33,142 research outputs found

    Infrared regulators and SCETII

    Full text link
    We consider matching from SCETI, which includes ultrasoft and collinear particles, onto SCETII with soft and collinear particles at one loop. Keeping the external fermions off their mass shell does not regulate all IR divergences in both theories. We give a new prescription to regulate infrared divergences in SCET. Using this regulator, we show that soft and collinear modes in SCETII are sufficient to reproduce all the infrared divergences of SCETI. We explain the relationship between IR regulators and an additional mode proposed for SCETII.Comment: 9 pages. Added discussion about relationship between IR regulators and messenger mode

    Microscopic calculation of the phonon dynamics of Sr2_{2}RuO4_{4} compared with La2_{2}CuO4_{4}

    Full text link
    The phonon dynamics of the low-temperature superconductor Sr2_{2}RuO4_{4} is calculated quantitatively in linear response theory and compared with the structurally isomorphic high-temperature superconductor La2_{2}CuO4_{4}. Our calculation corrects for a typical deficit of LDA-based calculations which always predict a too large electronic kzk_{z}-dispersion insufficient to describe the c-axis response in the real materials. With a more realistic computation of the electronic band structure the frequency and wavevector dependent irreducible polarization part of the density response function is determined and used for adiabatic and nonadiabatic phonon calculations. Our analysis for Sr2_{2}RuO4_{4} reveals important differences from the lattice dynamics of pp- and nn-doped cuprates. Consistent with experimental evidence from inelastic neutron scattering the anomalous doping related softening of the strongly coupling high-frequency oxygen bond-stretching modes (OBSM) which is generic for the cuprate superconductors is largely suppressed or completely absent, respectively, depending on the actual value of the on-site Coulomb repulsion of the Ru4d orbitals. Also the presence of a characteristic Λ1\Lambda_{1}-mode with a very steep dispersion coupling strongly with the electrons is missing in Sr2_{2}RuO4_{4}. Moreover, we evaluate the possibility of a phonon-plasmon scenario for Sr2_{2}RuO4_{4} which has been shown recently to be realistic for La2_{2}CuO4_{4}. In contrast to La2_{2}CuO4_{4} in Sr2_{2}RuO4_{4} the very low lying plasmons are overdamped along the c-axis.Comment: 30 pages, 16 figures, 4 tables, 33 reference

    Wind Tunnel Generation of Sinusoidal Lateral and Longitudinal Gusts by Circulation of Twin Parallel Airfoils

    Get PDF
    A gust generator capable of producing sinusoidal lateral and longitudinal gusts was developed for the purpose of studying the gust response of a model rotor-propeller in a wind tunnel. The gust generator utilized harmonic circulation control of twin parallel airfoils to achieve the harmonic lift variation required for gust generation. The gust generator design, construction, and testing is described. Typical test results are presented in the form of lateral and longitudinal gust perturbation velocities as a function of generator reduced frequency

    THE EFFECTS OF LOW DYE TAPING ON FOOT PRESSURE IN SUBJECTS WITH PLANTAR FASCIITZS

    Get PDF
    The purpose of the investigation was to analyze the effect of low dye taping on vertical foot pressure and the path of the centre of pressure (COP) in individuals with plantar fasciitis. Ten subjects (8 females and 2 males) meeting the diagnostic criteria volunteered as subjects. The mean age of the subjects was 28.4 years. Each subject was k e d under two conditions, walking with low dye taping and walking without. Vertical foot pressure and COP was measured using the F-scan Gait Analysis System. Vertical foot pressure was significantly decreased in the rearfoot and midfoot with the application of low dye taping during contact ( t(9) = 2.46, p < 0.036 ) and midstance ( t(9) = 1.12, p < 0.29 ). Analysis of the COP curves revealed no consistent change. During contact, 6 subjects had no significant change in the COP while 4 subjects indicated a slight lateralization. During midstance 8 subjects displayed no change in the COP while 2 subjects displayed lateralization with the application of low dye taping. During propulsion all subjects displayed no sig cant change in the COP when taped. Throughout contact, midstance and propulsion there was no indication of a tendency towards medialization of the COP. The results of this study supports the research indicating that low dye taping decreases the amount of pressure transmitted through the foot during contact and midstance. However, there was no consistent change in the COP curves with the application of low dye taping. In conclusion, based upon the results of this investigation, low dye taping decreases the foot pressure under the rearfoot during contact and under the midfoot during midstance. Low dye taping had no consistent effect on the COP and did not produce medialization of the COP thereby increasing tension on the plantar fascia. Further study is required on the effects of low dye taping on the gait pattern of patient populations

    Spectral estimates of solar radiation intercepted by corn canopies

    Get PDF
    Reflectance factor data were acquired with a Landsat band radiometer throughout two growing seasons for corn (Zea mays L.) canopies differing in planting dates, populations, and soil types. Agronomic data collected included leaf area index (LAI), biomass, development stage, and final grain yields. The spectral variable, greenness, was associated with 78 percent of the variation in LAI over all treatments. Single observations of LAI or greenness have limited value in predicting corn yields. The proportions of solar radiation intercepted (SRI) by these canopies were estimated using either measured LAI or greenness. Both SRI estimates, when accumulated over the growing season, accounted for approximately 65 percent of the variation in yields. Models which simulated the daily effects of weather and intercepted solar radiation on growth had the highest correlations to grain yields. This concept of estimating intercepted solar radiation using spectral data represents a viable approach for merging spectral and meteorological data for crop yield models

    Green-GEAR

    Get PDF
    The poster describes the approach of the Green-GEAR project that kicked off in September. Green-GEAR tackles three environmental inefficiencies. First (solution 1), barometric altimetry – used since the early days of aviation – suffers from constant variations in pressure caused by the weather, leading to increased vertical profile variability restricting capacity and flight efficiency in today’s high traffic density. Green-GEAR will thus investigate the environmental potential of geometric altimetry enabled by satellite navigation. Second (solution 2), geometric altimetry is an enabler for the integration of new entrants such as RPAS and HAO aircraft, and its increased accuracy is expected to allow reduction of vertical separation en-route (allowing more aircraft to fly at their optimum altitude), which will be analysed in the project. Finally (solution 3), the project will investigate the potential of new route-charging mechanisms that incentivise miminimum climate impact routing

    Repeated Evolution of Digital Adhesion in Geckos: A Reply to Harrington and Reeder

    Get PDF
    We published a phylogenetic comparative analysis that found geckos had gained and lost adhesive toepads multiple times over their long evolutionary history (Gamble et al., PLoS One, 7, 2012, e39429). This was consistent with decades of morphological studies showing geckos had evolved adhesive toepads on multiple occasions and that the morphology of geckos with ancestrally padless digits can be distinguished from secondarily padless forms. Recently, Harrington & Reeder (J. Evol. Biol., 30, 2017, 313) reanalysed data from Gamble et al. (PLoS One, 7, 2012, e39429) and found little support for the multiple origins hypothesis. Here, we argue that Harrington and Reeder failed to take morphological evidence into account when devising ancestral state reconstruction models and that these biologically unrealistic models led to erroneous conclusions about the evolution of adhesive toepads in geckos

    ICONGETM v1.0 – flexible NUOPC-driven two-way coupling via ESMF exchange grids between the unstructured-grid atmosphere model ICON and the structured-grid coastal ocean model GETM

    Get PDF
    Two-way model coupling is important for representing the mutual interactions and feedbacks between atmosphere and ocean dynamics. This work presents the development of the two-way coupled model system ICONGETM, consisting of the atmosphere model ICON and the ocean model GETM. ICONGETM is built on the latest NUOPC coupling software with flexible data exchange and conservative interpolation via ESMF exchange grids. With ICON providing a state-of-the-art kernel for numerical weather prediction on an unstructured mesh and GETM being an established coastal ocean model, ICONGETM is especially suited for high-resolution studies. For demonstration purposes the newly developed model system has been applied to a coastal upwelling scenario in the central Baltic Sea

    Crop identification technology assessment for remote sensing (CITARS). Volume 6: Data processing at the laboratory for applications of remote sensing

    Get PDF
    The results of classifications and experiments for the crop identification technology assessment for remote sensing are summarized. Using two analysis procedures, 15 data sets were classified. One procedure used class weights while the other assumed equal probabilities of occurrence for all classes. Additionally, 20 data sets were classified using training statistics from another segment or date. The classification and proportion estimation results of the local and nonlocal classifications are reported. Data also describe several other experiments to provide additional understanding of the results of the crop identification technology assessment for remote sensing. These experiments investigated alternative analysis procedures, training set selection and size, effects of multitemporal registration, spectral discriminability of corn, soybeans, and other, and analyses of aircraft multispectral data
    • …
    corecore