHIC Au beam in Run 2014

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, S. Y.

    Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014more » is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.« less

  13. Ordered arrays of Au catalysts by FIB assisted heterogeneous dewetting.

    PubMed

    Benkouider, A; Ronda, A; David, T; Favre, L; Abbarchi, M; Naffouti, M; Osmond, J; Delobbe, A; Sudraud, P; Berbezier, I

    2015-12-18

    Synthesizing Au0.8Si0.2 nanocatalysts that are homogeneous in size and have controlled position is becoming a challenging and crucial prequisite for the fabrication of ordered semiconductor nanowires. In this study, Au0.8Si0.2 nanocatalysts are synthesized via dewetting of Au layers on Si(111) during thermal annealing in an ultra-high vacuum. In the first part of the paper, the mechanism of homogeneous dewetting is analyzed as a function of the Au-deposited thickness (h Au). We distinguish three different dewetting regimes: (I) for a low thickness ([Formula: see text]), a submonolyer coverage of Au is stabilized and there is no dewetting. (II) For an intermediate thickness ([Formula: see text]), there is both dewetting and Au0.8Si0.2 phase formation. The size and density of the Au0.8Si0.2 clusters are directly related to h Au. When cooling down to room temperature, the clusters decompose and reject the Si at the Au/Si substrate interface. (III) For a large thickness ([Formula: see text]), only dewetting takes place, without forming AuSi clusters. In this regime, the dewetting is kinetically controlled by the self-diffusion of Au (activation energy ∼0.43 eV) without evidence of an Si-alloying effect. As a practical consequence, when relying solely on the homogeneous dewetting of Au/Si(111) to form the Au0.8Si0.2 catalysts (without a supply of Si atoms from vapor), regime II should be used to obtain good size and density control. In the second part of the paper, a process for ordering the catalysts using focused ion beam-(FIB) assisted dewetting (heterogeneous dewetting) is developed. We show that no matter what the FIB milling conditions and the Au nominal thickness are, dewetting is promoted by ion beam irradiation and is accompanied by the formation of Au0.8Si0.2 droplets. The droplets preferentially form on the patterned areas, while in similar annealing conditions, they do not form on the unpatterned areas. This behavior is attributed to the larger Au

  14. A comparative study of the Au + H{sub 2}, Au{sup +} + H{sub 2}, and Au{sup −} + H{sub 2} systems: Potential energy surfaces and dynamics of reactive collisions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dorta-Urra, Anaís; Zanchet, Alexandre; Roncero, Octavio

    2015-04-21

    In order to study the Au{sup −} + H{sub 2} collision, a new global potential energy surface (PES) describing the ground electronic state of AuH{sub 2}{sup −} system is developed and compared with the PESs of the neutral [Zanchet et al., J. Chem. Phys. 132, 034301 (2010)] and cationic systems [Anaís et al., J. Chem. Phys. 135, 091102 (2011)]. We found that Au{sup −} − H{sub 2} presents a H-Au-H insertion minimum attributed to the stabilization of the LUMO 3b{sub 2} orbital, which can be considered as the preamble of the chemisorption well appearing in larger gold clusters. While themore » LUMO orbital is stabilized, the HOMO 6a{sub 1} is destabilized, creating a barrier at the geometry where the energy orbitals’ curves are crossing. In the anion, this HOMO is doubly occupied, while in the neutral system is half-filled and completely empty in the cation, explaining the gradual disappearance of the well and the barrier as the number of electrons decreases. The cation presents a well in the entrance channel partially explained by electrostatic interactions. The three systems’ reactions are highly endothermic, by 1.66, 2.79, and 3.23 eV for AuH, AuH{sup +}, and AuH{sup −} products, respectively. The reaction dynamics is studied using quasi-classical trajectory method for the three systems. The one corresponding to the anionic system is new in this work. Collision energies between 1.00 and 8.00 eV, measured for the cation, are in good agreement with the simulated cross section for the AuH{sup +}. It was also found that the total fragmentation, in three atoms, competes becoming dominant at sufficiently high energy. Here, we study the competition between the two different reaction pathways for the anionic, cationic, and neutral species, explaining the differences using a simple model based on the topology of the potential energy surfaces.« less

  15. Non-flow correlations and elliptic flow fluctuations in Au+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

    2010-03-01

    This article presents results on event-by-event elliptic flow fluctuations in Au+Au collisions at sNN= 200 GeV, where the contribution from non-flow correlations has been subtracted. An analysis method is introduced to measure non-flow correlations, relying on the assumption that non-flow correlations are most prominent at short ranges (|Δη|<2). Assuming that non-flow correlations are of the order that is observed in p+p collisions for long-range correlations (|Δη|>2), relative elliptic flow fluctuations of approximately 30-40% are observed. These results are consistent with predictions based on spatial fluctuations of the participating nucleons in the initial nuclear overlap region. It is found that the long-range non-flow correlations in Au+Au collisions would have to be more than an order of magnitude stronger compared to the p+p data to lead to the observed azimuthal anisotropy fluctuations with no intrinsic elliptic flow fluctuations.

  16. Optical and electrical properties of colloidal (spherical Au)-(spinel ferrite nanorod) heterostructures

    NASA Astrophysics Data System (ADS)

    George, Chandramohan; Genovese, Alessandro; Qiao, Fen; Korobchevskaya, Kseniya; Comin, Alberto; Falqui, Andrea; Marras, Sergio; Roig, Anna; Zhang, Yang; Krahne, Roman; Manna, Liberato

    2011-11-01

    We report here a simple synthetic route to Au-FexOy heterostructures in which spinel ferrite (FexOy) grows as a nanorod on a spherical gold (Au) seed. The large red shift in the plasmon resonance in the heterostructures could be explained by a dielectric effect (although we could not entirely exclude a contribution due to electron transfer from Au to defect states at the Au-FexOy interface), while the magnetic properties of the Au-FexOy heterostructures were basically the same as those of the corresponding nanocrystals after Au leaching. In films of Au-FexOy heterostructures the electrical conductivity appeared to be mediated by the Au domains.We report here a simple synthetic route to Au-FexOy heterostructures in which spinel ferrite (FexOy) grows as a nanorod on a spherical gold (Au) seed. The large red shift in the plasmon resonance in the heterostructures could be explained by a dielectric effect (although we could not entirely exclude a contribution due to electron transfer from Au to defect states at the Au-FexOy interface), while the magnetic properties of the Au-FexOy heterostructures were basically the same as those of the corresponding nanocrystals after Au leaching. In films of Au-FexOy heterostructures the electrical conductivity appeared to be mediated by the Au domains. Electronic supplementary information (ESI) available: TEM/HRTEM images of (i) aliquots at the earliest stages of the growth of Au-FexOy HSs; (ii) Au-FexOy HSs synthesized at low DDAB concentrations; (iii) spherical iron oxide nanocrystals synthesized under the same conditions as the HSs, but in the absence of Au seeds; (iv) Au-FexOy urchin like nanostructures, also after attempts to leach out Au; (v) Au-FexOy HSs after treatment with hydrazine; (vi) FexOy HSs after Au leaching from Au-FexOy HSs; additional optical absorption spectra; additional I-V curves, also from films made of Au-FexOy dumbbells; and additional SEM images; vii) X-ray diffraction (XRD) pattern of a sample of Au

  17. Measurement of D0 Azimuthal Anisotropy at Midrapidity in Au +Au Collisions at √{sN N }=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration

    2017-05-01

    We report the first measurement of the elliptic anisotropy (v2) of the charm meson D0 at midrapidity (|y |<1 ) in Au +Au collisions at √{sN N}=200 GeV . The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D0 v2 in 0%-80% centrality Au +Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (pT) of less than 4 GeV /c . The D0 v2 as a function of transverse kinetic energy (mT-m0, where mT=√{pT2+m02 }) is consistent with that of light mesons in 10%-40% centrality Au +Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. Several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2 π T Ds) in the range of ˜2 - 12 , are able to simultaneously reproduce our D0 v2 result and our previously published results for the D0 nuclear modification factor.

  18. Kaon femtoscopy in Au+Au collisions at √SNN = 200 GeV at the STAR experiment

    NASA Astrophysics Data System (ADS)

    Lidrych, Jindřich

    2018-02-01

    In this proceedings, the STAR preliminary results on femtoscopic correlations of identical kaons from Au+Au collisions at =200 GeV are presented. The measured kaon source radii are studied as a function of collision energy as well as centrality and transverse pair mass mT. In addition, extracted kaon blast-wave freeze-out parameters are presented.

  19. Molecular dynamics simulations on the effect of size and shape on the interactions between negative Au18(SR)14, Au102(SR)44 and Au144(SR)60 nanoparticles in physiological saline.

    PubMed

    Villareal, Oscar D; Rodriguez, Roberto A; Yu, Lili; Wambo, Thierry O

    2016-08-20

    Molecular dynamics simulations employing all-atom force fields have become a reliable way to study binding interactions quantitatively for a wide range of systems. In this work, we employ two recently developed methods for the calculation of dissociation constants K D between gold nanoparticles (AuNPs) of different sizes in a near-physiological environment through the potential of mean force (PMF) formalism: the method of geometrical restraints developed by Woo et al. and formalized by Gumbart et al. and the method of hybrid Steered Molecular Dynamics (hSMD). Obtaining identical results (within the margin of error) from both approaches on the negatively charged Au 18 (SR) 14 NP, functionalized by the negatively charged 4-mercapto-benzoate (pMBA) ligand, we draw parallels between their energetic and entropic interactions. By applying the hSMD method on Au 102 (SR) 44 and Au 144 (SR) 60 , both of them near-spherical in shape and functionalized by pMBA, we study the effects of size and shape on the binding interactions. Au 18 binds weakly with K D = 13 mM as a result of two opposing effects: its large surface curvature hindering the formation of salt bridges, and its large ligand density on preferential orientations favoring their formation. On the other hand, Au 102 binds more strongly with K D = 30 μM and Au 144 binds the strongest with K D = 3.2 nM .

  20. Virtual & Real Face to Face Teaching

    ERIC Educational Resources Information Center

    Teneqexhi, Romeo; Kuneshka, Loreta

    2016-01-01

    In traditional "face to face" lessons, during the time the teacher writes on a black or white board, the students are always behind the teacher. Sometimes, this happens even in the recorded lesson in videos. Most of the time during the lesson, the teacher shows to the students his back not his face. We do not think the term "face to…

  1. Role of Au-C Interactions on the Catalytic Activity of Au Nanoparticles Supported on TiC(001) Towards Molecular Oxygen Dissociation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rodriguez, J.A.; Feria, L.; Jirsak, T.

    2010-03-10

    High-resolution photoemission and density functional calculations on realistic slab surface models were used to study the interaction and subsequent dissociation of O{sub 2} with Au nanoparticles supported on TiC(001). The photoemission results indicate that at 150 K O{sub 2} adsorbs molecularly on the supported gold nanoparticles, and upon heating to temperatures above 200 K the O{sub 2} {yields} 2O reaction takes place with migration of atomic oxygen to the TiC(001) substrate. The addition of Au to TiC(001) substantially enhances the rate of O{sub 2} dissociation at room temperature. The reactivity of Au nanoparticles supported on TiC(001) toward O{sub 2} dissociationmore » is much larger than that of similar nanoparticles supported either on TiO{sub 2}(110) or MgO(001) surfaces, where the cleavage of O-O bonds is very difficult. Density functional calculations carried out on large supercells show that the contact of Au with TiC(001) is essential for charge polarization and an enhancement in the chemical activity of Au. Small two-dimensional particles which expose Au atoms in contact with TiC(001) are the most reactive. While O{sub 2} prefers binding to Au sites, the O atoms interact more strongly with the TiC(001) surface. The oxygen species active during the low-temperature (<200 K) oxidation of carbon monoxide on Au/TiC(001) is chemisorbed O{sub 2}. Once atomic O binds to TiC(001), the chemisorption bond is so strong that temperatures well above 400 K are necessary to remove the O adatoms from the TiC(001) substrate by direct reaction with CO. The high reactivity of Au/TiC(001) toward O{sub 2} at low-temperature opens the route for the transformation of alcohols and amines on the supported Au nanoparticles.« less

  2. Role of Au-C Interactions on the Catalytic Activity of Au Nanoparticles Supported on TiC(001) toward Molecular Oxygen Dissociation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rodriguez, J.; Feria, L; Jirsak, T

    2010-01-01

    High-resolution photoemission and density functional calculations on realistic slab surface models were used to study the interaction and subsequent dissociation of O{sub 2} with Au nanoparticles supported on TiC(001). The photoemission results indicate that at 150 K O{sub 2} adsorbs molecularly on the supported gold nanoparticles, and upon heating to temperatures above 200 K the O{sub 2} {yields} 2O reaction takes place with migration of atomic oxygen to the TiC(001) substrate. The addition of Au to TiC(001) substantially enhances the rate of O{sub 2} dissociation at room temperature. The reactivity of Au nanoparticles supported on TiC(001) toward O{sub 2} dissociationmore » is much larger than that of similar nanoparticles supported either on TiO{sub 2}(110) or MgO(001) surfaces, where the cleavage of O-O bonds is very difficult. Density functional calculations carried out on large supercells show that the contact of Au with TiC(001) is essential for charge polarization and an enhancement in the chemical activity of Au. Small two-dimensional particles which expose Au atoms in contact with TiC(001) are the most reactive. While O{sub 2} prefers binding to Au sites, the O atoms interact more strongly with the TiC(001) surface. The oxygen species active during the low-temperature (<200 K) oxidation of carbon monoxide on Au/TiC(001) is chemisorbed O{sub 2}. Once atomic O binds to TiC(001), the chemisorption bond is so strong that temperatures well above 400 K are necessary to remove the O adatoms from the TiC(001) substrate by direct reaction with CO. The high reactivity of Au/TiC(001) toward O{sub 2} at low-temperature opens the route for the transformation of alcohols and amines on the supported Au nanoparticles.« less

  3. Highly sensitive aptasensor based on synergetic catalysis activity of MoS2-Au-HE composite using cDNA-Au-GOD for signal amplification.

    PubMed

    Song, Hai-Yan; Kang, Tian-Fang; Lu, Li-Ping; Cheng, Shui-Yuan

    2017-03-01

    Single or few-layer nanosheets of MoS 2 (MoS 2 nanosheets) and a composite composed of MoS 2 nanosheets, Au nanoparticles (AuNPs) and hemin (HE) (denoted as MoS 2 -Au-HE) were prepared. The composites possessed high synergetic catalysis activity towards the electroreduction of hydrogen peroxide. Furthermore, glucose oxidase (GOD) and AuNPs were used as marker of the complementary DNA (cDNA) strand of kanamycin aptamer to prepare a conjugate (reffered as cDNA-Au-GOD) that was designed as the signal probe. Both cDNA-Au-GOD and MoS 2 -Au-HE were applied to fabricate aptasensor for kanamycin. MoS 2 -Au-HE acted as solid platform for kanamycin aptamer and signal transmitters. AuNPs were employed as the supporter of cDNA and GOD which catalyze dissolved oxygen to produce hydrogen peroxide in the presence of glucose. Then cathodic peak current of H 2 O 2 was recorded by differential pulse voltammetry (DPV). The electrochemical reduction of H 2 O 2 was catalyzed by MoS 2 -Au-HE that was modified onto the surface of a glassy carbon electrode (GCE). The cathodic peak current of H 2 O 2 was highly linearly decreased with an increase of kanamycin concentrations from 1.0ng/L to 1.0×10 5 ng/L, with a detection limit of 0.8ng/L. This aptasensor can be used to detect kanamycin in milk with high specificity, sensitivity and selectivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Buoyancy-assisted mixed convective flow over backward-facing step in a vertical duct using nanofluids

    NASA Astrophysics Data System (ADS)

    Mohammed, H. A.; Al-aswadi, A. A.; Yusoff, M. Z.; Saidur, R.

    2012-03-01

    Laminar mixed convective buoyancy assisting flow through a two-dimensional vertical duct with a backward-facing step using nanofluids as a medium is numerically simulated using finite volume technique. Different types of nanoparticles such as Au, Ag, Al2O3, Cu, CuO, diamond, SiO2 and TiO2 with 5 % volume fraction are used. The wall downstream of the step was maintained at a uniform wall temperature, while the straight wall that forms the other side of the duct was maintained at constant temperature equivalent to the inlet fluid temperature. The walls upstream of the step and the backward-facing step were considered as adiabatic surfaces. The duct has a step height of 4.9 mm and an expansion ratio of 1.942, while the total length in the downstream of the step is 0.5 m. The downstream wall was fixed at uniform wall temperature 0 ≤ Δ T≤ 30 °C, which was higher than the inlet flow temperature. The Reynolds number in the range of 75 ≤ Re ≤ 225 was considered. It is found that a recirculation region was developed straight behind the backward-facing step which appeared between the edge of the step and few millimeters before the corner which connect the step and the downstream wall. In the few millimeters gap between the recirculation region and the downstream wall, a U-turn flow was developed opposite to the recirculation flow which mixed with the unrecirculated flow and traveled along the channel. Two maximum and one minimum peaks in Nusselt number were developed along the heated downstream wall. It is inferred that Au nanofluid has the highest maximum peaks while diamond nanofluid has the highest minimum peak. Nanofluids with a higher Prandtl number have a higher peak of Nusselt numbers after the separation and the recirculation flow disappeared.

  5. Synthesis and characterization of Au incorporated Alq3 nanowires

    NASA Astrophysics Data System (ADS)

    Khan, Mohammad Bilal; Ahmad, Sultan; Parwaz, M.; Rahul, Khan, Zishan H.

    2018-05-01

    We report the synthesis and characterization of pure and Au incorporated Alq3 nanowires. These nanowires are synthesized using thermal vapor transport method. The luminescence intensity of Au incorporated Alq3 nanowires are recorded to be higher than that of pure Alq3 nanowires, which is found to increase with the increase in Au concentration. Fluorescence quenching is also observed when Au concentration is increased beyond the certain limit.

  6. Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV.

    PubMed

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Baumgart, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Betts, R R; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bombara, M; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Callner, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chung, S U; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; Dephillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Feng, A; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Garcia-Solis, E; Ghazikhanian, V; Ghosh, P; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Gupta, N; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Heppelmann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Hofman, D; Hollis, R; Horner, M J; Huang, H Z; Hughes, E W; Humanic, T J; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Kettler, D; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kurnadi, P; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lapointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mitchell, J; Mohanty, B; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Nepali, N S; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Planinic, M; Pluta, J; Poljak, N; Porile, N; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Qattan, I A; Raniwala, R; Raniwala, S; Ray, R L; Relyea, D; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Staszak, D; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Z; Surrow, B; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van der Kolk, N; van Leeuwen, M; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, J; Wu, Y; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yue, Q; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zhou, J; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2007-05-11

    The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.

  7. Framing faces: Frame alignment impacts holistic face perception.

    PubMed

    Curby, Kim M; Entenman, Robert

    2016-11-01

    Traditional accounts of face perception emphasise the importance of the prototypical configuration of features within faces. However, here we probe influences of more general perceptual grouping mechanisms on holistic face perception. Participants made part-matching judgments about composite faces presented in intact external oval frames or frames made from misaligned oval parts. This manipulation served to disrupt basic perceptual grouping cues that facilitate the grouping of the two face halves together. This manipulation also produced an external face contour like that in the standard misaligned condition used within the classic composite face task. Notably, by introducing a discontinuity in the external contour, grouping of the face halves into a cohesive unit was discouraged, but face configuration was preserved. Conditions where both the face parts and the frames were misaligned together, as in the typical composite task paradigm, or where just the internal face parts where misaligned, were also included. Disrupting only the face frame similarly disrupted holistic face perception as disrupting both the frame and face configuration. However, misaligned face parts presented in aligned frames also incurred a cost to holistic perception. These findings provide support for the contribution of general-purpose perceptual grouping mechanisms to holistic face perception and are presented and discussed in the context of an enhanced object-based selection account of holistic perception.

  8. Microstructure and opto-electronic properties of Sn-rich Au-Sn diffusive solders

    NASA Astrophysics Data System (ADS)

    Rerek, T.; Skowronski, L.; Kobierski, M.; Naparty, M. K.; Derkowska-Zielinska, B.

    2018-09-01

    Microstructural and opto-electronic properties of Au ⧹ Sn and Sn ⧹ Au bilayers, obtained by sequential evaporating of metals on the Si substrate, were investigated by means of atomic force microscopy, X-ray diffraction and spectroscopic ellipsometry. Thicknesses of individual films were established to obtain the atomic ratio of Au:Sn atoms 1:1, 1:2 and 1:4, which were favor the formation of AuSn, AuSn2 and AuSn4, respectively. However, the produced intermatallic compounds were detected as AuSn and AuSn2. Additionally, the unbounded Sn was found. The sequence of deposition of Au and Sn films as well as their thickness strongly affect on the composition, microstructure, optical and electrical properties of the produced layers. The Au ⧹ Sn (Sn on the top) layers were more smooth than Sn ⧹ Au (Au on the top) films. Generally, the Au ⧹ Sn layers exhibit a better electrical and optical properties than Sn ⧹ Au films. The optical parameters: plasma energy, free-carrier damping, mean relaxation time of conduction electrons and optical resistivity were determined from the effective complex dielectric function of the formed Au, Sn and Au-Sn films. The optical resistivity values are in the range from 17.8 μΩ cm to 85.1 μΩ cm and from 29.6 μΩ cm to 113.3 μΩ cm for Au ⧹ Sn and Sn ⧹ Au layers, respectively.

  9. UV and visible light photocatalytic activity of Au/TiO2 nanoforests with Anatase/Rutile phase junctions and controlled Au locations.

    PubMed

    Yu, Yang; Wen, Wei; Qian, Xin-Yue; Liu, Jia-Bin; Wu, Jin-Ming

    2017-01-24

    To magnify anatase/rutile phase junction effects through appropriate Au decorations, a facile solution-based approach was developed to synthesize Au/TiO 2 nanoforests with controlled Au locations. The nanoforests cons®isted of anatase nanowires surrounded by radially grown rutile branches, on which Au nanoparticles were deposited with preferred locations controlled by simply altering the order of the fabrication step. The Au-decoration increased the photocatalytic activity under the illumination of either UV or visible light, because of the beneficial effects of either electron trapping or localized surface plasmon resonance (LSPR). Gold nanoparticles located preferably at the interface of anatase/rutile led to a further enhanced photocatalytic activity. The appropriate distributions of Au nanoparticles magnify the beneficial effects arising from the anatase/rutile phase junctions when illuminated by UV light. Under the visible light illumination, the LSPR effect followed by the consecutive electron transfer explains the enhanced photocatalysis. This study provides a facile route to control locations of gold nanoparticles in one-dimensional nanostructured arrays of multiple-phases semiconductors for achieving a further increased photocatalytic activity.

  10. The Influence of Interstitial Ga and Interfacial Au (sub 2)P (sub 3) on the Electrical and Metallurgical Behavior of Au-Contacted III-V Semiconductors

    NASA Technical Reports Server (NTRS)

    Weizer, Victor G.; Fatemi, Navid S.

    1991-01-01

    The introduction of a very small amount of Ga into Au contact metallization on InP is shown to have a significant effect on both the metallurgical and electrical behavior of that contact system. Ga atoms in the interstices of the Au lattice are shown to be effective in preventing the solid state reactions that normally take place between Au and InP during contact sintering. In addition to suppressing the metallurgical interaction, the presence of small amounts of Ga is shown to cause an order of magnitude reduction in the specific contact resistivity. Evidence is presented that the reactions of GaP and GaAs with Au contacts are also drastically affected by the presence of Ga. The sintering behavior of the Au-GaP and the Au-GaAs systems (as contrasted with that of the Au-InP system) is explained as due to the presence of interstitial Ga in the contact metallization. Finally the large, two-to-three order of magnitude drop in the contact resistance that occurs in the Au-InP system upon sintering at 400 degrees Centigrade is shown to be a result of the formation of an Au (sub 2) P (sub 3) layer at the metal-semiconductor interface. Contact resistivities in the 10 (sup -6) ohm square centimeter range are obtained for as-deposited Au on InP when a thin (20 Angstrom) layer of Au (sub 2) P (sub 3) is introduced between the InP and the Au contacts.

  11. Identifying Au-based Te alloys for optical data storage

    NASA Astrophysics Data System (ADS)

    Wamwangi, D.; Detemple, R.; Woeltgens, H.-W.; Wuttig, M.; Zhang, X.

    2004-06-01

    Au18Sb23Te59 and Au19In26Te55 have been investigated to determine their suitability as phase change recording alloys. Recrystallization experiments identify Au18Sb23Te59 as a suitable phase change material with a recrystallization time of 110 ns and high optical contrast. Coupled to the high optical contrast is a considerable density increase of 4% upon crystallization which allows phase change recording for the Au18Sb23Te59 alloy. On the other hand no recrystallization has been observed optically for Au19In26Te55 due to its low optical contrast of less than 1%. This is related to a lower density contrast of 2%. The crystallization for the Au18Sb23Te59 and Au19In26Te55 alloys observed from temperature-dependent sheet resistance measurements have yielded transition temperatures of 113 and 175 °C, and activation barriers of 1.61±0.01 eV and 2.42±0.02 eV, respectively. We report a cubic structure (a=2.99±0.002 Å) for the Au18Sb23Te59 alloy and a chalcopyrite structure (a=6.50±0.018 Å and 12.27±0.025 Å) for the Au19In26Te55 material. These results confirm that suitable phase change alloys possess cubic structures rather than the chalcopyrite structure typical for sp3 bonded semiconductors.

  12. Identification of Au–S complexes on Au(100)

    DOE PAGES

    Walen, Holly; Liu, Da -Jiang; Oh, Junepyo; ...

    2016-01-25

    In this study, using a combination of scanning tunneling microscopy and density functional theory (DFT) calculations, we have identified a set of related Au–S complexes that form on Au(100), when sulfur adsorbs and lifts the hexagonal surface reconstruction. The predominant complex is diamond-shaped with stoichiometry Au 4S 5. All of the complexes can be regarded as combinations of S–Au–S subunits. The complexes exist within, or at the edges of, p(2 × 2) sulfur islands that cover the unreconstructed Au regions, and are observed throughout the range of S coverage examined in this study, 0.009 to 0.12 monolayers. A qualitative modelmore » is developed which incorporates competitive formation of complexes, Au rafts, and p(2 × 2) sulfur islands, as Au atoms are released by the surface structure transformation.« less

  13. A comparative study of the electrostatic potential of fullerene-like structures of Au 32 and Au 42

    NASA Astrophysics Data System (ADS)

    Wang, Dong-Lai; Sun, Xiao-Ping; Shen, Hong-Tao; Hou, Dong-Yan; Zhai, Yu-Chun

    2008-05-01

    By using density functional theory calculations, it is found that the most negative MEP inside the gold cage occurs at the center of the sphere. The largest regions with the most negative MEP outside the sphere are localized in the neighborhood of the bridge sites and the vertex regions of the five-coordinated are more positive. The absolute values of the most negative potentials in both the inner and outer cages as well as the vertex regions of the five-coordinated of Au 32 structure are much larger than those of Au 42, which means Au 32 is preferable for electrophilic attack or nucleophilic processes.

  14. Au/NiFe/M(Au, MoS2, graphene) trilayer magnetoplasmonics DNA-hybridized sensors with high record of sensitivity

    NASA Astrophysics Data System (ADS)

    Faridi, Ehsan; Moradi, Maryam; Ansari, Narges; Ghasemi, Amir Hossein Baradaran; Afshar, Amir; Mohseni, Seyed Majid

    2017-12-01

    The demonstration of biosensors based on the surface plasmon effect holds promise for future high-sensitive electrodeless biodetection. The combination of magnetic effects with surface plasmon waves brings additional freedom to improve sensitivity and signal selectivity. Stacking biosensors with two-dimensional (2-D) materials, e.g., graphene (Gr) and MoS2, can influence plasmon waves and facilitate surface physiochemical properties as additional versatility aspects. We demonstrate magnetoplasmonic biosensors through the detuning of surface plasmon oscillation modes affected by magnetic effect via the presence of the NiFe (Py) layer and different light absorbers of Gr, MoS2, and Au ultrathin layers in three stacks of Au/Py/M(MoS2, Gr, Au) trilayers. We found minimum reflection, resonance angle shift, and transverse magneto-optical Kerr effect (TMOKE) responses of all sensors in the presence of the ss-DNA monolayer. Very few changes of ˜5×10-7 in the ss-DNA's refractive index result in valuable TMOKE response. We found that the presence of three-layer Gr and two-layer MoS2 on top of the Au/Py bilayer can dramatically increase the sensitivity by nine and four times, respectively, than the conventional Au/Co/Au trilayer. Our results show the highest reported DNA sensitivity based on the coupling of light with 2-D materials in magnetoplasmonic devices.

  15. Size-induced chemical and magnetic ordering in individual Fe-Au nanoparticles.

    PubMed

    Mukherjee, Pinaki; Manchanda, Priyanka; Kumar, Pankaj; Zhou, Lin; Kramer, Matthew J; Kashyap, Arti; Skomski, Ralph; Sellmyer, David; Shield, Jeffrey E

    2014-08-26

    Formation of chemically ordered compounds of Fe and Au is inhibited in bulk materials due to their limited mutual solubility. However, here we report the formation of chemically ordered L12-type Fe3Au and FeAu3 compounds in Fe-Au sub-10 nm nanoparticles, suggesting that they are equilibrium structures in size-constrained systems. The stability of these L12-ordered Fe3Au and FeAu3 compounds along with a previously discovered L10-ordered FeAu has been explained by a size-dependent equilibrium thermodynamic model. Furthermore, the spin ordering of these three compounds has been computed using ab initio first-principle calculations. All ordered compounds exhibit a substantial magnetization at room temperature. The Fe3Au had a high saturation magnetization of about 143.6 emu/g with a ferromagnetic spin structure. The FeAu3 nanoparticles displayed a low saturation magnetization of about 11 emu/g. This suggests a antiferromagnetic spin structure, with the net magnetization arising from uncompensated surface spins. First-principle calculations using the Vienna ab initio simulation package (VASP) indicate that ferromagnetic ordering is energetically most stable in Fe3Au, while antiferromagnetic order is predicted in FeAu and FeAu3, consistent with the experimental results.

  16. Non Photonic e-D{sup 0} correlations in p+p and Au+Au collisions at {radical}(S{sub NN} = 200 GeV)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Geromitsos, Artemios

    The sum of charm and beauty in Au+Au collisions at 200 GeV measured through non-photonic electrons, show similar suppression at high p{sub T} as light hadrons, in contrast to expectations based on the dead cone effect. To understand this observation, it is important to separate the charm and beauty components. Non-photonic electron-D{sup 0} and electron-hadron azimuthal angular correlations are used to disentangle the contributions from charm and beauty decays. The beauty contribution in p+p. collisions at 200 GeV is found to be comparable to charm at p{sub T}{approx}5.5 GeV, indicating that beauty may contribute significantly to the non photonic electronsmore » from heavy flavour decays in Au+Au data at high p{sub T}. Furthermore, we are employing microvertexing techniques, not used for the analysis of p+p collisions, in Au+Au collisions at 200 GeV. We present our analysis status of D{sub 0} meson reconstruction.« less

  17. Charged particle multiplicity fluctuations in Au+Au collisions at \\sqrt{s_{NN}} = 200\\, {\\rm GeV}

    NASA Astrophysics Data System (ADS)

    Wozniak, Krzysztof; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J. L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wuosmaa, A. H.; Wyslouch, B.

    2004-08-01

    This paper presents the first PHOBOS results on charged particle multiplicity fluctuations measured for Au+Au collisions at the highest RHIC energy within a wide pseudorapidity range of |eegr| < 3. The dependence on collision geometry is removed in the analysis by using the normalized difference between the number of particles in separate eegr bins. We compare our data to HIJING model predictions.

  18. A general and high-yield galvanic displacement approach to Au-M (M = Au, Pd, and Pt) core-shell nanostructures with porous shells and enhanced electrocatalytic performances.

    PubMed

    Kuai, Long; Geng, Baoyou; Wang, Shaozhen; Sang, Yan

    2012-07-23

    In this work, we utilize the galvanic displacement synthesis and make it a general and efficient method for the preparation of Au-M (M = Au, Pd, and Pt) core-shell nanostructures with porous shells, which consist of multilayer nanoparticles. The method is generally applicable to the preparation of Au-Au, Au-Pd, and Au-Pt core-shell nanostructures with typical porous shells. Moreover, the Au-Au isomeric core-shell nanostructure is reported for the first time. The lower oxidation states of Au(I), Pd(II), and Pt(II) are supposed to contribute to the formation of porous core-shell nanostructures instead of yolk-shell nanostructures. The electrocatalytic ethanol oxidation and oxygen reduction reaction (ORR) performance of porous Au-Pd core-shell nanostructures are assessed as a typical example for the investigation of the advantages of the obtained core-shell nanostructures. As expected, the Au-Pd core-shell nanostructure indeed exhibits a significantly reduced overpotential (the peak potential is shifted in the positive direction by 44 mV and 32 mV), a much improved CO tolerance (I(f)/I(b) is 3.6 and 1.63 times higher), and an enhanced catalytic stability in comparison with Pd nanoparticles and Pt/C catalysts. Thus, porous Au-M (M = Au, Pd, and Pt) core-shell nanostructures may provide many opportunities in the fields of organic catalysis, direct alcohol fuel cells, surface-enhanced Raman scattering, and so forth. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. How Well Do Computer-Generated Faces Tap Face Expertise?

    PubMed

    Crookes, Kate; Ewing, Louise; Gildenhuys, Ju-Dith; Kloth, Nadine; Hayward, William G; Oxner, Matt; Pond, Stephen; Rhodes, Gillian

    2015-01-01

    The use of computer-generated (CG) stimuli in face processing research is proliferating due to the ease with which faces can be generated, standardised and manipulated. However there has been surprisingly little research into whether CG faces are processed in the same way as photographs of real faces. The present study assessed how well CG faces tap face identity expertise by investigating whether two indicators of face expertise are reduced for CG faces when compared to face photographs. These indicators were accuracy for identification of own-race faces and the other-race effect (ORE)-the well-established finding that own-race faces are recognised more accurately than other-race faces. In Experiment 1 Caucasian and Asian participants completed a recognition memory task for own- and other-race real and CG faces. Overall accuracy for own-race faces was dramatically reduced for CG compared to real faces and the ORE was significantly and substantially attenuated for CG faces. Experiment 2 investigated perceptual discrimination for own- and other-race real and CG faces with Caucasian and Asian participants. Here again, accuracy for own-race faces was significantly reduced for CG compared to real faces. However the ORE was not affected by format. Together these results signal that CG faces of the type tested here do not fully tap face expertise. Technological advancement may, in the future, produce CG faces that are equivalent to real photographs. Until then caution is advised when interpreting results obtained using CG faces.

  20. ϕ Meson Spin Alignment and the Azimuthal Angle Dependence of Λ (Λ) Polarization in Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Tu, Biao

    2018-02-01

    Initial large global angular momentum in non-central relativistic heavy-ion collisions can produce strong vorticity, and through the spin-orbit coupling, causes the spin of particles to align with the system's global angular momentum. We present the azimuthal angle dependent (relative to the reaction plane) polarization for Λ and Λ in mid-central Au+Au collisions at = 200 GeV. We also present the ϕ meson spin alignment parameter, ρ00 in Au+Au collisions at = 19.6, 27, 39, 62.4 and 200 GeV. The implications of the results are discussed.

  1. Forward-backward multiplicity correlations in sNN=200 GeV Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Noucier, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G. J. Van; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2006-07-01

    Forward-backward correlations of charged-particle multiplicities in symmetric bins in pseudorapidity are studied to gain insight into the underlying correlation structure of particle production in Au+Au collisions. The PHOBOS detector is used to measure integrated multiplicities in bins centered at η, defined within |η|<3, and covering intervals Δη. The variance σC2 of a suitably defined forward-backward asymmetry variable C is calculated as a function of η,Δη, and centrality. It is found to be sensitive to short-range correlations, and the concept of “clustering” is used to interpret comparisons to phenomenological models.

  2. Exploring the Photoreduction of Au(III) Complexes in the Gas-Phase

    NASA Astrophysics Data System (ADS)

    Marcum, Jesse C.; Kaufman, Sydney H.; Weber, J. Mathias

    2010-06-01

    We have used photodissociation spectroscopy to probe the electronic structure and photoreduction of Au(III) in gas-phase complexes containing Cl- and OH-. The gas-phase electronic spectrum of [AuCl_4]- closely resembles the aqueous solution spectrum, showing a lack of strong solvatochromic shifts. Substitution of Cl- ligands with OH- results in a strong blue shift, in agreement with ligand-field theory. Upon excitation, [AuCl_4]- can dissociate by loss of either one or two neutral Cl atoms, resulting in the reduction of gold from Au(III) to Au(II) and Au(I) respectively. The hydroxide substituted complex, [AuCl_2(OH)_2]-, demonstrates similar behavior but the only observable fragment channel is the loss of two neutral OH ligands, leading only to Au(I).

  3. Nucleon shadowing effects in Cu + Cu and Au + Au collisions at RHIC within the HIJING code

    NASA Astrophysics Data System (ADS)

    Abdel-Waged, Khaled; Felemban, Nuha

    2018-02-01

    The centrality dependence of pseudorapidity density of charged particles ({{{d}}{N}}{{ch}}/{{d}}η ) in Cu + Cu (Au + Au) collisions at Relativistic Heavy Ion Collider energy of \\sqrt{{s}{{NN}}}=22.4, 62.4 and 200 (19.6, 62.4 and 200) GeV, is investigated within an improved HIJING code. The standard HIJING model is enhanced by a prescription for collective nucleon-nucleon (NN) interactions and more modern parton distribution functions. The collective NN-interactions are used to induce both cascade and nucleon shadowing effects. We find collective cascade broadens the pseudorapidity distributions in the tails (at | η | > {y}{beam}) above 25%-30% collision centrality to be consistent with the {{{d}}{N}}{{ch}}/{{d}}η data at \\sqrt{{s}{{NN}}} =19.6,22.4,62.4 {GeV}. The overall contribution of nucleon shadowing is shown to depress the whole shape of {{{d}}{N}}{{ch}}/{{d}}η in the primary interaction region (at | η | < {y}{beam}) for semiperipheral (20%-25%) and peripheral (≥slant 35 % {--}40 % ) Cu + Cu (Au + Au) interactions at \\sqrt{{s}{{NN}}}=200 {GeV}, in accordance with the PHOBOS data.

  4. Efficacy of the thin agar layer method for the recovery of stressed Cronobacter spp. (Enterobacter sakazakii).

    PubMed

    Osaili, Tareq M; Al-Nabulsi, Anas A; Shaker, Reyad R; Al-Holy, Murad M; Al-Haddaq, Mohammed S; Olaimat, Amin N; Ayyash, Mutamed M; Al Ta'ani, Mahmoud K; Forsythe, Stephen J

    2010-10-01

    Cronobacter spp. (Enterobacter sakazakii) are emerging opportunistic pathogens for all age groups, and are of particular concern when it comes to infants. Prior to contaminating food, the organism may be exposed to a variety of stresses, leading to a generation of sublethally injured cells that may not be detected by selective media unless a protracted recovery period is included in the isolation procedure. This study evaluated the efficacy of the thin agar layer (TAL) method for the recovery of Cronobacter cells that had been exposed to various stress conditions. Five strains of C. sakazakii and C. muytjensii were exposed to starvation, heat, cold, acid, alkaline, chlorine, or ethanol, with or without further exposure to desiccation stress. The recovery of the stressed cells was determined on tryptone soy agar (TSA; nonselective control medium), violet red bile glucose agar (VRBGA; selective agar), Druggan-Forsythe-Iversen (DFI; selective agar), and TAL media (viz., VRBGA overlaid with TSA, and DFI overlaid with TSA). Regardless of stress type, there were no significant differences among the recoveries of stressed desiccated Cronobacter spp. cultures on TSA, DFI+TSA, and VRBGA+TSA, but there was significantly less recovery on VRBGA. The recovery of prestressed desiccated Cronobacter spp. on DFI+TSA was similar to that on TSA, whereas the recovery on VRBGA+TSA was lower. DFI+TSA performed better than VRBGA+TSA did in differentiating Cronobacter spp. within mixed bacterial cultures. The results of this study suggest the use of the TAL method DFI+TSA as an improved method for the direct recovery of stressed Cronobacter spp.

  5. Dual structural transition in small nanoparticles of Cu-Au alloy

    NASA Astrophysics Data System (ADS)

    Gafner, Yuri; Gafner, Svetlana; Redel, Larisa; Zamulin, Ivan

    2018-02-01

    Cu-Au alloy nanoparticles are known to be widely used in the catalysis of various chemical reactions as it was experimentally defined that in many cases the partial substitution of copper with gold increases catalytic activity. However, providing the reaction capacity of alloy nanoparticles the surface electronic structure strongly depends on their atomic ordering. Therefore, to theoretically determine catalytic properties, one needs to use a most real structural model complying with Cu-Au nanoparticles under various external influences. So, thermal stability limits were studied for the initial L12 phase in Cu3Au nanoalloy clusters up to 8.0 nm and Cu-Au clusters up to 3.0 nm at various degrees of Au atom concentration, with molecular dynamics method using a modified tight-binding TB-SMA potential. Dual structural transition L12 → FCC and further FCC → Ih is shown to be possible under the thermal factor in Cu3Au and Cu-Au clusters with the diameter up to 3.0 nm. The temperature of the structural transition FCC → Ih is established to decrease for small particles of Cu-Au alloy under the increase of Au atom concentration. For clusters with this structural transition, the melting point is found to be a linear increasing function of concentration, and for clusters without FCC → Ih structural transition, the melting point is a linear decreasing function of Au content. Thus, the article shows that doping Cu nanoclusters with Au atoms allows to control the forming structure as well as the melting point.

  6. A Thermally Stable NiZn/Ta/Ni Scheme to Replace AuBe/Au Contacts in High-Efficiency AlGaInP-Based Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Hyun; Park, Jae-Seong; Kang, Daesung; Seong, Tae-Yeon

    2017-08-01

    We developed NiZn/(Ta/)Ni ohmic contacts to replace expensive AuBe/Au contacts commonly used in high-efficiency AlGaInP-based light-emitting diodes (LEDs), and compared the electrical properties of the two contact types. Unlike the AuBe/Au (130 nm/100 nm) contact, the NiZn/Ta/Ni (130 nm/20 nm/100 nm) contact shows improved electrical properties after being annealed at 500°C, with a contact resistivity of 5.2 × 10-6 Ω cm2. LEDs with the NiZn/Ta/Ni contact exhibited a 4.4% higher output power (at 250 mW) than LEDs with the AuBe/Au contact. In contrast to the trend for the AuBe/Au contact, the Ga 2 p core level for the NiZn/Ta/Ni contact shifted toward lower binding energies after being annealed at 500°C. Auger electron spectroscopy (AES) depth profiles showed that annealing the AuBe/Au samples caused the outdiffusion of both Be and P atoms into the metal contact, whereas in the NiZn/Ta/Ni samples, Zn atoms indiffused into the GaP layer. The annealing-induced electrical degradation and ohmic contact formation mechanisms are described and discussed on the basis of the results of x-ray photoemission spectroscopy and AES.

  7. Ratio of shear viscosity to entropy density in multifragmentation of Au + Au

    NASA Astrophysics Data System (ADS)

    Zhou, C. L.; Ma, Y. G.; Fang, D. Q.; Li, S. X.; Zhang, G. Q.

    2012-06-01

    The ratio of the shear viscosity (η) to entropy density (s) for the intermediate energy heavy-ion collisions has been calculated by using the Green-Kubo method in the framework of the quantum molecular dynamics model. The theoretical curve of η/s as a function of the incident energy for the head-on Au + Au collisions displays that a minimum region of η/s has been approached at higher incident energies, where the minimum η/s value is about 7 times Kovtun-Son-Starinets (KSS) bound (1/4π). We argue that the onset of minimum η/s region at higher incident energies corresponds to the nuclear liquid gas phase transition in nuclear multifragmentation.

  8. Surface effects on the radiation response of nanoporous Au foams

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fu, E. G.; Caro, M.; Wang, Y. Q.

    2012-11-05

    We report on an experimental and simulation campaign aimed at exploring the radiation response of nanoporous Au (np-Au) foams. We find different defect accumulation behavior by varying radiation dose-rate in ion-irradiated np-Au foams. Stacking fault tetrahedra are formed when np-Au foams are irradiated at high dose-rate, but they do not seem to be formed in np-Au at low dose-rate irradiation. A model is proposed to explain the dose-rate dependent defect accumulation based on these results.

  9. Simultaneous AuIII Extraction and In Situ Formation of Polymeric Membrane-Supported Au Nanoparticles: A Sustainable Process with Application in Catalysis.

    PubMed

    Mora-Tamez, Lucía; Esquivel-Peña, Vicente; Ocampo, Ana L; Rodríguez de San Miguel, Eduardo; Grande, Daniel; de Gyves, Josefina

    2017-04-10

    A polymeric membrane-supported catalyst with immobilized gold nanoparticles (AuNPs) was prepared through the extraction and in situ reduction of Au III salts in a one-step strategy. Polymeric inclusion membranes (PIMs) and polymeric nanoporous membranes (PNMs) were tested as different membrane-support systems. Transport experiments indicated that PIMs composed of cellulose triacetate, 2-nitrophenyloctyl ether, and an aliphatic tertiary amine (Adogen 364 or Alamine 336) were the most efficient supports for Au III extraction. The simultaneous extraction and reduction processes were proven to be the result of a synergic phenomenon in which all the membrane components were involved. Scanning electron microscopy characterization of cross-sectional samples suggested a distribution of AuNPs throughout the membrane. Transmission electron microscopy characterization of the AuNPs indicated average particle sizes of 36.7 and 2.9 nm for the PIMs and PNMs, respectively. AuNPs supported on PIMs allowed for >95.4 % reduction of a 0.05 mmol L -1 4-nitrophenol aqueous solution with 10 mmol L -1 NaBH 4 solution within 25 min. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Flight set 360L003 instrumentation final test report, volume 9

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Post-flight instrumentation hardware and data evaluation for 360L003 is summarized. The 360L003 motors were equipped with Developmental Flight Instrumentation (DFI), Operational Flight Instrumentation (OFI), and Ground Environmental Instrumentation (GEI). The DFI was designed to measure strain, temperature, pressure, and vibration at various locations on the motor during flight. The DFI is used to validate engineering models in a flight environment. The OFI consists of six Operational Pressure Tranducers which monitor chamber pressure during flight. These pressure transducers are used in the SRB separation cue. GEI measures the motor case, igniter flange, and nozzle temperature prior to launch.

  11. The diagnostic and clinical significance of café-au-lait macules.

    PubMed

    Shah, Kara N

    2010-10-01

    Café-au-lait, also referred to as café-au-lait spots or café-au-lait macules, present as well-circumscribed, evenly pigmented macules and patches that range in size from 1 to 2 mm to greater than 20 cm in greatest diameter. Café-au-lait are common in children. Although most café-au-lait present as 1 or 2 spots in an otherwise healthy child, the presence of multiple café-au-lait, large segmental café-au-lait, associated facial dysmorphism, other cutaneous anomalies, or unusual findings on physical examination should suggest the possibility of an associated syndrome. While neurofibromatosis type 1 is the most common syndrome seen in children with multiple café-au-lait, other syndromes associated with one or more café-au-lait include McCune-Albright syndrome, Legius syndrome, Noonan syndrome and other neuro-cardio-facialcutaneous syndromes, ring chromosome syndromes, and constitutional mismatch repair deficiency syndrome. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Noncentrosymmetric superconductor BeAu

    NASA Astrophysics Data System (ADS)

    Amon, A.; Svanidze, E.; Cardoso-Gil, R.; Wilson, M. N.; Rosner, H.; Bobnar, M.; Schnelle, W.; Lynn, J. W.; Gumeniuk, R.; Hennig, C.; Luke, G. M.; Borrmann, H.; Leithe-Jasper, A.; Grin, Yu.

    2018-01-01

    Mixed spin-singlet and spin-triplet pairing can occur in noncentrosymmetric superconductors. In this respect, a comprehensive characterization of the noncentrosymmetric superconductor BeAu was carried out. It was established that BeAu undergoes a structural phase transition from a low-temperature noncentrosymmetric FeSi structure type to a high-temperature centrosymmetric structure in the CsCl type at Ts=860 K. The low-temperature modification exhibits a superconducting transition below Tc=3.3 K. The values of lower (Hc1=32 Oe) and upper (Hc2=335 Oe) critical fields are rather small, confirming that this type-II (κG-L=2.3 ) weakly coupled (λe-p=0.5 ,Δ Ce/γnTc≈1.26 ) superconductor can be well understood within the Bardeen-Cooper-Schrieffer theory. The muon spin relaxation analysis indicates that the time-reversal symmetry is preserved when the superconducting state is entered, supporting conventional superconductivity in BeAu. From the density functional band structure calculations, a considerable contribution of the Be electrons to the superconducting state was established. On average, a rather small mass renormalization was found, consistent with the experimental data.

  13. Au/NiFe/M(Au, MoS2, graphene) trilayer magnetoplasmonics DNA-hybridized sensors with high record of sensitivity.

    PubMed

    Faridi, Ehsan; Moradi, Maryam; Ansari, Narges; Baradaran Ghasemi, Amir Hossein; Afshar, Amir; Mohseni Armaki, Seyed Majid

    2017-12-01

    The demonstration of biosensors based on the surface plasmon effect holds promise for future high-sensitive electrodeless biodetection. The combination of magnetic effects with surface plasmon waves brings additional freedom to improve sensitivity and signal selectivity. Stacking biosensors with two-dimensional (2-D) materials, e.g., graphene (Gr) and MoS2, can influence plasmon waves and facilitate surface physiochemical properties as additional versatility aspects. We demonstrate magnetoplasmonic biosensors through the detuning of surface plasmon oscillation modes affected by magnetic effect via the presence of the NiFe (Py) layer and different light absorbers of Gr, MoS2, and Au ultrathin layers in three stacks of Au/Py/M(MoS2, Gr, Au) trilayers. We found minimum reflection, resonance angle shift, and transverse magneto-optical Kerr effect (TMOKE) responses of all sensors in the presence of the ss-DNA monolayer. Very few changes of ∼5×10-7 in the ss-DNA's refractive index result in valuable TMOKE response. We found that the presence of three-layer Gr and two-layer MoS2 on top of the Au/Py bilayer can dramatically increase the sensitivity by nine and four times, respectively, than the conventional Au/Co/Au trilayer. Our results show the highest reported DNA sensitivity based on the coupling of light with 2-D materials in magnetoplasmonic devices. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  14. Partonic Flow and phi-Meson production in Au+Au collisions at sqrt radical sNN = 200 GeV.

    PubMed

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Baumgart, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Betts, R R; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bombara, M; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Callner, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chung, S U; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; DePhillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Feng, A; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Garcia-Solis, E; Ghazikhanian, V; Ghosh, P; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Grube, B; Guertin, S M; Guimaraes, K S F F; Gupta, N; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Heppelmann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Hofman, D J; Hollis, R S; Horner, M J; Huang, H Z; Hughes, E W; Humanic, T J; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Kettler, D; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kurnadi, P; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; LaPointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mitchell, J; Mohanty, B; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Nepali, C; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Planinic, M; Pluta, J; Poljak, N; Porile, N; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Qattan, I A; Raniwala, R; Raniwala, S; Ray, R L; Relyea, D; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Staszak, D; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Z; Surrow, B; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van der Kolk, N; van Leeuwen, M; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, J; Wu, Y; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yue, Q; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zhou, J; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2007-09-14

    We present first measurements of the phi-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from radical sNN=200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Omega to those of the phi as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT approximately 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R CP) of phi follows the trend observed in the K S 0 mesons rather than in Lambda baryons, supporting baryon-meson scaling. These data are consistent with phi mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.

  15. ΛΛ correlation function in Au + Au collisions at √ sNN = 200 GeV

    DOE PAGES

    Adamczyk, L.

    2015-01-12

    In this study, we present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at √ sNN = 200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for di-hyperon searches are discussed.

  16. Facile preparation of SERS and catalytically active Au nanostructures using furfuryl derivatives

    NASA Astrophysics Data System (ADS)

    Kim, Ki-Jung; Kim, Hyun-Chul; Park, Minsun; Huh, Seong

    2017-08-01

    Six different types of Au nanostructures with rough surfaces were readily prepared through the redox reactions between Au precursor, AuCl4-, and furfuryl derivatives without extra metal surface capping ligands, in deionized water at room temperature. Furfuryl alcohol (FA) or furfurylamine (FFA) was used as a sole reducing agent for the reduction of Au precursor. Both FA and FFA effectively polymerized during the redox reactions to form polyfuran polymers. These polymers are thought to act as surface capping ligands during the formation of Au nanostructures. Experiments were conducted with three different concentrations of each furfuryl derivative. Interestingly, Au particles prepared from the reaction with varying concentration of FA or FFA showed large differences in size, and revealed that the higher the ratios of [FA]/[AuCl4-] or [FFA]/[AuCl4-], the smaller the size of Au particles. The size of Au particles was in the range of 1 μm to under 30 nm. Among these samples, two nanostructured Au particles, AuFA-4 and AuFFA-1, deposited on a Si wafer by a simple drop-casting method, were revealed as highly active surface-enhanced Raman scattering (SERS) substrates for the detection of methylene blue (MB) and crystal violet (CV). High SERS enhancement factors (EFs) of 106 ∼ 108 for MB and CV were observed. Small size Au nanoparticles (AuFFA-2 and AuFFA-4) were also found to be very active for the catalytic hydrogenation of 4-nitrophenol to 4-aminophenol in the presence of NaBH4 at room temperature. AuFFA-2 could be recycled eight times, without losing its activity.

  17. Facing Aggression: Cues Differ for Female versus Male Faces

    PubMed Central

    Geniole, Shawn N.; Keyes, Amanda E.; Mondloch, Catherine J.; Carré, Justin M.; McCormick, Cheryl M.

    2012-01-01

    The facial width-to-height ratio (face ratio), is a sexually dimorphic metric associated with actual aggression in men and with observers' judgements of aggression in male faces. Here, we sought to determine if observers' judgements of aggression were associated with the face ratio in female faces. In three studies, participants rated photographs of female and male faces on aggression, femininity, masculinity, attractiveness, and nurturing. In Studies 1 and 2, for female and male faces, judgements of aggression were associated with the face ratio even when other cues in the face related to masculinity were controlled statistically. Nevertheless, correlations between the face ratio and judgements of aggression were smaller for female than for male faces (F1,36 = 7.43, p = 0.01). In Study 1, there was no significant relationship between judgements of femininity and of aggression in female faces. In Study 2, the association between judgements of masculinity and aggression was weaker in female faces than for male faces in Study 1. The weaker association in female faces may be because aggression and masculinity are stereotypically male traits. Thus, in Study 3, observers rated faces on nurturing (a stereotypically female trait) and on femininity. Judgements of nurturing were associated with femininity (positively) and masculinity (negatively) ratings in both female and male faces. In summary, the perception of aggression differs in female versus male faces. The sex difference was not simply because aggression is a gendered construct; the relationships between masculinity/femininity and nurturing were similar for male and female faces even though nurturing is also a gendered construct. Masculinity and femininity ratings are not associated with aggression ratings nor with the face ratio for female faces. In contrast, all four variables are highly inter-correlated in male faces, likely because these cues in male faces serve as “honest signals”. PMID:22276184

  18. Facing aggression: cues differ for female versus male faces.

    PubMed

    Geniole, Shawn N; Keyes, Amanda E; Mondloch, Catherine J; Carré, Justin M; McCormick, Cheryl M

    2012-01-01

    The facial width-to-height ratio (face ratio), is a sexually dimorphic metric associated with actual aggression in men and with observers' judgements of aggression in male faces. Here, we sought to determine if observers' judgements of aggression were associated with the face ratio in female faces. In three studies, participants rated photographs of female and male faces on aggression, femininity, masculinity, attractiveness, and nurturing. In Studies 1 and 2, for female and male faces, judgements of aggression were associated with the face ratio even when other cues in the face related to masculinity were controlled statistically. Nevertheless, correlations between the face ratio and judgements of aggression were smaller for female than for male faces (F(1,36) = 7.43, p = 0.01). In Study 1, there was no significant relationship between judgements of femininity and of aggression in female faces. In Study 2, the association between judgements of masculinity and aggression was weaker in female faces than for male faces in Study 1. The weaker association in female faces may be because aggression and masculinity are stereotypically male traits. Thus, in Study 3, observers rated faces on nurturing (a stereotypically female trait) and on femininity. Judgements of nurturing were associated with femininity (positively) and masculinity (negatively) ratings in both female and male faces. In summary, the perception of aggression differs in female versus male faces. The sex difference was not simply because aggression is a gendered construct; the relationships between masculinity/femininity and nurturing were similar for male and female faces even though nurturing is also a gendered construct. Masculinity and femininity ratings are not associated with aggression ratings nor with the face ratio for female faces. In contrast, all four variables are highly inter-correlated in male faces, likely because these cues in male faces serve as "honest signals".

  19. Elliptic Flow in Au+Au Collisions at √sNN = 130 GeV

    NASA Astrophysics Data System (ADS)

    Ackermann, K. H.; Adams, N.; Adler, C.; Ahammed, Z.; Ahmad, S.; Allgower, C.; Amsbaugh, J.; Anderson, M.; Anderssen, E.; Arnesen, H.; Arnold, L.; Averichev, G. S.; Baldwin, A.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Beddo, M.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Bennett, S.; Bercovitz, J.; Berger, J.; Betts, W.; Bichsel, H.; Bieser, F.; Bland, L. C.; Bloomer, M.; Blyth, C. O.; Boehm, J.; Bonner, B. E.; Bonnet, D.; Bossingham, R.; Botlo, M.; Boucham, A.; Bouillo, N.; Bouvier, S.; Bradley, K.; Brady, F. P.; Braithwaite, E. S.; Braithwaite, W.; Brandin, A.; Brown, R. L.; Brugalette, G.; Byrd, C.; Caines, H.; Calderón de La Barca Sánchez, M.; Cardenas, A.; Carr, L.; Carroll, J.; Castillo, J.; Caylor, B.; Cebra, D.; Chatopadhyay, S.; Chen, M. L.; Chen, W.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Chrin, J.; Christie, W.; Coffin, J. P.; Conin, L.; Consiglio, C.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Danilov, V. I.; Dayton, D.; Demello, M.; Deng, W. S.; Derevschikov, A. A.; Dialinas, M.; Diaz, H.; Deyoung, P. A.; Didenko, L.; Dimassimo, D.; Dioguardi, J.; Dominik, W.; Drancourt, C.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Eggert, T.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Etkin, A.; Fachini, P.; Feliciano, C.; Ferenc, D.; Ferguson, M. I.; Fessler, H.; Finch, E.; Fine, V.; Fisyak, Y.; Flierl, D.; Flores, I.; Foley, K. J.; Fritz, D.; Gagunashvili, N.; Gans, J.; Gazdzicki, M.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Gojak, C.; Grabski, J.; Grachov, O.; Grau, M.; Greiner, D.; Greiner, L.; Grigoriev, V.; Grosnick, D.; Gross, J.; Guilloux, G.; Gushin, E.; Hall, J.; Hallman, T. J.; Hardtke, D.; Harper, G.; Harris, J. W.; He, P.; Heffner, M.; Heppelmann, S.; Herston, T.; Hill, D.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Howe, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Hunt, W.; Hunter, J.; Igo, G. J.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Jacobson, S.; Jared, R.; Jensen, P.; Johnson, I.; Jones, P. G.; Judd, E.; Kaneta, M.; Kaplan, M.; Keane, D.; Kenney, V. P.; Khodinov, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Koehler, G.; Konstantinov, A. S.; Kormilitsyne, V.; Kotchenda, L.; Kotov, I.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Krupien, T.; Kuczewski, P.; Kuhn, C.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamas-Valverde, J.; Lamont, M. A.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lecompte, T.; Leonhardt, W. J.; Leontiev, V. M.; Leszczynski, P.; Levine, M. J.; Li, Q.; Li, Q.; Li, Z.; Liaw, C.-J.; Lin, J.; Lindenbaum, S. J.; Lindenstruth, V.; Lindstrom, P. J.; Lisa, M. A.; Liu, H.; Ljubicic, T.; Llope, W. J.; Locurto, G.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Lopiano, D.; Love, W. A.; Lutz, J. R.; Lynn, D.; Madansky, L.; Maier, R.; Majka, R.; Maliszewski, A.; Margetis, S.; Marks, K.; Marstaller, R.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; Matyushevski, E. A.; McParland, C.; McShane, T. S.; Meier, J.; Melnick, Yu.; Meschanin, A.; Middlekamp, P.; Mikhalin, N.; Miller, B.; Milosevich, Z.; Minaev, N. G.; Minor, B.; Mitchell, J.; Mogavero, E.; Moiseenko, V. A.; Moltz, D.; Moore, C. F.; Morozov, V.; Morse, R.; de Moura, M. M.; Munhoz, M. G.; Mutchler, G. S.; Nelson, J. M.; Nevski, P.; Ngo, T.; Nguyen, M.; Nguyen, T.; Nikitin, V. A.; Nogach, L. V.; Noggle, T.; Norman, B.; Nurushev, S. B.; Nussbaum, T.; Nystrand, J.; Odyniec, G.; Ogawa, A.; Ogilvie, C. A.; Olchanski, K.; Oldenburg, M.; Olson, D.; Ososkov, G. A.; Ott, G.; Padrazo, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Pentia, M.; Perevotchikov, V.; Peryt, W.; Petrov, V. A.; Pinganaud, W.; Pirogov, S.; Platner, E.; Pluta, J.; Polk, I.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Puskar-Pasewicz, J.; Rai, G.; Rasson, J.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J.; Renfordt, R. E.; Retiere, F.; Ridiger, A.; Riso, J.; Ritter, H. G.; Roberts, J. B.; Roehrich, D.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Russ, D.; Rykov, V.; Sakrejda, I.; Sanchez, R.; Sandler, Z.; Sandweiss, J.; Sappenfield, P.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Scheblien, J.; Scheetz, R.; Schlueter, R.; Schmitz, N.; Schroeder, L. S.; Schulz, M.; Schüttauf, A.; Sedlmeir, J.; Seger, J.; Seliverstov, D.; Seyboth, J.; Seyboth, P.; Seymour, R.; Shakaliev, E. I.; Shestermanov, K. E.; Shi, Y.; Shimanskii, S. S.; Shuman, D.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Smykov, L. P.; Snellings, R.; Solberg, K.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Stone, N.; Stone, R.; Strikhanov, M.; Stringfellow, B.; Stroebele, H.; Struck, C.; Suaide, A. A.; Sugarbaker, E.; Suire, C.; Symons, T. J.; Takahashi, J.; Tang, A. H.; Tarchini, A.; Tarzian, J.; Thomas, J. H.; Tikhomirov, V.; Szanto de Toledo, A.; Tonse, S.; Trainor, T.; Trentalange, S.; Tokarev, M.; Tonjes, M. B.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; Vakula, I.; van Buren, G.; Vandermolen, A. M.; Vanyashin, A.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Visser, G.; Voloshin, S. A.; Vu, C.; Wang, F.; Ward, H.; Weerasundara, D.; Weidenbach, R.; Wells, R.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitfield, J. P.; Whitten, C.; Wieman, H.; Willson, R.; Wilson, K.; Wirth, J.; Wisdom, J.; Wissink, S. W.; Witt, R.; Wolf, J.; Wood, L.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yokosawa, A.; Yurevich, V. I.; Zanevski, Y. V.; Zhang, J.; Zhang, W. M.; Zhu, J.; Zimmerman, D.; Zoulkarneev, R.; Zubarev, A. N.

    2001-01-01

    Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at sNN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

  20. The many faces of research on face perception.

    PubMed

    Little, Anthony C; Jones, Benedict C; DeBruine, Lisa M

    2011-06-12

    Face perception is fundamental to human social interaction. Many different types of important information are visible in faces and the processes and mechanisms involved in extracting this information are complex and can be highly specialized. The importance of faces has long been recognized by a wide range of scientists. Importantly, the range of perspectives and techniques that this breadth has brought to face perception research has, in recent years, led to many important advances in our understanding of face processing. The articles in this issue on face perception each review a particular arena of interest in face perception, variously focusing on (i) the social aspects of face perception (attraction, recognition and emotion), (ii) the neural mechanisms underlying face perception (using brain scanning, patient data, direct stimulation of the brain, visual adaptation and single-cell recording), and (iii) comparative aspects of face perception (comparing adult human abilities with those of chimpanzees and children). Here, we introduce the central themes of the issue and present an overview of the articles.

  1. Rho0 production and possible modification in Au+Au and p+p collisions at square root [sNN] = 200 GeV.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Ganti, M S; Gaudichet, L; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grebenyuk, O; Gronstal, S; Grosnick, D; Guertin, S M; Gupta, A; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Hughes, E; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mischke, A; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, D A; Morozov, V; De Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Varma, R; Vasilevski, I; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Vznuzdaev, M; Waggoner, W; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Yuting, B; Zanevski, Y V; Zhang, H; Zhang, W M; Zhang, Z P; Zhaomin, Z P; Zizong, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2004-03-05

    We report results on rho(770)(0)-->pi(+)pi(-) production at midrapidity in p+p and peripheral Au+Au collisions at sqrt[s(NN)]=200 GeV. This is the first direct measurement of rho(770)(0)-->pi(+)pi(-) in heavy-ion collisions. The measured rho(0) peak in the invariant mass distribution is shifted by approximately 40 MeV/c(2) in minimum bias p+p interactions and approximately 70 MeV/c(2) in peripheral Au+Au collisions. The rho(0) mass shift is dependent on transverse momentum and multiplicity. The modification of the rho(0) meson mass, width, and shape due to phase space and dynamical effects are discussed.

  2. Au-assisted fabrication of nano-holes on c-plane sapphire via thermal treatment guided by Au nanoparticles as catalysts

    NASA Astrophysics Data System (ADS)

    Sui, Mao; Pandey, Puran; Li, Ming-Yu; Zhang, Quanzhen; Kunwar, Sundar; Lee, Jihoon

    2017-01-01

    Nanoscale patterning of sapphires is a challenging task due to the high mechanical strength, chemical stability as well as thermal durability. In this paper, we demonstrate a gold droplet assisted approach of nano-hole fabrication on c-plane sapphire via a thermal treatment. Uniformly distributed nano-holes are fabricated on the sapphire surface guided by dome shaped Au nanoparticles (NPs) as catalysts and the patterning process is discussed based on the disequilibrium of vapor, liquid, solid interface energies at the Au NP/sapphire interface induced by the Au evaporation at high temperature. Followed by the re-equilibration of interface energy, transport of alumina from the beneath of NPs to the sapphire surface can occur along the NP/sapphire interface resulting in the formation of nano-holes. The fabrication of nano-holes using Au NPs as catalysts is a flexible, economical and convenient approach and can find applications in various optoelectronics.

  3. Au-Ag-Au double shell nanoparticles-based localized surface plasmon resonance and surface-enhanced Raman scattering biosensor for sensitive detection of 2-mercapto-1-methylimidazole.

    PubMed

    Liao, Xue; Chen, Yanhua; Qin, Meihong; Chen, Yang; Yang, Lei; Zhang, Hanqi; Tian, Yuan

    2013-12-15

    In this paper, Au-Ag-Au double shell nanoparticles were prepared based on the reduction of the metal salts HAuCl4 and AgNO3 at the surface of seed particles. Due to the synergistic effect between Au and Ag, the hybrid nanoparticles are particularly stable and show excellent performances on the detection of 2-mercapto-1-methylimidazole (methimazole). The binding of target molecule at the surface of Au-Ag-Au double shell nanoparticles was demonstrated based on both localized surface plasmon resonance (LSPR) and surface-enhanced Raman scattering (SERS) spectra. The LSPR intensity is directly proportional to the methimazole concentration in the range of 0.10-3.00×10(-7) mol L(-1). The SERS spectrum can be applied in identification of methimazole molecule. The LSPR coupled with SERS based on the Au-Ag-Au double shell nanoparticles would be very attractive for the quantitative determination and qualitative analysis of the analytes in medicines. © 2013 Elsevier B.V. All rights reserved.

  4. An audit of the impact of a consultation with a paediatric dermatology team on quality of life in infants with atopic eczema and their families: further validation of the Infants' Dermatitis Quality of Life Index and Dermatitis Family Impact score.

    PubMed

    Beattie, P E; Lewis-Jones, M S

    2006-12-01

    Atopic dermatitis (AD) accounts for 10-20% of referrals to secondary care dermatology, often requiring multiple visits and occupying much valuable time and resources. We audited the usefulness (ease of use, reliability and sensitivity to change) of two simple and easy to use quality of life (QoL) measures, the Infants' Dermatitis Quality of Life Index (IDQOL) and Dermatitis Family Impact (DFI), for assessing the impact on QoL of AD in infants and their families in a routine clinical setting. We also examined the impact of an initial consultation with a dermatology team on AD severity and QoL impairment from the parent's perspective. The parents of 203 infants (mean age 19.8 months) with AD attending paediatric dermatology clinics completed the DFI and IDQOL. The parents of 50 of these infants completed both questionnaires before first and second consultations. In the 203 children the mean of both the IDQOL and DFI scores was 8.47 (median 8 and 7 and SD 5.8 and 6.5, respectively). The IDQOL and DFI correlated well (r(s) = 0.776, P < 0.0001). The parent's assessment of the global severity of AD correlated well with the IDQOL score (r(s) = 0.636, P < 0.0001) but less well with the DFI (r(s) = 0.394, P < 0.001). The highest-scoring IDQOL items were itching and scratching, problems at bathtime and time taken to fall asleep. The highest-scoring DFI items were tiredness/exhaustion, sleep loss and emotional distress. In both measures these domains also correlated most strongly with eczema severity. After dermatology consultation the median global severity score, rated by 50 parents, fell from 2 (SD 0.83) to 1 (SD 0.8; 95% confidence interval, CI 0.5-1), the median IDQOL score fell from 8 (SD 5.92) to 5.5 (SD 5.92; 95% CI 2-5.5) and the median DFI score fell from 9 (SD 6.45) to 3 (SD 6.56; 95% CI 2-5.5). In 50 infants the median IDQOL scores for those infants with global AD severity scores of 1, 2 and 3 were 5 (SD 5.65), 8 (SD 4.27) and 14 (SD 5.67), respectively and

  5. Stream dynamics between 1 AU and 2 AU: A detailed comparison of observations and theory

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Pizzo, V.; Lazarus, A.; Gazis, P. R.

    1984-01-01

    A radial alignment of three solar wind stream structures observed by IMP-7 and -8 (at 1.0 AU) and Voyager 1 and 2 (in the range 1.4 to 1.8 AU) in late 1977 is presented. It is demonstrated that several important aspects of the observed dynamical evolution can be both qualitatively and quantitatively described with a single-fluid 2-D MHD numerical model of quasi-steady corotating flow, including accurate prediction of: (1) the formation of a corotating shock pair at 1.75 AU in the case of a simple, quasi-steady stream; (2) the coalescence of the thermodynamic and magnetic structures associated with the compression regions of two neighboring, interacting, corotating streams; and (3) the dynamical destruction of a small (i.e., low velocity-amplitude, short spatial-scale) stream by its overtaking of a slower moving, high-density region associated with a preceding transient flow. The evolution of these flow systems is discussed in terms of the concepts of filtering and entrainment.

  6. Face-space: A unifying concept in face recognition research.

    PubMed

    Valentine, Tim; Lewis, Michael B; Hills, Peter J

    2016-10-01

    The concept of a multidimensional psychological space, in which faces can be represented according to their perceived properties, is fundamental to the modern theorist in face processing. Yet the idea was not clearly expressed until 1991. The background that led to the development of face-space is explained, and its continuing influence on theories of face processing is discussed. Research that has explored the properties of the face-space and sought to understand caricature, including facial adaptation paradigms, is reviewed. Face-space as a theoretical framework for understanding the effect of ethnicity and the development of face recognition is evaluated. Finally, two applications of face-space in the forensic setting are discussed. From initially being presented as a model to explain distinctiveness, inversion, and the effect of ethnicity, face-space has become a central pillar in many aspects of face processing. It is currently being developed to help us understand adaptation effects with faces. While being in principle a simple concept, face-space has shaped, and continues to shape, our understanding of face perception.

  7. Structural and dynamical properties of liquid Al-Au alloys

    NASA Astrophysics Data System (ADS)

    Peng, H. L.; Voigtmann, Th.; Kolland, G.; Kobatake, H.; Brillo, J.

    2015-11-01

    We investigate temperature- and composition-dependent structural and dynamical properties of Al-Au melts. Experiments are performed to obtain accurate density and viscosity data. The system shows a strong negative excess volume, similar to other Al-based binary alloys. We develop a molecular-dynamics (MD) model of the melt based on the embedded-atom method (EAM), gauged against the available experimental liquid-state data. A rescaling of previous EAM potentials for solid-state Au and Al improves the quantitative agreement with experimental data in the melt. In the MD simulation, the admixture of Au to Al can be interpreted as causing a local compression of the less dense Al system, driven by less soft Au-Au interactions. This local compression provides a microscopic mechanism explaining the strong negative excess volume of the melt. We further discuss the concentration dependence of self- and interdiffusion and viscosity in the MD model. Al atoms are more mobile than Au, and their increased mobility is linked to a lower viscosity of the melt.

  8. Size exclusion chromatography for semipreparative scale separation of Au38(SR)24 and Au40(SR)24 and larger clusters.

    PubMed

    Knoppe, Stefan; Boudon, Julien; Dolamic, Igor; Dass, Amala; Bürgi, Thomas

    2011-07-01

    Size exclusion chromatography (SEC) on a semipreparative scale (10 mg and more) was used to size-select ultrasmall gold nanoclusters (<2 nm) from polydisperse mixtures. In particular, the ubiquitous byproducts of the etching process toward Au(38)(SR)(24) (SR, thiolate) clusters were separated and gained in high monodispersity (based on mass spectrometry). The isolated fractions were characterized by UV-vis spectroscopy, MALDI mass spectrometry, HPLC, and electron microscopy. Most notably, the separation of Au(38)(SR)(24) and Au(40)(SR)(24) clusters is demonstrated.

  9. Secondary ion mass spectroscopy study of Au trapping and migration in the Au-irradiated YBa2Cu3O7 - delta film

    NASA Astrophysics Data System (ADS)

    Li, Yupu; Kilner, J. A.; Liu, J. R.; Chu, W. K.; Wagner, G. A.; Somekh, R. E.

    1996-05-01

    The range data and migration of Au in YBa2Cu3O7-δ film were studied with implanted 197Au (1.5 MeV 5×1015 Au+/cm2) as a tracer. The film was a c-axis oriented film, ˜750 nm thick, deposited by high-pressure planar dc sputtering on <100> LaAlO3. Analysis by secondary ion mass spectroscopy shows that the as-implanted Au concentration distribution is essentially Gaussian-like and the depth (R̂p) of maximum Au concentration (˜1.2 wt %) is 201 nm. The projected range (R¯p) and (R̂p) are found to be in very good agreement with the simulated data by TRIM-95, whereas the measured ``straggle'' (ΔRp*) is about 20% larger than that by TRIM-95 simulation. It has also been found that the implanted 197Au starts to migrate within the film at a temperature between 650 and 700 °C, which is much higher than that for the implanted 2H (˜175 °C) and the implanted 18O (between 250 and 300 °C) in c-oriented YBa2Cu3O7-δ films.

  10. Evaluation of chromatin integrity of motile bovine spermatozoa capacitated in vitro.

    PubMed

    Reckova, Z; Machatkova, M; Rybar, R; Horakova, J; Hulinska, P; Machal, L

    2008-08-01

    The efficiency of in vitro embryo production is highly variable amongst individual sires in cattle. To eliminate that this variability is not caused by sperm chromatin damage caused by separation or capacitacion, chromatin integrity was evaluated. Seventeen of AI bulls with good NRRs but variable embryo production efficiency were used. For each bull, motile spermatozoa were separated on a Percoll gradient, resuspended in IVF-TALP medium and capacitated with or incubated without heparin for 6 h. Samples before and after separation and after 3-h and 6-h capacitacion or incubation were evaluated by the Sperm Chromatin Structure Assay (SCSA) and the proportion of sperm with intact chromatin structure was calculated. Based on changes in the non-DFI-sperm proportion, the sires were categorized as DNA-unstable (DNA-us), DNA-stable (DNA-s) and DNA-most stable (DNA-ms) bulls (n=3, n=5 and n=9, respectively). In DNA-us bulls, separation produced a significant increase of the mean non-DFI-sperm proportion (p DFI-sperm proportion in H+ sperm (p DFI-sperm proportion (p DFI-sperm proportion remained almost unchanged. In DNA-ms bulls, neither separation nor capacitacion had any effect on the mean non-DFI-sperm proportion. It can be concluded that, although separation and capacitacion may produce some changes in sperm chromatin integrity, these are not associated with different in vitro fertility of the bulls involved.

  11. Cationic gemini surfactant-assisted synthesis of hollow Au nanostructures by stepwise reductions.

    PubMed

    Wang, Wentao; Han, Yuchun; Tian, Maozhang; Fan, Yaxun; Tang, Yongqiang; Gao, Mingyuan; Wang, Yilin

    2013-06-26

    A novel synthetic approach was developed for creating versatile hollow Au nanostructures by stepwise reductions of Au(III) upon the use of cationic gemini surfactant hexamethylene-1,6-bis(dodecyl dimethylammonium bromide) (C12C6C12Br2) as a template agent. It was observed that the Au(I) ions obtained from the reduction of Au(III) by ascorbic acid can assist the gemini surfactant to form vesicles, capsule-like, and tube-like aggregates that subsequently act as soft templates for hollow Au nanostructures upon further reduction of Au(I) to Au(0) by NaBH4. It was demonstrated that the combination of C12C6C12Br2 and Au(I) plays a key role in regulating the structure of the hollow precursors not only because C12C6C12Br2 has a stronger aggregation ability in comparison with its single chain counterpart but also because the electrostatic repulsion between head groups of C12C6C12Br2 is greatly weakened after Au(III) is converted to Au(I), which is in favor of the construction of vesicles, capsule-like, and tube-like aggregates. Compared with solid Au nanospheres, the resultant hollow nanostructures exhibit enhanced electrocatalytic activities in methanol oxidation, following the order of elongated nanocapsule > nanocapsule > nanosphere. Benefiting from balanced interactions between the gemini surfactant and Au(I), this soft-template method may present a facile and versatile approach for the controlled synthesis of Au nanostructures potentially useful for fuel cells and other Au nanodevices.

  12. Energy dependence of J/ψ production in Au + Au collisions at √{sNN} = 39 , 62.4 and 200GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fujita, J.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, T.; Huang, X.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Y.; Li, X.; Li, W.; Li, C.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, Y.; Liu, H.; Liu, F.; Liu, P.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shi, Z.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration

    2017-08-01

    The inclusive J / ψ transverse momentum spectra and nuclear modification factors are reported at mid-rapidity (| y | < 1.0) in Au + Au collisions at √{sNN} = 39, 62.4 and 200 GeV taken by the STAR experiment. A suppression of J / ψ production, with respect to the production in p + p scaled by the number of binary nucleon-nucleon collisions, is observed in central Au + Au collisions at these three energies. No significant energy dependence of nuclear modification factors is found within uncertainties. The measured nuclear modification factors can be described by model calculations that take into account both suppression of direct J / ψ production due to the color screening effect and J / ψ regeneration from recombination of uncorrelated charm-anticharm quark pairs.

  13. Nonlinear absorption enhancement of AuNPs based polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Zulina, Natalia A.; Baranov, Mikhail A.; Kniazev, Kirill I.; Kaliabin, Viacheslav O.; Denisyuk, Igor Yu.; Achor, Susan U.; Sitnikova, Vera E.

    2018-07-01

    Au nanoparticles (AuNPs) based polymer nanocomposites with high nonlinear absorption coefficient were synthesized by UV-photocuring. AuNPs were synthesized by laser ablation method in liquid monomer isodecyl acrylate (IDA). In this research, two colloids with 70 nm and 20 nm nanoparticles average sizes were studied. Size control was performed with SEM and STEM. Prepared nanomaterials exhibit strong third-order nonlinear optical responses under CW laser irradiation at 532 nm, which was estimated by using z-scan technique performed with open aperture. It was found experimentally that nonlinear absorption β is almost twice higher for nanocomposites with smaller AuNPs.

  14. Divided café-au-lait macule of the mouth.

    PubMed

    Sergay, Amanda; Silverberg, Nanette B

    2007-05-01

    We describe a 4-year-old, otherwise healthy boy with a congenital history of a perioral and labial segmental café-au-lait macule, who was noted to have unilateral localized gingival hyperpigmentation that aligned with the café-au-lait macule. This case is highly illustrative of the embryologic timing of the genetic event locally, which leads to café-au-lait type hyperpigmentation. Because the facial features and the ectoderm overlying the facial muscles develop around the third to fourth week of gestation, the distribution of this café-au-lait macule suggests development at the same time.

  15. Spin Polarization and Quantum Spins in Au Nanoparticles

    PubMed Central

    Li, Chi-Yen; Karna, Sunil K.; Wang, Chin-Wei; Li, Wen-Hsien

    2013-01-01

    The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter. PMID:23989607

  16. Seeing faces is necessary for face-domain formation.

    PubMed

    Arcaro, Michael J; Schade, Peter F; Vincent, Justin L; Ponce, Carlos R; Livingstone, Margaret S

    2017-10-01

    Here we report that monkeys raised without exposure to faces did not develop face domains, but did develop domains for other categories and did show normal retinotopic organization, indicating that early face deprivation leads to a highly selective cortical processing deficit. Therefore, experience must be necessary for the formation (or maintenance) of face domains. Gaze tracking revealed that control monkeys looked preferentially at faces, even at ages prior to the emergence of face domains, but face-deprived monkeys did not, indicating that face looking is not innate. A retinotopic organization is present throughout the visual system at birth, so selective early viewing behavior could bias category-specific visual responses toward particular retinotopic representations, thereby leading to domain formation in stereotyped locations in inferotemporal cortex, without requiring category-specific templates or biases. Thus, we propose that environmental importance influences viewing behavior, viewing behavior drives neuronal activity, and neuronal activity sculpts domain formation.

  17. Glucose-functionalized Au nanoprisms for optoacoustic imaging and near-infrared photothermal therapy

    NASA Astrophysics Data System (ADS)

    Han, Jishu; Zhang, Jingjing; Yang, Meng; Cui, Daxiang; de La Fuente, Jesus M.

    2015-12-01

    Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through photothermal therapy. The current work demonstrates the great potential of Au@PEG-Glc NPrs in optoacoustic imaging and photothermal cancer therapy in future.Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through

  18. Improvement on electrical conductivity and electron field emission properties of Au-ion implanted ultrananocrystalline diamond films by using Au-Si eutectic substrates

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sankaran, K. J.; Institute for Materials Research; Sundaravel, B.

    2015-08-28

    In the present work, Au-Si eutectic layer was used to enhance the electrical conductivity/electron field emission (EFE) properties of Au-ion implanted ultrananocrystalline diamond (Au-UNCD) films grown on Si substrates. The electrical conductivity was improved to a value of 230 (Ω cm){sup −1}, and the EFE properties was enhanced reporting a low turn-on field of 2.1 V/μm with high EFE current density of 5.3 mA/cm{sup 2} (at an applied field of 4.9 V/μm) for the Au-UNCD films. The formation of SiC phase circumvents the formation of amorphous carbon prior to the nucleation of diamond on Si substrates. Consequently, the electron transport efficiency of themore » UNCD-to-Si interface increases, thereby improving the conductivity as well as the EFE properties. Moreover, the salient feature of these processes is that the sputtering deposition of Au-coating for preparing the Au-Si interlayer, the microwave plasma enhanced chemical vapor deposition process for growing the UNCD films, and the Au-ion implantation process for inducing the nanographitic phases are standard thin film preparation techniques, which are simple, robust, and easily scalable. The availability of these highly conducting UNCD films with superior EFE characteristics may open up a pathway for the development of high-definition flat panel displays and plasma devices.« less

  19. Tri-metallic PtPdAu mesoporous nanoelectrocatalysts.

    PubMed

    Li, Chunjie; Wang, Hongjing; Li, Yinghao; Yu, Hongjie; Yin, Shuli; Xue, Hairong; Li, Xiaonian; Xu, You; Wang, Liang

    2018-06-22

    The design of mesoporous materials with multi-metallic compositions is highly important for various electrocatalytic applications. In this paper, we demonstrate an efficient method to directly fabricate tri-metallic PtPdAu mesoporous nanoparticles (PtPdAu MNs) in a high yield, which is simply performed by heating treatment of the reaction mixture aqueous solution at 40 °C for 4 h. Profiting from its mesoporous structure and multi-metallic components, the as-prepared PtPdAu MNs exhibit enhanced electrocatalytic activities toward both methanol oxidation reaction and oxygen reduction reaction in comparison with bi-metallic PtPd MNs and commercial Pt/C catalyst.

  20. Tri-metallic PtPdAu mesoporous nanoelectrocatalysts

    NASA Astrophysics Data System (ADS)

    Li, Chunjie; Wang, Hongjing; Li, Yinghao; Yu, Hongjie; Yin, Shuli; Xue, Hairong; Li, Xiaonian; Xu, You; Wang, Liang

    2018-06-01

    The design of mesoporous materials with multi-metallic compositions is highly important for various electrocatalytic applications. In this paper, we demonstrate an efficient method to directly fabricate tri-metallic PtPdAu mesoporous nanoparticles (PtPdAu MNs) in a high yield, which is simply performed by heating treatment of the reaction mixture aqueous solution at 40 °C for 4 h. Profiting from its mesoporous structure and multi-metallic components, the as-prepared PtPdAu MNs exhibit enhanced electrocatalytic activities toward both methanol oxidation reaction and oxygen reduction reaction in comparison with bi-metallic PtPd MNs and commercial Pt/C catalyst.

  1. Finding Hope in the Face-to-Face.

    PubMed

    Edgoose, Jennifer Y C; Edgoose, Julian M

    2017-05-01

    What does it mean to look into the face of a patient who looks back? Face-to-face encounters are at the heart of the patient-clinician relationship but their singular significance is often lost amid the demands of today's high-tech, metric-driven health care systems. Using the framework provided by the philosopher and Holocaust survivor Emmanuel Levinas, the authors explore the unique responsibility and potential for hope found only in face-to-face encounters. Revisiting this most fundamental attribute of medicine is likely our greatest chance to reclaim who we are as clinicians and why we do what we do. © 2017 Annals of Family Medicine, Inc.

  2. Interet du Lambeau Hypogastrique Dans le Traitement des Sequelles de Brulure de la Face Dorsale de la Main

    PubMed Central

    Tourabi, K.; Moussaoui, A.; Ribag, Y.; Ihrai, H.

    2010-01-01

    Summary Le lambeau hypogastrique est un lambeau cutané axial, vascularisé par le pédicule épigastrique inférieur superficiel. Il constitue un des moyens efficaces pour la couverture de la face postérieure de la main et du poignet. Quatre patients ont bénéficié de la couverture de la perte de substance après que l’excision du placard cicatriciel a fait appel au lambeau hypogastrique sevré au 21ème jour. Les résultats esthétiques et fonctionnels étaient plutôt satisfaisants. Ce lambeau constitue une technique de choix dans le traitement des séquelles de brûlures de la main avec exposition des éléments nobles; de dissection facile, donne peu de complications, et nécessite des retouches à distance pour obtenir un résultat optimal. PMID:21991214

  3. Registration of ‘AU-1101’ peanut

    USDA-ARS?s Scientific Manuscript database

    AU-1101’ (Reg. No. CV-xxx, PI 661498) is a large-seeded virginia-type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) with high yield and medium maturity, uniform pod size and shape, high grade, superior shelling characters, low oil content, normal oleic acid content, and good flavor. AU-...

  4. Measurements of electrons from semi-leptonic heavy flavor decays in p+p and Au+Au collisions at √{sNN } = 200 GeV at STAR

    NASA Astrophysics Data System (ADS)

    Wang, Yaping; STAR Collaboration

    2017-08-01

    In these proceedings, we present recent results on electrons from semi-leptonic decays of open heavy-flavor hadrons (eHF) with the STAR detector at the Relativistic Heavy Ion Collider. We report the updated measurements of eHF production in p+p collisions at √{ s } = 200 GeV with significantly improved precision and wider kinematic coverage than previous measurements. With this new p+p reference, we obtain the nuclear modification factor (RAA) for eHF in Au+Au collisions at √{sNN } = 200 GeV using 2010 data. The RAA shows significant suppression at high pT in most central Au+Au collisions, while the suppression reduces gradually towards more peripheral collisions. We compare eHFRAA in central Au+Au collisions to that in central U+U collisions at √{sNN } = 193 GeV and find that they are consistent within uncertainties. We also show the results of B-hadron contribution to eHF extracted from azimuthal correlations between eHF and charged hadrons in p+p collisions. Finally we report the measurements of eHF from open bottom hadron decays and discuss the prospect of measuring eHF from open bottom and charm hadron decays separately utilizing the Heavy Flavor Tracker in Au+Au collisions.

  5. The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits

    NASA Astrophysics Data System (ADS)

    Deditius, Artur P.; Reich, Martin; Kesler, Stephen E.; Utsunomiya, Satoshi; Chryssoulis, Stephen L.; Walshe, John; Ewing, Rodney C.

    2014-09-01

    The ubiquity of Au-bearing arsenian pyrite in hydrothermal ore deposits suggests that the coupled geochemical behaviour of Au and As in this sulfide occurs under a wide range of physico-chemical conditions. Despite significant advances in the last 20 years, fundamental factors controlling Au and As ratios in pyrite from ore deposits remain poorly known. Here we explore these constraints using new and previously published EMPA, LA-ICP-MS, SIMS, and μ-PIXE analyses of As and Au in pyrite from Carlin-type Au, epithermal Au, porphyry Cu, Cu-Au, and orogenic Au deposits, volcanogenic massive sulfide (VHMS), Witwatersrand Au, iron oxide copper gold (IOCG), and coal deposits. Pyrite included in the data compilation formed under temperatures from ∼30 to ∼600 °C and in a wide variety of geological environments. The pyrite Au-As data form a wedge-shaped zone in compositional space, and the fact that most data points plot below the solid solubility limit defined by Reich et al. (2005) indicate that Au1+ is the dominant form of Au in arsenian pyrite and that Au-bearing ore fluids that deposit this sulfide are mostly undersaturated with respect to native Au. The analytical data also show that the solid solubility limit of Au in arsenian pyrite defined by an Au/As ratio of 0.02 is independent of the geochemical environment of pyrite formation and rather depends on the crystal-chemical properties of pyrite and post-depositional alteration. Compilation of Au-As concentrations and formation temperatures for pyrite indicates that Au and As solubility in pyrite is retrograde; Au and As contents decrease as a function of increasing temperature from ∼200 to ∼500 °C. Based on these results, two major Au-As trends for Au-bearing arsenian pyrite from ore deposits are defined. One trend is formed by pyrites from Carlin-type and orogenic Au deposits where compositions are largely controlled by fluid-rock interactions and/or can be highly perturbed by changes in temperature and

  6. Elliptic Flow of Identified Hadrons in Au+Au Collisions at (sNN)=200 GeV

    NASA Astrophysics Data System (ADS)

    Adler, S. S.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Alexander, J.; Amirikas, R.; Aphecetche, L.; Aronson, S. H.; Averbeck, R.; Awes, T. C.; Azmoun, R.; Babintsev, V.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bazilevsky, A.; Belikov, S.; Berdnikov, Y.; Bhagavatula, S.; Boissevain, J. G.; Borel, H.; Borenstein, S.; Brooks, M. L.; Brown, D. S.; Bruner, N.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camard, X.; Chai, J.-S.; Chand, P.; Chang, W. C.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J.; Choudhury, R. K.; Chujo, T.; Cianciolo, V.; Cobigo, Y.; Cole, B. A.; Constantin, P.; D'Enterria, D. G.; David, G.; Delagrange, H.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Drapier, O.; Drees, A.; Du Rietz, R.; Durum, A.; Dutta, D.; Efremenko, Y. V.; El Chenawi, K.; Enokizono, A.; En'yo, H.; Esumi, S.; Ewell, L.; Fields, D. E.; Fleuret, F.; Fokin, S. L.; Fox, B. D.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fung, S.-Y.; Garpman, S.; Ghosh, T. K.; Glenn, A.; Gogiberidze, G.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Guryn, W.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hamagaki, H.; Hansen, A. G.; Hartouni, E. P.; Harvey, M.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Heuser, J. M.; Hibino, M.; Hill, J. C.; Holzmann, W.; Homma, K.; Hong, B.; Hoover, A.; Ichihara, T.; Ikonnikov, V. V.; Imai, K.; Isenhower, L. D.; Ishihara, M.; Issah, M.; Isupov, A.; Jacak, B. V.; Jang, W. Y.; Jeong, Y.; Jia, J.; Jinnouchi, O.; Johnson, B. M.; Johnson, S. C.; Joo, K. S.; Jouan, D.; Kametani, S.; Kamihara, N.; Kang, J. H.; Kapoor, S. S.; Katou, K.; Kelly, S.; Khachaturov, B.; Khanzadeev, A.; Kikuchi, J.; Kim, D. H.; Kim, D. J.; Kim, D. W.; Kim, E.; Kim, G.-B.; Kim, H. J.; Kistenev, E.; Kiyomichi, A.; Kiyoyama, K.; Klein-Boesing, C.; Kobayashi, H.; Kochenda, L.; Kochetkov, V.; Koehler, D.; Kohama, T.; Kopytine, M.; Kotchetkov, D.; Kozlov, A.; Kroon, P. J.; Kuberg, C. H.; Kurita, K.; Kuroki, Y.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Ladygin, V.; Lajoie, J. G.; Lebedev, A.; Leckey, S.; Lee, D. M.; Lee, S.; Leitch, M. J.; Li, X. H.; Lim, H.; Litvinenko, A.; Liu, M. X.; Liu, Y.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Manko, V. I.; Mao, Y.; Martinez, G.; Marx, M. D.; Masui, H.; Matathias, F.; Matsumoto, T.; McGaughey, P. L.; Melnikov, E.; Messer, F.; Miake, Y.; Milan, J.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mischke, R. E.; Mishra, G. C.; Mitchell, J. T.; Mohanty, A. K.; Morrison, D. P.; Moss, J. M.; Mühlbacher, F.; Mukhopadhyay, D.; Muniruzzaman, M.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Nakamura, T.; Nandi, B. K.; Nara, M.; Newby, J.; Nilsson, P.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, K.; Ono, M.; Onuchin, V.; Oskarsson, A.; Otterlund, I.; Oyama, K.; Ozawa, K.; Pal, D.; Palounek, A. P.; Pantuev, V. S.; Papavassiliou, V.; Park, J.; Parmar, A.; Pate, S. F.; Peitzmann, T.; Peng, J.-C.; Peresedov, V.; Pinkenburg, C.; Pisani, R. P.; Plasil, F.; Purschke, M. L.; Purwar, A.; Rak, J.; Ravinovich, I.; Read, K. F.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosnet, P.; Ryu, S. S.; Sadler, M. E.; Saito, N.; Sakaguchi, T.; Sakai, M.; Sakai, S.; Samsonov, V.; Sanfratello, L.; Santo, R.; Sato, H. D.; Sato, S.; Sawada, S.; Schutz, Y.; Semenov, V.; Seto, R.; Shaw, M. R.; Shea, T. K.; Shibata, T.-A.; Shigaki, K.; Shiina, T.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, C. P.; Singh, V.; Sivertz, M.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sullivan, J. P.; Takagui, E. M.; Taketani, A.; Tamai, M.; Tanaka, K. H.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarján, P.; Tepe, J. D.; Thomas, T. L.; Tojo, J.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuruoka, H.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; van Hecke, H. W.; Velkovska, J.; Velkovsky, M.; Villatte, L.; Vinogradov, A. A.; Volkov, M. A.; Vznuzdaev, E.; Wang, X. R.; Watanabe, Y.; White, S. N.; Wohn, F. K.; Woody, C. L.; Xie, W.; Yang, Y.; Yanovich, A.; Yokkaichi, S.; Young, G. R.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

    2003-10-01

    The anisotropy parameter (v2), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in Au+Au collisions at (sNN)=200 GeV for identified and inclusive charged particle production at central rapidities (|η|<0.35) with respect to the reaction plane defined at high rapidities (|η|=3 4 ). We observe that the v2 of mesons falls below that of (anti)baryons for pT>2 GeV/c, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.

  7. Assembling Bare Au Nanoparticles at Positively Charged Templates

    DOE PAGES

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; ...

    2016-05-26

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the charged-interfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits short-range in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), displaymore » less in-plane regular packing compared to bare AuNPs.« less

  8. Single electron yields from semileptonic charm and bottom hadron decays in Au + Au collisions at s N N = 200 GeV

    DOE PAGES

    Adare, A.; Aidala, C.; Ajitanand, N. N.; ...

    2016-03-07

    We measured open heavy flavor production in minimum bias Au + Au collisions at √s( NN) = 200 GeV via the yields of electrons from semileptonic decays of charm and bottom hadrons, using the PHENIX Collaboration at the Relativistic Heavy Ion Collider. In the past, heavy flavor electron measurements indicated substantial modification in the momentum distribution of the parent heavy quarks owing to the quark-gluon plasma created in these collisions. For the first time, using the PHENIX silicon vertex detector to measure precision displaced tracking, the relative contributions from charm and bottom hadrons to these electrons as a function ofmore » transverse momentum are measured in Au + Au collisions. Here, we compare the fraction of electrons from bottom hadrons to previously published results extracted from electron-hadron correlations in p + p collisions at √s( NN) = 200 GeV and find the fractions to be similar within the large uncertainties on both measurements for p (T) > 4 GeV/c. We use the bottom electron fractions in Au + Au and p + p along with the previously measured heavy flavor electron R (AA) to calculate the R (AA) for electrons from charm and bottom hadron decays separately. Finally, we find that electrons from bottom hadron decays are less suppressed than those from charm for the region 3 < p (T) < 4 GeV/c.« less

  9. Seeing faces is necessary for face-patch formation

    PubMed Central

    Arcaro, Michael J.; Schade, Peter F.; Vincent, Justin L.; Ponce, Carlos R.; Livingstone, Margaret S.

    2017-01-01

    Here we report that monkeys raised without exposure to faces did not develop face patches, but did develop domains for other categories, and did show normal retinotopic organization, indicating that early face deprivation leads to a highly selective cortical processing deficit. Therefore experience must be necessary for the formation, or maintenance, of face domains. Gaze tracking revealed that control monkeys looked preferentially at faces, even at ages prior to the emergence of face patches, but face-deprived monkeys did not, indicating that face looking is not innate. A retinotopic organization is present throughout the visual system at birth, so selective early viewing behavior could bias category-specific visual responses towards particular retinotopic representations, thereby leading to domain formation in stereotyped locations in IT, without requiring category-specific templates or biases. Thus we propose that environmental importance influences viewing behavior, viewing behavior drives neuronal activity, and neuronal activity sculpts domain formation. PMID:28869581

  10. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    PubMed Central

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants’ face recognition abilities are subject to “perceptual narrowing,” the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in developing humans and primates. Though the phenomenon is highly robust and replicable, there have been few efforts to model the emergence of perceptual narrowing as a function of the accumulation of experience with faces during infancy. The goal of the current study is to examine how perceptual narrowing might manifest as statistical estimation in “face space,” a geometric framework for describing face recognition that has been successfully applied to adult face perception. Here, I use a computer vision algorithm for Bayesian face recognition to study how the acquisition of experience in face space and the presence of race categories affect performance for own and other-race faces. Perceptual narrowing follows from the establishment of distinct race categories, suggesting that the acquisition of category boundaries for race is a key computational mechanism in developing face expertise. PMID:22709406

  11. Structural, electronic and magnetic properties of Au-based monolayer derivatives in honeycomb structure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kapoor, Pooja, E-mail: pupooja16@gmail.com; Sharma, Munish; Ahluwalia, P. K.

    2016-05-23

    We present electronic properties of atomic layer of Au, Au{sub 2}-N, Au{sub 2}-O and Au{sub 2}-F in graphene-like structure within the framework of density functional theory (DFT). The lattice constant of derived monolayers are found to be higher than the pristine Au monolayer. Au monolayer is metallic in nature with quantum ballistic conductance calculated as 4G{sub 0}. Similarly, Au{sub 2}-N and Au{sub 2}-F monolayers show 4G{sub 0} and 2G{sub 0} quantum conductance respectively while semiconducting nature with calculated band gap of 0.28 eV has been observed for Au{sub 2}-O monolayer. Most interestingly, half metalicity has been predicted for Au{sub 2}-Nmore » and Au{sub 2}-F monolayers. Our findings may have importance for the application of these monolayers in nanoelectronic and spintronics.« less

  12. Azimuthal Anisotropy in U +U and Au +Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, W.; Li, Y.; Li, C.; Li, Z. M.; Li, X.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, R.; Ma, Y. G.; Ma, G. L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, N.; Xu, Z.; Xu, Q. H.; Xu, H.; Yang, Y.; Yang, Y.; Yang, C.; Yang, S.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, J. B.; Zhang, J.; Zhang, Z.; Zhang, S.; Zhang, Y.; Zhang, J. L.; Zhao, F.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-11-01

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v2{2 } and v2{4 }, for charged hadrons from U +U collisions at √{sNN }=193 GeV and Au +Au collisions at √{sNN}=200 GeV . Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v2{2 } on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U +U collisions. We also show that v2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

  13. Au-nanocluster emission based glucose sensing.

    PubMed

    Hussain, A M P; Sarangi, S N; Kesarwani, J A; Sahu, S N

    2011-11-15

    Fabrication of a glucose biosensor based on Au-cluster emission quenching in the UV region is reported. The glucose biosensor is highly sensitive to β-d-glucose in 2.5-25.0mM range as confirmed from a linear calibration plot between Au-cluster colloid emission intensity as a function of β-d-glucose concentration. The interaction of β-d-glucose with l-cysteine capped Au cluster colloids has been confirmed from their Fourier transformed infrared spectroscopy (FTIR) measurements. It has been found that the biomolecules present in the serum such as ascorbic and uric acids, proteins and peptides do not interfere and affect in glucose estimation as confirmed from their absorption and fluorescence (FL) emission measurements. Practical utility of this sensor based on FL quenching method has been demonstrated by estimating the glucose level in human serum that includes diabetes and the data were found to be comparable or more accurate than those of the pathological data obtained from a local hospital. In addition, this biosensor is useful to detect glucose level over a wide range with sensor response time of the order of nano to picoseconds that is emission lifetime of Au clusters. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Contributions of individual face features to face discrimination.

    PubMed

    Logan, Andrew J; Gordon, Gael E; Loffler, Gunter

    2017-08-01

    Faces are highly complex stimuli that contain a host of information. Such complexity poses the following questions: (a) do observers exhibit preferences for specific information? (b) how does sensitivity to individual face parts compare? These questions were addressed by quantifying sensitivity to different face features. Discrimination thresholds were determined for synthetic faces under the following conditions: (i) 'full face': all face features visible; (ii) 'isolated feature': single feature presented in isolation; (iii) 'embedded feature': all features visible, but only one feature modified. Mean threshold elevations for isolated features, relative to full-faces, were 0.84x, 1.08, 2.12, 3.34, 4.07 and 4.47 for head-shape, hairline, nose, mouth, eyes and eyebrows respectively. Hence, when two full faces can be discriminated at threshold, the difference between the eyes is about four times less than what is required when discriminating between isolated eyes. In all cases, sensitivity was higher when features were presented in isolation than when they were embedded within a face context (threshold elevations of 0.94x, 1.74, 2.67, 2.90, 5.94 and 9.94). This reveals a specific pattern of sensitivity to face information. Observers are between two and four times more sensitive to external than internal features. The pattern for internal features (higher sensitivity for the nose, compared to mouth, eyes and eyebrows) is consistent with lower sensitivity for those parts affected by facial dynamics (e.g. facial expressions). That isolated features are easier to discriminate than embedded features supports a holistic face processing mechanism which impedes extraction of information about individual features from full faces. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The fabrication of nanopatterns with Au nanoparticles-embedded micelles via nanoimprint lithography.

    PubMed

    Lee, Jung-Pil; Kim, Eun-Uk; Koh, Haeng-Deog; Kang, Nam-Goo; Jung, Gun-Young; Lee, Jae-Suk

    2009-09-09

    We fabricated nanopatterns with Au nanoparticles-embedded micelles (Au-micelles) by self-assembly of block copolymers via nanoimprint lithography. The micelle structure prepared by self-assembled block copolymers was used as a template for the synthesis of Au nanoparticles (Au NPs). Au NPs were synthesized in situ inside the micelles of polystyrene-block-poly(2-vinylpyridine) (PS- b-P2VP). Au-micelles were arranged on the trenches of the polymer template, which was imprinted by nanoimprint lithography. The fabrication of line-type and dot-type nanopatterns was carried out by the combined method. In addition, multilayer nanopatterns of the Au-micelles were also proposed.

  16. Successful Decoding of Famous Faces in the Fusiform Face Area

    PubMed Central

    Axelrod, Vadim; Yovel, Galit

    2015-01-01

    What are the neural mechanisms of face recognition? It is believed that the network of face-selective areas, which spans the occipital, temporal, and frontal cortices, is important in face recognition. A number of previous studies indeed reported that face identity could be discriminated based on patterns of multivoxel activity in the fusiform face area and the anterior temporal lobe. However, given the difficulty in localizing the face-selective area in the anterior temporal lobe, its role in face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous faces in the temporo-frontal network of face-selective and adjacent non-face-selective regions. A special focus has been put on the face-area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that face-identity could be discriminated above chance level only in the fusiform face area. Our results corroborate the role of the fusiform face area in face recognition. Future studies are needed to further explore the role of the more recently discovered anterior face-selective areas in face recognition. PMID:25714434

  17. Successful decoding of famous faces in the fusiform face area.

    PubMed

    Axelrod, Vadim; Yovel, Galit

    2015-01-01

    What are the neural mechanisms of face recognition? It is believed that the network of face-selective areas, which spans the occipital, temporal, and frontal cortices, is important in face recognition. A number of previous studies indeed reported that face identity could be discriminated based on patterns of multivoxel activity in the fusiform face area and the anterior temporal lobe. However, given the difficulty in localizing the face-selective area in the anterior temporal lobe, its role in face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous faces in the temporo-frontal network of face-selective and adjacent non-face-selective regions. A special focus has been put on the face-area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that face-identity could be discriminated above chance level only in the fusiform face area. Our results corroborate the role of the fusiform face area in face recognition. Future studies are needed to further explore the role of the more recently discovered anterior face-selective areas in face recognition.

  18. Developmental Flight Instrumentation System for the Crew Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Crawford, Kevin; Thomas, John

    2006-01-01

    The National Aeronautics and Space Administration is developing a new launch vehicle to replace the Space Shuttle. The Crew Launch Vehicle (CLV) will be a combination of new design hardware and heritage Apollo and Space Shuttle hardware. The current CLV configuration is a 5 segment solid rocket booster first stage and a new upper stage design with a modified Apollo era J-2 engine. The current schedule has two test flights with a first stage and a structurally identical, but without engine, upper stage. Then there will be two more test flights with a full complement of flight hardware. After the completion of the test flights, the first manned flight to the International Space Station is scheduled for late 2012. To verify the CLV's design margins a developmental flight instrumentation (DFI) system is needed. The DFI system will collect environmental and health data from the various CLV subsystem's and either transmit it to the ground or store it onboard for later evaluation on the ground. The CLV consists of 4 major elements: the first stage, the upper stage, the upper stage engine and the integration of the first stage, upper stage and upper stage engine. It is anticipated that each of CLVs elements will have some version of DFI. This paper will discuss a conceptual DFI design for each element and also of an integrated CLV DFI system.

  19. Charge optimized many body (COMB) potentials for Pt and Au.

    PubMed

    Antony, A C; Akhade, S A; Lu, Z; Liang, T; Janik, M J; Phillpot, S R; Sinnott, S B

    2017-06-07

    Interatomic potentials for Pt and Au are developed within the third generation charge optimized many-body (COMB3) formalism. The potentials are capable of reproducing phase order, lattice constants, and elastic constants of Pt and Au systems as experimentally measured or calculated by density functional theory. We also fit defect formation energies, surface energies and stacking fault energies for Pt and Au metals. The resulting potentials are used to map a 2D contour of the gamma surface and simulate the tensile test of 16-grain polycrystalline Pt and Au structures at 300 K. The stress-strain behaviour is investigated and the primary slip systems {1 1 1}〈1 [Formula: see text] 0〉 are identified. In addition, we perform high temperature (1800 K for Au and 2300 K for Pt) molecular dynamics simulations of 30 nm Pt and Au truncated octahedron nanoparticles and examine morphological changes of each particle. We further calculate the activation energy barrier for surface diffusion during simulations of several nanoseconds and report energies of [Formula: see text] eV for Pt and [Formula: see text] eV for Au. This initial parameterization and application of the Pt and Au potentials demonstrates a starting point for the extension of these potentials to multicomponent systems within the COMB3 framework.

  20. Ethanol electrooxidation in alkaline medium on electrochemically synthesized Co(OH)2/Au composite

    NASA Astrophysics Data System (ADS)

    Babu, Sreejith P.; Elumalai, Perumal

    2017-01-01

    Gold (Au), cobalt hydroxide (Co(OH)2) and different Co(OH)2/Au compositions were electro-deposited onto stainless steel by a potentiodynamic method from the respective metal-ion solutions. The deposits were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transformed infra-red spectroscopy (FT-IR). The XRD and IR data confirmed that the deposits were Au, α-Co(OH)2 or Co(OH)2/Au composites. The SEM observations confirmed that the morphology of the Au was spherical, while the α-Co(OH)2 was flakey with pores. The morphology of the Co(OH)2/Au composites consisted of highly agglomerated Au grains distributed on the Co(OH)2 matrix. The electrocatalytic activity of each of the Au, Co(OH)2 and Co(OH)2/Au-composite electrodes towards ethanol electrooxidation in an alkaline medium was investigated by cyclic voltammetry and chronoamperometry. It turned out that the Co(OH)2/Au-composite electrodes exhibited superior catalytic activity for ethanol electrooxidation compared with the pristine Au or Co(OH)2 electrodes. A peak current density as high as 25 mA cm-2 was exhibited by the Co(OH)2/ Au composite while the Au and Co(OH)2 showed only 0.9 and 13 mA cm-2, respectively. The enhanced conductivity of the Co(OH)2/Au matrix due to the presence of Au, as well as the combined catalytic activity, seemed to be responsible for the superior performance of the Co(OH)2/Au-composite electrodes.

  1. Reconnaissance of the upper Au Sable River a cold-water river in the North-Central part of Michigan's southern peninsula

    USGS Publications Warehouse

    Hendrickson, G.E.; Doonan, C.J.

    1974-01-01

    The Au Sable River is one of Michigan’s most popular trout streams and canoe trails. Its riverside campgrounds are enjoyed by thousands of campers each year, and many cabins and homes have been built on its banks. At present, interests of the different recreationists – fishermen, canoers, campers, and riverside property owners – conflict. The conflict results from the face that the recreational potential is limited by the hydrologic characteristics of the river – its streamflow, quality of water, and character of stream channel, bed, and banks. The purpose of this report is to describe these characteristics and to show how they relate to the recreational potential of the stream.From its headwaters near Frederic the Au Sable flows southward to Grayling, then generally eastward to Lake Huron at Oscoda. Recreational use of the river is concentrated in the segment starting at Grayling and extending downstream to Wakeley Bridge, about 15 river miles. This report is concerned mainly with this part of the river.

  2. Preparation, Spectroscopic Characterization, and Frontier MO Study of the Heteronuclear Luminescent [Pt(2)Au(2)(dmb)(2)(PPh(3))(4)](PF(6))(2) Cluster (dmb = 1,8-Diisocyano-p-menthane). A Cluster with a Formal Au(0)-Au(0) Bond Encapsulated inside a "Pt(2)(dmb)(2)(2+) " Fragment.

    PubMed

    Zhang, Tianle; Drouin, Marc; Harvey, Pierre D.

    1999-11-01

    The title compound is prepared from the direct reaction of Pt(2)(dba)(3) (dba = dibenzylideneacetone) and [Au(PPh(3))(2)](PF(6)) in the presence of 1,8-diisocyano-p-methane (dmb), with Pt(2)(dmb)(2)Cl(2), [Pt(4)(dmb)(4)(PPh(3))(2)](PF(6))(2), and (PPh(3))AuCl being formed as parallel products. X-ray crystallography reveals the presence of a quasi-linear PPh(3)Au-AuPPh(3) fragment encapsulated inside a "Pt(2)(dmb)(2)(2+)" ring which is axially coordinated with two PPh(3) ligands. The d(AuAu) is 2.5977(6) Å and is indicative of a strong Au-Au single bond. The IR nu(CN) data reveal that the Pt oxidation state is I, which places the Au oxidation state at 0. The PtAu distances are 2.8422(5) and 2.8082(5) Å. The Raman-active nu(Au(2)), nu(PtAu) (b(2g) + a(g)), nu(PtP), nu(AuP), and nu(PtC) are found at 121.2, approximately 100, 85.5, 162.1, 183.1, and 457.2, and 440.9 cm(-)(1), respectively. The PtAu (0.67 mdyn Å(-)(1)) and Au(2) (1.21 mdyn Å(-)(1)) force constants (F) confirm the presence of medium PtAu and strong Au(2) bonding interactions. The absorption spectra are characterized by strong bands at lambda(max) (epsilon, M(-1) cm(-1)) at 316 (32 300), 366 (37 800), and 418 nm (21 500) and lower intensity features at 516 (2860) and 655 nm (834). The cluster is luminescent at low temperatures (solid and frozen glasses), and in the solid state at room temperature, and exhibits an emission band at approximately 875 nm, and an emission lifetime, tau(e), of 4.4 +/- 0.4 ns (solvent = butyronitrile, T = 77 K).

  3. Rational Design of Au@Pt Multibranched Nanostructures as Bifunctional Nanozymes.

    PubMed

    Wu, Jiangjiexing; Qin, Kang; Yuan, Dan; Tan, Jun; Qin, Li; Zhang, Xuejin; Wei, Hui

    2018-04-18

    One of the current challenges in nanozyme-based nanotechnology is the utilization of multifunctionalities in one material. In this regard, Au@Pt nanoparticles (NPs) with excellent enzyme-mimicking activities due to the Pt shell and unique surface plasmon resonance features from the Au core have attracted enormous research interest. However, the unique surface plasmon resonance features from the Au core have not been widely utilized. The practical problem of the optical-damping nature of Pt hinders the research into the combination of Au@Pt NPs' enzyme-mimicking properties with their surface-enhanced Raman scattering (SERS) activities. Herein, we rationally tuned the Pt amount to achieve Au@Pt NPs with simultaneous plasmonic and enzyme-mimicking activities. The results showed that Au@Pt NPs with 2.5% Pt produced the highest Raman signal in 2 min, which benefited from the remarkably accelerated catalytic oxidation of 3,3',5,5'-tetramethylbenzidine with the decorated Pt and strong electric field retained from the Au core for SERS. This study not only demonstrates the great promise of combining bimetallic nanomaterials' multiple functionalities but also provides rational guidelines to design high-performance nanozymes for potential biomedical applications.

  4. A facile approach for reducing the working voltage of Au/TiO2/Au nanostructured memristors by enhancing the local electric field

    NASA Astrophysics Data System (ADS)

    Arab Bafrani, Hamidreza; Ebrahimi, Mahdi; Bagheri Shouraki, Saeed; Moshfegh, Alireza Z.

    2018-01-01

    Memristor devices have attracted tremendous interest due to different applications ranging from nonvolatile data storage to neuromorphic computing units. Exploring the role of surface roughness of the bottom electrode (BE)/active layer interface provides useful guidelines for the optimization of the memristor switching performance. This study focuses on the effect of surface roughness of the BE electrode on the switching characteristics of Au/TiO2/Au three-layer memristor devices. An optimized wet-etching treatment condition was found to modify the surface roughness of the Au BE where the measurement results indicate that the roughness of the Au BE is affected by both duration time and solution concentrations of the wet-etching process. Then we fabricated arrays of TiO2-based nanostructured memristors sandwiched between two sets of cross-bar Au electrode lines (junction area 900 μm2). The results revealed a reduction in the working voltages in current-voltage characteristic of the device performance when increasing the surface roughness at the Au(BE)/TiO2 active layer interface. The set voltage of the device (Vset) significantly decreased from 2.26-1.93 V when we increased the interface roughness from 4.2-13.1 nm. The present work provides information for better understanding the switching mechanism of titanium-dioxide-based devices, and it can be inferred that enhancing the roughness of the Au BE/TiO2 active layer interface leads to a localized non-uniform electric field distribution that plays a vital role in reducing the energy consumption of the device.

  5. Cross-modal face recognition using multi-matcher face scores

    NASA Astrophysics Data System (ADS)

    Zheng, Yufeng; Blasch, Erik

    2015-05-01

    The performance of face recognition can be improved using information fusion of multimodal images and/or multiple algorithms. When multimodal face images are available, cross-modal recognition is meaningful for security and surveillance applications. For example, a probe face is a thermal image (especially at nighttime), while only visible face images are available in the gallery database. Matching a thermal probe face onto the visible gallery faces requires crossmodal matching approaches. A few such studies were implemented in facial feature space with medium recognition performance. In this paper, we propose a cross-modal recognition approach, where multimodal faces are cross-matched in feature space and the recognition performance is enhanced with stereo fusion at image, feature and/or score level. In the proposed scenario, there are two cameras for stereo imaging, two face imagers (visible and thermal images) in each camera, and three recognition algorithms (circular Gaussian filter, face pattern byte, linear discriminant analysis). A score vector is formed with three cross-matched face scores from the aforementioned three algorithms. A classifier (e.g., k-nearest neighbor, support vector machine, binomial logical regression [BLR]) is trained then tested with the score vectors by using 10-fold cross validations. The proposed approach was validated with a multispectral stereo face dataset from 105 subjects. Our experiments show very promising results: ACR (accuracy rate) = 97.84%, FAR (false accept rate) = 0.84% when cross-matching the fused thermal faces onto the fused visible faces by using three face scores and the BLR classifier.

  6. Meta-analytic review of the development of face discrimination in infancy: Face race, face gender, infant age, and methodology moderate face discrimination.

    PubMed

    Sugden, Nicole A; Marquis, Alexandra R

    2017-11-01

    Infants show facility for discriminating between individual faces within hours of birth. Over the first year of life, infants' face discrimination shows continued improvement with familiar face types, such as own-race faces, but not with unfamiliar face types, like other-race faces. The goal of this meta-analytic review is to provide an effect size for infants' face discrimination ability overall, with own-race faces, and with other-race faces within the first year of life, how this differs with age, and how it is influenced by task methodology. Inclusion criteria were (a) infant participants aged 0 to 12 months, (b) completing a human own- or other-race face discrimination task, (c) with discrimination being determined by infant looking. Our analysis included 30 works (165 samples, 1,926 participants participated in 2,623 tasks). The effect size for infants' face discrimination was small, 6.53% greater than chance (i.e., equal looking to the novel and familiar). There was a significant difference in discrimination by race, overall (own-race, 8.18%; other-race, 3.18%) and between ages (own-race: 0- to 4.5-month-olds, 7.32%; 5- to 7.5-month-olds, 9.17%; and 8- to 12-month-olds, 7.68%; other-race: 0- to 4.5-month-olds, 6.12%; 5- to 7.5-month-olds, 3.70%; and 8- to 12-month-olds, 2.79%). Multilevel linear (mixed-effects) models were used to predict face discrimination; infants' capacity to discriminate faces is sensitive to face characteristics including race, gender, and emotion as well as the methods used, including task timing, coding method, and visual angle. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Faciotopy—A face-feature map with face-like topology in the human occipital face area

    PubMed Central

    Henriksson, Linda; Mur, Marieke; Kriegeskorte, Nikolaus

    2015-01-01

    The occipital face area (OFA) and fusiform face area (FFA) are brain regions thought to be specialized for face perception. However, their intrinsic functional organization and status as cortical areas with well-defined boundaries remains unclear. Here we test these regions for “faciotopy”, a particular hypothesis about their intrinsic functional organisation. A faciotopic area would contain a face-feature map on the cortical surface, where cortical patches represent face features and neighbouring patches represent features that are physically neighbouring in a face. The faciotopy hypothesis is motivated by the idea that face regions might develop from a retinotopic protomap and acquire their selectivity for face features through natural visual experience. Faces have a prototypical configuration of features, are usually perceived in a canonical upright orientation, and are frequently fixated in particular locations. To test the faciotopy hypothesis, we presented images of isolated face features at fixation to subjects during functional magnetic resonance imaging. The responses in V1 were best explained by low-level image properties of the stimuli. OFA, and to a lesser degree FFA, showed evidence for faciotopic organization. When a single patch of cortex was estimated for each face feature, the cortical distances between the feature patches reflected the physical distance between the features in a face. Faciotopy would be the first example, to our knowledge, of a cortical map reflecting the topology, not of a part of the organism itself (its retina in retinotopy, its body in somatotopy), but of an external object of particular perceptual significance. PMID:26235800

  8. Faciotopy-A face-feature map with face-like topology in the human occipital face area.

    PubMed

    Henriksson, Linda; Mur, Marieke; Kriegeskorte, Nikolaus

    2015-11-01

    The occipital face area (OFA) and fusiform face area (FFA) are brain regions thought to be specialized for face perception. However, their intrinsic functional organization and status as cortical areas with well-defined boundaries remains unclear. Here we test these regions for "faciotopy", a particular hypothesis about their intrinsic functional organisation. A faciotopic area would contain a face-feature map on the cortical surface, where cortical patches represent face features and neighbouring patches represent features that are physically neighbouring in a face. The faciotopy hypothesis is motivated by the idea that face regions might develop from a retinotopic protomap and acquire their selectivity for face features through natural visual experience. Faces have a prototypical configuration of features, are usually perceived in a canonical upright orientation, and are frequently fixated in particular locations. To test the faciotopy hypothesis, we presented images of isolated face features at fixation to subjects during functional magnetic resonance imaging. The responses in V1 were best explained by low-level image properties of the stimuli. OFA, and to a lesser degree FFA, showed evidence for faciotopic organization. When a single patch of cortex was estimated for each face feature, the cortical distances between the feature patches reflected the physical distance between the features in a face. Faciotopy would be the first example, to our knowledge, of a cortical map reflecting the topology, not of a part of the organism itself (its retina in retinotopy, its body in somatotopy), but of an external object of particular perceptual significance. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Emotional Expression and Heart Rate in High-Risk Infants during the Face-To-Face/Still-Face

    PubMed Central

    Mattson, Whitney I.; Ekas, Naomi V.; Lambert, Brittany; Tronick, Ed; Lester, Barry M.; Messinger, Daniel S.

    2013-01-01

    In infants, eye constriction—the Duchenne marker—and mouth opening appear to index the intensity of both positive and negative facial expressions. We combined eye constriction and mouth opening that co-occurred with smiles and cry-faces (respectively, the prototypic expressions of infant joy and distress) to measure emotional expression intensity. Expression intensity and heart rate were measured throughout the Face-to-Face/Still Face (FFSF) in a sample of infants with prenatal cocaine exposure who were at risk for developmental difficulties. Smiles declined and cry-faces increased in the still-face episode, but the distribution of eye constriction and mouth opening in smiles and cry-faces did not differ across episodes of the FFSF. As time elapsed in the still face episode potential indices of intensity increased, cry-faces were more likely to be accompanied by eye constriction and mouth opening. During cry-faces there were also moderately stable individual differences in the quantity of eye constriction and mouth opening. Infant heart rate was higher during cry-faces and lower during smiles, but did not vary with intensity of expression or by episode. In sum, infants express more intense negative affect as the still-face progresses, but do not show clear differences in expressive intensity between episodes of the FFSF. PMID:24095807

  10. Size control of Au NPs supported by pH operation

    NASA Astrophysics Data System (ADS)

    Ichiji, Masumi; Akiba, Hiroko; Hirasawa, Izumi

    2017-07-01

    Au NPs are expected to become useful functional particles, as particle gun used for plant gene transfer and also catalysts. We have studied PSD (particle size distribution) control of Au NPs by reduction crystallization. Previous study found out importance of seeds policy and also feeding profile. In this paper, effect of pH in the reduction crystallization was investigated to clarify the possibility of Au NPs PSD control by pH operation and also their growth process. Au NPs of size range 10-600 nm were obtained in single-jet system using ascorbic acid (AsA) as a reducing agent with adjusting pH of AsA. Au NPs are found to grow in the process of nucleation, agglomeration, agglomeration growth and surface growth. Au NPs tend to grow by agglomeration and become larger size in lower pH regions, and to grow only by surface growth and become smaller size in higher pH regions.

  11. Charged-particle multiplicity and pseudorapidity distributions measured with the PHOBOS detector in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultrarelativistic energies

    NASA Astrophysics Data System (ADS)

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Chetluru, V.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kotuła, J.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wadsworth, B.; Walters, P.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2011-02-01

    Pseudorapidity distributions of charged particles emitted in Au+Au, Cu+Cu, d+Au, and p+p collisions over a wide energy range have been measured using the PHOBOS detector at the BNL Relativistic Heavy-Ion Collider (RHIC). The centrality dependence of both the charged particle distributions and the multiplicity at midrapidity were measured. Pseudorapidity distributions of charged particles emitted with |η|<5.4, which account for between 95% and 99% of the total charged-particle emission associated with collision participants, are presented for different collision centralities. Both the midrapidity density dNch/dη and the total charged-particle multiplicity Nch are found to factorize into a product of independent functions of collision energy, sNN, and centrality given in terms of the number of nucleons participating in the collision, Npart. The total charged particle multiplicity, observed in these experiments and those at lower energies, assumes a linear dependence of (lnsNN)2 over the full range of collision energy of sNN=2.7-200 GeV.

  12. Voicing on Virtual and Face to Face Discussion

    ERIC Educational Resources Information Center

    Yamat, Hamidah

    2013-01-01

    This paper presents and discusses findings of a study conducted on pre-service teachers' experiences in virtual and face to face discussions. Technology has brought learning nowadays beyond the classroom context or time zone. The learning context and process no longer rely solely on face to face communications in the presence of a teacher.…

  13. Face to face with emotion: holistic face processing is modulated by emotional state.

    PubMed

    Curby, Kim M; Johnson, Kareem J; Tyson, Alyssa

    2012-01-01

    Negative emotions are linked with a local, rather than global, visual processing style, which may preferentially facilitate feature-based, relative to holistic, processing mechanisms. Because faces are typically processed holistically, and because social contexts are prime elicitors of emotions, we examined whether negative emotions decrease holistic processing of faces. We induced positive, negative, or neutral emotions via film clips and measured holistic processing before and after the induction: participants made judgements about cued parts of chimeric faces, and holistic processing was indexed by the interference caused by task-irrelevant face parts. Emotional state significantly modulated face-processing style, with the negative emotion induction leading to decreased holistic processing. Furthermore, self-reported change in emotional state correlated with changes in holistic processing. These results contrast with general assumptions that holistic processing of faces is automatic and immune to outside influences, and they illustrate emotion's power to modulate socially relevant aspects of visual perception.

  14. Azimuthally sensitive hanbury brown-twiss interferometry in Au + Au collisions sqrt S sub NN = 200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adams, J.; Adler, C.; Aggarwal, M.M.

    2004-06-30

    We present the results of a systematic study of the shape of the pion distribution in coordinate space at freeze-out in Au+Au collisions at RHIC using two-pion Hanbury Brown-Twiss (HBT) interferometry. Oscillations of the extracted HBT radii vs. emission angle indicate sources elongated perpendicular to the reaction plane. The results indicate that the pressure and expansion time of the collision system are not sufficient to completely quench its initial shape.

  15. Pseudomorphic to orthomorphic growth of Fe films on Cu3Au(001)

    NASA Astrophysics Data System (ADS)

    Bruno, F.; Terreni, S.; Floreano, L.; Cossaro, A.; Cvetko, D.; Luches, P.; Mattera, L.; Morgante, A.; Moroni, R.; Repetto, M.; Verdini, A.; Canepa, M.

    2002-06-01

    The structure of Fe films grown on the (001) surface of a Cu3Au single crystal at room temperature has been investigated by means of grazing incidence x-ray diffraction (GIXRD) and photo/Auger-electron diffraction (ED) as a function of thickness in the (3-36)-Å range. The combination of GIXRD and ED allows one to obtain quantitative information on the in-plane spacing a from the former technique, and the ratio between the vertical spacing c and a, from the latter one. At low coverage the film grows pseudomorphic to the face-centered-cubic substrate. The experimental results obtained on a film of 8 Å thickness clearly indicate the overcoming of the limit for pseudomorphic growth. Above this limit the film is characterized by the coexistence of the pseudomorphic phase with another tetragonally strained phase γ, which falls on the epitaxial line of ferromagnetic face-centered cubic Fe. Finally, the development of a body-centered phase α, whose unit cell is rotated by 45° with respect to the substrate one, has been clearly observed at ~17 Å. α is the dominating phase for film thickness above ~25 Å and its lattice constant evolves towards the orthomorphic phase in strict quantitative agreement with epitaxial curves calculated for body-centered tetragonal iron phases.

  16. Learning Compact Binary Face Descriptor for Face Recognition.

    PubMed

    Lu, Jiwen; Liong, Venice Erin; Zhou, Xiuzhuang; Zhou, Jie

    2015-10-01

    Binary feature descriptors such as local binary patterns (LBP) and its variations have been widely used in many face recognition systems due to their excellent robustness and strong discriminative power. However, most existing binary face descriptors are hand-crafted, which require strong prior knowledge to engineer them by hand. In this paper, we propose a compact binary face descriptor (CBFD) feature learning method for face representation and recognition. Given each face image, we first extract pixel difference vectors (PDVs) in local patches by computing the difference between each pixel and its neighboring pixels. Then, we learn a feature mapping to project these pixel difference vectors into low-dimensional binary vectors in an unsupervised manner, where 1) the variance of all binary codes in the training set is maximized, 2) the loss between the original real-valued codes and the learned binary codes is minimized, and 3) binary codes evenly distribute at each learned bin, so that the redundancy information in PDVs is removed and compact binary codes are obtained. Lastly, we cluster and pool these binary codes into a histogram feature as the final representation for each face image. Moreover, we propose a coupled CBFD (C-CBFD) method by reducing the modality gap of heterogeneous faces at the feature level to make our method applicable to heterogeneous face recognition. Extensive experimental results on five widely used face datasets show that our methods outperform state-of-the-art face descriptors.

  17. The rational design of a Au(I) precursor for focused electron beam induced deposition.

    PubMed

    Marashdeh, Ali; Tiesma, Thiadrik; van Velzen, Niels J C; Harder, Sjoerd; Havenith, Remco W A; De Hosson, Jeff T M; van Dorp, Willem F

    2017-01-01

    Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition. Aurophilic interactions are found to play a key role. The short lifetime of ClAuCO in vacuum is explained by strong, destabilizing Au-Au interactions in the solid phase. While aurophilic interactions do not affect the stability of ClAuPMe 3 , they leave the complex non-volatile. Comparison of crystal structures of ClAuPMe 3 and MeAuPMe 3 shows that Au-Au interactions are much weaker or partially even absent for the latter structure. This explains its high volatility. However, MeAuPMe 3 dissociates unfavorably during FEBIP, making it an unsuitable precursor. The study shows that Me groups reduce aurophilic interactions, compared to Cl groups, which we attribute to electronic rather than steric effects. Therefore we propose MeAuCO as a potential FEBIP precursor. It is expected to have weak Au-Au interactions, making it volatile. It is stable enough to act as a volatile source for Au deposition, being stabilized by 6.5 kcal/mol. Finally, MeAuCO is likely to dissociate in a single step to pure Au.

  18. Transport characteristics in Au/pentacene/Au diodes

    NASA Astrophysics Data System (ADS)

    Hayashi, Toshiaki; Naka, Akiyoshi; Hiroki, Masanobu; Yokota, Tomoyuki; Someya, Takao; Fujiwara, Akira

    2018-03-01

    We have used scanning and transmission electron microscopes (SEM and TEM) to study the structure of a pentacene thin film grown on a Au layer with and shown that it consists of randomly oriented amorphous pentacene clusters. We have also investigated the transport properties of amorphous pentacene in a metal-semiconductor-metal (MSM) diode structure and shown that the current is logarithmically proportional to the square root of the applied voltage, which indicates that transport occurs as the result of hopping between localized sites randomly distributed in space and energy.

  19. ITO/Au/ITO sandwich structure for near-infrared plasmonics.

    PubMed

    Fang, Xu; Mak, Chee Leung; Dai, Jiyan; Li, Kan; Ye, Hui; Leung, Chi Wah

    2014-09-24

    ITO/Au/ITO trilayers with varying gold spacer layer thicknesses were deposited on glass substrates by pulsed laser deposition. Transmission electron microscopy measurements demonstrated the continuous nature of the Au layer down to 2.4 nm. XRD patterns clearly showed an enhanced crystallinity of the ITO films promoted by the insertion of the gold layer. Compared with a single layer of ITO with a carrier concentration of 7.12 × 10(20) cm(-3), the ITO/Au/ITO structure achieved an effective carrier concentration as high as 3.26 × 10(22) cm(-3). Transmittance and ellipsometry measurements showed that the optical properties of ITO/Au/ITO films were greatly influenced by the thickness of the inserted gold layer. The cross-point wavelength of the trilayer samples was reduced with increasing gold layer thickness. Importantly, the trilayer structure exhibited a reduced loss (compared with plain Au) in the near-infrared region, suggesting its potential for plasmonic applications in the near-infrared range.

  20. Synthesis, characterization, and electrochemical behavior of Au@Pd core shell nanoparticles

    NASA Astrophysics Data System (ADS)

    Wicaksono, W. P.; Ivandini, T. A.

    2017-04-01

    Au@Pd core shell nanoparticles (Au@Pd CSNPs) were successfully synthesized using a seed-mediated growth method. Firstly, a pale pink gold seed solution was used to produce a pale purple gold nanoparticles (AuNPs) core solution. Then, three series of Pd shell thickness using 20μ, 100 μL, and 500 μL of PdCl2 produced purple, brown, and deep brown of Au@Pd CSNPs respectively. A strong absorbance UV-Visible spectrum with peaks at 285 nm and 535 nm was identified for AuNPs formation. The disappearance of the peak at 535 nm was indicated the Au@Pd CSNPs formation. The electrochemical properties were examined in phosphate buffer pH 7 using cyclic voltammetry technique with boron-doped diamond (BDD) as working electrode showed a couple oxidation and reduction peak of gold at 0.67 V and at 0.33 V, respectively. The Au@Pd CNPs will be used for modification of BDD electrodes.

  1. Formation of alternating interfacial layers in Au-12Ge/Ni joints

    PubMed Central

    Lin, Shih-kang; Tsai, Ming-yueh; Tsai, Ping-chun; Hsu, Bo-hsun

    2014-01-01

    Au-Ge alloys are promising materials for high-power and high-frequency packaging, and Ni is frequently used as diffusion barriers. This study investigates interfacial reactions in Au-12Ge/Ni joints at 300°C and 400°C. For the reactions at 300°C, typical interfacial morphology was observed and the diffusion path was (Au) + (Ge)/NiGe/Ni5Ge3/Ni. However, an interesting phenomenon – the formation of (Au,Ni,Ge)/NiGe alternating layers – was observed for the reactions at 400°C. The diffusion path across the interface was liquid/(Au,Ni,Ge)/NiGe/···/(Au,Ni,Ge)/NiGe/Ni2Ge/Ni. The periodic thermodynamic instability at the NiGe/Ni2Ge interface caused the subsequent nucleation of new (Au,Ni,Ge)/NiGe pairs. The thermodynamic foundation and mechanism of formation of the alternating layers are elaborated in this paper. PMID:24690992

  2. Azimuthal anisotophy in U + U and Au + Au collisions at RHIC

    DOE PAGES

    Adamczyk, L.

    2015-11-24

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v 2{2} and v 2{4}, for charged hadrons from U+U collisions at √ SNN = 193 GeV and Au+Au collisions at √ SNN = 200 GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v 2{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions.more » As a result, we also show that v 2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.« less

  3. High Transverse Momentum Triggered Correlations over a Large Pseudorapidity Acceptance in Au+Au Collisions at sNN=200GeV

    NASA Astrophysics Data System (ADS)

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Chetluru, V.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

    2010-02-01

    A measurement of two-particle correlations with a high transverse momentum trigger particle (pTtrig>2.5GeV/c) is presented for Au+Au collisions at sNN=200GeV over the uniquely broad longitudinal acceptance of the PHOBOS detector (-4<Δη<2). A broadening of the away-side azimuthal correlation compared to elementary collisions is observed at all Δη. As in p+p collisions, the near side is characterized by a peak of correlated partners at small angle relative to the trigger particle. However, in central Au+Au collisions an additional correlation extended in Δη and known as the “ridge” is found to reach at least |Δη|≈4. The ridge yield is largely independent of Δη over the measured range, and it decreases towards more peripheral collisions. For the chosen pTtrig cut, the ridge yield is consistent with zero for events with less than roughly 100 participating nucleons.

  4. Emotional expression and heart rate in high-risk infants during the face-to-face/still-face.

    PubMed

    Mattson, Whitney I; Ekas, Naomi V; Lambert, Brittany; Tronick, Ed; Lester, Barry M; Messinger, Daniel S

    2013-12-01

    In infants, eye constriction-the Duchenne marker-and mouth opening appear to index the intensity of both positive and negative facial expressions. We combined eye constriction and mouth opening that co-occurred with smiles and cry-faces (respectively, the prototypic expressions of infant joy and distress) to measure emotional expression intensity. Expression intensity and heart rate were measured throughout the face-to-face/still-face (FFSF) in a sample of infants with prenatal cocaine exposure who were at risk for developmental difficulties. Smiles declined and cry-faces increased in the still-face episode, but the distribution of eye constriction and mouth opening in smiles and cry-faces did not differ across episodes of the FFSF. As time elapsed in the still face episode potential indices of intensity increased, cry-faces were more likely to be accompanied by eye constriction and mouth opening. During cry-faces there were also moderately stable individual differences in the quantity of eye constriction and mouth opening. Infant heart rate was higher during cry-faces and lower during smiles, but did not vary with intensity of expression or by episode. In sum, infants express more intense negative affect as the still-face progresses, but do not show clear differences in expressive intensity between episodes of the FFSF. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Face-n-Food: Gender Differences in Tuning to Faces.

    PubMed

    Pavlova, Marina A; Scheffler, Klaus; Sokolov, Alexander N

    2015-01-01

    Faces represent valuable signals for social cognition and non-verbal communication. A wealth of research indicates that women tend to excel in recognition of facial expressions. However, it remains unclear whether females are better tuned to faces. We presented healthy adult females and males with a set of newly created food-plate images resembling faces (slightly bordering on the Giuseppe Arcimboldo style). In a spontaneous recognition task, participants were shown a set of images in a predetermined order from the least to most resembling a face. Females not only more readily recognized the images as a face (they reported resembling a face on images, on which males still did not), but gave on overall more face responses. The findings are discussed in the light of gender differences in deficient face perception. As most neuropsychiatric, neurodevelopmental and psychosomatic disorders characterized by social brain abnormalities are sex specific, the task may serve as a valuable tool for uncovering impairments in visual face processing.

  6. Face-n-Food: Gender Differences in Tuning to Faces

    PubMed Central

    Pavlova, Marina A.; Scheffler, Klaus; Sokolov, Alexander N.

    2015-01-01

    Faces represent valuable signals for social cognition and non-verbal communication. A wealth of research indicates that women tend to excel in recognition of facial expressions. However, it remains unclear whether females are better tuned to faces. We presented healthy adult females and males with a set of newly created food-plate images resembling faces (slightly bordering on the Giuseppe Arcimboldo style). In a spontaneous recognition task, participants were shown a set of images in a predetermined order from the least to most resembling a face. Females not only more readily recognized the images as a face (they reported resembling a face on images, on which males still did not), but gave on overall more face responses. The findings are discussed in the light of gender differences in deficient face perception. As most neuropsychiatric, neurodevelopmental and psychosomatic disorders characterized by social brain abnormalities are sex specific, the task may serve as a valuable tool for uncovering impairments in visual face processing. PMID:26154177

  7. Self-decorated Au nanoparticles on antireflective Si pyramids with improved hydrophobicity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saini, C. P.; Barman, A.; Kanjilal, A., E-mail: aloke.kanjilal@snu.edu.in

    2016-04-07

    Post-deposition annealing mediated evolution of self-decorated Au nanoparticles (NPs) on chemically etched Si pyramids is presented. A distinct transformation of Si surfaces from hydrophilic to hydrophobic is initially found after chemical texturing, showing an increase in contact angle (CA) from 58° to 98° (±1°). Further improvement of hydrophobicity with CA up to ∼118° has been established after annealing a 10 nm thick Au-coated Si pyramids at 400 °C that led to the formation of Au NPs on Si facets along with self-ordering at the pyramid edges. Detailed x-ray diffraction studies suggest the evolution of crystalline Au NPs on strained Si facets. Microstructuralmore » studies, however, indicate no mixing of Au and Si atoms at the Au/Si interfaces, instead of forming Au nanocrystals at 400 °C. The improved hydrophobicity of Si pyramids, even with Au NPs can be explained in the light of a decrease in solid fractional surface area according to Wenzel's model. Moreover, a sharp drop in specular reflectance from Si pyramids in the range of 300–800 nm, especially in the ultraviolet region up to ∼0.4% is recorded in the presence of Au NPs by ultraviolet-visible spectroscopy, reflecting the possible use in photovoltaic devices with improved antireflection property.« less

  8. Highly narrow nanogap-containing Au@Au core-shell SERS nanoparticles: size-dependent Raman enhancement and applications in cancer cell imaging

    NASA Astrophysics Data System (ADS)

    Hu, Chongya; Shen, Jianlei; Yan, Juan; Zhong, Jian; Qin, Weiwei; Liu, Rui; Aldalbahi, Ali; Zuo, Xiaolei; Song, Shiping; Fan, Chunhai; He, Dannong

    2016-01-01

    Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on the surface of cancer cells. First, plasmonic nanostructures are made of gold nanoparticles (~15 nm) coated with gold shells, between which a highly narrow and uniform nanogap (~1.1 nm) is formed owing to polyA anchored on the Au cores. The well controlled distribution of Raman reporter molecules, such as 4,4'-dipyridyl (44DP) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), are readily encoded in the nanogap and can generate strong, reproducible SERS signals. In addition, we have investigated the size-dependent SERS activity of GCNPs and found that with the same laser wavelength, the Raman enhancement discriminated between particle sizes. The maximum Raman enhancement was achieved at a certain threshold of particle size (~76 nm). High narrow nanogap-containing Au@Au core-shell SERS tags (GCTs) were prepared via the functionalization of hyaluronic acid (HA) on GCNPs, which recognized the CD44 receptor, a tumor-associated surface biomarker. And it was shown that GCTs have a good targeting ability to tumour cells and promising prospects for multiplex biomarker detection.Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on

  9. Corrosion resistance evaluation of Pd-free Ag-Au-Pt-Cu dental alloys.

    PubMed

    Fujita, Takeshi; Shiraishi, Takanobu; Takuma, Yasuko; Hisatsune, Kunihiro

    2011-01-01

    The corrosion resistance of nine experimental Pd-free Ag-Au-Pt-Cu dental alloys in a 0.9% NaCl solution was investigated using cyclic voltammetry (CV), optical microscopy, and scanning electron microscopy (SEM). CV measurements revealed that the breakdown potential (E(bd)) and zero current potential (E(zc)) increased with increasing Au/(Au+Ag) atomic ratio. Thus, the Au/(Au+Ag) atomic ratio, but not the Cu content, influenced the corrosion resistance of Ag-Au-Pt-Cu alloys. After the forward scan of CV, both optical and scanning electron microscope images showed that in all the experimental alloys, the matrix phase was corroded but not the second phase. From corrosion resistance viewpoint, the Ag-Au-Pt-Cu alloys seemed to be suitable for clinical application.

  10. Novel Au-TiC Catalysts for CO Oxidation and Desulfurization Processes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rodriguez, J.A.; Liu, P.; Takahashi, Y.

    2011-05-30

    Recent articles dealing with the physical and chemical properties of novel Au-TiC catalysts are reviewed. High-resolution photoemission, scanning tunneling microscopy and first-principles periodic density-functional calculations were used to study the deposition of gold on a TiC(0 0 1) surface. Gold grows forming two-dimensional (very low coverage) and three-dimensional (medium and large coverage) islands on the carbide substrate. A positive shift in the binding energy of the C 1s core level is observed after the deposition of Au on TiC(0 0 1). The results of the density-functional calculations corroborate the formation of Au-C bonds. In general, the bond between Au andmore » the TiC(0 0 1) surface exhibits very little ionic character, but there is a substantial polarization of electrons around Au that facilitates bonding of the adatoms with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). Experimental measurements indicate that Au/TiC(0 0 1) is a very good catalysts for the oxidation of CO, the destruction of SO{sub 2} and the hydrodesulfurization of thiophene. At temperatures below 200 K, Au/TiC(0 0 1) is able to perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction and the full decomposition of SO{sub 2}. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(0 0 1) or Au(1 1 1), a Au/TiC(0 0 1) surface displays a hydrodesulfurization activity higher than that of conventional Ni/MoS{sub x} catalysts. Metal carbides are excellent supports for enhancing the chemical reactivity of gold. The Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces.« less

  11. Novel Au-TiC Catalysts for CO Oxidation and Desulfurization Processes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    J Rodriguez; P Liu; Y Takahashi

    2011-12-31

    Recent articles dealing with the physical and chemical properties of novel Au-TiC catalysts are reviewed. High-resolution photoemission, scanning tunneling microscopy and first-principles periodic density-functional calculations were used to study the deposition of gold on a TiC(0 0 1) surface. Gold grows forming two-dimensional (very low coverage) and three-dimensional (medium and large coverage) islands on the carbide substrate. A positive shift in the binding energy of the C 1s core level is observed after the deposition of Au on TiC(0 0 1). The results of the density-functional calculations corroborate the formation of Au-C bonds. In general, the bond between Au andmore » the TiC(0 0 1) surface exhibits very little ionic character, but there is a substantial polarization of electrons around Au that facilitates bonding of the adatoms with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). Experimental measurements indicate that Au/TiC(0 0 1) is a very good catalysts for the oxidation of CO, the destruction of SO{sub 2} and the hydrodesulfurization of thiophene. At temperatures below 200 K, Au/TiC(0 0 1) is able to perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction and the full decomposition of SO{sub 2}. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(0 0 1) or Au(1 1 1), a Au/TiC(0 0 1) surface displays a hydrodesulfurization activity higher than that of conventional Ni/MoS{sub x} catalysts. Metal carbides are excellent supports for enhancing the chemical reactivity of gold. The Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces.« less

  12. Homoepitaxial electrodeposition on reconstructed and unreconstructed Au(100): An in-situ STM study

    NASA Astrophysics Data System (ADS)

    Al-Shakran, Mohammad; Kibler, Ludwig A.; Jacob, Timo

    2015-01-01

    A study of homoepitaxial electrodeposition on reconstructed and unreconstructed Au(100) surfaces is presented. The growth behavior has been investigated by in-situ scanning tunneling microscopy for Au(100) in contact with 0.1 M H2SO4 + 5 μM K[AuCl4]. It is shown that the initial surface structure is decisive for the emerging Au structures, giving rise to clearly different surface morphologies for electro-crystallization of Au on the unreconstructed and on the reconstructed Au(100) surface. A layer-by-layer growth is observed at more positive potentials for unreconstructed Au(100). The electrodeposition proceeds initially by the formation of Au islands followed by island coalescence due to the high mobility of surface atoms. Monatomic recessed stripes are formed as a result of the coalescence of deposited Au islands. At more negative potentials, the growth of Au proceeds strongly anisotropic on the reconstructed surface by the formation of reconstructed elongated islands.

  13. Single electron yields from semileptonic charm and bottom hadron decays in Au +Au collisions at √{sN N}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alexander, J.; Alfred, M.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Black, D.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Cronin, N.; Crossette, N.; Csanád, M.; Csörgő, T.; Dairaku, S.; Danley, T. W.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Ding, L.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Hayano, R.; Hayashi, S.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imazu, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Isinhue, A.; Ivanishchev, D.; Jacak, B. V.; Javani, M.; Jezghani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kamin, J.; Kanda, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, G. W.; Kim, M.; Kim, Y.-J.; Kim, Y. K.; Kimelman, B.; Kinney, E.; Kistenev, E.; Kitamura, R.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Krizek, F.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Li, X.; Lim, S. H.; Linden Levy, L. A.; Liu, M. X.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Maruyama, T.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Midori, J.; Mignerey, A. C.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Mohapatra, S.; Montuenga, P.; Moon, H. J.; Moon, T.; Morrison, D. P.; Moskowitz, M.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagashima, K.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Netrakanti, P. K.; Nihashi, M.; Niida, T.; Nishimura, S.; Nouicer, R.; Novák, T.; Novitzky, N.; Nukariya, A.; Nyanin, A. S.; Obayashi, H.; O'Brien, E.; Ogilvie, C. A.; Okada, K.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J. S.; Park, S.; Park, S. K.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Purschke, M. L.; Qu, H.; Rak, J.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, S.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Slunečka, M.; Snowball, M.; Solano, S.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Torii, H.; Towell, C. L.; Towell, R.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Voas, B.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Whitaker, S.; White, A. S.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Xia, B.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoon, I.; You, Z.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zhou, S.; Zou, L.; Phenix Collaboration

    2016-03-01

    The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy flavor production in minimum bias Au +Au collisions at √{sN N}=200 GeV via the yields of electrons from semileptonic decays of charm and bottom hadrons. Previous heavy flavor electron measurements indicated substantial modification in the momentum distribution of the parent heavy quarks owing to the quark-gluon plasma created in these collisions. For the first time, using the PHENIX silicon vertex detector to measure precision displaced tracking, the relative contributions from charm and bottom hadrons to these electrons as a function of transverse momentum are measured in Au +Au collisions. We compare the fraction of electrons from bottom hadrons to previously published results extracted from electron-hadron correlations in p +p collisions at √{sN N}=200 GeV and find the fractions to be similar within the large uncertainties on both measurements for pT>4 GeV/c . We use the bottom electron fractions in Au +Au and p +p along with the previously measured heavy flavor electron RA A to calculate the RA A for electrons from charm and bottom hadron decays separately. We find that electrons from bottom hadron decays are less suppressed than those from charm for the region 3

  14. Port-au-Prince, Haiti

    NASA Image and Video Library

    2010-01-14

    This image, produced from instrument data aboard NASA Space Shuttle Endeavour, is a perspective view of the topography of Port-au-Prince, Haiti where a magnitude 7.0 earthquake occurred on January 12, 2010.

  15. The Caledonian face test: A new test of face discrimination.

    PubMed

    Logan, Andrew J; Wilkinson, Frances; Wilson, Hugh R; Gordon, Gael E; Loffler, Gunter

    2016-02-01

    This study aimed to develop a clinical test of face perception which is applicable to a wide range of patients and can capture normal variability. The Caledonian face test utilises synthetic faces which combine simplicity with sufficient realism to permit individual identification. Face discrimination thresholds (i.e. minimum difference between faces required for accurate discrimination) were determined in an "odd-one-out" task. The difference between faces was controlled by an adaptive QUEST procedure. A broad range of face discrimination sensitivity was determined from a group (N=52) of young adults (mean 5.75%; SD 1.18; range 3.33-8.84%). The test is fast (3-4 min), repeatable (test-re-test r(2)=0.795) and demonstrates a significant inversion effect. The potential to identify impairments of face discrimination was evaluated by testing LM who reported a lifelong difficulty with face perception. While LM's impairment for two established face tests was close to the criterion for significance (Z-scores of -2.20 and -2.27) for the Caledonian face test, her Z-score was -7.26, implying a more than threefold higher sensitivity. The new face test provides a quantifiable and repeatable assessment of face discrimination ability. The enhanced sensitivity suggests that the Caledonian face test may be capable of detecting more subtle impairments of face perception than available tests. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Face-Lift Satisfaction Using the FACE-Q.

    PubMed

    Sinno, Sammy; Schwitzer, Jonathan; Anzai, Lavinia; Thorne, Charles H

    2015-08-01

    Face lifting is one of the most common operative procedures for facial aging and perhaps the procedure most synonymous with plastic surgery in the minds of the lay public, but no verifiable documentation of patient satisfaction exists in the literature. This study is the first to examine face-lift outcomes and patient satisfaction using a validated questionnaire. One hundred five patients undergoing a face lift performed by the senior author (C.H.T.) using a high, extended-superficial musculoaponeurotic system with submental platysma approximation technique were asked to complete anonymously the FACE-Q by e-mail. FACE-Q scores were assessed for each domain (range, 0 to 100), with higher scores indicating greater satisfaction with appearance or superior quality of life. Fifty-three patients completed the FACE-Q (50.5 percent response rate). Patients demonstrated high satisfaction with facial appearance (mean ± SD, 80.7 ± 22.3), and quality of life, including social confidence (90.4 ± 16.6), psychological well-being (92.8 ± 14.3), and early life impact (92.2 ± 16.4). Patients also reported extremely high satisfaction with their decision to undergo face lifting (90.5 ± 15.9). On average, patients felt they appeared 6.9 years younger than their actual age. Patients were most satisfied with the appearance of their nasolabial folds (86.2 ± 18.5), cheeks (86.1 ± 25.4), and lower face/jawline (86.0 ± 20.6), compared with their necks (78.1 ± 25.6) and area under the chin (67.9 ± 32.3). Patients who responded in this study were extremely satisfied with their decision to undergo face lifting and the outcomes and quality of life following the procedure.

  17. A Face Inversion Effect without a Face

    ERIC Educational Resources Information Center

    Brandman, Talia; Yovel, Galit

    2012-01-01

    Numerous studies have attributed the face inversion effect (FIE) to configural processing of internal facial features in upright but not inverted faces. Recent findings suggest that face mechanisms can be activated by faceless stimuli presented in the context of a body. Here we asked whether faceless stimuli with or without body context may induce…

  18. Radiotherapy Improvements by Using Au Nanoparticles.

    PubMed

    Torrisi, Lorenzo

    2015-01-01

    Au nanoparticles can be prepared inside biological solutions and incorporated in special molecules for their transport through blood, drugs and proteins up to the tumour sites or directly injected in their volume when it is possible. The Au nanoparticles are biocompatible and can be accepted locally in the organism also at relatively high concentrations. The use of Au nanoparticles injected in the tumour site enhances significantly the effective atomic number of the medium, depending on the used concentration, and consequently the proton and electron energy loss and the X-ray absorption coefficient determining an increment of the local absorbed dose during radiotherapy. Traditional radiotherapy using electrons, X-rays and gamma rays, and innovative protontherapy can benefit the increment of the effective atomic number of the tissue in the presence of Au-nanoparticles embedded in the tumour volume with an adaptive up-take procedure. This method decreases the dose released to the healthy tissues permitting a better cantering of the irradiated targets and shielding the healthy tissue placed behind the tumour. The presented theoretical study approach permits to evaluate an enhancement of the radiotherapy dose of the order of 1 % using 60 MeV protons, of the order of 10% using 6 MeV electrons and of the order of 100 % using 100 keV X-ray photons. Here, we also disccused for patents relaed to the topic.

  19. Plasmonic enhancement of visible-light water splitting with Au-TiO2 composite aerogels

    NASA Astrophysics Data System (ADS)

    Desario, Paul A.; Pietron, Jeremy J.; Devantier, Devyn E.; Brintlinger, Todd H.; Stroud, Rhonda M.; Rolison, Debra R.

    2013-08-01

    We demonstrate plasmonic enhancement of visible-light-driven splitting of water at three-dimensionally (3D) networked gold-titania (Au-TiO2) aerogels. The sol-gel-derived ultraporous composite nanoarchitecture, which contains 1 to 8.5 wt% Au nanoparticles and titania in the anatase form, retains the high surface area and mesoporosity of unmodified TiO2 aerogels and maintains stable dispersion of the ~5 nm Au guests. A broad surface plasmon resonance (SPR) feature centered at ~550 nm is present for the Au-TiO2 aerogels, but not Au-free TiO2 aerogels, and spans a wide range of the visible spectrum. Gold-derived SPR in Au-TiO2 aerogels cast as films on transparent electrodes drives photoelectrochemical oxidation of aqueous hydroxide and extends the photocatalytic activity of TiO2 from the ultraviolet region to visible wavelengths exceeding 700 nm. Films of Au-TiO2 aerogels in which Au nanoparticles are deposited on pre-formed TiO2 aerogels by a deposition-precipitation method (DP Au/TiO2) also photoelectrochemically oxidize aqueous hydroxide, but less efficiently than 3D Au-TiO2, despite having an essentially identical Au nanoparticle weight fraction and size distribution. For example, 3D Au-TiO2 containing 1 wt% Au is as active as DP Au/TiO2 with 4 wt% Au. The higher photocatalytic activity of 3D Au-TiO2 derives only in part from its ability to retain the surface area and porosity of unmodified TiO2 aerogel. The magnitude of improvement indicates that in the 3D arrangement either a more accessible photoelectrochemical reaction interphase (three-phase boundary) exists or more efficient conversion of excited surface plasmons into charge carriers occurs, thereby amplifying reactivity over DP Au/TiO2. The difference in photocatalytic efficiency between the two forms of Au-TiO2 demonstrates the importance of defining the structure of Au||TiO2 interfaces within catalytic Au-TiO2 nanoarchitectures.We demonstrate plasmonic enhancement of visible-light-driven splitting of

  20. Diabetic foot infections: recent literature and cornerstones of management.

    PubMed

    Uçkay, Ilker; Gariani, Karim; Dubois-Ferrière, Victor; Suvà, Domizio; Lipsky, Benjamin A

    2016-04-01

    Diabetes mellitus has reached pandemic levels and will continue to increase worldwide. Physicians and surgeons should know to manage one of its most prevalent complications, the diabetic foot infection (DFI), in a scientifically based and resource-sparing way. We performed a nonsystematic review of recent scientific literature to provide guidance on management of DFIs. Studies in the past couple of years provide data on which recommendations for diagnosing and treating DFI are based, especially with validated guidelines and reviews of the microbiology and selected aspects of the complex DFI problem. Recent literature provides approaches to prevention and studies support more conservative surgical treatment. Unfortunately, there have been virtually no new therapeutic molecules, antibiotic regimens, randomized trials, or surgical techniques introduced in the recent past; we briefly discuss how this may change in the future. Recent scientific evidence on DFI strongly supports the value of multidisciplinary and some new care models, guideline-based management, more preventive approaches, and confirms several established therapeutic concepts. In contrast, there has been almost no new substantial information regarding the optimal antibiotic or surgical management in recent literature.

  1. Staphylococcus aureus Toxins and Diabetic Foot Ulcers: Role in Pathogenesis and Interest in Diagnosis

    PubMed Central

    Dunyach-Remy, Catherine; Ngba Essebe, Christelle; Sotto, Albert; Lavigne, Jean-Philippe

    2016-01-01

    Infection of foot ulcers is a common, often severe and costly complication in diabetes. Diabetic foot infections (DFI) are mainly polymicrobial, and Staphylococcus aureus is the most frequent pathogen isolated. The numerous virulence factors and toxins produced by S. aureus during an infection are well characterized. However, some particular features could be observed in DFI. The aim of this review is to describe the role of S. aureus in DFI and the implication of its toxins in the establishment of the infection. Studies on this issue have helped to distinguish two S. aureus populations in DFI: toxinogenic S. aureus strains (harboring exfoliatin-, EDIN-, PVL- or TSST-encoding genes) and non-toxinogenic strains. Toxinogenic strains are often present in infections with a more severe grade and systemic impact, whereas non-toxinogenic strains seem to remain localized in deep structures and bone involving diabetic foot osteomyelitis. Testing the virulence profile of bacteria seems to be a promising way to predict the behavior of S. aureus in the chronic wounds. PMID:27399775

  2. Au-rich filamentary behavior and associated subband gap optical absorption in hyperdoped Si

    NASA Astrophysics Data System (ADS)

    Yang, W.; Akey, A. J.; Smillie, L. A.; Mailoa, J. P.; Johnson, B. C.; McCallum, J. C.; Macdonald, D.; Buonassisi, T.; Aziz, M. J.; Williams, J. S.

    2017-12-01

    Au-hyperdoped Si, synthesized by ion implantation and pulsed laser melting, is known to exhibit a strong sub-band gap photoresponse that scales monotonically with the Au concentration. However, there is thought to be a limit to this behavior since ultrahigh Au concentrations (>1 ×1020c m-3 ) are expected to induce cellular breakdown during the rapid resolidification of Si, a process that is associated with significant lateral impurity precipitation. This work shows that the cellular morphology observed in Au-hyperdoped Si differs from that in conventional, steady-state cellular breakdown. In particular, Rutherford backscattering spectrometry combined with channeling and transmission electron microscopy revealed an inhomogeneous Au distribution and a subsurface network of Au-rich filaments, within which the Au impurities largely reside on substitutional positions in the crystalline Si lattice, at concentrations as high as ˜3 at. %. The measured substitutional Au dose, regardless of the presence of Au-rich filaments, correlates strongly with the sub-band gap optical absorptance. Upon subsequent thermal treatment, the supersaturated Au forms precipitates, while the Au substitutionality and the sub-band gap optical absorption both decrease. These results offer insight into a metastable filamentary regime in Au-hyperdoped Si that has important implications for Si-based infrared optoelectronics.

  3. Structure of the Si(111)-(5×2)-Au Surface

    NASA Astrophysics Data System (ADS)

    Abukawa, Tadashi; Nishigaya, Yoshiki

    2013-01-01

    The structure of the Si(111)-(5×2)-Au surface, one of the long-standing problems in surface science, has been solved by means of Weissenberg reflection high-energy electron diffraction. The arrangement of the Au atoms and their positions with respect to the substrate were determined from a three-dimensional Patterson function with a lateral resolution of 0.3 Å based on a large amount of diffraction data. The new structural model consists of six Au atoms in a 5×2 unit, which agrees with the recently confirmed Au coverage of 0.6 ML [I. Barke , Phys. Rev. B 79, 155301 (2009).PRBMDO1098-0121]. The model has a distinct ×2 periodicity, and includes a Au dimer. The model is also compatible with previously obtained STM images.

  4. Alternative types of molecule-decorated atomic chains in Au-CO-Au single-molecule junctions.

    PubMed

    Balogh, Zoltán; Makk, Péter; Halbritter, András

    2015-01-01

    We investigate the formation and evolution of Au-CO single-molecule break junctions. The conductance histogram exhibits two distinct molecular configurations, which are further investigated by a combined statistical analysis. According to conditional histogram and correlation analysis these molecular configurations show strong anticorrelations with each other and with pure Au monoatomic junctions and atomic chains. We identify molecular precursor configurations with somewhat higher conductance, which are formed prior to single-molecule junctions. According to detailed length analysis two distinct types of molecule-affected chain-formation processes are observed, and we compare these results to former theoretical calculations considering bridge- and atop-type molecular configurations where the latter has reduced conductance due to destructive Fano interference.

  5. Direct observation of dijets in central Au+Au collisions at sqrt[sNN]=200 GeV.

    PubMed

    Adams, J; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Bezverkhny, B I; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, C O; Blyth, S-L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Choi, H A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; de Moura, M M; Dedovich, T G; Dephillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Guo, Y; Gupta, N; Gutierrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lapointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; Levine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van der Kolk, N; van Leeuwen, M; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2006-10-20

    The STAR Collaboration at the Relativistic Heavy Ion Collider reports measurements of azimuthal correlations of high transverse momentum (pT) charged hadrons in Au+Au collisions at higher pT than reported previously. As (pT) is increased, a narrow, back-to-back peak emerges above the decreasing background, providing a clear dijet signal for all collision centralities studied. Using these correlations, we perform a systematic study of dijet production and suppression in nuclear collisions, providing new constraints on the mechanisms underlying partonic energy loss in dense matter.

  6. Pion-Kaon correlations in central Au+Au collisions at square root [sNN] = 130 GeV.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gutierrez, T D; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2003-12-31

    Pion-kaon correlation functions are constructed from central Au+Au STAR data taken at sqrt[s(NN)]=130 GeV by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The results suggest that pions and kaons are not emitted at the same average space-time point. Space-momentum correlations, i.e., transverse flow, lead to a space-time emission asymmetry of pions and kaons that is consistent with the data. This result provides new independent evidence that the system created at RHIC undergoes a collective transverse expansion.

  7. Guazuma ulmifolia bark-synthesized Ag, Au and Ag/Au alloy nanoparticles: Photocatalytic potential, DNA/protein interactions, anticancer activity and toxicity against 14 species of microbial pathogens.

    PubMed

    Karthika, Viswanathan; Arumugam, Ayyakannu; Gopinath, Kasi; Kaleeswarran, Periyannan; Govindarajan, Marimuthu; Alharbi, Naiyf S; Kadaikunnan, Shine; Khaled, Jamal M; Benelli, Giovanni

    2017-02-01

    In the present study, we focused on a quick and green method to fabricate Ag, Au and Ag/Au alloy nanoparticles (NPs) using the bark extract of Guazuma ulmifolia L. Green synthesized metal NPs were characterized using different techniques, including UV-Vis spectroscopy, FT-IR, XRD, AFM and HR-TEM analyses. The production of Ag, Au and Ag/Au alloy NPs was observed monitoring color change from colorless to brown, followed by pink and dark brown, as confirmed by UV-Vis spectroscopy characteristic peaks at 436, 522 and 510nm, respectively. TEM shed light on the spherical shapes of NPs with size ranges of 10-15, 20-25 and 10-20nm. Biosynthesized NPs showed good catalytic activity reducing two organic dyes, 4-nitrophenol (4-NP) and Congo red (CR). UV-vis spectroscopy, fluorescence, circular dichroism spectroscopy and viscosity analyses were used to investigate the NP binding with calf thymus DNA. The binding constant of NPs with DNA calculated in UV-Vis absorption studies were 1.18×10 4 , 1.83×10 4 and 2.91×10 4 M -1 , respectively, indicating that NPs were able to bind DNA with variable binding affinity: Ag/Au alloy NPs>Ag NPs>Au NPs. Ag/Au alloy NPs also showed binding activity to bovine serum albumin (BSA) over the other NPs. Ag and Ag/Au alloy NPs exhibited good antimicrobial activity on 14 species of microbial pathogens. In addition, the cytotoxic effects of Ag/Au alloy NPs were studied on human cervical cancer cells (HeLa) using MTT assay. Overall, our work showed the promising potential of bark-synthesized Ag and Ag/Au alloy NPs as cheap sources to develop novel and safer photocatalytic, antimicrobial and anticancer agents. Copyright © 2017. Published by Elsevier B.V.

  8. Face to Face Communications in Space

    NASA Technical Reports Server (NTRS)

    Cohen, Malcolm M.; Davon, Bonnie P. (Technical Monitor)

    1999-01-01

    It has been reported that human face-to-face communications in space are compromised by facial edema, variations in the orientations of speakers and listeners, and background noises that are encountered in the shuttle and in space stations. To date, nearly all reports have been anecdotal or subjective, in the form of post-flight interviews or questionnaires; objective and quantitative data are generally lacking. Although it is acknowledged that efficient face-to-face communications are essential for astronauts to work safely and effectively, specific ways in which the space environment interferes with non-linguistic communication cues are poorly documented. Because we have only a partial understanding of how non-linguistic communication cues may change with mission duration, it is critically important to obtain objective data, and to evaluate these cues under well-controlled experimental conditions.

  9. Au38Cu1(2-PET)24 nanocluster: synthesis, enantioseparation and luminescence.

    PubMed

    Kazan, Rania; Zhang, Bei; Bürgi, Thomas

    2017-06-20

    A CuAu 38 bimetallic nanocluster was synthesized by adding a single copper atom to the Au 38 (2-PET) 24 nanocluster. The absence of Cu x Au 38-x (2-PET) 24 doped species was demonstrated by MALDI-TOF mass spectrometry. A separation of bimetallic clusters was attained for the first time where isomers of the E2 enantiomer of the Au 38 Cu 1 (2-PET) 24 adduct were successfully isolated from their parent cluster using chiral HPLC. The CD of the isolated isomers revealed a change in their electronic structure upon copper addition. The luminescence of the Au 38 Cu 1 adduct is significantly enhanced in comparison with the parent Au 38 nanocluster. The stability of the newly formed adduct is strongly dependent on the coexistence of the Au 38 nanoclusters.

  10. Plasmon enhanced water splitting mediated by hybrid bimetallic Au-Ag core-shell nanostructures.

    PubMed

    Erwin, William R; Coppola, Andrew; Zarick, Holly F; Arora, Poorva; Miller, Kevin J; Bardhan, Rizia

    2014-11-07

    In this work, we employed wet chemically synthesized bimetallic Au-Ag core-shell nanostructures (Au-AgNSs) to enhance the photocurrent density of mesoporous TiO2 for water splitting and we compared the results with monometallic Au nanoparticles (AuNPs). While Au-AgNSs incorporated photoanodes give rise to 14× enhancement in incident photon to charge carrier efficiency, AuNPs embedded photoanodes result in 6× enhancement. By varying nanoparticle concentration in the photoanodes, we observed ∼245× less Au-AgNSs are required relative to AuNPs to generate similar photocurrent enhancement for solar fuel conversion. Power-dependent measurements of Au-AgNSs and AuNPs showed a first order dependence to incident light intensity, relative to half-order dependence for TiO2 only photoanodes. This indicated that plasmonic nanostructures enhance charge carriers formed on the surface of the TiO2 which effectively participate in photochemical reactions. Our experiments and simulations suggest the enhanced near-field, far-field, and multipolar resonances of Au-AgNSs facilitating broadband absorption of solar radiation collectively gives rise to their superior performance in water splitting.

  11. Synergistic effect in an Au-Ag alloy nanocatalyst: CO oxidation.

    PubMed

    Liu, Jun-Hong; Wang, Ai-Qin; Chi, Yu-Shan; Lin, Hong-Ping; Mou, Chung-Yuan

    2005-01-13

    Au-Ag alloy nanoparticles supported on mesoporous aluminosilicate have been prepared by one-pot synthesis using hexadecyltrimethylammonium bromide (CTAB) both as a stabilizing agent for nanoparticles and as a template for the formation of mesoporous structure. The formation of Au-Ag alloy nanoparticles was confirmed by X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectroscopy, and transmission electron microscopy (TEM). Although the Au-Ag alloy nanoparticles have a larger particle size than the monometallic gold particles, they exhibited exceptionally high activity in catalysis for low-temperature CO oxidation. Even at a low temperature of 250 K, the reaction rate can reach 8.7 x 10(-6) mol.g(cat.)(-1).s(-1) at an Au/Ag molar ratio of 3/1. While neither monometallic Au@MCM-41 nor Ag@MCM-41 shows activity at this temperature, the Au-Ag alloy system shows a strongly synergistic effect in high catalytic activity. In this alloy system, the size effect is no longer a critical factor, whereas Ag is believed to play a key role in the activation of oxygen.

  12. Nanoporous Au-based chronocoulometric aptasensor for amplified detection of Pb(2+) using DNAzyme modified with Au nanoparticles.

    PubMed

    Zhang, Chen; Lai, Cui; Zeng, Guangming; Huang, Danlian; Tang, Lin; Yang, Chunping; Zhou, Yaoyu; Qin, Lei; Cheng, Min

    2016-07-15

    The authors herein described an amplified detection strategy employing nanoporous Au (NPG) and gold nanoparticles (AuNPs) to detect Pb(2+) ions in aqueous solution. The thiol modified Pb(2+)-specific DNAzyme was self-assembled onto the surface of the NPG modified electrode for hybridizing with the AuNPs labeled oligonucleotide and for forming the DNA double helix structure. Electrochemical signal, redox charge of hexaammineruthenium(III) chloride (RuHex), was measured by chronocoulometry. Taking advantage of amplification effects of the NPG electrode for increasing the reaction sites of capture probe and DNA-AuNPs complexes for bringing about the adsorption of large numbers of RuHex molecules, this electrochemical sensor could detect Pb(2+) quantitatively, in the range of 0.05-100nM, with a limit of detection as low as 0.012nM. Selectivity measurements revealed that the sensor was specific for Pb(2+) even with interference by high concentrations of other metal ions. This sensor was also used to detect Pb(2+) ions from samples of tap water, river water, and landfill leachate samples spiked with Pb(2+) ions, and the results showed good agreement with the found values determined by an atomic fluorescence spectrometer. This simple aptasensor represented a promising potential for on-site detecting Pb(2+) in drinking water. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Theoretical prediction of a new stable structure of Au28(SR)20 cluster

    NASA Astrophysics Data System (ADS)

    Sun, Xiangxiang; Wang, Pu; Xiong, Lin; Pei, Yong

    2018-07-01

    A new stable structure of Au28(SR)20 cluster is predicted, which has the same gold core as two known structures but different Au-S framework. The new Au28(SR)20 cluster is proposed to be a key link in the evolution of Au22(SR)18, Au34(SR)22 and Au40(SR)24 clusters. The four clusters belong to a homogenous Au16+6N(SR)16+2N series (N = 1-4). The relative stabilities of the new Au28 isomer structure were confirmed by density functional theory calculations including dispersion corrections (DFT-D). It is found that upon protection of certain SR ligands, the new isomer structure has lower or comparable energies to two known cluster structures.

  14. Mammalian sensitivity to elemental gold (Au?)

    USGS Publications Warehouse

    Eisler, R.

    2004-01-01

    There is increasing documentation of allergic contact dermatitis and other effects from gold jewelry, gold dental restorations, and gold implants. These effects were especially pronounced among females wearing body-piercing gold objects. One estimate of the prevalence of gold allergy worldwide is 13%, as judged by patch tests with monovalent organogold salts. Eczema of the head and neck was the most common response of individuals hypersensitive to gold, and sensitivity can last for at least several years. Ingestion of beverages containing flake gold can result in allergic-type reactions similar to those seen in gold-allergic individuals exposed to gold through dermal contact and other routes. Studies with small laboratory mammals and injected doses of colloidal gold showed increased body temperatures, accumulations in reticular cells, and dose enhancement in tumor therapy; gold implants were associated with tissue injuries. It is proposed that Au? toxicity to mammals is associated, in part, with formation of the more reactive Au+ and Au3+ species.

  15. Durable electrocatalytic-activity of Pt-Au/C cathode in PEMFCs.

    PubMed

    Selvaganesh, S Vinod; Selvarani, G; Sridhar, P; Pitchumani, S; Shukla, A K

    2011-07-21

    Longevity remains as one of the central issues in the successful commercialization of polymer electrolyte membrane fuel cells (PEMFCs) and primarily hinges on the durability of the cathode. Incorporation of gold (Au) to platinum (Pt) is known to ameliorate both the electrocatalytic activity and stability of cathode in relation to pristine Pt-cathodes that are currently being used in PEMFCs. In this study, an accelerated stress test (AST) is conducted to simulate prolonged fuel-cell operating conditions by potential cycling the carbon-supported Pt-Au (Pt-Au/C) cathode. The loss in performance of PEMFC with Pt-Au/C cathode is found to be ∼10% after 7000 accelerated potential-cycles as against ∼60% for Pt/C cathode under similar conditions. These data are in conformity with the electrochemical surface-area values. PEMFC with Pt-Au/C cathode can withstand >10,000 potential cycles with very little effect on its performance. X-ray diffraction and transmission electron microscopy studies on the catalyst before and after AST suggest that incorporating Au with Pt helps mitigate aggregation of Pt particles during prolonged fuel-cell operations while X-ray photoelectron spectroscopy reflects that the metallic nature of Pt is retained in the Pt-Au catalyst during AST in comparison to Pt/C that shows a major portion of Pt to be present as oxidic platinum. Field-emission scanning electron microscopy conducted on the membrane electrode assembly before and after AST suggests that incorporating Au with Pt helps mitigating deformations in the catalyst layer. This journal is © the Owner Societies 2011

  16. Au doping effects on electrical and optical properties of vanadium dioxides

    NASA Astrophysics Data System (ADS)

    Zhu, YaBin; He, Fan; Na, Jie

    2012-03-01

    Vanadium dioxides were fabricated on normal glass substrates using reactive radio frequency (RF) magnetron sputtering. The oxygen flow volume and annealed temperatures as growth parameters are systematically investigated. The electrical and optical properties of VO2 and Au:VO2 thin films with different growth conditions are discussed. The semiconductor-metal phase transition temperature decreased by ˜10°C for the sample with Au doping compared to the sample without Au doping. However, the optical transmittance of Au:VO2 thin films is much lower than that of bare VO2. These results show that Au doping has a marked effect on the electrical and optical properties.

  17. On-Chip Supercapacitor Electrode Based On Polypyrrole Deposited Into Nanoporous Au Scaffold

    NASA Astrophysics Data System (ADS)

    Lu, P.; Ohlckers, P.; Chen, X. Y.

    2016-11-01

    On-chip supercapacitors hold the potential promise for serving as the energy storage units in integrated circuit system, due to their much higher energy density in comparison with conventional dielectric capacitors, high power density and long-term cycling stability. In this study, nanoporous Au (NP-Au) film on-chip was employed as the electrode scaffold to help increase the electrolyte-accessible area for active material. Pseudo-capacitive polypyrrole (PPY) with high theoretical capacitance was deposited into the NP-Au scaffold, to construct the tailored NP-Au/PPY hybrid on-chip electrode with improved areal capacitance. Half cell test in three- electrode system revealed the improved capacitor performance of nanoporous Au supported PPY electrode, compared to the densely packed PPY nanowire film electrode on planer Au substrate (Au/PPY). The areal capacitance of 37 mF/cm2∼10 mV/s, 32 mF/cm2∼50 mV/s, 28 mF/cm2∼100 mV/s, 16 mF/cm2∼500 mV/s, were offered by NP-Au/PPY. Also, the cycling performance was enhanced via using NP-Au scaffold. The developed NP-Au/PPY on-chip electrode demonstrated herein paves a feasible pathway to employ dealloying derived porous metal as the scaffold for improving both the energy density and cycling performance for supercapacitor electrodes.

  18. Atomic and electronic structures of Si(1 1 1)-\\left(\\sqrt{\\mathbf{3}}\\times\\sqrt{\\mathbf{3}}\\right)\\text{R}\\mathbf{3}{{\\mathbf{0}}^{\\circ}} -Au and (6 × 6)-Au surfaces

    NASA Astrophysics Data System (ADS)

    Patterson, C. H.

    2015-12-01

    Si(1 1 1)-Au surfaces with around one monolayer of Au exhibit many ordered structures and structures containing disordered domain walls. Hybrid density functional theory (DFT) calculations presented here reveal the origin of these complex structures and tendency to form domain walls. The conjugate honeycomb chain trimer (CHCT) structure of the \\sqrt{3} -Au phase contains Si atoms with non-bonding surface states which can bind Au atoms in pairs in interstices of the CHCT structure and make this surface metallic. Si adatoms adsorbed on the \\sqrt{3} -Au surface induce a gapped surface through interaction with the non-bonding states. Adsorption of extra Au atoms in interstitial sites of the \\sqrt{3} -Au surface is stabilized by interaction with the non-bonding orbitals and leads to higher coverage ordered structures including the ≤ft(6× 6\\right) -Au phase. Extra Au atoms bound in interstitial sites of the \\sqrt{3} -Au surface result in top layer Si atoms with an SiAu4 butterfly wing configuration. The structure of a ≤ft(6× 6\\right) -Au phase, whose in-plane top atomic layer positions were previously determined by an electron holography technique (Grozea et al 1998 Surf. Sci. 418 32), is calculated using total energy minimization. The Patterson function for this structure is calculated and is in good agreement with data from an in-plane x-ray diffraction study (Dornisch et al 1991 Phys. Rev. B 44 11221). Filled and empty state scanning tunneling microscopy (STM) images are calculated for domain walls and the ≤ft(6× 6\\right) -Au structure. The ≤ft(6× 6\\right) -Au phase is 2D chiral and this is evident in computed and actual STM images. ≤ft(6× 6\\right) -Au and domain wall structures contain the SiAu4 motif with a butterfly wing shape. Chemical bonding within the Si-Au top layers of the \\sqrt{3} -Au and ≤ft(6× 6\\right) -Au surfaces is analyzed and an explanation for the SiAu4 motif structure is given.

  19. Centrality Evolution of pt and yt Spectra from Au-Au Collisions at √ {sNN} = 200 GeV

    NASA Astrophysics Data System (ADS)

    Trainor, Thomas A.

    A two-component analysis of spectra to pt = 12 GeV/c for identified pions and protons from 200 GeV Au-Au collisions is presented. The method is similar to an analysis of the nch dependence of pt spectra from p-p collisions at 200 GeV, but applied to Au-Au centrality dependence. The soft-component reference is a Lévy distribution on transverse mass mt. The hard-component reference is a Gaussian on transverse rapidity yt with exponential (pt power-law) tail. Deviations of data from the reference are described by hard-component ratio rAA, which generalizes nuclear modification factor RAA. The analysis suggests that centrality evolution of pion and proton spectra is dominated by changes in parton fragmentation. The structure of rAA suggests that parton energy loss produces a negative boost Δyt of a large fraction (but not all) of the minimum-bias fragment distribution, and that lower-energy partons suffer relatively less energy loss, possibly due to color screening. The analysis also suggests that the anomalous p/π ratio may be due to differences in the parton energy-loss process experienced by the two hadron species. This analysis provides no evidence for radial flow.

  20. A novel thermal face recognition approach using face pattern words

    NASA Astrophysics Data System (ADS)

    Zheng, Yufeng

    2010-04-01

    A reliable thermal face recognition system can enhance the national security applications such as prevention against terrorism, surveillance, monitoring and tracking, especially at nighttime. The system can be applied at airports, customs or high-alert facilities (e.g., nuclear power plant) for 24 hours a day. In this paper, we propose a novel face recognition approach utilizing thermal (long wave infrared) face images that can automatically identify a subject at both daytime and nighttime. With a properly acquired thermal image (as a query image) in monitoring zone, the following processes will be employed: normalization and denoising, face detection, face alignment, face masking, Gabor wavelet transform, face pattern words (FPWs) creation, face identification by similarity measure (Hamming distance). If eyeglasses are present on a subject's face, an eyeglasses mask will be automatically extracted from the querying face image, and then masked with all comparing FPWs (no more transforms). A high identification rate (97.44% with Top-1 match) has been achieved upon our preliminary face dataset (of 39 subjects) from the proposed approach regardless operating time and glasses-wearing condition.e

  1. Interaction of Au with thin ZrO2 films: influence of ZrO2 morphology on the adsorption and thermal stability of Au nanoparticles.

    PubMed

    Pan, Yonghe; Gao, Yan; Kong, Dandan; Wang, Guodong; Hou, Jianbo; Hu, Shanwei; Pan, Haibin; Zhu, Junfa

    2012-04-10

    The model catalysts of ZrO(2)-supported Au nanoparticles have been prepared by deposition of Au atoms onto the surfaces of thin ZrO(2) films with different morphologies. The adsorption and thermal stability of Au nanoparticles on thin ZrO(2) films have been investigated using synchrotron radiation photoemission spectroscopy (SRPES) and X-ray photoelectron spectroscopy (XPS). The thin ZrO(2) films were prepared by two different methods, giving rise to different morphologies. The first method utilized wet chemical impregnation to synthesize the thin ZrO(2) film through the procedure of first spin-coating a zirconium ethoxide (Zr(OC(2)H(5))(4)) precursor onto a SiO(2)/Si(100) substrate at room temperature followed by calcination at 773 K for 12 h. Scanning electron microscopy (SEM) investigations indicate that highly porous "sponge-like nanostructures" were obtained in this case. The second method was epitaxial growth of a ZrO(2)(111) film through vacuum evaporation of Zr metal onto Pt(111) in 1 × 10(-6) Torr of oxygen at 550 K followed by annealing at 1000 K. The structural analysis with low energy electron diffraction (LEED) of this film exhibits good long-range ordering. It has been found that Au forms smaller particles on the porous ZrO(2) film as compared to those on the ordered ZrO(2)(111) film at a given coverage. Thermal annealing experiments demonstrate that Au particles are more thermally stable on the porous ZrO(2) surface than on the ZrO(2)(111) surface, although on both surfaces, Au particles experience significant sintering at elevated temperatures. In addition, by annealing the surfaces to 1100 K, Au particles desorb completely from ZrO(2)(111) but not from porous ZrO(2). The enhanced thermal stability for Au on porous ZrO(2) can be attributed to the stronger interaction of the adsorbed Au with the defects and the hindered migration or coalescence resulting from the porous structures. © 2012 American Chemical Society

  2. (Tl, Au)/Si(1 1 1){\\sqrt7 \\times \\sqrt7} 2D compound: an ordered array of identical Au clusters embedded in Tl matrix

    NASA Astrophysics Data System (ADS)

    Mihalyuk, A. N.; Hsing, C. R.; Wei, C. M.; Eremeev, S. V.; Bondarenko, L. V.; Tupchaya, A. Y.; Gruznev, D. V.; Zotov, A. V.; Saranin, A. A.

    2018-01-01

    Formation of the highly-ordered \\sqrt7 × \\sqrt7 -periodicity 2D compound has been detected in the (Tl, Au)/Si(1 1 1) system as a result of Au deposition onto the Tl/Si(1 1 1) surface, its composition, structure and electronic properties have been characterized using scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and density-functional-theory calculations. On the basis of these data, the structural model of the Tl-Au compound has been proposed, which adopts 12 Tl atoms and 10 Au atoms (in total, 22 atoms) per \\sqrt7 × \\sqrt7 unit cell, i.e.  ˜1.71 ML of Tl and  ˜1.43 ML of Au (in total, ˜3.14 ML). Qualitatively, the model can be visualized as consisting of truncated-pyramid-like Au clusters with a Tl atom on top, while the other Tl atoms form a double layer around the Au clusters. The (Tl, Au)/Si(1 1 1)\\sqrt7 × \\sqrt7 compound has been found to exhibit pronounced metallic properties at least down to temperatures as low as  ˜25 K, which makes it a promising object for studying electrical transport phenomena in the 2D metallic systems.

  3. Face time: educating face transplant candidates.

    PubMed

    Lamparello, Brooke M; Bueno, Ericka M; Diaz-Siso, Jesus Rodrigo; Sisk, Geoffroy C; Pomahac, Bohdan

    2013-01-01

    Face transplantation is the innovative application of microsurgery and immunology to restore appearance and function to those with severe facial disfigurements. Our group aims to establish a multidisciplinary education program that can facilitate informed consent and build a strong knowledge base in patients to enhance adherence to medication regimes, recovery, and quality of life. We analyzed handbooks from our institution's solid organ transplant programs to identify topics applicable to face transplant patients. The team identified unique features of face transplantation that warrant comprehensive patient education. We created a 181-page handbook to provide subjects interested in pursuing transplantation with a written source of information on the process and team members and to address concerns they may have. While the handbook covers a wide range of topics, it is easy to understand and visually appealing. Face transplantation has many unique aspects that must be relayed to the patients pursuing this novel therapy. Since candidates lack third-party support groups and programs, the transplant team must provide an extensive educational component to enhance this complex process. As face transplantation continues to develop, programs must create sound education programs that address patients' needs and concerns to facilitate optimal care.

  4. Au nanorods-incorporated plasmonic-enhanced inverted organic solar cells

    NASA Astrophysics Data System (ADS)

    Peng, Ling; Mei, Yang; Chen, Shu-Fen; Zhang, Yu-Pei; Hao, Jing-Yu; Deng, Ling-Ling; Huang, Wei

    2015-11-01

    The effect of Au nanorods (NRs) on optical-to-electric conversion efficiency is investigated in inverted polymer solar cells, in which Au NRs are sandwiched between two layers of ZnO. Accompanied by the optimization of thickness of ZnO covered on Au NRs, a high-power conversion efficiency of 3.60% and an enhanced short-circuit current density (JSC) of 10.87 mA/cm2 are achieved in the poly(3-hexylthiophene): [6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC60BM)-based inverted cell and the power conversion efficiency (PCE) is enhanced by 19.6% compared with the control device. The detailed analyses of the light absorption characteristics, the simulated scattering induced by Au NRs, and the electromagnetic field around Au NRs show that the absorption improvement in the photoactive layer due to the light scattering from the longitudinal axis and the near-field increase around Au NRs induced by localized surface plasmon resonance plays a key role in enhancing the performances. Project supported by the Ministry of Science and Technology, China (Grant No. 2012CB933301), the National Natural Science Foundation of China (Grant Nos. 61274065, 51173081, 61136003, BZ2010043, 51372119, and 51172110), and the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions and Synergetic Innovation Center for Organic Electronics and Information Displays, China.

  5. Systematic study of azimuthal anisotropy in Cu + Cu and Au + Au collisions at √{sNN}=62.4 and 200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Al-Jamel, A.; Alexander, J.; Aoki, K.; Aphecetche, L.; Armendariz, R.; Aronson, S. H.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Baksay, G.; Baksay, L.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Bazilevsky, A.; Belikov, S.; Bennett, R.; Berdnikov, Y.; Bickley, A. A.; Bjorndal, M. T.; Boissevain, J. G.; Borel, H.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Campbell, S.; Chai, J.-S.; Chang, B. S.; Charvet, J.-L.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Chujo, T.; Chung, P.; Churyn, A.; Cianciolo, V.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Das, K.; David, G.; Deaton, M. B.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Dubey, A. K.; Durum, A.; Dzhordzhadze, V.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Enokizono, A.; En'yo, H.; Espagnon, B.; Esumi, S.; Eyser, K. O.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fung, S.-Y.; Fusayasu, T.; Gadrat, S.; Garishvili, I.; Gastineau, F.; Germain, M.; Glenn, A.; Gong, H.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hagiwara, M. N.; Hamagaki, H.; Han, R.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Haslum, E.; Hasuko, K.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Heuser, J. M.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Hur, M. G.; Ichihara, T.; Iinuma, H.; Imai, K.; Inaba, M.; Inoue, Y.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Jacak, B. V.; Jia, J.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kaneta, M.; Kang, J. H.; Kanou, H.; Kawagishi, T.; Kawall, D.; Kazantsev, A. V.; Kelly, S.; Khanzadeev, A.; Kikuchi, J.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, Y.-S.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klay, J.; Klein-Boesing, C.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kroon, P. J.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Le Bornec, Y.; Leckey, S.; Lee, D. M.; Lee, M. K.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Lenzi, B.; Li, X.; Li, X. H.; Lim, H.; Liška, T.; Litvinenko, A.; Liu, M. X.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCain, M. C.; McCumber, M.; McGaughey, P. L.; Miake, Y.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, G. C.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Morreale, A.; Morrison, D. P.; Moss, J. M.; Moukhanova, T. V.; Mukhopadhyay, D.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Norman, B. E.; Nouicer, R.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Oka, M.; Okada, K.; Omiwade, O. O.; Oskarsson, A.; Otterlund, I.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, J.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Pisani, R. P.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Rykov, V. L.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakata, H.; Samsonov, V.; Sato, H. D.; Sato, S.; Sawada, S.; Seele, J.; Seidl, R.; Semenov, V.; Seto, R.; Sharma, D.; Shea, T. K.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunečka, M.; Smith, W. C.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sullivan, J. P.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanaka, K. H.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Taranenko, A.; Tarján, P.; Thomas, T. L.; Todoroki, T.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; Vale, C.; Valle, H.; van Hecke, H. W.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, Y.; Wessels, J.; White, S. N.; Willis, N.; Winter, D.; Woody, C. L.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.; Phenix Collaboration

    2015-09-01

    We have studied the dependence of azimuthal anisotropy v2 for inclusive and identified charged hadrons in Au +Au and Cu +Cu collisions on collision energy, species, and centrality. The values of v2 as a function of transverse momentum pT and centrality in Au +Au collisions at √{s NN}=200 and 62.4 GeV are the same within uncertainties. However, in Cu +Cu collisions we observe a decrease in v2 values as the collision energy is reduced from 200 to 62.4 GeV. The decrease is larger in the more peripheral collisions. By examining both Au +Au and Cu +Cu collisions we find that v2 depends both on eccentricity and the number of participants, Npart. We observe that v2 divided by eccentricity (ɛ ) monotonically increases with Npart and scales as Npart1 /3. The Cu +Cu data at 62.4 GeV falls below the other scaled v2 data. For identified hadrons, v2 divided by the number of constituent quarks nq is independent of hadron species as a function of transverse kinetic energy K ET=mT-m between 0.1

  6. Detection of CEA in human serum using surface-enhanced Raman spectroscopy coupled with antibody-modified Au and γ-Fe₂O₃@Au nanoparticles.

    PubMed

    Lin, Yan; Xu, Guanhong; Wei, Fangdi; Zhang, Aixia; Yang, Jing; Hu, Qin

    2016-03-20

    In this present work, a rapid and simple method to detect carcinoembryonic antigen (CEA) was developed by using surface-enhanced Raman spectroscopy (SERS) coupled with antibody-modified Au and γ-Fe2O3@Au nanoparticles. First, Au@Raman reporter and γ-Fe2O3@Au were prepared, and then modified with CEA antibody. When CEA was present, the immuno-Au@Raman reporter and immuno-γ-Fe2O3@Au formed a complex through antibody-antigen-antibody interaction. The selective and sensitive detection of CEA could be achieved by SERS after magnetic separation. Under the optimal conditions, a linear relationship was observed between the Raman peak intensity and the concentration of CEA in the range of 1-50 ng mL(-1) with an excellent correlation coefficient of 0.9942. The limit of detection based on two times ratio of signal to noise was 0.1 ng/mL. The recoveries of CEA standard solution spiked with human serum samples were in the range of 88.5-105.9% with the relative standard deviations less than 17.4%. The method built was applied to the detection of CEA in human serum, and the relative deviations of the analysis results between the present method and electrochemiluminescence immunoassay were all less than 16.6%. The proposed method is practical and has a potential for clinic test of CEA. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. The AU Mic debris ring: density profile and dynamics of the dust

    NASA Astrophysics Data System (ADS)

    Augereau, Jean-Charles; Beust, Herve

    2005-10-01

    AU Mic is an M-type star surrounded by a debris disk that is viewed almost perfectly edge-on. This disk shares many common observational properties with the well-known disk orbiting Beta Pictoris but the properties of the AU Mic disk as well as the dynamics of the dust grains have not been studied in detail yet. Using a standard deprojection technique, we derive the surface density profile of the AU Mic disk from near-IR scattered light observations. We show that irrespective of the asymmetry parameter of the phase function, most of the dust emission arises from a ring-like region that extends from 30 to 45 AU. We estimate that the mean collision time-scale at these distances is of the order of a few 10000 years. Therefore, collisional evolution can happen. A striking common feature between AU Mic and Beta Pic is the surface brightness profile. In both cases, the surface brightness falls off as r^{-5} further away than 120 AU in the case of Beta Pic and 35 AU in the case of AU Mic. In the case of Beta Pic, this profile is well explained by the combined effect of collisions and radiation pressure on the smallest dust particules (e.g. Augereau et al. 2001). But this model does not apply to AU Mic because of its low luminosity (thus generating a too low radiation pressure). Conversely, we show that a standard, solar-like stellar wind generates a drag force onto dust particles that behaves much like a radiation pressure. This wind pressure appears stronger than the radiation pressure itself and this effect is considerably enhanced by the recurrent stellar flares of AU Mic. This greatly contributes to populating the extended debris disk of AU Mic and explains the similarity between the Beta Pic and AU Mic brightness profiles.

  8. Evaluation of antibiotic self-medication among outpatients of the state university hospital of Port-Au-Prince, Haiti: a cross-sectional study.

    PubMed

    Moise, Kenny; Bernard, Joseph Junior; Henrys, Jean Hugues

    2017-01-01

    In Haiti, where all drugs are available over the counter, self-medication with antibiotics appears as a common practice. Inappropriate use of beta-lactams and macrolides is likely to contribute to the development of antimicrobial resistance. This study aimed to (i) assess the extent of self-medication with antibiotics, (ii) explore the contributing factors (age, gender and educational background) and (iii) identify specific antibiotic drug classes used among patients attending the outpatient clinic of the State University Hospital of Port-au-Prince. A cross-sectional survey among 200 outpatients of the State University Hospital of Port-au-Prince was conducted in December 2014. Face-to-face interviews were conducted using a standardized questionnaire. Parents of pediatric patients were allowed to answer to questions on their behalf. Among the study sample, 45.5% practiced self-medication with antibiotics. It was less prevalent among patients with the highest education level (23.1%; OR: 0.89 (0.5-1.75), p = 0.001). Mild symptoms (28.6%) and vaginal itching (44.4%) were the main reasons for self-medication with antibiotics. Self-medication using amoxicillin was reported by 67.0%. Self-medication with antibiotics is a common practice among Haitian patients and is more common among the less educated. Amoxicillin for urinary tract infections is the most commonly used medication. It is crucial to raise awareness on the dangers of the practice in the population and inforce the current law regarding the use of over the counter antibiotics.

  9. From face processing to face recognition: Comparing three different processing levels.

    PubMed

    Besson, G; Barragan-Jason, G; Thorpe, S J; Fabre-Thorpe, M; Puma, S; Ceccaldi, M; Barbeau, E J

    2017-01-01

    Verifying that a face is from a target person (e.g. finding someone in the crowd) is a critical ability of the human face processing system. Yet how fast this can be performed is unknown. The 'entry-level shift due to expertise' hypothesis suggests that - since humans are face experts - processing faces should be as fast - or even faster - at the individual than at superordinate levels. In contrast, the 'superordinate advantage' hypothesis suggests that faces are processed from coarse to fine, so that the opposite pattern should be observed. To clarify this debate, three different face processing levels were compared: (1) a superordinate face categorization level (i.e. detecting human faces among animal faces), (2) a face familiarity level (i.e. recognizing famous faces among unfamiliar ones) and (3) verifying that a face is from a target person, our condition of interest. The minimal speed at which faces can be categorized (∼260ms) or recognized as familiar (∼360ms) has largely been documented in previous studies, and thus provides boundaries to compare our condition of interest to. Twenty-seven participants were included. The recent Speed and Accuracy Boosting procedure paradigm (SAB) was used since it constrains participants to use their fastest strategy. Stimuli were presented either upright or inverted. Results revealed that verifying that a face is from a target person (minimal RT at ∼260ms) was remarkably fast but longer than the face categorization level (∼240ms) and was more sensitive to face inversion. In contrast, it was much faster than recognizing a face as familiar (∼380ms), a level severely affected by face inversion. Face recognition corresponding to finding a specific person in a crowd thus appears achievable in only a quarter of a second. In favor of the 'superordinate advantage' hypothesis or coarse-to-fine account of the face visual hierarchy, these results suggest a graded engagement of the face processing system across processing

  10. The effect of metal surface passivation on the Au-InP interaction

    NASA Technical Reports Server (NTRS)

    Fatemi, Navid S.; Weizer, Victor G.

    1989-01-01

    The effect of SiO2 encapsulation on reaction rates in the Au-InP system was studied. Scanning electron microscopy and x-ray photoelectron spectroscopy were used to investigate surface and/or interface morphologies and in-depth compositional profiles. It was found that the rate of dissolution of InP into Au and subsequent phase transformations are largely dependent on the condition of the free surface of the metalization. SiO2 capping of Au is reported for the first time to suppress the Au-InP reaction rate. The Au-InP interaction is shown to be quite similar to the Au-GaAs interaction despite differences in behavior of the group-V elements.

  11. Spectroscopically forbidden infra-red emission in Au-vertical graphene hybrid nanostructures

    NASA Astrophysics Data System (ADS)

    Sivadasan, A. K.; Parida, Santanu; Ghosh, Subrata; Pandian, Ramanathaswamy; Dhara, Sandip

    2017-11-01

    Implementation of Au nanoparticles (NPs) is a subject for frontier plasmonic research due to its fascinating optical properties. Herein, the present study deals with plasmonic assisted emission properties of Au NPs-vertical graphene (VG) hybrid nanostructures. The influence of effective polarizability of Au NPs on the surface enhanced Raman scattering and luminescence properties is investigated. In addition, a remarkable infra-red emission in the hybrid nanostructures is observed and interpreted on the basis of intra-band transitions in Au NPs. The flake-like nanoporous VG structure is invoked for the generation of additional confined photons to impart additional momentum and a gradient of confined excitation energy towards initiating the intra-band transitions of Au NPs. Integrating Au plasmonic materials in three-dimensional VG nanostructures enhances the light-matter interactions. The present study provides a new adaptable plasmonic assisted pathway for optoelectronic and sensing applications.

  12. Medical Requirements During a Natural Disaster: A Case Study on WhatsApp Chats Among Medical Personnel During the 2015 Nepal Earthquake.

    PubMed

    Basu, Moumita; Ghosh, Saptarshi; Jana, Arnab; Bandyopadhyay, Somprakash; Singh, Ravikant

    2017-12-01

    The objective of this study was to explore a log of WhatsApp messages exchanged among members of the health care group Doctors For You (DFY) while they were providing medical relief in the aftermath of the Nepal earthquake in April 2015. Our motivation was to identify medical resource requirements during a disaster in order to help government agencies and other responding organizations to be better prepared in any upcoming disaster. A large set of WhatsApp (WhatsApp Inc, Mountain View, CA) messages exchanged among DFY members during the Nepal earthquake was collected and analyzed to identify the medical resource requirements during different phases of relief operations. The study revealed detailed phase-wise requirements for various types of medical resources, including medicines, medical equipment, and medical personnel. The data also reflected some of the problems faced by the medical relief workers in the earthquake-affected region. The insights from this study may help not only the Nepalese government, but also authorities in other earthquake-prone regions of the world to better prepare for similar disasters in the future. Moreover, real-time analysis of such online data during a disaster would aid decision-makers in dynamically formulating resource-mapping strategies. (Disaster Med Public Health Preparedness. 2017;11:652-655).

  13. The rational design of a Au(I) precursor for focused electron beam induced deposition

    PubMed Central

    Marashdeh, Ali; Tiesma, Thiadrik; van Velzen, Niels J C; Harder, Sjoerd; Havenith, Remco W A; De Hosson, Jeff T M

    2017-01-01

    Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition. Aurophilic interactions are found to play a key role. The short lifetime of ClAuCO in vacuum is explained by strong, destabilizing Au–Au interactions in the solid phase. While aurophilic interactions do not affect the stability of ClAuPMe3, they leave the complex non-volatile. Comparison of crystal structures of ClAuPMe3 and MeAuPMe3 shows that Au–Au interactions are much weaker or partially even absent for the latter structure. This explains its high volatility. However, MeAuPMe3 dissociates unfavorably during FEBIP, making it an unsuitable precursor. The study shows that Me groups reduce aurophilic interactions, compared to Cl groups, which we attribute to electronic rather than steric effects. Therefore we propose MeAuCO as a potential FEBIP precursor. It is expected to have weak Au–Au interactions, making it volatile. It is stable enough to act as a volatile source for Au deposition, being stabilized by 6.5 kcal/mol. Finally, MeAuCO is likely to dissociate in a single step to pure Au. PMID:29354346

  14. Conjunction Faces Alter Confidence-Accuracy Relations for Old Faces

    ERIC Educational Resources Information Center

    Reinitz, Mark Tippens; Loftus, Geoffrey R.

    2017-01-01

    The authors used a state-trace methodology to investigate the informational dimensions used to recognize old and conjunction faces (made by combining parts of separately studied faces). Participants in 3 experiments saw faces presented for 1 s each. They then received a recognition test; faces were presented for varying brief durations and…

  15. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    ERIC Educational Resources Information Center

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants' face recognition abilities are subject to "perceptual narrowing", the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in…

  16. Au-Pt-Au nanoraspberry structures used for mercury ion detection

    NASA Astrophysics Data System (ADS)

    Huang, Jiang-Hao; Huang, Shuai; Wen, Xiaoyan; Li, Min; Lu, Haifei

    2017-12-01

    Detection of Hg2+ with high sensitivity is of great significance in the biochemical sensing field. Quantitative of Hg2+ was realized based on the influence of Hg2+ on the UV-vis absorption performance of Au-Pt-Au core-shell nanoraspberry (APA)-rhodamine-6G (R6G) structure. First, APA sol was added into R6G indicator solution and the UV-vis absorption signal intensity of R6G was evidently promoted. The signal intensity monotonously increased as more APA sol was added. However, when HgCl2 solution was introduced, the signal intensity declined. A linear relationship between Hg2+ concentration and signal intensity at 527 nm was revealed, based on which quantitative determination of Hg2+ could be realized. Hg2+ detection sensitivity was measured to be 0.031 a.u./M with a limit of detection of 10-7 M and the response time was 20 s. A high Hg2+ detection selectivity over Cu2+, Na+, Li+, and K+ was demonstrated. Due to its simplicity and high sensitivity, the proposed method could find an extensive application prospect in the Hg2+ detection field.

  17. Holistic face training enhances face processing in developmental prosopagnosia

    PubMed Central

    Cohan, Sarah; Nakayama, Ken

    2014-01-01

    Prosopagnosia has largely been regarded as an untreatable disorder. However, recent case studies using cognitive training have shown that it is possible to enhance face recognition abilities in individuals with developmental prosopagnosia. Our goal was to determine if this approach could be effective in a larger population of developmental prosopagnosics. We trained 24 developmental prosopagnosics using a 3-week online face-training program targeting holistic face processing. Twelve subjects with developmental prosopagnosia were assessed before and after training, and the other 12 were assessed before and after a waiting period, they then performed the training, and were then assessed again. The assessments included measures of front-view face discrimination, face discrimination with view-point changes, measures of holistic face processing, and a 5-day diary to quantify potential real-world improvements. Compared with the waiting period, developmental prosopagnosics showed moderate but significant overall training-related improvements on measures of front-view face discrimination. Those who reached the more difficult levels of training (‘better’ trainees) showed the strongest improvements in front-view face discrimination and showed significantly increased holistic face processing to the point of being similar to that of unimpaired control subjects. Despite challenges in characterizing developmental prosopagnosics’ everyday face recognition and potential biases in self-report, results also showed modest but consistent self-reported diary improvements. In summary, we demonstrate that by using cognitive training that targets holistic processing, it is possible to enhance face perception across a group of developmental prosopagnosics and further suggest that those who improved the most on the training task received the greatest benefits. PMID:24691394

  18. Study on plasmon absorption of hybrid Au-GO-GNP films for SPR sensing application

    NASA Astrophysics Data System (ADS)

    Mukhtar, Wan Maisarah; Ahmad, Farah Hayati; Samsuri, Nurul Diyanah; Murat, Noor Faezah

    2018-06-01

    This study proposed the development of hybrid Au-GO-GNP films for the enhancement of plasmon absorption in SPR sensing. Several thicknesses of Au at t=40nm, t=50nm and t=300nm were sputtered on the glass substrate. The hybridization of bilayer and trilayer films were formed by depositing GO-GNP layers and GNP-GO layers on top of various thicknesses of Au coated substrates. UV-Vis spectra analysis was conducted to characterize the plasmon absorption for each configuration. The plasmon absorption was successfully amplified by employing hybrid trilayer Au-GO-GNP with the thickness of Au film was fixed at t=50nm. It is noteworthy to highlight that the employment of bilayer and trilayer configurations are the key success to enhance the SPP excitation. Au-GNP and Au-GNP-GO results no significant outcome in comparison with Au-GO and Au-GO-GNP. A redshift of the absorbance wavelength evinces the presence of GO on Au-GO sample and GNP on Au-GO-GNP sample due to the surface reconstruction. It is important to emphasize that not all bilayer and trilayer configurations able to enhance the plasmon absorption where no significant output was obtained with the hybridization order of Au-GNP and Au-GNP-GO.

  19. Crystal structure and electronic properties of a thiolate-protected Au24 nanocluster

    NASA Astrophysics Data System (ADS)

    Das, Anindita; Li, Tao; Li, Gao; Nobusada, Katsuyuki; Zeng, Chenjie; Rosi, Nathaniel L.; Jin, Rongchao

    2014-05-01

    Solving the total structures of gold nanoclusters is of critical importance for understanding their electronic, optical and catalytic properties. Herein, we report the X-ray structure of a charge-neutral Au24(SCH2Ph-tBu)20 nanocluster. This structure features a bi-tetrahedral Au8 kernel protected by four tetrameric staple-like motifs. Electronic structure analysis is further carried out and the optical absorption spectrum is interpreted. The Au24(SCH2Ph-tBu)20, Au23(S-c-C6H11)16 and Au25(SCH2CH2Ph)18 nanoclusters constitute the first crystallographically characterized ``trio''.Solving the total structures of gold nanoclusters is of critical importance for understanding their electronic, optical and catalytic properties. Herein, we report the X-ray structure of a charge-neutral Au24(SCH2Ph-tBu)20 nanocluster. This structure features a bi-tetrahedral Au8 kernel protected by four tetrameric staple-like motifs. Electronic structure analysis is further carried out and the optical absorption spectrum is interpreted. The Au24(SCH2Ph-tBu)20, Au23(S-c-C6H11)16 and Au25(SCH2CH2Ph)18 nanoclusters constitute the first crystallographically characterized ``trio''. Electronic supplementary information (ESI) available: Experimental and supporting Fig. S1-S3. CCDC NUMBER(1000102). For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4nr01350f

  20. Kinetically controlled synthesis of Au102(SPh)44 nanoclusters and catalytic application

    NASA Astrophysics Data System (ADS)

    Chen, Yongdong; Wang, Jin; Liu, Chao; Li, Zhimin; Li, Gao

    2016-05-01

    We here explore a kinetically controlled synthetic protocol for preparing solvent-solvable Au102(SPh)44 nanoclusters which are isolated from polydispersed gold nanoclusters by solvent extraction and size exclusion chromatography (SEC). The as-obtained Au102(SPh)44 nanoclusters are determined by matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometry, in conjunction with UV-vis spectroscopy and thermogravimetric analysis (TGA). However, Au99(SPh)42, instead of Au102(SPh)44, is yielded when the polydispersed gold nanoclusters are etched in the presence of excess thiophenol under thermal conditions (e.g., 80 °C). Interestingly, the Au102(SPh)44 nanoclusters also can convert to Au99(SPh)42 with equivalent thiophenol ligands, evidenced by the analyses of UV-vis and MALDI mass spectrometry. Finally, the TiO2-supported Au102(SPh)44 nanocluster catalyst is investigated in the selective oxidation of sulfides into sulfoxides by the PhIO oxidant and gives rise to high catalytic activity (e.g., 80-99% conversion of R-S-R' sulfides with 96-99% selectivity for R-S(&z.dbd;O)-R' sulfoxides). The Au102(SPh)44/TiO2 catalyst also shows excellent recyclability in the sulfoxidation process.We here explore a kinetically controlled synthetic protocol for preparing solvent-solvable Au102(SPh)44 nanoclusters which are isolated from polydispersed gold nanoclusters by solvent extraction and size exclusion chromatography (SEC). The as-obtained Au102(SPh)44 nanoclusters are determined by matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometry, in conjunction with UV-vis spectroscopy and thermogravimetric analysis (TGA). However, Au99(SPh)42, instead of Au102(SPh)44, is yielded when the polydispersed gold nanoclusters are etched in the presence of excess thiophenol under thermal conditions (e.g., 80 °C). Interestingly, the Au102(SPh)44 nanoclusters also can convert to Au99(SPh)42 with equivalent

  1. Suppression pattern of neutral pions at high transverse momentum in Au + Au collisions at sqrt[sNN]=200 GeV and constraints on medium transport coefficients.

    PubMed

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Al-Jamel, A; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bauer, F; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bickley, A A; Bjorndal, M T; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Brown, D S; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Campbell, S; Chai, J-S; Chang, B S; Charvet, J-L; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Das, K; David, G; Deaton, M B; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Enokizono, A; En'yo, H; Espagnon, B; Esumi, S; Eyser, K O; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Forestier, B; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fung, S-Y; Fusayasu, T; Gadrat, S; Garishvili, I; Gastineau, F; Germain, M; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H-A; Hachiya, T; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hagiwara, M N; Hamagaki, H; Han, R; Harada, H; Hartouni, E P; Haruna, K; Harvey, M; Haslum, E; Hasuko, K; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; Heuser, J M; He, X; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holmes, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Hur, M G; Ichihara, T; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kanou, H; Kawagishi, T; Kawall, D; Kazantsev, A V; Kelly, S; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, E; Kim, Y-S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klay, J; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kroon, P J; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y-S; Lajoie, J G; Lebedev, A; Le Bornec, Y; Leckey, S; Lee, D M; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Lim, H; Liska, T; Litvinenko, A; Liu, M X; Li, X; Li, X H; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mao, Y; Masek, L; Masui, H; Matathias, F; McCain, M C; McCumber, M; McGaughey, P L; Miake, Y; Mikes, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, G C; Mishra, M; Mitchell, J T; Mitrovski, M; Morreale, A; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Norman, B E; Nyanin, A S; Nystrand, J; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, H; Okada, K; Oka, M; Omiwade, O O; Oskarsson, A; Otterlund, I; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Ryu, S S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakata, H; Samsonov, V; Sato, H D; Sato, S; Sawada, S; Seele, J; Seidl, R; Semenov, V; Seto, R; Sharma, D; Shea, T K; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shimomura, M; Shohjoh, T; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Slunecka, M; Smith, W C; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sullivan, J P; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Thomas, T L; Togawa, M; Toia, A; Tojo, J; Tomásek, L; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Tuli, S K; Tydesjö, H; Tyurin, N; Vale, C; Valle, H; van Hecke, H W; Velkovska, J; Vertesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zimányi, J; Zolin, L

    2008-12-05

    For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < pT < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e.g., q in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.

  2. Au nanorice assemble electrolytically into mesostars.

    PubMed

    Bardhan, Rizia; Neumann, Oara; Mirin, Nikolay; Wang, Hui; Halas, Naomi J

    2009-02-24

    Star-shaped mesotructures are formed when an aqueous suspension of Au nanorice particles, which consist of prolate hematite cores and a thin Au shell, is subjected to an electric current. The nanorice particles assemble to form hyperbranched micrometer-scale mesostars. To our knowledge, this is the first reported observation of nanoparticle assembly into larger ordered structures under the influence of an electrochemical process (H(2)O electrolysis). The assembly is accompanied by significant modifications in the morphology, dimensions, chemical composition, crystallographic structure, and optical properties of the constituent nanoparticles.

  3. The complex duration perception of emotional faces: effects of face direction.

    PubMed

    Kliegl, Katrin M; Limbrecht-Ecklundt, Kerstin; Dürr, Lea; Traue, Harald C; Huckauf, Anke

    2015-01-01

    The perceived duration of emotional face stimuli strongly depends on the expressed emotion. But, emotional faces also differ regarding a number of other features like gaze, face direction, or sex. Usually, these features have been controlled by only using pictures of female models with straight gaze and face direction. Doi and Shinohara (2009) reported that an overestimation of angry faces could only be found when the model's gaze was oriented toward the observer. We aimed at replicating this effect for face direction. Moreover, we explored the effect of face direction on the duration perception sad faces. Controlling for the sex of the face model and the participant, female and male participants rated the duration of neutral, angry, and sad face stimuli of both sexes photographed from different perspectives in a bisection task. In line with current findings, we report a significant overestimation of angry compared to neutral face stimuli that was modulated by face direction. Moreover, the perceived duration of sad face stimuli did not differ from that of neutral faces and was not influenced by face direction. Furthermore, we found that faces of the opposite sex appeared to last longer than those of the same sex. This outcome is discussed with regards to stimulus parameters like the induced arousal, social relevance, and an evolutionary context.

  4. Core–Shell Au@Metal-Oxide Nanoparticle Electrocatalysts for Enhanced Oxygen Evolution

    DOE PAGES

    Strickler, Alaina L.; Escudero-Escribano, Marı́a; Jaramillo, Thomas F.

    2017-09-25

    Enhanced catalysis for electrochemical oxygen evolution is essential for the efficacy of many renewable energy technologies, including water electrolyzers and metal–air batteries. Recently, Au supports have been shown to enhance the activity of many 3d transition metal-oxide thin films for the oxygen evolution reaction (OER) in alkaline media. In this paper, we translate the beneficial impact of Au supports to high surface area, device-ready core–shell nanoparticles consisting of a Au-core and a metal-oxide shell (Au@M xO y where M = Ni, Co, Fe, and CoFe). Through a systematic evaluation, we establish trends in performance and illustrate the universal activity enhancementmore » when employing the Au-core in the 3d transition metal-oxide nanoparticles. Finally, the highest activity particles, Au@CoFeO x, demonstrate an overpotential of 328 ± 3 mV over a 2 h stability test at 10 mA cm –2, illustrating that strategically coupling Au support and mixed metal-oxide effects in a core–shell nanoparticle morphology is a promising avenue to achieve device-ready, high-performance OER catalysts.« less

  5. Core–Shell Au@Metal-Oxide Nanoparticle Electrocatalysts for Enhanced Oxygen Evolution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strickler, Alaina L.; Escudero-Escribano, Marı́a; Jaramillo, Thomas F.

    Enhanced catalysis for electrochemical oxygen evolution is essential for the efficacy of many renewable energy technologies, including water electrolyzers and metal–air batteries. Recently, Au supports have been shown to enhance the activity of many 3d transition metal-oxide thin films for the oxygen evolution reaction (OER) in alkaline media. In this paper, we translate the beneficial impact of Au supports to high surface area, device-ready core–shell nanoparticles consisting of a Au-core and a metal-oxide shell (Au@M xO y where M = Ni, Co, Fe, and CoFe). Through a systematic evaluation, we establish trends in performance and illustrate the universal activity enhancementmore » when employing the Au-core in the 3d transition metal-oxide nanoparticles. Finally, the highest activity particles, Au@CoFeO x, demonstrate an overpotential of 328 ± 3 mV over a 2 h stability test at 10 mA cm –2, illustrating that strategically coupling Au support and mixed metal-oxide effects in a core–shell nanoparticle morphology is a promising avenue to achieve device-ready, high-performance OER catalysts.« less

  6. Structure and optical properties of silica-supported Ag-Au nanoparticles.

    PubMed

    Barreca, Davide; Gasparotto, Alberto; Maragno, Cinzia; Tondello, Eugenio; Gialanella, Stefano

    2007-07-01

    Bimetallic Ag-Au nanoparticles are synthesized by sequential deposition of Au and Ag on amorphous silica by Radio Frequency (RF)-sputtering under mild conditions. Specimens are thoroughly characterized by a multi-technique approach, aimed at investigating the system properties as a function of the Ag/Au content, as well as the evolution induced by ex-situ annealing under inert (N2) or reducing (4% H2/N2) atmospheres. The obtained results demonstrate the possibility to obtain Ag-Au alloyed nanoparticles with controllable size, shape, structure, and dispersion under mild conditions, so that the optical properties can be finely tuned as a function of the synthesis and thermal treatment conditions.

  7. Energy dependence of J/ψ production in Au + Au collisions at s N N = 39 , 62.4  and  200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.

    The inclusive J/ψ transverse momentum spectra and nuclear modification factors are reported at mid-rapidity (|y|<1.0) in Au + Au collisions at √sNN = 39, 62.4 and 200 GeV taken by the STAR experiment. A suppression of J/ψ production, with respect to the production in p+p scaled by the number of binary nucleon–nucleon collisions, is observed in central Au + Au collisions at these three energies. No significant energy dependence of nuclear modification factors is found within uncertainties. The measured nuclear modification factors can be described by model calculations that take into account both suppression of direct J/ψ production due tomore » the color screening effect and J/ψ regeneration from recombination of uncorrelated charm–anticharm quark pairs.« less

  8. Dependence of Morphology of SiOx Nanowires on the Supersaturation of Au-Si Alloy Liquid Droplets Formed on the Au-Coated Si Substrate

    NASA Astrophysics Data System (ADS)

    Zhang, Han; Li, Ji-Xue; Jin, Ai-Zi; Zhang, Ze

    2001-11-01

    A thermodynamic theory about the dependence of morphology of SiOx nanowires on the super-saturation of alloy liquid droplets has been proposed on the basis of the vapour-liquid-solid growth mechanism and has been supported experimentally. By changing the Si concentration in the Au-Si liquid droplets formed on the Au-coated Si substrate, firework-, tulip- and bud-shaped SiOx nanowires were synthesized by a thermal evaporation method and distributed concentrically around some void defects in the Si substrate. Voids were formed underneath the surface of the Si substrate during the thermal evaporation at 850°C and resulted in the Si-concentration deficient thus different saturation of Au-Si droplets. Electron microscopy analysis showed that the nanowires had an amorphous structure and were terminated by Au-Si particles.

  9. Energy dependence of J/ψ production in Au + Au collisions at s N N = 39 , 62.4  and  200 GeV

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2017-05-10

    The inclusive J/ψ transverse momentum spectra and nuclear modification factors are reported at mid-rapidity (|y|<1.0) in Au + Au collisions at √sNN = 39, 62.4 and 200 GeV taken by the STAR experiment. A suppression of J/ψ production, with respect to the production in p+p scaled by the number of binary nucleon–nucleon collisions, is observed in central Au + Au collisions at these three energies. No significant energy dependence of nuclear modification factors is found within uncertainties. The measured nuclear modification factors can be described by model calculations that take into account both suppression of direct J/ψ production due tomore » the color screening effect and J/ψ regeneration from recombination of uncorrelated charm–anticharm quark pairs.« less

  10. Face detection and eyeglasses detection for thermal face recognition

    NASA Astrophysics Data System (ADS)

    Zheng, Yufeng

    2012-01-01

    Thermal face recognition becomes an active research direction in human identification because it does not rely on illumination condition. Face detection and eyeglasses detection are necessary steps prior to face recognition using thermal images. Infrared light cannot go through glasses and thus glasses will appear as dark areas in a thermal image. One possible solution is to detect eyeglasses and to exclude the eyeglasses areas before face matching. In thermal face detection, a projection profile analysis algorithm is proposed, where region growing and morphology operations are used to segment the body of a subject; then the derivatives of two projections (horizontal and vertical) are calculated and analyzed to locate a minimal rectangle of containing the face area. Of course, the searching region of a pair of eyeglasses is within the detected face area. The eyeglasses detection algorithm should produce either a binary mask if eyeglasses present, or an empty set if no eyeglasses at all. In the proposed eyeglasses detection algorithm, block processing, region growing, and priori knowledge (i.e., low mean and variance within glasses areas, the shapes and locations of eyeglasses) are employed. The results of face detection and eyeglasses detection are quantitatively measured and analyzed using the manually defined ground truths (for both face and eyeglasses). Our experimental results shown that the proposed face detection and eyeglasses detection algorithms performed very well in contrast with the predefined ground truths.

  11. Epitaxial CdSe-Au nanocrystal heterostructures by thermal annealing.

    PubMed

    Figuerola, Albert; van Huis, Marijn; Zanella, Marco; Genovese, Alessandro; Marras, Sergio; Falqui, Andrea; Zandbergen, Henny W; Cingolani, Roberto; Manna, Liberato

    2010-08-11

    The thermal evolution of a collection of heterogeneous CdSe-Au nanosystems (Au-decorated CdSe nanorods, networks, vertical assemblies) prepared by wet-chemical approaches was monitored in situ in the transmission electron microscope. In contrast to interfaces that are formed during kinetically controlled wet chemical synthesis, heating under vacuum conditions results in distinct and well-defined CdSe/Au interfaces, located at the CdSe polar surfaces. The high quality of these interfaces should make the heterostructures more suitable for use in nanoscale electronic devices.

  12. A causal relationship between face-patch activity and face-detection behavior.

    PubMed

    Sadagopan, Srivatsun; Zarco, Wilbert; Freiwald, Winrich A

    2017-04-04

    The primate brain contains distinct areas densely populated by face-selective neurons. One of these, face-patch ML, contains neurons selective for contrast relationships between face parts. Such contrast-relationships can serve as powerful heuristics for face detection. However, it is unknown whether neurons with such selectivity actually support face-detection behavior. Here, we devised a naturalistic face-detection task and combined it with fMRI-guided pharmacological inactivation of ML to test whether ML is of critical importance for real-world face detection. We found that inactivation of ML impairs face detection. The effect was anatomically specific, as inactivation of areas outside ML did not affect face detection, and it was categorically specific, as inactivation of ML impaired face detection while sparing body and object detection. These results establish that ML function is crucial for detection of faces in natural scenes, performing a critical first step on which other face processing operations can build.

  13. Low-symmetry structures of Au32Z (Z = +1, 0, -1) clusters.

    PubMed

    Jalbout, Abraham F; Contreras-Torres, Flavio F; Pérez, Luis A; Garzón, Ignacio L

    2008-01-24

    In this work, we have explored new stable structures of the Au32Z (Z = +1, 0, -1) clusters. Theoretical calculations using density functional theory within the generalized-gradient approximation were performed. Our results show that, in the anion state (Au32-), low-symmetry (disordered) structures are preferred over the caged fullerene-like isomer. In addition, the cationic cluster (Au32+) also exhibits a disordered low-symmetry structure as its lowest energy configuration, but it is much closer in energy to the fullerene-like isomer. These results, obtained at T = 0 K, indicate that disordered structures for the Au32- and Au32+ clusters may be detected not only at room temperature, as was experimentally verified for the Au32- one, but also at much lower temperatures.

  14. Annealing temperature effect on self-assembled Au droplets on Si (111).

    PubMed

    Sui, Mao; Li, Ming-Yu; Kim, Eun-Soo; Lee, Jihoon

    2013-12-13

    We investigate the effect of annealing temperature on self-assembled Au droplets on Si (111). The annealing temperature is systematically varied while fixing other growth parameters such as deposition amount and annealing duration clearly to observe the annealing temperature effect. Self-assembled Au droplets are fabricated by annealing from 50°C to 850°C with 2-nm Au deposition for 30 s. With increased annealing temperatures, Au droplets show gradually increased height and diameter while the density of droplets progressively decreases. Self-assembled Au droplets with fine uniformity can be fabricated between 550°C and 800°C. While Au droplets become much larger with increased deposition amount, the extended annealing duration only mildly affects droplet size and density. The results are systematically analyzed with cross-sectional line profiles, Fourier filter transform power spectra, height histogram, surface area ratio, and size and density plots. This study can provide an aid point for the fabrication of nanowires on Si (111).

  15. A superconducting battery material: Lithium gold boride (LiAu3B)

    NASA Astrophysics Data System (ADS)

    Aydin, Sezgin; Şimşek, Mehmet

    2018-04-01

    The superconducting and potential cathode material properties of ternary boride of LiAu3B have been investigated by density functional first principles. The Li-concentration effects on the actual electronic and structural properties, namely the properties of LixAu9B3 (x = 0, 1, 2) sub-systems are studied. It is remarkably shown that the existence of Li-atoms has no considerable effect on the structural properties of Au-B skeleton in LiAu3B. Then, it can be offered as a potential cathode material for Li-ion batteries with the very small volume deviation of 0.42%, and the suitable average open circuit voltage of ∼1.30 V. Furthermore, the vibrational and superconducting properties such as electron-phonon coupling constant (λ) and critical temperature (Tc) of LiAu3B are studied. The calculated results suggest that LiAu3B should be a superconductor with Tc ∼5.8 K, also.

  16. Face Time: Educating Face Transplant Candidates

    PubMed Central

    Lamparello, Brooke M.; Bueno, Ericka M.; Diaz-Siso, Jesus Rodrigo; Sisk, Geoffroy C.; Pomahac, Bohdan

    2013-01-01

    Objective: Face transplantation is the innovative application of microsurgery and immunology to restore appearance and function to those with severe facial disfigurements. Our group aims to establish a multidisciplinary education program that can facilitate informed consent and build a strong knowledge base in patients to enhance adherence to medication regimes, recovery, and quality of life. Methods: We analyzed handbooks from our institution's solid organ transplant programs to identify topics applicable to face transplant patients. The team identified unique features of face transplantation that warrant comprehensive patient education. Results: We created a 181-page handbook to provide subjects interested in pursuing transplantation with a written source of information on the process and team members and to address concerns they may have. While the handbook covers a wide range of topics, it is easy to understand and visually appealing. Conclusions: Face transplantation has many unique aspects that must be relayed to the patients pursuing this novel therapy. Since candidates lack third-party support groups and programs, the transplant team must provide an extensive educational component to enhance this complex process. Practice Implications: As face transplantation continues to develop, programs must create sound education programs that address patients’ needs and concerns to facilitate optimal care. PMID:23861990

  17. Alternative face models for 3D face registration

    NASA Astrophysics Data System (ADS)

    Salah, Albert Ali; Alyüz, Neşe; Akarun, Lale

    2007-01-01

    3D has become an important modality for face biometrics. The accuracy of a 3D face recognition system depends on a correct registration that aligns the facial surfaces and makes a comparison possible. The best results obtained so far use a one-to-all registration approach, which means each new facial surface is registered to all faces in the gallery, at a great computational cost. We explore the approach of registering the new facial surface to an average face model (AFM), which automatically establishes correspondence to the pre-registered gallery faces. Going one step further, we propose that using a couple of well-selected AFMs can trade-off computation time with accuracy. Drawing on cognitive justifications, we propose to employ category-specific alternative average face models for registration, which is shown to increase the accuracy of the subsequent recognition. We inspect thin-plate spline (TPS) and iterative closest point (ICP) based registration schemes under realistic assumptions on manual or automatic landmark detection prior to registration. We evaluate several approaches for the coarse initialization of ICP. We propose a new algorithm for constructing an AFM, and show that it works better than a recent approach. Finally, we perform simulations with multiple AFMs that correspond to different clusters in the face shape space and compare these with gender and morphology based groupings. We report our results on the FRGC 3D face database.

  18. Direct observation of interfacial Au atoms on TiO₂ in three dimensions.

    PubMed

    Gao, Wenpei; Sivaramakrishnan, Shankar; Wen, Jianguo; Zuo, Jian-Min

    2015-04-08

    Interfacial atoms, which result from interactions between the metal nanoparticles and support, have a large impact on the physical and chemical properties of nanoparticles. However, they are difficult to observe; the lack of knowledge has been a major obstacle toward unraveling their role in chemical transformations. Here we report conclusive evidence of interfacial Au atoms formed on the rutile (TiO2) (110) surfaces by activation using high-temperature (∼500 °C) annealing in air. Three-dimensional imaging was performed using depth-sectioning enabled by aberration-corrected scanning transmission electron microscopy. Results show that the interface between Au nanocrystals and TiO2 (110) surfaces consists of a single atomic layer with Au atoms embedded inside Ti-O. The number of interfacial Au atoms is estimated from ∼1-8 in an interfacial atomic column. Direct impact of interfacial Au atoms is observed on an enhanced Au-TiO2 interaction and the reduction of surface TiO2; both are critical to Au catalysis.

  19. Surface-enhanced Raman spectroscopy with Au-nanoparticle substrate fabricated by using femtosecond pulse.

    PubMed

    Zhang, Wending; Li, Cheng; Gao, Kun; Lu, Fanfan; Liu, Min; Li, Xin; Zhang, Lu; Mao, Dong; Gao, Feng; Huang, Ligang; Mei, Ting; Zhao, Jianlin

    2018-05-18

    Au-nanoparticle (Au-NP) substrates for surface-enhanced Raman spectroscopy (SERS) were fabricated by grid-like scanning a Au-film using a femtosecond pulse. The Au-NPs were directly deposited on the Au-film surface due to the scanning process. The experimentally obtained Au-NPs presented local surface plasmon resonance effect in the visible spectral range, as verified by finite difference time domain simulations and measured reflection spectrum. The SERS experiment using the Au-NP substrates exhibited high activity and excellent substrate reproducibility and stability, and a clearly present Raman spectra of target analytes, e.g. Rhodamine-6G, Rhodamine-B and Malachite green, with concentrations down to 10 -9 M. This work presents an effective approach to producing Au-NP SERS substrates with advantages in activity, reproducibility and stability, which could be used in a wide variety of practical applications for trace amount detection.

  20. Surface-enhanced Raman spectroscopy with Au-nanoparticle substrate fabricated by using femtosecond pulse

    NASA Astrophysics Data System (ADS)

    Zhang, Wending; Li, Cheng; Gao, Kun; Lu, Fanfan; Liu, Min; Li, Xin; Zhang, Lu; Mao, Dong; Gao, Feng; Huang, Ligang; Mei, Ting; Zhao, Jianlin

    2018-05-01

    Au-nanoparticle (Au-NP) substrates for surface-enhanced Raman spectroscopy (SERS) were fabricated by grid-like scanning a Au-film using a femtosecond pulse. The Au-NPs were directly deposited on the Au-film surface due to the scanning process. The experimentally obtained Au-NPs presented local surface plasmon resonance effect in the visible spectral range, as verified by finite difference time domain simulations and measured reflection spectrum. The SERS experiment using the Au-NP substrates exhibited high activity and excellent substrate reproducibility and stability, and a clearly present Raman spectra of target analytes, e.g. Rhodamine-6G, Rhodamine-B and Malachite green, with concentrations down to 10‑9 M. This work presents an effective approach to producing Au-NP SERS substrates with advantages in activity, reproducibility and stability, which could be used in a wide variety of practical applications for trace amount detection.

  1. Withholding response to self-face is faster than to other-face.

    PubMed

    Zhu, Min; Hu, Yinying; Tang, Xiaochen; Luo, Junlong; Gao, Xiangping

    2015-01-01

    Self-face advantage refers to adults' response to self-face is faster than that to other-face. A stop-signal task was used to explore how self-face advantage interacted with response inhibition. The results showed that reaction times of self-face were faster than that of other-face not in the go task but in the stop response trials. The novelty of the finding was that self-face has shorter stop-signal reaction time compared to other-face in the successful inhibition trials. These results indicated the processing mechanism of self-face may be characterized by a strong response tendency and a corresponding strong inhibition control.

  2. Serial block-face scanning electron microscopy applied to study the trafficking of 8D3-coated gold nanoparticles at the blood-brain barrier.

    PubMed

    Cabezón, Itsaso; Augé, Elisabet; Bosch, Manel; Beckett, Alison J; Prior, Ian A; Pelegrí, Carme; Vilaplana, Jordi

    2017-07-01

    Due to the physical and physiological properties of the blood-brain barrier (BBB), the transport of neurotherapeutics from blood to brain is still a pharmaceutical challenge. We previously conducted a series of experiments to explore the potential of the anti-transferrin receptor 8D3 monoclonal antibody (mAb) to transport neurotherapeutics across the BBB. In that study, gold nanoparticles (AuNPs) were coated with the 8D3 antibody and administered intravenously to mice. Transmission electron microscopy was used and a two-dimensional (2D) image analysis was performed to detect the AuNPs in the brain capillary endothelial cells (BCECs) and brain parenchyma. In the present work, we determined that serial block-face scanning electron microscopy (SBF-SEM) is a useful tool to study the transcytosis of these AuNPs across the BBB in three dimensions and we, therefore, applied it to gain more knowledge of their transcellular trafficking. The resulting 3D reconstructions provided additional information on the endocytic vesicles containing AuNPs and the endosomal processing that occurs inside BCECs. The passage from 2D to 3D analysis reinforced the trafficking model proposed in the 2D study, and revealed that the vesicles containing AuNPs are significantly larger and more complex than described in our 2D study. We also discuss tradeoffs of using this technique for our application, and conclude that together with other volume electron microscopy imaging techniques, SBF-SEM is a powerful approach that is worth of considering for studies of drug transport across the BBB.

  3. Antibacterial Au nanostructured surfaces

    NASA Astrophysics Data System (ADS)

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-01-01

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was <1% of that from flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It

  4. Energy levels, wavelengths, and transition rates of multipole transitions (E1, E2, M1, M2) in Au{sup 67+} and Au{sup 66+} ions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hamasha, Safeia, E-mail: safeia@hu.edu.jo

    2013-11-15

    The fully relativistic configuration interaction method of the FAC code is used to calculate atomic data for multipole transitions in Mg-like Au (Au{sup 67+}) and Al-like Au (Au{sup 66+}) ions. Generated atomic data are important in the modeling of M-shell spectra for heavy Au ions and Au plasma diagnostics. Energy levels, oscillator strengths and transition rates are calculated for electric-dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) for transitions between excited and ground states 3l−nl{sup ′}, such that n=4,5,6,7. The local central potential is derived using the Dirac–Fock–Slater method. Correlation effects to all orders are consideredmore » by the configuration interaction expansion. All relativistic effects are included in the calculations. Calculated energy levels are compared against published values that were calculated using the multi-reference many body perturbation theory, which includes higher order QED effects. Favorable agreement was observed, with less than 0.15% difference.« less

  5. Dielectron azimuthal anisotropy at mid-rapidity in Au + Au collisions at s N N = 200 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.

    We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e- pairs) at mid-rapidity from √sNN=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Mee<1.1 GeV/c2 the dielectron v2 measurements are found to be consistent with expectations from π0,η,ω, and Φ decay contributions. In the mass region 1.1

  6. Elliptic flow due to charged hadrons for Au+Au collisions at RHIC energy 62.4 GeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kumar, Somani Ajit, E-mail: ajit.somani@gmail.com; Sudhir, Bhardwaj; Ashish, Agnihotri

    Elliptic flow is an important observable in search of Quark Gluon Plasma. The elliptic flow parameter dependence on centrality due to charged hadrons were studied using events generated by event generator AMPT at center of mass energy of 62.4 GeV per nucleon pair for Au+Au collisions. This study performed for pseudorapidity range from −0.35 to 0.35 and transverse momentum bins p{sub t} = 0.2 to 1 GeV/c and 1 to 2 GeV/c. We compared the results obtained from simulated data and RHIC-PHENIX data.

  7. Systematic study of azimuthal anisotropy in Cu + Cu and Au + Au collisions at √s NN = 62.4 and 200 GeV

    DOE PAGES

    Adare, A.

    2015-09-23

    We have studied the dependence of azimuthal anisotropy v 2 for inclusive and identified charged hadrons in Au+Au and Cu+Cu collisions on collision energy, species, and centrality. The values of v 2 as a function of transverse momentum pT and centrality in Au+Au collisions at √s NN=200 and 62.4 GeV are the same within uncertainties. However, in Cu+Cu collisions we observe a decrease in v 2 values as the collision energy is reduced from 200 to 62.4 GeV. The decrease is larger in the more peripheral collisions. By examining both Au+Au and Cu+Cu collisions we find that v 2 dependsmore » both on eccentricity and the number of participants, N part. We observe that v 2 divided by eccentricity (ε) monotonically increases with N part and scales as N 1/3 part. Thus, the Cu+Cu data at 62.4 GeV falls below the other scaled v 2 data. For identified hadrons, v 2 divided by the number of constituent quarks nq is independent of hadron species as a function of transverse kinetic energy KE T=m T–m between 0.1T/n q<1 GeV. Combining all of the above scaling and normalizations, we observe a near-universal scaling, with the exception of the Cu+Cu data at 62.4 GeV, of v 2/(n q∙ε∙N 1/3 part) vs KE T/n q for all measured particles.« less

  8. Extraordinary epitaxial alignment of graphene islands on Au(111)

    NASA Astrophysics Data System (ADS)

    Wofford, Joseph M.; Starodub, Elena; Walter, Andrew L.; Nie, Shu; Bostwick, Aaron; Bartelt, Norman C.; Thürmer, Konrad; Rotenberg, Eli; McCarty, Kevin F.; Dubon, Oscar D.

    2012-05-01

    Pristine, single-crystalline graphene displays a unique collection of remarkable electronic properties that arise from its two-dimensional, honeycomb structure. Using in situ low-energy electron microscopy, we show that when deposited on the (111) surface of Au carbon forms such a structure. The resulting monolayer, epitaxial film is formed by the coalescence of dendritic graphene islands that nucleate at a high density. Over 95% of these islands can be identically aligned with respect to each other and to the Au substrate. Remarkably, the dominant island orientation is not the better lattice-matched 30° rotated orientation but instead one in which the graphene [01] and Au [011] in-plane directions are parallel. The epitaxial graphene film is only weakly coupled to the Au surface, which maintains its reconstruction under the slightly p-type doped graphene. The linear electronic dispersion characteristic of free-standing graphene is retained regardless of orientation. That a weakly interacting, non-lattice matched substrate is able to lock graphene into a particular orientation is surprising. This ability, however, makes Au(111) a promising substrate for the growth of single crystalline graphene films.

  9. Acetanilide mediated reversible assembly and disassembly of Au nanoparticles.

    PubMed

    Murugadoss, A; Kar, Manoranjan; Chattopadhyay, Arun

    2008-08-01

    Herein we report the generation of Au nanoparticles (NPs) by sparingly soluble acetanilide in water. We also report the formation of linear chain-like superstructures of self-assembled Au NPs, in the presence of excess acetanilide. This was achieved in two different ways. In the first method, acetanilide was added, with increasing concentration, into aqueous HAuCl(4) to produce Au NPs as well as for the formation of assembly, which varied according to the concentration of acetanilide. The other route involved formation of spherical Au NPs at the lowest concentration of acetanilide, which was followed by the formation of assembly of various lengths upon further addition of variable amount of acetanilide. The assemblies were stable in aqueous solution for days with characteristic UV-vis absorption spectra consisting of two peaks. While the wavelength of the first peak remained the same, the position of the second peak changed to longer wavelength with increasing acetanilide concentration. Interestingly, the linear chain-like arrays could be broken into individual particles by first dilution of the solution concentration followed by treatment with ultrasonic waves. The individual Au NPs again formed linear chain-like arrays upon addition of excess acetanilide.

  10. Development flight instrumentation for the redesigned solid rocket booster for the Space Shuttle program

    NASA Astrophysics Data System (ADS)

    Stevens, Walter H.

    This paper describes the upgraded development flight instrumentation (DFI) system for monitoring the performance of the redesigned solid rocket boosters. The DFI system, which was manufactured, qualification tested, and subsequently flown on STS-26 on September 29, 1988, consists of one main power distributor, two frequency division multiplexers, two wideband signal conditioners one PCM subsystem, one chamber pressure signal conditioner, one tape recorder, and one battery. The PCM subsystem, which was newly designed for this application, consists of one programmable master unit and three identical remote slave units. These units conditioned all of the information received from the sensors and multiplexed this data into one encoded PCM data stream and two independent FM composite outputs. Block diagrams of the DFI system and its subsystems are included.

  11. Fabrication of Pt/Au concentric spheres from triblock copolymer.

    PubMed

    Koh, Haeng-Deog; Park, Soojin; Russell, Thomas P

    2010-02-23

    Dispersion of an aqueous H(2)PtCl(6) solution into a trifluorotoluene (TFT) solution of a polystyrene-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) (PS-b-P2VP-b-PEO) triblock copolymer produced an emulsion-induced hollow micelle (EIHM), comprising a water nanodroplet stabilized by PEO, H(2)PtCl(6)/P2VP, and PS, sequentially. The following addition of an aqueous LiAuCl(4) solution into the dispersion led to a coordination of LiAuCl(4) and PEO. The resulting spherical EIHM structure was transformed to a hollow cylindrical micelle by the fusion of spherical EIHM with the addition of methanol. This structural transition was reversible by the alternative addition of methanol and TFT. Oxygen plasma was used to generate Pt/Au concentric spheres and hollow cylindrical Pt/Au nano-objects.

  12. About-face on face recognition ability and holistic processing.

    PubMed

    Richler, Jennifer J; Floyd, R Jackie; Gauthier, Isabel

    2015-01-01

    Previous work found a small but significant relationship between holistic processing measured with the composite task and face recognition ability measured by the Cambridge Face Memory Test (CFMT; Duchaine & Nakayama, 2006). Surprisingly, recent work using a different measure of holistic processing (Vanderbilt Holistic Face Processing Test [VHPT-F]; Richler, Floyd, & Gauthier, 2014) and a larger sample found no evidence for such a relationship. In Experiment 1 we replicate this unexpected result, finding no relationship between holistic processing (VHPT-F) and face recognition ability (CFMT). A key difference between the VHPT-F and other holistic processing measures is that unique face parts are used on each trial in the VHPT-F, unlike in other tasks where a small set of face parts repeat across the experiment. In Experiment 2, we test the hypothesis that correlations between the CFMT and holistic processing tasks are driven by stimulus repetition that allows for learning during the composite task. Consistent with our predictions, CFMT performance was correlated with holistic processing in the composite task when a small set of face parts repeated over trials, but not when face parts did not repeat. A meta-analysis confirms that relationships between the CFMT and holistic processing depend on stimulus repetition. These results raise important questions about what is being measured by the CFMT, and challenge current assumptions about why faces are processed holistically.

  13. About-face on face recognition ability and holistic processing

    PubMed Central

    Richler, Jennifer J.; Floyd, R. Jackie; Gauthier, Isabel

    2015-01-01

    Previous work found a small but significant relationship between holistic processing measured with the composite task and face recognition ability measured by the Cambridge Face Memory Test (CFMT; Duchaine & Nakayama, 2006). Surprisingly, recent work using a different measure of holistic processing (Vanderbilt Holistic Face Processing Test [VHPT-F]; Richler, Floyd, & Gauthier, 2014) and a larger sample found no evidence for such a relationship. In Experiment 1 we replicate this unexpected result, finding no relationship between holistic processing (VHPT-F) and face recognition ability (CFMT). A key difference between the VHPT-F and other holistic processing measures is that unique face parts are used on each trial in the VHPT-F, unlike in other tasks where a small set of face parts repeat across the experiment. In Experiment 2, we test the hypothesis that correlations between the CFMT and holistic processing tasks are driven by stimulus repetition that allows for learning during the composite task. Consistent with our predictions, CFMT performance was correlated with holistic processing in the composite task when a small set of face parts repeated over trials, but not when face parts did not repeat. A meta-analysis confirms that relationships between the CFMT and holistic processing depend on stimulus repetition. These results raise important questions about what is being measured by the CFMT, and challenge current assumptions about why faces are processed holistically. PMID:26223027

  14. First steps towards small arrays of Mo/Au microcalorimeters

    NASA Astrophysics Data System (ADS)

    Olsen, J.; Kirk, E. C.; Thomsen, K.; van den Brandt, B.; Lerch, Ph; Scandella, L.; Zehnder, A.; Mango, S.; Ott, H. R.; Huber, M.; Hilton, G. C.; Martinis, J. M.

    2000-04-01

    We are developing small arrays of microcalorimeters based on transition edge sensors made with Mo/Au bilayers deposited on silicon nitride membranes and Au absorbers. The superconducting transition of the bilayers is adjusted to be around 130 mK with a transition width better than a millikelvin by use of the proximity effect between the Au and Mo films. We built a dilution refrigerator and wired it for 2 channel operation in order to study thermal coupling issues between thermometers within the array. The device fabrication procedure as well as preliminary results are presented.

  15. A novel sandwich-type electrochemical aptasensor based on GR-3D Au and aptamer-AuNPs-HRP for sensitive detection of oxytetracycline.

    PubMed

    Liu, Su; Wang, Yu; Xu, Wei; Leng, Xueqi; Wang, Hongzhi; Guo, Yuna; Huang, Jiadong

    2017-02-15

    In this paper, a novel sandwich-type electrochemical aptasensor has been fabricated and applied for sensitive and selective detection of antibiotic oxytetracycline (OTC). This sensor was based on graphene-three dimensional nanostructure gold nanocomposite (GR-3D Au) and aptamer-AuNPs-horseradish peroxidase (aptamer-AuNPs-HRP) nanoprobes as signal amplification. Firstly, GR-3D Au film was modified on glassy carbon electrode only by one-step electrochemical coreduction with graphite oxide (GO) and HAuCl 4 at cathodic potentials, which enhanced the electron transfer and loading capacity of biomolecules. Then the aptamer and HRP modified Au nanoparticles provide high affinity and ultrasensitive electrochemical probe with excellent specificity for OTC. Under the optimized conditions, the peak current was linearly proportional to the concentration of OTC in the range of 5×10 -10 -2×10 -3 gL -1 , with a detection limit of 4.98×10 -10 gL -1 . Additionally, this aptasensor had the advantages in high sensitivity, superb specificity and showed good recovery in synthetic samples. Hence, the developed sandwich-type electrochemical aptasensor might provide a useful and practical tool for OTC determination and related food safety analysis and clinical diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Syn-deformational features of Carlin-type Au deposits

    USGS Publications Warehouse

    Peters, S.G.

    2004-01-01

    Syn-deformational ore deposition played an important role in some Carlin-type Au deposits according to field and laboratory evidence, which indicates that flow of Au-bearing fluids was synchronous with regional-scale deformation events. Gold-related deformation events linked to ore genesis were distinct from high-level, brittle deformation that is typical of many epithermal deposits. Carlin-type Au deposits, with brittle-ductile features, most likely formed during tectonic events that were accompanied by significant fluid flow. Interactive deformation-fluid processes involved brittle-ductile folding, faulting, shearing, and gouge development that were focused along illite-clay and dissolution zones caused by hydrothermal alteration. Alteration along these deformation zones resulted in increased porosity and enhancement of fluid flow, which resulted in decarbonated, significant dissolution, collapse, and volume and mass reduction. Carlin-type Au deposits commonly are hosted in Paleozoic and Mesozoic sedimentary rocks (limestone, siltstone, argillite, shale, and quartzite) on the margins of cratons. The sedimentary basins containing the host rocks underwent tectonic events that influenced the development of stratabound, structurally controlled orebodies. Published by Elsevier Ltd.

  17. Manipulation of Spin-Torque Generation Using Ultrathin Au

    NASA Astrophysics Data System (ADS)

    An, Hongyu; Haku, Satoshi; Kanno, Yusuke; Nakayama, Hiroyasu; Maki, Hideyuki; Shi, Ji; Ando, Kazuya

    2018-06-01

    The generation and the manipulation of current-induced spin-orbit torques are of essential interest in spintronics. However, in spite of the vital progress in spin orbitronics, electric control of the spin-torque generation still remains elusive and challenging. We report on electric control of the spin-torque generation using ionic-liquid gating of ultrathin Au. We show that by simply depositing a SiO2 capping layer on an ultrathin-Au /Ni81Fe19 bilayer, the spin-torque generation efficiency is drastically enhanced by a maximum of 7 times. This enhancement is verified to be originated from the rough ultrathin-Au /Ni81Fe19 interface induced by the SiO2 deposition, which results in the enhancement of the interface spin-orbit scattering. We further show that the spin-torque generation efficiency from the ultrathin Au film can be reversibly manipulated by a factor of 2 using the ionic gating with an external electric field within a small range of 1 V. These results pave a way towards the efficient control of the spin-torque generation in spintronic applications.

  18. Single cytidine units-templated syntheses of multi-colored water-soluble Au nanoclusters

    NASA Astrophysics Data System (ADS)

    Jiang, Hui; Zhang, Yuanyuan; Wang, Xuemei

    2014-08-01

    Ultra-small metallic nanoparticles, or so-called ``nanoclusters'' (NCs), have attracted considerable interest due to their unique optical properties that are different from both larger nanoparticles and single atoms. To prepare high-quality NCs, the stabilizing agent plays an essential role. In this work, we have revealed and validated that cytidine and its nucleotides (cytidine 5'-monophosphate or cytidine 5'-triphosphate) can act as efficient stabilizers for syntheses of multicolored Au NCs. Interestingly, Au NCs with blue, green and yellow fluorescence emissions are simultaneously obtained using various pH environments or reaction times. The transmission electron microscopy verifies that the size of Au NCs ranges from 1.5 to 3 nm. The X-ray photoelectron spectroscopy confirms that only Au (0) species are present in NCs. Generally, the facile preparation of multicolored Au NCs that are stabilized by cytidine units provides access to promising candidates for multiple biolabeling applications.Ultra-small metallic nanoparticles, or so-called ``nanoclusters'' (NCs), have attracted considerable interest due to their unique optical properties that are different from both larger nanoparticles and single atoms. To prepare high-quality NCs, the stabilizing agent plays an essential role. In this work, we have revealed and validated that cytidine and its nucleotides (cytidine 5'-monophosphate or cytidine 5'-triphosphate) can act as efficient stabilizers for syntheses of multicolored Au NCs. Interestingly, Au NCs with blue, green and yellow fluorescence emissions are simultaneously obtained using various pH environments or reaction times. The transmission electron microscopy verifies that the size of Au NCs ranges from 1.5 to 3 nm. The X-ray photoelectron spectroscopy confirms that only Au (0) species are present in NCs. Generally, the facile preparation of multicolored Au NCs that are stabilized by cytidine units provides access to promising candidates for multiple

  19. Porphyry Cu-Au and associated polymetallic Fe-Cu-Au deposits in the Beiya Area, western Yunnan Province, south China

    USGS Publications Warehouse

    Xu, X.-W.; Cai, X.-P.; Xiao, Q.-B.; Peters, S.G.

    2007-01-01

    The Alkaline porphyries in the Beiya area are located east of the Jinshajiang suture, as part of a Cenozoic alkali-rich porphyry belt in western Yunnan. The main rock types include quartz-albite porphyry, quartz-K-feldspar porphyry and biotite-K-feldspar porphyry. These porphyries are characterised by high alkalinity [(K2O + Na2O)% > 10%], high silica (SiO2% > 65%), high Sr (> 400??ppm) and 87Sr/86Sr (> 0.706)] ratio and were intruded at 65.5??Ma, between 25.5 to 32.5??Ma, and about 3.8??Ma, respectively. There are five main types of mineral deposits in the Beiya area: (1) porphyry Cu-Au deposits, (2) magmatic Fe-Au deposits, (3) sedimentary polymetallic deposits, (4) polymetallic skarn deposits, and (5) palaeoplacers associated with karsts. The porphyry Cu-Au and polymetallic skarn deposits are associated with quartz-albite porphyry bodies. The Fe-Au and polymetallic sedimentary deposits are part of an ore-forming system that produced considerable Au in the Beiya area, and are characterised by low concentrations of La, Ti, and Co, and high concentrations of Y, Yb, and Sc. The Cenozoic porphyries in western Yunnan display increased alkalinity away from the Triassic Jinshajiang suture. Distribution of both the porphyries and sedimentary deposits in the Beiya area are interpreted to be related to partial melting in a disjointed region between upper mantle lithosphere of the Yangtze Plate and Gondwana continent, and lie within a shear zone between buried Palaeo-Tethyan oceanic lithosphere and upper mantle lithosphere, caused by the subduction and collision of India and Asia. ?? 2006 Elsevier B.V. All rights reserved.

  20. Catalytic activity of nanostructured Au: Scale effects versus bimetallic/bifunctional effects in low-temperature CO oxidation on nanoporous Au

    PubMed Central

    Wang, Lu-Cun; Zhong, Yi; Jin, Haijun; Widmann, Daniel; Weissmüller, Jörg

    2013-01-01

    Summary The catalytic properties of nanostructured Au and their physical origin were investigated by using the low-temperature CO oxidation as a test reaction. In order to distinguish between structural effects (structure–activity correlations) and bimetallic/bifunctional effects, unsupported nanoporous gold (NPG) samples prepared from different Au alloys (AuAg, AuCu) by selective leaching of a less noble metal (Ag, Cu) were employed, whose structure (surface area, ligament size) as well as their residual amount of the second metal were systematically varied by applying different potentials for dealloying. The structural and chemical properties before and after 1000 min reaction were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The catalytic behavior was evaluated by kinetic measurements in a conventional microreactor and by dynamic measurements in a temporal analysis of products (TAP) reactor. The data reveal a clear influence of the surface contents of residual Ag and Cu species on both O2 activation and catalytic activity, while correlations between activity and structural parameters such as surface area or ligament/crystallite size are less evident. Consequences for the mechanistic understanding and the role of the nanostructure in these NPG catalysts are discussed. PMID:23503603

  1. Tuning the Kondo effect in thin Au films by depositing a thin layer of Au on molecular spin-dopants.

    PubMed

    Ataç, D; Gang, T; Yilmaz, M D; Bose, S K; Lenferink, A T M; Otto, C; de Jong, M P; Huskens, J; van der Wiel, W G

    2013-09-20

    We report on the tuning of the Kondo effect in thin Au films containing a monolayer of cobalt(II) terpyridine complexes by altering the ligand structure around the Co(2+) ions by depositing a thin Au capping layer on top of the monolayer on Au by magnetron sputtering (more energetic) and e-beam evaporation (softer). We show that the Kondo effect is slightly enhanced with respect to that of the uncapped film when the cap is deposited by evaporation, and significantly enhanced when magnetron sputtering is used. The Kondo temperature (TK) increases from 3 to 4.2/6.2 K for the evaporated/sputtered caps. X-ray absorption spectroscopy and surface-enhanced Raman spectroscopy investigation showed that the organic ligands remain intact upon Au e-beam evaporation; however, sputtering inflicts significant change in the Co(2+) electronic environment. The location of the monolayer-on the surface or embedded in the film-has a small effect. However, the damage of Co-N bonds induced by sputtering has a drastic effect on the increase of the impurity-electron interaction. This opens up the way for tuning of the magnetic impurity states, e.g. spin quantum number, binding energy with respect to the host Fermi energy, and overlap via the ligand structure around the ions.

  2. Dilepton Production in p+p, Au+Au collisions at √{sNN} = 200GeV and U+U collisions at √{sNN} = 193GeV

    NASA Astrophysics Data System (ADS)

    Brandenburg, James D.; STAR Collaboration

    2017-11-01

    In this contribution we report e+e1 spectra with various invariant mass and pT differentials in Au+Au collisions at √{sNN} = 200GeV and U+U collisions at √{sNN} = 193GeV. The structure of the t (- t ≈ pT2) distributions of these mass regions will be shown and compared with the same distributions in ultra-peripheral collisions. Additionally, this contribution discusses first measurements of μ+μ- invariant mass spectra from STAR's recently installed Muon Telescope Detector (MTD) in p+p and Au+Au collisions at √{sNN} = 200GeV.

  3. Au-Ge MEAM potential fitted to the binary phase diagram

    NASA Astrophysics Data System (ADS)

    Wang, Yanming; Santana, Adriano; Cai, Wei

    2017-02-01

    We have developed a modified embedded atom method potential for the gold-germanium (Au-Ge) binary system that is fitted to the experimental binary phase diagram. The phase diagram is obtained from the common tangent construction of the free energy curves calculated by the adiabatic switching method. While maintaining the accuracy of the melting points of pure Au and Ge, this potential reproduces the eutectic temperature, eutectic composition and the solubility of Ge in solid Au, all in good agreement with the experimental values. To demonstrate the self-consistency of the potential, we performed benchmark molecular dynamics simulations of Ge crystal growth and etching in contact with a Au-Ge liquid alloy.

  4. Platinum(iv) prodrug conjugated Pd@Au nanoplates for chemotherapy and photothermal therapy

    NASA Astrophysics Data System (ADS)

    Shi, Saige; Chen, Xiaolan; Wei, Jingping; Huang, Yizhuan; Weng, Jian; Zheng, Nanfeng

    2016-03-01

    Owing to the excellent near infrared (NIR) light absorption and efficient passive targeting toward tumor tissue, two-dimensional (2D) core-shell PEGylated Pd@Au nanoplates have great potential in both photothermal therapy and drug delivery systems. In this work, we successfully conjugate Pd@Au nanoplates with a platinum(iv) prodrug c,c,t-[Pt(NH3)2Cl2(O2CCH2CH2CO2H)2] to obtain a nanocomposite (Pd@Au-PEG-Pt) for combined photothermal-chemotherapy. The prepared Pd@Au-PEG-Pt nanocomposite showed excellent stability in physiological solutions and efficient Pt(iv) prodrug loading. Once injected into biological tissue, the Pt(iv) prodrug was easily reduced by physiological reductants (e.g. ascorbic acid or glutathione) into its cytotoxic and hydrophilic Pt(ii) form and released from the original nanocomposite, and the NIR laser irradiation could accelerate the release of Pt(ii) species. More importantly, Pd@Au-PEG-Pt has high tumor accumulation (29%ID per g), which makes excellent therapeutic efficiency at relatively low power density possible. The in vivo results suggested that, compared with single therapy the combined thermo-chemotherapy treatment with Pd@Au-PEG-Pt resulted in complete destruction of the tumor tissue without recurrence, while chemotherapy using Pd@Au-PEG-Pt without irradiation or photothermal treatment using Pd@Au-PEG alone did not. Our work highlights the prospects of a feasible drug delivery strategy of the Pt prodrug by using 2D Pd@Au nanoplates as drug delivery carriers for multimode cancer treatment.Owing to the excellent near infrared (NIR) light absorption and efficient passive targeting toward tumor tissue, two-dimensional (2D) core-shell PEGylated Pd@Au nanoplates have great potential in both photothermal therapy and drug delivery systems. In this work, we successfully conjugate Pd@Au nanoplates with a platinum(iv) prodrug c,c,t-[Pt(NH3)2Cl2(O2CCH2CH2CO2H)2] to obtain a nanocomposite (Pd@Au-PEG-Pt) for combined photothermal-chemotherapy. The

  5. Azimuthal anisotropy and correlations at large transverse momenta in p + p and Au + Au collisions at square root sNN=200 GeV.

    PubMed

    Adams, J; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhasin, A; Bhati, A K; Bhatia, V S; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopdhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; de Moura, M M; Derevschikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Foley, K J; Fomenko, K; Fu, J; Gagliardi, C A; Gans, J; Ganti, M S; Gaudichet, L; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grebenyuk, O; Grosnick, D; Guertin, S M; Guo, Y; Gupta, A; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Urkinbaev, A; Van Buren, G; van Leeuwen, M; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Vznuzdaev, M; Waggoner, W T; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Wells, R; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zanevsky, Y V; Zhang, H; Zhang, W M; Zhang, Z P; Zolnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

    2004-12-17

    Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au + Au collisions at square root s(NN)=200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au + Au collisions to those in p + p at the same energy. The elliptic anisotropy v(2) is found to reach its maximum at p(t) approximately 3 GeV/c, then decrease slowly and remain significant up to p(t) approximately 7-10 GeV/c. Stronger suppression is found in the back-to-back high-p(t) particle correlations for particles emitted out of plane compared to those emitted in plane. The centrality dependence of v(2) at intermediate p(t) is compared to simple models based on jet quenching.

  6. Kinetic Investigation of Homogeneous H(2)-D(2) Equilibration Catalyzed by Pt-Au Cluster Compounds. Characterization of the Cluster [(H)Pt(AuPPh(3))(9)](NO(3))(2).

    PubMed

    Rubinstein, Leon I.; Pignolet, Louis H.

    1996-11-06

    The new Pt-Au hydrido cluster compound [(H)Pt(AuPPh(3))(9)](NO(3))(2) (3) has been synthesized and characterized by NMR, FABMS, and single-crystal X-ray diffraction [triclinic, P&onemacr;, a = 17.0452(1) Å, b = 17.4045(2) Å, c = 55.2353(1) Å, alpha = 89.891(1) degrees, beta = 85.287(1) degrees, gamma = 75.173(1) degrees, V = 15784.0(2) Å(3), Z = 4 (two molecules in asymmetric unit), residual R = 0.089 for 45 929 observed reflections and 3367 variables, Mo Kalpha radiation]. The Pt(AuP)(9) core geometry is a distorted icosahedron with three vertices vacant. The Pt-Au, Au-Au, and Au-P distances are within the normal ranges observed in other Pt-Au clusters. This cluster is a catalyst for H(2)-D(2) equilibration in homogeneous solution phase and has been used in a general mechanistic study of this reaction catalyzed by Pt-Au clusters. We previously proposed that a key step in the mechanism for catalytic H(2)-D(2) equilibration is the dissociation of a PPh(3) ligand to give a cluster with an open Au site for bonding of H(2) or D(2). This was based on qualitative observations that PPh(3) inhibited the rate of HD production with [Pt(AuPPh(3))(8)](NO(3))(2) (1) as catalyst. In order to test this hypothesis, phosphine inhibition (on the rate of HD production) and phosphine ligand exchange kinetic experiments were carried out with [(H)(PPh(3))Pt(AuPPh(3))(7)](NO(3))(2) (2) and 3. In this paper we show that the rate constant for phosphine dissociation determined from the PPh(3) inhibition rate study of H(2)-D(2) equilibration with cluster 2 is nearly identical to the rate constant for dissociative phosphine ligand exchange. The slower rate for H(2)-D(2) equilibration observed with 3 compared with 2 (5.5 x 10(-3) vs 7.7 x 10(-2) turnover s(-1)) is explained by its smaller rate constant for phosphine dissociation (2.8 x 10(-5) vs 2.9 x 10(-4) s(-1)). The fact that clusters 2 and 3 show similar kinetic behaviors suggests that the PPh(3) dissociation step in the catalytic H(2

  7. Determination of Impact Parameters in Aligned Breakup of Projectile-like Fragments in $$^{197}$$Au + $$^{197}$$Au Collisions at 23$A$MeV

    DOE PAGES

    Cap, T.; Siwek-Wilczyńska, K.; Wilczynski, J.; ...

    2016-03-01

    Symmetric and asymmetric aligned breakup of projectile-like fragments inmore » $$^{197}$$Au + $$^{197}$$Au collisions at 23$A$,MeV was studied. Independently of the asymmetry, the reaction yields have been found peaked at a common, very narrow range of impact parameters.« less

  8. Biosupported Bimetallic Pd Au Nanocatalysts for Dechlorination of Environmental Contaminants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    De Corte, S.; Fitts, J.; Hennebel, T.

    2011-08-30

    Biologically produced monometallic palladium nanoparticles (bio-Pd) have been shown to catalyze the dehalogenation of environmental contaminants, but fail to efficiently catalyze the degradation of other important recalcitrant halogenated compounds. This study represents the first report of biologically produced bimetallic Pd/Au nanoparticle catalysts. The obtained catalysts were tested for the dechlorination of diclofenac and trichloroethylene. When aqueous bivalent Pd(II) and trivalent Au(III) ions were both added to concentrations of 50 mg L{sup -1} and reduced simultaneously by Shewanella oneidensis in the presence of H{sub 2}, the resulting cell-associated bimetallic nanoparticles (bio-Pd/Au) were able to dehalogenate 78% of the initially added diclofenacmore » after 24 h; in comparison, no dehalogenation was observed using monometallic bio-Pd or bio-Au. Other catalyst-synthesis strategies did not show improved dehalogenation of TCE and diclofenac compared with bio-Pd. Synchrotron-based X-ray diffraction, (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the simultaneous reduction of Pd and Au supported on cells of S. oneidensis resulted in the formation of a unique bimetallic crystalline structure. This study demonstrates that the catalytic activity and functionality of possibly environmentally more benign biosupported Pd-catalysts can be improved by coprecipitation with Au.« less

  9. Centrality Dependence of Charged Hadron Transverse Momentum Spectra in Au+Au Collisions from √(sNN)=62.4 to 200 GeV

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

    2005-03-01

    We have measured transverse momentum distributions of charged hadrons produced in Au+Au collisions at √(sNN)=62.4 GeV. The spectra are presented for transverse momenta 0.25Au+Au collisions at √(sNN)= 130 and 200 GeV. In contrast to the large change in RAA, we observe a very similar centrality evolution of the pT spectra at √(sNN)=62.4 and 200 GeV. The dynamical origin of this surprising factorization of energy and centrality dependence of particle production in heavy-ion collisions remains to be understood.

  10. Active control of methanol carbonylation selectivity over Au/carbon anode by electrochemical potential.

    PubMed

    Funakawa, Akiyasu; Yamanaka, Ichiro; Otsuka, Kiyoshi

    2005-05-12

    Electrochemical oxidative carbonylation of methanol was studied over Au supported carbon anode in CO. The major carbonylation products were dimethyl oxalate (DMO) and dimethyl carbonate (DMC). The minor oxidation products were dimethoxy methane (DMM) and methyl formate (MF) from methanol and CO(2). Influences of various reaction conditions were studied on carbonylation activities and selectivities. The selectivities to DMO and DMC can be controlled by the electrochemical potential. Electrocatalysis of Au/carbon anode was studied by cyclic voltammetry (CV), stoichiometric reactions among Au(3+), methanol, and CO, and UV-vis spectra. The Au/carbon anode was characterized by XRD, SEM, and BE images before and after the carbonylation. These experimental facts strongly suggest that transition of oxidation states of Au affects changing of the carbonylation selectivities to DMO and DMC. Au(0) is the active species for the selective DMO formation by direct electrochemical carbonylation at low potentials (<+1.2 V (Ag/AgCl)). On the other hand, Au(3+) is the active spices for the selective DMC formation by indirect electrochemical carbonylation through Au(3+)/Au(+) redox at high potentials (>+1.3 V).

  11. Enhanced catalyst activity by decorating of Au on Ag@Cu2O nanoshell

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Liu, Maomao; Zhao, Yue; Kou, Qiangwei; Wang, Yaxin; Liu, Yang; Zhang, Yongjun; Yang, Jinghai; Jung, Young Mee

    2018-03-01

    We successfully synthesized Au-decorated Ag@Cu2O heterostructures via a simple galvanic replacement method. As the Au precursor concentration increased, the density of the Au nanoparticles (NPs) on the Ag@Cu2O surface increased, which changed the catalytic activity of the Ag@Cu2O-Au structure. The combination of Au, Ag, and Cu2O exhibited excellent catalytic properties, which can further effect on the catalyst activity of the Ag@Cu2O-Au structure. In addition, the proposed Ag@Cu2O-Au nanocomposite was used to transform the organic, toxic pollutant, 4-nitrophenol (4-NP), into its nontoxic and medicinally important amino derivative via a catalytic reduction to optimize the material performance. The proposed Au-decorated Ag@Cu2O exhibited excellent catalytic activity, and the catalytic reduction time greatly decreased (5 min). Thus, three novel properties of Ag@Cu2O-Au, i.e., charge redistribution and transfer, adsorption, and catalytic reduction of organic pollutants, were ascertained for water remediation. The proposed catalytic properties have potential applications for photocatalysis and localized surface plasmon resonance (LSPR)- and peroxidase-like catalysis.

  12. Reduction of HAuCl 4 by Na 2S revisited: The case for Au nanoparticle aggregates and against Au 2S/Au core/shell particles

    DOE PAGES

    Schwartzberg, A. M.; Grant, C. D.; van Buuren, Tony; ...

    2007-03-10

    The reaction of sodium sulfide with chloroauric acid has been surrounded by a controversy over the structure of the resulting product. The original report proposed a Au 2S/Au core/shell structure based on strong near-IR resonance and limited transmission electron microscopy. Subsequent reports used the same model without further attempts to determine the structure of the products. With a significant body of experimental work compiled over a period of several years, we have shown that the major product of this reaction is aggregated spherical nanoparticles of gold with a minority component consisting of triangular and rod-like structures. This is in contradictionmore » to the core/shell structures as originally proposed. Recently, there have been additional reports that again suggest a Au 2S/Au core/shell structure or irregularly shaped Au nanoparticles as an explanation for the near-IR resonance. To help resolve this issue, we have carried out further experiments to determine how the reaction products may depend on experimental conditions such as concentration and aging of the reactants, particularly Na 2S. It has been determined that sodium thiosulfate is the likely product from Na 2S aging. In addition, persistent spectral hole burning experiments have been conducted on gold nanoparticle aggregate (GNA) samples at excitation intensities that are lower than that required to melt the nanostructures. We have observed a decrease in optical absorption on resonance with the excitation laser wavelength, with simultaneous increases in absorption to the blue and red of this wavelength region. However, in the presence of the stabilizer poly(vinyl pyrrolidone) (PVP), no increase in absorbance was observed but rather a blue shifting and decrease in intensity of the near-IR plasmon resonance. These results imply that the non-stabilized GNAs are able to break apart and reform into off resonant aggregate structures. In contrast, this behavior is suppressed in PVP stabilized

  13. Azimuthal Angle Dependence of HBT Radii in Au+Au Collisions at RHIC-PHENIX

    NASA Astrophysics Data System (ADS)

    Niida, Takafumi

    Measurement of Hanbury-Brown and Twiss (HBT) interferometry with respect to the event plane have been performed in Au+Au collisions at √{sNN} = 200 GeV at PHENIX, which is a unique tool to study the spatial extent of the created matter at final state in heavy ion collisions and the detailed picture of the space-time evolution from the initial state to the final state. The Gaussian source radii was measured for charged pions and kaons with respect to 2nd-order event plane. There was a difference in final eccentricity between both species, which may imply the different freeze-out mechanism by the particle species. The pion source radii was also measured relative to 3rd-order event plane, and the azimuthal angle dependence of the radii was observed, which qualitatively agrees with the recent hydrodynamic calculation and the oscillation may be driven from the triangular flow.

  14. Bendable solid-state supercapacitors with Au nanoparticle-embedded graphene hydrogel films

    PubMed Central

    Yang, Kyungwhan; Cho, Kyoungah; Yoon, Dae Sung; Kim, Sangsig

    2017-01-01

    In this study, we fabricate bendable solid-state supercapacitors with Au nanoparticle (NP)-embedded graphene hydrogel (GH) electrodes and investigate the influence of the Au NP embedment on the internal resistance and capacitive performance. Embedding the Au NPs into the GH electrodes results in a decrease of the internal resistance from 35 to 21 Ω, and a threefold reduction of the IR drop at a current density of 5 A/g when compared with GH electrodes without Au NPs. The Au NP-embedded GH supercapacitors (NP-GH SCs) exhibit excellent capacitive performances, with large specific capacitance (135 F/g) and high energy density (15.2 W·h/kg). Moreover, the NP-GH SCs exhibit comparable areal capacitance (168 mF/cm2) and operate under tensile/compressive bending. PMID:28074865

  15. Synthesis and electrocatalytic activity of Au/Pt bimetallic nanodendrites for ethanol oxidation in alkaline medium.

    PubMed

    Han, Xinyi; Wang, Dawei; Liu, Dong; Huang, Jianshe; You, Tianyan

    2012-02-01

    Gold/Platinum (Au/Pt) bimetallic nanodendrites were successfully synthesized through seeded growth method using preformed Au nanodendrites as seeds and ascorbic acid as reductant. Cyclic voltammograms (CVs) of a series of Au/Pt nanodendrites modified electrodes in 1M KOH solution containing 1M ethanol showed that the electrocatalyst with a molar ratio (Au:Pt) of 3 exhibited the highest peak current density and the lowest onset potential. The peak current density of ethanol electro-oxidation on the Au(3)Pt(1) nanodendrites modified glassy carbon electrode (Au(3)Pt(1) electrode) is about 16, 12.5, and 4.5 times higher than those on the polycrystalline Pt electrode, polycrystalline Au electrode, and Au nanodendrites modified glassy carbon electrode (Au dendrites electrode), respectively. The oxidation peak potential of ethanol electro-oxidation on the Au(3)Pt(1) electrode is about 299 and 276 mV lower than those on the polycrystalline Au electrode and Au dendrites electrode, respectively. These results demonstrated that the Au/Pt bimetallic nanodendrites may find potential application in alkaline direct ethanol fuel cells (ADEFCs). Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Facial expressions and speech acts: experimental evidences on the role of the upper face as an illocutionary force indicating device in language comprehension.

    PubMed

    Domaneschi, Filippo; Passarelli, Marcello; Chiorri, Carlo

    2017-08-01

    Language scientists have broadly addressed the problem of explaining how language users recognize the kind of speech act performed by a speaker uttering a sentence in a particular context. They have done so by investigating the role played by the illocutionary force indicating devices (IFIDs), i.e., all linguistic elements that indicate the illocutionary force of an utterance. The present work takes a first step in the direction of an experimental investigation of non-verbal IFIDs because it investigates the role played by facial expressions and, in particular, of upper-face action units (AUs) in the comprehension of three basic types of illocutionary force: assertions, questions, and orders. The results from a pilot experiment on production and two comprehension experiments showed that (1) certain upper-face AUs seem to constitute non-verbal signals that contribute to the understanding of the illocutionary force of questions and orders; (2) assertions are not expected to be marked by any upper-face AU; (3) some upper-face AUs can be associated, with different degrees of compatibility, with both questions and orders.

  17. Mecanismes de deformation de nanoparticules d'Au par irradiation ionique

    NASA Astrophysics Data System (ADS)

    Harkati Kerbouah, Chahineze

    2011-12-01

    In the present thesis, we study the anisotropic deformation of gold nanoparticles embedded in amorphous silica or crystalline aluminum arsenide, under ion bombardment. We try to comprehend the mechanism responsible for this deformation and to remove any ambiguity related to the explanation of this phenomenon. A hybrid process combining sputtering and plasma enhanced chemical vapour deposition was used to fabricate Au/SiO2 layers on fused silica substrates. Structures with single and multilayer were obtained. Heating during or after deposition activates the Au atom agglomeration and favours the growth of the nanoparticles. Also, a Au/AlAs nanocomposite was obtained by ion implantation of AlAs films, followed by rapid thermal annealing. The samples of the two nanocomposites, cooled with liquid nitrogen, were irradiated with 2 to 40 MeV Cu, Si, Au or In ion beams, at fluences ranging from 1x10 13 to 4x1015 ions/cm2, using a Tandem or Tandetron accelerator. The structural and morphological properties of the Au/SiO2 nanocomposite were extracted by optical means; the frequency and the width of surface plasmon resonance band depend on the nanoparticle shape and size, their concentration, the inter-particle distance and the dielectric properties of material in which the particles are embedded. The aluminum arsenide crystallinity was studied by two techniques: Raman spectroscopy and Rutherford backscattering spectrometry in channelling configuration (RBS/ channelling). The Au concentration in the nanocomposite layers was deducted from RBS results. The size distribution and metallic nanoparticles shape transformation in both nanocomposites were observed by electronic transmission microscopy. The results obtained within the framework of this work are the subject of three journal papers. The first publication shows the possibility of manipulating the width and spectral position of the gold nanoparticle absorption band in Au/SiO2 nanocomposites by modifying their structure

  18. Carbon-Type Analysis and Comparison of Original and Reblended FACE Diesel Fuels (FACE 2, FACE 4, and FACE 7)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bays, J. Timothy; King, David L.; O'Hagan, Molly J.

    This report summarizes the carbon-type analysis from 1H and 13C{1H} nuclear magnetic resonance spectroscopy (NMR) of Fuels for Advanced Combustion Engines (FACE) diesel blends, FD-2B, FD 4B, and FD-7B, and makes comparison of the new blends with the original FACE diesel blends, FD 2A, FD 4A, and FD-7A, respectively. Generally, FD-2A and FD-2B are more similar than the A and B blends of FD-4 and FD-7. The aromatic carbon content is roughly equivalent, although the new FACE blends have decreased monoaromatic content and increased di- and tri-cycloaromatic content, as well as a higher overall aromatic content, than the original FACEmore » blends. The aromatic components of the new FACE blends generally have a higher alkyl substitution with longer alkyl substituents. The naphthenic and paraffinic contents remained relatively consistent. Based on aliphatic methyl and methylene carbon ratios, cetane numbers for FD-2A and -2B, and FD-7A and -7B are predicted to be consistent, while the cetane number for FD-4B is predicted to be higher than FD-4A. Overall, the new FACE fuel blends are fairly consistent with the original FACE fuel blends, but there are observable differences. In addition to providing important comparative compositional information on reformulated FACE diesel blends, this report also provides important information about the capabilities of the team at Pacific Northwest National Laboratory in the use of NMR spectroscopy for the detailed characterization and comparison of fuels and fuel blends.« less

  19. Kinetically controlled synthesis of Au102(SPh)44 nanoclusters and catalytic application.

    PubMed

    Chen, Yongdong; Wang, Jin; Liu, Chao; Li, Zhimin; Li, Gao

    2016-05-21

    We here explore a kinetically controlled synthetic protocol for preparing solvent-solvable Au102(SPh)44 nanoclusters which are isolated from polydispersed gold nanoclusters by solvent extraction and size exclusion chromatography (SEC). The as-obtained Au102(SPh)44 nanoclusters are determined by matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometry, in conjunction with UV-vis spectroscopy and thermogravimetric analysis (TGA). However, Au99(SPh)42, instead of Au102(SPh)44, is yielded when the polydispersed gold nanoclusters are etched in the presence of excess thiophenol under thermal conditions (e.g., 80 °C). Interestingly, the Au102(SPh)44 nanoclusters also can convert to Au99(SPh)42 with equivalent thiophenol ligands, evidenced by the analyses of UV-vis and MALDI mass spectrometry. Finally, the TiO2-supported Au102(SPh)44 nanocluster catalyst is investigated in the selective oxidation of sulfides into sulfoxides by the PhIO oxidant and gives rise to high catalytic activity (e.g., 80-99% conversion of R-S-R' sulfides with 96-99% selectivity for R-S([double bond, length as m-dash]O)-R' sulfoxides). The Au102(SPh)44/TiO2 catalyst also shows excellent recyclability in the sulfoxidation process.

  20. Au Nanoparticle Sub-Monolayers Sandwiched between Sol-Gel Oxide Thin Films

    PubMed Central

    Della Gaspera, Enrico; Menin, Enrico; Sada, Cinzia

    2018-01-01

    Sub-monolayers of monodisperse Au colloids with different surface coverage have been embedded in between two different metal oxide thin films, combining sol-gel depositions and proper substrates functionalization processes. The synthetized films were TiO2, ZnO, and NiO. X-ray diffraction shows the crystallinity of all the oxides and verifies the nominal surface coverage of Au colloids. The surface plasmon resonance (SPR) of the metal nanoparticles is affected by both bottom and top oxides: in fact, the SPR peak of Au that is sandwiched between two different oxides is centered between the SPR frequencies of Au sub-monolayers covered with only one oxide, suggesting that Au colloids effectively lay in between the two oxide layers. The desired organization of Au nanoparticles and the morphological structure of the prepared multi-layered structures has been confirmed by Rutherford backscattering spectrometry (RBS), Secondary Ion Mass Spectrometry (SIMS), and Scanning Electron Microscopy (SEM) analyses that show a high quality sandwich structure. The multi-layered structures have been also tested as optical gas sensors. PMID:29538338

  1. Au36(SePh)24 nanomolecules: synthesis, optical spectroscopy and theoretical analysis.

    PubMed

    Rambukwella, Milan; Chang, Le; Ravishanker, Anish; Fortunelli, Alessandro; Stener, Mauro; Dass, Amala

    2018-05-16

    Here, we report the synthesis of selenophenol (HSePh) protected Au36(SePh)24 nanomolecules via a ligand-exchange reaction of 4-tert-butylbenzenethiol (HSPh-tBu) protected Au36(SPh-tBu)24 with selenophenol, and its spectroscopic and theoretical analysis. Matrix assisted laser desorption ionization (MALDI) mass spectrometry, electrospray ionization (ESI) mass spectrometry and optical characterization confirm that the composition of the as synthesized product is predominantly Au36(SePh)24 nanomolecules. Size exclusion chromatography (SEC) was employed to isolate the Au36(SePh)24 and temperature dependent optical absorption studies and theoretical analysis were performed. Theoretically, an Independent Component Maps of Oscillator Strength (ICM-OS) analysis of simulated spectra shows that the enhancement in absorption intensity in Au36(SePh)24 with respect to Au36(SPh)24 can be ascribed to the absence of interference and/or increased long-range coupling between interband metal core and ligand excitations. This work demonstrates and helps to understand the effect of Au-Se bridging on the properties of gold nanomolecules.

  2. Au nanoparticles films used in biological sensing

    NASA Astrophysics Data System (ADS)

    Rosales Pérez, M.; Delgado Macuil, R.; Rojas López, M.; Gayou, V. L.; Sánchez Ramírez, J. F.

    2009-05-01

    Lactobacillus para paracasei are used commonly as functional food and probiotic substances. In this work Au nanoparticles self-assembled films were used for Lactobacillus para paracasei determination at five different concentrations. Functionalized substrates were immersed in a colloidal solution for one and a half hour at room temperature and dried at room temperature during four hours. After that, drops of Lactobacillus para paracasei in aqueous solution were put into the Au nanoparticles film and let dry at room temperature for another two hours. Infrared spectroscopy in attenuated total reflectance sampling mode was used to observe generation peaks due to substrate silanization, enhancement of Si-O band intensity due to the Au colloids added to silanized substrate and also to observe the enhancement of Lactobacillus para paracasei infrared intensity of the characteristic frequencies at 1650, 1534 and 1450 cm-1 due to surface enhancement infrared absorption.

  3. An investigation of enhanced secondary ion emission under Au(n)+ (n = 1-7) bombardment.

    PubMed

    Nagy, G; Gelb, L D; Walker, A V

    2005-05-01

    We investigate the mechanism of the nonlinear secondary ion yield enhancement using Au(n)+ (n = 1, 2, 3, 5, 7) primary ions bombarding thin films of Irganox 1010, DL-phenylalanine and polystyrene on Si, Al, and Ag substrates. The largest differences in secondary ion yields are found using Au+, Au2+, and Au3+ primary ion beams. A smaller increase in secondary ion yield is observed using Au5+ and Au7+ primary ions. The yield enhancement is found to be larger on Si than on Al, while the ion yield is smaller using an Au+ beam on Si than on Al. Using Au(n)+ ion structures obtained from Density Functional Theory, we demonstrate that the secondary yield enhancement is not simply due to an increase in energy per area deposited into the surface (energy deposition density). Instead, based on simple mechanical arguments and molecular dynamics results from Medvedeva et al, we suggest a mechanism for nonlinear secondary ion yield enhancement wherein the action of multiple concerted Au impacts leads to efficient energy transfer to substrate atoms in the near surface region and an increase in the number of secondary ions ejected from the surface. Such concerted impacts involve one, two, or three Au atoms, which explains well the large nonlinear yield enhancements observed going from Au+ to Au2+ to Au3+ primary ions. This model is also able to explain the observed substrate effect. For an Au+ ion passing through the more open Si surface, it contacts fewer substrate atoms than in the more dense Al surface. Less energy is deposited in the Si surface region by the Au+ primary ion and the secondary ion yield will be lower for adsorbates on Si than on Al. In the case of Au(n)+ the greater density of Al leads to earlier break-up of the primary ion and a consequent reduction in energy transfer to the near-surface region when compared with Si. This results in higher secondary ion yields and yield enhancements on silicon than aluminum substrates.

  4. Vapochromic Behaviour of M[Au(CN)2]2-Based Coordination Polymers (M = Co, Ni)

    PubMed Central

    Lefebvre, Julie; Korčok, Jasmine L.; Katz, Michael J.; Leznoff, Daniel B.

    2012-01-01

    A series of M[Au(CN)2]2(analyte)x coordination polymers (M = Co, Ni; analyte = dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), pyridine; x = 2 or 4) was prepared and characterized. Addition of analyte vapours to solid M(μ-OH2)[Au(CN)2]2 yielded visible vapochromic responses for M = Co but not M = Ni; the IR νCN spectral region changed in every case. A single crystal structure of Zn[Au(CN)2]2(DMSO)2 revealed a corrugated 2-D layer structure with cis-DMSO units. Reacting a Ni(II) salt and K[Au(CN)2] in DMSO yielded the isostructural Ni[Au(CN)2]2(DMSO)2 product. Co[Au(CN)2]2(DMSO)2 and M[Au(CN)2]2(DMF)2 (M = Co, Ni) complexes have flat 2-D square-grid layer structures with trans-bound DMSO or DMF units; they are formed via vapour absorption by solid M(μ-OH2)[Au(CN)2]2 and from DMSO or DMF solution synthesis. Co[Au(CN)2]2(pyridine)4 is generated via vapour absorption by Co(μ-OH2)[Au(CN)2]2; the analogous Ni complex is synthesized by immersion of Ni(μ-OH2)[Au(CN)2]2 in 4% aqueous pyridine. Similar immersion of Co(μ-OH2)[Au(CN)2]2 yielded Co[Au(CN)2]2(pyridine)2, which has a flat 2-D square-grid structure with trans-pyridine units. Absorption of pyridine vapour by solid Ni(μ-OH2)[Au(CN)2]2 was incomplete, generating a mixture of pyridine-bound complexes. Analyte-free Co[Au(CN)2]2 was prepared by dehydration of Co(μ-OH2)[Au(CN)2]2 at 145 °C; it has a 3-D diamondoid-type structure and absorbs DMSO, DMF and pyridine to give the same materials as by vapour absorption from the hydrate. PMID:22737031

  5. Face-to-face or face-to-screen? Undergraduates' opinions and test performance in classroom vs. online learning

    PubMed Central

    Kemp, Nenagh; Grieve, Rachel

    2014-01-01

    As electronic communication becomes increasingly common, and as students juggle study, work, and family life, many universities are offering their students more flexible learning opportunities. Classes once delivered face-to-face are often replaced by online activities and discussions. However, there is little research comparing students' experience and learning in these two modalities. The aim of this study was to compare undergraduates' preference for, and academic performance on, class material and assessment presented online vs. in traditional classrooms. Psychology students (N = 67) at an Australian university completed written exercises, a class discussion, and a written test on two academic topics. The activities for one topic were conducted face-to-face, and the other online, with topics counterbalanced across two groups. The results showed that students preferred to complete activities face-to-face rather than online, but there was no significant difference in their test performance in the two modalities. In their written responses, students expressed a strong preference for class discussions to be conducted face-to-face, reporting that they felt more engaged, and received more immediate feedback, than in online discussion. A follow-up study with a separate group (N = 37) confirmed that although students appreciated the convenience of completing written activities online in their own time, they also strongly preferred to discuss course content with peers in the classroom rather than online. It is concluded that online and face-to-face activities can lead to similar levels of academic performance, but that students would rather do written activities online but engage in discussion in person. Course developers could aim to structure classes so that students can benefit from both the flexibility of online learning, and the greater engagement experienced in face-to-face discussion. PMID:25429276

  6. Face-to-face or face-to-screen? Undergraduates' opinions and test performance in classroom vs. online learning.

    PubMed

    Kemp, Nenagh; Grieve, Rachel

    2014-01-01

    As electronic communication becomes increasingly common, and as students juggle study, work, and family life, many universities are offering their students more flexible learning opportunities. Classes once delivered face-to-face are often replaced by online activities and discussions. However, there is little research comparing students' experience and learning in these two modalities. The aim of this study was to compare undergraduates' preference for, and academic performance on, class material and assessment presented online vs. in traditional classrooms. Psychology students (N = 67) at an Australian university completed written exercises, a class discussion, and a written test on two academic topics. The activities for one topic were conducted face-to-face, and the other online, with topics counterbalanced across two groups. The results showed that students preferred to complete activities face-to-face rather than online, but there was no significant difference in their test performance in the two modalities. In their written responses, students expressed a strong preference for class discussions to be conducted face-to-face, reporting that they felt more engaged, and received more immediate feedback, than in online discussion. A follow-up study with a separate group (N = 37) confirmed that although students appreciated the convenience of completing written activities online in their own time, they also strongly preferred to discuss course content with peers in the classroom rather than online. It is concluded that online and face-to-face activities can lead to similar levels of academic performance, but that students would rather do written activities online but engage in discussion in person. Course developers could aim to structure classes so that students can benefit from both the flexibility of online learning, and the greater engagement experienced in face-to-face discussion.

  7. Structural, (197)Au Mössbauer and solid state (31)P CP/MAS NMR studies on bis (cis-bis(diphenylphosphino)ethylene) gold(I) complexes [Au(dppey)(2)]X for X = PF(6), I.

    PubMed

    Healy, Peter C; Loughrey, Bradley T; Bowmaker, Graham A; Hanna, John V

    2008-07-28

    (197)Au Mössbauer spectra for the d(10) gold(i) phosphine complexes, [Au(dppey)(2)]X (X = PF(6), I; dppey = (cis-bis(diphenylphosphino)ethylene), and the single crystal X-ray structure and solid state (31)P CPMAS NMR spectrum of [Au(dppey)(2)]I are reported here. In [Au(dppey)(2)]I the AuP(4) coordination geometry is distorted from the approximately D(2) symmetry observed for the PF(6)(-) complex with Au-P bond lengths 2.380(2)-2.426(2) A and inter-ligand P-Au-P angles 110.63(5)-137.71(8) degrees . Quadrupole splitting parameters derived from the Mössbauer spectra are consistent with the increased distortion of the AuP(4) coordination sphere with values of 1.22 and 1.46 mm s(-1) for the PF(6)(-) and I(-) complexes respectively. In the solid state (31)P CP MAS NMR spectrum of [Au(dppey)(2)]I, signals for each of the four crystallographically independent phosphorus nuclei are observed, with the magnitude of the (197)Au quadrupole coupling being sufficiently large to produce a collapse of (1)J(Au-P) splitting from quartets to doublets. The results highlight the important role played by the counter anion in the determination of the structural and spectroscopic properties of these sterically crowded d(10) complexes.

  8. Mapping Teacher-Faces

    ERIC Educational Resources Information Center

    Thompson, Greg; Cook, Ian

    2013-01-01

    This paper uses Deleuze and Guattari's concept of faciality to analyse the teacher's face. According to Deleuze and Guattari, the teacher-face is a special type of face because it is an "overcoded" face produced in specific landscapes. This paper suggests four limit-faces for teacher faciality that actualise different mixes of significance and…

  9. [Congenital "kissing" lesions: Nevus or "café au lait" spot?

    PubMed

    Durazzo, A; Boccara, O; Fraitag, S; Fusade, T; Picard, A; Kadlub, N

    2016-12-01

    "Café au lait" spots (CLS) are pigmented skin lesions principally located at the trunk and the limbs. Histologically, CLSs consist in an excessive pigmentation of the epidermis, with no risk of malignant transformation. The "kissing" nevus is a rare pigmented congenital nevus affecting both lower and upper eyelids in a mirror layout. As other nevi, it presents a theoretical risk of malignant transformation. These two pigmented lesions are responsible for aesthetic discomfort when affecting the face. Three patients presenting with a congenital pigmented lesion affecting the two eyelids in a mirror layout are presented. In two cases, the lesions, initially considered as "kissing" nevi, were classified as CLSs. The diagnosis of CLS was made on a biopsy in one patient and after surgery in the other one. Pigmented mirror layout lesions, called "kissing" lesions, are exclusively described for the nevi. We describe two cases of CLSs affecting the eyelids in a mirror layout. Difficulties in diagnostic are exposed and the possible treatments are discussed. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Efficient Removal of Methane over Cobalt-Monoxide-Doped AuPd Nanocatalysts.

    PubMed

    Xie, Shaohua; Liu, Yuxi; Deng, Jiguang; Zang, Simiao; Zhang, Zhenhua; Arandiyan, Hamidreza; Dai, Hongxing

    2017-02-21

    To overcome deactivation of Pd-based catalysts at high temperatures, we herein design a novel pathway by introducing a certain amount of CoO to the supported Au-Pd alloy nanoparticles (NPs) to generate high-performance Au-Pd-xCoO/three-dimensionally ordered macroporous (3DOM) Co 3 O 4 (x is the Co/Pd molar ratio) catalysts. The doping of CoO induced the formation of PdO-CoO active sites, which was beneficial for the improvement in adsorption and activation of CH 4 and catalytic performance. The Au-Pd-0.40CoO/3DOM Co 3 O 4 sample performed the best (T 90% = 341 °C at a space velocity of 20 000 mL g -1 h -1 ). Deactivation of the 3DOM Co 3 O 4 -supported Au-Pd, Pd-CoO, and Au-Pd-xCoO nanocatalysts resulting from water vapor addition was due to the formation and accumulation of hydroxyl on the catalyst surface, whereas deactivation of the Pd-CoO/3DOM Co 3 O 4 catalyst at high temperatures (680-800 °C) might be due to decomposition of the PdO y active phase into aggregated Pd 0 NPs. The Au-Pd-xCoO/3DOM Co 3 O 4 nanocatalysts exhibited better thermal stability and water tolerance ability compared to the 3DOM Co 3 O 4 -supported Au-Pd and Pd-CoO nanocatalysts. We believe that the supported Au-Pd-xCoO nanomaterials are promising catalysts in practical applications for organic combustion.

  11. Faces forming traces: neurophysiological correlates of learning naturally distinctive and caricatured faces.

    PubMed

    Schulz, Claudia; Kaufmann, Jürgen M; Kurt, Alexander; Schweinberger, Stefan R

    2012-10-15

    Distinctive faces are easier to learn and recognise than typical faces. We investigated effects of natural vs. artificial distinctiveness on performance and neural correlates of face learning. Spatial caricatures of initially non-distinctive faces were created such that their rated distinctiveness matched a set of naturally distinctive faces. During learning, we presented naturally distinctive, caricatured, and non-distinctive faces for later recognition among novel faces, using different images of the same identities at learning and test. For learned faces, an advantage in performance was observed for naturally distinctive and caricatured over non-distinctive faces, with larger benefits for naturally distinctive faces. Distinctive and caricatured faces elicited more negative occipitotemporal ERPs (P200, N250) and larger centroparietal positivity (LPC) during learning. At test, earliest distinctiveness effects were again seen in the P200. In line with recent research, N250 and LPC were larger for learned than for novel faces overall. Importantly, whereas left hemispheric N250 was increased for learned naturally distinctive faces, right hemispheric N250 responded particularly to caricatured novel faces. We conclude that natural distinctiveness induces benefits to face recognition beyond those induced by exaggeration of a face's idiosyncratic shape, and that the left hemisphere in particular may mediate recognition across different images. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Mapping attractor fields in face space: the atypicality bias in face recognition.

    PubMed

    Tanaka, J; Giles, M; Kremen, S; Simon, V

    1998-09-01

    A familiar face can be recognized across many changes in the stimulus input. In this research, the many-to-one mapping of face stimuli to a single face memory is referred to as a face memory's 'attractor field'. According to the attractor field approach, a face memory will be activated by any stimuli falling within the boundaries of its attractor field. It was predicted that by virtue of its location in a multi-dimensional face space, the attractor field of an atypical face will be larger than the attractor field of a typical face. To test this prediction, subjects make likeness judgments to morphed faces that contained a 50/50 contribution from an atypical and a typical parent face. The main result of four experiments was that the morph face was judged to bear a stronger resemblance to the atypical face parent than the typical face parent. The computational basis of the atypicality bias was demonstrated in a neural network simulation where morph inputs of atypical and typical representations elicited stronger activation of atypical output units than of typical output units. Together, the behavioral and simulation evidence supports the view that the attractor fields of atypical faces span over a broader region of face space that the attractor fields of typical faces.

  13. Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Qiu, Haodong; Wang, Hong, E-mail: ewanghong@ntu.edu.sg; Ke, Feixiang

    The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

  14. Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

    NASA Astrophysics Data System (ADS)

    Qiu, Haodong; Wang, Hong; Ke, Feixiang

    2014-06-01

    The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

  15. Gigantic transverse x-ray magnetic circular dichroism in ultrathin Co in Au/Co/Au(001)

    NASA Astrophysics Data System (ADS)

    Koide, T.; Mamiya, K.; Asakura, D.; Osatune, Y.; Fujimori, A.; Suzuki, Y.; Katayama, T.; Yuasa, S.

    2014-04-01

    Transverse-geometry x-ray magnetic circular dichroism (TXMCD) measurements on Au/Co-staircase/Au(001) reveal the orbital origin of intrinsic in-plane magnetic anisotropy A gigantic TXMCD was successfully observed at the Co L3,2 edges for Co thickness (tC0) in the 2-monolayer regime. A TXMCD-sum-rule analysis shows a remarkable enhancement of an orbital-moment anisotropy (Δmorb) and of an in-plane magnetic dipole moment (m||T). Both Δmorb and m||T exhibit close similarity in tCo dependence, reflecting the in-plane magnetic anisotropy These observations evidence that extremely strong, intrinsic, in-plane magnetic anisotropy originates from the anisotropic orbital part of the wave function, dominating the dipole-dipole-interaction-derived, extrinsic, in-plane magnetic anisotropy.

  16. Effectiveness of link prediction for face-to-face behavioral networks.

    PubMed

    Tsugawa, Sho; Ohsaki, Hiroyuki

    2013-01-01

    Research on link prediction for social networks has been actively pursued. In link prediction for a given social network obtained from time-windowed observation, new link formation in the network is predicted from the topology of the obtained network. In contrast, recent advances in sensing technology have made it possible to obtain face-to-face behavioral networks, which are social networks representing face-to-face interactions among people. However, the effectiveness of link prediction techniques for face-to-face behavioral networks has not yet been explored in depth. To clarify this point, here we investigate the accuracy of conventional link prediction techniques for networks obtained from the history of face-to-face interactions among participants at an academic conference. Our findings were (1) that conventional link prediction techniques predict new link formation with a precision of 0.30-0.45 and a recall of 0.10-0.20, (2) that prolonged observation of social networks often degrades the prediction accuracy, (3) that the proposed decaying weight method leads to higher prediction accuracy than can be achieved by observing all records of communication and simply using them unmodified, and (4) that the prediction accuracy for face-to-face behavioral networks is relatively high compared to that for non-social networks, but not as high as for other types of social networks.

  17. Effectiveness of Link Prediction for Face-to-Face Behavioral Networks

    PubMed Central

    Tsugawa, Sho; Ohsaki, Hiroyuki

    2013-01-01

    Research on link prediction for social networks has been actively pursued. In link prediction for a given social network obtained from time-windowed observation, new link formation in the network is predicted from the topology of the obtained network. In contrast, recent advances in sensing technology have made it possible to obtain face-to-face behavioral networks, which are social networks representing face-to-face interactions among people. However, the effectiveness of link prediction techniques for face-to-face behavioral networks has not yet been explored in depth. To clarify this point, here we investigate the accuracy of conventional link prediction techniques for networks obtained from the history of face-to-face interactions among participants at an academic conference. Our findings were (1) that conventional link prediction techniques predict new link formation with a precision of 0.30–0.45 and a recall of 0.10–0.20, (2) that prolonged observation of social networks often degrades the prediction accuracy, (3) that the proposed decaying weight method leads to higher prediction accuracy than can be achieved by observing all records of communication and simply using them unmodified, and (4) that the prediction accuracy for face-to-face behavioral networks is relatively high compared to that for non-social networks, but not as high as for other types of social networks. PMID:24339956

  18. Architecture effects of glucose oxidase/Au nanoparticle composite Langmuir-Blodgett films on glucose sensing performance

    NASA Astrophysics Data System (ADS)

    Wang, Ke-Hsuan; Wu, Jau-Yann; Chen, Liang-Huei; Lee, Yuh-Lang

    2016-03-01

    The Langmuir-Blodgett (LB) deposition technique is employed to prepare nano-composite films consisting of glucose oxidase (GOx) and gold nanoparticles (AuNPs) for glucose sensing applications. The GOx and AuNPs are co-adsorbed from an aqueous solution onto an air/liquid interface in the presence of an octadecylamine (ODA) template monolayer, forming a mixed (GOx-AuNP) monolayer. Alternatively, a composite film with a cascade architecture (AuNP/GOx) is also prepared by sequentially depositing monolayers of AuNPs and GOx. The architecture effects of the composite LB films on the glucose sensing are studied. The results show that the presence of AuNPs in the co-adsorption system does not affect the adsorption amount and preferred conformation (α-helix) of GOx. Furthermore, the incorporation of AuNPs in both composite films can significantly improve the sensing performance. However, the enhancement effects of the AuNPs in the two architectures are distinct. The major effect of the AuNPs is on the facilitation of charge-transfer in the (GOx-AuNP) film, but on the increase of catalytic activity in the (AuNP/GOx) one. Therefore, the sensing performance can be greatly improved by utilizing a film combining both architectures (AuNP/GOx-AuNP).

  19. Sidération myocardique au cours d'une intoxication au monoxyde de carbone (CO) chez une femme enceinte

    PubMed Central

    Coulibaly, Mahamadoun; Berdai, Mohamed Adnane; Labib, Smael; Harandou, Mustapha

    2015-01-01

    L'intoxication au monoxyde de carbone (CO) est la première cause de décès par intoxication en France. La littérature est ancienne et peu connue. Les signes les plus fréquents de l'intoxication sont la triade: Céphalées; asthénie, faiblesse musculaire surtout des membres inférieurs. Ses conséquences sont potentiellement graves pour le fœtus quand elle survient chez la femme enceinte, il est particulièrement exposé au risque d'hypoxie en raison de la forte affinité de son hémoglobine pour le CO qui traverse aisément le placenta. Les événements cardiovasculaires ne sont pas rares et peuvent être responsable d'une morbi-mortalité assez importante qui peuvent être d'apparition rapide ou secondaire mais régressent habituellement en quelques jours. Des SCA peuvent survenir lors d'une une intoxication au CO avec à l'extrême infarctus myocardique avec surélévation du segment ST. Il paraît légitime de proposer pour toutes les patientes: l’éloignement maternel de la source de CO; l'oxygénothérapie à 100% au masque facial par les services de secours et pendant le transfert; le traitement par oxygénothérapie hyperbare pour toutes les femmes enceintes, le plus rapidement possible et quelque soit l’âge gestationnel. PMID:26405502

  20. Long Term Measurement of the Vapor Pressure of Gold in the Au-C System

    NASA Technical Reports Server (NTRS)

    Copland, Evan H.

    2009-01-01

    Incorporating the {Au(s,l) + graphite} reference in component activity measurements made with the multiple effusion-cell vapor source mass spectrometry (multicell KEMS) technique provides a fixed temperature defining ITS-90 (T(sub mp)(Au) = 1337.33K) and a systematic method to check accuracy. Over a 2 year period delta H sub(298)Au was determined by the 2nd and 3rd law methods in 25 separate experiments and were in the ranges 362.2 plus or minus 3.3 kJmol(sup -1) and 367.8 plus or minus 1.1 kJmol(sup -1), respectively. This 5 kJmol-1 discrepancy is transferred directly to the measured activities. This is unacceptable and the source of this discrepancy needs to be understood and corrected. Accepting the 2nd law value increases p(Au) by about 50 percent, brings the 2nd and 3rd law values into agreement and removes the T dependence in the 3rd law values. While compelling, there is no way to independently determine instrument sensitivities, S(sub Au), with T in a single experiment with KEMS. This lack of capability is stopping a deeper understanding of this problem. In addition, the Au-C phase diagram suggests a eutectic invariant reaction: L-Au(4.7at%C) = FCC-Au(0.08at%C) + C(graphite) at T(sub e) approximately 1323K. This high C concentration in Au(l) must reduce p(Au) in equilibrium with {Au(s,l) + graphite} and raises some critical questions about the Gibbs free energy functions of Au(s,l) and the Au fixed point (T(sub mp)(Au) = 1337.33K) which is always measured in graphite.