Sample records for weakly pinned crystal

  1. Critical points in the Bragg glass phase of a weakly pinned crystal of ...

    Indian Academy of Sciences (India)

    magnetization hysteresis width ∆M(H) (∝ critical current density Jc(H)) in isothermal. M–H scans in a weakly ... dependence in Jc(H) in the tracing of the minor hysteresis loops, imply that the partially disordered state heals ... the elasticity of the vortex lattice rapidly start to collapse in a different manner, while approaching the.

  2. Computing the crystal growth rate by the interface pinning method

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Hummel, Felix; Dellago, Christoph


    An essential parameter for crystal growth is the kinetic coefficient given by the proportionality between supercooling and average growth velocity. Here, we show that this coefficient can be computed in a single equilibrium simulation using the interface pinning method where two......-phase configurations are stabilized by adding a spring-like bias field coupling to an order-parameter that discriminates between the two phases. Crystal growth is a Smoluchowski process and the crystal growth rate can, therefore, be computed from the terminal exponential relaxation of the order parameter. The approach...... from first principles. A generalized version of the method may be used for computing the rates of crystal nucleation or other rare events....

  3. Controlling inplane orientation of a monolayer colloidal crystal by meniscus pinning. (United States)

    Ng, Eric Chin Hong; Chin, Kah Mun; Wong, C C


    We demonstrate the usage of meniscus pinning by surface relief boundaries to control in-plane orientation of monolayer colloidal crystals without the interruption of grain disorientation. By optimizing the pinning boundary and withdrawal speed, a well controlled linear meniscus contact line offers unidirectional growth of a colloidal crystal-densely packed crystal direction ⟨11⟩ and ⟨10⟩ parallel to linear edge-giving rise to a single domain crystal with only twins and vacancies present as residual defects. The pinning effect works by eliminating the wavy contact line induced by fingering instability which is commonly found in liquid wetting film. It is found that surfactants and colloidal particles play significant roles to enhance edge pinning, increasing the distance traveled by receding bulk meniscus (during substrate withdrawal) before liquid depinning or rupturing.

  4. Improved pinning regime by energetic ions using reduction of pinning potential

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy; Gandini, Alberto; Sawh, Ravi-Persad; Parks, Drew; Mayes, Bill


    When ion damage is used to create pinning centers, full columnar pinning centers provide the largest pinning potential, U{sub pin}, but not the greatest J{sub c} or pinned field, B{sub pin}. Some of the characteristics of columnar defects which limit J{sub c} and B{sub pin} are discussed, including reduction of percolation path, and the need for a larger number of columns of damage, for pinning, than are usually estimated. It is concluded that columnar pinning centers are limited to B{sub pin}<4 T, and also severely reduce J{sub c}. Evidence is reviewed that aligned damage, or broken-columnar pinning centers, described herein, can provide orders of magnitude higher J{sub c}, and higher pinned field, despite providing lower U{sub pin}. A pinning center morphology is discussed which utilizes multiple-in-line-damage (MILD). For, e.g., present day large grain HTS J{sub c}, obtainable by MILD pinning, is estimated to be of the order of 10{sup 6} A/cm{sup 2} at 77 K, even when crystal plane alignment and weak links are not improved. Pinned field is increased by over an order of magnitude. An experiment is proposed to confirm these observations, and to directly compare MILD to columnar pinning centers. It will also determine the optimum MILD structure. Other measurements of interest, made possible by the same data set, are described.

  5. Improved pinning by multiple in-line damage

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Sawh, Ravi-Persad [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Gandini, Alberto [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Parks, Drew [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States)


    Columnar pinning centres provide the largest pinning potential, U{sub pin}, but not the greatest J{sub c} or pinnable field, B{sub pin}. Characteristics of ion-generated columnar defects which limit J{sub c} and B{sub pin} are discussed, including reduction of the percolation path, and the need for a larger number of columns of damage, for pinning, than are usually estimated. It is concluded that columnar pinning centres limit B{sub pin} to less than 4 T, and also severely reduce J{sub c}. The goal of maximizing U{sub pin}, via columnar centres, appears to have obscured a more rewarding approach and resulted in neglect of a large regime of ion interactions. Evidence is reviewed that multiple in-line damage (MILD), described herein, can provide orders of magnitude higher J{sub c} and B{sub pin}, despite providing lower U{sub pin}. The MILD pinning centre morphology is discussed, and it is estimated that for present-day large grain high T{sub c} superconductors, a J{sub c} value of {approx}10{sup 6}Acm{sup -2} is obtainable at 77 K, even when crystal plane alignment and weak links are not improved. In addition, the pinned field is increased by over an order of magnitude. An experiment is proposed to confirm these calculations, directly compare MILD pinning to continuous columnar pinning, and determine the optimum MILD structure. Applications of MILD pinning are discussed.

  6. Vortex states near absolute zero in a weak-pinning amorphous Mo x Ge1-x film probed by pulsed mode-locking resonance (United States)

    Sohara, N.; Ochi, A.; Murakami, E.; Ienaga, K.; Kaneko, S.; Kokubo, N.; Okuma, S.


    We have developed measurements of the mode-locking (ML) resonance with pulsed currents, which generates much less heat than the conventional one with continuous currents. Here, we present the experimental details of the pulsed ML measurement. Using this technique, we have succeeded in determining the dynamic melting field of a driven vortex lattice for a weak-pinning thick amorphous Mo x Ge1-x film down to 0.05 K. We construct an ideal vortex phase diagram in the absence of pinning near zero temperature as a function of magnetic field.

  7. Vortex phase diagram studies in the weakly pinned single crystals of ...

    Indian Academy of Sciences (India)

    According to the LO theory, Jc is inversely proportional to the square root of Vc. An anomalous increase in Jc, therefore, implies a reduction in the correlation volume Vc [5]. The PE thus marks a transition from an ordered flux line lattice to a disordered vortex state. Apart from the PE anomaly, another anomalous feature in the ...

  8. Vortex phase diagram studies in the weakly pinned single crystals of ...

    Indian Academy of Sciences (India)

    Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India; Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA; Ames Laboratory, Iowa State University, Ames, Iowa, 50011, USA; National Institute ...

  9. Performance of direct-driven flapping-wing actuator with piezoelectric single-crystal PIN-PMN-PT (United States)

    Ozaki, Takashi; Hamaguchi, Kanae


    We present a prototype flapping-wing actuator with a direct-driven mechanism to generate lift in micro- and nano-aerial vehicles. This mechanism has an advantage of simplicity because it has no transmission system between the actuator and wing. We fabricated the piezoelectric unimorph actuator from single-crystal PIN-PMN-PT, which achieved a lift force up to 1.45 mN, a value about 1.9 times larger than the mass of the actuator itself. This is the first reported demonstration of an insect-scale actuator with a direct-driven mechanism that can generate a lift force greater than its own weight.

  10. Experimental studies of two-dimensional colloidal crystals: Defects, pinning and driven dynamics (United States)

    Pertsinidis, Alexandros

    We present a series of experimental investigations of two-dimensional colloidal crystals (2D CC). The techniques used are digital video microscopy combined with optical tweezers and preparation of micro-lithographic substrates. In our first study we focused on the properties of point defects in the 2D CC. Point defects were created by manipulating the colloidal particles using optical tweezers. We found that the equilibrium configurations of mono- and di-vacancies have lower symmetry than the triangular lattice. Also, a di-vacancy can break into a dislocation pair, a process that enhances its diffusion. Furthermore, the hopping of the defects shows surprising memory effects. We also investigated the dynamics of dislocations during the visco-plastic deformation of a 2D CC. Dislocations are arranged in a cellular structure. We discovered that dislocations move in an intermittent fashion, giving rise to sudden bursts of activity. These events coincide with collective rearrangements and their statistics follow power-law behavior. Finally, we present results for 2D colloids interacting with disordered substrates. For weak disorder we observe an ordered state, containing no defects, whereas for strong disorder the system is in an amorphous state. We drive the particles electrophoretically and observe an elastic depinning transition for the ordered state, in which the system maintains its connectivity during motion. For strong disorder we observe plastic flow above the depinning threshold, with the system broken into stationary and flowing regions.

  11. Design of weak link channel-cut crystals for fast QEXAFS monochromators

    Energy Technology Data Exchange (ETDEWEB)

    Polheim, O. von, E-mail:; Müller, O.; Lützenkirchen-Hecht, D.; Frahm, R. [Department of Physics, University of Wuppertal, Gaußstraße 20, 42119 Wuppertal (Germany)


    A weak link channel-cut crystal, optimized for dedicated Quick EXAFS monochromators and measurements, was designed using finite element analysis. This channel-cut crystal offers precise detuning capabilities to enable suppression of higher harmonics in the virtually monochromatic beam. It was optimized to keep the detuning stable, withstanding the mechanical load, which occurs during oscillations with up to 50 Hz. First tests at DELTA (Dortmund, Germany), proved the design.

  12. Critical current density and vortex pinning mechanism of Li x (NH3) y Fe2Te{}_{1.2}Se{}_{0.8} single crystals (United States)

    Wang, Shaohua; Sun, Shanshan; Lei, Hechang


    We grew Li x (NH3) y Fe2Te{}1.2Se{}0.8 single crystals successfully using the low-temperature ammonothermal method, and the onset superconducting transition temperature {T}{{c}}{onset} is increased to 21 K compared to 14 K in the parent compound FeTe{}0.6Se{}0.4. The derived critical current density J c increases remarkably to 2.6 × 105 A/cm2 at 2 K. Further analysis indicates that the dominant pinning mechanism in Li x (NH3) y Fe2Te{}1.2Se{}0.8 single crystal is the interaction between vortex and surface-like defects with normal core, by variations in the charge-carrier mean free path l near the defects (δ l pinning). Moreover, flux creep is important to the vortex dynamics of this material.

  13. Topological polymer dispersed liquid crystals with bulk nematic defect lines pinned to handlebody surfaces. (United States)

    Campbell, Michael G; Tasinkevych, Mykola; Smalyukh, Ivan I


    Polymer dispersed liquid crystals are a useful model system for studying the relationship between surface topology and defect structures. They are comprised of a polymer matrix with suspended spherical nematic drops and are topologically constrained to host defects of an elementary hedgehog charge per droplet, such as bulk or surface point defects or closed disclination loops. We control the genus of the closed surfaces confining such micrometer-sized nematic drops with tangential boundary conditions for molecular alignment imposed by the polymer matrix, allowing us to avoid defects or, on the contrary, to generate them in a controlled way. We show, both experimentally and through numerical modeling, that topological constraints in nematic microdrops can be satisfied by hosting topologically stable half-integer bulk defect lines anchored to opposite sides of handlebody surfaces. This enriches the interplay of topologies of closed surfaces and fields with nonpolar symmetry, yielding new unexpected configurations that cannot be realized in vector fields, having potential implications for topologically similar defects in cosmology and other fields.

  14. Microstructure and Pinning Properties of Hexagonal Disc Shaped Single Crystalline MgB2

    Energy Technology Data Exchange (ETDEWEB)

    Patel, J. R.


    We synthesized hexagonal-disc-shaped MgB{sub 2} single crystals under high-pressure conditions and analyzed the microstructure and pinning properties. The lattice constants and the Laue pattern of the crystals from X-ray micro-diffraction showed the crystal symmetry of MgB{sub 2}. A thorough crystallographic mapping within a single crystal showed that the edge and c-axis of hexagonal-disc shape exactly matched the (10-10) and the (0001) directions of the MgB{sub 2} phase. Thus, these well-shaped single crystals may be the best candidates for studying the direction dependences of the physical properties. The magnetization curve and the magnetic hysteresis for these single crystals showed the existence of a wide reversible region and weak pinning properties, which supported our single crystals being very clean.

  15. A plastic-composite-plastic structure high performance flexible energy harvester based on PIN-PMN-PT single crystal/epoxy 2-2 composite (United States)

    Zeng, Zhou; Gai, Linlin; Wang, Xian; Lin, Di; Wang, Sheng; Luo, Haosu; Wang, Dong


    We present a high performance flexible piezoelectric energy harvester constituted by a Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystal/epoxy 2-2 composite flake, a polyethylene terephthalate (PET) substrate, and a PET cover, which is capable of harvesting energy from biomechanical movements. Electrical properties of the device under different epoxy volume fractions, load resistances, and strains are studied systematically. Both theoretical and experimental results show that the plastic-composite-plastic structure contributes to the flexibility of the device, and a high performance bulk PIN-PMN-PT single crystal (a thickness of 50 μm) results in its high electrical output. At a low excitation frequency of 4.2 Hz, the optimal flexible energy harvester (with ve = 21%) can generate a peak voltage of 12.9 V and a maximum power density of 0.28 mW/cm3 under a bending radius of 10.5 mm, and maintain its performance after 40 000 bending-unbending cycles. High flexibility and excellent electrical output at low operational frequency demonstrate the promise of the device in biomechanical motion energy harvesting for wireless and portable low-power electronics.

  16. Electro-osmosis of nematic liquid crystals under weak anchoring and second-order surface effects (United States)

    Poddar, Antarip; Dhar, Jayabrata; Chakraborty, Suman


    Advent of nematic liquid crystal flows has attracted renewed attention in view of microfluidic transport phenomena. Among various transport processes, electro-osmosis stands as one of the efficient flow actuation mechanisms through narrow confinements. In the present study, we explore the electrically actuated flow of an ordered nematic fluid with ionic inclusions, taking into account the influences from surface-induced elasticity and electrical double layer (EDL) phenomena. Toward this, we devise the coupled flow governing equations from fundamental free-energy analysis, considering the contributions from first- and second-order elastic, dielectric, flexoelectric, charged surface polarization, ionic and entropic energies. The present study focuses on the influence of surface charge and elasticity effects in the resulting linear electro-osmosis through a slit-type microchannel whose surfaces are chemically treated to display a homeotropic-type weak anchoring state. An optical periodic stripe configuration of the nematic director has been observed, especially for higher electric fields, wherein the Ericksen number for the dynamic study is restricted to the order of unity. Contrary to the isotropic electrolytes, the EDL potential in this case was found to be dependent on the external field strength. Through a systematic investigation, we brought out the fact that the wavelength of the oscillating patterns is dictated mainly by the external field, while the amplitude depends on most of the physical variables ranging from the anchoring strength and the flexoelectric coefficients to the surface charge density and electrical double layer thickness.

  17. H- T- J phase diagram and pinning mechanism in Ba 0.63K 0.37BiO 3- y single crystals (United States)

    Barilo, S. N.; Hall, D.; Gatalskaya, V. I.; Smirnova, T. V.; Shiryaev, S. V.; Crow, J. E.


    The H-T-J phase diagram of superconducting Ba 1- xK xBiO 3- y ( x=0.37, 0.41, 0.5) single crystals has been studied by means of SQUID and cantilever force magnetometry. Strong upward curvature of the Hc2 ( T) dependence confirms at least intermediate strength of the electron-phonon coupling in this 3D-superconductor family. The normalized critical current deduced from a cantilever force response is well described by collective pinning theory in the temperature range 0.01 Tcmechanism related to the spatial fluctuations of the carrier mean free path does not allow pronounced anomalous magnetization over the whole temperature range studied.

  18. Happy Pinning

    DEFF Research Database (Denmark)

    Fausing, Bent


    This is about Pinterest, but with a different approach than usual to social networks. Pinterest is an image site par excellence. The images are as Windows that open outwards and also lets us look inwards and displays the soul and heart, the unintentional or pre-conscious desires. Happy Pinning!...

  19. Impedance of Polymer-Dispersed Liquid Crystals with Carbon Nanofibers in Weak Electric Fields (United States)

    Zhdanov, K. R.; Romanenko, A. I.; Zharkova, G. M.; Podyacheva, O. Yu.


    Impedance of polymer-dispersed liquid crystals modified by carbon nanofibers is studied in fields lower than the threshold field of the director reorientation of a liquid crystal. It is shown that the real and imaginary parts of the impedance obey to the relationship (Zre - X0)2 + (Zim - Y0)2 = R 0 2 , where X0, Y0, and R0 are the fitting parameters depending on the frequency of the exciting electric field.

  20. Cyclohexyl ketone inhibitors of Pin1 dock in a trans-diaxial cyclohexane conformation.

    Directory of Open Access Journals (Sweden)

    Guoyan G Xu

    Full Text Available Cyclohexyl ketone substrate analogue inhibitors (Ac-pSer-Ψ[C = OCH]-Pip-tryptamine of Pin1, the cell cycle regulatory peptidyl-prolyl isomerase (PPIase, were designed and synthesized as potential electrophilic acceptors for the Pin1 active site Cys113 nucleophile to test a proposed nucleophilic addition-isomerization mechanism. Because they were weak inhibitors, models of all three stereoisomers were docked into the active site of Pin1. Each isomer consistently minimized to a trans-diaxial cyclohexane conformation. From this, we hypothesize that Pin1 stretches substrates into a trans-pyrrolidine conformation to lower the barrier to isomerization. Our reduced amide inhibitor of Pin1 adopted a similar trans-pyrrolidine conformation in the crystal structure. The molecular model of 1, which mimics the l-Ser-l-Pro stereochemistry, in the Pin1 active site showed a distance of 4.4 Å, and an angle of 31° between Cys113-S and the ketone carbon. The computational models suggest that the mechanism of Pin1 PPIase is not likely to proceed through nucleophilic addition.

  1. Unusual pinning induced by vortex motion in YNi{sub 2}B{sub 2}C

    Energy Technology Data Exchange (ETDEWEB)

    Okuma, S., E-mail: [Research Center for Low Temperature Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Ichimura, T. [Research Center for Low Temperature Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Takeya, H.; Hirata, K. [National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki 305-0047 (Japan)


    We present measurements of current-voltage (I-V) characteristics and voltage noise S{sub V} generated by current-driven vortices for a YNi{sub 2}B{sub 2}C single crystal with weak-pinning. Nonmonotonic, N-shaped I-V curves are observed deep in the vortex-solid phase. In the intermediate I region where the unusual negative dV/dI is observed, S{sub V} exhibits a sharp peak. The result suggests vortex-motion-induced dynamic pinning.

  2. Collective vortex pinning and merging of the irreversibility line and second peak effect in optimally doped Ba1-xKxBiO3 single crystals (United States)

    Jiao, Yanjing; Cheng, Wang; Deng, Qiang; Yang, Huan; Wen, Hai-Hu


    Measurements on magnetization and relaxation have been carried out on an optimally doped Ba1-xKxBiO3+δ single crystal with Tc = 31.3 K. Detailed analysis is undertaken on the data. Both the dynamical relaxation and conventional relaxation have been measured leading to the self-consistent determination of the magnetization relaxation rate. It is found that the data are well described by the collective pinning model leading to the glassy exponent of about μ ≈ 1.64-1.68 with the magnetic fields of 1 and 3 T. The analysis based on Maley's method combining with the conventional relaxation data allows us to determine the current dependent activation energy U which yields a μ value of about 1.23-1.29 for the magnetic fields of 1 and 3 T. The second magnetization peaks appear in wide temperature region from 2 K to 24 K. The separation between the second peak field and the irreversibility field becomes narrow when temperature is increased. When the two fields are close to each other, we find that the second peak evolves into a step-like transition of magnetization. Finally, we present a vortex phase diagram and demonstrate that the vortex dynamics in Ba1-xKxBiO3 can be used as a model system for studying the collective vortex pining.

  3. Phase Energy Determined from Stress and Electric-Field-Induced Phase Transformations in [011]C Cut 0.24PIN-PMN-PT Single Crystals

    Directory of Open Access Journals (Sweden)

    Dorinamaria Carka


    Full Text Available The effect of composition and temperature on the large field behavior of [011]C cut and poled (d32-mode rhombohedral relaxor ferroelectric 0.24PIN-(1−xPMN-xPT single crystals was characterized under electromechanical loading and the relative phase energy determined. The electric field and stress induced polarization and strain response and field dependent material properties are reported for two concentrations of lead titanate (PT, with one PT concentration closer to the morphotropic phase boundary, at low and high temperature. A thermodynamic analysis to determine the relative energy levels of the rhombohedral and orthorhombic phases is based on the path integration of the measured data to determine external work done to drive the phase transition. The effect of heat generated by irreversible strain and electric displacement increments (hysteresis in the phase transformation was removed from the work done during the loading cycle and the relative Helmholtz free energy density levels of the phases was determined.

  4. Weak antibody-cyclodextrin interactions determined by quartz crystal microbalance and dynamic/static light scattering. (United States)

    Härtl, Elisabeth; Dixit, Nitin; Besheer, Ahmed; Kalonia, Devendra; Winter, Gerhard


    In a quest to elucidate the mechanism by which hydroxypropyl β-cyclodextrin (HPβCD) stabilizes antibodies against shaking stress, two heavily debated hypotheses exist, namely that stabilization is due to HPβCD's surface activity, or due to specific interactions with proteins. In a previous study by Serno et al. (Pharm. Res. 30 (2013) 117), we could refute the first hypothesis by proving that, although HPβCD is slightly surface active, it does not displace the antibody at the air-water interface, and accordingly, its surface activity is not the underlying stabilizing mechanism. In the present study, we investigated the possibility of interactions between HPβCD and monoclonal antibodies as the potential stabilization mechanism using quartz crystal microbalance (QCM) and static as well as dynamic light scattering. In the presence of HPβCD, the adsorption of IgG antibodies in the native state (IgG A) and the unfolded state (IgG A and IgG B) on gold-coated quartz crystals was studied by QCM. Results show that HPβCD causes a reduction in protein adsorption in both the folded and the unfolded states, probably due to an interaction between the protein and the cyclodextrin, leading to a reduced hydrophobicity of the protein and consequently a lower extent of adsorption. These results were supported by investigation of the interaction between the native protein and HPβCD using static and dynamic light scattering experiments, which provide the protein-protein interaction parameters, B22 and kD, respectively. Both B22 and kD showed an increase in magnitude with increasing HPβCD-concentrations, indicating a rise in net repulsive forces between the protein molecules. This is further evidence for the presence of interactions between HPβCD and the studied antibodies, since an association of HPβCD on the protein surface leads to a change in the intermolecular forces between the protein molecules. In conclusion, this study provides evidence that the previously observed

  5. Development of Polar Order by Liquid-Crystal Self-Assembly of Weakly Bent Molecules. (United States)

    Alaasar, Mohamed; Prehm, Marko; Poppe, Silvio; Tschierske, Carsten


    Organic ferroelectrics are of growing importance for multifunctional materials. Here we provide an understanding of the distinct stages of the development of sterically induced polar order in liquid-crystalline (LC) soft matter. Three series of weakly bent molecules derived from 4-cyanoresorcinol as the bent core unit with laterally fluorinated azobenzene wings have been synthesized, and the effects of the position of fluorine substitution, alkyl-chain length, and temperature on the LC self-assembly and polar order were studied. In the LC phases a paraelectric-ferroelectric transition took place as the size of the polar domains gradually increased, thereby crossing a permittivity maximum, similar to inorganic solid-state ferroelectrics. An increase in polar coherence length simultaneously led to a transition from synpolar to antipolar domain correlation in the high-permittivity paraelectric range. Associated with the emergence of polar order was the development of a tilted organization of the molecules and a growing coherence of tilt. This led to a transition from non-tilted via tilt-randomized uniaxial to long-range-tilted biaxial smectic phases, and to surface-stabilized symmetry breaking with the formation of chiral conglomerates and field-induced tilt. Moreover, there is a remarkably strong effect of the position of fluorination; polar order is favored by peripheral core substitution and is suppressed by inside-directed fluorination. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Monolayer Single-Crystal 1T'-MoTe2 Grown by Chemical Vapor Deposition Exhibits Weak Antilocalization Effect. (United States)

    Naylor, Carl H; Parkin, William M; Ping, Jinglei; Gao, Zhaoli; Zhou, Yu Ren; Kim, Youngkuk; Streller, Frank; Carpick, Robert W; Rappe, Andrew M; Drndić, Marija; Kikkawa, James M; Johnson, A T Charlie


    Growth of transition metal dichalcogenide (TMD) monolayers is of interest due to their unique electrical and optical properties. Films in the 2H and 1T phases have been widely studied but monolayers of some 1T'-TMDs are predicted to be large-gap quantum spin Hall insulators, suitable for innovative transistor structures that can be switched via a topological phase transition rather than conventional carrier depletion [ Qian et al. Science 2014 , 346 , 1344 - 1347 ]. Here we detail a reproducible method for chemical vapor deposition of monolayer, single-crystal flakes of 1T'-MoTe2. Atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy confirm the composition and structure of MoTe2 flakes. Variable temperature magnetotransport shows weak antilocalization at low temperatures, an effect seen in topological insulators and evidence of strong spin-orbit coupling. Our approach provides a pathway to systematic investigation of monolayer, single-crystal 1T'-MoTe2 and implementation in next-generation nanoelectronic devices.

  7. On Spectral Invariance of Single Scattering Albedo for Water Droplets and Ice Crystals at Weakly Absorbing Wavelengths (United States)

    Marshak, Alexander; Knyazikhin, Yuri; Chiu, J. Christine; Wiscombe, Warren J.


    The single scattering albedo omega(sub O lambda) in atmospheric radiative transfer is the ratio of the scattering coefficient to the extinction coefficient. For cloud water droplets both the scattering and absorption coefficients, thus the single scattering albedo, are functions of wavelength lambda and droplet size r. This note shows that for water droplets at weakly absorbing wavelengths, the ratio omega(sub O lambda)(r)/omega(sub O lambda)(r (sub O)) of two single scattering albedo spectra is a linear function of omega(sub O lambda)(r). The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo spectrum omega(sub O lambda)(r) via one known spectrum omega(sub O lambda)(r (sub O)). We provide a simple physical explanation of the discovered relationship. Similar linear relationships were found for the single scattering albedo spectra of non-spherical ice crystals.

  8. Low-temperature (<200 oC solid-phase crystallization of high substitutional Sn concentration (∼10% GeSn on insulator enhanced by weak laser irradiation

    Directory of Open Access Journals (Sweden)

    Kenta Moto


    Full Text Available Low temperature (8% on insulating substrates is essential to realize next generation flexible electronics. To achieve this, a growth method of high quality GeSn films on insulating substrates by combination of laser irradiation and subsequent thermal annealing is developed. Here, the laser fluence is chosen as weak, which is below the critical fluence for crystallization of GeSn. It is clarified that for samples irradiated with weak laser fluence, complete crystallization of GeSn films is achieved by subsequent thermal annealing at ∼170 oC without incubation time. In addition, the quality of GeSn films obtained by this method is higher compared with conventional growth techniques such as melting growth by pulsed laser annealing or solid-phase crystallization (SPC without pre-laser irradiation. Substitutional Sn concentrations in the grown layers estimated by Raman spectroscopy measurements are 8-10%, which far exceed thermal equilibrium solid-solubility of Sn in Ge (∼2%. These phenomena are explained by generation of a limited number of nuclei by weak laser irradiation and lateral SPC by subsequent thermal annealing. This method will facilitate realization of next-generation high performance devices on flexible insulating substrates.

  9. Hitting the target: fragment screening with acoustic in situ co-crystallization of proteins plus fragment libraries on pin-mounted data-collection micromeshes. (United States)

    Yin, Xingyu; Scalia, Alexander; Leroy, Ludmila; Cuttitta, Christina M; Polizzo, Gina M; Ericson, Daniel L; Roessler, Christian G; Campos, Olven; Ma, Millie Y; Agarwal, Rakhi; Jackimowicz, Rick; Allaire, Marc; Orville, Allen M; Sweet, Robert M; Soares, Alexei S


    Acoustic droplet ejection (ADE) is a powerful technology that supports crystallographic applications such as growing, improving and manipulating protein crystals. A fragment-screening strategy is described that uses ADE to co-crystallize proteins with fragment libraries directly on MiTeGen MicroMeshes. Co-crystallization trials can be prepared rapidly and economically. The high speed of specimen preparation and the low consumption of fragment and protein allow the use of individual rather than pooled fragments. The Echo 550 liquid-handling instrument (Labcyte Inc., Sunnyvale, California, USA) generates droplets with accurate trajectories, which allows multiple co-crystallization experiments to be discretely positioned on a single data-collection micromesh. This accuracy also allows all components to be transferred through small apertures. Consequently, the crystallization tray is in equilibrium with the reservoir before, during and after the transfer of protein, precipitant and fragment to the micromesh on which crystallization will occur. This strict control of the specimen environment means that the crystallography experiments remain identical as the working volumes are decreased from the few microlitres level to the few nanolitres level. Using this system, lysozyme, thermolysin, trypsin and stachydrine demethylase crystals were co-crystallized with a small 33-compound mini-library to search for fragment hits. This technology pushes towards a much faster, more automated and more flexible strategy for structure-based drug discovery using as little as 2.5 nl of each major component.

  10. Nuclear fuel pin scanner (United States)

    Bramblett, Richard L.; Preskitt, Charles A.


    Systems and methods for inspection of nuclear fuel pins to determine fiss loading and uniformity. The system includes infeed mechanisms which stockpile, identify and install nuclear fuel pins into an irradiator. The irradiator provides extended activation times using an approximately cylindrical arrangement of numerous fuel pins. The fuel pins can be arranged in a magazine which is rotated about a longitudinal axis of rotation. A source of activating radiation is positioned equidistant from the fuel pins along the longitudinal axis of rotation. The source of activating radiation is preferably oscillated along the axis to uniformly activate the fuel pins. A detector is provided downstream of the irradiator. The detector uses a plurality of detector elements arranged in an axial array. Each detector element inspects a segment of the fuel pin. The activated fuel pin being inspected in the detector is oscillated repeatedly over a distance equal to the spacing between adjacent detector elements, thereby multiplying the effective time available for detecting radiation emissions from the activated fuel pin.

  11. Multicenter pin care study. (United States)

    Patterson, Miki M


    Pin-site infection is a common complication of external fixation. Because few studies have compared methods of pin care that reduce infection rate, there is a need for evidence-based practice guidelines for pin-site care. Two of 10 original clinical centers completed a prospective, randomized pin-care study between May 2000 and May 2002 to determine which of seven methods for caring for skeletal pins (external fixator, traction, or halo) resulted in the fewest pin-site infections. The 92 subjects had an average infection rate of 34%, and the 527 pins had a rate of 20%. Thirty patients (98 pins) had stage II infections, two patients (12 pins) had stage III infections, and none had deep infection or osteomyelitis. The protocols were (1) half-strength peroxide cleansing and gauze wraps (45%), (2) half-strength peroxide cleansing and Xeroform wraps (9%), (3) saline cleansing and gauze wraps (33%), (4) saline cleansing and Xeroform wraps (26%), (5) antibacterial soap-and-water cleansing and gauze (38%), (6) antibacterial soap-and-water cleansing and Xeroform gauze (50%), and (7) stable dressings with no pin cleansing (36%). Logistic regression analysis demonstrated significant inverse relationships (p = .05) between infection rate and age, as well as fixator type; the latter may be related to exposed threads. Results suggest that other factors outside the realm of this study may affect children's pin-site infection rate and that half-strength peroxide and Xeroform dressings were superior to soap-and-water cleansing. This pilot study indicates a need for further research with a larger sample size and for exploring factors in a younger population.

  12. Linear and nonlinear discrete light propagation in weakly modulated large-area two-dimensional photonic lattice slab in LiNbO3:Fe crystal. (United States)

    Qi, Xinyuan; Zhang, Guoquan; Xu, Ningning; Qi, Yiling; Han, Bin; Fu, Yulan; Duan, Changsha; Xu, Jingjun


    A weakly modulated large-area two-dimensional square photonic lattice slab was fabricated through optical induction technique in a photorefractive photovoltaic LiNbO(3):Fe crystal. Bragg-matched diffraction technique was used to characterize the square photonic lattice slab. Interestingly, linear discrete diffraction typical for waveguide arrays was observed in such a square photonic lattice slab, indicating that the lattice slab can be viewed effectively as a one-dimensional waveguide array. Furthermore, discrete soliton was demonstrated in the photonic lattice slab due to a saturable self-defocusing nonlinearity arising from the bulk photorefractive photovoltaic effect of LiNbO(3):Fe.

  13. PINS Spectrum Identification Guide

    Energy Technology Data Exchange (ETDEWEB)

    A.J. Caffrey


    The Portable Isotopic Neutron Spectroscopy—PINS, for short—system identifies the chemicals inside munitions and containers without opening them, a decided safety advantage if the fill chemical is a hazardous substance like a chemical warfare agent or an explosive. The PINS Spectrum Identification Guide is intended as a reference for technical professionals responsible for the interpretation of PINS gamma-ray spectra. The guide is divided into two parts. The three chapters that constitute Part I cover the science and technology of PINS. Neutron activation analysis is the focus of Chapter 1. Chapter 2 explores PINS hardware, software, and related operational issues. Gamma-ray spectral analysis basics are introduced in Chapter 3. The six chapters of Part II cover the identification of PINS spectra in detail. Like the PINS decision tree logic, these chapters are organized by chemical element: phosphorus-based chemicals, chlorine-based chemicals, etc. These descriptions of hazardous, toxic, and/or explosive chemicals conclude with a chapter on the identification of the inert chemicals, e.g. sand, used to fill practice munitions.

  14. Evidence for weakly bound electrons in non-irradiated alkane crystals: The electrons as a probe of structural differences in crystals. (United States)

    Pietrow, M; Gagoś, M; Misiak, L E; Kornarzyński, K; Szurkowski, J; Rochowski, P; Grzegorczyk, M


    It is generally assumed that weakly bound (trapped) electrons in organic solids come only from radiolytical (or photochemical) processes like ionization caused by an excited positron entering the sample. This paper presents evidence for the presence of these electrons in non-irradiated samples of docosane. This can be due to the triboelectrification process. We argue that these electrons can be located (trapped) either in interlamellar gaps or in spaces made by non-planar conformers. Electrons from the former ones are bound more weakly than electrons from the latter ones. The origin of Vis absorption for the samples is explained. These spectra can be used as a probe indicating differences in the solid structures of hydrocarbons.

  15. Flux Pinning in Superconductors

    CERN Document Server

    Matsushita, Teruo


    The book covers the flux pinning mechanisms and properties and the electromagnetic phenomena caused by the flux pinning common for metallic, high-Tc and MgB2 superconductors. The condensation energy interaction known for normal precipitates or grain boundaries and the kinetic energy interaction proposed for artificial Nb pins in Nb-Ti, etc., are introduced for the pinning mechanism. Summation theories to derive the critical current density are discussed in detail. Irreversible magnetization and AC loss caused by the flux pinning are also discussed. The loss originally stems from the ohmic dissipation of normal electrons in the normal core driven by the electric field induced by the flux motion. The readers will learn why the resultant loss is of hysteresis type in spite of such mechanism. The influence of the flux pinning on the vortex phase diagram in high Tc superconductors is discussed, and the dependencies of the irreversibility field are also described on other quantities such as anisotropy of supercondu...

  16. Flux pinning in superconductors

    CERN Document Server

    Matsushita, Teruo


    The book covers the flux pinning mechanisms and properties and the electromagnetic phenomena caused by the flux pinning common for metallic, high-Tc and MgB2 superconductors. The condensation energy interaction known for normal precipitates or grain boundaries and the kinetic energy interaction proposed for artificial Nb pins in Nb-Ti, etc., are introduced for the pinning mechanism. Summation theories to derive the critical current density are discussed in detail. Irreversible magnetization and AC loss caused by the flux pinning are also discussed. The loss originally stems from the ohmic dissipation of normal electrons in the normal core driven by the electric field induced by the flux motion. The readers will learn why the resultant loss is of hysteresis type in spite of such mechanism. The influence of the flux pinning on the vortex phase diagram in high Tc superconductors is discussed, and the dependencies of the irreversibility field are also described on other quantities such as anisotropy of supercondu...

  17. Epigallocatechin-gallate suppresses tumorigenesis by directly targeting Pin1 (United States)

    Urusova, Darya V.; Shim, Jung-Hyun; Kim, Dong Joon; Jung, Sung Keun; Zykova, Tatyana A.; Carper, Andria; Bode, Ann M.; Dong, Zigang


    The most active anticancer component in green tea is epigallocatechin-3-gallate (EGCG). The human peptidyl prolyl cis/trans isomerase (Pin1) plays a critical role in oncogenic signaling. Herein, we report the X-ray crystal structure of the Pin1/EGCG complex resolved at 1.9 Å resolution. Notably, the structure revealed the presence of EGCG in both the WW and PPIase domains of Pin1. The direct binding of EGCG with Pin1 was confirmed and the interaction inhibited Pin1 PPlase activity. In addition, proliferation of cells expressing Pin1 was inhibited and tumor growth in a xenograft mouse model was suppressed. The binding of EGCG with Arg17 in the WW domain prevented the binding of c-Jun, a well-known Pin1 substrate. EGCG treatment corresponded with a decreased abundance of cyclin D1 and diminution of TPA-induced AP-1 or NFκB promoter activity in cells expressing Pin1. Overall, these results showed that EGCG directly suppresses the tumor promoting effect of Pin1. PMID:21750208

  18. Epigallocatechin-gallate Suppresses Tumorigenesis by Directly Targeting Pin1

    Energy Technology Data Exchange (ETDEWEB)

    Urusova, Darya V. [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.; Shim, Jung-Hyun [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.; Soonchunhyang Univ., Cheonan (Korea, Republic of). Dept. of Biochemistry; Kim, Dong Joon [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.; Jung, Sung Keun [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.; Zykova, Tatyana A. [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.; Carper, Andria [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.; Bode, Ann M. [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.; Dong, Zigang [Univ. of Minnesota, Austin, MN (United States). Hormel Inst.


    The most active anticancer component in green tea is epigallocatechin-3-gallate (EGCG). The human peptidyl prolyl cis/trans isomerase (Pin1) plays a critical role in oncogenic signaling. Herein, we report the X-ray crystal structure of the Pin1/EGCG complex resolved at 1.9 Å resolution. Notably, the structure revealed the presence of EGCG in both the WW and PPIase domains of Pin1. The direct binding of EGCG with Pin1 was confirmed and the interaction inhibited Pin1 PPIase activity. In addition, proliferation of cells expressing Pin1 was inhibited and tumor growth in a xenograft mouse model was suppressed. The binding of EGCG with Arg17 in the WW domain prevented the binding of c-Jun, a well-known Pin1 substrate. EGCG treatment corresponded with a decreased abundance of cyclin D1 and diminution of 12-O-tetradecanoylphorbol-l3-acetate–induced AP-1 or NF-κB promoter activity in cells expressing Pin1. Overall, these results showed that EGCG directly suppresses the tumor-promoting effect of Pin1.

  19. Liquid Drop Pinning on Micro-patterned Surfaces (United States)

    Soliman, Ahmed; Kalinin, Yevgeniy; Baur, Robin; Thorne, Robert


    Pinning of liquid drops on surfaces is important in many areas of biotechnology. Micro-patterned surfaces provide a way to control drop pinning, and to investigate the mechanisms of pinning on real (rough) surfaces. Continuous circular rings on silicon wafers produced by etching the interior and surrounding silicon are shown to dramatically increase contact line pinning. The critical apparent contact angles and liquid drop volumes are measured and correlated with parameters that describe the ring geometry, such as ring-wall height and width, as well as with ring surface energy (hydrophilicity / hydrophobicity). Micro-patterning of surfaces in this way can be used to improve drop pinning, shape reproducibility and imaging in high-throughput protein crystallization.

  20. A pinning puzzle: two similar, non-superconducting chemical deposits in YBCO-one pins, the other does not

    Energy Technology Data Exchange (ETDEWEB)

    Sawh, Ravi-Persad; Weinstein, Roy; Gandini, Alberto; Skorpenske, Harley; Parks, Drew, E-mail: Weinstein@uh.ed [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Department of Physics, University of Houston, Houston, TX 77204-5005 (United States); Texas Center for Superconductivity at UH, University of Houston, Houston, TX 77204-5002 (United States)


    The pinning effects of two kinds of U-rich deposits in YBCO (YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}) are compared. One is a five-element compound, (U{sub 0.6}Pt{sub 0.4})YBa{sub 2}O{sub 6}, which is a paramagnetic double perovskite which forms as profuse stable nanosize deposits, and pins very well. The other is a four-element compound, (U{sub 0.4}Y{sub 0.6})BaO{sub 3}, which is a ferromagnetic single perovskite which forms as profuse stable nanosize deposits and pins very weakly or not at all. The pinning comparison is done with nearly equal deposit sizes and number of deposits per unit volume for the two compounds. Evidence for the pinning capability, chemical makeup, x-ray diffraction signature, and magnetic properties of the two compounds is reported.

  1. Weak ferromagnetic behavior, crystal structure, and electronic studies of novel [Cu(II)(Br)(PhCO 2)(Sp)] (Sp=(-)-sparteine) complex (United States)

    Reyes-Ortega, Yasmi; Alcántara-Flores, José Luis; Hernández-Galindo, María del Carmen; Gutiérrez-Pérez, René; Ramírez-Rosales, Daniel; Bernès, Sylvain; Cabrera-Vivas, Blanca Martha; Durán-Hernández, Alejandro; Zamorano-Ulloa, Rafael


    Complex [Cu(II)(Br)(PhCO 2)(Sp)] 1 is obtained starting from copper(0), (-)-sparteine (sp) and benzoyl bromide. 1 Crystallizes in the monoclinic space group P2 1 with a=14.8857(11), b=8.9257(9), c=17.4456(14) Å, β=111.689(5)°, and Z=4. The UV-vis spectrum is characteristic of Cu(II) complexes with tetragonally distorted square pyramidal geometry. The far IR spectrum of 1 shows characteristic vibrations of Cu-Br (239 cm -1), Cu-N (437 cm -1) and Cu-O (466 cm -1) bonds. The 1H NMR broad chemical shifts of 1 integrated for a total of 31 protons and are typical of Cu(II) complexes. ESR spectra of polycrystalline 1 at 77 and 300 K show axial spectra with areas in the ratio A77/ A300=4.02, suggesting a very weak Cu-Cu ferromagnetic interaction. Complex 1-doped with Zn(II) gives hfs with hyperfine interaction constant value A∥=112.45×10 -4 cm -1. The magnetization vs temperature data in the 2-299 K range, show that cupric ion pairs interact through a small antiferromagnetic Heisenberg exchange energy— JS1· S2 with a ground singlet state S=0, separated by J=-1.3 cm -1 from the excited triplet state S=1. The sign of the very weak interchange interaction constant, J, does not agree with the ESR spectra areas ratio of 1 at 77 and 300 K, which is a more accurate quantification of the weak ferromagnetic interaction Cu-Cu through the space.

  2. Pinned vorticity in rotating superfluids, with application to neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Pines, D.; Shaham, J. (Illinois Univ., Urbana (USA). Dept. of Physics); Alpar, M.A.; Anderson, P.W.


    The dynamic consequences of the existence of pinned vorticity in a rotating superfluid are studied by means of a simple model: the behavior of a rotating cylinder which contains a uniform region of either weakly or strongly pinned vorticity and which is being spun up or spun down by an external torque. It is shown that in the case of strong pinning, spin down can lead to periodic jumps (glitches) in the rotation frequency of the cylinder, followed by quasi-oscillatory relaxation, while in the case of weak pinning no glitches occur unless the cylinder is shaken so violently that vortices unpin. We conclude that the giant glitches and post-glitch behavior observed in the Vela pulsar may be explained by the sudden release of some 10% of the strongly pinned vortices in the neutron crust every few years as a result of pulsar spin down. We further suggest that the post-glitch behavior observed in the Crab pulsar can be explained if the macroglitches represent vorticity jumps induced by small starquakes in the weakly pinned vortex region expected in the crust of a young neutron star, and that the differences in ''glitch'' behavior of the Crab, Vela, and older pulsars may be explained on evolutionary grounds.

  3. Pinning Down versus Density


    Juhász, István; Soukup, Lajos; Szentmiklóssy, Zoltán


    The pinning down number $ {pd}(X)$ of a topological space $X$ is the smallest cardinal $\\kappa$ such that for any neighborhood assignment $U:X\\to \\tau_X$ there is a set $A\\in [X]^\\kappa$ with $A\\cap U(x)\

  4. Single crystal EPR study of the dinuclear Cu(II) complex [Cu(tda)(phen)](2)·H(2)tda (tda = thiodiacetate, phen = phenanthroline): influence of weak interdimeric magnetic interactions. (United States)

    Neuman, Nicolás I; Perec, Mireille; González, Pablo J; Passeggi, Mario C G; Rizzi, Alberto C; Brondino, Carlos D


    We report powder and single crystal EPR measurements of [Cu(tda)(phen)](2)·H(2)tda (tda = thiodiacetate, phen = phenanthroline) at 9.7 GHz. This compound consists of centrosymmetric copper(II) ion dimers, weakly ferromagnetically exchange-coupled (J = +3.2 cm(-1)), in which the dimeric units are linked by hydrophobic chemical paths involving the phen molecules. EPR revealed that the triplet spectra are collapsed by interdimeric exchange interactions mediated by that chemical path. Analysis and simulation of the single crystal EPR spectra were performed using Anderson's exchange narrowing model, together with statistical arguments. This approach allowed us to interpret the spectra modulated by the interdimeric interactions in situations of weak, intermediate, and strong exchange. We evaluated an interdimeric exchange constant J' = 0.0070(3) cm(-1), indicating that hydrophobic paths can transmit weak exchange interactions between centers at relatively long distances of the order of ∼10 Å.

  5. Spin effects in the weak interaction

    Energy Technology Data Exchange (ETDEWEB)

    Freedman, S.J. (Argonne National Lab., IL (USA) Chicago Univ., IL (USA). Dept. of Physics Chicago Univ., IL (USA). Enrico Fermi Inst.)


    Modern experiments investigating the beta decay of the neutron and light nuclei are still providing important constraints on the theory of the weak interaction. Beta decay experiments are yielding more precise values for allowed and induced weak coupling constants and putting constraints on possible extensions to the standard electroweak model. Here we emphasize the implications of recent experiments to pin down the strengths of the weak vector and axial vector couplings of the nucleon.

  6. Glitches and pinned vorticity in the Crab pulsar

    Energy Technology Data Exchange (ETDEWEB)

    Alpar, M.A. (Bogazici Univ., Istanbul, Turkey); Anderson, P.W.; Pines, D.; Shaham, J.


    It is suggested that the glitch behavior observed in the Crab pulsar is associated with vorticity jumps induced by a starquake or a comparable external fluctuation in the weakly pinned vortex region expected in the crust of a young neutron star, and that the differences in the glitch behavior of the Crab, Vela, and older pulsars may be explained on evolutionary grounds.

  7. Synthesis, crystal structure, weak antiferromagnetic behavior and electronic studies of novel [((-)-sparteine)(PhCO 2)(Cl)]Cu(II) complex (United States)

    Alcántara-Flores, José Luis; Vázquez-Bravo, José Jaime; Gutiérrez-Pérez, René; Ramírez-Rosales, Daniel; Bernès, Sylvain; Ramírez Bokhimi, José Guadalupe; Zamorano-Ulloa, Rafael; Reyes-Ortega, Yasmi


    [((-)-Sparteine)(PhCO 2)(Cl)]Cu(II) 1 complex is obtained by direct synthesis using copper(0). 1 crystallizes in the monoclinic space group P2 1 with a=14.7355(12), b=8.9768(5), c=17.2810(10) Å, β=111.916(5)°, and Z=4. The electronic spectrum of 1 shows a broad band with λ max˜841 nm(ɛ=0.261 mM-1 cm-6) characteristic of a low symmetry and tetragonally distorted square pyramidal local Cu geometry. The far IR spectrum of 1 shows characteristic vibrations of Cu-Cl (260, 267 cm -1), Cu-N (436, 467 cm -1) and Cu-O (457 cm -1) bonds. The 1H NMR spectrum of 1 is typical of magnetic Cu(II) complexes with line broadening due to efficient nuclear relaxation from the metal center. ESR spectra of polycrystalline 1 at 77 K show an axial spectrum with linewidth of 58.6 G and at 300 K of 89.0 G, with areas in the ratio A77/ A300=2.79, indicative of antiferromagnetic order. The linewidth is reduced by 34% on going from 300 to 77 K. Standard magnetization measurements at low temperatures show an Curie-Weiss behavior with θ=-21.67 K, suggesting a weak exchange coupling interaction. The crystalline structure of 1 shows that the lattice is arranged so that the space between molecules is smaller than 40 Å 3, not enough to accommodate solvent molecules. However, the shortest Cu-Cu contact is 7.5912(8) Å.

  8. Pinning, de-pinning and re-pinning of a slowly varying rivulet

    KAUST Repository

    Paterson, C.


    The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible de-pinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width. © 2013 Elsevier Masson SAS. All rights reserved.

  9. Synchronizability on complex networks via pinning control

    Indian Academy of Sciences (India)

    pinning strategies have different pinning synchronizability on the same complex network, and the synchronizability with pinning control is consistent with one without pinning control in various complex networks. Keywords. Complex network; the pinning synchronization; synchronizability. PACS Nos 05.45.Xt; 89.75.−k; 05.45.

  10. Evidence of pinning crossover and the role of twin boundaries in the peak effect in FeSeTe iron based superconductor (United States)

    Galluzzi, A.; Buchkov, K.; Tomov, V.; Nazarova, E.; Leo, A.; Grimaldi, G.; Nigro, A.; Pace, S.; Polichetti, M.


    The correlation between the appearance of a peak effect in the critical current of a superconducting material and the presence of twin boundaries, involved in a crossover between different pinning regimes, is investigated by means of dc magnetic measurements on a FeSe0.5Te0.5 crystal. In particular, by analyzing the temperature dependence of the critical current density J c(T) for different magnetic fields H, a crossover from a weak pinning regime to a strong pinning regime has been revealed. The analysis shows that this crossover can be ascribed to the presence of twin boundary defects inside the sample, and can be associated to the onset of the peak effect and interpreted as the start of the vortex dynamic processes responsible for the increase of J c with the field. On the basis of the information extracted by our analysis, a plausible dynamic scenario involving the contribution of the different pinning regimes depending on the applied field has been described, and the relative H(T) vortex phase diagram has been determined. Moreover, in our description, the peak in the J c(H) curve corresponds to the end of the processes leading to the peak effect and it is confirmed to be related to the transition from an elastic to a plastic deformation regime in the vortex lattice.

  11. Thermodynamics of Meissner effect and flux pinning behavior in the bulk of single-crystal La2-xSrxCuO4 ( x=0.09 )

    Energy Technology Data Exchange (ETDEWEB)

    Dhiman, I.; Ziesche, R.; Anand, V. K.; Riik, L.; Song, Gian; Islam, A. T. M. N.; Tanaka, Isao; Treimer, W.


    We have studied the magnetic flux pinning behavior and Meissner effect for the high-$T_{\\rm c}$ single crystal La$_{2-x}$Sr$_{x}$CuO$_{4}$ ($x$ = 0.09) superconductor using the polarized neutron imaging method with varying magnetic field and temperature. In the Meissner state expulsion of magnetic field (switched on during the measurements) is visualized, and the signatures of mixed state with increasing temperature are observed. While, for flux pinning behavior between 5 K $\\leq$ $T$ $\\leq$ 15 K and $H_{\\rm ext}$ = 63.5 mT (switched off during the measurements), the evolution of fringe pattern for both 0$^{o}$ and 90$^{o}$ sample orientation indicates magnetic flux pinning inside the bulk of the sample. At 25 K $\\leq$ $T$ $\\leq$ 32 K, a continuous decrease of inhomogeneously distribution pinned magnetic flux is observed, with the sample reaching a normal conducting state at $T_{\\rm c}$ ($\\approx$ 32 K). The flux pinning behavior is also explored as a function of $H_{\\rm ext}$, at $T$ = 5 K. As expected, with increasing $H_{\\rm ext}$ an increase in fringe density is observed, indicating an increase in magnetic flux pinning in the bulk of the sample. Therefore, in the present work for the first time we report bulk visualization of Meissner effect and flux pinning behavior in high-$T_{\\rm c}$ La$_{2-x}$Sr$_{x}$CuO$_{4}$ ($x$ = 0.09) superconductor. This study clearly demonstrates the potential of real space polarized neutron imaging technique for the visualization of the superconducting mixed state, particularly in the field of high-$T_{\\rm c}$ superconductors.

  12. Nondestrucive analysis of fuel pins (United States)

    Stepan, I.E.; Allard, N.P.; Suter, C.R.


    Disclosure is made of a method and a correspondingly adapted facility for the nondestructive analysis of the concentation of fuel and poison in a nuclear reactor fuel pin. The concentrations of fuel and poison in successive sections along the entire length of the fuel pin are determined by measuring the reactivity of a thermal reactor as each successive small section of the fuel pin is exposed to the neutron flux of the reactor core and comparing the measured reactivity with the reactivities measured for standard fuel pins having various known concentrations. Only a small section of the length of the fuel pin is exposed to the neutron flux at any one time while the remainder of the fuel pin is shielded from the neutron flux. In order to expose only a small section at any one time, a boron-10-lined dry traverse tube is passed through the test region within the core of a low-power thermal nuclear reactor which has a very high fuel sensitivity. A narrow window in the boron-10 lining is positioned at the core center line. The fuel pins are then systematically traversed through the tube past the narrow window such that successive small sections along the length of the fuel pin are exposed to the neutron flux which passes through the narrow window.

  13. Pinning Mechanisms in YBCO Tapes

    CERN Document Server

    Spera, Marcello; Ballarino, Amalia


    In this thesis work, a study on flux pinning mechanisms of commercial YBCO tapes is presented. This study has been performed via critical current characterization using transport (via direct I-V curves) and magnetization (via a Vibrating Sample Magnetometer) measurements. The latter ones turned out to be better concerning the comprehension of the pinning landscape of the provided samples, as a wider range of magnetic fields and temperatures is available for those measurements in the setup I used. The comparison of the experimental data with existing theoretical models allowed me to draw a picture of the pinning mechanisms underlying in each sample, and they turned out to be quite different one another. Moreover, for high-performance research tapes, another interesting feature has been found: the counterplay between the self-field critical current and the in-field one. Very well engineered artificial pinning structures limit the self-field critical current density due to the hi...

  14. Magnetic memory effects in triglycine sulfate ferroelectric crystals (United States)

    Gainutdinov, R. V.; Ivanova, E. S.; Petrzhik, E. A.; Lashkova, A. K.; Volk, T. R.


    The effect of a magnetic field on the processes of relaxation of the defect structure relaxation in a triglycine sulfate (TGS) ferroelectric (nonmagnetic) crystal has been observed for the first time. The atomic-force microscopy study has shown that the application of a static weak magnetic field (2 T, 20 min) significantly changes the size distribution of defect nanoclusters characteristic of TGS. Previously known macroscopic aftereffects of the magnetic field in TGS (slow relaxation of the dielectric susceptibility, symmetrization of P-E dielectric hysteresis loops, etc.) can be explained by the redistribution of pinning centers of domain walls caused by the magnetically induced reconfiguration of the defect structure.

  15. Interface roughening and pinning (United States)

    Roux, Stéphane; Hansen, Alex


    We study a simple model for thé pinning of an interface by impurities with random strengths, and thé depinning due to thé applied pressure, in a quasi-static propagation lirait. The model is very close to thé so called "Robin Hood" model introduced by Zaitsev. It is designed to describe e.g. thé invasion of a wetting fluid (imbibition) in a heterogeneous porous medium containing a second immiscible fluid. The relation between this model and other previously proposed approaches is discussed. The front of thé invaded domain is shown to develop a self-affine structure with an increase of thé roughness as a power-law of thé injected volume. The value of thé apparent roughness exponent can be favorably compared to some experimental measurements although we argue that thé true roughness exponent is out of reach of commonly used methods. We show that thé distribution f(d, Δ t) of distances d between discrete local invasions at a time interval Δ t can be described by a scaling law f(d, Δ t) = d^{-1}\\varphi(d/sqrt{Δ t}). This form can be obtained from thé identification of a hierarchical structure of "bursts" in thé pressure signal. Those "bursts" are quahtatively similar to those observed in quasistatic drainage, (i.e. invasion percolation), although characterized by différent scaling indices. Nous étudions un modèle simple pour analyser l'accrochage d'une interface sur des impuretés et le décrochage sous l'effet d'une pression appliquée, dans une limite quasi-statique. Ce modèle est très voisin du modèle "Robin Hood" introduit par Zaitsev. Il s'applique en particulier à l'invasion d'un fluide mouillant (imbibition) dans un milieu poreux hétérogène contenant un fluide immiscible. Nous discutons les relations entre ce modèle et d'autres approches proposées pour décrire ce phénomène. Le front d'invasion acquiert une structure auto-affine, avec un développement de la rugosité selon une loi de puissance du volume injecté. La valeur de l

  16. PinBus Interface Design

    Energy Technology Data Exchange (ETDEWEB)

    Hammerstrom, Donald J.; Adgerson, Jewel D.; Sastry, Chellury; Pratt, Richard M.; Pratt, Robert G.


    On behalf of the U.S. Department of Energy, PNNL has explored and expanded upon a simple control interface that might have merit for the inexpensive communication of smart grid operational objectives (demand response, for example) to small electric end-use devices and appliances. The approach relies on bi-directional communication via the electrical voltage states of from one to eight shared interconnection pins. The name PinBus has been suggested and adopted for the proposed interface protocol. The protocol is defined through the presentation of state diagrams and the pins’ functional definitions. Both simulations and laboratory demonstrations are being conducted to demonstrate the elegance and power of the suggested approach. PinBus supports a very high degree of interoperability across its interfaces, allowing innumerable pairings of devices and communication protocols and supporting the practice of practically any smart grid use case.

  17. Anomalous decrease in the creep rate of Zn doped YBCO single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Manzoor [Department of Electrical and Electronic Engineering, University Technology PETRONAS, 31750 Tronoh, Perak (Malaysia)], E-mail:; Takita, Koki [Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305 (Japan)


    The magnetic relaxation measurements were made using Zn doped YBCO single crystals YBa{sub 2}(Cu{sub 1-x}Zn{sub x}){sub 3}O{sub 7-{sigma}}. The decay of magnetization showed a linear dependence with the logarithm of time in wide temperature range of 0.1 < T/T{sub c} < 0.8, which indicates a strong flux pinning in these samples effective up to higher temperatures of 0.8T{sub c}. The temperature dependence of the normalized creep rate S(T) for applied fields of 1 T shows a non-monotonic behavior in the whole temperature range, with a peak at lower temperature and a dip at intermediate temperatures which is contrary to the predicted plateau in this region and indicates a strong change in the pinning mechanism of these samples at these temperatures and fields. The dip in creep rate S(T) of these samples up to 3% Zn concentration was found to be as large as 0.008, compared to 0.025-0.045 observed in the similar strong pinning systems. The weak temperature dependence of the pinning potential for these Zn doped samples at low temperatures shows drastic and systematic changes in U{sub 0} at higher temperatures which indicates that the Zn impurity contributes effectively to modify the pinning properties up to higher temperatures.

  18. New aspects of weak CH⋯π bonds: intermolecular interactions between alicyclic and aromatic rings in crystals of small compounds, peptides and proteins (United States)

    Ciunik, Z.; Berski, S.; Latajka, Z.; Leszczyński, J.


    The geometry of intermolecular contacts between alicyclic and aromatic rings in a number of crystal structures suggests an attractive interaction between the rings. An analysis of molecular packing of 444 different crystal structures collected in the Cambridge Structural Database shows that phenyl…cyclohexanonyl, cyclohexyl, and/or cyclopentyl ring interactions occur in 59-82% of studied crystals. Similar interactions are observed between aromatic rings and heterocyclic pyrrolidine rings of proline in peptides and proteins. An analysis of data collected in the Brookhaven Protein Data Bank reveals that interactions between proline CH groups and aromatic rings of phenylalanine, tyrosine, and tryptophan as acceptors are frequently observed in proteins. Based on these results, several geometric models of these interactions are proposed. Two of these models are fully optimized using quantum chemical calculations at the density functional theory level. Calculated energies suggest that the most important interaction between the cyclohexanone and benzene rings is described by the face-to-face model, in which three axial hydrogen atoms are directed toward the aromatic partner.

  19. Weak relativity

    CERN Document Server

    Selleri, Franco


    Weak Relativity is an equivalent theory to Special Relativity according to Reichenbach’s definition, where the parameter epsilon equals to 0. It formulates a Neo-Lorentzian approach by replacing the Lorentz transformations with a new set named “Inertial Transformations”, thus explaining the Sagnac effect, the twin paradox and the trip from the future to the past in an easy and elegant way. The cosmic microwave background is suggested as a possible privileged reference system. Most importantly, being a theory based on experimental proofs, rather than mutual consensus, it offers a physical description of reality independent of the human observation.

  20. Pin site metastasis of meningioma. (United States)

    Ozer, Ercan; Kalemci, Orhan; Acar, Umit Dursun; Canda, Serafettin


    Metastasis of meningiomas due to iatrogenic implantation of tumour cells is extremely rare and only four cases have been reported to date. In this study, we report a 45-year-old female patient who presented with meningioma metastasis at the pin site of head holder applied in the original operation.

  1. Fluxon Pinning in Niobium Films

    CERN Document Server

    Calatroni, Sergio; Darriulat, Pierre; Peck, M A; Valente, A M


    Resistive losses induced by the presence of trapped magnetic flux in niobium superconducting films have been studied using 1.5 GHz microwaves. They are measured to span a very broad spectrum depending on the film-substrate interface and on the gas used in the sputtering discharge. An interpretation in terms of pinning by noble gas clusters is considered.

  2. Pin-pin resonance as a reference in determining ballasted railway track vibration behaviour

    NARCIS (Netherlands)

    De Man, A.P.


    Pin-pin resonance is one of the most significant preferred vibration modes of beams, which are supported at equal distances, such as rails at sleepers in railway track structures do. Pin-pin resonance is a vibration that appears in one basic (first) mode and several higher modes, however the basic

  3. Evidence for small-molecule-mediated loop stabilization in the structure of the isolated Pin1 WW domain

    Energy Technology Data Exchange (ETDEWEB)

    Mortenson, David E.; Kreitler, Dale F.; Yun, Hyun Gi; Gellman, Samuel H., E-mail:; Forest, Katrina T., E-mail: [University of Wisconsin-Madison, Madison, WI 53706 (United States)


    Two structures of a small protein with a defined tertiary fold, the isolated Pin1 WW domain, have been determined via racemic crystallization with small-molecule additives. These additives, which are either racemic or achiral, appear to stabilize a dynamic loop region of the structure. The human Pin1 WW domain is a small autonomously folding protein that has been useful as a model system for biophysical studies of β-sheet folding. This domain has resisted previous attempts at crystallization for X-ray diffraction studies, perhaps because of intrinsic conformational flexibility that interferes with the formation of a crystal lattice. Here, the crystal structure of the human Pin1 WW domain has been obtained via racemic crystallization in the presence of small-molecule additives. Both enantiomers of a 36-residue variant of the Pin1 WW domain were synthesized chemically, and the l- and d-polypeptides were combined to afford diffracting crystals. The structural data revealed packing interactions of small carboxylic acids, either achiral citrate or a d,l mixture of malic acid, with a mobile loop region of the WW-domain fold. These interactions with solution additives may explain our success in crystallization of this protein racemate. Molecular-dynamics simulations starting from the structure of the Pin1 WW domain suggest that the crystal structure closely resembles the conformation of this domain in solution. The structural data presented here should provide a basis for further studies of this important model system.

  4. Nonlinear polarization dynamics in a weakly birefringent all-normal dispersion photonic crystal fiber: toward a practical coherent fiber supercontinuum laser. (United States)

    Tu, Haohua; Liu, Yuan; Liu, Xiaomin; Turchinovich, Dmitry; Lægsgaard, Jesper; Boppart, Stephen A


    Dispersion-flattened dispersion-decreased all-normal dispersion (DFDD-ANDi) photonic crystal fibers have been identified as promising candidates for high-spectral-power coherent supercontinuum (SC) generation. However, the effects of the unintentional birefringence of the fibers on the SC generation have been ignored. This birefringence is widely present in nonlinear non-polarization maintaining fibers with a typical core size of 2 µm, presumably due to the structural symmetry breaks introduced in the fiber drawing process. We find that an intrinsic form-birefringence on the order of 10(-5) profoundly affects the SC generation in a DFDD-ANDi photonic crystal fiber. Conventional simulations based on the scalar generalized nonlinear Schrödinger equation (GNLSE) fail to reproduce the prominent observed features of the SC generation in a short piece (9-cm) of this fiber. However, these features can be qualitatively or semi-quantitatively understood by the coupled GNLSE that takes into account the form-birefringence. The nonlinear polarization effects induced by the birefringence significantly distort the otherwise simple spectrotemporal field of the SC pulses. We therefore propose the fabrication of polarization-maintaining DFDD-ANDi fibers to avoid these adverse effects in pursuing a practical coherent fiber SC laser.

  5. A prospective comparative study of pin site infection in pediatric supracondylar humeral fractures: daily pin care vs. no pin care. (United States)

    Kao, Hsuan-Kai; Chen, Mei-Chuan; Lee, Wei-Chun; Yang, Wen-E; Chang, Chia-Hsieh


    Pin site infection is a critical issue for patients' safety in skeletal fixation using percutaneous pins or wires. Closed reduction and percutaneous Kirschner wires fixation are the mainstay of treatment in pediatric supracondylar humeral fractures. Little information is available in the literature about the optimal regimen of pin site care in children. We performed a prospective comparative study of 61 children with supracondylar humeral fractures between June 2011 and March 2013 after approval by the institutional review board. They were allocated into two groups of different postoperative pin site care methods by the emergency department arrival date and received fracture fixation within 24 h. Postoperatively, 30 children underwent pin site cleaning every day whereas the other 31 patients did not have the pin sites cleaned until the pins removal 4-6 weeks later. Demographic data were not significantly different between the two groups. The infection rate was significantly higher in patients who underwent daily pin site care (90.3 vs. 53.3 %, p = 0.001). Of the 144 pin sites, infection occurred at 42 (57.5 %) pin sites in the daily care group and at 19 (26.8 %) pin sites in the non-care group. The number of telephone consultations for postoperative care was significantly higher in the daily care group (1.0 vs. 0.27 call/case, p = 0.007). Daily pin site care was associated with a higher infection rate and greater stress in postoperative care that required more telephone consultations. The study results could not support daily pin site care. Careful observation of pin sites was recommended in the treatment of pediatric supracondylar humeral fractures.

  6. Muscle Weakness

    Directory of Open Access Journals (Sweden)

    Ali Al Kaissi MD, MSc


    Full Text Available Marked ligamentous hyperlaxity and muscle weakness/wasting associated with awkward gait are the main deficits confused with the diagnosis of myopathy. Seven children (6 boys and 1 girl with an average age of 8 years were referred to our department because of diverse forms of skeletal abnormalities. No definitive diagnosis was made, and all underwent a series of sophisticated investigations in other institutes in favor of myopathy. We applied our methodology through the clinical and radiographic phenotypes followed by targeted genotypic confirmation. Three children (2 boys and 1 girl were compatible with the diagnosis of progressive pseudorheumatoid chondrodysplasia. The genetic mutation was correlated with the WISP 3 gene actively expressed by articular chondrocytes and located on chromosome 6. Klinefelter syndrome was the diagnosis in 2 boys. Karyotyping confirmed 47,XXY (aneuploidy of Klinefelter syndrome. And 2 boys were finally diagnosed with Morquio syndrome (MPS type IV A as both showed missense mutations in the N-acetylgalactosamine-sulfate sulfatase gene. Misdiagnosis can lead to the initiation of a long list of sophisticated investigations.

  7. The continuum disordered pinning model. (United States)

    Caravenna, Francesco; Sun, Rongfeng; Zygouras, Nikos

    Any renewal processes on [Formula: see text] with a polynomial tail, with exponent [Formula: see text], has a non-trivial scaling limit, known as the [Formula: see text]-stable regenerative set. In this paper we consider Gibbs transformations of such renewal processes in an i.i.d. random environment, called disordered pinning models. We show that for [Formula: see text] these models have a universal scaling limit, which we call the continuum disordered pinning model (CDPM). This is a random closed subset of [Formula: see text] in a white noise random environment, with subtle features:Any fixed a.s. property of the [Formula: see text]-stable regenerative set (e.g., its Hausdorff dimension) is also an a.s. property of the CDPM, for almost every realization of the environment.Nonetheless, the law of the CDPM is singular with respect to the law of the [Formula: see text]-stable regenerative set, for almost every realization of the environment. The existence of a disordered continuum model, such as the CDPM, is a manifestation of disorder relevance for pinning models with [Formula: see text].

  8. Investigation of the bulk pinning force in YBCO superconducting films with nano-engineered pinning centres

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, A., E-mail: [School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom); National Institute of Materials Physics, Bucharest 077125 (Romania); Dang, V.S.; Yearwood, G.; Mikheenko, P. [School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom); Huhtinen, H.; Paturi, P. [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, Turku FI-20014 (Finland)


    Highlights: • Pinning centres in YBCO films increase critical current density and pinning force. • Normalised pinning force vs. reduced field give information on their nature. • Dew-Hughes model was used to analyse various nanostructured YBCO films. • Main pinning mechanism is normal surface pinning. - Abstract: For practical applications of superconducting materials in applied magnetic fields, artificial pinning centres in addition to natural ones are required to oppose the Lorentz force. These pinning centres are actually various types of defects in the superconductor matrix. The pinning centres can be categorised on their dimension (volume, surface, or point) and on their character (normal cores or Δκ cores). We have used the Dew Hughes approach to determine the types of pinning centres present in various samples, with various thicknesses, temperatures and nanostructured additions to the superconducting matrix. Results show that normal surface pinning centres are present throughout almost all the samples, as dominant pinning mechanism. Such 2D extended pinning centres are mainly due to dislocations, grain boundaries, nanorods. Strong normal point pinning centres were found to be common in BZO doped YBCO samples. Other types of pinning centres, in various (minor) concentrations were also found in some of the samples.

  9. Thermal treatment of YBa2Cu3-xALxO6+#delta# single crystals in different atmospheres and neutron-diffraction study of excess oxygen pinned by the Al

    DEFF Research Database (Denmark)

    Brecht, E.; Schmahl, W.W.; Miehe, G.


    .19. Crystals annealed in reducing atmospheres at temperatures above 973 K develop orthorhombic long-range order after reoxidation at 673 K, probably due to short-range clustering of the AlOn defects. The obtained orthorhombicity of the reoxidized material decreases with decreasing temperature of the reduction...... treatment, No change in the structural state is obtained when the reducing treatment is performed below 950 K; the reoxidized samples remain macroscopically tetragonal. Annealing the samples at 1073 K in oxygen restores the tweed structure. An evolution of the tweed structure with annealing time towards...


    NARCIS (Netherlands)



    The morphology of incommensurately modulated crystals is considered. A surface free energy model is constructed which interprets the stabilization of the incommensurate facets as due to surface pinning of the phase of the modulation wave. The stepped nature of the true crystal surface restricts the

  11. Spectroscopic amplifier for pin diode; Amplificador espectroscopico para diodo Pin

    Energy Technology Data Exchange (ETDEWEB)

    Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R., E-mail: [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)


    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  12. Vortex Matching and Domain Structure in Large Arrays of Artificial Pinning Centers (United States)

    Field, S. B.; James, S.; Barentine, J.; Metlushko, V.; Welp, U.; Crabtree, G.; Shtrikman, H.


    We have used high-resolution scanning Hall probe microscopy to obtain spatial information about vortex configurations in very large periodic arrays of artificial pinning sites. Very clear matching effects are seen at matching fields where there are one or two vortices per pinning site. At the third matching field, however, no matching effects are seen. Instead, there is a very disordered vortex configuration presumably due to weakly-pinned interstitials. Further, matching effects have been observed at several non-integral multiples of the matching field, including 1/4, 1/2, 3/4 and 3/2. There is a clear domain structure visible at many of these non-integral matching fields, with striking domain wall boundaries. Finally, at integral matching fields we observe a weak modulation in the flux density which may be related to an possible positional instability.

  13. Pinning of holographic sliding stripes (United States)

    Jokela, Niko; Järvinen, Matti; Lippert, Matthew


    In a holographic probe-brane model exhibiting a spontaneously spatially modulated ground state, we introduce explicit sources of symmetry breaking in the form of ionic and antiferromagnetic lattices. For the first time in a holographic model, we demonstrate pinning, in which the translational Goldstone mode is lifted by the introduction of explicit sources of translational symmetry breaking. The numerically computed optical conductivity fits very well to a Drude-Lorentz model with a small residual metallicity, precisely matching analytic formulas for the DC conductivity. We also find an instability of the striped phase in the presence of a large-amplitude ionic lattice.

  14. PIN1 gene variants in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Siedlecki Janusz


    Full Text Available Abstract Background Peptidyl-prolyl isomerase, NIMA-interacting 1 (PIN1 plays a significant role in the brain and is implicated in numerous cellular processes related to Alzheimer's disease (AD and other neurodegenerative conditions. There are confounding results concerning PIN1 activity in AD brains. Also PIN1 genetic variation was inconsistently associated with AD risk. Methods We performed analysis of coding and promoter regions of PIN1 in early- and late-onset AD and frontotemporal dementia (FTD patients in comparison with healthy controls. Results Analysis of eighteen PIN1 common polymorphisms and their haplotypes in EOAD, LOAD and FTD individuals in comparison with the control group did not reveal their contribution to disease risk. In six unrelated familial AD patients four novel PIN1 sequence variants were detected. c.58+64C>T substitution that was identified in three patients, was located in an alternative exon. In silico analysis suggested that this variant highly increases a potential affinity for a splicing factor and introduces two intronic splicing enhancers. In the peripheral leukocytes of one living patient carrying the variant, a 2.82 fold decrease in PIN1 expression was observed. Conclusion Our data does not support the role of PIN1 common polymorphisms as AD risk factor. However, we suggest that the identified rare sequence variants could be directly connected with AD pathology, influencing PIN1 splicing and/or expression.

  15. Pinning of fermionic occupation numbers. (United States)

    Schilling, Christian; Gross, David; Christandl, Matthias


    The Pauli exclusion principle is a constraint on the natural occupation numbers of fermionic states. It has been suspected since at least the 1970s, and only proved very recently, that there is a multitude of further constraints on these numbers, generalizing the Pauli principle. Here, we provide the first analytic analysis of the physical relevance of these constraints. We compute the natural occupation numbers for the ground states of a family of interacting fermions in a harmonic potential. Intriguingly, we find that the occupation numbers are almost, but not exactly, pinned to the boundary of the allowed region (quasipinned). The result suggests that the physics behind the phenomenon is richer than previously appreciated. In particular, it shows that for some models, the generalized Pauli constraints play a role for the ground state, even though they do not limit the ground-state energy. Our findings suggest a generalization of the Hartree-Fock approximation.

  16. Evidence for small-molecule-mediated loop stabilization in the structure of the isolated Pin1 WW domain. (United States)

    Mortenson, David E; Kreitler, Dale F; Yun, Hyun Gi; Gellman, Samuel H; Forest, Katrina T


    The human Pin1 WW domain is a small autonomously folding protein that has been useful as a model system for biophysical studies of β-sheet folding. This domain has resisted previous attempts at crystallization for X-ray diffraction studies, perhaps because of intrinsic conformational flexibility that interferes with the formation of a crystal lattice. Here, the crystal structure of the human Pin1 WW domain has been obtained via racemic crystallization in the presence of small-molecule additives. Both enantiomers of a 36-residue variant of the Pin1 WW domain were synthesized chemically, and the L- and D-polypeptides were combined to afford diffracting crystals. The structural data revealed packing interactions of small carboxylic acids, either achiral citrate or a D,L mixture of malic acid, with a mobile loop region of the WW-domain fold. These interactions with solution additives may explain our success in crystallization of this protein racemate. Molecular-dynamics simulations starting from the structure of the Pin1 WW domain suggest that the crystal structure closely resembles the conformation of this domain in solution. The structural data presented here should provide a basis for further studies of this important model system.

  17. Pattern Reconfigurable Patch Antenna menggunakan Edge Shorting Pin dan Symmetrical Control Pin

    Directory of Open Access Journals (Sweden)



    Full Text Available Abstrak Metode baru dalam mendesain suatu pattern reconfigurable antenna telah diteliti. Penelitian ini fokus pada optimasi antena patch lingkaran single layer pencatuan probe koaksial dengan mengintegrasikan 24 switch/shorting pin pada sisi patch yang disebut edge shorting pin dan 8 shorting pin membentuk lingkaran dengan radius tertentu dan selanjutnya disebut symmetrical control pin yang fungsinya sebagai metode penyepadan impedansi. Algoritma Genetika yang dikombinasikan dengan Finite Element Software digunakan untuk mengoptimasi kombinasi  switch, radius lingkaran symmetrical control pin, dan radius patch untuk mendapatkan kemampuan pattern reconfigurability. Antena ini menghasilkan 8 kemungkinan arah radiasi azzimuth dengan resolusi 45o dan arah elevasi 30o pada frekuensi 2,4 Ghz. Optimasi, simulasi, fabrikasi, dan pengukuran dilakukan untuk memverifikasi hasil penelitian. Kata kunci: Patch Lingkaran, Edge Shorting Pin, Symmetrical Control Pin, Algoritma Genetika, Pattern Reconfigurable   Abstract New method for desaining pattern reconfigurable antenna was studied. This study focuses on the optimization of a single layer circular patch antenna with probe feed by integrating the 24 switch / shorting pin on the side of the patch that called Edge Shorting Pins and 8 shorting pins form circular line in such radius that called Symmetrical Control Pins as a impedance matching method. Genetic algorithm combined with the Finite Element Software is used to optimize the switch combination, the radius of circular line of symmetrical control pins, and the patch radius to obtain a pattern reconfigurability capabilities. This antenna produces 8 possible directions of azimuth radiation with a resolution of 45o and 30o elevation direction at a frequency of 2.4 GHz. Optimization, simulation, fabrication, and measurement was done to verify the results. Keywords: Circular Patch, Edge Shorting Pin, Symmetrical Control Pin, Genetic Algorithm, Pattern

  18. Pinning Loss Power Density in Superconductors (United States)

    Matsushita, Teruo


    The pinning loss power density is theoretically derived based on the resistive energy dissipation when the flux lines are driven by the Lorentz force in a superconductor. The obtained loss power density does not depend on the viscosity or flow resistivity, but is proportional to the pinning force density only, and it possesses the nature of hysteresis loss, as commonly measured in experiments. These features are predicted by the critical state model, which was recently proved theoretically. The obtained pinning force density is consistent with the prediction of the coherent potential approximation theory, a kind of statistical summation theory, for flux pinning. Thus, the irreversible properties associated with the flux pinning can be comprehensively described by these flux pinning theories. The irreversible flux pinning in the superconductor is compared with similar irreversible phenomena such as the motion of magnetic domain walls in ferromagnetic materials and the friction in mechanical systems. The possibility is also discussed for a general theoretical description of these irreversible phenomena in which the hysteresis loss occurs.

  19. Electroanalytical devices with pins and thread. (United States)

    Glavan, Ana C; Ainla, Alar; Hamedi, Mahiar M; Fernández-Abedul, M Teresa; Whitesides, George M


    This work describes the adaptive use of conventional stainless steel pins-used in unmodified form or coated with carbon paste-as working, counter, and quasi-reference electrodes in electrochemical devices fabricated using cotton thread or embossed omniphobic R(F) paper to contain the electrolyte and sample. For some applications, these pin electrodes may be easier to modify and use than printed electrodes, and their position and orientation can be changed as needed. Electroanalytical devices capable of multiplex analysis (thread-based arrays or 96-well plates) were easily fabricated using pins as electrodes in either thread or omniphobic R(F) paper.

  20. Vortex dynamics in supraconductors in the presence of anisotropic pinning

    Energy Technology Data Exchange (ETDEWEB)

    Soroka, O.K.


    Vortex dynamics in two different classes of superconductors with anisotropic unidirected pinning sites was experimentally investigated by magnetoresistivity measurements: YBCO-films with unidirected twins and Nb-films deposited on faceted Al{sub 2}O{sub 3} substrate surfaces. For the interpretation of the experimental results a theoretical model based on the Fokker-Planck equation was used. It was proved by X-ray measurements that YBCO films prepared on (001) NdGaO{sub 3} substrates exhibit only one twin orientation in contrast to YBCO films grown on (100) SrTiO{sub 3} substrates. The magnetoresistivity measurements of the YBCO films with unidirected twin boundaries revealed the existence of two new magnetoresistivity components, which is a characteristic feature of a guided vortex motion: an odd longitudinal component with respect to the magnetic field sign reversal and an even transversal component. However, due to the small coherence length in YBCO and the higher density of point-like defects comparing to high-quality YBCO single crystals, the strength of the isotropic point pinning was comparable with the strength of the pinning produced by twins. This smeared out all e ects caused by the pinning anisotropy. The behaviour of the odd longitudinal component was found to be independent of the transport current direction with respect to the twin planes. The magnetoresistivity measurements of faceted Nb films demonstrated the appearance of an odd longitudinal and even transversal component of the magnetoresistivity. The temperature and magnetic field dependences of all relevant magnetoresistivity components were measured. The angles between the average vortex velocity vector and the transport current direction calculated from the experimental data for the different transport current orientations with respect to the facet ridges showed that the vortices moved indeed along the facet ridges. An anomalous Hall effect, i.e. a sign change of the odd transversal

  1. Pinning Synchronization of Switched Complex Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Liming Du


    Full Text Available Network topology and node dynamics play a key role in forming synchronization of complex networks. Unfortunately there is no effective synchronization criterion for pinning synchronization of complex dynamical networks with switching topology. In this paper, pinning synchronization of complex dynamical networks with switching topology is studied. Two basic problems are considered: one is pinning synchronization of switched complex networks under arbitrary switching; the other is pinning synchronization of switched complex networks by design of switching when synchronization cannot achieved by using any individual connection topology alone. For the two problems, common Lyapunov function method and single Lyapunov function method are used respectively, some global synchronization criteria are proposed and the designed switching law is given. Finally, simulation results verify the validity of the results.

  2. Nucleophosmin Interacts with PIN2/TERF1-interacting Telomerase Inhibitor 1 (PinX1) and Attenuates the PinX1 Inhibition on Telomerase Activity. (United States)

    Cheung, Derek Hang-Cheong; Ho, Sai-Tim; Lau, Kwok-Fai; Jin, Rui; Wang, Ya-Nan; Kung, Hsiang-Fu; Huang, Jun-Jian; Shaw, Pang-Chui


    Telomerase activation and telomere maintenance are critical for cellular immortalization and transformation. PIN2/TERF1-interacting telomerase inhibitor 1 (PinX1) is a telomerase regulator and the aberrant expression of PinX1 causes telomere shortening. Identifying PinX1-interacting proteins is important for understanding telomere maintenance. We found that PinX1 directly interacts with nucleophosmin (NPM), a protein that has been shown to positively correlate with telomerase activity. We further showed that PinX1 acts as a linker in the association between NPM and hTERT, the catalytic subunit of telomerase. Additionally, the recruitment of NPM by PinX1 to the telomerase complex could partially attenuate the PinX1-mediated inhibition on telomerase activity. Taken together, our data reveal a novel mechanism that regulates telomerase activation through the interaction between NPM, PinX1 and the telomerase complex.

  3. Effects of contact line hysteresis and surface tension on contact line pinning of inclined droplets. (United States)

    Berejnov, Viatcheslav; Thorne, Robert E.


    The stability and pinning of drops on inclined surfaces is of fundamental and technological interest. Contact line dynamics depends on the properties of the liquid, the solid surface and the manner in which line motion is driven. Achieving reproducible final contact line and drop shapes is important in biotechnology applications where drops are used as mini-reactors, such as in structural genomics where sessile drops are used for protein and virus crystallization. We will describe experiments investigating pinning and deformation of drops containing pure liquids, proteins and colloids, placed on substrates with a range of surface treatments. Proteins affect contact angle hysteresis at low concentrations, and surface tension at high concentration, leading to two different regimes of pinning. Theoretical approaches that can be useful in understanding our results will also be presented.

  4. IMp: The customizable LEGO® Pinned Insect Manipulator

    Directory of Open Access Journals (Sweden)

    Steen Dupont


    Full Text Available We present a pinned insect manipulator (IMp constructed of LEGO® building bricks with two axes of movement and two axes of rotation. In addition we present three variants of the IMp to emphasise the modular design, which facilitates resizing to meet the full range of pinned insect specimens, is fully customizable, collapsible, affordable and does not require specialist tools or knowledge to assemble.

  5. LOFT DTT rake pin stress analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mosby, W.R.


    A stress analysis of the 3/8-inch and 1/4-inch pins which hold the rake assembly to the flange was performed and shows stresses to be lower than the Class 1 allowables of the ASME Boiler and Pressure Vessel Code. The alternating pin stresses were found to be below the endurance limit and fatigue failure will not occur. The rake assembly was assumed to be loaded by steady drag and lift forces and alternating vortex shedding forces.

  6. Artificial pinning in thick YBCO films: Pinning potential and c-axis correlation

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, Adrian, E-mail: [School of Metallurgy and Materials, University of Birmingham, B15 2TT Birmingham (United Kingdom); National Institute of Materials Physics, Bucharest 077125 (Romania); Mikheenko, Pavlo; Sarkar, Asis; Dang, Van Son; Awang Kechik, Mohammed M.; Abell, John S. [School of Metallurgy and Materials, University of Birmingham, B15 2TT Birmingham (United Kingdom); Paturi, Petriina; Huhtinen, Hannu [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 (Finland)


    We have introduced artificial pinning centres in thick (>1 {mu}m) YBCO films grown by Pulsed Laser Deposition using substrate decoration, quasi-multilayers, and target doping approaches. We have found that the frequency dependence of critical current density is consistent with a logarithmic dependence of pinning potential on current density. For most of materials used as nano-dots, artificially-induced pinning centres have a larger potential than natural ones. From angle-dependent in-field transport measurements and from Transmission Electron Microscopy we have found evidence of c-axis correlated pinning centres.

  7. Glassy dynamics in randomly pinned particle systems (United States)

    Phan, Anh; Schweizer, Kenneth

    We generalize the force-level, microscopic Elastically Collective Nonlinear Langevin Equation theory of activated relaxation in bulk hard sphere and thermal liquids to address the role of internal quenched disorder. So-called neutral confinement is considered where a subset of particles are randomly pinned and there is no change of equilibrium pair structure. As the pinned fraction grows, the cage scale dynamical constraints are intensified, resulting in the mobile particles becoming more localized, a larger glassy shear modulus, and an enhanced cage scale barrier. However, based on an approximate analysis of how quenched disorder modifies collective elastic field fluctuations, random pinning is predicted to effectively screen or localize the strain field associated with the longer range elastic component of the activation barrier, leading to an overall reduction of it with pinning fraction. The different response of the cage and elastic barriers to quenched disorder results in subtle predictions for how the alpha relaxation time varies with pinning fraction and system volume fraction. A semi-quantitative comparison with recent simulations of a pinned-mobile water model are consistent with the theory. Predictions are made for thermal molecular liquids.

  8. Strong pinning regimes explored with large-scale Ginzburg-Landau simulations (United States)

    Willa, Roland; Koshelev, Alexei E.

    Improving the current-carrying capability of superconductors requires a deep understanding of vortex pinning. Within the theory of (3D) strong pinning an ideal vortex lattice is weakly deformed by a low density np of strong defects. In this limit the critical current jc is expected to grow linearly with np and to decrease with the field B according to B-α with α 0 . 5 . In the small-field limit the (1D) strong pinning theory of isolated vortices predicts jc np0 . 5 , independent of B. We explore strong pinning by low defect densities using time-dependent Ginzburg-Landau simulations. Our numerical results suggest the existence of a wide regime, where the lattice order is destroyed and yet interactions between vortices are important. In particular, for large defects we found an extended range of power-law decay of jc (B) with α 0 . 3 , smaller than predicted. This regime requires the development of new analytical models. Exploring the behavior of jc for various defect densities and sizes, we will establish pinning regimes and applicability limits of the conventional theory. This work is supported by the U.S. Department of Energy, Office of Science, Materials Sciences and Engineering Division. R. W. acknowledges support from the Swiss National Science Foundation through the SNSF Early Postdoc Mobility Fellowship.

  9. Performance comparison of pin fin in-duct flow arrays with various pin cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Sahiti, N. [LSTM-Erlangen, Institute of Fluid Mechanics, Friedrich-Alexander-University, Erlangen-Nuremberg, Cauerstr. 4, D-91058 Erlangen (Germany)]. E-mail:; Lemouedda, A. [Department of Process Engineering, Georg-Simon-Ohm University of Applied Sciences, Wassertorstr. 10, D-90489 Nuremberg (Germany); Stojkovic, D. [LSTM-Erlangen, Institute of Fluid Mechanics, Friedrich-Alexander-University, Erlangen-Nuremberg, Cauerstr. 4, D-91058 Erlangen (Germany); Durst, F. [LSTM-Erlangen, Institute of Fluid Mechanics, Friedrich-Alexander-University, Erlangen-Nuremberg, Cauerstr. 4, D-91058 Erlangen (Germany); Franz, E. [Department of Process Engineering, Georg-Simon-Ohm University of Applied Sciences, Wassertorstr. 10, D-90489 Nuremberg (Germany)


    Pin fin arrays are frequently used for cooling of high thermal loaded electronic components. Whereas the pin fin accomplishment regarding heat transfer is always higher than that of other fin configurations, the high pressure drop accompanying pins seriously reduces their overall performance. In order to check how the form of pin cross-section influences the pressure drop and heat transfer capabilities, six forms of pin cross-section were numerically investigated. By employing the conjugate heat transfer boundary conditions, numerical simulations close to realistic working conditions were performed. Two geometric comparison criteria were applied so that the conclusions derived from numerical computations were valid for various possible geometric parameters and working conditions. Both staggered and inline pin arrangements were investigated as these are common in practical applications. The heat transfer and pressure drop characteristics are presented in terms of appropriate dimensionless variables. The final judgment of the performance of the pin fin cross-section was performed based on the heat exchanger performance plot. Such a plot allows the assessment of the pin performance including their heat transfer and the pressure drop.

  10. Theoretical Probing of Weak Anion-Cation Interactions in Certain Pyridinium based Ionic Liquid Ion-Pairs and the Application of Molecular Electrostatic Potential in their Ionic Crystal Density Determination : A Comparative Study Using Density Functional Approach. (United States)

    Joseph, Aswathy; Thomas, Vibin Ipe; Żyła, Gaweł; Alapat, Padmanabhan Sridharan; Mathew, Suresh


    A comprehensive study on the structure, nature of interaction and properties of six ionic pairs of 1-butylpyridinium and 1-butyl-4-methylpyridinium cations in combination with tetrafluoroborate (BF4-), chloride (Cl-) and bromide (Br-) anions have been carried out using Density Functional Theory (DFT). The anion-cation interaction energy (ΔEint), theoretical band gap, molecular orbital energy-order, DFT-based chemical activity descriptors: chemical potential (μ), chemical hardness (η) and electrophilicity index (ω) and distribution of density of states (DOS) of these ion-pairs were investigated. The ascendancy of -CH3 substituent at the 4th position of the 1-butylpyridinium cation ring on the values of ΔEint, theoretical band gap and chemical activity descriptors was evaluated. The ΔEint values were negative for all the six ion-pairs and were highest for Cl- containing ion-pairs. The theoretical band-gap value after -CH3 substitution increased from 3.78 to 3.96 eV (for Cl-) and from 2.74 to 2.88 eV (for Br-) and decreased from 4.9 to 4.89 eV (for BF4-). Ion-pairs of BF4- were more susceptible to charge transfer processes as inferred from their significantly high η values and comparatively small difference in ω value after -CH3 substitution. The change in η and μ values due to the -CH3 substituent is negligibly small in all cases except for the ion-pairs of Cl-. The entropy change (ΔS) was negative for all the ion-pairs. Critical point (CP) analysis were carried out to investigate the AIM topological parameters at the inter-ionic bond critical points (BCPs). The RDG isosurface analysis indicated that anion-cation interaction was dominated by strong Hcat….Xani and Ccat….Xani interactions in ion-pairs of Cl- and Br- whereas weak van der Waal's effect dominated in ion-pairs of BF4-. The molecular electrostatic potential (MESP) based parameter ΔΔVmin measuring the anion-cation interaction strength showed a good linear correlation with ΔEint for all 1

  11. PINS Testing and Modification for Explosive Identification

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; A.J. Caffrey


    The INL's Portable Isotopic Neutron Spectroscopy System (PINS)1 non-intrusively identifies the chemical fill of munitions and sealed containers. PINS is used routinely by the U.S. Army, the Defense Threat Reduction Agency, and foreign military units to determine the contents of munitions and other containers suspected to contain explosives, smoke-generating chemicals, and chemical warfare agents such as mustard and nerve gas. The objects assayed with PINS range from softball-sized M139 chemical bomblets to 200 gallon DOT 500X ton containers. INL had previously examined2 the feasibility of using a similar system for the identification of explosives, and based on this proof-of-principle test, the development of a dedicated system for the identification of explosives in an improvised nuclear device appears entirely feasible. INL has been tasked by NNSA NA-42 Render Safe Research and Development with the development of such a system.

  12. Theory of Disorder (collective Pinning and Phase Transition) (United States)

    Larkin, Anatoly


    One weak force causes a weak distortion. The result of the action of many weak forces depends on a system: it may lead either to a weak or to a strong distortion. In the Abrikosov lattice of vortices in superconductors, the impurities (centers of pinning) are belonged to our laboratory system and do not move together with vortices. Therefore, the centers of pinning destroy the long-range order in the lattice. Short-range order exists only at the distance smaller than the correlation length L_c.[1] This results in appearance of a friction force, a critical current, a hysteresis. [2,3] In any business, it is important to have certain corner stones, meaning the results, which rise no doubts in their correctness. Such a corner stone for the physics of critical phenomena was provided by ONSAGER in 1944 by his exact solution of two dimensional Ising model. This paper stimulated a large number of theorists toward the study of critical phenomena. The methods of quantum field theory allowed to segregate the most divergent contributions of the perturbation theory: so called, parquet diagrams - and sum up these contributions. As the result, singularity close to phase transition in a real three dimensional system with dipole-dipole interaction was found exactly. [4] After obtaining the results, relevant to a real physical system, we completed this paper with two important appendices of a methodical character. In the first appendix we obtained the same result using the method of multiplicative renormalization group. This method is equivalent to that of parquet diagrams summation, but it is simpler and found later applications in different branches of condensed matter theory. In the second appendix we considered the effect of the symmetry of the order parameter on the singularity at the transition point in a non-physical four dimensional system. I am grateful to my co-authors Yu.N.Ovchinnikov and D.E.Khmelnitskii, my teachers A.D.Sakharov and A.B.Migdal. I should mention here

  13. Lattice deformations and plastic flow through bottlenecks in a two-dimensional model for flux pinning in type-II superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, H.J.; Brass, A.; Berlinsky, A.J.


    The deformations of a 2D vortex lattice pinned by a random potential are studied by a molecular-dynamics annealing method. All but very weak potentials produce a highly defective lattice, consisting of trapped lattice regions separated by channels in which the vortices flow plastically. It is argued that this type of deformation is the cause of the observed restricted applicability of collective pinning theory.

  14. Pinning, flux diodes and ratchets for vortices interacting with conformal pinning arrays (United States)

    Olson Reichhardt, C. J.; Wang, Y. L.; Xiao, Z. L.; Kwok, W. K.; Ray, D.; Reichhardt, C.; Jankó, B.


    A conformal pinning array can be created by conformally transforming a uniform triangular pinning lattice to produce a new structure in which the six-fold ordering of the original lattice is conserved but where there is a spatial gradient in the density of pinning sites. Here we examine several aspects of vortices interacting with conformal pinning arrays and how they can be used to create a flux flow diode effect for driving vortices in different directions across the arrays. Under the application of an ac drive, a pronounced vortex ratchet effect occurs where the vortices flow in the easy direction of the array asymmetry. When the ac drive is applied perpendicular to the asymmetry direction of the array, it is possible to realize a transverse vortex ratchet effect where there is a generation of a dc flow of vortices perpendicular to the ac drive due to the creation of a noise correlation ratchet by the plastic motion of the vortices. We also examine vortex transport in experiments and compare the pinning effectiveness of conformal arrays to uniform triangular pinning arrays. We find that a triangular array generally pins the vortices more effectively at the first matching field and below, while the conformal array is more effective at higher fields where interstitial vortex flow occurs.

  15. Pinning technique for shoulder fractures in adolescents: computer modelling of percutaneous pinning of proximal humeral fractures (United States)

    Mehin, Ramin; Mehin, Afshin; Wickham, David; Letts, Merv


    Background In the technique of percuatenous pinning of proximal humerus fractures, the appropriate entry site and trajectory of pins is unknown, especially in the adolescent population. We sought to determine the ideal entry site and trajectory of pins. Methods We used magnetic resonance images of nonfractured shoulders in conjunction with radiographs of shoulder fractures that were treated with closed reduction and pinning to construct 3-dimensional computer-generated models. We used engineering software to determine the ideal location of pins. We also conducted a literature review. Results The nonfractured adolescent shoulder has an articular surface diameter of 41.3 mm, articular surface thickness of 17.4 mm and neck shaft angle of 36°. Although adolescents and adults have relatively similar shoulder skeletal anatomy, they suffer different types of fractures. In our study, 14 of 16 adolescents suffered Salter–Harris type II fractures. The ideal location for the lateral 2 pins in an anatomically reduced shoulder fracture is 4.4 cm and 8.0 cm from the proximal part of the humeral head directed at 21.2° in the coronal plane relative to the humeral shaft. Conclusion Operative management of proximal humerus fractures in adolescents requires knowledge distinct from that required for adult patients. This is the first study to examine the anatomy of the nonfractured proximal humerus in adolescents. This is also the first study to attempt to model the positioning of percutaneous proximal humerus pins. PMID:20011155

  16. Pin Size Selection for Normograde Intramedullary Pinning of Distal Humeral Fractures in the Dog. (United States)

    Shipov, Anna; Biton, Erez; Shati, Shachar; Joseph, Rotem; Milgram, Joshua


    To determine the optimal intramedullary (IM) pin size for open and percutaneous normograde pinning of the distal humerus. Ex vivo anatomic study. Sixteen canine cadavers. Sixteen pairs of forelimbs were harvested from canine cadavers weighing 25-35 kg. The craniocaudal diameter of the humeral medullary canal, at the distal 80th percentile of its length, was measured on a lateral radiograph. Forelimbs within each pair were allocated to percutaneous or open pinning techniques. Cadavers were divided into three groups based on IM pin diameter relative to the medullary canal diameter: Group 25-35%, Group 36-45%, and Group 46-55%. Pins were inserted normograde into the medial epicondyle and advanced until they exited the proximal humerus. Pin tracts were dissected and damage to soft tissue, bony structures, and location of entry and exit points were documented. The humeri were also cut at the thinnest point of the medial epicondyle and damage to the bone was evaluated. There was no difference in any of the outcomes between the open and percutaneous techniques. Cortical damage was more frequent in Group 46-55% and included blanching and or fracture of the cortex of the medial epicondyle, with fracture occurring in 6/10 limbs in this group. Pins in Group 46-55% exited the farthest and most distal from the optimal exit point and were difficult to place in all limbs. This study supports a recommendation for open and percutaneous pinning of the humerus with IM pins 36-45% of the medullary canal diameter measured at the distal 80th percentile of humeral length. © Copyright 2014 by The American College of Veterinary Surgeons.

  17. Solution structure of the single-domain prolyl cis/trans isomerase PIN1At from Arabidopsis thaliana. (United States)

    Landrieu, Isabelle; Wieruszeski, Jean-Michel; Wintjens, René; Inzé, Dirk; Lippens, Guy


    The 119-amino acid residue prolyl cis/trans isomerase from Arabidopsis thaliana (PIN1At) is similar to the catalytic domain of the human hPIN1. However, PIN1At lacks the N-terminal WW domain that appears to be essential for the hPIN1 function. Here, the solution structure of PIN1At was determined by three-dimensional nuclear magnetic resonance spectroscopy. The PIN1At fold could be superimposed on that of the catalytic domain of hPIN1 and had a 19 residue flexible loop located between strand beta1 and helix alpha1. The dynamical features of this beta1/alpha1-loop, which are characteristic for a region involved in protein-protein interactions, led to exchange broadening in the NMR spectra. When sodium sulfate salt was added to the protein sample, the beta1/alpha1 loop was stabilized and, hence, a complete backbone resonance assignment was obtained. Previously, with a phospho-Cdc25 peptide as substrate, PIN1At had been shown to catalyze the phosphoserine/phosphothreonine prolyl cis/trans isomerization specifically. To map the catalytic site of PIN1At, the phospho-Cdc25 peptide or sodium sulfate salt was added in excess to the protein and chemical shift changes in the backbone amide protons were monitored in the (1)H(N)-(15)N heteronuclear single quantum coherence spectrum. The peptide caused perturbations in the loops between helix alpha4 and strand beta3, between strands beta3 and beta4, in the alpha3 helix, and in the beta1/alpha1 loop. The amide groups of the residues Arg21 and Arg22 showed large chemical shift perturbations upon phospho-Cdc25 peptide or sulfate addition. We conclude that this basic cluster formed by Arg21 and Arg22, both located in the beta1/alpha1 loop, is homologous to that found in the hPIN1 crystal structure (Arg68 and Arg69), which also is involved in sulfate ion binding. We showed that the sulfate group competed for the interaction between PIN1At and the phospho-Cdc25 peptide. In the absence of the WW domain, three hydrophobic residues (Ile

  18. A pinned polymer model of posture control

    CERN Document Server

    Chow, C C; Chow, Carson C; Collins, J J


    A phenomenological model of human posture control is posited. The dynamics are modelled as an elastically pinned polymer under the influence of noise. The model accurately reproduces the two-point correlation functions of experimental posture data and makes predictions for the response function of the postural control system. The physiological and clinical significance of the model is discussed.

  19. Synchronizability on complex networks via pinning control

    Indian Academy of Sciences (India)

    It is proved that the maximum eigenvalue sequence of the principal submatrices of coupling matrix is decreasing. The method of calculating the number of pinning nodes is given based on this theory. The findings reveal the relationship between the decreasing speed of maximum eigenvalue sequence of the principal ...

  20. Physicist pins hopes on particle collider

    CERN Multimedia


    Physicist pins hopes on particle collider By Deseret Morning News Published: Monday, Dec. 31, 27 12:4 a.m. MST FONT Scott Thomas, a 187 State University graduate, is working at the frontiers of science. The theoretical physicist is crafting ways to extract fundamental secrets that seem certain to be uncovered by the Large Hadron Collider.

  1. Pinning Susceptibility Near the Jamming Transition (United States)

    Nashed, Samer; Graves, Amy; Goodrich, Carl; Padgett, Elliot; Liu, Andrea


    The study of jamming in the presence of pinned obstacles is of both practical and theoretical interest. In simulations of soft, bidisperse disks and spheres, we pin a small fraction, nf of particles prior to the equilibration process. The presence of pinned particles is known to lower the critical packing fraction, ϕJ, for jamming. Further, around this threshold there is a peak in a quantity which we have termed the ``pinning susceptibility'': χP =limnf --> 0∂PJ(ϕ/,nf) ∂nf . In the thermodynamic limit, we have posited that χP ~| Δϕ | -γP . Finite-size scaling calculations, involving careful fits of PJ to logistic sigmoidal functions, yield a value for the critical exponent, γP. This new exponent is proposed to be independent of inter-particle potential. Its dependence on dimensionality (2 vs. 3 dimensions) will be discussed. Acknowledgement is made to the Donors of the Petroleum Research Fund administered by the American Chemical Society, NSF grant DMR-1062638 and DOE grant DE-FG02-05ER46199.

  2. Construction of mammary gland specific expression plasmid pIN ...

    African Journals Online (AJOL)



    ). In order to verify plasmid bioactivity, plasmid pIN was transiently transfected into human breast cancer cell line Bcap-37 (Zhang et al.,. 2009). Quantitative PCR results showed that pIN could be transcribed successfully in ...

  3. Vortex distribution in amorphous Mo{sub 80}Ge{sub 20} plates with artificial pinning center

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hitoshi [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Huy, Ho Thanh [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Department of Physics and Electronics, University of Sciences, Vietnam National University HCMC, 227 Nguyen Van Cu, District 5, HoChiMinh City (Viet Nam); Miyoshi, Hiroki; Okamoto, Takuto; Dang, Vu The [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Kato, Masaru [Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Department of Mathematical Science, Osaka Prefecture University1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Ishida, Takekazu, E-mail: [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan)


    Highlights: • We reveal that the vortex distribution in small amorphous Mo{sub 80}Ge{sub 20} superconducting starshaped plate by using a scanning SQUID microscope. • We find that vortex configuration evolves systematically when the applied magnetic field is changed at the several different fields. • We fabricate an artificial dip by Ar ion milling in a mesoscopic plate, and find this works as a pinning center by comparing the vortex behavior in a sample without pins. - Abstract: Vortices in superconductor give rise to a rich variety of phenomena because they interact with shielding currents, temperature gradients, sample defects, boundaries, and other neighboring vortices. It would be very important to understand particular features of vortex states in a downsized system. Our study focuses on vortex states in small star-shaped Mo{sub 80}Ge{sub 20} plates with and without an artificial pin at the plate center. Vortex states are greatly influenced by the sample geometry, the temperature and the magnetic field, and they can be occasionally exotic compared to the bulk case. We use the amorphous Mo{sub 80}Ge{sub 20} films due to the nature of weak pinning in studying vortex configurations. We applied scanning superconducting quantum interference device (SQUID) microscopy because it enables us to see vortex states directly and it is the most sensitive instrument for mapping tiny local current flows or magnetic moments without damaging the sample. We interpreted that vortex configurations had essentially the nature of mirror reflection symmetry in both cases with an artificial pin and without an artificial pin and pinned cases while the influence of disorder was seen in our observation on the specimen without an artificial pin.

  4. Pinning control of complex networked systems synchronization, consensus and flocking of networked systems via pinning

    CERN Document Server

    Su, Housheng


    Synchronization, consensus and flocking are ubiquitous requirements in networked systems. Pinning Control of Complex Networked Systems investigates these requirements by using the pinning control strategy, which aims to control the whole dynamical network with huge numbers of nodes by imposing controllers for only a fraction of the nodes. As the direct control of every node in a dynamical network with huge numbers of nodes might be impossible or unnecessary, it’s then very important to use the pinning control strategy for the synchronization of complex dynamical networks. The research on pinning control strategy in consensus and flocking of multi-agent systems can not only help us to better understand the mechanisms of natural collective phenomena, but also benefit applications in mobile sensor/robot networks. This book offers a valuable resource for researchers and engineers working in the fields of control theory and control engineering.   Housheng Su is an Associate Professor at the Department of Contro...

  5. Pin site care for preventing infections associated with external bone fixators and pins. (United States)

    Lethaby, Anne; Temple, Jenny; Santy-Tomlinson, Julie


    Metal pins are used to apply skeletal traction or external fixation devices in the management of orthopaedic fractures. These percutaneous pins protrude through the skin, and the way in which they are treated after insertion may affect the incidence of pin site infection. This review set out to summarise the evidence of pin site care on infection rates. To assess the effect on infection rates of different methods of cleansing and dressing orthopaedic percutaneous pin sites. In September 2013, for this third update, we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We evaluated all randomised controlled trials (RCTs) that compared the effect on infection and other complication rates of different methods of cleansing or dressing orthopaedic percutaneous pin sites. Two review authors independently assessed the citations retrieved by the search strategies for reports of relevant RCTs, then independently selected trials that satisfied the inclusion criteria, extracted data and undertook quality assessment. A total of eleven trials (572 participants) were eligible for inclusion in the review but not all participants contributed data to each comparison. Three trials compared a cleansing regimen (saline, alcohol, hydrogen peroxide or antibacterial soap) with no cleansing (application of a dry dressing), three trials compared alternative sterile cleansing solutions (saline, alcohol, peroxide, povidone iodine), three trials compared methods of cleansing (one trial compared identical pin site care performed daily or weekly and the two others compared sterile with non sterile techniques), one trial compared daily pin site care with no care and six trials compared different dressings (using different solutions/ointments and dry and impregnated gauze or sponges). One small blinded

  6. Skeletal pin traction: guidelines on postoperative care and support. (United States)

    Davis, Peter

    Orthopaedic pins and wires have been used to apply skeletal traction for many years, and there has been an increase in the use of external fixators (Santy, 2000; Sims and Saleh, 2000). Multiple pins are frequently used and, as such, create potential portals for infection. Infection rates for these pins are reported to be as high as 85 per cent (Sims and Saleh, 2000). However, pin-site management practices are diverse, contradictory and lack consistency.

  7. Reconfigurable superconducting vortex pinning potential for magnetic disks in hybrid structures. (United States)

    Marchiori, Estefani; Curran, Peter J; Kim, Jangyong; Satchell, Nathan; Burnell, Gavin; Bending, Simon J


    High resolution scanning Hall probe microscopy has been used to directly visualise the superconducting vortex behavior in hybrid structures consisting of a square array of micrometer-sized Py ferromagnetic disks covered by a superconducting Nb thin film. At remanence the disks exist in almost fully flux-closed magnetic vortex states, but the observed cloverleaf-like stray fields indicate the presence of weak in-plane anisotropy. Micromagnetic simulations suggest that the most likely origin is an unintentional shape anisotropy. We have studied the pinning of added free superconducting vortices as a function of the magnetisation state of the disks, and identified a range of different phenomena arising from competing energy contributions. We have also observed clear differences in the pinning landscape when the superconductor and the ferromagnet are electron ically coupled or insulated by a thin dielectric layer, with an indication of non-trivial vortex-vortex interactions. We demonstrate a complete reconfiguration of the vortex pinning potential when the magnetisation of the disks evolves from the vortex-like state to an onion-like one under an in-plane magnetic field. Our results are in good qualitative agreement with theoretical predictions and could form the basis of novel superconducting devices based on reconfigurable vortex pinning sites.

  8. Antioxidant Prophylaxis in the Prevention of Prostatic Intraepithelial Neoplasia (PIN) (United States)


    Prevention of Prostatic Intraepithelial Neoplasia (PIN) PRINCIPAL INVESTIGATOR: A. Pratap Kumar, Ph.D...Prophylaxis in the Prevention of Prostatic Intraepithelial 5a. CONTRACT NUMBER Neoplasia (PIN) 5b. GRANT NUMBER W81XWH-04-1-0275 5c...Histopathological changes referred to as Prostatic Intraepithelial Neoplasia (PIN) are considered to be the most likely precursor of prostate cancer. The

  9. Moving vortex phases, dynamical symmetry breaking, and jamming for vortices in honeycomb pinning arrays

    Energy Technology Data Exchange (ETDEWEB)

    Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, Cynthia [Los Alamos National Laboratory


    We show using numerical simulations that vortices in honeycomb pinning arrays can exhibit a remarkable variety of dynamical phases that are distinct from those found for triangular and square pinning arrays. In the honeycomb arrays, it is possible for the interstitial vortices to form dimer or higher n-mer states which have an additional orientational degree of freedom that can lead to the formation of vortex molecular crystals. For filling fractions where dimer states appear, a dynamical symmetry breaking can occur when the dimers flow in one of two possible alignment directions. This leads to transport in the direction transverse to the applied drive. We show that dimerization produces distinct types of moving phases which depend on the direction of the driving force with respect to the pinning lattice symmetry. When the dimers are driven along certain directions, a reorientation of the dimers can produce a jamming phenomenon which results in a strong enhancement in the critical depinning force. The jamming can also cause unusual effects such as an increase in the critical depinning force when the size of the pinning sites is reduced.

  10. Genome-wide identification and evolution of the PIN-FORMED (PIN) gene family in Glycine max. (United States)

    Liu, Yuan; Wei, Haichao


    Soybean (Glycine max) is one of the most important crop plants. Wild and cultivated soybean varieties have significant differences worth further investigation, such as plant morphology, seed size, and seed coat development; these characters may be related to auxin biology. The PIN gene family encodes essential transport proteins in cell-to-cell auxin transport, but little research on soybean PIN genes (GmPIN genes) has been done, especially with respect to the evolution and differences between wild and cultivated soybean. In this study, we retrieved 23 GmPIN genes from the latest updated G. max genome database; six GmPIN protein sequences were changed compared with the previous database. Based on the Plant Genome Duplication Database, 18 GmPIN genes have been involved in segment duplication. Three pairs of GmPIN genes arose after the second soybean genome duplication, and six occurred after the first genome duplication. The duplicated GmPIN genes retained similar expression patterns. All the duplicated GmPIN genes experienced purifying selection (Ka/Ks artificial selection of the soybean PIN genes. Five artificially selected GmPIN genes were identified by comparing the genome sequence of 17 wild and 14 cultivated soybean varieties. Our research provides useful and comprehensive basic information for understanding GmPIN genes.

  11. Radiometric characteristics of new diamond PIN photodiodes (United States)

    Ben Moussa, A.; Schühle, U.; Scholze, F.; Kroth, U.; Haenen, K.; Saito, T.; Campos, J.; Koizumi, S.; Laubis, C.; Richter, M.; Mortet, V.; Theissen, A.; Hochedez, J. F.


    New PIN photodiode devices based on CVD diamond have been produced showing high responsivity in a narrow bandpass around 200 nm. A set of measurement campaigns was carried out to obtain their XUV-to-VIS characterization (responsivity, stability, linearity, homogeneity). The responsivity has been measured from the XUV to the NIR, in the wavelength range of 1 nm to 1127 nm (i.e. 1240 to 1.1 eV). The diamond detectors exhibit a high responsivity of 10 to 30 mA W-1 around 200 nm and demonstrate a visible rejection ratio (200 nm versus 500 nm) of six orders of magnitude. We show that these PIN diamond photodiodes are sensitive sensors in the 200 to 220 nm range, stable under brief irradiation with a good linearity and homogeneity. They will be used for the first time in a solar physics space instrument LYRA, the Large Yield RAdiometer.

  12. Timing analysis of PWR fuel pin failures

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.R.; Wade, N.L.; Katsma, K.R.; Siefken, L.J. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Straka, M. (Halliburton NUS, Idaho Falls, ID (United States))


    Research has been conducted to develop and demonstrate a methodology for calculation of the time interval between receipt of the containment isolation signals and the first fuel pin failure for loss-of-coolant accidents (LOCAs). Demonstration calculations were performed for a Babcock and Wilcox (B W) design (Oconee) and a Westinghouse (W) four-loop design (Seabrook). Sensitivity studies were performed to assess the impacts of fuel pin bumup, axial peaking factor, break size, emergency core cooling system availability, and main coolant pump trip on these times. The analysis was performed using the following codes: FRAPCON-2, for the calculation of steady-state fuel behavior; SCDAP/RELAP5/MOD3 and TRACPF1/MOD1, for the calculation of the transient thermal-hydraulic conditions in the reactor system; and FRAP-T6, for the calculation of transient fuel behavior. In addition to the calculation of fuel pin failure timing, this analysis provides a comparison of the predicted results of SCDAP/RELAP5/MOD3 and TRAC-PFL/MOD1 for large-break LOCA analysis. Using SCDAP/RELAP5/MOD3 thermal-hydraulic data, the shortest time intervals calculated between initiation of containment isolation and fuel pin failure are 10.4 seconds and 19.1 seconds for the B W and W plants, respectively. Using data generated by TRAC-PF1/MOD1, the shortest intervals are 10.3 seconds and 29.1 seconds for the B W and W plants, respectively. These intervals are for a double-ended, offset-shear, cold leg break, using the technical specification maximum peaking factor and applied to fuel with maximum design bumup. Using peaking factors commensurate widi actual bumups would result in longer intervals for both reactor designs. This document also contains appendices A through J of this report.

  13. Cheap and Easy PIN Entering Using Eye Gaze

    Directory of Open Access Journals (Sweden)

    Kasprowski Pawel


    Full Text Available PINs are one of the most popular methods to perform simple and fast user authentication. PIN stands for Personal Identification Number, which may have any number of digits or even letters. Nevertheless, 4-digit PIN is the most common and is used for instance in ATMs or cellular phones. The main advantage of the PIN is that it is easy to remember and fast to enter. There are, however, some drawbacks. One of them - addressed in this paper - is a possibility to steal PIN by a technique called `shoulder surfing'. To avoid such problems a novel method of the PIN entering was proposed. Instead of using a numerical keyboard, the PIN may be entered by eye gazes, which is a hands-free, easy and robust technique. References:



    Bennis, Driss


    In this paper, we investigate the weak Gorenstein global dimensions. We are mainly interested in studying the problem when the left and right weak Gorenstein global dimensions coincide. We first show, for GF-closed rings, that the left and right weak Gorenstein global dimensions are equal when they are finite. Then, we prove that the same equality holds for any two-sided coherent ring. We conclude the paper with some examples and a brief discussion of the scope and limits of our results.

  15. History of Weak Interactions (United States)

    Lee, T. D.


    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  16. NDT of bridge pins on Pennsylvania Dept. of Transportation structures (United States)

    Miller, William J.; Chaney, M. K.


    The Pennsyulvania Department of Transportation conducted a two phase investigation of all fracture critical pin hanger assemblies between 1988 and 1991 of 23 bridges. The first phase consisted of visually inspecting and documenting the condition of the pin assemblies. The second phase involved nondestructive testing of the pins and any hanger assembly parts that the engineer requested. This testing was performed by consultant engineering firms under contract with individual Penn DOT Engineering Districts. The Mehoopany Bridge was the only structure which was tested exclusively by the department's personnel. Twenty fracture critical bridges were consequently retrofitted with support girders or rod support assemblies. The remaining three locations had the pin hanger assemblies removed and the structures were made continuous. Also, the pins were replaced at some of the 20 locations. All removed pins were requested to be retained and sent to the Department's Materials and Testing Laboratory for evaluation testing. A large number of the pins were destroyed during removal and some were discarded during construction. The following criteria was established by department personnel for MTD's testing of the pins and defect comparisons with consulting engineer's test results: 1) modified ASTM A388 standard test, using 18 degree transducer; 2) 1/16 inch saw notches used as reference standard; 3) straight beam and angle test probes for UT of in-place pins; 4) 45 degree and 70 degree angle beam bore hole test probe for verification of pin defects.

  17. Biomechanical analysis of four external fixation pin insertion techniques

    Directory of Open Access Journals (Sweden)

    Dillon Arango


    Full Text Available Having multiple external fixation pin designs and insertion techniques has led to debate as to which combination creates the stiffest construct. This study sought to biomechanically evaluate construct strength using self-drilling (SD and self-tapping (ST pins inserted with either bicortical or unicortical fixation. SD and ST 5.0 mm stainless steel pins were used in combination with bicortical self-drilling (BCSD, bicortical self-tapping (BCST, unicortical self-drilling (UCSD, and unicortical selftapping (UCST techniques. Pre-drilling for the self-tapping pins was completed with a 4.0 mm drill bit using ¾ inch polyvinyl chloride (PVC pipe as the insertional medium. The PVC pin constructs were then loaded to failure in a cantilever bending method using a mechanical testing system. Ten trials of each technique were analyzed. BCSD insertion technique had the highest maximum failure force and stiffness of all tested techniques (P<0.0001. SD pins were significantly stronger to bending forces than ST pins in both the unicortical and bicortical setting (P<0.0001. Three point bending tests of the 5.0 mm SD and ST threaded area showed that threaded portion of the SD pins had a 300 N greater maximum failure force than the ST pins. Biomechanical analysis of external fixation pin insertion techniques demonstrates that bicortical fixation with SD pins achieved the greatest resistance to bending load. Despite both pins being 5.0 mm and constructed from stainless steel, ST and SD behaved differently with regard to maximum failure force and stiffness. This study demonstrates that insertion technique and pin selection are both important variables when attempting to achieve a stiff external fixation construct.

  18. Weak bond screening system (United States)

    Chuang, S. Y.; Chang, F. H.; Bell, J. R.

    Consideration is given to the development of a weak bond screening system which is based on the utilization of a high power ultrasonic (HPU) technique. The instrumentation of the prototype bond strength screening system is described, and the adhesively bonded specimens used in the system developmental effort are detailed. Test results obtained from these specimens are presented in terms of bond strength and level of high power ultrasound irradiation. The following observations were made: (1) for Al/Al specimens, 2.6 sec of HPU irradiation will screen weak bond conditions due to improper preparation of bonding surfaces; (2) for composite/composite specimens, 2.0 sec of HPU irradiation will disrupt weak bonds due to under-cured conditions; (3) for Al honeycomb core with composite skin structure, 3.5 sec of HPU irradiation will disrupt weak bonds due to bad adhesive or oils contamination of bonding surfaces; and (4) for Nomex honeycomb with Al skin structure, 1.3 sec of HPU irradiation will disrupt weak bonds due to bad adhesive.

  19. A proposed parameterization of interface discontinuity factors depending on neighborhood for pin-by-pin diffusion computations for LWR

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, Jose Javier; Garcia-Herranz, Nuria; Ahnert, Carol, E-mail:, E-mail:, E-mail: [Departamento de Ingenieria Nuclear, Universidad Politecnica de Madrid (Spain)


    There exists an interest in performing full core pin-by-pin computations for present nuclear reactors. In such type of problems the use of a transport approximation like the diffusion equation requires the introduction of correction parameters. Interface discontinuity factors can improve the diffusion solution to nearly reproduce a transport solution. Nevertheless, calculating accurate pin-by-pin IDF requires the knowledge of the heterogeneous neutron flux distribution, which depends on the boundary conditions of the pin-cell as well as the local variables along the nuclear reactor operation. As a consequence, it is impractical to compute them for each possible configuration. An alternative to generate accurate pin-by-pin interface discontinuity factors is to calculate reference values using zero-net-current boundary conditions and to synthesize afterwards their dependencies on the main neighborhood variables. In such way the factors can be accurately computed during fine-mesh diffusion calculations by correcting the reference values as a function of the actual environment of the pin-cell in the core. In this paper we propose a parameterization of the pin-by-pin interface discontinuity factors allowing the implementation of a cross sections library able to treat the neighborhood effect. First results are presented for typical PWR configurations. (author)

  20. A mechanism to pin skyrmions in chiral magnets (United States)

    Liu, Ye-Hua; Li, You-Quan


    We propose a mechanism to pin skyrmions in chiral magnetic thin films by introducing local maxima of magnetic exchange strength as pinning centers. The local maxima can be realized by engineering the local density of itinerant electrons. The stationary properties and the dynamical pinning and depinning processes of an isolated skyrmion around a pinning center are studied. We carry out numerical simulations of the Landau-Lifshitz-Gilbert (LLG) equation and find a way to control the position of an isolated skyrmion in a pinning center lattice using electric current pulses. The results are verified by a Thiele equation analysis. We also find that the critical current to depin a skyrmion, which is estimated to have order of magnitude 107-108 A m-2, has linear dependence on the pinning strength.

  1. Optimum Prestress of Tanks with Pinned Base

    DEFF Research Database (Denmark)

    Brøndum-Nielsen, Troels


    Amin Ghali and Eleanor Elliott presented in their paper an interesting suggestion for prestressing of circular tanks without sliding joints. For many prestressed tanks the following construction procedure is adopted:In order to ensure compressive hoop forces in the wall near the base, the wall...... is allowed to slide freely in the radial direction during tensioning (free base).After tensioning such displacements are prevented (pinned base). The present paper addresses the problem of prestress of such tanks.Keywords: circular prestressing; creep properties; prestressed concrete; redistribution...

  2. Bagging Weak Predictors

    DEFF Research Database (Denmark)

    Lukas, Manuel; Hillebrand, Eric

    Relations between economic variables can often not be exploited for forecasting, suggesting that predictors are weak in the sense that estimation uncertainty is larger than bias from ignoring the relation. In this paper, we propose a novel bagging predictor designed for such weak predictor...... variables. The predictor is based on a test for finitesample predictive ability. Our predictor shrinks the OLS estimate not to zero, but towards the null of the test which equates squared bias with estimation variance. We derive the asymptotic distribution and show that the predictor can substantially lower...

  3. Weak layer fracture: facets and depth hoar

    Directory of Open Access Journals (Sweden)

    I. Reiweger


    Full Text Available Understanding failure initiation within weak snow layers is essential for modeling and predicting dry-snow slab avalanches. We therefore performed laboratory experiments with snow samples containing a weak layer consisting of either faceted crystals or depth hoar. During these experiments the samples were loaded with different loading rates and at various tilt angles until fracture. The strength of the samples decreased with increasing loading rate and increasing tilt angle. Additionally, we took pictures of the side of four samples with a high-speed video camera and calculated the displacement using a particle image velocimetry (PIV algorithm. The fracture process within the weak layer could thus be observed in detail. Catastrophic failure started due to a shear fracture just above the interface between the depth hoar layer and the underlying crust.

  4. Flux pinning properties of c-axis correlated pinning centres in PLD-YBCO films

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, H; Yamasaki, H; Develos-Bagarinao, K; Nakagawa, Y; Mawatari, Y; Nie, J C; Obara, H; Kosaka, S [Energy Electronics Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Centre 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)


    Flux pinning properties of pinning centres having correlation along the c-axis in epitaxial YBCO films were investigated by measuring the magnetic-field angle {psi}-dependence of the critical current density J{sub C} and the E-J-characteristics. YBCO films were prepared by using the pulsed-laser-deposition method on four different substrates at three different target-to-substrate distances D. The {psi}-dependence of J{sub C} showed large peaks when magnetic field B was applied parallel to the c-axis (B parallel c), and we observed two types of J{sub C}-peak: that is, a broad peak for the films deposited at small D (50-60 mm), and a narrow peak for the films deposited at large D (112 and 142 mm). The E-J-characteristics followed the power law, E {approx} J{sup n}, and the {psi}-dependence of the n-value also showed broad peaks around B parallel c for the films deposited at D = 50-60 mm, and narrow peaks for the film deposited at D = 112 mm. Based on these results and our previous microstructural observations by AFM and TEM, we confirm that the broad-angle flux pinning effect around B parallel c may be attributed to a high density of elongated precipitates, and the narrow-angle pinning effect around B parallel c may be attributed to dense planar defects parallel to the c-axis.

  5. The pin pixel detector--X-ray imaging

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Marsh, A S; Simmons, J E; Stephenson, R


    The development and testing of a soft X-ray gas pixel detector, which uses connector pins for the anodes is reported. Based on a commercial 100 pin connector block, a prototype detector of aperture 25.4 mm centre dot 25.4 mm can be economically fabricated. The individual pin anodes all show the expected characteristics of small gas detectors capable of counting rates reaching 1 MHz per pin. A 2-dimensional resistive divide readout system has been developed to permit the imaging properties of the detector to be explored in advance of true pixel readout electronics.

  6. Study of the Radiation Hardness of VCSEL and PIN Arrays

    CERN Document Server

    Gan, K.K.; Kagan, H.P.; Kass, R.D.; Law, A.; Rau, A.; Smith, D.S.; Lebbai, M.R.M.; Skubic, P.L.; Abi, B.; Rizardinova, F.


    The silicon trackers of the ATLAS experiment at LHC (CERN) use optical links for data transmission. VCSEL arrays operating at 850 nm are used to transmit optical signals while PIN arrays are used to convert the optical signals into electrical signals. We investigate the feasibility of using the devices at the Super LHC (SLHC). We irradiated VCSEL and GaAs PIN arrays from three vendors and silicon PIN arrays from one vendor. All arrays can be operated up to the SLHC dosage except the GaAs PIN arrays which have very low responsivities after irradiation and hence are probably not suitable for the SLHC application.

  7. Nano-engineered pinning centres in YBCO superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, A., E-mail: [National Institute for Materials Physics Bucharest, 105 bis Atomistilor Str., 077125 Magurele (Romania); School of Metallurgy and Materials, University of Birmingham, Edgbaston, B15 2TT Birmingham (United Kingdom); Dang, V.S. [School of Metallurgy and Materials, University of Birmingham, Edgbaston, B15 2TT Birmingham (United Kingdom); Nano and Energy Center, VNU Hanoi University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi (Viet Nam); Mikheenko, P. [School of Metallurgy and Materials, University of Birmingham, Edgbaston, B15 2TT Birmingham (United Kingdom); Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway)


    Highlights: • Power applications of YBCO films/coated conductors in technological relevant magnetic fields requires nano-engineered pinning centre. • Three approaches have been proposed: substrate decoration, quasi-multilayers, and targets with secondary phase nano-inclusions. • Combination of all three approaches greatly increased critical current in YBCO films. • Bulk pinning force, pinning potential, and critical current density are estimated and discussed in relation with the type and strength of pinning centres related to the defects evidenced by Transmission Electron Microscopy. - Abstract: For practical applications of superconducting materials in applied magnetic fields, artificial pinning centres in addition to natural ones are required to oppose the Lorentz force. These pinning centres are actually various types of defects in the superconductor matrix. The pinning centres can be categorised on their dimension (volume, surface or point) and on their character (normal cores or Δκ cores). Different samples have been produced by Pulsed Laser Deposition, with various thicknesses, temperatures and nanostructured additions to the superconducting matrix. They have been characterized by SQUID Magnetic Properties Measurement System and Physical Properties Measurement System, as well as by Transmission Electron Microscopy (TEM). Correlations between pinning architecture, TEM images, and critical currents at various fields and field orientations will be shown for a large number of YBa{sub 2}Cu{sub 3}O{sub x} films with various types and architectures of artificial pinning centres.

  8. Lower extremity traction pins: indications, technique, and complications. (United States)

    Althausen, Peter L; Hak, David J


    The placement of pins in the lower extremity for the purpose of skeletal traction is a basic skill required by an orthopedic surgeon. These pins are primarily used for the management of fractures and dislocations. Although simple, the insertion and care of these pins can be accompanied by severe complications including damage to neurovascular structures, physeal injury, ligamentous insult, fracture, and infection. We review the techniques of pin insertion at the distal femur, proximal tibia, and calcaneus to provide a foundation for residents and attendings alike so that unnecessary complications may be avoided and proper placement ensured.

  9. Charged weak currents

    CERN Document Server

    Turlay, René


    In this review of charged weak currents the author concentrates on inclusive high energy neutrino physics. The authors discusses the general structure of charged currents, new results on total cross- sections, the Callan-Gross relation, antiquark distributions, scaling violations and tests of QCD. A very short summary on multilepton physics is given. (44 refs).

  10. On Weak Markov's Principle

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich Wilhelm


    We show that the so-called weak Markov's principle (WMP) which states that every pseudo-positive real number is positive is underivable in E-HA + AC. Since allows one to formalize (atl eastl arge parts of) Bishop's constructive mathematics, this makes it unlikely that WMP can be proved within...

  11. Pin-ups: pictures that fascinate and seduce Pin-ups: fotografias que encantam e seduzem

    Directory of Open Access Journals (Sweden)

    Maria Irene Pellegrino de Oliveira Souza


    Full Text Available Starting from photography studies, social anthropology and body visual, this article approaches the social construction of the feminine image through times. It narrates the history of erotic pinups photography and its fetishist elements. Pin-ups have aroused in the end of 19tcentury and it represents the free spirit of women. Slowly, it provokes the breakup of sensuality and sexuality feminine traditionalism. The article also discusses women’s sensuality as a desire object. The pin-ups sensual demure – with a mystery atmosphere – stimulated the eroticism at the beginning of the 20 century and, until nowadays, it provokes admiration, sigh and desire. Com base em estudos sobre fotografia, antropologia social e visual do corpo, este artigo aborda a imagem feminina socialmente construída através dos tempos. Narra o histórico da fotografia erótica de pin-ups e seus elementos fetichistas. As pin-ups surgiram no final do século XIX e representaram o espírito “livre” das mulheres. Sutilmente, incitavam o rompimento do tradicionalismo da época quanto à sensualidade e sexualidade feminina. O artigo aborda também a sensualidade feminina como objeto de desejo. O recato sensual das pin-ups – com ar de mistério – alavancou o erotismo no início do século XX e, até os dias atuais, provoca admiração, suspiros e desejos.

  12. FPIN2 analysis of metal fueled pins

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, T H


    The FPIN2 code is used to calculate the thermal and mechanical behavior of a single fast reactor fuel pin experiencing a wide range of transients. This report describes the modifications and additions made to the FPIN2 code in order to handle metal fueled pins. The changes discussed in this status report have initially focused upon EBR-II driver fuel in order to calculate the temperature histories of EBR-II fuel and to understand the detailed behavior of metal fuel during recent TREAT experiments. Equations describing material behavior of metal fuel including thermal properties, elastic properties, secondary creep and fission gas swelling are presented and were easily incorporated into the FPIN2 code framework. The addition of a fission gas plenum model and a model to close the fuel-clad radial gap at 100% fuel melting required substantial modification to the code. Additional changes were made to handle heat transfer with a sodium bond, eutectic release of cladding axial restraint and eutectic penetration of the cladding. Three example calculations are presented including a study of the effect of fuel creep on axial elongation and temperature contour maps for EBR-II driver fuel. Some results from an FPIN2 analysis of TREAT experiment M2 are discussed.

  13. The Egyptian Hair Pin: practical, sacred, fatal

    Directory of Open Access Journals (Sweden)

    Joann Fletcher


    Full Text Available Generally regarded as little more than a mundane tool employed in daily life, the humble hairpin occasionally played a rather more prominent role in history than has perhaps been appreciated. As the most ancient implements associated with hair styling, simple pins of bone and ivory were commonly employed in Egypt by c.4000 BC as a means of securing long hair in an upswept style (e.g. Petrie and Mace 1901, 21, 34. Although their occasional use by men undermines the assumption that hairpins are 'a relatively certain example of a “gendered” artefact' (Wilfong 1997, 67, the vast majority have been found in female burials. They can be made of bone and ivory, wood, steatite, glass, gold, silver and bronze, and two 12cm long bronze examples were found within the hair of Princess Ahmosi c.1550 BC (Fletcher 1995, 376, 441 while the hair of an anonymous woman at Gurob c.AD 110 had been secured in a bun with pins of bone, tortoiseshell and silver (Walker and Bierbrier 1997, 209.

  14. Lightning Pin Injection Testing on MOSFETS (United States)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.; Koppen, Sandra V.; Mielnik, John J.; Vaughan, Roger K.; Wysocki, Philip F.; Celaya, Jose R.; Saha, Sankalita


    Lightning transients were pin-injected into metal-oxide-semiconductor field-effect transistors (MOSFETs) to induce fault modes. This report documents the test process and results, and provides a basis for subsequent lightning tests. MOSFETs may be present in DC-DC power supplies and electromechanical actuator circuits that may be used on board aircraft. Results show that unprotected MOSFET Gates are susceptible to failure, even when installed in systems in well-shielded and partial-shielded locations. MOSFET Drains and Sources are significantly less susceptible. Device impedance decreased (current increased) after every failure. Such a failure mode may lead to cascading failures, as the damaged MOSFET may allow excessive current to flow through other circuitry. Preliminary assessments on a MOSFET subjected to 20-stroke pin-injection testing demonstrate that Breakdown Voltage, Leakage Current and Threshold Voltage characteristics show damage, while the device continues to meet manufacturer performance specifications. The purpose of this research is to develop validated tools, technologies, and techniques for automated detection, diagnosis and prognosis that enable mitigation of adverse events during flight, such as from lightning transients; and to understand the interplay between lightning-induced surges and aging (i.e. humidity, vibration thermal stress, etc.) on component degradation.

  15. Medio-lateral entry pin versus lateral entry pin for displaced pediatric supracondylar fractures: A comparative, prospective study

    Directory of Open Access Journals (Sweden)

    Manoj Kandel


    Full Text Available Background & Objectives: Supracondylar fracture is one of the commonest fractures in children. Although the technique of pinning is controversial, percutaneous medio-lateral entry pinning is theoretically considered more stable biomechanical construct. The drawback of this method is injury to ulnar nerve which is not encountered in only lateral entry pinning.Materials & Methods: This was a prospective, comparative and observational study done in 60 patients which was alternately divided into two groups. The first group (A underwent medio-lateral entry pinning and the second group (B underwent lateral entry pinning. They were followed for 24 weeks and the outcome was assessed using Flynn’s criteria.Results: At twenty-four weeks, the mean loss of range of motion of elbow in medio-lateral pinning group was 3.70 degrees (SD±1.93 and that in lateral pinning group was 4.23 degrees (SD ±1.38. The mean loss in carrying angle at twenty-four weeks in medio-lateral group was 2.93 degrees (SD±2.19 and that in lateral group was 4.17 (SD±2.24. There were 2 (6.67% cases of iatrogenic ulnar nerve injury in medio-lateral pinning group. Out of thirty patients, in medio-lateral pinning group, 25 had excellent results, 5 had good results and none had fair or poor results. While out of 30 patients in lateral pinning group, 23 had excellent results, 7 had good results and none had fair or poor results.Conclusion: There is no significant difference in outcome in terms of loss of carrying angle and range of motion between the medio-lateral pinning group and the lateral pinning group at the end of 6 months.Journal of College of Medical Sciences-Nepal, Vol.11(4 2015: 28-31

  16. Weak lensing with GEST (United States)

    Rhodes, J. D.; Bennett, D. P.; Kaiser, N.


    Weak lensing by large-scale structure (cosmic shear) provides an opportunity to directly observe the dark matter in the universe. Current ground-based and space-based surveys have demonstrated the efficacy of this technique in determining the mass distribution and thus placing constraints on cosmological parameters such as Ω m, σ 8, and the bias parameter b. Current surveys have been hampered by the comparatively low resolution of ground-based telescopes and the small field of view of HST. To make significant progress in this field, wide field space-based surveys are needed. The Galactic Exoplanet Survey Telescope (GEST) will be able to provide 500- 1000 sqare degrees with a resolution of better than 0.2 arcseconds in multiple filters. This will make it an ideal instrument for a weak lensing survey.

  17. Composite weak bosons

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.


    Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.

  18. Kinetic Isotope Effects Support the Twisted Amide Mechanism of Pin1 Peptidyl-Prolyl Isomerase (United States)

    Mercedes-Camacho, Ana Y.; Mullins, Ashley B.; Mason, Matthew D.; Xu, Guoyan G.; Mahoney, Brendan J.; Wang, Xingsheng; Peng, Jeffrey W.; Etzkorn, Felicia A.


    The Pin1 peptidyl-prolyl isomerase (PPIase) catalyzes isomerization of pSer/pThr-Pro motifs in regulating the cell cycle. Peptide substrates, Ac–Phe–Phe–phosphoSer–Pro–Arg–p-nitroaniline, were synthesized in unlabeled form, and with deuterium labeled Ser-d3 and Pro-d7 amino acids. Kinetic data was collected as a function of Pin1 concentration to measure kinetic isotope effects (KIE) on catalytic efficiency (kcat/Km). The normal secondary (2°) KIE value measured for the Ser-d3 substrate (kH/kD = 1.6 ± 0.2) indicates that the serine carbonyl does not rehybridize from sp2 to sp3 in the rate-determining step, ruling out a nucleophilic addition mechanism. The normal 2° KIE can be explained by hyperconjugation between Ser α-C–H/D and C=O, and release of steric strain upon rotation of the amide bond from cis to syn-exo. The inverse 2° KIE value (kH/kD = 0.86 ± 0.08) measured for the Pro-d7 substrate indicates rehybridization of the prolyl nitrogen from sp2 to sp3 during the rate-limiting step of isomerization. No solvent kinetic isotope was measured by NMR exchange spectroscopy (EXSY) (kH2O/kD2O = 0.92 ± 0.12), indicating little or no involvement of exchangeable protons in the mechanism. These results support the formation of a simple twisted-amide transition state as the mechanism for peptidyl prolyl isomerization catalyzed by Pin1. A model of the reaction mechanism is presented using crystal structures of Pin1 with ground state analogues and an inhibitor that resembles a twisted amide transition state. PMID:24116866

  19. Pinning Stabilizes Neighboring Surface Nanobubbles against Ostwald Ripening

    NARCIS (Netherlands)

    Dollet, B.; Lohse, Detlef


    Pinning of the contact line and gas oversaturation explain the stability of single surface nanobubbles. In this article, we theoretically show that the pinning also suppresses the Ostwald ripening process between neighboring surface nanobubbles, thus explaining why in a population of neighboring

  20. Pin cherry effects on Allegheny hardwood stand development (United States)

    Todd E. Ristau; Stephen B. Horsley


    Pin cherry (Prunus pensylvanica L.) develops an early height advantage over associated species. Data from three long-term studies, extending up to 70 years after complete overstory removal, were used to evaluate the effects of pin cherry density on associates. Survival of seedling-origin stems of black cherry (Prunus serotina Ehrh...

  1. Clinical standards in skeletal traction pin site care. (United States)

    Jones-Walton, P


    This descriptive study describes orthopaedic nursing practice behavior relevant to the treatment of skeletal traction pin sites. Data describe clinical practice norms for such variables as product usage, treatment frequency, and aseptic technique. These norms can be used as the basis for further scientific investigation of pin care and the development of uniform treatment standards within the nursing specialty domain.

  2. Inscuteable Regulates the Pins-Mud Spindle Orientation Pathway (United States)

    Mauser, Jonathon F.; Prehoda, Kenneth E.


    During asymmetric cell division, alignment of the mitotic spindle with the cell polarity axis ensures that the cleavage furrow separates fate determinants into distinct daughter cells. The protein Inscuteable (Insc) is thought to link cell polarity and spindle positioning in diverse systems by binding the polarity protein Bazooka (Baz; aka Par-3) and the spindle orienting protein Partner of Inscuteable (Pins; mPins or LGN in mammals). Here we investigate the mechanism of spindle orientation by the Insc-Pins complex. Previously, we defined two Pins spindle orientation pathways: a complex with Mushroom body defect (Mud; NuMA in mammals) is required for full activity, whereas binding to Discs large (Dlg) is sufficient for partial activity. In the current study, we have examined the role of Inscuteable in mediating downstream Pins-mediated spindle orientation pathways. We find that the Insc-Pins complex requires Gαi for partial activity and that the complex specifically recruits Dlg but not Mud. In vitro competition experiments revealed that Insc and Mud compete for binding to the Pins TPR motifs, while Dlg can form a ternary complex with Insc-Pins. Our results suggest that Insc does not passively couple polarity and spindle orientation but preferentially inhibits the Mud pathway, while allowing the Dlg pathway to remain active. Insc-regulated complex assembly may ensure that the spindle is attached to the cortex (via Dlg) before activation of spindle pulling forces by Dynein/Dynactin (via Mud). PMID:22253744

  3. Inscuteable regulates the Pins-Mud spindle orientation pathway.

    Directory of Open Access Journals (Sweden)

    Jonathon F Mauser

    Full Text Available During asymmetric cell division, alignment of the mitotic spindle with the cell polarity axis ensures that the cleavage furrow separates fate determinants into distinct daughter cells. The protein Inscuteable (Insc is thought to link cell polarity and spindle positioning in diverse systems by binding the polarity protein Bazooka (Baz; aka Par-3 and the spindle orienting protein Partner of Inscuteable (Pins; mPins or LGN in mammals. Here we investigate the mechanism of spindle orientation by the Insc-Pins complex. Previously, we defined two Pins spindle orientation pathways: a complex with Mushroom body defect (Mud; NuMA in mammals is required for full activity, whereas binding to Discs large (Dlg is sufficient for partial activity. In the current study, we have examined the role of Inscuteable in mediating downstream Pins-mediated spindle orientation pathways. We find that the Insc-Pins complex requires Gαi for partial activity and that the complex specifically recruits Dlg but not Mud. In vitro competition experiments revealed that Insc and Mud compete for binding to the Pins TPR motifs, while Dlg can form a ternary complex with Insc-Pins. Our results suggest that Insc does not passively couple polarity and spindle orientation but preferentially inhibits the Mud pathway, while allowing the Dlg pathway to remain active. Insc-regulated complex assembly may ensure that the spindle is attached to the cortex (via Dlg before activation of spindle pulling forces by Dynein/Dynactin (via Mud.

  4. Optical fuel pin scanner. [Patent application; for reading identifications (United States)

    Kirchner, T.L.; Powers, H.G.


    This patent relates to an optical identification system developed for post-irradiation disassembly and analysis of fuel bundle assemblies. The apparatus is designed to be lowered onto a stationary fuel pin to read identification numbers or letters imprinted on the circumference of the top fuel pin and cap. (DLC)

  5. Ankle Arthrodesis Using a Vertical Steinman's Pin in a Severely ...

    African Journals Online (AJOL)

    There was one case of pin site infection and one case of cellulitis. According to the Mazur ankle score at final follow-up, 22 patients (67%) had excellent results, 8 (24%) good, 2 (6%) fair and 1(3%) poor results. Conclusion: Ankle arthrodesis using a vertical Steinman's pin is a reliable technique in low resource settings and ...

  6. Fundamental Characteristics of a Pinned Photodiode CMOS Pixels

    NARCIS (Netherlands)

    Xu, Y.


    This thesis gives an insightful analysis of the pinned photodiode 4T CMOS pixel from three different aspects. Firstly, from the charge accumulated aspect, the PPD full well capacity and related parameters of influence are investigated such as the pinning voltage, and transfer gate potential barrier.

  7. Pin stack array for thermoacoustic energy conversion (United States)

    Keolian, Robert M.; Swift, Gregory W.


    A thermoacoustic stack for connecting two heat exchangers in a thermoacoustic energy converter provides a convex fluid-solid interface in a plane perpendicular to an axis for acoustic oscillation of fluid between the two heat exchangers. The convex surfaces increase the ratio of the fluid volume in the effective thermoacoustic volume that is displaced from the convex surface to the fluid volume that is adjacent the surface within which viscous energy losses occur. Increasing the volume ratio results in an increase in the ratio of transferred thermal energy to viscous energy losses, with a concomitant increase in operating efficiency of the thermoacoustic converter. The convex surfaces may be easily provided by a pin array having elements arranged parallel to the direction of acoustic oscillations and with effective radial dimensions much smaller than the thicknesses of the viscous energy loss and thermoacoustic energy transfer volumes.

  8. Progressive inhibition of neuromuscular structures (PINS) technique. (United States)

    Dowling, D J


    Progressive inhibition of neuromuscular structures (PINS) is a technique that can be included in the osteopathic manipulative treatment repertoire. It relies on knowledge of anatomy and neuromuscular physiologic features as well as on standard forms of osteopathic palpatory diagnosis and treatment. It is a variant of the inhibition technique that has been taught as an osteopathic manipulative technique for many years, and it bears some resemblance to other manual medicine techniques. The emphasis of the approach is the determination of the alteration of the tissues due to dysfunction, delivering treatment based on palpatory evaluation and patient feedback. Two related points are initially chosen, followed by a progression from one to the other. Relationships to similar techniques are also discussed. Theoretical as well as selected practical applications are presented.

  9. Cracking Bank PINs by Playing Mastermind (United States)

    Focardi, Riccardo; Luccio, Flaminia L.

    The bank director was pretty upset noticing Joe, the system administrator, spending his spare time playing Mastermind, an old useless game of the 70ies. He had fought the instinct of telling him how to better spend his life, just limiting to look at him in disgust long enough to be certain to be noticed. No wonder when the next day the director fell on his chair astonished while reading, on the newspaper, about a huge digital fraud on the ATMs of his bank, with millions of Euros stolen by a team of hackers all around the world. The article mentioned how the hackers had 'played with the bank computers just like playing Mastermind', being able to disclose thousands of user PINs during the one-hour lunch break. That precise moment, a second before falling senseless, he understood the subtle smile on Joe's face the day before, while training at his preferred game, Mastermind.

  10. The Weak Haagerup Property II

    DEFF Research Database (Denmark)

    Haagerup, Uffe; Knudby, Søren


    The weak Haagerup property for locally compact groups and the weak Haagerup constant were recently introduced by the second author [27]. The weak Haagerup property is weaker than both weak amenability introduced by Cowling and the first author [9] and the Haagerup property introduced by Connes [6......] and Choda [5]. In this paper, it is shown that a connected simple Lie group G has the weak Haagerup property if and only if the real rank of G is zero or one. Hence for connected simple Lie groups the weak Haagerup property coincides with weak amenability. Moreover, it turns out that for connected simple...... Lie groups the weak Haagerup constant coincides with the weak amenability constant, although this is not true for locally compact groups in general. It is also shown that the semidirect product R2 × SL(2,R) does not have the weak Haagerup property....

  11. Organic p-i-n solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Maennig, B.; Drechsel, J.; Gebeyehu, D.; Kozlowski, F.; Werner, A.; Li, F.; Grundmann, S.; Sonntag, S.; Koch, M.; Leo, K.; Pfeiffer, M. [Institut fuer Angewandte Photophysik, Technische Universitaet Dresden, 01062, Dresden (Germany); Simon, P. [Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Dresden (Germany); Hoppe, H.; Meissner, D.; Sariciftci, N.S. [Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, 4040, Linz (Austria); Riedel, I.; Dyakonov, V.; Parisi, J. [Energy and Semiconductor Research Laboratory, Institute of Physics, University of Oldenburg, 26111, Oldenburg (Germany)


    We introduce a p-i-n-type heterojunction architecture for organic solar cells where the active region is sandwiched between two doped wide-gap layers. The term p-i-n means here a layer sequence in the form p-doped layer, intrinsic layer and n-doped layer. The doping is realized by controlled co-evaporation using organic dopants and leads to conductivities of 10{sup -4} to 10{sup -5} S/cm in the p- and n-doped wide-gap layers, respectively. The photoactive layer is formed by a mixture of phthalocyanine zinc (ZnPc) and the fullerene C{sub 60} and shows mainly amorphous morphology. As a first step towards p-i-n structures, we show the advantage of using wide-gap layers in M-i-p-type diodes (metal layer-intrinsic layer-p-doped layer). The solar cells exhibit a maximum external quantum efficiency of 40% between 630-nm and 700-nm wavelength. With the help of an optical multilayer model, we optimize the optical properties of the solar cells by placing the active region at the maximum of the optical field distribution. The results of the model are largely confirmed by the experimental findings. For an optically optimized device, we find an internal quantum efficiency of around 82% under short-circuit conditions. Adding a layer of 10-nm thickness of the red material N,N'-dimethylperylene-3,4:9,10-dicarboximide (Me-PTCDI) to the active region, a power-conversion efficiency of 1.9% for a single cell is obtained. Such optically thin cells with high internal quantum efficiency are an important step towards high-efficiency tandem cells. First tandem cells which are not yet optimized already show 2.4% power-conversion efficiency under simulated AM 1.5 illumination of 125 mW/cm{sup 2}. (orig.)

  12. PIN-Dependent Auxin Transport: Action, Regulation, and Evolution (United States)

    Adamowski, Maciek; Friml, Jiří


    Auxin participates in a multitude of developmental processes, as well as responses to environmental cues. Compared with other plant hormones, auxin exhibits a unique property, as it undergoes directional, cell-to-cell transport facilitated by plasma membrane-localized transport proteins. Among them, a prominent role has been ascribed to the PIN family of auxin efflux facilitators. PIN proteins direct polar auxin transport on account of their asymmetric subcellular localizations. In this review, we provide an overview of the multiple developmental roles of PIN proteins, including the atypical endoplasmic reticulum-localized members of the family, and look at the family from an evolutionary perspective. Next, we cover the cell biological and molecular aspects of PIN function, in particular the establishment of their polar subcellular localization. Hormonal and environmental inputs into the regulation of PIN action are summarized as well. PMID:25604445

  13. Retractable Pin Tools for the Friction Stir Welding Process (United States)


    Two companies have successfully commercialized a specialized welding tool developed at the Marshall Space Flight Center (MSFC). Friction stir welding uses the high rotational speed of a tool and the resulting frictional heat created from contact to crush, 'stir' together, and forge a bond between two metal alloys. It has had a major drawback, reliance on a single-piece pin tool. The pin is slowly plunged into the joint between two materials to be welded and rotated as high speed. At the end of the weld, the single-piece pin tool is retracted and leaves a 'keyhole,' something which is unacceptable when welding cylindrical objects such as drums, pipes and storage tanks. Another drawback is the requirement for different-length pin tools when welding materials of varying thickness. An engineer at the MSFC helped design an automatic retractable pin tool that uses a computer-controlled motor to automatically retract the pin into the shoulder of the tool at the end of the weld, preventing keyholes. This design allows the pin angle and length to be adjusted for changes in material thickness and results in a smooth hole closure at the end of the weld. Benefits of friction stir welding, using the MSFC retractable pin tool technology, include the following: The ability to weld a wide range of alloys, including previously unweldable and composite materials; provision of twice the fatigue resistance of fusion welds and no keyholes; minimization of material distortion; no creation of hazards such as welding fumes, radiation, high voltage, liquid metals, or arcing; automatic retraction of the pin at the end of the weld; and maintaining full penetration of the pin.

  14. Development of a prototype pin-by-pin fine mesh calculation code for BWR core analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Kenichi; Yamamoto, Akio; Yamane, Yoshihiro [Nagoya University, Nagoya (Japan); Kosaka, Shinya; Hirano, Gou [TEPCO SYSTEMS CORPORATION, Tokyo (Japan)


    A prototype core analysis code for BWR, SUBARU, which is based on the three-dimensional pin-by-pin fine-mesh calculation, is being developed. The SUBARU code has several features, e.g., incorporation of the SP3 transport theory, capability to treat the staggered meshes, and so on. In this paper, to estimate the prediction accuracy of this core analysis code, a hypothetical 2D ABWR core which is consisted by 8x8 low-enrichment UO{sub 2} fuel assembly, 9x9 high-enrichment UO{sub 2} fuel assembly, and 10x10 MOX fuel assembly is analyzed. To investigate the prediction accuracy, we compared the pin-wise fission rate distribution which was obtained by the cell-heterogeneous transport calculation by MOC. To evaluate the computational costs, a hypothetical 3D ABWR core is also used. These results suggest that SUBARU would have enough accuracy and reasonable calculation costs for the reference BWR core analysis when further investigation is taken into account. (authors)

  15. Zener pinning by coherent particles: pinning efficiency and particle reorientation mechanisms (United States)

    Zhou, Jian; Li, Chao; Guan, Miao; Ren, Fuzeng; Wang, Xiaonan; Zhang, Shunhu; Zhao, Bingbing


    Zener pinning by coherent particles in copper-nickel model alloys has been studied using molecular dynamics simulations. It is found that 4 nm Ni particles were easily cut by migrating Cu grain boundaries during boundary passage, while 7-8 nm particles were harder to cut and coherency-to-incoherency change occurred for some boundaries. Due to low volume fraction and easy cutting, 4 nm particles had a limited pinning effect on grain boundary motion. The increase in volume fraction and the suppressed cutting for 7-8 nm particles caused the boundary motion to be significantly retarded. Different grain boundaries exhibited the distinct ability to move past the same size particle. Significantly, with the pinning effect of Ni particles, misorientation dependence of boundary migration velocity became obvious, which is consistent with the findings in practical materials. During or after passage, the Ni particles were found to change orientation to become coherent with grain growth via various atomistic mechanisms. The mechanisms were discussed with respect to particle size and boundary misorientation.

  16. Measurement of weak radioactivity

    CERN Document Server

    Theodorsson , P


    This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one type can be used, the selection of the most suitable system is shown.

  17. ICU-Acquired Weakness. (United States)

    Jolley, Sarah E; Bunnell, Aaron E; Hough, Catherine L


    Survivorship after critical illness is an increasingly important health-care concern as ICU use continues to increase while ICU mortality is decreasing. Survivors of critical illness experience marked disability and impairments in physical and cognitive function that persist for years after their initial ICU stay. Newfound impairment is associated with increased health-care costs and use, reductions in health-related quality of life, and prolonged unemployment. Weakness, critical illness neuropathy and/or myopathy, and muscle atrophy are common in patients who are critically ill, with up to 80% of patients admitted to the ICU developing some form of neuromuscular dysfunction. ICU-acquired weakness (ICUAW) is associated with longer durations of mechanical ventilation and hospitalization, along with greater functional impairment for survivors. Although there is increasing recognition of ICUAW as a clinical entity, significant knowledge gaps exist concerning identifying patients at high risk for its development and understanding its role in long-term outcomes after critical illness. This review addresses the epidemiologic and pathophysiologic aspects of ICUAW; highlights the diagnostic challenges associated with its diagnosis in patients who are critically ill; and proposes, to our knowledge, a novel strategy for identifying ICUAW. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  18. Fabrication and performance characteristics of a CsI(Tl)/PIN diode radiation sensor for industrial applications. (United States)

    Kim, Han Soo; Ha, Jang Ho; Park, Se Hwan; Cho, Seung Yeon; Kim, Yong Kyun


    CsI(Tl)/PIN diode radiation sensors were fabricated for application in various fields such as an NDT and an environmental radiation monitoring system. CsI(Tl) crystals of 11x11x21mm(3) were processed as optical grade from a CsI(Tl) ingot and matched with PIN diodes in consideration of the light loss and the external impact. The photodiode signal is amplified by a low-noise preamplifier and a pulse shape amplifier. At room temperature, the fabricated CsI(Tl)/PIN diode radiation sensors demonstrate an energy resolution of 7.9% for 660keV gamma rays and 4.9% for 1330keV. The fluctuation of the directional dependency was below 14% from 0 to 90 degree for the incident 660keV gamma rays. The compactness, the low-voltage power supply and the physical hardness are very useful features for industrial applications of the fabricated CsI(Tl)/PIN diode sensor.

  19. Pin-based electrochemical glucose sensor with multiplexing possibilities. (United States)

    Rama, Estefanía C; Costa-García, Agustín; Fernández-Abedul, M Teresa


    This work describes the use of mass-produced stainless-steel pins as low-cost electrodes to develop simple and portable amperometric glucose biosensors. A potentiostatic three-electrode configuration device is designed using two bare pins as reference and counter electrodes, and a carbon-ink coated pin as working electrode. Conventional transparency film without any pretreatment is used to punch the pins and contain the measurement solution. The interface to the potentiostat is very simple since it is based on a commercial female connection. This electrochemical system is applied to glucose determination using a bienzymatic sensor phase (glucose oxidase/horseradish peroxidase) with ferrocyanide as electron-transfer mediator, achieving a linear range from 0.05 to 1mM. It shows analytical characteristics comparable to glucose sensors previously reported using conventional electrodes, and its application for real food samples provides good results. The easy modification of the position of the pins allows designing different configurations with possibility of performing simultaneous measurements. This is demonstrated through a specific design that includes four pin working-electrodes. Different concentrations of antibody labeled with alkaline phosphatase are immobilized on the pin-heads and after enzymatic conversion of 3-indoxylphosphate and silver nitrate, metallic silver is determined by anodic stripping voltammetry. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Pin tract infection with external fixation of pediatric fractures. (United States)

    Schalamon, Johannes; Petnehazy, Thomas; Ainoedhofer, Herwig; Zwick, Ernst B; Singer, Georg; Hoellwarth, Michael E


    This study aimed to evaluate the incidence and severity of pin tract infections in a series of pediatric trauma patients. All pediatric trauma patients with external fixation who were treated at our institution between 1998 and 2003 were included. The charts of 30 children (20 males; 10 females; mean age, 13.2 years; range, 7-19 years) with 37 episodes of external fixation were reviewed. The average duration of external fixation was 17.5 weeks (range, 1-94 weeks). Pin tract infections were graded using the Dahl classification. Bacterial cultures were obtained in case of drainage from the pin site. In 18 (48%) of 37 external fixations, no signs of infection occurred during the treatment period. In the remaining 19 (52%) external fixations, 35 episodes of infection were documented. Most infections were mild or moderate, whereas only 3 (9%) severe deep infections were noted (grade 5). Six (17%) infections healed with local application of rifamycin, whereas 27 (77%) of 35 infections were successfully treated with systemic antibiotics (cefuroxime, clindamycin). The remaining 2 infections (6%) required removal of a pin. Pin tract infection occurred in half of the patients who were treated with external fixations. Most of the pin site infections in the present series were mild and could be managed by local or systemic application of antibiotics. The occurrence of pin tract infections did not require a change of the method of stabilization.

  1. Loss of Pin1 Suppresses Hedgehog-Driven Medulloblastoma Tumorigenesis. (United States)

    Xu, Tao; Zhang, Honglai; Park, Sung-Soo; Venneti, Sriram; Kuick, Rork; Ha, Kimberly; Michael, Lowell Evan; Santi, Mariarita; Uchida, Chiyoko; Uchida, Takafumi; Srinivasan, Ashok; Olson, James M; Dlugosz, Andrzej A; Camelo-Piragua, Sandra; Rual, Jean-François


    Medulloblastoma is the most common malignant brain tumor in children. Therapeutic approaches to medulloblastoma (combination of surgery, radiotherapy, and chemotherapy) have led to significant improvements, but these are achieved at a high cost to quality of life. Alternative therapeutic approaches are needed. Genetic mutations leading to the activation of the Hedgehog pathway drive tumorigenesis in ~30% of medulloblastoma. In a yeast two-hybrid proteomic screen, we discovered a novel interaction between GLI1, a key transcription factor for the mediation of Hedgehog signals, and PIN1, a peptidylprolyl cis/trans isomerase that regulates the postphosphorylation fate of its targets. The GLI1/PIN1 interaction was validated by reciprocal pulldowns using epitope-tagged proteins in HEK293T cells as well as by co-immunoprecipiations of the endogenous proteins in a medulloblastoma cell line. Our results support a molecular model in which PIN1 promotes GLI1 protein abundance, thus contributing to the positive regulation of Hedgehog signals. Most importantly, in vivo functional analyses of Pin1 in the GFAP-tTA;TRE-SmoA1 mouse model of Hedgehog-driven medulloblastoma demonstrate that the loss of Pin1 impairs tumor development and dramatically increases survival. In summary, the discovery of the GLI1/PIN1 interaction uncovers PIN1 as a novel therapeutic target in Hedgehog-driven medulloblastoma tumorigenesis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Turbulent flow over a pin fin array: Parametric study (United States)

    Cruz Perez, Benjamin

    Modern jet engines reach very high combustion temperatures to achieve higher thermal efficiencies which can damage the turbine blades. Damage can occur in the turbine blade due to the temperature difference between the interior and the exterior causing material creep and thermal fatigue. To avoid damage efficient cooling systems have been proposed such as film cooling, internal channels, and pin fins. This research focus on pin fins, which are small protruding cylinders at the trailing edge of the turbine blade, specifically the purpose of this work is to find the optimum layout of pin fins such that it enhances the heat transfer process with a minimum pressure drop. To find this optimum pin configuration experiments and numerical simulations have been performed. Experiments consisted on determine the friction factor for pin fins arrays ranging from one row to ten rows at equally spaced intervals and various Reynolds number (Re). Experiments demonstrated that for arrays with more than 6 rows of pin fins the friction factor follows a decreasing trend as the Re increases and the pressure drop due to the array to the total pressure drop ratio is about 90%. The numerical method used for the Direct Numerical Simulations (DNS) is the same presented by [1]. DNS consisted on changing the spacing between the pin fins and the Re. For a fixed spanwise distance the streamwise distance was varied and for a fixed streamwise distance the spanwise distance was varied for a constant Re. Finally, for a fixed spacing the Re was varied. The numerical results shows that the heat transfer trends to increase as the spacing between the pin fins becomes smaller, and the friction factor decreases as the spacing becomes larger. For a fixed pin configuration the heat transfer and the friction factor increases with decreasing Re.

  3. Use of cranial fixation pins in pediatric neurosurgery. (United States)

    Berry, Cherisse; Sandberg, David I; Hoh, Daniel J; Krieger, Mark D; McComb, J Gordon


    Cranial fixation using pins during neurosurgical procedures is commonplace; however, parameters for the application of these devices in pediatric patients are not well defined. Variability in the thickness of the developing cranium necessitates age-specific considerations to reduce the risk of adverse events. To suggest possible guidelines for the use of cranial fixation pins in children, we surveyed neurosurgeons treating pediatric patients regarding their experience with such devices. An Institutional Review Board-approved, 30-item multiple choice survey was provided by electronic mail to 605 neurosurgeons treating pediatric patients. The survey included specific questions regarding their experience with cranial fixation pins with respect to age ranges of patients, selection of pin size, type of pin pressure applied, and complications encountered. One hundred sixty-four (27%) responses were received. One hundred fifty-eight of the 164 (96%) neurosurgeons reported using cranial fixation pins in their pediatric practice. Forty-four of the 164 (27%) apply fixation pins in patients aged 1 to 2 years. Eighty-two (50%) apply pins in patients aged 2 to 3 years, and 89 (54%) apply pins in patients aged 3 to 4 years. For patients aged 2 to 5 years old, the majority of responders use between 10 and 40 pounds of pressure, whereas for those older than 5 years of age, most use between 30 and 40 pounds of pressure. After age 10, patients are treated as adults. Eighty-nine of the 164 (54%) responders reported complications directly related to the use of cranial fixation pins, including cranial fracture, epidural or subdural hematoma, scalp laceration, or cerebrospinal fluid leak. One hundred fifty-four of the 164 (94%) neurosurgeons responded that they are not aware of any standard guidelines for cranial fixation pin use in pediatric patients. Seven (4%) who stated that they were aware of guidelines did not describe where they obtained those guidelines. Cranial fixation pins

  4. Free precession of neutron stars: Role of possible vortex pinning

    Energy Technology Data Exchange (ETDEWEB)

    Shaham, J.


    Vortex pinning affects neutron stellar free precession by modifying its frequency and geometry, in a gyroscopic effect. For neutron stars with low oblateness, the free precession frequency is given by p/=psi..cap omega.., where psi is the ratio of moments of inertia of the pinned superfluid to the rigid component of the rest of the star, and ..cap omega.. is half the superfluid vorticity. This poses a severe difficulty on any interpretation of the 35/sup d/ cycle in Her X-1 in terms of neutron stellar wobble, if vortex pinning exists.

  5. Weak Quantum Ergodicity

    CERN Document Server

    Kaplan, L


    We examine the consequences of classical ergodicity for the localization properties of individual quantum eigenstates in the classical limit. We note that the well known Schnirelman result is a weaker form of quantum ergodicity than the one implied by random matrix theory. This suggests the possibility of systems with non-gaussian random eigenstates which are nonetheless ergodic in the sense of Schnirelman and lead to ergodic transport in the classical limit. These we call "weakly quantum ergodic.'' Indeed for a class of "slow ergodic" classical systems, it is found that each eigenstate becomes localized to an ever decreasing fraction of the available state space, in the semiclassical limit. Nevertheless, each eigenstate in this limit covers phase space evenly on any classical scale, and long-time transport properties betwen individual quantum states remain ergodic due to the diffractive effects which dominate quantum phase space exploration.

  6. Superconducting vortex pinning with artificial magnetic nanostructures.

    Energy Technology Data Exchange (ETDEWEB)

    Velez, M.; Martin, J. I.; Villegas, J. E.; Hoffmann, A.; Gonzalez, E. M.; Vicent, J. L.; Schuller, I. K.; Univ. de Oviedo-CINN; Unite Mixte de Physique CNRS/Thales; Univ. Paris-Sud; Univ.Complutense de Madrid; Univ. California at San Diego


    This review is dedicated to summarizing the recent research on vortex dynamics and pinning effects in superconducting films with artificial magnetic structures. The fabrication of hybrid superconducting/magnetic systems is presented together with the wide variety of properties that arise from the interaction between the superconducting vortex lattice and the artificial magnetic nanostructures. Specifically, we review the role that the most important parameters in the vortex dynamics of films with regular array of dots play. In particular, we discuss the phenomena that appear when the symmetry of a regular dot array is distorted from regularity towards complete disorder including rectangular, asymmetric, and aperiodic arrays. The interesting phenomena that appear include vortex-lattice reconfigurations, anisotropic dynamics, channeling, and guided motion as well as ratchet effects. The different regimes are summarized in a phase diagram indicating the transitions that take place as the characteristic distances of the array are modified respect to the superconducting coherence length. Future directions are sketched out indicating the vast open area of research in this field.

  7. Equilibrium ultrastable glasses produced by random pinning

    Energy Technology Data Exchange (ETDEWEB)

    Hocky, Glen M.; Reichman, David R. [Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027 (United States); Berthier, Ludovic [Laboratoire Charles Coulomb, UMR 5221, CNRS and Université Montpellier 2, Montpellier (France)


    Ultrastable glasses have risen to prominence due to their potentially useful material properties and the tantalizing possibility of a general method of preparation via vapor deposition. Despite the importance of this novel class of amorphous materials, numerical studies have been scarce because achieving ultrastability in atomistic simulations is an enormous challenge. Here, we bypass this difficulty and establish that randomly pinning the position of a small fraction of particles inside an equilibrated supercooled liquid generates ultrastable configurations at essentially no numerical cost, while avoiding undesired structural changes due to the preparation protocol. Building on the analogy with vapor-deposited ultrastable glasses, we study the melting kinetics of these configurations following a sudden temperature jump into the liquid phase. In homogeneous geometries, we find that enhanced kinetic stability is accompanied by large scale dynamic heterogeneity, while a competition between homogeneous and heterogeneous melting is observed when a liquid boundary invades the glass at constant velocity. Our work demonstrates the feasibility of large-scale, atomistically resolved, and experimentally relevant simulations of the kinetics of ultrastable glasses.

  8. The Half-Pin and the Pin Tract: A Survey of the Limb Lengthening and Reconstruction Society (United States)


    differences in technique being predrilling or no predrilling before half-pin placement and placement of the half-pin by hand or by power . Much of...daily, weekly) and procedure (eg, specific cleansing so- lution).7,9,10 Treatment ranges from use of parenteral or oral antibiotics to pin removal or...antibiotics were prescribed more  often (83%) than  parenteral  antibiotics (17%)  and were given for 8 days on average. Results from this study helped

  9. Magnetic vortices as localized mesoscopic domain wall pinning sites (United States)

    Novak, R. L.; Sampaio, L. C.


    We report on the controllable pinning of domain walls in a stripe with perpendicular magnetic anisotropy by magnetostatic coupling to a magnetic vortex in disks located above the stripe. Pinning mechanisms and depinning fields, studied by means of micromagnetic simulations, are reported. An asymmetric magnetization reversal process is observed and explained in terms of two main contributions to the domain wall pinning: coupling between the in-plane and out-of-plane components of its stray field and the vortex. The in-plane coupling is symmetric with respect to the wall sense of motion while the out-of-plane coupling leads to the observed asymmetry in the hysteresis loops. The energy landscape of the domain wall derived from the micromagnetic simulations supports these findings. This novel pinning strategy, which can be realized by current nanofabrication techniques, opens up new possibilities for the non-destructive control of domain wall mobility in domain wall based spintronic devices.

  10. Critical currents in quasiperiodic pinning arrays: chains and Penrose lattices. (United States)

    Misko, Vyacheslav; Savel'ev, Sergey; Nori, Franco


    We study the critical depinning current Jc versus the applied magnetic flux Phi, for quasiperiodic (QP) chains and 2D arrays of pinning centers placed on the nodes of a fivefold Penrose lattice. In QP chains, the peaks in Jc(Phi) are determined by a sequence of harmonics of the long and short segments of the chain. The critical current Jc(Phi) has a remarkable self-similarity. In 2D QP pinning arrays, we predict analytically and numerically the main features of Jc(Phi), and demonstrate that the Penrose lattice of pinning sites provides an enormous enhancement of Jc(Phi), even compared to triangular and random pinning site arrays. This huge increase in Jc(Phi) could be useful for applications.

  11. PIN architecture for ultrasensitive organic thin film photoconductors. (United States)

    Jin, Zhiwen; Wang, Jizheng


    Organic thin film photoconductors (OTFPs) are expected to have wide applications in the field of optical communications, artificial vision and biomedical sensing due to their great advantages of high flexibility and low-cost large-area fabrication. However, their performances are not satisfactory at present: the value of responsivity (R), the parameter that measures the sensitivity of a photoconductor to light, is below 1 AW(-1). We believe such poor performance is resulted from an intrinsic self-limited effect of present bare blend based device structure. Here we designed a PIN architecture for OTFPs, the PIN device exhibits a significantly improved high R value of 96.5 AW(-1). The PIN architecture and the performance the PIN device shows here should represent an important step in the development of OTFPs.

  12. PIN architecture for ultrasensitive organic thin film photoconductors (United States)

    Jin, Zhiwen; Wang, Jizheng


    Organic thin film photoconductors (OTFPs) are expected to have wide applications in the field of optical communications, artificial vision and biomedical sensing due to their great advantages of high flexibility and low-cost large-area fabrication. However, their performances are not satisfactory at present: the value of responsivity (R), the parameter that measures the sensitivity of a photoconductor to light, is below 1 AW−1. We believe such poor performance is resulted from an intrinsic self-limited effect of present bare blend based device structure. Here we designed a PIN architecture for OTFPs, the PIN device exhibits a significantly improved high R value of 96.5 AW−1. The PIN architecture and the performance the PIN device shows here should represent an important step in the development of OTFPs. PMID:24936952

  13. Stroboscopic phenomena in superconductors with dynamic pinning landscape

    National Research Council Canada - National Science Library

    Jelić, Ž L; Milošević, M V; Van de Vondel, J; Silhanek, A V


    Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain without dissipation...

  14. Cytokinin response factors regulate PIN-FORMED auxin transporters. (United States)

    Šimášková, Mária; O'Brien, José Antonio; Khan, Mamoona; Van Noorden, Giel; Ötvös, Krisztina; Vieten, Anne; De Clercq, Inge; Van Haperen, Johanna Maria Adriana; Cuesta, Candela; Hoyerová, Klára; Vanneste, Steffen; Marhavý, Peter; Wabnik, Krzysztof; Van Breusegem, Frank; Nowack, Moritz; Murphy, Angus; Friml, Jiří; Weijers, Dolf; Beeckman, Tom; Benková, Eva


    Auxin and cytokinin are key endogenous regulators of plant development. Although cytokinin-mediated modulation of auxin distribution is a developmentally crucial hormonal interaction, its molecular basis is largely unknown. Here we show a direct regulatory link between cytokinin signalling and the auxin transport machinery uncovering a mechanistic framework for cytokinin-auxin cross-talk. We show that the CYTOKININ RESPONSE FACTORS (CRFs), transcription factors downstream of cytokinin perception, transcriptionally control genes encoding PIN-FORMED (PIN) auxin transporters at a specific PIN CYTOKININ RESPONSE ELEMENT (PCRE) domain. Removal of this cis-regulatory element effectively uncouples PIN transcription from the CRF-mediated cytokinin regulation and attenuates plant cytokinin sensitivity. We propose that CRFs represent a missing cross-talk component that fine-tunes auxin transport capacity downstream of cytokinin signalling to control plant development.

  15. Fracture Analysis of 40Cr Steel Pin Roll (United States)

    Li, Yong; Jia, Youlu; Xie, Xianjiao


    Fracture of 40Cr steel pin roll happened along the cross-section at the spot of filling aperture. By the use of analysis of optical microscopy and microhardness, it can be known that filling aperture and its nitration case (ε phase) and large amounts of non-metal inclusions (bulk obscure inclusions) in steel were the main reasons which led to the facture of 40Cr steel pin roll.

  16. AtPIN: Arabidopsis thaliana Protein Interaction Network

    Directory of Open Access Journals (Sweden)

    Silva-Filho Marcio C


    Full Text Available Abstract Background Protein-protein interactions (PPIs constitute one of the most crucial conditions to sustain life in living organisms. To study PPI in Arabidopsis thaliana we have developed AtPIN, a database and web interface for searching and building interaction networks based on publicly available protein-protein interaction datasets. Description All interactions were divided into experimentally demonstrated or predicted. The PPIs in the AtPIN database present a cellular compartment classification (C3 which divides the PPI into 4 classes according to its interaction evidence and subcellular localization. It has been shown in the literature that a pair of genuine interacting proteins are generally expected to have a common cellular role and proteins that have common interaction partners have a high chance of sharing a common function. In AtPIN, due to its integrative profile, the reliability index for a reported PPI can be postulated in terms of the proportion of interaction partners that two proteins have in common. For this, we implement the Functional Similarity Weight (FSW calculation for all first level interactions present in AtPIN database. In order to identify target proteins of cytosolic glutamyl-tRNA synthetase (Cyt-gluRS (AT5G26710 we combined two approaches, AtPIN search and yeast two-hybrid screening. Interestingly, the proteins glutamine synthetase (AT5G35630, a disease resistance protein (AT3G50950 and a zinc finger protein (AT5G24930, which has been predicted as target proteins for Cyt-gluRS by AtPIN, were also detected in the experimental screening. Conclusions AtPIN is a friendly and easy-to-use tool that aggregates information on Arabidopsis thaliana PPIs, ontology, and sub-cellular localization, and might be a useful and reliable strategy to map protein-protein interactions in Arabidopsis. AtPIN can be accessed at

  17. Pin Worm Survey on Infant School Children in Gunma Prefecture


    佐藤, 久美子; 阿部, 美幸; 伊藤, 恵美; 金田, 聡子; 関口, 直美; 深町, 容子; 松渕, ユカ子; 柳, 博美; 鈴木, 守


    Pin worms (Enterobius vermicularis) are the commonest intestinal parasite in Japan. Examination of this worm infection is usually made by microscopic observation on the swab taken on a scothch tape. We conducted a survey of pin worm infection among infant school children of 4-6 years old. Suitable days for swab examination were studied by comparing the detection rate according to the consecutive days tested. Results were summarized as follows: 1. Three hundred sixteen children (172 boys and 1...

  18. Dipentamethylene thiuram monosulfide is a novel inhibitor of Pin1

    Energy Technology Data Exchange (ETDEWEB)

    Tatara, Yota; Lin, Yi-Chin; Bamba, Yoshimasa; Mori, Tadashi [Molecular Enzymology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 1-1 Amamiya, Tsutsumidori, Aoba, Sendai, Miyagi 981-8555 (Japan); Uchida, Takafumi, E-mail: [Molecular Enzymology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 1-1 Amamiya, Tsutsumidori, Aoba, Sendai, Miyagi 981-8555 (Japan)


    Pin1 is involved in eukaryotic cell proliferation by changing the structure and function of phosphorylated proteins. PiB, the Pin1 specific inhibitor, blocks cancer cell proliferation. However, low solubility of PiB in DMSO has limited studies of its effectiveness. We screened for additional Pin1 inhibitors and identified the DMSO-soluble compound dipentamethylene thiuram monosulfide (DTM) that inhibits Pin1 activity with an EC50 value of 4.1 {mu}M. Molecular modeling and enzyme kinetic analysis indicated that DTM competitively inhibits Pin1 activity, with a K{sub i} value of 0.05 {mu}M. The K{sub D} value of DTM with Pin1 was determined to be 0.06 {mu}M by SPR technology. Moreover, DTM specifically inhibited peptidyl-prolyl cis/trans isomerase activity in HeLa cells. FACS analysis showed that DTM induced G0 arrest of the HCT116 cells. Our results suggest that DTM has the potential to guide the development of novel antifungal and/or anticancer drugs.

  19. Mechanisms of Soldering Formation on Coated Core Pins (United States)

    Song, Jie; Denouden, Tony; Han, Qingyou


    Die soldering is one of the major casting defects during the high-pressure die casting (HPDC) process, causing dimensional inaccuracy of the castings and increased downtimes of the HPDC machine. In this study, we analyzed actually failed core pins to determine the mechanism of soldering and its procedures. The results show that the soldering process starts from a local coating failure, involves a series of intermetallic phase formation from reactions between molten aluminum alloys and the H13 steel pin, and accelerates when an aluminum-rich, face-centered cubic (fcc) phase is formed between the intermetallic phases. It is the formation of the aluminum-rich fcc phase in the reaction region that joins the core pin with the casting, resulting in the sticking of the casting to the core pin. When undercuts are formed on the core pin, the ejection of castings from the die will lead to either a core pin failure or damages to the casting being ejected.

  20. A survey of Populus PIN-FORMED family genes reveals their diversified expression patterns. (United States)

    Liu, Bobin; Zhang, Jin; Wang, Lin; Li, Jianbo; Zheng, Huanquan; Chen, Jun; Lu, Mengzhu


    The plant hormone auxin is a key regulator of plant development, and its uneven distribution maintained by polar intercellular auxin transport in plant tissues can trigger a wide range of developmental processes. Although the roles of PIN-FORMED (PIN) proteins in intercellular auxin flow have been extensively characterized in Arabidopsis, their roles in woody plants remain unclear. Here, a comprehensive analysis of PIN proteins in Populus is presented. Fifteen PINs are encoded in the genome of Populus, including four PIN1s, one PIN2, two PIN3s, three PIN5s, three PIN6s, and two PIN8s. Similar to Arabidopsis AtPIN proteins, PtPINs share conserved topology and transmembrane domains, and are either plasma membrane- or endoplasmic reticulum-localized. The more diversified expansion of the PIN family in Populus, comparing to that in Arabidopsis, indicates that some auxin-regulated developmental processes, such as secondary growth, may exhibit unique features in trees. More importantly, different sets of PtoPINs have been found to be strongly expressed in the roots, leaves, and cambium in Populus; the dynamic expression patterns of selected PtoPINs were further examined during the regeneration of shoots and roots. This genome-wide analysis of the Populus PIN family provides important cues for their potential roles in tree growth and development. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email:

  1. The role of weak intermolecular CH… F interactions in ...

    Indian Academy of Sciences (India)

    Analysis of Cambridge Structural Database using these newly defined parameters reveals high propensity of C-H…F interactions in organic crystals. The present structural study suggests much larger role of fluorine driven intermolecular interactions that are even though weak, but possess significant ability to direct and alter ...

  2. Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection in a goat model.

    Energy Technology Data Exchange (ETDEWEB)

    Dejong, E. Schuyler; Deberardino, T. M.; Brooks, D. E.; Nelson, B. J.; Campbell, Allison A.; Bottoni, Craig R.; Pusateri, A. E.; Walton, R. S.; Guymon, C. H.; Mcmanus, Albert T.


    Background: Pin tract infection is a common complication of external fixation. An antiinfective external fixator pin might help to reduce the incidence of pin tract infection and improve pin fixation. Methods: Stainless steel and titanium external fixator pins, with and without a lipid stabilized hydroxyapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites were examined daily. On day 14, the animals were killed, and the pin tips cultured. Insertion and extraction torques were measured. Results: Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation torque over uncoated pins (p = 0.04). Conclusion: These results demonstrate that the lipid stabilized hydroxyapatite/chlorhexidine coating was successful in decreasing infection and improving fixation of external fixator pins.

  3. Repeat biopsy in patients with initial diagnosis of PIN; La biopsia ripetuta nei pazienti con diagnosi iniziale di PIN

    Energy Technology Data Exchange (ETDEWEB)

    De Matteis, Massimo [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Radiologia Albertoni; Poggi, Cristina; De Martino, Antonietta; Pavlica, Pietro [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Radiologia Palagi, Dipartimento area radiologica; Corti, Barbara [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Anatomia ed istologia patologica, Dipartimento oncologico ed ematologico; Barozzi, Libero [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Radiologia d' urgenza, Dipartimento emergenze ed accettazione


    Purpose. Prostatic intra-epithelial neoplasia (PIN) is considered a pre-malignant lesion and the main precursor of invasive prostatic adenocarcinoma. A PIN diagnosis established by prostate needle biopsy poses a difficult clinical management. problem. We retrospectively reviewed our three-year experience in order to identify criteria for referring patients to repeat biopsy. Materials and methods. We reviewed the repeat biopsy records of 72 patients in whom PIN had been detected on initial US-guided needle biopsy of the prostate. All the patients had a minimum of 6 biopsy cores taken, and they all had PSA > 4 ng/ml. Results. Adenocarcinoma was detected in 15 patients out of 50 (30%) with an initial diagnosis of low-grade PIN and in 10 patients out of 22 (45.4%) with high grade PIN, in 7 out of 18 (39%) in whom PSA levels had decreased during the observation interval, in 16 patients out of 46 (35%) in whom the PSA had increased and in 2 patients out of 8 (25%) with stable PSA. Conclusions. Our results seem to confirm that PIN can be considered a precursor of prostatic adenocarcinoma or a histological alteration often associated with it. Patients with low-grade PIN and particularly those with high-grade PIN should be regularly subjected to repeat biopsy at short intervals due to the high frequency of the final diagnosis of carcinoma. No agreement has been reached on the time interval between the first and the second biopsy. The PSA changes during the observation period are not a statistically significant parameter to suggest the repetition of prostatic biopsy. [Italian] Scopo. La neoplasia prostatica intraepiteliale (PIN) e considerata una lesione premaligna ed il precursore principale dell'adenocarcinoma prostatico infiltrante. La diagnosi di PIN ottenuta con l'agobiopsia della prostata rappresenta un difficile problema gestionale clinico. In una valutazione retrospettiva della nostra esperienza di 3 anni si e cercato di individuare i criteri che possano

  4. Interplay between collective pinning and artificial defects on domain wall propagation in Co/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Rodriguez, G; Hierro-Rodriguez, A; Perez-Junquera, A; Montenegro, N; Alameda, J M; Velez, M [Dept. Fisica, Universidad de Oviedo-CINN, 33007 Oviedo (Spain); Menendez, J L [Centro de Investigacion en Nanomateriales y Nanotecnologia (CINN). Principado de Asturias-Consejo Superior de Investigaciones Cientificas (CSIC)-Univ. Oviedo -UO, Parque Tecnologico de Asturias, 33428 Llanera (Spain); Ravelosona, D, E-mail: mvelez@uniovi.e [Institut d' Electronique Fondamentale, UMR CNRS 8622, Univ. Paris Sud, 91405 Orsay Cedex (France)


    The interplay between collective pinning on intrinsic structural defects and artificial pinning at a patterned hole is studied in magnetic multilayers with perpendicular anisotropy. The pinning strength of a patterned hole is measured through its efficiency to stop domain wall (DW) propagation into a consecutive unpatterned nanowire section (using antisymmetric magnetoresistance to detect the direction of DW propagation) whereas collective pinning is characterized by the field dependence of DW velocity. Close to room temperature, collective pinning becomes weaker than artificial pinning so that pinning at the hole compensates nucleation-pad geometry, blocking DW propagation across the nanowire.

  5. Silver(I) complexes of the weakly coordinating solvents SO(2) and CH(2)Cl(2): crystal structures, bonding, and energetics of [Ag(OSO)][Al{OC(CF(3))(3)}(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(CH(2)Cl(2))(2)][SbF(6)]. (United States)

    Decken, Andreas; Knapp, Carsten; Nikiforov, Grigori B; Passmore, Jack; Rautiainen, J Mikko; Wang, Xinping; Zeng, Xiaoqing


    Pushing the limits of coordination chemistry: The most weakly coordinated silver complexes of the very weakly coordinating solvents dichloromethane and liquid sulfur dioxide were prepared. Special techniques at low temperatures and the use of weakly coordinating anions allowed structural characterization of [Ag(OSO)][Al{OC(CF(3))(3)}(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(Cl(2)CH(2))(2)][SbF(6)] (see figure). An investigation of the bonding shows that these complexes are mainly stabilized by electrostatic monopole-dipole interactions.The synthetically useful solvent-free silver(I) salt Ag[Al(pftb)(4)] (pftb=--OC(CF(3))(3)) was prepared by metathesis reaction of Li[Al(pftb)(4)] with Ag[SbF(6)] in liquid SO(2). The solvated complexes [Ag(OSO)][Al(pftb)(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(CH(2)Cl(2))(2)][SbF(6)] were prepared and isolated by special techniques at low temperatures and structurally characterized by single-crystal X-ray diffraction. The SO(2) complexes provide the first examples of coordination of the very weak Lewis base SO(2) to silver(I). The SO(2) molecule in [Ag(OSO)][Al(pftb)(4)] is eta(1)-O coordinated to Ag(+), while the SO(2) ligands in [Ag(OSO)(2/2)][SbF(6)] bridge two Ag(+) ions in an eta(2)-O,O' (trans,trans) manner. [Ag(CH(2)Cl(2))(2)][SbF(6)] contains [Ag(CH(2)Cl(2))(2)](+) ions linked through [SbF(6)](-) ions to give a polymeric structure. The solid-state silver(I) ion affinities (SIA) of SO(2) and CH(2)Cl(2), based on bond lengths and corresponding valence units in the corresponding complexes and tensimetric titrations of Ag[Al(pftb)(4)] and Ag[SbF(6)] with SO(2) vapor, show that SO(2) is a weaker ligand to Ag(+) than the commonly used weakly coordinating solvent CH(2)Cl(2) and indicated that binding strength of SO(2) to silver(I) in the silver(I) salts increases with increasing size of the corresponding counteranion ([Al(pftb)(4)](-)>[SbF(6)](-)). The experimental findings are in good agreement with theoretical gas-phase ligand

  6. Role of the Arabidopsis PIN6 Auxin Transporter in Auxin Homeostasis and Auxin-Mediated Development


    Cazzonelli, Christopher I.; Marleen Vanstraelen; Sibu Simon; Kuide Yin; Ashley Carron-Arthur; Nazia Nisar; Gauri Tarle; Cuttriss, Abby J.; Searle, Iain R.; Eva Benkova; Ulrike Mathesius; Josette Masle; Jiří Friml; Pogson, Barry J.


    Plant-specific PIN-formed (PIN) efflux transporters for the plant hormone auxin are required for tissue-specific directional auxin transport and cellular auxin homeostasis. The Arabidopsis PIN protein family has been shown to play important roles in developmental processes such as embryogenesis, organogenesis, vascular tissue differentiation, root meristem patterning and tropic growth. Here we analyzed roles of the less characterised Arabidopsis PIN6 auxin transporter. PIN6 is auxin-inducible...

  7. Flux pinning and Critical current density in La2-xSrxCuO4+d (United States)

    Mohottala, Hashini; Wells, B. O.; Budnick, J. I.; Hines, W. A.; Moodenbaugh, A. R.; Chou, F. C.


    We have studied the magnetic characteristics of the critical states in a series of samples of the type La2-xSrxCuO4+d that is doped with both Sr and excess O incorporated using electrochemistry. These samples spontaneously phase separate and show both a superconducting phase with TC near 40 K and a magnetic phase with TM near 40 K. Our previous studies established that the superconducting phase is similar to an optimally doped sample while the magnetic phase is consistent with the static spin density wave reported for x=1/8 Sr or Ba doped samples. Magnetization data at various temperatures showed large reversibility in all the samples. The critical current densities JC(0) values were at least an order of magnitude smaller than that of the reported values for YBa2Cu3O7-d and La2-xSrxCuO4. At higher fields JC(H) was smaller indicating the existence of weak flux pinning in the system. Based on our magnetization data we conclude that the vortex lattice pinning is different from non-phase separated cuprates. This work was partially supported by the US-DOE through contract DE-FG02-00ER45801 and the Cottrell Scholar Program of the Research Corporation.

  8. Weak Measurement and Quantum Correlation

    Indian Academy of Sciences (India)

    Arun Kumar Pati

    The concept of the weak measurements, for the first time, was introduced by Aharonov et al.1. Quantum state is preselected in |ψi〉 and allowed to interact weakly with apparatus. Measurement strength can be tuned and for “small g(t)” it is called 'weak measurement'. With postselection in |ψf 〉, apparatus state is shifted by an ...

  9. Influence of Titanium on Crystallization and Wear Resistance of High Chromium Cast Iron

    Directory of Open Access Journals (Sweden)

    Studnicki A.


    Full Text Available Paper presents the results of studies on primary crystallization and wear resistance of high chromium cast iron inoculated with ferrotitanium intended for work in abrasive conditions. Primary crystallization was examined with use of TDA method, wear tests of the samples were conducted using the modified pin-on-disk method.

  10. Influence of Titanium on Crystallization and Wear Resistance of High Chromium Cast Iron


    Studnicki A.; Dojka R.; Gromczyk M.; Kondracki M.


    Paper presents the results of studies on primary crystallization and wear resistance of high chromium cast iron inoculated with ferrotitanium intended for work in abrasive conditions. Primary crystallization was examined with use of TDA method, wear tests of the samples were conducted using the modified pin-on-disk method.

  11. Alpha particles spectrometer with photodiode PIN; Espectrometro de particulas alfa con fotodiodo PIN

    Energy Technology Data Exchange (ETDEWEB)

    Chacon R, A.; Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidades Academicas de Estudios Nucleares e Ingenieria Electrica, Calle Cipres No. 10, Fracc. La Penuela, 09869 Zacatecas (Mexico); Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Direccion General de Innovacion y Tecnologia de Informacion, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico)], e-mail:


    The radiation propagates in form of electromagnetic waves or corpuscular radiation; if the radiation energy causes ionization in environment that crosses it is considered ionizing radiation. To detect radiation several detectors types are used, if the radiation are alpha particles are used detectors proportional type or trace elements. In this work the design results, construction and tests of an alpha particles spectrometer are presented, which was designed starting from a photodiode PIN type. The system design was simulated with a code for electronic circuits. With results of simulation phase was constructed the electronic phase that is coupled to a multichannel analyzer. The resulting electronic is evaluated analyzing the electronic circuit performance before an alphas triple source and alpha radiation that produce two smoke detectors of domestic use. On the tests phase we find that the system allows obtain, in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

  12. The two-dimensional vibrating reed technique. A study of anisotropic pinning in high-temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Karelina, Anna


    In this work the anisotropy of the pinning forces of vortices in a-b plane of high temperature-supraconductors was examined. For this purpose vibrating reed with two degrees of freedom of the oscillation was constructed. The pinning forces were examined in single crystals of YBa{sub 2}Cu{sub 3}O{sub 7} and Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}. The experiments with YBa{sub 2}Cu{sub 3}O{sub 7} show that at temperatures lower than 78 K the vortices are in a nonequilibrium state. This leads to a flux creep and to a drift of the resonance frequency with time. This prevents the comparison of resonance curves in different directions of oscillations. In Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} single crystals the vortices are in more stable state, but the measurements of the resonance curves in different directions show no indication of the four-fold symmetry. At temperatures below 60 K a strong hysteresis of the resonance frequency and the resonance-oscillation amplitude was found in YBa{sub 2}Cu{sub 3}O{sub 7} crystals as a function of the magnetic field. (orig.)

  13. Silicide Schottky Contacts to Silicon: Screened Pinning at Defect Levels

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, T.J.


    Silicide Schottky contacts can be as large as 0.955 eV (E{sub v} + 0.165 eV) on n-type silicon and as large as 1.05 eV (E{sub c} {minus} 0.07 eV) on p-type silicon. Current models of Schottky barrier formation do not provide a satisfactory explanation of occurrence of this wide variation. A model for understanding Schottky contacts via screened pinning at defect levels is presented. In the present paper it is shown that most transition metal silicides are pinned approximately 0.48 eV above the valence band by interstitial Si clusters. Rare earth disilicides pin close to the divacancy acceptor level 0.41 eV below the conduction band edge while high work function silicides of Ir and Pt pin close to the divacancy donor level 0.21 eV above the valence band edge. Selection of a particular defect pinning level depends strongly on the relative positions of the silicide work function and the defect energy level on an absolute energy scale.

  14. Performance of electrical contact pins near a nuclear explosion

    Energy Technology Data Exchange (ETDEWEB)

    Ragan, C.E.; Silbert, M.G.; Ellis, A.N.; Robinson, E.E.; Daddario, M.J.


    The pressures attainable in equation-of-state studies using nuclear-explosion-driven shock waves greatly exceed those that can be reached in normal laboratory conditions. However, the diagnostic instrumentation must survive in the high-radiation environment present near such an explosion. Therefore, a set of experiments were fielded on the Redmud event to test the feasibility of using electrical contact pins in this environment. In these experiments a 60-cm-high shield of boron-lead was placed on the rack lid approximately 1 m from the device. A sample consisting of slabs of molybdenum and /sup 238/U was placed on top of the shield, and twelve electrical contact pins were embedded to five different depths in the materials. Five different multiplexing-charging circuits were used for the pins, and a piezoelectric quartz gauge was placed on top of the uranium to obtain an estimate of the fission-energy deposition. All of the charged pins survived the radiation and produced signals indicating shock arrival. The uncertainty in determining the pin-closure time was approximately 3 ns. The signal from the quartz gauge corresponded to a pressure that was consistent with the calculated neutron fluence.

  15. Pin1 and neurodegeneration: a new player for prion disorders?

    Directory of Open Access Journals (Sweden)

    Elisa Isopi


    Full Text Available Pin1 is a peptidyl-prolyl isomerase that catalyzes the cis/trans conversion of phosphorylated proteins at serine or threonine residues which precede a proline. The peptidyl-prolyl isomerization induces a conformational change of the proteins involved in cell signaling process. Pin1 dysregulation has been associated with some neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Proline-directed phosphorylation is a common regulator of these pathologies and a recent work showed that it is also involved in prion disorders. In fact, prion protein phosphorylation at the Ser-43-Pro motif induces prion protein conversion into a disease-associated form. Furthermore, phosphorylation at Ser-43-Pro has been observed to increase in the cerebral spinal fluid of sporadic Creutzfeldt-Jakob Disease patients. These findings provide new insights into the pathogenesis of prion disorders, suggesting Pin1 as a potential new player in the disease. In this paper, we review the mechanisms underlying Pin1 involvement in the aforementioned neurodegenerative pathologies focusing on the potential role of Pin1 in prion disorders.

  16. Treatment of unstable distal clavicle fractures with Knowles pin. (United States)

    Jou, I-Ming; Chiang, Eric P; Lin, Chii-Jen; Lin, Cheng-Li; Wang, Ping-Hui; Su, Wei-Ren


    Unstable distal clavicle fractures often need surgical treatment. This report describes a new intramedullary extra-articular Knowles pin fixation method to treat these unstable fractures. Twelve patients with unstable distal clavicle fractures (Neer type II) had surgery with intramedullary extra-articular Knowles pin fixation. We retrospectively reviewed clinical results for pain, shoulder function, and range of motion, as well as radiographic results, for this institutional review board-approved study. Each patient's operated arm was in a sling for 4 weeks postoperatively. The University of California, Los Angeles shoulder rating scale score was used to evaluate shoulder function. All patients showed radiographically confirmed bony union. The mean period required for healing was 11.5 weeks, and patients were followed up for 6 to 24 months (mean, 15.2 months), during which University of California, Los Angeles scores (mean, 33.9) indicated good clinical results. Three patients had the complication of proximal or distal skin irritation caused by the thread and hub of the Knowles pin. The Knowles pin fixation method is useful for treating unstable distal clavicle fractures. However, sufficient familiarity with the technique and careful preoperative planning to determine the appropriate length of the pin are necessary to prevent complications and to effect a high union rate. Copyright © 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  17. Axion crystals (United States)

    Ozaki, Sho; Yamamoto, Naoki


    The low-energy effective theories for gapped insulators are classified by three parameters: permittivity ɛ, permeability μ, and theta angle θ. Crystals with periodic ɛ are known as photonic crystals. We here study the band structure of photons in a new type of crystals with periodic θ (modulo 2 π) in space, which we call the axion crystals. We find that the axion crystals have a number of new properties that the usual photonic crystals do not possess, such as the helicity-dependent mass gap and nonrelativistic gapless dispersion relation at small momentum. We briefly discuss possible realizations of axion crystals in condensed matter systems and high-energy physics.

  18. Space group constraints on weak indices in topological insulators (United States)

    Varjas, Dániel; de Juan, Fernando; Lu, Yuan-Ming


    Lattice translation symmetry gives rise to a large class of "weak" topological insulators (TIs), characterized by translation-protected gapless surface states and dislocation bound states. In this work we show that space group symmetries lead to constraints on the weak topological indices that define these phases. In particular, we show that screw rotation symmetry enforces the Hall conductivity in planes perpendicular to the screw axis to be quantized in multiples of the screw rank, which generally applies to interacting systems. We further show that certain 3D weak indices associated with quantum spin Hall effects (class AII) are forbidden by the Bravais lattice and by glide or even-fold screw symmetries. These results put strong constraints on weak TI candidates in the experimental and numerical search for topological materials, based on the crystal structure alone.

  19. Pin Tool Geometry Effects in Friction Stir Welding (United States)

    Querin, J. A.; Rubisoff, H. A.; Schneider, J. A.


    In friction stir welding (FSW) there is significant evidence that material can take one of two different flow paths when being displaced from its original position in front of the pin tool to its final position in the wake of the weld. The geometry of the pin tool, along with the process parameters, plays an important role in dictating the path that the material takes. Each flow path will impart a different thermomechanical history on the material, consequently altering the material microstructure and subsequent weld properties. The intention of this research is to isolate the effect that different pin tool attributes have on the flow paths imparted on the FSWed material. Based on published weld tool geometries, a variety of weld tools were fabricated and used to join AA2219. Results from the tensile properties and microstructural characterization will be presented.

  20. Ordered Pinning Arrays with Tunable Geometry via Thermal Effects (United States)

    Trastoy, Juan; Bernard, Rozenn; Briatico, Javier; Villegas, Javier E.; Malnou, Maxime; Bergeal, Nicolas; Lesueur, Jerome; Ulysse, Christian; Faini, Giancarlo


    We have used geometrically frustrated pinning arrays to create artificial vortex-ice. The pinning arrays are fabricated via ion irradiation of high-Tc superconducting films. These arrays present a very unique characteristic: the frustration can be reversibly switched on/off using temperature as a control knob, which allows stabilizing either a vortex-ice or a square vortex lattice. We have further investigated the thermal switching mechanism by studying the matching of the flux lattice to arrays that are incrementally deformed upon fabrication by introducing minute variations of the distance between pins. The array deformation exacerbates the thermal effects, leading to dramatic variations of the vortex distribution as a function of temperature. These results illustrate the strength of the temperature-induced reconfiguration effects, which may constitute a novel knob in fluxtronic devices based on vortex manipulation. Work supported by the French ANR MASTHER, the COST Action NanoSC, the Ville de Paris and the Galician Fundacion Barrie.

  1. Improved interface growth and enhanced flux pinning in YBCO films deposited on an advanced IBAD-MgO based template (United States)

    Khan, M. Z.; Zhao, Y.; Wu, X.; Malmivirta, M.; Huhtinen, H.; Paturi, P.


    The growth mechanism is studied from the flux pinning point of view in small-scale YBa2Cu3O6+x (YBCO) thin films deposited on a polycrystalline hastelloy with advanced IBAD-MgO based buffer layer architecture. When compared the situation with YBCO films grown on single crystal substrates, the most critical issues that affect the suitable defect formation and thus the optimal vortex pinning landscape, have been studied as a function of the growth temperature and the film thickness evolution. We can conclude that the best critical current property in a wide applied magnetic field range is observed in films grown at relatively low temperature and having intermediate thickness. These phenomena are linked to the combination of the improved interface growth, to the film thickness related crystalline relaxation and to the formation of linear array of edge dislocations that forms the low-angle grain boundaries through the entire film thickness and thus improve the vortex pinning properties. Hence, the optimized buffer layer structure proved to be particularly suitable for new coated conductor solutions.

  2. Phase-field-crystal model for ordered crystals. (United States)

    Alster, Eli; Elder, K R; Hoyt, Jeffrey J; Voorhees, Peter W


    We describe a general method to model multicomponent ordered crystals using the phase-field-crystal (PFC) formalism. As a test case, a generic B2 compound is investigated. We are able to produce a line of either first-order or second-order order-disorder phase transitions, features that have not been incorporated in existing PFC approaches. Further, it is found that the only elastic constant for B2 that depends on ordering is C_{11}. This B2 model is then used to study antiphase boundaries (APBs). The APBs are shown to reproduce classical mean-field results. Dynamical simulations of ordering across small-angle grain boundaries predict that dislocation cores pin the evolution of APBs.

  3. Sessile droplet de-pinning: new life for gravimetric data. (United States)

    Chan, Kwaichow B; Pierce, Scott M


    Using three different types of surfaces as exemplars, we report a gravimetric method as a viable tool for studying the de-pinning process. Namely, the de-pin time, tau(d) (the time required for a horizontal sessile droplet to de-pin at the triple phase line on a given substrate), is estimated without using a time consuming and expensive video imaging system. This is made possible by deciphering the non-linear portion of mass vs time data of an evaporating sessile droplet. Typical gravimetric glass-substrate evaporative mass loss vs time data has two regimes: a long, linear regime followed by a short, non-linear regime. Traditionally, researchers extract only the evaporation rate of a droplet from the linear regime but discard (by truncating the data) or ignore (thus deriving no information from) the non-linear regime. The origin of the linear to non-linear transition, found almost universally in gravimetric data, persists unremarked upon. By constructing three very different types of surfaces and comparing gravimetric data with video imaging data taken simultaneously, we report the transition is correlated to the onset of the de-pinning event in each case. This realization enables us to measure the de-pin time, tau(d), with gravimetric data only; i.e., without the video system, gathering more information from gravimetric data than previously considered. The method has application in estimating the de-pin time of a droplet deposited on a substrate that yields poor top-view contrast for videography, such as a water droplets on silicon wafers or glass substrates. Finally, gravimetric data is more accurate for evaporation modeling when substrate/droplet interaction areas are not circular.

  4. 8 Pin RIC Socket for Hearing Aid Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Davids, Søren


    The current paper presents the development of an 8 Pin RIC (Receiver in the canal) Socket for hearing instruments within the framework of the COTECH project. There are 8 industrial demonstrators developed in COTECH based on the converged product and process design. Sonion’s 8 Pin RIC Socket is one......-automated process and the other one is fully automated process. This paper presents the entire process chain for both the concepts and makes a comparative analysis based on the experimental investigation and validation. The work presented here can be a source of valuable information for industrial users...... and researchers working with micro production of metal-plastic hybrid components....

  5. Critical Currents in Quasiperiodic Pinning Arrays: Chains and Penrose Lattices


    Misko, V. R.; Savel'ev, Sergey; Nori, Franco


    We study the critical depinning current Jc versus the applied magnetic flux Phi, for quasiperiodic (QP) chains and 2D arrays of pinning centers placed on the nodes of a five-fold Penrose lattice. In QP chains, the peaks in Jc(Phi) are determined by a sequence of harmonics of the long and short segments of the chain. The critical current Jc(Phi) has a remarkable self-similarity. In 2D QP pinning arrays, we predict analytically and numerically the main features of Jc(Phi), and demonstrate that ...

  6. Dosimetric characteristics of a PIN diode for radiotherapy application. (United States)

    Kumar, R; Sharma, S D; Philomina, A; Topkar, A


    The PIN diode developed by Bhabha Atomic Research Centre (BARC) was modified for its use as a dosimeter in radiation therapy. For this purpose the diode was mounted on a printed circuit board (PCB) and provided with necessary connections so that its response against irradiation can be recorded by a standard radiotherapy electrometer. The dosimetric characteristics of the diode were studied in Co-60 gamma rays as well as high energy X-rays. The measured sensitivity of this PIN diode is 4 nC/cGy which is about ten times higher than some commercial diode dosimeters. The leakage current from the diode is 0.04 nA. The response of the PIN diode is linear in the range of 20-1000 cGy which covers the full range of radiation dose encountered in radiotherapy treatments. The non-linearity of the diode response is 3.5% at 20 cGy and it is less than 1.5% at higher dose values. Its repeatability is within 0.5%. The angular response variation is about 5.6% within 6608 with respect to normal beam incidence. The response of the PIN diode at 6 and 18 MV X-rays varies within 2% with respect to its response at Co-60 gamma rays. The source to surface distance (SSD) dependence of the PIN diode was studied for Co-60 beam. It was found that the response of the diode decreases almost linearly relative to given dose for beams with constant collimator setting but increasing SSD (decreasing dose-rate). Within this study the diode response varied by about 2.5% between the maximum and minimum SSD. The dose-rate dependence of the PIN diode for 6 and 15 MV-rays was studied. The variation in response of diode for both energies in the studied dose range is less than 1%. The field size dependence of the PIN diode response is within 1% with respect to the response of ionisation chamber. These studies indicate that the characteristics of the PIN diode are suitable for use in radiotherapy dosimetry.

  7. The Safe Zone for External Fixator Pins in the Femur (United States)


    anatomy to avoid inad- vertent neurovascular injury and intra-articular pin penetra- tion.7,8 Pins placed into the shaft of the femur can be in a lateral...trochanter (LT), perpendicular to the femoral shaft. The final step involved palpation of the superior border of the patella, which was marked. Using a...with SAS 9.1 (Cary, NC). RESULTS Description of Nerve Anatomy The first branch crossed the femur at an average distance from the ASIS of 107 ± 22 mm

  8. Overexpression of PvPin1, a Bamboo Homolog of PIN1-Type Parvulin 1, Delays Flowering Time in Transgenic Arabidopsis and Rice

    Directory of Open Access Journals (Sweden)

    Zhigang Zheng


    Full Text Available Because of the long and unpredictable flowering period in bamboo, the molecular mechanism of bamboo flowering is unclear. Recent study showed that Arabidopsis PIN1-type parvulin 1 (Pin1At is an important floral activator and regulates floral transition by facilitating the cis/trans isomerization of the phosphorylated Ser/Thr residues preceding proline motifs in suppressor of overexpression of CO 1 (SOC1 and agamous-like 24 (AGL24. Whether bamboo has a Pin1 homolog and whether it works in bamboo flowering are still unknown. In this study, we cloned PvPin1, a homolog of Pin1At, from Phyllostachys violascens (Bambusoideae. Bioinformatics analysis showed that PvPin1 is closely related to Pin1-like proteins in monocots. PvPin1 was widely expressed in all tested bamboo tissues, with the highest expression in young leaf and lowest in floral bud. Moreover, PvPin1 expression was high in leaves before bamboo flowering then declined during flower development. Overexpression of PvPin1 significantly delayed flowering time by downregulating SOC1 and AGL24 expression in Arabidopsis under greenhouse conditions and conferred a significantly late flowering phenotype by upregulating OsMADS56 in rice under field conditions. PvPin1 showed subcellular localization in both the nucleus and cytolemma. The 1500-bp sequence of the PvPin1 promoter was cloned, and cis-acting element prediction showed that ABRE and TGACG-motif elements, which responded to abscisic acid (ABA and methyl jasmonate (MeJA, respectively, were characteristic of P. violascens in comparison with Arabidopsis. On promoter activity analysis, exogenous ABA and MeJA could significantly inhibit PvPin1 expression. These findings suggested that PvPin1 may be a repressor in flowering, and its delay of flowering time could be regulated by ABA and MeJA in bamboo.

  9. Resisting Weakness of the Will. (United States)

    Levy, Neil


    I develop an account of weakness of the will that is driven by experimental evidence from cognitive and social psychology. I will argue that this account demonstrates that there is no such thing as weakness of the will: no psychological kind corresponds to it. Instead, weakness of the will ought to be understood as depletion of System II resources. Neither the explanatory purposes of psychology nor our practical purposes as agents are well-served by retaining the concept. I therefore suggest that we ought to jettison it, in favour of the vocabulary and concepts of cognitive psychology.

  10. Discharging pin sites following K-wire fixation of distal radial fractures: a case for pin removal? (United States)

    Desai, Aravind; Dramis, Asterios; Thompson, Neville; Board, Tim; Choudhary, Awani


    The aim of this study was to find out whether discharging pin sites following Kirschner-wire fixation of distal radial fractures warrant early wire removal. In a prospective study of 50 patients with a closed distal radial fracture treated by manipulation and either percutaneous or mini-incision Kirschner-wiring, we identified 14 patients (28%) with discharging pin sites. All of the cases were observed within the first two weeks following surgery. Of the 14 cases, only 2 patients had a positive swab culture and were treated with systemic antibiotics. In all cases the Kirschner wires were left in situ until serial radiographs demonstrated satisfactory union. Three patients (8.6%) in the percutaneous group had superficial radial nerve irritation, which settled following wire removal. Deep soft tissue infection, pyoarthrosis, osteomyelitis, and extensor tendon rupture were not encountered. We conclude that pin site discharge, whether sterile or infected, is in general not an indication for early wire removal.

  11. Weak Coupling Phases future directions

    CERN Document Server

    Rosner, Jonathan L.


    Recent results obtained from B decays on the phases of weak couplings described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix are discussed, with particular emphasis on $\\alpha$ and $\\gamma = \\pi - \\beta - \\alpha$.

  12. Weakly compact operators and interpolation


    Maligranda, Lech


    The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...

  13. Weak interactions of elementary particles

    CERN Document Server

    Okun, Lev Borisovich


    International Series of Monographs in Natural Philosophy, Volume 5: Weak Interaction of Elementary Particles focuses on the composition, properties, and reactions of elementary particles and high energies. The book first discusses elementary particles. Concerns include isotopic invariance in the Sakata model; conservation of fundamental particles; scheme of isomultiplets in the Sakata model; universal, unitary-symmetric strong interaction; and universal weak interaction. The text also focuses on spinors, amplitudes, and currents. Wave function, calculation of traces, five bilinear covariants,

  14. Acute muscular weakness in children

    Directory of Open Access Journals (Sweden)

    Ricardo Pablo Javier Erazo Torricelli

    Full Text Available ABSTRACT Acute muscle weakness in children is a pediatric emergency. During the diagnostic approach, it is crucial to obtain a detailed case history, including: onset of weakness, history of associated febrile states, ingestion of toxic substances/toxins, immunizations, and family history. Neurological examination must be meticulous as well. In this review, we describe the most common diseases related to acute muscle weakness, grouped into the site of origin (from the upper motor neuron to the motor unit. Early detection of hyperCKemia may lead to a myositis diagnosis, and hypokalemia points to the diagnosis of periodic paralysis. Ophthalmoparesis, ptosis and bulbar signs are suggestive of myasthenia gravis or botulism. Distal weakness and hyporeflexia are clinical features of Guillain-Barré syndrome, the most frequent cause of acute muscle weakness. If all studies are normal, a psychogenic cause should be considered. Finding the etiology of acute muscle weakness is essential to execute treatment in a timely manner, improving the prognosis of affected children.

  15. Precision metrology using weak measurements. (United States)

    Zhang, Lijian; Datta, Animesh; Walmsley, Ian A


    Weak values and measurements have been proposed as a means to achieve dramatic enhancements in metrology based on the greatly increased range of possible measurement outcomes. Unfortunately, the very large values of measurement outcomes occur with highly suppressed probabilities. This raises three vital questions in weak-measurement-based metrology. Namely, (Q1) Does postselection enhance the measurement precision? (Q2) Does weak measurement offer better precision than strong measurement? (Q3) Is it possible to beat the standard quantum limit or to achieve the Heisenberg limit with weak measurement using only classical resources? We analyze these questions for two prototypical, and generic, measurement protocols and show that while the answers to the first two questions are negative for both protocols, the answer to the last is affirmative for measurements with phase-space interactions, and negative for configuration space interactions. Our results, particularly the ability of weak measurements to perform at par with strong measurements in some cases, are instructive for the design of weak-measurement-based protocols for quantum metrology.

  16. Comparative evaluation of pin-in-fiberglass cast and Kirschner ...

    African Journals Online (AJOL)

    Four adult (two males and two females) dogs were used to comparatively evaluate the effectiveness of pin-in-fiberglass cast with Kirschner-Ehmer type I external skeletal fixative in the management of surgically created radius-ulna fractures in dogs. These dogs were assigned to two groups (A and B) with each group made ...

  17. Registration of fluorescence in biomolecular solutions using dynamic pin photodiode (United States)

    Savchenko, E. A.; Nepomnyashchaya, E. K.; Dyubo, D. B.; Velichko, E. N.; Tsybin, O. Yu


    The application of a dynamic pin-photodiode as a recording device of the fluorescence radiation is considered. An experimental setup for registration of luminescence signals from biomolecules excited by laser radiation was developed. Rhodamine 6G and chlorophyll were investigated.

  18. Vortex lattice mobility and effective pinning potentials in the peak ...

    Indian Academy of Sciences (India)

    In that region of field and temperature the mobility of the vortex lattice (VL) is found to be dependent on the dynamical history. Recently we reported evidence that the VL reorganizes and accesses to robust VL configurations (VLCs) with different effective pinning potential wells arising in response to different system histories.

  19. Ising antiferromagnet with mobile, pinned, and quenched defects

    Directory of Open Access Journals (Sweden)



    Full Text Available Motivated by recent experiments on (Sr,Ca,La14Cu24O41, a two-dimensional Ising antiferromagnet with mobile, locally pinned and quenched defects is introduced and analyzed using mainly Monte Carlo techniques. The interplay between the arrangement of the defects and the magnetic ordering as well as the effect of an external field are studied.

  20. Flux-Vortex Pinning and Neutron Star Evolution

    Indian Academy of Sciences (India)

    G. Srinivasan et al. (1990) proposed a simple and elegant explanation for the reduction of the neutron star magnetic dipole moment during binary evolution leading to low mass X-ray binaries and eventually to millisecond pulsars: Quantized vortex lines in the neutron star core superfluid will pin against the quantized flux ...

  1. 1071-IJBCS-Article-Crépin Pene

    African Journals Online (AJOL)


    :// Late season sugarcane performance as affected by soil water deficit at the yield formation stage in commercial farms of northern Ivory Coast. Crépin B. PÉNÉ *, Marco H. OUATTARA and Sylvain G. KOULIBALY.

  2. Comparative evaluation of pin-in-fiberglass cast and Kirschner ...

    African Journals Online (AJOL)



    Mar 30, 2017 ... two dogs. The radius-ulna fracture was created in all the dogs under general anaesthesia as follows: Group A, .... Plate V: The middle pins inserted through the remaining two open ..... fractures in dogs and cats in Tripoli-Libya.

  3. Analyzing the use of pins in safety bearings

    DEFF Research Database (Denmark)

    da Fonseca, Cesar A. L. L.; Weber, Hans I.; Fleischer, Philip F.


    A new concept for safety bearings is analyzed: useful in emergency situations, it shall protect the bearing from destruction by the use of pins which impact with a disc, both capable of good energy dissipation. Results of work in progress are presented by validating partial stages of the developm...

  4. ``Pinning strategy": a novel approach for predicting the backbone ...

    Indian Academy of Sciences (India)


    Sep 6, 2006 ... In this study, we propose a new method called “pinning strategy” that used this specific feature to predict long protein fragments. Its goal is to define highly probable successions of PBs. It starts from the most probable SW and is then extended with overlapping SWs. Starting from an initial prediction rate of ...

  5. Primary Crystallization Studies and Abrasion Analysis of Cr-Ni-Mo Cast Steel

    Directory of Open Access Journals (Sweden)

    Studnicki A.


    Full Text Available The article shows results of studies of primary crystallization and wear resistance of Cr-Ni-Mo cast steel intended for work in corrosive and abrasive conditions. The studies of primary crystallization were conducted with use of TDA method and modified tester allowing measurement casting cooling time influence on the cooling and crystallization curves of studied alloys. After heat treatment of examined cast steel wear tests of the samples were conducted on pin-on-disc type device.

  6. Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

    Directory of Open Access Journals (Sweden)

    Fengming Wang


    Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.



    Pravin*, Jeyapratha


    This paper ambit to evaluate the flexural strength of glass fiber sandwich panels with varying z-pins pitches. Failure of sandwich panel are delamination and core shear, to minimize the crack propagation, pins are inserted in z-direction, by varying pitches through its thickness. During the insertion of pin, may cause the material some damage. Despite the damage, flexural property does not affected due interpolation of pins. Although the experiment were pull out with a phenomenal results of z...

  8. New Universal Tribometer as Pin or Ball-on-Disc and Reciprocating Pin-on-Plate Types

    Directory of Open Access Journals (Sweden)

    H. Kaleli


    Full Text Available The present paper contains a description of a new Universal Tribometer design which enables simulation of different contact and test types such as pin-on-disc, ball-on-disc and linear reciprocating tests. There are many models of wear Tribometer in the world market. These devices are manufactured by various companies abroad and are imported to our country. Cost of this devices start from 50.000 euros and goes to hundreds of thousands of euros. One of the most commonly used of this device is Reciprocating Pin-on-Plate Tribo Test Machine. This wear tester is produced at a low limited cost within the KAP (Scientifical Research Project Coordinator of Yıldız Technical University. The test machine can work including three types of Tribotest rigs (Reciprocating Pin-on-Plate, Pin-on-Disc and Ball-on-Disc. It is designed to operate also at high temperatures up to 500 ˚C. The new piece of equipment allows instrumented tribological testing of piston ring and cylinder liner samples at low and high temperatures and boundary lubrication conditions of any typical gasoline or Diesel engines. Some friction results were shown in boundary lubricating conditions between piston ring and cylinder liner sliding pairs describing Tribotest machine is driven by AC servo motor which is more accurate than DC motor.

  9. Use of a modified transfixation pin cast for treatment of comminuted phalangeal fractures in horses. (United States)

    Rossignol, Fabrice; Vitte, Amélie; Boening, Josef


    To (1) report a modified transfixation pin cast technique, using dorsal recumbency for fracture reduction, distal positioning of the pins in the epiphysis and distal metaphysis, and a hybrid cast, combining plaster of Paris (POP) and fiberglass casting, and (2) report outcome in 11 adult horses. Case series. Adult horses (n = 11) with comminuted phalangeal fractures. Horses were anesthetized and positioned in dorsal recumbency. The phalangeal fracture was reduced by limb traction using a cable attached to the hoof. Screw fixation in lag fashion of fracture fragments was performed when possible. Transfixation casting was performed using two 6.3 mm positive profile centrally threaded pins with the 1st pin placed in the epiphysis of the metacarpus/tarsus at the center of, or slightly proximal to, the condylar fossa and the 2nd one 3-4 cm proximal. A hybrid cast was applied. Forelimbs were involved in 9 horses and the hind limb in 2. Pins were maintained for a minimum of 6 weeks. No pin loosening was observed at the time of removal (6-8 weeks). A pony fractured the distal aspect of the metacarpus at the proximal pin. Nine horses survived (82%); none of the horses developed septic arthritis despite the distal location of the distal pin, close to the fetlock joint. This modified transfixation pin casting technique was associated with good pin longevity and could reduce the risk of secondary pin hole fractures and pin loosening. © Copyright 2013 by The American College of Veterinary Surgeons.

  10. PIN protein phosphorylation by plant AGC3 kinases and its role in polar auxin transport

    NARCIS (Netherlands)

    Huang, Fang


    Polar cell-to-cell transport of plant hormone auxin mediated by plasma membrane (PM)-localized PIN-FORMED (PIN) auxin efflux carriers generates auxin gradients that provide positional information for various plant developmental processes. The apical-basal polar localization of the PIN proteins that

  11. The PIN family of proteins in potato and their putative role in tuberisation

    Directory of Open Access Journals (Sweden)

    Efstathios eRoumeliotis


    Full Text Available The PIN family of trans-membrane proteins mediates auxin efflux throughout the plant and during various phases of plant development. In Arabidopsis thaliana, the PIN family comprised of 8 members, divided into ‘short’ and ‘long’ PINs according to the length of the hydrophilic domain of the protein. Based on sequence homology using the recently published potato genome sequence (Solanum tuberosum group Phureja we identified ten annotated potato StPIN genes. Mining the publicly available gene expression data, we constructed a catalogue tissue specificity of StPIN gene expression, focusing on the process of tuberization. A total of four StPIN genes exhibited increased expression four days after tuber induction, prior to the onset of stolon swelling. For two PIN genes, StPIN4 and StPIN2, promoter sequences were cloned and fused to the GUS reporter protein to study tissue specificity in more detail. StPIN4 promoter driven GUS staining was detected in the flower stigma, in the flower style, below the ovary and petals, in the root tips, in the vascular tissue of the stolons and in the tuber parenchyma cells. StPIN2 promoter driven GUS staining was detected in flower buds, in the vascular tissue of the swelling stolons and in the storage parenchyma of the growing tubers. Based on our results, we postulate a role for the StPINs in redistributing auxin in the swelling stolon during early events in tuber development.

  12. Role of PIN1 on in vivo periodontal tissue and in vitro cells. (United States)

    Park, K-H; Cho, E-H; Bae, W-J; Kim, H-S; Lim, H-C; Park, Y-D; Lee, M-O; Cho, E-S; Kim, E-C


    Although expression of peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (PIN1) was reported in bone tissue, the precise role of PIN1 in periodontal tissue and cells remain unclear. To elucidate the roles of PIN1 in periodontal tissue, its expression in periodontal tissue and cells, and effects on in vitro 4 osteoblast differentiation and the underlying signaling mechanisms were evaluated. PIN1 was expressed in mouse periodontal tissues including periodontal ligament cells (PDLCs), cementoblasts and osteoblasts at the developing root formation stage (postnatal, PN14) and functional stage of tooth (PN28). Treatment of PIN1 inhibitor juglone, and gene silencing by RNA interference promoted osteoblast differentiation in PDLCs and cementoblasts, whereas the overexpression of PIN1 inhibited. Moreover, osteogenic medium-induced activation of AMPK, mTOR, Akt, ERK, p38 and NF-jB pathways were enhanced by PIN1 siRNA, but attenuated by PIN1 overexpression. Runx2 expressions were induced by PIN1 siRNA, but downregulated by PIN1 overexpression. In summary, this study is the first to demonstrate that PIN1 is expressed in developing periodontal tissue, and in vitro PDLCs and cementoblasts. PIN1 inhibition stimulates osteoblast differentiation, and thus may play an important role in periodontal regeneration. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. A comparison of twin boundary pinning in nearly fully stoichiometric and oxygen deficient YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}

    Energy Technology Data Exchange (ETDEWEB)

    Fleshler, S.; Kwok, W.K.; Welp, U.; Downey, J.; Crabtree, G.W.


    The angular dependence of the magnetoresistance was measured on the same single crystal of a YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} prepared initially with a superconducting transition temperature of 93.0K and then annealed to obtain a transition temperature of 56.9K. A second oxygen deficient sample was produced with a transition temperature 57.0K and nearly identical transport characteristics. Twin boundary pinning superimposed on flux flow behavior was observed in both the 56.9K and 93.0K states for magnetic field rotation in ab plane. For magnetic field rotations off the c axis we observe twin boundary pinning only for the nearly stoichiometric state. We find the broadening of the resistive transition in magnetic field (H {parallel} c) to occur over a much larger interval of reduced temperature in the deoxygenated state. The enhanced broadening of the resistive transition in magnetic field and absence of twin boundary pinning may indicate that the vortex system is two dimensional and in general, defects are rendered ineffective in pinning due to the absence of three dimensional collective elastic effects.

  14. Quantum discord with weak measurements

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Uttam, E-mail:; Pati, Arun Kumar, E-mail:


    Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the “super quantum discord”, is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a function of the measurement strength and in the limit of strong projective measurement the super quantum discord becomes the normal quantum discord. We find that unlike the normal discord, for pure entangled states, the super quantum discord can exceed the quantum entanglement. Our results provide new insights on the nature of quantum correlation and suggest that the notion of quantum correlation is not only observer dependent but also depends on how weakly one perturbs the composite system. We illustrate the key results for pure as well as mixed entangled states. -- Highlights: •Introduced the role of weak measurements in quantifying quantum correlation. •We have introduced the notion of the super quantum discord (SQD). •For pure entangled state, we show that the SQD exceeds the entanglement entropy. •This shows that quantum correlation depends not only on observer but also on measurement strength.

  15. Weak bond detection in composites using highly nonlinear solitary waves (United States)

    Singhal, Taru; Kim, Eunho; Kim, Tae-Yeon; Yang, Jinkyu


    We experimentally investigate a diagnostic technique for identifying a weak bond in composites using highly nonlinear solitary waves (HNSWs). We set up a one-dimensional chain of granular crystals, consisting of spherical particles with nonlinear interactions, to generate HNSWs. These solitary wave packets are transmitted into an inspection area of composites by making a direct contact with the chain. We demonstrate that a strong type of solitary waves injected to the weak bond area can break the weak bond of laminates, thereby causing delamination. Then, to identify the creation of the delamination, we transmit a weak type of solitary waves by employing the same apparatus, and measure the solitary waves reflected from the specimens. By analyzing these reflected solitary waves, we differentiate the weak bond samples with the pristine bond ones in an efficient and fast manner. The diagnostic results based on the proposed method are compared with the strength and energy release rate at bond interfaces, which are measured via standard testing methods such as three point bending and end notched flexure tests. This study shows the potential of solitary wave-based detection of weak bonds for hot spot monitoring of composite-based structures.

  16. Fabrication and performance of p-i-n CdTe radiation detectors

    CERN Document Server

    Niraula, M; Aoki, T; Tomita, Y; Nihashi, T; Hatanaka, Y


    We report on the fabrication and performance of CdTe radiation detectors in a new p-i-n structure which helps to reduce the leakage current to a minimum level. Chlorine-doped single-crystal CdTe substrates having resistivity in the order of 10 sup 9 OMEGA cm were used in this study. Iodine-doped n-type CdTe layers were grown homoepitaxially on one face of each crystals using the hydrogen plasma-radical-assisted metalorganic chemical vapor deposition technique at low substrate temperature of 150 deg. C. Indium electrode was evaporated on the n-CdTe side while a gold electrode on the opposite side acted as a p-type contact. Detectors thus fabricated exhibited low leakage current (below 0.4 nA/mm sup 2 at 250 V applied reverse bias for the best one) and good performance at room temperature. Spectral response of the detectors showed improved energy resolution for Am-241, Co-57, and Cs-137 radioisotopes. Detectors were further tested with X-ray photons of different intensities for their potential application in im...

  17. Screening and Crystallization Plates for Manual and High-throughput Protein Crystal Growth (United States)

    Thorne, Robert E. (Inventor); Berejnov, Viatcheslav (Inventor); Kalinin, Yevgeniy (Inventor)


    In one embodiment, a crystallization and screening plate comprises a plurality of cells open at a top and a bottom, a frame that defines the cells in the plate, and at least two films. The first film seals a top of the plate and the second film seals a bottom of the plate. At least one of the films is patterned to strongly pin the contact lines of drops dispensed onto it, fixing their position and shape. The present invention also includes methods and other devices for manual and high-throughput protein crystal growth.

  18. Crystal rainbows

    Energy Technology Data Exchange (ETDEWEB)

    Neskovic, N. E-mail:; Petrovic, S


    This review is devoted to ion transmission through axial channels of thin crystals. In this process the rainbows occur. The effect is called the crystal rainbow effect. We shall describe its origin and present the experiments in which it has been observed. We shall explain also how the crystal rainbows can be classified using catastrophe theory. This classification has resulted in a universal, simple and accurate approximation to the continuum potential in the channels. Besides, the periodicity of the angular distributions of transmitted ions with the reduced crystal thickness will be considered. It will be introduced via the effect of zero-degree focusing of channeled ions. In addition, we shall mention the doughnut effect in ion channeling, which has proven to be the rainbow effect with tilted crystals. All these considerations will demonstrate clearly the usefulness of the theory of crystal rainbows, which is the proper theory of ion channeling in thin crystals00.

  19. Warping the Weak Gravity Conjecture

    Directory of Open Access Journals (Sweden)

    Karta Kooner


    Full Text Available The Weak Gravity Conjecture, if valid, rules out simple models of Natural Inflation by restricting their axion decay constant to be sub-Planckian. We revisit stringy attempts to realise Natural Inflation, with a single open string axionic inflaton from a probe D-brane in a warped throat. We show that warped geometries can allow the requisite super-Planckian axion decay constant to be achieved, within the supergravity approximation and consistently with the Weak Gravity Conjecture. Preliminary estimates of the brane backreaction suggest that the probe approximation may be under control. However, there is a tension between large axion decay constant and high string scale, where the requisite high string scale is difficult to achieve in all attempts to realise large field inflation using perturbative string theory. We comment on the Generalized Weak Gravity Conjecture in the light of our results.

  20. Cosmology and the weak interaction

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N. (Fermi National Accelerator Lab., Batavia, IL (USA)):(Chicago Univ., IL (USA))


    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.

  1. Nonlinear waves and weak turbulence

    CERN Document Server

    Zakharov, V E


    This book is a collection of papers on dynamical and statistical theory of nonlinear wave propagation in dispersive conservative media. Emphasis is on waves on the surface of an ideal fluid and on Rossby waves in the atmosphere. Although the book deals mainly with weakly nonlinear waves, it is more than simply a description of standard perturbation techniques. The goal is to show that the theory of weakly interacting waves is naturally related to such areas of mathematics as Diophantine equations, differential geometry of waves, Poincaré normal forms, and the inverse scattering method.

  2. Dynamics of Skyrmion crystals in metallic thin films. (United States)

    Zang, Jiadong; Mostovoy, Maxim; Han, Jung Hoon; Nagaosa, Naoto


    We study the collective dynamics of the Skyrmion crystal in thin films of ferromagnetic metals resulting from the nontrivial Skyrmion topology. It is shown that the current-driven motion of the crystal reduces the topological Hall effect and the Skyrmion trajectories bend away from the direction of the electric current (the Skyrmion Hall effect). We find a new dissipation mechanism in noncollinear spin textures that can lead to a much faster spin relaxation than Gilbert damping, calculate the dispersion of phonons in the Skyrmion crystal, and discuss the effects of impurity pinning of Skyrmions.

  3. The prolyl isomerase Pin1 increases β-cell proliferation and enhances insulin secretion. (United States)

    Nakatsu, Yusuke; Mori, Keiichi; Matsunaga, Yasuka; Yamamotoya, Takeshi; Ueda, Koji; Inoue, Yuki; Mitsuzaki-Miyoshi, Keiko; Sakoda, Hideyuki; Fujishiro, Midori; Yamaguchi, Suguru; Kushiyama, Akifumi; Ono, Hiraku; Ishihara, Hisamitsu; Asano, Tomoichiro


    The prolyl isomerase Pin1 binds to the phosphorylated Ser/Thr-Pro motif of target proteins and enhances their cis-trans conversion. This report is the first to show that Pin1 expression in pancreatic β cells is markedly elevated by high-fat diet feeding and in ob/ob mice. To elucidate the role of Pin1 in pancreatic β cells, we generated β-cell-specific Pin1 KO (βPin1 KO) mice. These mutant mice showed exacerbation of glucose intolerance but had normal insulin sensitivity. We identified two independent factors underlying impaired insulin secretion in the βPin1 KO mice. Pin1 enhanced pancreatic β-cell proliferation, as indicated by a reduced β-cell mass in βPin1 KO mice compared with control mice. Moreover, a diet high in fat and sucrose failed to increase pancreatic β-cell growth in the βPin1 KO mice, an observation to which up-regulation of the cell cycle protein cyclin D appeared to contribute. The other role of Pin1 was to activate the insulin-secretory step: Pin1 KO β cells showed impairments in glucose- and KCl-induced elevation of the intracellular Ca 2+ concentration and insulin secretion. We also identified salt-inducible kinase 2 (SIK2) as a Pin1-binding protein that affected the regulation of Ca 2+ influx and found Pin1 to enhance SIK2 kinase activity, resulting in a decrease in p35 protein, a negative regulator of Ca 2+ influx. Taken together, our observations demonstrate critical roles of Pin1 in pancreatic β cells and that Pin1 both promotes β-cell proliferation and activates insulin secretion. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Effect of PVA doping on flux pinning in bulk MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Vajpayee, Arpita [National Physical Laboratory, K.S. Krishnan Marg, New Delhi (India); Awana, V.P.S. [National Physical Laboratory, K.S. Krishnan Marg, New Delhi (India); National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)], E-mail:; Balamurugan, S.; Takayama-Muromachi, E. [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Kishan, H. [National Physical Laboratory, K.S. Krishnan Marg, New Delhi (India); Bhalla, G.L. [Department of Physics and Astrophysics, University of Delhi, New Delhi (India)


    The synthesis and characterization of PVA (Poly Vinyl Acetate) doped bulk MgB{sub 2} superconductor is reported here. PVA is used as a carbon source. PVA doping effects made two distinguishable contributions: first enhancement of J{sub c} field performance and second an increase in H{sub c2} value, both because of carbon incorporation into MgB{sub 2} crystal lattice. The susceptibility measurement reveals that T{sub c} decreased from 37 to 36 K. Lattice parameter 'a' decreased from 3.085 A to 3.081 A due to the partial substitution of carbon at boron site. PVA doped sample exhibited the J{sub c} values greater than 10{sup 5} A/cm{sup 2} at 5 and 10 K at low fields; which is almost 3 times higher than the pure one, while at high fields the J{sub c} is increased by an order of magnitude in comparison to pure MgB{sub 2}. From {rho}(T)H measurements we found higher T{sub c} values under magnetic field for doped sample; indicating an increase in H{sub c2}. Also the magnetization measurements exhibited a significant enhancement in H{sub irr} value. The improved performance of PVA doped MgB{sub 2} can be attributed to the substitution of carbon at boron site in parent MgB{sub 2} and the resulting impact on the carrier density and impurity scattering. The improved flux pinning behavior could easily be seen from reduced flux pinning force plots.

  5. Submanifolds weakly associated with graphs

    Indian Academy of Sciences (India)

    Sci. (Math. Sci.) Vol. 119, No. 3, June 2009, pp. 297–318. © Printed in India. Submanifolds weakly associated with graphs. A CARRIAZO, L M FERN ´ANDEZ and A RODRÍGUEZ-HIDALGO. Department of Geometry and Topology, Faculty of Mathematics, University of Sevilla,. Apartado de Correos 1160, 41080-Sevilla, Spain.

  6. Beam splitting on weak illumination. (United States)

    Snyder, A W; Buryak, A V; Mitchell, D J


    We demonstrate, in both two and three dimensions, how a self-guided beam in a non-Kerr medium is split into two beams on weak illumination. We also provide an elegant physical explanation that predicts the universal character of the observed phenomenon. Possible applications of our findings to guiding light with light are also discussed.

  7. On Weak-BCC-Algebras (United States)

    Thomys, Janus; Zhang, Xiaohong


    We describe weak-BCC-algebras (also called BZ-algebras) in which the condition (x∗y)∗z = (x∗z)∗y is satisfied only in the case when elements x, y belong to the same branch. We also characterize ideals, nilradicals, and nilpotent elements of such algebras. PMID:24311983

  8. Voltage Weak DC Distribution Grids

    NARCIS (Netherlands)

    Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.


    This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of

  9. Active cloaking for clusters of pins in thin plates

    CERN Document Server

    O'Neill, Jane; Haslinger, Stewart; Movchan, Natasha; Craster, Richard


    This paper considers active cloaking of a square array of evenly spaced pins in a Kirchhoff plate in the presence of flexural waves. Active sources are distributed exterior to the cluster and are represented by the non-singular Green's function for the biharmonic operator. The complex amplitudes of the active sources, which cancel out selected multipole orders of the scattered field, are found by solving an algebraic system of equations. For frequencies in the zero-frequency stop band, we find that a small number of active sources located on a grid is sufficient for cloaking. For higher frequencies, we achieve efficient cloaking with the active sources positioned on a circle surrounding the cluster. We demonstrate the cloaking efficiency with several numerical illustrations, considering key frequencies from band diagrams and dispersion surfaces for a Kirchhoff plate pinned in a doubly periodic fashion.

  10. Study of the Radiation-Hardness of VCSEL and PIN

    CERN Document Server

    Gan, K K; Fernando, W; Kagan, H P; Kass, R D; Lebbai, M R M; Merritt, H; Moore, J R; Nagarkar, A; Rizatdinova, F; Skubic, P L; Smith, D S; Strang, M


    The silicon trackers of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN (Geneva) use optical links for data transmission. An upgrade of the trackers is planned for the Super LHC (SLHC), an upgraded LHC with ten times higher luminosity. We study the radiation-hardness of VCSELs (Vertical-Cavity Surface-Emitting Laser) and GaAs and silicon PINs using 24 GeV/c protons at CERN for possible application in the data transmission upgrade. The optical power of VCSEL arrays decreases significantly after the irradiation but can be partially annealed with high drive currents. The responsivities of the PIN diodes also decrease significantly after irradiation, but can be recovered by operating at higher bias voltage. This provides a simple mechanism to recover from the radiation damage.

  11. Subdural abscess associated with halo-pin traction. (United States)

    Garfin, S R; Botte, M J; Triggs, K J; Nickel, V L


    Osteomyelitis and intracranial abscess are among the most serious complications that have been reported in association with the use of the halo device. The cases of five patients who had formation of an intracranial abscess related to the use of a halo cervical immobilizer are described. All of the infections resolved after drainage of the abscess, débridement, and parenteral administration of antibiotics. Meticulous care of the pin sites is essential to avoid this serious complication. Additionally, since all of the infections were associated with prolonged halo-skeletal traction, this technique should be used with caution and with an awareness of the possible increased risks of pin-site infection and of formation of a subdural abscess.

  12. Leituras semióticas de Pinóquio

    Directory of Open Access Journals (Sweden)

    Rafael Giardini Lenzi


    Full Text Available Esta resenha faz breve exposição do conteúdo de Pinocchio: nuove avventure tra segni e linguaggi, organizado por Paolo Fabbri e Isabella Pezzini, que apresenta dez artigos e um tautograma que tratam do tema Pinóquio, alternando entre elementos do texto original, elementos presentes em variações do romance e abordagens sobre a tradução ou a variação em si, sob a óptica da semiótica discursiva. A perseverança e forte proliferação do tema Pinóquio, originalmente ou sob outros pontos de vista trazidos pelos meios de comunicação, estabelece o texto como uma fábula da atualidade que sempre atraiu o olhar científico.

  13. Matching of the Flux Lattice to Geometrically Frustrated Pinning Arrays (United States)

    Trastoy, J.; Bernard, R.; Briatico, J.; Villegas, J. E.; Lesueur, J.; Ulysse, C.; Faini, G.


    We use vortex dynamics on artificial nanoscale energy landscapes as a model to experimentally investigate a problem inspired by ``spin ice'' systems. In particular, we study the matching of the flux lattice to pinning arrays in which the geometrical frustration is expected to impede a unique stable vortex configuration and to promote metastability. This is done with YBCO films in which the nanoscale vortex energy landscape is fabricated via masked ion irradiation. Surprisingly, we found that minimal changes in the distance between pinning sites lead to the suppression of some of the magneto-resistance matching effects, that is, for certain well-defined vortex densities. This effect strongly depends on the temperature. We argue that this behavior can be explained considering the arrays' geometrical frustration and the thermally activated reconfiguration of the vortex lattice between isoenergetic states. Work supported by the French ANR via SUPERHYRBIDS-II and ``MASTHER,'' and the Galician Fundacion Barrie

  14. Nonlinearity measurements of PIN photodiode based ROSA for FTTX applications (United States)

    Wang, Xinzhong; He, Chun; Li, Yao; Zhou, Andy; Tsay, Wei-Shin


    We have designed and fabricated PIN photodiode based ROSA used for FTTX applications. The critical nonlinearity parameters of Inter-modulation Distortion (IMD) were measured by two RF modulated light sources near 1550nm wavelength channels. A cost effective measuring system with narrow pass band filter was set up and some procedures were utilized for determining the low level signals of IMD. Obtained test results were used in real time to guide packaging process to achieve best receiver performance.

  15. Investigation of silicon PIN-detector for laser pulse detection


    Chau, Sam


    This report has been written at SAAB Bofors Dynamics (SBD) AB in Gothenburg at the department of optronic systems. In military observation operations, a target to hit is chosen by illumination of a laser designator. From the targetpoint laser radiation is reflected on a detector that helps identify the target. The detector is a semiconductor PIN-type that has been investigated in a laboratory environment together with a specially designed laser source. The detector is a photodiode and using p...

  16. Prevention of pin tract infection with titanium-copper alloys. (United States)

    Shirai, Toshiharu; Tsuchiya, Hiroyuki; Shimizu, Tohru; Ohtani, Kaori; Zen, Yo; Tomita, Katsuro


    The most frequent complication in external fixation is pin tract infection. To reduce the incidence of implant-associated infection, many published reports have looked at preventing bacterial adhesion by treating the pin surface. This study aimed to evaluate the antibacterial activity of a Titanium-Copper (Ti-Cu) alloy on implant infection, and to determine the potential use of the Ti-Cu alloy as a biomaterial. Two forms of Ti-Cu alloys were synthesized: one with 1% Cu and the other with 5% Cu. For analyzing infectious behavior, the implants were exposed to Staphylococcus aureus and Escherichia coli. The reaction of pathogens to the Ti-Cu alloys was compared with their reaction to stainless steel and pure titanium as controls. Both Ti-Cu alloys evidently inhibited colonization by both bacteria. Conversely, cytocompatibility studies were performed using fibroblasts and colony formation on the metals was assessed by counting the number of colonies. Ti-1% Cu alloy showed no difference in the number of colonies compared with the control. External fixator pins made of Ti-Cu alloys were evaluated in a rabbit model. The tissue-implant interactions were analyzed for the presence of infection, inflammatory changes and osteoid-formation. Ti-1% Cu alloy significantly inhibited inflammation and infection, and had excellent osteoid-formation. Copper blood levels were measured before surgery and at 14 days postoperatively. Preoperative and postoperative blood copper values were not statistically different. Overall, it was concluded that Ti-Cu alloys have antimicrobial activity and substantially reduce the incidence of pin tract infection. Ti-1% Cu alloy shows particular promise as a biomaterial. (c) 2009 Wiley Periodicals, Inc.

  17. Anticipating WPS PIN Vulnerability to Secure Wireless Network

    Directory of Open Access Journals (Sweden)

    Indra Dwi Rianto


    Full Text Available WiFi Protected Setup (WPS is a standardized function supported by numerous vendors of wireless routers and access point to help set up connection to a wireless local area network. It is designed to simplify the set up and generally enabled by default. Due to design flaw, the WPS or QSS PIN is susceptible to a brute forceattack. In this paper, we test the security vulnerability occurred, evaluate the performance and give recommendations to anticipate the attack.

  18. Performance of a TiN-coated monolithic silicon pin-diode array under mechanical stress

    Energy Technology Data Exchange (ETDEWEB)

    VanDevender, B.A., E-mail: [Center for Experimental Nuclear Physics and Astrophysics and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Bodine, L.I.; Myers, A.W.; Amsbaugh, J.F.; Howe, M.A.; Leber, M.L.; Robertson, R.G.H.; Tolich, K.; Van Wechel, T.D.; Wall, B.L. [Center for Experimental Nuclear Physics and Astrophysics and Department of Physics, University of Washington, Seattle, WA 98195 (United States)


    The Karlsruhe Tritium Neutrino Experiment (KATRIN) will detect tritium {beta}-decay electrons that pass through its electromagnetic spectrometer with a highly segmented monolithic silicon pin-diode focal-plane detector (FPD). This pin-diode array will be on a single piece of 500-{mu}m-thick silicon, with contact between titanium nitride (TiN)-coated detector pixels and front-end electronics made by spring-loaded pogo pins. The pogo pins will exert a total force of up to 50 N on the detector, deforming it and resulting in mechanical stress up to 50 MPa in the silicon bulk. We have evaluated a prototype pin-diode array with a pogo-pin connection scheme similar to the KATRIN FPD. We find that pogo pins make good electrical contact to TiN and observe no effects on detector resolution or reverse-bias leakage current which can be attributed to mechanical stress.

  19. Enhancing speed of pinning synchronizability: low-degree nodes with high feedback gains

    CERN Document Server

    Zhou, Ming-Yang; Liao, Hao; Fu, Zhong-Qian; Cai, Shi-Min


    Controlling complex networks is of paramount importance in science and engineering. Despite recent efforts to improve controllability and synchronous strength, little attention has been paid to the speed of pinning synchronizability (rate of convergence in pinning control) and the corresponding pinning node selection. To address this issue, we propose a hypothesis to restrict the control cost, then build a linear matrix inequality related to the speed of pinning controllability. By solving the inequality, we obtain both the speed of pinning controllability and optimal control strength (feedback gains in pinning control) for all nodes. Interestingly, some low-degree nodes are able to achieve large feedback gains, which suggests that they have high influence on controlling system. In addition, when choosing nodes with high feedback gains as pinning nodes, the controlling speed of real systems is remarkably enhanced compared to that of traditional large-degree and large-betweenness selections. Thus, the proposed...

  20. Competing weak localization and weak antilocalization in ultrathin topological insulators. (United States)

    Lang, Murong; He, Liang; Kou, Xufeng; Upadhyaya, Pramey; Fan, Yabin; Chu, Hao; Jiang, Ying; Bardarson, Jens H; Jiang, Wanjun; Choi, Eun Sang; Wang, Yong; Yeh, Nai-Chang; Moore, Joel; Wang, Kang L


    We demonstrate evidence of a surface gap opening in topological insulator (TI) thin films of (Bi(0.57)Sb(0.43))(2)Te(3) below six quintuple layers through transport and scanning tunneling spectroscopy measurements. By effective tuning the Fermi level via gate-voltage control, we unveil a striking competition between weak localization and weak antilocalization at low magnetic fields in nonmagnetic ultrathin films, possibly owing to the change of the net Berry phase. Furthermore, when the Fermi level is swept into the surface gap of ultrathin samples, the overall unitary behaviors are revealed at higher magnetic fields, which are in contrast to the pure WAL signals obtained in thicker films. Our findings show an exotic phenomenon characterizing the gapped TI surface states and point to the future realization of quantum spin Hall effect and dissipationless TI-based applications.

  1. Evidence of domain wall pinning in aluminum substituted cobalt ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, J.C.; Janrao, P.S.; Datar, A.A.; Kanhe, N.S.; Bhoraskar, S.V.; Mathe, V.L.


    In the present work spinel structured cobalt ferrites with aluminum substitution having composition CoAl{sub x}Fe{sub 2−x}O{sub 4} (x=0.0, 0.1, 0.2 and 0.3) have been synthesized using chemical co-precipitation method. Their microstructural, magnetic, magnetostriction and magnetoimpedance properties have been investigated. The piezomagnetic coefficient (dλ/dH) obtained from magnetostriction data is found to enhance with 0.1 Al substitutions in place of iron which decreases with further increase of Al content. It is noticed that 0.3 Al substitutions in place of Fe introduces domain wall pinning as evidenced from magnetostriction, magnetoimpedance and dc magnetization data. It is noted that ferrites so prepared using a simple procedure are magnetostrictive in good measure and with the addition of very small amount of non-magnetic aluminum their magnetostriction has shown saturation at relatively low magnetic fields. Such magnetostrictive ferrites find their applications in magnetic sensors and actuators. - Highlights: • Synthesis and characterization of CoAl{sub x}Fe{sub 2−x}O{sub 4} (x=0.0 to 0.3) ferrites. • Experimental evidence of domain wall pinning. • Analysis of magnetic, micro-structural, structural and spectroscopic data. • Co-relation of the data obtained using various techniques with pinning effect.

  2. Domain wall remote pinning in magnetic nano wires (United States)

    Read, Dan; Miguel, Jorge; Maccherozzi, Francesco; Cavill, Stuart; Dhesi, Sarnjeet; Cardiff University Collaboration; Diamond Light Source Collaboration


    In the current race for information storage media with ever increasing density the position of magnetic domain walls, the region in a magnetic system where the local magnetization continually rotates its direction between adjacent magnetic domains, is one of the most promising routes for future storage media devices. Information storage requires ultrafast read-out and writing operations, but domain walls need to be pinned so that the information is safely stored in the long term. Here we investigate the use of remote magnetostatic charges to trap domain walls. By using X-ray photoelectron emission microscopy we have followed the position of domain walls of opposite charge being pinned or repelled by pinning potentials of increasing strength. Micromagnetic simulations show an excellent agreement with the experimental results. We demonstrate the attractive or repulsive character of the interaction between domain wall and trap depending upon the sign of their magnetic charges. These quasi-static experiments are the antecedent to ultrafast time-resolved XMCD-PEEM experiments where the spin-transfer torque effect will be studied dynamically by applying picosecond-long current pulses across the magnetic nanowire.

  3. Contact and Non-contact Measurements of Grinding Pins

    Directory of Open Access Journals (Sweden)

    Magdziak Marek


    Full Text Available The paper presents the results of contact and non-contact measurements of external profiles of selected grinding pins. The measurements were conducted in order to choose the appropriate measuring technique in the case of the considered measurement task. In the case of contact measurements the coordinate measuring machine ACCURA II was applied. The used coordinate measuring machine was equipped with the contact scanning probe VAST XT and the Calypso inspection software. Contact coordinate measurements were performed by using of different measurement strategies. The applied strategies included different scanning velocities and distances between measured points. Non-contact measurements were conducted by means of the tool presetter produced by the Mahr company. On the basis of gained results the guidelines concerning measurements of grinding pins were formulated. The measurements of analyzed grinding pins performed by means of the non-contact measuring system are characterized by higher reproducibility than the contact measurements. The low reproducibility of contact measurements may be connected with the inaccuracy of the selected coordinate measuring machine and the measuring probe, the measurement parameters and environmental conditions in the laboratory where the coordinate measuring machine is located. Moreover, the paper presents the possible application of results of conducted investigations. The results of non-contact measurements can be used in the simulation studies of grinding processes. The simulations may reduce the costs of machining processes.

  4. Protein Crystallization (United States)

    Chernov, Alexander A.


    Nucleation, growth and perfection of protein crystals will be overviewed along with crystal mechanical properties. The knowledge is based on experiments using optical and force crystals behave similar to inorganic crystals, though with a difference in orders of magnitude in growing parameters. For example, the low incorporation rate of large biomolecules requires up to 100 times larger supersaturation to grow protein, rather than inorganic crystals. Nucleation is often poorly reproducible, partly because of turbulence accompanying the mixing of precipitant with protein solution. Light scattering reveals fluctuations of molecular cluster size, its growth, surface energies and increased clustering as protein ages. Growth most often occurs layer-by-layer resulting in faceted crystals. New molecular layer on crystal face is terminated by a step where molecular incorporation occurs. Quantitative data on the incorporation rate will be discussed. Rounded crystals with molecularly disordered interfaces will be explained. Defects in crystals compromise the x-ray diffraction resolution crucially needed to find the 3D atomic structure of biomolecules. The defects are immobile so that birth defects stay forever. All lattice defects known for inorganics are revealed in protein crystals. Contribution of molecular conformations to lattice disorder is important, but not studied. This contribution may be enhanced by stress field from other defects. Homologous impurities (e.g., dimers, acetylated molecules) are trapped more willingly by a growing crystal than foreign protein impurities. The trapped impurities induce internal stress eliminated in crystals exceeding a critical size (part of mni for ferritin, lysozyme). Lesser impurities are trapped from stagnant, as compared to the flowing, solution. Freezing may induce much more defects unless quickly amorphysizing intracrystalline water.

  5. Biological significance of PinX1 telomerase inhibitor in esophageal carcinoma treatment. (United States)

    Fan, Xiang-Kui; Yan, Rui-Hua; Geng, Xiang-Qun; Li, Jing-Shan; Chen, Xiang-Ming; Li, Jian-Zhe


    In the present study, to investigate the expression of PinX1 gene and its functional effects in human esophageal carcinoma (Eca)-109 cell line, expression vectors of human PinX1 (pEGFP-C3-PinX1) and its small interfering RNA (PinX1-FAM-siRNA) were constructed and transfected into Eca-109 cells using Lipofectamine 2000. Firstly, the mRNA expression level of PinX1 was examined using reverse transcription-polymerase chain reaction (RT-PCR). Once successful transfection was achieved, the effects on the mRNA level of human telomerase reverse transcriptase (hTERT), telomerase activity, cell proliferation and apoptosis were examined by semi-quantitative RT-PCR, stretch PCR, MTT assay and flow cytometry, respectively. Analysis of restriction and sequencing demonstrated that the recombining plasmids were successfully constructed. The results also indicated that transfection with pEGFP-C3-PinX1 and PinX1-FAM-siRNA into Eca-109 cells significantly increased PinX1 mRNA, decreased hTERT mRNA by 29.9% (Ptelomerase activity (Ptelomerase activity and cell apoptotic index were not altered. Exogenous PinX1 has been demonstrated to be highly expressed in human Eca. PinX1 can inhibit human telomerase activity and the expression of hTERT mRNA, reduce tumor cell growth and induce apoptosis. Notably, these inhibitory functions were inhibited by silencing PinX1 in Eca with PinX1-FAM-siRNA. PinX1 was successfully increased and decreased in the present study, demonstrating that it may be a potential telomerase activity inhibitor. As PinX1 is an endogenous telomerase inhibitor, it may be used as a novel tumor-targeted gene therapy.

  6. Comparison of Extension Orthosis Versus Percutaneous Pinning of the Distal Interphalangeal Joint for Closed Mallet Injuries. (United States)

    Renfree, Kevin J; Odgers, Ryan A; Ivy, Cynthia C


    We compared a static extension orthosis with percutaneous pinning of the distal interphalangeal joint (DIPJ) for treatment of closed mallet injuries. After receiving counsel about treatment options, 44 patients (25 women and 19 men; mean age, 57 years) freely chose orthosis and 18 patients (5 women and 13 men; mean age, 51 years) chose pinning. Both the extension orthosis and the pin remained in place for 6 weeks; the pin then was removed, and the care in both groups was transitioned to nighttime orthosis use for an additional 6 weeks. The patients in the pin group were allowed to immediately resume unrestricted activity postoperatively. The mean follow-up was 32 months in the orthosis group and 19 months in the pin group. Final residual extensor lag was better in the pin group (5 vs 10 degrees, P = 0.048). Improvement between the groups was in favor of percutaneous pinning (36 vs 17 degrees, P = 0.001). No correlation was seen between time to treatment (≤14 vs >14 days from injury) and final extensor lag in either group (P = 0.85). The final mean DIPJ flexion was 53 degrees for orthosis and 46 degrees for pinning. Among the patients, 93% of the orthosis group and 100% of the pin group said that they would choose the same treatment again. Both groups had a mean of 5 hand therapy visits during treatment. Two complications occurred in the orthosis group (5%) and 3 (17%) occurred in the pin group. Extension orthotics and pinning are both well-tolerated, effective treatments of mallet injury. The techniques produce satisfactory correction of extensor lag and have high patient satisfaction. Pinning allows better correction of DIPJ extensor lag and results in a smaller degree of final extensor lag. Pinning is more expensive and may result in more DIPJ stiffness (ie, loss of active flexion), but it may be justified in certain patients (eg, medical professionals, food service workers) who would have difficulty working with an orthosis.

  7. Ultralow Self-Doping in 2D Hybrid Perovskite Single Crystals

    KAUST Repository

    Peng, Wei


    Unintentional self-doping in semiconductors through shallow defects is detrimental to optoelectronic device performance. It adversely affects junction properties and it introduces electronic noise. This is especially acute for solution-processed semiconductors, including hybrid perovskites, which are usually high in defects due to rapid crystallization. Here, we uncover extremely low self-doping concentrations in single crystals of (C6H5C2H4NH3)2PbI4・(CH3NH3PbI3)n-1 (n=1, 2, and 3)—over three orders of magnitude lower than those of typical three-dimensional hybrid perovskites—by analyzing their conductivity behavior. We propose that crystallization of hybrid perovskites containing large organic cations suppresses defect formation and thus favors a low self-doping level. To exemplify the benefits of this effect, we demonstrate extraordinarily high light-detectivity (1013 Jones) in (C6H5C2H4NH3)2PbI4・(CH3NH3PbI3)n-1 photoconductors due to the reduced electronic noise, which makes them particularly attractive for the detection of weak light signals. Furthermore, the low self-doping concentration reduces the equilibrium charge carrier concentration in (C6H5C2H4NH3)2PbI4・(CH3NH3PbI3)n-1, advantageous in the design of p-i-n heterojunction solar cells by optimizing band alignment and promoting carrier depletion in the intrinsic perovskite layer, thereby enhancing charge extraction.

  8. Computational crystallization. (United States)

    Altan, Irem; Charbonneau, Patrick; Snell, Edward H


    Crystallization is a key step in macromolecular structure determination by crystallography. While a robust theoretical treatment of the process is available, due to the complexity of the system, the experimental process is still largely one of trial and error. In this article, efforts in the field are discussed together with a theoretical underpinning using a solubility phase diagram. Prior knowledge has been used to develop tools that computationally predict the crystallization outcome and define mutational approaches that enhance the likelihood of crystallization. For the most part these tools are based on binary outcomes (crystal or no crystal), and the full information contained in an assembly of crystallization screening experiments is lost. The potential of this additional information is illustrated by examples where new biological knowledge can be obtained and where a target can be sub-categorized to predict which class of reagents provides the crystallization driving force. Computational analysis of crystallization requires complete and correctly formatted data. While massive crystallization screening efforts are under way, the data available from many of these studies are sparse. The potential for this data and the steps needed to realize this potential are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Crystal structure of cafenstrole

    Directory of Open Access Journals (Sweden)

    Gihaeng Kang


    Full Text Available The title compound (systematic name: N,N-diethyl-3-mesitylsulfonyl-1H-1,2,4-triazole-1-carboxamide, C16H22N4O3S, is a triazole herbicide. The dihedral angle between the planes of the triazole and benzene ring planes is 88.14 (10°. In the crystal, C—H...O hydrogen bonds and weak C—H...π interactions link adjacent molecules, forming one-dimensional chains along the a axis.

  10. Study of the second magnetization peak and the pinning behaviour in Ba(Fe0.935Co0.065)2As2 pnictide superconductor (United States)

    Sundar, Shyam; Mosqueira, J.; Alvarenga, A. D.; Sóñora, D.; Sefat, A. S.; Salem-Sugui, S., Jr.


    Isothermal magnetic field dependence of magnetization and magnetic relaxation measurements were performed for the H\\parallel {{c}} axis on a single crystal of Ba(Fe0.935 Co0.065)2As2 pnictide superconductor having T c = 21.7 K. The second magnetization peak (SMP) for each isothermal M(H) was observed in a wide temperature range from T c to the lowest temperature of measurement (2 K). The magnetic field dependence of relaxation rate R(H), showed a peak (H spt) between H on (onset of SMP in M(H)) and H p (peak field of SMP in M(H)), which is likely to be related to a vortex-lattice structural phase transition, as suggested in the literature for a similar sample. In addition, the magnetic relaxation measured for magnetic fields near H spt showed some noise, which might be the signature of the structural phase transition of the vortex lattice. Analysis of the magnetic relaxation data using Maley’s criterion and the collective pinning theory suggested that the SMP in the sample was due to the collective (elastic) to plastic creep crossover, which was also accompanied by a rhombic to square vortex lattice phase transition. Analysis of the pinning force density suggested a single dominating pinning mechanism in the sample, which did not showing the usual δ {l} and δ {T}{{c}} nature of pinning. The critical current density (J c), estimated using the Bean critical state model, was found to be 5 × 105 A cm‑ 2 at 2 K in the zero magnetic field limit. Surprisingly, the maximum of the pinning force density was not responsible for the maximum value of the critical current density in the sample.

  11. Symmetry and disorder of the vitreous vortex lattice in overdoped BaFe2-xCoxAs2 : Indication for strong single-vortex pinning (United States)

    Inosov, D. S.; Shapoval, T.; Neu, V.; Wolff, U.; White, J. S.; Haindl, S.; Park, J. T.; Sun, D. L.; Lin, C. T.; Forgan, E. M.; Viazovska, M. S.; Kim, J. H.; Laver, M.; Nenkov, K.; Khvostikova, O.; Kühnemann, S.; Hinkov, V.


    The disordered flux line lattice in single crystals of the slightly overdoped BaFe2-xCoxAs2 ( x=0.19 , Tc=23K ) superconductor is studied by magnetization measurements, small-angle neutron scattering, and magnetic force microscopy (MFM). In the whole range of magnetic fields up to 9 T, vortex pinning precludes the formation of an ordered Abrikosov lattice. Instead, a vitreous vortex phase (vortex glass) with a short-range hexagonal order is observed. Statistical processing of MFM data sets lets us directly measure its radial and angular distribution functions and extract the radial correlation length ζ . In contrast to predictions of the collective pinning model, no increase in the correlated volume with the applied field is observed. Instead, we find that ζ decreases as (1.3±0.1)R1∝H-1/2 over four decades of the applied magnetic field, where R1 is the radius of the first coordination shell of the vortex lattice. Such universal scaling of ζ implies that the vortex pinning in iron arsenides remains strong even in the absence of static magnetism. This result is consistent with all the real and reciprocal-space vortex-lattice measurements in overdoped as-grown BaFe2-xCoxAs2 published to date and is thus sample independent. The failure of the collective pinning model suggests that the vortices remain in the single-vortex pinning limit even in high-magnetic fields up to 9 T.

  12. X-ray measurement with Pin type semiconductor detectors; Medicion de rayos X con detectores de semiconductor tipo PIN

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, Departamento de Electronica, C.P. 52045 Salazar, Estado de Mexico (Mexico)


    Here are presented the experimental results of the applications of Pin type radiation detectors developed in a National Institute of Nuclear Research (ININ) project, in the measurement of low energy gamma and X-rays. The applications were oriented mainly toward the Medical Physics area. It is planned other applications which are in process of implementation inside the National Institute of Nuclear Research in Mexico. (Author)

  13. Cell plate-restricted association of Arabidopsis dynamin related proteins and PIN auxin efflux carriers is required for PIN endocytic trafficking during cytokinesis.

    NARCIS (Netherlands)

    Mravec, J.; Petrasek, J.; Li, N.; Boeren, J.A.; Karlova, R.B.; Kitakura, S.; Naramoto, S.; Nodzynski, T.; Dhonukshe, P.B.; Vries, de S.C.; Zazimalova, E.; Friml, J.


    The polarized transport of the phytohormone auxin [1], which is crucial for the regulation of different stages of plant development [ [2] and [3] ], depends on the asymmetric plasma membrane distribution of the PIN-FORMED (PIN) auxin efflux carriers [4 A. Vieten, M. Sauer, P.B. Brewer and J. Friml,

  14. Optimal Weak Lensing Skewness Measurements


    Zhang, Tong-Jie; Pen, Ue-Li; Zhang, Pengjie; Dubinski, John


    Weak lensing measurements are entering a precision era to statistically map the distribution of matter in the universe. The most common measurement has been of the variance of the projected surface density of matter, which corresponds to the induced correlation in alignments of background galaxies. This measurement of the fluctuations is insensitive to the total mass content, like using waves on the ocean to measure its depths. But when the depth is shallow as happens near a beach, waves beco...

  15. Weak neutral-current interactions

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, R.M.


    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z/sup 0/ boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references. (JFP)

  16. [Muscle weakness in cerebral palsy]. (United States)

    Givon, Uri


    Over the last two decades, muscle weakness has been shown to be a major component of cerebral palsy (CP) pathology. Caused by multiple etiologies including variations in the muscle fiber type, pathologic motor unit function, co-contraction of agonists and antagonists, and muscle size and rigidity, weakness interferes with function and leads to limited function and participation. Muscle strength was found to be associated with walking ability and with functional scales. Children with CP were found to be weaker than typically developing children, and differences were found with respect to muscle groups in children with CP. Muscle weakness should be evaluated as objectively as possible to improve the quality of diagnosis and treatment. Manual muscle testing is not sufficient for evaluation, and instrumented muscle testing is validated in CP. Muscle strengthening is an important part of treatment of CP. Several methods of strengthening have been described. Muscle lengthening and other spasticity-modifying therapies have been shown to have a positive effect on muscle strength. Children who participated in muscle strengthening programs had a better quality of life and improved function.

  17. Systemic inflammatory response syndrome increases immobility-induced neuromuscular weakness. (United States)

    Fink, Heidrun; Helming, Marc; Unterbuchner, Christoph; Lenz, Andrea; Neff, Frauke; Martyn, J A Jeevendra; Blobner, Manfred


    Inflammation and immobility are comorbid etiological factors inducing muscle weakness in critically ill patients. This study establishes a rat model to examine the effect of inflammation and immobilization alone and in combination on muscle contraction, histology, and acetylcholine receptor regulation. Prospective, randomized, experimental study. Animal laboratory of a university hospital. Sprague-Dawley rats. To produce systemic inflammation, rats (n = 34) received three consecutive intravenous injections of Corynebacterium parvum on days 0, 4, and 8. Control rats (n = 21) received saline. Both groups were further divided to have one hind limb either immobilized by pinning of knee and ankle joints or sham-immobilized (surgical leg). The contralateral nonsurgical leg of each animal served as control (nonsurgical leg). After 12 days, body weight and muscle mass were significantly reduced in all C. parvum animals compared with saline-injected rats. Immobilization led to local muscle atrophy. Normalized to muscle mass, tetanic contraction was reduced in the surgical leg after immobilization (7.64 +/- 1.91 N/g) and after inflammation (8.71 +/- 2.0 N/g; both p immobilization and saline injection, 11.03 +/- 2.26 N/g). Histology showed an increase in inflammatory cells in all C. parvum-injected animals. Immobilization in combination with C. parvum injection had an additive effect on inflammation. Acetylcholine receptors were increased in immobilized muscles and in all muscles of C. parvum-injected animals. The muscle weakness in critically ill patients can be replicated in our novel rat model. Inflammation and immobilization independently lead to muscle weakness.

  18. Colloids in external electric and magnetic fields: Colloidal crystals, pinning, chain formation, and electrokinetics (United States)

    Zhao, J.; Papadopoulos, P.; Roth, M.; Dobbrow, C.; Roeben, E.; Schmidt, A.; But, H.-J. t.; Auernhammer, G. K.; Vollmer, D.


    The motion of dilute and concentrated dispersions of colloids by external electric or magnetic fields is discussed. Electrokinetics is studied for colloids in confinement, where the confining walls can be flat or rough. As an example for a rough wall superhydrophobic surfaces are chosen. It is shown that the reduced friction at the water-air interface is insufficient to enhance electro-osmosis. Magnetic particles are pulled through a crystalline matrix formed by nonmagnetic colloids to investigate local melting and recrystallization of a crystalline matrix. The average strain field is calculated and the reorganization processes are compared to those induced by shear fields. Using single domain, magnetically blocked particles of different shape and surface characteristics, the interplay between particles, their environment and an external field is investigated.

  19. Completely continuous and weakly completely continuous abstract ...

    Indian Academy of Sciences (India)

    if the operator ρa of right multiplication by a is compact (weakly compact, respectively). An algebra A is called right completely continuous (right weakly completely continuous) if any element a ∈ A is right completely continuous (right weakly completely con- tinuous, respectively). Left completely continuous (left weakly ...

  20. [Biomechanical study of percutaneous pinning as the treatment of proximal humerus fractures]. (United States)

    Jiang, Chun-yan; Wang, Man-yi; Rong, Guo-wei


    To investigate the influence on fracture stability by different pin construct during percutaneous pinning for the treatment of proximal humerus fractures. Eighteen pairs (36) adult fresh-frozen humeri were match-paired and divided into 4 groups. Dual-energy bone density scan had been used in order to rule out the influence by different degrees of osteoporosis of the cadaver. Two-part surgical neck fracture model was carried out unanimously in all 36 humeri. Four terminal threaded pins (2.5 mm in diameter) were used in fixation for all specimen. Parallel type pinning (box type) were carried out in 2 groups and convergent type pinning (fan shape) in the other 2 groups. Instron5566 biomechanical tester was applied in determining both anti-shear and anti-torsion ultimate load of each specimen. There was no statistical difference between parallel pin construct and convergent construct in regard of anti-shear resistance (P = 0.73). But by mean of anti-torsion resistance, the parallel construct had significant advantage over the convergent construct (P = 0.04). According to our biomechanical data, parallel pin construct seems to have better torsional stability. We suggest that parallel pin fixation should be applied whenever possible. Convergent pin construct should be considered when parallel construct is not possible or the distance between pins are too small (< 1 cm).

  1. Pin1 enhances adipocyte differentiation by positively regulating the transcriptional activity of PPARγ. (United States)

    Han, Younho; Lee, Sung Ho; Bahn, Minjin; Yeo, Chang-Yeol; Lee, Kwang Youl


    Pin1 is a peptidylprolyl cis/trans isomerase and it has a unique enzymatic activity of catalyzing isomerization of the peptide bond between phospho-serine/threonine and proline. Through the conformational change of its substrates, Pin1 regulates diverse biological processes including adipogenesis. In mouse embryonic fibroblasts and 3T3-L1 preadipocytes, overexpression of Pin1 enhances adipocyte differentiation whereas inhibition of Pin1 activity suppresses it. However, the precise functions of Pin1 during adipogenesis are not clear. In the present study, we investigated the potential targets of Pin1 during adipogenesis. We found that Pin1 interacts directly with and regulates the transcriptional activity of PPARγ, a key regulator of adipogenesis. In addition, ERK activity and Ser273 of PPARγ, a potential ERK phosphorylation target site, are important for the regulation of PPARγ function by Pin1 in 3T3-L1 cells. Taken together our results suggest a novel regulatory mechanism of Pin1 during adipogenesis, in which Pin1 enhances adipocyte differentiation by regulating the function of PPARγ. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Excessive Cellular S-nitrosothiol Impairs Endocytosis of Auxin Efflux Transporter PIN2

    Directory of Open Access Journals (Sweden)

    Min Ni


    Full Text Available S-nitrosoglutathione reductase (GSNOR1 is the key enzyme that regulates cellular levels of S-nitrosylation across kingdoms. We have previously reported that loss of GSNOR1 resulted in impaired auxin signaling and compromised auxin transport in Arabidopsis, leading to the auxin-related morphological phenotypes. However, the molecular mechanism underpinning the compromised auxin transport in gsnor1-3 mutant is still unknown. Endocytosis of plasma-membrane (PM-localized efflux PIN proteins play critical roles in auxin transport. Therefore, we investigate whether loss of GSNOR1 function has any effects on the endocytosis of PIN-FORMED (PIN proteins. It was found that the endocytosis of either the endogenous PIN2 or the transgenically expressed PIN2-GFP was compromised in the root cells of gsnor1-3 seedlings relative to Col-0. The internalization of PM-associated PIN2 or PIN2-GFP into Brefeldin A (BFA bodies was significantly reduced in gsnor1-3 upon BFA treatment in a manner independent of de novo protein synthesis. In addition, the exogenously applied GSNO not only compromised the endocytosis of PIN2-GFP but also inhibited the root elongation in a concentration-dependent manner. Taken together, our results indicate that, besides the reduced PIN2 level, one or more compromised components in the endocytosis pathway could account for the reduced endocytosis of PIN2 in gsnor1-3.

  3. A three-dimensional pin-wise analysis for CEA ejection accident

    Energy Technology Data Exchange (ETDEWEB)

    Park, Guen-Tae; Park, Min-Ho; Park, Jin-Woo; Um, Kil-Sup; Choi, Tong-Soo [KEPCO NF, Daejeon (Korea, Republic of)


    The ejection of a control element assembly (CEA) with high reactivity worth causes the sudden insertion of reactivity into the core. Immediately after the CEA ejection, the nuclear power of the reactor dramatically increases in an exponential behavior until the doppler effect becomes important and turns the reactivity balance and power down to lower levels. The 3-D CEA ejection analysis methodology has been developed using the multi-dimensional code coupling system, CHASER, which couples three dimensional core neutron kinetics code ASTRA, subchannel analysis code THALES, and fuel performance analysis code FROST using message passing interface (MPI). This paper presents the pin-by-pin level analysis result with the 3-D CEA ejection analysis methodology using the CHASER. The pin-by-pin level analysis consists of DNBR, enthalpy and Pellet/Clad Mechanical Interaction (PCMI) analysis. All the evaluations are simulated for APR1400 plant loaded with PLUS7 fuel. In this paper, the pin-by-pin analysis using the multidimensional core transient code, CHASER, is presented with respect to enthalpy, DNBR and PCMI for APR1400 plant loaded with PLUS7 fuel. For the pin-by-pin enthalpy and DNBR analysis, the quarter core for HFP case or 15 - 20 assemblies around the most severe assembly for part powers or HZP cases are selected. And PCMI calculation is performed for all the rods in the whole core during a conservative time period. The pin-by-pin analysis results show that the regulatory guidelines of CEA ejection accident are satisfied.

  4. The prolyl isomerase Pin1 modulates development of CD8+ cDC in mice. (United States)

    Barberi, Theresa J; Dunkle, Alexis; He, You-Wen; Racioppi, Luigi; Means, Anthony R


    Pin1 has previously been described to regulate cells that participate in both innate and adaptive immunity. Thus far, however, no role for Pin1 has been described in modulating conventional dendritic cells, innate antigen presenting cells that potently activate naïve T cells, thereby bridging innate and adaptive immune responses. When challenged with LPS, Pin1-null mice failed to accumulate spleen conventional dendritic cells (cDC). Analysis of steady-state spleen DC populations revealed that Pin1-null mice had fewer CD8+ cDC. This defect was recapitulated by culturing Pin1-null bone marrow with the DC-instructive cytokine Flt3 Ligand. Additionally, injection of Flt3 Ligand for 9 days failed to induce robust expansion of CD8+ cDC in Pin1-null mice. Upon infection with Listeria monocytogenes, Pin1-null mice were defective in stimulating proliferation of adoptively transferred WT CD8+ T cells, suggesting that decreases in Pin1 null CD8+ cDC may affect T cell responses to infection in vivo. Finally, upon analyzing expression of proteins involved in DC development, elevated expression of PU.1 was detected in Pin1-null cells, which resulted from an increase in PU.1 protein half-life. We have identified a novel role for Pin1 as a modulator of CD8+ cDC development. Consistent with reduced numbers of CD8+ cDC in Pin1-null mice, we find that the absence of Pin1 impairs CD8+ T cell proliferation in response to infection with Listeria monocytogenes. These data suggest that, via regulation of CD8+ cDC production, Pin1 may serve as an important modulator of adaptive immunity.

  5. Characteristic measurement for femtosecond laser pulses using a GaAs PIN photodiode as a two-photon photovoltaic receiver (United States)

    Chen, Junbao; Xia, Wei; Wang, Ming


    Photodiodes that exhibit a two-photon absorption effect within the spectral communication band region can be useful for building an ultra-compact autocorrelator for the characteristic inspection of optical pulses. In this work, we develop an autocorrelator for measuring the temporal profile of pulses at 1550 nm from an erbium-doped fiber laser based on the two-photon photovoltaic (TPP) effect in a GaAs PIN photodiode. The temporal envelope of the autocorrelation function contains two symmetrical temporal side lobes due to the third order dispersion of the laser pulses. Moreover, the joint time-frequency distribution of the dispersive pulses and the dissimilar two-photon response spectrum of GaAs and Si result in different delays for the appearance of the temporal side lobes. Compared with Si, GaAs displays a greater sensitivity for pulse shape reconstruction at 1550 nm, benefiting from the higher signal-to-noise ratio of the side lobes and the more centralized waveform of the autocorrelation trace. We also measure the pulse width using the GaAs PIN photodiode, and the resolution of the measured full width at half maximum of the TPP autocorrelation trace is 0.89 fs, which is consistent with a conventional second-harmonic generation crystal autocorrelator. The GaAs PIN photodiode is shown to be highly suitable for real-time second-order autocorrelation measurements of femtosecond optical pulses. It is used both for the generation and detection of the autocorrelation signal, allowing the construction of a compact and inexpensive intensity autocorrelator.

  6. Growth and Characterization on PMN-PT-Based Single Crystals

    Directory of Open Access Journals (Sweden)

    Jian Tian


    Full Text Available Lead magnesium niobate—lead titanate (PMN-PT single crystals have been successfully commercialized in medical ultrasound imaging. The superior properties of PMN-PT crystals over the legacy piezoelectric ceramics lead zirconate titanate (PZT enabled ultrasound transducers with enhanced imaging (broad bandwidth and improved sensitivity. To obtain high quality and relatively low cost single crystals for commercial production, PMN-PT single crystals were grown with modified Bridgman method, by which crystals were grown directly from stoichiometric melt without flux. For ultrasound imaging application, [001] crystal growth is essential to provide uniform composition and property within a crystal plate, which is critical for transducer performance. In addition, improvement in crystal growth technique is under development with the goals of improving the composition homogeneity along crystal growth direction and reducing unit cost of crystals. In recent years, PIN-PMN-PT single crystals have been developed with higher de-poling temperature and coercive field to provide improved thermal and electrical stability for transducer application.

  7. Protecting weak measurements against systematic errors


    Pang, Shengshi; Alonso, Jose Raul Gonzalez; Brun, Todd A.; Jordan, Andrew N.


    In this work, we consider the systematic error of quantum metrology by weak measurements under decoherence. We derive the systematic error of maximum likelihood estimation in general to the first-order approximation of a small deviation in the probability distribution, and study the robustness of standard weak measurement and postselected weak measurements against systematic errors. We show that, with a large weak value, the systematic error of a postselected weak measurement when the probe u...

  8. Gossip and Distributed Kalman Filtering: Weak Consensus Under Weak Detectability (United States)

    Kar, Soummya; Moura, José M. F.


    The paper presents the gossip interactive Kalman filter (GIKF) for distributed Kalman filtering for networked systems and sensor networks, where inter-sensor communication and observations occur at the same time-scale. The communication among sensors is random; each sensor occasionally exchanges its filtering state information with a neighbor depending on the availability of the appropriate network link. We show that under a weak distributed detectability condition: 1. the GIKF error process remains stochastically bounded, irrespective of the instability properties of the random process dynamics; and 2. the network achieves \\emph{weak consensus}, i.e., the conditional estimation error covariance at a (uniformly) randomly selected sensor converges in distribution to a unique invariant measure on the space of positive semi-definite matrices (independent of the initial state.) To prove these results, we interpret the filtered states (estimates and error covariances) at each node in the GIKF as stochastic particles with local interactions. We analyze the asymptotic properties of the error process by studying as a random dynamical system the associated switched (random) Riccati equation, the switching being dictated by a non-stationary Markov chain on the network graph.

  9. Finite size and geometrical non-linear effects during crack pinning by heterogeneities: An analytical and experimental study (United States)

    Vasoya, Manish; Unni, Aparna Beena; Leblond, Jean-Baptiste; Lazarus, Veronique; Ponson, Laurent


    Crack pinning by heterogeneities is a central toughening mechanism in the failure of brittle materials. So far, most analytical explorations of the crack front deformation arising from spatial variations of fracture properties have been restricted to weak toughness contrasts using first order approximation and to defects of small dimensions with respect to the sample size. In this work, we investigate the non-linear effects arising from larger toughness contrasts by extending the approximation to the second order, while taking into account the finite sample thickness. Our calculations predict the evolution of a planar crack lying on the mid-plane of a plate as a function of material parameters and loading conditions, especially in the case of a single infinitely elongated obstacle. Peeling experiments are presented which validate the approach and evidence that the second order term broadens its range of validity in terms of toughness contrast values. The work highlights the non-linear response of the crack front to strong defects and the central role played by the thickness of the specimen on the pinning process.

  10. Weak polyelectrolytes in Confined Geometries (United States)

    Whitmer, Jonathan K.; Rathee, Vikramjit S.; Sikora, Benjamin

    Crucial to the behavior of recently designed charge-rejection and mosaic membranes are the conformations of polyelectrolyte brushes and oligomeric grafts used to control the membranes' surface charge. The use of pH-tunable weak polyelectrolytes with associative interactions enables fine tuning of material transport properties. Here, we apply constant-pH molecular dynamics along with free energy sampling algorithms to understand the subtle tug-of-war between pH, salt concentrations, and solvation forces in confined systems, and determine how each of these effects alters transport within the system. We further discuss the implications of our findings for the design of electrolyte separation membranes.

  11. Domain-growth kinetics and aspects of pinning: A Monte Carlo simulation study

    DEFF Research Database (Denmark)

    Castán, T.; Lindgård, Per-Anker


    transformations, surface reconstructions, and magnetic transitions. No external impurities are introduced, but the model has a number of intrinsic, annealable pinning mechanisms, which strongly influences the growth kinetics. It allows a study of pinning effects of three kinds: (a) pinning of domain walls...... by defects-this is found in effect to stop the growth, forming a metastable state at low temperatures T; (b) temporary pinning by stacking faults or zero-curvature domain walls; and (c) topological pinnings, which are also found to be temporary. These just slow down the growth. The pinning mechanisms...... and the depinning probability at higher temperatures are studied. The excess energy of the domain walls is found to follow an algebraic decay DELTA-E(t) = E(M) + At(-n), with E(M) = 0 for cases (b) and (c) and decaying toward a metastable state with energy E(M) not-equal-to 0 for case (a). The exponent is found...

  12. Crystal Dislocations

    Directory of Open Access Journals (Sweden)

    Ronald W. Armstrong


    Full Text Available Crystal dislocations were invisible until the mid-20th century although their presence had been inferred; the atomic and molecular scale dimensions had prevented earlier discovery. Now they are normally known to be just about everywhere, for example, in the softest molecularly-bonded crystals as well as within the hardest covalently-bonded diamonds. The advent of advanced techniques of atomic-scale probing has facilitated modern observations of dislocations in every crystal structure-type, particularly by X-ray diffraction topography and transmission electron microscopy. The present Special Issue provides a flavor of their ubiquitous presences, their characterizations and, especially, their influence on mechanical and electrical properties.

  13. GaN-based PIN alpha particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wang Guo [Peking University, Shenzhen Graduate School, Guangdong Shenzhen 518055 (China); Peking University, Beijing, 100871 (China); Fu Kai; Yao Changsheng [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Science, Jiangsu Suzhou 215123 (China); Su Dan; Zhang Guoguang [China Institute of Atomic Energy, Beijing 102413 (China); Wang Jinyan [Peking University, Beijing, 100871 (China); Lu Min, E-mail: [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Science, Jiangsu Suzhou 215123 (China)


    GaN-based PIN alpha particle detectors are studied in this article. The electrical properties of detectors have been investigated, such as current-voltage (I-V) and capacitance-voltage (C-V). The reverse current of all detectors is in nA range applied at 30 V, which is suitable for detector operation. The charge collection efficiency (CCE) is measured to be approximately 80% but the energy resolution is calculated to be about 40% mostly because the intrinsic layer is not sufficiently thick enough.

  14. Gas Gangrene as a Result of Femoral Traction Pin Placement

    Directory of Open Access Journals (Sweden)

    Benjamin C. Taylor


    Full Text Available Treatment of adult femoral shaft fractures typically involves operative stabilization with intramedullary implants, external fixation, or a plate and screw construct. However, when stabilization is delayed for any reason, use of a traction pin is recommended to stabilize the fracture, prevent significant shortening, as well as to help with pain control. In this paper, we present the rare complication of a severe gas gangrene infection caused by Clostridium perfringens that led to several amputations and ultimately death. We also discuss risks of temporary skeletal traction and techniques to overcome the morbidity of such a procedure.

  15. Current Kink and Capacitance Frequency Dispersion in Silicon PIN Photodiodes (United States)

    Guo, Xia; Feng, Yajie; Liu, Qiaoli; Wang, Huaqiang; Li, Chong; Hu, Zonghai; He, Xiaoying


    Silicon PIN photodiodes in the visible wavelength range have been widely applied in aerospace, defense, security, medical, and scientific instruments because of their high sensitivity and low cost. In this paper, the phenomena of the current kink and the capacitance frequency dispersion are observed. Contamination at the p-type Ohmic contact interface is proposed to explain the current kink effect and capacitance frequency dispersion, according to the temperature-dependent I-V measurement results in which trap-assisted tunneling process demonstrated.

  16. Displacement Damage Effects in Pinned Photodiode CMOS Image Sensors


    Virmontois, Cédric; Goiffon, Vincent; Corbière, Franck; Magnan, Pierre; Girard, Sylvain; Bardoux, Alain


    This paper investigates the effects of displacement damage in Pinned Photodiode (PPD) CMOS Image Sensors (CIS) using proton and neutron irradiations. The DDD ranges from 12 TeV/g to ${1.2 times 10^{6}}$ TeV/g. Particle fluence up to $5 times 10^{14}$ $^{-2}$ is investigated to observe electro-optic degradation in harsh environments. The dark current is also investigated and it would appear that it is possible to use the dark current spectroscopy in PPD CIS. The dark current random telegr...

  17. Liquid crystal tunable photonic crystal dye laser

    DEFF Research Database (Denmark)

    Buss, Thomas; Christiansen, Mads Brøkner; Smith, Cameron


    We present a dye-doped liquid crystal laser using a photonic crystal cavity. An applied electric field to the liquid crystal provides wavelength tunability. The photonic crystal enhances resonant interaction with the gain medium.......We present a dye-doped liquid crystal laser using a photonic crystal cavity. An applied electric field to the liquid crystal provides wavelength tunability. The photonic crystal enhances resonant interaction with the gain medium....

  18. PinX1 regulation of telomerase activity and apoptosis in nasopharyngeal carcinoma cells

    Directory of Open Access Journals (Sweden)

    Lai Xiao-Fen


    Full Text Available Abstract Background Human interacting protein X1 (PinX1 has been identified as a critical telomerase inhibitor and proposed to be a putative tumor suppressor gene. Loss of PinX1 has been found in a large variety of malignancies, however, its function in inhibiting telomerase activity of tumor cells is not well documented. Here we show that PinX1 is essential for down-regulation telomerase activity of nasopharyngeal carcinoma. Methods Expression vectors of human PinX1 (pEGFP-C3-PinX1 and its small interfering RNA (PinX1-FAM-siRNA were constructed and transfected into NPC. Their effects on mRNA of telomerase catalytic subunit (hTERT, telomerase activity, cell proliferation, cell migration, wound healing, cell cycles and apoptosis were examined using semi-quantitative RT-PCR, stretch PCR, MTT assay, Transwell, scratch assay and flow cytometry, respectively. Results Transfection of pEGFP-C3-PinX1 and PinX1-FAM-siRNA increased and reduced PinX1 mRNA by 1.6-fold and 70%, respectively. Over-expression of PinX1 decreased hTERT mRNA by 21%, reduced telomerase activity, inhibited cell growth, migration and wound healing ability, arrested cells in G0/G1 phase, and increased apoptotic index. In contrast, down-regulation of PinX1 did not alter the above characteristics. Conclusions PinX1 may play important roles in NPC proliferation, migration and apoptosis and has application potential in tumor-targeted gene therapy.

  19. Weak lensing and cosmological investigation

    CERN Document Server

    Acquaviva, V


    In the last few years the scientific community has been dealing with the challenging issue of identifying the dark energy component. We regard weak gravitational lensing as a brand new, and extremely important, tool for cosmological investigation in this field. In fact, the features imprinted on the cosmic microwave background radiation by the lensing from the intervening distribution of matter represent a pretty unbiased estimator, and can thus be used for putting constraints on different dark energy models. This is true in particular for the magnetic-type B-modes of CMB polarization, whose unlensed spectrum at large multipoles (l approximately=1000) is very small even in presence of an amount of gravitational waves as large as currently allowed by the experiments: therefore, on these scales the lensing phenomenon is the only responsible for the observed power, and this signal turns out to be a faithful tracer of the dark energy dynamics. We first recall the formal apparatus of the weak lensing in extended t...

  20. Time—periodic weak solutions

    Directory of Open Access Journals (Sweden)

    Eliana Henriques de Brito


    Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.

  1. Political corruption and weak state

    Directory of Open Access Journals (Sweden)

    Stojiljković Zoran


    Full Text Available The author starts from the hypothesis that it is essential for the countries of the region to critically assess the synergy established between systemic, political corruption and a selectively weak, “devious” nature of the state. Moreover, the key dilemma is whether the expanded practice of political rent seeking supports the conclusion that the root of all corruption is in the very existence of the state - particularly in excessive, selective and deforming state interventions and benefits that create a fertile ground for corruption? The author argues that the destructive combination of weak government and rampant political corruption is based on scattered state intervention, while also rule the parties cartel in the executive branch subordinate to parliament, the judiciary and the police. Corrupt exchange takes place with the absence of strong institutional framework and the precise rules of the political and electoral games, control of public finances and effective political and anti-monopoly legislation and practice included. Exit from the current situation can be seen in the realization of effective anti­corruption strategy that integrates preventive and repressive measures and activities and lead to the establishment of principles of good governance. [Projekat Ministarstva nauke Republike Srbije, br. 179076: Politički identitet Srbije u regionalnom i globalnom kontekstu

  2. Enquiry into the Topology of Plasma Membrane-Localized PIN Auxin Transport Components. (United States)

    Nodzyński, Tomasz; Vanneste, Steffen; Zwiewka, Marta; Pernisová, Markéta; Hejátko, Jan; Friml, Jiří


    Auxin directs plant ontogenesis via differential accumulation within tissues depending largely on the activity of PIN proteins that mediate auxin efflux from cells and its directional cell-to-cell transport. Regardless of the developmental importance of PINs, the structure of these transporters is poorly characterized. Here, we present experimental data concerning protein topology of plasma membrane-localized PINs. Utilizing approaches based on pH-dependent quenching of fluorescent reporters combined with immunolocalization techniques, we mapped the membrane topology of PINs and further cross-validated our results using available topology modeling software. We delineated the topology of PIN1 with two transmembrane (TM) bundles of five α-helices linked by a large intracellular loop and a C-terminus positioned outside the cytoplasm. Using constraints derived from our experimental data, we also provide an updated position of helical regions generating a verisimilitude model of PIN1. Since the canonical long PINs show a high degree of conservation in TM domains and auxin transport capacity has been demonstrated for Arabidopsis representatives of this group, this empirically enhanced topological model of PIN1 will be an important starting point for further studies on PIN structure-function relationships. In addition, we have established protocols that can be used to probe the topology of other plasma membrane proteins in plants. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Enhanced Flux Pinning in Laser Ablated YBCO:BaTiO3 Nanocomposite Thin Film (United States)

    Jha, Alok K.; Khare, Neeraj; Pinto, R.


    The effect of incorporation of BaTiO3 (BTO) nanoparticles on the flux pinning properties of laser deposited YBCO:BTO thin films has been studied. Substantial increase in critical current density (JC) and pinning force density of the nanocomposite thin films was observed. The study of temperature and field dependence of JC of YBCO and YBCO:BTO thin films indicates similar type of pinning. The lattice mismatch between YBCO and BTO seems to introduce more defects resulting in improved flux pinning properties.

  4. Effects of Pin1 loss in HdhQ111 knock-in mice

    Directory of Open Access Journals (Sweden)

    Elena eAgostoni


    Full Text Available Huntington’s disease (HD is a fatal, dominantly inherited, neurodegenerative disorder due to a pathological expansion of the CAG repeat in the coding region of the HTT gene. In the quest for understanding the molecular basis of neurodegeneration, we have previously demonstrated that the prolyl isomerase Pin1 plays a crucial role in mediating p53-dependent apoptosis triggered by mutant huntingtin (mHtt in vitro. To assess the effects of the lack of Pin1 in vivo, we have bred Pin1 knock-out mice with HdhQ111 knock-in mice, a genetically precise model of HD. We show that Pin1 genetic ablation modifies a portion of HdhQ111 phenotypes in a time-dependent fashion. As an early event, Pin1 activity reduces the DNA damage response. In midlife mice, by taking advantage of next-generation sequencing technology, we show that Pin1 activity modulates a portion of the alterations triggered by mHtt, extending the role of Pin1 to two additional HdhQ111 phenotypes: the unbalance in the synthesis/concentration of hormones, as well as the alteration of Wnt/β-catenin signaling. In aging animals, Pin1 significantly increases the number of mHtt-positive nuclear inclusions while it reduces gliosis. In summary, this work provides further support for a role of Pin1 in HD pathogenesis.

  5. Effects of Pin1 Loss in HdhQ111 Knock-in Mice (United States)

    Agostoni, Elena; Michelazzi, Silvia; Maurutto, Marta; Carnemolla, Alisia; Ciani, Yari; Vatta, Paolo; Roncaglia, Paola; Zucchelli, Silvia; Leanza, Giampiero; Mantovani, Fiamma; Gustincich, Stefano; Santoro, Claudio; Piazza, Silvano; Del Sal, Giannino; Persichetti, Francesca


    Huntington’s disease (HD) is a fatal, dominantly inherited, neurodegenerative disorder due to a pathological expansion of the CAG repeat in the coding region of the HTT gene. In the quest for understanding the molecular basis of neurodegeneration, we have previously demonstrated that the prolyl isomerase Pin1 plays a crucial role in mediating p53-dependent apoptosis triggered by mutant huntingtin (mHtt) in vitro. To assess the effects of the lack of Pin1 in vivo, we have bred Pin1 knock-out mice with HdhQ111 knock-in mice, a genetically precise model of HD. We show that Pin1 genetic ablation modifies a portion of HdhQ111 phenotypes in a time-dependent fashion. As an early event, Pin1 activity reduces the DNA damage response (DDR). In midlife mice, by taking advantage of next-generation sequencing technology, we show that Pin1 activity modulates a portion of the alterations triggered by mHtt, extending the role of Pin1 to two additional HdhQ111 phenotypes: the unbalance in the “synthesis/concentration of hormones”, as well as the alteration of “Wnt/β-catenin signaling”. In aging animals, Pin1 significantly increases the number of mHtt-positive nuclear inclusions while it reduces gliosis. In summary, this work provides further support for a role of Pin1 in HD pathogenesis. PMID:27199664

  6. Functionally different PIN proteins control auxin flux during bulbil development in Agave tequilana. (United States)

    Abraham Juárez, María Jazmín; Hernández Cárdenas, Rocío; Santoyo Villa, José Natzul; O'Connor, Devin; Sluis, Aaron; Hake, Sarah; Ordaz-Ortiz, José; Terry, Leon; Simpson, June


    In Agave tequilana, reproductive failure or inadequate flower development stimulates the formation of vegetative bulbils at the bracteoles, ensuring survival in a hostile environment. Little is known about the signals that trigger this probably unique phenomenon in agave species. Here we report that auxin plays a central role in bulbil development and show that the localization of PIN1-related proteins is consistent with altered auxin transport during this process. Analysis of agave transcriptome data led to the identification of the A. tequilana orthologue of PIN1 (denoted AtqPIN1) and a second closely related gene from a distinct clade reported as 'Sister of PIN1' (denoted AtqSoPIN1). Quantitative real-time reverse transcription-PCR (RT-qPCR) analysis showed different patterns of expression for each gene during bulbil formation, and heterologous expression of the A. tequilana PIN1 and SoPIN1 genes in Arabidopsis thaliana confirmed functional differences between these genes. Although no free auxin was detected in induced pedicel samples, changes in the levels of auxin precursors were observed. Taken as a whole, the data support the model that AtqPIN1 and AtqSoPIN1 have co-ordinated but distinct functions in relation to auxin transport during the initial stages of bulbil formation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  7. Phylogeny and molecular evolution analysis of PIN-FORMED 1 in angiosperm. (United States)

    Wang, Pengkai; Cheng, Tielong; Wu, Shuang; Zhao, Fangfang; Wang, Guangping; Yang, Liming; Lu, Mengzhu; Chen, Jinhui; Shi, Jisen


    PIN-FORMED 1 (PIN1) is an important secondary transporter and determines the direction of intercellular auxin flow. As PIN1 performs the conserved function of auxin transport, it is expected that the sequence and structure of PIN1 is conserved. Therefore, we hypothesized that PIN1 evolve under pervasive purifying selection in the protein-coding sequences in angiosperm. To test this hypothesis, we performed detailed evolutionary analyses of 67 PIN1 sequences from 35 angiosperm species. We found that the PIN1 sequences are highly conserved within their transmembrane regions, part of their hydrophilic regions. We also found that there are two or more PIN1 copies in some of these angiosperm species. PIN1 sequences from Poaceae and Brassicaceae are representative of the modern clade. We identified 12 highly conserved motifs and a significant number of family-specific sites within these motifs. One family-specific site within Motif 11 shows a different residue between monocots and dicots, and is functionally critical for the polarity of PIN1. Likewise, the function of PIN1 appears to be different between monocots and dicots since the phenotype associated with PIN1 overexpression is opposite between Arabidopsis and rice. The evolution of angiosperm PIN1 protein-coding sequences appears to have been primarily driven by purifying selection, but traces of positive selection associated with sequences from certain families also seem to be present. We verified this observation by calculating the numbers of non-synonymous and synonymous changes on each branch of a phylogenetic tree. Our results indicate that the evolution of angiosperm PIN1 sequences involve strong purifying selection. In addition, our results suggest that the conserved sequences of PIN1 derive from a combination of the family-specific site variations and conserved motifs during their unique evolutionary processes, which is critical for the functional integrity and stability of these auxin transporters

  8. Modeling and adaptive pinning synchronization control for a chaotic-motion motor in complex network (United States)

    Zhu, Darui; Liu, Chongxin; Yan, Bingnan


    We introduce a chaos model for a permanent-magnet synchronous motor and construct a coupled chaotic motor in a complex dynamic network using the Newman-Watts small-world network algorithm. We apply adaptive pinning control theory for complex networks to obtain suitable adaptive feedback gain and the number of nodes to be pinned. Nodes of low degree are pinned to realize global asymptotic synchronization in the complex network. The proposed adaptive pinning controller is added to the complex motor network for simulation and verification.

  9. Introduction of artificial pinning centre in {open_quotes}Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}{close_quotes} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Majewski, P.; Aldinger, F. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany); Elschner, S. [Hoechst AG, Frankfurt am Main (Germany)] [and others


    Considering the phase equilibrium diagram of the system Bi{sub 2}O{sub 3}-SrO-CaO-CuO, single phase {open_quotes}Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}{close_quotes} ceramics have been transformed by a simple annealing procedure into multi phase samples. The transformation results in the formation of second phases and in an increase of the intra grain critical current density at 1 T of five times. This increase is believed to express improved pinning properties of the superconducting crystals. The prepared pinning centres are believed to be e.g. coherent precipitates (Guinier-Preston-zones) within the superconducting crystals.

  10. Synthesis and characterization of two manganese(II) complexes containing di(4-pyridyl)sulfide (4-DPS) ligand: The effects of the counter ion and of the weak non-covalent interactions in the crystal structures of [Mn(4-DPS) 4(H 2O) 2](ClO 4) 2·H 2O and {[Mn(4-DPS) 2(NCS) 2] ·2H 2O} n (United States)

    Marinho, Maria Vanda; Yoshida, Maria Irene; Krambrock, Klaus; De Oliveira, Luiz Fernando C.; Diniz, Renata; Machado, Flávia C.


    From the reaction between the metallic precursor Mn(ClO 4) 2·6H 2O and the flexible ligand di(4-pyridyl)sulfide (4-DPS) a mononuclear complex [Mn(4-DPS) 4(H 2O) 2](ClO 4) 2·H 2O ( 1) was obtained, while the reaction of MnCl 2·4H 2O with 4-DPS and KSCN afforded a neutral 1-D coordination polymer namely {[Mn(4-DPS) 2(NCS) 2] ·2H 2O} n ( 2). Compounds ( 1) and ( 2) were characterized by means of elemental analysis, thermal analysis (TG/DTA), vibrational (IR and Raman) and electron paramagnetic resonance (EPR) spectroscopies. Additionally, single-crystal X-ray diffraction analysis shows that in ( 1) the 4-DPS ligand acts in the monodentate coordination mode while in ( 2) it exhibits bridging coordination mode. The crystal structure of both compounds shows that each Mn 2+ adopts a distorted octahedral geometry in which the equatorial planes contain four nitrogen atoms from different 4-DPS ligands. In ( 1), the axial positions are occupied by two oxygen atoms from two water molecules and in ( 2) by two other nitrogen atoms from two isothiocyanate groups. The supramolecular array observed in ( 1) was achieved through hydrogen-bonding and π-π interactions and in ( 2) the 1-D doubled stranded polymeric chain is extended by metal-ligand interaction. EPR spectra for both compounds are consistent with the X-ray structures containing isolated Mn 2+ ions in distorted octahedral arrangements with very weak anti-ferromagnetic coupling.

  11. Hydrophobic pinning with copper nanowhiskers leads to bactericidal properties.

    Directory of Open Access Journals (Sweden)

    Ajay Vikram Singh

    Full Text Available The considerable morbidity associated with hospitalized patients and clinics in developed countries due to biofilm formation on biomedical implants and surgical instruments is a heavy economic burden. An alternative to chemically treated surfaces for bactericidal activity started emerging from micro/nanoscale topographical cues in the last decade. Here, we demonstrate a putative antibacterial surface using copper nanowhiskers deposited by molecular beam epitaxy. Furthermore, the control of biological response is based on hydrophobic pinning of water droplets in the Wenzel regime, causing mechanical injury and cell death. Scanning electron microscopy images revealed the details of the surface morphology and non-contact mode laser scanning of the surface revealed the microtopography-associated quantitative parameters. Introducing the bacterial culture over nanowhiskers produces mechanical injury to cells, leading to a reduction in cell density over time due to local pinning of culture medium to whisker surfaces. Extended culture to 72 hours to observe biofilm formation revealed biofilm inhibition with scattered microcolonies and significantly reduced biovolume on nanowhiskers. Therefore, surfaces patterned with copper nanowhiskers can serve as potential antibiofilm surfaces. The topography-based antibacterial surfaces introduce a novel prospect in developing mechanoresponsive nanobiomaterials to reduce the risk of medical device biofilm-associated infections, contrary to chemical leaching of copper as a traditional bactericidal agent.

  12. Flux-Vortex Pinning and Neutron Star Evolution (United States)

    Alpar, M. Ali


    G. Srinivasan et al. (1990) proposed a simple and elegant explanation for the reduction of the neutron star magnetic dipole moment during binary evolution leading to low mass X-ray binaries and eventually to millisecond pulsars: Quantized vortex lines in the neutron star core superfluid will pin against the quantized flux lines of the proton superconductor. As the neutron star spins down in the wind accretion phase of binary evolution, outward motion of vortex lines will reduce the dipole magnetic moment in proportion to the rotation rate. The presence of a toroidal array of flux lines makes this mechanism inevitable and independent of the angle between the rotation and magnetic axes. The incompressibility of the flux-line array (Abrikosov lattice) determines the epoch when the mechanism will be effective throughout the neutron star. Flux vortex pinning will not be effective during the initial young radio pulsar phase. It will, however, be effective and reduce the dipole moment in proportion with the rotation rate during the epoch of spindown by wind accretion as proposed by Srinivasan et al. The mechanism operates also in the presence of vortex creep.

  13. Temperature dependent simulation of diamond depleted Schottky PIN diodes (United States)

    Hathwar, Raghuraj; Dutta, Maitreya; Koeck, Franz A. M.; Nemanich, Robert J.; Chowdhury, Srabanti; Goodnick, Stephen M.


    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  14. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hathwar, Raghuraj; Dutta, Maitreya; Chowdhury, Srabanti; Goodnick, Stephen M. [Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287-8806 (United States); Koeck, Franz A. M.; Nemanich, Robert J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-8806 (United States)


    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco{sup ®} Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures.

  15. Pink Ribbon Pin-Ups: photographing femininity after breast cancer. (United States)

    Regehr, Kaitlyn


    Many treatments for breast cancer are traumatic, invasive and harshly visible. In addition to physical trauma, breast cancer is often associated with a variety of psychosocial issues surrounding romantic relationships, sexuality and feminine identity. Pink Ribbon Pin-Ups was a pin-up girl calendar wherein all the models were women who were living with, or had survived, breast cancer. The project's purpose was to raise funds and awareness for breast cancer research and to create a space where survivors could explore and express their post-cancer sexuality. This study uses an observational approach, paired with semi-structured interviews, to explore the ways that breast cancer survivors perceive their post-cancer body and the subsequent impact on relationships and feminine identity. By examining contemporary discussions regarding breast cancer, body image and the objectification of women, it is concluded that although this photographic approach may be at odds with some modern breast cancer activism, it does appear to meet the expressed needs of a particular group of women living with the disease.

  16. Pinning of a drop by a junction on an incline (United States)

    De Coninck, Joël; Fernández Toledano, Juan Carlos; Dunlop, François; Huillet, Thierry


    The shape of a drop pinned on an inclined substrate is a long-standing problem where the complexity of real surfaces, with heterogeneities and hysteresis, makes it complicated to understand the mechanisms behind the phenomena. Here we consider the simple case of a drop pinned on an incline at the junction between a hydrophilic half plane (the top half) and a hydrophobic one (the bottom half). Relying on the equilibrium equations deriving from the balance of forces, we exhibit three scenarios depending on the way the contact line of the drop on the substrate either simply leans against the junction or overfills (partly or fully) into the hydrophobic side. We draw some conclusions on the geometry of the overlap and the stability of these tentative equilibrium states. In the corresponding retention force factor, we find that a major role is played by the wetted length of the junction line, in the spirit of Furmidge's observations. The predictions of the theory are compared with extensive molecular dynamics simulations.

  17. Measurement strategy and analytic model to determine firing pin force (United States)

    Lesenciuc, Ioan; Suciu, Cornel


    As illustrated in literature, ballistics is a branch of theoretical mechanics, which studies the construction and working principles of firearms and ammunition, their effects, as well as the motions of projectiles and bullets1. Criminalistics identification, as part of judiciary identification represents an activity aimed at finding common traits of different objects, objectives, phenomena and beings, but more importantly, traits that differentiate each of them from similar ones2-4. In judicial ballistics, in the case of rifled firearms it is relatively simple for experts to identify the used weapon from traces left on the projectile, as the rifling of the barrel leaves imprints on the bullet, which remain approximately identical even after the respective weapon is fired 100 times with the same barrel. However, in the case of smoothbore firearms, their identification becomes much more complicated. As the firing cap suffers alterations from being hit by the firing pin, determination of the force generated during impact creates the premises for determining the type of firearm used to shoot the respective cartridge. The present paper proposes a simple impact model that can be used to evaluate the force generated by the firing pin during its impact with the firing cap. The present research clearly showed that each rifle, by the combination of the three investigated parameters (impact force maximum value, its variation diagram, and impact time) leave a unique trace. Application of such a method in ballistics can create the perspectives for formulating clear conclusions that eliminate possible judicial errors in this field.

  18. Vortex Pinning in Superconducting MoGe Films Containing Conformal Arrays of Nanoscale Holes and Magnetic Dots (United States)

    Wang, Y. L.; Latimer, M. L.; Xiao, Z. L.; Ocola, L. E.; Divan, R.; Welp, U.; Crabtree, G. W.; Kwok, W. K.


    Recent numerical simulations by Ray et al. predict that a conformal pinning array can produce stronger vortex pinning effect than other pinning structures with an equivalent density of pinning sites. Here we present experimental investigations on conformal pinning structures. Direct and conformal pinning arrays of triangular and square lattices were introduced into MoGe superconducting films using focused-ion-beam milling or electron-beam lithography. Transport measurements on critical currents and magnetoresistances were carried out on these samples to reveal the advantages of conformal pinnings. Effects of random pinnings with the same average density were also studied for comparison. Details on sample fabrications and effects of pinning types (holes versus magnetic dots) will be presented. Work supported by the US DoE-BES funded Energy Frontier Research Center (YLW), and by Department of Energy, Office of Science, Office of Basic Energy Sciences (MLL, ZLX, LEO, RD, UW, WKK), under Contract No. DE-AC02-06CH11357

  19. Crystal growth and property characterization for PIN–PMN–PT ternary piezoelectric crystals

    Directory of Open Access Journals (Sweden)

    Jian Tian


    Full Text Available Binary piezoelectric crystal Pb(Mg1/3Nb2/3O3–PbTiO3 (PMN–PT has excellent dielectric and piezoelectric properties, which has led to the commercialization for medical ultrasound imaging. Recently, there is a growing demand for piezoelectric crystals with improved thermal and electrical properties. Ternary piezoelectric crystals Pb(In1/2Nb1/2O3–Pb(Mg1/3Nb2/3O3–PbTiO3 (PIN–PMN–PT have increased depoling temperature and coercive field than binary PMN–PT. To better understand the ternary crystal system and improve crystal properties, we systematically investigated crystal growth of PIN–PMN–PT with modified Bridgman method. Like PMN–PT, PIN–PMN–PT crystals have excellent piezoelectric properties (e.g., k33 ~ 0.87–0.92, d33 ~ 1000–2200 pm/V. Higher PIN content leads to ~40°C increase in depoling temperature and more than doubling of coercive field(~7.0 kV/cm. Such improvements are advantageous for applications where high temperature and/or high-drive are needed.

  20. Effect of S doping on the critical current density and vortex dynamics in FeSe single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yue, E-mail:; Pyon, Sunseng; Tamegai, Tsuyoshi


    Highlights: • J{sub c} and vortex pinning in S-doped FeSe single crystals are reported for the first time. • The value of J{sub c} for FeSe is found to be enhanced from 4 × 10{sup 4} A/cm{sup 2} at 2 K under self-field to 6 × 10{sup 4} A/cm{sup 2} after S doping. • Strong point-like pinning from nanometer-sized defects or imperfections are dominant in both pure and S-doped FeSe, while S doping reduces the size of flux bundle and enhances the effective pinning energy. - Abstract: We report a detailed study of the S doping effect on the critical current density, J{sub c}, and vortex pinning in FeSe single crystal. The value of J{sub c} for FeSe is found to be enhanced from ∼4 × 10{sup 4} A/cm{sup 2} at 2 K under self-field to ∼6 × 10{sup 4} A/cm{sup 2} after S doping. Similar field decaying rates of J{sub c} and the absence of fishtail effect in both FeSe and FeSe{sub 0.86}S{sub 0.14} single crystals indicate the similar pinning mechanism for both crystals, i.e., the dominance of strong point-like pinning from nanometer-sized defects or imperfections. On the other hand, vortex dynamics study manifests that the S doping reduces the size of flux bundle and enhances the effective pinning energy, which may come from the lattice distortion caused by S doping.

  1. A Genome-Scale Analysis of the PIN Gene Family Reveals Its Functions in Cotton Fiber Development. (United States)

    Zhang, Yuzhou; He, Peng; Yang, Zuoren; Huang, Gai; Wang, Limin; Pang, Chaoyou; Xiao, Hui; Zhao, Peng; Yu, Jianing; Xiao, Guanghui


    The PIN-FORMED (PIN) protein, the most important polar auxin transporter, plays a critical role in the distribution of auxin and controls multiple biological processes. However, characterizations and functions of this gene family have not been identified in cotton. Here, we identified the PIN family in Gossypium hirsutum, Gossypium arboreum, and Gossypium raimondii. This gene family was divided into seven subgroups. A chromosomal distribution analysis showed that GhPIN genes were evenly distributed in eight chromosomes and that the whole genome and dispersed duplications were the main duplication events for GhPIN expansion. qRT-PCR analysis showed a tissue-specific expression pattern for GhPIN. Likely due to the cis-element variations in their promoters, transcripts of PIN6 and PIN8 genes from the At (tetraploid genome orginated from G. arboreum) subgenome and PIN1a from the Dt (tetraploid genome orginated from G. raimondii) subgenome in G. hirsutum was significantly increased compared to the transcripts in the diploids. The differential regulation of these PIN genes after the polyploidization may be conducive to fiber initiation and elongation. Exogenously applied auxin polar transport inhibitor significantly suppressed fiber growth, which is consistent with the essential function of these PIN genes for regulating cotton fiber development. Furthermore, the overexpression of GhPIN1a_Dt, GhPIN6_At, and GhPIN8_At in Arabidopsis promoted the density and length of trichomes in leaves.

  2. Effective magnetic pinning schemes for enhanced superconducting property in high temperature superconductor YBa2Cu3O7‑x : a review (United States)

    Huang, Jijie; Wang, Haiyan


    Enhanced superconducting properties under magnetic field in high temperature superconductors are critical for their technological applications and can be enhanced by both defect pinning and magnetic pinning. Different from defect pinning introduced by nonmagnetic pinning centers, magnetic pinning has some advantages over defect pinning, as it pins the magnetic flux rather than the normal core vortices. Various magnetic materials and different designed architectures have been demonstrated to provide magnetic pinning effect. Four major pinning schemes including metal/YBCO, oxide/YBCO, nanocomposite/YBCO and nanoparticle embedded YBCO have been reviewed. Representative literatures for each magnetic pinning scheme are discussed in detail to explore the pinning enhancement for each scheme. In addition, combined magnetic pinning and defect pinning schemes are proposed to further improve superconducting properties.

  3. Weak transitions in lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Maturana, G.


    Some techniques to calculate the effects of the strong interactions on the matrix elements of weak processes are described. The lattice formulation of Quantum Chromodynamics is used to account for the low energy gluons, and the corresponding numerical methods are explained. The high energy contributions are included in effective lagrangians and the problem of matching the different scales related to the renormalization of the operators and wavefunctions is also discussed. The = 1/2 enhancement rule and the K/sup 0/-anti-K/sup 0/ are used to illustrate these techniques and the results of a numerical calculation is reported. The values obtained are very encouraging and they certainly show good qualitative agreement with the experimental values. The emphasis is on general techniques, and in particular, several improvements to this particular calculation are proposed.

  4. Strengths, weaknesses, opportunities and threats

    DEFF Research Database (Denmark)

    Bull, Joseph William; Jobstvogt, N.; Böhnke-Henrichs, A.


    The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake. Such an assess......The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake....... Such an assessment could form the basis for improving ES thinking, further embedding it into environmental decisions and management.The Young Ecosystem Services Specialists (YESS) completed a Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis of ES through YESS member surveys. Strengths include the approach...

  5. Enhanced flux pinning and critical currents in YBa2Cu3O7-δ films by nanoparticle surface decoration: Extension to coated conductor templates (United States)

    Aytug, T.; Paranthaman, M.; Leonard, K. J.; Kim, K.; Ijaduola, A. O.; Zhang, Y.; Tuncer, E.; Thompson, J. R.; Christen, D. K.


    Interfacial engineering via nanoparticle substrate surface decoration has been extended to coated conductor templates. Preformed BaTiO3 and BaZrO3 nanoparticles were applied to substrate surfaces, prior to YBa2Cu3O7-δ (YBCO) deposition, by using a scalable and inexpensive technique of solution-based suspension. Compared to untreated reference samples, nanodecoration yields improved in-field critical current density (Jc) as well as strong correlated pinning along the c-axis direction of the YBCO film. Accordingly, a much reduced falloff of Jc with magnetic field strength was observed in all of the modified samples. In addition, scaling behavior of the normalized volume pinning force density (Fp) with respect to temperature provided insight as to the differences in flux pinning mechanisms dependent on the decoration technique. Finally, with these results our earlier proof-of-concept demonstrations on nanoparticle modified single crystal substrates were replicated on technological substrates, pointing to the versatility of this simple technique for realization of enhanced high temperature superconductor performance.

  6. High Performance Relaxor-Based Ferroelectric Single Crystals for Ultrasonic Transducer Applications

    Directory of Open Access Journals (Sweden)

    Yan Chen


    Full Text Available Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3O3-PbTiO3 (PMN-PT have drawn much attention in the ferroelectric field because of their excellent piezoelectric properties and high electromechanical coupling coefficients (d33~2000 pC/N, kt~60% near the morphotropic phase boundary (MPB. Ternary Pb(In1/2Nb1/2O3-Pb(Mg1/3Nb2/3O3-PbTiO3 (PIN-PMN-PT single crystals also possess outstanding performance comparable with PMN-PT single crystals, but have higher phase transition temperatures (rhombohedral to tetragonal Trt, and tetragonal to cubic Tc and larger coercive field Ec. Therefore, these relaxor-based single crystals have been extensively employed for ultrasonic transducer applications. In this paper, an overview of our work and perspectives on using PMN-PT and PIN-PMN-PT single crystals for ultrasonic transducer applications is presented. Various types of single-element ultrasonic transducers, including endoscopic transducers, intravascular transducers, high-frequency and high-temperature transducers fabricated using the PMN-PT and PIN-PMN-PT crystals and their 2-2 and 1-3 composites are reported. Besides, the fabrication and characterization of the array transducers, such as phased array, cylindrical shaped linear array, high-temperature linear array, radial endoscopic array, and annular array, are also addressed.

  7. Sensitive pre-amplifier to load for Pin diodes; Pre-amplificador sensible a carga para diodos PIN

    Energy Technology Data Exchange (ETDEWEB)

    Jacobo V, R. Y.; Hernandez D, V. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Ramirez J, F. J., E-mail: [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)


    The electronic instrumentation is indispensable for the measurement and characterization of the radiation. By means of this essential characteristics of the radiation are determined, as activity and their energy components. The nuclear instrumentation is based on the technical characteristics of the radiation detectors and the electronic devices associates (amplifiers, ana logical and digital converters, multichannel analyzers, etc.) The radiation detectors are very important instruments in fields as the nuclear physics, medicine, radiological protection, industry and in other fields, since they are the only method to capture the radiation and to be able to quantify it in precise form. To detect radiation diverse detector types are used, as the semiconductor type, inside them are the photodiodes type Pin. In this work the results that were obtained of the design, simulation, construction and tests of a preamplifier that was designed starting from a photodiode type Pin are presented. The system was designed and simulated with a program for electronic circuits, in this were carried out many tests being obtained a compact design and achieving the best necessary characteristics for its optimization. With the results of the simulation phase the electronics phase was built, which was couples to a spectroscopic amplifier and a multichannel analyzer. The total of the system was evaluated analyzing its performance before a triple source of alphas. Of the tests phase we find that the system allows obtaining, in a multichannel analyzer, the pulses height spectrum, with a good resolution and with this was calibrated the multichannel analyzer.

  8. Whole core pin-by-pin coupled neutronic-thermal-hydraulic steady state and transient calculations using COBAYA3 code

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, J.; Herrero, J. J.; Cuervo, D.; Aragones, J. M., E-mail: jimenez@din.upm.e [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, Jose Gutierrez Abascal No. 2, 28006 Madrid (Spain)


    Nowadays coupled 3-dimensional neutron kinetics and thermal-hydraulic core calculations are performed by applying a radial average channel approach using a meshing of one quarter of assembly in the best case. This approach does not take into account the subchannels effects due to the averaging of the physical fields and the loose of heterogeneity in the thermal-hydraulic model. Therefore the models do not have enough resolution to predict those subchannels effects which are important for the fuel design safety margins, because it is in the local scale, where we can search the hottest pellet or the maximum heat flux. The Polytechnic University of Madrid advanced multi-scale neutron-kinetics and thermal-hydraulics methodologies being implemented in COBAYA3 include domain decomposition by alternate core dissections for the local 3-dimensional fine-mesh scale problems (pin cells/subchannels) and an analytical nodal diffusion solver for the coarse mesh scale coupled with the thermal-hydraulic using a model of one channel per assembly or per quarter of assembly. In this work, we address the domain decomposition by the alternate core dissections methodology applied to solve coupled 3-dimensional neutronic-thermal-hydraulic problems at the fine-mesh scale. The neutronic-thermal-hydraulic coupling at the cell-subchannel scale allows the treatment of the effects of the detailed thermal-hydraulic feedbacks on cross-sections, thus resulting in better estimates of the local safety margins at the pin level. (Author)

  9. Fault zone fabric and fault weakness

    NARCIS (Netherlands)

    Collettini, C.; Niemeijer, A.; Viti, C.; Marone, C.


    Geological and geophysical evidence suggests that some crustal faults are weak1–6 compared to laboratory measurements of frictional strength7. Explanations for fault weakness include the presence of weak minerals4, high fluid pressures within the fault core8,9 and dynamic processes such as

  10. Weakly distributive modules. Applications to supplement submodules

    Indian Academy of Sciences (India)

    Abstract. In this paper, we define and study weakly distributive modules as a proper generalization of distributive modules. We prove that, weakly distributive supplemented modules are amply supplemented. In a weakly distributive supplemented module every submodule has a unique coclosure. This generalizes a result of ...

  11. Liquid Crystals (United States)


    Thermochromic liquid crystals, or TLCs, are a type of liquid crystals that react to changes in temperature by changing color. The Hallcrest/NASA collaboration involved development of a new way to visualize boundary layer transition in flight and in wind tunnel testing of aircraft wing and body surfaces. TLCs offered a new and potentially better method of visualizing the boundary layer transition in flight. Hallcrest provided a liquid crystal formulation technique that afforded great control over the sensitivity of the liquid crystals to varying conditions. Method is of great use to industry, government and universities for aerodynamic and hydrodynamic testing. Company's principal line is temperature indicating devices for industrial use, such as non-destructive testing and flaw detection in electric/electronic systems, medical application, such as diagnostic systems, for retail sale, such as room, refrigerator, baby bath and aquarium thermometers, and for advertising and promotion specials. Additionally, Hallcrest manufactures TLC mixtures for cosmetic applications, and liquid crystal battery tester for Duracell batteries.

  12. PPP1, a plant-specific regulator of transcription controls Arabidopsis development and PIN expression

    NARCIS (Netherlands)

    Benjamins, René; Barbez, Elke; Ortbauer, Martina; Terpstra, Inez; Lucyshyn, Doris; Moulinier-Anzola, Jeanette; Khan, Muhammad Asaf; Leitner, Johannes; Malenica, Nenad; Butt, Haroon; Korbei, Barbara; Scheres, Ben; Kleine-Vehn, Jürgen; Luschnig, Christian


    Directional transport of auxin is essential for plant development, with PIN auxin transport proteins representing an integral part of the machinery that controls hormone distribution. However, unlike the rapidly emerging framework of molecular determinants regulating PIN protein abundance and

  13. Effects of Linking-Pin Quality on the Quality of Working Life of Lower Participants (United States)

    Graen, George; And Others


    Managerial dyads employed in service organizations were assessed regarding the quality of their upward linking pins--the perceived effectiveness of the leader-member exchange between the incumbents of the linking-pin positions with their immediate superior--and the behavior, attitudes, and treatment of the lower participants. (Author/IRT)

  14. Assessment of Radiographic Image Quality by Visual Examination of Neutron Radiographs of the Calibration Fuel Pin

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw


    of a calibration fuel pin. The radiographs were made by the direct, transfer and tracketch methods using different film recording materials. These neutron radiographs of the calibration fuel pin were used for the assessement of radiographic image quality. This was done by visual examination of the radiographs...... and assessing their radiographic image quality on an arbitrary scale....

  15. Incidence and risk factors for pin tract infection in external fixation of ...

    African Journals Online (AJOL)

    Background: Pin tract infection is a complication when using external fixation. The objective of this study was to estimate the incidence, rate and risk factors for pin tract infections after external fixation in the orthopedics wards in a major teaching hospital in Togo (West Africa). Methods: A one year prospective cohort study ...

  16. A covalent PIN1 inhibitor selectively targets cancer cells by a dual mechanism of action (United States)

    Campaner, Elena; Rustighi, Alessandra; Zannini, Alessandro; Cristiani, Alberto; Piazza, Silvano; Ciani, Yari; Kalid, Ori; Golan, Gali; Baloglu, Erkan; Shacham, Sharon; Valsasina, Barbara; Cucchi, Ulisse; Pippione, Agnese Chiara; Lolli, Marco Lucio; Giabbai, Barbara; Storici, Paola; Carloni, Paolo; Rossetti, Giulia; Benvenuti, Federica; Bello, Ezia; D'Incalci, Maurizio; Cappuzzello, Elisa; Rosato, Antonio; Del Sal, Giannino


    The prolyl isomerase PIN1, a critical modifier of multiple signalling pathways, is overexpressed in the majority of cancers and its activity strongly contributes to tumour initiation and progression. Inactivation of PIN1 function conversely curbs tumour growth and cancer stem cell expansion, restores chemosensitivity and blocks metastatic spread, thus providing the rationale for a therapeutic strategy based on PIN1 inhibition. Notwithstanding, potent PIN1 inhibitors are still missing from the arsenal of anti-cancer drugs. By a mechanism-based screening, we have identified a novel covalent PIN1 inhibitor, KPT-6566, able to selectively inhibit PIN1 and target it for degradation. We demonstrate that KPT-6566 covalently binds to the catalytic site of PIN1. This interaction results in the release of a quinone-mimicking drug that generates reactive oxygen species and DNA damage, inducing cell death specifically in cancer cells. Accordingly, KPT-6566 treatment impairs PIN1-dependent cancer phenotypes in vitro and growth of lung metastasis in vivo.


    Sternick, Marcelo Back; Dallacosta, Darlan; Bento, Daniela Águida; do Reis, Marcelo Lemos


    To analyze the rigidity of a platform-type external fixator assembly, according to different numbers of pins on each clamp. Computer simulation on a large-sized Cromus dynamic external fixator (Baumer SA) was performed using a finite element method, in accordance with the standard ASTM F1541. The models were generated with approximately 450,000 quadratic tetrahedral elements. Assemblies with two, three and four Schanz pins of 5.5 mm in diameter in each clamp were compared. Every model was subjected to a maximum force of 200 N, divided into 10 sub-steps. For the components, the behavior of the material was assumed to be linear, elastic, isotropic and homogeneous. For each model, the rigidity of the assembly and the Von Mises stress distribution were evaluated. The rigidity of the system was 307.6 N/mm for two pins, 369.0 N/mm for three and 437.9 N/mm for four. The results showed that four Schanz pins in each clamp promoted rigidity that was 19% greater than in the configuration with three pins and 42% greater than with two pins. Higher tension occurred in configurations with fewer pins. In the models analyzed, the maximum tension occurred on the surface of the pin, close to the fixation area.

  18. Effect of pinning and driving force on the metastability effects in ...

    Indian Academy of Sciences (India)

    susceptibility measurements appears to generate a driving force on the vortex matter. In a nascent pinned single ... pinning in order to differentiate the response of different metastable vortex states, one encounters a new phenomenon, viz., ...... using a lock-in amplifier having a wide band filter option. The above-stated noise.

  19. Effect of Pin Geometry on the Mechanical Strength of Friction-Stir-Welded Polypropylene Composite Plates (United States)

    Kordestani, F.; Ashenai Ghasemi, F.; Arab, N. B. M.


    Friction stir welding (FSW) is a solid-state welding process, which has successfully been applied in aerospace and automotive industries for joining materials. The friction stir tool is the key element in the FSW process. In this study, the effect of four different tool pin geometries on the mechanical properties of two types of polypropylene composite plates, with 30% glass and carbon fiber, respectively, were investigated. For this purpose, four pins of different geometry, namely, a threaded-tapered pin, square pin, four-flute threaded pin, and threaded-tapered pin with a chamfer were made and used to carry out the butt welding of 5-mm-thick plates. The standard tensile and Izod impact tests were performed to evaluate the tensile strength and impact toughness of welded specimens. The results indicated that the threaded-tapered pin with a chamfer produced welds with a better surface appearance and higher tensile and impact strengths. The tests also showed that, with the threaded-tapered pin with a chamfer, the impact strength of the glass- and carbon-fiber composite welds were about 40 and 50%, respectively, of that of the base materials.

  20. Evaluating Approaches to Rendering Braille Text on a High-Density Pin Display. (United States)

    Morash, Valerie S; Russomanno, Alexander; Gillespie, R Brent; OModhrain, Sile


    Refreshable displays for tactile graphics are typically composed of pins that have smaller diameters and spacing than standard braille dots. We investigated configurations of high-density pins to form braille text on such displays using non-refreshable stimuli produced with a 3D printer. Normal dot braille (diameter 1.5 mm) was compared to high-density dot braille (diameter 0.75 mm) wherein each normal dot was rendered by high-density simulated pins alone or in a cluster of pins configured in a diamond, X, or square; and to "blobs" that could result from covering normal braille and high-density multi-pin configurations with a thin membrane. Twelve blind participants read MNREAD sentences displayed in these conditions. For high-density simulated pins, single pins were as quickly and easily read as normal braille, but diamond, X, and square multi-pin configurations were slower and/or harder to read than normal braille. We therefore conclude that as long as center-to-center dot spacing and dot placement is maintained, the dot diameter may be open to variability for rendering braille on a high density tactile display.

  1. Auditing the use of percutaneous pinning as a technique of fixation ...

    African Journals Online (AJOL)

    Background:Supracondylar fractures of the humerus in children are commonly treated with closed reduction and percutaneous pin fixation. There has been controversy regarding the optimal pin configuration in the management of supracondylar humeral fractures in children. Objectives: To evaluate the effectiveness of ...

  2. Temperature dependence of critical currents in REBCO thin films with artificial pinning centers (United States)

    Matsumoto, Kaname; Nishihara, Masaya; Kimoto, Takamasa; Horide, Tomoya; Jha, Alok Kumar; Yoshida, Yutaka; Awaji, Satoshi; Ichinose, Ataru


    Conventionally, δT c type (order parameter modulation) and δl type (mean free path modulation) pinning mechanisms have been proposed to explain the temperature dependence of the flux pinning of superconducting materials. According to previous studies, it is assumed that the temperature dependence of J c of REBa2Cu3O7 (REBCO, RE = Y, Gd, Sm, etc) films without artificial pinning centers (APCs) is δl type, but it is unidentified when APCs are introduced into the films. In this paper, GdBCO thin films doped with BaHfO3 (BHO) deposited on LaAlO3 substrates by pulsed laser deposition were studied. A target exchange method was used to alternately ablate two targets of pure GdBCO and BHO for introducing nanorods as APCs into GdBCO films. Since the insulative BHO acts as a strong pinning center, the δT c pinning mechanism is expected for the temperature dependence of J c of these thin films. However, the experimental results showed that the J c of the films with BHO nanorods was determined by the δl pinning mechanism over a wide temperature range. In order to explain these unexpected results, we examined the pinning mechanism by nanorods based on a resultant pinning force model.

  3. The effects of cast support on pin loosening and infection in tibial skeletal traction

    Directory of Open Access Journals (Sweden)

    Moghtadaei M


    Full Text Available "nBackground: Pin loosening and infection in skeletal traction are important problems in orthopedic surgery and methods which are usually used to manage these problems, are costly and sometimes complicated. In this study, the efficacy of using cast support in infection and loosening of proximal tibial pin was investigated. "nMethods: In a randomized clinical trial, 60 patients referring to Rasul-e- Akram hospital from 1383 to 1384, who needed to have proximal tibial pin for at least one month, were studied. All patients were treated with oral antibiotic until 24 hours after pin insertion. Depending on using cast support or not, they were randomly categorized into two groups (30, 30. The rate of pin loosening and infection between these two groups were compared. "nResults: In the group without cast support infection rate was about %26.7 while this rate was %13.3 in the group with cast support, which means no significant difference (.33. In addition, although the rate of loosening in the group without cast support was more than the other group, it had no statistical meaning. (%20 compared with %10, p= 0.47 "nConclusions: Cast support doesn't affect the rate of pin loosening and pin site infection. However, considering correct technique for pin insertion including prevention of thermal injury and local hematoma is very important. Therefore, the use of cast support is an optional choice up to surgeons' preference.

  4. Theoretical models of flux pinning and flux motion in high-{Tc} superconducting oxides

    Energy Technology Data Exchange (ETDEWEB)

    Welch, D.O.


    Various issues involved in the development of phenomenological models of flux pinning and motion in high-{Tc} oxides are discussed. A simplified model is presented for the critical current density and is used to examine the question of whether flux flow results from an instability due to plasticity of the flux-line array or from pin breaking.

  5. Using the Missing Pin to Challenge Concepts of Refraction and Total Internal Reflection (United States)

    Tamang, Sushmika; Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Nopparatjamjomras, Thasaneeya R.


    A container was placed on top of a piece of white paper, and a pin positioned so that it vertically touched an outside wall of the container. Students were asked to predict the image of the pin when it was observed from the top of the container. Two scenarios of either an empty container or a container completely filled with water were considered…

  6. Detecting pin diversion from pressurized water reactors spent fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Young S.; Sitaraman, Shivakumar


    Detecting diversion of spent fuel from Pressurized Water Reactors (PWR) by determining possible diversion including the steps of providing a detector cluster containing gamma ray and neutron detectors, inserting the detector cluster containing the gamma ray and neutron detectors into the spent fuel assembly through the guide tube holes in the spent fuel assembly, measuring gamma ray and neutron radiation responses of the gamma ray and neutron detectors in the guide tube holes, processing the gamma ray and neutron radiation responses at the guide tube locations by normalizing them to the maximum value among each set of responses and taking the ratio of the gamma ray and neutron responses at the guide tube locations and normalizing the ratios to the maximum value among them and producing three signatures, gamma, neutron, and gamma-neutron ratio, based on these normalized values, and producing an output that consists of these signatures that can indicate possible diversion of the pins from the spent fuel assembly.

  7. Using Pin as a Memory Reference Generator for Multiprocessor Simulation

    Energy Technology Data Exchange (ETDEWEB)

    McCurdy, C


    In this paper we describe how we have used Pin to generate a multithreaded reference stream for simulation of a multiprocessor on a uniprocessor. We have taken special care to model as accurately as possible the effects of cache coherence protocol state, and lock and barrier synchronization on the performance of multithreaded applications running on multiprocessor hardware. We first describe a simplified version of the algorithm, which uses semaphores to synchronize instrumented application threads and the simulator on every memory reference. We then describe modifications to that algorithm to model the microarchitectural features of the Itanium2 that affect the timing of memory reference issue. An experimental evaluation determines that while cycle-accurate multithreaded simulation is possible using our approach, the use of semaphores has a negative impact on the performance of the simulator.

  8. Model of Ni-63 battery with realistic PIN structure

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Charles E.; Voss, Paul L.; Ougazzaden, Abdallah, E-mail: [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, 30332-0250 Atlanta (United States); Arif, Muhammad; Salvestrini, Jean-Paul [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Université de Lorraine, CentraleSupélec, LMOPS, EA 4423, 2 rue E. Belin, 57070 Metz (France); Streque, Jeremy; El Gmili, Youssef [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim [Laboratory for Photonics and Nanostructures, CNRS, Route de Nozay, 91460 Marcoussis (France)


    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination.

  9. Model of Ni-63 battery with realistic PIN structure (United States)

    Munson, Charles E.; Arif, Muhammad; Streque, Jeremy; Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim; El Gmili, Youssef; Salvestrini, Jean-Paul; Voss, Paul L.; Ougazzaden, Abdallah


    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination.

  10. Statistical mechanics of homogeneous partly pinned fluid systems. (United States)

    Krakoviack, Vincent


    The homogeneous partly pinned fluid systems are simple models of a fluid confined in a disordered porous matrix obtained by arresting randomly chosen particles in a one-component bulk fluid or one of the two components of a binary mixture. In this paper, their configurational properties are investigated. It is shown that a peculiar complementarity exists between the mobile and immobile phases, which originates from the fact that the solid is prepared in presence of and in equilibrium with the adsorbed fluid. Simple identities follow, which connect different types of configurational averages, either relative to the fluid-matrix system or to the bulk fluid from which it is prepared. Crucial simplifications result for the computation of important structural quantities, both in computer simulations and in theoretical approaches. Finally, possible applications of the model in the field of dynamics in confinement or in strongly asymmetric mixtures are suggested.

  11. Weak matrix elements of kaons

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, C. (California Univ., Santa Barbara, CA (USA). Inst. for Theoretical Physics); Soni, A. (Brookhaven National Lab., Upton, NY (USA))


    We present results from the Wilson fermion part of the Grand Challenge'' weak matrix element project. A new procedure for correcting the chiral behavior of {Beta}{sub LL}{sup sd}, the K{sup 0}-{bar K}{sup 0} {Beta} parameter,'' is proposed and applied. On our largest lattice (24{sup 3} {times} 40 at {beta} = 6.0), we get {Beta}{sub LL}{sup sd} = .86 {plus minus} .11 {plus minus} .05, where the first error is statistical and the second is a measure of the systematic errors due to the procedure and to related finite-size effects. Results for the direct K{sup +} {yields} {pi}{sup +}{pi}{sup 0} amplitude are also presented. There is some evidence for higher order chiral effects which may make these results compatible both with experiment and with the {Beta}{sub LL}{sup sd} computation. The status of the direct K{sub s}{sup 0} {yields} {pi} {sup +} {pi}{sup {minus}} {Delta}I = 1/2 amplitude is then discussed. 11 refs., 6 figs., 1 tab.

  12. A Universe without Weak Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Harnik, Roni; Kribs, Graham D.; Perez, Gilad


    A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.

  13. Protecting weak measurements against systematic errors (United States)

    Pang, Shengshi; Alonso, Jose Raul Gonzalez; Brun, Todd A.; Jordan, Andrew N.


    In this work, we consider the systematic error of quantum metrology by weak measurements under decoherence. We derive the systematic error of maximum likelihood estimation in general to the first-order approximation of a small deviation in the probability distribution and study the robustness of standard weak measurement and postselected weak measurements against systematic errors. We show that, with a large weak value, the systematic error of a postselected weak measurement when the probe undergoes decoherence can be significantly lower than that of a standard weak measurement. This indicates another advantage of weak-value amplification in improving the performance of parameter estimation. We illustrate the results by an exact numerical simulation of decoherence arising from a bosonic mode and compare it to the first-order analytical result we obtain.

  14. Evaluation of percutaneous pinning in unstable proximal humeral fractures: A novel technique

    Directory of Open Access Journals (Sweden)

    Nishikant Kumar


    Full Text Available Management of unstable proximal humeral fractures has remained controversial since ages. Open reduction and internal fixation have resulted in devastating complications like stiffness of shoulder joint, avascular necrosis, infection, etc., We are presenting a novel method of percutaneous pinning of unstable proximal humeral fractures. All cases (32 were done closely without soft tissue stripping. All cases were followed-up for a period of 3 years; and results were assessed according to 100 point constant score. A total of 75% cases showed excellent to good results. To minimize the complications like pin site infection, loosening, neurovascular damage we used fixed pin site insertion technique, and threaded pins in osteoporotic patients. So percutaneous pinning is a safe and novel method of management of unstable proximal humeral fractures if certain principles are borne in mind before using it.

  15. Cell polarity and patterning by PIN trafficking through early endosomal compartments in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Hirokazu Tanaka


    Full Text Available PIN-FORMED (PIN proteins localize asymmetrically at the plasma membrane and mediate intercellular polar transport of the plant hormone auxin that is crucial for a multitude of developmental processes in plants. PIN localization is under extensive control by environmental or developmental cues, but mechanisms regulating PIN localization are not fully understood. Here we show that early endosomal components ARF GEF BEN1 and newly identified Sec1/Munc18 family protein BEN2 are involved in distinct steps of early endosomal trafficking. BEN1 and BEN2 are collectively required for polar PIN localization, for their dynamic repolarization, and consequently for auxin activity gradient formation and auxin-related developmental processes including embryonic patterning, organogenesis, and vasculature venation patterning. These results show that early endosomal trafficking is crucial for cell polarity and auxin-dependent regulation of plant architecture.

  16. Local production of skeletal traction pins to improve access to skeletal traction. (United States)

    Kadhum, Murtaza; Mannion, Stephen


    Femoral fractures represent a substantial orthopaedic injury. In the developed world, closed reduction and locked intramedullary nailing is recognized as the optimal treatment. In the less developed world, the use of skeletal traction remains limited by cost and availability of traction pins, which are obtained from orthopaedic companies in the UK or Indian subcontinent. This study aimed to establish whether traction pins may be manufactured locally in resource-limited countries from cut down stainless steel rods. The overall costs for traction pins were obtained from five UK, Indian subcontinent-based companies and metal fabrication shops in Africa. Strict design specifications were provided. The mean price for 100 Steinmann pins was$428 in the Indian subcontinent,$96 in Malawi,$105 in Kenya and$244 in Tanzania. Our results indicate that Steinmann pins may be manufactured locally in resource-limited countries at a significantly cheaper price, which may increase the access to skeletal traction. © The Author(s) 2015.

  17. Failure analysis on false call probe pins of microprocessor test equipment (United States)

    Tang, L. W.; Ong, N. R.; Mohamad, I. S. B.; Alcain, J. B.; Retnasamy, V.


    A study has been conducted to investigate failure analysis on probe pins of test modules for microprocessor. The `health condition' of the probe pin is determined by the resistance value. A test module of 5V power supplied from Arduino UNO with "Four-wire Ohm measurement" method is implemented in this study to measure the resistance of the probe pins of a microprocessor. The probe pins from a scrapped computer motherboard is used as the test sample in this study. The functionality of the test module was validated with the pre-measurement experiment via VEE Pro software. Lastly, the experimental work have demonstrated that the implemented test module have the capability to identify the probe pin's `health condition' based on the measured resistance value.

  18. Prophylactic pinning for slipped capital femoral epiphysis: does it affect proximal femoral morphology? (United States)

    Cousins, Gerard R; Campbell, Donald M; Wilson, Neil I L; Maclean, Jamie G B


    This study was designed to determine whether prophylactic pinning of the unaffected hip in unilateral slipped capital femoral epiphysis affects the proximal femoral morphology. Twenty-four hips prophylactically pinned were compared with 26 cases observed. The articulotrochanteric distance (ATD) and the trochanteric-trochanteric distance (TTD) were measured. Postoperative radiographs were compared with final follow-up radiographs. The final TTD : ATD ratio was higher (P=0.048) in the pinned group, suggesting relative coxa vara/breva. There was a smaller difference between the two hips in the prophylactically pinned group (0.7) as opposed to those observed (1.47). Prophylactic pinning does not cause growth to stop immediately but alters the proximal femoral morphology.

  19. Patterns of Cognitive Strengths and Weaknesses and Relationships to Math Errors (United States)

    Koriakin, Taylor; White, Erica; Breaux, Kristina C.; DeBiase, Emily; O'Brien, Rebecca; Howell, Meiko; Costa, Michael; Liu, Xiaochen; Pan, Xingyu; Courville, Troy


    This study investigated cognitive patterns of strengths and weaknesses (PSW) and their relationship to patterns of math errors on the Kaufman Test of Educational Achievement (KTEA-3). Participants, ages 5 to 18, were selected from the KTEA-3 standardization sample if they met one of two PSW profiles: high crystallized ability (Gc) paired with low…

  20. Pin Site Complications Associated With Computer-Assisted Navigation in Hip and Knee Arthroplasty. (United States)

    Kamara, Eli; Berliner, Zachary P; Hepinstall, Matthew S; Cooper, H John


    There has been a great increase in the use of navigation technology in joint arthroplasty. In most types of navigation-assisted surgery, several temporary navigation pins are placed in the patient. Goals of this study are (1) to identify complications and (2) risk factors associated with placement of these pins. This is a retrospective cohort study of all navigation-assisted hip and knee arthroplasty performed a single institution over a 3-year period. Records were reviewed and outcome measures were tabulated in a database. Complications included in the database were pin site infection, deep prosthetic joint infection, neurologic injury, vascular injury, and fracture through a pin site. A total of 3136 pin sites in 839 patients were included in the study. Five pin site complications were reported with a complication rate of 0.16% per pin site and 0.60% per patient. The complications-per-procedure were slightly higher for unicondylar knee arthroplasty (0.64%) compared with patellofemoral arthroplasty (0%) and total hip arthroplasty (0.46%), but not statistically significant. There were three infections, one neuropraxia, and one suture abscess. No periprosthetic fractures through a pin site were reported. All complications were resolved with nonoperative treatment. The infections required oral antibiotics, and were associated with transcortical drilling in two cases and juxtacortical drilling in the third. Pins required for navigation-assisted arthroplasty have a low complication rate. Transcortical or juxtacortical drilling may be a risk factor for pin site infection; future studies should be directed at quantifying this effect. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Vortex pinning by a novel stress induced stacking fault microstructure in melt-textured YBa{sub 2}Cu{sub 3}O{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Plain, J [Institut de Ciencia de Materials de Barcelona (CSIC), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Sandiumenge, F [Institut de Ciencia de Materials de Barcelona (CSIC), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Rabier, J [Laboratoire de Metallurgie Physique, UMR 6630, CNRS, Universite de Poitiers, SP2MI, Bd 3, Teleport 2, BP 30179, F-86962 Chasseneuil Futuroscope Cedex (France); Proult, A [Laboratoire de Metallurgie Physique, UMR 6630, CNRS, Universite de Poitiers, SP2MI, Bd 3, Teleport 2, BP 30179, F-86962 Chasseneuil Futuroscope Cedex (France); Stretton, I [Bayerisches Geoinstitut (BGI), Universitaet Bayreuth, D-95440 (Germany); Puig, T [Institut de Ciencia de Materials de Barcelona (CSIC), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Obradors, X [Institut de Ciencia de Materials de Barcelona (CSIC), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia (Spain)


    Transmission electron microscopy observations of melt-textured YBa{sub 2}Cu{sub 3}O{sub 7}-Y{sub 2}BaCuO{sub 5} composites deformed under uniaxial stress and a superposed gaseous confining pressure reveal the activation of a novel YBa{sub 2}Cu{sub 4}O{sub 8}-type stacking fault source. This mechanism operates as a partial Frank Read source leading to small diameter (100-300 nm) 1/6<301> loops. J{sub c}{sup ab}(T) dependences reveal a temperature dependent enhancement which is maximum at low temperatures, i.e., 45% at 5 K. A fit of J{sub c}{sup ab}(T) to a model that considers two contributions to J{sub c}, namely correlated disorder and weak pinning, reveals that only the weak pinning contribution associated with the newly generated in-plane dislocation substructure is enhanced after deformation.

  2. Results of a compression pin alongwith trochanteric external fixation in management of high risk elderly intertrochanteric fractures

    Directory of Open Access Journals (Sweden)

    Aydin Arslan


    Conclusions: Treatment of very elderly, high risk patients' with intertrochanteric fractures with external fixation is effective. Compression pin maintained stability better than standard pins after weight bearing, especially for unstable intertrochanteric fractures.

  3. Crystal structure of pyriproxyfen

    Directory of Open Access Journals (Sweden)

    Gihaeng Kang


    Full Text Available In the title compound {systematic name: 4-phenoxyphenyl (RS-2-[(pyridin-2-yloxy]propyl ether}, C20H19NO3, which is a juvenile hormone mimic and insecticide, the dihedral angles between the plane of the central benene ring and those of the pendant pyridine ring and phenyl ring are 78.09 (6 and 82.14 (8°, respectively. The conformation of the O—C—C—O linkage is gauche [torsion angle = −75.0 (2°]. In the crystal, weak aromatic π–π stacking interactions [centroid–centroid separation = 3.8436 (13 Å] and C—H...π interactions link adjacent molecules, forming a three-dimensional network.

  4. Inchworm Driving of 4He Crystals in Superfluid (United States)

    Yoshida, Taichi; Tachiki, Akira; Nomura, Ryuji; Okuda, Yuichi


    A 4He quantum crystal can be grown from a superfluid liquid extremely quickly owing to the high crystallization rate at sufficiently low temperatures. Such crystals are readily deformed by an applied force as the result of the crystal-superfluid phase transition but, to date, the remotely controlled movement of highly deformable 4He crystals has yet to be demonstrated. The present work attempted to move 4He crystals using inchworm driving, a technique that is employed to impart motion to classical solid objects based on the difference between static and dynamic friction forces. Using a plate oscillating with a sawtooth-like non-symmetric motion 100 times over the span of 1.0 s, it was found possible to move a 4He crystal on the plate in a superfluid at 0.3 K. However, the observed behavior was quite different from the ordinary inchworm driving of a classical object. Initially, one side of the crystal was seen to stick on the plate, and the crystal did not move for 0.6 s but rather deformed appreciably. After this deformation, the entire body of the crystal began to move, but the distance traversed was one order of magnitude larger than expected from the oscillation amplitude. This peculiar behavior is specific to this quantum crystal. The initial lack of motion can possibly be explained by pinning and depinning of the contact line on the substrate plate, while the extent of motion is attributed to the crystal-superfluid transition, namely crystallization on one side and melting on the other, assisted by superflow induced during the oscillation process.

  5. Identification of Possible Molecular Markers to Predict the Malignant Tendency of the Prostate Intraepithelial Neoplasia (PIN) Lesions (United States)


    Intraepithelial Neoplasia (PIN) Lesions PRINCIPAL INVESTIGATOR: Youqiang Ke, Ph.D...NUMBER of the Prostate Intraepithelial Neoplasia (PIN) Lesions 5b. GRANT NUMBER W81XWH-05-1-0069 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...the malignant tendency of the Prostate Intraepthelial Neoplasia (PIN) lesion. During the past year, our main effort has been made to establish

  6. Evaluation of FFTF fuel pin design procedure vis-a-vis steady state irradiation performance in EBR II

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, R.J.


    The FFTF fuel pin design analysis is shown to be conservative through comparison with pin irradiation experience in EBR-II. This comparison shows that the actual lifetimes of EBR-II fuel pins are either greater than 80,000 MWd/MTM or greater than the calculated allowable lifetimes based on thermal creep strain.

  7. A ROP GTPase-dependent auxin signaling pahtway regulates the subcellular distribution of PIN2 in Arabidopsis roots

    NARCIS (Netherlands)

    Lin, D.; Nagawa, S.; Chen, J.; Cao, L.; Scheres, B.


    PIN-FORMED (PIN) protein-mediated auxin polar transport is critically important for development, pattern formation, and morphogenesis in plants. Auxin has been implicated in the regulation of polar auxin transport by inhibiting PIN endocytosis [1 and 2], but how auxin regulates this process is

  8. High performance characteristics in pin MW HgCdTe e-APDs (United States)

    Rothman, J.; Perrais, G.; Destefanis, G.; Baylet, J.; Castelein, P.; Chamonal, J.-P.


    In this communication we report high performance gain characteristics measured at T=77K in electron injected MW HgCdTe APDs. A full set of characterisations, including gain, excess noise, dark current and first measurement of the impulse response, was performed on test arrays of backside illuminated pin type MW APDs, manufactured at CEA LETI using an MBE grown HgCdTe absorption layer. A record high avalanche gain of M=5300 have been demonstrated in these diodes, associated with a low noise factor, F=1.0-1.3, and low dark current. The sensistivity of the APD is discussed in terms of the impact of the distribution of the gain in the structure for different applications and we have estimated a shot noise equivalent input current, Ieq_in=2.0 10 -13 to 1.0 10 -12A, for continuous measurements, and a dark count rate for photon counting applications DCR=2.7 10 6 s -1. The first measurements of the impulse response of the MW HgCdTe APDs showed that the band width was only weakly dependent on the gain, in coherence with the dominant electron multiplication evidenced by the low value of the noise factor. At the maximum gain, M=5000, we measured a risetime of t 10-90=88ps and a fall time of t 90-10=2.4ns, yielding a record high band width product of GBW=723GHz (BW=145MHz), mainly limited by the diffusion and life time of the minority electrons.

  9. Radiography of weakly ferromagnetic metals with polarized neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael; Calzada, Elbio; Muehlbauer, Martin; Schillinger, Burkhard [FRM II, Garching (Germany); E21, Physik Department TUM, Garching (Germany); Boeni, Peter; Neubauer, Andreas; Pfleiderer, Christian [E21, Physik Department TUM, Garching (Germany)


    The depolarization of a neutron beam passing through a ferromagnet crucially depends on the magnetic properties of the sample. Combining neutron depolarisation measurements with neutron radiography allows obtaining spatially resolved information about these properties. For measuring the depolarization, we have installed a longitudinal polarized beam setup at the ANTARES beamline consisting of {sup 3}He polarizers and flat coil spin flippers. With this setup we have performed radiography with polarized neutrons in the weak itinerant ferromagnets Pd{sub 1-x}Ni{sub x} in order to determine the spatial distribution of the Curie temperatures T{sub C} in the samples. The results show that the single crystals are rather inhomogeneous showing large variations in T{sub C}. The data allows firstly to cut out small crystals with improved homogeneity for neutron scattering experiments and secondly to provide feedback for improving the growth techniques for the crystals. In the future we hope to use the potential of this method to map out magnetic domains across large volume samples.

  10. Optoelectric Properties of GaInP p-i-n Solar Cells with Different i-Layer Thicknesses

    Directory of Open Access Journals (Sweden)

    Tsung-Shine Ko


    Full Text Available The optoelectric properties of GaInP p-i-n solar cells with different intrinsic layer (i-layer thicknesses from 0.25 to 1 μm were studied. Both emission intensity and full width at half maximum features of the photoluminescence spectrum indicate that the optimum i-layer thickness would be between 0.5 and 0.75 μm. The integrated current results of photocurrent experiment also point out that the samples with 0.5 to 0.75 μm i-layer thicknesses have optimum value around 156 nA. Electroreflectance measurements reveal that the built-in electric field strength of the sample gradually deviates from the theoretical value larger when i-layer thickness of the sample is thicker than 0.75 μm. I-V measurements also confirm crystal quality for whole samples by obtaining the information about short currents of photovoltaic performances. A series of experiments reflect that thicker i-layer structure would induce more defects generation lowering crystal quality.

  11. Surface versus lateral illumination effects on an interdigitated Si planar PIN photodiode (United States)

    Menon, P. S.; Shaari, Sahbudin


    The planar PIN Photodiode (PD) has profound advantages compared to the vertical surface/edge illuminated PIN PD. A two dimensional interdigitated silicon PIN PD with a 58 microns × 80 microns active area and finger width of 2 microns and finger spacing of 10 microns respectively was modeled and simulated in a novel approach using Silvaco ATHENA and ATLAS software. The device was illuminated from the surface and laterally and comparison analysis was performed. At a reverse bias of -10 V, the dark current was 1 ps. Photocurrent of 500 nA was obtained for a 5 Wcm-2 optical beam power for both the surface and lateral illumination at a -10 V reverse bias. The total quantum efficiency of the laterally illuminated PIN PD at a wavelength of 850 nm was 95% (responsivity=0.65 A/W) and 75% (responsivity=0.52 A/W) for the surface illuminated PIN PD respectively. The -3dB cutoff frequency of the surface illuminated device was at ~10 kHz and for the laterally illuminated PIN PD, the frequency was at ~0.1 MHz. Lateral illumination in an interdigitated Si planar PIN PD produces higher photocurrent contributing to higher quantum efficiency, responsivity and frequency response as compared to surface illumination.

  12. Cdk2 and Pin1 negatively regulate the transcriptional corepressor SMRT. (United States)

    Stanya, Kristopher J; Liu, Yu; Means, Anthony R; Kao, Hung-Ying


    Silencing mediator for retinoic acid and thyroid hormone receptor (SMRT) is a transcriptional corepressor that participates in diverse signaling pathways and human diseases. However, regulation of SMRT stability remains largely unexplored. We show that the peptidyl-prolyl isomerase Pin1 interacts with SMRT both in vitro and in mammalian cells. This interaction requires the WW domain of Pin1 and SMRT phosphorylation. Pin1 regulates SMRT protein stability, thereby affecting SMRT-dependent transcriptional repression. SMRT phosphorylation at multiple sites is required for Pin1 interaction, and these sites can be phosphorylated by Cdk2, which interacts with SMRT. Cdk2-mediated phosphorylation of SMRT is required for Pin1 binding and decreases SMRT stability, whereas mutation of these phosphorylation sites abrogates Pin1 binding and stabilizes SMRT. Finally, decreases in SMRT stability occur in response to the activation of Her2/Neu/ErbB2, and this receptor functions upstream of both Pin1 and Cdk2 in the signaling cascade that regulates SMRT stability and cellular response to tamoxifen.

  13. Long-term results of transarticular pinning for surgical stabilisation of coxofemoral luxation in 20 cats. (United States)

    Sissener, T R; Whitelock, R G; Langley-Hobbs, S J


    The objective of this study was to describe initial and long-term results of open reduction and transarticular pinning for treatment of coxofemoral luxations in cats. Cats were treated by open reduction and transarticular pinning for coxofemoral luxation over a five year period at two institutions. Follow-up assessment included orthopaedic examination, radiography and owner questionnaires. Twenty cats were included in the study (14 males and six females). One cat was affected bilaterally. Mean time to follow-up was 21 months. Seventeen joints were stabilised with a 1.6 mm pin, three with 2.0 mm pins and a 1.2 mm pin was used in the remaining joint. An Ehmer sling was not utilised in any case. All transarticular pins except one were removed (mean 3.5 weeks), with all hips still in reduction The overall success rate was 77 per cent, with two reluxations and one resorbed femoral head noted on radiographs of 13 joints followed long term. All 20 owners reported good to excellent long-term functional outcome for their cats. Results from this study indicate that transarticular pinning for stabilisation of coxofemoral luxation in cats can provide a good long-term outcome without sacrificing the integrity of the coxofemoral joint.

  14. Pin-wheel hexagons: a model for anthraquinone ordering on Cu(111). (United States)

    Simenas, M; Tornau, E E


    The 4-state model of anthraquinone molecules ordering in a pin-wheel large-pore honeycomb phase on Cu(111) is proposed and solved by Monte Carlo simulation. The model is defined on a rescaled triangular lattice with the lattice constant a being equal to intermolecular distance in the honeycomb phase. The pin-wheel triangle formations are obtained taking into account the elongated shape of the molecules and anisotropic interactions for main two attractive short range (double and single dimeric) H-bond interactions. The long-range intermolecular interactions, corresponding to repulsive dipole-dipole forces, are assumed to be isotropic. Also, a very small (compared to short-range forces) isotropic attractive long-range interaction at the "characteristic" distance of a pore diameter is employed, and its effect carefully studied. This interaction is crucial for a formation of closed porous ordered systems, pin-wheel hexagons in particular. If each side of a pin-wheel hexagon is formed of n parallel molecules, the distance of this characteristic interaction is a√(3n(2)+1). The phase diagrams including different pin-wheel hexagon phases and a variety of other ordered structures are obtained. By changing the distance of characteristic interaction, different ordering routes into the experimental pin-wheel honeycomb phase are explored. The results obtained imply that classical explanation of the origin of the pin-wheel honeycomb phase in terms of some balance of attractive and repulsive forces cannot be totally discounted yet.

  15. Weak isometries of the Boolean cube


    Winter, S De; Korb, M


    Consider the metric space $\\mathcal{C}$ consisting of the $n$-dimensional Boolean cube equipped with the Hamming distance. A weak isometry of $\\mathcal{C}$ is a permutation of $\\mathcal{C}$ preserving a given subset of Hamming distances. In \\cite{Krasin} Krasin showed that in most cases preserving a single Hamming distance forces a weak isometry to be an isometry. In this article we study those weak isometries that are not automatically an isometry, providing a complete classification of weak...

  16. Pseudo-Weak-R0 Algebras

    Directory of Open Access Journals (Sweden)

    Yong Lin Liu


    Full Text Available A positive answer to the open problem of Iorgulescu on extending weak-R0 algebras and R0-algebras to the noncommutative forms is given. We show that pseudo-weak-R0 algebras are categorically isomorphic to pseudo-IMTL algebras and that pseudo-R0 algebras are categorically isomorphic to pseudo-NM algebras. Some properties, the noncommutative forms of the properties in weak-R0 algebras and R0-algebras, are investigated. The simplified axiom systems of pseudo-weak-R0 algebras and pseudo-R0 algebras are obtained.

  17. Photonic Crystal Optical Tweezers

    CERN Document Server

    Wilson, Benjamin K; Bachar, Stephanie; Knouf, Emily; Bendoraite, Ausra; Tewari, Muneesh; Pun, Suzie H; Lin, Lih Y


    Non-invasive optical manipulation of particles has emerged as a powerful and versatile tool for biological study and nanotechnology. In particular, trapping and rotation of cells, cell nuclei and sub-micron particles enables unique functionality for various applications such as tissue engineering, cancer research and nanofabrication. We propose and demonstrate a purely optical approach to rotate and align particles using the interaction of polarized light with photonic crystal nanostructures to generate enhanced trapping force. With a weakly focused laser beam we observed efficient trapping and transportation of polystyrene beads with sizes ranging from 10 um down to 190 nm as well as cancer cell nuclei. In addition, we demonstrated alignment of non-spherical particles using a 1-D photonic crystal structure. Bacterial cells were trapped, rotated and aligned with optical intensity as low as 17 uW/um^2. Finite-difference time domain (FDTD) simulations of the optical near-field and far-field above the photonic c...

  18. Downregulation of Pin1 in human atherosclerosis and its association with vascular smooth muscle cell senescence. (United States)

    Lv, Lei; Ye, Meng; Duan, Rundan; Yuan, Kai; Chen, Jiaquan; Liang, Wei; Zhou, Zhaoxiong; Zhang, Lan


    Pin1 is prevalently overexpressed in human cancers and implicated to regulate cell growth and apoptosis. Thus far, however, no role for Pin1 has been described in modulating vascular smooth muscle cell (VSMC) senescence. Immunohistochemistry and Western blotting were used to assess Pin1 protein level in human normal and atherosclerotic tissues. β-galactosidase staining, cumulative population doubling level, telomerase activity, and relative telomere length measurement were used to confirm VSMC senescence. The expressions of Pin1 and other genes involved in this research were analyzed by quantitative reverse-transcription polymerase chain reaction and Western blotting in VSMCs. Apolipoprotein E gene-deleted mice (ApoE-/-) fed a high-fat diet were treated with juglone or 10% ethanol, respectively, for 3 weeks. The extent of atherosclerosis was evaluated by Oil Red O, Masson trichrome staining, and immunohistology. Pin1 protein level decreased in human atherosclerotic tissues and VSMCs, synchronously with increased VSMC senescence. Adenoviral-mediated Pin1 overexpression rescued cellular senescence in atherosclerotic VSMCs, with concurrent down-regulation of P53, p21, growth arrest and DNA-damage-inducible protein 45-alpha (Gadd45a), phosphorylated retinoblastoma (p-pRb), p65 and upregulation of cyclin subfamilies (cyclin B, D, and E), and cyclin-dependent kinase subfamilies (2, 4, and 6), whereas Pin1 knockdown resulted in the converse effects, indicating that VSMC senescence mediated by Pin1 is an integrated response to diverse signals. In vivo data from ApoE-/- mice showed that treatment of juglone led to accelerated atherosclerosis development. Altogether this work supports a role for Pin1 as a vital modulator of VSMC senescence, thereby providing a novel target for regulation and control of atherosclerosis. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  19. Decreasing bacterial colonization of external fixation pins via nitric oxide release coatings (United States)

    Holt, Joshua; Hertzberg, Brian; Weinhold, Paul; Storm, Wesley; Schoenfisch, Mark


    Objective Bacterial infection of the pin tract represents the most common complication associated with external fixation. This study was designed to evaluate the antibacterial activity of nitric oxide (NO) releasing xerogel films applied to commercially pure titanium pins in a rat model. Methods Pins were coated with xerogel solution via a dip-coating procedure. Half of the xerogel coated implant pins were modified into NO-donors and served as the NO releasing group while the remaining pins were left unmodified to serve as non-NO releasing xerogel coated controls. Acid etched pins served as uncoated controls. Animal selection was randomized and every rat had one pin from each of the three groups randomly allocated to the 3rd, 4th, or 5th tail vertebrae. Quantification of bacterial infection was performed 48 days post-operatively and the tissue-implant interface was inspected for clinical signs of infection on days 14 and 28 post-implantation. Results Pin tract bacterial colony counts of the NO releasing group (170K±181K) were significantly lower than both the xerogel coated group (677K±675K) and the control group (1,181K±2,717K) 48 days postoperatively (pcoated group and the control group. The NO releasing group also had significantly fewer clinical signs of infection than both the coated and the control groups on postoperative day 28 (pcoatings can inhibit bacterial colonization of external fixation pins both during the initial postsurgical period and up to 48 days post-implantation. PMID:21637124

  20. Comparison of transverse wires and half pins in Taylor Spatial Frame: a biomechanical study. (United States)

    Khurana, Ashish; Byrne, Carlton; Evans, Sam; Tanaka, Hiro; Haraharan, Kartik


    The aim of this study was to compare the stiffness characteristics of Taylor Spatial Frame (TSF) fixed with transverse wires and half pins. Experiments were carried out at the biomechanics laboratory at Cardiff University. All mechanical testing was performed with a servo hydraulic test frame (MTS 858 Mini Bionix II(R), MTS Corp., Mineapolis, USA). Custom built mounts were used to attach the bone rigidly to the one end of machine and the TSF ring to the other. Rings were fixed with 1.8 mm transverse wires or hydroxy-apatite coated 6.5 mm half pins in 45 degrees, 60 degrees, 75 degrees and 90 degrees divergence angles. Bone was loaded with axial load to 400 N and torque to 20 Nm in an indestructible manner. Load/displacement curve data were analyzed for slope and axial and angular displacements. For larger diameter rings (180 mm), for axial stiffness there was no statistically significant difference between the transverse wires (4 wires with 2 rings) and the half pins (2 pins with 1 ring) (p > 0.05). For 155 mm internal diameter rings, half pins provided statistically higher axial stiffness than transverse wires (p = 0.036). The half pins show significantly more torsion stiffness in both ring diameters (p < 0.05) in comparison to transverse wires. As in axial stiffness, small diameter rings show increased stiffness in torsion. There is increase in axial and torsion stiffness with the increase in the divergence angle between the wires or pins (p < 0.05). Half pins provide greater stiffness to TSF frames and allow for axial micro motion as well. This work provides a rationale for clinical decision making about the use of tensioned transverse wires in comparison to half pins in construction of a TSF frame.

  1. Halo skeletal traction pin site care: toward developing a standard of care. (United States)

    Olson, R S


    Halo skeletal traction may be used to immobilize a patient's head and neck following a cervical fracture. Prevention of infectious reactions around the pin sites of halo traction is a priority in rehabilitation nursing practice. Although prophylactic treatment of skeletal pin sites is a generally accepted practice, there is great diversity of opinion and very limited systematic investigation as to how the sites should be treated. In this article, the author reviews the literature on pin site care and suggests a protocol based on the current literature.

  2. Cooling system having reduced mass pin fins for components in a gas turbine engine (United States)

    Lee, Ching-Pang; Jiang, Nan; Marra, John J


    A cooling system having one or more pin fins with reduced mass for a gas turbine engine is disclosed. The cooling system may include one or more first surfaces defining at least a portion of the cooling system. The pin fin may extend from the surface defining the cooling system and may have a noncircular cross-section taken generally parallel to the surface and at least part of an outer surface of the cross-section forms at least a quartercircle. A downstream side of the pin fin may have a cavity to reduce mass, thereby creating a more efficient turbine airfoil.

  3. Thick and large area PIN diodes for hard X-ray astronomy

    CERN Document Server

    Ota, N; Sugizaki, M; Kaneda, M; Tamura, T; Ozawa, H; Kamae, T; Makishima, K; Takahashi, T; Tashiro, M; Fukazawa, Y; Kataoka, J; Yamaoka, K; Kubo, S; Tanihata, C; Uchiyama, Y; Matsuzaki, K; Iyomoto, N; Kokubun, M; Nakazawa, T; Kubota, A; Mizuno, T; Matsumoto, Y; Isobe, N; Terada, Y; Sugiho, M; Onishi, T; Kubo, H; Ikeda, H; Nomachi, M; Ohsugi, T; Muramatsu, M; Akahori, H


    Thick and large area PIN diodes for the hard X-ray astronomy in the 10-60 keV range are developed. To cover this energy range in a room temperature and in a low background environment, Si PIN junction diodes of 2 mm in thickness with 2.5 cm sup 2 in effective area were developed, and will be used in the bottom of the Phoswich Hard X-ray Detector (HXD), on-board the ASTRO-E satellite. Problems related to a high purity Si and a thick depletion layer during our development and performance of the PIN diodes are presented in detail.

  4. Normograde and retrograde pinning of the distal fragment in humeral fractures of the dog. (United States)

    Milgram, Joshua; Hod, Nitai; Benzioni, Hadas


    To determine if normograde and retrograde pinning of the distal humeral fragment, to maximize pin purchase in this fragment, would damage vital structures in and around the elbow and shoulder joints in dogs. Anatomic study. Cadaveric dogs (n = 12; 12 thoracic limb pairs). Twelve thoracic limb pairs were harvested from cross-breed dogs and 1 thoracic limb from each pair was allocated to 1 of 3 groups. A transverse osteotomy was created at the junction of the middle and distal thirds in the diaphyseal fracture group (n = 8) and proximal to the supracondylar foramen in the metaphyseal fracture group (n = 8). The humeri in the normograde group (n = 8) were left intact. In all specimens in the distal and supracondylar fracture groups, retrograde pinning of the distal fragment was performed with the elbow flexed. The pins were driven into the medial epicondyle until they exited the skin caudal to the elbow. Dissection of the soft tissues around the exit tract of the pin was performed. The fracture was then reduced and the pin was advanced until it exited the proximal humeral fragment. In the specimens in the normograde group, pinning was initiated on the distal aspect of the medial epicondyle. The pin was directed parallel to the caudal aspect of the medial epicondyle and driven proximally into the humerus until it exited the proximal humerus. Pins exiting the distal aspect of the medial epicondyle passed through muscle origins in 7 specimens in the diaphyseal osteotomy group and in all 8 specimens in the metaphyseal group. The ulnar nerve was entrapped in 1 specimen in the metaphyseal osteotomy group; however, it was not entrapped in any of the specimens in the diaphyseal osteotomy group. The articular cartilage of the trochlea was damaged in 2 specimens in each of the retrograde pinned groups. There was no damage to articular or periarticular structures by pins exiting the proximal humerus. Retrograde pinning of the distal fragment in humeral fractures in the dog may

  5. Graph Theory-Based Pinning Synchronization of Stochastic Complex Dynamical Networks. (United States)

    Li, Xiao-Jian; Yang, Guang-Hong


    This paper is concerned with the adaptive pinning synchronization problem of stochastic complex dynamical networks (CDNs). Based on algebraic graph theory and Lyapunov theory, pinning controller design conditions are derived, and the rigorous convergence analysis of synchronization errors in the probability sense is also conducted. Compared with the existing results, the topology structures of stochastic CDN are allowed to be unknown due to the use of graph theory. In particular, it is shown that the selection of nodes for pinning depends on the unknown lower bounds of coupling strengths. Finally, an example on a Chua's circuit network is given to validate the effectiveness of the theoretical results.

  6. The Pinning by Particles of Low and High Angle Grain Boundaries during Grain Growth

    DEFF Research Database (Denmark)

    Tweed, C.J.; Ralph, B.; Hansen, Niels


    and coworkers. These estimates of local driving pressures have shown that they are similar for both the low and the high angle boundaries encountered in the samples. The pinning effects by particles at high angle boundaries are in general accord with the model due to Zener whilst those at low angle boundaries......A study has been made using transmission electron microscopy of the pinning of grain boundaries in aluminium during grain growth by fine dispersions of alumina particles. The boundary parameters have been determined with precision and the pinning effects measured using an approach due to Ashby...

  7. Hysteretic rotational magnetization of pinned layer in NiO spin-valve

    CERN Document Server

    Kim, C G; Hwang, D G; Lee, S S; Kim, C O


    The magnetoresistance (MR) curves during the rotation of magnetic field in NiO spin-valve are well described by taking into account the involved magnetization process of free and pinned layers according to rotating field strength. In particular, hysteretic MR characteristics pronounced in a field strength of 1.5 times the exchange field are ascribed for by the viscosity effect on magnetization rotation of pinned layer. These analyses of MR curves provide a basis decomposing the MR components from each magnetization process of free and pinned layers.

  8. Skyrmion-Based Dynamic Magnonic Crystal. (United States)

    Ma, Fusheng; Zhou, Yan; Braun, H B; Lew, W S


    A linear array of periodically spaced and individually controllable skyrmions is introduced as a magnonic crystal. It is numerically demonstrated that skyrmion nucleation and annihilation can be accurately controlled by a nanosecond spin polarized current pulse through a nanocontact. Arranged in a periodic array, such nanocontacts allow the creation of a skyrmion lattice that causes a periodic modulation of the waveguide's magnetization, which can be dynamically controlled by changing either the strength of an applied external magnetic field or the density of the injected spin current through the nanocontacts. The skyrmion diameter is highly dependent on both the applied field and the injected current. This implies tunability of the lowest band gap as the skyrmion diameter directly affects the strength of the pinning potential. The calculated magnonic spectra thus exhibit tunable allowed frequency bands and forbidden frequency bandgaps analogous to that of conventional magnonic crystals where, in contrast, the periodicity is structurally induced and static. In the dynamic magnetic crystal studied here, it is possible to dynamically turn on and off the artificial periodic structure, which allows switching between full rejection and full transmission of spin waves in the waveguide. These findings should stimulate further research activities on multiple functionalities offered by magnonic crystals based on periodic skyrmion lattices.

  9. GERMINAL — A computer code for predicting fuel pin behaviour (United States)

    Melis, J. C.; Roche, L.; Piron, J. P.; Truffert, J.


    In the frame of the R and D on FBR fuels, CEA/DEC is developing the computer code GERMINAL to study the fuel pin thermal-mechanical behaviour during steady-state and incidental conditions. The development of GERMINAL is foreseen in two steps: (1) The GERMINAL 1 code designed as a "working horse" for immediate applications. The version 1 of GERMINAL 1 is presently delivered fully documented with a physical qualification guaranteed up to 8 at%. (2) The version 2 of GERMINAL 1, in addition to what is presently treated in GERMINAL 1 includes the treatment of high burnup effects on the fission gas release and the fuel-clad joint. This version, GERMINAL 1.2, is presently under testing and will be completed up to the end of 1991. The GERMINAL 2 code designed as a reference code for future applications will cover all the aspects of GERMINAL 1 (including high burnup effects) with a more general mechanical treatment, and a completely revised and advanced informatical structure.

  10. Fast recovery SOI PiN diode with multiple trenches (United States)

    Zhang, Long; Zhu, Jing; Zhao, Minna; Ding, Desheng; Chen, Jian; Sun, Weifeng


    In this paper, a 500V SOI PiN lateral diode is proposed and investigated by simulations and experiments. The proposed structure features multiple deep-oxide trenches (MDOT) arranged in the silicon region. Two DOTs (T1 and T2) locating in the i-layer help to block the cathode-anode voltage (VCA), allowing the diode to shorten its i-layer length. With a similar breakdown voltage (BV) of 560V, the i-layer length is shortened from 47 μm for the conventional diode to 21.9 μm for the proposed MDOT diode. The shortened i-layer leads to a reduced number of stored carriers in the i-layer. Another DOT (T3) is inserted at the anode region of proposed MDOT diode and shorted with P+ anode. T3 acts as a vertical field plate, reshaping the electric potential distribution at the anode region and accelerating the depletion during the reverse recovery process. Thanks to the decreased number of the stored carriers and the accelerated depletion, the reverse recovery time (trr) of the proposed MDOT diode (211 ns) can be decreased by 56.7% compared with the conventional diode (487 ns) at the forward current density of 400 A/cm2 at T = 300 K. The proposed MDOT diode exhibits a better trade-off between forward voltage drop (VF) and reverse recovery time (trr) than the conventional and other reported diodes.

  11. Masses of exotic calcium isotopes pin down nuclear forces. (United States)

    Wienholtz, F; Beck, D; Blaum, K; Borgmann, Ch; Breitenfeldt, M; Cakirli, R B; George, S; Herfurth, F; Holt, J D; Kowalska, M; Kreim, S; Lunney, D; Manea, V; Menéndez, J; Neidherr, D; Rosenbusch, M; Schweikhard, L; Schwenk, A; Simonis, J; Stanja, J; Wolf, R N; Zuber, K


    The properties of exotic nuclei on the verge of existence play a fundamental part in our understanding of nuclear interactions. Exceedingly neutron-rich nuclei become sensitive to new aspects of nuclear forces. Calcium, with its doubly magic isotopes (40)Ca and (48)Ca, is an ideal test for nuclear shell evolution, from the valley of stability to the limits of existence. With a closed proton shell, the calcium isotopes mark the frontier for calculations with three-nucleon forces from chiral effective field theory. Whereas predictions for the masses of (51)Ca and (52)Ca have been validated by direct measurements, it is an open question as to how nuclear masses evolve for heavier calcium isotopes. Here we report the mass determination of the exotic calcium isotopes (53)Ca and (54)Ca, using the multi-reflection time-of-flight mass spectrometer of ISOLTRAP at CERN. The measured masses unambiguously establish a prominent shell closure at neutron number N = 32, in excellent agreement with our theoretical calculations. These results increase our understanding of neutron-rich matter and pin down the subtle components of nuclear forces that are at the forefront of theoretical developments constrained by quantum chromodynamics.

  12. [Biological basis of problematic internet use (PIN) and therapeutic implications]. (United States)

    Bauernhofer, Kathrin; Papousek, Ilona; Fink, Andreas; Unterrainer, Human Friedrich; Weiss, Elisabeth M


    The repetitive excessive use of internet has led to an increasing number of reports about the negative consequences of overuse and is now viewed as an important public health issue, although the diagnosis of internet addiction remains problematic. Increasing knowledge about the neurobiological mechanism of behavioral addictions will promote future research and is essential for the development of specific and effective treatment. Growing evidence suggests that the neurobiological substrates and pathways of internet addiction resemble those of substance dependency and other forms of behavioral addictions. This paper reviews the current neuroimaging findings and genetic influencing factors for problematic internet use (PIN)/internet addiction. Recent evidence from neuro-scientific studies has pointed out that certain dysfunctions in the prefrontal cortex possibly driven by impaired dopamine neurotransmission are related to symptoms of internet addiction. Finally the literature on psychological and pharmacological interventions for internet addiction will be discussed. However, due to a lack of methodological sound treatment studies in this field it is currently impossible to recommend any evidence-based treatment of internet addiction.

  13. Critical currents in proton irradiated YBa sub 2 Cu sub 3 O sub 7-. delta. crystals

    Energy Technology Data Exchange (ETDEWEB)

    Civale, L.; McElfresh, M.W.; Marwick, A.D.; Worthington, T.K.; Malozemoff, A.P.; Holtzberg, F.; Feild, C. (International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center); Thompson, J.R.; Christen, D.K. (Oak Ridge National Lab., TN (USA)); Kirk, M.A. (Argonne National Lab., IL (USA))


    A large enhancement in the critical current of YBaCuO crystals in magnetic field is observed after irradiation with 3 MeV protons. Critical current densities with values up to 2 {times} 10{sup 5} A/cm{sup 2} at 77 K and 1 T are observed. TEM studies show the presence of isolated clusters of defects after irradiation; however, an analysis of the critical current scaling indicates that these clusters are not the dominant pinning sites. The dose dependence of the current density suggests that the pinning is dominated by the randomly distributed point defects generated by the protons and can be described by a collective pinning model in the amorphous limit. 24 refs., 7 figs.

  14. The behavior of commensurate-incommensurate transitions using the phase field crystal model (United States)

    Zhang, Tinghui; Lu, Yanli; Chen, Zheng


    We study the behavior of the commensurate-incommensurate (CI) transitions by using a phase field crystal model. The model is capable of modeling both elastic and plastic deformation and can simulate the evolution of the microstructure of the material at the atomic scale and the diffusive time scale, such as for adsorbed monolayer. Specifically, we study the behavior of the CI transitions as a function of lattice mismatch and the amplitude of substrate pinning potential. The behavior of CI phase transitions is revealed with the increase of the amplitude of pinning potential in some certain lattice mismatches. We find that for the negative lattice mismatch absorbed monolayer undergoes division, reorganization and displacement as increasing the amplitude of substrate pinning potential. In addition, for the positive mismatch absorbed monolayer undergoes a progress of phase transformation after a complete grain is split. Our results accord with simulations for atomic models of absorbed monolayer on a substrate surface.

  15. A classification of weakly acyclic games

    NARCIS (Netherlands)

    Apt, K.R.; Simon, S.


    Weakly acyclic games form a natural generalization of the class of games that have the finite improvement property (FIP). In such games one stipulates that from any initial joint strategy some finite improvement path exists. We classify weakly acyclic games using the concept of a scheduler recently

  16. Revisiting Weak Simulation for Substochastic Markov Chains

    DEFF Research Database (Denmark)

    Jansen, David N.; Song, Lei; Zhang, Lijun


    The spectrum of branching-time relations for probabilistic systems has been investigated thoroughly by Baier, Hermanns, Katoen and Wolf (2003, 2005), including weak simulation for systems involving substochastic distributions. Weak simulation was proven to be sound w.r.t. the liveness fragment...

  17. A note on Weak Stability Boundaries


    García González, Fernando; Gómez Muntané, Gerard


    This paper is devoted to clarify the algorithmic definition of the weak stability boundary in the framework of the planar Restricted Three Body Problem. The role of the invariant hyperbolic manifolds associated to the central manifolds of the libration points L1 and L2, as boundary of the weak stability region, is shown Peer Reviewed

  18. CP Violation, Neutral Currents, and Weak Equivalence (United States)

    Fitch, V. L.


    Within the past few months two excellent summaries of the state of our knowledge of the weak interactions have been presented. Correspondingly, we will not attempt a comprehensive review but instead concentrate this discussion on the status of CP violation, the question of the neutral currents, and the weak equivalence principle.

  19. Towards a classification of weak hand holds

    NARCIS (Netherlands)

    Kimmelman, V.; Sáfár, A.; Crasborn, O.


    The two symmetrical manual articulators (the hands) in signed languages are a striking modalityspecific phonetic property. The weak hand can maintain the end position of an articulation while the other articulator continues to produce additional signs. This weak hand spreading (hold) has been

  20. Spin Seebeck effect in a weak ferromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Arboleda, Juan David, E-mail:; Arnache Olmos, Oscar [Instituto de Física, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Aguirre, Myriam Haydee; Ibarra, Manuel Ricardo [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Laboratorio de Microscopías Avanzadas, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Ramos, Rafael [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Sendai 980-8577 (Japan); Anadon, Alberto [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain)


    We report the observation of room temperature spin Seebeck effect (SSE) in a weak ferromagnetic normal spinel Zinc Ferrite (ZFO). Despite the weak ferromagnetic behavior, the measurements of the SSE in ZFO show a thermoelectric voltage response comparable with the reported values for other ferromagnetic materials. Our results suggest that SSE might possibly originate from the surface magnetization of the ZFO.

  1. On modeling weak sinks in MODPATH (United States)

    Abrams, Daniel B.; Haitjema, Henk; Kauffman, Leon J.


    Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that water to pass. A physical strong sink can be modeled by either a strong sink cell or a weak sink cell, with the latter generally occurring in low resolution models. Likewise, a physical weak sink may also be represented by either type of sink cell. The representation of weak sinks in the particle tracing code MODPATH is more equivocal than in MODFLOW. With the appropriate parameterization of MODPATH, particle traces and their associated travel times to weak sink streams can be modeled with adequate accuracy, even in single layer models. Weak sink well cells, on the other hand, require special measures as proposed in the literature to generate correct particle traces and individual travel times and hence capture zones. We found that the transit time distributions for well water generally do not require special measures provided aquifer properties are locally homogeneous and the well draws water from the entire aquifer depth, an important observation for determining the response of a well to non-point contaminant inputs.

  2. Intensive care unit-acquired weakness

    NARCIS (Netherlands)

    Horn, J.; Hermans, G.


    When critically ill, a severe weakness of the limbs and respiratory muscles often develops with a prolonged stay in the intensive care unit (ICU), a condition vaguely termed intensive care unit-acquired weakness (ICUAW). Many of these patients have serious nerve and muscle injury. This syndrome is

  3. Crystallization, optimization and preliminary X-ray characterization of a metal-dependent PI-PLC from Streptomyces antibioticus

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Michael R.; Selby, Thomas L.


    A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) fromStreptomyces antibioticushas been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space groupP222, with unit-cell parametersa= 41.26,b= 51.86,c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution.

  4. Persisting weakness after withdrawal of a statin. (United States)

    Mygland, Åse; Ljøstad, Unn; Krossnes, Bård Kronen


    An 81-year-old woman treated with simvastatin for several years followed by atorvastatin for about 1 year presented with fatigue, weakness and unsteady gait. The finding of elevated creatine kinase (CK) and symmetric muscle weakness around shoulders and hips led to suspicion of a toxic statin-associated myopathy. Atorvastatin was withdrawn, but her weakness persisted. Owing to persisting weakness, an autoimmune myopathy (myositis) was suspected, but initially disregarded since a muscle biopsy showed necrotic muscle fibres without inflammatory cell infiltrates and myositis-specific autoantibodies were absent. After 18 months with slowly progressive weakness and increasing CK values, awareness of new knowledge about autoimmunity as a cause of necrotic myopathy, led to a successful treatment trial with intravenous immunoglobulines, followed by steroids and metothrexate. Antibodies to the target enzyme of statins (HMGCR (3-hydroksy-3-methylglutaryl-coenzyme A reductase)) were detected in her serum, and she was diagnosed with autoimmune necrotic myositis probably triggered by atorvastatin.

  5. Thermal stress analyses of a header plate with a 51-PIN electrical feed-thru

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, V.L.; McCollister, H.L.


    An electronic package currently under development requires a hermetically-sealed electrical connection through a metal header plate. The electrical feedthru consists of 51 RA333 pins in an S-type glass ceramic insulator. Because the feedthru contains a large number of pins spaced closely together, a single glass preform rather than individual glass beads at each pin has been proposed. Finite element analyses were conducted to gain insight into the stress distribution in the header plate, glass, and pins. To verify the finite element analyses, a prototype part was manufactured and examined for cracking in the glass ceramic and for leakage of the glass-to-metal seal. Finite element analyses were then used to investigate effects of the plate geometry and yield strength on stresses in the assembly. This paper illustrates one way that finite element analyses can be used along with selective prototype manufacturing for a timely and cost-effective method of evaluating design parameters of electronic packages.

  6. Seal assembly with anti-rotation pin for high pressure supercritical fluids (United States)

    Wright, Steven A.; Fuller, Robert L.


    A seal assembly for sealing a machine with a first chamber and a second chamber is provided. A rotating shaft extends through the first and second chambers, and rotates therein. The seal assembly has a seal housing, a seal ring and a seal pin. The seal housing is positionable in the machine housing. The seal housing has a seal pocket extending into a fluid side thereof, and a housing receptacle extending into an inner diameter thereof at the seal pocket. The seal ring is positionable in the seal pocket of the seal housing for forming a seal therewith. The seal ring has a ring receptacle extending into an outer diameter thereof. The ring receptacle is positionable adjacent to the housing receptacle for defining a pin hole therebetween. The seal pin is loosely positionable in the pin hole whereby movement about the seal ring is accommodated while preventing rotation thereof.

  7. Profile design of loaded pins in composite single lap joints: From circular to non-circular (United States)

    Zhou, Yadong; Fei, Qingguo; Tao, Jiayue

    Mechanical joints are the weakest links of composite materials and structures. The aim of this study is to investigate the effect of the pin profiles on the stress concentration and load-carry capacity of the pin-loaded single-lap joints subjected to tensile loading. Non-circular profiles of pins are numerically investigated to pursue a possible stress concentration reduction in both the net-tension and bearing stresses of composite single lap joints. Firstly, by varying the characteristic parameters, various round-corner squares are evaluated in terms of peak stresses. Secondly, the square-like profile is transferred to the racetrack-like one in order to gain optimal bearing stresses. Thirdly, the pin of the racetrack-like profile is investigated compared to the circular one, taking into account the through-thickness distributions of stresses. Lastly, the orthotropic effect and the load-carry capacity of the proposed profile are also discussed.

  8. Correlation Between Pin Misalignment and Crack Length in THT Solder Joints

    Directory of Open Access Journals (Sweden)

    Molnar A.


    Full Text Available In this manuscript, correlations were searched for between pin misalignments relative to PCB bores and crack propagation after cyclic thermal shock tests in THT solder joints produced from lead-free solder alloys. In total, 7 compositions were examined including SAC solders with varying Ag, Cu and Ni contents. The crack propagation was initiated by cyclic thermal shock tests with 40°C / +125°C temperature profiles. Pin misalignments relative to the bores were characterized with three attributes obtained from one section of the examined solder joints. Cracks typically originated at the solder/pin or solder/bore interfaces and propagated within the solder. It was shown that pin misalignments did not have an effect on crack propagation, thus, the solder joints’ lifetime.

  9. Three-dimensional flow phenomena in a wire-wrapped 37-pin fuel bundle for SFR

    National Research Council Canada - National Science Library

    Jeong, Jae-Ho; Yoo, Jin; Lee, Kwi-Lim; Ha, Kwi-Seok


    Three-dimensional flow phenomena in a wire-wrapped 37-pin fuel assembly mock-up of a Japanese loop-type sodium-cooled fast reactor, Monju, were investigated with a numerical analysis using a general...

  10. Pinning Properties of Commercial Nb-Ti Wires Described by a 2-Components Model

    CERN Document Server

    Muzzi, L; Zignani, Chiarasole Fiamozzi; De Marzi, Gianluca; Muzzi, Luigi; Dominguez, Cesar Octavio; Bottura, Luca; Napolitano, Mathieu; Viola, Rosario; Affinito, Luigi; della Corte, Antonio; Le Naour, Sandrine


    We report on the magnetic and transport characterization of different NbTi commercial strands, carried out at variable temperature and magnetic field. From the critical current densities extracted from transport measurements and magnetization cycles we were able to calculate the normalized bulk pinning forces. The curves show good temperature scaling throughout the explored temperature range, and the reduced pinning force can be described by a simple two-components model system. The extension of the 2-components description of the pinning force to an expression for the critical current density gives a very good agreement with experimental measurements over the whole explored B, T range. The model works for all investigated samples, which are different in size, Cu:nonCu ratios, filament diameters and layouts. These results suggest that pinning mechanisms in conventional NbTi strands should be revised, since Nb-Ti composition gradients and grain boundaries seems to play a not negligible role.

  11. Why Do We Pin? New Gratifications Explain Unique Activities in Pinterest

    National Research Council Canada - National Science Library

    Wang, Ruoxu; Yang, Fan; Zheng, Saijing; Sundar, S. Shyam


    .... This study investigated why individuals use specific features of Pinterest such as pinning, creating, liking, following, commenting, inviting, sharing, checking, searching, and browsing different categories. An online survey (N = 113...

  12. Self-regulation of charged defect compensation and formation energy pinning in semiconductors

    National Research Council Canada - National Science Library

    Yang, Ji-Hui; Yin, Wan-Jian; Park, Ji-Sang; Wei, Su-Huai


    ... as the defect states in practice; (2) defect formation energy, thus defect density, could be pinned and independent on atomic chemical potentials due to the entanglement of atomic chemical potentials and Fermi energy, in contrast...

  13. In-situ tunable vortex pinning with an array of ferromagnetic anti-dots (United States)

    Wang, Yong-Lei; Xiao, Zhili; Ocola, Leo; Divan, Ralu; Crabtree, George W.; Kwok, Wai-Kwong; Superconductivity and Magnetism Group, MSD, Argonne National Lab Team


    We investigated vortex pinning effects of a ferromagnetic antidot array in a superconducting film. A square antidot array of 30 nm thick permalloy (Py) was patterned onto a MoGe superconducting film with thickness of 100 nm. Although we found no evidence of vortex pinning enhancement by the pristine magnetic antidot array in perpendicular magnetic fields, we found that by applying an independently controlled in-plane magnetic field the magnetic antidot array can provide excellent vortex pinning, resulting in a tunable superconducting critical current enhancement. Through micromagnetic simulation and magnetic force microscopy imaging, we demonstrate that the tunable vortex pinning originates from spatially periodic stray field generated by the magnetic antidot array in the presence of an in-plane magnetic field. This work was supported by DOE BES under Contract No. DE-AC02-06CH11357 that also funds Argonne's Center for Nanoscale Materials (CNM) where the nanopatterning was performed.

  14. Flux pinning mechanism and Hc2-anisotropy in melanin doped bulk MgB2 (United States)

    Shahabuddin Shah, M.; Shahabuddin, Mohammed; Alzayed, Nasser S.; Parakkandy, Jafar M.


    Flux pinning mechanism in melanin doped MgB2 superconductor has been studied using a scaling law proposed by Dew-Hughes and another method proposed by Eisterer. Our experimental data could be fitted very closely by the aforementioned scaling law. The fitting parameters, the positions of peaks bpeak and k = bpeak/bn confirm a grain-boundary pinning in the 10% melanin doped sample, while the undoped sample consists of mixed pinning. Furthermore, percolation theory was utilized under grain-boundary approximation to investigate the role of Hc2-anisotropy in the critical current density, and its dependence on applied field as well as temperature. The Hc2-anisotropy decreases with melanin doping resulting in the increase of Jc in high field. There is suppression of flux pinning maximum due to melanin doping, which is found to be the main reason for the degradation of low-field Jc.

  15. Global synchronization of memristive neural networks subject to random disturbances via distributed pinning control. (United States)

    Guo, Zhenyuan; Yang, Shaofu; Wang, Jun


    This paper presents theoretical results on global exponential synchronization of multiple memristive neural networks in the presence of external noise by means of two types of distributed pinning control. The multiple memristive neural networks are coupled in a general structure via a nonlinear function, which consists of a linear diffusive term and a discontinuous sign term. A pinning impulsive control law is introduced in the coupled system to synchronize all neural networks. Sufficient conditions are derived for ascertaining global exponential synchronization in mean square. In addition, a pinning adaptive control law is developed to achieve global exponential synchronization in mean square. Both pinning control laws utilize only partial state information received from the neighborhood of the controlled neural network. Simulation results are presented to substantiate the theoretical results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Pinning of scroll waves to flat and highly branched unexcitable heterogeneities (United States)

    Mahanta, Dhriti; Dutta, Sumana; Steinbock, Oliver


    System heterogeneities such as organelles, cells, and anatomical features strongly affect nonlinear wave patterns in biological systems. These effects are more readily studied in otherwise homogeneous chemical reactions that allow the introduction of tailored structures. Following this approach, we investigate the dynamics of three-dimensional excitation vortices pinned to inert sheets with circular holes arranged on a hexagonal lattice. Experiments with the Belousov-Zhabotinsky reaction and numerical simulations of an excitable reaction-diffusion model reveal vortex pinning that circumvents the rapid collapse of free vortex rings. The pinned scroll waves are affected by the topological mismatch between their looplike rotation backbone and the branched pinning structure. Depending on the initial condition, a multitude of stable vortex states exist, all of which obey topological constraints, suggesting spinlike states for the involved obstacle holes.

  17. Characterization of an Mg-implanted GaN p-i-n Diode (United States)


    Characterization of an Mg- implanted GaN p-i-n Diode Travis J. Anderson, Jordan D. Greenlee, Boris N. Feigelson, Karl D. Hobart, and Francis J...Kub Naval Research Laboratory, Washington, DC 20375 Abstract: A p-i-n diode formed by the implantation of Mg in GaN was fabricated and...characterized. After implantation , Mg was activated using the symmetrical multicycle rapid thermal annealing technique with heating pulses up to 1340C

  18. A Study on Fracture Resistance of Class IV Cavities Treated with Pins

    Directory of Open Access Journals (Sweden)

    Boteva E.


    Full Text Available Тhе use of pins in restoration of large cavities with esthetic resin materials appear in the dental literature after 1970 and there are less than 20 publications, focused around restorations of class IV cavities. The aim of the present study is to test the role of pins in the fracture resistance in class IV restorations with resin materials. Materials and methods: 68 matured human upper and lower sound front teeth are included in the study. The groups are upper incisors, lower incisors, canines with or without pins. All cavities are filled with the same resin material, technology and Prime bond NT. Termocycling: 30 days in 30ºС, 100% humidity, 60 days in 100% humidity 2Х12 hours at 35ºС and 40ºС and 100 dry cycles, 20 seconds each in the following order - 45ºС ± 3ºС, room temperature, 5ºС, room temperature, two series, 50 each with two days between in Cultura incubator of Viva Dent 55ºС and ice. Machine for vertical load testing ZD 10/90, load in Newtons (N, from 20 N to 1275 N, speed 0.5 mm/ min, displacement from 0.1 to 1.2 mm. Type of fractures observed: adhesive, cohesive in dentine and in resin material, mixed. Results: The highest proportion of fractures observed was in front teeth with large cavities and with pins, low loading (493-503N. Front teeth with large cavities without pins have better resistance and lower proportion of fractures (488-526N. Canines are more resistible with pins and less without. Lowest resistance is found in lower front teeth when pins are present. Conclusion: In class IV restorations when tissue loses are less than 2/3 of the incisal ridge pins can decrease the fracture resistance of the teeth.

  19. Rigid levitation, flux pinning, thermal depinning and fluctuation in high-Tc superconductors (United States)

    Brandt, E. H.


    Here, the author shows that the strong velocity-independent frictional force on a levitating superconductor and on any type-II superconductor moving in a homogeneous magnetic field is caused by pinning and depinning of the magnetic flux lines in its interior. Levitation may thus be used to investigate the pinning properties of a superconductor, and friction in a superconductor bearing may be minimized by choosing appropriate materials and geometries.

  20. Temperature Distributions in LMR Fuel Pin Bundles as Modeled by COBRA-IV-I (United States)

    Wright, Steven A.; Stout, Sherry


    Most pin type reactor designs for space power or terrestrial applications group the fuel pins into a number of relatively large fuel pin bundles or subassemblies. Fuel bundles for terrestrial liquid metal fast breeders reactors typically use 217 - 271 pins per sub-assembly, while some SP100 designs use up to 331 pins in a central subassembly that was surrounded by partial assemblies. Because thermal creep is exponentially related to temperature, small changes in fuel pin cladding temperature can make large differences in the lifetime in a high temperature liquid metal reactor (LMR). This paper uses the COBRA-IV-I computer code to determine the temperature distribution within LMR fuel bundles. COBRA-IV-I uses the sub-channel analysis approach to determine the enthalpy (or temperature) and flow distribution in rod bundles for both steady-state and transient conditions. The COBRA code runs in only a few seconds and has been benchmarked and tested extensively over a wide range of flow conditions. In this report the flow and temperature distributions for two types of lithium cooled space reactor core designs were calculated. One design uses a very tight fuel pin packing that has a pitch to diameter ratio of 1.05 (small wire wrap with a diameter of 392 μm) as proposed in SP100. The other design uses a larger pitch to diameter ratio of 1.09 with a larger more conventional sized wire wrap diameter of 1 mm. The results of the COBRA pin bundle calculations show that the larger pitch-to-diameter fuel bundle designs are more tolerant to local flow blockages, and in addition they are less sensitive to mal-flow distributions that occur near the edges of the subassembly.

  1. Biomechanical evaluation of a toggle pin technique for management of coxofemoral luxation. (United States)

    Flynn, M F; Edmiston, D N; Roe, S C; Richardson, D C; DeYoung, D J; Abrams, C F


    Toggle pin stabilization is an accepted technique for the management of coxofemoral (CF) luxation in dogs. The purpose of this study was to determine, in vitro, the respective contributions of several aspects of toggle pin repair to the overall stability of fixation. Factors evaluated were the manner and frequency with which toggle pins oriented on insertion, effect of orientation on toggle pin strength, effect of suture type on ligament prosthesis strength and load sustained by the fixation, and comparison of repair using a modified toggle design to that of capsulorrhaphy. When placed in cadavers using standard technique, conventional toggle pins were found to orient significantly more frequently in one of two possible positions. Mechanical testing of fixations performed in experimentally luxated cadaver hips demonstrated a high (12/20) incidence of toggle pin failure using the conventional implant in the most common orientation. When tested alone, toggle pins were weakest mechanically in this orientation. Rotating the implant 180 degrees increased mean load to failure by 249%. There was no significant difference in load sustained by conventional toggle fixations using No. 2 braided polyester versus 50 lb test monofilament nylon as the suture ligament prosthesis. However, the higher stiffness of the polyester suture may be more favorable for use in this application. Fixation using a toggle rod designed to allow evaluation of construct stability when failure of the toggle is eliminated resulted in an increase in maximum load sustained before luxation (47% of the intact control hips). This load was not significantly different than the resistance to luxation afforded by capsulorrhaphy. This study suggests that when implanting conventional toggle pins, consideration should be given to ensuring placement in the strongest orientation.

  2. Surface barrier and bulk pinning in MgB$_2$ superconductor


    Pissas, M.; Moraitakis, E.; Stamopoulos, D.; Papavassiliou, G.; Psycharis, V.; Koutandos, S.


    We present a modified method of preparation of the new superconductor MgB$_2$. The polycrystalline samples were characterized using x-ray and magnetic measurements. The surface barriers control the isothermal magnetization loops in powder samples. In bulk as prepared samples we always observed symmetric magnetization loops indicative of the presence of a bulk pinning mechanism. Magnetic relaxation measurements in the bulk sample reveal a crossover of surface barrier to bulk pinning.

  3. Comparison of transverse wires and half pins in Taylor Spatial Frame: A biomechanical study

    Directory of Open Access Journals (Sweden)

    Tanaka Hiro


    Full Text Available Abstract Background The aim of this study was to compare the stiffness characteristics of Taylor Spatial Frame (TSF fixed with transverse wires and half pins. Design & Methods Experiments were carried out at the biomechanics laboratory at Cardiff University. All mechanical testing was performed with a servo hydraulic test frame (MTS 858 Mini Bionix II(R, MTS Corp., Mineapolis, USA. Custom built mounts were used to attach the bone rigidly to the one end of machine and the TSF ring to the other. Rings were fixed with 1.8 mm transverse wires or hydroxy-apatite coated 6.5 mm half pins in 45degrees, 60degrees, 75degrees and 90degrees divergence angles. Bone was loaded with axial load to 400 N and torque to 20 Nm in an indestructible manner. Load/displacement curve data were analyzed for slope and axial and angular displacements. Results For larger diameter rings (180 mm, for axial stiffness there was no statistically significant difference between the transverse wires (4 wires with 2 rings and the half pins (2 pins with 1 ring (p > 0.05. For 155 mm internal diameter rings, half pins provided statistically higher axial stiffness than transverse wires (p = 0.036. The half pins show significantly more torsion stiffness in both ring diameters (p Conclusion & Clinical Relevance Half pins provide greater stiffness to TSF frames and allow for axial micro motion as well. This work provides a rationale for clinical decision making about the use of tensioned transverse wires in comparison to half pins in construction of a TSF frame

  4. Domain wall pinning by magnetic inhomogeneities in Sm(CoNi) sub 2. 5

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X.; Gaunt, P. (Department of Physics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada (CA))


    Domain wall (thin 180{degree} wall) pinning by pinning sites of atomic size is studied by a new model which is based on the argument that the temperature dependence of the coercivity originates from both thermal activation of the domain wall and the temperature dependence of the height of the energy barriers. This model successfully describes the temperature dependence of the coercivity of a Sm(CoNi){sub 2.5} ferromagnet.

  5. Vortex pinning by the point potential in topological superconductors: A scheme for braiding Majorana bound states (United States)

    Wu, Hai-Dan; Zhou, Tao


    We propose theoretically an effective scheme for braiding Majorana bound states by manipulating the point potential. The vortex pinning effect is carefully elucidated. This effect can be used to control the vortices and Majorana bound states in topological superconductors. The exchange of two vortices induced by moving the potentials is simulated numerically. The zero-energy state in the vortex core is robust with respect to the strength of the potential. The Majorana bound states in a pinned vortex are identified numerically.

  6. Analysis of Flux Pinning in YBa2Cu3O7-δ Films by Nanoparticle-Modified Substrate Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga [ORNL; Paranthaman, Mariappan Parans [ORNL; Leonard, Keith J [ORNL; Kang, Sukill [ORNL; Martin, Patrick M [ORNL; Heatherly Jr, Lee [ORNL; Goyal, Amit [ORNL; Ijaduola, Anota O [ORNL; Thompson, James R [ORNL; Christen, David K [ORNL; Meng, R. [University of Houston, Houston; Rusakova, I. [University of Houston, Houston; Chu, C. W. [University of Houston, Houston


    Enhanced in-field critical current density Jc has been achieved in YBa2Cu3O7-o (YBCO) films grown on single crystal and biaxially textured metal substrate surfaces that were pretreated with second-phase nanoscale MgO and BaZrO3 particles. Nanoparticles were applied using wet chemical solution-based approaches. Results obtained in this study are compared with our previous investigations on surface modified substrates with sputter processed Ir nanoparticles. Cross-sectional TEM analysis and details of the field-orientation dependence of Jc are found to be similar for both sputtered and solution processed nanoparticle species. Present results show a more uniform dependence of Jc over all orientations of magnetic field, along with improved irreversibility behavior. Irrespective of the decoration technique, scaling behavior of the normalized volume pinning force density, Fp, demonstrates the similarity of pinning mechanisms for these YBCO films deposited on artificially modified substrates.

  7. Weak Solution and Weakly Uniformly Bounded Solution of Impulsive Heat Equations Containing “Maximum” Temperature


    Oyelami, Benjamin Oyediran


    In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.

  8. Weak Solution and Weakly Uniformly Bounded Solution of Impulsive Heat Equations Containing “Maximum” Temperature

    Directory of Open Access Journals (Sweden)

    Oyelami, Benjamin Oyediran


    Full Text Available In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.

  9. Doping dependence of the vortex dynamics in single-crystal superconducting NaFe{}_{1-x}Co x As (United States)

    Ahmad, D.; Choi, W. J.; Seo, Y. I.; Jung, S.-G.; Kim, Y. C.; Salem-Sugui, S., Jr.; Park, T.; Kwon, Y. S.


    We investigate the doping dependence of flux pinning in superconducting NaFe{}1-xCo x As (x = 0.01, 0.03, 0.05 and 0.07) single crystals grown by the Bridgman method. The electronic specific heat displays a pronounced anomaly in a sample series at superconducting transition temperature, which hardly shows any residual part at low temperature. We found that Co doping plays an important role in signifying the secondary peak in the magnetic hysteresis of optimally doped (x = 0.03) and heavily doped (x = 0.05, 0.07) crystals. Furthermore, the dependence of the relaxation rate S = ∣d ln M/d ln t∣ on magnetic field and temperature exhibits a decreasing trend within a certain range corresponding to the secondary peak effect in the optimally and heavily doped samples. The magnetic relaxation rate combined with the Maley analysis of the current-dependent creep energy shows a single-vortex pinning in the lightly doped sample dominant at low applied fields, and plastic pinning at high applied fields, without showing a secondary peak. However, in the optimally and heavily doped samples, the magnetic relaxation rate and U(J) isothermal analysis show that the collective pinning that dominates below H peak crosses over to plastic pinning for fields above H peak.

  10. History effects and pinning regimes in solid vortex matter


    Valenzuela, Sergio O.; Bekeris, Victoria


    We propose a phenomenological model that accounts for the history effects observed in ac susceptibility measurements in YBa2Cu3O7 single crystals [Phys. Rev. Lett. 84, 4200 (2000) and Phys. Rev. Lett. 86, 504 (2001)]. Central to the model is the assumption that the penetrating ac magnetic field modifies the vortex lattice mobility, trapping different robust dynamical states in different regions of the sample. We discuss in detail on the response of the superconductor to an ac magnetic field w...

  11. Examination the Torsion Properties of pin-to-plate LAMP Joint (United States)

    Markovits, Tamás; Bauernhuber, Andor; Takács, János

    Laser assisted metal plastic (LAMP) joining is a promising new joining technology. In the course of this study, not the mostly examined overlapped sheet to sheet, but the pin-to-plate geometry is investigated. This geometry maybe useful for supporting industrial application of the method because it can utilize the differences in material properties of the joining partners effectively. However, based on previous research, expanded investigation of the pin to plate geometry is needed. Accordingly, the authors applied different metal pin geometries and laser parameters, like different laser spot diameters, laser pulse powers, laser pulse durations, and different metal pin geometries in micro and macro range as well by using pulse mode Nd:YAG laser beam to create transmission laser joining. The material and state of the metal pin (unalloyed steel) and the plastic sheet (PMMA) was investigated as well. In this research the torsion properties of the pin to plate joints were also investigated in order to determine the basic effects of laser technology to the maximal torques on this type of penetrated joints.

  12. Magnetic nanoparticles in MgB{sub 2}: Vortex pinning, pair breaking and connectivity

    Energy Technology Data Exchange (ETDEWEB)

    Babić, Emil [Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, HR-10000 Zagreb (Croatia); Novosel, Nikolina, E-mail: [Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, HR-10000 Zagreb (Croatia); Pajić, Damir; Galić, Stipe; Zadro, Krešo [Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, HR-10000 Zagreb (Croatia); Drobac, Đuro [Institute of Physics, Bijenička c. 46, HR-10000 Zagreb (Croatia)


    The results indicating magnetic flux pinning in MgB{sub 2} wires doped with three types of magnetic nanoparticles (MNP) are reported. The magnetic state of MNPs, both as-prepared and inside the MgB{sub 2} core, was determined with magnetization and ac susceptibility measurements. The competition between detrimental influence of doping (reduced connectivity, pair breaking) and enhanced flux pinning leads to deterioration of electromagnetic properties of doped wires at high MNP content, whereas light doping causes an enhancement of critical current density, J{sub c}, and/or irreversibility field, B{sub irr}, for all our MNPs. For Ni and dextrin coated NiFe{sub 2}O{sub 4} MNPs the enhancement of J{sub c} was comparable to that achieved with the best nonmagnetic dopands. Detailed analysis indicates the contribution of magnetic flux pinning including the matching effects in flux pinning on MNPs. - Highlights: • Rigorous study of the effects of magnetic particles on superconductivity in MgB2 wires. • Detailed characterisation of magnetic state of nanoparticles embedded in MgB2 matrix. • Matching effects in pinning of vortices on magnetic nanoparticles • Consistent indications of possible contribution of magnetic pinning of vortices.

  13. Materials design for artificial pinning centres in superconductor PLD coated conductors (United States)

    Feighan, J. P. F.; Kursumovic, A.; MacManus-Driscoll, J. L.


    To date the strategy for inducing pinning in REBa2Cu3O7‑x (REBCO where RE = rare-earth) coated conductors has largely been empirical. Hence, we are not yet at a point where we can dial-in the compositions and process parameters to optimise pinning for particular applications having specific temperature, field, and field angle requirements. In this review, we cover the critical materials science aspects which enable the understanding, design and engineering of desired pinning centre morphologies. Our main emphasis is on in in situ epitaxial growth of REBCO films by vapour deposition. We review the optimal pinning centre morphologies which have been determined to be effective for different operation regimes. We also highlight how the interplay of thermodynamics (including epitaxial effects), film-particle interfacial strain, and kinetics determine pinning morphologies. Finally, we also briefly cover pinning in rapid ex situ, liquid assisted growth which is likely to be a necessary universal approach for applications where low cost is critical.

  14. Nanoscale strain-induced pair suppression as a vortex-pinning mechanism in high- temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Llordes, Anna [ICMAB, Barcelona, Spain; Palau, A. [ICMAB, Barcelona, Spain; Gazquez, J. [Oak Ridge National Laboratory (ORNL); Coll, M. [ICMAB, Barcelona, Spain; Vlad, R. [ICMAB, Barcelona, Spain; Pomar, A. [ICMAB, Barcelona, Spain; Arbiol, Jordi [ICMAB, Barcelona, Spain; Guzman, Roger [ICMAB, Barcelona, Spain; Ye, S. [ICMAB, Barcelona, Spain; Rouco, V [ICMAB, Barcelona, Spain; Sandiumenge, Felip [ICMAB, Barcelona, Spain; Ricart, Susagna [ICMAB, Barcelona, Spain; Puig, Teresa [ICMAB, Barcelona, Spain; Varela del Arco, Maria [ORNL; Chataigner, D. [CRISMAT, Caen, France; Vanacken, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Gutierrez, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Moschalkov, V. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Deutscher, G. [Tel Aviv University; Magen Dominguez, Cesar [ORNL; Obradors, Xavier [ICMAB, Barcelona, Spain


    Boosting large-scale superconductor applications require nanostructured conductors with artificial pinning centres immobilizing quantized vortices at high temperature and magnetic fields. Here we demonstrate a highly effective mechanism of artificial pinning centers in solution-derived high-temperature superconductor nanocomposites through generation of nanostrained regions where Cooper pair formation is suppressed. The nanostrained regions identified from transmission electron microscopy devise a very high concentration of partial dislocations associated with intergrowths generated between the randomly oriented nanodots and the epitaxial YBa{sub 2}Cu{sub 3}O{sub 7} matrix. Consequently, an outstanding vortex-pinning enhancement correlated to the nanostrain is demonstrated for four types of randomly oriented nanodot, and a unique evolution towards an isotropic vortex-pinning behaviour, even in the effective anisotropy, is achieved as the nanostrain turns isotropic. We suggest a new vortex-pinning mechanism based on the bond-contraction pairing model, where pair formation is quenched under tensile strain, forming new and effective core-pinning regions.

  15. Experimental and numerical study of Bondura® 6.6 PIN joints (United States)

    Berkani, I.; Karlsen, Ø.; Lemu, H. G.


    Pin joints are widely used in heavy-duty machinery such as aircrafts, cranes and offshore drilling equipment to transfer multi-dimensional shear forces. Their strength and service life depend on the clamping force in the contact region that is provided by interference fits. Though the interference fits provide full contact at the pin-hole interface under pretension loads, the contact interface reduces when the pin is subjected to an external load and hence a smaller contact surface leads to dramatic increase of the contact stress. The PIN joint of Bondura® Technology, investigated in this study, is an innovative solution intended to reduce the slack at the contact surface of the pin joint of heavy-duty machinery by using tapered sleeves on each end of the PIN. The study is aimed to better understand the contact pressure build-up and stress distribution in the supporting contact surface under pre-loading of the joint and the influence of temperature difference between part assembly and operation conditions. Numerical simulation using finite element method and diverse experimental tests were conducted. The numerical simulation and the test results, particularly the tests conducted with lubricated joints, show good conformance.

  16. Ultrasound-guided Percutaneous Medial Pinning of Pediatric Supracondylar Humeral Fractures to Avoid Ulnar Nerve Injury.

    Directory of Open Access Journals (Sweden)

    Francisco Soldado


    Full Text Available Background:  Medial pinning is one of the most controversial aspects of the surgical treatment of supracondylar fractures (SHF owing to the risk of ulnar nerve injury.  Aim: To evaluate the safety and usefulness of medial pinning for SHF using ultrasound imaging for ulnar nerve visualization.   Methods: Fifteen children, with a mean age of 60 months, with displaced SHF were treated with a crossed-pinning configuration after fracture reduction. Intraoperative ultrasound was used to guide medial pin insertion to avoid ulnar nerve injury. Results:  Cubital tunnel anatomy was easily identified in all children. All children showed a subluxating ulnar nerve that required elbow extension to about 90º before medial pin insertion. None suffered ulnar nerve dysfunction after using the referred technique. Conclusions:  Although technically demanding, ultrasound may be a valuable adjuvant to avoid ulnar nerve injury while performing a medial pinning in pediatric SHF.

  17. SCFTIR1/AFB-auxin signalling regulates PIN vacuolar trafficking and auxin fluxes during root gravitropism (United States)

    Baster, Paweł; Robert, Stéphanie; Kleine-Vehn, Jürgen; Vanneste, Steffen; Kania, Urszula; Grunewald, Wim; De Rybel, Bert; Beeckman, Tom; Friml, Jiří


    The distribution of the phytohormone auxin regulates many aspects of plant development including growth response to gravity. Gravitropic root curvature involves coordinated and asymmetric cell elongation between the lower and upper side of the root, mediated by differential cellular auxin levels. The asymmetry in the auxin distribution is established and maintained by a spatio-temporal regulation of the PIN-FORMED (PIN) auxin transporter activity. We provide novel insights into the complex regulation of PIN abundance and activity during root gravitropism. We show that PIN2 turnover is differentially regulated on the upper and lower side of gravistimulated roots by distinct but partially overlapping auxin feedback mechanisms. In addition to regulating transcription and clathrin-mediated internalization, auxin also controls PIN abundance at the plasma membrane by promoting their vacuolar targeting and degradation. This effect of elevated auxin levels requires the activity of SKP-Cullin-F-boxTIR1/AFB (SCFTIR1/AFB)-dependent pathway. Importantly, also suboptimal auxin levels mediate PIN degradation utilizing the same signalling pathway. These feedback mechanisms are functionally important during gravitropic response and ensure fine-tuning of auxin fluxes for maintaining as well as terminating asymmetric growth. PMID:23211744

  18. An analytical model of heat generation for eccentric cylindrical pin in friction stir welding

    Directory of Open Access Journals (Sweden)

    Ahmed Ramadan Shaaban Essa


    Full Text Available An analytical model for heat generation for eccentric cylindrical pin in friction stir welding was developed that utilizes a new factor based on the tool pin eccentricity. The proposed analytical expression is a modification of previous analytical models from the literature, which is verified and well matches with the model developed by previous researchers. Results of plunge force and peak temperature were used to validate the current proposed model. The cylindrical tool pin with eccentricities of 0, 0.2, and 0.8 mm were used to weld two types of aluminum alloys; a low deformation resistant AA1050-H12, and a relatively high deformation resistant AA5754-H24 alloy. The FSW was performed at constant tool rotation speed of 600 rpm and different welding speeds of 100, 300, and 500 mm/min. Experimental results implied that less temperature is generated using eccentric cylindrical pin than cylindrical pin without eccentricity under the given set of FSW process conditions. Furthermore, numerical simulation results show that increasing the pin eccentricity leads to decrease in peak temperature.

  19. Effects of Endwall Fillet and Bulb on the Temperature Uniformity of Pin-Fined Microchannel

    Directory of Open Access Journals (Sweden)

    Zhiliang Pan


    Full Text Available Endwall fillet and bulb structures are proposed in this research to improve the temperature uniformity of pin-fined microchannels. The periodical laminar flow and heat transfer performances are investigated under different Reynolds numbers and radius of fillet and bulb. The results show that at a low Reynolds number, both the fillet and the bulb structures strengthen the span-wise and the normal secondary flow in the channel, eliminate the high temperature area in the pin-fin, improve the heat transfer performance of the rear of the cylinder, and enhance the thermal uniformity of the pin-fin surface and the outside wall. Compared to traditional pin-fined microchannels, the flow resistance coefficient f of the pin-fined microchannels with fillet, as well as a bulb with a 2 μm or 5 μm radius, does not increase significantly, while, f of the pin-fined microchannels with a 10 μm or 15 μm bulb increases notably. Moreover, Nu has a maximum increase of 16.93% for those with fillet and 20.65% for those with bulb, and the synthetic thermal performance coefficient TP increases by 16.22% at most for those with fillet and 15.67% at most for those with bulb. At last, as the Reynolds number increases, heat transfer improvement of the fillet and bulb decreases.

  20. Mechanical evaluation of pin and tension-band wire factors in an olecranon osteotomy model. (United States)

    Neat, Benjamin C; Kowaleski, Michael P; Litsky, Alan S; Boudrieau, Randy J


    To evaluate the effect of altering pin and wire diameter, wire position and configuration, and osteotomy angle on applied load and absorbed strain energy in a pin and tension-band wire (PTBW) fixation model. In vitro mechanical study. Delrin models (n=96). PTBW was applied to Delrin olecranon osteotomy models. A control configuration was defined and then altered, 1 variable (wire diameter, pin diameter, wire-hole position, wire configuration, osteotomy angle) at a time, to create 11 test configurations. Tensile force was applied and displacement at the caudal aspect of the osteotomy was measured. Fixation strength, in terms of tensile load and strain energy, was compared between control and each test configuration at 4 osteotomy displacements. Models with larger wire, pins, or combined figure-of-eight/lateral wires were stronger than control, whereas those with smaller wire, pins, or a solitary lateral wire were weaker. The superior strength of the larger wire was apparent for all assessed osteotomy displacement. PTBW fixation strength increases as implant diameter is increased, with wire diameter having greatest effect. Lateral wire configuration is weaker than figure-of-eight, but can be added to figure-of-eight configuration to increase strength. Wire-hole position and osteotomy angle have little effect on PTBW strength. Wire diameter is the key determinant of PTBW strength, whereas pin diameter is somewhat less critical. Wire passage through an additional hole proximally provides equivalent strength and may avoid soft-tissue entrapment and subsequent loosening.

  1. Network approach to the pinning control of drift-wave turbulence. (United States)

    Liu, Panpan; Deng, Zhigang; Yang, Lei; Zhan, Meng; Wang, Xingang


    Network of coupled oscillators has long been employed as an important approach to explore the complicated dynamics in spatially extended systems. Here we show how this approach can be used to the analysis of turbulence pinning control. Specifically, by use of a model of two-dimensional drift-wave plasma turbulence, we investigate how the performance of the turbulence control is influenced by the spatial distribution of the pinning strength. It is found that the dynamics of pinned turbulence can be well captured by a simple model of networked modes, based on which the dependence of the control performance on the pinning distribution can be analytically obtained. In particular, the model predicts that as the distribution of the pinning strength becomes more nonuniform, the performance of turbulence control will be gradually decreased. This theoretical prediction is in good agreement with the results of numerical simulations, including the sinusoidal and localized pinning distributions. Our studies provide a new viewpoint to the mechanism of mode couplings in drift-wave turbulence, as well as be constructive to the design of new schemes for controlling turbulence in realistic systems.

  2. Quadriceps weakness and osteoarthritis of the knee. (United States)

    Slemenda, C; Brandt, K D; Heilman, D K; Mazzuca, S; Braunstein, E M; Katz, B P; Wolinsky, F D


    The quadriceps weakness commonly associated with osteoarthritis of the knee is widely believed to result from disuse atrophy secondary to pain in the involved joint. However, quadriceps weakness may be an etiologic factor in the development of osteoarthritis. To explore the relation between lower-extremity weakness and osteoarthritis of the knee. Cross-sectional prevalence study. Population-based, with recruitment by random-digit dialing. 462 volunteers 65 years of age or older. Radiographs of the knee were graded for the presence of osteoarthritis. Knee pain and function were assessed with the Western Ontario and McMaster Universities Arthritis Index, the strength of leg flexors and extensors was assessed with isokinetic dynamometry, and lower-extremity lean tissue mass was assessed with dual-energy x-ray absorptiometry. Among participants with osteoarthritis, quadriceps weakness, but not hamstring weakness, was common. The ratio of extensor strength to body weight was approximately 20% lower in those with than in those without radiographic osteoarthritis. Notably, among women with tibiofemoral osteoarthritis, extensor weakness was present in the absence of knee pain and was seen in participants with normal lower-extremity lean mass (extensor strength, 30.1 lb-ft for those with osteoarthritis and 34.8 lb-ft for those without osteoarthritis; P osteoarthritis of the knee (odds ratio for prevalence of osteoarthritis per 10 lb-ft loss of strength, 0.8 [95% CI, 0.71 to 0.90] for radiographic osteoarthritis and 0.71 [CI, 0.51 to 0.87] for symptomatic osteoarthritis). Quadriceps weakness may be present in patients who have osteoarthritis but do not have knee pain or muscle atrophy; this suggests that the weakness may be due to muscle dysfunction. The data are consistent with the possibility that quadriceps weakness is a primary risk factor for knee pain, disability, and progression of joint damage in persons with osteoarthritis of the knee.

  3. Characterization of the passivation processes for PIN structures

    Energy Technology Data Exchange (ETDEWEB)

    Avila Garcia, Alejandro; Reyes Barranca, Mario Alfredo [Instituto Politecnico Nacional, Mexico, D.F (Mexico); Zarate Corona, Oscar [Universidad Autonoma de Puebla, Puebla (Mexico)


    Result on the evaluation of PIN structures made on crystalline silicon, processed in our laboratory, which underwent several gettering treatments are reported. Structures were evaluated through the measurement of lifetime {tau} and I-V characteristic. Also, deep levels due to defects were characterized; the activation energy (E{sub c} -E{sub t}), capture cross section {sigma} and relative concentration (N{sub t} / N{sub d}) were obtained. Techniques used in the characterization were Output Circuit Voltage Decay (OCVD), Current-Voltage measurements (I-V) and Deep Level Transient Spectroscopy (DLTS), respectively. These measurements show variations in the parameters, as a result of the gettering techniques applied. The best results were achieved for two types of samples: the first having high phosphorus concentration, no backside damage and annealed at 850 Celsius degrees without HCI atmosphere; the second having low phosphorus concentration, no backside damage and annealed at 850 Celsius degrees without HCI atmosphere. For these samples, the minority carrier lifetime was near 3{upsilon}s, the I-V characteristics imply that conductivity modulation takes place within the intrinsic region even for low voltages, as in commercial diodes. Two defects were observed to remain after the gettering processes: one is related to the phosphorus-vacant pair and the other to the divacancy. Concentrations could be decreased from {approx}4 x 10{sup 1}1cm{sup -3} down to 3 x 10{sup -9} cm{sup -3} for the first and down to 2 x 10{sup 1}0 cm{sup -3} for the second one. [Spanish] Se reportan resultados de la evaluacion de estructuras PIN en silicio procesadas en nuestro laboratorio, las cuales fueron sometidas a diversos tratamientos de gettering. Las estructuras fueron evaluadas a traves de la medicion de tiempo de vida {tau} y la caracteristica I-V. Se caracterizaron tambien los defectos que introducen niveles profundos en la region activa del dispositivo, obteniendo energia de

  4. Strong versus Weak Ties in Migration


    Giulietti, Corrado; Wahba, Jackline; Zenou, Yves


    This paper studies the role of strong versus weak ties in the rural-to-urban migration decision in China. We first develop a network model that puts forward the different roles of weak and strong ties in helping workers to migrate to the city. We then use a unique longitudinal data that allows us to test our model by focusing on first-time migration. Strong ties are measured by the closest family contact (excluding household members) while weak ties are determined by the fraction of migrants ...

  5. Quantum correlation cost of the weak measurement

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jun; Wu, Shao-xiong; Yu, Chang-shui, E-mail:


    Quantum correlation cost (QCC) characterizing how much quantum correlation is used in a weak-measurement process is presented based on the trace norm. It is shown that the QCC is related to the trace-norm-based quantum discord (TQD) by only a factor that is determined by the strength of the weak measurement, so it only catches partial quantumness of a quantum system compared with the TQD. We also find that the residual quantumness can be ‘extracted’ not only by the further von Neumann measurement, but also by a sequence of infinitesimal weak measurements. As an example, we demonstrate our outcomes by the Bell-diagonal state.

  6. Curved faces in polymer crystals with asymmetrically spreading growth patches (United States)

    Ungar, Goran


    Polymer crystals often have curved faces. Understanding such morphology is of major interest since it allows distinction between fundamentally different theories of polymer crystallization. E.g. Sadler's ``roughness-pinning'' theory assumes that the curvature is a result of roughening transition on lateral faces. It has since been shown by Mansfield that the curvature can be explained quantitatively, essentially within the Lauritzen-Hoffman nucleation theory. However, the step propagation rates v implied in their treatment are substantially lower than predicted by the LH theory. The retardation appears to be due to the ``self-poisoning'' or ``pinning'' effect of incorrect chain attachment, effectively demonstrated by the extreme cases of growth rate minima in long-chain monodisperse n-alkanes. Recently crystals of poly(vinylidene fluoride) and alkanes C162H326 and C198H398 have been found with habits that can be best described as bounded by curved 110 faces. The interesting feature is the asymmetry of the curvature: while the faces are curved at one end, they are straight at the other. We carried out mathematical analysis of the curvature, generalizing the Mansfield model. We suggest that such asymmetric curvature arises from the propagation rates to the left, vl, and to the right, vr, being different because of the lack of mirror bisecting planes such as (110). By solving appropriate equations with moving boundaries, we obtained the shape of the growth front y(x,t). Calculated crystal habits gave excellent fits to the observed growth shapes of a-axis lenticular crystals of long alkanes and PVDF, as well as of single crystals of PEO. This explains some hitherto poorly understood morphologies and, in principle, allows independent measurements of step initiation and propagation rates in all polymers.

  7. Oil diffusivity through fat crystal networks. (United States)

    Green, Nicole L; Rousseau, Dérick


    Oil migration in chocolate and chocolate-based confections leads to undesirable visual and textural changes. Establishing ways to slow this unavoidable process would increase shelf life and reduce consumer rejection. Diffusion is most often credited as the main pathway by which oil migration occurs. Here, we use fluorescence recovery after photobleaching (FRAP) to explore the diffusion coefficients of vegetable and mineral oil through fat crystal networks at different solid fat contents (SFC). Differences in compatibility between the fat and oil lead to unique primary crystal clusters, yet those variations do not affect diffusion at low SFCs. Trends deviate at higher SFCs, which we ascribe to the influence of the differing crystal cluster structures. We relate our results to the strong and weak-link rheological regimes of fat crystal networks. Finally, we connect the results to relationships developed for polymer gel systems.

  8. Low-noise InGaAs balanced p-i-n photoreceiver for space based remote sensing applications at 2 micron wavelength (United States)

    Joshi, Abhay; Becker, Don; Datta, Shubhashish


    Greenhouse gases, such as carbon dioxide, carbon monoxide, and methane, can be remotely monitored through optical spectroscopy at ~2 micron wavelength. Space based LIDAR sensors have become increasingly effective for greenhouse gas detection to study global warming. The functionality of these LIDAR sensors can be enhanced to track global wind patterns and to monitor polar ice caps. Such space based applications require sensors with very low sensitivity in order to detect weak backscattered signals from an altitude of ~1000km. Coherent detection allows shot noise limited operation at such optical power levels. In this context, p-i-n photoreceivers are of specific interest due to their ability to handle large optical power, thereby enabling high coherent gain. Balanced detection further improves the system performance by cancelling common mode noise, such as laser relative intensity noise (RIN). We demonstrate a low-noise InGaAs balanced p-i-n photoreceiver at 2μm wavelength. The photoreceiver is comprised of a matched pair of p-i-n photodiodes having a responsivity of 1.34A/W that is coupled to transimpedance amplifier (TIA) having an RF gain of 24dB (transimpedance = 800Ω) and input equivalent noise of 19pA/√Hz at 300K. The photoreceiver demonstrates a 3dB bandwidth of 200MHz. Such bandwidth is suitable for LIDAR sensors having 20 to 30m resolution. The photoreceiver exhibits a common mode rejection ratio of 30dB and optical power handling of 3dBm per photodiode.

  9. Intrinsic dynamics of weakly and strongly confined excitons in nonpolar nitride-based heterostructures


    Corfdir, Pierre; Levrat, Jacques; Dussaigne, Amélie; Lefebvre, Pierre; Teisseyre, Henryk; Grzegory, Izabella; Suski, Tadeusz; Ganière, Jean-Daniel; Grandjean, Nicolas; Deveaud-Plédran, Benoît


    Both weakly and strongly confined excitons are studied by time-resolved photoluminescence in a nonpolar nitride-based heterostructure grown by molecular beam epitaxy on the a-facet of a bulk GaN crystal, with an ultralow dislocation density of 2 × 105 cm-2. Strong confinement is obtained in a 4 nm thick Al0.06Ga0.94N/GaN quantum well (QW), whereas weakly confined exciton-polaritons are observed in a 200 nm thick GaN epilayer. Thanks to the low dislocation density, the effective lifetime of st...

  10. Current problems in the weak interactions

    Energy Technology Data Exchange (ETDEWEB)

    Pais, A


    Some reasons are discussed showing why the recent SU(2) x U(1) gauge theory of weak and electromagnetic interactions is not a complete theory of these interactions, Lepton theory, charm, and the CP problem are considered. 60 references. (JFP)

  11. Measurement of X-ray spectra by PIN photodiode: comparative study; Espectros de raios-X medidos com fotodiodos Pin : estudo comparativo

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paulo R.; Furquim, Tania A.C. [Sao Paulo Univ., SP (Brazil). Inst. de Eletrotecnica e Energia; Terini, Ricardo A. [Pontificia Univ. Catolica de Sao Paulo, SP (Brazil); Herdade, Silvio B. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica


    Two different approaches for the evaluation of diagnostic X-ray spectra are presented : one based on a semiempirical model and other based on measurements using a silicon PIN photodiode. Measured and calculated values using typical kVp and filter combinations are compared 7 refs., 1 fig. 1 tab.

  12. The telomerase inhibitor PinX1 is a major haploinsufficient tumor suppressor essential for chromosome stability in mice. (United States)

    Zhou, Xiao Zhen; Huang, Pengyu; Shi, Rong; Lee, Tae Ho; Lu, Gina; Zhang, Zhihong; Bronson, Roderick; Lu, Kun Ping


    Telomerase is activated in most human cancers and is critical for cancer cell growth. However, little is known about the significance of telomerase activation in chromosome instability and cancer initiation. The gene encoding the potent endogenous telomerase inhibitor PinX1 (PIN2/TRF1-interacting, telomerase inhibitor 1) is located at human chromosome 8p23, a region frequently exhibiting heterozygosity in many common human cancers, but the function or functions of PinX1 in development and tumorigenesis are unknown. Here we have shown that PinX1 is a haploinsufficient tumor suppressor essential for chromosome stability in mice. We found that PinX1 expression was reduced in most human breast cancer tissues and cell lines. Furthermore, PinX1 heterozygosity and PinX1 knockdown in mouse embryonic fibroblasts activated telomerase and led to concomitant telomerase-dependent chromosomal instability. Moreover, while PinX1-null mice were embryonic lethal, most PinX1+/- mice spontaneously developed malignant tumors with evidence of chromosome instability. Notably, most PinX1 mutant tumors were carcinomas and shared tissues of origin with human cancer types linked to 8p23. PinX1 knockout also shifted the tumor spectrum of p53 mutant mice from lymphoma toward epithelial carcinomas. Thus, PinX1 is a major haploinsufficient tumor suppressor essential for maintaining telomerase activity and chromosome stability. These findings uncover what we believe to be a novel role for PinX1 and telomerase in chromosome instability and cancer initiation and suggest that telomerase inhibition may be potentially used to treat cancers that overexpress telomerase.

  13. Targeting Pin1 by inhibitor API-1 regulates microRNA biogenesis and suppresses hepatocellular carcinoma development. (United States)

    Pu, Wenchen; Li, Jiao; Zheng, Yuanyuan; Shen, Xianyan; Fan, Xin; Zhou, Jian-Kang; He, Juan; Deng, Yulan; Liu, Xuesha; Wang, Chun; Yang, Shengyong; Chen, Qiang; Liu, Lunxu; Zhang, Guolin; Wei, Yu-Quan; Peng, Yong


    Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide, but there are few effective treatments. Aberrant microRNA (miRNA) biogenesis is correlated with HCC development. We previously demonstrated that prolyl isomerase Pin1 participates in miRNA biogenesis and is a potential HCC treatment target. However, how Pin1 modulates miRNA biogenesis remains obscure. Here, we present in vivo evidence that Pin1 overexpression is directly linked to the development of HCC. Administration with Pin1 inhibitor API-1, a novel and specific small molecule targeting Pin1 PPIase domain and inhibiting Pin1 cis-trans isomerizing activity, suppresses in vitro cell proliferation and migration of HCC cells. But API-1-induced Pin1 inhibition is insensitive to HCC cells with low Pin1 expression and/or low XPO5 phosphorylation. Mechanistically, Pin1 recognizes and isomerizes the phosphorylated Serine-Proline (pS-P) motif of pXPO5 and passivates pXPO5. Pin1 inhibition by API-1 maintains the active conformation of pXPO5, restores XPO5-driven precursor miRNA nuclear-to-cytoplasm export, activating anticancer miRNA biogenesis, and leading to both in vitro HCC suppression and HCC suppression in xenograft mice. Experimental evidence suggests Pin1 inhibition by API-1 upregulates miRNA biogenesis via retaining active XPO5 conformation and suppresses HCC development, revealing the mechanism of Pin1-mediated miRNA biogenesis and unequivocally supports API-1 as a novel drug candidate for HCC therapy, especially for Pin1-overexpressing, ERK-activated HCC. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

  14. Crystallization process (United States)

    Adler, Robert J.; Brown, William R.; Auyang, Lun; Liu, Yin-Chang; Cook, W. Jeffrey


    An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

  15. Self-assembling nano-diameter needlelike pinning centers in YBCO, utilizing a foreign element dopant

    Energy Technology Data Exchange (ETDEWEB)

    Sawh, Ravi-Persad [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Weinstein, Roy [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Obot, Victor [Department of Mathematics, Texas Southern University, 3100 Cleburne St, Houston Texas 77004-4597 (United States); Parks, Drew [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Gandini, Alberto [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Skorpenske, Harley [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States)


    Although pinning centers created by irradiation presently produce the highest J{sub c}, it is probable that ultimately these will be emulated by chemical pinning centers. The best pinning centers produced by irradiation nevertheless provide guidelines for desirable morphology of chemical pinning structures. The highest J{sub c} produced earlier in textured HTS was obtained using isotropic high-energy ions produced by fission of {sup 235}U. This so-called U/n process produces pinning centers of diameter {<=} 4.5 nm, with an effective length of {approx}2.7 {mu}m. Maximum J{sub c} occurs for pinning center density of {approx}10{sup 10} cm{sup -3}. We use this as a model for desired chemical pinning centers. Our approach to introducing chemical pinning centers has been to produce precipitates within the HTS containing elements not native to the HTS, and to seek needlelike (columnar) deposits of small diameter. We report here on the formation of needlelike or columnar deposits in textured Y123 containing a dopant foreign to Y123. It serves as a demonstration that self-assembling nanometer diameter columns utilizing a dopant foreign to the HTS system are a feasible goal. These deposits, however, do not fully meet the ultimate requirements of pinning centers because the desired deposits should be smaller. The self-assembling columns formed contain titanium, are {approx}500 nm in diameter, and up to 10 {mu}m long. The size and morphology of the deposits vary with the mass of admixed Ti dopant. J{sub c} is decreased for small dopant mass. At larger dopant masses needlelike precipitates form, and J{sub c} increases again. A small range of mass of admixed Ti exists in which J{sub c} is enhanced by pinning. In the range of admixed Ti mass studied in these experiments there is a negligible effect on T{sub c}. Magnetization studies of J{sub c} are also reported.

  16. Regularity of Tor for weakly stable ideals

    Directory of Open Access Journals (Sweden)

    Katie Ansaldi


    Full Text Available It is proved that if I and J are weakly stable ideals in a polynomial ring R = k[x_1, . . ., x_n], with k a field, then the regularity of Tor^R_i (R/I, R/J has the expected upper bound. We also give a bound for the regularity of Ext^i_R (R/I, R for I a weakly stable ideal.

  17. The regularization of Old English weak verbs


    Marta Tío Sáenz


    [EN] This article deals with the regularization of non-standard spellings of the verbal forms extracted from a corpus. It addresses the question of what the limits of regularization are when lemmatizing Old English weak verbs. The purpose of such regularization, also known as normalization, is to carry out lexicological analysis or lexicographical work. The analysis concentrates on weak verbs from the second class and draws on the lexical database of Old English Nerthus, which has incorporate...

  18. Drift waves in a weakly ionized plasma

    DEFF Research Database (Denmark)

    Popovic, M.; Melchior, H.


    A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated.......A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated....

  19. Muscle weakness causes joint degeneration in rabbits. (United States)

    Rehan Youssef, A; Longino, D; Seerattan, R; Leonard, T; Herzog, W


    The objective of this study was to investigate the effects of botulinum toxin type-A (BTX-A) induced quadriceps weakness on micro-structural changes in knee cartilage of New Zealand White (NZW) rabbits. Fifteen rabbits were divided randomly into an experimental and a sham control group. Each group received a unilateral single quadriceps muscle injection either with saline (sham control; n=4) or BTX-A (experimental; n=11). BTX-A injection produced significant quadriceps muscle weakness (Pmuscle mass (Pknee cartilage, assessed with the Mankin grading system, were the same for the injected and non-injected hind limbs of the experimental group animals. Sham injection had no effect on joint degeneration but all control animals showed some degenerative changes in the knee. Degenerative changes of the retro-patellar cartilage were more severe in the experimental compared to sham control group rabbits (P0.05). Quadriceps muscle weakness caused increased degeneration in the retro-patellar cartilage of NZW rabbits, providing evidence that muscle weakness might be a risk factor for the onset and progression of osteoarthritis (OA). Future work needs to delineate whether muscle weakness directly affects joint degeneration, or if changes in function and movement execution associated with muscle weakness are responsible for the increased rate of OA onset and progression observed here.

  20. Morphological diversity of nitroguanidine crystals with enhanced mechanical performance and thermodynamic stability (United States)

    Luo, Zhilong; Cui, Yingdan; Dong, Weibing; Xu, Qipeng; Zou, Gaoxing; Kang, Chao; Hou, Baohong; Chen, Song; Gong, Junbo


    Nitroguanidine (NQ) is a commonly used explosive, which has been widely used for both civilian and military explosive applications. However, the weak flowability and mechanical performance limit its application. In this work, mechanical performance and thermodynamic stability of NQ crystals were improved by controlling crystal morphologies in the crystallization process. Typical NQ crystals with multiple morphologies and single crystal form were obtained in the presence of additives during the cooling crystallization. The morphology controlled NQ crystals showed higher density, unimodal crystal size distribution and enhanced flowability. The additives showed the inhibitory effect on the nucleation of NQ crystals by in-situ FBRM and PVM determination, and the mechanism was analyzed by means of morphological prediction and molecular simulation. Furthermore, the morphology controlled NQ crystals suggested higher thermodynamic stability according to the calculation of entropy, enthalpy, Gibbs free energy and apparent activation energy on the basis of DSC results.


    Directory of Open Access Journals (Sweden)

    V. D. Petrenko


    Full Text Available Purpose. This article provides: the question of the sustainability of the subgrade on a weak base is considered in the paper. It is proposed to use the method of jet grouting. Investigation of the possibility of a weak base has an effect on the overall deformation of the subgrade; the identification and optimization of the parameters of subgrade based on studies using numerical simulation. Methodology. The theoretical studies of the stress-strain state of the base and subgrade embankment by modeling in the software package LIRA have been conducted to achieve this goal. Findings. After making the necessary calculations perform building fields of a subsidence, borders cramped thickness, bed’s coefficients of Pasternak and Winkler. The diagrams construction of vertical stress performs at any point of load application. Also, using the software system may perform peer review subsidence, rolls railroad tracks in natural and consolidated basis. Originality. For weak soils is the most appropriate nonlinear model of the base with the existing areas of both elastic and limit equilibrium, mixed problem of the theory of elasticity and plasticity. Practical value. By increasing the load on the weak base as a result of the second track construction, adds embankment or increasing axial load when changing the rolling stock process of sedimentation and consolidation may continue again. Therefore, one of the feasible and promising options for the design and reconstruction of embankments on weak bases is to strengthen the bases with the help of jet grouting. With the expansion of the railway infrastructure, increasing speed and weight of the rolling stock is necessary to ensure the stability of the subgrade on weak bases. LIRA software package allows you to perform all the necessary calculations for the selection of a proper way of strengthening weak bases.

  2. Thickness independence of the vortex pinning by columnar defects. (United States)

    Indenbom, Mikhail; van der Beek, Kees; Konczykowski, Marcin


    Direct magneto-optical imaging of the flux penetration into high-Tc superconductors with inclined columnar defects revealed that the vortices slide along the columns easier than they move across them footnote Th. Schuster et al., Phys Rev. B 50, 660 (1955); 51, 16358 (1995); 53, 2257 (1996). For the atomically smooth defects a very high value of the anisotropy might be expected but the observed one was rather moderate. To explain this fact it was supposed that the vortex drift may be controlled by their depinning at the surface with further easy motion of the vortex kinks deep to the crystal, contrary to the common belief of the dominating bulk double kink depinning. We checked the immediate consequences of the supposition: the critical current flowing only in the surface layer and thickness independents of the magnetic hysteresis, by observations of the flux penetration into YBCO crystals with varying thickness irradiated with 6 GeV Pb ions. A surprisingly regular penetration like it would be for a sample with homogeneous thickness has been observed. Additional qualitative experiments to verify this model are in progress.

  3. Weak localization and spin splitting in inversion layers on p -type InAs (United States)

    Schierholz, Christopher; Matsuyama, Toru; Merkt, Ulrich; Meier, Guido


    We report on the magnetoconductivity of quasi-two-dimensional electron systems in inversion layers on p -type InAs single crystals. In low magnetic fields pronounced features of weak localization and antilocalization are observed. They are almost perfectly described by the theory of Iordanskii, Lyanda-Geller, and Pikus. This allows us to determine the spin splitting and the Rashba parameter of the ground electric subband as a function of the electron density.

  4. Biomechanical Comparison of Locking Compression Plate versus Positive Profile Pins and Polymethylmethacrylate for Stabilization of the Canine Lumbar Vertebrae. (United States)

    Sturges, Beverly K; Kapatkin, Amy S; Garcia, Tanya C; Anwer, Cona; Fukuda, Shimpei; Hitchens, Peta L; Wisner, Tristan; Hayashi, Kei; Stover, Susan M


    To compare the stiffness, angular deformation, and mode of failure of lumbar vertebral column constructs stabilized with bilateral pins and polymethylmethacrylate (Pin-PMMA) or with a unilateral (left) locking compression plate (LCP) with monocortical screws. Ex vivo biomechanical, non-randomized. Cadaveric canine thoracolumbar specimens (n=16). Thoracolumbar (T13-L3) vertebral specimens had the L1-L2 vertebral motion unit stabilized with either Pin-PMMA or LCP. Stiffness in flexion, extension, and right and left lateral bending after nondestructive testing were compared between intact (pretreated) specimens and Pin-PMMA, and LCP constructs. The Pin-PMMA and LCP constructs were then tested to failure in flexion and left lateral bending. Both the Pin-PMMA and LCP constructs had reduced range of motion at the stabilized L1-L2 vertebral motion unit compared to intact specimens. The Pin-PMMA constructs had less range of motion for the flexion elastic zone than LCP constructs. The Pin-PMMA constructs were stiffer than intact specimens in flexion, extension, and lateral bending, and stiffer than LCP constructs in flexion and left lateral bending. The Pin-PMMA constructs had less angular deformation at construct yield and lower residual deformation at L1-L2 than LCP constructs after destructive testing to failure in flexion. The Pin-PMMA constructs were stiffer, stronger, and had less deformation at yield than LCP constructs after destructive testing to failure in lateral bending. Most constructs failed distant to the implant and fixation site. Pin-PMMA constructs had greater lumbar vertebral stiffness and reduced ROM than LCP constructs; however, both Pin-PMMA and LCP constructs were stronger than intact specimens. © Copyright 2016 by The American College of Veterinary Surgeons.

  5. Effects of Solder Temperature on Pin Through-Hole during Wave Soldering: Thermal-Fluid Structure Interaction Analysis


    M. S. Abdul Aziz; Abdullah, M. Z.; Khor, C. Y.


    An efficient simulation technique was proposed to examine the thermal-fluid structure interaction in the effects of solder temperature on pin through-hole during wave soldering. This study investigated the capillary flow behavior as well as the displacement, temperature distribution, and von Mises stress of a pin passed through a solder material. A single pin through-hole connector mounted on a printed circuit board (PCB) was simulated using a 3D model solved by FLUENT. The ABAQUS solver was ...

  6. The First Gauge Theory of Weak Interactions and the Prediction of Weak Neutral Currents


    Bludman, S. A.


    The three theoretical and historical components of the Standard Model are the exact chiral gauge theory of weak interactions, electroweak unification, and the Higgs mechanism for spontaneous symmetry breaking. I put into historical perspective my 1958 invention of the first gauge theory of weak interactions, predicting weak neutral currents, and show how the fundamental differences between global and gauge symmetries and between partial flavour and exact gauge symmetries, emerged in the stron...

  7. Geometric phase topology in weak measurement (United States)

    Samlan, C. T.; Viswanathan, Nirmal K.


    The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1–64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a pre-selected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (η) or ellipse orientation (χ) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the η spread in the complementary χ basis results in the appearance of a geometric phase with helical phase topology in the η ‑ χ parameter space. By representing the weak measurement on the Poincaré sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques’ capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.

  8. Consolidated fuel reprocessing program: Criticality experiments with fast test reactor fuel pins in an organic moderator

    Energy Technology Data Exchange (ETDEWEB)

    Bierman, S.R.


    The results obtained in a series of criticality experiments performed as part of a joint program on criticality data development between the United States Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan are presented in this report along with a complete description of the experiments. The experiments involved lattices of Fast Test Reactor (FTR) fuel pins in an organic moderator mixture similar to that used in the solvent extraction stage of fuel reprocessing. The experiments are designed to provide data for direct comparison with previously performed experimental measurements with water moderated lattices of FTR fuel pins. The same lattice arrangements and FTR fuel pin types are used in these organic moderated experimental assemblies as were used in the water moderated experiments. The organic moderator is a mixture of 38 wt % tributylphosphate in a normal paraffin hydrocarbon mixture of C{sub 11}H{sub 24} to C{sub 15}H{sub 32} molecules. Critical sizes of 1054.8, 599.2, 301.8, 199.5 and 165.3 fuel pins were obtained respectively for organic moderated lattices having 0.761 cm, 0.968 cm, 1.242 cm, 1.537 cm and 1.935 cm square lattice pitches as compared to 1046.9, 571.9, 293.9, 199.7 and 165.1 fuel pins for the same lattices water moderated.

  9. Effect of magnetic element ions on collective pinning behaviour in Bi-2223 quadrilateral bars

    Energy Technology Data Exchange (ETDEWEB)

    Adam, M.I. [Department of Electrical and Electronic Engineering, University of Technology Petronas (UTP), 31750 Tronoh, Perak (Malaysia)], E-mail:


    Frequency and ac field dependence of Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}(Ca{sub 1-x}M{sub x}){sub 2}Cu{sub 3}O{sub {delta}} quadrilateral bars with x {<=} 0.02 and M = Pr, Nd, Sm, Gd and Ni, prepared by the conventional reaction method have been measured in the range of low field/frequency ac susceptibility and BSCCO superconducting temperature. The ac loss peak shifts to higher temperature and its summit shows nonlinear change with increasing frequency. Introduction of magnetic ions as defects is found to increase the intergranular critical current J{sub cm} and the flux pinning of Bi(Pb)-2223 system. Application of the power law critical state model suggested that pinning behaviour of specimen could be viewed as hysteretic bulk pinning and/or flux creep. On the other hand, J{sub cm} dependence activation energy is found to obey E{sub a} {proportional_to} J{sup -{mu}} relation, characteristic of the vortex glass/collective creep. Hence, collective pinning behaviour of specimens is discussed in view of the intergranular pinning mechanism.

  10. Partially degradable friction-welded pure iron-stainless steel 316L bone pin. (United States)

    Nasution, A K; Murni, N S; Sing, N B; Idris, M H; Hermawan, H


    This article describes the development of a partially degradable metal bone pin, proposed to minimize the occurrence of bone refracture by avoiding the creation of holes in the bone after pin removal procedure. The pin was made by friction welding and composed of two parts: the degradable part that remains in the bone and the nondegradable part that will be removed as usual. Rods of stainless steel 316L (nondegradable) and pure iron (degradable) were friction welded at the optimum parameters: forging pressure = 33.2 kPa, friction time = 25 s, burn-off length = 15 mm, and heat input = 4.58 J/s. The optimum tensile strength and elongation was registered at 666 MPa and 13%, respectively. A spiral defect formation was identified as the cause for the ductile fracture of the weld joint. A 40-µm wide intermetallic zone was identified along the fusion line having a distinct composition of Cr, Ni, and Mo. The corrosion rate of the pin gradually decreased from the undeformed zone of pure iron to the undeformed zone of stainless steel 316L. All metallurgical zones of the pin showed no toxic effect toward normal human osteoblast cells, confirming the ppb level of released Cr and Ni detected in the cell media were tolerable. © 2014 Wiley Periodicals, Inc.

  11. Efektivitas Penambahan Pin Terhadap Kuat Cabut Tulangan Bambu Apus pada Beton Normal Struktural

    Directory of Open Access Journals (Sweden)

    Yanuar Haryanto


    Full Text Available Bamboo is an alternative material that has the potential to be developed as a replacement for steel bars because bamboo has a tensile strength comparable to steel. However, there are constraints on the properties of the expansion and shrinkage of bamboo, which in its use as reinforcement, bamboo will expand due to the absorption of water in fresh concrete and then will shrink along with the evaporation of water in the process of drying concrete. Shrinkage in a bamboo cause a loss of bonding in bamboo and concrete that may cause a collapse. This paper discusses the effectiveness of the addition of a pin to the pullout strength of apus bamboo reinforcement on the structural normal concrte. The pin that was added is a steel wire that is implanted as a retaining when the shrinkage of bamboo reinforcement occur. The specimen was a concrete cylinder with a height of 20 cm and a diameter of 12 cm, analytical approach taken to equalize the dimensions of the bamboo with a diameter of 6 mm steel reinforcement. Variation of the number of pins used were 0, 2, 3 and 4. The results show that the ratio of the pullout strength of bamboo reinforcement with the addition of 3 pins, to the pullout strength of steel reinforcement is 1.01. The Addition of pin showed a high effectiveness to the pullout strength of apus bamboo reinforcement with a 92.22% infulence.

  12. Plate Fixation versus Percutaneous Pinning for Unstable Metacarpal Fractures: A Meta-analysis. (United States)

    Melamed, Eitan; Joo, LiJin; Lin, Edward; Perretta, Donato; Capo, John T


    Whether percutaneous pinning or plate fixation is more appropriate for metacarpal fractures is still open to debate. Our study purpose was to review the current literature in an attempt to determine the optimal treatment modality for metacarpal fractures on the basis of functional outcomes, radiographic outcome and rates of complications. We selected Pubmed, Cochrane library, EMBASE and the relevant English orthopedic journals and pooled data from eligible trials including four comparative studies and one retrospective review. Overall, the studies contained 222 patients with 231 fractures, 143 treated with pinning and 88 treated with plates and screws. Mean follow up was 7.5 months (4-12 months). Data were analyzed and the fixed effects are assumed for meta-analysis. Patients undergoing pinning for metacarpal fractures have higher motion scores when compared to open reduction and internal fixation with plate and screws. Functional scores, grip strength, radiographic parameters, time to union and complications were found not to be significantly different between the two groups. There is evidence to support the use of pins over ORIF with plates and screws in the treatment of metacarpal fractures. This may have practical advantages, including minimal dissection, easier insertion and availability of the pins. The limitations of this study include the small number of eligible studies, lack of reporting of standard deviation value, and the lack of DASH score assessments at follow up. Further randomized controlled trials that include a larger patient numbers with longer follow up are needed to substantiate the superiority of one fixation method over another.

  13. Improved Bonding of Partially Osteomyelitic Bone to Titanium Pins Owing to Biomimetic Coating of Apatite

    Directory of Open Access Journals (Sweden)

    Hirotaka Mutsuzaki


    Full Text Available Increased fixation strength of the bone-pin interface is important for inhibiting pin loosening after external fixation. In a previous study, an apatite (Ap layer was formed on anodically oxidized titanium (Ti pins by immersing them in an infusion fluid-based supersaturated calcium phosphate solution at 37 °C for 48 h. In the present study, an Ap layer was also successfully formed using a one-step method at 25 °C for 48 h in an infusion fluid-based supersaturated calcium phosphate solution, which is clinically useful due to the immersion temperature. After percutaneous implantation in a proximal tibial metaphysis for four weeks in rabbits (n = 20, the Ti pin coated with the Ap layer showed significantly increased extraction torque compared with that of an uncoated Ti screw even with partial osteomyelitis present, owing to dense bone formation on the Ap layer in the cortical and medullary cavity regions. When the infection status was changed from “no osteomyelitis” to “partial osteomyelitis,” the extraction torque in the Ap group with “partial osteomyelitis” was almost identical to that for “no osteomyelitis” cases. These results suggest that the Ap layer formed by the room temperature process could effectively improve the fixation strength of the Ti pin for external fixation clinically even with partial osteomyelitis present.

  14. Corrosion of Ti6Al4V pins produced by direct metal laser sintering

    Energy Technology Data Exchange (ETDEWEB)

    Damborenea, J.J. de, E-mail: [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avenida Gregorio del Amo, 8, E-28040 Madrid (Spain); Arenas, M.A. [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avenida Gregorio del Amo, 8, E-28040 Madrid (Spain); Larosa, Maria Aparecida; Jardini, André Luiz [National Institute of Biofabrication (INCT-BIOFABRIS), State of University of Campinas (UNICAMP), Campinas (Brazil); School of Chemical Engineering, State of University of Campinas (UNICAMP), Campinas (Brazil); Carvalho Zavaglia, Cecília Amélia de [National Institute of Biofabrication (INCT-BIOFABRIS), State of University of Campinas (UNICAMP), Campinas (Brazil); Faculty of Mechanical Engineering, State of University of Campinas (UNICAMP), Campinas (Brazil); Conde, A. [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avenida Gregorio del Amo, 8, E-28040 Madrid (Spain)


    Highlights: • Pins of Ti6Al4V have been produced by DMLS technique. • Corrosion behavior of pins is similar to Ti6Al4V commercial Kirschner wires. • Formation of voluminous white oxide can appear at potentials higher than 2.4 V. • Defects originated during processing may cause this unusual behavior. - Abstract: Direct Metal Laser Sintering (DMLS) technique allows the manufacturing a wide variety of medical devices for any type of prosthetic surgery (HIP, dental, cranial, maxillofacial) as well as for internal fixation devices (K-Wires or Steinmann Pins). There are a large number of research studies on DMLS, including microstructural characterization, mechanical properties and those based on production quality assurance but the influence of porosity in the corrosion behavior of these materials not been sufficiently considered. In the present paper, surgical pins of Ti6Al4V have been produced by DMLS. After testing in a phosphate buffered saline solution, the surface of the titanium alloy appeared locally covered by a voluminous white oxide. This unexpected behavior was presumably due to the existence of internal defects in the pins as result of the manufacturing process. The importance of these defects—that might act as crevice nucleation sites- has been revealed by electrochemical techniques and confirmed by computed tomography.

  15. Auxin Regulates Cotton Fiber Initiation via GhPIN-Mediated Auxin Transport. (United States)

    Zhang, Mi; Zeng, Jian-Yan; Long, Hui; Xiao, Yue-Hua; Yan, Xing-Ying; Pei, Yan


    Cotton fibers are seed trichomes that make cotton unique compared with other plants. At anthesis, IAA, a major auxin in plants, accumulates in the fiber cell to promote cell initiation. However, many important aspects of this process are not clear. Here, auxin distribution patterns indicated by auxin-dependent DR5::GUS (β-glucuronidase) expression in cotton ovules were studied during fiber cell differentiation and cell initiation [-2 to 2 DPA (days post-anthesis)]. The nucellus and fiber cell were two major sites where auxin accumulates. The accumulation in the nucellus started from -1 DPA, and that in fiber cells from 0 DPA. Immunolocalization analysis further suggests that the IAA accumulation in fiber initials began before flower opening. Furthermore, we demonstrate that accumulated IAA in fiber initials was mainly from efflux transport and not from in situ synthesis. Eleven auxin efflux carrier (GhPIN) genes were identified, and their expression during ovule and fiber development was investigated. Ovule-specific suppression of multiple GhPIN genes in transgenic cotton inhibited both fiber initiation and elongation. In 0 DPA ovules, GhPIN3a, unlike other GhPIN genes, showed additional localization of the transcript in the outer integument. Collectively, these results demonstrate the important role of GhPIN-mediated auxin transport in fiber-specific auxin accumulation for fiber initiation. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email:

  16. Test module development to detect the flase call probe pins on microeprocessor test equipment (United States)

    Tang, L. W.; Ong, N. R.; Mohamad, I. S. B.; Alcain, J. B.; Retnasamy, V.


    Probe pins are useful for electrical testing of microelectronic components, printed circuit board assembly (PCBA), microprocessors and other electronic devices due to it provides the conductivity test based on specific device circuit design. During the repeatable test runs, the load of test modules, contact failures and the current conductivity induces layer wear off all the tip of probe pins contact. Contamination will be build-up on probe pins and increased contact resistivity which results of cost loss and time loss for rectifying programs, rectifying testers and exchanging new probe pins. In this study, a resistivity approach will be developed to provide "Testing of Test Probes". The test module based on "Four-wire Ohm measurement" method with two alternative ways of applying power supply, that are 9V from a single power supply and 5V from Arduino UNO power supply were demonstrated to measure the small resistance value of microprocessor probe pin. A microcontroller with VEE Pro software was used to record the measurement data. The accuracy of both test modules were calibrated under different temperature conditions and result shows that 9V from a single power supply test module has higher measurement accuracy.

  17. Intrinsic flux pinning mechanisms in different thickness MgB2 films

    Directory of Open Access Journals (Sweden)

    C. Yang


    Full Text Available MgB2 films in four thickness (60 nm, 200nm, 600nm and 1μm have been fabricated by hybrid physical–chemical vapor deposition technique (HPCVD. By measuring the magnetization hysteresis loops and the resistivity, we have obtained the transport and magnetic properties of the four films. After that, the pinning mechanisms in them were discussed. Comparing the pinning behaviors in these ultrathin films, thin films and thick films, it was found that there exist different pinning types in MgB2 films of different thickness. In combination with the study of the surface morphology, cross-section and XRD results, we concluded that MgB2 films had different growth modes in different growth stages. For thin films, films grew along c axis, and grain boundaries acted as surface pinning. While for thick films, films grew along c axis at first, and then changed to a-b axis growth. As a result, the a-b axis grains acted as strong volume pinning.

  18. Improvement of high T{sub c} superconductor by near-optimum pinning centers created by high Z, high-energy ions

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy, E-mail: [Texas Center for Superconductivity, Physics Department, 632 Science and Research Bldg. 1, University of Houston, Houston, TX 77204-5005 (United States); Sawh, Ravi-Persad; Parks, Drew; Mayes, Billy [Texas Center for Superconductivity, Physics Department, 632 Science and Research Bldg. 1, University of Houston, Houston, TX 77204-5005 (United States)


    Damage tracks left by high Z, high-energy ions in high temperature superconductor (HTS) can serve the need to pin in place the magnetic field quanta. Such pinning centers (PCs) can serve to dramatically increase the critical current density, J{sub c}. Specific energy loss, S{sub e}, which is effective in the YBCO superconductor (YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}) lies in the range 0.7 Less-Than-Or-Slanted-Equal-To S{sub e} Less-Than-Or-Slanted-Equal-To 3.5 keV/A. At 77 K, a sharp peak in J{sub c} occurs at S{sub e} {approx} 2.1 keV/A, for fluences of 10{sup 12} ions/cm{sup 2}, where record in-field J{sub c} is achieved in large-grain YBCO. For example, J{sub c} = 340 kA/cm{sup 2} at 77 K, applied field of 1 T. At closely similar conditions record in-field J{sub c} is achieved in thick coated conductor, e.g., J{sub c} = 543 kA/cm{sup 2} at 77 K, 1 T. When corrected to the optimum S{sub e}, this J{sub c} increases to 770 kA/cm{sup 2}. These near-optimum PCs have very small diameter of damage (d{sub d} {approx} 6.6 nm) close to the value, predicted theoretically. However, they are very discontinuous, whereas theory predicts that continuous columnar PCs are the best to obtain high J{sub c}. We find that the advantages of discontinuous PCs at S{sub e} = 2.1 keV/A, are (a) a factor of 12 less damage to the HTS (resulting in improved percolation and T{sub c}) and (b) entanglement of fluxoids (even for parallel PCs). This results in five times higher J{sub c} than can be achieved with continuous columnar PCs. In large-grain HTS, these pinning centers increase J{sub c} by a factor of 17, indicating that the dominant reduction of J{sub c} in large-grain HTS is due not to weak links, voids, non-optimum oxygenation, etc., but to a dearth of pinning centers.

  19. Weak KAM theory for a weakly coupled system of Hamilton–Jacobi equations

    KAUST Repository

    Figalli, Alessio


    Here, we extend the weak KAM and Aubry–Mather theories to optimal switching problems. We consider three issues: the analysis of the calculus of variations problem, the study of a generalized weak KAM theorem for solutions of weakly coupled systems of Hamilton–Jacobi equations, and the long-time behavior of time-dependent systems. We prove the existence and regularity of action minimizers, obtain necessary conditions for minimality, extend Fathi’s weak KAM theorem, and describe the asymptotic limit of the generalized Lax–Oleinik semigroup. © 2016, Springer-Verlag Berlin Heidelberg.

  20. Micro-PIV visualization and numerical simulation of flow and heat transfer in three micro pin-fin heat sinks


    Xia, Guodong; Chen, Zhuo; Cheng, Lixin; Ma, Dandan; Zhai, Yuling; Yang, Yuchen


    This paper presents the experimental results of laminar flow behavior of water in circular micro pin-fin (C-MPF), square micro pin-fin (S-MPF) and diamond micro pin-fin (D-MPF) heat sinks using micro-PIV flow visualization technology at first. All three micro pin-fin heat sinks have a hydraulic diameter of 200 μm. Second, numerical simulation results of the fluid flow characteristics in these heat sinks with CFD are compared to the experimental results of fluid flow behaviors measured with th...

  1. Effects of neutron irradiation on pinning force scaling in state-of-the-art Nb3Sn wires

    CERN Document Server

    Baumgartner, T; Weber, H W; Flükiger, R; Scheuerlein, C; Bottura, L


    We present an extensive irradiation study involving five state-of-the-art Nb3Sn wires which were subjected to sequential neutron irradiation up to a fast neutron fluence of 1.6 x 10(22) m(-2) (E > 0.1 MeV). The volume pinning force of short wire samples was assessed in the temperature range from 4.2 to 15 K in applied fields of up to 7 T by means of SQUID magnetometry in the unirradiated state and after each irradiation step. Pinning force scaling computations revealed that the exponents in the pinning force function differ significantly from those expected for pure grain boundary pinning, and that fast neutron irradiation causes a substantial change in the functional dependence of the volume pinning force. A model is presented, which describes the pinning force function of irradiated wires using a two-component ansatz involving a point-pinning contribution stemming from radiation induced pinning centers. The dependence of this point-pinning contribution on fast neutron fluence appears to be a universal funct...

  2. Development of breached pin performance analysis code SAFFRON (System of Analyzing Failed Fuel under Reactor Operation by Numerical method)

    Energy Technology Data Exchange (ETDEWEB)

    Ukai, Shigeharu [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center


    On the assumption of fuel pin failure, the breached pin performance analysis code SAFFRON was developed to evaluate the fuel pin behavior in relation to the delayed neutron signal response during operational mode beyond the cladding failure. Following characteristic behavior in breached fuel pin is modeled in 3-dimensional finite element method : pellet swelling by fuel-sodium reaction, fuel temperature change, and resultant cladding breach extension and delayed neutron precursors release into coolant. Particularly, practical algorithm of numerical procedure in finite element method was originally developed in order to solve the 3-dimensional non-linear contact problem between the swollen pellet due to fuel-sodium reaction and breached cladding. (author).

  3. On-chip membrane-based GaInAs/InP waveguide-type p-i-n photodiode fabricated on silicon substrate. (United States)

    Gu, Zhichen; Uryu, Tatsuya; Nakamura, Nagisa; Inoue, Daisuke; Amemiya, Tomohiro; Nishiyama, Nobuhiko; Arai, Shigehisa


    Toward the realization of ultralow-power-consumption on-chip optical interconnection, two types of membrane-based GaInAs/InP p-i-n photodiodes were fabricated on Si host substrates by using benzocyclobutene bonding. A responsivity of 0.95 A/W was estimated with a conventional waveguide-type photodiode with an ∼30-μm-long absorption region. The fitting curves based on the experimental data indicated that an absorption efficiency above 90% could be achieved with a length of 10 μm. In addition, increased absorption per length of a photonic crystal waveguide-type photodiode was obtained because of the enhanced lateral optical confinement or the slow-light effect, enabling a further reduction in the device length.

  4. Crystal structure of pymetrozine

    Directory of Open Access Journals (Sweden)

    Youngeun Jeon


    Full Text Available The title compound, C10H11N5O {systematic name: 6-methyl-4-[(E-(pyridin-3-ylmethylideneamino]-4,5-dihydro-1,2,4-triazin-3(2H-one}, C10H11N5O, is used as an antifeedant in pest control. The asymmetric unit comprises two independent molecules, A and B, in which the dihedral angles between the pyridinyl and triazinyl ring planes [r.m.s. deviations = 0.0132 and 0.0255 ] are 11.60 (6 and 18.06 (4°, respectively. In the crystal, N—H...O, N—H...N, C—H...N and C—H...O hydrogen bonds, together with weak π–π interactions [ring-centroid separations = 3.5456 (9 and 3.9142 (9 Å], link the pyridinyl and triazinyl rings of A molecules, generating a three-dimensional network.

  5. Theory of the intermediate stage of crystal growth with applications to insulin crystallization (United States)

    Barlow, D. A.


    A theory for the intermediate stage of crystal growth, where two defining equations one for population continuity and another for mass-balance, is used to study the kinetics of the supersaturation decay, the homogeneous nucleation rate, the linear growth rate and the final distribution of crystal sizes for the crystallization of bovine and porcine insulin from solution. The cited experimental reports suggest that the crystal linear growth rate is directly proportional to the square of the insulin concentration in solution for bovine insulin and to the cube of concentration for porcine. In a previous work, it was shown that the above mentioned system could be solved for the case where the growth rate is directly proportional to the normalized supersaturation. Here a more general solution is presented valid for cases where the growth rate is directly proportional to the normalized supersaturation raised to the power of any positive integer. The resulting expressions for the time dependent normalized supersaturation and crystal size distribution are compared with experimental reports for insulin crystallization. An approximation for the maximum crystal size at the end of the intermediate stage is derived. The results suggest that the largest crystal size in the distribution at the end of the intermediate stage is maximized when nucleation is restricted to be only homogeneous. Further, the largest size in the final distribution depends only weakly upon the initial supersaturation.

  6. Extrapolating Weak Selection in Evolutionary Games (United States)

    Wu, Bin; García, Julián; Hauert, Christoph; Traulsen, Arne


    In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By “qualitatively valid” we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more) strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies . In particular, rank changes are almost certain for , which jeopardizes the predictive power of results derived for weak selection. PMID:24339769

  7. Extrapolating weak selection in evolutionary games.

    Directory of Open Access Journals (Sweden)

    Bin Wu

    Full Text Available In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By "qualitatively valid" we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies [Formula: see text]. In particular, rank changes are almost certain for [Formula: see text], which jeopardizes the predictive power of results derived for weak selection.

  8. Weak Acid Ionization Constants and the Determination of Weak Acid-Weak Base Reaction Equilibrium Constants in the General Chemistry Laboratory (United States)

    Nyasulu, Frazier; McMills, Lauren; Barlag, Rebecca


    A laboratory to determine the equilibrium constants of weak acid negative weak base reactions is described. The equilibrium constants of component reactions when multiplied together equal the numerical value of the equilibrium constant of the summative reaction. The component reactions are weak acid ionization reactions, weak base hydrolysis…

  9. Effect of a weak transverse magnetic field on the morphology and orientation of directionally solidified Al-Ni alloys (United States)

    Li, Hanxiao; Fautrelle, Yves; Hou, Long; Du, Dafan; Zhang, Yikun; Ren, Zhongming; Lu, Xionggang; Moreau, Rene; Li, Xi


    The influence of a weak transverse magnetic field on the morphology and orientation of Al3Ni dendrites in directionally solidified Al-12 wt% Ni alloys was investigated. The experimental results indicated that the magnetic field caused segregation. It was also found that the application of a magnetic field decreased the primary dendrite spacing. By means of electronic backscatter diffraction (EBSD) analysis, the orientation of the Al3Ni dendrite was studied. In the case of no magnetic field, the crystal direction of the Al3Ni crystal was oriented along the solidification direction. When a transverse magnetic field was applied, the crystal direction rotated to the magnetic field direction, whereas the crystal direction remained oriented along the solidification direction. The above experimental results are discussed in the context of thermoelectric magnetic convection (TEMC) and crystal anisotropy.

  10. A theoretical overview of hypernuclear weak decay

    Energy Technology Data Exchange (ETDEWEB)

    Chumillas, C. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, E-08028 Barcelona (Spain); Garbarino, G. [Dipartimento di Fisica Teorica, Universita di Torino and INFN, Sezione di Torino, I-10125 Torino (Italy)], E-mail:; Parreno, A.; Ramos, A. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, E-08028 Barcelona (Spain)


    The physics of the weak decay of hypernuclei is briefly reviewed from a theoretical point of view. Special regard is devoted to the recent progress concerning the determination of the non-mesonic decay widths and the asymmetry parameters. Convincing evidence has been achieved for a solution of the long-standing puzzle on the ratio {gamma}{sub n}/{gamma}{sub p}. Very recently, it has been shown that the exchange of a {pi}{pi} pair in the weak mechanism plays a crucial role in explaining the discrepancies between theory and experiment on the decay asymmetries.

  11. Weak interactions at high energies. [Lectures, review

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.


    Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references. (JFP)

  12. From Suitable Weak Solutions to Entropy Viscosity

    KAUST Repository

    Guermond, Jean-Luc


    This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i) to recall basic mathematical properties of the three-dimensional incompressible Navier-Stokes equations and to show how they might relate to LES (ii) to introduce an entropy viscosity technique based on the notion of suitable weak solution and to illustrate numerically this concept. © 2010 Springer Science+Business Media, LLC.

  13. A Continuation Method for Weakly Kannan Maps

    Directory of Open Access Journals (Sweden)

    Ariza-Ruiz David


    Full Text Available The first continuation method for contractive maps in the setting of a metric space was given by Granas. Later, Frigon extended Granas theorem to the class of weakly contractive maps, and recently Agarwal and O'Regan have given the corresponding result for a certain type of quasicontractions which includes maps of Kannan type. In this note we introduce the concept of weakly Kannan maps and give a fixed point theorem, and then a continuation method, for this class of maps.

  14. Some Aspects of Crystal Centering During X-ray High-throughput Protein Crystallography Experiment (United States)

    Gaponov, Yu. A.; Matsugaki, N.; Sasajima, K.; Igarashi, N.; Wakatsuki, S.

    A set of algorithms and procedures of a crystal loop centering during X-ray high-throughput protein crystallography experiment has been designed and developed. A simple algorithm of the crystal loop detection and preliminary recognition has been designed and developed. The crystal loop detection algorithm is based on finding out the crystal loop ending point (opposite to the crystal loop pin) using image cross section (digital image column) profile analysis. The crystal loop preliminary recognition procedure is based on finding out the crystal loop sizes and position using image cross section profile analysis. The crystal loop fine recognition procedure based on Hooke-Jeeves pattern search method with an ellipse as a fitting pattern has been designed and developed. The procedure of restoring missing coordinate of the crystal loop is described. Based on developed algorithms and procedures the optimal auto-centering procedure has been designed and developed. A procedure of optimal manual crystal centering (Two Clicks Procedure) has been designed and developed. Developed procedures have been integrated into control software system PCCS installed at crystallography beamlines Photon Factory BL5A and PF-AR NW12, KEK.

  15. Mixed-parity superconductivity in centrosymmetric crystals


    Sergienko, I. A.


    A weak-coupling formalism for superconducting states possessing both singlet (even parity) and triplet (odd parity) components of the order parameter in centrosymmetric crystals is developed. It is shown that the quasiparticle energy spectrum may be non-degenerate even if the triplet component is unitary. The superconducting gap of a mixed-parity state may have line nodes in the strong spin-orbit coupling limit. The pseudospin carried by the superconducting electrons is calculated, from which...

  16. Mechanical Wave Propagation within Nanogold Granular Crystals


    Zheng, Bowen; Xu, Jun


    We computationally investigate the wave propagation characteristics of nanoscopic granular crystals composed of one-dimensionally arrayed gold nanoparticles using molecular dynamics simulation. We examine two basic configurations, i.e. homogeneous lattices and diatomic lattices with mass-mismatch. We discover that homogeneous lattices of gold nanospheres support weakly dissipative and highly localized solitary wave at 300 K, while diatomic lattices have a good tuning ability of transmittance ...

  17. Fuzzy Approximation-Based Global Pinning Synchronization Control of Uncertain Complex Dynamical Networks. (United States)

    Li, Xiao-Jian; Yang, Guang-Hong


    This paper is concerned with the global pinning synchronization problem of uncertain complex dynamical networks with communication constraints. First, an adaptive fuzzy controller is designed within a given compact set. In addition, a robust controller is introduced outside the compact set to pull back the system states. Then, a new pinning control scheme is given such that the global synchronization can be ensured. Moreover, via the Lyapunov theory and graph theory, the synchronization errors are proved to be asymptotically convergent. Especially, in an uncertainty-free environment, the proposed control scheme includes two easy-to-implement pinning control strategies as special cases, which improve the existing results from the view point of reducing the number of feedback controllers. Finally, two simulation examples are provided to validate the theoretical results.

  18. Corrosion of Ti6Al4V pins produced by direct metal laser sintering (United States)

    de Damborenea, J. J.; Arenas, M. A.; Larosa, Maria Aparecida; Jardini, André Luiz; de Carvalho Zavaglia, Cecília Amélia; Conde, A.


    Direct Metal Laser Sintering (DMLS) technique allows the manufacturing a wide variety of medical devices for any type of prosthetic surgery (HIP, dental, cranial, maxillofacial) as well as for internal fixation devices (K-Wires or Steinmann Pins). There are a large number of research studies on DMLS, including microstructural characterization, mechanical properties and those based on production quality assurance but the influence of porosity in the corrosion behavior of these materials not been sufficiently considered. In the present paper, surgical pins of Ti6Al4V have been produced by DMLS. After testing in a phosphate buffered saline solution, the surface of the titanium alloy appeared locally covered by a voluminous white oxide. This unexpected behavior was presumably due to the existence of internal defects in the pins as result of the manufacturing process. The importance of these defects-that might act as crevice nucleation sites- has been revealed by electrochemical techniques and confirmed by computed tomography.

  19. Development and testing of a zero stitch MLI blanket using plastic pins for space use (United States)

    Hatakenaka, Ryuta; Miyakita, Takeshi; Sugita, Hiroyuki; Saitoh, Masanori; Hirai, Tomoyuki


    New types of MLI blanket have been developed to achieve high thermal performance while maintaining production and assembly workability equivalent to the conventional type. Tag-pins, which are widely used in commercial applications to hook price tags to products, are used to fix the films in place and the pin material is changed to polyetheretherketone (PEEK) for use in space. Thermal performance is measured by using a boil-off calorimeter, in which a rectangular liquid nitrogen tank is used to evaluate the degradation at the bending corner and joint of the blanket. Zero-stitch- and multi-blanket-type MLIs show significantly improved thermal performance (ɛeff is smaller than 0.0050 at room temperature) despite having the same fastener interface as traditional blankets, while the venting design and number of tag-pins are confirmed as appropriate in a depressurization test.

  20. Pinning synchronization of memristor-based neural networks with time-varying delays. (United States)

    Yang, Zhanyu; Luo, Biao; Liu, Derong; Li, Yueheng


    In this paper, the synchronization of memristor-based neural networks with time-varying delays via pinning control is investigated. A novel pinning method is introduced to synchronize two memristor-based neural networks which denote drive system and response system, respectively. The dynamics are studied by theories of differential inclusions and nonsmooth analysis. In addition, some sufficient conditions are derived to guarantee asymptotic synchronization and exponential synchronization of memristor-based neural networks via the presented pinning control. Furthermore, some improvements about the proposed control method are also discussed in this paper. Finally, the effectiveness of the obtained results is demonstrated by numerical simulations. Copyright © 2017 Elsevier Ltd. All rights reserved.