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Sample records for period non-interacting double

  1. Multidimensional period doubling structures.

    PubMed

    Lee, Jeong Yup; Flom, Dvir; Ben-Abraham, Shelomo I

    2016-05-01

    This paper develops the formalism necessary to generalize the period doubling sequence to arbitrary dimension by straightforward extension of the substitution and recursion rules. It is shown that the period doubling structures of arbitrary dimension are pure point diffractive. The symmetries of the structures are pointed out.

  2. Islets of stability beyond period doubling

    SciTech Connect

    Mackay, R.S.

    1981-11-01

    Period doubling of a periodic orbit of an area preserving map appears to lead to the elimination of all closed invariant curves in the vicinity. We show, however, that there are always islets of stabilhty again beyond the accumulation point of the period doubling sequence.

  3. Period-Doubling Bifurcation in Nonlinear Systems

    NASA Astrophysics Data System (ADS)

    Mao, Jian-Min

    The dependence of the critical exponents, such as the Feigenbaum ratios, of the period-doubling bifurcation on the order of critical point z is studied. The dependence is quantitatively given for one-dimensional dissipative maps. The scaling factor in the period-doubling power spectrum of a class of two-dimensional area-preserving maps is found to approach a universal limit by both fast Fourier transform and autocorrelation-function analysis. The dependence of the fractal dimension on the critical-point order is studied. The variation of the three most commonly used definitions of dimension, viz., the capacity, the information dimension, and the correlation exponent, is computed as a function of z. The numerical values agree very well with analytical estimates. The dependence of the scaling of the period-doubling bifurcation on the dimensionality of the reduced phase space is considered. Especially, the investigation of period-doubling bifurcations in four-dimensional symplectic maps indicates the existence of an universally self-similar period-doubling sequence. The fixed-point map has two unstable directions under the period-doubling operator with two relevant eigenvalues. The four orbital scaling factors have been found. As an extension of the Feigenbaum scaling law for parameter and orbital element, a many-term scaling law is suggested. For one-dimensional dissipative maps, two-dimensional area-preserving maps, and four-dimensional symplectic maps, the many-term scaling law is very well obeyed. New scaling factors have been found.

  4. Critical fluctuations of noisy period-doubling maps

    NASA Astrophysics Data System (ADS)

    Noble, Andrew E.; Karimeddiny, Saba; Hastings, Alan; Machta, Jonathan

    2017-01-01

    We extend the theory of quasipotentials in dynamical systems by calculating, within a broad class of period-doubling maps, an exact potential for the critical fluctuations of pitchfork bifurcations in the weak noise limit. These far-from-equilibrium fluctuations are described by finite-size mean field theory, placing their static properties in the same universality class as the Ising model on a complete graph. We demonstrate that the effective system size of noisy period-doubling bifurcations exhibits universal scaling behavior along period-doubling routes to chaos.

  5. Period-doubling reconstructions of semiconductor partial dislocations

    DOE PAGES

    Park, Ji -Sang; Huang, Bing; Wei, Su -Huai; ...

    2015-09-18

    Atomic-scale understanding and control of dislocation cores is of great technological importance, because they act as recombination centers for charge carriers in optoelectronic devices. Using hybrid density-functional calculations, we present period-doubling reconstructions of a 90° partial dislocation in GaAs, for which the periodicity of like-atom dimers along the dislocation line varies from one to two, to four dimers. The electronic properties of a dislocation change drastically with each period doubling. The dimers in the single-period dislocation are able to interact, to form a dispersive one-dimensional band with deep-gap states. However, the inter-dimer interaction for the double-period dislocation becomes significantly reduced;more » hence, it is free of mid-gap states. The Ga core undergoes a further period-doubling transition to a quadruple-period reconstruction induced by the formation of small hole polarons. Lastly, the competition between these dislocation phases suggests a new passivation strategy via population manipulation of the detrimental single-period phase.« less

  6. Period-doubling reconstructions of semiconductor partial dislocations

    SciTech Connect

    Park, Ji -Sang; Huang, Bing; Wei, Su -Huai; Kang, Joongoo; McMahon, William E.

    2015-09-18

    Atomic-scale understanding and control of dislocation cores is of great technological importance, because they act as recombination centers for charge carriers in optoelectronic devices. Using hybrid density-functional calculations, we present period-doubling reconstructions of a 90° partial dislocation in GaAs, for which the periodicity of like-atom dimers along the dislocation line varies from one to two, to four dimers. The electronic properties of a dislocation change drastically with each period doubling. The dimers in the single-period dislocation are able to interact, to form a dispersive one-dimensional band with deep-gap states. However, the inter-dimer interaction for the double-period dislocation becomes significantly reduced; hence, it is free of mid-gap states. The Ga core undergoes a further period-doubling transition to a quadruple-period reconstruction induced by the formation of small hole polarons. Lastly, the competition between these dislocation phases suggests a new passivation strategy via population manipulation of the detrimental single-period phase.

  7. Universality of the topology of period doubling dynamical systems

    SciTech Connect

    Beiersdorfer, P.

    1983-10-01

    The evolution of the topology of the invariant manifolds of the attractors of 3-D autonomous dynamical systems during period doubling is shown to be universal. The overall topology of the nth attractor is shown to depend only on the topology of the first attractor at birth.

  8. Intriguing triple-mode RR Lyrae star with period doubling

    NASA Astrophysics Data System (ADS)

    Smolec, R.; Soszyński, I.; Udalski, A.; Szymański, M. K.; Pietrukowicz, P.; Skowron, J.; Kozłowski, S.; Poleski, R.; Moskalik, P.; Skowron, D.; Pietrzyński, G.; Wyrzykowski, Ł.; Ulaczyk, K.; Mróz, P.

    2015-03-01

    We report the discovery of an intriguing triple-mode RR Lyrae star found in the Optical Gravitational Lensing Experiment (OGLE) Galactic bulge collection, OGLE-BLG-RRLYR-24137. In the OGLE catalogue, the star was identified as RRd star - double-mode pulsator, pulsating simultaneously in the fundamental and in the first overtone modes. We find that third mode is excited and firmly detect its period doubling. Period ratios are not far from that expected for triple-mode - fundamental, first and third overtone - pulsation. Unfortunately, we cannot reproduce period ratios of the three modes with a consistent set of pulsation models. Therefore the other interpretation, that additional mode is non-radial, is also likely.

  9. Completed double layer boundary element method for periodic suspensions

    NASA Astrophysics Data System (ADS)

    Fan, X.-J.; Phan-Thien, N.; Zheng, R.

    In this paper, a traction-based boundary element method is formulated and implemented for periodic suspensions. Hydrodynamic interaction of particles at infinity is handled by O'Brien's method (1979), which is suitably modified for the adjoint double layer using the mean field values of the traction and the background flow. After a deflation of the extreme eigenvalue -1 of the adjoint double layer operator, an iterative solution strategy is implemented, which solves for the traction field on the surfaces of a group of near-by particles sequentially. Ewald's summation technique is employed, by expressing the adjoint double layer kernel in two sums, one converges rapidly in real space, and the other, in the reciprocal Fourier space. The implementation is tested on a periodic suspension of spheres and spheroids in simple and elongated face-centred cubic arrays, and proved to be very accurate when compared to established results. New results for the intrinsic viscosities of periodic suspensions of cubes and spheroids from moderate to high volume fractions are reported. Based on the numerical data for suspensions of spheroids, a simple modification of the constitutive equation of Hinch and Leal (1972), which was derived for dilute suspension of spheroids, is reported, allowing the constitutive equation to reasonably fit the numerical data at moderate to high concentrations.

  10. Hopf and period-doubling bifurcations in an electromechanical resonator

    NASA Astrophysics Data System (ADS)

    Mahboob, I.; Dupuy, R.; Nishiguchi, K.; Fujiwara, A.; Yamaguchi, H.

    2016-08-01

    An electromechanical resonator is developed in which the dissipation can be dynamically eliminated. The resultant motional dynamics captured by the Van der Pol equation of motion opens up the possibility of a Hopf bifurcation where the mechanical resonance loses stability when the dissipation is eliminated and period-doubling bifurcations when the dissipation becomes negative. In this latter regime, the mechanical spectral response is characterised by multi-stability spanning a bandwidth that is more than an order of magnitude wider than the intrinsic linewidth and it sustains a peak structure that can be tuned by the input used to dynamically manipulate the dissipation.

  11. Orbital periods and component masses of three double white dwarfs

    NASA Astrophysics Data System (ADS)

    Rebassa-Mansergas, A.; Parsons, S. G.; García-Berro, E.; Gänsicke, B. T.; Schreiber, M. R.; Rybicka, M.; Koester, D.

    2017-04-01

    The merger of close double white dwarfs (CDWDs) is one of the favourite evolutionary channels for producing Type Ia supernovae (SN Ia). Unfortunately, current theories of the evolution and formation of CDWDs are still poorly constrained and have several serious uncertainties that affect the predicted SN Ia rates. Moreover, current observational constraints on this evolutionary pathway for SN Ia mainly rely on only 17 double-lined and/or eclipsing CDWDs with measured orbital and stellar parameters for both white dwarfs. In this paper, we present the orbital periods and the individual masses of three new double-lined CDWDs, derived using a new method. This method employs mass ratios, the Hα core ratios and spectral model fitting to constrain the masses of the components of the pair. The three CDWDs are WD0028-474 (Porb = 9.350 ± 0.007 h, M1 = 0.60 ± 0.06 M⊙, M2 = 0.45 ± 0.04 M⊙), HE0410-1137 (Porb = 12.208 ± 0.008 h, M1 = 0.51 ± 0.04 M⊙, M2 = 0.39 ± 0.03 M⊙) and SDSSJ031813.25-010711.7 (Porb = 45.908 ± 0.006 h, among the longest period systems, M1 = 0.40 ± 0.05 M⊙, M2 = 0.49 ± 0.05 M⊙). While the three systems studied here will merge in time-scales longer than the Hubble time and are expected to become single massive ( ≳ 0.9 M⊙) white dwarfs rather than exploding as SN Ia, increasing the small sample of CDWDs with determined stellar parameters is crucial for a better overall understanding of their evolution.

  12. Period doubling induced by thermal noise amplification in genetic circuits

    NASA Astrophysics Data System (ADS)

    Ruocco, G.; Fratalocchi, A.

    2014-11-01

    Rhythms of life are dictated by oscillations, which take place in a wide rage of biological scales. In bacteria, for example, oscillations have been proven to control many fundamental processes, ranging from gene expression to cell divisions. In genetic circuits, oscillations originate from elemental block such as autorepressors and toggle switches, which produce robust and noise-free cycles with well defined frequency. In some circumstances, the oscillation period of biological functions may double, thus generating bistable behaviors whose ultimate origin is at the basis of intense investigations. Motivated by brain studies, we here study an ``elemental'' genetic circuit, where a simple nonlinear process interacts with a noisy environment. In the proposed system, nonlinearity naturally arises from the mechanism of cooperative stability, which regulates the concentration of a protein produced during a transcription process. In this elemental model, bistability results from the coherent amplification of environmental fluctuations due to a stochastic resonance of nonlinear origin. This suggests that the period doubling observed in many biological functions might result from the intrinsic interplay between nonlinearity and thermal noise.

  13. Period doubling induced by thermal noise amplification in genetic circuits

    PubMed Central

    Ruocco, G.; Fratalocchi, A.

    2014-01-01

    Rhythms of life are dictated by oscillations, which take place in a wide rage of biological scales. In bacteria, for example, oscillations have been proven to control many fundamental processes, ranging from gene expression to cell divisions. In genetic circuits, oscillations originate from elemental block such as autorepressors and toggle switches, which produce robust and noise-free cycles with well defined frequency. In some circumstances, the oscillation period of biological functions may double, thus generating bistable behaviors whose ultimate origin is at the basis of intense investigations. Motivated by brain studies, we here study an “elemental” genetic circuit, where a simple nonlinear process interacts with a noisy environment. In the proposed system, nonlinearity naturally arises from the mechanism of cooperative stability, which regulates the concentration of a protein produced during a transcription process. In this elemental model, bistability results from the coherent amplification of environmental fluctuations due to a stochastic resonance of nonlinear origin. This suggests that the period doubling observed in many biological functions might result from the intrinsic interplay between nonlinearity and thermal noise. PMID:25404210

  14. Period doubling induced by thermal noise amplification in genetic circuits.

    PubMed

    Ruocco, G; Fratalocchi, A

    2014-11-18

    Rhythms of life are dictated by oscillations, which take place in a wide rage of biological scales. In bacteria, for example, oscillations have been proven to control many fundamental processes, ranging from gene expression to cell divisions. In genetic circuits, oscillations originate from elemental block such as autorepressors and toggle switches, which produce robust and noise-free cycles with well defined frequency. In some circumstances, the oscillation period of biological functions may double, thus generating bistable behaviors whose ultimate origin is at the basis of intense investigations. Motivated by brain studies, we here study an "elemental" genetic circuit, where a simple nonlinear process interacts with a noisy environment. In the proposed system, nonlinearity naturally arises from the mechanism of cooperative stability, which regulates the concentration of a protein produced during a transcription process. In this elemental model, bistability results from the coherent amplification of environmental fluctuations due to a stochastic resonance of nonlinear origin. This suggests that the period doubling observed in many biological functions might result from the intrinsic interplay between nonlinearity and thermal noise.

  15. The doubling of the superorbital period of Cyg X-1

    NASA Astrophysics Data System (ADS)

    Zdziarski, Andrzej A.; Pooley, Guy G.; Skinner, Gerald K.

    2011-04-01

    We study properties of the superorbital modulation of the X-ray emission of Cyg X-1. We find that it has had a stable period of ˜300 d in soft and hard X-rays and in radio since 2005 until at least 2010, which is about double the previously seen period. This new period, seen in the hard spectral state only, is detected not only in the light curves but also in soft X-ray hardness ratios and in the amplitude of the orbital modulation. On the other hand, the spectral slope in hard X-rays, ≳20 keV, averaged over superorbital bins is constant, and the soft and hard X-rays and the radio emission change in phase. This shows that the superorbital variability consists of changing the normalization of an intrinsic spectrum of a constant shape and of changes of the absorbing column density with the phase. The maximum column density is achieved at the superorbital minimum. The amplitude changes are likely to be caused by a changing viewing angle of an anisotropic emitter, most likely a precessing accretion disc. The constant shape of the intrinsic spectrum shows that this modulation is not caused by a changing accretion rate. The modulated absorbing column density shows the presence of a bulge at the disc edge, as proposed previously. We also find the change of the superorbital period from ˜150 to ˜300 d to be associated with almost unchanged average X-ray fluxes, making the period change difficult to explain in the framework of disc-irradiation models. Finally, we find no correlation of the X-ray and radio properties with the reported detections in the GeV and TeV γ-ray range.

  16. Interacting binaries W Serpentids and double periodic variables

    NASA Astrophysics Data System (ADS)

    Mennickent, R. E.; Otero, S.; Kołaczkowski, Z.

    2016-01-01

    W Serpentids and double periodic variables (DPVs) are candidates for close interacting binaries in a non-conservative evolutionary stage; while W Serpentids are defined by high-excitation ultraviolet emission lines present during most orbital phases, and by usually showing variable orbital periods, DPVs are characterized by a long photometric cycle lasting roughly 33 times the (practically constant) orbital period. We report the discovery of seven new Galactic DPVs, increasing the number of known DPVs in our Galaxy by 50 per cent. We find that DPVs are tangential-impact systems, i.e. their primaries have radii barely larger than the critical Lubow-Shu radius. These systems are expected to show transient discs, but we find that they host stable discs with radii smaller than the tidal radius. Among tangential-impact systems including DPVs and semi-detached Algols, only DPVs have primaries with masses between 7 and 10 M⊙. We find that DPVs are in a Case-B mass transfer stage with donor masses between 1 and 2 M⊙ and with primaries resembling Be stars. W Serpentids are impact and non-impact systems, their discs extend until the last non-intersecting orbit and show a larger range of stellar mass and mass ratio than DPVs. Infrared photometry reveals significant colour excesses in many DPVs and W Serpentids, usually larger for the latter ones, suggesting variable amounts of circumstellar matter.

  17. Understanding a Period-Doubling Bifurcation in Cardiac Cells

    NASA Astrophysics Data System (ADS)

    Berger, Carolyn; Zhao, Xiaopeng; Schaeffer, David; Idriss, Salim; Gauthier, Daniel

    2008-03-01

    Bifurcations in the electrical response of cardiac tissue can destabilize spatio-temporal waves of electrochemical activity in the heart, leading to tachycardia or even fibrillation. Therefore, it is important to classify these bifurcations so that we can understand the mechanisms that cause instabilities in cardiac tissue. We have determined that the period-doubling bifurcation in paced myocardium is of the unfolded border-collision type. To understand how this new type of bifurcation manifest itself in cardiac tissue, we have also studied the role of calcium in inducing the bifurcation. We will discuss the nature of the unfolded border-collision bifurcation and present our results of dual voltage and calcium measurements in a frog ventricle preparation.

  18. Period-doubling and period-tripling in growing bilayered systems

    NASA Astrophysics Data System (ADS)

    Budday, Silvia; Kuhl, Ellen; Hutchinson, John W.

    2015-10-01

    Growing layers on elastic substrates are capable of creating a wide variety of surface morphologies. Moderate growth generates a regular pattern of sinusoidal wrinkles with a homogeneous energy distribution. While the critical conditions for periodic wrinkling have been extensively studied, the rich pattern formation beyond this first instability point remains poorly understood. Here, we show that upon continuing growth, the energy progressively localizes and new complex morphologies emerge. Previous studies have often overlooked these secondary bifurcations; they have focused on large stiffness ratios between layer and substrate, where primary instabilities occur early, long before secondary instabilities emerge. We demonstrate that secondary bifurcations are particularly critical in the low stiffness ratio regime, where the critical conditions for primary and secondary instabilities move closer together. Amongst all possible secondary bifurcations, the mode of period-doubling plays a central role - it is energetically favourable over all other modes. Yet, we can numerically suppress period-doubling, by choosing boundary conditions, which favour alternative higher order modes. Our results suggest that in the low stiffness regime, pattern formation is highly sensitive to small imperfections: surface morphologies emerge rapidly, change spontaneously and quickly become immensely complex. This is a common paradigm in developmental biology. Our results have significant applications in the morphogenesis of living systems where growth is progressive and stiffness ratios are low.

  19. Double resonant processes in 1D nonlinear periodic media

    NASA Astrophysics Data System (ADS)

    Kuzmiak, Vladimir; Konotop, Vladimir

    2001-03-01

    We consider one-dimensional periodic structure consisting of alternating layers fabricated from the materials possessing \\chi^(2) nonlinearity and assume that the filling fraction and the dielectric permittivities of the slabs are chosen in such a way that resonant contions for the generation for the second and third harmonic are satisfied simultaneously. The possibility of such process is demonstrated in the structure consisting of the alternating slabs of AlGaAs and InSb. The wave evolution is described in terms of envelope function approach. By taking account three resonant waves one obtains a system of coupled-mode differential equations. One of the solutions which is of special importance is that of having a constant amplitude and the first and third harmonic having zero amplitude. We analyze the stability of the solutions and show that the use of the double resonance allows one to obtain difference generation. A particular example of such a process is fractional conversion ω arrow (2/3)ω which takes place with the participation of the mode with the frequency ω/3.

  20. Dynamics of wavepacket tunneling in a periodic double-well potential

    NASA Astrophysics Data System (ADS)

    Shundalov, M. B.; Romanov, O. G.

    2008-05-01

    Temporal evolution of wavepacket tunneling in a periodic double-well torsional potential has been studied numerically. Peculiarities of wavepacket tunneling dynamics under conditions of asymmetric distortion of the periodic potential function have been analyzed.

  1. Optical properties of multilayered Period-Doubling and Rudin-Shapiro porous silicon dielectric heterostructures

    NASA Astrophysics Data System (ADS)

    Agarwal, V.; Mora-Ramos, Miguel E.; Alvarado-Tenorio, B.

    2009-05-01

    To investigate the optical properties in quasi-regular porous-silicon-based dielectric Period-Doubling and Rudin-Shapiro multilayer systems, we study here the reflection of light from these structures. The Period-Doubling and Rudin-Shapiro structures are fabricated in such a way that the optical thickness of each layer is one quarter of 600 and 640 nm respectively. We find that porous silicon Period-Doubling dielectric multilayers could demonstrate the optical properties similar to the classical periodic Febry-Perot interference filters with one or multiple resonant peaks, but with an advantage of having total optical thickness much lesser than the periodic structures. Additionally, light propagation in porous silicon Rudin-Shapiro structures is investigated for the first time, both theoretically and experimentally. The reflectance spectra of the structures exhibit photonic band gaps centered at predetermined wavelengths. In both cases, numerical simulation of light transmission is performed using transfer matrix method.

  2. Period-doubling bifurcation and high-order resonances in RR Lyrae hydrodynamical models

    NASA Astrophysics Data System (ADS)

    Kolláth, Z.; Molnár, L.; Szabó, R.

    2011-06-01

    We investigated period doubling, a well-known phenomenon in dynamical systems, for the first time in RR Lyrae models. These studies provide theoretical background for the recent discovery of period doubling in some Blazhko RR Lyrae stars with the Kepler space telescope. Since period doubling has been observed only in Blazhko-modulated stars so far, the phenomenon can help in understanding the modulation as well. Utilizing the Florida-Budapest turbulent convective hydrodynamical code, we have identified the phenomenon in both radiative and convective models. A period-doubling cascade was also followed up to an eight-period solution, confirming that destabilization of the limit cycle is indeed the underlying phenomenon. Floquet stability roots were calculated to investigate the possible causes and occurrences of the phenomenon. A two-dimensional diagnostic diagram was constructed to illustrate the various resonances between the fundamental mode and the different overtones. Combining the two tools, we confirmed that the period-doubling instability is caused by a 9:2 resonance between the ninth overtone and the fundamental mode. Destabilization of the limit cycle by a resonance of a high-order mode is possible because the overtone is a strange mode. The resonance is found to be strong enough to shift the period of overtone by up to 10 per cent. Our investigations suggest that a more complex interplay of radial (and presumably non-radial) modes could happen in RR Lyrae stars that might have connections with the Blazhko effect as well.

  3. A double expansion method for the frequency response of finite-length beams with periodic parameters

    NASA Astrophysics Data System (ADS)

    Ying, Z. G.; Ni, Y. Q.

    2017-03-01

    A double expansion method for the frequency response of finite-length beams with periodic distribution parameters is proposed. The vibration response of the beam with spatial periodic parameters under harmonic excitations is studied. The frequency response of the periodic beam is the function of parametric period and then can be expressed by the series with the product of periodic and non-periodic functions. The procedure of the double expansion method includes the following two main steps: first, the frequency response function and periodic parameters are expanded by using identical periodic functions based on the extension of the Floquet-Bloch theorem, and the period-parametric differential equation for the frequency response is converted into a series of linear differential equations with constant coefficients; second, the solutions to the linear differential equations are expanded by using modal functions which satisfy the boundary conditions, and the linear differential equations are converted into algebraic equations according to the Galerkin method. The expansion coefficients are obtained by solving the algebraic equations and then the frequency response function is finally determined. The proposed double expansion method can uncouple the effects of the periodic expansion and modal expansion so that the expansion terms are determined respectively. The modal number considered in the second expansion can be reduced remarkably in comparison with the direct expansion method. The proposed double expansion method can be extended and applied to the other structures with periodic distribution parameters for dynamics analysis. Numerical results on the frequency response of the finite-length periodic beam with various parametric wave numbers and wave amplitude ratios are given to illustrate the effective application of the proposed method and the new frequency response characteristics, including the parameter-excited modal resonance, doubling-peak frequency response

  4. Incidence of double ovulation during the early postpartum period in lactating dairy cows.

    PubMed

    Kusaka, Hiromi; Miura, Hiroshi; Kikuchi, Motohiro; Sakaguchi, Minoru

    2017-03-15

    In lactating cattle, the incidence of twin calving has many negative impacts on production and reproduction in dairy farming. In almost all cases, natural twinning in dairy cattle is the result of double ovulation. It has been suggested that the milk production level of cows influences the number of ovulatory follicles. The objective of the present study was to investigate the incidence of double ovulations during the early postpartum period in relation to the productive and reproductive performance of dairy cows. The ovaries of 43 Holstein cows (26 primiparous and 17 multiparous) were ultrasonographically scanned throughout the three postpartum ovulation sequences. The incidence of double ovulation in the unilateral ovaries was 66.7%, with a higher incidence in the right ovary than in the left, whereas that in bilateral ovaries was 33.3%. When double ovulations were counted dividing into each side ovary in which ovulations occurred, the total frequency of ovulations deviated from a 1:1 ratio (60.3% in the right side and 39.7% in the left side, P < 0.05). In multiparous cows, double ovulation occurred more frequently than in primiparous cows (58.8% vs. 11.5% per cow and 30.0% vs. 3.8% per ovulation, respectively P < 0.01). The double ovulators experienced more anovulatory repeated waves of follicles before their first ovulations than the single ovulators, which resulted in an extension of the period from parturition to third ovulation (81.5 days vs. 64.2 days, P < 0.05). In the multiparous cows, the double ovulators exhibited higher peak milk yield (P < 0.01) with lower milk lactose concentration (P < 0.05), indicating the prevalence of a more severe negative energy balance during the postpartum 3-month compared to the multiparous single ovulators. Our results showed that, regardless of their parity, double ovulation had no impact on the reproductive performance of the cows. Two multiparous cows that experienced double ovulation during the early

  5. Cascade of Spatio-Temporal Period-Doubling Bifurcations in Connection with the Appearance and Dynamics of Non-Concentric Multiple Double Layers in Plasma

    SciTech Connect

    Dimitriu, D. G.; Ivan, L. M.

    2008-03-19

    Experimental results are presented that reveal a complex route to chaos in plasma, in which a Feigenbaum scenario (cascade of temporal period-doubling bifurcation) develops simultaneously with a cascade of spatial period-doubling bifurcations, in connection with the appearance of a non-concentric multiple double layers structure. The Feigenbaum scenario is identified in the time series of the oscillations of the current through the plasma conductor.

  6. New Double Periodic Solutions of the Classical Drinfel'd-Sokolov-Wilson Equation

    SciTech Connect

    Chen Huaitang

    2008-09-01

    The elliptic equation method is extended for constructing exact travelling wave solutions of nonlinear partial differential equations(PDEs). With the aid of Maple, more new double periodic solutions are obtained for the classical Drinfel'd-Sokolov-Wilson equation. This method can be applied to other PDEs.

  7. Multiparameter Critical Situations, Universality and Scaling in Two-Dimensional Period-Doubling Maps

    NASA Astrophysics Data System (ADS)

    Kuznetsov, S. P.; Kuznetsov, A. P.; Sataev, I. R.

    2005-12-01

    We review critical situations, linked with period-doubling transition to chaos, which require using at least two-dimensional maps as models representing the universality classes. Each of them corresponds to a saddle solution of the two-dimensional generalization of Feigenbaum-Cvitanović equation and is characterized by a set of distinct universal constants analogous to Feigenbaum's α and δ. One type of criticality designated H was discovered by several authors in 80-th in the context of period doubling in conservative dynamics, but occurs as well in dissipative dynamics, as a phenomenon of codimension 2. Second is bicritical behavior, which takes place in systems allowing decomposition onto two dissipative period-doubling subsystems, each of which is brought by parameter tuning onto a threshold of chaos. Types of criticality designated as FQ and C occur in non-invertible two-dimensional maps. We present and discuss a number of realistic systems manifesting those types of critical behavior and point out some relevant conditions of their potential observation in physical systems. In particular, we indicate a possibility for realization of the H type criticality without vanishing dissipation, but with its compensation in a self-oscillatory system. Next, we present a number of examples (coupled Hénon-like maps, coupled driven oscillators, coupled chaotic self-oscillators), which manifest bicritical behavior. For FQ-type we indicate possibility to arrange it in non-symmetric systems of coupled period-doubling subsystems, e.g. in Hénon-like maps and in Chua's circuits. For C-type we present examples of its appearance in a driven Rössler oscillator at the period-doubling accumulation on the edge of syncronization tongue and in a model map with the Neimark-Sacker bifurcation

  8. First observations of W Virginis stars with K2: detection of period doubling

    NASA Astrophysics Data System (ADS)

    Plachy, E.; Molnár, L.; Jurkovic, M. I.; Smolec, R.; Moskalik, P. A.; Pál, A.; Szabados, L.; Szabó, R.

    2017-02-01

    We present the first analysis of W Vir stars observed by the Kepler space telescope in the K2 mission. Clear cycle-to-cycle variations were detected in the light curves of KT Sco and the globular cluster member M80-V1. While the variations in the former star seem to be irregular on the short time-scale of the K2 data, the latter appears to experience period doubling in its pulsation. Ground-based colour data confirmed that both stars are W Vir-type pulsators, while a comparison with historical photometric time series data revealed drastic period changes in both stars. For comparison we reexamine ground-based observations of W Vir, the prototype of the class, and conclude that it shows period doubling instead of mode beating. These results support the notion that non-linear dynamics plays an important role in the pulsation of W Virginis-type stars.

  9. A novel heterodyne displacement interferometer with no detectable periodic nonlinearity and optical resolution doubling

    SciTech Connect

    Joo, K; Ellis, J D; Buice, E S; Spronck, J W; Munnig Schmidt, R H

    2010-02-05

    This paper describes a novel heterodyne laser interferometer with no significant periodic nonlinearity for linear displacement measurements. Moreover, the optical configurations have the benefit of doubling the measurement resolution when compared to its respective traditional counterparts. Experimental results show no discernable periodic nonlinearity for a retro-reflector interferometer and plane mirror interferometer configurations with a noise level below 20 pm. The incoming laser beams of the interferometers are achieved by utilizing two single mode optical fibers. To determine the stability of the optical fiber couplers a fiber delivery prototype was also built and tested.

  10. Period doubling and other nonlinear phenomena in volcanic earthquakes and tremor

    USGS Publications Warehouse

    Julian, B.R.

    2000-01-01

    Evidence of subharmonic period-doubling cascades has recently been recognized in seismograms of volcanic tremor from several volcanoes. This phenomenon occurs only in nonlinear systems, and is the commonest route by which such systems change from periodic to chaotic behavior. It is predicted to occur in a model of volcanic tremor excitation by flow-induced vibration, and it might well also occur in other volcano-seismic source process. If the possibility of period doubling is not taken into account in interpreting spectra of tremor and long-period earthquakes, then low-frequency "sub-harmonic" oscillations may be mis-identified as normal modes of a linear acoustic resonator, leading to errors of an order of magnitude or more in inferred magma-body dimensions. This example illustrates the importance of nonlinear phenomena in attempts to understand volcano-seismic phenomena physically. Linear systems are fundamentally incapable of causing earthquakes or exciting tremor, so nonlinearity is essential to any theory of volcano-seismic phenomena. Nonlinear processes are in many respects qualitatively different from linear ones. A few of their characteristics that might be relevant in volcanoes include the possibility: (1) that damping might increase, rather than decrease, oscillation frequencies; and (2) that these frequencies might be functions of the amplitude of oscillation, so that temporal variations in spectral peak frequencies might not be manifestations of changes of conditions within the magmatic system.

  11. Period doubling and other nonlinear phenomena in volcanic earthquakes and tremor

    NASA Astrophysics Data System (ADS)

    Julian, B. R.

    2000-08-01

    Evidence of subharmonic period-doubling cascades has recently been recognized in seismograms of volcanic tremor from several volcanoes. This phenomenon occurs only in nonlinear systems, and is the commonest route by which such systems change from periodic to chaotic behavior. It is predicted to occur in a model of volcanic tremor excitation by flow-induced vibration, and it might well also occur in other volcano-seismic source process. If the possibility of period doubling is not taken into account in interpreting spectra of tremor and long-period earthquakes, then low-frequency "sub-harmonic" oscillations may be mis-identified as normal modes of a linear acoustic resonator, leading to errors of an order of magnitude or more in inferred magma-body dimensions. This example illustrates the importance of nonlinear phenomena in attempts to understand volcano-seismic phenomena physically. Linear systems are fundamentally incapable of causing earthquakes or exciting tremor, so nonlinearity is essential to any theory of volcano-seismic phenomena. Nonlinear processes are in many respects qualitatively different from linear ones. A few of their characteristics that might be relevant in volcanoes include the possibility: (1) that damping might increase, rather than decrease, oscillation frequencies; and (2) that these frequencies might be functions of the amplitude of oscillation, so that temporal variations in spectral peak frequencies might not be manifestations of changes of conditions within the magmatic system.

  12. The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

    SciTech Connect

    Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

    2013-06-15

    Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.

  13. Multiple period-doubling bifurcation route to chaos in periodically pulsed Murali-Lakshmanan-Chua circuit-controlling and synchronization of chaos.

    PubMed

    Parthasarathy, S; Manikandakumar, K

    2007-12-01

    We consider a simple nonautonomous dissipative nonlinear electronic circuit consisting of Chua's diode as the only nonlinear element, which exhibit a typical period doubling bifurcation route to chaotic oscillations. In this paper, we show that the effect of additional periodic pulses in this Murali-Lakshmanan-Chua (MLC) circuit results in novel multiple-period-doubling bifurcation behavior, prior to the onset of chaos, by using both numerical and some experimental simulations. In the chaotic regime, this circuit exhibits a rich variety of dynamical behavior including enlarged periodic windows, attractor crises, distinctly modified bifurcation structures, and so on. For certain types of periodic pulses, this circuit also admits transcritical bifurcations preceding the onset of multiple-period-doubling bifurcations. We have characterized our numerical simulation results by using Lyapunov exponents, correlation dimension, and power spectrum, which are found to be in good agreement with the experimental observations. Further controlling and synchronization of chaos in this periodically pulsed MLC circuit have been achieved by using suitable methods. We have also shown that the chaotic attractor becomes more complicated and their corresponding return maps are no longer simple for large n-periodic pulses. The above study also indicates that one can generate any desired n-period-doubling bifurcation behavior by applying n-periodic pulses to a chaotic system.

  14. Oscillations, period doublings, and chaos in CO oxidation and catalytic mufflers

    NASA Astrophysics Data System (ADS)

    Marek, Miloš; Schejbal, Matyáš; Kočí, Petr; Nevoral, Vladislav; Kubíček, Milan; Hadač, Otto; Schreiber, Igor

    2006-09-01

    Early experimental observations of chaotic behavior arising via the period-doubling route for the CO catalytic oxidation both on Pt (110) and Pt /γ-Al2O3 porous catalyst were reported more than 15 years ago. Recently, a detailed kinetic reaction scheme including over 20 reaction steps was proposed for the catalytic CO oxidation, NOx reduction, and hydrocarbon oxidation taking place in a three-way catalyst (TWC) converter, the most common reactor for detoxification of automobile exhaust gases. This reactor is typically operated with periodic variation of inlet oxygen concentration. For an unforced lumped model, we report results of the stoichiometric network analysis of a CO reaction subnetwork determining feedback loops, which cause the oscillations within certain regions of parameters in bifurcation diagrams constructed by numerical continuation techniques. For a forced system, numerical simulations of the CO oxidation reveal the existence of a period-doubling route to chaos. The dependence of the rotation number on the amplitude and period of forcing shows a typical bifurcation structure of Arnold tongues ordered according to Farey sequences, and positive Lyapunov exponents for sufficiently large forcing amplitudes indicate the presence of chaotic dynamics. Multiple periodic and aperiodic time courses of outlet concentrations were also found in simulations using the lumped model with the full TWC kinetics. Numerical solutions of the distributed model in two geometric coordinates with the CO oxidation subnetwork consisting of several tens of nonlinear partial differential equations show oscillations of the outlet reactor concentrations and, in the presence of forcing, multiple periodic and aperiodic oscillations. Spatiotemporal concentration patterns illustrate the complexity of processes within the reactor.

  15. Longitudinal polarization periodicity of unpolarized light passing through a double wedge depolarizer.

    PubMed

    de Sande, Juan Carlos G; Santarsiero, Massimo; Piquero, Gemma; Gori, Franco

    2012-12-03

    The polarization characteristics of unpolarized light passing through a double wedge depolarizer are studied. It is found that the degree of polarization of the radiation propagating after the depolarizer is uniform across transverse planes after the depolarizer, but it changes from one plane to another in a periodic way giving, at different distances, unpolarized, partially polarized, or even perfectly polarized light. An experiment is performed to confirm this result. Measured values of the Stokes parameters and of the degree of polarization are in complete agreement with the theoretical predictions.

  16. Resonance spiking by periodic loss in the double-sided liquid cooling disk oscillator

    NASA Astrophysics Data System (ADS)

    Nie, Rongzhi; She, Jiangbo; Li, Dongdong; Li, Fuli; Peng, Bo

    2017-03-01

    A double-sided liquid cooling Nd:YAG disk oscillator working at a pump repetition rate of 20 Hz is demonstrated. The output energy of 376 mJ is realized, corresponding to the optical–optical efficiency of 12.8% and the slope efficiency of 14%. The pump pulse width is 300 µs and the laser pulse width is 260 µs. Instead of being a damped signal, the output of laser comprises undamped spikes. A periodic intra-cavity loss was found by numerical analysis, which has a frequency component near the eigen frequency of the relaxation oscillation. Resonance effect will induce amplified spikes even though the loss fluctuates in a small range. The Shark–Hartmann sensor was used to investigate the wavefront aberration induced by turbulent flow and temperature gradient. According to the wavefront and fluid mechanics analysis, it is considered that the periodic intra-cavity loss can be attributed to turbulent flow and temperature gradient.

  17. Asynchronous Periodic Edge-Event Triggered Control for Double-Integrator Networks With Communication Time Delays.

    PubMed

    Duan, Gaopeng; Xiao, Feng; Wang, Long

    2017-01-23

    This paper focuses on the average consensus of double-integrator networked systems based on the asynchronous periodic edge-event triggered control. The asynchronous property lies in the edge event-detecting procedure. For different edges, their event detections are performed at different times and the corresponding events occur independently of each other. When an event is activated, the two adjacent agents connected by the corresponding link sample their relative state information and update their controllers. The application of incidence matrix facilitates the transformation of control objects from the agent-based to the edge-based. Practically, due to the constraints of network bandwidth and communication distance, agents usually cannot receive the instantaneous information of some others, which has an impact on the system performance. Hence, it is necessary to investigate the presence of communication time delays. For double-integrator multiagent systems with and without communication time delays, the average state consensus can be asynchronously achieved by designing appropriate parameters under the proposed event-detecting rules. The presented results specify the relationship among the maximum allowable time delays, interaction topologies, and event-detecting periods. Furthermore, the proposed protocols have the advantages of reduced communication costs and controller-updating costs. Simulation examples are given to illustrate the proposed theoretical results.

  18. Discovery of a double eclipsing binary with periods near a 3:2 ratio

    NASA Astrophysics Data System (ADS)

    Cagaš, P.; Pejcha, O.

    2012-08-01

    The evolution of multiple stellar systems can be driven by Kozai cycles and tidal friction (KCTF), which shrink the orbit of the inner binary. There is an interesting possibility that two close binaries on a common long-period orbit experience mutually-induced KCTF. We present the discovery of a possible new quadruple system composed of two unresolved eclipsing binaries (EBs), CzeV343 (V ~ 13.5 mag). We obtained photometric observations of CzeV343 that completely cover the two orbital periods and we successfully model the light curves as the sum of two detached EBs. We provide confidence intervals for the model parameters and minima timings by bootstrap resampling of our data. One of the EBs shows a distinctly eccentric orbit with a total eccentricity of about 0.18. The two orbital periods, 1.20937 and 0.80693 days, are within 0.1% of a 3:2 ratio. We speculate that this might be the result of KCTF-driven evolution of a quadruple system and we discuss this hypothesis in the context of other quadruple systems composed of two EBs. We make our double EB fitting code publicly available to provide a tool for long-term monitoring of the mutual orbit in such systems. Photometric measurements are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/544/L3

  19. Hyperpolarization-Activated Current Induces Period-Doubling Cascades and Chaos in a Cold Thermoreceptor Model.

    PubMed

    Xu, Kesheng; Maidana, Jean P; Caviedes, Mauricio; Quero, Daniel; Aguirre, Pablo; Orio, Patricio

    2017-01-01

    In this article, we describe and analyze the chaotic behavior of a conductance-based neuronal bursting model. This is a model with a reduced number of variables, yet it retains biophysical plausibility. Inspired by the activity of cold thermoreceptors, the model contains a persistent Sodium current, a Calcium-activated Potassium current and a hyperpolarization-activated current (Ih) that drive a slow subthreshold oscillation. Driven by this oscillation, a fast subsystem (fast Sodium and Potassium currents) fires action potentials in a periodic fashion. Depending on the parameters, this model can generate a variety of firing patterns that includes bursting, regular tonic and polymodal firing. Here we show that the transitions between different firing patterns are often accompanied by a range of chaotic firing, as suggested by an irregular, non-periodic firing pattern. To confirm this, we measure the maximum Lyapunov exponent of the voltage trajectories, and the Lyapunov exponent and Lempel-Ziv's complexity of the ISI time series. The four-variable slow system (without spiking) also generates chaotic behavior, and bifurcation analysis shows that this is often originated by period doubling cascades. Either with or without spikes, chaos is no longer generated when the Ih is removed from the system. As the model is biologically plausible with biophysically meaningful parameters, we propose it as a useful tool to understand chaotic dynamics in neurons.

  20. Hyperpolarization-Activated Current Induces Period-Doubling Cascades and Chaos in a Cold Thermoreceptor Model

    PubMed Central

    Xu, Kesheng; Maidana, Jean P.; Caviedes, Mauricio; Quero, Daniel; Aguirre, Pablo; Orio, Patricio

    2017-01-01

    In this article, we describe and analyze the chaotic behavior of a conductance-based neuronal bursting model. This is a model with a reduced number of variables, yet it retains biophysical plausibility. Inspired by the activity of cold thermoreceptors, the model contains a persistent Sodium current, a Calcium-activated Potassium current and a hyperpolarization-activated current (Ih) that drive a slow subthreshold oscillation. Driven by this oscillation, a fast subsystem (fast Sodium and Potassium currents) fires action potentials in a periodic fashion. Depending on the parameters, this model can generate a variety of firing patterns that includes bursting, regular tonic and polymodal firing. Here we show that the transitions between different firing patterns are often accompanied by a range of chaotic firing, as suggested by an irregular, non-periodic firing pattern. To confirm this, we measure the maximum Lyapunov exponent of the voltage trajectories, and the Lyapunov exponent and Lempel-Ziv's complexity of the ISI time series. The four-variable slow system (without spiking) also generates chaotic behavior, and bifurcation analysis shows that this is often originated by period doubling cascades. Either with or without spikes, chaos is no longer generated when the Ih is removed from the system. As the model is biologically plausible with biophysically meaningful parameters, we propose it as a useful tool to understand chaotic dynamics in neurons. PMID:28344550

  1. Range-separated double-hybrid density-functional theory applied to periodic systems

    SciTech Connect

    Sansone, Giuseppe; Civalleri, Bartolomeo; Maschio, Lorenzo; Usvyat, Denis; Toulouse, Julien; Sharkas, Kamal

    2015-09-14

    Quantum chemistry methods exploiting density-functional approximations for short-range electron-electron interactions and second-order Møller-Plesset (MP2) perturbation theory for long-range electron-electron interactions have been implemented for periodic systems using Gaussian-type basis functions and the local correlation framework. The performance of these range-separated double hybrids has been benchmarked on a significant set of systems including rare-gas, molecular, ionic, and covalent crystals. The use of spin-component-scaled MP2 for the long-range part has been tested as well. The results show that the value of μ = 0.5 bohr{sup −1} for the range-separation parameter usually used for molecular systems is also a reasonable choice for solids. Overall, these range-separated double hybrids provide a good accuracy for binding energies using basis sets of moderate sizes such as cc-pVDZ and aug-cc-pVDZ.

  2. Fabrication and characterization of short-period double-layer cross-grating with holographic lithography

    NASA Astrophysics Data System (ADS)

    Lin, Cunbao; Yan, Shuhua; You, Fusheng

    2017-01-01

    A cross-grating with short period and double layer is designed, and a method combining holographic lithography and lithography-etch-lithography-etch is proposed to manufacture it. The scalar diffraction theory and the rigorous coupled wave analysis are employed to analyze the diffraction characteristics of the double-layer cross-grating (DLCG). It reveals that the efficiencies of the (±1,±1) orders possess perfect complementarity under normal incidence. The equivalent high efficiency for TE and TM polarization can be realized which means the high signal-to-noise ratio and fringe contrast can be simultaneously achieved for heterodyne grating interferometers (HGIs). Furthermore, a gold-coated DLCG with grating pitch of 2 μm and pattern area of 60 mm×60 mm etched on the quartz substrate is fabricated with the proposed method. The displacement resolution, measurement range and long-term stability can be reliably guaranteed for HGIs with this grating. The characteristics of the DLCG are also experimentally tested and compared with the theoretical analysis. Reasonable consistency is obtained and the capabilities of both the DLCG and the fabrication method are verified.

  3. Contact process on generalized Fibonacci chains: infinite-modulation criticality and double-log periodic oscillations.

    PubMed

    Barghathi, Hatem; Nozadze, David; Vojta, Thomas

    2014-01-01

    We study the nonequilibrium phase transition of the contact process with aperiodic transition rates using a real-space renormalization group as well as Monte Carlo simulations. The transition rates are modulated according to the generalized Fibonacci sequences defined by the inflation rules A → ABk and B → A. For k=1 and 2, the aperiodic fluctuations are irrelevant, and the nonequilibrium transition is in the clean directed percolation universality class. For k≥3, the aperiodic fluctuations are relevant. We develop a complete theory of the resulting unconventional "infinite-modulation" critical point, which is characterized by activated dynamical scaling. Moreover, observables such as the survival probability and the size of the active cloud display pronounced double-log periodic oscillations in time which reflect the discrete scale invariance of the aperiodic chains. We illustrate our theory by extensive numerical results, and we discuss relations to phase transitions in other quasiperiodic systems.

  4. Contact process on generalized Fibonacci chains: Infinite-modulation criticality and double-log periodic oscillations

    NASA Astrophysics Data System (ADS)

    Barghathi, Hatem; Nozadze, David; Vojta, Thomas

    2014-01-01

    We study the nonequilibrium phase transition of the contact process with aperiodic transition rates using a real-space renormalization group as well as Monte Carlo simulations. The transition rates are modulated according to the generalized Fibonacci sequences defined by the inflation rules A → ABk and B → A. For k =1 and 2, the aperiodic fluctuations are irrelevant, and the nonequilibrium transition is in the clean directed percolation universality class. For k ≥3, the aperiodic fluctuations are relevant. We develop a complete theory of the resulting unconventional "infinite-modulation" critical point, which is characterized by activated dynamical scaling. Moreover, observables such as the survival probability and the size of the active cloud display pronounced double-log periodic oscillations in time which reflect the discrete scale invariance of the aperiodic chains. We illustrate our theory by extensive numerical results, and we discuss relations to phase transitions in other quasiperiodic systems.

  5. Doppler tomography of the Double periodic variable HD 170582 at low and high stage

    NASA Astrophysics Data System (ADS)

    Mennickent, R. E.; Zharikov, S.; Cabezas, M.; Djurašević, G.

    2016-09-01

    HD 170582 is an interacting binary of the double periodic variable (DPV) type, showing ellipsoidal variability with a period of 16.87 d along with a long photometric cycle of 587 d. It was recently studied by Mennickent et al., who found a slightly evolved B-type star surrounded by a luminous accretion disc fed by a Roche lobe overflowing A-type giant. Here we extend their analysis presenting new spectroscopic data and studying the Balmer emission lines. We find orbitally modulated double-peak Hα and Hβ emissions whose strength also vary in the long term. In addition, Doppler maps of the emission lines reveal sites of enhanced line emission in the first and fourth velocity quadrants, the first one consistent with the position of one of the bright zones detected by the light-curve analysis. We find a difference between Doppler maps at high and low stage of the long cycle; evidence that the emission is optically thicker at high state in the stream-disc impact region, possibly reflecting a larger mass transfer rate. We compare the system parameters with a grid of synthetic binary evolutionary tracks and find the best-fitting model. The system is found to be semi-detached, in a conservative Case-B mass transfer stage, with age 7.68 × 107 yr and mass transfer rate 1.6 × 10-6 M⊙ yr-1. For five well-studied DPVs, the disc luminosity scales with the primary mass and is much larger than the theoretical accretion luminosity.

  6. Vocal fold and ventricular fold vibration in period-doubling phonation: physiological description and aerodynamic modeling.

    PubMed

    Bailly, Lucie; Henrich, Nathalie; Pelorson, Xavier

    2010-05-01

    Occurrences of period-doubling are found in human phonation, in particular for pathological and some singing phonations such as Sardinian A Tenore Bassu vocal performance. The combined vibration of the vocal folds and the ventricular folds has been observed during the production of such low pitch bass-type sound. The present study aims to characterize the physiological correlates of this acoustical production and to provide a better understanding of the physical interaction between ventricular fold vibration and vocal fold self-sustained oscillation. The vibratory properties of the vocal folds and the ventricular folds during phonation produced by a professional singer are analyzed by means of acoustical and electroglottographic signals and by synchronized glottal images obtained by high-speed cinematography. The periodic variation in glottal cycle duration and the effect of ventricular fold closing on glottal closing time are demonstrated. Using the detected glottal and ventricular areas, the aerodynamic behavior of the laryngeal system is simulated using a simplified physical modeling previously validated in vitro using a larynx replica. An estimate of the ventricular aperture extracted from the in vivo data allows a theoretical prediction of the glottal aperture. The in vivo measurements of the glottal aperture are then compared to the simulated estimations.

  7. Prediction of Period-Doubling Bifurcation Based on Dynamic Recognition and Its Application to Power Systems

    NASA Astrophysics Data System (ADS)

    Chen, Danfeng; Wang, Cong

    In this paper, a bifurcation prediction approach is proposed based on dynamic recognition and further applied to predict the period-doubling bifurcation (PDB) of power systems. Firstly, modeling of the internal dynamics of nonlinear systems is obtained through deterministic learning (DL), and the modeling results are applied for constructing the dynamic training pattern database. Specifically, training patterns are chosen according to the hierarchical structured knowledge representation based on the qualitative property of dynamical systems, which is capable of arranging the dynamical models into a specific order in the pattern database. Then, a dynamic recognition-based bifurcation prediction approach is suggested. As a result, perturbations implying PDB on the testing patterns can be predicted through the minimum dynamic error between the training patterns and testing patterns by recalling the knowledge restored in the pattern database. Finally, the second-order single-machine to infinite bus power system model is introduced to check the effectiveness of this prediction approach, which implies PDB under small periodic parameter perturbations. The key point that determines the prediction effect mainly lies in two methods: (1) accurate approximation of the unknown system dynamics through DL guarantees the feasibility of the prediction process; (2) the qualitative property of PDB and the generalization ability of DL algorithm ensure the validity of the selected training patterns. Simulations are included to illustrate the effectiveness of the proposed approach.

  8. Period Evolution of Double White Dwarf Binaries Under the Influence of Gravitational Wave Emissions

    NASA Astrophysics Data System (ADS)

    Martens, Kylee; Benacquista, Matt; Belczynski, Chris

    2016-03-01

    Compact objects, such as Double White Dwarf (DWD) binaries, are the most populous producers of gravitational waves (GW) at low frequencies. The gravitational radiation (GR) emitted from the Galactic DWD binary population will create an unresolvable signal known as the confusion noise-limit (CNL) in the space-based evolved Laser Interferometer Space Antenna (eLISA). It is predicted that many thousand DWD binary signals will rise above the CNL and create resolvable GW signals. In previous work, Heather Johnson, from the University of Texas-Austin, produced ~61 million DWD systems using the binary population features in the StarTrack population synthesis code created by Chris Belczynski. We have created an evolutionary code that continues the period evolution of the DWD binaries under the effects of GR. Our present model only accounts for detached binary systems, but we are working on incorporating more features. Current period evolution models often extrapolate data based on smaller binary populations, however our model will utilize ~61 million binary systems in order to avoid inaccuracies.We then use two standard cylindrical density distributions to populate a galaxy with the evolved systems. We also discuss correlations between the progenitor binaries and the eLISA sources.

  9. Refraction index sensor based on phase resonances in a subwavelength structure with double period.

    PubMed

    Skigin, Diana C; Lester, Marcelo

    2016-10-01

    In this paper, we numerically demonstrate a refraction index sensor based on phase resonance excitation in a subwavelength-slit structure with a double period. The sensor consists of a metal layer with subwavelength slots arranged in a bi-periodic form, separated from a high refraction index medium. Between the metallic structure and the incident medium, a dielectric waveguide is formed whose refraction index is going to be determined. Variations in the refraction index of the waveguide are detected as shifts in the peaks of transmitted intensity originated by resonant modes supported by the compound metallic structure. At normal incidence, the spectral position of these resonant peaks exhibits a linear or a quadratic dependence with the refraction index, which permits us to obtain the unknown refraction index value with a high precision for a wide range of wavelengths. Since the operating principle of the sensor is due to the morphological resonances of the slits' structure, this device can be scaled to operate in different wavelength ranges while keeping similar characteristics.

  10. Are B[e] Stars of FS CMa-Type Related to Double Periodic Variables?

    NASA Astrophysics Data System (ADS)

    Mennickent, R.

    2017-02-01

    We have recently examined the relation between two types of intermediate-mass interacting binaries; the strongly interacting W Serpentis stars and the enigmatic double periodic variables (DPVs). In both cases, the analysis of WISE and 2MASS photometry indicates the presence of color excess that might be attributed to circumstellar matter. This is supported by the presence of Balmer emission lines and by the light curve models. However, W Serpentis stars are sometimes less massive than DPVs and usually show changes in their orbital periods. In this contribution, a third type of object has been examined, the B[e] stars of the FS CMa type, of which 30% have been found to be binaries. They are located in a similar region of the HR diagram to DPVs, but show stronger emission lines and larger color excess. Since theoretical models indicate that all these close binaries pass by epochs of strong mass loss, at least some of the FS CMa systems might be precursors of DPVs, closer to the stage of mass ratio reversal. Fundamental stellar parameters for FS CMa stars are still scarce; more studies are needed, especially spectroscopic ones, to clarify this possibility.

  11. Towards a quantitative understanding of period-doubling wrinkling patterns occurring in film/substrate bilayer systems

    PubMed Central

    Zhao, Yan; Cao, Yanping; Hong, Wei; Wadee, M. Khurram; Feng, Xi-Qiao

    2015-01-01

    Compression of a stiff film on a soft substrate may lead to surface wrinkling when the compressive strain reaches a critical value. Further compression may cause a wrinkling–folding transition, and the sinusoidal wrinkling mode can then give way to a period-doubling bifurcation. The onset of the primary bifurcation has been well understood, but a quantitative understanding of the secondary bifurcation remains elusive. Our theoretical analysis of the branching of surface patterns reveals that the wrinkling–folding transition depends on the wrinkling strain and the prestrain in the substrate. A characteristic strain in the substrate is adopted to determine the correlation among the critical strain of the period-doubling mode, the wrinkling strain and the prestrain in an explicit form. A careful examination of the total potential energy of the system reveals that beyond the critical strain of period-doubling, the sinusoidal wrinkling mode has a higher potential energy in comparison with the period-doubling mode. The critical strain of the period-doubling mode strongly depends on the deformation state of the hyperelastic solid, indicating that the nonlinear deformation behaviour of the substrate plays a key role here. The results reported here on the one hand provide a quantitative understanding of the wrinkling–folding transition observed in natural and synthetic material systems and on the other hand pave the way to control the wrinkling mode transition by regulating the strain state in the substrate. PMID:25568620

  12. Sound transmission through a double panel structure periodically coupled with vibration insulators

    NASA Astrophysics Data System (ADS)

    Legault, Julien; Atalla, Noureddine

    2010-07-01

    In this paper, sound transmission through an aircraft sidewall representative double panel structure is investigated theoretically and parametric and validation studies are conducted. The studied configuration is composed of a trim panel (receiver side panel) attached to a ribbed skin panel (source side panel) with periodically spaced resilient mounts. The structure is considered infinite in order to use space harmonic expansion. The partition is also assumed planar for simplicity. The model allows for a 3D incident field and the panels can be metallic and/or composite. A four-pole formulation is employed for modeling of the mounts and the absorption provided by the fiberglass that fills the cavity between the leaves is addressed with an equivalent fluid model. The investigation of mount stiffness, damping and spacing show that properly designed mounts can increase the TL significantly (up to 20 dB of difference between rigid and resilient mounts). However, they can create undesirable resonances resulting from their interaction with the panels. The influence of cavity absorption is also studied and results illustrate the fact that it is not worth investing in a highly absorbent fiber if the structure-borne transmission path is not adequately insulated, and likewise that it is not worth investing in highly resilient mounts without sufficient cavity absorption. Moreover, the investigation of panel damping confirms that when structure-borne transmission is present, raising skin damping can increase the TL even below coincidence, but that on average, greater improvements are achieved by raising trim damping. Finally, comparison between the periodic model and finite element simulations for structure-borne transmission shows that the average level of transmitted energy is well reproduced with the periodic approach. However, the modes are only captured approximately due to the assumption of an infinite structure.

  13. Lamb wave band gaps in one-dimensional radial phononic crystal plates with periodic double-sided corrugations

    NASA Astrophysics Data System (ADS)

    Li, Yinggang; Chen, Tianning; Wang, Xiaopeng; Li, Suobin

    2015-11-01

    In this paper, we present the theoretical investigation of Lamb wave propagation in one-dimensional radial phononic crystal (RPC) plates with periodic double-sided corrugations. The dispersion relations, the power transmission spectra, and the displacement fields of the eigenmodes are studied by using the finite element method based on two-dimensional axial symmetry models in cylindrical coordinates. Numerical results show that the proposed RPC plates with periodic double-sided corrugations can yield several band gaps with a variable bandwidth for Lamb waves. The formation mechanism of band gaps in the double-sided RPC plates is attributed to the coupling between the Lamb modes and the in-phase and out-phases resonant eigenmodes of the double-sided corrugations. We investigate the evolution of band gaps in the double-sided RPC plates with the corrugation heights on both sides arranged from an asymmetrical distribution to a symmetrical distribution gradually. Significantly, with the introduction of symmetric double-sided corrugations, the antisymmetric Lamb mode is suppressed by the in-phase resonant eigenmodes of the double-sided corrugations, resulting in the disappearance of the lowest band gap. Furthermore, the effects of the geometrical parameters on the band gaps are further explored numerically.

  14. Principle of non-interaction of waves

    NASA Astrophysics Data System (ADS)

    Roychoudhuri, Chandrasekhar

    2010-07-01

    Non-interaction of waves (NIW) in the linear domain is an unappreciated but general principle of nature. Explicit recognition of this NIW-principle will add renewed momentum to the progress of fundamental physics and related technologies like spectrometry, coherence, polarizations, laser mode-locking, etc. This principle helps us appreciate that the mathematical correctness of a theorem and its capability to predict certain groups of measured data, do not necessarily imply that the theorem is always capable of mapping real interaction processes in nature. The time-frequency Fourier theorem (TF-FT) is an example since superposed light beams, by themselves, cannot reorganize or sum their energies. Quantum Mechanics (QM) correctly discovered that photons (light beams) are non-interacting bosons. Yet, to accommodate (i) the classical belief that light beams interfere (interact) by themselves, and (ii) Einstein's heuristic hypothesis that discrete packets of energy emitted by molecules travel as indivisible quanta (contradicting spontaneous diffractive spreading), QM has been forced to hypothesize that a photon interferes only with itself. In reality, it is the quantized detecting material media that make the superposition effects become manifest as their physical transformations, from bound electrons to released photoelectrons, after absorbing energy from all the beams due to induced simultaneous stimulations by the beams.

  15. Defect-induced period-doubling perturbation on Si(111)4x1-In

    NASA Astrophysics Data System (ADS)

    Lee, Geunseop; Yu, Sang-Yong

    2005-03-01

    We investigated using STM and LEED the influence of defects at room temperature on the quasi-one dimensional Si(111)4x1-In surface which changes into a 4x2 (or 8x2) phase below 120 K. Various types of defects (vacancy, step edge, and phase shift boundary) and adatoms (H2, O2, and In) were found to induce local period-doubling (x2) modulations at room temperature. The x2 modulated region shows metallic I-V characteristics, having little change from that of the defect-free 4x1 region despite the difference in topology in the image. Therefore, the defect-induced x2 modulation is discriminated from the low-temperature phase that was reported to be insulating. Using the first-principles calculations, the x2 modulation is found to originate from a different 4x2 structure of the clean surface that is stabilized by the presence of defects. The nature of the phase transition of this In/Si(111) system and the influence of the defects will be discussed.

  16. Efficient blue light generation using periodically poled stoichiometric lithium tantalate via resonant frequency doubling

    NASA Astrophysics Data System (ADS)

    Khademian, Ali; Jadhav, Shilpa; Shiner, David

    2014-05-01

    Convenient high power blue diode lasers with single frequency operation are still under developments and are not as well developed and cost effective as IR laser sources. Harmonic generation of IR lasers provide a viable alternative source of blue and UV light. Magnesium oxide doped periodically poled Stoichiometric Lithium Tantalate (PPMgO:SLT) has been reported to have the lowest blue, IR and blue induced IR absorption (BLIIRA) among ferroelectric crystals such as Lithium Niobate (PPLN) and Potassium Titanyl Phosphate (PPKTP). All these properties, along with higher thermal conductivity, make this crystal an excellent candidate for efficient blue light generation using second harmonic generation (SHG) in a resonant buildup cavity. Efficient resonant doubling is very sensitive to various cavity and crystal loss mechanisms. Recently we obtained 400 mW of blue light at 486 nm with net conversion efficiency of 77% using a 515 mW fiber grating stabilized IR source. Sources of conversion loss have been identified and evaluated with various methods in our investigation. These include reflection, scattering, absorption, and polarization rotation of IR light in the crystal, as well as mode mismatching and spherical aberration due to focusing lenses. The locking and electronic control functions of the cavity are automated using an internally mounted single chip microcontroller with embedded DSP (digital signal processor). Work is supported by NSF grant.

  17. Contact process on generalized Fibonacci chains: infinite-modulation criticality and double-log periodic oscillations

    NASA Astrophysics Data System (ADS)

    Barghathi, Hatem; Nozadze, David; Vojta, Thomas

    2014-03-01

    We study the nonequilibrium phase transition of the contact process with aperiodic transition rates using a real-space renormalization group as well as Monte-Carlo simulations. The transition rates are modulated according to the generalized Fibonacci sequences defined by the inflation rules A --> ABk and B --> A. For k = 1 and 2, the aperiodic fluctuations are irrelevant, and the nonequilibrium transition is in the clean directed percolation universality class. For k >= 3 , the aperiodic fluctuations are relevant. We develop a complete theory of the resulting unconventional ``infinite-modulation'' critical point which is characterized by activated dynamical scaling. Moreover, observables such as the survival probability and the size of the active cloud display pronounced double-log periodic oscillations in time which reflect the discrete scale invariance of the aperiodic chains. We illustrate our theory by extensive numerical results, and we discuss relations to phase transitions in other quasiperiodic systems. This work has been supported in part by the NSF under grants no. DMR-0906566, DMR-1205803, and PHYS-1066293.

  18. Analytical investigation of the spectra of coupled polaritons on double periodic metal surfaces

    NASA Astrophysics Data System (ADS)

    Kats, Alexandre V.; Nikitin, Alexey Y.

    2003-11-01

    The results of analytical and numerical investigation of the surface plasmon-polaritons (SPP)dispersion relation on double periodical high reflecting surfaces (two-dimensional photonic crystals)are presented. The formalism is developed for gratings formed by the modulation of either optical properties or the relief of the medium. The coupling between SPP existing on the non-modulated boundary leads to the mini-gaps arising at the Brillouin-zone boundaries. The dependence of the dispersion relation upon the parameters of the problem (amplitude of the modulation, an angle between the elementary translations,etc.) is calculated for different types of symmetry that corresponds to the coupling from two to six polaritons. The specific values of the parameters corresponding to existence of the standing polariton modes, vanishing of the polariton group velocity are found. The distribution of surface charges for corresponding polariton modes is presented. The ratio between the polariton dispersion relation and the light diffraction under the condition of the polariton excitation is discussed as well. The results obtained can be used to design the two-dimensional photonic crystals with specific and given properties.

  19. Double-crystal monochromator for a PF 60-period soft x-ray undulator (abstract)

    SciTech Connect

    Ishikawa, T.; Maezawa, H.; Nomura, M.; Ando, M.

    1989-07-01

    Since undulator light is sharply collimated itself, it can be effectively monochromatized by a perfect crystal. An x-ray double-crystal monochromator with a fixed exit has been designed and built for the use of undulator light from a 60-period undulator at Photon Factory (beamline 2A). Available Bragg angle ranges from 7/degree/ to 80/degree/. Angle scan is made by means of a goniometer outside the vacuum chamber, with the finest step of 0.1 arcsec. Magnetic fluid is used as the vacuum seal of the feedthrough. The fixed exit beam position is kept by translating the second crystal along the two mechanical guides: one for normal and the other for parallel to the crystal surface. Adjustment of the parallelity of two crystals is made manually with flexible wires. Since a total power in the central coherent portion which is limited by a 1/times/1-mm/sup 2/ slit is not so much, a stable operation is possible without cooling the crystal. Currently, InSb (111) reflection is used. The diffracting planes of the first cyrstal is 1/degree/ off from the surface and the second is the symmetric reflection. At its fifth harmonics, brilliant undulator light of approximately 10/sup 12/ photons/s mm/sup 2/ with 1-eV energy resolution is available (/ital E/=2 keV).

  20. A note on obtaining an approximate value for the period of a periodic solution of x-double prime = -V prime /x/. [orbit equations

    NASA Technical Reports Server (NTRS)

    Lass, H.; Georgevic, R. M.

    1978-01-01

    The first integral of x-double prime = - V prime (x) yields an integral for the period of a periodic solution, if such exists. In general, this integral cannot be evaluated. By means of an approximate solution along with the minimization of a mean-square error, one can obtain an approximate value for the period in terms of the amplitude of the motion. The calculated period agrees very well with the period obtained by means of numerical integration for the case of orbit-orbit resonance involving the motion of two satellites of a planet. The same method is applied to obtain an alternative derivation of the first Krylov-Bogoliuboff averaging method in nonlinear mechanics.

  1. Period doubling cascades of prey-predator model with nonlinear harvesting and control of over exploitation through taxation

    NASA Astrophysics Data System (ADS)

    Gupta, R. P.; Banerjee, Malay; Chandra, Peeyush

    2014-07-01

    The present study investigates a prey predator type model for conservation of ecological resources through taxation with nonlinear harvesting. The model uses the harvesting function as proposed by Agnew (1979) [1] which accounts for the handling time of the catch and also the competition between standard vessels being utilized for harvesting of resources. In this paper we consider a three dimensional dynamic effort prey-predator model with Holling type-II functional response. The conditions for uniform persistence of the model have been derived. The existence and stability of bifurcating periodic solution through Hopf bifurcation have been examined for a particular set of parameter value. Using numerical examples it is shown that the system admits periodic, quasi-periodic and chaotic solutions. It is observed that the system exhibits periodic doubling route to chaos with respect to tax. Many forms of complexities such as chaotic bands (including periodic windows, period-doubling bifurcations, period-halving bifurcations and attractor crisis) and chaotic attractors have been observed. Sensitivity analysis is carried out and it is observed that the solutions are highly dependent to the initial conditions. Pontryagin's Maximum Principle has been used to obtain optimal tax policy to maximize the monetary social benefit as well as conservation of the ecosystem.

  2. Quantum states of charge carriers and longitudinal conductivity in double periodic n-type semiconductor lattice structures in electric field

    SciTech Connect

    Perov, A. A. Penyagin, I. V.

    2015-07-15

    Quantum states of charge carriers in double periodic semiconductor superlattices of n-type quantum dots with Rashba spin–orbit coupling in an electron gas have been calculated in the one-electron approximation in the presence of mutually perpendicular electric and magnetic fields. For these structures in weak constant electric field, the solution to the quasi-classical kinetic Boltzmann equation shows that the states of carriers in magnetic Landau minibands with negative differential conductivity are possible.

  3. Revisiting CoRoT RR Lyrae stars: detection of period doubling and temporal variation of additional frequencies

    NASA Astrophysics Data System (ADS)

    Szabó, R.; Benkő, J. M.; Paparó, M.; Chapellier, E.; Poretti, E.; Baglin, A.; Weiss, W. W.; Kolenberg, K.; Guggenberger, E.; Le Borgne, J.-F.

    2014-10-01

    Context. High-precision, space-based photometric missions like CoRoT and Kepler have revealed new and surprising phenomena in classical variable stars. Such discoveries were the period doubling in RR Lyrae stars and the frequent occurrence of additional periodicities some of which can be explained by radial overtone modes, but others are discordant with the radial eigenfrequency spectrum. Aims: We search for signs of period doubling in CoRoT RR Lyrae stars. The occurrence of this dynamical effect in modulated RR Lyrae stars might help us to gain more information about the mysterious Blazhko effect. The temporal variability of the additional frequencies in representatives of all subtypes of RR Lyrae stars is also investigated. Methods: We preprocess CoRoT light curves by applying trend and jump correction and outlier removal. Standard Fourier technique is used to analyze the frequency content of our targets and follow the time-dependent phenomena. Results: The most comprehensive collection of CoRoT RR Lyrae stars, including new discoveries is presented and analyzed. We found alternating maxima and in some cases half-integer frequencies in four CoRoT Blazhko RR Lyrae stars, as clear signs of the presence of period doubling. This reinforces that period doubling is an important ingredient for understanding the Blazhko effect - a premise we derived previously from the Kepler RR Lyrae sample. As expected, period doubling is detectable only for short time intervals in most modulated RRab stars. Our results show that the temporal variability of the additional frequencies in all RR Lyrae subtypes is ubiquitous. The ephemeral nature and the highly variable amplitude of these variations suggest a complex underlying dynamics of and an intricate interplay between radial and possibly nonradial modes in RR Lyrae stars. The omnipresence of additional modes in all types of RR Lyrae - except in non-modulated RRab stars - implies that asteroseismology of these objects should be

  4. Peculiar double-periodic pulsation in RR Lyrae stars of the OGLE collection - II. Short-period stars with a dominant radial fundamental mode

    NASA Astrophysics Data System (ADS)

    Prudil, Z.; Smolec, R.; Skarka, M.; Netzel, H.

    2017-03-01

    We report the discovery of a new group of double-periodic stars in the OGLE Galactic bulge photometry. In 38 stars identified as fundamental-mode RR Lyrae and four classified as first-overtone RR Lyrae, we detected an additional shorter periodicity. The periods of the dominant variability in the newly discovered group are 0.28 < PD < 0.41 d. Period ratios (0.68-0.72) are smaller than the period ratios of the Galactic bulge RRd stars. The typical amplitude ratio (of the additional to the dominant periodicity) is 20 per cent for the stars identified as fundamental-mode RR Lyrae and 50 per cent for stars classified as first-overtone RR Lyrae. 10 stars from our sample exhibit equidistant peaks in the frequency spectrum, which suggests the Blazhko-type modulation of the main pulsation frequency and/or additional periodicity. The Fourier coefficients R21 and R31 are some of the lowest among fundamental-mode RR Lyrae stars, but among the highest for the first-overtone pulsators. For the phase Fourier coefficients φ21 and φ31, our stars lie between RRab and RRc stars. The stars discussed were compared with radial linear pulsation models. Their position in the Petersen diagram cannot be reproduced by assuming that two radial modes are excited and their physical parameters are like those characteristic of RR Lyrae stars. The non-radial-mode scenario also faces difficulties. We conclude that the dominant variability is most likely due to pulsation in the radial fundamental mode, which applies to stars classified as first-overtone mode pulsators. At this point, we cannot explain the nature of the additional periodicity. Even more, the classification of the stars as RR Lyrae should be treated as tentative.

  5. Model simulation for periodic double-peaked outbursts in blazar OJ 287: binary black hole plus lighthouse effect

    NASA Astrophysics Data System (ADS)

    Qian, Shan-Jie

    2015-05-01

    The mechanism of formation for double-peaked optical outbursts observed in blazar OJ 287 is studied. It is shown that they could be explained in terms of a lighthouse effect for superluminal optical knots ejected from the center of the galaxy that move along helical magnetic fields. It is assumed that the orbital motion of the secondary black hole in the supermassive binary black hole system induces the 12-year quasi-periodicity in major optical outbursts by the interaction with the disk around the primary black hole. This interaction between the secondary black hole and the disk of the primary black hole (e.g. tidal effects or magnetic coupling) excites or injects plasmons (or relativistic plasmas plus magnetic field) into the jet which form superluminal knots. These knots are assumed to move along helical magnetic field lines to produce the optical double-peaked outbursts by the lighthouse effect. The four double-peaked outbursts observed in 1972, 1983, 1995 and 2005 are simulated using this model. It is shown that such lighthouse models are quite plausible and feasible for fitting the double-flaring behavior of the outbursts. The main requirement may be that in OJ 287 there exists a rather long (~40-60 pc) highly collimated zone, where the lighthouse effect occurs.

  6. Laser-induced periodic surface structures on zinc oxide crystals upon two-colour femtosecond double-pulse irradiation

    NASA Astrophysics Data System (ADS)

    Höhm, S.; Rosenfeld, A.; Krüger, J.; Bonse, J.

    2017-03-01

    In order to study the temporally distributed energy deposition in the formation of laser-induced periodic surface structures (LIPSS) on single-crystalline zinc oxide (ZnO), two-colour double-fs-pulse experiments were performed. Parallel or cross-polarised double-pulse sequences at 400 and 800 nm wavelength were generated by a Mach–Zehnder interferometer, exhibiting inter-pulse delays up to a few picoseconds between the sub-ablation 50-fs-pulses. Twenty two-colour double-pulse sequences were collinearly focused by a spherical mirror to the sample surface. The resulting LIPSS periods and areas were analysed by scanning electron microscopy. The delay-dependence of these LIPSS characteristics shows a dissimilar behaviour when compared to the semiconductor silicon, the dielectric fused silica, or the metal titanium. A wavelength-dependent plasmonic mechanism is proposed to explain the delay-dependence of the LIPSS on ZnO when considering multi-photon excitation processes. Our results support the involvement of nonlinear processes for temporally overlapping pulses. These experiments extend previous two-colour studies on the indirect semiconductor silicon towards the direct wide band-gap semiconductor ZnO and further manifest the relevance of the ultrafast energy deposition for LIPSS formation.

  7. Wavelets, period-doubling, and time-frequency localization with application to organization of convection over the tropical western Pacific

    NASA Technical Reports Server (NTRS)

    Weng, Hengyi; Lau, K.-M.

    1994-01-01

    In this paper, preliminary results in using orthogonal and continuous wavelet transform (WT) to identify period doubling and time-frequency localization in both synthetic and real data are presented. First, the Haar WT is applied to synthetic time series derived from a simple nonlinear dynamical system- a first-order quadratic difference equation. Second, the complex Morlet WT is used to study the time-frequency localization of tropical convection based on a high-resolution Japanese Geostationary Meteorological Satellite infrared (IR) radiance dataset. The Haar WT of the synthetic time series indicates the presence and distinct separation of multiple frequencies in a period-doubling sequence. The period-doubling process generates a multiplicity of intermediate frequencies, which are manifested in the nonuniformity in time with respect to the phase of oscillations in the lower frequencies. Wavelet transform also enables the detection of extremely weak signals in high-order subharmonics resulting from the period-doubling bifurcations. These signals are either undetected or considered statistically insignificant by traditional Fourier analysis. The Morlet WT of the IR radiance dataset indicates the presence of multiple timescales, which are localized in both frequency and time. There are two regimes in the variation of IR radiance, corresponding to the wet and dry periods. Multiple timescales, ranging from semidiurnal, diurnal, synoptic, to intraseasonal with embedding structures, are active in the wet regime. In particular, synoptic variability is more prominent during the wet phase of an intensive intraseasonal cycle. These are not only consistent with, but also show more details than, previous findings by using other techniques. The phase-locking relationships among the oscillations with different time-scales suggest that both synoptic and intraseasonal variations may be mixed oscillations due to the interaction of self-excited oscillations in the tropical

  8. Periodization

    PubMed Central

    Lorenz, Daniel S.; Reiman, Michael P.; Walker, John C.

    2010-01-01

    Background: Clinicians are constantly faced with the challenge of designing training programs for injured and noninjured athletes that maximize healing and optimize performance. Periodization is a concept of systematic progression—that is, resistance training programs that follow predictable patterns of change in training variables. The strength training literature is abundant with studies comparing periodization schemes on uninjured, trained, and untrained athletes. The rehabilitation literature, however, is scarce with information about how to optimally design resistance training programs based on periodization principles for injured athletes. The purpose of this review is to discuss relevant training variables and methods of periodization, as well as periodization program outcomes. A secondary purpose is to provide an anecdotal framework regarding implementation of periodization principles into rehabilitation programs. Evidence Acquisition: A Medline search from 1979 to 2009 was implemented with the keywords periodization, strength training, rehabilitation, endurance, power, hypertrophy, and resistance training with the Boolean term AND in all possible combinations in the English language. Each author also undertook independent hand searching of article references used in this review. Results: Based on the studies researched, periodized strength training regimens demonstrate improved outcomes as compared to nonperiodized programs. Conclusions: Despite the evidence in the strength training literature supporting periodization programs, there is a considerable lack of data in the rehabilitation literature about program design and successful implementation of periodization into rehabilitation programs. PMID:23015982

  9. Evidence of chaotic pattern in solar flux through a reproducible sequence of period-doubling-type bifurcations

    NASA Technical Reports Server (NTRS)

    Ashrafi, S.; Roszman, L.

    1991-01-01

    Presented here is a preliminary study of the limits to solar flux intensity prediction, and of whether the general lack of predictability in the solar flux arises from the nonlinear chaotic nature of the Sun's physical activity. Statistical analysis of a chaotic signal can extract only its most gross features, and detailed physical models fail, since even the simplest equations of motion for a nonlinear system can exhibit chaotic behavior. A recent theory by Feigenbaum suggests that nonlinear systems that can be led into chaotic behavior through a sequence of period-doubling bifurcations will exhibit a universal behavior. As the control parameter is increased, the bifurcation points occur in such a way that a proper ratio of these will approach the universal Feigenbaum number. Experimental evidence supporting the applicability of the Feigenbaum scenario to solar flux data is sparse. However, given the hypothesis that the Sun's convection zones are similar to a Rayleigh-Bernard mechanism, we can learn a great deal from the remarkable agreement observed between the prediction by theory (period doubling - a universal route to chaos) and the amplitude decrease of the signal's regular subharmonics. The authors show that period-doubling-type bifurcation is a possible route to a chaotic pattern of solar flux that is distinguishable from the logarithm of its power spectral density. This conclusion is the first positive step toward a reformulation of solar flux by a nonlinear chaotic approach. The ultimate goal of this research is to be able to predict an estimate of the upper and lower bounds for solar flux within its predictable zones. Naturally, it is an important task to identify the time horizons beyond which predictability becomes incompatible with computability.

  10. Evidence of chaotic pattern in solar flux through a reproducible sequence of period-doubling-type bifurcations

    NASA Technical Reports Server (NTRS)

    Ashrafi, S.; Roszman, L.

    1991-01-01

    A preliminary study of the limits to solar flux intensity prediction, and of whether the general lack of predictability in the solar flux arises from the nonlinear chaotic nature of the Sun's physical activity is presented. Statistical analysis of a chaotic signal can extract only its most gross features, and detailed physical models fail, since even the simplest equations of motion for a nonlinear system can exhibit chaotic behavior. A recent theory by Feigenbaum suggests that nonlinear systems that can be led into chaotic behavior through a sequence of period-doubling bifurcations will exhibit a universal behavior. As the control parameter is increased, the bifurcation points occur in such a way that a proper ratio of these will approach the universal Feigenbaum number. Experimental evidence supporting the applicability of the Feigenbaum scenario to solar flux data is sparse. However, given the hypothesis that the Sun's convection zones are similar to a Rayleigh-Bernard mechanism, we can learn a great deal from the remarkable agreement observed between the prediction by theory (period doubling - a universal route to chaos) and the amplitude decrease of the signal's regular subharmonics. It is shown that period-doubling-type bifurcation is a possible route to a chaotic pattern of solar flux that is distinguishable from the logarithm of its power spectral density. This conclusion is the first positive step toward a reformulation of solar flux by a nonlinear chaotic approach. The ultimate goal of this research is to be able to predict an estimate of the upper and lower bounds for solar flux within its predictable zones. Naturally, it is an important task to identify the time horizons beyond which predictability becomes incompatible with computability.

  11. Hole mobilities of periodic models of DNA double helices in the nucleosomes at different temperatures

    NASA Astrophysics Data System (ADS)

    Bende, Attila; Bogár, Ferenc; Ladik, János

    2013-04-01

    Using the Hartree-Fock crystal orbital method band structures of poly(G˜-C˜) and poly(A˜-T˜) were calculated (G˜, etc. means a nucleotide) including water molecules and Na+ ions. Due to the close packing of DNA in the ribosomes the motion of the double helix and the water molecules around it are strongly restricted, therefore the band picture can be used. The mobilities were calculated from the highest filled bands. The hole mobilities increase with decreasing temperatures. They are of the same order of magnitude as those of poly(A˜) and poly(T˜). For poly(G˜) the result is ˜5 times larger than in the poly(G˜-C˜) case.

  12. Effects of gas periodic stimulation on key enzyme activity in gas double-dynamic solid state fermentation (GDD-SSF).

    PubMed

    Chen, Hongzhang; Shao, Meixue; Li, Hongqiang

    2014-03-05

    The heat and mass transfer have been proved to be the important factors in air pressure pulsation for cellulase production. However, as process of enzyme secretion, the cellulase formation has not been studied in the view of microorganism metabolism and metabolic key enzyme activity under air pressure pulsation condition. Two fermentation methods in ATPase activity, cellulase productivity, weight lose rate and membrane permeability were systematically compared. Results indicated that gas double-dynamic solid state fermentation had no obviously effect on cell membrane permeability. However, the relation between ATPase activity and weight loss rate was linearly dependent with r=0.9784. Meanwhile, the results also implied that gas periodic stimulation had apparently strengthened microbial metabolism through increasing ATPase activity during gas double-dynamic solid state fermentation, resulting in motivating the production of cellulase by Trichoderma reesei YG3. Therefore, the increase of ATPase activity would be another crucial factor to strengthen fermentation process for cellulase production under gas double-dynamic solid state fermentation.

  13. Building dynamical models from data and prior knowledge: The case of the first period-doubling bifurcation

    NASA Astrophysics Data System (ADS)

    Aguirre, Luis Antonio; Furtado, Edgar Campos

    2007-10-01

    This paper reviews some aspects of nonlinear model building from data with (gray box) and without (black box) prior knowledge. The model class is very important because it determines two aspects of the final model, namely (i) the type of nonlinearity that can be accurately approximated and (ii) the type of prior knowledge that can be taken into account. Such features are usually in conflict when it comes to choosing the model class. The problem of model structure selection is also reviewed. It is argued that such a problem is philosophically different depending on the model class and it is suggested that the choice of model class should be performed based on the type of a priori available. A procedure is proposed to build polynomial models from data on a Poincaré section and prior knowledge about the first period-doubling bifurcation, for which the normal form is also polynomial. The final models approximate dynamical data in a least-squares sense and, by design, present the first period-doubling bifurcation at a specified value of parameters. The procedure is illustrated by means of simulated examples.

  14. Fabrication of spatially periodic double roughness structures by directional viscous fingering and spinodal dewetting for water-repellent surfaces.

    PubMed

    Kuroda, Akihiro; Ishihara, Tsukasa; Takeshige, Hikari; Asakura, Kouichi

    2008-01-31

    Water-repellent and self-cleaning properties of lotus leaves are considered to be due to its double roughness structure, protrusion structure (approximately 20 microm) and hairy structure (0.2-1.0 microm). In this study, attempts to fabricate a spatially periodic double roughness structure by two far-from-equilibrium self-organization phenomena, a directional viscous fingering and a spinodal dewetting, were made. A mixture of an octylsilyl titanium dioxide particle having an average diameter of 35 nm suspended in volatile silicone, decamethyl cyclopentasiloxane, and octyl p-methoxycinnamate was spread on a glass plate by dragging an applicator across the top. Formation of a stripe pattern parallel to the direction of dragging, called directional viscous fingering, was sometimes observed. Influences of spreading conditions on the pattern formation were analyzed. In addition, attempts were made to apply the stripe pattern formation to the preparation of a water repellent surface. We have succeeded in preparing a highly water-repellent surface by immersing a glass plate, on which a spatially periodic stripe pattern having a characteristic wavelength of 200-700 microm was formed, in water, after the completion of evaporation of decamethyl cyclopentasiloxane. In this case, dewetting patterns having a characteristic wavelength at around 5 microm were formed at the bottom part of the stripe patterns. Neither the surface on which only the mesoscopic spatially periodic stripe pattern was formed nor the one on which only the microscopic dewetting pattern was formed showed high water-repellent properties, indicating that the coexistence of the two different scales of patterns increased the water-repellent properties of the hydrophobic surface.

  15. Recurrence of Great Earthquakes: Evidence of Double Periodicity Along the Cascadia Subduction Zone

    NASA Astrophysics Data System (ADS)

    Jurney, C.

    2002-12-01

    Since the recognition that the Cascadia subduction zone in the US Pacific Northwest has produced large magnitude earthquakes in the past seven thousand years there has been considerable discussion centered on the dates and intervals between the earthquakes. Accurate information about the intervals between events improves the estimated date and magnitude of the next great earthquake and increases our ability to assess the potential level of risk to the residents and structures of the Cascadia margin. The penultimate event occurred about 1000 years ago but relatively little organic material has been dated. In this study, organic material collected from buried soils along the banks of the Lewis and Clark River near Astoria, Oregon yielded high precision radiocarbon dates that better constrain the dates of the penultimate and the fourth event. The peaty horizon of soil 2, marking the penultimate event, yielded an age of 990 +/-\\ 60 RCYBP. The muddy horizon of soil 2 approximately 20-30 cm below the peaty soil yielded an age of 1227 \\pm 30 RCYBP. A Sitka spruce stump in growth position in soil 4 yielded an age of 1698 \\pm$14 RCYBP. These new dates are combined with paleoseismological data from literature in an attempt to find a distribution of recurrence between earthquakes. The accompanying statistical analysis systematically combines the average dates with two comparable sources of standard deviations, arising from (i) radiocarbon dating, and (ii) inter-sample deviations as reported by different authors. The resulting statistical distribution of recurrence intervals in the Cascadia margin allows us to reject both the hypothesis of single normally distributed periodic rate, and Poissonian random recurrence model. The minimal distribution fitting the data is the superposition of two normals, a "short" one with average period of 310 years/standard deviation of 120 years, and a "long" one with average of 820 years and standard deviation of 140 years. This fit leads to

  16. Cause-effect relationships concerning period-doubling bifurcations: step-by-step analysis of a complex system

    NASA Astrophysics Data System (ADS)

    Dejak, Camillo

    In this paper, the cause-effect relationships concerning the occurrence of the period-doubling bifurcation are analysed. Such analysis is carried out by investigating the dynamic of the simplest ODE systems. The governing equations of the system, in fact, contain only one non-linear term. Furthermore, the three state equations can be interpreted in ecological terms. The state equations were integrated using a purposely developed algorithm, based on a fourth order Taylor series expansion. This method allows one to follow the trajectories in a step-by-step detail and to compare the pre- and post-bifurcation ones. The results showed that the bifurcation is due to a very small change in the logarithmic derivative of the state variable which is directly affected by the non-linear term. This change cumulates over time and, in turn, affects the first two main variables, which can be taken as representative of the prey and predator density. The mechanism causes both, the detachment of the two limit cycles and their re-conjunction, after the next period. This finding is also interpreted in thermodynamic terms, by analysing the evolution of an entropy-like function. The above analysis showed that it is possible to detect early signs of bifurcation also for more complex systems and, in these cases, to identify the sub-set of state variables which is more affected by structural changes of the bifurcation dynamic of such systems.

  17. Electronic Circuit Experiments and SPICE Simulation of Double Covering Bifurcation of 2-Torus Quasi-Periodic Flow in Phase-Locked Loop Circuit

    NASA Astrophysics Data System (ADS)

    Kamiyama, Kyohei; Endo, Tetsuro; Imai, Isao; Komuro, Motomasa

    2016-06-01

    Double covering (DC) bifurcation of a 2-torus quasi-periodic flow in a phase-locked loop circuit was experimentally investigated using an electronic circuit and via SPICE simulation; in the circuit, the input radio-frequency signal was frequency modulated by the sum of two asynchronous sinusoidal baseband signals. We observed both DC and period-doubling bifurcations of a discrete map on two Poincaré sections, which were realized by changing the sample timing from one baseband sinusoidal signal to the other. The results confirm the DC bifurcation of the original flow.

  18. Prospective double-blind clinical trial evaluating the effectiveness of Bromelain in the third molar extraction postoperative period

    PubMed Central

    de la Barrera-Núñez, María C.; Yáñez-Vico, Rosa M.; Batista-Cruzado, Antonio; Heurtebise-Saavedra, Jean M.; Castillo-de Oyagüe, Raquel

    2014-01-01

    Objectives: To evaluate the anti-inflammatory and analgesic effect of Bromelain (pineapple extract) administered orally in the postoperative after extraction of impacted lower molars. Study Design: This is a prospective, placebo-controlled, unicentric, double-blind study; the sample size was 34 patients. The pre and postoperative outcomes, evaluated on the third (D3) and eighth day (D8), included inflamtion, pain and oral aperture, as well as the need for analgesics. One group received bromelain 150mg per day for three days and 100mg on days 4 to 7. The other group received placebo in the same dosage. All outcomes werrecorded quantitatively and analyzed with the Mann-Whitney U test for independent samples. Results: Although there were no statistically significant differences between the treatment groups, a trend towards less inflammation and improved oral aperture was observed in the group that received bromelain, compared to the group that received placebo. This trend can be attributed completely to random reasons, since there is no statistical difference in the results. Conclusions: Further studies are necessary to analyze different administration patterns and doses of bromelain for the use in the postoperative of impacted third molars. Key words:Tooth extraction, third molar, postoperative period, bromeline, clinical study. PMID:24316697

  19. Bandgap properties in locally resonant phononic crystal double panel structures with periodically attached spring-mass resonators

    NASA Astrophysics Data System (ADS)

    Qian, Denghui; Shi, Zhiyu

    2016-10-01

    Bandgap properties of the locally resonant phononic crystal double panel structure made of a two-dimensional periodic array of a spring-mass resonator surrounded by n springs (n equals to zero at the beginning of the study) connected between the upper and lower plates are investigated in this paper. The finite element method is applied to calculate the band structure, of which the accuracy is confirmed in comparison with the one calculated by the extended plane wave expansion (PWE) method and the transmission spectrum. Numerical results and further analysis demonstrate that two bands corresponding to the antisymmetric vibration mode open a wide band gap but is cut narrower by a band corresponding to the symmetric mode. One of the regulation rules shows that the lowest frequency on the symmetric mode band is proportional to the spring stiffness. Then, a new design idea of adding springs around the resonator in a unit cell (n is not equal to zero now) is proposed in the need of widening the bandwidth and lowering the starting frequency. Results show that the bandwidth of the band gap increases from 50 Hz to nearly 200 Hz. By introducing the quality factor, the regulation rules with the comprehensive consideration of the whole structure quality limitation, the wide band gap and the low starting frequency are also discussed.

  20. Granular gas in weightlessness: The limit case of very low densities of non interacting spheres

    NASA Astrophysics Data System (ADS)

    Evesque, P.; Palencia, F.; Lecoutre-Chabot, C.; Beysens, D.; Garrabos, Y.

    2005-03-01

    Experiments on non interacting balls in a vibrated box are reported. In a first experiment with an electromagnetic vibrator on earth or in board of Airbus A300 of CNES, the 1-ball dynamics exhibit little transverse motion and an intermittent quasi periodic motion along the direction parallel to the vibration. This behaviour proves a significant reduction of the phase space dimension of this billiard-like system from 11- d to 3- d or 1- d. It is caused by dissipation, which generates non ergodic dynamics. This experiment exemplifies the coupling between translation and rotation degrees of freedom during the collisions with the walls, due to solid friction at contacts. This eliminates ball rotation and freezes transverse velocity fluctuations. This trend is confirmed by 3d simulations with JJ Moreau discrete element code. A two-ball experiment performed under zero-g conditions in the Maxus 5 flight confirms the trend; the quasi-periodicity is found much greater, which is probably due to an improvement of experimental conditions. The two balls are not in perfect synchronisation showing the effect of small random noise; but the particles has never collided. This is then the normal dynamics of a gas of non-interacting dilute spherical grains in a vibrated container.

  1. Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates

    USGS Publications Warehouse

    Mahowald, N.M.; Muhs, D.R.; Levis, S.; Rasch, P.J.; Yoshioka, M.; Zender, C.S.; Luo, C.

    2006-01-01

    Desert dust simulations generated by the National Center for Atmospheric Research's Community Climate System Model for the current climate are shown to be consistent with present day satellite and deposition data. The response of the dust cycle to last glacial maximum, preindustrial, modern, and doubled-carbon dioxide climates is analyzed. Only natural (non-land use related) dust sources are included in this simulation. Similar to some previous studies, dust production mainly responds to changes in the source areas from vegetation changes, not from winds or soil moisture changes alone. This model simulates a +92%, +33%, and -60% change in dust loading for the last glacial maximum, preindustrial, and doubled-carbon dioxide climate, respectively, when impacts of carbon dioxide fertilization on vegetation are included in the model. Terrestrial sediment records from the last glacial maximum compiled here indicate a large underestimate of deposition in continental regions, probably due to the lack of simulation of glaciogenic dust sources. In order to include the glaciogenic dust sources as a first approximation, we designate the location of these sources, and infer the size of the sources using an inversion method that best matches the available data. The inclusion of these inferred glaciogenic dust sources increases our dust flux in the last glacial maximum from 2.1 to 3.3 times current deposition. Copyright 2006 by the American Geophysical Union.

  2. Blue light generated by intra-cavity frequency doubling of an edge-emitting diode laser with a periodically poled LiNbO3 crystal.

    PubMed

    Li, Kang; Yao, Aiyun; Copner, N J; Gawith, C B E; Knight, Ian G; Pfeiffer, Hans-Ulrich; Musk, Bob

    2009-11-23

    We demonstrate for the first time to our knowledge intra-cavity frequency doubling (ICFD) of an edge-emitter diode laser using a 10 mm-long 5.0 microm periodically poled LiNbO(3) (PPLN) crystal. An optical output power of 33 mW second harmonic blue light at 490.5 nm is generated at 1.0 A injection current, equivalent to an overall wall-plug efficiency of 1.8%. The measured M(2) values of blue beam are 1.7 and 2.4 along the fast and slow axis.

  3. Efficient Non-interactive Universally Composable String-Commitment Schemes

    NASA Astrophysics Data System (ADS)

    Nishimaki, Ryo; Fujisaki, Eiichiro; Tanaka, Keisuke

    The universal composability (UC) for commitment is a very strong security notion. It guarantees that commitment schemes remain secure even if they are composed with arbitrary protocols and polynomially many copies of the schemes are run concurrently. Several UC commitment schemes in the common reference string (CRS) model have been proposed, but, they are either interactive commitment or bit-commitment (not string-commitment) schemes. We propose new non-interactive string-commitment schemes that achieve UC security in the CRS model assuming the difficulty of the decisional Diffie-Hellman problem or the decisional composite residuosity problem, but our schemes are not reusable. The main building blocks of our constructions are all-but-one trapdoor functions (ABO-TDFs) introduced by Peikert and Waters in STOC 2008 to construct secure public-key encryption schemes. Our main idea is to use the homomorphic properties of the function indices of the all-but-one trapdoor functions and to extend the functions to probabilistic ones by using re-randomization of ciphertexts. This is a new application of ABO-TDFs.

  4. Ultra-short-period Planets in K2 with Companions: A Double Transiting System for EPIC 220674823

    NASA Astrophysics Data System (ADS)

    Adams, Elisabeth R.; Jackson, Brian; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Duev, Dmitry A.; Jensen-Clem, Rebecca; Salama, Maïssa; Ziegler, Carl; Baranec, Christoph; Kulkarni, Shrinivas; Law, Nicholas M.; Riddle, Reed

    2017-02-01

    Two transiting planets have been identified orbiting K2 target EPIC 220674823. One object is an ultra-short-period planet (USP) with a period of just 0.57 days (13.7 hr), while the other has a period of 13.3 days. Both planets are small, with the former having a radius of {R}{{p}1}=1.5 {R}\\oplus and the latter {R}{{p}2}=2.5 {R}\\oplus . Follow-up observations, including radial velocity (with uncertainties of 110 m s‑1) and high-resolution adaptive optics imagery, show no signs of stellar companions. EPIC 220674823 is the 12th confirmed or validated planetary system in which a USP (i.e., having an orbital period less than 1 day) is accompanied by at least one additional planet, suggesting that such systems may be common and must be accounted for in models for the formation and evolution of such extreme systems.

  5. Influence of graded index materials on the photonic localization in one-dimensional quasiperiodic (Thue-Mosre and Double-Periodic) photonic crystals

    NASA Astrophysics Data System (ADS)

    Singh, Bipin K.; Pandey, Praveen C.

    2014-12-01

    In this paper, we present the investigation on the photonic localization and band gaps in quasi-periodic photonic crystals containing graded index materials using a transfer matrix method in region 150-750 THz of the electromagnetic spectrum. The graded layers have a space dispersive refractive index, which vary in a linear and exponential fashion as a function of the depth of layer. The considered quasiperiodic structures are taken in the form of Thue-Morse and Double-Periodic sequences. The grading profile in the layers affects the position of reflection dips and forbidden bands, and frequency region of the bands. We observed that vast number of forbidden band gaps and dips are developed in its reflection spectra by increasing the number of quasi-periodic generation. Moreover, we compare the total forbidden bandwidths with increasing the generation of the quasi-periodic sequences for the structures with linear and exponential graded layer. Results show that the different graded profiles with same boundary refractive index can change the position of localization modes, number of photonic bands and change the frequency region of the bands. Therefore, we can achieve suitable photonic band gaps and modes by choosing the different gradation profiles of the refractive index and generation of the quasi-periodic sequences.

  6. Electro-optic spectral tuning in a fan-out double-prism domain periodically poled lithium niobate intracavity optical parametric oscillator.

    PubMed

    Chang, W K; Chung, H P; Lin, Y Y; Chen, Y H

    2016-08-15

    We report on the design and experimental demonstration of an electro-optically tunable, pulsed intracavity optical parametric oscillator (IOPO) based on a unique fan-out double-prism domain periodically poled lithium niobate (DPD PPLN) in a diode-pumped Nd:YVO4 laser. The PPLN device combines the functionalities of fan-out and ramped duty-cycle domain structured nonlinear crystals, working simultaneously as a continuous grating-period quasi-phase-matched optical parametric downconverter and an electro-optic beam deflector/Q switch in the laser system. When driving the fan-out DPD PPLN with a voltage pulse train and varying the DC offset of the pulse train, a pulsed IOPO was realized with its signal and idler being electro-optically tunable over the 1880 and 2453 nm bands at spectral tuning rates of 13.5 (measured) and 25.8 (calculated) nm/(kV/mm), respectively.

  7. Kinematic classification of non-interacting spiral galaxies

    NASA Astrophysics Data System (ADS)

    Wiegert, Theresa; English, Jayanne

    2014-01-01

    Using neutral hydrogen (HI) rotation curves of 79 galaxies, culled from the literature, as well as measured from HI data, we present a method for classifying disk galaxies by their kinematics. In order to investigate fundamental kinematic properties we concentrate on non-interacting spiral galaxies. We employ a simple parameterized form for the rotation curve in order to derive the three parameters: the maximum rotational velocity, the turnover radius and a measure of the slope of the rotation curve beyond the turnover radius. Our approach uses the statistical Hierarchical Clustering method to guide our division of the resultant 3D distribution of galaxies into five classes. Comparing the kinematic classes in this preliminary classification scheme to a number of galaxy properties, we find that our class containing galaxies with the largest rotational velocities has a mean morphological type of Sb/Sbc while the other classes tend to later types. Other trends also generally agree with those described by previous researchers. In particular we confirm correlations between increasing maximum rotational velocity and the following observed properties: increasing brightness in B-band, increasing size of the optical disk (D25) and increasing star formation rate (as derived using radio continuum data). Our analysis also suggests that lower velocities are associated with a higher ratio of the HI mass over the dynamical mass. Additionally, three galaxies exhibit a drop in rotational velocity amplitude of ≳20% after the turnover radius. However recent investigations suggest that they have interacted with minor companions which is a common cause for declining rotation curves.

  8. Effect of red chili consumption on postoperative symptoms during the post-hemorrhoidectomy period: randomized, double-blind, controlled study.

    PubMed

    Gupta, Pravin J

    2007-09-01

    The aim of this study was to determine whether there was any relation between consumption of chilies and postoperative symptoms after hemorrhoidectomy in patients with grade III or IV hemorrhoidal disease. A total of 60 patients were randomly assigned to receive antibiotics and analgesics alone (control patients) or daily consumption of 3 g of chili powder along with identical antibiotics and analgesics (chili group). The evaluation of symptoms-pain, anal burning, pruritus, bleeding-during the postoperative period was assessed by means of patients' self-questionnaires. A global score for evaluating each postoperative symptom was compared between the two groups at the 1-week follow-up. No significant difference in age, sex distribution, or grade of disease was noted between the two groups at baseline. The incidence of post-hemorrhoidectomy symptoms was higher in the group consuming chilies during the first postoperative week. The global score for postoperative pain (14.60 for the chili group vs. 7.97 for the control group, p < 0.001) and for anal burning (12.90 for the chili group vs. 7.82 for the control group, p < 0.0001) were significant. Although bleeding (6.95 in the control group and 7.57 in the chili group, p < 0.81) and pruritus (8.06 in the control group and 8.75 in the chili group, p < 0.69) were more common in the chili group, the difference did not achieve statistical significance. This study shows that consumption of 3 g of red chilies per day during the postoperative period after hemorrhoidectomy increases the intensity of typical postoperative symptoms, stool frequency, and the consumption of analgesics.

  9. Analysis of photonic spectra in Thue-Morse, double-period and Rudin-Shapiro quasiregular structures made of high temperature superconductors in visible range

    NASA Astrophysics Data System (ADS)

    Rahimi, H.

    2016-07-01

    The present paper attempts to determine the properties of photonic spectra of Thue-Morse, double-period and Rudin-Shapiro one-dimensional quasiperiodic multilayers. The supposed structures are constituted by high temperature HgBa2Ca2Cu3O10 and YBa2Cu3O7 superconductors. Our investigation is restricted to the visible wavelength domain. The results are demonstrated by the calculation of transmittance using transfer matrix method together with Gorter-Casimir two-fluid model. It is found that by manipulating the parameters such as incident angle, polarization, the thickness of each layer and operation temperature of superconductors the transmission spectra exhibit some interesting features. This paper, provides us a pathway to design tunable total reflector, optical filters and optical switching based on superconductor quasiregular photonic crystals.

  10. Period-doubling bifurcation in two-stage power factor correction converters using the method of incremental harmonic balance and Floquet theory

    NASA Astrophysics Data System (ADS)

    Wang, Fa-Qiang; Zhang, Hao; Ma, Xi-Kui

    2012-02-01

    In this paper, period-doubling bifurcation in a two-stage power factor correction converter is analyzed by using the method of incremental harmonic balance (IHB) and Floquet theory. A two-stage power factor correction converter typically employs a cascade configuration of a pre-regulator boost power factor correction converter with average current mode control to achieve a near unity power factor and a tightly regulated post-regulator DC—DC Buck converter with voltage feedback control to regulate the output voltage. Based on the assumption that the tightly regulated post-regulator DC—DC Buck converter is represented as a constant power sink and some other assumptions, the simplified model of the two-stage power factor correction converter is derived and its approximate periodic solution is calculated by the method of IHB. And then, the stability of the system is investigated by using Floquet theory and the stable boundaries are presented on the selected parameter spaces. Finally, some experimental results are given to confirm the effectiveness of the theoretical analysis.

  11. The Growth Periods Responses of Double-season Paddy Rice to Climate Change in Hunan Province, China over the Past Two Decades

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Li, Y.; Yi, M.; Ye, T.

    2015-12-01

    The shifts of timing and length of the growing season (TLGS) are important indicators of crop response to climate change. With the help of satellite image data, it becomes feasible to retrieve the TLGS in a spatially continuous manner, which also accommodates local variation of TGSs. In this article, the TGSs of paddy rice in Hunan Province, China since 1995 was retrieved using times-series curves of MODIS Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI). The change in TLGS and its connection to regional climate change was discussed. The results showed the advance of TGSs of double-season paddy rice and the reduction of GSL in the past 20 years, which is believed to be linked to the rise in the temperature and precipitation in the growth periods. Understanding the local variation and trend of TLGS influenced by climate change is essential for making agricultural adaptive policies to reduce the risk of crop damaged, also can provide key information for studying how multi-hazards affect crop exposure.

  12. Optimal Vaccination in a Stochastic Epidemic Model of Two Non-Interacting Populations

    DTIC Science & Technology

    2015-02-17

    RESEARCH ARTICLE Optimal Vaccination in a Stochastic Epidemic Model of Two Non-Interacting Populations Edwin C. Yuan1,3, David L. Alderson2, Sean...Infected-Recovered (SIR) model. Based on these results, we determine the optimal alloca- tions of a limited quantity of vaccine between two non-interacting... vaccine , the deterministic model is a poor estimate of the optimal strategy for the more realistic, stochastic case. Introduction As rapid, long-range

  13. On the v-representabilty problem in density functional theory: Application to non-interacting systems

    DOE PAGES

    Dane, Markus; Gonis, Antonios

    2016-07-05

    Based on a computational procedure for determining the functional derivative with respect to the density of any antisymmetric N-particle wave function for a non-interacting system that leads to the density, we devise a test as to whether or not a wave function known to lead to a given density corresponds to a solution of a Schrödinger equation for some potential. We examine explicitly the case of non-interacting systems described by Slater determinants. Here, numerical examples for the cases of a one-dimensional square-well potential with infinite walls and the harmonic oscillator potential illustrate the formalism.

  14. Reliability of cortical lesion detection on double inversion recovery MRI applying the MAGNIMS-Criteria in multiple sclerosis patients within a 16-months period

    PubMed Central

    Thaler, Christian; Ceyrowski, Tim; Broocks, Gabriel; Treffler, Natascha; Sedlacik, Jan; Stürner, Klarissa; Stellmann, Jan-Patrick; Heesen, Christoph; Fiehler, Jens; Siemonsen, Susanne

    2017-01-01

    Purpose In patients with multiple sclerosis (MS), Double Inversion Recovery (DIR) magnetic resonance imaging (MRI) can be used to identify cortical lesions (CL). We sought to evaluate the reliability of CL detection on DIR longitudinally at multiple subsequent time-points applying the MAGNIMs scoring criteria for CLs. Methods 26 MS patients received a 3T-MRI (Siemens, Skyra) with DIR at 12 time-points (TP) within a 16 months period. Scans were assessed in random order by two different raters. Both raters separately marked all CLs on each scan and total lesion numbers were obtained for each scan-TP and patient. After a retrospective re-evaluation, the number of consensus CLs (conL) was defined as the total number of CLs, which both raters finally agreed on. CLs volumes, relative signal intensities and CLs localizations were determined. Both ratings (conL vs. non-consensus scoring) were compared for further analysis. Results A total number of n = 334 CLs were identified by both raters in 26 MS patients with a first agreement of both raters on 160 out of 334 of the CLs found (κ = 0.48). After the retrospective re-evaluation, consensus agreement increased to 233 out of 334 CL (κ = 0.69). 93.8% of conL were visible in at least 2 consecutive TP. 74.7% of the conL were visible in all 12 consecutive TP. ConL had greater mean lesion volumes and higher mean signal intensities compared to lesions that were only detected by one of the raters (p<0.05). A higher number of CLs in the frontal, parietal, temporal and occipital lobe were identified by both raters than the number of those only identified by one of the raters (p<0.05). Conclusions After a first assessment, slightly less than a half of the CL were considered as reliably detectable on longitudinal DIR images. A retrospective re-evaluation notably increased the consensus agreement. However, this finding is narrowed, considering the fact that retrospective evaluation steps might not be practicable in clinical routine

  15. Can Non-Interactive Language Input Benefit Young Second-Language Learners?

    ERIC Educational Resources Information Center

    Au, Terry Kit-fong; Chan, Winnie Wailan; Cheng, Liao; Siegel, Linda S.; Tso, Ricky Van Yip

    2015-01-01

    To fully acquire a language, especially its phonology, children need linguistic input from native speakers early on. When interaction with native speakers is not always possible--e.g. for children learning a second language that is not the societal language--audios are commonly used as an affordable substitute. But does such non-interactive input…

  16. Non-interacting proteins may resemble interacting proteins: prevalence and implications

    PubMed Central

    Launay, Guillaume; Ceres, Nicoletta; Martin, Juliette

    2017-01-01

    The vast majority of proteins do not form functional interactions in physiological conditions. We have considered several sets of protein pairs from S. cerevisiae with no functional interaction reported, denoted as non-interacting pairs, and compared their 3D structures to available experimental complexes. We identified some non-interacting pairs with significant structural similarity with experimental complexes, indicating that, even though they do not form functional interactions, they have compatible structures. We estimate that up to 8.7% of non-interacting protein pairs could have compatible structures. This number of interactions exceeds the number of functional interactions (around 0.2% of the total interactions) by a factor 40. Network analysis suggests that the interactions formed by non-interacting pairs with compatible structures could be particularly hazardous to the protein-protein interaction network. From a structural point of view, these interactions display no aberrant structural characteristics, and are even predicted as relatively stable and enriched in potential physical interactors, suggesting a major role of regulation to prevent them. PMID:28084410

  17. Q-switched quasi-phase-matched self-frequency doubling and summing in a laser based on a periodically poled Nd : Mg : LiNbO{sub 3} crystal

    SciTech Connect

    Laptev, G D; Novikov, Aleksei A; Firsov, V V

    2004-03-31

    Quasi-phase-matched second harmonic generation at 542 nm by self-frequency doubling laser radiation at 1084 nm and quasi-phase-matched sum-frequency generation at 464 nm by summing frequencies of laser radiation and of nonabsorbed fraction of diode laser pump radiation at 810 nm are experimentally achieved. These processes are realised in a Q-switched laser based on a periodically poled active nonlinear Nd : Mg : LiNbO{sub 3} crystal. (nonlinear optical phenomena)

  18. Can non-interactive language input benefit young second-language learners?

    PubMed

    Au, Terry Kit-Fong; Chan, Winnie Wailan; Cheng, Liao; Siegel, Linda S; Tso, Ricky Van Yip

    2015-03-01

    To fully acquire a language, especially its phonology, children need linguistic input from native speakers early on. When interaction with native speakers is not always possible - e.g. for children learning a second language that is not the societal language - audios are commonly used as an affordable substitute. But does such non-interactive input work? Two experiments evaluated the usefulness of audio storybooks in acquiring a more native-like second-language accent. Young children, first- and second-graders in Hong Kong whose native language was Cantonese Chinese, were given take-home listening assignments in a second language, either English or Putonghua Chinese. Accent ratings of the children's story reading revealed measurable benefits of non-interactive input from native speakers. The benefits were far more robust for Putonghua than English. Implications for second-language accent acquisition are discussed.

  19. Signcryption with Non-interactive Non-repudiation without Random Oracles

    NASA Astrophysics Data System (ADS)

    Fan, Jia; Zheng, Yuliang; Tang, Xiaohu

    Non-repudiation is a very important requirement of signcryption. It ensures that a sender cannot deny the fact that he has signcrypted a message. Non-interactive non-repudiation enables a receiver to settle a repudiation dispute with the help of a judge without the need to engage in costly multi-round interactive communications with the judge. In this paper, we strengthen Malone-Lee's security model for signcryption with non-interactive non-repudiation by introducing two additional, more subtle and useful security requirements, one about the unforgeability and the other about the confidentiality of non-repudiation evidence. A further contribution of this paper is to design a concrete signcryption scheme that admits provable security without random oracles in our strengthened security model for signcryption.

  20. Freshness-preserving non-interactive hierarchical key agreement protocol over WHMS.

    PubMed

    Kim, Hyunsung

    2014-12-10

    The digitization of patient health information (PHI) for wireless health monitoring systems (WHMSs) has brought many benefits and challenges for both patients and physicians. However, security, privacy and robustness have remained important challenges for WHMSs. Since the patient's PHI is sensitive and the communication channel, i.e., the Internet, is insecure, it is important to protect them against unauthorized entities, i.e., attackers. Otherwise, failure to do so will not only lead to the compromise of a patient's privacy, but will also put his/her life at risk. This paper proposes a freshness-preserving non-interactive hierarchical key agreement protocol (FNKAP) for WHMSs. The FNKAP is based on the concept of the non-interactive identity-based key agreement for communication efficiency. It achieves patient anonymity between a patient and physician, session key secrecy and resistance against various security attacks, especially including replay attacks.

  1. Freshness-Preserving Non-Interactive Hierarchical Key Agreement Protocol over WHMS

    PubMed Central

    Kim, Hyunsung

    2014-01-01

    The digitization of patient health information (PHI) for wireless health monitoring systems (WHMSs) has brought many benefits and challenges for both patients and physicians. However, security, privacy and robustness have remained important challenges for WHMSs. Since the patient's PHI is sensitive and the communication channel, i.e., the Internet, is insecure, it is important to protect them against unauthorized entities, i.e., attackers. Otherwise, failure to do so will not only lead to the compromise of a patient's privacy, but will also put his/her life at risk. This paper proposes a freshness-preserving non-interactive hierarchical key agreement protocol (FNKAP) for WHMSs. The FNKAP is based on the concept of the non-interactive identity-based key agreement for communication efficiency. It achieves patient anonymity between a patient and physician, session key secrecy and resistance against various security attacks, especially including replay attacks. PMID:25513824

  2. Specific heat spectra of non-interacting fermions in a quasiperiodic ladder sequence

    NASA Astrophysics Data System (ADS)

    Moreira, D. A.; Albuquerque, E. L.; Anselmo, D. H. A. L.

    2008-07-01

    We compute the specific heat spectra of non-interacting fermions whose energy spectrum was obtained from a quasiperiodic ladder sequence (Fibonacci and Rudin-Shapiro type), mimicking a DNA molecule model. The specific heat is calculated from their underlying multi-fractal energy spectrum, considering several values of energy densities. Comparisons are made with a real DNA sequence, namely the human chromosome 22 (Ch22).

  3. An Interferometric Harvest of Double Degenerates

    NASA Astrophysics Data System (ADS)

    Nelan, Edmund

    2001-07-01

    The white dwarf {WD} mass and age distributions hold clues to the star formation history of our Galaxy and the age of the disk. To extract this information we need to carefully calibrate the WD mass-radius relation and the WD cooling curve. But to do so, we must directly determine the masses for a variety of WDs of different sub-types. The only direct method is through the orbital analysis of resolved WDs in non- interacting binary systems. Sadly, this has been done, with varying quality, for only 4 WDs {40 Eri B, Sirius B, Procyon B, and Stien 2051B}, mainly because it is extremely difficult to resolve WDs in binary systems with periods less than 50 years. We propose a high angular resolution Snapshot survey with FGS1r to observe cool WDs with the objective of discovering {resolving} double degenerate systems with modest separations and periods as short as 25 years, ideal binaries for follow up mass determinations. By carefully selecting our targets, about 10 such systems should be revealed. This will dramatically increase the number of WDs available for dynamical mass measurements {its 2 for 1.}, enabling a better calibration the WD mass-radius relation.

  4. Search for primarily non-interacting decay modes of the upsilon

    SciTech Connect

    Leffler, J.S.

    1986-03-01

    The hadronic transition UPSILON(2S) ..-->.. ..pi../sup 0/..pi../sup 0/UPSILON(1S) is utilized to search for the reactions: UPSILON(1S) ..-->.. non-interacting particles and UPSILON(1S) ..-->.. ..gamma.. + non-interacting particles. 44 pb/sup -1/ of UPSILON(2S) data were taken by the Crystal Ball detector at the DORIS II storage ring in order to perform this study. An upper limit of BR(UPSILON ..-->.. Unseen) < 12% (90% C.L.), is obtained via this approach. The second process investigated involved the radiative decay of the Upsilon into non-interacting particles. 57 pb/sup -1/ of UPSILON(2S) data was available for this study. An upper limit on the branching ratio BR(UPSILON ..-->.. ..gamma.. + Unseen) is measured for photon energies in the range 500 MeV < E..gamma.. < M/sub ..gamma..//2. This is the first reported measurement of this type. For the highest energy photons, an upper limit of BR(UPSILON ..-->.. ..gamma.. + Unseen) < 2.3 x 10/sup -3/ (90% C.L.), is obtained. The compact size of the Crystal Ball detector enhances the observable branching ratio for noninteracting particles with short lifetimes such as massive axions. The identification of the recent Darmstadt events with a 1.6 MeV axion is excluded by the present result assuming the minimal Peccei-Quinn model. Limits on the spontaneous supersymmetry breaking mass scale are also derived as a function of gravitino mass.

  5. Revisiting the density scaling of the non-interacting kinetic energy.

    PubMed

    Borgoo, Alex; Teale, Andrew M; Tozer, David J

    2014-07-28

    Scaling relations play an important role in the understanding and development of approximate functionals in density functional theory. Recently, a number of these relationships have been redefined in terms of the Kohn-Sham orbitals [Calderín, Phys. Rev. A: At., Mol., Opt. Phys., 2013, 86, 032510]. For density scaling the author proposed a procedure involving a multiplicative scaling of the Kohn-Sham orbitals whilst keeping their occupation numbers fixed. In the present work, the differences between this scaling with fixed occupation numbers and that of previous studies, where the particle number change implied by the scaling was accommodated through the use of the grand canonical ensemble, are examined. We introduce the terms orbital and ensemble density scaling for these approaches, respectively. The natural ambiguity of the density scaling of the non-interacting kinetic energy functional is examined and the ancillary definitions implicit in each approach are highlighted and compared. As a consequence of these differences, Calderín recovered a homogeneity of degree 1 for the non-interacting kinetic energy functional under orbital scaling, contrasting recent work by the present authors [J. Chem. Phys., 2012, 136, 034101] where the functional was found to be inhomogeneous under ensemble density scaling. Furthermore, we show that the orbital scaling result follows directly from the linearity and the single-particle nature of the kinetic energy operator. The inhomogeneity of the non-interacting kinetic energy functional under ensemble density scaling can be quantified by defining an effective homogeneity. This quantity is shown to recover the homogeneity values for important approximate forms that are exact for limiting cases such as the uniform electron gas and one-electron systems. We argue that the ensemble density scaling provides more insight into the development of new functional forms.

  6. Anonymous One-Time Broadcast Using Non-interactive Dining Cryptographer Nets with Applications to Voting

    NASA Astrophysics Data System (ADS)

    van de Graaf, Jeroen

    All voting protocols proposed so far, with the exception of a few, have the property that the privacy of the ballot is only computational. In this paper we outline a new and conceptually simple approach allowing us to construct a protocol in which the privacy of the ballot is unconditional. Our basic idea is to modify the protocol of Fujioka, Okamoto and Ohta[1], which uses blind signatures so that the voter can obtain a valid ballot. However, instead of using a MIX net, we use a new broadcast protocol for anonymously publishing the vote, a Non-Interactive variation of the Dining Cryptographer Net.

  7. Topological phases: classification of topological insulators and superconductors of non-interacting fermions, and beyond

    NASA Astrophysics Data System (ADS)

    Ludwig, Andreas W. W.

    2016-12-01

    After briefly recalling the quantum entanglement-based view of topological phases of matter in order to outline the general context, we give an overview of different approaches to the classification problem of topological insulators and superconductors of non-interacting fermions. In particular, we review in some detail general symmetry aspects of the ‘ten-fold way’ which forms the foundation of the classification, and put different approaches to the classification in relationship with each other. We end by briefly mentioning some of the results obtained on the effect of interactions, mainly in three spatial dimensions.

  8. Convex Decompositions of Thermal Equilibrium for Non-interacting Non-relativistic Particles

    NASA Astrophysics Data System (ADS)

    Chenu, Aurelia; Branczyk, Agata; Sipe, John

    2016-05-01

    We provide convex decompositions of thermal equilibrium for non-interacting non-relativistic particles in terms of localized wave packets. These quantum representations offer a new tool and provide insights that can help relate to the classical picture. Considering that thermal states are ubiquitous in a wide diversity of fields, studying different convex decompositions of the canonical ensemble is an interesting problem by itself. The usual classical and quantum pictures of thermal equilibrium of N non-interacting, non-relativistic particles in a box of volume V are quite different. The picture in classical statistical mechanics is about (localized) particles with a range of positions and velocities; in quantum statistical mechanics, one considers the particles (bosons or fermions) associated with energy eigenstates that are delocalized through the whole box. Here we provide a representation of thermal equilibrium in quantum statistical mechanics involving wave packets with a localized coordinate representation and an expectation value of velocity. In addition to derive a formalism that may help simplify particular calculations, our results can be expected to provide insights into the transition from quantum to classical features of the fully quantum thermal state.

  9. Maternal Deworming Research Study (MADRES) protocol: a double-blind, placebo-controlled randomised trial to determine the effectiveness of deworming in the immediate postpartum period

    PubMed Central

    Mofid, Layla S; Casapía, Martín; Montresor, Antonio; Rahme, Elham; Fraser, William D; Marquis, Grace S; Vercruysse, Jozef; Allen, Lindsay H; Gyorkos, Theresa W

    2015-01-01

    Introduction Soil-transmitted helminth infections are endemic in 114 countries worldwide, and cause the highest burden of disease among all neglected tropical diseases. The WHO includes women of reproductive age as a high-risk group for infection. The primary consequence of infection in this population is anaemia. During lactation, anaemia may contribute to reduced quality and quantity of milk, decreasing the duration of exclusive breastfeeding and lowering the age at weaning. To date, no study has investigated the effects of maternal postpartum deworming on infant or maternal health outcomes. Methods and analysis A single-centre, parallel, double-blind, randomised, placebo-controlled trial will be carried out in Iquitos, Peru, to assess the effectiveness of integrating single-dose 400 mg albendazole into routine maternal postpartum care. A total of 1010 mother-infant pairs will be randomised to either the intervention or control arm, following inhospital delivery and prior to discharge. Participants will be visited in their homes at 1, 6, 12 and 24 months following delivery for outcome ascertainment. The primary outcome is infant mean weight gain between birth and 6 months of age. Secondary outcomes include other infant growth indicators and morbidity, maternal soil-transmitted helminth infection and intensity, anaemia, fatigue, and breastfeeding practices. All statistical analyses will be performed on an intention-to-treat basis. Ethics and dissemination Research ethics board approval has been obtained from the McGill University Health Centre (Canada), the Asociación Civil Impacta Salud y Educación (Peru) and the Instituto Nacional de Salud (Peru). A data safety and monitoring committee is in place to oversee study progression and evaluate adverse events. The results of the analyses will be published in peer-reviewed journals, and presented at national and international conferences. Trial registration number Clinicaltrials.gov: NCT01748929. PMID:26084556

  10. Can a brief period of double J stenting improve the outcome of extracorporeal shock wave lithotripsy for renal calculi sized 1 to 2 cm?

    PubMed Central

    Sharma, Rakesh; Das, Ranjit Kumar; Basu, Supriya; Dey, Ranjan Kumar; Gupta, Rupesh; Deb, Partha Pratim

    2017-01-01

    Purpose Extracorporeal shock wave lithotripsy (ESWL) is an established modality for renal calculi. Its role for large stones is being questioned. A novel model of temporary double J (DJ) stenting followed by ESWL was devised and outcomes were assessed. Materials and Methods The study included 95 patients with renal calculi sized 1 to 2 cm. Patients were randomized into 3 groups. Group 1 received ESWL only, whereas group 2 underwent stenting followed by ESWL. In group 3, a distinct model was applied in which the stent was kept for 1 week and then removed, followed by ESWL. Procedural details, analgesic requirements, and outcome were analyzed. Results Eighty-eight patients (male, 47; female, 41) were available for analysis. The patients' mean age was 37.9±10.9 years. Stone profile was similar among groups. Group 3 received fewer shocks (mean, 3,155) than did group 1 (mean, 3,859; p=0.05) or group 2 (mean, 3,872; p=0.04). The fragmentation rate was similar in group 3 (96.7%) and groups 1 (81.5%, p=0.12) and 2 (87.1%, p=0.16). Overall clearance in group 3 was significantly improved (83.3%) compared with that in groups 1 (63.0%, p=0.02) and 2 (64.5%, p=0.02) and was maintained even in lower pole stones. The percentage successful outcome in groups 1, 2, and 3 was 66.7%, 64.5%, and 83.3%, respectively (p=0.21). The analgesic requirement in group 2 was higher than in the other groups (p=0.00). Group 2 patients also had more grade IIIa (2/3) and IIIB (1/2) complications. Conclusions Stenting adversely affects stone clearance and also makes the later course uncomfortable. Our model of brief stenting followed by ESWL provided better clearance, comfort, and a modest improvement in outcome with fewer sittings and steinstrasse in selected patients with large renal calculi. PMID:28261679

  11. Does the Coherent Lidar System Corroborate Non-Interaction of Waves (NIW)?

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S.; Roychoudhari, Chandrasekhar

    2013-01-01

    The NIW (non-interaction of waves) property has been proposed by one of the coauthors. The NIW property states that in the absence of any "obstructing" detectors, all the Huygens-Fresnel secondary wavelets will continue to propagate unhindered and without interacting (interfering) with each other. Since a coherent lidar system incorporates complex behaviors of optical components with different polarizations including circular polarization for the transmitted radiation, then the question arises whether the NIW principle accommodate elliptical polarization of light. Elliptical polarization presumes the summation of orthogonally polarized electric field vectors which contradicts the NIW principle. In this paper, we present working of a coherent lidar system using Jones matrix formulation. The Jones matrix elements represent the anisotropic dipolar properties of molecules of optical components. Accordingly, when we use the Jones matrix methodology to analyze the coherent lidar system, we find that the system behavior is congruent with the NIW property.

  12. Authentication Based on Non-Interactive Zero-Knowledge Proofs for the Internet of Things

    PubMed Central

    Martín-Fernández, Francisco; Caballero-Gil, Pino; Caballero-Gil, Cándido

    2016-01-01

    This paper describes the design and analysis of a new scheme for the authenticated exchange of confidential information in insecure environments within the Internet of Things, which allows a receiver of a message to authenticate the sender and compute a secret key shared with it. The proposal is based on the concept of a non-interactive zero-knowledge proof, so that in a single communication, relevant data may be inferred to verify the legitimacy of the sender. Besides, the new scheme uses the idea under the Diffie–Hellman protocol for the establishment of a shared secret key. The proposal has been fully developed for platforms built on the Android Open Source Project, so it can be used in any device or sensor with this operating system. This work provides a performance study of the implementation and a comparison between its promising results and others obtained with similar schemes. PMID:26751454

  13. Authentication Based on Non-Interactive Zero-Knowledge Proofs for the Internet of Things.

    PubMed

    Martín-Fernández, Francisco; Caballero-Gil, Pino; Caballero-Gil, Cándido

    2016-01-07

    This paper describes the design and analysis of a new scheme for the authenticated exchange of confidential information in insecure environments within the Internet of Things, which allows a receiver of a message to authenticate the sender and compute a secret key shared with it. The proposal is based on the concept of a non-interactive zero-knowledge proof, so that in a single communication, relevant data may be inferred to verify the legitimacy of the sender. Besides, the new scheme uses the idea under the Diffie-Hellman protocol for the establishment of a shared secret key. The proposal has been fully developed for platforms built on the Android Open Source Project, so it can be used in any device or sensor with this operating system. This work provides a performance study of the implementation and a comparison between its promising results and others obtained with similar schemes.

  14. Evolution of non-interacting entropic dark energy and its phantom nature

    NASA Astrophysics Data System (ADS)

    Mathew, Titus K.; Murali, Chinthak; Shejeelammal, J.

    2016-04-01

    Assuming the form of the entropic dark energy (EDE) as it arises from the surface term in the Einstein-Hilbert’s action, its evolution was analyzed in an expanding flat universe. The model parameters were evaluated by constraining the model using the Union data on Type Ia supernovae. We found that in the non-interacting case, the model predicts an early decelerated phase and a later accelerated phase at the background level. The evolutions of the Hubble parameter, dark energy (DE) density, equation of state parameter and deceleration parameter were obtained. The model hardly seems to be supporting the linear perturbation growth for the structure formation. We also found that the EDE shows phantom nature for redshifts z < 0.257. During the phantom epoch, the model predicts big rip effect at which both the scale factor of expansion and the DE density become infinitely large and the big rip time is found to be around 36 Giga years from now.

  15. Interactive and Non-Interactive Pictures in Multimedia Learning Environments: Effects on Learning Outcomes and Learning Efficiency

    ERIC Educational Resources Information Center

    Rasch, Thorsten; Schnotz, Wolfgang

    2009-01-01

    New technologies enable flexible combinations of text and interactive or non-interactive pictures. The aim of the present study was to investigate (a) whether adding pictures to texts is generally beneficial for learning or whether it can also have detrimental effects, (b) how interactivity of pictures affects learning, (c) whether the…

  16. An evaluation of the cognitive and mood effects of an energy shot over a 6h period in volunteers: a randomized, double-blind, placebo controlled, cross-over study.

    PubMed

    Wesnes, Keith A; Barrett, Marilyn L; Udani, Jay K

    2013-08-01

    Energy drinks are widely available mostly containing glucose, and several have been demonstrated to improve alertness and cognitive function; these effects generally being identified 30-60min after administration. The present study assessed whether an energy shot without carbohydrates would affect major aspects of cognitive function and also mood in volunteers over a 6h time period. This randomized, double-blind, placebo-controlled,crossover study compared the acute effects of the energy shot with a matching placebo in 94 healthy volunteers. Cognitive function was assessed with a widely used set of automated tests of attention and memory. Mood was assessed with the Bond-Lader, Beck Anxiety Index, Beck Depression Index, Chalder Fatigue Scales (CFS), and the POMS. The volunteers were requested to limit their sleep to between 3 and 6h the night before each testing day. Compared to the placebo, the energy shot significantly improved 6 validated composite cognitive function measures from the CDR System as well as self-rated alertness; the benefits on 4 of the cognitive measures still remaining at 6h. The overall effect sizes of the performance improvements were in the small to medium range and thus notable in this field. In conclusion, an energy shot can significantly improve important aspects of cognitive function for up to 6h compared to placebo in partially sleep-deprived healthy volunteers.

  17. Tabletop demonstration of non-Interaction of photons and non-interference of waves

    NASA Astrophysics Data System (ADS)

    Prasad, Narasimha S.; Roychoudhuri, Chandra

    2015-09-01

    Recently, Non- Interaction of Waves or the NIW property has been proposed as a generic property of all propagating electromagnetic waves by one of the authors (CR). In other words, optical beams do not interact with each other to modify or re-distribute their field energy distribution in the absence of interacting materials. In this paper, path taken to re-create CR's original demonstration of the NIW-property as an on-site tabletop experiment is discussed. Since 1975, when the NIW demonstration was first reported, several advances in lasers and optical component design architecture have occurred. With the goal of using low cost components and having agility in setting up on non-conformable platforms for general viewing, a compact arrangement for demonstrating the NIW property was envisioned. In our experimental arrangement, a beam multiplier element was utilized to generate a set of spatially separate parallel beams out of an incident laser beam. The emerging parallel beams from the beam multiplier element were then focused on a one-sided ground glass, the flat side being towards the beam multiplier. This flat side reflects off all the incident focused beams as fanning out independent laser beams, remaining unperturbed even though they are reflecting out of a common superposed spot. It is clear that there is neither "interference between different photons", nor "a photon interferes with itself", even within a region of superposed beams. In contrast, the ground glass surface (same silica molecules but granular or lumpy) was anticipated to generate a set of crisp spatial fringes on its surface as in the original experiment. The fringes are due to granulated individual silica lumps responding simultaneously to the local resultant E-vectors due to all the superposed beams and are scattering energy proportional to the square modulus of the sum of all the simultaneous dipolar amplitude stimulations. The dark fringe locations imply zero resultant amplitude stimulation

  18. Effective homogeneity of the exchange-correlation and non-interacting kinetic energy functionals under density scaling.

    PubMed

    Borgoo, Alex; Teale, Andrew M; Tozer, David J

    2012-01-21

    Correlated electron densities, experimental ionisation potentials, and experimental electron affinities are used to investigate the homogeneity of the exchange-correlation and non-interacting kinetic energy functionals of Kohn-Sham density functional theory under density scaling. Results are presented for atoms and small molecules, paying attention to the influence of the integer discontinuity and the choice of the electron affinity. For the exchange-correlation functional, effective homogeneities are highly system-dependent on either side of the integer discontinuity. By contrast, the average homogeneity-associated with the potential that averages over the discontinuity-is generally close to 4/3 when the discontinuity is computed using positive affinities for systems that do bind an excess electron and negative affinities for those that do not. The proximity to 4/3 becomes increasingly pronounced with increasing atomic number. Evaluating the discontinuity using a zero affinity in systems that do not bind an excess electron instead leads to effective homogeneities on the electron abundant side that are close to 4/3. For the non-interacting kinetic energy functional, the effective homogeneities are less system-dependent and the effect of the integer discontinuity is less pronounced. Average values are uniformly below 5/3. The study provides information that may aid the development of improved exchange-correlation and non-interacting kinetic energy functionals.

  19. [Double responses].

    PubMed

    Motté, G; Dinanian, S; Sebag, C; Drieu, L; Slama, M

    1995-12-01

    Double response is a rare electrocardiographic phenomenon requiring two atrioventricular conduction pathways with very different electrophysiological properties. Double ventricular responses are the usual manifestation: an atrial depolarisation (spontaneous or provoked, anticipated or not) is followed by a first ventricular response dependent on an accessory pathway or a rapid nodal pathway and then a second response resulting from sufficiently delayed transmission through a nodal pathway for the ventricles to have recovered their excitability when the second wave of activation reaches them. A simple curiosity when isolated and occurring under unusual conditions, particularly during electrophysiological investigation of the Wolff-Parkinson-White syndrome, the double response may initiate symptomatic non-reentrant junctional tachycardia when associated with nodal duality and repeating from atria in sinus rhythm. The functional incapacity and resistance to antiarrhythmic therapy may require referral for ablation of the slow pathway.

  20. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (Editor); Moorehead, Tauna W. (Editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  1. Double screening

    SciTech Connect

    Gratia, Pierre; Hu, Wayne; Joyce, Austin; Ribeiro, Raquel H.

    2016-06-15

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  2. Method for physiologic phenotype characterization at the single-cell level in non-interacting and interacting cells

    NASA Astrophysics Data System (ADS)

    Kelbauskas, Laimonas; Ashili, Shashanka P.; Houkal, Jeff; Smith, Dean; Mohammadreza, Aida; Lee, Kristen B.; Forrester, Jessica; Kumar, Ashok; Anis, Yasser H.; Paulson, Thomas G.; Youngbull, Cody A.; Tian, Yanqing; Holl, Mark R.; Johnson, Roger H.; Meldrum, Deirdre R.

    2012-03-01

    Intercellular heterogeneity is a key factor in a variety of core cellular processes including proliferation, stimulus response, carcinogenesis, and drug resistance. However, cell-to-cell variability studies at the single-cell level have been hampered by the lack of enabling experimental techniques. We present a measurement platform that features the capability to quantify oxygen consumption rates of individual, non-interacting and interacting cells under normoxic and hypoxic conditions. It is based on real-time concentration measurements of metabolites of interest by means of extracellular optical sensors in cell-isolating microwells of subnanoliter volume. We present the results of a series of measurements of oxygen consumption rates (OCRs) of individual non-interacting and interacting human epithelial cells. We measured the effects of cell-to-cell interactions by using the system's capability to isolate two and three cells in a single well. The major advantages of the approach are: 1. ratiometric, intensity-based characterization of the metabolic phenotype at the single-cell level, 2. minimal invasiveness due to the distant positioning of sensors, and 3. ability to study the effects of cell-cell interactions on cellular respiration rates.

  3. Construction of exchange-correlation functionals through interpolation between the non-interacting and the strong-correlation limit

    SciTech Connect

    Zhou, Yongxi; Ernzerhof, Matthias; Bahmann, Hilke

    2015-09-28

    Drawing on the adiabatic connection of density functional theory, exchange-correlation functionals of Kohn-Sham density functional theory are constructed which interpolate between the extreme limits of the electron-electron interaction strength. The first limit is the non-interacting one, where there is only exchange. The second limit is the strong correlated one, characterized as the minimum of the electron-electron repulsion energy. The exchange-correlation energy in the strong-correlation limit is approximated through a model for the exchange-correlation hole that is referred to as nonlocal-radius model [L. O. Wagner and P. Gori-Giorgi, Phys. Rev. A 90, 052512 (2014)]. Using the non-interacting and strong-correlated extremes, various interpolation schemes are presented that yield new approximations to the adiabatic connection and thus to the exchange-correlation energy. Some of them rely on empiricism while others do not. Several of the proposed approximations yield the exact exchange-correlation energy for one-electron systems where local and semi-local approximations often fail badly. Other proposed approximations generalize existing global hybrids by using a fraction of the exchange-correlation energy in the strong-correlation limit to replace an equal fraction of the semi-local approximation to the exchange-correlation energy in the strong-correlation limit. The performance of the proposed approximations is evaluated for molecular atomization energies, total atomic energies, and ionization potentials.

  4. Simulation of plasma double-layer structures

    NASA Technical Reports Server (NTRS)

    Borovsky, J. E.; Joyce, G.

    1982-01-01

    Electrostatic plasma double layers are numerically simulated by means of a magnetized 2 1/2 dimensional particle in cell method. The investigation of planar double layers indicates that these one dimensional potential structures are susceptible to periodic disruption by instabilities in the low potential plasmas. Only a slight increase in the double layer thickness with an increase in its obliqueness to the magnetic field is observed. Weak magnetization results in the double layer electric field alignment of accelerated particles and strong magnetization results in their magnetic field alignment. The numerical simulations of spatially periodic two dimensional double layers also exhibit cyclical instability. A morphological invariance in two dimensional double layers with respect to the degree of magnetization implies that the potential structures scale with Debye lengths rather than with gyroradii. Electron beam excited electrostatic electron cyclotron waves and (ion beam driven) solitary waves are present in the plasmas adjacent to the double layers.

  5. Time domain period determination techniques

    NASA Technical Reports Server (NTRS)

    Stellingwerf, R. F.

    1980-01-01

    Two simple period determination schemes are discussed. They are well suited to problems involving non-sinusoidal periodic phenomena sampled at a few irregularly spaced points. Statistical properties are discussed. The techniques are applied to the double mode Cepheids BK Cen and TU Cas as test cases.

  6. Time domain period determination techniques

    NASA Astrophysics Data System (ADS)

    Stellingwerf, R. F.

    1980-05-01

    Two simple period determination schemes are discussed. They are well suited to problems involving non-sinusoidal periodic phenomena sampled at a few irregularly spaced points. Statistical properties are discussed. The techniques are applied to the double mode Cepheids BK Cen and TU Cas as test cases.

  7. Irregular Periods

    MedlinePlus

    ... number of days after the last one. The Menstrual Cycle Most girls get their first period between the ... to skip periods or to have an irregular menstrual cycle. Illness, rapid weight change, or stress can also ...

  8. Motion in an asymmetric double well

    NASA Astrophysics Data System (ADS)

    Brizard, Alain J.; Westland, Melissa C.

    2017-02-01

    The problem of the periodic motion of a particle in an asymmetric double-well (quartic) potential is solved explicitly in terms of the Weierstrass and Jacobi elliptic functions. While the solution of the orbital motion is expressed simply in terms of the Weierstrass elliptic function, the period of oscillation is more directly expressed in terms of periods of the Jacobi elliptic functions.

  9. Period Pain

    MedlinePlus

    ... You may also have other symptoms, such as lower back pain, nausea, diarrhea, and headaches. Period pain is not ... Taking a hot bath Doing relaxation techniques, including yoga and meditation You might also try taking over- ...

  10. Periodized wavelets

    SciTech Connect

    Schlossnagle, G.; Restrepo, J.M.; Leaf, G.K.

    1993-12-01

    The properties of periodized Daubechies wavelets on [0,1] are detailed and contrasted against their counterparts which form a basis for L{sup 2}(R). Numerical examples illustrate the analytical estimates for convergence and demonstrate by comparison with Fourier spectral methods the superiority of wavelet projection methods for approximations. The analytical solution to inner products of periodized wavelets and their derivatives, which are known as connection coefficients, is presented, and several tabulated values are included.

  11. Seeing Double

    NASA Astrophysics Data System (ADS)

    Pesic, Peter

    2003-10-01

    The separateness and connection of individuals is perhaps the central question of human life: What, exactly, is my individuality? To what degree is it unique? To what degree can it be shared, and how? To the many philosophical and literary speculations about these topics over time, modern science has added the curious twist of quantum theory, which requires that the elementary particles of which everything consists have no individuality at all. All aspects of chemistry depend on this lack of individuality, as do many branches of physics. From where, then, does our individuality come? In Seeing Double, Peter Pesic invites readers to explore this intriguing set of questions. He draws on literary and historical examples that open the mind (from Homer to Martin Guerre to Kafka), philosophical analyses that have helped to make our thinking and speech more precise, and scientific work that has enabled us to characterize the phenomena of nature. Though he does not try to be all-inclusive, Pesic presents a broad range of ideas, building toward a specific point of view: that the crux of modern quantum theory is its clash with our ordinary concept of individuality. This represents a departure from the usual understanding of quantum theory. Pesic argues that what is bizarre about quantum theory becomes more intelligible as we reconsider what we mean by individuality and identity in ordinary experience. In turn, quantum identity opens a new perspective on us. Peter Pesic is a Tutor and Musician-in-Residence at St. John's College, Santa Fe, New Mexico. He has a Ph.D. in physics from Stanford University.

  12. Full-counting statistics and phase transition in an open quantum system of non-interacting electrons

    NASA Astrophysics Data System (ADS)

    Medvedyeva, Mariya; Kehrein, Stefan

    2014-03-01

    We develop a method for calculating the full-counting statistics for a non-interacting fermionic system coupled to memory-less reservoirs. The evolution of the system is described by the Lindblad equation. We introduce the counting field in the Lindblad equation which yields the generating function and allows us to obtain all cumulants of the charge transport. In a uniform system the cumulants of order k are independent of the system size for systems longer than k+1 sites. The counting statistics from the Lindblad approach does not take into account the interference in the reservoirs which gives a decreased value of noise in comparison to the Green function approach which describes phase coherent leads. The two methods yield the same value for the current, which is due to current conservation. The Fano factors are different (and linearly related) and allow us to distinguish between memory-less and phase coherent reservoirs. We also consider the influence of dissipation along the chain allowing for both tunneling into and out of the chain along its length. Infinitesimally small dissipation along the chain induces a quantum phase transition which manifests itself as a discontinuity in transport properties and entropy.

  13. Bivariate distributions in statistical spectroscopy studies: III. Non interacting particle strength densities for one-body transition operators

    NASA Astrophysics Data System (ADS)

    Kota, V. K. B.; Majumdar, D.

    1995-12-01

    In statistical spectroscopy, it was shown by French et al. (Ann. Phys., N.Y. 181, 235 (1988)) that the bivariate strength densities take a convolution form with the non interacting particle (NIP) strength density being convoluted with a spreading bivariate Gaussian due to interactions. Leaving aside the question of determining the parameters of the spreading bivariate Gaussian, one needs good methods for constructing the NIP bivariate strength densities I {O/ h }( E,E') ( h is a one-body hamiltonian and O is a transition operator) in large shell model spaces. A formalism for constructing I {O/ h } is developed for one-body transition operators by using spherical orbits and spherical configurations. For rapid construction and also for applying the statistical theory in large shell model spaces I {O/ h } is decomposed into partial densities defined by unitary orbit configurations (unitary orbit is a set of spherical orbits). Trace propagation formulas for the bivariate moments M rs with r+s ≤2 of the partial NIP strength densities, which will determine the Gaussian representation, are derived. In a large space numerical example with Gamow-Teller β - transition operator, the superposition of unitary orbit partial bivariate Gaussian densities is shown to give a good representation of the exact NIP strength densities. Trace propagation formulas for M rs with r+<—4 are also derived in m-particle scalar spaces which are useful for many purposes.

  14. Double Your Major, Double Your Return?

    ERIC Educational Resources Information Center

    Del Rossi, Alison F.; Hersch, Joni

    2008-01-01

    We use the 2003 National Survey of College Graduates to provide the first estimates of the effect on earnings of having a double major. Overall, double majoring increases earnings by 2.3% relative to having a single major among college graduates without graduate degrees. Most of the gains from having a double major come from choosing fields across…

  15. Dietary Advanced Glycation End Products Consumption as a Direct Modulator of Insulin Sensitivity in Overweight Humans: A Study Protocol for a Double-Blind, Randomized, Two Period Cross-Over Trial

    PubMed Central

    de Courten, Maximilian PJ; Schalkwijk, Casper G; Walker, Karen Z; Forbes, Josephine

    2015-01-01

    Background Advanced glycation end products (AGEs) are formed during the processing, storage, and cooking of foods. As part of a western diet, AGEs are consumed in excess and impair glucose metabolism in patients with type 2 diabetes. In the absence of diabetes, AGE-mediated decreases in insulin sensitivity and signaling have been postulated. However, randomized studies to test this relationship in humans are limited. Objective The primary aim of this trial is to determine whether dietary consumption of AGEs will decrease insulin sensitivity in healthy overweight adults. A secondary aim is to determine the effects of dietary AGEs on insulin secretion, circulating soluble receptor for AGEs (sRAGE), and inflammation markers. Methods Overweight, but otherwise healthy, non-diabetic adults (N=20) aged 18-50 years old will complete a randomized cross-over design intervention study alternating low and high (4-fold increase) AGE diets (2-week duration). At baseline, participants will undergo a medical review including an intravenous glucose tolerance test (IVGTT), a hyperinsulinemic-euglycemic clamp, and anthropometric measures and questionnaires assessing diet, physical activity, and general wellness. Each test diet will be followed for 14 days, followed by a 4-week washout period before commencement of the second alternate dietary period. Energy, macronutrient, and AGE intake will be calculated for each dietary period. Additionally, the AGE content of foods used in the study will be measured by ultra performance liquid chromatography mass spectrometry. All measurements will be repeated at the beginning and end of each dietary period. Primary and secondary outcomes will be expressed as a change over the dietary period for insulin sensitivity, secretion, anthropometric parameters, sRAGE, and inflammation markers and compared by paired t test and analysis of variance (ANOVA). Results The study will be completed in early 2016. Conclusion The proposed trial will provide much

  16. Double Eclipsing Binary Fitting

    NASA Astrophysics Data System (ADS)

    Cagas, P.; Pejcha, O.

    2012-06-01

    The parameters of the mutual orbit of eclipsing binaries that are physically connected can be obtained by precision timing of minima over time through light travel time effect, apsidal motion or orbital precession. This, however, requires joint analysis of data from different sources obtained through various techniques and with insufficiently quantified uncertainties. In particular, photometric uncertainties are often underestimated, which yields too small uncertainties in minima timings if determined through analysis of a χ2 surface. The task is even more difficult for double eclipsing binaries, especially those with periods close to a resonance such as CzeV344, where minima get often blended with each other. This code solves the double binary parameters simultaneously and then uses these parameters to determine minima timings (or more specifically O-C values) for individual datasets. In both cases, the uncertainties (or more precisely confidence intervals) are determined through bootstrap resampling of the original data. This procedure to a large extent alleviates the common problem with underestimated photometric uncertainties and provides a check on possible degeneracies in the parameters and the stability of the results. While there are shortcomings to this method as well when compared to Markov Chain Monte Carlo methods, the ease of the implementation of bootstrapping is a significant advantage.

  17. Periodic Polymers

    NASA Astrophysics Data System (ADS)

    Thomas, Edwin

    2013-03-01

    Periodic polymers can be made by self assembly, directed self assembly and by photolithography. Such materials provide a versatile platform for 1, 2 and 3D periodic nano-micro scale composites with either dielectric or impedance contrast or both, and these can serve for example, as photonic and or phononic crystals for electromagnetic and elastic waves as well as mechanical frames/trusses. Compared to electromagnetic waves, elastic waves are both less complex (longitudinal modes in fluids) and more complex (longitudinal, transverse in-plane and transverse out-of-plane modes in solids). Engineering of the dispersion relation between wave frequency w and wave vector, k enables the opening of band gaps in the density of modes and detailed shaping of w(k). Band gaps can be opened by Bragg scattering, anti-crossing of bands and discrete shape resonances. Current interest is in our group focuses using design - modeling, fabrication and measurement of polymer-based periodic materials for applications as tunable optics and control of phonon flow. Several examples will be described including the design of structures for multispectral band gaps for elastic waves to alter the phonon density of states, the creation of block polymer and bicontinuous metal-carbon nanoframes for structures that are robust against ballistic projectiles and quasi-crystalline solid/fluid structures that can steer shock waves.

  18. [A double gallbladder].

    PubMed

    Mink van der Molen, A B; Salu, M K

    1991-04-06

    A 59-year-old woman is described with symptomatic cholelithiasis. A double gallbladder was incidentally found during abdominal surgery. The literature on a double gallbladder is reviewed with respect to incidence, anatomy, diagnosis and therapy.

  19. Chromosome doubling method

    DOEpatents

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  20. The double identity of linguistic doubling.

    PubMed

    Berent, Iris; Bat-El, Outi; Brentari, Diane; Dupuis, Amanda; Vaknin-Nusbaum, Vered

    2016-11-29

    Does knowledge of language consist of abstract principles, or is it fully embodied in the sensorimotor system? To address this question, we investigate the double identity of doubling (e.g., slaflaf, or generally, XX; where X stands for a phonological constituent). Across languages, doubling is known to elicit conflicting preferences at different levels of linguistic analysis (phonology vs. morphology). Here, we show that these preferences are active in the brains of individual speakers, and they are demonstrably distinct from sensorimotor pressures. We first demonstrate that doubling in novel English words elicits divergent percepts: Viewed as meaningless (phonological) forms, doubling is disliked (e.g., slaflaf < slafmak), but once doubling in form is systematically linked to meaning (e.g., slaf = ball, slaflaf = balls), the doubling aversion shifts into a reliable (morphological) preference. We next show that sign-naive speakers spontaneously project these principles to novel signs in American Sign Language, and their capacity to do so depends on the structure of their spoken language (English vs. Hebrew). These results demonstrate that linguistic preferences doubly dissociate from sensorimotor demands: A single stimulus can elicit diverse percepts, yet these percepts are invariant across stimulus modality--for speech and signs. These conclusions are in line with the possibility that some linguistic principles are abstract, and they apply broadly across language modality.

  1. Double layers and double wells in arbitrary degenerate plasmas

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2016-06-01

    Using the generalized hydrodynamic model, the possibility of variety of large amplitude nonlinear excitations is examined in electron-ion plasma with arbitrary electron degeneracy considering also the ion temperature effect. A new energy-density relation is proposed for plasmas with arbitrary electron degeneracy which reduces to the classical Boltzmann and quantum Thomas-Fermi counterparts in the extreme limits. The pseudopotential method is employed to find the criteria for existence of nonlinear structures such as solitons, periodic nonlinear structures, and double-layers for different cases of adiabatic and isothermal ion fluids for a whole range of normalized electron chemical potential, η0, ranging from dilute classical to completely degenerate electron fluids. It is observed that there is a Mach-speed gap in which no large amplitude localized or periodic nonlinear excitations can propagate in the plasma under consideration. It is further revealed that the plasma under investigation supports propagation of double-wells and double-layers the chemical potential and Mach number ranges of which are studied in terms of other plasma parameters. The Mach number criteria for nonlinear waves are shown to significantly differ for cases of classical with η0 < 0 and quantum with η0 > 0 regimes. It is also shown that the localized structure propagation criteria possess significant dissimilarities for plasmas with adiabatic and isothermal ions. Current research may be generalized to study the nonlinear structures in plasma containing positrons, multiple ions with different charge states, and charged dust grains.

  2. Double trisomy in spontaneous abortions.

    PubMed

    Reddy, K S

    1997-12-01

    Cytogenetic data on products of conception from spontaneous abortions studied over a 10-year period have been reviewed for double trisomies. A total of 3034 spontaneous abortions were karyotyped between 1986 and 1997. Twenty-two cases with double trisomy, one case with triple trisomy, and a case with a trisomy and monosomy were found. The tissues studied were mostly sac, villi, or placenta. The gestational age ranged from 6 to 11 weeks and the mean age was 8.2 +/- 1.7 (SD) weeks. The mean maternal age in years was 35.9 +/- 5.3. Of the twenty-two cases, four were mosaics. All but two of the cases involved autosomal aneuploidies. The double trisomies included chromosomes 2, 4, 5, 7, 8, 12, 13, 14, 15, 16, 17, 18, 20, 21, and 22. The chromosomes that were trisomic in more than one double trisomy case were numbers 16 (8 cases), 8 (5 cases), 15 (4 cases), 2, 13, and 21 (3 cases each), and 5, 7, 14, 18, 20, 22, and X (2 cases). The triple trisomy involved chromosomes 18, 21, and X. The monosomy and trisomy case was a mosaic, with a monosomy 21 in all cells and some cells also with a trisomy 5. The double trisomies cited for the first time in this study were 4/13, 5/16, 8/14, 8/15, 14/21, 15/20, and 7/12. The pooled mean maternal age for double trisomy cases (34.1 +/- 5.7 years) was higher than that for single trisomy cases (31 +/- 6.1 years). The difference was statistically significant at P = < 0.001. The pooled mean gestational age of spontaneous abortions was lower for double trisomy (8.7 +/- 2.2 weeks) than for reported single trisomy cases (10.1 +/- 2.9 weeks). This difference is also statistically significant at P = < 0.001. The sex ratio among double trisomies was 15 females to 13 males. This difference was not statistically significant from the expected 1:1.

  3. Observing Double Stars

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  4. Nonlinear dynamics of a double bilipid membrane.

    PubMed

    Sample, C; Golovin, A A

    2007-09-01

    The nonlinear dynamics of a biological double membrane that consists of two coupled lipid bilayers, typical of some intracellular organelles such as mitochondria or nuclei, is studied. A phenomenological free-energy functional is formulated in which the curvatures of the two parts of the double membrane and the distance between them are coupled to the lipid chemical composition. The derived nonlinear evolution equations for the double-membrane dynamics are studied analytically and numerically. A linear stability analysis is performed, and the domains of parameters are found in which the double membrane is stable. For the parameter values corresponding to an unstable membrane, numerical simulations are performed that reveal various types of complex dynamics, including the formation of stationary, spatially periodic patterns.

  5. Negatome 2.0: a database of non-interacting proteins derived by literature mining, manual annotation and protein structure analysis.

    PubMed

    Blohm, Philipp; Frishman, Goar; Smialowski, Pawel; Goebels, Florian; Wachinger, Benedikt; Ruepp, Andreas; Frishman, Dmitrij

    2014-01-01

    Knowledge about non-interacting proteins (NIPs) is important for training the algorithms to predict protein-protein interactions (PPIs) and for assessing the false positive rates of PPI detection efforts. We present the second version of Negatome, a database of proteins and protein domains that are unlikely to engage in physical interactions (available online at http://mips.helmholtz-muenchen.de/proj/ppi/negatome). Negatome is derived by manual curation of literature and by analyzing three-dimensional structures of protein complexes. The main methodological innovation in Negatome 2.0 is the utilization of an advanced text mining procedure to guide the manual annotation process. Potential non-interactions were identified by a modified version of Excerbt, a text mining tool based on semantic sentence analysis. Manual verification shows that nearly a half of the text mining results with the highest confidence values correspond to NIP pairs. Compared to the first version the contents of the database have grown by over 300%.

  6. Double mode Cepheids in M31

    SciTech Connect

    Poleski, Radosław

    2013-12-01

    Until now, double mode Cepheids (or beat Cepheids) were known only in the Galaxy, the Magellanic Clouds, and M33. Curiously, none of the more than 2000 Cepheids in M31 was claimed to show two pulsation modes. We conducted a systematic search for double mode Cepheids in the archival data of M31 and discovered four such objects. We identify one of the stars as a first and second overtone pulsator even though its secondary period is subject to strong aliasing. Two stars pulsate in the fundamental mode and the first overtone. Their fundamental periods are 9.392 days and 9.163 days. This makes them the first candidates for fundamental mode and first overtone Cepheids, of which double mode pulsations are caused by the 2:1 resonance of the fundamental mode and the second overtone.

  7. Pharmacokinetic non-interaction analysis in a fixed-dose formulation in combination of atorvastatin and ezetimibe

    PubMed Central

    Patiño-Rodríguez, Omar; Torres-Roque, Irma; Martínez-Delgado, Maricela; Escobedo-Moratilla, Abraham; Pérez-Urizar, José

    2014-01-01

    Recent clinical research has shown that atorvastatin (ATO) in combination with cholesterol absorption inhibitor ezetimibe (EZE) significantly reduces LDL-C level in patients with hypercholesterolemia, showing a superior lipid-lowering efficacy compared to statin alone. With no information currently available on the interaction between the two drugs, a pharmacokinetic study was conducted to investigate the influence of EZE on ATO and conversely when the two drugs were coadministered. The purpose of this study was to investigate the presence of differences in the pharmacokinetic profiles of capsules containing ATO 80 mg, EZE 10 mg or the combination of both 80/10 mg administered to healthy Mexican volunteers. This was a randomized, three-period, six-sequences crossover study. 36 eligible subjects aged between 20 to 50 years were included. Blood samples were collected up to 96 h after dosing, and pharmacokinetic parameters were obtained by non-compartmental analysis. Adverse events were evaluated based on subject interviews and physical examinations. Area under the concentration-time curve (AUC) and maximum plasma drug concentration (Cmax) were measured for each drug alone or together and tested for bioequivalence-based hypothesis. The estimation computed (90% confidence intervals) for AUC and Cmax, were 96.04% (85.88–107.42%) and 97.04% (82.36–114.35%), respectively for ATO–EZE combination versus ATO alone, while 84.42% (77.19–92.32%) and 95.60% (82.43–110.88%), respectively, for ATO–EZE combination versus EZE alone were estimated. These results suggest that ATO and EZE have no relevant pharmacokinetic drug–drug interaction. PMID:25505887

  8. On The Chaotic Dynamics Of Multiple Double Layers In Plasma

    SciTech Connect

    Ivan, L. M.; Chiriac, S. A.; Aflori, M.; Dimitriu, D. G.

    2007-04-23

    When a multiple double layers structure in plasma is driven far from equilibrium, it passes into a chaotic state, characterized by uncorrelated oscillations of the plasma parameters. Two scenarios of transition to chaos were identified: the Feigenbaum scenario (cascade of period doubling bifurcations) and the intermittency scenario.

  9. Emerging double helical nanostructures.

    PubMed

    Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Wei, Fei

    2014-08-21

    As one of the most important and land-mark structures found in nature, a double helix consists of two congruent single helices with the same axis or a translation along the axis. This double helical structure renders the deoxyribonucleic acid (DNA) the crucial biomolecule in evolution and metabolism. DNA-like double helical nanostructures are probably the most fantastic yet ubiquitous geometry at the nanoscale level, which are expected to exhibit exceptional and even rather different properties due to the unique organization of the two single helices and their synergistic effect. The organization of nanomaterials into double helical structures is an emerging hot topic for nanomaterials science due to their promising exceptional unique properties and applications. This review focuses on the state-of-the-art research progress for the fabrication of double-helical nanostructures based on 'bottom-up' and 'top-down' strategies. The relevant nanoscale, mesoscale, and macroscopic scale fabrication methods, as well as the properties of the double helical nanostructures are included. Critical perspectives are devoted to the synthesis principles and potential applications in this emerging research area. A multidisciplinary approach from the scope of nanoscience, physics, chemistry, materials, engineering, and other application areas is still required to the well-controlled and large-scale synthesis, mechanism, property, and application exploration of double helical nanostructures.

  10. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  11. Manual Replacement of Double J Stent Without Fluoroscopy (Double j stent replacement).

    PubMed

    Kose, Osman; Gorgel, Sacit Nuri; Ozbir, Sait; Yenigurbuz, Sekan; Kara, Cengiz

    2015-02-01

    It is not always possible to replace a ureteric stent with a new one due to the fact that tumoral effect increases in ureter with time. We present our experience of manual replacement of double J stent without fluoroscopy. The data from 23 female patients who underwent double J stent replacement with a total of 110 times was retrospectively analyzed. The steps of technique are as follows: take out distal end of the double J stent through urethra to external urethral meatus cystoscopically, insert a 0.035-inch guide wire through double J stent to the renal pelvis or intra pelvicaliceal system, take out old double J stent over guide wire, slide new stent over guide wire and at external meatus level take out guide wire while gently sliding distal end of double J stent over guide wire into urethra. The mean age was 58.39 ± 9.21 years. Cervical, endometrial, and ovarian cancer were diagnosed in 16, 4, and 3 patients respectively. The mean follow-up and indwelling period were 13.8 ± 5.2, 3.8 ± 0.6 months, respectively. Increased pelvicaliceal dilatation, serum creatinine level, or renal parenchymal loss was not observed. Replacement of double J stents with this technique is easy and can be used successfully in distal ureteral obstructions.

  12. Evolution of periodicity in periodical cicadas.

    PubMed

    Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R; Yoshimura, Jin

    2015-09-14

    Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors.

  13. Evolution of periodicity in periodical cicadas

    PubMed Central

    Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R.; Yoshimura, Jin

    2015-01-01

    Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors. PMID:26365061

  14. Double checking: a second look

    PubMed Central

    Chreim, Samia; Forster, Alan

    2015-01-01

    Abstract Rationale, aims and objectives Double checking is a standard practice in many areas of health care, notwithstanding the lack of evidence supporting its efficacy. We ask in this study: ‘How do front line practitioners conceptualize double checking? What are the weaknesses of double checking? What alternate views of double checking could render it a more robust process?’ Method This is part of a larger qualitative study based on 85 semi‐structured interviews of health care practitioners in general internal medicine and obstetrics and neonatology; thematic analysis of the transcribed interviews was undertaken. Inductive and deductive themes are reported. Results Weaknesses in the double checking process include inconsistent conceptualization of double checking, double (or more) checking as a costly and time‐consuming procedure, double checking trusted as an accepted and stand‐alone process, and double checking as preventing reporting of near misses. Alternate views of double checking that would render it a more robust process include recognizing that double checking requires training and a dedicated environment, Introducing automated double checking, and expanding double checking beyond error detection. These results are linked with the concepts of collective efficiency thoroughness trade off (ETTO), an in‐family approach, and resilience. Conclusion(s) Double checking deserves more questioning, as there are limitations to the process. Practitioners could view double checking through alternate lenses, and thus help strengthen this ubiquitous practice that is rarely challenged. PMID:26568537

  15. A novel mechanism for creating double pulsars

    NASA Technical Reports Server (NTRS)

    Sigurdsson, Steinn; Hernquist, Lars

    1992-01-01

    Simulations of encounters between pairs of hard binaries, each containing a neutron star and a main-sequence star, reveal a new formation mechanism for double pulsars in dense cores of globular clusters. In many cases, the two normal stars are disrupted to form a common envelope around the pair of neutron stars, both of which will be spun up to become millisecond pulsars. We predict that a new class of pulsars, double millisecond pulsars, will be discovered in the cores of dense globular clusters. The genesis proceeds through a short-lived double-core common envelope phase, with the envelope ejected in a fast wind. It is possible that the progenitor may also undergo a double X-ray binary phase. Any circular, short-period double pulsar found in the galaxy would necessarily come from disrupted disk clusters, unlike Hulse-Taylor class pulsars or low-mass X-ray binaries which may be ejected from clusters or formed in the galaxy.

  16. Double-helix stellarator

    SciTech Connect

    Moroz, P.E.

    1997-09-01

    A new stellarator configuration, the Double-Helix Stellarator (DHS), is introduced. This novel configuration features a double-helix center post as the only helical element of the stellarator coil system. The DHS configuration has many unique characteristics. One of them is the extreme low plasma aspect ratio, A {approx} 1--1.2. Other advantages include a high enclosed volume, appreciable rotational transform, and a possibility of extreme-high-{beta} MHD equilibria. Moreover, the DHS features improved transport characteristics caused by the absence of the magnetic field ripple on the outboard of the torus. Compactness, simplicity and modularity of the coil system add to the DHS advantages for fusion applications.

  17. Double arch mirror study

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  18. Double Photoionization Near Threshold

    NASA Technical Reports Server (NTRS)

    Wehlitz, Ralf

    2007-01-01

    The threshold region of the double-photoionization cross section is of particular interest because both ejected electrons move slowly in the Coulomb field of the residual ion. Near threshold both electrons have time to interact with each other and with the residual ion. Also, different theoretical models compete to describe the double-photoionization cross section in the threshold region. We have investigated that cross section for lithium and beryllium and have analyzed our data with respect to the latest results in the Coulomb-dipole theory. We find that our data support the idea of a Coulomb-dipole interaction.

  19. Hypokalemic periodic paralysis

    MedlinePlus

    Periodic paralysis - hypokalemic; Familial hypokalemic periodic paralysis; HOKPP; HypoKPP; HypoPP ... is not inherited. Unlike other forms of periodic paralysis, people with hypoPP have normal thyroid function. But ...

  20. Hyperkalemic periodic paralysis

    MedlinePlus

    Periodic paralysis - hyperkalemic; Familial hyperkalemic periodic paralysis; HyperKPP; HyperPP; Gamstorp disease ... factors include having other family members with periodic paralysis. It affects men more often than women.

  1. Weathering the Double Whammy.

    ERIC Educational Resources Information Center

    Wellman, Jane V.

    2002-01-01

    Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the…

  2. Sun Packs Double Punch

    NASA Video Gallery

    On August 3, the sun packed a double punch, emitting a M6.0-class flare at 9:43 am EDT. This video is of the second, slightly stronger M9.3-class flare at 11:41 pm EDT. Both flares had significant ...

  3. Rosette (Double Blossom)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rosette, or double blossom, is a serious disease of erect blackberries that is limited to the genus Rubus. Rosette may occur on trailing blackberries and dewberries, but rarely on red and black raspberries. In the United States, rosette occurs from New Jersey to Illinois and southwest to Texas and i...

  4. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, D.R.

    1982-09-23

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  5. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, Dale R.

    1984-01-01

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  6. Teaching the Double Layer.

    ERIC Educational Resources Information Center

    Bockris, J. O'M.

    1983-01-01

    Suggests various methods for teaching the double layer in electrochemistry courses. Topics addressed include measuring change in absolute potential difference (PD) at interphase, conventional electrode potential scale, analyzing absolute PD, metal-metal and overlap electron PDs, accumulation of material at interphase, thermodynamics of electrified…

  7. Design for Double Rainbow

    ERIC Educational Resources Information Center

    Thomas, Lisa Carlucci

    2011-01-01

    Rare is the inspirational, spontaneous, transformative moment shared among 20 million people. In the summer of 2010, people around the world were moved by the sighting of a double rainbow--almost a triple rainbow--"all the way across the sky" in Yosemite National Park. Caught on video and posted to by YouTube by Paul Vasquez in January 2010, the…

  8. Double Helix Revisited.

    ERIC Educational Resources Information Center

    Glickstein, Neil M.

    1995-01-01

    Describes the use of James Watson's book, "The Double Helix," as a multidisciplinary way of introducing students to actual science; the scientific method; dilemmas encountered in the world of research; and the rich setting of personalities, politics, and history in post-World War II Europe. (MKR)

  9. Double-Glazing Interferometry

    ERIC Educational Resources Information Center

    Toal, Vincent; Mihaylova, Emilia M.

    2009-01-01

    This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for…

  10. Vaginal bleeding between periods

    MedlinePlus

    ... periods; Intermenstrual bleeding; Spotting; Metrorrhagia Images Female reproductive anatomy Bleeding between periods Uterus References Bulun SE. The physiology and pathology of the female reproductive axis. In: ...

  11. Memory, double, shadow, and evil.

    PubMed

    McNamara, P

    1994-04-01

    In order to examine shadow dynamics the author explores the phenomenology and mythological associations of the 'double' or Doppelgänger. Current Jungian-inspired theories concerning relations of shadow and double are found to be limited because they do not explain (1) the process of personification of the psychic complex which gives rise to the double, (2) the immediate conditions under which doubling occurs, (3) the conditions which lead to the assignment of evil qualities to the double as shadow. The paper seeks to remedy each of the above limitations by redescribing shadow/double phenomena in terms of autonomous memory phenomena, both personal and trans-personal.

  12. Double Degrees: Double the Trouble or Twice the Return?

    ERIC Educational Resources Information Center

    Russell, A. Wendy; Dolnicar, Sara; Ayoub, Marina

    2008-01-01

    Double degrees (also called joint or combined degrees)--programs of study combining two bachelor degrees--are increasingly popular in Australian universities, particularly among women. A case study using qualitative and quantitative surveys of current and past double degree students is presented. The study indicates that double degrees benefit…

  13. Tests on Double Layer Metalization

    NASA Technical Reports Server (NTRS)

    Woo, D. S.

    1983-01-01

    28 page report describes experiments in fabrication of integrated circuits with double-layer metalization. Double-layer metalization requires much less silicon "real estate" and allows more flexibility in placement of circuit elements than does single-layer metalization.

  14. Non-interacting Neél-Brown or interacting Vogel-Fulcher models in magnetic CoFe2-xGdxO4 nanocrystals

    NASA Astrophysics Data System (ADS)

    Sodaee, Tahmineh; Ghasemi, Ali; Razavi, Reza Shoja

    2016-11-01

    CoFe2-xGdxO4 (x=0-0.04 in a step of 0.01) ferrite nanocrystals were synthesized by a hydrothermal technique. The X-ray diffraction analysis indicated that single phase spinel ferrites were obtained. The XRD data were processed for Rietveld refinement of structure by Reflex program. The FE-SEM micrographs of the synthesized samples showed the presence of polyhedral-shaped grains. The gadolinium cations substitution greatly influenced the DC electrical resistivity of the synthesized nanocrystals. With an increase in gadolinium content, the electrical resistivity decreased from 1009.667 Ω-cm for x=0 to 6.397 Ω-cm for x=0.02. The results of magnetic hysteresis at a room temperature demonstrated that with an increase in gadolinium content, the coercive field increased from 664.6 Oe for x=0 to 2069 Oe for x=0.02. In addition, it was found that with substitutions of gadolinium cations, the values of saturation magnetization decreased from 104.17 emu/g for x=0 to 83.3 emu/g for x=0.02. It is also observed from the loop that with substitutions of gadolinium cations at higher contents in the composition (x>0.02), the coercive field decreased while the values of saturation magnetization increased. The variation of magnetization versus temperature for determining Curie temperature shows the increasing trend with Gd3+ substitution, indicating the strengthening in A-B interactions. Magnetic dynamics of the samples was also studied by measuring AC magnetic susceptibility versus temperature. The phenomenological Neél-Brown and Vogel-Fulcher models were used to distinguish between the interacting or non-interacting system.

  15. Measuring the Double Helix

    SciTech Connect

    Mathew-Fenn, R.S.; Das, R.; Harbury, P.A.B.

    2009-05-26

    DNA is thought to behave as a stiff elastic rod with respect to the ubiquitous mechanical deformations inherent to its biology. To test this model at short DNA lengths, we measured the mean and variance of end-to-end length for a series of DNA double helices in solution, using small-angle x-ray scattering interference between gold nanocrystal labels. In the absence of applied tension, DNA is at least one order of magnitude softer than measured by single-molecule stretching experiments. Further, the data rule out the conventional elastic rod model. The variance in end-to-end length follows a quadratic dependence on the number of base pairs rather than the expected linear dependence, indicating that DNA stretching is cooperative over more than two turns of the DNA double helix. Our observations support the idea of long-range allosteric communication through DNA structure.

  16. Algebra of Majorana doubling.

    PubMed

    Lee, Jaehoon; Wilczek, Frank

    2013-11-27

    Motivated by the problem of identifying Majorana mode operators at junctions, we analyze a basic algebraic structure leading to a doubled spectrum. For general (nonlinear) interactions the emergent mode creation operator is highly nonlinear in the original effective mode operators, and therefore also in the underlying electron creation and destruction operators. This phenomenon could open up new possibilities for controlled dynamical manipulation of the modes. We briefly compare and contrast related issues in the Pfaffian quantum Hall state.

  17. Particle simulation for accretion sheets in narrow double stars

    NASA Astrophysics Data System (ADS)

    Geyer, F.; Herold, H.; Ruder, H.

    1988-11-01

    Development and behavior of accretion sheets in double stars systems are studied by particle simulation calculations. Numerical analysis considers the following parameters in the binary system: primary and secondary components, path period of the system, and mass flow rates. Mass behavior is described by Roche-potential. The particle motion equation in the double star system is solved by the Leap-Frog procedure. Velocity friction simulation is obtained by viscous interaction considerations.

  18. Colloidal Double Quantum Dots

    PubMed Central

    2016-01-01

    Conspectus Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole–dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single

  19. Colloidal Double Quantum Dots.

    PubMed

    Teitelboim, Ayelet; Meir, Noga; Kazes, Miri; Oron, Dan

    2016-05-17

    Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole-dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single photon

  20. [Clinical experience of automated double filtration plasmapheresis].

    PubMed

    Lee, C T; Chuang, F R; Hsu, K T; Lam, K K; Liao, S C; Liu, C C; Chen, J B; Jang, S W; Chien, Y S; Pan, H H

    1996-12-01

    Double filtration plasmapheresis, one kind of fractionation plasmapheresis, was developed from membrane type plasmapheresis to remove only the pathogen and return the normal protein back to the patient. We started our automated double filtration plasmapheresis since December 1993. There were 13 patients who received one hundred treatments totally during one year period. And they are myasthenia gravis (8 patients); acute inflammatory demyelinating polyneuropathy (1 patient), multiple myeloma (1 patient); acquired factor VIII inhibitor (1 patient); autoimmune hemolytic anemia (1 patient); systemic lupus erythematous (1 patient). Technically double filtration plasmapheresis is easy to perform and time-saving. It also makes necessity of replacement fluid less frequent. Incidence of complication is rare, and this includes hypotension 2%, palpitation 1%, headache 1%, hemolysis 4%, air emboli 1%, high secondary pressure 2%, and no motality during our treatment. Clinical response is documented in cases of myasthenia gravis; acute inflammatory demyelinating polyneuropathy and acquired factor VIII inhibitor in our study. In conclusion, double filtration plasmapheresis is a time-saving, convenient, and safe therapeutic modality with rare complication. Because its effectiveness on limited kinds of diseases and costs relatively high price, thus plasmapheresis should be used in selected cases and treat aggressively if indicated.

  1. Period meter for reactors

    DOEpatents

    Rusch, Gordon K.

    1976-01-06

    An improved log N amplifier type nuclear reactor period meter with reduced probability for noise-induced scrams is provided. With the reactor at low power levels a sampling circuit is provided to determine the reactor period by measuring the finite change in the amplitude of the log N amplifier output signal for a predetermined time period, while at high power levels, differentiation of the log N amplifier output signal provides an additional measure of the reactor period.

  2. The Periodic Pyramid

    ERIC Educational Resources Information Center

    Hennigan, Jennifer N.; Grubbs, W. Tandy

    2013-01-01

    The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…

  3. Community College Periodicals.

    ERIC Educational Resources Information Center

    Pederson, Eldor O.

    Drawing from an examination of community college periodicals, their availability and characteristics, the academic affiliations of contributing authors, and the topics of their articles, this paper discusses the minor role which community college periodicals appear to play. A list of 35 periodicals dealing primary with community college education…

  4. Double reference pulsed phase locked loop

    NASA Technical Reports Server (NTRS)

    Heyman, J. S. (Inventor)

    1986-01-01

    A double reference pulse phase locked loop is described which measures the phase shift between tone burst signals initially derived from the same periodic signal source (voltage controlled oscillator) and delayed by different amounts because of two different paths. A first path is from the transducer to the surface of a sample and back. A second path is from the transducer to the opposite surface and back. A first pulse phase locked loop including a phase detector and a phase shifter forces the tone burst signal delayed by the second path in phase quadrature with the periodic signal source. A second pulse phase locked loop including a second phase detector forces the tone burst signals delayed by the first path into phase quadrature with the phase shifted periodic signal source.

  5. Tidal Effects in Inspiraling Double White Dwarfs

    NASA Astrophysics Data System (ADS)

    Willems, B.; Kalogera, Vicky; Vecchio, A.; Ivanova, N.; Deloye, C.; Hansen, B.

    2006-12-01

    Despite the overwhelming abundance of double white dwarfs in the LISA gravitational wave frequency band, modeling of their waveforms has remained limited to the point-mass approximation in which gravitational radiation is the only source of systemic orbital angular momentum loss. As a significant fraction of these systems spirals in to periods as short as 5-10 minutes, tidal effects can, however, play an important role in modifying the gravitational wave frequency evolution. The strength of the tidal effects depends strongly on the energy dissipation mechanism damping the tides, which, for white dwarfs, is highly uncertain. In this poster, we present the first results of a systematic study of tidal dissipation in white dwarfs, and the impact of tides on the gravitational wave signal of close double white dwarfs.

  6. Double complexes and local cochain projections

    PubMed Central

    Falk, Richard S; Winther, Ragnar

    2015-01-01

    The construction of projection operators, which commute with the exterior derivative and at the same time are bounded in the proper Sobolev spaces, represents a key tool in the recent stability analysis of finite element exterior calculus. These so-called bounded cochain projections have been constructed by combining a smoothing operator and the unbounded canonical projections defined by the degrees of freedom. However, an undesired property of these bounded projections is that, in contrast to the canonical projections, they are nonlocal. The purpose of this article is to discuss a recent alternative construction of bounded cochain projections, which also are local. A key tool for the new construction is the structure of a double complex, resembling the Čech-de Rham double complex of algebraic topology. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 541–551, 2015 PMID:25914441

  7. Numerical Continuation of Hamiltonian Relative Periodic Orbits

    NASA Astrophysics Data System (ADS)

    Wulff, Claudia; Schebesch, Andreas

    2008-08-01

    The bifurcation theory and numerics of periodic orbits of general dynamical systems is well developed, and in recent years, there has been rapid progress in the development of a bifurcation theory for dynamical systems with structure, such as symmetry or symplecticity. But as yet, there are few results on the numerical computation of those bifurcations. The methods we present in this paper are a first step toward a systematic numerical analysis of generic bifurcations of Hamiltonian symmetric periodic orbits and relative periodic orbits (RPOs). First, we show how to numerically exploit spatio-temporal symmetries of Hamiltonian periodic orbits. Then we describe a general method for the numerical computation of RPOs persisting from periodic orbits in a symmetry breaking bifurcation. Finally, we present an algorithm for the numerical continuation of non-degenerate Hamiltonian relative periodic orbits with regular drift-momentum pair. Our path following algorithm is based on a multiple shooting algorithm for the numerical computation of periodic orbits via an adaptive Poincaré section and a tangential continuation method with implicit reparametrization. We apply our methods to continue the famous figure eight choreography of the three-body system. We find a relative period doubling bifurcation of the planar rotating eight family and compute the rotating choreographies bifurcating from it.

  8. Firewalls from double purity

    NASA Astrophysics Data System (ADS)

    Bousso, Raphael

    2013-10-01

    The firewall paradox is often presented as arising from double entanglement, but I argue that more generally the paradox is double purity. Near-horizon modes are purified by the interior, in the infalling vacuum. Hence, they cannot also be pure alone, or in combination with any third system, as demanded by unitarity. This conflict arises independently of the Page time, for entangled and for pure states. It implies that identifications of Hilbert spaces cannot resolve the paradox. Traditional complementarity requires the unitary identification of infalling matter with a scrambled subsystem of the Hawking radiation. Extending this map to the infalling vacuum overdetermines the out-state. More general complementarity maps (“A=RB,” “ER=EPR”) necessarily fail when the near-horizon zone is pure. I argue that pure-zone states span the microcanonical ensemble, and that this suffices to make the horizon a special place. I advocate that the ability to detect the horizon locally, rather than the degree or probability of violence, is what makes firewalls problematic. Conversely, if the production of matter at the horizon can be dynamically understood and shown to be consistent, then firewalls do not constitute a violation of the equivalence principle.

  9. On the trail of double peak hydrographs

    NASA Astrophysics Data System (ADS)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; François Iffly, Jean; McDonnell, Jeffrey J.; Pfister, Laurent

    2016-04-01

    and the plateau) equally contribute to the generation of delayed peaks in double peak hydrographs. We found evidence of catchment storage being a dominant control on the delayed peak activation. The amount of this storage threshold was consistent over a 3-year period. Hillslopes were connected to the stream at low discharge values, whereas the plateau contribution to discharge was significant when storage reached a certain threshold value. The latter seems to trigger the generation of the delayed peak in the double peak events. We also observed a non-linear relationship between storage and discharge, which leads to hysteretic relationships between both variables. During single peak hydrographs and first peaks in double peak hydrographs discharge increases faster and peaks before catchment storage, resulting in counter-clockwise hysteretic loops. This was explained by the fact that these runoff peaks are generated by precipitation falling directly into the stream or near stream locations, and/or by the contribution of water flowing through preferential flowpaths that quickly reached the stream network. When catchment storage exceeded the threshold for the generation of double peak hydrographs, events showed clockwise hysteretic loops. It is the stored water in the catchment that will peak first and consequently generate the delayed peak in the hydrograph as a result of the capacity exceedance of a subsurface storage.

  10. Periodic chiral structures

    NASA Technical Reports Server (NTRS)

    Jaggard, Dwight L.; Engheta, Nader; Pelet, Philippe; Liu, John C.; Kowarz, Marek W.; Kim, Yunjin

    1989-01-01

    The electromagnetic properties of a structure that is both chiral and periodic are investigated using coupled-mode equations. The periodicity is described by a sinusoidal perturbation of the permittivity, permeability, and chiral admittance. The coupled-mode equations are derived from physical considerations and used to examine bandgap structure and reflected and transmitted fields. Chirality is observed predominantly in transmission, whereas periodicity is present in both reflection and transmission.

  11. Apple Valley Double Star Workshop

    NASA Astrophysics Data System (ADS)

    Brewer, Mark

    2015-05-01

    The High Desert Astronomical Society hosts an annual double star workshop, where participants measure the position angles and separations of double stars. Following the New Generation Science Standards (NGSS), adopted by the California State Board of Education, participants are assigned to teams where they learn the process of telescope set-up and operation, the gathering of data, and the reduction of the data. Team results are compared to the latest epoch listed in the Washington Double Star Catalog (WDS) and papers are written for publication in the Journal of Double Star Observations (JDSO). Each team presents a PowerPoint presentation to their peers about actual hands-on astronomical research.

  12. Colored Flag by Double Refraction.

    ERIC Educational Resources Information Center

    Reid, Bill

    1994-01-01

    Describes various demonstrations that illustrate double refraction and rotation of the plane of polarization in stressed, transparent plastics, with the consequent production of colored designs. (ZWH)

  13. Periodic Solutions of Spatially Periodic Hamiltonian Systems

    DTIC Science & Technology

    1989-07-10

    Theorem 0.2 generalizes Theorem 1.5 of Rabinowitz in [201. 3 Equation (0.1), under spatially periodic assumptions has been studied by several au...n x n symmetric matrix, H satisfying (HO), (H1) and (H2), and f = (0, fq) satisfying (fM), (fl) and (f2), Rabinowitz in [201 showed the existence of... Rabinowitz [17]. We consider a functional I : E x M ) R of class C’, where E is a Hilbert space and M is a compact manifold. Assuming that I satisfies a

  14. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2007-06-01

    The recent results showing the presence of neutrino oscillations clearly indicate that the difference between the squared mass of neutrinos of different flavors is different from zero, but are unable to determine the nature and the absolute value of the neutrino mass. Neutrinoless double beta decay (DBD) is at present the most powerful tool to ascertain if the neutrino is a Majorana particle and to determine under this condition the absolute value of its mass. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is Dirac or Majorana particle.

  15. Double beta decay: Calorimeters

    NASA Astrophysics Data System (ADS)

    Brofferio, Chiara

    2008-11-01

    Calorimeters or, with a more specific definition, low temperature detectors, have been used by now for more than 15 years in Double Beta Decay (DBD) searches, with excellent results: they compete with Ge diodes for the rank of detectors with the highest sensitivity to the effective neutrino mass, which is defined as a linear combination of the neutrino mass eigenvalues. After a brief introduction to the argument, with some notes on DBD and on bolometers, an update on the now closed experiment CUORICINO and on its successor, CUORE, is given. The fundamental role of background is then revealed and commented, introducing in this way the importance of the specific experiment now under construction, CUORE-0, that will precede CUORE to help optimizing the struggle against surface background. The possible future of this technique is then commented, quoting important R&D studies that are going on, for active shielding bolometers and for scintillating bolometers coupled with light detecting bolometers.

  16. Double integrated laser interferometer

    NASA Astrophysics Data System (ADS)

    Motyka, Zbigniew

    2003-10-01

    The layout of integrated optical system compromising the basis of proposed solution of double laser interferometer composed of two integrated Michelson's interferometers is presented and shortly discussed. Such an integrated system is designed for work with two lasers of different wavelength. It may serve for mapping surfaces and deformations of objects under investigation with the use of simultaneous recording of two mutually orthogonal gratings, each one composed of equidistant, parallel interference fringes projected onto the surface of such an object. The picture resulting two-coloured is recorded with the digital camera and may be used for obtaining these maps and deformations directly or in the indirect way after suitable digital processing applied to each colour component separately.

  17. The double contact nature of TT Herculis

    SciTech Connect

    Terrell, Dirk; Nelson, Robert H. E-mail: bob.nelson@shaw.ca

    2014-03-01

    We present new radial velocities and photometry of the short-period Algol TT Herculis. Previous attempts to model the light curves of the system have met with limited success, primarily because of the lack of a reliable mass ratio. Our spectroscopic observations are the first to result in radial velocities for the secondary star, and thus provide a spectroscopic mass ratio. Simultaneous analysis of the radial velocities and new photometry shows that the system is a double contact binary, with a rapidly rotating primary that fills its limiting lobe.

  18. The Living Periodic Table

    ERIC Educational Resources Information Center

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  19. Latent Period of Relaxation.

    PubMed

    Kobayashi, M; Irisawa, H

    1961-10-27

    The latent period of relaxation of molluscan myocardium due to anodal current is much longer than that of contraction. Although the rate and the grade of relaxation are intimately related to both the stimulus condition and the muscle tension, the latent period of relaxation remains constant, except when the temperature of the bathing fluid is changed.

  20. Periodic Patterns in Distributions of Peptide Masses

    PubMed Central

    Hubler, Shane L.; Craciun, Gheorghe

    2015-01-01

    We are investigating the distribution of the number of peptides for given masses, and especially the observation that peptide density reaches a local maximum approximately every 14 Daltons. This wave pattern exists across species (e.g. human or yeast) and enzyme digestion techniques. To analyze this phenomenon we have developed a mathematical method for computing the mass distributions of peptides, and we present both theoretical and empirical evidence that this 14-Dalton periodicity does not arise from species selection of peptides but from the number-theoretic properties of the masses of amino acid residues. We also describe other, more subtle periodic patterns in the distribution of peptide masses. We also show that these periodic patterns are robust under a variety of conditions, including the addition of amino acid modifications and selection of mass accuracy scale. The method used here is also applicable to any family of sequential molecules, such as linear hydrocarbons, RNA, single- and double-stranded DNA. PMID:22579741

  1. Double groove broadband gratings.

    PubMed

    Pietarinen, Juha; Vallius, Tuomas

    2008-09-01

    Waveguiding in periodical structures of the size of the wavelength is applied to increase the functional spectral band of diffractive optics. The deviation of the effective refractive index between waveguides as a function of the wavelength is utilized to compensate the strong wavelength dependence of the efficiency of diffraction gratings.

  2. A Shifted Double-Diamond Titania Scaffold.

    PubMed

    Li, Hong; Liu, Ye; Cao, Xin; Han, Lu; Jiang, Chun; Che, Shunai

    2017-01-16

    Photonic crystals are expected to be metamaterials because of their potential to control the propagation of light in the linear and nonlinear regimes. Biological single-network, triply periodic constant mean curvature surface structures are considered excellent candidates owing to their large complete band gap. However, the chemical construction of these relevant structures is rare and developing new structures from thermodynamically stable double-network self-organizing systems is challenging. Herein, we reveal that the shifted double-diamond titania scaffold can achieve a complete band gap. The largest (7.71 %) band gap is theoretically obtained by shifting 0.332 c with the dielectric contrast of titania (6.25). A titania scaffold with similar shifted double-diamond structure was fabricated using a reverse core-shell microphase-templating system with an amphiphilic diblock copolymer and a titania source in a mixture of tetrahydrofuran and water, which could result in a 2.05-3.78 % gap.

  3. Empirically Unbinding the Double Bind.

    ERIC Educational Resources Information Center

    Olson, David H.

    The theoretical concept of the double bind and the possibilities for researching it are discussed. The author has observed that theory and research, which should be reciprocal and mutually beneficial, have been working, as concerns the double bind, at odds with one another. Two approaches to empirically investigating the concept are considered via…

  4. Genealogy of periodic trajectories

    SciTech Connect

    de Adguiar, M.A.M.; Maldta, C.P.; de Passos, E.J.V.

    1986-05-20

    The periodic solutions of non-integrable classical Hamiltonian systems with two degrees of freedom are numerically investigated. Curves of periodic families are given in plots of energy vs. period. Results are presented for this Hamiltonian: H = 1/2(p/sub x//sup 2/ + p/sub y//sup 2/) + 1/2 x/sup 2/ + 3/2 y/sup 2/ - x/sup 2/y + 1/12 x/sup 4/. Properties of the families of curves are pointed out. (LEW)

  5. Periodically poled silicon

    NASA Astrophysics Data System (ADS)

    Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Jalali, Bahram

    2009-03-01

    We propose a new class of photonic devices based on periodic stress fields in silicon that enable second-order nonlinearity as well as quasi-phase matching. Periodically poled silicon (PePSi) adds the periodic poling capability to silicon photonics and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on second-order nonlinear effects. As an example of the utility of the PePSi technology, we present simulations showing that midwave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50%.

  6. Double valve Implantation

    PubMed Central

    Stassano, Paolo; Mannacio, Vito; Musumeci, Antonino; Golino, Alessandro; Maida, Piero; Ferrigno, Vincenzo; Buonocore, Gaetano; Spampinato, Nicola

    1991-01-01

    From January 1976 through December 1987, 194 patients with a mean age of 43.3 ± 13.7 years (range, 11 to 74 years) underwent double (mitral and aortic) replacement of native valves with 8 types of bioprostheses: Carpentier-Edwards, 127 valves; Hancock, 76 valves; Liotta-Bioimplant, 57 valves; Ionescu-Shiley, 53 valves; Vascor, 27 valves; Carpentier-Edwards Pericardial, 22 valves; Angell-Shiley, 20 valves; and Implamedic, 6 valves. Concomitant cardiac procedures were performed in 25 patients (12.8%). There were 18 operative deaths (9.27%). Our retrospective analysis was restricted to 352 bioprostheses implanted in the 176 patients who survived surgery and were considered at risk for valve tissue failure. The overall cumulative duration of follow-up was 1,174.1 patient-years (range, 1 to 13 years). The durations of follow-up for specific valves were: Carpentier-Edwards, 920.2 valve-years; Hancock, 383.8 valve-years; Liotta-Bioimplant, 310.2 valve-years; Ionescu-Shiley, 357.7 valve-years; Vascor, 131.2 valve-years; Carpentier-Edwards Pericardial, 52.0 valve-years; Angell-Shiley, 167.0 valve-years; and Implamedic, 31.0 valve-years. Thirty patients had thromboembolic accidents, for a linearized incidence of 2.5% per patient-year. At 13 years, the actuarial freedom from thromboembolic accidents was 85.8% ± 10.7%. Nine patients had endocarditis, for a linearized incidence of 0.7% per patient-year. At 13 years, the actuarial freedom from endocarditis was 92.0% ± 1.5%. Twenty-four patients had valve tissue failure, for a cumulative linearized incidence of 1.87% per valve-year. The cumulative actuarial probability of freedom from valve tissue failure was 78.6% ± 3.7% at 10 years and 51.2% ± 10.7% at 13 years. The 24 patients with valve tissue failure all underwent reoperation: 20 of these had double valve replacement, 3 had aortic valve replacement alone, and 1 had mitral valve replacement alone. The mean interval between initial valve implantation and reoperation was

  7. Theory of nonmonotonic double layers

    SciTech Connect

    Kim, K.Y.

    1987-12-01

    A simple graphic method of solving the Vlasov--Poisson system associated with nonlinear eigenvalue conditions for arbitrary potential structures is presented. A general analytic formulation for nonmonotonic double layers is presented and illustrated with some particular closed form solutions. This class of double layers satisfies the time stationary Vlasov--Poisson system while requiring a Sagdeev potential, which is a double-valued function of the physical potential. It follows that any distribution function having a density representation as any integer or noninteger power series of potential can never satisfy the nonmonotonic double-layer boundary conditions. A Korteweg--de Vries-like equation is found showing a relationship among the speed of the nonmonotonic double layer, its scale length, and its degree of asymmetry.

  8. The Visual Double Star Catalogs

    NASA Astrophysics Data System (ADS)

    Mason, Brian D.

    2015-08-01

    In visual double star work, production of the first comprehensive attempt to list all discovered pairs in his accessible sky was prepared by S.W. Burnham in 1906. A double star catalog for the southern hemisphere was prepared by R.T.A. Innes et al. in 1927 and the northern hemisphere catalog was updated by R.G. Aitken and E. Doolittle in 1932. Eventually, this led to Lick Observatory maintaining what became known as the Index Catalogue, an all-sky visual double star database.In 1964, under the aegis of Commission 26, the Lick double star database was transferred to the U.S. Naval Observatory where it was redesignated the Washington Double Star Catalog where it and it's ancillary catalogs, have been maintained for over half a century. The current statistics of the catalog and it's supplements are presented as are the enhancements currently under consideration.

  9. Echelle Spectroscopy of Double-Mode Cepheids

    NASA Astrophysics Data System (ADS)

    Sziládi, K.; Vinkó, J.; Poretti, E.; Szabados, L.; Kun, M.

    2006-04-01

    We have obtained high-resolution (R ˜ 48000) spectra of thirteen southern double-mode Cepheids using the FEROS spectrograph at the 2.20-m telescope on La Silla with a signal-to-noise ratio of about 200 to 350. The aim of the project is to specify physical parameters (chemical abundance, gravity and temperature) and evolutionary status of beat Cepheids. We present the method of the detailed spectroscopic investigation and its application to EY Car. We intend to refine the existing period ratio -- metallicity relations. This new calibration may allow us to determine whether metallicities smaller than the solar value are the actual reasons for the observed period ratios of the galactic Cepheids.

  10. Setting the Periodic Table.

    ERIC Educational Resources Information Center

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  11. The Periodic Table CD.

    ERIC Educational Resources Information Center

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  12. Antarctic radiation exposure doubles

    NASA Astrophysics Data System (ADS)

    Blue, Charles

    New data reveal that the Antarctic Peninsula received twice its normal maximum dose of hazardous solar ultraviolet radiation in December 1990. The prolonged persistence of the ozone hole over Antarctica caused an increased exposure of radiation, according to a paper published in the October issue of Geophysical Research Letters.John Frederick and Amy D. Alberts of the University of Chicago calculated the amount of ultraviolet solar spectral radiation from data collected at Palmer Station, Antarctica. During the spring of 1990 the largest observed values for ultraviolet radiation were approximately double the values expected, based on previous years. “The measurements from Palmer Station are consistent with similar data from McMurdo Sound, where a factor of three [ultraviolet radiation] enhancement was recorded, according to work by Knut Stamnes and colleagues at the University of Alaska,” Frederick said. “The radiation levels observed over Palmer Station in December 1990 may be the largest experienced in this region of the world since the development of the Earth's ozone layer,” he added.

  13. Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2010-12-01

    Almost exactly seventy years ago and only one year before his tragic disappearance the ingenious idea of Ettore Majorana is becoming one of the most important step in the development of fundamental physics. The problem of the nature of the neutrino, namely if it is a massless Dirac particle different from its antineutrino or a Majorana particle with finite mass, is discussed. In fact the recent results showing the presence of neutrino oscillations clearly indicates that the difference between the squared mass of neutrinos of different flavours is finite. Neutrinoless double beta decay (DBD) is at present the most powerful tool to determine the effective value of the mass of a Majorana neutrino. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already at least partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is indeed a Majorana particle.

  14. Double Diffusive Plumes

    NASA Astrophysics Data System (ADS)

    Sutherland, Bruce; Lee, Brace

    2008-11-01

    Sour gas flares attempt to dispose of deadly H2S gas through combustion. What does not burn rises as a buoyant plume. But the gas is heavier than air at room temperature, so as the rising gas cools eventually it becomes negatively buoyant and descends back to the ground. Ultimately, our intent is to predict the concentrations of the gas at ground level in realistic atmospheric conditions. As a first step towards this goal we have performed laboratory experiments examining the structure of a steady state plume of hot and salty water that rises buoyantly near the source and descends as a fountain after it has cooled sufficiently. We call this a double-diffusive plume because its evolution is dictated by the different (turbulent) diffusivities of heat and salt. A temperature and conductivity probe measures both the salinity and temperature along the centreline of the plume. The supposed axisymmetric structure of the salinity concentration as it changes with height is determined by light-attenuation methods. To help interpret the results, a theory has been successfully adapted from the work of Bloomfield and Kerr (2000), who developed coupled equations describing the structure of fountains. Introducing a new empirical parameter for the relative rates of turbulent heat and salt diffusion, the predictions are found to agree favourably with experimental results.

  15. Double acting bit holder

    DOEpatents

    Morrell, Roger J.; Larson, David A.; Ruzzi, Peter L.

    1994-01-01

    A double acting bit holder that permits bits held in it to be resharpened during cutting action to increase energy efficiency by reducing the amount of small chips produced. The holder consist of: a stationary base portion capable of being fixed to a cutter head of an excavation machine and having an integral extension therefrom with a bore hole therethrough to accommodate a pin shaft; a movable portion coextensive with the base having a pin shaft integrally extending therefrom that is insertable in the bore hole of the base member to permit the moveable portion to rotate about the axis of the pin shaft; a recess in the movable portion of the holder to accommodate a shank of a bit; and a biased spring disposed in adjoining openings in the base and moveable portions of the holder to permit the moveable portion to pivot around the pin shaft during cutting action of a bit fixed in a turret to allow front, mid and back positions of the bit during cutting to lessen creation of small chip amounts and resharpen the bit during excavation use.

  16. Laser double Doppler flowmeter

    NASA Astrophysics Data System (ADS)

    Poffo, L.; Goujon, J.-M.; Le Page, R.; Lemaitre, J.; Guendouz, M.; Lorrain, N.; Bosc, D.

    2014-05-01

    The Laser Doppler flowmetry (LDF) is a non-invasive method for estimating the tissular blood flow and speed at a microscopic scale (microcirculation). It is used for medical research as well as for the diagnosis of diseases related to circulatory system tissues and organs including the issues of microvascular flow (perfusion). It is based on the Doppler effect, created by the interaction between the laser light and tissues. LDF measures the mean blood flow in a volume formed by the single laser beam, that penetrate into the skin. The size of this measurement volume is crucial and depends on skin absorption, and is not directly reachable. Therefore, current developments of the LDF are focused on the use of always more complex and sophisticated signal processing methods. On the other hand, laser Double Doppler Flowmeter (FL2D) proposes to use two laser beams to generate the measurement volume. This volume would be perfectly stable and localized at the intersection of the two laser beams. With FL2D we will be able to determine the absolute blood flow of a specific artery. One aimed application would be to help clinical physicians in health care units.

  17. Dichlorphenamide: A Review in Primary Periodic Paralyses.

    PubMed

    Greig, Sarah L

    2016-03-01

    Oral dichlorphenamide (Keveyis™) is a carbonic anhydrase inhibitor that is approved in the USA for the treatment of primary hyperkalaemic and hypokalaemic periodic paralyses and related variants. The efficacy and safety of dichlorphenamide in patients with primary periodic paralyses have been evaluated in four 9-week, randomized, double-blind, placebo-controlled, phase III trials [two parallel-group trials (HOP and HYP) and two crossover trials]. In two trials in patients with hypokalaemic periodic paralysis, dichlorphenamide was associated with a significantly (eightfold) lower paralytic attack rate and fewer patients with acute intolerable worsening compared with placebo. In two trials in patients with hyperkalaemic periodic paralysis, the attack rate was lower with dichlorphenamide than placebo, with this comparison reaching statistical significance in one trial (crossover) but not the other (HYP), although the attack rate was approximately fivefold lower with dichlorphenamide than placebo in the HYP trial. In 52-week, open-label extensions of the HOP and HYP trials, dichlorphenamide provided sustained efficacy in patients with hypokalaemic or hyperkalaemic periodic paralysis. Dichlorphenamide was generally well tolerated in all four phase III trials and during the extension trials; the most common adverse events were paraesthesia, cognitive disorders and dysgeusia. As the first agent to be approved in the USA for this indication, dichlorphenamide is a valuable treatment option for patients with primary hyperkalaemic or hypokalaemic periodic paralysis.

  18. Advanced double layer capacitors

    NASA Technical Reports Server (NTRS)

    Sarangapani, S.; Lessner, P.; Forchione, J.; Laconti, A. B.

    1989-01-01

    There is a need for large amounts of power to be delivered rapidly in a number of airborne and space systems. Conventional, portable power sources, such as batteries, are not suited to delivering high peak power pulses. The charge stored at the electrode-electrolyte double layer is, however, much more assessible on a short time scale. Devices exploiting this concept were fabricated using carbon and metal oxides (Pinnacle Research) as the electrodes and sulfuric acid as the electrolyte. The approach reported, replaces the liquid sulfuric acid electrolyte with a solid ionomer electrolyte. The challenge is to form a solid electrode-solid ionomer electrolyte composite which has a high capacitance per geometric area. The approach to maximize contact between the electrode particles and the ionomer was to impregnate the electrode particles using a liquid ionomer solution and to bond the solvent-free structure to a solid ionomer membrane. Ruthenium dioxide is the electrode material used. Three strategies are being pursued to provide for a high area electrode-ionomer contact: mixing of the RuOx with a small volume of ionomer solution followed by filtration to remove the solvent, and impregnation of the ionomer into an already formed RuOx electrode. RuOx powder and electrodes were examined by non-electrochemical techniques. X-ray diffraction has shown that the material is almost pure RuO2. The electrode structure depends on the processing technique used to introduce the Nafion. Impregnated electrodes have Nafion concentrated near the surface. Electrodes prepared by the evaporation method show large aggregates of crystals surrounded by Nafion.

  19. The Double Chooz Outer Veto

    NASA Astrophysics Data System (ADS)

    Toups, Matthew

    2009-05-01

    Measuring a non-zero value for the neutrino mixing angle θ13 sets the scale for future precision measurements in the lepton sector such as CP violation. The Double Chooz experiment will begin taking data later this year with a sensitivity to 2̂(2θ13) in the 0.02 - 0.03 range, improving on the CHOOZ bound by about an order of magnitude. Efficient rejection of backgrounds induced by cosmic muons is essential to achieving this sensitivity. The Double Chooz Outer Veto plays a crucial role in vetoing and tagging these muons. An update on the status of the Double Chooz Outer Veto will be presented.

  20. Aspects of the doubled worldsheet

    NASA Astrophysics Data System (ADS)

    Driezen, Sibylle; Sevrin, Alexander; Thompson, Daniel C.

    2016-12-01

    We clarify the relation between various approaches to the manifestly T-duality symmetric string. We explain in detail how the PST covariant doubled string arises from an unusual gauge fixing. We pay careful attention to the role of "spectator" fields in this process and also show how the T-duality invariant doubled dilaton emerges naturally. We extend these ideas to non-Abelian T-duality and show they give rise to the duality invariant formalism based on the semi-Abelian Drinfeld Double. We then develop the N = (0, 1) supersymmetric duality invariant formalism.

  1. Hyperthyroid hypokalemic periodic paralysis

    PubMed Central

    Neki, N.S.

    2016-01-01

    Hyperthyroid periodic paralysis (HPP) is a rare life threatening complication of hyperthyroidism commonly occurring in young Asian males but sporadically found in other races. It is characterised by hypokalemia and acute onset paraparesis with prevalence of one in one hundred thousand (1 in 100000). The symptoms resolve promptly with potassium supplementation. Nonselective beta blockers like propranol can also be used to ameliorate and prevent subsequent paralytic attack. We report a case of 22 year old male presenting with hyperthyroid periodic paralysis (HPP) having very low serum potassium level. PMID:27648066

  2. Double-Base Binder Improvement

    DTIC Science & Technology

    The general objective of this program is to improve the mechanical properties of composite modified double base ( CMDB ) propellants, with particular emphasis upon those prepared by the slurry cast process.

  3. Entanglement purification with double selection

    SciTech Connect

    Fujii, Keisuke; Yamamoto, Katsuji

    2009-10-15

    We investigate an entanglement purification protocol with double-selection process, which works under imperfect local operations. Compared with the usual protocol with single selection, this double-selection method has higher noise thresholds for the local operations and quantum communication channels and achieves higher fidelity of purified states. It also provides a yield comparable to that of the usual protocol with single selection. We discuss on general grounds how some of the errors which are introduced by local operations are left as intrinsically undetectable. The undetectable errors place a general upper bound on the purification fidelity. The double selection is a simple method to remove all the detectable errors in the first order, so that the upper bound on the fidelity is achieved in the low-noise regime. The double selection is further applied to purification of multipartite entanglement such as two-colorable graph states.

  4. [The double and his theatre].

    PubMed

    Trillet, M

    1996-01-01

    Professor Paul Girard dedicated an important part of his scientific works to the notion of the Double. He was naturally prompted to such an investigation because of his interest in lateralization disorders and in the problems of cerebral functional asymmetry. We present his conception, in view of recent information of modern neuropsychology as regards identification and recognition processes, as well as anticipation and familiarity operations. Beyond the problem of the Double, the search for Identity is considered in artistic and literary activity.

  5. A Modern Periodic Table.

    ERIC Educational Resources Information Center

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  6. Periodic Table of Students.

    ERIC Educational Resources Information Center

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  7. Periodically poled silicon

    NASA Astrophysics Data System (ADS)

    Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram

    2010-02-01

    Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

  8. Oscillations following periodic reinforcement.

    PubMed

    Monteiro, Tiago; Machado, Armando

    2009-06-01

    Three experiments examined behavior in extinction following periodic reinforcement. During the first phase of Experiment 1, four groups of pigeons were exposed to fixed interval (FI 16s or FI 48s) or variable interval (VI 16s or VI 48s) reinforcement schedules. Next, during the second phase, each session started with reinforcement trials and ended with an extinction segment. Experiment 2 was similar except that the extinction segment was considerably longer. Experiment 3 replaced the FI schedules with a peak procedure, with FI trials interspersed with non-food peak interval (PI) trials that were four times longer. One group of pigeons was exposed to FI 20s PI 80s trials, and another to FI 40s PI 160s trials. Results showed that, during the extinction segment, most pigeons trained with FI schedules, but not with VI schedules, displayed pause-peck oscillations with a period close to, but slightly greater than the FI parameter. These oscillations did not start immediately after the onset of extinction. Comparing the oscillations from Experiments 1 and 2 suggested that the alternation of reconditioning and re-extinction increases the reliability and earlier onset of the oscillations. In Experiment 3 the pigeons exhibited well-defined pause-peck cycles since the onset of extinction. These cycles had periods close to twice the value of the FI and lasted for long intervals of time. We discuss some hypotheses concerning the processes underlying behavioral oscillations following periodic reinforcement.

  9. Astrophysical implications of periodicity

    NASA Technical Reports Server (NTRS)

    Muller, Richard A.

    1988-01-01

    Two remarkable discoveries of the last decade have profound implications for astrophysics and for geophysics. These are the discovery by Alvarez et al., that certain mass extinctions are caused by the impact on the earth of a large asteroid or comet, and the discovery by Raup and Sepkoski that such extinctions are periodic, with a cycle time of 26 to 30 million years. The validity of both of these discoveries is assumed and the implications are examined. Most of the phenomena described depend not on periodicity, but just on the weaker assumption that the impacts on the earth take place primarily in showers. Proposed explanations for the periodicity include galactic oscillations, the Planet X model, and the possibility of Nemesis, a solar companion star. These hypotheses are critically examined. Results of the search for the solar companion are reported. The Deccan flood basalts of India have been proposed as the impact site for the Cretaceous impact, but this hypotheisis is in contradiction with the conclusion of Courtillot et al., that the magma flow began during a period of normal magnetic field. A possible resolution of this contradiction is proposed.

  10. Periodically structured plasmonic waveguides

    NASA Astrophysics Data System (ADS)

    Saj, W. M.; Foteinopoulou, S.; Kafesaki, M.; Soukoulis, C. M.; Economou, E. N.

    2008-04-01

    We study surface plasmon polariton (SPP) guiding structures, which are a modification of the Metal-Insulator-Metal (MIM) waveguide. The designs are constructed by introducing a periodic modulation in a MIM waveguide, with a glass core and silver claddings. This periodic modulation is created either by causing periodic indentations in the silver slabs encompassing the glass core, or by increasing the glass spacer material in certain periodic locations. Our objective is to achieve long range sub-wavelength waveguiding with vast dispersion engineering capabilities. We employ the Finite Difference Time Domain Method (FDTD) with the Auxiliary Differential Equation method (ADE) for the calculation of the dispersion relation of the guided modes, as well as the real time propagation suggests that the guiding mechnism in the examined structures is based on the electromagnetic (EM) couping between the slit plasmon modes. These - depending on the design - exist in the grooves between the silver plates or in the larger areas of the glass core spacer. Put it different, the guiding mechanism in the examined SPP waveguide designs is analogous to the EM energy transfer along metallic nanoparticle chains.

  11. Getting Your Period

    MedlinePlus

    ... for a woman to have a baby. During sexual intercourse, the egg can get fertilized by a male’s sperm and then attach to the lining of the uterus ( endometrium ) and grow into a baby. ( Read more about reproduction. ) Does your period come each month? top Menstrual ...

  12. Optical localization in quasi-periodic multilayers

    NASA Astrophysics Data System (ADS)

    Vasconcelos, M. S.; Albuquerque, E. L.; Mariz, A. M.

    1998-07-01

    We investigate the optical transmission spectra of quasi-periodic dielectric multilayer slabs arranged in a fashion that exhibits what has been called deterministic disorders. They can be of the so-called substitutional sequences type, and are characterized by the nature of their Fourier spectrum, which can be dense pure point (e.g. a Fibonacci sequence) or singular continuous (e.g. Thue-Morse and double-period sequences). The transmission coefficients are conveniently derived by using a theoretical model based on the transfer-matrix approach. A comparison between the oblique-incidence optical transmission spectrum and the normal-incidence one shows quite a different transmission behaviours over a particular range of frequency.

  13. Cells anticipate periodic events

    NASA Astrophysics Data System (ADS)

    Nakagaki, Toshiyuki

    2009-03-01

    We show that an amoeboid organism can anticipate the timing of periodic events. The plasmodium of the true slime mold Physarum polycephalum moves rapidly under favourable conditions, but stops moving when transferred to less-favourable conditions. Plasmodia exposed to unfavourable conditions, presented in three consecutive pulses at constant intervals, reduced their locomotive speed in response to each episode. When subsequently subjected to favourable conditions, the plasmodia spontaneously reduced their locomotive speed at the time point when the next unfavourable episode would have occurred. This implied anticipation of impending environmental change. After this behaviour had been evoked several times, the locomotion of the plasmodia returned to normal; however, the anticipatory response could subsequently be induced by a single unfavourable pulse, implying recall of the memorized periodicity. We explored the mechanisms underlying these behaviours from a dynamical systems perspective. Our results hint at the cellular origins of primitive intelligence and imply that simple dynamics might be sufficient to explain its emergence.

  14. Some dynamical properties of very strong double layers in a triple plasma device

    NASA Technical Reports Server (NTRS)

    Carpenter, T.; Torven, S.

    1987-01-01

    Dynamical properties of very strong double layers seen in a differentially pumped triple plasma device are reported. These double layers are V-shaped. The following findings are discussed: (1) Disruptions in the double layer potential and in the plasma current occur when an inductance is placed in series with the bias supply between the sources in the external circuit. These disruptions, which can be highly periodic, are the result of a negative resistance region. (2) When reactances in the circuit are minimized, the double layer exhibits a jitter motion in position approximately equal to the double layer thickness. (3) When the bias between the sources is rapidly turned on, the initial phase in the double layer formation is the occurrence of a constant electric field for the first few microseconds. First the apparatus used in all of the work is discussed and then each of the three phenomena are considered.

  15. The double loop mattress suture

    PubMed Central

    Biddlestone, John; Samuel, Madan; Creagh, Terry; Ahmad, Tariq

    2014-01-01

    An interrupted stitch type with favorable tissue characteristics will reduce local wound complications. We describe a novel high-strength, low-tension repair for the interrupted closure of skin, cartilage, and muscle, the double loop mattress stitch, and compare it experimentally with other interrupted closure methods. The performance of the double loop mattress technique in porcine cartilage and skeletal muscle is compared with the simple, mattress, and loop mattress interrupted sutures in both a novel porcine loading chamber and mechanical model. Wound apposition is assessed by electron microscopy. The performance of the double loop mattress in vivo was confirmed using a series of 805 pediatric laparotomies/laparoscopies. The double loop mattress suture is 3.5 times stronger than the loop mattress in muscle and 1.6 times stronger in cartilage (p ≤ 0.001). Additionally, the double loop mattress reduces tissue tension by 66% compared with just 53% for the loop mattress (p ≤ 0.001). Wound gapping is equal, and wound eversion appears significantly improved (p ≤ 0.001) compared with the loop mattress in vitro. In vivo, the double loop mattress performs as well as the loop mattress and significantly better than the mattress stitch in assessments of wound eversion and dehiscence. There were no episodes of stitch extrusion in our series of patients. The mechanical advantage of its intrinsic pulley arrangement gives the double loop mattress its favorable properties. Wound dehiscence is reduced because this stitch type is stronger and exerts less tension on the tissue than the mattress stitch. We advocate the use of this novel stitch wherever a high-strength, low-tension repair is required. These properties will enhance wound repair, and its application will be useful to surgeons of all disciplines. PMID:24698436

  16. A Double Dusty Dilemma

    NASA Astrophysics Data System (ADS)

    Farihi, Jay; Gansicke, Boris; Parsons, Steven

    2015-04-01

    We have serendipitously discovered the first metal-polluted white dwarf with what appears to be a circumbinary dust disk. Both the atmospheric metals and infrared excess were found by our team a few years ago, but only recently (and much to our surprise) did we measure a spectroscopic periodicity of 2.27 hr which unambiguously identifies this peculiar system as a close binary. Most remarkable for this DDT proposal is that the system must be (highly) dynamically unstable, as a companion and canonical dust disk occupy overlapping orbital regions. We therefore conclude the system must be in a high state of flux and propose a short, single observation with IRAC to compare with our prior flux measurements obtained in late 2009. Any change will prompt an observing campaign for detailed monitoring. We speculate we are witnessing a destructive event in real time, and if correct, this system may yield an unprecedented view into the long-term evolution of circumbinary planetary systems.

  17. Periodic minimal surfaces

    NASA Astrophysics Data System (ADS)

    Mackay, Alan L.

    1985-04-01

    A minimal surface is one for which, like a soap film with the same pressure on each side, the mean curvature is zero and, thus, is one where the two principal curvatures are equal and opposite at every point. For every closed circuit in the surface, the area is a minimum. Schwarz1 and Neovius2 showed that elements of such surfaces could be put together to give surfaces periodic in three dimensions. These periodic minimal surfaces are geometrical invariants, as are the regular polyhedra, but the former are curved. Minimal surfaces are appropriate for the description of various structures where internal surfaces are prominent and seek to adopt a minimum area or a zero mean curvature subject to their topology; thus they merit more complete numerical characterization. There seem to be at least 18 such surfaces3, with various symmetries and topologies, related to the crystallographic space groups. Recently, glyceryl mono-oleate (GMO) was shown by Longley and McIntosh4 to take the shape of the F-surface. The structure postulated is shown here to be in good agreement with an analysis of the fundamental geometry of periodic minimal surfaces.

  18. Double metric, generalized metric, and α' -deformed double field theory

    NASA Astrophysics Data System (ADS)

    Hohm, Olaf; Zwiebach, Barton

    2016-03-01

    We relate the unconstrained "double metric" of the "α' -geometry" formulation of double field theory to the constrained generalized metric encoding the spacetime metric and b -field. This is achieved by integrating out auxiliary field components of the double metric in an iterative procedure that induces an infinite number of higher-derivative corrections. As an application, we prove that, to first order in α' and to all orders in fields, the deformed gauge transformations are Green-Schwarz-deformed diffeomorphisms. We also prove that to first order in α' the spacetime action encodes precisely the Green-Schwarz deformation with Chern-Simons forms based on the torsionless gravitational connection. This seems to be in tension with suggestions in the literature that T-duality requires a torsionful connection, but we explain that these assertions are ambiguous since actions that use different connections are related by field redefinitions.

  19. Ixekizumab, an interleukin-17A specific monoclonal antibody, for the treatment of biologic-naive patients with active psoriatic arthritis: results from the 24-week randomised, double-blind, placebo-controlled and active (adalimumab)-controlled period of the phase III trial SPIRIT-P1

    PubMed Central

    Mease, Philip J; Ritchlin, Christopher T; Okada, Masato; Cuchacovich, Raquel S; Shuler, Catherine L; Lin, Chen-Yen; Braun, Daniel K; Lee, Chin H; Gladman, Dafna D

    2017-01-01

    Objective To assess the safety and efficacy of ixekizumab, a monoclonal antibody that inhibits interleukin-17A, in a double-blind phase III trial enrolling patients with active psoriatic arthritis (PsA). Methods Patients naive to biologic therapy with active PsA were randomised to subcutaneous injections of placebo (N=106), adalimumab 40 mg once every 2 weeks (active reference; N=101), ixekizumab 80 mg once every 2 weeks (IXEQ2W) (N=103), or ixekizumab 80 mg once every 4 weeks (IXEQ4W) (N=107). Both ixekizumab regimens included a 160-mg starting dose. The primary objective was to assess the superiority of IXEQ2W or IXEQ4W versus placebo as measured by the proportion of patients achieving an American College of Rheumatology 20 (ACR20) response at week 24. Results Significantly more patients treated with ixekizumab achieved an ACR20 response with IXEQ2W (62.1%) or IXEQ4W (57.9%) than placebo (30.2%) (p≤0.001; non-responder imputation method). Disease activity and functional disability were significantly improved with both ixekizumab doses versus placebo at weeks 12 and 24, and there was significantly less progression of structural damage at week 24 (p≤0.01). Clearance of plaque psoriasis was greater with ixekizumab than placebo (p≤0.001). Efficacy results with adalimumab, the active reference arm, showed significant improvements versus placebo. Treatment-emergent adverse events were more frequent with ixekizumab (65.7–66.4%) and adalimumab (64.4%) than placebo (47.2%) (p<0.05). Conclusions In biologic-naive patients with active PsA, ixekizumab treatment resulted in improvements in disease activity and physical function, as well as in the inhibition of structural damage progression. Overall, adverse events were more frequent in all active groups compared with placebo. Trial registration number NCT01695239; EudraCT2011-002326-49; Results. PMID:27553214

  20. Spatial phase-shifting characteristic of double grating interferometer.

    PubMed

    Song, Yang; Chen, Yunyun; He, Anzhi; Zhao, Zhimin

    2009-10-26

    Double grating interferometer is usually used to achieve phase information from distorted wave front by its temporal phase-shifting characteristic. In this paper, the spatial phase-shifting characteristic of double grating interferometer is presented. The explicit intensity distributions of interferograms produced by double gratings are derived with the scalar diffraction theory, and the stable phase shift is found between plus-first, zero and minus-first order interferograms. Results indicate that the phase shift only depends on the grating period and the distance between two gratings if no phase object exists. If phase object exists, it varies on the interferograms. But the phase shifts are equal at any special point of interferograms. In particular, the triple grating interferometer is presented to generate at least four phase shift interferograms simultaneously with the similar method.

  1. Conformation dependent electronic transport in a DNA double-helix

    SciTech Connect

    Kundu, Sourav Karmakar, S. N.

    2015-10-15

    We present a tight-binding study of conformation dependent electronic transport properties of DNA double-helix including its helical symmetry. We have studied the changes in the localization properties of DNA as we alter the number of stacked bases within every pitch of the double-helix keeping fixed the total number of nitrogen bases within the DNA molecule. We take three DNA sequences, two of them are periodic and one is random and observe that in all the cases localization length increases as we increase the radius of DNA double-helix i.e., number of nucleobases within a pitch. We have also investigated the effect of backbone energetic on the I-V response of the system and found that in presence of helical symmetry, depending on the interplay of conformal variation and disorder, DNA can be found in either metallic, semiconducting and insulating phases, as observed experimentally.

  2. The effect of multiple encounters on short period comet orbits

    NASA Technical Reports Server (NTRS)

    Lowrey, B. E.

    1972-01-01

    The observed orbital elements of short period comets are found to be consistent with the hypothesis of derivation from long period comets as long as two assumptions are made. First, the distribution of short period comets has been randomized by multiple encounters with Jupiter and second, the short period comets have lower velocities of encounter with Jupiter than is generally expected. Some 16% of the observed short period comets have lower encounter velocities than is allowed mathematically using Laplace's method. This may be due to double encounter processes with Jupiter and Saturn, or as a result of prolonged encounters. The distribution of unobservable short period comets can be inferred in part from the observed comets. Many have orbits between Jupiter and Saturn with somewhat higher inclinations than those with perihelions near the earth. Debris from those comets may form the major component of the zodiacal dust.

  3. Double shrinking sparse dimension reduction.

    PubMed

    Zhou, Tianyi; Tao, Dacheng

    2013-01-01

    Learning tasks such as classification and clustering usually perform better and cost less (time and space) on compressed representations than on the original data. Previous works mainly compress data via dimension reduction. In this paper, we propose "double shrinking" to compress image data on both dimensionality and cardinality via building either sparse low-dimensional representations or a sparse projection matrix for dimension reduction. We formulate a double shrinking model (DSM) as an l(1) regularized variance maximization with constraint ||x||(2)=1, and develop a double shrinking algorithm (DSA) to optimize DSM. DSA is a path-following algorithm that can build the whole solution path of locally optimal solutions of different sparse levels. Each solution on the path is a "warm start" for searching the next sparser one. In each iteration of DSA, the direction, the step size, and the Lagrangian multiplier are deduced from the Karush-Kuhn-Tucker conditions. The magnitudes of trivial variables are shrunk and the importances of critical variables are simultaneously augmented along the selected direction with the determined step length. Double shrinking can be applied to manifold learning and feature selections for better interpretation of features, and can be combined with classification and clustering to boost their performance. The experimental results suggest that double shrinking produces efficient and effective data compression.

  4. Radio emissions from double RHESSI TGFs

    NASA Astrophysics Data System (ADS)

    Mezentsev, Andrew; Østgaard, Nikolai; Gjesteland, Thomas; Albrechtsen, Kjetil; Lehtinen, Nikolai; Marisaldi, Martino; Smith, David; Cummer, Steven

    2016-07-01

    A detailed analysis of Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) terrestrial gamma ray flashes (TGFs) is performed in association with World Wide Lightning Location Network (WWLLN) sources and very low frequency (VLF) sferics recorded at Duke University. RHESSI clock offset is evaluated and found to experience changes on the 5 August 2005 and 21 October 2013, based on the analysis of TGF-WWLLN matches. The clock offsets were found for all three periods of observations with standard deviations less than 100 μs. This result opens the possibility for the precise comparative analyses of RHESSI TGFs with the other types of data (WWLLN, radio measurements, etc.) In case of multiple-peak TGFs, WWLLN detections are observed to be simultaneous with the last TGF peak for all 16 cases of multipeak RHESSI TGFs simultaneous with WWLLN sources. VLF magnetic field sferics were recorded for two of these 16 events at Duke University. These radio measurements also attribute VLF sferics to the second peak of the double TGFs, exhibiting no detectable radio emission during the first TGF peak. Possible scenarios explaining these observations are proposed. Double (multipeak) TGFs could help to distinguish between the VLF radio emission radiated by the recoil currents in the +IC leader channel and the VLF emission from the TGF producing electrons.

  5. Aboveground storage tank double bottom cathodic protection

    SciTech Connect

    Surkein, M.B.

    1995-12-31

    Cathodic protection is typically used to achieve corrosion control between bottoms of aboveground storage tanks with double bottoms. To determine the proper design of such systems, an investigation was conducted on the performance of two different cathodic protection system designs utilizing zinc ribbon anodes. A full scale field test on a 35 meter (115 feet) diameter tank was conducted to determine cathodic protection system performance. The test included periodic measurement of tank bottom steel potentials including on, instant off and polarization decay, anode current output and tank product level measurements.Results showed that zinc ribbon anode spacing in a chord fashion of 1.2 meter (4 feet) or less can be effective to achieve cathodic protection according to industry accepted standards. Utilizing the design information gained by the study, a standard sacrificial anode and impressed current anode cathodic protection system has been developed.

  6. The postanesthetic period. Complications.

    PubMed

    Malamed, S F

    1987-01-01

    Postanesthetic complications can occur even in the best of circumstances. Proper preparation of the staff, aggressive monitoring of the recovering patient, and early recognition and management of the complications are essential if the outcome is to be successful. In reviewing postanesthetic complications, two factors are present in the overwhelming majority of situations--hypoxia and hypercarbia--often the direct result of inadequate monitoring during the postanesthetic period. The anesthetic procedure is not over once the anesthetic agents are discontinued. The skillful anesthetist is aware of the possibilities of postoperative complications and prevents problems by employing enhanced monitoring techniques during the recovery phase.

  7. Controls on geyser periodicity.

    PubMed

    Ingebritsen, S E; Rojstaczer, S A

    1993-11-05

    Geyser eruption frequency is not constant over time and has been shown to vary with small (periodicity. Much of the responsiveness to remote seismicity and other small strains in the Earth can be explained in terms of variations in permeability and lateral recharge rates.

  8. Controls on geyser periodicity

    USGS Publications Warehouse

    Ingebritsen, S.E.; Rojstaczer, S.A.

    1993-01-01

    Geyser eruption frequency is not constant over time and has been shown to vary with small (???10-6) strains induced by seismic events, atmospheric loading, and Earth tides. The geyser system is approximated as a permeable conduit of intensely fractured rock surrounded by a less permeable rock matrix. Numerical simulation of this conceptual model yields a set of parameters that controls geyser existence and periodicity. Much of the responsiveness to remote seismicity and other small strains in the Earth can be explained in terms of variations in permeability and lateral recharge rates.

  9. New double soft emission theorems

    NASA Astrophysics Data System (ADS)

    Cachazo, Freddy; He, Song; Yuan, Ellis Ye

    2015-09-01

    We study the behavior of the tree-level S-matrix of a variety of theories as two particles become soft. By analogy with the recently found subleading soft theorems for gravitons and gluons, we explore subleading terms in double soft emissions. We first consider double soft scalar emissions and find subleading terms that are controlled by the angular momentum operator acting on hard particles. The order of the subleading theorems depends on the presence or not of color structures. Next we obtain a compact formula for the leading term in a double soft photon emission. The theories studied are a special Galileon, Dirac-Born-Infeld, Einstein-Maxwell-Scalar, nonlinear sigma model and Yang-Mills-Scalar. We use the recently found Cachazo-He-Yuan representation of these theories in order to give a simple proof of the leading order part of all these theorems.

  10. Double field theory inspired cosmology

    SciTech Connect

    Wu, Houwen; Yang, Haitang E-mail: hyanga@scu.edu.cn

    2014-07-01

    Double field theory proposes a generalized spacetime action possessing manifest T-duality on the level of component fields. We calculate the cosmological solutions of double field theory with vanishing Kalb-Ramond field. It turns out that double field theory provides a more consistent way to construct cosmological solutions than the standard string cosmology. We construct solutions for vanishing and non-vanishing symmetry preserving dilaton potentials. The solutions assemble the pre- and post-big bang evolutions in one single line element. Our results show a smooth evolution from an anisotropic early stage to an isotropic phase without any special initial conditions in contrast to previous models. In addition, we demonstrate that the contraction of the dual space automatically leads to both an inflation phase and a decelerated expansion of the ordinary space during different evolution stages.

  11. Double emulsion formation through hierarchical flow-focusing microchannel

    NASA Astrophysics Data System (ADS)

    Azarmanesh, Milad; Farhadi, Mousa; Azizian, Pooya

    2016-03-01

    A microfluidic device is presented for creating double emulsions, controlling their sizes and also manipulating encapsulation processes. As a result of three immiscible liquids' interaction using dripping instability, double emulsions can be produced elegantly. Effects of dimensionless numbers are investigated which are Weber number of the inner phase (Wein), Capillary number of the inner droplet (Cain), and Capillary number of the outer droplet (Caout). They affect the formation process, inner and outer droplet size, and separation frequency. Direct numerical simulation of governing equations was done using volume of fluid method and adaptive mesh refinement technique. Two kinds of double emulsion formation, the two-step and the one-step, were simulated in which the thickness of the sheath of double emulsions can be adjusted. Altering each dimensionless number will change detachment location, outer droplet size and droplet formation period. Moreover, the decussate regime of the double-emulsion/empty-droplet is observed in low Wein. This phenomenon can be obtained by adjusting the Wein in which the maximum size of the sheath is discovered. Also, the results show that Cain has significant influence on the outer droplet size in the two-step process, while Caout affects the sheath in the one-step formation considerably.

  12. Multifunctional periodic cellular metals.

    PubMed

    Wadley, Haydn N G

    2006-01-15

    Periodic cellular metals with honeycomb and corrugated topologies are widely used for the cores of light weight sandwich panel structures. Honeycombs have closed cell pores and are well suited for thermal protection while also providing efficient load support. Corrugated core structures provide less efficient and highly anisotropic load support, but enable cross flow heat exchange opportunities because their pores are continuous in one direction. Recent advances in topology design and fabrication have led to the emergence of lattice truss structures with open cell structures. These three classes of periodic cellular metals can now be fabricated from a wide variety of structural alloys. Many topologies are found to provide adequate stiffness and strength for structural load support when configured as the cores of sandwich panels. Sandwich panels with core relative densities of 2-10% and cell sizes in the millimetre range are being assessed for use as multifunctional structures. The open, three-dimensional interconnected pore networks of lattice truss topologies provide opportunities for simultaneously supporting high stresses while also enabling cross flow heat exchange. These highly compressible structures also provide opportunities for the mitigation of high intensity dynamic loads created by impacts and shock waves in air or water. By filling the voids with polymers and hard ceramics, these structures have also been found to offer significant resistance to penetration by projectiles.

  13. Periodic truss structures

    NASA Astrophysics Data System (ADS)

    Zok, Frank W.; Latture, Ryan M.; Begley, Matthew R.

    2016-11-01

    Despite the recognition of the enormous potential of periodic trusses for use in a broad range of technologies, there are no widely-accepted descriptors of their structure. The terminology has been based loosely either on geometry of polyhedra or of point lattices: neither of which, on its own, has an appropriate structure to fully define periodic trusses. The present article lays out a system for classification of truss structure types. The system employs concepts from crystallography and geometry to describe nodal locations and connectivity of struts. Through a series of illustrative examples of progressively increasing complexity, a rational taxonomy of truss structure is developed. Its conceptual evolution begins with elementary cubic trusses, increasing in complexity with non-cubic and compound trusses as well as supertrusses, and, finally, with complex trusses. The conventions and terminology adopted to define truss structure yield concise yet unambiguous descriptions of structure types and of specific (finite) trusses. The utility of the taxonomy is demonstrated by bringing into alignment a disparate set of ad hoc and incomplete truss designations previously employed in a broad range of science and engineering fields. Additionally, the merits of a particular compound truss (comprising two interpenetrating elementary trusses) is shown to be superior to the octet truss for applications requiring high stiffness and elastic isotropy. By systematically stepping through and analyzing the finite number of structure types identified through the present classification system, optimal structures for prescribed mechanical and functional requirements are expected to be ascertained in an expeditious manner.

  14. Double stranded nucleic acid biochips

    DOEpatents

    Chernov, Boris; Golova, Julia

    2006-05-23

    This invention describes a new method of constructing double-stranded DNA (dsDNA) microarrays based on the use of pre-synthesized or natural DNA duplexes without a stem-loop structure. The complementary oligonucleotide chains are bonded together by a novel connector that includes a linker for immobilization on a matrix. A non-enzymatic method for synthesizing double-stranded nucleic acids with this novel connector enables the construction of inexpensive and robust dsDNA/dsRNA microarrays. DNA-DNA and DNA-protein interactions are investigated using the microarrays.

  15. Double-negative acoustic metamaterial.

    PubMed

    Li, Jensen; Chan, C T

    2004-11-01

    We show here the existence of acoustic metamaterial, in which both the effective density and bulk modulus are simultaneously negative, in the true and strict sense of an effective medium. Our double-negative acoustic system is an acoustic analogue of Veselago's medium in electromagnetism, and shares many unique consequences, such as negative refractive index. The double negativity in acoustics is derived from low-frequency resonances, as in the case of electromagnetism, but the negative density and modulus are derived from a single resonance structure as distinct from electromagnetism in which the negative permeability and negative permittivity originates from different resonance mechanisms.

  16. Current driven weak double layers

    NASA Technical Reports Server (NTRS)

    Chanteur, Gerard

    1987-01-01

    Double layers in plasmas can be created by different means. For example, a potential difference forms between two plasmas with different temperatures, in a plasma jet flowing along a converging magnetic field, in a quiescent plasma submitted to an external difference of potential, or in a turbulent plasma carrying an electric charge. The first three cases can be current-free, but not necessarily, although the numerical simulations were made under such conditions for the first two points. Apart from the third case, which is mainly of interest for laboratory experiments, these double layers are good candidates for accelerating the auroral electrons to the few kiloelectron volts observed.

  17. Double-branched vortex generator

    NASA Technical Reports Server (NTRS)

    Cantwell, E. R.; Westphal, R. V.; Mehta, R. D.

    1985-01-01

    In order to assess the suitability of using a double branched vortex generator in parametric studies involving vortex interactions, an experimental study of the main vortex and secondary flows produced by a double branched vortex generator was conducted in a 20-by-40 cm indraft wind tunnel. Measurements of the cross flow velocities were made with a five hole pressure probe from which vorticity contours and vortex parameters were derived. The results showed that the optimum configuration consisted of chord extensions with the absence of a centerbody.

  18. Analysis of Somatropin by Double-Injection Capillary-Zone Electrophoresis in Polybrene/Chondroitin Sulfate A Double-Coated Capillaries.

    PubMed

    Amini, Ahmad

    2016-01-01

    Purity determination of somatropin as a recombinant protein is important to ensure its safety and quality. This is carried out by capillary zone electrophoresis in double-injection mode using polybrene/chondroitin sulfate A double-coated capillaries. Modification of the capillary wall eliminates protein-wall interactions which results in improved accuracy and precision of the determinations. In the double-injection mode two somatropin samples are analyzed within a single electrophoretic run. Prior to the second injection, the first injected plug is electrophoresed for a predetermined time period in order to adjust the inter-plug distance. Here, the principle for the separation of somatropin charge variants is described.

  19. The luminosity of the double-mode Cepheid Y Carinae

    NASA Technical Reports Server (NTRS)

    Evans, Nancy R.

    1992-01-01

    IUE spectra of the double-mode Cepheid Y Carinae have been used to determine the spectral type of the binary companion. From the companion spectral type (B9.O V), the absolute magnitude of the Cepheid is found to be -2.94 mag, with an estimated uncertainty of +/-0.3. This luminosity is in good agreement with that from the period-luminosity-color relation of Feast and Walker for the fundamental mode. This agreement, together with the large magnitude difference between the B9.0 V star and the Cepheid, confirm that the Cepheid is a normal classical Cepheid with a mass much larger than that inferred from the ratio of the two periods (beat mass). The two double-mode Cepheids with independently determined luminosities (Y Car and V 367 Sct) both fall on the blue edge of the instability strip.

  20. A double magnetic solar cycle and dynamical systems

    NASA Astrophysics Data System (ADS)

    Popova, H.

    Various solar activity data have indicated that along with the well-known 22-year cycle there is a shorter periodicity of about 2 years. To simulate this phenomenon, we constructed a dynamical system, which reproduced double-periodic behaviour of the solar cycle. Such nonlinear dynamical system described the solar αω-dynamo process with variable intensities Rα and Rω of the α-effect and the differential rotation, respectively. We have plotted the time distribution and butterfly diagrams for the poloidal and toroidal magnetic fields with dipole and quadrupole symmetries. The dynamical system with dipole symmetry of the magnetic field reproduces a regime similar to the double cycle at -450 < RαRω < -210. In the case of quadrupole symmetry, this regime exists at -220 < RαRω < -190.

  1. Model Valid Prediction Period

    NASA Astrophysics Data System (ADS)

    Chu, P. C.

    2002-12-01

    A new concept, valid prediction period (VPP), is presented here to evaluate model predictability. VPP is defined as the time period when the prediction error first exceeds a pre-determined criterion (i.e., the tolerance level). It depends not only on the instantaneous error growth, but also on the noise level, the initial error, and tolerance level. The model predictability skill is then represented by a single scalar, VPP. The longer the VPP, the higher the model predictability skill is. A theoretical framework on the base of the backward Fokker-Planck equation is developed to determine the probability density function (pdf) of VPP. Verification of a Gulf of Mexico nowcast/forecast model is used as an example to demonstrate the usefulness of VPP. Power law scaling is found in the mean square error of displacement between drifting buoy and model trajectories (both at 50 m depth). The pdf of VPP is asymmetric with a long and broad tail on the higher value side, which suggests long-term predictability. The calculations demonstrate that the long-term (extreme long such as 50-60 day) predictability is not an "outlier" and shares the same statistical properties as the short-term predictions. References Chu P. C., L. M. Ivanov, and C.W. Fan, Backward Fokker-Plank equation for determining model predictability with unknown initial error distribution. J. Geophys. Res., in press, 2002. Chu P.C., L.M.Ivanov, T.M. Margolina, and O.V.Melnichenko, 2002b: On probabilistic stability of an atmospheric model to various amplitude perturbations. J. Atmos. Sci., in press Chu P.C., L.M. Ivanov, L. Kantha, O.V. Melnichenko and Y.A. Poberezhny, 2002c: The long-term correlations and power decay law in model prediction skill. Geophys. Res. Let., in press.

  2. Quantized charge pumping through a carbon nanotube double quantum dot

    NASA Astrophysics Data System (ADS)

    Chorley, S. J.; Frake, J.; Smith, C. G.; Jones, G. A. C.; Buitelaar, M. R.

    2012-04-01

    We demonstrate single-electron pumping in a gate-defined carbon nanotube double quantum dot. By periodic modulation of the potentials of the two quantum dots, we move the system around charge triple points and transport exactly one electron or hole per cycle. We investigate the pumping as a function of the modulation frequency and amplitude and observe good current quantization up to frequencies of 18 MHz where rectification effects cause the mechanism to break down.

  3. The double well mass filter

    DOE PAGES

    Gueroult, Renaud; Rax, Jean -Marcel; Fisch, Nathaniel J.

    2014-02-03

    Various mass filter concepts based on rotating plasmas have been suggested with the specific purpose of nuclear waste remediation. We report on a new rotating mass filter combining radial separation with axial extraction. Lastly, the radial separation of the masses is the result of a “double-well” in effective radial potential in rotating plasma with a sheared rotation profile.

  4. A Double-Minded Fractal

    ERIC Educational Resources Information Center

    Simoson, Andrew J.

    2009-01-01

    This article presents a fun activity of generating a double-minded fractal image for a linear algebra class once the idea of rotation and scaling matrices are introduced. In particular the fractal flip-flops between two words, depending on the level at which the image is viewed. (Contains 5 figures.)

  5. Natural products: DNA double whammy

    NASA Astrophysics Data System (ADS)

    Gates, Kent S.

    2014-06-01

    The lomaiviticins are exceedingly potent antibiotic agents, but the mechanism responsible for this activity has so far been unclear. Now, efficient generation of double-strand breaks in DNA by lomaiviticin A has been linked to the remarkable cytotoxicity of these diazobenzofluorene-containg natural products.

  6. Double spaces with isolated singularities

    SciTech Connect

    Cheltsov, I A

    2008-02-28

    The non-rationality is proved for double covers of P{sup n} branched over a hypersurface F subset of P{sup n} of degree 2n>=8 with isolated singularities such that the multiplicity of each singular point of F does not exceed 2(n-2) and the projectivization of its tangent cone is smooth. Bibliography: 15 titles.

  7. Keepers of the double stars

    NASA Astrophysics Data System (ADS)

    Tenn, Joseph S.

    2013-03-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Early catalogues by the Herschels, Struves, and others began with their own discoveries. In 1906 court reporter and amateur astronomer Sherburne Wesley Burnham published a massive double star catalogue containing data from many observers on more than 13,000 systems. Lick Observatory astronomer Robert Grant Aitken produced a much larger catalogue in 1932 and coordinated with Robert Innes of Johannesburg, who catalogued the southern systems. Aitken maintained and expanded Burnham's records of observations on handwritten file cards, and eventually turned them over to the Lick Observatory, where astrometrist Hamilton Jeffers further expanded the collection and put all the observations on punched cards. With the aid of Frances M. "Rete" Greeby he made two catalogues: an Index Catalogue with basic data about each star, and a complete catalogue of observations, with one observation per punched card. He enlisted Willem van den Bos of Johannesburg to add southern stars, and together they published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers approached retirement he became greatly concerned about the disposition of the catalogues. He wanted to be replaced by another "double star man," but Lick Director Albert E. Whitford had the new 120-inch reflector, the world's second largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers was vociferously opposed to turning over the card files to another institution, and especially against their coming under the control of Kaj Strand of the United States Naval Observatory. In the end the USNO got the files and has maintained the records ever since, first under Charles Worley, and, since 1997, under Brian Mason. Now called the Washington Double Star Catalog (WDS), it is completely online and currently contains more than 1,200,000 measures of more than 125

  8. A laboratory investigation of potential double layers

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1987-01-01

    In a triple plasma device, the injection of electron current from the source chamber to the target chamber causes the formation of a potential double layer. At a low current density, the space charge of the injected current produces a virtual cathode-type potential double layer. This double layer is stable, and various wave instabilities are observed to associate with this double layer. As the current density is increased, the double layer becomes unstable, and a moving double layer results. As the current density is increased further, the enhanced ionization causes the neutralization of the space charge of the electron beam, and the beam plasma discharge is ignited.

  9. A laboratory investigation of potential double layers

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1987-01-01

    In a triple plasma device, the injection of electron current from the source chamber to the target chamber causes the formation of a potential double layer. At a low current density, the space charge of the injected current produces a virtual cathode-type potential double layer. This double layer is stable and various wave instabilities are observed to associate with this double layer. As the current density is increased, the double layer becomes unstable and a moving double layer results. As the current density is increased further, the enhanced ionization causes the neutralization of the space charge of the electron beam and the 'beam plasma discharge' is ignited.

  10. [Childhood periodic syndromes].

    PubMed

    Cuvellier, J-C; Lépine, A

    2010-01-01

    This review focuses on the so-called "periodic syndromes of childhood that are precursors to migraine", as included in the Second Edition of the International Classification of Headache Disorders. Three periodic syndromes of childhood are included in the Second Edition of the International Classification of Headache Disorders: abdominal migraine, cyclic vomiting syndrome and benign paroxysmal vertigo, and a fourth, benign paroxysmal torticollis is presented in the Appendix. The key clinical features of this group of disorders are the episodic pattern and intervals of complete health. Episodes of benign paroxysmal torticollis begin between 2 and 8 months of age. Attacks are characterized by an abnormal inclination and/or rotation of the head to one side, due to cervical dystonia. They usually resolve by 5 years. Benign paroxysmal vertigo presents as sudden attacks of vertigo, accompanied by inability to stand without support, and lasting seconds to minutes. Age at onset is between 2 and 4 years, and the symptoms disappear by the age of 5. Cyclic vomiting syndrome is characterized in young infants and children by repeated stereotyped episodes of pernicious vomiting, at times to the point of dehydration, and impacting quality of life. Mean age of onset is 5 years. Abdominal migraine remains a controversial issue and presents in childhood with repeated stereotyped episodes of unexplained abdominal pain, nausea and vomiting occurring in the absence of headache. Mean age of onset is 7 years. Both cyclic vomiting syndrome and abdominal migraine are noted for the absence of pathognomonic clinical features but also for the large number of other conditions to be considered in their differential diagnoses. Diagnostic criteria, such as those of the Second Edition of the International Classification of Headache Disorders and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, have made diagnostic approach and management easier. Their diagnosis

  11. Double Photoionization into Double Core-Hole States in Xe

    SciTech Connect

    Hikosaka, Y.; Kaneyasu, T.; Shigemasa, E.; Lablanquie, P.; Penent, F.; Eland, J. H. D.; Aoto, T.; Ito, K.

    2007-05-04

    Double photoionization (DPI) leading to double core-hole states of Xe{sup 2+} 4d{sup -2} has been studied using a magnetic bottle time-of-flight spectrometer. The assignments of the Xe{sup 2+} 4d{sup -2} states are confirmed by the Auger lines extracted from fourfold coincidences including two photoelectrons and two Auger electrons. It is estimated that the core-core DPI into Xe{sup 2+} 4d{sup -2} at a photon energy of 301.6 eV has a favored cross section of about 0.3 MB. The intense core-core DPI is due to mixing of the 4d{sup -2} continuum with the 4p single photoionization, which is manifested in the relative intensities of the Xe{sup 2+} 4d{sup -2} components.

  12. Pathways to doubled haploidy: chromosome doubling during androgenesis.

    PubMed

    Seguí-Simarro, J M; Nuez, F

    2008-01-01

    Production of doubled haploid (DH) plants through androgenesis induction is a promising and convenient alternative to conventional selfing techniques for the generation of pure lines for breeding programs. This process comprises two main steps: induction of androgenesis and duplication of the haploid genome. Such duplication is sometimes indirectly induced by the treatments used to promote androgenic development. But usually, an additional step of direct chromosome doubling must be included in the protocol. Duplication of the haploid genome of androgenic individuals has been thought to occur through three mechanisms: endoreduplication, nuclear fusion and c-mitosis. In this review we will revise and analyze the evidences supporting each of the proposed mechanisms and their relevance during androgenesis induction, embryo/callus development and plant regeneration. Special attention will be devoted to nuclear fusion, whose evidences are accumulating in the last years.

  13. Double Standard/Double Bind: The Sexual Double Standard and Women's Communication about Sex.

    ERIC Educational Resources Information Center

    Muehlenhard, Charlene L.; McCoy, Marcia L.

    1991-01-01

    College women (n=403) attending the University of Kansas (Lawrence) commented on situations of refusal of desire for sexual relations when they actually did want them (scripted refusal). Consistent with theories of proximal determinants of gender-related behavior, scripted refusal provides a way of dealing with the sexual double standard. (SLD)

  14. Studies of Long Period Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Ratajczak, M.; Hełminiak, K. G.; Konacki, M.

    2015-07-01

    The survey of long period eclipsing binaries from the All Sky Automated Survey (ASAS) catalog aims at searching for and characterizing subgiants and red giants in double-lined detached binary systems. Absolute physical and orbital parameters are presented based on radial velocities from high-quality optical spectra obtained with the following telescope/instrument combinations: 8.2 m Subaru/HDS, ESO 3.6 m/HARPS, 1.9 m Radcliffe/GIRAFFE, CTIO 1.5 m/CHIRON, and 1.2 m Euler/CORALIE. Photometric data from ASAS, SuperWASP, and the Solaris Project were also used. We discuss the derived uncertainties for the individual masses and radii of the components (better than 3% for several systems), as well as results from the spectral analysis performed for components of systems whose spectra we disentangled.

  15. Hierarchy in a double braneworld

    SciTech Connect

    Guerrero, Rommel; Rodriguez, R. Omar; Melfo, Alejandra; Pantoja, Nelson

    2006-10-15

    We show that the hierarchy between the Planck and the weak scales can follow from the tendency of gravitons and fermions to localize at different edges of a thick double wall embedded in an AdS{sub 5} spacetime without reflection symmetry. This double wall is a stable BPS thick-wall solution with two subwalls located at its edges; fermions are coupled to the scalar field through Yukawa interactions, but the lack of reflection symmetry forces them to be localized in one of the subwalls. We show that the graviton zero-mode wave function is suppressed in the fermion edge by an exponential function of the distance between the subwalls, and that the massive modes decouple so that Newtonian gravity is recuperated.

  16. Edwards syndrome with double trisomy.

    PubMed

    Tennakoon, J; Kandasamy, Y; Alcock, G; Koh, T H

    2008-07-01

    Double trisomy is rare and the only case reported in the literature died soon after birth. We present another case of double trisomy (48XYY, +18) in a male neonate, who was born to a 28-year-old gravida three parity one mother at 35 weeks of gestation. The baby had features of trisomy 18. Karyotype of the patient showed 48, XYY, +18, Ish (DYZ3*2), (D18Z1*3), nuc ish (DYZ3*2), (D18Z1*3) . The patient had clinical features of trisomy 18. There was no family history of diabetes mellitus and no exposure to chemicals. It has been suggested that the rarity of Y-chromosome involvement in trisomy 18 may be due to discrepancy between the sexes.

  17. Minimal Doubling and Point Splitting

    SciTech Connect

    Creutz, M.

    2010-06-14

    Minimally-doubled chiral fermions have the unusual property of a single local field creating two fermionic species. Spreading the field over hypercubes allows construction of combinations that isolate specific modes. Combining these fields into bilinears produces meson fields of specific quantum numbers. Minimally-doubled fermion actions present the possibility of fast simulations while maintaining one exact chiral symmetry. They do, however, introduce some peculiar aspects. An explicit breaking of hyper-cubic symmetry allows additional counter-terms to appear in the renormalization. While a single field creates two different species, spreading this field over nearby sites allows isolation of specific states and the construction of physical meson operators. Finally, lattice artifacts break isospin and give two of the three pseudoscalar mesons an additional contribution to their mass. Depending on the sign of this mass splitting, one can either have a traditional Goldstone pseudoscalar meson or a parity breaking Aoki-like phase.

  18. Current double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Giuliani, A.

    2005-01-01

    After an introduction about double beta decay and the deep connections between the lepton-violating channel and the neutrino properties, the most sensitive experimental approaches to the search for this rare nuclear transition are described. An overview of the experiments presently running is then given, with particular emphasis on the adopted techniques and their possible extrapolation to next-generation, higher-sensitivity experiments. The present situation about the experimental determination of the Majorana neutrino mass is presented and discussed.

  19. Pair extended coupled cluster doubles

    SciTech Connect

    Henderson, Thomas M.; Scuseria, Gustavo E.; Bulik, Ireneusz W.

    2015-06-07

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreover, pECCD yields sensible albeit inexact results even for attractive interactions where pCCD breaks down.

  20. Latest results from Double Chooz

    NASA Astrophysics Data System (ADS)

    Minotti, A.

    2017-01-01

    Double Chooz is a short-baseline neutrino disappearance experiment. It detects ν¯ e produced in the power plant of Chooz, France, where is located. The main goal of the experiment is the measurement of θ13 mixing angle and in 2011 for the first time the experiment observed an indication for a non zero value of such an oscillation parameter. The mixing angle was successively measured using only the far detector finding the best fit value of sin2(2θ13) = 0.090 -0.029 +0.032 . The near detector is under construction and will start data taking by the middle of 2014 allowing the reduction of the systematic errors. In this paper I make a review of the Double Chooz experiment, focusing in particular on the latest results of the measurement of the mixing angle θ13 relying on the neutron absorption on Gadolinium. I also present results proving the capability of Double Chooz to identify the ortho-positronium. This has been done in an event-by-event basis for the first time in a large liquid scintillator experiments, and can be an additional handle for the electron/positron discrimination in future detectors based on such technology.

  1. Revisiting double Dirac delta potential

    NASA Astrophysics Data System (ADS)

    Ahmed, Zafar; Kumar, Sachin; Sharma, Mayank; Sharma, Vibhu

    2016-07-01

    We study a general double Dirac delta potential to show that this is the simplest yet still versatile solvable potential to introduce double wells, avoided crossings, resonances and perfect transmission (T = 1). Perfect transmission energies turn out to be the critical property of symmetric and anti-symmetric cases wherein these discrete energies are found to correspond to the eigenvalues of a Dirac delta potential placed symmetrically between two rigid walls. For well(s) or barrier(s), perfect transmission (or zero reflectivity, R(E)) at energy E=0 is non-intuitive. However, this has been found earlier and called the ‘threshold anomaly’. Here we show that it is a critical phenomenon and we can have 0≤slant R(0)\\lt 1 when the parameters of the double delta potential satisfy an interesting condition. We also invoke a zero-energy and zero curvature eigenstate (\\psi (x)={Ax}+B) of the delta well between two symmetric rigid walls for R(0)=0. We resolve that the resonant energies and the perfect transmission energies are different and they arise differently.

  2. Double-Plate Penetration Equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    2000-01-01

    This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

  3. Double excitations in finite systems.

    PubMed

    Romaniello, P; Sangalli, D; Berger, J A; Sottile, F; Molinari, L G; Reining, L; Onida, G

    2009-01-28

    Time-dependent density-functional theory (TDDFT) is widely used in the study of linear response properties of finite systems. However, there are difficulties in properly describing excited states, which have double- and higher-excitation characters, which are particularly important in molecules with an open-shell ground state. These states would be described if the exact TDDFT kernel were used; however, within the adiabatic approximation to the exchange-correlation (xc) kernel, the calculated excitation energies have a strict single-excitation character and are fewer than the real ones. A frequency-dependent xc kernel could create extra poles in the response function, which would describe states with a multiple-excitation character. We introduce a frequency-dependent xc kernel, which can reproduce, within TDDFT, double excitations in finite systems. In order to achieve this, we use the Bethe-Salpeter equation with a dynamically screened Coulomb interaction W(omega), which can describe these excitations, and from this we obtain the xc kernel. Using a two-electron model system, we show that the frequency dependence of W does indeed introduce the double excitations that are instead absent in any static approximation of the electron-hole screening.

  4. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  5. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... Standards for Grades of Bermuda-Granex-Grano Type Onions Definitions § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  6. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  7. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  8. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  9. 7 CFR 51.3207 - Doubles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Doubles. 51.3207 Section 51.3207 Agriculture... Standards for Grades of Bermuda-Granex-Grano Type Onions Definitions § 51.3207 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  10. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  11. 7 CFR 51.2846 - Doubles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Doubles. 51.2846 Section 51.2846 Agriculture... Creole Types) Definitions § 51.2846 Doubles. Doubles means onions which have developed more than one distinct bulb joined only at the base....

  12. Single electron pumping in InAs nanowire double quantum dots

    NASA Astrophysics Data System (ADS)

    Fuhrer, A.; Fasth, C.; Samuelson, L.

    2007-07-01

    Closely spaced local gate electrodes are used to electrically define a double quantum dot along an InAs nanowire crystal. By applying a periodic pulse sequence to two plunger gate electrodes controlling the double quantum dot charge configuration, the device is operated as a single electron pump. The authors find that within measurement accuracy, the pumping current equals one electron per cycle for frequencies up to 2MHz, demonstrating the suitability of nanowire based quantum dots for pumping applications.

  13. Measuring Visual Double Stars with Robotic Telescopes

    NASA Astrophysics Data System (ADS)

    Boyce, Pat; Boyce, Grady; Genet, Russell M.; Faisal Al-Zaben, Dewei Li, Yongyao Li, Aren Dennis, Zhixin Cao, Junyao Li, Steven Qu, Jeff Li, Michael Fene, Allen Priest, Stephen Priest, Rex Qiu, , and, Bill Riley

    2016-06-01

    The Astronomy Research Seminars introduce students to scientific research by carrying out the entire process: planning a scientific research project, writing a research proposal, gathering and analyzing observational data, drawing conclusions, and presenting the research results in a published paper and presentation.In 2015 Cuesta College and Russell Genet sponsored a new hybrid format for the seminar enabling distance learning. Boyce Research Initiatives and Education Foundation (BRIEF) conducted the course at The Army and Navy Academy (ANA) in Carlsbad, California, in the spring and fall of 2015.The course objective is to complete the research and publish the paper within one semester. Our program schedule called for observations to be performed within a two week period. Measurement of visual binary stars was chosen because sufficient observations could be made in just two evenings of good weather. We quickly learned that our location by the ocean did not provide reliable weather to use local telescopes.The iTelescope network of robotic telescopes located in Australia, Spain and the U.S. solved the problem. Reservations for these systems are booked online and include date, time, exposure and filters. The high quality telescopes range from 4" to 27" in size with excellent cameras. By watching the weather forecasts for the sites, we were able to schedule our observations within the two week time frame required.Timely and reliable data reduction was the next hurdle. The students were using widely varying equipment (PCs, MACs, tablets, smart phones) with incompatible software. After wasting time trying to be computer technicians, we settled a on standard set of software relying on Mirametrics' Mira Pro x64. We installed the software on an old laptop, downloaded the iTelescope data files, gave the students remote access using GoToMyPC.These efficiencies enabled us to meet the demanding one semester schedule and assure a better learning experience. We have been able to

  14. Modelling the nonlinear behaviour of double walled carbon nanotube based resonator with curvature factors

    NASA Astrophysics Data System (ADS)

    Patel, Ajay M.; Joshi, Anand Y.

    2016-10-01

    This paper deals with the nonlinear vibration analysis of a double walled carbon nanotube based mass sensor with curvature factor or waviness, which is doubly clamped at a source and a drain. Nonlinear vibrational behaviour of a double-walled carbon nanotube excited harmonically near its primary resonance is considered. The double walled carbon nanotube is harmonically excited by the addition of an excitation force. The modelling involves stretching of the mid plane and damping as per phenomenon. The equation of motion involves four nonlinear terms for inner and outer tubes of DWCNT due to the curved geometry and the stretching of the central plane due to the boundary conditions. The vibrational behaviour of the double walled carbon nanotube with different surface deviations along its axis is analyzed in the context of the time response, Poincaré maps and Fast Fourier Transformation diagrams. The appearance of instability and chaos in the dynamic response is observed as the curvature factor on double walled carbon nanotube is changed. The phenomenon of Periodic doubling and intermittency are observed as the pathway to chaos. The regions of periodic, sub-harmonic and chaotic behaviour are clearly seen to be dependent on added mass and the curvature factors in the double walled carbon nanotube. Poincaré maps and frequency spectra are used to explicate and to demonstrate the miscellany of the system behaviour. With the increase in the curvature factor system excitations increases and results in an increase of the vibration amplitude with reduction in excitation frequency.

  15. The redoubtable ecological periodic table

    EPA Science Inventory

    Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

  16. Doubly Resonant Optical Periodic Structure

    PubMed Central

    Alagappan, G.; Png, C. E.

    2016-01-01

    Periodic structures are well known in various branches of physics for their ability to provide a stopband. In this article, using optical periodic structures we showed that, when a second periodicity – very closed to the original periodicity is introduced, large number of states appears in the stopband corresponding to the first periodicity. In the limit where the two periods matches, we have a continuum of states, and the original stopband completely disappears. This intriguing phenomena is uncovered by noticing that, regardless of the proximities of the two periodicities, there is an array of spatial points where the dielectric functions corresponding to the two periodicities interfere destructively. These spatial points mimic photonic atoms by satisfying the standards equations of quantum harmonic oscillators, and exhibit lossless, atom-like dispersions. PMID:26853945

  17. Doubly Resonant Optical Periodic Structure.

    PubMed

    Alagappan, G; Png, C E

    2016-02-08

    Periodic structures are well known in various branches of physics for their ability to provide a stopband. In this article, using optical periodic structures we showed that, when a second periodicity--very closed to the original periodicity is introduced, large number of states appears in the stopband corresponding to the first periodicity. In the limit where the two periods matches, we have a continuum of states, and the original stopband completely disappears. This intriguing phenomena is uncovered by noticing that, regardless of the proximities of the two periodicities, there is an array of spatial points where the dielectric functions corresponding to the two periodicities interfere destructively. These spatial points mimic photonic atoms by satisfying the standards equations of quantum harmonic oscillators, and exhibit lossless, atom-like dispersions.

  18. Heat generation in double layer capacitors

    NASA Astrophysics Data System (ADS)

    Schiffer, Julia; Linzen, Dirk; Sauer, Dirk Uwe

    Thermal management is a key issue concerning lifetime and performance of double layer capacitors and battery technologies. Double layer capacitor modules for hybrid vehicles are subject to heavy duty cycling conditions and therefore significant heat generation occurs. High temperature causes accelerated aging of the double layer capacitors and hence reduced lifetime. To investigate the thermal behavior of double layer capacitors, thermal measurements during charge/discharge cycles were performed. These measurements show that heat generation in double layer capacitors is the superposition of an irreversible Joule heat generation and a reversible heat generation caused by a change in entropy. A mathematical representation of both parts is provided.

  19. 76 FR 297 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of proposed... a proposed change in certain analytical methods used in periodic reporting. This action responds to... proceeding to consider changes in the analytical methods approved for use in periodic reporting.\\1\\...

  20. 75 FR 1301 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-11

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Proposed rule... rulemaking proceeding to consider changes in the analytical methods approved for use in periodic reporting.\\1... Docket No. RM2009-10, Order on Analytical Principles Used in Periodic Reporting (Proposals Three...

  1. Double Engine for a Nebula

    NASA Astrophysics Data System (ADS)

    2009-08-01

    ESO has just released a stunning new image of a field of stars towards the constellation of Carina (the Keel). This striking view is ablaze with a flurry of stars of all colours and brightnesses, some of which are seen against a backdrop of clouds of dust and gas. One unusual star in the middle, HD 87643, has been extensively studied with several ESO telescopes, including the Very Large Telescope Interferometer (VLTI). Surrounded by a complex, extended nebula that is the result of previous violent ejections, the star has been shown to have a companion. Interactions in this double system, surrounded by a dusty disc, may be the engine fuelling the star's remarkable nebula. The new image, showing a very rich field of stars towards the Carina arm of the Milky Way, is centred on the star HD 87643, a member of the exotic class of B[e] stars [1]. It is part of a set of observations that provide astronomers with the best ever picture of a B[e] star. The image was obtained with the Wide Field Imager (WFI) attached to the MPG/ESO 2.2-metre telescope at the 2400-metre-high La Silla Observatory in Chile. The image shows beautifully the extended nebula of gas and dust that reflects the light from the star. The central star's wind appears to have shaped the nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years. A team of astronomers, led by Florentin Millour, has studied the star HD 87643 in great detail, using several of ESO's telescopes. Apart from the WFI, the team also used ESO's Very Large Telescope (VLT) at Paranal. At the VLT, the astronomers used the NACO adaptive optics instrument, allowing them to obtain an image of the star free from the blurring effect of the atmosphere. To probe the object further, the team then obtained an image with the Very Large Telescope Interferometer (VLTI). The sheer range of this set of observations

  2. New insight on double-double radio galaxies

    NASA Astrophysics Data System (ADS)

    Nandi, Sumana

    2016-07-01

    Striking examples of episodic jet activity in active galactic nuclei (AGN) are the double-double radio galaxies (DDRGs) with two pairs of lobes emerging from the same central engine. The number of DDRGs reported so far is very limited, and it is important to identify more of these to provide a significant statistical overview of the conditions to trigger the jets and the role of jets in terms of feedback mechanisms that affect the host galaxies. Although most DDRGs were believed initially to be giant radio sources with sizes more than a Mpc, a significant number of smaller sized candidate DDRGs have also been identified in our recent study. We started GMRT observation of this sample to confirm that the sources are related to distinct epochs of nuclear activity. In addition to this radio observation we have also investigated the properties of the host galaxies and their environments to understand the triggering mechanisms for recurrent jet emission. Here, I will highlight the main results from these observations and discuss on the possible scenarios responsible for the episodic activity in different types of DDRGs .

  3. Enhanced nonlinear susceptibility via double-double electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Alotaibi, Hessa M. M.; Sanders, Barry C.

    2016-11-01

    We investigate the nonlinear optical susceptibility of an alkali-metal atom with tripod electronic configuration responsible for generating cross-phase modulation and self-phase modulation under the condition of double-double electromagnetically induced transparency. Our investigation demonstrates an enhancement in the nonlinear optical susceptibility of an alkali-metal atom by a factor of 1000 in the region of the second transparency window. This enhancement is in comparison with the atom's susceptibility in the first transparency window for the same parameters under the same conditions. Nonlinear-absorption enhancement arises by canceling Raman-gain generation, which arises when the probe and signal fields have equal intensities. At the center of the second transparency window, we obtain the condition required to attain a nonvanishing nonlinear optical susceptibility. In the bare-state picture, the coupling field must be off resonant from a bare-to-bare-state transition, while working in the semiclassical dressed picture required the signal field to be tuned off resonantly with a bare-to-dressed-state transition. The relation that governs the values of coupling- and signal-field detuning are also obtained. Our scheme exhibits the fact that the second transparency window has advantages over the first transparency window with respect to obtaining an enhanced Kerr effect, and our calculation includes simulation of both low-temperature and Doppler-broadened regimes.

  4. Underprepared Students' Performance on Algebra in a Double-Period High School Mathematics Program

    ERIC Educational Resources Information Center

    Martinez, Mara V.; Bragelman, John; Stoelinga, Timothy

    2016-01-01

    The primary goal of the Intensified Algebra I (IA) program is to enable mathematically underprepared students to successfully complete Algebra I in 9th grade and stay on track to meet increasingly rigorous high school mathematics graduation requirements. The program was designed to bring a range of both cognitive and non-cognitive supports to bear…

  5. Booster Double Harmonic Setup Notes

    SciTech Connect

    Gardner, C. J.

    2015-02-17

    The motivation behind implementing a booster double harmonic include the reduced transverse space charge force from a reduced peak beam current and reduced momentum spread of the beam, both of which can be achieved from flattening the RF bucket. RF capture and acceleration of polarized protons (PP) is first set up in the single harmonic mode with RF harmonic h=1. Once capture and acceleration have been set up in the single harmonic mode, the second harmonic system is brought on and programmed to operate in concert with the single harmonic system.

  6. Primary repair of sternal cleft with a double osteochondroplasty flap

    PubMed Central

    Ballouhey, Quentin; Armendariz, Mateo; Vacquerie, Virginie; Marcheix, Pierre Sylvain; Berenguer, Daniel; Mouliès, Dominique; Fourcade, Laurent

    2013-01-01

    Sternal cleft is a rare congenital malformation affecting the anterior part of the chest wall. Surgical closure is recommended. It should be done early during the neonatal period because of the chest's flexibility. Associated abnormalities may have been previously excluded. Different surgical repairs have been described, but none has been proved to be superior to the others. We present the description of 2 cases managed with an original surgical technique. After dissecting the two sternal bars, they were approximated with several intercostal sutures under close cardiac and respiratory monitoring. A double perichondrium flap technique was then used and resulted in a double perichondrium layer. This technique is suitable for most cases and offers satisfying anatomical restoring and cosmetic results. PMID:23956263

  7. Testing Common Envelopes on Double White Dwarf Binaries

    NASA Astrophysics Data System (ADS)

    Nandez, Jose L. A.; Ivanova, Natalia; Lombardi, James C., Jr.

    2015-06-01

    The formation of a double white dwarf binary likely involves a common envelope (CE) event between a red giant and a white dwarf (WD) during the most recent episode of Roche lobe overflow mass transfer. We study the role of recombination energy with hydrodynamic simulations of such stellar interactions. We find that the recombination energy helps to expel the common envelope entirely, while if recombination energy is not taken into account, a significant fraction of the common envelope remains bound. We apply our numerical methods to constrain the progenitor system for WD 1101+364 - a double WD binary that has well-measured mass ratio of q=0.87±0.03 and an orbital period of 0.145 days. Our best-fit progenitor for the pre-common envelope donor is a 1.5 ⊙ red giant.

  8. Double outlet right ventricle. Study of 27 cases.

    PubMed Central

    Cameron, A H; Acerete, F; Quero, M; Castro, M C

    1976-01-01

    Out of 1610 children's hearts with congenital malformations there were 27 specimens showing double outlet right ventricle. Cases with dextrocardia, situs inversus, or l-venticular loop were excluded. Anatomical examination was performed with particular reference to the infundibular region, the great vessels, and the ventricular septum. The commonest associated malformations were ventricular septal defect and pulmonary stenosis. Aortic stenosis was the predominant finding in those cases dying in the neonatal period. An aortic conus was associated with pulmonary stenosis, ventricular septal defect, and d-transposition, a pulmonary conus with ventricular septal defect and a double conus with stenosis of either great vessel. The anterior vessel always had a muscular conus and the posterior vessel was commonly stenotic. Images PMID:1008954

  9. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, Hannes

    1986-01-01

    As the rate of energy release in a double layer with voltage delta V is P approx I delta V, a double layer must be treated as a part of a circuit which delivers the current I. As neither double layer nor circuit can be derived from magnetofluid models of a plasma, such models are useless for treating energy transfer by means of double layers. They must be replaced by particle models and circuit theory. A simple circuit is suggested which is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object (one example is the double radio sources). It is tentatively suggested in X-ray and Gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). A study of how a number of the most used textbooks in astrophysics treat important concepts like double layers, critical velocity, pinch effects and circuits is made.

  10. Double-Front Detonation Waves

    NASA Astrophysics Data System (ADS)

    Gubin, S. A.; Sumskoi, S. I.; Victorov, S. B.

    According to the theory of detonation, in a detonation wave there is a sound plane, named Chapman-Jouguet (CJ) plane. There are certain stationary parameters for this plane. In this work the possibility of the second CJ plane is shown. This second CJ plane is stationary as well. The physical mechanism of non-equilibrium transition providing the existence of the second CJ plane is presented. There is a non-equilibrium state, when the heat is removed from the reaction zone and the heat capacity decreases sharply. As a result of this non-equilibrium state, the sound velocity increases, and the local supersonic zone with second sonic plane (second CJ plane) appears. So the new mode of detonation wave is predicted. Equations describing this mode of detonation are presented. The exact analytical solution for the second CJ plane parameters is obtained. The example of double-front detonation in high explosive (TNT) is presented. In this double-front structure "nanodiamond-nanographite" phase transition takes place in condensed particles of detonation products.

  11. Double-diffusive layer formation

    NASA Astrophysics Data System (ADS)

    Zaussinger, Florian; Kupka, Friedrich; Hücker, Sebastian; Egbers, Christoph

    2015-04-01

    Double-diffusive convection plays an important role in geo- and astrophysical applications. The special case, where a destabilising temperature gradient counteracts a stabilising solute gradient leads to layering phenomena under certain conditions. Convectively mixed layers sandwiched in diffusive interfaces form a so-called stack. Well-known double-diffusive systems are observed in rift lakes in Africa and even from the coffee drink Latte Macciatto. Stacks of layers are also predicted to occur inside massive stars and inside giant planets. Their dynamics depend on the thermal, the solute and the momentum diffusivities, as well on the ratio of the gradients of the opposing stratifications. Since the layering process cannot be derived from linear stability analysis, the full nonlinear set of equations has to be investigated. Numerical simulations have become feasible for this task, despite the physical processes operate on a vast range of length and time scales, which is challenging for numerical hydrodynamical modelling. The oceanographically relevant case of fresh and salty water is investigated here in further details. The heat and mass transfer is compared with theoretical results and experimental measurements. Additionally, the initial dynamic of layering, the transient behaviour of a stack and the long time evolution are presented using the example of Lake Kivu and the interior of a giant planet.

  12. Vesicles with a double bilayer.

    PubMed

    Zawada, Zygmunt H

    2004-01-01

    A modified reverse phase evaporation method was used to prepare intermediate unilamellar vesicles coated with an additional membrane, or large vesicles in which several vesicles were coated with a common membrane. In both kinds of vesicle, the outer and inner membranes are usually of different phospholipid composition. The preparation involves the formation of a double emulsion: vesicles in a buffer are emerged in a low-boiling point organic solution of phospholipids. Then the organic solvent is evaporated during the heating and mixing process. As result large unilamellar vesicles (LUVs), about 100 nm in diameter, were coated with an additional membrane from egg lecithin or dipalmitoylphosphatidylcholine and cholesterol. The highest yield of the coating was about 50%. When DPPC was used for coating above the phase transition temperature Tm, the data suggested the formation of vesicles that were slightly larger than the starting LUVs. It might be concluded that many of these had a double bilayer. If the coating was done below Tm, the micrographs suggested the formation of structures resembling multi-vesicular vesicles. They looked like LUV clusters coated with a common membrane.

  13. Double Exposure: Photographing Climate Change

    NASA Astrophysics Data System (ADS)

    Arnold, D. P.; Wake, C. P.; Romanow, G. B.

    2008-12-01

    Double Exposure, Photographing Climate Change, is a fine-art photography exhibition that examines climate change through the prism of melting glaciers. The photographs are twinned shots of glaciers, taken in the mid-20th century by world-renowned photographer Brad Washburn, and in the past two years by Boston journalist/photographer David Arnold. Arnold flew in Washburn's aerial "footprints", replicating stunning black and white photographs, and documenting one irreversible aspect of climate change. Double Exposure is art with a purpose. It is designed to educate, alarm and inspire its audiences. Its power lies in its beauty and the shocking changes it has captured through a camera lens. The interpretive text, guided by numerous experts in the fields of glaciology, global warming and geology, helps convey the message that climate change has already forced permanent changes on the face of our planet. The traveling exhibit premiered at Boston's Museum of Science in April and is now criss-crossing the nation. The exhibit covers changes in the 15 glaciers that have been photographed as well as related information about global warming's effect on the planet today.

  14. ATHLETE : Double Auger Anchoring Mechanism

    NASA Technical Reports Server (NTRS)

    Shin, Joseph

    2011-01-01

    The All-Terrain Hex-Legged Extra-Terrestrial Explorer (ATHLETE) is a six-limbed robot designed to support surface explorations on Near Earth Objects, the Moon and Mars. ATHLETE can carry large payloads on its top deck and can carry a fully equipped pressurized habitat in low gravity. The robot has wheels on each of its six articulated limbs, allowing it to actively conform to terrain while driving and to walk when driving is impractical. With the use of a tool adapter, ATHLETE limbs can be equipped with end effectors to support various mission objectives. For work on Near Earth Objects and other microgravity environments, an anchoring mechanism is needed to keep the ATHLETE from floating off the surface. My goal for this spring session at JPL was to design and build a counter rotating, double auger, anchoring mechanism. The mechanism mates to the tool adapter and is driven off the wheel motor. The double auger anchoring mechanism will be tested in a regolith simulant that will determine the uplift capacity of the anchoring mechanism.

  15. Infinite sets and double binds.

    PubMed

    Arden, M

    1984-01-01

    There have been many attempts to bring psychoanalytical theory up to date. This paper approaches the problem by discussing the work of Gregory Bateson and Ignacio Matte-Blanco, with particular reference to the use made by these authors of Russell's theory of logical types. Bateson's theory of the double bind and Matte-Blanco's bilogic are both based on concepts of logical typing. It is argued that the two theories can be linked by the idea that neurotic symptoms are based on category errors in thinking. Clinical material is presented from the analysis of a middle-aged woman. The intention is to demonstrate that the process of making interpretations can be thought of as revealing errors in thinking. Changes in the patient's inner world are then seen to be the result of clarifying childhood experiences based on category errors. Matte-Blanco's theory of bilogic and infinite experiences is a re-evaluation of the place of the primary process in mental life. It is suggested that a combination of bilogic and double bind theory provides a possibility of reformulating psychoanalytical theory.

  16. Double Standards in Global Health

    PubMed Central

    Admay, Catherine; Shakow, Aaron; Keshavjee, Salmaan

    2016-01-01

    Abstract The human rights arguments that underpinned the fight against HIV over the last three decades were poised, but ultimately failed, to provide a similar foundation for success against multidrug-resistant TB (MDR-TB) and other diseases of the poor. With more than 1.5 million deaths since 2000 attributed to strains of MDR-TB, and with half a million new, and mostly untreated, MDR-TB cases in the world each year, the stakes could not be higher. The World Health Organization (WHO), whose mandate is to champion the attainment by all peoples of the highest possible level of health, recommended unsound medical treatment for MDR-TB patients in resource-poor settings from 1993-2002. Citing cost considerations, WHO did not recommend the available standard of care that had been successfully used to contain and defeat MDR-TB in rich countries. By acting as a strategic gatekeeper in its technical advisory role to donor agencies and countries, it also facilitated the global implementation of a double standard for TB care in low- and middle-income countries (LMICs), upending important legal and scientific priorities. This raises serious questions about whether the organization violated international human rights standards and those established in its own constitution. While calling for additional analysis and discussion on this topic, the authors propose that policymakers should reject double standards of this kind and instead embrace the challenge of implementing the highest standard of care on a global level. PMID:27781001

  17. Double Photoionization of Atomic Beryllium

    NASA Astrophysics Data System (ADS)

    Yip, Frank L.; McCurdy, C. William; Rescigno, Thomas N.

    2010-03-01

    One-photon double ionization (DPI) of beryllium represents the next step in the evolution of DPI investigations that began with helium in order to sensitively probe electron correlation. Beryllium is the simplest atomic species of the alkaline earth elements which, in general, possess two electrons outside of a fully occupied inner shell that spherically screens the nucleus. This provides a natural basis for comparison to 1s^2 helium DPI. However, the valence state of beryllium has n=2, thus making the valence excited target 2s2p more accessible relative to the 2s^2 ground state as compared to ground-state and metastable helium. Also, the symmetry of photoionizing from either the ^1S or ^1P initial state will have consequences for the angular distributions for double ionization. Triply differential cross sections (TDCS) are presented for DPI from both ground state 2s^2 and excited state 2s2p beryllium calculated using exterior complex scaling (ECS) for the valence electrons.

  18. Mars Double-Flyby Free Returns

    NASA Technical Reports Server (NTRS)

    Jesick, Mark

    2015-01-01

    A subset of Earth-originating Mars double-flyby ballistic trajectories is documented. The subset consists of those trajectories that, after the first Mars flyby, perform a half-revolution transfer with Mars before returning to Earth. This class of free returns is useful for both human and robotic Mars missions because of its low geocentric energy at departure and arrival, and because of its extended stay time in the vicinity of Mars. Ballistic opportunities are documented over Earth departure dates ranging from 2015 through 2100. The mission is viable over three or four consecutive Mars synodic periods and unavailable for the next four, with the pattern repeating approximately every 15 years. Over the remainder of the century, a minimum Earth departure hyperbolic excess speed of 3.16 km/s, a minimum Earth atmospheric entry speed of 11.47 km/s, and a minimum flight time of 904 days are observed. The algorithm used to construct these trajectories is presented along with several examples.

  19. Repair of DNA Double-Strand Breaks

    NASA Astrophysics Data System (ADS)

    Falk, Martin; Lukasova, Emilie; Kozubek, Stanislav

    The genetic information of cells continuously undergoes damage induced by intracellular processes including energy metabolism, DNA replication and transcription, and by environmental factors such as mutagenic chemicals and UV and ionizing radiation. This causes numerous DNA lesions, including double strand breaks (DSBs). Since cells cannot escape this damage or normally function with a damaged genome, several DNA repair mechanisms have evolved. Although most "single-stranded" DNA lesions are rapidly removed from DNA without permanent damage, DSBs completely break the DNA molecule, presenting a real challenge for repair mechanisms, with the highest risk among DNA lesions of incorrect repair. Hence, DSBs can have serious consequences for human health. Therefore, in this chapter, we will refer only to this type of DNA damage. In addition to the biochemical aspects of DSB repair, which have been extensively studied over a long period of time, the spatio-temporal organization of DSB induction and repair, the importance of which was recognized only recently, will be considered in terms of current knowledge and remaining questions.

  20. From Periodic Properties to a Periodic Table Arrangement

    ERIC Educational Resources Information Center

    Besalú, Emili

    2013-01-01

    A periodic table is constructed from the consideration of periodic properties and the application of the principal components analysis technique. This procedure is useful for objects classification and data reduction and has been used in the field of chemistry for many applications, such as lanthanides, molecules, or conformers classification.…

  1. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 Housing and Urban Development Regulations Relating to Housing and...

  2. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 Housing and Urban Development Regulations Relating to Housing and...

  3. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 Housing and Urban Development Regulations Relating to Housing and...

  4. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 Housing and Urban Development Regulations Relating to Housing and...

  5. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 Housing and Urban Development Regulations Relating to Housing and...

  6. Gender Double Standards in Parenting Attitudes*

    PubMed Central

    Axinn, William G.; Young-DeMarco, Linda; Ro, Meeso Caponi

    2010-01-01

    This paper investigates the double standard in attitudes toward courtship and family formation behaviors of sons and daughters. We argue there are strong theoretical reasons to expect that the magnitude of this double standard varies across substantive domains, as well as amongst parents and non-parents. We also argue key methodological limitations of previous studies likely produce an under-estimate of the gender double standard. We provide empirical estimates of the gender double standard that overcome these limitations, including a random assignment experiment explicitly designed to control the effects of social desirability. These estimates demonstrate variability in the double standard across domains and reveal key factors contributing to the magnitude of the double standards in parenting attitudes held by individuals. PMID:21318125

  7. Double-Swivel Mechanism For Reliable Release

    NASA Technical Reports Server (NTRS)

    King, Guy L.; Schneider, William C.

    1990-01-01

    Double-swivel toggle mechanism releases large, heavy objects reliably. Double-swiveling action of mechanism ensures it clears restraining pins upon release. Pins retain toggle and its load. If pin fails to withdraw at designated time for releasing payload, toggle swivels about its upper ball, and ring swivels about lower ball so ring flange clears failed pin. Double-swivel action ensures disengagement even it two pins fail to withdraw.

  8. Constitutive Parameter Measurement Using Double Ridge Waveguide

    DTIC Science & Technology

    2013-03-01

    CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Nathan J. Lehman, Captain, USAF AFIT-ENG-13-M-30 DEPARTMENT OF THE AIR FORCE...copyright protection in the United States. AFIT-ENG-13-M-30 CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Presented to the Faculty...PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE Nathan J. Lehman, B.S.E.E. Captain, USAF Approved: Michael Havrilla, PhD (Chairman) Maj Milo Hyde, PhD

  9. Change of coagulation parameters after double plateletpheresis.

    PubMed

    Yilmaz, Mustafa; Dikmen, Tamer; Sonmez, Mehmet; Akdogan, Elif; Durmus, Ahmet; Omay, Serdar Bedii; Ovali, Ercument

    2007-10-01

    In the previous studies, some authors reported that automated apheresis leads to a hypercoagulable state. We tried to find out changes in coagulation parameters after double plateletpheresis in this study. Forty-five donors were recruited to the study, and coagulation parameters were assessed before and after double plateletpheresis. After double plateletpheresis, fibrinogen, factor V, factor VIII and factor IX were decreased compared with the values before apheresis. Although serum levels of this coagulation parameters are decreasing, they are still in the normal limits. Therefore, we suggest that double plateletpheresis is a safe procedure for healthy volunteers taking into account these coagulation parameters.

  10. Controlled double-slit electron diffraction

    NASA Astrophysics Data System (ADS)

    Bach, Roger; Pope, Damian; Liou, Sy-Hwang; Batelaan, Herman

    2013-03-01

    Double-slit diffraction is a corner stone of quantum mechanics. It illustrates key features of quantum mechanics: interference and the particle-wave duality of matter. In 1965, Richard Feynman presented a thought experiment to show these features. Here we demonstrate the full realization of his famous thought experiment. By placing a movable mask in front of a double-slit to control the transmission through the individual slits, probability distributions for single- and double-slit arrangements were observed. Also, by recording single electron detection events diffracting through a double-slit, a diffraction pattern was built up from individual events.

  11. William Doberck - double star astronomer

    NASA Astrophysics Data System (ADS)

    MacKeown, P. Kevin

    2007-03-01

    We outline the role of astronomy in the career of William Doberck (1852-1941). After taking a PhD in astronomy at the University of Jena in 1873, he accepted a position as superintendent of Markree Observatory in the west of Ireland. There he refurbished the great 13-inch refractor and spent nine years observing mostly double star systems, paying only such attention to meteorological monitoring as was required of his position. In 1883 he became the founding Director of a new observatory in Hong Kong, a post which he held for 24 years. His frustrations in attempting to continue his purely astronomical work, not assuaged by his combative and prickly personality, and in the face of the strictly practical demands of that mercantile society for comprehensive storm forecasting, are described. Finally, his observations in retirement in England, and his overall contribution to astronomy, are summarised.

  12. Double photoionization of halogenated benzene

    SciTech Connect

    AlKhaldi, Mashaal Q.; Wehlitz, Ralf

    2016-01-28

    We have experimentally investigated the double-photoionization process in C{sub 6}BrF{sub 5} using monochromatized synchrotron radiation. We compare our results with previously published data for partially deuterated benzene (C{sub 6}H{sub 3}D{sub 3}) over a wide range of photon energies from threshold to 270 eV. A broad resonance in the ratio of doubly to singly charged parent ions at about 65 eV appears shifted in energy compared to benzene data. This shift is due to the difference in the bond lengths in two molecules. A simple model can explain the shape of this resonance. At higher photon energies, we observe another broad resonance that can be explained as a second harmonic of the first resonance.

  13. Doubling bialgebras of rooted trees

    NASA Astrophysics Data System (ADS)

    Mohamed, Mohamed Belhaj; Manchon, Dominique

    2017-01-01

    The vector space spanned by rooted forests admits two graded bialgebra structures. The first is defined by Connes and Kreimer using admissible cuts, and the second is defined by Calaque, Ebrahimi-Fard and the second author using contraction of trees. In this article, we define the doubling of these two spaces. We construct two bialgebra structures on these spaces which are in interaction, as well as two related associative products obtained by dualization. We also show that these two bialgebras verify a commutative diagram similar to the diagram verified Calaque, Ebrahimi-Fard and the second author in the case of rooted trees Hopf algebra, and by the second author in the case of cycle-free oriented graphs.

  14. Double Compton scatter telescope calibration

    NASA Technical Reports Server (NTRS)

    Dayton, B.; Simone, J.; Green, M.; Long, J.; Zanrosso, E.; Zych, A. D.; White, R. S.

    1981-01-01

    Calibration techniques for a medium energy gamma ray telescope are described. Gain calibration using Compton edge spectra involves comparisons of pulse height spectra with spectra simulated by a Monte Carlo computer code which includes Compton scattering and pair production, plural scattering and variable energy resolution, and cell size. The telescope considered comprises 56 cells of liquid scintillator in four size groups, with a total liquid volume of 325 l; each cell has its own photomultiplier tube. Energy and angular resolutions and the PMT gain calibration procedure are verified with double scatter data for monoenergetic gamma rays at a known location. Detection probabilities for any cell combination in the two telescope arrays are calculated per steradian as a function of the scattering for a number of different energies with a Van de Graaff accelerator.

  15. Rich dynamic of a stage-structured prey-predator model with cannibalism and periodic attacking rate

    NASA Astrophysics Data System (ADS)

    Zhang, Limin; Zhang, Chaofeng

    2010-12-01

    The dynamic behavior of a stage-structure prey-predator model with cannibalism for prey and periodic attacking rate for predator is investigated. Firstly, the permanence, locally and globally asymptotic stability analyses of the model with constant attacking rate are explored. After that, sufficient conditions for the permanence of the corresponding nonautonomous system with periodic attacking rate are obtained. Furthermore, numerical simulations are presented to illustrate the effects of periodic attacking rate. Simulation results show that the system with periodic attacking rate shows a rich behaviors, including period-doubling and period-having bifurcations, chaos and windows of periodicity.

  16. 75 FR 7426 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-19

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Advance notice of...-789-6820 or stephen.sharfman@prc.gov . SUPPLEMENTARY INFORMATION: Table of Contents I. Background II... approved for use in periodic reporting.\\1\\ The Postal Service labels its proposal ``Proposal One''...

  17. 76 FR 296 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... consider a proposed change in certain analytical methods used in periodic reporting. The proposed change... rulemaking proceeding to consider changes in the analytical methods approved for use in periodic reporting.\\1... Requesting Initiation of a Proceeding to Consider Proposed Changes in Analytic Principles (Proposals...

  18. Forward Period Analysis Method of the Periodic Hamiltonian System

    PubMed Central

    Wang, Pengfei

    2016-01-01

    Using the forward period analysis (FPA), we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit) solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT) scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested. PMID:27727295

  19. Meige syndrome: double-blind crossover study of sodium valproate.

    PubMed Central

    Snoek, J W; van Weerden, T W; Teelken, A W; van den Burg, W; Lakke, J P

    1987-01-01

    A double-blind crossover study of sodium valproate and placebo was conducted in five patients with Meige syndrome. CSF neurotransmitter studies were performed at the end of each treatment period. GABA levels were not influenced by the administration of sodium valproate. An increase in HVA levels was observed in every patient, which may reflect an increase in central dopaminergic activity. This finding may explain the trend towards clinical deterioration which was observed during treatment with sodium valproate. Sodium valproate appears to be ineffective in Meige syndrome. PMID:3121795

  20. Double Incomplete Internal Biliary Fistula: Coexisting Cholecystogastric and Cholecystoduodenal Fistula

    PubMed Central

    Beksac, Kemal; Erkan, Arman; Kaynaroglu, Volkan

    2016-01-01

    Internal biliary fistula is a rare complication of a common surgical disease, cholelithiasis. It is seen in 0.74% of all biliary tract surgeries and is thought to be a result of repeated inflammatory periods of the gallbladder. In this report we present a case of incomplete cholecystogastric and cholecystoduodenal fistulae in a single patient missed by ultrasonography and endoscopic retrograde cholangiopancreatography and diagnosed intraoperatively. In the literature there is only one report of an incomplete cholecystogastric fistula. To our knowledge this is the first case of double incomplete internal biliary fistulae. PMID:26904348

  1. Congenital Double Lip: A Rare Deformity Treated Surgically

    PubMed Central

    Aggarwal, Titiksha; Chawla, Kirti; Lamba, Arundeep Kaur; Faraz, Farukh; Tandon, Shruti

    2016-01-01

    Lip is an important aspect of facial features affecting ones personality. A deformity of the lip characterized by excessive tissue sagging below the usual giving it thicker wider appearance is referred to as double lip. It is a rare occurrence with a proposed male predilection. This article is a report of a 20 years old male with this deformity who presented with the complaint of difficult speech and poor aesthetics. There was no other history patient being systemically healthy. It was successively treated with a simple surgical technique without recurrence over a period of 12 months. PMID:27853696

  2. Observations of double layers in earth's plasma sheet.

    PubMed

    Ergun, R E; Andersson, L; Tao, J; Angelopoulos, V; Bonnell, J; McFadden, J P; Larson, D E; Eriksson, S; Johansson, T; Cully, C M; Newman, D N; Goldman, M V; Roux, A; LeContel, O; Glassmeier, K-H; Baumjohann, W

    2009-04-17

    We report the first direct observations of parallel electric fields (E_{ parallel}) carried by double layers (DLs) in the plasma sheet of Earth's magnetosphere. The DL observations, made by the THEMIS spacecraft, have E_{ parallel} signals that are analogous to those reported in the auroral region. DLs are observed during bursty bulk flow events, in the current sheet, and in plasma sheet boundary layer, all during periods of strong magnetic fluctuations. These observations imply that DLs are a universal process and that strongly nonlinear and kinetic behavior is intrinsic to Earth's plasma sheet.

  3. Photonic crystal fiber long-period gratings for biochemical sensing.

    PubMed

    Rindorf, Lars; Jensen, Jesper B; Dufva, Martin; Pedersen, Lars Hagsholm; Høiby, Poul Erik; Bang, Ole

    2006-09-04

    We present experimental results showing that long-period gratings in photonic crystal fibers can be used as sensitive biochemical sensors. A layer of biomolecules was immobilized on the sides of the holes of the photonic crystal fiber and by observing the shift in the resonant wavelength of a long-period grating it was possible to measure the thickness of the layer. The long-period gratings were inscribed in a large-mode area silica photonic crystal fiber with a CO2 laser. The thicknesses of a monolayer of poly-L-lysine and double-stranded DNA was measured using the device. We find that the grating has a sensitivity of approximately 1.4nm/1nm in terms of the shift in resonance wavelength in nm per nm thickness of biomolecule layer.

  4. Periodic and Quasi-Periodic Orbitsfor the Standard Map

    NASA Astrophysics Data System (ADS)

    Berretti, Alberto; Gentile, Guido

    We consider both periodic and quasi-periodic solutions for the standard map, and we study the corresponding conjugating functions, i.e. the functions conjugating the motions to trivial rotations. We compare the invariant curves with rotation numbers ω satisfying the Bryuno condition and the sequences of periodic orbits with rotation numbers given by their convergents ωN = pN/qN. We prove the following results for N--> ∞: (1) for rotation numbers ωNN we study the radius of convergence of the conjugating functions and we find lower bounds on them, which tend to a limit which is a lower bound on the corresponding quantity for ω (2) the periodic orbits consist of points which are more and more close to the invariant curve with rotation number ω (3) such orbits lie on analytical curves which tend uniformly to the invariant curve.

  5. A tunable acoustic metamaterial with double-negativity driven by electromagnets

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Xue, Cheng; Fan, Li; Zhang, Shu-Yi; Li, Xiao-Juan; Zhang, Hui; Ding, Jin

    2016-07-01

    With the advance of the research on acoustic metamaterials, the limits of passive metamaterials have been observed, which prompts the studies concerning actively tunable metamaterials with adjustable characteristic frequency bands. In this work, we present a tunable acoustic metamaterial with double-negativity composed of periodical membranes and side holes, in which the double-negativity pass band can be controlled by an external direct-current voltage. The tension and stiffness of the periodically arranged membranes are actively controlled by electromagnets producing additional stresses, and thus, the transmission and phase velocity of the metamaterial can be adjusted by the driving voltage of the electromagnets. It is demonstrated that a tiny direct-current voltage of 6V can arise a shift of double-negativity pass band by 40% bandwidth, which exhibits that it is an easily controlled and highly tunable acoustic metamaterial, and furthermore, the metamaterial marginally causes electromagnetic interference to the surroundings.

  6. A tunable acoustic metamaterial with double-negativity driven by electromagnets.

    PubMed

    Chen, Zhe; Xue, Cheng; Fan, Li; Zhang, Shu-Yi; Li, Xiao-Juan; Zhang, Hui; Ding, Jin

    2016-07-22

    With the advance of the research on acoustic metamaterials, the limits of passive metamaterials have been observed, which prompts the studies concerning actively tunable metamaterials with adjustable characteristic frequency bands. In this work, we present a tunable acoustic metamaterial with double-negativity composed of periodical membranes and side holes, in which the double-negativity pass band can be controlled by an external direct-current voltage. The tension and stiffness of the periodically arranged membranes are actively controlled by electromagnets producing additional stresses, and thus, the transmission and phase velocity of the metamaterial can be adjusted by the driving voltage of the electromagnets. It is demonstrated that a tiny direct-current voltage of 6V can arise a shift of double-negativity pass band by 40% bandwidth, which exhibits that it is an easily controlled and highly tunable acoustic metamaterial, and furthermore, the metamaterial marginally causes electromagnetic interference to the surroundings.

  7. A tunable acoustic metamaterial with double-negativity driven by electromagnets

    PubMed Central

    Chen, Zhe; Xue, Cheng; Fan, Li; Zhang, Shu-yi; Li, Xiao-juan; Zhang, Hui; Ding, Jin

    2016-01-01

    With the advance of the research on acoustic metamaterials, the limits of passive metamaterials have been observed, which prompts the studies concerning actively tunable metamaterials with adjustable characteristic frequency bands. In this work, we present a tunable acoustic metamaterial with double-negativity composed of periodical membranes and side holes, in which the double-negativity pass band can be controlled by an external direct-current voltage. The tension and stiffness of the periodically arranged membranes are actively controlled by electromagnets producing additional stresses, and thus, the transmission and phase velocity of the metamaterial can be adjusted by the driving voltage of the electromagnets. It is demonstrated that a tiny direct-current voltage of 6V can arise a shift of double-negativity pass band by 40% bandwidth, which exhibits that it is an easily controlled and highly tunable acoustic metamaterial, and furthermore, the metamaterial marginally causes electromagnetic interference to the surroundings. PMID:27443196

  8. A DEEPLY ECLIPSING DETACHED DOUBLE HELIUM WHITE DWARF BINARY

    SciTech Connect

    Parsons, S. G.; Marsh, T. R.; Gaensicke, B. T.; Drake, A. J.; Koester, D.

    2011-07-10

    Using Liverpool Telescope+RISE photometry we identify the 2.78 hr period binary star CSS 41177 as a detached eclipsing double white dwarf binary with a 21,100 K primary star and a 10,500 K secondary star. This makes CSS 41177 only the second known eclipsing double white dwarf binary after NLTT 11748. The 2 minute long primary eclipse is 40% deep and the secondary eclipse 10% deep. From Gemini+GMOS spectroscopy, we measure the radial velocities of both components of the binary from the H{alpha} absorption line cores. These measurements, combined with the light curve information, yield white dwarf masses of M{sub 1} = 0.283 {+-} 0.064 M{sub sun} and M{sub 2} = 0.274 {+-} 0.034 M{sub sun}, making them both helium core white dwarfs. As an eclipsing, double-lined spectroscopic binary, CSS 41177 is ideally suited to measuring precise, model-independent masses and radii. The two white dwarfs will merge in roughly 1.1 Gyr to form a single sdB star.

  9. The Stability of Periodic Orbits.

    DTIC Science & Technology

    1981-01-21

    I AOB a7 PRIlNCETON UNIV NJ JOSEPH HENRY LABS OF PHYSICS FD 7/S THE STABILITY OF PERIODIC ORBITS. (U) JAN 81 L SNEDOOM N00014-77-C-0711 UNCLASSIFIE-D...NL I - The Stability of Periodic Orbits Leigh Sneddon* Joseph Henry Laboratories of Physics Princeton University Princeton, New Jersey 08544 ABSTRACT...eigenvalue of the Poincare map passes out through the unit circle at -1 : see Appendix 1) 9,10 are observed and are referred to as subharmonic or period

  10. Analysis of the Petersen Diagram of Double Mode High Amplitude delta Scuti Stars

    NASA Astrophysics Data System (ADS)

    Furgoni, R.

    2016-06-01

    I created the Petersen diagram relative to all the Double Mode High Amplitude ? Scuti stars listed in the AAVSO's International Variable Star Index (Watson et al. 2007-2015) up to date December 29, 2015. For the first time I noticed that the ratio between the two periods P1/P0 seems in evident linear relation with the duration of the period P0, a finding never explicitly described in literature regarding this topic.

  11. Controlling chaos in the Bose-Einstein condensate system of a double lattice

    SciTech Connect

    Wang Zhixia Ni Zhengguo; Cong Fuzhong; Liu Xueshen; Chen Lei

    2011-02-15

    We study the chaotic dynamics in the Bose-Einstein condensate (BEC) system of a double lattice. Chaotic space-time evolution is investigated for the particle number density in a BEC. By changing of the s-wave scattering length with a Feshbach resonance, the chaotic behavior can be well controlled to enter into periodicity. Numerical calculation shows that there is periodic orbit according to the s-wave scattering length only if the maximal Lyapunov exponent of the system is negative.

  12. Analysis of a Leslie-Gower-type prey-predator model with periodic impulsive perturbations

    NASA Astrophysics Data System (ADS)

    Chen, Yiping; Liu, Zhijun; Haque, Mainul

    2009-08-01

    A modified Leslie-Gower-type prey-predator model with periodic impulsive perturbations is proposed and investigated. It is proved that there exists an asymptotically stable prey-free periodic solution when the impulsive period is less than some critical value. Otherwise, the above system can be permanent. And then the numerical simulations are carried out to study the effects of the impulsive varying parameters of the system. The results of simulations show that the model we consider, under the effects of impulsive perturbations for biologically feasible parametric values, has more complex dynamics including cycle, period adding, 3 T -period oscillation, chaos, period-doubling bifurcation, period-halving bifurcation, period windows, symmetry-breaking pitchfork bifurcation, and non-unique dynamics, meaning that several attractors coexist.

  13. An interesting prenatal diagnosis: double aneuploidy.

    PubMed

    Aydin, Cetin; Eris, Serenat; Yalcin, Yakup; Sen Selim, Halime

    2013-01-01

    Double aneuploidy, the existence of two chromosomal abnormalities in the same individual, is a rare condition. Early diagnosis of this condition is important to offer termination of pregnancy in genetic counselling. Cytogenetic analysis with amniocentesis and ultrasound examination is valuable for diagnosis of double aneuploidy. In this report we present a case with the karyotype of 48XXY+21 diagnosed prenatally.

  14. Double Prosecution of the State University Student

    ERIC Educational Resources Information Center

    Kelly, Thomas E., Jr.

    1974-01-01

    Explores whether the state university student confronted with double prosecution (university disciplinary proceedings and state or municipal criminal proceedings) has any constitutional basis for claiming the applicability of double jeopardy protection of the Fifth Amendment as a bar to a second prosecution. Concludes that the issue is not…

  15. The Sexual Double Standard: How Prevalent Today?

    ERIC Educational Resources Information Center

    Sack, Alan R.; And Others

    1981-01-01

    Studied the sexual double standard among university students. Females showed a stronger association between premarital intercourse and affection and perceived less approval from five reference groups for their sexual behavior than did males. Results indicate the sexual double standard is still evident among the present group of college students.…

  16. Intrateam Communication and Performance in Doubles Tennis

    ERIC Educational Resources Information Center

    Lausic, Domagoj; Tennebaum, Gershon; Eccles, David; Jeong, Allan; Johnson, Tristan

    2009-01-01

    Verbal and nonverbal communication is a critical mediator of performance in team sports and yet there is little extant research in sports that involves direct measures of communication. Our study explored communication within NCAA Division I female tennis doubles teams. Video and audio recordings of players during doubles tennis matches captured…

  17. Electric fields and double layers in plasmas

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra; Thiemann, H.; Schunk, R. W.

    1987-01-01

    Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamical features of the double layers are discussed. These features, as seen in simulations, laboratory experiments, and theory, indicate that double layers and the currents through them undergo slow oscillations which are determined by the ion transit time across an effective length of the system in which double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations were considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields and double layers in an expanding plasma is discussed.

  18. Electric fields and double layers in plasmas

    NASA Astrophysics Data System (ADS)

    Singh, Nagendra; Thiemann, H.; Schunk, R. W.

    1987-05-01

    Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamical features of the double layers are discussed. These features, as seen in simulations, laboratory experiments, and theory, indicate that double layers and the currents through them undergo slow oscillations which are determined by the ion transit time across an effective length of the system in which double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations were considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields and double layers in an expanding plasma is discussed.

  19. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, W.C.

    1988-10-11

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached. 8 figs.

  20. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, William C.

    1988-01-01

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached.

  1. The Doubling Moment: Resurrecting Edgar Allan Poe

    ERIC Educational Resources Information Center

    Minnick, J. Bradley; Mergil, Fernando

    2008-01-01

    This article expands upon Jeffrey Wilhelm's and Brian Edmiston's (1998) concept of a doubling of viewpoints by encouraging middle level students to use dramatization to take on multiple perspectives, to pose interpretive questions, and to enhance critical inquiry from inside and outside of texts. The doubling moment is both the activation of…

  2. Mapping the double-slit diffraction pattern

    NASA Astrophysics Data System (ADS)

    Selvaggi, Richard; Rogers, Charles; Richardson, Clay

    2010-10-01

    A red laser, movable double-slit, movable micrometer mounted single-slit light block, and CCD were utilized to map out the single and double-slit diffraction patterns between 0 and 30 millimeters. The three dimensional mapping results demonstrate that the double-slit troughs similarly redirect the electromagnetic energy and light particles. The measured alternating path of the electromagnetic energy and light particles in the double-slit diffraction pattern is different than the theoretic path of light waves defined by destructive interference and indicates that theoretical light waves do not always have electromagnetic energy. George Monk's 1937 and Richard Feynman's 1964 finding of conservation of electromagnetic energy in the double-slit light experiment present the following questions: 1) What are the mass-less and energy-less destructive interference light waves found in the double-slit troughs? 2) What force is applied to and what energy is consumed by the work of redistributing the electromagnetic energy and light particles in the double-slit diffraction pattern? 3) Is this unknown force and unknown energy the result of dark matter found in the double-slit troughs?

  3. Perspective: Double Jeopardy--Another Look.

    ERIC Educational Resources Information Center

    Bolduan, Linda M.; Dailey, Dianne K.

    1997-01-01

    Explores how a defendant can face a civil action and criminal prosecution for the same act without violating the principle of double jeopardy. For instance, burning down a house can engender criminal prosecution charges and a civil suit from the insurance company. Double jeopardy only applies to criminal actions. (MJP)

  4. Electron temperature differences and double layers

    NASA Technical Reports Server (NTRS)

    Chan, C.; Hershkowitz, N.; Lonngren, K. E.

    1983-01-01

    Electron temperature differences across plasma double layers are studied experimentally. It is shown that the temperature differences across a double layer can be varied and are not a result of thermalization of the bump-on-tail distribution. The implications of these results for electron thermal energy transport in laser-pellet and tandem-mirror experiments are also discussed.

  5. Femtosecond laser-induced periodic surface structures on silica

    SciTech Connect

    Hoehm, S.; Rosenfeld, A.; Krueger, J.; Bonse, J.

    2012-07-01

    The formation of laser-induced periodic surface structures (LIPSS) on two different silica polymorphs (single-crystalline synthetic quartz and commercial fused silica glass) upon irradiation in air with multiple linearly polarized single- and double-fs-laser pulse sequences ({tau} = 150 fs pulse duration, {lambda} = 800 nm center wavelength, temporal pulse separation {Delta}t < 40 ps) is studied experimentally and theoretically. Two distinct types of fs-LIPSS [so-called low-spatial-frequency LIPSS (LSFL) and high-spatial-frequency LIPSS (HSFL)] with different spatial periods and orientations were identified. Their appearance was characterized with respect to the experimental parameters peak laser fluence and number of laser pulses per spot. Additionally, the 'dynamics' of the LIPSS formation was addressed in complementary double-fs-pulse experiments with varying delays, revealing a characteristic change of the LSFL periods. The experimental results are interpreted on the basis of a Sipe-Drude model considering the carrier dependence of the optical properties of fs-laser excited silica. This new approach provides an explanation of the LSFL orientation parallel to the laser beam polarisation in silica - as opposed to the behaviour of most other materials.

  6. Chaos in Periodic Discrete Systems

    NASA Astrophysics Data System (ADS)

    Shi, Yuming; Zhang, Lijuan; Yu, Panpan; Huang, Qiuling

    This paper focuses on chaos in periodic discrete systems, whose state space may vary with time. Some close relationships between some chaotic dynamical behaviors of a periodic discrete system and its autonomous induced system are given. Based on these relationships, several criteria of chaos are established and some sufficient conditions for no chaos are given for periodic discrete systems. Further, it is shown that a finite-dimensional linear periodic discrete system is not chaotic in the sense of Li-Yorke or Wiggins. In particular, an interesting problem of whether nonchaotic rules may generate a chaotic system is studied, with some examples provided, one of which surprisingly shows that a composition of globally asymptotically stable maps can be chaotic. In addition, some properties of sign pattern matrices of non-negative square matrices are given for convenience of the study.

  7. Autism: a "critical period" disorder?

    PubMed

    LeBlanc, Jocelyn J; Fagiolini, Michela

    2011-01-01

    Cortical circuits in the brain are refined by experience during critical periods early in postnatal life. Critical periods are regulated by the balance of excitatory and inhibitory (E/I) neurotransmission in the brain during development. There is now increasing evidence of E/I imbalance in autism, a complex genetic neurodevelopmental disorder diagnosed by abnormal socialization, impaired communication, and repetitive behaviors or restricted interests. The underlying cause is still largely unknown and there is no fully effective treatment or cure. We propose that alteration of the expression and/or timing of critical period circuit refinement in primary sensory brain areas may significantly contribute to autistic phenotypes, including cognitive and behavioral impairments. Dissection of the cellular and molecular mechanisms governing well-established critical periods represents a powerful tool to identify new potential therapeutic targets to restore normal plasticity and function in affected neuronal circuits.

  8. Theoretical modeling of the dynamics of a semiconductor laser subject to double-reflector optical feedback

    NASA Astrophysics Data System (ADS)

    Bakry, A.; Abdulrhmann, S.; Ahmed, M.

    2016-06-01

    We theoretically model the dynamics of semiconductor lasers subject to the double-reflector feedback. The proposed model is a new modification of the time-delay rate equations of semiconductor lasers under the optical feedback to account for this type of the double-reflector feedback. We examine the influence of adding the second reflector to dynamical states induced by the single-reflector feedback: periodic oscillations, period doubling, and chaos. Regimes of both short and long external cavities are considered. The present analyses are done using the bifurcation diagram, temporal trajectory, phase portrait, and fast Fourier transform of the laser intensity. We show that adding the second reflector attracts the periodic and perioddoubling oscillations, and chaos induced by the first reflector to a route-to-continuous-wave operation. During this operation, the periodic-oscillation frequency increases with strengthening the optical feedback. We show that the chaos induced by the double-reflector feedback is more irregular than that induced by the single-reflector feedback. The power spectrum of this chaos state does not reflect information on the geometry of the optical system, which then has potential for use in chaotic (secure) optical data encryption.

  9. Neutrinoless double beta decay with Xe-136 in BOREXINO and the BOREXINO Counting Test Facility

    NASA Astrophysics Data System (ADS)

    Caccianiga, B.; Giammarchi, M. G.

    2000-08-01

    This article discusses the methods and sensitivity for a double beta decay experiment based on the Xe-136 candidate for BOREXINO or the BOREXINO Counting Test Facility. Different background assumptions and experimental configurations are studied, assuming a data obtaining period of one year. The related experimental problems are discussed, and summary tables containing the sensitivity estimates for the various configurations are presented.

  10. Double-blind trial of thiothixene and chlorpromazine in acute schizophrenia.

    PubMed

    Rickels, K; Byrdy, H; Valentine, J; Postel, W; Norstad, N; Downing, R

    1978-01-01

    In a double-blind trial of chlorpromazine and thiothixene conducted with 79 acutely ill, newly hospitalized schizophrenic patients, chlorpromazine and thiothixene were shown to be equally effective in producing meaningful symptomatic improvment over an average period of approximately 3 weeks, as measured by Global Assessments (CGI), BPRS, and NOSIE.

  11. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, Hannes

    1986-01-01

    A simple circuit is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from earth. Double layers in space should be classified as a new type of celestial object. It is suggested that X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). The way the most used textbooks in astrophysics treat concepts like double layers, critical velocity, pinch effects and circuits was studied. It is found that students using these textbooks remain essentially ignorant of even the existence of these, although some of the phenomena were discovered 50 yr ago.

  12. Reliability Estimation for Double Containment Piping

    SciTech Connect

    L. Cadwallader; T. Pinna

    2012-08-01

    Double walled or double containment piping is considered for use in the ITER international project and other next-generation fusion device designs to provide an extra barrier for tritium gas and other radioactive materials. The extra barrier improves confinement of these materials and enhances safety of the facility. This paper describes some of the design challenges in designing double containment piping systems. There is also a brief review of a few operating experiences of double walled piping used with hazardous chemicals in different industries. This paper recommends approaches for the reliability analyst to use to quantify leakage from a double containment piping system in conceptual and more advanced designs. The paper also cites quantitative data that can be used to support such reliability analyses.

  13. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, H.

    1986-01-01

    A simple circuit is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object. It is suggested that X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). The way the most used textbooks in astrophysics treat concepts like double layers, critical velocity, pinch effects and circuits was studied. It is found that students using these textbooks remain essentially ignorant of even the existence of these, although some of the phenomena were discovered 50 yr ago.

  14. Pumped double quantum dot with spin-orbit coupling.

    PubMed

    Khomitsky, Denis; Sherman, Eugene

    2011-03-11

    We study driven by an external electric field quantum orbital and spin dynamics of electron in a one-dimensional double quantum dot with spin-orbit coupling. Two types of external perturbation are considered: a periodic field at the Zeeman frequency and a single half-period pulse. Spin-orbit coupling leads to a nontrivial evolution in the spin and orbital channels and to a strongly spin- dependent probability density distribution. Both the interdot tunneling and the driven motion contribute into the spin evolution. These results can be important for the design of the spin manipulation schemes in semiconductor nanostructures.PACS numbers: 73.63.Kv,72.25.Dc,72.25.Pn.

  15. New massive bigravity cosmologies with double matter coupling

    SciTech Connect

    Lagos, Macarena; Noller, Johannes E-mail: noller@physics.ox.ac.uk

    2016-01-01

    We study a previously largely unexplored branch of homogeneous and isotropic background solutions in ghost-free massive bigravity with consistent double matter coupling. For a certain family of parameters we find 'self-inflated' FLRW cosmologies, i.e. solutions with an accelerated early-time period during the radiation-dominated era. In addition, these solutions also display an accelerated late-time period closely mimicking GR with a cosmological constant. Interestingly, within this family, the particular case of β{sub 1}=β{sub 3}=0 gives bouncing cosmologies, where there is an infinite contracting past, a non-zero minimum value of the scale factor at the bounce, and an infinite expanding future.

  16. Double-disc gate valve

    DOEpatents

    Wheatley, Seth J.

    1979-01-01

    This invention relates to an improvement in a conventional double-disc gate valve having a vertically movable gate assembly including a wedge, spreaders slidably engaged therewtih, a valve disc carried by the spreaders. When the gate assembly is lowered to a selected point in the valve casing, the valve discs are moved transversely outward to close inlet and outlet ports in the casing. The valve includes hold-down means for guiding the disc-and-spreader assemblies as they are moved transversely outward and inward. If such valves are operated at relatively high differential pressures, they sometimes jam during opening. Such jamming has been a problem for many years in gate valves used in gaseous diffusion plants for the separtion of uranium isotopes. The invention is based on the finding that the above-mentioned jamming results when the outlet disc tilts about its horizontal axis in a certain way during opening of the valve. In accordance with the invention, tilting of the outlet disc is maintained at a tolerable value by providing the disc with a rigid downwardly extending member and by providing the casing with a stop for limiting inward arcuate movement of the member to a preselected value during opening of the valve.

  17. DOUBLE-LINED SPECTROSCOPIC BINARY STARS IN THE RAVE SURVEY

    SciTech Connect

    Matijevic, G.; Zwitter, T.; Munari, U.; Siviero, A.; Bienayme, O.; Siebert, A.; Binney, J.; Bland-Hawthorn, J.; Boeche, C.; Steinmetz, M.; Campbell, R.; Freeman, K. C.; Gibson, B.; Gilmore, G.; Grebel, E. K.; Helmi, A.; Navarro, J. F.; Parker, Q. A.; Seabroke, G. M.; Watson, F. G.

    2010-07-15

    We devise a new method for the detection of double-lined binary stars in a sample of the Radial Velocity Experiment (RAVE) survey spectra. The method is both tested against extensive simulations based on synthetic spectra and compared to direct visual inspection of all RAVE spectra. It is based on the properties and shape of the cross-correlation function, and is able to recover {approx}80% of all binaries with an orbital period of order 1 day. Systems with periods up to 1 yr are still within the detection reach. We have applied the method to 25,850 spectra of the RAVE second data release and found 123 double-lined binary candidates, only eight of which are already marked as binaries in the SIMBAD database. Among the candidates, there are seven that show spectral features consistent with the RS CVn type (solar type with active chromosphere) and seven that might be of W UMa type (over-contact binaries). One star, HD 101167, seems to be a triple system composed of three nearly identical G-type dwarfs. The tested classification method could also be applicable to the data of the upcoming Gaia mission.

  18. Periodic solar wind density structures

    NASA Astrophysics Data System (ADS)

    Viall, Nicholeen Mary

    2010-01-01

    This dissertation addresses a specific aspect of the Sun-Earth connection: we show that coronal activity creates periodic density structures in the solar wind which convect radially outward and interact with Earth's magnetosphere. First, we analyze 11 years (1995-2005) of in situ solar wind density observations from the Wind spacecraft and find that periodic density structures occur at particular sets of radial length-scales more often than others. This indicates that these density fluctuations, which have radial length-scales of hundreds of megameters, cannot be attributed entirely to turbulence. Next, we analyze their effect on Earth's magnetosphere. Though these structures are not waves in the solar wind rest frame, they appear at discrete frequencies in Earth's reference frame. They compress the magnetosphere as they convect past, driving global magnetospheric oscillations at the same discrete frequencies as the periodic density structures. Last, we investigate source regions and mechanisms of the periodic solar wind density structures. We analyze the alpha particle to proton abundance ratio during events of periodic density structures. In many events, the proton and alpha density fluctuations are anti- correlated, which strongly argues for either temporally or spatially varying coronal source plasma. We examine white light images of the solar wind taken with SECCHI HI1 on the STEREO spacecraft and find periodic density structures as near to the Sun as 15 solar radii. The smallest resolvable periodic structures that we identify are of comparable length to those found at 1 AU, providing further evidence that at least some periodic density structures are generated in the solar corona as the solar wind is formed. Guided by the properties observed during previous studies and the characteristics established through the work presented here, we examine possible candidate mechanisms in the solar corona that can form periodic density structures. We conclude that

  19. Shortest recurrence periods of novae

    SciTech Connect

    Kato, Mariko; Saio, Hideyuki; Hachisu, Izumi; Nomoto, Ken'ichi

    2014-10-01

    Stimulated by the recent discovery of the 1 yr recurrence period nova M31N 2008-12a, we examined the shortest recurrence periods of hydrogen shell flashes on mass-accreting white dwarfs (WDs). We discuss the mechanism that yields a finite minimum recurrence period for a given WD mass. Calculating the unstable flashes for various WD masses and mass accretion rates, we identified a shortest recurrence period of about two months for a non-rotating 1.38 M {sub ☉} WD with a mass accretion rate of 3.6 × 10{sup –7} M {sub ☉} yr{sup –1}. A 1 yr recurrence period is realized for very massive (≳ 1.3 M {sub ☉}) WDs with very high accretion rates (≳ 1.5 × 10{sup –7} M {sub ☉} yr{sup –1}). We revised our stability limit of hydrogen shell burning, which will be useful for binary evolution calculations toward Type Ia supernovae.

  20. Clinical Significance of “Double-hit” and “Double-protein” expression in Primary Gastric B-cell Lymphomas

    PubMed Central

    He, Miaoxia; Chen, Keting; Li, Suhong; Zhang, Shimin; Zheng, Jianming; Hu, Xiaoxia; Gao, Lei; Chen, Jie; Song, Xianmin; Zhang, Weiping; Wang, Jianmin; Yang, Jianmin

    2016-01-01

    BACKGROUND AND AIMS: Primary gastric B-cell lymphoma is the second most common malignancy of the stomach. There are many controversial issues about its diagnosis, treatment and clinical management. “Double-hit” and “double-protein” involving gene rearrangement and protein expression of c-Myc and bcl2/bcl6 are the most used terms to describe DLBCL poor prognostic factors in recent years. However, very little is known about the role of these prognostic factors in primary gastric B-cell lymphomas. This study aims to obtain a molecular pathology prognostic model of gastric B-cell lymphoma for clinical stratified management by evaluating how the “double-hit” and “double-protein” in tumor cells as well as microenvironmental reaction of tumor stromal tissue affect clinical outcome in primary gastric B-cell lymphomas. METHODS: Data and tissues of 188 cases diagnosed with gastric B-cell lymphomas were used in this study. Tumor tissue microarray (TMA) of formalin fixed and paraffin embedded (FFPE) tissues was constructed for fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) analysis with a serial of biomarkers containing MYC, BCL2, BCL6, CD31, SPARC, CD10, MUM1 and Ki-67. Modeled period analysis was used to estimate 3-year and 5-year overall survival (OS) and disease-free survival (DFS) distributions. RESULTS: There was no definite “double-hit” case though the gene rearrangement of c-Myc (5.9%), bcl2 (0.1%) and bcl6 (7.4%) was found in gastric B-cell lymphomas. The gene amplification or copy gains of c-Myc (10.1%), bcl-2 (17.0%) and bcl-6 (0.9%) were present in these lymphomas. There were 12 cases of the lymphomas with the “double-protein” expression of MYC and BCL2/BCL6. All patients with “double-protein” gastric B-cell lymphomas had poor outcome compared with those without. More importantly, “MYC-BCL2-BCL6” negative group of gastric B-cell lymphoma patients had favorable clinical outcome regardless clinical stage

  1. The double-dark portal

    NASA Astrophysics Data System (ADS)

    Curtin, David; Tsai, Yuhsin

    2014-11-01

    In most models of the dark sector, dark matter is charged under some new symmetry to make it stable. We explore the possibility that not just dark matter, but also the force carrier connecting it to the visible sector is charged under this symmetry. This dark mediator then acts as a Double-Dark Portal. We realize this setup in the dark mediator Dark matter model (dmDM), featuring a fermionic DM candidate χ with Yukawa couplings to light scalars ϕ i . The scalars couple to SM quarks via the operator . This can lead to large direct detection signals via the 2 → 3 process χ N → χ N ϕ if one of the scalars has mass ≲ 10 keV. For dark matter Yukawa couplings y χ ˜ 10-3 -10-2, dmDM features a thermal relic dark matter candidate while also implementing the SIDM scenario for ameliorating inconsistencies between dwarf galaxy simulations and observations. We undertake the first systematic survey of constraints on light scalars coupled to the SM via the above operator. The strongest constraints are derived from a detailed examination of the light mediator's effects on stellar astrophysics. LHC experiments and cosmological considerations also yield important bounds. Observations of neutron star cooling exclude the minimal model with one dark mediator, but a scenario with two dark mediators remains viable and can give strong direct detection signals. We explore the direct detection consequences of this scenario and find that a heavy dmDM candidate fakes different WIMPs at different experiments. Large regions of dmDM parameter space are accessible above the irreducible neutrino background.

  2. Bragg interactions in periodic media

    NASA Technical Reports Server (NTRS)

    Jaggard, D. L.

    1976-01-01

    The interaction of electromagnetic waves of wavelength lambda with periodic structures of spatial period lambda are studied. The emphasis of the work is on Bragg interactions where lambda approximately equal to 2 lambda/N and the Bragg order N takes on the values 1, 2,.... An extended coupled waves (ECW) theory is developed for the case N greater or equal to 2 and the results of the theory are found to compare favorably with the exact results of Floquet theory. Numerous numerical results are displayed as Brillouin diagrams for the first few Bragg orders. Moreover, explicit expressions for coupling coefficients, bandgap shifts and bandgap widths are derived for singly periodic media. Particular note is taken of phase speeding effects.

  3. Geologic periodicities and the Galaxy

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Stothers, Richard B.

    1986-01-01

    New geologic and astronomical developments are reviewed that have recently led to the proposal of various Galactic theories to explain the temporal pattern of impact craters on earth. Linear and harmonic time series analyses have revealed that two dominant periodicities about equal to 33 + or - 3 Myr and 260 + or - 25 Myr underlie the geologic record of terrestrial impact cratering and global tectonic phenomena. It is argued that purely terrestrial mechanisms cannot account for the cratering cycles as being preservational artifacts; cratering rather appears to influence tectonism, possibly through perturbations of mantle convection. Galactic models proposed to explain the two long-term periodicities are reviewed critically. The most likely explanation for the 33 Myr cycle involves the comparatively stable half period of vertical oscillation of the solar system about the Galactic plane. The 260 Myr cycle may be related to rare encounters with Galactic spiral arms during the revolution of the solar system around the Galactic center.

  4. The Longest Period Cepheids, a bridge to the Hubble Constant

    NASA Astrophysics Data System (ADS)

    Riess, Adam

    2014-10-01

    An independent measurement of the Hubble Constant with 1-2% precision offers enormous leverage for resolving outstanding cosmological investigations including the the precise geometry of space, the properties of the elusive neutrinos, and the nature of dark energy. It would contribute the equivalent of nearly doubling the size of other near term cosmological surveys like DES, BOSS and Pan-STARRS. We are building a new distance ladder to double the current precision of the Hubble constant to <2% by attacking the largest unaddressed obstacle to its determination, the lack of parallaxes of long period Milky Way Cepheids. We have developed a new technique to measure relative astrometry of bright stars and their parallaxes with WFC3 using spatial scanning, improving upon the previous best relative astrometry with the HST FGS by an order of magnitude to reach distances of 1-4 kiloparsecs. A new scanning mode, serpentine spatial scan, is available in Cycle 21. It allows us to avoid saturating observations of Milky Way Cepheids with P>25 days which would otherwise be too bright. Measuring the luminosities of these Cepheids is vital to calibrating their analogues visible to HST in distant galaxies which host type Ia supernovae. With Planck CMB data already in hand, this new measurement of the Hubble constant will more than double the precision of the dark energy equation of state, may reveal a new species of neutrino, and would further HST's legacy in the measurement of the Hubble constant, a task for which it was launched.

  5. The Longest Period Cepheids, a bridge to the Hubble Constant

    NASA Astrophysics Data System (ADS)

    Riess, Adam

    2013-10-01

    An independent measurement of the Hubble Constant with 1-2% precision offers enormous leverage for resolving outstanding cosmological investigations including the the precise geometry of space, the properties of the elusive neutrinos, and the nature of dark energy. It would contribute the equivalent of nearly doubling the size of other near term cosmological surveys like DES, BOSS and Pan-STARRS. We are building a new distance ladder to double the current precision of the Hubble constant to <2% by attacking the largest unaddressed obstacle to its determination, the lack of parallaxes of long period Milky Way Cepheids. We have developed a new technique to measure relative astrometry of bright stars and their parallaxes with WFC3 using spatial scanning, improving upon the previous best relative astrometry with the HST FGS by an order of magnitude to reach distances of 1-4 kiloparsecs. A new scanning mode, serpentine spatial scan, is available in Cycle 21. It allows us to avoid saturating observations of Milky Way Cepheids with P>25 days which would otherwise be too bright. Measuring the luminosities of these Cepheids is vital to calibrating their analogues visible to HST in distant galaxies which host type Ia supernovae. With Planck CMB data already in hand, this new measurement of the Hubble constant will more than double the precision of the dark energy equation of state, may reveal a new species of neutrino, and would further HST's legacy in the measurement of the Hubble constant, a task for which it was launched.

  6. Double-reed exhaust valve engine

    DOEpatents

    Bennett, Charles L.

    2015-06-30

    An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a double reed outlet valve for controlling the flow of low-pressure working fluid out of the engine. The double reed provides a stronger force resisting closure of the outlet valve than the force tending to open the outlet valve. The double reed valve enables engine operation at relatively higher torque and lower efficiency at low speed, with lower torque, but higher efficiency at high speed.

  7. Vacuum leak detection for double bottom tanks

    SciTech Connect

    Hagen, T.; Rials, R.

    1995-12-31

    Double bottom tanks offer strong leak detection advantages. By incorporating the use of vacuum detection between the two bottoms, the tank bottoms can be verified leak free after construction and during tank use. Utilizing vacuum leak detection requires special considerations. In 1992 a tank construction company built 10 tanks for an oil company in Ponca City, Oklahoma. Each of these tanks were built with a double bottom. This paper provides insight into the planning, construction and testing of this type of double bottom design.

  8. Earthquakes with non--double-couple mechanisms.

    PubMed

    Frohlich, C

    1994-05-06

    Seismological observations confirm that the pattern of seismic waves from some earthquakes cannot be produced by slip along a planar fault surface. More than one physical mechanism is required to explain the observed varieties of these non-double-couple earthquakes. The simplest explanation is that some earthquakes are complex, with stress released on two or more suitably oriented, nonparallel fault surfaces. However, some shallow earthquakes in volcanic and geothermal areas require other explanations. Current research focuses on whether fault complexity explains most observed non-double-couple earthquakes and to what extent ordinary earthquakes have non-double-couple components.

  9. Periodicity in marine extinction events

    NASA Technical Reports Server (NTRS)

    Sepkoski, J. John, Jr.; Raup, David M.

    1986-01-01

    The periodicity of extinction events is examined in detail. In particular, the temporal distribution of specific, identifiable extinction events is analyzed. The nature and limitations of the data base on the global fossil record is discussed in order to establish limits of resolution in statistical analyses. Peaks in extinction intensity which appear to differ significantly from background levels are considered, and new analyses of the temporal distribution of these peaks are presented. Finally, some possible causes of periodicity and of interdependence among extinction events over the last quarter billion years of earth history are examined.

  10. Sigmoid Volvulus Complicating Postpartum Period

    PubMed Central

    Blake, Erin; Gonzalez, Eduardo; Pieracci, Frederic

    2017-01-01

    Background. Sigmoid volvulus is a rare complication of pregnancy and the puerperium. Case. A 19-year-old patient, gravida 1 para 0 at 41 0/7 weeks of gestation, admitted for late-term induction of labor underwent an uncomplicated primary low transverse cesarean delivery for arrest of descent. Her postoperative period was complicated by sudden onset of abdominal pain and the ultimate diagnosis of sigmoid volvulus. Conclusion. Prompt surgical evaluation of an acute abdomen in the postpartum period is essential; delayed diagnosis and treatment can lead to significant maternal morbidity and mortality. PMID:28251004

  11. Storage controls on the generation of double peak hydrographs in a forested headwater catchment

    NASA Astrophysics Data System (ADS)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; Iffly, Jean François; Pfister, Laurent

    2016-12-01

    Double peak hydrographs are widespread phenomena but poorly understood mechanistically. In many cases, saturation-excess overland flow in the near-stream areas is assumed to control the initial peak, while the delayed peak is explained by subsurface flow in the soil or sediment cover or groundwater flow on fractured bedrock. Here we explore the mechanisms that control the generation of double peak hydrographs in a forested headwater catchment. We made use of the extensive high-resolution hydrometric time series collected in the catchment to estimate catchment storage and causal linkages. We found that double peak hydrographs occurred only after a certain amount of catchment storage was exceeded. The amount of this storage threshold was consistent over a 3-year period. The non-linear relationship between storage and discharge led to hysteretic relationships between both variables, and these hysteretic relationships were different for the different hydrograph types (single or double peak hydrographs). Discharge peaked before catchment storage during single peak hydrographs suggesting that single peaks were mainly generated by water quickly reaching the stream during precipitation pulses. It was catchment storage that peaked first during double peak hydrographs and consequently generated the delayed peak in the hydrograph. Our results also showed that double peak hydrographs were controlled in different proportions by contrasting landscape units (defined along a hillslope sequence). Hillslopes were connected to the stream at low discharge values, whereas the plateau dominated discharge generation when storage reached a certain threshold value.

  12. Propagation of Electromagnetic Waves in Two Dimensionally Periodic Media

    NASA Astrophysics Data System (ADS)

    Dong, Tian-Lin

    1985-12-01

    The propagation of electromagnetic waves in two dimensionally periodic structure is systematically investigated, to provide the basic theory for two dimensionally modulated dielectric waveguide. A canonical two dimensionally periodic medium of infinite extent, whose dielectic constant varies sinusoidally in two orthogonal directions, is first examined. The charact solutions are represented exactly by a double Fourier series which is known as the Floquet solution. The harmonic amplitudes of the Floquet solution are determined by a five-term recurrence relation in the vector form, properly taking into account the hybrid-mode nature of the propagation problem. The five-term recurrence relation is then treated by different approaches so that clear physical pictures and practical numerical methods can be obtained. The characteristic solutions for two dimensionally periodic medium are then applied to the boundary-value problem of multi-layer dielectric waveguides containing a finite layer of periodic medium. As an example, the guidance problems are analysed and the numerical analysis of the dispersion characteristics are then carried out. Besides the canonical medium as a model, more general two dimensionally periodic medium are also discussed.

  13. Mechanistic analysis of double-shell tank gas release

    SciTech Connect

    Allemann, R.T.; Antoniak, Z.I.; Friley, J.R.; Haines, C.E.; Liljegren, L.M.; Somasundaram, S.

    1991-12-01

    Pacific Northwest Laboratory (PNL) is studying possible mechanisms and fluid dynamics contributing to the periodic release of gases from the double-shell waste storage tanks at Hanford. This study is being conducted for Westinghouse Hanford Company (WHC), a contractor for the US Department of Energy (DOE). This interim report discusses the work done through November 1990. Safe management of the wastes at Hanford depends on an understanding of the chemical and physical mechanisms that take place in the waste tanks. An example of the need to understand these mechanisms is tank 101-SY. The waste in this tank is generating and periodically releasing potentially flammable gases into the tank vent system according to observations of the tank. How these gases are generated and become trapped, the causes of periodic release, and the mechanism of the release are not known in detail. In order to develop a safe mitigation strategy, possible physical mechanisms for the periodic release of flammable gases need to be understood.

  14. 76 FR 80312 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... of the Business Reply Mail cost model in periodic reporting of service performance measurement... initiate a rulemaking proceeding to address the current methodology used to develop the avoided cost.... SUMMARY: The Commission is establishing a docket to consider new measurement of Flats Sequencing...

  15. A Special Section. College Periodicals.

    ERIC Educational Resources Information Center

    Currents, 1988

    1988-01-01

    Special section includes "True to Format," an editor's guide to periodicals (Robin Goldman); "The Move to Magazine," focusing on format (Patricia Ann LaSalle); "The Fast-paced Alternative," about timely tabloids (Janis D. Gleason, Lynn Donham); and also about tabloids, "Why Don't We Have a Magazine?" (Marsha…

  16. 76 FR 20906 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-14

    ... a proposed change in certain analytical methods used in periodic reporting. This action responds to... an informal rulemaking proceeding to consider changes in the analytical methods approved for use in... Proceeding to Consider Proposed Changes in Analytic Principles (Proposal One), April 6, 2011...

  17. Quantifying periodicity in omics data

    PubMed Central

    Amariei, Cornelia; Tomita, Masaru; Murray, Douglas B.

    2014-01-01

    Oscillations play a significant role in biological systems, with many examples in the fast, ultradian, circadian, circalunar, and yearly time domains. However, determining periodicity in such data can be problematic. There are a number of computational methods to identify the periodic components in large datasets, such as signal-to-noise based Fourier decomposition, Fisher's g-test and autocorrelation. However, the available methods assume a sinusoidal model and do not attempt to quantify the waveform shape and the presence of multiple periodicities, which provide vital clues in determining the underlying dynamics. Here, we developed a Fourier based measure that generates a de-noised waveform from multiple significant frequencies. This waveform is then correlated with the raw data from the respiratory oscillation found in yeast, to provide oscillation statistics including waveform metrics and multi-periods. The method is compared and contrasted to commonly used statistics. Moreover, we show the utility of the program in the analysis of noisy datasets and other high-throughput analyses, such as metabolomics and flow cytometry, respectively. PMID:25364747

  18. Shell Games: Uncovering Periodic Properties.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1983-01-01

    Describes activities (demonstrations/experiments) used to introduce history of periodic properties--without electrons, orbitals, filling shells, or any conception of atoms beyond Dalton's model. Activities supplement first chapter in a currently available chemistry text. Indicates potential danger of experiments if proper safety precautions are…

  19. Fast excitation variable period wiggler

    SciTech Connect

    van Steenbergen, A.; Gallardo, J.; Romano, T.; Woodle, M.

    1991-01-01

    The design of an easily stackable, variable period length, fast excitation driven wiggler, making use of geometrically alternating substacks of Vanadium Permandur ferromagnetic laminations, interspaced with conductive, non magnetic, laminations which act as eddy current induced field reflectors,'' is discussed and experimental results obtained with short wiggler models are presented.

  20. Fast excitation variable period wiggler

    SciTech Connect

    van Steenbergen, A.; Gallardo, J.; Romano, T.; Woodle, M.

    1991-12-31

    The design of an easily stackable, variable period length, fast excitation driven wiggler, making use of geometrically alternating substacks of Vanadium Permandur ferromagnetic laminations, interspaced with conductive, non magnetic, laminations which act as eddy current induced ``field reflectors,`` is discussed and experimental results obtained with short wiggler models are presented.

  1. Stability of underwater periodic locomotion

    NASA Astrophysics Data System (ADS)

    Jing, Fangxu; Kanso, Eva

    2013-07-01

    Most aquatic vertebrates swim by lateral flapping of their bodies and caudal fins. While much effort has been devoted to understanding the flapping kinematics and its influence on the swimming efficiency, little is known about the stability (or lack of) of periodic swimming. It is believed that stability limits maneuverability and body designs/flapping motions that are adapted for stable swimming are not suitable for high maneuverability and vice versa. In this paper, we consider a simplified model of a planar elliptic body undergoing prescribed periodic heaving and pitching in potential flow. We show that periodic locomotion can be achieved due to the resulting hydrodynamic forces, and its value depends on several parameters including the aspect ratio of the body, the amplitudes and phases of the prescribed flapping.We obtain closedform solutions for the locomotion and efficiency for small flapping amplitudes, and numerical results for finite flapping amplitudes. This efficiency analysis results in optimal parameter values that are in agreement with values reported for some carangiform fish. We then study the stability of the (finite amplitude flapping) periodic locomotion using Floquet theory. We find that stability depends nonlinearly on all parameters. Interesting trends of switching between stable and unstable motions emerge and evolve as we continuously vary the parameter values. This suggests that, for live organisms that control their flapping motion, maneuverability and stability need not be thought of as disjoint properties, rather the organism may manipulate its motion in favor of one or the other depending on the task at hand.

  2. The Period of Salutary Neglect.

    ERIC Educational Resources Information Center

    Hyland, John T.; And Others

    1987-01-01

    Presents a lesson designed to teach students about the period of Salutary Neglect (100 years before the French and Indian Wars) and its effects on later historical events. Provides an advance organizer which puts students in a situation of salutary neglect and includes student and teacher resources on the Stamp Act, the Townshend Acts, and the…

  3. Optimal periodic control for spacecraft pointing and attitude determination

    NASA Technical Reports Server (NTRS)

    Pittelkau, Mark E.

    1993-01-01

    A new approach to autonomous magnetic roll/yaw control of polar-orbiting, nadir-pointing momentum bias spacecraft is considered as the baseline attitude control system for the next Tiros series. It is shown that the roll/yaw dynamics with magnetic control are periodically time varying. An optimal periodic control law is then developed. The control design features a state estimator that estimates attitude, attitude rate, and environmental torque disturbances from Earth sensor and sun sensor measurements; no gyros are needed. The state estimator doubles as a dynamic attitude determination and prediction function. In addition to improved performance, the optimal controller allows a much smaller momentum bias than would otherwise be necessary. Simulation results are given.

  4. High resolution heterodyne interferometer without detectable periodic nonlinearity.

    PubMed

    Joo, Ki-Nam; Ellis, Jonathan D; Buice, Eric S; Spronck, Jo W; Schmidt, Robert H Munnig

    2010-01-18

    A high resolution heterodyne laser interferometer without periodic nonlinearity for linear displacement measurements is described. It uses two spatially separated beams with an offset frequency and an interferometer configuration which has no mixed states to prevent polarization mixing. In this research, a simple interferometer configuration for both retroreflector and plane mirror targets which are both applicable to industrial applications was developed. Experimental results show there is no detectable periodic nonlinearity for both of the retro-reflector interferometer and plane mirror interferometer to the noise level of 20 pm. Additionally, the optical configuration has the benefit of doubling the measurement resolution when compared to its respective traditional counterparts. Because of non-symmetry in the plane mirror interferometer, a differential plane mirror interferometer to reduce the thermal error is also discussed.

  5. Hyperkalemic periodic paralysis associated with multiple sleep onset REM periods.

    PubMed

    Iranzo, A; Santamaria, J

    1999-12-15

    A 24-year-old man with sporadic hyperkalemic periodic paralysis (HPP) presented with moderate excessive daytime sleepiness and transitory episodes of weakness which occurred during and after sleep. Multiple sleep latency test (MSLT) demonstrated the presence of five sleep onset REM periods (SOREMPs) and a sleep latency of five minutes. Treatment with a diuretic which decreases serum potassium resolved all the clinical symtomps and a new MSLT showed the absence of SOREMPs and a sleep latency of 13.5 minutes. To our knowledge, the patient herein reported is the first case that associates sleep abnormalities and multiple SOREMPs with HPP. Furthermore, the present case suggests that SOREMPs may be explained by an increased extracellular potassium conductance related to HPP.

  6. A new hydrodynamic analysis of double layers

    NASA Technical Reports Server (NTRS)

    Hora, Heinrich

    1987-01-01

    A genuine two-fluid model of plasmas with collisions permits the calculation of dynamic (not necessarily static) electric fields and double layers inside of plasmas including oscillations and damping. For the first time a macroscopic model for coupling of electromagnetic and Langmuir waves was achieved with realistic damping. Starting points were laser-produced plasmas showing very high dynamic electric fields in nonlinear force-produced cavitous and inverted double layers in agreement with experiments. Applications for any inhomogeneous plasma as in laboratory or in astrophysical plasmas can then be followed up by a transparent hydrodynamic description. Results are the rotation of plasmas in magnetic fields and a new second harmonic resonance, explanation of the measured inverted double layers, explanation of the observed density-independent, second harmonics emission from laser-produced plasmas, and a laser acceleration scheme by the very high fields of the double layers.

  7. Inverse solutions for tilting orthogonal double prisms.

    PubMed

    Li, Anhu; Ding, Ye; Bian, Yongming; Liu, Liren

    2014-06-10

    An analytical reverse solution and actual examples are given to show how to direct a laser beam from a pair of orthogonal prisms to given targets in free space. Considering the influences of double-prism structural parameters, a lookup table method to seek the numerical reverse solution of each prism's tilting angle is also proposed for steering the double-prism orientation to track a target position located in the near field. Some case studies, as well as a specified elliptical target trajectory scanned by the cam-based driving double prisms, exhibit the significant application values of the theoretical derivation. The analytic reverse and numerical solutions can be generalized to investigate the synthesis of scanning patterns and the controlling strategy of double-prism tilting motion, the potentials of which can be explored to perform the orientation and position tracking functions in applications of precision engineering fields.

  8. A High Power Frequency Doubled Fiber Laser

    NASA Technical Reports Server (NTRS)

    Thompson, Rob; Tu, Meirong; Aveline, Dave; Lundblad, Nathan; Maleki, Lute

    2003-01-01

    This slide presentation reviews the power frequencies for the doubled fiber laser. It includes information on the 780 nm laser, second harmonic generation in one crystal, cascading crystals, the tenability of laser systems, laser cooling, and directions for future work.

  9. Improved double beam, vacuum far infrared spectrophotometer.

    PubMed

    Iwahashi, I; Matsumoto, K; Matsudaira, S; Minami, S; Yoshinaga, H

    1969-03-01

    A double beam far ir spectrophotometer was improved in order to give more convenience and higher performance. The instrument is evacuable and the sample chamber alone can also be purged with dry air to remove water vapor. Three photometric systems, i.e., conventional double beam, double beam double chopping, and single beam systems can be selected for versatile measurements. The use of an efficient transmission filter system, not involving deliquescent crystals, results in many operational advantages. Accordingly, high resolution can be obtained through the entire spectral region from 400 cm(-1) to 30 cm(-1) Moreover, 30-min scan over the entire spectral region is achieved by completely automatic operation with a refined control system.

  10. Frequency Doubling Broadband Light in Multiple Crystals

    SciTech Connect

    ALFORD,WILLIAM J.; SMITH,ARLEE V.

    2000-07-26

    The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth.

  11. Double Power: English Literacy and Indigenous Education.

    ERIC Educational Resources Information Center

    Wignell, Peter, Ed.

    The collection of essays on the relationship between English literacy and indigenous education, particularly in the Australian context, includes: "Double Power" (Mandawuy Yunupingu); "History, Cultural Diversity & English Language Teaching" (Martin Nakata); "Scaffolding Reading and Writing for Indigenous Children in…

  12. Dry Eyes and Glaucoma: Double Trouble

    MedlinePlus

    ... News About Us Donate In This Section Dry Eyes and Glaucoma: Double Trouble email Send this article ... disease bothers the patient more. What Causes Dry Eye Syndrome? Dry eye can be caused by many ...

  13. Over-under double-pass interferometer

    NASA Technical Reports Server (NTRS)

    Schindler, R. A. (Inventor)

    1977-01-01

    An over-under double pass interferometer in which the beamsplitter area and thickness can be reduced to conform only with optical flatness considerations was achieved by offsetting the optical center line of one cat's-eye retroreflector relative to the optical center line of the other in order that one split beam be folded into a plane distinct from the other folded split beam. The beamsplitter is made transparent in one area for a first folded beam to be passed to a mirror for doubling back and is made totally reflective in another area for the second folded beam to be reflected to a mirror for doubling back. The two beams thus doubled back are combined in the central, beamsplitting area of the beamsplitting and passed to a detector. This makes the beamsplitter insensitive to minimum thickness requirements and selection of material.

  14. Review of modern double beta decay experiments

    SciTech Connect

    Barabash, A. S.

    2015-10-28

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T{sub 1/2}(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino (〈m{sub ν}〉 < 0.46 eV) and a coupling constant of Majoron to neutrino (〈g{sub ee}〉 < 1.3 · 10{sup −5}) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to 〈m{sub ν}〉 at the level of ∼ 0.01-0.1 eV are discussed.

  15. Double Shell Tank (DST) Transfer Valving Specification

    SciTech Connect

    GRAVES, C.E.

    2001-01-17

    This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied during design of the Double-Shell Tank (DST) Transfer Valving Subsystem that supports the first phase of Waste Feed Delivery.

  16. The Double Scene of Televised AIDS Campaigns.

    ERIC Educational Resources Information Center

    Cummings, Kate

    1992-01-01

    Analyzes the double or mirrored scene of the Centers for Disease Control's AIDS education campaign and the responses to that campaign, basically, the dominant, heterosexual, televised discourses' defensive erasure of those semiotic objects that represent illicit and nonreproductive sex. (RS)

  17. Don't Double Up on Acetaminophen

    MedlinePlus

    ... Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer Updates Don't Double ... products. January 24, 2013 back to top Related Consumer Updates Have a Baby or Young Child With ...

  18. 12 CFR 390.285 - Audit period.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Audit period. 390.285 Section 390.285 Banks and... Associations § 390.285 Audit period. The audit period of a State savings association means the twelve month period (or other period in the case of a change in audit period) covered by the annual audit conducted...

  19. 12 CFR 161.6 - Audit period.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Audit period. 161.6 Section 161.6 Banks and... SAVINGS ASSOCIATIONS § 161.6 Audit period. The audit period of a savings association means the twelve month period (or other period in the case of a change in audit period) covered by the annual...

  20. 12 CFR 561.6 - Audit period.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Audit period. 561.6 Section 561.6 Banks and... SAVINGS ASSOCIATIONS § 561.6 Audit period. The audit period of a savings association means the twelve month period (or other period in the case of a change in audit period) covered by the annual...

  1. 12 CFR 390.285 - Audit period.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Audit period. 390.285 Section 390.285 Banks and... Associations § 390.285 Audit period. The audit period of a State savings association means the twelve month period (or other period in the case of a change in audit period) covered by the annual audit conducted...

  2. 7 CFR 1160.113 - Fiscal period.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Fiscal period. 1160.113 Section 1160.113 Agriculture... Definitions § 1160.113 Fiscal period. Fiscal period means the initial period of up to 30 months that this subpart is effective. Thereafter, the fiscal period shall be such annual period as the Board may...

  3. Crack Propagation in Double-Base Propellants

    DTIC Science & Technology

    1976-01-01

    propagation tests were conducted on a composite modified double- base ( CMDB ) propellant with the use of center-cracked strip biaxial specimens...double-base ( CMDB ) propellant. He performed a stress analysis of small, precracked, subscale STV motors formulated in terms of stress intensity factors...assumed for Solithane 113. The present program was aimed at evaluating the Schapery theory when it was applied to a CMDB propellant under similar loading

  4. Double-Diffusive Convection in Rotational Shear

    DTIC Science & Technology

    2015-03-01

    CONVECTION IN ROTATIONAL SHEAR by James S. Ball March 2015 Thesis Advisor: Timour Radko Second Reader: John Colosi THIS PAGE...AND SUBTITLE 5. FUNDING NUMBERS DOUBLE-DIFFUSIVE CONVECTION IN ROTATIONAL SHEAR 6. AUTHOR(S) James S. Ball 7. PERFORMING ORGANIZATION NAME(S) AND...INTENTIONALLY LEFT BLANK ii Approved for public release;distribution is unlimited DOUBLE-DIFFUSIVE CONVECTION IN ROTATIONAL SHEAR James S. Ball

  5. Robotic-assisted double-sleeve lobectomy

    PubMed Central

    Qiu, Tong; Zhao, Yandong; Xuan, Yunpeng

    2017-01-01

    Double-sleeve lobectomy, which includes bronchoplasty and pulmonary arterial angioplasty, is required for certain cases of central-type lung cancer. It is usually done by open surgery or video-assisted thoracoscopic surgery (VATS). In recently, da Vinci system and robotic surgery have been applied in such complicated cases. Here we describe the details associated with robotic-assisted double-sleeve lobectomy. PMID:28203433

  6. Decay properties of double heavy baryons

    SciTech Connect

    Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery; Ivanov, Mikhail A.; Koerner, Juergen G.

    2010-08-05

    We study the semileptonic decays of double heavy baryons using a manifestly Lorentz covariant constituent three-quark model. We present complete results on transition form factors between double-heavy baryons for finite values of the heavy quark/baryon masses and in the heavy quark symmetry limit which is valid at and close to zero recoil. Decay rates are calculated and compared to each other in the full theory, keeping masses finite, and also in the heavy quark limit.

  7. [Veterinary double-monsters historically viewed].

    PubMed

    Baljet, B; Heijke, G C

    1997-01-01

    A large number of duplication monstrosities have been observed in cattle, sheep, pigs, horses, goats, cats and dogs, ever since the publication of the famous woodcut of a swine double monster by J. S. Brant in Basel in 1496, better known as the "wunderbare Sau von Landser im Elsass". Albrecht Dürer also made a woodcut of this double monster in front of the village Landser in 1496. A picture of a deer double monster was published in 1603 by Heinrich Ulrich in Germany. In the monograph De monstrorum causis, natura et differentiis ..., published by the Italian Fortunius Licetus in 1616 pictures of double monsters being half man half dog are found. These fantasy figures have been popular for a long time and were supposed to be really in existence. Apart from these fantasy figures many pictures are known from real veterinary double monsters. U. Aldrovandus described in 1642 in his Monstrorum historia, besides many fantasy figures, also real human and veterinary double monsters and he gave also good pictures of them. In the 19th century examples of veterinary duplication monstrosities were published by I. Geoffroy Saint-Hilaire (1832-37), E. F. Gurlt (1832), W. Vrolik (1840) and C. Taruffi (1881); they proposed also concepts concerning the etiology. In the second volume of his famous handbook of teratology (1907), E. Schwalbe described many veterinary double monsters and discussed the theories of the genesis of congenital malformations. Various theories concerning the genesis of double monsters have been given since Aristotle (384-322 B.C.). ...

  8. Wavelength-doubling optical parametric oscillator

    DOEpatents

    Armstrong, Darrell J.; Smith, Arlee V.

    2007-07-24

    A wavelength-doubling optical parametric oscillator (OPO) comprising a type II nonlinear optical medium for generating a pair of degenerate waves at twice a pump wavelength and a plurality of mirrors for rotating the polarization of one wave by 90 degrees to produce a wavelength-doubled beam with an increased output energy by coupling both of the degenerate waves out of the OPO cavity through the same output coupler following polarization rotation of one of the degenerate waves.

  9. The HIPPARCOS Double and Multiple Star Solutions

    NASA Astrophysics Data System (ADS)

    Mignard, F.

    The Hipparcos catalogue provides general astrometric and photometric information on double and multiple stars in specific fields of the main catalogue and detailed data on the components in the various sections of a dedicated annex: the Double and Multiple Systems Annex (DMSA). Overall statistics of these solutions are presented for the 13,211 entries of this annex and the different types of solutions are outlined.

  10. Double shell tank waste analysis plan

    SciTech Connect

    Mulkey, C.H.; Jones, J.M.

    1994-12-15

    Waste analysis plan for the double shell tanks. SD-WM-EV-053 is Superseding SD-WM-EV-057.This document provides the plan for obtaining information needed for the safe waste handling and storage of waste in the Double Shell Tank Systems. In Particular it addresses analysis necessary to manage waste according to Washington Administrative Code 173-303 and Title 40, parts 264 and 265 of the Code of Federal Regulations.

  11. Speckle Reduction in Double-Pass Retinal Images Using Variable-Focus Lenses

    NASA Astrophysics Data System (ADS)

    García-Guerra, C. E.; Aldaba, M.; Arjona, M.; Pujol, J.

    2015-01-01

    Speckle arises in double-pass images when coherent light is scattered by the retina. Since this noise degrades the images that are used to characterize the eye, there is special attention in reducing speckle when working with instruments based on retina reflections. In this work, we present a method for speckle reduction in double-pass retinal images by producing minor periodic variations in the vergence of the beam entering the eye with a variable-focus lens during image recording. Measurements in an artificial and a real eye following the implementation of the method corroborate the speckle reduction.

  12. Double aneuploidy in spontaneous miscarriages: two case reports and review of the literature.

    PubMed

    Korucuoglu, Umit; Erdem, Mehmet; Pala, Elif; Karaoguz, Meral Yirmibes; Erdem, Ahmet; Biri, Aydan

    2008-01-01

    The occurrence of double aneuploidy is a relatively rare phenomenon. The clinical presentations are variable depending on the predominating aneuploidy or a combination effect of both. We report the cytogenetic data on products of conception from miscarriages over a period of 5 years. A total of 403 miscarriages were karyotyped and the tissues were villi in all cases. Of 403 cases, 54 cases with single aneuploidy and 2 cases of first-trimester miscarriages with double trisomies were found. These 2 cases with the karyotypes of 48,XXY,+15 and 48,XX,+5,+7 were cited for the first time in this study.

  13. High resolution atomic force microscopy of double-stranded RNA

    NASA Astrophysics Data System (ADS)

    Ares, Pablo; Fuentes-Perez, Maria Eugenia; Herrero-Galán, Elías; Valpuesta, José M.; Gil, Adriana; Gomez-Herrero, Julio; Moreno-Herrero, Fernando

    2016-06-01

    Double-stranded (ds) RNA mediates the suppression of specific gene expression, it is the genetic material of a number of viruses, and a key activator of the innate immune response against viral infections. The ever increasing list of roles played by dsRNA in the cell and its potential biotechnological applications over the last decade has raised an interest for the characterization of its mechanical properties and structure, and that includes approaches using Atomic Force Microscopy (AFM) and other single-molecule techniques. Recent reports have resolved the structure of dsDNA with AFM at unprecedented resolution. However, an equivalent study with dsRNA is still lacking. Here, we have visualized the double helix of dsRNA under near-physiological conditions and at sufficient resolution to resolve the A-form sub-helical pitch periodicity. We have employed different high-sensitive force-detection methods and obtained images with similar spatial resolution. Therefore, we show here that the limiting factors for high-resolution AFM imaging of soft materials in liquid medium are, rather than the imaging mode, the force between the tip and the sample and the sharpness of the tip apex.Double-stranded (ds) RNA mediates the suppression of specific gene expression, it is the genetic material of a number of viruses, and a key activator of the innate immune response against viral infections. The ever increasing list of roles played by dsRNA in the cell and its potential biotechnological applications over the last decade has raised an interest for the characterization of its mechanical properties and structure, and that includes approaches using Atomic Force Microscopy (AFM) and other single-molecule techniques. Recent reports have resolved the structure of dsDNA with AFM at unprecedented resolution. However, an equivalent study with dsRNA is still lacking. Here, we have visualized the double helix of dsRNA under near-physiological conditions and at sufficient resolution to

  14. Double peak sensory responses: effects of capsaicin.

    PubMed

    Aprile, I; Tonali, P; Stalberg, E; Di Stasio, E; Caliandro, P; Foschini, M; Vergili, G; Padua, L

    2007-10-01

    The aim of this study is to verify whether degeneration of skin receptors or intradermal nerve endings by topical application of capsaicin modifies the double peak response obtained by submaximal anodal stimulation. Five healthy volunteers topically applied capsaicin to the finger-tip of digit III (on the distal phalanx) four times daily for 4-5 weeks. Before and after local capsaicin applications, we studied the following electrophysiological findings: compound sensory action potential (CSAP), double peak response, sensory threshold and double peak stimulus intensity. Local capsaicin application causes disappearance or decrease of the second component of the double peak, which gradually increases after the suspension of capsaicin. Conversely, no significant differences were observed for CSAP, sensory threshold and double peak stimulus intensity. This study suggests that the second component of the double peak may be a diagnostic tool suitable to show an impairment of the extreme segments of sensory nerve fibres in distal sensory axonopathy in the early stages of damage, when receptors or skin nerve endings are impaired but undetectable by standard nerve conduction studies.

  15. Fluid dynamics of double diffusive systems

    SciTech Connect

    Koseff, J.R.

    1989-04-07

    A study of mixing processes in doubly diffusive systems is being conducted. Continuous gradients of two diffusing components (heat and salinity in our case) are being used as initial conditions, and forcing is introduced by lateral heating and surface shear. The goals of the proposed work include: (1) quantification of the effects of finite amplitude disturbances on stable, double diffusive systems, particularly with respect to lateral heating, (2) development of an improved understanding of the physical phenomena present in wind-driven shear flows in double diffusive stratified environments, (3) increasing our knowledge-base on turbulent flow in stratified environments and how to represent it, and (4) formulation of a numerical code for such flows. The work is being carried out in an experimental facility which is located in the Stanford Environmental Fluid Mechanics Laboratory, and on laboratory minicomputers and CRAY computers. In particular we are focusing on the following key issues: (1) the formation and propagation of double diffusive intrusions away from a heated wall and the effects of lateral heating on the double diffusive system; (2) the interaction between the double diffusively influenced fluxes and the turbulence induced fluxes; (3) the measurement of heat and mass fluxes; and (4) the influence of double diffusive gradients on mixed layer deepening. 1 fig.

  16. The Design and its Verification of the Double Rotor Double Cage Induction Motor

    NASA Astrophysics Data System (ADS)

    Sinha, Sumita; Deb, Nirmal K.; Biswas, Sujit K.

    2017-02-01

    The concept of a double rotor motor presented earlier and its equivalent circuit has been developed, showing a non-linear parameter content. The two rotors (which are recommended to be double cage type for development of high starting torque) can run with equal or unequal speed independently, depending on their individual loading. This paper presents the elaborate design procedure, step-by-step, for the double rotor double cage motor and verifies the designed data with that obtained from three separate tests (compared to two for conventional motor) on a prototype, such that optimum performance can be obtained from the motor.

  17. Quantum gates by periodic driving

    PubMed Central

    Shi, Z. C.; Wang, W.; Yi, X. X.

    2016-01-01

    Topological quantum computation has been extensively studied in the past decades due to its robustness against decoherence. One way to realize the topological quantum computation is by adiabatic evolutions—it requires relatively long time to complete a gate, so the speed of quantum computation slows down. In this work, we present a method to realize single qubit quantum gates by periodic driving. Compared to adiabatic evolution, the single qubit gates can be realized at a fixed time much shorter than that by adiabatic evolution. The driving fields can be sinusoidal or square-well field. With the sinusoidal driving field, we derive an expression for the total operation time in the high-frequency limit, and an exact analytical expression for the evolution operator without any approximations is given for the square well driving. This study suggests that the period driving could provide us with a new direction in regulations of the operation time in topological quantum computation. PMID:26911900

  18. Advanced downhole periodic seismic generator

    DOEpatents

    Hardee, Harry C.; Hills, Richard G.; Striker, Richard P.

    1991-07-16

    An advanced downhole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  19. Down hole periodic seismic generator

    DOEpatents

    Hardee, Harry C.; Hills, Richard G.; Striker, Richard P.

    1989-01-01

    A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  20. Families of asymmetric periodic solutions in the restricted four-body problem

    NASA Astrophysics Data System (ADS)

    Papadakis, K. E.

    2016-12-01

    Very recently, we presented five of the basic families of the network of periodic orbits of the restricted four-body problem which are simple, i.e. one intersection with the horizontal x-axis at the half period, symmetric with respect to the same axis and asymmetric with respect to the vertical y-axis. In the present work, using these families, we found series of asymmetric critical orbits for various values of the primaries m2 and m3. From these critical orbits we calculate and present five new families of simple periodic orbits which are asymmetric with respect to both the x- and y-axis. Additionally, we describe a grid method in the (x0, dot{x}0) plane and we obtain initial conditions for new asymmetric double-periodic orbits. We determine ten families of asymmetric double-periodic orbits from the bifurcations of the previous five asymmetric families using the special generating horizontally critical periodic orbits. The stability of each calculated asymmetric periodic orbit is also studied. Characteristic curves as well as stability diagrams of these families are illustrated. In the last section we present the evolution of the five basic families of simple asymmetric periodic orbits when the primaries are the Sun the Jupiter and the 2797 Teucer Asteroid.

  1. Overlay metrology for double patterning processes

    NASA Astrophysics Data System (ADS)

    Leray, Philippe; Cheng, Shaunee; Laidler, David; Kandel, Daniel; Adel, Mike; Dinu, Berta; Polli, Marco; Vasconi, Mauro; Salski, Bartlomiej

    2009-03-01

    The double patterning (DPT) process is foreseen by the industry to be the main solution for the 32 nm technology node and even beyond. Meanwhile process compatibility has to be maintained and the performance of overlay metrology has to improve. To achieve this for Image Based Overlay (IBO), usually the optics of overlay tools are improved. It was also demonstrated that these requirements are achievable with a Diffraction Based Overlay (DBO) technique named SCOLTM [1]. In addition, we believe that overlay measurements with respect to a reference grid are required to achieve the required overlay control [2]. This induces at least a three-fold increase in the number of measurements (2 for double patterned layers to the reference grid and 1 between the double patterned layers). The requirements of process compatibility, enhanced performance and large number of measurements make the choice of overlay metrology for DPT very challenging. In this work we use different flavors of the standard overlay metrology technique (IBO) as well as the new technique (SCOL) to address these three requirements. The compatibility of the corresponding overlay targets with double patterning processes (Litho-Etch-Litho-Etch (LELE); Litho-Freeze-Litho-Etch (LFLE), Spacer defined) is tested. The process impact on different target types is discussed (CD bias LELE, Contrast for LFLE). We compare the standard imaging overlay metrology with non-standard imaging techniques dedicated to double patterning processes (multilayer imaging targets allowing one overlay target instead of three, very small imaging targets). In addition to standard designs already discussed [1], we investigate SCOL target designs specific to double patterning processes. The feedback to the scanner is determined using the different techniques. The final overlay results obtained are compared accordingly. We conclude with the pros and cons of each technique and suggest the optimal metrology strategy for overlay control in double

  2. Chen’s Double Eyelid Fold Ratio

    PubMed Central

    Chen, Chen-Chia; Tai, Hao-Chih

    2016-01-01

    Background: Double eyelidplasty can construct palpebral folds and enhance beauty perception for Asians with single eyelids. A new palpebral parameter for the quantitative interpretation of surgical outcomes is proposed on the basis of a photometric study of the altered proportions of Asian eyes after double eyelid operation. Methods: A total of 100 Asian adults with single upper eyelids who were satisfied with the enlarged eyes by operation were included in the study. A retrospective measurement of palpebral parameters in the frontal profile both preoperatively and 6 months postoperatively was performed. The proportions of various parameters in the eyebrow–eye aesthetic unit were calculated and analyzed. Results: Double eyelidplasty can augment the vertical dimension of palpebral fissure by 27.9% increase on average. The vertical ratio of palpebral fissure to the eyebrow–eye unit is augmented by 34.4% increase. The vertical ratio of the subunit below double eyelid fold peak to the unit is augmented by 82.6% increase. Conclusions: Double eyelidplasty can substantially enlarge the vertical dimensions of the eyes of Asians with single eyelids. The eyes are perceived to be larger because of the visually assimilated illusion of the superimposed eyelid fold and the relative proportions of the eyebrow–eye unit. The authors propose using a vertical ratio of the subunit below double eyelid fold peak in the eyebrow–eye unit to measure the visually perceived proportion of the eye in the unit. This ratio can be applied clinically for a quantitative evaluation of the surgical outcome after double eyelidplasty. PMID:27200243

  3. Experimental and theoretical description of higher order periods in cardiac tissue action potential duration

    NASA Astrophysics Data System (ADS)

    Herndon, Conner; Fenton, Flavio; Uzelac, Ilija

    Much theoretical, experimental, and clinical research has been devoted to investigating the initiation of cardiac arrhythmias by alternans, the first period doubling bifurcation in the duration of cardiac action potentials. Although period doubling above alternans has been shown to exist in many mammalian hearts, little is understood about their emergence or behavior. There currently exists no physiologically correct theory or model that adequately describes and predicts their emergence in stimulated tissue. In this talk we present experimental data of period 2, 4, and 8 dynamics and a mathematical model that describes these bifurcations. This model extends current cell models through the addition of memory and includes spatiotemporal nonlinearities arising from cellular coupling by tissue heterogeneity.

  4. Explosive double salts and preparation

    DOEpatents

    Cady, Howard H.; Lee, Kien-yin

    1984-01-01

    Applicants have discovered a new composition of matter which is an explosive addition compound of ammonium nitrate (AN) and diethylenetriamine trinitrate (DETN) in a 50:50 molar ratio. The compound is stable over extended periods of time only at temperatures higher than 46.degree. C., decomposing to a fine-grained eutectic mixture (which is also believed to be new) of AN and DETN at temperatures lower than 46.degree. C. The compound of the invention has an x-ray density of 1.61 g/cm.sup.3, explodes to form essentially only gaseous products, has higher detonation properties (i.e., detonation velocity and pressure) than those of any mechanical mixture having the same density and composition as the compound of the invention, is a quite insensitive explosive material, can be cast at temperatures attainable by high pressure steam, and is prepared from inexpensive ingredients. Methods of preparing the compound of the invention and the fine-grained eutectic composition of the invention are given.

  5. The importance of planetary rotation period for ocean heat transport.

    PubMed

    Cullum, J; Stevens, D; Joshi, M

    2014-08-01

    The climate and, hence, potential habitability of a planet crucially depends on how its atmospheric and ocean circulation transports heat from warmer to cooler regions. However, previous studies of planetary climate have concentrated on modeling the dynamics of atmospheres, while dramatically simplifying the treatment of oceans, which neglects or misrepresents the effect of the ocean in the total heat transport. Even the majority of studies with a dynamic ocean have used a simple so-called aquaplanet that has no continental barriers, which is a configuration that dramatically changes the ocean dynamics. Here, the significance of the response of poleward ocean heat transport to planetary rotation period is shown with a simple meridional barrier--the simplest representation of any continental configuration. The poleward ocean heat transport increases significantly as the planetary rotation period is increased. The peak heat transport more than doubles when the rotation period is increased by a factor of ten. There are also significant changes to ocean temperature at depth, with implications for the carbon cycle. There is strong agreement between the model results and a scale analysis of the governing equations. This result highlights the importance of both planetary rotation period and the ocean circulation when considering planetary habitability.

  6. The Importance of Planetary Rotation Period for Ocean Heat Transport

    PubMed Central

    Stevens, D.; Joshi, M.

    2014-01-01

    Abstract The climate and, hence, potential habitability of a planet crucially depends on how its atmospheric and ocean circulation transports heat from warmer to cooler regions. However, previous studies of planetary climate have concentrated on modeling the dynamics of atmospheres, while dramatically simplifying the treatment of oceans, which neglects or misrepresents the effect of the ocean in the total heat transport. Even the majority of studies with a dynamic ocean have used a simple so-called aquaplanet that has no continental barriers, which is a configuration that dramatically changes the ocean dynamics. Here, the significance of the response of poleward ocean heat transport to planetary rotation period is shown with a simple meridional barrier—the simplest representation of any continental configuration. The poleward ocean heat transport increases significantly as the planetary rotation period is increased. The peak heat transport more than doubles when the rotation period is increased by a factor of ten. There are also significant changes to ocean temperature at depth, with implications for the carbon cycle. There is strong agreement between the model results and a scale analysis of the governing equations. This result highlights the importance of both planetary rotation period and the ocean circulation when considering planetary habitability. Key Words: Exoplanet—Oceans—Rotation—Climate—Habitability. Astrobiology 14, 645–650. PMID:25041658

  7. Down-Turner Syndrome: A Case with Double Monoclonal Chromosomal Abnormality.

    PubMed

    Manassero-Morales, Gioconda; Alvarez-Manassero, Denisse; Merino-Luna, Alfredo

    2016-01-01

    Introduction. The coexistence of Down and Turner syndromes due to double chromosome aneuploidy is very rare; it is even more rare to find the presence of a double monoclonal chromosomal abnormality. Objective. To report a unique case of double monoclonal chromosomal abnormality with trisomy of chromosome 21 and an X ring chromosome in all cells studied; no previous report has been found. Case Report. Female, 28 months old, with pathological short stature from birth, with the following dysmorphic features: tilted upward palpebral fissures, short neck, brachycephaly, and low-set ears. During the neonatal period, the infant presented generalized hypotonia and lymphedema of hands and feet. Karyotype showed 47,X,r(X),+21 [30]. Conclusion. Clinical features of both Down and Turner syndromes were found, highlighting short stature that has remained below 3 z score from birth to the present, associated with delayed psychomotor development. G-banded karyotype analysis in peripheral blood is essential for a definitive diagnosis.

  8. Double-hybrid density-functional theory applied to molecular crystals

    NASA Astrophysics Data System (ADS)

    Sharkas, Kamal; Toulouse, Julien; Maschio, Lorenzo; Civalleri, Bartolomeo

    2014-07-01

    We test the performance of a number of two- and one-parameter double-hybrid approximations, combining semilocal exchange-correlation density functionals with periodic local second-order Møller-Plesset (LMP2) perturbation theory, for calculating lattice energies of a set of molecular crystals: urea, formamide, ammonia, and carbon dioxide. All double-hybrid methods perform better on average than the corresponding Kohn-Sham calculations with the same functionals, but generally not better than standard LMP2. The one-parameter double-hybrid approximations based on the PBEsol density functional give lattice energies per molecule with an accuracy of about 6 kJ/mol, which is similar to the accuracy of LMP2. This conclusion is further verified on molecular dimers and on the hydrogen cyanide crystal.

  9. Dual-comb spectroscopy using frequency-doubled combs around 775 nm.

    PubMed

    Potvin, Simon; Genest, Jérôme

    2013-12-16

    Two frequency-doubled combs are generated by nonlinear frequency conversion to realize spectroscopic measurements around 775 nm. Frequency-doubled interferograms are corrected in real-time by monitoring the relative instabilities between the combs at their fundamental frequency. Rubidium absorption lines are used to demonstrate the technique's accuracy and serve as absolute references to calibrate the frequency grid of computed spectra. The method allows frequency-doubled interferograms to be averaged without distortion during long periods of time. The calibrated frequency grid is validated by the measurement of the oxygen A-band. Moreover, the measurement analysis of the acetylene ν(1) + 3ν(3) overtone band has revealed some discrepancies with previous publications.

  10. Multiple-path Quantum Interference Effects in a Double-Aharonov-Bohm Interferometer.

    PubMed

    Yang, Xf; Liu, Ys

    2010-05-22

    We investigate quantum interference effects in a double-Aharonov-Bohm (AB) interferometer consisting of five quantum dots sandwiched between two metallic electrodes in the case of symmetric dot-electrode couplings by the use of the Green's function equation of motion method. The analytical expression for the linear conductance at zero temperature is derived to interpret numerical results. A three-peak structure in the linear conductance spectrum may evolve into a double-peak structure, and two Fano dips (zero conductance points) may appear in the quantum system when the energy levels of quantum dots in arms are not aligned with one another. The AB oscillation for the magnetic flux threading the double-AB interferometer is also investigated in this paper. Our results show the period of AB oscillation can be converted from 2π to π by controlling the difference of the magnetic fluxes threading the two quantum rings.

  11. Double free flaps for reconstruction of complex/composite defects in head and neck surgery.

    PubMed

    Mo, Kevin W L; Vlantis, Alexander; Wong, Eddy W Y; Chiu, T W

    2014-08-01

    OBJECTIVE. To demonstrate the feasibility of double free flap surgery in head and neck reconstruction. DESIGN. Descriptive case series. SETTING. A university-affiliated hospital in Hong Kong. PATIENTS. Twelve patients with head and neck cancer (encountered over a 2.5-year period) who had reconstructive surgery with planned simultaneous double free flaps. RESULTS. The mean total operating time was 660 minutes and there were no flap failures. Postoperative stays ranged from 11 to 82 days; nine patients were discharged within 3 weeks and seven were able to maintain their weight with oral feeding. The survival rate up to 1 year was 64%. CONCLUSION. The use of double free flaps is an option worth considering for complex head and neck defects in carefully selected patients.

  12. Haemocytic periodicity and periodic disorders: Periodic neutropenia, thrombocytopenia, lymphocytosis and anaemia

    PubMed Central

    Reimann, Hobart A.

    1971-01-01

    Evidence has accumulated of rhythmic numerical oscillation of each of the blood cells either independently or in combinations. The cyclic changes originate in the marrow of some normal persons and animals without causing illness, and can be induced experimentally. In more than 100 reported instances, periodic oscillations of various cells were accompanied by respective episodes of the disorders named in the title. The disorders may be transitory but usually recur throughout life and occasionally are fatal. All resist therapy. Features in common suggest an interrelationship of the haemal disorders and other disparate heritable periodic diseases. Theoretically, the rhythms are regulated by ubiquitous, inherent, intracellular bioclocks controlled hypothalamically or neurohumorally in relation to a feedback mechanism. Reactions to long cycles are of greater clinical importance than disturbances arising from the circadian rhythm. PMID:4397784

  13. The First SLR Double-Difference Baseline

    NASA Astrophysics Data System (ADS)

    Svehla, Drazen; Haagmans, Roger; Floberghagen, Rune; Cacciapuoti, Luigi; Sierk, Bernd; Kirchner, Georg; Rodriguez, Jose; Wilkinson, Matthew; Sherwood, Rob; Appleby, Graham

    2013-04-01

    We introduce the SLR double-difference approach of space geodesy. With real and simulated SLR measurements it is shown how common SLR biases are removed by forming SLR double-differences, i.e. station range biases, common retro-reflector effects and orbit errors (GNSS) for baselines up to e.g. 5000 km. In this way we obtain SLR observables of utmost precision and accuracy. We show how remaining noise in the SLR measurements nicely averages out, leading to orbit-free and bias-free estimation of station coordinates, local ties between different space geodesy techniques and precise comparison of optical/microwave tropospheric effects. It shall be noted that SLR scale is preserved by double-differencing. When ETALON and LAGEOS satellites are observed by SLR, any orbit error propagates directly into estimated station coordinates. However, by forming differences between two satellites and two ground stations this orbit error can be eliminated. Both satellites need to be observed quasi-simultaneously in the same tracking sessions in order that station range bias and common retro-reflector effects are removed by differencing. When SLR measurements from GRZL and HERL SLR stations are taken to GLONASS and LAGEOS satellites and processed in double-difference mode, clear common orbit errors are visible in the SLR residuals from both stations. The same stands for small range biases that are visible between the consecutive observing sessions and are removed by forming SLR baselines. Longer SLR passes reveal other interesting systematic effects common to both stations at mm-level. An error in the order of 4-6 cm RMS was introduced to GNSS orbits, however the effect on station coordinates in negligible over such a short SLR baseline. We show how with just one-two SLR double-difference passes one can estimate station coordinates at mm-level. When in parallel, both GNSS satellites are observed with microwave measurements, one can estimate very accurate local ties by comparing (or

  14. Effects of sputtering period on the performance of Cu2ZnSnS4 solar cells

    NASA Astrophysics Data System (ADS)

    Lu, Yilei; Wang, Shurong; Li, Zhishan; Jiang, Zhi; Yang, Min; Li, Qi

    2017-02-01

    Currently, most of investigations about CZTS focus on the sulfurization conditions, the precursor stacking orders, and effects of secondary phases on the device performance. However, very few researchers have a detailed investigation of sputtering period. In this paper, the effects of sputtering period on the performance of Cu2ZnSnS4 solar cells are discussed. The crystal structure, morphology, chemical composition and phase purity of CZTS thin films prepared by different periods were characterized by X-Ray Diffraction(XRD), scanning electron microscopy(SEM) equipped with an energy dispersive spectrometer(EDS) and Raman spectroscopy. The results show that the performances of CZTS devices prepared by multi periods were better than that of using single period. Meanwhile, complete devices were fabricated using CZTS thin film based on different sputtering periods, and 2.02% efficiency of CZTS by single period, 3.19% efficiency by double periods and 3.6% efficiency by four periods were obtained, respectively.

  15. Rotational period of GQ Lupi

    NASA Astrophysics Data System (ADS)

    Broeg, C.; Schmidt, T. O. B.; Guenther, E.; Gaedke, A.; Bedalov, A.; Neuhäuser, R.; Walter, F. M.

    2007-06-01

    Aims: We wanted to determine the rotation parameters of GQ Lup A, thereby constraining the evolutionary history of the GQ Lup system. Methods: We have undertaken a photometric monitoring campaign on GQ Lup A consisting of two epochs spaced one year apart. We also searched the photometric archives to enlarge the data set. Results: We were able to determine the photometric period (8.45±0.2 days) in both epochs in several photometric bands. This periodicity could also be found in some of the archival data. The combined false-alarm probability is 0.015. The variation is most likely caused by hot spots on the surface of GQ Lup A. This, combined with high-resolution spectra (v sin i) allows calculation of GQ Lup A's inclination (i=27±5°). Radial velocity data also contains this period but is inconclusive. Nevertheless, the RV data supports the interpretation that hot spots cause the photometric variation. We use the known K-band variability, amplitude, and phase of GQ Lup A together with a new image of GQ Lup A+b, taken quasi-simultaneously with our monitoring of the star, to confirm the magnitude and, hence, luminosity of the companion. Based on observations obtained on Cerro Paranal, Chile, in ESO program 075.C-0710(C) and on La Silla, Chile, in ESO programs 074.C-0034(A),075.C-0710(E), 075.C-0710(F), 075.C-0202(A), 076.C-0010(A) as well as with ANDICAM of the SMARTS consortium. Photometry data of epochs I and II are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/468/1039

  16. Re-naming D Double Prime

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    1999-01-01

    "Knowledge about the dynamics of the D double prime region is a key to unlock some fundamental mysteries of the Earth heat engine which governs a wide range of global geophysical processes from tectonics to geodynamo." This benign sentence makes complete sense to many geophysicists. But for many others, it makes sense all except the odd nomenclature "D double prime". One knows about the crust, upper and lower mantle, outer and inner core, but where is the D double prime region? What meaning does it try to convey? Where is D prime region, or D, or A, B, C regions for that matter, and are there higher-order primes? How does such an odd name come about anyway? D double prime, or more "simply" D", is a generic designation given to the thin shell, about 200 km thick, of the lowermost mantle just above the core-mantle boundary inside the Earth. Incidentally, whether D" is "simpler" than "D double prime" depends on whether you are pronouncing it or writing/typing it; and D" can be confusing to readers in distinguishing quotation marks (such as in the above sentences) and second derivatives, and to word processors in spelling check and indexing.

  17. Double tube helical coil steam generator

    SciTech Connect

    Garabedian, G.; De Luca, R.A.

    1987-02-24

    A steam generator is described comprising a container having a closed lower end, divided into longitudinally arranged sections including an uppermost disengaging chamber, an upper plenum, and a lower plenum. The upper plenum is above the lower plenum and contains a multiplicity of double tube helical coils, wherein each of the double tube helical coils is comprised of an inner tube individually enclosed for at least a portion of its length by an outer tube to form a double tube portion and thereby define an annular gap which is outside the inner tube but enclosed by the outer tube; the inner tube being attached at one end to a feedwater inlet, and the inner tube being attached at the other end to a steam outlet; the outer tube being in open communication at both ends with the disengaging chamber; the double tube portion being in the configuration of a helix for part of its length; the upper plenum having no communication with the disengaging chamber and having restricted communication with the lower plenum such that liquid metal entering the upper plenum and flowing to the lower plenum closely contacts at least a portion of the double tube helical coils; and the annular gap being at least partially filled with liquid metal.

  18. Electron acceleration in stochastic double layers

    NASA Technical Reports Server (NTRS)

    Lotko, William

    1987-01-01

    Transversely localized double layers evolve randomly in turbulent regions of strongly magnetized plasma carrying current along the magnetic field. Results from numerical simulations and spacecraft observations in the auroral plasma indicate that the parallel electric field in such regions is microscopically intermittent or stochastic. The implications of stochastic double layer fields on electron acceleration will be discussed in terms of a statistical process involving ensemble averages over test particle motion. A Fokker-Planck equation can be derived for the electron phase space density, which depends on the mean and rms amplitudes of the double layers, the mean double layer density, and the initial electron velocity distribution. It is shown that the resulting electron acceleration is very sensitive to the ratio of the initial electron energy to the rms double layer amplitude. When this ratio is large, the acceleration process differs little from that expected in a dc electric field. When it is small, stochastic heating competes with directed acceleration. Evidence for both cases can be found in the auroral ionosphere in association with so-called inverted-V precipitation and collimated edge precipitation.

  19. Double-difference adjoint seismic tomography

    NASA Astrophysics Data System (ADS)

    Yuan, Yanhua O.; Simons, Frederik J.; Tromp, Jeroen

    2016-09-01

    We introduce a `double-difference' method for the inversion for seismic wave speed structure based on adjoint tomography. Differences between seismic observations and model predictions at individual stations may arise from factors other than structural heterogeneity, such as errors in the assumed source-time function, inaccurate timings and systematic uncertainties. To alleviate the corresponding non-uniqueness in the inverse problem, we construct differential measurements between stations, thereby reducing the influence of the source signature and systematic errors. We minimize the discrepancy between observations and simulations in terms of the differential measurements made on station pairs. We show how to implement the double-difference concept in adjoint tomography, both theoretically and practically. We compare the sensitivities of absolute and differential measurements. The former provide absolute information on structure along the ray paths between stations and sources, whereas the latter explain relative (and thus higher resolution) structural variations in areas close to the stations. Whereas in conventional tomography a measurement made on a single earthquake-station pair provides very limited structural information, in double-difference tomography one earthquake can actually resolve significant details of the structure. The double-difference methodology can be incorporated into the usual adjoint tomography workflow by simply pairing up all conventional measurements; the computational cost of the necessary adjoint simulations is largely unaffected. Rather than adding to the computational burden, the inversion of double-difference measurements merely modifies the construction of the adjoint sources for data assimilation.

  20. Temperature-stable double SAW resonators.

    PubMed

    Martin, Guenter; Kunze, Reinhard; Wall, Bert

    2008-01-01

    The temperature stability of SAW resonators on quartz can be enhanced by means of double resonators. The turnover temperatures of the double resonators' components, called single resonators, are positioned above and below room temperature. As a consequence, the temperature coefficients of frequency of the 1st order (TCF1) have opposite signs at room temperature, leading to the vanishing TCF1 of the double resonators. Frequently, different turnover temperatures are adjusted by different propagation directions on an ST cut of quartz. An overview of known and new methods for compensating the temperature coefficient of frequency of the 2nd order (TCF2) of two-port and one-port SAW double resonators is given. A concept by means of which temperature-stable circuits of single resonators are found is described. Two types of temperature-stable double resonators found by applying that concept are treated in detail: 1) a two-port resonator composed of two cascaded two-port resonators and a coupling inductance, and 2) a one-port resonator comprising a series connection of one-port resonators with an inductance in parallel with each single resonator. The substrates are 35.5 degrees rotY cuts of quartz. In both cases, the shift of resonance frequency within the temperature range from -30 degrees C to 70 degrees C is smaller than 20 ppm.

  1. 43 CFR 10010.45 - Time periods.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Time periods. 10010.45 Section 10010.45... Environmental Impact Statements § 10010.45 Time periods. (a) The minimum review period for a draft EIS will be... proposed reductions in time periods or any extensions of time periods proposed by those agencies....

  2. 44 CFR 206.112 - Registration period.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Registration period. 206.112... Households § 206.112 Registration period. (a) Initial period. The standard FEMA registration period is 60...) Extension of the registration period. The regional administrator or his/her designee may extend...

  3. 44 CFR 206.112 - Registration period.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Registration period. 206.112... Households § 206.112 Registration period. (a) Initial period. The standard FEMA registration period is 60...) Extension of the registration period. The regional administrator or his/her designee may extend...

  4. 44 CFR 206.112 - Registration period.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Registration period. 206.112... Households § 206.112 Registration period. (a) Initial period. The standard FEMA registration period is 60...) Extension of the registration period. The regional administrator or his/her designee may extend...

  5. 44 CFR 206.112 - Registration period.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Registration period. 206.112... Households § 206.112 Registration period. (a) Initial period. The standard FEMA registration period is 60...) Extension of the registration period. The regional administrator or his/her designee may extend...

  6. 44 CFR 206.112 - Registration period.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Registration period. 206.112... Households § 206.112 Registration period. (a) Initial period. The standard FEMA registration period is 60...) Extension of the registration period. The regional administrator or his/her designee may extend...

  7. 43 CFR 10010.45 - Time periods.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Time periods. 10010.45 Section 10010.45... Environmental Impact Statements § 10010.45 Time periods. (a) The minimum review period for a draft EIS will be... proposed reductions in time periods or any extensions of time periods proposed by those agencies....

  8. 43 CFR 10010.45 - Time periods.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Time periods. 10010.45 Section 10010.45... Environmental Impact Statements § 10010.45 Time periods. (a) The minimum review period for a draft EIS will be... proposed reductions in time periods or any extensions of time periods proposed by those agencies....

  9. 43 CFR 10010.45 - Time periods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Time periods. 10010.45 Section 10010.45... Environmental Impact Statements § 10010.45 Time periods. (a) The minimum review period for a draft EIS will be... proposed reductions in time periods or any extensions of time periods proposed by those agencies....

  10. The concept of double inlet-double outlet right ventricle: a distinct congenital heart disease.

    PubMed

    Spadotto, Veronica; Frescura, Carla; Ho, Siew Yen; Thiene, Gaetano

    The aim of this study was to estimate the incidence and to analyze the anatomy of double inlet-double outlet right ventricle complex and its associated cardiac anomalies in our autopsy series. Among the 1640 hearts with congenital heart disease of our Anatomical Collection, we reviewed the specimens with double inlet-double outlet right ventricle, according to the sequential-segmental analysis, identifying associated cardiac anomalies and examining lung histology to assess the presence of pulmonary vascular disease. We identified 14 hearts with double inlet-double outlet right ventricle (0.85%). Right atrial isomerism was observed in 10 hearts, situs solitus in 3 and left atrial isomerism in one. Regarding the mode of atrioventricular connection, all hearts but one had a common atrioventricular valve. Systemic or pulmonary venous abnormalities were noted in all patients with atrial isomerism. In nine patients a valvular or subvalvular pulmonary stenosis was present. Among the functionally "univentricular hearts", double inlet- double outlet right ventricle represents a peculiar entity, mostly in association with right atrial isomerism. Multiple cardiac anomalies are associated and may complicate surgical repair.

  11. Long-Period Solar Variability

    SciTech Connect

    GAUTHIER,JOHN H.

    2000-07-20

    Terrestrial climate records and historical observations of the Sun suggest that the Sun undergoes aperiodic oscillations in radiative output and size over time periods of centuries and millenia. Such behavior can be explained by the solar convective zone acting as a nonlinear oscillator, forced at the sunspot-cycle frequency by variations in heliomagnetic field strength. A forced variant of the Lorenz equations can generate a time series with the same characteristics as the solar and climate records. The timescales and magnitudes of oscillations that could be caused by this mechanism are consistent with what is known about the Sun and terrestrial climate.

  12. Periodic permanent magnet focused klystron

    DOEpatents

    Ferguson, Patrick; Read, Michael; Ives, R Lawrence

    2015-04-21

    A periodic permanent magnet (PPM) klystron has beam transport structures and RF cavity structures, each of which has permanent magnets placed substantially equidistant from a beam tunnel formed about the central axis, and which are also outside the extent of a cooling chamber. The RF cavity sections also have permanent magnets which are placed substantially equidistant from the beam tunnel, but which include an RF cavity coupling to the beam tunnel for enhancement of RF carried by an electron beam in the beam tunnel.

  13. Chronic speciation in periodical cicadas.

    PubMed

    Ritchie, M G.

    2001-02-01

    Allochronic speciation and reproductive character displacement are two intuitively attractive models of speciation. The first proposes that changes in the timing of life cycles produce new species, whereas the second suggests that speciation is due to the exaggeration of sexual isolation in sympatric populations. Clear examples of either process in nature remain elusive, despite some extensive searches. Two recent studies of mtDNA markers and behaviour of periodical cicadas in North America have identified a new species of cicada that seems to provide good evidence for the involvement of both processes in its origin.

  14. Pattern Dynamics in Taylor Vortex Flow with Double Hourglass Geometry

    NASA Astrophysics Data System (ADS)

    Wiener, Richard; Olsen, Thomas

    2005-11-01

    In previous investigations ootnotetextWiener et al., Phys. Rev. E 55, 5489 (1997) & Phys. Rev. Lett. 83, 2340 (1999) we have demonstrated experimentally that Taylor vortex flow in an hourglass geometry undergoes a period-doubling cascade to chaotic pattern dynamics that can be controlled by proportional feedback with small perturbations. The hourglass geometry creates a spatial ramp in the Reynolds number. This results in a region of supercritical vortex flow between regions of subcritical structureless flow that provide the pattern with soft boundaries that allow for persistent dynamics. For a range of reduced Reynolds numbers, the Taylor vortex pattern exhibits persistent dynamics consisting of drifting and stretching vortices punctuated with phase slips. Each phase slip corresponds to the generation of a new vortex pair. We are currently investigating the phase dynamics of Tayor vortex flow with a double hourglass geometry which consists of two regions of supercritical flow in which phase slips occur, separated by a narrow region of subcritical flow. Initial results indicate that at some reduced Reynolds numbers there is synchronization between the vortex dynamics in the two regions, both in the temporal occurrence of the phase slips as well as the drift directions of the vortices.

  15. High power double-scale pulses from a gain-guided double-clad fiber laser

    NASA Astrophysics Data System (ADS)

    Zhang, Haitao; Gao, Gan; Li, Qinghua; Gong, Mali

    2017-03-01

    Generation of high power double-scale pulses from a gain-guided double-clad fiber laser is experimentally demonstrated. By employing the Yb-doped 10/130 double-clad fiber as the gain medium, the laser realizes an output power of 5.1 W and pulse energy of 0.175 µJ at repetition rate of 29.14 MHz. To the best of our knowledge, this average output power is the highest among the reported double-scale pulse oscillators. The autocorrelation trace of pulses contains the short (98 fs) and long (29.5 ps) components, and the spectral bandwidth of the pulse is 27.3 nm. Such double-scale pulses are well suited for seeding the high power MOPA (master oscillator power amplifier) systems, nonlinear frequency conversion and optical coherence tomography.

  16. Diet of double-crested cormorants wintering in Texas

    USGS Publications Warehouse

    Campo, J.J.; Thompson, B.C.; Barron, J.C.; Telfair II, R. C.; Durocher, P.; Gutreuter, S.

    1993-01-01

    The diets of 420 Double-crested Cormorants (Phalacrocorax auritus) were studied during November 1986-March 1987 on eight public reservoirs in Texas. Prey included 29 fish species and the mean live weight of fish per bird was 122 g. Fishes a??415 mm long were ingested, but those a??125 mm accounted for 90% of cormorant food contents by number. Shad (Dorosoma spp.) and sunfishes (Lepomis spp.) accounted for 90% of the total food items by number. Consumption of fishes (percent by weight) was different for male vs. female and adult vs. juvenile cormorants. Total consumption of fish by weight was consistent throughout the period; however, fewer but much larger fish were consumed after 15 February. Cormorants ate fishes that were most abundant in reservoirs. Sport fishes made up a substantial portion of cormorant food by weight, but not by number on some reservoirs. Cormorants ate very few large sport fish, however.

  17. DoubleSun® Performance Across Mainland Portugal

    NASA Astrophysics Data System (ADS)

    Reis, F.; Silva, J.; Leandro, R.; Botelho, D.; Wemans, J.; Sorasio, G.; Brito, M. C.

    2011-12-01

    Photovoltaic (PV) technology has been gaining a significant share in Portugal's renewable energy mix. In this paper we focus on the analysis of 29 PV systems (mounted and connected to the grid under the micro-generation incentive scheme in Portugal), from which 59% are DoubleSun® technology, the remaining being flat-plate systems. The period in analysis is July 2009-June 2010. A preliminary analysis of the PV systems has confirmed their high potential in Portugal and highlighted the relevance of such analysis to identify: (1) the geographical characterization of PV performance across mainland Portugal; (2) improvement of a tool [1] that predicts the potential of different PV technologies; and (3) the challenges of PV systems when installed on-field and connected to the grid.

  18. Nonholonomic double-bracket equations and the Gauss thermostat.

    PubMed

    Rojo, Alberto G; Bloch, Anthony M

    2009-08-01

    In this Rapid Communication we consider certain equations that arise from imposing a constant kinetic-energy constraint on a one-dimensional set of oscillators. This is a nonlinear nonholonomic constraint on these oscillators and the dynamics are consistent with Gauss's law of least constraint. Dynamics of this sort are of interest in nonequilibrium molecular dynamics. We show that under certain choices of external potential these equations give rise to a generalization of the so-called double-bracket equations which are of interest in studying gradient flows and integrable systems such as the Toda lattice. In the case of harmonic potentials the flow is described by a symmetric bracket and periodic solutions are obtained.

  19. Double inlet ventricle. Lung biopsy findings and implications for management.

    PubMed Central

    Juaneda, E; Haworth, S G

    1985-01-01

    The lung was biopsied in 20 children with double inlet ventricle and pulmonary hypertension aged 2 months to 14 years. Eleven patients had two patent atrioventricular valves, three atresia of the right valve, and six hypoplasia of the left valve. Severe pulmonary arterial medial hypertrophy occurred in the nine children less than 1 year of age. The findings did not suggest a period of normality after birth when the pulmonary artery might have been banded most effectively. Of the 11 older patients, eight had medial hypertrophy and three intimal proliferation with medial atrophy. Six patients with medial hypertrophy had some reduction in pulmonary arterial pressure after banding. It is recommended that the pulmonary artery be banded as early as possible, and rebanded early if a satisfactory result is not obtained, particularly in patients destined for a Fontan-Kreutzer procedure. Early atrial septectomy should reduce the arterial and venous abnormalities seen in left atrioventricular valve hypoplasia. PMID:3994865

  20. Double Planet Meets Triple Star

    NASA Astrophysics Data System (ADS)

    2002-08-01

    High-Resolution VLT Image of Pluto Event on July 20, 2002 A rare celestial phenomenon involving the distant planet Pluto has occurred twice within the past month. Seen from the Earth, this planet moved in front of two different stars on July 20 and August 21, respectively, providing observers at various observatories in South America and in the Pacific area with a long awaited and most welcome opportunity to learn more about the tenuous atmosphere of that cold planet. On the first date, a series of very sharp images of a small sky field with Pluto and the star was obtained with the NAOS-CONICA (NACO) adaptive optics (AO) camera mounted on the ESO VLT 8.2-m YEPUN telescope at the Paranal Observatory. With a diameter of about 2300 km, Pluto is about six times smaller than the Earth. Like our own planet, it possesses a relatively large moon, Charon , measuring 1200 km across and circling Pluto at a distance of about 19,600 km once every 6.4 days. In fact, because of the similarity of the two bodies, the Pluto-Charon system is often referred to as a double planet . At the current distance of nearly 4,500 million km from the Earth, Pluto's disk subtends a very small angle in the sky, 0.107 arcsec. It is therefore very seldom that Pluto - during its orbital motion - passes exactly in front of a comparatively bright star. Such events are known as "occultations" , and it is difficult to predict exactly when and where on the Earth's surface they are visible. Stellar occultations When Pluto moves in front of a star, it casts a "shadow" on the Earth's surface within which an observer cannot see the star, much like the Earth's Moon hides the Sun during a total solar eclipse. During the occultation event, Pluto's "shadow" also moves across the Earth's surface. The width of this shadow is equal to Pluto's diameter, i.e. about 2300 km. One such occultation event was observed in 1988, and two others were expected to occur in 2002, according to predictions published in 2000 by

  1. A model for periodic blazars

    NASA Astrophysics Data System (ADS)

    Sobacchi, Emanuele; Sormani, Mattia C.; Stamerra, Antonio

    2017-02-01

    We describe a scenario to explain blazar periodicities with time-scales of ˜ few years. The scenario is based on a binary supermassive black hole (SMBH) system in which one of the two SMBHs carries a jet. We discuss the various mechanisms that can cause the jet to precess and produce corkscrew patterns through space with a scale of ˜ few pc. It turns out that the dominant mechanism responsible for the precession is simply the imprint of the jet-carrying SMBH orbital speed on the jet. Gravitational deflection and Lense-Thirring precession (due to the gravitational field of the other SMBH) are second-order effects. We complement the scenario with a kinematical jet model which is inspired to the spine-sheath structure observed in M87. One of the main advantages of such a structure is that it allows the peak of the synchrotron emission to scale with frequency according to νF ∝ νξ as the viewing angle is changed, where ξ is not necessarily 3 or 4 as in the case of jets with uniform velocity, but can be ξ ˜ 1. Finally, we apply the model to the source PG1553+113, which has been recently claimed to show a Tobs = (2.18 ± 0.08) yr periodicity. We are able to reproduce the optical and gamma-ray light curves and multiple synchrotron spectra simultaneously. We also give estimates of the source mass and size.

  2. The Dissolution of Double Holliday Junctions

    PubMed Central

    Bizard, Anna H.; Hickson, Ian D.

    2014-01-01

    Double Holliday junctions (dHJS) are important intermediates of homologous recombination. The separate junctions can each be cleaved by DNA structure-selective endonucleases known as Holliday junction resolvases. Alternatively, double Holliday junctions can be processed by a reaction known as “double Holliday junction dissolution.” This reaction requires the cooperative action of a so-called “dissolvasome” comprising a Holliday junction branch migration enzyme (Sgs1/BLM RecQ helicase) and a type IA topoisomerase (Top3/TopoIIIα) in complex with its OB (oligonucleotide/oligosaccharide binding) fold containing accessory factor (Rmi1). This review details our current knowledge of the dissolution process and the players involved in catalyzing this mechanistically complex means of completing homologous recombination reactions. PMID:24984776

  3. Machine learning bandgaps of double perovskites

    NASA Astrophysics Data System (ADS)

    Pilania, Ghanshyam; Mannodi-Kanakkithodi, Arun; Uberuaga, Blas; Ramprasad, Rampi; Gubernatis, James; Lookman, Turab

    The ability to make rapid and accurate predictions of bandgaps for double perovskites is of much practical interest for a range of applications. While quantum mechanical computations for high-fidelity bandgaps are enormously computation-time intensive and thus impractical in high throughput studies, informatics-based statistical learning approaches can be a promising alternative. Here we demonstrate a systematic feature-engineering approach and a robust learning framework for efficient and accurate predictions of electronic bandgaps for double perovskites. After evaluating a set of nearly 1.2 million features, we identify several elemental features of the constituent atomic species as the most crucial and relevant predictors. The developed models are validated and tested using the best practices of data science (on a dataset of more than 1300 double perovskite bandgaps) and further analyzed to rationalize their prediction performance. Los Alamos National Laboratory LDRD program and the U.S. Department of Energy, Office of Science, Basic Energy Sciences.

  4. Double Dirac Semimetals in Three Dimensions.

    PubMed

    Wieder, Benjamin J; Kim, Youngkuk; Rappe, A M; Kane, C L

    2016-05-06

    We study a class of Dirac semimetals that feature an eightfold-degenerate double Dirac point. We show that 7 of the 230 space groups can host such Dirac points and argue that they all generically display linear dispersion. We introduce an explicit tight-binding model for space groups 130 and 135. Space group 135 can host an intrinsic double Dirac semimetal with no additional states at the Fermi energy. This defines a symmetry-protected topological critical point, and we show that a uniaxial compressive strain applied in different directions leads to topologically distinct insulating phases. In addition, the double Dirac semimetal can accommodate topological line defects that bind helical modes. Connections are made to theories of strongly interacting filling-enforced semimetals, and potential materials realizations are discussed.

  5. Double Dirac Semimetals in Three Dimensions

    NASA Astrophysics Data System (ADS)

    Wieder, Benjamin J.; Kim, Youngkuk; Rappe, A. M.; Kane, C. L.

    2016-05-01

    We study a class of Dirac semimetals that feature an eightfold-degenerate double Dirac point. We show that 7 of the 230 space groups can host such Dirac points and argue that they all generically display linear dispersion. We introduce an explicit tight-binding model for space groups 130 and 135. Space group 135 can host an intrinsic double Dirac semimetal with no additional states at the Fermi energy. This defines a symmetry-protected topological critical point, and we show that a uniaxial compressive strain applied in different directions leads to topologically distinct insulating phases. In addition, the double Dirac semimetal can accommodate topological line defects that bind helical modes. Connections are made to theories of strongly interacting filling-enforced semimetals, and potential materials realizations are discussed.

  6. Double Ramification Cycles and Quantum Integrable Systems

    NASA Astrophysics Data System (ADS)

    Buryak, Alexandr; Rossi, Paolo

    2016-03-01

    In this paper, we define a quantization of the Double Ramification Hierarchies of Buryak (Commun Math Phys 336:1085-1107, 2015) and Buryak and Rossi (Commun Math Phys, 2014), using intersection numbers of the double ramification cycle, the full Chern class of the Hodge bundle and psi-classes with a given cohomological field theory. We provide effective recursion formulae which determine the full quantum hierarchy starting from just one Hamiltonian, the one associated with the first descendant of the unit of the cohomological field theory only. We study various examples which provide, in very explicit form, new (1+1)-dimensional integrable quantum field theories whose classical limits are well-known integrable hierarchies such as KdV, Intermediate Long Wave, extended Toda, etc. Finally, we prove polynomiality in the ramification multiplicities of the integral of any tautological class over the double ramification cycle.

  7. Genetics Home Reference: hypokalemic periodic paralysis

    MedlinePlus

    ... Home Health Conditions hypokalemic periodic paralysis hypokalemic periodic paralysis Enable Javascript to view the expand/collapse boxes. ... PDF Open All Close All Description Hypokalemic periodic paralysis is a condition that causes episodes of extreme ...

  8. Genetics Home Reference: hyperkalemic periodic paralysis

    MedlinePlus

    ... Home Health Conditions hyperkalemic periodic paralysis hyperkalemic periodic paralysis Enable Javascript to view the expand/collapse boxes. ... PDF Open All Close All Description Hyperkalemic periodic paralysis is a condition that causes episodes of extreme ...

  9. Hamilton Jeffers and the Double Star Catalogues

    NASA Astrophysics Data System (ADS)

    Tenn, Joseph S.

    2013-01-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Court reporter and amateur astronomer Shelburne Wesley Burnham (1838-1921) published a massive double star catalogue containing more than 13,000 systems in 1906. The next keeper of the double stars was Lick Observatory astronomer Robert Grant Aitken (1864-1951), who produced a much larger catalogue in 1932. Aitken maintained and expanded Burnham’s records of observations on handwritten file cards, eventually turning them over to Lick Observatory astrometrist Hamilton Moore Jeffers (1893-1976). Jeffers further expanded the collection and put all the observations on punched cards. With the aid of Frances M. "Rete" Greeby (1921-2002), he made two catalogues: an Index Catalogue with basic data about each star, and a complete catalogue of observations, with one observation per punched card. He enlisted Willem van den Bos of Johannesburg to add southern stars, and they published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers approached retirement he became greatly concerned about the disposition of the catalogues. He wanted to be replaced by another "double star man," but Lick Director Albert E. Whitford (1905-2002) had the new 120-inch reflector, the world’s second largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers was vociferously opposed to turning over the card files to another institution, and especially against their coming under the control of Kaj Strand of the U.S. Naval Observatory. In the end the USNO got the files and has maintained the records ever since, first under Charles Worley (1935-1997), and, since 1997, under Brian Mason. Now called the Washington Double Star Catalog (WDS), it is completely online and currently contains more than 1,000,000 measures of more than 100,000 pairs.

  10. Doubling the dose of budesonide versus maintenance treatment in asthma exacerbations

    PubMed Central

    FitzGerald, J; Becker, A; Sears, M; Mink, S; Chung, K; Lee, J

    2004-01-01

    Background: Previous guidelines recommend doubling the daily dose of maintenance inhaled corticosteroid to treat or prevent progression of exacerbations of asthma. Methods: Over a 6 month period a cohort of patients were evaluated prospectively and randomised in a double blind controlled trial to treatment with either a continued maintenance dose (MD) of inhaled corticosteroid or doubling the dose (DD) at the time of an exacerbation. Results: A total of 290 patients were randomised (33% male) and 98 (DD, n = 46) experienced evaluable asthma exacerbations during the study period. Mean (SD) baseline characteristics at randomisation (age 33.5 (14.0) years; forced expiratory volume in 1 second (FEV1) 2.8 (0.7) l; peak expiratory flow (PEF) 422.9 (110.5) l/min) were similar in both groups. In the DD group 41% of patients were considered treatment failures because they either required systemic steroids (n = 12), had an unscheduled visit to a physician (n = 1), or their asthma did not return to baseline (n = 6). This did not differ from the MD group in which 40% were treatment failures (n = 9, 0, and 12, respectively; p = 0.94). Conclusions: In patients who regularly take an inhaled corticosteroid, doubling the maintenance dose may not affect the pattern of the exacerbation. PMID:15223858

  11. Relativistic contributions to single and double core electron ionization energies of noble gases.

    PubMed

    Niskanen, J; Norman, P; Aksela, H; Agren, H

    2011-08-07

    We have performed relativistic calculations of single and double core 1s hole states of the noble gas atoms in order to explore the relativistic corrections and their additivity to the ionization potentials. Our study unravels the interplay of progression of relaxation, dominating in the single and double ionization potentials of the light elements, versus relativistic one-electron effects and quantum electrodynamic effects, which dominate toward the heavy end. The degree of direct relative additivity of the relativistic corrections for the single electron ionization potentials to the double electron ionization potentials is found to gradually improve toward the heavy elements. The Dirac-Coulomb Hamiltonian is found to predict a scaling ratio of ∼4 for the relaxation induced relativistic energies between double and single ionization. Z-scaling of the computed quantities were obtained by fitting to power law. The effects of nuclear size and form were also investigated and found to be small. The results indicate that accurate predictions of double core hole ionization potentials can now be made for elements across the full periodic table.

  12. Double conformal space-time algebra

    NASA Astrophysics Data System (ADS)

    Easter, Robert Benjamin; Hitzer, Eckhard

    2017-01-01

    The Double Conformal Space-Time Algebra (DCSTA) is a high-dimensional 12D Geometric Algebra G 4,8that extends the concepts introduced with the Double Conformal / Darboux Cyclide Geometric Algebra (DCGA) G 8,2 with entities for Darboux cyclides (incl. parabolic and Dupin cyclides, general quadrics, and ring torus) in spacetime with a new boost operator. The base algebra in which spacetime geometry is modeled is the Space-Time Algebra (STA) G 1,3. Two Conformal Space-Time subalgebras (CSTA) G 2,4 provide spacetime entities for points, flats (incl. worldlines), and hyperbolics, and a complete set of versors for their spacetime transformations that includes rotation, translation, isotropic dilation, hyperbolic rotation (boost), planar reflection, and (pseudo)spherical inversion in rounds or hyperbolics. The DCSTA G 4,8 is a doubling product of two G 2,4 CSTA subalgebras that inherits doubled CSTA entities and versors from CSTA and adds new bivector entities for (pseudo)quadrics and Darboux (pseudo)cyclides in spacetime that are also transformed by the doubled versors. The "pseudo" surface entities are spacetime hyperbolics or other surface entities using the time axis as a pseudospatial dimension. The (pseudo)cyclides are the inversions of (pseudo)quadrics in rounds or hyperbolics. An operation for the directed non-uniform scaling (anisotropic dilation) of the bivector general quadric entities is defined using the boost operator and a spatial projection. DCSTA allows general quadric surfaces to be transformed in spacetime by the same complete set of doubled CSTA versor (i.e., DCSTA versor) operations that are also valid on the doubled CSTA point entity (i.e., DCSTA point) and the other doubled CSTA entities. The new DCSTA bivector entities are formed by extracting values from the DCSTA point entity using specifically defined inner product extraction operators. Quadric surface entities can be boosted into moving surfaces with constant velocities that display the length

  13. Superballistic wavepacket spreading in double kicked rotors

    NASA Astrophysics Data System (ADS)

    Fang, Ping; Wang, Jiao

    2016-08-01

    We investigate possible ways in which a quantum wavepacket spreads. We show that in a general class of double kicked rotor system, a wavepacket may undergo superballistic spreading; i.e., its variance increases as the cubic of time. The conditions for the observed superballistic spreading and two related characteristic time scales are studied. Our results suggest that the symmetry of the studied model and whether it is a Kolmogorov-Arnold-Moser system are crucial to its wavepacket spreading behavior. Our study also sheds new light on the exponential wavepacket spreading phenomenon previously observed in the double kicked rotor system.

  14. Double photoionization of hydrocarbons and aromatic molecules

    NASA Astrophysics Data System (ADS)

    Wehlitz, R.

    2016-11-01

    This article reviews the recent progress in the field of double photoionization of hydrocarbons and aromatic molecules using synchrotron radiation. First I will describe the importance of carbon-based molecules, which are all around us and are literally part of our life. They exhibit intriguing properties some of which can be probed via double photoionization, i.e., the simultaneous emission of two electrons. Furthermore, I will discuss the different mechanisms that can lead to a doubly charged organic molecule and will highlight those findings by comparing them with the results for atoms and other (simple) molecules. Finally, I will give an outlook on future directions on this subject.

  15. The double-beta decay: Theoretical challenges

    SciTech Connect

    Horoi, Mihai

    2012-11-20

    Neutrinoless double beta decay is a unique process that could reveal physics beyond the Standard Model of particle physics namely, if observed, it would prove that neutrinos are Majorana particles. In addition, it could provide information regarding the neutrino masses and their hierarchy, provided that reliable nuclear matrix elements can be obtained. The two neutrino double beta decay is an associate process that is allowed by the Standard Model, and it was observed for about ten nuclei. The present contribution gives a brief review of the theoretical challenges associated with these two process, emphasizing the reliable calculation of the associated nuclear matrix elements.

  16. Molecular mechanism of double Holliday junction dissolution

    PubMed Central

    2014-01-01

    Processing of homologous recombination intermediates is tightly coordinated to ensure that chromosomal integrity is maintained and tumorigenesis avoided. Decatenation of double Holliday junctions, for example, is catalysed by two enzymes that work in tight coordination and belong to the same ‘dissolvasome’ complex. Within the dissolvasome, the RecQ-like BLM helicase provides the translocase function for Holliday junction migration, while the topoisomerase III alpha-RMI1 subcomplex works as a proficient DNA decatenase, together resulting in double-Holliday-junction unlinking. Here, we review the available architectural and biochemical knowledge on the dissolvasome machinery, with a focus on the structural interplay between its components. PMID:25061510

  17. Probing Angular Correlations in Sequential Double Ionization

    SciTech Connect

    Fleischer, A.; Woerner, H. J.; Arissian, L.; Liu, L. R.; Meckel, M.; Rippert, A.; Doerner, R.; Villeneuve, D. M.; Corkum, P. B.; Staudte, A.

    2011-09-09

    We study electron correlation in sequential double ionization of noble gas atoms and HCl in intense, femtosecond laser pulses. We measure the photoelectron angular distributions of Ne{sup +} relative to the first electron in a pump-probe experiment with 8 fs, 800 nm, circularly polarized laser pulses at a peak intensity of a few 10{sup 15} W/cm{sup 2}. Using a linear-linear pump-probe setup, we further study He, Ar, and HCl. We find a clear angular correlation between the two ionization steps in the sequential double ionization intensity regime.

  18. Probabilistic double guarantee kidnapping detection in SLAM.

    PubMed

    Tian, Yang; Ma, Shugen

    2016-01-01

    For determining whether kidnapping has happened and which type of kidnapping it is while a robot performs autonomous tasks in an unknown environment, a double guarantee kidnapping detection (DGKD) method has been proposed. The good performance of DGKD in a relative small environment is shown. However, a limitation of DGKD is found in a large-scale environment by our recent work. In order to increase the adaptability of DGKD in a large-scale environment, an improved method called probabilistic double guarantee kidnapping detection is proposed in this paper to combine probability of features' positions and the robot's posture. Simulation results demonstrate the validity and accuracy of the proposed method.

  19. An acoustic double fishnet using Helmholtz resonators.

    PubMed

    Murray, A R J; Summers, I R; Sambles, J R; Hibbins, A P

    2014-09-01

    The acoustic transmission of a closely spaced pair of patterned and perforated rigid plates is explored in air. The structure resembles an acoustic double fishnet design, with each plate modified such that the gap between them acts as an array of Helmholtz resonators. This allows the center frequency of the stop band to be reduced by a factor greater than 2 from the value obtained for the conventional acoustic double fishnet design. Experimental results accord well with the predictions of a finite element model.

  20. Higher spin double field theory: a proposal

    NASA Astrophysics Data System (ADS)

    Bekaert, Xavier; Park, Jeong-Hyuck

    2016-07-01

    We construct a double field theory coupled to the fields present in Vasiliev's equations. Employing the "semi-covariant" differential geometry, we spell a functional in which each term is completely covariant with respect to O(4, 4) T-duality, doubled diffeomorphisms, Spin(1, 3) local Lorentz symmetry and, separately, HS(4) higher spin gauge symmetry. We identify a minimal set of BPS-like conditions whose solutions automatically satisfy the full Euler-Lagrange equations. As such a solution, we derive a linear dilaton vacuum. With extra algebraic constraints further supplemented, the BPS-like conditions reduce to the bosonic Vasiliev equations.