Sample records for super spectral viscosity

  1. Chebyshev super spectral viscosity method for water hammer analysis

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    Hongyu Chen


    Full Text Available In this paper, a new fast and efficient algorithm, Chebyshev super spectral viscosity (SSV method, is introduced to solve the water hammer equations. Compared with standard spectral method, the method's advantage essentially consists in adding a super spectral viscosity to the equations for the high wave numbers of the numerical solution. It can stabilize the numerical oscillation (Gibbs phenomenon and improve the computational efficiency while discontinuities appear in the solution. Results obtained from the Chebyshev super spectral viscosity method exhibit greater consistency with conventional water hammer calculations. It shows that this new numerical method offers an alternative way to investigate the behavior of the water hammer in propellant pipelines.

  2. Chebyshev super spectral viscosity method for a fluidized bed model

    CERN Document Server

    Sarra, S A


    A Chebyshev super spectral viscosity method and operator splitting are used to solve a hyperbolic system of conservation laws with a source term modeling a fluidized bed. The fluidized bed displays a slugging behavior which corresponds to shocks in the solution. A modified Gegenbauer postprocessing procedure is used to obtain a solution which is free of oscillations caused by the Gibbs-Wilbraham phenomenon in the spectral viscosity solution. Conservation is maintained by working with unphysical negative particle concentrations.


    Energy Technology Data Exchange (ETDEWEB)

    Stamenkovic, Vlada; Noack, Lena; Spohn, Tilman [Institute of Planetology, Westfaelische Wilhelms-Universitaet Muenster, Wilhelm-Klemm-Str. 10, 48149 Muenster (Germany); Breuer, Doris, E-mail:, E-mail:, E-mail:, E-mail: [Institute of Planetary Research, German Aerospace Center DLR, Rutherfordstrasse 2, 12489 Berlin (Germany)


    We study the thermal evolution of super-Earths with a one-dimensional (1D) parameterized convection model that has been adopted to account for a strong pressure dependence of the viscosity. A comparison with a 2D spherical convection model shows that the derived parameterization satisfactorily represents the main characteristics of the thermal evolution of massive rocky planets. We find that the pressure dependence of the viscosity strongly influences the thermal evolution of super-Earths-resulting in a highly sluggish convection regime in the lower mantles of those planets. Depending on the effective activation volume and for cooler initial conditions, we observe with growing planetary mass even the formation of a conductive lid above the core-mantle boundary (CMB), a so-called CMB-lid. For initially molten planets our results suggest no CMB-lids but instead a hot lower mantle and core as well as sluggish lower mantle convection. This implies that the initial interior temperatures, especially in the lower mantle, become crucial for the thermal evolution-the thermostat effect suggested to regulate the interior temperatures in terrestrial planets does not work for massive planets if the viscosity is strongly pressure dependent. The sluggish convection and the potential formation of the CMB-lid reduce the convective vigor throughout the mantle, thereby affecting convective stresses, lithospheric thicknesses, and heat fluxes. The pressure dependence of the viscosity may therefore also strongly affect the propensity of plate tectonics, volcanic activity, and the generation of a magnetic field of super-Earths.

  4. Super-resolution Spectral Reconstruction for DWDM Channel Monitoring

    DEFF Research Database (Denmark)

    Piels, Molly; Zibar, Darko


    We demonstrate a super-resolution algorithm to estimate channel power and spacing. We show minimal loss in power accuracy and frequency accuracy 1000x below the spectrometer resolution.......We demonstrate a super-resolution algorithm to estimate channel power and spacing. We show minimal loss in power accuracy and frequency accuracy 1000x below the spectrometer resolution....

  5. Spectral width of SuperDARN echoes: measurement, use and physical interpretation

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    P. V. Ponomarenko


    Full Text Available The Doppler velocity and spectral width are two important parameters derived from coherent scatter radar systems. The Super Dual Auroral Radar Network (SuperDARN is capable of monitoring most of the high latitude region where different boundaries of the magnetosphere map to the ionosphere. In the past, the spectral width, calculated from SuperDARN data, has been used to identify the ionosphere footprints of various magnetosphere boundaries. In this paper we examine the way the spectral width is presently estimated from the radar data and describe several recommendations for improving the algorithm. Using the improved algorithm, we show that typical spectral width values reported in the literature are most probably overestimated. The physical interpretation of the cause of various magnitudes of the spectral width is explored in terms of the diffusion and dynamics of ionospheric plasma irregularities.

  6. Explicit discontinuous spectral element method with entropy generation based artificial viscosity for shocked viscous flows (United States)

    Chaudhuri, A.; Jacobs, G. B.; Don, W. S.; Abbassi, H.; Mashayek, F.


    A spatio-temporal adaptive artificial viscosity (AV) based shock-capturing scheme is proposed for the solution of both inviscid and viscous compressible flows using a high-order parallel Discontinuous Spectral Element Method (DSEM). The artificial viscosity and artificial thermal conduction coefficients are proportional to the viscous and thermal entropy generating terms, respectively, in the viscous entropy conservation law. The magnitude of AV is limited based on the explicit stable CFL criterion, so that the stable artificial viscous time step size is greater than the convective stable time step size. To further ensure the stability of this explicit approach, an adaptive variable order exponential filter is applied, if necessary, in elements where the AV has been limited. In viscous flow computations a modified Jameson's sensor (Ducros et al., 1999 [61]) limits the AV to small values in viscous shear regions, so as to maintain a high-order resolution in smooth regions and an essentially non-oscillatory behavior near sharp gradients/shocks regions. We have performed a systematic and extensive validation of the algorithm with one-dimensional problems (inviscid moving shock and viscous shock-structure interaction), two-dimensional problems (inviscid steady and unsteady shocked flows and viscous shock-boundary layer interaction), and a three-dimensional supersonic turbulent flow over a ramped cavity. These examples demonstrate that the explicit DSEM scheme with adaptive artificial viscosity terms is stable, accurate and efficient.

  7. Numerical experiments on thermal convection of highly compressible fluids with variable viscosity and thermal conductivity: Implications for mantle convection of super-Earths (United States)

    Kameyama, Masanori; Yamamoto, Mayumi


    We conduct a series of numerical experiments of thermal convection of highly compressible fluids in a two-dimensional rectangular box, in order to study the mantle convection on super-Earths. The thermal conductivity and viscosity are assumed to exponentially depend on depth and temperature, respectively, while the variations in thermodynamic properties (thermal expansivity and reference density) with depth are taken to be relevant for the super-Earths with 10 times the Earth's. From our experiments we identified a distinct regime of convecting flow patterns induced by the interplay between the adiabatic temperature change and the spatial variations in viscosity and thermal conductivity. That is, for the cases with strong temperature-dependent viscosity and depth-dependent thermal conductivity, a "deep stratosphere" of stable thermal stratification is formed at the base of the mantle, in addition to thick stagnant lids at their top surfaces. In the "deep stratosphere", the fluid motion is insignificant particularly in the vertical direction in spite of smallest viscosity owing to its strong dependence on temperature. Our finding may further imply that some of super-Earths which are lacking in mobile tectonic plates on their top surfaces may have "deep stratospheres" at the base of their mantles.

  8. Design of Super Narrowband DWDM Filters Based on the Effect of Spectral Splitting

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C Q; Chen, M [College of Physics and Electronics, Hunan Institute of Science and Technology, Yueyang 414006 (China); Liu, J; Wan, Z M; Luo, Z M [College of Information and Communication Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Tian, P, E-mail: [College of Optoelectronic Science and Engineering, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074 (China)


    A novel approach is proposed to design super narrowband DWDM Filters consisting of multiple quantum wells (MQWs) by employing photonic crystals. Numerical investigations prove that the closed-cavity MQWs are more suitable for DWDM systems compared with the open-cavity MQWs. It is shown that different confined states could emerge from photonic band gap, which can be used as high-frequency carriers one-to-one. It is also found that these proposed MQWs could split the single spectral lines into multiples based on the effect of spectral splitting, and the number of the splitting is just equal to the number of the wells. In this way, the density of carriers can be increased multiplicatively in the same wave band, and thus the spectral efficiency can be improved multiplicatively. These results provide the prospects of channel density maximization and effective bandwidth optimization for optical communication.

  9. A Parameter-Free Dynamic Alternative to Hyper-Viscosity for Coupled Transport Equations: Application to the Simulation of 3D Squall Lines Using Spectral Elements (United States)


    Viscosity for Coupled Transport Equations: Application to the Simulation of 3D Squall Lines Using Spectral Elements 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...the results against those obtained with a fourth-order hyper- viscosity programmed in the same code. The main conclusion that arises is that tuning...second order operator which means that fewer communications are required by VMS+DC than by a hyper- viscosity method fewer communications translate into

  10. Compressive spectral image super-resolution by using singular value decomposition (United States)

    Marquez, M.; Mejia, Y.; Arguello, Henry


    Compressive sensing (CS) has been recently applied to the acquisition and reconstruction of spectral images (SI). This field is known as compressive spectral imaging (CSI). The attainable resolution of SI depends on the sensor characteristics, whose cost increases in proportion to the resolution. Super-resolution (SR) approaches are usually applied to low-resolution (LR) CSI systems to improve the quality of the reconstructions by solving two consecutive optimization problems. In contrast, this work aims at reconstructing a high resolution (HR) SI from LR compressive measurements by solving a single convex optimization problem based on the fusion of CS and SR techniques. Furthermore, the truncated singular value decomposition is used to alleviate the computational complexity of the inverse reconstruction problem. The proposed method is tested by using the coded aperture snapshot spectral imager (CASSI), and the results are compared to HR-SI images directly reconstructed from LR-SI images by using an SR algorithm via sparse representation. In particular, a gain of up to 1.5 dB of PSNR is attained with the proposed method.

  11. Spectrally Resolved and Functional Super-resolution Microscopy via Ultrahigh-Throughput Single-Molecule Spectroscopy. (United States)

    Yan, Rui; Moon, Seonah; Kenny, Samuel J; Xu, Ke


    As an elegant integration of the spatial and temporal dimensions of single-molecule fluorescence, single-molecule localization microscopy (SMLM) overcomes the diffraction-limited resolution barrier of optical microscopy by localizing single molecules that stochastically switch between fluorescent and dark states over time. While this type of super-resolution microscopy (SRM) technique readily achieves remarkable spatial resolutions of ∼10 nm, it typically provides no spectral information. Meanwhile, current scanning-based single-location approaches for mapping the positions and spectra of single molecules are limited by low throughput and are difficult to apply to densely labeled (bio)samples. In this Account, we summarize the rationale, design, and results of our recent efforts toward the integration of the spectral dimension of single-molecule fluorescence with SMLM to achieve spectrally resolved SMLM (SR-SMLM) and functional SRM (f-SRM). By developing a wide-field scheme for spectral measurement and implementing single-molecule fluorescence on-off switching typical of SMLM, we first showed that in densely labeled (bio)samples it is possible to record the fluorescence spectra and positions of millions of single molecules synchronously within minutes, giving rise to ultrahigh-throughput single-molecule spectroscopy and SR-SMLM. This allowed us to first show statistically that for many dyes, single molecules of the same species exhibit near identical emission in fixed cells. This narrow distribution of emission wavelengths, which contrasts markedly with previous results at solid surfaces, allowed us to unambiguously identify single molecules of spectrally similar dyes. Crosstalk-free, multiplexed SRM was thus achieved for four dyes that were merely 10 nm apart in emission spectrum, with the three-dimensional SRM images of all four dyes being automatically aligned within one image channel. The ability to incorporate single-molecule fluorescence measurement with

  12. A Dynamic Eddy Viscosity Model for the Shallow Water Equations Solved by Spectral Element and Discontinuous Galerkin Methods (United States)

    Marras, Simone; Suckale, Jenny; Giraldo, Francis X.; Constantinescu, Emil


    We present the solution of the viscous shallow water equations where viscosity is built as a residual-based subgrid scale model originally designed for large eddy simulation of compressible [1] and stratified flows [2]. The necessity of viscosity for a shallow water model not only finds motivation from mathematical analysis [3], but is supported by physical reasoning as can be seen by an analysis of the energetics of the solution. We simulated the flow of an idealized wave as it hits a set of obstacles. The kinetic energy spectrum of this flow shows that, although the inviscid Galerkin solutions -by spectral elements and discontinuous Galerkin [4]- preserve numerical stability in spite of the spurious oscillations in the proximity of the wave fronts, the slope of the energy cascade deviates from the theoretically expected values. We show that only a sufficiently small amount of dynamically adaptive viscosity removes the unwanted high-frequency modes while preserving the overall sharpness of the solution. In addition, it yields a physically plausible energy decay. This work is motivated by a larger interest in the application of a shallow water model to the solution of tsunami triggered coastal flows. In particular, coastal flows in regions around the world where coastal parks made of mitigation hills of different sizes and configurations are considered as a means to deviate the power of the incoming wave. References [1] M. Nazarov and J. Hoffman (2013) "Residual-based artificial viscosity for simulation of turbulent compressible flow using adaptive finite element methods" Int. J. Numer. Methods Fluids, 71:339-357 [2] S. Marras, M. Nazarov, F. X. Giraldo (2015) "Stabilized high-order Galerkin methods based on a parameter-free dynamic SGS model for LES" J. Comput. Phys. 301:77-101 [3] J. F. Gerbeau and B. Perthame (2001) "Derivation of the viscous Saint-Venant system for laminar shallow water; numerical validation" Discrete Contin. Dyn. Syst. Ser. B, 1:89?102 [4] F

  13. Environmentally friendly synthesis of reducing super-heavy oil viscosity; Sintesis amigable con el ambiente de reductores de viscosidad para petroleos Super-pesados

    Energy Technology Data Exchange (ETDEWEB)

    Castro Sotelo, Laura Veronica [Instituto Politecnico Nacional, ESIQIE, Mexico, D.F. (Mexico)]. E-mail:; Flores Oropeza, Eugenio Alejandro [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)]. E-mail:; Hernandez Garcia, Arnulfo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail:; Vazquez Moreno, Flavio Salvador [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)]. E-mail:


    There are certain polymers that have the character to be flow modifiers, and this emerges of the chemical structure and molecular interaction that the polymers have with the crude oil. Three polymers were prepared by emulsion polymerization were characterized, they were characterized by Fourier transform infrared (FTIR) spectroscopy and Size exclusion Size exclusion chromatography (SEC). To assess its implementation, the polymers were evaluated in heavy crude oils with rotational tests. The polymer concentration was evaluated at 1000 ppm, and it presented an appreciable reduction of viscosity in heavy crude oil. [Spanish] Existen ciertos polimeros que tienen el caracter de ser modificadores de flujo, y esto surge de la estructura quimica y las interacciones moleculares que presentan estos al contacto con el aceite crudo. Se sintetizaron tres polimeros a traves de la tecnica de polimerizacion en emulsion, los polimeros fueron caracterizados por Espectroscopia Infrarroja con transformada de Fourier (FTIR), tambien se utilizo la tecnica de Cromatografia por Exclusion de Tamanos (SEC). Para valorar su aplicacion, se evaluaron en aceites crudos pesados con pruebas rotacionales. La concentracion de los polimeros se valuo en 1000 ppm, y se aprecio un notable abatimiento de la viscosidad del aceite crudo pesado.

  14. Energy transfers and spectral eddy viscosity in large-eddy simulations of homogeneous isotropic turbulence : Comparison of dynamic Smagorinsky and multiscale models over a range of discretizations

    NARCIS (Netherlands)

    Hughes, T.J.R.; Wells, G.N.; Wray, A.A.


    Energy transfers within large-eddy simulation (LES) and direct numerical simulation (DNS) grids are studied. The spectral eddy viscosity for conventional dynamic Smagorinsky and variational multiscale LES methods are compared with DNS results. Both models underestimate the DNS results for a very

  15. An analysis of artificial viscosity effects on reacting flows using a spectral multi-domain technique (United States)

    Macaraeg, Michele G.; Streett, Craig L.


    Analytical and experimental techniques for modeling the aerothermodynamics of hypersonic flight are assessed, together with the problems which will be encountered in developing reusable hypersonic vehicles. Emphasis is placed on a numerical coupling between a nonequilibrium chemistry model and hypersonic flow kinematics. Finite difference and finite element descriptions of flow fields in which molecules encounter a shock wave and undergo various motion (and thereby energy) transformations are discussed. The effects of artificial smearing of the shock wave are considered in terms of the resulting effects on the distribution of the energies and chemical composition of the transition region. Results are provided from schlieren photographs of shock-tube experiments, Navier-Stokes calculations of axisymmetric flow over a conical body, and calculations using a spectral multidomain approach for chemically reacting flows.

  16. An investigation of latitudinal transitions in the SuperDARN Doppler spectral width parameter at different magnetic local times

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    G. Chisham


    Full Text Available Latitudinal transitions from low to high Doppler spectral width in backscatter measured by the Super Dual Auroral Radar Network (SuperDARN are now routinely used as proxies for the polar cap boundary (PCB in the cusp-region ionosphere. In this paper we perform a statistical study of the nature of similar spectral width transitions at other magnetic local times (MLTs. This analysis illustrates that these latitudinal spectral width transitions exist at all magnetic local times, and that the latitude, gradient, and amplitude of the transitions vary systematically with MLT. In particular, the probability of a transition occurring at any latitude, identified independently in each MLT sector, is continuous with MLT from the cusp, through the morning sector, to the nightside. This suggests that the transition represents the PCB, as this is known to be what it represents in the cusp region. However, the picture in the afternoon sector (12:00-18:00 MLT is more complex with no clearly preferred transition latitudes. Key words. Ionosphere (ionosphere-magnetosphere interactions; instruments and techniques. Magnetospheric physics (magnetopause, cusp, and boundary layers.

  17. Magnetic local time, substorm, and particle precipitation-related variations in the behaviour of SuperDARN Doppler spectral widths

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    M. L. Parkinson


    Full Text Available Super Dual Auroral Radar Network (DARN radars often detect a distinct transition in line-of-sight Doppler velocity spread, or spectral width, from <50ms–1 at lower latitude to >200ms–1 at higher latitude. They also detect a similar boundary, namely the range at which ionospheric scatter with large spectral width suddenly commences (i.e. without preceding scatter with low spectral width. The location and behaviour of the spectral width boundary (SWB (and scatter boundary and the open-closed magnetic field line boundary (OCB are thought to be closely related. The location of the nightside OCB can be inferred from the poleward edge of the auroral oval determined using energy spectra of precipitating particles measured on board Defence Meteorology Satellite Program (DMSP satellites. Observations made with the Halley SuperDARN radar (75.5° S, 26.6° W, geographic; –62.0°Λ and the Tasman International Geospace Environment Radar (TIGER (43.4° S, 147.2° E; –54.5°Λ are used to compare the location of the SWB with the DMSP-inferred OCB during 08:00 to 22:00 UT on 1 April 2000. This study interval was chosen because it includes several moderate substorms, whilst the Halley radar provided almost continuous high-time resolution measurements of the dayside SWB location and shape, and TIGER provided the same in the nightside ionosphere. The behaviour of the day- and nightside SWB can be understood in terms of the expanding/contracting polar cap model of high-latitude convection change, and the behaviour of the nightside SWB can also be organised according to substorm phase. Previous comparisons with DMSP OCBs have proven that the radar SWB is often a reasonable proxy for the OCB from dusk to just past midnight (Chisham et al., 2004. However, the present case study actually suggests that the nightside SWB is often a better proxy for the poleward edge of Pedersen conductance enhanced by hot particle precipitation in the auroral zone. Simple

  18. A statistical comparison of SuperDARN spectral width boundaries and DMSP particle precipitation boundaries in the morning sector ionosphere

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    G. Chisham


    Full Text Available Determining reliable proxies for the ionospheric signature of the open-closed field line boundary (OCB is crucial for making accurate ionospheric measurements of many magnetospheric processes (e.g. magnetic reconnection. This study compares the latitudes of Spectral Width Boundaries (SWBs, identified in the morning sector ionosphere using the Super Dual Auroral Radar Network (SuperDARN, with Particle Precipitation Boundaries (PPBs determined using the low-altitude Defense Meteorological Satellite Program (DMSP spacecraft, in order to determine whether the SWB represents a good proxy for the ionospheric projection of the OCB. The latitudes of SWBs and PPBs were identified using automated algorithms applied to 5 years (1997-2001 of data measured in the 00:00-12:00 Magnetic Local Time (MLT range. A latitudinal difference was measured between each PPB and the nearest SWB within a ±10min Universal Time (UT window and within a ±1h MLT window. The results show that the SWB represents a good proxy for the OCB close to midnight (~00:00-02:00 MLT and noon (~08:00-12:00 MLT, but is located some distance (~2°-4° equatorward of the OCB across much of the morning sector ionosphere (~02:00-08:00 MLT. On the basis of this and other studies we deduce that the SWB is correlated with the poleward boundary of auroral emissions in the Lyman-Birge-Hopfield ``Long" (LBHL UV emission range and hence, that spectral width is inversely correlated with the energy flux of precipitating electrons. We further conclude that the combination of two factors may explain the spatial distribution of spectral width values in the polar ionospheres. The small-scale structure of the convection electric field leads to an enhancement in spectral width in regions close to the OCB, whereas increases in ionospheric conductivity (relating to the level of incident electron energy flux lead to a reduction in spectral width in regions just equatorward of the OCB.

  19. A statistical comparison of SuperDARN spectral width boundaries and DMSP particle precipitation boundaries in the afternoon sector ionosphere

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    G. Chisham


    Full Text Available The open-closed magnetic field line boundary (OCB is best measured at the foot points of the boundary in the Earth's ionosphere where continuous and extensive spatiotemporal measurements can be made. The ability to make routine observations of this type is crucial if accurate global measurements of energy transfer processes occurring at the boundary, such as magnetic reconnection, are to become a reality. The spectral width boundary (SWB measured by the Super Dual Auroral Radar Network (SuperDARN has been shown to be a reliable ionospheric proxy for the OCB at certain magnetic local times (MLTs. However, the reliability of the SWB proxy in the afternoon sector ionosphere (12:00-18:00 MLT has been questionable. In this paper we undertake a statistical comparison of the latitudinal locations of SWBs measured by SuperDARN and particle precipitation boundaries (PPBs measured by the Defense Meteorological Satellite Program (DMSP spacecraft, concentrating on the PPB which best approximates the location of the OCB. The latitudes of SWBs and PPBs were identified using automated algorithms applied to 5 years (1997-2001 of data measured in the 12:00-18:00 MLT range. A latitudinal difference was measured between each PPB and the nearest SWB within a ±10 min universal time (UT window and within a ±1 h MLT window. The results show that when the SWB is identified at higher geomagnetic latitudes (poleward of ~74, it is a good proxy for the OCB, with 76% of SWBs lying within 3 of the OCB. At lower geomagnetic latitudes (equatorward of ~74, the correlation is poor and the results suggest that most of the SWBs being identified represent ionospheric variations unassociated with the OCB, with only 32% of SWBs lying within 3 of the OCB. We propose that the low level of precipitating electron energy flux, typical of latitudes well equatorward of the OCB in the afternoon sector, may be a factor in enhancing spectral width values at these lower latitudes. A

  20. Statistical characteristics of Doppler spectral width as observed by the conjugate SuperDARN radars

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    K. Hosokawa

    Full Text Available We performed a statistical analysis of the occurrence distribution of Doppler spectral width around the day-side high-latitude ionosphere using data from the conjugate radar pair composed of the CUTLASS Iceland-East radar in the Northern Hemisphere and the SENSU Syowa-East radar in the Southern Hemisphere. Three types of spectral width distribution were identified: (1 an exponential-like distribution in the lower magnetic latitudes (below 72°, (2 a Gaussian-like distribution around a few degrees magnetic latitude, centered on 78°, and (3 another type of distribution in the higher magnetic latitudes (above 80°. The first two are considered to represent the geophysical regimes such as the LLBL and the cusp, respectively, because they are similar to the spectral width distributions within the LLBL and the cusp, as classified by Baker et al. (1995. The distribution found above 80° magnetic latitude has been clarified for the first time in this study. This distribution has similarities to the exponential-like distribution in the lower latitude part, although clear differences also exist in their characteristics. These three spectral width distributions are commonly identified in conjugate hemispheres. The latitudinal transition from one distribution to another exhibits basically the same trend between two hemispheres. There is, however, an interhemispheric difference in the form of the distribution around the cusp latitudes, such that spectral width values obtained from Syowa-East are larger than those from Iceland-East. On the basis of the spectral width characteristics, the average locations of the cusp and the open/closed field line boundary are estimated statistically.

    Key words. Ionosphere (ionosphere-magnetosphere inter-actions; plasma convection – Magnetospheric physics (magnetopause, cusp, and boundary layers

  1. Spectral estimation optical coherence tomography for axial super-resolution (Conference Presentation) (United States)

    Liu, Xinyu; Yu, Xiaojun; Wang, Nanshuo; Bo, En; Luo, Yuemei; Chen, Si; Cui, Dongyao; Liu, Linbo


    The sample depth reflectivity profile of Fourier domain optical coherence tomography (FD-OCT) is estimated from the inverse Fourier transform of the spectral interference signals (interferograms). As a result, the axial resolution is fundamentally limited by the coherence length of the light source. We demonstrate an axial resolution improvement method by using the autoregressive spectral estimation technique to instead of the inverse Fourier transform to analyze the spectral interferograms, which is named as spectral estimation OCT (SE-OCT). SE-OCT improves the axial resolution by a factor of up to 4.7 compared with the corresponding FD-OCT. Furthermore, SE-OCT provides a complete sidelobe suppression in the point-spread function. Using phantoms such as an air wedge and micro particles, we prove the ability of resolution improvement. To test SE-OCT for real biological tissue, we image the rat cornea and demonstrate that SE-OCT enables clear identification of corneal endothelium anatomical details ex vivo. We also find that the performance of SE-OCT is depended on SNR of the feature object. To evaluate the potential usage and define the application scope of SE-OCT, we further investigate the property of SNR dependence and the artifacts that may be caused. We find SE-OCT may be uniquely suited for viewing high SNR layer structures, such as the epithelium and endothelium in cornea, retina and aorta. Given that SE-OCT can be implemented in the FD-OCT devices easily, the new capabilities provided by SE-OCT are likely to offer immediate improvements to the diagnosis and management of diseases based on OCT imaging.

  2. A Statistical study of the Doppler spectral width of high-latitude ionospheric F-region echoes recorded with SuperDARN coherent HF radars

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    J.-P. Villain


    Full Text Available The HF radars of the Super Dual Auroral Radar Network (SuperDARN provide measurements of the E × B drift of ionospheric plasma over extended regions of the high-latitude ionosphere. We have conducted a statistical study of the associated Doppler spectral width of ionospheric F-region echoes. The study has been conducted with all available radars from the Northern Hemisphere for 2 specific periods of time. Period 1 corresponds to the winter months of 1994, while period 2 covers October 1996 to March 1997. The distributions of data points and average spectral width are presented as a function of Magnetic Latitude and Magnetic Local Time. The databases are very consistent and exhibit the same features. The most stringent features are: a region of very high spectral width, collocated with the ionospheric LLBL/cusp/mantle region; an oval shaped region of high spectral width, whose equator-ward boundary matches the poleward limit of the Holzworth and Meng auroral oval. A simulation has been conducted to evaluate the geometrical and instrumental effects on the spectral width. It shows that these effects cannot account for the observed spectral features. It is then concluded that these specific spectral width characteristics are the signature of ionospheric/magnetospheric coupling phenomena.Key words. Ionosphere (auroral ionosphere; ionosphere-magnetosphere interactions; ionospheric irregularities

  3. A Statistical study of the Doppler spectral width of high-latitude ionospheric F-region echoes recorded with SuperDARN coherent HF radars

    Directory of Open Access Journals (Sweden)

    J.-P. Villain

    Full Text Available The HF radars of the Super Dual Auroral Radar Network (SuperDARN provide measurements of the E × B drift of ionospheric plasma over extended regions of the high-latitude ionosphere. We have conducted a statistical study of the associated Doppler spectral width of ionospheric F-region echoes. The study has been conducted with all available radars from the Northern Hemisphere for 2 specific periods of time. Period 1 corresponds to the winter months of 1994, while period 2 covers October 1996 to March 1997. The distributions of data points and average spectral width are presented as a function of Magnetic Latitude and Magnetic Local Time. The databases are very consistent and exhibit the same features. The most stringent features are: a region of very high spectral width, collocated with the ionospheric LLBL/cusp/mantle region; an oval shaped region of high spectral width, whose equator-ward boundary matches the poleward limit of the Holzworth and Meng auroral oval. A simulation has been conducted to evaluate the geometrical and instrumental effects on the spectral width. It shows that these effects cannot account for the observed spectral features. It is then concluded that these specific spectral width characteristics are the signature of ionospheric/magnetospheric coupling phenomena.

    Key words. Ionosphere (auroral ionosphere; ionosphere-magnetosphere interactions; ionospheric irregularities

  4. Odd Viscosity


    Avron, J. E.


    When time reversal is broken the viscosity tensor can have a non vanishing odd part. In two dimensions, and only then, such odd viscosity is compatible with isotropy. Elementary and basic features of odd viscosity are examined by considering solutions of the wave and Navier-Stokes equations for hypothetical fluids where the stress is dominated by odd viscosity.

  5. Shear viscosity of the quark matter


    Iwasaki, Masaharu; Ohnishi, Hiromasa; Fukutome, Takahiko


    We discuss shear viscosity of the quark matter by using Kubo formula. The shear viscosity is calculated in the framework of the quasi-particle RPA for the Nambu-Jona-Lasinio model. We obtain a formula that the shear viscosity is expressed by the quadratic form of the quark spectral function in the chiral symmetric phase. The magnitude of the shear viscosity is discussed assuming the Breit-Wigner type for the spectral function.

  6. Viscosity Solution


    Camilli, Fabio; Prados, Emmanuel


    International audience; Viscosity solution is a notion of weak solution for a class of partial differential equations of Hamilton-Jacobi type. The range of applications of the notions of viscosity solution and Hamilton-Jacobi equations is enormous, including common class of partial differential equations such as evolutive problems and problems with boundary conditions, equations arising in optimal control theory, differential games, second-order equations arising in stochastic optimal control...

  7. Energy-Level Related Nuclear-Spin Effects and Super-Hyperfine Spectral Patterns: how Molecules do Self-Nmr (United States)

    Harter, William; Mitchell, Justin


    At several points in his defining works on molecular spectroscopy, Herzberg notes that ``because nuclear moments ldots are so very slight ldots transitions between species ldots are very strictly forbiddenldots '' Herzberg's most recent statement of such selection rules pertained to spherical top spin-species. It has since been shown that spherical top species (as well as those of lower symmetry molecules) converge exponentially with momentum quanta J and K to degenerate level clusters wherein even ``very slight'' nuclear fields and moments cause pervasive resonance and total spin species mixing. Ultra-high resolution spectra of Borde, et .al and Pfister et .al shows how SF_6 and SiF_4 Fluorine nuclear spin levels rearrange from total-spin multiplets to NMR-like patterns as their superfine structure converges. Similar super-hyperfine effects are anticipated for lower symmetry molecules exhibiting converging superfine level-clusters. Examples include PH_3 molecules and asymmetric tops. Following this we consider models that treat nuclear spins as coupled rotors undergoing generalized Hund-case transitions from spin-lab-momentum coupling to various spin-rotor correlations. G. A. Herzberg, Electronic Spectra of Polyatomic Molecules, (Von Norstrand Rheinhold 1966) p. 246. W G. Harter and C. W Patterson, Phys. Rev. A 19, 2277 (1979) W. G. Harter, Phys. Rev. A 24, 192 (1981). Ch. J. Borde, J. Borde, Ch. Breant, Ch. Chardonnet, A. Van Lerberghe, and Ch. Salomon, in Laser Spectroscopy VII, T. W Hensch and Y. R. Shen, eds. (Springer-Verlag, Berlin, 1985). O. Pfister, F. Guernet, G. Charton, Ch. Chardonnet, F. Herlemont, and J. Legrand, J. Opt. Soc. Am. B 10, 1521 (1993). O. Pfister, Ch. Chardonnet, and Ch. J. Bordè, Phys. Rev. Lett. 76, 4516 (1996) S. N. Yurchenko, W. Thiel, S. Patchkovskii, and P. Jensen, Phys. Chem. Chem. Phys.7, 573 (2005)

  8. From quantum cascade to super cascade laser a new laser design paradigm for broad spectral emission & a re-examination of current spreading (United States)

    Le, Loan T.

    Over the span of more than 20 years of development, the Quantum Cascade (QC) laser has positioned itself as the most viable mid-infrared (mid-IR) light source. Today's QC lasers emit watts of continuous wave power at room temperature. Despite significant progress, the mid-IR region remains vastly under-utilized. State-of-the-art QC lasers are found in high power defense applications and detection of trace gases with narrow absorption lines. A large number of applications, however, do not require so much power, but rather, a broadly tunable laser source to detect molecules with broad absorption features. As such, a QC laser that is broadly tunable over the entire biochemical fingerprinting region remains the missing link to markets such as non- invasive biomedical diagnostics, food safety, and stand-off detection in turbid media. In this thesis, we detail how we utilized the inherent flexibility of the QC design space to conceive a new type of laser with the potential to bridge that missing link of the QC laser to large commercial markets. Our design concept, the Super Cascade (SC) laser, works contrary to conventional laser design principle by supporting multiple independent optical transitions, each contributing to broadening the gain spectrum. We have demonstrated a room temperature laser gain medium with electroluminescence spanning 3.3-12.5 ?m and laser emission from 6.2-12.5 ?m, the record spectral width for any solid state laser gain medium. This gain bandwidth covers the entire biochemical fingerprinting region. The achievement of such a spectrally broad gain medium presents engineering challenges of how to optimally utilize the bandwidth. As of this work, a monolithi- cally integrated array of Distributed Feedback QC (DFB-QC) lasers is one of the most promising ways to fully utilize the SC gain bandwidth. Therefore, in this thesis, we explore ways of improving the yield and ease of fabrication of DFB-QC lasers, including a re-examination of the role of

  9. The accuracy of using the spectral width boundary measured in off-meridional SuperDARN HF radar beams as a proxy for the open-closed field line boundary

    Directory of Open Access Journals (Sweden)

    G. Chisham


    Full Text Available Determining reliable proxies for the ionospheric signature of the open-closed field line boundary (OCB is crucial for making accurate measurements of magnetic reconnection. This study compares the latitudes of spectral width boundaries (SWBs measured by different beams of the Goose Bay radar of the Super Dual Auroral Radar Network (SuperDARN, with the latitudes of OCBs determined using the low-altitude Defense Meteorological Satellite Program (DMSP spacecraft, in order to determine whether the accuracy of the SWB as a proxy for the ionospheric projection of the OCB depends on the line-of-sight direction of the radar beam. The latitudes of SWBs and OCBs were identified using automated algorithms applied to 5 years (1997–2001 of data measured in the 1000–1400 magnetic local time (MLT range. Six different Goose Bay radar beams were used, ranging from those aligned in the geomagnetic meridional direction to those aligned in an almost zonal direction. The results show that the SWB is a good proxy for the OCB in near-meridionally-aligned beams but becomes progressively more unreliable for beams greater than 4 beams away from the meridional direction. We propose that SWBs are identified at latitudes lower than the OCB in the off-meridional beams due to the presence of high spectral width values that result from changes in the orientation of the beams with respect to the gradient in the large-scale ionospheric convection pattern. Keywords. Ionosphere (Instruments and techniques; Plasma convection – Magnetospheric physics (Magnetopause, cusp and boundary layers

  10. Viscosity and Solvation (United States)

    Robertson, C. T.


    Discusses theories underlying the phenomena of solution viscosities, involving the Jones and Dole equation, B-coefficient determination, and flickering cluster model. Indicates that viscosity measurements provide a basis for the study of the structural effects of ions in aqueous solutions and are applicable in teaching high school chemistry. (CC)

  11. Viscosity measuring using microcantilevers (United States)

    Oden, Patrick Ian


    A method for the measurement of the viscosity of a fluid uses a micromachined cantilever mounted on a moveable base. As the base is rastered while in contact with the fluid, the deflection of the cantilever is measured and the viscosity determined by comparison with standards.

  12. Entropy viscosity method for nonlinear conservation laws

    KAUST Repository

    Guermond, Jean-Luc


    A new class of high-order numerical methods for approximating nonlinear conservation laws is described (entropy viscosity method). The novelty is that a nonlinear viscosity based on the local size of an entropy production is added to the numerical discretization at hand. This new approach does not use any flux or slope limiters, applies to equations or systems supplemented with one or more entropy inequalities and does not depend on the mesh type and polynomial approximation. Various benchmark problems are solved with finite elements, spectral elements and Fourier series to illustrate the capability of the proposed method. © 2010 Elsevier Inc.

  13. Tidal viscosity of Enceladus (United States)

    Efroimsky, Michael


    In the preceding paper (Efroimsky, 2017), we derived an expression for the tidal dissipation rate in a homogeneous near-spherical Maxwell body librating in longitude. Now, by equating this expression to the outgoing energy flux due to the vapour plumes, we estimate the mean tidal viscosity of Enceladus, under the assumption that the Enceladean mantle behaviour is Maxwell. This method yields a value of 0.24 × 1014 Pa s for the mean tidal viscosity, which is very close to the viscosity of ice near the melting point.

  14. Shear Viscosity from Lattice QCD

    CERN Document Server

    Mages, Simon W; Fodor, Zoltán; Schäfer, Andreas; Szabó, Kálmán


    Understanding of the transport properties of the the quark-gluon plasma is becoming increasingly important to describe current measurements at heavy ion collisions. This work reports on recent efforts to determine the shear viscosity h in the deconfined phase from lattice QCD. The main focus is on the integration of the Wilson flow in the analysis to get a better handle on the infrared behaviour of the spectral function which is relevant for transport. It is carried out at finite Wilson flow time, which eliminates the dependence on the lattice spacing. Eventually, a new continuum limit has to be carried out which sends the new regulator introduced by finite flow time to zero. Also the non-perturbative renormalization strategy applied for the energy momentum tensor is discussed. At the end some quenched results for temperatures up to 4 : 5 T c are presented

  15. Imaging aerosol viscosity (United States)

    Pope, Francis; Athanasiadis, Thanos; Botchway, Stan; Davdison, Nicholas; Fitzgerald, Clare; Gallimore, Peter; Hosny, Neveen; Kalberer, Markus; Kuimova, Marina; Vysniauskas, Aurimas; Ward, Andy


    Organic aerosol particles play major roles in atmospheric chemistry, climate, and public health. Aerosol particle viscosity is important since it can determine the ability of chemical species such as oxidants, organics or water to diffuse into the particle bulk. Recent measurements indicate that OA may be present in highly viscous states; however, diffusion rates of small molecules such as water appear not to be limited by these high viscosities. We have developed a technique for measuring viscosity that allows for the imaging of aerosol viscosity in micron sized aerosols through use of fluorescence lifetime imaging of viscosity sensitive dyes which are also known as 'molecular rotors'. These rotors can be introduced into laboratory generated aerosol by adding minute quantities of the rotor to aerosol precursor prior to aerosolization. Real world aerosols can also be studied by doping them in situ with the rotors. The doping is achieved through generation of ultrafine aerosol particles that contain the rotors; the ultrafine aerosol particles deliver the rotors to the aerosol of interest via impaction and coagulation. This work has been conducted both on aerosols deposited on microscope coverslips and on particles that are levitated in their true aerosol phase through the use of a bespoke optical trap developed at the Central Laser Facility. The technique allows for the direct observation of kinetic barriers caused by high viscosity and low diffusivity in aerosol particles. The technique is non-destructive thereby allowing for multiple experiments to be carried out on the same sample. It can dynamically quantify and track viscosity changes during atmospherically relevant processes such oxidation and hygroscopic growth (1). This presentation will focus on the oxidation of aerosol particles composed of unsaturated and saturated organic species. It will discuss how the type of oxidant, oxidation rate and the composition of the oxidized products affect the time

  16. Super-Hamiltonian Structures and Conservation Laws of a New Six-Component Super-Ablowitz-Kaup-Newell-Segur Hierarchy

    Directory of Open Access Journals (Sweden)

    Fucai You


    Full Text Available A six-component super-Ablowitz-Kaup-Newell-Segur (-AKNS hierarchy is proposed by the zero curvature equation associated with Lie superalgebras. Supertrace identity is used to furnish the super-Hamiltonian structures for the resulting nonlinear superintegrable hierarchy. Furthermore, we derive the infinite conservation laws of the first two nonlinear super-AKNS equations in the hierarchy by utilizing spectral parameter expansions. PACS: 02.30.Ik; 02.30.Jr; 02.20.Sv.

  17. "Understanding" cosmological bulk viscosity


    Zimdahl, Winfried


    A universe consisting of two interacting perfect fluids with the same 4-velocity is considered. A heuristic mean free time argument is used to show that the system as a whole cannot be perfect as well but neccessarily implies a nonvanishing bulk viscosity. A new formula for the latter is derived and compared with corresponding results of radiative hydrodynamics.

  18. Viscosity of colloidal suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, E.G.D. [Rockefeller Univ., New York, NY (United States); Schepper, I.M. de [Delft Univ. of Technology (Netherlands)


    Simple expressions are given for the effective Newtonian viscosity as a function of concentration as well as for the effective visco-elastic response as a function of concentration and imposed frequency, of monodisperse neutral colloidal suspensions over the entire fluid range. The basic physical mechanisms underlying these formulae are discussed. The agreement with existing experiments is very good.

  19. Skyrmions and Hall viscosity


    Kim, Bom Soo


    We discuss the contribution of magnetic Skyrmions to the Hall viscosity and propose a simple way to identify it in experiments. The topological Skyrmion charge density has a distinct signature in the electric Hall conductivity that is identified in existing experimental data. In an electrically neutral system, the Skyrmion charge density is directly related to the thermal Hall conductivity. These results are direct consequences of the field theory Ward identities, which relate various physica...

  20. Early dissipation and viscosity


    Bozek, Piotr


    We consider dissipative phenomena due to the relaxation of an initial anisotropic local pressure in the fireball created in relativistic heavy-ion collisions, both for the Bjorken boost-invariant case and for the azimuthally symmetric radial expansion with boost-invariance. The resulting increase of the entropy can be counterbalanced by a suitable retuning of the initial temperature. An increase of the transverse collective flow is observed. The influence of the shear viscosity on the longitu...

  1. Critical Viscosity of Xenon (United States)


    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2001 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure that is placed inside a pressure canister. A similar canister holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (not shown) of the National Institutes of Standards and Technology, Gaithersburg, MD. This is a detail view of MSFC 0100143.

  2. Super-Eddington Accreting Tidal Disruption Events (United States)

    Lin, Dacheng; Guillochon, James; Komossa, St.; Ramirez-Ruiz, Enrico; Irwin, Jimmy; Maksym, W. Peter; Grupe, Dirk; Godet, Olivier; Webb, Natalie; Barret, Didier; Zauderer, Bevin; Duc, Pierre-Alain; Carrasco, Eleazar R.; Gwyn, Stephen


    Multiwavelength flares from tidal disruption and subsequent accretion of stars are important for study of otherwise dormant massive black holes in galactic nuclei. Previous well-monitored candidate flares were short-lived, with most emission confined to within ~1 year. Here, we report our discovery of a well observed super-long (>11 years) luminous X-ray flare from the nuclear region of a dwarf starburst galaxy. After an apparently fast rise within ~4 months a decade ago, the X-ray luminosity, though showing a weak trend of decay, has been persistently high at around the Eddington limit. The X-ray spectra are soft and can be described with Comptonized emission from an optically thick low-temperature corona, a super-Eddington accretion signature often observed in accreting stellar-mass black holes. Dramatic spectral softening was also caught in one recent observation, implying either a temporary transition from the super-Eddington accretion state to the standard thermal state, or the presence of a transient highly blueshifted (~0.36c) warm absorber. All these properties in concert suggest a tidal disruption event with an unusually long super-Eddington accretion phase that has never before been observed. We also found two additional events showing similar X-ray spectra characteristic of super-Eddington accretion from two otherwise quiescent galaxies. Therefore these events seem to form a new, super-Eddington accreting class of tidal disruption events.

  3. Hydrodynamic simulations of accretion flows with time-varying viscosity (United States)

    Roy, Abhishek; Chakrabarti, Sandip K.


    X-ray outbursts of stellar-mass black hole candidates are believed to be due to a sudden rise in viscosity, which transports angular momentum efficiently and increases the accretion rates, causing higher X-ray flux. After the viscosity is reduced, the outburst subsides and the object returns back to the pre-outburst quiescence stage. In the absence of a satisfactory understanding of the physical mechanism leading to such a sharp time dependence of viscous processes, we perform numerical simulations where we include the rise and fall of a viscosity parameter at an outer injection grid, assumed to be located at the accumulation radius where matter from the companion is piled up before being released by enhanced viscosity. We use a power-law radial dependence of the viscosity parameter (α ˜ rɛ), but the exponent (ɛ) is allowed to vary with time to mimic a fast rise and decay of the viscosity parameter. Since X-ray spectra of a black hole candidate can be explained by a Keplerian disc component in the presence of a post-shock region of an advective flow, our goal here is also to understand whether the flow configurations required to explain the spectral states of an outbursting source could be obtained by a time-varying viscosity. We present the results of our simulations to prove that low-angular-momentum (sub-Keplerian) advective flows do form a Keplerian disc in the pre-shock region when the viscosity is enhanced, which disappears on a much longer time-scale after the viscosity is withdrawn. From the variation of the Keplerian disc inside an advective halo, we believe that our result, for the first time, is able to simulate the two-component advective flow dynamics during an entire X-ray outburst and explain the observed hysteresis effects in the hardness-intensity diagram.

  4. Calculus super review

    CERN Document Server


    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Calculus I Super Review includes a review of functions, limits, basic derivatives, the definite integral, combinations, and permutations. Take the Super Review quizzes to see how much you've learned - and where you need more study. Makes an excellent study aid and textbook companion. Great for self-study!DETAILS- From cover to cover, each in-depth topic review is easy-to-follow and easy-to-grasp - Perfect when preparing for

  5. Algebra & trigonometry super review

    CERN Document Server


    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Algebra and Trigonometry Super Review includes sets and set operations, number systems and fundamental algebraic laws and operations, exponents and radicals, polynomials and rational expressions, equations, linear equations and systems of linear equations, inequalities, relations and functions, quadratic equations, equations of higher order, ratios, proportions, and variations. Take the Super Review quizzes to see how much y

  6. Pressure Effect on Extensional Viscosity

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Kjær, Erik Michael


    The primary object of these experiments was to investigate the influence of hydrostatic pressure on entrance flow. The effect of pressure on shear and extensional viscosity was evaluated using an axis symmetric capillary and a slit die where the hydrostatic pressure was raised with valves....... The experiments show a significant increase in extensional viscosity with increasing pressure....

  7. Volatiles Which Increase Magma Viscosity (United States)

    Webb, S.


    The standard model of an erupting volcano is one in which the viscosity of a decompressing magma increases as the volatiles leave the melt structure to form bubbles. It has now been observed that the addition of the "volatiles" P, Cl and F result in an increase in silicate melt viscosity. This observation would mean that the viscosity of selected degassing magmas would decrease rather than increase. Here we look at P, Cl and F as three volatiles which increase viscosity through different structural mechanisms. In all three cases the volatiles increase the viscosity of peralkaline composition melts, but appear to always decrease the viscosity of peraluminous melts. Phosphorus causes the melt to unmix into a Na-P rich phase and a Na-poor silicate phase. Thus as the network modifying Na (or Ca) are removed to the phosphorus-rich melt, the matrix melt viscosity increases. With increasing amounts of added phosphorus (at network modifying Na ~ P) the addition of further phosphorus causes a decrease in viscosity. The addition of chlorine to Fe-free aluminosilicate melts results in an increase in viscosity. NMR data on these glass indicates that the chlorine sits in salt-like structures surrounded by Na and/or Ca. Such structures would remove network-modifying atoms from the melt structure and thus result in an increase in viscosity. The NMR spectra of fluorine-bearing glasses shows that F takes up at least 5 different structural positions in peralkaline composition melts. Three of these positions should result in a decrease in viscosity due to the removal of bridging oxygens. Two of the structural positons of F, however, should result in an increase in viscosity as they require the removal of network-modifying atoms from the melt structure (with one of the structures being that observed for Cl). This would imply that increasing amounts of F might result in an increase in viscosity. This proposed increase in viscosity with increasing F has now been experimentally confirmed.

  8. The viscosity of dimethyl ether

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, Jørgen


    and NOx traps are installed. The most significant problem encountered when engines are fuelled with DME is that the injection equipment breaks down prematurely due to extensive wear. This tribology issue can be explained by the very low lubricity and viscosity of DME. Recently, laboratory methods have...... appeared capable of measuring these properties of DME. The development of this is rendered difficult because DME has to be pressurised to remain in the liquid state and it dissolves most of the commercially available elastomers. This paper deals fundamentally with the measurement of the viscosity of DME...... and extends the discussion to the difficulty of viscosity establishing of very thin fluids. The main issue here is that it is not easy to calibrate the viscometers in the very low viscosity range corresponding to about one-fifth of that of water. The result is that the low viscosity is measured at high...

  9. Capillary waves with surface viscosity (United States)

    Shen, Li; Denner, Fabian; Morgan, Neal; van Wachem, Berend; Dini, Daniele


    Experiments over the last 50 years have suggested a correlation between the surface (shear) viscosity and the stability of a foam or emulsion. With recent techniques allowing more accurate measurements of the elusive surface viscosity, we examine this link theoretically using small-amplitude capillary waves in the presence of the Marangoni effect and surface viscosity modelled via the Boussinesq-Scriven model. The surface viscosity effect is found to contribute a damping effect on the amplitude of the capillary wave with subtle differences to the effect of the convective-diffusive Marangoni transport. The general wave dispersion is augmented to take into account the Marangoni and surface viscosity effects, and a first-order correction to the critical damping wavelength is derived. The authors acknowledge the financial support of the Shell University Technology Centre for fuels and lubricants.

  10. Achromatic and super-achromatic zero-order waveplates (United States)

    Samoylov, A. V.; Samoylov, V. S.; Vidmachenko, A. P.; Perekhod, A. V.


    We discuss a brief classification of waveplates including achromatic and super-achromatic ones. Anizotropic properties of polymethylmethacrylat (PMMA) subjected to one-axis stretching are analyzed. The parameters controlling the value of the PMMA birefringence are identified and their typical spectral dependence is discussed. The technology for manufacturing achromatic and super-achromatic, one-axis-stretched PMMA wavelpates is described, which excludes any mechanical processing of waveplate component surfaces. Technical characteristics of achromatic and super-achromatic waveplates manufactured of the same material (anisotropic PMMA) are discussed. It is shown that the use of the same material eliminates the appearance of interference ripple in transmission, which is a typical characteristic of quarts-MgF2 super-achromatic waveplates. Examples of using super-achromatic waveplates in astronomical observations are described.

  11. Viscosity Measurement for Tellurium Melt (United States)

    Lin, Bochuan; Li, Chao; Ban, Heng; Scripa, Rosalia N.; Su, Ching-Hua; Lehoczky, Sandor L.


    The viscosity of high temperature Te melt was measured using a new technique in which a rotating magnetic field was applied to the melt sealed in a suspended ampoule, and the torque exerted by rotating melt flow on the ampoule wall was measured. Governing equations for the coupled melt flow and ampoule torsional oscillation were solved, and the viscosity was extracted from the experimental data by numerical fitting. The computational result showed good agreement with experimental data. The melt velocity transient initiated by the rotating magnetic field reached a stable condition quickly, allowing the viscosity and electrical conductivity of the melt to be determined in a short period.

  12. SuperB, the super flavor factory


    Hitlin, D.G.


    Heavy flavor physics measurements, in particular B and τ physics results from the B Factories, currently provide strong constraints on models of physics beyond the Standard Model. SuperB, a next generation asymmetric collider with 50 to 100 times the luminosity of existing colliders, can, in a dialog with LHC and ILC, provide unique insights into New Physics phenomena seen at those machines.

  13. SuperB, the super flavor factory (United States)

    Hitlin, D. G.


    Heavy flavor physics measurements, in particular B and τ physics results from the B Factories, currently provide strong constraints on models of physics beyond the Standard Model. SuperB, a next generation asymmetric collider with 50 to 100 times the luminosity of existing colliders, can, in a dialog with LHC and ILC, provide unique insights into New Physics phenomena seen at those machines.

  14. Nonlinear Super Integrable Couplings of Super Classical-Boussinesq Hierarchy

    Directory of Open Access Journals (Sweden)

    Xiuzhi Xing


    Full Text Available Nonlinear integrable couplings of super classical-Boussinesq hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then, its super Hamiltonian structures were established by using super trace identity. As its reduction, nonlinear integrable couplings of the classical integrable hierarchy were obtained.

  15. Viscosity of particle laden films (United States)

    Timounay, Yousra; Rouyer, Florence


    We perform retraction experiments on soap films where large particles bridge the two interfaces. Local velocities are measured by PIV during the unstationnary regime. The velocity variation in time and space can be described by a continuous fluid model from which effective viscosity (shear and dilatational) of particulate films is measured. The 2D effective viscosity of particulate films η2D increases with particle surface fraction ϕ: at low ϕ, it tends to the interfacial dilatational viscosity of the liquid/air interfaces and it diverges at the critical particle surface fraction ϕc ≃ 0.84. Experimental data agree with classical viscosity laws of hard spheres suspensions adapted to the 2D geometry, assuming viscous dissipation resulting from the squeeze of the liquid/air interfaces between the particles. Finally, we show that the observed viscous dissipation in particulate films has to be considered to describe the edge velocity during a retraction experiment at large particle coverage.

  16. Comparison of Parallel Viscosity with Neoclassical Theory


    K., Ida; N., Nakajima


    Toroidal rotation profiles are measured with charge exchange spectroscopy for the plasma heated with tangential NBI in CHS heliotron/torsatron device to estimate parallel viscosity. The parallel viscosity derived from the toroidal rotation velocity shows good agreement with the neoclassical parallel viscosity plus the perpendicular viscosity. (mu_perp =2m^2 /s).

  17. Computing the viscosity of supercooled liquids: Markov Network model.

    Directory of Open Access Journals (Sweden)

    Ju Li

    Full Text Available The microscopic origin of glass transition, when liquid viscosity changes continuously by more than ten orders of magnitude, is challenging to explain from first principles. Here we describe the detailed derivation and implementation of a Markovian Network model to calculate the shear viscosity of deeply supercooled liquids based on numerical sampling of an atomistic energy landscape, which sheds some light on this transition. Shear stress relaxation is calculated from a master-equation description in which the system follows a transition-state pathway trajectory of hopping among local energy minima separated by activation barriers, which is in turn sampled by a metadynamics-based algorithm. Quantitative connection is established between the temperature variation of the calculated viscosity and the underlying potential energy and inherent stress landscape, showing a different landscape topography or "terrain" is needed for low-temperature viscosity (of order 10(7 Pa·s from that associated with high-temperature viscosity (10(-5 Pa·s. Within this range our results clearly indicate the crossover from an essentially Arrhenius scaling behavior at high temperatures to a low-temperature behavior that is clearly super-Arrhenius (fragile for a Kob-Andersen model of binary liquid. Experimentally the manifestation of this crossover in atomic dynamics continues to raise questions concerning its fundamental origin. In this context this work explicitly demonstrates that a temperature-dependent "terrain" characterizing different parts of the same potential energy surface is sufficient to explain the signature behavior of vitrification, at the same time the notion of a temperature-dependent effective activation barrier is quantified.

  18. Fast Super-Resolution Imaging with Ultra-High Labeling Density Achieved by Joint Tagging Super-Resolution Optical Fluctuation Imaging (JT-SOFI)

    CERN Document Server

    Zeng, Zhiping; Wang, Hening; Huang, Ning; Shan, Chunyan; Zhang, Hao; Teng, Junlin; Xi, Peng


    Previous stochastic localization-based super-resolution techniques are largely limited by the labeling density and the fidelity to the morphology of specimen. We report on an optical super-resolution imaging scheme implementing joint tagging using multiple fluorescent blinking dyes associated with super-resolution optical fluctuation imaging (JT-SOFI), achieving ultra-high labeling density super-resolution imaging. To demonstrate the feasibility of JT-SOFI, quantum dots with different emission spectra were jointly labeled to the tubulin in COS7 cells, creating ultra-high density labeling. After analyzing and combining the fluorescence intermittency images emanating from spectrally resolved quantum dots, the microtubule networks are capable of being investigated with high fidelity and remarkably enhanced contrast at sub-diffraction resolution. The spectral separation also significantly decreased the frame number required for SOFI, enabling fast super-resolution microscopy through simultaneous data acquisition....

  19. Deforming super Riemann surfaces with gravitinos and super Schottky groups

    Energy Technology Data Exchange (ETDEWEB)

    Playle, Sam [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino,Via P. Giuria 1, I-10125 Torino (Italy)


    The (super) Schottky uniformization of compact (super) Riemann surfaces is briefly reviewed. Deformations of super Riemann surface by gravitinos and Beltrami parameters are recast in terms of super Schottky group cohomology. It is checked that the super Schottky group formula for the period matrix of a non-split surface matches its expression in terms of a gravitino and Beltrami parameter on a split surface. The relationship between (super) Schottky groups and the construction of surfaces by gluing pairs of punctures is discussed in an appendix.

  20. Viscosity kernel of molecular fluids

    DEFF Research Database (Denmark)

    Puscasu, Ruslan; Todd, Billy; Daivis, Peter


    The wave-vector dependent shear viscosities for butane and freely jointed chains have been determined. The transverse momentum density and stress autocorrelation functions have been determined by equilibrium molecular dynamics in both atomic and molecular hydrodynamic formalisms. The density......, temperature, and chain length dependencies of the reciprocal and real-space viscosity kernels are presented. We find that the density has a major effect on the shape of the kernel. The temperature range and chain lengths considered here have by contrast less impact on the overall normalized shape. Functional...... forms that fit the wave-vector-dependent kernel data over a large density and wave-vector range have also been tested. Finally, a structural normalization of the kernels in physical space is considered. Overall, the real-space viscosity kernel has a width of roughly 3–6 atomic diameters, which means...

  1. Viscosity Control Experiment Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Heidi E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bradley, Paul Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Turbulent mix has been invoked to explain many results in Inertial Confinement Fusion (ICF) and High Energy Density (HED) physics, such as reduced yield in capsule implosions. Many ICF capsule implosions exhibit interfacial instabilities seeded by the drive shock, but it is not clear that fully developed turbulence results from this. Many simulations use turbulent mix models to help match simulation results to data, but this is not appropriate if turbulence is not present. It would be useful to have an experiment where turbulent mixing could be turned on or off by design. The use of high-Z dopants to modify viscosity and the resulting influence on turbulence is considered here. A complicating factor is that the plasma in some implosions can become strongly coupled, which makes the Spitzer expression for viscosity invalid. We first consider equations that cover a broad parameter space in temperature and density to address regimes for various experimental applications. Next, a previous shock-tube and other ICF experiments that investigate viscosity or use doping to examine the effects on yield are reviewed. How viscosity and dopants play a role in capsule yield depends on the region and process under consideration. Experiments and simulations have been performed to study the effects of viscosity on both the hot spot and the fuel/ablator mix. Increases in yield have been seen for some designs, but not all. We then discuss the effect of adding krypton dopant to the gas region of a typical OMEGA and a 2-shock NIF implosion to determine approximately the effect of adding dopant on the computed Reynolds number. Recommendations for a path forward for possible experiments using high-Z dopants to affect viscosity and turbulence are made.

  2. Super earth explorer: a coronagraphic off-axis space telescope

    NARCIS (Netherlands)

    Stam, D.; Keller, C.U.|info:eu-repo/dai/nl/304824550


    The Super-Earth Explorer is an Off-Axis Space Telescope (SEE-COAST) designed for high contrast imaging. Its scientific objective is to make the physico-chemical characterization of exoplanets possibly down to 2 Earth radii. For that purpose it will analyze the spectral and polarimetric properties of

  3. SuperQuant

    DEFF Research Database (Denmark)

    Gorshkov, Vladimir; Verano-Braga, Thiago; Kjeldsen, Frank


    ). Peptides were fragmented with collision-induced dissociation using isolation windows of 1, 2, and 4 Th while recording data both with high-resolution and low-resolution. The results obtained using SuperQuant were compared to those using the conventional ion trap-based approach (low mass accuracy MS2...... spectra), which is known to achieve high identification performance. Compared to the common high-resolution approach, the SuperQuant approach identifies up to 70% more peptide-spectrum matches (PSMs), 40% more peptides, and 20% more proteins at the 0.01 FDR level. It identifies more PSMs and peptides than......SuperQuant is a quantitative proteomics data processing approach that uses complementary fragment ions to identify multiple co-isolated peptides in tandem mass spectra allowing for their quantification. This approach can be applied to any shotgun proteomics data set acquired with high mass accuracy...

  4. Super-resolution

    DEFF Research Database (Denmark)

    Nasrollahi, Kamal; Moeslund, Thomas B.


    and aerial imaging to medical image processing, to facial image analysis, text image analysis, sign and number plates reading, and biometrics recognition, to name a few. This has resulted in many research papers, each developing a new super-resolution algorithm for a specific purpose. The current...... comprehensive survey provides an overview of most of these published works by grouping them in a broad taxonomy. For each of the groups in the taxonomy, the basic concepts of the algorithms are first explained and then the paths through which each of these groups have evolved are given in detail, by mentioning...... the contributions of different authors to the basic concepts of each group. Furthermore, common issues in super-resolution algorithms, such as imaging models and registration algorithms, optimization of the cost functions employed, dealing with color information, improvement factors, assessment of super...

  5. SuperSegger

    DEFF Research Database (Denmark)

    Stylianidou, Stella; Brennan, Connor; Nissen, Silas B


    Many quantitative cell biology questions require fast yet reliable automated image segmentation to identify and link cells from frame-to-frame, and characterize the cell morphology and fluorescence. We present SuperSegger, an automated MATLAB-based image processing package well......-suited to quantitative analysis of high-throughput live-cell fluorescence microscopy of bacterial cells. SuperSegger incorporates machine-learning algorithms to optimize cellular boundaries and automated error resolution to reliably link cells from frame-to-frame. Unlike existing packages, it can reliably segment micro......, and computing statistics on cellular fluorescence, the location and intensity of fluorescent foci. SuperSegger provides a variety of post-processing data visualization tools for single cell and population level analysis, such as histograms, kymographs, frame mosaics, movies, and consensus images. Finally, we...

  6. Super Star Clusters (United States)

    O'Connell, R. W.


    Super star clusters represent an extreme in the star formation process. They are very luminous, compact objects with L_V > 10(6) L_{V,sun} and diameters = 100 times higher than normal OB associations and clusters in ``giant H II regions''. Prior to HST about a dozen such objects had been identified in nearby galaxies, but at ground-based resolution they are nearly point sources. We review recent HST observations of individual super star clusters in NGC 1140, 1569, and 1705. They have half-light radii of only 2--3.5 pc, and some show evidence of substructure which should be resolvable with the repaired HST. After allowing for age differences, the surface brightness of NGC 1569-A is over 65 times higher than the core of 30 Doradus in the LMC and 1200 times higher than the mean rich LMC star cluster. In some cases, the energy released by the clusters into their surroundings is sufficient to drive galaxy-wide winds. Their properties make super star clusters good analogues of young globular clusters. In some, though not all, cases super star clusters appear to form in the aftermath of a merger or accretion event. The most impressive examples are the clusters detected by HST in NGC 1275 and 7252, one of which has the extraordinary luminosity ~ 6 times 10(8) L_{V,sun}. M82 affords a nearby view of a post-interaction system. HST imaging has identified over 80 super star clusters in its central regions with mean luminosities of ~ 3 times 10(6) L_{V,sun}. Their close packing and signs of interaction with the well-known supernova-driven wind suggest that they do not evolve independently. Super cluster evolution in starbursts is probably a collective phenomenon.

  7. Raspberry Pi super cluster

    CERN Document Server

    Dennis, Andrew K


    This book follows a step-by-step, tutorial-based approach which will teach you how to develop your own super cluster using Raspberry Pi computers quickly and efficiently.Raspberry Pi Super Cluster is an introductory guide for those interested in experimenting with parallel computing at home. Aimed at Raspberry Pi enthusiasts, this book is a primer for getting your first cluster up and running.Basic knowledge of C or Java would be helpful but no prior knowledge of parallel computing is necessary.

  8. Viscosity in hot mix construction. (United States)


    Viscosity, one of the oldest known and tested properties of Asphalt, yet one of the least studied is recently being given the attention it so rightfully deserves. Numerous engineers did recognize the importance of this property to the extent that sev...

  9. Effective viscosity of confined hydrocarbons

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V.N.; Persson, B.N.J.


    We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity ηeff for nanometer-thin films depends linearly on the logarithm of the shear rate: log ηeff=C-nlog γ̇, where...

  10. Fission hindrance and nuclear viscosity

    Indian Academy of Sciences (India)


    Jul 29, 2015 ... We discuss the role of nuclear viscosity in hindering the fission of heavy nuclei as observed in the experimental measurements of GDR -ray spectra from the fissioning nuclei. We review a set of experiments carried out and reported by us previously [see Dioszegi et al, Phys. Rev. C 61, 024613 (2000); ...

  11. Fission hindrance and nuclear viscosity

    Indian Academy of Sciences (India)

    is in exact conformity with all the previous measurements [7,10–13]. The CASCADE calculations (solid lines in figure 1) used in this first level of analysis do not include any viscosity or temperature-dependent nuclear level density parameter a. The γ and particle decay are calculated using the standard prescriptions as ...

  12. Handbook of Super 8 Production. (United States)

    Telzer, Ronnie, Ed.

    This handbook is designed for anyone interested in producing super 8 films at any level of complexity and cost. Separate chapters present detailed discussions of the following topics: super 8 production systems and super 8 shooting and editing systems; budgeting; cinematography and sound recording; preparing to edit; editing; mixing sound tracks;…

  13. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken


    This paper describes the application results of a previous and current EU-project on super insulating glazing based on monolithic silica aerogel. Prototypes measuring approx. 55´55 cm2 have been made with 15 mm evacuated aerogel between two layers of low-iron glass. Anti-reflective treatment...

  14. Optimal Super Dielectric Material (United States)


    that must be overcome to provide soldiers and sailors full electronic capability without hindrance due to size, weight or operating costs [6]. The...Publishers, 2004. [26] H. Lee, N. Byamba-Ochir, W. Shim, M. Balathanigaimani, and H. Moon , “High- performance super capacitors based on activated

  15. 'SuperMac' Apple

    NARCIS (Netherlands)

    Khanizadeh, S.; Groleau, Y.; Levasseur, A.; Carisse, O.; Rekika, D.; DeEll, J.; Prive, J.P.; Alli, I.; Kemp, H.


    `SuperMac' (Malus xdomestica Borkh) is being released as a replacement for `Spartan', which is presently being grown in Eastern Canada for its excellent shelf life. However, it is susceptibility to scab [Venturia inaequalis (Cke) Wint.], the most common apple disease. This new cultivar produces

  16. Super B Factories

    Indian Academy of Sciences (India)

    the magnet power supplies, the RF system, the digital feedback system, and many vacuum components. This should reduce the cost and engineering effort needed to bring the project to fruition [13]. This Super B Factory concept is generating substantial interest in the physics community. It may, in fact, be the most promising ...

  17. Creating a Super Instrument

    DEFF Research Database (Denmark)

    Kallionpää, Maria; Gasselseder, Hans-Peter


    traditionally been dependent on their existing instrumental skills, various technological solutions can be used to reach beyond them. This paper focuses on the possibilities of enhancing composers' and performing pianists' technical and expressive vocabulary in the context of electroacoustic super instrument...

  18. Nonlinear Super Integrable Couplings of Super Broer-Kaup-Kupershmidt Hierarchy and Its Super Hamiltonian Structures

    Directory of Open Access Journals (Sweden)

    Sixing Tao


    Full Text Available Nonlinear integrable couplings of super Broer-Kaup-Kupershmidt hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then its super Hamiltonian structures were established by using super trace identity, and the conserved functionals were proved to be in involution in pairs under the defined Poisson bracket. As its reduction, nonlinear integrable couplings of the classical integrable hierarchy were obtained.

  19. Density and viscosity of lipids under pressure (United States)

    There is a lack of data for the viscosity of lipids under pressure. The current report is a part of the effort to fill this gap. The viscosity, density, and elastohydrodynamic film thicknesses of vegetable oil (HOSuO) were investigated. Pressure–viscosity coefficients (PVC) of HOSuO at different tem...

  20. Effect of viscosity on learned satiation

    NARCIS (Netherlands)

    Mars, M.; Hogenkamp, P.S.; Gosses, A.M.; Stafleu, A.; Graaf,


    A higher viscosity of a food leads to a longer orosensory stimulation. This may facilitate the learned association between sensory signals and metabolic consequences. In the current study we investigated the effect of viscosity on learned satiation. In two intervention groups a low viscosity (LV)

  1. Mechanism of viscosity modification in multigrade oils

    Energy Technology Data Exchange (ETDEWEB)

    Song, W.R.


    Multigrade motor oil viscosity modifiers such as acrylates, polyisobutylene, and olefin copolymers were examined to compare the basic physical properties of these polymers. Results of viscosity measurements and hydrodynamic volume changes are tabulated and discussed. Discussions are also included on temporary viscosity losses in polymer solutions. (JRD)

  2. Shear viscosity of nuclear matter (United States)

    Magner, A. G.; Gorenstein, M. I.; Grygoriev, U. V.; Plujko, V. A.


    Shear viscosity η is calculated for the nuclear matter described as a system of interacting nucleons with the van der Waals (VDW) equation of state. The Boltzmann-Vlasov kinetic equation is solved in terms of the plane waves of the collective overdamped motion. In the frequent-collision regime, the shear viscosity depends on the particle-number density n through the mean-field parameter a , which describes attractive forces in the VDW equation. In the temperature region T =15 -40 MeV, a ratio of the shear viscosity to the entropy density s is smaller than 1 at the nucleon number density n =(0.5 -1.5 ) n0 , where n0=0.16 fm-3 is the particle density of equilibrium nuclear matter at zero temperature. A minimum of the η /s ratio takes place somewhere in a vicinity of the critical point of the VDW system. Large values of η /s ≫1 are, however, found in both the low-density, n ≪n0 , and high-density, n >2 n0 , regions. This makes the ideal hydrodynamic approach inapplicable for these densities.

  3. Nonlocal viscosity kernel of mixtures (United States)

    Smith, Ben; Hansen, J. S.; Todd, B. D.


    In this Brief Report we investigate the multiscale hydrodynamical response of a liquid as a function of mixture composition. This is done via a series of molecular dynamics simulations in which the wave-vector-dependent viscosity kernel is computed for three mixtures, each with 7-15 different compositions. We observe that the viscosity kernel is dependent on composition for simple atomic mixtures for all the wave vectors studied here; however, for a molecular mixture the kernel is independent of composition for large wave vectors. The deviation from ideal mixing is also studied. Here it is shown that the Lorentz-Berthelot interaction rule follows ideal mixing surprisingly well for a large range of wave vectors, whereas for both the Kob-Andersen and molecular mixtures large deviations are found. Furthermore, for the molecular system the deviation is wave-vector dependent such that there exists a characteristic correlation length scale at which the ideal mixing goes from underestimating to overestimating the viscosity.

  4. Viscosity of Earth's Outer Core

    CERN Document Server

    Smylie, D E


    A viscosity profile across the entire fluid outer core is found by interpolating between measured boundary values, using a differential form of the Arrhenius law governing pressure and temperature dependence. The discovery that both the retrograde and prograde free core nutations are in free decay (Palmer and Smylie, 2005) allows direct measures of viscosity at the top of the outer core, while the reduction in the rotational splitting of the two equatorial translational modes of the inner core allows it to be measured at the bottom. We find 2,371 plus/minus 1,530 Pa.s at the top and 1.247 plus/minus 0.035 x 10^11 Pa.s at the bottom. Following Brazhkin (1998) and Brazhkin and Lyapin (2000) who get 10^2 Pa.s at the top, 10^11 Pa.s at the bottom, by an Arrhenius extrapolation of laboratory experiments, we use a differential form of the Arrhenius law to interpolate along the melting temperature curve to find a viscosity profile across the outer core. We find the variation to be closely log-linear between the meas...

  5. Performing the Super Instrument

    DEFF Research Database (Denmark)

    Kallionpaa, Maria


    The genre of contemporary classical music has seen significant innovation and research related to new super, hyper, and hybrid instruments, which opens up a vast palette of expressive potential. An increasing number of composers, performers, instrument designers, engineers, and computer programmers...... have become interested in different ways of “supersizing” acoustic instruments in order to open up previously-unheard instrumental sounds. Super instruments vary a great deal but each has a transformative effect on the identity and performance practice of the performing musician. Furthermore, composers...... provides the performer extensive virtuoso capabilities in terms of instrumental range, harmony, timbre, or spatial, textural, acoustic, technical, or technological qualities. The discussion will be illustrated by a composition case study involving augmented musical instrument electromagnetic resonator...

  6. Viscosity bound for anisotropic superfluids in higher derivative gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, Arpan; Roychowdhury, Dibakar [Centre for High Energy Physics, Indian Institute of Science,C.V. Raman Avenue, Bangalore 560012 (India)


    In the present paper, based on the principles of gauge/gravity duality we analytically compute the shear viscosity to entropy (η/s) ratio corresponding to the super fluid phase in Einstein Gauss-Bonnet gravity. From our analysis we note that the ratio indeed receives a finite temperature correction below certain critical temperature (T

  7. Minimal Super Technicolor

    DEFF Research Database (Denmark)

    Antola, M.; Di Chiara, S.; Sannino, F.


    We introduce novel extensions of the Standard Model featuring a supersymmetric technicolor sector (supertechnicolor). As the first minimal conformal supertechnicolor model we consider N=4 Super Yang-Mills which breaks to N=1 via the electroweak interactions. This is a well defined, economical......, between unparticle physics and Minimal Walking Technicolor. We consider also other N =1 extensions of the Minimal Walking Technicolor model. The new models allow all the standard model matter fields to acquire a mass....

  8. Characterising Super-Earths

    Directory of Open Access Journals (Sweden)

    Valencia D.


    Full Text Available The era of Super-Earths has formally begun with the detection of transiting low-mass exoplanets CoRoT-7b and GJ 1214b. In the path of characterising super-Earths, the first step is to infer their composition. While the discovery data for CoRoT-7b, in combination with the high atmospheric mass loss rate inferred from the high insolation, suggested that it was a rocky planet, the new proposed mass values have widened the possibilities. The combined mass range 1−10 M⊕ allows for a volatile-rich (and requires it if the mass is less than 4 M⊕ , an Earth-like or a super-Mercury-like composition. In contrast, the radius of GJ 1214b is too large to admit a solid composition, thus it necessarily to have a substantial gas layer. Some evidence suggests that within this gas layer H/He is a small but non-negligible component. These two planets are the first of many transiting low-mass exoplanets expected to be detected and they exemplify the limitations faced when inferring composition, which come from the degenerate character of the problem and the large error bars in the data.

  9. Effective viscosity of actively swimming algae suspensions (United States)

    Ewoldt, Randy; Caretta, Lucas; Chengala, Anwar; Sheng, Jian


    Suspensions of actively swimming microorganisms exhibit an effective viscosity which may depend on volume fraction, cell shape, and the nature of locomotion (e.g. "pushers" vs. "pullers"). Here we report experimental measurements of shear viscosity for suspensions of unicellular green algae (Dunaliella primolecta, a biflagellated "puller"). We use a cone-and-plate rheometer to measure the dynamic shear viscosity for both motile and non-motile suspensions of D. primolecta. Viscosity increases with concentration for both cases, but the active suspensions of "pullers" have a comparatively lower effective viscosity than passive suspensions. This observation contrasts recently proposed theories which predict that "pullers" should instead have a higher viscosity than non-motile suspensions. Additionally, we observe shear-induced migration of active suspensions and consider its impact on the resulting effective shear viscosity.

  10. Super-quantum curves from super-eigenvalue models

    Energy Technology Data Exchange (ETDEWEB)

    Ciosmak, Paweł [Faculty of Mathematics, Informatics and Mechanics, University of Warsaw,ul. Banacha 2, 02-097 Warsaw (Poland); Hadasz, Leszek [M. Smoluchowski Institute of Physics, Jagiellonian University,ul. Łojasiewicza 11, 30-348 Kraków (Poland); Manabe, Masahide [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Sułkowski, Piotr [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E. California Blvd, Pasadena, CA 91125 (United States)


    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  11. Coumarin-Rhodamine Hybrids-Novel Probes for the Optical Measurement of Viscosity and Polarity. (United States)

    Scholz, Norman; Jadhav, Amol; Shreykar, Milind; Behnke, Thomas; Nirmalananthan, Nithiya; Resch-Genger, Ute; Sekar, Nagaiyan


    A comprehensive systematic study of absorption and fluorescence properties in solvents of varying viscosity and polarity of three novel and red-emitting coumarin-rhodamine hybrid derivatives with differences in the rigidity of their substituents is presented. This includes ethanol-polyethylene glycol, toluene-polyethylene glycol, and toluene-paraffin mixtures. Moreover, protonation-induced effects on the spectroscopic properties are studied. A viscosity-induced emission enhancement was observed for all coumarin-rhodamine hybrid derivatives. MCR2 bearing a julolidine donor showed the expected low sensitivity to viscosity whereas MCR3 with its freely rotatable diphenylamino substituent revealed a particularly pronounced sensitivity to this parameter. Moreover, MCR2 shows an enhancement in emission in the open, i.e., protonated form in conjunction with a largely Stokes shift fluorescence in the deep red spectral region. This enables the application of these dyes as viscosity sensors and as far red emitting pH-sensitive probes.

  12. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana


    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  13. Drop Spreading with Random Viscosity (United States)

    Xu, Feng; Jensen, Oliver


    Airway mucus acts as a barrier to protect the lung. However as a biological material, its physical properties are known imperfectly and can be spatially heterogeneous. In this study we assess the impact of these uncertainties on the rate of spreading of a drop (representing an inhaled aerosol) over a mucus film. We model the film as Newtonian, having a viscosity that depends linearly on the concentration of a passive solute (a crude proxy for mucin proteins). Given an initial random solute (and hence viscosity) distribution, described as a Gaussian random field with a given correlation structure, we seek to quantify the uncertainties in outcomes as the drop spreads. Using lubrication theory, we describe the spreading of the drop in terms of a system of coupled nonlinear PDEs governing the evolution of film height and the vertically-averaged solute concentration. We perform Monte Carlo simulations to predict the variability in the drop centre location and width (1D) or area (2D). We show how simulation results are well described (at much lower computational cost) by a low-order model using a weak disorder expansion. Our results show for example how variability in the drop location is a non-monotonic function of the solute correlation length increases. Engineering and Physical Sciences Research Council.

  14. The spectral shift function and spectral flow


    Azamov, N. A.; Carey, A.L.; Sukochev, F. A.


    This paper extends Krein's spectral shift function theory to the setting of semifinite spectral triples. We define the spectral shift function under these hypotheses via Birman-Solomyak spectral averaging formula and show that it computes spectral flow.

  15. The super-LHC

    CERN Document Server

    Mangano, Michelangelo L


    We review here the prospects of a long-term upgrade programme for the Large Hadron Collider (LHC), CERN laboratory's new proton-proton collider. The super-LHC, which is currently under evaluation and design, is expected to deliver of the order of ten times the statistics of the LHC. In addition to a non-technical summary of the principal physics arguments for the upgrade, I present a pedagogical introduction to the technological challenges on the accelerator and experimental fronts, and a review of the current status of the planning.

  16. Super-heptazethrene

    KAUST Repository

    Zeng, Wangdong


    The challenging synthesis of a laterally extended heptazethrene molecule, the super-heptazethrene derivative SHZ-CF3, is reported. This molecule was prepared using a strategy involving a multiple selective intramolecular Friedel–Crafts alkylation followed by oxidative dehydrogenation. Compound SHZ-CF3 exhibits an open-shell singlet diradical ground state with a much larger diradical character compared with the heptazethrene derivatives. An intermediate dibenzo-terrylene SHZ-2H was also obtained during the synthesis. This study provides a new synthetic method to access large-size quinoidal polycyclic hydrocarbons with unique physical properties.

  17. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken


    Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties...

  18. Modular: The Super Computer


    Malashevich, B.,; Malashevich, D.,


    International audience; This article is deals with the history modular arithmetic, based on the rest classes calculus system «Restklassenarithmetik» (RCCS), or Modular Arithmetic, regarding its creation and development in the USSR. Characteristics of the USSR first modular super-computers: “Т-340А”, “К-340А”, “Diamond (Алмаз)” and “5E53” and their development history are briefly considered. A brief analysis of the weakening of interest in the modular arithmetic in the USSR and its subsequent ...

  19. Transport Signatures of the Hall Viscosity. (United States)

    Delacrétaz, Luca V; Gromov, Andrey


    Hall viscosity is a nondissipative response function describing momentum transport in two-dimensional systems with broken parity. It is quantized in the quantum Hall regime, and contains information about the topological order of the quantum Hall state. Hall viscosity can distinguish different quantum Hall states with identical Hall conductances, but different topological order. To date, an experimentally accessible signature of Hall viscosity is lacking. We exploit the fact that Hall viscosity contributes to charge transport at finite wavelengths, and can therefore be extracted from nonlocal resistance measurements in inhomogeneous charge flows. We explain how to determine the Hall viscosity from such a transport experiment. In particular, we show that the profile of the electrochemical potential close to contacts where current is injected is sensitive to the value of the Hall viscosity.

  20. Viscosity dictates metabolic activity of Vibrio ruber (United States)

    Borić, Maja; Danevčič, Tjaša; Stopar, David


    Little is known about metabolic activity of bacteria, when viscosity of their environment changes. In this work, bacterial metabolic activity in media with viscosity ranging from 0.8 to 29.4 mPas was studied. Viscosities up to 2.4 mPas did not affect metabolic activity of Vibrio ruber. On the other hand, at 29.4 mPas respiration rate and total dehydrogenase activity increased 8 and 4-fold, respectively. The activity of glucose-6-phosphate dehydrogenase (GPD) increased up to 13-fold at higher viscosities. However, intensified metabolic activity did not result in faster growth rate. Increased viscosity delayed the onset as well as the duration of biosynthesis of prodigiosin. As an adaptation to viscous environment V. ruber increased metabolic flux through the pentose phosphate pathway and reduced synthesis of a secondary metabolite. In addition, V. ruber was able to modify the viscosity of its environment. PMID:22826705

  1. Viscosity in Modified Gravity 

    Directory of Open Access Journals (Sweden)

    Iver Brevik


    Full Text Available A bulk viscosity is introduced in the formalism of modified gravity. It is shownthat, based on a natural scaling law for the viscosity, a simple solution can be found forquantities such as the Hubble parameter and the energy density. These solutions mayincorporate a viscosity-induced Big Rip singularity. By introducing a phase transition inthe cosmic fluid, the future singularity can nevertheless in principle be avoided. 

  2. Uniaxial Elongational viscosity of bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole


    The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational...... viscosity, of up to a factor of 7 times the Trouton limit of 3 times the zero-shear viscosity....

  3. Super-multiplex vibrational imaging (United States)

    Wei, Lu; Chen, Zhixing; Shi, Lixue; Long, Rong; Anzalone, Andrew V.; Zhang, Luyuan; Hu, Fanghao; Yuste, Rafael; Cornish, Virginia W.; Min, Wei


    The ability to visualize directly a large number of distinct molecular species inside cells is increasingly essential for understanding complex systems and processes. Even though existing methods have successfully been used to explore structure-function relationships in nervous systems, to profile RNA in situ, to reveal the heterogeneity of tumour microenvironments and to study dynamic macromolecular assembly, it remains challenging to image many species with high selectivity and sensitivity under biological conditions. For instance, fluorescence microscopy faces a ‘colour barrier’, owing to the intrinsically broad (about 1,500 inverse centimetres) and featureless nature of fluorescence spectra that limits the number of resolvable colours to two to five (or seven to nine if using complicated instrumentation and analysis). Spontaneous Raman microscopy probes vibrational transitions with much narrower resonances (peak width of about 10 inverse centimetres) and so does not suffer from this problem, but weak signals make many bio-imaging applications impossible. Although surface-enhanced Raman scattering offers high sensitivity and multiplicity, it cannot be readily used to image specific molecular targets quantitatively inside live cells. Here we use stimulated Raman scattering under electronic pre-resonance conditions to image target molecules inside living cells with very high vibrational selectivity and sensitivity (down to 250 nanomolar with a time constant of 1 millisecond). We create a palette of triple-bond-conjugated near-infrared dyes that each displays a single peak in the cell-silent Raman spectral window; when combined with available fluorescent probes, this palette provides 24 resolvable colours, with the potential for further expansion. Proof-of-principle experiments on neuronal co-cultures and brain tissues reveal cell-type-dependent heterogeneities in DNA and protein metabolism under physiological and pathological conditions, underscoring the

  4. Quantitative super-resolution microscopy

    NARCIS (Netherlands)

    Harkes, Rolf


    Super-Resolution Microscopy is an optical fluorescence technique. In this thesis we focus on single molecule super-resolution, where the position of single molecules is determined. Typically these molecules can be localized with a 10 to 30nm precision. This technique is applied in four different

  5. Super D-branes revisited

    NARCIS (Netherlands)

    Bergshoeff, E.; Townsend, P.K.


    A version of the κ-symmetric super Dp-brane action is presented in which the tension is a dynamical variable, equal to the flux of a p-form world-volume gauge field. The Lagrangian is shown to be invariant under all (super)isometries of the background for appropriate transformations of the

  6. Drop spreading with random viscosity

    CERN Document Server

    Xu, Feng


    We examine theoretically the spreading of a viscous liquid drop over a thin film of uniform thickness, assuming the liquid's viscosity is regulated by the concentration of a solute that is carried passively by the spreading flow. The solute is assumed to be initially heterogeneous, having a spatial distribution with prescribed statistical features. To examine how this variability influences the drop's motion, we investigate spreading in a planar geometry using lubrication theory, combining numerical simulations with asymptotic analysis. We assume diffusion is sufficient to suppress solute concentration gradients across but not along the film. The solute field beneath the bulk of the drop is stretched by the spreading flow, such that the initial solute concentration immediately behind the drop's effective contact lines has a long-lived influence on the spreading rate. Over long periods, solute swept up from the precursor film accumulates in a short region behind the contact line, allowing patches of elevated v...


    Directory of Open Access Journals (Sweden)

    Rita Prasetyowati


    Full Text Available This study aims to determine the value of the kinematic viscosity lubricants motorcycle that has been used at various temperatures and the use of distance. This study also aims to remedy mengtahui how the value of the kinematic viscosity of the lubricant car that has been used in a wide range of temperature variation and distance usage. Viscosity liquid, in this case is the lubricants, can be determined using the Redwood viscometer By using Redwood viscometer, can be measured flow time required by 50 ml of the sample at a constant temperature. Time measurement result is known as the Redwood's sec or conventional viscosity. Conventional viscosity can be determined from the kinematic viscosity values. For motorcycle lubricant viscosity measured at a temperature of 30ͦ C, 50ͦ C, 65ͦ C and 100ͦ C, with the use of distance variation 0 Km, 5 Km, 10 Km, 15 Km and 20 Km. For car lubricant viscosity measured at a temperature of 30ͦ C, 50ͦ C, 65ͦ C and 100ͦ C, with variations in the use of distance 0 km, 1000 km, 5000 km, and 10000 Km. Motorcycle lubricant viscosity values at a temperature of 100ͦ C is 9.54 m2 / s (new lubricant, 1.15 m2 / s (use 5 Km, 5.86 m2 / s (use of 10 Km, 8.02 m2 / s (use of 15 Km, and 9.11 m2 / s (use of 20 Km. Lubricant viscosity values at a temperature of 1000C car is 6.73 m 2 / s (new lubricant, 7.89 m2 / s (use 1,000 km, 6.0 m2 / s (use 5000 Km, and 7.55 m2 / s (use 10000 Km.   Keywords: viscosity, oil, temperature

  8. Passive Standoff Super Resolution Imaging using Spatial-Spectral Multiplexing (United States)


    COMSOL simulations to demonstrate the effect of finite aperture size on the angular filter. 6.2.1 RCWA Simulations of 2D Patterned Sub-wavelength...lithography if needed. Fig. 136. Angular filter schematic. 6.4.3 COMSOL Simulations COMSOL was utilized to simulate the grating. However, results

  9. Spectral stratigraphy (United States)

    Lang, Harold R.


    A new approach to stratigraphic analysis is described which uses photogeologic and spectral interpretation of multispectral remote sensing data combined with topographic information to determine the attitude, thickness, and lithology of strata exposed at the surface. The new stratigraphic procedure is illustrated by examples in the literature. The published results demonstrate the potential of spectral stratigraphy for mapping strata, determining dip and strike, measuring and correlating stratigraphic sequences, defining lithofacies, mapping biofacies, and interpreting geological structures.


    NARCIS (Netherlands)



    A new viscosity equation for the description of the viscosity of concentrated aqueous starch pastes is proposed: eta(app) = Ke([Bmstarch+(C/T)-DW+(n-1)ln gamma]) with: m(starch) = mass fraction starch in paste, T = temperature, W = amount of work performed on the starch, n = power-law index, K =

  11. Haptic Discrimination and Matching of Viscosity

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Vrijling, A.C.L.; Kappers, A.M.L.


    In three experiments, viscosity perception of liquids using the sense of touch was studied. The first two were discrimination experiments in which Weber fractions were determined for a number of viscosities spanning the range of what is encountered in daily life, and for two ways of perceiving

  12. Viscosity: From air to hot nuclei

    Indian Academy of Sciences (India)


    Oct 9, 2014 ... After a brief review of the history of viscosity from classical to quantal fluids, a discussion of how the shear viscosity of a finite hot nucleus is calculated directly from the width and energy of the giant dipole resonance (GDR) of the nucleus is given in this paper. The ratio / with s being the entropy volume ...

  13. Viscosity evolution of anaerobic granular sludge

    NARCIS (Netherlands)

    Pevere, A.; Guibaud, G.; Hullebusch, van E.D.; Lens, P.N.L.; Baudu, M.


    The evolution of the apparent viscosity at steady shear rate of sieved anaerobic granular sludge (20¿315 ¿m diameter) sampled from different full-scale anaerobic reactors was recorded using rotation tests. The ¿limit viscosity¿ of sieved anaerobic granular sludge was determined from the apparent

  14. Reducing blood viscosity with magnetic fields. (United States)

    Tao, R; Huang, K


    Blood viscosity is a major factor in heart disease. When blood viscosity increases, it damages blood vessels and increases the risk of heart attacks. Currently, the only method of treatment is to take drugs such as aspirin, which has, however, several unwanted side effects. Here we report our finding that blood viscosity can be reduced with magnetic fields of 1 T or above in the blood flow direction. One magnetic field pulse of 1.3 T lasting ~1 min can reduce the blood viscosity by 20%-30%. After the exposure, in the absence of magnetic field, the blood viscosity slowly moves up, but takes a couple of hours to return to the original value. The process is repeatable. Reapplying the magnetic field reduces the blood viscosity again. By selecting the magnetic field strength and duration, we can keep the blood viscosity within the normal range. In addition, such viscosity reduction does not affect the red blood cells' normal function. This technology has much potential for physical therapy.

  15. History and Super Diversity

    Directory of Open Access Journals (Sweden)

    Kate Hawkey


    Full Text Available The article looks at the perspectives on history amongst adolescent children of different backgrounds living in inner-cities in England and builds on previous research in this area. The current article presents exploratory research which focuses on the views of particular groups of adolescents, namely those from long established settled immigrant communities; those from more recently arrived migrant and immigrant communities; and those from white indigenous communities. An inclusive, perspectival and dynamic approach towards history education is outlined and the underlying view of knowledge and implications for pedagogy of this approach discussed alongside comparisons with other approaches towards the subject. The exploratory work and analysis is used to generate a research agenda through which history for a super diverse society can be developed. Although the research was conducted in the English context, the issues it raises are pertinent elsewhere.

  16. The Super DREAM Project

    Energy Technology Data Exchange (ETDEWEB)

    Wigmans, Richard [Texas Tech Univ., Lubbock, TX (United States)


    Despite the fact that DOE provided only a fraction of the requested funds, the goals we defined in the proposal on which award ER41783 was based were essentially all met. This was partially due to the fact that other funding agencies, which supported our collaborators (especially from Italy and Korea) contributed as well, and partially due to the effective solutions that were developed to compensate for the fact that the detector we had proposed to build had to be scaled down. The performance of the SuperDREAM calorimeter is better than anything that has been built or proposed so far. This has of course not gone unnoticed in the scientific community. Scientists who are preparing experiments for the proposed new generation of particle accelerators (FCCee, CPEC,..) are all very seriously considering the technology developed in this project. Several new collaborations have formed which aim to adapt the dual-readout calorimeter principles to the demands of a 4 environment. Preliminary measurements using silicon photomultipliers as light sensors have already been carried out. This type of readout would make it possible to operate this detector in a magnetic field, and it would also allow for a longitudinal segmentation into electromagnetic and hadronic sections, if so desired. In addition, SiPM readout would eliminate the need for “forests” of fibers sticking out of the rear end of the calorimeter (Figure 1), and obtain an arbitrary fine lateral segmentation, which might be very important for recognizing electrons inside jets. The improvements in our understanding of the fundamental structure of matter and the forces that govern its behavior have always hinged on the availability of detectors that make it possible to explore the possibilities of new, more powerful particle accelerators to the fullest extent. We believe that the SuperDREAM project has created a quantum leap in detector technology, which may turn out to be crucially important for future discoveries in

  17. Viscosity of Common Seed and Vegetable Oils (United States)

    Wes Fountain, C.; Jennings, Jeanne; McKie, Cheryl K.; Oakman, Patrice; Fetterolf, Monty L.


    Viscosity experiments using Ostwald-type gravity flow viscometers are not new to the physical chemistry laboratory. Several physical chemistry laboratory texts (1 - 3) contain at least one experiment studying polymer solutions or other well-defined systems. Several recently published articles (4 - 8) indicated the continued interest in using viscosity measurements in the teaching lab to illustrate molecular interpretation of bulk phenomena. Most of these discussions and teaching experiments are designed around an extensive theory of viscous flow and models of molecular shape that allow a full data interpretation to be attempted. This approach to viscosity experiments may not be appropriate for all teaching situations (e.g., high schools, general chemistry labs, and nonmajor physical chemistry labs). A viscosity experiment is presented here that is designed around common seed and vegetable oils. With the importance of viscosity to foodstuffs (9) and the importance of fatty acids to nutrition (10), an experiment using these common, recognizable oils has broad appeal.

  18. Odd viscosity in chiral active fluids. (United States)

    Banerjee, Debarghya; Souslov, Anton; Abanov, Alexander G; Vitelli, Vincenzo


    We study the hydrodynamics of fluids composed of self-spinning objects such as chiral grains or colloidal particles subject to torques. These chiral active fluids break both parity and time-reversal symmetries in their non-equilibrium steady states. As a result, the constitutive relations of chiral active media display a dissipationless linear-response coefficient called odd (or equivalently, Hall) viscosity. This odd viscosity does not lead to energy dissipation, but gives rise to a flow perpendicular to applied pressure. We show how odd viscosity arises from non-linear equations of hydrodynamics with rotational degrees of freedom, once linearized around a non-equilibrium steady state characterized by large spinning speeds. Next, we explore odd viscosity in compressible fluids and suggest how our findings can be tested in the context of shock propagation experiments. Finally, we show how odd viscosity in weakly compressible chiral active fluids can lead to density and pressure excess within vortex cores.

  19. The Friction Theory for Viscosity Modeling

    DEFF Research Database (Denmark)

    Cisneros, Sergio; Zeberg-Mikkelsen, Claus Kjær; Stenby, Erling Halfdan


    In this work the one-parameter friction theory (f-theory) general models have been extended to the viscosity prediction and modeling of characterized oils. It is demonstrated that these simple models, which take advantage of the repulsive and attractive pressure terms of cubic equations of state...... such as the SRK, PR and PRSV, can provide accurate viscosity prediction and modeling of characterized oils. In the case of light reservoir oils, whose properties are close to those of normal alkanes, the one-parameter f-theory general models can predict the viscosity of these fluids with good accuracy. Yet......, in the case when experimental information is available a more accurate modeling can be obtained by means of a simple tuning procedure. A tuned f-theory general model can deliver highly accurate viscosity modeling above the saturation pressure and good prediction of the liquid-phase viscosity at pressures...

  20. Plasma viscosity elevations with simulated weightlessness (United States)

    Martin, D. G.; Convertino, V. A.; Goldwater, D.; Ferguson, E. W.; Schoomaker, E. B.


    A hypothesis correlating an increase in blood viscosity during bed rest to a decrease in aerobic capacity during simulated weightlessness is tested. Eight human subjects were studied on the sixth day of bed rest during two consecutive 10-d bed rest periods separated by a 14-d recovery interval designed to simulate the flight-layover schedule of Shuttle astronauts. Plasma viscosity and volume were measured, together with maximal aerobic capacity (VO2max). An increase in hematocrit, plasma protein, and fibrinogen concentrations was found, contributing to an elevation in plasma viscosity. VO2max decreased significantly in the first, but not the second bed rest cycle, and though many individuals exhibited a decrease in plasma volume and aerobic capacity coupled with elevated plasma viscosity, correlations between these variables were lacking. It is concluded that the decrease in VO2max observed following simulated weightlessness cannot be attributed to alterations in muscle blood flow resulting from increased blood viscosity.

  1. The viscosity measurement of molten rocks

    Directory of Open Access Journals (Sweden)

    Rybár Pavol


    Full Text Available This paper deals with the viscosity measurtement of molten rocks. The reason of such investigation was due to the solving of SC No. 95/135/059 LITHO-JET. Technology of thermic rock melting for trenching of tenous vertical works. One task in the scope of above investigation was to experimentally verify the properties of melts of various types of works. An important moment in the trenching of tenuous vertical works by rock melting is the ability of melt to penetrate into the rock cracks. From this point of view an important physical property of molten rock is its viscosity. There are various methods how to measure viscosity but for the continuous measurements just some of them are suitable. The most suitable is rotary viscosimeter because it is simple in its construction, it allows to measure the viscosity as a function of temperature, concentration of wide class of sub stances with different rheologic properties. Hence, it allows to measure structural viscosity of the chemical reaction systems. The viscosity of molten nefelitic basanite as the function of temperature is studied in this paper. Viscosity of the nefelinitic basanite taken at locality Konrádovce was measured using rotary viscosimeter HAAKE ROTOVISKO. Eperimental conditions shown, that rising of the temperature vs. viscosity is in reverse order. Measurement is realised in scale 1370-1550°C. Under 1370°C was sample very viscous and measurement was impossible. Viscosity is the function of the temperature, pressure and gas components of rock.Though the viscosity measurements was carried out at atmospheric pressure, what does not fully conform real condition during trenching, it is still possible to express the effect of pressure. Other conditions, which take effect of viscosityof molten rocks in nature conditions will be subject of future investigation.

  2. Renormalization-group theory for the eddy viscosity in subgrid modeling (United States)

    Zhou, YE; Vahala, George; Hossain, Murshed


    Renormalization-group theory is applied to incompressible three-dimensional Navier-Stokes turbulence so as to eliminate unresolvable small scales. The renormalized Navier-Stokes equation now includes a triple nonlinearity with the eddy viscosity exhibiting a mild cusp behavior, in qualitative agreement with the test-field model results of Kraichnan. For the cusp behavior to arise, not only is the triple nonlinearity necessary but the effects of pressure must be incorporated in the triple term. The renormalized eddy viscosity will not exhibit a cusp behavior if it is assumed that a spectral gap exists between the large and small scales.

  3. Einstein viscosity with fluid elasticity (United States)

    Einarsson, Jonas; Yang, Mengfei; Shaqfeh, Eric S. G.


    We give the first correction to the suspension viscosity due to fluid elasticity for a dilute suspension of spheres in a viscoelastic medium. Our perturbation theory is valid to O (ϕ Wi2) in the particle volume fraction ϕ and the Weissenberg number Wi =γ ˙λ , where γ ˙ is the typical magnitude of the suspension velocity gradient, and λ is the relaxation time of the viscoelastic fluid. For shear flow we find that the suspension shear-thickens due to elastic stretching in strain "hot spots" near the particle, despite the fact that the stress inside the particles decreases relative to the Newtonian case. We thus argue that it is crucial to correctly model the extensional rheology of the suspending medium to predict the shear rheology of the suspension. For uniaxial extensional flow we correct existing results at O (ϕ Wi ) , and find dramatic strain-rate thickening at O (ϕ Wi2) . We validate our theory with fully resolved numerical simulations.

  4. SuperB Progress Report: Detector

    Energy Technology Data Exchange (ETDEWEB)

    Grauges, E.; /Barcelona U., ECM; Donvito, G.; Spinoso, V.; /INFN, Bari /Bari U.; Manghisoni, M.; Re, V.; Traversi, G.; /INFN, Pavia /Bergamo U., Ingengneria Dept.; Eigen, G.; Fehlker, D.; Helleve, L.; /Bergen U.; Carbone, A.; Di Sipio, R.; Gabrielli, A.; Galli, D.; Giorgi, F.; Marconi, U.; Perazzini, S.; Sbarra, C.; Vagnoni, V.; Valentinetti, S.; Villa, M.; Zoccoli, A.; /INFN, Bologna /Bologna U. /Caltech /Carleton U. /Cincinnati U. /INFN, CNAF /INFN, Ferrara /Ferrara U. /UC, Irvine /Taras Shevchenko U. /Orsay, LAL /LBL, Berkeley /UC, Berkeley /Frascati /INFN, Legnaro /Orsay, IPN /Maryland U. /McGill U. /INFN, Milan /Milan U. /INFN, Naples /Naples U. /Novosibirsk, IYF /INFN, Padua /Padua U. /INFN, Pavia /Pavia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Caltech /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore /PNL, Richland /Queen Mary, U. of London /Rutherford /INFN, Rome /Rome U. /INFN, Rome2 /Rome U.,Tor Vergata /INFN, Rome3 /Rome III U. /SLAC /Tel Aviv U. /INFN, Turin /Turin U. /INFN, Padua /Trento U. /INFN, Trieste /Trieste U. /TRIUMF /British Columbia U. /Montreal U. /Victoria U.


    This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  5. Comparative evaluation of aqueous humor viscosity. (United States)

    Davis, Kyshia; Carter, Renee; Tully, Thomas; Negulescu, Ioan; Storey, Eric


    To evaluate aqueous humor viscosity in the raptor, dog, cat, and horse, with a primary focus on the barred owl (Strix varia). Twenty-six raptors, ten dogs, three cats, and one horse. Animals were euthanized for reasons unrelated to this study. Immediately, after horizontal and vertical corneal dimensions were measured, and anterior chamber paracentesis was performed to quantify anterior chamber volume and obtain aqueous humor samples for viscosity analysis. Dynamic aqueous humor viscosity was measured using a dynamic shear rheometer (AR 1000 TA Instruments, New Castle, DE, USA) at 20 °C. Statistical analysis included descriptive statistics, unpaired t-tests, and Tukey's test to evaluate the mean ± standard deviation for corneal diameter, anterior chamber volume, and aqueous humor viscosity amongst groups and calculation of Spearman's coefficient for correlation analyses. The mean aqueous humor viscosity in the barred owl was 14.1 centipoise (cP) ± 9, cat 4.4 cP ± 0.2, and dog 2.9 cP ± 1.3. The aqueous humor viscosity for the horse was 1 cP. Of the animals evaluated in this study, the raptor aqueous humor was the most viscous. The aqueous humor of the barred owl is significantly more viscous than the dog (P humor viscosity of the raptor, dog, cat, and horse can be successfully determined using a dynamic shear rheometer. © 2014 American College of Veterinary Ophthalmologists.

  6. Thermo-super-hydrophobic effect (United States)

    Floryan, Jerzy M.


    Super-hydrophobic effect involves capture of gas bubbles in pores of solid wall. These bubbles separate moving liquid from the solid surface resulting in a substantial reduction of shear drag experienced by the liquid. The super-hydrophobic effect requires presence of two phases and thus drag reduction can be accomplished only for liquids. Thermo-super-hydrophobic effect takes advantage of the localized heating to create separation bubbles and thus can work with single phase flow systems. Analysis of a simple model problem shows that this effect is very strong in the case of small Re flows such as those found in micro-channels and can reduce pressure drop down to 50% of the reference value if the heating pattern as well as the heating intensity are suitable chosen. The thermo-super-hydrophobic effect becomes marginal when Re increases above a certain critical value.

  7. The extension of radiative viscosity to superfluid matter


    Pi, Chun-Mei; Yang, Shu-Hua; Zheng, Xiao-Ping


    The radiative viscosity of superfluid $npe$ matter is studied, and it is found that to the lowest order of $\\delta \\mu/T$ the ratio of radiative viscosity to bulk viscosity is the same as that of the normal matter.

  8. Shear viscosity of liquid mixtures Mass dependence

    CERN Document Server

    Kaushal, R


    Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model.

  9. Intrinsic viscosity of a suspension of cubes

    KAUST Repository

    Mallavajula, Rajesh K.


    We report on the viscosity of a dilute suspension of cube-shaped particles. Irrespective of the particle size, size distribution, and surface chemistry, we find empirically that cubes manifest an intrinsic viscosity [η]=3.1±0.2, which is substantially higher than the well-known value for spheres, [η]=2.5. The orientation-dependent intrinsic viscosity of cubic particles is determined theoretically using a finite-element solution of the Stokes equations. For isotropically oriented cubes, these calculations show [η]=3.1, in excellent agreement with our experimental observations. © 2013 American Physical Society.

  10. Viscosity studies of water based magnetite nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Anu, K.; Hemalatha, J. [Advanced Materials Lab, Department of Physics, National Institute of Technology, Tiruchirappalli, Tamilnadu, India – 620015 (India)


    Magnetite nanofluids of various concentrations have been synthesized through co-precipitation method. The structural and topographical studies made with the X-Ray Diffractometer and Atomic Force Microscope are presented in this paper. The density and viscosity studies for the ferrofluids of various concentrations have been made at room temperature. The experimental viscosities are compared with theoretical values obtained from Einstein, Batchelor and Wang models. An attempt to modify the Rosensweig model is made and the modified Rosensweig equation is reported. In addition, new empirical correlation is also proposed for predicting viscosity of ferrofluid at various concentrations.

  11. Laboratory Tests for Dispersive Soil Viscosity Determining (United States)

    Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Sobolev, E. S.


    There are several widespread methods for soil viscosity determining now. The standard shear test device and torsion test apparatus are the most commonly used installations to do that. However, the application of them has a number of disadvantages. Therefore, the specialists of Moscow State University of Civil Engineering proposed a new device to determine the disperse soil viscosity on the basis of a stabilometer with the B-type camera (viscosimeter). The paper considers the construction of a viscosimeter and the technique for determining soil viscosity inside this tool as well as some experimental verification results of its work.

  12. A possible mechanism to detect super-earth formation in protoplanetary disks (United States)

    Dong, Ruobing; Chiang, Eugene; Li, Hui; Li, Shengtai


    Using combined gas+dust global hydrodynamics and radiative transfer simulations, we calculate the distribution of gas and sub-mm-sized dust in protoplanetary disks with a super-Earth at tens of AU, and examine observational signatures of such systems in resolved observations. We confirm previous results that in a typical disk with a low viscosity ($\\alpha\\lesssim10^{-4}$), a super-Earth is able to open two gaps at $\\sim$scale-height away around its orbit in $\\sim$mm-sized dust (St$\\sim$0.01), due to differential dust drift in a perturbed gas background. Additional rings and gaps may also be produced under certain conditions. These features, particularly a signature ``double-gap'' feature, can be detected in a Taurus target by ALMA in dust continuum under an angular resolution of $\\sim0\\arcsec.025$ with two hours of integration. The features are robust --- it can survive in a variety of background disk profiles, withstand modest planetary radial migration ($|r/\\dot{r}|\\sim$ a few Myr), and last for thousands of orbits. Multiple ring/gap systems observed by ALMA were typically modeled using multiple (Saturn-to-Jupiter sized) planets. Here, we argue that a single super-Earth in a low viscosity disk could produce multiple rings and gaps as well. By examining the prevalence of such features in nearby disks, upcoming high angular resolution ALMA surveys may infer how common super-Earth formation events are at tens of au.

  13. Quartz resonator fluid density and viscosity monitor (United States)

    Martin, Stephen J.; Wiczer, James J.; Cernosek, Richard W.; Frye, Gregory C.; Gebert, Charles T.; Casaus, Leonard; Mitchell, Mary A.


    A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

  14. A Simple BODIPY-Based Viscosity Probe for Imaging of Cellular Viscosity in Live Cells

    Directory of Open Access Journals (Sweden)

    Dongdong Su


    Full Text Available Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited a significant fluorescence intensity enhancement of more than 100-fold as the solvent viscosity increased. Also, the probe showed a direct linear relationship between the fluorescence lifetime and the media viscosity, which makes it possible to trace the change of the medium viscosity. Furthermore, it was demonstrated that BTV could achieve practical applicability in the monitoring of mitochondrial viscosity changes in live cells through fluorescence lifetime imaging microscopy (FLIM.

  15. A Simple BODIPY-Based Viscosity Probe for Imaging of Cellular Viscosity in Live Cells (United States)

    Su, Dongdong; Teoh, Chai Lean; Gao, Nengyue; Xu, Qing-Hua; Chang, Young-Tae


    Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY)-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited a significant fluorescence intensity enhancement of more than 100-fold as the solvent viscosity increased. Also, the probe showed a direct linear relationship between the fluorescence lifetime and the media viscosity, which makes it possible to trace the change of the medium viscosity. Furthermore, it was demonstrated that BTV could achieve practical applicability in the monitoring of mitochondrial viscosity changes in live cells through fluorescence lifetime imaging microscopy (FLIM). PMID:27589762

  16. Intrinsic viscosity of actively swimming microalgae suspensions (United States)

    Ewoldt, Randy; Caretta, Lucas; Chengala, Anwar; Sheng, Jian


    Suspensions of actively swimming microorganisms exhibit an effective viscosity which may depend on volume fraction, cell shape, and the nature of locomotion (e.g. ``pushers'' vs. ``pullers''). Although several dilute-regime theories have been offered for active suspensions, no experimental study to our knowledge has been able to resolve the dilute-regime intrinsic viscosity of actively swimming microorganism suspensions. Here we use a cone-and-plate rheometer to experimentally measure the dynamic shear viscosity for motile and non-motile suspensions of unicellular green algae (Dunaliella primolecta, a biflagellated ``puller''). The low viscosity biological samples require careful experimental protocols to avoid settling and flow-induced migration, and to minimize precision error. With these protocols in place we can distinguish the intrinsic viscosity which we show is higher for the motile ``puller'' swimmers compared to the immobilized counterparts. This observation is consistent with recently proposed dilute-regime theories which predict that ``pullers'' should have a higher viscosity than non-motile suspensions.

  17. Super Dielectric Materials (United States)

    Fromille, Samuel; Phillips, Jonathan


    Evidence is provided here that a class of materials with dielectric constants greater than 105 at low frequency (dielectric materials (SDM), can be generated readily from common, inexpensive materials. Specifically it is demonstrated that high surface area alumina powders, loaded to the incipient wetness point with a solution of boric acid dissolved in water, have dielectric constants, near 0 Hz, greater than 4 × 108 in all cases, a remarkable increase over the best dielectric constants previously measured for energy storage capabilities, ca. 1 × 104. It is postulated that any porous, electrically insulating material (e.g., high surface area powders of silica, titania, etc.), filled with a liquid containing a high concentration of ionic species will potentially be an SDM. Capacitors created with the first generated SDM dielectrics (alumina with boric acid solution), herein called New Paradigm Super (NPS) capacitors display typical electrostatic capacitive behavior, such as increasing capacitance with decreasing thickness, and can be cycled, but are limited to a maximum effective operating voltage of about 0.8 V. A simple theory is presented: Water containing relatively high concentrations of dissolved ions saturates all, or virtually all, the pores (average diameter 500 Å) of the alumina. In an applied field the positive ionic species migrate to the cathode end, and the negative ions to the anode end of each drop. This creates giant dipoles with high charge, hence leading to high dielectric constant behavior. At about 0.8 V, water begins to break down, creating enough ionic species to “short” the individual water droplets. Potentially NPS capacitor stacks can surpass “supercapacitors” in volumetric energy density. PMID:28788298

  18. All-optical OFDM demultiplexing by spectral magnification and band-pass filtering. (United States)

    Palushani, E; Mulvad, H C Hansen; Kong, D; Guan, P; Galili, M; Oxenløwe, L K


    We propose a simple OFDM receiver allowing for the use of standard WDM receivers to receive spectrally advanced OFDM signals. We propose to spectrally magnify the optical-OFDM super-channels using a spectral telescope consisting of two time-lenses, which enables reduced inter-carrier-interference in subcarrier detection by simple band-pass filtering. A demonstration on an emulated 100 Gbit/s DPSK optical-OFDM channel shows improved sensitivities after 4-times spectral magnification.

  19. All-optical OFDM demultiplexing by spectral magnification and band-pass filtering

    DEFF Research Database (Denmark)

    Palushani, Evarist; Mulvad, Hans Christian Hansen; Kong, Deming


    We propose a simple OFDM receiver allowing for the use of standard WDM receivers to receive spectrally advanced OFDM signals. We propose to spectrally magnify the optical-OFDM super-channels using a spectral telescope consisting of two time-lenses, which enables reduced inter......-carrier-interference in subcarrier detection by simple band-pass filtering. A demonstration on an emulated 100 Gbit/s DPSK optical-OFDM channel shows improved sensitivities after 4-times spectral magnification....

  20. Spectral Predictors

    Energy Technology Data Exchange (ETDEWEB)

    Ibarria, L; Lindstrom, P; Rossignac, J


    Many scientific, imaging, and geospatial applications produce large high-precision scalar fields sampled on a regular grid. Lossless compression of such data is commonly done using predictive coding, in which weighted combinations of previously coded samples known to both encoder and decoder are used to predict subsequent nearby samples. In hierarchical, incremental, or selective transmission, the spatial pattern of the known neighbors is often irregular and varies from one sample to the next, which precludes prediction based on a single stencil and fixed set of weights. To handle such situations and make the best use of available neighboring samples, we propose a local spectral predictor that offers optimal prediction by tailoring the weights to each configuration of known nearby samples. These weights may be precomputed and stored in a small lookup table. We show that predictive coding using our spectral predictor improves compression for various sources of high-precision data.

  1. Optovibrometry: tracking changes in the surface tension and viscosity of multicomponent droplets in real-time. (United States)

    Harrold, Victoria C; Sharp, James S


    An instrument was developed for measuring real time changes in the surface tension and viscosity of multicomponent droplets of miscible liquids and other soft materials. Droplets containing glycerol and water were supported on superamphiphobic surfaces and vibrated by applying a short mechanical impulse. Laser light was refracted through the droplets and allowed to fall on the surface of a photodiode. Time dependent variations in the intensity measured by the photodiode during vibration were used to monitor the decay of the droplet oscillations. The frequencies and spectral widths of the droplet vibrational resonances were then obtained from Fourier transforms of these time dependent intensity signals. A recently developed model of viscoelastic droplet vibration was used along with these values and measurements of the drop dimensions to extract the surface tension and viscosity of the drops as they evaporated. Collection of data was automated and values of frequency, spectral width, drop size, surface tension and viscosity were obtained with a time resolution of three seconds over a period of thirty minutes. The values of surface tension and viscosity obtained were shown to be in good agreement with literature values obtained from bulk glycerol/water solutions; thus validating the technique for wider application to other multicomponent liquids and soft matter systems.

  2. Spectral element simulation of ultrafiltration

    DEFF Research Database (Denmark)

    Hansen, M.; Barker, Vincent A.; Hassager, Ole


    A spectral element method for simulating stationary 2-D ultrafiltration is presented. The mathematical model is comprised of the Navier-Stokes equations for the velocity field of the fluid and a transport equation for the concentration of the solute. In addition to the presence of the velocity ve....... The performance of the spectral element code when applied to several ultrafiltration problems is reported. (C) 1998 Elsevier Science Ltd. All rights reserved.......A spectral element method for simulating stationary 2-D ultrafiltration is presented. The mathematical model is comprised of the Navier-Stokes equations for the velocity field of the fluid and a transport equation for the concentration of the solute. In addition to the presence of the velocity...... vector in the transport equation, the system is coupled by the dependency of the fluid viscosity on the solute concentration and by a concentration-dependent boundary condition for the Navier-Stokes equations at the membrane surface. The spectral element discretization yields a nonlinear algebraic system...

  3. Quantization of super Teichmueller spaces

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Nezhla


    The quantization of the Teichmueller spaces of Riemann surfaces has found important applications to conformal field theory and N=2 supersymmetric gauge theories. We construct a quantization of the Teichmueller spaces of super Riemann surfaces, using coordinates associated to the ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. We construct a projective unitary representation of the groupoid of changes of refined ideal triangulations. Therefore, we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential. In the quantum Teichmueller theory, it was observed that the key object defining the Teichmueller theory has a close relation to the representation theory of the Borel half of U{sub q}(sl(2)). In our research we observed that the role of U{sub q}(sl(2)) is taken by quantum superalgebra U{sub q}(osp(1 vertical stroke 2)). A Borel half of U{sub q}(osp(1 vertical stroke 2)) is the super quantum plane. The canonical element of the Heisenberg double of the quantum super plane is evaluated in certain infinite dimensional representations on L{sup 2}(R) x C{sup 1} {sup vertical} {sup stroke} {sup 1} and compared to the flip operator from the Teichmueller theory of super Riemann surfaces.

  4. APES-based procedure for super-resolution SAR imagery with GPU parallel computing (United States)

    Jia, Weiwei; Xu, Xiaojian; Xu, Guangyao


    The amplitude and phase estimation (APES) algorithm is widely used in modern spectral analysis. Compared with conventional Fourier transform (FFT), APES results in lower sidelobes and narrower spectral peaks. However, in synthetic aperture radar (SAR) imaging with large scene, without parallel computation, it is difficult to apply APES directly to super-resolution radar image processing due to its great amount of calculation. In this paper, a procedure is proposed to achieve target extraction and parallel computing of APES for super-resolution SAR imaging. Numerical experimental are carried out on Tesla K40C with 745 MHz GPU clock rate and 2880 CUDA cores. Results of SAR image with GPU parallel computing show that the parallel APES is remarkably more efficient than that of CPU-based with the same super-resolution.

  5. Perspectives in Super-resolved Fluorescence Microscopy: What comes next?

    Directory of Open Access Journals (Sweden)

    Christoph eCremer


    Full Text Available The Nobel Prize in Chemistry 2014 has been awarded to three scientists involved in the development of STED and PALM super-resolution fluorescence microscopy (SRM methods. They have proven that it is possible to overcome the hundred year old theoretical limit for the resolution potential of light microscopy (of about 200 nm for visible light, which for decades has precluded a direct glimpse of the molecular machinery of life. None of the present-day super-resolution techniques have invalidated the Abbe limit for light optical detection; however, they have found clever ways around it. In this report, we discuss some of the challenges still to be resolved before arising SRM approaches will be fit to bring about the revolution in Biology and Medicine envisaged. Some of the challenges discussed are the applicability to image live and/or large samples, the further enhancement of resolution, future developments of labels, and multi-spectral approaches.

  6. Entropy Viscosity Method for High-Order Approximations of Conservation Laws

    KAUST Repository

    Guermond, J. L.


    A stabilization technique for conservation laws is presented. It introduces in the governing equations a nonlinear dissipation function of the residual of the associated entropy equation and bounded from above by a first order viscous term. Different two-dimensional test cases are simulated - a 2D Burgers problem, the "KPP rotating wave" and the Euler system - using high order methods: spectral elements or Fourier expansions. Details on the tuning of the parameters controlling the entropy viscosity are given. © 2011 Springer.

  7. Viscosity of Xenon Examined in Microgravity (United States)

    Zimmerli, Gregory A.; Berg, Robert F.; Moldover, Michael R.


    Why does water flow faster than honey? The short answer, that honey has a greater viscosity, merely rephrases the question. The fundamental answer is that viscosity originates in the interactions between a fluid s molecules. These interactions are so complicated that, except for low-density gases, the viscosity of a fluid cannot be accurately predicted. Progress in understanding viscosity has been made by studying moderately dense gases and, more recently, fluids near the critical point. Modern theories predict a universal behavior for all pure fluids near the liquid-vapor critical point, and they relate the increase in viscosity to spontaneous fluctuations in density near this point. The Critical Viscosity of Xenon (CVX) experiment tested these theories with unprecedented precision when it flew aboard the Space Shuttle Discovery (STS-85) in August 1997. Near the critical point, xenon is a billion times more compressible than water, yet it has about the same density. Because the fluid is so "soft," it collapses under its own weight when exposed to the force of Earth s gravity - much like a very soft spring. Because the CVX experiment is conducted in microgravity, it achieves a very uniform fluid density even very close to the critical point. At the heart of the CVX experiment is a novel viscometer built around a small nickel screen. An oscillating electric field forces the screen to oscillate between pairs of electrodes. Viscosity, which dampens the oscillations, can be calculated by measuring the screen motion and the force applied to the screen. So that the fluid s delicate state near the critical point will not be disrupted, the screen oscillations are set to be both slow and small.

  8. Super-resolution microscopy with DNA-PAINT. (United States)

    Schnitzbauer, Joerg; Strauss, Maximilian T; Schlichthaerle, Thomas; Schueder, Florian; Jungmann, Ralf


    Super-resolution techniques have begun to transform biological and biomedical research by allowing researchers to observe structures well below the classic diffraction limit of light. DNA points accumulation for imaging in nanoscale topography (DNA-PAINT) offers an easy-to-implement approach to localization-based super-resolution microscopy, owing to the use of DNA probes. In DNA-PAINT, transient binding of short dye-labeled ('imager') oligonucleotides to their complementary target ('docking') strands creates the necessary 'blinking' to enable stochastic super-resolution microscopy. Using the programmability and specificity of DNA molecules as imaging and labeling probes allows researchers to decouple blinking from dye photophysics, alleviating limitations of current super-resolution techniques, making them compatible with virtually any single-molecule-compatible dye. Recent developments in DNA-PAINT have enabled spectrally unlimited multiplexing, precise molecule counting and ultra-high, molecular-scale (sub-5-nm) spatial resolution, reaching ∼1-nm localization precision. DNA-PAINT can be applied to a multitude of in vitro and cellular applications by linking docking strands to antibodies. Here, we present a protocol for the key aspects of the DNA-PAINT framework for both novice and expert users. This protocol describes the creation of DNA origami test samples, in situ sample preparation, multiplexed data acquisition, data simulation, super-resolution image reconstruction and post-processing such as drift correction, molecule counting (qPAINT) and particle averaging. Moreover, we provide an integrated software package, named Picasso, for the computational steps involved. The protocol is designed to be modular, so that individual components can be chosen and implemented per requirements of a specific application. The procedure can be completed in 1-2 d.

  9. Quantisation of super Teichmueller theory

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Nezhla [DESY Hamburg (Germany). Theory Group; Hamburg Univ. (Germany). Dept. of Mathematics; Pawelkiewicz, Michal; Techner, Joerg [DESY Hamburg (Germany). Theory Group


    We construct a quantisation of the Teichmueller spaces of super Riemann surfaces using coordinates associated to ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. By constructing a projective unitary representation of the groupoid of changes of refined ideal triangulations we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential.

  10. Super- and Anti-Principal-Modes in Multimode Waveguides (United States)

    Ambichl, Philipp; Xiong, Wen; Bromberg, Yaron; Redding, Brandon; Cao, Hui; Rotter, Stefan


    We introduce special states for light in multimode waveguides featuring strongly enhanced or reduced spectral correlations in the presence of strong mode coupling. Based on the experimentally measured multispectral transmission matrix of a multimode fiber, we generate a set of states that outperform the established "principal modes" in terms of the spectral stability of their output spatial field profiles. Inverting this concept also allows us to create states with a minimal spectral correlation width, whose output profiles are considerably more sensitive to a frequency change than typical input wave fronts. The resulting "super-principal-modes" and "anti-principal-modes" are made orthogonal to each other even in the presence of mode-dependent loss. By decomposing them in the principal-mode basis, we show that the super-principal-modes are formed via interference of principal modes with close delay times, whereas the anti-principal-modes are a superposition of principal modes with the most-different delay times available in the fiber. Such novel states are expected to have broad applications in fiber communication, imaging, and spectroscopy.

  11. The shear viscosity in anisotropic phases

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Sachin [Department of Physics, Cornell University,Ithaca, New York 14853 (United States); Samanta, Rickmoy; Trivedi, Sandip P. [Department of Theoretical Physics, Tata Institute of Fundamental Research,Colaba, Mumbai 400005 (India)


    We construct anisotropic black brane solutions and analyse the behaviour of some of their metric perturbations. These solutions correspond to field theory duals in which rotational symmetry is broken due an externally applied, spatially constant, force. We find, in several examples, that when the anisotropy is sufficiently big compared to the temperature, some components of the viscosity tensor can become very small in units of the entropy density, parametrically violating the KSS bound. We obtain an expression relating these components of the viscosity, in units of the entropy density, to a ratio of metric components at the horizon of the black brane. This relation is generally valid, as long as the forcing function is translationally invariant, and it directly connects the parametric violation of the bound to the anisotropy in the metric at the horizon. Our results suggest the possibility that such small components of the viscosity tensor might also arise in anisotropic strongly coupled fluids found in nature.

  12. Polyfunctional dispersants for controlling viscosity of phyllosilicates (United States)

    Chaiko, David J.


    This invention provides phyllosilicates and polyfunctional dispersants which can be manipulated to selectively control the viscosity of phyllosilicate slurries. The polyfunctional dispersants used in the present invention, which include at least three functional groups, increase the dispersion and exfoliation of phyllosilicates in polymers and, when used in conjunction with phyllosilicate slurries, significantly reduce the viscosity of slurries having high concentrations of phyllosilicates. The functional groups of the polyfunctional dispersants are capable of associating with multivalent metal cations and low molecular weight organic polymers, which can be manipulated to substantially increase or decrease the viscosity of the slurry in a concentration dependent manner. The polyfunctional dispersants of the present invention can also impart desirable properties on the phyllosilicate dispersions including corrosion inhibition and enhanced exfoliation of the phyllosilicate platelets.

  13. Viscosity Meaurement Technique for Metal Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Ban, Heng [Utah State Univ., Logan, UT (United States). Mechanical and Aerospace Engineering; Kennedy, Rory [Idaho National Lab. (INL), Idaho Falls, ID (United States)


    Metallic fuels have exceptional transient behavior, excellent thermal conductivity, and a more straightforward reprocessing path, which does not separate out pure plutonium from the process stream. Fabrication of fuel containing minor actinides and rare earth (RE) elements for irradiation tests, for instance, U-20Pu-3Am-2Np-1.0RE-15Zr samples at the Idaho National Laboratory, is generally done by melt casting in an inert atmosphere. For the design of a casting system and further scale up development, computational modeling of the casting process is needed to provide information on melt flow and solidification for process optimization. Therefore, there is a need for melt viscosity data, the most important melt property that controls the melt flow. The goal of the project was to develop a measurement technique that uses fully sealed melt sample with no Americium vapor loss to determine the viscosity of metallic melts and at temperatures relevant to the casting process. The specific objectives of the project were to: develop mathematical models to establish the principle of the measurement method, design and build a viscosity measurement prototype system based on the established principle, and calibrate the system and quantify the uncertainty range. The result of the project indicates that the oscillation cup technique is applicable for melt viscosity measurement. Detailed mathematical models of innovative sample ampoule designs were developed to not only determine melt viscosity, but also melt density under certain designs. Measurement uncertainties were analyzed and quantified. The result of this project can be used as the initial step toward the eventual goal of establishing a viscosity measurement system for radioactive melts.

  14. Observation of super-resolution in digital breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Acciavatti, Raymond J.; Maidment, Andrew D. A. [Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104-4206 (United States)


    Purpose: Digital breast tomosynthesis (DBT) is a 3D x-ray imaging modality in which tomographic sections of the breast are generated from a limited range of tube angles. Because oblique x-ray incidence shifts the image of an object in subpixel detector element increments with each increasing projection angle, it is demonstrated that DBT is capable of super-resolution (i.e., subpixel resolution). Methods: By convention, DBT reconstructions are performed on planes parallel to the breast support at various depths of the breast volume. In order for resolution in each reconstructed slice to be comparable to the detector, the pixel size should match that of the detector elements; hence, the highest frequency that can be resolved in the plane of reconstruction is the alias frequency of the detector. This study considers reconstruction grids with much smaller pixelation to visualize higher frequencies. For analytical proof of super-resolution, a theoretical framework is developed in which the reconstruction of a high frequency sinusoidal input is calculated using both simple backprojection (SBP) and filtered backprojection. To study the frequency spectrum of the reconstruction, its Fourier transform is also determined. The experimental feasibility of super-resolution was investigated by acquiring images of a bar pattern phantom with frequencies higher than the detector alias frequency. Results: Using analytical modeling, it is shown that the central projection cannot resolve frequencies exceeding the detector alias frequency. The Fourier transform of the central projection is maximized at a lower frequency than the input as evidence of aliasing. By contrast, SBP reconstruction can resolve the input, and its Fourier transform is correctly maximized at the input frequency. Incorporating filters into the reconstruction smoothens pixelation artifacts in the spatial domain and reduces spectral leakage in the Fourier domain. It is also demonstrated that the existence of super

  15. Shear viscosity coefficient of liquid lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Patel, H. P., E-mail:; Thakor, P. B., E-mail:; Prajapati, A. V., E-mail: [Department of Physics, Veer Narmad South Gujarat University, Surat 395 007, Gujarat (India); Sonvane, Y. A., E-mail: [Department of Applied Physics, S. V. National Institute of Technology, Surat 395 007, Gujarat (India)


    Present paper deals with the computation of shear viscosity coefficient (η) of liquid lanthanides. The effective pair potential v(r) is calculated through our newly constructed model potential. The Pair distribution function g(r) is calculated from PYHS reference system. To see the influence of local field correction function, Hartree (H), Tailor (T) and Sarkar et al (S) local field correction function are used. Present results are compared with available experimental as well as theoretical data. Lastly, we found that our newly constructed model potential successfully explains the shear viscosity coefficient (η) of liquid lanthanides.

  16. Thermal relics in cosmology with bulk viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Iorio, A. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Lambiase, G. [Universita di Salerno, Dipartimento di Fisica E.R. Caianiello, Fisciano (Italy); INFN, Gruppo Collegato di Salerno, Fisciano (Italy)


    In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bulk viscosity) arising from different cooling rates of the fluid components in the expanding Universe. We discuss, in particular, the effects of the bulk viscosity on Big Bang Nucleosynthesis and on the thermal relic abundance of particles, looking at recent results of PAMELA experiment. The latter has determined an anomalous excess of positron events, which cannot be explained by conventional cosmology and particle physics. (orig.)

  17. Gravimetric capillary method for kinematic viscosity measurements (United States)

    Rosenberger, Franz; Iwan, J.; Alexander, D.; Jin, Wei-Qing


    A novel version of the capillary method for viscosity measurements of liquids is presented. Viscosity data can be deduced in a straightforward way from mass transfer data obtained by differential weighing during the gravity-induced flow of the liquid between two cylindrical chambers. Tests of this technique with water, carbon tetrachloride, and ethanol suggest that this arrangement provides an accuracy of about +/- 1 percent. The technique facilitates operation under sealed, isothermal conditions and, thus can readily be applied to reactive and/or high vapor pressure liquids.

  18. Super resolution volume rendering hardware

    NARCIS (Netherlands)

    Bosma, Marco; Smit, Jaap; Terwisscha van Scheltinga, Jeroen


    The resolution obtained in volume rendering is greatly increased over known methods through the introduction of super resolution techniques which make it possible to enlarge the view o f the dataset without the introduction of unnecessary positional, gradient and opacity errors. In this paper our

  19. Phase strength and super lattices

    Indian Academy of Sciences (India)


    Abstract. Powder XRD investigations on dotriacontane-decane and dotriacontane-decanol mixtures are made. Phase strength, phase separation and formation of superlattices are discussed. The role of tunnel-like defects is considered. Keywords. Hydrocarbons; mixtures; phase strength; tunnel-like defects; super lattices. 1.

  20. Super-resolution Phase Tomography

    KAUST Repository

    Depeursinge, Christian


    Digital Holographic Microscopy (DHM) yields reconstructed complex wavefields. It allows synthesizing the aperture of a virtual microscope up to 2π, offering super-resolution phase images. Live images of micro-organisms and neurons with resolution less than 100 nm are presented.

  1. Heat flux viscosity in collisional magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C., E-mail: [Princeton University, Princeton, New Jersey 08544 (United States); Fox, W. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Bhattacharjee, A. [Princeton University, Princeton, New Jersey 08544 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)


    Momentum transport in collisional magnetized plasmas due to gradients in the heat flux, a “heat flux viscosity,” is demonstrated. Even though no net particle flux is associated with a heat flux, in a plasma there can still be momentum transport owing to the velocity dependence of the Coulomb collision frequency, analogous to the thermal force. This heat-flux viscosity may play an important role in numerous plasma environments, in particular, in strongly driven high-energy-density plasma, where strong heat flux can dominate over ordinary plasma flows. The heat flux viscosity can influence the dynamics of the magnetic field in plasmas through the generalized Ohm's law and may therefore play an important role as a dissipation mechanism allowing magnetic field line reconnection. The heat flux viscosity is calculated directly using the finite-difference method of Epperlein and Haines [Phys. Fluids 29, 1029 (1986)], which is shown to be more accurate than Braginskii's method [S. I. Braginskii, Rev. Plasma Phys. 1, 205 (1965)], and confirmed with one-dimensional collisional particle-in-cell simulations. The resulting transport coefficients are tabulated for ease of application.

  2. Pressure-viscosity coefficient of biobased lubricants (United States)

    Film thickness is an important tribological property that is dependent on the combined effect of lubricant properties, material property of friction surfaces, and the operating conditions of the tribological process. Pressure-viscosity coefficient (PVC) is one of the lubricant properties that influe...

  3. Viscosity of endodontic irrigants: Influence of temperature

    Directory of Open Access Journals (Sweden)

    Claudio Poggio


    Full Text Available Background: The aim of this study was to assess the influence of temperature on the viscosity of different endodontic irrigants. Materials and Methods: The measurements of viscosity of 3% hydrogen peroxide, 0.9% sodium chloride, aqueous solution of 0.2% chlorhexidine (CHX and 0.2% cetrimide, 5% sodium hypochlorite (NaOCl and 17% ethylenediaminetetraacetic acid (EDTA at different temperatures (22°C, 30°C, 40°C, 50°C and 60°C were obtained using Mohr balance and Ostwald viscometer. The Shapiro-Wilk test and Mann-Whitney U-tests were used for the statistical analysis. (α = 0.05. Results: No significant differences were recorded at each temperature among 3% hydrogen peroxide, 0.9% sodium chloride and aqueous solution of 0.2% CHX and 0.2% cetrimide. 5% NaOCl and 17% EDTA showed the higher values. Viscosity statistically decreased with increasing temperature. Conclusion: Within the limitations of this study, 5% NaOCl and 17% EDTA are significantly viscous at room temperature and their viscosity reduces with elevating temperature.

  4. Effect of Viscosity on Liquid Curtain Stability (United States)

    Mohammad Karim, Alireza; Suszynski, Wieslaw; Francis, Lorraine; Carvalho, Marcio; Dow Chemical Company Collaboration; PUC Rio Collaboration; University of Minnesota, Twin Cities Collaboration


    The effect of viscosity on the stability of Newtonian liquid curtains was explored by high-speed visualization. Glycerol/water solutions with viscosity ranging from 19.1 to 210 mPa.s were used as coating liquids. The experimental set-up used a slide die delivery and steel tube edge guides. The velocity along curtain at different positions was measured by tracking small particles at different flow conditions. The measurements revealed that away from edge guides, velocity is well described by free fall effect. However, close to edge guides, liquid moves slower, revealing formation of a viscous boundary layer. The size of boundary layer and velocity near edge guides are strong function of viscosity. The critical condition was determined by examining flow rate below which curtain broke. Curtain failure was initiated by growth of a hole within liquid curtain, close to edge guides. Visualization results showed that the hole forms in a circular shape then becomes elliptical as it grows faster in vertical direction compared to horizontal direction. As viscosity rises, minimum flow rate for destabilization of curtain increased, indicating connection between interaction with edge guides and curtain stability. We would like to acknowledge the financial support from the Dow Chemical Company.

  5. Shear viscosity of an ordering latex suspension

    NARCIS (Netherlands)

    van der Vorst, A.M.; van der Vorst, B.; van den Ende, Henricus T.M.; Aelmans, N.J.J.; Mellema, J.


    The shear viscosity of a latex which is ordered at rest is studied as a function of the shear rate and volume fraction. At low shear rates and for moderate to high volume fractions, the flow curves show dynamic yield behavior which disappears below a volume fraction of 8%. At high shear rates, the

  6. Sensor for Viscosity and Shear Strength Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, J.; Moore, J.E. Jr.; Ebadian, M.A.; Jones, W.K.


    Measurement of the physical properties (viscosity and density) of waste slurries is critical in evaluating transport parameters to ensure turbulent flow through transport pipes. The environment for measurement and sensor exposure is extremely harsh; therefore, reliability and ruggedness are critical in the sensor design. The work for this project will be performed in three phases. The first phase, carried out in FY96, involved (1) an evaluation of acoustic and other methods for viscosity measurement; (2) measurement of the parameters of slurries over the range of percent solids found in tanks and transport systems; (3) a comparison of physical properties (e.g., viscosity and density) to percent solids found composition; and (4) the design of a prototype sensor. The second phase (FY97) will involve the fabrication of a prototype hybrid sensor to measure the viscosity and mechanical properties of slurries in remote, high-radiation environments. Two different viscometer designs are being investigated in this study: a magnetostrictive pulse wave guide viscometer; an oscillating cylinder viscometer. In FY97, the Hemispheric Center for Environmental Technology (HCET) at Florida International University (FIU), which has printed circuit, thick film, thin film, and co-fired ceramic fabrication capability, will fabricate five probes for demonstration after technology selection and evaluation.

  7. Spiders Tune Glue Viscosity to Maximize Adhesion. (United States)

    Amarpuri, Gaurav; Zhang, Ci; Diaz, Candido; Opell, Brent D; Blackledge, Todd A; Dhinojwala, Ali


    Adhesion in humid conditions is a fundamental challenge to both natural and synthetic adhesives. Yet, glue from most spider species becomes stickier as humidity increases. We find the adhesion of spider glue, from five diverse spider species, maximizes at very different humidities that matches their foraging habitats. By using high-speed imaging and spreading power law, we find that the glue viscosity varies over 5 orders of magnitude with humidity for each species, yet the viscosity at maximal adhesion for each species is nearly identical, 10(5)-10(6) cP. Many natural systems take advantage of viscosity to improve functional response, but spider glue's humidity responsiveness is a novel adaptation that makes the glue stickiest in each species' preferred habitat. This tuning is achieved by a combination of proteins and hygroscopic organic salts that determines water uptake in the glue. We therefore anticipate that manipulation of polymer-salts interaction to control viscosity can provide a simple mechanism to design humidity responsive smart adhesives.

  8. Quark Nova Signatures in Super-luminous Supernovae (United States)

    Kostka, M.; Koning, N.; Leahy, D.; Ouyed, R.; Steffen, W.


    Recent observational surveys have uncovered the existence of super-luminous supernovae (SLSNe). In this work we study the light curves of eight SLSNe in the context of dual-shock quark novae. We find that progenitor stars in the range of 25 - 35 M⊙ provide ample energy to power each light curve. An examination into the effects of varying the physical properties of a dual-shock quark nova on light curve composition is undertaken. We conclude that the wide variety of SLSN light curve morphologies can be explained predominantly by variations in the length of time between supernova and quark nova. Our analysis shows that a singular H alpha spectral profile found in three SLSNe can be naturally described in the dual-shock quark nova scenario. Predictions of spectral signatures unique to the dual-shock quark nova are presented.

  9. Super-strong Magnetic Field in Sunspots (United States)

    Okamoto, Takenori J.; Sakurai, Takashi


    Sunspots are the most notable structure on the solar surface with strong magnetic fields. The field is generally strongest in a dark area (umbra), but sometimes stronger fields are found in non-dark regions, such as a penumbra and a light bridge. The formation mechanism of such strong fields outside umbrae is still puzzling. Here we report clear evidence of the magnetic field of 6250 G, which is the strongest field among Stokes I profiles with clear Zeeman splitting ever observed on the Sun. The field was almost parallel to the solar surface and located in a bright region sandwiched by two opposite-polarity umbrae. Using a time series of spectral data sets, we discuss the formation process of the super-strong field and suggest that this strong field region was generated as a result of compression of one umbra pushed by the horizontal flow from the other umbra, such as the subduction of the Earth’s crust in plate tectonics.

  10. Effect of Ratio of Visco-Elastic Material Viscosity to Fluid Viscosity on Stability of Flexible Pipe Flow (United States)



    In the present study, a flexible pipe has been considered to study the effect of ratio of visco-elastic material viscosity to fluid viscosity on the stability of flexible laminar pipe flow with axi-symmetric disturbances. The effect of thickness of visco-elastic material on the stability of flexible pipe flow with outer rigid shroud has also been studied. The stability curves are drawn for various values of the ratio of visco-elastic material viscosity to fluid viscosity. It is observed that stability of flow is increasing by decreasing the ratio of visco-elastic material viscosity to fluid viscosity.

  11. Proceedings of RIKEN BNL Research Center Workshop: Understanding QGP through Spectral Functions and Euclidean Correlators (Volume 89)

    Energy Technology Data Exchange (ETDEWEB)

    Mocsy,A.; Petreczky, P.


    In the past two decades, one of the most important goals of the nuclear physics community has been the production and characterization of the new state of matter--Quark-Gluon Plasma (QGP). Understanding how properties of hadrons change in medium, particularly, the bound state of a very heavy quark and its antiquark, known as quarkonium, as well as determining the transport coefficients is crucial for identifying the properties of QGP and for the understanding of the experimental data from RHIC. On April 23rd, more than sixty physicists from twenty-seven institutions gathered for this three-day topical workshop held at BNL to discuss how to understand the properties of the new state of matter obtained in ultra-relativistic heavy ion collisions (particularly at RHIC-BNL) through spectral functions. In-medium properties of the different particle species and the transport properties of the medium are encoded in spectral functions. The former could yield important signatures of deconfinement and chiral symmetry restoration at high temperatures and densities, while the later are crucial for the understanding of the dynamics of ultra-relativistic heavy ion collisions. Participants at the workshop are experts in various areas of spectral function studies. The workshop encouraged direct exchange of scientific information among experts, as well as between the younger and the more established scientists. The workshops success is evident from the coherent picture that developed of the current understanding of transport properties and in-medium particle properties, illustrated in the current proceedings. The following pages show calculations of meson spectral functions in lattice QCD, as well as implications of these for quarkonia melting/survival in the quark gluon plasma; Lattice calculations of the transport coefficients (shear and bulk viscosities, electric conductivity); Calculation of spectral functions and transport coefficients in field theories using weak coupling

  12. Geometry Properties of Porosity Waves during Magma Migration: The Influence of Viscosities and Damage (United States)

    Cai, Z.; Bercovici, D.


    Partial melting occurs along grain boundaries and migrates through porous flow, leading to magma segregation in the mantle. Solitary porosity waves created by a perturbation in melting have been studied in the flow of a low viscosity fluid in a deformable matrix (McKenzie 1984, Scott and Stevenson 1986, Barcilon and Richter 1986, Spiegelman 1993, Wiggins and Spiegelman 1995). However, in a fairly complicated multi-physics, multi-scale process of magma migration, the geometry and instability of porosity waves can be affected by both mechanical and thermal factors, leaving different propagation signatures. In this work we develop a two-dimensional, two-phase damage model of magma-fracturing, and study the influence of viscosities and damage (void generation and microcracking) on the geometry properties of porosity waves. We first benchmark our solitary solutions with previous works and solve 2-D finite-amplitude waves numerically using spectral and semi-spectral method. We show that damage, decompaction weakening of the matrix and porosity-driven viscosities can alter the geometry of stable porosity waves, and result in an elongated or flattened wave front with a trail of smaller porosity. Such trails may localize subsequent waves and form porosity passage in the matrix. Scaling analysis of the time-dependent porosity waves are conducted and amount of magma reaching to the top of the melting region are estimated. Future work will include evaluating the thermal and seismic signatures during and after melt migration in two-phase porous flow.

  13. swot: Super W Of Theta (United States)

    Coupon, Jean; Leauthaud, Alexie; Kilbinger, Martin; Medezinski, Elinor


    SWOT (Super W Of Theta) computes two-point statistics for very large data sets, based on “divide and conquer” algorithms, mainly, but not limited to data storage in binary trees, approximation at large scale, parellelization (open MPI), and bootstrap and jackknife resampling methods “on the fly”. It currently supports projected and 3D galaxy auto and cross correlations, galaxy-galaxy lensing, and weighted histograms.


    CERN Multimedia


    What happened? A number of accidents have occurred with the use of 'Super Glues'. Some individuals have suffered injuries - severe irritation, or skin bonded together - through getting glue on their face and in their eyes. What are the hazards associated with glues? 'Super Glues' (i.e. cyanoacrylates): Are harmful if swallowed and are chemical irritants to the eyes, respiratory system and skin. Present the risk of polymerization (hardening) leading to skin damage. Be careful ! 'Super Glues' can bond to skin and eyes in seconds. Note: Other glues, resins and hardeners are also chemicals and as such can cause serious damage to the skin, eyes, respiratory or digestive tract. (For example: some components can be toxic, harmful, corrosive, sensitizing agents, etc.). How to prevent accidents in the future? Read the Material Safety Data Sheet (MSDS) for all of the glues you work with. Check the label on the container to find out which of the materials you work with are hazardous. Wear the right Per...

  15. Resolution and super-resolution. (United States)

    Sheppard, Colin J R


    Many papers have claimed the attainment of super-resolution, i.e. resolution beyond that achieved classically, by measurement of the profile of a feature in the image. We argue that measurement of the contrast of the image of a dark bar on a bright background does not give a measure of resolution, but of detection sensitivity. The width of a bar that gives an intensity at the center of the bar of 0.735 that in the bright region (the same ratio as in the Rayleigh resolution criterion) is λ/(13.9×numerical aperture) for the coherent case with central illumination. This figure, which compares with λ/(numerical aperture) for the Abbe resolution limit with central illumination, holds for the classical case, and so is no indication of super-resolution. Theoretical images for two points, two lines, arrays of lines, arrays of bars, and grating objects are compared. These results can be used a reference for experimental results, to determine if super-resolution has indeed been attained. The history of the development of the theory of microscope resolution is outlined. © 2017 Wiley Periodicals, Inc.


    Energy Technology Data Exchange (ETDEWEB)

    Socrates, Aristotle; Katz, Boaz; Dong Subo; Tremaine, Scott [Institute for Advanced Study, Princeton, NJ 08540 (United States)


    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e = 0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e > 0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is a-dot {proportional_to}a{sup 1/2} and consequently the number distribution satisfies dN/d log a{proportional_to}a{sup 1/2}. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  17. Spectral functions and transport coefficients from the functional renormalization group

    Energy Technology Data Exchange (ETDEWEB)

    Tripolt, Ralf-Arno


    In this thesis we present a new method to obtain real-time quantities like spectral functions and transport coefficients at finite temperature and density using the Functional Renormalization Group approach. Our non-perturbative method is thermodynamically consistent, symmetry preserving and based on an analytic continuation from imaginary to real time on the level of the flow equations. We demonstrate the applicability of this method by calculating mesonic spectral functions as well as the shear viscosity for the quark-meson model. In particular, results are presented for the pion and sigma spectral function at finite temperature and chemical potential, with a focus on the regime near the critical endpoint in the phase diagram of the quark-meson model. Moreover, the different time-like and space-like processes, which give rise to a complex structure of the spectral functions, are discussed. Finally, based on the momentum dependence of the spectral functions, we calculate the shear viscosity and the shear viscosity to entropy density ratio using the corresponding Green-Kubo formula.

  18. Assessing bitumen and heavy oil viscosity in situ

    Energy Technology Data Exchange (ETDEWEB)

    Larter, S.; Adams, J.; Jiang, D.; Snowdon, L.; Bennett, B.; Gates, I. [Calgary Univ., AB (Canada); Gushor Inc., Calgary, AB (Canada)


    Log-based techniques for evaluating the in-situ viscosity of oil rely on dead oil viscosity measurements are conducted in laboratories. However, bitumen viscosity is impacted by water; sediment and gas loads; emulsion formation; and shear properties. This abstract discussed a method of assessing the in-situ viscosity of bitumen and heavy oils. The method was designed to simulate the viscosity of heavy oil fluid flow in process conditions. Measured appropriate dead oil viscosity was combined with estimates of solution gas content using mixing rules in order to establish in-situ live oil viscosity estimates. The method takes into account solid and water loads, procedures for correction of viscosity for core storage artifacts, and the impact of variable bitumen saturation pressures through oil columns on live oil reconstruction algorithms.

  19. Mechanism of viscosity effect on magnetic island rotation

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailovskii, A.B.; Konovalov, S.V. [Institute of Nuclear Fusion, Russian Research Centre ' Kurchatov Institute' , Kurchatov Sq., 1, Moscow (Russian Federation); Pustovitov, V.D. [National Inst. for Fusion Science, Toki, Gifu (Japan); Tsypin, V.S. [Institute of Physics, University of Sao Paulo, Rua do Matao, Travessa R, SP (Brazil)


    It is shown that plasma viscosity does not influence the magnetic island rotation directly. Nevertheless, it leads to nonstationarity of the plasma velocity. This nonstationarity is the reason of the viscosity effect on island rotation. (author)

  20. Plasma Viscosity with Mass Transport in Spherical ICF Implosion Simulations

    CERN Document Server

    Vold, Erik L; Ortega, Mario I; Moll, Ryan; Fenn, Daniel; Molvig, Kim


    The effects of viscosity and small-scale atomic-level mixing on plasmas in inertial confinement fusion (ICF) currently represent challenges in ICF research. Many current ICF hydrodynamic codes ignore the effects of viscosity though recent research indicates viscosity and mixing by classical transport processes may have a substantial impact on implosion dynamics. We have implemented a Lagrange hydrodynamic code in one-dimensional spherical geometry with plasma viscosity and mass transport and including a three temperature model for ions, electrons, and radiation treated in a gray radiation diffusion approximation. The code is used to study ICF implosion differences with and without plasma viscosity and to determine the impacts of viscosity on temperature histories and neutron yield. It was found that plasma viscosity has substantial impacts on ICF shock dynamics characterized by shock burn timing, maximum burn temperatures, convergence ratio, and time history of neutron production rates. Plasma viscosity reduc...

  1. Anomalous diffraction in super-wavelength plasmonic metasurfaces

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong, E-mail:; Zhu, Jian-ze; Huang, Cheng-ping


    We demonstrate that super-wavelength sandwich plasmonic metasurfaces, with the top metal layer consisting of a periodic arrangement of differently sized rectangle patches, can support anomalous diffraction – one first-order diffraction is boosted greatly in a broad bandwidth while another first-order and zero-order diffractions are suppressed. More importantly, by adding and subtracting the patches in a unit cell and adjusting the geometric parameters, high efficiency and broadband first-order diffraction can be easily tuned from visible to near-, mid- and even far-infrared spectral regions. The metasurfaces can be applied as high-performance light dispersive components in beam splitters, thin-film solar cells and spectrometers. - Highlights: • The super-wavelength sandwich metasurfaces support anomalous diffraction. • The anomalous diffraction can be understood in terms of the self-adaptive LC-like resonances in the metal sandwiches. • The anomalous diffraction is dependent on the structure parameters. • Anomalous diffraction can be easily tuned from visible to infrared spectral regions. • The metasurfaces can be applied as high-performance light dispersive components.

  2. Pendulum Underwater - An Approach for Quantifying Viscosity (United States)

    Leme, José Costa; Oliveira, Agostinho


    The purpose of the experiment presented in this paper is to quantify the viscosity of a liquid. Viscous effects are important in the flow of fluids in pipes, in the bloodstream, in the lubrication of engine parts, and in many other situations. In the present paper, the authors explore the oscillations of a physical pendulum in the form of a long and lightweight wire that carries a ball at its lower end, which is totally immersed in water, so as to determine the water viscosity. The system used represents a viscous damped pendulum and we tried different theoretical models to describe it. The experimental part of the present paper is based on a very simple and low-cost image capturing apparatus that can easily be replicated in a physics classroom. Data on the pendulum's amplitude as a function of time were acquired using digital video analysis with the open source software Tracker.

  3. Bulk and shear viscosity in Hagedorn fluid

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, A.; Wahba, M. [Egyptian Center for Theoretical Physics (ECTP), MTI University, Faculty of Engineering, Cairo (Egypt)


    Assuming that the Hagedorn fluid composed of known particles and resonances with masses m <2 GeV obeys the first-order theory (Eckart) of relativistic fluid, we discuss the transport properties of QCD confined phase. Based on the relativistic kinetic theory formulated under the relaxation time approximation, expressions for bulk and shear viscosity in thermal medium of hadron resonances are derived. The relaxation time in the Hagedorn dynamical fluid exclusively takes into account the decay and eventually van der Waals processes. We comment on the in-medium thermal effects on bulk and shear viscosity and averaged relaxation time with and without the excluded-volume approach. As an application of these results, we suggest the dynamics of heavy-ion collisions, non-equilibrium thermodynamics and the cosmological models, which require thermo- and hydro-dynamics equations of state. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Caldera resurgence driven by magma viscosity contrasts. (United States)

    Galetto, Federico; Acocella, Valerio; Caricchi, Luca


    Calderas are impressive volcanic depressions commonly produced by major eruptions. Equally impressive is the uplift of the caldera floor that may follow, dubbed caldera resurgence, resulting from magma accumulation and accompanied by minor eruptions. Why magma accumulates, driving resurgence instead of feeding large eruptions, is one of the least understood processes in volcanology. Here we use thermal and experimental models to define the conditions promoting resurgence. Thermal modelling suggests that a magma reservoir develops a growing transition zone with relatively low viscosity contrast with respect to any newly injected magma. Experiments show that this viscosity contrast provides a rheological barrier, impeding the propagation through dikes of the new injected magma, which stagnates and promotes resurgence. In explaining resurgence and its related features, we provide the theoretical background to account for the transition from magma eruption to accumulation, which is essential not only to develop resurgence, but also large magma reservoirs.

  5. Viscosity solution of linear regulator quadratic for degenerate diffusions

    Directory of Open Access Journals (Sweden)


    Full Text Available The paper studied a linear regulator quadratic control problem for degenerate Hamilton-Jacobi-Bellman (HJB equation. We showed the existence of viscosity properties and established a unique viscosity solution of the degenerate HJB equation associated with this problem by the technique of viscosity solutions.

  6. On the scaling of entropy viscosity in high order methods


    Kornelus, Adeline; Appelö, Daniel


    In this work, we outline the entropy viscosity method and discuss how the choice of scaling influences the size of viscosity for a simple shock problem. We present examples to illustrate the performance of the entropy viscosity method under two distinct scalings.

  7. Effect of urea formaldehyde viscosity on urea formaldehyde and ...

    African Journals Online (AJOL)

    The melting point, refractive index, density and formaldehyde emission were found to increase with increase in UF viscosity while the dry time, moisture uptake and elongation at break were found to decrease with increase in viscosity. UF viscosity below 10.82 mPa.s was found to produce UF/UP copolymer composite which ...

  8. Predicting human blood viscosity in silico (United States)

    Fedosov, Dmitry A.; Pan, Wenxiao; Caswell, Bruce; Gompper, Gerhard; Karniadakis, George E.


    The viscosity of blood has long been used as an indicator in the understanding and treatment of disease, and the advent of modern viscometers allows its measurement with ever-improving clinical convenience. However, these advances have not been matched by theoretical developments that can yield a quantitative understanding of blood’s microrheology and its possible connection to relevant biomolecules (e.g., fibrinogen). Using coarse-grained molecular dynamics and two different red blood cell models, we accurately predict the dependence of blood viscosity on shear rate and hematocrit. We explicitly represent cell–cell interactions and identify the types and sizes of reversible rouleaux structures that yield a tremendous increase of blood viscosity at low shear rates. We also present the first quantitative estimates of the magnitude of adhesive forces between red cells. In addition, our simulations support the hypothesis, previously deduced from experiments, of yield stress as an indicator of cell aggregation. This non-Newtonian behavior is analyzed and related to the suspension’s microstructure, deformation, and dynamics of single red blood cells. The most complex cell dynamics occurs in the intermediate shear rate regime, where individual cells experience severe deformation and transient folded conformations. The generality of these cell models together with single-cell measurements points to the future prediction of blood-viscosity anomalies and the corresponding microstructures associated with various diseases (e.g., malaria, AIDS, and diabetes mellitus). The models can easily be adapted to tune the properties of a much wider class of complex fluids including capsule and vesicle suspensions. PMID:21730178

  9. RELAP-7 Numerical Stabilization: Entropy Viscosity Method

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Berry; M. O. Delchini; J. Ragusa


    The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The code is based on the INL's modern scientific software development framework, MOOSE (Multi-Physics Object Oriented Simulation Environment). The overall design goal of RELAP-7 is to take advantage of the previous thirty years of advancements in computer architecture, software design, numerical integration methods, and physical models. The end result will be a reactor systems analysis capability that retains and improves upon RELAP5's capability and extends the analysis capability for all reactor system simulation scenarios. RELAP-7 utilizes a single phase and a novel seven-equation two-phase flow models as described in the RELAP-7 Theory Manual (INL/EXT-14-31366). The basic equation systems are hyperbolic, which generally require some type of stabilization (or artificial viscosity) to capture nonlinear discontinuities and to suppress advection-caused oscillations. This report documents one of the available options for this stabilization in RELAP-7 -- a new and novel approach known as the entropy viscosity method. Because the code is an ongoing development effort in which the physical sub models, numerics, and coding are evolving, so too must the specific details of the entropy viscosity stabilization method. Here the fundamentals of the method in their current state are presented.

  10. Wound dressing based on nonwoven viscose fabrics. (United States)

    Abou-Okeil, A; Sheta, A M; Amr, A; Ali, Marwa A


    Nonwoven viscose fabric was treated with chitosan/polyvinyl alcohol (PVA) using pad-dry method, using different concentrations of chitosan and PVA. Increasing the amount of PVA leads to increasing of air permeability. Water permeability increased by increasing the amount of PVA to 2 ml (10% solution) then decreased by any increase of the quantity of PVA solution. Roughness increased with increasing the amount of 10% PVA solution. It is shown that roughness, water and air permeability increased with increasing the chitosan concentration. Antibacterial properties was increased with increasing PVA/or chitosan concentration. The chitosan/PVA treated nonwoven viscose fabric was immersed in a solution of Ag nanoparticles. The chitosan/PVA/Ag nanoparticles treated nonwoven fabrics were used as wound dressings on French white Bouscat rabbits, with age ranged from 1 to 2 years. A complete healing was achieved using wound dressing consists of nonwoven viscose fabric treated with chitosan/PVA/Ag nanoparticles after 21 days. The histopathological examination confirmed the complete re-epithelialization and averagely thick epidermis formation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Spectral Imaging by Upconversion

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter


    We present a method to obtain spectrally resolved images using upconversion. By this method an image is spectrally shifted from one spectral region to another wavelength. Since the process is spectrally sensitive it allows for a tailored spectral response. We believe this will allow standard...... silicon based cameras designed for visible/near infrared radiation to be used for spectral images in the mid infrared. This can lead to much lower costs for such imaging devices, and a better performance....

  12. Spectral Decomposition Algorithm (SDA) (United States)

    National Aeronautics and Space Administration — Spectral Decomposition Algorithm (SDA) is an unsupervised feature extraction technique similar to PCA that was developed to better distinguish spectral features in...

  13. Influence of blood lipids on plasma and blood viscosity. (United States)

    Irace, Concetta; Carallo, Claudio; Scavelli, Faustina; Esposito, Teresa; De Franceschi, Maria Serena; Tripolino, Cesare; Gnasso, Agostino


    The relationship between hyperlipidemia and blood and plasma viscosity is not completely clear. While increasing viscosity is often reported with increasing blood lipids, lipid-lowering treatments are often unable to normalize the viscosity values. Aim of this study is to try to clarify the relationship between blood lipids and viscosity. Apparently healthy subjects were enrolled (n = 410). Smokers, diabetics, obese, and hypertriglyceridemic (above 400 mg/dl) were excluded. Blood (at shear rate 225/s) and plasma viscosity were measured at 37°C. Erythrocyte rigidity (Tk) was calculated according to Dintenfass. Blood lipids and glucose were measured by routine methods. Hyperlipidemic subjects (n = 315) had higher values of plasma viscosity (1.44 ± 0.13 vs. 1.40 ± 0.12 cP, p = 0.007), and blood viscosity (4.51 ± 0.54 vs. 4.35 ± 0.55 cP, p = 0.013), compared to normolipidemic subjects (n = 95). In simple correlation analysis, plasma viscosity was directly associated with LDL cholesterol, and inversely with Tk and HDL cholesterol. In multiple regression analysis the association with LDL and HDL was strengthened, though these two variables as a whole accounted for only 5% (adjusted R2) of the variability of plasma viscosity. Blood viscosity was significantly associated with haematocrit, plasma viscosity, Tk and all considered variables but age in simple correlation analysis, but only with haematocrit, plasma viscosity and Tk in multiple regression analysis. LDL cholesterol and HDL cholesterol influence plasma viscosity, but not blood viscosity. Triglycerides up to values of 400 mg/dl do not seem to have important effects, at least in apparently healthy subjects and at the shear rates used in the present study. The contribution of LDL and HDL cholesterol to plasma viscosity seems however quite limited.

  14. Reference Correlation for the Viscosity of Ethane

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Eckhard, E-mail: [Institut für Chemie, Universität Rostock, D-18059 Rostock (Germany); Span, Roland [Lehrstuhl für Thermodynamik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Herrmann, Sebastian [Fachgebiet Technische Thermodynamik, Hochschule Zittau/Görlitz, D-02763 Zittau (Germany)


    A new representation of the viscosity for the fluid phase of ethane includes a zero-density correlation and a contribution for the critical enhancement, initially both developed separately, but based on experimental data. The higher-density contributions are correlated as a function of the reduced density δ = ρ/ρ{sub c} and of the reciprocal reduced temperature τ = T{sub c}/T (ρ{sub c}—critical density and T{sub c}—critical temperature). The final formulation contains 14 coefficients obtained using a state-of-the-art linear optimization algorithm. The evaluation and choice of the selected primary data sets is reviewed, in particular with respect to the assessment used in earlier viscosity correlations. The new viscosity surface correlation makes use of the reference equation of state for the thermodynamic properties of ethane by Bücker and Wagner [J. Phys. Chem. Ref. Data 35, 205 (2006)] and is valid in the fluid region from the melting line to temperatures of 675 K and pressures of 100 MPa. The viscosity in the limit of zero density is described with an expanded uncertainty of 0.5% (coverage factor k = 2) for temperatures 290 < T/K < 625, increasing to 1.0% at temperatures down to 212 K. The uncertainty of the correlated values is 1.5% in the range 290 < T/K < 430 at pressures up to 30 MPa on the basis of recent measurements judged to be very reliable as well as 4.0% and 6.0% in further regions. The uncertainty in the near-critical region (1.001 < 1/τ < 1.010 and 0.8 < δ < 1.2) increases with decreasing temperature up to 3.0% considering the available reliable data. Tables of the viscosity calculated from the correlation are listed in an appendix for the single-phase region, for the vapor–liquid phase boundary, and for the near-critical region.

  15. Measurement of viscosity of liquids using optical tweezers (United States)

    Statsenko, Anna; Inami, Wataru; Kawata, Yoshimasa


    We propose a method for measuring viscosities of unknown liquids by using optical tweezers combined with optical microscopy. We trapped 1- μm particles in water-glycerin mixtures and analyzed the dependence of the motion on viscosity. Based on our calibration with various water-glycerin mixtures, we propose a method for determination of viscosities of unknown liquids with high accuracy. We discuss how the method can be applied to measure the viscosity of liquids that are available only in small quantities. This non-invasive method of studying viscosities could be especially applicable in investigations of biological samples.

  16. Viscosity as related to dietary fiber: a review. (United States)

    Dikeman, Cheryl L; Fahey, George C


    Viscosity is a physicochemical property associated with dietary fibers, particularly soluble dietary fibers. Viscous dietary fibers thicken when mixed with fluids and include polysaccharides such as gums, pectins, psyllium, and beta-glucans. Although insoluble fiber particles may affect viscosity measurement, viscosity is not an issue regards insoluble dietary fibers. Viscous fibers have been credited for beneficial physiological responses in human, animal, and animal-alternative in vitro models. The following article provides a review of viscosity as related to dietary fiber including definitions and instrumentation, factors affecting viscosity of solutions, and effects of viscous polysaccharides on glycemic response, blood lipid attenuation, intestinal enzymatic activity, digestibility, and laxation.

  17. Results from Super-Kamiokande

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Takaaki


    Results from Super-Kamiokande on atmospheric neutrinos and solar neutrinos are presented. The atmospheric neutrino data exhibited a zenith angle dependent deficit of muon neutrinos. Experimental biases and uncertainties in the prediction were unable to explain the data. However, the data were in good agreement with two flavor {nu}{sub {mu}} {r_reversible} {nu}{sub {tau}} oscillations. The solar neutrino data showed a deficit of the neutrinos. The day-night effect and the energy spectrum of recoil electrons were studied.

  18. Imaging tumor microscopic viscosity in vivo using molecular rotors (United States)

    Shimolina, Lyubov’ E.; Izquierdo, Maria Angeles; López-Duarte, Ismael; Bull, James A.; Shirmanova, Marina V.; Klapshina, Larisa G.; Zagaynova, Elena V.; Kuimova, Marina K.


    The microscopic viscosity plays an essential role in cellular biophysics by controlling the rates of diffusion and bimolecular reactions within the cell interior. While several approaches have emerged that have allowed the measurement of viscosity and diffusion on a single cell level in vitro, the in vivo viscosity monitoring has not yet been realized. Here we report the use of fluorescent molecular rotors in combination with Fluorescence Lifetime Imaging Microscopy (FLIM) to image microscopic viscosity in vivo, both on a single cell level and in connecting tissues of subcutaneous tumors in mice. We find that viscosities recorded from single tumor cells in vivo correlate well with the in vitro values from the same cancer cell line. Importantly, our new method allows both imaging and dynamic monitoring of viscosity changes in real time in live animals and thus it is particularly suitable for diagnostics and monitoring of the progress of treatments that might be accompanied by changes in microscopic viscosity. PMID:28134273

  19. Experimental study on viscosity reduction for residual oil by ultrasonic. (United States)

    Huang, Xintong; Zhou, Cuihong; Suo, Quanyu; Zhang, Lanting; Wang, Shihan


    Because of characteristics of large density, high viscosity and poor mobility, the processing and transportation of residual oil are difficult and challenging, viscosity reduction of residual oil is of great significance. In this paper, the effects of different placement forms of ultrasonic transducers on the sound pressure distribution of ultrasonic inside a cubic container have been simulated, the characteristics of oil bath heating and ultrasonic viscosity reduction were compared, viscosity reduction rule of residual oil was experimentally analyzed by utilizing Response Surface Method under conditions of changing ultrasonic exposure time, power and action mode, the mechanism of viscosity reduction was studied by applying Fourier transform infrared spectrometer, the viscosity retentivity experiment was carried out at last. Experiments were conducted using two kinds of residual oil, and results show that ultrasonic effect on the viscosity reduction of residual oil is significant, the higher viscosity of residual oil, the better effect of ultrasonic, ultrasonic power and exposure time are the significant factors affecting the viscosity reduction rate of residual oil. The maximum viscosity reduction rate is obtained under condition of ultrasonic power is 900W, exposure time is 14min and action mode of exposure time is 2s and interrupting time is 2s, viscosity reduction rate reaching up to 63.95%. The infrared spectroscopy results show that light component in residual oil increased. The viscosity retentivity experiment results show that the viscosity reduction effect remains very well. This paper can provide data reference for the application of ultrasonic in the field of viscosity reduction for residual oil. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Long-time stability effects of quadrature and artificial viscosity on nodal discontinuous Galerkin methods for gas dynamics (United States)

    Durant, Bradford; Hackl, Jason; Balachandar, Sivaramakrishnan


    Nodal discontinuous Galerkin schemes present an attractive approach to robust high-order solution of the equations of fluid mechanics, but remain accompanied by subtle challenges in their consistent stabilization. The effect of quadrature choices (full mass matrix vs spectral elements), over-integration to manage aliasing errors, and explicit artificial viscosity on the numerical solution of a steady homentropic vortex are assessed over a wide range of resolutions and polynomial orders using quadrilateral elements. In both stagnant and advected vortices in periodic and non-periodic domains the need arises for explicit stabilization beyond the numerical surface fluxes of discontinuous Galerkin spectral elements. Artificial viscosity via the entropy viscosity method is assessed as a stabilizing mechanism. It is shown that the regularity of the artificial viscosity field is essential to its use for long-time stabilization of small-scale features in nodal discontinuous Galerkin solutions of the Euler equations of gas dynamics. Supported by the Department of Energy Predictive Science Academic Alliance Program Contract DE-NA0002378.

  1. Classification of Low Dimensional Lie Super-Bialgebras


    Juszczak, Cezary; Sobczyk, Jan T.


    A thorough analysis of Lie super-bialgebra structures on Lie super-algebras osp(1|2) and super-e(2) is presented. Combined technique of computer algebraic computations and a subsequent identification of equivalent structures is applied. In all the cases Poisson-Lie brackets on supergroups are found. Possibility of quantizing them in order to obtain quantum groups is discussed. It turns out to be straightforward for all but one structures for super-E(2) group.

  2. From Suitable Weak Solutions to Entropy Viscosity

    KAUST Repository

    Guermond, Jean-Luc


    This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i) to recall basic mathematical properties of the three-dimensional incompressible Navier-Stokes equations and to show how they might relate to LES (ii) to introduce an entropy viscosity technique based on the notion of suitable weak solution and to illustrate numerically this concept. © 2010 Springer Science+Business Media, LLC.

  3. Viscosity: From air to hot nuclei

    Indian Academy of Sciences (India)

    physician and physiologist, who studied non-turbulent flow of liquids through pipes, such as blood flow in capillaries and veins: 1 P = 0.1 Pa s = 1 g/(cm s), 1 cP = 1 mPa s. = 0.001 Pa s. The values of viscosity are different for various substances: 0.02 cP for air at 18. ◦. C, 1 cP for water at 20. ◦. C, 2000–10000 cP for honey, ...

  4. On the Spectral Singularities and Spectrality of the Hill Operator


    Veliev, O. A.


    First we study the spectral singularity at infinity and investigate the connections of the spectral singularities and the spectrality of the Hill operator. Then we consider the spectral expansion when there is not the spectral singularity at infinity.

  5. Ending Aging in Super Glassy Polymer Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Lau, CH; Nguyen, PT; Hill, MR; Thornton, AW; Konstas, K; Doherty, CM; Mulder, RJ; Bourgeois, L; Liu, ACY; Sprouster, DJ; Sullivan, JP; Bastow, TJ; Hill, AJ; Gin, DL; Noble, RD


    Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N-2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations.

  6. Shear viscosity and out of equilibrium dynamics

    CERN Document Server

    El, Andrej; Xu, Zhe; Greiner, Carsten


    Using the Grad's method we calculate the entropy production and derive a formula for the second order shear viscosity coefficient in a one-dimensionally expanding particle system, which can also be considered out of chemical equilibrium. For a one-dimensional expansion of gluon matter with Bjorken boost invariance the shear tensor and the shear viscosity to entropy density ratio $\\eta/s$ are numerically calculated by an iterative and self-consistent prescription within the second order Israel-Stewart hydrodynamics and by a microscopic parton cascade transport theory. Compared with $\\eta/s$ obtained using the Navier-Stokes approximation, the present result is about 20% larger at a QCD coupling $\\alpha_s \\sim 0.3$(with $\\eta/s\\approx 0.18$) and is a factor of 2-3 larger at a small coupling $\\alpha_s \\sim 0.01$. We demonstrate an agreement between the viscous hydrodynamic calculations and the microscopic transport results on $\\eta/s$, except when employing a small $\\alpha_s$. On the other hand, we demonstrate th...

  7. Shear viscosity and out of equilibrium dynamics

    CERN Document Server

    El, Andrej; Xu, Zhe; Greiner, Carsten


    Using Grad’s method, we calculate the entropy production and derive a formula for the second-order shear viscosity coefficient in a one-dimensionally expanding particle system, which can also be considered out of chemical equilibrium. For a one-dimensional expansion of gluon matter with Bjorken boost invariance, the shear tensor and the shear viscosity to entropy density ratio η/s are numerically calculated by an iterative and self-consistent prescription within the second-order Israel-Stewart hydrodynamics and by a microscopic parton cascade transport theory. Compared with η/s obtained using the Navier-Stokes approximation, the present result is about 20% larger at a QCD coupling αs ∼ 0.3 (with η/s ≈ 0.18) and is a factor of 2–3 larger at a small coupling αs ∼ 0.01. We demonstrate an agreement between the viscous hydrodynamic calculations and the microscopic transport results on η/s, except when employing a small αs . On the other hand, we demonstrate that for such small αs , the gluon syst...

  8. Solvent viscosity dependence for enzymatic reactions

    CERN Document Server

    Sitnitsky, A E


    A mechanism for relationship of solvent viscosity with reaction rate constant at enzyme action is suggested. It is based on fluctuations of electric field in enzyme active site produced by thermally equilibrium rocking (cranckshaft motion) of the rigid plane (in which the dipole moment $\\approx 3.6 D$ lies) of a favourably located and oriented peptide group (or may be a few of them). Thus the rocking of the plane leads to fluctuations of the electric field of the dipole moment. These fluctuations can interact with the reaction coordinate because the latter in its turn has transition dipole moment due to separation of charges at movement of the reacting system along it. The rocking of the plane of the peptide group is sensitive to the microviscosity of its environment in protein interior and the latter is a function of the solvent viscosity. Thus we obtain an additional factor of interrelationship for these characteristics with the reaction rate constant. We argue that due to the properties of the cranckshaft ...

  9. Predicting human blood viscosity in silico

    Energy Technology Data Exchange (ETDEWEB)

    Fedosov, Dmitry A. [Inst. of Complex Systems and Inst. for Advanced Simulation, Julich (Germany); Brown Univ., Providence, RI (United States); Pan, Wenxiao [Brown Univ., Providence, RI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Caswell, Bruce [Brown Univ., Providence, RI (United States); Gompper, Gerhard [Inst. of Complex Systems and Inst. for Advanced Simulation, Julich (Germany); Karniadakis, George E. [Brown Univ., Providence, RI (United States)


    Cellular suspensions such as blood are a part of living organisms and their rheological and flow characteristics determine and affect majority of vital functions. The rheological and flow properties of cell suspensions are determined by collective dynamics of cells, their structure or arrangement, cell properties and interactions. We study these relations for blood in silico using a mesoscopic particle-based method and two different models (multi-scale/low-dimensional) of red blood cells. The models yield accurate quantitative predictions of the dependence of blood viscosity on shear rate and hematocrit. We explicitly model cell aggregation interactions and demonstrate the formation of reversible rouleaux structures resulting in a tremendous increase of blood viscosity at low shear rates and yield stress, in agreement with experiments. The non-Newtonian behavior of such cell suspensions (e.g., shear thinning, yield stress) is analyzed and related to the suspension’s microstructure, deformation and dynamics of single cells. We provide the flrst quantitative estimates of normal stress differences and magnitude of aggregation forces in blood. Finally, the flexibility of the cell models allows them to be employed for quantitative analysis of a much wider class of complex fluids including cell, capsule, and vesicle suspensions.

  10. Textural perception of liquid emulsions: Role of oil content, oil viscosity and emulsion viscosity

    NARCIS (Netherlands)

    Aken, van G.A.; Vingerhoeds, M.H.; Wijk, de R.A.


    This work describes a study on the in-mouth textural perception of thickened liquid oil-in-water emulsions. The variables studied are oil content, oil viscosity, and the concentration of polysaccharide thickener. Gum arabic was chosen as the thickener because of the nearly Newtonian behavior of its

  11. Modeling the viscosity of silicate melts containing manganese oxide

    Directory of Open Access Journals (Sweden)

    Kim Wan-Yi


    Full Text Available Our recently developed model for the viscosity of silicate melts is applied to describe and predict the viscosities of oxide melts containing manganese oxide. The model requires three pairs of adjustable parameters that describe the viscosities in three systems: pure MnO, MnO-SiO2 and MnO-Al2O3-SiO2. The viscosity of other ternary and multicomponent silicate melts containing MnO is then predicted by the model without any additional adjustable model parameters. Experimental viscosity data are reviewed for melts formed by MnO with SiO2, Al2O3, CaO, MgO, PbO, Na2O and K2O. The deviation of the available experimental data from the viscosities predicted by the model is shown to be within experimental error limits.

  12. Viscosity Control of Protein Solution by Small Solutes: A Review. (United States)

    Hong, Taehun; Iwashita, Kazuki; Shiraki, Kentaro


    Viscosity of protein solution is one of the most troublesome issues for the high-concentration formulation of protein drugs. In this review, we summarize the practical methods that suppress the viscosity of protein solution using small molecular additives. The small amount of salts decreases the viscosity that results from electrostatic repulsion and attraction. The chaotrope suppresses the hydrophobic attraction and cluster formation, which can lower the solution viscosity. Arginine hydrochloride (ArgHCl) also suppresses the solution viscosity due to the hydrophobic and aromatic interactions between protein molecules. The small molecular additives are the simplest resolution of the high viscosity of protein solution as well as understanding of the primary cause in complex phenomena of protein interactions. Copyright© Bentham Science Publishers; For any queries, please email at

  13. Study of shear viscosity of SU(2)-gluodynamics within lattice simulation

    Energy Technology Data Exchange (ETDEWEB)

    Astrakhantsev, N.Yu. [Institute for Theoretical and Experimental Physics,Moscow, 117218 (Russian Federation); Moscow Institute of Physics and Technology,Dolgoprudny, 141700 (Russian Federation); Braguta, V.V. [Institute for Theoretical and Experimental Physics,Moscow, 117218 (Russian Federation); Institute for High Energy Physics NRC “Kurchatov Institute”,Protvino, 142281 Russian Federation (Russian Federation); Far Eastern Federal University, School of Biomedicine,Vladivostok, 690950 (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute),Kashirskoe highway, 31, Moscow, 115409 (Russian Federation); Kotov, A.Yu. [Institute for Theoretical and Experimental Physics,Moscow, 117218 (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute),Kashirskoe highway, 31, Moscow, 115409 (Russian Federation)


    This paper is devoted to the study of two-point correlation function of the energy-momentum tensor 〈T{sub 12}T{sub 12}〉 for SU(2)-gluodynamics within lattice simulation of QCD. Using multilevel algorithm we carried out the measurement of the correlation function at the temperature T/T{sub c}≃1.2. It is shown that lattice data can be described by spectral functions which interpolate between hydrodynamics at low frequencies and asymptotic freedom at high frequencies. The results of the study of spectral functions allowed us to estimate the ratio of shear viscosity to the entropy density η/s=0.134±0.057.

  14. Super high-rise buildings

    Energy Technology Data Exchange (ETDEWEB)

    Maryon, J.C.


    This patent describes a super high-rise building for human occupation having at least 100 vertically spaced, human-occupiable stories comprising: a foundation; and a hollow vertical prism of reinforced concrete, mounted on the foundation and being at least 100 stories high, for transmitting to the foundation substantially all loads above at least the 75th floor of the building in a manner such that automatic lateral rigidity, stability, and strength are attained. The sides of the prism have apertures for such purposes as allowing human movement between the inside end and outside of the prism. The portion of substantially any horizontal circumference of the prism which is occupied by the apertures is less than about 25% of the horizontal circumference.

  15. Annotation: Hyperlexia: disability or superability? (United States)

    Grigorenko, Elena L; Klin, Ami; Volkmar, Fred


    Hyperlexia is the phenomenon of spontaneous and precocious mastery of single-word reading that has been of interest to clinicians and researchers since the beginning of the last century. An extensive search of publications on the subject of hyperlexia was undertaken and all available publications were reviewed. The literature can be subdivided into discussions of the following issues: (1) whether hyperlexia is a phenomenon that is characteristic only of specific clinical populations (e.g., children with developmental delays) or whether it can also be observed in the general population; (2) whether hyperlexia is a distinct syndrome comorbid with a number of different disorders or whether it is a part of the spectrum of some other clinical condition(s); (3) whether hyperlexia should be defined through single-word reading superiority with regard to reading comprehension, vocabulary, general intelligence, any combination of the three, or all three characteristics; (4) whether there is a specific neuropsychological profile associated with hyperlexia; (5) whether hyperlexia is characterized by a particular developmental profile; and (6) whether hyperlexia should be viewed as a disability (deficit) or superability (talent). We interpret the literature as supporting the view that hyperlexia is a superability demonstrated by a very specific group of individuals with developmental disorders (defined through unexpected single-word reading in the context of otherwise suppressed intellectual functioning) rather than as a disability exhibited by a portion of the general population (defined through a discrepancy between levels of single-word reading and comprehension). We simultaneously argue, however, that multifaceted and multi-methodological approaches to studying the phenomenon of hyperlexia, defined within the research framework of understanding single-word reading, are warranted and encouraged.

  16. Experimental investigation of the effect of liquid viscosity on slug flow in small diameter bubble column

    Directory of Open Access Journals (Sweden)

    Azzopardi Barry John


    Full Text Available The effect of liquid viscosity on slug flow in a 50 mm diameter bubble column was investigated experimentally using air-silicone oil as operating fluid with silicone oil of viscosities 5, 100, 1000 and 5000 mPa.s. Data was collected using Electrical Capacitance Tomography (ECT, a non-intrusive advanced instrumentation measuring technique and the high Speed Video Camera, through which the slug parameters such as length of Taylor bubbles and liquid slug, void fraction in Taylor bubbles and liquid slug, slug frequency, film thickness and pressure gradient in the slug, were measured and analyzed. The analysis was done using the void fraction time series, probability density function and power spectral density plots. Superficial gas velocities of 0.02≤Ugs≤0.361 m/s were used in the experiment. It was also observed that as viscosity increases, slug frequency, structure velocity, length of liquid slug, void fraction in liquid slug and void fraction in Taylor bubbles decreases; while the length of Taylor bubble, film thickness and pressure gradient in the slug increases.

  17. Non-invasive fluid density and viscosity measurement (United States)

    Sinha, Dipen N [Los Alamos, NM


    The noninvasively measurement of the density and viscosity of static or flowing fluids in a section of pipe such that the pipe performs as the sensing apparatus, is described. Measurement of a suitable structural vibration resonance frequency of the pipe and the width of this resonance permits the density and viscosity to be determined, respectively. The viscosity may also be measured by monitoring the decay in time of a vibration resonance in the pipe.

  18. Impact of Viscosity on Filling the Injection Mould Cavity

    Directory of Open Access Journals (Sweden)

    Satin Lukáš


    Full Text Available The aim of this paper is to look closer at the rheological properties of plastics and their impact on technology in the plastics processing industry. The paper focuses on the influence of viscosity of the material on filling the mould cavity. Four materials were tested with the settings of process parameters with different viscosity. Using simulation software of Moldex3D, we can see the effect of change in viscosity in the material to be filled.

  19. Super Unit Cells in Aperture-Based Metamaterials

    Directory of Open Access Journals (Sweden)

    Dragan Tanasković


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

  20. Effect of temperature on the viscosities of mixed micellar solutions (United States)

    Prasad, C. Durga; Kumar, D. Sudheer; Sarma, G. V. S.; Ramesh, K. V.


    The effect of addition of Triton X-100 (TX-100) on the viscosities of Sodium dodecyl sulphate (SDS) micellar solution containingNaCl and Cetyltrimethylammonium bromide (CTAB) micellar solution containingKBr at various temperatures are presented. The viscosity of SDS micellar solution is found to increase on addition of TX-100 at all temperatures (25 to 45 °C). However the increase in viscosity is large up to certain % of TX-100, after that the increase in viscosity is found to be small. Where as in CTAB micelles, at lower temperatures, the viscosity of micellar solution decreased up to certain composition of TX-100 and with further addition of TX-100 the viscosity got increaed. At higher temperatures viscosity of CTAB micellar solution increased on addition of TX-100. Depending on the nature of surfactant system and temperature, the viscosity of micellar solution may increase or decrease on addition of TX-100. The thermodynamic parameters for the viscous flow of micellar solutions in the presence of TX-100 are also determined. The effect of TX-100 on the viscosity and the activation enthalpy for viscous flow of anionic micelles is tremendously large as compared to cationic micelles. This is due to transition of micellar shape from rod to elongated rod or to sphere in the presence of added TX-100.

  1. Viscosity Prediction of Hydrocarbon Mixtures Based on the Friction Theory

    DEFF Research Database (Denmark)

    Zeberg-Mikkelsen, Claus Kjær; Cisneros, Sergio; Stenby, Erling Halfdan


    The application and capability of the friction theory (f-theory) for viscosity predictions of hydrocarbon fluids is further illustrated by predicting the viscosity of binary and ternary liquid mixtures composed of n-alkanes ranging from n-pentane to n-decane for wide ranges of temperature and from...... low to high pressures. In the f-theory viscosity predictions the SRK and the PRSV EOS have respectively been used. Further, a comparison with the widely used LBC viscosity model shows that better results are obtained with the f-theory models. The obtained AAD% is within or close to the experimental...

  2. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz


    above the linear viscoelastic prediction at intermediate strains, indicating strain hardening. The steady elongational viscosities are monotone decreasing functions of elongation rate. At elongation rates larger than the inverse reptation time, the steady elongational viscosity scales linearly......Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...... with molar mass at fixed elongation rate....

  3. Fluorescence-based Broad Dynamic Range Viscosity Probes. (United States)

    Dragan, Anatoliy; Graham, August E; Geddes, Chris D


    We introduce two new fluorescent viscosity probes, SYBR Green (SG) and PicoGreen (PG), that we have studied over a broad range of viscosity and in collagen solutions. In water, both dyes have low quantum yields and excited state lifetimes, while in viscous solvents or in complex with DNA both parameters dramatically (300-1000-fold) increase. We show that in log-log scale the dependence of the dyes' quantum yield vs. viscosity is linear, the slope of which is sensitive to temperature. Application of SG and PG, as a fluorescence-based broad dynamic range viscosity probes, to the life sciences is discussed.

  4. Viscosity of Heterogeneous Silicate Melts: A Non-Newtonian Model (United States)

    Liu, Zhuangzhuang; Blanpain, Bart; Guo, Muxing


    The recently published viscosity data of heterogeneous silicate melts with well-documented structure and experimental conditions are critically re-analyzed and tabulated. By using these data, a non-Newtonian viscosity model incorporating solid fraction, solid shape, and shear rate is proposed on the basis of the power-law equation. This model allows calculating the viscosity of the heterogeneous silicate melts with solid fraction up to 34 vol pct. The error between the calculated and measured data is evaluated to be 32 pct, which is acceptable considering the large error in viscosity measurement of the completely liquid silicate melt.

  5. Solar neutrino measurements in Super-Kamiokande-II

    CERN Document Server

    Cravens, J P; Iida, T; Ishihara, K; Kameda, J; Koshio, Y; Minamino, A; Mitsuda, C; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Ogawa, H; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takeuchi, Y; Ueshima, K; Watanabe, H; Yamada, S; Higuchi, I; Ishihara, C; Ishitsuka, M; Kajita, T; Kaneyuki, K; Mitsuka, G; Nishino, H; Okumura, K; Saji, C; Takenaga, Y; Clark, S; Desai, S; Dufour, F; Kearns, E; Likhoded, S; Litos, M; Raaf, Jennifer L; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Casper, D; Dunmore, J; Kropp, W R; Liu, D W; Mine, S; Regis, C; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Fechner, M; Scholberg, K; Tanimoto, N; Walter, C W; Wendell, R; Ellsworth, R W; Tasaka, S; Guillian, G; Learned, J G; Matsuno, S; Messier, M D; Watanabe, Y; Hayato, Y; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nitta, K; Oyama, Y; Totsuka, Y; Suzuki, A T; Hasegawa, M; Hiraide, K; Kato, I; Maesaka, H; Nakaya, T; Nishikawa, K; Sasaki, T; Sato, H; Yamamoto, S; Yokoyama, M; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Sullivan, G W; Turcan, D; Habig, A; Fukuda, Y; Sato, T; Itow, Y; Koike, T; Tanaka, T; Jung, C K; Kato, T; Kobayashi, K; Malek, M; McGrew, C; Sarrat, A; Terri, R; Yanagisawa, C; Tamura, N; Idehara, Y; Ikeda, M; Sakuda, M; Sugihara, M; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Yoo, J; Ishizuka, T; Okazawa, H; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Furuse, Y; Ishii, H; Nishijima, K; Ishino, H; Koshiba, M; Chen, S; Deng, Z; Liu, Y; Kielczewska, D; Berns, H; Gran, R; Shiraishi, K K; Stachyra, A; Thrane, E; Washburn, K; Wilkes, R J


    The results of the second phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first phase. The solar neutrino flux spectrum and time-variation as well as oscillation results are statistically consistent with the first phase and do not show spectral distortion. The time-dependent flux measurement of the combined first and second phases coincides with the full period of solar cycle 23 and shows no correlation with solar activity. The measured boron 8 total flux is 2.38 +/-0.05(stat.) +0.16-0.15(sys.) X 10^6 cm^-2 sec^-1 and the day-night difference is found to be -6.3 +/-4.2(stat.) +/-3.7(sys.) %. There is no evidence of systematic tendencies between the first and second phases.

  6. Impact of initial pulse shape on the nonlinear spectral compression in optical fibre (United States)

    Boscolo, Sonia; Chaussard, Frederic; Andresen, Esben; Rigneault, Hervé; Finot, Christophe


    We theoretically study the effects of the temporal intensity profile of the initial pulse on the nonlinear propagation spectral compression process arising from nonlinear propagation in an optical fibre. Various linearly chirped input pulse profiles are considered, and their dynamics is explained with the aid of time-frequency representations. While initially parabolic-shaped pulses show enhanced spectral compression compared to Gaussian pulses, no significant spectral narrowing occurs when initially super-Gaussian pulses are used. Triangular pulses lead to a spectral interference phenomenon similar to the Fresnel bi-prism experiment.

  7. Spectral broadening of picosecond pulses forming dispersive shock waves in optical fibers. (United States)

    Parriaux, A; Conforti, M; Bendahmane, A; Fatome, J; Finot, C; Trillo, S; Picqué, N; Millot, G


    We investigate analytically, numerically, and experimentally the spectral broadening of pulses that undergo the formation of dispersive shocks, addressing in particular pulses in the range of tens of ps generated via electro-optic modulation of a continuous-wave laser. We give an analytical estimate of the maximal spectral extension and show that super-Gaussian waveforms favor the generation of flat-topped spectra. We also show that the weak residual background of the modulator produces undesired spectral ripples. Spectral measurements confirm our estimates and agree well with numerical integration of the nonlinear Schrödinger equation.

  8. Holographic bulk viscosity: GPR vs EO

    CERN Document Server

    Buchel, Alex; Kiritsis, Elias


    Recently Eling and Oz (EO) proposed a formula for the holographic bulk viscosity, in arXiv:1103.1657, derived from the null horizon focusing equation. This formula seems different from that obtained earlier by Gubser, Pufu and Rocha (GPR) in arXiv:0806.0407 calculated from the IR limit of the two-point function of the trace of the stress tensor. The two were shown to agree only for some simple scaling cases. We point out that the two formulae agree in two non-trivial holographic theories describing RG flows. The first is the strongly coupled N=2* gauge theory plasma. The second is the semi-phenomenological model of Improved Holographic QCD.

  9. SuperB Progress Report for Physics

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, B.; /Aachen, Tech. Hochsch.; Matias, J.; Ramon, M.; /Barcelona, IFAE; Pous, E.; /Barcelona U.; De Fazio, F.; Palano, A.; /INFN, Bari; Eigen, G.; /Bergen U.; Asgeirsson, D.; /British Columbia U.; Cheng, C.H.; Chivukula, A.; Echenard, B.; Hitlin, D.G.; Porter, F.; Rakitin, A.; /Caltech; Heinemeyer, S.; /Cantabria Inst. of Phys.; McElrath, B.; /CERN; Andreassen, R.; Meadows, B.; Sokoloff, M.; /Cincinnati U.; Blanke, M.; /Cornell U., Phys. Dept.; Lesiak, T.; /Cracow, INP /DESY /Zurich, ETH /INFN, Ferrara /Frascati /INFN, Genoa /Glasgow U. /Indiana U. /Mainz U., Inst. Phys. /Karlsruhe, Inst. Technol. /KEK, Tsukuba /LBL, Berkeley /UC, Berkeley /Lisbon, IST /Ljubljana U. /Madrid, Autonoma U. /Maryland U. /MIT /INFN, Milan /McGill U. /Munich, Tech. U. /Notre Dame U. /PNL, Richland /INFN, Padua /Paris U., VI-VII /Orsay, LAL /Orsay, LPT /INFN, Pavia /INFN, Perugia /INFN, Pisa /Queen Mary, U. of London /Regensburg U. /Republica U., Montevideo /Frascati /INFN, Rome /INFN, Rome /INFN, Rome /Rutherford /Sassari U. /Siegen U. /SLAC /Southern Methodist U. /Tel Aviv U. /Tohoku U. /INFN, Turin /INFN, Trieste /Uppsala U. /Valencia U., IFIC /Victoria U. /Wayne State U. /Wisconsin U., Madison


    SuperB is a high luminosity e{sup +}e{sup -} collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measurements that can be made at SuperB play a pivotal role in understanding the nature of physics beyond the Standard Model. Examples for using the interplay between measurements to discriminate New Physics models are discussed in this document. SuperB is a Super Flavour Factory, in addition to studying large samples of B{sub u,d,s}, D and {tau} decays, SuperB has a broad physics programme that includes spectroscopy both in terms of the Standard Model and exotica, and precision measurements of sin{sup 2} {theta}{sub W}. In addition to performing CP violation measurements at the {Upsilon}(4S) and {phi}(3770), SuperB will test CPT in these systems, and lepton universality in a number of different processes. The multitude of rare decay measurements possible at SuperB can be used to constrain scenarios of physics beyond the Standard Model. In terms of other precision tests of the Standard Model, this experiment will be able to perform precision over

  10. Experiments with SuperJANET/SMDS


    Simpson, Steven; Hutchison, David


    A series of measurements of a computer link using the Switched Multimegabit Data Service (SMDS), as provided in the United Kingdom SuperJANET network, are described in this paper. The computer link is subject to the effects of using several access networks at the peripheries of SuperJANET, making the measurements valid only in the context of the link from one computer to another, rather than describing any attributes of SuperJANET in general. However, the measurement mechanism is refined seve...

  11. Tracheotomy Outcomes in Super Obese Patients. (United States)

    Marshall, Ryan V; Haas, Patrick J; Schweinfurth, John M; Replogle, William H


    Surgeons need to understand the expected outcomes for super obese patients undergoing tracheotomy to appropriately counsel patients and families about likely risks and benefits. To determine the outcomes, complications, and mortality after tracheotomy in super obese patients (those with a body mass index [BMI] greater than 50). A retrospective review was conducted of billing records from a tertiary care academic medical center from November 1, 2010, through June 30, 2013, to identify patients undergoing tracheotomy. Medical records were reviewed to identify patients with a BMI (calculated as weight in kilograms divided by height in meters squared) greater than 50 and a control group with a BMI of 30 to 50. Patient characteristics, including BMI, age, race/ethnicity, primary diagnosis for hospitalization, medical comorbidities, and surgical technique, were measured. The primary outcome measure was dependence on tracheostomy at discharge. Secondary outcomes included rates of ventilator dependence, mortality, postoperative complications, and discharge disposition. The super obese population included 31 patients and was predominantly African American (20 patients [65%]) and female (21 patients [68%]). Mean BMI of super obese patients was 64.0 (range, 50.2-95.5). The obese patient population was mainly African American (25 patients [74%]) and female (17 patients [50%]). Twenty-five of 31 super obese patients (81%) were discharged with a tracheotomy tube in place, compared with 16 of 34 obese patients (52%). Seven patients (23%) in the super obese group were ventilator dependent at discharge, compared with 4 patients (13%) in the obese group. Only 2 of the super obese patients (3%) were decannulated before discharge, compared with 15 (44%) in the obese group. In-hospital mortality was similar for the 2 groups (super obese, 4 patients [13%] and obese, 3 patients [9%]). The overall complication rate was 19% in the super obese group (6 patients) compared with 6% in the

  12. Formulation strategy towards minimizing viscosity mediated negative food effect on disintegration and dissolution of immediate release tablets. (United States)

    Zaheer, Kamran; Langguth, Peter


    Food induced viscosity can delay disintegration and subsequent release of API from solid dosage form which may lead to severe reduction in the bioavailability of BCS type III compounds. Formulations of such tablets need to be optimized in view of this postprandial viscosity factor. In this study, three super disintegrants, croscarmellose sodium (CCS), cross-linked polyvinylpolypyrrolidone (CPD), and sodium starch glycolate (SSG) were assessed for their efficiency under simulated fed state. Tablets containing these disintegrants were compressed at 10 and 30 KN, while taking lactose as a soluble filler. In addition to other compendial tests, disintegration force of these formulations was measured by texture analysis. Comparison of parameters derived from force - time curves revealed a direct relation of maximum disintegration force (F max ) and disintegration force development rate (DFDR) with compressional force in fasted state, whereas an inverse relationship of F max and DFDR with compressional force was observed in fed state. The gelling tendency of disintegrants influenced the rate of release of API in simulated fed and fasted states when compressional force was changed. These observations recommend the evaluation of formulations in simulated fed state, in the development stage, with an objective of minimizing the negative impact of food induced viscosity on disintegration. Use of disintegrants that act without gelling or can counteract the effect of gelling is recommended for tablet formulations with reduced disintegration time (DT) and mean dissolution time (MDT) in fed state, respectively.

  13. Decorrelation-based viscosity measurement using phase-sensitive optical coherence tomography (Conference Presentation) (United States)

    Blackburn, Brecken J.; Gu, Shi; Jenkins, Michael W.; Rollins, Andrew M.


    A robust method to measure viscosity of microquantities of biological samples, such as blood and mucus, could lead to a better understanding and diagnosis of diseases. Microsamples have presented persistent challenges to conventional rheology, which requires bulk quantities of a sample. Alternatively, fluid viscosity can be probed by monitoring microscale motion of particles. Here, we present a decorrelation-based method using M-mode phase-sensitive optical coherence tomography (OCT) to measure particle Brownian motion. This is similar to previous methods using laser speckle decorrelation but with sensitivity to nanometer-scale displacement. This allows for the measurement of decorrelation in less than 1 millisecond and significantly decreases sensitivity to bulk motion, thereby potentially enabling in vivo and in situ applications. From first principles, an analytical method is established using M-mode images obtained from a 47 kHz spectral-domain OCT system. A g(1) first-order autocorrelation is calculated from windows containing several pixels over a time frame of 200-1000 microseconds. Total imaging time is 500 milliseconds for averaging purposes. The autocorrelation coefficient over this short time frame decreases linearly and at a rate proportional to the diffusion constant of the particles, allowing viscosity to be calculated. In verification experiments using phantoms of microbeads in 200 µL glycerol-water mixtures, this method showed insensitivity to 2 mm/s lateral bulk motion and accurate viscosity measurements over a depth of 400 µm. In addition, the method measured a significant decrease of the apparent diffusion constant of soft tissue after formalin fixation, suggesting potential applications in mapping tissue stiffness.

  14. Possible Range of Viscosity Parameters to Trigger Black Hole Candidates to Exhibit Different States of Outbursts (United States)

    Mondal, Santanu; Chakrabarti, Sandip K.; Nagarkoti, Shreeram; Arévalo, Patricia


    In a two component advective flow around a compact object, a high-viscosity Keplerian disk is flanked by a low angular momentum and low-viscosity flow that forms a centrifugal, pressure-supported shock wave close to the black hole. The post-shock region that behaves like a Compton cloud becomes progressively smaller during the outburst as the spectra change from the hard state (HS) to the soft state (SS), in order to satisfy the Rankine–Hugoniot relation in the presence of cooling. The resonance oscillation of the shock wave that causes low-frequency quasi-periodic oscillations (QPOs) also allows us to obtain the shock location from each observed QPO frequency. Applying the theory of transonic flow, along with Compton cooling and viscosity, we obtain the viscosity parameter {α }{SK} required for the shock to form at those places in the low-Keplerian component. When we compare the evolution of {α }{SK} for each outburst, we arrive at a major conclusion: in each source, the advective flow component typically requires an exactly similar value of {α }{SK} when transiting from one spectral state to another (e.g., from HS to SS through intermediate states and the other way around in the declining phase). Most importantly, these {α }{SK} values in the low angular momentum advective component are fully self-consistent in the sense that they remain below the critical value {α }{cr} required to form a Keplerian disk. For a further consistency check, we compute the {α }{{K}} of the Keplerian component, and find that in each of the objects, {α }{SK} < {α }{cr} < {α }{{K}}.

  15. Control of the Fluid Viscosity in a Mock Circulation. (United States)

    Boës, Stefan; Ochsner, Gregor; Amacher, Raffael; Petrou, Anastasios; Meboldt, Mirko; Schmid Daners, Marianne


    A mock circulation allows the in vitro investigation, development, and testing of ventricular assist devices. An aqueous-glycerol solution is commonly used to mimic the viscosity of blood. Due to evaporation and temperature changes, the viscosity of the solution drifts from its initial value and therefore, deviates substantially from the targeted viscosity of blood. Additionally, the solution needs to be exchanged to account for changing viscosities when mimicking different hematocrits. This article presents a method to control the viscosity in a mock circulation. This method makes use of the relationship between temperature and viscosity of aqueous-glycerol solutions and employs the automatic control of the viscosity of the fluid. To that end, an existing mock circulation was extended with an industrial viscometer, temperature probes, and a heating nozzle band. The results obtained with different fluid viscosities show that a viscosity controller is vital for repeatable experimental conditions on mock circulations. With a mixture ratio of 49 mass percent of aqueous-glycerol solution, the controller can mimic a viscosity range corresponding to a hematocrit between 29 and 42% in a temperature range of 30-42°C. The control response has no overshoot and the settling time is 8.4 min for a viscosity step of 0.3 cP, equivalent to a hematocrit step of 3.6%. Two rotary blood pumps that are in clinical use are tested at different viscosities. At a flow rate of 5 L/min, both show a deviation of roughly 15 and 10% in motor current for high rotor speeds. The influence of different viscosities on the measured head pressure is negligible. Viscosity control for a mock circulation thus plays an important role for assessing the required motor current of ventricular assist devices. For the investigation of the power consumption of rotary blood pumps and the development of flow estimators where the motor current is a model input, an integrated viscosity controller is a valuable

  16. Acoustic Design of Super-light Structures

    DEFF Research Database (Denmark)

    Christensen, Jacob Ellehauge; Hertz, Kristian Dahl; Brunskog, Jonas

    in a controlled laboratory environment have been conducted with the element in order to evaluate its performance in airborne and impact sound insulation. These results have been employed in simulations of the flanking transmission to estimate the in-situ performance of the super-light slab element. The flanking...... transmission has been done both in a standard room consisting of precast concrete elements and as a parametric study in order to estimate the accuracy of the used model. Experiments on the ultimate limit state regarding moment, shear and pull-out resistance is carried out for the super-light element. As a part...... of the same test series elastic behaviour of the super-light element is also investigated. This is done to verify that requirements and methods supplied by design codes can be applied to the element with sufficient accuracy. In addition, the super-light slab element has been exposed to a standard fire test...

  17. Architectural Engineering to Super-Light Structures

    DEFF Research Database (Denmark)

    Castberg, Niels Andreas

    with architectural engineering as a starting point. The thesis is based on a two stringed hypothesis: Architectural engineering gives rise to better architecture and Super-Light Structures support and enables a static, challenging architecture. The aim of the thesis is to clarify architectural engineering's impact...... on the work process between architects and engineers in the design development. Using architectural engineering, Super-Light Structures are examined in an architectural context, and it is explained how digital tools can support architectural engineering and design of Super-Light Structures. The experiences...... of implementing a new structural system are described, as well as cases, demonstrating how concept solutions with Super-Light Structures can support architecture. The research in this thesis is carried out in cooperation with architect practice Bjarke Ingels Group (BIG), who has allowed the projects...

  18. Axial Super-resolution Evanescent Wave Tomography

    CERN Document Server

    Pendharker, Sarang; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin


    Optical tomographic reconstruction of a 3D nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography (AxSET) method that enables the use of regular evanescent wave microscopes like Total Internal Reflection Fluorescence Microscope (TIRF) beyond surface imaging, and achieve tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of three-dimensional fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by 1D (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axi...

  19. Super-resolution imaging in live cells

    National Research Council Canada - National Science Library

    Cox, Susan

    Over the last twenty years super-resolution fluorescence microscopy has gone from proof-of-concept experiments to commercial systems being available in many labs, improving the resolution achievable...

  20. The Super-TIGER Instrument to Probe Galactic Cosmic Ray Origins (United States)

    Mitchell, John W.; Binns, W. R.; Bose, R, G.; Braun, D. L.; Christian, E. R.; Daniels, W. M; DeNolfo, G. A.; Dowkontt, P. F.; Hahne, D. J.; Hams, T.; hide


    Super-TIGER (Super Trans-Iron Galactic Element Recorder) is under construction for the first of two planned Antarctic long-duration balloon flights in December 2012. This new instrument will measure the abundances of ultra-heavy elements (30Zn and heavier), with individual element resolution, to provide sensitive tests of the emerging model of cosmic-ray origins in OB associations and models of the mechanism for selection of nuclei for acceleration. Super-TIGER builds on the techniques of TIGER, which produced the first well-resolved measurements of elemental abundances of the elements 31Ga, 32Ge, and 34Se. Plastic scintillators together with acrylic and silica-aerogel Cherenkov detectors measure particle charge. Scintillating-fiber hodoscopes track particle trajectories. Super-TIGER has an active area of 5.4 sq m, divided into two independent modules. With reduced material thickness to decrease interactions, its effective geometry factor is approx.6.4 times larger than TIGER, allowing it to measure elements up to 42Mo with high statistical precision, and make exploratory measurements up to 56Ba. Super-TIGER will also accurately determine the energy spectra of the more abundant elements from l0Ne to 28Ni between 0.8 and 10 GeV/nucleon to test the hypothesis that microquasars or other sources could superpose spectral features. We will discuss the implications of Super-TIGER measurements for the study of cosmic-ray origins and will present the measurement technique, design, status, and expected performance, including numbers of events and resolution. Details of the hodoscopes, scintillators, and Cherenkov detectors will be given in other presentations at this conference.

  1. Sustainable composite super absorbents made from polysaccharides


    Ye, Zhuoliang; Tang, Mi; Hong, Xiaoting; K. S. Hui


    Compared to traditional super absorbent polymers using raw materials from petrochemical industry, natural polymer absorbents are more favorable because they are sustainable and biodegradable. In this study, composite absorbents were developed by crosslinking carrageenan with sodium alginate using calcium chloride. Effect of composition on absorption was tested. Absorption was improved by increasing carrageenan content. The super absorbent exhibited the maximal swelling ratio of 13.1 g/g in 0....

  2. Evaluation of Relative Blood Viscosity During Menstruation in ...

    African Journals Online (AJOL)


    ABSTRACT. The changes in blood viscosity, plasma viscosity, haematocrit and erythrocyte sedimentation rate before ... Blood samples were collected during two ..... Gynaecol., 91(7): 685–. 690. Logan, P. and Carolyn, C.(1997).Take Your. Choice. Counterbalance: Gendered. Perspectives on Writing and Language. Pp. 41.

  3. On-line measurement of food viscosity during flow

    DEFF Research Database (Denmark)

    Mason, Sarah Louise; Friis, Alan


    Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time.......Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time....

  4. The relationship between plasma viscosity and Body Mass Index in ...

    African Journals Online (AJOL)

    Plasma viscosity is one of the most important rheological parameters for assessing the health status of an individual. It is influenced by diseases with alteration in plasma protein composition and previous studies have shown that the viscosity of plasma is affected by various factors which includes body weight, fibrinogen ...

  5. Viscosity of liquids theory, estimation, experiment, and data

    CERN Document Server

    Viswanath, Dabir S; Prasad, Dasika HL; Dutt, Nidamarty VK; Rani, Kalipatnapu Y


    Single comprehensive book on viscosity of liquids, as opposed to most of the books in this area which are data books, i.e., a compilation of viscosity data from the literature, where the information is scattered and the description and analysis of the experimental methods and governing theory are not readily available in a single place.

  6. Nonlinear Eddy Viscosity Models applied to Wind Turbine Wakes

    DEFF Research Database (Denmark)

    Laan, van der, Paul Maarten; Sørensen, Niels N.; Réthoré, Pierre-Elouan


    The linear k−ε eddy viscosity model and modified versions of two existing nonlinear eddy viscosity models are applied to single wind turbine wake simulations using a Reynolds Averaged Navier-Stokes code. Results are compared with field wake measurements. The nonlinear models give better results...

  7. Effective viscosity of dispersions approached by a statistical continuum method

    NARCIS (Netherlands)

    Mellema, J.; Willemse, M.W.M.


    The problem of the determination of the effective viscosity of disperse systems (emulsions, suspensions) is considered. On the basis of the formal solution of the equations governing creeping flow in a statistically homogeneous dispersion, the effective viscosity is expressed in a series expansion

  8. Relook on fitting of viscosity with undercooling of glassy liquids

    Indian Academy of Sciences (India)

    The present approach is on the modification of viscosity fitting of undercooled liquid as a function of undercooling. The method consists of finding analytical solution of three arbitrary constants of the Vogel–Fulcher–Tamman (VFT) equation by choosing three viscosity data at three critical temperatures for an undercooled ...

  9. Evaluation of Relative Blood Viscosity During Menstruation in ...

    African Journals Online (AJOL)

    The changes in blood viscosity, plasma viscosity, haematocrit and erythrocyte sedimentation rate before and during menstruation were evaluated. Forty (40) apparently healthy reproductive female subjects (between 15 and 28 years) and resident in Benin City, Edo State, Nigeria were used for the study. The parameters ...

  10. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole


    The start-up and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 and 103 kg/mole, and for three bidisperse polystyrene melts. The monodisperse melts show a maximum in the steady elongational viscosity vs. the elongational...

  11. Effect of viscosity on appetite and gastro-intestinal hormones

    NARCIS (Netherlands)

    Zijlstra, N.; Mars, M.; Wijk, de R.A.; Westerterp-Plantenga, M.S.; Holst, J.J.; Graaf, de C.


    In previous studies we showed that higher viscosity resulted in lower ad libitum intake and that eating rate is an important factor. In this study we aimed to explore the effect of viscosity on the gastro-intestinal hormones ghrelin, CCK-8 and GLP-1. Thirty-two subjects (22 ± 2 y, BMI 21.9 ± 2.2

  12. Effect of viscosity on droplet-droplet collisional interaction

    NARCIS (Netherlands)

    Finotello, Giulia; Padding, J.T.; Deen, Niels G.; Jongsma, Alfred; Innings, Fredrik; Kuipers, J.A.M.


    A complete knowledge of the effect of droplet viscosity on droplet-droplet collision outcomes is essential for industrial processes such as spray drying. When droplets with dispersed solids are dried, the apparent viscosity of the dispersed phase increases by many orders of magnitude, which

  13. Poiseuille flow to measure the viscosity of particle model fluids.

    NARCIS (Netherlands)

    Backer, J.A.; Lowe, C.P.; Hoefsloot, H.C.J.; Iedema, P.D.


    The most important property of a fluid is its viscosity, it determines the flow properties. If one simulates a fluid using a particle model, calculating the viscosity accurately is difficult because it is a collective property. In this article we describe a new method that has a better signal to

  14. A Riemann problem with small viscosity and dispersion

    Directory of Open Access Journals (Sweden)

    Kayyunnapara Thomas Joseph


    Full Text Available In this paper we prove existence of global solutions to a hyperbolic system in elastodynamics, with small viscosity and dispersion terms and derive estimates uniform in the viscosity-dispersion parameters. By passing to the limit, we prove the existence of solution the Riemann problem for the hyperbolic system with arbitrary Riemann data.

  15. Studies of the Super VELO

    CERN Document Server



    The Super VELO is the Run 5 upgrade of the VeloPix detector of the LHCb experiment. Its most challenging task is to cope with a luminosity increase of the factor 10. This study examines the potential physics performance of a detector based on the VeloPix design at high luminosity conditions. It is found that an unmodified VeloPix detector shows poor performance when exposed to 10x design luminosity, most gravely high ghost rates of 40 %. When applying basic assumptions about material changes such as cutting the silicon thickness by half and removing the RF foil, the ghost rate drops by 20 %. When using thin silicon and re-optimizing the tracking algorithm, the ghost rate can even be reduced by 60 %. Applying the additional modification of a pixel area size four times smaller, the ghost rate drops by 88 % and the IP resolution improves. Finally, in a dream scenario with thin silicon, smaller pixels and no RF foil, big gains in resolution and a ghost rate of less than 4 % can be achieved.

  16. Super-B Project Overview

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Boni, R.; Boscolo, M.; Demma, T.; Drago, A.; Guiducci, S.; Raimondi, P.; Tomassini, S.; Zobov, M.; /Frascati; Bertsche, K.; Donald, M.; Nosochkov, Y.; Novokhatski, A.; Seeman, J.; Sullivan, M.; Yocky, G.; Wienands, U.; Wittmer, W.; /SLAC; Koop, I.; Levichev, E.; Nikitin, S.; /Novosibirsk, IYF /KEK, Tsukuba /Pisa U. /CERN


    The SuperB project aims at the construction of an asymmetric very high luminosity B-Factory on the Frascati/Tor Vergata (Italy) area, providing a uniquely sensitive probe of New Physics in the flavour sector of the Standard Model. The luminosity goal of 10{sup 36} cm{sup -2} s{sup -1} can be reached with a new collision scheme with 'large Piwinski angle' (LPA) and the use of 'crab waist sextupoles' (CW). A LPA&CW Interaction Region (IR) has been successfully tested at the DA{Phi}NE {Phi}-Factory at LNF-Frascati in 2008. The LPA&CW scheme, together with very low {beta}*, will allow for operation with relatively low beam currents and reasonable bunch length, comparable to those of PEP-II and KEKB. In the High Energy Ring (HER), two spin rotators will bring longitudinally polarized beams into collision at the IP. The lattice has been designed with a very low intrinsic emittance and is quite compact, less than 2 km long. The tight focusing requires the final doublet quadrupoles to be very close to the IP and very compact. A Conceptual Design Report was published in March 2007, and beam dynamics and collective effects R&D studies are in progress in order to publish a Technical Design Report by the end of 2010.

  17. Bulk viscosity, interaction and the viability of phantom solutions

    CERN Document Server

    Leyva, Yoelsy


    We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker (FRW) universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an imperfect fluid having bulk viscosity. We also introduce an interaction term between the dark matter and dark energy components. Considering that the bulk viscosity is proportional to the dark matter energy density and imposing a complete cosmological dynamics, we find bounds on the bulk viscosity in order to reproduce a matter-dominated era (MDE). This constraint is independent of the interaction term. Some late time phantom solutions are mathematically possible. However, the constraint imposed by a MDE restricts the interaction parameter, in the phantom solutions, to a region consistent with a null value, eliminating the possibility of late time stable solutions with $w<-1$. From the different cases that we study, the only possible scenario, with bulk viscosity and interac...

  18. Viscosity Prediction of Natural Gas Using the Friction Theory

    DEFF Research Database (Denmark)

    Zeberg-Mikkelsen, Claus Kjær; Cisneros, Sergio; Stenby, Erling Halfdan


    Based on the concepts of the friction theory (f-theory) for viscosity modeling, a procedure is introduced for predicting the viscosity of hydrocarbon mixtures rich in one component, which is the case for natural gases. In this procedure, the mixture friction coefficients are estimated with mixing...... rules based on the values of the pure component friction coefficients. Since natural gases contain mainly methane, two f-theory models are combined, where the friction coefficients of methane are estimated by a seven-constant f-theory model directly fitted to methane viscosities, and the friction...... coefficients of the other components are estimated by the one-parameter general f-theory model. The viscosity predictions are performed with the SRK, the PR, and the PRSV equations of state, respectively. For recently measured viscosities of natural gases, the resultant AAD (0.5 to 0.8%) is in excellent...

  19. Influence of Functional Groups on the Viscosity of Organic Aerosol. (United States)

    Rothfuss, Nicholas E; Petters, Markus D


    Organic aerosols can exist in highly viscous or glassy phase states. A viscosity database for organic compounds with atmospherically relevant functional groups is compiled and analyzed to quantify the influence of number and location of functional groups on viscosity. For weakly functionalized compounds the trend in viscosity sensitivity to functional group addition is carboxylic acid (COOH) ≈ hydroxyl (OH) > nitrate (ONO2) > carbonyl (CO) ≈ ester (COO) > methylene (CH2). Sensitivities to group addition increase with greater levels of prior functionalization and decreasing temperature. For carboxylic acids a sharp increase in sensitivity is likely present already at the second addition at room temperature. Ring structures increase viscosity relative to linear structures. Sensitivities are correlated with analogously derived sensitivities of vapor pressure reduction. This may be exploited in the future to predict viscosity in numerical models by piggybacking on schemes that track the evolution of organic aerosol volatility with age.

  20. Study on lubricating oil characteristics using viscosity index

    Energy Technology Data Exchange (ETDEWEB)

    Suwanprateep, T.

    The objective of this research is to investigate the characteristics of lubricating oil sold in the market by using viscosity index. The lubricating oil of both single grade and multigrade of some trade names for gasoline engines and one without trade name are used in the test and the viscosity index is determined for each type. The test shows that every type of lubricating oil with trade name has viscosity index of more than 100, the highest standard value, and the multigrade oil has more viscosity index than the single grade oil. The oil without trade name has viscosity index rather low and therefore is not suitable for lubrication over a wide range of working temperature, such as in gasoline engines.

  1. Measurement and correlation of jet fuel viscosities at low temperatures (United States)

    Schruben, D. L.


    Apparatus and procedures were developed to measure jet fuel viscosity for eight current and future jet fuels at temperatures from ambient to near -60 C by shear viscometry. Viscosity data showed good reproducibility even at temperatures a few degrees below the measured freezing point. The viscosity-temperature relationship could be correlated by two linear segments when plotted as a standard log-log type representation (ASTM D 341). At high temperatures, the viscosity-temperature slope is low. At low temperatures, where wax precipitation is significant, the slope is higher. The breakpoint between temperature regions is the filter flow temperature, a fuel characteristic approximated by the freezing point. A generalization of the representation for the eight experimental fuels provided a predictive correlation for low-temperature viscosity, considered sufficiently accurate for many design or performance calculations.

  2. Measuring Solution Viscosity and its Effect on Enzyme Activity

    Directory of Open Access Journals (Sweden)

    Uribe Salvador


    Full Text Available In proteins, some processes require conformational changes involving structural domain diffusion. Among these processes are protein folding, unfolding and enzyme catalysis. During catalysis some enzymes undergo large conformational changes as they progress through the catalytic cycle. According to Kramers theory, solvent viscosity results in friction against proteins in solution, and this should result in decreased motion, inhibiting catalysis in motile enzymes. Solution viscosity was increased by adding increasing concentrations of glycerol, sucrose and trehalose, resulting in a decrease in the reaction rate of the H+-ATPase from the plasma membrane of Kluyveromyces lactis. A direct correlation was found between viscosity (&eegr; and the inhibition of the maximum rate of catalysis (V max. The protocol used to measure viscosity by means of a falling ball type viscometer is described, together with the determination of enzyme kinetics and the application of Kramers’ equation to evaluate the effect of viscosity on the rate of ATP hydrolysis by the H+-ATPase.

  3. Bulk viscosity of spin-one color superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Sa' d, Basil A.


    The bulk viscosity of several quark matter phases is calculated. It is found that the effect of color superconductivity is not trivial, it may suppress, or enhance the bulk viscosity depending on the critical temperature and the temperature at which the bulk viscosity is calculated. Also, is it found that the effect of neutrino-emitting Urca processes cannot be neglected in the consideration of the bulk viscosity of strange quark matter. The results for the bulk viscosity of strange quark matter are used to calculate the r-mode instability window of quark stars with several possible phases. It is shown that each possible phase has a different structure for the r-mode instability window. (orig.)

  4. Integrated Solvent Design for CO2 Capture and Viscosity Tuning

    Energy Technology Data Exchange (ETDEWEB)

    Cantu Cantu, David; Malhotra, Deepika; Koech, Phillip K.; Heldebrant, David J.; Zheng, Feng; Freeman, Charles J.; Rousseau, Roger J.; Glezakou, Vassiliki-Alexandra


    We present novel design strategies for reduced viscosity single-component, water-lean CO2 capture organic solvent systems. Through molecular simulation, we identify the main molecular-level descriptor that influences bulk solvent viscosity. Upon loading, a zwitterionic structure forms with a small activation energy of ca 16 kJ/mol and a small stabilization of ca 6 kJ/mol. Viscosity increases exponentially with CO2 loading due to hydrogen-bonding between neighboring Zwitterions. We find that molecular structures that promote internal hydrogen bonding (within the same molecule) and suppress interactions with neighboring molecules have low viscosities. In addition, tuning the acid/base properties leads to a shift of the equilibrium toward a non-charged (acid) form that further reduces the viscosity. Based on the above structural criteria, a reduced order model is also presented that allows for the quick screening of large compound libraries and down selection of promising candidates for synthesis and testing.

  5. Effects of fluid viscosity on a moving sonoluminescing bubble. (United States)

    Sadighi-Bonabi, Rasoul; Mirheydari, Mona; Rezaee, Nastaran; Ebrahimi, Homa


    Based on the quasi-adiabatic model, the parameters of the bubble interior for a moving single bubble sonoluminescence in water, adiponitrile, and N-methylformamide are calculated for various fluid viscosities. By using a complete form of the hydrodynamic force, the bubble trajectory is calculated for a moving single bubble sonoluminescence (m-SBSL). It is found that as the fluid viscosity increases, the unique circular path changes to an ellipsoidal and then linear form and along this incrementally increase of viscosity the light intensity increases. By using the Bremsstrahlung model to describe the bubble radiation, gradual increase of the viscosity results in brighter emissions. It is found that in fluids with higher viscosity the light intensity decreases as time passes.

  6. Variation of the apparent viscosity of thickened drinks. (United States)

    O'Leary, Mark; Hanson, Ben; Smith, Christina H


    In dysphagia care, thickening powders are widely added to drinks to slow their flow speed by increasing their viscosity. Current practice relies on subjective evaluation of viscosity using verbal descriptors. Several brands of thickener are available, with differences in constituent ingredients and instructions for use. Some thickened fluids have previously been shown to exhibit time-varying non-Newtonian flow behaviour, which may complicate attempts at subjective viscosity judgement. The aims were to quantify the apparent viscosity over time produced by thickeners having a range of constituent ingredients, and to relate the results to clinical practice. A comparative evaluation of currently available thickener products, including two which have recently been reformulated, was performed. Their subjective compliance to the National Descriptors standards was assessed, and their apparent viscosity was measured using a rheometer at shear rates representative of situations from slow tipping in a beaker (0.1 s⁻¹) to a fast swallow (100 s⁻¹). Testing was performed repeatedly up to 3 h from mixing. When mixed with water, it was found that most products compared well with subjective National Descriptors at three thickness levels. The fluids were all highly non-Newtonian; their apparent viscosity was strongly dependent on the rate of testing, typically decreasing by a factor of almost 100 as shear rate increased. All fluids showed some change in viscosity with time from mixing; this varied between products from -34% to 37% in the tests. This magnitude was less than the difference between thickness levels specified by the National Descriptors. The apparent viscosity of thickened fluids depends strongly on the shear rate at which it is examined. This inherent behaviour is likely to hinder subjective evaluation of viscosity. If quantitative measures of viscosity are required (for example, for standardization purposes), they must therefore be qualified with information of

  7. Effects of Metal Ions on Viscosity of Aqueous Sodium Carboxylmethylcellulose Solution and Development of Dropping Ball Method on Viscosity (United States)

    Set, Seng; Ford, David; Kita, Masakazu


    This research revealed that metal ions with different charges could significantly affect the viscosity of aqueous sodium carboxylmethylcellulose (CMC) solution. On the basis of an Ostwald viscometer, an improvised apparatus using a dropping ball for examining the viscosity of liquids/solutions has been developed. The results indicate that the…

  8. Phenomenological and statistical analyses of turbulence in forced convection with temperature-dependent viscosity under non-Boussinesq condition. (United States)

    Yahya, S M; Anwer, S F; Sanghi, S


    In this work, Thermal Large Eddy Simulation (TLES) is performed to study the behavior of weakly compressible Newtonian fluids with anisotropic temperature-dependent viscosity in forced convection turbulent flow. A systematic analysis of variable-viscosity effects, isolated from gravity, with relevance to industrial cooling/heating applications is being carried out. A LES of a planar channel flow with significant heat transfer at a low Mach number was performed to study effects of fluid property variation on the near-wall turbulence structure. In this flow configuration the top wall is maintained at a higher temperature (T hot ) than the bottom wall (T cold ). The temperature ratio (R θ = T hot /T cold ) is fixed at 1.01, 2 and 3 to study the effects of property variations at low Mach number. Results indicate that average and turbulent fields undergo significant changes. Compared with isothermal flow with constant viscosity, we observe that turbulence is enhanced in the cold side of the channel, characterized by locally lower viscosity whereas a decrease of turbulent kinetic energy is found at the hot wall. The turbulent structures near the cold wall are very short and densely populated vortices but near the hot wall there seems to be a long streaky structure or large elongated vortices. Spectral study reveals that turbulence is completely suppressed at the hot side of the channel at a large temperature ratio because no inertial zone is obtained (i.e. index of Kolmogorov scaling law is zero) from the spectra in these region.

  9. All-optical OFDM demultiplexing by spectral magnification and optical band-pass filtering

    DEFF Research Database (Denmark)

    Palushani, Evarist; Mulvad, Hans Christian Hansen; Kong, Deming


    We propose spectral magnification of optical-OFDM super-channels using time-lenses, enabling reduced inter-carrier-interference in subcarrier detection by simple band-pass filtering. A demonstration on an emulated 100 Gbit/s DPSK optical-OFDM channel shows improved sensitivities after 4-times...

  10. Multiple Disk Gaps and Rings Generated by a Single Super-Earth (United States)

    Dong, Ruobing; Li, Shengtai; Chiang, Eugene; Li, Hui


    We investigate the observational signatures of super-Earths (I.e., planets with Earth-to-Neptune mass), which are the most common type of exoplanet discovered to date, in their natal disks of gas and dust. Combining two-fluid global hydrodynamics simulations with a radiative transfer code, we calculate the distributions of gas and of submillimeter-sized dust in a disk perturbed by a super-Earth, synthesizing images in near-infrared scattered light and the millimeter-wave thermal continuum for direct comparison with observations. In low-viscosity gas (α ≲ {10}-4), a super-Earth opens two annular gaps to either side of its orbit by the action of Lindblad torques. This double gap and its associated gas pressure gradients cause dust particles to be dragged by gas into three rings: one ring sandwiched between the two gaps, and two rings located at the gap edges farthest from the planet. Depending on the system parameters, additional rings may manifest for a single planet. A double gap located at tens of au from a host star in Taurus can be detected in the dust continuum by the Atacama Large Millimeter Array (ALMA) at an angular resolution of ˜0\\buildrel{\\prime\\prime}\\over{.} 03 after two hours of integration. Ring and gap features persist in a variety of background disk profiles, last for thousands of orbits, and change their relative positions and dimensions depending on the speed and direction of planet migration. Candidate double gaps have been observed by ALMA in systems such as HL Tau (D5 and D6) and TW Hya (at 37 and 43 au); we submit that each double gap is carved by one super-Earth in nearly inviscid gas.

  11. Influence of Febrile Neutropenia Period on Plasma Viscosity at Malignancy

    Directory of Open Access Journals (Sweden)

    Ibrahim Tek


    Full Text Available Cancer, chemotherapy, and infections all together make changes in blood rheology and may affect the defense mechanisms by changing the thrombocyte function and endothelial cell. We have examined changes of blood rheology on plasma viscosity to put on probable following criteria for starting the treatment of febrile neutropenia immediately. A total of 27 postchemotherapy patients (16 males and 11 females with febrile neutropenia diagnosed according to international guidelines have been included into the study. The plasma viscosity of the patients whose febrile neutropenia has been successfully treated was also measured to assess the impact of the duration of neutropenia on viscosity. The plasma viscosities of the patients were significantly higher during neutropenic episode than in nonneutropenic state ( except for alkaline phosphatase. All study parameters, particularly acute phase reactants, were statistically similar during both states. In the correlation of analysis with study parameters and stages, significant correlation was not observed between plasma viscosity alteration and leukocyte-neutrophil alteration, also other study parameters. We have demonstrated significantly elevated plasma viscosity in our patients during febrile neutropenic episode. Despite normal values of various parameters known to trigger plasma viscosity, particularly fibrinogen, it can be easily argued that the main mechanism may be the endothelial injury during infectious process and immune response mediated microcirculatory blood flow alterations.

  12. Compressive Spectral Renormalization Method

    CERN Document Server

    Bayindir, Cihan


    In this paper a novel numerical scheme for finding the sparse self-localized states of a nonlinear system of equations with missing spectral data is introduced. As in the Petviashivili's and the spectral renormalization method, the governing equation is transformed into Fourier domain, but the iterations are performed for far fewer number of spectral components (M) than classical versions of the these methods with higher number of spectral components (N). After the converge criteria is achieved for M components, N component signal is reconstructed from M components by using the l1 minimization technique of the compressive sampling. This method can be named as compressive spectral renormalization (CSRM) method. The main advantage of the CSRM is that, it is capable of finding the sparse self-localized states of the evolution equation(s) with many spectral data missing.

  13. Kinematic viscosity of unstimulated whole saliva in healthy young adults. (United States)

    Foglio-Bonda, A; Pattarino, F; Foglio-Bonda, P L


    To analyze kinematic viscosity and pH of unstimulated whole saliva, evaluate possible variations after sampling, identify any gender differences and detect possible correlations between them. The sample consisted of sixty-four healthy young adults (37 females and 27 males, mean age 25.2 years). Saliva was collected using the spitting method at 11:00 am. Kinematic viscosity was determined with a capillary viscometer (ViscoClock, Schott-Geräte Mainz, Germany) equipped with a micro-Ubbelohde capillary. Viscosity and pH were measured at a temperature of 36 °C in a thermostatic bath. Viscosity and pH data were evaluated almost simultaneously at six different times after sampling in order to identify any variations due to aging. The data were statistically analyzed using Student's t test and Wilcoxon-Mann-Whitney test. In total sample kinematic viscosity was 1.40 cSt (SD = 0.39; RSD % = 27.81), in the male and female groups was 1.33 cSt (SD = 0.35, RSD% = 26.31) and 1.45 cSt (SD = 0.41, RSD % = 28.45) respectively; the difference was not statistically significant. Viscosity decreased exponentially as a function of time after sampling then reaching a plateau around 1.12 cSt, while the pH values increased linearly. There was a trend of pH to decrease while viscosity decreases. Kinematic viscometry could be a valid tool to evaluate salivary viscosity. Degradation of saliva after sampling affects viscosity and slightly pH. The use of capillary viscometer to evaluate salivary aging needs more improvements. Further studies are required to investigate and explain the effects of different techniques to reduce the film forming on the air/liquid interface during measurement.

  14. Spectral Mapping at Asteroid 101955 Bennu (United States)

    Clark, Beth Ellen; Hamilton, Victoria E.; Emery, Joshua P.; Hawley, C. Luke; Howell, Ellen S.; Lauretta, Dante; Simon, Amy A.; Christensen, Philip R.; Reuter, Dennis


    The OSIRIS-REx Asteroid Sample Return mission was launched in September 2016. The main science surveys of asteroid 101955 Bennu start in March 2019. Science instruments include a Visible-InfraRed Spectrometer (OVIRS) and a Thermal Emission Spectrometer (OTES) that will produce observations that will be co-registered to the tessellated shape model of Bennu (the fundamental unit of which is a triangular facet). One task of the science team is to synthesize the results in real time during proximity operations to contribute to selection of the sampling site. Hence, we will be focused on quickly producing spectral maps for: (1) mineral abundances; (2) band strengths of minerals and chemicals (including a search for the subtle ~5% absorption feature produced by organics in meteorites); and (3) temperature and thermal inertia values. In sum, we will be producing on the order of ~60 spectral maps of Bennu’s surface composition and thermophysical properties. Due to overlapping surface spots, simulations of our spectral maps show there may be an opportunity to perform spectral super-resolution. We have a large parameter space of choices available in creating spectral maps of Bennu, including: (a) mean facet size (shape model resolution), (b) percentage of overlap between subsequent spot measurements, (c) the number of spectral spots measured per facet, and (d) the mathematical algorithm used to combine the overlapping spots (or bin them on a per-facet basis). Projection effects -- caused by irregular sampling of an irregularly shaped object with circular spectrometer fields-of-view and then mapping these circles onto triangular facets -- can be intense. To prepare for prox ops, we are simulating multiple mineralogical “truth worlds” of Bennu to study the projection effects that result from our planned methods of spectral mapping. This presentation addresses: Can we combine the three planned global surveys of the asteroid (to be obtained at different phase angles) to

  15. Discontinuous Galerkin method with Gaussian artificial viscosity on graphical processing units for nonlinear acoustics (United States)

    Tripathi, Bharat B.; Marchiano, Régis; Baskar, Sambandam; Coulouvrat, François


    Propagation of acoustical shock waves in complex geometry is a topic of interest in the field of nonlinear acoustics. For instance, simulation of Buzz Saw Noice requires the treatment of shock waves generated by the turbofan through the engines of aeroplanes with complex geometries and wall liners. Nevertheless, from a numerical point of view it remains a challenge. The two main hurdles are to take into account the complex geometry of the domain and to deal with the spurious oscillations (Gibbs phenomenon) near the discontinuities. In this work, first we derive the conservative hyperbolic system of nonlinear acoustics (up to quadratic nonlinear terms) using the fundamental equations of fluid dynamics. Then, we propose to adapt the classical nodal discontinuous Galerkin method to develop a high fidelity solver for nonlinear acoustics. The discontinuous Galerkin method is a hybrid of finite element and finite volume method and is very versatile to handle complex geometry. In order to obtain better performance, the method is parallelized on Graphical Processing Units. Like other numerical methods, discontinuous Galerkin method suffers with the problem of Gibbs phenomenon near the shock, which is a numerical artifact. Among the various ways to manage these spurious oscillations, we choose the method of parabolic regularization. Although, the introduction of artificial viscosity into the system is a popular way of managing shocks, we propose a new approach of introducing smooth artificial viscosity locally in each element, wherever needed. Firstly, a shock sensor using the linear coefficients of the spectral solution is used to locate the position of the discontinuities. Then, a viscosity coefficient depending on the shock sensor is introduced into the hyperbolic system of equations, only in the elements near the shock. The viscosity is applied as a two-dimensional Gaussian patch with its shape parameters depending on the element dimensions, referred here as Element

  16. Numerical solutions of Williamson fluid with pressure dependent viscosity

    Directory of Open Access Journals (Sweden)

    Iffat Zehra


    Full Text Available In the present paper, we have examined the flow of Williamson fluid in an inclined channel with pressure dependent viscosity. The governing equations of motion for Williamson fluid model under the effects of pressure dependent viscosity and pressure dependent porosity are modeled and then solved numerically by the shooting method with Runge Kutta Fehlberg for two types of geometries i.e., (i Poiseuille flow and (ii Couette flow. Four different cases for pressure dependent viscosity and pressure dependent porosity are assumed and the physical features of pertinent parameters are discussed through graphs.

  17. Elongational viscosity of multiarm (Pom-Pom) polystyrene

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Almdal, Kristoffer


    -Pom was estimated to have 2.5 arms on average, while the estimate is 3.3 for the asymmetric star. The molar mass of each arm is about 27 kg/mol. The melts were characterized in the linear viscoelastic regime and in non-linear elongational rheometry. The transient elongational viscosity for the Pom-Pom molecule...... it corresponds well with an estimate of the maximum stretchability of the backbone. Time-strain separability was not observed for the 'Asymmetric star' molecule at the elongation rates investigated. The transient elongational viscosity for the 'Pom-Pom' molecule went through a reproducible maximum...... in the viscosity at the highest elongational rate....

  18. Structural Origin of Shear Viscosity of Liquid Water. (United States)

    Yamaguchi, Tsuyoshi


    The relation between the microscopic structure and shear viscosity of liquid water was analyzed by calculating the cross-correlation between the shear stress and the two-body density using the molecular dynamics simulation. The slow viscoelastic relaxation that dominates the steady-state shear viscosity was ascribed to the destruction of the hydrogen-bonding network structure along the compression axis of the shear distortion, which resembles the structural change under isotropic hydrostatic compression. It means that the shear viscosity of liquid water reflects the anisotropic destruction-formation dynamics of the hydrogen-bonding network.

  19. Plasma viscosity increase with progression of peripheral arterial atherosclerotic disease. (United States)

    Poredos, P; Zizek, B


    Increased blood and plasma viscosity has been described in patients with coronary and peripheral arterial disease. However, the relation of viscosity to the extent of arterial wall deterioration--the most important determinant of clinical manifestation and prognosis of the disease--is not well known. Therefore, the authors studied plasma viscosity as one of the major determinants of blood viscosity in patients with different stages of arterial disease of lower limbs (according to Fontaine) and its relation to the presence of some risk factors of atherosclerosis. The study encompassed four groups of subjects: 19 healthy volunteers (group A), 18 patients with intermittent claudication up to 200 m (stage II; group B), 15 patients with critical ischemia of lower limbs (stage III and IV; group C), and 16 patients with recanalization procedures on peripheral arteries. Venous blood samples were collected from an antecubital vein without stasis for the determination of plasma viscosity (with a rotational capillary microviscometer, PAAR), fibrinogen, total cholesterol, alpha-2-macroglobulin, and glucose concentrations. In patients with recanalization procedure local plasma viscosity was also determined from blood samples taken from a vein on the dorsum of the foot. Plasma viscosity was most significantly elevated in the patients with critical ischemia (1.78 mPa.sec) and was significantly higher than in the claudicants (1.68 mPa.sec), and the claudicants also had significantly higher viscosity than the controls (1.58 mPa.sec). In patients in whom a recanalization procedure was performed, no differences in systemic and local plasma viscosity were detected, neither before nor after recanalization of the diseased artery. In all groups plasma viscosity was correlated with fibrinogen concentration (r=0.70, P < 0.01) and total cholesterol concentration (r=0.24, P < 0.05), but in group C (critical ischemia) plasma viscosity was most closely linked to the concentration of alpha-2

  20. High shear rate rheometry of low-viscosity liquids (United States)

    Lodge, Arthur S.


    A new instrument called LODGE STRESSMETER was developed to measure the shear elasticity and viscosity of general and multigrade oils at high shear rates. This will make possible the measurements of normal stress difference N1 for values of shear rate up to 5 x 10 to the 5th power is temperature of 150 C. New surprising data show (as yet unexplained) the the N1 contribution to the minimum oil film thickness could be as much as 75 percent of the contribution from viscosity. This raises hope for the use of oils with lower viscosity, leading to improved fuel economy and an increase in the range of motorized vehicles.

  1. Intrinsic viscosity of bead models for macromolecules and bioparticles. (United States)

    Gmachowski, L


    A new method based on the fractal dimension dependence of the hydrodynamic radius is proposed for calculation of the intrinsic viscosity of bead models. The method describes properly the viscosity increment except for elongated structures such as linear aggregates and ellipsoids. It is expected to be useful for very compact structures, for which the volume correction does not improve the results calculated by the modified Oseen tensor. The results obtained for the viscosity increment lie between the volume corrected ones and those determined by the cubic substitution procedure. They are close to the values recalculated from the falling velocities of the models analyzed.

  2. A Fundamentally New SuperDARN Technique (United States)

    Gjerloev, Jesper; Waters, Colin; Barnes, Robin


    All past SuperDARN models have been based on the idea that global convection pattern is controlled by the solar wind conditions. The implied causality raises a list of questions such as: What is the delay between the cause and effect, whether the magnetosphere-ionosphere (M-I) system has inertia and whether internal M-I processes can be ignored. In this talk we answer these question by presenting a new SuperDARN technique which is based on a fundamentally different approach. The method combines historical data from the SuperDARN data base, Principal Component Analysis and a spherical cap basis function expansion process in order to `fill-in' convection data where there are observations for any given time. Our model show significant differences from all past SuperDARN models but its behavior is in excellent agreement with both the SuperMAG and AMPERE. We outline the technique, validate the solutions and show the results from a typical substorm as well as a storm event.

  3. Ending aging in super glassy polymer membranes. (United States)

    Lau, Cher Hon; Nguyen, Phuc Tien; Hill, Matthew R; Thornton, Aaron W; Konstas, Kristina; Doherty, Cara M; Mulder, Roger J; Bourgeois, Laure; Liu, Amelia C Y; Sprouster, David J; Sullivan, James P; Bastow, Timothy J; Hill, Anita J; Gin, Douglas L; Noble, Richard D


    Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Regression and Sparse Regression Methods for Viscosity Estimation of Acid Milk From it’s Sls Features

    DEFF Research Database (Denmark)

    Sharifzadeh, Sara; Skytte, Jacob Lercke; Nielsen, Otto Højager Attermann


    Statistical solutions find wide spread use in food and medicine quality control. We investigate the effect of different regression and sparse regression methods for a viscosity estimation problem using the spectro-temporal features from new Sub-Surface Laser Scattering (SLS) vision system. From...... with sparse LAR, lasso and Elastic Net (EN) sparse regression methods. Due to the inconsistent measurement condition, Locally Weighted Scatter plot Smoothing (Loess) has been employed to alleviate the undesired variation in the estimated viscosity. The experimental results of applying different methods show...... that, the sparse regression lasso outperforms other methods. In addition, the use of local smoothing has improved the results considerably for all regression methods. Due to the sparsity of lasso, this result would assist to design a simpler vision system with less spectral bands....

  5. Ultra-directional super-scattering of homogenous spherical particles with radial anisotropy

    CERN Document Server

    Liu, Wei


    We study the light scattering of homogenous radially-anisotropic spherical particles. It is shown that radial anisotropy can be employed to tune effectively the electric resonances, and thus enable flexible overlapping of electric and magnetic dipoles of various numbers, which leads to unidirectional forward super-scattering at different spectral positions. We further reveal that through adjusting the radial anisotropy parameters, electric and magnetic resonances of higher orders can be also made overlapped, thus further collimating the forward scattering lobes. The ultra-directional super-scattering we have obtained with individual homogenous radially anisotropic spherical particles may shed new light to the design of compact and efficient nanoantennas, which may find various applications in solar cells, bio-sensing and many other antenna based researches.

  6. Ultrabroadband super-Planckian radiative heat transfer with artificial continuum cavity states in patterned hyperbolic metamaterials (United States)

    Dai, Jin; Ding, Fei; Bozhevolnyi, Sergey I.; Yan, Min


    Localized cavity resonances due to nanostructures at material surfaces can greatly enhance radiative heat transfer (RHT) between two closely placed bodies owing to stretching of cavity states in momentum space beyond the light line. Based on such understanding, we numerically demonstrate the possibility of ultrabroadband super-Planckian RHT between two plates patterned with trapezoidal-shaped hyperbolic metamaterial (HMM) arrays. The phenomenon is rooted not only in HMM's high effective index for creating subwavelength resonators but also its extremely anisotropic isofrequency contour. The two properties enable one to create photonic bands with a high spectral density to populate a desired thermal radiation window. At submicron gap sizes between such two plates, the artificial continuum states extend outside the light cone, tremendously increasing overall RHT. Our study reveals that structured HMM offers unprecedented potential in achieving a controllable super-Planckian radiative heat transfer for thermal management at nanoscale.

  7. Volpe SuperFar V6.0 Software and Support Documentation; Letter Report V324-FB48B3-LR3 (United States)


    This Letter Report serves to deliver the third external release version of the USDOT Volpe Centers SuperFAR Spectral Aircraft Noise Processing Software (Version 6.0). Earlier versions of the software were delivered to FAA in February 2015 and Marc...


    National Research Council Canada - National Science Library

    I. V. Makeev; I. Y. Popov; I. V. Blinova


    .... We suggest exact particular solutions of Stokes and continuity equations with variable viscosity and density in spherical coordinates for the case of spherically symmetric viscosity and density distributions...

  9. The super period matrix with Ramond punctures (United States)

    Witten, Edward


    We generalize the super period matrix of a super Riemann surface to the case that Ramond punctures are present. For a super Riemann surface of genus g with 2 r Ramond punctures, we define, modulo certain choices that generalize those in the classical theory (and assuming a certain generic condition is satisfied), a g | r × g | r period matrix that is symmetric in the Z2-graded sense. As an application, we analyze the genus 2 vacuum amplitude in string theory compactifications to four dimensions that are supersymmetric at tree level. We find an explanation for a result that has been found in orbifold examples in explicit computations by D'Hoker and Phong: with their integration procedure, the genus 2 vacuum amplitude always vanishes "pointwise" after summing over spin structures, and hence is given entirely by a boundary contribution.

  10. Accurate viscosity measurements of flowing aqueous glucose solutions with suspended scatterers using a dynamic light scattering approach with optical coherence tomography (United States)

    Weatherbee, Andrew; Popov, Ivan; Vitkin, Alex


    The viscosity of turbid colloidal glucose solutions has been accurately determined from spectral domain optical coherence tomography (OCT) M-mode measurements and our recently developed OCT dynamic light scattering model. Results for various glucose concentrations, flow speeds, and flow angles are reported. The relative "combined standard uncertainty" uc(η) on the viscosity measurements was ±1% for the no-flow case and ±5% for the flow cases, a significant improvement in measurement robustness over previously published reports. The available literature data for the viscosity of pure water and our measurements differ by 1% (stagnant case) and 1.5% (flow cases), demonstrating good accuracy; similar agreement is seen across the measured glucose concentration range when compared to interpolated literature values. The developed technique may contribute toward eventual noninvasive glucose measurements in medicine.

  11. Measuring viscosity with nonlinear self-excited microcantilevers (United States)

    Mouro, J.; Tiribilli, B.; Paoletti, P.


    A viscosity sensor based on the nonlinear behaviour of a microcantilever embedded in a self-excitation loop with an adjustable phase-shifter is proposed. The self-sustained oscillation frequencies of the cantilever are experimentally and theoretically investigated as functions of the fluid viscosity and of the imposed phase shift of the signal along the self-excitation loop. The sensor performance is validated experimentally using different water-glycerol solutions. In contrast to existing rheological sensors, the proposed platform can be tuned to work in two different modes: a high-sensitivity device whose oscillation frequency changes smoothly with the rheological properties of the fluid or a critical viscosity threshold detector, where, for small changes in fluid viscosity, there is a step change in oscillation frequency.

  12. PVT characterization and viscosity modeling and prediction of crude oils

    DEFF Research Database (Denmark)

    Cisneros, Eduardo Salvador P.; Dalberg, Anders; Stenby, Erling Halfdan


    In previous works, the general, one-parameter friction theory (f-theory), models have been applied to the accurate viscosity modeling of reservoir fluids. As a base, the f-theory approach requires a compositional characterization procedure for the application of an equation of state (EOS), in most...... pressure, is also presented. The combination of the mass characterization scheme presented in this work and the f-theory, can also deliver accurate viscosity modeling results. Additionally, depending on how extensive the compositional characterization is, the approach,presented in this work may also...... deliver accurate viscosity predictions. The modeling approach presented in this work can deliver accurate viscosity and density modeling and prediction results over wide ranges of reservoir conditions, including the compositional changes induced by recovery processes such as gas injection....

  13. Poiseuille Flow of Fluid Whose Viscosity is Temperature Dependent ...

    African Journals Online (AJOL)

    We discuss a fluid flowing between two parallel plates. We assume a Poiseuille flow. Furthermore, we assume that the viscosity μ, depends on temperature T. We show that the velocity equation has two solutions. Graph features prominently in the presentation.

  14. Density and viscosity modeling and characterization of heavy oils

    DEFF Research Database (Denmark)

    Cisneros, Sergio; Andersen, Simon Ivar; Creek, J


    Viscosity and density are key properties for the evaluation, simulation, and development of petroleum reservoirs. Previously, the friction theory (f-theory) was shown to be capable of delivering simple and accurate viscosity models for petroleum reservoir fluids with molecular weights up to similar...... to 200 g/mol and viscosities up to similar to 10 mPa s, under usual reservoir conditions. As a basis, the f-theory approach requires a compositional characterization procedure that is used in conjunction with a van der Waals type of equation of state (EOS). This is achieved using simple cubic EOSs, which...... are widely used within the oil industry. Further work also established the basis for extending the approach to heavy oils. Thus, in this work, the extended f-theory approach is further discussed with the study and modeling of a wider set of representative heavy reservoir fluids with viscosities up...

  15. Viscosity and density tables of sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fair, J.A.; Ozbek, H. (comps.)


    A file is presented containing tabulated data extracted from the scientific literature on the density and viscosity of aqueous sodium chloride solutions. Also included is a bibliography of the properties of aqueous sodium chloride solutions. (MHR)

  16. Rotational and spin viscosities of water: Application to nanofluidics

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Bruus, Henrik; Todd, B.D.


    In this paper we evaluate the rotational viscosity and the two spin viscosities for liquid water using equilibrium molecular dynamics. Water is modeled via the flexible SPC/Fw model where the Coulomb interactions are calculated via the Wolf method which enables the long simulation times required....... We find that the rotational viscosity is independent of the temperature in the range from 284 to 319 K. The two spin viscosities, on the other hand, decrease with increasing temperature and are found to be two orders of magnitude larger than that estimated by Bonthuis et al. [Phys. Rev. Lett. 103...... geometries. The coupling also enables conversion of rotational electrical energy into fluid linear momentum and we find that in order to obtain measurable flow rates the electrical field strength must be in the order of 0.1 MV m(-1) and rotate with a frequency of more than 100 MHz....

  17. Quetol 651: Not just a low viscosity resin. (United States)

    Ellis, E Ann


    Quetol 651, a low viscosity epoxy resin, is miscible with alcohols, acetone, and water. It is versatile and can be used as a single epoxide or mixed with other epoxides and anhydrides. The most important characteristic is that the addition of Quetol 651 to a formulation results in a lower viscosity embedding medium and allows for good detection of antigenic activity. Properly formulated and mixed resins containing Quetol 651 have excellent sectioning properties and good beam stability. The decrease in viscosity lends to lower specific gravity of the embedding medium and less interfering electron density between specimen elements resulting in better spatial resolution. New formulations and viscosity data are presented and compared to long used, embedding formulations and the extensive uses of Quetol 651 are reviewed. © 2015 Wiley Periodicals, Inc.

  18. Viscosity Measurements and Correlation of the Squalane + CO2 Mixture (United States)

    Tomida, D.; Kumagai, A.; Yokoyama, C.


    Experimental results for the viscosity of squalane + CO2 mixtures are reported. The viscosities were measured using a rolling ball viscometer. The experimental temperatures were 293.15, 313.15, 333.15, and 353.15 K, and pressures were 10.0, 15.0, and 20.0 MPa. The CO2 mole fraction of the mixtures varied from 0 to 0.417. The experimental uncertainties in viscosity were estimated to be within ±3.0%. The viscosity of the mixtures decreased with an increase in the CO2 mole fraction. The experimental data were compared with predictions from the Grunberg-Nissan and McAllister equations, which correlated the experimental data with maximum deviations of 10 and 8.7%, respectively.

  19. Adaptive Spectral Doppler Estimation

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jakobsson, Andreas; Jensen, Jørgen Arendt


    In this paper, 2 adaptive spectral estimation techniques are analyzed for spectral Doppler ultrasound. The purpose is to minimize the observation window needed to estimate the spectrogram to provide a better temporal resolution and gain more flexibility when designing the data acquisition sequence...

  20. Hydrocarbon Spectral Database (United States)

    SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

  1. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    Kristensen, Leif


    It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between ...... observation sites and the turbulence intensity influence the results. The limitations of the theory are discussed....

  2. Analytical SuperSTEM for extraterrestrial materials research

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J P; Dai, Z R


    Electron-beam studies of extraterrestrial materials with significantly improved spatial resolution, energy resolution and sensitivity are enabled using a 300 keV SuperSTEM scanning transmission electron microscope with a monochromator and two spherical aberration correctors. The improved technical capabilities enable analyses previously not possible. Mineral structures can be directly imaged and analyzed with single-atomic-column resolution, liquids and implanted gases can be detected, and UV-VIS optical properties can be measured. Detection limits for minor/trace elements in thin (<100 nm thick) specimens are improved such that quantitative measurements of some extend to the sub-500 ppm level. Electron energy-loss spectroscopy (EELS) can be carried out with 0.10-0.20 eV energy resolution and atomic-scale spatial resolution such that variations in oxidation state from one atomic column to another can be detected. Petrographic mapping is extended down to the atomic scale using energy-dispersive x-ray spectroscopy (EDS) and energy-filtered transmission electron microscopy (EFTEM) imaging. Technical capabilities and examples of the applications of SuperSTEM to extraterrestrial materials are presented, including the UV spectral properties and organic carbon K-edge fine structure of carbonaceous matter in interplanetary dust particles (IDPs), x-ray elemental maps showing the nanometer-scale distribution of carbon within GEMS (glass with embedded metal and sulfides), the first detection and quantification of trace Ti in GEMS using EDS, and detection of molecular H{sub 2}O in vesicles and implanted H{sub 2} and He in irradiated mineral and glass grains.

  3. Viscosity measurements of crystallizing andesite from Tungurahua volcano (Ecuador). (United States)

    Chevrel, Magdalena Oryaëlle; Cimarelli, Corrado; deBiasi, Lea; Hanson, Jonathan B; Lavallée, Yan; Arzilli, Fabio; Dingwell, Donald B


    Viscosity has been determined during isothermal crystallization of an andesite from Tungurahua volcano (Ecuador). Viscosity was continuously recorded using the concentric cylinder method and employing a Pt-sheathed alumina spindle at 1 bar and from 1400°C to subliquidus temperatures to track rheological changes during crystallization. The disposable spindle was not extracted from the sample but rather left in the sample during quenching thus preserving an undisturbed textural configuration of the crystals. The inspection of products quenched during the crystallization process reveals evidence for heterogeneous crystal nucleation at the spindle and near the crucible wall, as well as crystal alignment in the flow field. At the end of the crystallization, defined when viscosity is constant, plagioclase is homogeneously distributed throughout the crucible (with the single exception of experiment performed at the lowest temperature). In this experiments, the crystallization kinetics appear to be strongly affected by the stirring conditions of the viscosity determinations. A TTT (Time-Temperature-Transformation) diagram illustrating the crystallization "nose" for this andesite under stirring conditions and at ambient pressure has been constructed. We further note that at a given crystal content and distribution, the high aspect ratio of the acicular plagioclase yields a shear-thinning rheology at crystal contents as low as 13 vol %, and that the relative viscosity is higher than predicted from existing viscosity models. These viscosity experiments hold the potential for delivering insights into the relative influences of the cooling path, undercooling, and deformation on crystallization kinetics and resultant crystal morphologies, as well as their impact on magmatic viscosity.

  4. Imaging viscosity of intragranular mucin matrix in cystic fibrosis cells. (United States)

    Requena, Sebastian; Ponomarchuk, Olga; Castillo, Marlius; Rebik, Jonathan; Brochiero, Emmanuelle; Borejdo, Julian; Gryczynski, Ignacy; Dzyuba, Sergei V; Gryczynski, Zygmunt; Grygorczyk, Ryszard; Fudala, Rafal


    Abnormalities of mucus viscosity play a critical role in the pathogenesis of several respiratory diseases, including cystic fibrosis. Currently, there are no approaches to assess the rheological properties of mucin granule matrices in live cells. This is the first example of the use of a molecular rotor, a BODIPY dye, to quantitatively visualize the viscosity of intragranular mucin matrices in a large population of individual granules in differentiated primary bronchial epithelial cells using fluorescence lifetime imaging microscopy.

  5. Human capability in the perception of extensional and shear viscosity. (United States)

    Lv, Zhihong; Chen, Jianshe; Holmes, Melvin


    Shear and extensional deformation are two basic rheological phenomena which occur commonly in our daily life. Because of the very different nature of the two deformations, fluid materials may exhibit significant differences in their responses to shear and extensional forces. This work investigated the human perception of shear and extensional viscosity and tested the hypothesis that human have different discriminatory sensation mechanisms including scaling to the two deformations. A series of fluid samples were prepared using two common food thickeners, guar gum and sodium carboxylmethylcellulose (CMC-Na). The shear and extensional flow behavior of these fluids were assessed using shear and extensional rheometers and in addition two separate sensory analysis sessions were organized to assess human sensitivity in perceiving the two viscosities. Magnitude estimation was used in the first session to assess human sensitivity in the perception of the shear and extensional viscosities and just-noticeable-difference (JND) assessment was used for the second session to identify the typical threshold of viscosity discrimination. For the participants considered, it was found that the perception of both shear and extensional viscosity follow a power law relationship i.e. Steven's law. It was also observed that the human has a greater discriminatory capacity in perceiving extensional viscosity. JND analysis showed that the human threshold in detecting shear viscosity difference was 9.33%, but only 6.20% for extensional viscosity. Shear and extensional deformation are two basic rheological properties which occur during food manipulation, mastication, deglutition executed during oral consumption and also in the processing and packaging of foods. Fluid resistance against shear and extensional deformation differ widely and whilst this has been confirmed theoretically and experimentally, a clear understanding of human perception of these properties will have beneficial returns to

  6. Comment on "Accelerating cosmological expansion from shear and bulk viscosity"

    CERN Document Server

    Giovannini, Massimo


    In a recent Letter [Phys. Rev. Lett. 114 091301 (2105)] the cause of the acceleration of the present Universe has been identified with the shear viscosity of an imperfect relativistic fluid even in the absence of any bulk viscous contribution. The gist of this comment is that the shear viscosity, if anything, can only lead to an accelerated expansion over sufficiently small scales well inside the Hubble radius.

  7. Effect of Fluid Dynamic Viscosity on the Strength of Chalk

    DEFF Research Database (Denmark)

    Hedegaard, K.; Fabricius, Ida Lykke

    The mechanical strength of high porosity and weakly cemented chalk is affected by the fluid in the pores. In this study, the effect of the dynamic viscosity of non-polar fluids has been measured on outcrop chalk from Sigerslev Quarry, Stevns, Denmark. The outcome is that the measured strength...... of the chalk decreases with increasing dynamic viscosity. The proposed qualitative explanation is that pressure difference supports and enhances the generation of microscopic shear and tensile failures....

  8. Convergence of a residual based artificial viscosity finite element method

    KAUST Repository

    Nazarov, Murtazo


    We present a residual based artificial viscosity finite element method to solve conservation laws. The Galerkin approximation is stabilized by only residual based artificial viscosity, without any least-squares, SUPG, or streamline diffusion terms. We prove convergence of the method, applied to a scalar conservation law in two space dimensions, toward an unique entropy solution for implicit time stepping schemes. © 2012 Elsevier B.V. All rights reserved.

  9. Viscosity measurements of crystallizing andesite from Tungurahua volcano (Ecuador) (United States)

    Cimarelli, Corrado; deBiasi, Lea; Hanson, Jonathan B.; Lavallée, Yan; Arzilli, Fabio; Dingwell, Donald B.


    Abstract Viscosity has been determined during isothermal crystallization of an andesite from Tungurahua volcano (Ecuador). Viscosity was continuously recorded using the concentric cylinder method and employing a Pt‐sheathed alumina spindle at 1 bar and from 1400°C to subliquidus temperatures to track rheological changes during crystallization. The disposable spindle was not extracted from the sample but rather left in the sample during quenching thus preserving an undisturbed textural configuration of the crystals. The inspection of products quenched during the crystallization process reveals evidence for heterogeneous crystal nucleation at the spindle and near the crucible wall, as well as crystal alignment in the flow field. At the end of the crystallization, defined when viscosity is constant, plagioclase is homogeneously distributed throughout the crucible (with the single exception of experiment performed at the lowest temperature). In this experiments, the crystallization kinetics appear to be strongly affected by the stirring conditions of the viscosity determinations. A TTT (Time‐Temperature‐Transformation) diagram illustrating the crystallization “nose” for this andesite under stirring conditions and at ambient pressure has been constructed. We further note that at a given crystal content and distribution, the high aspect ratio of the acicular plagioclase yields a shear‐thinning rheology at crystal contents as low as 13 vol %, and that the relative viscosity is higher than predicted from existing viscosity models. These viscosity experiments hold the potential for delivering insights into the relative influences of the cooling path, undercooling, and deformation on crystallization kinetics and resultant crystal morphologies, as well as their impact on magmatic viscosity. PMID:27656114

  10. KML Super Overlay to WMS Translator (United States)

    Plesea, Lucian


    This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

  11. Temporal super resolution using variational methods

    DEFF Research Database (Denmark)

    Keller, Sune Høgild; Lauze, Francois Bernard; Nielsen, Mads


    Temporal super resolution (TSR) is the ability to convert video from one frame rate to another and is as such a key functionality in modern video processing systems. A higher frame rate than what is recorded is desired for high frame rate displays, for super slow-motion, and for video/film format...... and intensities are calculated simultaneously in a multiresolution setting. A frame doubling version of our algorithm is implemented and in testing it, we focus on making the motion of high contrast edges to seem smooth and thus reestablish the illusion of motion pictures....

  12. Revisiting super-cycles in commodity prices

    Directory of Open Access Journals (Sweden)

    Fatma Pınar Erdem


    Full Text Available It is argued that business cycles have been moderating. However, there are a limited number of studies in the literature analyzing the cyclical behaviour of commodity prices in the last decades. This paper attempts to fill this gap by investigating the super-cycles in oil prices. In addition, interdependence between cycles in GDP and oil prices and co-movements between cycles in oil and other commodity prices are investigated. Results show that super-cycles in oil prices still exist and are not moderating. The last peak in long-term oil price was observed in 2012 and since then it has been on a downward trend.

  13. Pulsating stars in SuperWASP (United States)

    Holdsworth, Daniel L.


    SuperWASP is one of the largest ground-based surveys for transiting exoplanets. To date, it has observed over 31 million stars. Such an extensive database of time resolved photometry holds the potential for extensive searches of stellar variability, and provide solid candidates for the upcoming TESS mission. Previous work by e.g. [15], [5], [12] has shown that the WASP archive provides a wealth of pulsationally variable stars. In this talk I will provide an overview of the SuperWASP project, present some of the published results from the survey, and some of the on-going work to identify key targets for the TESS mission.

  14. The current status of super computers (United States)

    Knight, J. C.


    In this paper, commercially available super computers are surveyed. Computer performance in general is limited by circuit speeds and physical size. Assuming the use of the fastest technology, super computers typically use parallelism in the form of either vector processing or array processing to obtain performance. The Burroughs Scientific Processor is an array computer with 16 separate processors, the Cray-1 and CDC STAR-100 are vector processors, the Goodyear Aerospace STARAN is an array processor with up to 8192 single bit processors, and the Systems Development Corporation PEPE is a collection of up to 288 separate processors.

  15. Super-resolution near field imaging device

    DEFF Research Database (Denmark)


    Super-resolution imaging device comprising at least a first and a second elongated coupling element, each having a first transverse dimension at a first end and a second transverse dimension at a second end and being adapted for guiding light between their respective first and second ends, each...... of the matrix and the second ends of the coupling elements are located at or in a vicinity of the second side of the matrix. The second transverse dimension is larger than the first transverse dimension. A microscope objective system and a microscope comprising the super-resolution imaging device are also...

  16. A statistical approach for identifying the ionospheric footprint of magnetospheric boundaries from SuperDARN observations

    Directory of Open Access Journals (Sweden)

    G. Lointier


    Full Text Available Identifying and tracking the projection of magnetospheric regions on the high-latitude ionosphere is of primary importance for studying the Solar Wind-Magnetosphere-Ionosphere system and for space weather applications. By its unique spatial coverage and temporal resolution, the Super Dual Auroral Radar Network (SuperDARN provides key parameters, such as the Doppler spectral width, which allows the monitoring of the ionospheric footprint of some magnetospheric boundaries in near real-time. In this study, we present the first results of a statistical approach for monitoring these magnetospheric boundaries. The singular value decomposition is used as a data reduction tool to describe the backscattered echoes with a small set of parameters. One of these is strongly correlated with the Doppler spectral width, and can thus be used as a proxy for it. Based on this, we propose a Bayesian classifier for identifying the spectral width boundary, which is classically associated with the Polar Cap boundary. The results are in good agreement with previous studies. Two advantages of the method are: the possibility to apply it in near real-time, and its capacity to select the appropriate threshold level for the boundary detection.

  17. Understanding Soliton Spectral Tunneling as a Spectral Coupling Effect

    DEFF Research Database (Denmark)

    Guo, Hairun; Wang, Shaofei; Zeng, Xianglong


    between channels, here we suggest that the soliton spectral tunneling effect can be understood supported by a spectral phase coupler. The dispersive wave number in the spectral domain must have a coupler-like symmetric profile for soliton spectral tunneling to occur. We show that such a spectral coupler...

  18. Effect of viscosity on harmonic signals from magnetic fluid

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Takashi, E-mail:; Bai, Shi; Hirokawa, Aiki; Tanabe, Kazuhiro; Enpuku, Keiji


    We explored the effect of viscosity on harmonic signals from a magnetic fluid. Using a numerical simulation that accounts for both the Brownian and Néel processes, we clarified how the magnetization mechanism is affected by viscosity. When the excitation field varies much slower than the Brownian relaxation time, magnetization can be described by the Langevin function. On the other hand, for the case when the excitation field varies much faster than the Brownian relaxation time, but much slower than the Néel relaxation time, the easy axes of the magnetic nanoparticles (MNPs) turn to some extent toward the direction of the excitation field in an equilibrium state. This alignment of the easy axes of MNPs caused by the AC field becomes more significant with the increase of the AC field strength. Consequently, the magnetization is different from the Langevin function even though Néel relaxation time is faster than time period of the external frequency. It is necessary to consider these results when we use harmonic signals from a magnetic fluid in a high-viscosity medium. - Highlights: • We explore the effect of viscosity on harmonic signals from a magnetic fluid. • We clarify how the magnetization mechanism is affected by the viscosity of the fluid. • The magnetization in a high-viscosity medium is different from a Langevin function. • We empirically express the alignment of easy axes of the MNPs caused by an AC field.

  19. Molecular clutch drives cell response to surface viscosity. (United States)

    Bennett, Mark; Cantini, Marco; Reboud, Julien; Cooper, Jonathan M; Roca-Cusachs, Pere; Salmeron-Sanchez, Manuel


    Cell response to matrix rigidity has been explained by the mechanical properties of the actin-talin-integrin-fibronectin clutch. Here the molecular clutch model is extended to account for cell interactions with purely viscous surfaces (i.e., without an elastic component). Supported lipid bilayers present an idealized and controllable system through which to study this concept. Using lipids of different diffusion coefficients, the mobility (i.e., surface viscosity) of the presented ligands (in this case RGD) was altered by an order of magnitude. Cell size and cytoskeletal organization were proportional to viscosity. Furthermore, there was a higher number of focal adhesions and a higher phosphorylation of FAK on less-mobile (more-viscous) surfaces. Actin retrograde flow, an indicator of the force exerted on surfaces, was also seen to be faster on more mobile surfaces. This has consequential effects on downstream molecules; the mechanosensitive YAP protein localized to the nucleus more on less-mobile (more-viscous) surfaces and differentiation of myoblast cells was enhanced on higher viscosity. This behavior was explained within the framework of the molecular clutch model, with lower viscosity leading to a low force loading rate, preventing the exposure of mechanosensitive proteins, and with a higher viscosity causing a higher force loading rate exposing these sites, activating downstream pathways. Consequently, the understanding of how viscosity (regardless of matrix stiffness) influences cell response adds a further tool to engineer materials that control cell behavior. Copyright © 2018 the Author(s). Published by PNAS.

  20. Bulk viscosity of accretion disks around non rotating black holes (United States)

    Moeen Moghaddas, M.


    In this paper, we study the Keplerian, relativistic accretion disks around the non rotating black holes with the bulk viscosity. Many of authors studied the relativistic accretion disks around the black holes, but they ignored the bulk viscosity. We introduce a simple method to calculate the bulk in these disks. We use the simple form for the radial component of the four velocity in the Schwarzschild metric, then the other components of the four velocity and the components of the shear and the bulk tensor are calculated. Also all components of the bulk viscosity, the shear viscosity and stress tensor are calculated. It is seen that some components of the bulk tensor are comparable with the shear tensor. We calculate some of the thermodynamic quantities of the relativistic disks. Comparison of thermodynamic quantities shows that in some states influences of the bulk viscosity are important, especially in the inner radiuses. All calculations are done analytically and we do not use the boundary conditions. Finally, we find that in the relativistic disks around the black holes, the bulk viscosity is non-negligible in all the states.

  1. Measuring Lipid Membrane Viscosity Using Rotational and Translational Tracer Diffusion (United States)

    Hormel, Tristan; Kurihara, Sarah; Reyer, Matthew; Parthasarathy, Raghuveer


    The two-dimensional fluidity of lipid membranes enables the motion of membrane-bound macromolecules and is therefore crucial to biological function. However, current methods of measuring membrane viscosity rely on particular membrane lipid compositions or geometries, making the comparison of different measurements difficult. We address this with a new technique for measuring lipid membrane viscosity, in which determination of both the rotational and translational diffusion coefficients of tracer particles enables quantification of viscosity as well as the effective size of the tracers. This technique is general, and can be applied to different model membrane systems to determine the effects of membrane composition and protein modulation. We present measurements of lipid membrane viscosity for two different lipids with phosphatidylcholine headgroups, finding a surprisingly wide distribution of effective tracer sizes, due presumably to a large variety of couplings to the membrane. We also compare the effective viscosity of two different structures - black lipid membranes and membrane multilayers - as well as changes in viscosity induced by peripheral protein binding.

  2. Relaxation-based viscosity mapping for magnetic particle imaging. (United States)

    Utkur, M; Muslu, Y; Saritas, E U


    Magnetic particle imaging (MPI) has been shown to provide remarkable contrast for imaging applications such as angiography, stem cell tracking, and cancer imaging. Recently, there is growing interest in the functional imaging capabilities of MPI, where 'color MPI' techniques have explored separating different nanoparticles, which could potentially be used to distinguish nanoparticles in different states or environments. Viscosity mapping is a promising functional imaging application for MPI, as increased viscosity levels in vivo have been associated with numerous diseases such as hypertension, atherosclerosis, and cancer. In this work, we propose a viscosity mapping technique for MPI through the estimation of the relaxation time constant of the nanoparticles. Importantly, the proposed time constant estimation scheme does not require any prior information regarding the nanoparticles. We validate this method with extensive experiments in an in-house magnetic particle spectroscopy (MPS) setup at four different frequencies (between 250 Hz and 10.8 kHz) and at three different field strengths (between 5 mT and 15 mT) for viscosities ranging between 0.89 mPa · s-15.33 mPa · s. Our results demonstrate the viscosity mapping ability of MPI in the biologically relevant viscosity range.

  3. Saliva viscosity as a potential risk factor for oral malodor. (United States)

    Ueno, Masayuki; Takeuchi, Susumu; Takehara, Sachiko; Kawaguchi, Yoko


    The objective of this study was to assess whether saliva viscosity, measured by a viscometer, was a predictor of oral malodor. The subjects were 617 patients who visited an oral malodor clinic. The organoleptic test (OT) was used for diagnosis of oral malodor. An oral examination assessed the numbers of teeth present and decayed teeth as well as the presence or absence of dentures. Further, periodontal pocket depths (PD), gingival bleeding, dental plaque and tongue coating were investigated. Unstimulated saliva were collected for 5 min. Saliva viscosity was measured with a viscometer. Logistic regression analysis with oral malodor status by OT as a dependent variable was performed. Possible confounders including age, gender, number of teeth present, number of decayed teeth, number of teeth with PD ≥ 4 mm, number of teeth with bleeding on probing, presence or absence of dentures, plaque index, area of tongue coating, saliva flow rate, saliva pH and saliva viscosity were used as independent variables. Saliva viscosity (p = 0.047) along with the number of teeth with PD ≥4 mm (p = 0.001), plaque index (p = 0.037) and area of tongue coating (p viscosity (OR = 1.10) were more likely to have oral malodor compared to those with lower values. The results suggested that high saliva viscosity could be a potential risk factor for oral malodor.

  4. Impact of aggregate formation on the viscosity of protein solutions. (United States)

    Nicoud, Lucrèce; Lattuada, Marco; Yates, Andrew; Morbidelli, Massimo


    Gaining knowledge on the stability and viscosity of concentrated therapeutic protein solutions is of great relevance to the pharmaceutical industry. In this work, we borrow key concepts from colloid science to rationalize the impact of aggregate formation on the changes in viscosity of a concentrated monoclonal antibody solution. In particular, we monitor the kinetics of aggregate growth under thermal stress by static and dynamic light scattering, and we follow the rise in solution viscosity by measuring the diffusion coefficient of tracer nanoparticles with dynamic light scattering. Moreover, we characterize aggregate morphology in the frame of the fractal geometry. We show that the curves of the increase in viscosity with time monitored at three different protein concentrations collapse on one single master curve when the reaction profiles are normalized based on an effective volume fraction occupied by the aggregates, which depends on the aggregate size, concentration and morphology. Importantly, we find that the viscosity of an aggregate sample is lower than the viscosity of a monomeric sample of a similar occupied volume fraction due to the polydispersity of the aggregate distribution.

  5. The Weighted Super Bergman Kernels Over the Supermatrix Spaces (United States)

    Feng, Zhiming


    The purpose of this paper is threefold. Firstly, using Howe duality for , we obtain integral formulas of the super Schur functions with respect to the super standard Gaussian distributions. Secondly, we give explicit expressions of the super Szegö kernels and the weighted super Bergman kernels for the Cartan superdomains of type I. Thirdly, combining these results, we obtain duality relations of integrals over the unitary groups and the Cartan superdomains, and the marginal distributions of the weighted measure.

  6. Entropy-viscosity based LES of turbulent flow in a flexible pipe (United States)

    Wang, Zhicheng; Xie, Fangfang; Triantafyllou, Michael; Constantinides, Yiannis; Karniadakis, George


    We present large-eddy simulations (LES) of turbulent flow in a flexible pipe conveying incompressible fluid. We are interested in quantifying the flow-structure interaction in terms of mean quantities and their variances. For the LES, we employ an Entropy Viscosity Method (EVM), implemented in a spectral element code. In previous work, we investigated laminar flow and studied the complex interaction between structural and internal flow dynamics and obtained a phase diagram of the transition between states as function of three non-dimensional quantities: the fluid-tension parameter, the dimensionless fluid velocity, and the Reynolds number. Here we extend our studies in the turbulence regime, Re from 5,000 to 50,000. The motion of the flexible pipe affects greatly the turbulence statistics of the pipe flow, with substantial differences for free (self-sustained) vibrations and prescribed (forced) vibrations.

  7. Viscosity Relaxation in Molten HgZnTe (United States)

    Baird, James K.


    Because of its narrow electronic band-gap, HgZnTe solid solutions have been proposed as effective detectors for infrared radiation. To produce the best single crystals of these materials for this application, knowledge of the phase diagram that governs the freezing of the liquid is essential. Besides the phase diagram, however, some information concerning the thermophysical properties of the melt, such as viscosity, density, specific heat, and enthalpy of mixing, can also be useful. Of these thermophysical properties, the viscosity is perhaps of the most interest scientifically. Measurements using the oscillating cup method have shown that the isothermal melt requires tens of hours of equilibration time before a steady value of the viscosity can be achieved. Over this equilibration time, which depends upon temperature, the viscosity can increase by as much as a factor of two before reaching a steady state. We suggest that this relaxation phenomenon may be due to a slight polymerization of Te atoms in the melt. To account for the time dependence of the viscosity in the HgZnTe melt, we propose that the liquid acts as a solvent that favors the formation of Te atom chains. We suggest that as the melt is cooled from a high temperature to the temperature for measurement of the viscosity, a free radical polymerization of Te atoms begins. To estimate this average molecular weight, we use a simple free radical polymerization mechanism, including a depolymerization step, to calculate the time dependence to the concentration of each Te polymer molecular weight fraction. From these molecular weight fractions, we compute the weight average molecular weight of the distribution. Using the semi-empirical relation between average molecular weight and viscosity, we obtain a formula for the time dependence of the viscosity of the melt. Upon examining this formula, we find that the viscosity achieves a steady value when a balance is achieved between the rate of formation of the chains

  8. The structure of the super-W∞(λ) algebra

    NARCIS (Netherlands)

    Bergshoeff, E.; Wit, B. de; Vasiliev, M.


    We give a comprehensive treatment of the super-W∞(λ) algebra, an extension of the super-Virasoro algebra that contains generators of spin s ≥ ½. The parameter λ defines the embedding of the Virasoro subalgebra. We describe how to obtain the super-W∞(λ) algebra from the associative algebra of

  9. Conduit speed limit promotes formation of explosive `super slugs' (United States)

    Llewellin, E. W.; Burton, M. R.; Mader, H. M.; Polacci, M.


    Strombolian activity - characterized by discrete, impulsive explosions - is common at basaltic volcanoes. The explosions are caused by the arrival, at the volcanic vent, of over-pressured `slugs' of magmatic gas, which have ascended the volcanic conduit. We present data from large-scale analogue experiments which reveal a previously-undescribed process which promotes the formation of large, highly over-pressured `super slugs'. We propose that these large slugs may drive the most violent Strombolian eruptions. Experiments were performed at the Large Analogue Volcano Apparatus at Durham University, UK, which comprises a 13m tall, 24cm diameter transparent conduit, surmounting a reservoir of analogue magma held at constant pressure. We simulate a vesiculation event deep in the sub-volcanic plumbing system by fluxing gas into the reservoir. Magma analogues with a range of viscosities are used, giving slug Reynolds numbers in the range 16 to 140,000. At moderate-to-high Reynolds number, we find that the gas rapidly self-organizes to form a conduit-filling lead slug; this slug ascends the column slowly, at a velocity limited by the flux of the falling film of liquid around it. Trailing bubbles, which ascend through the wake of the lead slug, rise much more rapidly. As they catch and coalesce with the lead slug, it grows and becomes increasingly over-pressured. This mechanism causes large slugs to form rapidly and we propose that it underpins the formation of the very large slugs that are responsible for the most explosive strombolian eruptions.

  10. Comparison the clinical outcomes and complications of high-viscosity versus low-viscosity in osteoporotic vertebral compression fractures. (United States)

    Guo, Zhao; Wang, Wei; Gao, Wen-Shan; Gao, Fei; Wang, Hui; Ding, Wen-Yuan


    To compare the clinical outcomes and complications of high viscosity and low viscosity bone cement percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCF).From September 2009 to September 2015, 100 patients with OVCF were randomly divided into 2 groups: group H, using high viscosity cement (n = 50) or group L, using low viscosity cement (n = 50). The clinical outcomes were assessed by the visual analog scale (VAS), Oswestry Disability Index (ODI), kyphosis Cobb angle, vertebral height, and complications.Significant improvements in the VAS, ODI, kyphosis Cobb angle, and vertebral height were noted in both groups, and the VAS score in the H group showed greater benefit than in the L group. Cement leakage was observed less in group H. Postoperative assessment using computed tomography identified cement leakage in 27 of 98 (27.6%) vertebrae in group H and in 63 of 86 (73.3%) vertebrae in group L (P = .025).Compared with PVP using low viscosity bone cement, PVP using high viscosity bone cement can provide the same clinical outcomes with fewer complications and is recommended for routine clinical use.

  11. A comparison of high viscosity bone cement and low viscosity bone cement vertebroplasty for severe osteoporotic vertebral compression fractures. (United States)

    Zhang, Liang; Wang, Jingcheng; Feng, Xinmin; Tao, Yuping; Yang, Jiandong; Wang, Yongxiang; Zhang, Shengfei; Cai, Jun; Huang, Jijun


    To compare the clinical outcome and complications of high viscosity and low viscosity poly-methyl methacrylate bone cement PVP for severe OVCFs. From December 2010 to December 2012, 32 patients with severe OVCFs were randomly assigned to either group H using high viscosity cement (n=14) or group L using low viscosity cement (n=18). The clinical outcomes were assessed by the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Short Form-36 General Health Survey (SF-36), kyphosis Cobb's angle, vertebral height, and complications. Significant improvement in the VAS, ODI, SF-36 scores, kyphosis Cobb's angle, and vertebral height were noted in both the groups, and there were no significant differences between the two groups. Cement leakage was seen less in group H. Postoperative assessment using computed tomography identified cement leakage in 5 of 17 (29.4%) vertebrae in group H and in 15 of 22 (68.2%) vertebrae in group L (P=0.025). The PVP using high viscosity bone cement can provide the same clinical outcome and fewer complications compared with PVP using low viscosity bone cement. Copyright © 2014. Published by Elsevier B.V.

  12. Single Image Super Resolution via Sparse Reconstruction

    NARCIS (Netherlands)

    Kruithof, M.C.; Eekeren, A.W.M. van; Dijk, J.; Schutte, K.


    High resolution sensors are required for recognition purposes. Low resolution sensors, however, are still widely used. Software can be used to increase the resolution of such sensors. One way of increasing the resolution of the images produced is using multi-frame super resolution algorithms.

  13. Nanostructured coatings for super hydrophobic textiles

    Indian Academy of Sciences (India)

    However, silica nanoparticles can be suitably functionalized or can be used as a component of nanocom- posite coating to adhere with cotton surface. Amino functiona- lized silica nanoparticles applied on epoxy functionalized cotton fabric shows excellent super-hydrophobicity (∼170. ◦. ). The functionalization of silica and ...

  14. Structural optimization of super-repellent surfaces

    DEFF Research Database (Denmark)

    Cavalli, Andrea; Bøggild, Peter; Okkels, Fridolin


    Micro-patterning is an effective way to achieve surfaces with extreme liquid repellency. This technique does not rely on chemical coatings and is therefore a promising concept for application in food processing and bio-compatibile coatings. This super-repellent behaviour is obtained by suspending...

  15. Super Darboux-Egoroff equations and solutions

    NARCIS (Netherlands)

    Kersten, P.H.M.; Martini, Ruud


    Super Darboux-Egoroff equations are discussed. First of all linearity of the potential $\\varphi$ with respect to odd variables is proved. Solutions of Darboux-Egoroff equations in dimension $(2|2)$ including flatness of the unit vector field are constructed. Moreover solutions of Darboux-Egoroff

  16. Constraining the Composition of Super-Earths (United States)

    Carrera, D.; Ford, E. B.; Wolfgang, A.


    We use computer simulations to model planet formation, including migration, accretion, and atmosphere loss via giant impacts. For each model we predict the mass and density ratios of TTV planets, and compare them to super-Earths in the Kepler field.

  17. Super-thermal light for imaging applications (United States)

    Allevi, Alessia; Cassina, Silvia; Bondani, Maria


    We report on a new classical light source useful for ghost-imaging applications. The light is obtained by frequency doubling a conventional speckle pattern having an overall multi-mode thermal distribution. The frequency-doubled light acquires a super-thermal distribution, which induces higher correlations at a beam splitter and, as a consequence, a higher visibility in ghost-imaging protocols.

  18. Atmospheric neutrino results from Super-Kamiokande

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Takaaki [Kamioka Observatory, Inst. for Cosmic Ray Research, Tokyo Univ., Kamioka, Gifu (Japan)


    Recent results from Super-kamiokande on atmospheric neutrino measurement are presented. The small ({mu}/e){sub data}/({mu}/e){sub MC} was strongly confirmed. In addition, a statistically significant zenith angle dependence of the high-energy {mu}-like events was observed, suggesting {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillations. (author)

  19. Super-flat supercontinuum generation from a Tm-doped fiber amplifier. (United States)

    Tao, Mengmeng; Yu, Ting; Wang, Zhenbao; Chen, Hongwei; Shen, Yanlong; Feng, Guobin; Ye, Xisheng


    Super-flat supercontinua are generated from a double clad Tm-doped fiber amplifier. Two different laser configurations are investigated and compared. In the direct-output configuration, the long-wavelength edge of the supercontinuum spectra is extended to beyond 2.65 μm with a 10 dB bandwidth of 740 nm. In the passive pigtail configuration, the generated supercontinuum features excellent flatness with an intensity difference smaller than 1 dB in the wide central spectral range from 1.98 μm to 2.41 μm.


    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chiang, Eugene, E-mail:, E-mail: [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720-3411 (United States)


    The riddle posed by super-Earths (1–4R{sub ⊕}, 2–20M{sub ⊕}) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ∼0.1–1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4–10R{sub ⊕}, 2–6M{sub ⊕}). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ∼1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.

  1. Effect of Fluid Viscosity on Noise of Bileaflet Prosthetic Heart Valve

    Directory of Open Access Journals (Sweden)

    Vladimir A. Voskoboinick


    Full Text Available Background. Numerical simulation and experimental research have been used as powerful tools to understand and predict the behavior and mechanics of the operation of natural heart valves and their prostheses in natural and patho­logical conditions. Such studies help to evaluate the effectiveness of the valves, their design and the results of surgical procedures, to diagnose healthy and impaired function of the heart valves. There is an actual problem in creating more reliable methods and tools for the operation diagnostics of mechanical heart valves. Objective. The aim of the research is to investigate the effect of fluid viscosity on the hydroacoustic characteristics of jets that flow from a semi-closed and open mechanical bileaflet heart valve. To study the possibility of using hydro­acoustic measuring instruments as diagnostic equipment for determining the working conditions of the bileaflet pro­sthe­tic heart valve. Methods. The experimental research was carried out by means of hydroacoustic measurements of the hydrodynamic noise in the near wake of the side and central jets of the glycerin solution and the pure water flow downstream of the prosthetic bileaflet heart valve. Results. The effect of fluid viscosity on the hydroacoustic characteristics of the jets that flow from a semi-closed and open mechanical bileaflet heart valve has been experimentally determined. Integral and spectral characteristics of the hydrodynamic noise of jets of the glycerin solution and the pure water flow downstream of the bileaflet mitral heart valve for different fluid rate were detected. Conclusions. In the stream conditions of pure water, the integral characteristics of the pressure field are lower than in stream conditions of the aqueous glycerin solution. As the glycerin concentration in the solution increases, increase average pressures and especially RMS pressure fluctuations. The spectral levels of the hydrodynamic noise in the near wake of the side

  2. Proceedings of SuperB Workshop VI: New Physics at the Super Flavor Factory

    CERN Document Server

    Hitlin, D.G.; Asner, D.M.; Hurth, T.; McElrath, B.; Shindou, T.; Ronga, F.; Rama, M.; Tosi, S.; Simi, G.; Robertson, S.; Paradisi, P.; Bigi, I.; Stocchi, A.; Viaud, B.; Domingo, F.; Kou, E.; Morandin, M.; Batignani, G.; Cervelli, A.; Forti, F.; Neri, N.; Walsh, J.; Giorgi, M.; Isidori, G.; Lusiani, A.; Bevan, A.; Faccini, R.; Renga, F.; Polosa, A.; Silvestrini, L.; Virto, J.; Ciuchini, M.; Heinemeyer, S.; Carpinelli, M.; Gambino, P.; Azzolini, V.; Bernabeu, J.; Botella, F.; Branco, G.C.; Lopez March, N.; Martinez Vidal, F.; Oyanguren, A.; Pich, A.; Sanchis Lozano, M.A.; Vidal, J.; Vives, O.; Banerjee, Swagato; Roney, J.M.; Gershon, T.


    The sixth SuperB Workshop was convened in response to questions posed by the INFN Review Committee, evaluating the SuperB project at the request of INFN. The working groups addressed the capability of a high-luminosity flavor factory that can gather a data sample of 50 to 75 /ab in five years to elucidate New Physics phenomena unearthed at the LHC. This report summarizes the results of the Workshop.

  3. SuperB A High-Luminosity Asymmetric $e^+ e^-$ Super Flavour Factory : Conceptual Design Report

    CERN Document Server

    Bona, M.; Grauges Pous, E.; Colangelo, P.; De Fazio, F.; Palano, A.; Manghisoni, M.; Re, V.; Traversi, G.; Eigen, G.; Venturini, M.; Soni, N.; Bruschi, M.; De Castro, S.; Faccioli, P.; Gabrieli, A.; Giacobbe, B.; Semprini Cesare, N.; Spighi, R.; Villa, M.; Zoccoli, A.; Hearty, C.; McKenna, J.; Soni, A.; Khan, A.; Barniakov, A.Y.; Barniakov, M.Y.; Blinov, V.E.; Druzhinin, V.P.; Golubev, V.B.; Kononov, S.A.; Koop, I.A.; Kravchenko, E.A.; Levichev, E.B.; Nikitin, S.A.; Onuchin, A.P.; Piminov, P.A.; Serednyakov, S.I.; Shatilov, D.N.; Skovpen, Y.I.; Solodov, E.A.; Cheng, C.H.; Echenard, B.; Fang, F.; Hitlin, D.J.; Porter, F.C.; Asner, D.M.; Pham, T.N.; Fleischer, R.; Giudice, G.F.; Hurth, T.; Mangano, M.; Mancinelli, G.; Meadows, B.T.; Schwartz, A.J.; Sokoloff, M.D.; Soffer, A.; Beard, C.D.; Haas, T.; Mankel, R.; Hiller, G.; Ball, P.; Pappagallo, M.; Pennington, M.R.; Gradl, W.; Playfer, S.; Abada, A.; Becirevic, D.; Descotes-Genon, S.; Pene, O.; Andreotti, D.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabresi, R.; Cecchi, A.; Cibinetto, G.; Franchini, P.; Luppi, E.; Negrini, M.; Petrella, A.; Piemontese, L.; Prencipe, E.; Santoro, V.; Stancari, G.; Anulli, F.; Baldini-Ferroli, R.; Biagini, M.E.; Boscolo, M.; Calcaterra, A.; Drago, A.; Finocchiaro, G.; Guiducci, S.; Isidori, G.; Pacetti, S.; Patteri, P.; Peruzzi, I.M.; Piccolo, M.; Preger, M.A.; Raimondi, P.; Rama, M.; Vaccarezza, C.; Zallo, A.; Zobov, M.; De Sangro, R.; Buzzo, A.; Lo Vetere, M.; Macri, M.; Monge, M.R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Matias, J.; Panduro Vazquez, W.; Borzumati, F.; Eyges, V.; Prell, S.A.; Pedlar, T.K.; Korpar, S.; Pestonik, R.; Staric, M.; Neubert, M.; Denig, A.G.; Nierste, U.; Agoh, T.; Ohmi, K.; Ohnishi, Y.; Fry, J.R.; Touramanis, C.; Wolski, A.; Golob, B.; Krizan, P.; Flaecher, H.; Bevan, A.J.; Di Lodovico, F.; George, K.A.; Barlow, R.; Lafferty, G.; Jawahery, A.; Roberts, D.A.; Simi, G.; Patel, P.M.; Robertson, S.H.; Lazzaro, A.; Palombo, F.; Kaidalov, A.; Buras, A.J.; Tarantino, C.; Buchalla, G.; Sanda, A.I.; D'Ambrosio, G.; Ricciardi, G.; Bigi, I.; Jessop, C.P.; Losecco, J.M.; Honscheid, K.; Arnaud, N.; Chehab, R.; Fedala, Y.; Polci, F.; Roudeau, P.; Sordini, V.; Soskov, V.; Stocchi, A.; Variola, A.; Vivoli, A.; Wormser, G.; Zomer, F.; Bertolin, A.; Brugnera, R.; Gagliardi, N.; Gaz, A.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Bonneaud, G.R.; Lombardo, V.; Calderini, G.; Ratti, L.; Speziali, V.; Biasini, M.; Covarelli, R.; Manoni, E.; Servoli, L.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Dell'Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.; Lusiani, A.; Marchiori, G.; Massa, M.; Mazur, M.A.; Morsani, F.; Neri, N.; Paoloni, E.; Raffaelli, F.; Rizzo, G.; Walsh, J.; Braun, V.; Lenz, A.; Adams, G.S.; Danko, I.Z.; Baracchini, E.; Bellini, F.; Cavoto, G.; D'Orazio, A.; Del Re, D.; Di Marco, E.; Faccini, R.; Ferrarotto, F.; Gaspero, Mario; Jackson, P.; Martinelli, G.; Mazzoni, M.A.; Morganti, Silvio; Piredda, G.; Renga, F.; Silvestrini, L.; Voena, C.; Catani, L.; Di Ciaccio, A.; Messi, R.; Santovetti, E.; Satta, A.; Ciuchini, M.; Lubicz, V.; Wilson, F.F.; Godang, R.; Chen, X.; Liu, H.; Park, W.; Purohit, M.; Trivedi, A.; White, R.M.; Wilson, J.R.; Allen, M.T.; Aston, D.; Bartoldus, R.; Brodsky, S.J.; Cai, Y.; Coleman, J.; Convery, M.R.; DeBarger, S.; Dingfelder, J.C.; Dubois-Felsmann, G.P.; Ecklund, S.; Fisher, A.S.; Haller, G.; Heifets, S.A.; Kaminski, J.; Kelsey, M.H.; Kocian, M.L.; Leith, D.W.G.S.; Li, N.; Luitz, S.; Luth, V.; MacFarlane, D.; Messner, R.; Muller, D.R.; Nosochkov, Y.; Novokhatski, A.; Pivi, M.; Ratcliff, B.N.; Roodman, A.; Schwiening, J.; Seeman, J.; Snyder, A.; Sullivan, M.; Va'Vra, J.; Wienands, U.; Wisniewski, W.; Stoeck, H.; Cheng, H.Y.; Li, H.N.; Keum, Y.Y.; Gronau, M.; Grossman, Y.; Bianchi, F.; Gamba, D.; Gambino, P.; Marchetto, F.; Menichetti, Ezio A.; Mussa, R.; Pelliccioni, M.; Dalla Betta, G.F.; Bomben, M.; Bosisio, L.; Cartaro, C.; Lanceri, L.; Vitale, L.; Azzolini, V.; Bernabeu, J.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A.; Paradisi, P.; Pich, A.; Sanchis-Lozano, M.A.; Kowalewski, Robert V.; Roney, J.M.; Back, J.J.; Gershon, T.J.; Harrison, P.F.; Latham, T.E.; Mohanty, G.B.; Petrov, A.A.; Pierini, M.; INFN


    The physics objectives of SuperB, an asymmetric electron-positron collider with a luminosity above 10^36/cm^2/s are described, together with the conceptual design of a novel low emittance design that achieves this performance with wallplug power comparable to that of the current B Factories, and an upgraded detector capable of doing the physics in the SuperB environment.

  4. A technique for accurately determining the cusp-region polar cap boundary using SuperDARN HF radar measurements

    Directory of Open Access Journals (Sweden)

    G. Chisham

    Full Text Available Accurately measuring the location and motion of the polar cap boundary (PCB in the high-latitude ionosphere can be crucial for studies concerned with the dynamics of the polar cap, e.g. the measurement of reconnection rates. The Doppler spectral width characteristics of backscatter received by the SuperDARN HF radars have been previously used for locating and tracking the PCB in the cusp region. The boundary is generally observed in meridional beams of the SuperDARN radars and appears as a distinct change between low spectral width values observed equatorward of the cusp region, and high, but variable spectral width values observed within the cusp region. To identify the spectral width boundary (SWB between these two regions, a simple algorithm employing a spectral width threshold has often been applied to the data. However, there is not, as yet, a standard algorithm, or spectral width threshold, which is universally applied. Nor has there been any rigorous assessment of the accuracy of this method of boundary determination. This study applies a series of threshold algorithms to a simulated cusp-region spectral width data set, to assess the accuracy of different algorithms. This shows that simple threshold algorithms correctly identify the boundary location in, at the most, 50% of the cases and that the average boundary error is at least ~ 1–2 range gates (~ 1° latitude. It transpires that spatial and temporal smoothing of the spectral width data (e.g. by median filtering, before application of a threshold algorithm can increase the boundary determination accuracy to over 95% and the average boundary error to much less than a range gate. However, this is sometimes at the cost of temporal resolution in the motion of the boundary location. The algorithms are also applied to a year’s worth of spectral width data from the cusp ionosphere, measured by the Halley SuperDARN radar in Antarctica. This analysis highlights the increased accuracy of

  5. A technique for accurately determining the cusp-region polar cap boundary using SuperDARN HF radar measurements

    Directory of Open Access Journals (Sweden)

    G. Chisham


    Full Text Available Accurately measuring the location and motion of the polar cap boundary (PCB in the high-latitude ionosphere can be crucial for studies concerned with the dynamics of the polar cap, e.g. the measurement of reconnection rates. The Doppler spectral width characteristics of backscatter received by the SuperDARN HF radars have been previously used for locating and tracking the PCB in the cusp region. The boundary is generally observed in meridional beams of the SuperDARN radars and appears as a distinct change between low spectral width values observed equatorward of the cusp region, and high, but variable spectral width values observed within the cusp region. To identify the spectral width boundary (SWB between these two regions, a simple algorithm employing a spectral width threshold has often been applied to the data. However, there is not, as yet, a standard algorithm, or spectral width threshold, which is universally applied. Nor has there been any rigorous assessment of the accuracy of this method of boundary determination. This study applies a series of threshold algorithms to a simulated cusp-region spectral width data set, to assess the accuracy of different algorithms. This shows that simple threshold algorithms correctly identify the boundary location in, at the most, 50% of the cases and that the average boundary error is at least ~ 1–2 range gates (~ 1° latitude. It transpires that spatial and temporal smoothing of the spectral width data (e.g. by median filtering, before application of a threshold algorithm can increase the boundary determination accuracy to over 95% and the average boundary error to much less than a range gate. However, this is sometimes at the cost of temporal resolution in the motion of the boundary location. The algorithms are also applied to a year’s worth of spectral width data from the cusp ionosphere, measured by the Halley SuperDARN radar in Antarctica. This analysis highlights the increased accuracy of

  6. The influence of tongue strength on oral viscosity discrimination acuity. (United States)

    Steele, Catriona M


    The ability to generate tongue pressures is widely considered to be critical for liquid bolus propulsion in swallowing. It has been proposed that the application of tongue pressure may also serve the function of collecting sensory information regarding bolus viscosity (resistance to flow). In this study, we explored the impact of age-related reductions in tongue strength on oral viscosity discrimination acuity. The experiment employed a triangle test discrimination protocol with an array of xanthan-gum thickened liquids in the mildly to moderately thick consistency range. A sample of 346 healthy volunteers was recruited, with age ranging from 12 to 86 (164 men, 182 women). On average, participants were able to detect a 0.29-fold increase in xanthan-gum concentration, corresponding to a 0.5-fold increase in viscosity at 50/s. Despite having significantly reduced tongue strength on maximum isometric tongue-palate pressure tasks, and regardless of sex, older participants in this study showed no reductions in viscosity discrimination acuity. In this article, the relationship between tongue strength and the ability to discriminate small differences in liquid viscosity during oral processing is explored. Given that tongue strength declines with age in healthy adults and is also reduced in individuals with dysphagia, it is interesting to determine whether reduced tongue strength might contribute to difficulties in evaluating liquid viscosity during the oral stage of swallowing. Using an array of mildly to moderately thick xanthan-gum thickened liquids, this experiment failed to find any evidence that reductions in tongue strength influence oral viscosity discrimination acuity. © 2017 Wiley Periodicals, Inc.

  7. Demonstrating the Importance of Bubbles and Viscosity on Volcanic Eruptions (United States)

    Namiki, A.


    The behavior of bubbles (exsolved volatile from magma) and viscosity of magma are important parameters that influence volcanic eruptions. Exsolved volatiles increase the volume of magma and reduce its density so that magma has sufficient volume and buoyancy force to erupt. Volatiles exsolve through nucleation and growth by diffusion and bubbles can expand as pressure is reduced. The time scale of diffusion depends on the viscosity of surrounding magma, and the expansion time scale of a bubble is also depends on the viscosity of magma. These control the time scale for volume change. If bubbles segregate from magma and collapse, the magma might not able to expand sufficiently to erupt violently. Whether a bubble can segregate from the liquid part of magma is also depends on viscosity of magma. In this poster, I introduce a straightforward demonstration to show the importance of bubbles and viscosity of magma on volcanic eruptions. To make bubbles, I use baking soda (NaHCO3) and citric acid. Reaction between them generates carbon dioxide (CO2) to make bubbles. I make citric acid solution gel by using agar at the bottom of a transparent glass and pour baking soda disolved corn syrup on top of the agar. This situation is a model of basally heated magma chamber. When water disolved magma (baking soda disolved corn syrup) receives sufficient heat (citric acid) bubbles are generated. I can change viscosity of corn syrup by varying the concentration of water. This demonstration shows how viscosity controls the time scale of volume change of bubbly magma and the distribution of bubbles in the fluid. In addition it helps to understand the important physical processes in volcanic eruption: bubble nucleation, diffusion grows, expansion, and bubble driving convection. I will perform a live demonstration at the site of the poster.

  8. Intrinsic viscosity of polymers and biopolymers measured by microchip. (United States)

    Lee, Jinkee; Tripathi, Anubhav


    Intrinsic viscosity provides insight to molecular structure and interactions in solution. A new microchip method is described for fast and accurate measurements of viscosity and intrinsic viscosity of polymer and biopolymer solutions. Polymer samples are diluted with solvent in the microfluidic chip by imposing pressure gradients across the channel network. The concentration and flow dilutions of the polymer sample are calculated from the fluorescent signals recorded over a range of dilutions. The viscosities at various polymer dilutions are evaluated using mass and momentum balances in the pressure-driven microchannel flow. The technique is particularly important to many chemical, biological, and medical applications where sample is available in very small quantities. The intrinsic viscosity experiments were performed for three classes of polymer solutions: (a) poly(ethylene glycol), polymers with linear hydrocarbon chains; (b) bovine serum albumin, biopolymer chains with hydrophobic and hydrophilic amino acids, and (c) DNA fragments, biological macromolecules with double-stranded polymeric chains. The measured values of intrinsic viscosity agree remarkably well with the available data obtained using different methods. The data exhibit power law behavior for molecular weight as described by the Mark-Houwink-Sakurada equation. Experiments were performed to understand the effect of solvent quality and salt concentration on molecular conformations and the intrinsic viscosity of the polymers. This method offers a new way to study the conformational changes in proteins and DNA solutions in various buffer conditions such as pH, ionic strength, and surfactants. The effects of shear rate in the microchannel and mixing time on the accuracy and limitation of the measurement method are discussed.

  9. The 2015 super-resolution microscopy roadmap (United States)

    Hell, Stefan W.; Sahl, Steffen J.; Bates, Mark; Zhuang, Xiaowei; Heintzmann, Rainer; Booth, Martin J.; Bewersdorf, Joerg; Shtengel, Gleb; Hess, Harald; Tinnefeld, Philip; Honigmann, Alf; Jakobs, Stefan; Testa, Ilaria; Cognet, Laurent; Lounis, Brahim; Ewers, Helge; Davis, Simon J.; Eggeling, Christian; Klenerman, David; Willig, Katrin I.; Vicidomini, Giuseppe; Castello, Marco; Diaspro, Alberto; Cordes, Thorben


    Far-field optical microscopy using focused light is an important tool in a number of scientific disciplines including chemical, (bio)physical and biomedical research, particularly with respect to the study of living cells and organisms. Unfortunately, the applicability of the optical microscope is limited, since the diffraction of light imposes limitations on the spatial resolution of the image. Consequently the details of, for example, cellular protein distributions, can be visualized only to a certain extent. Fortunately, recent years have witnessed the development of ‘super-resolution’ far-field optical microscopy (nanoscopy) techniques such as stimulated emission depletion (STED), ground state depletion (GSD), reversible saturated optical (fluorescence) transitions (RESOLFT), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), structured illumination microscopy (SIM) or saturated structured illumination microscopy (SSIM), all in one way or another addressing the problem of the limited spatial resolution of far-field optical microscopy. While SIM achieves a two-fold improvement in spatial resolution compared to conventional optical microscopy, STED, RESOLFT, PALM/STORM, or SSIM have all gone beyond, pushing the limits of optical image resolution to the nanometer scale. Consequently, all super-resolution techniques open new avenues of biomedical research. Because the field is so young, the potential capabilities of different super-resolution microscopy approaches have yet to be fully explored, and uncertainties remain when considering the best choice of methodology. Thus, even for experts, the road to the future is sometimes shrouded in mist. The super-resolution optical microscopy roadmap of Journal of Physics D: Applied Physics addresses this need for clarity. It provides guidance to the outstanding questions through a collection of short review articles from experts in the field, giving a thorough

  10. Determination of Viscosity Versus Pressure by Means of a Clearance Seal

    DEFF Research Database (Denmark)

    Christiansen, Peter; Schmidt Hansen, Niels; Lund, Martin Thomas Overdahl


    This paper describes the construction and testing of a simple, experimental tool setup that enables determination of the pressure–viscosity relationship for high viscosity oils. Comparing the determined pressure–viscosity relationship with a reference rheometer measuring the viscosity at ambient ...

  11. Vowel Inherent Spectral Change

    CERN Document Server

    Assmann, Peter


    It has been traditional in phonetic research to characterize monophthongs using a set of static formant frequencies, i.e., formant frequencies taken from a single time-point in the vowel or averaged over the time-course of the vowel. However, over the last twenty years a growing body of research has demonstrated that, at least for a number of dialects of North American English, vowels which are traditionally described as monophthongs often have substantial spectral change. Vowel Inherent Spectral Change has been observed in speakers’ productions, and has also been found to have a substantial effect on listeners’ perception. In terms of acoustics, the traditional categorical distinction between monophthongs and diphthongs can be replaced by a gradient description of dynamic spectral patterns. This book includes chapters addressing various aspects of vowel inherent spectral change (VISC), including theoretical and experimental studies of the perceptually relevant aspects of VISC, the relationship between ar...

  12. Spectral transmittance reference standards

    Energy Technology Data Exchange (ETDEWEB)

    Kruglyakova, M.A.; Belyaeva, O.N.; Nikitin, M.V.


    This paper presents spectral transmittance reference standards for UV and IR spectrophotometers, developed, studied, and certified by a precision spectrophotometry laboratory (the RSP Complex). 8 refs., 3 figs., 3 tabs.

  13. Regolith on Super Fast Rotators (United States)

    Sanchez Lana, Diego Paul; Scheeres, Daniel J.


    these results we derive a scaling law that can be used to determine whether observed small asteroids could retain surface regolith of a given size. The implications of this for the interpretation of spectral observations of small asteroids are discussed.

  14. Shear viscosity of shocked metals at mega-bar pressures (United States)

    Liu, Fu-Sheng


    Viscosity of metals at high pressures and temperatures has been one of the most concerned problems in weapon physics and geophysics, e.g., the shear viscosity coefficients of substances in earth's mantle and earth's core at mega-bar pressures are needed for understanding the core mantle convection in deep earth. But the experimental data is very scarce because the conventional measurement methods can hardly be applied to such compression conditions [1]. In this talk, the principle of small-disturbance perturbation method [2] is re-investigated based on both the analytic solution and the numerical solution of the two-dimentional shock flow of sinusoidal distubance on front. In numerical solution, the real viscosity, which governs the flow behind the shock front and the perturbation damping feature, and the artificial viscosity, whick controls the numerical oscillation, separately treated. The relation between the viscosity of flow and the damping features of perturbation amplitude is quantitatively established for the loading situations of Sakharov's [3] and a flyer-impact situation with a finite disturbance. The later is the theoretical basis to develop a new experimental method, called the flyer-impact small-disturbance method [4]. In the flyer-impact small-disturbance method, the two-stage light-gas gun is used to launch a metal flyer. When the flyer directly impacts on the wedge-shaped sample with a sinusoidal surface, a two-dimensional shock flow of sinusoidal distubance on its front is generated. The amplitude of disturbance and its dependance with propagation distance is measured by use of an electric pin-array probe or a fibre-array probe. Correspondingly, the solution of the flow is given by numerically solving the hydrodynamic equations by the finite difference technique to find out the quantative correlations among the amplitude decay, the initial distribution of flow, the amplitude of initial disturbance, the shear viscosity of the flow, and the material

  15. The influence of magnetic fields on crude oils viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Jose L.; Bombard, Antonio J. F. [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Instituto de Ciencias Exatas. Lab. de Reologia


    The crystallization of paraffin causes serious problems in the process of transportation of petroleum. This phenomenon increases the crude oil viscosity and implies an organic resin accumulation on pipeline wall, resulting in a reduced flux area or totally blocked pipes. One of the most challenging tasks for pipeline maintenance is solving this problem at low cost. Therefore, a method that inhibits the crystallization of paraffin and reduces the viscosity of crude oil could have many useful applications within the petroleum industry. Recent studies showed that magnetic fields reduce the Wax Appearance Temperature (WAT) and the viscosity of paraffin-based crude oil. For better understanding of this discovery, a series of tests was performed. This paper will show the influence of a DC magnetic field on rheological proprieties of three crude oils with different paraffin concentrations: a crude oil sample with 11 % p/p of paraffin concentration (sample 1); a crude oil sample with 6 % p/p of paraffin concentration (sample 2); a mixture of paraffin plus light crude oil with a total of 11 % p/p of paraffin concentration. These samples were placed in an electromagnet that generates a magnetic field of 1.3 Tesla. The samples' temperatures were conditioned around their Wax Appearance Temperature (WAT), and they were exposed to the field. As the viscosity of crude oil is very sensitive to the changes in temperature, it was ensured that the temperature has remained constant throughout the process. The sample 1 revealed a considerable reduction of viscosity: its original viscosity was 66 cP before magnetic field exposure, after that its viscosity was reduced to 39 cP. The other samples showed the same viscosity, before and after the magnetic field exposure. Since the samples 1 and 3 have the same paraffin concentrations, the viscosity reduction is not due only to the presence of paraffin; there must be other factors responsible for the interaction of sample 1 with the

  16. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Directory of Open Access Journals (Sweden)

    Fangfang LIU


    Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

  17. Thermophotovoltaic Spectral Control

    Energy Technology Data Exchange (ETDEWEB)

    DM DePoy; PM Fourspring; PF Baldasaro; JF Beausang; EJ Brown; MW Dashiel; KD Rahner; TD Rahmlow; JE Lazo-Wasem; EJ Gratrix; B Wemsman


    Spectral control is a key technology for thermophotovoltaic (TPV) direct energy conversion systems because only a fraction (typically less than 25%) of the incident thermal radiation has energy exceeding the diode bandgap energy, E{sub g}, and can thus be converted to electricity. The goal for TPV spectral control in most applications is twofold: (1) Maximize TPV efficiency by minimizing transfer of low energy, below bandgap photons from the radiator to the TPV diode. (2) Maximize TPV surface power density by maximizing transfer of high energy, above bandgap photons from the radiator to the TPV diode. TPV spectral control options include: front surface filters (e.g. interference filters, plasma filters, interference/plasma tandem filters, and frequency selective surfaces), back surface reflectors, and wavelength selective radiators. System analysis shows that spectral performance dominates diode performance in any practical TPV system, and that low bandgap diodes enable both higher efficiency and power density when spectral control limitations are considered. Lockheed Martin has focused its efforts on front surface tandem filters which have achieved spectral efficiencies of {approx}83% for E{sub g} = 0.52 eV and {approx}76% for E{sub g} = 0.60 eV for a 950 C radiator temperature.

  18. Spectrally selective glazings

    Energy Technology Data Exchange (ETDEWEB)



    Spectrally selective glazing is window glass that permits some portions of the solar spectrum to enter a building while blocking others. This high-performance glazing admits as much daylight as possible while preventing transmission of as much solar heat as possible. By controlling solar heat gains in summer, preventing loss of interior heat in winter, and allowing occupants to reduce electric lighting use by making maximum use of daylight, spectrally selective glazing significantly reduces building energy consumption and peak demand. Because new spectrally selective glazings can have a virtually clear appearance, they admit more daylight and permit much brighter, more open views to the outside while still providing the solar control of the dark, reflective energy-efficient glass of the past. This Federal Technology Alert provides detailed information and procedures for Federal energy managers to consider spectrally selective glazings. The principle of spectrally selective glazings is explained. Benefits related to energy efficiency and other architectural criteria are delineated. Guidelines are provided for appropriate application of spectrally selective glazing, and step-by-step instructions are given for estimating energy savings. Case studies are also presented to illustrate actual costs and energy savings. Current manufacturers, technology users, and references for further reading are included for users who have questions not fully addressed here.

  19. Investigation of viscosity of whole hydrolyze sweetened condensed milk

    Directory of Open Access Journals (Sweden)

    O. Kalinina


    Full Text Available Introduction. Рaper is aimed at developing of low-lactose (hydrolyzed sweetened condensed milk products technology for lactose intolerant people and for the whole population. Materials and methods: Rheological characteristics were determined on a Reotest device by the 2 nd method of viscometry Results and discussion. Reasonability of ß-galactosidase use for milk lactose hydrolyze during the production of canned products with sugar was proved in the previous works. This technology gives possibility to increase the quality of condensed canned foods, to reduce sugar concentration till 50 %, to increase dietary properties. Due to the reducing of saccharose mass part till 22 and 31 % the products had a liquid consistency that’s why was a necessity to increase the viscosity properties of condensed products. One of method to increase the product viscosity is inoculation of stabilization systems. Reasonability of the usage of stabilization system Bivicioc 1L was proved. The researches of viscosity determination in whole hydrolyzed sweetened condensed milk were shown in the work. Relations of viscosity of whole hydrolyzed condensed milk to the deformation rate were presented. Conclusions Viscosity indices of experimental samples in the fresh produced products and during storage are determined and justified.

  20. Biopolymer solution viscosity stabilization-polymer degradation and antioxidant use

    Energy Technology Data Exchange (ETDEWEB)

    Wellington, S.L.


    Dilute solutions of polymers used to provide mobility control for EOR often lose viscosity, especially at higher temperatures. This loss of viscosity with time brings into question the feasibility of using polymers as mobility control agents. A literature study of the many possible reaction mechanisms indicated that oxidation/reduction (redox) reactions involving free radicals probably caused polymer degradation and concomitant viscosity loss. A preliminary search for antioxidants known to retard free-radical reactions located several types and positive synergistic formulations that significantly retarded biopolymer solution viscosity loss during accelerated tests at high temperature. The most effective type formulation found contained (1) a radical transfer agent; (2) a sacrificial, easily oxidizable alcohol; (3) a compatible oxygen scavenger; and (4) sufficient brine concentration. Samples prepared with this technology have not lost viscosity after 1-year storage at 207/sup 0/F (97/sup 0/C). A high-surface-area effect (so-called ''wall effect''), known to retard radical propagation, was also found to operate in the presence of sandpacks; this should be beneficial in porous media. The variables and beneficial antioxidant formulations identified in this study allow tentative conclusions and recommendations regarding biopolymer mixing and handling procedures prior to injection.

  1. Universality of the shear viscosity of alkali metals (United States)

    Meyer, N.; Xu, H.; Wax, J.-F.


    The universality of the shear viscosity of alkali metals is studied up to high pressure. Equilibrium molecular dynamics simulations are used to calculate the stress autocorrelation function, which allows us to obtain the value of shear viscosity using the Green-Kubo formula. Atomic interactions are computed from Fiolhais pseudopotential and are validated by comparison between pair distribution functions and mean-squared displacements obtained from classical and ab initio molecular dynamics simulations. The description of the interactions is accurate at least up to 12 GPa, 9.4 GPa, 6.6 GPa, and 3 GPa for Na, K, Rb, and Cs, respectively, and to a lesser extent up to 4.8 GPa for Li. A good agreement between simulation and experimental viscosity results along the liquid-gas coexistence curve is found. The viscosity appears to be a universal property over a wide range of the liquid phase of the phase diagram, between 0.85 and 1.5 times the ambient melting density and up to seven times the ambient melting temperature. Scaling laws are proposed following relations formulated in [Meyer, Xu, and Wax, Phys. Rev. B 93, 214203 (2016), 10.1103/PhysRevB.93.214203] so that it is possible to predict the viscosity value of any alkali metal with an accuracy better than 10% over the corresponding density and temperature range.

  2. The effect of gasses on the viscosity of dimethyl ether

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, Jørgen


    media, but their effect on DME viscosity is unknown. Argon (Ar), nitrogen (NA carbon dioxide (CO2), hydrogen (H-2) and propane (C3H8) have been investigated at pressure levels of 12-15 bar. A Cannon-Manning semi-micro capillary glass viscometer, size 25, enclosed in a cylindrical pressure container......, of glass, submerged completely in a constant temperature bath, has been used. A distinct reduction of efflux times was found only for the gas, CO2. The reduction in efflux time was about 9%. The kinematic viscosity of pure DME was determined to be: 0.188 +/- 0.001 cSt, 25 degrees C. A previously reported...... viscosity of pure DME has been corrected for the surface tension effect. Viscosity determination was initially based on a direct comparison of efflux times of DME with that of distilled water. The calculation gave a revised viscosity of 0.186 +/- 0.002 cSt, 25 degrees C, consistent with the above...

  3. Bulk viscosity, interaction and the viability of phantom solutions

    Energy Technology Data Exchange (ETDEWEB)

    Leyva, Yoelsy; Sepulveda, Mirko [Universidad de Tarapaca, Departamento de Fisica, Facultad de Ciencias, Arica (Chile)


    We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker (FRW) Universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an imperfect fluid having bulk viscosity. We also introduce an interaction term between the dark matter and dark energy components. Considering that the bulk viscosity is proportional to the dark matter energy density and imposing a complete cosmological dynamics, we find bounds on the bulk viscosity in order to reproduce a matter-dominated era (MDE). This constraint is independent of the interaction term. Some late time phantom solutions are mathematically possible. However, the constraint imposed by a MDE restricts the interaction parameter, in the phantom solutions, to a region consistent with a null value, eliminating the possibility of late time stable solutions with w < -1. From the different cases that we study, the only possible scenario, with bulk viscosity and interaction term, belongs to the quintessence region. In the latter case, we find bounds on the interaction parameter compatible with latest observational data. (orig.)

  4. Dark goo: Bulk viscosity as an alternative to dark energy

    CERN Document Server

    Gagnon, Jean-Sebastien


    We present a simple (microscopic) model in which bulk viscosity plays a role in explaining the present acceleration of the universe. The effect of bulk viscosity on the Friedmann equations is to turn the pressure into an "effective" pressure containing the bulk viscosity. For a sufficiently large bulk viscosity, the effective pressure becomes negative and could mimic a dark energy equation of state. Our microscopic model includes self-interacting spin-zero particles (for which the bulk viscosity is known) that are added to the usual energy content of the universe. We study both background equations and linear perturbations in this model. We show that a dark energy behavior is obtained for reasonable values of the two parameters of the model (i.e. the mass and coupling of the spin-zero particles) and that linear perturbations are well-behaved. There is no apparent fine tuning involved. We also discuss the conditions under which hydrodynamics holds, in particular that the spin-zero particles must be in local eq...

  5. Dynamic viscosity study of barley malt and chicory concentrates

    Directory of Open Access Journals (Sweden)

    G. O. Magomedov


    Full Text Available The purpose of research is to find optimal conditions for dispersing and subsequent dehydration of liquid food environments in the nozzle spray drying chamber through the study of dynamic changes in viscosity according to temperature, velocities gradients and dry residue content. The objects of study were roasted chicory and malt barley concentrates with dry residue content of 20, 40, 60 and 80%. Research of dynamic viscosity were carried out at the measuring complex based on the rotational viscometer Rheotest II, analog-to-digital converter, module Laurent and a personal computer with a unique software that allows to record in real time (not only on a tape recorder, but also in the form of graphic files the behavior of the viscosity characteristics of concentrates. Registration of changes of dynamic viscosity was carried out at a shear rate gradient from 1,0 с -1 to 27,0 с -1 and the products temperature thermostating : 35, 55, 75˚ C. The research results are presented in the form of graphic dependences of effective viscosity on shear rate and flow curves (dependencies of shear stresses on the velocity gradient, which defined flow regimes, the optimal modes of dispersion concentrates into spray dryer chambers in obtaining of powdered semi-finished products and instanting were found: dry residue content - 40 %, concentrate temperature - 75 ˚C, velocity gradient in the air channel of the nozzle at least 20 c-1

  6. Association between blood viscosity and common carotid artery elasticity. (United States)

    Tripolino, Cesare; Irace, Concetta; Carallo, Claudio; De Franceschi, Maria Serena; Scavelli, Faustina; Della Valle, Elisabetta; Gnasso, Agostino


    Elastic properties of the vessel wall are associated with atherosclerosis and major cardiovascular events. Several physiological and pathological conditions can affect arterial elasticity, but few studies have considered the role of hemorheological parameters. The present study aimed to investigate the relationship between hemorheological parameters and vascular stiffness in the carotid artery district. One hundred and two individuals were enrolled. Blood and plasma viscosity were measured by a cone-plate viscometer (Wells-Brookfield DV-III, Stoughton, U.S.A.). Echo-Doppler evaluation of carotid arteries was performed in order to calculate elastic indexes (strain, β-stiffness index and distensibility). The association between hemorheological parameters and carotid elasticity indexes was assessed by simple and multiple regression analyses. In simple correlation analysis, only blood viscosity was directly associated with β-stiffness index (r = 0.20, p = 0.05) and inversely with strain (r =-0.26, p = 0.01) and distensibility (r =-0.34, p = 0.001). After adjusting for cardiovascular risk factors, blood viscosity, but not plasma viscosity or hematocrit, was independently associated carotid arterial measures, together with age, obesity, hypertension, and dyslipidemia. The results of the present study demonstrate a strong association between blood viscosity and common carotid elasticity indexes.

  7. Effect of viscosity on droplet-droplet collisional interaction (United States)

    Finotello, Giulia; Padding, Johan T.; Deen, Niels G.; Jongsma, Alfred; Innings, Fredrik; Kuipers, J. A. M.


    A complete knowledge of the effect of droplet viscosity on droplet-droplet collision outcomes is essential for industrial processes such as spray drying. When droplets with dispersed solids are dried, the apparent viscosity of the dispersed phase increases by many orders of magnitude, which drastically changes the outcome of a droplet-droplet collision. However, the effect of viscosity on the droplet collision regime boundaries demarcating coalescence and reflexive and stretching separation is still not entirely understood and a general model for collision outcome boundaries is not available. In this work, the effect of viscosity on the droplet-droplet collision outcome is studied using direct numerical simulations employing the volume of fluid method. The role of viscous energy dissipation is analysed in collisions of droplets with different sizes and different physical properties. From the simulations results, a general phenomenological model depending on the capillary number (Ca, accounting for viscosity), the impact parameter (B), the Weber number (We), and the size ratio (Δ) is proposed.

  8. Viscosity of diluted suspensions of vegetal particles in water

    Directory of Open Access Journals (Sweden)

    Szydłowska Adriana


    Full Text Available Viscosity and rheological behaviour of sewage as well as sludge are essential while designing apparatuses and operations employed in the sewage treatment process and its processing. With reference to these substances, the bio-suspensions samples of three size fractions ((i 150÷212 μm, (ii 106÷150 μm and (iii below106 μm of dry grass in water with solid volume fraction 8%, 10% and 11% were prepared. After twenty four hours prior to their preparation time, the suspension samples underwent rheometeric measurements with the use of a rotational rheometer with coaxial cylinders. On the basis of the obtained results, flow curves were plotted and described with both the power model and Herschel-Bulkley model. Moreover, the viscosity of the studied substances was determined that allowed to conclude that the studied bio-suspensions display features of viscoelastic fluids. The experimentally established viscosity was compared to the calculated one according to Manley and Manson equation, recommended in the literature. It occurred that the measured viscosity values substantially exceed the calculation viscosity values, even by 105 times. The observations suggest that it stems from water imbibition of fibrous vegetal particles, which causes their swelling and decreases the amount of liquid phase in the suspension.

  9. Viscosity changes in hyaluronic acid: Irradiation and rheological studies

    Energy Technology Data Exchange (ETDEWEB)

    Daar, Eman [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail:; King, L.; Nisbet, A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Thorpe, R.B. [Fluids and Systems Centre, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Bradley, D.A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)


    Hyaluronic acid (HA) is a significant component of the extracellular matrix (ECM), particular interest being shown herein in synovial fluid. The present study aims to investigate the degrading effects of X-ray radiation on HA at radiotherapy doses. Measurements of viscosity and shear stresses on HA solutions have been made at different shear rates using various types of viscometer for different concentrations in the range 0.01-1% w/v of HA. The HA has been subjected to doses of 6 MV photon radiation ranging from 0 to 20 Gy, the major emphasis being on doses below 5 Gy. It is found that there is a dose-dependent relationship between viscosity and shear rate, viscosity reducing with radiation dose, this being related to polymer scissions via the action of radiation-induced free radicals. The dependency appears to become weaker at higher concentrations, possibly due to the contribution to viscosity from polymer entanglement becoming dominant over that from mean molecular weight. Present results, for HA solutions in the concentration range 0.01% to 1% w/v, show reduced viscosity with dose over the range 0-4 Gy, the latter covering the dose regime of interest in fractionated radiotherapy. The work also shows agreement with previous Raman microspectrometry findings by others, the possible bond alterations being defined by comparison with available published data.

  10. Detection of Liposome Membrane Viscosity Perturbations with Ratiometric Molecular Rotors (United States)

    Nipper, Matthew E.; Dakanali, Marianna; Theodorakis, Emmanuel


    Molecular rotors are a form of fluorescent intramolecular charge-transfer complexes that can undergo intramolecular twisting motion upon photoexcitation. Twisted-state formation leads to non-radiative relaxation that competes with fluorescence emission. In bulk solutions, these molecules exhibit a viscosity-dependent quantum yield. On the molecular scale, the fluorescence emission is a function of the local free volume, which in turn is related to the local microviscosity. Membrane viscosity, and the inverse; fluidity, are characteristic terms used to describe the ease of movement withing the membrane. Often, changes in membrane viscosity govern intracellular processes and are indicative of a disease state. Molecular rotors have been used to investigate viscosity changes in liposomes and cells, but accuracy is affected by local concentration gradients and sample optical properties. We have developed self-calibrating ratiometric molecular rotors to overcome this challenge and integrated the new molecules into a DLPC liposome model exposed to the membrane-fluidizing agent propanol. We show that the ratiometric emission intensity linearly decreases with the pentanol exposure and that the ratiometric intensity is widely independent of the total liposome concentration. Conversely, dye concentration inside liposomes influences the sensitivity of the system. We suggest that the new self-calibrating dyes can be used for real-time viscosity sensing in liposome systems with the advantages of lifetime measurements, but with low-cost steady-state instrumentation. PMID:21354253

  11. Probing large viscosities in glass-formers with nonequilibrium simulations (United States)

    Jadhao, Vikram; Robbins, Mark O.


    For decades, scientists have debated whether supercooled liquids stop flowing below a glass transition temperature Tg0 or whether motion continues to slow gradually down to zero temperature. Answering this question is challenging because human time scales set a limit on the largest measurable viscosity, and available data are equally well fit to models with opposite conclusions. Here, we use short simulations to determine the nonequilibrium shear response of a typical glass-former, squalane. Fits of the data to an Eyring model allow us to extrapolate predictions for the equilibrium Newtonian viscosity ηN over a range of pressures and temperatures that change ηN by 25 orders of magnitude. The results agree with the unusually large set of equilibrium and nonequilibrium experiments on squalane and extend them to higher ηN. Studies at different pressures and temperatures are inconsistent with a diverging viscosity at finite temperature. At all pressures, the predicted viscosity becomes Arrhenius with a single temperature-independent activation barrier at low temperatures and high viscosities (ηN>103 Pa ṡs). Possible experimental tests of our results are outlined.

  12. Sensing Super-Position: Human Sensing Beyond the Visual Spectrum (United States)

    Maluf, David A.; Schipper, John F.


    The coming decade of fast, cheap and miniaturized electronics and sensory devices opens new pathways for the development of sophisticated equipment to overcome limitations of the human senses. This paper addresses the technical feasibility of augmenting human vision through Sensing Super-position by mixing natural Human sensing. The current implementation of the device translates visual and other passive or active sensory instruments into sounds, which become relevant when the visual resolution is insufficient for very difficult and particular sensing tasks. A successful Sensing Super-position meets many human and pilot vehicle system requirements. The system can be further developed into cheap, portable, and low power taking into account the limited capabilities of the human user as well as the typical characteristics of his dynamic environment. The system operates in real time, giving the desired information for the particular augmented sensing tasks. The Sensing Super-position device increases the image resolution perception and is obtained via an auditory representation as well as the visual representation. Auditory mapping is performed to distribute an image in time. The three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. This paper details the approach of developing Sensing Super-position systems as a way to augment the human vision system by exploiting the capabilities of Lie human hearing system as an additional neural input. The human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns. The known capabilities of the human hearing system to learn and understand complicated auditory patterns provided the basic motivation for developing an image-to-sound mapping system. The

  13. Experimental viscosity measurements of biodiesels at high pressure

    Directory of Open Access Journals (Sweden)

    Schaschke C.J.


    Full Text Available The viscosity of biodiesels of soybean and rapeseed biodiesels blended with mineral diesel fuel were measured at pressures of up to 200 MPa. Using a falling sinker-type viscometer reproducible viscosity data were obtained based on the time taken for a sinker to descend a fixed distance down an enclosed tube under the influence of gravity. Measurements were taken using pressures which correspond to those of interest in automotive common rail diesel engines, and at temperatures of between 25ºC and 80ºC. In all cases, the viscosity of the biodiesel blends were found to increase exponentially for which the blends were noted as being more viscous than pure mineral fuels. A pressure-freezing effect was not observed for the blends.

  14. In situ viscosity measurements of albite melt under high pressure

    CERN Document Server

    Funakoshi, K I; Terasaki, H


    The viscosities of albite (NaAlSi sub 3 O sub 8) melt under high pressures have been measured using an x-ray radiography falling sphere method with synchrotron radiation. This method has enabled us to determine the precise sinking velocity directly. Recent experiments of albite melt showed the presence of a viscosity minimum around 5 GPa (Poe et al 1997 Science 276 1245, Mori et al 2000 Earth Planet. Sci. Lett. 175 87). We present the results for albite melt up to 5.2 GPa at 1600 and 1700 deg. C. The viscosity minimum is clearly observed to be around 4.5 GPa, and it might be explained not by the change of the compression mechanism in albite melt but by change of the phase itself.

  15. Measurement of Viscosity of Hydrocarbon Liquids Using a Microviscometer

    DEFF Research Database (Denmark)

    Dandekar, Abhijit; Andersen, Simon Ivar; Stenby, Erling Halfdan


    The viscosity of normal alkanes, their mixtures, and true boiling point (TBP) fractions (C (sub 6) -C (sub 19)) of four North Sea petroleum reservoir fluids have been measured by use of an automatic rolling ball mixroviscometer at 20°C. The equipment is specially suited for samples of limited...... amount as only 120 to 2500 micro l. is required depending on the viscosity range. The densities of the fluids were also determined. The accuracy of these measurements is ascertained and compared with literature data on n-alkane mixtures. The data reported for reservoir fluids includes molecular weights...... as well as density. Finally, generalized viscosity correlations for the C (sub 6) to C (sub 19) fractions are discussed....

  16. Effect of viscosity on appetite and gastro-intestinal hormones

    DEFF Research Database (Denmark)

    Zijlstra, Nicolien; Mars, Monica; de Wijk, René A


    In previous studies we showed that higher viscosity resulted in lower ad libitum intake and that eating rate is an important factor. In this study we aimed to explore the effect of viscosity on the gastro-intestinal hormones ghrelin, CCK-8 and GLP-1. Thirty-two subjects (22+/-2 y, BMI 21.9+/-2.2 kg...... than the liquid. There was a significant product effect for fullness (p 0.03), desire to eat (p 0.04), appetite something sweet (p 0.002) and prospective consumption (p 0.0009). We observed no clear effect of viscosity on gastro-intestinal hormones. Only for desacyl ghrelin there was a significant...

  17. Viscosity Measurement via Drop Coalescence: A Space Station Experiment (United States)

    Antar, Basil; Ethridge, Edwin C.


    The concept of using low gravity experimental data together with CFD simulations for measuring the viscosity of highly viscous liquids was recently validated on onboard the International Space Station (ISS). A series of microgravity tests were conducted for this purpose on the ISS in July, 2004 and in May of 2005. In these experiments two liquid drops were brought manually together until they touched and were allowed to coalesce under the action of the capillary force alone. The coalescence process was recorded photographically from which the contact radius speed of the merging drops was measured. The liquid viscosity was determined by fitting the measured data with accurate numerical simulation of the coalescence process. Several liquids were tested and for each liquid several drop diameters were employed. Experimental and numerical results will be presented in which the viscosity of several highly viscous liquids were determined using this technique.

  18. On the Role of Viscosity in the Eyring Equation. (United States)

    Kistemaker, Jos C M; Lubbe, Anouk S; Bloemsma, Erik A; Feringa, Ben L


    Transition-state theory allows for the characterization of kinetic processes in terms of enthalpy and entropy of activation by using the Eyring equation. However, for reactions in solution, it fails to take the change of viscosity of solvents with temperature into account. A second-generation unidirectional rotary molecular motor was used as a probe to study the effects of temperature-dependent viscosity changes upon unimolecular thermal isomerization processes. By combining the free-volume model with transition-state theory, a modified version of the Eyring equation was derived, in which the rate is expressed in terms of both temperature and viscosity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Temperature Dependence of the Viscosity of Isotropic Liquids (United States)

    Jadzyn, J.; Czechowski, G.; Lech, T.


    Temperature dependence of the shear viscosity measured for isotropic liquids belonging to the three homologous series: 4-(trans-4'-n-alkylcyclohexyl) isothiocyanatobenzenes (Cn H2n+1 CyHx Ph NCS; nCHBT, n=0-12), n-alkylcyanobiphenyls (CnH2n+1 Ph Ph CN; nCB, n=2-12) and 1,n-alkanediols (HO(CH2)nOH; 1,nAD, n=2-10) were analysed with the use of Arrhenius equation and its two modifications: Vogel--Fulcher and proposed in this paper. The extrapolation of the isothermal viscosity of 1,n-alkanediols (n=2-10) to n=1 leads to an interesting conclusion concerning the expected viscosity of methanediol, HOCH2OH, the compound strongly unstable in a pure state.

  20. Diffusivities and Viscosities of Poly(ethylene oxide) Oligomers †

    KAUST Repository

    Hong, Bingbing


    Diffusivities and viscosities of poly(ethylene oxide) (PEO) oligomer melts with 1 to 12 repeat units have been obtained from equilibrium molecular dynamics simulations using the TraPPE-UA force field. The simulations generated diffusion coefficients with high accuracy for all of the molar masses studied, but the statistical uncertainties in the viscosity calculations were significantly larger for longer chains. There is good agreement of the calculated viscosities and densities with available experimental data, and thus, the simulations can be used to bridge gaps in the data and for extrapolations with respect to chain length, temperature, and pressure. We explored the convergence characteristics of the Green-Kubo formulas for different chain lengths and propose minimal production times required for convergence of the transport properties. The chain-length dependence of the transport properties suggests that neither Rouse nor reptation models are applicable in the short-chain regime investigated. © 2010 American Chemical Society.

  1. The viscosity window of the silicate glass foam production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng


    The production of silicate glass foam allows diverse resources and waste materials to be used in the production. Testing of such large palette of materials complicates and prolongs the optimisation process. Therefore, it is crucial to find a universal criterion for foaming silicate glass melts...... which can offer a practical starting point for the optimisation procedure. The melt viscosity might be the most important parameter for controlling the foaming process and the glass foam density. In this work, we attempt to define a viscosity range in which foaming of different glasses results...... in a maximum of foam expansion. The expansion maximum is obtained for different glasses (labware, E-glass, CRT panel, soda-lime-silica) by foaming with CaCO3 at isokom temperature and from literature data. In general, the viscosity window was found to be within 104–106 Pa s when foaming with MnO2 or metal...

  2. Bulk viscosity of low-temperature strongly interacting matter

    Energy Technology Data Exchange (ETDEWEB)

    Dobado, Antonio [Departamento de Fisica Teorica I, Universidad Complutense de Madrid, 28040 Madrid (Spain); Llanes-Estrada, Felipe J., E-mail: [Departamento de Fisica Teorica I, Universidad Complutense de Madrid, 28040 Madrid (Spain); Torres-Rincon, Juan M. [Departamento de Fisica Teorica I, Universidad Complutense de Madrid, 28040 Madrid (Spain)


    We study the bulk viscosity of a pion gas in unitarized Chiral Perturbation Theory at low and moderate temperatures, below any phase transition to a quark-gluon plasma phase. We argue that inelastic processes are irrelevant and exponentially suppressed at low temperatures. Since the system falls out of chemical equilibrium upon expansion, a pion chemical potential must be introduced, so we extend the existing theories that include it. We control the zero modes of the collision operator and Landau's conditions of fit when solving the Boltzmann equation with the elastic collision kernel. The dependence of the bulk viscosity with temperature is reminiscent of the findings of Fernandez-Fraile and Gomez Nicola (2009) , while the numerical value is closer to that of Davesne (1996) . In the zero-temperature limit we correctly recover the vanishing viscosity associated to a non-relativistic monoatomic gas.

  3. Mapping microbubble viscosity using fluorescence lifetime imaging of molecular rotors (United States)

    Hosny, Neveen A.; Mohamedi, Graciela; Rademeyer, Paul; Owen, Joshua; Wu, Yilei; Tang, Meng-Xing; Eckersley, Robert J.; Stride, Eleanor; Kuimova, Marina K.


    Encapsulated microbubbles are well established as highly effective contrast agents for ultrasound imaging. There remain, however, some significant challenges to fully realize the potential of microbubbles in advanced applications such as perfusion mapping, targeted drug delivery, and gene therapy. A key requirement is accurate characterization of the viscoelastic surface properties of the microbubbles, but methods for independent, nondestructive quantification and mapping of these properties are currently lacking. We present here a strategy for performing these measurements that uses a small fluorophore termed a “molecular rotor” embedded in the microbubble surface, whose fluorescence lifetime is directly related to the viscosity of its surroundings. We apply fluorescence lifetime imaging to show that shell viscosities vary widely across the population of the microbubbles and are influenced by the shell composition and the manufacturing process. We also demonstrate that heterogeneous viscosity distributions exist within individual microbubble shells even with a single surfactant component. PMID:23690599


    Energy Technology Data Exchange (ETDEWEB)

    Krief, M.; Feigel, A.; Gazit, D., E-mail: [The Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)


    A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation–convection interface. STAR Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity.


    Directory of Open Access Journals (Sweden)

    Z.S. Nazirah


    Full Text Available Empty fruit bunches (EFB are one of the solid wastes produced by the palm oil industry, which is increasing rapidly. The aim of this paper is to analyse the viscosity of empty fruit bunch (EFB bio-oil that can be extracted from all solid waste EFB as a sample, and a few processes were executed. The samples underwent two processes, which were pre-treatment and pyrolysis. The pre-treatment involved three processes, namely, cutting, shredding and sieving, which were necessary in order to prepare EFB into a particle size suitable for the reactor. After that, the samples were fed into the feedback reactor as feedstock for the pyrolysis process to produce bio-oil. Once the bio-oil was produced, its viscosity was tested using the Brookfield Viscometer in two conditions: before and after the chemical reaction. The bio-oil was treated by adding 10 ml and 20 ml of acetone respectively through the chemical reaction. The viscosity test was carried out at different temperatures, which were 25°C, 30°C, 35°C, 40°C, 45°C and 50°C respectively. The observed viscosity of the EFB bio-oil varied and was higher as the temperature decreased. In addition, the viscosity of the EFB bio-oil was higher when it reacted chemically with the acetone added. Therefore, the results showed that the chemical reaction with acetone has the potential to increase the viscosity of EFB bio-oil.

  6. A memory-based model for blood viscosity (United States)

    Ionescu, Clara M.


    This paper presents a comparison between existing models for non-Newtonian fluid viscosity as a function of shear rate variations. A novel model is introduced whose parameters are linked to physiological phenomena in the blood. The end use of such models is to predict changes in viscosity to adapt the speed of a nanorobot device for targeted drug delivery purposes. Simulation results show the agreement between the proposed model and available models from literature. A laboratory scale validation of the proposed model for a fluid mimicking non-Newtonian properties has been performed. Conceptual perspectives are also given in this work.

  7. Analytical shear viscosity in hyperscaling violating black brane (United States)

    Kuang, Xiao-Mei; Wu, Jian-Pin


    In this letter, with the use of matching method, we investigate the shear viscosity in a non-relativistic boundary filed theory without hyperscaling symmetry, which is dual to a bulk charged hyperscaling violating black brane. By matching the solutions to the inner region and outer region at the matching region, we analytically obtain that the ratio of shear viscosity and the entropy density is alway 1 / 4 π at zero temperature and finite temperatures. Our results satisfy the Kovtun-Starinets-Son (KSS) bound.

  8. Viscosity-Induced Crossing of the Phantom Barrier

    Directory of Open Access Journals (Sweden)

    Iver Brevik


    Full Text Available We show explicitly, by using astrophysical data plus reasonable assumptions for the bulk viscosity in the cosmic fluid, how the magnitude of this viscosity may be high enough to drive the fluid from its position in the quintessence region at present time t = 0 across the barrier w = −1 into the phantom region in the late universe. The phantom barrier is accordingly not a sharp mathematical divide, but rather a fuzzy concept. We also calculate the limiting forms of various thermodynamical quantities, including the rate of entropy production, for a dark energy fluid near the future Big Rip singularity.

  9. Time Dependent and Steady Uni-axial Elongational Viscosity

    DEFF Research Database (Denmark)

    Nielsen, Jens K.; Rasmussen, Henrik Koblitz; Hassager, Ole


    Here we present measurements of transient and steady uni-axial elongational viscosity, using the Filament Stretching Rheometer1 or FSR1 (see Fig. 1) of the following melts: Four narrow MMD polystyrene (PS) samples with weight-average molar mass Mw in the range of 50k to 390k. Three different bi......-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements....

  10. Viscosities in the Gluon-Plasma within a Quasiparticle Model

    CERN Document Server

    Bluhm, M; Redlich, K


    A phenomenological quasiparticle model, featuring dynamically generated self-energies of excitation modes, successfully describes lattice QCD results relevant for the QCD equation of state and related quantities both at zero and non-zero net baryon density. Here, this model is extended to study bulk and shear viscosities of the gluon-plasma within an effective kinetic theory approach. In this way, the compatibility of the employed quasiparticle ansatz with the apparent low viscosities of the strongly coupled deconfined gluonic medium is shown.

  11. NVP melt/magma viscosity: insight on Mercury lava flows (United States)

    Rossi, Stefano; Morgavi, Daniele; Namur, Olivier; Vetere, Francesco; Perugini, Diego; Mancinelli, Paolo; Pauselli, Cristina


    After more than four years of orbiting Mercury, NASA's MESSENGER spacecraft came to an end in late April 2015. MESSENGER has provided many new and surprising results. This session will again highlight the latest results on Mercury based on MESSENGER observations or updated modelling. The session will further address instrument calibration and science performance both retrospective on MESSENGER and on the ESA/JAXA BepiColombo mission. Papers covering additional themes related to Mercury are also welcomed. Please be aware that this session will be held as a PICO session. This will allow an intensive exchange of expertise and experience between the individual instruments and mission. NVP melt/magma viscosity: insight on Mercury lava flows S. Rossi1, D. Morgavi1, O. Namur2, D. Perugini1, F.Vetere1, P. Mancinelli1 and C. Pauselli1 1 Dipartimento di Fisica e Geologia, Università di Perugia, piazza Università 1, 06123 Perugia, Italy 2 Uni Hannover Institut für Mineralogie, Leibniz Universität Hannover, Callinstraβe 3, 30167 Hannover, Germany In this contribution we report new measurements of viscosity of synthetic komatitic melts, used the behaviour of silicate melts erupted at the surface of Mercury. Composition of Mercurian surface magmas was calculated using the most recent maps produced from MESSENGER XRS data (Weider et al., 2015). We focused on the northern hemisphere (Northern Volcanic Province, NVP, the largest lava flow on Mercury and possibly in the Solar System) for which the spatial resolution of MESSENGER measurements is high and individual maps of Mg/Si, Ca/Si, Al/Si and S/Si were combined. The experimental starting material contains high Na2O content (≈7 wt.%) that strongly influences viscosity. High temperature viscosity measurements were carried out at 1 atm using a concentric cylinder apparatus equipped with an Anton Paar RheolabQC viscometer head at the Department of Physics and Geology (PVRG_lab) at the University of Perugia (Perugia, Italy

  12. Analytical shear viscosity in hyperscaling violating black brane

    Directory of Open Access Journals (Sweden)

    Xiao-Mei Kuang


    Full Text Available In this letter, with the use of matching method, we investigate the shear viscosity in a non-relativistic boundary filed theory without hyperscaling symmetry, which is dual to a bulk charged hyperscaling violating black brane. By matching the solutions to the inner region and outer region at the matching region, we analytically obtain that the ratio of shear viscosity and the entropy density is alway 1/4π at zero temperature and finite temperatures. Our results satisfy the Kovtun–Starinets–Son (KSS bound.

  13. Italian super-eruption larger than thought (United States)

    Schultz, Colin


    Recent research suggested that the super-eruption of the Campi Flegrei caldera volcano in southern Italy about 40,000 years ago may have played a part in wiping out, or forcing the migration of, the Neanderthal and modern human populations in the eastern Mediterranean regions that were covered in ash. Now a new modeling study by Costa et al. suggests that this eruption may have been even larger than previously thought. This Campi Flegrei eruption produced a widespread ash layer known as Campanian Ignimbrite (CI). Using ash thickness measurements collected at 115 sites and a three-dimensional ash dispersal model, the researchers found that the CI super-eruption would have spread 250-300 cubic kilometers of ash across a 3.7-million-square kilometer region—2 to 3 times previous ash volume estimates.

  14. Pulsating stars in SuperWASP

    Directory of Open Access Journals (Sweden)

    Holdsworth Daniel L.


    Full Text Available SuperWASP is one of the largest ground-based surveys for transiting exoplanets. To date, it has observed over 31 million stars. Such an extensive database of time resolved photometry holds the potential for extensive searches of stellar variability, and provide solid candidates for the upcoming TESS mission. Previous work by e.g. [15], [5], [12] has shown that the WASP archive provides a wealth of pulsationally variable stars. In this talk I will provide an overview of the SuperWASP project, present some of the published results from the survey, and some of the on-going work to identify key targets for the TESS mission.

  15. Hierarchical super-resolution-based inpainting. (United States)

    Le Meur, Olivier; Ebdelli, Mounira; Guillemot, Christine


    This paper introduces a novel framework for examplar-based inpainting. It consists in performing first the inpainting on a coarse version of the input image. A hierarchical super-resolution algorithm is then used to recover details on the missing areas. The advantage of this approach is that it is easier to inpaint low-resolution pictures than high-resolution ones. The gain is both in terms of computational complexity and visual quality. However, to be less sensitive to the parameter setting of the inpainting method, the low-resolution input picture is inpainted several times with different configurations. Results are efficiently combined with a loopy belief propagation and details are recovered by a single-image super-resolution algorithm. Experimental results in a context of image editing and texture synthesis demonstrate the effectiveness of the proposed method. Results are compared to five state-of-the-art inpainting methods.

  16. Super-Resolution for Color Imagery (United States)


    University of Maryland, College Park , MD S Susan Young Sensors and Electron Devices Directorate, ARL Approved for public...separately; however, it requires performing the super-resolution computation 3 times. We transform images in the default red, green, blue (RGB) color space...chrominance components based on ARL’s alias-free image upsampling using Fourier-based windowing methods. A reverse transformation is performed on

  17. The SuperNova Early Warning System


    Scholberg, K.


    A core collapse in the Milky Way will produce an enormous burst of neutrinos in detectors world-wide. Such a burst has the potential to provide an early warning of a supernova's appearance. I will describe the nature of the signal, the sensitivity of current detectors, and SNEWS, the SuperNova Early Warning System, a network designed to alert astronomers as soon as possible after the detected neutrino signal.

  18. Storytelling Revealed in Super Bowl 2016 Advertisements


    Rellahan, Celina


    This thesis investigates the use of storytelling in advertising applications and its influence on the instigation of social activity as measured by online views and social activity generated for advertisements broadcast during the 2016 Super Bowl. The thesis aims at identifying those elements of storytelling that are found in these advertisements and relating these characteristics to the success of the promotion in terms of immediate engagement of the viewing audience. The thesis present...

  19. Hadamard model on the super Riemann surface (United States)

    Shuji, Matsumoto; Shozo, Uehara; Yukinori, Yasui


    A supersymmetrically extended version of the Hadamard model is investigated. Classical solutions are given, which imply that the system is chaotic. Quantization is performed in the path integral method. The quantized energy sum rule is shown to be a superanalog of the Selberg trace formula. The Selberg super zeta function is introduced and energy spectra associated with bosonic (fermionic) states are given by order 1 zero-points (poles) of the zeta function.

  20. Super-sensing through industrial process tomography. (United States)

    Soleimani, Manuchehr


    In this introduction article, we present a brief overview of industrial process tomography. This will start by linking between the concept of industrial process tomography and super-sensing. This will follow with a brief introduction to various process tomography systems and in particular electrical tomography methods. This article is part of the themed issue 'Supersensing through industrial process tomography'. © 2016 The Author(s).

  1. SuperB Simulation Production System (United States)

    Tomassetti, L.; Bianchi, F.; Ciaschini, V.; Corvo, M.; Del Prete, D.; Di Simone, A.; Donvito, G.; Fella, A.; Franchini, P.; Giacomini, F.; Gianoli, A.; Longo, S.; Luitz, S.; Luppi, E.; Manzali, M.; Pardi, S.; Paolini, A.; Perez, A.; Rama, M.; Russo, G.; Santeramo, B.; Stroili, R.


    The SuperB asymmetric e+e- collider and detector to be built at the newly founded Nicola Cabibbo Lab will provide a uniquely sensitive probe of New Physics in the flavor sector of the Standard Model. Studying minute effects in the heavy quark and heavy lepton sectors requires a data sample of 75 ab-1 and a peak luminosity of 1036 cm-2 s-1. The SuperB Computing group is working on developing a simulation production framework capable to satisfy the experiment needs. It provides access to distributed resources in order to support both the detector design definition and its performance evaluation studies. During last year the framework has evolved from the point of view of job workflow, Grid services interfaces and technologies adoption. A complete code refactoring and sub-component language porting now permits the framework to sustain distributed production involving resources from two continents and Grid Flavors. In this paper we will report a complete description of the production system status of the art, its evolution and its integration with Grid services; in particular, we will focus on the utilization of new Grid component features as in LB and WMS version 3. Results from the last official SuperB production cycle will be reported.

  2. HD 97658 and its super-Earth

    Directory of Open Access Journals (Sweden)

    Van Grootel V.


    Full Text Available Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition. We present the confirmation, based on Spitzer observations, that the super-Earth HD 97658 b transits its host star. HD 97658 is a low-mass (M* = 0.77 ± 0.05 M⊙ K1 dwarf, as determined from the Hipparcos parallax and stellar evolution modeling. To constrain the planet parameters, we carry out Bayesian global analyses of Keck-HIRES radial velocities, and MOST and Spitzer photometry. HD 97658 b is a massive (MP = 7.55−0.79+0.83 M⊕ and large (RP = 2.247−0.095+0.098 R⊕ at 4.5 μm super-Earth. We investigate the possible internal compositions for HD 97658 b. Our results indicate a large rocky component, by at least 60% by mass, and very little H-He components, at most 2% by mass. We also discuss how future asteroseismic observations can improve the knowledge of the HD 97658 system, in particular by constraining its age.

  3. Super U Technique for Ingrown Nails. (United States)

    Correa, J; Magliano, J; Agorio, C; Bazzano, C


    Ingrown nails are a common problem, seen mostly in young adults. Also known as onychcrypotisis, this condition typically affects the great toenail. Four stages have been defined according to the severity and duration of the condition, and treatment varies from conservative to surgical techniques depending on the stage. We present our experience with this condition, describing the characteristics of our population and surgical treatment, in particular the super U technique. This was a retrospective, descriptive study of patients with ingrown great toenail treated surgically using the super U technique. We also describe postoperative management. Ten patients with a mean age of 35.7 years underwent operation, 9 for unilateral ingrown great toenail and 1 for bilateral disease. Stage II ingrown nail was the most common. Half of the patients had been treated previously using other surgical techniques. The mean time to healing was 6 weeks. The only postoperative complication was infection in 1 patient. Mild to moderate postoperative pain persisted for a week. The majority of patients were satisfied with the cosmetic result. We believe the super U technique is very useful in stage II ingrown nail and in disease that has recurred after previous surgery, and is the treatment of choice in stage III or IV disease in which excessive hypertrophic tissue is found. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. SuperB Technical Design Report

    CERN Document Server

    Baszczyk, M; Kolodziej, J; Kucewicz, W; Sapor, M; Jeremie, A; Pous, E Grauges; Bruno, G E; De Robertis, G; Diacono, D; Donvito, G; Fusco, P; Gargano, F; Giordano, F; Loddo, F; Loparco, F; Maggi, G P; Manzari, V; Mazziotta, M N; Nappi, E; Palano, A; Santeramo, B; Sgura, I; Silvestris, L; Spinoso, V; Eigen, G; Zalieckas, J; Zhuo, Z; Jenkovszky, L; Balbi, G; Boldini, M; Bonacorsi, D; Cafaro, V; D'Antone, I; Dallavalle, G M; Di Sipio, R; Fabbri, F; Fabbri, L; Gabrielli, A; Galli, D; Giacomelli, P; Giordano, V; Giorgi, F M; Grandi, C; Lax, I; Meo, S Lo; Marconi, U; Montanari, A; Pellegrini, G; Piccinini, M; Rovelli, T; Cesari, N Semprini; Torromeo, G; Tosi, N; Travaglini, R; Vagnoni, V M; Valentinetti, S; Villa, M; Zoccoli, A; Caron, J -F; Hearty, C; Lu, P F -T; Mattison, T S; McKenna, J A; So, R Y -C; Barnyakov, M Yu; Blinov, V E; Botov, A A; Druzhinin, V P; Golubev, V B; Kononov, S A; Kravchenko, E A; Levichev, E B; Onuchin, A P; Serednyakov, S I; Shtol, D A; Skovpen, Y I; Solodov, E P; Cardini, A; Carpinelli, M; Chao, D S -T; Cheng, C H; Doll, D A; Echenard, B; Flood, K; Hanson, J; Hitlin, D G; Ongmongkolkul, P; Porter, F C; Zhu, R Y; Randazzo, N; Burelo, E De La Cruz; Zheng, Y; Campos, P; De Silva, M; Kathirgamaraju, A; Meadows, B; Pushpawela, B; Shi, Y; Sokoloff, M; Castro, G Lopez; Ciaschini, V; Franchini, P; Giacomini, F; Paolini, A; Polania, G A Calderon; Laczek, S; Romanowicz, P; Szybinski, B; Czuchry, M; Flis, L; Harezlak, D; Kocot, J; Radecki, M; Sterzel, M; Szepieniec, T; Szymocha, T; Wójcik, P; Andreotti, M; Baldini, W; Calabrese, R; Carassiti, V; Cibinetto, G; Ramusino, A Cotta; Evangelisti, F; Gianoli, A; Luppi, E; Malaguti, R; Manzali, M; Melchiorri, M; Munerato, M; Padoan, C; Santoro, V; Tomassetti, L; Beretta, M M; Biagini, M; Boscolo, M; Capitolo, E; de Sangro, R; Esposito, M; Felici, G; Finocchiaro, G; Gatta, M; Gatti, C; Guiducci, S; Lauciani, S; Patteri, P; Peruzzi, I; Piccolo, M; Raimondi, P; Rama, M; Sanelli, C; Tomassini, S; Fabbricatore, P; Delepine, D; Santos, M A Reyes; Chrzaszcz, M; Grzymkowski, R; Knap, P; Kotula, J; Lesiak, T; Ludwin, J; Michalowski, J; Pawlik, B; Rachwal, B; Stodulski, M; Wiechczynski, J; Witek, M; Zawiejski, L; Zdybal, M; Aushev, V Y; Ustynov, A; Arnaud, N; Bambade, P; Beigbeder, C; Bogard, F; Borsato, M; Breton, D; Brossard, J; Burmistrov, L; Charlet, D; Chaumat, V; Dadoun, O; Berni, M El; Maalmi, J; Puill, V; Rimbault, C; Stocchi, A; Tocut, V; Variola, A; Wallon, S; Wormser, G; Grancagnolo, F; Ben-Haim, E; Sitt, S; Baylac, M; Bourrion, O; Deconto, J -M; Martinez, Y Gomez; Monseu, N; Muraz, J -F; Real, J -S; Vescovi, C; Cenci, R; Jawahery, A; Roberts, D; Twedt, E W; Cheaib, R; Lindemann, D; Nderitu, S; Patel, P; Robertson, S H; Swersky, D; Warburton, A; Flores, E Cuautle; Sanchez, G Toledo; Biassoni, P; Bombelli, L; Citterio, M; Coelli, S; Fiorini, C; Liberali, V; Monti, M; Nasri, B; Neri, N; Palombo, F; Sabatini, F; Stabile, A; Berra, A; Giachero, A; Gotti, C; Lietti, D; Maino, M; Pessina, G; Prest, M; Martin, J -P; Simard, M; Starinski, N; Taras, P; Drutskoy, A; Makarychev, S; Nefediev, A V; Aloisio, A; Cavaliere, S; De Nardo, G; Della Pietra, M; Doria, A; Giordano, R; Ordine, A; Pardi, S; Russo, G; Sciacca, C; Bigi, I I; Jessop, C P; Wang, W; Bellato, M; Benettoni, M; Corvo, M; Crescente, A; Corso, F Dal; Dosselli, U; Fanin, C; Gianelle, A; Longo, S; Michelotto, M; Montecassiano, F; Morandin, M; Pengo, R; Posocco, M; Rotondo, M; Simi, G; Stroili, R; Gaioni, L; Manazza, A; Manghisoni, M; Ratti, L; Re, V; Traversi, G; Zucca, S; Bizzaglia, S; Bizzarri, M; Cecchi, C; Germani, S; Lebeau, M; Lubrano, P; Manoni, E; Papi, A; Rossi, A; Scolieri, G; Batignani, G; Bettarini, S; Casarosa, G; Cervelli, A; Fella, A; Forti, F; Giorgi, M; Lilli, L; Lusiani, A; Oberhof, B; Paladino, A; Pantaleo, F; Paoloni, E; Perez, A L Perez; Rizzo, G; Walsh, J; Téllez, A Fernández; Beck, G; Berman, M; Bevan, A; Gannaway, F; Inguglia, G; Martin, A J; Morris, J; Bocci, V; Capodiferro, M; Chiodi, G; Dafinei, I; Drenska, N V; Faccini, R; Ferroni, F; Gargiulo, C; Gauzzi, P; Luci, C; Lunadei, R; Martellotti, G; Pellegrino, F; Pettinacci, V; Pinci, D; Recchia, L; Ruggeri, D; Zullo, A; Camarri, P; Cardarelli, R; De Santis, C; Di Ciaccio, A; Di Felice, V; Di Palma, F; Di Simone, A; Marcelli, L; Messi, R; Moricciani, D; Sparvoli, R; Tammaro, S; Branchini, P; Budano, A; Bussino, S; Ciuchini, M; Nguyen, F; Passeri, A; Ruggieri, F; Spiriti, E; Wilson, F; Monzon, I Leon; Millan-Almaraz, J R; Podesta-Lerma, P L M; Aston, D; Dey, B; Fisher, A; Jackson, P D; Leith, D W G S; Luitz, S; MacFarlane, D; McCulloch, M; Metcalfe, S; Novokhatski, A; Osier, S; Prepost, R; Ratcliff, B; Seeman, J; Sullivan, M; Va'vra, J; Wienands, U; Wisniewski, W; Altschul, B D; Purohit, M V; Baudot, J; Ripp-Baudot, I; Cirrone, G A P; Cuttone, G; Bezshyyko, O; Dolinska, G; Soffer, A; Bianchi, F; De Mori, F; Filippi, A; Gamba, D; Marcello, S; Bomben, M; Bosisio, L; Cristaudo, P; Lanceri, L; Liberti, B; Rashevskaya, I; Stella, C; Vallazza, E S; Vitale, L; Auriemma, G; Satriano, C; Vidal, F Martinez; de Cos, J Mazorra; Oyanguren, A; Valls, P Ruiz; Beaulieu, A; Dejong, S; Franta, J; Lewczuk, M J; Roney, M; Sobie, R


    In this Technical Design Report (TDR) we describe the SuperB detector that was to be installed on the SuperB e+e- high luminosity collider. The SuperB asymmetric collider, which was to be constructed on the Tor Vergata campus near the INFN Frascati National Laboratory, was designed to operate both at the Upsilon(4S) center-of-mass energy with a luminosity of 10^{36} cm^{-2}s^{-1} and at the tau/charm production threshold with a luminosity of 10^{35} cm^{-2}s^{-1}. This high luminosity, producing a data sample about a factor 100 larger than present B Factories, would allow investigation of new physics effects in rare decays, CP Violation and Lepton Flavour Violation. This document details the detector design presented in the Conceptual Design Report (CDR) in 2007. The R&D and engineering studies performed to arrive at the full detector design are described, and an updated cost estimate is presented. A combination of a more realistic cost estimates and the unavailability of funds due of the global economic ...

  5. SuperB Progress Reports - Physics

    CERN Document Server

    O'Leary, B.; Ramon, M.; Pous, E.; De Fazio, F.; Palano, A.; Eigen, G.; Asgeirsson, D.; Cheng, C.H.; Chivukula, A.; Echenard, B.; Hitlin, D.G.; Porter, F.; Rakitin, A.; Heinemeyer, S.; McElrath, B.; Andreassen, R.; Meadows, B.; Sokoloff, M.; Blanke, M.; Lesiak, T.; Shindou, T.; Ronga, F.; Baldini, W.; Bettoni, D.; Calabrese, R.; Cibinetto, G.; Luppi, E.; Rama, M.; Bossi, F.; Guido, E.; Patrignani, C.; Tosi, S.; Davies, C.; Lunghi, E.; Haisch, U.; Hurth, T.; Westhoff, S.; Crivellin, A.; Hofer, L.; Goto, T.; Brown, David Nathan; Branco, G.C.; Zupan, J.; Herrero, M.; Rodriguez-Sanchez, A.; Simi, G.; Tackmann, F.J.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Lindemann, D.M.; Robertson, S.H.; Duling, B.; Gemmler, K.; Gorbahn, M.; Jager, S.; Paradisi, P.; Straub, D.M.; Bigi, I.; Asner, D.M.; Fast, J.E.; Kouzes, R.T.; Morandin, M.; Rotondo, M.; Ben-Haim, E.; Arnaud, N.; Burmistrov, L.; Kou, E.; Perez, A.; Stocchi, A.; Viaud, B.; Domingo, F.; Piccinini, F.; Manoni, E.; Batignani, G.; Cervelli, A.; Forti, F.; Giorgi, M.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Neri, N.; Walsh, J.; Bevan, A.; Bona, M.; Walker, C.; Weiland, C.; Lenz, A.; Gonzalez-Sprinberg, G.; Faccini, R.; Renga, F.; Polosa, A.; Silvestrini, L.; Virto, J.; Ciuchini, M.; Lubicz, V.; Tarantino, C.; Wilson, F.F.; Carpinelli, M.; Huber, T.; Mannel, T.; Graham, M.; Ratcliff, B.N.; Santoro, V.; Sekula, S.; Shougaev, K.; Soffer, A.; Shimizu, Y.; Gambino, P.; Mussa, R.; Nardecchia, M.; Stal, O.; Bernabeu, J.; Botella, F.; Jung, M.; Lopez March, N.; Martinez Vidal, F.; Oyanguren, A.; Pich, A.; Lozano, M.A.Sanchis; Vidal, J.; Vives, O.; Banerjee, S.; Roney, J.M.; Petrov, A.A.; Flood, K.


    SuperB is a high luminosity e+e- collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measure...

  6. Further results on super graceful labeling of graphs

    Directory of Open Access Journals (Sweden)

    Gee-Choon Lau


    Full Text Available Let G=(V(G,E(G be a simple, finite and undirected graph of order p and size q. A bijection f:V(G∪E(G→{k,k+1,k+2,…,k+p+q−1} such that f(uv=|f(u−f(v| for every edge uv∈E(G is said to be a k-super graceful labeling of G. We say G is k-super graceful if it admits a k-super graceful labeling. For k=1, the function f is called a super graceful labeling and a graph is super graceful if it admits a super graceful labeling. In this paper, we study the super gracefulness of complete graph, the disjoint union of certain star graphs, the complete tripartite graphs K(1,1,n, and certain families of trees. We also present four methods of constructing new super graceful graphs. In particular, all trees of order at most 7 are super graceful. We conjecture that all trees are super graceful.

  7. Near-Infrared Detection of Super-Thin Disks of Massive Spiral Galaxies (United States)

    Schechtman-Rook, Andrew; Bershady, M. A.


    In the Milky Way star formation preferentially occurs close to the galactic midplane, and can be represented by a super-thin disk with an exponential-like radial and vertical profile. Unfortunately, due to dust attenuation, it is not clear if other massive spiral galaxies also possess such disks. Indirect evidence for the presence of such a component comes from the spectral energy distribution of spirals, which contains more far-infrared flux (from dust re-emission) than can be accounted for by an extrapolation of the observed light profile to the midplane. These spectral energy distributions contain no spatial information, however, so the detailed structural parameters of a star-forming disk are not recoverable. We have undertaken a program of high-resolution near-infrared imaging of edge-on spiral galaxies, which, coupled with state-of-the-art radiation transfer models, allow us to strip away the effects of the dust and reveal the intrinsic light distribution all the way down to the midplane. We find that, in addition to thin and thick disks already known from deep optical observations of these galaxies, super-thin disks similar to the Milky Way's are necessary to accurately fit the attenuation-corrected near-infrared light distributions. We acknowledge support for this work from the National Science Foundation (AST-1009491).

  8. Experimental demonstration of outdoor 2.2 Tbps super-channel FSO transmission system

    KAUST Repository

    Esmail, Maged Abdullah


    Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a potential candidate for last mile bottle neck in wireless network and for many other applications. In this paper, we experimentally demonstrate a high speed FSO system using super-channel source and multi-format transmitter. The FSO system was installed outdoor on the building roof over 11.5 m distance and built using off-the-shelf components. We designed a comb source capable of generating multi-subcarriers with flexible spacing. Also we designed a multi-format transmitter capable of generating different complex modulation schemes. For single carrier transmission, we were able to transmit a 23 Gbaud 16-QAM signal over FSO link, achieving 320 Gbps with 6 b/s/Hz spectral efficiency. Then using our super-channel system, 12 equal gain subcarriers are generated and modulated by a DP-16QAM signal with different symbol rates. We achieved maximum symbol rate of 23 Gbaud (i.e. 2.2 Tbps) and spectral efficiency of 7.2 b/s/Hz. © 2016 IEEE.

  9. Nobel Lecture: Single-molecule spectroscopy, imaging, and photocontrol: Foundations for super-resolution microscopy* (United States)

    Moerner, W. E. William E.


    The initial steps toward optical detection and spectroscopy of single molecules in condensed matter arose out of the study of inhomogeneously broadened optical absorption profiles of molecular impurities in solids at low temperatures. Spectral signatures relating to the fluctuations of the number of molecules in resonance led to the attainment of the single-molecule limit in 1989 using frequency-modulation laser spectroscopy. In the early 1990s, many fascinating physical effects were observed for individual molecules, and the imaging of single molecules as well as observations of spectral diffusion, optical switching and the ability to select different single molecules in the same focal volume simply by tuning the pumping laser frequency provided important forerunners of the later super-resolution microscopy with single molecules. In the room-temperature regime, imaging of single copies of the green fluorescent protein also uncovered surprises, especially the blinking and photoinduced recovery of emitters, which stimulated further development of photoswitchable fluorescent protein labels. Because each single fluorophore acts as a light source roughly 1 nm in size, microscopic observation and localization of individual fluorophores is a key ingredient to imaging beyond the optical diffraction limit. Combining this with active control of the number of emitting molecules in the pumped volume led to the super-resolution imaging of Eric Betzig and others, a new frontier for optical microscopy beyond the diffraction limit. The background leading up to these observations is described and selected current developments are summarized.

  10. Parametric Explosion Spectral Model

    Energy Technology Data Exchange (ETDEWEB)

    Ford, S R; Walter, W R


    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.

  11. Photovoltaic spectral responsivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Emery, K.; Dunlavy, D.; Field, H.; Moriarty, T. [National Renewable Energy Lab., Golden, CO (United States)


    This paper discusses the various elemental random and nonrandom error sources in typical spectral responsivity measurement systems. The authors focus specifically on the filter and grating monochrometer-based spectral responsivity measurement systems used by the Photovoltaic (PV) performance characterization team at NREL. A variety of subtle measurement errors can occur that arise from a finite photo-current response time, bandwidth of the monochromatic light, waveform of the monochromatic light, and spatial uniformity of the monochromatic and bias lights; the errors depend on the light source, PV technology, and measurement system. The quantum efficiency can be a function of he voltage bias, light bias level, and, for some structures, the spectral content of the bias light or location on the PV device. This paper compares the advantages and problems associated with semiconductor-detector-based calibrations and pyroelectric-detector-based calibrations. Different current-to-voltage conversion and ac photo-current detection strategies employed at NREL are compared and contrasted.

  12. Quantitatively mapping cellular viscosity with detailed organelle information via a designed PET fluorescent probe. (United States)

    Liu, Tianyu; Liu, Xiaogang; Spring, David R; Qian, Xuhong; Cui, Jingnan; Xu, Zhaochao


    Viscosity is a fundamental physical parameter that influences diffusion in biological processes. The distribution of intracellular viscosity is highly heterogeneous, and it is challenging to obtain a full map of cellular viscosity with detailed organelle information. In this work, we report 1 as the first fluorescent viscosity probe which is able to quantitatively map cellular viscosity with detailed organelle information based on the PET mechanism. This probe exhibited a significant ratiometric fluorescence intensity enhancement as solvent viscosity increases. The emission intensity increase was attributed to combined effects of the inhibition of PET due to restricted conformational access (favorable for FRET, but not for PET), and the decreased PET efficiency caused by viscosity-dependent twisted intramolecular charge transfer (TICT). A full map of subcellular viscosity was successfully constructed via fluorescent ratiometric detection and fluorescence lifetime imaging; it was found that lysosomal regions in a cell possess the highest viscosity, followed by mitochondrial regions.

  13. Quantitatively Mapping Cellular Viscosity with Detailed Organelle Information via a Designed PET Fluorescent Probe (United States)

    Liu, Tianyu; Liu, Xiaogang; Spring, David R.; Qian, Xuhong; Cui, Jingnan; Xu, Zhaochao


    Viscosity is a fundamental physical parameter that influences diffusion in biological processes. The distribution of intracellular viscosity is highly heterogeneous, and it is challenging to obtain a full map of cellular viscosity with detailed organelle information. In this work, we report 1 as the first fluorescent viscosity probe which is able to quantitatively map cellular viscosity with detailed organelle information based on the PET mechanism. This probe exhibited a significant ratiometric fluorescence intensity enhancement as solvent viscosity increases. The emission intensity increase was attributed to combined effects of the inhibition of PET due to restricted conformational access (favorable for FRET, but not for PET), and the decreased PET efficiency caused by viscosity-dependent twisted intramolecular charge transfer (TICT). A full map of subcellular viscosity was successfully constructed via fluorescent ratiometric detection and fluorescence lifetime imaging; it was found that lysosomal regions in a cell possess the highest viscosity, followed by mitochondrial regions. PMID:24957323

  14. ADE spectral networks (United States)

    Longhi, Pietro; Park, Chan Y.


    We introduce a new perspective and a generalization of spectral networks for 4d {N} = 2 theories of class S associated to Lie algebras {g} = A n , D n , E6, and E7. Spectral networks directly compute the BPS spectra of 2d theories on surface defects coupled to the 4d theories. A Lie algebraic interpretation of these spectra emerges naturally from our construction, leading to a new description of 2d-4d wall-crossing phenomena. Our construction also provides an efficient framework for the study of BPS spectra of the 4d theories. In addition, we consider novel types of surface defects associated with minuscule ccrepresentations of {g}.

  15. Development of spent fuel reprocessing by super-critical fluid (Development of super DIREX method)

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Takashi; Ogumo, Shin-ya; Mori, Yukihide; Ishihara, Nobuo [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Kosaka, Yuji; Ito, Kunihiro [Nuclear Development Corp., Tokai, Ibaraki (Japan)


    Supercritical fluid DIRect EXtraction (Super-DIREX) Method has been developed, and it is the technique of extracting Uranium and Plutonium elements directly from spent fuel oxides by supercritical CO{sub 2} containing HNO{sub 3}-tributylphosphate (TBP) complex (at 313K-333K and 10-20MPa). From this study, it is concluded that the reprocessing system adopting Super-DIREX Method is more simple and unexpensive than PUREX system. The experiment was carried out by using test piece of unirradiated Uranium oxide included imitative fission product (FP) elements oxides, and the results showed that Uranium could be extracted in separating from FP elements at 313K and 12MPa and that one step extraction by Super DIREX Method could get more than 100 of decontamination factor (DE) of the FP elements. (author)

  16. Morphological transformations of native petroleum emulsions. I. Viscosity studies. (United States)

    Evdokimov, Igor N; Efimov, Yaroslav O; Losev, Aleksandr P; Novikov, Mikhail A


    Emulsions of water in as-recovered native crude oils of diverse geographical origin evidently possess some common morphological features. At low volume fractions varphi of water, the viscosity behavior of emulsions is governed by the presence of flocculated clusters of water droplets, whereas characteristic tight gels, composed of visually monodisperse small droplets, are responsible for the viscosity anomaly at varphi approximately 0.4-0.5. Once formed, small-droplet gel domains apparently retain their structural integrity at higher varphi, incorporating/stabilizing new portions of water as larger-sized droplets. The maximum hold-up of disperse water evidently is the close-packing limit of varphi approximately 0.74. At higher water contents (up to varphi approximately 0.83), no inversion to O/W morphology takes place, but additional water emerges as a separate phase. The onset of stratified flow (W/O emulsion gel + free water) is the cause of the observed viscosity decrease, contrary to the conventional interpretation of the viscosity maximum as a reliable indicator of the emulsion inversion point.

  17. Effect of electrochemical oxidation of a viscose rayon based ...

    African Journals Online (AJOL)

    A viscose rayon based activated carbon cloth (ACC) was electrochemically oxidised to enhance its cation sorption capacity for comparison with as-received ACC. ACCs were characterised by sodium capacity measurement, pH titration, zeta potential measurement, elemental analysis, Brunauer-Emmet- Teller surface area ...

  18. The effect of viscosity on ad libitum food intake

    NARCIS (Netherlands)

    Zijlstra, N.; Mars, M.; Wijk, de R.A.; Westerterp-Plantenga, M.; Graaf, de C.


    Background: Energy-yielding liquids elicit weak suppressive appetite responses and weak compensatory responses, suggesting that liquid calories might lead to a positive energy balance. However, data is often derived from foods differing in many characteristics other than viscosity. Objective: To

  19. Upper mantle viscosity and lithospheric thickness under Iceland

    NARCIS (Netherlands)

    Barnhoorn, A.; Wal, W. van der; Drury, M.R.


    Deglaciation during the Holocene on Iceland caused uplift due to glacial isostatic adjustment. Relatively low estimates for the upper mantle viscosity and lithospheric thickness result in rapid uplift responses to the deglaciation cycles on Iceland. The relatively high temperatures of the upper

  20. The effects of gold nanoparticles size and concentration on viscosity ...

    African Journals Online (AJOL)

    This study was carried out to investigate viscosity in relation with the temperature, flow activation energy and dielectric properties for 10, 20 and 50 nm gold nanoparticles size (GNPs) in addition to absorption and fluorescence spectra at different concentrations (0.2 × 10-3 to 1 × 10-2%) in an attempt to cover and understand ...

  1. Viscosity and Electrical Conductivity of Concentrated Solutions of Soluble Coffee

    Czech Academy of Sciences Publication Activity Database

    Sobolík, Václav; Žitný, R.; Tovčigrečko, Valentin; Delgado, M.; Allaf, K.


    Roč. 51, č. 2 (2002), s. 93-98 ISSN 0260-8774 Institutional research plan: CEZ:AV0Z4072921; CEZ:MSM 212200008 Keywords : coffee extract * soluble coffee * viscosity Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.085, year: 2002

  2. On the Role of Viscosity in the Eyring Equation

    NARCIS (Netherlands)

    Kistemaker, Jos C. M.; Lubbe, Anouk S.; Bloemsma, Erik A.; Feringa, Ben L.


    Transition-state theory allows for the characterization of kinetic processes in terms of enthalpy and entropy of activation by using the Eyring equation. However, for reactions in solution, it fails to take the change of viscosity of solvents with temperature into account. A second-generation

  3. Effect of fluid viscosity on fault frictional behavior (United States)

    Cornelio, Chiara; Violay, Marie; Spagnuolo, Elena; Di Toro, Giulio


    Fluids play an important role in fault zone and in earthquakes generation. Fluid pressure reduces the normal effective stress, lowering the frictional strength of the fault, potentially triggering earthquake ruptures. Fluid injection induced earthquakes, such as in geothermal reservoir, are direct evidence of the effect of fluid pressure on the fault strength. However, the frictional fault strength may also vary due to the chemical and physical characteristics of the fluid as discussed here. Here we performed two series of experiments on precut samples of Westerly granite to investigate the role of fluid viscosity on fault frictional behavior. In the first series, we performed 20 rotary shear experiments with the machine SHIVA (INGV, Rome) on cylindrical (50 mm external diameter), at slip rate (V) ranging from 10 μ m/s to 1 m/s effective normal stress (P) of 10 MPa and pore pressure varying from 0 ( i.e., dry conditions) to 2 MPa. Three different fluid viscosities were tested using pure distilled water (η=1 mPa\\cdot s), 40{%}water/60{%}glycerol (η =10.5 mPa\\cdot s) and 15{%}water/85{%}glycerol (η=109 mPa\\cdot s) mixtures (all reported viscosities at 20 rC). In agreement with theoretical argumentations (Stribeck curve) we distinguished three lubrication regimes. At low product of slip-rate per fluid viscosity (S= η\\cdot V/P

  4. Changes in the viscosity and energy density of weaning maize ...

    African Journals Online (AJOL)

    The effect of replacing 25% of the basic maize flour with groundnut paste (w/w) and/or 10% of the liquid ingredients with fresh dairy milk (v/v) on the viscosity and energy density of weaning maize porridge was investigated in a 2• fractional factorial experiment. Other factors investigated included (i) particle size of the flour (ii) ...

  5. Does polar interaction influence medium viscosity? A computer ...

    Indian Academy of Sciences (India)

    Abstract. Molecular dynamics simulations of model liquids interacting via Lennard–Jones (L–J) and. Stockmayer (SM) interactions have been carried out to explore the effects of the longer-ranged dipole–dipole interaction on solvent viscosity and diffusion. Switching on of the dipolar interaction at a fixed density and tem-.

  6. A comparative study of regenerated bamboo, cotton and viscose ...

    African Journals Online (AJOL)

    Apart from the claimed “cool feeling”, the comfort properties referred to in the promotion of bamboo viscose fabrics can generally be ascribed to most cellulose fibres or fabrics. The purpose of this study was to investigate whether the moisture management and thermo-physiological properties of regenerated bamboo fabrics ...

  7. Tension Independence of Lipid Diffusion and Membrane Viscosity. (United States)

    Thoms, Vincent L; Hormel, Tristan T; Reyer, Matthew A; Parthasarathy, Raghuveer


    The diffusion of biomolecules at lipid membranes is governed by the viscosity of the underlying two-dimensionally fluid lipid bilayer. For common three-dimensional fluids, viscosity can be modulated by hydrostatic pressure, and pressure-viscosity data have been measured for decades. Remarkably, the two-dimensional analogue of this relationship, the dependence of molecular mobility on tension, has to the best of our knowledge never been measured for lipid bilayers, limiting our understanding of cellular mechanotransduction as well as the fundamental fluid mechanics of membranes. Here we report both molecular-scale and mesoscopic measures of fluidity in giant lipid vesicles as a function of mechanical tension applied using micropipette aspiration. Both molecular-scale data, from fluorescence recovery after photobleaching, and micron-scale data, from tracking the diffusion of phase-separated domains, show a surprisingly weak dependence of viscosity on tension, in contrast to predictions of recent molecular dynamics simulations, highlighting fundamental gaps in our understanding of membrane fluidity.

  8. The Asymptotic Solution for the Steady Variable-Viscosity Free ...

    African Journals Online (AJOL)

    Under an arbitrary time-dependent heating of an infinite vertical plate (or wall), the steady viscosity-dependent free convection flow of a viscous incompressible fluid is investigated. Using the asymptotic method of solution on the governing equations of motion and energy, the resulting Ordinary differential equations were ...

  9. The Unsteady Variable – Viscosity Free Convection Flow on a ...

    African Journals Online (AJOL)

    The unsteady variable-viscosity free convection flow of a viscous incompressible fluid near an infinite vertical plate (or wall) is investigated under an arbitrary timedependent heating of the plates, and the governing equations of motion and energy transformed into ordinary differential equations. Employing asymptotic ...

  10. Highly Branched Polyethylenes as Lubricant Viscosity and Friction Modifiers

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Joshua W.; Zhou, Yan; Qu, Jun; Bays, John T.; Cosimbescu, Lelia


    A series of highly branched polyethylenes (BPE) were prepared and used in a Group I base oil as potential viscosity and friction modifiers. The lubricating performance of these BPEs supports the expected dual functionality. Changes in polarity, topology, and molecular weight of the BPEs showed significant effects on the lubricants’ performance, which provide scientific insights for polymer design in future lubricant development.

  11. Origin of apparent viscosity in yield stress fluids below yielding

    NARCIS (Netherlands)

    Møller, P.C.F.; Fall, A.; Bonn, D.


    For more than 20 years it has been debated if yield stress fluids are solid below the yield stress or actually flow; whether true yield stress fluids exist or not. Advocates of the true yield stress picture have demonstrated that the effective viscosity increases very rapidly as the stress is

  12. Does polar interaction influence medium viscosity? A computer ...

    Indian Academy of Sciences (India)

    L-J) and Stockmayer (SM) interactions have been carried out to explore the effects of the longer-ranged dipole-dipole interaction on solvent viscosity and diffusion. Switching on of the dipolar interaction at a fixed density and temperature has ...

  13. Bulk viscosity of strange quark matter in density dependent quark ...

    Indian Academy of Sciences (India)

    Abstract. We have studied the bulk viscosity of strange quark matter in the density dependent quark mass model (DDQM) and compared results with calculations done earlier in the MIT bag model where u, d masses were neglected and first order interactions were taken into account. We find that at low temperatures and ...

  14. Intrinsic viscosity of guar gum in sweeteners solutions | Samavati ...

    African Journals Online (AJOL)

    Rheological methods were applied to study the effect of sweeteners on the rheological behavior of guar gum in dilute solutions. The concentration of the sweeteners were 0.1, 0.2%w/v for aspartame, acesulfame-k and cyclamate, and 0.001, 0.002%w/v for neotame. Gum was evaluated for intrinsic viscosity by various ...

  15. Pendulum Underwater--An Approach for Quantifying Viscosity (United States)

    Leme, José Costa; Oliveira, Agostinho


    The purpose of the experiment presented in this paper is to quantify the viscosity of a liquid. Viscous effects are important in the flow of fluids in pipes, in the bloodstream, in the lubrication of engine parts, and in many other situations. In the present paper, the authors explore the oscillations of a physical pendulum in the form of a long…

  16. Phase and viscosity behaviour of refrigerant-lubricant mixtures

    DEFF Research Database (Denmark)

    Cisneros, Sergio; Garcia, J.; Fernandez, J.


    , mainly as a function of the molecular asymmetry. This also has a profound effect in the mixture transport properties. Thus, in this work the general aspects of phase and viscosity behaviour linked to the type of asymmetry found in refrigerant-lubricant mixtures are discussed in the context of phase...

  17. Electrical conductivity and viscosity of borosilicate glasses and melts

    DEFF Research Database (Denmark)

    Ehrt, Doris; Keding, Ralf


    by impedance measurements in a wide temperature range (250 to 1450°C). The activation energies were calculated by Arrhenius plots in various temperature regions: below the glass transition temperature, Tg, above the melting point, Tl, and between Tg and Tl. Viscosity measurements were carried out...

  18. Measuring Viscosity with a Levitating Magnet: Application to Complex Fluids (United States)

    Even, C.; Bouquet, F.; Remond, J.; Deloche, B.


    As an experimental project proposed to students in fourth year of university, a viscometer was developed, consisting of a small magnet levitating in a viscous fluid. The viscous force acting on the magnet is directly measured: viscosities in the range 10-10[superscript 6] mPa s are obtained. This experiment is used as an introduction to complex…

  19. Viscosity solutions of fully nonlinear functional parabolic PDE

    Directory of Open Access Journals (Sweden)

    Liu Wei-an


    Full Text Available By the technique of coupled solutions, the notion of viscosity solutions is extended to fully nonlinear retarded parabolic equations. Such equations involve many models arising from optimal control theory, economy and finance, biology, and so forth. The comparison principle is shown. Then the existence and uniqueness are established by the fixed point theory.

  20. Prothrombin time and relative plasma viscosity of hypertensive ...

    African Journals Online (AJOL)

    A study of the prothrombin time and relative plasma viscosity of hypertensive patients attending University of Calabar Teaching Hospital was conducted. Three hundred (300) male and female subjects aged 25 - 65 years were enrolled for the study. Two hundred (200) subjects were hypertensive, while 100 apparently ...

  1. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz; Hassager, Ole


    The startup and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 kg/mole (PS52K) and 103 kg/mole (PS103K), and for three bidisperse polystyrene melts. The bidisperse melts consist of PS103K or PS52K and a monodisperse...... (closed loop proportional regulator) using the laser in such a way that the stretch rate at the neck is kept constant. The rheometer has been described in more detail in (A. Bach, H.K. Rasmussen and O. Hassager, Journal of Rheology, 47 (2003) 429). PS390K show a decrease in the steady viscosity as a power......-law function of the elongational rate (A. Bach, K. Almdal, H.K. Rasmussen and O. Hassager, Macromolecules 36 (2003) 5174). PS52K and PS103K show that the steady viscosity has a maximum that is respectively 100% and 50% above 3 times the zero-shear-rate viscosity. The bidisperse melts show a significant...

  2. Variable viscosity effects on mixed convection heat and mass ...

    African Journals Online (AJOL)

    An analysis is carried out to study the viscous dissipation and variable viscosity effects on the flow, heat and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate in the presence of chemical reaction. The governing boundary layer equations are written into a dimensionless form by similarity ...

  3. Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, Katherine [Iowa State Univ., Ames, IA (United States)


    The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content with low viscosity in order to produce a high quality product. The addition of a dispersant is useful so that higher solids content suspensions can be used with lower viscosities. For BECy suspensions, the addition of nanoparticles to the BECy resin is expected to enhance the mechanical properties of the cured composite. The addition of saccharides to aqueous suspensions leads to viscosity reduction. Through DSC measurements it was found that the saccharide molecules formed a solution with water and this resulted in lowering the melting temperature of the free water according to classic freezing point depression. Saccharides also lowered the melting temperature of the bound water, but this followed a different rule. The shear thinning and melting behaviors of the suspensions were used to develop a model based on fractal-type agglomeration. It is believed that the structure of the particle flocs in these suspensions changes with the addition of saccharides which leads to the resultant viscosity decrease. The viscosity of the BECy suspensions increased with solids content, and the viscosity increase was greater than predicted by the classical Einstein equation for dilute suspensions. Instead, the Mooney equation fits the viscosity behavior well from 0-20 vol% solids. The viscosity reduction achieved at high particle loadings by the addition of benzoic acid was also investigated by NMR. It appears that the benzoic acid interacts with the surface of the alumina particle which may

  4. Viscosity solutions to delay differential equations in demo-economy


    Fabbri, Giorgio


    Economic and demographic models governed by linear delay differential equations are expressed as optimal control problems in infinite dimensions. A general objective function is considered and the concavity of the Hamiltonian is not required. The value function is a viscosity solution of the Hamilton-Jacobi-Bellman (HJB) equation and a verification theorem is proved.

  5. Effects of iron oxidation state on viscosity, lunar composition 15555 (United States)

    Cukierman, M.; Uhlmann, D. R.


    The viscous flow behavior of a 9.6-kg lunar rock containing 22.5 wt.% FeO was studied in the temperature ranges from 620 to 700 C and from 1215 to 1400 C. The material was synthesized under mildy reducing conditions to simulate the Fe(2+)/total Fe ratio of the lunar environment. The effect of iron oxidation state on flow behavior in the high viscosity region is studied for specimens of the 15555 composition with Fe(2+) concentration ratios of 0.94, 0.76, and 0.20. A change in ratio from 0.94 to 0.76 had no observable effect on viscosity, whereas a change from 0.76 to 0.20 was accompanied by a drastic increase in viscosity (some three orders of magnitude) at a given temperature, but without changing the form of the variation of viscosity with temperature. The flow behavior is analyzed as a function of the structural features of the glasses.

  6. Passive non-linear microrheology for determining extensional viscosity (United States)

    Hsiao, Kai-Wen; Dinic, Jelena; Ren, Yi; Sharma, Vivek; Schroeder, Charles M.


    Extensional viscosity is a key property of complex fluids that greatly influences the non-equilibrium behavior and processing of polymer solutions, melts, and colloidal suspensions. In this work, we use microfluidics to determine steady extensional viscosity for polymer solutions by directly observing particle migration in planar extensional flow. Tracer particles are suspended in semi-dilute solutions of DNA and polyethylene oxide, and a Stokes trap is used to confine single particles in extensional flows of polymer solutions in a cross-slot device. Particles are observed to migrate in the direction transverse to flow due to normal stresses, and particle migration is tracked and quantified using a piezo-nanopositioning stage during the microfluidic flow experiment. Particle migration trajectories are then analyzed using a second-order fluid model that accurately predicts that migration arises due to normal stress differences. Using this analytical framework, extensional viscosities can be determined from particle migration experiments, and the results are in reasonable agreement with bulk rheological measurements of extensional viscosity based on a dripping-onto-substrate method. Overall, this work demonstrates that non-equilibrium properties of complex fluids can be determined by passive yet non-linear microrheology.

  7. Measurement of gas viscosity using photonic crystal fiber (United States)

    Gao, R.-K.; Sheehe, S. L.; Kurtz, J.; O'Byrne, S.


    A new measurement technique for gas viscosity coefficient is designed and demonstrated using the technique of tunable diode laser absorption spectroscopy (TDLAS). Gas flow is driven by a pressure gradient between two gas cells, through a photonic crystal fiber (PCF) surrounded by a furnace for temperature adjustment. PCF with 20-micron diameter affords physical space for gas-light interaction and provides a basis for gas viscosity measurement by determining the time for flow to exit a capillary tube under the influence of a pressure gradient. Infrared radiation from a diode laser is coupled into the fiber to be guided through the gas, and the light attenuation due to absorption from the molecular absorbing species is measured by a photo detector placed at the exit of the fiber. A numerical model from Sharipov and Graur describing local number density distribution in a unsteady state is applied for the determination of gas viscosity, based on the number density of gas measured by the absorption of the laser light, using the Beer-Lambert law. The measurement system is confirmed by measuring the viscosity of CO2 as a reference gas.

  8. Density and viscosity of magnesium sulphate in formamide + ...

    Indian Academy of Sciences (India)

    Abstract. Densities (ρ) and viscosities (η) of different strengths of magnesium sulphate (MgSO4) in varying proportions of formamide (FA) + ethylene glycol as mixed solvents were measured at room temperature. The experimental values of ρ and η were used to calculate the values of the apparent molar volume, (φv), partial ...

  9. Estimation of the viscosities of liquid binary alloys (United States)

    Wu, Min; Su, Xiang-Yu


    As one of the most important physical and chemical properties, viscosity plays a critical role in physics and materials as a key parameter to quantitatively understanding the fluid transport process and reaction kinetics in metallurgical process design. Experimental and theoretical studies on liquid metals are problematic. Today, there are many empirical and semi-empirical models available with which to evaluate the viscosity of liquid metals and alloys. However, the parameter of mixed energy in these models is not easily determined, and most predictive models have been poorly applied. In the present study, a new thermodynamic parameter Δ G is proposed to predict liquid alloy viscosity. The prediction equation depends on basic physical and thermodynamic parameters, namely density, melting temperature, absolute atomic mass, electro-negativity, electron density, molar volume, Pauling radius, and mixing enthalpy. Our results show that the liquid alloy viscosity predicted using the proposed model is closely in line with the experimental values. In addition, if the component radius difference is greater than 0.03 nm at a certain temperature, the atomic size factor has a significant effect on the interaction of the binary liquid metal atoms. The proposed thermodynamic parameter Δ G also facilitates the study of other physical properties of liquid metals.

  10. Variable viscosity effects on mixed convection heat and mass ...

    African Journals Online (AJOL)

    DR OKE

    porous medium, Physics Letters A, Vol. 372, 14, pp 2355-2358. Jayanthi S. and Kumari M., 2007. Effect of variable viscosity on non-Darcy free or mixed convection flow on a vertical surface in a fluid saturated porous medium, Applied Mathematics and Computations, Vol.186, 2, pp 1643-1659. Kafoussius N.G. and Williams ...

  11. Effects of Nattokinase on Whole Blood Viscosity and Mortality

    Directory of Open Access Journals (Sweden)

    Melike Cengiz


    Full Text Available Objective: Nattokinase is a serin protease having potent fibrinolytic effect derived from fermentation of boiled soy bean by the use of Basillus Subtilis Natto. The aim of this experimental study is to investigate the effects of intragastric Nattokinase (6 mg/day administration for 7 days prior to formation of sepsis on plasma fibrinogen levels, whole blood viscosity and mortality in rats. Materials and Methods: Intraabdominal sepsis were performed by cecal ligation and puncture in rats supplemented with nattokinase or olive oil for 7 days prior to sepsis formation. Plasma fibrinogen, whole blood viscosity analysis and survival analysis was performed after intraabdominal sepsis formation. Results: Mean blood viscosity of rats was lower in Nattokinase and cecal ligation group at lowest shear rate (p<0.05. However, the differences between groups were not significant at higher shear rates. No difference was found in survival rates and survival times of Nattokinase and cecal ligation and cecal ligation and puncture groups. Conclusion: Our results were unable to show the effects of intragastric nattokinase supplementation prior to sepsis on plasma fibrinogen levels or whole blood viscosity, except low shear rate. Nattokinase did not altered survival in septic rats. (Journal of the Turkish Society Intensive Care 2011; 9: 85-9

  12. The adhesive strength and initial viscosity of denture adhesives. (United States)

    Han, Jian-Min; Hong, Guang; Dilinuer, Maimaitishawuti; Lin, Hong; Zheng, Gang; Wang, Xin-Zhi; Sasaki, Keiichi


    To examine the initial viscosity and adhesive strength of modern denture adhesives in vitro. Three cream-type denture adhesives (Poligrip S, Corect Cream, Liodent Cream; PGS, CRC, LDC) and three powder-type denture adhesives (Poligrip Powder, New Faston, Zanfton; PGP, FSN, ZFN) were used in this study. The initial viscosity was measured using a controlled-stress rheometer. The adhesive strength was measured according to ISO-10873 recommended procedures. All data were analyzed independently by one-way analysis of variance combined with a Student-Newman-Keuls multiple comparison test at a 5% level of significance. The initial viscosity of all the cream-type denture adhesives was lower than the powder-type adhesives. Before immersion in water, all the powder-type adhesives exhibited higher adhesive strength than the cream-type adhesives. However, the adhesive strength of cream-type denture adhesives increased significantly and exceeded the powder-type denture adhesives after immersion in water. For powder-type adhesives, the adhesive strength significantly decreased after immersion in water for 60 min, while the adhesive strength of the cream-type adhesives significantly decreased after immersion in water for 180 min. Cream-type denture adhesives have lower initial viscosity and higher adhesive strength than powder type adhesives, which may offer better manipulation properties and greater efficacy during application.

  13. Measuring membrane rigidity and viscosity: New methods, and new insights (United States)

    Parthasarathy, Raghuveer


    Lipid membranes are remarkable materials: flexible, two-dimensional fluids whose physical properties guide cellular function. Bending rigidity and viscosity are two of the key mechanical parameters that characterize membranes. Both, however, are challenging to measure. I describe improvements in experimental techniques to quantify the bending modulus and the two-dimensional viscosity of lipid membranes. First, I show that using selective plane illumination microscopy (SPIM, also known as light sheet fluorescence microscopy) to image the thermal fluctuations of freely suspended giant lipid vesicles enables straightforward measurements of membrane rigidity, and also provides insights into changes in rigidity induced by cargo trafficking proteins. Second, I show that tracking both the rotational and translational diffusion of membrane-anchored tracer particles allows quantification of membrane viscosity, measurement of the effective radii of the tracers, and assessment of theoretical models of membrane hydrodynamics. Surprisingly, we find a wide distribution of effective tracer sizes, due presumably to a wide variety of couplings to the membrane. I also provide an example of protein-mediated changes in lipid viscosity.

  14. Anisotropic cosmological models with bulk viscosity and particle ...

    Indian Academy of Sciences (India)

    equations in two types of cosmologies, one with power-law expansion and the other with expo- nential expansion. Cosmological model with power-law expansion has a Big-Bang singularity at time t = 0, whereas the model with exponential expansion has no finite singularity. We study bulk viscosity and particle creation in ...

  15. Anisotropic cosmological models with bulk viscosity and particle ...

    Indian Academy of Sciences (India)

    Particle creation and bulk viscosity are considered as separate irreversible processes. The energy–momentum tensor is modified to accommodate the viscous pressure and creation pressure which is associated with the creation of matter out of gravitational field. A special law of variation of Hubble parameter is applied to ...

  16. Steady shear viscosity of stirred yoghurts with varying ropiness

    NARCIS (Netherlands)

    van Marle, M.E.; van Marle, M.E.; van den Ende, Henricus T.M.; de Kruif, C.G.; de Kruif, C.G.; Mellema, J.


    Stirred yogurt was viewed as a concentrated dispersion of aggregates consisting of protein particles. The steady-shear behavior of three types of stirred yogurt with varying ropiness was investigated experimentally. To describe the shear-dependent viscosity, a microrheological model was used which

  17. A comparative study of regenerated bamboo, cotton and viscose ...

    African Journals Online (AJOL)

    Since regenerated bamboo fibres (also referred to as bamboo viscose) became commercially available in 2006, consumers have been bombarded with contradictory information regarding products made of these fibres, their potential end-uses and their properties. On the one hand, manufacturers and marketers make ...

  18. Sensitivity of viscosity Arrhenius parameters to polarity of liquids (United States)

    Kacem, R. B. H.; Alzamel, N. O.; Ouerfelli, N.


    Several empirical and semi-empirical equations have been proposed in the literature to estimate the liquid viscosity upon temperature. In this context, this paper aims to study the effect of polarity of liquids on the modeling of the viscosity-temperature dependence, considering particularly the Arrhenius type equations. To achieve this purpose, the solvents are classified into three groups: nonpolar, borderline polar and polar solvents. Based on adequate statistical tests, we found that there is strong evidence that the polarity of solvents affects significantly the distribution of the Arrhenius-type equation parameters and consequently the modeling of the viscosity-temperature dependence. Thus, specific estimated values of parameters for each group of liquids are proposed in this paper. In addition, the comparison of the accuracy of approximation with and without classification of liquids, using the Wilcoxon signed-rank test, shows a significant discrepancy of the borderline polar solvents. For that, we suggested in this paper new specific coefficient values of the simplified Arrhenius-type equation for better estimation accuracy. This result is important given that the accuracy in the estimation of the viscosity-temperature dependence may affect considerably the design and the optimization of several industrial processes.

  19. A Search for Water in a Super-Earth Atmosphere: High-resolution Optical Spectroscopy of 55Cancri e (United States)

    Esteves, Lisa J.; de Mooij, Ernst J. W.; Jayawardhana, Ray; Watson, Chris; de Kok, Remco


    We present the analysis of high-resolution optical spectra of four transits of 55Cnc e, a low-density super-Earth that orbits a nearby Sun-like star in under 18 hr. The inferred bulk density of the planet implies a substantial envelope, which, according to mass-radius relationships, could be either a low-mass extended or a high-mass compact atmosphere. Our observations investigate the latter scenario, with water as the dominant species. We take advantage of the Doppler cross-correlation technique, high-spectral resolution, and the large wavelength coverage of our observations to search for the signature of thousands of optical water absorption lines. Using our observations with HDS on the Subaru telescope and ESPaDOnS on the Canada-France-Hawaii Telescope, we are able to place a 3σ lower limit of 10 g mol-1 on the mean-molecular weight of 55Cnc e’s water-rich (volume mixing ratio >10%), optically thin atmosphere, which corresponds to an atmospheric scale-height of ˜80 km. Our study marks the first high-spectral resolution search for water in a super-Earth atmosphere, and demonstrates that it is possible to recover known water-vapor absorption signals in a nearby super-Earth atmosphere, using high-resolution transit spectroscopy with current ground-based instruments.

  20. SuperB: An opportunity to study baryons with beauty and bottom super-nuclei (United States)

    Feliciello, A.


    SuperB is an INFN flagship project for a new high-luminosity heavy-flavor factory. Along with its companion detector, it is dedicated to the search for CP violation effects in the B meson sector with the aim of looking for direct and indirect signals of new physics, beyond the Standard Model. However it could offer as well the opportunity for a systematic, high-statistics study of b baryon properties and for a search for bottom super-nuclei, that is bound nuclear systems with an explicit content of beauty.

  1. Universality of the high-temperature viscosity limit of silicate liquids

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Mauro, John C.; Ellison, Adam J.


    We investigate the high-temperature limit of liquid viscosity by analyzing measured viscosity curves for 946 silicate liquids and 31 other liquids including metallic, molecular, and ionic systems. Our results show no systematic dependence of the high-temperature viscosity limit on chemical...... composition for the studied liquids. Based on theMauro-Yue-Ellison-Gupta-Allan (MYEGA) model of liquid viscosity, the high-temperature viscosity limit of silicate liquids is 10−2.93 Pa·s. Having established this value, there are only two independent parameters governing the viscosity-temperature relation...

  2. Super-resolution algorithm based on sparse representation and wavelet preprocessing for remote sensing imagery (United States)

    Ren, Ruizhi; Gu, Lingjia; Fu, Haoyang; Sun, Chenglin


    An effective super-resolution (SR) algorithm is proposed for actual spectral remote sensing images based on sparse representation and wavelet preprocessing. The proposed SR algorithm mainly consists of dictionary training and image reconstruction. Wavelet preprocessing is used to establish four subbands, i.e., low frequency, horizontal, vertical, and diagonal high frequency, for an input image. As compared to the traditional approaches involving the direct training of image patches, the proposed approach focuses on the training of features derived from these four subbands. The proposed algorithm is verified using different spectral remote sensing images, e.g., moderate-resolution imaging spectroradiometer (MODIS) images with different bands, and the latest Chinese Jilin-1 satellite images with high spatial resolution. According to the visual experimental results obtained from the MODIS remote sensing data, the SR images using the proposed SR algorithm are superior to those using a conventional bicubic interpolation algorithm or traditional SR algorithms without preprocessing. Fusion algorithms, e.g., standard intensity-hue-saturation, principal component analysis, wavelet transform, and the proposed SR algorithms are utilized to merge the multispectral and panchromatic images acquired by the Jilin-1 satellite. The effectiveness of the proposed SR algorithm is assessed by parameters such as peak signal-to-noise ratio, structural similarity index, correlation coefficient, root-mean-square error, relative dimensionless global error in synthesis, relative average spectral error, spectral angle mapper, and the quality index Q4, and its performance is better than that of the standard image fusion algorithms.

  3. Hyperspectral Image Spatial Super-Resolution via 3D Full Convolutional Neural Network

    Directory of Open Access Journals (Sweden)

    Shaohui Mei


    Full Text Available Hyperspectral images are well-known for their fine spectral resolution to discriminate different materials. However, their spatial resolution is relatively low due to the trade-off in imaging sensor technologies, resulting in limitations in their applications. Inspired by recent achievements in convolutional neural network (CNN based super-resolution (SR for natural images, a novel three-dimensional full CNN (3D-FCNN is constructed for spatial SR of hyperspectral images in this paper. Specifically, 3D convolution is used to exploit both the spatial context of neighboring pixels and spectral correlation of neighboring bands, such that spectral distortion when directly applying traditional CNN based SR algorithms to hyperspectral images in band-wise manners is alleviated. Furthermore, a sensor-specific mode is designed for the proposed 3D-FCNN such that none of the samples from the target scene are required for training. Fine-tuning by a small number of training samples from the target scene can further improve the performance of such a sensor-specific method. Extensive experimental results on four benchmark datasets from two well-known hyperspectral sensors, namely hyperspectral digital imagery collection experiment (HYDICE and reflective optics system imaging spectrometer (ROSIS sensors, demonstrate that our proposed 3D-FCNN outperforms several existing SR methods by ensuring higher quality both in reconstruction and spectral fidelity.

  4. Research on viscosity of metal at high pressure (United States)

    Li, Y.; Liu, F.; Ma, X.; Zhang, M.


    A new experimental technique, the flyer-impact method, is proposed in this article to investigate the viscosity coefficient of shocked metals. In this technique, a shock wave with a sinusoidal perturbation on the front is induced by the sinusoidal profile of the impact surface of the sample by use of a two-stage light-gas gun, and the oscillatory damping process of the perturbation amplitude is monitored by electric pins. The damping processes of aluminum at 78 and 101 GPa and iron at 159 and 103 GPa are obtained by this technique, which supplement the existing data by measuring the viscosity coefficient via a dynamic high-pressure method. Applying the formula of Miller and Ahrens to fit the experimental data, the shear viscosity coefficients of aluminum at 78 and 101 GPa are 1350 ± 500 and 1200 ± 500 Pa s, respectively, and those of iron at 159 and 103 GPa are 1150 ± 1000 and 4800 ± 1000 Pa s, respectively. The values measured by the flyer-impact method, approximately 103 Pa s, are consistent with those measured by Sakharov's method, while still greatly differing from those measured by static high-pressure methods. In dynamic high-pressure experiments, the shear viscosity is related to dislocation motion in the solid material, while that in static high-pressure experiments is related to the diffusion motion of atoms or molecules in liquids. Therefore, there are different physical meanings of shear viscosity in dynamic and static high-pressure experiments, and there is no comparability among these results.

  5. Shear viscosity in an anisotropic unitary Fermi gas (United States)

    Samanta, Rickmoy; Sharma, Rishi; Trivedi, Sandip P.


    We consider a system consisting of a strongly interacting, ultracold unitary Fermi gas under harmonic confinement. Our analysis suggests the possibility of experimentally studying, in this system, an anisotropic shear viscosity tensor driven by the anisotropy in the trapping potential. In particular, we suggest that this experimental setup could mimic some features of anisotropic geometries that have recently been studied for strongly coupled field theories which have a dual gravitational description. Results using the AdS/CFT (anti-de Sitter/conformal field theory correspondence) in these theories show that in systems with a background linear potential, certain viscosity components can be made much smaller than the entropy density, parametrically violating the bound proposed by Kovtun, Son, and Starinets (KSS). This intuition, along with results from a Boltzmann analysis that we perform, suggests that a violation of the KSS bound can perhaps occur in the unitary Fermi gas system when it is subjected to a suitable anisotropic trapping potential which may be approximated to be linear in a suitable range of parameters. We give a concrete proposal for an experimental setup where an anisotropic shear viscosity tensor may arise. In such situations, it may also be possible to observe a reduction in the spin-1 component of the shear viscosity from its lowest value observed so far in ultracold Fermi gases. In extreme anisotropic situations, the reduction may be enough to reduce the shear viscosity to entropy ratio below the proposed KSS bound, although this regime is difficult to analyze in a theoretically controlled manner.

  6. Low Melt Viscosity Resins for Resin Transfer Molding (United States)

    Harris, Frank W.


    In recent years, resin transfer molding (RTM) has become one of the methods of choice for high performance composites. Its cost effectiveness and ease of fabrication are major advantages of RTM. RTM process usually requires resins with very low melt viscosity (less than 10 Poise). The optimum RTM resins also need to display high thennal-oxidative stability, high glass transition temperature (T(sub g)), and good toughness. The traditional PMR-type polyimides (e.g. PMR-15) do not fit this requirement, because the viscosities are too high and the nadic endcap cures too fast. High T(sub g), low-melt viscosity resins are highly desirable for aerospace applications and NASA s Reusable Launch Vehicle (RLV) program. The objective of this work is to prepare low-melt viscosity polyimide resins for RTM or resin film infusion (RFI) processes. The approach involves the synthesis of phenylethynyl-terminated imide oligomers. These materials have been designed to minimize their melt viscosity so that they can be readily processed. During the cure, the oligomers undergo both chain extension and crosslinking via the thermal polymerization of the phenylethynyl groups. The Phenylethynyl endcap is preferred over the nadic group due to its high curing temperature, which provides broader processing windows. This work involved the synthesis and polymerization of oligomers containing zig-zag backbones and twisted biphenyl structures. Some A-B type precursors which possessed both nitro and anhydride functionality, or both nitro and amine functionality, were also synthesized in order to obtain the well defined oligomers. The resulting zig-zag structured oligomers were then end-capped with 4-phenylethynylphthalic anhydride (PEPA) for further cure. The properties of these novel imide oligomers are evaluated.

  7. Viscosity of beta-glucan in oat products

    Directory of Open Access Journals (Sweden)



    Full Text Available Oats contain 3-5% of mixed linked beta-glucan, or (1-3, (1-4 â-D-glucan, referred to hereafter as beta-glucan. Oat beta-glucan is a viscous, and soluble dietary fibre component. Soluble and viscous dietary fibres, including the beta-glucan present in oats are associated with two major health promoting effects, i.e. the attenuation of postprandial plasma glucose and insulin levels and the control of cholesterol. Increased viscosity in the intestine delays absorption of glucose and suppresses absorption of cholesterol and reabsorption of bile acids. In spite of its apparent key role physiologically the viscosity of beta-glucan has been discussed relatively little in terms of analytical procedures. In clinical studies performed with oats, the viscosity of beta-glucan has been properly documented in only a few cases. Viscosity of beta-glucan in foods and in the food digest depends on solubility, concentration and molecular weight. A food manufacturer aiming at health-promoting products must pay attention not only to sufficient concentration of beta-glucan (dose in the raw material, but also to the processing methods that will ensure sufficient solubility of beta-glucan and minimize enzymatic or mechanical breakdown of the beta-glucan molecule. We have been working both with different food processes utilising oat fractions high in beta-glucan and with the development of a method for viscosity determination of the soluble beta-glucan fibre. This review discusses some of the aspects related to the development with a method that could predict the behaviour of beta-glucan in oat processing with respect to its anticipated physiological functions.;

  8. Individual lipid encapsulated microbubble radial oscillations: Effects of fluid viscosity. (United States)

    Helfield, Brandon; Chen, Xucai; Qin, Bin; Villanueva, Flordeliza S


    Ultrasound-stimulated microbubble dynamics have been shown to be dependent on intrinsic bubble properties, including size and shell characteristics. The effect of the surrounding environment on microbubble response, however, has been less investigated. In particular, microbubble optimization studies are generally conducted in water/saline, characterized by a 1 cP viscosity, for application in the vasculature (i.e., 4 cP). In this study, ultra-high speed microscopy was employed to investigate fluid viscosity effects on phospholipid encapsulated microbubble oscillations at 1 MHz, using a single, eight-cycle pulse at peak negative pressures of 100 and 250 kPa. Microbubble oscillations were shown to be affected by fluid viscosity in a size- and pressure-dependent manner. In general, the oscillation amplitudes exhibited by microbubbles between 3 and 6 μm in 1 cP fluid were larger than in 4 cP fluid, reaching a maximum of 1.7-fold at 100 kPa for microbubbles 3.8 μm in diameter and 1.35-fold at 250 kPa for microbubbles 4.8 μm in diameter. Simulation results were in broad agreement at 250 kPa, however generally underestimated the effect of fluid viscosity at 100 kPa. This is the first experimental demonstration documenting the effects of surrounding fluid viscosity on microbubble oscillations, resulting in behavior not entirely predicted by current microbubble models.

  9. Intermolecular potential parameters and combining rules determined from viscosity data

    Energy Technology Data Exchange (ETDEWEB)

    Bastien, Lucas A.J.; Price, Phillip N.; Brown, Nancy J.


    The Law of Corresponding States has been demonstrated for a number of pure substances and binary mixtures, and provides evidence that the transport properties viscosity and diffusion can be determined from a molecular shape function, often taken to be a Lennard-Jones 12-6 potential, that requires two scaling parameters: a well depth {var_epsilon}{sub ij} and a collision diameter {sigma}{sub ij}, both of which depend on the interacting species i and j. We obtain estimates for {var_epsilon}{sub ij} and {sigma}{sub ij} of interacting species by finding the values that provide the best fit to viscosity data for binary mixtures, and compare these to calculated parameters using several 'combining rules' that have been suggested for determining parameter values for binary collisions from parameter values that describe collisions of like molecules. Different combining rules give different values for {sigma}{sub ij} and {var_epsilon}{sub ij} and for some mixtures the differences between these values and the best-fit parameter values are rather large. There is a curve in ({var_epsilon}{sub ij}, {sigma}{sub ij}) space such that parameter values on the curve generate a calculated viscosity in good agreement with measurements for a pure gas or a binary mixture. The various combining rules produce couples of parameters {var_epsilon}{sub ij}, {sigma}{sub ij} that lie close to the curve and therefore generate predicted mixture viscosities in satisfactory agreement with experiment. Although the combining rules were found to underpredict the viscosity in most of the cases, Kong's rule was found to work better than the others, but none of the combining rules consistently yields parameter values near the best-fit values, suggesting that improved rules could be developed.

  10. Individual lipid encapsulated microbubble radial oscillations: Effects of fluid viscosity (United States)

    Helfield, Brandon; Chen, Xucai; Qin, Bin; Villanueva, Flordeliza S.


    Ultrasound-stimulated microbubble dynamics have been shown to be dependent on intrinsic bubble properties, including size and shell characteristics. The effect of the surrounding environment on microbubble response, however, has been less investigated. In particular, microbubble optimization studies are generally conducted in water/saline, characterized by a 1 cP viscosity, for application in the vasculature (i.e., 4 cP). In this study, ultra-high speed microscopy was employed to investigate fluid viscosity effects on phospholipid encapsulated microbubble oscillations at 1 MHz, using a single, eight-cycle pulse at peak negative pressures of 100 and 250 kPa. Microbubble oscillations were shown to be affected by fluid viscosity in a size- and pressure-dependent manner. In general, the oscillation amplitudes exhibited by microbubbles between 3 and 6 μm in 1 cP fluid were larger than in 4 cP fluid, reaching a maximum of 1.7-fold at 100 kPa for microbubbles 3.8 μm in diameter and 1.35-fold at 250 kPa for microbubbles 4.8 μm in diameter. Simulation results were in broad agreement at 250 kPa, however generally underestimated the effect of fluid viscosity at 100 kPa. This is the first experimental demonstration documenting the effects of surrounding fluid viscosity on microbubble oscillations, resulting in behavior not entirely predicted by current microbubble models. PMID:26827018

  11. Spectral resolution enhancement of hyperspectral imagery by a multiple-aperture compressive optical imaging system

    Directory of Open Access Journals (Sweden)

    Hoover Fabian Rueda Chacon


    Full Text Available The Coded Aperture Snapshot Spectral Imaging (CASSI system captures the three-dimensional (3D spatio-spectral information of a scene using a set of two-dimensional (2D random-coded Focal Plane Array (FPA measurements. A compressive sensing reconstruc-tion algorithm is then used to recover the underlying spatio-spectral 3D data cube. The quality of the reconstructed spectral images depends exclusively on the CASSI sensing matrix, which is determined by the structure of a set of random coded apertures. In this paper, the CASSI system is generalized by developing a multiple-aperture optical imaging system such that spectral resolution en-hancement is attainable. In the proposed system, a pair of high-resolution coded apertures is introduced into the CASSI system, allow-ing it to encode both spatial and spectral characteristics of the hyperspectral image. This approach allows the reconstruction of super-resolved hyperspectral data cubes, where the number of spectral bands is significantly increased and the quality in the spatial domain is greatly improved. Extensively simulated experiments show a gain in the peak-signal-to-noise ratio (PSNR, along with a better fit of the reconstructed spectral signatures to the original spectral data.

  12. Riesz spectral systems

    NARCIS (Netherlands)

    Guo, B.Z.; Zwart, Heiko J.


    In this paper we study systems in which the system operator, $A$, has a Riesz basis of (generalized) eigenvectors. We show that this class is subset of the class of spectral operators as studied by Dunford and Schwartz. For these systems we investigate several system theoretic properties, like


    African Journals Online (AJOL)

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    60.55) 4.46 ..... The carbon atom C5, bonded to the chlorine atom, appears at ca. 124 ppm in all of the compounds [63, 70]. Table 6. 13C-NMR spectral (APT) data of the compounds (δC, as ppm, in DMSO-d6). Chloro-hydroxyphenyl carbons.

  14. On the Modes of Mantle Convection in Super-Earths (Invited) (United States)

    Bercovici, D.


    The relatively recent discovery of larger-than-Earth extra-solar terrestrial planets has opened up many possibilities for different modes of interior dynamics, including mantle convection. A great deal of basic mineral physics is still needed to understand the state of matter and rheology of these super terrestrials, even assuming similar compositions to Earth (which is itself unlikely given the effect of singular events such as giant impacts and lunar formation). There has been speculation and debate as to whether the larger Rayleigh numbers of super-Earth's would promote plate tectonic style recycling, which is considered a crucial negative feedback for buffering atmospheric CO2 and stabilizing climate through weathering and mineral carbonation. However, models of plate generation through grainsize-reducing damage (see Foley & Bercovici this session) show that the effect of larger Rayleigh numbers is offset by an increase in the lithosphere-mantle viscosity contrast (due to a hotter mantle). Super-Earth's are therefore probably no more (or less) prone to plate tectonics than "normal" Earths; other conditions like surface temperature (and thus orbital position) are more important than size for facilitating plate tectonic cycling, which is of course more in keeping with observations in our own solar system (i.e., the disparity between Earth and Venus). Regardless, two major questions remain. First, what are the other modes of convective recycling that would possibly buffer CO2 and allow for a negative feedback that stabilizes climate? For example, subarial basaltic volcanism associated with plume or diapiric convection could potentially draw down CO2 because of the reactibility of mafic minerals; this mechanism possibly helped trigger Snow Ball events in the Proterozoic Earth during break-up of near-equatorial super-continents. Second, what observations of exo-planets provide tests for theories of tectonics or convective cycling? Spectroscopic techniques are most

  15. Breeding strategies for increasing yield potential in super hybrid rice

    Directory of Open Access Journals (Sweden)

    Shihua CHENG,Xiaodeng ZHAN,Liyong CAO


    Full Text Available Super hybrid rice breeding is a new breeding method combining semi-dwarf breeding and heterosis breeding using germplasm and gene-environment interactions. This paper reviews the breeding strategies of super hybrid rice breeding in China, focusing on the utilization of heterosis of indica and japonica subspecies, construction of ideal plant architecture and pyramiding of disease resistant genes in restorer lines. To develop super hybrid rice, considerable effort should be made to explore genes related with high yield, good quality, resistance to pests and diseases, tolerance to stresses. Molecular breeding methods in combination with crossing techniques should be adopted in super hybrid rice breeding.

  16. Mechanistic Insights into Dye-Decolorizing Peroxidase Revealed by Solvent Isotope and Viscosity Effects

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Ruben [Department; Huang, Gaochao [Department; Meekins, David A. [Department; Geisbrecht, Brian V. [Department; Li, Ping [Department


    Dye-decolorizing peroxidases (DyPs) are a family of H2O2-dependent heme peroxidases that have shown potential applications in lignin degradation and valorization. However, the DyP kinetic mechanism remains underexplored. Using structural biology and solvent isotope (sKIE) and viscosity effects, many mechanistic characteristics have been determined for the B-class ElDyP from Enterobacter lignolyticus. Its structure revealed that a water molecule acts as the sixth axial ligand and two channels at diameters of ~3.0 and 8.0 Å lead to the heme center. A conformational change of ERS* to ERS, which have identical spectral characteristics, was proposed as the final step in DyPs’ bisubstrate Ping-Pong mechanism. This step is also the rate-determining step in ABTS oxidation. The normal KIE of wild-type ElDyP with D2O2 at pD 3.5 suggested that compound 0 deprotonation by the distal aspartate is rate-limiting in the formation of compound I, which is more reactive under acidic pH than under neutral or alkaline pH. The viscosity effects and other biochemical methods implied that the reducing substrate binds with compound I instead of the free enzyme. The significant inverse sKIEs of kcat/KM and kERS* suggested that the aquo release in ElDyP is mechanistically important and may explain the enzyme’s adoption of two-electron reduction for compound I. The distal aspartate is catalytically more important than the distal arginine and plays key roles in determining ElDyP’s optimum acidic pH. The kinetic mechanism of D143H-ElDyP was also briefly studied. The results obtained will pave the way for future protein engineering to improve DyPs’ lignolytic activity.

  17. Mechanistic Insights into Dye-Decolorizing Peroxidase Revealed by Solvent Isotope and Viscosity Effects. (United States)

    Shrestha, Ruben; Huang, Gaochao; Meekins, David A; Geisbrecht, Brian V; Li, Ping


    Dye-decolorizing peroxidases (DyPs) are a family of H 2 O 2 -dependent heme peroxidases, which have shown potential applications in lignin degradation and valorization. However, the DyP kinetic mechanism remains underexplored. Using structural biology and solvent isotope (sKIE) and viscosity effects, many mechanistic characteristics have been uncovered for the B-class El DyP from Enterobacter lignolyticus . Its structure revealed that a water molecule acts as the sixth axial ligand with two channels at diameters of ~3.0 and 8.0 Å leading to the heme center. A conformational change of ERS * to ERS, which have identical spectral characteristics, was proposed as the final step in DyPs' bisubstrate Ping-Pong mechanism. This step is also the rate-determining step in ABTS oxidation. The normal KIE of wild-type El DyP with D 2 O 2 at pH 3.5 suggested that cmpd 0 deprotonation by the distal aspartate is rate-limiting in the formation of cmpd I, which is more reactive under acidic pH than under neutral or alkaline pH. The viscosity effects and other biochemical methods implied that the reducing substrate binds with cmpd I instead of the free enzyme. The significant inverse sKIEs of k cat / K M and k ERS* suggested that the aquo release in DyPs is mechanistically important and may explain the enzyme's adoption of two-electron reduction for cmpd I. The distal aspartate is catalytically more important than the distal arginine and plays key roles in determining DyPs' acidic pH optimum. The kinetic mechanism of D143H- El DyP was also briefly studied. The results obtained will pave the way for future protein engineering to improve DyPs' lignolytic activity.

  18. Wavelength conversion based spectral imaging

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin

    There has been a strong, application driven development of Si-based cameras and spectrometers for imaging and spectral analysis of light in the visible and near infrared spectral range. This has resulted in very efficient devices, with high quantum efficiency, good signal to noise ratio and high...... resolution for this spectral region. Today, an increasing number of applications exists outside the spectral region covered by Si-based devices, e.g. within cleantech, medical or food imaging. We present a technology based on wavelength conversion which will extend the spectral coverage of state of the art...... visible or near infrared cameras and spectrometers to include other spectral regions of interest....

  19. Spectral matching consideration in the design of a novel x-ray image intensifier (United States)

    Yu, Chunyu; Chang, Benkang; Wei, Dianxiu


    In this article, a novel x-ray image intensifier is introduced. It is mainly composed of an x-ray intensifying screen and a low-light-level (L3) image intensifier. In order to obtain a bright enough image, the spectral compatibility among three different combinations of the x-ray intensifying screen and the photocathode is analyzed. The comparison indicates that a (Zn,Cd)S:Ag screen is superior to either a CaWO4 screen or a Gd2O2S :Tb screen when combined with the Super S25 photocathode and spectral compatibility analysis is a useful guide when designing an optoelectronic imaging device.

  20. If d is super-metric, then d/(1+d) is super-metric

    NARCIS (Netherlands)

    Warrens, Matthijs


    If a function d is metric, a well-known result is that d/(1 + d) is also metric. We consider m-ary analogs of the binary notion of semimetric, called hemi-metrics and super-metrics. The metrics are totally symmetric maps from Xm+1 into R≥0. It is shown that, if d is supermetric, then d/(1 + d) is

  1. Atmospheric Neutrino Results from Super-Kamiokande

    CERN Document Server

    Toshito, T


    We present atmospheric neutrino results from a 71 kiloton year (1140 days) exposure of the Super-Kamiokande detector. Our data are well explained by nu /sub mu / to nu /sub tau / 2-flavor oscillations. We update the 3 flavor analysis of contained events. Also we have been attempting to discriminate between the possible oscillating partners of the muon neutrino as being either the tau neutrino or the sterile neutrino. These tests use expected differences due to neutral currents and matter effects to discriminate the possibilities. We find no evidence favoring sterile neutrinos, and reject the hypothesis at 99% confidence level.

  2. Advantages of super-light structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl


    Super-light structures with pearl-chain reinforcement is a new revolutionary technology that opens possibilities of building load-bearing structures much cheaper and with several other advantages compared to traditional constructions of concrete and steel. Some benefits are: 1 Half price or less. 2...... Architectural expressions never seen before. 3 Material savings of more than 50 %. 4 Energy and CO2 savings of more than 50 %. 5 No Scaffolding and cheaper moulds. 6 Improved durability. 7 Extreme thermal insulation. 8 Better indoor-climate. 9 User friendly operation and maintenance. 10 Increased safety...

  3. Production of super-smooth articles

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.


    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  4. Optical trapping with Super-Gaussian beams

    CSIR Research Space (South Africa)



    Full Text Available stream_source_info McLaren1_2013.pdf.txt stream_content_type text/plain stream_size 2236 Content-Encoding UTF-8 stream_name McLaren1_2013.pdf.txt Content-Type text/plain; charset=UTF-8 JT2A.34.pdf Optics in the Life... Sciences Congress Technical Digest © 2013 The Optical Society (OSA) Optical trapping with Super-Gaussian beams Melanie McLaren, Thulile Khanyile, Patience Mthunzi and Andrew Forbes* National Laser Centre, Council for Scientific and Industrial Research...

  5. SuperLU users' guide

    Energy Technology Data Exchange (ETDEWEB)

    Demmel, James W.; Gilbert, John R.; Li, Xiaoye S.


    This document describes a collection of three related ANSI C subroutine libraries for solving sparse linear systems of equations AX = B: Here A is a square, nonsingular, n x n sparse matrix, and X and B are dense n x nrhs matrices, where nrhs is the number of right-hand sides and solution vectors. Matrix A need not be symmetric or definite; indeed, SuperLU is particularly appropriate for matrices with very unsymmetric structure. All three libraries use variations of Gaussian elimination optimized to take advantage both of sparsity and the computer architecture, in particular memory hierarchies (caches) and parallelism.

  6. Evaluation of the synergistic effects of milk proteins in a rapid viscosity analyzer

    National Research Council Canada - National Science Library

    Stephani, Rodrigo; Borges de Souza, Alisson; Leal de Oliveira, Marcone Augusto; Perrone, Ítalo Tuler; Fernandes de Carvalho, Antônio; Cappa de Oliveira, Luiz Fernando


    .... Here, using a rapid viscosity analyzer, we observed the rheological changes in the startup viscosities of 5 PS obtained by combining varying proportions of milk protein concentrate and whey protein...

  7. Viscosity of egg white from hens of different strains fed with commercial and natural additives

    Directory of Open Access Journals (Sweden)

    Fernanda Papa Spada


    Full Text Available Yolk color and egg white (albumen cleanliness and viscosity are important parameters by which consumers judge the quality of eggs. This study aimed to investigate changes in albumen viscosity during storage of eggs for up to 36 days from two different commercial laying hen strains (Carijo Barbada and Isa Brown fed a diet containing annatto (1.5 and 2.0% or a synthetic additive without synthetic colorants (control. Analyses of humidity, albumen height, pH, viscosity, foam formation, and stability were carried out on eggs. Carijo Barbada strain had smaller albumen, lower humidity and higher egg white viscosity than Isa Brown strain; however, with storage, viscosity lowered significantly on both strains. Initially, the addition of 2.0% of annatto or a synthetic additive increased viscosity in both strains, but with storage only the control maintained longer viscosity. Lower viscosity did not change foam density and stability.

  8. Hybrid spectral CT reconstruction (United States)

    Clark, Darin P.


    Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral

  9. Hybrid spectral CT reconstruction.

    Directory of Open Access Journals (Sweden)

    Darin P Clark

    Full Text Available Current photon counting x-ray detector (PCD technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID. In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM. Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with

  10. Hybrid spectral CT reconstruction. (United States)

    Clark, Darin P; Badea, Cristian T


    Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral

  11. Influence of Blood Viscosity on Blood Flow and the Effect of Low Molecular Weight Dextran (United States)

    Dormandy, John A.


    Changes in whole blood viscosity are related to changes in the leg blood flow during infusions of low-molecular-weight dextran and Hartmann's solution. A close inverse correlation exists between changes in viscosity and blood flow, the change in blood flow being about three times greater than the change in blood viscosity. The dextran and Hartmann's solution had a similar effect on blood viscosity and blood flow if corrections are made for the difference in haemodilution. PMID:5129616

  12. Temperature-dependent viscosities of eutectic Al-Si alloys modified with Sr and P

    Energy Technology Data Exchange (ETDEWEB)

    Song Xigui [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China)], E-mail:; Bian Xiufang; Zhang Jingxiang; Zhang Jie [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China)


    The viscosities of eutectic Al-12 wt.%Si alloy and those modified with Sr and P were investigated using high-temperature torsional oscillation viscometer. Strontium decreased melt's viscosity, while phosphorus increased viscosity. Both additional level and means of addition affected the variation of viscosity. The activation energy of viscous flow was strengthened after modification, but the influence of modification on the molar volume was perplexing.

  13. Spectral Anonymization of Data. (United States)

    Lasko, Thomas A; Vinterbo, Staal A


    The goal of data anonymization is to allow the release of scientifically useful data in a form that protects the privacy of its subjects. This requires more than simply removing personal identifiers from the data, because an attacker can still use auxiliary information to infer sensitive individual information. Additional perturbation is necessary to prevent these inferences, and the challenge is to perturb the data in a way that preserves its analytic utility.No existing anonymization algorithm provides both perfect privacy protection and perfect analytic utility. We make the new observation that anonymization algorithms are not required to operate in the original vector-space basis of the data, and many algorithms can be improved by operating in a judiciously chosen alternate basis. A spectral basis derived from the data's eigenvectors is one that can provide substantial improvement. We introduce the term spectral anonymization to refer to an algorithm that uses a spectral basis for anonymization, and we give two illustrative examples.We also propose new measures of privacy protection that are more general and more informative than existing measures, and a principled reference standard with which to define adequate privacy protection.

  14. QCD Shear Viscosity at (almost) NLO arXiv

    CERN Document Server

    Ghiglieri, Jacopo; Teaney, Derek

    We compute the shear viscosity of QCD with matter, including almost all next-to-leading order corrections -- that is, corrections suppressed by one power of $g$ relative to leading order. We argue that the still missing terms are small. The next-to-leading order corrections are large and bring $\\eta/s$ down by more than a factor of 3 at physically relevant couplings. The perturbative expansion is problematic even at $T \\simeq 100$ GeV. The largest next-to-leading order correction to $\\eta/s$ arises from modifications to the qhat parameter, which determines the rate of transverse momentum diffusion. We also explore quark number diffusion, and shear viscosity in pure-glue QCD and in QED.

  15. Effect of ionic surfactants on bauxite residues suspensions viscosity. (United States)

    Clifton, M; Nguyen, T; Frost, Ray


    Measurement of the rheological property of bauxite residue sample received from an Australian alumina refinery, treated with a number of cationic and anionic surfactant in laboratory has been carried out using a Brookfield viscometer for the assessment of the effect of surfactants on the residue viscosity. Sodium laurate, prepared with an excess of sodium hydroxide, was found to be effective while direct addition of anionic surfactants (lauric acid and sodium laureth sulphate) and cationic (cetyl trimethyl ammonium bromide) produce only moderate effect on the red mud suspension apparent viscosity at 65 degrees C. The experimental data appear to confirm the crucial role of the cation sodium in the process of adsorption of anionic surfactants on the flocculated red mud particles.

  16. High Resolution Viscosity Measurement by Thermal Noise Detection

    Directory of Open Access Journals (Sweden)

    Felipe Aguilar Sandoval


    Full Text Available An interferometric method is implemented in order to accurately assess the thermal fluctuations of a micro-cantilever sensor in liquid environments. The power spectrum density (PSD of thermal fluctuations together with Sader’s model of the cantilever allow for the indirect measurement of the liquid viscosity with good accuracy. The good quality of the deflection signal and the characteristic low noise of the instrument allow for the detection and corrections of drawbacks due to both the cantilever shape irregularities and the uncertainties on the position of the laser spot at the fluctuating end of the cantilever. Variation of viscosity below 0.03 mPa·s was detected with the alternative to achieve measurements with a volume as low as 50 µL.

  17. Shear viscosity and entropy of a pion gas

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Jean-Bernard; Oliinychenko, Dmytro; Schaefer, Anna; Petersen, Hannah [FIAS, Goethe University, Frankfurt (Germany)


    A model of microscopic non-equilibrium dynamics for classical point particles is used to calculate the transport coefficients of dense hadronic matter. Specifically, the shear viscosity to entropy density ratio is investigated, and the temperature dependence between 100 MeV and 300 MeV is explored. Calculations are made at corresponding particle densities going from 0.01 to 0.34 in a pion box simulating infinite matter. The results for the entropy and shear viscosity are then compared to analytic estimates. In addition, massless particles as well as ρ-meson resonance excitations are included. This will be the starting point for the calculation of more transport coefficients as functions of T and μ{sub B}; expanding systems could also be considered.

  18. Magnetically-charged black branes and viscosity/entropy ratios

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Shan [Institute for Advanced Physics & Mathematics,Zhejiang University of Technology, Hangzhou 310023 (China); George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University, College Station, TX 77843 (United States); Lü, H. [Department of Physics, Beijing Normal University,Beijing 100875 (China); Pope, C.N. [George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University, College Station, TX 77843 (United States); DAMTP, Centre for Mathematical Sciences,Cambridge University, Wilberforce Road, Cambridge CB3 OWA (United Kingdom)


    We consider asymptotically-AdS n-dimensional black brane solutions in a theory of gravity coupled to a set of Np-form field strengths, in which the field strengths carry magnetic charges. For appropriately chosen charges, the metrics are isotropic in the (n−2) transverse directions. However, in general the field strength configurations break the full Euclidean symmetry of the (n−2)-dimensional transverse space, and the shear viscosity tensor in the dual theory is no longer isotropic. We study the linearised equations for transverse traceless metric perturbations in these backgrounds, and by employing the Kubo formula we obtain expressions for the ratios η/S of the shear viscosity components divided by the entropy density. We find that the KSS bound on the ratios η/S is generally violated in these solutions. We also extend the discussion by including a dilatonic scalar field in the theory, leading to solutions that are asymptotically Lifshitz with hyperscaling violation.

  19. Holographic shear viscosity in hyperscaling violating theories without translational invariance

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Yi [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China); Shanghai Key Laboratory of High Temperature Superconductors,Shanghai 200444 (China); Xian, Zhuoyu; Zhou, Zhenhua [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China)


    In this paper we investigate the ratio of shear viscosity to entropy density, η/s, in hyperscaling violating geometry with lattice structure. We show that the scaling relation with hyperscaling violation gives a strong constraint to the mass of graviton and usually leads to a power law of temperature, η/s∼T{sup κ}. We find the exponent κ can be greater than two such that the new bound for viscosity raised in is violated. Our above observation is testified by constructing specific solutions with UV completion in various holographic models. Finally, we compare the boundedness of κ with the behavior of entanglement entropy and conjecture a relation between them.

  20. Low Viscosity Imides Based on Asymmetric Oxydiphthalic Anhydride (United States)

    Chuang, Kathy C.; Criss, Jim M., Jr.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.


    A series of low-melt viscosity imide resins were prepared from asymmetric oxydiphthalic dianhydride (a-ODPA) and 4-phenylethynylphthalic anhydride as the endcap, along with 3,4' - oxydianiline (3,4' -ODA), 3,4' -methylenedianiline (3,4' -MDA), 3,3' -methylenedianiline (3,3' - MDA) and 3,3'-diaminobenzophenone (3,3'-DABP), using a solvent-free melt process. These imide oligomers displays low-melt viscosities (2-15 poise) at 260-280 C, which made them amenable to low-cost resin transfer molding (RTM) process. The a-ODPA based RTM resins exhibits glass transition temperatures (Tg's) in the range of 265-330 C after postcure at 343 C. The mechanical properties of these polyimide/carbon fiber composites fabricated by RTM will be discussed.