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Sample records for al commun pure

  1. Resistivity measurements of neutron-irradiated pure metals and Al-Zn alloys

    NASA Technical Reports Server (NTRS)

    Horak, J. A.

    1968-01-01

    Report presents resistivity measurements and their interpretation for neutron-irradiated pure metals and Al-Zn alloys. The influence of temperature, the role of point defects, and the aging behavior on resistivity are considered. The experimental procedures and results are discussed in detail.

  2. Tracer diffusion in pure and boron-doped Ni/sub 3/Al

    SciTech Connect

    Hoshino, K.; Rothman, S.J.; Averback, R.S.

    1988-05-01

    Diffusion of /sup 63/Ni has been measured in pure and boron-doped polycrystalline Ni/sub 3/Al intermetallic compounds as a function of temperature (692-1352/sup 0/C), Al concentration (24-26 at.%Al), and boron content (0-500 wt ppm). Volume and grain-boundary diffusion of /sup 60/Co and /sup 68/Ge have also been measured in pure Ni/sub 3/Al. Both conventional grinding and ion beam sputtering techniques have been used for the determination of the concentration profiles. The diffusivity of Ni,D*/sub Ni/ is independent of Al content above 1000/sup 0/C, indicating that antisite defects are prevailing on both sides of stoichiometry. However, D*/sub Ni/ shows a minimum at the stoichiometric composition below 1000/sup 0/C, and this trend becomes clearer with decreasing temperature. The diffusivities of /sup 60/Co and /sup 68/Ge are also independent of Al concentration in the temperature range between 880 and 1200/sup 0/C, but their grain-boundary diffusion depends on Al concentration. The addition of boron linearly increases D*/sub Ni/ above 1000/sup 0/C, but at lower temperatures, D*/sub Ni/ in off-stoichiometric compositions decreases to the value for stoichiometric Ni/sub 3/Al on the addition of 100 wt ppm boron, and then increases as above with the further additions of boron to -- 500 wt ppm. The present diffusion data suggest that a small concentration of vacancies, independent of temperature, is present on both sides of, and at, stoichiometry at low temperature.

  3. Spherical nanoindentation stress-strain curves of commercially pure titanium and Ti-6Al-4V

    DOE Data Explorer

    Weaver, Jordan S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Priddy, Matthew W. [Georgia Inst. of Technology, Atlanta, GA (United States); McDowell, David L. [Georgia Inst. of Technology, Atlanta, GA (United States); Kalidindi, Surya R. [Georgia Inst. of Technology, Atlanta, GA (United States)

    2016-07-27

    Spherical nanoindentation combined with electron back-scattered diffraction was employed to characterize the grain-scale elastic and plastic anisotropy of single crystal alpha-Ti for commercially pure (CP-Ti) and alloyed (Ti-64) titanium. In addition, alpha-beta Ti (single colony) grains were characterized. The data set includes the nanoindentation force, displacement, and contact stiffness, the nanoindentation stress-strain analysis, and the alpha-Ti crystal orientations. Details of the samples and experimental protocols can be found in Weaver et al. (2016) Acta Materialia doi:10.1016/j.actamat.2016.06.053.

  4. Effect of hydrogen sulfide on aqueous corrosion of commercially pure Al 99.5

    SciTech Connect

    Bjoergum, A.; Sigurdsson, H.; Nisancioglu, K.

    1995-08-01

    Recently, there has been interest in the use of aluminum alloys as possible alternatives to carbon steel for handling oilfield products, such as brines with dissolved carbon dioxide (CO{sub 2}) and H{sub 2}S. The effect of hydrogen sulfide on the corrosion behavior of commercially pure aluminum (DIN Al 99.5 [AA 1050A]) in chloride solutions containing carbon dioxide, bicarbonate, and copper ions at 30 C and 80 C was investigated using natural immersion corrosion tests, cathodic polarization, and scanning electron microscopy. The highest corrosion rates were observed in solutions containing Cu{sup 2+} but with no H{sub 2}S content because of copper deposition on the metal surface. Significant pitting occurred at 80 C. With H{sub 2}S in the solution, pitting corrosion was eliminated by removal of Cu{sup 2+} and other deleterious heavy-metal ion impurities form the solution in the form of insoluble sulfides. If H{sub 2}S was introduced after the copper deposited on the aluminum surface, no inhibiting effect was detected at 30 C, but a degree of inhibition still was observed at 80 C, presumably because the deposited copper was converted more effectively into copper sulfide at the higher temperature.

  5. Observation of multiband effects in the microwave complex conductivity of pure and Al-doped MgB 2 samples

    NASA Astrophysics Data System (ADS)

    Di Gennaro, E.; Lamura, G.; Palenzona, A.; Putti, M.; Andreone, A.

    2004-08-01

    There is presently a general agreement that the simple inter-metallic compound MgB 2 is a conventional, phonon mediated, superconductor, and that the anomalies in its behaviour can be consistently explained by the existence of two different gaps. We present a study of the complex conductivity as a function of temperature in pure and Al-doped MgB 2 pellets by using a dielectrically loaded resonant cavity at 19 GHz.

  6. Restricted-Access Al-Mediated Material Transport in Al Contacting of PureGaB Ge-on-Si p + n Diodes

    NASA Astrophysics Data System (ADS)

    Sammak, Amir; Qi, Lin; Nanver, Lis K.

    2015-12-01

    The effectiveness of using nanometer-thin boron (PureB) layers as interdiffusion barrier to aluminum (Al) is studied for a contacting scheme specifically developed for fabricating germanium-on-silicon (Ge-on-Si) p + n photodiodes with an oxide-covered light entrance window. Contacting is achieved at the perimeter of the Ge-island anode directly to an Al interconnect metallization. The Ge is grown in oxide windows to the Si wafer and covered by a B and gallium (Ga) layer stack (PureGaB) composed of about a nanometer of Ga for forming the p + Ge region and 10 nm of B as an interdiffusion barrier to the Al. To form contact windows, the side-wall oxide is etched away, exposing a small tip of the Ge perimeter to Al that from this point travels about 5 μm into the bulk Ge crystal. In this process, Ge and Si materials are displaced, forming Ge-filled V-grooves at the Si surface. The Al coalesces in grains. This process is studied here by high-resolution cross-sectional transmission electron microscopy and energy dispersive x-ray spectroscopy that confirm the purities of the Ge and Al grains. Diodes are fabricated with different geometries and statistical current-voltage characterization reveals a spread that can be related to across-the-wafer variations in the contact processing. The I- V behavior is characterized by low dark current, low contact resistance, and breakdown voltages that are suitable for operation in avalanching modes. The restricted access to the Ge of the Al inducing the Ge and Si material transport does not destroy the very good electrical characteristics typical of PureGaB Ge-on-Si diodes.

  7. Pure AlN layers in metal-polar AlGaN/AlN/GaN and AlN/GaN heterostructures grown by low-temperature ammonia-based molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Kaun, Stephen W.; Mazumder, Baishakhi; Fireman, Micha N.; Kyle, Erin C. H.; Mishra, Umesh K.; Speck, James S.

    2015-05-01

    When grown at a high temperature (820 °C) by ammonia-based molecular beam epitaxy (NH3-MBE), the AlN layers of metal-polar AlGaN/AlN/GaN heterostructures had a high GaN mole fraction (∼0.15), as identified by atom probe tomography in a previous study (Mazumder et al 2013 Appl. Phys. Lett. 102 111603). In the study presented here, growth at low temperature (<740 °C) by NH3-MBE yielded metal-polar AlN layers that were essentially pure at the alloy level. The improved purity of the AlN layers grown at low temperature was correlated to a dramatic increase in the sheet density of the two-dimensional electron gas (2DEG) at the AlN/GaN heterointerface. Through application of an In surfactant, metal-polar AlN(3.5 nm)/GaN and AlGaN/AlN(2.5 nm)/GaN heterostructures grown at low temperature yielded low 2DEG sheet resistances of 177 and 285 Ω/□, respectively.

  8. Fabrication and microstructural characterization of Al/Zn-enriched layers on pure magnesium

    SciTech Connect

    Mola, Renata

    2013-04-15

    Al/Zn-enriched surface layers were fabricated by heating Mg specimens in contact with Al–Zn powder mixtures in a vacuum furnace at 445 °C. The layer formation process took place through partial melting at the Mg-substrate/powder-mixture interface. Heating times ranged from 20 to 80 min. The layer microstructure and composition were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The layers were 100–900 μm in thickness, depending on the treatment time. The examination results revealed that the layers consisted of Mg{sub 17}(Al,Zn){sub 12} and Mg{sub 5}Al{sub 2}Zn{sub 2} intermetallic phases and a solid solution of Al and Zn in Mg. Between the Al/Zn-enriched layer and the Mg substrate, there was a transition zone of a solid solution of Al and Zn in Mg with a thickness of 20–30 μm. The layers had much higher microhardness than the Mg substrate. - Highlights: ► The layers were produced by heating Mg in contact with an Al–Zn powder mixture. ► The layer formation process at 445 °C proceeded with the liquid phase contribution. ► The Al/Zn-enriched layers were thick, dense, uniform and continuous. ► The layers contained Mg–Al–Zn intermetallic phases. ► The hardness of the layers was much higher than that of the Mg substrate.

  9. Stability of Fe,Al-bearing bridgmanite in the lower mantle and synthesis of pure Fe-bridgmanite.

    PubMed

    Ismailova, Leyla; Bykova, Elena; Bykov, Maxim; Cerantola, Valerio; McCammon, Catherine; Boffa Ballaran, Tiziana; Bobrov, Andrei; Sinmyo, Ryosuke; Dubrovinskaia, Natalia; Glazyrin, Konstantin; Liermann, Hanns-Peter; Kupenko, Ilya; Hanfland, Michael; Prescher, Clemens; Prakapenka, Vitali; Svitlyk, Volodymyr; Dubrovinsky, Leonid

    2016-07-01

    The physical and chemical properties of Earth's mantle, as well as its dynamics and evolution, heavily depend on the phase composition of the region. On the basis of experiments in laser-heated diamond anvil cells, we demonstrate that Fe,Al-bearing bridgmanite (magnesium silicate perovskite) is stable to pressures over 120 GPa and temperatures above 3000 K. Ferric iron stabilizes Fe-rich bridgmanite such that we were able to synthesize pure iron bridgmanite at pressures between ~45 and 110 GPa. The compressibility of ferric iron-bearing bridgmanite is significantly different from any known bridgmanite, which has direct implications for the interpretation of seismic tomography data. PMID:27453945

  10. Stability of Fe,Al-bearing bridgmanite in the lower mantle and synthesis of pure Fe-bridgmanite

    PubMed Central

    Ismailova, Leyla; Bykova, Elena; Bykov, Maxim; Cerantola, Valerio; McCammon, Catherine; Boffa Ballaran, Tiziana; Bobrov, Andrei; Sinmyo, Ryosuke; Dubrovinskaia, Natalia; Glazyrin, Konstantin; Liermann, Hanns-Peter; Kupenko, Ilya; Hanfland, Michael; Prescher, Clemens; Prakapenka, Vitali; Svitlyk, Volodymyr; Dubrovinsky, Leonid

    2016-01-01

    The physical and chemical properties of Earth’s mantle, as well as its dynamics and evolution, heavily depend on the phase composition of the region. On the basis of experiments in laser-heated diamond anvil cells, we demonstrate that Fe,Al-bearing bridgmanite (magnesium silicate perovskite) is stable to pressures over 120 GPa and temperatures above 3000 K. Ferric iron stabilizes Fe-rich bridgmanite such that we were able to synthesize pure iron bridgmanite at pressures between ~45 and 110 GPa. The compressibility of ferric iron–bearing bridgmanite is significantly different from any known bridgmanite, which has direct implications for the interpretation of seismic tomography data. PMID:27453945

  11. Effect of laser spot size on the residual stress field of pure Al treated by laser shock processing: Simulations

    NASA Astrophysics Data System (ADS)

    Dai, F. Z.; Lu, J. Z.; Zhang, Y. K.; Wen, D. P.; Ren, X. D.; Zhou, J. Z.

    2014-10-01

    Laser shock processing (LSP) is a unique surface treatment technique. It induces high-depth compressive residual stresses for improved fatigue or stress corrosion cracking resistance. FEM simulation is an effective method to predict material behavior by LSP. A 2D quarter-infinite model was used to simulate the material behaviors of commercially pure Al by LSP. Different peak pressure with different laser spot diameter was applied to surface of pure Al. Each simulation included two steps: (i) explicit dynamics analysis for the analysis of the LSP; (ii) static equilibrium analysis for springback deformation analysis. The following conclusions could be made: (1) Plastically affected depth increased with the increase of laser spot diameter. There was an ultimate value about plastically affected depth when the laser spot diameter increased to some value, and the ultimate value was consistent with Ballard' model. When the laser spot diameter was small, there still existed tensile residual stresses on the surface layer of material although the peak pressure was below 2.5 HEL. When the diameter laser spot diameter was big enough, the tensile residual stresses on the surface layer of material were converted into compressive residual stresses although the peak pressure was higher than 2.5 HEL.

  12. Strain localization during tensile Hopkinson bar testing of commercially pure titanium and Ti6Al4V titanium alloy

    NASA Astrophysics Data System (ADS)

    Moćko, Wojciech; Kruszka, Leopold; Brodecki, Adam

    2015-09-01

    The goal of the analysis was to determine the strain localization for various specimen shapes (type A and type B according to PN-EN ISO 26203-1 standard) and different loading conditions, i.e. quasi- static and dynamic. Commercially pure titanium (Grade 2) and titanium alloy Ti6Al4V (Grade 5) were selected for the tests. Tensile loadings were applied out using servo-hydraulic testing machine and tensile Hopkinson bar with pre-tension. The results were recorded using ARAMIS system cameras and fast camera Phantom V1210, respectively at quasi-static and dynamic loading conditions. Further, specimens outline was determined on the basis of video data using TEMA MOTION software. The strain distribution on the specimen surface was estimated using digital image correlation method. The larger radius present in the specimen of type B in comparison to specimen of type A, results in slight increase of the elongation for commercially pure titanium at both quasi-static and dynamic loading conditions. However this effect disappears for Ti6Al4V alloy. The increase of the elongation corresponds to the stronger necking effect. Material softening due to increase of temperature induced by plastic work was observed at dynamic loading conditions. Moreover lower elongation at fracture point was found at high strain rates for both materials.

  13. Influence of oxidative nanopatterning and anodization on the fatigue resistance of commercially pure titanium and Ti-6Al-4V.

    PubMed

    Ketabchi, Amirhossein; Weck, Arnaud; Variola, Fabio

    2015-04-01

    With an increasingly aging population, a significant challenge in implantology is the creation of biomaterials that actively promote tissue integration and offer excellent mechanical properties. Engineered surfaces with micro- and nanoscale topographies have shown great potential to control and direct biomaterial-host tissue interactions. Two simple yet efficient chemical treatments, oxidative nanopatterning and anodization, have demonstrated the ability to confer exciting new bioactive capacities to commercially pure titanium and Ti-6Al-4V alloy. However, the resulting nanoporous and nanotubular surfaces require careful assessment in regard to potential adverse effects on the fatigue resistance, a factor which may ultimately cause premature failure of biomedical implants. In this work, we have investigated the impact of oxidative nanopatterning and anodization on the fatigue resistance of commercially pure titanium and Ti-6Al-4V. Quantitative (e.g., S-N curves) and qualitative analyses were carried out to precisely characterize the fatigue response of treated metals and compare it to that of polished controls. Scanning electron microscopy (SEM) imaging revealed the effects of cyclic loading on the fracture surface and on the structural integrity of chemically grown nanostructured oxides. Results from this study reinforce the importance of mechanical considerations in the development and optimization of micro- and nanoscale surface treatments for metallic biomedical implants.

  14. Corrosion of commercially pure Al 99.5 in chloride solutions containing carbon dioxide, bicarbonate, and copper ions

    SciTech Connect

    Bjoergum, A.; Sigurdsson, H.; Nisancioglu, K.

    1995-07-01

    There has been a certain amount of interest recently in the use of aluminum alloys as an alternative material to steel for the processing and transmission of produced crude oil in the offshore oil industry. The corrosion behavior of aluminum in solutions containing chloride, carbon dioxide, bicarbonate, and copper ions at various concentrations and temperatures has been of frequent interest in connection with applications in direct contact with a corrosive aqueous phase, such as in natural waters and produced brines. Available information about the combined effects of these species on aluminum is conflicting. A more systematic study was undertaken using commercially pure aluminum (DIN Al 99.5 [AA 1050A]) as the test material. Corrosion tests performed in Cl{sup {minus}} solutions containing these species indicated that dissolved CO{sub 2}-HCO{sub 3}{sup {minus}} combinations giving a neutral solution pH resulted in low corrosion rates for aluminum. The added presence of small Cu{sup 2+} concentrations could have been detrimental but did not produce a synergistic effect. High temperatures in general caused increased corrosion rates, except near pH 9, where the cathodic intermetallic phases passivated. The observed corrosion behavior was explained in terms of cathodic polarization data for the aluminum matrix and the Al{sub 3}Fe intermetallic particles.

  15. Effect of shot peening and grain refinement on the fatigue life and strength of commercially pure Al and two of its alloys: Al-2024-T3 and Al-7075-T6

    NASA Astrophysics Data System (ADS)

    Qandil, A.; Zaid, Adnan I. O.

    2016-08-01

    Aluminum and its alloys are widely used materials in automobile, aircraft and space craft industries due to their high strength- to- weight ratio and corrosion resistance beside their other useful properties. They are the second materials in use after steel alloys. Most of the failures in parts of aircrafts and space vehicles are mainly caused by fatigue and stress corrosion cracking. In this paper, the effect of shot peening on the fatigue life of commercially pure aluminumand two of its alloys namely:Al-2024 and Al-7075-T6 is presented and discussed. Furthermore, the effect of addition of vanadium to Al and Al grain refined by Ti and Ti+Bon Its fatigue life and strengthis also presented and discussed using scanning electron microscope, SEM. It was that shot peening and the addition of V toAl and Al onAl grain refined by Ti and Ti+B have resulted in enhancement of the fatigue life and strength. Ffinally, the effect of shot peening on the surface quality of the peened parts is also presented and discussed.

  16. Response on the ``Comment on propagation properties of Hermite-cosh-Gaussian laser beams'' in [Opt. Commun. 186 (2000) 269

    NASA Astrophysics Data System (ADS)

    Belafhal, A.; Ibnchaikh, M.

    2002-03-01

    Yu et al. present a comment on our paper [Opt. Commun. 186 (2000) 269] by examining some used mathematical equations. They have demonstrated, in their comment, the known summation theorem which is found in all mathematical references (see for example: [I.S. Gradshteyn, I.M. Ryzhik, Tables of Integrals, Seris, and Products, fifth ed., Academic Press, New York, 1994] and [in: M. Abramowitz, I.A. Stegun (Eds.), Handbook of Mathematical Functions, Nath. Bureau of Standards, Washington, 1964]) and they have deduced that the odd terms in our Eqs. (19) and (23) should not be ignored. We thank the authors for their interest in our work and for their remarks. In the following, we will give the response to their two questions.

  17. A comparison of corrosion, tribocorrosion and electrochemical impedance properties of pure Ti and Ti6Al4V alloy treated by micro-arc oxidation process

    NASA Astrophysics Data System (ADS)

    Fazel, M.; Salimijazi, H. R.; Golozar, M. A.; Garsivaz jazi, M. R.

    2015-01-01

    In this paper, the micro-arc oxidation (MAO) coatings were performed on pure Ti and Ti6Al4V samples at 180 V. The results indicated that unlike the volcanic morphology of oxide layer on pure Ti, a cortex-like morphology with irregular vermiform slots was seen on MAO/Ti6Al4V sample. According to polarization curves, the corrosion resistance of untreated samples was significantly increased by MAO process. The electrochemical impedance spectroscopy analysis showed a lower capacitance of barrier layer (led to higher resistance) for MAO/Ti specimens. This indicates that corrosive ions diffusion throughout the oxide film would be more difficult resulted in a higher corrosion resistance. Tribocorrosion results illustrated that the potential of untreated samples was dropped sharply to very low negative values. However, the lower wear volume loss was achieved for Ti6Al4V alloy. SEM images of worn surfaces demonstrated the local detachment of oxide layer within the wear track of MAO/Ti sample. Conversely, no delamination was detected in MAO/Ti6Al4V and a mild abrasive wear was the dominant mechanism.

  18. Adsorption of boric acid on pure and humic acid coated am-Al(OH)3: A boron K-edge XANES study.

    PubMed

    Xu, Dani; Peak, Derek

    2007-02-01

    The fate and mobility of boric acid in the environment is largely controlled by adsorption reactions with soil organic matter and soil minerals to form surface complexes (Soil Sci Soc. Am. J. 1991, 55, 1582; Geochim. Cosmochim. Acta 2002, 67, 2551; Soil Sci. Soc. Am. J. 1995, 59, 405; Environ. Sci. Technol. 1995, 29, 302). In this study, boric acid adsorption on pure am-Al(OH)3 and 5% (w/w) humic acid (HA) coated am-Al(OH)3 were investigated both as a function of pH (4.5-11) and initial boric acid concentration (0-4.5 mmol L(-1)). Batch adsorption isotherm experiments were also conducted with samples exposed to atmospheric CO2 and anaerobic (N2) conditions to examine the effects of dissolved CO2 on boric acid adsorption. Boron (B) K-edge X-ray absorption near-edge structure (XANES) spectroscopy was used to investigate the coordination of boric acid adsorbed at mineral/water interfaces. The XANES spectra of boric acid adsorption samples showed that both trigonally and tetrahedrally coordinated B complexes were present on the mineral surface. Both macroscopic and spectroscopic experiments revealed that the combination of HA coating on am-Al(OH)3 and dissolved CO2 decreased boric acid adsorption compared to adsorption on pure am-Al(OH)3.

  19. Commercially pure titanium (cp-Ti) versus titanium alloy (Ti6Al4V) materials as bone anchored implants - Is one truly better than the other?

    PubMed

    Shah, Furqan A; Trobos, Margarita; Thomsen, Peter; Palmquist, Anders

    2016-05-01

    Commercially pure titanium (cp-Ti) and titanium alloys (typically Ti6Al4V) display excellent corrosion resistance and biocompatibility. Although the chemical composition and topography are considered important, the mechanical properties of the material and the loading conditions in the host have, conventionally, influenced material selection for different clinical applications: predominantly Ti6Al4V in orthopaedics while cp-Ti in dentistry. This paper attempts to address three important questions: (i) To what extent do the surface properties differ when cp-Ti and Ti6Al4V materials are manufactured with the same processing technique?, (ii) Does bone tissue respond differently to the two materials, and (iii) Do bacteria responsible for causing biomaterial-associated infections respond differently to the two materials? It is concluded that: (i) Machined cp-Ti and Ti6Al4V exhibit similar surface morphology, topography, phase composition and chemistry, (ii) Under experimental conditions, cp-Ti and Ti6Al4V demonstrate similar osseointegration and biomechanical anchorage, and (iii) Experiments in vitro fail to disclose differences between cp-Ti and Ti6Al4V to harbour Staphylococcus epidermidis growth. No clinical comparative studies exist which could determine if long-term, clinical differences exist between the two types of bulk materials. It is debatable whether cp-Ti or Ti6Al4V exhibit superiority over the other, and further comparative studies, particularly in a clinical setting, are required. PMID:26952502

  20. Commercially pure titanium (cp-Ti) versus titanium alloy (Ti6Al4V) materials as bone anchored implants - Is one truly better than the other?

    PubMed

    Shah, Furqan A; Trobos, Margarita; Thomsen, Peter; Palmquist, Anders

    2016-05-01

    Commercially pure titanium (cp-Ti) and titanium alloys (typically Ti6Al4V) display excellent corrosion resistance and biocompatibility. Although the chemical composition and topography are considered important, the mechanical properties of the material and the loading conditions in the host have, conventionally, influenced material selection for different clinical applications: predominantly Ti6Al4V in orthopaedics while cp-Ti in dentistry. This paper attempts to address three important questions: (i) To what extent do the surface properties differ when cp-Ti and Ti6Al4V materials are manufactured with the same processing technique?, (ii) Does bone tissue respond differently to the two materials, and (iii) Do bacteria responsible for causing biomaterial-associated infections respond differently to the two materials? It is concluded that: (i) Machined cp-Ti and Ti6Al4V exhibit similar surface morphology, topography, phase composition and chemistry, (ii) Under experimental conditions, cp-Ti and Ti6Al4V demonstrate similar osseointegration and biomechanical anchorage, and (iii) Experiments in vitro fail to disclose differences between cp-Ti and Ti6Al4V to harbour Staphylococcus epidermidis growth. No clinical comparative studies exist which could determine if long-term, clinical differences exist between the two types of bulk materials. It is debatable whether cp-Ti or Ti6Al4V exhibit superiority over the other, and further comparative studies, particularly in a clinical setting, are required.

  1. Comment on: "A theoretical model to explain the mechanism of light wave propagation through non-metallic nanowires" [Opt. Commun. 283 (2010) 4085

    NASA Astrophysics Data System (ADS)

    Moradi, Afshin

    2015-12-01

    In a recent article [R. P. Dwivedi, H.-I. Lee, O. Beom-Hoan, E.-H. Lee, Opt. Commun, 283 (2010) 4085], E.-H. Lee et al. studied the mechanism of light wave propagation through non-metallic nanowires of sub-diffraction dimension and presented the general expressions of the dispersions relations of TE and TM modes, respectively. Here we show that the system generally disallows the separation of the TE and TM modes, except for the case of modes with no angular dependence.

  2. Comparison of the deformation behaviour of commercially pure titanium and Ti-5Al-2.5Sn(wt.%) at 296 and 728 K

    NASA Astrophysics Data System (ADS)

    Li, H.; Mason, D. E.; Yang, Y.; Bieler, T. R.; Crimp, M. A.; Boehlert, C. J.

    2013-07-01

    The tension and tensile-creep deformation behaviours of a fully-α phase commercially pure (CP) Ti and a near-α Ti-5Al-2.5Sn(wt.%) alloy deformed in situ inside a scanning electron microscope were compared. Tensile tests were performed at 296 and 728 K, while tensile-creep tests were performed at 728 K. The yield stress of CP Ti decreased dramatically with increasing temperature. In contrast, temperature had much smaller effect on the yield stress of Ti-5Al-2.5Sn(wt.%). Electron backscattered diffraction was performed both before and after the deformation, and slip trace analysis was used to determine the active slip and twinning systems, as well as the associated global stress state Schmid factors. In tension tests of CP Ti, prismatic slip was the most likely slip system to be activated when the Schmid factor exceeded 0.4. Prismatic slip was observed over the largest Schmid factor range, indicating that the local stress tensor varies significantly from the global stress state of uniaxial tension. The basal slip activity in Ti-5Al-2.5Sn(wt.%) was observed in a larger faction of grains than in CP Ti. Pyramidal ⟨c + a⟩ slip was more prevalent in CP Ti. Although twinning was an active deformation mode in tension tests of the CP Ti, it was rare in Ti-5Al-2.5Sn(wt.%). During creep, dislocation slip was the primary apparent deformation mechanism in CP Ti, while evidence for dislocation slip was much less apparent in Ti-5Al-2.5Sn(wt.%), where grain boundary sliding was dominant. A robust statistical analysis was carried out to assess the significance of the comparative activity of the different slip systems under the variety of experimental conditions examined.

  3. Free-Form-Fabricated Commercially Pure Ti and Ti6Al4V Porous Scaffolds Support the Growth of Human Embryonic Stem Cell-Derived Mesodermal Progenitors

    PubMed Central

    de Peppo, G. M.; Palmquist, A.; Borchardt, P.; Lennerås, M.; Hyllner, J.; Snis, A.; Lausmaa, J.; Thomsen, P.; Karlsson, C.

    2012-01-01

    Commercially-pure titanium (cp-Ti) and the titanium-aluminum-vanadium alloy (Ti6Al4V) are widely used as reconstructive implants for skeletal engineering applications, due to their good mechanical properties, biocompatibility and ability to integrate with the surrounding bone. Electron beam melting technology (EBM) allows the fabrication of customized implants with tailored mechanical properties and high potential in the clinical practice. In order to augment the interaction with the biological tissue, stem cells have recently been combined with metallic scaffolds for skeletal engineering applications. We previously demonstrated that human embryonic stem cell-derived mesodermal progenitors (hES-MPs) hold a great potential to provide a homogeneous and unlimited supply of cells for bone engineering applications. This study demonstrates the effect of EBM-fabricated cp-Ti and Ti6Al4V porous scaffolds on hES-MPs behavior, in terms of cell attachment, growth and osteogenic differentiation. Displaying different chemical composition but similar surface properties, EBM-fabricated cp-Ti and Ti6Al4V scaffolds supported cell attachment and growth, and did not seem to alter the expression of genes involved in osteogenic differentiation and affect the alkaline phosphatase activity. In conclusion, interfacing hES-MPs to EBM-fabricated scaffolds may represent an interesting strategy for design of third-generation biomaterials, with the potential to promote implant integration in clinical conditions characterized by poor bone quality. PMID:22262956

  4. Effect of argon purity on mechanical properties, microstructure and fracture mode of commercially pure (cp) Ti and Ti-6Al-4V alloys for ceramometal dental prostheses.

    PubMed

    Bauer, José; Cella, Suelen; Pinto, Marcelo M; Filho, Leonardo E Rodrigues; Reis, Alessandra; Loguercio, Alessandro D

    2009-12-01

    Provision of an inert gas atmosphere with high-purity argon gas is recommended for preventing titanium castings from contamination although the effects of the level of argon purity on the mechanical properties and the clinical performance of Ti castings have not yet been investigated. The purpose of this study was to evaluate the effect of argon purity on the mechanical properties and microstructure of commercially pure (cp) Ti and Ti-6Al-4V alloys. The castings were made using either high-purity and/or industrial argon gas. The ultimate tensile strength (UTS), proportional limit (PL), elongation (EL) and microhardness (VHN) at different depths were evaluated. The microstructure of the alloys was also revealed and the fracture mode was analyzed by scanning electron microscopy. The data from the mechanical tests and hardness were subjected to a two-and three-way ANOVA and Tukey's test (alpha = 0.05). The mean values of mechanical properties were not affected by the argon gas purity. Higher UTS, PL and VHN, and lower EL were observed for Ti-6Al-4V. The microhardness was not influenced by the argon gas purity. The industrial argon gas can be used to cast cp Ti and Ti-6Al-4V.

  5. Comments on the papers recently published by M.M. Khandpekar et al.

    NASA Astrophysics Data System (ADS)

    Petrosyan, A. M.; Ghazaryan, V. V.; Fleck, M.

    2011-09-01

    It is argued that the existence of the new compounds of glycine recently reported by M.M. Khandpekar et al. (Optics Commun. 284(2011) 1583 and Optics Commun. 284(2011) 1578) is dubious. We argue that these compounds are not what the authors propose. In addition, two more similar cases are indicated.

  6. Properties of impurity-bearing ferrihydrite II: Insights into the surface structure and composition of pure, Al- and Si-bearing ferrihydrite from Zn(II) sorption experiments and Zn K-edge X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Cismasu, A. Cristina; Levard, Clément; Michel, F. Marc; Brown, Gordon E.

    2013-10-01

    Naturally occurring ferrihydrite often contains impurities such as Al and Si, which can impact its chemical reactivity with respect to metal(loid) adsorption and (in)organic or microbially induced reductive dissolution. However, the surface composition of impure ferrihydrites is not well constrained, and this hinders our understanding of the factors controlling the surface reactivity of these nanophases. In this study, we conducted Zn(II) adsorption experiments combined with Zn K-edge X-ray absorption spectroscopy measurements on pure ferrihydrite (Fh) and Al- or Si-bearing ferrihydrites containing 10 and 20 mol% Al or Si (referred to as 10AlFh, 20AlFh and 10SiFh, 20SiFh) to evaluate Zn(II) uptake in relation to Zn(II) speciation at their surfaces. Overall, Zn(II) uptake at the surface of AlFh is similar to that of pure Fh, and based on Zn K-edge EXAFS data, Zn(II) speciation at the surface of Fh and AlFh also appears similar. Binuclear bidentate IVZn-VIFe complexes (at ∼3.46 Å (2C[1]) and ∼3.25 Å (2C[2])) were identified at low Zn(II) surface coverages from Zn K-edge EXAFS fits. With increasing Zn(II) surface coverage, the number of second-neighbor Fe ions decreased, which was interpreted as indicating the formation of IVZn polymers at the ferrihydrite surface, and a deviation from Langmuir uptake behavior. Zn(II) uptake at the surface of SiFh samples was more significant than at Fh and AlFh surfaces, and was attributed to the formation of outer-sphere complexes (on average 24% of sorbed Zn). Although similar Zn-Fe/Zn distances were obtained for the Zn-sorbed SiFh samples, the number of Fe second neighbors was lower in comparison with Fh. The decrease in second-neighbor Fe is most pronounced for sample 20SiFh, suggesting that the amount of reactive surface Fe sites diminishes with increasing Si content. Although our EXAFS results shown here do not provide evidence for the existence of Zn-Al or Zn-Si complexes, their presence is not excluded for Zn-sorbed Al

  7. The mechanism of oxygen isotopic fractionation during fungal denitrification - A pure culture study

    NASA Astrophysics Data System (ADS)

    Wrage-Moennig, Nicole; Rohe, Lena; Anderson, Traute-Heidi; Braker, Gesche; Flessa, Heinz; Giesemann, Annette; Lewicka-Szczebak, Dominika; Well, Reinhard

    2014-05-01

    Nitrous oxide (N2O) from soil denitrification originates from bacteria and - to an unknown extent - also from fungi. During fungal denitrification, oxygen (O) exchange takes place between H2O and intermediates of the denitrification process as in bacterial exchange[1,2]. However, information about enzymes involved in fungal O exchanges and the associated fractionation effects is lacking. The objectives of this study were to estimate the O fractionation and O exchange during the fungal denitrifying steps using a conceptual model[2] adapted from concepts for bacterial denitrification[3], implementing controls of O exchange proposed by Aerssens, et al.[4] and using fractionation models by Snider et al.[5] Six different pure fungal cultures (five Hypocreales, one Sordariales) known to be capable of denitrification were incubated under anaerobic conditions, either with nitrite or nitrate. Gas samples were analyzed for N2O concentration and its isotopic signatures (SP, average δ15N, δ18O). To investigate O exchange, both treatments were also established with 18O-labelled water as a tracer in the medium. The Hypocreales strains showed O exchange mainly at NO2- reductase (Nir) with NO2- as electron acceptor and no additional O exchange at NO3- reductase (Nar) with NO3- as electron acceptor. The only Hypocreales species having higher O exchange with NO3- than with NO2- also showed O exchange at Nar. The Sordariales species tested seems capable of O exchange at NO reductase (Nor) additionally to O exchange at Nir with NO2-. The data will help to better interpret stable isotope values of N2O from soils. .[1] D. M. Kool, N. Wrage, O. Oenema, J. Dolfing, J. W. Van Groenigen. Oxygen exchange between (de)nitrification intermediates and H2O and its implications for source determination of NO?3- and N2O: a review. Rapid Commun. Mass Spec. 2007, 21, 3569. [2] L. Rohe, T.-H. Anderson, B. Braker, H. Flessa, A. Giesemann, N. Wrage-Mönnig, R. Well. Fungal Oxygen Exchange between

  8. Density functional study on size-dependent structures, stabilities, electronic and magnetic properties of Au(n)M (M = Al and Si, n = 1-9) clusters: comparison with pure gold clusters.

    PubMed

    Li, Yan-Fang; Mao, Ai-Jie; Li, Yang; Kuang, Xiao-Yu

    2012-07-01

    The density functional theory (DFT) method has been employed to systematically investigate the geometrical structures, relative stabilities, and electronic and magnetic properties of Au(n)M (M = Al and Si, n = 1-9) clusters for clarifying the effect of Al(Si) modulation on the gold nanostructures. Of all the clusters studied, the most stable configurations adopt a three-dimensional structure for Au(n)Al at n = 4-8 and Au(n)Si at n = 3-9, while for pure gold systems, no three-dimensional lowest energy structures are obtained. Through a careful analysis of the fragmentation energy, second-order difference of energy, HOMO-LUMO energy gap, and magnetic moment as a function of cluster size, an odd-even alternative phenomenon has been observed. The results show that the clusters with even-number valence electrons have a higher relative stability, but lower magnetic moments. Furthermore, Al(Si) doping is found to enhance the stabilities of gold frameworks. In addition, the charge analysis has been given to understand the different effects of individual doped atom on electronic properties and compared further.

  9. Twisted partially pure spinors

    NASA Astrophysics Data System (ADS)

    Herrera, Rafael; Tellez, Ivan

    2016-08-01

    Motivated by the relationship between orthogonal complex structures and pure spinors, we define twisted partially pure spinors in order to characterize spinorially subspaces of Euclidean space endowed with a complex structure.

  10. Purely lytic osteosarcoma

    SciTech Connect

    De Santos, L.A.; Eideken, B.

    1982-11-01

    The radiographic features of 42 purely lytic osteosarcomas are presented. Purely lytic osteosarcoma is identified as a lytic lesion of bone with no demonstrable osteoid matrix by conventional radiographic modalities. Purely lytic osteosarcoma represented 13.7% of a group of 305 osteosarcomas. The most common presentation was that of a lytic illdefined lesion with a moderate to large extraosseous mass component. Nine lesions presented with benign radiographic features. The differential diagnosis is outlined. The need for awareness of this type of presentation of osteosarcoma is stressed.

  11. Pure-quartic solitons

    PubMed Central

    Blanco-Redondo, Andrea; Martijn, de Sterke C.; Sipe, J.E.; Krauss, Thomas F.; Eggleton, Benjamin J.; Husko, Chad

    2016-01-01

    Temporal optical solitons have been the subject of intense research due to their intriguing physics and applications in ultrafast optics and supercontinuum generation. Conventional bright optical solitons result from the interaction of anomalous group-velocity dispersion and self-phase modulation. Here we experimentally demonstrate a class of bright soliton arising purely from the interaction of negative fourth-order dispersion and self-phase modulation, which can occur even for normal group-velocity dispersion. We provide experimental and numerical evidence of shape-preserving propagation and flat temporal phase for the fundamental pure-quartic soliton and periodically modulated propagation for the higher-order pure-quartic solitons. We derive the approximate shape of the fundamental pure-quartic soliton and discover that is surprisingly Gaussian, exhibiting excellent agreement with our experimental observations. Our discovery, enabled by precise dispersion engineering, could find applications in communications, frequency combs and ultrafast lasers. PMID:26822758

  12. Pure-quartic solitons.

    PubMed

    Blanco-Redondo, Andrea; de Sterke, C Martijn; Martijn, de Sterke C; Sipe, J E; Krauss, Thomas F; Eggleton, Benjamin J; Husko, Chad

    2016-01-01

    Temporal optical solitons have been the subject of intense research due to their intriguing physics and applications in ultrafast optics and supercontinuum generation. Conventional bright optical solitons result from the interaction of anomalous group-velocity dispersion and self-phase modulation. Here we experimentally demonstrate a class of bright soliton arising purely from the interaction of negative fourth-order dispersion and self-phase modulation, which can occur even for normal group-velocity dispersion. We provide experimental and numerical evidence of shape-preserving propagation and flat temporal phase for the fundamental pure-quartic soliton and periodically modulated propagation for the higher-order pure-quartic solitons. We derive the approximate shape of the fundamental pure-quartic soliton and discover that is surprisingly Gaussian, exhibiting excellent agreement with our experimental observations. Our discovery, enabled by precise dispersion engineering, could find applications in communications, frequency combs and ultrafast lasers. PMID:26822758

  13. Geomorphology: Pure and applied

    SciTech Connect

    Hart, M.G.

    1986-01-01

    The book summarizes the history of intellectual debate in geomorphology and describes modern developments both ''pure'' and ''applied.'' The history begins well before W.M. Davis and follows through to such debates as those concerned with the Pleistocene. Modern developments in pure geomorphology are cast in terms of chapters on form, process, materials, and methods analysis. The applied chapters concentrate on environmental hazards and resources, and their management.

  14. Pure shift NMR.

    PubMed

    Zangger, Klaus

    2015-04-01

    Although scalar-coupling provides important structural information, the resulting signal splittings significantly reduce the resolution of NMR spectra. Limited resolution is a particular problem in proton NMR experiments, resulting in part from the limited proton chemical shift range (∼10 ppm) but even more from the splittings due to scalar coupling to nearby protons. "Pure shift" NMR spectroscopy (also known as broadband homonuclear decoupling) has been developed for disentangling overlapped proton NMR spectra. The resulting spectra are considerably simplified as they consist of single lines, reminiscent of proton-decoupled C-13 spectra at natural abundance, with no multiplet structure. The different approaches to obtaining pure shift spectra are reviewed here and several applications presented. Pure shift spectra are especially useful for highly overlapped proton spectra, as found for example in reaction mixtures, natural products and biomacromolecules.

  15. Production of pure metals

    NASA Technical Reports Server (NTRS)

    Philipp, W. H.; Marsik, S. J.; May, C. E. (Inventor)

    1974-01-01

    A process for depositing elements by irradiating liquids is reported. Ultra pure elements are precipitated from aqueous solutions or suspensions of compounds. A solution of a salt of a metal to be prepared is irradiated, and the insoluble reaction product settles out. Some chemical compounds may also be prepared in this manner.

  16. Dahlbeck and Pure Ontology

    ERIC Educational Resources Information Center

    Mackenzie, Jim

    2016-01-01

    This article responds to Johan Dahlbeck's "Towards a pure ontology: Children's bodies and morality" ["Educational Philosophy and Theory," vol. 46 (1), 2014, pp. 8-23 (EJ1026561)]. His arguments from Nietzsche and Spinoza do not carry the weight he supposes, and the conclusions he draws from them about pedagogy would be…

  17. Purely Cortical Anaplastic Ependymoma

    PubMed Central

    Romero, Flávio Ramalho; Zanini, Marco Antônio; Ducati, Luis Gustavo; Vital, Roberto Bezerra; de Lima Neto, Newton Moreira; Gabarra, Roberto Colichio

    2012-01-01

    Ependymomas are glial tumors derived from ependymal cells lining the ventricles and the central canal of the spinal cord. It may occur outside the ventricular structures, representing the extraventicular form, or without any relationship of ventricular system, called ectopic ependymona. Less than fifteen cases of ectopic ependymomas were reported and less than five were anaplastic. We report a rare case of pure cortical ectopic anaplastic ependymoma. PMID:23119204

  18. Purely cortical anaplastic ependymoma.

    PubMed

    Romero, Flávio Ramalho; Zanini, Marco Antônio; Ducati, Luis Gustavo; Vital, Roberto Bezerra; de Lima Neto, Newton Moreira; Gabarra, Roberto Colichio

    2012-01-01

    Ependymomas are glial tumors derived from ependymal cells lining the ventricles and the central canal of the spinal cord. It may occur outside the ventricular structures, representing the extraventicular form, or without any relationship of ventricular system, called ectopic ependymona. Less than fifteen cases of ectopic ependymomas were reported and less than five were anaplastic. We report a rare case of pure cortical ectopic anaplastic ependymoma.

  19. Pure Lovelock Kasner metrics

    NASA Astrophysics Data System (ADS)

    Camanho, Xián O.; Dadhich, Naresh; Molina, Alfred

    2015-09-01

    We study pure Lovelock vacuum and perfect fluid equations for Kasner-type metrics. These equations correspond to a single Nth order Lovelock term in the action in d=2N+1,2N+2 dimensions, and they capture the relevant gravitational dynamics when aproaching the big-bang singularity within the Lovelock family of theories. Pure Lovelock gravity also bears out the general feature that vacuum in the critical odd dimension, d=2N+1, is kinematic, i.e. we may define an analogue Lovelock-Riemann tensor that vanishes in vacuum for d=2N+1, yet the Riemann curvature is non-zero. We completely classify isotropic and vacuum Kasner metrics for this class of theories in several isotropy types. The different families can be characterized by means of certain higher order 4th rank tensors. We also analyze in detail the space of vacuum solutions for five- and six dimensional pure Gauss-Bonnet theory. It possesses an interesting and illuminating geometric structure and symmetries that carry over to the general case. We also comment on a closely related family of exponential solutions and on the possibility of solutions with complex Kasner exponents. We show that the latter imply the existence of closed timelike curves in the geometry.

  20. Stable pure state quantum tomography from five orthonormal bases

    NASA Astrophysics Data System (ADS)

    Carmeli, Claudio; Heinosaari, Teiko; Kech, Michael; Schultz, Jussi; Toigo, Alessandro

    2016-08-01

    For any finite-dimensional Hilbert space, we construct explicitly five orthonormal bases such that the corresponding measurements allow for efficient tomography of an arbitrary pure quantum state. This means that such measurements can be used to distinguish an arbitrary pure state from any other state, pure or mixed, and the pure state can be reconstructed from the outcome distribution in a feasible way. The set of measurements we construct is independent of the unknown state, and therefore our results provide a fixed scheme for pure state tomography, as opposed to the adaptive (state-dependent) scheme proposed by Goyeneche et al. (Phys. Rev. Lett., 115 (2015) 090401). We show that our scheme is robust with respect to noise, in the sense that any measurement scheme which approximates these measurements well enough is equally suitable for pure state tomography. Finally, we present two convex programs which can be used to reconstruct the unknown pure state from the measurement outcome distributions.

  1. 7 CFR 917.8 - Pure grower or pure producer.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.8 Pure grower or pure producer. (a) For peaches,...

  2. 7 CFR 917.8 - Pure grower or pure producer.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.8 Pure grower or pure producer. (a) For peaches,...

  3. Viscosity of pure hydrocarbons

    SciTech Connect

    Knapstad, B.; Skjolsvik, P.A.; Oye, H.A.

    1989-01-01

    Accurate viscosity measurements have been performed on eight pure hydrocarbons at atmospheric pressure in the temperature range 20-150/sup 0/C, or up to approximately 20/sup 0/C below the boiling point of the hydrocarbon, by use of an absolute oscillating viscometer. The hydrocarbons are cyclohexane and benzene and the n-alkanes of hexane, heptane, octane, decane, dodecane, and tetradecane. The viscosities are described with a modified Arrhenius equation, and the deviation in fit is 0.12% or less. The accuracy is estimated to be 0.33-0.56%. The lowest viscosities are assumed to have the highest deviation. Literature data reported by Dymond and Young normally fit our viscosities within our estimated accuracy. Other literature viscosities tend to be higher than our results, especially for the n-alkanes.

  4. Active-Transient Liquid Phase (A-TLP) Bonding of Pure Aluminum Matrix Composite Reinforced with Short Alumina Fiber Using Al-12Si- xTi Foils as Active Interlayer

    NASA Astrophysics Data System (ADS)

    Zhang, Guifeng; Su, Wei; Suzumura, Akio

    2016-06-01

    To optimize both the interlayer composition design route and pressure for joining aluminum matrix composite reinforced with short alumina fiber (as-cast 30 vol pct Al2O3sf/Al), traditional transient liquid phase (TLP) bonding using Al-12Si and Cu interlayer and active-TLP (A-TLP) bonding using an active Ti-containing interlayer (Al-12Si- xTi, x = 0.1, 0.5, and 1 wt pct) under the same condition [883 K (610 °C) × 30 minutes × 1 or 0.015 MPa in flowing argon] were compared in terms of interfacial wettability, bond seam microstructure, shear strength, and fracture path. It was found that not only the Ti content but also the pressure are critical factors affecting interfacial wettability and bond seam microstructure. The improvement in wettability by adding Ti as an active element were confirmed by reduction of expulsion of liquid interlayer, elimination of interfacial gap, higher shear strength and favorable fracture path (partially through bond seam and the composite). Because of the incubation period for wetting, reducing the pressure after melting of the interlayer could further increase joint shear strength by thickening the remaining bond seam of solid-solution matrix and decreasing fraction of the in situ newly formed Al-Si-Ti IMC phase (short bar shape) within the bond seam. The maximum shear strength of 88.6 MPa (99 pct of the as-cast composite) was obtained by adding trace Ti content (0.5 Ti wt pct) addition and using low pressure (0.015 MPa). The results showed that suitable combination of Ti content and pressure pattern is required for improving both wettability and bond seam microstructure.

  5. Optical pure spin current injection in graphene

    NASA Astrophysics Data System (ADS)

    Rioux, Julien; Burkard, Guido

    2013-03-01

    Pure spin current injection by optical methods is investigated in single-layer and bilayer graphene within the tight-binding model, including bias and interlayer coupling effects. Interlayer coupling in bilayer graphene has a distinct qualitative effect on the polarization dependence of the spin current injection. In combination with interlayer coupling, which induces trigonal warping of the electronic bands, the bias voltage allows to control the warping at the Fermi surface. The resulting implications for the spin current injection are presented. Unlike the previously presented charge current injection [J. Rioux et al., PRB 83, 195406 (2011)], the effect presented here relies on a single monochromatic beam.

  6. "Pure" cutaneous histiocytosis-X.

    PubMed

    Wolfson, S L; Botero, F; Hurwitz, S; Pearson, H A

    1981-11-15

    The case histories of two young children who experienced skin rashes involving various areas of the body are reported. The diagnosis of pure cutaneous histiocytosis-X was established after extensive studies revealed no other organ involvement. The patients were treated with oral corticosteroids. Currently, both children are in good health, show no evidence of disease, and have been followed over a four-to-five-year period. Therapy with corticosteroids may not be indicated with pure cutaneous histiocytosis-X unless there is evidence of extracutaneous dissemination or rapid progression of the disease.

  7. Production of substantially pure fructose

    DOEpatents

    Hatcher, Herbert J.; Gallian, John J.; Leeper, Stephen A.

    1990-01-01

    A process is disclosed for the production of substantially pure fructose from sucrose-containing substrates. The process comprises converting the sucrose to levan and glucose, purifying the levan by membrane technology, hydrolyzing the levan to form fructose monomers, and recovering the fructose.

  8. Electron Acoustic Waves in Pure Ion Plasmas

    NASA Astrophysics Data System (ADS)

    Anderegg, F.; Affolter, M.; Driscoll, C. F.; O'Neil, T. M.; Valentini, F.

    2012-10-01

    Electron Acoustic Waves (EAWs) are the low-frequency branch of near-linear Langmuir (plasma) waves: the frequency is such that the complex dielectric function (Dr, Di) has Dr= 0; and ``flattening'' of f(v) near the wave phase velocity vph gives Di=0 and eliminates Landau damping. Here, we observe standing axisymmetric EAWs in a pure ion column.footnotetextF. Anderegg, et al., Phys. Rev. Lett. 102, 095001 (2009). At low excitation amplitudes, the EAWs have vph˜1.4 v, in close agreement with near-linear theory. At moderate excitation strengths, EAW waves are observed over a range of frequencies, with 1.3 v < vph< 2.1 v. Here, the final wave frequency may differ from the excitation frequency since the excitation modifies f (v); and recent theory analyzes frequency shifts from ``corners'' of a plateau at vph.footnotetextF. Valentini et al., arXiv:1206.3500v1. Large amplitude EAWs have strong phase-locked harmonic content, and experiments will be compared to same-geometry simulations, and to simulations of KEENfootnotetextB. Afeyan et al., Proc. Inertial Fusion Sci. and Applications 2003, A.N.S. Monterey (2004), p. 213. waves in HEDLP geometries.

  9. Pure Rotational Spectroscopy of Vinyl Mercaptan

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, Marie-Aline; Zingsheim, Oliver; Thorwirth, Sven; Müller, Holger S. P.; Lewen, Frank; Schlemmer, Stephan

    2014-06-01

    Vinyl mercaptan (ethenethiol, CH_2=CHSH) exists in the gas phase in two distinct rotameric forms, syn (planar) and anti (quasi-planar in the ground vibrational state). The microwave spectra of these two isomers were investigated previously, however not exceeding frequencies of about 65 GHz. In the present investigation, the pure rotational spectra of both species have been investigated at millimeter wavelengths. Vinyl mercaptan was produced in a radiofrequency discharge through a constant flow of ethanedithiol at low pressure. Both syn and anti rotamers were observed and new extensive sets of molecular parameters were obtained. Owing to its close structural relationship to vinyl alcohol and the astronomical abundance of complex sulfur-bearing molecules, vinyl mercaptan is a plausible candidate for future radio astronomical searches. M. Tanimoto et al. J. Mol. Spectrosc. 78, 95--105 & 106--119 (1979)

  10. Canonical Thermal Pure Quantum State

    NASA Astrophysics Data System (ADS)

    Sugiura, Sho; Shimizu, Akira

    2013-07-01

    A thermal equilibrium state of a quantum many-body system can be represented by a typical pure state, which we call a thermal pure quantum (TPQ) state. We construct the canonical TPQ state, which corresponds to the canonical ensemble of the conventional statistical mechanics. It is related to the microcanonical TPQ state, which corresponds to the microcanonical ensemble, by simple analytic transformations. Both TPQ states give identical thermodynamic results, if both ensembles do, in the thermodynamic limit. The TPQ states corresponding to other ensembles can also be constructed. We have thus established the TPQ formulation of statistical mechanics, according to which all quantities of statistical-mechanical interest are obtained from a single realization of any TPQ state. We also show that it has great advantages in practical applications. As an illustration, we study the spin-1/2 kagome Heisenberg antiferromagnet.

  11. Comments on recently published "L-threonine phthalate" and pure and doped "L-lysinium succinate" crystals

    NASA Astrophysics Data System (ADS)

    Petrosyan, A. M.

    2016-04-01

    It is shown that the recently published papers on "L-threonine phthalate" (Theras et al. (2015) [2]) and pure and doped "L-lysinium succinate" (Kalaivani et al. (2015) [11,16]) misidentified the targeted compounds.

  12. Synthesis of Enantiomerically Pure Anthracyclinones

    NASA Astrophysics Data System (ADS)

    Achmatowicz, Osman; Szechner, Barbara

    The anthracycline antibiotics are among the most important clinical drugs used in the treatment of human cancer. The search for new agents with improved therapeutic efficacy and reduced cardiotoxicity stimulated considerable efforts in the synthesis of new analogues. Since the biological activity of anthracyclines depends on their natural absolute configuration, various strategies for the synthesis of enantiomerically pure anthracyclinones (aglycones) have been developed. They comprise: resolution of racemic intermediate, incorporation of a chiral fragment derived from natural and non-natural chiral pools, asymmetric synthesis with the use of a chiral auxiliary or a chiral reagent, and enantioselective catalysis. Synthetic advances towards enantiopure anthracyclinones reported over the last 17 years are reviewed.

  13. Production of substantially pure fructose

    SciTech Connect

    Hatcher, H.J.; Gallian, J.J.; Leeper, S.A.

    1990-05-22

    This patent describes a process for the production of a substantially pure product containing greater than 60% fructose. It comprises: combining a sucrose-containing substrate with effective amounts of a levansucrase enzyme preparation to form levan and glucose; purifying the levan by at least one of the following purification methods: ultrafiltration, diafiltration, hyperfiltration, reverse osmosis, liquid--liquid partition, solvent extraction, chromatography, and precipitation; hydrolyzing the levan to form fructose substantially free of glucose and sucrose; and recovering the fructose by at least one of the following recovery methods: hyperfiltration, reverse osmosis, evaporation, drying, crystallization, and chromatography.

  14. Les accidents du travail dans le transport urbain en commun de la ville province de Kinshasa, République Démocratique du Congo: une étude transversale descriptive

    PubMed Central

    Wangata, Jemima; Elenge, Myriam; De Brouwer, Christophe

    2014-01-01

    Introduction Le transport en commun urbain constitue un secteur où les travailleurs sont très exposés aux accidents du travail. Cette étude visait une description épidémiologique des accidents du travail dans le secteur informel du transport en commun à Kinshasa en vue d'apporter les pistes d'amélioration de la sécurité des travailleurs dans cette activité. Méthodes Un questionnaire sur les accidents du travail, administré en Décembre 2012 a permis d'explorer les tendances significatives entre les accidents et leurs circonstances, leurs facteurs associés, leurs conséquences au sein d'une population des travailleurs (n = 472) du transport en commun à Kinshasa. Résultats Durant les 12 derniers précédant l’étude 76.5% des travailleurs ont connu au moins un accident du travail, 54,8% ont connu un arrêt d'au moins 1jour. Les accidents liés à la circulation routière étaient plus important suivis des chutes. Les facteurs ayant montré des différences significatives étaient le travail sous l'influence de l'alcool et le port des équipements de protection individuelle. Les plaies (46,3%) et les contusions (39,4%) étaient les lésions les plus courantes. Les membres supérieurs (51,3%) et inférieurs (30,7%) étaient les plus atteints. 76,6% des travailleurs ont assumé seuls leur prise en charge médicale. Conclusion L'incidence des accidents du travail dans ce secteur est très élevée. La mise en place d'une politique de prévention et gestion de différents facteurs associés ainsi qu'un système de déclaration d'accidents est nécessaire dans ce secteur. Les patrons ainsi que les politiques devraient veiller à une prise en charge médicale correcte pour des travailleurs accidentés. PMID:25667703

  15. 76 FR 69284 - Pure Magnesium From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... COMMISSION Pure Magnesium From China Determination On the basis of the record \\1\\ developed in the subject... order on pure magnesium from China would be likely to lead to continuation or recurrence of material... USITC Publication 4274 (October 2011), entitled Pure Magnesium from China: Investigation No....

  16. Split-Hopkinson Pressure Bar Tests on Pure Tantalum

    NASA Astrophysics Data System (ADS)

    Dick, Richard D.; Armstrong, Ronald W.

    1997-07-01

    Pure tantalum was loaded in compression by a split-Hopkinson pressure bar (SHPB) apparatus to strain rates from 450 to 6350 s-1. These stress-strain data were added to data collected previously to evaluate and improve the constitutive equations for tantalum(Armstrong, et al., 1997, Final report to the U.S. Army Research Laboratory, Aberdeen Proving Ground, MD.). In particular, the high strain rate data were compared to SHPB data of Armstrong, et al.(Armstrong, et al., 1997, Tantalum, Published by Minerals, Metals, and Mining Society, Warrendale, PA.) for commercially prepared tantalum. The main conclusions are: 1) the flow stress - log strain rate data agree well with the Zerilli - Armstrong constitutive model for pure tantalum, 2) uniform strain exponents computed for pure tantalum are significantly smaller than for commercial tantalum relating to the presence of impurities, 3) a plot of the uniform strain exponent versus log strain rate shows good agreement with the curve predicted by Zerilli and Armstrong at strain rates above 2000 s-1, and 4) the ductility of commercial tantalum is enhanced at high strain rates because of added dislocation generation.

  17. Mixtures of maximally entangled pure states

    NASA Astrophysics Data System (ADS)

    Flores, M. M.; Galapon, E. A.

    2016-09-01

    We study the conditions when mixtures of maximally entangled pure states remain entangled. We found that the resulting mixed state remains entangled when the number of entangled pure states to be mixed is less than or equal to the dimension of the pure states. For the latter case of mixing a number of pure states equal to their dimension, we found that the mixed state is entangled provided that the entangled pure states to be mixed are not equally weighted. We also found that one can restrict the set of pure states that one can mix from in order to ensure that the resulting mixed state is genuinely entangled. Also, we demonstrate how these results could be applied as a way to detect entanglement in mixtures of the entangled pure states with noise.

  18. Isomerically Pure Tetramethylrhodamine Voltage Reporters.

    PubMed

    Deal, Parker E; Kulkarni, Rishikesh U; Al-Abdullatif, Sarah H; Miller, Evan W

    2016-07-27

    We present the design, synthesis, and application of a new family of fluorescent voltage indicators based on isomerically pure tetramethylrhodamines. These new Rhodamine Voltage Reporters, or RhoVRs, use photoinduced electron transfer (PeT) as a trigger for voltage sensing, display excitation and emission profiles in the green to orange region of the visible spectrum, demonstrate high sensitivity to membrane potential changes (up to 47% ΔF/F per 100 mV), and employ a tertiary amide derived from sarcosine, which aids in membrane localization and simultaneously simplifies the synthetic route to the voltage sensors. The most sensitive of the RhoVR dyes, RhoVR 1, features a methoxy-substituted diethylaniline donor and phenylenevinylene molecular wire at the 5'-position of the rhodamine aryl ring, exhibits the highest voltage sensitivity to date for red-shifted PeT-based voltage sensors, and is compatible with simultaneous imaging alongside green fluorescent protein-based indicators. The discoveries that sarcosine-based tertiary amides in the context of molecular-wire voltage indicators prevent dye internalization and 5'-substituted voltage indicators exhibit improved voltage sensitivity should be broadly applicable to other types of PeT-based voltage-sensitive fluorophores. PMID:27428174

  19. Bringing Planctomycetes into pure culture

    PubMed Central

    Lage, Olga M.; Bondoso, Joana

    2012-01-01

    Planctomycetes have been known since the description of Planctomyces bekefii by Gimesi at the beginning of the twentieth century (1924), although the first axenic cultures were only obtained in the 1970s. Since then, 11 genera with 14 species have been validly named and five candidatus genera belonging to the anaerobic ammonium oxidation, anammox bacteria have also been discovered. However, Planctomycetes diversity is much broader than these numbers indicate, as shown by environmental molecular studies. In recent years, the authors have attempted to isolate and cultivate additional strains of Planctomycetes. This paper provides a summary of the isolation work that was carried out to obtain in pure culture Planctomycetes from several environmental sources. The following strains of planctomycetes have been successfully isolated: two freshwater strains from the sediments of an aquarium, which were described as a new genus and species, Aquisphaera giovannonii; several Rhodopirellula strains from the sediments of a water treatment recycling tank of a marine fish farm; and more than 140 planctomycetes from the biofilm community of macroalgae. This collection comprises several novel taxa that are being characterized and described. Improvements in the isolation methodology were made in order to optimize and enlarge the number of Planctomycetes isolated from the macroalgae. The existence of an intimate and an important relationship between planctomycetes and macroalgae reported before by molecular studies is therefore supported by culture-dependent methods. PMID:23335915

  20. Pure spin current transport in Alq3 by spin pumping

    NASA Astrophysics Data System (ADS)

    Jiang, Shengwei; Wang, Peng; Luan, Zhongzhi; Tao, Xinde; Ding, Haifeng; Wu, Di

    2015-03-01

    The use of organic semiconductors (OSCs) in spintronics has aroused considerable interests, owing to their much longer spin-relaxation times of OSCs than those of inorganic counterparts. The most studied example is the organic spin valve (OSV), in which magnetoresistance (MR) effect is frequently reported. However, studies on pure spin current injection and transport in OSCs are scarce. Recently, the pioneering work by Watanabe et al. demonstrated that pure spin current can be pumped into and propagates in semiconducting polymers. In the present work we extend the study to small molecule OSCs, and demonstrate that pure spin current can be injected into Alq3 from the adjacent magnetic insulator Y3Fe5O12 (YIG) by spin pumping. The pure spin current is detected by inverse spin Hall effect (ISHE) in Pd after propagation through Alq3. From the ISHE voltage VISHE as a function of the Alq3 thickness, the spin diffusion length is determined to be ~ 50 nm and does not depend on temperature. This result indicates the MR decrease as increasing temperature in OSVs is not due to the reduced spin diffusion length.

  1. Method of preparing pure fluorine gas

    DOEpatents

    Asprey, Larned B.

    1976-01-01

    A simple, inexpensive system for purifying and storing pure fluorine is described. The method utilizes alkali metal-nickel fluorides to absorb tank fluorine by forming nickel complex salts and leaving the gaseous impurities which are pumped away. The complex nickel fluoride is then heated to evolve back pure gaseous fluorine.

  2. ALS Association

    MedlinePlus

    ... toward a world without ALS! Walk to Defeat ALS® Walk to Defeat ALS® draws people of all ... We need your help. I Will Advocate National ALS Registry The National ALS Registry is a congressionally ...

  3. Thermodynamic modeling of Pt-Al and Pd-Al

    NASA Astrophysics Data System (ADS)

    Carr, Derek

    2011-03-01

    Pure platinum and pure palladium are too soft for typical jewelry applications. Adding small amounts of other metals can significantly increase their performance. However, international hallmarking standards require the alloys to be 95% pure by weight. How does one achieve significant improvements in performance adding only small amounts (5 wt-%) of other metals? Significant improvements are possible even with small additions if precipitate hardening can be induced. Using a combination of first-principles, cluster expansion, and Monte Carlo modeling, we have identified new Pt-rich/Pd-rich phases in Pt-Al and Pd-Al that should be useful in precipitate hardening. Thermodynamical modeling indicates that the phases are experimentally feasible (not kinetically inhibited).

  4. The Temperature Dependent Enthalpy of Vaporization of Pure Substances

    NASA Astrophysics Data System (ADS)

    Tian, Jianxiang

    Recently the universal behavior of the temperature dependent enthalpy of vaporization along with the whole liquid-vapor coexistence curve at equilibrium is described and explained by Roman et al.5 The work (called RWVM relation) succeeds in the combination of the linear relation near the triple point and the renormalization group theory result near the critical point. For the convenience of chemical designs and engineering applications, we report its b values yielding the minimum average absolute deviation (AAD) for 74 pure substances from the NIST web-book and compare the results with other correlations. We find that with an adapted b value, the RWVM relation predicts the data of 47 pure substances with an AAD less than 0.0093, with six more than 0.02 and all less than 0.03 except quantum fluid hydrogen, that is clearly better than other correlations. For most pure substances, b covers the range from 0 to 1. Only one negative value stands for the quantum fluid helium because of its enthalpy of vaporization being experimentally not a monotonic function of the temperature in the range near the triple point.

  5. Quantifying the coherence of pure quantum states

    NASA Astrophysics Data System (ADS)

    Chen, Jianxin; Grogan, Shane; Johnston, Nathaniel; Li, Chi-Kwong; Plosker, Sarah

    2016-10-01

    In recent years, several measures have been proposed for characterizing the coherence of a given quantum state. We derive several results that illuminate how these measures behave when restricted to pure states. Notably, we present an explicit characterization of the closest incoherent state to a given pure state under the trace distance measure of coherence. We then use this result to show that the states maximizing the trace distance of coherence are exactly the maximally coherent states. We define the trace distance of entanglement and show that it coincides with the trace distance of coherence for pure states. Finally, we give an alternate proof to a recent result that the ℓ1 measure of coherence of a pure state is never smaller than its relative entropy of coherence.

  6. Dark fermentation on biohydrogen production: Pure culture.

    PubMed

    Lee, Duu-Jong; Show, Kuan-Yeow; Su, Ay

    2011-09-01

    Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of literature reports on the pure hydrogen-producers under anaerobic environment. Challenges and perspective of biohydrogen production with pure cultures are also outlined.

  7. Rehabilitation of pure alexia: A review

    PubMed Central

    Starrfelt, Randi; Ólafsdóttir, Rannveig Rós; Arendt, Ida-Marie

    2013-01-01

    Acquired reading problems caused by brain injury (alexia) are common, either as a part of an aphasic syndrome, or as an isolated symptom. In pure alexia, reading is impaired while other language functions, including writing, are spared. Being in many ways a simple syndrome, one would think that pure alexia was an easy target for rehabilitation efforts. We review the literature on rehabilitation of pure alexia from 1990 to the present, and find that patients differ widely on several dimensions, such as alexia severity and associated deficits. Many patients reported to have pure alexia in the reviewed studies, have associated deficits such as agraphia or aphasia and thus do not strictly conform to the diagnosis. Few studies report clear and generalisable effects of training, none report control data, and in many cases the reported findings are not supported by statistics. We can, however, tentatively conclude that Multiple Oral Re-reading techniques may have some effect in mild pure alexia where diminished reading speed is the main problem, while Tacile-Kinesthetic training may improve letter identification in more severe cases of alexia. There is, however, still a great need for well-designed and controlled studies of rehabilitation of pure alexia. PMID:23808895

  8. Macromol. Rapid Commun. 12/2016.

    PubMed

    Saito, Yusuke; Nakata, Norio; Ishii, Akihiko

    2016-06-01

    Back Cover: Highly isospecific polymerization of silyl-protected ω-alkenols, using a combination of [OSSO]-type bis(phenolato) dichloro zirconium(IV) complex and dMAO as the precatalyst and the activator, respectively, is established. This method represents the first example for a stereoselective polymerization of polar functional α-olefins ([mmmm] > 95%). Subsequently, the obtained terminal siloxy-substituted isotactic polymer could be readily transformed by a macromolecular desilylation/acetylation reaction sequence to afford the corresponding terminal acetyl-enriched polymer. Further details can be found in the article by Y. Saito, N. Nakata,* and A. Ishii* on page 969. PMID:27307083

  9. Interfacial oxidations of pure titanium and titanium alloys with investments.

    PubMed

    Ban, S; Watanabe, T; Mizutani, N; Fukui, H; Hasegawa, J; Nakamura, H

    2000-12-01

    External oxides of a commercially pure titanium (cpTi), Ti6Al4V alloy, and an experimental beta-type titanium alloy (Ti 53.4 wt%, Nb 29 wt%, Ta 13 wt%, and Zr 4.6 wt%) were characterized after heating to 600, 900, 1150, and 1400 degrees C in contact with three types of investments (alumina cement, magnesia cement, and phosphate-bonded) in air. XRD studies demonstrated that MgO, Li2TiO3 and/or Li2Ti3O7 were formed through reactions with the metal and the constituents in the magnesia cement-investment after heating to 900, 1150, and 1400 degrees C. Except for these conditions, TiO2 (rutile) was only formed on cpTi. For titanium alloys, the other components apart from Ti also formed simple and complex oxides such as Al2O3 and Al2TiO5 on Ti6Al4V, and Zr0.25Ti0.75Nb2O7 on the beta-type titanium alloy. However, no oxides containing V or Ta were formed. These results suggest that the constituents of titanium alloys reacted with the investment oxides and atmospheric oxygen to form external oxides due to the free energy of oxide formation and the concentration of each element on the metal surface.

  10. Comparing the Thermodynamic Behaviour of Al(1)+ZrO2(s) to Al(1)+Al2O3(s)

    NASA Technical Reports Server (NTRS)

    Copland, Evan

    2004-01-01

    In an effort to better determine the thermodynamic properties of Al(g) and Al2O(g). the vapor in equilibrium with Al(l)+ZrO2(s) was compared to the vapor in equilibrium with Al(l)+Al2O3(s) over temperature range 1197-to-1509K. The comparison was made directly by Knudsen effusion-cell mass spectrometry with an instrument configured for a multiple effusion-cell vapor source (multi-cell KEMS). Second law enthalpies of vaporization of Al(g) and Al2O(g) together with activity measurements show that Al(l)+ZrO2(s) is thermodynamically equivalent to Al(l)+Al2O3(s), indicating Al(l) remained pure and Al2O3(s) was present in the ZrO2-cell. Subsequent observation of the Al(l)/ZrO2 and vapor/ZrO2 interfaces revealed a thin Al2O3-layer had formed, separating the ZrO2-cell from Al(l) and Al(g)+Al2O(g), effectively transforming it into an Al2O3 effusion-cell. This behavior agrees with recent observations made for Beta-NiAl(Pt) alloys measured in ZrO2 effusion-cell.

  11. Revival of pure titanium for dynamically loaded porous implants using additive manufacturing.

    PubMed

    Wauthle, Ruben; Ahmadi, Seyed Mohammad; Amin Yavari, Saber; Mulier, Michiel; Zadpoor, Amir Abbas; Weinans, Harrie; Van Humbeeck, Jan; Kruth, Jean-Pierre; Schrooten, Jan

    2015-09-01

    Additive manufacturing techniques are getting more and more established as reliable methods for producing porous metal implants thanks to the almost full geometrical and mechanical control of the designed porous biomaterial. Today, Ti6Al4V ELI is still the most widely used material for porous implants, and none or little interest goes to pure titanium for use in orthopedic or load-bearing implants. Given the special mechanical behavior of cellular structures and the material properties inherent to the additive manufacturing of metals, the aim of this study is to investigate the properties of selective laser melted pure unalloyed titanium porous structures. Therefore, the static and dynamic compressive properties of pure titanium structures are determined and compared to previously reported results for identical structures made from Ti6Al4V ELI and tantalum. The results show that porous Ti6Al4V ELI still remains the strongest material for statically loaded applications, whereas pure titanium has a mechanical behavior similar to tantalum and is the material of choice for cyclically loaded porous implants. These findings are considered to be important for future implant developments since it announces a potential revival of the use of pure titanium for additively manufactured porous implants.

  12. Revival of pure titanium for dynamically loaded porous implants using additive manufacturing.

    PubMed

    Wauthle, Ruben; Ahmadi, Seyed Mohammad; Amin Yavari, Saber; Mulier, Michiel; Zadpoor, Amir Abbas; Weinans, Harrie; Van Humbeeck, Jan; Kruth, Jean-Pierre; Schrooten, Jan

    2015-09-01

    Additive manufacturing techniques are getting more and more established as reliable methods for producing porous metal implants thanks to the almost full geometrical and mechanical control of the designed porous biomaterial. Today, Ti6Al4V ELI is still the most widely used material for porous implants, and none or little interest goes to pure titanium for use in orthopedic or load-bearing implants. Given the special mechanical behavior of cellular structures and the material properties inherent to the additive manufacturing of metals, the aim of this study is to investigate the properties of selective laser melted pure unalloyed titanium porous structures. Therefore, the static and dynamic compressive properties of pure titanium structures are determined and compared to previously reported results for identical structures made from Ti6Al4V ELI and tantalum. The results show that porous Ti6Al4V ELI still remains the strongest material for statically loaded applications, whereas pure titanium has a mechanical behavior similar to tantalum and is the material of choice for cyclically loaded porous implants. These findings are considered to be important for future implant developments since it announces a potential revival of the use of pure titanium for additively manufactured porous implants. PMID:26046272

  13. Engineering arbitrary pure and mixed quantum states

    SciTech Connect

    Pechen, Alexander

    2011-10-15

    Controlled manipulation by atomic- and molecular-scale quantum systems has attracted a lot of research attention in recent years. A fundamental problem is to provide deterministic methods for controlled engineering of arbitrary quantum states. This work proposes a deterministic method for engineering arbitrary pure and mixed states of a wide class of quantum systems. The method exploits a special combination of incoherent and coherent controls (incoherent and coherent radiation) and has two properties which are specifically important for manipulating by quantum systems: it realizes the strongest possible degree of their state control, complete density matrix controllability, meaning the ability to steer arbitrary pure and mixed initial states into any desired pure or mixed final state, and it is all-to-one, such that each particular control transfers all initial system states into one target state.

  14. ALS - resources

    MedlinePlus

    Resources - ALS ... The following organizations are good resources for information on amyotrophic lateral sclerosis : Muscular Dystrophy Association -- mda.org/disease/amyotrophic-lateral-sclerosis National Amyotrophic Lateral Sclerosis (ALS) Registry -- ...

  15. Pure neuritic leprosy: Current status and relevance.

    PubMed

    Rao, P Narasimha; Suneetha, Sujai

    2016-01-01

    Pure neuritic leprosy has always been an enigma due to its clinical and management ambiguities. Although only the Indian Association of Leprologist's classification recognizes 'pure neuritic leprosy' as a distinct sub group of leprosy, cases nonetheless are reported from various countries of Asia, Africa, South America and Europe, indicating its global relevance. It is important to maintain pure neuritic leprosy as a subgroup as it constitutes a good percentage of leprosy cases reported from India, which contributes to more than half of global leprosy numbers. Unfortunately, a high proportion of these patients present with Grade 2 disability at the time of initial reporting itself due to the early nerve involvement. Although skin lesions are absent by definition, when skin biopsies were performed from the skin along the distribution of the affected nerve, a proportion of patients demonstrated leprosy pathology, revealing sub-clinical skin involvement. In addition on follow-up, skin lesions are noted to develop in up to 20% of pure neuritic leprosy cases, indicating its progression to manifest cutaneous disease. Over the decades, the confirmation of diagnosis of pure neuritic leprosy has been subjective, however, with the arrival and use of high-resolution ultrasonography (HRUS) for nerve imaging, we have a tool not only to objectively measure and record the nerve thickening but also to assess the morphological alterations in the nerve including echo texture, fascicular pattern and vascularity. Management of pure neuritic leprosy requires multidrug therapy along with appropriate dose of systemic corticosteroids, for both acute and silent neuritis. Measures for pain relief, self-care of limbs and physiotherapy are important to prevent as well as manage disabilities in this group of patients. PMID:27088926

  16. Pure Apraxia of Speech - A Case Report -

    PubMed Central

    Kang, Young Ae; Yun, Sang Jin

    2011-01-01

    Apraxia of speech (AOS) is the impairment of motor programming. However, the exact nature of this deficit remains unclear. In particular, AOS without other speech-language deficit is called pure AOS, but it is very rare. When diagnosing AOS, the characteristic of articulation is considered a crucial criterion, which has been proposed for differentiating AOS from phonological and dysarthric disorders. The present study reports on pure AOS in a 37-year-old right-handed male after a left insular, front, temporal infarction. This report may be useful for further AOS study and diagnosis in the clinical setting. PMID:22506197

  17. BRST and the pure spinor formalism

    SciTech Connect

    Garcia, J. Antonio

    2008-03-06

    The aim of this talk is to show the relation between the standard BRST approach of the GS superstring with the quantization technics used in the pure spinor approach to superstring. To that end we will use the Batalin-Fradkin-Tyutin (BFT) conversion program of second class constraints to first class constraints in the GS superstring using light cone coordinates. By applying this systematic procedure we were able to obtain a gauge system that is equivalent to the recent model proposed in [1] to relate the GS superstring to the pure spinor formalism.

  18. Pure agraphia after deep left hemisphere haematoma.

    PubMed Central

    Croisile, B; Laurent, B; Michel, D; Trillet, M

    1990-01-01

    Pure agraphia is reported following haematoma in the left centrum semiovale sparing both parietal and frontal cortices. There was total inability to produce graphemes in the absence of limb apraxia. The lesion is assumed to have prevented linguistic and graphemic systems from gaining access to the frontal motor programme. Images PMID:2324759

  19. A fatal case of pure metaphyseal chondroblastoma.

    PubMed

    Binesh, Fariba; Moghadam, Reza Nafisi; Abrisham, Jalil

    2013-08-23

    The chondroblastoma (CB) is a rare cartilaginous tumour; it represents less than 1% of all bone tumours. It is mostly localised at the level of the epiphysis of long bones. We report a fatal case of pure metaphyseal CB of the tibia in a 9-year-old boy whose pulmonary metastases developed soon after operative therapy of the primary tumour.

  20. Temporal Ventriloquism in a Purely Temporal Context

    ERIC Educational Resources Information Center

    Hartcher-O'Brien, Jessica; Alais, David

    2011-01-01

    This study examines how audiovisual signals are combined in time for a temporal analogue of the ventriloquist effect in a purely temporal context, that is, no spatial grounding of signals or other spatial facilitation. Observers were presented with two successive intervals, each defined by a 1250-ms tone, and indicated in which interval a brief…

  1. Pure progressive amnesia: An atypical amnestic syndrome?

    PubMed

    Barbeau, Emmanuel J; Didic, Mira; Felician, Olivier; Tramoni, Eve; Guedj, Eric; Ceccaldi, Mathieu; Poncet, Michel

    2006-12-01

    We report on M.S., an 83-year-old patient with isolated pure progressive amnesia. This rare, recently identified, form of amnesia has been described in elderly patients. Neuropathological studies suggest that this syndrome is an atypical clinical presentation of Alzheimer's disease. The aim of our study was to characterize the neuropsychological pattern of pure progressive amnesia in comparison with other amnestic syndromes and memory dissociations reported in the literature. Our results indicate that pure progressive amnesia is characterized by a highly unusual dissociation in the realm of memory, with severe deficits on tests based on recognition and recall of verbal and visual single items, contrasting with relatively preserved anterograde autobiographical and spatial memory and normal recall of complex material such as stories. These findings suggest that memory for single items could depend on an independent system. One hypothesis is that M.S.'s unusual memory profile results from relative dysfunction of the ventral medial temporal lobe pathway. An alternative explanation implicates cognitive reserve. Further studies are required in order to progress on this matter. In any case, pure progressive amnesia is a clinical syndrome that may provide further insight into the organization of declarative memory.

  2. A fatal case of pure metaphyseal chondroblastoma.

    PubMed

    Binesh, Fariba; Moghadam, Reza Nafisi; Abrisham, Jalil

    2013-01-01

    The chondroblastoma (CB) is a rare cartilaginous tumour; it represents less than 1% of all bone tumours. It is mostly localised at the level of the epiphysis of long bones. We report a fatal case of pure metaphyseal CB of the tibia in a 9-year-old boy whose pulmonary metastases developed soon after operative therapy of the primary tumour. PMID:23975916

  3. Implicit Reading in Chinese Pure Alexia

    ERIC Educational Resources Information Center

    Shan, Chunlei; Zhu, Renjing; Xu, Mingwei; Luo, Benyan; Weng, Xuchu

    2010-01-01

    A number of recent studies have shown that some patients with pure alexia display evidence of implicit access to lexical and semantic information about words that they cannot read explicitly. This phenomenon has not been investigated systematically in Chinese patients. We report here a case study of a Chinese patient who met the criteria for pure…

  4. Pure science and the problem of progress.

    PubMed

    Douglas, Heather

    2014-06-01

    How should we understand scientific progress? Kuhn famously discussed science as its own internally driven venture, structured by paradigms. He also famously had a problem describing progress in science, as problem-solving ability failed to provide a clear rubric across paradigm change--paradigm changes tossed out problems as well as solving them. I argue here that much of Kuhn's inability to articulate a clear view of scientific progress stems from his focus on pure science and a neglect of applied science. I trace the history of the distinction between pure and applied science, showing how the distinction came about, the rhetorical uses to which the distinction has been put, and how pure science came to be both more valued by scientists and philosophers. I argue that the distinction between pure and applied science does not stand up to philosophical scrutiny, and that once we relinquish it, we can provide Kuhn with a clear sense of scientific progress. It is not one, though, that will ultimately prove acceptable. For that, societal evaluations of scientific work are needed.

  5. A Pure Theory of Lifelong Learning.

    ERIC Educational Resources Information Center

    Hatton, Michael J.

    Charles Tiebout's Pure Theory of Local Expenditures serves as a helpful framework in examining the emergence of the learning society, communications technologies, freer trade, and the effects these will have on the educational infrastructure. Tiebout argued that the failure of market-type systems of public good at the central government level does…

  6. Exploring the simplest purely baryonic decay processes

    NASA Astrophysics Data System (ADS)

    Geng, C. Q.; Hsiao, Y. K.; Rodrigues, Eduardo

    2016-07-01

    Though not considered in general, purely baryonic decays could shed light on the puzzle of the baryon number asymmetry in the universe by means of a better understanding of the baryonic nature of our matter world. As such, they constitute a yet unexplored class of decay processes worth investigating. We propose to search for purely baryonic decay processes at the LHCb experiment. No such type of decay has ever been observed. In particular, we concentrate on the decay Λb0→p p ¯n , which is the simplest purely baryonic decay mode, with solely spin-1 /2 baryons involved. We predict its decay branching ratio to be B (Λb0→p p ¯ n )=(2. 0-0.2+0.3)×10-6 , which is sufficiently large to make the decay mode accessible to LHCb. Our study can be extended to other purely baryonic decays such as Λb0→p p ¯ Λ , Λb0→Λ p ¯ Λ , and Λb0→Λ Λ ¯Λ , as well as to similar decays of antitriplet b baryons such as Ξb0 ,-.

  7. Nanorheology of adsorbed polymer chains immersed in pure solvent.

    PubMed

    Lapique, Fabrice; Montfort, Jean Pierre; Derail, Christophe

    2015-06-01

    Long linear chains of polybutadiene are adsorbed on the two surfaces of a surface force apparatus and immersed in pure tetradecane. The hydrodynamic force was measured by drainage experiments and by frequency sweeps at constant distances. We related the hydrodynamic thickness to the chain dimension. The complex modulus encompasses the shear modulus and, at distances lower than the hydrodynamic thickness, a compression modulus. The compression term was related to the static force which appears when the two adsorbed layers are overlapped. The complex shear modulus was interpreted by a two-components hydrodynamic model proposed by P. Sens et al. We first complemented the theoretical model. Then, our experimental data fit the proposed viscoelastic expressions in the entire range of distances. The storage modulus is supposed to be affected by a residue of free chains and by the dispersion of the loop lengths. PMID:26087919

  8. Creation of mixed beam from alloy target and couple of pure targets with laser

    SciTech Connect

    Ikeda, Shunsuke Sekine, Megumi; Romanelli, Mark; Cinquegrani, David; Kumaki, Masafumi; Fuwa, Yasuhiro; Munemoto, Naoya; Horioka, Kazuhiko; Kanesue, Takeshi; Okamura, Masahiro; Jin, Qianyu

    2014-02-15

    To create mixed species ion beam with laser pulses, we investigated charge state distributions of plasma formed from both Al-Fe alloy targets and pure Al and Fe targets placed close together. With two targets, we observed that the two kinds of atoms were mixed when the interval of two laser pulses was large enough (40 μs). On the other hand, when the interval was 0.0 μs, we observed fewer Fe ions and they did not mix well with the Al ions. The two species were mixed well in the plasma from the alloy target. Furthermore, we observed that specific charge states of Fe ions increased. From the results, it was determined that we can use two pure targets to mix two species whose difference of the drift velocity is large. On the other hand, we must use an alloy target when the drift velocities of the species are close.

  9. Strengthening of Al and Al-Mg alloy wires by melt inoculation with Al/MgB2 nanocomposite

    NASA Astrophysics Data System (ADS)

    Florián-Algarín, David; Marrero, Raúl; Padilla, Alexandra; Suárez, Oscar Marcelo

    2015-12-01

    This study hinges on the feasibility of strengthening Al and Al-Mg wires by adding Al nanocomposite pellets containing MgB2 nanoparticles into the melt upon fabrication. These MgB2 nanoparticles were obtained by fragmentation using a high-energy ball mill, and were, afterward, mechanically alloyed with pure aluminum. The resulting MgB2/Al nanocomposite pellets were sintered at 260°C to be subsequently added into molten aluminum and an Al-Mg alloy melt. Cold rolling intercalated with stepwise annealing allowed the fabrication of 1 mm diameter wires with a final area reduction of 96%. Mechanical and physical properties of the treated wire specimens were compared to those of similarly processed pure aluminum wire. The ultimate tensile strength of the treated wires increased approximately double fold with respect to untreated wires at the expense of some loss in electrical conductivity.

  10. A Novel Bonding Method of Pure Aluminum and SUS304 Stainless Steel Using Barrel Nitriding

    NASA Astrophysics Data System (ADS)

    Kong, Jung Hyun; Okumiya, Masahiro; Tsunekawa, Yoshiki; Yun, Ky Youl; Kim, Sang Gweon; Yoshida, Masashi

    2014-09-01

    A great deal of research is being carried out on welding or bonding methods between iron and aluminum. However, it is not so easy to make Fe-Al bonding materials with both high strength and light weight. Recently, a new nitriding process has been proposed to produce aluminum nitride on an aluminum surface using a barrel. This study proposes a new concept in the production of a multilayer which has an AlN and Fe-Al intermetallic compound layer between the aluminum and steel using a barrel nitriding process. The bonding process was carried out from 893 K to 913 K (620 °C to 640 °C) for 18, 25.2, and 36 ks with Al2O3 powder and Al-Mg alloy powder. After the process, an aluminum nitride (AlN) layer and a Fe-Al intermetallic compound (Fe2Al5.4) layer were formed at the interface between the pure aluminum and SUS304 austenitic stainless steel. The thicknesses of the AlN layer and the intermetallic compound layer increased with increasing treatment temperature and time. The maximum hardnesses of the AlN layer and Fe2Al5.4 layers were found to be 377HV and 910HV, respectively, after barrel nitriding at 893 K (620 °C) for 18 ks.

  11. Heat engine driven by purely quantum information.

    PubMed

    Park, Jung Jun; Kim, Kang-Hwan; Sagawa, Takahiro; Kim, Sang Wook

    2013-12-01

    The key question of this Letter is whether work can be extracted from a heat engine by using purely quantum mechanical information. If the answer is yes, what is its mathematical formula? First, by using a bipartite memory we show that the work extractable from a heat engine is bounded not only by the free energy change and the sum of the entropy change of an individual memory but also by the change of quantum mutual information contained inside the memory. We then find that the engine can be driven by purely quantum information, expressed as the so-called quantum discord, forming a part of the quantum mutual information. To confirm it, as a physical example we present the Szilard engine containing a diatomic molecule with a semipermeable wall.

  12. Pure field theories and MACSYMA algorithms

    NASA Technical Reports Server (NTRS)

    Ament, W. S.

    1977-01-01

    A pure field theory attempts to describe physical phenomena through singularity-free solutions of field equations resulting from an action principle. The physics goes into forming the action principle and interpreting specific results. Algorithms for the intervening mathematical steps are sketched. Vacuum general relativity is a pure field theory, serving as model and providing checks for generalizations. The fields of general relativity are the 10 components of a symmetric Riemannian metric tensor; those of the Einstein-Straus generalization are the 16 components of a nonsymmetric. Algebraic properties are exploited in top level MACSYMA commands toward performing some of the algorithms of that generalization. The light cone for the theory as left by Einstein and Straus is found and simplifications of that theory are discussed.

  13. Symmetries of Type N Pure Radiation Fields

    NASA Astrophysics Data System (ADS)

    Ahsan, Zafar; Ali, Musavvir

    2015-05-01

    The geometrical symmetries corresponding to the continuous groups of collineations and motions generated by a null vector l are considered. These symmetries have been translated into the language of Newman-Penrose formalism for pure radiation (PR) type N fields. It is seen that for such fields, conformal, special conformal and homothetic motions degenerate to motion. The concept of free curvature, matter curvature and matter affine collineations have been discussed and the conditions under which PR type N fields admit such collineations have been obtained. Moreover, it is shown that the projective collineation degenerate to matter affine, special projective, conformal, special conformal, null geodesic and special null geodesic collineations. It is also seen that type N pure radiation fields admit Maxwell collineation along the propagation vector l.

  14. Grip for fatigue testing pure aluminium

    NASA Astrophysics Data System (ADS)

    Lehmann, P.; Yuan, G. S.; Hartwig, K. T.

    A simple method of clamping pure aluminium for fatigue tests at cryogenic temperatures is described. Easily machined cylindrical specimens are aligned and held firmly by collet grips that counteract sample shrinkage during cooldown. Specimens are quickly mounted and removed after testing without distortion or thermal treatment 99.999% aluminium, aluminium alloys and copper were gripped successfully through tens of thousands of fully reversed tension-compression cycles at 295, 77 and 4.2 K.

  15. Pure connection action principle for general relativity.

    PubMed

    Krasnov, Kirill

    2011-06-24

    It has already been known for two decades that general relativity can be reformulated as a certain gauge theory, so that the only dynamical field is an SO(3) connection and the spacetime metric appears as a derived object. However, no simple action principle realizing these ideas has been available. A new elegant action principle for such a "pure connection" formulation of GR is described.

  16. Stable freestanding thin films of pure water

    SciTech Connect

    Weon, B. M.; Je, J. H.; Hwu, Y.; Margaritondo, G.

    2008-03-10

    Obtaining water microstructures is very difficult because of low viscosity and high surface tension. We produced stable freestanding thin films of pure water by x-ray bombardment of small liquid volumes in capillary tubes. A detailed characterization with phase-contrast radiology demonstrated a lifetime beyond 1 h with no chemical stabilizer for micron-thickness films with half-millimeter-level diameter. This can be attributed to the interplay of two x-ray effects: water evaporation and surface charging.

  17. On constructing purely affine theories with matter

    NASA Astrophysics Data System (ADS)

    Cervantes-Cota, Jorge L.; Liebscher, D.-E.

    2016-08-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schrödinger's purely affine theory (Schrödinger in Space-time structure. Cambridge UP, Cambridge, 1950), where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  18. Graphical calculus for Gaussian pure states

    SciTech Connect

    Menicucci, Nicolas C.; Flammia, Steven T.; Loock, Peter van

    2011-04-15

    We provide a unified graphical calculus for all Gaussian pure states, including graph transformation rules for all local and semilocal Gaussian unitary operations, as well as local quadrature measurements. We then use this graphical calculus to analyze continuous-variable (CV) cluster states, the essential resource for one-way quantum computing with CV systems. Current graphical approaches to CV cluster states are only valid in the unphysical limit of infinite squeezing, and the associated graph transformation rules only apply when the initial and final states are of this form. Our formalism applies to all Gaussian pure states and subsumes these rules in a natural way. In addition, the term 'CV graph state' currently has several inequivalent definitions in use. Using this formalism we provide a single unifying definition that encompasses all of them. We provide many examples of how the formalism may be used in the context of CV cluster states: defining the 'closest' CV cluster state to a given Gaussian pure state and quantifying the error in the approximation due to finite squeezing; analyzing the optimality of certain methods of generating CV cluster states; drawing connections between this graphical formalism and bosonic Hamiltonians with Gaussian ground states, including those useful for CV one-way quantum computing; and deriving a graphical measure of bipartite entanglement for certain classes of CV cluster states. We mention other possible applications of this formalism and conclude with a brief note on fault tolerance in CV one-way quantum computing.

  19. Al-based metal matrix composites reinforced with nanocrystalline Al-Ti-Ni particles

    NASA Astrophysics Data System (ADS)

    Scudino, S.; Ali, F.; Surreddi, K. B.; Prashanth, K. G.; Sakaliyska, M.; Eckert, J.

    2010-07-01

    Al-based metal matrix composites containing different volume fractions of nanocrystalline Al70Ti20Ni10 reinforcing particles have been produced by powder metallurgy and the effect of the volume fraction of reinforcement on the mechanical properties of the composites has been studied. Room temperature compression tests reveal a considerable improvement of the mechanical properties as compared to pure Aluminum. The compressive strength increases from 155 MPa for pure Al to about 200 and 240 MPa for the samples with 20 and 40 vol.% of reinforcement, respectively, while retaining appreciable plastic deformation with a fracture strain ranging between 43 and 28 %.

  20. Oscillatory surface relaxations in Ni, Al, and their ordered alloys

    SciTech Connect

    Chen, S.P.; Voter, A.F.; Srolovitz, D.J.

    1986-09-15

    Results from simulations of Ni, Al, Ni/sub 3/Al, and NiAl show long-range, oscillatory surface relaxations that decay exponentially into the bulk. Pure fcc Ni and Al have oscillation periods that are close to the nearest-neighbor distance, independent of crystal face. This is shown to be due to surface smoothing and steric effects. In Ni/sub 3/Al and NiAl, the surface planes are rippled, with the Ni-Ni and Al-Al interlayer spacings oscillating 180/sup 0/ out of phase. Very good agreement between our results and experimentally measured atomic relaxations is obtained.

  1. Augmenting The HST Pure Parallel Observations

    NASA Astrophysics Data System (ADS)

    Patterson, Alan; Soutchkova, G.; Workman, W.

    2012-05-01

    Pure Parallel (PP) programs, designated GO/PAR, are a subgroup of General Observer (GO) programs. PP execute simultaneously with prime GO observations to which they are "attached". The PP observations can be performed with ACS/WFC, WFC3/UVIS or WFC3/IR and can be attached only to GO visits in which the instruments are either COS or STIS. The current HST Parallel Observation Processing System (POPS) was introduced after the Servicing Mission 4. It increased the HST productivity by 10% in terms of the utilization of HST prime orbits and was highly appreciated by the HST observers, allowing them to design efficient, multi-orbit survey projects for collecting large amounts of data on identifiable targets. The results of the WFC3 Infrared Spectroscopic Parallel Survey (WISP), Hubble Infrared Pure Parallel Imaging Extragalactic Survey (HIPPIES), and The Brightest-of-Reionizing Galaxies Pure Parallel Survey (BoRG) exemplify this benefit. In Cycle 19, however, the full advantage of GO/PARs came under risk. Whereas each of the previous cycles provided over one million seconds of exposure time for PP, in Cycle 19 that number reduced to 680,000 seconds. This dramatic decline occurred because of fundamental changes in the construction of COS prime observations. To preserve the science output of PP, the PP Working Group was tasked to find a way to recover the lost time and maximize the total time available for PP observing. The solution was to expand the definition of a PP opportunity to allow PP exposures to span one or more primary exposure readouts. So starting in HST Cycle 20, PP opportunities will no longer be limited to GO visits with a single uninterrupted exposure in an orbit. The resulting enhancements in HST Cycle 20 to the PP opportunity identification and matching process are expected to restore the PP time to previously achieved and possibly even greater levels.

  2. chemf: A purely functional chemistry toolkit

    PubMed Central

    2012-01-01

    Background Although programming in a type-safe and referentially transparent style offers several advantages over working with mutable data structures and side effects, this style of programming has not seen much use in chemistry-related software. Since functional programming languages were designed with referential transparency in mind, these languages offer a lot of support when writing immutable data structures and side-effects free code. We therefore started implementing our own toolkit based on the above programming paradigms in a modern, versatile programming language. Results We present our initial results with functional programming in chemistry by first describing an immutable data structure for molecular graphs together with a couple of simple algorithms to calculate basic molecular properties before writing a complete SMILES parser in accordance with the OpenSMILES specification. Along the way we show how to deal with input validation, error handling, bulk operations, and parallelization in a purely functional way. At the end we also analyze and improve our algorithms and data structures in terms of performance and compare it to existing toolkits both object-oriented and purely functional. All code was written in Scala, a modern multi-paradigm programming language with a strong support for functional programming and a highly sophisticated type system. Conclusions We have successfully made the first important steps towards a purely functional chemistry toolkit. The data structures and algorithms presented in this article perform well while at the same time they can be safely used in parallelized applications, such as computer aided drug design experiments, without further adjustments. This stands in contrast to existing object-oriented toolkits where thread safety of data structures and algorithms is a deliberate design decision that can be hard to implement. Finally, the level of type-safety achieved by Scala highly increased the reliability of our code

  3. Are all maximally entangled states pure?

    NASA Astrophysics Data System (ADS)

    Cavalcanti, D.; Brandão, F. G. S. L.; Terra Cunha, M. O.

    2005-10-01

    We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of the monogamy of entanglement: we establish the polygamy of entanglement, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.

  4. Electrostatic Precipitation in Nearly Pure Gaseous Nitrogen

    NASA Technical Reports Server (NTRS)

    Buhler, Charles; Calle, Carlos; Clements, Sid; Cox, Bobby; Ritz, Mindy

    2008-01-01

    Electrostatic precipitation was performed in a nearly pure gaseous nitrogen system as a possible remedy for black dust contaminant from high pressure 6000 psi lines at the NASA Kennedy Space Center. The results of a prototype electrostatic precipitator that was built and tested using nitrogen gas at standard atmospheric pressures is presented. High voltage pulsed waveforms are generated using a rotating spark gap system at 30 Hz. A unique dust delivery system utilizing the Venturi effect was devised that supplies a given amount of dust per unit time for testing purposes.

  5. Preparation of a pure molecular quantum gas.

    PubMed

    Herbig, Jens; Kraemer, Tobias; Mark, Michael; Weber, Tino; Chin, Cheng; Nägerl, Hanns-Christoph; Grimm, Rudolf

    2003-09-12

    An ultracold molecular quantum gas is created by application of a magnetic field sweep across a Feshbach resonance to a Bose-Einstein condensate of cesium atoms. The ability to separate the molecules from the atoms permits direct imaging of the pure molecular sample. Magnetic levitation enables study of the dynamics of the ensemble on extended time scales. We measured ultralow expansion energies in the range of a few nanokelvin for a sample of 3000 molecules. Our observations are consistent with the presence of a macroscopic molecular matter wave. PMID:12934014

  6. Synthesis of highly phase pure BSCCO superconductors

    DOEpatents

    Dorris, S.E.; Poeppel, R.B.; Prorok, B.C.; Lanagan, M.T.; Maroni, V.A.

    1995-11-21

    An article and method of manufacture (Bi, Pb)-Sr-Ca-Cu-O superconductor are disclosed. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor. 5 figs.

  7. Synthesis of highly phase pure BSCCO superconductors

    DOEpatents

    Dorris, Stephen E.; Poeppel, Roger B.; Prorok, Barton C.; Lanagan, Michael T.; Maroni, Victor A.

    1995-01-01

    An article and method of manufacture of (Bi, Pb)-Sr-Ca-Cu-O superconductor. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor.

  8. Femtosecond pulses propagation through pure water

    NASA Astrophysics Data System (ADS)

    Naveira, Lucas; Sokolov, Alexei; Byeon, Joong-Hyeok; Kattawar, George

    2007-10-01

    Recently, considerable attention has been dedicated to the field of optical precursors, which can possibly be applied to long-distance underwater communications. Input beam intensities have been carefully adjusted to keep experiments in the linear regime, and some experiments have shown violation of the Beer-Lambert law. We are presently carrying out experiments using femtosecond laser pulses propagating through pure water strictly in the linear regime to study this interesting and important behavior. We are also employing several new and innovative schemes to more clearly define the phenomena.

  9. Purely cubic action for string field theory

    NASA Technical Reports Server (NTRS)

    Horowitz, G. T.; Lykken, J.; Rohm, R.; Strominger, A.

    1986-01-01

    It is shown that Witten's (1986) open-bosonic-string field-theory action and a closed-string analog can be written as a purely cubic interaction term. The conventional form of the action arises by expansion around particular solutions of the classical equations of motion. The explicit background dependence of the conventional action via the Becchi-Rouet-Stora-Tyutin operator is eliminated in the cubic formulation. A closed-form expression is found for the full nonlinear gauge-transformation law.

  10. Towards chirality-pure carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zhang, Yani; Zheng, Lianxi

    2010-10-01

    Current as-grown single-walled carbon nanotubes vary in diameter and chirality, which results in variations in their electronic and optical properties. Two approaches have been intensively studied to obtain chirality-pure nanotube structures and thus uniform properties for advanced applications. The first approach involves the post-synthesis separation according to the nanotubes' chiral vectors (n, m), and the second one involves direct synthes of carbon nanotubes with the same (n, m). This paper reviews the efforts along these two directions, with emphasis on the most recent progress of post-synthesis separation and the perspectives of controllable synthesis.

  11. Are all maximally entangled states pure?

    SciTech Connect

    Cavalcanti, D.; Brandao, F.G.S.L.; Terra Cunha, M.O.

    2005-10-15

    We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of the monogamy of entanglement: we establish the polygamy of entanglement, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.

  12. Cold-Sprayed Nanostructured Pure Cobalt Coatings

    NASA Astrophysics Data System (ADS)

    Cavaliere, P.; Perrone, A.; Silvello, A.

    2016-08-01

    Cold-sprayed pure cobalt coatings were deposited on carbon-steel substrate. Submicrometer particles for spraying were produced via cryomilling. Deposits were produced using different processing conditions (gas temperature and pressure, nozzle-to-substrate distance) to evaluate the resulting variations in grain size dimension, microhardness, adhesion strength, and porosity. The coating mechanical properties improved greatly with higher temperature and carrying-gas pressure. The coating microstructure was analyzed as a function of spraying condition by transmission electron microscopy (TEM) observations, revealing many different microstructural features for coatings experiencing low or high strain rates during deposition.

  13. Pure seminoma: A review and update

    PubMed Central

    2011-01-01

    Pure seminoma is a rare pathology of the young adult, often discovered in the early stages. Its prognosis is generally excellent and many therapeutic options are available, especially in stage I tumors. High cure rates can be achieved in several ways: standard treatment with radiotherapy is challenged by surveillance and chemotherapy. Toxicity issues and the patients' preferences should be considered when management decisions are made. This paper describes firstly the management of primary seminoma and its nodal involvement and, secondly, the various therapeutic options according to stage. PMID:21819630

  14. Pure phase decoherence in a ring geometry

    SciTech Connect

    Zhu, Z.; Aharony, A.; Entin-Wohlman, O.; Stamp, P. C. E.

    2010-06-15

    We study the dynamics of pure phase decoherence for a particle hopping around an N-site ring, coupled both to a spin bath and to an Aharonov-Bohm flux which threads the ring. Analytic results are found for the dynamics of the influence functional and of the reduced density matrix of the particle, both for initial single wave-packet states, and for states split initially into two separate wave packets moving at different velocities. We also give results for the dynamics of the current as a function of time.

  15. Non-chemically Pure Magnetites Produced from Thermal Decomposition of Ankerites

    NASA Astrophysics Data System (ADS)

    Jiménez López, C.; Romanek, C.; Rodríguez-Navarro, A.; Pérez-González, T.; Rodríguez Navarro, C.

    2008-12-01

    It has been claimed that chemically pure magnetites (Fe3O4) can be obtained from thermal decomposition of (Fe, Mg, Ca)CO3 (Golden et al., 2004). Such an observation is critical, since it opens the possibility of an inorganic way of formation of the magnetites found on Martian meteorite ALH84001. Such a chemical purity is one of the parameters used, so far, to recognize bacterial origin of natural magnetites (Thomas-Keptra et al., 2001), since it has been demonstrated that biologically-controlled magnetites are chemically pure (Bazylinski and Frankel, 2004) . However, while Golden et al. (2004) obtained pure magnetite from an almost pure precursor, the ankerite cores in ALH84001 in which magnetites are embedded are far from being chemically pure, since they contain considerable amounts of Ca and Mg (Kopp and Humayun, 2003). In this study we have performed several experiments to analyze the chemical purity of magnetites produced by thermal decomposition of four ankerite samples sinthetized in the laboratory, and containing different amounts of Ca, Fe and Mg. Such a thermal decomposition was achieved by two procedures: (1) by heating the samples at 470°C under CO2 pressure and (2) by decomposing the ankerite "in situ" under the TEM (Transmission electron Microscopy) electron beam. Magnetite produced by the first procedure was analyzed by XRD to determine whether or not the resulting solid was a mixture of oxides or rather a solid solution of (Ca, Fe and Mg)oxide. Magnetites formed by the two methods were studied by High Resolution TEM. The chemical composition of about 20 crystals of each experiment was analyzed by EDAX. Under our experimental conditions, ankerites decomposed in magnetite crystals of about 5 nanometers in size. Magentite crystals arranged to keep the morphology of the precursor. Our results confirm that any of these magnetites is chemically pure, but rather, each one of them is a solid solution of Ca and Mg. Therefore, chemically pure magnetites

  16. Nanoporous Au: an unsupported pure gold catalyst?

    SciTech Connect

    Wittstock, A; Neumann, B; Schaefer, A; Dumbuya, K; Kuebel, C; Biener, M; Zielasek, V; Steinrueck, H; Gottfried, M; Biener, J; Hamza, A; B?umer, M

    2008-09-04

    The unique properties of gold especially in low temperature CO oxidation have been ascribed to a combination of various effects. In particular, particle sizes below a few nm and specific particle-support interactions have been shown to play important roles. On the contrary, recent reports revealed that monolithic nanoporous gold (npAu) prepared by leaching a less noble metal, such as Ag, out of the corresponding alloy can also exhibit remarkably high catalytic activity for CO oxidation, even though no support is present. Therefore, it was claimed to be a pure and unsupported gold catalyst. We investigated npAu with respect to its morphology, surface composition and catalytic properties. In particular, we studied the reaction kinetics for low temperature CO oxidation in detail taking mass transport limitation due to the porous structure of the material into account. Our results reveal that Ag, even if removed almost completely from the bulk, segregates to the surface resulting in surface concentrations of up to 10 at%. Our data suggest that this Ag plays a significant role in activation of molecular oxygen. Therefore, npAu should be considered as a bimetallic catalyst rather than a pure Au catalyst.

  17. LHC Signals of Pure Gravity Mediation

    NASA Astrophysics Data System (ADS)

    Feldstein, Brian

    2013-05-01

    Evidence is mounting that natural supersymmetry at the weak scale is not realized in nature. This evidence comes from collider searches, a lack of new flavor changing neutral current effects, and now also the size of the measured Higgs mass. On the other hand, string theory suggests that supersymmetry might be present at some energy scale, and gauge coupling unification and dark matter imply that that energy scale may be relatively low. The simplest model to address all of these hints is arguably "pure gravity mediation", in which the scalar superpartner masses are taken to be perhaps 100 TeV, with gauginos automatically acquiring loop factor suppressed masses of order TeV. The gauginos might then be the only superpartners accessible to the LHC. Unification and LSP dark matter are maintained (with a wino LSP) at the cost of a 10-5 or 10-6 fine tuning. Here I will discuss the structure and LHC phenomenology of pure gravity mediation.

  18. Light Higgsinos in pure gravity mediation

    NASA Astrophysics Data System (ADS)

    Evans, Jason L.; Ibe, Masahiro; Olive, Keith A.; Yanagida, Tsutomu T.

    2015-03-01

    Pure gravity mediation, with two free parameters, is a minimalistic approach to supergravity models, yet it is capable of incorporating radiative electroweak symmetry breaking, a Higgs mass in agreement with the experimental measurement, without violating any phenomenological constraints. The model may also contain a viable dark matter candidate in the form of a wino. Here, we extend the minimal model by allowing the μ term to be a free parameter equivalent to allowing the two Higgs soft masses, m1 and m2, to differ from other scalar masses, which are set by the gravitino mass. In particular, we examine the region of parameter space where μ ≪m3 /2, in which case the Higgsino becomes the lightest supersymmetric particle and a dark matter candidate. We also consider a generalization of pure gravity mediation that incorporates a Peccei-Quinn symmetry which determines the μ term dynamically. In this case we show that the dark matter may either be in the form of an axion and/or a neutralino and that the lightest supersymmetric particle may be either a wino, bino, or Higgsino.

  19. Cosmic Shear - with ACS Pure Parallel Observations

    NASA Astrophysics Data System (ADS)

    Ratnatunga, Kavan

    2002-07-01

    The ACS, with greater sensitivity and sky coverage, will extend our ability to measure the weak gravitational lensing of galaxy images caused by the large scale distribution of dark matter. We propose to use the ACS in pure parallel {non- proprietary} mode, following the guidelines of the ACS Default Pure Parallel Program. Using the HST Medium Deep Survey WFPC2 database we have measured cosmic shear at arc-min angular scales. The MDS image parameters, in particular the galaxy orientations and axis ratios, are such that any residual corrections due to errors in the PSF or jitter are much smaller than the measured signal. This situation is in stark contrast with ground-based observations. We have also developed a statistical analysis procedure to derive unbiased estimates of cosmic shear from a large number of fields, each of which has a very small number of galaxies. We have therefore set the stage for measurements with the ACS at fainter apparent magnitudes and smaller, 10 arc-second scales corresponding to larger cosmological distances. We will adapt existing MDS WFPC2 maximum likelihood galaxy image analysis algorithms to work with the ACS. The analysis would also yield an online database similar to that in archive.stsci.edu/mds/

  20. Time Evolution of Pure Gravitational Waves

    NASA Astrophysics Data System (ADS)

    Miyama, S. M.

    1981-03-01

    Numerical solutions to the Einstein equations in the case of pure gravitational waves are given. The system is assumed to be axially symmetric and non-rotating. The time symmetric initial data and the conformally flat initial data are obtained by solving the constraint equations at t=0. The time evolution of these initial data depends strongly on the initial amplitude of the gravitational waves. In the case of the low initial amplitude, waves only disperse to null infinity. By comparing the initial gravitational energy with the total energy loss through an r=constant surface, it is concluded that the Newman-Penrose method and the Gibbon-Hawking method are the most desirable for measuring the energy flux of gravitational radiation numerically. In the case that the initial ratio of the spatial extent of the gravitational waves to the Schwarzschild radius (M/2) is smaller than about 300, the waves collapse by themselves, leading to formation of a black hole. The analytic solutions of the linearized Einstein equations for the pure gravitational waves are also shown.

  1. Wear behavior of Al-Al{sub 3}Ti composite manufactured by a centrifugal method

    SciTech Connect

    Watanabe, Yoshimi; Yamanaka, Noboru; Fukui, Yasuyoshi

    1999-12-01

    The purpose of the present study was to develop a wear-resistant, light Al-Al{sub 3}Ti composite material. An Al-Al{sub 3}Ti composite specimen was machined from a thick-walled tube of Al-Al{sub 3}Ti functionally graded material (FGM) manufactured by the centrifugal method from a commercial ingot of Al-5 mass% Ti master alloy. The alloy was heated to a temperature where solid Al{sub 3}Ti particles resided in a liquid Al matrix, and then the centrifugal method was carried out. Al{sub 3}Ti particles in a commercial alloy ingot exist as platelets, and this shape was maintained through the casting. Three kinds of wear specimens were prepared, taking into account the morphology of the Al{sub 3}Ti particles in the thick-walled FGM tube; the Al{sub 3}Ti particles were arranged with their platelet planes nearly normal to the radial direction as a result of the applied centrifugal force. The wear resistance of the Al-Al{sub 3}Ti composite was significantly higher than that of pure Al. Wear-resistance anisotropy and dissolution of the Al{sub 3}Ti into the Al matrix at the near-surface region, around 100 {micro}m in depth, were also observed. The mechanism of the supersaturated-layer formation and the origin of the anisotropic wear resistance are discussed.

  2. Mechanisms of elevated-temperature deformation in the B2 aluminides NiAl and CoAl

    NASA Technical Reports Server (NTRS)

    Yaney, D. L.; Nix, W. D.

    1988-01-01

    A strain rate change technique, developed previously for distinguishing between pure-metal and alloy-type creep behavior, was used to study the elevated-temperature deformation behavior of the intermetallic compounds NiAl and CoAl. Tests on NiAl were conducted at temperatures between 1100 and 1300 K while tests on CoAl were performed at temperatures ranging from 1200 to 1400 K. NiAl exhibits pure-metal type behavior over the entire temperature range studied. CoAl, however, undergoes a transition from pure-metal to alloy-type deformation behavior as the temperature is decreased from 1400 to 1200 K. Slip appears to be inherently more difficult in CoAl than in NiAl, with lattice friction effects limiting the mobility of dislocations at a much higher tmeperature in CoAl than in NiAl. The superior strength of CoAl at elevated temperatures may, therefore, be related to a greater lattice friction strengthening effect in CoAl than in NiAl.

  3. Updated analytical solutions of continuity equation for electron beams precipitation - I. Pure collisional and pure ohmic energy losses

    NASA Astrophysics Data System (ADS)

    Dobranskis, R. R.; Zharkova, V. V.

    2015-10-01

    We present updated analytical solutions of continuity equations for power-law beam electrons precipitating in (a) purely collisional losses and (b) purely ohmic losses. The solutions of continuity equation (CE) normalized on electron density presented in Dobranskis & Zharkova are found by method of characteristics eliminating a mistake in the density characteristic pointed out by Emslie et al. The corrected electron beam differential densities (DD) for collisions are shown to have energy spectra with the index of -(γ + 1)/2, coinciding with the one derived from the inverse problem solution by Brown, while being lower by 1/2 than the index of -γ/2 obtained from CE for electron flux. This leads to a decrease of the index of mean electron spectra from -(γ - 2.5) (CE for flux) to -(γ - 2.0) (CE for electron density). The similar method is applied to CE for electrons precipitating in electric field induced by the beam itself. For the first time, the electron energy spectra are calculated for both constant and variable electric fields by using CE for electron density. We derive electron DD for precipitating electrons (moving towards the photosphere, μ = +1) and `returning' electrons (moving towards the corona, μ = -1). The indices of DD energy spectra are reduced from -γ - 1 (CE for flux) to -γ (CE for electron density). While the index of mean electron spectra is increased by 0.5, from -γ + 0.5 (CE for flux) to -γ + 1(CE for electron density). Hard X-ray intensities are also calculated for relativistic cross-section for the updated differential spectra revealing closer resemblance to numerical Fokker-Planck (FP) solutions.

  4. Anomalous rectification in a purely electronic memristor

    NASA Astrophysics Data System (ADS)

    Wang, Jingrui; Pan, Ruobing; Cao, Hongtao; Wang, Yang; Liang, Lingyan; Zhang, Hongliang; Gao, Junhua; Zhuge, Fei

    2016-10-01

    An anomalous rectification was observed in a purely electronic memristive device Ti/ZnO/Pt. It could be due to (1) an Ohmic or quasi-Ohmic contact at the ZnO/Pt interface and (2) a Schottky contact at the Ti/ZnO interface. The Ohmic contact originates from the reduction of ZnO occurring in the whole film instead of only at the Ti/ZnO interface. The Schottky contact may come from moisture adsorbed in the nanoporous ZnO. The conduction in the electroformed device is controlled by the carrier trapping/detrapping of the trap sites, inducing a poor rectification and high nonlinearity. Furthermore, a complementary resistive switching was achieved.

  5. Bipedal nanowalker by pure physical mechanisms.

    PubMed

    Cheng, Juan; Sreelatha, Sarangapani; Hou, Ruizheng; Efremov, Artem; Liu, Ruchuan; van der Maarel, Johan R C; Wang, Zhisong

    2012-12-01

    Artificial nanowalkers are inspired by biomolecular counterparts from living cells, but remain far from comparable to the latter in design principles. The walkers reported to date mostly rely on chemical mechanisms to gain a direction; they all produce chemical wastes. Here we report a light-powered DNA bipedal walker based on a design principle derived from cellular walkers. The walker has two identical feet and the track has equal binding sites; yet the walker gains a direction by pure physical mechanisms that autonomously amplify an intrasite asymmetry into a ratchet effect. The nanowalker is free of any chemical waste. It has a distinct thermodynamic feature that it possesses the same equilibrium before and after operation, but generates a truly nonequilibrium distribution during operation. The demonstrated design principle exploits mechanical effects and is adaptable for use in other nanomachines.

  6. Pure White Cell Aplasia and Necrotizing Myositis

    PubMed Central

    Kim, Peter Geon; Suh, Joome; Adelman, Max W.; Oduro, Kwadwo; Williams, Erik; Brunner, Andrew M.; Kuter, David J.

    2016-01-01

    Pure white cell aplasia (PWCA) is a rare hematologic disorder characterized by the absence of neutrophil lineages in the bone marrow with intact megakaryopoiesis and erythropoiesis. PWCA has been associated with autoimmune, drug-induced, and viral exposures. Here, we report a case of a 74-year-old female who presented with severe proximal weakness without pain and was found to have PWCA with nonspecific inflammatory necrotizing myositis and acute liver injury on biopsies. These findings were associated with a recent course of azithromycin and her daily use of a statin. Myositis improved on prednisone but PWCA persisted. With intravenous immunoglobulin and granulocyte-colony stimulating factor therapies, her symptoms and neutrophil counts improved and were sustained for months. PMID:27073704

  7. Fock expansion of multimode pure Gaussian states

    SciTech Connect

    Cariolaro, Gianfranco; Pierobon, Gianfranco

    2015-12-15

    The Fock expansion of multimode pure Gaussian states is derived starting from their representation as displaced and squeezed multimode vacuum states. The approach is new and appears to be simpler and more general than previous ones starting from the phase-space representation given by the characteristic or Wigner function. Fock expansion is performed in terms of easily evaluable two-variable Hermite–Kampé de Fériet polynomials. A relatively simple and compact expression for the joint statistical distribution of the photon numbers in the different modes is obtained. In particular, this result enables one to give a simple characterization of separable and entangled states, as shown for two-mode and three-mode Gaussian states.

  8. Pure Varus Injury to the Knee Joint.

    PubMed

    Yoo, Jae Ho; Lee, Jung Ha; Chang, Chong Bum

    2015-06-01

    A 30-year-old male was involved in a car accident. Radiographs revealed a depressed marginal fracture of the medial tibial plateau and an avulsion fracture of the fibular head. Magnetic resonance imaging showed avulsion fracture of Gerdy's tubercle, injury to the posterior cruciate ligament (PCL), posterior horn of the medial meniscus, and the attachments of the lateral collateral ligament and the biceps femoris tendon. The depressed fracture of the medial tibial plateau was elevated and stabilized using a cannulated screw and washer. The injured lateral and posterolateral corner (PLC) structures were repaired and augmented by PLC reconstruction. However, the avulsion fracture of Gerdy's tubercle was not fixed because it was minimally displaced and the torn PCL was also not repaired or reconstructed. We present a unique case of pure varus injury to the knee joint. This case contributes to our understanding of the mechanism of knee injury and provides insight regarding appropriate treatment plans for this type of injury. PMID:26217477

  9. Adsorption of hydroxyacetone on pure ice surfaces.

    PubMed

    Petitjean, Mélanie; Darvas, Maria; Picaud, Sylvain; Jedlovszky, Pál; Le Calvé, Stéphane

    2010-12-17

    The adsorption of hydroxyacetone molecules at the surface of ice is investigated by means of flow-tube reactor measurements in the temperature range: 213-253 K. The number of molecules adsorbed per surface unit is conventionally plotted as a function of the absolute gas concentration of hydroxyacetone and is compared to that previously obtained for acetone and ethanol. The enthalpy of adsorption and the monolayer capacity at the ice surface are determined. In addition, molecular dynamics simulations are performed to support the experimental results. However, it is shown that the available interaction potential between hydroxyacetone and ice is not accurate enough to allow a robust detailed analysis of the adsorption process. Finally, a rapid estimation of the hydroxyacetone partitioning between the gas phase and ice shows that in the densest ice clouds, up to 29% of hydroxyacetone could be adsorbed on pure ice surfaces at 203 K.

  10. Synaptic devices based on purely electronic memristors

    NASA Astrophysics Data System (ADS)

    Pan, Ruobing; Li, Jun; Zhuge, Fei; Zhu, Liqiang; Liang, Lingyan; Zhang, Hongliang; Gao, Junhua; Cao, Hongtao; Fu, Bing; Li, Kang

    2016-01-01

    Memristive devices have been widely employed to emulate biological synaptic behavior. In these cases, the memristive switching generally originates from electrical field induced ion migration or Joule heating induced phase change. In this letter, the Ti/ZnO/Pt structure was found to show memristive switching ascribed to a carrier trapping/detrapping of the trap sites (e.g., oxygen vacancies or zinc interstitials) in ZnO. The carrier trapping/detrapping level can be controllably adjusted by regulating the current compliance level or voltage amplitude. Multi-level conductance states can, therefore, be realized in such memristive device. The spike-timing-dependent plasticity, an important Hebbian learning rule, has been implemented in this type of synaptic device. Compared with filamentary-type memristive devices, purely electronic memristors have potential to reduce their energy consumption and work more stably and reliably, since no structural distortion occurs.

  11. Preparation and accurate measurement of pure ozone.

    PubMed

    Janssen, Christof; Simone, Daniela; Guinet, Mickaël

    2011-03-01

    Preparation of high purity ozone as well as precise and accurate measurement of its pressure are metrological requirements that are difficult to meet due to ozone decomposition occurring in pressure sensors. The most stable and precise transducer heads are heated and, therefore, prone to accelerated ozone decomposition, limiting measurement accuracy and compromising purity. Here, we describe a vacuum system and a method for ozone production, suitable to accurately determine the pressure of pure ozone by avoiding the problem of decomposition. We use an inert gas in a particularly designed buffer volume and can thus achieve high measurement accuracy and negligible degradation of ozone with purities of 99.8% or better. The high degree of purity is ensured by comprehensive compositional analyses of ozone samples. The method may also be applied to other reactive gases. PMID:21456766

  12. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure live seed. The tolerance for pure live seed shall be determined...

  13. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure live seed. The tolerance for pure live seed shall be determined...

  14. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure live seed. The tolerance for pure live seed shall be determined...

  15. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure live seed. The tolerance for pure live seed shall be determined...

  16. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure live seed. The tolerance for pure live seed shall be determined...

  17. ThermoData Engine Database - Pure Compounds and Binary Mixtures

    National Institute of Standards and Technology Data Gateway

    SRD 103b NIST ThermoData Engine Version 6.0 - Pure CompoThermoData Engine Database - Pure Compounds and Binary Mixtures (PC database for purchase)   This database contains property data for more than 21,000 pure compounds, 37,500 binary mixtures, 10,000 ternary mixtures, and 6,000 chemical reactions.

  18. Social cognition in "pure" delusional disorder.

    PubMed

    Bömmer, Isabel; Brüne, Martin

    2006-09-01

    Introduction. Delusional disorders are characterised by monothematic, "encapsulated" and incorrigible false beliefs and misinterpretations of social signals. Due to the rarity of cases with "pure" delusional disorder (DD) in clinical settings most studies of social cognition in delusional patients have focused on patients with paranoid schizophrenia. In the present study we sought to examine emotion recognition, theory of mind abilities, and pragmatic language comprehension in patients with delusional disorder. Methods. Social cognition was assessed in 21 patients recruited over a 3-year period who were diagnosed with delusional disorder, paranoid, erotomanic, or jealous type. In addition to an emotion recognition and theory of mind test battery, we included a novel German Proverb Test, which has been found indicative of subtle theory of mind deficits in schizophrenic patients. Executive functioning was assessed using the Wisconsin Card Sorting Test (WCST). Psychopathology was measured using the Positive and Negative Symptoms Scale (PANSS). Patients' task performance was compared to a group of 22 healthy control persons paralleled for verbal intelligence, education, and age. Results. Patients with DD made significantly more perseverative errors in the WCST, they performed more poorly on the theory of mind tasks and the proverb test, but were unimpaired in basic emotion recognition abilities relative to controls. When executive functioning was co-varied out, the group differences in theory of mind disappeared, whereas the greater propensity of patients with DD to interpret proverbs literally remained significant. Conclusions. In "pure" DD the basic social cognitive abilities appear to be preserved. Difficulties in metaphorical speech comprehension and executive functioning could, however, indicate more subtle social cognitive deficits in these patients. PMID:17354084

  19. Accelerating degradation rate of pure iron by zinc ion implantation.

    PubMed

    Huang, Tao; Zheng, Yufeng; Han, Yong

    2016-12-01

    Pure iron has been considered as a promising candidate for biodegradable implant applications. However, a faster degradation rate of pure iron is needed to meet the clinical requirement. In this work, metal vapor vacuum arc technology was adopted to implant zinc ions into the surface of pure iron. Results showed that the implantation depth of zinc ions was about 60 nm. The degradation rate of pure iron was found to be accelerated after zinc ion implantation. The cytotoxicity tests revealed that the implanted zinc ions brought a slight increase on cytotoxicity of the tested cells. In terms of hemocompatibility, the hemolysis of zinc ion implanted pure iron was lower than 2%. However, zinc ions might induce more adhered and activated platelets on the surface of pure iron. Overall, zinc ion implantation can be a feasible way to accelerate the degradation rate of pure iron for biodegradable applications. PMID:27482462

  20. Accelerating degradation rate of pure iron by zinc ion implantation

    PubMed Central

    Huang, Tao; Zheng, Yufeng; Han, Yong

    2016-01-01

    Pure iron has been considered as a promising candidate for biodegradable implant applications. However, a faster degradation rate of pure iron is needed to meet the clinical requirement. In this work, metal vapor vacuum arc technology was adopted to implant zinc ions into the surface of pure iron. Results showed that the implantation depth of zinc ions was about 60 nm. The degradation rate of pure iron was found to be accelerated after zinc ion implantation. The cytotoxicity tests revealed that the implanted zinc ions brought a slight increase on cytotoxicity of the tested cells. In terms of hemocompatibility, the hemolysis of zinc ion implanted pure iron was lower than 2%. However, zinc ions might induce more adhered and activated platelets on the surface of pure iron. Overall, zinc ion implantation can be a feasible way to accelerate the degradation rate of pure iron for biodegradable applications. PMID:27482462

  1. Influences of Al particles on the microstructure and property of electrodeposited Ni-Al composite coatings

    NASA Astrophysics Data System (ADS)

    Cai, Fei; Jiang, Chuanhai

    2014-02-01

    Ni-Al composite coatings with different contents of Al microparticles were prepared from a conventional Watt bath. The influences of Al particle loadings in the bath on the surface morphology, composition, texture, grain size, microstrain, residual stress and anti-corrosion of the Ni-Al composite coating were investigated. The friction coefficients of the coatings at 200 °C were also evaluated by a pin-on-disctribometer. The results showed that the surface morphology of the coatings changed from pyramid + colonied structure to colonied structure with increasing Al particle loadings. The (2 0 0) preferred orientation for pure Ni coating evolved to random orientation with increasing Al particle loadings. The grain size obtained the minimum value of 72.28 nm at Al particle loading of 100 g/L and the microstrain of the coating increased with increasing the Al particle loadings. The incorporation of Al particles decreased the residual stress of the electro-deposited coating and all the coatings deposited at different Al particle loadings possessed low residual stress. As the Al particle loading increased, the anti-corrosion of the Ni-Al coatings increased owing to the combined effect of increasing Al content in the coatings and the texture evolution from (2 0 0) plane to (1 1 1) plane. The wear result suggested that the increasing Al particle content did not improve the wear performance of the Ni-Al composite coatings.

  2. AgraPure Mississippi Biomass Project

    SciTech Connect

    Blackwell,D.A; Broadhead, L.W.; Harrell, W.J.

    2006-03-31

    The AgraPure Mississippi Biomass project was a congressionally directed project, initiated to study the utilization of Mississippi agricultural byproducts and waste products in the production of bio-energy and to determine the feasibility of commercialization of these agricultural byproducts and waste products as feedstocks in the production of energy. The final products from this project were two business plans; one for a Thermal plant, and one for a Biodiesel/Ethanol plant. Agricultural waste fired steam and electrical generating plants and biodiesel plants were deemed the best prospects for developing commercially viable industries. Additionally, oil extraction methods were studied, both traditional and two novel techniques, and incorporated into the development plans. Mississippi produced crop and animal waste biomasses were analyzed for use as raw materials for both industries. The relevant factors, availability, costs, transportation, storage, location, and energetic value criteria were considered. Since feedstock accounts for more than 70 percent of the total cost of producing biodiesel, any local advantages are considered extremely important in developing this particular industry. The same factors must be evaluated in assessing the prospects of commercial operation of a steam and electrical generation plant. Additionally, the access to the markets for electricity is more limited, regulated and tightly controlled than the liquid fuel markets. Domestically produced biofuels, both biodiesel and ethanol, are gaining more attention and popularity with the consuming public as prices rise and supplies of foreign crude become less secure. Biodiesel requires no major modifications to existing diesel engines or supply chain and offers significant environmental benefits. Currently the biodiesel industry requires Federal and State incentives to allow the industry to develop and become self-sustaining. Mississippi has available the necessary feedstocks and is

  3. Alloying of cold-sprayed Al Ni composite coatings by post-annealing

    NASA Astrophysics Data System (ADS)

    Lee, Ha Yong; Jung, Se Hun; Lee, Soo Yong; Ko, Kyung Hyun

    2007-01-01

    A new cold spray coating technique for thick Al coating with finely dispersed Al-Ni intermetallic compounds was tested. For easy powder preparation and high yield, rather than using of Al/compound mixture feed stock, the spraying of pure Al and Ni powders mixture followed by post-annealing was suggested. The powder composition of Al and Ni was 75:25, and 90:10 (wt.%) to expect full consumption of pure Ni into intermetallic compounds. After Al-Ni composite coatings, the Ni particles were finely dispersed and embedded in the Al matrix with a good coating yield. Above 450 °C of post-annealing temperature, the Al 3Ni and Al 3Ni 2 phases were observed in the cold-sprayed Al-Ni coatings. The Ni particles in the Al matrix were fully consumed via compounding reaction with Al at 550 °C of the annealing temperature.

  4. Memory for pure tone sequences without contour.

    PubMed

    Lefebvre, Christine; Jolicœur, Pierre

    2016-06-01

    We presented pure tones interspersed with white noise sounds to disrupt contour perception in an acoustic short-term memory (ASTM) experiment during which we recorded the electroencephalogram. The memory set consisted of seven stimuli, 0, 1, 2, 3, or 4 of which were to-be-remembered tones. We estimated each participant׳s capacity, K, for each set size and measured the amplitude of the SAN (sustained anterior negativity, an ERP related to acoustic short-term memory). We correlated their K slopes with their SAN amplitude slopes as a function of set size, and found a significant link between performance and the SAN: a larger increase in SAN amplitude was linked with a larger number of stimuli maintained in ASTM. The SAN decreased in amplitude in the later portion of the silent retention interval, but the correlation between the SAN and capacity remained strong. These results show the SAN is not an index of contour but rather an index of the maintenance of individual objects in STM. This article is part of a Special Issue entitled SI: Auditory working memory. PMID:26903419

  5. Peccei-Quinn symmetric pure gravity mediation

    NASA Astrophysics Data System (ADS)

    Evans, Jason L.; Ibe, Masahiro; Olive, Keith A.; Yanagida, Tsutomu T.

    2014-07-01

    Successful models of pure gravity mediation (PGM) with radiative electroweak symmetry breaking can be expressed with as few as two free parameters, which can be taken as the gravitino mass and . These models easily support a 125-126 GeV Higgs mass at the expense of a scalar spectrum in the multi-TeV range and a much lighter wino as the lightest supersymmetric particle. In these models, it is also quite generic that the Higgs mixing mass parameter, , which is determined by the minimization of the Higgs potential is also in the multi-TeV range. For , the thermal relic density of winos is too small to account for the dark matter. The same is true for unless the gravitino mass is of order 500 TeV. Here, we consider the origin of a multi-TeV parameter arising from the breakdown of a Peccei-Quinn (PQ) symmetry. A coupling of the PQ-symmetry breaking field, , to the MSSM Higgs doublets, naturally leads to a value of TeV and of the order that is required in PGM models. In this case, axions make up the dark matter or some fraction of the dark matter with the remainder made up from thermal or non-thermal winos. We also provide solutions to the problem of isocurvature fluctuations with axion dark matter in this context.

  6. Foaming of mixtures of pure hydrocarbons

    NASA Technical Reports Server (NTRS)

    Robinson, J. V.; Woods, W. W.

    1950-01-01

    Mixtures of pure liquid hydrocarbons are capable of foaming. Nine hydrocarbons were mixed in pairs, in all possible combinations, and four proportions of each combination. These mixtures were sealed in glass tubes, and the foaming was tested by shaking. Mixtures of aliphatic with other aliphatic hydrocarbons, or of alkyl benzenes with other alkyl benzenes, did not foam. Mixtures of aliphatic hydrocarbons with alkyl benzenes did foam. The proportions of the mixtures greatly affected the foaming, the maximum foaming of 12 of 20 pairs being at the composition 20 percent aliphatic hydrocarbon, 80 percent alkyl benzene. Six seconds was the maximum foam lifetime of any of these mixtures. Aeroshell 120 lubricating oil was fractionated into 52 fractions and a residue by extraction with acetone in a fractionating extractor. The index of refraction, foam lifetime, color, and viscosity of these fractions were measured. Low viscosity and high index fractions were extracted first. The viscosity of the fractions extracted rose and the index decreased as fractionation proceeded. Foam lifetimes and color were lowest in the middle fractions. Significance is attached to the observation that none of the foam lifetimes of the fractions or residue is as high as the foam lifetime of the original Aeroshell, indicating that the foaming is not due to a particular foaming constituent, but rather to the entire mixture.

  7. Memory for pure tone sequences without contour.

    PubMed

    Lefebvre, Christine; Jolicœur, Pierre

    2016-06-01

    We presented pure tones interspersed with white noise sounds to disrupt contour perception in an acoustic short-term memory (ASTM) experiment during which we recorded the electroencephalogram. The memory set consisted of seven stimuli, 0, 1, 2, 3, or 4 of which were to-be-remembered tones. We estimated each participant׳s capacity, K, for each set size and measured the amplitude of the SAN (sustained anterior negativity, an ERP related to acoustic short-term memory). We correlated their K slopes with their SAN amplitude slopes as a function of set size, and found a significant link between performance and the SAN: a larger increase in SAN amplitude was linked with a larger number of stimuli maintained in ASTM. The SAN decreased in amplitude in the later portion of the silent retention interval, but the correlation between the SAN and capacity remained strong. These results show the SAN is not an index of contour but rather an index of the maintenance of individual objects in STM. This article is part of a Special Issue entitled SI: Auditory working memory.

  8. Pure inorganic separator for lithium ion batteries.

    PubMed

    He, Meinan; Zhang, Xinjie; Jiang, Kuiyang; Wang, Joe; Wang, Yan

    2015-01-14

    Battery safety is critical for many applications including portable electronics, hybrid and electric vehicles, and grid storage. For lithium ion batteries, the conventional polymer based separator is unstable at 120 °C and above. In this research, we have developed a pure aluminum oxide nanowire based separator; this separator does not contain any polymer additives or binders; additionally, it is a bendable ceramic. The physical and electrochemical properties of the separator are investigated. The separator has a pore size of about 100 nm, and it shows excellent electrochemical properties under both room and high temperatures. At room temperature, the ceramic separator shows a higher rate capability compared to the conventional Celgard 2500 separator and life cycle performance does not show any degradation. At 120 °C, the cell with the ceramic separator showed a much better cycle performance than the conventional Celgard 2500 separator. Therefore, we believe that this research is really an exciting scientific breakthrough for ceramic separators and lithium ion batteries and could be potentially used in the next generation lithium ion batteries requiring high safety and reliability.

  9. Shifting from preconceptions to pure wonderment.

    PubMed

    Porr, Caroline

    2005-07-01

    The author reflects upon her role as a public health nurse striving to attain practice authenticity. Client assessment and nursing interventions were seemingly sufficient until she became curious about 'Who is this person sitting across from me?' and 'What are her experiences in the world as a lone parent living in poverty at the margins of society?' The author begins to think that she could shift from mere client investigation to pure wonderment about the Other by imagining herself as a researcher, an explorer of another's life world. Ultimately this process enables her to enhance the 'caring' in her practice with the knowledge gained of the perceptions and meanings impoverished clients assigned to their everyday lives. Jurgen Habermas' theory of communicative competence serves as the reference map guiding exploration. The author uses Habermas' theoretical principles of intersubjective mutuality--the validity claims of comprehensibility, truth, sincerity, and legitimacy. Comprehensibility embodies understanding, an attitude of unconditional acceptance, and care respect of another's individual person and self-defined reality. Intersubjective mutuality also requires that one dwell in the moment with the Other, satisfied that communication is founded on truth. Sincerity implies fostering the Other's expression of authentic self apart from oppressive distracters. Lastly, legitimacy reconciles the author's altruistic pursuit to know the Other's ontological truth with the reality of the present world.

  10. Calibration of sound velocimeter in pure water

    NASA Astrophysics Data System (ADS)

    Li, Zhiwei; Zhang, Baofeng; Li, Tao; Zhu, Junchao; Xie, Ziming

    2016-01-01

    Accurate measurement of sound speed is important to calibrate a sound velocity profiler which provides real-time sound velocity to the sonar equipment in oceanographic survey. The sound velocity profiler calculates the sound speed by measuring the time-of-flight of a 1 MHz single acoustic pulse to travel over about 300 mm path. A standard sound velocimeter instrument was invited to calibrate the sound velocity profiler in pure water at temperatures of 278,283, 288, 293, 298, 303 and 308K in a thermostatic vessel at one atmosphere. The sound velocity profiler was deployed in the thermostatic vessel alongside the standard sound velocimeter instrument and two platinum resistance thermometers (PRT) which were calibrated to 0.002k by comparison with a standard PRT. Time of flight circuit board was used to measure the time-of-flight to 22 picosecond precision. The sound speed which was measured by the sound velocity profiler was compared to the standard sound speed calculated by UNESCO to give the laboratory calibration coefficients and was demonstrated agreement with CTD-derived sound speed using Del Grosso's seawater equation after removing a bias.

  11. Localization of aerial pure tones by pinnipeds

    NASA Astrophysics Data System (ADS)

    Holt, Marla M.; Schusterman, Ronald J.; Kastak, David; Southall, Brandon L.

    2005-12-01

    In this study, minimum audible angles (MAAs) of aerial pure tones were measured in and compared between a northern elephant seal (Mirounga angustirostris), a harbor seal (Phoca vitulina), and a California sea lion (Zalophus californianus). Testing was conducted between 0.8 and 16 kHz in the elephant seal and 0.8 and 20 kHz in the harbor seal and sea lion in a hemi-anechoic chamber using a left/right psychophysical procedure. Performance for the same frequencies was also quantified for discrete speaker separation of 5° from the mid-line. For all subjects, MAAs ranged from approximately 3° to 15° and were generally equal to or larger than those previously measured in the same subjects with a broadband signal. Performance at 5° ranged from chance to 97% correct, depending on frequency and subject. Poorest performance in the sea lion and harbor seal occurred at intermediate frequencies, which is consistent with the duplex theory of sound localization. In contrast, the elephant seal's poorest performance occurred at higher frequencies. The elephant seal's result suggests an inferior ability to utilize interaural level differences and is perhaps related to best hearing sensitivity shifted toward lower frequencies in this species relative to other pinnipeds.

  12. Photoionization Dynamics in Pure Helium Droplets

    SciTech Connect

    Peterka, Darcy S.; Kim, Jeong Hyun; Wang, Chia C.; Poisson,Lionel; Neumark, Daniel M.

    2007-02-04

    The photoionization and photoelectron spectroscopy of pure He droplets are investigated at photon energies between 24.6 eV (the ionization energy of He) and 28 eV. Time-of-flight mass spectra and photoelectron images were obtained at a series of molecular beam source temperatures and pressures to assess the effect of droplet size on the photoionization dynamics. At source temperatures below 16 K, the photoelectron images are dominated by fast electrons produced via direct ionization of He atoms, with a small contribution from very slow electrons with kinetic energies below 1 meV arising from an indirect mechanism. The fast photoelectrons have as much as 0.5 eV more kinetic energy than those from atomic He at the same photon energy. This result is interpreted and simulated within the context of a 'dimer model', in which one assumes vertical ionization from two nearest neighbor He atoms to the attractive region of the He2+ potential energy curve. Possible mechanism for the slow electrons, which were also seen at energies below IE(He), are discussed, including vibrational autoionizaton of Rydberg states comprising an electron weakly bound to the surface of a large HeN+ core.

  13. Al Composites

    NASA Astrophysics Data System (ADS)

    Chandanayaka, Tharaka; Azarmi, Fardad

    2014-05-01

    In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 μm were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

  14. Why So Little Faith? A Reply to Blanton and Jaccard's (2006) Skeptical View of Testing Pure Multiplicative Theories

    ERIC Educational Resources Information Center

    Greenwald, Anthony G.; Rudman, Laurie A.; Nosek, Brian A.; Zayas, Vivian

    2006-01-01

    Blanton and Jaccard questioned the 4-test regression method used by Greenwald et al. to test a pure multiplicative theory. The present authors address Blanton and Jaccard's concerns with a combination of simulations and meta-analysis. Simulations show that (a) Blanton and Jaccard's preferred simultaneous regression method has a severe power loss…

  15. High temperature deformation of NiAl and CoAl

    NASA Technical Reports Server (NTRS)

    Nix, W. D.

    1982-01-01

    The high temperature mechanical properties of the aluminides are reviewed with respect to their potential as high temperature structural materials. It is shown that NiAl and CoAl are substantially stronger than the pure metals Ni and Co at high temperatures and approach the strength of some superalloys, particularly when those superalloys are tested in "weak" directions. The factors that limit and control the high temperature strengths of NiAl and CoAl are examined to provide a basis for the development of intermetallic alloys of this type.

  16. Characterizing commercial pureed foods: sensory, nutritional, and textural analysis.

    PubMed

    Ettinger, Laurel; Keller, Heather H; Duizer, Lisa M

    2014-01-01

    Dysphagia (swallowing impairment) is a common consequence of stroke and degenerative diseases such as Parkinson's and Alzheimer's. Limited research is available on pureed foods, specifically the qualities of commercial products. Because research has linked pureed foods, specifically in-house pureed products, to malnutrition due to inferior sensory and nutritional qualities, commercial purees also need to be investigated. Proprietary research on sensory attributes of commercial foods is available; however direct comparisons of commercial pureed foods have never been reported. Descriptive sensory analysis as well as nutritional and texture analysis of commercially pureed prepared products was performed using a trained descriptive analysis panel. The pureed foods tested included four brands of carrots, of turkey, and two of bread. Each commercial puree was analyzed for fat (Soxhlet), protein (Dumas), carbohydrate (proximate analysis), fiber (total fiber), and sodium content (Quantab titrator strips). The purees were also texturally compared with a line spread test and a back extrusion test. Differences were found in the purees for sensory attributes as well as nutritional and textural properties. Findings suggest that implementation of standards is required to reduce variability between products, specifically regarding the textural components of the products. This would ensure all commercial products available in Canada meet standards established as being considered safe for swallowing.

  17. Pure-phase and pure-amplitude hologram design using the method of generalized projections

    NASA Astrophysics Data System (ADS)

    Catino, William Charles

    The overall contribution of the research presented in this dissertation is a systematic procedure for designing computer-generated holograms subject to far-field image constraints. The method of generalized projections is used to design pure-phase and pure-amplitude diffraction holograms that generate prescribed gray-scale images in the Fourier frequency plane. Performance is demonstrated with objective measures (error, efficiency, and variance), as well as with subjective comparison of images. Test images include a photographic quality image of Lena, a uniform intensity spot array, and a binary amplitude block text image. Projection algorithms are derived for pure-phase holograms with both continuous and quantized phase characteristics from a prescribed far-field magnitude constraint. The performance of the pure-phase hologram designs, as measured in the far-field image, is always very good for the continuous phase case and for the quantized phase case with a large number of phase quantization levels. However, as the number of quantization levels decreases, the performance typically degrades. Performance is significantly improved by constraining the energy in mutually exclusive cliques, that is, groups of image plane (far-field) pixels, instead of constraining the intensity of each individual pixel. Even for the binary phase case, acceptable images are generated with the clique energy algorithm. The method of generalized projections is also used to design pure-amplitude diffraction holograms using a prescribed image intensity constraint. Two algorithms are derived: the direct method, which nonlinearly constrains the hologram transmittance to the range of real values in (0,1); and the indirect method, which constrains the transmittance values to the real axis, and linearly transforms the resulting values to the range (0,1). Digital amplitude holograms are simulated by quantizing the amplitude holograms resulting from the indirect method. The indirect method

  18. Phase competition in ternary Ti-Ni-Al system

    NASA Astrophysics Data System (ADS)

    Wierzba, Bartek

    2016-07-01

    In this paper the reactive diffusion in Ti-Ni-Al system is discussed at 1173 K. The calculation method based on the binary approach is presented. The key kinetic parameter is Wagner integral diffusion coefficient. The experimental and simulation results of reactive diffusion between pure Ti and β-NiAl are compared at 1173 K after 100 h.

  19. Pure Java-based streaming MPEG player

    NASA Astrophysics Data System (ADS)

    Tolba, Osama; Briceno, Hector; McMillan, Leonard

    1999-01-01

    We present a pure Java-based streaming MPEG-1 video player. By implementing the player entirely in Java, we guarantee its functionality across platforms within any Java-enabled web browsers, without the need for native libraries. This allows greater sue of MPEG video sequences, because the users will no longer need to pre-install any software to display video, beyond Java compatibility. This player features a novel forward-mapping IDCT algorithm that allows it to play locally stored, CIF-sized video sequences at 11 frames per second, when run on a personal computer with Java 'just-in-time' compiler. The IDCT algorithm can run with greater speed when the sequence is viewed at reduced size; e.g., performing approximately 1/4 the amount of computation when the user resizes the sequence to 1/2 its original width and height. We are able to play video streams stored anywhere on the Internet with acceptable performance using a proxy server, eliminating the need for large-capacity auxiliary storage. Thus, the player is well suited to small devices, such as digital TV set-top decoders, requiring little more memory than is required for three video frames. Because of our modular design, it is possible to assemble multiple video streams from remote sources and present them simultaneously to the viewers, subject to network and local performance limitations. The same modular system can further provide viewers with their own customized view of each sessions; e.g., moving and resizing the video display window dynamically, and selecting their preferred set of video controls.

  20. Predictions of pure liquid shock Hugoniots

    SciTech Connect

    Hobbs, M.L.; Baer, M.R.

    1998-06-01

    Determination of product species and associated equations-of-state (EOS) for energetic materials such as pyrotechnics with complex elemental compositions remains a major unsolved problem. Although, empirical EOS models may be calibrated to replicate detonation conditions within experimental variability (5--10%), different states, e.g. expansion, may produce significant discrepancy with data if the basic form of the EOS model is incorrect. A more physically realistic EOS model based on intermolecular potentials, such as the Jacobs Cowperthwaite Zwisler (JCZ3) EOS, is needed to predict detonation states as well as expanded states. Predictive capability for any EOS requires a large species data base composed of a wide variety of elements. Unfortunately, only 20 species have known exponential 6 (EXP 6) molecular force constants which are used in the JCZ3-EOS. Of these 20 species, only 10 have been adequately compared to experimental data such as molecular scattering or shock Hugoniot data. Since data in the strongly repulsive region of the molecular potential is limited, alternative methods must be found to deduce force constants for a larger number of species. The objective of the present study is to determine JCZ3 product species force constants using corresponding state theory. Intermolecular potential parameters were obtained for a variety of gas species using a simple corresponding states technique with critical volume and critical temperature. A more complex, four parameter corresponding state method with shape and polarity corrections was also used to obtain intermolecular potential parameters. Both corresponding state methods were used to predict shock Hugoniot data obtained from pure liquids. The simple corresponding state method is shown to give adequate agreement with shock Hugoniot data.

  1. Entanglement bound for multipartite pure states based on local measurements

    SciTech Connect

    Jiang Lizhen; Chen Xiaoyu; Ye Tianyu

    2011-10-15

    An entanglement bound based on local measurements is introduced for multipartite pure states. It is the upper bound of the geometric measure and the relative entropy of entanglement. It is the lower bound of the minimal-measurement entropy. For pure bipartite states, the bound is equal to the entanglement entropy. The bound is applied to pure tripartite qubit states and the exact tripartite relative entropy of entanglement is obtained for a wide class of states.

  2. Typical pure nonequilibrium steady states and irreversibility for quantum transport.

    PubMed

    Monnai, Takaaki; Yuasa, Kazuya

    2016-07-01

    It is known that each single typical pure state in an energy shell of a large isolated quantum system well represents a thermal equilibrium state of the system. We show that such typicality holds also for nonequilibrium steady states (NESS's). We consider a small quantum system coupled to multiple infinite reservoirs. In the long run, the total system reaches a unique NESS. We identify a large Hilbert space from which pure states of the system are to be sampled randomly and show that the typical pure states well describe the NESS. We also point out that the irreversible relaxation to the unique NESS is important to the typicality of the pure NESS's.

  3. Typical pure nonequilibrium steady states and irreversibility for quantum transport

    NASA Astrophysics Data System (ADS)

    Monnai, Takaaki; Yuasa, Kazuya

    2016-07-01

    It is known that each single typical pure state in an energy shell of a large isolated quantum system well represents a thermal equilibrium state of the system. We show that such typicality holds also for nonequilibrium steady states (NESS's). We consider a small quantum system coupled to multiple infinite reservoirs. In the long run, the total system reaches a unique NESS. We identify a large Hilbert space from which pure states of the system are to be sampled randomly and show that the typical pure states well describe the NESS. We also point out that the irreversible relaxation to the unique NESS is important to the typicality of the pure NESS's.

  4. Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions.

    PubMed

    Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

    2015-09-21

    Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

  5. Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions

    NASA Astrophysics Data System (ADS)

    Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

    2015-09-01

    Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

  6. Efficient decomposition of cosmic microwave background polarization maps into pure E, pure B, and ambiguous components

    SciTech Connect

    Bunn, Emory F.

    2011-04-15

    Separation of the B component of a cosmic microwave background (CMB) polarization map from the much larger E component is an essential step in CMB polarimetry. For a map with incomplete sky coverage, this separation is necessarily hampered by the presence of ambiguous modes which could be either E or B modes. I present an efficient pixel-space algorithm for removing the ambiguous modes and separating the map into pure E and B components. The method, which works for arbitrary geometries, does not involve generating a complete basis of such modes and scales the cube of the number of pixels on the boundary of the map.

  7. Localization of airborne pure tones by pinnipeds

    NASA Astrophysics Data System (ADS)

    Holt, Marla M.; Schusterman, Ronald J.; Southall, Brandon L.; Kastak, David

    2001-05-01

    Although all pinnipeds communicate acoustically in air, most previous research on sound localization has been done under water. We have recently shown that several pinniped species localize aerial broadband signals as well as some terrestrial carnivores [Holt et al., J. Acoust. Soc. Am. 113 (2003)]. However, it is unclear which frequencies are particularly important for localization in these animals. In this study, we tested a harbor seal (Phoca vitulina) and a California sea lion (Zalophus californianus) in a hemianechoic chamber at frequencies ranging between 0.8 and 20 kHz. A left/right procedure was used to measure minimum audible angles (MAAs) corresponding to 75%-correct discrimination. MAAs ranged from approximately 4 to 13 deg in both subjects, with the largest MAAs or poorest acuity measured at the intermediate frequencies tested. These results are consistent with the duplex theory of sound localization in that low-frequency sounds appear to be localized on the basis of interaural time differences, while high-frequency sounds appear to be localized on the basis of interaural intensity differences. Testing with a northern elephant seal (Mirounga angustirostris) will provide further insight on the use of binaural cues and head-size effects with respect to localization in pinnipeds.

  8. 1. SOUTH AND WEST ELEVATION OF ILLINOIS PURE ALUMINUM (IPA) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SOUTH AND WEST ELEVATION OF ILLINOIS PURE ALUMINUM (IPA) COMPANY FACTORY; SOUTH ELEVATION FACING ILLINOIS CENTRAL GULF RAILROAD TRACKS AND MAIN STREET. THE ONE-STORY BRICK BUILDING TO THE LEFT IS AN ABANDONED COMMONWEALTH EDISON COMPANY ELECTRICAL SUBSTATION. - Illinois Pure Aluminum Company, 109 Holmes Street, Lemont, Cook County, IL

  9. Physical and Spiritual Education within the Framework of Pure Life

    ERIC Educational Resources Information Center

    Bagheri Noaparast, Khosrow

    2013-01-01

    This paper aims at showing the dimensions of spirituality in childhood education by suggesting a new analysis of the concept of "pure life" used in the Qur'an. Putting spirituality in the framework of the pure life provides us with a rich framework in dealing with spirituality as the latter will be extended to all dimensions of a life. In the…

  10. Laser ablation of Al-Ni alloys and multilayers

    NASA Astrophysics Data System (ADS)

    Roth, Johannes; Trebin, Hans-Rainer; Kiselev, Alexander; Rapp, Dennis-Michael

    2016-05-01

    Laser ablation of Al-Ni alloys and multilayers has been studied by molecular dynamics simulations. The method was combined with a two-temperature model to describe the interaction between the laser beam, the electrons, and the atoms. As a first step, electronic parameters for the alloys had to be found and the model developed originally for pure metals had to be generalized to multilayers. The modifications were verified by computing melting depths and ablation thresholds for pure Al and Ni. Here known data could be reproduced. The improved model was applied to the alloys Al_3Ni, AlNi and AlNi_3. While melting depths and ablation thresholds for AlNi behave unspectacular, sharp drops at high fluences are observed for Al_3Ni and AlNi_3. In both cases, the reason is a change in ablation mechanism from phase explosion to vaporization. Furthermore, a phase transition occurs in Al_3Ni. Finally, Al layers of various thicknesses on a Ni substrate have been simulated. Above threshold, 8 nm Al films are ablated as a whole while 24 nm Al films are only partially removed. Below threshold, alloying with a mixture gradient has been observed in the thin layer system.

  11. Effect of Mg or Ag addition on the evaporation field of Al.

    PubMed

    Aruga, Yasuhiro; Nako, Hidenori; Tsuneishi, Hidemasa; Hasegawa, Yuki; Tao, Hiroaki; Ichihara, Chikara; Serizawa, Ai

    2013-09-01

    It is known that the distribution of the charge-states as well as the evaporation field shift to higher values as the specimen temperature is decreased at a constant rate of evaporation. This study has explored the effect of Mg or Ag addition on the evaporation field of Al in terms of the charge state distribution of the field evaporated Al ions. The fractional abundance of Al(2+) ions with respect to the total Al ions in Al-Mg alloy is lower than that in pure Al, whereas it shows higher level in the Al-Ag alloy at lower temperatures. The temperature dependence of the fractional abundance of Al(2+) ions has been also confirmed, suggesting that Al atoms in the Al-Mg alloy need lower evaporation field, while higher field is necessary to evaporate Al atoms in the Al-Ag alloy, compared with pure Al. This tendency is in agreement with that of the evaporation fields estimated theoretically by means of measurements of the work function and calculations of the binding energy of the pure Al, Al-Mg and Al-Ag alloys.

  12. Pure spin current in lateral structures

    NASA Astrophysics Data System (ADS)

    Chen, Shuhan

    Spintronics, a frontier academic research area, is advancing rapidly in recent years. It has been chosen as one of the promising candidates for overcoming the obstacles in continuing the "Moore's Law" of the electronics industry. Spintronics employs both spin and charge degrees of freedom of electrons to reduce energy consumption and increase the flexibility of IC design. To achieve this, it is extremely important to understand the generation, transport, and detection of the spin polarized current (spin current). In this work we use a mesoscopic metallic spintronic structure-nonlocal spin valve (NLSV)-for fundamental studies of spintronics. A nonlocal spin valve consists of two ferromagnetic electrodes (a spin injector and a spin detector) bridged by a non-magnetic spin channel. A thin aluminum oxide barrier (~ 2 - 3 nm) has been shown to effectively enhance the spin injection and detection polarizations. We have studied spin injection and detection in these nanoscale structures. Several topics will be discussed in this work. In Chapter 4 we explore spin transport in NLSVs with Ag channels. Substantial spin signals are observed. The temperature dependence of the spin signals indicates long spin diffusion lengths and low surface spin-flip rate in the mesoscopic Ag channels. Chapter 5 will focus on the asymmetric spin absorption across the low-resistance AlOx barriers in NLSVs. This effect allows for a more simplified and efficient detection scheme for the spin accumulation. Then in Chapter 6 we report a large spin signal owing to a highly resistive break-junction. We have also developed a model to describe the spin-charge coupling effect which enables the large spin signal. In the end, Spin Hall Effect (SHE) is investigated in Chapter 7. A mesoscopic Pt film is utilized to inject a spin accumulation into a mesoscopic Cu channel via the SHE. The spin accumulation in Cu can be detected by the nonlocal method. The reciprocal effect -- the inverse Spin Hall Effect - (i

  13. Empirical relation between surface tension and density for some pure liquid metals

    NASA Astrophysics Data System (ADS)

    Ceotto, D.

    2015-12-01

    A new investigation is conducted on the experimental values of surface tension and density for some common pure liquid metals. Using the most recent and accredited data a new relation is found between these values for Au, Cu, Sn, Al, Pb, In, Bi, Ni, Co, Fe, Ba, Na, Nd, Ga, and Sb. The proportion constant has then been calculated giving an accuracy R2 equal to about 0.98. The equation proposed finds agreement with other theoretical models present in literature; it can be used by engineers in many industrial fields to predict the variables but also to simulate macroscopic processes involving liquid metals.

  14. Interdiffusion in Diffusion Couples: U-Mo v. Al and Al-Si

    SciTech Connect

    D. D. Keiser, Jr.; E. Perez; B. Yao; Y. H. Sohn

    2009-11-01

    Interdiffusion and microstructural development in the U-Mo-Al system was examined using solid-tosolid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, annealed at 600°C for 24 hours. The influence of Si alloying addition (up to 5 wt.%) in Al on the interdiffusion microstructural development was also examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, Al-2wt.%Si, and Al-5wt.%Si annealed at 550°C up to 20 hours. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) were employed to examine the development of a very fine multiphase intermetallic layer. In ternary U-Mo-Al diffusion couples annealed at 600°C for 24 hours, interdiffusion microstructure varied of finely dispersed UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases while the average composition throughout the interdiffusion zone remained constant at approximately 80 at.% Al. Interdiffusion microstructure observed by SEM/TEM analyses and diffusion paths drawn from concentration profiles determined by EPMA appear to deviate from the assumption of “local thermodynamic equilibrium,” and suggest that interdiffusion occurs via supersaturated UAl4 followed by equilibrium transformation into UAl3, U6Mo4Al43, UAl4 and UMo2Al20 phases. Similar observation was made for U-Mo vs. Al diffusion couples annealed at 550°C. The addition of Si (up to 5 wt.%) in Al significantly reduced the thickness of the intermetallic layer by changing the constituent phases of the interdiffusion zone developed in U-Mo vs. Al-Si diffusion couples. Specifically, the formation of (U,Mo)(Al,Si)3 with relatively large solubility for Mo and Si, along with UMo2Al20 phases was observed along with disappearance of U6Mo4Al43 and UAl4 phases. Simplified understanding based on U-Al, U-Si, and Mo-Si binary phase diagrams is discussed in the light of the beneficial effect of Si alloying addition.

  15. Shunting arc plasma source for pure carbon ion beam.

    PubMed

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

  16. Shunting arc plasma source for pure carbon ion beama)

    NASA Astrophysics Data System (ADS)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm2 at the peak of the pulse.

  17. Pure-state informationally complete and 'really' complete measurements

    SciTech Connect

    Finkelstein, J.

    2004-11-01

    I construct a positive-operator-valued measure (POVM) which has 2d rank-1 elements and which is informationally complete for generic pure states in d dimensions, thus confirming a conjecture made by Flammia, Silberfarb, and Caves (e-print quant-ph/0404137). I show that if a rank-1 POVM is required to be informationally complete for all pure states in d dimensions, it must have at least 3d-2 elements. I also show that, in a POVM which is informationally complete for all pure states in d dimensions, for any vector there must be at least 2d-1 POVM elements which do not annihilate that vector.

  18. Effect of humidity on fretting wear of several pure metals

    NASA Technical Reports Server (NTRS)

    Goto, H.; Buckley, D. H.

    1984-01-01

    Fretting wear experiments with several pure metals were conducted in air at various relative humidity levels. The materials used were iron, aluminum, copper, silver, chromium, titanium, and nickel. Each pure metal had a maximum fretting wear volume at a specific humidity level RH sub max that was not dependent on mechanical factors such as contact load, fretting amplitude, and frequency in the ranges studied. The weight loss due to fretting wear at RH sub max for each pure metal decreased with increasing heat of oxygen adsorption on the metal, indicating that adhesive wear dominated at RH sub max.

  19. Some TEM observations of Al2O3 scales formed on NiCrAl alloys

    NASA Technical Reports Server (NTRS)

    Smialek, J.; Gibala, R.

    1979-01-01

    The microstructural development of Al2O3 scales on NiCrAl alloys has been examined by transmission electron microscopy. Voids were observed within grains in scales formed on a pure NiCrAl alloy. Both voids and oxide grains grew measurably with oxidation time at 1100 C. The size and amount of porosity decreased towards the oxide-metal growth interface. The voids resulted from an excess number of oxygen vacancies near the oxidemetal interface. Short-circuit diffusion paths were discussed in reference to current growth stress models for oxide scales. Transient oxidation of pure, Y-doped, and Zr-doped NiCrAl was also examined. Oriented alpha-(Al, Cr)2O3 and Ni(Al, Cr)2O4 scales often coexisted in layered structures on all three alloys. Close-packed oxygen planes and directions in the corundum and spinel layers were parallel. The close relationship between oxide layers provided a gradual transition from initial transient scales to steady state Al2O3 growth.

  20. Formation of Small Blocky Al3Ti Particles via Direct Reaction Between Solid Ti Powders and Liquid Al

    NASA Astrophysics Data System (ADS)

    Liu, Z. W.; Han, Q.; Li, J. G.

    2012-12-01

    The evolution of titanium powders in the pure aluminum melt at a lower temperature was studied in our research. The process involved some titanium powders being added into the pure aluminum melt at 1003 K (730 °C), and then the melt was cast into an ingot after 5 minutes. A reaction layer composed of some loose Al3Ti particles was formed on the solid Ti surface due to the reactive diffusion between titanium and aluminum. In-situ blocky Al3Ti particles smaller than 5 μm were produced in the aluminum matrix. A reaction-peeling model was suggested to illustrate the formation mechanism of Al3Ti particles, and a simple approach for fabricating in-situ Al3Ti/Al-alloy composites was proposed as well.

  1. Faster and cleaner real-time pure shift NMR experiments

    NASA Astrophysics Data System (ADS)

    Mauhart, Johannes; Glanzer, Simon; Sakhaii, Peyman; Bermel, Wolfgang; Zangger, Klaus

    2015-10-01

    Real-time pure shift experiments provide highly resolved proton NMR spectra which do not require any special processing. Although being more sensitive than their pseudo 2D counterparts, their signal intensities per unit time are still far below regular NMR spectra. In addition, scalar coupling evolution during the individual data chunks produces decoupling sidebands. Here we show that faster and cleaner real-time pure shift spectra can be obtained through the implementation of two parameter alterations. Variation of the FID chunk lengths between individual transients significantly suppresses decoupling sidebands for any kind of real-time pure shift spectra and thus allows for example the analysis of minor components in compound mixtures. Shifting the excitation frequency between individual scans of real-time slice-selective pure shift spectra increases their sensitivity obtainable in unit time by allowing faster repetitions of acquisitions.

  2. [Neurolinguistic analysis of a case of pure agraphia].

    PubMed

    Petrillo, S; Poli, R; Piccirilli, M

    1990-01-01

    A patient with a pure acquired dysgraphia is reported. The pattern of the patient's performance is discussed in relation to current functional models of writing. The case may be interpreted by assuming a selective impairment to the graphemic buffer.

  3. Typical pure nonequilibrium steady states and irreversibility for quantum transport.

    PubMed

    Monnai, Takaaki; Yuasa, Kazuya

    2016-07-01

    It is known that each single typical pure state in an energy shell of a large isolated quantum system well represents a thermal equilibrium state of the system. We show that such typicality holds also for nonequilibrium steady states (NESS's). We consider a small quantum system coupled to multiple infinite reservoirs. In the long run, the total system reaches a unique NESS. We identify a large Hilbert space from which pure states of the system are to be sampled randomly and show that the typical pure states well describe the NESS. We also point out that the irreversible relaxation to the unique NESS is important to the typicality of the pure NESS's. PMID:27575115

  4. Pure gonadal dysgenesis (46 XX type) with a familial pattern.

    PubMed

    Kohmanaee, Shahin; Dalili, Setila; Rad, Afagh Hassanzadeh

    2015-01-01

    46, XX gonadal dysgenesis without the phenotype of Turner's syndrome is described as "pure". Although, previous investigations obtained that commonly gonadal dysgenesis did not cause breast development as a result of low levels of circulating estradiol. However, in this study, we aimed to report a familial pure gonadal dysgenesis with and without normal secondary sexual characteristics. In this study, we reported three siblings with pure gonadal dysgenesis with and without normal secondary sexual characteristics. The elder two sisters had a normal female phenotype and the youngest had amenorrhea with no breast development (B1) and pubic hair. In addition, it seems that the absence of pubic hair occurred due to delayed constitutional puberty. According to results, it seems that clinicians should consider different presentations for pure gonadal dysgenesis with familial pattern.

  5. The effect of pure state structure on nonequilibrium dynamics

    NASA Astrophysics Data System (ADS)

    Newman, C. M.; Stein, D. L.

    2008-06-01

    Motivated by short-range Ising spin glasses, we review some rigorous results and their consequences for the relation between the number/nature of equilibrium pure states and nonequilibrium dynamics. Two of the consequences for spin glass dynamics following an instantaneous deep quench to a temperature with broken spin flip symmetry are: (1) almost all initial configurations lie on the boundary between the basins of attraction of multiple pure states; (2) unless there are uncountably many pure states with almost all pairs having zero overlap, there can be no equilibration to a pure state as time t \\to \\infty . We discuss the relevance of these results to the difficulty of equilibration of spin glasses. We also review some results concerning the 'nature versus nurture' problem of whether the large-t behavior of both ferromagnets and spin glasses following a deep quench is determined more by the initial configuration (nature) or by the dynamics realization (nurture).

  6. A novel TiAl3/Al2O3 composite coating on γ-TiAl alloy and evaluating the oxidation performance

    NASA Astrophysics Data System (ADS)

    Wang, Jiqiang; Kong, Lingyan; Li, Tiefan; Xiong, Tianying

    2016-01-01

    A novel TiAl3/Al2O3 composite coating was prepared on γ-TiAl alloy. The process included two steps: (1) TiAl3/Al2O3 composite powders were prepared by high energy ball milling of pure Al and nano-TiO2 powders, followed by a heat-treatment; (2) the as-prepared composite powders were deposited on γ-TiAl substrate by cold spray. The cyclic oxidation was conducted at 900 °C to test the performance of the composite coating. The results showed that the composite coating had good crack resistance and effectively decreased the oxidation rate of the substrate.

  7. Acquired pure megakaryocytic aplasia successfully treated with cyclosporine.

    PubMed

    Omri, Halima El; Ibrahim, Firyal; Taha, Ruba Yasin; Negm, Riham Hassan; Khinji, Aisha Al; Yassin, Mohammed; Hijji, Ibrahim Al; Ayoubi, Hanadi El; Baden, Hussein

    2010-12-01

    Acquired pure megakaryocytic aplasia is a rare hematological disorder characterized by thrombocytopenia with absent or markedly reduced megakaryocytes in the bone marrow. We report a case of a 25-year-old male diagnosed as acquired pure megakaryocytic aplasia. Treatment with prednisone and intravenous immunoglobulin failed, but he was successfully treated with cyclosporine, with complete remission after 90 days and normal platelet count maintained thereafter. PMID:27263744

  8. Clinical study of 222 patients with pure motor stroke.

    PubMed

    Arboix, A; Padilla, I; Massons, J; García-Eroles, L; Comes, E; Targa, C

    2001-08-01

    The objective was to assess the frequency of pure motor stroke caused by different stroke subtypes and to compare demographic, clinical, neuroimaging, and outcome data of pure motor stroke with those of patients with other lacunar stroke as well as with those of patients with non-lacunar stroke. Data from 2000 patients with acute stroke (n=1761) or transient ischaemic attack (n=239) admitted consecutively to the department of neurology of an acute care 350 bed teaching hospital were prospectively collected in the Sagrat Cor Hospital of Barcelona stroke registry over a 10 year period. For the purpose of the study 222 (12.7%) patients with pure motor stroke were selected. The other study groups included 218 (12.3%) patients with other lacunar strokes and 1321 (75%) patients with non-lacunar stroke. In relation to stroke subtype, lacunar infarcts were found in 189 (85%) patients, whereas ischaemic lacunar syndromes not due to lacunar infarcts occurred in 23 (10.4%) patients (atherothrombotic stroke in 12, cardioembolic stroke in seven, infarction of undetermined origin in three, and infarction of unusual aetiology in one) and haemorrhagic lacunar syndromes in 10 (4.5%). Patients with pure motor stroke showed a better outcome than patients with non-lacunar stroke with a significantly lower number of complications and in hospital mortality rate, shorter duration of hospital stay, and a higher number of symptom free patients at hospital discharge. After multivariate analysis, hypertension, diabetes, obesity, hyperlipidaemia, non-sudden stroke onset, internal capsule involvement, and pons topography seemed to be independent factors of pure motor stroke in patients with acute stroke. In conclusion, about one of every 10 patients with acute stroke had a pure motor stroke. Pure motor stroke was caused by a lacunar infarct in 85% of patients and by other stroke subtypes in 15%. Several clinical features are more frequent in patients with pure motor stroke than in patients

  9. Adiabatic expansion of a strongly correlated pure electron plasma

    SciTech Connect

    Dubin, D.H.E.; O'Neil, T.M.

    1986-02-17

    Adiabatic expansion is proposed as a method of increasing the degree of correlation of a magnetically confined pure electron plasma. Quantum mechanical effects and correlation effects make the physics of the expansion quite different from that for a classical ideal gas. The proposed expansion may be useful in a current experimental effort to cool a pure electron plasma to the liquid and solid (crystalline) states.

  10. Adiabatic expansion of a strongly correlated pure electron plasma

    NASA Astrophysics Data System (ADS)

    Dubin, D. H. E.; Oneil, T. M.

    1986-02-01

    Adiabatic expansion is proposed as a method of increasing the degree of correlation of a magnetically confined pure electron plasma. Quantum mechanical effects and correlation effects make the physics of the expansion quite different from that for a classical ideal gas. The proposed expansion may be useful in a current experimental effort to cool a pure electron plasma to the liquid and solid (crystalline) states.

  11. Hybrids, pure cultures, and pure lines: from nineteenth-century biology to twentieth-century genetics.

    PubMed

    Müller-Wille, Staffan

    2007-12-01

    Prompted by recent recognitions of the omnipresence of horizontal gene transfer among microbial species and the associated emphasis on exchange, rather than isolation, as the driving force of evolution, this essay will reflect on hybridization as one of the central concerns of nineteenth-century biology. I will argue that an emphasis on horizontal exchange was already endorsed by 'biology' when it came into being around 1800 and was brought to full fruition with the emergence of genetics in 1900. The true revolution in nineteenth-century life sciences, I maintain, consisted in a fundamental shift in ontology, which eroded the boundaries between individual and species, and allowed biologists to move up and down the scale of organic complexity. Life became a property extending both 'downwards', to the parts that organisms were composed of, as well as 'upwards', to the collective entities constituted by the relations of exchange and interaction that organisms engage in to reproduce. This mode of thinking was crystallized by Gregor Mendel and consolidated in the late nineteenth-century conjunction of biochemistry, microbiology and breeding in agro-industrial settings. This conjunction and its implications are especially exemplified by Wilhelm Johannsen's and Martinus Beijerinck's work on pure lines and cultures. An understanding of the subsequent constraints imposed by the evolutionary synthesis of the twentieth century on models of genetic systems may require us to rethink the history of biology and displace Darwin's theory of natural selection from that history's centre. PMID:18053934

  12. Pure-tone birdsong by resonance filtering of harmonic overtones

    PubMed Central

    Beckers, Gabriël J. L.; Suthers, Roderick A.; Cate, Carel ten

    2003-01-01

    Pure-tone song is a common and widespread phenomenon in birds. The mechanistic origin of this type of phonation has been the subject of long-standing discussion. Currently, there are three hypotheses. (i) A vibrating valve in the avian vocal organ, the syrinx, generates a multifrequency harmonic source sound, which is filtered to a pure tone by a vocal tract filter (“source-filter” model, analogous to human speech production). (ii) Vocal tract resonances couple with a vibrating valve source, suppressing the normal production of harmonic overtones at this source (“soprano” model, analogous to human soprano singing). (iii) Pure-tone sound is produced as such by a sound-generating mechanism that is fundamentally different from a vibrating valve. Here we present direct evidence of a source-filter mechanism in the production of pure-tone birdsong. Using tracheal thermistors and air sac pressure cannulae, we recorded sound signals close to the syringeal sound source during spontaneous, pure-tone vocalizations of two species of turtledove. The results show that pure-tone dove vocalizations originate through filtering of a multifrequency harmonic sound source. PMID:12764226

  13. Pure and Sr(II)-added copper aluminate nanocomposites: structural, electrical and alcohol sensing studies.

    PubMed

    Kumar, R Thinesh; Vijaya, J Judith; Kennedy, L John

    2013-08-01

    The effect of ethylenediamine addition in the sol-gel method for the preparation of pure and Sr(II)-added nano copper aluminate (CuAl2O4) composites for the enhancement in their structural, electrical, and alcohol sensing properties were investigated. The effect of addition of Sr(II) to pure CuAl2O4 in both the methods were also discussed. X-ray diffraction, scanning electron microscopy, nitrogen adsorption/desorption isotherms, temperature dependant conductance measurements and thermoelectric power measurements were used to characterize the composites prepared. Among the composites, 0.8 molar ratio strontium added copper aluminate composite prepared by modified sol-gel method showed the highest sensitivity towards alcohols. The stability, response and recovery of MS-CuSA5 were also discussed. The response and recovery characteristics showed that the order of sensing alcohols by the composites was butanol > isopropanol > ethanol > methanol, which could be explained on the basis of oxidation of alcohols.

  14. Constitutive modeling of a commercially pure titanium: validation using bulge tests

    NASA Astrophysics Data System (ADS)

    Revil-Baudard, Benoit; Massoni, Elisabeth

    2016-08-01

    In this paper, mechanical tests aimed at characterizing the plastic anisotropy of a commercially pure α-titanium sheet are presented. Hemispheric and elliptic bulge tests conducted to investigate the forming properties of the material are also reported. To model the particularities of the plastic response of the material the classical Hill [1] yield criterion, and Cazacu et al. [2] yield criterion are used. Identification of the material parameters involved in both criteria is based only on uniaxial test data, while their predictive capabilities are assessed through comparison with the bulge tests data. Both models reproduce qualitatively the experimental plastic strain distribution and the final thickness of the sheet. However, only Cazacu et al. [2] yield criterion, which accounts for both the anisotropy and tension-compression asymmetry of the material captures correctly plastic strain localization, in particular its directionality. Furthermore, it is shown that accounting for the strong tension-compression asymmetry in the model formulation improves numerical predictions regarding the mechanical behavior close to fracture of a commercially pure titanium alloy under sheet metal forming processes.

  15. Deterministic LOCC transformation of three-qubit pure states and entanglement transfer

    SciTech Connect

    Tajima, Hiroyasu

    2013-02-15

    A necessary and sufficient condition of the possibility of a deterministic local operations and classical communication (LOCC) transformation of three-qubit pure states is given. The condition shows that the three-qubit pure states are a partially ordered set parametrized by five well-known entanglement parameters and a novel parameter; the five are the concurrences C{sub AB}, C{sub AC}, C{sub BC}, the tangle {tau}{sub ABC} and the fifth parameter J{sub 5} of Acin et al. (2000) Ref. [19], while the other new one is the entanglement charge Q{sub e}. The order of the partially ordered set is defined by the possibility of a deterministic LOCC transformation from a state to another state. In this sense, the present condition is an extension of Nielsen's work (Nielsen (1999) [14]) to three-qubit pure states. We also clarify the rules of transfer and dissipation of the entanglement which is caused by deterministic LOCC transformations. Moreover, the minimum number of times of measurements to reproduce an arbitrary deterministic LOCC transformation between three-qubit pure states is given. - Highlights: Black-Right-Pointing-Pointer We obtained a necessary and sufficient condition for deterministic LOCC of 3 qubits. Black-Right-Pointing-Pointer We clarified rules of entanglement flow caused by measurements. Black-Right-Pointing-Pointer We found a new parameter which is interpreted as 'Charge of Entanglement'. Black-Right-Pointing-Pointer We gave a set of entanglements which determines whether two states are LU-eq. or not. Black-Right-Pointing-Pointer Our approach to deterministic LOCC of 3 qubits may be applicable to N qubits.

  16. High-pressure synthesis of pure and doped superconducting MgB2 compounds

    NASA Astrophysics Data System (ADS)

    Toulemonde, P.; Musolino, N.; Flükiger, R.

    2003-02-01

    Superconducting properties of bulk, dense, pure MgB2 and doped (Mg1-xAx)B2 samples with A = Na, Ca, Cu, Ag, Zn and Al were studied for compositional ranges 0 < x leq 0.20. The effects on pinning properties and critical current were investigated, particularly for A = aluminium. The samples were sintered and/or synthesized at high pressure-high temperature in a cubic multi-anvil press (typically 3.5-6 GPa, 900-1000 °C). They were characterized by x-ray diffraction, scanning electron microscopy and their superconducting properties were investigated by ac susceptibility, magnetization (VSM and SQUID) and transport measurements under a magnetic field. Only Al really substitutes on the Mg site. The other elements form secondary phases with B or Mg which do not act as pinning centres. No positive effect is observed on the superconducting properties of the bulk MgB2 samples with these doping elements added: Tc, critical current jc, Hirr and Hc2. For Al, the effect on Hc2 remains small, and the irreversibility line does not move, thus not improving the critical current of the Al-doped MgB2 samples.

  17. Ultrasonic ablation as a novel technique for producing pure aluminium nanoparticles dispersed in different liquids for different applications

    NASA Astrophysics Data System (ADS)

    Ismail, Yasser A. M.; Kishi, Naoki; Soga, Tetsuo

    2015-07-01

    In this paper, we introduce a novel physical method for producing surfactant-free aluminium nanoparticles (Al NPs) by irradiating ultrasonic waves on Al thin films immersed in different liquids used for different applications. We suggest naming this technique “ultrasonic ablation”. Our method has many advantages compared with other chemical and physical methods such as (1) fabrication of Al NPs using low-cost and easy procedures, (2) fabrication of pure Al NPs without any chemical additives, (3) fabrication of Al NPs dispersed in different liquids used for different applications, and (4) fabrication of individual Al NPs without aggregations. We have prepared Al NPs in 1,2-dichlorobenzene, which is used as a solvent for preparing active layer solutions of organic solar cells (OSCs), poly(3,4-ethylenedioxythiophene)-blend-poly(styrene sulfonate) (PEDOT:PSS), which is a representative aqueous solution used as a buffer layer in OSCs, and ethanol, which is a representative polar solvent used for different applications. Scanning electron microscopy (SEM) and optical absorption techniques have verified the fabrication of individual and surfactant-free Al NPs dispersed in different liquids that can be safely used in different applications.

  18. Extraction of distance restraints from pure shift NOE experiments

    NASA Astrophysics Data System (ADS)

    Kaltschnee, Lukas; Knoll, Kevin; Schmidts, Volker; Adams, Ralph W.; Nilsson, Mathias; Morris, Gareth A.; Thiele, Christina M.

    2016-10-01

    NMR techniques incorporating pure shift methods to improve signal resolution have recently attracted much attention, owing to their potential use in studies of increasingly complex molecular systems. Extraction of frequencies from these simplified spectra enables easier structure determination, but only a few of the methods presented provide structural parameters derived from signal integral measurements. In particular, for quantification of the nuclear Overhauser effect (NOE) it is highly desirable to utilize pure shift techniques where signal overlap normally prevents accurate signal integration, to enable measurement of a larger number of interatomic distances. However, robust methods for the measurement of interatomic distances using the recently developed pure shift techniques have not been reported to date. In this work we discuss some of the factors determining the accuracy of measurements of signal integrals in interferogram-based Zangger-Sterk (ZS) pure shift NMR experiments. The ZS broadband homodecoupling technique is used in different experiments designed for quantitative NOE determination from pure shift spectra. It is shown that the techniques studied can be used for quantitative extraction of NOE-derived distance restraints, as exemplified for the test case of strychnine.

  19. Synthesis of core–shell AlOOH hollow nanospheres by reacting Al nanoparticles with water

    NASA Astrophysics Data System (ADS)

    Lozhkomoev, A. S.; Glazkova, E. A.; Bakina, O. V.; Lerner, M. I.; Gotman, I.; Gutmanas, E. Y.; Kazantsev, S. O.; Psakhie, S. G.

    2016-05-01

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers.

  20. Synthesis of core-shell AlOOH hollow nanospheres by reacting Al nanoparticles with water

    NASA Astrophysics Data System (ADS)

    Lozhkomoev, A. S.; Glazkova, E. A.; Bakina, O. V.; Lerner, M. I.; Gotman, I.; Gutmanas, E. Y.; Kazantsev, S. O.; Psakhie, S. G.

    2016-05-01

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers.

  1. Synthesis of core-shell AlOOH hollow nanospheres by reacting Al nanoparticles with water.

    PubMed

    Lozhkomoev, A S; Glazkova, E A; Bakina, O V; Lerner, M I; Gotman, I; Gutmanas, E Y; Kazantsev, S O; Psakhie, S G

    2016-05-20

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers. PMID:27053603

  2. Al-matrix composite materials reinforced by Al-Cu-Fe particles

    NASA Astrophysics Data System (ADS)

    Bonneville, J.; Laplanche, G.; Joulain, A.; Gauthier-Brunet, V.; Dubois, S.

    2010-07-01

    Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal ω-Al00.70Cu0.20Fe0.10 crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/ω, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particul ar in yield stress values. In the low temperatureregime (T <= 570K), the yield stress of the Al/ω composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

  3. The neuroanatomy of pure apraxia of speech in stroke

    PubMed Central

    Graff-Radford, Jonathan; Jones, David T.; Strand, Edythe A.; Rabinstein, Alejandro A.; Duffy, Joseph R.; Josephs, Keith A.

    2014-01-01

    The left insula or Broca’s area have been proposed as the neuroanatomical correlate for apraxia of speech (AOS) based on studies of patients with both AOS and aphasia due to stroke. Studies of neurodegenerative AOS suggest the premotor area and the supplementary motor areas as the anatomical correlates. The study objective was to determine the common infarction area in patients with pure AOS due to stroke. Patients with AOS and no or equivocal aphasia due to ischemic stroke were identified through a pre-existing database. Seven subjects were identified. Five had pure AOS, and two had equivocal aphasia. MRI lesion analysis revealed maximal overlap spanning the left premotor and motor cortices. While both neurodegenerative AOS and stroke induced pure AOS involve the premotor cortex, further studies are needed to establish whether stroke-induced AOS and neurodegenerative AOS share a common anatomic substrate. PMID:24556336

  4. Excitation of coherent propagating spin waves by pure spin currents

    PubMed Central

    Demidov, Vladislav E.; Urazhdin, Sergei; Liu, Ronghua; Divinskiy, Boris; Telegin, Andrey; Demokritov, Sergej O.

    2016-01-01

    Utilization of pure spin currents not accompanied by the flow of electrical charge provides unprecedented opportunities for the emerging technologies based on the electron's spin degree of freedom, such as spintronics and magnonics. It was recently shown that pure spin currents can be used to excite coherent magnetization dynamics in magnetic nanostructures. However, because of the intrinsic nonlinear self-localization effects, magnetic auto-oscillations in the demonstrated devices were spatially confined, preventing their applications as sources of propagating spin waves in magnonic circuits using these waves as signal carriers. Here, we experimentally demonstrate efficient excitation and directional propagation of coherent spin waves generated by pure spin current. We show that this can be achieved by using the nonlocal spin injection mechanism, which enables flexible design of magnetic nanosystems and allows one to efficiently control their dynamic characteristics. PMID:26818232

  5. The neuroanatomy of pure apraxia of speech in stroke.

    PubMed

    Graff-Radford, Jonathan; Jones, David T; Strand, Edythe A; Rabinstein, Alejandro A; Duffy, Joseph R; Josephs, Keith A

    2014-02-01

    The left insula or Broca's area have been proposed as the neuroanatomical correlate for apraxia of speech (AOS) based on studies of patients with both AOS and aphasia due to stroke. Studies of neurodegenerative AOS suggest the premotor area and the supplementary motor areas as the anatomical correlates. The study objective was to determine the common infarction area in patients with pure AOS due to stroke. Patients with AOS and no or equivocal aphasia due to ischemic stroke were identified through a pre-existing database. Seven subjects were identified. Five had pure AOS, and two had equivocal aphasia. MRI lesion analysis revealed maximal overlap spanning the left premotor and motor cortices. While both neurodegenerative AOS and stroke induced pure AOS involve the premotor cortex, further studies are needed to establish whether stroke-induced AOS and neurodegenerative AOS share a common anatomic substrate. PMID:24556336

  6. Fast word reading in pure alexia: "fast, yet serial".

    PubMed

    Bormann, Tobias; Wolfer, Sascha; Hachmann, Wibke; Neubauer, Claudia; Konieczny, Lars

    2015-01-01

    Pure alexia is a severe impairment of word reading in which individuals process letters serially with a pronounced length effect. Yet, there is considerable variation in the performance of alexic readers with generally very slow, but also occasionally fast responses, an observation addressed rarely in previous reports. It has been suggested that "fast" responses in pure alexia reflect residual parallel letter processing or that they may even be subserved by an independent reading system. Four experiments assessed fast and slow reading in a participant (DN) with pure alexia. Two behavioral experiments investigated frequency, neighborhood, and length effects in forced fast reading. Two further experiments measured eye movements when DN was forced to read quickly, or could respond faster because words were easier to process. Taken together, there was little support for the proposal that "qualitatively different" mechanisms or reading strategies underlie both types of responses in DN. Instead, fast responses are argued to be generated by the same serial-reading strategy.

  7. Noninformative prior in the quantum statistical model of pure states

    NASA Astrophysics Data System (ADS)

    Tanaka, Fuyuhiko

    2012-06-01

    In the present paper, we consider a suitable definition of a noninformative prior on the quantum statistical model of pure states. While the full pure-states model is invariant under unitary rotation and admits the Haar measure, restricted models, which we often see in quantum channel estimation and quantum process tomography, have less symmetry and no compelling rationale for any choice. We adopt a game-theoretic approach that is applicable to classical Bayesian statistics and yields a noninformative prior for a general class of probability distributions. We define the quantum detection game and show that there exist noninformative priors for a general class of a pure-states model. Theoretically, it gives one of the ways that we represent ignorance on the given quantum system with partial information. Practically, our method proposes a default distribution on the model in order to use the Bayesian technique in the quantum-state tomography with a small sample.

  8. Faithful Transfer Arbitrary Pure States with Mixed Resources

    NASA Astrophysics Data System (ADS)

    Luo, Ming-Xing; Li, Lin; Ma, Song-Ya; Chen, Xiu-Bo; Yang, Yi-Xian

    2013-09-01

    In this paper, we show that some special mixed quantum resource experience the same property of pure entanglement such as Bell state for quantum teleportation. It is shown that one mixed state and three bits of classical communication cost can be used to teleport one unknown qubit compared with two bits via pure resources. The schemes are easily implement with model physical techniques. Moreover, these resources are also optimal and typical for faithfully remotely prepare an arbitrary qubit, two-qubit and three-qubit states with mixed quantum resources. Our schemes are completed as same as those with pure quantum entanglement resources except only 1 bit additional classical communication cost required. The success probability is independent of the form of the mixed resources.

  9. Fisher-Symmetric Informationally Complete Measurements for Pure States.

    PubMed

    Li, Nan; Ferrie, Christopher; Gross, Jonathan A; Kalev, Amir; Caves, Carlton M

    2016-05-01

    We introduce a new kind of quantum measurement that is defined to be symmetric in the sense of uniform Fisher information across a set of parameters that uniquely represent pure quantum states in the neighborhood of a fiducial pure state. The measurement is locally informationally complete-i.e., it uniquely determines these parameters, as opposed to distinguishing two arbitrary quantum states-and it is maximal in the sense of a multiparameter quantum Cramér-Rao bound. For a d-dimensional quantum system, requiring only local informational completeness allows us to reduce the number of outcomes of the measurement from a minimum close to but below 4d-3, for the usual notion of global pure-state informational completeness, to 2d-1. PMID:27203310

  10. Actuating dielectric elastomers in pure shear deformation by elastomeric conductors

    SciTech Connect

    Wang, Yin; Chen, Baohong; Zhou, Jinxiong; Bai, Yuanyuan; Wang, Hong

    2014-02-10

    Pure shear experiments are commonly used to characterize dielectric elastomer (DE) material properties and to evaluate DE actuator/generator performance. It is increasingly important for many applications to replace conventional carbon grease electrodes with stretchable elastomeric conductors. We formulate a theory for DE with elastomeric conductors, synthesize transparent hydrogel as ionic conductors, and measure actuation of DE in pure shear deformation. Maximum 67% actuation strain is demonstrated. The theory agrees well with our measurement and also correlates well with reported experiments on DE with electronic conductors.

  11. Six open string disk amplitude in pure spinor superspace

    NASA Astrophysics Data System (ADS)

    Mafra, Carlos R.; Schlotterer, Oliver; Stieberger, Stephan; Tsimpis, Dimitrios

    2011-05-01

    The tree-level amplitude of six massless open strings is computed using the pure spinor formalism. The OPE poles among integrated and unintegrated vertices can be efficiently organized according to the cohomology of pure spinor superspace. The identification and use of these BRST structures and their interplay with the system of equations fulfilled by the generalized Euler integrals allow the full supersymmetric six-point amplitude to be written in compact form. Furthermore, the complete set of extended Bern-Carrasco-Johansson relations are derived from the monodromy properties of the disk world-sheet and explicitly verified for the supersymmetric numerator factors.

  12. PURE CULTIVATION IN VIVO OF VACCINE VIRUS FREE FROM BACTERIA

    PubMed Central

    Noguchi, Hideyo

    1915-01-01

    Vaccine virus freed from all associated bacteria by means of suitable disinfecting agents can be propagated in a pure state in the testicles of rabbits and bulls. The virus cultivated in this manner is not only devoid of all bacteria, but appears capable of indefinite transfer from one animal to another. Sixty passages in rabbits of a pure strain have been made within one year. Several transfers from testicle to testicle are required to bring about accurate adaptation of the virus to the testicular parenchyma, so that continued propagation in this way can be certainly secured. During the first transfers from testicle to testicle the activity of the virus may be less than the original skin specimen from which the pure strain was derived; but as the transfers proceed the activity rises until, when the adaptation is complete, the activity of the testicular equals that of the skin strain. The multiplication of the virus within the testicle is maximum on the fourth or fifth day after inoculation; the quantity of virus remains about stationary until the eighth day, when diminution begins. At the expiration of five weeks no more virus could be detected in the testicle. The vaccinal processes in the skin, cornea, and testicle of rabbits are practically identical whether the virus employed for the inoculation has been the original skin strain or the pure testicular strain; and the skin lesions produced in the calf with the two strains are also identical. In conformity with the finding mentioned in the last paragraph it has been found that human beings react to the pure testicular strain of vaccine virus in an entirely typical manner. In the case both of original vaccination and revaccination the vaccinal effects cannot be distinguished from those arising from uncomplicated skin virus. Pure strains of testicular virus are readily produced, and once secured they may be propagated in a pure state by the method described in rabbits or bulls without difficulty and with economy

  13. Clinical study of 222 patients with pure motor stroke

    PubMed Central

    Arboix, A; Padilla, I; Massons, J; Garcia-Eroles, L; Comes, E; Targa, C

    2001-01-01

    The objective was to assess the frequency of pure motor stroke caused by different stroke subtypes and to compare demographic, clinical, neuroimaging, and outcome data of pure motor stroke with those of patients with other lacunar stroke as well as with those of patients with non-lacunar stroke.
Data from 2000 patients with acute stroke (n=1761) or transient ischaemic attack (n=239) admitted consecutively to the department of neurology of an acute care 350 bed teaching hospital were prospectively collected in the Sagrat Cor Hospital of Barcelona stroke registry over a 10 year period. For the purpose of the study 222 (12.7%) patients with pure motor stroke were selected. The other study groups included 218 (12.3%) patients with other lacunar strokes and 1321 (75%) patients with non-lacunar stroke.
In relation to stroke subtype, lacunar infarcts were found in 189 (85%) patients, whereas ischaemic lacunar syndromes not due to lacunar infarcts occurred in 23 (10.4%) patients (atherothrombotic stroke in 12, cardioembolic stroke in seven, infarction of undetermined origin in three, and infarction of unusual aetiology in one) and haemorrhagic lacunar syndromes in 10 (4.5%). Patients with pure motor stroke showed a better outcome than patients with non-lacunar stroke with a significantly lower number of complications and in hospital mortality rate, shorter duration of hospital stay, and a higher number of symptom free patients at hospital discharge. After multivariate analysis, hypertension, diabetes, obesity, hyperlipidaemia, non-sudden stroke onset, internal capsule involvement, and pons topography seemed to be independent factors of pure motor stroke in patients with acute stroke.
In conclusion, about one of every 10 patients with acute stroke had a pure motor stroke. Pure motor stroke was caused by a lacunar infarct in 85% of patients and by other stroke subtypes in 15%. Several clinical features are more frequent in patients with pure motor stroke than in

  14. Pure tone audiometry: comparison of general practice and hospital services

    PubMed Central

    Smith, Michael C.F.; Cable, Hugh R.; Wilmot, John F.

    1988-01-01

    Pure tone audiometry was obtained for both ears of 32 children by a general practitioner using a simple audiometer in his surgery, and by audiometricians in a hospital department on the same day. Comparing the worst hearing threshold at any of the three tested frequencies, the general practitioner did not find any ears to hear more than 10 dB better than the hospital (no false negatives). However, there were six false positives (9%) where the general practitioner identified an apparent hearing loss of greater than 15 dB. It is concluded that pure tone audiometry could be carried out accurately in the practice. PMID:3267745

  15. Pressure-induced structural phase transition in AlN:Mg and AlN:Co nanowires

    SciTech Connect

    Xu, Yongsheng; Zhu, Hongyang; Ma, Chunli; Zhu, Pinwen; Cong, Ridong; Wu, Xiaoxin; Gao, Wei; Cui, Qiliang

    2013-06-15

    High-pressure behaviors of AlN:Mg and AlN:Co nanowires have been investigated by in situ angle dispersive synchrotron X-ray diffraction up to 41.5 GPa and 38.2 GPa, respectively. Their corresponding pressure-induced wurtzite-to-rocksalt phase transitions start at 17.7 GPa and 15.0 GPa and complete at 33.2 GPa and 31.0 GPa, respectively. The phase-transition routes are not affected by the doped ions, while the phase transition pressures are lower than that of pure AlN nanowires. The distinct high-pressure behaviors are ascribed to the doped ions, which reduce the formation energy of cation vacancies and induce Al vacancies defects together with substitution defects, resulting in lattice distortion and affecting structural stability and phase transition pressure. - Graphical abstract: The high-pressure behaviors of AlN:Mg and AlN:Co nanowires have been investigated by in situ angle dispersive synchrotron X-ray diffraction. - Highlights: • The high-pressure behaviors of AlN:Mg and AlN:Co nanowires have been investigated. • The pressure-induced wurtzite-to-rocksalt phase transitions have been observed. • The phase transition pressures are lower than that of pure AlN nanowires. • The distinct high-pressure behaviors are ascribed to the dopants. • The vacancy defects and substitution defects influence structural stability.

  16. Structural, electronic and magnetic properties of pure metallic and bimetallic nanoclusters: Empirical and density functional studies

    NASA Astrophysics Data System (ADS)

    Hijazi, Iyad Ahmed

    This thesis is aimed at investigating structural, electronic and magnetic properties of metallic/bimetallic nanoclusters. First, a simple empirical embedded-atom potential (EAM) that includes a long range force is developed for FCC metals and alloys. The proposed potential for pure metals does not require modification of the initial function form when being applied to alloy systems. The potential parameters are determined by fitting lattice constant, three elastic constants, cohesive energy, and vacancy formation energies of the pure metals, and the heats of solution of the binary alloys via an optimization technique. Parameters for Ag, Al, Au, Cu, Ni, Pd and Pt have been obtained and used to calculate the bulk modulus, divacancy formation energy, crystal stability, stacking fault energy, vacancy migration energy, and melting point for each pure metal and the heats of formation and lattice constants for binary alloys. The predicted values are in good agreement with experimental results. Structural stabilities and energetics for Cu and Au clusters with up to 56 atoms were also studied using a hierarchical search method. The method employed an effective Monte Carlo (MC) simulated annealing method, utilizing our EAM potential, to identify low-lying structures. In general agreement with previous empirical studies, the lowest-energy copper structures adapt a single icosahedral structural motif. However, contrary to studies that describe gold as less symmetric, this work demonstrates that gold clusters adapt both an icosahedral and icositetrahedral structural motifs with many clusters having symmetric geometries. The structures of the lowest-energy isomers were later optimized using Density Functional Theory (DFT) simulations, and compared to those of available clusters from previous studies. Their lowest-energy structures are mostly found in our pool of isomers, identified by the present method. Our results are in agreement with or lower in energy than existing ab

  17. Interdiffusion in the Mg-Al system and Intrinsic Diffusion in (Al3Mg2) Phase

    SciTech Connect

    Brennan, Sarah; Bermudez, Katrina; Kulkarni, Nagraj S; Sohn, Yong Ho

    2011-01-01

    Increasing use and development of lightweight Mg-alloys have led to the desire for more fundamental research in and understanding of Mg-based systems. As a strengthening component, Al is one of the most important and common alloying elements for Mg-alloys. In this study, solid-to-solid diffusion couple techniques were employed to examine the interdiffusion between pure Mg and Al. Diffusion anneals were carried out at 300 , 350 , and 400 C for 720, 360, and 240 hours, respectively. Optical and scanning electron microscopies (SEM) were employed to observe the formation of the intermetallics -Al12Mg17 and -Al3Mg2, but not -phase. Concentration profiles were determined using X-ray energy dispersive spectroscopy (XEDS). The growth constants and activation energies were determined for each intermetallic phase.

  18. Preparation and initial characterization of fluidized bed steam reforming pure-phase standards

    SciTech Connect

    Missimer, D. M.; Rutherford, R. L.

    2013-03-21

    Hanford is investigating the Fluidized Bed Steam Reforming (FBSR) process for their Low Activity Waste. The FBSR process offers a low-temperature continuous method by which liquid waste can be processed with the addition of clay into a sodium aluminosilicate (NAS) waste form. The NAS waste form is mainly comprised of nepheline (NaAlSiO{sub 4}), sodalite (Na{sub 8}[AlSiO{sub 4}]{sub 6}Cl{sub 2}), and nosean (Na{sub 8}[AlSiO{sub 4}]{sub 6}SO{sub 4}). Anions such as perrhenate (ReO{sub 4}{sup -}), pertechnetate (TcO{sub 4}{sup -}), and iodine (I{sup -}) are expected to replace sulfate in the nosean structure and/or chloride in the sodalite mineral structure (atomically bonded inside the aluminosilicate cages that these mineral structures possess). In the FBSR waste form, each of these phases can exist in a variety of solid solutions that differ from the idealized forms observed in single crystals in nature. The lack of understanding of the durability of these stoichiometric or idealized mineral phases complicates the ability to deconvolute the durability of the mixed phase FBSR product since it is a combination of different NAS phases. To better understand the behavior, fabrication and testing of the individual phases of the FBSR product is required. Analytical Development (AD) of the Science and Technology directorate of the Savannah River National Laboratory (SRNL) was requested to prepare the series of phase-pure standards, consisting of nepheline, nosean, and Cl, Re, and I sodalite. Once prepared, X-ray Diffraction (XRD) analyses were used to confirm the products were phase pure. These standards are being used for subsequent characterization studies consisting of the following: single-pass flow-through (SPFT) testing, development of thermodynamic data, and x-ray diffraction (XRD) calibration curves. In addition to the above mentioned phase-pure standards, AD was tasked with fabricating a mixed Tc-Re sodalite.

  19. Similarities and differences between learning abilities, "pure" learning disabilities, "pure" ADHD and comorbid ADHD with learning disabilities.

    PubMed

    Mangina, Constantine A; Beuzeron-Mangina, Helen

    2009-08-01

    This research pursues the crucial question of the differentiation of preadolescents with "Pure" ADHD, comorbid ADHD with learning disabilities, "Pure" learning disabilities and age-matched normal controls. For this purpose, Topographic Mapping of Event-Related Brain Potentials (ERPs) to a Memory Workload Paradigm with visually presented words, Bilateral Electrodermal Activity during cognitive workload and Mangina-Test performance were used. The analysis of Topographic distribution of amplitudes revealed that normal preadolescents were significantly different from "Pure" ADHD (P<0.0001), "Pure" learning disabilities (P<0.0001), and comorbid ADHD with learning disabilities (P<0.0009), by displaying enhanced prefrontal and frontal negativities (N450). In contrast, preadolescents with "Pure" ADHD and comorbid ADHD with learning disabilities have shown a marked reduction of prefrontal and frontal negativities (N450). As for the "Pure" Learning Disabled preadolescents, very small positivities (P450) in prefrontal and frontal regions were obtained as compared to the other pathological groups. Bilateral Electrodermal Activity during cognitive workload revealed a significant main effect for groups (P<0.00001), Left versus Right (P=0.0029) and sessions (P=0.0136). A significant main effect for the Mangina-Test performance which separated the four groups was found (P<0.000001). Overall, these data support the existence of clear differences and similarities between the pathological preadolescent groups as opposed to age-matched normal controls. The psychophysiological differentiation of these groups, provides distinct biological markers which integrate central, autonomic and neuropsychometric variables by targeting the key features of these pathologies for diagnosis and intervention strategies and by providing knowledge for the understanding of normal neurocognitive processes and functions.

  20. Idealization in Chemistry: Pure Substance and Laboratory Product

    ERIC Educational Resources Information Center

    Fernández-González, Manuel

    2013-01-01

    This article analyzes the concept of idealization in chemistry and the role played by pure substance and laboratory product. This topic has evident repercussions in the educational contexts that are applied to the science classroom, which are highlighted throughout the text. A common structure for knowledge construction is proposed for both…

  1. A Hybrid Sensing Approach for Pure and Adulterated Honey Classification

    PubMed Central

    Subari, Norazian; Saleh, Junita Mohamad; Shakaff, Ali Yeon Md; Zakaria, Ammar

    2012-01-01

    This paper presents a comparison between data from single modality and fusion methods to classify Tualang honey as pure or adulterated using Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA) statistical classification approaches. Ten different brands of certified pure Tualang honey were obtained throughout peninsular Malaysia and Sumatera, Indonesia. Various concentrations of two types of sugar solution (beet and cane sugar) were used in this investigation to create honey samples of 20%, 40%, 60% and 80% adulteration concentrations. Honey data extracted from an electronic nose (e-nose) and Fourier Transform Infrared Spectroscopy (FTIR) were gathered, analyzed and compared based on fusion methods. Visual observation of classification plots revealed that the PCA approach able to distinct pure and adulterated honey samples better than the LDA technique. Overall, the validated classification results based on FTIR data (88.0%) gave higher classification accuracy than e-nose data (76.5%) using the LDA technique. Honey classification based on normalized low-level and intermediate-level FTIR and e-nose fusion data scored classification accuracies of 92.2% and 88.7%, respectively using the Stepwise LDA method. The results suggested that pure and adulterated honey samples were better classified using FTIR and e-nose fusion data than single modality data. PMID:23202033

  2. About the Role of Visual Field Defects in Pure Alexia

    ERIC Educational Resources Information Center

    Pflugshaupt, Tobias; Gutbrod, Klemens; Wurtz, Pascal; von Wartburg, Roman; Nyffeler, Thomas; de Haan, Bianca; Karnath, Hans-Otto; Mueri, Rene M.

    2009-01-01

    Pure alexia is an acquired reading disorder characterized by a disproportionate prolongation of reading time as a function of word length. Although the vast majority of cases reported in the literature show a right-sided visual defect, little is known about the contribution of this low-level visual impairment to their reading difficulties. The…

  3. Computer Pure-Tone and Operator Stress: Report III.

    ERIC Educational Resources Information Center

    Dow, Caroline; Covert, Douglas C.

    Pure-tone sound at 15,750 Herz generated by flyback transformers in many computer and video display terminal (VDT) monitors has stress-related productivity effects in some operators, especially women. College-age women in a controlled experiment simulating half a normal work day showed responses within the first half hour of exposure to a tone…

  4. Effect of dissociation on thermodynamic properties of pure diatomic gases

    NASA Technical Reports Server (NTRS)

    Woolley, Harold W

    1955-01-01

    A graphical method is described by which the enthalpy, entropy, and compressibility factor for the equilibrium mixture of atoms and diatomic molecules for pure gaseous elements may be obtained and shown for any dissociating element for which the necessary data exist. Results are given for hydrogen, oxygen, and nitrogen. The effect of dissociation on the heat capacity is discussed briefly.

  5. Chemical modification of pure titanium surfaces for oral implants.

    PubMed

    Pimenta, J; Castro, F

    1999-01-01

    A technique that achieves different pure titanium surfaces depending on acid concentration and exposure time is described. It is possible to obtain, with the same chemical treatment, both large pits and small rugosities. This technique may have interesting applications in oral implants.

  6. Complex windmill transformation producing new purely magnetic fluids

    NASA Astrophysics Data System (ADS)

    Lozanovski, C.; Wylleman, L.

    2011-04-01

    Minimal complex windmill transformations of G2IB(ii) spacetimes (admitting a two-dimensional Abelian group of motions of the so-called Wainwright B(ii) class) are defined and the compatibility with a purely magnetic Weyl tensor is investigated. It is shown that the transformed spacetimes cannot be perfect fluids or purely magnetic Einstein spaces. We then determine which purely magnetic perfect fluids (PMpfs) can be windmill-transformed into purely magnetic anisotropic fluids (PMafs). Assuming separation of variables, complete integration produces two, algebraically general, G2I-B(ii) PMpfs: a solution with zero 4-acceleration vector and spatial energy-density gradient, previously found by the authors, and a new solution in terms of Kummer's functions, where these vectors are aligned and non-zero. The associated windmill PMafs are rotating but non-expanding. Finally, an attempt to relate the spacetimes to each other by a simple procedure leads to a G2I-B(ii) one-parameter PMaf generalization of the previously found metric.

  7. Pure Mediated Priming: A Retrospective Semantic Matching Model

    ERIC Educational Resources Information Center

    Jones, Lara L.

    2010-01-01

    Mediated priming refers to the activation of a target (e.g., "stripes") by a prime (e.g., "lion") that is related indirectly via a connecting mediator (e.g., tiger). In previous mediated priming studies (e.g., McNamara & Altarriba, 1988), the mediator was associatively related to the prime. In contrast, pure mediated priming (e.g., "spoon" [right…

  8. A pure-sampling quantum Monte Carlo algorithm

    SciTech Connect

    Ospadov, Egor; Rothstein, Stuart M.

    2015-01-14

    The objective of pure-sampling quantum Monte Carlo is to calculate physical properties that are independent of the importance sampling function being employed in the calculation, save for the mismatch of its nodal hypersurface with that of the exact wave function. To achieve this objective, we report a pure-sampling algorithm that combines features of forward walking methods of pure-sampling and reptation quantum Monte Carlo (RQMC). The new algorithm accurately samples properties from the mixed and pure distributions simultaneously in runs performed at a single set of time-steps, over which extrapolation to zero time-step is performed. In a detailed comparison, we found RQMC to be less efficient. It requires different sets of time-steps to accurately determine the energy and other properties, such as the dipole moment. We implement our algorithm by systematically increasing an algorithmic parameter until the properties converge to statistically equivalent values. As a proof in principle, we calculated the fixed-node energy, static α polarizability, and other one-electron expectation values for the ground-states of LiH and water molecules. These quantities are free from importance sampling bias, population control bias, time-step bias, extrapolation-model bias, and the finite-field approximation. We found excellent agreement with the accepted values for the energy and a variety of other properties for those systems.

  9. Pure Spinor Formalism for Osp N\\vert 4) Backgrounds

    NASA Astrophysics Data System (ADS)

    Fré, Pietro; Grassi, Pietro Antonio

    2012-12-01

    We start from the Maurer-Cartan (MC) equations of the Osp(N\\vert 4) superalgebras satisfied by the left-invariant superforms realized on supercoset manifolds of the corresponding supergroups and we derive some new pure spinor constraints. They are obtained by "ghostifying" the MC forms and extending the differential d to a BRST differential. From the superalgebras \\hat G = Osp(N\\vert 4) we single out different subalgebras H \\subset \\hat G associated with the different cosets \\hat {G}/H: each choice of ℍ leads to a different weakening of the pure spinor constraints. In each case, the number of parameter is counted and we show that in the cases of Osp(6|4)/U(3)×SO(1, 3), Osp(4|4)/SO(3) ×SO(1, 3) and finally Osp(4|4)/U(2) ×SO(1, 3) the bosonic and fermionic degrees of freedom match in order to provide a c = 0 superconformal field theory. We construct both the Green-Schwarz and the pure spinor sigma model for the case Osp(6|4)/U(3)×SO(1, 3) corresponding to AdS4 ×ℙ3. The pure spinor sigma model can be consistently quantized.

  10. Number Reading in Pure Alexia--A Review

    ERIC Educational Resources Information Center

    Starrfelt, Randi; Behrmann, Marlene

    2011-01-01

    It is commonly assumed that number reading can be intact in patients with pure alexia, and that this dissociation between letter/word recognition and number reading strongly constrains theories of visual word processing. A truly selective deficit in letter/word processing would strongly support the hypothesis that there is a specialized system or…

  11. Three Variations on a Theme: The Power of Pure Empathy.

    ERIC Educational Resources Information Center

    Kottler, Jeffrey A.; Montgomery, Marilyn J.; Marbley, Aretha Faye

    1998-01-01

    With the counseling profession's increased emphasis on developing brief therapies, applying innovative techniques, and measuring outcomes, helping someone feel understood is sometimes neglected. Three narratives by humanistic practitioners illustrate the value of pure empathy in our work with clients, students, and others in our diverse…

  12. 77 FR 59979 - Pure Magnesium (Granular) From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... this five-year review. Background The Commission instituted this review on February 1, 2012 (77 FR 5049) and determined on May 7, 2012 that it would conduct an expedited review (77 FR 32668, June 1, 2012... COMMISSION Pure Magnesium (Granular) From China Determination On the basis of the record \\1\\ developed in...

  13. In vitro degradation of pure Mg in response to glucose

    PubMed Central

    Zeng, Rong-Chang; Li, Xiao-Ting; Li, Shuo-Qi; Zhang, Fen; Han, En-Hou

    2015-01-01

    Magnesium and its alloys are promising biodegradable biomaterials but are still challenging to be used in person with high levels of blood glucose or diabetes. To date, the influence of glucose on magnesium degradation has not yet been elucidated, this issue requires more attention. Herein, we present pure Mg exhibiting different corrosion responses to saline and Hank’s solutions with different glucose contents, and the degradation mechanism of pure Mg in the saline solution with glucose in comparison with mannitol as a control. On one hand, the corrosion rate of pure Mg increases with the glucose concentration in saline solutions. Glucose rapidly transforms into gluconic acid, which attacks the oxides of the metal and decreases the pH of the solution; it also promotes the absorption of chloride ions on the Mg surface and consequently accelerates corrosion. On the other hand, better corrosion resistance is obtained with increasing glucose content in Hank’s solution due to the fact that glucose coordinates Ca2+ ions in Hank’s solution and thus improves the formation of Ca-P compounds on the pure Mg surface. This finding will open up new avenues for research on the biodegradation of bio-Mg materials in general, which could yield many new and interesting results. PMID:26264413

  14. Molarity (Aromic Density) of the Elements as Pure Crystals.

    ERIC Educational Resources Information Center

    Pauling, Linus; Herman, Zelek S.

    1985-01-01

    Provides background information for teachers on the atomic density of the elements as pure crystals. Atomic density is defined as the reciprocal of the atomic volume. Includes atomic-density diagrams which were prepared using the atomic-volume values given by Singman, supplemented by additional values for some allotropes. (JN)

  15. A Graphical Representation for the Fugacity of a Pure Substance

    ERIC Educational Resources Information Center

    Book, Neil L.; Sitton, Oliver C.

    2010-01-01

    The thermodynamic equations used to define and compute the fugacity of a pure substance are depicted as processes on a semi-logarithmic plot of pressure vs. molar Gibbs energy (PG diagram) with isotherms for the substance behaving as an ideal gas superimposed. The PG diagram clearly demonstrates the physical basis for the definitions and the…

  16. In vitro degradation of pure Mg in response to glucose

    NASA Astrophysics Data System (ADS)

    Zeng, Rong-Chang; Li, Xiao-Ting; Li, Shuo-Qi; Zhang, Fen; Han, En-Hou

    2015-08-01

    Magnesium and its alloys are promising biodegradable biomaterials but are still challenging to be used in person with high levels of blood glucose or diabetes. To date, the influence of glucose on magnesium degradation has not yet been elucidated, this issue requires more attention. Herein, we present pure Mg exhibiting different corrosion responses to saline and Hank’s solutions with different glucose contents, and the degradation mechanism of pure Mg in the saline solution with glucose in comparison with mannitol as a control. On one hand, the corrosion rate of pure Mg increases with the glucose concentration in saline solutions. Glucose rapidly transforms into gluconic acid, which attacks the oxides of the metal and decreases the pH of the solution; it also promotes the absorption of chloride ions on the Mg surface and consequently accelerates corrosion. On the other hand, better corrosion resistance is obtained with increasing glucose content in Hank’s solution due to the fact that glucose coordinates Ca2+ ions in Hank’s solution and thus improves the formation of Ca-P compounds on the pure Mg surface. This finding will open up new avenues for research on the biodegradation of bio-Mg materials in general, which could yield many new and interesting results.

  17. Information balance in quantum teleportation with an arbitrary pure state

    SciTech Connect

    Li Li; Chen Zengbing

    2005-07-15

    We study a general teleportation scheme with an arbitrary two-party pure state and derive a tight bound of the teleportation fidelity with a predesigned estimation of the unknown state to be teleported. This bound shows a piecewise balance between information gain and state disturbance. We also explain possible physical significance of the balance.

  18. A pure-sampling quantum Monte Carlo algorithm

    NASA Astrophysics Data System (ADS)

    Ospadov, Egor; Rothstein, Stuart M.

    2015-01-01

    The objective of pure-sampling quantum Monte Carlo is to calculate physical properties that are independent of the importance sampling function being employed in the calculation, save for the mismatch of its nodal hypersurface with that of the exact wave function. To achieve this objective, we report a pure-sampling algorithm that combines features of forward walking methods of pure-sampling and reptation quantum Monte Carlo (RQMC). The new algorithm accurately samples properties from the mixed and pure distributions simultaneously in runs performed at a single set of time-steps, over which extrapolation to zero time-step is performed. In a detailed comparison, we found RQMC to be less efficient. It requires different sets of time-steps to accurately determine the energy and other properties, such as the dipole moment. We implement our algorithm by systematically increasing an algorithmic parameter until the properties converge to statistically equivalent values. As a proof in principle, we calculated the fixed-node energy, static α polarizability, and other one-electron expectation values for the ground-states of LiH and water molecules. These quantities are free from importance sampling bias, population control bias, time-step bias, extrapolation-model bias, and the finite-field approximation. We found excellent agreement with the accepted values for the energy and a variety of other properties for those systems.

  19. Enzymatic Synthesis of Single-Stranded Clonal Pure Oligonucleotides.

    PubMed

    Ducani, Cosimo; Högberg, Björn

    2017-01-01

    Single-stranded oligonucleotides, or oligodeoxyribonucleotides (ODNs), are very important in several fields of science such as molecular biology, diagnostics, nanotechnology, and gene therapy. They are usually chemically synthesized. Here we describe an enzymatic method which enables us to synthesize pure oligonucleotides which can be up to several hundred long bases. PMID:27671934

  20. Entropy for quantum pure states and quantum H theorem

    NASA Astrophysics Data System (ADS)

    Han, Xizhi; Wu, Biao

    2015-06-01

    We construct a complete set of Wannier functions that are localized at both given positions and momenta. This allows us to introduce the quantum phase space, onto which a quantum pure state can be mapped unitarily. Using its probability distribution in quantum phase space, we define an entropy for a quantum pure state. We prove an inequality regarding the long-time behavior of our entropy's fluctuation. For a typical initial state, this inequality indicates that our entropy can relax dynamically to a maximized value and stay there most of time with small fluctuations. This result echoes the quantum H theorem proved by von Neumann [Zeitschrift für Physik 57, 30 (1929), 10.1007/BF01339852]. Our entropy is different from the standard von Neumann entropy, which is always zero for quantum pure states. According to our definition, a system always has bigger entropy than its subsystem even when the system is described by a pure state. As the construction of the Wannier basis can be implemented numerically, the dynamical evolution of our entropy is illustrated with an example.

  1. A hybrid sensing approach for pure and adulterated honey classification.

    PubMed

    Subari, Norazian; Mohamad Saleh, Junita; Md Shakaff, Ali Yeon; Zakaria, Ammar

    2012-01-01

    This paper presents a comparison between data from single modality and fusion methods to classify Tualang honey as pure or adulterated using Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA) statistical classification approaches. Ten different brands of certified pure Tualang honey were obtained throughout peninsular Malaysia and Sumatera, Indonesia. Various concentrations of two types of sugar solution (beet and cane sugar) were used in this investigation to create honey samples of 20%, 40%, 60% and 80% adulteration concentrations. Honey data extracted from an electronic nose (e-nose) and Fourier Transform Infrared Spectroscopy (FTIR) were gathered, analyzed and compared based on fusion methods. Visual observation of classification plots revealed that the PCA approach able to distinct pure and adulterated honey samples better than the LDA technique. Overall, the validated classification results based on FTIR data (88.0%) gave higher classification accuracy than e-nose data (76.5%) using the LDA technique. Honey classification based on normalized low-level and intermediate-level FTIR and e-nose fusion data scored classification accuracies of 92.2% and 88.7%, respectively using the Stepwise LDA method. The results suggested that pure and adulterated honey samples were better classified using FTIR and e-nose fusion data than single modality data. PMID:23202033

  2. Some Physical Properties of Pure and Doped Polyvinyl Alcohol under Applied Stress

    NASA Astrophysics Data System (ADS)

    Hemeda, O. M.; Hemeda, D. M.; Said, M. Z.

    Thick films of polyvinyl alcohol (PVA) containing very fine metallic powder, copper (Cu), iron (Fe) and aluminum (Al) 2.5% by weight, were prepared by the casting method. The temperature dependence of Young's modulus at constant stress, the stress dependence of Young's modulus (Y), the stress dependence of dielectric constant (ɛ) and stress dependence of phonon velocity, were studied. It was found that Young's modulus (Y) of the pure sample has the lowest value and that of PVA + Al has the highest value. This can be explained on the basis that Y depends on the ratio between the energy of molecular interactions and the energy of thermal motion of the sample units. We also found that the dielectric constant increases with the addition of metallic powder, and with an increasing applied stress. The phonon velocity increased with increasing stress. The increase of stress decreases imperfections leading to the increased phonon velocity. The electronic absorption spectra of PVA is not affected by doping Al and Fe, whereas the PVA doped with Cu shows a shift of the absorption maxima toward a longer wavelength. The instantaneous elastic behavior may be observed only at low temperatures and very short creep times.

  3. Effect of surface treatments on the bond strength of a resin cement to commercially pure titanium.

    PubMed

    de Almeida-Júnior, Antonio Alves; Fonseca, Renata Garcia; Haneda, Isabella Gagliardi; Abi-Rached, Filipe de Oliveira; Adabo, Gelson Luis

    2010-01-01

    Investigation of the effectiveness of surface treatments that promote a strong bond strength of resin cements to metals can contribute significantly to the longevity of metal-ceramic restorations. This study evaluated the effect of surface treatments on the shear bond strength (SBS) of a resin cement to commercially pure titanium (CP Ti). Ninety cast CP Ti discs were divided into 3 groups (n=30), which received one of the following airborne-particle abrasion conditions: (1) 50 microm Al(2)O(3) particles; (2) 30 microm silica-modified Al(2)O(3) particles (Cojet Sand); (3) 110 microm silica-modified Al(2)O(3) particles (Rocatec). For each airborne-particle abrasion condition, the following post-airborne-particle abrasion treatments were used (n=10): (1) none; (2) adhesive Adper Single Bond 2; (3) silane RelyX Ceramic Primer. RelyX ARC resin cement was bonded to CP Ti surfaces. All specimens were thermally cycled before being tested in shear mode. Failure mode was determined. The best association was Rocatec plus silane. All groups showed 100% adhesive failure. There were combinations that promote higher SBS than the protocol recommended by the manufacturer of RelyX ARC. PMID:20640356

  4. Distortion-Product Emissions and Pure-Tone Behavioral Thresholds.

    NASA Astrophysics Data System (ADS)

    Harris, Frances Pauline

    Distortion-product emissions (DPEs) are tonal responses that may be detected in the ear canal when the ear is stimulated simultaneously by two tones that are closely spaced in frequency. In experimental animals, DPEs are reduced in amplitude or are eliminated when cochlear function is disrupted. This association has not been investigated in human subjects. This study was designed to investigate the relation of cochlear status, as determined by pure -tone behavioral thresholds, to DPE amplitude in human subjects. Forty men were selected as subjects. Twenty had normal hearing and 20 had high-frequency sensorineural hearing loss. Pure-tone behavioral thresholds were determined using conventional audiometric procedures for eight frequencies from 750 to 8000 Hz. DPEs were generated in the test ear of each subject by stimulating the ear with two tones, f1 and f2. The stimuli were selected to approximate audiometric test frequencies. Responses were detected by a sensitive microphone that was placed in the ear canal and were extracted by spectral analysis. Results of the study indicated that DPE amplitude was associated with pure-tone threshold. When audiometric threshold was <=10 dB HL, DPEs could be elicited at all test frequencies for 98% of subjects in both groups. Mean maximum emission amplitude ranged from 3 to 13 dB SPL across frequency. When pure-tone threshold was above 50 dB HL, DPEs were absent or were significantly attenuated. DPEs varied in amplitude when audiometric threshold was between these two extremes. The association of DPE amplitude were pure-tone threshold was frequency specific. DPE amplitude was maximal when pure-tone thresholds were <=10 dB HL and decreased as pure-tone behavioral threshold increased in the same subject. Repetition of the DPE protocol with five subjects from each group during separate test sessions indicated that the results were reliable over time. Results of the study have clinical implications. The technique may have potential

  5. Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp

    PubMed Central

    2014-01-01

    Over the last few decades, researchers have developed a number of empirical and theoretical models for the correlation and prediction of the thermophysical properties of pure fluids and mixtures treated as pseudo-pure fluids. In this paper, a survey of all the state-of-the-art formulations of thermophysical properties is presented. The most-accurate thermodynamic properties are obtained from multiparameter Helmholtz-energy-explicit-type formulations. For the transport properties, a wider range of methods has been employed, including the extended corresponding states method. All of the thermophysical property correlations described here have been implemented into CoolProp, an open-source thermophysical property library. This library is written in C++, with wrappers available for the majority of programming languages and platforms of technical interest. As of publication, 110 pure and pseudo-pure fluids are included in the library, as well as properties of 40 incompressible fluids and humid air. The source code for the CoolProp library is included as an electronic annex. PMID:24623957

  6. Laser-induced fluorescence and pure rotational spectroscopy of the CH2CHS (vinylthio) radical.

    PubMed

    Nakajima, Masakazu; Miyoshi, Akira; Sumiyoshi, Yoshihiro; Endo, Yasuki

    2007-01-28

    Laser-induced fluorescence (LIF) excitation spectra of the B-X (2)A(") electronic transition of the CH(2)CHS radical, which is the sulfur analog of the vinoxy (CH(2)CHO) radical, were observed under room temperature and jet-cooled conditions. The LIF excitation spectra show very poor vibronic structures, since the fluorescence quantum yields of the upper vibronic levels are too small to detect fluorescence, except for the vibrationless level in the B state. A dispersed fluorescence spectrum of jet-cooled CH(2)CHS from the vibrationless level of the B state was also observed, and vibrational frequencies in the X state were determined. Precise rotational and spin-rotation constants in the ground vibronic level of the radical were determined from pure rotational spectroscopy using a Fourier-transform microwave (FTMW) spectrometer and a FTMW-millimeter wave double-resonance technique [Y. Sumiyoshi et al., J. Chem. Phys. 123, 054324 (2005)]. The rotationally resolved LIF excitation spectrum for the vibronic origin band of the jet-cooled CH(2)CHS radical was analyzed using the ground state molecular constants determined from pure rotational spectroscopy. Determined molecular constants for the upper and lower electronic states agree well with results of ab initio calculations.

  7. Thin films of pure vanadium nitride: Evidence for anomalous non-faradaic capacitance

    NASA Astrophysics Data System (ADS)

    Bondarchuk, Oleksandr; Morel, Alban; Bélanger, Daniel; Goikolea, Eider; Brousse, Thierry; Mysyk, Roman

    2016-08-01

    An impressive gravimetric capacitance of 1300 F g-1 (surface capacitance ∼3.3 mF cm-2) reported by Choi et al., 2006 for nanosized vanadium nitride has stimulated considerable interest in vanadium nitride as a potential electrode material for energy storing systems - supercapacitors. The postulated mechanism of charge storage in vanadium nitride materials involves redox reactions in the thin surface layer of vanadium oxide while the core vanadium nitride serves exclusively as a conducting platform. In this study we have synthesized pure oxygen-free vanadium nitride films and have found that they are capable of delivering a surface capacitance of up to ∼3 mF cm-2 at a potential scan rate of 3 mV s-1 and ∼2 mF cm-2 at a potential scan rate of 1 V s-1 in aqueous electrolytes. Combining electrochemical testing with X-ray photoelectron spectroscopy characterization has revealed that redox reactions play no or little role in the electrochemical response of pure VN, in contrast to the common wisdom stemming from the electrochemical response of oxygen-containing films. An alternative charge storage mechanism - space charge accumulation in a subsurface layer of ∼100 nm - was put forward to explain the experimentally observed capacitance of VN films in aqueous electrolytes.

  8. Thin films of pure vanadium nitride: Evidence for anomalous non-faradaic capacitance

    NASA Astrophysics Data System (ADS)

    Bondarchuk, Oleksandr; Morel, Alban; Bélanger, Daniel; Goikolea, Eider; Brousse, Thierry; Mysyk, Roman

    2016-08-01

    An impressive gravimetric capacitance of 1300 F g-1 (surface capacitance ∼3.3 mF cm-2) reported by Choi et al., 2006 for nanosized vanadium nitride has stimulated considerable interest in vanadium nitride as a potential electrode material for energy storing systems - supercapacitors. The postulated mechanism of charge storage in vanadium nitride materials involves redox reactions in the thin surface layer of vanadium oxide while the core vanadium nitride serves exclusively as a conducting platform. In this study we have synthesized pure oxygen-free vanadium nitride films and have found that they are capable of delivering a surface capacitance of up to ∼3 mF cm-2 at a potential scan rate of 3 mV s-1 and ∼2 mF cm-2 at a potential scan rate of 1 V s-1 in aqueous electrolytes. Combining electrochemical testing with X-ray photoelectron spectroscopy characterization has revealed that redox reactions play no or little role in the electrochemical response of pure VN, in contrast to the common wisdom stemming from the electrochemical response of oxygen-containing films. An alternative charge storage mechanism - space charge accumulation in a subsurface layer of ∼100 nm - was put forward to explain the experimentally observed capacitance of VN films in aqueous electrolytes.

  9. A class representative model for Pure Parsimony Haplotyping under uncertain data.

    PubMed

    Catanzaro, Daniele; Labbé, Martine; Porretta, Luciano

    2011-01-01

    The Pure Parsimony Haplotyping (PPH) problem is a NP-hard combinatorial optimization problem that consists of finding the minimum number of haplotypes necessary to explain a given set of genotypes. PPH has attracted more and more attention in recent years due to its importance in analysis of many fine-scale genetic data. Its application fields range from mapping complex disease genes to inferring population histories, passing through designing drugs, functional genomics and pharmacogenetics. In this article we investigate, for the first time, a recent version of PPH called the Pure Parsimony Haplotype problem under Uncertain Data (PPH-UD). This version mainly arises when the input genotypes are not accurate, i.e., when some single nucleotide polymorphisms are missing or affected by errors. We propose an exact approach to solution of PPH-UD based on an extended version of Catanzaro et al.[1] class representative model for PPH, currently the state-of-the-art integer programming model for PPH. The model is efficient, accurate, compact, polynomial-sized, easy to implement, solvable with any solver for mixed integer programming, and usable in all those cases for which the parsimony criterion is well suited for haplotype estimation. PMID:21464966

  10. Measurement of 26Al for atmospheric and climate research and the potential of 26Al/ 10Be ratios

    NASA Astrophysics Data System (ADS)

    Auer, M.; Kutschera, W.; Priller, A.; Wagenbach, D.; Wallner, A.; Wild, E. M.

    2007-06-01

    The measurement of the paired cosmogenic radionuclides 26Al and 10Be in environmental samples has potential applications in atmospheric and climate research. For this study, we report the first measurements of the 26Al/10Be atomic ratio in tropospheric aerosol samples from sites in Europe and Antarctica performed at the Vienna Environmental Research Accelerator (VERA). These initial results show that the 26Al/10Be atomic ratio in tropospheric aerosols averages 1.78 × 10-3 and does not vary significantly between the different locations. We also report results of systematic investigations of the ionization and detection efficiency which we performed to improve the measurement precision for 26Al by AMS. Maximum detection efficiencies of up to 9 × 10-4 (in units of 26Al atoms detected/initial) were achieved for chemically pure Al2O3, while for atmospheric samples we reached efficiencies of up to 2.2 × 10-4.

  11. Pure odd-order oscillators with constant excitation

    NASA Astrophysics Data System (ADS)

    Cveticanin, L.

    2011-02-01

    In this paper the excited vibrations of a truly nonlinear oscillator are analyzed. The excitation is assumed to be constant and the nonlinearity is pure (without a linear term). The mathematical model is a second-order nonhomogeneous differential equation with strong nonlinear term. Using the first integral, the exact value of period of vibration i.e., angular frequency of oscillator described with a pure nonlinear differential equation with constant excitation is analytically obtained. The closed form solution has the form of gamma function. The period of vibration depends on the value of excitation and of the order and coefficient of the nonlinear term. For the case of pure odd-order-oscillators the approximate solution of differential equation is obtained in the form of trigonometric function. The solution is based on the exact value of period of vibration. For the case when additional small perturbation of the pure oscillator acts, the so called 'Cveticanin's averaging method' for a truly nonlinear oscillator is applied. Two special cases are considered: one, when the additional term is a function of distance, and the second, when damping acts. To prove the correctness of the method the obtained results are compared with those for the linear oscillator. Example of pure cubic oscillator with constant excitation and linear damping is widely discussed. Comparing the analytically obtained results with exact numerical ones it is concluded that they are in a good agreement. The investigations reported in the paper are of special interest for those who are dealing with the problem of vibration reduction in the oscillator with constant excitation and pure nonlinear restoring force the examples of which can be found in various scientific and engineering systems. For example, such mechanical systems are seats in vehicles, supports for machines, cutting machines with periodical motion of the cutting tools, presses, etc. The examples can be find in electronics

  12. Reply to "on cochlear impedances and the miscomputation of power gain" by Shera et Al. J. Assoc. Re. Otolaryngol.

    PubMed

    Ren, Tianying; He, Wenxuan; Gillespie, Peter G

    2011-12-01

    Using a scanning laser interferometer, we recently measured the volume velocity of the basilar membrane vibration in the sensitive gerbil cochlea and estimated that the cochlear power gain is ~100 at low sound pressure levels (Ren et al., Nat Commun 2:216-223, 2011a). We thank Shera et al. for recognizing the technical challenges of our experiments and appreciating the beauty of our data in their comment (Shera et al., J Assoc Res Otolaryngol (in press), 2011). These authors argue that our analysis is inappropriate, invalidating our conclusion; moreover, they suggest that our finding of a power gain of >1 could arise from a passive structure or cochlea. While our analysis and interpretation remain to be verified, they are justified according to commonly accepted assumptions and theories in cochlear mechanics. Here, we also show that the mathematical demonstration of a power gain of >1 in a passive cochlea by Shera et al. is inconsistent with our data, which show that the volume velocity and power gain decrease and become <1 as the sound level increases. PMID:22015558

  13. Synthesis and Characterization of Pure and Doped Ceria Films by Sol-Gel and Sputtering

    SciTech Connect

    Koch, K.T.; Saraf, L.

    2004-01-01

    Pure and doped Ceria are known for their ability to gain or lose Oxygen, which is of interest to the Solid Oxide Fuel Cell (SOFC) and catalyst community. Current efforts are focused in SOFCs to reduce the operating temperature of the cell while maintaining ionic conduction. Ceria is known for its high ionic conductivity in the intermediate temperature region. (600-800° C) We have prepared pure and doped Ceria films by Sol-gel and magnetron sputtering methods. Enhanced grain-boundary contribution in the conductivity can be studied in the Sol-gel process due to excellent control over the synthesis conditions, which enabled us to control the average grain size. Sputtered films were grown and investigated as a prelude to possible multi-layered CeO2 structures in the near future. These films were characterized by X-ray diffraction (XRD), nuclear reaction analysis (NRA), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and Oxygen conduction measurements. We have observed greater volume diffusion in nanocrystalline Ceria compared to bulk polycrystalline films as a result of low density. Near surface diffusion properties with increasing temperature indicate a decrease in the volume diffusion as a result of grain growth. However, a linear increase in O2 content at ~600nm depth was observed and can be correlated to the redistribution of O2 in the samples. Surface roughness of <111> and <200> oriented Ceria films on Al2O3 and YSZ was observed to be 0.13nm and 0.397nm, respectively. In the case of Ceria grown on YSZ, structural properties from XRD results showed a highly oriented structure with cube on cube growth. XRD results from Ceria grown on Al2O3 showed an oriented structure whose degree of orientation appeared to be partially dependent on substrate temperature. Preliminary XPS results indicate reduction in Ceria from the Ce4+ to Ce3+ state near the surface.

  14. Citrate impairs the micropore diffusion of phosphate into pure and C-coated goethite

    NASA Astrophysics Data System (ADS)

    Mikutta, Christian; Lang, Friederike; Kaupenjohann, Martin

    2006-02-01

    Anions of polycarboxylic low-molecular-weight organic acids (LMWOA) compete with phosphate for sorption sites of hydrous Fe and Al oxides. To test whether the sorption of LMWOA anions decreases the accessibility of micropores (<2 nm) of goethite (α-FeOOH) for phosphate, we studied the kinetics of citrate-induced changes in microporosity and the phosphate sorption kinetics of synthetic goethite in the presence and absence of citrate in batch systems for 3 weeks (500 μM of each ion, pH 5). We also used C-coated goethite obtained after sorption of dissolved organic matter in order to simulate organic coatings in the soil. We analyzed our samples with N 2 adsorption and electrophoretic mobility measurements. Citrate clogged the micropores of both adsorbents by up to 13% within 1 h of contact. The micropore volume decreased with increasing concentration and residence time of citrate. In the absence of citrate, phosphate diffused into micropores of the pure and C-coated goethite. The C coating (5.6 μmol C m -2) did not impair the intraparticle diffusion of phosphate. In the presence of citrate, the diffusion of phosphate into the micropores of both adsorbents was strongly impaired. We attribute this to the micropore clogging and the ligand-induced dissolution of goethite by citrate. While the diffusion limitation of phosphate by citrate was stronger when citrate was added before phosphate to pure goethite, the order of addition of both ions to C-coated goethite had only a minor effect on the intraparticle diffusion of phosphate. Micropore clogging and dissolution of microporous hydrous Fe and Al oxides may be regarded as potential strategies of plants to cope with phosphate deficiency in addition to ligand-exchange.

  15. Thermal durability of AZO/Ag(Al)/AZO transparent conductive films

    NASA Astrophysics Data System (ADS)

    Sugimoto, Yukiko; Igarashi, Kanae; Shirasaki, Shinya; Kikuchi, Akihiko

    2016-04-01

    Effects of Al doping on surface morphology, sheet resistance, optical transmission spectra, and thermal durability of a thin Ag layer and AZO/Ag/AZO dielectric/metal/dielectric (DMD) transparent conductive films (TCFs) were investigated. The 1.7 at. % Al doping suppressed the initial island growth of a thin Ag layer and the plasmon resonant absorption dip in the optical transmission spectra. The threshold thickness of percolation conductivity was reduced from 9-10 (pure Al layer) to 5-6 nm (1.7 at. % Al-doped Ag layer). Al doping in the Ag layer improved the thermal durability of AZO/Ag/AZO-DMD TCFs. The threshold temperature for Ag void formation increased from 400 °C (DMD with pure Ag layer) to 600 °C (DMD with a 10.5 at. % Al-doped Ag layer). The optimum annealing temperature increased from 300 °C (DMD with a pure Ag layer) to 500 °C (DMD with a 10.5 at. % Al-doped Ag layer). Maximum figures of merit (FOM) were 0.5 × 10-2 and 1.1 × 10-2 Ω-1 for the DMD with a pure Ag layer and that with a 10.5 at. % Al-doped Ag layer, respectively.

  16. [Clinical picture of pure corneal ulcers of different localizations].

    PubMed

    Tarasova, L N; Kudriashova, Iu I

    1999-01-01

    Pure corneal ulcers can be localized at the periphery and in the center. Peripheral ulcers are bilateral in 66% and multifocal in 48% cases. They are combined with local vasculitis of perilimbic vessels of the conjunctiva. In 84% cases the disease occurred in patients with connective tissue and articular diseases. Clinical picture of the peripheral corneal ulcer differs from Mourene's phagodenic ulcer. Central corneal ulcers are bilateral in 40% patients, are associated with primary and secondary "dry eye" syndrome in Sjogren's disease, rheumatoid arthritis, systemic vasculitis, Behçet's disease, and in 18% patients with cicatricial deformation of the conjunctiva after Stevens-Johnson's syndrome, trachoma, and chemical burns of the eyes. Pure corneal ulcers run a chronic relapsing course, complicated in one-fourth of patients by corneal perforation and secondary infections.

  17. Biomedical effects of mushrooms with emphasis on pure compounds.

    PubMed

    Paterson, R Russell M; Lima, Nelson

    2014-01-01

    Medicinal mushrooms show great promise for disease treatments. They have been employed in the Orient and Occident for thousands of years, although the practice has persisted in the East. They remain highly valuable. Authentic human trials and pure compounds are emphasized in this review of the most current literature. Polysaccharides from the fungi appear effective in cancer treatments and low-molecular-weight compounds also attract much interest. However, reports of toxicity must be taken seriously. Prescriptions for mushrooms and preparations need to be given by qualified medical practitioners. The reason why these preparations are not more widely used in the West is related to problems of (A) intellectual property rights, (B) mass production, and (C) obtaining pure compounds that retain activity. Mushroom compounds require testing against infectious diseases such as those caused by bacteria, because the current antibiotics are failing from resistances. Overall, the future is assured for medicinal mushrooms.

  18. New Formulation of Statistical Mechanics Using Thermal Pure Quantum States

    NASA Astrophysics Data System (ADS)

    Sugiura, Sho; Shimizu, Akira

    2014-03-01

    We formulate statistical mechanics based on a pure quantum state, which we call a "thermal pure quantum (TPQ) state". A single TPQ state gives not only equilibrium values of mechanical variables, such as magnetization and correlation functions, but also those of genuine thermodynamic variables and thermodynamic functions, such as entropy and free energy. Among many possible TPQ states, we discuss the canonical TPQ state, the TPQ state whose temperature is specified. In the TPQ formulation of statistical mechanics, thermal fluctuations are completely included in quantum-mechanical fluctuations. As a consequence, TPQ states have much larger quantum entanglement than the equilibrium density operators of the ensemble formulation. We also show that the TPQ formulation is very useful in practical computations, by applying the formulation to a frustrated two-dimensional quantum spin system.

  19. Synthesis and photoluminescence of ultra-pure germanium nanoparticles

    NASA Astrophysics Data System (ADS)

    Chivas, R.; Yerci, S.; Li, R.; Dal Negro, L.; Morse, T. F.

    2011-09-01

    We have used aerosol deposition to synthesize defect and micro-strain free, ultra-pure germanium nanoparticles. Transmission electron microscopy images show a core-shell configuration with highly crystalline core material. Powder X-ray diffraction measurements verify the presence of highly pure, nano-scale germanium with average crystallite size of 30 nm and micro-strain of 0.058%. X-ray photoelectron spectroscopy demonstrates that GeO x ( x ⩽ 2) shells cover the surfaces of the nanoparticles. Under optical excitation, these nanoparticles exhibit two separate emission bands at room temperature: a visible emission at 500 nm with 0.5-1 ns decay times and an intense near-infrared emission at 1575 nm with up to ˜20 μs lifetime.

  20. Control aspects of quantum computing using pure and mixed states.

    PubMed

    Schulte-Herbrüggen, Thomas; Marx, Raimund; Fahmy, Amr; Kauffman, Louis; Lomonaco, Samuel; Khaneja, Navin; Glaser, Steffen J

    2012-10-13

    Steering quantum dynamics such that the target states solve classically hard problems is paramount to quantum simulation and computation. And beyond, quantum control is also essential to pave the way to quantum technologies. Here, important control techniques are reviewed and presented in a unified frame covering quantum computational gate synthesis and spectroscopic state transfer alike. We emphasize that it does not matter whether the quantum states of interest are pure or not. While pure states underly the design of quantum circuits, ensemble mixtures of quantum states can be exploited in a more recent class of algorithms: it is illustrated by characterizing the Jones polynomial in order to distinguish between different (classes of) knots. Further applications include Josephson elements, cavity grids, ion traps and nitrogen vacancy centres in scenarios of closed as well as open quantum systems.

  1. Modeling pure culture heterotrophic production of polyhydroxybutyrate (PHB).

    PubMed

    Mozumder, Md Salatul Islam; Goormachtigh, Laurens; Garcia-Gonzalez, Linsey; De Wever, Heleen; Volcke, Eveline I P

    2014-03-01

    In this contribution a mechanistic model describing the production of polyhydroxybutyrate (PHB) through pure-culture fermentation was developed, calibrated and validated for two different substrates, namely glucose and waste glycerol. In both cases, non-growth-associated PHB production was triggered by applying nitrogen limitation. The occurrence of some growth-associated PHB production besides non-growth-associated PHB production was demonstrated, although it is inhibited in the presence of nitrogen. Other phenomena observed experimentally and described by the model included biomass growth on PHB and non-linear product inhibition of PHB production. The accumulated impurities from the waste substrate negatively affected the obtained maximum PHB content. Overall, the developed mathematical model provided an accurate prediction of the dynamic behavior of heterotrophic biomass growth and PHB production in a two-phase pure culture system. PMID:24457311

  2. The formation of blobs from a pure interchange process

    SciTech Connect

    Zhu, P.; Sovinec, C. R.; Hegna, C. C.

    2015-02-15

    In this work, we focus on examining a pure interchange process in a shear-less slab configuration as a prototype mechanism for blob formation. We employ full magnetohydrodynamic simulations to demonstrate that the blob-like structures can emerge through the nonlinear development of a pure interchange instability originating from a pedestal-like transition region. In the early nonlinear stage, filamentary structures develop and extend in the direction of the effective gravity. The blob-like structures appear when the radially extending filaments break off and disconnect from the core plasma. The morphology and the dynamics of these filaments and blobs vary dramatically with a sensitive dependence on the dissipation mechanisms in the system and the initial perturbation. Despite the complexity in morphology and dynamics, the nature of the entire blob formation process in the shear-less slab configuration remains strictly interchange without involving any change in magnetic topology.

  3. Assessment of semen quality in pure and crossbred Jersey bulls

    PubMed Central

    Kumar, Umesh; Gawande, Ajay P.; Sahatpure, Sunil K.; Patil, Manoj S.; Lakde, Chetan K.; Bonde, Sachin W.; Borkar, Pradnyankur L.; Poharkar, Ajay J.; Ramteke, Baldeo R.

    2015-01-01

    Aim: To compare the seminal attributes of neat, pre-freeze (at equilibration), and post-freeze (24 h after freezing) semen in pure and crossbred Jersey bulls. Materials and Methods: Total 36 ejaculates (3 ejaculates from each bull) were collected from 6 pure Jersey and 6 crossbred Jersey bulls and evaluated for various seminal attributes during neat, pre-freeze, and post-freeze semen. Results: The mean (±standard error [SE]) values of neat semen characteristics in pure and crossbred Jersey bulls were recorded such as volume (ml), color, consistency, mass activity (scale: 0-5), and sperm concentration (millions/ml). The extended semen was further investigated at pre-freeze and post-freeze stages and the mean (±SE) values recorded at neat, pre-freeze, and post-freeze semen were compared between pure and crossbred Jersey bulls; sperm motility (80.55±1.70%, 62.77±1.35%, 46.11±1.43% vs. 80.00±1.80%, 65.00±1.66%, 47.22±1.08%), live sperm count (83.63±1.08%, 71.72±1.09%, 58.67±1.02% vs. 80.00±1.08%, 67.91±1.20%, 51.63±0.97%), total abnormal sperm count (8.38±0.32%, 12.30±0.39%, 16.75±0.42% vs. 9.00±0.45%, 12.19±0.48%, 18.11±0.64%), hypo-osmotic swelling (HOS) reacted spermatozoa (71.88±0.77%, 62.05±0.80%, 47.27±1.05% vs. 72.77±1.02%, 62.11±0.89%, 45.94±1.33%), acrosome integrity (89.05±0.83%, 81.33±0.71%, 71.94±0.86% vs. 86.55±0.57%, 78.66±0.42%, 69.38±0.53%), and DNA integrity (99.88±0.07%, 100, 99.66±0.11% vs. 99.94±0.05%, 100, 99.44±0.18%,). The volume, color, consistency, sperm concentration, and initial motility in pure and crossbred Jersey bulls did not differ significantly (p>0.05). The mass activity was significantly (p<0.05) higher in pure Jersey as compare to crossbred Jersey bulls. Live sperm percentage and acrosome integrity was significantly (p<0.01) higher in pure Jersey bulls as compared to crossbred Jersey bulls. However, no statistical difference (p>0.05) was observed in abnormal sperm; HOS reacted spermatozoa and DNA

  4. Structure and properties of rapidly solidified pure tin

    NASA Astrophysics Data System (ADS)

    El-Ashram, T.

    2006-03-01

    A comparison has been made between rapidly solidified (RS) pure Sn using melt-spinning technique and Sn produced by conventional casting, using X-ray diffraction (XRD) analysis, differential thermal analysis (DTA), temperature dependence of resistivity (TDR), density measurement and the dynamical resonance method (DRM) for measuring Young's modulus and internal friction. From the XRD and density measurement, it is found that high concentration of vacancies is present in pure Sn RS, the vacancy concentration is found to be 7x10(-3) . From the DTA measurements, we know that there is an increase in the thermodynamic functions such as enthalpy (Delta H), entropy (Delta S) and free energy (Delta G), and also, there is a decrease in the melting temperature. From the TDR results it follows that the resistivity at room temperature is increased and the temperature coefficient of resistivity is decreased. Finally, DRM results show that Young's modulus is decreased and the internal friction is increased.

  5. Control aspects of quantum computing using pure and mixed states

    PubMed Central

    Schulte-Herbrüggen, Thomas; Marx, Raimund; Fahmy, Amr; Kauffman, Louis; Lomonaco, Samuel; Khaneja, Navin; Glaser, Steffen J.

    2012-01-01

    Steering quantum dynamics such that the target states solve classically hard problems is paramount to quantum simulation and computation. And beyond, quantum control is also essential to pave the way to quantum technologies. Here, important control techniques are reviewed and presented in a unified frame covering quantum computational gate synthesis and spectroscopic state transfer alike. We emphasize that it does not matter whether the quantum states of interest are pure or not. While pure states underly the design of quantum circuits, ensemble mixtures of quantum states can be exploited in a more recent class of algorithms: it is illustrated by characterizing the Jones polynomial in order to distinguish between different (classes of) knots. Further applications include Josephson elements, cavity grids, ion traps and nitrogen vacancy centres in scenarios of closed as well as open quantum systems. PMID:22946034

  6. The value of mortality risk reductions. Pure altruism - a confounder?

    PubMed

    Gyrd-Hansen, Dorte; Kjær, Trine; Seested Nielsen, Jytte

    2016-09-01

    This paper examines public valuations of mortality risk reductions. We set up a theoretical framework that allows for altruistic preferences, and subsequently test theoretical predictions through the design of a discrete choice experiment. By varying the tax scenario (uniform versus individual tax), the experimental design allows us to verify whether pure altruistic preferences are present and the underlying causes. We find evidence of negative pure altruism. Under a coercive uniform tax system respondents lower their willingness to pay possibly to ensure that they are not forcing others to pay at a level that corresponds to their own - higher - valuations. This hypothesis is supported by the observation that respondents perceive other individuals' valuations to be lower than their own. Our results suggest that public valuations of mortality risk reductions may underestimate the true societal value because respondents are considering other individuals' welfare, and wrongfully perceive other people's valuations to be low. PMID:27494571

  7. Formation of "Chemically Pure" Magnetite from Mg-Fe-Carbonates Implications for the Exclusively Inorganic Origin of Magnetite and Sulfides in Martian Meteorite ALH84001

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, Douglas W.; Lauer, H. V., Jr.; Morris, R. V.; Trieman, A. H.; McKay, G. A.

    2006-01-01

    Magnetite and sulfides in the black rims of carbonate globules in Martian meteorite ALH84001 have been studied extensively because of the claim by McKay et al. that they are biogenic in origin. However, exclusively inorganic (abiotic) processes are able to account for the occurrence of carbonate-sulfide-magnetite assemblages in the meteorite. We have previously precipitated chemically zoned and sulfide-bearing carbonate globules analogous to those in ALH84001 (at less than or equal to 150 C) from multiple fluxes of variable-composition Ca-Mg-Fe-CO2-S-H2O solutions. Brief heating of precipitated globules to approx. 470 C produced magnetite and pyrrhotite within the globules by thermal decomposition of siderite and pyrite, respectively. We have also shown that morphology of magnetite formed by inorganic thermal decomposition of Fe-rich carbonate is similar to the morphology of so-called biogenic magnetite in the carbonate globules of ALH84001. Magnetite crystals in the rims of carbonate globules in ALH84001 are chemically pure [Note: "Chemically pure" is defined here as magnetite with Mg at levels comparable or lower than Mg detected by [8] in ALH84001 magnetite]. A debate continues on whether or not chemically pure magnetite can form by the thermal decomposition of mixed Mg-Fe-carbonates that have formed under abiotic conditions. Thomas-Keprta et al. argue that it is not possible to form Mg-free magnetite from Mg-Fe-carbonate based on thermodynamic data. We previously suggested that chemically pure magnetite could form by the thermal decomposition of relatively pure siderite in the outer rims of the globules. Mg-Fe-carbonates may also thermally decompose under conditions conducive for formation of chemically pure magnetite. In this paper we show through laboratory experiments that chemically pure magnetite can form by an inorganic process from mixed Mg-Fe-carbonates.

  8. Carboranylphosphinic Acids: A New Class of Purely Inorganic Ligands.

    PubMed

    Oleshkevich, Elena; Teixidor, Francesc; Choquesillo-Lazarte, Duane; Sillanpää, Reijo; Viñas, Clara

    2016-03-01

    Purely inorganic carboranyl phosphinates were prepared, and the influence of the cluster on the reactivity of the phosphinate group was studied. Electron-withdrawal by the carboranyl carbon atoms, combined with space-filling efficiency and enhanced aromaticity of the cluster cage, renders the phosphorus more difficult to oxidize. This enables carboranyl phosphinates to survive harsh oxidizing conditions, a property which is uncommon in organic phosphinates. PMID:26638876

  9. Pure versus hybrid: performance implications of Porter's generic strategies.

    PubMed

    Kumar, K; Subramanian, R; Yauger, C

    1997-01-01

    This article identifies the strategic types in the hospital industry based on the hospital's use of Porter's generic strategies in their pure and hybrid forms. The article also examines differences in performance of hospitals across strategic types. Results indicate that hospitals that follow a focussed cost leadership strategy, in general, have superior performance on a variety of performance measures, while hospitals that use a combination of cost leadership and differentiation perform the poorest. Implications of findings for hospital administrators are also discussed.

  10. Lateral Stress Measurements in Pure Tungsten during Shock Loading

    SciTech Connect

    Millett, J. C. F.; Gray, G. T. III; Bourne, N. K.

    2006-07-28

    Longitudinal and lateral stresses during the shock loading of pure tungsten have been measured using manganin stress gauges. The Hugoniot has been compared to the previous work of others and shown to be in close agreement. Lateral stresses have been shown to increase behind the shock front, implying that the shear strength decreases. Whilst this is similar to results in tantalum, comparison with recovery experiments in the literature suggests that this may be due in part to a brittle failure process.

  11. Pure Lovelock gravity and Chern-Simons theory

    NASA Astrophysics Data System (ADS)

    Concha, P. K.; Durka, R.; Inostroza, C.; Merino, N.; Rodríguez, E. K.

    2016-07-01

    We explore the possibility of finding pure Lovelock gravity as a particular limit of a Chern-Simons action for a specific expansion of the AdS algebra in odd dimensions. We derive in detail this relation at the level of the action in five and seven dimensions. We provide a general result for higher dimensions and discuss some issues arising from the obtained dynamics.

  12. Nonlocality in pure and mixed n-qubit X states

    NASA Astrophysics Data System (ADS)

    Batle, J.; Ooi, C. H. Raymond; Farouk, Ahmed; Abdalla, S.

    2016-04-01

    Nonlocality for general multiqubit X states is studied in detail. Pure and mixed states are analyzed as far as their maximum amount of nonlocality is concerned, and analytic results are obtained for important families of these states. The particular form of nonzero diagonal and antidiagonal matrix elements makes the corresponding study easy enough to obtain exact results. We also provide a numerical recipe to randomly generate an important family of X states endowed with a given degree of mixture.

  13. Pure subrings of the rings Z{sub {chi}}

    SciTech Connect

    Tsarev, Andrei V

    2009-10-31

    Pure subrings of finite rank in the Z-adic completion of the ring of integers and in its homomorphic images are considered. Certain properties of these rings are studied (existence of an identity element, decomposability into a direct sum of essentially indecomposable ideals, condition for embeddability into a csp-ring, etc.). Additive groups of these rings and conditions under which these rings are subrings of algebraic number fields are described. Bibliography: 12 titles.

  14. Pure closed posteromedial dislocation of the tibiotalar joint without fracture.

    PubMed

    Wang, Yun-tao; Wu, Xiao-tao; Chen, Hui

    2013-08-01

    Pure tibiotalar dislocation without an associated fracture is an extremely rare injury. We present three cases of closed posteromedial tibiotalar dislocation without any associated fractures to the foot, ankle, or leg. All patients were treated conservatively with immediate closed reduction under general or local anaesthesia and immobilised in a short leg cast for six weeks without weight-bearing resulting in a satisfactory outcome at the final follow-up. A review of the literature is also presented in this paper.

  15. Synthesis and optical studies of chemically synthesized PPy/Al2O3 nanocomposites

    NASA Astrophysics Data System (ADS)

    Bahadur, Indra; Mishra, Sheo K.; Tripathi, Akhilesh; Shukla, R. K.

    2016-05-01

    In the present work, we have synthesised pure and 2wt% Al2O3 doped PPy by the chemical oxidation method. XRD patterns of 2wt% Al2O3 doped PPy shows several broad peaks while pure PPy shows only one single peak indicating poor crystalline phase of PPy. FTIR spectra confirm the formation of PPy and also suggest that doping of Al2O3 in PPy does not affect its structure. PL shows several emission peaks for both samples located at ˜365 nm with two shoulders at ˜473 nm and ˜533 nm. The further synthesis and properties study is under investigation.

  16. Idealization in Chemistry: Pure Substance and Laboratory Product

    NASA Astrophysics Data System (ADS)

    Fernández-González, Manuel

    2013-07-01

    This article analyzes the concept of idealization in chemistry and the role played by pure substance and laboratory product. This topic has evident repercussions in the educational contexts that are applied to the science classroom, which are highlighted throughout the text. A common structure for knowledge construction is proposed for both physics and chemistry with particular emphasis on the relations between two of the levels: the ideal level and the quasi-ideal level. The ideal level is crucial for operations related to theoretical constructions and explanations, whereas the quasi-ideal level is of special importance in the verification of propositions. In chemistry, the ideal level and the quasi-ideal level include the entities, pure substance and laboratory product, respectively. This article provides an in-depth discussion of the concept of pure substance, an idealized entity whose empirical correlate is laboratory product. The study of the link between the two is a very significant part of the problem of the relations between theory and reality in chemistry. These entities are used to analyze and interpret different situations and contexts in research as well as teaching. The article concludes by using classroom examples to illustrate the didactic implications of the issues addressed.

  17. Ligands Slow Down Pure-Dephasing in Semiconductor Quantum Dots.

    PubMed

    Liu, Jin; Kilina, Svetlana V; Tretiak, Sergei; Prezhdo, Oleg V

    2015-09-22

    It is well-known experimentally and theoretically that surface ligands provide additional pathways for energy relaxation in colloidal semiconductor quantum dots (QDs). They increase the rate of inelastic charge-phonon scattering and provide trap sites for the charges. We show that, surprisingly, ligands have the opposite effect on elastic electron-phonon scattering. Our simulations demonstrate that elastic scattering slows down in CdSe QDs passivated with ligands compared to that in bare QDs. As a result, the pure-dephasing time is increased, and the homogeneous luminescence line width is decreased in the presence of ligands. The lifetime of quantum superpositions of single and multiple excitons increases as well, providing favorable conditions for multiple excitons generation (MEG). Ligands reduce the pure-dephasing rates by decreasing phonon-induced fluctuations of the electronic energy levels. Surface atoms are most mobile in QDs, and therefore, they contribute greatly to the electronic energy fluctuations. The mobility is reduced by interaction with ligands. A simple analytical model suggests that the differences between the bare and passivated QDs persist for up to 5 nm diameters. Both low-frequency acoustic and high-frequency optical phonons participate in the dephasing processes in bare QDs, while low-frequency acoustic modes dominate in passivated QDs. The theoretical predictions regarding the pure-dephasing time, luminescence line width, and MEG can be verified experimentally by studying QDs with different surface passivation. PMID:26284384

  18. Metastable growth of pure wurtzite InGaAs microstructures.

    PubMed

    Ng, Kar Wei; Ko, Wai Son; Lu, Fanglu; Chang-Hasnain, Connie J

    2014-08-13

    III-V compound semiconductors can exist in two major crystal phases, namely, zincblende (ZB) and wurtzite (WZ). While ZB is thermodynamically favorable in conventional III-V epitaxy, the pure WZ phase can be stable in nanowires with diameters smaller than certain critical values. However, thin nanowires are more vulnerable to surface recombination, and this can ultimately limit their performances as practical devices. In this work, we study a metastable growth mechanism that can yield purely WZ-phased InGaAs microstructures on silicon. InGaAs nucleates as sharp nanoneedles and expand along both axial and radial directions simultaneously in a core-shell fashion. While the base can scale from tens of nanometers to over a micron, the tip can remain sharp over the entire growth. The sharpness maintains a high local surface-to-volume ratio, favoring hexagonal lattice to grow axially. These unique features lead to the formation of microsized pure WZ InGaAs structures on silicon. To verify that the WZ microstructures are truly metastable, we demonstrate, for the first time, the in situ transformation from WZ to the energy-favorable ZB phase inside a transmission electron microscope. This unconventional core-shell growth mechanism can potentially be applied to other III-V materials systems, enabling the effective utilization of the extraordinary properties of the metastable wurtzite crystals.

  19. Behavior of pure gallium in water and various saline solutions.

    PubMed

    Horasawa, N; Nakajima, H; Takahashi, S; Okabe, T

    1997-12-01

    This study investigated the chemical stability of pure gallium in water and saline solutions in order to obtain fundamental knowledge about the corrosion mechanism of gallium-based alloys. A pure gallium plate (99.999%) was suspended in 50 mL of deionized water, 0.01%, 0.1% or 1% NaCl solution at 24 +/- 2 degrees C for 1, 7, or 28 days. The amounts of gallium released into the solutions were determined by atomic absorption spectrophotometry. The surfaces of the specimens were examined after immersion by x-ray diffractometry (XRD) and x-ray photoelectron spectroscopy (XPS). In the solutions containing 0.1% or more NaCl, the release of gallium ions into the solution was lowered when compared to deionized water after 28-day immersion. Gallium oxide monohydroxide was found by XRD on the specimens immersed in deionized water after 28-day immersion. XPS indicated the formation of gallium oxide/hydroxide on the specimens immersed in water or 0.01% NaCl solution. The chemical stability of pure solid gallium was strongly affected by the presence of Cl- ions in the aqueous solution.

  20. Feasibility of purely endoscopic intramedullary fixation of mandibular condyle fractures.

    PubMed

    Frake, Paul C; Goodman, Joseph F; Joshi, Arjun S

    2015-01-01

    The investigators of this study hypothesized that fractures of the mandibular condyle can be repaired using short-segment intramedullary implants and purely endoscopic surgical technique, using a basic science, human cadaver model in an academic center. Endoscopic instrumentation was used through a transoral mucosal incision to place intramedullary implants of 2 cm in length into osteotomized mandibular condyles. The surgical maneuvers that required to insert these implants, including condyle positioning, reaming, implant insertion, and seating of the mandibular ramus, are described herein. Primary outcome was considered as successful completion of the procedure. Ten cadaveric mandibular condyles were successfully repaired with rigid intramedullary internal fixation without the use of external incisions. Both insertion of a peg-type implant and screwing a threaded implant into the condylar head were possible. The inferior portion of the implant remained exposed, and the ramus of the mandible was manipulated into position on the implant using retraction at the sigmoid notch. The results of this study suggest that purely endoscopic repair of fractures of the mandibular condyle is possible by using short-segment intramedullary titanium implants and a transoral endoscopic approach without the need for facial incisions or punctures. The biomechanical advantages of these intramedullary implants, including improved strength and resistance to mechanical failure compared with miniplates, have been recently established. The combination of improved implant design and purely endoscopic technique may allow for improved fixation and reduced surgical- and implant-related morbidity in the treatment of condylar fractures. PMID:25534058

  1. CCN activation of pure and coated carbon black particles.

    PubMed

    Dusek, U; Reischl, G P; Hitzenberger, R

    2006-02-15

    The CCN (cloud condensation nucleus) activation of pure and coated carbon black particles was investigated using the University of Vienna cloud condensation nuclei counter (Giebl, H.; Berner, A.; Reischl, G.; Puxbaum, H.; Kasper-Giebl, A.; Hitzenberger, R. J. Aerosol Sci. 2002, 33, 1623-1634). The particles were produced by nebulizing an aqueous suspension of carbon black in a Collison atomizer. The activation of pure carbon black particles was found to require higher supersaturations than predicted by calculations representing the particles as insoluble, wettable spheres with mobility equivalent diameter. To test whether this effect is an artifact due to heating of the light-absorbing carbon black particles in the laser beam, experiments at different laser powers were conducted. No systematic dependence of the activation of pure carbon black particles on laser power was observed. The observations could be modeled using spherical particles and an effective contact angle of 4-6 degrees of water at their surface. The addition of a small amount of NaCl to the carbon black particles (by adding 5% by mass NaCl to the carbon black suspension) greatly enhanced their CCN efficiency. The measured CCN efficiencies were consistent with Kohler theory for particles consisting of insoluble and hygroscopic material. However, coating the carbon black particles with hexadecanol (a typical film-forming compound with one hydrophobic and one hydrophilic end) efficiently suppressed the CCN activation of the carbon black particles.

  2. Path integral regularization of pure Yang-Mills theory

    SciTech Connect

    Jacquot, J. L.

    2009-07-15

    In enlarging the field content of pure Yang-Mills theory to a cutoff dependent matrix valued complex scalar field, we construct a vectorial operator, which is by definition invariant with respect to the gauge transformation of the Yang-Mills field and with respect to a Stueckelberg type gauge transformation of the scalar field. This invariant operator converges to the original Yang-Mills field as the cutoff goes to infinity. With the help of cutoff functions, we construct with this invariant a regularized action for the pure Yang-Mills theory. In order to be able to define both the gauge and scalar fields kinetic terms, other invariant terms are added to the action. Since the scalar fields flat measure is invariant under the Stueckelberg type gauge transformation, we obtain a regularized gauge-invariant path integral for pure Yang-Mills theory that is mathematically well defined. Moreover, the regularized Ward-Takahashi identities describing the dynamics of the gauge fields are exactly the same as the formal Ward-Takahashi identities of the unregularized theory.

  3. Analysis of Ultra-Pure Gases by Ion Mobility Spectrometry

    NASA Technical Reports Server (NTRS)

    Stimac, Robert M.; Wernlund, Roger F.; Cohen, Martin J.

    1995-01-01

    Work has continued with the evaluation of the Ion Mobility Spectrometer (IMS) for the analysis of gases having low parts-per-billion (10(exp -9)) water concentration. A modified PCP, inc. MMS-160 Mobility Mass Spectrometer System was used for the analysis of ultra-pure argon and nitrogen. The MMS-160 system permits the mass-identification of unique reactant and product ions observed in the reduced-water host gases. When the water is removed to low ppb levels, higher energy reactant ions are observed. In nitrogen, distinct odd- and even-numbered nitrogen cluster ion mobility peaks are observed, as well as adduct ion peaks from the trace contaminants in the gas. Argon also produces a cluster ion mobility peak and adduct ion peaks from trace components in the gas. Levels of contaminants in these ultra-pure gases can be determined from the ion mobility spectra. A calibrated source was used to provide variable known quantities of water to the pure gas supply of the IMS.

  4. Al 1s-2p Absorption Spectroscopy of Shock-Wave Heating and Compression in Laser-Driven Planar Foil

    SciTech Connect

    Sawada, H.; Regan, S.P.; Radha, P.B.; Epstein, R.; Li, D.; Goncharov, V.N.; Hu, S.X.; Meyerhofer, D.D.; Delettrez, J.A.; Jaanimagi, P.A.; Smalyuk, V.A.; Boehly, T.R.; Sangster, T.C.; Yaakobi, B.; Mancini, R.C.

    2009-05-19

    Time-resolved Al 1s-2p absorption spectroscopy is used to diagnose direct-drive, shock-wave heating and compression of planar targets having nearly Fermi-degenerate plasma conditions (Te ~ 10–40 eV, rho ~ 3–11 g/cm^3) on the OMEGA Laser System [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. A planar plastic foil with a buried Al tracer layer was irradiated with peak intensities of 10^14–10^15 W/cm^2 and probed with the pseudocontinuum M-band emission from a point-source Sm backlighter in the range of 1.4–1.7 keV. The laser ablation process launches 10–70 Mbar shock waves into the CH/Al/CH target. The Al 1s-2p absorption spectra were analyzed using the atomic physic code PRISMSPECT to infer Te and rho in the Al layer, assuming uniform plasma conditions during shock-wave heating, and to determine when the heat front penetrated the Al layer. The drive foils were simulated with the one-dimensional hydrodynamics code LILAC using a flux-limited (f =0.06 and f =0.1) and nonlocal thermal-transport model [V. N. Goncharov et al., Phys. Plasmas 13, 012702 (2006)]. The predictions of simulated shock-wave heating and the timing of heat-front penetration are compared to the observations. The experimental results for a wide variety of laser-drive conditions and buried depths have shown that the LILAC predictions using f = 0.06 and the nonlocal model accurately model the shock-wave heating and timing of the heat-front penetration while the shock is transiting the target. The observed discrepancy between the measured and simulated shock-wave heating at late times of the drive can be explained by the reduced radiative heating due to lateral heat flow in the corona.

  5. Analysis of petroleum contaminated soils by spectral modeling and pure response profile recovery of n-hexane.

    PubMed

    Chakraborty, Somsubhra; Weindorf, David C; Li, Bin; Ali, Md Nasim; Majumdar, K; Ray, D P

    2014-07-01

    This pilot study compared penalized spline regression (PSR) and random forest (RF) regression using visible and near-infrared diffuse reflectance spectroscopy (VisNIR DRS) derived spectra of 164 petroleum contaminated soils after two different spectral pretreatments [first derivative (FD) and standard normal variate (SNV) followed by detrending] for rapid quantification of soil petroleum contamination. Additionally, a new analytical approach was proposed for the recovery of the pure spectral and concentration profiles of n-hexane present in the unresolved mixture of petroleum contaminated soils using multivariate curve resolution alternating least squares (MCR-ALS). The PSR model using FD spectra (r(2) = 0.87, RMSE = 0.580 log10 mg kg(-1), and residual prediction deviation = 2.78) outperformed all other models tested. Quantitative results obtained by MCR-ALS for n-hexane in presence of interferences (r(2) = 0.65 and RMSE 0.261 log10 mg kg(-1)) were comparable to those obtained using FD (PSR) model. Furthermore, MCR ALS was able to recover pure spectra of n-hexane.

  6. Analysis of petroleum contaminated soils by spectral modeling and pure response profile recovery of n-hexane.

    PubMed

    Chakraborty, Somsubhra; Weindorf, David C; Li, Bin; Ali, Md Nasim; Majumdar, K; Ray, D P

    2014-07-01

    This pilot study compared penalized spline regression (PSR) and random forest (RF) regression using visible and near-infrared diffuse reflectance spectroscopy (VisNIR DRS) derived spectra of 164 petroleum contaminated soils after two different spectral pretreatments [first derivative (FD) and standard normal variate (SNV) followed by detrending] for rapid quantification of soil petroleum contamination. Additionally, a new analytical approach was proposed for the recovery of the pure spectral and concentration profiles of n-hexane present in the unresolved mixture of petroleum contaminated soils using multivariate curve resolution alternating least squares (MCR-ALS). The PSR model using FD spectra (r(2) = 0.87, RMSE = 0.580 log10 mg kg(-1), and residual prediction deviation = 2.78) outperformed all other models tested. Quantitative results obtained by MCR-ALS for n-hexane in presence of interferences (r(2) = 0.65 and RMSE 0.261 log10 mg kg(-1)) were comparable to those obtained using FD (PSR) model. Furthermore, MCR ALS was able to recover pure spectra of n-hexane. PMID:24686115

  7. Pure word deafness. Analysis of a case with bilateral lesions and a defect at the prephonemic level.

    PubMed

    Auerbach, S H; Allard, T; Naeser, M; Alexander, M P; Albert, M L

    1982-06-01

    We have demonstrated that the deficit in speech perception in our patient with pure word deafness is secondary to a prephonemic temporal auditory acuity disorder. We delineated the nature of the auditory processing deficit in our patient with bilateral lesions and then demonstrated the presence of a predicted deficit in phonemic discrimination. This pattern is comparable to previous cases with bilateral lesions and distinct from other cases with unilateral lesions. Review of previous reports suggests that there are two distinct types of pure word deafness: type 1, in which the deficit is prephonemic and related to a temporal auditory acuity disorder, and type 2, a form that is independent of a temporal auditory acuity disorder, and has a deficit in linguistic discrimination that does not adhere to a prephonemic pattern (Denes and Semenza, 1975; Saffran et al., 1976). The former has been associated with bilateral temporal lobe lesions (Naeser, 1974; Chocholle et al., 1975), the latter with left unilateral lesions (Denes and Semenza, 1975; Saffran et al., 1976). The first form is an apperceptive disorder, whereas the second represents a higher disorder in phonemic discrimination and may be considered a fragment of Wernicke's aphasia.

  8. Angels and demons are among us: assessing individual differences in belief in pure evil and belief in pure good.

    PubMed

    Webster, Russell J; Saucier, Donald A

    2013-11-01

    We conducted five studies to demonstrate that individuals' beliefs in pure evil (BPE) and in pure good (BPG) are valid and important psychological constructs. First, these studies together demonstrated that BPE and BPG are reliable, unitary, and stable constructs each composed of eight theoretically interdependent dimensions. Second, these studies showed that across a wide variety of different measures, higher BPE consistently related to greater intergroup aggression (e.g., supporting the death penalty and preemptive military aggression) and less intergroup prosociality (e.g., opposing criminal rehabilitation, proracial policies, and beneficial social programs), while higher BPG consistently related to less intergroup aggression (e.g., opposing proviolent foreign relations and torture) and greater intergroup prosociality (e.g., supporting criminal rehabilitation and support for diplomacy). In sum, these studies evidence that BPE and BPG relate to aggressive and prosocial orientations toward others and have strong potential to advance current theories on prejudice, aggression, and prosociality.

  9. Angels and demons are among us: assessing individual differences in belief in pure evil and belief in pure good.

    PubMed

    Webster, Russell J; Saucier, Donald A

    2013-11-01

    We conducted five studies to demonstrate that individuals' beliefs in pure evil (BPE) and in pure good (BPG) are valid and important psychological constructs. First, these studies together demonstrated that BPE and BPG are reliable, unitary, and stable constructs each composed of eight theoretically interdependent dimensions. Second, these studies showed that across a wide variety of different measures, higher BPE consistently related to greater intergroup aggression (e.g., supporting the death penalty and preemptive military aggression) and less intergroup prosociality (e.g., opposing criminal rehabilitation, proracial policies, and beneficial social programs), while higher BPG consistently related to less intergroup aggression (e.g., opposing proviolent foreign relations and torture) and greater intergroup prosociality (e.g., supporting criminal rehabilitation and support for diplomacy). In sum, these studies evidence that BPE and BPG relate to aggressive and prosocial orientations toward others and have strong potential to advance current theories on prejudice, aggression, and prosociality. PMID:23885037

  10. Strength tests of thin-walled elliptic duralumin cylinders in pure bending and in combined pure bending and torsion

    NASA Technical Reports Server (NTRS)

    Lundquist, Eugene E; Stowell, Elbridge Z

    1942-01-01

    An analysis is presented of the results of tests made by the Massachusetts Institute of Technology and by the National Advisory Committee for Aeronautics on an investigation of the strength of thin-walled circular and elliptic cylinders in pure bending and in combined torsion and bending. In each of the loading conditions, the bending moments were applied in the plane of the major axis of the ellipse.

  11. De-Excitation of High-Rydberg Antihydrogen in a Strongly Magnetized Pure Positron Plasma

    NASA Astrophysics Data System (ADS)

    Bass, E. M.

    2005-10-01

    The rate at which highly excited atoms relax to deeper binding is found with classical theories and simulations. This rate relates to antihydrogen formation experiments where such atoms are formed in pure-positron, Penning trap plasmas.ootnotetextG.Gabrielse, N.S. Bowden, P. Oxley, et al., Phys. Rev. Lett. 89, 213401 (2002); M. Amoretti, C. Amsler, G. Bonomi, et al., Nature (London) 419, 456 (2002). The analysis concerns atoms that have passed the kinetic bottleneck at binding energy ɛ 4kT.ootnotetextM.E. Glinsky and T.M. O'Neil, Phys. Fluids B 3, 1279 (1991). Energy loss caused by collisions between atoms and plasma positrons is calculated in two ways: For close collisions, a molecular dynamics simulation gives the energy loss; for large-impact parameter collisions, theoretical expressions based on Fokker-Planck theory are employed.ootnotetextEric M. Bass and Daniel H.E. Dubin, Phys. Plasmas 11, 1240 (2004). For a finite magnetic field, the energy loss rate scales as 1/ɛ, just as for infinite field,^2 but with a larger coefficient. A statistical description of energy loss by radiation and Stark mixing will also be discussed.

  12. Stability of Pure Hydrous Silica at Geotherm Temperatures up to 70 GPa

    NASA Astrophysics Data System (ADS)

    Nisr, C.; Shim, S. H.; Leinenweber, K. D.; Hervig, R. L.; Prakapenka, V.; Meng, Y.; Liu, Z.

    2015-12-01

    Stishovite, in the rutile structure with octahedrally coordinated silicon, is expected to exist in silica rich parts of subducted oceanic slabs and crustal fragments in the Earth's mantle, and has been considered for a long time to be essentially anhydrous. However, Spektor et al., (2011) have shown that ~1.3 wt% can be incorporated into pure Al-free stishovite at 10 GPa and 723 K. Yet, the stability and physical properties of hydrous silica at mantle related pressures and temperatures are unknown. We have synthesized hydrous silica samples in the multi anvil press at 9-20 GPa and 700-900 K, and in the laser-heated diamond anvil cell at 17-70 GPa and 1400-2100 K. Three different sample setups have been used: dry silica gel in an H2O medium, anhydrous stishovite in an H2O medium, and hydrous silica gel in a Ne or Ar medium. The presence of percent level of water was found by Secondary Ion Mass Spectrometry, and Raman and Infrared spectroscopy measurements. X-ray diffraction patterns show that the unit-cell volumes of the recovered stishovite samples are greater by 0.2-3.9 % compared with anhydrous stishovite at 1 bar. The unit-cell volumes show strong linear correlation with their c/a ratio suggesting that the same OH substitution mechanism persists for a wide range of water content. Based on unit-cell volumes vs water content calibration by Spektor et al., (2011), our samples contain 0.3-7.9 wt% H2O. We found that pure silica is capable of containing as much as 4.9 wt% of H2O at temperatures close to those of the mantle geotherm (e.g., sample synthesized at ~1997 K and ~67 GPa). The highest water contents were found at the highest pressures, suggesting that the pressure stabilizes OH in dense silica. X-ray diffraction patterns have also shown several new diffraction lines upon compression and heating which appear from 45 GPa (1500-2100 K) and are observed up to 100 GPa. The peaks appear to belong to a new hydrous silica phase stable at higher pressures and

  13. Methyl tunnelling in pure and matrix isolated halogenomesitylenes

    NASA Astrophysics Data System (ADS)

    Meinnel, J.; Mani, M.; Nusimovici, M.; Carlile, C. J.; Hennion, B.; Carrié, R.; Wyncke, B.; Sanquer, M.; Tonnard, F.

    1994-10-01

    The trihalogenomesitylenes, C 6(CH 3) 3X 3, where X = Cl, Br, I crystallise in the triclinic P overline1 space- group, such that the three methyl groups in one molecule see different environments. Indeed, we have detected three tunnelling and three torsional transitions in the pure compounds. In the case of a 3.7% mixture of protonated tribromomesitylene in a matrix of hexabromobenzene, we have detected only one tunnelling transition at 102μeV; from this, we conclude that the three methyl groups of the TBM molecule in the dilute mixture are equivalent in what is a relatively symmetrical environment and as a consequence also in the isolated molecule. A solid solution of 6% fully protonated trichloromesitylene in a matrix of fully deuterated TCM gives three transitions similar to those in the pure compound, indicating that there is no strong coupling between the different methyl groups. We also present Raman and FIR spectra of pure TBM giving the phonon frequencies at the Γ point. Some IR absorption maxima fall near maxima of the neutron spectra, indicating coupling between some phonons and the torsional transitions. So as to give us a model of the tribromomesitylene system we have optimised atom-atom Buckingham-type coefficients so as to reproduce the experimental phonon frequencies. The coefficients were used to calculate the intermolecular contribution Vex(θ) to Vs(θ), the potential hindering the methyl groups. The intramolecular contribution Vin(θ) was found using the quantum chemistry program AM1. The total hindering potential Vs(θ) so obtained allowed us to calculate the principal dynamic features of the methyl rotors in reasonable agreement with the experiments.

  14. Super-Maxwellian helium evaporation from pure and salty water

    NASA Astrophysics Data System (ADS)

    Hahn, Christine; Kann, Zachary R.; Faust, Jennifer A.; Skinner, J. L.; Nathanson, Gilbert M.

    2016-01-01

    Helium atoms evaporate from pure water and salty solutions in super-Maxwellian speed distributions, as observed experimentally and modeled theoretically. The experiments are performed by monitoring the velocities of dissolved He atoms that evaporate from microjets of pure water at 252 K and 4-8.5 molal LiCl and LiBr at 232-252 K. The average He atom energies exceed the flux-weighted Maxwell-Boltzmann average of 2RT by 30% for pure water and 70% for 8.5m LiBr. Classical molecular dynamics simulations closely reproduce the observed speed distributions and provide microscopic insight into the forces that eject the He atoms from solution. Comparisons of the density profile and He kinetic energies across the water-vacuum interface indicate that the He atoms are accelerated by He-water collisions within the top 1-2 layers of the liquid. We also find that the average He atom kinetic energy scales with the free energy of solvation of this sparingly soluble gas. This free-energy difference reflects the steeply decreasing potential of mean force on the He atoms in the interfacial region, whose gradient is the repulsive force that tends to expel the atoms. The accompanying sharp decrease in water density suppresses the He-water collisions that would otherwise maintain a Maxwell-Boltzmann distribution, allowing the He atom to escape at high energies. Helium is especially affected by this reduction in collisions because its weak interactions make energy transfer inefficient.

  15. The Dynamics of Spiral Arms in Pure Stellar Disks

    NASA Astrophysics Data System (ADS)

    Fujii, M. S.; Baba, J.; Saitoh, T. R.; Makino, J.; Kokubo, E.; Wada, K.

    2011-04-01

    It has been believed that spiral arms in pure stellar disks, especially the ones spontaneously formed, decay in several galactic rotations due to the increase of stellar velocity dispersions. Therefore, some cooling mechanism, for example dissipational effects of the interstellar medium, was assumed to be necessary to keep the spiral arms. Here, we show that stellar disks can maintain spiral features for several tens of rotations without the help of cooling, using a series of high-resolution three-dimensional N-body simulations of pure stellar disks. We found that if the number of particles is sufficiently large, e.g., 3 × 106, multi-arm spirals developed in an isolated disk can survive for more than 10 Gyr. We confirmed that there is a self-regulating mechanism that maintains the amplitude of the spiral arms. Spiral arms increase Toomre's Q of the disk, and the heating rate correlates with the squared amplitude of the spirals. Since the amplitude itself is limited by Q, this makes the dynamical heating less effective in the later phase of evolution. A simple analytical argument suggests that the heating is caused by gravitational scattering of stars by spiral arms and that the self-regulating mechanism in pure stellar disks can effectively maintain spiral arms on a cosmological timescale. In the case of a smaller number of particles, e.g., 3 × 105, spiral arms grow faster in the beginning of the simulation (while Q is small) and they cause a rapid increase of Q. As a result, the spiral arms become faint in several Gyr.

  16. Probabilistically Perfect Cloning of Two Pure States: Geometric Approach

    NASA Astrophysics Data System (ADS)

    Yerokhin, V.; Shehu, A.; Feldman, E.; Bagan, E.; Bergou, J. A.

    2016-05-01

    We solve the long-standing problem of making n perfect clones from m copies of one of two known pure states with minimum failure probability in the general case where the known states have arbitrary a priori probabilities. The solution emerges from a geometric formulation of the problem. This formulation reveals that cloning converges to state discrimination followed by state preparation as the number of clones goes to infinity. The convergence exhibits a phenomenon analogous to a second-order symmetry-breaking phase transition.

  17. Generation of Pure Bulk Valley Current in Graphene

    NASA Astrophysics Data System (ADS)

    Jiang, Yongjin; Low, Tony; Chang, Kai; Katsnelson, Mikhail I.; Guinea, Francisco

    2013-01-01

    The generation of valley current is a fundamental goal in graphene valleytronics but no practical ways of its realization are known yet. We propose a workable scheme for the generation of bulk valley current in a graphene mechanical resonator through adiabatic cyclic deformations of the strains and a chemical potential in the suspended region. The accompanied strain gauge fields can break the spatial mirror symmetry of the problem within each of the two inequivalent valleys, leading to a finite valley current due to quantum pumping. An all-electrical measurement configuration is designed to detect the novel state with pure bulk valley currents.

  18. Cooperative pulses for pseudo-pure state preparation

    NASA Astrophysics Data System (ADS)

    Wei, Daxiu; Chang, Yan; Glaser, Steffen J.; Yang, Xiaodong

    2014-06-01

    Using an extended version of the optimal-control-based gradient ascent pulse engineering algorithm, cooperative (COOP) pulses are designed for multi-scan experiments to prepare pseudo-pure states in quantum computation. COOP pulses can cancel undesired signal contributions, complementing and generalizing phase cycles. They also provide more flexibility and, in particular, eliminate the need to select specific individual target states and achieve the fidelity of theoretical limit by flexibly choosing appropriate number of scans and duration of pulses. The COOP approach is experimentally demonstrated for three-qubit and four-qubit systems.

  19. Superconductor—Insulator Transitions in Pure Polycrystalline Nb Thin Films

    NASA Astrophysics Data System (ADS)

    Couedo, F.; Crauste, O.; Bergé, L.; Dolgorouky, Y.; Marrache-Kikuchi, C.; Dumoulin, L.

    2012-12-01

    We report on a study of the transport properties of Nb thin films. By varying the thickness of the films from 263 Å to 25 Å, we observed a depression of the superconductivity. Magnetic field was also applied up to 6 T, inducing the disappearance of the superconductivity and the onset of an insulating behavior. The results were compared to those we have already obtained on a highly disordered system, a-NbxSi1-x, to understand whether the same mechanisms for the disappearance of the superconductivity could be at play in pure metallic thin films and in highly disordered systems.

  20. Multiboson Correlation Interferometry with Arbitrary Single-Photon Pure States.

    PubMed

    Tamma, Vincenzo; Laibacher, Simon

    2015-06-19

    We provide a compact full description of multiboson correlation measurements of arbitrary order N in passive linear interferometers with arbitrary input single-photon pure states. This allows us to physically analyze the novel problem of multiboson correlation sampling at the output of random linear interferometers. Our results also describe general multiboson correlation landscapes for an arbitrary number of input single photons and arbitrary interferometers. In particular, we use two different schemes to demonstrate, respectively, arbitrary-order quantum beat interference and 100% visibility entanglement correlations even for input photons distinguishable in their frequencies. PMID:26196976

  1. MONOPOLES AND DYONS IN THE PURE EINSTEIN YANG MILLS THEORY

    SciTech Connect

    HOSOTANI,Y.; BJORAKER,J.

    1999-08-16

    In the pure Einstein-Yang-Mills theory in four dimensions there exist monopole and dyon solutions. The spectrum of the solutions is discrete in asymptotically flat or de Sitter space, whereas it is continuous in asymptotically anti-de Sitter space. The solutions are regular everywhere and specified with their mass, and non-Abelian electric and magnetic charges. In asymptotically anti-de Sitter space a class of monopole solutions have no node in non-Abelian magnetic fields, and are stable against spherically symmetric perturbations.

  2. Emergence of canonical ensembles from pure quantum states.

    PubMed

    Cho, Jaeyoon; Kim, M S

    2010-04-30

    We consider a system weakly interacting with a bath as a thermodynamic setting to establish a quantum foundation of statistical physics. It is shown that even if the composite system is initially in an arbitrary nonequilibrium pure quantum state, the unitary dynamics of a generic weak interaction almost always drives the subsystem into the canonical ensemble, in the usual sense of typicality. A crucial step is taken by assuming that the matrix elements of the interaction Hamiltonian have random phases, while their amplitudes are left unrestricted. PMID:20482093

  3. Cooperative pulses for pseudo-pure state preparation

    SciTech Connect

    Wei, Daxiu; Chang, Yan; Yang, Xiaodong E-mail: xiaodong.yang@sibet.ac.cn; Glaser, Steffen J. E-mail: xiaodong.yang@sibet.ac.cn

    2014-06-16

    Using an extended version of the optimal-control-based gradient ascent pulse engineering algorithm, cooperative (COOP) pulses are designed for multi-scan experiments to prepare pseudo-pure states in quantum computation. COOP pulses can cancel undesired signal contributions, complementing and generalizing phase cycles. They also provide more flexibility and, in particular, eliminate the need to select specific individual target states and achieve the fidelity of theoretical limit by flexibly choosing appropriate number of scans and duration of pulses. The COOP approach is experimentally demonstrated for three-qubit and four-qubit systems.

  4. Infinite tension limit of the pure spinor superstring

    NASA Astrophysics Data System (ADS)

    Berkovits, Nathan

    2014-03-01

    Mason and Skinner recently constructed a chiral infinite tension limit of the Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan formulae for tree-level d = 10 Yang-Mills amplitudes and the NS-NS sector of tree-level d = 10 supergravity amplitudes. In this letter, their chiral infinite tension limit is generalized to the pure spinor superstring which computes a d = 10 superspace version of the Cachazo-He-Yuan formulae for tree-level d = 10 super-Yang-Mills and supergravity amplitudes.

  5. Robust calibration method for pure rotational Raman lidar temperature measurement.

    PubMed

    Chen, Hao; Chen, Siying; Zhang, Yinchao; Guo, Pan; Chen, He; Chen, Binglong

    2015-08-10

    A new calibration method for pure rotational Raman lidar temperature measurement is described in this work. The method forms a temperature-dependent term in the intensity ratio, which is calculable with the radiosonde data, and then derives a calibration factor, with which the temperature is retrievable from the lidar return. The method is demonstrated and compared with existing methods through simulations and experiments. Results of the comparison show that the proposed method could provide more accurate calibrations under low signal-to-noise ratio conditions and could thus reduce the lidar performance requirement for temperature retrieval.

  6. Laboratory astrophysics and molecular astronomy of pure carbon molecules.

    PubMed

    Bernath, P F

    1995-03-01

    The pure carbon molecules Cn are currently of great experimental and theoretical interest. Our work in this area begins with detection of the SiC molecule, which is isovalent with C2. New infrared electronic transitions of C2 and C3 were discovered by emission spectroscopy of hydrocarbon dicharges. The C3 and C5 molecules were found by infrared vibration-rotation spectroscopy of the prototypical obscured carbon star, IRC+10216. C7 and C9 were searched for in the same source, but not found. The laboratory infrared emission spectrum of C60 was recorded to aid in a search for C60 in extraterrestrial sources.

  7. Purely lossy and robust quantum interfaces between light and matter.

    PubMed

    Filip, Radim; Klapka, Petr

    2014-12-15

    The commonly used teleportation-based interfaces between light and matter are very sensitive to noise of matter systems and also to the optical in-coupling and out-coupling losses. These imperfections produce classical noise in the teleportation interface, which significantly limits the transmission of quantum states. We propose robust quantum interfaces between weakly coupled continuous variables of light and matter. The state transfer introduces only pure loss, without any additional classical noise, despite a presence of in-coupling and out-coupling optical losses. These interfaces qualitatively overcome commonly used interfaces based on quantum teleportation. PMID:25607017

  8. Monoclonal gammopathy-associated pure red cell aplasia.

    PubMed

    Korde, Neha; Zhang, Yong; Loeliger, Kelsey; Poon, Andrea; Simakova, Olga; Zingone, Adriana; Costello, Rene; Childs, Richard; Noel, Pierre; Silver, Samuel; Kwok, Mary; Mo, Clifton; Young, Neal; Landgren, Ola; Sloand, Elaine; Maric, Irina

    2016-06-01

    Pure red cell aplasia (PRCA) is a rare disorder characterized by inhibition of erythroid precursors in the bone marrow and normochromic, normocytic anaemia with reticulocytopenia. Among 51 PRCA patients, we identified 12 (24%) patients having monoclonal gammopathy, monoclonal gammopathy of undetermined significance or smouldering multiple myeloma, with presence of monoclonal protein or abnormal serum free light chains and atypical bone marrow features of clonal plasmacytosis, hypercellularity and fibrosis. Thus far, three patients treated with anti-myeloma based therapeutics have responded with reticulocyte recovery and clinical transfusion independence, suggesting plasma cells play a key role in the pathogenesis of this specific monoclonal gammopathy-associated PRCA. PMID:26999424

  9. The KTeV Pure CsI Calorimeter

    SciTech Connect

    Ray, R.E.

    1994-12-01

    KTeV is currently building a state-of-the-art pure CsI electromagnetic calorimeter with a sophisticated digital readout. The CsI array is expected to have better than 1% resolution over a dynamic range of 2--64 GeV. The design of the CsI array is driven by the difficult physics goal of attempting to measure the CP violation parameter Re({epsilon}{prime}/{epsilon}) to 1 part in 10000 in a high-rate neutral beam environment. The physics requirements and their impact on the final design will be discussed.

  10. Thermal stability and strength of deformation microstructures in pure copper

    SciTech Connect

    Saldana, C.; King, Alex H.; Chandrasekar, S.

    2012-05-18

    The plastic flow field produced by machining is utilized to access a range of deformation parameters in pure copper: strains of 1–7, strain rates of 1–1000 s−1 and temperatures as low as 77 K. The strength and stability of the severe plastic deformation microstructures including cellular, elongated, equiaxed and twinned types are characterized. Unique combinations of strengthening and stability are identified in the case of heavily twinned microstructures. These observations offer insights for improving the stability of both single-phase and multicomponent ultrafine-grained alloys.

  11. Purely lossy and robust quantum interfaces between light and matter.

    PubMed

    Filip, Radim; Klapka, Petr

    2014-12-15

    The commonly used teleportation-based interfaces between light and matter are very sensitive to noise of matter systems and also to the optical in-coupling and out-coupling losses. These imperfections produce classical noise in the teleportation interface, which significantly limits the transmission of quantum states. We propose robust quantum interfaces between weakly coupled continuous variables of light and matter. The state transfer introduces only pure loss, without any additional classical noise, despite a presence of in-coupling and out-coupling optical losses. These interfaces qualitatively overcome commonly used interfaces based on quantum teleportation.

  12. Entanglement dynamics of spin systems in pure states

    NASA Astrophysics Data System (ADS)

    Furman, G. B.; Meerovich, V. M.; Sokolovsky, V. L.

    2009-09-01

    We investigate numerically the appearance and evolution of entanglement in spin systems prepared initially in a pure state. We consider the dipolar coupling spin systems of different molecular structures: benzene C6H6 , cyclopentane C5H10 , sodium butyrate CH3(CH2)2CO2Na , and calcium hydroxyapatite Ca5(OH)(PO4)3 . Numerical simulations show that the close relationship exists between the intensity of second order (2Q) coherences and concurrences of nearest spins in a cyclopentane molecule.

  13. Dendritic crystal growth in pure /sup 4/He

    SciTech Connect

    Franck, J.P.; Jung, J.

    1986-08-01

    Dendritic crystal growth of pure hcp and fcc /sup 4/He was observed at pressures between 210 and 6500 bar. Dendrite morphology depends on fluid supercooling and crystal phase. At large supercooling, dendrites with side arms are observed, whereas at low supercooling dendrites grow without side arms. The morpholpogy of hcp /sup 4/He dendrites is strongly influenced by crystalline anisotropy. Comparison with present theories of dendrite growth show good agreement with the power law dependencies of velocity, tip radius, and Peclet number on supercooling. Numerically, theory predicts much larger velocities than are observed. The stability parameter sigma is found to be much smaller than theoretically predicted.

  14. Damage Analysis of Rectangular Section Composite Beam under Pure Bending

    NASA Astrophysics Data System (ADS)

    Liu, Yiping; Xiao, Fan; Liu, Zejia; Tang, Liqun; Fang, Daining

    2013-02-01

    Laminated composite beams are commonly used in engineering applications involving macro to nano structures. Based on the assumption that plain sections remain plain after deformation, this paper analyzes stress distributions in cross-ply laminated composite beams with rectangular cross-sections, and formulates the basic damage equations through Kachanov's damage definition and Janson's failure criterion. The location of the neutral axis and the ultimate bending moment are obtained for pure bending cases. The effect of the elastic modulus of the two layers on the damage evolution is analyzed; a reasonable damage composite beam model is proposed to predict the ultimate bending moment.

  15. Pure versus hybrid: performance implications of Porter's generic strategies.

    PubMed

    Kumar, K; Subramanian, R; Yauger, C

    1997-01-01

    This article identifies the strategic types in the hospital industry based on the hospital's use of Porter's generic strategies in their pure and hybrid forms. The article also examines differences in performance of hospitals across strategic types. Results indicate that hospitals that follow a focussed cost leadership strategy, in general, have superior performance on a variety of performance measures, while hospitals that use a combination of cost leadership and differentiation perform the poorest. Implications of findings for hospital administrators are also discussed. PMID:9358260

  16. Entanglement-fluctuation relation for bipartite pure states

    NASA Astrophysics Data System (ADS)

    Villaruel, Aura Mae B.; Paraan, Francis N. C.

    2016-08-01

    We identify subsystem fluctuations (variances) that measure entanglement in an arbitrary bipartite pure state. These fluctuations are of observables that generalize the notion of polarization to an arbitrary N -level subsystem. We express this polarization fluctuation in terms of subsystem purity and other entanglement measures. The derived entanglement-fluctuation relation is evaluated for the ground states of a one-dimensional free-fermion gas and the Affleck-Kennedy-Lieb-Tasaki spin chain. Our results provide a framework for experimentally measuring entanglement using Stern-Gerlach-type state selectors.

  17. Purely hydrodynamic origin for swarming of swimming particles

    NASA Astrophysics Data System (ADS)

    Oyama, Norihiro; Molina, John Jairo; Yamamoto, Ryoichi

    2016-04-01

    Three-dimensional simulations with fully resolved hydrodynamics are performed to study the collective motion of model swimmers in bulk and confinement. Calculating the dynamic structure factor, we clarified that the swarming in bulk systems can be understood as a pseudoacoustic mode. Under confinement between flat parallel walls, this pseudoacoustic mode leads to a traveling wavelike motion. This swarming behavior is due purely to the hydrodynamic interactions between the swimmers and depends strongly on the type and strength of swimming (i.e., pusher or puller).

  18. Atomistic simulations of (001) symmetric tilt boundaries in Ni/sub 3/Al

    SciTech Connect

    Chen, S.P.; Voter, A.F.; Srolovitz, D.J.

    1986-01-01

    We report a systematic atomistic simulation study of (001) symmetric tilt grain boundaries (GB) in Ni/sub 3/Al, Ni, and Al. We found that the grain boundary energies and cohesive energies of Ni/sub 3/Al and pure fcc Ni are approximately the same. Grain boundary energies and cohesive energies in Ni/sub 3/Al depends strongly on the grain boundary composition. The Al-rich boundaries have highest grain boundary energies and lowest cohesive energies. This offers an explanation for the stoichiometric effect on the boron ductilization.

  19. Interdiffusion and Intrinsic Diffusion in the Mg-Al System

    SciTech Connect

    Brennan, Sarah; Bermudez, Katrina; Sohn, Yong Ho; Kulkarni, Nagraj S

    2012-01-01

    Solid-to-solid diffusion couples were assembled and annealed to examine the diffusion between pure Mg (99.96%) and Al (99.999%). Diffusion anneals were carried out at 300 , 350 , and 400 C for 720, 360, and 240 hours, respectively. Optical and scanning electron microscopes were utilized to identify the formation of the intermetallic phases, -Al12Mg17 and -Al3Mg2 and absence of the -phase in the diffusion couples. Thicknesses of the -Al12Mg17 and -Al3Mg2 phases were measured and the parabolic growth constants were calculated to determine the activation energies for the growth, 165 and 86 KJ/mole, respectively. Concentration profiles were determined with electron microprobe analysis using pure elemental standards. Composition-dependent interdiffusion coefficients in Mg-solid solution, -Al12Mg17 and - Al3Mg2 and Al-solid solutions were calculated based on the Boltzmann-Matano analysis. Average effective interdiffusion coefficients for each phase were also calculated, and the magnitude was the highest for the -Al3Mg2 phase, followed by -Al12Mg17, Al-solid solution and Mg-solid solution. Intrinsic diffusion coefficients based on Huemann s analysis (e.g., marker plane) were determined for the ~38 at.% Mg in the -Al3Mg2 phase. Activation energies and the pre-exponential factors for the inter- and intrinsic diffusion coefficients were calculated for the temperature range examined. The -Al3Mg2 phase was found to have the lowest activation energies for growth and interdiffusion among all four phases studied. At the marker location in the -Al3Mg2 phase, the intrinsic diffusion of Al was found to be faster than that of Mg. Extrapolations of the impurity diffusion coefficients in the terminal solid solutions were made and compared to the available self- and impurity diffusion data from literature. Thermodynamic factor, tracer diffusion coefficients and atomic mobilities at the marker plane composition were approximated using available literature values of Mg activity in the -Al

  20. Reply to comment on 'Tunable three-dimensional intensity distribution by a pure phase-shifting apodizer'

    NASA Astrophysics Data System (ADS)

    Gao, Xiumin

    2007-01-01

    I thank Canales et al. very much for their attention to the effect of the phase apodizer, especially for their comment on my paper [Appl. Opt. 44, 4870 (2005)]. I reinvestigated the three-dimensional intensity distribution by a pure phase-shifting apodizer, and the main results on focal shift, focal split, and three intensity distributions are correct. However, the changing principle of the Strehl ratio is wrong, as Canales et al. show in their comment. Here, I show the cause leading to the erroneous result and give the correct dependence of the Strehl ratio on the inner radius and relative waist width. I am very sorry for the incorrect results in the paper.

  1. Crystal Structure of Pure and Aluminous Calcium Silicate Perovskites at Mantle Related Pressure and Temperature

    NASA Astrophysics Data System (ADS)

    Chen, H.; Shim, S. H.; Leinenweber, K. D.; Meng, Y.; Prakapenka, V.

    2015-12-01

    CaSiO3-perovskite (CaPv) is believed to be the third most abundant mineral (5 wt%) in the Earth's lower mantle (LM). Subducted slabs contain 23 wt% CaPv at the LM related pressure (P) and temperature (T), where Al2O3 could be incorporated into the crystal structure of CaPv (AlCaPv). However, there remains important discrepancy between computations and experiments on the crystal structure of CaPv at high P and low T. Some computations have predicted a tetragonal I4/mcm structure with a pseudo-cubic axial ratio (cp/ap) greater than 1, while X-ray diffraction (XRD) studies have suggested a tetragonal P4/mmm structure with cp/ap ~ 0.995. Using Ne as a pressure medium, we conducted in-situ XRD of CaSiO3 and 5 wt% Al-bearing CaSiO3 in the laser heated diamond anvil cell at the GSECARS and HPCAT sectors of the Advanced Photon Source. Rietveld refinements are performed on the diffraction patterns of CaPv at 300 K and 20-60 GPa. Similar to previous studies, we observed splitting of the 200 and 211 peaks after T-quench in pure CaPv. However, unlike previous experiments, diffraction patterns were more consistent with a tetragonal I4/mcm structure with cp/ap ~ 1.005 than P4/mmm. All the previous diffraction patterns have been measured with an Ar or MgO medium, or even without a medium, while we used more hydrostatic Ne medium. Considering the small free energy differences among different perovskite structures, the crystal structure of CaPv may be very sensitive to non-hydrostatic stresses. In runs with AlCaPv, asymmetrical 200 peaks are found up to 60 GPa and 2200 K, showing that non-cubic could be still stable at mantle geotherm temperatures in AlCaPv. The extreme sensitivity of CaPv on deviatoric stresses may have important implications for the elastic properties of the mantle regions with strong deformations, because the elastic anisotropy can change with the crystal structure of CaPv.

  2. Bounds on probability of transformations between multipartite pure states

    SciTech Connect

    Cui Wei; Helwig, Wolfram; Lo, Hoi-Kwong

    2010-01-15

    For a tripartite pure state of three qubits, it is well known that there are two inequivalent classes of genuine tripartite entanglement, namely the Greenberger-Horne-Zeilinger (GHZ) class and the W class. Any two states within the same class can be transformed into each other with stochastic local operations and classical communication with a nonzero probability. The optimal conversion probability, however, is only known for special cases. Here, lower and upper bounds are derived for the optimal probability of transformation from a GHZ state to other states of the GHZ class. A key idea in the derivation of the upper bounds is to consider the action of the local operations and classical communications (LOCC) protocol on a different input state, namely 1/sq root(2)[|000>-|111>], and to demand that the probability of an outcome remains bounded by 1. We also find an upper bound for more general cases by using the constraints of the so-called interference term and 3-tangle. Moreover, some of the results are generalized to the case in which each party holds a higher dimensional system. In particular, the GHZ state generalized to three qutrits; that is, |GHZ{sub 3}>=1/sq root(3)[|000>+|111>+|222>] shared among three parties can be transformed to any tripartite three-qubit pure state with probability 1 via LOCC. Some of our results can also be generalized to the case of a multipartite state shared by more than three parties.

  3. Pure menstrual migraine with sensory aura: a case report.

    PubMed

    Chen, Jiann-Jy; Hsu, Yung-Chu; Chen, Dem-Lion

    2012-07-01

    Hormonal changes related to the menstrual cycle have a great impact on migraines in women. Menstrual migraine attacks are almost invariably without aura. Categorizing migraines into menstrual or non-menstrual types is one way to stratify migraines without aura according to the appendix criteria of the International Classification of Headache Disorders. We report a peri-menopausal woman whose sensory aura exclusively heralded menstrual migraine. A 51-year-old woman had suffered from monthly episodic headaches since the age of 46. Before a headache, and within 1 h on the first day of her menstruation, she always experienced numbness in her entire left upper limb. After the sensory aura, migrainous headaches occurred with nausea and photophobia. In the postmenopausal period, she no longer had sensory aura, and her headache pattern changed and became less severe. Her physical and neurologic exams as well as electroencephalography, brain magnetic resonance imaging, and conventional angiography were all normal. She fulfilled the diagnosis of pure menstrual migraine with typical sensory aura. To our knowledge, this is the first formal case report of pure menstrual migraine with aura.

  4. Visual command hallucinations in a patient with pure alexia

    PubMed Central

    ffytche, D; Lappin, J; Philpot, M

    2004-01-01

    Around 25% of patients with visual hallucinations secondary to eye disease report hallucinations of text. The hallucinated text conveys little if any meaning, typically consisting of individual letters, words, or nonsense letter strings (orthographic hallucinations). A patient is described with textual visual hallucinations of a very different linguistic content following bilateral occipito-temporal infarcts. The hallucinations consisted of grammatically correct, meaningful written sentences or phrases, often in the second person and with a threatening and command-like nature (syntacto-semantic visual hallucinations). A detailed phenomenological interview and visual psychophysical testing were undertaken. The patient showed a classical ventral occipito-temporal syndrome with achromatopsia, prosopagnosia, and associative visual agnosia. Of particular significance was the presence of pure alexia. Illusions of colour induced by monochromatic gratings and a novel motion–direction illusion were also observed, both consistent with the residual capacities of the patient's spared visual cortex. The content of orthographic visual hallucinations matches the known specialisations of an area in the left posterior fusiform gyrus—the visual word form area (VWFA)—suggesting the two are related. The VWFA is unlikely to be responsible for the syntacto-semantic hallucinations described here as the patient had a pure alexic syndrome, a known consequence of VWFA lesions. Syntacto-semantic visual hallucinations may represent a separate category of textual hallucinations related to the cortical network implicated in the auditory hallucinations of schizophrenia. PMID:14707313

  5. Laser ignition of bulk 1018 carbon steel in pure oxygen

    NASA Technical Reports Server (NTRS)

    Nguyen, K.; Branch, M. C.

    1986-01-01

    Experiments were undertaken to study the ignition characteristics of bulk 1018 carbon steel in a pure oxygen environment. Cylindrical 1018 carbon steel specimens 5 mm in diameter and 5 mm high were ignited by a focused CW CO2 laser beam in a cool, static, pure oxygen environment at oxygen pressures ranging from 0.103 to 6.895 MPa. A two-color pyrometer was designed and used to measure the ignition temperatures of the specimens. The temperature history of a spot approximately 0.5 mm in diameter located at the center of the specimen top surface was recorded with a maximum time resolution of 25 microsec, and with an accuracy of a few percent. Ignition temperature of bulk 1018 carbon steel was identified from the temperature history curve with the aid of the light intensity curve. Results show that 1018 carbon steel specimens ignite at temperatures between 1388 and 1450 K, which are below the melting range of the alloy (1662-1685 K). The ignition temperature of 1018 carbon steel is mildly dependent on oxygen pressure over the range of oxygen pressure investigated in this study.

  6. Thallium Transfer from Hydrochloric Acid Media into Pure Ionic Liquids.

    PubMed

    Tereshatov, Evgeny E; Boltoeva, Maria Yu; Mazan, Valerie; Volia, Merinda F; Folden, Charles M

    2016-03-10

    Pure hydrophobic ionic liquids are known to extract metallic species from aqueous solutions. In this work we have systematically investigated thallium (Tl) extraction from aqueous hydrochloric acid (HCl) solutions into six pure fluorinated ionic liquids, namely imidazolium- and pyrrolidinium-based ionic liquids with bis(trifluoromethanesulfonyl)imide and bis(fluorosulfonyl)-imide anions. The dependence of the Tl extraction efficiency on the structure and composition of the ionic liquid ions, metal oxidation state, and initial metal and aqueous acid concentrations have been studied. Tl concentrations were on the order of picomolar (analyzed using radioactive tracers) and millimolar (analyzed using inductively coupled plasma mass spectrometry). The extraction of the cationic thallium species Tl(+) is higher for ionic liquids with more hydrophilic cations, while for the TlX(z)(3-z) anionic species (where X = Cl(-) and/or Br(-)), the extraction efficiency is greater for ionic liquids with more hydrophobic cations. The highest distribution value of Tl(III) was approximately 2000. An improved mathematical model based on ion exchange and ion pair formation mechanisms has been developed to describe the coextraction of two different anionic species, and the relative contributions of each mechanism have been determined. PMID:26769597

  7. A pure hydrodynamic origin of accretion disk turbulence

    NASA Astrophysics Data System (ADS)

    Nath, Sujit Kumar; Mukhopadhyay, Banibrata

    2016-07-01

    Accretion disks consist of flows for which angular velocity decreases but specific angular momentum increases with increasing radial coordinate. Such flows are Rayleigh stable, but must be turbulent in order to explain observed data. Since molecular viscosity is negligible in these systems, scientists have argued for turbulent viscosity for energy dissipation and hence to explain infall of matter. However, so far, the success to explain the origin of turbulence in accretion disks is done with caveats. Here we investigate the evolution of pure hydrodynamic perturbations in stochastically driven accretion disks. We show that the accretion flows, which are inevitably driven by stochastic noise, are hydrodynamically unstable under linear perturbations. We also argue that in accretion disks, stochastic forcing appears generically due to the presence of shear between different annuli of the disk. This work resolves the turbulence problem of accretion disks from pure hydrodynamics and explains the infall of matter for both hot and cold disks. This would help in explaining the origin of timing and spectral features in the disk flows generically.

  8. Effect of Surface Nanocrystallization on Fatigue Behavior of Pure Titanium

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Sun, Qiaoyan; Xiao, Lin; Sun, Jun

    2016-01-01

    The high-cycle fatigue behavior was investigated in pure titanium after surface nanocrystallization (SNC Ti). Compared with the coarse-grained titanium (CG Ti) samples, the SNC Ti samples exhibit an improved fatigue life. The SNC has a remarkable influence on the fatigue cracks initiation and growth of pure titanium. The results show that, because the free-surface cracking is suppressed by the surface nanogradient structure in the SNC Ti, the fatigue cracks initiation sites change from the free surface to the subsurface. Meanwhile, the fatigue crack growth rate decreases due to the microstructural feature and residual compressive stress. The deformation twins in the subsurface of SNC Ti have a marked effect on the fatigue crack initiation and the crack growth. The former effect is due to the twin boundaries being preferential sites for crack initiation, while the latter is associated with the barriers that the twin boundaries pose to the propagation of dislocations. Furthermore, microstructural analysis indicates that the dislocation distribution in SNC Ti gradually becomes homogenous as fatigue processes. This homogeneous microstructure is also beneficial to the improvement of fatigue life.

  9. Pure chromosome-specific PCR libraries from single sorted chromosomes.

    PubMed Central

    VanDevanter, D R; Choongkittaworn, N M; Dyer, K A; Aten, J; Otto, P; Behler, C; Bryant, E M; Rabinovitch, P S

    1994-01-01

    Chromosome-specific DNA libraries can be very useful in molecular and cytogenetic genome mapping studies. We have developed a rapid and simple method for the generation of chromosome-specific DNA sequences that relies on polymerase chain reaction (PCR) amplification of a single flow-sorted chromosome or chromosome fragment. Previously reported methods for the development of chromosome libraries require larger numbers of chromosomes, with preparation of pure chromosomes sorted by flow cytometry, generation of somatic cell hybrids containing targeted chromosomes, or a combination of both procedures. These procedures are labor intensive, especially when hybrid cell lines are not already available, and this has limited the generation of chromosome-specific DNA libraries from nonhuman species. In contrast, a single sorted chromosome is a pure source of DNA for library production even when flow cytometric resolution of chromosome populations is poor. Furthermore, any sorting cytometer may be used with this technique. Using this approach, we demonstrate the generation of PCR libraries suitable for both molecular and fluorescence in situ hybridization studies from individual baboon and canine chromosomes, separate human homologues, and a rearranged marker chromosome from a transformed cell line. PCR libraries specific to subchromosomal regions have also been produced by sorting a small chromosome fragment. This simple and rapid technique will allow generation of nonhuman linkage maps and probes for fluorescence in situ hybridization and the characterization of marker chromosomes from solid tumors. In addition, allele-specific libraries generated by this strategy may also be useful for mapping genetic diseases. Images PMID:8016078

  10. Visual command hallucinations in a patient with pure alexia.

    PubMed

    Ffytche, D H; Lappin, J M; Philpot, M

    2004-01-01

    Around 25% of patients with visual hallucinations secondary to eye disease report hallucinations of text. The hallucinated text conveys little if any meaning, typically consisting of individual letters, words, or nonsense letter strings (orthographic hallucinations). A patient is described with textual visual hallucinations of a very different linguistic content following bilateral occipito-temporal infarcts. The hallucinations consisted of grammatically correct, meaningful written sentences or phrases, often in the second person and with a threatening and command-like nature (syntacto-semantic visual hallucinations). A detailed phenomenological interview and visual psychophysical testing were undertaken. The patient showed a classical ventral occipito-temporal syndrome with achromatopsia, prosopagnosia, and associative visual agnosia. Of particular significance was the presence of pure alexia. Illusions of colour induced by monochromatic gratings and a novel motion-direction illusion were also observed, both consistent with the residual capacities of the patient's spared visual cortex. The content of orthographic visual hallucinations matches the known specialisations of an area in the left posterior fusiform gyrus--the visual word form area (VWFA)--suggesting the two are related. The VWFA is unlikely to be responsible for the syntacto-semantic hallucinations described here as the patient had a pure alexic syndrome, a known consequence of VWFA lesions. Syntacto-semantic visual hallucinations may represent a separate category of textual hallucinations related to the cortical network implicated in the auditory hallucinations of schizophrenia.

  11. Pure rotation of a prism on a ramp

    PubMed Central

    Zhao, Zhen; Liu, Caishan; Ma, Daolin

    2014-01-01

    In this work, we study a prism with a cross section in polygon rolling on a ramp inclined at a small angle. The prism under gravity rolls purely around each individual edge, intermittently interrupted by a sequence of face collisions between the side face of the prism and the ramp. By limiting the prism in a planar motion, we propose a mathematical model to deal with the events of the impacts. With a pair of laser-Doppler vibrometers, experiments are also conducted to measure the motions of various prisms made of different materials and with different edge number. Not only are good agreements achieved between our numerical and experimental results, but also an intriguing physical phenomenon is discovered: the purely rolling motion is nearly independent of the prism's materials, yet it is closely related to the prism's geometry. Imagine that an ideal circular section can be approximately equivalent to a polygon with a large enough edge number N, the finding presented in this paper may help discover the physical mechanism of rolling friction. PMID:25197242

  12. A purely flexible lightweight membrane-type acoustic metamaterial

    NASA Astrophysics Data System (ADS)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Zhang, Weiquan; Zhang, Siwen

    2015-05-01

    This paper proposes a purely flexible lightweight membrane-type acoustic structure, wherein one kind of flexible lightweight rubber material takes the roles of mass and stiffness and another type of lightweight flexible EVA (ethylene-vinyl acetate copolymer) or plastic material functions as the localized stiffness for each unit. Because both the scatterers and base are constituted by the same material, this type of structure breaks the limitation that the metamaterials and phononic crystals need different materials with relatively large density and elasticity modulus ratios to play the roles of the scatterers and base respectively. Based on the band structures with different units, mass block shapes and size parameters, it is suggested that the shapes of the mass block can significantly affect the band structure. In addition, this type of structure could not only open a full band gap in the low-frequency range below 500 Hz, but also obtain an ultra-low-frequency bending wave band gap in the range below 100 Hz. Finally, we take into account the semi-infinite medium as a component, and calculate the sound transmission loss (STL) to evaluate the interaction between the structure and air. An experimental validation employing the cylindrical mass structure was developed to directly support the simulation results. Since the structures proposed in this study have achieved a purely flexible lightweight design, there exists an important promotion effect to realize the engineering applications of the acoustic metamaterials in practice.

  13. Pure Ultrasonic Communication in an Endemic Bornean Frog

    PubMed Central

    Arch, Victoria S.; Grafe, T. Ulmar; Gridi-Papp, Marcos; Narins, Peter M.

    2009-01-01

    Huia cavitympanum, an endemic Bornean frog, is the first amphibian species known to emit exclusively ultrasonic (i.e., >20 kHz) vocal signals. To test the hypothesis that these frogs use purely ultrasonic vocalizations for intraspecific communication, we performed playback experiments with male frogs in their natural calling sites. We found that the frogs respond with increased calling to broadcasts of conspecific calls containing only ultrasound. The field study was complemented by electrophysiological recordings from the auditory midbrain and by laser Doppler vibrometer measurements of the tympanic membrane's response to acoustic stimulation. These measurements revealed that the frog's auditory system is broadly tuned over high frequencies, with peak sensitivity occurring within the ultrasonic frequency range. Our results demonstrate that H. cavitympanum is the first non-mammalian vertebrate described to communicate with purely ultrasonic acoustic signals. These data suggest that further examination of the similarities and differences in the high-frequency/ultrasonic communication systems of H. cavitympanum and Odorrana tormota, an unrelated frog species that produces and detects ultrasound but does not emit exclusively ultrasonic calls, will afford new insights into the mechanisms underlying vertebrate high-frequency communication. PMID:19401782

  14. Direct measurement of pure absorbance spectra of living phototrophic microorganisms.

    PubMed

    Göbel, F

    1978-02-01

    The pure absorbance of turbid cell suspensions of various phototrophic microorganisms were determined by collecting the scattered light. A conventional spectrophotometer was used, equipped with an intergrating sphere as receiver unit, which allowed precise measurements of the absorbance in the range from zero to 0.1. In the wavelength range 300--1100 nm, where photosynthesis occurs, light scattered only once by a bacterial cell retains predominantly the forward direction. This allows measurements of pure absorption, when the concentration of cells which the light has to pass through is small. For example, by comparison of measurements of pigmented and nonpigmented cell suspensions of Rhodopseudomonas acidophila, it was shown that the total sum of scattered light can be collected. The best results were obtained using cuvettes with a light path of 0.1 cm or 0.2 cm to measure cell suspensions of about 0.2 mg dry weight per ml. For R. acidophila this corresponds to 1--3 cell layers. Extinction-, absorbance- and scattering spectra for R. acidophila are presented, in addition to the absorbance spectra for Rhodospirillum rubrum, Aphanocapsa and Scenedesmus.

  15. The Passive Film Characteristics of Cold Deformed Pure Copper

    NASA Astrophysics Data System (ADS)

    Fattah-Alhosseini, Arash; Naseri, Majid; Imantalab, Omid; Gholami, Davood; Haghshenas, Meysam

    2016-09-01

    In the present study, the effect of cold deformation on the electrochemical and passive behaviors of pure copper in 0.01 M NaOH solution was investigated. The dislocation density in cold deformation was calculated using a recently developed JAVA-based software, materials analysis using diffraction, based on Rietveld's whole x-ray pattern fitting methodology. At the thickness reduction of 70%, the microhardness measured as 125.30 HV, which is 1.56 times than that in the annealed pure copper (80.25 HV). Potentiodynamic polarization plots and electrochemical impedance spectroscopy measurements showed that increasing the cold deformation offers better conditions for forming the passive films. In the Mott-Schottky analysis, no evidence for n-type behavior was obtained which indicates that the oxygen vacancies and the copper interstitials did not have any significant population density in the passive films. Also, this analysis revealed that with increasing cold deformation, the acceptor density of the passive films decreased.

  16. The influence of anthropogenic pure iron on magnetic properties of indoor dust.

    NASA Astrophysics Data System (ADS)

    Górka-Kostrubiec, Beata; Teisseyre-Jeleńska, Maria

    2015-04-01

    In our earlier work Górka-Kostrubiec et al., (2014) we presented the consistent study of magnetic properties of indoor dust involved about 200 apartments in various locations in Warsaw (Poland), which were affected by various sources of external pollution. Detailed measurements of magnetic properties of dust revealed linear relation between the magnetic susceptibility and the concentration of toxic metals and trace elements expressed by the Tomlinson Pollution Load Index (PLI). The data was divided into two sets which differ in the slope of each branch. Although them both showing linear relation of PLI(χ). The aim of the present study is to find the differences in the magnetic mineralogy, structure and grain size between dust samples belonging to the 1st and 2nd sets revealing the relation of PLI versus χ. For this purpose, the dust samples representing the maximum, middle and low values of PLI on both branches were selected. For these samples the temperature-dependent magnetic parameter M(T) and the hysteresis loops were examined. The curves of M (T) showed two magnetic phases - magnetite and pure Fe in variable proportions. For samples belonging to the first branch the contribution of pure Fe to magnetic fraction calculated from the decrease of magnetization on the M (T) curves was in the range from 29% to 38%. The higher contribution, more than 74% was observed for the second branch. The heating up to 800oC caused the chemical changes in the magnetic mineralogy, which are demonstrated as an increase in magnetization at room temperature after cooling. The samples from the 1st branch showed higher changes than the samples for the 2nd one. This result indicates that different types of chemical reactions occur during heating in both groups. In order to observe changes in the structure of mineralogy and grain size the hysteresis loops for the samples before and after heating to 800° C were determined. Very narrow loops (with low values of Hc and Mrs) were

  17. The elevated temperature tensile properties of S-200E commercially pure beryllium

    SciTech Connect

    Henshall, G.A.; Torres, S.G.; Hanafee, J.E.

    1995-09-01

    The tensile properties of commercially pure beryllium are sensitive to temperature, impurity content, texture, grain size, and prior processing. Therefore, tensile tests have been conducted using the commercially pure S-200E Be commonly employed at Lawrence Livermore National Laboratory. These experiments were performed at temperatures ranging from 300 to 1100{degrees}C in the longitudinal and transverse orientations at the quasi-static strain rate of 5.5 x 10{sup -4} s{sup -1}. The results of these experiments reveal that the stress-strain curve is smooth, ie. without yield points or serrations, over the entire temperature range studied. The yield stress (YS) and ultimate tensile stress (UTS) decrease monotonically with increasing temperature. Similar strengths were measured for both the longitudinal and transverse orientations, with the latter exhibiting slightly lower YS and UTS values. The measured failure elongation (e{sub f}) vs. temperature curve is complex due to the competing effects of increasing basal-plane fracture stress with increasing temperature combined with the presence of hot shortness at intermediate temperatures. The latter is believed to be caused, at least partially, by the presence of free aluminum impurities at the grain boundaries. This hypothesis is supported by the measured increase in e{sub f} at 700{degrees}C following a 100-hr anneal at 750{degrees}C, which would remove free Al from the grain boundaries. Texture also was found to influence e{sub f}. The favorable orientation of the basal planes for initiation and propagation of cleavage cracks in longitudinal specimens results in a significantly decreased failure elongation compared with the transverse orientation. The effects of testing temperature and specimen orientation on the reduction in area were found to be similar to those described for e{sub f}.

  18. Numerical Analysis of Temperature Gradients and Interface Shape During Directional Solidification of Al and Al-Cu Alloy Under Microgravity Conditions

    NASA Technical Reports Server (NTRS)

    Bune, Andris V.; Sen, Subhayu; Stefanescu, Doru M.; Curreri, Peter A.

    1999-01-01

    Numerical modeling was undertaken to analyze the influence of radial thermal gradient on solid/liquid interface shape and convection patterns during solidification of pure Al and Al-4 wt. % Cu alloy. Steady state calculations were performed for different gravity levels and orientations. Furthermore, transient modeling was undertaken to investigate effect of the solidification velocity. The furnace configuration used in this analysis is the proposed International Space Station Furnace. Results from a thermal model of the furnace core were used as initial boundary conditions for solidification modeling. The Solidification model was adopted from previous work and was based on the finite element code FIDAP. Thermocouple data and quenched interface shape from a pure Al sample flown on the Life Sciences and Microgravity Spacelab (LMS) mission, July 1996 was used for model validation. Good agreement was obtained between the predicted interface shape and that measured from the quenched LMS sample. It was found that the imposed temperature boundary condition must be sufficiently smooth for the heat fluxes in the model to be self-consistent. The model predicted that alloy sample Al-Cu is more sensitive to variations in the gravity level compared to pure Al. For Al-Cu alloy, solute diffusivity is approximately 10(exp 4) times smaller than thermal diffusivity of pure Al. Hence, in a microgravity environment the weak convection has no measurable effect on the heat fluxes, but is still strong enough to affect concentration distribution. Since the alloy melting temperature is determined by concentration the interface shape depends on the level of convection. This was found not to be the case for pure metal.

  19. Characteristics of aluminum-reinforced γ-LiAlO2 matrices for molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Lee, Jong-Jin; Choi, Hyun-Jong; Hyun, Sang-Hoon; Im, Hee-Chun

    2008-05-01

    A key component in molten carbonate fuel cells (MCFCs) is the electrolyte matrix, which provides both ionic conduction and gas sealing. During initial MCFC stack start-up and operation (650 °C), the matrix experiences both mechanical and thermal stresses as a result of the difference in thermal expansion coefficients between the LiAlO2 ceramic particles and the carbonate electrolyte that causes cracking of the matrix. A pure γ-LiAlO2 matrix, however, has poor mechanical strength and low thermal expansion coefficients. In this study, fine γ-LiAlO2 powders and pure Al (3/20/50 μm)/Li2CO3 particles are used as a matrix and as reinforcing materials, respectively. The Al phase transforms completely into γ-LiAlO2 at 650 °C within 10 h. The mechanical strength of these matrices (283.48 gf mm-2) increases nearly threefold relative to that of a pure γ-LiAlO2 matrix (104.01 gf mm-2). The mismatch of the thermal expansion coefficient between the matrix and electrolyte phases can be controlled by adding Al particles, which results in improved thermal stability in the initial heating-up step. In unit-cell and thermal-cycling tests, the optimized matrix demonstrates superior performance over pure γ-LiAlO2 matrices.

  20. 77 FR 66911 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel PURE INSANITY; Invitation for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Maritime Administration Requested Administrative Waiver of the Coastwise Trade Laws: Vessel PURE INSANITY... of the vessel PURE INSANITY is: Intended Commercial Use of Vessel: ``Vessel Chartering''...

  1. ℬ(H) has a pure state that is not multiplicative on any masa

    PubMed Central

    Akemann, Charles; Weaver, Nik

    2008-01-01

    Assuming the continuum hypothesis, we prove that ℬ(H) has a pure state whose restriction to any masa is not pure. This resolves negatively old conjectures of Kadison and Singer and of Anderson. PMID:18378909

  2. (Al, Er) co-doped ZnO nanoparticles for photodegradation of rhodamine blue

    NASA Astrophysics Data System (ADS)

    Ghomri, R.; Shaikh, M. Nasiruzzaman; Ahmed, M. I.; Bououdina, M.; Ghers, M.

    2016-10-01

    Pure and co-doped (Al, Er) ZnO nanoparticles (NPs) have been synthesized by hydrothermal method using (Zn, Er and Al) nitrates. X-ray diffraction patterns reveal the formation of single phase of ZnO würtzite-type structure. The crystallite size for pure ZnO is in the order of 26.5 nm which decreases up to the range 14.2-22.0 nm after (Al, Er) co-doping. SEM micrographs show that the specimen is composed of regular spherical particles in the nanoscale regime with homogeneous size distribution and high tendency to agglomeration. FTIR spectra exhibit absorption lines located at wavenumbers corresponding to vibration modes between the constituent atoms. Raman spectra recorded under excitation ( λ exc = 632.8 nm) reveal peaks related to modes of transverse and longitudinal optical phonons of the würtzite ZnO structure. The energy band gap E g of ZnO:(Al, Er) NPs ranges in 3.264-3.251 eV. The photocatalytic activity of pure and co-doped (Al, Er) ZnO NPs was evaluated by the photodegradation of rhodamine blue under an irradiation of wavelength 554 nm. It is found that a photodegradation rate above 90 % could be achieved for a period of time of 40 min for pure ZnO and 120 min for (Al, Er) co-doped ZnO. A photodegradation mechanism is proposed.

  3. Equation of state for pure fluids at critical temperature

    NASA Astrophysics Data System (ADS)

    B. Khasare, S.

    2012-04-01

    In this paper, we employ the concept of probability for creating a cavity with diameter d in fluid along with the perturbation and variation approach, and develop an equation of state (EOS) for a hard sphere (HS) and Lennard—Jones (LJ) fluids. A suitable axiomatic form for surface tension S(r) is assumed for the pure fluid, with r as a variable. The function S(r) has an arbitrary parameter m. S(r) = A + B(d/r)/[1 + m(d/r)]. We use the condition in terms of radial distribution function G(λd,η) containing the self-consistent parameter λ and the condition of continuity at r = d/2 to determine A and B. A different EOS can be obtained with a suitable choice of m and the EOS has a lower root-mean-square deviation than that of Barker—Henderson BH2 for LJ fluids.

  4. RF Sputtering for preparing substantially pure amorphous silicon monohydride

    DOEpatents

    Jeffrey, Frank R.; Shanks, Howard R.

    1982-10-12

    A process for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicon produced by reactive rf sputtering of an amorphous silicon target. There is provided a chamber with an amorphous silicon target and a substrate therein with the substrate and the target positioned such that when rf power is applied to the target the substrate is in contact with the sputtering plasma produced thereby. Hydrogen and argon are fed to the chamber and the pressure is reduced in the chamber to a value sufficient to maintain a sputtering plasma therein, and then rf power is applied to the silicon target to provide a power density in the range of from about 7 watts per square inch to about 22 watts per square inch to sputter an amorphous silicon hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

  5. Preparation of Pure Plutonium Metal Standards for Nondestructive Assay

    SciTech Connect

    S. -T. Hsue; J. E. Stewart; M. S. Krick

    2000-11-01

    To calibrate neutron coincidence and neutron multiplicity counters for passive assay of plutonium, certain detector parameters must be determined. When one is using small plutonium metal samples, biases can be introduced from non-zero multiplication and impurities. This paper describes preparing small, pure plutonium metal standards with well-known geometries to enable accurate multiplication corrections and with acceptably low levels of impurities. To minimize multiplication, these standards are designed as 2-cm-diameter foils with varying thicknesses and masses of 1.4, 3.6, and 7.2 g plutonium. These standards will significantly improve characterization and calibration of neutron coincidence and multiplicity counters. They can also be equally useful for gamma-ray spectrometry and calorimetry. Five sets will be made: four for other US Department of Energy plutonium facilities, and one set to remain at Los Alamos. We will also describe other nondestructive assay standards that are planned for the next few years.

  6. Distribution of G concurrence of random pure states

    NASA Astrophysics Data System (ADS)

    Cappellini, Valerio; Sommers, Hans-Jürgen; Życzkowski, Karol

    2006-12-01

    The average entanglement of random pure states of an N×N composite system is analyzed. We compute the average value of the determinant D of the reduced state, which forms an entanglement monotone. Calculating higher moments of the determinant, we characterize the probability distribution P(D) . Similar results are obtained for the rescaled Nth root of the determinant, called the G concurrence. We show that in the limit N→∞ this quantity becomes concentrated at a single point G⋆=1/e . The position of the concentration point changes if one consider an arbitrary N×K bipartite system, in the joint limit N,K→∞ , with K/N fixed.

  7. Pure spin current devices based on ferromagnetic topological insulators

    PubMed Central

    Götte, Matthias; Joppe, Michael; Dahm, Thomas

    2016-01-01

    Two-dimensional topological insulators possess two counter propagating edge channels with opposite spin direction. Recent experimental progress allowed to create ferromagnetic topological insulators realizing a quantum anomalous Hall (QAH) state. In the QAH state one of the two edge channels disappears due to the strong ferromagnetic exchange field. We investigate heterostructures of topological insulators and ferromagnetic topological insulators by means of numerical transport calculations. We show that spin current flow in such heterostructures can be controlled with high fidelity. Specifically, we propose spintronic devices that are capable of creating, switching and detecting pure spin currents using the same technology. In these devices electrical currents are directly converted into spin currents, allowing a high conversion efficiency. Energy independent transport properties in combination with large bulk gaps in some topological insulator materials may allow operation even at room temperature. PMID:27782187

  8. Acquired pure red cell aplasia: updated review of treatment

    PubMed Central

    Sawada, Kenichi; Fujishima, Naohito; Hirokawa, Makoto

    2008-01-01

    Pure red cell aplasia (PRCA) is a syndrome characterized by a severe normocytic anaemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Primary PRCA, or secondary PRCA which has not responded to treatment of the underlying disease, is treated as an immunologically-mediated disease. Although vigorous immunosuppressive treatments induce and maintain remissions in a majority of patients, they carry an increased risk of serious complications. Corticosteroids were used in the treatment of PRCA and this has been considered the treatment of first choice although relapse is not uncommon. Cyclosporine A (CsA) has become established as one of the leading drugs for treatment of PRCA. However, common concerns have been the number of patients treated with CsA who achieve sustained remissions and the number that relapse. This article reviews the current status of CsA therapy and compares it to other treatments for diverse PRCAs. PMID:18510682

  9. Unexpected magnetization in highly pure metal oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Hanna, C. B.; Alanko, Gordon; Beausoleil, Boone; Chess, Jordan; Thurber, Aaron; Punnoose, Alex

    2012-02-01

    We report the synthesis and characterization of a large set of highly pure metal oxide (CeO2, SnO2 and ZnO) nanoparticles of ultra-small size (2-10 nm). While the metal oxide systems in this study are non-magnetic as bulk materials, our prepared nanoparticles possess an unexpected small room-temperature ferromagnetic magnetization on the order of 0.001 emu/g. This magnetization is shown to not be a result of magnetic impurities, and is discussed in terms of modification of the electronic structure and crystal lattice. These nanoparticles were thoroughly characterized in their size and phase by x-ray diffraction, morphology by transmission electron microscopy, chemical state and elemental purity by x-ray photoelectron spectroscopy, electronic bandgap by UV-vis absorption spectroscopy, and magnetic properties by vibrating sample magnetometry and electron paramagnetic resonance.

  10. Irradiation hardening of pure tungsten exposed to neutron irradiation

    NASA Astrophysics Data System (ADS)

    Hu, Xunxiang; Koyanagi, Takaaki; Fukuda, Makoto; Kumar, N. A. P. Kiran; Snead, Lance L.; Wirth, Brian D.; Katoh, Yutai

    2016-11-01

    Pure tungsten samples have been neutron irradiated in HFIR at 90-850 °C to 0.03-2.2 dpa. A dispersed barrier hardening model informed by the available microstructure data has been used to predict the hardness. Comparison of the model predictions and the measured Vickers hardness reveals the dominant hardening contribution at various irradiation conditions. For tungsten samples irradiated in HFIR, the results indicate that voids and dislocation loops contributed to the hardness increase in the low dose region (<0.3 dpa), while the formation of intermetallic second phase precipitation, resulting from transmutation, dominates the radiation-induced strengthening beginning with a relatively modest dose (>0.6 dpa). The precipitate contribution is most pronounced for the HFIR irradiations, whereas the radiation-induced defect cluster microstructure can rationalize the entirety of the hardness increase observed in tungsten irradiated in the fast neutron spectrum of Joyo and the mixed neutron spectrum of JMTR.

  11. Fundamental flame velocities of pure hydrocarbons II : alkadienes

    NASA Technical Reports Server (NTRS)

    Levine, Oscar; Wong, Edgar L; Gerstein, Melvin

    1950-01-01

    Data are presented for the fundamental flame velocities of 10 pure alkadienes that have isolated, conjugated, or cumulative double-bond systems. On the basis of this limited amount of data and the flame velocities previously reported, it is concluded that unsaturation changes the flame velocity in the order alkanes ? alkenes ? alkadienes with isolated double bonds ?= alkadienes with conjugated double bonds ? alkadienes with cumulative double bonds ?= alkynes. There were no significant differences in the flame velocities of cis and trans 1,3-pentadiene. The alkadienes 1,2-pentadiene and 2,3-pentadiene, with different positions of the cumulative double bond in the straight chain, have similar flame velocities. Methyl substitution in a hydrocarbon reduces the flame velocity; the extent of the reduction increases with the degree of unsaturation of the hydrocarbon.

  12. Pure consciousness: distinct phenomenological and physiological correlates of "consciousness itself".

    PubMed

    Travis, F; Pearson, C

    2000-01-01

    This paper explores subjective reports and physiological correlates of the experience of "consciousness itself"--self awareness isolated from the processes and objects of experience during Transcendental Meditation practice. Subjectively, this state is characterized by the absence of the very framework (time, space, and body sense) and content (qualities of inner and outer perception) that define waking experiences. Physiologically, this state is distinguished by the presence of apneustic breathing, autonomic orienting at the onset of breath changes, and increases in the frequency of peak EEG power. A model, called the junction point model, is presented that integrates pure consciousness with waking, dreaming, or sleeping. It could provide a structure to generate a coherent program of research to test the full range of consciousness and so enable us to understand what it means to be fully human.

  13. Pure Consciousness: Distinct Phenomenological and Physiological Correlates of "Consciousness Itself"

    PubMed

    Travis; Pearson

    1999-01-01

    This paper explores subjective reports and physiological correlates of the experience of "consciousness itself" - self awareness isolated from the processes and objects of experience during Transcendental Meditation practice. Subjectively, this state is characterized by the absence of the very framework (time, space, and body sense) and content (qualities of inner and outer perception) that define waking experiences. Physiologically, this state is distinguished by the presence of apneustic breathing, autonomic orienting at the onset of breath changes, and increases in the frequency of peak EEG power. A model, called the junction point model, is presented that integrates pure consciousness with waking, dreaming, or sleeping. It could provide a structure to generate a coherent program of research to test the full range of consciousness and so enable us to understand what it means to be fully human.

  14. Pure Kana agraphia as a manifestation of graphemic buffer impairment.

    PubMed

    Kokubo, K; Suzuki, K; Yamadori, A; Satou, K

    2001-04-01

    We report a left-handed man who demonstrated a pure agraphia limited to words written in Kana characters (syllabograms) following a right putaminal hemorrhage. Writing words in Kanji characters (logograms) was well preserved. His performance in Kana writing was characterized by intact ability to write single syllables, error increase in the second half of words directly proportional to the word length and correct but slow writing of words using kana blocks. Errors were more prominent in Hiragana words than Katakana words which are usually used to transcribe foreign words. Acoustic-grapheme sequencing per se was not impaired as shown by his correct performance in arranging character blocks. These findings suggest selective damage to the graphemic buffer, a module that temporarily maintains the graphemic representation elaborated in previous stages before it is sent to the peripheral systems for its motor realization.

  15. Quantum benchmarks for pure single-mode Gaussian states.

    PubMed

    Chiribella, Giulio; Adesso, Gerardo

    2014-01-10

    Teleportation and storage of continuous variable states of light and atoms are essential building blocks for the realization of large-scale quantum networks. Rigorous validation of these implementations require identifying, and surpassing, benchmarks set by the most effective strategies attainable without the use of quantum resources. Such benchmarks have been established for special families of input states, like coherent states and particular subclasses of squeezed states. Here we solve the longstanding problem of defining quantum benchmarks for general pure Gaussian single-mode states with arbitrary phase, displacement, and squeezing, randomly sampled according to a realistic prior distribution. As a special case, we show that the fidelity benchmark for teleporting squeezed states with totally random phase and squeezing degree is 1/2, equal to the corresponding one for coherent states. We discuss the use of entangled resources to beat the benchmarks in experiments. PMID:24483875

  16. Distribution of G concurrence of random pure states

    SciTech Connect

    Cappellini, Valerio; Zyczkowski, Karol

    2006-12-15

    The average entanglement of random pure states of an NxN composite system is analyzed. We compute the average value of the determinant D of the reduced state, which forms an entanglement monotone. Calculating higher moments of the determinant, we characterize the probability distribution P(D). Similar results are obtained for the rescaled Nth root of the determinant, called the G concurrence. We show that in the limit N{yields}{infinity} this quantity becomes concentrated at a single point G{sub *}=1/e. The position of the concentration point changes if one consider an arbitrary NxK bipartite system, in the joint limit N,K{yields}{infinity}, with K/N fixed.

  17. M553 sphere forming experiment: Pure nickel specimen evaluation

    NASA Technical Reports Server (NTRS)

    Johnson, P. C.; Peters, E. T.

    1973-01-01

    A region or cap of very fine two-dimensional surface growth structure was observed at the top of three of the six pure nickel flight specimens. Such two-dimensional surface growth structures have been observed both on the ground-based specimens and on other surface areas of the flight specimens. However, the fine structures observed on the three flight samples are at least an order of magnitude finer than those previously observed, and resemble similar localized, fine, two-dimensional surface structures observed in both ground and flight specimens for the nickel alloys. The two-dimensional growth areas consist primarily of fine equiaxed grains, specimen SL-2.6, fine dendrites, specimen SL-2.5, or a core of fine equiaxed grains surrounded by a ring of fine dendrites, specimen SL-1.9.

  18. First observation of muonic hyperfine effects in pure deuterium

    SciTech Connect

    Kammel, P.; Breunlich, W.H.; Cargnelli, M.; Mahler, H.G.; Zmeskal, J.; Bertl, W.H.; Petitjean, C.

    1983-11-01

    We discovered a strong hyperfine dependence of the resonant formation process of d..mu..d mesomolecules, while detecting neutrons from muon-catalyzed fusion in pure deuterium gas at 34 K. This new effect enabled us to observe directly transitions between hyperfine states of the ..mu..d atom for the first time and to determine an accurate experimental value for this transition rate. Our analysis demonstrates the importance of hyperfine effects for the quantitative understanding of the mechanism of resonant d..mu..d formation. Moreover, this experiment indicates that the resonant formation process is a powerful tool for a refined spectroscopy of d..mu..d bound states. Finally, the detailed knowledge about mesoatomic and mesomolecular processes obtained in this work provides valuable information for the analysis of experiments on the elementary muon-capture process in deuterium.

  19. Revision of Spin Echoes in Pure Nuclear Quadrupole Resonance

    NASA Astrophysics Data System (ADS)

    Meriles, C. A.

    2001-04-01

    Goldman's spin-1/2 formalism has been used for describing the response of an I=3/2 spin system to a two-pulse sequence in a pure nuclear quadrupole resonance experiment. A detailed analysis of the polarization evolution and quadrupolar echo generation is carried out through the use of explicit expressions for secular homo- and heteronuclear dipolar interactions. In striking contrast with previous studies, it is predicted that Van Vleck's second moments governing a classical solid-echo or Hahn sequence differ from those obtained by equivalent means in magnetic resonance. In fact, it is shown that, although measured moments still complement each other, the combined use of standard sequences does not allow the separate determination of homo- and heteronuclear dipolar contributions to the linewidth, not even in an indirect manner. In this context, the importance and potential usefulness of a crossed coil probe are also briefly discussed.

  20. Pure scaling operators at the integer quantum Hall plateau transition.

    PubMed

    Bondesan, R; Wieczorek, D; Zirnbauer, M R

    2014-05-01

    Stationary wave functions at the transition between plateaus of the integer quantum Hall effect are known to exhibit multifractal statistics. Here we explore this critical behavior for the case of scattering states of the Chalker-Coddington network model with point contacts. We argue that moments formed from the wave amplitudes of critical scattering states decay as pure powers of the distance between the points of contact and observation. These moments in the continuum limit are proposed to be correlation functions of primary fields of an underlying conformal field theory. We check this proposal numerically by finite-size scaling. We also verify the conformal field theory prediction for a three-point function involving two primary fields.

  1. Pure red cell aplasia following autoimmune hemolytic anemia: an enigma.

    PubMed

    Saha, M; Ray, S; Kundu, S; Chakrabarti, P

    2013-01-01

    A 26-year-old previously healthy female presented with a 6-month history of anemia. The laboratory findings revealed hemolytic anemia and direct antiglobulin test was positive. With a diagnosis of autoimmune hemolytic anemia (AIHA), prednisolone was started but was ineffective after 1 month of therapy. A bone marrow trephine biopsy revealed pure red cell aplasia (PRCA) showing severe erythroid hypoplasia. The case was considered PRCA following AIHA. This combination without clear underlying disease is rare. Human parvovirus B19 infection was not detected in the marrow aspirate during reticulocytopenia. The patient received azathioprine, and PRCA improved but significant hemolysis was once again documented with a high reticulocyte count. The short time interval between AIHA and PRCA phase suggested an increased possibility of the evolution of a single disease.

  2. Light-Induced Metastability in Pure and Hydrogenated Amorphous Silicon

    SciTech Connect

    Queen, D. R.; Liu, X.; Karel, J.; Wang, Q.; Crandall, Richard S.; Metcalf, T. H.; Hellman, F.

    2015-10-01

    Light soaking is found to increase the specific heat C and internal friction Q-1 of pure (a-Si) and hydrogenated (a-Si:H) amorphous silicon. At the lowest temperatures, the increases in C and Q-1 are consistent with an increased density of two-level systems (TLS). The light-induced increase in C persists to room temperature. Neither the sound velocity nor shear modulus change with light soaking indicating that the Debye specific heat is unchanged which suggests that light soaking creates localized vibrational modes in addition to TLS. The increase can be reversibly added and removed by light soaking and annealing, respectively, suggesting that it is related to the Staebler-Wronski effect (SWE), even in a-Si without H, and involves a reversible nanoscale structural rearrangement that is facilitated by, but does not require, H to occur.

  3. Nanosized graphene crystallite induced strong magnetism in pure carbon films.

    PubMed

    Wang, Chao; Zhang, Xi; Diao, Dongfeng

    2015-03-14

    We report strong magnetism in pure carbon films grown by electron irradiation assisted physical vapor deposition in electron cyclotron resonance plasma. The development of graphene nanocrystallites in the amorphous film matrix, and the dependence of the magnetic behavior on amorphous, nanocrystallite and graphite-like structures were investigated. Results were that the amorphous structure shows weak paramagnetism, graphene nanocrystallites lead to strong magnetization, and graphite-like structures corresponded with a lower magnetization. At a room temperature of 300 K, the highest saturation magnetization of 0.37 emu g(-1) was found in the nanosized graphene nanocrystallite structure. The origin of strong magnetism in nanocrystallites was ascribed to the spin magnetic moment at the graphene layer edges.

  4. Homogeneous switching mechanism in pure polyvinylidene fluoride ultrathin films

    NASA Astrophysics Data System (ADS)

    Tian, B. B.; Chen, L. F.; Liu, Y.; Bai, X. F.; Wang, J. L.; Sun, Sh.; Yuan, G. L.; Sun, J. L.; Dkhil, B.; Meng, X. J.; Chu, J. H.

    2015-08-01

    Polarization switching kinetics is one of the key issues for future development of nanoelectronic devices based on ferroelectrics. Up to now, such kinetics still remains poorly studied despite its crucial impact on the device performances. Here, the switching mechanism in 11-nm-thick ferroelectric films of pure homopolymer of polyvinylidene fluoride is investigated. While the usual mechanism involves nucleation and growth of domains, a homogeneous ferroelectric switching is evidenced in such ultrathin films. Indeed, the dependence of the switching rate on applied voltage reveals a critical behavior with the existence of a true threshold field (of ˜0.26 GV /m ) which is required to overcome the energy barrier to reverse the whole polarization homogeneously as suggested by Landau-Ginzburg mean-field theory. Such finding not only supports few previous works but also raises the question on the general aspect of such homogeneous mechanism that might exist in any other nanoscale ferroelectric materials.

  5. Light-induced metastability in pure and hydrogenated amorphous silicon

    NASA Astrophysics Data System (ADS)

    Queen, D. R.; Liu, X.; Karel, J.; Wang, Q.; Crandall, R. S.; Metcalf, T. H.; Hellman, F.

    2015-10-01

    Light soaking is found to increase the specific heat C and internal friction Q-1 of pure (a-Si) and hydrogenated (a-Si:H) amorphous silicon. At the lowest temperatures, the increases in C and Q-1 are consistent with an increased density of two-level systems (TLS). The light-induced increase in C persists to room temperature. Neither the sound velocity nor shear modulus change with light soaking indicating that the Debye specific heat is unchanged which suggests that light soaking creates localized vibrational modes in addition to TLS. The increase can be reversibly added and removed by light soaking and annealing, respectively, suggesting that it is related to the Staebler-Wronski effect (SWE), even in a-Si without H, and involves a reversible nanoscale structural rearrangement that is facilitated by, but does not require, H to occur.

  6. Mathematical properties and bounds on haplotyping populations by pure parsimony.

    PubMed

    Wang, I-Lin; Chang, Chia-Yuan

    2011-06-01

    Although the haplotype data can be used to analyze the function of DNA, due to the significant efforts required in collecting the haplotype data, usually the genotype data is collected and then the population haplotype inference (PHI) problem is solved to infer haplotype data from genotype data for a population. This paper investigates the PHI problem based on the pure parsimony criterion (HIPP), which seeks the minimum number of distinct haplotypes to infer a given genotype data. We analyze the mathematical structure and properties for the HIPP problem, propose techniques to reduce the given genotype data into an equivalent one of much smaller size, and analyze the relations of genotype data using a compatible graph. Based on the mathematical properties in the compatible graph, we propose a maximal clique heuristic to obtain an upper bound, and a new polynomial-sized integer linear programming formulation to obtain a lower bound for the HIPP problem.

  7. The Case for Research in Pure Physics in Developing Countries

    NASA Astrophysics Data System (ADS)

    Mweene, H. V.

    Science and technology are the keys to modern economic development. But, it has often been argued that poor countries cannot really afford to support research, or that they should at most devote their efforts to applied science only. The scientific knowledge necessary for development would then be partly or wholly obtained from other countries. In this paper, the case will be argued that developing countries cannot afford to leave research, both pure and applied, to the developed countries and that the only way the developing world is going to solve its problems is through development driven by their own research activities. With reference to physics, the importance of research by researchers in poor countries is explained. Lastly, it is outlined how the logistics of doing research under the difficult conditions prevailing in poor countries can be managed.

  8. Modularity of music: evidence from a case of pure amusia

    PubMed Central

    Piccirilli, M.; Sciarma, T.; Luzzi, S.

    2000-01-01

    A case of pure amusia in a 20 year old left handed non-professional musician is reported. The patient showed an impairment of music abilities in the presence of normal processing of speech and environmental sounds. Furthermore, whereas recognition and production of melodic sequences were grossly disturbed, both the recognition and production of rhythm patterns were preserved. This selective breakdown pattern was produced by a focal lesion in the left superior temporal gyrus. This case thus suggests that not only linguistic and musical skills, but also melodic and rhythmic processing are independent of each other. This functional dissociation in the musical domain supports the hypothesis that music components have a modular organisation. Furthermore, there is the suggestion that amusia may be produced by a lesion located strictly in one hemisphere and that the superior temporal gyrus plays a crucial part in melodic processing.

 PMID:10990522

  9. Random unitary evolution model of quantum Darwinism with pure decoherence

    NASA Astrophysics Data System (ADS)

    Balanesković, Nenad

    2015-10-01

    We study the behavior of Quantum Darwinism [W.H. Zurek, Nat. Phys. 5, 181 (2009)] within the iterative, random unitary operations qubit-model of pure decoherence [J. Novotný, G. Alber, I. Jex, New J. Phys. 13, 053052 (2011)]. We conclude that Quantum Darwinism, which describes the quantum mechanical evolution of an open system S from the point of view of its environment E, is not a generic phenomenon, but depends on the specific form of input states and on the type of S-E-interactions. Furthermore, we show that within the random unitary model the concept of Quantum Darwinism enables one to explicitly construct and specify artificial input states of environment E that allow to store information about an open system S of interest with maximal efficiency.

  10. Random unitary evolution model of quantum Darwinism with pure decoherence

    NASA Astrophysics Data System (ADS)

    Balanesković, Nenad

    2015-10-01

    We study the behavior of Quantum Darwinism [W.H. Zurek, Nat. Phys. 5, 181 (2009)] within the iterative, random unitary operations qubit-model of pure decoherence [J. Novotný, G. Alber, I. Jex, New J. Phys. 13, 053052 (2011)]. We conclude that Quantum Darwinism, which describes the quantum mechanical evolution of an open system S from the point of view of its environment E, is not a generic phenomenon, but depends on the specific form of input states and on the type of S- E-interactions. Furthermore, we show that within the random unitary model the concept of Quantum Darwinism enables one to explicitly construct and specify artificial input states of environment E that allow to store information about an open system S of interest with maximal efficiency.

  11. Microbial growth and the effects of mild acidification and preservatives in refrigerated sweetpotato puree

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Refrigerated sweetpotato puree is a convenient form of this vegetable to be used as an ingredient in formulated foods. The microbiology of refrigerated sweetpotato puree during storage for up to 5 weeks, was evaluated. Since puree is made by comminuting steam cooked sweetpotatoes prior to refriger...

  12. About Being Pure and Natural: Understandings of Pre-Service Primary Teachers

    ERIC Educational Resources Information Center

    Lake, David

    2005-01-01

    In an investigation of 149 pre-service primary teachers' understanding of the terms "pure" and "natural," the participants were asked to provide definitions of the two words, and classify various substances including drugs of abuse, pharmaceuticals, nutriceuticals, and household substances as either natural or not natural, and as pure or not pure.…

  13. Entanglement of three-qubit pure states in terms of teleportation capability

    SciTech Connect

    Lee, Soojoon; Joo, Jaewoo; Kim, Jaewan

    2005-08-15

    We define an entanglement measure, called the partial tangle, which represents the residual two-qubit entanglement of a three-qubit pure state. By its explicit calculations for three-qubit pure states, we show that the partial tangle is closely related to the faithfulness of a teleportation scheme over a three-qubit pure state.

  14. Quality of life in purely ocular myasthenia in Japan

    PubMed Central

    2014-01-01

    Background Since there has been no conclusive evidence regarding the treatment of ocular myasthenia, treatment guidelines were recently issued by the European Federation of Neurological Societies/European Neurological Society (EFNS/ENS). However, the therapeutic outcomes concerning the quality-of-life (QOL) of patients with ocular myasthenia are not yet fully understood. Methods We investigated the therapeutic outcomes of patients with purely ocular myasthenia in a multicenter cross-sectional survey in Japan. To evaluate the severity of ocular symptoms, we used the ocular-quantitative MG (QMG) score advocated by Myasthenia Gravis Foundation of America. We used the Japanese translated version of the MG-QOL15, a self-appraised scoring system. Results Of 607 myasthenia gravis (MG) patients with an observation-duration of illness ≥ 2 years, the cases of 123 patients (20%) were limited to ocular muscles (purely ocular myasthenia). During the entire clinical course, 81 patients experienced both ptosis and diplopia, 36 had ptosis alone, and six had diplopia alone. Acetyl-cholinesterase inhibitors and prednisolone were used in 98 and 52 patients, respectively. Treatment improved ocular symptoms, with the mean reduction in ocular-QMG score of 2.3 ± 1.8 points. However, 47 patients (38%) failed to gain minimal manifestation or a better status. Patients with unfavorable outcomes also self-reported severe QOL impairment. Multivariate analyses showed that the pretreatment ocular-QMG score was associated with unfavorable outcomes, but not associated with the patient’s QOL. Conclusion A treatment strategy designed in accord with a patient's ocular presentation must be considered in order to improve ocular symptoms and the patient's QOL. PMID:24996227

  15. Lindane removal by pure and mixed cultures of immobilized actinobacteria.

    PubMed

    Saez, Juliana M; Benimeli, Claudia S; Amoroso, María J

    2012-11-01

    Lindane (γ-HCH) is an organochlorine insecticide that has been widely used in developing countries. It is known to persist in the environment and can cause serious health problems. One of the strategies adopted to remove lindane from the environment is bioremediation using microorganisms. Immobilized cells present advantages over free suspended cells, like their high degradation efficiency and protection against toxins. The aims of this work were: (1) To evaluate the ability of Streptomyces strains immobilized in four different matrices to remove lindane, (2) To select the support with optimum lindane removal by pure cultures, (3) To assay the selected support with consortia and (4) To evaluate the reusability of the immobilized cells. Four Streptomyces sp. strains had previously shown their ability to grow in the presence of lindane. Lindane removal by microorganisms immobilized was significantly higher than in free cells. Specifically immobilized cells in cloth sachets showed an improvement of around 25% in lindane removal compared to the abiotic control. Three strains showed significantly higher microbial growth when they were entrapped in silicone tubes. Strains immobilized in PVA-alginate demonstrated lowest growth. Mixed cultures immobilized inside cloth sachets showed no significant enhancement compared to pure cultures, reaching a maximum removal of 81% after 96 h for consortium I, consisting of the four immobilized strains together. Nevertheless, the cells could be reused for two additional cycles of 96 h each, obtaining a maximum removal efficiency of 71.5% when each of the four strains was immobilized in a separate bag (consortium III). PMID:22840534

  16. Bimodality of Pure Compaction Bands, Buckskin Gulch, Utah

    NASA Astrophysics Data System (ADS)

    Klimczak, C.; Byrne, P. K.

    2015-12-01

    The exposures of the aeolian Navajo Sandstone at Buckskin Gulch, Utah, have received much attention for their spectacular displays of compaction bands. These bands are described as tabular zones of reduced porosity, and are generally categorized into shear-enhanced compaction bands (SECBs), which accommodate equal amounts of compaction and shear strain, and pure compaction bands (PCBs) that have experienced no shearing. PCBs display a wavy or crooked geometry with vertically dipping bands ~1 mm thick. Conversely, SECBs include planar bands up to 1 cm thick with moderate dips defining conjugate geometries. The Buckskin Gulch field site was surveyed, and compaction bands systematically mapped in a sub-area representative of the heaviest deformation. Geologic and structural map units include dune boundaries within the Navajo Sandstone, areas of soft-sediment deformation, and PCBs and SECBs. Mapping shows that SECBs have outcrop characteristics consistent with those reported in previous studies, and are found with varying degrees of deformation in almost all dune units. However, the mapping and compass measurements also reveal a previously unrecognized bimodal pattern of PBC orientation with bands occurring in strands of up to four individual PCBs. One set of orientations only includes single-strand PCBs, whereas the other set is composed of multi-strand PCBs. Both sets of PCBs have nearly vertical dips but their strikes clearly differ from another by up to 25°. Further, PCBs and SECBs show distinct patterns in areas of soft-sediment deformation. Although individual PCB orientations are consistent with the overall trend of PCBs in the area, SECB orientations are chaotic, their growth was clearly affected by the soft-sediment deformation. These field observations are inconsistent with the current understanding of pure compaction band mechanics and so indicate that their growth is more complex than previously thought.

  17. Deep SiO2 etching with Al and AlN masks for MEMS devices

    NASA Astrophysics Data System (ADS)

    Bliznetsov, Vladimir; Mao Lin, Hua; Zhang, Yue Jia; Johnson, David

    2015-08-01

    Silicon oxide-based materials such as quartz and silica are widely used in microelectromechanical systems (MEMS). One way to enhance the capability of their deep plasma etching is to increase selectivity by the use of hard masks. Although this approach was studied previously, information on the use of hard masks for the etching of silicon-oxide based materials on 200 mm substrates is scarce. We present the results of etching process development for amorphous silicon oxide using Al and AlN masks with a view of the application of the results for the etching of silica and quartz. Three gas chemistries (C4F8/O2, CF4 and SF6) and their mixtures were compared in an industrial reactive ion etch (RIE) chamber with two plasma sources. It was established that pure SF6 is the best etchant and AlN is a better mask than Al for providing higher selectivity and a sidewall angle close to vertical. A range of etching parameters for micromasking-free etching was established and etched structures of up to a 4 : 1 aspect ratio were created in 21 μm-thick oxide using the process with an etch rate of 0.32-0.36 μm min-1 and a selectivity to AlN mask of (38-49) : 1.

  18. Revisiting the Al/Al2O3 Interface: Coherent Interfaces and Misfit Accommodation

    PubMed Central

    Pilania, Ghanshyam; Thijsse, Barend J.; Hoagland, Richard G.; Lazić, Ivan; Valone, Steven M.; Liu, Xiang-Yang

    2014-01-01

    We study the coherent and semi-coherent Al/α-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. For the latter case, our analysis reveals an interface dislocation structure with a network of three sets of parallel dislocations, each with pure-edge character, giving rise to a pattern of coherent and stacking-fault-like regions at the interface. Structural relaxation at elevated temperatures leads to a further change of the dislocation pattern, which can be understood in terms of a competition between the stacking fault energy and the dislocation interaction energy at the interface. Our results are expected to serve as an input for the subsequent dislocation dynamics models to understand and predict the macroscopic mechanical behavior of Al/α-Al2O3 composite heterostructures. PMID:24670940

  19. Revisiting the Al/Al2O3 Interface: Coherent Interfaces and Misfit Accommodation

    DOE PAGES

    Pilania, Ghanshyam; Thijsse, Barend J.; Hoagland, Richard G.; Lazić, Ivan; Valone, Steven M.; Liu, Xiang-Yang

    2014-03-27

    We report the coherent and semi-coherent Al/α-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. For the latter case, our analysis reveals an interface dislocation structure with a network of three sets of parallel dislocations, each with pure-edge character, giving rise to a pattern of coherent and stacking-fault-like regions at the interface.more » Structural relaxation at elevated temperatures leads to a further change of the dislocation pattern, which can be understood in terms of a competition between the stacking fault energy and the dislocation interaction energy at the interface. In conclusion, our results are expected to serve as an input for the subsequent dislocation dynamics models to understand and predict the macroscopic mechanical behavior of Al/α-Al2O3 composite heterostructures.« less

  20. The Shock Hugoniot of the Intermetallic Compound Ni3Al

    SciTech Connect

    Knapp, I.; Millett, J. C. F.; Meziere, Y. J. E.; Gray, G. T. III; Bourne, N. K.

    2006-07-28

    The behaviour of the intermetallic compound, Ni3Al under shock loading conditions has been measured. The Hugoniot Elastic Limit occurs at ca. 530 MPa, which converts to a 1-D yield stress of 273 MPa, in agreement with quasi-static data. In contrast, the ductility at shock-induced strain-rates appears much reduced when compared to lower strain-rates. The Hugoniot in terms of shock velocity and particle velocity suggests that Ni3Al is more compressible than pure nickel. This is in agreement with the greater stiffnesses in nickel, measured using ultrasonic techniques.

  1. Interfacial Reaction during Friction Stir Welding of Al and Cu

    NASA Astrophysics Data System (ADS)

    Genevois, C.; Girard, M.; Huneau, B.; Sauvage, X.; Racineux, G.

    2011-08-01

    Commercially pure copper was joined to a 1050 aluminum alloy by friction stir welding. A specific configuration where the tool pin was fully located in the aluminum plate was chosen. In such a situation, there is no mechanical mixing between the two materials, but frictional heating gives rise to a significant thermally activated interdiffusion at the copper/aluminum interface. This gives rise to the formation of defect-free joints where the bonding is achieved by a very thin intermetallic layer at the Cu/Al interface. Nanoscaled grains within this bonding layer were characterized using transmission electron microscopy (TEM). Two phases were identified, namely, Al2Cu and Al4Cu9 phases. The nucleation and growth of these two phases are discussed and compared to the standard reactive interdiffusion reactions between Cu and Al.

  2. Optical and structural properties of Al-ZnO nanocomposites.

    PubMed

    Lee, Geon Joon; Deshpande, Nishad Gopal; Lee, Young Pak; Cheong, Hyeonsik; Swami, Narasimha; Bhat, Jeddu Sadashiva

    2014-05-01

    The optical and structural properties of aluminium-doped zinc oxide (AZO) films were investigated by photoluminescence (PL) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy. Pure zinc oxide (ZnO) and AZO composite films were deposited using vacuum evaporation method. The films exhibited different morphologies and crystallinity depending on the Al-doping. The SEM micrographs showed that a granular and compact structure could be seen for the ZnO film, while a nanoleaf structure with relatively porous nature was observed for the AZO composite film. The XRD patterns indicated that the crystalline growth orientation would be significantly affected by addition of Al. Compared with pure ZnO, the XRD peak intensity of the AZO composite was stronger and the line-width was narrower. Two-probe resistivity measurements showed that the AZO composites could be used as transparent conducting materials. The PL spectra revealed that the PL intensities of the AZO composites were stronger than that of the pure ZnO. The PL enhancement might be ascribed to the surface plasmon resonance of metal nanoclusters within the composite. Another possible reason of the PL enhancement would be the metal-induced crystallization caused by doping Al to ZnO matrix.

  3. [Environmental factors in ALS].

    PubMed

    Juntas-Morales, Raul; Pageot, Nicolas; Corcia, Philippe; Camu, William

    2014-05-01

    ALS is likely to be a disorder of multifactorial origin. Among all the factors that may increase the risk of ALS, environmental ones are being studied for many years, but in the recent years, several advances have pointed to a new interest in their potential involvement in the disease process, especially for the cyanotoxin BMAA. Food containing BMAA has been found on Guam, a well-known focus of ALS/parkinsonism/dementia and high levels of BMAA have been identified into the brain of these patients. The BMAA cyanotoxin is potentially ubiquitous and have also been found into the food of patients who died from ALS both in Europe and USA. BMAA can be wrongly integrated into the protein structure during mRNA traduction, competing with serine. This may induce abnormal protein folding and a subsequent cell death. Heavy metals, such as lead or mercury may be directly toxic for neuronal cells. Several works have suggested an increased risk of ALS in individuals chronically exposed to these metals. Exposure to pesticides has been suggested to be linked to an increased risk of developing ALS. The mechanism of their toxicity is likely to be mediated by paraoxonases. These proteins are in charge of detoxifying the organism from toxins, and particularly organophosphates. To date, there are insufficient scientific data to suggest that exposure to electromagnetic fields may increase the risk of having ALS. We are particularly missing longitudinal cohorts to demonstrate that risk.

  4. Pressure-induced structural phase transition in AlN:Mg and AlN:Co nanowires

    NASA Astrophysics Data System (ADS)

    Xu, Yongsheng; Zhu, Hongyang; Ma, Chunli; Zhu, Pinwen; Cong, Ridong; Wu, Xiaoxin; Gao, Wei; Cui, Qiliang

    2013-06-01

    High-pressure behaviors of AlN:Mg and AlN:Co nanowires have been investigated by in situ angle dispersive synchrotron X-ray diffraction up to 41.5 GPa and 38.2 GPa, respectively. Their corresponding pressure-induced wurtzite-to-rocksalt phase transitions start at 17.7 GPa and 15.0 GPa and complete at 33.2 GPa and 31.0 GPa, respectively. The phase-transition routes are not affected by the doped ions, while the phase transition pressures are lower than that of pure AlN nanowires. The distinct high-pressure behaviors are ascribed to the doped ions, which reduce the formation energy of cation vacancies and induce Al vacancies defects together with substitution defects, resulting in lattice distortion and affecting structural stability and phase transition pressure.

  5. Structural properties of Al and TiAl3 metallic glasses — An embedded atom method study

    NASA Astrophysics Data System (ADS)

    Tahiri, M.; Trady, S.; Hasnaoui, A.; Mazroui, M.; Saadouni, K.; Sbiaai, K.

    2016-06-01

    In this paper, we investigated the structural properties of metallic glasses (MGs). We emphasized our study on monatomic Al and binary TiAl3 systems. The calculations are performed by using the molecular dynamics (MD) simulation based on semi-empirical many-body potentials derived from the embedded atom method. The structure is analyzed using the radial distribution function (RDF), the common neighbor analysis (CNA) and the coordination numbers (CNs). Our results demonstrated that it is possible to form MGs in both systems upon fast cooling from the liquid state. This is confirmed by the fact that the system energy and/or volume during the cooling stage decrease continuously with a slight change and by atomic scale analysis using the RDF, CNA and CN analyzing techniques. Furthermore, this specific study shows that under the same conditions, the icosahedral structures appeared in TiAl3 are more abundant than in pure Al. Implications of these findings are discussed.

  6. Abrupt Schottky Junctions in Al/Ge Nanowire Heterostructures

    PubMed Central

    2015-01-01

    In this Letter we report on the exploration of axial metal/semiconductor (Al/Ge) nanowire heterostructures with abrupt interfaces. The formation process is enabled by a thermal induced exchange reaction between the vapor–liquid–solid grown Ge nanowire and Al contact pads due to the substantially different diffusion behavior of Ge in Al and vice versa. Temperature-dependent I–V measurements revealed the metallic properties of the crystalline Al nanowire segments with a maximum current carrying capacity of about 0.8 MA/cm2. Transmission electron microscopy (TEM) characterization has confirmed both the composition and crystalline nature of the pure Al nanowire segments. A very sharp interface between the ⟨111⟩ oriented Ge nanowire and the reacted Al part was observed with a Schottky barrier height of 361 meV. To demonstrate the potential of this approach, a monolithic Al/Ge/Al heterostructure was used to fabricate a novel impact ionization device. PMID:26052733

  7. Amyotrophic Lateral Sclerosis (ALS)

    MedlinePlus

    ... Pictures of ALS Mutant Proteins Support Two Major Theories About How the Disease is Caused May 2003 ... All NINDS-prepared information is in the public domain and may be freely copied. Credit to the ...

  8. Genetic Testing for ALS

    MedlinePlus

    ... Involved Donate Familial Amyotrophic Lateral Sclerosis (FALS) and Genetic Testing By Deborah Hartzfeld, MS, CGC, Certified Genetic ... guarantee a person will develop symptoms of ALS. Genetic Counseling If there is more than one person ...

  9. All About ALS

    MedlinePlus

    ... External link, please review our exit disclaimer . Subscribe All About ALS Understanding a Devastating Disorder In the ... a coffee pot, or button a shirt. Eventually, all muscles under voluntary control are affected, and people ...

  10. What Is ALS?

    MedlinePlus

    ... scarring or hardening ("sclerosis") in the region. Motor neurons reach from the brain to the spinal cord ... the body. The progressive degeneration of the motor neurons in ALS eventually leads to their demise. When ...

  11. Shear-Limited Diffusion of Test Particles in Pure Ion Plasmas.

    NASA Astrophysics Data System (ADS)

    Anderegg, F.; Driscoll, C. F.; Dubin, D. H. E.

    2001-10-01

    Measurements of test-particle diffusion in pure ion plasmas show 2D enhancements over the 3D rates, limited by shear in the plasma rotation ωE (r). The diffusion is due to ``long-range'' ion-ion collisions in the quiescent, steady-state Mg^+ plasma. For short plasma length Lp and low shear ω_E^' ≡ partial ωE / partial r, thermal ions bounce axially many times before shear separates them in θ, so the ions may move in (r, θ ) as bounce averaged ``rods'' of charge (i.e. 2D point vortices). Experimentally, we vary the number of bounces over the range 0.2 <= Nb ≡ ( barv / 2 Lp ) / r ω_E^' <= 10,000. For long plasmas with Nb <= 1, we observe diffusion in quantitative agreement with the 3D theory of long-range E × B drift collisions.(F. Anderegg et al.), Phys. Rev. Lett. 78, 2128 (1997). For shorter plasmas or lower shear, with Nb > 1, we measure diffusion rates enhanced by approximately N_b. For exceedingly small shear, i.e. Nb >= 1000, we observe diffusion rates consistent with the Taylor-McNamara estimates for a shear-free plasma. Overall, the data shows fair agreement with Dubin's new theory of 2D diffusion in shear.(D.H.E. Dubin and D.Z. Jin, Phys. Lett. A 284), 112-117 (2001).

  12. 4-Mercaptopyridine adsorbed on pure palladium island films: A combined SERS and DFT investigation

    NASA Astrophysics Data System (ADS)

    Guo, Hao; Ding, Li; Zhang, Tianjie; Mo, Yujun

    2013-03-01

    Surface-enhanced Raman scattering (SERS) can provide vibrational information with molecular specificity and potential single-molecule sensitivity. SERS studies on pure transition metals, however, remain challenging due to the weak SERS activity of transition metals compared to coinage metals. Here we fabricated alumina-supported Pd island films by depositing laser-ablated Pd colloids onto an Al substrate. Robust SERS signal employing 4-mercaptopyridine (4-Mpy) as a probe was registered from the as-prepared films. The adsorption information of 4-Mpy molecules such as orientation and coordinating site was discussed in detail based on SERS data. It was inferred that 4-Mpy adsorbs via its sulfur atom to Pd surface with a tilted binding configuration. The Raman wavenumber and intensity of an adsorption model including one 4-Mpy and Pd atom were computed using density functional theory (DFT) at the Beck's three-parameter Lee-Yang-Parr (B3LYP) level with the LANL2DZ basis set. The simulated Raman spectrum was in good agreement with the experimental one except for the relative intensity. The current investigation could be helpful to gain a comprehensive understanding of SERS.

  13. Synthesis and evaluation of ultra-pure rare-earth-coped glass for laser refrigeration

    SciTech Connect

    Patterson, Wendy M; Hehlen, Markus P; Epstein, Richard I; Sheik-bahae, Mansoor

    2009-01-01

    Significant progress has been made in synthesizing and characterizing ultra-pure, rare-earth doped ZIBLAN (ZrF{sub 4}-InF{sub 3}BaF{sub 2}-LaF{sub 3}-AlF{sub 3}-NaF) glass capable of laser refrigeration. The glass was produced from fluorides which were purified and subsequently treated with hydrofluoric gas at elevated temperatures to remove impurities before glass formation. Several Yb3 +-doped samples were studied with degrees of purity and composition with successive iterations producing an improved material. We have developed a non-invasive, spectroscopic technique, two band differential luminescence thermometry (TBDLT), to evaluate the intrinsic quality of the ytterbium doped ZIBLAN used for laser cooling experiments. TBDLT measures local temperature changes within an illuminated volume resulting solely from changes in the relative thermal population of the excited state levels. This TBDLT technique utilizes two commercially available band pass filters to select and integrate the 'difference regions' of interest in the luminescence spectra. The goal is to determine the minimum temperature to which the ytterbium sample can cool on the local scale, unphased by surface heating. This temperature where heating and cooling are exactly balanced is the zero crossing temperature (ZCT) and can be used as a measure for the presence of impurities and the overall quality of the laser cooling material. Overall, favorable results were obtained from 1 % Yb3+-doped glass, indicating our glasses are desirable for laser refrigeration.

  14. Purely electronic mechanism of electrolyte gating of indium tin oxide thin films

    PubMed Central

    Leng, X.; Bollinger, A. T.; Božović, I.

    2016-01-01

    Epitaxial indium tin oxide films have been grown on both LaAlO3 and yttria-stabilized zirconia substrates using RF magnetron sputtering. Electrolyte gating causes a large change in the film resistance that occurs immediately after the gate voltage is applied, and shows no hysteresis during the charging/discharging processes. When two devices are patterned next to one another and the first one gated through an electrolyte, the second one shows no changes in conductance, in contrast to what happens in materials (like tungsten oxide) susceptible to ionic electromigration and intercalation. These findings indicate that electrolyte gating in indium tin oxide triggers a pure electronic process (electron depletion or accumulation, depending on the polarity of the gate voltage), with no electrochemical reactions involved. Electron accumulation occurs in a very thin layer near the film surface, which becomes highly conductive. These results contribute to our understanding of the electrolyte gating mechanism in complex oxides and may be relevant for applications of electric double layer transistor devices. PMID:27506371

  15. Electron transport in pure and substituted iron oxyhydroxides by small-polaron migration

    SciTech Connect

    Alexandrov, Vitali Y.; Rosso, Kevin M.

    2014-08-12

    Iron oxyhydroxides (FeOOH) are common crystalline forms of iron that play a critical role in technology and the natural environment via a variety of important reduction-oxidation reactions, including electrical semiconduction as an aspect. However, a basic understanding of the electron transport properties of these systems is still lacking. We examine the electron mobility in goethite (α-FeOOH), akaganéite (β-FeOOH), and lepidocrocite (γ -FeOOH) polymorphs by means of density functional theory based (DFT+U) calculations.We show that room temperature charge transport should be dominated by the small-polaron hopping type, and that the attendant mobility should be highest for pure goethite and akaganéite. Hopping pathways through the various lattices are discussed in terms of individual electron exchange steps and rates for each. Given the usual occurrence of compositional impurities in natural iron oxyhydroxides, we also investigate the effect of common stoichiometric defects on the electron hopping activation energies such as Al and Cr substitutional cations in goethite, and Cl anions in the channels of akaganéite.

  16. Electron transport in pure and substituted iron oxyhydroxides by small-polaron migration

    SciTech Connect

    Alexandrov, Vitaly Rosso, Kevin M.

    2014-06-21

    Iron oxyhydroxides (FeOOH) are common crystalline forms of iron that play a critical role in technology and the natural environment via a variety of important reduction-oxidation reactions, including electrical semiconduction as an aspect. However, a basic understanding of the electron transport properties of these systems is still lacking. We examine the electron mobility in goethite (α-FeOOH), akaganéite (β-FeOOH), and lepidocrocite (γ-FeOOH) polymorphs by means of density functional theory based (DFT+U) calculations. We show that room temperature charge transport should be dominated by the small-polaron hopping type, and that the attendant mobility should be highest for pure goethite and akaganéite. Hopping pathways through the various lattices are discussed in terms of individual electron exchange steps and rates for each. Given the usual occurrence of compositional impurities in natural iron oxyhydroxides, we also investigate the effect of common stoichiometric defects on the electron hopping activation energies such as Al and Cr substitutional cations in goethite, and Cl anions in the channels of akaganéite.

  17. Purely electronic mechanism of electrolyte gating of indium tin oxide thin films

    NASA Astrophysics Data System (ADS)

    Leng, X.; Bollinger, A. T.; Božović, I.

    2016-08-01

    Epitaxial indium tin oxide films have been grown on both LaAlO3 and yttria-stabilized zirconia substrates using RF magnetron sputtering. Electrolyte gating causes a large change in the film resistance that occurs immediately after the gate voltage is applied, and shows no hysteresis during the charging/discharging processes. When two devices are patterned next to one another and the first one gated through an electrolyte, the second one shows no changes in conductance, in contrast to what happens in materials (like tungsten oxide) susceptible to ionic electromigration and intercalation. These findings indicate that electrolyte gating in indium tin oxide triggers a pure electronic process (electron depletion or accumulation, depending on the polarity of the gate voltage), with no electrochemical reactions involved. Electron accumulation occurs in a very thin layer near the film surface, which becomes highly conductive. These results contribute to our understanding of the electrolyte gating mechanism in complex oxides and may be relevant for applications of electric double layer transistor devices.

  18. Purely electronic mechanism of electrolyte gating of indium tin oxide thin films.

    PubMed

    Leng, X; Bollinger, A T; Božović, I

    2016-01-01

    Epitaxial indium tin oxide films have been grown on both LaAlO3 and yttria-stabilized zirconia substrates using RF magnetron sputtering. Electrolyte gating causes a large change in the film resistance that occurs immediately after the gate voltage is applied, and shows no hysteresis during the charging/discharging processes. When two devices are patterned next to one another and the first one gated through an electrolyte, the second one shows no changes in conductance, in contrast to what happens in materials (like tungsten oxide) susceptible to ionic electromigration and intercalation. These findings indicate that electrolyte gating in indium tin oxide triggers a pure electronic process (electron depletion or accumulation, depending on the polarity of the gate voltage), with no electrochemical reactions involved. Electron accumulation occurs in a very thin layer near the film surface, which becomes highly conductive. These results contribute to our understanding of the electrolyte gating mechanism in complex oxides and may be relevant for applications of electric double layer transistor devices. PMID:27506371

  19. Phase Separation Mediated Devitrification of Al88Y7Fe5 Glasses

    SciTech Connect

    Sahu, K. K.; Mauro, N. A.; Longstreth-Spoor, Lydia; Saha, D.; Miller, Michael K; Nussinova, Z; Kelton, K. F.

    2010-01-01

    The mechanisms responsible for the nanoscale devitrification of Al-based metallic glasses are unclear. A particularly well-studied case is Al{sub 88}Y{sub 7}Fe{sub 5}, where non-isothermal differential scanning calorimetry (DSC) measurements show an exothermic peak that is consistent with glass devitrification to {alpha}-Al, but with no glass transition. Additionally, isothermal DSC studies show a monotonic decrease in enthalpy release with annealing, a feature generally taken to indicate grain coarsening. The results of coordinated DSC, bright field transmission electron microscopy, in situ electrical resistivity and atom probe tomography (APT) studies of Al{sub 88}Y{sub 7}Fe{sub 5} support a nucleation/growth-based crystallization process. The APT data indicate the presence of sub-nanometer pure Al zones and coarser scale (separation distance -74-126nm) Al-rich regions in the glass. The pure Al zones dispersed in the Al-rich regions appear to catalyze {alpha}-Al nucleation, explaining the high nucleation rates. The solute-rich regions between the Al-rich regions inhibit long-range diffusion, explaining the low growth rates.

  20. Raman study of the Verwey transition in magnetite at high-pressure and low-temperature: Effect of Al doping

    NASA Astrophysics Data System (ADS)

    Gasparov, L.; Shirshikova, Z.; Pekarek, T. M.; Blackburn, J.; Struzhkin, V.; Gavriliuk, A.; Rueckamp, R.; Berger, H.

    2012-08-01

    We employed Raman spectroscopy to investigate how the hydrostatic pressure affects the temperature of the Verwey transition in pure (Fe3O4) and Al-doped (Fe2.8Al0.2O4) magnetite. In both samples, pressure suppresses the transition. The Al-doped sample displays no transition above 8 GPa. We do not observe such discontinuity in a pure magnetite, which suggests that the discontinuity is doping driven. Our Clausius-Clapeyron formula based analysis of the pressure-transition temperature dependence is in excellent agreement with our data in pure magnetite. The Al doping leads to a smaller entropy change and larger volume expansion consistent with partial charge ordering at the transition.

  1. Extensive genetics of ALS

    PubMed Central

    Calvo, Andrea; Mazzini, Letizia; Cantello, Roberto; Mora, Gabriele; Moglia, Cristina; Corrado, Lucia; D'Alfonso, Sandra; Majounie, Elisa; Renton, Alan; Pisano, Fabrizio; Ossola, Irene; Brunetti, Maura; Traynor, Bryan J.; Restagno, Gabriella

    2012-01-01

    Objective: To assess the frequency and clinical characteristics of patients with mutations of major amyotrophic lateral sclerosis (ALS) genes in a prospectively ascertained, population-based epidemiologic series of cases. Methods: The study population includes all ALS cases diagnosed in Piemonte, Italy, from January 2007 to June 2011. Mutations of SOD1, TARDBP, ANG, FUS, OPTN, and C9ORF72 have been assessed. Results: Out of the 475 patients included in the study, 51 (10.7%) carried a mutation of an ALS-related gene (C9ORF72, 32; SOD1, 10; TARDBP, 7; FUS, 1; OPTN, 1; ANG, none). A positive family history for ALS or frontotemporal dementia (FTD) was found in 46 (9.7%) patients. Thirty-one (67.4%) of the 46 familial cases and 20 (4.7%) of the 429 sporadic cases had a genetic mutation. According to logistic regression modeling, besides a positive family history for ALS or FTD, the chance to carry a genetic mutation was related to the presence of comorbid FTD (odds ratio 3.5; p = 0.001), and age at onset ≤54 years (odds ratio 1.79; p = 0.012). Conclusions: We have found that ∼11% of patients with ALS carry a genetic mutation, with C9ORF72 being the commonest genetic alteration. Comorbid FTD or a young age at onset are strong indicators of a possible genetic origin of the disease. PMID:23100398

  2. Modulating TiO2 photocatalyst by Al doping: Density functional theory approach

    NASA Astrophysics Data System (ADS)

    Zhao, Ya Fei; Li, Can; Lu, Song; Gong, Yin Yan; Niu, Leng Yuan; Liu, Xin Juan

    2016-06-01

    In this work, systematic study of the thermal stability, crystal structure and electronic properties of Al doped TiO2 were studied by the first principles calculations. The results showed that Al atoms preferentially occupying the interstitial site under Ti-rich condition, but substituting the Ti atom under O-rich condition. In contrast to pure TiO2, the values of VBM and CBM are reduced for Al substituting Ti doped mode, but increased for Al interstitial atom doped mode. Thus, we can modulate the preparation condition and dosage concentration for preparing the optimal photocatalyst.

  3. MRI appearances of pure epithelial papillary serous borderline ovarian tumours.

    PubMed

    Naqvi, J; Nagaraju, E; Ahmad, S

    2015-04-01

    Borderline epithelial ovarian tumours (BOT) represent 15-20% of all non-benign ovarian epithelial neoplasms. Compared to malignant ovarian tumours, they usually present at a younger age and carry a far superior prognosis. Fertility-conserving surgery is an important treatment option for patients with BOT. Ultrasound and CT are both widely available and play roles in the initial investigation and staging of BOT, respectively. However, lack of soft-tissue contrast limits their ability to characterize BOT. MRI can facilitate recognition of pure epithelial serous BOT (SBOT), including the cystic papillary and surface papillary subtypes. An abundance of hyperintense papillary projections with low signal internal branching and ovarian stroma preservation with a hypointense ovarian capsular margin on T2-weighted imaging are features strongly suggestive of SBOT. In this review we will discuss the general morphological features of SBOT, the benefits and drawbacks of ultrasound and CT in the initial work-up, and the principal MRI features enabling recognition of surface papillary and cystic papillary SBOT.

  4. Optical characterization of phase transitions in pure polymers and blends

    NASA Astrophysics Data System (ADS)

    Mannella, Gianluca A.; Brucato, Valerio; La Carrubba, Vincenzo

    2015-12-01

    To study the optical properties of polymeric samples, an experimental apparatus was designed on purpose and set up. The sample is a thin film enclosed between two glass slides and a PTFE frame, with a very thin thermocouple placed on sample for direct temperature measurement. This sample holder was placed between two aluminum slabs, equipped with a narrow slit for optical measurements and with electrical resistances for temperature control. Sample was enlightened by a laser diode, whereas transmitted light was detected with a photodiode. Measurements were carried out on polyethylene-terephtalate (PET) and two different polyamides, tested as pure polymers and blends. The thermal history imposed to the sample consisted in a rapid heating from ambient temperature to a certain temperature below the melting point, a stabilization period, and then a heating at constant rate. After a second stabilization period, the sample was cooled. The data obtained were compared with DSC measurements performed with the same thermal history. In correspondence with transitions detected via DSC (e.g. melting, crystallization and cold crystallization), the optical signal showed a steep variation. In particular, crystallization resulted in a rapid decrease of transmitted light, whereas melting gave up an increase of light transmitted by the sample. Further variations in transmitted light were recorded for blends, after melting: those results may be related to other phase transitions, e.g. liquid-liquid phase separation. All things considered, the apparatus can be used to get reliable data on phase transitions in polymeric systems.

  5. Hippocampal volume and shape in pure subcortical vascular dementia.

    PubMed

    Kim, Geon Ha; Lee, Jae Hong; Seo, Sang Won; Kim, Jeong Hun; Seong, Joon-Kyung; Ye, Byoung Seok; Cho, Hanna; Noh, Young; Kim, Hee Jin; Yoon, Cindy W; Oh, Seung Jun; Kim, Jae Seung; Choe, Yearn Seong; Lee, Kyung Han; Kim, Sung Tae; Hwang, Jung Won; Jeong, Jee Hyang; Na, Duk L

    2015-01-01

    The purposes of the present study were to explore whether hippocampal atrophy exists in pure subcortical vascular dementia (SVaD) as defined by negative (11)C-Pittsburg compound-B (PiB(-)) positron emission tomography and to compare hippocampal volume and shape between PiB(-) SVaD and PiB positive (PiB(+)) Alzheimer's disease (AD) dementia. Hippocampal volume and shape were compared among 40 patients with PiB(-) SVaD, 34 with PiB(+) AD, and 21 elderly with normal cognitive function (NC). The normalized hippocampal volume of PiB(-) SVaD was significantly smaller than NC but larger than that of PiB(+) AD (NC > PiB(-) SVaD > PiB(+) AD). Both PiB(-) SVaD and PiB(+) AD patients had deflated shape changes in the cornus ammonis (CA) 1 and subiculum compared with NC. However, direct comparison between PiB(-) SVaD and PiB(+) AD demonstrated more inward deformity in the subiculum of the left hippocampus in PiB(+) AD. PiB(-) SVaD patients did have smaller hippocampal volumes and inward shape change on CA 1 and subiculum compared with NC, suggesting that cumulative ischemia without amyloid pathology could lead to hippocampal atrophy and shape changes. PMID:25444608

  6. Pure Lymphoepithelioma-Like Carcinoma Originating from the Urinary Bladder

    PubMed Central

    Nagai, Takashi; Naiki, Taku; Kawai, Noriyasu; Iida, Keitaro; Etani, Toshiki; Ando, Ryosuke; Hamamoto, Shuzo; Sugiyama, Yosuke; Okada, Atsushi; Mizuno, Kentaro; Umemoto, Yukihiro; Yasui, Takahiro

    2016-01-01

    Lymphoepithelioma-like carcinoma of the urinary bladder (LELCB) is a rare variant of infiltrating urothelial carcinoma. We report a case of LELCB in a 43-year-old man. Ultrasonography and cystoscopy revealed two bladder tumors, one on the left side of the trigone and the other on the right side of the trigone. Transurethral resection of the bladder tumors was performed and pathological analysis revealed undifferentiated carcinoma. We therefore performed radical cystectomy and urinary diversion. Immunohistochemically the tumor cells were positive for cytokeratin, but negative for Epstein-Barr virus-encoded small RNA in situ hybridization as found for previous cases of LELCB. The final pathological diagnosis was a lymphoepithelioma-like variant of urothelial carcinoma with perivesical soft tissue invasion. For adjuvant systemic chemotherapy, three courses of cisplatin were administered. The patient subsequently became free of cancer 72 months postoperatively. Based on the literature, pure or predominant LELCB types show favorable prognoses due to their sensitivity to chemotherapy or radiotherapy. An analysis of the apparent diffusion coefficient (ADC) values of bladder tumors examined in our institution revealed that the ADC value measured for this LELCB was relatively low compared to conventional urothelial carcinomas. This suggests that measuring the ADC value of a lymphoepithelioma-like carcinoma prior to operation may be helpful in predicting LELCB. PMID:27099604

  7. Water and Air Measures That Make 'PureSense'

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Each day, we read about mounting global concerns regarding the ability to sustain supplies of clean water and to reduce air contamination. With water and air serving as life s most vital elements, it is important to know when these environmental necessities may be contaminated, in order to eliminate exposure immediately. The ability to respond requires an understanding of the conditions impacting safety and quality, from source to tap for water, and from outdoor to indoor environments for air. Unfortunately, the "time-to-know" is not immediate with many current technologies, which is a major problem, given the greater likelihood of risky situations in today s world. Accelerating alert and response times requires new tools, methods, and technologies. New solutions are needed to engage in more rapid detection, analysis, and response. This is the focus of a company called PureSense Environmental, Inc., which evolved out of a unique relationship with NASA. The need for real-time management and operations over the quality of water and air, and the urgency to provide new solutions, were reinforced by the events of September 11, 2001. This, and subsequent events, exposed many of the vulnerabilities facing the multiple agencies tasked with working in tandem to protect communities from harmful disaster. Much has been done since September 11 to accelerate responses to environmental contamination. Partnerships were forged across the public and private sectors to explore, test, and use new tools. Methods and technologies were adopted to move more astutely from proof-of-concept to working solutions.

  8. Temperature dependent deformation mechanisms in pure amorphous silicon

    SciTech Connect

    Kiran, M. S. R. N. Haberl, B.; Williams, J. S.; Bradby, J. E.

    2014-03-21

    High temperature nanoindentation has been performed on pure ion-implanted amorphous silicon (unrelaxed a-Si) and structurally relaxed a-Si to investigate the temperature dependence of mechanical deformation, including pressure-induced phase transformations. Along with the indentation load-depth curves, ex situ measurements such as Raman micro-spectroscopy and cross-sectional transmission electron microscopy analysis on the residual indents reveal the mode of deformation under the indenter. While unrelaxed a-Si deforms entirely via plastic flow up to 200 °C, a clear transition in the mode of deformation is observed in relaxed a-Si with increasing temperature. Up to 100 °C, pressure-induced phase transformation and the observation of either crystalline (r8/bc8) end phases or pressure-induced a-Si occurs in relaxed a-Si. However, with further increase of temperature, plastic flow rather than phase transformation is the dominant mode of deformation. It is believed that the elevated temperature and pressure together induce bond softening and “defect” formation in structurally relaxed a-Si, leading to the inhibition of phase transformation due to pressure-releasing plastic flow under the indenter.

  9. Optical characterization of phase transitions in pure polymers and blends

    SciTech Connect

    Mannella, Gianluca A.; Brucato, Valerio; La Carrubba, Vincenzo

    2015-12-17

    To study the optical properties of polymeric samples, an experimental apparatus was designed on purpose and set up. The sample is a thin film enclosed between two glass slides and a PTFE frame, with a very thin thermocouple placed on sample for direct temperature measurement. This sample holder was placed between two aluminum slabs, equipped with a narrow slit for optical measurements and with electrical resistances for temperature control. Sample was enlightened by a laser diode, whereas transmitted light was detected with a photodiode. Measurements were carried out on polyethylene-terephtalate (PET) and two different polyamides, tested as pure polymers and blends. The thermal history imposed to the sample consisted in a rapid heating from ambient temperature to a certain temperature below the melting point, a stabilization period, and then a heating at constant rate. After a second stabilization period, the sample was cooled. The data obtained were compared with DSC measurements performed with the same thermal history. In correspondence with transitions detected via DSC (e.g. melting, crystallization and cold crystallization), the optical signal showed a steep variation. In particular, crystallization resulted in a rapid decrease of transmitted light, whereas melting gave up an increase of light transmitted by the sample. Further variations in transmitted light were recorded for blends, after melting: those results may be related to other phase transitions, e.g. liquid-liquid phase separation. All things considered, the apparatus can be used to get reliable data on phase transitions in polymeric systems.

  10. [Pure form of primary ovarian choriocarcinoma. Report of a case].

    PubMed

    Trigueros Velázquez, M; Sereno Coló, J A; Villagrán Urive, J

    1995-08-01

    Ovarian choriocarcinoma from the germ cells is a very rare malignant neoplasia. About the pure form, very few cases have been reported in medical literature. Ovarian choriocarcinoma may originate in three modalities. As primary choriocarcinoma associated to ovarian pregnancy, 2. As a metastatic ovarian carcinoma, from other organs, mainly the uterus, 3. As a primary tumour of germ cells with differentiation to trophoblastic structures. The latter grows in girls or in adult woman, generally young, where necessarily pregnancy has to be excluded. A case is presented of a 21 years old woman, treated at Hospital General "Dr. Miguel Silva", Morelia, Mich. single, without sexual life, with an abdomino-pelvic tumor of 24 cm, from the right ovary and adhered to ascending colon. Beta subunity of chorionic gonadotrophin was 200,000 mUI/ml of blood plasma. At laparotomy a right ovarian tumour, with infiltration to ascending colon, was found; this required total hysterectomy with bilateral salpingo-oophorectomy and right hemicolectomy. After surgery the patient received chemotherapy with cisplatin, bleomicin and vinblastine. After the third treatment cycle and at three months, chorionic gonadotropin became negative; and at four years follow up residual tumoural activity is absent. Largest mortality with these tumors appears during early post-operative stage and it is atributed to the tumour itself or to post-operative complications. If the patient survives this stage and with a good chemotherapeutic program, survival and even complete cure, occurs.

  11. Monogamy of quantum correlations in three-qubit pure states

    NASA Astrophysics Data System (ADS)

    Sudha; Devi, A. R. Usha; Rajagopal, A. K.

    2012-01-01

    The limitation on the shareability of quantum entanglement over several parties, the so-called monogamy of entanglement, is an issue that has received considerable attention from the quantum information community over the last decade. A natural question of interest in this connection is whether monogamy of correlations is true for correlations other than entanglement. This issue is examined here by choosing quantum deficit, proposed by A. K. Rajagopal and R. W. Rendell [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.66.022104 66, 022104 (2002)], an operational measure of correlations. In addition to establishing the polygamous nature of the class of three-qubit symmetric pure states characterized by two distinct Majorana spinors (to which the W states belong), those with three distinct Majorana spinors [to which Greenberger-Horne-Zeilinger (GHZ) states belong] are shown to either obey or violate monogamy relations. While the generalized W states can be monogamous or polygamous, the generalized GHZ states exhibit monogamy with respect to quantum deficit. The issue of using monogamy conditions based on quantum deficit to witness the states belonging to stochastic local operations and classical communication (SLOCC) inequivalent classes is discussed in light of these results.

  12. Crystallization Evolution of Cold-Sprayed Pure Ni Coatings

    NASA Astrophysics Data System (ADS)

    Cavaliere, P.; Perrone, A.; Silvello, A.

    2016-08-01

    Cold spraying is a coating technology on the basis of aerodynamics and high-speed impact dynamics. Spray particles (usually 1-50 μm in diameter) are accelerated to high velocity (typically 300-1200 m/s) by a high-speed gas (preheated air, nitrogen, or helium) flow that is generated through a convergent-divergent de Laval type nozzle. The coating forms through the intensive plastic deformation of particles impacting on the substrate at temperatures well below the melting point of the spray material. In the present paper, the main processing parameters affecting the crystallization behavior of pure Ni cold spray deposits on IN718 alloy are described. Various experimental conditions have been analyzed: gas temperature and pressure, nozzle to substrate distance. In particular, the study deals with those conditions leading to a strong grain refinement, with an acceptable level of the deposits mechanical properties. In precise spray conditions, a shift toward amorphous phases has been observed and studied. A systematic analysis of microstructural evolution, performed through TEM observations, as a function of processing parameters is presented.

  13. Chimera states in purely local delay-coupled oscillators

    NASA Astrophysics Data System (ADS)

    Bera, Bidesh K.; Ghosh, Dibakar

    2016-05-01

    We study the existence of chimera states in a network of locally coupled chaotic and limit-cycle oscillators. The necessary condition for chimera state in purely local coupled oscillators is discussed. At first, we numerically observe the existence of chimera or multichimera states in the locally coupled Hindmarsh-Rose neuron model. We find that delay time in the nonlinear local coupling reduces the domain of the coherent island in the parameter space of the synaptic coupling strength and time delay, and thus the coherent region can be completely eliminated once the time delay exceeds a certain threshold. We then consider another form of nonlinearity in the local coupling, and the existence of chimera states is observed in the time-delayed Mackey-Glass system and in a Van der Pol oscillator. We also discuss the effect of time delay in local coupling for the existence of chimera states in Mackey-Glass systems. The nonlinearity present in the coupling function plays a key role in the emergence of chimera or multichimera states. A phase diagram for the chimera state is identified over a wide parameter space.

  14. Dirac Node Lines in Pure Alkali Earth Metals.

    PubMed

    Li, Ronghan; Ma, Hui; Cheng, Xiyue; Wang, Shoulong; Li, Dianzhong; Zhang, Zhengyu; Li, Yiyi; Chen, Xing-Qiu

    2016-08-26

    Beryllium is a simple alkali earth metal, but has been the target of intensive studies for decades because of its unusual electron behavior at surfaces. The puzzling aspects include (i) severe deviations from the description of the nearly free-electron picture, (ii) an anomalously large electron-phonon coupling effect, and (iii) giant Friedel oscillations. The underlying origins for such anomalous surface electron behavior have been under active debate, but with no consensus. Here, by means of first-principles calculations, we discover that this pure metal system, surprisingly, harbors the Dirac node line (DNL) that in turn helps to rationalize many of the existing puzzles. The DNL is featured by a closed line consisting of linear band crossings, and its induced topological surface band agrees well with previous photoemission spectroscopy observations on the Be (0001) surface. We further reveal that each of the elemental alkali earth metals of Mg, Ca, and Sr also harbors the DNL and speculate that the fascinating topological property of the DNL might naturally exist in other elemental metals as well. PMID:27610865

  15. Generalized gauge transformations: Pure Yang-Mills case

    SciTech Connect

    Gastmans, R.; Wu, T.T. |

    1998-01-01

    Gauge transformations with Dirac point splitting are systematically discussed for the case of a pure Yang-Mills theory. These generalized gauge transformations are based on two ingredients: a fixed four-vector, which defines the point splitting, and a weight function, which gives an average over the amount of point splitting and which provides a cutoff in momentum space in the direction of the point splitting four-vector. From the requirement that the group property must be satisfied, it is found, starting from a simple ansatz, that an infinitesimal generalized gauge transformation takes the form of an infinite series in the coupling constant. Using induction on the order of the coupling constant, it is shown that all higher-order terms indeed exist and that they can be expressed in terms of the lower-order formulas. That there are such generalized gauge transformations suggests the possibility of a Yang-Mills field theory with mitigated divergences. {copyright} {ital 1997} {ital The American Physical Society}

  16. Universality in pure gravity mediation with vector multiplets

    NASA Astrophysics Data System (ADS)

    Evans, Jason L.; Olive, Keith A.

    2014-12-01

    We consider models of pure gravity mediation in which scalar mass universality is imposed at the grand unified scale and gaugino masses are generated through loops. The minimal model requires a very restricted range for tan β ≈2 - 3 and scalar masses (set by the gravitino mass) of order 300 TeV-1.5 PeV in order to obtain a Higgs mass near 126 GeV. Here we augment the minimal model with one or more sets of vector multiplets (either a 10 and 10 ¯ pair or one or more 5 and 5 ¯ pairs). If coupled to the minimal supersymmetric standard model Higgs, these allow for radiative electroweak symmetry breaking over a significantly larger range of tan β ≈2 - 40 and can fit the Higgs mass with much smaller values of the gravitino mass. In these models, the lightest supersymmetric particle is often the bino, and in order to satisfy the relic density constraint, the bino must be nearly degenerate with either the wino or gluino. In the models considered here, bino gluino coannihilations determine the relic density and since the two are nearly degenerate, LHC limits on the gluino mass are greatly relaxed allowing light relatively gravitinos and gluino masses well within the reach of the LHC.

  17. Anomalous preservation of pure methane hydrate at 1 atm

    USGS Publications Warehouse

    Stern, L.A.; Circone, S.; Kirby, S.H.; Durham, W.B.

    2001-01-01

    Direct measurement of decomposition rates of pure, polycrystalline methane hydrate reveals a thermal regime where methane hydrate metastably `preserves' in bulk by as much as 75 K above its nominal equilibrium temperature (193 K at 1 atm). Rapid release of the sample pore pressure at isothermal conditions between 242 and 271 K preserves up to 93% of the hydrate for at least 24 h, reflecting the greatly suppressed rates of dissociation that characterize this regime. Subsequent warming through the H2O ice point then induces rapid and complete dissociation, allowing controlled recovery of the total expected gas yield. This behavior is in marked contrast to that exhibited by methane hydrate at both colder (193-240 K) and warmer (272-290 K) test conditions, where dissociation rates increase monotonically with increasing temperature. Anomalous preservation has potential application for successful retrieval of natural gas hydrate or hydrate-bearing sediments from remote settings, as well as for temporary low-pressure transport and storage of natural gas.

  18. Ecophysiological and Phylogenetic Studies of Nevskia ramosa in Pure Culture

    PubMed Central

    Stürmeyer, Heike; Overmann, Jörg; Babenzien, Hans-Dietrich; Cypionka, Heribert

    1998-01-01

    During the last 100 years, the neuston bacterium Nevskia ramosa has been described several times. This bacterium forms conspicuous rosette-like microcolonies at the air-water interface. In this study, pure cultures of Nevskia ramosa were obtained for the first time, from a bog lake (strain Soe1, DSMZ 11499T) and a freshwater ditch (strain OL1, DSMZ 11500). The isolates showed special adaptations to life in the epineuston. They formed hydrophobic surface films with a dull appearance. N. ramosa is sensitive to UV radiation but revealed a very effective photorepair mechanism. Exposure to light at a wavelength of 350 nm after UV treatment raised the number of surviving cells by several orders of magnitude. The isolates grew with a broad range of organic substrates. Surface films were formed only in the absence of combined nitrogen; however, nitrogenase activity was not detected. It appears that during growth at the air-water interface the cells benefit from trapping ammonia from the air. The G+C content of the DNA was 67.8 and 69.0 mol% for strains Soe1 and OL1, respectively. The slight difference was confirmed by enterobacterial repetitive intergenic consensus PCR. The 16S rRNA sequences revealed 99.2% similarity. Thus, both isolates belong to the same species. The phylogenetic analysis indicated that Nevskia is a member of the gamma-subclass Proteobacteria that has no known close relatives. PMID:9572968

  19. Early stages during plasma nitriding of pure iron

    SciTech Connect

    Palacios, M.D.; Martinez, O.; Oseguera, J.

    1995-12-31

    The sequence of nitride formation during the early stages of plasma nitriding of pure iron was studied by optical microscopy, SEM, TEM and x-ray diffraction. Plasma nitriding at {approximately}490 C in a 25 vol.%H{sub 2} + 75 vol.%N{sub 2} mixture starts with the formation of {gamma}{prime}-Fe{sub 4}N after 40s. Once {gamma}{prime} nucleates, it mainly spreads laterally due to diffusion shortcuts in the discontinuous surface nitride layer. Before {gamma}{prime} is continuous on the surface, {epsilon} nucleates on top of it shortly after 40S. Epsilon is then observed to grow, both inwardly and laterally along with {gamma}{prime}. A compact {gamma}{prime}/{epsilon} bilayer forms on the surface at around 100s. The kinetics of nucleation, growth and compactation of the nitrides observed in the present work was significantly more rapid than in any of the nitriding process reported in the literature, including plasma nitriding. The acceleration of the nitriding kinetics in the early stages of plasma nitriding may be attributed to enhanced diffusion resulting from a high nitrogen flux from the plasma atmosphere. The results presented are consistent with the findings of a companion work on modeling the kinetics of nitride layer growth.

  20. Ion-induced nucleation of pure biogenic particles.

    PubMed

    Kirkby, Jasper; Duplissy, Jonathan; Sengupta, Kamalika; Frege, Carla; Gordon, Hamish; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K; Wagner, Robert; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill; Dias, Antonio; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P; Pringle, Kirsty; Rap, Alexandru; Richards, Nigel A D; Riipinen, Ilona; Rissanen, Matti P; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E; Seinfeld, John H; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander L; Wagner, Andrea C; Wagner, Paul E; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M; Worsnop, Douglas R; Baltensperger, Urs; Kulmala, Markku; Carslaw, Kenneth S; Curtius, Joachim

    2016-05-25

    Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere, and that ions have a relatively minor role. Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded. Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of α-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported by quantum chemical calculations of the cluster binding energies of representative HOMs. Ion-induced nucleation of pure organic particles constitutes a potentially widespread source of aerosol particles in terrestrial environments with low sulfuric acid pollution.

  1. Stress Wave Isolation by Purely Mechanical Topological Phononic Crystals

    PubMed Central

    Chaunsali, Rajesh; Li, Feng; Yang, Jinkyu

    2016-01-01

    We present an active, purely mechanical stress wave isolator that consists of short cylindrical particles arranged in a helical architecture. This phononic structure allows us to change inter-particle stiffness dynamically by controlling the contact angles of the cylinders. We use torsional travelling waves to control the contact angles, thereby imposing a desired spatio-temporal stiffness variation to the phononic crystal along the longitudinal direction. Such torsional excitation is a form of parametric pumping in the system, which results in the breakage of the time-reversal symmetry. We report that, in quasi-static sense, the system shows topologically non-trivial band-gaps. However, in a dynamic regime where the pumping effect is significant, these band-gaps become asymmetric with respect to the frequency and wavenumber domains in the dispersion relationship. By using numerical simulations, we show that such asymmetry has a direct correspondence to the topological invariant, i.e., Chern number, of the system. We propose that this asymmetry, accompanied by selective inter-band transition, can be utilized for directional isolation of the stress wave propagating along the phononic crystal. PMID:27477236

  2. Pure and aerated water entry of a flat plate

    NASA Astrophysics Data System (ADS)

    Ma, Z. H.; Causon, D. M.; Qian, L.; Mingham, C. G.; Mai, T.; Greaves, D.; Raby, A.

    2016-01-01

    This paper presents an experimental and numerical investigation of the entry of a rigid square flat plate into pure and aerated water. Attention is focused on the measurement and calculation of the slamming loads on the plate. The experimental study was carried out in the ocean basin at Plymouth University's COAST laboratory. The present numerical approach extends a two-dimensional hydro-code to compute three-dimensional hydrodynamic impact problems. The impact loads on the structure computed by the numerical model compare well with laboratory measurements. It is revealed that the impact loading consists of distinctive features including (1) shock loading with a high pressure peak, (2) fluid expansion loading associated with very low sub-atmospheric pressure close to the saturated vapour pressure, and (3) less severe secondary reloading with super-atmospheric pressure. It is also disclosed that aeration introduced into water can effectively reduce local pressures and total forces on the flat plate. The peak impact loading on the plate can be reduced by half or even more with 1.6% aeration in water. At the same time, the lifespan of shock loading is prolonged by aeration, and the variation of impulse is less sensitive to the change of aeration than the peak loading.

  3. Dirac Node Lines in Pure Alkali Earth Metals.

    PubMed

    Li, Ronghan; Ma, Hui; Cheng, Xiyue; Wang, Shoulong; Li, Dianzhong; Zhang, Zhengyu; Li, Yiyi; Chen, Xing-Qiu

    2016-08-26

    Beryllium is a simple alkali earth metal, but has been the target of intensive studies for decades because of its unusual electron behavior at surfaces. The puzzling aspects include (i) severe deviations from the description of the nearly free-electron picture, (ii) an anomalously large electron-phonon coupling effect, and (iii) giant Friedel oscillations. The underlying origins for such anomalous surface electron behavior have been under active debate, but with no consensus. Here, by means of first-principles calculations, we discover that this pure metal system, surprisingly, harbors the Dirac node line (DNL) that in turn helps to rationalize many of the existing puzzles. The DNL is featured by a closed line consisting of linear band crossings, and its induced topological surface band agrees well with previous photoemission spectroscopy observations on the Be (0001) surface. We further reveal that each of the elemental alkali earth metals of Mg, Ca, and Sr also harbors the DNL and speculate that the fascinating topological property of the DNL might naturally exist in other elemental metals as well.

  4. Pure global acalculia following a left subangular lesion.

    PubMed

    Martory, M D; Mayer, E; Pegna, A J; Annoni, J M; Landis, T; Khateb, A

    2003-08-01

    We describe the case of a right-handed patient who presented a severe acalculia in the context of a pure Gerstmann syndrome following a subangular lesion that spared the left inferior parietal lobule (IPL). The patient showed impairments in Arabic and verbal codes, in number production and comprehension, as well as in numerical facts and problem solving. By using the EC301 calculation battery, semantic and syntactic tasks in Arabic and verbal codes, we tested the different hypotheses raised by the cognitive neuropsychological models of acalculia. The patients' difficulties, which were not associated with a general intellectual deterioration, and those affecting number processing as a particular semantic class, were indicative of a "global acalculia". This deficit, which exceeded the anarithmetia usually described in Gerstmann syndrome following left IPL lesion, suggested that the isolation of this area may constitute a sufficient condition for producing such a global acalculia. These results are discussed in terms of a disorder in the manipulation of mental images of spatially related objects. PMID:12925945

  5. Ion-induced nucleation of pure biogenic particles

    NASA Astrophysics Data System (ADS)

    Kirkby, Jasper; Duplissy, Jonathan; Sengupta, Kamalika; Frege, Carla; Gordon, Hamish; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K.; Wagner, Robert; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill; Dias, Antonio; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R.; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P.; Pringle, Kirsty; Rap, Alexandru; Richards, Nigel A. D.; Riipinen, Ilona; Rissanen, Matti P.; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E.; Seinfeld, John H.; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander L.; Wagner, Andrea C.; Wagner, Paul E.; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M.; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M.; Worsnop, Douglas R.; Baltensperger, Urs; Kulmala, Markku; Carslaw, Kenneth S.; Curtius, Joachim

    2016-05-01

    Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere, and that ions have a relatively minor role. Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded. Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of α-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported by quantum chemical calculations of the cluster binding energies of representative HOMs. Ion-induced nucleation of pure organic particles constitutes a potentially widespread source of aerosol particles in terrestrial environments with low sulfuric acid pollution.

  6. Thermal pure quantum states of many-particle systems

    NASA Astrophysics Data System (ADS)

    Hyuga, Masahiko; Sugiura, Sho; Sakai, Kazumitsu; Shimizu, Akira

    2014-09-01

    We generalize the thermal pure quantum (TPQ) formulation of statistical mechanics, in such a way that it is applicable to systems whose Hilbert space is infinite dimensional. Assuming particle systems, we construct the grand-canonical TPQ (gTPQ) state, which is the counterpart of the grand-canonical Gibbs state of the ensemble formulation. A single realization of the gTPQ state gives all quantities of statistical-mechanical interest, with exponentially small probability of error. This formulation not only sheds new light on quantum statistical mechanics but also is useful for practical computations. As an illustration, we apply it to the Hubbard model, on a one-dimensional (1D) chain and on a two-dimensional (2D) triangular lattice. For the 1D chain, our results agree well with the exact solutions over wide ranges of temperature, chemical potential, and the on-site interaction. For the 2D triangular lattice, for which exact results are unknown, we obtain reliable results over a wide range of temperature. We also find that finite-size effects are much smaller in the gTPQ state than in the canonical TPQ state. This also shows that in the ensemble formulation the grand-canonical Gibbs state of a finite-size system simulates an infinite system much better than the canonical Gibbs state.

  7. Theory of Phase Separation and Polarization for Pure Ionic Liquids.

    PubMed

    Gavish, Nir; Yochelis, Arik

    2016-04-01

    Room temperature ionic liquids are attractive to numerous applications and particularly, to renewable energy devices. As solvent free electrolytes, they demonstrate a paramount connection between the material morphology and Coulombic interactions: the electrode/RTIL interface is believed to be a product of both polarization and spatiotemporal bulk properties. Yet, theoretical studies have dealt almost exclusively with independent models of morphology and electrokinetics. Introduction of a distinct Cahn-Hilliard-Poisson type mean-field framework for pure molten salts (i.e., in the absence of any neutral component), allows a systematic coupling between morphological evolution and the electrokinetic phenomena, such as transient currents. Specifically, linear analysis shows that spatially periodic patterns form via a finite wavenumber instability and numerical simulations demonstrate that while labyrinthine type patterns develop in the bulk, lamellar structures are favored near charged surfaces. The results demonstrate a qualitative phenomenology that is observed empirically and thus, provide a physically consistent methodology to incorporate phase separation properties into an electrochemical framework. PMID:26954098

  8. Equation of state, initiation, and detonation of pure ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Robbins, D. L.; Sheffield, S. A.; Dattelbaum, D. M.; Velisavljevic, N.; Stahl, D. B.

    2009-06-01

    Ammonium nitrate (AN) is a widely used fertilizer and mining explosive throughout the world. One of the more common explosives using AN is called ANFO, a mixture of AN prills and fuel oil in a 94:6 ratio by weight. The AN prills are specially made to absorb the fuel oil, forming a mixture that reacts under shock loading through a diffusion-controlled process, resulting in a non-ideal explosive with detonation velocities around 4 km/s. While there are a number of studies on ANFO, there are only a few studies relating to the equation of state (EOS) and detonation properties of pure AN - resulting mainly from studies of accidents that have occurred during transportation of large quantities of AN. We present the results of a series of gas gun-driven plate impact experiments on pressed AN ranging in density from 1.72 to 0.9 g/cm^3. Several of the high density experiments were performed in front surface impact geometry, in which pressed AN disks were built into the projectile front and impacted onto LiF windows. Additional experiments at low density have been done in ``half cell'' multiple magnetic gauge gun experiments. From this work a complete unreacted EOS has been developed, as well as some initiation and detonation information. Additional high pressure x-ray diffraction experiments in diamond anvil cells have provided a static isotherm for AN.

  9. Review: genetics and neuropathology of primary pure dystonia.

    PubMed

    Paudel, R; Hardy, J; Revesz, T; Holton, J L; Houlden, H

    2012-10-01

    Neuropathology has been the key to understanding the aetiology of many neurological disorders such as Alzheimer's disease, Parkinson's disease, frontotemporal degeneration and cerebellar ataxias. Dystonia shares many clinical features with these conditions but research in general, has been unrewarding in providing information on disease processes. Neuropathological studies are few in number and only limited morphological abnormalities have been described. In the genetic literature, dystonia loci are represented as DYT and are assigned ascending numerals chronologically as they are identified. This review will concentrate on the neuropathology of primary pure dystonia, focusing on DYT1 and DYT6 and the correlation between clinical and genetic findings. Research in this area is incomplete and confounded by the rarity of post mortem brain tissue. However, recent findings, indicating a direct interaction between the torsinA (TOR1A) gene responsible for DYT1 and the thanatos-associated domain-containing apoptosis-associated protein 1 (THAP1) gene responsible for DYT6, have important implications in understanding these two entities and also for other members of this group of disorders. PMID:22897341

  10. Pureed cannellini beans can be substituted for shortening in brownies.

    PubMed

    Szafranski, Michele; Whittington, Julianne Allen; Bessinger, Carlton

    2005-08-01

    Studies have shown white beans to be an effective fat replacer in dropped cookies. However, research is needed to determine whether legumes may be an effective replacement for fat in other types of cookies. This study determined the overall acceptability, sensory characteristics, and nutrient content of brownies (bar cookie) made using cannellini beans as a replacement for shortening. Cannellini beans were used to replace 25%, 50%, and 75% of the shortening (by weight) in a control brownie formula. One hundred twenty untrained panelists participated in rating the brownies on a seven-point hedonic scale. Analysis of variance conducted on the acceptability and sensory characteristics indicated a statistically significant effect when replacing fat with beans for acceptability, tenderness, texture, and flavor (P<.05). Post-hoc testing (Scheffe's test) indicated that neither the 25% nor the 50% bean brownies were significantly different from the control in overall acceptability, tenderness, texture, or flavor. Also, the 50% bean brownies, compared with control, had 2.6 g less fat and 21 fewer kcal per 1.4-oz serving. This study demonstrated that pureed cannellini beans can replace as much as 50% of the fat (by weight) in brownies, while yielding an acceptable and more nutritious product.

  11. Diffusion bonding of commercially pure Ni using Cu interlayer

    SciTech Connect

    Rahman, A.H.M.E. Cavalli, M.N.

    2012-07-15

    The concentration dependence of diffusivity in a multi-component diffusion system makes it complicated to predict the concentration profiles of diffusing species. This so called chemical diffusivity can be expressed as a function of thermodynamic and kinetic data. DICTRA software can calculate the concentration profiles using appropriate mobility and thermodynamic data. It can also optimize the diffusivity data using experimental diffusivity data. Then the optimized diffusivity data is stored as mobility data which is a linear function of temperature. In this work, diffusion bonding of commercially pure Ni using Cu interlayers is reported. The mobility parameters of Ni-Cu alloy binary systems were optimized using DICTRA/Thermocalc software from the available self-, tracer and chemical diffusion coefficients. The optimized mobility parameters were used to simulate concentration profiles of Ni-Cu diffusion joints using DICTRA/Thermocalc software. The calculated and experimental concentration profiles agreed well at 1100 Degree-Sign C. Agreement between the simulated and experimental profiles was less good at 1050 Degree-Sign C due to the grain boundary contribution to the overall diffusion. - Highlights: Black-Right-Pointing-Pointer The concentration profiles of Cu in Ni-Cu diffusion joints are modeled. Black-Right-Pointing-Pointer Interdiffusion coefficients in Ni-Cu system are optimized. Black-Right-Pointing-Pointer Optimized interdiffusion coefficients are expressed as mobility parameters. Black-Right-Pointing-Pointer Simulated profiles are comparable with experimental profiles.

  12. Intracellular Neural Recording with Pure Carbon Nanotube Probes

    PubMed Central

    Yoon, Inho; Hamaguchi, Kosuke; Borzenets, Ivan V.; Finkelstein, Gleb; Mooney, Richard; Donald, Bruce R.

    2013-01-01

    The computational complexity of the brain depends in part on a neuron’s capacity to integrate electrochemical information from vast numbers of synaptic inputs. The measurements of synaptic activity that are crucial for mechanistic understanding of brain function are also challenging, because they require intracellular recording methods to detect and resolve millivolt- scale synaptic potentials. Although glass electrodes are widely used for intracellular recordings, novel electrodes with superior mechanical and electrical properties are desirable, because they could extend intracellular recording methods to challenging environments, including long term recordings in freely behaving animals. Carbon nanotubes (CNTs) can theoretically deliver this advance, but the difficulty of assembling CNTs has limited their application to a coating layer or assembly on a planar substrate, resulting in electrodes that are more suitable for in vivo extracellular recording or extracellular recording from isolated cells. Here we show that a novel, yet remarkably simple, millimeter-long electrode with a sub-micron tip, fabricated from self-entangled pure CNTs can be used to obtain intracellular and extracellular recordings from vertebrate neurons in vitro and in vivo. This fabrication technology provides a new method for assembling intracellular electrodes from CNTs, affording a promising opportunity to harness nanotechnology for neuroscience applications. PMID:23840357

  13. Stress Wave Isolation by Purely Mechanical Topological Phononic Crystals.

    PubMed

    Chaunsali, Rajesh; Li, Feng; Yang, Jinkyu

    2016-01-01

    We present an active, purely mechanical stress wave isolator that consists of short cylindrical particles arranged in a helical architecture. This phononic structure allows us to change inter-particle stiffness dynamically by controlling the contact angles of the cylinders. We use torsional travelling waves to control the contact angles, thereby imposing a desired spatio-temporal stiffness variation to the phononic crystal along the longitudinal direction. Such torsional excitation is a form of parametric pumping in the system, which results in the breakage of the time-reversal symmetry. We report that, in quasi-static sense, the system shows topologically non-trivial band-gaps. However, in a dynamic regime where the pumping effect is significant, these band-gaps become asymmetric with respect to the frequency and wavenumber domains in the dispersion relationship. By using numerical simulations, we show that such asymmetry has a direct correspondence to the topological invariant, i.e., Chern number, of the system. We propose that this asymmetry, accompanied by selective inter-band transition, can be utilized for directional isolation of the stress wave propagating along the phononic crystal. PMID:27477236

  14. Quantum entanglement swapping of two arbitrary biqubit pure states

    NASA Astrophysics Data System (ADS)

    Xie, ChuanMei; Liu, YiMin; Chen, JianLan; Yin, XiaoFeng; Zhang, ZhanJun

    2016-10-01

    In this paper, the issue of swapping quantum entanglements in two arbitrary biqubit pure states via a local bipartite entangledstate projective measure in the middle node is studied in depth, especially with regard to quantitative aspects. Attention is mainly focused on the relation between the measure and the final entanglement obtained via swapping. During the study, the entanglement of formation (EoF) is employed as a quantifier to characterize and quantify the entanglements present in all involved states. All concerned EoFs are expressed analytically; thus, the relation between the final entanglement and the measuring state is established. Through concrete analyses, the measure demands for getting a certain amount of a final entanglement are revealed. It is found that a maximally entangled final state can be obtained from any two given initial entangled states via swapping with a certain probability; however, a peculiar measure should be performed. Moreover, some distinct properties are revealed and analyzed. Such a study will be useful in quantum information processes.

  15. Geometric local invariants and pure three-qubit states

    SciTech Connect

    Williamson, Mark S.; Ericsson, Marie; Johansson, Markus; Sjoeqvist, Erik; Sudbery, Anthony; Vedral, Vlatko; Wootters, William K.

    2011-06-15

    We explore a geometric approach to generating local SU(2) and SL(2,C) invariants for a collection of qubits inspired by lattice gauge theory. Each local invariant or ''gauge'' invariant is associated with a distinct closed path (or plaquette) joining some or all of the qubits. In lattice gauge theory, the lattice points are the discrete space-time points, the transformations between the points of the lattice are defined by parallel transporters, and the gauge invariant observable associated with a particular closed path is given by the Wilson loop. In our approach the points of the lattice are qubits, the link transformations between the qubits are defined by the correlations between them, and the gauge invariant observable, the local invariants associated with a particular closed path, are also given by a Wilson looplike construction. The link transformations share many of the properties of parallel transporters, although they are not undone when one retraces one's steps through the lattice. This feature is used to generate many of the invariants. We consider a pure three-qubit state as a test case and find we can generate a complete set of algebraically independent local invariants in this way; however, the framework given here is applicable to generating local unitary invariants for mixed states composed of any number of d-level quantum systems. We give an operational interpretation of these invariants in terms of observables.

  16. Dirac Node Lines in Pure Alkali Earth Metals

    NASA Astrophysics Data System (ADS)

    Li, Ronghan; Ma, Hui; Cheng, Xiyue; Wang, Shoulong; Li, Dianzhong; Zhang, Zhengyu; Li, Yiyi; Chen, Xing-Qiu

    2016-08-01

    Beryllium is a simple alkali earth metal, but has been the target of intensive studies for decades because of its unusual electron behavior at surfaces. The puzzling aspects include (i) severe deviations from the description of the nearly free-electron picture, (ii) an anomalously large electron-phonon coupling effect, and (iii) giant Friedel oscillations. The underlying origins for such anomalous surface electron behavior have been under active debate, but with no consensus. Here, by means of first-principles calculations, we discover that this pure metal system, surprisingly, harbors the Dirac node line (DNL) that in turn helps to rationalize many of the existing puzzles. The DNL is featured by a closed line consisting of linear band crossings, and its induced topological surface band agrees well with previous photoemission spectroscopy observations on the Be (0001) surface. We further reveal that each of the elemental alkali earth metals of Mg, Ca, and Sr also harbors the DNL and speculate that the fascinating topological property of the DNL might naturally exist in other elemental metals as well.

  17. Stress Wave Isolation by Purely Mechanical Topological Phononic Crystals

    NASA Astrophysics Data System (ADS)

    Chaunsali, Rajesh; Li, Feng; Yang, Jinkyu

    2016-08-01

    We present an active, purely mechanical stress wave isolator that consists of short cylindrical particles arranged in a helical architecture. This phononic structure allows us to change inter-particle stiffness dynamically by controlling the contact angles of the cylinders. We use torsional travelling waves to control the contact angles, thereby imposing a desired spatio-temporal stiffness variation to the phononic crystal along the longitudinal direction. Such torsional excitation is a form of parametric pumping in the system, which results in the breakage of the time-reversal symmetry. We report that, in quasi-static sense, the system shows topologically non-trivial band-gaps. However, in a dynamic regime where the pumping effect is significant, these band-gaps become asymmetric with respect to the frequency and wavenumber domains in the dispersion relationship. By using numerical simulations, we show that such asymmetry has a direct correspondence to the topological invariant, i.e., Chern number, of the system. We propose that this asymmetry, accompanied by selective inter-band transition, can be utilized for directional isolation of the stress wave propagating along the phononic crystal.

  18. The evolution of pure alexia: a longitudinal study of recovery.

    PubMed

    Behrmann, M; Black, S E; Bub, D

    1990-10-01

    This case report documents the partial recovery, over a 12-month period, of pure alexia in an adult female following a left occipital infarction. Measures of speed and accuracy were obtained on an oral reading and a lexical decision task immediately postonset and then on 10 subsequent occasions. Explicit letter-by-letter reading was observed only during the first week poststroke but a significant effect of word length was seen in all testing sessions. Reading accuracy was relatively good at all stages and reading latency showed a remarkable decrease over time but did not reach normal reading rates. The inability to use higher-order orthographic knowledge, as manifest in the absence of a word superiority effect, was still noted at one year postonset. We therefore concluded that the change in behavior was attributable to increased proficiency in the use of the adaptive letter-by-letter procedure rather than to the resolution of the underlying deficit. It is suggested that longitudinal neurobehavioral studies add to our understanding of the alexic deficit and provide insight into the recovery process. PMID:2285860

  19. TMED-4 INTERIM REPORT PURE ZR EQUILIBRIUM TEST RESULTS

    SciTech Connect

    Korinko, P.; Morgan, G.

    2010-12-17

    Due to higher than expected permeation rates in the production of tritium in the TVA, a development and testing program was implemented to develop the understanding of why the higher rates were occurring. In addition, improved data are needed for both the design as well as the predictive models. One part of the program was to determine the equilibrium pressure of hydrogen and tritium over NPZ (1). During the course of this testing, some curious results were discovered (2) compared to the published literature data (3). Due to these apparently results, a follow-on task was undertaken to determine the equilibrium pressure of protium and deuterium over pure zirconium. A series of experiments were conducted to determine equilibrium pressures and isotherm data for the zirconium - protium and zirconium - deuterium systems. The data match the published literature data reasonably well with the plateau extending to loadings of about 1.4. There is a significant pressure rise for loadings greater than 1.7.

  20. Chimera states in purely local delay-coupled oscillators.

    PubMed

    Bera, Bidesh K; Ghosh, Dibakar

    2016-05-01

    We study the existence of chimera states in a network of locally coupled chaotic and limit-cycle oscillators. The necessary condition for chimera state in purely local coupled oscillators is discussed. At first, we numerically observe the existence of chimera or multichimera states in the locally coupled Hindmarsh-Rose neuron model. We find that delay time in the nonlinear local coupling reduces the domain of the coherent island in the parameter space of the synaptic coupling strength and time delay, and thus the coherent region can be completely eliminated once the time delay exceeds a certain threshold. We then consider another form of nonlinearity in the local coupling, and the existence of chimera states is observed in the time-delayed Mackey-Glass system and in a Van der Pol oscillator. We also discuss the effect of time delay in local coupling for the existence of chimera states in Mackey-Glass systems. The nonlinearity present in the coupling function plays a key role in the emergence of chimera or multichimera states. A phase diagram for the chimera state is identified over a wide parameter space.

  1. Passive interferometric symmetries of multimode Gaussian pure states

    NASA Astrophysics Data System (ADS)

    Gabay, Natasha; Menicucci, Nicolas C.

    2016-05-01

    As large-scale multimode Gaussian states begin to become accessible in the laboratory, their representation and analysis become a useful topic of research in their own right. The graphical calculus for Gaussian pure states provides powerful tools for their representation, while this work presents a useful tool for their analysis: passive interferometric (i.e., number-conserving) symmetries. Here we show that these symmetries of multimode Gaussian states simplify calculations in measurement-based quantum computing and provide constructive tools for engineering large-scale harmonic systems with specific physical properties, and we provide a general mathematical framework for deriving them. Such symmetries are generated by linear combinations of operators expressed in the Schwinger representation of U (2 ) , called nullifiers because the Gaussian state in question is a zero eigenstate of them. This general framework is shown to have applications in the noise analysis of continuous-various cluster states and is expected to have additional applications in future work with large-scale multimode Gaussian states.

  2. Fabrication of Ultralow Density Interconnected Pure Metal Foams

    NASA Astrophysics Data System (ADS)

    Burks, Edward C.; Gilbert, Dustin A.; Liu, Kai; Kucheyev, Sergei O.; Colvin, Jeffrey D.; Felter, Thomas E.

    Ultra-low density metallic nanostructures have been shown to possess interesting thermal, electrical, magnetic, chemical and mechanical properties due to their extremely high surface areas, nanoscale geometries and high porosities. Here we report the synthesis of pure metal foams using interconnected metallic nanowires with densities as low as 0.1% of their bulk density that are still mechanically stable. The highly porous monoliths are macroscopic in size (several mm) and can be created in a wide variety of shapes for application-specific needs. Preliminary studies of such metal foams have already revealed fascinating mechanical and magnetic properties, since the physical dimensions of the foams are below some of the basic length scales that govern the material properties. These foams have been used as targets for ultrabright x-ray sources. They also have a wide variety of other potential applications such as photovoltaic devices, supercapacitors, catalysts, coatings, fuel cells, etc. This work has been supported by DTRA #BRCALL08-Per3-C-2-0006, and in part by NSF DMR-1008791 and DMR-1543582. Work at LLNL was performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  3. Pure keratin membrane and fibers from chicken feather.

    PubMed

    Ma, Bomou; Qiao, Xue; Hou, Xiuliang; Yang, Yiqi

    2016-08-01

    In this research, keratin was extracted from the disposable chicken feather using l-cysteine as reducing agent. Then, it was re-dissolved in the sodium carbonate-sodium bicarbonate buffer, and the pure keratin membrane and fiber were fabricated by doctor-blade casting process and wet spinning method, respectively. Scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to characterize the chemical and physical properties of resulting powder, membrane and fiber. Compared with the raw chicken feather, the regenerated keratin materials retain its chemical structure and thermal stability, their relative crystallinity is a little different depend on the shaping method, which leads to the difference in moisture regain. The mechanical results show that tensile strength of the keratin membrane researches 3.5MPa, have potential application in biomedical fields. However, the keratin fiber presents low tenacity, i.e. 0.5cN/dtex, this problem should be solved in order to apply the new fiber in textile and material science. PMID:27180293

  4. The synthesis of nanostructured, phase pure catalysts by hydrodynamic cavitation

    SciTech Connect

    Moser, W.R.; Sunstrom, J.E.; Marshik-Geurts, B.J.

    1995-12-01

    A new process for the synthesis of advanced catalytic materials based on performing the synthesis under hydrodynamic cavitation conditions has been discovered. This continuous process for catalyst synthesis resulted in the formation of both supported and unsupported catalysts. The advantage of the process over classical methods of synthesis is that it permits the formation of a wide variety of nanostructured catalysts in exceptionally high phase purities. The synthesis of platinum and palladium catalysts supported on alumina and other supports resulted in high dispersions of the noble metals. The synthesis of alpha, beta- and gamma-bismuth molybdates resulted in catalysts having superior phase purities as compared to several other classical methods of synthesis. The beta-bismuth molybdate was synthesized directly onto Cabosil. These studies showed that the particle size of the active component could be varied from a few manometers to much larger grains. The process enabled the synthesis of other complex metal oxides like perovskites as pure phases. The process uses a commercially available Microfluidizer.

  5. Irradiation hardening of pure tungsten exposed to neutron irradiation

    DOE PAGES

    Hu, Xunxiang; Koyanagi, Takaaki; Fukuda, Makoto; Kumar, N. A. P. Kiran; Snead, Lance L.; Wirth, Brian D.; Katoh, Yutai

    2016-08-26

    In this paper, pure tungsten samples have been neutron irradiated in HFIR at 90–850 °C to 0.03–2.2 dpa. A dispersed barrier hardening model informed by the available microstructure data has been used to predict the hardness. Comparison of the model predictions and the measured Vickers hardness reveals the dominant hardening contribution at various irradiation conditions. For tungsten samples irradiated in HFIR, the results indicate that voids and dislocation loops contributed to the hardness increase in the low dose region (<0.3 dpa), while the formation of intermetallic second phase precipitation, resulting from transmutation, dominates the radiation-induced strengthening beginning with a relativelymore » modest dose (>0.6 dpa). Finally, the precipitate contribution is most pronounced for the HFIR irradiations, whereas the radiation-induced defect cluster microstructure can rationalize the entirety of the hardness increase observed in tungsten irradiated in the fast neutron spectrum of Joyo and the mixed neutron spectrum of JMTR.« less

  6. Ion-induced nucleation of pure biogenic particles.

    PubMed

    Kirkby, Jasper; Duplissy, Jonathan; Sengupta, Kamalika; Frege, Carla; Gordon, Hamish; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K; Wagner, Robert; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill; Dias, Antonio; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P; Pringle, Kirsty; Rap, Alexandru; Richards, Nigel A D; Riipinen, Ilona; Rissanen, Matti P; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E; Seinfeld, John H; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander L; Wagner, Andrea C; Wagner, Paul E; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M; Worsnop, Douglas R; Baltensperger, Urs; Kulmala, Markku; Carslaw, Kenneth S; Curtius, Joachim

    2016-05-26

    Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere, and that ions have a relatively minor role. Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded. Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of α-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported by quantum chemical calculations of the cluster binding energies of representative HOMs. Ion-induced nucleation of pure organic particles constitutes a potentially widespread source of aerosol particles in terrestrial environments with low sulfuric acid pollution. PMID:27225125

  7. Eruptive shearing of tube pumice: pure and simple

    NASA Astrophysics Data System (ADS)

    Dingwell, Donald B.; Lavallée, Yan; Hess, Kai-Uwe; Flaws, Asher; Marti, Joan; Nichols, Alexander R. L.; Gilg, H. Albert; Schillinger, Burkhard

    2016-09-01

    Understanding the physicochemical conditions extant and mechanisms operative during explosive volcanism is essential for reliable forecasting and mitigation of volcanic events. Rhyolitic pumices reflect highly vesiculated magma whose bubbles can serve as a strain indicator for inferring the state of stress operative immediately prior to eruptive fragmentation. Obtaining the full kinematic picture reflected in bubble population geometry has been extremely difficult, involving dissection of a small number of delicate samples. The advent of reliable high-resolution tomography has changed this situation radically. Here we demonstrate via the use of tomography how a statistically powerful picture of the shapes and connectivity of thousands of individual bubbles within a single sample of tube pumice emerges. The strain record of tube pumice is modelled using empirical models of bubble geometry and liquid rheology, reliant on a constraint of magmatic water concentration. FTIR analysis reveals an imbalance in water speciation, suggesting post-eruption hydration, further supported by hydrogen and oxygen isotope measurements. Our work demonstrates that the strain recorded in the tube pumice dominated by simple shear (not pure shear) in the late deformational history of vesicular magma before eruption. This constraint in turn implies that magma ascent is conditioned by a velocity gradient (across the conduit) at the point of origin of tube pumice. Magma ascent accompanied by simple shear should enhance high eruption rates inferred independently for these highly viscous systems.

  8. High Strength, Large Core Pure Silica Fibers For Laser Surgery

    NASA Astrophysics Data System (ADS)

    Skutnik, B. J.; Hodge, M. H.; Clarkin, J. P.

    1988-06-01

    Recently many researchers, doctors and instrument companies have begun developing fiber optic laser power delivery systems to accomplish less traumatic surgery or localized irradiation treatment(1). With high power levels, particularly in short bursts, large core fibers are needed to keep the power densities from approaching the damage threshold of silica. Among the many advantages of using optical fibers in laser surgery are the following: microsurgery can be employed, trauma is reduced, access to interior through catheter introduction into vascular, gastrointestinal or respiratory tracts, accurate application of laser power through a flexible lightweight medium to provide localized irradiation as well as surgical removal, and the devices are sterilizable and of moderate cost permitting one-time use (disposable) probes. To achieve these wonderful gains in surgical procedures, the optical fibers must satisfy many optical and mechanical requirements. In use the optical fibers are often required to bend around curves or obstructions to reach the desired application area. Large tensile stresses can occur on the outer radius of the bent fiber, especially with large core fibers, thus high strength fibers are needed. Furthermore, since body fluids are primarily water, stress corrosion and fatigue(2-6) will occur. Therefore, the fibers should have excellent fatigue resistance as well as high strength. This paper further describes these requirements and presents details about an optical fiber which meets these requirements and provides additional very useful properties. These fibers with pure silica cores are called Hard Clad Silica, HCS*, fibers because of their hard bonded cladding over silica structure.

  9. Pyrrolizidine alkaloids of Echium vulgare honey found in pure pollen.

    PubMed

    Boppré, Michael; Colegate, Steven M; Edgar, John A

    2005-02-01

    The pyrrolizidine alkaloids previously identified in floral honey attributed to Echium vulgare (Boraginaceae) have been detected (8000-14 000 ppm) in pure pollen collected from the anthers of Echium vulgare. Pyrrolizidine alkaloids and/or their N-oxides were isolated from the aqueous acid extracts of pollen by use of strong cation-exchange, solid-phase extraction and identified by liquid chromatographic/mass spectrometric (LCMS) analysis. The pyrrolizidine alkaloids in the pollen are present mainly as the N-oxides. In addition to seven previously described pyrrolizidine alkaloids and/or their N-oxides (echimidine, acetylechimidine, uplandicine, 9-O-angelylretronecine, echiuplatine, leptanthine, and echimiplatine), one unidentified (echivulgarine), but previously found in honey, and two previously undescribed (vulgarine and 7-O-acetylvulgarine) pyrrolizidine alkaloids and/or their N-oxides were identified in the pollen. Tentative structures for these unidentified pyrrolizidine alkaloids are proposed on the basis of the mass spectrometric data and biogenetic considerations. The implications of these results for identifying the source and subsequent concentrations of pyrrolizidine alkaloids in honeys and commercial bee pollen are briefly discussed. PMID:15686407

  10. Mevva ion source operated in purely gaseous mode

    SciTech Connect

    Yushkov, G.Y.; MacGill, R.A.; Brown, I. G.

    2003-03-27

    We have operated a vacuum arc ion source in such a way as to form beams of purely gaseous ions. The vacuum arc configuration that is conventionally used to produce intense beams of metal ions was altered so as to form gaseous ion beams, with only minimal changes to the external circuitry and no changes at all internally to the ion source. In our experiments we formed beams from oxygen (O{sup +} and O{sub 2}{sup +}), nitrogen (N{sup +} and N{sub 2}{sup +}), argon (Ar{sup +}) and carbon dioxide (C{sup +}, CO{sub 2}{sup +}, O{sup +} and O{sub 2}{sup +}) at extraction voltage of 2 to 50 kV. We used a pulsed mode of operation, with beam pulses approximately 50 milliseconds long and repetition rate 10 pulses per second, for a duty cycle of about 50%. Downstream ion beam current as measured by a 5 cm diameter Faraday cup was typically 0.5 mA pulse or about 250 {micro}A time averaged. This time averaged beam current is very similar to that obtained for metal ions when the source is operated in the usual vacuum arc mode. Here we describe the modifications made to the source and the results of our investigations.

  11. The formation of pure anorthosite on the Moon

    NASA Astrophysics Data System (ADS)

    Piskorz, Danielle; Stevenson, David J.

    2014-09-01

    The giant impact hypothesis for the origin of the Moon points to the creation of a hot, young Moon, likely with a global magma ocean. Such a magma ocean would produce a flotation crust of plagioclase crystals, or an anorthositic crust. Early calculations of the expected anorthosite content of the lunar highlands crust did not match initial measurements of Apollo samples, and more recently have not matched Clementine measurements or SELENE measurements, because they assumed interstitial melt would freeze. We consider a physical model of a magma ocean with an accumulating flotation lid, and find that significant escape of melt can take place for reasonable physical parameters and timescales of melt migration, even allowing for the inhibiting effect of plausible compaction viscosities. This model permits more nearly pure lunar anorthosites, consistent with observations. The model encounters some difficulty in explaining the expulsion of melt for the near-surface crust (up to five-kilometers’ depth) that presumably dominates the Apollo samples, suggesting that impact mixing and tidal heating are needed to explain the discrepancy.

  12. One-year follow-up of patients with cluster C personality disorders: a prospective study comparing patients with "pure" and comorbid conditions within cluster C, and "pure" C with "pure" cluster A or B conditions.

    PubMed

    Gude, T; Vaglum, P

    2001-06-01

    This one-year, post-treatment prospective study of consecutively admitted patients to a national psychiatric in-patient clinic, compares patients belonging to four subgroups of DSM-III-R personality disorder (PDs): "pure cluster A (N = 21), "pure" B (N = 67), "pure" C (N = 251), and Axis II "comorbid" C (N = 138). Outcome was measured by SCl-90 and occupational status. Axis I disorders were controlled for in all analyses. Contrary to our hypothesis, patients in pure cluster C had no better outcome than either Axis II comorbid cluster C patients or patients with pure cluster A or B. Although pure C patients relapsed in symptom distress after discharge, comorbid C patients did not. C patients with an additional Histrionic PD were less at risk to be a case at follow up (GSI level > 1.00). Cluster C disorders as a whole had negative impact upon outcome in the total sample. These findings suggest the need for better treatment of patients with cluster C conditions.

  13. Surface roughening of superalloys by high pressure pure waterjet

    SciTech Connect

    Taylor, T.A.

    1995-12-31

    A high pressure waterjet has been used to study the surface roughening of superalloys as preparation for thermal spraying. Designed experiments for Mar-M 509 and Rene 80 were carried out for the effects of jet pressure and mass of water delivered per unit area. Comparisons were made of several superalloys in terms of erosion, surface roughness and topology. The mechanism of jet erosion of Rene 80 was studied in relation to its metallurgical microstructure. An MCrAlY coating by shrouded plasma spray was made over a waterjet prepared surface with excellent bonding and having an ideally clean interface.

  14. Laser remelting of Ti6AL4V using high power diode laser

    NASA Astrophysics Data System (ADS)

    Amaya-Vázquez, M. R.; Sánchez-Amaya, J. M.; Boukha, Z.; El Amrani, K.; Botana, F. J.

    2012-04-01

    Titanium alloys present excellent mechanical and corrosion properties, being widely employed in different industries such as medical, aerospace, automotive, petrochemical, nuclear and power generation, etc. Ti6Al4V is the α-β alloy most employed in industry. The modification of its properties can be achieved with convectional heat treatments and/or with laser processing. Laser remelting (LR) is a technology applied to Ti6Al4V by other authors with excimer and Nd-Yag laser with pure argon shielding gas to prevent risk of oxidation. In the present contribution, laser remelting has been applied for the first time to Ti6Al4V with a high power diode laser (with pure argon as shielding gas). Results showed that remelted samples (with medium energy densities) have higher microhardness and better corrosion resistance than Ti6Al4V base metal.

  15. Single Molecule Visualization of DNA in Pure Shear Flow

    NASA Astrophysics Data System (ADS)

    Smith, Connie; Duggal, Rajat; Pasquali, Matteo

    2003-03-01

    Polymers are ever-present in society from plastic bottles to DNA. The study of single molecule dynamics will provide the opportunity for advances in fields from synthetic polymer coatings to gene therapy. Many applications involve flow of dilute polymer solutions in viscous solvents. These long, flexible polymer chains (DNA) are coiled at rest in solution. The configuration of the molecules is altered by the applied flow which, in turn, affects the dynamics of the flow. Control of flow allows for manipulation of the DNA molecules. Our apparatus consists of a rectangular channel that has been plasma etched into a silicon wafer with pressure driven flow (pulse-free syringe pump). The dynamics of the DNA molecules in flow are monitored using fluorescence microscopy and digital imaging. The flow channel was designed to allow for visualization of the molecules in the plane defined by velocity and velocity gradient instead of the plane identified by the velocity and the vorticity (previously studied by Smith et al (1999) and LeDuc et al (1999)). Moreover, we can visualize the DNA in a flow where the velocity gradient is not uniform. The individual and average conformations (size and orientation) of the flowing DNA molecules are being studied as a function of the Weissenberg number (product of strain rate and DNA relaxation time) and distance from the channel walls.

  16. Improved photoluminescence property of CTAB assisted polyaniline-AlZnO nanocomposite

    SciTech Connect

    Mitra, Mousumi; Banerjee, Dipali; Kargupta, Kajari; Ganguly, Saibal

    2015-06-24

    Polyaniline-Al doped ZnO ((PANI-AlZnO:: 70:30) nanocomposite was prepared via in situ chemical oxidative polymerization, while the hexagonal powder of AlZnO was synthesized via sol-gel technique, using Hexadecyltrimethylammonium bromide (CTAB) as a capping agent. The prepared nanocomposite was characterized by High resolution transmission electron microscopy (HRTEM), EDAX, X-ray diffraction (XRD) and Fourier transforms infrared (FTIR) spectra. The optical property of the nanomaterials is examined by photoluminescence (PL) spectra analysis. The XRD pattern confirms the formation of Al doped ZnO as well as PANI. The HRTEM images of the composite showed the formation of hexagonal AlZnO embedded in polyaniline matrix. EDAX spectrum shows the compositional analysis of the nanocomposite. FTIR spectra confirm the formation of nanocomposite of PANI and hexagonal AlZnO. The PL intensity of the nanocomposite is improved as compared to pure AlZnO.

  17. The Effect of Premixed Al-Cu Powder on the Stir Zone in Friction Stir Welding of AA3003-H18

    NASA Astrophysics Data System (ADS)

    Abnar, B.; Kazeminezhad, M.; Kokabi, A. H.

    2015-02-01

    In this research, 3-mm-thick AA3003-H18 non-heat-treatable aluminum alloy plates were joined by friction stir welding (FSW). It was performed by adding pure Cu and premixed Cu-Al powders at various rotational speeds of 800, 1000, and 1200 rpm and constant traveling speeds of 100 mm/min. At first, the powder was filled into the gap (0.2 or 0.4 mm) between two aluminum alloy plates, and then the FSW process was performed in two passes. The microstructure, mechanical properties, and formation of intermetallic compounds were investigated in both cases of using pure Cu and premixed Al-Cu powders. The results of using pure Cu and premixed Al-Cu powders were compared in the stir zone at various rotational speeds. The copper particle distribution and formation of Al-Cu intermetallic compounds (Al2Cu and AlCu) in the stir zone were desirable using premixed Al-Cu powder into the gap. The hardness values were significantly increased by formation of Al-Cu intermetallic compounds in the stir zone and it was uniform throughout the stir zone when premixed Al-Cu powder was used. Also, longitudinal tensile strength from the stir zone was higher when premixed Al-Cu powder was used instead of pure Cu powder.

  18. High-performance Ni3Al synthesized from composite powders

    NASA Astrophysics Data System (ADS)

    Chiou, Wen-Chih; Hu, Chen-Ti

    1994-05-01

    Specimens of Ni3Al + B of high density (>99.3 Pct RD) and relatively large dimension have been synthesized from composite powders through processes of replacing plating and electroless Ni-B plating on Al powder, sintering, and thermal-mechanical treatment. The uniformly coated Ni layer over fine Al or Ni core particles constituting these coating/core composite powders has advantages such as better resistance to oxidation relative to pure Al powder, a greater green density as a compacted powder than prealloyed powder, the possibility of atomically added B to the material by careful choice of a suitable plating solution, and avoidance of the expensive powder metallurgy (PM) equipment such as a hot isostatic press (HIP), hot press (HP), etc. The final Ni3Al + B product is made from Ni-B-Al and Ni-B-Ni mixed composite powders by means of traditional PM processes such as compacting, sintering, rolling, and annealing, and therefore, the dimensions of the product are not constrained by the capacity of an HIP or HP. The properties of Ni3Al composite powder metallurgy (CPM) specimens tested at room temperature have been obtained, and comparison with previous reports is conducted. A tensile elongation of about 16 Pct at room temperature was attained.

  19. Energetics of nonequilibrium solidification in Al-Sm

    NASA Astrophysics Data System (ADS)

    Zhou, S. H.; Napolitano, R. E.

    2008-11-01

    Solution-based thermodynamic modeling, aided by first-principles calculations, is employed here to examine phase transformations in the Al-Sm binary system which may give rise to product phases that are metastable or have a composition that deviates substantially from equilibrium. In addition to describing the pure undercooled Al liquid with a two-state model that accounts for structural ordering, thermodynamic descriptions of the fcc phase, and intermediate compounds ( Al4Sm-β , Al11Sm3-α , Al3Sm-δ , and Al2Sm-σ ) are reanalyzed using special quasirandom structure and first-principles calculations. The possible phase compositions are presented over a range of temperatures using a “Baker-Cahn” analysis of the energetics of solidification and compared with reports of rapid solidification. The energetics associated with varying degrees of chemical partitioning are quantified and compared with experimental observations of the metastable Al11Sm3-α primary phase and reports of amorphous solids.

  20. Experimental and Theoretical Studies of the Pure Rotational Spectra of Lead Halides: PbF and PbCl

    NASA Astrophysics Data System (ADS)

    Norman, Spencer; Dawes, Richard; Grubbs, G. S., II; Cooke, S. A.; Long, B. E.; Dewberry, Chris

    2014-06-01

    The pure rotational spectrum of lead monochloride, PbCl, has been measured and analyzed using chirped pulse and cavity Fourier transform microwave (CP-FTMW and FTMW) spectrometers equipped with an ablation source. Refined parameters of an effective Hamiltonian including fine and hyperfine interactions similar to those previously reported by Fink et al. [1] were determined. Dynamically-weighted, explicitly-correlated MRCI-F12 calculations [2] were performed for both PbF and the valence isoelectronic PbCl to predict potential energy curves (PEC). Spin-orbit coupling was included in the calculations, which is known to split the X12Π1/2 and X22Π3/2 components of the ground electronic state by roughly 8280 wn in both lead halide systems. Calculated rotational levels were obtained using the PECs and compared with experiment including previously published results for PbF [3]. References: 1- K. Ziebarth, K. D. Setzer, O. Shestakov,1 and E. H. Fink, J. Mol. Spec. 191, 108 (1998). 2- B. J. Barker et al. J. Chem. Phys. 137, 214313 (2012). 3- R. J. Mawhorter et al. Phys. Rev. A 84, 022508 (2011).

  1. Focused electron beam induced deposition of pure SIO II

    NASA Astrophysics Data System (ADS)

    Perentes, Alexandre; Hoffmann, Patrik; Munnik, Frans

    2007-02-01

    Focused electron beam induced processing (FEBID) equipments are the "all in one" tools for high resolution investigation, and modification of nano-devices. Focused electron beam induced deposition from a gaseous precursor usually results in a nano-composite sub-structured material, in which the interesting material is embedded in an amorphous carbonaceous matrix. Using the Hydrogen free tetraisocyanatosilane Si(NCO) 4 molecule as Si source, we show how a controlled oxygen flux, simultaneously injected with the precursor vapors, causes contaminants to vanish from the FEB deposits obtained and leads to the deposition of pure SiO II. The chemical composition of the FEBID material could be controlled from SiC IINO 3 to SiO II, the latter containing undetectable foreign element contamination. The [O II] / [TICS] ratio needed to obtain SiO II in our FEB deposition equipment is larger than 300. The evolution of the FEBID material chemical composition is presented as function of the [O II] / [TICS] molecular flux ratios. A hypothetical decomposition pathway of this silane under these conditions is discussed based on the different species formed under electron bombardment of TICS. Transmission electron microscopy investigations demonstrated that the deposited oxide is smooth (roughness sub 2nm) and amorphous. Infrared spectroscopy confirmed the low concentration of hydroxyl groups. The Hydrogen content of the deposited oxide, measured by elastic recoil detection analysis, is as low as 1 at%. 193nm wavelength AIMS investigations of 125nm thick SiO II pads (obtained with [O II] / [TICS] = 325) showed an undetectable light absorption.

  2. Random pure states: Quantifying bipartite entanglement beyond the linear statistics

    NASA Astrophysics Data System (ADS)

    Vivo, Pierpaolo; Pato, Mauricio P.; Oshanin, Gleb

    2016-05-01

    We analyze the properties of entangled random pure states of a quantum system partitioned into two smaller subsystems of dimensions N and M . Framing the problem in terms of random matrices with a fixed-trace constraint, we establish, for arbitrary N ≤M , a general relation between the n -point densities and the cross moments of the eigenvalues of the reduced density matrix, i.e., the so-called Schmidt eigenvalues, and the analogous functionals of the eigenvalues of the Wishart-Laguerre ensemble of the random matrix theory. This allows us to derive explicit expressions for two-level densities, and also an exact expression for the variance of von Neumann entropy at finite N ,M . Then, we focus on the moments E {Ka} of the Schmidt number K , the reciprocal of the purity. This is a random variable supported on [1 ,N ] , which quantifies the number of degrees of freedom effectively contributing to the entanglement. We derive a wealth of analytical results for E {Ka} for N =2 and 3 and arbitrary M , and also for square N =M systems by spotting for the latter a connection with the probability P (xminGUE≥√{2 N }ξ ) that the smallest eigenvalue xminGUE of an N ×N matrix belonging to the Gaussian unitary ensemble is larger than √{2 N }ξ . As a by-product, we present an exact asymptotic expansion for P (xminGUE≥√{2 N }ξ ) for finite N as ξ →∞ . Our results are corroborated by numerical simulations whenever possible, with excellent agreement.

  3. Localization of 4D gravity on pure geometrical thick branes

    SciTech Connect

    Barbosa-Cendejas, Nandinii; Herrera-Aguilar, Alfredo

    2006-04-15

    We consider the generation of thick brane configurations in a pure geometric Weyl integrable 5D spacetime which constitutes a non-Riemannian generalization of Kaluza-Klein (KK) theory. In this framework, we show how 4D gravity can be localized on a scalar thick brane which does not necessarily respect reflection symmetry, generalizing in this way several previous models based on the Randall-Sundrum (RS) system and avoiding both, the restriction to orbifold geometries and the introduction of the branes in the action by hand. We first obtain a thick brane solution that preserves 4D Poincare invariance and breaks Z{sub 2}-symmetry along the extra dimension which, indeed, can be either compact or extended, and supplements brane solutions previously found by other authors. In the noncompact case, this field configuration represents a thick brane with positive energy density centered at y=c{sub 2}, whereas pairs of thick branes arise in the compact case. Remarkably, the Weylian scalar curvature is nonsingular along the fifth dimension in the noncompact case, in contraposition to the RS thin brane system. We also recast the wave equations of the transverse traceless modes of the linear fluctuations of the classical background into a Schroedinger's equation form with a volcano potential of finite bottom in both the compact and the extended cases. We solve Schroedinger equation for the massless zero mode m{sup 2}=0 and obtain a single bound wave function which represents a stable 4D graviton. We also get a continuum gapless spectrum of KK states with m{sup 2}>0 that are suppressed at y=c{sub 2} and turn asymptotically into plane waves.

  4. Random pure states: Quantifying bipartite entanglement beyond the linear statistics.

    PubMed

    Vivo, Pierpaolo; Pato, Mauricio P; Oshanin, Gleb

    2016-05-01

    We analyze the properties of entangled random pure states of a quantum system partitioned into two smaller subsystems of dimensions N and M. Framing the problem in terms of random matrices with a fixed-trace constraint, we establish, for arbitrary N≤M, a general relation between the n-point densities and the cross moments of the eigenvalues of the reduced density matrix, i.e., the so-called Schmidt eigenvalues, and the analogous functionals of the eigenvalues of the Wishart-Laguerre ensemble of the random matrix theory. This allows us to derive explicit expressions for two-level densities, and also an exact expression for the variance of von Neumann entropy at finite N,M. Then, we focus on the moments E{K^{a}} of the Schmidt number K, the reciprocal of the purity. This is a random variable supported on [1,N], which quantifies the number of degrees of freedom effectively contributing to the entanglement. We derive a wealth of analytical results for E{K^{a}} for N=2 and 3 and arbitrary M, and also for square N=M systems by spotting for the latter a connection with the probability P(x_{min}^{GUE}≥sqrt[2N]ξ) that the smallest eigenvalue x_{min}^{GUE} of an N×N matrix belonging to the Gaussian unitary ensemble is larger than sqrt[2N]ξ. As a by-product, we present an exact asymptotic expansion for P(x_{min}^{GUE}≥sqrt[2N]ξ) for finite N as ξ→∞. Our results are corroborated by numerical simulations whenever possible, with excellent agreement. PMID:27300829

  5. Pure red cell aplasia secondary to treatment with erythropoietin.

    PubMed

    Locatelli, Francesco; Del Vecchio, Lucia

    2003-01-01

    Pure red cell aplasia (PRCA) is a rare condition defined as severe anemia secondary to the virtual absence of red blood cell precursors in the bone marrow. In the setting of patients treated with rHuEPO, the disease is generated by epoetin-induced antibodies that neutralise all the exogenous rHuEPO and cross-react with endogenous erythropoietin. As a result, serum erythropoietin levels are undetectable and erythropoiesis becomes ineffective. Only 4 cases of PRCA associated with rh-EPO have been reported before 1998. Thereafter, a sharp increase in the incidence of this rare condition has been reported, mainly associated with epoetin alpha use outside the United States. A number of possible mechanisms leading to PRCA development have been identified. Among these, modification of drug formulation and down stream processing probably has had a major role. Indeed, in 1998 the formulation of epoetin alpha in Europe was modified because of the fear of the "mad cow" syndrome. However, differences in molecule structure and glycosylation among different epoetins can not be excluded. It should also be underlined that the rise in the incidence of PRCA cases has been coincident with a major shift from intravenous to subcutaneous administration of rHuEPO. The abrupt rise in the incidence of PRCA cases observed in the last few years, deserves particular attention; however, we have to balance its severity, but extreme rarity, with the high number of chronic kidney disease patients who die each year because of cardiovascular disease that could partially be reduced by anemia treatment. PMID:14696747

  6. Conductivity of pure graphene: Theoretical approach using the polarization tensor

    NASA Astrophysics Data System (ADS)

    Klimchitskaya, G. L.; Mostepanenko, V. M.

    2016-06-01

    We obtain analytic expressions for the conductivity of pristine (pure) graphene in the framework of the Dirac model using the polarization tensor in (2+1) dimensions defined along the real frequency axis. It is found that at both zero and nonzero temperature T the in-plane and out-of-plane conductivities of graphene are equal to each other with a high precision and essentially do not depend on the wave vector. At T =0 the conductivity of graphene is real and equal to σ0=e2/(4 ℏ ) up to small nonlocal corrections in accordance with many authors. At some fixed T ≠0 the real part of the conductivity varies between zero at low frequencies ω and σ0 for optical ω . If ω is fixed, the conductivity varies between σ0 at low T and zero at high T . The imaginary part of the conductivity of graphene is shown to depend on the ratio of ω to T . In accordance with the obtained asymptotic expressions, at fixed T it varies from infinity at ω =0 to a negative minimum value reached at some ω , and then approaches to zero with further increase of ω . At fixed ω the imaginary part of the conductivity varies from zero at T =0 , reaches a negative minimum at some T , and then goes to infinity together with T . The numerical computations of both the real and imaginary parts of the conductivity are performed. The above results are obtained in the framework of quantum electrodynamics at nonzero temperature and can be generalized for graphene samples with nonzero mass gap parameter and chemical potential.

  7. Video. Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy.

    PubMed

    Bessler, Marc; Gumbs, Andrew A; Milone, Luca; Evanko, John C; Stevens, Peter; Fowler, Dennis

    2010-09-01

    Enthusiasm for natural orifice transluminal endoscopic surgery (NOTES) has been partly tempered by the reality that most NOTES procedures to date have been laparoscopically assisted. After safely performing transvaginal cholecystectomy in an IACUC-approved porcine model, the authors embarked on an institution review board (IRB)-approved protocol for ultimate performance of pure NOTES cholecystectomy in humans. They describe their experience performing a true NOTES transvaginal cholecystectomy after safely accomplishing three laparoscopically assisted or hybrid procedures in humans. One of the patients was a 35-year-old woman presenting with symptoms of biliary colic. Ultrasound confirmed gallstones, and her liver enzymes were normal. Pneumoperitoneum to 15 mmHg was obtained via a transvaginal trocar placed through a colpotomy made under direct vision. A double-channel endoscope then was advanced into the abdomen. To overcome the retracting limitations of currently available endoscopes, the authors used an extra-long 5-mm articulating retractor placed into the abdomen via a separate colpotomy made under direct vision using the flexible endoscope in a retroflexed position. Endoscopically placed clips were used for control of both the cystic duct and the artery. These techniques obviated the need for any transabdominally placed instruments or needles. This patient was the first to undergo a completely NOTES cholecystectomy at the authors' institution, and to their knowledge, in the United States. She was discharged on the day of surgery and at this writing has not experienced any complication after 1 month of follow-up evaluation. Performance of NOTES transvaginal cholecystectomy without aid of laparoscopic or needleoscopic instruments is feasible and safe for humans. Additional experience with this technique are required before studies comparing it with standard laparoscopy and hybrid techniques are appropriate.

  8. Confinement of pure ion plasma in a cylindrical current sheet

    NASA Astrophysics Data System (ADS)

    Paul, Stephen F.; Chao, Edward H.; Davidson, Ronald C.; Phillips, Cynthia K.

    1999-12-01

    A novel method for containing a pure ion plasma at thermonuclear densities and temperatures has been modeled. The method combines the confinement principles of a Penning-Malmberg trap and a pulsed theta-pinch. A conventional Penning trap can confine a uniform-density plasma of about 5×1011cm-3 with a 30-Tesla magnetic field. However, if the axial field is ramped, a much higher local ion density can be obtained. Starting with a 107cm-3 trapped deuterium plasma at the Brillouin limit (B=0.6 Tesla), the field is ramped to 30 Tesla. Because the plasma is comprised of particles of only one sign of charge, transport losses are very low, i.e., the conductivity is high. As a result, the ramped field does not penetrate the plasma and a diamagnetic surface current is generated, with the ions being accelerated to relativistic velocities. To counteract the inward j×B forces from this induced current, additional ions are injected into the plasma along the axis to increase the density (and mutual electrostatic repulsion) of the target plasma. In the absence of the higher magnetic field in the center, the ions drift outward until a balance is established between the outward driving forces (centrifugal, electrostatic, pressure gradient) and the inward j×B force. An equilibrium calculation using a relativistic, 1-D, cold-fluid model shows that a plasma can be trapped in a hollow, 49-cm diameter, 0.2-cm thick cylinder with a density exceeding 4×1014cm-3.

  9. Thermoluminescence studies of γ-irradiated Al2O3:Ce3+ phosphor

    NASA Astrophysics Data System (ADS)

    Reddy, S. Satyanarayana; Nagabhushana, K. R.; Singh, Fouran

    2016-07-01

    Pure and Ce3+ doped Al2O3 phosphors were synthesized by solution combustion method. The synthesized samples were characterized by X-ray diffraction (XRD) and its shows α-phase of Al2O3. Crystallite size was estimated by Williamson-Hall (W-H) method and found to be 49, 59 and 84 nm for pure, 0.1 mol% and 1 mol% Ce3+ doped Al2O3 respectively. Trace elemental analysis of undoped Al2O3 shows impurities viz. Fe, Cr, Mn, Mg, Ti, etc. Photoluminescence (PL) spectra of Al2O3:Ce3+ shows emission at 367 nm and excitation peak at 273 nm, which are corresponding to 5D → 4F and 4F → 5D transitions respectively. PL intensity decreases with concentration up to 0.4 mol%, beyond this mol% PL intensity increases with doping concentration up to 2 mol%. Thermoluminescence (TL) studies of γ-rayed pure and Ce3+ doped Al2O3 have been studied. Two well resolved TL glow peaks at 457.5 K and 622 K were observed in pure Al2O3. Additional glow peak at 566 K was observed in Al2O3:Ce3+. Maximum TL intensity was observed for Al2O3:Ce3+ (0.1 mol%) beyond this TL intensity decreases with increasing Ce3+ concentration. Computerized glow curve deconvolution (CGCD) method was used to resolve the multiple peaks and to calculate TL kinetic parameters. Thermoluminescence emission (TLE) spectra of pure Al2O3 glow peaks (457.5 K and 622 K) shows sharp emission at 694 nm and two small humps at 672 nm and 709 nm. The sharp peak at 696 nm corresponds to Cr3+ impurity of 2Eg → 4A2g transition of R lines and 713 nm hump is undoubtedly belongs to Cr3+ emission of near neighbor pairs. The emission at 672 nm is characteristic of Mn4+ impurity ions of 2E → 4A2 transition. TLE of Al2O3:Ce3+ (0.1 mol%) shows additional broad emission at 412 nm corresponds to F-centers. Linearity is observed in the dose range 20-500 Gy in Al2O3:Ce3+ (1 mol%).

  10. Effects of B and S on Ni3Al grain boundaries

    SciTech Connect

    Voter, A.F.; Chen, S.P.; Albers, R.C.; Boring, A.M.; Hay, P.J.

    1988-01-01

    This report describes the procedure used to fit embedded atom style potentials to the pure elements Ni, Al, B and S and the cross potentials necessary for treating alloys and segregants. Grain boundary simulations, and results from molecular statics simulations using the potentials for B and S, and their cross potentials with Ni and Al, which was fit from electronic band structure calculations, are included. 21 refs., 1 fig., 3 tabs. (JL)

  11. Structural and electronic properties of a single Si chain doped zigzag AlN nanoribbon

    NASA Astrophysics Data System (ADS)

    Zhang, Jian-Min; Zhang, Jing; Xu, Ke-Wei

    2015-04-01

    The first-principles projector-augmented wave (PAW) potentials within the density function theory (DFT) framework have been used to determine the geometry structures and electronic properties of the zigzag edge AlN nanoribbons (ZAlNNRs) doped with a single Si chain under generalized gradient approximation (GGA). The average Al-Si, Si-Si, Al-N, Si-N, Al-H and N-H bond lengths are 2.39, 2.16, 1.83, 1.74, 1.59 and 1.03 Å, respectively. Pure 7-ZAlNNR is an indirect semiconductor with a large band gap of 2.235 eV, while a semiconductor to metal transformation is taken place after a single Si chain substituting for a single Al-N chain at various positions. In pure 7-ZAlNNR, the HVB and LCB are mainly attributed to the edge N and Al atoms, respectively, while in a single Si chain substituting doped 7-ZAlNNR, the HVB and LCB are mainly attributed to the Si atoms. The Al-N, Al-H and Al-Si bonds are ionic bond, the Si-Si and Si-H bonds are covalent bond, the N-H and N-Si bonds are covalent bond modified ionic bond.

  12. ALS superbend magnet system

    SciTech Connect

    Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

    2000-09-15

    The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

  13. Modulus measurements in ordered Co-Al, Fe-Al, and Ni-Al alloys

    NASA Technical Reports Server (NTRS)

    Harmouche, M. R.; Wolfenden, A.

    1985-01-01

    The composition and/or temperature dependence of the dynamic Young's modulus for the ordered B2 Co-Al, Fe-Al, and Ni-Al aluminides has been investigated using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The modulus has been measured in the composition interval 48.49 to 52.58 at. pct Co, 50.87 to 60.2 at. pct Fe, and 49.22 to 55.95 at. pct Ni for Co-Al, Fe-Al, and Ni-Al, respectively. The measured values for Co-Al are in the temperature interval 300 to 1300 K, while those for the other systems are for ambient temperature only. The data points show that Co-Al is stiffer than Fe-Al, which is stiffer than Ni-Al. The data points for Fe-Al and Ni-Al are slightly higher than those reported in the literature.

  14. The geometric measure of entanglement for a symmetric pure state with non-negative amplitudes

    SciTech Connect

    Hayashi, Masahito; Markham, Damian; Owari, Masaki; Virmani, Shashank

    2009-12-15

    In this paper for a class of symmetric multiparty pure states, we consider a conjecture related to the geometric measure of entanglement: ''for a symmetric pure state, the closest product state in terms of the fidelity can be chosen as a symmetric product state.'' We show that this conjecture is true for symmetric pure states whose amplitudes are all non-negative in a computational basis. The more general conjecture is still open.

  15. Typical pure states and the analysis of nonequilibrium processes of mesoscopic systems

    NASA Astrophysics Data System (ADS)

    Monnai, Takaaki; Sugita, Ayumu

    2016-05-01

    For isolated quantum many-body systems, we extend the availability of the intrinsic thermal nature of typical pure states to a class of nonequilibrium processes which start from an initial equilibrium. For concreteness, we calculate the spectral distribution of the work done on the system on the basis of a single pure state. It means that we can accurately calculate the entire fluctuation of the energy only from a single pure state instead of the thermodynamic ensembles.

  16. Computer Simulations of Ice Growth from Pure and Salty Water

    NASA Astrophysics Data System (ADS)

    Carignano, Marcelo

    2005-03-01

    A six-site water model recently proposed by H. Nada et al (J. Chem. Phys. 118, p7401, 2003) is extensively studied in relation to its ability to reproduce the growing of a crystal phase over the supercooled liquid. We perform Molecular Dynamics simulations at constant pressure and several temperatures below and above the melting temperature of the model, and the resulting kinetics is analyzed in terms of classical nucleation theory. The effect of adding dissociated sodium chloride on the kinetics of crystallization and the structure of water-ice interface is also studied. Preliminary results show that upon crystallization the ions occupy lattice position replacing Oxygen, and in all cases studied so far the ions are found in pairs.

  17. Classification scheme of pure multipartite states based on topological phases

    NASA Astrophysics Data System (ADS)

    Johansson, Markus; Ericsson, Marie; Sjöqvist, Erik; Osterloh, Andreas

    2014-01-01

    We investigate the connection between the concept of affine balancedness (a-balancedness) introduced by M. Johansson et al. [Phys. Rev. A 85, 032112 (2012), 10.1103/PhysRevA.85.032112] and polynomial local SU invariants and the appearance of topological phases, respectively. It is found that different types of a-balancedness correspond to different types of local SU invariants analogously to how different types of balancedness, as defined by A. Osterloh and J. Siewert, [New J. Phys. 12, 075025 (2010), 10.1088/1367-2630/12/7/075025], correspond to different types of local special linear (SL) invariants. These different types of SU invariants distinguish between states exhibiting different topological phases. In the case of three qubits, the different kinds of topological phases are fully distinguished by the three-tangle together with one more invariant. Using this, we present a qualitative classification scheme based on balancedness of a state. While balancedness and local SL invariants of bidegree (2n,0) classify the SL-semistable states [A. Osterloh and J. Siewert, New J. Phys. 12, 075025 (2010), 10.1088/1367-2630/12/7/075025; O. Viehmann et al., Phys. Rev. A 83, 052330 (2011), 10.1103/PhysRevA.83.052330], a-balancedness and local SU invariants of bidegree (2n-m,m) give a more fine-grained classification. In this scheme, the a-balanced states form a bridge from the genuine entanglement of balanced states, invariant under the SL group, towards the entanglement of unbalanced states characterized by U invariants of bidegree (n,n). As a byproduct, we obtain generalizations to the W state, i.e., states that are entangled, but contain only globally distributed entanglement of parts of the system.

  18. Microbial growth and the effects of mild acidification and preservatives in refrigerated sweet potato puree.

    PubMed

    Pérez-Díaz, Ilenys M; Truong, Van-Den; Webber, Ashlee; McFeeters, Roger F

    2008-03-01

    Refrigerated sweet potato puree is a convenient form of sweet potato that can be used as an ingredient in formulated foods. The microbiology of refrigerated sweet potato puree during storage for up to 5 weeks was evaluated. Because the puree was made by comminuting steam-cooked sweet potatoes before refrigeration, no naturally occurring vegetative bacterial cells were detected during a 4-week period of refrigerated storage at 4 degrees C. However, if postprocessing microbial contamination of the puree were to occur, contaminating microorganisms such as Listeria monocytogenes could grow during refrigerated storage. The effects of acidification or the addition of potassium sorbate and sodium benzoate on a population of L. monocytogenes inoculated into refrigerated (4 degrees C) sweet potato puree were determined. Inoculation of the refrigerated puree with L. monocytogenes at 10(6) CFU/ml resulted in a 3-log increase after 3 weeks storage of nonsupplemented puree. Supplementation of the sweet potato puree with 0.06% (wt/vol) sorbic acid or benzoic acid plus mild acidification of the sweet potato puree with citric acid to pH 4.2 prevented growth of L. monocytogenes during storage at 4 degrees C.

  19. Complete solution for unambiguous discrimination of three pure states with real inner products

    SciTech Connect

    Sugimoto, H.; Hashimoto, T.; Horibe, M.; Hayashi, A.

    2010-09-15

    Complete solutions are given in a closed analytic form for unambiguous discrimination of three general pure states with real mutual inner products. For this purpose, we first establish some general results on unambiguous discrimination of n linearly independent pure states. The uniqueness of solution is proved. The condition under which the problem is reduced to an (n-1)-state problem is clarified. After giving the solution for three pure states with real mutual inner products, we examine some difficulties in extending our method to the case of complex inner products. There is a class of set of three pure states with complex inner products for which we obtain an analytical solution.

  20. The Extended Crossover Peng-Robinson Equation of State for Describing the Thermodynamic Properties of Pure Fluids

    NASA Astrophysics Data System (ADS)

    Behnejad, Hassan; Cheshmpak, Hashem; Jamali, Asma

    2015-01-01

    In this paper, a theoretical method has been introduced for developing the crossover Peng-Robinson (CPR) equation of state (EoS) which incorporates the non-classical scaling laws asymptotically near the critical point into a classical analytic equation further away from the critical point. The CPR EoS has been adopted to describe the thermodynamic properties of some pure fluids (normal alkanes from methane to n-butane and carbon dioxide) such as density, saturated pressure, isochoric heat capacity and speed of sound. Unlike the original method for the crossover transformation made by Chen et al. (Phys Rev A 42:4470-4484, 1990), we have proposed a procedure which adding an additional term into the crossover transformation to obtain the thermophysical properties at the critical point more exactly. It is shown that this new crossover method yields a satisfactory representation of the thermodynamic properties close to the critical point for pure fluids relative to the original PR EoS.

  1. Models of pure CO2 and pure CH4 adsorption on the late paleozoic coals from the Kailuan Coalfield, Hebei, China

    USGS Publications Warehouse

    Dai, S.; Zhang, B.; Peng, S.; Zhang, X.; Chou, C.

    2009-01-01

    Isothermal adsorption experiments of pure CO2 and CH4 on different coals in rank (the No. 11 Coal from the Linnancang Mine and the No. 9 Coal from the Majiagou Mine) from the Kailuan Coalfield of Hebei Province, China, have been studied. Four different models (Langmuir, BET, D-R, and D-A) were used to fit the experimental data of CO2 and CH4 adsorption and their fitting degree were investigated. The results showed that the adsorption capacity of the Majiagou coal(Ro, ran = 1. 21%) is higher than that of the Linnancang coal (Ro, ran = 0. 58%). The adsorption capacity of CO2 is higher than that of CH4 on the same coal under the same pressure. The adsorption isotherms of pure CO 2 and pure CH4 on the Majiagou coal can be classified as Type I and their fitting errors of curves are very weak; thus the experimental data can be presented using the Langmuir isotherm. However, the adsorption of Linnancang coal is more complicated, and can be presented using D-A model because of its minimum error. Monolayer adsorption occurs during the adsorption of pure CO2 and pure CH4 on the No. 11 Coal and that of pure CH4 on the No. 9 Coal.

  2. Hydrothermal synthesis of Mg-Al hydrotalcites by urea hydrolysis

    SciTech Connect

    Rao, M. Mohan . E-mail: mandapati@iict.res.in; Reddy, B. Ramachandra; Jayalakshmi, M.; Jaya, V. Swarna; Sridhar, B.

    2005-02-15

    We report a simple method to prepare hydrotalcites involving both urea hydrolysis and hydrothermal synthetic conditions. Out of a series of Mg/Al ratios tried, pure hydrotalcite like phase was obtained for Mg/Al ratios of 1:1 and 2:1. Unlike in conventional co-precipitation method we succeeded in preparing Mg/Al ratio of 1:1 by this route. The high temperature (180 deg. C) applied and pressure developed in the autoclave during the synthesis might have altered the topochemical transformation. The materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared, thermo gravimetric and differential thermal analysis and transmission electron microscopy.

  3. Simulations of the Reaction-Diffusion System demonstrating the Transition from Purely Temporal to Spatio-Temporal Chaos

    NASA Astrophysics Data System (ADS)

    Olsen, Thomas; Hou, Yu; Trail, Collin; Wiener, Richard

    2004-11-01

    The Reaction-Diffusion model (H. Riecke and H.-G. Paap, Europhys. Lett. 14), 1235 (1991).has been applied to a wide variety of pattern forming systems. It correctly predicted a period doubling cascade to chaos in Taylor-Couette flow with hourglass geometry(Richard J. Wiener et al), Phys. Rev. E 55, 5489 (1997).. We have conducted a series of such simulations, varying the length of the system. This has enabled us to study the transition from a purely temporal chaos of the formation of new pairs of Taylor Vortices at a single location, to a spatio-temporal chaos of formation across a range of locations. Application to anticipated experiments will be discussed.

  4. Accelerated Partial Breast Irradiation for Pure Ductal Carcinoma in Situ

    SciTech Connect

    Park, Sean S.; Grills, Inga Siiner; Chen, Peter Y.; Kestin, Larry L.; Ghilezan, Michel I.; Wallace, Michelle; Martinez, Alvaro M.; Vicini, Frank A.

    2011-10-01

    Purpose: To report outcomes for ductal carcinoma in situ (DCIS) treated with breast-conserving therapy using accelerated partial breast irradiation (APBI). Methods and Materials: From March 2001 to February 2009, 53 patients with Stage 0 breast cancer were treated with breast conserving surgery and adjuvant APBI. Median age was 62 years. All patients underwent excision with margins negative by {>=}1 mm before adjuvant radiotherapy (RT). A total of 39 MammoSite brachytherapy (MS) patients and 14 three-dimensional conformal external beam RT (3DCRT) patients were treated to the lumpectomy bed alone with 34 Gy and 38.5 Gy, respectively. Of the DCIS cases, 94% were mammographically detected. All patients with calcifications had either specimen radiography or postsurgical mammography confirmation of clearance. Median tumor size was 6 mm, and median margin distance was 5 mm. There were no statistically significant differences according to APBI method for race/ethnicity, tumor detection method, tumor grade, estrogen receptor (ER) status, or use of tamoxifen (p = NS). Recurrence and survival were calculated using the Kaplan-Meier method. Cosmesis was scored by the Harvard criteria. Results: With a median follow-up of 3.6 years (range, 0.4-6.3 years), the overall and cause-specific survival rates were 98% and 100%, respectively. Three-year actuarial ipsilateral breast tumor recurrence was 2%. One failure was observed at the resection bed 11 months post-RT. No other elsewhere breast failures, regional recurrences, or distant metastases were noted. Cosmesis was excellent or good in 92.4% of cases, with no statistically significant differences according to the APBI method (92.3% with MammoSite and 92.8% with 3DCRT; p = 0.649). Conclusions: APBI as part of breast-conserving therapy for pure DCIS was associated with excellent local control and survival rates, with the vast majority of patients having good to excellent cosmesis. This finding supports the recent analysis by the

  5. Impacts of pure shocks in the BHR71 bipolar outflow

    NASA Astrophysics Data System (ADS)

    Gusdorf, A.; Riquelme, D.; Anderl, S.; Eislöffel, J.; Codella, C.; Gómez-Ruiz, A. I.; Graf, U. U.; Kristensen, L. E.; Leurini, S.; Parise, B.; Requena-Torres, M. A.; Ricken, O.; Güsten, R.

    2015-03-01

    Context. During the formation of a star, material is ejected along powerful jets that impact the ambient material. This outflow regulates star formation by e.g. inducing turbulence and heating the surrounding gas. Understanding the associated shocks is therefore essential to the study of star formation. Aims: We present comparisons of shock models with CO, H2, and SiO observations in a "pure" shock position in the BHR71 bipolar outflow. These comparisons provide an insight into the shock and pre-shock characteristics, and allow us to understand the energetic and chemical feedback of star formation on Galactic scales. Methods: New CO (Jup = 16, 11, 7, 6, 4, 3) observations from the shocked regions with the SOFIA and APEX telescopes are presented and combined with earlier H2 and SiO data (from the Spitzer and APEX telescopes). The integrated intensities are compared to a grid of models that were obtained from a magneto-hydrodynamical shock code, which calculates the dynamical and chemical structure of these regions combined with a radiative transfer module based on the "large velocity gradient" approximation. Results: The CO emission leads us to update the conclusions of our previous shock analysis: pre-shock densities of 104 cm-3 and shock velocities around 20-25 km s-1 are still constrained, but older ages are inferred (~4000 years). Conclusions: We evaluate the contribution of shocks to the excitation of CO around forming stars. The SiO observations are compatible with a scenario where less than 4% of the pre-shock SiO belongs to the grain mantles. We infer outflow parameters: a mass of 1.8 × 10-2 M⊙ was measured in our beam, in which a momentum of 0.4 M⊙ km s-1 is dissipated, corresponding to an energy of 4.2 × 1043 erg. We analyse the energetics of the outflow species by species. Comparing our results with previous studies highlights their dependence on the method: H2 observations only are not sufficient to evaluate the mass of outflows.

  6. Irritable bowel syndrome: a mild disorder; purely symptomatic treatment.

    PubMed

    2009-04-01

    psychological disturbances have been proposed, including relaxation, biofeedback, hypnosis, and psychotherapy. The results of clinical trials are not convincing; (10) Oral products containing live bacteria, designed to change the equilibrium of intestinal flora, have been tested in 13 placebo-controlled trials, with inconsistent results. A few cases of septicaemia have been reported; (11) The six available trials of acupuncture (versus sham acupuncture) showed no more than a placebo effect; (12) In practice, patients who have recurrent irritable bowel syndrome but with no other signs of a condition warranting specific treatment should be reassured as to the harmless nature of their disorder if a careful physical examination and basic laboratory tests are negative. The only available treatments have purely symptomatic effects and only limited efficacy. It is best to avoid using all treatments and additional diagnostic investigations that carry a risk of disproportionate adverse effects. PMID:19585728

  7. Al Shanker Remembers.

    ERIC Educational Resources Information Center

    American Educator, 2000

    2000-01-01

    In a 1996 interview shortly before his death, Al Shanker, longtime president of the American Federation of Teachers, discussed such topics as: his own educational experiences; how he learned about political fighting in the Boy Scouts; the appeal of socialism; multinational corporations and the nation state; teaching tough students; and John Dewey…

  8. Fosetyl-al

    Integrated Risk Information System (IRIS)

    Fosetyl - al ; CASRN 39148 - 24 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  9. ALS renewal moves forward

    NASA Astrophysics Data System (ADS)

    Falcone, R. W.; Feinberg, B.; Hussain, Z.; Kirz, J.; Krebs, G. F.; Padmore, H. A.; Robin, D. S.; Robinson, A. L.

    2007-11-01

    As the result of an extensive long-term planning process involving all its stakeholders—management, staff, and users—the ALS has seen its future and is aggressively moving ahead to implement its vision for keeping the facility at the cutting edge for the next 2-3 decades. The evolving strategic plan now in place aims to renew the ALS so it can address a new generation of fundamental questions about size dependent and dimensional-confinement phenomena at the nanoscale; correlation and complexity in physical, biological, and environmental systems; and temporal evolution, assembly, dynamics and ultrafast phenomena. The renewal spans three areas: (1) increased staffing at beamlines to support the growing user community and safety professionals to keep an increasingly complex facility hazard free; (2) implementing advances in accelerator, insertion device, beamline, and detector technology that will make it possible for ALS users to address emerging grand scientific and technological challenges with incisive world-class tools; and (3) construction of a user support building and guest housing that will increase the safety and user friendliness of the ALS by providing users office, meeting, experiment staging, and laboratory space for their work and on-site accommodations at reasonable rates.

  10. Formation Mechanism of CuAlO2 Prepared by Rapid Thermal Annealing of Al2O3/Cu2O/Sapphire Sandwich Structure

    NASA Astrophysics Data System (ADS)

    Shih, C. H.; Tseng, B. H.

    Single-phase CuAlO2 films were successfully prepared by thin-film reaction of an Al2O3/Cu2O/sapphire sandwich structure. We found that the processing parameters, such as heating rate, holding temperature and annealing ambient, were all crucial to form CuAlO2 without second phases. Thermal annealing in pure oxygen ambient with a lower temperature ramp rate might result in the formation of CuAl2O4 in addition to CuAlO2, since part of Cu2O was oxidized to form CuO and caused the change in reaction path, i.e. CuO + Al2O3 → CuAl2O4. Typical annealing conditions successful to prepare single-phase CuAlO2 would be to heat the sample with a temperature rampt rate higher than 7.3 °C/sec and hold the temperature at 1100 °C in air ambient. The formation mechanism of CuAlO2 has also been studied by interrupting the reaction after a short period of annealing. TEM observations showed that the top Al2O3 layer with amorphous structure reacted immediately with Cu2O to form CuAlO2 in the early stage and then the remaining Cu2O reacted with the sapphire substrate.

  11. A Picture-perfect Pure-disc Galaxy

    NASA Astrophysics Data System (ADS)

    2011-02-01

    The bright galaxy NGC 3621, captured here using the Wide Field Imager on the 2.2-metre telescope at ESO's La Silla Observatory in Chile, appears to be a fine example of a classical spiral. But it is in fact rather unusual: it does not have a central bulge and is therefore described as a pure-disc galaxy. NGC 3621 is a spiral galaxy about 22 million light-years away in the constellation of Hydra (The Sea Snake). It is comparatively bright and can be seen well in moderate-sized telescopes. This picture was taken using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. The data were selected from the ESO archive by Joe DePasquale as part of the Hidden Treasures competition [1]. Joe's picture of NGC 3621 was ranked fifth in the competition. This galaxy has a flat pancake shape, indicating that it hasn't yet come face to face with another galaxy as such a galactic collision would have disturbed the thin disc of stars, creating a small bulge in its centre. Most astronomers think that galaxies grow by merging with other galaxies, in a process called hierarchical galaxy formation. Over time, this should create large bulges in the centres of spirals. Recent research, however, has suggested that bulgeless, or pure-disc, spiral galaxies like NGC 3621 are actually fairly common. This galaxy is of further interest to astronomers because its relative proximity allows them to study a wide range of astronomical objects within it, including stellar nurseries, dust clouds, and pulsating stars called Cepheid variables, which astronomers use as distance markers in the Universe [2]. In the late 1990s, NGC 3621 was one of 18 galaxies selected for a Key Project of the Hubble Space Telescope: to observe Cepheid variables and measure the rate of expansion of the Universe to a higher accuracy than had been possible before. In the successful project, 69 Cepheid variables were observed in this galaxy alone. Multiple monochrome images taken through

  12. A Picture-perfect Pure-disc Galaxy

    NASA Astrophysics Data System (ADS)

    2011-02-01

    The bright galaxy NGC 3621, captured here using the Wide Field Imager on the 2.2-metre telescope at ESO's La Silla Observatory in Chile, appears to be a fine example of a classical spiral. But it is in fact rather unusual: it does not have a central bulge and is therefore described as a pure-disc galaxy. NGC 3621 is a spiral galaxy about 22 million light-years away in the constellation of Hydra (The Sea Snake). It is comparatively bright and can be seen well in moderate-sized telescopes. This picture was taken using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. The data were selected from the ESO archive by Joe DePasquale as part of the Hidden Treasures competition [1]. Joe's picture of NGC 3621 was ranked fifth in the competition. This galaxy has a flat pancake shape, indicating that it hasn't yet come face to face with another galaxy as such a galactic collision would have disturbed the thin disc of stars, creating a small bulge in its centre. Most astronomers think that galaxies grow by merging with other galaxies, in a process called hierarchical galaxy formation. Over time, this should create large bulges in the centres of spirals. Recent research, however, has suggested that bulgeless, or pure-disc, spiral galaxies like NGC 3621 are actually fairly common. This galaxy is of further interest to astronomers because its relative proximity allows them to study a wide range of astronomical objects within it, including stellar nurseries, dust clouds, and pulsating stars called Cepheid variables, which astronomers use as distance markers in the Universe [2]. In the late 1990s, NGC 3621 was one of 18 galaxies selected for a Key Project of the Hubble Space Telescope: to observe Cepheid variables and measure the rate of expansion of the Universe to a higher accuracy than had been possible before. In the successful project, 69 Cepheid variables were observed in this galaxy alone. Multiple monochrome images taken through

  13. Humification Processes of Different Pure Organic Sunstances in the Soil

    NASA Astrophysics Data System (ADS)

    Alianiello, F.; Mascia, M. G.; Valentini, M.; Cozzolino, S.

    2009-04-01

    The chemical composition and the structure of humic substances are not yet well known, due to the heterogeneity of their components. Different models have been proposed on their composition, but many doubts still exist on their chemical characteristics and their general structure. Different theories have been suggested also on the origins of humic substances and on the humification processes, and no one of them has been still universally accepted. Experimental results hardly can be generalised, since differences of soils, of the organic materials added to soil and of climate conditions provide heterogeneous results. Aim of this study was to follow the changes occurring to the chemical composition of organic substances added to soil and incubated under controlled conditions in a laboratory experiment, tracking the effects occurring to singular pure compounds, representative of the most abundant classes of compounds present in the organic matter. 4 pure compounds were added to two different soils and incubated for an year under controlled conditions of temperature and moisture (27°C, 2.5 pF). They were: lignin, cellulose, casein and tripalmitin. Lignin was chosen because it has been considered for long time the precursor of humic substances, while the others represent the most abundant classes of natural organic substances, i.e. proteins, carbohydrates and lipids. The material was added in the quantity necessary to double the organic C already present in the soil. Sub-samples were collected immediately after mixing, after 3 weeks, 3 months, 6 months and 1 year. The organic matter of the samples has been characterised by determination of total organic carbon, total extractable carbon, humic plus fulvic acids and calculation of humification parameters. Soil microbial biomass was determined immediately after sampling. Total organic carbon decreased in all the treated soils, as expected, but differences were detected among the different mixtures. Casein seemed to be

  14. Enthalpies of formation of CaAl4O7 and CaAl12O19 (hibonite) by high temperature, alkali borate solution calorimetry

    NASA Technical Reports Server (NTRS)

    Geiger, C. A.; Kleppa, O. J.; Grossman, L.; Mysen, B. O.; Lattimer, J. M.

    1988-01-01

    Enthalpies of formation were determined for two calcium aluminate phases, CaAl4O7 and CaAl12O19, using high-temperature alkali borate solution calorimetry. The aluminates were synthesized by multiple-cycle heating and grinding stoichiometric mixtures of CaCO3 and Al2O3, and the products were characteized by X-ray diffraction and SEM microbeam analysis. The data on impurities (CaAl4O7 was found to be about 89.00 percent pure by weight and the CaAl12O19 samples about 91.48 percent pure) were used to correct the heat of solution values of the synthetic products. The enthalpies of formation, at 1063 K, from oxides, were found to be equal to -(25.6 + or - 4.7) kJ/g.f.w. for CaAl4O7 and -(33.0 + or - 9.7) kJ/g.f.w. for CaAl12O19; the respective standard enthalpies of formation from elements, at 298 K, were estimated to be -4007 + or - 5.2 kJ/g.f.w. and -10,722 + or - 12 kJ/g.f.w.

  15. Bone mesenchymal stem cell functions on the hierarchical micro/nanotopographies of the Ti-6Al-7Nb alloy.

    PubMed

    Ren, Nan; Zhang, Shuyin; Li, Yongfeng; Shen, Shuning; Niu, Qiang; Zhao, Yimin; Kong, Liang

    2014-12-01

    We investigated the response of rat bone mesenchymal stem cells (BMSC) placed on the titanium-6aluminium-7niobiuim (Ti-6Al-7Nb) alloy modified by hydrofluoric acid etch combined with subsequent anodic oxidation. Pure titanium (Ti) discs and Ti-6Al-7Nb discs were treated by hydrofluoric acid etch and anodic oxidation, and polished pure Ti discs and Ti-6Al-7Nb discs without surface modification served as controls (n=35 in each group). Scanning electron microscopy, atomic force microscopy, and radiographic photoelectron spectroscopy assays were used to detect the properties of the samples' surface. The morphology, adhesion, proliferation, and alkaline phosphatase activity of BMSC were examined using various techniques of microscopic and biological characterisation. The results showed that both Ti-6Al-7Nb samples and the pure Ti samples showed hierarchical micro/nanotopographies, and fluorine emerged on the surfaces of the samples after modification. The hierarchical micro/nanotopographies significantly increased the spreading, adhesion, and proliferation of BMSC and activity of alkaline phosphatase. In addition, modified samples of Ti-6Al-7Nb showed significantly higher alkaline phosphatase activity than modified pure Ti samples (p<0.05). The experiment successfully confirmed that Ti-6Al-7Nb alloy with hierarchical micro/nanotopographies treated by hydrofluoric acid etch and anodic oxidation possessed good biocompatibility, and may be a promising candidate for dental implants.

  16. Paleoclimates on Titan: the case of a pure nitrogen atmosphere

    NASA Astrophysics Data System (ADS)

    Charnay, Benjamin; Forget, Francois; Tobie, Gabriel; Sotin, Christophe; Wordsworth, Robin

    2016-06-01

    Several clues indicate that Titan's atmosphere has been depleted in methane during some period of its history, possibly as recently as 0.5-1 billion years ago. It could also happen in the future. Under these conditions, the atmosphere becomes only composed of nitrogen with a range of temperature and pressure allowing liquid or solid nitrogen to condense. We explored these exotic climates throughout Titan's history with a 3D Global Climate Model (GCM) including the nitrogen cycle and the radiative effect of nitrogen clouds (Charnay et al. 2014). We found that for the last billion years, only small polar nitrogen lakes should have formed. Yet, before 1 Ga, a significant part of the atmosphere could have condensed, forming deep nitrogen polar seas, which could have flowed and flooded the equatorial regions. During this talk, I will present our results and discuss the possible implications for the erosion and the age of Titan's surface, for the flattening of the polar regions and for the methane outgassing on Titan.

  17. Relatively uniform and accelerated degradation of pure iron coated with micro-patterned Au disc arrays.

    PubMed

    Cheng, J; Huang, T; Zheng, Y F

    2015-03-01

    Pure iron has been proven to be a potential biodegradable metal, but its degradation rate was too slow. To accelerate its biodegradation, micro-patterned Au disc films were deposited on the surface of pure iron by vacuum sputtering. The influence of Au disc films on the degradation of pure iron matrix in vitro was investigated in the present study. Electrochemical measurement results indicated that the corrosion current density of pure iron coated with micro-patterned Au disc films in Hank's solution was 4 times larger than that of the uncoated one, while the difference between the influences of micro-patterned Au discs with different diameters on the corrosion rate of pure iron was insignificant. Immersion test indicated that the corrosion depth for pure iron coated with Au disc films was about three times as that of bare pure iron. Both electrochemical test and immersion test revealed that the corrosion of pure iron matrix coated with Au disc array became more uniform.

  18. Children's Phonatory Matching of Pure-Tone and Human Voice Stimulus.

    ERIC Educational Resources Information Center

    Schneiderman, Carl R.; Somerville, Elizabeth C.

    1983-01-01

    Thirty-six children (six to nine years old) were tested for their ability to vocally match both human voice and pure-tone stimuli. Results indicated that children are better able to match audiotape recordings of trained human voices modeling a wide range of calibrated frequencies than pure tones generated by an audio-oscillator. (Author/CL)

  19. What lies beneath: a comparison of reading aloud in pure alexia and semantic dementia.

    PubMed

    Woollams, Anna M; Hoffman, Paul; Roberts, Daniel J; Lambon Ralph, Matthew A; Patterson, Karalyn E

    2014-01-01

    Exaggerated effects of word length upon reading-aloud performance define pure alexia, but have also been observed in semantic dementia. Some researchers have proposed a reading-specific account, whereby performance in these two disorders reflects the same cause: impaired orthographic processing. In contrast, according to the primary systems view of acquired reading disorders, pure alexia results from a basic visual processing deficit, whereas degraded semantic knowledge undermines reading performance in semantic dementia. To explore the source of reading deficits in these two disorders, we compared the reading performance of 10 pure alexic and 10 semantic dementia patients, matched in terms of overall severity of reading deficit. The results revealed comparable frequency effects on reading accuracy, but weaker effects of regularity in pure alexia than in semantic dementia. Analysis of error types revealed a higher rate of letter-based errors and a lower rate of regularization responses in pure alexia than in semantic dementia. Error responses were most often words in pure alexia but most often nonwords in semantic dementia. Although all patients made some letter substitution errors, these were characterized by visual similarity in pure alexia and phonological similarity in semantic dementia. Overall, the data indicate that the reading deficits in pure alexia and semantic dementia arise from impairments of visual processing and knowledge of word meaning, respectively. The locus and mechanisms of these impairments are placed within the context of current connectionist models of reading.

  20. 77 FR 5049 - Pure Magnesium From China; Institution of a Five-Year Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ... duty order on imports of pure magnesium in granular form from China (66 FR 57936). Following expedited... continuation of the antidumping duty order on imports of pure magnesium in granular form from China (72 FR 5417..., subparts A, D, E, and F (19 CFR part 207), as most recently amended at 74 FR 2847 (January 16, 2009)....