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Sample records for monoclinic unit cells

  1. Monoclinic deformation of calcite crystals at ambient conditions

    Science.gov (United States)

    Przeniosło, R.; Fabrykiewicz, P.; Sosnowska, I.

    2016-09-01

    High resolution synchrotron radiation powder diffraction shows that the average crystal structure of calcite at ambient conditions is described with the trigonal space group R 3 bar c but there is a systematic hkl-dependent Bragg peak broadening. A modelling of this anisotropic peak broadening with the microstrain model from Stephens (1999) [15] is presented. The observed lattice parameters' correlations can be described by assuming a monoclinic-type deformation of calcite crystallites. A quantitative model of this monoclinic deformation observed at ambient conditions is described with the space group C 2 / c . The monoclinic unit cell suggested at ambient conditions is related with the monoclinic unit cell reported in calcite at high pressure (Merrill and Bassett (1975) [10]).

  2. Bi-Cell Unit for Fuel Cell.

    Science.gov (United States)

    The patent concerns a bi-cell unit for a fuel cell . The bi-cell unit is comprised of two electrode packs. Each of the electrode packs includes an...invention relates in general to a bi-cell unit for a fuel cell and in particular, to a bi-cell unit for a hydrazine-air fuel cell .

  3. Sickle Cell Unit.

    Science.gov (United States)

    Canipe, Stephen L.

    Included in this high school biology unit on sickle cell anemia are the following materials: a synopsis of the history of the discovery and the genetic qualities of the disease; electrophoresis diagrams comparing normal, homozygous and heterozygous conditions of the disease; and biochemical characteristics and population genetics of the disease. A…

  4. The giant piezoelectric effect: electric field induced monoclinic phase or piezoelectric distortion of the rhombohedral parent?

    CERN Document Server

    Kisi, E H; Forrester, J S; Howard, C J

    2003-01-01

    Lead zinc niobate-lead titanate (PZN-PT) single crystals show very large piezoelectric strains for electric fields applied along the unit cell edges e.g. [001] sub R. It has been widely reported that this effect is caused by an electric field induced phase transition from rhombohedral (R3m) to monoclinic (Cm or Pm) symmetry in an essentially continuous manner. Group theoretical analysis using the computer program ISOTROPY indicates phase transitions between R3m and Cm (or Pm) must be discontinuous under Landau theory. An analysis of the symmetry of a strained unit cell in R3m and a simple expansion of the piezoelectric strain equation indicate that the piezoelectric distortion due to an electric field along a cell edge in rhombohedral perovskite-based ferroelectrics is intrinsically monoclinic (Cm), even for infinitesimal electric fields. PZN-PT crystals have up to nine times the elastic compliance of other piezoelectric perovskites and it might be expected that the piezoelectric strains are also very large. ...

  5. Influence of downsizing of zeolite crystals on the orthorhombic ↔ monoclinic phase transition in pure silica MFI-type

    Science.gov (United States)

    Kabalan, Ihab; Michelin, Laure; Rigolet, Séverinne; Marichal, Claire; Daou, T. Jean; Lebeau, Bénédicte; Paillaud, Jean-Louis

    2016-08-01

    The impact of crystal size on the transition orthorhombic ↔ monoclinic phase in MFI-type purely silica zeolites is investigated between 293 and 473 K using 29Si MAS NMR and powder X-ray diffraction. Three silicalite-1 zeolites are synthesized: a material constituted of micron-sized crystals, pseudospherical nanometer-sized crystals and hierarchical porous zeolites with a mesoporous network created by the use of a gemini-type diquaternary ammonium surfactant giving nanosheet zeolites. Our results show for the first time that the orthorhombic ↔ monoclinic phase transition already known for micron-sized particles also occurs in nanometer-sized zeolite crystals whereas our data suggest that the extreme downsizing of the zeolite crystal to one unit cell in thickness leads to an extinction of the phase transition.

  6. Synthesis of monoclinic zinc diphosphide single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Mowles, T.A.

    1978-05-01

    Monoclinic zinc diphosphide is a cheap, plentiful, direct-gap semiconductor with an optimum transition energy for solar absorption. Single crystals were grown from the vapor to be evaluated as a new photovoltaic material. Monoclinic and tetragonal crystal formed within evacuated quartz ampules that were charged with zinc and excess phosphorous and heated in a temperature gradient to give phosphorous pressures from 0.07 to 8.5 atmospheres. The monoclinic form melts incongruently near 990/sup 0/C. The tetragonal form is metastable; its growth is enhanced by impurities but retarded by high phosphorous pressures. The mechanism of the synthesis indicates that a tightly-controlled vapor deposition is possible and that high-quality thin films should form at temperatures from 950 to 990/sup 0/C at pressures below 10 atmospheres. By a modification of the technique, sesquizinc phosphide single crystals were grown for comparison.

  7. Monoclinic polymorph of poly[aqua(μ4-hydrogen tartratosodium

    Directory of Open Access Journals (Sweden)

    Mohammad T. M. Al-Dajani

    2010-02-01

    Full Text Available A monoclinic polymorph of the title compound, [Na(C4H5O6(H2O]n, is reported and complements an orthorhombic form [Kubozono, Hirano, Nagasawa, Maeda & Kashino (1993. Bull. Chem. Soc. Jpn, 66, 2166–2173]. The asymmetric unit contains a hydrogen tartrate anion, an Na+ cation and a water molecule. The Na+ ion is surrounded by seven O atoms derived from one independent and three symmetry-related hydrogen tartrate anions, and a water molecule, forming a distorted pentagonal–bipyramidal geometry. Independent units are linked via a pair of intermolecular bifurcated O—H...O acceptor bonds, generating an R21(6 ring motif to form polymeric two-dimensional arrays parallel to the (100 plane. In the crystal packing, the arrays are linked by adjacent ring motifs, together with additional intermolecular O—H...O interactions, into a three-dimensional network.

  8. Unit: Cells, Inspection Set, National Trial Print.

    Science.gov (United States)

    Australian Science Education Project, Toorak, Victoria.

    This trial version of a unit is the series being produced by the Australian Science Education Project provides instructions for students to prepare a variety of cell types and examine them with microscopes. It also gives some information about the variety and function of cells. The core of the unit, which all students are expected to complete,…

  9. 2-(4-Fluorobenzylidenepropanedinitrile: monoclinic polymorph

    Directory of Open Access Journals (Sweden)

    Ahmed M. El-Agrody

    2013-04-01

    Full Text Available The title compound, C10H5FN2, is a monoclinic (P21/c polymorph of the previously reported triclinic (P-1 form [Antipin et al. (2003. J. Mol. Struct. 650, 1–20]. The 13 non-H atoms in the title polymorph are almost coplanar (r.m.s. deviation = 0.020 Å; a small twist between the fluorobenzene and dinitrile groups [C—C—C—C torsion angle = 175.49 (16°] is evident in the triclinic polymorph. In the crystal, C—H...N interactions lead to supramolecular layers parallel to (-101; these are connected by C—F...π interactions.

  10. Monoclinic zirconia distributions in plasma-sprayed thermal barrier coatings

    Science.gov (United States)

    Lance, M. J.; Haynes, J. A.; Ferber, M. K.; Cannon, W. R.

    2000-03-01

    Phase composition in an air plasma-sprayed Y2O3-stabilized ZrO2 (YSZ) top coating of a thermal barrier coating (TBC) system was characterized. Both the bulk phase content and localized pockets of monoclinic zirconia were measured with Raman spectroscopy. The starting powder consisted of ˜15 vol.% monoclinic zirconia, which decreased to ˜2 vol.% in the as-sprayed coating. Monoclinic zirconia was concentrated in porous pockets that were evenly distributed throughout the TBC. The pockets resulted from the presence of unmelted granules in the starting powder. The potential effect of the distributed monoclinic pockets on TBC performance is discussed.

  11. Microstructure, bioactivity and osteoblast behavior of monoclinic zirconia coating with nanostructured surface.

    Science.gov (United States)

    Wang, Guocheng; Meng, Fanhao; Ding, Chuanxian; Chu, Paul K; Liu, Xuanyong

    2010-03-01

    A monoclinic zirconia coating with a nanostructural surface was prepared on the Ti-6Al-4V substrate by an atmospheric plasma-spraying technique, and its microstructure and composition, as well as mechanical and biological properties, were investigated to explore potential application as a bioactive coating on bone implants. X-ray diffraction, transmission electron microscopy, scanning electron microscopy and Raman spectroscopy revealed that the zirconia coating was composed of monoclinic zirconia which was stable at low temperature, and its surface consists of nano-size grains 30-50 nm in size. The bond strength between the coating and the Ti-6Al-4V substrate was 48.4 + or - 6.1 MPa, which is higher than that of plasma-sprayed HA coatings. Hydrothermal experiments indicated that the coating was stable in a water environment and the phase composition and Vickers hardness were independent of the hydrothermal treatment time. Bone-like apatite is observed to precipitate on the surface of the coating after soaking in simulated body fluid for 6 days, indicating excellent bioactivity in vitro. The nanostructured surface composed of monoclinic zirconia is believed to be crucial to its bioactivity. Morphological observation and the cell proliferation test demonstrated that osteoblast-like MG63 cells could attach to, adhere to and proliferate well on the surface of the monoclinic zirconia coating, suggesting possible applications in hard tissue replacements.

  12. Neutron diffraction observations of ferroelastic domain switching and tetragonal-to-monoclinic transformation in Ce-TZP

    Energy Technology Data Exchange (ETDEWEB)

    Kisi, E.H. [Univ. of Newcastle, Callaghan, New South Wales (Australia). Dept. of Mechanical Engineering; Kennedy, S.J.; Howard, C.J. [Australian Nuclear Science and Technology Organisation, Menai, New South Wales (Australia). Neutron Scattering Group

    1997-03-01

    In-situ neutron diffraction has been used to study the plastic deformation of a tetragonal zirconia polycrystal stabilized with 12 mol% ceria under compressive loads up to 1.6 GPa. The development of significant plastic strain in the ceramic has been found to be due to a combination of ferroelastic switching and the tetragonal-to-monoclinic phase transformation, both beginning at {approximately}1.2 GPa. Evidence of a strong coupling between the two phenomena is present. Both transitions are partially reversed on removal of the load. The linear elastic response of the a and c crystal axes of the parent tetragonal phase suggests that the ferroelastic switching occurs directly by a shear mechanism rather than via a cubic intermediate state. Anisotropic distortion of the tetragonal unit cell, as the critical stress is approached, gives some insight into the shear transformation mechanisms.

  13. Bis[2-(hydroxyiminomethylphenolato]nickel(II: a second monoclinic polymorph

    Directory of Open Access Journals (Sweden)

    Julia A. Rusanova

    2011-02-01

    Full Text Available The title compound, [Ni(C7H6NO22], (I, is a second monoclinic polymorph of the compound, (II, reported by Srivastava et al. [Acta Cryst. (1967, 22, 922] and Mereiter [Private communication (2002 CCDC refcode NISALO01]. The bond lengths and angles are similar in both structures. The molecule in both structures lies on a crystallographic inversion center and both have an internal hydrogen bond. The title compound crystallizes in the space group P21/c (Z = 2, whereas compound (II is in the space group P21/n (Z = 2 with a similar cell volume but different cell parameters. In both polymorphs, molecules are arranged in the layers but in contrast to the previously published compound (II where the dihedral angle between the layers is 86.3°, in the title polymorph the same dihedral angle is 29.4°. The structure of (I is stabilized by strong intramolecular O—H...O hydrogen bonding between the O—H group and the phenolate O atom.

  14. Vibrational Spectroscopy and Phonon-Related Properties of the L-Aspartic Acid Anhydrous Monoclinic Crystal.

    Science.gov (United States)

    Silva, A M; Costa, S N; Sales, F A M; Freire, V N; Bezerra, E M; Santos, R P; Fulco, U L; Albuquerque, E L; Caetano, E W S

    2015-12-10

    The infrared absorption and Raman scattering spectra of the monoclinic P21 l-aspartic acid anhydrous crystal were recorded and interpreted with the help of density functional theory (DFT) calculations. The effect of dispersive forces was taken into account, and the optimized unit cells allowed us to obtain the vibrational normal modes. The computed data exhibits good agreement with the measurements for low wavenumbers, allowing for a very good assignment of the infrared and Raman spectral features. The vibrational spectra of the two lowest energy conformers of the l-aspartic molecule were also evaluated using the hybrid B3LYP functional for the sake of comparison, showing that the molecular calculations give a limited description of the measured IR and Raman spectra of the l-aspartic acid crystal for wavenumbers below 1000 cm(-1). The results obtained reinforce the need to use solid-state calculations to describe the vibrational properties of molecular crystals instead of calculations for a single isolated molecule picture even for wavenumbers beyond the range usually associated with lattice modes (200 cm(-1) < ω < 1000 cm(-1)).

  15. Structural, microstructural and vibrational analyses of the monoclinic tungstate BiLuWO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Ait Ahsaine, H. [Laboratoire Matériaux et Environnement LME, Faculté des Sciences, Université Ibn Zohr, BP 8106 Cité Dakhla, Agadir (Morocco); Taoufyq, A. [Laboratoire Matériaux et Environnement LME, Faculté des Sciences, Université Ibn Zohr, BP 8106 Cité Dakhla, Agadir (Morocco); Institut Matériaux Microélectronique et Nanosciences de Provence, IM2NP, UMR CNRS 7334, Université de Toulon, BP 20132, 83957 La Garde Cedex (France); Patout, L. [Institut Matériaux Microélectronique et Nanosciences de Provence, IM2NP, UMR CNRS 7334, Université de Toulon, BP 20132, 83957 La Garde Cedex (France); Ezahri, M.; Benlhachemi, A.; Bakiz, B. [Laboratoire Matériaux et Environnement LME, Faculté des Sciences, Université Ibn Zohr, BP 8106 Cité Dakhla, Agadir (Morocco); Villain, S.; Guinneton, F. [Institut Matériaux Microélectronique et Nanosciences de Provence, IM2NP, UMR CNRS 7334, Université de Toulon, BP 20132, 83957 La Garde Cedex (France); Gavarri, J.-R., E-mail: gavarri.jr@univ-tln.fr [Institut Matériaux Microélectronique et Nanosciences de Provence, IM2NP, UMR CNRS 7334, Université de Toulon, BP 20132, 83957 La Garde Cedex (France)

    2014-10-15

    The bismuth lutetium tungstate phase BiLuWO{sub 6} has been prepared using a solid state route with stoichiometric mixtures of oxide precursors. The obtained polycrystalline phase has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. In the first step, the crystal structure has been refined using Rietveld method: the crystal cell was resolved using monoclinic system (parameters a, b, c, β) with space group A2/m. SEM images showed the presence of large crystallites with a constant local nominal composition (BiLuW). TEM analyses showed that the actual local structure could be better represented by a superlattice (a, 2b, c, β) associated with space groups P2 or P2/m. The Raman spectroscopy showed the presence of vibrational bands similar to those observed in the compounds BiREWO{sub 6} with RE=Y, Gd, Nd. However, these vibrational bands were characterized by large full width at half maximum, probably resulting from the long range Bi/Lu disorder and local WO{sub 6} octahedron distortions in the structure. - Graphical abstract: The average structure of BiLuWO{sub 6} determined from X-ray diffraction data can be represented by A2/m space group. Experimental Electron Diffraction patterns along the [0vw] zone axes of the monoclinic structure and associated simulated patterns show the existence of a monoclinic superstructure with space group P2 or P2/m. - Highlights: • A new monoclinic BiLuWO{sub 6} phase has been elaborated from solid-state reaction. • The space group of the monoclinic disordered average structure should be A2/m. • Transmission electron microscopy leads to a superlattice with P2/m space group. • Raman spectroscopy suggests existence of local disorder.

  16. Reversible (unitized) PEM fuel cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Mitlitsky, F; Myers, B; Smith, W F; Weisberg, Molter, T M

    1999-06-01

    Regenerative fuel cells (RFCs) are enabling for many weight-critical portable applications, since the packaged specific energy (>400 Wh/kg) of properly designed lightweight RFC systems is several-fold higher than that of the lightest weight rechargeable batteries. RFC systems can be rapidly refueled (like primary fuel cells), or can be electrically recharged (like secondary batteries) if a refueling infrastructure is not conveniently available. Higher energy capacity systems with higher performance, reduced weight, and freedom from fueling infrastructure are the features that RFCs promise for portable applications. Reversible proton exchange membrane (PEM) fuel cells, also known as unitized regenerative fuel cells (URFCs), or reversible regenerative fuel cells, are RFC systems which use reversible PEM cells, where each cell is capable of operating both as a fuel cell and as an electrolyzer. URFCs further economize portable device weight, volume, and complexity by combining the functions of fuel cells and electrolyzers in the same hardware, generally without any system performance or efficiency reduction. URFCs are being made in many forms, some of which are already small enough to be portable. Lawrence Livermore National Laboratory (LLNL) has worked with industrial partners to design, develop, and demonstrate high performance and high cycle life URFC systems. LLNL is also working with industrial partners to develop breakthroughs in lightweight pressure vessels that are necessary for URFC systems to achieve the specific energy advantages over rechargeable batteries. Proton Energy Systems, Inc. (Proton) is concurrently developing and commercializing URFC systems (UNIGEN' product line), in addition to PEM electrolyzer systems (HOGEN' product line), and primary PEM fuel cell systems. LLNL is constructing demonstration URFC units in order to persuade potential sponsors, often in their own conference rooms, that advanced applications based on URFC s are

  17. Evidence for photo-induced monoclinic metallic VO{sub 2} under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Wen-Pin, E-mail: wphsieh@stanford.edu; Mao, Wendy L. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305 (United States); Trigo, Mariano [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Reis, David A. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Photon Science and Applied Physics, Stanford University, Stanford, California 94305 (United States); Andrea Artioli, Gianluca; Malavasi, Lorenzo [Dipartimento di Chimica, Sezione di Chimica Fisica, INSTM (UdR Pavia), Università di Pavia, Viale Taramelli 16, 27100 Pavia (Italy)

    2014-01-13

    We combine ultrafast pump-probe spectroscopy with a diamond-anvil cell to decouple the insulator-metal electronic transition from the lattice symmetry changing structural transition in the archetypal strongly correlated material vanadium dioxide. Coherent phonon spectroscopy enables tracking of the photo-excited phonon vibrational frequencies of the low temperature, monoclinic (M{sub 1})-insulating phase that transforms into the metallic, tetragonal rutile structured phase at high temperature or via non-thermal photo-excitations. We find that in contrast with ambient pressure experiments where strong photo-excitation promptly induces the electronic transition along with changes in the lattice symmetry, at high pressure, the coherent phonons of the monoclinic (M{sub 1}) phase are still clearly observed upon the photo-driven phase transition to a metallic state. These results demonstrate the possibility of synthesizing and studying transient phases under extreme conditions.

  18. Evaluation of physicochemical properties, and antimicrobial efficacy of monoclinic sulfur-nanocolloid

    Energy Technology Data Exchange (ETDEWEB)

    Roy Choudhury, Samrat, E-mail: samratroychoudhury@gmail.com [Indian Statistical Institute, Biological Sciences Division (India); Mandal, Amrita; Chakravorty, Dipankar [Indian Association for the Cultivation of Science (India); Gopal, Madhuban [Indian Agricultural Research Institute, Divisions of Agricultural Chemicals (India); Goswami, Arunava [Indian Statistical Institute, Biological Sciences Division (India)

    2013-04-15

    Stable nanocolloids of monoclinic sulfur ({beta}-SNPs) were prepared through 'water-in-oil microemulsion technique' at room temperature after suitable modifications of the surface. The morphology (rod shaped; {approx}50 nm in diameter) and allotropic nature (monoclinic) of the SNPs were investigated with Transmission Electron Microscopy and X-ray Diffraction technique. The surface modification, colloidal stability, and surface topology of {beta}-SNPs were evaluated with Fourier Transform Infrared Spectroscopy, zeta potential analysis, and Atomic Force Microscopy. Thermal decomposition pattern of these nanosized particles was determined by Thermo Gravimetric Analysis (TGA). {beta}-SNPs-colloids expressed excellent antimicrobial activities against a series of fungal and bacterial isolates with prominent deformities at their surface. In contrast, insignificant cytotoxicity was achieved against the human derived hepatoma (HepG2) cell line upon treatment with {beta}-SNPs. A simultaneous study was performed to determine the stock concentration of {beta}-SNP-colloids using a novel high phase liquid chromatographic method. Cumulative results of this study hence, elucidate the stabilization of nanosized monoclinic sulfur at room temperature and their potential antimicrobial efficacy over micron-sized sulfur.

  19. Monoclinic structure of hydroxylpyromorphite Pb10(PO4)6(OH)2 - hydroxylmimetite Pb10(AsO4)6(OH)2 solid solution series

    Science.gov (United States)

    Giera, Alicja; Manecki, Maciej; Borkiewicz, Olaf; Zelek, Sylwia; Rakovan, John; Bajda, Tomasz; Marchlewski, Tomasz

    2016-04-01

    Seven samples of hydroxyl analogues of pyromorphite-mimetite solid solutions series were synthesized from aqueous solutions at 80° C in a computer-controlled chemistate: 200 mL aqueous solutions of 0.05M Pb(NO3)2 and 0.03M KH2AsO4 and/or KH2PO4 were dosed with a 0.25 mL/min rate to a glass beaker, which initially contained 100 mL of distilled water. Constant pH of 8 was maintained using 2M KOH. The syntheses yielded homogeneous fine-grained white precipitates composition of which was close to theoretical Pb10[(PO4)6-x(AsO4)x](OH)2, where x = 0, 1, 2, 3, 4, 5, 6. High-resolution powder X-ray diffraction data were obtained in transmission geometry at the beamline 11-BM at the Advanced Photon Source (Argonne National Laboratory in Illinois, USA). The structure Rietveld refinements based on starting parameters of either hexagonal hydroxylpyromorphite or monoclinic mimetite-M were performed using GSAS+EXPGUI software. Apatite usually crystallizes in the hexagonal crystal system with the space group P63/m. For the first time, however, the lowering of the hexagonal to monoclinic crystal symmetry was observed in the hydroxyl variety of pyromorphite-mimetite solid solution series. This is indicated by better fitting of the modeled monoclinic structure to the experimental data. The same is not the case for analogous calcium hydroxylapatite series Ca5(PO4)3OH - Ca5(AsO4)3OH (Lee et al. 2009). Systematical linear increase of unit cell parameters is observed with As substitution from a=9.88, b=19.75, and c=7.43 for Pb10(PO4)6(OH)2 to a=10.23, b=20.32, and c=7.51 for Pb10(AsO4)6(OH)2. A strong pseudohexagonal character (γ ≈ 120° and b ≈ 2a) of the analyzed monoclinic phases was established. This work is partially funded by AGH research grant no 11.11.140.319 and partially by Polish NCN grant No 2011/01/M/ST10/06999. Lee Y.J., Stephens P.W., Tang Y., Li W., Philips B.L., Parise J.B., Reeder R.J., 2009. Arsenate substitution in hydroxylapatite: Structural characterization

  20. Frequency Selective Surfaces with Nanoparticles Unit Cell

    Directory of Open Access Journals (Sweden)

    Nga Hung Poon

    2015-09-01

    Full Text Available The frequency selective surface (FSS is a periodic structure with filtering performance for optical and microwave signals. The general periodic arrays made with patterned metallic elements can act as an aperture or patch on a substrate. In this work, two kinds of materials were used to produce unit cells with various patterns. Gold nanoparticles of 25 nm diameter were used to form periodic monolayer arrays by a confined photocatalytic oxidation-based surface modification method. As the other material, silver gel was used to create multiple layers of silver. Due to the ultra-thin nature of the self-assembled gold nanoparticle monolayer, it is very easy to penetrate the FSS with terahertz radiation. However, the isolated silver islands made from silver gel form thicker multiple layers and contribute to much higher reflectance. This work demonstrated that multiple silver layers are more suitable than gold nanoparticles for use in the fabrication of FSS structures.

  1. Non-laminate Microstructures in Monoclinic-I Martensite

    CERN Document Server

    Chenchiah, Isaac Vikram

    2012-01-01

    We study the symmetrised rank-one convex hull of monoclinic-I martensite (a twelve-variant material) in the context of geometrically-linear elasticity. We show that this hull is strictly larger than the symmetrised lamination convex hull by constructing sets of T3s, which are (non-trivial) symmetrised rank-one convex hulls of 3-tuples of pairwise incompatible strains. Moreover we construct a five-dimensional continuum of T3s and show that its intersection with the boundary of the symmetrised rank-one convex hull is four-dimensional. Along the way we show that there is another kind of monoclinic-I martensite with qualitatively different semi-convex hulls which, so far as we know, has not been experimentally observed. Our strategy is to combine understanding of the algebraic structure of symmetrised rank-one convex cones with knowledge of the faceting structure of the convex polytope formed by the strains.

  2. Non-Laminate Microstructures in Monoclinic-I Martensite

    Science.gov (United States)

    Chenchiah, Isaac Vikram; Schlömerkemper, Anja

    2013-01-01

    We study the symmetrised rank-one convex hull of monoclinic-I martensite (a twelve-variant material) in the context of geometrically-linear elasticity. We construct sets of T 3s, which are (non-trivial) symmetrised rank-one convex hulls of three-tuples of pairwise incompatible strains. In addition, we construct a fivedimensional continuum of T 3s and show that its intersection with the boundary of the symmetrised rank-one convex hull is four-dimensional.We also show that there is another kind of monoclinic-I martensite with qualitatively different semi-convex hulls which, as far as we know, has not been experimentally observed. Our strategy is to combine understanding of the algebraic structure of symmetrised rank-one convex cones with knowledge of the faceting structure of the convex polytope formed by the strains.

  3. Solid State Synthesis and Properties of Monoclinic Celsian

    Science.gov (United States)

    Bansal, Narottam P.

    1996-01-01

    Monoclinic celsian of Ba(0.75)Sr(0.25)Al2Si2O8 (BSAS-1) and B(0.85)Sr(O.15)Al2Si2O8 (BSAS-2) compositions have been synthesized from metal carbonates and oxides by solid state reaction. A mixture of BaCO3, SrCO3, Al2O3, and SiO2 powders was precalcined at approx. 900-940 C to decompose the carbonates followed by hot pressing at approx. 1300 C. The hot pressed BSAS-1 material was almost fully dense and contained the monoclinic celsian phase, with complete absence of the undesirable hexacelsian as indicated by x-ray diffraction. In contrast, a small fraction of hexacelsian was still present in hot pressed BSAS-2. However, on further heat treatment at 1200 C for 24 h, the hexacelsian phase was completely eliminated. The average linear thermal expansion coefficients of BSAS-1 and BSAS-2 compositions, having the monoclinic celsian phase, were measured to be 5.28 x 10(exp -6)/deg C and 5.15 x 10(exp -6)/deg C, respectively from room temperature to 1200 C. The hot pressed BSAS-1 celsian showed room temperature flexural strength of 131 MPa, elastic modulus of 96 GPa and was stable in air up to temperatures as high as approx. 1500 C.

  4. Seismic transpressive basement faults and monocline development in a foreland basin (Eastern Guadalquivir, SE Spain)

    Science.gov (United States)

    Pedrera, A.; Ruiz-Constán, A.; Marín-Lechado, C.; Galindo-Zaldívar, J.; González, A.; Peláez, J. A.

    2013-12-01

    We examine the late Tortonian to present-day deformation of an active seismic sector of the eastern Iberian foreland basement of the Betic Cordillera, in southern Spain. Transpressive faults affecting Paleozoic basement offset up to Triassic rocks. Late Triassic clays and evaporites constitute a décollement level decoupling the basement rocks and a ~100 m thick cover of Jurassic carbonates. Monoclines trending NE-SW to ENE-WSW deform the Jurassic cover driven by the propagation of high-angle transpressive right-lateral basement faults. They favor the migration of clays and evaporites toward the propagated fault tip, i.e., the core of the anticline, resulting in fluid overpressure, fluid flow, and precipitation of fibrous gypsum parallel to a vertical σ3. The overall geometry of the studied monoclines, as well as the intense deformation within the clays and evaporites, reproduces three-layer discrete element models entailing a weak middle unit sandwiched between strong layers. Late Tortonian syn-folding sediments recorded the initial stages of the fault-propagation folding. Equivalent unexposed transpressive structures and associated monoclines reactivated under the present-day NW-SE convergence are recognized and analyzed in the Sabiote-Torreperogil region, using seismic reflection, gravity, and borehole data. A seismic series of more than 2100 low-magnitude earthquakes was recorded within a very limited area of the basement of this sector from October 2012 to May 2013. Seismic activity within a major NE-SW trending transpressive basement fault plane stimulated rupture along a subsidiary E-W (~N95°E) strike-slip relay fault. The biggest event (mbLg 3.9, MW 3.7) occurred at the junction between them in a transpressive relay sector.

  5. Lithium-Ion Cell Charge-Control Unit Developed

    Science.gov (United States)

    Reid, Concha M.; Manzo, Michelle A.; Buton, Robert M.; Gemeiner, Russel

    2005-01-01

    A lithium-ion (Li-ion) cell charge-control unit was developed as part of a Li-ion cell verification program. This unit manages the complex charging scheme that is required when Li-ion cells are charged in series. It enables researchers to test cells together as a pack, while allowing each cell to charge individually. This allows the inherent cell-to-cell variations to be addressed on a series string of cells and reduces test costs substantially in comparison to individual cell testing.

  6. Novel negative mass density resonant metamaterial unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Cselyuszka, Norbert, E-mail: cselyu@yahoo.com; Sečujski, Milan, E-mail: secujski@uns.ac.rs; Crnojević-Bengin, Vesna, E-mail: bengin@uns.ac.rs

    2015-01-02

    In this paper a novel resonant unit cell of one-dimensional acoustic metamaterials is presented, which exhibits negative effective mass density. We theoretically analyze the unit cell and develop a closed analytical formula for its effective mass density. Then we proceed to demonstrate left-handed propagation of acoustic waves using the proposed unit cell. Finally, we present its dual-band version, capable of operating at two independent frequencies. - Highlights: • A novel acoustic metamaterial unit cell provides Lorentz-type resonant effective mass density. • Analytical formula for effective mass density is derived. • Acoustic bandstop medium and left-handed metamaterial based on the novel unit cell are presented. • Modified version of the unit cell, operating at two independent frequencies, is proposed.

  7. Crystal structure of a new monoclinic polymorph of N-(4-methylphenyl-3-nitropyridin-2-amine

    Directory of Open Access Journals (Sweden)

    Aina Mardia Akhmad Aznan

    2014-08-01

    Full Text Available The title compound, C12H11N3O2, is a second monoclinic polymorph (P21, with Z′ = 4 of the previously reported monoclinic (P21/c, with Z′ = 2 form [Akhmad Aznan et al. (2010. Acta Cryst. E66, o2400]. Four independent molecules comprise the asymmetric unit, which have the common features of a syn disposition of the pyridine N atom and the toluene ring, and an intramolecular amine–nitro N—H...O hydrogen bond. The differences between molecules relate to the dihedral angles between the rings which range from 2.92 (19 to 26.24 (19°. The geometry-optimized structure [B3LYP level of theory and 6–311 g+(d,p basis set] has the same features except that the entire molecule is planar. In the crystal, the three-dimensional architecture is consolidated by a combination of C—H...O, C—H...π, nitro-N—O...π and π–π interactions [inter-centroid distances = 3.649 (2–3.916 (2 Å].

  8. A Unit Cell Laboratory Experiment: Marbles, Magnets, and Stacking Arrangements

    Science.gov (United States)

    Collins, David C.

    2011-01-01

    An undergraduate first-semester general chemistry laboratory experiment introducing face-centered, body-centered, and simple cubic unit cells is presented. Emphasis is placed on the stacking arrangement of solid spheres used to produce a particular unit cell. Marbles and spherical magnets are employed to prepare each stacking arrangement. Packing…

  9. Synthesis and characterization of monoclinic TiO2 nanosheets

    Institute of Scientific and Technical Information of China (English)

    WU Yu; XU Boqing

    2005-01-01

    A novel two-step method for the synthesis of monoclinic titanium oxide (i.e. TiO2(B)) nanosheets is presented in this report. The method is featured by two steps: 1) synthesis of hydrogen titanate nanosheets, followed by 2) calcination of the titanate nanosheets at elevated temperatures. The hydrogen titanate nanosheets were prepared first by autoclaving anatase TiO2 powders, obtained by air calcining an ethanol-gel of Ti(OH)4 at 500℃, in aqueous NaOH (10 mol/L) at 150―200℃, and then by washing with hydrochloric acid under supersonic irradiation. While sizes of the nanosheets were found to increase with increasing the temperature of the hydrothermal treatment, the calcination at 400―500℃ of the hydrogen titanate nanosheets that were synthesized at higher autoclaving temperatures (180―200℃) produced monoclinic TiO2 nanosheets with a uniform morphology. By contrast, the same calcination of the titanate nanosheets synthesized at the autoclaving temperature 180℃ led to anatase TiO2 nanoparticles.

  10. 2,3-Dibromo-3-phenylpropanoic acid: a monoclinic polymorph

    Directory of Open Access Journals (Sweden)

    Trent R. Howard

    2016-11-01

    Full Text Available Bromination of trans-cinnamic acid resulted in the formation of 2,3-dibromo-3-phenylpropanoic acid, C9H8Br2O2. Crystallization from ethanol–water (1:1 gave crystals of different shapes. One is in the form of rods, that crystallized as the orthorhombic polymorph (Pnma, and whose structure has been described [Thong et al. (2008. Acta Cryst. E64, o1946]. The other are thin plate-like crystals which are the monoclinic polymorph (P21/n. The structure of this monoclinic polymorph is similar to that of the orthorhombic polymorph; here the aliphatic C atoms are disordered over three sets of sites (occupancy ratio 0.5:0.25:0.25. In the crystal, molecules are linked by pairs of O—H...O hydrogen bonds, forming inversion dimers with an R22(8 ring motif. The dimers are linked by weak C—H...Br hydrogen bonds, forming chains propagating along the a-axis direction.

  11. Dynamic Heterogeneity In The Monoclinic Phase Of CCl$_4$

    CERN Document Server

    Caballero, Nirvana B; Carignano, Marcelo; Serra, Pablo

    2016-01-01

    Carbon tetrachloride (CCl$_4$) is one of the simplest compounds having a translationally stable monoclinic phase while exhibiting a rich rotational dynamics below 226 K. Recent nuclear quadrupolar resonance (NQR) experiments revealed that the dynamics of CCl$_4$ is similar to that of the other members of the isostructural series CBr$_{n}$Cl$_{4-n}$, suggesting that the universal relaxation features of canonical glasses such as $\\alpha$- and $\\beta$-relaxation are also present in non-glass formers. Using molecular dynamics (MD) simulations we studied the rotational dynamics in the monoclinic phase of CCl$_4$. The molecules undergo $C3$ type jump-like rotations around each one of the four C-Cl bonds. The rotational dynamics is very well described with a master equation using as the only input the rotational rates measured from the simulated trajectories. It is found that the heterogeneous dynamics emerges from faster and slower modes associated with different rotational axes, which have fixed orientations relat...

  12. 1-Nitro-4-(4-nitrophenoxybenzene: a second monoclinic polymorph

    Directory of Open Access Journals (Sweden)

    Arif Nadeem

    2013-12-01

    Full Text Available In the title compound, C12H8N2O5, the aromatic rings are inclined to one another by 56.14 (7°. The nitro groups are inclined by to the benzene rings to which they are attached by 3.86 (17 and 9.65 (15°. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a three-dimensional structure. The title compound is a new monoclinic polymorph, crystallizing in space group P21/c. The first polymorph crystallized in space group C2/c and the molecule possesses twofold rotation symmetry. Two low-temperature structures of this polymorph (150 K and 100 K, respectively have been reported [Meciarova et al. (2004. Private Communication (refcode IXOGAD. CCDC, Cambridge, England, and Dey & Desiraju (2005. Chem. Commun. pp. 2486–2488].

  13. A monoclinic polymorph of 2-(4-nitrophenylacetic acid

    Directory of Open Access Journals (Sweden)

    Alan R. Kennedy

    2016-12-01

    Full Text Available A new monoclinic form of 4-nitrophenylacetic acid, C8H7NO4, (I, differs from the known orthorhombic form both in its molecular conformation and in its intermolecular contacts. The conformation is different as the plane of the carboxylic acid group in (I is more nearly perpendicular to the plane of the aromatic ring [dihedral angle = 86.9 (3°] than in the previous form (74.5°. Both polymorphs display hydrogen-bonded R22(8 carboxylic acid dimeric pairs, but in (I, neighbouring dimers interact through nitro–nitro N...O dipole–dipole contacts rather than the nitro–carbonyl contacts found in the orthorhombic form.

  14. What causes the Besnus transition in monoclinic pyrrhotite?

    Science.gov (United States)

    Gehring, A. U.; Koulialias, D.; Löffler, J. F.; Charilaou, M.

    2016-12-01

    Monoclinic 4C pyrrhotite (ideal formula Fe7S8) is a major magnetic remanence carrier in the Earth's crust and in extraterrestrial materials. Because of its low-temperature magnetic transition around 30 K also known as Besnus transition, this mineral phase is easily detectable in rock samples. An intrinsic origin of the Besnus transition due to a crystallographic change similar to that in the Verwey transition has generally been postulated (1). Although the physical properties of pyrrhotite have intensively been studied, the physics behind the pronounced change in magnetization at the low-temperature transition is still unresolved. To address this question we performed structural and magnetic analyses on a natural pyrrhotite single crystal (Fe6.6S8) from Auerbach, Germany (2,3). Chemical analysis, X-ray diffractometry and transmission electron microscopy show that this pyrrhotite consists of an intergrowth of 4C and an incommensurate 5C* superstructure that are polymorphs with different vacancy distributions. The occurrence of two superstructures is magnetically confirmed by symmetric inflection points in the hysteresis measurements above the transition at about 30 K. The disappearance of the inflection points and the associated change of the hysteresis parameters indicate that the two superstructures become embedded to form a unitary magnetic anisotropy system at the transition. This embedding of the 5C* into the 4C pyrrhotite at about 30 K is directly visible by the occurrence of additional 4-fold and 12-fold symmetry terms in magnetic anisotropy and anisotropic magnetic resistivity mesarurements, respectively. From this it follows that the Besnus transition in monoclinic pyrrhotite is an extrinsic magnetic phenomenon with respect to the 4C superstructure, i.e., a coupling effect, and therefore the physics behind it is in fact different from that of the well-known Verwey transition. (1) Rochette et al., The IRM Quarterly, 21, 1 (2011); (2) Charilaou et al., J

  15. Unexpected origin of magnetism in monoclinic Nb12O29 from first-principles calculations

    NARCIS (Netherlands)

    Fang, C. M.; Van Huis, M. A.; Xu, Q.; Cava, R. J.; Zandbergen, H. W.

    2015-01-01

    Nb12O29 is a 4d transition metal oxide that occurs in two forms with different symmetries, monoclinic (m) and orthorhombic (o). The monoclinic form has unusual magnetic properties; below a temperature of 12 K, it exhibits both metallic conductivity and antiferromagnetic ordering. Here, first-princip

  16. Electronic structure and magnetic properties of monoclinic β-Cu2V2O7 : A GGA+U study

    Science.gov (United States)

    Yashima, Masatomo; Suzuki, Ryosuke O.

    2009-03-01

    A first-principles study on monoclinic C2/c copper pyrovanadate β-Cu2V2O7 has been performed using the generalized gradient approximation (GGA) and GGA+U method. The optimized unit-cell parameters and atomic coordinates of β-Cu2V2O7 agree well with experimental data. The optimized crystal structure of β-Cu2V2O7 indicates the existence of one-dimensional -Cu-Cu-Cu-Cu- chains. The electronic structure and magnetic properties were evaluated by the GGA+U calculations, which indicate that the β-Cu2V2O7 is a semiconducting antiferromagnetic material with an indirect band gap and local magnetic moment per Cu atom of 0.73μB . The intrachain exchanges for short and long Cu-Cu couples are estimated to be 6.4 and 4.1 meV, respectively, while the calculated interchain exchange (2.1 meV) is smaller, which indicate the one-dimensional character. The top of the valence band is composed of V3d , O2p , and Cu3d electrons while the bottom of the conduction band is primarily composed of Cu3d electrons. Valence electron-density distribution map indicates the V-O and Cu-O covalent bonds. Calculated partial electronic density of states strongly suggests that the V-O and Cu-O covalent bonds are mainly attributed to the overlaps of V3d and O2p atomic orbitals and of Cu3d and O2p , respectively.

  17. Dispersion of Love Waves in a Composite Layer Resting on Monoclinic Half-Space

    Directory of Open Access Journals (Sweden)

    Sukumar Saha

    2011-01-01

    Full Text Available Dispersion of Love waves is studied in a fibre-reinforced layer resting on monoclinic half-space. The wave velocity equation has been obtained for a fiber-reinforced layer resting on monoclinic half space. Shear wave velocity ratio curve for Love waves has been shown graphically for fibre reinforced material layer resting on various monoclinic half-spaces. In a similar way, shear wave velocity ratio curve for Love waves has been plotted for an isotropic layer resting on various monoclinic half-spaces. From these curves, it has been observed that the curves are of similar type for a fibre reinforced layer resting on monoclinic half-spaces, and the shear wave velocity ratio ranges from 1.14 to 7.19, whereas for the case isotropic layer, this range varies from 1.0 to 2.19.

  18. Fabrication and characteristics of unit cell for SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwi-Yeol; Eom, Seung-Wook; Moon, Seong-In [Korea Electrotechnology Research Institute, Kyongnam (Korea, Republic of)] [and others

    1996-12-31

    Research and development on solid oxide fuel cells in Korea have been mainly focused on unit cell and small stack. Fuel cell system is called clean generation system which not cause NOx or SOx. It is generation efficiency come to 50-60% in contrast to 40% of combustion generation system. Among the fuel cell system, solid oxide fuel cell is constructed of ceramics, so stack construction is simple, power density is very high, and there are no corrosion problems. The object of this study is to develop various composing material for SOFC generation system, and to test unit cell performance manufactured. So we try to present a guidance for developing mass power generation system. We concentrated on development of manufacturing process for cathode, anode and electrolyte.

  19. Proton ordering in tetragonal and monoclinic H2O ice

    CERN Document Server

    Yen, Fei; Berlie, Adam; Liu, Xiaodi; Goncharov, Alexander F

    2015-01-01

    H2O ice remains one of the most enigmatic materials as its phase diagram reveals up to sixteen solid phases. While the crystal structure of these phases has been determined, the phase boundaries and mechanisms of formation of the proton-ordered phases remain unclear. From high precision measurements of the complex dielectric constant, we probe directly the degree of ordering of the protons in H2O tetragonal ice III and monoclinic ice V down to 80 K. A broadened first-order phase transition is found to occur near 202 K we attribute to a quenched disorder of the protons which causes a continuous disordering of the protons during cooling and metastable behavior. At 126 K the protons in ice III become fully ordered, and for the case of ice V becoming fully ordered at 113 K forming ice XIII. Two triple points are proposed to exist: one at 0.35 GPa and 126 K where ices III, IX and V coexist; and another at 0.35 GPa and 113 K where ices V, IX and XIII coexist. Our findings unravel the underlying mechanism driving th...

  20. A new monoclinic polymorph of 3-diethylamino-4-(4-methoxyphenyl-1,1-dioxo-4H-1λ6,2-thiazete-4-carbonitrile

    Directory of Open Access Journals (Sweden)

    Ahmed M. Orlando

    2010-08-01

    Full Text Available A new monoclinic form of the title compound, C14H17N3O3S, has been found upon slow crystallization from water. Another monoclinic form of the compound was obtained previously from a mixture of dichloromethane and diethyl ether [Clerici et al. (2002. Tetrahedron, 58, 5173–5178]. Both phases crystallize in space group P21/n with one molecule in the asymmetric unit. The formally single exocyclic C—N bond that connects the –NEt2 unit with the thiazete ring is considerably shorter than the adjacent, formally double, endocyclic C=N bond. This is likely to be due to the extended conjugated system between the electron-donor diethylammine fragment and the electron-withdrawing sulfonyl group. In the newly discovered polymorph, the methoxy group is rotated by almost 180° around the phenyl–OCH3 bond, resulting in a different molecular conformation.

  1. Identification of monoclinic θ-phase dispersoids in a 6061 aluminium alloy

    Science.gov (United States)

    Buchanan, Karl; Ribis, Joël; Garnier, Jérôme; Colas, Kimberly

    2016-04-01

    Intermetallic dispersoids play an important role in controlling the 6xxx alloy series' grain distribution and increasing the alloy's toughness. The dispersoid distribution in a 6061 aluminium alloy (Al-Mg-Si) was analysed by transmission electron microscopy, selected area diffraction and energy-dispersive X-ray spectroscopy. The dispersoids had three unique crystal structures: simple cubic ?, body-centred cubic ? and monoclinic (C2/m). While the SC and BCC dispersoids have been well characterized in the literature, a detailed analysis of monoclinic dispersoids has not been presented. Therefore, the current work discusses the chemical composition, crystal structure and morphology of the monoclinic dispersoids.

  2. Phase coexistence in ferroelectric solid solutions: Formation of monoclinic phase with enhanced piezoelectricity

    Directory of Open Access Journals (Sweden)

    Xiaoyan Lu

    2016-10-01

    Full Text Available Phase morphology and corresponding piezoelectricity in ferroelectric solid solutions were studied by using a phenomenological theory with the consideration of phase coexistence. Results have shown that phases with similar energy potentials can coexist, thus induce interfacial stresses which lead to the formation of adaptive monoclinic phases. A new tetragonal-like monoclinic to rhombohedral-like monoclinic phase transition was predicted in a shear stress state. Enhanced piezoelectricity can be achieved by manipulating the stress state close to a critical stress field. Phase coexistence is universal in ferroelectric solid solutions and may provide a way to optimize ultra-fine structures and proper stress states to achieve ultrahigh piezoelectricity.

  3. Learning about the Unit Cell and Crystal Lattice with Computerized Simulations and Games: A Pilot Study

    Science.gov (United States)

    Luealamai, Sutha; Panijpan, Bhinyo

    2012-01-01

    The authors have developed a computer-based learning module on the unit cell of various types of crystal. The module has two components: the virtual unit cell (VUC) part and the subsequent unit cell hunter part. The VUC is a virtual reality simulation for students to actively arrive at the unit cell from exploring, from a broad view, the crystal…

  4. Learning about the Unit Cell and Crystal Lattice with Computerized Simulations and Games: A Pilot Study

    Science.gov (United States)

    Luealamai, Sutha; Panijpan, Bhinyo

    2012-01-01

    The authors have developed a computer-based learning module on the unit cell of various types of crystal. The module has two components: the virtual unit cell (VUC) part and the subsequent unit cell hunter part. The VUC is a virtual reality simulation for students to actively arrive at the unit cell from exploring, from a broad view, the crystal…

  5. Biology 23. Unit One -- The Cell: Structure and Physiology.

    Science.gov (United States)

    Nederland Independent School District, TX.

    GRADES OR AGES: Not given. SUBJECT MATTER: Biology, the structure and physiology of the cell. ORGANIZATION AND PHYSICAL APPEARANCE: There are four sections: a) objectives for the unit, b) bibliography, c) activities, and d) evaluation. The guide is directed to the student rather than the teacher. The guide is mimeographed and stapled, with no…

  6. Polymer electrolyte fuel cell mini power unit for portable application

    Science.gov (United States)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E.; Zerbinati, O.

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H 2 supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm 2 and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance.

  7. Polymer electrolyte fuel cell mini power unit for portable application

    Energy Technology Data Exchange (ETDEWEB)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E. [CNR-ITAE, via Salita S. Lucia sopra Contesse n. 5, 98126 S. Lucia, Messina (Italy); Zerbinati, O. [Universita del Piemonte Orientale, Dip. di Scienze dell' Ambiente e della Vita, via Bellini 25/g, 15100 Alessandria (Italy)

    2007-06-20

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H{sub 2} supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm{sup 2} and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance. (author)

  8. Phase field modeling of tetragonal to monoclinic phase transformation in zirconia

    Science.gov (United States)

    Mamivand, Mahmood

    Zirconia based ceramics are strong, hard, inert, and smooth, with low thermal conductivity and good biocompatibility. Such properties made zirconia ceramics an ideal material for different applications form thermal barrier coatings (TBCs) to biomedicine applications like femoral implants and dental bridges. However, this unusual versatility of excellent properties would be mediated by the metastable tetragonal (or cubic) transformation to the stable monoclinic phase after a certain exposure at service temperatures. This transformation from tetragonal to monoclinic, known as LTD (low temperature degradation) in biomedical application, proceeds by propagation of martensite, which corresponds to transformation twinning. As such, tetragonal to monoclinic transformation is highly sensitive to mechanical and chemomechanical stresses. It is known in fact that this transformation is the source of the fracture toughening in stabilized zirconia as it occurs at the stress concentration regions ahead of the crack tip. This dissertation is an attempt to provide a kinetic-based model for tetragonal to monoclinic transformation in zirconia. We used the phase field technique to capture the temporal and spatial evolution of monoclinic phase. In addition to morphological patterns, we were able to calculate the developed internal stresses during tetragonal to monoclinic transformation. The model was started form the two dimensional single crystal then was expanded to the two dimensional polycrystalline and finally to the three dimensional single crystal. The model is able to predict the most physical properties associated with tetragonal to monoclinic transformation in zirconia including: morphological patterns, transformation toughening, shape memory effect, pseudoelasticity, surface uplift, and variants impingement. The model was benched marked with several experimental works. The good agreements between simulation results and experimental data, make the model a reliable tool for

  9. Bis[2-(hy-droxy-imino-meth-yl)phenolato]nickel(II): a second monoclinic polymorph.

    Science.gov (United States)

    Rusanova, Julia A; Buvaylo, Elena A; Rusanov, Eduard B

    2011-01-15

    The title compound, [Ni(C(7)H(6)NO(2))(2)], (I), is a second monoclinic polymorph of the compound, (II), reported by Srivastava et al. [Acta Cryst. (1967), 22, 922] and Mereiter [Private communication (2002) CCDC refcode NISALO01]. The bond lengths and angles are similar in both structures. The mol-ecule in both structures lies on a crystallographic inversion center and both have an inter-nal hydrogen bond. The title compound crystallizes in the space group P2(1)/c (Z = 2), whereas compound (II) is in the space group P2(1)/n (Z = 2) with a similar cell volume but different cell parameters. In both polymorphs, mol-ecules are arranged in the layers but in contrast to the previously published compound (II) where the dihedral angle between the layers is 86.3°, in the title polymorph the same dihedral angle is 29.4°. The structure of (I) is stabilized by strong intra-molecular O-H⋯O hydrogen bonding between the O-H group and the phenolate O atom.

  10. Microbial fuel cells as pollutant treatment units: Research updates.

    Science.gov (United States)

    Zhang, Quanguo; Hu, Jianjun; Lee, Duu-Jong

    2016-10-01

    Microbial fuel cells (MFC) are a device that can convert chemical energy in influent substances to electricity via biological pathways. Based on the consent that MFC technology should be applied as a waste/wastewater treatment unit rather than a renewable energy source, this mini-review discussed recent R&D efforts on MFC technologies for pollutant treatments and highlighted the challenges and research and development needs. Owing to the low power density levels achievable by larger-scale MFC, the MFC should be used as a device other than energy source such as being a pollutant treatment unit.

  11. Zero loss magnetic metamaterials using powered active unit cells.

    Science.gov (United States)

    Yuan, Yu; Popa, Bogdan-Ioan; Cummer, Steven A

    2009-08-31

    We report the design and experimental measurement of a powered active magnetic metamaterial with tunable permeability. The unit cell is based on the combination of an embedded radiofrequency amplifier and a tunable phase shifter, which together control the response of the medium. The measurements show that a negative permeability metamaterial with zero loss or even gain can be achieved through an array of such metamaterial cells. This kind of active metamaterial can find use in applications that are performance limited due to material losses.

  12. A heated vapor cell unit for DAVLL in atomic rubidium

    OpenAIRE

    McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L

    2007-01-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D2 transitions in atomic rubidium is described. A 5 cm-long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field...

  13. Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems

    Science.gov (United States)

    Mittelsteadt, Cortney K.; Braff, William

    2009-01-01

    In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a polymer that has very high water transport properties. Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center.

  14. Solid Oxide Fuel Cells coupled with a biomass gasification unit

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available A possibility of fuelling a solid oxide fuel cell stack (SOFC with biomass fuels can be realized by coupling a SOFC system with a self-standing gasification unit. Such a solution enables multi-fuel operation, elasticity of the system as well as the increase of the efficiency of small-scale biomass-to-electricity conversion units. A system of this type, consisting of biomass gasification unit, gas purification unit, SOFC stack, anode off-gas afterburner and peripherals was constructed and operated successfully. During the process, biomass fuel (wood chips was gasified with air as gasification agent. The gasifier was capable of converting up to 30 kW of fuel to syngas with efficiencies up to 75%. Syngas leaving the gasification unit is delivered to a medium temperature adsorber for sulphur compounds removal. Steam is added to the purified fuel to maintain steam to carbon ratio higher than 2. The syngas then is passed to a SOFC stack through a fuel preheater. In such a configuration it was possible to operate a commercial 1.3 kW stack within its working regime. Conducted tests confirmed successful operation of a SOFC stack fuelled by biomass-sourced syngas.

  15. Monoclinic high-pressure polymorph of AlOOH predicted from first principles

    Science.gov (United States)

    Zhong, Xin; Hermann, Andreas; Wang, Yanchao; Ma, Yanming

    2016-12-01

    Aluminum oxide hydroxide, AlOOH, is a prototypical hydrous mineral in the geonomy. The study of the high-pressure phase evolution of AlOOH is of fundamental importance in helping to understand the role of hydrous minerals in the water storage and transport in Earth, as in other planets. Here, we have systematically investigated the high-pressure phase diagram of AlOOH up to 550 GPa using the efficient crystal structure analysis by particle swarm optimization (CALYPSO) algorithm in conjunction with first principles calculations. We predict a peculiar monoclinic phase (space group P 21/c , 16 atoms/cell, Z =4 ) as the most stable phase for AlOOH above 340 GPa. The occurrence of this new phase results in the breakup of symmetric linear O-H-O hydrogen bonds into asymmetric, bent O-H-O linkages and in sevenfold coordinated metal cations. The new P 21/c phase turns out to be a universal high-pressure phase in group 13 oxide hydroxides, and stable for both compressed GaOOH and InOOH. The formation of the new phase in all compounds is favored by volume reduction due to denser packing.

  16. Thermodynamics of Condensed Phases: Formula Unit Volume, "V[subscript m]", and the Determination of the Number of Formula Units, "Z", in a Crystallographic Unit Cell

    Science.gov (United States)

    Glasser, Leslie

    2011-01-01

    Formula unit (or molecular) volume, "V[subscript m]", is related to many thermodynamic and physical properties of materials, so that knowledge of "V[subscript m]" is useful in prediction of such properties for known and even hypothetical materials. The symbol "Z" represents the number of formula units in a crystallographic unit cell; "Z" thus…

  17. Ab initio calculation of electron-phonon coupling in monoclinic β-Ga2O3 crystal

    Science.gov (United States)

    Ghosh, Krishnendu; Singisetti, Uttam

    2016-08-01

    The interaction between electrons and vibrational modes in monoclinic β-Ga2O3 is theoretically investigated using ab-initio calculations. The large primitive cell of β-Ga2O3 gives rise to 30 phonon modes all of which are taken into account in transport calculation. The electron-phonon interaction is calculated under density functional perturbation theory and then interpolated using Wannier-Fourier interpolation. The long-range interaction elements between electrons and polar optical phonon (POP) modes are calculated separately using the Born effective charge tensor. The direction dependence of the long-range POP coupling in a monoclinic crystal is explored and is included in the transport calculations. Scattering rate calculations are done using the Fermi golden rule followed by solving the Boltzmann transport equation using the Rode's method to estimate low field mobility. A room temperature mobility of 115 cm2/V s is observed. Comparison with recent experimentally reported mobility is done for a wide range of temperatures (30 K-650 K). It is also found that the POP interaction dominates the electron mobility under low electric field conditions. The relative contribution of the different POP modes is analyzed and the mode 21 meV POP is found to have the highest impact on low field electron mobility at room temperature.

  18. Post-patterning of an electronic homojunction in atomically thin monoclinic MoTe2

    Science.gov (United States)

    Kim, Sera; Kim, Jung Ho; Kim, Dohyun; Hwang, Geunwoo; Baik, Jaeyoon; Yang, Heejun; Cho, Suyeon

    2017-06-01

    Monoclinic group 6 transition metal dichalcogenides (TMDs) have been extensively studied for their intriguing 2D physics (e.g. spin Hall insulator) as well as for ohmic homojunction contacts in 2D device applications. A critical prerequisite for those applications is thickness control of the monoclinic 2D materials, which allows subtle engineering of the topological states or electronic bandgaps. Local thickness control enables the realization of clean homojunctions between different electronic states, and novel device operation in a single material. However, conventional fabrication processes, including chemical methods, typically produce non-homogeneous and relatively thick monoclinic TMDs, due to their distorted octahedral structures. Here, we report on a post-patterning technique using laser-irradiation to fabricate homojunctions between two different thickness areas in monoclinic MoTe2. A thickness-dependent electronic change from a metallic to semiconducting state, resulting in an electronic homojunction, was realized by the optical patterning of pristine MoTe2 flakes, and a pre-patterned device channel of monoclinic MoTe2 with a thickness-resolution of 5 nm. Our work provides insight on an optical post-process method for controlling thickness, as a promising approach for fabricating impurity-free 2D TMDs homojunction devices.

  19. Petrology of Karoo volcanic rocks in the southern Lebombo monocline, Mozambique

    Science.gov (United States)

    Melluso, Leone; Cucciniello, Ciro; Petrone, Chiara M.; Lustrino, Michele; Morra, Vincenzo; Tiepolo, Massimo; Vasconcelos, Lopo

    2008-11-01

    The Karoo volcanic sequence in the southern Lebombo monocline in Mozambique contains different silicic units in the form of pyroclastic rocks, and two different basalt types. The silicic units in the lower part of the Lebombo sequence are formed by a lower unit of dacites and rhyolites (67-80 wt.% SiO 2) with high Ba (990-2500 ppm), Zr (800-1100 ppm) and Y (130-240 ppm), which are part of the Jozini-Mbuluzi Formation, followed by a second unit, interlayered with the Movene basalts, of high-SiO 2 rhyolites (76-78 wt.%; the Sica Beds Formation), with low Sr (19-54 ppm), Zr (340-480 ppm) and Ba (330-850 ppm) plus rare quartz-trachytes (64-66 wt.% SiO 2), with high Nb and Rb contents (240-250 and 370-381 ppm, respectively), and relatively low Zr (450-460 ppm). The mafic rocks found at the top of the sequence are basalts and ferrobasalts belonging to the Movene Formation. The basalts have roughly flat mantle-normalized incompatible element patterns, with abundances of the most incompatible elements not higher than 25 times primitive mantle. The ferrobasalt has TiO 2 ˜ 4.7 wt.%, Fe 2O 3t = 16 wt.%, and high Y (100 ppm), Zr (420 ppm) and Ba (1000 ppm). The Movene basalts have initial (at 180 Ma) 87Sr/ 86Sr = 0.7052-0.7054 and 143Nd/ 144Nd = 0.51232, and the Movene ferrobasalt has even lower 87Sr/ 86Sr (0.70377) and higher 143Nd/ 144Nd (0.51259). The silicic rocks show a modest range of initial Sr-( 87Sr/ 86Sr = 0.70470-0.70648) and Nd-( 143Nd/ 144Nd = 0.51223-0.51243) isotope ratios. The less evolved dacites could have been formed after crystal fractionation of oxide-rich gabbroic cumulates from mafic parental magmas, whereas the most silica-rich rhyolites could have been formed after fractional crystallization of feldspars, pyroxenes, oxides, zircon and apatite from a parental dacite magma. The composition of the Movene basalts imply different feeding systems from those of the underlying Sabie River basalts.

  20. Zeroing in on red blood cell unit expiry.

    Science.gov (United States)

    Ayyalil, Fathima; Irwin, Greg; Ross, Bryony; Manolis, Michael; Enjeti, Anoop K

    2017-09-20

    Expiry of red blood cell (RBC) units is a significant contributor to wastage of precious voluntary donations. Effective strategies aimed at optimal resource utilization are required to minimize wastage. This retrospective study analyzed the strategic measures implemented to reduce expiry of RBC units in an Australian tertiary regional hospital. The measures, which included inventory rearrangement, effective stock rotation, and the number of emergency courier services required during a 24-month period, were evaluated. There was no wastage of RBC units due to expiry over the 12 months after policy changes. Before these changes, approximately half of RBC wastage (261/511) was due to expiry. The total number of transfusions remained constant in this period and there was no increase in the use of emergency couriers. Policy changes implemented were decreasing the RBC inventory level by one-third and effective stock rotation and using a computerized system to link the transfusion services across the area. Effective stock rotation resulted in a reduction in older blood (>28 days) received in the main laboratory rotated from peripheral hospitals, down from 6%-41% to 0%-2.5%. Age-related expiry of blood products is preventable and can be significantly reduced by improving practices in the pathology service. This study provides proof of principle for "zero tolerance for RBC unit expiry" across a large networked blood banking service. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  1. A second monoclinic polymorph of 2-[2-(4-methoxyphenylhydrazinylidene]-1,3-diphenylpropane-1,3-dione

    Directory of Open Access Journals (Sweden)

    Carlos Bustos

    2011-07-01

    Full Text Available The title compound, C22H18N2O3 is the second monoclinic polymorph (P21/c of the compound, the first being reported in space group P21 [Bertolasi et al. (1993. J. Chem. Soc. Perkin Trans. 2, pp. 2223–2228]. In the molecular structure of the title compound, the interplanar angle between the benzoyl units is 80.04 (5°, while the corresponding angles between the phenylhydrazinylidene and benzoyl groups are 36.11 (5 and 55.77 (2°. A strong resonance-assisted intramolecular N—H...O hydrogen bond is found. In the crystal, the entire supramolecular structure is constructed by weak intermolecular C—H...O interactions and an inter-ring π–π interaction [centroid–centroid distance = 3.6088 (8 Å].

  2. Flow field measurements in the cell culture unit

    Science.gov (United States)

    Walker, Stephen; Wilder, Mike; Dimanlig, Arsenio; Jagger, Justin; Searby, Nancy

    2002-01-01

    The cell culture unit (CCU) is being designed to support cell growth for long-duration life science experiments on the International Space Station (ISS). The CCU is a perfused loop system that provides a fluid environment for controlled cell growth experiments within cell specimen chambers (CSCs), and is intended to accommodate diverse cell specimen types. Many of the functional requirements depend on the fluid flow field within the CSC (e.g., feeding and gas management). A design goal of the CCU is to match, within experimental limits, all environmental conditions, other than the effects of gravity on the cells, whether the hardware is in microgravity ( micro g), normal Earth gravity, or up to 2g on the ISS centrifuge. In order to achieve this goal, two steps are being taken. The first step is to characterize the environmental conditions of current 1g cell biology experiments being performed in laboratories using ground-based hardware. The second step is to ensure that the design of the CCU allows the fluid flow conditions found in 1g to be replicated from microgravity up to 2g. The techniques that are being used to take these steps include flow visualization, particle image velocimetry (PIV), and computational fluid dynamics (CFD). Flow visualization using the injection of dye has been used to gain a global perspective of the characteristics of the CSC flow field. To characterize laboratory cell culture conditions, PIV is being used to determine the flow field parameters of cell suspension cultures grown in Erlenmeyer flasks on orbital shakers. These measured parameters will be compared to PIV measurements in the CSCs to ensure that the flow field that cells encounter in CSCs is within the bounds determined for typical laboratory experiments. Using CFD, a detailed simulation is being developed to predict the flow field within the CSC for a wide variety of flow conditions, including microgravity environments. Results from all these measurements and analyses of the

  3. Mechanical behavior of regular open-cell porous biomaterials made of diamond lattice unit cells.

    Science.gov (United States)

    Ahmadi, S M; Campoli, G; Amin Yavari, S; Sajadi, B; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2014-06-01

    Cellular structures with highly controlled micro-architectures are promising materials for orthopedic applications that require bone-substituting biomaterials or implants. The availability of additive manufacturing techniques has enabled manufacturing of biomaterials made of one or multiple types of unit cells. The diamond lattice unit cell is one of the relatively new types of unit cells that are used in manufacturing of regular porous biomaterials. As opposed to many other types of unit cells, there is currently no analytical solution that could be used for prediction of the mechanical properties of cellular structures made of the diamond lattice unit cells. In this paper, we present new analytical solutions and closed-form relationships for predicting the elastic modulus, Poisson׳s ratio, critical buckling load, and yield (plateau) stress of cellular structures made of the diamond lattice unit cell. The mechanical properties predicted using the analytical solutions are compared with those obtained using finite element models. A number of solid and porous titanium (Ti6Al4V) specimens were manufactured using selective laser melting. A series of experiments were then performed to determine the mechanical properties of the matrix material and cellular structures. The experimentally measured mechanical properties were compared with those obtained using analytical solutions and finite element (FE) models. It has been shown that, for small apparent density values, the mechanical properties obtained using analytical and numerical solutions are in agreement with each other and with experimental observations. The properties estimated using an analytical solution based on the Euler-Bernoulli theory markedly deviated from experimental results for large apparent density values. The mechanical properties estimated using FE models and another analytical solution based on the Timoshenko beam theory better matched the experimental observations. Copyright © 2014 Elsevier Ltd

  4. Efficient channel waveguide lasers in monoclinic double tungstates: towards further integration with on-chip mirrors

    NARCIS (Netherlands)

    van Dalfsen, Koop; van Wolferen, Hendricus A.G.M.; Dijkstra, Mindert; Aravazhi, S.; Bernhardi, Edward; García Blanco, Sonia Maria; Pollnau, Markus

    2012-01-01

    By varying the thulium concentration in the range of 1.5 – 8.0 at.% in thulium- gadolinium-lutetium-yttrium-co-doped monoclinic double tungstate channel waveguides, a maximum laser slope efficiency of 70% with respect to the absorbed pump power was obtained. Further integration of these channel

  5. Porous silicon for micro-sized fuel cell reformer units

    Energy Technology Data Exchange (ETDEWEB)

    Presting, H.; Konle, J.; Starkov, V.; Vyatkin, A.; Koenig, U

    2004-04-25

    Randomly, self-organized and ordered anodically etched porous silicon with pore sizes down to hundred nanometers have been fabricated for a variety of automotive applications which range from carrier structures in fuel cell technology up to shower heads for fuel injection in combustion engines. The porous wafers are produced by deep anodic etching which is a very effective and cheap fabrication method compatible to standard Si CMOS fabrication technology. The density of nano- (and micro-) pores can be varied in a wide range by choice of substrate doping level and appropriate electrolyte solution. Surface enlargement up to a factor of 1000 can be achieved [J. Electrochem. Soc. 149 (1) (2002) G70]. After deposition of a catalyst on the inner surface of the pores these structures can be used as an effective catalytic reaction area for the injected hydrocarbons in a micro-steam reformer unit with a small reaction volume. In addition deep anodic etching (DAE) of a pinhole array with very high aspect ratios is demonstrated using a pre-patterned inverted pyramidal array which is produced by lithography and subsequent wet chemical potassium hydroxide (KOH) etch. The structures can also be used as carrier structures for the hydrogen separation membrane of the reforming gas in a reformer unit when a thin layer of palladium is evaporated prior to the anodic etching of the pores. The noble metal foil serves as anode contact during the etch as well as hydrogen separating membrane of the device.

  6. Reflection of and SV waves at the free surface of a monoclinic elastic half-space

    Indian Academy of Sciences (India)

    Sarva Jit Singh; Sandhya Khurana

    2002-12-01

    The propagation of plane waves in an anisotropic elastic medium possessing monoclinic symmetry is discussed. The expressions for the phase velocity of qP and qSV waves propagating in the plane of elastic symmetry are obtained in terms of the direction cosines of the propagation vector. It is shown that, in general, qP waves are not longitudinal and qSV waves are not transverse. Pure longitudinal and pure transverse waves can propagate only in certain specific directions. Closed-form expressions for the reflection coefficients of qP and qSV waves incident at the free surface of a homogeneous monoclinic elastic half-space are obtained. These expressions are used for studying numerically the variation of the reflection coefficients with the angle of incidence. The present analysis corrects some fundamental errors appearing in recent papers on the subject.

  7. Fabrication and photoelectrocatalytic properties of nanocrystalline monoclinic BiVO4 thin-film electrode.

    Science.gov (United States)

    Zhou, Bin; Qu, Jiuhui; Zhao, Xu; Liu, Huijuan

    2011-01-01

    Monoclinic bismuth vanadate (BiVO4) thin film was fabricated on indium-tin oxide glass from an amorphous heteronuclear complex via dip-coating. After annealation at 400, 500, and 600 degrees C, the thin films were characterized by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis spectrophotometry. The BiVO4 particles on the ITO glass surface had a monoclinic structure. The UV-Visible diffuse reflection spectra showed the BiVO4 thin film had photoabsorption properties, with a band gap around 2.5 eV. In addition, the thin film showed high visible photocatalytic activities towards 2,4-dichlorophenol and Bisphenol A degradation under visible light irradiation (lambda > 420 nm). Over 90% of the two organic pollutants were removed in 5 hr. A possible degradation mechanism of 2,4-dichlorophenol were also studied.

  8. Fabrication and photoelectrocatalytic properties of nanocrystalline monoclinic BiVO4 thin-film electrode

    Institute of Scientific and Technical Information of China (English)

    Bin Zhou; Jiuhui Qu; Xu Zhao; Huijuan Liu

    2011-01-01

    Monoclinic bismuth vanadate (BiVO4) thin film was fabricated on indium-tin oxide glass from an amorphous heteronuclear complex via dip-coating.After annealation at 400, 500, and 600℃, the thin films were characterized by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis spectrophotometry.The BiVO4 particles on the ITO glass surface had a monoclinic structure.The UV-Visible diffuse reflection spectra showed the BiVO4 thin film had photoabsorption properties, with a band gap around 2.5 eV.In addition, the thin film showed high visible photocatalytic activities towards 2,4-dichiorophenol and Bisphenol A degradation under visible light irradiation (λ.> 420 nm).Over 90% of the two organic pollutants were removed in 5 hr.A possible degradation mechanism of 2,4-dichlorophenol were also studied.

  9. Seismic Data Interpretation: A Case Study of Southern Sindh Monocline, Lower Indus Basin, Pakistan

    Directory of Open Access Journals (Sweden)

    Shabeer Ahmed Abbasi

    2015-04-01

    Full Text Available The Sindh monocline in Lower Indus Basin is an important oil and gas producing area of Pakistan where a large number of oil, gas and condensate fields have been discovered from structural traps. This research involves the interpretation of stratigraphic and structural styles of Sindh Monocline using 2D (Two-Dimensional seismic reflection and well log. Four reflectors of different formations have been marked and were named as Reflector-1 as of Khadro Formation, Reflector-2 as Upper Goru Member, Reflector-3 as Lower Goru Formation and Reflector-4 as Chiltan Limestone. The average depth of Khadro Formation was marked at 449.0m, Upper Goru Member at 968m, Lower Goru Formation at 1938m and Chiltan Limestone at 2943m. Faults were marked on seismic sections which collectively form horsts and grabens which is the evidence of extensional tectonic in the area. Seismic interpretation was carried out through window based Kingdom Software

  10. Crystalline and magnetic ordering in the monoclinic phase of the layered perovskite PAMC

    DEFF Research Database (Denmark)

    Harris, P.; Lebech, B.; Achiwa, N.

    1994-01-01

    of 1/3b*, and below 39 K PAMC is an antiferromagnet with a small ferromagnetic component. The temperature dependence of the monoclinic angle alpha depends on the mosaicity of the crystal which increases with the number of 'cooling cycles'. The satellite reflections do not have any contribution from...... the magnetic ordering, but their intensity has abrupt changes that coincide with changes in either the nuclear or the magnetic ordering parameter. Magnetoelastic effects seem to influence the ordering of the crystal....

  11. Changes in mobility of plastic crystal ethanol during its transformation into the monoclinic crystal state

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Alejandro, E-mail: alejandro.sanz@csic.es; Nogales, Aurora; Ezquerra, Tiberio A. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain); Puente-Orench, Inés [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Instituto de Ciencia de Materiales de Aragón, ICMA-CSIC, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Jiménez-Ruiz, Mónica [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)

    2014-02-07

    Transformation of deuterated ethanol from the plastic crystal phase into the monoclinic one is investigated by means of a singular setup combining simultaneously dielectric spectroscopy with neutron diffraction. We postulate that a dynamic transition from plastic crystal to supercooled liquid-like configuration through a deep reorganization of the hydrogen-bonding network must take place as a previous step of the crystallization process. Once these precursor regions are formed, subsequent crystalline nucleation and growth develop with time.

  12. Super Unit Cells in Aperture-Based Metamaterials

    Directory of Open Access Journals (Sweden)

    Dragan Tanasković

    2015-01-01

    Full Text Available An important class of electromagnetic metamaterials are aperture-based metasurfaces. Examples include extraordinary optical transmission arrays and double fishnets with negative refractive index. We analyze a generalization of such metamaterials where a simple aperture is now replaced by a compound object formed by superposition of two or more primitive objects (e.g., rectangles, circles, and ellipses. Thus obtained “super unit cell” shows far richer behavior than the subobjects that comprise it. We show that nonlocalities introduced by overlapping simple subobjects can be used to produce large deviations of spectral dispersion even for small additive modifications of the basic geometry. Technologically, some super cells may be fabricated by simple spatial shifting of the existing photolithographic masks. In our investigation we applied analytical calculations and ab initio finite element modeling to prove the possibility to tailor the dispersion including resonances for plasmonic nanocomposites by adjusting the local geometry and exploiting localized interactions at a subwavelength level. Any desired form could be defined using simple primitive objects, making the situation a geometrical analog of the case of series expansion of a function. Thus an additional degree of tunability of metamaterials is obtained. The obtained designer structures can be applied in different fields like waveguiding and sensing.

  13. Effect of Yttria Content on the Zirconia Unit Cell Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Krogstad, Jessica A.; Lepple, Maren; Gao, Yan; Lipkin, Don M.; Levi, Carlos G. (UCSB); (GE Global)

    2012-02-06

    The relationship between yttria concentration and the unit cell parameters in partially and fully stabilized zirconia has been reassessed, motivated by the need to improve the accuracy of phase analysis upon decomposition of t{prime}-based thermal barrier coatings. Compositions ranging from 6 to 18 mol% YO{sub 1.5} were synthesized and examined by means of high-resolution X-ray diffraction. Lattice parameters were determined using the Rietveld refinement method, a whole-pattern fitting procedure. The revised empirical relationships fall within the range of those published previously. However, efforts to achieve superior homogeneity of the materials, as well as accuracy of the composition and lattice parameters, provide increased confidence in the reliability of these correlations for use in future studies. Additional insight into the potential sources for scatter previously reported for the transition region ({approx}12-14 mol% YO{sub 1.5}), where tetragonal and cubic phases have been observed to coexist, is also provided. Implications on the current understanding of stabilization mechanisms in zirconia are discussed.

  14. Metastable monoclinic ZnMoO4: hydrothermal synthesis, optical properties and photocatalytic performance.

    Science.gov (United States)

    Lv, Li; Tong, Wenming; Zhang, Yanbing; Su, Yiguo; Wang, Xiaojing

    2011-11-01

    Metastable monoclinic ZnMoO4 was successfully synthesized via a hydrothermal route with variation of reaction temperatures and time at pH value of 5.7. Systematic sample characterizations were carried out, including X-ray powder diffraction, scanning electron microscopy, Fourier transformed infrared spectra, UV-visible diffuse reflectance spectra, and photoluminescence spectra. The results show that all as-prepared ZnMoO4 samples were demonstrated to crystallize in a pure-phase of monoclinic wolframite structure. All samples were formed in plate-like morphology. Six IR active vibrational bands were observed in the wave number range of 400-900 cm(-1). The band gap of as-prepared ZnMoO4 was estimated to be 2.86 eV by Tauc equation. Photoluminescence measurement indicates that as-prepared ZnMoO4 exhibits a broad blue-green emission under excitation wavelength of 280 nm at room temperature. Photocatalytic activity of as-prepared ZnMoO4 was examined by monitoring the degradation of methyl orange dye in an aqueous solution under UV radiation of 365 nm. The as-prepared ZnMoO4 obtained at 180 degrees C for 40 h showed the best photocatalytic activity with completing degradation of MO in irradiation time of 120 min. Consequently, monoclinic ZnMoO4 proved to be an efficient near visible light photocatalyst.

  15. Formation energies of intrinsic point defects in monoclinic VO2 studied by first-principles calculations

    Science.gov (United States)

    Cui, Yuanyuan; Liu, Bin; Chen, Lanli; Luo, Hongjie; Gao, Yanfeng

    2016-10-01

    VO2 is an attractive candidate for intelligent windows and thermal sensors. There are challenges for developing VO2-based devices, since the properties of monoclinic VO2 are very sensitive to its intrinsic point defects. In this work, the formation energies of the intrinsic point defects in monoclinic VO2 were studied through the first-principles calculations. Vacancies, interstitials, as well as antisites at various charge states were taken into consideration, and the finite-size supercell correction scheme was adopted as the charge correction scheme. Our calculation results show that the oxygen interstitial and oxygen vacancy are the most abundant intrinsic defects in the oxygen rich and oxygen deficient condition, respectively, indicating a consistency with the experimental results. The calculation results suggest that the oxygen interstitial or oxygen vacancy is correlated with the charge localization, which can introduce holes or electrons as free carriers and subsequently narrow the band gap of monoclinic VO2. These calculations and interpretations concerning the intrinsic point defects would be helpful for developing VO2-based devices through defect modifications.

  16. Critical Role of Monoclinic Polarization Rotation in High-Performance Perovskite Piezoelectric Materials

    Science.gov (United States)

    Liu, Hui; Chen, Jun; Fan, Longlong; Ren, Yang; Pan, Zhao; Lalitha, K. V.; Rödel, Jürgen; Xing, Xianran

    2017-07-01

    High-performance piezoelectric materials constantly attract interest for both technological applications and fundamental research. The understanding of the origin of the high-performance piezoelectric property remains a challenge mainly due to the lack of direct experimental evidence. We perform in situ high-energy x-ray diffraction combined with 2D geometry scattering technology to reveal the underlying mechanism for the perovskite-type lead-based high-performance piezoelectric materials. The direct structural evidence reveals that the electric-field-driven continuous polarization rotation within the monoclinic plane plays a critical role to achieve the giant piezoelectric response. An intrinsic relationship between the crystal structure and piezoelectric performance in perovskite ferroelectrics has been established: A strong tendency of electric-field-driven polarization rotation generates peak piezoelectric performance and vice versa. Furthermore, the monoclinic MA structure is the key feature to superior piezoelectric properties as compared to other structures such as monoclinic MB , rhombohedral, and tetragonal. A high piezoelectric response originates from intrinsic lattice strain, but little from extrinsic domain switching. The present results will facilitate designing high-performance perovskite piezoelectric materials by enhancing the intrinsic lattice contribution with easy and continuous polarization rotation.

  17. Cell Churches and Stem Cell Marketing in South Korea and the United States.

    Science.gov (United States)

    Sipp, Douglas

    2016-05-23

    The commercial provision of putative stem cell-based medical interventions in the absence of conclusive evidence of safety and efficacy has formed the basis of an unregulated industry for more than a decade. Many clinics offering such supposed stem cell treatments include statements about the 'ethical' nature of somatic (often colloquially referred to as 'adult' stem cells) stem cells, in specific contrast to human embryonic stem cells (hESCs), which have been the subject of intensive political, legal, and religious controversy since their first derivation in 1998. Christian groups-both Roman Catholic and evangelical Protestant-in many countries have explicitly promoted the medical potential and current-day successes in the clinical application of somatic stem cells, lending indirect support to the activities of businesses marketing stem cells ahead of evidence. In this article, I make a preliminary examination of how the structures and belief systems of certain churches in South Korea and the United States, both of which are home to significant stem cell marketing industries, has complemented other factors, including national biomedical funding initiatives, international economic rivalries, permissive legal structures, which have lent impetus to a problematic and often exploitative sector of biomedical commerce.

  18. Single fibre and multifibre unit cell analysis of strength and cracking of unidirectional composites

    DEFF Research Database (Denmark)

    Wang, H.W.; Zhou, H.W.; Mishnaevsky, Leon

    2009-01-01

    Numerical simulations of damage evolution in composites reinforced with single and multifibre are presented. Several types of unit cell models are considered: single fibre unit cell, multiple fibre unit cell with one and several damageable sections per fibres, unit cells with homogeneous...... damageable parts in composites (matrix cracks, fibre/matrix interface damage and fibre fracture) was observed in the simulations. The strength of interface begins to influence the deformation behaviour of the cell only after the fibre is broken. In this case, the higher interface layer strength leads...... and inhomogeneous interfaces, etc. Two numerical damage models, cohesive elements, and damageable layers are employed for the simulation of the damage evolution in single fibre and multifibre unit cells. The two modelling approaches were compared and lead to the very close results. Competition among the different...

  19. Automated assembling of single fuel cell units for use in a fuel cell stack

    Science.gov (United States)

    Jalba, C. K.; Muminovic, A.; Barz, C.; Nasui, V.

    2017-05-01

    The manufacturing of PEMFC stacks (POLYMER ELEKTROLYT MEMBRAN Fuel Cell) is nowadays still done by hand. Over hundreds of identical single components have to be placed accurate together for the construction of a fuel cell stack. Beside logistic problems, higher total costs and disadvantages in weight the high number of components produce a higher statistic interference because of faulty erection or material defects and summation of manufacturing tolerances. The saving of costs is about 20 - 25 %. Furthermore, the total weight of the fuel cells will be reduced because of a new sealing technology. Overall a one minute cycle time has to be aimed per cell at the manufacturing of these single components. The change of the existing sealing concept to a bonded sealing is one of the important requisites to get an automated manufacturing of single cell units. One of the important steps for an automated gluing process is the checking of the glue application by using of an image processing system. After bonding the single fuel cell the sealing and electrical function can be checked, so that only functional and high qualitative cells can get into further manufacturing processes.

  20. Unit cell geometry of multiaxial preforms for structural composites

    Science.gov (United States)

    Ko, Frank; Lei, Charles; Rahman, Anisur; Du, G. W.; Cai, Yun-Jia

    1993-01-01

    The objective of this study is to investigate the yarn geometry of multiaxial preforms. The importance of multiaxial preforms for structural composites is well recognized by the industry but, to exploit their full potential, engineering design rules must be established. This study is a step in that direction. In this work the preform geometry for knitted and braided preforms was studied by making a range of well designed samples and studying them by photo microscopy. The structural geometry of the preforms is related to the processing parameters. Based on solid modeling and B-spline methodology a software package is developed. This computer code enables real time structural representations of complex fiber architecture based on the rule of preform manufacturing. The code has the capability of zooming and section plotting. These capabilities provide a powerful means to study the effect of processing variables on the preform geometry. the code also can be extended to an auto mesh generator for downstream structural analysis using finite element method. This report is organized into six sections. In the first section the scope and background of this work is elaborated. In section two the unit cell geometries of braided and multi-axial warp knitted preforms is discussed. The theoretical frame work of yarn path modeling and solid modeling is presented in section three. The thin section microscopy carried out to observe the structural geometry of the preforms is the subject in section four. The structural geometry is related to the processing parameters in section five. Section six documents the implementation of the modeling techniques into the computer code MP-CAD. A user manual for the software is also presented here. The source codes and published papers are listed in the Appendices.

  1. X-ray powder diffraction data and unit cells of ammonium paratungstate tetrahydrate

    NARCIS (Netherlands)

    Put, J.W. van; Verkroost, T.W.; Sonneveld, E.J.

    1990-01-01

    X-Ray powder diffraction data and unit cell parameters of industrially produced, as well as bench scale prepared, ammonium paratungstate tetrahydrate are reported and compared with current Powder Data file (PDF) (1989) patterns. A least-squares refinement resulted in two slightly different unit cell

  2. Coordinate-Invariant Lyddane-Sachs-Teller Relationship for Polar Vibrations in Materials with Monoclinic and Triclinic Crystal Systems.

    Science.gov (United States)

    Schubert, Mathias

    2016-11-18

    A coordinate-invariant generalization of the Lyddane-Sachs-Teller relation is presented for polar vibrations in materials with monoclinic and triclinic crystal systems. The generalization is derived from an eigendielectric displacement vector summation approach, which is equivalent to the microscopic Born-Huang description of polar lattice vibrations in the harmonic approximation. An expression for a general oscillator strength is also described for materials with monoclinic and triclinic crystal systems. A generalized factorized form of the dielectric response characteristic for monoclinic and triclinic materials is proposed. The generalized Lyddane-Sachs-Teller relation is found valid for monoclinic β-Ga_{2}O_{3}, where accurate experimental data became available recently from a comprehensive generalized ellipsometry investigation [Phys. Rev. B 93, 125209 (2016)]. Data for triclinic crystal systems can be measured by generalized ellipsometry as well, and are anticipated to become available soon and results can be compared with the generalized relations presented here.

  3. Growth of orthorhombic and tetragonal modifications of TlInS{sub 2} from its monoclinic phase

    Energy Technology Data Exchange (ETDEWEB)

    Alekperov, O.Z.; Ibragimov, G.B.; Axundov, I.A.; Nadjafov, A.I.; Fakix, A.R. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku (Azerbaijan)

    2009-05-15

    Orthorhombic (O) and tetragonal (T) modifications of TlInS{sub 2} were grown by sulfur vapor annealing of monoclinic (M) crystals. Lattice parameters and syngony of the grown crystals were determined from X-ray investigations (Laue, Weissenberg, rocking crystal and powder diffractions). The lattice parameters a =6.88 A, b=14.04 A, c=4.02 A, Z=4 and a=b=7.76 A, c=26.6 A, Z=20 as well as space groups (SG), P2{sub 1}2{sub 1}2{sub 1} and P4{sub 1}2{sub 1}2 were ascribed to O and T modifications, correspondingly. The transition of M-crystals to O- or T-phase takes place through the intermediate disordered state of M-phase in which the unit packets with c{approx}15 A are randomly positioned along the c-axis. From photoconductivity (PC) edge it was found that the band gap of O-TlInS{sub 2} (E{sub g}=2.52{+-}0.01 eV) is slightly higher whereas that of T-TlInS{sub 2} (E{sub g}=1.87{+-}0.01 eV) is noticeably lower than the band gap of M-TlInS{sub 2}. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. A novel monoclinic phase of impurity-doped CaGa2S4 as a phosphor with high emission intensity

    Directory of Open Access Journals (Sweden)

    Akihiro Suzuki

    2012-06-01

    Full Text Available In the solid-state synthesis of impurity-doped CaGa2S4, calcium tetrathiodigallate(III, a novel phosphor material (denominated as the X-phase, with monoclinic symmetry in the space group P21/a, has been discovered. Its emission intensity is higher than that of the known orthorhombic polymorph of CaGa2S4 crystallizing in the space group Fddd. The asymmetric unit of the monoclinic phase consists of two Ca, four Ga and eight S sites. Each of the Ca and Ga atoms is surrounded by seven and four sulfide ions, respectively, thereby sharing each of the sulfur sites with the nearest neighbours. In contrast, the corresponding sites in the orthorhombic phase are surrounded by eight and four S atoms, respectively. The photoluminescence peaks from Mn2+ and Ce3+ in the doped X-phase, both of which are supposed to replace Ca2+ ions, have been observed to shift towards the high energy side in comparison with those in the orthorhombic phase. This suggests that the crystal field around the Mn2+ and Ce3+ ions in the X-phase is weaker than that in the orthorhombic phase.

  5. Map service: United States Decadal Production History Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map service displays present and past oil and gas production in the United States, as well as the location and intensity of exploratory drilling outside...

  6. Identification of monoclinic calcium pyrophosphate dihydrate and hydroxyapatite in human sclera using Raman microspectroscopy

    DEFF Research Database (Denmark)

    Chen, Ko-Hua; Li, Mei-Jane; Cheng, Wen-Ting;

    2009-01-01

    Raman microspectroscopy was first used to determine the composition of a calcified plaque located at the pterygium-excision site of a 51-year-old female patient's left nasal sclera after surgery. It was unexpectedly found that the Raman spectrum of the calcified sample at 1149, 1108, 1049, 756, 517...... to the characteristic peak at 958/cm of hydroxyapatite (HA). This is the first study to report the spectral biodiagnosis of both monoclinic CPPD and HA co-deposited in the calcified plaque of a patient with sclera dystrophic calcification using Raman microspectroscopy....

  7. Hydrogen Fuel Cell Performance as Telecommunications Backup Power in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprik, Sam [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-03-01

    Working in collaboration with the U.S. Department of Energy (DOE) and industry project partners, the National Renewable Energy Laboratory (NREL) acts as the central data repository for the data collected from real-world operation of fuel cell backup power systems. With American Recovery and Reinvestment Act of 2009 (ARRA) co-funding awarded through DOE's Fuel Cell Technologies Office, more than 1,300 fuel cell units were deployed over a three-plus-year period in stationary, material handling equipment, auxiliary power, and backup power applications. This surpassed a Fuel Cell Technologies Office ARRA objective to spur commercialization of an early market technology by installing 1,000 fuel cell units across several different applications, including backup power. By December 2013, 852 backup power units out of 1,330 fuel cell units deployed were providing backup service, mainly for telecommunications towers. For 136 of the fuel cell backup units, project participants provided detailed operational data to the National Fuel Cell Technology Evaluation Center for analysis by NREL's technology validation team. NREL analyzed operational data collected from these government co-funded demonstration projects to characterize key fuel cell backup power performance metrics, including reliability and operation trends, and to highlight the business case for using fuel cells in these early market applications. NREL's analyses include these critical metrics, along with deployment, U.S. grid outage statistics, and infrastructure operation.

  8. Predicting suitable optoelectronic properties of monoclinic VON semiconductor crystals for photovoltaics using accurate first-principles computations

    KAUST Repository

    Harb, Moussab

    2015-08-26

    Using accurate first-principles quantum calculations based on DFT (including the perturbation theory DFPT) with the range-separated hybrid HSE06 exchange-correlation functional, we predict essential fundamental properties (such as bandgap, optical absorption coefficient, dielectric constant, charge carrier effective masses and exciton binding energy) of two stable monoclinic vanadium oxynitride (VON) semiconductor crystals for solar energy conversion applications. In addition to the predicted band gaps in the optimal range for making single-junction solar cells, both polymorphs exhibit relatively high absorption efficiencies in the visible range, high dielectric constants, high charge carrier mobilities and much lower exciton binding energies than the thermal energy at room temperature. Moreover, their optical absorption, dielectric and exciton dissociation properties are found to be better than those obtained for semiconductors frequently utilized in photovoltaic devices like Si, CdTe and GaAs. These novel results offer a great opportunity for this stoichiometric VON material to be properly synthesized and considered as a new good candidate for photovoltaic applications.

  9. A second monoclinic polymorph of 2-(diformylmethylidene-3,3-dimethyl-2,3-dihydro-1H-indole

    Directory of Open Access Journals (Sweden)

    Hamid Khaledi

    2009-10-01

    Full Text Available The crystal structure of the title compound, C13H13NO2, is a polymorph of the structure first reported by Helliwell et al. [Acta Cryst. (2006, E62, o737-o738]. It is also monoclinic (space group P21/c, but with completely different cell constants. The molecular conformations of these polymorphs differ by a 180° rotation of one formyl group. The present molecule is planar [maximum deviation 0.089 (2 Å] with the exception of the two methyl groups which lie on either side of the plane. There are strong intra- and intermolecular N—H...O hydrogen bonds. The latter link pairs of molecules across crystallographic centers of symmetry. Two aldehyde O atoms are brought close together [2.896 (4 Å in this arrangement but are not hydrogen bonded. In the earlier polymorph, one formyl group is rotated by 180° to yield intermolecular hydrogen bonding and an infinite polymeric chain. The other formyl group is involved in the same intramolecular hydrogen bonding as has been found here.

  10. Atomic Origins of Monoclinic-Tetragonal (Rutile) Phase Transition in Doped VO 2 Nanowires

    KAUST Repository

    Asayesh-Ardakani, Hasti

    2015-10-12

    There has been long-standing interest in tuning the metal-insulator phase transition in vanadium dioxide (VO) via the addition of chemical dopants. However, the underlying mechanisms by which doping elements regulate the phase transition in VO are poorly understood. Taking advantage of aberration-corrected scanning transmission electron microscopy, we reveal the atomistic origins by which tungsten (W) dopants influence the phase transition in single crystalline WVO nanowires. Our atomically resolved strain maps clearly show the localized strain normal to the (122¯) lattice planes of the low W-doped monoclinic structure (insulator). These strain maps demonstrate how anisotropic localized stress created by dopants in the monoclinic structure accelerates the phase transition and lead to relaxation of structure in tetragonal form. In contrast, the strain distribution in the high W-doped VO structure is relatively uniform as a result of transition to tetragonal (metallic) phase. The directional strain gradients are furthermore corroborated by density functional theory calculations that show the energetic consequences of distortions to the local structure. These findings pave the roadmap for lattice-stress engineering of the MIT behavior in strongly correlated materials for specific applications such as ultrafast electronic switches and electro-optical sensors.

  11. Monoclinic tridymite in clast-rich impact melt rock from the Chesapeake Bay impact structure

    Science.gov (United States)

    Jackson, J.C.; Horton, J.W.; Chou, I.-Ming; Belkin, H.E.

    2011-01-01

    X-ray diffraction and Raman spectroscopy confirm a rare terrestrial occurrence of monoclinic tridymite in clast-rich impact melt rock from the Eyreville B drill core in the Chesapeake Bay impact structure. The monoclinic tridymite occurs with quartz paramorphs after tridymite and K-feldspar in a microcrystalline groundmass of devitrified glass and Fe-rich smectite. Electron-microprobe analyses revealed that the tridymite and quartz paramorphs after tridymite contain different amounts of chemical impurities. Inspection by SEM showed that the tridymite crystal surfaces are smooth, whereas the quartz paramorphs contain irregular tabular voids. These voids may represent microporosity formed by volume decrease in the presence of fluid during transformation from tridymite to quartz, or skeletal growth in the original tridymite. Cristobalite locally rims spherulites within the same drill core interval. The occurrences of tridymite and cristobalite appear to be restricted to the thickest clast-rich impact melt body in the core at 1402.02-1407.49 m depth. Their formation and preservation in an alkali-rich, high-silica melt rock suggest initially high temperatures followed by rapid cooling.

  12. Ab initio velocity-field curves in monoclinic β-Ga2O3

    Science.gov (United States)

    Ghosh, Krishnendu; Singisetti, Uttam

    2017-07-01

    We investigate the high-field transport in monoclinic β-Ga2O3 using a combination of ab initio calculations and full band Monte Carlo (FBMC) simulation. Scattering rate calculation and the final state selection in the FBMC simulation use complete wave-vector (both electron and phonon) and crystal direction dependent electron phonon interaction (EPI) elements. We propose and implement a semi-coarse version of the Wannier-Fourier interpolation method [Giustino et al., Phys. Rev. B 76, 165108 (2007)] for short-range non-polar optical phonon (EPI) elements in order to ease the computational requirement in FBMC simulation. During the interpolation of the EPI, the inverse Fourier sum over the real-space electronic grids is done on a coarse mesh while the unitary rotations are done on a fine mesh. This paper reports the high field transport in monoclinic β-Ga2O3 with deep insight into the contribution of electron-phonon interactions and velocity-field characteristics for electric fields ranging up to 450 kV/cm in different crystal directions. A peak velocity of 2 × 107 cm/s is estimated at an electric field of 200 kV/cm.

  13. Imaging metal-like monoclinic phase stabilized by surface coordination effect in vanadium dioxide nanobeam

    Science.gov (United States)

    Li, Zejun; Wu, Jiajing; Hu, Zhenpeng; Lin, Yue; Chen, Qi; Guo, Yuqiao; Liu, Yuhua; Zhao, Yingcheng; Peng, Jing; Chu, Wangsheng; Wu, Changzheng; Xie, Yi

    2017-06-01

    In correlated systems, intermediate states usually appear transiently across phase transitions even at the femtosecond scale. It therefore remains an open question how to determine these intermediate states--a critical issue for understanding the origin of their correlated behaviour. Here we report a surface coordination route to successfully stabilize and directly image an intermediate state in the metal-insulator transition of vanadium dioxide. As a prototype metal-insulator transition material, we capture an unusual metal-like monoclinic phase at room temperature that has long been predicted. Coordinate bonding of L-ascorbic acid molecules with vanadium dioxide nanobeams induces charge-carrier density reorganization and stabilizes metallic monoclinic vanadium dioxide, unravelling orbital-selective Mott correlation for gap opening of the vanadium dioxide metal-insulator transition. Our study contributes to completing phase-evolution pathways in the metal-insulator transition process, and we anticipate that coordination chemistry may be a powerful tool for engineering properties of low-dimensional correlated solids.

  14. Variable defect structures cause the magnetic low-temperature transition in natural monoclinic pyrrhotite

    Science.gov (United States)

    Koulialias, D.; Kind, J.; Charilaou, M.; Weidler, P. G.; Löffler, J. F.; Gehring, A. U.

    2016-02-01

    Non-stoichiometric monoclinic 4C pyrrhotite (Fe7S8) is a major magnetic remanence carrier in the Earth's crust and in extraterrestrial materials. Because of its low-temperature magnetic transition around 30 K also known as Besnus transition, which is considered to be an intrinsic property, this mineral phase is easily detectable in natural samples. Although the physical properties of pyrrhotite have intensively been studied, the mechanism behind the pronounced change in magnetization at the low-temperature transition is still debated. Here we report magnetization experiments on a pyrrhotite crystal (Fe6.6S8) that consists of a 4C and an incommensurate 5C* superstructure that are different in their defect structure. The occurrence of two superstructures is magnetically confirmed by symmetric inflection points in hysteresis measurements above the transition at about 30 K. The disappearance of the inflection points and the associated change of the hysteresis parameters indicate that the two superstructures become strongly coupled to form a unitary magnetic anisotropy system at the transition. From this it follows that the Besnus transition in monoclinic pyrrhotite is an extrinsic magnetic phenomenon with respect to the 4C superstructure and therefore the physics behind it is in fact different from that of the well-known Verwey transition.

  15. Advanced Composite Bipolar Plate for Unitized Regenerative Fuel Cell/Electrolyzer Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an advanced composite bipolar plate is proposed for a unitized regenerative fuel cell and electrolyzer system that operates on pure feed streams...

  16. Super Unit Cells in Aperture-Based Metamaterials

    OpenAIRE

    Dragan Tanasković; Zoran Jakšić; Marko Obradov; Olga Jakšić

    2015-01-01

    An important class of electromagnetic metamaterials are aperture-based metasurfaces. Examples include extraordinary optical transmission arrays and double fishnets with negative refractive index. We analyze a generalization of such metamaterials where a simple aperture is now replaced by a compound object formed by superposition of two or more primitive objects (e.g., rectangles, circles, and ellipses). Thus obtained “super unit cell” shows far richer behavior than the subobjects that compris...

  17. Overview of commercialization of stationary fuel cell power plants in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Hooie, D.T.; Williams, M.C.

    1995-07-01

    In this paper, DOE`s efforts to assist private sector organizations to develop and commercialize stationary fuel cell power plants in the United States are discussed. The paper also provides a snapshot of the status of stationary power fuel cell development occurring in the US, addressing all fuel cell types. This paper discusses general characteristics, system configurations, and status of test units and demonstration projects. The US DOE, Morgantown Energy Technology Center is the lead center for implementing DOE`s program for fuel cells for stationary power.

  18. Dielectric Behavior of Low Microwave Loss Unit Cell for All Dielectric Metamaterial

    OpenAIRE

    Tianhuan Luo; Bo Li; Qian Zhao; Ji Zhou

    2015-01-01

    With a deep study of the metamaterial, its unit cells have been widely extended from metals to dielectrics. The dielectric based unit cells attract much attention because of the advantage of easy preparation, tunability, and higher frequency response, and so forth. Using the conventional solid state method, we prepared a kind of incipient ferroelectrics (calcium titanate, CaTiO3) with higher microwave permittivity and lower loss, which can be successfully used to construct metamaterials. The ...

  19. Orientation relationships between icosahedral clusters in hexagonal MgZn2 and monoclinic Mg4Zn7 phases in Mg-Zn(-Y) alloys

    Science.gov (United States)

    Rosalie, Julian M.; Somekawa, Hidetoshi; Singh, Alok; Mukai, Toshiji

    2011-07-01

    Intermetallic precipitates formed in heat-treated and aged Mg-Zn and Mg-Zn-Y alloys have been investigated via electron microscopy. Coarse spheroidal precipitates formed on deformation twin boundaries contained domains belonging to either the MgZn2 hexagonal Laves phase or the monoclinic Mg4Zn7 phase. Both phases are structurally related to the quasi-crystalline phase formed in Mg-Zn-Y alloys, containing icosahedrally coordinated zinc atoms arranged as a series of broad rhombohedral units. This rhombohedral arrangement was also visible in intragranular precipitates where local regions with the structures of hexagonal MgZn2 and Mg4Zn7 were found. The orientation adopted by the MgZn2 and Mg4Zn7 phases in twin-boundary and intragranular precipitates was such that the icosahedral clusters were aligned similarly. These results highlight the close structural similarities between the precipitates of the Mg-Zn-Y alloy system.

  20. Recent insights into the cell biology of thyroid angiofollicular units.

    OpenAIRE

    Colin, Ides M.; Denef, Jean-François; Lengelé, Benoît; Many, Marie-Christine; Gérard, Anne-Catherine

    2013-01-01

    In thyrocytes, cell polarity is of crucial importance for proper thyroid function. Many intrinsic mechanisms of self-regulation control how the key players involved in thyroid hormone (TH) biosynthesis interact in apical microvilli, so that hazardous biochemical processes may occur without detriment to the cell. In some pathological conditions, this enzymatic complex is disrupted, with some components abnormally activated into the cytoplasm, which can lead to further morphological and functio...

  1. Dominant unit CD34+ cell dose predicts engraftment after double-unit cord blood transplantation and is influenced by bank practice.

    Science.gov (United States)

    Purtill, Duncan; Smith, Katherine; Devlin, Sean; Meagher, Richard; Tonon, Joann; Lubin, Marissa; Ponce, Doris M; Giralt, Sergio; Kernan, Nancy A; Scaradavou, Andromachi; Stevens, Cladd E; Barker, Juliet N

    2014-11-06

    We investigated the unit characteristics associated with engraftment after double-unit cord blood (CB) transplantation (dCBT) and whether these could be reliably identified during unit selection. Cumulative incidence of neutrophil engraftment in 129 myeloablative dCBT recipients was 95% (95% confidence interval: 90-98%). When precryopreservation characteristics were analyzed, the dominant unit CD34(+) cell dose was the only characteristic independently associated with engraftment (hazard ratio, 1.43; P = .002). When postthaw characteristics were also included, only dominant unit infused viable CD34(+) cell dose independently predicted engraftment (hazard ratio, 1.95; P banks were more likely to have low recovery (P banks and units with cryovolumes other than 24.5 to 26.0 mL were more likely to have poor postthaw viability. Precryopreservation CD34(+) cell dose and banking practices should be incorporated into CB unit selection.

  2. Low-temperature magnetic properties of monoclinic pyrrhotite with particular relevance to the Besnus transition

    Science.gov (United States)

    Volk, Michael W. R.; Gilder, Stuart A.; Feinberg, Joshua M.

    2016-12-01

    Monoclinic pyrrhotite (Fe7S8) owes its ferrimagnetism to an ordered array of Fe vacancies. Its magnetic properties change markedly around 30 K, in what is known as the Besnus transition. Plausible explanations for the Besnus transition are either due to changes in crystalline anisotropy from a transformation in crystal symmetry or from the establishment of a two-phase system with magnetic interaction between the two phases. To help resolve this discrepancy, we measured hysteresis loops every 5° and backfield curves every 10° in the basal plane of an oriented single crystal of monoclinic pyrrhotite at 300 K and every 2 K from 50 K through the Besnus transition until 20 K. Between 50 and 30 K, hysteresis loops possess double inflections between crystallographic a-axes and only a single inflection parallel to the a-axes. Magnetization energy calculations and relative differences of the loops show a sixfold symmetry in this temperature range. We propose that the inflections stem from magnetic axis switching, which is both field and temperature dependent, in a manner somewhat analogous to an isotropic point where magnetocrystalline constants change their sign. The Besnus transition is best characterized by changes in magnetic remanence and coercivity over a 6° temperature span (28-34 K) with a maximum rate of change at 30 K. A surprising yet puzzling finding is that the coercivity ratio becomes less than unity below the transition when fourfold symmetry arises. Because the changes in magnetic parameters are linked to the crystal structure, we conclude the Besnus transition owes its origin to a distortion of the crystallographic axes below 30 K rather than an apparition of a two-phase system. An isothermal magnetization of natural pyrrhotite cycled from room temperature to successively lower temperatures through the Besnus transition decreases 2-4 times less than equivalent grain sizes of magnetite, with less than a 10 per cent loss in remanence between 300 and 150 K

  3. Fuel cell repeater unit including frame and separator plate

    Energy Technology Data Exchange (ETDEWEB)

    Yamanis, Jean; Hawkes, Justin R; Chiapetta, Jr., Louis; Bird, Connie E; Sun, Ellen Y; Croteau, Paul F

    2013-11-05

    An example fuel cell repeater includes a separator plate and a frame establishing at least a portion of a flow path that is operative to communicate fuel to or from at least one fuel cell held by the frame relative to the separator plate. The flow path has a perimeter and any fuel within the perimeter flow across the at least one fuel cell in a first direction. The separator plate, the frame, or both establish at least one conduit positioned outside the flow path perimeter. The conduit is outside of the flow path perimeter and is configured to direct flow in a second, different direction. The conduit is fluidly coupled with the flow path.

  4. Strong Bilayer Coupling Induced by the Symmetry Breaking in the Monoclinic Phase of BiS2-Based Superconductors

    Science.gov (United States)

    Ochi, Masayuki; Akashi, Ryosuke; Kuroki, Kazuhiko

    2016-09-01

    We perform first-principles band structure calculations for the tetragonal and monoclinic structures of LaO0.5F0.5BiS2. We find that the Bi 6px,y bands on two BiS2 layers exhibit a sizable splitting at the X = (π ,0,0) and several other k-points for the monoclinic structure. We show that this feature originates from the inter-BiS2 layer coupling strongly enhanced by the symmetry breaking of the crystal structure. The Fermi surface also shows a large splitting and becomes anisotropic with respect to the kx- and ky-directions in the monoclinic structure, whereas it remains almost flat with respect to the kz-direction.

  5. KINETIC STUDY OF SELECTIVE GAS-PHASE OXIDATION OF ISOPROPANOL TO ACETONE USING MONOCLINIC ZRO2 AS A CATALYST

    Directory of Open Access Journals (Sweden)

    Mohammad Sadiq

    2015-08-01

    Full Text Available Zirconia was prepared by a precipitation method and calcined at 723 K, 1023 K, and 1253 K in order to obtain monoclinic zirconia. The prepared zirconia was characterized by XRD, SEM, EDX, surface area and pore size analyzer, and particle size analyzer. Monoclinic ZrO2 as a catalyst was used for the gas-phase oxidation of isopropanol to acetone in a Pyrex-glass-flow-type reactor with a temperature range of 443 K - 473 K. It was found that monoclinic ZrO2 shows remarkable catalytic activity (68% and selectivity (100% for the oxidation of isopropanol to acetone. This kinetic study reveals that the oxidation of isopropanol to acetone follows the L-H mechanism.

  6. Evaluation of the pneumatic tube system for transportation of packed red cell units

    Directory of Open Access Journals (Sweden)

    Supriya Dhar

    2015-01-01

    Full Text Available Background: Pneumatic tube system (PTS is commonly used in hospital settings to transport blood samples to diagnostic laboratories. At our blood center, we receive blood requisitions via the PTS, but units are carried to the ward by human courier. Recently we considered using the PTS for transporting blood units. Since, there are reports of hemolysis in blood samples sent through the PTS, we evaluated this system for transporting red cell units. Aims: The aim was to assess the effect of PTS transport on the quality of packed red cell units. Materials and Methods: A total of 50 red blood cells units (RBC, (25 non-irradiated and 25 irradiated were subjected to transportation through the PTS. The control arm in the study was age-matched RBC units not subjected to PTS transport. Each RBC unit was evaluated for hemoglobin (Hb, lactate dehydrogenase, potassium and plasma hemoglobin (Hb. The paired t-test was used to compare these parameters, and the P value was calculated. Results and Conclusion: The percentage of hemolysis after transportation through PTS was below the recommended guidelines. Delivery of the blood unit to the wrong station, bags lying unattended at the destination were few of the problems that had to be addressed. To conclude, though the PTS is a safe means of transporting blood products with reduction in the turn-around-time, it must be validated before use.

  7. 1-Nitro-4-(4-nitro-phen-oxy)benzene: a second monoclinic polymorph.

    Science.gov (United States)

    Naz, Mehwish; Akhter, Zareen; McKee, Vickie; Nadeem, Arif

    2013-11-01

    In the title compound, C12H8N2O5, the aromatic rings are inclined to one another by 56.14 (7)°. The nitro groups are inclined by to the benzene rings to which they are attached by 3.86 (17) and 9.65 (15)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming a three-dimensional structure. The title compound is a new monoclinic polymorph, crystallizing in space group P21/c. The first polymorph crystallized in space group C2/c and the mol-ecule possesses twofold rotation symmetry. Two low-temperature structures of this polymorph (150 K and 100 K, respectively) have been reported [Meciarova et al. (2004). Private Communication (refcode IXOGAD). CCDC, Cambridge, England, and Dey & Desiraju (2005). Chem. Commun. pp. 2486-2488].

  8. Cubic or monoclinic Y 2O 3:Eu 3+ nanoparticles by one step flame spray pyrolysis

    Science.gov (United States)

    Camenzind, Adrian; Strobel, Reto; Pratsinis, Sotiris E.

    2005-11-01

    Continuous, single-step synthesis of monocrystalline Y 2O 3:Eu 3+ nanophosphor particles (10-25 nm in diameter and 5 wt% Eu) was achieved by flame spray pyrolysis (FSP). The effect of FSP process parameters on materials properties was investigated by X-ray diffraction (XRD), nitrogen adsorption (BET) and transmission electron microscopy (TEM). Photoluminescence (PL) emission were measured as well as the time-resolved PL-intensity decay. Controlled synthesis of monoclinic or cubic Y 2O 3:Eu 3+ nanoparticles was achieved without post-treatment by controlling the high temperature residence time of these particles. The cubic nanoparticles exhibited longer decay times but lower maximum PL intensity than commercial micron-sized bulk Y 2O 3:Eu 3+ phosphor powder.

  9. THE MONOCLINIC PHASE IN PZT: NEW LIGHT ON MORPHOTROPIC PHASE BOUNDARIES

    Energy Technology Data Exchange (ETDEWEB)

    NOHEDA,B.; GONZALO,J.A.; GUO,R.; PARK,S.E.; CROSS,L.E.; COX,D.E.; SHIRANE,G.

    2000-03-09

    A summary of the work recently carried out on the morphotropic phase boundary (MPB) of PZT is presented. By means of x-ray powder diffraction on ceramic samples of excellent quality, the MPB has been successfully characterized by changing temperature in a series of closely spaced compositions. As a result, an unexpected monoclinic phase has been found to exist in between the well-known tetragonal and rhombohedral PZT phases. A detailed structural analysis, together with the investigation of the field effect in this region of compositions, have led to an important advance in understanding the mechanisms responsible for the physical properties of PZT as well as other piezoelectric materials with similar morphotropic phase boundaries.

  10. Electronic structure and optical properties of monoclinic clinobisvanite BiVO4.

    Science.gov (United States)

    Zhao, Zongyan; Li, Zhaosheng; Zou, Zhigang

    2011-03-14

    Monoclinic clinobisvanite bismuth vanadate is an important material with wide applications. However, its electronic structure and optical properties are still not thoroughly understood. Density functional theory calculations were adopted in the present work, to comprehend the band structure, density of states, and projected wave function of BiVO(4). In particular, we put more emphasis upon the intrinsic relationship between its structure and properties. Based on the calculated results, its molecular-orbital bonding structure was proposed. And a significant phenomenon of optical anisotropy was observed in the visible-light region. Furthermore, it was found that its slightly distorted crystal structure enhances the lone-pair impact of Bi 6s states, leading to the special optical properties and excellent photocatalytic activities.

  11. A monoclinic polymorph of (1E,5E-1,5-bis(2-hydroxybenzylidenethiocarbonohydrazide

    Directory of Open Access Journals (Sweden)

    Bonell Schmitt

    2011-08-01

    Full Text Available The title compound, C15H14N4O2S, is a derivative of thioureadihydrazide. In contrast to the previously reported polymorph (orthorhombic, space group Pbca, Z = 8, the current study revealed monoclinic symmetry (space group P21/n, Z = 4. The molecule shows non-crystallographic C2 as well as approximate Cs symmetry. Intramolecular bifurcated O—H...(N,S hydrogen bonds, are present. In the crystal, intermolecular N—H...S hydrogen bonds and C—H...π contacts connect the molecules into undulating chains along the b axis. The shortest centroid–centroid distance between two aromatic systems is 4.5285 (12 Å.

  12. Calculation of thermodynamic, electronic, and optical properties of monoclinic Mg2NiH4

    Energy Technology Data Exchange (ETDEWEB)

    Myers, W.R.; Richardson, T.J.; Rubin, M.D.; Wang, L-W.

    2001-10-01

    Ab initio total-energy density functional theory is used to investigate the low temperature (LT) monoclinic form of Mg2NiH4. The calculated minimum energy geometry of LT Mg2NiH4 is close to that determined from neutron diffraction data, and the NiH4 complex is close to a regular tetrahedron. The enthalpies of the phase change to high temperature (HT) pseudo-cubic Mg2NiH4 and of hydrogen absorption by Mg2Ni are calculated and compared with experimental values. LT Mg2NiH4 is found to be a semiconductor with an indirect band gap of 1.4 eV. The optical dielectric function of LT Mg2NiH4 differs somewhat from that of the HT phase. A calculated thin film transmittance spectrum is consistent with an experimental spectrum.

  13. Control of an afterburner in a diesel fuel cell power unit under variable load

    Science.gov (United States)

    Dolanc, Gregor; Pregelj, Boštjan; Petrovčič, Janko; Samsun, Remzi Can

    2017-01-01

    In this paper, the control system for a catalytic afterburner in a diesel fuel cell auxiliary power unit is presented. The catalytic afterburner is used to burn the non-utilised hydrogen and other possible combustible components of the fuel cell anode off-gas. To increase the energy efficiency of the auxiliary power unit, the thermal energy released in the catalytic afterburner is utilised to generate the steam for the fuel processor. For optimal operation of the power unit in all modes of operation including load change, stable steam generation is required and overall energy balance must be kept within design range. To achieve this, the reaction temperature of the catalytic afterburner must be stable in all modes of operation. Therefore, we propose the afterburner temperature control based on mass and thermal balances. Finally, we demonstrate the control system using the existing prototype of the diesel fuel cell auxiliary power unit.

  14. Monoclinic phase transformation and mechanical durability of zirconia ceramic after fatigue and autoclave aging.

    Science.gov (United States)

    Mota, Yasmine A; Cotes, Caroline; Carvalho, Rodrigo F; Machado, João P B; Leite, Fabíola P P; Souza, Rodrigo O A; Özcan, Mutlu

    2017-10-01

    This study evaluated the influence of two aging procedures on the biaxial flexural strength of yttria-stabilized tetragonal zirconia ceramics. Disc-shaped zirconia specimens and (ZE: E.max ZirCAD, Ivoclar; ZT: Zirkon Translucent, Zirkonzahn) (N = 80) (∅:12 mm; thickness:1.2 mm, ISO 6872) were prepared and randomly divided into four groups (n = 10 per group) according to the aging procedures: C: Control, no aging; M: mechanical cycling (2 × 10(6) cycles/3.8 Hz/200 N); AUT: Aging in autoclave at 134°C, 2 bar for 24 h; AUT + M: Autoclave aging followed by mechanical cycling. After aging, the transformed monoclinic zirconia (%) were evaluated using X-ray diffraction and surface roughness was measured using atomic force microscopy. The average grain size was measured by scanning electron microscopy and the specimens were submitted to biaxial flexural strength testing (1 mm/min, 1000 kgf in water). Data (MPa) were statistically analyzed using 2-way analysis of variance and Tukey's test (α = 0.05). Aging procedures significantly affected (p = 0.000) the flexural strength data but the effect of zirconia type was not significant (p = 0.657). AUTZT (936.4 ± 120.9(b) ) and AUT + MZE (867.2 ± 49.3(b) ) groups presented significantly higher values (p autoclave aging alone or with mechanical aging increased the flexure strength but also induced higher transformation from tetragonal to monoclinic phase in both zirconia materials tested. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1972-1977, 2017. © 2016 Wiley Periodicals, Inc.

  15. Influence of the monoclinic and tetragonal zirconia phases on the water gas shift reaction. A theoretical study.

    Science.gov (United States)

    Cerón, María Luisa; Herrera, Barbara; Araya, Paulo; Gracia, Francisco; Toro-Labbé, Alejandro

    2013-07-01

    We present a theoretical study of the water gas shift reaction taking place on zirconia surfaces modeled by monoclinic and tetragonal clusters. In order to understand the charge transfer between the active species, in this work we analyze the influence of the geometry of monoclinic and tetragonal zirconia using reactivity descriptors such as electronic chemical potential (μ), charge transfer (ΔN) and molecular hardness (η). We have found that the most preferred surface is tetragonal zirconia (tZrO2) indicating also that low charge transfer systems will generate less stable intermediates, that will allow to facilitate desorption process.

  16. Elastic stability and electronic structure of low energy tetragonal and monoclinic PdN2 and PtN2

    Institute of Scientific and Technical Information of China (English)

    Zhao Wen-Jie; Wang Yuan-Xu

    2009-01-01

    This paper studies the elastic and electronic structure properties of two new low-energy structures of PdN2 and PtN2 by first-principles calculations. It finds that tetragonal and monoclinic structures are more stable than a pyrite one. The always positive eigenvalues of the elastic constant matrix confirm that both the tetragonal and monoclinic structures are elastically stable. The origin of the low bulk modulus of the two structures is discussed. The results of the calculated density of states show that both of the two low-energy structures are metallic.

  17. Efficiency of the unit cell in rectangular finned tube arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Buzzoni, Luca; Dall' Olio, Roberto; Spiga, Marco [Bologna Univ., DIENCA, Bologna (Italy)

    1999-11-01

    This paper is aimed at presenting an investigation concerning the efficiency of the single unit in finned air-cooled heat exchangers with staggered and in-line bundles of rectangular ducts, where a hot process fluid flows inside extended-surface tubes and atmospheric air is circulated outside, over the extended surface. The differential energy equation is numerically solved by a finite difference technique, in order to determine the spatial temperature profiles, then the fin efficiency and the augmentation factor are calculated by a simple numerical integration. The results show that the temperature distribution and the fin performance depend on four dimensionless parameters (m,{beta},p{sub x},p{sub y}), the first accounting for the heat transfer condition, the other ones accounting for the geometry of the extended surface (tube aspect ratio and pitches). Several tables are presented, allowing the efficiency of the extended surface to be deduced as a function of the thermal and geometric parameters. (Author)

  18. Quantification of Cell-Free DNA in Red Blood Cell Units in Different Whole Blood Processing Methods

    Directory of Open Access Journals (Sweden)

    Andrew W. Shih

    2016-01-01

    Full Text Available Background. Whole blood donations in Canada are processed by either the red cell filtration (RCF or whole blood filtration (WBF methods, where leukoreduction is potentially delayed in WBF. Fresh WBF red blood cells (RBCs have been associated with increased in-hospital mortality after transfusion. Cell-free DNA (cfDNA is released by neutrophils prior to leukoreduction, degraded during RBC storage, and is associated with adverse patient outcomes. We explored cfDNA levels in RBCs prepared by RCF and WBF and different storage durations. Methods. Equal numbers of fresh (stored ≤14 days and older RBCs were sampled. cfDNA was quantified by spectrophotometry and PicoGreen. Separate regression models determined the association with processing method and storage duration and their interaction on cfDNA. Results. cfDNA in 120 RBC units (73 RCF, 47 WBF were measured. Using PicoGreen, WBF units overall had higher cfDNA than RCF units (p=0.0010; fresh WBF units had higher cfDNA than fresh RCF units (p=0.0093. Using spectrophotometry, fresh RBC units overall had higher cfDNA than older units (p=0.0031; fresh WBF RBCs had higher cfDNA than older RCF RBCs (p=0.024. Conclusion. Higher cfDNA in fresh WBF was observed compared to older RCF blood. Further study is required for association with patient outcomes.

  19. High performance internal reforming unit for high temperature fuel cells

    Science.gov (United States)

    Ma, Zhiwen; Venkataraman, Ramakrishnan; Novacco, Lawrence J.

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  20. The Daniell cell, Ohm's law, and the emergence of the International System of Units

    Science.gov (United States)

    Jayson, Joel S.

    2014-01-01

    Telegraphy originated in the 1830s and 40 s and flourished in the following decades but with a patchwork of electrical standards. Electromotive force was for the most part measured in units of the predominant Daniell cell, but each telegraphy company had their own resistance standard. In 1862, the British Association for the Advancement of Science formed a committee to address this situation. By 1873, they had given definition to the electromagnetic system of units (emu) and defined the practical units of the ohm as 109 emu units of resistance and the volt as 108 emu units of electromotive force. These recommendations were ratified and expanded upon in a series of international congresses held between 1881 and 1904. A proposal by Giovanni Giorgi in 1901 took advantage of a coincidence between the conversion of the units of energy in the emu system (the erg) and in the practical system (the Joule). As it was, the same conversion factor existed between the cgs based emu system and a theretofore undefined MKS system. By introducing another unit X (where X could be any of the practical electrical units), Giorgi demonstrated that a self-consistent MKSX system was tenable without the need for multiplying factors. Ultimately, the ampere was selected as the fourth unit. It took nearly 60 years, but in 1960, Giorgi's proposal was incorporated as the core of the newly inaugurated International System of Units (SI). This article surveys the physics, physicists, and events that contributed to those developments.

  1. [THE MODEL OF NEUROVASCULAR UNIT IN VITRO CONSISTING OF THREE CELLS TYPES].

    Science.gov (United States)

    Khilazheva, E D; Boytsova, E B; Pozhilenkova, E A; Solonchuk, Yu R; Salmina, A B

    2015-01-01

    There are many ways to model blood brain barrier and neurovascular unit in vitro. All existing models have their disadvantages, advantages and some peculiarities of preparation and usage. We obtained the three-cells neurovascular unit model in vitro using progenitor cells isolated from the rat embryos brain (Wistar, 14-16 d). After withdrawal of the progenitor cells the neurospheres were cultured with subsequent differentiation into astrocytes and neurons. Endothelial cells were isolated from embryonic brain too. During the differentiation of progenitor cells the astrocytes monolayer formation occurs after 7-9 d, neurons monolayer--after 10-14 d, endothelial cells monolayer--after 7 d. Our protocol for simultaneous isolation and cultivation of neurons, astrocytes and endothelial cells reduces the time needed to obtain neurovascular unit model in vitro, consisting of three cells types and reduce the number of animals used. It is also important to note the cerebral origin of all cell types, which is also an advantage of our model in vitro.

  2. Importance of unit cells in accurate evaluation of the characteristics of graphene

    Energy Technology Data Exchange (ETDEWEB)

    Sabzyan, Hassan; Sadeghpour, Narges [Isfahan Univ. (Iran, Islamic Republic of). Dept. of Chemistry

    2016-08-01

    Effects of the size of the unit cell on energy, atomic charges, and phonon frequencies of graphene at the Γ point of the Brillouin zone are studied in the absence and presence of an electric field using density functional theory (DFT) methods (LDA and DFT-PBE functionals with Goedecker-Teter-Hutter (GTH) and Troullier-Martins (TM) norm-conserving pseudopotentials). Two types of unit cells containing n{sub c}=4-28 carbon atoms are considered. Results show that stability of graphene increases with increasing size of the unit cell. Energy, atomic charges, and phonon frequencies all converge above n{sub c}=24 for all functional-pseudopotentials used. Except for the LDA-GTH calculations, application of an electric field of 0.4 and 0.9 V/nm strengths does not change the trends with the size of the unit cell but instead slightly decreases the binding energy of graphene. Results of this study show that the choice of unit cell size and type is critical for calculation of reliable characteristics of graphene.

  3. New photosensitizer with phenylenebisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mikroyannidis, J.A., E-mail: mikroyan@chemistry.upatras.gr [Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR-26500 Patras (Greece); Suresh, P. [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur (Raj.) 342005 (India); Roy, M.S. [Defence Laboratory, Jodhpur (Raj.) 342011 (India); Sharma, G.D., E-mail: sharmagd_in@yahoo.com [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur (Raj.) 342005 (India); R and D Centre for Engineering and Science, Jaipur Engineering College, Kukas, Jaipur (Raj.) (India)

    2011-06-30

    Graphical abstract: A novel dye D was synthesized and used as photosensitizer for quasi solid state dye-sensitized solar cells. A power conversion efficiency of 4.4% was obtained which was improved to 5.52% when diphenylphosphinic acid (DPPA) was added as coadsorbent. Display Omitted Highlights: > A new low band gap photosensitizer with cyanovinylene 4-nitrophenyl terminal units was synthesized. > A power conversion efficiency of 4.4% was obtained for the dye-sensitized solar cell based on this photosensitizer. > The power conversion efficiency of the dye-sensitized solar cell was further improved to 5.52% when diphenylphosphinic acid was added as coadsorbent. - Abstract: A new low band gap photosensitizer, D, which contains 2,2'-(1,4-phenylene) bisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units at both sides was synthesized. The two carboxyls attached to the 2,5-positions of the phenylene ring act as anchoring groups. Dye D was soluble in common organic solvents, showed long-wavelength absorption maximum at 620-636 nm and optical band gap of 1.72 eV. The electrochemical parameters, i.e. the highest occupied molecular orbital (HOMO) (-5.1 eV) and the lowest unoccupied molecular orbital (LUMO) (-3.3 eV) energy levels of D show that this dye is suitable as molecular sensitizer. The quasi solid state dye-sensitized solar cell (DSSC) based on D shows a short circuit current (J{sub sc}) of 9.95 mA/cm{sup 2}, an open circuit voltage (V{sub oc}) of 0.70 V, and a fill factor (FF) of 0.64 corresponding to an overall power conversion efficiency (PCE) of 4.40% under 100 mW/cm{sup 2} irradiation. The overall PCE has been further improved to 5.52% when diphenylphosphinic acid (DPPA) coadsorbent is incorporated into the D solution. This increased PCE has been attributed to the enhancement in the electron lifetime and reduced recombination of injected electrons with the iodide ions present in the electrolyte with the use of DPPA as coadsorbant. The

  4. Stability of the monoclinic phase in the ferroelectric perovskite PbZr1-xTixO3

    NARCIS (Netherlands)

    Noheda, B.; Cox, D.E.; Shirane, G.; Guo, R.; Jones, B.; Cross, L.E.

    2000-01-01

    Recent structural studies of ferroelectric PbZr1-xTixO3 (PZT) with x=0.48, have revealed a monoclinic phase in the vicinity of the morphotropic phase boundary (MPB), previously regarded as the boundary separating the rhombohedral and tetragonal regions of the PZT phase diagram. In the present paper,

  5. Application of RPR to Monoclinic and Triclinic Symmetries: Initial Results on Elasticity of Single-Crystal Diopside

    Science.gov (United States)

    Isaak, D. G.; Ohno, I.

    2001-12-01

    In past years, the rectangular parallelepiped resonance (RPR) method has been used to measure single-crystal elastic moduli, and their temperature dependences, of several materials important to geophysics. The high-temperature elastic properties of cubic, orthorhombic, tetragonal, and trigonal crystals, in addition to polycrystals, have all been studied with the RPR method. One feature of the RPR method is that, in principle, all the single-crystal elastic moduli (Cij) can be obtained from a single spectral sweep. However, no materials with crystal symmetry lower than orthorhombic symmetry have been reported in RPR studies. We extend the RPR theory to monoclinic and triclinic crystal symmetries. With these developments, we are able to compute single-crystal resonant spectra using a set of assumed Cij for right-rectangular parallelepiped monoclinic specimens cut along the b and c axes, or monoclinic specimens cut along known, but arbitrary, axes. We present initial results showing the comparison of calculated and measured resonance modes for single-crystal monoclinic diopside. Our measured resonance spectrum on chrome diopside is markedly more consistent with the spectrum calculated from the elasticity data of Collins and Brown (PCM, 26, 7-13, 1998) using a specimen that is 72% diopside than the end-member diopside elasticity data reported by Levien et al. (PCM, 4, 105-113, 1979).

  6. Coexistence of different charge states in Ta-doped monoclinic HfO2: Theoretical and experimental approaches

    DEFF Research Database (Denmark)

    Taylor, M.A.; Alonso, R.E.; Errico, L.A.

    2010-01-01

    A combination of experiments and ab initio quantum-mechanical calculations has been applied to examine hyperfine interactions in Ta-doped hafnium dioxide. Although the properties of monoclinic HfO2 have been the subject of several earlier studies, some aspects remain open. In particular, time dif...

  7. Prediction of stress-strain behavior of ceramic matrix composites using unit cell model

    Directory of Open Access Journals (Sweden)

    Suzuki Takuya

    2015-01-01

    Full Text Available In this study, the elastic modulus and the stress-strain curve of ceramic matrix composites (CMCs were predicted by using the unit cell model that consists of fiber bundles and matrix. The unit cell model was developed based on the observation of cross sections of CMCs. The elastic modulus of CMCs was calculated from the results of finite element analysis using the developed model. The non-linear behavior of stress-strain curve of CMCs was also predicted by taking the degradation of the elastic modulus into consideration, where the degradation was related to the experimentally measured crack density in CMCs. The approach using the unit cell model was applied to two kinds of CMCs, and good agreement was obtained between the experimental and the calculated results.

  8. Reduction in potassium concentration of stored red blood cell units using a resin filter.

    Science.gov (United States)

    Yamada, Chisa; Heitmiller, Eugenie S; Ness, Paul M; King, Karen E

    2010-09-01

    Hyperkalemia is a serious complication of rapid and massive blood transfusion due to high plasma potassium (K) in stored red blood cell (RBC) units. A potassium adsorption filter (PAF) was developed in Japan to remove K by exchanging with sodium (Na). We performed an in vitro evaluation of its efficacy and feasibility of use. Three AS-3 RBC units were filtered by each PAF using gravity; 10 PAFs were tested. Blood group, age, flow rate, and irradiation status were recorded. Total volume, K, Na, Cl, Mg, total Ca (tCa), RBC count, hemoglobin (Hb), hematocrit (Hct), and plasma Hb were measured before and after filtering each unit. Ionized Ca (iCa), pH, and glucose were measured for some units. After filtration, the mean decrease in K was 97.5% in the first RBC unit, 91.2% in the second unit, and 64.4% in the third unit. The mean increases in Na, Mg, and tCa were 33.0, 151.4, and 116.1%, respectively. iCa and pH remained low; glucose was unchanged. RBC count, Hb, and Hct decreased slightly after filtration of first units; plasma Hb was unchanged. After filtration, there was no visual evidence of increased hemolysis or clot formation. The PAF decreased K concentration in stored AS-3 RBC units to minimal levels in the first and second RBC units. Optimally, one filter could be used for 2 RBC units. Although Na increased, the level may not be clinically significant. PAF may be useful for at-risk patients receiving older units or blood that has been stored after gamma irradiation. © 2010 American Association of Blood Banks.

  9. High light-extraction-efficiency OLED based on photonic crystal slab structures with taper unit cells

    Institute of Scientific and Technical Information of China (English)

    YAN Rong-jin; WANG Qing-kang

    2006-01-01

    To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material,and an increase of light-extraction-efficiency to 95.26% is gained.This enhancement is much greater than the traditional PCS with cylinder unit cells (60%-70%).Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed.

  10. Investigation of IrO2/Pt Electrocatalysts in Unitized Regenerative Fuel Cells

    Directory of Open Access Journals (Sweden)

    V. Baglio

    2011-01-01

    Full Text Available IrO2/Pt catalysts (at different concentrations were synthesized by incipient wetness technique and characterized by XRD, XRF, and SEM. Water electrolysis/fuel cell performances were evaluated in a 5 cm2 single cell under Unitized Regenerative Fuel Cell (URFC configuration. The IrO2/Pt composition of 14/86 showed the highest performance for water electrolysis and the lowest one as fuel cell. It is derived that for fuel cell operation an excess of Pt favours the oxygen reduction process whereas IrO2 promotes oxygen evolution. From the present results, it appears that the diffusion characteristics and the reaction rate in fuel cell mode are significantly lower than in the electrolyser mode. This requires the enhancement of the gas diffusion properties of the electrodes and the catalytic properties for cathode operation in fuel cells.

  11. Water proton configurations in structures I, II, and H clathrate hydrate unit cells.

    Science.gov (United States)

    Takeuchi, Fumihito; Hiratsuka, Masaki; Ohmura, Ryo; Alavi, Saman; Sum, Amadeu K; Yasuoka, Kenji

    2013-03-28

    Position and orientation of water protons need to be specified when the molecular simulation studies are performed for clathrate hydrates. Positions of oxygen atoms in water are experimentally determined by X-ray diffraction analysis of clathrate hydrate structures, but positions of water hydrogen atoms in the lattice are disordered. This study reports a determination of the water proton coordinates in unit cell of structure I (sI), II (sII), and H (sH) clathrate hydrates that satisfy the ice rules, have the lowest potential energy configuration for the protons, and give a net zero dipole moment. Possible proton coordinates in the unit cell were chosen by analyzing the symmetry of protons on the hexagonal or pentagonal faces in the hydrate cages and generating all possible proton distributions which satisfy the ice rules. We found that in the sI and sII unit cells, proton distributions with small net dipole moments have fairly narrow potential energy spreads of about 1 kJ∕mol. The total Coulomb potential on a test unit charge placed in the cage center for the minimum energy∕minimum dipole unit cell configurations was calculated. In the sI small cages, the Coulomb potential energy spread in each class of cage is less than 0.1 kJ∕mol, while the potential energy spread increases to values up to 6 kJ∕mol in sH and 15 kJ∕mol in the sII cages. The guest environments inside the cages can therefore be substantially different in the sII case. Cartesian coordinates for oxygen and hydrogen atoms in the sI, sII, and sH unit cells are reported for reference.

  12. Phonon instability and pressure-induced isostructural semiconductor-semimetal transition of monoclinic V O2

    Science.gov (United States)

    He, Huabing; Gao, Heng; Wu, Wei; Cao, Shixun; Hong, Jiawang; Yu, Dehong; Deng, Guochu; Gao, Yanfeng; Zhang, Peihong; Luo, Hongjie; Ren, Wei

    2016-11-01

    Recent experiments have revealed an intriguing pressure-induced isostructural transition of the low temperature monoclinic V O2 and hinted to the existence of a new metallization mechanism in this system. The physics behind this isostructural phase transition and the metallization remains unresolved. In this work, we show that the isostructural transition is a result of pressure-induced instability of a phonon mode that relates to a CaC l2 -type of rotation of the oxygen octahedra, which alleviates, but does not completely remove, the dimerization and zigzagging arrangement of V atoms in the M1 phase. This phonon mode shows an increasing softening with pressure, ultimately leading to an isostructural phase transition characterized by the degree of the rotation of the oxygen octahedra. We also find that this phase transition is accompanied by an anisotropic compression, in excellent agreement with experiments. More interestingly, in addition to the experimentally identified M1' phase, we find a closely related M1 '' phase, which is nearly degenerate with the M1 ' phase. Unlike the M1 ' phase, which has a nearly pressure-independent electronic band gap, the gap of the M1 '' drops quickly at high pressures and vanishes at a theoretical pressure of about 40 GPa.

  13. Monoclinic BiVO{sub 4} with regular morphologies: Hydrothermal synthesis, characterization and photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Li Haibin [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)], E-mail: coastllee@hotmail.com; Liu Guocong [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Department of Chemistry, Yulin Normal University, Yulin 537000 (China); Duan Xuechen [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2009-05-15

    Monoclinic bismuth vanadate (BiVO{sub 4}) samples with regular morphologies were prepared by a facile hydrothermal process with Bi{sub 2}O{sub 3} and NH{sub 4}VO{sub 3} as starting materials. The physical and photophysical properties of the as-prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared spectroscopy (IR), and UV-vis diffuse reflectance spectroscopy (UV-vis). It was found that cuboid-like, square plate-like and flower-like BiVO{sub 4} could be readily obtained by tailoring the pH values of the reaction suspensions in the presence of CTAB. Both pH value and CTAB played crucial roles in the morphology evolution of the as-prepared samples. The bandgaps (E{sub g}) of cuboid-like, square plate-like and flower-like BiVO{sub 4} were 2.39 eV, 2.40 eV and 2.46 eV, respectively. The photocatalytic performance of the as-prepared BiVO{sub 4} was much better than that of P25 for photodegradation of methyl orange under sunlight irradiation. The photocatalytic activities of BiVO{sub 4} samples were highly related to their crystallinities and shapes.

  14. Monoclinic structured BiVO4 nanosheets: hydrothermal preparation, formation mechanism, and coloristic and photocatalytic properties.

    Science.gov (United States)

    Zhang, Li; Chen, Dairong; Jiao, Xiuling

    2006-02-16

    Bismuth vanadate (BiVO(4)) nanosheets have been hydrothermally synthesized in the presence of sodium dodecyl benzene sulfonate (SDBS) as a morphology-directing template. The nanosheets were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) equipped with an X-ray energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), IR spectroscopy, transmission electron microscopy (TEM), and high-resolution TEM (HR-TEM). The BiVO(4) nanosheets had a monoclinic structure, were ca. 10-40 nm thick, and showed a preferred (010) surface orientation. The formation mechanism and the effects of reaction temperature and time on the products were investigated. UV-visible diffuse reflection spectra indicated that the BiVO(4) nanosheets had outstanding spectral selectivity and improved color properties compared with the corresponding bulk materials. Furthermore, the nanosheets showed good visible photocatalytic activities as determined by degradation of N,N,N',N'-tetraethylated rhodamine (RB) under solar irradiation.

  15. Switch effect of the nonquantized intrinsic spin Hall conductivity in monolayered monoclinic transition metal dichalcogenides

    Science.gov (United States)

    Lin, Xianqing; Ni, Jun

    2017-07-01

    First-principles calculations have been performed to study the intrinsic spin Hall effect (SHE) and its behavior under vertical electric field in monoclinic transition metal dichalcogenide monolayers (1T‧-MX2 with M  =  Mo, W and X  =  S, Se, Te). We find that the pristine systems exhibit nonquantized intrinsic spin Hall conductivity (SHC) due to the unconserved spin around the direct band gaps though they have nontrivial band topology. The unconserved spin is attributed to the band crossings at Fermi levels for systems without spin-orbit coupling and the distinct composition of the band states around the crossings. Despite the nonquantization of SHC, calculations with the hybrid functional predict SHC approaching the quantized value in W based systems, especially 1T‧-WTe2, which has been realized in experiments. More interesting, a sharp drop of SHC to almost zero in semiconducting systems induced by vertical electric field is observed at the topological phase transition point, suggesting that such systems exhibit a strong switch effect of SHC. In contrast, the switch effect is weak in semi-metallic systems, where the SHC decreases almost continuously with increasing field strength for the chemical potential around the Fermi levels. Our findings suggest potential applications of the pristine 1T‧-MX2 and those under vertical electric field in spintronics devices by utilizing the intrinsic SHE of their bulk states.

  16. Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure

    Science.gov (United States)

    Sinmyo, Ryosuke; Bykova, Elena; Ovsyannikov, Sergey V.; McCammon, Catherine; Kupenko, Ilya; Ismailova, Leyla; Dubrovinsky, Leonid

    2016-09-01

    Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully recovered at ambient conditions. By means of single crystal X-ray diffraction we determined that Fe7O9 adopts a monoclinic C2/m lattice with the most distorted crystal structure among the binary iron oxides known to date. The synthesis of Fe7O9 opens a new portal to exotic iron-rich (M,Fe)7O9 oxides with unusual stoichiometry and distorted crystal structures. Moreover, the crystal structure and phase relations of such new iron oxide groups may provide new insight into the cycling of volatiles in the Earth’s interior.

  17. Elastic and vibrational properties of monoclinic HfO2 from first-principles study

    Science.gov (United States)

    Wu, Rui; Zhou, Bo; Li, Qian; Jiang, ZhenYi; Wang, WenBo; Ma, WenYan; Zhang, XiaoDong

    2012-03-01

    The elastic and vibrational properties of crystalline monoclinic HfO2 have been investigated using density functional perturbation theory. Using the Voigt and Reuss theory, we estimate the bulk, shear and Young's modulus for polycrystalline HfO2, which agree very well with the available experimental and theoretical data. Additionally, we present a systematic analysis of the elastic properties of HfO2 polymorphs and find the trends in the elastic parameters for the HfO2 structures are consistent with those for the ZrO2 structures. The choice of exchange-correlation functional has an important effect on the results of elastic and vibrational properties. The utilization of Hartwigzen-Goedecker-Hutter type functional is a great improvement on calculation of the zone-centre phonon frequencies, and shows the root-mean-square absolute deviation of 7 cm-1 with experiments. A rigorous assignment of all the Raman modes is achieved by combining symmetry analysis with the first-principles calculations, which helps us to identify the main peak and some other features of Raman spectra. Furthermore, the Raman spectrum of HfO2 powder has been simulated for the first time, providing a theoretical benchmark for the interpretation of the unresolved problems in experimental studies.

  18. Culture of human cells in experimental units for spaceflight impacts on their behavior.

    Science.gov (United States)

    Cazzaniga, Alessandra; Moscheni, Claudia; Maier, Jeanette Am; Castiglioni, Sara

    2017-05-01

    Because space missions produce pathophysiological alterations such as cardiovascular disorders and bone demineralization which are very common on Earth, biomedical research in space is a frontier that holds important promises not only to counterbalance space-associated disorders in astronauts but also to ameliorate the health of Earth-bound population. Experiments in space are complex to design. Cells must be cultured in closed cell culture systems (from now defined experimental units (EUs)), which are biocompatible, functional, safe to minimize any potential hazard to the crew, and with a high degree of automation. Therefore, to perform experiments in orbit, it is relevant to know how closely culture in the EUs reflects cellular behavior under normal growth conditions. We compared the performances in these units of three different human cell types, which were recently space flown, i.e. bone mesenchymal stem cells, micro- and macrovascular endothelial cells. Endothelial cells are only slightly and transiently affected by culture in the EUs, whereas these devices accelerate mesenchymal stem cell reprogramming toward osteogenic differentiation, in part by increasing the amounts of reactive oxygen species. We conclude that cell culture conditions in the EUs do not exactly mimic what happens in a culture dish and that more efforts are necessary to optimize these devices for biomedical experiments in space. Impact statement Cell cultures represent valuable preclinical models to decipher pathogenic circuitries. This is true also for biomedical research in space. A lot has been learnt about cell adaptation and reaction from the experiments performed on many different cell types flown to space. Obviously, cell culture in space has to meet specific requirements for the safety of the crew and to comply with the unique environmental challenges. For these reasons, specific devices for cell culture in space have been developed. It is important to clarify whether these

  19. Magnetic characterization of non-ideal single-domain monoclinic pyrrhotite and its demagnetization under hydrostatic pressure up to 2 GPa with implications for impact demagnetization

    Science.gov (United States)

    Bezaeva, Natalia S.; Chareev, Dmitriy A.; Rochette, Pierre; Kars, Myriam; Gattacceca, Jérôme; Feinberg, Joshua M.; Sadykov, Ravil A.; Kuzina, Dilyara M.; Axenov, Sergey N.

    2016-08-01

    Here we present a comprehensive magnetic characterization of synthesized non-ideal single-domain (SD) monoclinic pyrrhotite (Fe7S8). The samples were in the form of a powder and a powder dispersed in epoxy. "Non-ideal" refers to a powder fraction of predominantly SD size with a minor contribution of small pseudo-single-domain grains; such non-ideal SD pyrrhotite was found to be a remanence carrier in several types of meteorites (carbonaceous chondrites, SNC…), which justifies the usage of synthetic compositions as analogous to natural samples. Data were collected from 5 to 633 K and include low-field magnetic susceptibility (χ0), thermomagnetic curves, major hysteresis loops, back-field remanence demagnetization curves, first-order reversal curves (FORCs), alternating field and pressure demagnetization of saturation isothermal remanent magnetization (SIRM), low temperature data (such as zero-field-cooled and field-cooled remanence datasets together with room temperature SIRM cooling-warming cycles) as well as XRD and Mössbauer spectra. The characteristic Besnus transition is observed at ∼33 K. FORC diagrams indicate interacting SD grains. The application of hydrostatic pressure up to 2 GPa using nonmagnetic high-pressure cells resulted in the demagnetization of the sample by 32-38%. Repeated cycling from 1.8 GPa to atmospheric pressure and back resulted in a total remanence decrease of 44% (after 3 cycles). Pressure demagnetization experiments have important implications for meteorite paleomagnetism and suggest that some published paleointensities of meteorites with non-ideal SD monoclinic pyrrhotite as remanence carrier may be lower limits because shock demagnetization was not accounted for.

  20. Teaching Basic Science Environmentally, The Concept: The cell is basic unit of structure of most organisms.

    Science.gov (United States)

    Busch, Phyllis S.

    1985-01-01

    Suggests simple ways to introduce students to the concept that the cell is the basic unit of structure of most organisms. Mentions materials for microscope study that are readily available and easy to handle, e.g., membranes from between the scales of the onion bulb, thin-leaved plants, pond water, and pollen. (JHZ)

  1. 3D-Printing Crystallographic Unit Cells for Learning Materials Science and Engineering

    Science.gov (United States)

    Rodenbough, Philip P.; Vanti, William B.; Chan, Siu-Wai

    2015-01-01

    Introductory materials science and engineering courses universally include the study of crystal structure and unit cells, which are by their nature highly visual 3D concepts. Traditionally, such topics are explored with 2D drawings or perhaps a limited set of difficult-to-construct 3D models. The rise of 3D printing, coupled with the wealth of…

  2. Predication of Plastic Flow Characteristics in Ferrite/Pearlite Steel Using a Fern Unit Cell Method

    Institute of Scientific and Technical Information of China (English)

    Hong Li; Jingtao Han; Jing Liu; Lv Zhang

    2004-01-01

    The flow stress of ferrite/pearlite steel under uni-axial tension was simulated with finite element method (FEM) by applying commercial software MARC/MENTAT. Flow stress curves of ferrite/pearlite steels were calculated based on unit cell model. The effects of volume fraction, distribution and the aspect ratio of pearlite on tensile properties have been investigated.

  3. 3D-Printing Crystallographic Unit Cells for Learning Materials Science and Engineering

    Science.gov (United States)

    Rodenbough, Philip P.; Vanti, William B.; Chan, Siu-Wai

    2015-01-01

    Introductory materials science and engineering courses universally include the study of crystal structure and unit cells, which are by their nature highly visual 3D concepts. Traditionally, such topics are explored with 2D drawings or perhaps a limited set of difficult-to-construct 3D models. The rise of 3D printing, coupled with the wealth of…

  4. Mitigation of Unwanted Forward Narrow-band Radiation from PCBs with a Metamaterial Unit Cell

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2013-01-01

    Mitigation of EMI from a PCB is obtained through the use of a metamaterial unit cell. The focus is on the reduction of narrow-band radiation in the forward hemisphere when the resonant element is etched on a layer located between the source of radiation and the ground plane. As opposed to previou...

  5. Recovery Act. Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, Gail E. [Delphi Automotive Systems, LLC., Gillingham (United Kingdom)

    2013-09-30

    Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration Project. Summarizing development of Delphi’s next generation SOFC system as the core power plant to prove the viability of the market opportunity for a 3-5 kW diesel SOFC system. Report includes test and demonstration results from testing the diesel APU in a high visibility fleet customer vehicle application.

  6. Experimental broadband absorption enhancement in silicon nanohole structures with optimized complex unit cells.

    Science.gov (United States)

    Lin, Chenxi; Martínez, Luis Javier; Povinelli, Michelle L

    2013-09-09

    We design silicon membranes with nanohole structures with optimized complex unit cells that maximize broadband absorption. We fabricate the optimized design and measure the optical absorption. We demonstrate an experimental broadband absorption about 3.5 times higher than an equally-thick thin film.

  7. Inulin isoforms differ by repeated additions of one crystal unit cell.

    Science.gov (United States)

    Cooper, Peter D; Barclay, Thomas G; Ginic-Markovic, Milena; Gerson, Andrea R; Petrovsky, Nikolai

    2014-03-15

    Inulin isoforms, especially delta inulin, are important biologically as immune activators and clinically as vaccine adjuvants. In exploring action mechanisms, we previously found regular increments in thermal properties of the seven-member inulin isoform series that suggested regular additions of some energetic structural unit. Because the previous isolates carried additional longer chains that masked defining ranges, these were contrasted with new isoform isolates comprising only inulin chain lengths defining that isoform. The new series began with 19 fructose units per chain (alpha-1 inulin), increasing regularly by 6 fructose units per isoform. Thus the 'energetic unit' equates to 6 fructose residues per chain. All isoforms showed indistinguishable X-ray diffraction patterns that were also identical with known inulin crystals. We conclude that an 'energetic unit' equates to one helix turn of 6 fructose units per chain as found in one unit cell of the inulin crystal. Each isoform chain comprised progressively more helix turns plus one additional fructose and glucose residues per chain.

  8. Question 7: the first units of life were not simple cells.

    Science.gov (United States)

    Norris, Vic; Hunding, Axel; Kepes, Francois; Lancet, Doron; Minsky, Abraham; Raine, Derek; Root-Bernstein, Robert; Sriram, K

    2007-10-01

    Five common assumptions about the first cells are challenged by the pre-biotic ecology model and are replaced by the following propositions: firstly, early cells were more complex, more varied and had a greater diversity of constituents than modern cells; secondly, the complexity of a cell is not related to the number of genes it contains, indeed, modern bacteria are as complex as eukaryotes; thirdly, the unit of early life was an 'ecosystem' rather than a 'cell'; fourthly, the early cell needed no genes at all; fifthly, early life depended on non-covalent associations and on catalysts that were not confined to specific reactions. We present here the outlines of a theory that connects findings about modern bacteria with speculations about their origins.

  9. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

    Science.gov (United States)

    McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

    2007-09-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude.

  10. Polarization-dependent angular distribution of the absorption behavior in Ytterbium-doped monoclinic LYB and LGB compounds

    Science.gov (United States)

    Gebremichael, W.; Petit, Y.; Rouzet, S.; Fargues, A.; Veber, P.; Velazquez, M.; Jubera, V.; Canioni, L.; Manek-Hönninger, I.

    2017-02-01

    In this contribution we detail the full characterization of the anisotropy of the absorption properties of two different Yb-doped monoclinic borate compounds under polarized light. The studied crystals are Li6(Gd)0.75Yb0.25(BO3)3 and Li6Y0.75Yb0.25(BO3)3, respectively, grown by the Czochralski method. We focused on the study of their absorption at the zero line transition as a function of the polarization direction of the incident light for two different crystal cuts of each compound. We discuss the different Eigen frames that must be considered in these materials due to their monoclinic character, as well as the optimal crystal orientation for the considered absorption and the potential influences when used as laser materials.

  11. Thermal Hydrolysis Synthesis and Characterization of Monoclinic Metahewettite CaV6O16•3H2O

    Institute of Scientific and Technical Information of China (English)

    LI Lanjie; ZHENG Shili; WANG Shaona; DU Hao; ZHANG Yi

    2014-01-01

    Monoclinic metahewettite CaV6O16•3H2O has been fabricated via thermal hydrolysis of calcium vanadate (Ca10V6O25). High purity calcium vanadate precipitate, featuring column structure with surface area of 8.61 m2/g, can be obtained by reacting sodium orthovanadate (Na3VO4) with calcium oxide at 90℃for 2 h. By acidification of calcium vanadate in hot water at pH of 1.0-3.0, the monoclinic metahewettite crystals with uniform particle distribution, layered structure and nonporous structure can be fabricated. With the well crystallized layered structure, CaV6O16•3H2O may be a potential cathode material for secondary batteries as well as super capacitor materials.

  12. Photocatalytic and photoelectrochemical water oxidation over metal-doped monoclinic BiVO(4) photoanodes.

    Science.gov (United States)

    Parmar, Kanak Pal Singh; Kang, Hyun Joon; Bist, Amita; Dua, Piyush; Jang, Jum Suk; Lee, Jae Sung

    2012-10-01

    The visible-light-induced water oxidation ability of metal-ion-doped BiVO(4) was investigated and of 12 metal ion dopants tested, only W and Mo dramatically enhanced the water photo-oxidation activity of bare BiVO(4); Mo had the highest improvement by a factor of about six. Thus, BiVO(4) and W- or Mo-doped (2 atom %) BiVO(4) photoanodes about 1 μm thick were fabricated onto transparent conducting substrate by a metal-organic decomposition/spin-coating method. Under simulated one sun (air mass 1.5G, 100 mW cm(-2)) and at 1.23 V versus a reversible hydrogen electrode, the highest photocurrent density (J(PH)) of about 2.38 mA cm(-2) was achieved for Mo doping followed by W doping (J(PH) ≈ 1.98 mA cm(-2)), whereas undoped BiVO(4) gave a J(PH) value of about 0.42 mA cm(-2). The photoelectrochemical water oxidation activity of W- and Mo-doped BiVO(4) photoanodes corresponded to the incident photon to current conversion efficiency of about 35 and 40 % respectively. Electrochemical impedance spectroscopy and Mott-Schottky analysis indicated a positive flat band shift of about 30 mV, a carrier concentration 1.6-2 times higher, and a charge-transfer resistance reduced by 3-4-fold for W- or Mo-doped BiVO(4) relative to undoped BiVO(4). Electronic structure calculations revealed that both W and Mo were shallow donors and Mo doping generated superior conductivity to W doping. The photo-oxidation activity of water on BiVO(4) photoanodes (undopedphotocatalytic and photoelectrochemical water oxidation activity of monoclinic BiVO(4) by drastically reducing its charge-transfer resistance and thereby minimizing photoexcited electron-hole pair recombination.

  13. Analysis of tetragonal to monoclinic phase transformation caused by accelerated artificial aging and the effects of microstructure in stabilized zirconia

    Science.gov (United States)

    Lucas, Thomas J.

    This investigation addresses the issue that yttria stabilized zirconia is being used as a dental biomaterial without substantial evidence of its long-term viability. Furthermore, stabilized zirconia (SZ) undergoes low temperature degradation (LTD), which can lead to roughening of the surface. A rougher exterior can lead to increased wear of the antagonist in the oral environment. Despite the LTD concerns, SZ is now widely used in restorative dentistry, including full contour crowns. A comparison of aging methods to determine the role of artificial aging on inducing the transformation has not been extensively studied. Therefore, simulations of the transformation process were investigated by comparing different methods of accelerated aging. The rejected null hypothesis is that the temperature of aging treatment will not affect the time required to cause measurable monoclinic transformation of yttria stabilized zirconia. The transformation of SZ starts at the surface and progresses inward; however, it is unclear whether the progression is constant for different aging conditions. This investigation analyzed the depth of transformation as a function of aging conditions for stabilized zirconia in the top 5-6 mum from the surface. The rejected null hypothesis is that the transformation amount is constant throughout the first six micrometers from the surface. The effects of grain size on the amount of monoclinic transformation were also investigated. This study aimed to determine if the grain size of partially stabilized zirconia affects the amount of monoclinic transformation, surface roughness, and property degradation due to aging. The rejected null hypothesis is that the grain size will not affect the amount of monoclinic transformation, thus have no effect on surface roughening or property degradation. The final part of this study addresses the wear of enamel when opposing zirconia by observing how grain size and aging affected the wear rate of an enamel antagonist

  14. Batteries: encapsulated monoclinic sulfur for stable cycling of li-s rechargeable batteries (adv. Mater. 45/2013).

    Science.gov (United States)

    Moon, San; Jung, Young Hwa; Jung, Wook Ki; Jung, Dae Soo; Choi, Jang Wook; Kim, Do Kyung

    2013-12-03

    On page 6547 Do Kyung Kim, Jang Wook Choi and co-workers describe a highly aligned and carbon-encapsulated sulfur cathode synthesized with an AAO template that exhibits a high and long cycle life, and the best rate capability based on the complete encapsulation of sulfur (physical) and implementation of the monoclinic sulfur phase (chemical). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A switchable pH-differential unitized regenerative fuel cell with high performance

    Science.gov (United States)

    Lu, Xu; Xuan, Jin; Leung, Dennis Y. C.; Zou, Haiyang; Li, Jiantao; Wang, Hailiang; Wang, Huizhi

    2016-05-01

    Regenerative fuel cells are a potential candidate for future energy storage, but their applications are limited by the high cost and poor round-trip efficiency. Here we present a switchable pH-differential unitized regenerative fuel cell capable of addressing both the obstacles. Relying on a membraneless laminar flow-based design, pH environments in the cell are optimized independently for different electrode reactions and are switchable together with the cell process to ensure always favorable thermodynamics for each electrode reaction. Benefiting from the thermodynamic advantages of the switchable pH-differential arrangement, the cell allows water electrolysis at a voltage of 0.57 V, and a fuel cell open circuit voltage of 1.89 V, rendering round-trip efficiencies up to 74%. Under room conditions, operating the cell in fuel cell mode yields a power density of 1.3 W cm-2, which is the highest performance to date for laminar flow-based cells and is comparable to state-of-the-art polymer electrolyte membrane fuel cells.

  16. Study of magnetic and magnetocaloric properties of monoclinic and triclinic spin chain CoV2O6

    Science.gov (United States)

    Nandi, Moumita; Mandal, Prabhat

    We have investigated magnetic and magnetocaloric properties of both monoclinic and triclinic phases of CoV2O6 from magnetization and heat capacity measurements. Conventional and inverse magnetocaloric effects have been observed in both phases of CoV2O6. For a field change from 0 to 7 T, maximum values of magnetic entropy change and adiabatic temperature change reach 11.8 J kg-1 K-1 and 9.5 K respectively for monoclinic CoV2O6 while the corresponding values reach 12.1 J kg-1 K-1 and 13.1 K for triclinic CoVO6. Particularly for triclinic CoVO6, the magnetocaloric parameters are quite large in low or moderate field range. Apart from this, we have constructed magnetic phase diagram of monoclinic CoV2O6 where field-induced complex magnetic phases appear below a certain critical temperature 6 K when external magnetic field is applied along crystallographic easy axis.

  17. Solvothermal, chloroalkoxide-based synthesis of monoclinic WO(3) quantum dots and gas-sensing enhancement by surface oxygen vacancies.

    Science.gov (United States)

    Epifani, Mauro; Comini, Elisabetta; Díaz, Raül; Andreu, Teresa; Genç, Aziz; Arbiol, Jordi; Siciliano, Pietro; Faglia, Guido; Morante, Joan R

    2014-10-01

    We report for the first time the synthesis of monoclinic WO3 quantum dots. A solvothermal processing at 250 °C in oleic acid of W chloroalkoxide solutions was employed. It was shown that the bulk monoclinic crystallographic phase is the stable one even for the nanosized regime (mean size 4 nm). The nanocrystals were characterized by X-ray diffraction, High resolution transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis, Fourier transform infrared and Raman spectroscopy. It was concluded that they were constituted by a core of monoclinic WO3, surface covered by unstable W(V) species, slowly oxidized upon standing in room conditions. The WO3 nanocrystals could be easily processed to prepare gas-sensing devices, without any phase transition up to at least 500 °C. The devices displayed remarkable response to both oxidizing (nitrogen dioxide) and reducing (ethanol) gases in concentrations ranging from 1 to 5 ppm and from 100 to 500 ppm, at low operating temperatures of 100 and 200 °C, respectively. The analysis of the electrical data showed that the nanocrystals were characterized by reduced surfaces, which enhanced both nitrogen dioxide adsorption and oxygen ionosorption, the latter resulting in enhanced ethanol decomposition kinetics.

  18. A fuel cell energy storage system concept for the Space Station Freedom Extravehicular Mobility Unit

    Science.gov (United States)

    Adlhart, Otto J.; Rosso, Matthew J., Jr.; Marmolejo, Jose

    1989-01-01

    An update is given on work to design and build a Fuel Cell Energy Storage System (FCESS) bench-tested unit for the Space Station Freedom Extravehicular Mobility Unit (EMU). Fueled by oxygen and hydride-stored hydrogen, the FCESS is being considered as an alternative to the EMU zinc-silver oxide battery. Superior cycle life and quick recharge are the main attributes of FCESS. The design and performance of a nonventing, 28 V, 34 Ahr system with 7 amp rating are discussed.

  19. Single-unit transfusions and hemoglobin trigger: relative impact on red cell utilization.

    Science.gov (United States)

    Yang, William W; Thakkar, Rajiv N; Gehrie, Eric A; Chen, Weiyun; Frank, Steven M

    2017-05-01

    Patient blood management (PBM) programs can reduce unnecessary transfusions, but the optimal methods used to achieve this effect are unclear. We tested the hypothesis that encouraging single-unit red blood cell (RBC) transfusions in stable patients would have a greater impact on blood use than compliance with a specific hemoglobin (Hb) transfusion trigger alone. We analyzed blood utilization data at three community hospitals without previous PBM efforts before and after implementing a PBM program. Data were analyzed at monthly intervals to determine the relative impact of a "Why give 2 when 1 will do?" campaign promoting single-unit RBC transfusions and simultaneous efforts to promote evidence-based Hb triggers of 7 or 8 g/dL. Univariate and multivariate analyses were used to identify independent effects of these two interventions on overall RBC utilization. Univariate analysis revealed that both the increase in single-unit transfusions (from 38.0% to 70.9%; p utilization. Multivariate analysis showed that the increase in single-unit transfusions was an independent predictor of decreased RBC utilization, but the Hb triggers of both 7 and 8 g/dL were not. Overall, our PBM efforts decreased RBC utilization from 0.254 to 0.185 units/patient (27.2%) across all three hospitals (p = 0.0009). A campaign promoting single-unit RBC transfusions had a greater impact on RBC utilization than did encouraging a restrictive transfusion trigger. © 2016 AABB.

  20. The Daniell Cell, Ohm's Law and the Emergence of the International System of Units

    CERN Document Server

    Jayson, Joel S

    2015-01-01

    Telegraphy originated in the 1830s and 40s and flourished in the following decades, but with a patchwork of electrical standards. Electromotive force was for the most part measured in units of the predominant Daniell cell. Each company had their own resistance standard. In 1862 the British Association for the Advancement of Science formed a committee to address this situation. By 1873 they had given definition to the electromagnetic system of units (emu) and defined the practical units of the ohm as ${10}^9$ emu units of resistance and the volt as ${10}^8$ emu units of electromotive force. These recommendations were ratified and expanded upon in a series of international congresses held between 1881 and 1904. A proposal by Giovanni Giorgi in 1901 took advantage of a coincidence between the conversion of the units of energy in the emu system (the erg) and in the practical system (the joule) in that the same conversion factor existed between the cgs based emu system and a theretofore undefined MKS system. By in...

  1. Regulations in the United States for cell transplantation clinical trials in neurological diseases

    Institute of Scientific and Technical Information of China (English)

    He Zhu; Yuanqing Tan; Qi Gu; Weifang Han; Zhongwen Li; Jason S Meyer; Baoyang Hu

    2015-01-01

    Objective: This study aimed to use a systematic approach to evaluate the current utilization, safety, and effectiveness of cell therapies for neurological diseases in human. And review the present regulations, considering United States (US) as a representative country, for cell transplantation in neurological disease and discuss the challenges facing the field of neurology in the coming decades. Methods:A detailed search was performed in systematic literature reviews of cellular‐based therapies in neurological diseases, using PubMed, web of science, and clinical trials. Regulations of cell therapy products used for clinical trials were searched from the Food and Drug Administration (FDA) and the National Institutes of Health (NIH). Results: Seven most common types of cell therapies for neurological diseases have been reported to be relatively safe with varying degrees of neurological recovery. And a series of regulations in US for cellular therapy was summarized including preclinical evaluations, sourcing material, stem cell manufacturing and characterization, cell therapy product, and clinical trials. Conclusions:Stem cell‐based therapy holds great promise for a cure of such diseases and will value a growing population of patients. However, regulatory permitting activity of the US in the sphere of stem cells, technologies of regenerative medicine and substitutive cell therapy are selective, theoretical and does not fit the existing norm and rules. Compiled well‐defined regulations to guide the application of stem cell products for clinical trials should be formulated.

  2. Fuel cell collaboration in the United States. Follow up report to the Danish Partnership for Hydrogen and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    Fuel cell technology continues to grow in the United States, with strong sales in stationary applications and early markets such as data centers, materials handling equipment, and telecommunications sites. New fuel cell customers include Fortune 500 companies Apple, eBay, Coca-Cola, and Walmart, who will use fuel cells to provide reliable power to data centers, stores, and facilities. Some are purchasing multi-megawatt (MW) systems, including three of the largest non-utility purchases of stationary fuel cells in the world by AT and T, Apple and eBay - 17 MW, 10 MW and 6 MW respectively. Others are replacing fleets of battery forklifts with fuel cells. Sysco, the food distributor, has more than 700 fuel cell-powered forklifts operating at seven facilities, with more on order. Mega-retailer Walmart now operates more than 500 fuel cell forklifts at three warehouses, including a freezer facility. Although federal government budget reduction efforts are impacting a wide range of departments and programs, fuel cell and hydrogen technology continues to be funded, albeit at a lower level than in past years. The Department of Energy (DOE) is currently funding fuel cell and hydrogen R and D and has nearly 300 ongoing projects at companies, national labs, and universities/institutes universities. The American Recovery and Reinvestment Act (ARRA) of 2009 and DOE's Market Transformation efforts have acted as a government ''catalyst'' for market success of emerging technologies. Early market deployments of about 1,400 fuel cells under the ARRA have led to more than 5,000 additional fuel cell purchases by industry with no DOE funding. In addition, interest in Congress remains high. Senators Richard Blumenthal (D-CT), Chris Coons (D-DE), Lindsey Graham (R-SC) and John Hoeven (R-ND) re-launched the bipartisan Senate Fuel Cell and Hydrogen Caucus in August 2012 to promote the continued development and commercialization of hydrogen and fuel cell technologies

  3. Study on Unit Cell Models and the Effective Thermal Conductivities of Silica Aerogel.

    Science.gov (United States)

    Liu, He; Li, Zeng-Yao; Zhao, Xin-Peng; Tao, Wen-Quan

    2015-04-01

    In this paper, two modified unit cell models, truncated octahedron and cubic array of intersecting square rods with 45-degree rotation, are developed in consideration of the tortuous path of heat conduction in solid skeleton of silica aerogel. The heat conduction is analyzed for each model and the expressions of effective thermal conductivity of the modified unit cell models are derived. Considering the random microstructure of silica aerogel, the probability model is presented. We also discuss the effect of the thermal conductivity of aerogel backbone. The effective thermal conductivities calculated by the proposed probability model are in good agreement with available experimental data when the density of the aerogel is 110 kg/m3.

  4. On the Performance of Hybrid PV/Unitized Regenerative Fuel Cell System in the Tropics

    Directory of Open Access Journals (Sweden)

    Salwan Dihrab

    2012-01-01

    Full Text Available Solar hydrogen system is a unique power system that can meet the power requirements for future energy demands. Such a system uses the hydrogen as the energy carrier, which produces energy through the electrolyzer with assistance of the power from the PV during the sunny hours, and then uses stored hydrogen to produce energy through the fuel cell after sunset or on cloudy days. The current study has used premanufactured unitized regenerative fuel cells in which the electrolyzer and the fuel cell function within one cell at different modes. The system components were modeled and the one-day real operational and simulated data has been presented and compared. The measured results showed the ability of the system to meet the proposed load, and the total efficiency was about 4.5%.

  5. BioDiff - a neutron diffractometer optimized for crystals with large unit cell dimensions

    OpenAIRE

    Schrader, Tobias Erich; Ostermann, Andreas; Monkenbusch, Michael; Laatsch, Bernhard; Jüttner, Philipp; Petry, Winfried; Richter, Dieter

    2014-01-01

    The research reactor Heinz Maier-Leibnitz (FRM II) is a modern high flux neutron source which feeds some 30 state of the art neutron beam instruments. Currently 24 are operational, others in commissioning or under construction. The newly built neutron single crystal diffractometer BIODIFF is especially designed to collect data from crystals with large unit cells. The main field of application is the structural analysis of proteins, especially the determination of hydrogen atom positions. BIOD...

  6. Dielectric Behavior of Low Microwave Loss Unit Cell for All Dielectric Metamaterial

    Directory of Open Access Journals (Sweden)

    Tianhuan Luo

    2015-01-01

    Full Text Available With a deep study of the metamaterial, its unit cells have been widely extended from metals to dielectrics. The dielectric based unit cells attract much attention because of the advantage of easy preparation, tunability, and higher frequency response, and so forth. Using the conventional solid state method, we prepared a kind of incipient ferroelectrics (calcium titanate, CaTiO3 with higher microwave permittivity and lower loss, which can be successfully used to construct metamaterials. The temperature and frequency dependence of dielectric constant are also measured under different sintering temperatures. The dielectric spectra showed a slight permittivity decrease with the increase of temperature and exhibited a loss of 0.0005, combined with a higher microwave dielectric constant of ~167 and quality factor Q of 2049. Therefore, CaTiO3 is a kind of versatile and potential metamaterial unit cell. The permittivity of CaTiO3 at higher microwave frequency was also examined in the rectangular waveguide and we got the permittivity of 165, creating a new method to test permittivity at higher microwave frequency.

  7. Structural, mechanical, and electronic properties of monoclinic N{sub 2}H{sub 5}N{sub 3} under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Qi-Jun, Liu; Fu-Sheng, Liu, E-mail: qijunliu@home.swjtu.edu.cn [School of Physical Science and Technology, Southwest Jiaotong University, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Chengdu (China); Bond and Band Engineering Group, Sichuan Provincial Key Laboratory (for Universities) of High Pressure Science and Technology, Southwest Jiaotong University, Chengdu (China); Zheng-Tang, Liu [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an, (China)

    2015-08-15

    Structural, elastic, mechanical, and electronic properties of monoclinic N{sub 2}H{sub 5}N{sub 3} at zero and high pressure have been investigated using the plane-wave ultrasoft pseudopotential method within the density-functional theory (DFT). The pressure dependences of structural parameters, elastic constants, mechanical properties, band gaps, and density of states of monoclinic N{sub 2}H{sub 5}N{sub 3} have been calculated and discussed. The obtained results show that monoclinic N{sub 2}H{sub 5}N{sub 3} is unstable at pressures exceeding the value 126.1 GPa. The ratio of B/G and the Cauchy’s pressure indicate that monoclinic N{sub 2}H{sub 5}N{sub 3} behaves in ductile nature with pressure ranging from 0 to 200 GPa. (author)

  8. High pressure monoclinic phases of Sb{sub 2}Te{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Souza, S.M.; Poffo, C.M.; Triches, D.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Campus Universitario Trindade, S/N, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Lima, J.C. de, E-mail: fsc1jcd@fisica.ufsc.br [Departamento de Fisica, Universidade Federal de Santa Catarina, Campus Universitario Trindade, S/N, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Grandi, T.A. [Departamento de Fisica, Universidade Federal de Santa Catarina, Campus Universitario Trindade, S/N, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Polian, A.; Gauthier, M. [Physique des Milieux Denses, IMPMC, CNRS-UMR 7590, Universite Pierre et Marie Curie-Paris 6, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2012-09-15

    The effect of pressure on nanostructured rhombohedral {alpha}-Sb{sub 2}Te{sub 3} (phase I) was investigated using X-ray diffraction (XRD) and Raman spectroscopy (RS) up to 19.2 and 25.5 GPa, respectively. XRD patterns showed two new high pressure phases (named phases II and III). From a Rietveld refinement of XRD patterns of {alpha}-Sb{sub 2}Te{sub 3}, the unit cell volume as a function of pressure was obtained and the values were fitted to a Birch-Murnaghan equation of state (BM-EOS). The best fit was obtained for bulk modulus B{sub 0}=36.1{+-}0.9 GPa and its derivative B{sub 0}{sup Prime }=6.2{+-}0.4 (not fixed). Using the refined structural data for {alpha}-Sb{sub 2}Te{sub 3}, for pressures up to 9.8 GPa, changes in the angle of succession [Te-Sb-Te-Sb-Te], in the interaromic distances of Sb and Te atoms belonging to this angle of succession and in the interatomic distances of atoms located on the c axis were examined. This analysis revealed an electronic topological transition (ETT) along the a and c axes at close to 3.7 GPa. From the RS spectra, the full widths at half maximum (FWHM) of the Raman active modes of {alpha}-Sb{sub 2}Te{sub 3} were plotted as functions of pressure and showed an ETT along the a and c axes at close to 3.2 GPa. The XRD patterns of phases II and III were well reproduced assuming {beta}-Bi{sub 2}Te{sub 3} and {gamma}-Bi{sub 2}Te{sub 3} structures similar to those reported in the literature for {alpha}-Bi{sub 2}Te{sub 3}.

  9. Template-Engaged In Situ Synthesis of Carbon-Doped Monoclinic Mesoporous BiVO4: Photocatalytic Treatment of Rhodamine B

    Science.gov (United States)

    Yao, Mingming; Gan, Lihua; Liu, Mingxian; Tripathi, Pranav K.; Liu, Yafei; Hu, Zhonghua

    2015-06-01

    In this paper, carbon-doped monoclinic scheelite mesoporous bismuth vanadate was synthesized through template-engaged in situ method. The bismuth nitrate pentahydrate and ammonia metavanadate were used as bismuth and vanadium precursors, respectively, glucose as carbon source, and mesoporous SiO2 aerogel as a hard template. Carbon-doped monoclinic mesoporous BiVO4 were obtained by heat treatment of BiVO4/glucose/template to carbonize glucose and form monoclinic crystal, followed by etching with NaOH solution to remove the SiO2 template. The samples were characterized by x-ray diffraction, N2 adsorption and desorption, UV-visible spectroscopy, Energy dispersive spectrometry, Raman spectroscopy, and Transmission electron microscopy. It was found that the sample with a carbon content of 0.5 wt.% possesses a specific surface area of 10.2 m2/g and has mesoporous structure with the most probable pore size of 13.9 nm. The band gap of carbon-doped monoclinic mesoporous BiVO4 was estimated to be 2.33 eV, indicating the superior photocatalytic activity under visible light. The photocatalytic efficiency of carbon-doped monoclinic mesoporous BiVO4 for the degradation of Rhodamine B under visible light (λ > 400 nm) in 120 min reaches 98.7%, Besides, the carbon-doped monoclinic mesoporous BiVO4 photocatalyst still showed high stability: 85% for Rhodamine B degradation after ten recycles.

  10. Electric field induced cubic to monoclinic phase transition in multiferroic 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Rishikesh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2014-10-20

    The results of x-ray diffraction studies on 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution poled at various electric fields are presented. After poling, significant value of planar electromechanical coupling coefficient (k{sub P}) is observed for this composition having cubic structure in unpoled state. The cubic structure of 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} transforms to monoclinic structure with space group Pm for the poling field ≥5 kV/cm. Large c-axis microscopic lattice strain (1.6%) is achieved at 30 kV/cm poling field. The variation of the c-axis strain and unit cell volume with poling field shows a drastic jump similar to that observed for strain versus electric field curve in (1 − x)Pb(Mg{sub 1/3}Nb{sub 2/3}) O{sub 3}-xPbTiO{sub 3} and (1 − x)Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3}.

  11. Major design issues of molten carbonate fuel cell power generation unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.P.

    1996-04-01

    In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to comply with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.

  12. Cell phone recycling experiences in the United States and potential recycling options in Brazil.

    Science.gov (United States)

    Silveira, Geraldo T R; Chang, Shoou-Yuh

    2010-11-01

    This paper presents an overview of cell phone recycling programs currently available in the United States. At the same time, it also provides analyses of the current recycling situation and possible recycling alternatives for Brazil. Although there are several recycling options in the United States, collection rates are still only 10% of all potential devices because customers are not aware of these possibilities. The whole system is financially based on reselling refurbished cell phones and recycled materials to developing countries which represent an effective and strong market. Several recyclers offer funds to collection partners who are either charities or who work with charities while obtaining the materials that they need in order to run their operations. A mobile phone recycling system for Brazil considering the United States experience and the Extended Producer Responsibility (EPR) principle is suggested. A deposit/refund/advance-recycling fee is proposed which might be implemented as a voluntary industrial initiative managed by PRO Brazil, a producer responsibility organization. One widespread public-private agreement will integrate all mobile phone stakeholders, and environmental education actions and promotional events will promote citizen's participation.

  13. Evolution of Structural, Electronic and Optical Properties of Monoclinic ZrO2 under High Pressure: A First Principles Study

    Institute of Scientific and Technical Information of China (English)

    HOU Ming-Xiu; HE Kai-Hua; ZHENG Guang; HOU Shu-En

    2008-01-01

    The structural, electronic and optical properties of the monoclinic ZrO2 were studied by ab initio calculations based on the density functional theory and pseudopotential method. The calculated lattice parameters and band gap are in agreement with the experimental and other theo- retical values. The evolution of lattice parameters and electronic properties were illustrated under high pressure. Meanwhile, the optical properties, such as adsorption coefficients, imaginary part of dielectric function, and energy loss function, were investigated under both ambient and high pressures.

  14. Synthesis of Monoclinic Form of Gd2-xNaxCuO4 by Direct Precipitation from Molten Salt

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new phase of Gd2-xNaxCuO4 was synthesized by direct precipitation from the mixture of Gd2O3 and CuO in the molten KOH/NaOH/KNO3 solution at temperature as low as 280° C. The resulting precipitate was characterized by using SEM, XRD, EDX, XPS and magnetic method. The XRD data indicate that the precipitated Gd2-xNaxCuO4 is monoclinic with lattice parameters a=8.6816(A), b=3.7233(A). C=6.0796(A), α =γ =90°, β =108.75° and V=186.1(A)3.

  15. Static deformation of two welded monoclinic elastic half-spaces due to a long inclined strike-slip fault

    Indian Academy of Sciences (India)

    Anil Kumar; Sarvajit Singh; Jagdish Singh

    2002-06-01

    Static deformation of two monoclinic elastic half-spaces in welded contact due to a long inclined strike-slip fault situated in one of the half-spaces is studied analytically and numerically. Closedform algebraic expressions for the displacement at any point of the medium are obtained. The variation of the displacement at the interface with the horizontal distance from the fault is studied. The effect of anisotropy on the displacement field is examined. It is found that while the anisotropy of the source half-space has a significant effect on the displacement at the interface, the anisotropy of the other half-space has only a marginal effect.

  16. Planar conjugated polymers containing 9,10-disubstituted phenanthrene units for efficient polymer solar cells.

    Science.gov (United States)

    Li, Guangwu; Kang, Chong; Li, Cuihong; Lu, Zhen; Zhang, Jicheng; Gong, Xue; Zhao, Guangyao; Dong, Huanli; Hu, Wenping; Bo, Zhishan

    2014-06-01

    Four novel conjugated polymers (P1-4) with 9,10-disubstituted phenanthrene (PhA) as the donor unit and 5,6-bis(octyloxy)benzothiadiazole as the acceptor unit are synthesized and characterized. These polymers are of medium bandgaps (2.0 eV), low-lying HOMO energy levels (below -5.3 eV), and high hole mobilities (in the range of 3.6 × 10(-3) to 0.02 cm(2) V(-1) s(-1) ). Bulk heterojunction (BHJ) polymer solar cells (PSCs) with P1-4:PC71 BM blends as the active layer and an alcohol-soluble fullerene derivative (FN-C60) as the interfacial layer between the active layer and cathode give the best power conversion efficiency (PCE) of 4.24%, indicating that 9,10-disubstituted PhA are potential donor materials for high-efficiency BHJ PSCs.

  17. Mechanical properties of regular porous biomaterials made from truncated cube repeating unit cells: Analytical solutions and computational models.

    Science.gov (United States)

    Hedayati, R; Sadighi, M; Mohammadi-Aghdam, M; Zadpoor, A A

    2016-03-01

    Additive manufacturing (AM) has enabled fabrication of open-cell porous biomaterials based on repeating unit cells. The micro-architecture of the porous biomaterials and, thus, their physical properties could then be precisely controlled. Due to their many favorable properties, porous biomaterials manufactured using AM are considered as promising candidates for bone substitution as well as for several other applications in orthopedic surgery. The mechanical properties of such porous structures including static and fatigue properties are shown to be strongly dependent on the type of the repeating unit cell based on which the porous biomaterial is built. In this paper, we study the mechanical properties of porous biomaterials made from a relatively new unit cell, namely truncated cube. We present analytical solutions that relate the dimensions of the repeating unit cell to the elastic modulus, Poisson's ratio, yield stress, and buckling load of those porous structures. We also performed finite element modeling to predict the mechanical properties of the porous structures. The analytical solution and computational results were found to be in agreement with each other. The mechanical properties estimated using both the analytical and computational techniques were somewhat higher than the experimental data reported in one of our recent studies on selective laser melted Ti-6Al-4V porous biomaterials. In addition to porosity, the elastic modulus and Poisson's ratio of the porous structures were found to be strongly dependent on the ratio of the length of the inclined struts to that of the uninclined (i.e. vertical or horizontal) struts, α, in the truncated cube unit cell. The geometry of the truncated cube unit cell approaches the octahedral and cube unit cells when α respectively approaches zero and infinity. Consistent with those geometrical observations, the analytical solutions presented in this study approached those of the octahedral and cube unit cells when

  18. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads Tests

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    1995-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an in balance between the strength (structural integrity....... slender armour units can be studied. by load-cell technique. Moreover, the paper presents DoJos design diagrams for the prediction of both breakage and hydraulic stability...

  19. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1994-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an inbalance between the strength (structural integrity...... on slender armour units can be studied by load-cell technique. Moreover, the paper presents Dolos design diagrams for the prediction of both breakage and hydraulic stability....

  20. National Assessment of Oil and Gas Project - Wind River Basin Province (035) Assessment Units Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS to illustrate the degree of exploration, type of production, and distribution of production...

  1. Failure mechanisms of additively manufactured porous biomaterials: Effects of porosity and type of unit cell.

    Science.gov (United States)

    Kadkhodapour, J; Montazerian, H; Darabi, A Ch; Anaraki, A P; Ahmadi, S M; Zadpoor, A A; Schmauder, S

    2015-10-01

    Since the advent of additive manufacturing techniques, regular porous biomaterials have emerged as promising candidates for tissue engineering scaffolds owing to their controllable pore architecture and feasibility in producing scaffolds from a variety of biomaterials. The architecture of scaffolds could be designed to achieve similar mechanical properties as in the host bone tissue, thereby avoiding issues such as stress shielding in bone replacement procedure. In this paper, the deformation and failure mechanisms of porous titanium (Ti6Al4V) biomaterials manufactured by selective laser melting from two different types of repeating unit cells, namely cubic and diamond lattice structures, with four different porosities are studied. The mechanical behavior of the above-mentioned porous biomaterials was studied using finite element models. The computational results were compared with the experimental findings from a previous study of ours. The Johnson-Cook plasticity and damage model was implemented in the finite element models to simulate the failure of the additively manufactured scaffolds under compression. The computationally predicted stress-strain curves were compared with the experimental ones. The computational models incorporating the Johnson-Cook damage model could predict the plateau stress and maximum stress at the first peak with less than 18% error. Moreover, the computationally predicted deformation modes were in good agreement with the results of scaling law analysis. A layer-by-layer failure mechanism was found for the stretch-dominated structures, i.e. structures made from the cubic unit cell, while the failure of the bending-dominated structures, i.e. structures made from the diamond unit cells, was accompanied by the shearing bands of 45°.

  2. Identified metabolic signature for assessing red blood cell unit quality is associated with endothelial damage markers and clinical outcomes

    DEFF Research Database (Denmark)

    Bordbar, Aarash; Johansson, Pär I.; Paglia, Giuseppe;

    2016-01-01

    BACKGROUND: There has been interest in determining whether older red blood cell (RBC) units have negative clinical effects. Numerous observational studies have shown that older RBC units are an independent factor for patient mortality. However, recently published randomized clinical trials have...

  3. High quality-factor fano metasurface comprising a single resonator unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, Michael B.; Warne, Larry K.; Basilio, Lorena I.; Langston, William L.; Campione, Salvatore; Brener, Igal; Liu, Sheng

    2017-06-20

    A new monolithic resonator metasurface design achieves ultra-high Q-factors while using only one resonator per unit cell. The metasurface relies on breaking the symmetry of otherwise highly symmetric resonators to induce intra-resonator mixing of bright and dark modes (rather than inter-resonator couplings), and is scalable from the near-infrared to radio frequencies and can be easily implemented in dielectric materials. The resulting high-quality-factor Fano metasurface can be used in many sensing, spectral filtering, and modulation applications.

  4. Unit Cell Structure of Crystal Polytypes in InAs and InSb Nanowires

    DEFF Research Database (Denmark)

    Kriegner, Dominik; Panse, Christian; Mandl, Bernhard

    2011-01-01

    , wurtzite, and 4H polytypes for InAs and InSb nanowires, using X-ray diffraction and transmission electron microscopy. The results are compared to density functional theory calculations. Experiment and theory show that the occurrence of hexagonal bilayers tends to stretch the distances of atomic layers...... parallel to the c axis and to reduce the in-plane distances compared to those in zinc blende. The change of the lattice parameters scales linearly with the hexagonality of the polytype, defined as the fraction of bilayers with hexagonal character within one unit cell....

  5. Unit cell modeling in support of interim performance assessment for low level tank waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kline, N.W., Westinghouse Hanford

    1996-08-01

    A unit cell model is used to simulate the base analysis case and related sensitivity cases for the interim performance assessment of low level tank waste disposal. Simulation case results are summarized in terms of fractional contaminant release rates to the vadose zone and to the water table at the unconfined aquifer. Results suggest that the crushed glass water conditioning layer at the top of the facility and the chemical retardation pad at the bottom of the facility can be important components of the facility. Results also suggest that the release rates to the water table are dominated by the release rate from the waste form.

  6. Mild oxide-hydrothermal synthesis of different aspect ratios of monoclinic BiVO{sub 4} nanorods tuned by temperature

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Fengqiang; Wu, Qingsheng; Ma, Jie; Chen, Yijun [Department of Chemistry, Tongji University, Shanghai (China)

    2009-01-15

    The monoclinic scheelite BiVO{sub 4} nanocrystals were easily prepared via an oxide-hydrothermal synthesis (OHS) method directly utilizing bulk-phase materials of V{sub 2}O{sub 5} and Bi{sub 2}O{sub 3} as precursor. In the presence of PEG 4000, the reactions were performed in the mild temperature range from 130 C to 200 C. The products were characterized with FTIR, XRD, TEM and UV-vis DRS. These data clearly demonstrated that monoclinic scheelite structure BiVO{sub 4} could be synthesized by the feasible OHS route. The aspect ratios of nanorods were increased with the synthesized temperature. The as-prepared BiVO{sub 4} showed high photocatalytic activity, which was demonstrated by degradation of methylene blue (MB) solution under visible-light irradiation ({lambda}>420 nm). A growth mechanism of bismuth vanadate was proposed. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Observation of spin glass behavior in monoclinic Li{sub 0.33}MnO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Bie, Xiaofei; Wei, Yingjin; Liu, Lina [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Nikolowski, Kristian; Ehrenberg, Helmut [Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen (Germany); Chen, Hong [College of Physics, Beihua University, Jilin 132013 (China); Wang, Chunzhong; Chen, Gang [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Du, Fei, E-mail: dufei@jlu.edu.cn [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China)

    2013-02-25

    Highlights: Black-Right-Pointing-Pointer The structure of Li{sub 0.33}MnO{sub 2} has been refined with monoclinic phase (space group C2/m). Black-Right-Pointing-Pointer Spin glass has been confirmed by analyzing dc, ac, and time-dependence remanence. Black-Right-Pointing-Pointer Geometrical frustration combined random competition was suggested to be the main cause for spin glass formation. Black-Right-Pointing-Pointer In order to distinguish the spin glass from the superparamagnetism, ac susceptibility under different frequencies is studied. - Abstract: The structure and magnetic properties of Li{sub 0.33}MnO{sub 2} were studied by X-ray diffraction, dc and ac susceptibilities. Li{sub 0.33}MnO{sub 2} belongs to the monoclinic structure with two different Mn sites. The irreversibility and spin freezing behaviors are observed in the dc magnetization curves. The peaks of ac susceptibility display the dependences on the frequency. Both the magnetic relaxation effect and the corresponding analysis confirm a spin glass (SG) transition at low temperature. By evaluating the geometrical frustration parameter, we suggest the spin glass in Li{sub 0.33}MnO{sub 2} originate from the frustration effect combined with the competition among the Mn{sup 3+/4+}-O{sup 2-}-Mn{sup 3+/4+} exchange interaction.

  8. Auxiliary power unit based on a solid oxide fuel cell and fuelled with diesel

    Science.gov (United States)

    Lawrence, Jeremy; Boltze, Matthias

    An auxiliary power unit (APU) is presented that is fuelled with diesel, thermally self-sustaining, and based on a solid oxide fuel cell (SOFC). The APU is rated at 1 kW electrical, and can generate electrical power after a 3 h warm-up phase. System features include a "dry" catalytic partial oxidation (CPOX) diesel reformer, a 30 cell SOFC stack with an open cathode, and a porous-media afterburner. The APU does not require a supply of external water. The SOFC stack is an outcome of a development partnership with H.C. Starck GmbH and Fraunhofer IKTS, and is discussed in detail in an accompanying paper.

  9. Root cause analysis of the degradation in a unitized regenerative fuel cell

    Science.gov (United States)

    Bhosale, Amit C.; Meenakshi, S.; Ghosh, Prakash C.

    2017-03-01

    The present study emphasizes the possible modes of failure of a unitized regenerative fuel cell (URFC) when operated in fuel cell as well as in electrolysis mode at different temperatures viz. 30 °C and 60 °C. The carbon based catalyst (Pt/C) and diffusion layers are used to characterize the degradation of the URFCs. The electrolysis mode of operation is found to dominate the root cause of failure with increase in temperature. Agglomeration and loss of catalyst along with delamination of electrode from membrane are observed. Membrane degradation owing to it's structural as well as chemical damage is seen to be prominent at higher temperature. Characterization techniques such as SEM, TEM and ICP-AES confirm the study showcasing the effect.

  10. Optimizing energy management of decentralized photovoltaic. Fuel cell - direct storage - power supply units

    Energy Technology Data Exchange (ETDEWEB)

    Bocklisch, Thilo; Schufft, Wolfgang; Bocklisch, Steffen [Chemnitz Univ. of Technology (TUC) (Germany)

    2010-07-01

    This paper presents a new optimizing energy management concept for decentralized power supply units. Main goal is the coordinated utilization of dynamically controllable combined-heat-and-power-plants (e.g. fuel cell cogeneration plants) and electrochemical direct storages (e.g. future electric car batteries) for the active balancing of fluctuating renewable energy generation (e.g. building integrated photovoltaics) and fluctuation electricity consumption. The self-utilization and partial storage of renewable energy helps to stabilize the grid in a ''bottom-up'' approach. The new energy mangement concept features a three-layer control structure, which aims for the optimization of the power flows, minimizing the fuel consumption and the dynamic stress imposed onto the fuel cell. (orig.)

  11. Spherical TiO2 aggregates with different building units for dye-sensitized solar cells.

    Science.gov (United States)

    Liu, Zhaohui; Su, Xunjia; Hou, Genliang; Bi, Song; Xiao, Zhou; Jia, Haipeng

    2013-09-07

    Tailoring the architectures of spherical TiO2 aggregates is crucial to obtain superior photovoltaic properties and promote their application in dye-sensitized solar cells (DSSCs). Herein, we synthesized spherical TiO2 aggregates using different building units, including nanocrystallites, nanorods, nanosheets, and nanotubes, via a hydrothermal method, and studied the effect of the building units on the performances of DSSCs. The aggregates assembled by uniform nanosheet and nanotube building units were synthesized with the use of spherical TiO2 nanorod aggregates as titanium sources in an alkaline hydrothermal reaction. Compared with TiO2 nanoparticles, the spherical TiO2 aggregates possess higher surface area, more efficient light scattering ability, and better electron transport properties. Among the four types of spherical TiO2 aggregates; the nanorod, nanotube, and nanosheet aggregates demonstrate better electron transport properties than the nanocrystallite aggregates; the nanotube and nanosheet aggregates exhibit more efficient light scattering than the nanocrystallite and nanorod aggregates; and the nanotube aggregates show the highest surface area. Thus the DSSC based on nanotube aggregates exhibited the highest energy conversion efficiency of 7.48%, which is 16.0%, 9.7%, and 19.5% higher than those of the DSSCs based on the nanosheet, nanorod, and nanocrystallite aggregates, respectively.

  12. Unit cell-based computer-aided manufacturing system for tissue engineering.

    Science.gov (United States)

    Kang, Hyun-Wook; Park, Jeong Hun; Kang, Tae-Yun; Seol, Young-Joon; Cho, Dong-Woo

    2012-03-01

    Scaffolds play an important role in the regeneration of artificial tissues or organs. A scaffold is a porous structure with a micro-scale inner architecture in the range of several to several hundreds of micrometers. Therefore, computer-aided construction of scaffolds should provide sophisticated functionality for porous structure design and a tool path generation strategy that can achieve micro-scale architecture. In this study, a new unit cell-based computer-aided manufacturing (CAM) system was developed for the automated design and fabrication of a porous structure with micro-scale inner architecture that can be applied to composite tissue regeneration. The CAM system was developed by first defining a data structure for the computing process of a unit cell representing a single pore structure. Next, an algorithm and software were developed and applied to construct porous structures with a single or multiple pore design using solid freeform fabrication technology and a 3D tooth/spine computer-aided design model. We showed that this system is quite feasible for the design and fabrication of a scaffold for tissue engineering.

  13. Imaging the impact on cuprate superconductivity of varying the interatomic distances within individual crystal unit cells.

    Science.gov (United States)

    Slezak, J A; Lee, Jinho; Wang, M; McElroy, K; Fujita, K; Andersen, B M; Hirschfeld, P J; Eisaki, H; Uchida, S; Davis, J C

    2008-03-04

    Many theoretical models of high-temperature superconductivity focus only on the doping dependence of the CuO(2)-plane electronic structure. However, such models are manifestly insufficient to explain the strong variations in superconducting critical temperature, T(c), among cuprates that have identical hole density but are crystallographically different outside of the CuO(2) plane. A key challenge, therefore, has been to identify a predominant out-of-plane influence controlling the superconductivity, with much attention focusing on the distance d(A) between the apical oxygen and the planar copper atom. Here we report direct determination of how variations in interatomic distances within individual crystalline unit cells affect the superconducting energy-gap maximum Delta of Bi(2)Sr(2)CaCu(2)O(8+delta). In this material, quasiperiodic variations of unit cell geometry occur in the form of a bulk crystalline "supermodulation." Within each supermodulation period, we find approximately 9 +/- 1% cosinusoidal variation in local Delta that is anticorrelated with the associated d(A) variations. Furthermore, we show that phenomenological consistency would exist between these effects and the random Delta variations found near dopant atoms if the primary effect of the interstitial dopant atom is to displace the apical oxygen so as to diminish d(A) or tilt the CuO(5) pyramid. Thus, we reveal a strong, nonrandom out-of-plane effect on cuprate superconductivity at atomic scale.

  14. Intra-unit-cell nematic charge order in the titanium-oxypnictide family of superconductors

    Science.gov (United States)

    Frandsen, Benjamin A.; Bozin, Emil S.; Hu, Hefei; Zhu, Yimei; Nozaki, Yasumasa; Kageyama, Hiroshi; Uemura, Yasutomo J.; Yin, Wei-Guo; Billinge, Simon J. L.

    2014-12-01

    Understanding the role played by broken-symmetry states such as charge, spin and orbital orders in the mechanism of emergent properties, such as high-temperature superconductivity, is a major current topic in materials research. That the order may be within one unit cell, such as nematic, was only recently considered theoretically, but its observation in the iron-pnictide and doped cuprate superconductors places it at the forefront of current research. Here, we show that the recently discovered BaTi2Sb2O superconductor and its parent compound BaTi2As2O form a symmetry-breaking nematic ground state that can be naturally explained as an intra-unit-cell nematic charge order with d-wave symmetry, pointing to the ubiquity of the phenomenon. These findings, together with the key structural features in these materials being intermediate between the cuprate and iron-pnictide high-temperature superconducting materials, render the titanium oxypnictides an important new material system to understand the nature of nematic order and its relationship to superconductivity.

  15. Fuel cell collaboration in the United States. A report to the Danish Partnership for Hydrogen and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    2011-08-15

    The purpose of this report is to provide members of the Danish Partnership for Hydrogen and Fuel Cells with information regarding collaborative opportunities in the United States. The report is designed to provide an overview of key issues and activities and to provide guidance on strategies for finding U.S. research and commercial partners and gaining access to the U.S. market. Section 1 of this report provides an overview of the key drivers of policy at the federal and state government levels regarding hydrogen and fuel cell technologies and provides a perspective of the U.S. industry and key players. It also suggests three general pathways for accessing U.S. opportunities: enhancing visibility; developing vendor relationships; and establishing a formal presence in the U.S. The next sections summarize focus areas for commercial and research activity that currently are of the greatest interest in the U.S. Section 2 describes major programs within the federal government and national laboratories, and discusses various methods for identifying R and D funding opportunities, with an overview of federal acquisition regulations. Section 3 reviews the efforts of several state governments engaging the fuel cell industry as an economic driver and presents an overview of acquisition at the state level. Section 4 discusses university research and development (R and D) and university-industry partnerships. There are 12 appendices attached to the report. These appendices provide more detailed information regarding the key federal government agencies involved in fuel cells and hydrogen, state-specific policies and activities, national laboratories and universities, and other information regarding the fuel cell and hydrogen industry in the U.S. (Author)

  16. STREAMLINED APPROACH FOR ENVIRONMENTAL RESTORATION PLAN FOR CORRECTIVE ACTION UNIT 116: AREA 25 TEST CELL C FACILITYNEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This Streamlined Approach for Environmental Restoration Plan identifies the activities required for the closure of Corrective Action Unit 116, Area 25 Test Cell C Facility. The Test Cell C Facility is located in Area 25 of the Nevada Test Site approximately 25 miles northwest of Mercury, Nevada.

  17. Impact of the irregular microgeometry of polyurethane foam on the macroscopic acoustic behavior predicted by a unit-cell model.

    Science.gov (United States)

    Doutres, O; Ouisse, M; Atalla, N; Ichchou, M

    2014-10-01

    This paper deals with the prediction of the macroscopic sound absorption behavior of highly porous polyurethane foams using two unit-cell microstructure-based models recently developed by Doutres, Atalla, and Dong [J. Appl. Phys. 110, 064901 (2011); J. Appl. Phys. 113, 054901 (2013)]. In these models, the porous material is idealized as a packing of a tetrakaidecahedra unit-cell representative of the disordered network that constitutes the porous frame. The non-acoustic parameters involved in the classical Johnson-Champoux-Allard model (i.e., porosity, airflow resistivity, tortuosity, etc.) are derived from characteristic properties of the unit-cell and semi-empirical relationships. A global sensitivity analysis is performed on these two models in order to investigate how the variability associated with the measured unit-cell characteristics affects the models outputs. This allows identification of the possible limitations of a unit-cell micro-macro approach due to microstructure irregularity. The sensitivity analysis mainly shows that for moderately and highly reticulated polyurethane foams, the strut length parameter is the key parameter since it greatly impacts three important non-acoustic parameters and causes large uncertainty on the sound absorption coefficient even if its measurement variability is moderate. For foams with a slight inhomogeneity and anisotropy, a micro-macro model associated to cell size measurements should be preferred.

  18. Techno-economic analysis of fuel cell auxiliary power units as alternative to idling

    Science.gov (United States)

    Jain, Semant; Chen, Hsieh-Yeh; Schwank, Johannes

    This paper presents a techno-economic analysis of fuel-cell-based auxiliary power units (APUs), with emphasis on applications in the trucking industry and the military. The APU system is intended to reduce the need for discretionary idling of diesel engines or gas turbines. The analysis considers the options for on-board fuel processing of diesel and compares the two leading fuel cell contenders for automotive APU applications: proton exchange membrane fuel cell and solid oxide fuel cell. As options for on-board diesel reforming, partial oxidation and auto-thermal reforming are considered. Finally, using estimated and projected efficiency data, fuel consumption patterns, capital investment, and operating costs of fuel-cell APUs, an economic evaluation of diesel-based APUs is presented, with emphasis on break-even periods as a function of fuel cost, investment cost, idling time, and idling efficiency. The analysis shows that within the range of parameters studied, there are many conditions where deployment of an SOFC-based APU is economically viable. Our analysis indicates that at an APU system cost of 100 kW -1, the economic break-even period is within 1 year for almost the entire range of conditions. At 500 kW -1 investment cost, a 2-year break-even period is possible except for the lowest end of the fuel consumption range considered. However, if the APU investment cost is 3000 kW -1, break-even would only be possible at the highest fuel consumption scenarios. For Abram tanks, even at typical land delivered fuel costs, a 2-year break-even period is possible for APU investment costs as high as 1100 kW -1.

  19. A monoclinic polymorph of 1,2-bis[(1-methyl-1H-tetrazol-5-ylsulfanyl]ethane (BMTTE

    Directory of Open Access Journals (Sweden)

    Saray Argibay-Otero

    2017-10-01

    Full Text Available The synthesis and crystal structure of a monoclinic (P21/c polymorph of the title compound, C6H10S2N8, are reported. The molecule has pseudo-twofold rotational symmetry, with the tetrazole rings being inclined to one another by 5.50 (6°. In the crystal, molecules are linked by C—H...N hydrogen bonds, forming chains propagating along [101] and enclosing R22(20 ring motifs. The chains are linked by offset π–π interactions involving the tetrazole rings [intercentroid distances vary from 3.3567 (7 to 3.4227 (7 Å], forming layers parallel to the ac plane. The crystal structure of the triclinic polymorph (P\\overline{1} has been described previously [Li et al. (2011. Acta Cryst. E67, o1669].

  20. Electron Distributions in Hexagonal Selenium and Tellurium and Monoclinic Selenium with Dilute Impurities and Associated Nuclear Quadrupole Interactions*.

    Science.gov (United States)

    Maharjan, N. B.; Paudyal, D. D.; Mishra, D. R.; Byahut, S.; Aryal, M. M.; Cho, Hwa-Suck; Scheicher, R. H.; Chow, Lee; Jeong, Junho; Das, T. P.

    2006-03-01

    The electron structures of Selenium chains and rings with Te impurities in hexagonal and monoclinic structures respectively and Se impurities in Te chains in hexagonal lattice have been studied using Hartree-Fock cluster model including many-body effects, including lattice relaxation effects. The calculated electronic wave-functions are utilized to obtain ^77Se and ^125Te nuclear quadrupole coupling constants e^2qQ and asymmetry parameters η and compared with available experimental data from Mossbauer and perturbed angular correlation measurements. From our results, the expected nature of nuclear quadrupole interactions associated with Sb impurities will be discussed. *Supported by NSF US-Nepal Program and UGC Nepal **Also at UCF, Orlando

  1. A simple and low-cost combustion method to prepare monoclinic VO2 with superior thermochromic properties

    Science.gov (United States)

    Cao, Ziyi; Xiao, Xiudi; Lu, Xuanming; Zhan, Yongjun; Cheng, Haoliang; Xu, Gang

    2016-12-01

    In this approach, the VO2 nanoparticles have been successfully fabricated via combusting the low-cost precursor solution consisted of NH4VO3, C2H6O2 and C2H5OH. By the XRD, TEM and XPS analysis, it can be found that the synthetic monoclinic VO2 is single crystal and no impurity is defined. After dispersing the VO2 nanoparticles into the polymer, the solar modulation of VO2-based composite film is up to 12.5% with luminous transmission and haze around 62.2% and 0.5%, respectively. In other words, the composite films show high performance of thermochromic properties. This could open an efficient way to fabricate low-cost and large-scale VO2 (M) nanoparticles and thermochromic films.

  2. Weakly faceted cellular patterns versus growth-induced plastic deformation in thin-sample directional solidification of monoclinic biphenyl.

    Science.gov (United States)

    Börzsönyi, Tamás; Akamatsu, Silvère; Faivre, Gabriel

    2009-11-01

    We present an experimental study of thin-sample directional solidification (T-DS) in impure biphenyl. The platelike growth shape of the monoclinic biphenyl crystals includes two low-mobility (001) facets and four high-mobility {110} facets. Upon T-DS, biphenyl plates oriented with (001) facets parallel to the sample plane can exhibit either a strong growth-induced plastic deformation (GID), or deformation-free weakly faceted (WF) growth patterns. We determine the respective conditions of appearance of these phenomena. GID is shown to be a long-range thermal-stress effect, which disappears when the growth front has a cellular structure. An early triggering of the cellular instability allowed us to avoid GID and study the dynamics of WF patterns as a function of the orientation of the crystal.

  3. Monoclinic β-Li2TiO3: Neutron diffraction study and estimation of Li diffusion pathways

    Science.gov (United States)

    Monchak, M.; Dolotko, O.; Mühlbauer, M. J.; Baran, V.; Senyshyn, A.; Ehrenberg, H.

    2016-11-01

    A neutron powder diffraction study on lithium titanate Li2TiO3 was performed at low temperatures. The monoclinic β-phase has been found to be stable over the whole investigated range of temperatures (4 K-300 K). A smooth and nonlinear increase of the lattice parameters has been observed upon heating and correlated to the behavior of interatomic distances. Lithium diffusion pathways in Li2TiO3 were estimated theoretically on the basis of the obtained structural data using bond-valence modeling. Experimentally diffusion pathways were evaluated by analysis of the negative nuclear scattering densities at 1073 K, which were reconstructed using a maximum entropy method. Although the bond-valence mismatch map indicated a possible Li diffusion either in ab plane or along c direction, analysis of the experimental data revealed that Li migration is thermodynamically less feasible in latter case.

  4. Density functional theory analysis of Raman frequency modes of monoclinic zirconium oxide using Gaussian basis sets and isotopic substitution.

    Science.gov (United States)

    Daramola, Damilola A; Muthuvel, Madhivanan; Botte, Gerardine G

    2010-07-29

    Geometry and vibration properties for monoclinic zirconium oxide were studied using Gaussian basis sets and LDA, GGA, and B3LYP functionals. Bond angles, bond lengths, lattice parameters, and Raman frequencies were calculated and compared to experimental values. Bond angles and lengths were found to agree within experimental standard deviations. The B3LYP gave the best performance of all three functionals with a percent error of 1.35% for the lattice parameters while the average difference between experimental and calculated Raman frequency values was -3 cm(-1). The B3LYP functional was then used to assign the atomic vibrations causing each frequency mode using isotopic substitution of (93.40)Zr for (91.22)Zr and (18.00)O for (16.00)O. This resulted in seven modes assigned to the Zr atom, ten modes to the O atom, and one mode being a mixture of both.

  5. Algorithm and program for precise determination of unit-cell parameters of single crystal taking into account the sample eccentricity

    Science.gov (United States)

    Dudka, A. P.; Smirnova, E. S.; Verin, I. A.; Bolotina, N. B.

    2017-07-01

    A technique has been developed to refine the unit-cell parameters of single crystals with minimization of the influence of instrumental errors on the result. The corresponding computational procedure HuberUB is added to the software package of Huber-5042 diffractometer with a point detector and closedcycle helium cryostat Displex DE-202. The parameters of unit cell, its orientation, the goniometer zero angles, the sample eccentricity, the distances in the goniometer, and the radiation wavelength were refined by the nonlinear least-squares method, which allows imposition of constraints on the unit-cell parameters, depending on the crystal symmetry. The technique is approved on a LuB12 single crystal. The unit-cell parameters are determined in a temperature range of 20-295 K, with an absolute error not larger than 0.0004 Å (the relative error is of 5 × 10-5). The estimates of the unit-cell parameters obtained by the proposed method are evidenced to be unbiased. Some specific features of the behavior of parameters in the ranges of 120-140 and 20-50 K are revealed, which correlate with the anomalies of the physical properties of the crystal.

  6. Exfoliation of natural van der Waals heterostructures to a single unit cell thickness

    Science.gov (United States)

    Velický, Matěj; Toth, Peter S.; Rakowski, Alexander M.; Rooney, Aidan P.; Kozikov, Aleksey; Woods, Colin R.; Mishchenko, Artem; Fumagalli, Laura; Yin, Jun; Zólyomi, Viktor; Georgiou, Thanasis; Haigh, Sarah J.; Novoselov, Kostya S.; Dryfe, Robert A. W.

    2017-02-01

    Weak interlayer interactions in van der Waals crystals facilitate their mechanical exfoliation to monolayer and few-layer two-dimensional materials, which often exhibit striking physical phenomena absent in their bulk form. Here we utilize mechanical exfoliation to produce a two-dimensional form of a mineral franckeite and show that the phase segregation of chemical species into discrete layers at the sub-nanometre scale facilitates franckeite's layered structure and basal cleavage down to a single unit cell thickness. This behaviour is likely to be common in a wider family of complex minerals and could be exploited for a single-step synthesis of van der Waals heterostructures, as an alternative to artificial stacking of individual two-dimensional crystals. We demonstrate p-type electrical conductivity and remarkable electrochemical properties of the exfoliated crystals, showing promise for a range of applications, and use the density functional theory calculations of franckeite's electronic band structure to rationalize the experimental results.

  7. Prognosis of Allogeneic Haematopoietic Stem Cell Recipients Admitted to the Intensive Care Unit

    DEFF Research Database (Denmark)

    Lindgaard, Sidsel Christy; Nielsen, Jonas; Lindmark, Anders

    2016-01-01

    BACKGROUND: Allogeneic haematopoietic stem cell transplantation (HSCT) is a procedure with inherent complications and intensive care may be necessary. We evaluated the short- and long-term outcomes of the HSCT recipients requiring admission to the intensive care unit (ICU). METHODS: We...... ventilation had a statistically significant effect on in-ICU (p = 0.02), 6-month (p = 0.049) and 1-year (p = 0.014) mortality. Renal replacement therapy also had a statistically significant effect on in-hospital (p = 0.038) and 6-month (p = 0.026) mortality. Short ICU admissions, i.e. ... to the ICU was confirmed in our study. Mechanical ventilation, renal replacement therapy and an ICU admission of ≥10 days were each risk factors for mortality in the first year after ICU admission....

  8. An explicit algorithm for fully flexible unit cell simulation with recursive thermostat chains.

    Science.gov (United States)

    Jung, Kwangsub; Cho, Maenghyo

    2008-10-28

    Through the combination of the recursive multiple thermostat (RMT) Nose-Poincare and Parrinello-Rahman methods, the recursive multiple thermostat chained fully flexible unit cell (RMT-NsigmaT) molecular dynamics method is proposed for isothermal-isobaric simulation. The RMT method is known to have the advantage of achieving the ergodicity that is required for canonical sampling of the harmonic oscillator. Thus, an explicit time integration algorithm is developed for RMT-NsigmaT. We examine the ergodicity for various parameters of RMT-NsigmaT using bulk and thin film structures with different numbers of copper atoms and thicknesses in various environments. Through the numerical simulations, we conclude that the RMT-NsigmaT method is advantageous in the cases of lower temperatures.

  9. A diesel fuel processor for fuel-cell-based auxiliary power unit applications

    Science.gov (United States)

    Samsun, Remzi Can; Krekel, Daniel; Pasel, Joachim; Prawitz, Matthias; Peters, Ralf; Stolten, Detlef

    2017-07-01

    Producing a hydrogen-rich gas from diesel fuel enables the efficient generation of electricity in a fuel-cell-based auxiliary power unit. In recent years, significant progress has been achieved in diesel reforming. One issue encountered is the stable operation of water-gas shift reactors with real reformates. A new fuel processor is developed using a commercial shift catalyst. The system is operated using optimized start-up and shut-down strategies. Experiments with diesel and kerosene fuels show slight performance drops in the shift reactor during continuous operation for 100 h. CO concentrations much lower than the target value are achieved during system operation in auxiliary power unit mode at partial loads of up to 60%. The regeneration leads to full recovery of the shift activity. Finally, a new operation strategy is developed whereby the gas hourly space velocity of the shift stages is re-designed. This strategy is validated using different diesel and kerosene fuels, showing a maximum CO concentration of 1.5% at the fuel processor outlet under extreme conditions, which can be tolerated by a high-temperature PEFC. The proposed operation strategy solves the issue of strong performance drop in the shift reactor and makes this technology available for reducing emissions in the transportation sector.

  10. Hydronium perchlorate–dibenzo-18-crown-6 (1/1: monoclinic polymorph

    Directory of Open Access Journals (Sweden)

    Michaela Pojarová

    2010-12-01

    Full Text Available The asymmetric unit of the title compound, H3O+·ClO4−·C20H24O6, contains two molecules/ions of each species. Both dibenzo-18-crown-6 molecules have a complexed hydronium ion inside their cavity with O—H...O and O—H...(O,O links between the two species. The associated perchlorate anions also accept O—H...O hydrogen bonds from the hydronium ion. Both crown ether molecules are present in a butterfly conformation with approximate C2v symmetry and their cavities are closed by the benzene ring of a neighbouring molecule. The packing is consolidated by C—H...O and C—H...π interactions.

  11. A second monoclinic polymorph of ethylenediammonium bis(hydrogen squarate monohydrate

    Directory of Open Access Journals (Sweden)

    Louiza Zenkhri

    2011-05-01

    Full Text Available The title compound, C2H10N22+·2HC4O4−·H2O, a new polymorph of ethylenediammonium bis(hydrogen squarate monohydrate, was synthesized by slow evaporation of an acid solution. The asymetric unit contains two hydrogen squarate anions, two half-molecules of protonated ethylenediamine arranged around a twofold axis and one water molecule. In the crystal, N—H...O and O—H...O hydrogen bonds between the hydrogen squarate anions, protonated N atoms from the amine group and water molecules lead to a three-dimensional framework. In particular, the cohesion between the squarate groups is ensured by very short intermolecular hydrogen bonds bonds. The title compound crystallized together with the previously reported polymorph [Mathew et al. (2002. J. Mol. Struct. 641, 263–279].

  12. Comparison and validation of Logistic Regression and Analytic Hierarchy Process models of landslide susceptibility in monoclinic regions. A case study in Moldavian Plateau, N-E Romania

    Science.gov (United States)

    Ciprian Margarint, Mihai; Niculita, Mihai

    2014-05-01

    , were chosen. As measures of validation for the fit of the model, we have used AUROC value, cross-validation estimates of predictive accuracy and the percent of mapping units correctly classified. For the same sample, the Analytic Hierarchy Process (AHP) approach was applied for landslide susceptibility assessment, using 7 predictors (slope angle, slope aspect, plan and profile curvature, distance to river network, distance to roads, and land use). The validation of the LR and AHP approaches was assessed using the inventories with active landslides for 1978 and 2010 situations. For estimating the level of replicability of the results, an extra-domain sample it was used, situated in the vicinity of the first area, having the same size (90 km2). For the extra-domain area, the same weights obtained for LR approach and the same predictors and weights assigned for the AHP approaches, were used in the modelling. The extra-domain resulted AUROC values are closed with the ones from the original area, but there is small variance, a decrease by 0.07% for LR and by 0.05% for AHP approach. These results allow us to consider that applying both quantitative (LR) and semi-quantitative (AHP) methods for landslide susceptibility assessment at medium scale, in regions with high level of geomorphologic uniformity, such as monoclinic areas, could be applied with good results. Using these two methods for an extra-domain area, we can assess the sensitivity of the input covariates. Also, two maps showing the differences between the two models of landslide susceptibility, both for the first and for the extra-domain sample, were carried out and interpreted.

  13. Fuel cell system including a unit for electrical isolation of a fuel cell stack from a manifold assembly and method therefor

    Science.gov (United States)

    Kelley; Dana A. , Farooque; Mohammad , Davis; Keith

    2007-10-02

    A fuel cell system with improved electrical isolation having a fuel cell stack with a positive potential end and a negative potential, a manifold for use in coupling gases to and from a face of the fuel cell stack, an electrical isolating assembly for electrically isolating the manifold from the stack, and a unit for adjusting an electrical potential of the manifold such as to impede the flow of electrolyte from the stack across the isolating assembly.

  14. Bidirectional relationship of mast cells-neurovascular unit communication in neuroinflammation and its involvement in POCD.

    Science.gov (United States)

    Li, Nana; Zhang, Xiang; Dong, Hongquan; Hu, Youli; Qian, Yanning

    2017-03-30

    Postoperative cognitive dysfunction (POCD) has been hypothesized to be mediated by surgery-induced neuroinflammation, which is also a key element in the pathobiology of neurodegenerative diseases, stroke, and neuropsychiatric disorders. There is extensive communication between the immune system and the central nervous system (CNS). Inflammation resulting from activation of the innate immune system cells in the periphery can impact central nervous system behaviors, such as cognitive performance. Mast cells (MCs), as the"first responders" in the CNS, can initiate, amplify, and prolong other immune and nervous responses upon activation. In addition, MCs and their secreted mediators modulate inflammatory processes in multiple CNS pathologies and can thereby either contribute to neurological damage or confer neuroprotection. Neuroinflammation has been considered to be linked to neurovascular dysfunction in several neurological disorders. This review will provide a brief overview of the bidirectional relationship of MCs-neurovascular unit communication in neuroinflammation and its involvement in POCD, providing a new and unique therapeutic target for the adjuvant treatment of POCD.

  15. Two-Dimensional Simulation of Mass Transfer in Unitized Regenerative Fuel Cells under Operation Mode Switching

    Directory of Open Access Journals (Sweden)

    Lulu Wang

    2016-01-01

    Full Text Available A two-dimensional, single-phase, isothermal, multicomponent, transient model is built to investigate the transport phenomena in unitized regenerative fuel cells (URFCs under the condition of switching from the fuel cell (FC mode to the water electrolysis (WE mode. The model is coupled with an electrochemical reaction. The proton exchange membrane (PEM is selected as the solid electrolyte of the URFC. The work is motivated by the need to elucidate the complex mass transfer and electrochemical process under operation mode switching in order to improve the performance of PEM URFC. A set of governing equations, including conservation of mass, momentum, species, and charge, are considered. These equations are solved by the finite element method. The simulation results indicate the distributions of hydrogen, oxygen, water mass fraction, and electrolyte potential response to the transient phenomena via saltation under operation mode switching. The hydrogen mass fraction gradients are smaller than the oxygen mass fraction gradients. The average mass fractions of the reactants (oxygen and hydrogen and product (water exhibit evident differences between each layer in the steady state of the FC mode. By contrast, the average mass fractions of the reactant (water and products (oxygen and hydrogen exhibit only slight differences between each layer in the steady state of the WE mode. Under either the FC mode or the WE mode, the duration of the transient state is only approximately 0.2 s.

  16. Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Ahmadi

    2015-04-01

    Full Text Available It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primarily because of the challenge in fabricating porous biomaterials with arbitrarily complex morphological designs. In the present work, we studied the relationship between relative density (RD of porous Ti6Al4V EFI alloy and five compressive properties of the material, namely elastic gradient or modulus (Es20–70, first maximum stress, plateau stress, yield stress, and energy absorption. Porous structures with different RD and six different unit cell configurations (cubic (C, diamond (D, truncated cube (TC, truncated cuboctahedron (TCO, rhombic dodecahedron (RD, and rhombicuboctahedron (RCO were fabricated using selective laser melting. Each of the compressive properties increased with increase in RD, the relationship being of a power law type. Clear trends were seen in the influence of unit cell configuration and porosity on each of the compressive properties. For example, in terms of Es20–70, the structures may be divided into two groups: those that are stiff (comprising those made using C, TC, TCO, and RCO unit cell and those that are compliant (comprising those made using D and RD unit cell.

  17. Monoclinic form I of clopidogrel hydrogen sulfate from powder diffraction data

    Directory of Open Access Journals (Sweden)

    Vladimir V. Chernyshev

    2010-08-01

    Full Text Available The asymmetric unit of the title compound, C16H17ClNO2S+·HSO4−, (I [systematic name: (+-(S-5-[(2-chlorophenyl(methoxycarbonylmethyl]-4,5,6,7-tetrahydrothieno[3,2-c]pyridin-5-ium hydrogen sulfate], contains two independent cations of clopidogrel and two independent hydrogensulfate anions. The two independent cations are of similar conformation; however, this differs from that observed in orthorhombic form (II [Bousquet et al. (2003. US Patent No. 6 504 030]. The H—N—Cchiral—H fragment shows a trans conformation in both independent cations in (I and a gauche conformation in (II. In (I, classical intermolecular N—H...O and O—H...O hydrogen bonds link two independent cations and two independent anions into an isolated cluster, in which two cations interact with one anion only via N—H...O hydrogen bonds. Weak intermolecular C—H...O hydrogen bonds further consolidate the crystal packing.

  18. Inhibition of Autophagy Enhances Curcumin United light irradiation-induced Oxidative Stress and Tumor Growth Suppression in Human Melanoma Cells

    Science.gov (United States)

    Niu, Tianhui; Tian, Yan; Mei, Zhusong; Guo, Guangjin

    2016-01-01

    Malignant melanoma is the most aggressive form of skin carcinoma, which possesses fast propagating and highly invasive characteristics. Curcumin is a natural phenol compound that has various biological activities, such as anti-proliferative and apoptosis-accelerating impacts on tumor cells. Unfortunately, the therapeutical activities of Cur are severely hindered due to its extremely low bioavailability. In this study, a cooperative therapy of low concentration Cur combined with red united blue light irradiation was performed to inspect the synergistic effects on the apoptosis, proliferation and autophagy in human melanoma A375 cell. The results showed that red united blue light irradiation efficaciously synergized with Cur to trigger oxidative stress-mediated cell death, induce apoptosis and inhibit cell proliferation. Meanwhile, Western blotting revealed that combined disposure induced the formation of autophagosomes. Conversely, inhibition of the autophagy enhanced apoptosis, obstructed cell cycle arrest and induced reversible proliferation arrest to senescence. These findings suggest that Cur combined with red united blue light irradiation could generate photochemo-preventive effects via enhancing apoptosis and triggering autophagy, and pharmacological inhibition of autophagy convert reversible arrested cells to senescence, therefore reducing the possibility that damaged cells might escape programmed death. PMID:27502897

  19. Electronic structure of ferromagnetic semiconductor material on the monoclinic and rhombohedral ordered double perovskites La{sub 2}FeCoO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Fuh, Huei-Ru; Chang, Ching-Ray [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Graduate Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan (China); Weng, Ke-Chuan [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Wang, Yin-Kuo, E-mail: kant@ntnu.edu.tw [Center for General Education and Department of Physics, National Taiwan Normal University, Taipei 106, Taiwan (China)

    2015-05-07

    Double perovskite La{sub 2}FeCoO{sub 6} with monoclinic structure and rhombohedra structure show as ferromagnetic semiconductor based on density functional theory calculation. The ferromagnetic semiconductor state can be well explained by the superexchange interaction. Moreover, the ferromagnetic semiconductor state remains under the generalized gradient approximation (GGA) and GGA plus onsite Coulomb interaction calculation.

  20. Growth Factor Independence-1 (Gfi1) Is Required for Pancreatic Acinar Unit Formation and Centroacinar Cell Differentiation

    DEFF Research Database (Denmark)

    Qu, Xiaoling; Nyeng, Pia; Xiao, Fan

    2015-01-01

    BACKGROUND & AIMS: The genetic specification of the compartmentalized pancreatic acinar/centroacinar unit is poorly understood. Growth factor independence-1 (Gfi1) is a zinc finger transcriptional repressor that regulates hematopoietic stem cell maintenance, pre-T-cell differentiation, formation...... of pancreatic acinar cells as well as the centroacinar cells (CACs) in Gfi1(-/-) mice when compared with wild-type littermates. Pancreatic endocrine differentiation, islet architecture, and function were unaffected. Organ domain patterning and the formation of ductal cells occurred normally during the murine...... of granulocytes, inner ear hair cells, and the development of secretory cell types in the intestine. As GFI1/Gfi1 is expressed in human and rodent pancreas, we characterized the potential function of Gfi1 in mouse pancreatic development. METHODS: Gfi1 knockout mice were analyzed at histological and molecular...

  1. Molecular replacement study on form-B monoclinic crystal of insulin

    Institute of Scientific and Technical Information of China (English)

    定瑾晖; 万柱礼; 常文瑞; 梁栋材

    1996-01-01

    The form-B monodinic insulin crystal was obtained from the sodium citrate buffer with 1% zinc chloride, keeping phenolic content between 0.76% and 1.25%. Its space group is P21, cell constants are: a = 4.924nm, b=6.094nm, c=4.818nm, β=95.8°. There are 6 insulin molecules which form a hexamer. The initial phase was obtained by using rotation function program of X-PLOR program package and molecular packing program of our laboratory. The molecular model was chosen from 4 zinc bovine insulin hexamer. After the preliminary refinement by using the rnacromolecular rigid body refinement technique, the molecular model was further refined and adjusted by using the energy-minimizing stereochemically restrained least-squared refinement on the difference Fourier maps. The finial R-factor is 214% at 0.3nm resolution, the r.m.s. deviations from standard bond length and bond angle are 0.0022nm and 4.7°, respectively.

  2. Effects of Dexamethasone on Satellite Cells and Tissue Engineered Skeletal Muscle Units.

    Science.gov (United States)

    Syverud, Brian C; VanDusen, Keith W; Larkin, Lisa M

    2016-03-01

    Tissue engineered skeletal muscle has potential for application as a graft source for repairing soft tissue injuries, a model for testing pharmaceuticals, and a biomechanical actuator system for soft robots. However, engineered muscle to date has not produced forces comparable to native muscle, limiting its potential for repair and for use as an in vitro model for pharmaceutical testing. In this study, we examined the trophic effects of dexamethasone (DEX), a glucocorticoid that stimulates myoblast differentiation and fusion into myotubes, on our tissue engineered three-dimensional skeletal muscle units (SMUs). Using our established SMU fabrication protocol, muscle isolates were cultured with three experimental DEX concentrations (5, 10, and 25 nM) and compared to untreated controls. Following seeding onto a laminin-coated Sylgard substrate, the administration of DEX was initiated on day 0 or day 6 in growth medium or on day 9 after the switch to differentiation medium and was sustained until the completion of SMU fabrication. During this process, total cell proliferation was measured with a BrdU assay, and myogenesis and structural advancement of muscle cells were observed through immunostaining for MyoD, myogenin, desmin, and α-actinin. After SMU formation, isometric tetanic force production was measured to quantify function. The histological and functional assessment of the SMU showed that the administration of 10 nM DEX beginning on either day 0 or day 6 yielded optimal SMUs. These optimized SMUs exhibited formation of advanced sarcomeric structure and significant increases in myotube diameter and myotube fusion index, compared with untreated controls. Additionally, the optimized SMUs matured functionally, as indicated by a fivefold rise in force production. In conclusion, we have demonstrated that the addition of DEX to our process of engineering skeletal muscle tissue improves myogenesis, advances muscle structure, and increases force production in the

  3. Progress in human embryonic stem cell research in the United States between 2001 and 2010.

    Directory of Open Access Journals (Sweden)

    Keyvan Vakili

    Full Text Available On August 9th, 2001, the federal government of the United States announced a policy restricting federal funds available for research on human embryonic stem cell (hESCs out of concern for the "vast ethical mine fields" associated with the creation of embryos for research purposes. Until the policy was repealed on March 9th, 2009, no U.S. federal funds were available for research on hESCs extracted after August 9, 2001, and only limited federal funds were available for research on a subset of hESC lines that had previously been extracted. This paper analyzes how the 2001 U.S. federal funding restrictions influenced the quantity and geography of peer-reviewed journal publications on hESC. The primary finding is that the 2001 policy did not have a significant aggregate effect on hESC research in the U.S. After a brief lag in early 2000s, U.S. hESC research maintained pace with other areas of stem cell and genetic research. The policy had several other consequences. First, it was tied to increased hESC research funding within the U.S. at the state level, leading to concentration of related activities in a relatively small number of states. Second, it stimulated increased collaborative research between US-based scientists and those in countries with flexible policies toward hESC research (including Canada, the U.K., Israel, China, Spain, and South Korea. Third, it encouraged independent hESC research in countries without restrictions.

  4. Highly Efficient and Exceptionally Durable CO2 Photoreduction to Methanol over Freestanding Defective Single-Unit-Cell Bismuth Vanadate Layers.

    Science.gov (United States)

    Gao, Shan; Gu, Bingchuan; Jiao, Xingchen; Sun, Yongfu; Zu, Xiaolong; Yang, Fan; Zhu, Wenguang; Wang, Chengming; Feng, Zimou; Ye, Bangjiao; Xie, Yi

    2017-03-08

    Unearthing an ideal model for disclosing the role of defect sites in solar CO2 reduction remains a great challenge. Here, freestanding gram-scale single-unit-cell o-BiVO4 layers are successfully synthesized for the first time. Positron annihilation spectrometry and X-ray fluorescence unveil their distinct vanadium vacancy concentrations. Density functional calculations reveal that the introduction of vanadium vacancies brings a new defect level and higher hole concentration near Fermi level, resulting in increased photoabsorption and superior electronic conductivity. The higher surface photovoltage intensity of single-unit-cell o-BiVO4 layers with rich vanadium vacancies ensures their higher carriers separation efficiency, further confirmed by the increased carriers lifetime from 74.5 to 143.6 ns revealed by time-resolved fluorescence emission decay spectra. As a result, single-unit-cell o-BiVO4 layers with rich vanadium vacancies exhibit a high methanol formation rate up to 398.3 μmol g(-1) h(-1) and an apparent quantum efficiency of 5.96% at 350 nm, much larger than that of single-unit-cell o-BiVO4 layers with poor vanadium vacancies, and also the former's catalytic activity proceeds without deactivation even after 96 h. This highly efficient and spectrally stable CO2 photoconversion performances hold great promise for practical implementation of solar fuel production.

  5. Investigation of potential fluctuating intra-unit cell magnetic order in cuprates by μ SR

    Science.gov (United States)

    Pal, A.; Akintola, K.; Potma, M.; Ishikado, M.; Eisaki, H.; Hardy, W. N.; Bonn, D. A.; Liang, R.; Sonier, J. E.

    2016-10-01

    We report low temperature muon spin relaxation (μ SR ) measurements of the high-transition-temperature (Tc) cuprate superconductors Bi2 +xSr2 -xCaCu2O8 +δ and YBa2Cu3O6.57 , aimed at detecting the mysterious intra-unit cell (IUC) magnetic order that has been observed by spin-polarized neutron scattering in the pseudogap phase of four different cuprate families. A lack of confirmation by local magnetic probe methods has raised the possibility that the magnetic order fluctuates slowly enough to appear static on the time scale of neutron scattering, but too fast to affect μ SR or nuclear magnetic resonance signals. The IUC magnetic order has been linked to a theoretical model for the cuprates, which predicts a long-range ordered phase of electron-current loop order that terminates at a quantum crictical point (QCP). Our study suggests that lowering the temperature to T ˜25 mK and moving far below the purported QCP does not cause enough of a slowing down of fluctuations for the IUC magnetic order to become detectable on the time scale of μ SR . Our measurements place narrow limits on the fluctuation rate of this unidentified magnetic order.

  6. Results and analysis of saltstone cores taken from saltstone disposal unit cell 2A

    Energy Technology Data Exchange (ETDEWEB)

    Reigel, M. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hill, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    As part of an ongoing Performance Assessment (PA) Maintenance Plan, Savannah River Remediation (SRR) has developed a sampling and analyses strategy to facilitate the comparison of field-emplaced samples (i.e., saltstone placed and cured in a Saltstone Disposal Unit (SDU)) with samples prepared and cured in the laboratory. The primary objectives of the Sampling and Analyses Plan (SAP) are; (1) to demonstrate a correlation between the measured properties of laboratory-prepared, simulant samples (termed Sample Set 3), and the field-emplaced saltstone samples (termed Sample Set 9), and (2) to validate property values assumed for the Saltstone Disposal Facility (SDF) PA modeling. The analysis and property data for Sample Set 9 (i.e. six core samples extracted from SDU Cell 2A (SDU2A)) are documented in this report, and where applicable, the results are compared to the results for Sample Set 3. Relevant properties to demonstrate the aforementioned objectives include bulk density, porosity, saturated hydraulic conductivity (SHC), and radionuclide leaching behavior.

  7. The modeling of a standalone solid-oxide fuel cell auxiliary power unit

    Science.gov (United States)

    Lu, N.; Li, Q.; Sun, X.; Khaleel, M. A.

    In this research, a Simulink model of a standalone vehicular solid-oxide fuel cell (SOFC) auxiliary power unit (APU) is developed. The SOFC APU model consists of three major components: a controller model; a power electronics system model; and an SOFC plant model, including an SOFC stack module, two heat exchanger modules, and a combustor module. This paper discusses the development of the nonlinear dynamic models for the SOFC stacks, the heat exchangers and the combustors. When coupling with a controller model and a power electronic circuit model, the developed SOFC plant model is able to model the thermal dynamics and the electrochemical dynamics inside the SOFC APU components, as well as the transient responses to the electric loading changes. It has been shown that having such a model for the SOFC APU will help design engineers to adjust design parameters to optimize the performance. The modeling results of the SOFC APU heat-up stage and the output voltage response to a sudden load change are presented in this paper. The fuel flow regulation based on fuel utilization is also briefly discussed.

  8. Fungal spore concentrations in two haematopoietic stem cell transplantation (HSCT) units containing distinct air control systems.

    Science.gov (United States)

    Brun, C P; Miron, D; Silla, L M R; Pasqualotto, A C

    2013-04-01

    Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

  9. High-temperature superconductivity in one-unit-cell FeSe films

    Science.gov (United States)

    Wang, Ziqiao; Liu, Chaofei; Liu, Yi; Wang, Jian

    2017-04-01

    Since the dramatic enhancement of the superconducting transition temperature (T c) was reported in a one-unit-cell FeSe film grown on a SrTiO3 substrate (1-UC FeSe/STO) by molecular beam epitaxy (MBE), related research on this system has become a new frontier in condensed matter physics. In this paper, we present a brief review on this rapidly developing field, mainly focusing on the superconducting properties of 1-UC FeSe/STO. Experimental evidence for high-temperature superconductivity in 1-UC FeSe/STO, including direct evidence revealed by transport and diamagnetic measurements, as well as other evidence from scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), are overviewed. The potential mechanisms of the enhanced superconductivity are also discussed. There are accumulating arguments to suggest that the strengthened Cooper pairing in 1-UC FeSe/STO originates from the interface effects, specifically the charge transfer and coupling to phonon modes in the TiO2 plane. The study of superconductivity in 1-UC FeSe/STO not only sheds new light on the mechanism of high-temperature superconductors with layered structures, but also provides an insight into the exploration of new superconductors by interface engineering.

  10. Giant repeater F-wave in patients with anterior horn cell disorders. Role of motor unit size.

    Science.gov (United States)

    Ibrahim, I K; el-Abd, M A

    1997-01-01

    Conventional F-wave responses as well as single motor unit F-wave responses together with the volitionally recruited motor unit action potentials (MUAP) were studied in hand and feet muscles of 10 healthy subjects and 32 patients with anterior horn cell disorders. The amplitude of the largest F-wave (Fl) was significantly greater in the affected patients compared with healthy subjects. Giant repeater F-wave responses "up to 4 mV" were recorded in muscles having volitionally recruited giant MUAPs. Although, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs was significantly decreased in amyotrophic lateral sclerosis patients, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs that gave motor unit F-wave response was significantly increased compared with healthy subjects. The responding orthodromic MUAP gave identical motor unit F-wave response, even for complex polyphasic units. Enhanced monosynaptic (H-) reflex, proximal axon reflex (A-wave), and repetitive muscle response as possible explanations for the giant F-wave responses could be discounted. The electrophysiologic behavior of the giant late responses described here fits well with the criteria of F-waves modulated by newly formed distal (and or proximal) axonal branching.

  11. Tuning oxygen vacancy photoluminescence in monoclinic Y2WO6 by selectively occupying yttrium sites using lanthanum

    Science.gov (United States)

    Ding, Bangfu; Han, Chao; Zheng, Lirong; Zhang, Junying; Wang, Rongming; Tang, Zilong

    2015-01-01

    The effect of isovalent lanthanum (La) doping on the monoclinic Y2WO6 photoluminescence was studied. Introducing the non-activated La3+ into Y2WO6 brings new excitation bands from violet to visible regions and strong near-infrared emission, while the bands position and intensity depend on the doping concentration. It is interesting to find that doping La3+ into Y2WO6 promotes the oxygen vacancy formation according to the first-principle calculation, Raman spectrum, and synchrotron radiation analysis. Through the Rietveld refinement and X-ray photoelectron spectroscopy results, La3+ is found to mainly occupy the Y2 (2f) site in low-concentration doped samples. With increasing doping concentration, the La3+ occupation number at the Y3 (4g) site increases faster than those at the Y1 (2e) and Y2 (2f) sites. When La3+ occupies different Y sites, the localized energy states caused by the oxygen vacancy pair change their position in the forbidden band, inducing the variation of the excitation and emission bands. This research proposes a feasible method to tune the oxygen vacancy emission, eliminating the challenge of precisely controlling the calcination atmosphere. PMID:25821078

  12. Surface, optical characteristics and photocatalytic ability of Scheelite-type monoclinic Bi3FeMo2O12 nanoparticles

    Science.gov (United States)

    Nie, Xinming; Wulayin, Wumitijiang; Song, Tingting; Wu, Minxiao; Qiao, Xuebin

    2016-11-01

    Bi3FeMo2O12 nanoparticles with the Scheelite-type monoclinic structure were prepared by the Pechini synthesis. The Bi3FeMo2O12 nanoparticle has a size of about 50 nm. The phase formation and structural characteristic were studied by X-ray diffraction (XRD) patterns and Rietveld refinements. The Scheelite framework is characterized by a superstructure constructed by the ordered arrangement of Fe/Mo tetrahedral on the B sites. The surface characteristics of Bi3FeMo2O12 nanoparticles were studied by the measurements such as the scanning electron microscope (SEM), the transmission electron microscopy (TEM), and the N2-adsorption-desorption isotherm. Bi3FeMo2O12 nanoparticles present an efficient optical absorption in a wide wavelength region from UV to 540 nm. The band gap energy was decided to be 2.3 eV and characterized by a direct allowed electronic optical transition. The photocatalytic activity of Bi3FeMo2O12 nanoparticles was confirmed by the photodegradation of the rhodamine B (RhB) dye solution. The experiments indicate that the Scheelite-type molybdate could be a potential candidate of a visible-light-driven photocatalyst.

  13. Monoclinic Hydroxyapatite Nanoplates Hybrid Composite with Improved Compressive Strength, and Porosity for Bone Defect Repair: Biomimetic Synthesis and Characterization.

    Science.gov (United States)

    Xue, Bo; Farghaly, Ahmed A; Guo, Zhenzhao; Zhao, Pengg; Li, Hong; Zhou, Changren; Li, Lihua

    2016-03-01

    Calcium phosphate cement (CPC) has been used for bone restoration despite its intrinsic fragile property. In order to enhance the CPC mechanical properties, biopolymers were introduced as filler to prepare CPC based cements. Chitosan/tetracalcium phosphate (TTCP)/dicalcium phosphate anhydrous (DCPA) based cement for bone repair has been prepared in the study. Solidification of the prepared cement was carried out in a simulate body fluid at 37 degrees C. The introduction of chitosan improved the mechanical performance of the as-prepared CPC hybrid nanocomposite. FTIR, SEM, TEM, HRTEM, XRD, and SAED were used to characterize the CPC nanocomposite. Data simulations have been performed to assist in determining the crystalline phase/s in the CPC hybrid nanocomposite. Based on the SAED, HRTEM measurements and data simulations, a monoclinic phase of hydroxyapatite (HAP) with a plate-like structure was obtained in the CPC system, which is believed to be responsible for the observed enhancement in CPC mechanical properties. The obtained composite has a biocompatibility comparable to that of commercial sample.

  14. Pure monoclinic La(1-x)Eu(x)PO₄ micro-/nano-structures: fast synthesis, shape evolution and optical properties.

    Science.gov (United States)

    Chen, Huanhuan; Ni, Yonghong; Ma, Xiang; Hong, Jianming

    2014-08-15

    Rare-earth-doped LaPO4 crystals have been attracting considerable interest. In this work, we reported the fast syntheses of LaPO4 and Eu-doped LaPO4 crystals via a simple oil-bath route, employing La(NO3)3 and KH2PO4 as the original reactants, Eu2O3 as the dopant. The reaction was carried out in ethylene glycol system at 120°C for 30 min without any assistance of surfactants or templates. X-ray powder diffraction analyses showed that pure monoclinic LaPO4 form was obtained in the system without Eu(3+) ions, and the above phase was not changed after integrating Eu(3+) ions into LaPO4 matrix. However, electron microscopy observations discovered that the integration of Eu(3+) ions into LaPO4 matrix obviously changed the morphology and size of the final La(1-x)Eu(x)PO4 crystals. With the increase in Eu(3+) amount from 0 to 0.35, the shape of the final product varied from homogeneous egg-like nanospheroids, to irregular grains with microscales, and to homogeneous microspheroids. Also, the Eu(3+) ion content in La(1-x)Eu(x)PO4 markedly affected the photoluminescence properties of the final product. When x=0.2, the product exhibited the strongest PL emission.

  15. Synthesis of monoclinic structured BiVO4 spindly microtubes in deep eutectic solvent and their application for dye degradation.

    Science.gov (United States)

    Liu, Wei; Yu, Yaqin; Cao, Lixin; Su, Ge; Liu, Xiaoyun; Zhang, Lan; Wang, Yonggang

    2010-09-15

    Monoclinic structured spindly bismuth vanadate microtubes were fabricated on a large scale by a simple ionothermal treatment in the environment-friendly green solvent of urea/choline chloride. The as-prepared samples were characterized by XRD, SEM, TEM, IR and their photocatalytic activity was evaluated by photocatalytic decolorization of rhodamine B aqueous solution under visible-light irradiation. As-obtained BiVO(4) microtubes exhibit the spindly shape with a side length of ca. 800 nm and a wall thickness of ca. 100 nm. The opening of these microtubes presents a saw-toothed structure, which is seldom in other tube-shaped materials. The formation mechanism of the spindly microtubes is ascribed to the complex cooperation of the reaction-crystallization process controlled by BiOCl and the nucleation-growth process of nanosheets induced by solvent molecules attached on the surface of microtubes. Such spindly microtubes exhibit much higher visible-light photocatalytic activity than that of bulk BiVO(4) prepared by solid-state reaction, possibly resulting from their large surface area and improved crystallinity.

  16. Ultrasound assisted synthesis of monoclinic structured spindle BiVO4 particles with hollow structure and its photocatalytic property.

    Science.gov (United States)

    Liu, Wei; Cao, Lixin; Su, Ge; Liu, Haisong; Wang, Xiangfei; Zhang, Lan

    2010-04-01

    Bismuth vanadate (BiVO(4)) spindle particles with monoclinic scheelite structure have been successfully synthesized via a facile sonochemical method. The as-prepared BiVO(4) photocatalyst exhibited a hollow interior structure constructed from the self-assembly of cone shape primary nanocrystals. A possible oriented attachment growth mechanism has been proposed based on the results of time-dependent experiments, which indicates the formation of spindle particles is mainly attributed to the phase transformation procedure induced by ultrasound irradiation. A series of morphology evolutions of BiVO(4) from compact microspheres, to hollow microspheres, and then to spindle particles have been arrested in the process of sonochemical treatment. Optical absorption experiments revealed the BiVO(4) spindle had strong absorption in the visible light region. A much higher photocatalytic activity of these spindle particles was found in comparison with the SSR-BiVO(4) material for degradation of rhodamine-B under visible light irradiation, which may be ascribed to its special single-crystalline nanostructure.

  17. Template-Free Synthesis of Monoclinic BiVO4 with Porous Structure and Its High Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Pengyu Dong

    2016-08-01

    Full Text Available Monoclinic BiVO4 photocatalysts with porous structures were synthesized by a two-step approach without assistance of any templates. The as-prepared samples were characterized by X-ray diffraction pattern (XRD, scanning electron microscopy (SEM, Brunauer–Emmett–Teller (BET, ultraviolet–visible (UV–vis diffuse reflectance spectroscopy (DRS, photocurrent responses, and electrochemical impedance spectra (EIS. It is found that the as-prepared BiVO4 samples had a porous structure with aperture diameter of 50–300 nm. Moreover, the BET specific surface area of the porous BiVO4-200 °C sample reaches up to 5.69 m2/g, which is much higher than that of the sample of BiVO4 particles without porous structure. Furthermore, a possible formation mechanism of BiVO4 with porous structure was proposed. With methylene blue (MB as a model compound, the photocatalytic oxidation of organic contaminants in aqueous solution was investigated under visible light irradiation. It is found that the porous BiVO4-200 °C sample exhibits the best photocatalytic activity, and the photocatalytic rate constant is about three times of that of the sample of BiVO4 particles without porous structure. In addition, the photocurrent responses and electrochemical impedance spectra strongly support this conclusion.

  18. Photocatalytic degradation and removal mechanism of ibuprofen via monoclinic BiVO4 under simulated solar light.

    Science.gov (United States)

    Li, Fuhua; Kang, Yapu; Chen, Min; Liu, Guoguang; Lv, Wenying; Yao, Kun; Chen, Ping; Huang, Haoping

    2016-05-01

    Characterized as by X-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectra techniques, BiVO4 photocatalyst was hydrothermally synthesized. The photocatalytic degradation mechanisms of ibuprofen (IBP) were evaluated in aqueous media via BiVO4. Results demonstrated that the prepared photocatalyst corresponded to phase-pure monoclinic scheelite BiVO4. The synthesized BiVO4 showed superior photocatalytic properties under the irradiation of visible-light. The photocatalytic degradation rate of IBP decreased with an increase in the initial IBP concentration. The degradation process followed first-order kinetics model. At an IBP concentration of 10 mg L(-1), while a BiVO4 concentration of 5.0 g L(-1) with pH value of 4.5, the rate of IBP degradation was obtained as 90% after 25 min. The photocatalytic degradation of IBP was primarily accomplished via the generation of superoxide radical (O2(•-)) and hydroxyl radicals ((•)OH). During the process of degradation, part of the (•)OH was converted from the O2(•-). The direct oxidation of holes (h(+)) made a minimal contribution to the degradation of IBP.

  19. Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties

    NARCIS (Netherlands)

    Ahmadi, S.M.; Yavari, S.A.; Wauthle, R.; Pouran, B.; Schrooten, J.; Weinans, H.; Zadpoor, A.A.

    2015-01-01

    It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primari

  20. Theoretical characterization and design of small molecule donor material containing naphthodithiophene central unit for efficient organic solar cells.

    Science.gov (United States)

    Duan, Yu-Ai; Geng, Yun; Li, Hai-Bin; Jin, Jun-Ling; Wu, Yong; Su, Zhong-Min

    2013-07-15

    To seek for high-performance small molecule donor materials used in heterojunction solar cell, six acceptor-donor-acceptor small molecules based on naphtho[2,3-b:6,7-b']dithiophene (NDT) units with different acceptor units were designed and characterized using density functional theory and time-dependent density functional theory. Their geometries, electronic structures, photophysical, and charge transport properties have been scrutinized comparing with the reported donor material NDT(TDPP)2 (TDPP  =  thiophene-capped diketopyrrolopyrrole). The open circuit voltage (V(oc)), energetic driving force(ΔE(L-L)), and exciton binding energy (E(b)) were also provided to give an elementary understanding on their cell performance. The results reveal that the frontier molecular orbitals of 3-7 match well with the acceptor material PC61 BM, and compounds 3-5 were found to exhibit the comparable performances to 1 and show promising potential in organic solar cells. In particular, comparing with 1, system 7 with naphthobisthiadiazole acceptor unit displays broader absorption spectrum, higher V(oc), lower E(b), and similar carrier mobility. An in-depth insight into the nature of the involved excited states based on transition density matrix and charge density difference indicates that all S1 states are mainly intramolecular charge transfer states with the charge transfer from central NDT unit to bilateral acceptor units, and also imply that the exciton of 7 can be dissociated easily due to its large extent of the charge transfer. In a word, 7 maybe superior to 1 and may act as a promising donor candidate for organic solar cell. Copyright © 2013 Wiley Periodicals, Inc.

  1. Fermi surface properties of paramagnetic NpCd{sub 11} with a large unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Homma, Yoshiya; Aoki, Dai; Shiokawa, Yoshinobu [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Yoshinori; Sakai, Hironori; Ikeda, Shugo; Yamamoto, Etsuji; Nakamura, Akio; Onuki, Yoshichika [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Settai, Rikio [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Takeuchi, Tetsuya [Cryogenic Center, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Yamagami, Hiroshi, E-mail: yhomma@imr.tohoku.ac.jp [Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555 (Japan)

    2010-03-15

    We succeeded in growing a high-quality single crystal of NpCd{sub 11} with the cubic BaHg{sub 11}-type structure by the Cd-self flux method. The lattice parameter of a = 9.2968(2) A and crystallographic positions of the atoms were determined by x-ray single-crystal structure analysis. From the results of the magnetic susceptibility and specific heat experiments, this compound is found to be a 5f-localized paramagnet with the singlet ground state in the crystalline electric field (CEF) scheme. Fermi surface properties were measured using the de Haas-van Alphen (dHvA) technique. Long-period oscillations were observed in the dHvA frequency range of 9.1 x 10{sup 5} to 1.9 x 10{sup 7} Oe, indicating small cross-sectional areas of Fermi surfaces, which is consistent with a small Brillouin zone based on a large unit cell. From the results of dHvA and magnetoresistance experiments, the Fermi surface of NpCd{sub 11} is found to consist of many kinds of closed Fermi surfaces and a multiply-connected-like Fermi surface, although the result of energy band calculations based on the 5f-localized Np{sup 3+}(5f{sup 4}) configuration reveals the existence of only closed Fermi surfaces. The corresponding cyclotron effective mass is small, ranging from 0.1 to 0.7 m{sub 0}, which is consistent with a small electronic specific heat coefficient {gamma} {approx_equal} 10mJ/K{sup 2{center_dot}}mol, revealing no hybridization between the 5f electrons and conduction electrons.

  2. In vitro fertilization and stem cell harvesting from human embryos: the law and practice in the United States.

    Science.gov (United States)

    Hook, C Christopher

    2010-07-01

    The challenges before science and medicine are these: science must explore the natural world as thoroughly as possible, while still honoring, protecting, serving and preserving the subject of its investigations, and the human beings for whom it is a tool; medicine must confront disease and disability as effectively as possible, while also honoring, protecting, and preserving those beings for whom it serves - all of those beings, not just some, or even most, at the potential expense of others. These goals are challenged by embryo-destructive human embryonic stem cell research. The human embryo is a human being as clearly defined by embryology, and as such should be protected by the codes governing human subject research. However, because of the "potential" benefits offered by pluripotent stem cells, coupled with abortion politics and a very poorly regulated infertility industry, United States governmental advisory commissions and the scientific, medical, and political communities have attempted to define away the humanity of the human embryo, with a few notable exceptions. Because infertility treatments in the United States are poorly regulated, there are large numbers of supernumerary embryos in cryopreservation. However, only a tiny portion of these will ever be potentially available for research, and thus are not a realistic source of the cells necessary to provide treatments to the millions who might benefit from proposed stem cell based therapies. Cloning will not be the answer either, given the millions of women who must be exploited to provide sufficient numbers of eggs to generate the cloned cell lines. Moreover, the disposition decisions parents must make for their extra embryos are often agonizing, and not uncommonly change. The use of supernumerary embryos as a source for human embryonic stem cells is unethical, will never be a sufficient source for the medical treatments expected from stem cell research, and is often a source of great distress for the

  3. In vitro fertilization and stem cell harvesting from human embryos: the law and practice in the United States

    Directory of Open Access Journals (Sweden)

    C. Christopher Hook

    2010-07-01

    Full Text Available The challenges before science and medicine are these: science must explore the natural world as thoroughly as possible, while still honoring, protecting, serving and preserving the subject of its investigations, and the human beings for whom it is a tool; medicine must confront disease and disability as effectively as possible, while also honoring, protecting, and preserving those beings for whom it serves – all of those beings, not just some, or even most, at the potential expense of others. These goals are challenged by embryo-destructive human embryonic stem cell research. The human embryo is a human being as clearly defined by embryology, and as such should be protected by the codes governing human subject research. However, because of the “potential” benefits offered by pluripotent stem cells, coupled with abortion politics and a very poorly regulated infertility industry, United States governmental advisory commissions and the scientific, medical, and political communities have attempted to define away the humanity of the human embryo, witha few notable exceptions. Because infertility treatments in the United States are poorly regulated, there are large numbersof supernumerary embryos in cryopreservation. However, only a tiny portion of these will ever be potentially available for research, and thus are not a realistic source of the cells necessary to provide treatments to the millions who might benefit from proposed stem cell based therapies. Cloning willnot be the answer either, given the millions of women who must be exploited to provide sufficient numbers of eggs to generate the cloned cell lines. Moreover, the disposition decisions parents must make for their extra embryos are often agonizing, and not uncommonly change.The use of supernumerary embryos as a source for human embryonic stem cells is unethical, will never be a sufficient source for the medical treatments expected from stem cell research, and is often a source of

  4. Frequency and Risk Factors Associated with Cord Graft Failure after Transplant with Single-Unit Umbilical Cord Cells Supplemented by Haploidentical Cells with Reduced-Intensity Conditioning.

    Science.gov (United States)

    Tsai, Stephanie B; Liu, Hongtao; Shore, Tsiporah; Fan, Yun; Bishop, Michael; Cushing, Melissa M; Gergis, Usama; Godley, Lucy; Kline, Justin; Larson, Richard A; Martinez, Guadalupe; Mayer, Sebastian; Odenike, Olatoyosi; Stock, Wendy; Wickrema, Amittha; van Besien, Koen; Artz, Andrew S

    2016-06-01

    Delayed engraftment and cord graft failure (CGF) are serious complications after unrelated cord blood (UCB) hematopoietic stem cell transplantation (HSCT), particularly when using low-cell-dose UCB units. The haplo-cord HSCT approach allows the use of a lower dose single UCB unit by co-infusion of a CD34(+) selected haploidentical graft, which provides early transient engraftment while awaiting durable UCB engraftment. We describe the frequency, complications, and risk factors of CGF after reduced-intensity conditioning haplo-cord HSCT. Among 107 patients who underwent haplo-cord HSCT, 94 were assessable for CGF, defined as risk of CGF. We conclude that assessing chimerism at day 30 may foretell impending CGF, and avoidance of high haploidentical cell doses may reduce risk of CGF after haplo-cord HSCT. However, long-term survival is possible after CGF because of predominant haploidentical or mixed chimerism and hematopoietic function.

  5. Development of integrated DMFC and PEM fuel cell units. Final report; Udvikling af integrerede DMFC og PEM braendselscelle enheder. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Odgaard, M. (IRD Fuel Cell Technology, Svendborg (DK))

    2007-06-15

    The 36-month long project 'Development of integrated DMFC and PEM fuel cell units' has been completed. The project goal was to develop a completely new MEA concept for integrated PEM and DMFC unit cells with enhanced power density and in this way obtain a price reduction. The integrated unit cell consists of a MEA, a gas diffusion layer with flow fields completed with bipolar plates and seals. The main focus of the present project was to: 1) Develop new catalyst materials fabricated by the use of FSD (flame spray deposition method). 2) Optimisation of the state-of-the-art MEA materials and electrode structure. 3) Implementation of a model to account for the CO poisoning of PEM fuel cells. Results and progress obtained in the project established that the individual unit cell components were able to meet and follow the road map of LT-PEM FC regarding electrode catalyst loading and fulfilled the targets for Year 2006. The project has resulted in some important successes. The highlights are as follows: The project has resulted in some important successes. The highlights are as follows: 1) MEA structure knowledge acquired in the project provide a sound basis for further progress. 2) A novel method for the synthesis of electrode by using flame spray synthesis was explored. 3) Electrochemical and catalytic behaviours of catalysts activity for CH{sub 3}OH explored. 4) Implementation of a sub model to account for the CO poisoning of PEM FC has been developed. 5) Numerical study of the flow distribution in FC manifolds was developed and completed with experimental data. 6) The electrode catalyst loading targets for year 2006 achieved. 7) The DMFC MEA performance has been improved by 35%. 8) Optimisation of the MEAs fabrication process has been successfully developed. 9) A new simple flow field design has been designed. 10) A procedure for integrated seals has been developed (au)

  6. THE FEATURES OF CONNEXINS EXPRESSION IN THE CELLS OF NEUROVASCLAR UNIT IN NORMAL CONDITIONS AND HYPOXIA IN VITRO

    Directory of Open Access Journals (Sweden)

    A. V. Morgun

    2014-01-01

    Full Text Available The aim of this research was to assess a role of connexin 43 (Cx43 and associated molecule CD38 in the regulation of cell-cell interactions in the neurovascular unit (NVU in vitro in physiological conditions and in hypoxia.Materials and methods. The study was done using the original neurovascular unit model in vitro. The NVU consisted of three cell types: neurons, astrocytes, and cerebral endothelial cells derived from rats. Hypoxia was induced by incubating cells with sodium iodoacetate for 30 min at37 °C in standard culture conditions.Results. We investigated the role of connexin 43 in the regulation of cell interactions within the NVU in normal and hypoxic injury in vitro. We found that astrocytes were characterized by high levels of expression of Cx43 and low level of CD38 expression, neurons demonstrated high levels of CD38 and low levels of Cx43. In hypoxic conditions, the expression of Cx43 and CD38 in astrocytes markedly increased while CD38 expression in neurons decreased, however no changes were found in endothelial cells. Suppression of Cx43 activity resulted in down-regulation of CD38 in NVU cells, both in physiological conditions and at chemical hypoxia.Conclusion. Thus, the Cx-regulated intercellular NAD+-dependent communication and secretory phenotype of astroglial cells that are the part of the blood-brain barrier is markedly changed in hypoxia.

  7. Tool for Generation of MAC/GMC Representative Unit Cell for CMC/PMC Analysis

    Science.gov (United States)

    Murthy, Pappu L. N.; Pineda, Evan J.

    2016-01-01

    This document describes a recently developed analysis tool that enhances the resident capabilities of the Micromechanics Analysis Code with the Generalized Method of Cells (MAC/GMC) 4.0. This tool is especially useful in analyzing ceramic matrix composites (CMCs), where higher fidelity with improved accuracy of local response is needed. The tool, however, can be used for analyzing polymer matrix composites (PMCs) as well. MAC/GMC 4.0 is a composite material and laminate analysis software developed at NASA Glenn Research Center. The software package has been built around the concept of the generalized method of cells (GMC). The computer code is developed with a user friendly framework, along with a library of local inelastic, damage, and failure models. Further, application of simulated thermomechanical loading, generation of output results, and selection of architectures to represent the composite material have been automated to increase the user friendliness, as well as to make it more robust in terms of input preparation and code execution. Finally, classical lamination theory has been implemented within the software, wherein GMC is used to model the composite material response of each ply. Thus, the full range of GMC composite material capabilities is available for analysis of arbitrary laminate configurations as well. The primary focus of the current effort is to provide a graphical user interface (GUI) capability that generates a number of different user-defined repeating unit cells (RUCs). In addition, the code has provisions for generation of a MAC/GMC-compatible input text file that can be merged with any MAC/GMC input file tailored to analyze composite materials. Although the primary intention was to address the three different constituents and phases that are usually present in CMCs-namely, fibers, matrix, and interphase-it can be easily modified to address two-phase polymer matrix composite (PMC) materials where an interphase is absent. Currently, the

  8. Monoclinic BiVO{sub 4} micro-/nanostructures: Microwave and ultrasonic wave combined synthesis and their visible-light photocatalytic activities

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yafang; Li, Guangfang; Yang, Xiaohui; Yang, Hao; Lu, Zhong [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Avenue, Wuhan 430073 (China); Chen, Rong, E-mail: rchenhku@hotmail.com [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Avenue, Wuhan 430073 (China); Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Lumo Road, Wuhan 430074 (China)

    2013-02-25

    Graphical abstract: Monoclinic BiVO{sub 4} with different sizes and morphologies were synthesized by a facile microwave and ultrasonic wave combined technique for the first time and exhibited different optical properties and visible-light-driven photocatalytic efficiency. Highlights: Black-Right-Pointing-Pointer BiVO{sub 4} nanostructures were prepared by microwave and ultrasonic wave combined method. Black-Right-Pointing-Pointer BiVO{sub 4} nanostructures could be modulated by varying the solvent and pH value. Black-Right-Pointing-Pointer Different BiVO{sub 4} nanostructures exhibited different photocatalytic activities. Black-Right-Pointing-Pointer The photocatalytic performance was influenced by the band gap, phase and size. - Abstract: Monoclinic bismuth vanadate (m-BiVO{sub 4}) micro-/nanostructures with different sizes and morphologies were successfully prepared via a facile and rapid microwave and ultrasonic wave combined technique. The obtained BiVO{sub 4} products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and UV-vis diffuse reflection spectroscopy (DRS). It was found that the solvent and pH value had a significant influence on morphology, size and crystalline structure of the product. Nut-like, potato-like and broccoli-like monoclinic BiVO{sub 4} were fabricated in different solvents. The crystal phase could be modulated by varying the pH value of reaction system. The photocatalytic activities of the products were also evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. The result revealed that the photocatalytic activities of BiVO{sub 4} nanostructures were closely related to the crystalline phase, band gap and particle size. Monoclinic BiVO{sub 4} nanoparticles with small crystal size and large band gap exhibited remarkable photocatalytic performance.

  9. Propagation of SH waves in an regular non homogeneous monoclinic crustal layer lying over a non-homogeneous semi-infinite medium

    Directory of Open Access Journals (Sweden)

    Sethi M.

    2016-05-01

    Full Text Available The present paper discusses the dispersion equation for SH waves in a non-homogeneous monoclinic layer over a semi infinite isotropic medium. The wave velocity equation has been obtained. In the isotropic case, when non-homogeneity is absent, the dispersion equation reduces to the standard SH wave equation. The dispersion curves are depicted by means of graphs for different values of non-homogeneity parameters for the layer and semi-infinite medium.

  10. Indium phosphide solar cell research in the United States: Comparison with non-photovoltaic sources

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

    1989-01-01

    Highlights of the InP solar cell research program are presented. Homojunction cells with efficiencies approaching 19 percent are demonstrated, while 17 percent is achieved for ITO/InP cells. The superior radiation resistance of the two latter cell configurations over both Si and GaAs cells has been shown. InP cells aboard the LIPS3 satellite show no degradation after more than a year in orbit. Computed array specific powers are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

  11. Tunable Multifunctional Thermal Metamaterials: Manipulation of Local Heat Flux via Assembly of Unit-Cell Thermal Shifters.

    Science.gov (United States)

    Park, Gwanwoo; Kang, Sunggu; Lee, Howon; Choi, Wonjoon

    2017-01-20

    Thermal metamaterials, designed by transformation thermodynamics are artificial structures that can actively control heat flux at a continuum scale. However, fabrication of them is very challenging because it requires a continuous change of thermal properties in materials, for one specific function. Herein, we introduce tunable thermal metamaterials that use the assembly of unit-cell thermal shifters for a remarkable enhancement in multifunctionality as well as manufacturability. Similar to the digitization of a two-dimensional image, designed thermal metamaterials by transformation thermodynamics are disassembled as unit-cells thermal shifters in tiny areas, representing discretized heat flux lines in local spots. The programmed-reassembly of thermal shifters inspired by LEGO enable the four significant functions of thermal metamaterials-shield, concentrator, diffuser, and rotator-in both simulation and experimental verification using finite element method and fabricated structures made from copper and PDMS. This work paves the way for overcoming the structural and functional limitations of thermal metamaterials.

  12. Surface and Interface Properties of 10–12 Unit Cells Thick Sputter Deposited Epitaxial CeO2 Films

    Directory of Open Access Journals (Sweden)

    L. V. Saraf

    2008-01-01

    Full Text Available Ultrathin and continuous epitaxial films with relaxed lattice strain can potentially maintain more of its bulk physical and chemical properties and are useful as buffer layers. We study surface, interface, and microstructural properties of ultrathin (∼10–12 unit cells thick epitaxial ceria films grown on single crystal YSZ substrates. The out-of -plane and in-plane lattice parameters indicate relaxation in the continuous film due to misfit dislocations seen by high-resolution transmission electron microscopy (HRTEM and substrate roughness of ∼1-2 unit cells, confirmed by atomic force microscopy and HRTEM. A combination of secondary sputtering, lattice mismatch, substrate roughness, and surface reduction creating secondary phase was likely the cause of surface roughness which should be reduced to a minimum level for effective use of it as buffer layers.

  13. Tunable Multifunctional Thermal Metamaterials: Manipulation of Local Heat Flux via Assembly of Unit-Cell Thermal Shifters

    Science.gov (United States)

    Park, Gwanwoo; Kang, Sunggu; Lee, Howon; Choi, Wonjoon

    2017-01-01

    Thermal metamaterials, designed by transformation thermodynamics are artificial structures that can actively control heat flux at a continuum scale. However, fabrication of them is very challenging because it requires a continuous change of thermal properties in materials, for one specific function. Herein, we introduce tunable thermal metamaterials that use the assembly of unit-cell thermal shifters for a remarkable enhancement in multifunctionality as well as manufacturability. Similar to the digitization of a two-dimensional image, designed thermal metamaterials by transformation thermodynamics are disassembled as unit-cells thermal shifters in tiny areas, representing discretized heat flux lines in local spots. The programmed-reassembly of thermal shifters inspired by LEGO enable the four significant functions of thermal metamaterials—shield, concentrator, diffuser, and rotator—in both simulation and experimental verification using finite element method and fabricated structures made from copper and PDMS. This work paves the way for overcoming the structural and functional limitations of thermal metamaterials. PMID:28106156

  14. Compact Circularly Polarized Patch Antenna Using a Composite Right/Left-Handed Transmission Line Unit-Cell

    Directory of Open Access Journals (Sweden)

    L. Geng

    2013-04-01

    Full Text Available A compact circularly polarized (CP patch antenna using a composite right/left-handed (CRLH transmission line (TL unit-cell is proposed. The CRLH TL unit-cell includes a complementary split ring resonator (CSRR for shunt inductance and a gap loaded with a circular-shaped slot for series capacitance. The CSRR can decrease the TM10 mode resonance frequency, thus reducing the electrical size of the proposed antenna. In addition, the asymmetry of the CSRR brings about the TM01 mode, which can be combined with the TM10 mode by changing the slot radius. The combination of these two orthogonal modes with 90° phase shift makes the proposed antenna provide a CP property. The experimental results show that the proposed antenna has a wider axial ratio bandwidth and a smaller electrical size than the reported CP antennas. Moreover, the proposed antenna is designed without impedance transformer, 90° phase shift, dual feed and ground via.

  15. Optical, structural and fluorescence properties of nanocrystalline cubic or monoclinic Eu:Lu{sub 2}O{sub 3} films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Martinet, C. [Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-Universite Lyon1, 10, rue Andre-Marie Ampere, 69622 Villeurbanne Cedex (France)]. E-mail: martinet@pcml.univ-lyon1.fr; Pillonnet, A. [Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-Universite Lyon1, 10, rue Andre-Marie Ampere, 69622 Villeurbanne Cedex (France); Lancok, J. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Prague (Czech Republic); Garapon, C. [Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-Universite Lyon1, 10, rue Andre-Marie Ampere, 69622 Villeurbanne Cedex (France)

    2007-10-15

    Eu{sup 3+}-doped lutetium oxide (Eu:Lu{sub 2}O{sub 3}) nanocrystalline films were grown on fused-silica substrates by pulsed laser deposition. Depending on deposition conditions (oxygen pressure, temperature and laser energy), the structure of the films changed from amorphous to crystalline and the cubic or monoclinic phases were obtained with varying preferential orientation and crystallite size. The monoclinic phase could be prepared for the first time at temperatures as low as 240 deg. C and in a narrow range of parameters. Although this phase has been previously reported for powder samples, it occurs only for high pressures and high temperatures preparation conditions. The refractive indices were measured by m-lines spectroscopy for both crystalline phases and their dispersion curve fitted by the Sellmeier expression. The specific Eu{sup 3+} fluorescence properties of the different phases, monoclinic and cubic, were registered and show modifications due to the disorder induced by the nanometric size of the crystallites, emphasised in particular by quasi-selective excitation in the charge transfer band.

  16. Monoclinic 122-Type BaIr2Ge2 with a Channel Framework: A Structural Connection between Clathrate and Layered Compounds

    Directory of Open Access Journals (Sweden)

    Xin Gui

    2017-07-01

    Full Text Available A new 122-type phase, monoclinic BaIr2Ge2 is successfully synthesized by arc melting; X-ray diffraction and scanning electron microscopy are used to purify the phase and determine its crystal structure. BaIr2Ge2 adopts a clathrate-like channel framework structure of the monoclinic BaRh2Si2-type, with space group P21/c. Structural comparisons of clathrate, ThCr2Si2, CaBe2Ge2, and BaRh2Si2 structure types indicate that BaIr2Ge2 can be considered as an intermediate between clathrate and layered compounds. Magnetic measurements show it to be diamagnetic and non-superconducting down to 1.8 K. Different from many layered or clathrate compounds, monoclinic BaIr2Ge2 displays a metallic resistivity. Electronic structure calculations performed for BaIr2Ge2 support its observed structural stability and physical properties.

  17. Interfacing of science, medicine and law: The stem cell patent controversy in the United States and the European Union

    Directory of Open Access Journals (Sweden)

    Sonya eDavey

    2015-11-01

    Full Text Available The patent eligibility of stem cells – particularly those derived from human embryos – has long been under debate in both the scientific and legal communities. On the basis of moral grounds, the European Patent Office (EPO has refrained from granting patents for stem cells obtained through the destruction of human embryos. On the contrary, the United States Patent and Trademark Office (USPTO has historically granted patents regarding the isolation and use of human embryonic and other stem cells. To date, these US patents remain valid despite an increasing onslaught of challenges in court. However, recent precedents established in US courts significantly narrow the scope of patent eligibility within biotechnology. This article compares the implications of recent legal changes on stem cell patent eligibility between the EU and US.

  18. Red cell storage age policy for patients with sickle cell disease: A survey of transfusion service directors in the United States.

    Science.gov (United States)

    Karafin, Matthew S; Singavi, Arun K; Irani, Mehraboon S; Puca, Kathleen E; Baumann Kreuziger, Lisa; Simpson, Pippa; Field, Joshua J

    2016-02-01

    In patients with sickle cell disease (SCD), the effects of the red cell storage lesion are not well defined. The objective of this study was to determine the prevalence of transfusion services that limit red cell units by storage age for patients with SCD. We developed a 22 question survey of transfusion service director opinions and their corresponding blood bank policies. Target subjects were systematically identified on the AABB website. Responses were recorded in SurveyMonkey and summarized using standard statistical techniques. Ninety transfusion service directors responded to the survey. Response rate was 22%. Only 23% of respondents had storage age policies in place for patients with SCD, even though 36% of respondents consider older units to be potentially harmful in this patient population. Of those with a policy, a less-than 15 day storage age requirement was most often used (75%), but practices varied, and most respondents (65%) agreed that evidence-based guidelines regarding storage age are needed for patients with SCD. Policies, practices and opinions about the risks of older units for patients with SCD vary. As patients with SCD may have unique susceptibilities to features of the red cell storage lesion, prospective studies in this population are needed to determine best practice.

  19. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    Md. Moinul Islam

    2015-01-01

    Full Text Available A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR and capacitance-loaded strip (CLS unit cells is presented for Ultra wideband (UWB microwave imaging applications. Four left-handed (LH metamaterial (MTM unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR with a capacitance-loaded strip (CLS to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

  20. On the Effect of Unit-Cell Parameters in Predicting the Elastic Response of Wood-Plastic Composites

    Directory of Open Access Journals (Sweden)

    Fatemeh Alavi

    2013-01-01

    Full Text Available This paper presents a study on the effect of unit-cell geometrical parameters in predicting elastic properties of a typical wood plastic composite (WPC. The ultimate goal was obtaining the optimal values of representative volume element (RVE parameters to accurately predict the mechanical behavior of the WPC. For each unit cell, defined by a given combination of the above geometrical parameters, finite element simulation in ABAQUS was carried out, and the corresponding stress-strain curve was obtained. A uniaxial test according to ASTM D638-02a type V was performed on the composite specimen. Modulus of elasticity was determined using hyperbolic tangent function, and the results were compared to the sets of finite element analyses. Main effects of RVE parameters and their interactions were demonstrated and discussed, specially regarding the inclusion of two adjacent wood particles within one unit cell of the material. Regression analysis was performed to mathematically model the RVE parameter effects and their interactions over the modulus of elasticity response. The model was finally employed in an optimization analysis to arrive at an optimal set of RVE parameters that minimizes the difference between the predicted and experimental moduli of elasticity.

  1. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications.

    Science.gov (United States)

    Islam, Md Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

    2015-01-23

    A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm³, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4-12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

  2. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

    Science.gov (United States)

    Islam, Md. Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md.; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

    2015-01-01

    A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications. PMID:28787945

  3. Intra-unit-cell magnetic correlations near optimal doping in YBa2Cu3O6.85.

    Science.gov (United States)

    Mangin-Thro, L; Sidis, Y; Wildes, A; Bourges, P

    2015-07-03

    The pseudo-gap phenomenon in copper oxide superconductors is central to any description of these materials as it prefigures the superconducting state itself. A magnetic intra-unit-cell order was found to occur just at the pseudo-gap temperature in four cuprate high-Tc superconducting families. Here we present polarized neutron-scattering measurements of nearly optimally doped YBa2Cu3O6.85, carried out on two different spectrometers, that reveal several features. The intra-unit-cell order consists of finite-sized planar domains that are very weakly correlated along the c axis. At high temperature, only the out-of-plane magnetic components correlate, indicating a strong Ising anisotropy. An aditional in-plane response develops at low temperature, giving rise to an apparent tilt of the magnetic moment. The discovery of these two regimes puts stringent constraints, which are tightly bound to the pseudo-gap physics, on the intrinsic nature of intra-unit-cell order.

  4. Monoclinic-to-orthorhombic phase transition of the hexamethylenetetramine-2-methylbenzoic acid (1/2) cocrystal with temperature-dependent dynamic molecular disorder.

    Science.gov (United States)

    Chia, Tze Shyang; Quah, Ching Kheng

    2016-12-01

    As a function of temperature, the hexamethylenetetramine-2-methylbenzoic acid (1/2) cocrystal, C6H12N4·2C8H8O2, undergoes a reversible structural phase transition. The orthorhombic high-temperature phase in the space group Pccn has been studied in the temperature range between 165 and 300 K. At 164 K, a t2 phase transition to the monoclinic subgroup P21/c space group occurs; the resulting twinned low-temperature phase was investigated in the temperature range between 164 and 100 K. The domains in the pseudomerohedral twin are related by a twofold rotation corresponding to the matrix (100/0-10/00-1. Systematic absence violations represent a sensitive criterium for the decision about the correct space-group assignment at each temperature. The fractional volume contributions of the minor twin domain in the low-temperature phase increases in the order 0.259 (2) → 0.318 (2) → 0.336 (2) → 0.341 (3) as the temperature increases in the order 150 → 160 → 163 → 164 K. The transformation occurs between the nonpolar point group mmm and the nonpolar point group 2/m, and corresponds to a ferroelastic transition or to a t2 structural phase transition. The asymmetric unit of the low-temperature phase consists of two hexamethylenetetramine molecules and four molecules of 2-methylbenzoic acid; it is smaller by a factor of 2 in the high-temperature phase and contains two half molecules of hexamethylenetetramine, which sit across twofold axes, and two molecules of the organic acid. In both phases, the hexamethylenetetramine residue and two benzoic acid molecules form a three-molecule aggregate; the low-temperature phase contains two of these aggregates in general positions, whereas they are situated on a crystallographic twofold axis in the high-temperature phase. In both phases, one of these three-molecule aggregates is disordered. For this disordered unit, the ratio between the major and minor conformer increases upon cooling from

  5. Fuel Cell Backup Power Unit Configuration and Electricity Market Participation: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhiwen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Eichman, Josh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-03-13

    This National Renewable Energy Laboratory industry-inspired Laboratory Directed Research and Development project evaluates the feasibility and economics of using fuel cell backup power systems in cell towers to provide grid services (e.g., balancing, ancillary services, demand response). The work is intended to evaluate the integration of thousands of under-utilized, clean, efficient, and reliable fuel cell systems that are already installed in cell towers for potential grid and ancillary services.

  6. Reaggregation of human, chick, and human embryonic brain cells. Factors influencing the formation of a histiotypic unit.

    Science.gov (United States)

    Lodin, Z; Fleischmannová, V; Hájková, B; Faltin, J; Hartman, J

    1981-01-01

    1. Aggregation of embryo human, mouse, and chick brain cells was studied. The optimum age interval of donors from different species was determined. 2. The significance of different dissociation procedures (mild trypsinisation followed by sieving, trypsinisation + DNA digestion, mechanical dissociation in 1 or 2 steps, and Ca2+ chelation by EGTA) for the rate of aggregation was estimated. A significant reduction of aggregation was observed after one step mechanical dissociation. Nonspecific adhesion of cells on DNA molecules was found only during the first stages of aggregation. 3. The curve of aggregation kinetics follows the curve of floculation kinetics. 90% free cells disappear from the medium after 2 h of aggregation and a large number of microaggregates are formed which condense after 20 to 24 h into compact aggregates. The time course of aggregation was similar for all cells dissociated by different means. Small differences in the rate of aggregation, caused by dissociation procedures, were apparent only during the first stages of aggregation. 4. The histiotypic unit formed by aggregation of human, mouse, and chick embryo brain cells exhibits some common and some specific features. During aggregation a multiple structural reconstruction takes place and a limited number of cells are exchanged or sorted out from aggregates into the medium. 5. The structural organisation of aggregates from differently dissociated cells differs in several aspects. This indicates that membrane surface structures are influenced differently by dissociation and behave differently during distinct stages of aggregation.

  7. Single crystalline monoclinic La0.7Sr0.3MnO3 nanowires with high temperature ferromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Carretero-Genevrier, Adrian [ICMAB, Barcelona, Spain; Gazquez Alabart, Jaume [ORNL; Idrobo Tapia, Juan C [ORNL; Oro, Judith [ICMAB, Barcelona, Spain; Arbiol, Jordi [ICMAB, Barcelona, Spain; Varela del Arco, Maria [ORNL; Ferain, Etienne [Universite catholique de Louvain, Belgium (UCL); Rodriguez-Carvajal, Juan [Institut Laue-Langevin (ILL); Puig, Teresa [ICMAB, Barcelona, Spain; Mestres, Narcis [ICMAB, Barcelona, Spain; Obradors, Xavier [ICMAB, Barcelona, Spain

    2011-01-01

    Porous mixed-valent manganese oxides are a group of multifunctional materials that can be used as molecular sieves, catalysts, battery materials, and gas sensors. However, material properties and thus activity can vary significantly with different synthesis methods or process conditions, such as temperature and time. Here, we report on a new synthesis route for MnO{sub 2} and LaSr-doped molecular sieve single crystalline nanowires based on a solution chemistry methodology combined with the use of nanoporous polymer templates supported on top of single crystalline substrates. Because of the confined nucleation in high aspect ratio nanopores and of the high temperatures attained, new structures with novel physical properties have been produced. During the calcination process, the nucleation and crystallization of {var_epsilon}-MnO{sub 2} nanoparticles with a new hexagonal structure is promoted. These nanoparticles generated up to 30 {mu}m long and flexible hexagonal nanowires at mild growth temperatures (T{sub g} = 700 C) as a consequence of the large crystallographic anisotropy of {var_epsilon}-MnO{sub 2}. The nanocrystallites of MnO{sub 2} formed at low temperatures serve as seeds for the growth of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} nanowires at growth temperatures above 800 C, through the diffusion of La and Sr into the empty 1D-channels of {var_epsilon}-MnO{sub 2}. Our particular growth method has allowed the synthesis of single crystalline molecular sieve (LaSr-2 x 4) monoclinic nanowires with composition La{sub 0.7}Sr{sub 0.3}MnO{sub 3} and with ordered arrangement of La{sup 3+} and Sr{sup 2+} cations inside the 1D-channels. These nanowires exhibit ferromagnetic ordering with strongly enhanced Curie temperature (T{sub c} > 500 K) that probably results from the new crystallographic order and from the mixed valence of manganese.

  8. Compressor-expander units for mobile fuel cell systems; Verdichter und Expander fuer mobile Brennstoffzellensysteme

    Energy Technology Data Exchange (ETDEWEB)

    Lang, O. [FEV Motorentechnik GmbH, Aachen (Germany).; Pischinger, S.; Schoenfelder, C.; Steidten, T. [RWTH Aachen (DE). Lehrstuhl fuer Verbrennungskraftmaschinen (VKA)

    2004-08-01

    The air supply of hydrogen-powered fuel cell systems containing PEM fuel cells has a significant impact on their efficiency and mode of operation. Therefore, several mechanical compressors and expanders were examined at the RWTH Aachen. Simulations were then performed to determine the behaviour of the fuel cell system. This article discusses the findings of a project commissioned by the Forschungsvereinigung Verbrennungskraftmaschinen e.V. (FVV). (orig.)

  9. Q Fever Outbreak Among Travelers to Germany Who Received Live Cell Therapy--United States and Canada, 2014.

    Science.gov (United States)

    Robyn, Misha P; Newman, Alexandra P; Amato, Michael; Walawander, Mary; Kothe, Cynthia; Nerone, James D; Pomerantz, Cynthia; Behravesh, Casey Barton; Biggs, Holly M; Dahlgren, F Scott; Pieracci, Emily G; Whitfield, Yvonne; Sider, Doug; Ozaldin, Omar; Berger, Lisa; Buck, Peter A; Downing, Mark; Blog, Debra

    2015-10-02

    During September–November 2014, the New York State Department of Health (NYSDOH) was notified of five New York state residents who had tested seropositive for Coxiella burnetii, the causative agent of Q fever. All five patients had symptoms compatible with Q fever (e.g., fever, fatigue, chills, and headache) and a history of travel to Germany to receive a medical treatment called "live cell therapy" (sometimes called "fresh cell therapy") in May 2014. Live cell therapy is the practice of injecting processed cells from organs or fetuses of nonhuman animals (e.g., sheep) into human recipients. It is advertised to treat a variety of health conditions. This practice is unavailable in the United States; however, persons can travel to foreign locations to receive injections. Local health departments interviewed the patients, and NYSDOH notified CDC and posted a report on CDC’s Epidemic Information Exchange to solicit additional cases. Clinical and exposure information for each patient was reported to the Robert Koch Institute in Germany, which forwarded the information to local health authorities. A Canada resident who also received live cell therapy in May 2014 was diagnosed with Q fever in July 2014. Clinicians should be aware of health risks, such as Q fever and other zoonotic diseases, among patients with a history of receiving treatment with live cell therapy products.

  10. Quasi bound states in the continuum with few unit cells of photonic crystal slab

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Chung, Il-Sug

    2017-01-01

    Bound states in the continuum (BICs) in photonic crystal slabs represent the resonances with an infinite quality (Q)-factor, occurring above the light line for an infinitely periodic structure. We show that a set of BICs can turn into quasi-BICs with a very high Q-factor even for two or three unit...

  11. Development of a unit suitable for corrosion monitoring in district heating systems. Experiences with the LOCOR-cell test method

    DEFF Research Database (Denmark)

    Andersen, Asbjørn; Hilbert, Lisbeth Rischel

    2004-01-01

    the purpose, background and gained results of one of the used monitoring techniques, the crevice corrosion measurements obtained by the LOCOR-Cell„§. The crevice corrosion cell was developed by FORCE Technology in a previous district heating project financed by Nordic Industrial Fund (1)(2). Results from...... in 6 pressurised circulating heating systems and in one cooling system. 7 different corrosion monitoring methods have been used to study corrosion rates and types in dependency of water chemistry. This paper describes the design of the by-pass unit including water analysis methods. It also describes...... other used corrosion monitoring methods in the project are described elsewhere (3) and (4). For future district heating corrosion monitoring the by-pass unit can be recommended for permanent installation and the two methods high sensitive ER-technique (Metricorr) and the LOCOR-Cell„§ (FORCE Technology...

  12. Development of a unit suitable for corrosion monitoring in district heating systems. Experiences with the LOCOR-cell test method

    DEFF Research Database (Denmark)

    Andersen, Asbjørn; Hilbert, Lisbeth Rischel

    2004-01-01

    the purpose, background and gained results of one of the used monitoring techniques, the crevice corrosion measurements obtained by the LOCOR-Cell„§. The crevice corrosion cell was developed by FORCE Technology in a previous district heating project financed by Nordic Industrial Fund (1)(2). Results from...... in 6 pressurised circulating heating systems and in one cooling system. 7 different corrosion monitoring methods have been used to study corrosion rates and types in dependency of water chemistry. This paper describes the design of the by-pass unit including water analysis methods. It also describes...... other used corrosion monitoring methods in the project are described elsewhere (3) and (4). For future district heating corrosion monitoring the by-pass unit can be recommended for permanent installation and the two methods high sensitive ER-technique (Metricorr) and the LOCOR-Cell„§ (FORCE Technology...

  13. Heterodimeric barnase-barstar vaccine molecules: influence of one versus two targeting units specific for antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Heidi Cecilie Larsen Spång

    Full Text Available It is known that targeting of antigen to antigen presenting cells (APC increases immune responses. However, it is unclear if more than one APC-specific targeting unit in the antigenic molecule will increase responses. To address this issue, we have here made heterodimeric vaccine molecules that each express four different fusion subunits. The bacterial ribonuclease barnase and its inhibitor barstar interact with high affinity, and the barnase-barstar complex was therefore used as a dimerization unit. Barnase and barstar were fused N-terminally with single chain fragment variable (scFvs targeting units specific for either MHC class II molecules on APC or the hapten 5-iodo-4-hydroxy-3-nitrophenylacetyl (NIP. C-terminal antigenic fusions were either the fluorescent protein mCherry or scFv(315 derived from myeloma protein M315. The heterodimeric vaccine molecules were formed both in vitro and in vivo. Moreover, the four different fused moieties appeared to fold correctly since they retained their specificity and function. DNA vaccination with MHC class II-targeted vaccine induced higher mCherry-specific IgG1 responses compared to non-targeted control. Since mCherry and MHC class II are in trans in this heterodimer, this suggests that heterodimeric proteins are formed in vivo without prior protein purification. Surprisingly, one targeting moiety was sufficient for the increased IgG1 response, and addition of a second targeting moiety did not increase responses. Similar results were found in in vitro T cell assays; vaccine molecules with one targeting unit were as potent as those with two. In combination with the easy cloning strategy, the heterodimeric barnase-barstar vaccine molecule could provide a flexible platform for development of novel DNA vaccines with increased potency.

  14. Inter-relationships between single carbon units' metabolism and resting energy expenditure in weight-losing patients with small cell lung cancer. Effects of methionine supply and chemotherapy

    DEFF Research Database (Denmark)

    Sengeløv, H; Hansen, O P; Simonsen, L;

    1994-01-01

    The one-carbon unit metabolism was investigated in 8 weight-losing patients with small cell carcinoma of the lung (SCLC). At diagnosis, 6 of the 8 patients had elevated formiminoglutamic acid (FIGLU) excretion after a histidine load, suggesting a lack of one-carbon units. In accordance, a signifi...

  15. Quantification of in situ temperature measurements on a PBI-based high temperature PEMFC unit cell

    DEFF Research Database (Denmark)

    Lebæk, Jesper; Ali, Syed Talat; Møller, Per

    2010-01-01

    The temperature is a very important operating parameter for all types of fuel cells. In the present work distributed in situ temperature measurements are presented on a polybenzimidazole based high temperature PEM fuel cell (HT-PEM). A total of 16 T-type thermocouples were embedded on both...... sensors showed minimal influence on cell performance, this difference seen in performance is believed to be caused by different bipolar plate materials. The measurement method is suitable for obtaining detailed data for validation of computational models, moreover the results indicate that the method can...

  16. Logistics and Capability Implications of a Bradley Fighting Vehicle with a Fuel Cell Auxiliary Power Unit

    Science.gov (United States)

    2003-10-13

    Husted, John MacBain Delphi Corporation Heather McKee US Army TACOM Copyright © 2003 SAE International ABSTRACT Modern military ground vehicles are...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Delphi Corporation,5725 Delphi Drive,Troy,Mi,48098 8. PERFORMING ORGANIZATION... injector hardware change. A single, 28V, 400A permanent-magnet direct current (DC) generator is driven by a power take off (PTO) directly connected to

  17. Evaluation of eicosanoid concentrations in stored units of canine packed red blood cells.

    Science.gov (United States)

    Blake, Rachel R; Lee, Jung Hwa; Ross, Matt K; Archer, Todd M; Wills, Robert W; Mackin, Andrew J; Thomason, John M

    2017-01-15

    OBJECTIVE To evaluate eicosanoid concentrations in freshly prepared canine packed RBCs (PRBCs) and to assess changes in eicosanoid concentrations in PRBC units over time during storage and under transfusion conditions. DESIGN Prospective study. SAMPLE 25 plasma samples from 14 healthy Greyhounds. PROCEDURES Plasma samples were obtained during PRBC preparation (donation samples), and the PRBC units were then stored at 4°C until used for transfusion (≤ 21 days later; n = 17) or mock transfusion if expired (22 to 24 days later; 8). Immediately prior to use, 100 mL of saline (0.9% NaCl) solution was added to each unit and a pretransfusion sample was collected. A posttransfusion sample was collected after transfusion or mock transfusion. Concentrations of arachidonic acid, prostaglandin (PG) F2α, PGE2, PGD2, thromboxane B2, 6-keto-PGF1α, and leukotriene B4 were measured by liquid chromatography-mass spectrometry and analyzed statistically. RESULTS Median arachidonic acid concentration was significantly decreased in posttransfusion samples, compared with the concentration in donation samples. Median PGF2α, 6-keto-PGF1α, and leukotriene B4 concentrations were significantly increased in pretransfusion samples, compared with those in donation samples. Median PGF2α, thromboxane B2, and 6-keto-PGF1α concentrations were significantly increased in posttransfusion samples, compared with those in pretransfusion samples. Duration of PRBC storage had significant associations with pretransfusion and posttransfusion arachidonic acid and thromboxane B2 concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Concentrations of several proinflammatory eicosanoids increased in PRBC units during storage, transfusion, or both. Accumulation of these products could potentially contribute to adverse transfusion reactions, and investigation of the potential association between eicosanoid concentrations in PRBCs and the incidence of transfusion reactions in dogs is warranted.

  18. Trapped-Mode Resonance Regime of Thin Microwave Electromagnetic Arrays with Two Concentric Rings in Unit Cell

    Directory of Open Access Journals (Sweden)

    M. N. Kawakatsu

    2011-01-01

    Full Text Available We present a theoretical study of reflection and transmission characteristics of a microwave planar array on a thin dielectric substrate with unit cell made of two concentric rings. This array possesses high quality factor transmission resonance with polarization insensitivity for normally incident plane wave. This resonance is defined by the trapped-mode regime. We show that for oblique incidence, there are some differences in characteristics of the array and a small change in quality factor of the trapped-mode resonance.

  19. Comparison of fuel-cell and diesel integrated energy systems and a conventional system for a 500-unit apartment

    Science.gov (United States)

    Simons, S. N.; Maag, W. L.

    1978-01-01

    The electrical and thermal energy utilization efficiencies of a 500 unit apartment complex are analyzed and compared for each of three energy supply systems. Two on-site integrated energy systems, one powered by diesel engines and the other by phosphoric-acid fuel cells were compared with a conventional system which uses purchased electricity and on-site boilers for heating. All fuels consumed on-site are clean, synthetic fuels (distillate fuel oil or pipeline quality gas) derived from coal. Purchased electricity was generated from coal at a central station utility. The relative energy consumption and economics of the three systems are analyzed and compared.

  20. Oil and Gas Exploration and Production in the United States Shown as Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A cells polygon feature class was created by the U.S. Geological Survey (USGS) to illustrate the degree of exploration, type of production, and distribution of...

  1. M(o)ssbauer spectroscopic study of monoclinic astrophyllite%单斜星叶石矿物的穆斯堡尔光谱学研究

    Institute of Scientific and Technical Information of China (English)

    苏文; 施倪承; 刘密兰; 马喆生; 李哲; Alexandr KHOMYAKOV

    2008-01-01

    Monoclinic astrophyllite from Kala Peninsula, Russia was investigated by 57Fe Mossbauer effect. The Mossbauer spectra of the sample at 298 K, 180 K and 80 K were measured. Each spectrum of monoclinic astrophyllite consists of two Fe2+ and one Fe3+ quadrupole doublets. The distortion parameters, the variances of the octahedral bond angles 0-2 and the normalized bond-length variation △ for monoclinic astrophyllite were calculated. However, since a discrepancy between two distortion parameters exists, an assignment of the quadrupole doublet to iron at the specific site was not given. Temperature dependences of the isomer shift and the quadrupole splitting were presented and discussed. According to the ratio of ferric to total iron obtained by the Mossbauer effect and the mean value off ( Fe3+ (O) )/f ( Fe2+ (O) ), the chemical formula of monoclinic astrophyllite was rewritten.%本文对产于俄罗斯希宾地区的单斜星叶石进行了不同的温度条件下的穆斯堡尔光谱效应研究.通过在温度分别在298 K,180 K和80 K条件下的分析,发现单斜星叶石由2个Fe2+和1个Fe3+四极双峰组成,并进行了单斜星叶石中的畸变参数包括八面体键角(σ2)和键长变量(△)的计算.但是,在两个畸变参数之间存在着明显的差异,将无法对它们的穆斯堡尔参数和四极双峰进行指派.本文对温度在同质异能位移和四极分裂中的作用进行了探讨,根据通过穆斯堡尔效应和f(Fe3+(O))/f(Fe2+(O))的平均值获得的三价铁对全铁的比值,改写了单斜星叶石的化学式.

  2. Cubic-to-monoclinic phase transition during the epitaxial growth of crystalline Gd2O3 films on Ge(001) substrates

    Science.gov (United States)

    Molle, Alessandro; Wiemer, Claudia; Bhuiyan, Md. Nurul Kabir; Tallarida, Grazia; Fanciulli, Marco; Pavia, Giuseppe

    2007-05-01

    Thin crystalline films of Gd2O3 are grown on an atomically flat Ge(001) surface by molecular beam epitaxy and are characterized in situ by reflection high energy electron diffraction and x-ray photoelectron spectroscopy, and ex situ by x-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy. The first stage of the growth corresponds to a cubic (110) structure, with two equiprobable, 90° rotated, in-plane domains. Increasing the thickness of the films, a phase transition from cubic (110) to monoclinic (100) oriented crystallites is observed which keeps the in-plane domain rotation, as evidenced by XRD and AFM.

  3. Lifting the geometric frustration through a monoclinic distortion in “114” YBaFe{sub 4}O{sub 7.0}: Magnetism and transport

    Energy Technology Data Exchange (ETDEWEB)

    Duffort, V.; Sarkar, T. [CRISMAT, CNRS-ENSICAEN, 6 Bd Marechal Juin, 14050 Caen (France); Caignaert, V., E-mail: vincent.caignaert@ensicaen.fr [CRISMAT, CNRS-ENSICAEN, 6 Bd Marechal Juin, 14050 Caen (France); Pralong, V.; Raveau, B. [CRISMAT, CNRS-ENSICAEN, 6 Bd Marechal Juin, 14050 Caen (France); Avdeev, M. [Bragg Institute, Australian Nuclear Science and Technology Organization, PMB 1, Menai, NSW 2234 (Australia); Cervellino, A. [Paul Scherrer Institute, Swiss Light Source, CH-5232 Villigen (Switzerland); Waerenborgh, J.C.; Tsipis, E.V. [UCQR, IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, CFMC-UL, 2686-953 Sacavém (Portugal)

    2013-09-15

    The possibility to lift the geometric frustration in the “114” stoichiomeric tetragonal oxide YBaFe{sub 4}O{sub 7.0} by decreasing the temperature has been investigated using neutron and synchrotron powder diffraction techniques. Besides the structural transition from tetragonal to monoclinic symmetry that appears at T{sub S}=180 K, a magnetic transition is observed below T{sub N}=95 K. The latter corresponds to a lifting of the 3D geometric frustration toward an antiferromagnetic long range ordering, never observed to date in a cubic based “114’” oxide. The magnetic structure, characterized by the propagation vector k{sub 1}=(0,0,½), shows that one iron Fe2 exhibits a larger magnetic moment than the three others, suggesting a possible charge ordering according to the formula YBaFe{sup 3+}Fe{sub 3}{sup 2+}O{sub 7.0}. The magnetic M(T) and χ′(T) curves, in agreement with neutron data, confirm the structural and magnetic transitions and evidence the coexistence of residual magnetic frustration. Moreover, the transport measurements show a resistive transition from a thermally activated conduction mechanism to a variable range hopping mechanism at T{sub S}=180 K, with a significant increase of the dependence of the resistivity vs. temperature. Mössbauer spectroscopy clearly evidences a change in the electronic configuration of the iron framework at the structural transition as well as coexistence of several oxidation states. The role of barium underbonding in these transitions is discussed. - Graphical abstract: Atomic displacements at the tetragonal-monoclinic transition in YBaFe{sub 4}O{sub 7}. Display Omitted - Highlights: • The structural and magnetic phase transitions of YBaFe{sub 4}O{sub 7} were studied below room temperature. • The tetragonal to monoclinic transition, characterized by NPD and SXRD, was studied using mode crystallography approach. • Monoclinic distortion allows the lifting of the geometrical frustration on the iron sublattice

  4. The monoclinic form of 2,9-dichloro-5,12-dihydroquino[2,3-b] acridine-7,14-dithione dimethylacetamide disolvate

    OpenAIRE

    Hoki, T.; Senju, T.; Mizuguchi, Jin

    2005-01-01

    The title compound, C(20)H(10)Cl(2)N(2)S(2)(.)2C(4)H(9)NO, is a dimethylacetamide (DMA) disolvate of DTQ-Cl, which is a thionated derivative of a 2,9-dichloroquinacridone pigment. The compound shows polymorphism and this paper reports the monoclinic form ( space group P2(1)/c, Z = 4). Two DMA molecules are hydrogen bonded via their O atoms to the NH group of DTQ-Cl. The molecular planes of the two DMA molecules are asymmetrically twisted with respect to the DTQ-Cl skeleton by 11.65 (8) and 31...

  5. Equation of state and thermodynamic Grüneisen parameter of monoclinic 1,1-diamino-2,2-dinitroethylene

    Science.gov (United States)

    Zhang, Jianzhong; Velisavljevic, Nenad; Zhu, Jinlong; Wang, Liping

    2016-10-01

    In situ synchrotron x-ray diffraction experiments were conducted on 1,1-diamino-2,2-dinitroethylene (FOX-7) at pressures up to 6.8 GPa and temperatures up to 485 K. Within the resolution of the present diffraction data, our results do not reveal evidence for a pressure-induced structural phase transition near 2 GPa, previously observed in several vibrational spectroscopy experiments. Based on unit-cell volume measurements, the least-squares fit using the third-order Birch-Murnaghan equation of state (EOS) yields K 0  =  12.6  ±  1.4 GPa and K0\\prime   =  11.3  ±  2.1 for the α-phase of FOX-7, which are in good agreement with recently reported values for the deuterated sample, indicating that the effect of hydrogen-deuterium substitution on the compressibility of FOX-7 is negligibly small. A thermal EOS is also obtained for the α-phase of FOX-7, including pressure dependence of thermal expansivity, (∂α/∂P)T  =  -7.0  ±  2.0  ×  10-5 K-1 GPa-1, and temperature derivative of the bulk modulus, (∂K T/∂T)P  =  -1.1  ×  10-2 GPa K-1. From these EOS parameters, we calculate heat capacity at constant volume (C V) and thermodynamic Grüneisen parameter (γ TH) as a function of temperature. At ambient conditions, the calculated γ TH is 1.055, which is in good agreement with the value (1.09) previously obtained from density functional theory (DFT). The obtained C V, however, is 13% larger than that calculated from the first-principles calculations, indicating that the dispersion correction in the DFT calculations may need to be further improved for describing intermolecular interactions of molecular crystals.

  6. Fuel cell programs in the United States for stationary power applications

    Energy Technology Data Exchange (ETDEWEB)

    Singer, M.

    1996-04-01

    The Department of Energy (DOE), Office of Fossil Energy, is participating with the private sector in sponsoring the development of molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) technologies for application in the utility, commercial and industrial sectors. Phosphoric acid fuel cell (PAFC) development was sponsored by the Office of Fossil Energy in previous years and is now being commercialized by the private sector. Private sector participants with the Department of Energy include the Electric Power Research Institute (EPRI), the Gas Research institute (GRI), electric and gas utilities, universities, manufacturing companies and their suppliers. through continued government and private sector support, fuel cell systems are emerging power generation technologies which are expected to have significant worldwide impacts. An industry with annual sales of over a billion dollars is envisioned early in the 21st century. PAFC power plants have begun to enter the marketplace and MCFC and SOFC power plants are expected to be ready to enter the marketplace in the late 1990s. In support of the efficient and effective use of our natural resources, the fuel cell program seeks to increase energy efficiency and economic effectiveness of power generation. This is to be accomplished through effectiveness of power generation. This is accomplished through the development and commercialization of cost-effective, efficient and environmentally desirable fuel cell systems which will operate on fossil fuels in multiple and end use sectors.

  7. Temperature-dependent haemolytic propensity of CPDA-1 stored red blood cells vs whole blood - Red cell fragility as donor signature on blood units.

    Science.gov (United States)

    Tzounakas, Vassilis L; Anastasiadi, Alkmini T; Karadimas, Dimitrios G; Zeqo, Redisa A; Georgatzakou, Hara T; Pappa, Olga D; Papatzitze, Olga A; Stamoulis, Konstantinos E; Papassideri, Issidora S; Antonelou, Marianna H; Kriebardis, Anastasios G

    2017-09-01

    To preserve cellular integrity and avoid bacterial growth, storage and transfer of blood and blood products follow strict guidelines in terms of temperature control. We evaluated the impact of ineligible warming of whole blood donations on the quality of blood components. One-hundred and twenty units of whole blood (WB) from eligible blood donors were collected in CPDA-1 and stored at 4±2 °C. During shipment to the blood processing centre, a gradual warming up to 17 °C was recorded within a period of less than eight hours. The warmed units were processed to packed red blood cells (PRBCs) or stored as WB units at 4±2 °C. In-bag haemolysis, osmotic fragility (mean corpuscular fragility, MCF) and bacterial growth were assessed in blood and blood components throughout the storage period. Normal basal and early storage levels of haemolysis were recorded in both PRBC and WB units. Thereafter, PRBCs exhibited higher average in-bag haemolysis and MCF index compared to the WB units throughout the storage. Moreover, 14.3 and 52.4% of the PRBC units exceeded the upper permissible limit of 0.8% haemolysis at the middle (1.220±0.269%) or late (1.754±0.866%) storage period, respectively. MCF index was similar in all PRBCs at the middle of storage but significantly lower in the non-haemolysed compared to the haemolysed units of PRBCs on the last days. The fragility of stored RBCs was proportional to the donor-related values of day 2 samples (r=0.861, punits of PRBCs. Transient, gradient warming of whole blood from 4 to 17 °C led to increased incidence of in-bag haemolysis in PRBC but not in WB units. Haemolysis is a multi-parametric phenotype of stored blood, and MCF is a donor-related and highly dynamic measure that can, in part, predict the storage lesion.

  8. Rhomboidal [Cu4] coordination cluster from self-assembly of two asymmetric phenoxido-bridged Cu2 units: Role of 1,1-azido clips

    Indian Academy of Sciences (India)

    Avijit Sarkar; Aloke Kumar Ghosh; Moumita Pait; Haridas Mandal; Tufan Singha Mahapatra; Biswajit Sharangi; Mrinal Sarkar; Debashis Ray

    2012-11-01

    The coordination cluster [Cu2(-OMe)(1,1-N3)(-bcp)(N3)]2 (1; Hbcp = 2,6-bis(2-benzoyl-4-chloro-phenylimino)-methyl)-4-methylphenol, forming a new member within the rapidly growing family of Cu4 cluster complexes, has been synthesized and structurally characterized by X-ray crystallography. The complex crystallizes in the monoclinic system, space group P21/, with unit cell parameters a = 14.620(7) Å, b = 17.923(8) Å, c = 15.008(7) Å, = 115.815(14)° and Z = 2. It is the first example of a rhomboidal [Cu4] compound formed from 1,1-azido clipping of two methoxido bridged [Cu2] complexes showing asymmetric coordination from benzophenone oxygen atoms and terminal azido groups.

  9. Engineering aspects and hardware verification of a volume producable solid oxide fuel cell stack design for diesel auxiliary power units

    Science.gov (United States)

    Stelter, Michael; Reinert, Andreas; Mai, Björn Erik; Kuznecov, Mihail

    A solid oxide fuel cell (SOFC) stack module is presented that is designed for operation on diesel reformate in an auxiliary power unit (APU). The stack was designed using a top-down approach, based on a specification of an APU system that is installed on board of vehicles. The stack design is planar, modular and scalable with stamped sheet metal interconnectors. It features thin membrane electrode assemblies (MEAs), such as electrolyte supported cells (ESC) and operates at elevated temperatures around 800 °C. The stack has a low pressure drop in both the anode and the cathode to facilitate a simple system layout. An overview of the technical targets met so far is given. A stack power density of 0.2 kW l -1 has been demonstrated in a fully integrated, thermally self-sustaining APU prototype running with diesel and without an external water supply.

  10. Characterization of immune cells and cytokine localization in the rat utero-placental unit mid- to late gestation.

    Science.gov (United States)

    Tessier, Daniel R; Raha, Sandeep; Holloway, Alison C; Yockell-Lelièvre, Julien; Tayade, Chandrakant; Gruslin, Andrée

    2015-08-01

    The success of pregnancy is dependent on the precise regulation of the immune response within the utero-placental environment. Rats are beginning to be widely used as a model for human immune-related pregnancy complications. However, our knowledge of immune cells and cytokine localization in the rat utero-placental tissue is limited. The current study aimed to localize the immune cell populations, including uterine natural killer (uNK) cells, neutrophils, and macrophages within the rat utero-placental unit at two crucial gestational ages, gestational days 15.5 and 18.5. In addition, we characterized the distribution of the cytokines TNFα, IFNγ, and IL-10 in the utero-placental regions at both the above-mentioned gestational ages. Our study has demonstrated co-localization TNFα and IFNγ with uNK cells in perivascular regions of the rat mesometrial triangle at both gestational ages. Neutrophils and IL-10-positive cells were localized at the maternal-fetal interface and in the spiral artery lumen of the rat mesometrial triangle at both gestational ages. TNFα and IL-10 demonstrated a temporal change in the localization from GD15.5 to GD18.5, which coincides with the leading edge of trophoblast invasion into the mesometrial triangle. The current study furthers our knowledge of the localization of uterine immune cells and relevant cytokines, and provides a base from which to research the function of these immune cells and cytokines during rat pregnancy as a model to study human immune-related pregnancy complications.

  11. Global reorganisation of cis-regulatory units upon lineage commitment of human embryonic stem cells.

    Science.gov (United States)

    Freire-Pritchett, Paula; Schoenfelder, Stefan; Várnai, Csilla; Wingett, Steven W; Cairns, Jonathan; Collier, Amanda J; García-Vílchez, Raquel; Furlan-Magaril, Mayra; Osborne, Cameron S; Fraser, Peter; Rugg-Gunn, Peter J; Spivakov, Mikhail

    2017-03-23

    Long-range cis-regulatory elements such as enhancers coordinate cell-specific transcriptional programmes by engaging in DNA looping interactions with target promoters. Deciphering the interplay between the promoter connectivity and activity of cis-regulatory elements during lineage commitment is crucial for understanding developmental transcriptional control. Here, we use Promoter Capture Hi-C to generate a high-resolution atlas of chromosomal interactions involving ~22,000 gene promoters in human pluripotent and lineage-committed cells, identifying putative target genes for known and predicted enhancer elements. We reveal extensive dynamics of cis-regulatory contacts upon lineage commitment, including the acquisition and loss of promoter interactions. This spatial rewiring occurs preferentially with predicted changes in the activity of cis-regulatory elements and is associated with changes in target gene expression. Our results provide a global and integrated view of promoter interactome dynamics during lineage commitment of human pluripotent cells.

  12. A Micromechanical Unit Cell Model of 2 × 2 Twill Woven Fabric Textile Composite for Multi Scale Analysis

    Science.gov (United States)

    Dixit, A.; Mali, H. S.; Misra, R. K.

    2014-04-01

    Woven fabric based composite materials are being considered for potential structural applications in automotive and aircraft industries due to their better out of plane strength, stiffness and toughness properties than ordinary composite laminates. This paper presents the micromechanical unit cell model of 2 × 2 twill woven fabric textile composite for the estimation of in-plane elastic properties. Modelling of unit cell and its analysis for this new model is developed by using open source coded tool TexGen and finite element software, ABAQUS® respectively. The predicted values are in good agreement with the experimental results reported in literature. To ascertain the effectiveness of the developed model parametric studies have also been conducted on the predicted elastic properties in order to investigate the effects of various geometric parameters such as yarn spacing, fabric thickness, yarn width and fibre volume fraction. The scope of altering weave pattern and yarn characteristics is facilitated in this developed model. Further this model can be implemented for the multi-scale micro/macro-mechanical analysis for the calculation of strength and stiffness of laminates structure made of 2 × 2 twill composite.

  13. A review of high-temperature polymer electrolyte membrane fuel-cell (HT-PEMFC)-based auxiliary power units for diesel-powered road vehicles

    Science.gov (United States)

    Liu, Yongfeng; Lehnert, Werner; Janßen, Holger; Samsun, Remzi Can; Stolten, Detlef

    2016-04-01

    This paper presents an extensive review of research on the development of auxiliary power units with enhanced reformate tolerance for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). Developments in diesel reforming for fuel cells as auxiliary power units (APUs), single fuel cells and stacks and systems are outlined in detail and key findings are presented. Summaries of HT-PEMFC APU applications and start-up times for HT-PEMFC systems are then given. A summary of cooling HT-PEMFC stacks using a classic schematic diagram of a 24-cell HT-PEMFC stack, with a cooling plate for every third cell, is also presented as part of a stack analysis. Finally, a summary of CO tolerances for fuel cells is given, along with the effects of different CO volume fractions on polarization curves, the fraction of CO coverage, hydrogen coverage, anode overpotential and cell potential.

  14. Comparative X-ray diffraction study of the crystalline microstructure of tetragonal and monoclinic vanadium-zirconium dioxide solid solutions produced from gel precursors

    Energy Technology Data Exchange (ETDEWEB)

    Kojdecki, Marek Andrzej [Wojskowa Akademia Techniczna, Warszawa (Poland). Inst. Matematyki i Kryptologii; Ruiz de Sola, Esther; Alarcon, Javier [Valencia Univ., Burjasot (Spain). Dept. de Quimica Inorganica; Serrano, Francisco Javier; Amigo, Jose Maria [Valencia Univ., Burjasot (Spain). Dept. de Geologia

    2009-04-15

    The microstructural characteristics of solid solutions, prepared by heating dried gel precursors with nominal compositions V{sub x}Zr{sub 1-x}O{sub 2} (0{<=}x{<=}0.1) at 723 and 1573 K, were determined from X-ray diffraction patterns. The crystalline microstructure of the resulting specimens, characterized by a prevalent crystallite shape, a volume-weighted crystallite size distribution and a second-order lattice strain distribution, was found to depend on the vanadium content. A characteristic feature of all size distributions was their bimodality, explained as a result of transformations between tetragonal and monoclinic phases during thermal treatment. A comparative study of the microstructure of both zirconia phases has been carried out, enabling reconstruction of a probable course of crystallization of both pure and vanadium-doped zirconias: on heating a sample, nucleation and the early growth stages involve crystallites of both phases; then on annealing and cooling, the crystallites of one phase transform into the other, depending on the thermal treatment temperature. Each logarithmic normal component of the crystallite size distribution of the resulting phase can be attributed to one of these processes. The limit of solubility of vanadium in tetragonal and monoclinic zirconia is estimated from the microstructural characteristics. (orig.)

  15. High-pressure syntheses and crystal structures of monoclinic B-Ho{sub 2}O{sub 3} and orthorhombic HoGaO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Hering, Stefanie A. [Dept. Chemie und Biochemie, Ludwig-Maximilians-Univ. Muenchen (Germany); Huppertz, Hubert [Inst. fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Univ. Innsbruck (Austria)

    2009-09-15

    Monoclinic holmium sesquioxide B-Ho{sub 2}O{sub 3} and orthorhombic holmium orthogallate HoGaO{sub 3} were synthesized in a Walker-type multianvil apparatus under high-pressure / high-temperature conditions of 11.5 GPa / 1250 C and 7.5 GPa / 1250 C, respectively. Both crystal structures could be determined by single-crystal X-ray diffraction data, collected at r.t. The monoclinic holmium oxide crystallizes in the space group C2/m (Z = 6) with the parameters a = 1394.7(3), b = 350.83(7), c = 865.6(2) pm, {beta} = 100.23(3) . R1 = 0.0517, wR2 = 0.1130 (all data), and the orthorhombic compound HoGaO{sub 3} in Pnma (Z = 4) with the parameters a = 553.0(2), b = 753.6(2), c = 525.4(2) pm. R1 = 0.0222, and wR2 = 0.0303 (all data). (orig.)

  16. Electrochemical characterization of a polybenzimidazole-based high temperature proton exchange membrane unit cell

    DEFF Research Database (Denmark)

    Jespersen, Jesper Lebæk; Schaltz, Erik; Kær, Søren Knudsen

    2009-01-01

    Equivalent Circuit (EC) modeling key parameters, such as the membrane resistance, charge transfer resistance and gas transfer resistance are identified, however the physical interpretation of the parameters derived from EC's are doubtful as discussed in this paper. The EC model proposed, which is a modified...... Randles circuit, provides a reasonably good fit at all the conditions tested. The measurements reveal that the cell temperature is an important parameter, which influences the cell performance significantly, especially the charge transfer resistance proved to be very temperature dependent. The transport...... of oxygen to the Oxygen Reduction Reaction (ORR) likewise has a substantial effect on the impedance spectra, results showed that the gas transfer resistance has an exponential-like dependency on the air stoichiometry. Based on the present results and results found in recent publications it is still...

  17. Application of multivariate analysis toward biotech processes: case study of a cell-culture unit operation.

    Science.gov (United States)

    Kirdar, Alime Ozlem; Conner, Jeremy S; Baclaski, Jeffrey; Rathore, Anurag S

    2007-01-01

    This paper examines the feasibility of using multivariate data analysis (MVDA) for supporting some of the key activities that are required for successful manufacturing of biopharmaceutical products. These activities include scale-up, process comparability, process characterization, and fault diagnosis. Multivariate data analysis and modeling were performed using representative data from small-scale (2 L) and large-scale (2000 L) batches of a cell-culture process. Several input parameters (pCO2, pO2, glucose, pH, lactate, ammonium ions) and output parameters (purity, viable cell density, viability, osmolality) were evaluated in this analysis. Score plots, loadings plots, and VIP plots were utilized for assessing scale-up and comparability of the cell-culture process. Batch control charts were found to be useful for fault diagnosis during routine manufacturing. Finally, observations made from reviewing VIP plots were found to be in agreement with conclusions from process characterization studies demonstrating the effectiveness of MVDA as a tool for extracting process knowledge.

  18. Space Station Biological Research Project (SSBRP) Cell Culture Unit (CCU) and incubator for International Space Station (ISS) cell culture experiments.

    Science.gov (United States)

    Vandendriesche, Donald; Parrish, Joseph; Kirven-Brooks, Melissa; Fahlen, Thomas; Larenas, Patricia; Havens, Cindy; Nakamura, Gail; Sun, Liping; Krebs, Chris; de Luis, Javier; Vunjak-Novakovic, Gordana; Searby, Nancy D

    2004-03-01

    The CCU and Incubator are habitats under development by SSBRP for gravitational biology research on ISS. They will accommodate multiple specimen types and reside in either Habitat Holding Racks, or the Centrifuge Rotor, which provides selectable gravity levels of up to 2 g. The CCU can support multiple Cell Specimen Chambers, CSCs (18, 9 or 6 CSCs; 3, 10 or 30 mL in volume, respectively). CSCs are temperature controlled from 4-39 degrees C, with heat shock to 45 degrees C. CCU provides automated nutrient supply, magnetic stirring, pH/O2 monitoring, gas supply, specimen lighting, and video microscopy. Sixty sample containers holding up to 2 mL each, stored at 4-39 degrees C, are available for automated cell sampling, subculture, and injection of additives and fixatives. CSCs, sample containers, and fresh/spent media bags are crew-replaceable for long-term experiments. The Incubator provides a 4-45 degrees C controlled environment for life science experiments or storage of experimental reagents. Specimen containers and experiment unique equipment are experimenter-provided. The Specimen Chamber exchanges air with ISS cabin and has 18.8 liters of usable volume that can accommodate six trays and the following instrumentation: five relocatable thermometers, two 60 W power outlets, four analog ports, and one each relative humidity sensor, video port, ethernet port and digital input/output port.

  19. Increasing the repeating units of ethylene glycol-based dimethacrylates directed toward reduced oxidative stress and co-stimulatory factors expression in human monocytic cells.

    Science.gov (United States)

    Tamura, Atsushi; Fukumoto, Izumi; Yui, Nobuhiko; Matsumura, Mitsuaki; Miura, Hiroyuki

    2015-03-01

    The ethylene glycol-based dimethacrylates are commonly used in biomaterials and dental restorative materials as a cross-linking agent. In this study, toxic effect of triethylene glycol dimethacrylate (TEGDMA) and poly(ethylene glycol) dimethacrylates (PEG-DMAs) with various ethylene glycol repeating units was investigated in terms of cytotoxicity, oxidative stress, and the expression of co-stimulatory factors in human leukemia cell line (THP-1 cells) to verify the effect of ethylene glycol repeating units. Note that the 1-octanol/water partition coefficient of PEG-based dimethacrylates decreased with increasing the ethylene glycol repeating units, indicating that the hydrophilicity of PEG-DMAs increased with ethylene glycol repeating units. The toxic effect of PEG-DMAs such as cytotoxicity, oxidative stress, and the expression of CD86 in treated THP-1 cells are reduced with increasing the ethylene glycol repeating units in PEG-DMAs. However, the expression of CD54 in treated THP-1 cells was not influenced with the ethylene glycol repeating units and the maximal expression level of CD54 was observed at the concentration range of 2-4 mM for all samples. Accordingly, hydrophilic character of PEG-DMAs with long ethylene glycol chains definitely alleviates the some toxic aspect of PEG-based DMAs. This finding would provide important insight into the design of new biomaterials and dental materials with superior biocompatibility. © 2014 Wiley Periodicals, Inc.

  20. Synthesis of a new conjugated polymer composed of pyrene and bithiophene units for organic solar cells.

    Science.gov (United States)

    Lee, Sun-Young; Jung, Choong-Hwa; Kang, Jun; Kim, Hee-Joon; Shin, Won Suk; Yoon, Sung Cheol; Moon, Sang-Jin; Lee, Changjin; Hwang, Do-Hoon

    2011-05-01

    An alternating conjugated copolymer composed of pyrene and bithiophene units, poly(DHBT-alt-PYR) has been synthesized. The synthesized polymer was found to exhibit good solution processibility and thermal stability, losing less than 5% of their weight on heating to approximately 370 degrees C. The synthesized polymer showed its maximum absorption and peak PL emission at 401 and 548 nm, respectively. The optical band gap energy of the polymer was determined by absorption onset to be 2.64 eV. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the polymer was determined to be -5.48 and -2.84 eV by cyclic voltametry (CV) and the optical band gap. The polymer photovoltaic devices were fabricated with a typical sandwich structure of ITO/PEDOT:PSS/active layer/LiF/Al using poly(DHBT-alt-PYR) as an electron donor and C60-PCBM or C70-PCBM as electron acceptors. The open circuit voltage, short circuit current and fill factor of the device using C70-PCBM as an acceptor were 0.75 V, 3.80 mA/cm2 and 0.28, respectively, and the maximum power conversion efficiency of the device was 0.80%.

  1. Synthesis and properties of two novel copolymers based on squaraine and fluorene units for solar cell materials

    Institute of Scientific and Technical Information of China (English)

    Zheng Wang; Wei Zhang; Feng Tao; Kai Ge Meng; Long Yi Xi; Ying Li; Qing Jiang

    2011-01-01

    Two novel copolymers based on squaraine and fluorine units have been synthesized through palladium catalyzed Suzuki coupling reaction and Sonogashira coupling reaction, respectively. The structures and properties of the two copolymers were characterized by FT-IR, NMR, UV-vis absorbance (Abs), gel permeation chromatography (GPC), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and cyclic voltammetry (CV). The solution absorption spectrums of P1 and P2 show two distinct absorption bands, one locates at 300-500 nm and the other at 600-800 nm. The absorption spectrums of P1 and P2 in films are broadened obviously and the spectral responses are extended up to 900 nm. Thermal gravimetric analysis demonstrates that the polymers are stable. Cyclic voltammetry experiment shows that the band gaps of the copolymers are 1.65 eV and 1.67 eV, respectively, suggesting their potential for applications as solar cells materials.

  2. Laser Molecular Beam Epitaxy Growth of BaTiO3 in Seven Thousands of Unit-Cell Layers

    Institute of Scientific and Technical Information of China (English)

    HUANG Yan-Hong; YANG Guo-Zhen; HE Meng; ZHAO Kun; TIAN Huan-Fang; L(U) Hui-Bin; JIN Kui-Juan; CHEN Zheng-Hao; ZHOU Yue-Liang; LI Jian-Qi

    2005-01-01

    @@ BaTiO3 thin films in seven thousands of unit-cell layers have been successfully fabricated on SrTiO3 (001)substrates by laser molecular beam epitaxy. The fine streak pattern and the undamping intensity oscillation of reflection high-energy electron diffraction indicate that the BaTiO3 film was layer-by-layer epitaxial growth. The measurements of scanning electron microscopy and atomic force microscopy show that surfaces of the BaTiO3thin film are atomically smooth. The measurements of x-ray diffraction and transmission electron microscopy,as well as selected-area electron diffraction revealthat the BaTiO3 thin film is a c-oriented epitaxial crystalline structure.

  3. Efficient particle-in-cell simulation of auroral plasma phenomena using a CUDA enabled graphics processing unit

    Science.gov (United States)

    Sewell, Stephen

    This thesis introduces a software framework that effectively utilizes low-cost commercially available Graphic Processing Units (GPUs) to simulate complex scientific plasma phenomena that are modeled using the Particle-In-Cell (PIC) paradigm. The software framework that was developed conforms to the Compute Unified Device Architecture (CUDA), a standard for general purpose graphic processing that was introduced by NVIDIA Corporation. This framework has been verified for correctness and applied to advance the state of understanding of the electromagnetic aspects of the development of the Aurora Borealis and Aurora Australis. For each phase of the PIC methodology, this research has identified one or more methods to exploit the problem's natural parallelism and effectively map it for execution on the graphic processing unit and its host processor. The sources of overhead that can reduce the effectiveness of parallelization for each of these methods have also been identified. One of the novel aspects of this research was the utilization of particle sorting during the grid interpolation phase. The final representation resulted in simulations that executed about 38 times faster than simulations that were run on a single-core general-purpose processing system. The scalability of this framework to larger problem sizes and future generation systems has also been investigated.

  4. Conceptual design and selection of a biodiesel fuel processor for a vehicle fuel cell auxiliary power unit

    Science.gov (United States)

    Specchia, S.; Tillemans, F. W. A.; van den Oosterkamp, P. F.; Saracco, G.

    Within the European project BIOFEAT (biodiesel fuel processor for a fuel cell auxiliary power unit for a vehicle), a complete modular 10 kW e biodiesel fuel processor capable of feeding a PEMFC will be developed, built and tested to generate electricity for a vehicle auxiliary power unit (APU). Tail pipe emissions reduction, increased use of renewable fuels, increase of hydrogen-fuel economy and efficient supply of present and future APU for road vehicles are the main project goals. Biodiesel is the chosen feedstock because it is a completely natural and thus renewable fuel. Three fuel processing options were taken into account at a conceptual design level and compared for hydrogen production: (i) autothermal reformer (ATR) with high and low temperature shift (HTS/LTS) reactors; (ii) autothermal reformer (ATR) with a single medium temperature shift (MTS) reactor; (iii) thermal cracker (TC) with high and low temperature shift (HTS/LTS) reactors. Based on a number of simulations (with the AspenPlus® software), the best operating conditions were determined (steam-to-carbon and O 2/C ratios, operating temperatures and pressures) for each process alternative. The selection of the preferential fuel processing option was consequently carried out, based on a number of criteria (efficiency, complexity, compactness, safety, controllability, emissions, etc.); the ATR with both HTS and LTS reactors shows the most promising results, with a net electrical efficiency of 29% (LHV).

  5. Successful implementation of a packed red blood cell and fresh frozen plasma transfusion protocol in the surgical intensive care unit.

    Directory of Open Access Journals (Sweden)

    Benjamin E Szpila

    Full Text Available Blood product transfusions are associated with increased morbidity and mortality. The purpose of this study was to determine if implementation of a restrictive protocol for packed red blood cell (PRBC and fresh frozen plasma (FFP transfusion safely reduces blood product utilization and costs in a surgical intensive care unit (SICU.We performed a retrospective, historical control analysis comparing before (PRE and after (POST implementation of a restrictive PRBC/FFP transfusion protocol for SICU patients. Univariate analysis was utilized to compare patient demographics and blood product transfusion totals between the PRE and POST cohorts. Multivariate logistic regression models were developed to determine if implementation of the restrictive transfusion protocol is an independent predictor of adverse outcomes after controlling for age, illness severity, and total blood products received.829 total patients were included in the analysis (PRE, n=372; POST, n=457. Despite higher mean age (56 vs. 52 years, p=0.01 and APACHE II scores (12.5 vs. 11.2, p=0.006, mean units transfused per patient were lower for both packed red blood cells (0.7 vs. 1.2, p=0.03 and fresh frozen plasma (0.3 vs. 1.2, p=0.007 in the POST compared to the PRE cohort, respectively. There was no difference in inpatient mortality between the PRE and POST cohorts (7.5% vs. 9.2%, p=0.39. There was a decreased risk of urinary tract infections (OR 0.47, 95%CI 0.28-0.80 in the POST cohort after controlling for age, illness severity and amount of blood products transfused.Implementation of a restrictive transfusion protocol can effectively reduce blood product utilization in critically ill surgical patients with no increase in morbidity or mortality.

  6. Enhanced Performance of Polymer Solar Cells Comprising Diketopyrrolopyrrole-Based Regular Terpolymer Bearing Two Different π-Extended Donor Units.

    Science.gov (United States)

    Ko, Eun Yi; Park, Gi Eun; Lee, Dae Hee; Um, Hyun Ah; Shin, Jicheol; Cho, Min Ju; Choi, Dong Hoon

    2015-12-30

    New regular and random diketopyrrolopyrrole (DPP)-based terpolymers (i.e., Reg-PBDPPT and Ran-PBDPPT, respectively) bearing DPP as an electron deficient unit and 2,2'-bithiophene and (E)-1,2-di(thiophen-2-yl)ethene as electron donating units were designed and synthesized, and their performance in photovoltaic cells was investigated precisely. The absorption properties and highest occupied molecular orbital (HOMO) of Reg-PBDPPT were found to be different from those of Ran-PBDPPT. The results of grazing incidence X-ray diffraction experiments revealed that Ran-PBDPPT typically had a predominantly edge-on chain orientation on the substrate, whereas Reg-PBDPPT showed mixed chain orientation both in pristine and thermally annealed films. Although Reg-PBDPPT exhibited a lower degree of edge-on chain orientation on the substrate, the corresponding TFTs showed a high hole mobility of 0.42-0.96 cm(2) V(-1) s(-1) and maintained a high current on/off ratio (>10(6)). A polymer solar cell (PSC) composed of Reg-PBDPPT and PC71BM exhibited power conversion efficiencies (PCE) of 5.24-5.45%, which were higher than those of the Ran-PBDPPT-based PSCs. The enhanced efficiency was supported by an increase in the short circuit current, which is strongly related to the unique internal crystalline morphology and pronounced nanophase segregation behavior in the blend films. These results obviously manifested that this synthetic strategy for regular conjugated terpolymers could be employed to control morphological properties to obtain high-performance PSCs.

  7. Novel Organic Sensitizers Containing 2,6-Difunctionalized Anthracene Unit for Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Jiann T. Lin

    2012-08-01

    Full Text Available A series of new organic dyes comprising different amines as electron donors, 2-(6-substituted-anthracen-2-yl-thiophene as the π-conjugated bridge, and cyanoacrylic acid group as an electron acceptor and anchoring group, have been synthesized. There exists charge transfer transition from arylamine and anthracene to the acceptor in these compounds, as evidenced from the photophysical measurements and the computational results. Under one sun (AM 1.5 illumination, dye-sensitized solar cells (DSSCs using these dyes as the sensitizers exhibited efficiencies ranging from 1.62% to 2.88%, surpassing that using 9,10-difunctionalized anthracene-based sensitizer.

  8. Online estimation of internal stack temperatures in solid oxide fuel cell power generating units

    Science.gov (United States)

    Dolenc, B.; Vrečko, D.; Juričić, Ɖ.; Pohjoranta, A.; Pianese, C.

    2016-12-01

    Thermal stress is one of the main factors affecting the degradation rate of solid oxide fuel cell (SOFC) stacks. In order to mitigate the possibility of fatal thermal stress, stack temperatures and the corresponding thermal gradients need to be continuously controlled during operation. Due to the fact that in future commercial applications the use of temperature sensors embedded within the stack is impractical, the use of estimators appears to be a viable option. In this paper we present an efficient and consistent approach to data-driven design of the estimator for maximum and minimum stack temperatures intended (i) to be of high precision, (ii) to be simple to implement on conventional platforms like programmable logic controllers, and (iii) to maintain reliability in spite of degradation processes. By careful application of subspace identification, supported by physical arguments, we derive a simple estimator structure capable of producing estimates with 3% error irrespective of the evolving stack degradation. The degradation drift is handled without any explicit modelling. The approach is experimentally validated on a 10 kW SOFC system.

  9. Difference in the luminescence properties of orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}:Ln (Ln = Tb{sup 3+} and Dy{sup 3+})

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Adish; Shah, Alpa; Sudarsan, V., E-mail: vsudar@barc.gov.in; Vatsa, R.K.; Jain, V.K., E-mail: jainvk@barc.gov.in

    2015-04-15

    Highlights: • Improved emission colour purity with orthorhombic form of Y{sub 2}GeO{sub 5}. • Non-stationary quenching exists in orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}:Tb. • Ion pair formation and cross relaxation quenching operating for Y{sub 2}GeO{sub 5}:Dy samples. - Abstract: The luminescence properties of Tb{sup 3+} and Dy{sup 3+} doped orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5} are significantly different. Orthorhombic Y{sub 2}GeO{sub 5} doped with Tb{sup 3+} and Dy{sup 3+} ions gives bright green and blue emission upon UV light excitation with CIE coordinates (0.25, 0.46) and (0.25, 0.24), respectively. The monoclinic Y{sub 2}GeO{sub 5} doped with these ions exhibits light green and yellowish white emissions, respectively. This has been attributed to the differences in crystallographic environments around Y{sup 3+} ions in orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}. Quantum yield of emission for orthorhombic Y{sub 2}GeO{sub 5}:Tb (∼29%) is significantly higher than that of the monoclinic Y{sub 2}GeO{sub 5}:Tb (∼14%). Lifetime values corresponding to {sup 4}F{sub 9/2} level of Dy{sup 3+} ions in both monoclinic and orthorhombic forms of Y{sub 2}GeO{sub 5} follow an opposite trend with respect to {sup 5}D{sub 4} level of Tb{sup 3+} ions. This is attributed to difference in the concentration quenching mechanism operating for Tb{sup 3+} and Dy{sup 3+} ions.

  10. Selective laser melting: a unit cell approach for the manufacture of porous, titanium, bone in-growth constructs, suitable for orthopedic applications. II. Randomized structures.

    Science.gov (United States)

    Mullen, Lewis; Stamp, Robin C; Fox, Peter; Jones, Eric; Ngo, Chau; Sutcliffe, Christopher J

    2010-01-01

    In this study, the unit cell approach, which has previously been demonstrated as a method of manufacturing porous components suitable for use as orthopedic implants, has been further developed to include randomized structures. These random structures may aid the bone in-growth process because of their similarity in appearance to trabecular bone and are shown to carry legacy properties that can be related back to the original unit cell on which they are ultimately based. In addition to this, it has been shown that randomization improves the mechanical properties of regular unit cell structures, resulting in anticipated improvements to both implant functionality and longevity. The study also evaluates the effect that a post process sinter cycle has on the components, outlines the improved mechanical properties that are attainable, and also the changes in both the macro and microstructure that occur.

  11. Interleukin-8, interleukin-1β and tumour necrosis factor-α in sequential units of packed red blood cells collected from retired racing Greyhounds.

    Science.gov (United States)

    Purcell, S L; Claus, M; Hosgood, G; Smart, L

    2017-01-01

    We hypothesised that concentrations of interleukin-8 (IL-8), interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) would increase during storage in the third sequential unit (U3) of canine packed red blood cells (PRBC) collected from terminal donors in haemorrhagic shock. We further hypothesised that leucoreduction would prevent cytokine accumulation in U3 and that cytokine concentrations in U3 would be higher than in the first units (U1) collected from the same dogs. U1 and U3 were each collected from 12 anaesthetised healthy Greyhounds. Removal of leucocytes from half of each PRBC unit produced one leucoreduced (LR) and one non-leucoreduced (NLR) unit. Canine IL-8, IL-1β and TNF-α concentrations were measured in samples collected from the units during storage on days 0, 10, 20, 30 and 37. The IL-8 concentration in U3 NLR units was significantly higher on days 10, 20, 30 and 37 than on day 0 and was significantly higher than in the LR units at all time points. The IL-1β concentration in U3 did not change over time, or between LR and NLR units. TNF-α was not detected in any unit. There were no significant differences in IL-8 or IL-1β concentrations between U3 and U1 at any time point; however, some NLR U3 units had markedly elevated IL-8 concentrations at day 37 (2060-20,682 pg/mL) compared with NLR U1 units (3369-5280 pg/mL). NLR U3 units collected from dogs in haemorrhagic shock showed a significant increase in IL-8 concentrations during storage. Leucoreduction was effective at preventing the accumulation of IL-8. There was no difference detected between U3 and U1. © 2017 Australian Veterinary Association.

  12. Orthorhombic-to-monoclinic phase transition of Ta2NiSe5 induced by the Bose-Einstein condensation of excitons

    Science.gov (United States)

    Kaneko, T.; Toriyama, T.; Konishi, T.; Ohta, Y.

    2013-01-01

    Using the band structure calculation and mean-field analysis of the derived three-chain Hubbard model with phonon degrees of freedom, we discuss the origin of the orthorhombic-to-monoclinic phase transition of the layered chalcogenide Ta2NiSe5. We show that the Bose-Einstein condensation of excitonic electron-hole pairs cooperatively induces the instability of the phonon mode at momentum q→0 in the quasi-one-dimensional Ta-NiSe-Ta chain, resulting in the structural phase transition of the system. The calculated single-particle spectra reproduce the deformation of the band structure observed in the angle-resolved photoemission spectroscopy experiment.

  13. Study on optical properties of rare-earth ions in nanocrystalline monoclinic SrAl2O4: Ln (Ln = Ce3+, Pr3+, Tb3+).

    Science.gov (United States)

    Fu, Zuoling; Zhou, Shihong; Zhang, Siyuan

    2005-08-01

    SrAl(2)O(4): Ln (Ln = Ce(3+), Pr(3+), Tb(3+)) nanocrystals have been synthesized by the combustion method. The results of XRD indicated that the resulting SrAl(2)O(4): Ln (Ln = Ce(3+), Pr(3+), Tb(3+)) nanocrystals have a reduced and distorted monoclinic lattice compared with bulk materials. The spectral properties are measured, and it is found that the excitation peaks of 5d energy levels red shift in nanocrystals in contrast to that in bulk crystals. The mechanism of spectra and energy changes is investigated. The order of the degree of red shift for nano SrAl(2)O(4): Ln (Ln = Ce(3+), Pr(3+), Tb(3+)) crystals is Pr(3+) > Ce(3+) > Tb(3+), which is in good agreement with our predicted results.

  14. Triclinic-monoclinic-orthorhombic (T-M-O) structural transitions in phase diagram of FeVO4-CrVO4 solid solutions

    Science.gov (United States)

    Bera, Ganesh; Reddy, V. R.; Rambabu, P.; Mal, P.; Das, Pradip; Mohapatra, N.; Padmaja, G.; Turpu, G. R.

    2017-09-01

    Phase diagram of FeVO4-CrVO4 solid solutions pertinent with structural and magnetic phases is presented with unambiguous experimental evidences. Solid solutions Fe1-xCrxVO4 (0 ≤ x ≤ 1.0) were synthesized through the standard solid state route and studied by X-ray diffraction, scanning electron microscopy, energy dispersive spectra of X-rays, Raman spectroscopy, d.c. magnetization, and 57Fe Mössbauer spectroscopic studies. FeVO4 and CrVO4 were found to be in triclinic (P-1 space group) and orthorhombic structures (Cmcm space group), respectively. Cr incorporation into the FeVO4 lattice leads to the emergence of a new monoclinic phase dissimilar to the both end members of the solid solutions. In Fe1-xCrxVO4 up to x = 0.10, no discernible changes in the triclinic structure were found. A new structural monoclinic phase (C2/m space group) emerges within the triclinic phase at x = 0.125, and with the increase in Cr content, it gets stabilized with clear single phase signatures in the range of x = 0.175-0.25 as evidenced by the Rietveld analysis of the structures. Beyond x = 0.33, orthorhombic phase similar to CrVO4 (Cmcm space group) emerges and coexists with a monoclinic structure up to x = 0.85, which finally tends to stabilize in the range of x = 0.90-1.00. The Raman spectroscopic studies also confirm the structural transition. FeVO4 Raman spectra show the modes related to three nonequivalent V ions in the triclinic structure, where up to 42 Raman modes are observed in the present study. With the stabilization of structures having higher symmetry, the number of Raman modes decreases and the modes related to symmetry inequivalent sites collate into singular modes from the doublet structure. A systematic crossover from two magnetic transitions in FeVO4, at 21.5 K and 15.4 K to single magnetic transition in CrVO4, at 71 K (antiferromagnetic transition), is observed in magnetization studies. The intermediate solid solution with x = 0.15 shows two magnetic transitions

  15. A monoclinic polymorph of (R,R-4,4′-dibromo-2,2′-[cyclohexane-1,2-diylbis(nitrilomethanylylidene]diphenol

    Directory of Open Access Journals (Sweden)

    Kwang Ha

    2012-05-01

    Full Text Available The title compound, C20H20Br2N2O2, a tetradentate Schiff base, is the enantiomerically pure R,R-diastereomer of four possible stereoisomers. The molecular structure reveals two strong intramolecular O—H...N hydrogen bonds between the hydroxy O atom and the imino N atom, which each generate S(6 rings. In the crystal, molecules are stacked in columns along the a axis; when viewed down the b axis, successive columns are stacked in the opposite direction. The structure reported herein is the monoclinic polymorph of the previously reported orthorhombic form [Yi & Hu (2009. Acta Cryst. E65, o2643], in which the complete molecule is generated by a crystallographic twofold axis.

  16. Phase-controlled synthesis of polymorphic tungsten diphosphide with hybridization of monoclinic and orthorhombic phases as a novel electrocatalyst for efficient hydrogen evolution

    Science.gov (United States)

    Pi, Mingyu; Wu, Tianli; Guo, Weimeng; Wang, Xiaodeng; Zhang, Dingke; Wang, Shuxia; Chen, Shijian

    2017-05-01

    The design and development of high-efficiency and non-noble-metal hydrogen evolution reaction (HER) electrocatalysts for future clean and renewable energy system has excited significant research interests over the recent years. In this communication, the polymorphic tungsten diphosphide (p-WP2) nanoparticles with mixed monoclinic (α-) and orthorhombic (β-) phases are synthesized by phase-controlled phosphidation route via vacuum capsulation and explored as a novel efficient electrocatalyst towards HER. The p-WP2 catalyst delivers superior performance with excellent stability under both acidic and alkaline conditions over its single phases of α-WP2 and β-WP2. This finding demonstrates that a highly efficient hybrid electrocatalyst can be achieved via precise composition controlling and may open up exciting opportunities for their practical applications toward energy conversion.

  17. Stress-induced VO{sub 2} films with M2 monoclinic phase stable at room temperature grown by inductively coupled plasma-assisted reactive sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Okimura, Kunio; Watanabe, Tomo [School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Sakai, Joe [GREMAN, UMR 7347 CNRS, Universite Francois Rabelais de Tours, Parc de Grandmont 37200 Tours (France)

    2012-04-01

    We report on growth of VO{sub 2} films with M2 monoclinic phase stable at room temperature under atmospheric pressure. The films were grown on quartz glass and Si substrates by using an inductively coupled plasma-assisted reactive sputtering method. XRD-sin{sup 2}{Psi} measurements revealed that the films with M2 phase are under compressive stress in contrast to tensile stress of films with M1 phase. Scanning electron microscopy observations revealed characteristic crystal grain aspects with formation of periodical twin structure of M2 phase. Structural phase transition from M2 to tetragonal phases, accompanied by a resistance change, was confirmed to occur as the temperature rises. Growth of VO{sub 2} films composed of M2 phase crystalline is of strong interest for clarifying nature of Mott transition of strongly correlated materials.

  18. Comment on ``Monoclinic phase of PbZr0.52Ti0.48O3 ceramics: Raman and phenomenological thermodynamic studies''

    Science.gov (United States)

    Frantti, J.; Lappalainen, J.; Lantto, V.; Nishio, S.; Kakihana, M.

    2001-05-01

    Recently, Souza Filho et al. [A. G. Souza Filho, K. C. V. Lima, A. P. Ayala, I. Guedes, P. T. C. Freire, J. Mendes Filho, E. B. Araujo, and J. A. Eiras, Phys. Rev. B 61, 14 283 (2000)] reported a phase transition between monoclinic and tetragonal phases as a function of temperature in a PbZr0.52Ti0.48O3 ceramic sample, observed by Raman spectroscopy. We show that their observation has no relation to the phase transition and the anomaly they interpreted as an indication of a phase transition was due to the erroneous curve fit procedure, which predicts a clearly observable phase transition for all tetragonal lead-zirconate-titanate ceramics, including lead titanate. A more appropriate way to study this phase transition phenomena by Raman spectroscopy is discussed.

  19. Closure Report for Corrective Action Unit 116: Area 25 Test Cell C Facility, Nevada National Security Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2011-09-29

    This Closure Report (CR) presents information supporting closure of Corrective Action Unit (CAU) 116, Area 25 Test Cell C Facility. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; the U.S. Department of Energy (DOE), Environmental Management; the U.S. Department of Defense; and DOE, Legacy Management (FFACO, 1996 [as amended March 2010]). CAU 116 consists of the following two Corrective Action Sites (CASs), located in Area 25 of the Nevada National Security Site: (1) CAS 25-23-20, Nuclear Furnace Piping and (2) CAS 25-41-05, Test Cell C Facility. CAS 25-41-05 consisted of Building 3210 and the attached concrete shield wall. CAS 25-23-20 consisted of the nuclear furnace piping and tanks. Closure activities began in January 2007 and were completed in August 2011. Activities were conducted according to Revision 1 of the Streamlined Approach for Environmental Restoration Plan for CAU 116 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2008). This CR provides documentation supporting the completed corrective actions and provides data confirming that closure objectives for CAU 116 were met. Site characterization data and process knowledge indicated that surface areas were radiologically contaminated above release limits and that regulated and/or hazardous wastes were present in the facility.

  20. Study on Use of Fuel-Cell Auxiliary Power Units in Refrigerator Cars Employed for Delivery to Convenience Store

    Science.gov (United States)

    Katayama, Noboru; Kamiyama, Hideyuki; Kogoshi, Sumio; Kudo, Yusuke; Fukada, Takafumi; Ogawa, Makoto

    The use of fuel-cell auxiliary power units (FC-APU) in refrigerator cars employed delivery to for convenience store delivery has been studied. The delivery pattern is assumed to be a typical pattern that includes driving between convenience stores or between a delivery center and a convenience store, unloading, driver's lunch break. The M15 driving mode, which simulates the driving condition in urban areas, is used as the driving mode in the delivery pattern. The FC-APU system includes a proton-exchange membrane fuel cell (PEFC) module, an inverter, and DC/DC converter. Bench tests of the FC-APU are performed to determine the hydrogen fuel consumption rate and the energy efficiency; these values depend on the output power of the PEFC module. The calculated relationship between the output power and fuel consumption rate of a current used system, which consists of an alternator and a secondary battery, are used to estimate the energy efficiency of the current used system. On the basis of the measurement data in this study and the results for the model proposed by Brodric et al. [C. J. Brodrick et al., Trans. Res. D, vol 7, pp. 303 (2002)], the payback period is calculated. The results indicate that the payback period would be 2.1 years when the FC-APU operates at a load of 70%.

  1. Synchronization of stochastic Ca²(+) release units creates a rhythmic Ca²(+) clock in cardiac pacemaker cells.

    Science.gov (United States)

    Maltsev, Anna V; Maltsev, Victor A; Mikheev, Maxim; Maltseva, Larissa A; Sirenko, Syevda G; Lakatta, Edward G; Stern, Michael D

    2011-01-19

    In sinoatrial node cells of the heart, beating rate is controlled, in part, by local Ca²(+) releases (LCRs) from the sarcoplasmic reticulum, which couple to the action potential via electrogenic Na(+)/Ca²(+) exchange. We observed persisting, roughly periodic LCRs in depolarized rabbit sinoatrial node cells (SANCs). The features of these LCRs were reproduced by a numerical model consisting of a two-dimensional array of stochastic, diffusively coupled Ca²(+) release units (CRUs) with fixed refractory period. Because previous experimental studies showed that β-adrenergic receptor stimulation increases the rate of Ca²(+) release through each CRU (dubbed I(spark)), we explored the link between LCRs and I(spark) in our model. Increasing the CRU release current I(spark) facilitated Ca²(+)-induced-Ca²(+) release and local recruitment of neighboring CRUs to fire more synchronously. This resulted in a progression in simulated LCR size (from sparks to wavelets to global waves), LCR rhythmicity, and decrease of LCR period that parallels the changes observed experimentally with β-adrenergic receptor stimulation. The transition in LCR characteristics was steeply nonlinear over a narrow range of I(spark), resembling a phase transition. We conclude that the (partial) periodicity and rate regulation of the "Calcium clock" in SANCs are emergent properties of the diffusive coupling of an ensemble of interacting stochastic CRUs. The variation in LCR period and size with I(spark) is sufficient to account for β-adrenergic regulation of SANC beating rate.

  2. Electrical start-up for diesel fuel processing in a fuel-cell-based auxiliary power unit

    Science.gov (United States)

    Samsun, Remzi Can; Krupp, Carsten; Tschauder, Andreas; Peters, Ralf; Stolten, Detlef

    2016-01-01

    As auxiliary power units in trucks and aircraft, fuel cell systems with a diesel and kerosene reforming capacity offer the dual benefit of reduced emissions and fuel consumption. In order to be commercially viable, these systems require a quick start-up time with low energy input. In pursuit of this end, this paper reports an electrical start-up strategy for diesel fuel processing. A transient computational fluid dynamics model is developed to optimize the start-up procedure of the fuel processor in the 28 kWth power class. The temperature trend observed in the experiments is reproducible to a high degree of accuracy using a dual-cell approach in ANSYS Fluent. Starting from a basic strategy, different options are considered for accelerating system start-up. The start-up time is reduced from 22 min in the basic case to 9.5 min, at an energy consumption of 0.4 kW h. Furthermore, an electrical wire is installed in the reformer to test the steam generation during start-up. The experimental results reveal that the generation of steam at 450 °C is possible within seconds after water addition to the reformer. As a result, the fuel processor can be started in autothermal reformer mode using the electrical concept developed in this work.

  3. Study of serum ferritin in donors of two red blood cells units collected by apheresis.

    Science.gov (United States)

    González, Maria Luz Dobao; Maia, Salome; Mesquita, Paula; Bessa, Milena

    2013-10-01

    To analyze the recovery of iron stores without supplementation, when keeping an interval of six months between donations. From April 2007 to May 2011, 308 regular and voluntary donors were selected. The apheresis collections were performed using ALYX® Component Collection System-Fenwal™. The hematological parameters were analyzed using the Cell DIN Sapphire - Abbot Diagnostics, and the serum ferritin by sandwich immunoassay method with fluorescence detection in final phase (ELFA) - Vidas® Ferritin-Biomérieux SA. A descriptive statistical analysis was performed for each hematological parameters and serum ferritin. The median hemoglobin concentration was 15.6g/dL (14, 18.4) in the first procedure and remains constant at subsequent donations. The ferritin median concentration was 64.6 μg/L (7.2, 886). A decrease of 15.6% was observed when compared the first to the second procedure with a median 54.6 μg/L (8.3, 213.7). Paradoxically, this decrease is not evident in the subsequent procedures, where an increase of 14.6% and 3.4% for the third and fourth procedure respectively was observed. Changes in ferritin values show statistically significant differences between the first and second collection, but this difference disappeared in subsequent donations. The analysis of MCH in each collection indicates that the significant difference between first and second donation (p1-2ferritin found between procedures and the beginning of the stabilization of ferritin levels. The determination of ferritin appears not to be the most important parameter to consider at the time of donor selection and suggests that other factors unrelated to the donation may play a significant role. A decrease in serum ferritin was observed at the beginning, but it seems to attend a recovery and stabilization in the successive procedures. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Prophylaxis with levofloxacin: impact on bacterial susceptibility and epidemiology in a hematopoietic stem cell transplant unit

    Directory of Open Access Journals (Sweden)

    Livia Amaral Alonso Lopes

    2014-01-01

    Full Text Available Background: The emergence of resistance has been demonstrated in cancer treatment centers where prophylaxis with fluoroquinolone is used. Objective: Considering the importance of epidemiological monitoring as a strategy in choosing protocols involving antibiotics, this study aimed to evaluate the emergence of quinolone resistance and changes in the local epidemiology in a hematopoietic stem cell transplant service. Methods: For this study, 60 positive cultures before the prophylactic use of levofloxacin (period A: 2007-2008 and 118 cultures after starting the use of prophylactic levofloxacin (period B: 2010-2011 were evaluated. Results: Resistance increased for all the different types of bacteria isolated (from 46.0% to 76.5%; p-value = 0.0002. Among Gram-negative bacteria, resistance increased from 21.4% to 60.7% (p-value = 0.0163 and among Gram-positive bacteria, it increased from 55.6% to 82.9% (p-value = 0.0025. The use of levofloxacin increased from 19.44 defined daily doses per 1,000 patient-days in period A to 166.64 in period B. The use of broad spectrum antibiotics remained unchanged. Considering bacteria associated with infection, 72 and 76 were isolated in periods A and B, respectively. There was a reduction in the rate of Gramnegative bacteria in cultures associated with infection (3.81 vs. 2.00 cultures/1,000 patientdays; p-value = 0.008. Conclusion: The study of prophylaxis with levofloxacin demonstrated that there was a decrease in infections by Gram-negative bacteria; however, bacterial resistance increased, even though the use of broad-spectrum antibiotics remained unchanged. Constant monitoring of local epidemiology combined with research on clinical outcomes is needed to evaluate the effectiveness of prophylaxis.

  5. Off-resonance effects in (14)N NQR signals from the pulsed spin-locking (PSL) and three-pulse echo sequence; a study for monoclinic TNT.

    Science.gov (United States)

    Smith, John A S; Rowe, Michael D; Althoefer, Kaspar; Peirson, Neil F; Barras, Jamie

    2015-10-01

    In NQR detection applications signal averaging by the summation of rapidly regenerated signals from multiple pulse sequences of the pulsed spin-locking (PSL) type is often used to improve sensitivity. It is important to characterise and if possible minimise PSL sequence off-resonance effects since they can make it difficult to optimise detection performance. We illustrate this with measurements of the variation of the decay time T2e and the amplitude of PSL signal trains with pulse spacing and excitation offset frequency for the 870 kHz ν+(14)N NQR line of monoclinic TNT under carefully stabilised temperature conditions. We have also carried out a similar study of signals from monoclinic TNT and 1H-1,2,3-triazole generated by a three-pulse echo sequence and the results are shown to agree well with a theoretical treatment appropriate to polycrystalline NQR samples such as TNT for which spin I=1, asymmetry parameter η≠0 and T1≫T2. Based on this theory we derive simple models for calculating TNT PSL signal trains and hence the pulse spacing and off-resonance dependence of signal amplitude and T2e which we compare to our experimental data. We discuss the influence of PSL echo summation on off-resonance effects in detected signal intensity and show how a phase-alternated multiple pulse sequence can be used in combination with the PSL sequence to eliminate variation in detection performance due to off-resonance effects.

  6. First-principles investigation of the effect of charged unit cell on the electronic structure of two-dimensional MoS2

    Science.gov (United States)

    Shekaari, Ashkan; Abolhassani, Mohammad Reza; Lashgari, Hamed

    2017-01-01

    Density-functional theory has been applied to investigate the effect of charged unit cell on the structural and electronic properties of two-dimensional MoS2 within PBE-GGA. The charge of the unit cell of the monolayer changes from zero to n = ± 4 e with e the absolute value of the elementary electric charge. Variations of the lattice constant, Mo-S bond length, S-Mo-S bond angle, total energy, exchange and correlation contributions, and the Fermi level versus n have been calculated quantitatively, indicating decrease in the stability of the atomic structure of the monolayer with increase in the absolute value of n. It is found that the Fermi level for two-dimensional MoS2 is a function of both the number of electrons in allowed states and the inverse of the volume of the unit cell. The electronic properties of each monolayer have been also calculated via examining the related electronic band structure and density of states. Results broadly support the view that the effect of charged unit cell (n =+ e to - 4 e) on the electronic properties of MoS2 monolayer is manifested in the form of semiconductor-to-metal transition in addition to the Fermi level shift. It is also verified that as the negative charge of the unit cell increases from n = - e to - 4 e , there is an ever-increasing trend in the total number of allowed electronic states at the Fermi level, implying a direct correlation between electrical conductivity and the value of n in a way that the more negative the charge of the unit cell, the higher the electrical conductivity of the monolayer.

  7. Unit Cell Analysis of the Superelastic Behavior of Open-Cell Tetrakaidecahedral Shape Memory Alloy Foam under Quasi-Static Loading

    Directory of Open Access Journals (Sweden)

    Guillaume Maîtrejean

    2014-01-01

    Full Text Available Cellular solid materials and, more specifically, foams are increasingly common in many industrial applications due to their attractive characteristics. The tetrakaidecahedral foam microstructure, which can be observed in many types of foams, is studied in the present work in association with shape memory alloys (SMA material. SMA foams are of particular interest as they associate both the shape memory effect and the superelasticity with the characteristics of foam. A Unit Cell Finite Element Method approach is used, an approach that allows accurate predicting of the macroscale response of the foam with a highly reduced numerical effort. The tetrakaidecahedral foam’s responses, both in the elastic and in the superelastic stages, are then extracted and compared with results from the literature. The tetrakaidecahedral geometry is found to be of particular interest when associated with SMA as it takes more advantage of the superelastic property of the material than foams with randomly distributed porosity.

  8. Effect of growth mechanisms on the deformation of a unit cell and polarization reversal in barium-strontium titanate heterostructures on magnesium oxide

    Science.gov (United States)

    Mukhortov, V. M.; Golovko, Yu. I.; Biryukov, S. V.; Anokhin, A.; Yuzyuk, Yu. I.

    2016-01-01

    The effect of a growth mechanism on the unit cell strain and the related change in the properties of single-crystal Ba0.8Sr0.2TiO3 films grown on MgO substrates according to the Frank-van der Merwe and Volmer-Weber growth mechanisms is studied. The unit cell strain is shown to depend substantially on the film thickness and the growth mechanism. It is found that the same film-substrate pair can be used to vary stresses in the film from two-dimensional tensile to compressive stresses due to a change in the growth mechanism and the film thickness.

  9. Ammonia concentration and bacterial evaluation of feline whole blood and packed red blood cell units stored for transfusion

    OpenAIRE

    Eva Spada; Daniela Proverbio; Piera Anna Martino; Luciana Baggiani; Roberta Perego; Nora Roggero

    2014-01-01

    Ammonia concentrations increase in human, canine and equine WB and PRBC units during storage. The aim of this study was to determine the effect of storage on ammonia concentration in feline WB and PRBC units stored in a veterinary blood bank and to evaluate possible correlations with bacterial contamination. Ammonia concentration was evaluated in 15 WB units and 2 PRBC units on day 1 and at the end of storage after 35 and 42 days, respectively. In an additional 5 WB units and 4 PRBC units amm...

  10. Investigation of the Start-up Strategy for a Solid Oxide Fuel Cell Based Auxiliary Power Unit under Transient Conditions

    Directory of Open Access Journals (Sweden)

    Michael R. von Spakovsky

    2005-06-01

    Full Text Available

    A typical approach to the synthesis/design optimization of energy systems is to only use steady state operation and high efficiency (or low total life cycle cost at full load as the basis for the synthesis/design. Transient operation as reflected by changes in power demand, shut-down, and start-up are left as secondary tasks to be solved by system and control engineers once the synthesis/design is fixed. However, start-up and shut-down may be events that happen quite often and, thus, may be quite important in the creative process of developing the system. This is especially true for small power units used in transportation applications or for domestic energy supplies, where the load demand changes frequently and peaks in load of short duration are common. The duration of start-up is, of course, a major factor which must be considered since rapid system response is an important factor in determining the feasibility of solid oxide fuel cell (SOFC based auxiliary power units (APUs. Start-up and shut-down may also significantly affect the life span of the system due to thermal stresses on all system components. Therefore, a proper balance must be struck between a fast response and the costs of owning and operating the system so that start-up or any other transient process can be accomplished in as short a time as possible yet with a minimum in fuel consumption.

    In this research work we have been studying the effects of control laws and strategies and transients on system performance. The results presented in this paper are based on a set of transient models developed and implemented for the components of a 5 kWe net power SOFC based APU and for the high-fidelity system which results from their integration. The simulation results given below are for two different start-up approaches: one with steam recirculation and component pre-heating and the second without either. These start-up simulations were performed for fixed values of a number of

  11. Closure Report for Corrective Action Unit 261: Area 25 Test Cell A Leachfield System, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    T. M. Fitzmaurice

    2001-04-01

    The purpose of this Closure Report (CR) is to provide documentation of the completed corrective action at the Test Cell A Leachfield System and to provide data confirming the corrective action. The Test Cell A Leachfield System is identified in the Federal Facility Agreement and Consent Order (FFACO) of 1996 as Corrective Action Unit (CAU) 261. Remediation of CAU 261 is required under the FFACO (1996). CAU 261 is located in Area 25 of the Nevada Test Site (NTS) which is approximately 140 kilometers (87 miles) northwest of Las Vegas, Nevada (Figure 1). CAU 261 consists of two Corrective Action Sites (CASS): CAS 25-05-01, Leachfield; and CAS 25-05-07, Acid Waste Leach Pit (AWLP) (Figures 2 and 3). Test Cell A was operated during the 1960s and 1970s to support the Nuclear Rocket Development Station. Various operations within Building 3124 at Test Cell A resulted in liquid waste releases to the Leachfield and the AWLP. The following existing site conditions were reported in the Corrective Action Decision Document (CADD) (U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1999): Soil in the leachfield was found to exceed the Nevada Division of Environmental Protection (NDEP) Action Level for petroleum hydrocarbons, the U.S. Environmental Protection Agency (EPA) preliminary remediation goals for semi volatile organic compounds, and background concentrations for strontium-90; Soil below the sewer pipe and approximately 4.5 meters (m) (15 feet [ft]) downstream of the initial outfall was found to exceed background concentrations for cesium-137 and strontium-90; Sludge in the leachfield septic tank was found to exceed the NDEP Action Level for petroleum hydrocarbons and to contain americium-241, cesium-137, uranium-234, uranium-238, potassium-40, and strontium-90; No constituents of concern (COC) were identified at the AWLP. The NDEP-approved CADD (DOWNV, 1999) recommended Corrective Action Alternative 2, ''Closure of the Septic Tank and Distribution Box

  12. Single-unit-cell layer established Bi 2 WO 6 3D hierarchical architectures: Efficient adsorption, photocatalysis and dye-sensitized photoelectrochemical performance

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hongwei; Cao, Ranran; Yu, Shixin; Xu, Kang; Hao, Weichang; Wang, Yonggang; Dong, Fan; Zhang, Tierui; Zhang, Yihe

    2017-12-01

    Single-layer catalysis sparks huge interests and gains widespread attention owing to its high activity. Simultaneously, three-dimensional (3D) hierarchical structure can afford large surface area and abundant reactive sites, contributing to high efficiency. Herein, we report an absorbing single-unit-cell layer established Bi2WO6 3D hierarchical architecture fabricated by a sodium dodecyl benzene sulfonate (SDBS)-assisted assembled strategy. The DBS- long chains can adsorb on the (Bi2O2)2+ layers and hence impede stacking of the layers, resulting in the single-unit-cell layer. We also uncovered that SDS with a shorter chain is less effective than SDBS. Due to the sufficient exposure of surface O atoms, single-unit-cell layer 3D Bi2WO6 shows strong selectivity for adsorption on multiform organic dyes with different charges. Remarkably, the single-unit-cell layer 3D Bi2WO6 casts profoundly enhanced photodegradation activity and especially a superior photocatalytic H2 evolution rate, which is 14-fold increase in contrast to the bulk Bi2WO6. Systematic photoelectrochemical characterizations disclose that the substantially elevated carrier density and charge separation efficiency take responsibility for the strengthened photocatalytic performance. Additionally, the possibility of single-unit-cell layer 3D Bi2WO6 as dye-sensitized solar cells (DSSC) has also been attempted and it was manifested to be a promising dye-sensitized photoanode for oxygen evolution reaction (ORR). Our work not only furnish an insight into designing single-layer assembled 3D hierarchical architecture, but also offer a multi-functional material for environmental and energy applications.

  13. Inter-relationships between single carbon units' metabolism and resting energy expenditure in weight-losing patients with small cell lung cancer. Effects of methionine supply and chemotherapy

    DEFF Research Database (Denmark)

    Sengeløv, H; Hansen, O P; Simonsen, L

    1994-01-01

    The one-carbon unit metabolism was investigated in 8 weight-losing patients with small cell carcinoma of the lung (SCLC). At diagnosis, 6 of the 8 patients had elevated formiminoglutamic acid (FIGLU) excretion after a histidine load, suggesting a lack of one-carbon units. In accordance, a signifi......The one-carbon unit metabolism was investigated in 8 weight-losing patients with small cell carcinoma of the lung (SCLC). At diagnosis, 6 of the 8 patients had elevated formiminoglutamic acid (FIGLU) excretion after a histidine load, suggesting a lack of one-carbon units. In accordance...... pretreatment FIGLU excretion and REE, although the REE measured in this group of patients was within the normal range. These data demonstrate an increased demand of "active" one-carbon units in energy consumption in a group of weight-losing cancer patients. The one-carbon unit deficit was reconditioned by oral......, a significant decrease of FIGLU excretion was observed in the patients after oral administration of DL-methionine for 4 days. The elevated FIGLU excretion was positively correlated to weight loss prior to diagnosis and negatively correlated to serum albumin at time of diagnosis. After 3 months of combination...

  14. Acute kidney injury in patients with systemic sclerosis participating in hematopoietic cell transplantation trials in the United States.

    Science.gov (United States)

    Hosing, Chitra; Nash, Richard; McSweeney, Peter; Mineishi, Shin; Seibold, James; Griffith, Linda M; Shulman, Howard; Goldmuntz, Ellen; Mayes, Maureen; Parikh, Chirag R; Crofford, Leslie; Keyes-Elstein, Lynette; Furst, Daniel; Steen, Virginia; Sullivan, Keith M

    2011-05-01

    Recipients of hematopoietic cell transplantation may be at risk for developing acute kidney injury (AKI), and this risk may be increased in patients who undergo transplantation for severe systemic sclerosis (SSc) due to underlying scleroderma renal disease. AKI after transplantation can increase treatment-related mortality. To better define these risks, we analyzed 91 patients with SSc who were enrolled in 3 clinical trials in the United States of autologous or allogeneic hematopoietic cell transplantation (HCT). Eleven (12%) of the 91 patients with SSc in these studies (8 undergoing autologous HCT, 1 undergoing allogeneic HCT, 1 pretransplantation, 1 given i.v. cyclophosphamide on a transplantation trial) experienced AKI, of whom 8 required dialysis and/or therapeutic plasma exchange. AKI injury in the 9 HCT recipients developed a median of 35 days (range, 0-90 days) after transplantation. Ten of 11 patients with AKI received angiotensin-converting enzyme inhibitor (ACE-I) therapy. The etiology of AKI was attributed to scleroderma renal crisis in 6 patients (including 2 with normotensive renal crisis), to AKI of uncertain etiology in 2 patients, and to AKI superimposed on scleroderma kidney disease in 3 patients. Eight of the 11 patients died, one each because of progression of SSc, multiorgan failure, gastrointestinal and pulmonary bleeding, pericardial tamponade and pulmonary complications, diffuse alveolar hemorrhage, pulmonary embolism, graft-versus-host disease, and malignancy. Limiting nephrotoxins, cautious use of corticosteroids, renal shielding during total body irradiation, strict control of blood pressure, and aggressive use of ACE-Is may be of importance in preventing renal complications after HCT for SSc.

  15. Effects of the Scientific Argumentation Based Learning Process on Teaching the Unit of Cell Division and Inheritance to Eighth Grade Students

    Science.gov (United States)

    Balci, Ceyda; Yenice, Nilgun

    2016-01-01

    The aim of this study is to analyse the effects of scientific argumentation based learning process on the eighth grade students' achievement in the unit of "cell division and inheritance". It also deals with the effects of this process on their comprehension about the nature of scientific knowledge, their willingness to take part in…

  16. Convergent synthesis of a tetrasaccharide repeating unit of the O-specific polysaccharide from the cell wall lipopolysaccharide of Azospirillum brasilense strain Sp7

    Directory of Open Access Journals (Sweden)

    Pintu Kumar Mandal

    2014-01-01

    Full Text Available A straightforward convergent synthesis has been carried out for the tetrasaccharide repeating unit of the O-specific cell wall lipopolysaccharide of the strain Sp7 of Azospirillum brasilense. The target tetrasaccharide has been synthesized from suitably protected monosaccharide intermediates in 42% overall yield in seven steps by using a [2 + 2] block glycosylation approach.

  17. Impact of the oxygen defects and the hydrogen concentration on the surface of tetragonal and monoclinic ZrO2 on the reduction rates of stearic acid on Ni/ZrO2

    Energy Technology Data Exchange (ETDEWEB)

    Foraita, Sebastian D.; Fulton, John L.; Chase, Zizwe A.; Vjunov, Aleksei; Xu, Pinghong; Barath, Eszter; Camaioni, Donald M.; Zhao, Chen; Lercher, Johannes A.

    2015-02-02

    The effect of the physicochemical properties of ZrO2 phases on the activity of Ni/ZrO2 catalysts for hydrodeoxygenation of stearic acid are described. A synergistic interaction between Ni and ZrO2 support was found. The effect is greatest for the monoclinic phase of ZrO2.

  18. Growth of Casting Microcrack and Micropore in Single-crystal Superalloys Analysed by Three-Dimensional Unit Cell

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Finite element (FE) analysis was employed to investigate the casting microcrack and micropore growth in nickel-base single-crystal superalloys DD3. Based on the finite deformation rate-dependent crystallographic constitutive equation, the simulations of casting microcrack and micropore growth in three-dimensional unit cell model were carried out in a range of parameters including stress triaxiality, Lode parameter and type of activated slip systems. The FE results show that the stress triaxiality has profound effects on growth behavior,and the Lode parameter is also important for the casting microcrack and micropore growth. The type of operative slip systems has remarkable effect on casting microcrack and micropore growth, so the life of singlecrystal component is associated with the type of activated slip systems, which is related to Schmid factor and the number of activated slip systems. The growth comparison between microcrack and micropore reveals that when the material is subjected to large deformation, the growth rate of microcrack is faster than that of micropore, i.e. microcrack is more dangerous than micropore; the microcrack is easier to result in brittle fracture than micropore. The stress triaxiality and Lode parameter have strong influence on the growth of microcrack and micropore.

  19. Invasive fungal infection among hematopoietic stem cell transplantation patients with mechanical ventilation in the intensive care unit

    Directory of Open Access Journals (Sweden)

    Hung Chen-Yiu

    2012-02-01

    Full Text Available Abstract Background Invasive fungal infection (IFI is associated with high morbidity and high mortality in hematopoietic stem cell transplantation (HSCT patientsThe purpose of this study was to assess the characteristics and outcomes of HSCT patients with IFIs who are undergoing MV at a single institution in Taiwan. Methods We performed an observational retrospective analysis of IFIs in HSCT patients undergoing mechanical ventilation (MV in an intensive care unit (ICU from the year 2000 to 2009. The characteristics of these HSCT patients and risk factors related to IFIs were evaluated. The status of discharge, length of ICU stay, date of death and cause of death were also recorded. Results There were 326 HSCT patients at the Linkou Chang-Gung Memorial Hospital (Taipei, Taiwan during the study period. Sixty of these patients (18% were transferred to the ICU and placed on mechanical ventilators. A total of 20 of these 60 patients (33% had IFIs. Multivariate analysis indicated that independent risk factors for IFI were admission to an ICU more than 40 days after HSCT, graft versus host disease (GVHD, and high dose corticosteroid (p p = 0.676. Conclusion There was a high incidence of IFIs in HSCT patients requiring MV in the ICU in our study cohort. The independent risk factors for IFI are ICU admission more than 40 days after HSCT, GVHD, and use of high-dose corticosteroid.

  20. Outcome of Recipients of Hematopoietic Stem Cell Transplants Who Require Intensive Care Unit Support: A Single Institution Experience.

    Science.gov (United States)

    Galindo-Becerra, Samantha; Labastida-Mercado, Nancy; Rosales-Padrón, Jaime; García-Chavez, Jessica; Soto-Vega, Elena; Rivadeneyra-Espinoza, Liliana; León-Peña, Andres A; Fernández-Lara, Danitza; Dominguez-Cid, Monica; Anthon-Méndez, Javier; Arizpe-Bravo, Daniel; Ruiz-Delgado, Guillermo J; Ruiz-Argüelles, Guillermo J

    2015-01-01

    Admission to the intensive care unit (ICU) of a patient who has been grafted with hematopoietic stem cells is a serious event, but the role of the ICU in this setting remains controversial. Data were analyzed from patients who underwent autologous or allogeneic bone marrow transplantation at the Centro de Hematología y Medicina Interna de Puebla, México, between May 1993 and October 2014. In total, 339 patients were grafted: 150 autografts and 189 allografts; 68 of the grafted patients (20%) were admitted to the ICU after transplantation: 27% of the allografted and 11% of the autografted patients (p = 0.2). Two of 17 autografted patients (12%) and 5 of 51 allografted patients (10%) survived. All patients who required insertion of an endotracheal tube died, whereas 7 of 11 patients without invasive mechanical ventilation survived (p = 0.001). Only 10% of the grafted patients survived their stay in the ICU; this figure is lower than those reported from other centers and may reflect several facts, varying from the quality of the ICU support to ICU admission criteria to the initial management of all the grafts in an outpatient setting, which could somehow delay the arrival of patients to the hospital. © 2015 S. Karger AG, Basel.

  1. Compact Design of 10 kW Proton Exchange Membrane Fuel Cell Stack Systems with Microcontroller Units

    Directory of Open Access Journals (Sweden)

    Hsiaokang Ma

    2014-04-01

    Full Text Available In this study, fuel, oxidant supply and cooling systems with microcontroller units (MCU are developed in a compact design to fit two 5 kW proton exchange membrane fuel cell (PEMFC stacks. At the initial stage, the testing facility of the system has a large volume (2.0 m × 2.0 m × 1.5 m with a longer pipeline and excessive control sensors for safe testing. After recognizing the performance and stability of stack, the system is redesigned to fit in a limited space (0.4 m × 0.5 m × 0.8 m. Furthermore, the stack performance is studied under different hydrogen recycling modes. Then, two similar 5 kW stacks are directly coupled with diodes to obtain a higher power output and safe operation. The result shows that the efficiency of the 5 kW stack is 43.46% with a purge period of 2 min with hydrogen recycling and that the hydrogen utilization rate µf is 66.31%. In addition, the maximum power output of the twin-coupled module (a power module with two stacks in electrical cascade/parallel arrangement is 9.52 kW.

  2. Phase coexistence calculations via a unit-cell Gibbs ensemble formalism for melts of reversibly bonded block copolymers

    Science.gov (United States)

    Mester, Zoltan; Lynd, Nathaniel; Fredrickson, Glenn

    2013-03-01

    Melts of block copolymer blends can exhibit coexistence between compositionally and morphologically distinct phases. We derived a unit-cell approach for a field theoretic Gibbs ensemble formalism to rapidly map out such coexistence regions. We also developed a canonical ensemble model for the reversible reaction of supramolecular polymers and integrated it into the Gibbs ensemble scheme. This creates a faster method for generating phase diagrams in complex supramolecular systems than the usual grand canonical ensemble method and allows us to specify the system in experimentally accessible volume fractions rather than chemical potentials. The integrated approach is used to calculate phase diagrams for AB diblock copolymers reversibly reacting with B homopolymers to form a new diblocks we term ``ABB.'' For our case, we use a diblock that is sixty percent A monomer and a homopolymer that is the same length as the diblock. In the limits of infinite reaction favorability (large equilibrium constant), the system approaches cases of an ABB diblock-B homopolymer blend when the AB diblock is the limiting reactant and AB diblock-ABB diblock blend when the homopolymer is the limiting reactant. As reaction favorability is decreased, the phase boundaries shift towards higher homopolymer compositions so that sufficient reaction can take place to produce the ABB diblock that has a deciding role stabilizing the observed phases.

  3. Torque and atomic forces for Cartesian tensor atomic multipoles with an application to crystal unit cell optimization.

    Science.gov (United States)

    Elking, Dennis M

    2016-08-15

    New equations for torque and atomic force are derived for use in flexible molecule force fields with atomic multipoles. The expressions are based on Cartesian tensors with arbitrary multipole rank. The standard method for rotating Cartesian tensor multipoles and calculating torque is to first represent the tensor with n indexes and 3(n) redundant components. In this work, new expressions for directly rotating the unique (n + 1)(n + 2)/2 Cartesian tensor multipole components Θpqr are given by introducing Cartesian tensor rotation matrix elements X(R). A polynomial expression and a recursion relation for X(R) are derived. For comparison, the analogous rotation matrix for spherical tensor multipoles are the Wigner functions D(R). The expressions for X(R) are used to derive simple equations for torque and atomic force. The torque and atomic force equations are applied to the geometry optimization of small molecule crystal unit cells. In addition, a discussion of computational efficiency as a function of increasing multipole rank is given for Cartesian tensors. © 2016 Wiley Periodicals, Inc.

  4. Corrective Action Plan for Corrective Action Unit 261: Area 25 Test Cell A Leachfield System, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    T. M. Fitzmaurice

    2000-08-01

    This Corrective Action Plan (CAP) has been prepared for the Corrective Action Unit (CAU)261 Area 25 Test Cell A Leachfield System in accordance with the Federal Facility and Consent Order (Nevada Division of Environmental Protection [NDEP] et al., 1996). This CAP provides the methodology for implementing the approved corrective action alternative as listed in the Corrective Action Decision Document (U.S. Department of Energy, Nevada Operations Office, 1999). Investigation of CAU 261 was conducted from February through May of 1999. There were no Constituents of Concern (COCs) identified at Corrective Action Site (CAS) 25-05-07 Acid Waste Leach Pit (AWLP). COCs identified at CAS 25-05-01 included diesel-range organics and radionuclides. The following closure actions will be implemented under this plan: Because COCs were not found at CAS 25-05-07 AWLP, no action is required; Removal of septage from the septic tank (CAS 25-05-01), the distribution box and the septic tank will be filled with grout; Removal of impacted soils identified near the initial outfall area; and Upon completion of this closure activity and approval of the Closure Report by NDEP, administrative controls, use restrictions, and site postings will be used to prevent intrusive activities at the site.

  5. Novel web-based real-time dashboard to optimize recycling and use of red cell units at a large multi-site transfusion service

    Directory of Open Access Journals (Sweden)

    Christopher Sharpe

    2014-01-01

    Full Text Available Background: Effective blood inventory management reduces outdates of blood products. Multiple strategies have been employed to reduce the rate of red blood cell (RBC unit outdate. We designed an automated real-time web-based dashboard interfaced with our laboratory information system to effectively recycle red cell units. The objective of our approach is to decrease RBC outdate rates within our transfusion service. Methods: The dashboard was deployed in August 2011 and is accessed by a shortcut that was placed on the desktops of all blood transfusion services computers in the Capital District Health Authority region. It was designed to refresh automatically every 10 min. The dashboard provides all vital information on RBC units, and implemented a color coding scheme to indicate an RBC unit′s proximity to expiration. Results: The overall RBC unit outdate rate in the 7 months period following implementation of the dashboard (September 2011-March 2012 was 1.24% (123 units outdated/9763 units received, compared to similar periods in 2010-2011 and 2009-2010: 2.03% (188/9395 and 2.81% (261/9220, respectively. The odds ratio of a RBC unit outdate postdashboard (2011-2012 compared with 2010-2011 was 0.625 (95% confidence interval: 0.497-0.786; P < 0.0001. Conclusion: Our dashboard system is an inexpensive and novel blood inventory management system which was associated with a significant reduction in RBC unit outdate rates at our institution over a period of 7 months. This system, or components of it, could be a useful addition to existing RBC management systems at other institutions.

  6. Herd management and social variables associated with bulk tank somatic cell count in dairy herds in the eastern United States.

    Science.gov (United States)

    Schewe, R L; Kayitsinga, J; Contreras, G A; Odom, C; Coats, W A; Durst, P; Hovingh, E P; Martinez, R O; Mobley, R; Moore, S; Erskine, R J

    2015-11-01

    The ability to reduce somatic cell counts (SCC) and improve milk quality depends on the effective and consistent application of established mastitis control practices. The US dairy industry continues to rely more on nonfamily labor to perform critical tasks to maintain milk quality. Thus, it is important to understand dairy producer attitudes and beliefs relative to management practices, as well as employee performance, to advance milk quality within the changing structure of the dairy industry. To assess the adoption rate of mastitis control practices in United States dairy herds, as well as assess social variables, including attitudes toward employees relative to mastitis control, a survey was sent to 1,700 dairy farms in Michigan, Pennsylvania, and Florida in January and February of 2013. The survey included questions related to 7 major areas: sociodemographics and farm characteristics, milking proficiency, milking systems, cow environment, infected cow monitoring and treatment, farm labor, and attitudes toward mastitis and related antimicrobial use. The overall response rate was 41% (21% in Florida, 39% in Michigan, and 45% in Pennsylvania). Herd size ranged from 9 to 5,800 cows. Self-reported 3-mo geometric mean bulk tank SCC (BTSCC) for all states was 194,000 cells/mL. Multivariate analysis determined that proven mastitis control practices such as the use of internal teat sealants and blanket dry cow therapy, and not using water during udder preparation before milking, were associated with lower BTSCC. Additionally, farmer and manager beliefs and attitudes, including the perception of mastitis problems and the threshold of concern if BTSCC is above 300,000 cells/mL, were associated with BTSCC. Ensuring strict compliance with milking protocols, giving employees a financial or other penalty if BTSCC increased, and a perceived importance of reducing labor costs were negatively associated with BTSCC in farms with nonfamily employees. These findings highlight the

  7. Silicon Nanowire/Polymer Hybrid Solar Cell-Supercapacitor: A Self-Charging Power Unit with a Total Efficiency of 10.5.

    Science.gov (United States)

    Liu, Ruiyuan; Wang, Jie; Sun, Teng; Wang, Mingjun; Wu, Changsheng; Zou, Haiyang; Song, Tao; Zhang, Xiaohong; Lee, Shuit-Tong; Wang, Zhong Lin; Sun, Baoquan

    2017-07-12

    An integrated self-charging power unit, combining a hybrid silicon nanowire/polymer heterojunction solar cell with a polypyrrole-based supercapacitor, has been demonstrated to simultaneously harvest solar energy and store it. By efficiency enhancement of the hybrid nanowire solar cells and a dual-functional titanium film serving as conjunct electrode of the solar cell and supercapacitor, the integrated system is able to yield a total photoelectric conversion to storage efficiency of 10.5%, which is the record value in all the integrated solar energy conversion and storage system. This system may not only serve as a buffer that diminishes the solar power fluctuations from light intensity, but also pave its way toward cost-effective high efficiency self-charging power unit. Finally, an integrated device based on ultrathin Si substrate is demonstrated to expand its feasibility and potential application in flexible energy conversion and storage devices.

  8. Solvent effect in monoclinic to hexagonal phase transformation in LaPO{sub 4}:RE (RE=Dy{sup 3+}, Sm{sup 3+}) nanoparticles: Photoluminescence study

    Energy Technology Data Exchange (ETDEWEB)

    Phaomei, Ganngam [Department of Chemistry, Manipur University, Manipur 795003 (India); Rameshwor Singh, W., E-mail: dr.rmsingh@yahoo.co.i [Department of Chemistry, Manipur University, Manipur 795003 (India); Ningthoujam, R.S., E-mail: rsn@barc.gov.i [Chemistry Division, Bhabha Atomic Research Center, Mumbai 400085 (India)

    2011-06-15

    Nanosized phosphor materials, LaPO{sub 4}:RE (RE=Dy{sup 3+}, Sm{sup 3+}) have been synthesized using water, dimethyl sulfoxide (DMSO), ethylene glycol (EG) and mixed solvents at a relatively low temperature of 150 {sup o}C. X-ray diffraction (XRD) study reveals that as-prepared nanoparticles prepared in DMSO and EG are well crystalline and correspond to monoclinic phase. In the mixed water-DMSO or water-EG solvents, XRD patterns are in good agreement with hexagonal phase, but transformed to monoclinic phase at higher temperature of 900 {sup o}C. TEM images show well-dispersed and rice-shaped nanoparticles of diameter 5-10 nm, length of 13-37 nm for Dy{sup 3+}-doped LaPO{sub 4} and diameter of 25-35 nm, length of 73-82 nm for Sm{sup 3+}-doped LaPO{sub 4}. Dy{sup 3+}-doped LaPO{sub 4} shows two prominent emission peaks at 480 and 572 nm corresponding to {sup 4}F{sub 9/2}{yields}{sup 6}H{sub 15/2} (magnetic dipole) and {sup 4}F{sub 9/2}{yields}{sup 6}H{sub 13/2} (electric dipole) transitions, respectively. Similarly, for Sm{sup 3+}-doped LaPO{sub 4}, three prominent emission peaks at 561, 597 and 641 nm were observed corresponding to {sup 4}G{sub 5/2}{yields}{sup 6}H{sub 5/2}, {sup 4}G{sub 5/2}{yields}{sup 6}H{sub 7/2} (magnetic dipole) and {sup 4}G{sub 5/2}{yields}{sup 6}H{sub 9/2} (electric dipole) transitions, respectively. The luminescence intensity of the sample prepared in EG is more than that of DMSO or mixed solvents. Enhancement of luminescence is also observed after heat-treatment at 900 {sup o}C due to removal of quencher such as water, organic moiety and surface defects/dangling bonds. The samples are re-dispersible in polar solvent and can be incorporated in polymer film. - Research highlights: Nanomaterials. Optical properties. Luminescence materials.

  9. Crystal structure of monoclinic samarium and cubic europium sesquioxides and bound coherent neutron scattering lengths of the isotopes {sup 154}Sm and {sup 153}Eu

    Energy Technology Data Exchange (ETDEWEB)

    Kohlmann, Holger [Leipzig Univ. (Germany). Inst. of Inorganic Chemistry; Hein, Christina; Kautenburger, Ralf [Saarland Univ., Saarbruecken (Germany). Inorganic Solid State Chemistry; Hansen, Thomas C.; Ritter, Clemens [Institut Laue-Langevin, Grenoble (France); Doyle, Stephen [Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen (Germany). Inst. for Synchrotron Radiation (ISS)

    2016-11-01

    The crystal structures of monoclinic samarium and cubic europium sesquioxide, Sm{sub 2}O{sub 3} and Eu{sub 2}O{sub 3}, were reinvestigated by powder diffraction methods (laboratory X-ray, synchrotron, neutron). Rietveld analysis yields more precise structural parameters than previously known, especially for oxygen atoms. Interatomic distances d(Sm-O) in Sm{sub 2}O{sub 3} range from 226.3(4) to 275.9(2) pm [average 241.6(3) pm] for the monoclinic B type Sm{sub 2}O{sub 3} [space group C2/m, a = 1418.04(3) pm, b = 362.660(7) pm, c = 885.48(2) pm, β = 100.028(1) ], d(Eu-O) in Eu{sub 2}O{sub 3} from 229.9(2) to 238.8(2) pm for the cubic bixbyite (C) type [space group Ia anti 3, a = 1086.87(1) pm]. Neutron diffraction at 50 K and 2 K did not show any sign for magnetic ordering in Sm{sub 2}O{sub 3}. Isotopically enriched {sup 154}Sm{sub 2}O{sub 3} and {sup 153}Eu{sub 2}O{sub 3} were used for the neutron diffraction work because of the enormous absorption cross section of the natural isotopic mixtures for thermal neutrons. The isotopic purity was determined by inductively coupled plasma - mass spectrometry to be 98.9% for {sup 154}Sm and 99.8% for {sup 153}Eu. Advanced analysis of the neutron diffraction data suggest that the bound coherent scattering lengths of {sup 154}Sm and {sup 153}Eu need to be revised. We tentatively propose b{sub c}({sup 154}Sm) = 8.97(6) fm and b{sub c}({sup 153}Eu) = 8.85(3) fm for a neutron wavelength of 186.6 pm to be better values for these isotopes, showing up to 8% deviation from accepted literature values. It is shown that inaccurate scattering lengths may result in severe problems in crystal structure refinements causing erroneous structural details such as occupation parameters, which might be critically linked to physical properties like superconductivity in multinary oxides.

  10. Ammonia concentration and bacterial evaluation of feline whole blood and packed red blood cell units stored for transfusion

    Directory of Open Access Journals (Sweden)

    Eva Spada

    2014-10-01

    Full Text Available Ammonia concentrations increase in human, canine and equine WB and PRBC units during storage. The aim of this study was to determine the effect of storage on ammonia concentration in feline WB and PRBC units stored in a veterinary blood bank and to evaluate possible correlations with bacterial contamination. Ammonia concentration was evaluated in 15 WB units and 2 PRBC units on day 1 and at the end of storage after 35 and 42 days, respectively. In an additional 5 WB units and 4 PRBC units ammonia concentrations were determined daily until the day the normal reference range was exceeded and then weekly to the end of storage. All units were evaluated for bacterial contamination. Ammonia increased markedly during storage as a linear function over time. On the 35th and 42th day of storage at 4±2°C mean±SD ammonia concentration reached 909±158 µg/dl and 1058±212 µg/dl in WB and PRBC units, respectively. Bacterial culture was negative in all units. High ammonia concentrations in stored WB and PRBC units could result in toxicity, particularly in feline recipients with liver failure, portosystemic shunts or those receiving large transfusion volumes. Clinical in vivo studies evaluating the effects on recipients should be performed.

  11. Parvovirus B19 promoter at map unit 6 confers autonomous replication competence and erythroid specificity to adeno-associated virus 2 in primary human hematopoietic progenitor cells.

    Science.gov (United States)

    Wang, X S; Yoder, M C; Zhou, S Z; Srivastava, A

    1995-01-01

    The pathogenic human parvovirus B19 is an autonomously replicating virus with a remarkable tropism for human erythroid progenitor cells. Although the target cell specificity for B19 infection has been suggested to be mediated by the erythrocyte P-antigen receptor (globoside), a number of nonerythroid cells that express this receptor are nonpermissive for B19 replication. To directly test the role of expression from the B19 promoter at map unit 6 (B19p6) in the erythroid cell specificity of B19, we constructed a recombinant adeno-associated virus 2 (AAV), in which the authentic AAV promoter at map unit 5 (AAVp5) was replaced by the B19p6 promoter. Although the wild-type (wt) AAV requires a helper virus for its optimal replication, we hypothesized that inserting the B19p6 promoter in a recombinant AAV would permit autonomous viral replication, but only in erythroid progenitor cells. In this report, we provide evidence that the B19p6 promoter is necessary and sufficient to impart autonomous replication competence and erythroid specificity to AAV in primary human hematopoietic progenitor cells. Thus, expression from the B19p6 promoter plays an important role in post-P-antigen receptor erythroid-cell specificity of parvovirus B19. The AAV-B19 hybrid vector system may also prove to be useful in potential gene therapy of human hemoglobinopathies. Images Fig. 2 Fig. 3 Fig. 4 PMID:8618912

  12. Effects of Leukoreduction and Storage on Erythrocyte Phosphatidylserine Expression and Eicosanoid Concentrations in Units of Canine Packed Red Blood Cells

    National Research Council Canada - National Science Library

    Muro, S.M; Lee, J.H; Stokes, J.V; Ross, M.K; Archer, T.M; Wills, R.W; Mackin, A.J; Thomason, J.M

    2017-01-01

    ...) expression and eicosanoid concentrations. Hypothesis/Objectives To determine the effects of leukoreduction on erythrocyte PS expression and eicosanoid concentrations in stored units of canine pRBCs...

  13. Sensitization of prostate cancer cell lines to 5-fluorocytosine induced by a replication incompetent adenoviral vector carrying a cytosine deaminase transcription unit

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AIM: To investigate the efficiency of cytosine deaminase adenoviral/5-fluorocytosine system on prostate cancer cell lines. METHODS: Cell culture, infectivity test and sensitivity test, observing the bystander effect and animal model experiment were carried out. RESULTS: All the established prostate cancer cell lines were eventually infectable, but ratio of vector/cell and time of exposed at which infection occurs was dependent on the cell lines. The expression of transfered cytosine deaminase gene peaked at different days, but persisted beyond 11 days. The prostate cell lines were sensitized to the 5-fluorocytosine by infection with the cytosine deaminase gene adenoviral vector, and only 5% of the LNCap and 10% of the RM-1 cells infected were required for 100% cell death. In the animal model, there was significant eradiation of tumor growth at the ratio of 400 vector particles/cell and with the systematic treatment of 5-fluorocytosine. CONCLUSION: The adenoviral vector carrying a cytosine deaminase transcription unit can sensitize the prostate cancer cell lines to 5-fluorocytosine, and the system can significantly inhibit the growth of prostatic tumor in mice.

  14. CKbeta8-1 alters expression of cyclin E in colony forming units-granulocyte macrophage (CFU-GM) lineage from human cord blood CD34+ cells.

    Science.gov (United States)

    Noh, Eui Kyu; Ra, Jae Sun; Lee, Seong Ae; Kwon, Byoung S; Han, In Seob

    2005-12-31

    A C6 beta-chemokine, CKbeta8-1, suppressed the colony formation of CD34+ cells of human cord blood (CB). Molecular mechanisms involved in CKbeta8-1-medicated suppression of colony formation of CD34+ cells are not known. To address this issue, the level of various G1/S cell cycle regulating proteins in CKbeta8-1-treated CD34+ cells were compared with those in untreated CD34+ cells. CKbeta8-1 did not significantly alter the expression of the G1/S cycle regulation proteins (cyclin D1, D3, and E), CDK inhibitor (p27and Rb), and other cell proliferation regulation protein (p53) in CB CD34+ cells. Here we describe an in vitro system in which CB CD34+ cells were committed to a multipotent progenitor lineage of colony forming units-granulocyte/macrophage (CFU-GM) by a simple combination of recombinant human (rh) GM-CSF and rhIL-3. In this culture system, we found that cyclin E protein appeared later and disappeared faster in the CKbeta8-1-treated cells than in the control cells during CFU-GM lineage development. These findings suggested that cyclin E may play a role in suppressing the colony formation of CFU-GM by CKbeta8-1.

  15. Cryopreserved CD34(+) Cell Dose, but Not Total Nucleated Cell Dose, Influences Hematopoietic Recovery and Extensive Chronic Graft-versus-Host Disease after Single-Unit Cord Blood Transplantation in Adult Patients.

    Science.gov (United States)

    Konuma, Takaaki; Kato, Seiko; Oiwa-Monna, Maki; Tanoue, Susumu; Ogawa, Miho; Isobe, Masamichi; Tojo, Arinobu; Takahashi, Satoshi

    2017-07-01

    Low cryopreserved total nucleated cell (TNC) dose in a cord blood (CB) unit has been shown to be associated with engraftment failure and mortality after single-unit cord blood transplantation (CBT) in adults. Although CB banks offer specific characteristics of cryopreserved cell dose, such as TNC, CD34(+) cells, and colony-forming unit for granulocyte/macrophage (CFU-GM), the impact of each cell dose on engraftment and outcomes after single-unit CBT in adults remains unclear. We retrospectively analyzed the results of 306 CBTs for 261 adult patients in our institution between 1998 and 2016. The median age was 43 years (range, 16 to 68), the median actual body weight (ABW) was 56.2 kg (range, 36.2 to 104.0), the median ideal body weight (IBW) was 62.3 kg (range, 39.7 to 81.3), the median TNC dose was 2.46 × 10(7)/ABW kg (range, 1.07 to 5.69), the median CD34(+) cell dose was .91 × 10(5)/ABW kg (range, .15 to 7.75), and the median CFU-GM dose was 24.46 × 10(3)/ABW kg (range, .04 to 121.81). Among patients who achieved engraftment, the speed of neutrophil, platelet, and red blood cell engraftment significantly correlated with CD34(+) cell dose, but not with TNC and CFU-GM dose, based on both ABW and IBW. In multivariate analysis, the incidence of extensive chronic graft-versus-host disease (GVHD) was significantly higher in patients receiving the highest CD34(+) cell dose, based on both ABW and IBW. Nevertheless, no cell dose was associated with survival, transplantation-related mortality, and relapse. In conclusion, cryopreserved CD34(+) cell dose was the best predictor for hematopoietic recovery and extensive chronic GVHD after CBT. The cryopreserved CD34(+) cell dose should be used for unit selection criteria in single-unit CBT for adults. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  16. DFT insights into the electronic and optical properties of fluorine-doped monoclinic niobium pentoxide (B-Nb{sub 2}O{sub 5}:F)

    Energy Technology Data Exchange (ETDEWEB)

    El-Shazly, Tamer S.; Rehim, Sayed S.A. [Ain-Shams University, Chemistry Department, Faculty of Science, Cairo (Egypt); Hassan, Walid M.I. [Cairo University, Chemistry Department, Faculty of Science, Giza (Egypt); Allam, Nageh K. [American University in Cairo, Energy Materials Lab (EML), School of Sciences and Engineering, New Cairo (Egypt)

    2016-09-15

    We report on the effect of fluorine doping on the electronic structure and optical properties of monoclinic niobium pentoxide (B-Nb{sub 2}O{sub 5}) as revealed by the first principles calculations. Density functional theory (DFT) along with generalized gradient approximation (GGA) at the revised Perdew-Burke-Ernzerhof (PBEsol) exchange-correlation functional was used in this study. The band calculations revealed that the studied materials are indirect bandgap semiconductors, with bandgap energies of 2.67 and 2.28 eV for the undoped and F-doped B-Nb{sub 2}O{sub 5}, respectively. Upon doping B-Nb{sub 2}O{sub 5}, the Fermi level shifts towards the conduction band, allowing optical absorption in the visible region with enhanced transmittance in the wavelength range 400-1000 nm. The calculated static refractive index of the undoped B-Nb{sub 2}O{sub 5} is in good agreement with the reported experimental value, which is enhanced upon F-incorporation resulting in cladding properties for the F-doped B-Nb{sub 2}O{sub 5}. Also, the effective mass of free charge carriers increased upon F-doping. The enhanced properties were attributed to the effect of the excessive valent electron of the incorporated F atom. (orig.)

  17. Density functional theory insights into the structural stability and Li diffusion properties of monoclinic and orthorhombic Li2FeSiO4 cathodes

    Science.gov (United States)

    Lu, Xia; Chiu, Hsien-Chieh; Bevan, Kirk H.; Jiang, De-Tong; Zaghib, Karim; Demopoulos, George P.

    2016-06-01

    Lithium iron orthosilicate (Li2FeSiO4) is an important alternative cathode for next generation Li-ion batteries due to its high theoretical capacity (330 mA h/g). However, its development has faced great challenges arising from significant structural complexity, including the disordered arrangement/orientation of Fe/Si tetrahedra, polytypes and its poorly understood Li storage and transport properties. In this context, ab-initio calculations are employed to investigate the phase stability and Li diffusion profiles of both monoclinic (P21) and orthorhombic (Pmn21) Li2FeSiO4 orthosilicates. The calculations demonstrate that formation of Lisbnd Fe antisites can induce a metastability competition between both phases, with neither dominating across nearly the entire discharging profile from Li2FeSiO4 through to LiFeSiO4. Furthermore, structural instability is shown to be a serious concern at discharge concentrations below LiFeSiO4 (1 Li extraction) due to the shared occupation of Li donated electrons with oxygen 2p orbitals - rather than the hypothesized transition to a tetravalent Fe4+ state. This finding is further supported by diffusion calculations that have determined a high activation energy barrier towards fast charging and rapid phase transitions. In summary, these theoretical results provide critical and timely insight into the structural dynamics of lithium iron orthosilicate, in pursuit of high energy density cathodes.

  18. Synthesis of monoclinic structured BiVO{sub 4} spindly microtubes in deep eutectic solvent and their application for dye degradation

    Energy Technology Data Exchange (ETDEWEB)

    Liu Wei, E-mail: weiliu@ouc.edu.cn [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Yu Yaqin; Cao Lixin; Su Ge; Liu Xiaoyun; Zhang Lan; Wang Yonggang [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)

    2010-09-15

    Monoclinic structured spindly bismuth vanadate microtubes were fabricated on a large scale by a simple ionothermal treatment in the environment-friendly green solvent of urea/choline chloride. The as-prepared samples were characterized by XRD, SEM, TEM, IR and their photocatalytic activity was evaluated by photocatalytic decolorization of rhodamine B aqueous solution under visible-light irradiation. As-obtained BiVO{sub 4} microtubes exhibit the spindly shape with a side length of ca. 800 nm and a wall thickness of ca. 100 nm. The opening of these microtubes presents a saw-toothed structure, which is seldom in other tube-shaped materials. The formation mechanism of the spindly microtubes is ascribed to the complex cooperation of the reaction-crystallization process controlled by BiOCl and the nucleation-growth process of nanosheets induced by solvent molecules attached on the surface of microtubes. Such spindly microtubes exhibit much higher visible-light photocatalytic activity than that of bulk BiVO{sub 4} prepared by solid-state reaction, possibly resulting from their large surface area and improved crystallinity.

  19. Surfactant-free synthesis of hyperbranched monoclinic bismuth vanadate and its applications in photocatalysis, gas sensing, and lithium-ion batteries.

    Science.gov (United States)

    Zhao, Yu; Xie, Yi; Zhu, Xi; Yan, Si; Wang, Sunxi

    2008-01-01

    Hyperbranched monoclinic BiVO(4) (h-BiVO(4)) has been synthesized on a large scale and with good uniformity by a surfactant-free hydrothermal route. h-BiVO(4) consists of four trunks with branches distributed on opposite sides. From observation of the intermediates at an early stage of the reaction process, it can be seen that during formation h-BiVO(4) has different growth rates along the a, b, and c axes. Based on crystal structure analysis and experimental results, h-BiVO(4) shows preferential growth along the [100] direction, and subsequently, along the [010] and [001] directions. As-synthesized h-BiVO(4) exhibits excellent photocatalytic ability in the photodegradation reaction of an aqueous solution of RB under visible light. Electrochemical measurements predict that h-BiVO(4) possesses high sensitivity to formaldehyde and ethanol gases, favorable discharge capacity, and capacity retention, which indicate potential applications in the fields of sensing devices and lithium-ion batteries.

  20. A monoclinic polymorph of [(Z-N-(3-chlorophenyl-O-methylthiocarbamato-κS](triphenylphosphane-κPgold(I: crystal structure and Hirshfeld surface analysis

    Directory of Open Access Journals (Sweden)

    Chien Ing Yeo

    2016-08-01

    Full Text Available The title compound, [Au(C8H7ClNOS(C18H15P], is a monoclinic (P21/n, Z′ = 1; form β polymorph of the previously reported triclinic form (P-1, Z′ = 1; form α [Tadbuppa & Tiekink (2010. Acta Cryst. E66, m664]. The molecular structures of both forms feature an almost linear gold(I coordination geometry [P—Au—S = 175.62 (5° in the title polymorph], being coordinated by thiolate S and phosphane P atoms, a Z conformation about the C=N bond and an intramolecular Au...O contact. The major conformational difference relates to the relative orientations of the residues about the Au—S bond: the P—Au—S—C torsion angles are −8.4 (7 and 106.2 (7° in forms α and β, respectively. The molecular packing of form β features centrosymmetric aggregates sustained by aryl-C—H...O interactions, which are connected into a three-dimensional network by aryl-C—H...π contacts. The Hirshfeld analysis of forms α and β shows many similarities with the notable exception of the influence of C—H...O interactions in form β.

  1. Magnetic properties of monoclinic lanthanide metaborates, Ln(BO2)3, Ln  =  Pr, Nd, Gd, Tb

    Science.gov (United States)

    Mukherjee, P.; Suard, E.; Dutton, S. E.

    2017-10-01

    The bulk magnetic properties of the lanthanide metaborates, Ln(BO2)3, Ln  =  Pr, Nd, Gd, Tb are studied using magnetic susceptibility, heat capacity and isothermal magnetisation measurements. They are found to crystallise in a monoclinic structure containing chains of magnetic Ln 3+ and could therefore exhibit features of low-dimensional magnetism and frustration. Pr(BO2)3 is found to have a non-magnetic singlet ground state. No magnetic ordering is observed down to 0.4 K for Nd(BO2)3. Gd(BO2)3 exhibits a sharp magnetic transition at 1.1 K, corresponding to 3D magnetic ordering. Tb(BO2)3 shows two magnetic ordering features at 1.05 K and 1.95 K. A magnetisation plateau at a third of the saturation magnetisation is seen at 2 K for both Nd(BO2)3 and Tb(BO2)3, which persists in an applied field of 14 T. This is proposed to be a signature of quasi 1D behaviour in Nd(BO2)3 and Tb(BO2)3.

  2. Tetrakis(μ2-2,2-dimethylpropanoato-κ2O,O′bis[(pyridine-κNcopper(II]: a monoclinic polymorph

    Directory of Open Access Journals (Sweden)

    Lailatun Nazirah Ozair

    2010-05-01

    Full Text Available The structure of the dinuclear title complex, [Cu2(C5H9O24(C5H5N2], represents a monoclinic polymorph of the previously reported triclinic form [Blewett et al. (2006. Acta Cryst. E62, m420–m422]. Each carboxylate group is bidentate bridging and the distorted octahedral geometry about each CuII atom is completed by a pyridine N atom and the other Cu atom [Cu...Cu = 2.6139 (7 Å]. In the crystal, molecules are connected into supramolecular chains via π–π interactions formed by the pyridine rings [centroid–centroid distance = 3.552 (3 Å] and these are connected into a two-dimensional array in the ac plane by C—H...π contacts. One of the tert-butyl groups is disordered over two orientations in a 0.734 (6:0.266 (6 ratio.

  3. Synthesis and characterization of monoclinic rare earth titanates, RE2Ti2O7 (RE = La, Pr, Nd), by a modified SHS method using inorganic activator

    Indian Academy of Sciences (India)

    K Krishnankutty; K R Dayas

    2008-11-01

    The nano particles of phase pure rare earth titanates, synthesized by the SHS technique, get well sintered at lower temperatures compared to the compounds formed by the solid-state method. These dielectrics are highly stable and can be used in the microwave frequency range. We report here a modified SHS method to synthesize phase pure monoclinic RE2Ti2O7 at 350°C through the oxide/nitrate precursors using an inorganic compound, ammonium acetate, in place of the general type of organic activators such as urea, alanine etc. The nanopowders of La2Ti2O7, Pr2Ti2O7 and Nd2Ti2O7 on heating exhibit an exothermic behaviour with a broad maxima in the range 267–284°C and become endothermic with maxima in the range 1043–1220°C; interestingly, the phase pure crystalline material is formed at the temperature of exothermic maxima, as confirmed by XRD.

  4. Growth, vibrational and luminescence analysis of monoclinic KGd(1-x)Prx(WO4)2 (x=0.005, 0.02, 0.05) single crystals

    Science.gov (United States)

    Thangaraju, D.; Moorthy Babu, S.; Durairajan, A.; Balaji, D.; Samuel, P.; Hayakawa, Y.

    2013-01-01

    Growth of pure KGW, 0.5, 2 and 5 wt% Pr3+ doped KGd(WO4)2 single crystals were carried out using top seeded solution growth (TSSG) method with K2WO4 as flux. Growth parameters that include the cooling rate and pulling rate were modified to achieve transparent doped crystals to that of pure crystals. Optically polished samples were used for optical and structural studies. Structure of grown crystals was confirmed and lattice parameter values were calculated using single crystal X-ray diffractometer. Both pure and doped crystals belong to the monoclinic phase with C2/c space group. When compared to pure matrix of KGW, some notable changes were observed in the lattice parameter values of doped crystals. It may be due to the ionic radii mismatch of replacing praseodymium ion in the place of gadolinium ion. Absorption and emission measurements were carried out for the 2 mm thick polished samples. The doped samples show a very good transparency with an intense absorption band around the blue region of the spectrum with additional absorption peaks in the IR region as well. Strong red emission was observed in the emission spectrum. The energy levels and their corresponding transitions were figured out in Pr3+ ions inside the matrix. Emission characteristics were compared for different dopant concentration. Raman spectra reveal the intense tungstate vibrational modes in the higher frequency region. Comparison of pure and doped samples reveal that there is no significant change in vibrational modes at higher doping concentration.

  5. Cre/loxP-mediated excision of a neomycin resistance expression unit from an integrated retroviral vector increases long terminal repeat-driven transcription in human hematopoietic cells.

    Science.gov (United States)

    Fernex, C; Dubreuil, P; Mannoni, P; Bagnis, C

    1997-01-01

    Recombinant retroviruses are currently the most attractive vehicles for gene transfer into hematopoietic cells. Retroviral vectors often contain an easily selectable marker gene in addition to the gene of interest. However, the presence and selection for expression of the selectable gene often result in a significant reduction of the expression of the gene of interest in the transduced cells. In order to circumvent this problem, we have developed a Cre/loxP recombination system for specific excision of the selectable expression unit from integrated retroviruses. A retroviral vector, containing both a neomycin resistance expression unit flanked by loxP sites and granulocyte-macrophage colony-stimulating factor cDNA, was used to transduce the human hematopoietic K-562 cell line. Four transduced cell clones were then superinfected with a retrovirus containing a Cre recombinase expression unit. Molecular analyses of 30 doubly transduced subclones showed a strict correlation between cre expression and loxP-flanked selectable cassette excision, thus implying that Cre recombinase activity is very efficient in a retroviral context. Moreover, the excision of the selectable cassette results in a significant increase of granulocyte-macrophage colony-stimulating factor transcription driven by the retroviral promoter. PMID:9311833

  6. Endogenous chloride channels of insect sf9 cells. Evidence for coordinated activity of small elementary channel units

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Gabriel, S. E.; Stutts, M. J.

    1996-01-01

    The endogenous Cl- conductance of Spodoptera frugiperda (Sf9) cells was studied 20-35 h after plating out of either uninfected cells or cells infected by a baculovirus vector carrying the cloned beta-galactosidase gene (beta-Gal cells). With the cation Tris+ in the pipette and Na+ in the bath...

  7. Heat and Mass Transfer during Hydrogen Generation in an Array of Fuel Bars of a BWR Using a Periodic Unit Cell

    Directory of Open Access Journals (Sweden)

    H. Romero-Paredes

    2012-01-01

    Full Text Available This paper presents, the numerical analysis of heat and mass transfer during hydrogen generation in an array of fuel cylinder bars, each coated with a cladding and a steam current flowing outside the cylinders. The analysis considers the fuel element without mitigation effects. The system consists of a representative periodic unit cell where the initial and boundary-value problems for heat and mass transfer were solved. In this unit cell, we considered that a fuel element is coated by a cladding with steam surrounding it as a coolant. The numerical simulations allow describing the evolution of the temperature and concentration profiles inside the nuclear reactor and could be used as a basis for hybrid upscaling simulations.

  8. Density Functional Study on A-Units Based on Thieno[3,4- c]pyrrole-4,6-dione for Organic Solar Cells

    Science.gov (United States)

    Tang, Xiaoqin; Shen, Wei; Fu, Zhiyong; Liu, Xiaorui; Li, Ming

    2017-08-01

    The use of polymer donor materials has allowed great progress in organic solar cells. To search for potential donor materials, we have designed a series of donor-acceptor (D-A)-type alternating polymers composed of dithieno[3,2- b:2',3'- d]pyrrole (DTP) electron-rich units and thieno[3,4- c]pyrrole-4,6-dione (TPD) electron-deficient units. Their electronic and optical properties have been investigated using density functional theory and Marcus theory. The calculation results demonstrate that introduction of cyclic compounds (furyl, thienyl, and phenyl) into electron-deficient units of the molecules can result in lower highest occupied molecular orbital (HOMO) levels and reorganization energies compared with the experimental molecule ( X 0 ). To investigate the effects of electron-withdrawing units, three electron-withdrawing substituents (-OCH3, -F, and -CN) were introduced into the thienyl. The results indicated that the polymer X 2-3 will show the best performance among the designed polymers, offering low-lying HOMO energy level (-5.47 eV), narrow energy gap (1.97 eV), and high hole mobility (7.45 × 10-2 cm2 V-1 s-1). This work may provide a guideline for the design of efficient D-A polymers for organic solar cells with enhanced performance.

  9. QtUCP-A program for determining unit-cell parameters in electron diffraction experiments using double-tilt and rotation-tilt holders

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hongsheng [Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: zhaohscas@yahoo.com.cn; Wu Deqi [Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Yao Jincheng; Chang Aimin [Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China)

    2008-11-15

    A computer program, QtUCP, has been developed based on several well-established algorithms using GCC 4.0 and Qt 4.0 (Open Source Edition) under Debian GNU/Linux 4.0r0. It can determine the unit-cell parameters from an electron diffraction tilt series obtained from both double-tilt and rotation-tilt holders. In this approach, two or more primitive cells of the reciprocal lattice are determined from experimental data, in the meantime, the measurement errors of the tilt angles are checked and minimized. Subsequently, the derived primitive cells are converted into the reduced form and then transformed into the reduced direct primitive cell. Finally all the patterns are indexed and the least-squares refinement is employed to obtain the optimized results of the lattice parameters. Finally, two examples are given to show the application of the program, one is based on the experiment, the other is from the simulation.

  10. QtUCP-a program for determining unit-cell parameters in electron diffraction experiments using double-tilt and rotation-tilt holders.

    Science.gov (United States)

    Zhao, Hongsheng; Wu, Deqi; Yao, Jincheng; Chang, Aimin

    2008-11-01

    A computer program, QtUCP, has been developed based on several well-established algorithms using GCC 4.0 and Qt 4.0 (Open Source Edition) under Debian GNU/Linux 4.0r0. It can determine the unit-cell parameters from an electron diffraction tilt series obtained from both double-tilt and rotation-tilt holders. In this approach, two or more primitive cells of the reciprocal lattice are determined from experimental data, in the meantime, the measurement errors of the tilt angles are checked and minimized. Subsequently, the derived primitive cells are converted into the reduced form and then transformed into the reduced direct primitive cell. Finally all the patterns are indexed and the least-squares refinement is employed to obtain the optimized results of the lattice parameters. Finally, two examples are given to show the application of the program, one is based on the experiment, the other is from the simulation.

  11. High-temperature superconductivity in single-unit-cell FeSe films on anatase TiO2(001)

    OpenAIRE

    Ding, Hao; Lv, Yan-Feng; Zhao, Kun; Wang, Wen-Lin; Wang, Lili; Song, Can-Li; Chen, Xi; Ma, Xu-Cun; Xue, Qi-Kun

    2016-01-01

    We report on the observation of high-temperature ($T_\\textrm{c}$) superconductivity and magnetic vortices in single-unit-cell FeSe films on anatase TiO$_2$(001) substrate by using scanning tunneling microscopy. A systematic study and engineering of interfacial properties has clarified the essential roles of substrate in realizing the high-$T_\\textrm{c}$ superconductivity, probably via interface-induced electron-phonon coupling enhancement and charge transfer. By visualizing and tuning the oxy...

  12. For assessment of changes in intraoperative red blood cell transfusion practices over time, the pooled incidence of transfusion correlates highly with total units transfused.

    Science.gov (United States)

    Dexter, Franklin; Epstein, Richard H

    2017-06-01

    Multiple studies nationwide and at single hospitals have examined changes over time in the incidence of perioperative red blood cell (RBC) transfusion. However, the cost of RBC transfusions is related to the number of RBC units transfused, not to the incidence. We evaluate whether the readily available incidence of RBC transfusion can be used as a valid surrogate measure. Observational retrospective study. One tertiary, academic hospital. 394,789 cases of 1885 procedures over N=42 quarters of the year. None. Incidence and number of RBC units transfused intraoperatively. The number of RBC units transfused per case did not follow a Poisson distribution, confirming that the number of units and incidence of transfusion are not interchangeable for analyzing decisions by case. However, with all cases of each quarter combined, the Spearman correlation was 0.98±0.01 between each quarter's incidence of RBC transfusion and mean RBC units transfused per case (Punits transfused. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Diffractive stacks of metamaterial lattices with a complex unit cell: Self-consistent long-range bianisotropic interactions in experiment and theory

    Science.gov (United States)

    Kwadrin, Andrej; Koenderink, A. Femius

    2014-01-01

    Metasurfaces and metamaterials promise arbitrary rerouting of light using two-dimensional (2D) planar arrangements of electric and magnetic scatterers, respectively, 3D stacks built out of such 2D planes. An important problem is how to self-consistently model the response of these systems in a manner that retains dipole intuition yet does full justice to the self-consistent multiple scattering via near-field and far-field retarded interactions. We set up such a general model for metamaterial lattices of complex 2D unit cells of poly-atomic basis as well as allowing for stacking in a third dimension. In particular, each scatterer is quantified by a magnetoelectric polarizability tensor and Ewald lattice summation deals with all near-field and long-range retarded electric, magnetic, and magnetoelectric couplings self-consistently. We show in theory and experiment that grating diffraction orders of dilute split ring lattices with complex unit cells show a background-free signature of magnetic dipole response. For denser lattices experiment and theory show that complex unit cells can reduce the apparent effect of bianisotropy, i.e., the strong oblique-incidence handed response that was reported for simple split ring lattices. Finally, the method is applied to calculate transmission of finite stacks of lattices. Thereby our simple methodology allows us to trace the emergence of effective material constants when building a 3D metamaterial layer by layer, as well as facilitating the design of metasurfaces.

  14. Application of Three Unit-Cells Models on Mechanical Analysis of 3D Five-Directional and Full Five-Directional Braided Composites

    Science.gov (United States)

    Zhang, Chao; Xu, Xiwu; Chen, Kang

    2013-10-01

    As new lightweight textile material, 3D five directional and full five directional braided composites (5DBC and F5DBC) have tremendous potential applications in the aerospace industry. Before they are used in primary loading-bearing structures, a rational characterization of their mechanical properties is essential. In this paper, three types of unit-cell models corresponding to the interior, surface and corner regions of 5DBC and F5DBC are proposed. By introducing the reasonable boundary conditions, the effective stiffness properties of these two materials are predicted and compared by the three unit-cells models. The detailed mechanical response characteristic of the three unit-cell models is presented and analyzed in various loading cases. Numerical results show good agreement with experiment data, thus validates the proposed simulation method. Moreover, a parametric study is carried out for analyzing the effects of braiding angle and fiber volume fraction on the elastic properties of 5DBC and F5DBC. The obtained results can help designers to optimize the braided composite structures.

  15. A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications

    Directory of Open Access Journals (Sweden)

    Mohammad Tariqul Islam

    2015-05-01

    Full Text Available This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator and CLS (capacitive loaded strip unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2 covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors.

  16. Square-Mile Cells that represent Proprietary Gas-producing Wells from Shale Intervals in the United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey has compiled a map of shale gas assessments in the United States that were completed by 2012, such assessments having been included as...

  17. Surface, optical characteristics and photocatalytic ability of Scheelite-type monoclinic Bi{sub 3}FeMo{sub 2}O{sub 12} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nie, Xinming, E-mail: nxinming@jsnu.edu.cn; Wulayin, Wumitijiang; Song, Tingting; Wu, Minxiao; Qiao, Xuebin, E-mail: qiaoxb@jsnu.edu.cn

    2016-11-30

    Highlights: • Scheelite-type photocatalyst Bi{sub 3}FeMo{sub 2}O{sub 12} with B-superstructure was developed. • Bi{sub 3}FeMo{sub 2}O{sub 12} has high efficient optical absorption in visible wavelength region. • The narrow band energy 2.3 eV was characterized by direct allowed type. • It presents efficient photodegradation on RhB dye solution driven by visible-light. - Abstract: Bi{sub 3}FeMo{sub 2}O{sub 12} nanoparticles with the Scheelite-type monoclinic structure were prepared by the Pechini synthesis. The Bi{sub 3}FeMo{sub 2}O{sub 12} nanoparticle has a size of about 50 nm. The phase formation and structural characteristic were studied by X-ray diffraction (XRD) patterns and Rietveld refinements. The Scheelite framework is characterized by a superstructure constructed by the ordered arrangement of Fe/Mo tetrahedral on the B sites. The surface characteristics of Bi{sub 3}FeMo{sub 2}O{sub 12} nanoparticles were studied by the measurements such as the scanning electron microscope (SEM), the transmission electron microscopy (TEM), and the N{sub 2}-adsorption–desorption isotherm. Bi{sub 3}FeMo{sub 2}O{sub 12} nanoparticles present an efficient optical absorption in a wide wavelength region from UV to 540 nm. The band gap energy was decided to be 2.3 eV and characterized by a direct allowed electronic optical transition. The photocatalytic activity of Bi{sub 3}FeMo{sub 2}O{sub 12} nanoparticles was confirmed by the photodegradation of the rhodamine B (RhB) dye solution. The experiments indicate that the Scheelite-type molybdate could be a potential candidate of a visible-light-driven photocatalyst.

  18. Crystal field analysis of Nd{sup 3+} energy levels in monoclinic NdAl{sub 3}(BO{sub 3}){sub 4} laser

    Energy Technology Data Exchange (ETDEWEB)

    Cascales, C.; Zaldo, C. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, Madrid (Spain); Caldino, U. [Departamento de Fisica, Universidad Autonoma Metropolitana, Iztapalapa, Mexico DF (Mexico); Garcia Sole, J. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, Madrid (Spain); Luo, Z.D. [Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian (China)

    2001-09-03

    The energies of 135 Kramers doublets extending up to the {sup 2}H1{sub 11/2} multiplet for Nd{sup 3+} in a monoclinic C2/c space group (No 15) NdAl{sub 3}(BO{sub 3}){sub 4} (NAB) single crystal laser have been determined from polarized optical absorption and photoluminescence measurements at 7 K. The strongly polarized character of the Nd spectra has been discussed under the assumption of a local D{sub 3} symmetry, higher than the C{sub 2} symmetry of NAB, and the observed energy levels have been labelled with the adequate crystal quantum numbers and irreducible representations. A detailed Hamiltonian of 21 parameters has been used in the simulation of the energy levels and associated wavefunctions of the 4f{sup 3} configuration of Nd{sup 3+}. The diagonalized complete energy matrix combines simultaneously the free-ion and single-particle crystal field interactions. Starting B{sup k}{sub q} CF parameters were calculated from the semi-empirical simple overlap model SOM. A comparative simulation considering the C{sub 2} symmetry of NAB is provided. Moreover, two-electron CF interactions as well as an empirical correction have been tested in calculating the anomalous splitting of the {sup 2}H2{sub 11/2} levels. A final fit in D{sub 3} symmetry produces a very good adjustment with a low rms deviation {sigma}=15.3 cm{sup -1} between observed and calculated energy levels. (author)

  19. [Endoplasmic-mitochondrial Ca(2+)-functional unit: dependence of respiration of secretory cells on activity of ryanodine- and IP3 - sensitive Ca(2+)-channels].

    Science.gov (United States)

    Velykopols'ka, O Iu; Man'ko, B O; Man'ko, V V

    2012-01-01

    Using Clark oxygen electrode, dependence of mitochondrial functions on Ca(2+)-release channels activity of Chironomus plumosus L. larvae salivary glands suspension was investigated. Cells were ATP-permeabilized in order to enable penetration of exogenous oxidative substrates. Activation of plasmalemmal P2X-receptors (as well as P2Y-receptors) per se does not modify the endogenous respiration of salivary gland suspension. That is, Ca(2+)-influx from extracellular medium does not influence functional activity of mitochondria, although they are located along the basal part of the plasma membrane. Activation of RyRs intensifies endogenous respiration and pyruvate-malate-stimulated respiration, but not succinate-stimulated respiration. Neither activation of IP3Rs (via P2Y-receptors activation), nor their inhibition alters endogenous respiration. Nevertheless, IP3Rs inhibition by 2-APB intensifies succinate-stimulated respiration. All abovementioned facts testify that Ca2+, released from stores via channels, alters functional activity of mitochondria, and undoubtedly confirm the existence of endoplasmic-mitochondrial Ca(2+)-functional unit in Ch. plumosus larvae salivary glands secretory cells. In steady state of endoplasmic-mitochondrial Ca(2+)-functional unit the spontaneous activity of IP3Rs is observed; released through IP3Rs, Ca2+ is accumulated in mitochondria via uniporter and modulates oxidative processes. Activation of RyRs induces the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to the active state, which is required to intensify cell respiration and oxidative phosphorylation. As expected, the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to inactivated state (i. e. inhibition of Ca(2+)-release channels at excessive [Ca2+]i) limits the duration of signal transduction, has protective nature and prevents apoptosis.

  20. Acquired hemoglobin variants and exposure to glucose-6-phosphate dehydrogenase deficient red blood cell units during exchange transfusion for sickle cell disease in a patient requiring antigen-matched blood.

    Science.gov (United States)

    Raciti, Patricia M; Francis, Richard O; Spitalnik, Patrice F; Schwartz, Joseph; Jhang, Jeffrey S

    2013-08-01

    Red blood cell exchange (RBCEx) is frequently used in the management of patients with sickle cell disease (SCD) and acute chest syndrome or stroke, or to maintain target hemoglobin S (HbS) levels. In these settings, RBCEx is a category I or II recommendation according to guidelines on the use of therapeutic apheresis published by the American Society for Apheresis. Matching donor red blood cells (RBCs) to recipient phenotypes (e.g., C, E, K-antigen negative) can decrease the risk of alloimmunization in patients with multi-transfused SCD. However, this may select for donors with a higher prevalence of RBC disorders for which screening is not performed. This report describes a patient with SCD treated with RBCEx using five units negative for C, E, K, Fya, Fyb (prospectively matched), four of which were from donors with hemoglobin variants and/or glucose-6-phosphate dehydrogenase (G6PD) deficiency. Pre-RBCEx HbS quantification by high performance liquid chromatography (HPLC) demonstrated 49.3% HbS and 2.8% hemoglobin C, presumably from transfusion of a hemoglobin C-containing RBC unit during a previous RBCEx. Post-RBCEx HPLC showed the appearance of hemoglobin G-Philadelphia. Two units were G6PD-deficient. The patient did well, but the consequences of transfusing RBC units that are G6PD-deficient and contain hemoglobin variants are unknown. Additional studies are needed to investigate effects on storage, in-vivo RBC recovery and survival, and physiological effects following transfusion of these units. Post-RBCEx HPLC can monitor RBCEx efficiency and detect the presence of abnormal transfused units.

  1. Interleukin-10 inhibits burst-forming unit-erythroid growth by suppression of endogenous granulocyte-macrophage colony-stimulating factor production from T cells.

    Science.gov (United States)

    Oehler, L; Kollars, M; Bohle, B; Berer, A; Reiter, E; Lechner, K; Geissler, K

    1999-02-01

    Numerous cytokines released from accessory cells have been shown to exert either stimulatory or inhibitory growth signals on burst-forming unit-erythroid (BFU-E) growth. Because of its cytokine synthesis-inhibiting effects on T cells and monocytes, interleukin-10 (IL-10) may be a potential candidate for indirectly affecting erythropoiesis. We investigated the effects of IL-10 on BFU-E growth from normal human peripheral blood mononuclear cells (PBMC) using a clonogenic progenitor cell assay. The addition of recombinant human IL-10 to cultures containing recombinant human erythropoietin suppressed BFU-E growth in a dose-dependent manner (by 55.2%, range 47.3-63.3%, p cultivating highly enriched CD34+ cells. BFU-E growth from PBMC also was markedly suppressed in the presence of a neutralizing anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibody (by 48.7%, range 32.9-61.2% inhibition,p < 0.01), but not by neutralizing antibodies against granulocyte colony-stimulating factor and interleukin-3. This suggests a stimulatory role of endogenously released GM-CSF on BFU-E formation. Also, the addition of exogenous GM-CSF completely restored IL-10-induced suppression of BFU-E growth. To determine the cellular source of GM-CSF production, we analyzed GM-CSF levels in suspension cultures containing PBMC that were either depleted of monocytes or T cells. Monocyte-depleted PBMC showed spontaneous production of increasing amounts of GM-CSF on days 3, 5, and 7, respectively, which could be suppressed by IL-10, whereas GM-CSF levels did not increase in cultures containing T-cell-depleted PBMC. Our data indicate that IL-10 inhibits the growth of erythroid progenitor cells in vitro, most likely by suppression of endogenous GM-CSF production from T cells.

  2. X-ray powder diffraction characterization of the large-volume unit cell of the M8 murataite polytype

    OpenAIRE

    MAKI, Ryosuke S. S.; Morgan, Peter E. D.; Suzuki, Yoshikazu

    2016-01-01

    We have used conventional X-ray powder diffraction to study one of the largest volume inorganic mixed oxide unit-supercell structures done so far. This necessitated some small-angle X-ray scattering-like observations at low angles from

  3. Use of the Primitive Unit Cell in Understanding Subtle Features of the Cubic Closest-Packed Structure

    Science.gov (United States)

    Hawkins, John A.; Rittenhouse, Jeffrey L.; Soper, Linda M.; Rittenhouse, Robert C.

    2008-01-01

    One of the most important crystal structures adopted by metals is characterized by the "abcabc"...stacking of close-packed layers. This structure is commonly referred to in textbooks as the cubic close-packed (ccp) or face-centered cubic (fcc) structure, since the entire lattice can be generated by replication of a face-centered cubic unit cell…

  4. About lamination upper and convexification lower bounds on the free energy of monoclinic shape memory alloys in the context of T 3-configurations and R-phase formation

    Science.gov (United States)

    Fechte-Heinen, R.; Schlömerkemper, A.

    2016-11-01

    This work is concerned with different estimates of the quasiconvexification of multi-well energy landscapes of NiTi shape memory alloys, which models the overall behavior of the material. Within the setting of the geometrically linear theory of elasticity, we consider a formula of the quasiconvexification which involves the so-called energy of mixing.We are interested in lower and upper bounds on the energy of mixing in order to get a better understanding of the quasiconvexification. The lower bound on the energy of mixing is obtained by convexification; it is also called Sachs or Reuß lower bound. The upper bound on the energy of mixing is based on second-order lamination. In particular, we are interested in the difference between the lower and upper bounds. Our numerical simulations show that the difference is in fact of the order of 1% and less in martensitic NiTi, even though both bounds on the energy of mixing were rather expected to differ more significantly. Hence, in various circumstances it may be justified to simply work with the convexification of the multi-well energy, which is relatively easy to deal with, or with the lamination upper bound, which always corresponds to a physically realistic microstructure, as an estimate of the quasiconvexification. In order to obtain a potentially large difference between upper and lower bound, we consider the bounds along paths in strain space which involve incompatible strains. In monoclinic shape memory alloys, three-tuples of pairwise incompatible strains play a special role since they form so-called T 3-configurations, originally discussed in a stress-free setting. In this work, we therefore consider in particular numerical simulations along paths in strain space which are related to these T 3-configurations. Interestingly, we observe that the second-order lamination upper bound along such paths is related to the geometry of the T 3-configurations. In addition to the purely martensitic regime, we also consider

  5. Red blood cell transfusions--are we narrowing the evidence-practice gap? An observational study in 5 Israeli intensive care units.

    Science.gov (United States)

    Cohen, Jonathan; Kagan, Ilya; Hershcovici, Remos; Bursztein-De Myttenaere, Sylvianne; Makhoul, Nicola; Samkohvalov, Alexander; Hersch, Moshe; Einav, Sharon; Berezovsky, Vadim; Jakobson, Daniel Jorge; Singer, Pierre

    2011-02-01

    The aim of the study was to document transfusion practices in a cross section of general intensive care units (ICUs) in Israel and to determine whether current guidelines are being applied. This prospective study was performed in 5 general ICUs in Israel over a 3-month period. Red cell transfusion data collected on consecutive patients included the trigger, units transfused per transfusion event, and indications, categorized either to treat a specified condition for which transfusions may be beneficial (acute hemorrhage, acute myocardial ischemia, or severe sepsis) or to treat a low hemoglobin concentration. Of the 238 patients studied, 50% received at least one red blood cell transfusion. The main indication for transfusion (43.7%, or 162/368 U transfused) was to treat a low hemoglobin concentration, in the absence of one of the specified conditions. Total red cell use was 3.0 ± 2.9 U per admission, and patients received a mean of 1.2 ± 0.4 U per transfusion event. The transfusion trigger for the whole group was 7.9 ± 1.1 g/dL. This did not differ significantly between the indications apart from a significantly higher trigger for patients with acute myocardial ischemia (8.8 ± 0.9 g/dL). In addition, patients with a history of heart disease had a higher trigger irrespective of the primary indication for transfusion and received significantly more units per transfusion event. Patients receiving a transfusion had significantly longer ICU stay and hospital mortality. Our study showed that evidence-practice gaps continue to exist, and it appears that physician behavior is mainly driven by the absolute level of hemoglobin. Educational interventions focused on these factors are required to limit the widespread and often unnecessary use of this scarce and potentially harmful resource. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Endogenous chloride channels of insect sf9 cells. Evidence for coordinated activity of small elementary channel units

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Gabriel, S. E.; Stutts, M. J.

    1996-01-01

    ) openings interrupted by similar long closures. In the open state, channels exhibited fast burst-like closures. Since the patches normally contained more than a single channel, it was not possible to measure open and closed dwell-time distributions for comparing single-Cl- channel activity with the kinetic....../150) of approximately 3.5 pS and approximately 35 pS, respectively. All states reversed near the same membrane potential, and they exhibited similar halide ion selectivity, P1 > PCl approximately PBr. Accordingly, Cl- current amplitudes larger than current flow through the smallest channel unit resolved seem to result...... from simultaneous open/shut events of two or more channel units....

  7. Oil and Gas Exploration and Production in the United States Shown as One-Mile Cells (Decadal Time Slices)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A cells polygon feature class was created by the U.S. Geological Survey (USGS) to illustrate the degree of exploration, type of production, and distribution of...

  8. Risk and outcome analysis of 1832 consecutively excised basal cell carcinomas in a tertiary referral plastic surgery unit.

    LENUS (Irish Health Repository)

    Malik, Vinod

    2012-02-01

    BACKGROUND: Basal cell carcinomas are the most prevalent of all skin cancers worldwide and form the majority of the surgical workload for most modern cutaneous malignancy centres. Primary surgical removal of basal cell carcinomas remains the gold standard of treatment but, despite almost two centuries of surgical experience, rates of incomplete surgical excision of up to 50% are still reported. The aim of this study was to assess, quantify and perform comparative analysis of the outcomes and predictive factors of consecutive primarily-excised basal cell carcinomas in a tertiary centre over a six-year period. METHODS: Retrospective audit was conducted on all patients who underwent surgical excision of basal cell carcinomas from January 2000 to December 2005. Assessment parameters included patient biographics, tumour management differences and detailed histopathological analysis of tumour margins and subtypes. RESULTS: One thousand eight hundred and thirty two basal cell carcinomas were excised from 1329 patients over the designated time period. Two hundred and fifty one (14%) lesions were incompletely excised with 135 (7.4%) involving the peripheral margin only, 48 (2.6%) the deep margin only and 41 (2.2%) involving both. Nasal location was the most common predictor of incomplete excision. CONCLUSIONS: Overall basal cell carcinomas excision rates compared favourably with international reported standards but attention to a variety of surgical and histological risk factors may improve this further.

  9. Final report on the United States phase I clinical trial of the hypoxic cell radiosensitizer, misonidazole (Ro-07-0582; NSC No. 261037

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T.L. (Univ. of California, San Francisco); Wasserman, T.H.; Johnson, R.J.; Levin, V.A.; VanRaalte, G.

    1981-10-15

    The hypoxic cell sensitizer misonidazole began phase I evaluation in the United States in July 1977. One hundred two patients received 104 individual courses of drug. Drug was administered from once to five times per week over time spans from one to six weeks. The individual doses ranged 1 to 5 g/m. The major toxicity noted was neurologic; 49% of evaluable courses showed peripheral neuropathy, and 9% of evaluable courses showed central nervous system effects and/or ototoxicity. In addition, 48 of 102 patients exhibited some degree of nausea and vomiting. The concomitant administration of dexamethasone and phenytoin sodium appeared to lower the incidence of neuropathy. Observations of efficacy were made comparatively in five patients who had multiple lesions treated with and without misonidazole. All five showed increased response in the lesions treated with misonidazole. It is concluded that misonidazole is a reasonably safe and potentially effective hypoxic cell sensitizer whose dose-limiting toxicity is neurologic.

  10. [Transfer of allogeneic stem cell transplant recipients to the intensive care unit: Guidelines from the Francophone society of marrow transplantation and cellular therapy (SFGM-TC)].

    Science.gov (United States)

    Moreau, Anne-Sophie; Bourhis, Jean-Henri; Contentin, Nathalie; Couturier, Marie-Anne; Delage, Jeremy; Dumesnil, Cécile; Gandemer, Virginie; Hichri, Yosr; Jost, Edgar; Platon, Laura; Jourdain, Mercé; Pène, Frédéric; Yakoub-Agha, Ibrahim

    2016-11-01

    Transferring a patient undergoing an allogeneic stem cell transplantation to the intensive care unit (ICU) is always a challenging situation on a medical and psychological point of view for the patient and his relatives as well as for the medical staff. Despite the progress in hematology and intensive care during the last decade, the prognosis of these patients admitted to the ICU remains poor and mortality is around 50 %. The harmonization working party of the SFGM-TC assembled hematologists and intensive care specialist in order to improve conditions and modalities of the transfer of a patient after allogeneic stem cell transplantation to the ICU. We propose a structured medical form comprising all essential information necessary for optimal medical care on ICU. Copyright © 2016. Published by Elsevier Masson SAS.

  11. A Functional Screen for Myc-Responsive Genes Reveals Serine Hydroxymethyltransferase, a Major Source of the One-Carbon Unit for Cell Metabolism

    Science.gov (United States)

    Nikiforov, Mikhail A.; Chandriani, Sanjay; O'Connell, Brenda; Petrenko, Oleksi; Kotenko, Iulia; Beavis, Andrew; Sedivy, John M.; Cole, Michael D.

    2002-01-01

    A cDNA library enriched with Myc-responsive cDNAs but depleted of myc cDNAs was used in a functional screen for growth enhancement in c-myc-null cells. A cDNA clone for mitochondrial serine hydroxymethyltransferase (mSHMT) that was capable of partial complementation of the growth defects of c-myc-null cells was identified. Expression analysis and chromatin immunoprecipitation demonstrated that mSHMT is a direct Myc target gene. Furthermore, a separate gene encoding the cytoplasmic isoform of the same enzyme is also a direct target of Myc regulation. SHMT enzymes are the major source of the one-carbon unit required for folate metabolism and for the biosynthesis of nucleotides and amino acids. Our data establish a novel functional link between Myc and the regulation of cellular metabolism. PMID:12138190

  12. Protein kinase A induces recruitment of active Na+,K+-ATPase units to the plasma membrane of rat proximal convoluted tubule cells

    Science.gov (United States)

    Carranza, Maria Luisa; Rousselot, Martine; Chibalin, Alexander V; Bertorello, Alejandro M; Favre, Hervé; Féraille, Eric

    1998-01-01

    The aim of this study was to investigate the mechanism of control of Na+,K+-ATPase activity by the cAMP-protein kinase A (PKA) pathway in rat proximal convoluted tubules. For this purpose, we studied the in vitro action of exogenous cAMP (10−3 M dibutyryl-cAMP (db-cAMP) or 8-bromo-cAMP) and endogenous cAMP (direct activation of adenylyl cyclases by 10−5 M forskolin) on Na+,K+-ATPase activity and membrane trafficking.PKA activation stimulated both the cation transport and hydrolytic activity of Na+,K+-ATPase by about 40 %. Transport activity stimulation was specific to the PKA signalling pathway since (1) db-cAMP stimulated the ouabain-sensitive 86Rb+ uptake in a time- and dose-dependent fashion; (2) this effect was abolished by addition of H-89 or Rp-cAMPS, two structurally different PKA inhibitors; and (3) this stimulation was not affected by inhibition of protein kinase C (PKC) by GF109203X. The stimulatory effect of db-cAMP on the hydrolytic activity of Na+,K+-ATPase was accounted for by an increased maximal ATPase rate (Vmax) without alteration of the efficiency of the pump, suggesting that cAMP-PKA pathway was implicated in membrane redistribution control.To test this hypothesis, we used two different approaches: (1) cell surface protein biotinylation and (2) subcellular fractionation. Both approaches confirmed that the cAMP-PKA pathway was implicated in membrane trafficking regulation. The stimulation of Na+,K+-ATPase activity by db-cAMP was associated with an increase (+40 %) in Na+,K+-ATPase units expressed at the cell surface which was assessed by Western blotting after streptavidin precipitation of biotinylated cell surface proteins. Subcellular fractionation confirmed the increased expression in pump units at the cell surface which was accompanied by a decrease (-30 %) in pump units located in the subcellular fraction corresponding to early endosomes.In conclusion, PKA stimulates Na+,K+-ATPase activity, at least in part, by increasing the number of

  13. Novel hydroxyamides and amides containing D-glucopyranose or D-fructose units: Biological assays in MCF-7 and MDST8 cell lines.

    Science.gov (United States)

    Carreiro, Elisabete P; Costa, Ana R; Cordeiro, Maria M; Martins, Rute; Pires, Tiago O; Saraiva, Mafalda; Antunes, Célia M; Burke, Anthony J

    2016-02-01

    A novel library of 15 compounds, hydroxyamides and amides containing a β-D-glucopyranose (D-Gluc) or a β-D-fructose (D-Fruc) units was designed and synthesized for antiproliferative assays in breast (MCF-7) and colon (MDST8) cancer cell lines. Twelve of them were hydroxyamides and were successfully synthesized from β-D-glucuronic acid (D-GluA). Six of these hydroxyamides which were acetylated hydroxy-β-D-glucopyranuronamide 2a-2f (1st Family) and the other six were their respective isomers, that is, hydroxy-β-D-fructuronamide 3a-3f (2nd Family), obtained by acid-base catalyzed isomerization. These compounds have the general structure, D-Gluc-C=ONH-CHR-(CH2)n-OH and D-Fruc-C=ONH-CHR-(CH2)n-OH, where R=an aromatic, alkyl or a hydrogen substituent, with n=0 or 1. Eight of these contained a chiral aminoalcohol group. Three compounds were amides containing a D-glucopyranose unit (3rd Family). SAR studies were conducted with these compounds. Antiproliferative studies showed that compound 4a, the bromo-amide containing the β-D-glucopyranose ring, potently inhibits the proliferation of the MDST8 cells. Five compounds (2e, 2f, 3d, 3e, and 3f) were shown to potently selectively inhibit the proliferation of the MCF-7 cells. Compound 4b was the only one showing inhibition in both cell lines. In general, the more active compounds were the amides and hydroxyamides containing the β-D-fructose moiety, and containing an alkyl group or hydrogen. Half-inhibitory concentrations (IC50) of between 0.01 and 10 μM, were observed.

  14. Dexamethasone Rescues Neurovascular Unit Integrity from Cell Damage Caused by Systemic Administration of Shiga Toxin 2 and Lipopolysaccharide in Mice Motor Cortex

    Science.gov (United States)

    Pinto, Alipio; Jacobsen, Mariana; Geoghegan, Patricia A.; Cangelosi, Adriana; Cejudo, María Laura; Tironi-Farinati, Carla; Goldstein, Jorge

    2013-01-01

    Shiga toxin 2 (Stx2)-producing Escherichia coli (STEC) causes hemorrhagic colitis and hemolytic uremic syndrome (HUS) that can lead to fatal encephalopathies. Neurological abnormalities may occur before or after the onset of systemic pathological symptoms and motor disorders are frequently observed in affected patients and in studies with animal models. As Stx2 succeeds in crossing the blood-brain barrier (BBB) and invading the brain parenchyma, it is highly probable that the observed neurological alterations are based on the possibility that the toxin may trigger the impairment of the neurovascular unit and/or cell damage in the parenchyma. Also, lipopolysaccharide (LPS) produced and secreted by enterohemorrhagic Escherichia coli (EHEC) may aggravate the deleterious effects of Stx2 in the brain. Therefore, this study aimed to determine (i) whether Stx2 affects the neurovascular unit and parenchymal cells, (ii) whether the contribution of LPS aggravates these effects, and (iii) whether an inflammatory event underlies the pathophysiological mechanisms that lead to the observed injury. The administration of a sub-lethal dose of Stx2 was employed to study in detail the motor cortex obtained from a translational murine model of encephalopathy. In the present paper we report that Stx2 damaged microvasculature, caused astrocyte reaction and neuronal degeneration, and that this was aggravated by LPS. Dexamethasone, an anti-inflammatory, reversed the pathologic effects and proved to be an important drug in the treatment of acute encephalopathies. PMID:23894578

  15. Dexamethasone rescues neurovascular unit integrity from cell damage caused by systemic administration of shiga toxin 2 and lipopolysaccharide in mice motor cortex.

    Directory of Open Access Journals (Sweden)

    Alipio Pinto

    Full Text Available Shiga toxin 2 (Stx2-producing Escherichia coli (STEC causes hemorrhagic colitis and hemolytic uremic syndrome (HUS that can lead to fatal encephalopathies. Neurological abnormalities may occur before or after the onset of systemic pathological symptoms and motor disorders are frequently observed in affected patients and in studies with animal models. As Stx2 succeeds in crossing the blood-brain barrier (BBB and invading the brain parenchyma, it is highly probable that the observed neurological alterations are based on the possibility that the toxin may trigger the impairment of the neurovascular unit and/or cell damage in the parenchyma. Also, lipopolysaccharide (LPS produced and secreted by enterohemorrhagic Escherichia coli (EHEC may aggravate the deleterious effects of Stx2 in the brain. Therefore, this study aimed to determine (i whether Stx2 affects the neurovascular unit and parenchymal cells, (ii whether the contribution of LPS aggravates these effects, and (iii whether an inflammatory event underlies the pathophysiological mechanisms that lead to the observed injury. The administration of a sub-lethal dose of Stx2 was employed to study in detail the motor cortex obtained from a translational murine model of encephalopathy. In the present paper we report that Stx2 damaged microvasculature, caused astrocyte reaction and neuronal degeneration, and that this was aggravated by LPS. Dexamethasone, an anti-inflammatory, reversed the pathologic effects and proved to be an important drug in the treatment of acute encephalopathies.

  16. Selective Laser Melting: a regular unit cell approach for the manufacture of porous, titanium, bone in-growth constructs, suitable for orthopedic applications.

    Science.gov (United States)

    Mullen, Lewis; Stamp, Robin C; Brooks, Wesley K; Jones, Eric; Sutcliffe, Christopher J

    2009-05-01

    In this study, a novel porous titanium structure for the purpose of bone in-growth has been designed, manufactured and evaluated. The structure was produced by Selective Laser Melting (SLM); a rapid manufacturing process capable of producing highly intricate, functionally graded parts. The technique described utilizes an approach based on a defined regular unit cell to design and produce structures with a large range of both physical and mechanical properties. These properties can be tailored to suit specific requirements; in particular, functionally graded structures with bone in-growth surfaces exhibiting properties comparable to those of human bone have been manufactured. The structures were manufactured and characterized by unit cell size, strand diameter, porosity, and compression strength. They exhibited a porosity (10-95%) dependant compression strength (0.5-350 Mpa) comparable to the typical naturally occurring range. It is also demonstrated that optimized structures have been produced that possesses ideal qualities for bone in-growth applications and that these structures can be applied in the production of orthopedic devices.

  17. Synthesis, Crystal Structure, and Magnetic Properties of Giant Unit Cell Intermetallics R117Co52+δSn112+γ (R = Y, La, Pr, Nd, Ho

    Directory of Open Access Journals (Sweden)

    Ping Chai

    2016-12-01

    Full Text Available Ternary intermetallics R117Co52+δSn112+γ (R = Y, La, Pr, Nd, and Ho have been prepared by arc-melting followed by annealing at 800 °C. All the compounds belong to the Tb117Fe52Ge112 structure type (space group Fm 3 ¯ m characterized by a complex giant cubic unit cell with a ~ 30 Å. The single-crystal structure determination of Y- and La-containing compounds reveals a significant structural disorder. A comparison of these and earlier reported crystal structures of R117Co52+δSn112+γ suggests that more extensive disorder occurs for structures that contain larger lanthanide atoms. This observation can be explained by the need to maintain optimal bonding interactions as the size of the unit cell increases. Y117Co56Sn115 exhibits weak paramagnetism due to the Co sublattice and does not show magnetic ordering in the 1.8–300 K range. Ho117Co55Sn108 shows ferromagnetic ordering at 10.6 K. Both Pr117Co54Sn112 and Nd117Co54Sn111 exhibit antiferromagnetic ordering at 17 K and 24.7 K, respectively, followed by a spin reorientation transition at lower temperature.

  18. The PRR11-SKA2 Bidirectional Transcription Unit Is Negatively Regulated by p53 through NF-Y in Lung Cancer Cells.

    Science.gov (United States)

    Wang, Yitao; Weng, Huali; Zhang, Ying; Long, Yinjiang; Li, Yi; Niu, Yulong; Song, Fangzhou; Bu, Youquan

    2017-03-01

    We previously identified proline-rich protein 11 (PRR11) as a novel cancer-related gene that is implicated in the regulation of cell cycle and tumorigenesis. Our recent study demonstrated that PRR11 and its adjacent gene, kinetochore associated 2 (SKA2), constitute a classic head-to-head gene pair that is coordinately regulated by nuclear factor Y (NF-Y). In the present study, we further show that the PRR11-SKA2 bidirectional transcription unit is an indirect target of the tumor suppressor p53. A luciferase reporter assay revealed that overexpression of wild type p53, but not mutant p53, significantly represses the basal activity and NF-Y mediated transactivation of the PRR11-SKA2 bidirectional promoter. Deletion and mutation analysis of the PRR11-SKA2 promoter revealed that p53-mediated PRR11-SKA2 repression is dependent on the presence of functional NF-Y binding sites. Furthermore, a co-immunoprecipitation assay revealed that p53 associates with NF-Y in lung cancer cells, and a chromatin immunoprecipitation assay showed that p53 represses PRR11-SKA2 transcription by reducing the binding amount of NF-Y in the PRR11-SKA2 promoter region. Consistently, the ability of p53 to downregulate PRR11-SKA2 transcription was significantly attenuated upon siRNA-mediated depletion of nuclear factor Y subunit beta (NF-YB). Notably, lung cancer patients with lower expression of either PRR11 or SKA2 along with wild type p53 exhibited the best overall survival compared with others with p53 mutation and/or higher expression of either PRR11 or SKA2. Taken together, our results demonstrate that p53 negatively regulates the expression of the PRR11-SKA2 bidirectional transcription unit through NF-Y, suggesting that the inability to repress the PRR11-SKA2 bidirectional transcription unit after loss of p53 might contribute to tumorigenesis.

  19. Inverse Gas Chromatography with Film Cell Unit: An Attractive Alternative Method to Characterize Surface Properties of Thin Films.

    Science.gov (United States)

    Klein, Géraldine L; Pierre, Guillaume; Bellon-Fontaine, Marie-Noëlle; Graber, Marianne

    2015-09-01

    Inverse gas chromatography (IGC) is widely used for the characterization of surfaces. The present work describes a novel IGC tool, the recently developed film cell module, which measures monolithic thin solid film surface properties, whereas only samples in powder or fiber state or polymer-coated supports can be studied by classic IGC. The surface energy of four different solid supports was measured using both classic IGC with columns packed with samples in the powder state, and IGC with the new film cell module or the sessile drop technique, using samples in the film state. The total surface energy and its dispersive and specific components were measured for glass, polyethylene, polyamide and polytetrafluoroethylene. Similar results were obtained for the four materials using the three different techniques. The main conclusion is that the new film cell module for IGC is an attractive alternative to the sessile drop technique as it gives very accurate and reproducible results for surface energy components, with significant savings in time and the possible control of sample humidity and temperature. This film cell module for IGC extends the application field of IGC to any thin solid film and can be used to study the effect of any surface treatment on surface energy.

  20. Numerical Study of the Dynamic Response of Heat and Mass Transfer to Operation Mode Switching of a Unitized Regenerative Fuel Cell

    Directory of Open Access Journals (Sweden)

    Hong Xiao

    2016-12-01

    Full Text Available Knowledge concerning the complicated changes of mass and heat transfer is desired to improve the performance and durability of unitized regenerative fuel cells (URFCs. In this study, a transient, non-isothermal, single-phase, and multi-physics mathematical model for a URFC based on the proton exchange membrane is generated to investigate transient responses in the process of operation mode switching from fuel cell (FC to electrolysis cell (EC. Various heat generation mechanisms, including Joule heat, reaction heat, and the heat attributed to activation polarizations, have been considered in the transient model coupled with electrochemical reaction and mass transfer in porous electrodes. The polarization curves of the steady-state models are validated by experimental data in the literatures. Numerical results reveal that current density, gas mass fractions, and temperature suddenly change with the sudden change of operating voltage in the mode switching process. The response time of temperature is longer than that of current density and gas mass fractions. In both FC and EC modes, the cell temperature and gradient of gas mass fraction in the oxygen side are larger than that in the hydrogen side. The temperature difference of the entire cell is less than 1.5 K. The highest temperature appears at oxygen-side catalyst layer under the FC mode and at membrane under a more stable EC mode. The cell is exothermic all the time. These dynamic responses and phenomena have important implications for heat analysis and provide proven guidelines for the improvement of URFCs mode switching.

  1. Monoclinic form of (cyanato-κN{2,2′-[ethane-1,2-diylbis(nitrilomethylidyne]diphenolato-κ4O,N,N′,O′}manganese(III

    Directory of Open Access Journals (Sweden)

    Daopeng Zhang

    2010-12-01

    Full Text Available The title compound, [Mn(C16H14N2O2(NCO], is a monoclinic polymorph of the previously published orthorhombic form [Lu et al. (2006. Inorg. Chem. 45, 3538–3548]. The MnIII ion is chelated by a tetradentate Schiff base ligand and coordinated by the N atom of a cyanate ligand in a distorted square-pyramidal arrangement. In the crystal, there are short intermolecular Mn...Ophenolate distances of 2.752 (3 Å between pairs of inversion-related molecules.

  2. Functional units in rainbow trout (Salmo gairdneri, Richardson) liver: III. Morphometric analysis of parenchyma, stroma, and component cell types.

    Science.gov (United States)

    Hampton, J A; Lantz, R C; Hinton, D E

    1989-05-01

    Hepatic stroma and parenchyma with its component cell types were quantitatively described in adult male and female actively-spawning 5-year-old rainbow trout (Salmo gairdneri, Richardson). Point-count morphometry of glycol methacrylate sections estimated volume compartments for stroma and parenchyma. Veins composed 85% of the stroma while arteries and bile ducts occupied approximately 6-7% each. Parenchyma accounted for 95% of hepatic volume. Point-count morphometry of transmission electron micrographs estimated volume compartments as well as numerical and surface density measurements for parenchymal components. Within the hepatic parenchymal compartment, hepatocytes occupied 85% and showed significant sex differences. Female hepatocytes were significantly more numerous but were smaller, only 60% of the volume of male hepatocytes. Since hepatocyte nuclear volume was equal in both sexes, differences were due to reduced cytoplasmic volume in females. Perisinusoidal macrophages of females occupied larger volumes of their respective parenchymal compartments, and their larger mean cytoplasmic volumes suggested activation. Biliary epithelial cells of preductules and ductules were numerous. Ratios of numerical density of hepatocytes to biliary epithelial cells were consistent with a tubular arrangement of hepatocytes. Factors possibly mediating the sexual dimorphism are discussed.

  3. 氮化锗多形体的四方、 单斜和正交畸变的理论研究%Theoretical Studies on Tetragonal, Monoclinic and Orthorhombic Distortions of Germanium Nitride Polymorphs

    Institute of Scientific and Technical Information of China (English)

    仓玉萍; 陈东; 杨帆; 杨慧明

    2016-01-01

    采用量子化学从头算方法,对Ge3 N4的四方、单斜和正交结构同质异相体的微结构、态密度和声子谱进行了研究.形成焓为负值、弹性常数满足Born稳定性准则和声子谱无虚频等结果证实在0~20 GPa范围内3种相都能保持结构稳定.温度变化影响到晶胞体积,从而使体模量发生改变.3种Ge3 N4都属于半导体,Ge原子和N原子之间存在明显的s-p杂化现象.当压强增大时诱发了离域电子,从而使体系的带隙减小.本文还采用准谐近似对Ge3 N4的热力学性质进行了研究,结果表明,温度和压强对热膨胀系数、 熵、 热容、德拜温度和格林爱森参数产生了明显影响.m-Ge3 N4和t-Ge3 N4的热膨胀系数分别为o-Ge3 N4的3倍和2倍.t-Ge3 N4和o-Ge3 N4的晶格谐振频率基本不受温度的影响.%Applying the ab initio pseudo-potential technique, we had predicted the lattice structures, density of states, phonon dispersion curves of the recently-discovered tetragonal, monoclinic and orthorhombic phases of Ge3 N4. The negative formation enthalpy, the satisfactory of Born ' s stability criteria and no imaginary frequency can be seen in the phonon dispersion curves proof that the three Ge3 N4 polymorphs can retain their stabilities in the pressure range of 0―20 GPa. The temperature affects the cell volume, thereby decreasing the bulk modulus. The band gaps show that Ge3 N4 are semiconductors, while obvious s-p hybridizations can be seen in the density of states. The band gaps decrease with applied pressure, which is due mainly to the generation of non-local electrons. Then, the quasi-harmonic approximation is used to study the thermodynamic properties of Ge3 N4. The results show that the thermal expansion coefficient, entropy, heat capacity, Debye temperature and Grüneisen parameter are significantly affected by both temperature and pressure. The thermal expansions of m-Ge3 N4 and t-Ge3 N4 are three and two times greater than that of

  4. Effects of the position of galactose units to Zn(II) phthalocyanine on the uptake and photodynamic activity towards breast cancer cells

    Science.gov (United States)

    Mantareva, V.; Kril, A.; Angelov, I.; Dimitrov, R.; Borisova, E.; Avramov, L.

    2012-06-01

    Zn(II)-phthalocyanines with tetra-substitution of D-galactose group on non-peripheral (nGalPc) and peripheral (pGalPc) positions have been studied as photodynamic sensitizers. The both complexes are water-soluble and highly aggregated in water and cell culture medium. The non-peripheral galactose units attached to the phthalocyanine macrocycle (nGalPc) lead to far red shift of absorbance maximum at 703 nm as compared to peripherally substituted pGalPc with maximum at 683 nm. The fluorescence maxima of the studied GalPcs were red shifted (8-14 nm) depending on the used solvent as compared to the absorption maxima. The relatively low fluorescence quantum yields in dimethylsulfoxide (0.06 for nGalPc and 0.21 for pGalPc) were determined. The singlet oxygen generation was determined with lower quantum yield for pGalPc (0.21) as compared to nGalPc (0.38). The lack of dark toxicity towards breast cancer cell line (MCF-7) in wide concentration range (0.125 - 10 μM) was observed. The uptake into the tumor cells and the subcellular localization in MCF-7 cells were determined with higher accumulation for pGalPc, compared to nGalPc. The in vitro photodynamic activity of GalPcs towards breast cancer cells was investigated for different dye concentrations and soft light parameters of 635 nm irradiation. The antitumor activity of nGalPc was superior to the pGalPc-induced cytotoxicity, due to higher generation of singlet oxygen and other reactive oxygen species.

  5. Manufacture of Clinical-Grade Human Clonal Mesenchymal Stem Cell Products from Single Colony Forming Unit-Derived Colonies Based on the Subfractionation Culturing Method.

    Science.gov (United States)

    Yi, TacGhee; Kim, Si-na; Lee, Hyun-Joo; Kim, Junghee; Cho, Yun-Kyoung; Shin, Dong-Hee; Tak, Sun-Ji; Moon, Sun-Hwa; Kang, Ji-Eun; Ji, In-Mi; Lim, Huyn-Ja; Lee, Dong-Soon; Jeon, Myung-Shin; Song, Sun U

    2015-12-01

    Stem cell products derived from mesenchymal stem cells (MSCs) have been widely used in clinical trials, and a few products have been already commercialized. However, the therapeutic effects of clinical-grade MSCs are still controversial owing to mixed results from recent clinical trials. A potential solution to overcome this hurdle may be to use clonal stem cells as the starting cell material to increase the homogeneity of the final stem cell products. We have previously developed an alternative isolation and culture protocol for establishing a population of clonal MSCs (cMSCs) from single colony forming unit (CFU)-derived colonies. In this study, we established a good manufacturing practice (GMP)-compatible procedure for the clinical-grade production of human bone marrow-derived cMSCs based on the subfractionation culturing method. We optimized the culture procedures to expand and obtain a clonal population of final MSC products from single CFU-derived colonies in a GMP facility. The characterization results of the final cMSC products met our preset criteria. Animal toxicity tests were performed in a good laboratory practice facility, and showed no toxicity or tumor formation in vivo. These tests include single injection toxicity, multiple injection toxicity, biodistribution analysis, and tumorigenicity tests in vivo. No chromosomal abnormalities were detected by in situ karyotyping using oligo-fluorescence in situ hydridization (oligo-FISH), providing evidence of genetic stability of the clinical-grade cMSC products. The manufacture and quality control results indicated that our GMP methodology could produce sufficient clonal population of MSC products from a small amount of bone marrow aspirate to treat a number of patients.

  6. SSH2S: Hydrogen storage in complex hydrides for an auxiliary power unit based on high temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Baricco, Marcello; Bang, Mads; Fichtner, Maximilian; Hauback, Bjorn; Linder, Marc; Luetto, Carlo; Moretto, Pietro; Sgroi, Mauro

    2017-02-01

    The main objective of the SSH2S (Fuel Cell Coupled Solid State Hydrogen Storage Tank) project was to develop a solid state hydrogen storage tank based on complex hydrides and to fully integrate it with a High Temperature Proton Exchange Membrane (HT-PEM) fuel cell stack. A mixed lithium amide/magnesium hydride system was used as the main storage material for the tank, due to its high gravimetric storage capacity and relatively low hydrogen desorption temperature. The mixed lithium amide/magnesium hydride system was coupled with a standard intermetallic compound to take advantage of its capability to release hydrogen at ambient temperature and to ensure a fast start-up of the system. The hydrogen storage tank was designed to feed a 1 kW HT-PEM stack for 2 h to be used for an Auxiliary Power Unit (APU). A full thermal integration was possible thanks to the high operation temperature of the fuel cell and to the relative low temperature (170 °C) for hydrogen release from the mixed lithium amide/magnesium hydride system.

  7. Semiempirical and DFT computations of the influence of Tb(III) dopant on unit cell dimensions of cerium(III) fluoride.

    Science.gov (United States)

    Shyichuk, Andrii; Runowski, Marcin; Lis, Stefan; Kaczkowski, Jakub; Jezierski, Andrzej

    2015-01-30

    Several computational methods, both semiempirical and ab initio, were used to study the influence of the amount of dopant on crystal cell dimensions of CeF3 doped with Tb(3+) ions (CeF3 :Tb(3+) ). AM1, RM1, PM3, PM6, and PM7 semiempirical parameterization models were used, while the Sparkle model was used to represent the lanthanide cations in all cases. Ab initio calculations were performed by means of GGA+U/PBE projector augmented wave density functional theory. The computational results agree well with the experimental data. According to both computation and experiment, the crystal cell parameters undergo a linear decrease with increasing amount of the dopant. The computations performed using Sparkle/PM3 and DFT methods resulted in the best agreement with the experiment with the average deviation of about 1% in both cases. Typical Sparkle/PM3 computation on a 2×2×2 supercell of CeF3:Tb3+ lasted about two orders of magnitude shorter than the DFT computation concerning a unit cell of this material. © 2014 Wiley Periodicals, Inc.

  8. Mixed-valence molecular four-dot unit for quantum cellular automata: Vibronic self-trapping and cell-cell response

    Energy Technology Data Exchange (ETDEWEB)

    Tsukerblat, Boris, E-mail: tsuker@bgu.ac.il, E-mail: andrew.palii@uv.es [Ben-Gurion University of the Negev, Beer-Sheva (Israel); Palii, Andrew, E-mail: tsuker@bgu.ac.il, E-mail: andrew.palii@uv.es [Institute of Applied Physics, Academy of Sciences of Moldova, Kishinev (Moldova, Republic of); Clemente-Juan, Juan Modesto; Coronado, Eugenio [Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Paterna (Spain)

    2015-10-07

    Our interest in this article is prompted by the vibronic problem of charge polarized states in the four-dot molecular quantum cellular automata (mQCA), a paradigm for nanoelectronics, in which binary information is encoded in charge configuration of the mQCA cell. Here, we report the evaluation of the electronic levels and adiabatic potentials of mixed-valence (MV) tetra-ruthenium (2Ru(II) + 2Ru(III)) derivatives (assembled as two coupled Creutz-Taube complexes) for which molecular implementations of quantum cellular automata (QCA) was proposed. The cell based on this molecule includes two holes shared among four spinless sites and correspondingly we employ the model which takes into account the two relevant electron transfer processes (through the side and through the diagonal of the square) as well as the difference in Coulomb energies for different instant positions of localization of the hole pair. The combined Jahn-Teller (JT) and pseudo JT vibronic coupling is treated within the conventional Piepho-Krauzs-Schatz model adapted to a bi-electronic MV species with the square-planar topology. The adiabatic potentials are evaluated for the low lying Coulomb levels in which the antipodal sites are occupied, the case just actual for utilization in mQCA. The conditions for the vibronic self-trapping in spin-singlet and spin-triplet states are revealed in terms of the two actual transfer pathways parameters and the strength of the vibronic coupling. Spin related effects in degrees of the localization which are found for spin-singlet and spin-triplet states are discussed. The polarization of the cell is evaluated and we demonstrate how the partial delocalization caused by the joint action of the vibronic coupling and electron transfer processes influences polarization of a four-dot cell. The results obtained within the adiabatic approach are compared with those based on the numerical solution of the dynamic vibronic problem. Finally, the Coulomb interaction between

  9. 不规则单斜地层中磁弹性剪切波的色散方程%Dispersion Equation of Magnetoelastic Shear Waves in an Irregular Monoclinic Layer

    Institute of Scientific and Technical Information of China (English)

    A·查托帕答雅; S·古普塔; S·A·萨胡; A·K·辛格; 黄雅意

    2011-01-01

    The propagation of horizontally polarised shear waves in an internal magnetoelastic monoclinic stratum with irregularity in lower interface was studied. The stratum was sandwiched between two magnetoelastic monoclinic semi-infinite media. Dispersion equation was obtained in closed form. In absence of magnetic field and irregularity of the medium, the dispersion equation agrees with the equation of classical case in three layered media. The effect of magnetic field and size of irregularity on the phase velocity has been depicted by means of graphs.%在内夹磁弹性单斜地层中,下界面不规则变化时,研究水平偏振剪切波的传播,该地层夹在两个半无限磁弹性单斜介质之间,得到了闭式的色散方程.不计磁场及介质界面的不规则性,该色散方程与三层介质中经典方程相一致.图示了磁场和界面不规则深度对相速度的影响.

  10. Modulating PCBM-Acceptor Crystallinity and Organic Solar Cell Performance by Judiciously Designing Small-Molecule Mainchain End-Capping Units.

    Science.gov (United States)

    Jiang, Bo; Yao, Jiannian; Zhan, Chuanlang

    2016-10-05

    In this article, we report that the bulk-size and electron-donating/electron-accepting nature of moieties, which are end-capping onto small-molecule donor mainchain, not only modulate the donor's absorption, molecular frontier orbitals, and phase ordering, but also effectively tune the PC71BM-acceptor phase crystallinity. Compared to the electron-deficient trifluoromethyl (SM-CF3) units on the diketopyrrolopyrrole (DPP) small molecule mainchain ends, the electron-rich methoxyl (SM-OCH3) units ending on the same mainchain help improve the PC71BM-acceptor phase short-range ordering. As a result, the -OCH3 capping small-molecule displays larger short-circuit current density (Jsc) when blended with PC71BM (10.72 ± 0.22 vs. 16.15 ± 0.53 mA/cm(2)). However, the electron-donating nature of -OCH3 raises the donor HOMO level, which leads to a quite small open-circuit voltage (Voc) (0.624 vs. 0.881 V). Replacement of the -OCH3 with the large and weak electron-donating aromatic carbazolyl (SM-Cz) ones affords the small molecule of SM-Cz. The SM-Cz:PC71BM system affords a high Voc of 0.846 V and a large Jsc of 13.33 ± 0.34 mA/cm(2) after thermal annealing, and hence gives a larger power conversion efficiency (PCE) of 6.26 ± 0.13%, which is among the top values achieved so far from the DPP molecules. Taken together, these results demonstrate that engineering the end-capping units on small-molecule donor mainchain can effectively modulate the organic solar cell performance.

  11. Mourning of professionals in a hematopoietic stem cell transplantation unit Luto de profissionais em uma unidade de transplante de células-tronco hematopoéticas

    Directory of Open Access Journals (Sweden)

    Renata Pereira Rodrigues

    2012-05-01

    Full Text Available Introduction: The transplant of hematopoietic stem cells (HSCT is a procedure that can either retrieve the patient's life or lead him/her to death. No avoiding death can bring to the professionals the experience of mourning and their limits. Objective: To understand the process of mourning experienced by health professionals who work in a HSCT Unit. Materials and Methods: This is a clinical-qualitative study with eight professionals from a HSCT Unit. Semi structured interviews were performed and the material was subjected to qualitative content analysis. Results: The results indicate that the professionals in a HSCT Unit experience the mourning when they observe slow processes of death and when the patient’s suffering becomes too intense. Conclusion: The process of mourning of the professional is still not recognized and there is little opportunity for public expression to facilitate the experience of mourning.Introdução: O transplante de células-tronco hematopoéticas (TCTH é um procedimento que pode tanto recuperar a vida do paciente quanto conduzi-lo ao óbito. Não conseguir evitar a morte pode trazer ao profissional à vivência do luto e de seus limites. Objetivo: Compreender o processo de luto vivenciado pelos profissionais da saúde de uma Unidade TCTH. Materiais e Métodos: Trata-se de um estudo clínico-qualitativo de 8 profissionais de uma unidade de TCTH. Foram realizadas entrevistas semidirigidas e o material foi submetido à análise qualitativa de conteúdo. Resultados: Os resultados indicam que os profissionais de uma unidade de TCTH vivenciam o luto quando verificam processos lentos de morte e quando o sofrimento do paciente se torna muito intenso. Conclusão: O processo do luto do profissional ainda não é reconhecido e existe pouca oportunidade de expressão pública para facilitar a vivência desse luto.

  12. First Principles Calculation of Elastic Constants of Monoclinic HfO2 Thin Film%单斜相HfO2薄膜弹性常数的第一性原理计算

    Institute of Scientific and Technical Information of China (English)

    蔺玲; 邵淑英; 李静平

    2013-01-01

    用电子束蒸发沉积在K9玻璃基底上镀制HfO2薄膜,沉积温度为200℃,蒸发速率为0.03 nm/s.由X射线衍射谱可知薄膜出现明显结晶,且为单斜相和正交相混合结构,其中单斜相占明显优势.用Jade5软件分析得到单斜相HfO2的晶格常数a,b,c以及晶格矢量a和c之间的夹角β.基于得到的晶格常数建立了单斜相HfO2薄膜的晶体结构模型.同时建立固态单斜相HfO2的晶体结构模型进行对比.通过密度泛函理论(DFT)框架下的平面超软赝势法,采用两种不同的交换关联函数:局域密度近似(LDA)中的CA-PZ和广义梯度近似(GGA)中的质子平衡方程(PBE),计算了薄膜态和固态单斜晶相HfO2的弹性刚度系数矩阵Gij和弹性柔度系数矩阵Sij,Reuss模型、Voigt模型和Hill理论下的体积模量和剪切模量,材料平均杨氏模量和泊松比.此外还计算得到薄膜态和固态单斜晶相HfO2在不同方向上的杨氏模量.%HfO2 films are deposited by electron beam evaporation at a deposition rate of 0.03 nm/s and deposition temperature of 200 ℃ on K9 glass substrates. The films are observed to show a mixed structure of monoclinic and orthorhombic phase through X-ray diffraction and monoclinic phase is of obvious advantages. The structure parameters a, b, c and angel β of monoclinic HfO2 films are obtained using Jade5 software, based on which the crystal structure model is built. While solid crystal monoclinic HfO2 model is built to compare with the thin film one. Elastic stiffness constants of monoclinic HfO2 thin film and solid crystal are investigated using the plane waves ultrasoft pseudopotential technique based on the density functional theory (DFT) under two different exchange correlation functions of local density approximation (LDA) CA-PZ and generalized gradient approximation (GGA) PBE. Reuss, Voigt and Hill theories are used to estimate the bulk, shear and average Young's moduli and Possion ratio for polycrystalline HfO2

  13. High-Temperature Superconductivity in Single-Unit-Cell FeSe Films on Anatase TiO_{2}(001).

    Science.gov (United States)

    Ding, Hao; Lv, Yan-Feng; Zhao, Kun; Wang, Wen-Lin; Wang, Lili; Song, Can-Li; Chen, Xi; Ma, Xu-Cun; Xue, Qi-Kun

    2016-08-05

    We report on the observation of high-temperature (T_{c}) superconductivity and magnetic vortices in single-unit-cell FeSe films on anatase TiO_{2}(001) substrate by using scanning tunneling microscopy. A systematic study and engineering of interfacial properties has clarified the essential roles of substrate in realizing the high-T_{c} superconductivity, probably via interface-induced electron-phonon coupling enhancement and charge transfer. By visualizing and tuning the oxygen vacancies at the interface, we find their very limited effect on the superconductivity, which excludes interfacial oxygen vacancies as the primary source for charge transfer between the substrate and FeSe films. Our findings have placed severe constraints on any microscopic model for the high-T_{c} superconductivity in FeSe-related heterostructures.

  14. Interface-Induced High-Temperature Superconductivity in Single Unit-Cell FeSe Films on SrTiO3

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-Yan; CHANG Kai; WEN Jing; SONG Can-Li; HE Ke; JIA Jin-Feng; JI Shuai-Hua; WANG Ya-Yu; WANG Li-Li; CHEN Xi; MA Xu-Cun; LI Zhi; XUE Qi-Kun; ZHANG Wen-Hao; ZHANG Zuo-Cheng; ZHANG Jin-Song; LI Wei; DING Hao; OU Yun-Bo; DENG Peng

    2012-01-01

    We report high transition temperature superconductivity in one unit-cell (UC) thick FeSe films grown on a Seetched SrTiO3 (001) substrate by molecular beam epitaxy (MBE).A superconducting gap as large as 20 meV and the magnetic field induced vortex state revealed by in situ scanning tunneling microscopy (STM) suggest that the superconductivity of the 1 UC FeSe films could occur around 77K.The control transport measurement shows that the onset superconductivity temperature is well above 50K.Our work not only demonstrates a powerful way for finding new superconductors and for raising Tc,but also provides a well-defined platform for systematic studies of the mechanism of unconventional superconductivity by using different superconducting materials and substrates.

  15. Using infrared thermography to determine the presence and correct placement of grouted cells in single-width concrete masonry unit (CMU) walls

    Science.gov (United States)

    Stockton, Gregory R.; Allen, Lee R.

    1999-03-01

    Determining the placement of reinforcing grout in single-width CMU (Concrete Masonry Unit) walls has, in the past, been a painstaking and destructive undertaking. Usually, a test is performed because -- by accident -- missing cells are discovered when a wall penetration is retrofitted or change order is executed, requiring that the wall be opened. Often, a hammer or hammer drill is used to punch holes where the grouting is supposed to be. The test results are used to extrapolate the extent of the problem. This method falls short, since the sample is so small, that only outright fraud can be found, and excess grouting cannot be determined. This paper discusses the results of a joint effort between Stockton Infrared Thermographic Services, Inc. (SITS) and Allen Applied Infrared Technology, Inc. (AAIT) to produce a methodology for using non-destructive infrared thermography to ensure that the design specifications are being met.

  16. 电解单元槽电压测量偏差的解决方案%Solutions to measurement deviation of voltage of electrolysis unit cell

    Institute of Scientific and Technical Information of China (English)

    路恩勇

    2015-01-01

    通过理论分析和计算,结合实际情况提出了增加引线消除铜排电压和改接线降低铜排电压这两种减小电解槽单元槽电压测量偏差的解决方案,并分析了每种方案的优缺点。%On the basis of theoretical analysis , calculation and practical situations , two solutions to the measurement deviation of voltage of electrolysis unit cells , i.e.adding lead wires to eliminate copper busbar voltage and changing connection wires to reduce copper busbar voltage were proposed .Advantages and disadvantages of the two solutions were analyzed .

  17. Synthesis of organic photosensitizers containing dithienogermole and thiadiazolo[3,4-c]pyridine units for dye-sensitized solar cells.

    Science.gov (United States)

    Adachi, Yohei; Ooyama, Yousuke; Shibayama, Naoyuki; Ohshita, Joji

    2016-09-21

    Dithienogermole (DTG) is a germanium-bridged bithiophene system that has been applied as a building unit of conjugated materials for organic electronic devices, including organic photovoltaics and organic light emitting diodes. However, DTG has not been used as a component of sensitizers for dye-sensitized solar cells (DSSCs). In this work, we have synthesized three D-π-A-π-A type sensitizers containing DTG and thiadiazolo[3,4-c]pyridine (PTz). We expected that combining DTG and a strong acceptor PTz would give rise to a strong absorption in the visible region. In addition, we introduced bulky 2-ethylhexyl groups on the germanium atom to prevent dye aggregation on TiO2 films. Three DTG-containing dyes with different anchor units were synthesized and their optical/electrochemical properties were investigated. The DTG-containing dyes exhibited broad and strong absorption bands around 600 nm on TiO2. We fabricated DSSCs based on the DTG-containing dyes. The onsets of incident photon to current conversion efficiency (IPCE) spectra reached 900 nm and a maximal power conversion efficiency of 2.76% was achieved.

  18. Theoretical Study of the π-Bridge Influence with Different Units of Thiophene and Thiazole in Coumarin Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Rody Soto-Rojo

    2016-01-01

    Full Text Available Eight coumarin derivative dyes were studied by varying the π-bridge size with different thiophene and thiazole units for their potential use in dye-sensitized solar cells (DSSC. Geometry optimization, the energy levels and electron density of the Highest Occupied Molecular Orbital and the Lowest Unoccupied Molecular Orbital, and ultraviolet-visible absorption spectra were calculated by Density Functional Theory (DFT and Time-Dependent-DFT. All molecular properties were analyzed to decide which dye was the most efficient. Furthermore, chemical reactivity parameters, such as chemical hardness, electrophilicity index, and electroaccepting power, were obtained and analyzed, whose values predicted the properties of the dyes in addition to the rest of the studied molecular properties. Our calculations allow us to qualitatively study dye molecules and choose the best for use in a DSSC. The effects of π-bridges based on thiophenes, thiazoles, and combinations of the two were reviewed; dyes with three units mainly of thiazole were chosen as the best photosensitizers for DSSC.

  19. Generating Units

    Data.gov (United States)

    Department of Homeland Security — Generating Units are any combination of physically connected generators, reactors, boilers, combustion turbines, and other prime movers operated together to produce...

  20. Identification of 2127 new HLA class I alleles in potential stem cell donors from Germany, the United States and Poland.

    Science.gov (United States)

    Hernández-Frederick, C J; Giani, A S; Cereb, N; Sauter, J; Silva-González, R; Pingel, J; Schmidt, A H; Ehninger, G; Yang, S Y

    2014-03-01

    We describe 2127 new human leukocyte antigen (HLA) class I alleles found in registered stem cell donors. These alleles represent 28.9% of the currently known class I alleles. Comparing new allele sequences to homologous sequences, we found 68.1% nonsynonymous nucleotide substitutions, 28.9% silent mutations and 3.0% nonsense mutations. Many substitutions occurred at positions that have not been known to be polymorphic before. A large number of HLA alleles and nucleotide variations underline the extreme diversity of the HLA system. Strikingly, 156 new alleles were found not only multiple times, but also in carriers of various parentage, suggesting that some new alleles are not necessarily rare. Moreover, new alleles were found especially often in minority donors. This emphasizes the benefits of specifically recruiting such groups of individuals.

  1. Integrative genome-wide gene expression profiling of clear cell renal cell carcinoma in Czech Republic and in the United States.

    Directory of Open Access Journals (Sweden)

    Magdalena B Wozniak

    Full Text Available Gene expression microarray and next generation sequencing efforts on conventional, clear cell renal cell carcinoma (ccRCC have been mostly performed in North American and Western European populations, while the highest incidence rates are found in Central/Eastern Europe. We conducted whole-genome expression profiling on 101 pairs of ccRCC tumours and adjacent non-tumour renal tissue from Czech patients recruited within the "K2 Study", using the Illumina HumanHT-12 v4 Expression BeadChips to explore the molecular variations underlying the biological and clinical heterogeneity of this cancer. Differential expression analysis identified 1650 significant probes (fold change ≥2 and false discovery rate <0.05 mapping to 630 up- and 720 down-regulated unique genes. We performed similar statistical analysis on the RNA sequencing data of 65 ccRCC cases from the Cancer Genome Atlas (TCGA project and identified 60% (402 of the downregulated and 74% (469 of the upregulated genes found in the K2 series. The biological characterization of the significantly deregulated genes demonstrated involvement of downregulated genes in metabolic and catabolic processes, excretion, oxidation reduction, ion transport and response to chemical stimulus, while simultaneously upregulated genes were associated with immune and inflammatory responses, response to hypoxia, stress, wounding, vasculature development and cell activation. Furthermore, genome-wide DNA methylation analysis of 317 TCGA ccRCC/adjacent non-tumour renal tissue pairs indicated that deregulation of approximately 7% of genes could be explained by epigenetic changes. Finally, survival analysis conducted on 89 K2 and 464 TCGA cases identified 8 genes associated with differential prognostic outcomes. In conclusion, a large proportion of ccRCC molecular characteristics were common to the two populations and several may have clinical implications when validated further through large clinical cohorts.

  2. UNIT, TIBET.

    Science.gov (United States)

    Louisiana Arts and Science Center, Baton Rouge.

    THE UNIT OF STUDY DESCRIBED IN THIS BOOKLET DEALS WITH THE GEOGRAPHY AND HISTORY OF TIBET. THE UNIT COVERS SOME OF THE GENERAL FEATURES OF THE COUNTRY AND THEIR EFFECT UPON THE LIVES OF THE TIBETAN PEOPLE. DISCUSSION QUESTIONS ARE INSERTED TO STIMULATE THOUGHT. THE RELIGION OF TIBET IS DISCUSSED IN RELATION TO ITS INFLUENCE ON THE ART AND CULTURE…

  3. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 115: AREA 25 TEST CELL A FACILITY, NEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2006-03-01

    This Closure Report (CR) describes the activities performed to close CAU 115, Area 25 Test Cell A Facility, as presented in the NDEP-approved SAFER Plan (NNSA/NSO, 2004). The SAFER Plan includes a summary of the site history, process knowledge, and closure standards. This CR provides a summary of the completed closure activities, documentation of waste disposal, and analytical and radiological data to confirm that the remediation goals were met and to document final site conditions. The approved closure alternative as presented in the SAFER Plan for CAU 115 (NNSA/NSO, 2004) was clean closure; however, closure in place was implemented under a Record of Technical Change (ROTC) to the SAFER Plan when radiological surveys indicated that the concrete reactor pad was radiologically activated and could not be decontaminated to meet free release levels. The ROTC is included as Appendix G of this report. The objectives of closure were to remove any trapped residual liquids and gases, dispose regulated and hazardous waste, decontaminate removable radiological contamination, demolish and dispose aboveground structures, remove the dewar as a best management practice (BMP), and characterize and restrict access to all remaining radiological contamination. Radiological contaminants of concern (COCs) included cobalt-60, cesium-137, strontium-90, uranium-234/235/236/238, and plutonium-239/240. Additional COCs included Resource Conservation and Recovery Act (RCRA) metals, polychlorinated biphenyls (PCBs), and asbestos.

  4. Transplanted bone marrow stromal cells protect neurovascular units and ameliorate brain damage in stroke-prone spontaneously hypertensive rats.

    Science.gov (United States)

    Ito, Masaki; Kuroda, Satoshi; Sugiyama, Taku; Maruichi, Katsuhiko; Kawabori, Masahito; Nakayama, Naoki; Houkin, Kiyohiro; Iwasaki, Yoshinobu

    2012-10-01

    This study was aimed to assess whether bone marrow stromal cells (BMSC) could ameliorate brain damage when transplanted into the brain of stroke-prone spontaneously hypertensive rats (SHR-SP). The BMSC or vehicle was stereotactically engrafted into the striatum of male SHR-SP at 8 weeks of age. Daily loading with 0.5% NaCl-containing water was started from 9 weeks. MRIs and histological analysis were performed at 11 and 12 weeks, respectively. Wistar-Kyoto rats were employed as the control. As a result, T2-weighted images demonstrated neither cerebral infarct nor intracerebral hemorrhage, but identified abnormal dilatation of the lateral ventricles in SHR-SP. HE staining demonstrated selective neuronal injury in their neocortices. Double fluorescence immunohistochemistry revealed that they had a decreased density of the collagen IV-positive microvessels and a decreased number of the microvessels with normal integrity between basement membrane and astrocyte end-feet. BMSC transplantation significantly ameliorated the ventricular dilatation and the breakdown of neurovascular integrity. These findings strongly suggest that long-lasting hypertension may primarily damage neurovascular integrity and neurons, leading to tissue atrophy and ventricular dilatation prior to the occurrence of cerebral stroke. The BMSC may ameliorate these damaging processes when directly transplanted into the brain, opening the possibility of prophylactic medicine to prevent microvascular and parenchymal-damaging processes in hypertensive patients at higher risk for cerebral stroke.

  5. Crumpled rGO-supported Pt-Ir bifunctional catalyst prepared by spray pyrolysis for unitized regenerative fuel cells

    Science.gov (United States)

    Kim, In Gyeom; Nah, In Wook; Oh, In-Hwan; Park, Sehkyu

    2017-10-01

    Three-dimensional (3D) crumpled reduced graphene oxide supported Pt-Ir alloys that served as bifunctional oxygen catalysts for use in untized regenerative fuel cells were synthesized by a facile spray pyrolysis method. Pt-Ir catalysts supported on rGO (Pt-Ir/rGOs) were physically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) to observe change in composition by heat treatment, alloying, and morphological transition of the catalysts. Their catalytic activities and stabilities for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) conditions were electrochemically investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), potential cycling and hold tests on the rotating disk electrode (RDE). Pt-Ir/rGO with no post heat-treatment (Pt-Ir/rGO_NP) showed a lower activity for ORR and OER although metal nanoparticles decorated on the support are relatively small. However, Pt-Ir/rGO showed remarkably enhanced activity following heat treatment, depending on temperature. Pt-Ir/rGO heat-treated at 600 °C after spray pyrolysis (Pt-Ir/rGO_P600) exhibited a higher activity and stability than a commercially available Pt/C catalyst kept under the ORR condition, and it also revealed a comparable OER activity and durability versus the commercial unsupported Ir catalyst.

  6. An Applied Study on the Decontamination and Decommissioning of Hot Cell Facilities in the United States and Comparison with the Studsvik Facility for Solid and Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Geoff; Rusch, Chris [NAC International, Atlanta, GA (United States)

    2006-07-15

    Dismantlement occurred during Phase II. The activities included: a. Dismantlement of the building structure surrounding the hot cells and then finally dismantlement of the hot cell block b. Soil remediation c. Handling and disposal of decommissioning wastes d. Confirmatory surveys 3. Final site release occurred during Phase III. 4. The final activity which occurred substantially after Phases II and III were complete was the shipment of the IFM to a DOE facility. The HCF and HM structures are approximately the same size on a volumetric basis. The volume of the HM hot cells is about 12 percent greater than at HCF but the HCF had 27 percent more surface area due to the existence of three separate cells. Of potential importance is that the contamination levels on the hot cell surfaces were not equal. The HCF facility was highly contaminated from such activities as band-sawing irradiated high temperature gas cooled reactor fuel. On these grounds it might be expected that the HCF actual costs would be higher than HM estimates. However, a factor of almost nine times higher seems to be exceptional. The very large difference in fact stems from a number of special circumstances at HCF that need to be backed-out of a cost comparison in order to make it meaningful. One special requirement was the removal and safe management of irradiated fuel material, including high enriched uranium. Another cost related to maintenance of the building before decommissioning could commence. The costs of waste disposal also vary substantially, in terms of unit costs and the proportion of dismantling waste that needs to be sentenced to a radioactive waste repository. The available information for HM has been evaluated and compared, to the extent possible, with the HCF decommissioning costs and other selected NAC derived decommissioning cost benchmarks. In summary the main conclusions for the HM decommissioning cost estimate are as follows: Theoretical estimates of planning and other support activities can

  7. Neighborhood-level socioeconomic determinants impact outcomes in nonsmall cell lung cancer patients in the Southeastern United States.

    Science.gov (United States)

    Erhunmwunsee, Loretta; Joshi, Mary-Beth M; Conlon, Debbi H; Harpole, David H

    2012-10-15

    Studies examining the impact of lower socioeconomic status (SES) on the outcomes of patients with nonsmall cell lung cancer (NSCLC) are inconsistent. The objective of this study was to clearly elucidate the association between SES, education, and clinical outcomes among patients with NSCLC. The study population was derived from a consecutive, retrospective cohort of patients with NSCLC who received treatment within the Duke Health System between 1995 and 2007. SES determinants were based on the individual's census tract and corresponding 2000 Census data. Determinants included the percentage of the population living below poverty, the median household income, and the percentages of residents with at least a high school diploma and at least a bachelor's degree. The SES and educational variables were divided into quartiles. Statistical comparisons were performed using the 25th and 75th percentiles. Individuals who resided in areas with a low median household income or in which a high percentage of residents were living below the poverty line had a shorter cancer-specific 6-year survival than individuals who resided in converse areas (P = .0167 and P = .0067, respectively). Those living in areas in which a higher percentage of residents achieved a high school diploma had improved disease outcomes compared with those living in areas in which a lower percentage attained a high school diploma (P = .0033). A survival advantage also was observed for inhabitants of areas in which a higher percentage of residents attained a bachelor's degree (P = .0455). Low SES was identified as an independent prognostic factor for poor survival in patients with both early and advanced stage NSCLC. Patients who lived in areas with high poverty levels, low median incomes, and low education levels had worse mortality. Copyright © 2012 American Cancer Society.

  8. Use of Stereotactic Radiosurgery for Brain Metastases From Non-Small Cell Lung Cancer in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Halasz, Lia M., E-mail: lhalasz@uw.edu [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Harvard Radiation Oncology Program, Harvard Medical School, Boston, Massachusetts (United States); Weeks, Jane C.; Neville, Bridget A.; Taback, Nathan [Division of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Punglia, Rinaa S. [Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States)

    2013-02-01

    Purpose: The indications for treatment of brain metastases from non-small cell lung cancer (NSCLC) with stereotactic radiosurgery (SRS) remain controversial. We studied patterns, predictors, and cost of SRS use in elderly patients with NSCLC. Methods and Materials: Using the Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database, we identified patients with NSCLC who were diagnosed with brain metastases between 2000 and 2007. Our cohort included patients treated with radiation therapy and not surgical resection as initial treatment for brain metastases. Results: We identified 7684 patients treated with radiation therapy within 2 months after brain metastases diagnosis, of whom 469 (6.1%) cases had billing codes for SRS. Annual SRS use increased from 3.0% in 2000 to 8.2% in 2005 and varied from 3.4% to 12.5% by specific SEER registry site. After controlling for clinical and sociodemographic characteristics, we found SRS use was significantly associated with increasing year of diagnosis, specific SEER registry, higher socioeconomic status, admission to a teaching hospital, no history of participation in low-income state buy-in programs (a proxy for Medicaid eligibility), no extracranial metastases, and longer intervals from NSCLC diagnosis. The average cost per patient associated with radiation therapy was 2.19 times greater for those who received SRS than for those who did not. Conclusions: The use of SRS in patients with metastatic NSCLC increased almost 3-fold from 2000 to 2005. In addition, we found significant variations in SRS use across SEER registries and socioeconomic quartiles. National practice patterns in this study suggested both a lack of consensus and an overall limited use of the approach among elderly patients before 2008.

  9. Picometer registration of zinc impurity states in Bi2Sr2CaCu2O8+δ for phase determination in intra-unit-cell Fourier transform STM

    Science.gov (United States)

    Hamidian, M. H.; Firmo, I. A.; Fujita, K.; Mukhopadhyay, S.; Orenstein, J. W.; Eisaki, H.; Uchida, S.; Lawler, M. J.; Kim, E.-A.; Davis, J. C.

    2012-05-01

    Direct visualization of electronic-structure symmetry within each crystalline unit cell is a new technique for complex electronic matter research (Lawler et al 2010 Nature 466 347-51, Schmidt et al 2011 New J. Phys. 13 065014, Fujita K et al 2012 J. Phys. Soc. Japan 81 011005). By studying the Bragg peaks in Fourier transforms of electronic structure images and particularly by resolving both the real and imaginary components of the Bragg amplitudes, distinct types of intra-unit-cell symmetry breaking can be studied. However, establishing the precise symmetry point of each unit cell in real space is crucial in defining the phase for such a Bragg-peak Fourier analysis. Exemplary of this challenge is the high-temperature superconductor Bi2Sr2CaCu2O8+δ for which the surface Bi atom locations are observable, while it is the invisible Cu atoms that define the relevant CuO2 unit-cell symmetry point. Here we demonstrate, by imaging with picometer precision the electronic impurity states at individual Zn atoms substituted at Cu sites, that the phase established using the Bi lattice produces a ˜2%(2π) error relative to the actual Cu lattice. Such a phase assignment error would not diminish reliability in the determination of intra-unit-cell rotational symmetry breaking at the CuO2 plane (Lawler et al 2010 Nature 466 347-51, Schmidt et al 2011 New J. Phys. 13 065014, Fujita K et al 2012 J. Phys. Soc. Japan 81 011005). Moreover, this type of impurity atom substitution at the relevant symmetry site can be of general utility in phase determination for the Bragg-peak Fourier analysis of intra-unit-cell symmetry.

  10. Picometer registration of zinc impurity states in Bi2Sr2CaCu2O8+delta for phase determination in intra-unit-cell Fourier transform STM

    OpenAIRE

    Hamidian, M. H.; Firmo, I. A.; Fujita, K.; Mukhopadhyay, S.(Saha Institute of Nuclear Physics, Kolkata, India); Orenstein, J. W.; Eisaki, H.; Uchida, S.; Lawler, M. J; Kim, E-A; Davis, J. C.

    2012-01-01

    Direct visualization of electronic-structure symmetry within each crystalline unit cell is a new technique for complex electronic matter research (Lawler et al 2010 Nature 466 347-51, Schmidt et al 2011 New J. Phys. 13 065014, Fujita K et al 2012 J. Phys. Soc. Japan 81 011005). By studying the Bragg peaks in Fourier transforms of electronic structure images and particularly by resolving both the real and imaginary components of the Bragg amplitudes, distinct types of intra-unit-cell symmetry ...

  11. Electrochemical characterization of IrO{sub 2}-Pt and RuO{sub 2}-Pt mixtures as bifunctional electrodes for unitized regenerative fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Escalante-Garcia, I.L.; Duron-Torres, S.M. [Univ. Autonoma de Zacatecas, Zacatecas (Mexico). Unidad Academica de Ciencias Quimicas; Cruz, J.C.; Arriaga-Hurtado, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Pedro Escobedo (Mexico)

    2010-07-15

    A unitized regenerative fuel cell (URFC) is a single electrochemical cell that has the potential to meet the required features of an idealized energy cycle whereby hydrogen can be produced from renewable energy sources. A URFC is a system which can operate as a polymer electrolyte water electrolyzer (PEMWE) or as a polymer electrolyte fuel cell (PEMFC). In the PEMWE mode, water is converted into hydrogen and oxygen by using electricity from solar or wind energy. In the PEMFC mode, the stored hydrogen and oxygen are supplied to generate electricity and water. Combining PEMWEs and PEMFCs remains a great challenge because several practical and structural features must be considered. The limiting reaction steps at the oxygen electrode for PEMFC or PEMWE are the oxygen reduction reaction (ORR) and the water oxidation reaction (OER), respectively. The high-efficiency therefore depends on the type of electrocatalysts and the capability of the oxygen electrode to operate under PEMFC or PEMWE conditions. As such, much research has gone into the development of a new oxygen electrode design for URFCs. Several bifunctional electrodes for OER and ORR were designed in this study using platinum (Pt) and iridium oxide (IrO{sub 2}) electrocatalysts or Pt and ruthenium oxide (RuO{sub 2}) supported electrocatalysts on Ebonex{sup R}. According to electrochemical characterization by CV, LV and EIS in aqueous 0.5 M H{sub 2}SO{sub 4}, IrO{sub 2}-Pt and RuO{sub 2}-Pt supported on Ebonex have high electrocatalytic properties for ORR and OER, indicating potential use in URFCs. IrO{sub 2} based electrodes were more stable than RuO{sub 2} based electrodes. 31 refs., 2 tabs., 6 figs.

  12. Advanced bifunctional electrocatalyst generated through cobalt phthalocyanine tetrasulfonate intercalated Ni2Fe-layered double hydroxides for a laminar flow unitized regenerative micro-cell

    Science.gov (United States)

    Zhong, Haihong; Tian, Ran; Gong, Xiaoman; Li, Dianqing; Tang, Pinggui; Alonso-Vante, Nicolas; Feng, Yongjun

    2017-09-01

    We fabricated a NiFeOx/CoNy-C nanocomposite derived from CoPcTs-intercalated Ni2Fe-layered double hydroxides (Ni2Fe-CoPcTs-LDH), which served as high-efficiency, low-cost, and long-durability bifunctional oxygen electrocatalyst in half-cell, and a H2-O2 laminar flow unitized regenerative micro-cell (LFURMC) in alkaline media. Based on the synergistic effect between Co-Ny and NiFeOx centers, the non-noble hybrid catalyst NiFeOx/CoNy-C achieves a ΔE (η@jOER,10 - η@jORR,-3) = 0.84 V in alkaline solution, outperforming the commercial Pt/C, and very close to that of IrOx/C. In the fuel cell mode, the performance of NiFeOx/CoNy-C with the maximum power density of 56 mW cm-2 is similar to that of Pt/C (63 mW cm-2) and IrOx/C (58 mW cm-2); in the electrolysis mode, the calculated maximum electrical power consumed on NiFeOx/CoNy-C (237 mW cm-2) is more than 3 times that on Pt/C (73 mW cm-2), similar with that of IrOx/C. More importantly, the NiFeOx/CoNy-C shows a remarkable stability in alternating modes in a LFURMC system.

  13. Novel monoclinic zirconolite in Bi{sub 2}O{sub 3}–CuO–Ta{sub 2}O{sub 5} ternary system: Phase equilibria, structural and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Tan, K.B., E-mail: tankb@science.upm.my [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Chon, M.P. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Khaw, C.C. [Department of Mechanical and Material Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Setapak, Kuala Lumpur (Malaysia); Zainal, Z.; Taufiq Yap, Y.H.; Tan, P.Y. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

    2014-04-01

    Highlights: • Novel BCT monoclinic zirconolite phase was prepared through solid state reaction. • Comprehensive study of reaction mechanism was performed by careful firing control. • Qualitative structural and phase analyses were conducted. • Electrical response in broad range of temperature and frequency was investigated. - Abstract: Synthesis of novel monoclinic zirconolite, Bi{sub 1.92}Cu{sub 0.08}(Cu{sub 0.3}Ta{sub 0.7}){sub 2}O{sub 7.06} (β-BCT) using solid state reaction had been finalised at the firing temperature of 900 °C over 24 h. The X–ray diffraction pattern of β-BCT was fully indexed on a monoclinic symmetry, space group, C2/c with lattice constants, a = 13.1052 (8), b = 7.6749 (5), c = 12.162 (6), α = γ = 90° and β = 101.32° (1), respectively. The reaction mechanism study indicated phase formation was greatly influenced by the reaction between intermediate bismuth tantalate binary phases and CuO at elevated temperatures. β-BCT was thermally stable up to a temperature of 900 °C and contained spherulite grains with sizes ranging from 1 to 14 μm. Electrical properties of this material were characterised over a broad temperature range covering temperatures from 10 K to 874 K. At the temperature of 304 K, two semicircles were discernible in complex Cole–Cole plot showing an insulating grain boundary with C{sub gb} = 6.63 × 10{sup −9} F cm{sup −1} and a bulk response capacitance, C{sub b} = 6.74 × 10{sup −12} F cm{sup −1}. The Power law frequency-dependent ac conductivity of β-BCT was apparent in three frequency regimes; a low–frequency plateau regime, a high-frequency plateau regime and a dispersive regime taking place in the temperature range of 220–576 K. The frequency-dependent ac conductivity of β-BCT with increasing temperature was attributed to the thermal activated electrical conduction mechanism within the structure.

  14. Transfusão de concentrado de hemácias na unidade de terapia intensiva Red blood cells transfusion in intensive care unit

    Directory of Open Access Journals (Sweden)

    Solange Emanuelle Volpato

    2009-12-01

    Full Text Available INTRODUÇÃO: A anemia é um problema comum na admissão dos pacientes nas unidades de terapia intensiva, sendo a prática de transfusão de concentrado de hemácias uma terapêutica freqüente. As causas de anemia em pacientes críticos que realizam transfusão de concentrado de hemácias são várias: perda aguda de sangue após trauma, hemorragia gastrointestinal, cirurgia, dentre outras. Atualmente, poucos estudos são disponibilizados sobre o uso de hemocomponentes em pacientes sob cuidados intensivos. Embora as transfusões sangüíneas sejam freqüentes em unidades de terapia intensiva, os critérios de manejo otimizados não são claramente definidos, não existindo, inclusive, guidelines específicos. OBJETIVOS: Analisar as indicações clínicas do uso do concentrado hemácia na unidade de terapia intensiva. MÉTODOS: Foram analisados os prontuários dos pacientes internados na unidade de terapia intensiva que realizaram transfusão de concentrado de hemácias no período de 1º de janeiro de 2005 a 31 de dezembro de 2005. O trabalho foi aceito pelo Comitê de Ética em Pesquisa da Universidade do Sul de Santa Catarina (UNISUL. RESULTADOS: A taxa de transfusão foi de 19,33%, tendo predomínio do gênero masculino. Prevalência de paciente com idade superior ou igual a 60 anos. A taxa de óbitos nos pacientes transfundidos com concentrado de hemácias foi de 38,22%. O critério de indicação de transfusão mais freqüente foi por baixa concentração de hemoglobina (78% com média da hemoglobina pré-transfusional de 8,11g/dl. CONCLUSÕES: Os diagnósticos pré-transfusão mais frequentes são politrauma e sepse/choque séptico. Baixa concentração de hemoglobina é o principal critério clínico com média pré-transfusional de 8,11g/dl.BACKGROUND: The anemia is a common problem upon admission of the patients in the intensive care unit being the red blood cell transfusion a frequent therapeutic. The causes of anemia in critical

  15. Turnley Unit

    Data.gov (United States)

    Federal Laboratory Consortium — Facilities at this unit include cattle working pens, hydraulic squeeze chute and electronic scale, a maintenance building, and four hay storage sheds. There is one...

  16. Operable Units

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of operable unit data from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different times and...

  17. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  18. Associations of risk factors with somatic cell count in bulk tank milk on organic and conventional dairy farms in the United States.

    Science.gov (United States)

    Cicconi-Hogan, K M; Gamroth, M; Richert, R; Ruegg, P L; Stiglbauer, K E; Schukken, Y H

    2013-06-01

    In the past decade, the demand for organic agricultural products has increased rapidly in the United States and worldwide. Milk quality research is of major interest to both consumers and dairy farmers alike. However, scientific data on milk quality, herd management methods, and animal welfare on organic farms in the United States has been lacking before the research from this study. The objective of this study was to evaluate the association of bulk tank milk somatic cell count (SCC) with management characteristics on organic and conventional dairy farms in New York, Oregon, and Wisconsin. Data from similarly sized organic farms (n=192), conventional nongrazing farms (n=64), and conventional grazing farms (n=36) were collected at a single farm visit. Of the 292 farms visited, 290 bulk tank milk samples were collected. Overall, no difference in SCC was observed between the conventional and organic grazing systems. Two models were created to assess the effects of various management and herd characteristics on the logarithmic transformation of the SCC (LSCC), one using data from all herds and one using data from organic herds only. From the total herd model, more grain fed per cow per day was negatively associated with LSCC, whereas a positive bulk tank culture for Staphylococcus aureus and years that a farmer reported being in the dairy business were both positively associated with LSCC. In the organic herd model, a seasonal effect indicated that LSCC tended to increase in the summer and decrease in the winter. Grain fed per cow per day, the use of anionic salts in transition-cow diets, the use of gloves during milking, and regular use of a quarantine unit at milking were all negatively associated with LSCC. Similar to the total herd model, a Staph. aureus-positive bulk tank culture was positively associated with LSCC in the organic model. Standard plate count was also positively associated with LSCC in the organic model. Several variables that were associated with

  19. Evidence for anisotropic dielectric properties of monoclinic hafnia using valence electron energy-loss spectroscopy in high-resolution transmission electron microscopy and ab initio time-dependent density-functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Guedj, C. [University Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Hung, L.; Sottile, F. [LSI, CNRS, CEA, École Polytechnique, F-91128 Palaiseau (France); European Theoretical Spectroscopy Facility (ETSF) (France); Zobelli, A. [LPS, CNRS and University Paris Sud, F-91405 Orsay (France); Blaise, P. [University Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); European Theoretical Spectroscopy Facility (ETSF) (France); Olevano, V. [University Grenoble Alpes, F-38000 Grenoble (France); European Theoretical Spectroscopy Facility (ETSF) (France); CNRS, Institut Néel, F-38042 Grenoble (France)

    2014-12-01

    The effect of nanocrystal orientation on the energy loss spectra of monoclinic hafnia (m-HfO{sub 2}) is measured by high resolution transmission electron microscopy (HRTEM) and valence energy loss spectroscopy (VEELS) on high quality samples. For the same momentum-transfer directions, the dielectric properties are also calculated ab initio by time-dependent density-functional theory (TDDFT). Experiments and simulations evidence anisotropy in the dielectric properties of m-HfO{sub 2}, most notably with the direction-dependent oscillator strength of the main bulk plasmon. The anisotropic nature of m-HfO{sub 2} may contribute to the differences among VEELS spectra reported in literature. The good agreement between the complex dielectric permittivity extracted from VEELS with nanometer spatial resolution, TDDFT modeling, and past literature demonstrates that the present HRTEM-VEELS device-oriented methodology is a possible solution to the difficult nanocharacterization challenges given in the International Technology Roadmap for Semiconductors.

  20. Evidence for anisotropic dielectric properties of monoclinic hafnia using valence electron energy-loss spectroscopy in high-resolution transmission electron microscopy and ab initio time-dependent density-functional theory

    Science.gov (United States)

    Guedj, C.; Hung, L.; Zobelli, A.; Blaise, P.; Sottile, F.; Olevano, V.

    2014-12-01

    The effect of nanocrystal orientation on the energy loss spectra of monoclinic hafnia (m-HfO2) is measured by high resolution transmission electron microscopy (HRTEM) and valence energy loss spectroscopy (VEELS) on high quality samples. For the same momentum-transfer directions, the dielectric properties are also calculated ab initio by time-dependent density-functional theory (TDDFT). Experiments and simulations evidence anisotropy in the dielectric properties of m-HfO2, most notably with the direction-dependent oscillator strength of the main bulk plasmon. The anisotropic nature of m-HfO2 may contribute to the differences among VEELS spectra reported in literature. The good agreement between the complex dielectric permittivity extracted from VEELS with nanometer spatial resolution, TDDFT modeling, and past literature demonstrates that the present HRTEM-VEELS device-oriented methodology is a possible solution to the difficult nanocharacterization challenges given in the International Technology Roadmap for Semiconductors.

  1. Novel Two-Dimensional Conjugated Polymer Containing Fluorinated Bithiophene as Donor and Benzoselenodiazole as Acceptor Units with Vinyl-Terthiophene Pendants for Polymer Photovoltaic Cells

    Directory of Open Access Journals (Sweden)

    Rathinam Raja

    2017-07-01

    Full Text Available Novel two-dimensional conjugated copolymer, abbreviated as PDTBSeVTT-2TF, containing electron-deficient 4,7-di(thiophen-2-ylbenzo[c][1,2,5]selenodiazole (DTBSe unit, conjugated vinyl-terthiophene (VTT side chain and 3,3′-difluoro-2,2′-bithiophene (2TF was designed and synthesized using microwave-assisted Stille cross-coupling polymerization. UV–visible absorption and cyclic voltammetry studies revealed that this copolymer possesses a strong and broad absorption in the range of 300–800 nm and a narrow optical bandgap (Eg of 1.57 eV with low-lying HOMO and LUMO energy levels. Further, the bulk heterojunction polymer solar cells (PSCs were fabricated using PDTBSeVTT-2TF as donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM as acceptor with an inverted device structure of ITO/ZnO/PDTBSeVTT-2TF:PC71BM/V2O5/Ag. The processing temperature of blend solution for preparing PDTBSeVTT-2TF:PC71BM active layer showed obvious impact on the photovoltaic performance of solar devices. The cell fabricated from the blend solution at 65 °C exhibited enhanced power conversion efficiencies (PCE of 5.11% with a Jsc of 10.99 mA/cm−2 compared with the one at 50 °C, which had a PCE of 4.69% with a Jsc of 10.10 mA/cm−2. This enhancement is due to the dissolution of PDTBSeVTT-2TF clusters into single molecules and small aggregates, improving the miscibility between the polymer and PC71BM and thus increasing the donor/acceptor interface.

  2. High-Tc superconductivity in ultrathin Bi2Sr2CaCu2O(8+x) down to half-unit-cell thickness by protection with graphene.

    Science.gov (United States)

    Jiang, Da; Hu, Tao; You, Lixing; Li, Qiao; Li, Ang; Wang, Haomin; Mu, Gang; Chen, Zhiying; Zhang, Haoran; Yu, Guanghui; Zhu, Jie; Sun, Qiujuan; Lin, Chengtian; Xiao, Hong; Xie, Xiaoming; Jiang, Mianheng

    2014-12-08

    High-Tc superconductors confined to two dimension exhibit novel physical phenomena, such as superconductor-insulator transition. In the Bi2Sr2CaCu2O(8+x) (Bi2212) model system, despite extensive studies, the intrinsic superconducting properties at the thinness limit have been difficult to determine. Here, we report a method to fabricate high quality single-crystal Bi2212 films down to half-unit-cell thickness in the form of graphene/Bi2212 van der Waals heterostructure, in which sharp superconducting transitions are observed. The heterostructure also exhibits a nonlinear current-voltage characteristic due to the Dirac nature of the graphene band structure. More interestingly, although the critical temperature remains essentially the same with reduced thickness of Bi2212, the slope of the normal state T-linear resistivity varies by a factor of 4-5, and the sheet resistance increases by three orders of magnitude, indicating a surprising decoupling of the normal state resistance and superconductivity. The developed technique is versatile, applicable to investigate other two-dimensional (2D) superconducting materials.

  3. Pd-Pt loaded graphene aerogel on nickel foam composite as binder-free anode for a direct glucose fuel cell unit

    Science.gov (United States)

    Tsang, Chi Him A.; Leung, D. Y. C.

    2017-09-01

    Fabrication of electrocatalyst for direct glucose fuel cell (DGFC) operation involves destructive preparation methods with the use of stabilizer like binder, which may cause activity depreciation. Binder-free electrocatalytic electrode becomes a possible solution to the above problem. Binder-free bimetallic Pd-Pt loaded graphene aerogel on nickel foam plates with different Pd/Pt ratios (1:2.32, 1:1.62, and 1:0.98) are successfully fabricated through a green one-step mild reduction process producing a Pd-Pt/GO/nickel form plate (NFP) composite. Anode with the binder-free electrocatalysts exhibit a strong activity in a batch type DGFC unit under room temperature. The effects of glucose and KOH concentrations, and the Pd/Pt ratios of the electrocatalyst on the DGFC performance are also studied. Maximum power density output of 1.25 mW cm-2 is recorded with 0.5 M glucose/3 M KOH as the anodic fuel, and Pd1Pt0.98/GA/NFP as catalyst, which is the highest obtained so far among other types of electrocatalyst.

  4. Simultaneous microwave photonic and phononic band gaps in piezoelectric–piezomagnetic superlattices with three types of domains in a unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zheng-hua [Xiangnan University-Gospell Joint Laboratory of Microwave Communication Technology, Xiangnan University, Chenzhou 423000 (China); Jiang, Zheng-Sheng [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Chen, Tao [Laboratory of Quantum Information and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Lei, Da-Jun [Xiangnan University-Gospell Joint Laboratory of Microwave Communication Technology, Xiangnan University, Chenzhou 423000 (China); Yan, Wen-Yan, E-mail: yanwenyan88@126.com [School of Software and Communication Engineering, Xiangnan University, Chenzhou 423000 (China); Qiu, Feng; Huang, Jian-Quan; Deng, Hai-Ming; Yao, Min [Xiangnan University-Gospell Joint Laboratory of Microwave Communication Technology, Xiangnan University, Chenzhou 423000 (China)

    2016-04-29

    A novel phoxonic crystal using the piezoelectric (PMN-PT) and piezomagnetic (CoFe{sub 2}O{sub 4}) superlattices with three types of domains in a unit cell (PPSUC) is present, in which dual microwave photonic and phononic band gaps can be obtained simultaneously. Two categories of phononic band gaps, originating from both the Bragg scattering of acoustic waves in periodic structures at the Brillouin zone boundary and the electromagnetic wave-lattice vibration couplings near the Brillouin zone center, can be observed in the phononic band structures. The general characteristics of the microwave photonic band structures are similar to those of pure piezoelectric or piezomagnetic superlattices, with the major discrepancy being the appearance of nearly dispersionless branches within the microwave photonic band gaps, which show an extremely large group velocity delay. Thus, the properties may also be applied to compact acoustic-microwave devices. - Highlights: • Dual microwave photonic and phononic band gaps can coexist in the PPSUC. • Two categories of phononic band gaps with different mechanism can be obtained. • Nearly dispersionless branches appear in the microwave photonic band gaps.

  5. Post-Marketing Surveillance of Human Rabies Diploid Cell Vaccine (Imovax in the Vaccine Adverse Event Reporting System (VAERS in the United States, 1990‒2015.

    Directory of Open Access Journals (Sweden)

    Pedro L Moro

    2016-07-01

    Full Text Available In 1980, human diploid cell vaccine (HDCV, Imovax Rabies, Sanofi Pasteur, was licensed for use in the United States.To assess adverse events (AEs after HDCV reported to the US Vaccine Adverse Event Reporting System (VAERS, a spontaneous reporting surveillance system.We searched VAERS for US reports after HDCV among persons vaccinated from January 1, 1990-July 31, 2015. Medical records were requested for reports classified as serious (death, hospitalization, prolonged hospitalization, disability, life-threatening-illness, and those suggesting anaphylaxis and Guillain-Barré syndrome (GBS. Physicians reviewed available information and assigned a primary clinical category to each report using MedDRA system organ classes. Empirical Bayesian (EB data mining was used to identify disproportional AE reporting after HDCV.VAERS received 1,611 reports after HDCV; 93 (5.8% were serious. Among all reports, the three most common AEs included pyrexia (18.2%, headache (17.9%, and nausea (16.5%. Among serious reports, four deaths appeared to be unrelated to vaccination.This 25-year review of VAERS did not identify new or unexpected AEs after HDCV. The vast majority of AEs were non-serious. Injection site reactions, hypersensitivity reactions, and non-specific constitutional symptoms were most frequently reported, similar to findings in pre-licensure studies.

  6. Cell-free DNA increase over first 48 hours in emergency intensive care unit predicts fatal outcome in patients with shock.

    Science.gov (United States)

    Xia, Dun Ling; Zhang, Hong; Luo, Qing Li; Zhang, A Fang; Zhu, Li Xin

    2016-10-01

    Objective To investigate whether circulating cell-free (cf)-DNA levels are a useful biomarker for survival in patients with shock in the emergency intensive care unit (EICU). Methods This prospective observational study enrolled patients admitted to the EICU diagnosed with shock. Blood cf-DNA levels were analysed on admission, and after 24 and 48 h. As a measure of circulating cf-DNA, copy number of the β-globin gene in plasma was assessed using quantitative real-time polymerase chain reaction. Results Circulating cf-DNA levels were higher at hospital admission and after 24 h in EICU patients with shock who died than in those who recovered. Change in cf-DNA levels over the first 48 h in critical care was independently associated with 28-day mortality. The critical cut-off value for cf-DNA change over 48 h in predicting 28-day mortality was +16.12% (sensitivity 68.9%, specificity 89.7%). Conclusions Increased circulating cf-DNA levels in EICU patients with shock are associated with risk of death and measuring cf-DNA change over 48 h improves risk prediction. The present study suggests that cf-DNA may serve as a viable plasma biomarker of mortality risk in EICU patients with shock.

  7. Bifurcation structure of the special class of nonstationary regimes emerging in the 2D inertially coupled, unit-cell model: Analytical study

    Science.gov (United States)

    Vorotnikov, K.; Starosvetsky, Y.

    2016-09-01

    Present work is devoted to the analytical investigation of the bifurcation structure of special class of nonstationary low-energy regimes emerging in the locally resonant unit-cell model. System under consideration comprises an outer mass with internal rotator and subject to the 2D, nonlinear local potential. These regimes are characterized by the slow, purely rotational motion of the rotator synchronized with the periodic energy beats between the axial and the lateral vibrations of the outer element. Thus the angular speed of the rotator and the beating frequency of the outer element satisfy the 1:2 resonance condition. In the present study these regimes are referred to as regimes of synchronous nonlinear beats (RSNB). Using the regular muti-scale analysis in the limit of low energy excitation we derive the slow-flow model. To showcase the evolution of RSNBs we used the special Poincaré map technique applied on the slow-flow model. Results of the Poincaré sections unveiled some interesting local bifurcations undergone by these regimes. Further analysis of the slow-flow model enabled us to describe the RSNBs analytically as well as exposed their entire bifurcation structure. The bifurcation analysis has shown the coexistence of several branches of RSNBs corresponding to the regimes of weak and strong, two-dimensional, recurrent energy channeling. We substantiate the results of the analytical study with numerical simulations of the full model and find them to be in the very good agreement.

  8. Admission of hematopoietic cell transplantation patients to the intensive care unit at the Pontificia Universidad Católica de Chile Hospital.

    Science.gov (United States)

    Escobar, Karen; Rojas, Patricio; Ernst, Daniel; Bertin, Pablo; Nervi, Bruno; Jara, Veronica; Garcia, Maria Jose; Ocqueteau, Mauricio; Sarmiento, Mauricio; Ramirez, Pablo

    2015-01-01

    Patients undergoing hematopoietic cell transplantation (HCT) can have complications that require management in the intensive care unit (ICU). We conducted a retrospective study of patients undergoing HCT between 2007 and 2011 with admission to the ICU. We analyzed 97 patients, with an average age of 37 (range, 15 to 68). The main indications for HCT were hematologic malignancies (84%, n = 82). Ninety percent (n = 87) received myeloablative conditioning. Thirty-one percent were admitted (autologous transplant recipients 15%, allogeneic transplant recipients 34%, and umbilical cord blood [UCB] transplant recipients 48%) with an average length of stay of 19 days (range, 1 to 73 days). The average time between transplantation and transfer was 15 days. The main causes of admission were acute respiratory failure (63%) and septic shock (20%). ICU mortality was 20% for autologous transplantations and 64% for allogeneic transplantations (adult donor and UCB combined). On average, patients died 108 days after the transplantation (range, 4 to 320 days). One-year overall survival, comparing patients entering the ICU with those never admitted, was 16% versus 82% (P < .0001) for allogeneic transplantations (adult donor and UCB combined) and 80% versus 89% (P = not significant) for autologous transplantations. Acute graft-versus-host disease was significantly associated with death in ICU after UCB HCT. ICU support is satisfactory in about one half of patients admitted, characterized by a short and medium term prognosis not as unfavorable as has been previously reported.

  9. Post-Marketing Surveillance of Human Rabies Diploid Cell Vaccine (Imovax) in the Vaccine Adverse Event Reporting System (VAERS) in the United States, 1990‒2015

    Science.gov (United States)

    Moro, Pedro L.; Woo, Emily Jane; Paul, Wendy; Lewis, Paige; Petersen, Brett W.; Cano, Maria

    2016-01-01

    Background In 1980, human diploid cell vaccine (HDCV, Imovax Rabies, Sanofi Pasteur), was licensed for use in the United States. Objective To assess adverse events (AEs) after HDCV reported to the US Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting surveillance system. Methods We searched VAERS for US reports after HDCV among persons vaccinated from January 1, 1990–July 31, 2015. Medical records were requested for reports classified as serious (death, hospitalization, prolonged hospitalization, disability, life-threatening-illness), and those suggesting anaphylaxis and Guillain-Barré syndrome (GBS). Physicians reviewed available information and assigned a primary clinical category to each report using MedDRA system organ classes. Empirical Bayesian (EB) data mining was used to identify disproportional AE reporting after HDCV. Results VAERS received 1,611 reports after HDCV; 93 (5.8%) were serious. Among all reports, the three most common AEs included pyrexia (18.2%), headache (17.9%), and nausea (16.5%). Among serious reports, four deaths appeared to be unrelated to vaccination. Conclusions This 25-year review of VAERS did not identify new or unexpected AEs after HDCV. The vast majority of AEs were non-serious. Injection site reactions, hypersensitivity reactions, and non-specific constitutional symptoms were most frequently reported, similar to findings in pre-licensure studies. PMID:27410239

  10. Coherence for weak units

    CERN Document Server

    Joyal, André

    2009-01-01

    We define weak units in a semi-monoidal 2-category $\\CC$ as cancellable pseudo-idempotents: they are pairs $(I,\\alpha)$ where $I$ is an object such that tensoring with $I$ from either side constitutes a biequivalence of $\\CC$, and $\\alpha: I \\tensor I \\to I$ is an equivalence in $\\CC$. We show that this notion of weak unit has coherence built in: Theorem A: $\\alpha$ has a canonical associator 2-cell, which automatically satisfies the pentagon equation. Theorem B: every morphism of weak units is automatically compatible with those associators. Theorem C: the 2-category of weak units is contractible if non-empty. Finally we show (Theorem E) that the notion of weak unit is equivalent to the notion obtained from the definition of tricategory: $\\alpha$ alone induces the whole family of left and right maps (indexed by the objects), as well as the whole family of Kelly 2-cells (one for each pair of objects), satisfying the relevant coherence axioms.

  11. An Applied Study on the Decontamination and Decommissioning of Hot Cell Facilities in the United States and Comparison with the Studsvik Facility for Solid and Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Geoff; Rusch, Chris [NAC International, Atlanta, GA (United States)

    2006-07-15

    Dismantlement occurred during Phase II. The activities included: a. Dismantlement of the building structure surrounding the hot cells and then finally dismantlement of the hot cell block b. Soil remediation c. Handling and disposal of decommissioning wastes d. Confirmatory surveys 3. Final site release occurred during Phase III. 4. The final activity which occurred substantially after Phases II and III were complete was the shipment of the IFM to a DOE facility. The HCF and HM structures are approximately the same size on a volumetric basis. The volume of the HM hot cells is about 12 percent greater than at HCF but the HCF had 27 percent more surface area due to the existence of three separate cells. Of potential importance is that the contamination levels on the hot cell surfaces were not equal. The HCF facility was highly contaminated from such activities as band-sawing irradiated high temperature gas cooled reactor fuel. On these grounds it might be expected that the HCF actual costs would be higher than HM estimates. However, a factor of almost nine times higher seems to be exceptional. The very large difference in fact stems from a number of special circumstances at HCF that need to be backed-out of a cost comparison in order to make it meaningful. One special requirement was the removal and safe management of irradiated fuel material, including high enriched uranium. Another cost related to maintenance of the building before decommissioning could commence. The costs of waste disposal also vary substantially, in terms of unit costs and the proportion of dismantling waste that needs to be sentenced to a radioactive waste repository. The available information for HM has been evaluated and compared, to the extent possible, with the HCF decommissioning costs and other selected NAC derived decommissioning cost benchmarks. In summary the main conclusions for the HM decommissioning cost estimate are as follows: Theoretical estimates of planning and other support activities can

  12. [Conservation Units.

    Science.gov (United States)

    Texas Education Agency, Austin.

    Each of the six instructional units deals with one aspect of conservation: forests, water, rangeland, minerals (petroleum), and soil. The area of the elementary school curriculum with which each correlates is indicated. Lists of general and specific objectives are followed by suggested teaching procedures, including ideas for introducing the…

  13. [Conservation Units.

    Science.gov (United States)

    Texas Education Agency, Austin.

    Instructional units deal with each aspect of conservation: forests, wildlife, rangelands, water, minerals, and soil. The area of the secondary school curriculum with which each is correlated is indicated. Lists of general and specific objectives are followed by suggested teaching procedures, including ideas for introducing the topic, questions to…

  14. Solution Processed Organic Photovoltaic Cells Using D-A-D-A-D Type Small Molecular Donor Materials with Benzodithiophene and Diketopyrrolopyrrole Units.

    Science.gov (United States)

    Park, Sangman; Nam, So Yeon; Suh, Dong Hack; Lee, Jaemin; Lee, Changjin; Yoon, Sung Cheol

    2016-03-01

    Organic photovoltaic Cells (OPVs) have been considered to be a next-generation energy source to overcome exhaustion of resources. Currently, OPVs are developed based on two types of donor material with polymer and small molecule. Polymeric donor materials have shown better power conversion efficiency (PCE) than small molecular donor materials, since it's easy to control the morphology of photoactive film. However, the difficulty in synthetic reproducibility and purification of polymeric donor were main drawback to overcome. And then, recently small molecule donor materials have been overcome bad morphology of OPVs film by using appropriate alkyl substituents and relatively long conjugation system. In this study, we designed and synthesized D-A-D-A-D type small molecular donor materials containing alternatively linked benzodithiophene (BDT) and diketopyrrolopyrrole (DPP) units. Also, we studied on the effect of photovoltaic performance of prepared small molecular D-A-D-A-D type donor with variation of thiophene links and with/without hexyl substituent. Our small molecular donors showed HOMO energy levels from -5.26 to -5.34 eV and optical bandgaps from 1.70 to 1.87 eV by CV (cyclic voltammetry) and UV/Vis spectroscopy, respectively. Finally, 3.4% of PCE can be obtained using a mixture of BDT(DPP)2-T2 and PCBM as an active layer with a Voc of 0.78 V, a Jsc of 9.72 mA/cm2, and a fill factor of 0.44 under 100 mW/cm2 AM 1.5G simulated light. We will discuss the performance of D-A-D-A-D type small molecular donor based OPVs with variation of both terminal substituents.

  15. Chlorhexidine bathing for the prevention of colonization and infection with multidrug-resistant microorganisms in a hematopoietic stem cell transplantation unit over a 9-year period

    Science.gov (United States)

    Mendes, Elisa Teixeira; Ranzani, Otavio T.; Marchi, Ana Paula; da Silva, Mariama Tomaz; Filho, José Ulysses Amigo; Alves, Tânia; Guimarães, Thais; Levin, Anna S.; Costa, Silvia Figueiredo

    2016-01-01

    Abstract Health care associated infections (HAIs) are currently among the major challenges to the care of hematopoietic stem cell transplantation (HSCT) patients. The objective of the present study was to evaluate the impact of 2% chlorhexidine (CHG) bathing on the incidence of colonization and infection with vancomycin-resistant Enterococcus (VRE), multidrug-resistant (MDR) gram-negative pathogens, and to evaluate their CHG minimum inhibitory concentration (MIC) after the intervention. A quasi-experimental study with duration of 9 years was conducted. VRE colonization and infection, HAI rates, and MDR gram-negative infection were evaluated by interrupted time series analysis. The antibacterial susceptibility profile and mechanism of resistance to CHG were analyzed in both periods by the agar dilution method in the presence or absence of the efflux pump inhibitor carbonyl cyanide-m-chlorophenyl hydrazone (CCCP) and presence of efflux pumps (qacA/E, qacA, qacE, cepA, AdeA, AdeB, and AdeC) by polymerase chain reaction (PCR). The VRE colonization and infection rates were significantly reduced in the postintervention period (P = 0.001). However, gram-negative MDR rates in the unit increased in the last years of the study. The CHG MICs for VRE increased during the period of exposure to the antiseptic. A higher MIC at baseline period was observed in MDR gram-negative strains. The emergence of a monoclonal Pseudomonas aeruginosa clone was observed in the second period. Concluding, CHG bathing was efficient regarding VRE colonization and infection, whereas no similar results were found with MDR gram-negative bacteria. PMID:27861350

  16. The North Wind and the Sun: Pediatric Antimicrobial Stewardship Program Combining Restrictive and Persuasive Approaches in Hematology-Oncology Ward and Hematopoietic Stem Cell Transplant Unit.

    Science.gov (United States)

    Horikoshi, Yuho; Kaneko, Tetsuji; Morikawa, Yoshihiko; Isogai, Mihoko; Suwa, Junichi; Higuchi, Hiroshi; Yuza, Yuki; Shoji, Takayo; Ito, Kenta

    2017-08-17

    The Japanese government's goal for the reduction of antimicrobial consumption is two-thirds of the 2013 rate by 2020. While the antimicrobial stewardship programs (ASP) are essential in health care facilities, ASP data on pediatric hematology-oncology and hematopoietic stem cell transplant (HSCT) patients are limited. Our aim was to evaluate the impact of restrictive and persuasive ASP on immunocompromised children. The ASP for hematology-oncology and HSCT patients at Tokyo Metropolitan Children's Medical Center was assessed. Phase 1 was a post-prescriptive review of carbapenem conducted between April, 2010 and September, 2011. Phase 2 consisted of the preauthorization of carbapenem, prospective audit with feedback, a weekly luncheon meeting among physicians, consensus on febrile neutropenia management, and implementation of viral molecular diagnostics between October, 2011 and September, 2015. Both phases were compared for day-of-therapy (DOT) per 1,000 patient-days, cost of intravenous antimicrobial agents, average hospitalization duration, all-cause mortality, infection-related mortality at 30 days, and appropriateness of empirical treatment of bacteremia. The ASP did not differ from phase 1 to phase 2 in terms of average hospitalization length, mortality rate, or appropriateness of empirical treatment for bacteremia. DOTs of cefepime, piperacillin/tazobactam, meropenem, vancomycin, liposomal amphotericin B, and fosfluconazole decreased by 20%, 45%, 57%, 38%, 85% and 44%, respectively (p<0.05). The total cost of antibiotic and antifungal agents decreased by 27%, for a savings of $59,905 USD annually. Restrictive and persuasive ASP in the hematology-oncology ward and the HSCT unit safely decreased the use of antibacterial and antifungal agents.

  17. FLYING UNITED

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Apart from selling hundreds of airplanes to China, Boeing buys locally made aircraft parts and transfers technology, in the true spirit of partnership Whenever Boeing's senior manager hear of a visit by one of China's state leaders, it's no doubt cause for celebration. Since China and the United States established diplomatic ties in 1978, every official trip by China's top statesmen has included a meeting with Boeing that

  18. Unit cell determination of coexisting post-perovskite and H-phase in (Mg,Fe)SiO3 using multigrain XRD: compositional variation across a laser heating spot at 119 GPa

    Science.gov (United States)

    Zhang, Li; Meng, Yue; Mao, Ho-kwang

    2016-12-01

    Multigrain X-ray diffraction (XRD) can be used to accurately calculate the unit cell parameters of individual mineral phases in a mineral assemblage contained in a diamond anvil cell (DAC). Coexisting post-perovskite (ppv) and H-phase were synthesized at 119 GPa and 2500 K from (Mg0.85Fe0.15)SiO3 in a laser-heated DAC. The unit cell parameters of the ppv and coexisting H-phase were determined using multigrain XRD with a 5 μm spatial resolution, close to the size of the X-ray beam, to understand compositional variations across the center area (20-30 μm) in a laser-heated sample. The ppv phase was Fe-depleted and the unit cell volume of ppv decreased by only 0.16 % (corresponding to ~3 % variation of FeSiO3) from the heating center to 10 μm off the center, while the sample pressure remained at 119 GPa in a Ne quasi-hydrostatic environment. The unit cell volume of the H-phase decreased by 0.54 % (~10 % variation of FeSiO3 content) over the same 10 μm distance. Both phases were more Fe-enriched in the slightly hotter center. This observation suggests that thermal diffusion may not be the major driver for the compositional variations of ppv and H-phase in the center portion of a laser-heated sample. Instead, these variations could be caused by a temperature effect on the partitioning between the ppv and H-phase over the small gradient.

  19. United States

    Directory of Open Access Journals (Sweden)

    Stephen Bernow

    1998-12-01

    Full Text Available This paper presents and discusses an integrated set of policies designed to reduce U.S. carbon emissions over the next four decades. This innovation path also aims to promote environmental quality, particularly by reducing emissions of criteria air pollutants, to reduce U.S. dependence on imported oil, and to induce technological innovation and diffusion in energy production and consumption. The innovation path would reduce economy-wide carbon emissions by 26% below baseline projections for 2010 and by 62% below baseline projections for 2030; this translates into 10% below 1990 levels in 2010 and 45% below 1990 levels in 2030. Emissions of criteria pollutants also would be significantly reduced, as would petroleum imports by the United States. Moreover, the innovation path would yield cumulative net savings for the United States of $218 billion (1993 dollars through 2010, or $19 billion on a leveled annual basis, and would result in 800,000 additional jobs nationwide by 2010. Although the overall findings from the innovation path analysis are robust, the results should be taken as indicative, rather than precisely predictive, owing to uncertainties in future costs, prices, technology performance, and consumer behavior.

  20. Pyroelectric properties of the monoclinic rare earth nitrates A{sub 2}Ln(NO{sub 3}){sub 5}.4H{sub 2}O (A = NH{sub 4}, Rb; Ln = La, Ce)

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, Matthias; Andersen, Lionel; Becker, Petra; Bohaty Ladislav [Koeln Univ. (Germany). Inst. fuer Kristallographie

    2015-07-01

    The pyroelectric effect of four isomorphic monoclinic (space group Cc), non-ferroelectric rare earth nitrates A{sub 2}Ln(NO{sub 3}){sub 5}.4H{sub 2}O (A = NH{sub 4}, Rb; Ln = La, Ce) was investigated in the temperature range between 100 K and 300 K, using a home-made continuous-flow cryostat for measurements of pyroelectric currents. The symmetry-allowed temperature-dependent change of orientation of the pyroelectric vector p within the mirror plane is unusually large, showing a rotation of p of 148 , 129 , 36 and 40 for (NH{sub 4}){sub 2}La(NO{sub 3}){sub 5}.4H{sub 2}O, (NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 5}.4H{sub 2}O, Rb{sub 2}La(NO{sub 3}){sub 5}.4H{sub 2}O and Rb{sub 2}Ce(NO{sub 3}){sub 5}.4H{sub 2}O, respectively, while changing the temperature from 100 K to 300 K in each case. The pyroelectric coefficients are up to ten times larger than p{sub 3} of tourmaline. In addition, new data of the pyroelectric coefficients of Li{sub 2}SO{sub 4}.H{sub 2}O and BiB{sub 3}O{sub 6} and their temperature dependence are given.

  1. CFA-2 and CFA-3 (Coordination Framework Augsburg University-2 and -3); novel MOFs assembled from trinuclear Cu(I)/Ag(I) secondary building units and 3,3',5,5'-tetraphenyl-bipyrazolate ligands.

    Science.gov (United States)

    Grzywa, Maciej; Geßner, Christof; Denysenko, Dmytro; Bredenkötter, Björn; Gschwind, Fabienne; Fromm, Katharina M; Nitek, Wojciech; Klemm, Elias; Volkmer, Dirk

    2013-05-21

    The syntheses of H2-phbpz, [Cu2(phbpz)]·2DEF·MeOH (CFA-2) and [Ag2(phbpz)] (CFA-3) (H2-phbpz = 3,3',5,5'-tetraphenyl-1H,1'H-4,4'-bipyrazole) compounds and their crystal structures are described. The Cu(I) containing metal-organic framework CFA-2 crystallizes in the tetragonal crystal system, within space group I4(1)/a (no. 88) and the following unit cell parameters: a = 30.835(14), c = 29.306(7) Å, V = 27 865(19) Å(3). CFA-2 features a flexible 3-D three-connected two-fold interpenetrated porous structure constructed of triangular Cu(I) subunits. Upon exposure to different kinds of liquids (MeOH, EtOH, DMF, DEF) CFA-2 shows pronounced breathing effects. CFA-3 crystallizes in the monoclinic crystal system, within space group P2(1)/c (no. 14) and the following unit cell parameters: a = 16.3399(3), b = 32.7506(4), c = 16.2624(3) Å, β = 107.382(2)°, V = 8305.3(2) Å(3). In contrast to the former compound, CFA-3 features a layered 2-D three-connected structure constructed from triangular Ag(i) subunits. Both compounds are characterized by elemental and thermogravimetric analyses, single crystal structure analysis and X-ray powder diffraction, FTIR- and fluorescence spectroscopy. Preliminary results on oxygen activation in CFA-2 are presented and potential improvements in terms of framework robustness and catalytic efficiency are discussed.

  2. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 116: Area 25 Test Cell C Facility, Nevada Test Site, Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2008-12-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for the closure of Corrective Action Unit (CAU) 116, Area 25 Test Cell C Facility. The Test Cell C (TCC) Facility is located in Area 25 of the Nevada Test Site (NTS) approximately 25 miles northwest of Mercury, Nevada (Figure 1). CAU 116 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) of 1996 (as amended February 2008) and consists of two Corrective Action Sites (CASs): (1) CAS 25-23-20, Nuclear Furnace Piping; and (2) CAS 25-41-05, Test Cell C Facility. CAS 25-41-05 is described in the FFACO as the TCC Facility but actually includes Building 3210 and attached concrete shield wall only. CAU 116 will be closed by demolishing Building 3210, the attached concrete shield wall, and the nuclear furnace piping. In addition, as a best management practice (BMP), Building 3211 (moveable shed) will be demolished due to its close proximity to Building 3210. This will aid in demolition and disposal operations. Radiological surveys will be performed on the demolition debris to determine the proper disposal pathway. As much of the demolition debris as space allows will be placed into the Building 3210 basement structure. After filling to capacity with demolition debris, the basement structure will be mounded or capped and closed with administrative controls. Prior to beginning demolition activities and according to an approved Sampling and Analysis Plan (SAP), representative sampling of surface areas that are known, suspected, or have the potential to contain hazardous constituents such as lead or polychlorinated biphenyls (PCBs) will be performed throughout all buildings and structures. Sections 2.3.2, 4.2.2.2, 4.2.2.3, 4.3, and 6.2.6.1 address the methodologies employed that assure the solid debris placed in the basement structure will not contain contaminants of concern (COCs) above hazardous waste levels. The anticipated post

  3. Termination unit

    Energy Technology Data Exchange (ETDEWEB)

    Traeholt, Chresten; Willen, Dag; Roden, Mark; Tolbert, Jerry C.; Lindsay, David; Fisher, Paul W.; Nielsen, Carsten Thidemann

    2016-05-03

    Cable end section comprises end-parts of N electrical phases/neutral, and a thermally-insulation envelope comprising cooling fluid. The end-parts each comprises a conductor and are arranged with phase 1 innermost, N outermost surrounded by the neutral, electrical insulation being between phases and N and neutral. The end-parts comprise contacting surfaces located sequentially along the longitudinal extension of the end-section. A termination unit has an insulating envelope connected to a cryostat, special parts at both ends comprising an adapter piece at the cable interface and a closing end-piece terminating the envelope in the end-section. The special parts houses an inlet and/or outlet for cooling fluid. The space between an inner wall of the envelope and a central opening of the cable is filled with cooling fluid. The special part at the end connecting to the cryostat houses an inlet or outlet, splitting cooling flow into cable annular flow and termination annular flow.

  4. Prediction of a novel monoclinic carbon allotrope

    Science.gov (United States)

    Amsler, Maximilian; Flores-Livas, José A.; Marques, Miguel A. L.; Botti, Silvana; Goedecker, Stefan

    2013-09-01

    A novel allotrope of carbon with P2/ m symmetry was identified during an ab initio minima-hopping structural search which we call M10-carbon. This structure is predicted to be more stable than graphite at pressures above 14.4 GPa and consists purely of s p 3 bonds. It has a high bulk modulus and is almost as hard as diamond. A comparison of the simulated X-ray diffraction pattern shows a good agreement with experimental results from cold compressed graphite.

  5. Combination of stem cell factor and granulocyte colony-stimulating factor mobilizes the highest number of primitive haemopoietic progenitors as shown by pre-colony-forming unit (pre-CFU) assay.

    Science.gov (United States)

    Horsfall, M J; Hui, C H; To, L B; Begley, C G; Basser, R L; Simmons, P J

    2000-06-01

    Fifty-two patients with poor prognosis carcinoma of the breast underwent peripheral blood stem cell (PBSC) mobilization using five different regimens. The yields of primitive haemopoietic progenitors were quantified by a recently described pre-colony-forming unit (pre-CFU) assay using limiting dilution analysis (LDA). Results of days 14 and 35 pre-CFU were also correlated with conventional CD34+ cell enumeration, CFU-GM (granulocyte-macrophage) and long-term culture-initiating cell (LTCIC) assays. The yield of pre-CFUs with the combination of granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) was significantly higher than with G-CSF alone, cyclophosphamide (Cyclo) and granulocyte-monocyte colony-stimulating factor (GM-CSF), interleukin (IL)-3 and GM-CSF, or Cyclo alone. No significant correlation between neutrophil engraftment and pre-CFU could be demonstrated. Furthermore, CFU-GM was shown to bear a stronger correlation with pre-CFU and LTCIC than CD34+ cell measurement; thus, CFU-GM remains a useful biological tool for haemopoietic stem cell assay. We conclude that the combination of G-CSF and SCF mobilizes the highest number of pre-CFUs as measured by functional pre-CFU assay, which provides an alternative measurement of primitive haemopoietic progenitors to the LTCIC assay.

  6. Developing high-performance small molecule organic solar cells via a large planar structure and an electron-withdrawing central unit.

    Science.gov (United States)

    Zhang, Hongtao; Liu, Yongtao; Sun, Yanna; Li, Miaomiao; Kan, Bin; Ke, Xin; Zhang, Qian; Wan, Xiangjian; Chen, Yongsheng

    2016-12-22

    We designed and synthesized a new small molecule donor material named DR3TBDD using an electron-withdrawing unit BDD as the central building block. A PCE of 9.53% with a high Voc of around 1 V was achieved.

  7. Small Unit Operations

    Science.gov (United States)

    2007-11-02

    best demonstrated value for small (< AA size) lithium - thionyl - chloride batteries (Halpert 1993). Equation (2-3) shows that the solar power...However, this energy den- sity this is only ~ 3 times larger than the demonstrated performance of the best lithium batteries , and the fuel cells are...Units 13 2.2.2 ASIC Capability 15 2.2.3 Power and Size 17 2.2.4 Cost 19 2.3 Power Sources 20 2.3.1 Batteries 21 2.3.2 Solar Augmentation

  8. Lgr5(+ve) stem cells drive self-renewal in the stomach and build long-lived gastric units in vitro

    NARCIS (Netherlands)

    Barker, N.; Huch, M.; Kujala, P.; van de Wetering, M.L.; Snippert, H.J.G.; van Es, J.H.; Sato, T.; Stange, D.E.; Begthel, H.L.; van den Born, M.M.W.; Danenberg, E.M.; van den Brink, S.; Korving, J.; Abo, A.; Peters, P.; Wright, N.; Poulsom, R.; Clevers, H.

    2010-01-01

    The study of gastric epithelial homeostasis and cancer has been hampered by the lack of stem cell markers and in vitro culture methods. The Wnt target gene Lgr5 marks stem cells in the small intestine, colon, and hair follicle. Here, we investigated Lgr5 expression in the stomach and assessed the st

  9. β-Arrestin1/miR-326 Transcription Unit Is Epigenetically Regulated in Neural Stem Cells Where It Controls Stemness and Growth Arrest

    Science.gov (United States)

    Begalli, Federica; Abballe, Luana; Catanzaro, Giuseppina; Vacca, Alessandra; Napolitano, Maddalena; Tafani, Marco; Giangaspero, Felice; Locatelli, Franco

    2017-01-01

    Cell development is regulated by a complex network of mRNA-encoded proteins and microRNAs, all funnelling onto the modulation of self-renewal or differentiation genes. How intragenic microRNAs and their host genes are transcriptionally coregulated and their functional relationships for the control of neural stem cells (NSCs) are poorly understood. We propose here the intragenic miR-326 and its host gene β-arrestin1 as novel players whose epigenetic silencing maintains stemness in normal cerebellar stem cells. Such a regulation is mediated by CpG islands methylation of the common promoter. Epigenetic derepression of β-arrestin1/miR-326 by differentiation signals or demethylating agents leads to suppression of stemness features and cell growth and promotes cell differentiation. β-Arrestin1 inhibits cell proliferation by enhancing the nuclear expression of the cyclin-dependent kinase inhibitor p27. Therefore, we propose a new mechanism for the control of cerebellar NSCs where a coordinated epigenetic mechanism finely regulates β-arrestin1/miR-326 expression and consequently NSCs stemness and cell growth. PMID:28298929

  10. Evaluation of cytomegalovirus (CMV)-specific T-cell immunity for the assessment of the risk of active CMV infection in non-immunosuppressed surgical and trauma intensive care unit patients.

    Science.gov (United States)

    Clari, María A; Aguilar, Gerardo; Benet, Isabel; Belda, Javier; Giménez, Estela; Bravo, Dayana; Carbonell, José A; Henao, Liliana; Navarro, David

    2013-10-01

    The current study was designed to assess the predictive value of the evaluation of cytomegalovirus (CMV)-specific T-cell immunity early following admission to the intensive care unit for inferring the risk of active CMV infection in non-immunosuppressed surgical and trauma patients. A total of 31 CMV-seropositive patients were included. Patients were screened for the presence of CMV DNA in plasma and in tracheal aspirates by real-time PCR. Enumeration of CMV pp65 and IE-1-specific IFN-γ CD8(+) and CD4(+) T cells was performed by flow cytometry for intracellular cytokine staining. Virological and immunological monitoring was conducted once or twice a week. Active CMV infection occurred in 17 out of 31 patients. Undetectable levels of pp65 and IE-1-specific IFN-γ CD8(+) and CD4(+) T-cell subsets cells were observed in 10 patients who developed active CMV infection and in one who did not (at a median of 2 days following ICU admission). Peak CMV DNA loads in both tracheal aspirates and plasma were substantially higher (P = 0.018 and P = 0.091, respectively) in patients with undetectable IFN-γ T-cell responses than in patients with detectable responses. The expansion of both CMV-specific T-cell subsets following detection of active CMV infection was demonstrated in 9 out of 14 patients with active CMV infection. In conclusion, the evaluation of CMV pp65 and IE-1-specific IFN-γ-producing CD8(+) and CD4(+) T cells early following ICU admission may allow the identification of patients most at risk of either having or developing an episode of active CMV infection, particularly those associated with high-level virus replication.

  11. Dancoff factors of unit cells in cluster geometry with partial absorption of neutrons; Fatores de Dancoff de celulas unitarias em geometria cluster com absorcao parcial de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Leticia Jenisch

    2011-01-15

    In its classical formulation, the Dancoff factor for a perfectly absorbing fuel rod is defined as the relative reduction in the incurrent of resonance neutrons into the rod in the presence of neighboring rods, as compared to the incurrent into a single fuel rod immersed in an infinite moderator. Alternatively, this factor can be viewed as the probability that a neutron emerging from the surface of a fuel rod will enter another fuel rod without any collision in the moderator or cladding. For perfectly absorbing fuel these definitions are equivalent. In the last years, several works appeared in literature reporting improvements in the calculation of Dancoff factors, using both the classical and the collision probability definitions. In this work, we step further reporting Dancoff factors for perfectly absorbing (Black) and partially absorbing (Grey) fuel rods calculated by the collision probability method, in cluster cells with square outer boundaries. In order to validate the results, comparisons are made with the equivalent cylindricalized cell in hypothetical test cases. The calculation is performed considering specularly reflecting boundary conditions, for the square lattice, and diffusive reflecting boundary conditions, for the cylindrical geometry. The results show the expected asymptotic behavior of the solution with increasing cell sizes. In addition, Dancoff factors are computed for the Canadian cells CANDU-37 and CANFLEX by the Monte Carlo and Direct methods. Finally, the effective multiplication factors, k{sub eff}, for these cells (cluster cell with square outer boundaries and the equivalent cylindricalized cell) are also computed, and the differences reported for the cases using the perfect and partial absorption assumptions. (author)

  12. Donor and Acceptor Unit Sequences Influence Material Performance in Benzo[1,2-b:4,5-b′]dithiophene-6,7-Difluoroquinoxaline Small Molecule Donors for BHJ Solar Cells

    KAUST Repository

    Wang, Kai

    2016-08-22

    Well-defined small molecule (SM) donors can be used as alternatives to π-conjugated polymers in bulk-heterojunction (BHJ) solar cells with fullerene acceptors (e.g., PC61/71BM). Taking advantage of their synthetic tunability, combinations of various donor and acceptor motifs can lead to a wide range of optical, electronic, and self-assembling properties that, in turn, may impact material performance in BHJ solar cells. In this report, it is shown that changing the sequence of donor and acceptor units along the π-extended backbone of benzo[1,2-b:4,5-b\\']dithiophene-6,7-difluoroquinoxaline SM donors critically impacts (i) molecular packing, (ii) propensity to order and preferential aggregate orientations in thin-films, and (iii) charge transport in BHJ solar cells. In these systems (SM1-3), it is found that 6,7-difluoroquinoxaline ([2F]Q) motifs directly appended to the central benzo[1,2-b:4,5-b\\']dithiophene (BDT) unit yield a lower-bandgap analogue (SM1) with favorable molecular packing and aggregation patterns in thin films, and optimized BHJ solar cell efficiencies of ≈6.6%. 1H-1H DQ-SQ NMR analyses indicate that SM1 and its counterpart with [2F]Q motifs substituted as end-group SM3 possess distinct self-assembly patterns, correlating with the significant charge transport and BHJ device efficiency differences observed for the two analogous SM donors (avg. 6.3% vs 2.0%, respectively). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Division Unit for Binary Integer Decimals

    DEFF Research Database (Denmark)

    Lang, Tomas; Nannarelli, Alberto

    2009-01-01

    -recurrence algorithm to BID representation and implement the division unit in standard cell technology. The implementation of the proposed BID division unit is compared to that of a BCD based unit implementing the same algorithm. The comparison shows that for normalized operands the BID unit has the same latency......In this work, we present a radix-10 division unit that is based on the digit-recurrence algorithm and implements binary encodings (binary integer decimal or BID) for significands. Recent decimal division designs are all based on the binary coded decimal (BCD) encoding. We adapt the radix-10 digit...

  14. Acute crises and complications of sickle cell anemia among patients attending a pediatric tertiary unit in Kinshasa, Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    Michel Ntetani Aloni

    2017-06-01

    Full Text Available In the Democratic Republic of Congo, the incidence of sickle cell anemia (SCA is estimated to affect 30,000 to 40,000 neonates per year. However, there is paucity of data on acute clinical manifestations in sickle cell children. In these circumstances, it is difficult to develop a health care policy for an adequate management of sickle cell patients. This was a seven years’ retrospective study of children admitted with acute sickle cell crisis in the Department of Pediatrics in University Hospital of Kinshasa, Kinshasa, the Democratic Republic of Congo. A total of 108 patients were identified as having SCA. There were 56 (51% girls and 52 (49% boys. Median age was 10.5 years (range 1-24 years. No child was diagnosed by neonatal screening. The median age of diagnosis of sickle cell anemia was 90 months (range: 8-250 months. The median age at the first transfusion was 36 months (range 4-168. In this series, 61 (56.5% patients were eligible for hydroxyurea. However, this treatment was only performed in 4 (6.6% of them. Pain episodes, acute anemic crisis and severe infection represent respectively 38.2%, 34.3% and 21.9% of events. Altered sensorium and focal deficit were encountered occasionally and represented 3.4% of acute events. Acute renal manifestations, cholelithiasis and priapism were rarely reported, in this cohort. In Kinshasa, the care of patients suffering from sickle cell anemia is characterized by the delayed diagnosis and low detection of organ complications compared to reports of Western countries. This situation is due to resources deficiencies.

  15. Nursing management in the laminar air flow units for hematopoietic stem cell transplantation%层流病房造血干细胞移植的护理组织管理

    Institute of Scientific and Technical Information of China (English)

    宋丹; 牛艳萍; 耿丽萍; 马淑卿; 陈静

    2009-01-01

    目的 探讨层流病房造血干细胞移植护理的组织管理方法.方法 对层流病房护士进行专科知识技能、心理干预能力及相关制度培训,建立质量控制标准,完善移植前各项准备工作,建立护理查房制度.结果 提高了护士的专科理论知识及操作技能,33例患者均移植成功,无护理并发症发生.结论 科学有效的组织管理是造血干细胞移植工作顺利开展的重要保证.%Objective To explore nursing management methods in the laminar air flow units for hematopoietic stem cell transplantation. Methods The manage-ment measures included nurse training in the aspects of specialty knowledge and skills, techniques in psychological nursing, related regulations and rules ; formula-tion of quality control standards, careful preparations before transplantation as well as nursing ward round system. Results This practice improved nurses' spe-cialty knowledge and skills, and 33 patients received the transplantation surgery successfully without complications. Conclusion Scientific management can guar-antee the success of hematopoietic stem cell transplantation in the laminar air flow units.

  16. Commercialization scenarios of polymer electrolyte membrane fuel cell applications for stationary power generation in the United States by the year 2015

    Energy Technology Data Exchange (ETDEWEB)

    Millett, Stephen; Mahadevan, Kathya [Battelle Memorial Institute, 505 King Avenue, Columbus, OH 43201 (United States)

    2005-10-04

    Battelle is identifying the most likely markets and economic impacts of stationary polymer electrolyte membrane (PEM) fuel cells in the range of 1-250kW in the U.S. by the year 2015. For this task, Battelle is using the Interactive Future Simulations (IFS(TM)), an analytical modeling and forecasting tool that uses expert judgment, trend analysis, and cross-impact analysis methods to generate most likely future conditions for PEM fuel cell applications, market acceptance, commercial viability, and economic impacts. The cross-impact model contains 28 descriptors including commercial and technological advances in both polymer electrolyte membrane (PEM) fuel cells and fossil fuel technologies, sources of hydrogen, investments, public policy, environmental regulation, value to consumers, commercialization leadership, modes of generation, and the reliability and prices of grid electricity. One likely scenario to the year 2015 is that the PEM fuel cells will be limited to commercial and industrial customers in the range of 50-200kW with a market size less than US$ 5 billion a year. (author)

  17. Rational design of tetraphenylethylene-based luminescent down-shifting molecules: photophysical studies and photovoltaic applications in a CdTe solar cell from small to large units.

    Science.gov (United States)

    Li, Yilin; Li, Zhipeng; Ablekim, Tursunjan; Ren, Tianhui; Dong, Wen-Ji

    2014-12-21

    A rational design strategy of novel fluorophores for luminescent down-shifting (LDS) application was proposed and tested in this paper. Three new fluorophores (1a-c) with specific intramolecular charge transfer (ICT) and aggregation-induced emission (AIE) characteristics were synthesized as LDS molecules for increasing the output short circuit current density (Jsc) of a CdTe solar cell. Photophysical studies of their solution and solid states, and photovoltaic measurements of their PMMA solid films applied on a CdTe solar cell suggested that the specific spectroscopic properties and Jsc enhancement effects of these molecules were highly related to their chemical structures. The Jsc enhancement effects of these fluorophores were measured on both a CdTe small cell and a large panel. An increase in the output Jsc by as high as 5.69% for a small cell and 8.88% for a large panel was observed. Compared to a traditional LDS molecule, Y083, these fluorophores exhibited more superior capabilities of LDS.

  18. 基于QCA可编程逻辑阵列单元的元胞缺陷研究%Study of Cell Defects of the Programmable Logic Array Unit Based on the Quantum-Dot Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    李政操; 蔡理; 黄宏图

    2012-01-01

    介绍了一种量子元胞自动机(QCA)可编程逻辑阵列结构,该结构可用于实现量子元胞自动机大规模可编程逻辑电路,采用QCADesigner仿真软件研究了元胞缺失、移位缺陷和未对准缺陷对可编程逻辑阵列单元逻辑功能的影响.得出了特定结构下,每个元胞移位缺陷和未对准缺陷的最大错位距离,以及导线模式中存在特定位置的8个可缺失元胞.这为缺陷单元的应用提供了一个具体的参数标准,提高了PLA阵列的单元利用率.%A programmable logic array (PLA) structure that can be used in the large scale integrated circuit using quantum-dot cellular automata (QCA) was introduced. The effects of the cell omission , cell misalignment and cell displacement on the PLA were researched by QCADesigner. And the maximum fault-tolerant ranges of displacement and misalignment for each cell were obtained for a certain structure. Besides that, the 8-cell omission defect in the wire mode was also achieved. The research provides a concrete parameter criterion for applying defect units normally, and advances the utilizing rate of the cell.

  19. Development and design of experiments optimization of a high temperature proton exchange membrane fuel cell auxiliary power unit with onboard fuel processor

    Science.gov (United States)

    Karstedt, Jörg; Ogrzewalla, Jürgen; Severin, Christopher; Pischinger, Stefan

    In this work, the concept development, system layout, component simulation and the overall DOE system optimization of a HT-PEM fuel cell APU with a net electric power output of 4.5 kW and an onboard methane fuel processor are presented. A highly integrated system layout has been developed that enables fast startup within 7.5 min, a closed system water balance and high fuel processor efficiencies of up to 85% due to the recuperation of the anode offgas burner heat. The integration of the system battery into the load management enhances the transient electric performance and the maximum electric power output of the APU system. Simulation models of the carbon monoxide influence on HT-PEM cell voltage, the concentration and temperature profiles within the autothermal reformer (ATR) and the CO conversion rates within the watergas shift stages (WGSs) have been developed. They enable the optimization of the CO concentration in the anode gas of the fuel cell in order to achieve maximum system efficiencies and an optimized dimensioning of the ATR and WGS reactors. Furthermore a DOE optimization of the global system parameters cathode stoichiometry, anode stoichiometry, air/fuel ratio and steam/carbon ratio of the fuel processing system has been performed in order to achieve maximum system efficiencies for all system operating points under given boundary conditions.

  20. Life Functions and Cells: Level II, Unit 7, Lesson 1; Cell Structure: Lesson 2; Tissues, Organs, Systems: Lesson 3; Growth and Nutrition: Lesson 4; Metabolism: Lesson 5. Advanced General Education Program. A High School Self-Study Program.

    Science.gov (United States)

    Manpower Administration (DOL), Washington, DC. Job Corps.

    This self-study program for high-school level contains lessons on: Life Functions and Cells; Cell Structure; Tissues, Organs, Systems; Growth and Nutrition; and Metabolism. Each of the lessons concludes with a Mastery Test to be completed by the student. (DB)

  1. Cells

    Directory of Open Access Journals (Sweden)

    Zhao-Hui Jin

    2012-11-01

    Full Text Available As cancer stem cells (CSCs are postulated to play critical roles in cancer development, including metastasis and recurrence, CSC imaging would provide valuable information for cancer treatment and lead to CSC-targeted therapy. To assess the possibility of in vivo CSC targeting, we conducted basic studies on radioimmunotargeting of cancer cells positive for CD133, a CSC marker recognized in various cancers. Antibodies against CD133 were labeled with 125I, and their in vitro cell binding properties were tested. Using the same isotype IgG as a control, in vivo biodistribution of the labeled antibody retaining immunoreactivity was examined in mice bearing an HCT116 xenograft in which a population of the cancer cells expressed CD133. Intratumoral distribution of the labeled antibody was examined and compared to the CD133 expression pattern. The 125I-labeled anti-CD133 antibody showed a modest but significantly higher accumulation in the HCT116 xenograft compared to the control IgG. The intratumoral distribution of the labeled antibody mostly overlapped with the CD133 expression, whereas the control IgG was found in the area close to the necrotic tumor center. Our results indicate that noninvasive in vivo targeting of CSCs could be possible with radiolabeled antibodies against cell membrane markers.

  2. Efficiency gain of solid oxide fuel cell systems by using anode offgas recycle - Results for a small scale propane driven unit

    Science.gov (United States)

    Dietrich, Ralph-Uwe; Oelze, Jana; Lindermeir, Andreas; Spitta, Christian; Steffen, Michael; Küster, Torben; Chen, Shaofei; Schlitzberger, Christian; Leithner, Reinhard

    The transfer of high electrical efficiencies of solid oxide fuel cells (SOFC) into praxis requires appropriate system concepts. One option is the anode-offgas recycling (AOGR) approach, which is based on the integration of waste heat using the principle of a chemical heat pump. The AOGR concept allows a combined steam- and dry-reforming of hydrocarbon fuel using the fuel cell products steam and carbon dioxide. SOFC fuel gas of higher quantity and quality results. In combination with internal reuse of waste heat the system efficiency increases compared to the usual path of partial oxidation (POX). The demonstration of the AOGR concept with a 300 Wel-SOFC stack running on propane required: a combined reformer/burner-reactor operating in POX (start-up) and AOGR modus; a hotgas-injector for anode-offgas recycling to the reformer; a dynamic process model; a multi-variable process controller; full system operation for experimental proof of the efficiency gain. Experimental results proof an efficiency gain of 18 percentage points (η·POX = 23%, η·AOGR = 41%) under idealized lab conditions. Nevertheless, further improvements of injector performance, stack fuel utilization and additional reduction of reformer reformer O/C ratio and system pressure drop are required to bring this approach into self-sustaining operation.

  3. Process analysis of electricity generation for vehicle powertrains with methanol as energy carrier and fuel-cells as energy conversion units; Verfahrensanalyse der Stromerzeugung fuer Fahrzeugantriebe mit Methanol als Energietraeger und Brennstoffzellen als Energieumwandlungssystem

    Energy Technology Data Exchange (ETDEWEB)

    Menzer, R.; Hoehlein, B.

    1997-10-01

    Hydrogen-powered low-temperature fuel cells (PEFC) are the energy conversion units in vehicles with methanol as energy carrier and a powertrain consisting of the following main units: Methanol reformer (H{sub 2}-production) including catalytic converter, gas treatment, PEFC with peripheral units, electric motor with electric controllers and gearbox. The process engineering analysis is based on a simulation model (PRO/II, SIMSCI) and describes the energy and water management as a function of different assumptions as well as operating and ambient conditions for net electricity generation in a PEFC-powered powertrain. In particular, it presents an approach for balancing both water recovery (PEFC) and the use of water for the methanol reforming process as well as for the humidification of the PEFC. The overall balances present an optimized energy management including the peripheral air compression for the PEFC and the special emission options as compared with conventional powertrains (internal combustion engines). (orig.) [Deutsch] Wasserstoffbetriebene Niedertemperatur-Brennstoffzellen (PEFC) sind Energieumwandlungseinheiten in einem Fahrzeugantrieb mit Methanol als Energietraeger bestehend aus: Methanol-Reformer mit Katalyt-Konverter zur H{sub 2}-Erzeugung, Gasnachbehandlung, PEFC mit peripheren Einheiten, Elektromotor und Getriebe. Die vorgestellte Prozessanalyse basiert auf einem Simulationsmodell (PRO/II, SIMSCI) und beschreibt das Energie- und Wassermanagement als Funktion verschiedener Annahmen, Betriebszustaende und Umgebungsbedingungen fuer die Netto-Stromerzeugung in einem Antrieb mit PEFC. Insbesondere wird die Situation der Wassererzeugung (PEFC) einerseits und der Wassernutzung fuer den Reformer und die PEFC-Befeuchtung andererseits dargestellt. Die Gesamtbilanz zeigt das Energiemanagement einschliesslich der Luftkompression fuer die Kathodenluft der PEFC wie auch die besonderen Emissionsvorteile im Vergleich zu konventionellen Antrieben mit

  4. Laser Molecular Beam Epitaxy of Multilayer Heterostructure SrNb0.05 Ti0.95O3/La0.9Sr0.1MnO3 in 10000 Unit-Cell Layers

    Institute of Scientific and Technical Information of China (English)

    HUANG Yan-Hong; HE Meng; TIAN Huan-Fang; ZHAO Kun; L(U) Hui-Bin; JIN Kui-Juan; LI Jian-Qi; YANG Guo-Zhen

    2008-01-01

    Ten thousands of unit-cell multilayer heterosturctures, [SrNb0.05 Ti0.95 O3/La0.9Sr0.1MnO3]3 (SNTO/LSMO),have been epitaxial grown on SrTiO3 (001) substrates by laser molecular beam epitaxy. The monitor of insitu reflection high-energy electron diffraction demonstrates that the heterosturctures are layer-by-layer epitaxial growth. Atomic force microscope observation indicates that the surface of the heterosturcture is atomically smooth. The measurements of cross-sectional low magnification and high-resolution transmission electron microscopy as well as the corresponding selected area electron diffraction reveal that the interfaces are of perfect orientation, and the epitaxial crystalline structure shows the orientation relation of SNTO(001)//LSMO(001),and SNTO[100]//LSMO[100].

  5. Using SI Units in Astronomy

    Science.gov (United States)

    Dodd, Richard

    2011-12-01

    1. Introduction; 2. An introduction to SI units; 3. Dimensional analysis; 4. Unit of angular measure (radian); 5. Unit of time (second); 6. Unit of length (metre); 7. Unit of mass (kilogram); 8. Unit of luminous intensity (candela); 9. Unit of thermodynamic temperature (kelvin); 10. Unit of electric current (ampere); 11. Unit of amount of substance (mole); 12. Astronomical taxonomy; Index.

  6. Reflections on the United States National Institutes of Health draft guidelines for research involving human pluripotent stem cells--theological perspective.

    Science.gov (United States)

    Sotis, J J

    2000-01-01

    Since the human embryonic stem cell research involves destruction of human embryos and, therefore, hinges on the fundamental question of the status of the embryo, it is essential to examine this status carefully in order to establish fitting guidelines for research. The US National Institutes of Health has proposed its own guidelines on the matter recently (1999). The document, rooted in current pluralistic perspectives in moral philosophy (or bioethics), is criticised in this paper as morally inadequate. The argumentation of the criticism stems from the theological perspective on human personhood, which focuses on a continuity of personal identity from embryos to adult human beings. An additional concern for the author is the moral complicity in which the research dependent upon the destruction of human embryonic life is sanctioned.

  7. Low cost balancing unit design

    Science.gov (United States)

    Golembiovsky, Matej; Dedek, Jan; Slanina, Zdenek

    2017-06-01

    This article deals with the design of a low-cost balancing system which consist of battery balancing units, accumulator pack units and coordinator unit with interface for higher level of battery management system. This solution allows decentralized mode of operation and the aim of this work is implementation of controlling and diagnostic mechanism into an electric scooter project realized at Technical university of Ostrava. In todays world which now fully enjoys the prime of electromobility, off-grid battery systems and other, it is important to seek the optimal balance between functionality and the economy side of BMS that being electronics which deals with secondary cells of batery packs. There were numerous sophisticated, but not too practical BMS models in the past, such as centralized system or standalone balance modules of individual cells. This article aims at development of standalone balance modules which are able to communicate with the coordinator, adjust their parameters and ensure their cells safety in case of a communication failure. With the current worldwide cutting cost trend in mind, the emphasis was put on the lowest price possible for individual component. The article is divided into two major categories, the first one being desing of power electronics with emphasis on quality, safety (cooling) and also cost. The second part describes development of a communication interface with reliability and cost in mind. The article contains numerous graphs from practical measurements. The outcome of the work and its possible future is defined in the conclusion.

  8. Grain size dependent phase stabilities and presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} piezoceramics

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Ashutosh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2015-04-14

    Results of the room temperature structural studies on (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} ceramics using Rietveld analysis of the powder x-ray diffraction data in the composition range 0.28 ≤ x ≤ 0.45 are presented. The morphotropic phase boundary region exhibits coexistence of monoclinic (space group Pm) and tetragonal (space group P4 mm) phases in the composition range 0.33 ≤ x ≤ 0.40. The structure is nearly single phase monoclinic (space group Pm) in the composition range 0.28 ≤ x ≤ 0.32. The structure for the compositions with x ≥ 0.45 is found to be predominantly tetragonal with space group P4 mm. Rietveld refinement of the structure rules out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier authors. The Rietveld structure analysis for the sample x = .35 calcined at various temperatures reveals that phase fraction of the coexisting phases in the morphotropic phase boundary region varies with grain size. The structural parameters of the two coexisting phases also change slightly with changing grain size.

  9. Mechanistic insights into a novel chromone-appended Cu(II) anticancer drug entity: in vitro binding profile with DNA/RNA substrates and cytotoxic activity against MCF-7 and HepG2 cancer cells.

    Science.gov (United States)

    Yousuf, Imtiyaz; Arjmand, Farukh; Tabassum, Sartaj; Toupet, Loic; Khan, Rais Ahmad; Siddiqui, Maqsood Ahmad

    2015-06-14

    A new chromone-appended Cu(ii) drug entity () was designed and synthesized as a potential anticancer chemotherapeutic agent. The structural elucidation was carried out thoroughly by elemental analysis, FT-IR, EPR, ESI-MS and single crystal X-ray crystallography. Complex resulted from the in situ methoxylation reaction of the 3-formylchromone ligand and its subsequent complexation with the copper nitrate salt in a 2 : 1 ratio, respectively. crystallized in the monoclinic P21/c space group possessing the lattice parameters, a = 8.75 Å, b = 5.07 Å, c = 26.22 Å, α = γ = 90°, β = 96.3° per unit cell. Furthermore, in vitro interaction studies of with ct-DNA and tRNA were carried out which suggested more avid binding propensity towards the RNA target via intercalative mode, which was reflected from its Kb, K and Ksv values. The gel electrophoretic mobility assay was carried out on the pBR322 plasmid DNA substrate, to ascertain the cleaving ability and the mechanistic pathway in the presence of additives, and the results revealed the efficient cleaving ability of via the oxidative pathway. In vitro cell growth inhibition via the MTT assay was carried out to evaluate the cytotoxicity of complex and IC50 values were found to be in the range of 5-10 μg mL(-1) in HepG2 and MCF-7 cancer cell lines, which were found to be much lower than the IC50 values of previously reported similar Cu(ii) complexes. Additionally, in the presence of , reactive oxygen species (ROS) and thiobarbituric acid reactive substance (TBARS) levels in the tested cancer cell lines increased significantly, coupled with reduced glutathione (GSH) levels. Thus, our results suggested that ROS plays an important role in cell apoptosis induced by the Cu(ii) complex and validates its potential to act as a robust anticancer drug entity.

  10. Adverse events following vaccination with an inactivated, Vero cell culture-derived Japanese encephalitis vaccine in the United States, 2009-2012.

    Science.gov (United States)

    Rabe, Ingrid B; Miller, Elaine R; Fischer, Marc; Hills, Susan L

    2015-01-29

    In March 2009, the U.S. Food and Drug Administration licensed an inactivated, Vero cell culture-derived Japanese encephalitis vaccine (JE-VC [Ixiaro]) for use in adults. The vaccine was licensed based on clinical trial safety data in 3558 JE-VC recipients. It is essential to monitor post-licensure surveillance data to evaluate the safety of JE-VC because rare adverse events may not be detected until the vaccine is administered to a larger population. We reviewed adverse events reported to the U.S. Vaccine Adverse Event Reporting System (VAERS) for adults (≥17 years) who received JE-VC from May 2009 through April 2012. Adverse event reporting rates were calculated using 275,848 JE-VC doses distributed. Over the 3 year period, 42 adverse events following vaccination with JE-VC were reported to VAERS for an overall reporting rate of 15.2 adverse events per 100,000 doses distributed. Of the 42 total reports, 5 (12%) were classified as serious for a reporting rate of 1.8 per 100,000 doses distributed; there were no deaths. Hypersensitivity reactions (N=12) were the most commonly reported type of adverse event, with a rate of 4.4 per 100,000 doses distributed; no cases of anaphylaxis were reported. Three adverse events of the central nervous system were reported (one case of encephalitis and two seizures) for a rate of 1.1 per 100,000; all occurred after receipt of JE-VC with other vaccines. These post-marketing surveillance data suggest a good safety profile for JE-VC consistent with findings from pre-licensure clinical trials. Post-licensure safety data should continue to be monitored for any evidence of rare serious or neurologic adverse events. Published by Elsevier Ltd.

  11. Malaria Treatment (United States)

    Science.gov (United States)

    ... a CDC Malaria Branch clinician. malaria@cdc.gov Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version ...

  12. United Cerebral Palsy

    Science.gov (United States)

    ... be sure to follow us on Twitter . United Cerebral Palsy UCP educates, advocates and provides support services to ... Partners Merz Logo Sprint Relay Copyright © 2015 United Cerebral Palsy 1825 K Street NW Suite 600 Washington, DC ...

  13. Unit Cost Compendium Calculations

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Unit Cost Compendium (UCC) Calculations raw data set was designed to provide for greater accuracy and consistency in the use of unit costs across the USEPA...

  14. Establishing the Intermediate Unit.

    Science.gov (United States)

    Pennsylvania State Dept. of Education, Harrisburg.

    The State of Pennsylvania Act 102 establishes a system of 29 intermediate units, creates intermediate unit boards of directors, spells out their duties and functions, and provides a system of financing their operations. This handbook has been prepared by the Pennsylvania Department of Education to provide intermediate unit boards of directors,…

  15. Unitals in Projective Planes

    CERN Document Server

    Barwick, Susan

    2008-01-01

    Unitals are key structures in projective planes, and have connections with other structures in algebra. This book presents a monograph on unitals embedded in finite projective planes. It offers a survey of the research literature on embedded unitals. It is suitable for graduate students and researchers who want to learn about this topic

  16. On spiking units in the first optic chiasm of the blowfly. III. The sustaining unit

    NARCIS (Netherlands)

    Jansonius, N.M.; Hateren, J.H. van

    1993-01-01

    We recorded from the spiking sustaining unit in the optic chiasm between lamina and medulla in the brain of the blowfly Calliphora vicina, and investigated both temporal and spatial properties of the light-adapted cell. The sustaining unit fails to follow the highest temporal frequencies followed by

  17. ON SPIKING UNITS IN THE 1ST OPTIC CHIASM OF THE BLOWFLY .3. THE SUSTAINING UNIT

    NARCIS (Netherlands)

    JANSONIUS, NM; VANHATEREN, JH

    We recorded from the spiking sustaining unit in the optic chiasm between lamina and medulla in the brain of the blowfly Calliphora vicina, and investigated both temporal and spatial properties of the light-adapted cell. The sustaining unit fails to follow the highest temporal frequencies followed by

  18. On spiking units in the first optic chiasm of the blowfly. III. The sustaining unit

    NARCIS (Netherlands)

    Jansonius, N.M.; Hateren, J.H. van

    1993-01-01

    We recorded from the spiking sustaining unit in the optic chiasm between lamina and medulla in the brain of the blowfly Calliphora vicina, and investigated both temporal and spatial properties of the light-adapted cell. The sustaining unit fails to follow the highest temporal frequencies followed by

  19. ON SPIKING UNITS IN THE 1ST OPTIC CHIASM OF THE BLOWFLY .3. THE SUSTAINING UNIT

    NARCIS (Netherlands)

    JANSONIUS, NM; VANHATEREN, JH

    1993-01-01

    We recorded from the spiking sustaining unit in the optic chiasm between lamina and medulla in the brain of the blowfly Calliphora vicina, and investigated both temporal and spatial properties of the light-adapted cell. The sustaining unit fails to follow the highest temporal frequencies followed by

  20. ON SPIKING UNITS IN THE 1ST OPTIC CHIASM OF THE BLOWFLY .3. THE SUSTAINING UNIT

    NARCIS (Netherlands)

    JANSONIUS, NM; VANHATEREN, JH

    1993-01-01

    We recorded from the spiking sustaining unit in the optic chiasm between lamina and medulla in the brain of the blowfly Calliphora vicina, and investigated both temporal and spatial properties of the light-adapted cell. The sustaining unit fails to follow the highest temporal frequencies followed by