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Sample records for laminar-turbulent characteristic time

  1. Stochastic analysis of the time evolution of laminar-turbulent bands of plane Couette flow.

    PubMed

    Rolland, Joran

    2015-11-01

    This article is concerned with the time evolution of the oblique laminar-turbulent bands of transitional plane Couette flow under the influence of turbulent noise. Our study is focused on the amplitude of modulation of turbulence (the bands). In order to guide the numerical study of the flow, we first perform an analytical and numerical analysis of a Stochastic Ginzburg-Landau (GL) equation for a complex order parameter. The modulus of this order parameter models the amplitude of modulation of turbulence. Firstly, we compute the autocorrelation function of said modulus once the band is established. Secondly, we perform a calculation of average and fluctuations around the exponential growth of the order parameter. This type of analysis is similar to the Stochastic Structural Stability Theory (S3T). We then perform numerical simulations of the Navier-Stokes equations in order to confront these predictions with the actual behaviour of the bands. Computation of the autocorrelation function of the modulation of turbulence shows quantitative agreement with the model: in the established band regime, the amplitude of modulation follows an Ornstein-Uhlenbeck process. In order to test the S3T predictions, we perform quench experiments, sudden decreases of the Reynolds number from uniform turbulence, in which modulation appears. We compute the average evolution of the amplitude of modulation and the fluctuations around it. We find good agreement between numerics and modeling. The average trajectory grows exponentially, at a rate clearly smaller than that of the formation of laminar holes. Meanwhile, the actual time evolution remains in a flaring envelope, centered on the average, and expanding at the same rate. These results provide further validation of the stochastic modeling for the time evolution of the bands for further studies. Besides, they stress on the difference between the oblique band formation and the formation of laminar holes.

  2. Laminar-turbulent transition delay on a swept wing

    NASA Astrophysics Data System (ADS)

    Borodulin, V. I.; Ivanov, A. V.; Kachanov, Y. S.; Hanifi, A.

    2016-10-01

    The paper describes the results of experiments on robustness of laminar-turbulent transition control on a swept-wing using distributed micro-sized roughness (DMSR) elements. These elements introduce controlled stationary vortices which are able to significantly modify the base flow and its stability characteristics. We have performed parametric study first varying height and period of the DMSR elements in order to find the most stabilizing effect on boundary later flow in compare to uncontrolled reference case without DMSR. Significant downstream shift of laminar-turbulent transition position due to application of DMSR is found and well documented with help of thermography. The robustness of this flow control method was studied by variation of the wind-tunnel flow quality introducing significant sound background or introducing enhanced turbulence level (applying turbulizing grids). The wind-tunnel tests performed with turbulence-generating grids (at enhanced turbulence levels) have shown that laminar-turbulent transition moves upstream in this case, while DMSR-elements loose their effectiveness for transition control (no matter in quiet sound conditions or at elevated sound background). The experiments on acoustic influence have shown that without DMSR acoustic does not effect transition location. However, in case then laminar-turbulent transition is delayed by presence of DMSR, an additional transition delay was observed when harmonic acoustic waves of certain frequency were excited.

  3. Effect of the surface roughness of blunt cone forebody on the position of laminar-turbulent transition

    NASA Astrophysics Data System (ADS)

    Bountin, D. A.; Gromyko, Yu. V.; Maslov, A. A.; Polivanov, P. A.; Sidorenko, A. A.

    2016-09-01

    In the present paper, data on the effect of the surface roughness of blunt cone forebody on the position of laminar-turbulent transition are reported. The study was carried out under freestream Mach 5.95. It was found that the roughness position plays a substantial role in the transition process. Critical Reynolds numbers at which the laminar-turbulent transition occurs on the nose-tip of the model were identified. For the first time, hysteresis in transition position was observed.

  4. Numerical Investigation of Laminar-Turbulent Transition in a Flat Plate Wake

    DTIC Science & Technology

    1990-03-02

    NUMERICAL INVESTIGATION OF LAMINAR-TURBULENT TRANSITION IN A FLAT PLATE WAKE by David I. Dratler and Hermann F. Fasel D T I C E ECTE MAY 2 5 1990 g...etsear Fows_________________ 12. PERSONAL AUTHOR(S) Hermann F. Fasel and Alan C. Newell 13&. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Yr.. M...discretized velocity equations are solved using fast Helmholtz solvers. Code validation is accomplished by comparison of the numerical results to both

  5. Laminar-Turbulent Transition Behind Discrete Roughness Elements in a High-Speed Boundary Layer

    NASA Technical Reports Server (NTRS)

    Choudhari, Meelan M.; Li, Fei; Wu, Minwei; Chang, Chau-Lyan; Edwards, Jack R., Jr.; Kegerise, Michael; King, Rudolph

    2010-01-01

    Computations are performed to study the flow past an isolated roughness element in a Mach 3.5, laminar, flat plate boundary layer. To determine the effects of the roughness element on the location of laminar-turbulent transition inside the boundary layer, the instability characteristics of the stationary wake behind the roughness element are investigated over a range of roughness heights. The wake flow adjacent to the spanwise plane of symmetry is characterized by a narrow region of increased boundary layer thickness. Beyond the near wake region, the centerline streak is surrounded by a pair of high-speed streaks with reduced boundary layer thickness and a secondary, outer pair of lower-speed streaks. Similar to the spanwise periodic pattern of streaks behind an array of regularly spaced roughness elements, the above wake structure persists over large distances and can sustain strong enough convective instabilities to cause an earlier onset of transition when the roughness height is sufficiently large. Time accurate computations are performed to clarify additional issues such as the role of the nearfield of the roughness element during the generation of streak instabilities, as well as to reveal selected details of their nonlinear evolution. Effects of roughness element shape on the streak amplitudes and the interactions between multiple roughness elements aligned along the flow direction are also investigated.

  6. IR thermography for dynamic detection of laminar-turbulent transition

    NASA Astrophysics Data System (ADS)

    Simon, Bernhard; Filius, Adrian; Tropea, Cameron; Grundmann, Sven

    2016-05-01

    This work investigates the potential of infrared (IR) thermography for the dynamic detection of laminar-turbulent transition. The experiments are conducted on a flat plate at velocities of 8-14 m/s, and the transition of the laminar boundary layer to turbulence is forced by a disturbance source which is turned on and off with frequencies up to 10 Hz. Three different heating techniques are used to apply the required difference between fluid and structure temperature: a heated aluminum structure is used as an internal structure heating technique, a conductive paint acts as a surface bounded heater, while an IR heater serves as an example for an external heating technique. For comparison of all heating techniques, a normalization is introduced and the frequency response of the measured IR camera signal is analyzed. Finally, the different heating techniques are compared and consequences for the design of experiments on laminar-turbulent transition are discussed.

  7. Hypersonic laminar/turbulent transition: computations and experiments

    NASA Astrophysics Data System (ADS)

    Orlik, E.; Kornilov, V.; Ferrier, M.; Fedioun, I.; Davidenko, D.

    2012-01-01

    In order to predict the laminar/turbulent transition on a hypersonic vehicle forebody at Mach numbers 4 and 6, the three-dimensional (3D) modal linear stability analysis is applied, coupled with the eN method. Nevertheless, N factors are unknown for wind tunnel conditions. Experimental investigations have been carried out on a flat plate in the blowdown wind tunnel T-313 of ITAM RAS (Novosibirsk). At M∞ = 2 to 6, the position of laminar/turbulent transition was measured by both Pitot tube and thermocouples. Then, stability analysis allows computing N factors at transition on the flat plate: they are about 3 ˜ 4, typical of conventional wind tunnels. These flat plate correlations can then be used to predict the transition on the forebody in the same wind tunnel. Experiments for the forebody are currently in progress and will allow checking the predicted transition location.

  8. Natural laminar-turbulent transition delay by dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Ustinov, Maxim; Kogan, Mikhail; Litvinov, Vladimir; Uspensky, Alexander

    2011-12-01

    The use dielectric barrier discharge for the delay of laminar turbulent transition excited by natural flow disturbances in a quiet wind-tunnel was investigated experimentally. Optimal electrodes location and the operational regime of high-voltage impulse generator provided maximal downstream shift of transition location were found. It was demonstrated that the 10% increase of the laminar part of boundary layer can be obtained using barrier discharge with the cross-flow electrodes. This gives up to 20% friction drag reduction.

  9. Laminar-turbulent transition on the flying wing model

    NASA Astrophysics Data System (ADS)

    Pavlenko, A. M.; Zanin, B. Yu.; Katasonov, M. M.

    2016-10-01

    Results of an experimental study of a subsonic flow past aircraft model having "flying wing" form and belonging to the category of small-unmanned aerial vehicles are reported. Quantitative data about the structure of the flow near the model surface were obtained by hot-wire measurements. It was shown, that with the wing sweep angle 34 °the laminar-turbulent transition scenario is identical to the one on a straight wing. The transition occurs through the development of a package of unstable oscillations in the boundary layer separation.

  10. On laminar-turbulent transition in nanofluid flows

    NASA Astrophysics Data System (ADS)

    Rudyak, V. Ya.; Minakov, A. V.; Guzey, D. V.; Zhigarev, V. A.; Pryazhnikov, M. I.

    2016-09-01

    The paper presents experimental data on the laminar-turbulent transition in the nanofluid flow in the pipe. The transition in the flows of such fluids is shown to have lower Reynolds numbers than in the base fluid. The degree of the flow destabilization increases with an increase in concentration of nanoparticles and a decrease in their size. On the other hand, in the turbulent flow regime, the presence of particles in the flow leads to the suppression of smallscale turbulent fluctuations. The correlation of the measured viscosity coefficient of considered nanofluids is presented.

  11. Experimental study for the detection of the laminar/turbulent aerodynamic transition on a wing aircraft, using fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Molin, S.; Dolfi, D.; Doisy, M.; Seraudie, A.; Arnal, D.; Coustols, E.; Mandle, J.

    2010-09-01

    We demonstrate the feasibility of detection of the nature (laminar/turbulent/transitional) of the aerodynamic boundary layer of a profile of a wing aircraft model, using a Distributed FeedBack (DFB) Fiber Laser as optical fiber sensor. Signals to be measured are pressure variations : ΔP~1Pa at few 100Hz in the laminar region and ΔP~10Pa at few kHz in the turbulent region. Intermittent regime occurring in-between these two regions (transition) is characterized by turbulent bursts in laminar flow. Relevant pressure variations have been obtained in a low-speed research-type wind tunnel of ONERA Centre of Toulouse. In order to validate the measurements, a "classical" hot film sensor, the application and use of which have been formerly developed and validated by ONERA, has been placed at the neighborhood of the fiber sensor. The hot film allows measurement of the boundary layer wall shear stress whose characteristics are a well known signature of the boundary layer nature (laminar, intermittent or turbulent) [1]. In the three regimes, signals from the fiber sensor and the hot film sensor are strongly correlated, which allows us to conclude that a DFB fiber laser sensor is a good candidate for detecting the boundary layer nature, and thus for future integration in an aircraft wing. The work presented here has been realized within the framework of "Clean Sky", a Joint Technology Initiative of the European Union.

  12. Effect of local heating/cooling on the laminar-turbulent transition on a blunted cone

    NASA Astrophysics Data System (ADS)

    Poplavskaya, T. V.; Bountin, D. A.; Kirilovskiy, S. V.; Maslov, A. A.

    2016-10-01

    Experimental data and results of numerical simulation of a supersonic flow over a blunt cone are presented. Experimental investigations of the effect of local cooling or heating of the nose of the model on the laminar-turbulent transition on sharp and blunt cones were carried out in two hypersonic wind tunnel ITAM SB RAS - IT-302M and "Transit-M." Numerical simulation were performed using the commercial package ANSYS Fluent and transition modelγ- Reθt. The computed results of the heat flux on the cone surface are compared with the data of wind tunnel experiments performed at the flow Mach number M∞ = 5.8 and 5.95. It is shown an ambiguous effect of local impact for different conditions of the flow.

  13. Laminar-turbulent transition on a blunted ogive-conical body at hypersonic speeds

    NASA Astrophysics Data System (ADS)

    Vaganov, A. V.; Noev, A. Yu.; Plyashechnik, V. I.; Radchenko, V. N.; Skuratov, A. S.; Shustov, A. A.

    2016-10-01

    Influence of flow parameters and nose radius on laminar-turbulent transition location is under investigation. Experiments were conducted in shock tunnel at Mach number 6. Transition location was diagnosed by heat transfer rate distribution determined with aid of luminescent temperature converters. Model used was ogive-conical body of revolution having half angle about 9°. Through obtained Reynolds number range (up to Re∞,R = 3.44×105) no transition reversal was observed. Present data are in accordance with the hypothesis that transition reversal is due to formation of turbulence wedges in nosetip region. Highest observed transition onset Reynolds number was about Re∞,Xt ≈ 1.4×107 which is anomaly higher than conventional wind tunnel data for sharp cone at this Mach number range and lies in flight data region.

  14. Laminar-Turbulent Transition in Raman Fiber Lasers: A First Passage Statistics Based Analysis

    PubMed Central

    Chattopadhyay, Amit K.; Nasiev, Diar; Sugavanam, Srikanth; Tarasov, Nikita; Churkin, Dmitry V.

    2016-01-01

    Loss of coherence with increasing excitation amplitudes and spatial size modulation is a fundamental problem in designing Raman fiber lasers. While it is known that ramping up laser pump power increases the amplitude of stochastic excitations, such higher energy inputs can also lead to a transition from a linearly stable coherent laminar regime to a non-desirable disordered turbulent state. This report presents a new statistical methodology, based on first passage statistics, that classifies lasing regimes in Raman fiber lasers, thereby leading to a fast and highly accurate identification of a strong instability leading to a laminar-turbulent phase transition through a self-consistently defined order parameter. The results have been consistent across a wide range of pump power values, heralding a breakthrough in the non-invasive analysis of fiber laser dynamics. PMID:27349282

  15. Supersonic quiet-tunnel development for laminar-turbulent transition research

    NASA Technical Reports Server (NTRS)

    Schneider, Steven P.

    1995-01-01

    This grant supported research into quiet-flow supersonic wind-tunnels, between February 1994 and February 1995. Quiet-flow nozzles operate with laminar nozzle-wall boundary layers, in order to provide low-disturbance flow for studies of laminar-turbulent transition under conditions comparable to flight. Major accomplishments include: (1) development of the Purdue Quiet-Flow Ludwieg Tube, (2) computational evaluation of the square nozzle concept for quiet-flow nozzles, and (3) measurement of the presence of early transition on the flat sidewalls of the NASA LaRC Mach 3.5 supersonic low-disturbance tunnel. Since items (1) and (2) are described in the final report for companion grant NAG1-1133, only item (3) is described here. A thesis addressing the development of square nozzles for high-speed, low-disturbance wind tunnels is included as an appendix.

  16. Laminar-turbulent patterning in wall-bounded shear flows: a Galerkin model

    NASA Astrophysics Data System (ADS)

    Seshasayanan, K.; Manneville, P.

    2015-06-01

    On its way to turbulence, plane Couette flow-the flow between counter-translating parallel plates-displays a puzzling steady oblique laminar-turbulent pattern. We approach this problem via Galerkin modelling of the Navier-Stokes equations. The wall-normal dependence of the hydrodynamic field is treated by means of expansions on functional bases fitting the boundary conditions exactly. This yields a set of partial differential equations for spatiotemporal dynamics in the plane of the flow. Truncating this set beyond the lowest nontrivial order is numerically shown to produce the expected pattern, therefore improving over what was obtained at the cruder effective wall-normal resolution. Perspectives opened by this approach are discussed.

  17. Experimental and numerical study of direct laminar-turbulent transition in Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Crowley, Christopher J.; Krygier, Michael; Borrero-Echeverry, Daniel; Grigoriev, Roman O.; Schatz, Michael F.

    2016-11-01

    The transition to turbulence in large aspect ratio Taylor-Couette flow (TCF) occurs via a sequence of supercritical bifurcations of stable flow states (e.g. spiral vortices, interpenetrating spirals (IPS), and wavy interpenetrating spirals). We previously reported the discovery of a direct laminar-turbulent transition in a TCF system with counter-rotating cylinders (Reo = - 1000 , Rei 640) and a small aspect ratio (Γ = 5 . 26) as Rei is slowly increased. This transition is mediated by an unstable IPS state. As Rei is decreased, the turbulent flow first relaminarizes into an intermediate, stable IPS state, before returning to circular Couette flow. In this talk we will present the study of this transition experimentally using tomographic PIV and direct numerical simulations with realistic boundary conditions, and show that it is both highly repeatable and that it shows hysteresis. The transition between both the IPS and turbulent states exhibits statistics consistent with chaotic attractor transitioning to a chaotic repeller. The IPS state is accessed from a subcritical transition and is inaccessible when the inner cylinder is originally accelerated on the way up to turbulence, suggesting that a finite amplitude perturbation is required to reach it. This work is supported in part by the Army Research Office (Contract # W911NF-16-1-0281).

  18. Effect of roughness of the blunted cone nose-tip on laminar-turbulent transition

    NASA Astrophysics Data System (ADS)

    Bountin, D. A.; Gromyko, Yu. V.; Polivanov, P. A.; Sidorenko, A. A.; Maslov, A. A.

    2016-10-01

    Hypersonic boundary layer stability and transition were studied experimentally and numerically for the test case of 7° cone model with blunt nose-tip. The experiments were performed for M=6, heat flux distributions and wall pressure pulsations were measured. It was obtained that the angle of cover and size of bluntness significantly affects on the transition location. Real hypersonic vehicle is equipped by thermal protection systems (TPS) which have a surface roughness (joints and connecting elements). Furthermore the surface of the elements of TPS is not smooth and has some relatively uniform roughness, which can vary during flight. Roughness size can change during thermal ablation or destruction, in addition elements of isolated roughness comparable with a thickness of the boundary layer may appear on surface (caverns, ledges, etc.,). These elements are additional receptivity areas where the additional perturbations are generated and developing in boundary layer that may cause premature laminar-turbulent transition. This effect has been studied for more than 50 years [17-3], but almost all the work devoted to the search of engineering correlations, but not to receptivity or stability problems. This effect needs to be studied more precisely.

  19. Development of quiet-flow supersonic wind tunnels for laminar-turbulent transition research

    NASA Technical Reports Server (NTRS)

    Schneider, Steven P.

    1994-01-01

    This grant supported research into quiet-flow supersonic wind-tunnels, between May 1990 and December 1994. Quiet-flow nozzles operate with laminar nozzle-wall boundary layers, in order to provide low-disturbance flow for studies of laminar-turbulent transition under conditions comparable to flight. Major accomplishments include: (1) the design, fabrication, and performance-evaluation of a new kind of quiet tunnel, a quiet-flow Ludweig tube; (2) the integration of preexisting codes for nozzle design, 2D boundary-layer computation, and transition-estimation into a single user-friendly package for quiet-nozzle design; and (3) the design and preliminary evaluation of supersonic nozzles with square cross-section, as an alternative to conventional quiet-flow nozzles. After a brief summary of (1), a description of (2) is presented. Published work describing (3) is then summarized. The report concludes with a description of recent results for the Tollmien-Schlichting and Gortler instability in one of the square nozzles previously analyzed.

  20. Development of an Irregularity in the Laminar-Turbulent Transition of the Spot

    NASA Astrophysics Data System (ADS)

    Sekiya, Naoki; Matsumoto, Akira

    A spot, generated by an artificial disturbance introduced into a laminar boundary layer, had a highly reproducibility in its velocity perturbations during the initial stage of its downstream development. Thus, we called it a ``laminar spot'' and investigated its downstream development in detail. The purpose of this study was to investigate the generation and the development of an irregularity observed in the velocity waves during the laminar-turbulent transition of the spot. The results obtained show that those irregularities appeared locally in the low-speed region away from the wall and spread wide close to the wall. In the beginning, lateral distortion of velocity profile due to the vortex-interaction caused the irregularity of the velocity-wave amplitude in the boundary between the low- and high-speed regions in the spot. In addition, the crossover of legs of the longitudinal vortices occurred incidentally in the spot and generated a local ejection of low-momentum fluid. Afterwards, some crossovers of legs were produced in a chain reaction. Consequently, the reproducibility in the velocity waves disappeared almost in the downstream and turbulent regions increased rapidly everywhere in the spot.

  1. Prediction of laminar-turbulent transition on an airfoil at high level of free-stream turbulence

    NASA Astrophysics Data System (ADS)

    Chernoray, V.

    2015-06-01

    Prediction of laminar-turbulent transition at high level of free-stream turbulence in boundary layers of airfoil geometries with external pressure gradient changeover is in focus. The aim is a validation of a transition model for transition prediction in turbomachinery applications. Numerical simulations have been performed by using a transition model by Langtry and Menter for a number of different cases of pressure gradient, at Reynolds-number range, based on the airfoil chord, 50 000 ≤ Re ≤ 500 000, and free-stream turbulence intensities 2% and 4%. The validation of the computational results against the experimental data showed good performance of used turbulence model for all test cases.

  2. On active control of laminar-turbulent transition on two-dimensional wings.

    PubMed

    Erdmann, Ralf; Pätzold, Andreas; Engert, Marcus; Peltzer, Inken; Nitsche, Wolfgang

    2011-04-13

    This paper gives an overview of drag reduction on aerofoils by means of active control of Tollmien-Schlichting (TS) waves. Wind-tunnel experiments at Mach numbers of up to M(x)=0.42 and model Reynolds numbers of up to Re(c)=2 × 10(6), as well as in-flight experiments on a wing glove at Mach numbers of M<0.1 and at a Reynolds number of Re(c)=2.4 × 10(6), are presented. Surface hot wires were used to detect the linearly growing TS waves in the transitional boundary layer. Different types of voice-coil- and piezo-driven membrane actuators, as well as active-wall actuators, located between the reference and error sensors, were demonstrated to be effective in introducing counter-waves into the boundary layer to cancel the travelling TS waves. A control algorithm based on the filtered-x least mean square (FxLMS) approach was employed for in-flight and high-speed wind-tunnel experiments. A model-predictive control algorithm was tested in low-speed experiments on an active-wall actuator system. For the in-flight experiments, a reduction of up to 12 dB (75% TS amplitude) was accomplished in the TS frequency range between 200 and 600 Hz. A significant reduction of up to 20 dB (90% TS amplitude) in the flow disturbance amplitude was achieved in high-speed wind-tunnel experiments in the fundamental TS frequency range between 3 and 8 kHz. A downstream shift of the laminar-turbulent transition of up to seven TS wavelengths is presented. The cascaded sensor-actuator arrangement given by Sturzebecher & Nitsche in 2003 for low-speed wind-tunnel experiments was able to shift the transition Δx=240 mm (18% x/c) downstream by a TS amplitude reduction of 96 per cent (30 dB). By using an active-wall actuator, which is much shorter than the cascaded system, a transition delay of seven TS wavelengths (16 dB TS amplitude reduction) was reached.

  3. Large-eddy simulation of laminar-turbulent breakdown at high speeds with dynamic subgrid-scale modeling

    NASA Technical Reports Server (NTRS)

    El-Hady, Nabil M.

    1993-01-01

    The laminar-turbulent breakdown of a boundary-layer flow along a hollow cylinder at Mach 4.5 is investigated with large-eddy simulation. The subgrid scales are modeled dynamically, where the model coefficients are determined from the local resolved field. The behavior of the dynamic-model coefficients is investigated through both an a priori test with direct numerical simulation data for the same case and a complete large-eddy simulation. Both formulations proposed by Germano et al. and Lilly are used for the determination of unique coefficients for the dynamic model and their results are compared and assessed. The behavior and the energy cascade of the subgrid-scale field structure are investigated at various stages of the transition process. The investigations are able to duplicate a high-speed transition phenomenon observed in experiments and explained only recently by the direct numerical simulations of Pruett and Zang, which is the appearance of 'rope-like' waves. The nonlinear evolution and breakdown of the laminar boundary layer and the structure of the flow field during the transition process were also investigated.

  4. The effect of neutrally buoyant finite-size particles on channel flows in the laminar-turbulent transition regime

    NASA Astrophysics Data System (ADS)

    Loisel, Vincent; Abbas, Micheline; Masbernat, Olivier; Climent, Eric

    2013-12-01

    The presence of finite-size particles in a channel flow close to the laminar-turbulent transition is simulated with the Force Coupling Method which allows two-way coupling with the flow dynamics. Spherical particles with channel height-to-particle diameter ratio of 16 are initially randomly seeded in a fluctuating flow above the critical Reynolds number corresponding to single phase flow relaminarization. When steady-state is reached, the particle volume fraction is homogeneously distributed in the channel cross-section (ϕ ≅ 5%) except in the near-wall region where it is larger due to inertia-driven migration. Turbulence statistics (intensity of velocity fluctuations, small-scale vortical structures, wall shear stress) calculated in the fully coupled two-phase flow simulations are compared to single-phase flow data in the transition regime. It is observed that particles increase the transverse r.m.s. flow velocity fluctuations and they break down the flow coherent structures into smaller, more numerous and sustained eddies, preventing the flow to relaminarize at the single-phase critical Reynolds number. When the Reynolds number is further decreased and the suspension flow becomes laminar, the wall friction coefficient recovers the evolution of the laminar single-phase law provided that the suspension viscosity is used in the Reynolds number definition. The residual velocity fluctuations in the suspension correspond to a regime of particulate shear-induced agitation.

  5. Quantitative evaluation on contributions of laminar, turbulence and secondary flow to momentum and heat transfer in rhombic ducts

    NASA Astrophysics Data System (ADS)

    Fukushima, Naoya

    2016-11-01

    In the present study, Direct Numerical Simulation of turbulent flow in rhombic ducts have been carried out to investigate effects of the corner angle on the friction and heat transfer. Due to secondary flow of the second kind, the friction and heat transfer are enhanced in the corner, while turbulence enhances momentum and heat transfer near the wall away from the corner. In previous studies, turbulence and secondary flows are supposed to enhance momentum and heat transfer, qualitatively. The quantitative estimation of their contribution has not been clarified yet. Fukagata, Iwamoto and Kasagi (2002) have theoretically driven the FIK-identity to evaluate quantitative contributions of laminar and turbulence to the friction in turbulent channel. In this study, the FIK-identity has been numerically applied to DNS data in the rhombic ducts to evaluate quantitative contributions of laminar, turbulence and secondary flow to the momentum and heat transfer. From the results, it is quantitatively clarified that the contributions of turbulence and secondary flow to heat transfer are larger than that to friction in the rhombic ducts.

  6. Modeling the stochastic dynamics of moving turbulent spots over a slender cone at Mach 5 during laminar-turbulent transition

    NASA Astrophysics Data System (ADS)

    Robbins, Brian; Field, Rich; Grigoriu, Mircea; Jamison, Ryan; Mesh, Mikhail; Casper, Katya; Dechant, Lawrence

    2016-11-01

    During reentry, a hypersonic vehicle undergoes a period in which the flow about the vehicle transitions from laminar to turbulent flow. During this transitional phase, the flow is characterized by intermittent formations of localized turbulent behavior. These localized regions of turbulence are born at the onset of transition and grow as they move to the aft end of the flight vehicle. Throughout laminar-turbulent transition, the moving turbulent spots cause pressure fluctuations on the outer surface of the vehicle, which leads to the random vibration of the structure and its internal components. In light of this, it is of great interest to study the dynamical response of a flight vehicle undergoing transitional flow so that aircraft can be better designed to prevent structural failure. In this talk, we present a statistical model that calculates the birth, evolution, and pressure field of turbulent spots over a generic slender cone structure. We then illustrate that the model appropriately quantifies intermittency behavior and pressure loading by comparing the intermittency and root-mean-square pressure fluctuations produced by the model with theory and experiment. Finally, we present results pertaining to the structural response of a housing panel on the slender cone. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  7. Characteristics of 3D instability of a 35-degree swept wing to CF and TS modes. Experiment and theory

    NASA Astrophysics Data System (ADS)

    Borodulin, V. I.; Ivanov, A. V.; Kachanov, Y. S.; Örlü, R.; Hanifi, A.; Hein, S.

    2016-10-01

    An extensive experimental investigation of linear evolution of Cross-Flow (CF) and Tollmien-Schlichting (TS) modes of 3D boundary layer oscillations on a swept wing has been carried out. TS-instability characteristics have been studied experimentally for the first time. The characteristics of development of the two kinds of instability modes are compared with calculations and display a very good agreement. The whole dataset may be used for promotion of theoretical methods of investigation of laminar-turbulent transition in swept wing boundary layers.

  8. Numerical study of laminar-turbulent transition in particle-laden channel flow

    NASA Astrophysics Data System (ADS)

    Klinkenberg, Joy; Sardina, Gaetano; de Lange, H. C.; Brandt, Luca

    2013-04-01

    We present direct numerical simulations of subcritical transition to turbulence in a particle-laden channel flow, with particles assumed rigid, spherical, and heavier than the fluid. The equations describing the fluid flow are solved with an Eulerian mesh, whereas those describing the particle dynamics are solved by Lagrangian tracking. Two-way coupling between fluid and particles is modeled with Stokes drag. The numerical code is first validated against previous results from linear stability: the nonmodal growth of streamwise vortices resulting in streamwise streaks is still the most efficient mechanism for linear disturbance amplification at subcritical conditions as for the case of a single phase fluid. To analyze the full nonlinear transition, we examine two scenarios well studied in the literature: (1) transition initiated by streamwise independent counter-rotating streamwise vortices and one three-dimensional mode and (2) oblique transition, initiated by the nonlinear interaction of two symmetric oblique waves. The threshold energy for transition is computed, and it is demonstrated that for both scenarios the transition may be facilitated by the presence of particles at low number density. This is due to the fact that particles may introduce in the system detrimental disturbances of length scales not initially present. At higher concentrations, conversely, we note an increase of the disturbance energy needed for transition. The threshold energy for the oblique scenario shows a more significant increase in the presence of particles, by a factor about four. Interestingly, for the streamwise-vortex scenario the time at which transition occurs increases with the particle volume fraction when considering disturbances of equal initial energy. These results are explained by considering the reduced amplification of oblique modes in the two-phase flow. The results from these two classical scenarios indicate that, although linear stability analysis shows hardly any

  9. Effect of free-stream turbulence properties on boundary layer laminar-turbulent transition: A new approach

    NASA Astrophysics Data System (ADS)

    Darag, Sakhr A.; Horák, Vladimír

    2012-11-01

    The effect of length scale on flat-plate by-pass transitional boundary layers subject to free stream turbulence intensities ranging from 1.3 to 6.0 percent has been investigated. The analysis is based on the recent experimental and numerical observations into non-equilibrium flows that considering the effect of turbulence properties at the plate leading edge on the transition onset. According to this analysis, physical correlation is developed and incorporated in a conventional boundary layer computer scheme for prediction of transitional flows. The scheme was proposed to calculate the characteristics of the boundary layers under the effect of moderate free-stream turbulence levels by enhancing established integral techniques in conjunction with intermittency weighted model of the transitional boundary layer. To support the results validation, the experimental ERCOFTAC Test Cases T3A, T3B and T3AM for transitional integral parameters have been represented. The results show that the transition location for turbulence level higher than 4% is only a function of turbulence intensity (Tu) and unaffected by significant changes in the length scale (Lx). Whereas for low level of the incoming turbulent flows the transition onset is extremely dependent on FST characteristics, turbulence intensity and integral length scale.

  10. Characteristic Time Scales of Characteristic Magmatic Processes and Systems

    NASA Astrophysics Data System (ADS)

    Marsh, B. D.

    2004-05-01

    Every specific magmatic process, regardless of spatial scale, has an associated characteristic time scale. Time scales associated with crystals alone are rates of growth, dissolution, settling, aggregation, annealing, and nucleation, among others. At the other extreme are the time scales associated with the dynamics of the entire magmatic system. These can be separated into two groups: those associated with system genetics (e.g., the production and transport of magma, establishment of the magmatic system) and those due to physical characteristics of the established system (e.g., wall rock failure, solidification front propagation and instability, porous flow). The detailed geometry of a specific magmatic system is particularly important to appreciate; although generic systems are useful, care must be taken to make model systems as absolutely realistic as possible. Fuzzy models produce fuzzy science. Knowledge of specific time scales is not necessarily useful or meaningful unless the hierarchical context of the time scales for a realistic magmatic system is appreciated. The age of a specific phenocryst or ensemble of phenocrysts, as determined from isotopic or CSD studies, is not meaningful unless something can be ascertained of the provenance of the crystals. For example, crystal size multiplied by growth rate gives a meaningful crystal age only if it is from a part of the system that has experienced semi-monotonic cooling prior to chilling; crystals entrained from a long-standing cumulate bed that were mechanically sorted in ascending magma may not reveal this history. Ragged old crystals rolling about in the system for untold numbers of flushing times record specious process times, telling more about the noise in the system than the life of typical, first generation crystallization processes. The most helpful process-related time scales are those that are known well and that bound or define the temporal style of the system. Perhaps the most valuable of these

  11. Stochastic Modeling of Laminar-Turbulent Transition

    NASA Technical Reports Server (NTRS)

    Rubinstein, Robert; Choudhari, Meelan

    2002-01-01

    Stochastic versions of stability equations are developed in order to develop integrated models of transition and turbulence and to understand the effects of uncertain initial conditions on disturbance growth. Stochastic forms of the resonant triad equations, a high Reynolds number asymptotic theory, and the parabolized stability equations are developed.

  12. Time series diagnosis of tree hydraulic characteristics.

    PubMed

    Phillips, Nathan G; Oren, Ram; Licata, Julian; Linder, Sune

    2004-08-01

    An in vivo method for diagnosing hydraulic characteristics of branches and whole trees is described. The method imposes short-lived perturbations of transpiration and traces the propagation of the hydraulic response through trees. The water uptake response contains the integrated signature of hydraulic resistance and capacitance within trees. The method produces large signal to noise ratios for analysis, but does not cause damage or destruction to tree stems or branches. Based on results with two conifer tree species, we show that the method allows for the simple parameterization of bulk hydraulic resistance and capacitance of trees. Bulk tree parameterization of resistance and capacitance predicted the overall diel shape of water uptake, but did not predict the overshoot water uptake response in trees to shorter-term variations in transpiration, created by step changes in transpiration rate. Stomatal dynamics likely complicated the use of simple resistance-capacitance models of tree water transport on these short time scales. The results provide insight into dominant hydraulic and physiological factors controlling tree water flux on varying time scales, and allow for the practical assessment of necessary tree hydraulic model complexity in relation to the time step of soil- vegetation-atmosphere transport models.

  13. Finite-time Properties of the Navier-Stokes Equations Under Lebesque Space Disturbances

    NASA Astrophysics Data System (ADS)

    Bobba, Kumar

    2006-11-01

    A complete understanding of the stability characteristics of the Navier-Stokes equations involve understanding both the transient response and the steady state response. The steady state (or infinite-time) response of the Navier-Stokes equations is characterized by the point spectrum and has been well studied. In this work, we study the transient (or finite-time) response of the unsteady Navier-Stokes equations linearized about plane Couette base flow under spatial and temporal varying disturbance forcing. The forcing and response are assumed to belong to infinite-dimensional Lebesque function spaces, L2 and L∞. An analytical characterization is given for the induced norms that characterize the response. It is shown that the L2 induced norm is tightly bounded by the H∞ norm of the transfer function operator and the L∞ induced norm is upper bounded by the L1 norm of the impulse response operator. The structure of the worst case disturbances and their amplification rates are computed using spectral methods---with Fourier modes in homogeneous direction and Chebyshev collocation in non-homogeneous direction. The relevance of the present results to the channel flow laminar-turbulent transition experiments will be discussed.

  14. Predicting river travel time from hydraulic characteristics

    USGS Publications Warehouse

    Jobson, H.E.

    2001-01-01

    Predicting the effect of a pollutant spill on downstream water quality is primarily dependent on the water velocity, longitudinal mixing, and chemical/physical reactions. Of these, velocity is the most important and difficult to predict. This paper provides guidance on extrapolating travel-time information from one within bank discharge to another. In many cases, a time series of discharge (such as provided by a U.S. Geological Survey stream gauge) will provide an excellent basis for this extrapolation. Otherwise, the accuracy of a travel time extrapolation based on a resistance equation can be greatly improved by assuming the total flow area is composed of two parts, an active and an inactive area. For 60 reaches of 12 rivers with slopes greater than about 0.0002, travel times could be predicted to within about 10% by computing the active flow area using the Manning equation with n = 0.035 and assuming a constant inactive area for each reach. The predicted travel times were not very sensitive to the assumed values of bed slope or channel width.

  15. Timing Characteristics of Large Area Picosecond Photodetectors

    SciTech Connect

    Adams, Bernhard W.; Elagin, Andrey L.; Frisch, H.; Obaid, Razib; Oberla, E; Vostrikov, Alexander; Wagner, Robert G.; Wang, Jingbo; Wetstein, Matthew J.; Northrop, R

    2015-09-21

    The LAPPD Collaboration was formed to develop ultralast large-area imaging photodetectors based on new methods for fabricating microchannel plates (MCPs). In this paper we characterize the time response using a pulsed, sub picosecond laser. We observe single photoelectron time resolutions of a 20 cm x 20 cm MCP consistently below 70 ps, spatial resolutions of roughly 500 pm, and median gains higher than 10(7). The RMS measured at one particular point on an LAPPD detector is 58 ps, with in of 47 ps. The differential time resolution between the signal reaching the two ends of the delay line anode is measured to be 5.1 ps for large signals, with an asymptotic limit falling below 2 ps as noise-over-signal approaches zero.

  16. Time-Resolved Visualization of Görtler Vortices in a Pulsed Convex Wall Jet using Fast Pressure-Sensitive Paint

    NASA Astrophysics Data System (ADS)

    Gregory, James; Danon, Ron; Greenblatt, David

    2015-11-01

    The time-resolved formation and structure of Görtler vortices in a pulsed convex wall jet are studied in this work. While the presence of Görtler vortices in laminar boundary layers on concave surfaces can be clearly observed, their presence in wall jets flowing over convex surfaces is difficult to discern due to transition to turbulence in the outer part of the jet. This work employed fast-response pressure-sensitive paint (PSP), which has a documented flat frequency response greater than 5 kHz, to visualize the time-resolved formation of the wall jet and the details of the Görtler vortices. The radius of curvature of the wall jet was 8 cm, and the Reynolds number (based on slot height and jet exit velocity) was varied between 5 ×102 and 4 ×104 . The characteristic spanwise wavelength of the vortices was studied as a function of jet Reynolds number. Furthermore, as the Reynolds number was increased, various secondary instabilities were observed that led to laminar-turbulent transition. Funding provided by the U.S. Fulbright Scholar Program.

  17. A real time approach for revising generation unit performance characteristics

    SciTech Connect

    Viviani, G.L.; Lin, C.E.; Webb, M.G.

    1985-02-01

    This paper presents a unique method for representing the performance characteristics of generation units of electric utilities. The approach utilizes digitally sampled information in an on-line enviroment. The resulting accuracy is superior to conventional approaches, as the true time varying nature of performance characteristics is taken into account.

  18. Characteristic times of biased random walks on complex networks.

    PubMed

    Bonaventura, Moreno; Nicosia, Vincenzo; Latora, Vito

    2014-01-01

    We consider degree-biased random walkers whose probability to move from a node to one of its neighbors of degree k is proportional to k(α), where α is a tuning parameter. We study both numerically and analytically three types of characteristic times, namely (i) the time the walker needs to come back to the starting node, (ii) the time it takes to visit a given node for the first time, and (iii) the time it takes to visit all the nodes of the network. We consider a large data set of real-world networks and we show that the value of α which minimizes the three characteristic times differs from the value α(min)=-1 analytically found for uncorrelated networks in the mean-field approximation. In addition to this, we found that assortative networks have preferentially a value of α(min) in the range [-1,-0.5], while disassortative networks have α(min) in the range [-0.5,0]. We derive an analytical relation between the degree correlation exponent ν and the optimal bias value α(min), which works well for real-world assortative networks. When only local information is available, degree-biased random walks can guarantee smaller characteristic times than the classical unbiased random walks by means of an appropriate tuning of the motion bias.

  19. Using time domain characteristics to discriminate physiologic and parkinsonian tremors.

    PubMed

    Edwards, R; Beuter, A

    2000-01-01

    Tremor amplitude and frequency do not always clearly differentiate subjects with particular pathologies from control subjects or from subjects with other pathologies, especially in early stages of a disease. For patients with early stages of Parkinson's disease (PD) the discriminative power of amplitude was compared with that of other time domain characteristics of tremor recordings that are probably not evident clinically. Postural tremor with and without visual feedback and rest tremor were recorded in both hands of a group of patients with Parkinson's disease (n = 21) and a group of healthy control subjects (n = 30) using displacement lasers. Velocity and acceleration data were derived from displacement data. Twelve time domain characteristics were calculated on each recording and the discriminating power of each was evaluated using the worse hand in each case. Postural tremor with no visual feedback separates the two groups of subjects most efficiently, especially in velocity and acceleration. Tremor in Parkinson's disease (in comparison to normal physiologic tremor) has a specific morphology, has a distinctive histogram, is more periodic, and contains indications of nonlinearity in the underlying dynamics. There may also be greater difference in amplitude between the two hands and time asymmetry in tremor of patients with PD. A series of finger flexions seems to enhance normal tremor but not tremor in PD and may thus aid in discrimination. Discrimination of tremor attributable to PD from normal physiologic tremor can be enhanced by measuring time domain characteristics subtler than amplitude, particularly when amplitude itself is not large. Tremor measurement should not be limited to acceleration data because some information is more visible in other variables.

  20. A time-dependent neutron transport method of characteristics formulation with time derivative propagation

    NASA Astrophysics Data System (ADS)

    Hoffman, Adam J.; Lee, John C.

    2016-02-01

    A new time-dependent Method of Characteristics (MOC) formulation for nuclear reactor kinetics was developed utilizing angular flux time-derivative propagation. This method avoids the requirement of storing the angular flux at previous points in time to represent a discretized time derivative; instead, an equation for the angular flux time derivative along 1D spatial characteristics is derived and solved concurrently with the 1D transport characteristic equation. This approach allows the angular flux time derivative to be recast principally in terms of the neutron source time derivatives, which are approximated to high-order accuracy using the backward differentiation formula (BDF). This approach, called Source Derivative Propagation (SDP), drastically reduces the memory requirements of time-dependent MOC relative to methods that require storing the angular flux. An SDP method was developed for 2D and 3D applications and implemented in the computer code DeCART in 2D. DeCART was used to model two reactor transient benchmarks: a modified TWIGL problem and a C5G7 transient. The SDP method accurately and efficiently replicated the solution of the conventional time-dependent MOC method using two orders of magnitude less memory.

  1. A time-dependent neutron transport method of characteristics formulation with time derivative propagation

    SciTech Connect

    Hoffman, Adam J. Lee, John C.

    2016-02-15

    A new time-dependent Method of Characteristics (MOC) formulation for nuclear reactor kinetics was developed utilizing angular flux time-derivative propagation. This method avoids the requirement of storing the angular flux at previous points in time to represent a discretized time derivative; instead, an equation for the angular flux time derivative along 1D spatial characteristics is derived and solved concurrently with the 1D transport characteristic equation. This approach allows the angular flux time derivative to be recast principally in terms of the neutron source time derivatives, which are approximated to high-order accuracy using the backward differentiation formula (BDF). This approach, called Source Derivative Propagation (SDP), drastically reduces the memory requirements of time-dependent MOC relative to methods that require storing the angular flux. An SDP method was developed for 2D and 3D applications and implemented in the computer code DeCART in 2D. DeCART was used to model two reactor transient benchmarks: a modified TWIGL problem and a C5G7 transient. The SDP method accurately and efficiently replicated the solution of the conventional time-dependent MOC method using two orders of magnitude less memory.

  2. Continuous-Time Finance and the Waiting Time Distribution: Multiple Characteristic Times

    NASA Astrophysics Data System (ADS)

    Fa, Kwok Sau

    2012-09-01

    In this paper, we model the tick-by-tick dynamics of markets by using the continuous-time random walk (CTRW) model. We employ a sum of products of power law and stretched exponential functions for the waiting time probability distribution function; this function can fit well the waiting time distribution for BUND futures traded at LIFFE in 1997.

  3. Fractional characteristic times and dissipated energy in fractional linear viscoelasticity

    NASA Astrophysics Data System (ADS)

    Colinas-Armijo, Natalia; Di Paola, Mario; Pinnola, Francesco P.

    2016-08-01

    In fractional viscoelasticity the stress-strain relation is a differential equation with non-integer operators (derivative or integral). Such constitutive law is able to describe the mechanical behavior of several materials, but when fractional operators appear, the elastic and the viscous contribution are inseparable and the characteristic times (relaxation and retardation time) cannot be defined. This paper aims to provide an approach to separate the elastic and the viscous phase in the fractional stress-strain relation with the aid of an equivalent classical model (Kelvin-Voigt or Maxwell). For such equivalent model the parameters are selected by an optimization procedure. Once the parameters of the equivalent model are defined, characteristic times of fractional viscoelasticity are readily defined as ratio between viscosity and stiffness. In the numerical applications, three kinds of different excitations are considered, that is, harmonic, periodic, and pseudo-stochastic. It is shown that, for any periodic excitation, the equivalent models have some important features: (i) the dissipated energy per cycle at steady-state coincides with the Staverman-Schwarzl formulation of the fractional model, (ii) the elastic and the viscous coefficients of the equivalent model are strictly related to the storage and the loss modulus, respectively.

  4. Remaining time and opportunities at work: Relationships between age, work characteristics, and occupational future time perspective.

    PubMed

    Zacher, Hannes; Frese, Michael

    2009-06-01

    The authors adapted the concept of future time perspective (FTP) to the work context and examined its relationships with age and work characteristics (job complexity and control). Structural equation modeling of data from 176 employees of various occupations showed that age is negatively related to 2 distinct dimensions of occupational FTP: remaining time and remaining opportunities. Work characteristics (job complexity and control) were positively related to remaining opportunities and moderated the relationship between age and remaining opportunities, such that the relationship became weaker with increasing levels of job complexity and control.

  5. Demographic characteristics of full-time emergency physicians in Canada.

    PubMed

    Lloyd, S; Streiner, D; Shannon, S

    1993-07-01

    The objective of this study was to describe individual and practice characteristics of Canadian emergency physicians, and to determine if these characteristics varied with geographic region, type of certification, or method of reimbursement. The study took place in emergency departments across Canada, and all full-time physicians with certification in emergency medicine, and a random sample of Canadian Association of Emergency Physician members without certification were surveyed with a 23-item questionnaire. Descriptive statistics on individual and practice characteristics were outcome measures. Comparative statistics evaluating demographic characteristics by region, type of certification, and method of reimbursement were used. There were significant differences between responders and nonresponders based on certification (P < .001) and region of residence (P < .005). Most physicians are male (87.3%), married (83.3%), reimbursed on a fee for service basis (61%), work in teaching hospitals (65.8%), and participate in medical education (82.3%). On average physicians are 38 years of age, work of 14 shifts/month, 9 hours/shift, 11 nonclinical emergency related hours/week, and have 5 vacation weeks/year. More physicians with FRCP(EM) certification work in teaching hospitals (P < .00001), do nonclinical emergency related work (P < .0001), participate in medical education (P < .0001), and are involved in research (P < .001). There are significant differences by geographic region in gross annual salary (P < .00001), method of reimbursement (P < .00001), and independent hospital emergency department status (P < .00001). Fee-for-service reimbursement for clinical service provides a higher gross annual income than other methods (P = .028). Emergency medicine is an emerging clinical discipline with a strong academic focus.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Real-Time Mapping alert system; characteristics and capabilities

    USGS Publications Warehouse

    Torres, L.A.; Lambert, S.C.; Liebermann, T.D.

    1995-01-01

    The U.S. Geological Survey has an extensive hydrologic network that records and transmits precipitation, stage, discharge, and other water-related data on a real-time basis to an automated data processing system. Data values are recorded on electronic data collection platforms at field sampling sites. These values are transmitted by means of orbiting satellites to receiving ground stations, and by way of telecommunication lines to a U.S. Geological Survey office where they are processed on a computer system. Data that exceed predefined thresholds are identified as alert values. The current alert status at monitoring sites within a state or region is of critical importance during floods, hurricanes, and other extreme hydrologic events. This report describes the characteristics and capabilities of a series of computer programs for real-time mapping of hydrologic data. The software provides interactive graphics display and query of hydrologic information from the network in a real-time, map-based, menu-driven environment.

  7. Relationship between force-time and velocity-time characteristics of dynamic and isometric muscle actions.

    PubMed

    Khamoui, Andy V; Brown, Lee E; Nguyen, Diamond; Uribe, Brandon P; Coburn, Jared W; Noffal, Guillermo J; Tran, Tai

    2011-01-01

    Previous research has investigated the force-time curve characteristics of isometric and dynamic muscle actions; however, few studies have addressed their relationship to dynamic exercise velocity-time variables. The purpose of this study was to investigate relationships between velocity-time characteristics (high pull and vertical jump peak velocity and rate of velocity development [HPPV, HPRVD, VJPV, VJRVD]), force-time characteristics (isometric peak force [IsoPF], body mass adjusted isometric peak force [IsoPF/BM], isometric rate of force development at different millisecond windows [IsoRFD50-250], dynamic peak force [HPPF], body mass adjusted dynamic peak force [HPPF/BM]), and vertical jump height (VJHeight). Nineteen recreationally trained men (age 23.89 ± 2.92 yr; height 176.32 ± 7.06 cm; mass 78.76 ± 16.50 kg) completed 2 testing sessions. The first session consisted of 3 isometric mid-thigh pulls on a force plate with each repetition held for 3 seconds. On the second testing session, subjects completed 3 dynamic mid-thigh high pulls with 30% IsoPF followed by 3 vertical jumps on a force plate. The HPRVD correlated with IsoRFD50 (r = 0.52) and IsoRFD100 (r = 0.49). The HPPV correlated with IsoPF/BM (r = -0.60), IsoRFD50 (r = 0.56), and IsoRFD100 (r = 0.56). The VJHeight correlated with IsoPF/BM (r = 0.61), whereas VJPV correlated with IsoPF/BM (r = 0.62). These correlations suggest that explosive isometric force production within 50 to 100 milliseconds may influence the ability to accelerate an implement or body and attain high velocity, albeit in a moderate fashion. In addition, body mass adjusted strength may positively influence vertical jump parameters.

  8. Measurements of Pilot Time Delay as Influenced by Controller Characteristics and Vehicles Time Delays

    NASA Technical Reports Server (NTRS)

    Privoznik, C. M.; Berry, D. T.; Bartoli, A. G.

    1984-01-01

    A study to measure and compare pilot time delay when using a space shuttle rotational hand controller and a more conventional control stick was conducted at NASA Ames Research Center's Dryden Flight Research Facility. The space shuttle controller has a palm pivot in the pitch axis. The more conventional controller used was a general-purpose engineering simulator stick that has a pivot length between that of a typical aircraft center stick and a sidestick. Measurements of the pilot's effective time delay were obtained through a first-order, closed-loop, compensatory tracking task in pitch. The tasks were implemented through a space shuttle cockpit simulator and a critical task tester device. The study consisted of 450 data runs with four test pilots and one nonpilot, and used three control stick configurations and two system delays. Results showed that the heavier conventional stick had the lowest pilot effective time delays associated with it, whereas the shuttle and light conventional sticks each had similar higher pilot time delay characteristics. It was also determined that each control stick showed an increase in pilot time delay when the total system delay was increased.

  9. Student Part-Time Employment: Characteristics and Consequences

    ERIC Educational Resources Information Center

    Robotham, David

    2012-01-01

    Purpose: The aim of the paper is to examine the consequences of students engaging in part-time employment during their studies. It reports the results of a survey of part-time employment among university students. The research examined the possible consequences of combining part-time employment with full-time study, with particular reference to…

  10. Maternal Mental Health, Neighborhood Characteristics, and Time Investments in Children

    ERIC Educational Resources Information Center

    Frech, Adrianne; Kimbro, Rachel Tolbert

    2011-01-01

    We use data from the Fragile Families and Child Wellbeing Study (N = 3,572) to examine relationships between maternal depression and mothers' time investments with their 5-year-old children in outings, trips to playgrounds or parks, time spent reading with the child, and time spent playing indoors with the child. We also examine whether mothers'…

  11. Estimating Testing Time: The Effects of Item Characteristics on Response Latency.

    ERIC Educational Resources Information Center

    Halkitis, Perry N.; And Others

    The relationship between test item characteristics and testing time was studied for a computer-administered licensing examination. One objective of the study was to develop a model to predict testing time on the basis of known item characteristics. Response latencies (i.e., the amount of time taken by examinees to read, review, and answer items)…

  12. Spectral characteristics of time resolved magnonic spin Seebeck effect

    NASA Astrophysics Data System (ADS)

    Etesami, S. R.; Chotorlishvili, L.; Berakdar, J.

    2015-09-01

    Spin Seebeck effect (SSE) holds promise for new spintronic devices with low-energy consumption. The underlying physics, essential for a further progress, is yet to be fully clarified. This study of the time resolved longitudinal SSE in the magnetic insulator yttrium iron garnet concludes that a substantial contribution to the spin current stems from small wave-vector subthermal exchange magnons. Our finding is in line with the recent experiment by S. R. Boona and J. P. Heremans [Phys. Rev. B 90, 064421 (2014)]. Technically, the spin-current dynamics is treated based on the Landau-Lifshitz-Gilbert equation also including magnons back-action on thermal bath, while the formation of the time dependent thermal gradient is described self-consistently via the heat equation coupled to the magnetization dynamics.

  13. Spectral characteristics of time resolved magnonic spin Seebeck effect

    SciTech Connect

    Etesami, S. R.; Chotorlishvili, L.; Berakdar, J.

    2015-09-28

    Spin Seebeck effect (SSE) holds promise for new spintronic devices with low-energy consumption. The underlying physics, essential for a further progress, is yet to be fully clarified. This study of the time resolved longitudinal SSE in the magnetic insulator yttrium iron garnet concludes that a substantial contribution to the spin current stems from small wave-vector subthermal exchange magnons. Our finding is in line with the recent experiment by S. R. Boona and J. P. Heremans [Phys. Rev. B 90, 064421 (2014)]. Technically, the spin-current dynamics is treated based on the Landau-Lifshitz-Gilbert equation also including magnons back-action on thermal bath, while the formation of the time dependent thermal gradient is described self-consistently via the heat equation coupled to the magnetization dynamics.

  14. Characteristic Based Methods for the Time-Domain Maxwell Equations

    DTIC Science & Technology

    1993-08-09

    2-D results on Cartesian frame demonstrated a potential for numerical efficiency improvement. 14. SUBJECT TERMS 15. NUMBER OF PAGES Time-domain...11 4 Discussion of Numerical Results ........................ 19 5 C onclusion...l ill tiit, pruIcIt a1lyis lder this’ Iranirwurk. Ilulilerical results it’lect tfi heIcst puss,’ibk 1)1(2pefon~lI liace of t he iiew aiiuiirical j

  15. Relaxation Characteristics of 828 DGEBA Epoxy Over Long Time Periods

    NASA Astrophysics Data System (ADS)

    Hoo, Jasmine; Reprogle, Riley C.; Wisler, Brian; Arechederra, Gabriel K.; McCoy, John D.; Kropka, Jamie M.; Long, Kevin N.

    The mechanical relaxation response in uniaxial compression of a diglycidyl ether of bisphenol-A epoxy was studied over long time periods. The epoxy, 828DEA, was Epon 828 cured with diethanolamine (DEA). A sample was compressed at constant strain rate and held at various strain levels for days to allow the sample to relax. The sample was then compressed further and held once more. The relaxation curves were fit with a stretched exponential function. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  16. Inverting Source Time Functions to determine the fault kinematic characteristics

    NASA Astrophysics Data System (ADS)

    Toraldo Serra, E. M.; Orefice, A.; Emolo, A.; Zollo, A.

    2012-04-01

    In seismology, the analisys of source kinematic parameters (slip-rate and rupture velocity ecc.) is a fundamental way to study the time-history of the rupture process that occurs during a seismic event. To this end various method to reconstruct source kinematics models from the inversion of seismogram have been proposed during the time. In this work we present an alternative methodology to infer source models. We aim, indeed, at obtaining the slip and rupture velocity distribution on the fault plane inverting the apparent Source Time Functions (STFs). This kind of analysis, rather than a classical inversion based on a direct study of seismograms recorded at various stations, may have several advantages. A major advantage is related to the possibility to overcome in the forward modeling any problem related to the computation of the Green's function, as the choice of the correct and reliable propagation model. To retrieve reliable STF, we apply the stabilized deconvolution technique proposed by Vallée [2004]. Based on Empirical Green's Functions (EGF) approach, this technique integrates in the deconvolution process four physical constraints on the STFs, that are causality, positivity, limited duration, and equal area. In any case the EGF approach suffers from certain limitations related to the selection of valuable Empirical Green Function, especially for small events. The approach used to invert the STFs is based on the technique of Emolo and Zollo [2005] to invert strong-motion data. In particular, the slip and the rupture velocity values are specified only at a set of control-points on the fault plane and their distributions on the whole fault are then obtained by a bicubic interpolation. The final slip and rupture velocity values at the fault-grid nodes are then determined by searching for the maximum of a fitness function (based of comparison between real and synthetic STFs) by using the Genetic Algorithm. The number of control-points is progressively increased

  17. Characteristic time for halo current growth and rotation

    SciTech Connect

    Boozer, Allen H.

    2015-10-15

    A halo current flows for part of its path through the plasma edge and for part through the chamber walls and during tokamak disruptions can be as large as tenths of the plasma current. The primary interest in halo currents is the large force that they can exert on machine components particularly if the toriodal rotation of the halo current resonates with a natural oscillation frequency of the tokamak device. Halo currents arise when required to slow down the growth of a kink that is too unstable to be stabilized by the chamber walls. The width of the current channel in the halo plasma is comparable to the amplitude of the kink, and the halo current grows linearly, not exponentially, in time. The current density in the halo is comparable to that of the main plasma body. The rocket force due to plasma flowing out of the halo and recombining on the chamber walls can cause the non-axisymmetric magnetic structure produced by the kink to rotate toroidally at a speed comparable to the halo speed of sound. Gerhardt's observations of the halo current in NSTX shot 141 687 [Nucl. Fusion 53, 023005 (2013)] illustrate many features of the theory of halo currents and are discussed as a summary of the theory.

  18. General formulation of characteristic time for persistent chemicals in a multimedia environment

    SciTech Connect

    Bennett, D.H.; McKone, T.E. |; Kastenberg, W.E.

    1999-02-01

    A simple yet representative method for determining the characteristic time a persistent organic pollutant remains in a multimedia environment is presented. The characteristic time is an important attribute for assessing long-term health and ecological impacts of a chemical. Calculating the characteristic time requires information on decay rates in multiple environmental media as well as the proportion of mass in each environmental medium. The authors explore the premise that using a steady-state distribution of the mass in the environment provides a means to calculate a representative estimate of the characteristic time while maintaining a simple formulation. Calculating the steady-state mass distribution incorporates the effect of advective transport and nonequilibrium effects resulting from the source terms. Using several chemicals, they calculate and compare the characteristic time in a representative multimedia environment for dynamic, steady-state, and equilibrium multimedia models, and also for a single medium model. They demonstrate that formulating the characteristic time based on the steady-state mass distribution in the environment closely approximates the dynamic characteristic time for a range of chemicals and thus can be used in decisions regarding chemical use in the environment.

  19. Classification of biosensor time series using dynamic time warping: applications in screening cancer cells with characteristic biomarkers.

    PubMed

    Rai, Shesh N; Trainor, Patrick J; Khosravi, Farhad; Kloecker, Goetz; Panchapakesan, Balaji

    2016-01-01

    The development of biosensors that produce time series data will facilitate improvements in biomedical diagnostics and in personalized medicine. The time series produced by these devices often contains characteristic features arising from biochemical interactions between the sample and the sensor. To use such characteristic features for determining sample class, similarity-based classifiers can be utilized. However, the construction of such classifiers is complicated by the variability in the time domains of such series that renders the traditional distance metrics such as Euclidean distance ineffective in distinguishing between biological variance and time domain variance. The dynamic time warping (DTW) algorithm is a sequence alignment algorithm that can be used to align two or more series to facilitate quantifying similarity. In this article, we evaluated the performance of DTW distance-based similarity classifiers for classifying time series that mimics electrical signals produced by nanotube biosensors. Simulation studies demonstrated the positive performance of such classifiers in discriminating between time series containing characteristic features that are obscured by noise in the intensity and time domains. We then applied a DTW distance-based k-nearest neighbors classifier to distinguish the presence/absence of mesenchymal biomarker in cancer cells in buffy coats in a blinded test. Using a train-test approach, we find that the classifier had high sensitivity (90.9%) and specificity (81.8%) in differentiating between EpCAM-positive MCF7 cells spiked in buffy coats and those in plain buffy coats.

  20. An Analysis of Institutional Characteristics That Contribute to Extended Time to Doctoral Degree

    ERIC Educational Resources Information Center

    Frasier, Helen Schurke

    2013-01-01

    Many factors--individual, departmental and institutional--have been associated with longer time to degree and progress toward degree completion. Lengthy time to degree affects the availability of resources, advising, persistence, and degree completion. This research identified institutional characteristics that impacted extended time to degree,…

  1. Super-resolution infrared time measurement method based on target dynamic characteristics

    NASA Astrophysics Data System (ADS)

    Li, Bin; Hu, Qiuping; Tang, Zili; Zhang, Sanxi; Zhang, Hua; Yue, Peng; Liu, Biao

    2016-10-01

    High precision time control in the use of weapons and equipment is an important part of product design and development. In order to satisfy the data acquisition requirement of high accuracy and reliability in the rapid flight process, the super-resolution time measurement method based on target dynamic characteristics was put forward and proved by the cabin opening time measurement experiment. First, the changes of explosion pressure wave and image in the cabin opening process were analyzed in detail. The change regulation of explosion flame shape was analyzed by the characteristics of typical pressure wave, and then the high frequency images of the explosion process were shot by high speed camera. The change regulation of the infrared image was obtained through the comparison of visible and infrared image mechanism. Then, combined with the target motion features, and the observed station parameters, the observation model of movement process was built. On the basis of the above research, the infrared characteristic and the movement characteristic were transformed, and the super resolution model was established. For test method, combined with the actual class time measuring process in experimental design, to obtain the special radar for measuring high precision open class time as the true value of the precision appraisal. Experimental results show that the infrared feature and motion feature can realize open class time super resolution measurement, can effectively improve the accuracy and reliability of the data, to achieve specific action of high accuracy measurement that plays an important role by making use of the target dynamic characteristics.

  2. The Impact of Item Format and Examinee Characteristics on Response Times

    ERIC Educational Resources Information Center

    Hess, Brian J.; Johnston, Mary M.; Lipner, Rebecca S.

    2013-01-01

    Current research on examination response time has focused on tests comprised of traditional multiple-choice items. Consequently, the impact of other innovative or complex item formats on examinee response time is not understood. The present study used multilevel growth modeling to investigate examinee characteristics associated with response time…

  3. Characteristics of electricity generation with intermittent sources depending on the time resolution of the input data

    NASA Astrophysics Data System (ADS)

    Wagner, F.; Wertz, F.

    2016-08-01

    Data on the electricity supply with intermittent renewable sources are made public by the Transmission System Operators (TSO) and other sources. Data are typically provided in 1h increments. In this paper, we analyse wind and photo-voltaic data from the Czech Republic. The analysis concentrates on major characteristics of a supply situation where the annual demand is formally met by scaled-up wind and photovoltaic power. The original data are supplied in 1min increments and successively averaged up to 1h time resolution. This paper focuses on the dependence of the major supply characteristics on the time resolution of the available electricity data.

  4. Time Characteristics and Odd-Even Effects in Nucleus Deexcitation Process

    SciTech Connect

    Fotina, O.V.; Drozdov, V.A.; Eremenko, D.O.; Platonov, S.Yu.; Yuminov, O.A.

    2004-10-01

    An approach based on the statistical theory of nuclear reactions and Monte Carlo method is used for evaluations of excited nuclear system characteristics like probability of decay channel (light particle, {gamma}-quanta emission, or fission), energy, emission angle of decay products, and time characteristics of deexcitation processes. This method permits the direct simulation of the experimental situation, in particular, nuclear-lifetime measurements by the crystal blocking technique. Decay times of compound nuclei formed in the fusion reactions {sup 12}C + {sup 28}Si {yields} {sup 40}Ca and {sup 19}F + {sup 28}Si {yields} {sup 47}V are estimated.

  5. Characteristic time scales in the American dollar-Mexican peso exchange currency market

    NASA Astrophysics Data System (ADS)

    Alvarez-Ramirez, Jose

    2002-06-01

    Daily fluctuations of the American dollar-Mexican peso exchange currency market are studied using multifractal analysis methods. It is found evidence of multiaffinity of daily fluctuations in the sense that the qth-order (roughness) Hurst exponent Hq varies with changes in q. It is also found that there exist several characteristic time scales ranging from week to year. Accordingly, the market exhibits persistence in the sense that instabilities introduced by market events acting around the characteristic time scales (mainly, quarter and year) would propagate through the future market activity. Some implications of our results on the regulation of the dollar-mexpeso market activity are discussed.

  6. Time to Degree: Students' Abilities, University Characteristics or Something Else? Evidence from Italy

    ERIC Educational Resources Information Center

    Aina, Carmen; Baici, Eliana; Casalone, Giorgia

    2011-01-01

    We use a representative sample of Italian graduates drawn from the Consorzio AlmaLaurea to assess the impact of individual and family characteristics, university inputs and the labour market on the time taken to attain a degree. Our estimates highlight that all these dimensions drive the outcome analysed. Weak labour market prospects contribute…

  7. Role of Text and Student Characteristics in Real-Time Reading Processes across the Primary Grades

    ERIC Educational Resources Information Center

    de Leeuw, Linda; Segers, Eliane; Verhoeven, Ludo

    2016-01-01

    Although much is known about beginning readers using behavioural measures, real-time processes are still less clear. The present study examined eye movements (skipping rate, gaze, look back and second-pass duration) as a function of text-related (difficulty and word class) and student-related characteristics (word decoding, reading comprehension,…

  8. Curriculum Characteristics of Time-Compressed Course in a U.S. Higher Education Institution

    ERIC Educational Resources Information Center

    Hyun, Eunsook; Kretovics, Mark; Crowe, Alicia

    2006-01-01

    The study explored characteristics of the curriculum practice of higher education faculty in the context of time-compressed (e.g., 5-6 weeks) courses as compared with regular term (15-16 weeks) courses. The researchers used open-ended questions on a web-based survey at a large doctoral-extensive university in a Midwestern state in the United…

  9. Force-Time Characteristics and Running Velocity of Male Sprinters During the Acceleration Phase of Sprinting.

    ERIC Educational Resources Information Center

    Mero, Antti

    1988-01-01

    Investigation of the force-time characteristics of eight male sprinters during the acceleration phase of the sprint start suggested that the braking and propulsion phases occur immediately after the block phase and that muscle strength strongly affects running velocity in the sprint start. (Author/CB)

  10. Characteristics of the transmission of autoregressive sub-patterns in financial time series

    NASA Astrophysics Data System (ADS)

    Gao, Xiangyun; An, Haizhong; Fang, Wei; Huang, Xuan; Li, Huajiao; Zhong, Weiqiong

    2014-09-01

    There are many types of autoregressive patterns in financial time series, and they form a transmission process. Here, we define autoregressive patterns quantitatively through an econometrical regression model. We present a computational algorithm that sets the autoregressive patterns as nodes and transmissions between patterns as edges, and then converts the transmission process of autoregressive patterns in a time series into a network. We utilised daily Shanghai (securities) composite index time series to study the transmission characteristics of autoregressive patterns. We found statistically significant evidence that the financial market is not random and that there are similar characteristics between parts and whole time series. A few types of autoregressive sub-patterns and transmission patterns drive the oscillations of the financial market. A clustering effect on fluctuations appears in the transmission process, and certain non-major autoregressive sub-patterns have high media capabilities in the financial time series. Different stock indexes exhibit similar characteristics in the transmission of fluctuation information. This work not only proposes a distinctive perspective for analysing financial time series but also provides important information for investors.

  11. Characteristics of the transmission of autoregressive sub-patterns in financial time series.

    PubMed

    Gao, Xiangyun; An, Haizhong; Fang, Wei; Huang, Xuan; Li, Huajiao; Zhong, Weiqiong

    2014-09-05

    There are many types of autoregressive patterns in financial time series, and they form a transmission process. Here, we define autoregressive patterns quantitatively through an econometrical regression model. We present a computational algorithm that sets the autoregressive patterns as nodes and transmissions between patterns as edges, and then converts the transmission process of autoregressive patterns in a time series into a network. We utilised daily Shanghai (securities) composite index time series to study the transmission characteristics of autoregressive patterns. We found statistically significant evidence that the financial market is not random and that there are similar characteristics between parts and whole time series. A few types of autoregressive sub-patterns and transmission patterns drive the oscillations of the financial market. A clustering effect on fluctuations appears in the transmission process, and certain non-major autoregressive sub-patterns have high media capabilities in the financial time series. Different stock indexes exhibit similar characteristics in the transmission of fluctuation information. This work not only proposes a distinctive perspective for analysing financial time series but also provides important information for investors.

  12. The Dependence of Characteristic Times of Gradual SEP Events on Their Associated CME Properties

    NASA Astrophysics Data System (ADS)

    Pan, Z. H.; Wang, C. B.; Xue, X. H.; Wang, Y. M.

    It is generally believed that coronal mass ejections CMEs are the drivers of shocks that accelerate gradual solar energetic particles SEPs One might expect that the characteristics of the SEP intensity time profiles observed at 1 AU are determined by properties of the associated CMEs such as the radial speed and the angular width Recently Kahler statistically investigated the characteristic times of gradual SEP events observed from 1998-2002 and their associated coronal mass ejection properties Astrophys J 628 1014--1022 2005 Three characteristic times of gradual SEP events are determined as functions of solar source longitude 1 T 0 the time from associated CME launch to SEP onset at 1 AU 2 T R the rise time from SEP onset to the time when the SEP intensity is a factor of 2 below peak intensity and 3 T D the duration over which the SEP intensity is within a factor of 2 of the peak intensity However in his study the CME speeds and angular widths are directly taken from the LASCO CME catalog In this study we analyze the radial speeds and the angular widths of CMEs by an ice-cream cone model and re-investigate their correlationships with the characteristic times of the corresponding SEP events We find T R and T D are significantly correlated with radial speed for SEP events in the best-connected longitude range and there is no correlation between T 0 and CME radial speed and angular width which is consistent with Kahler s results On the other hand it s found that T R and T D are also have

  13. Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions

    NASA Astrophysics Data System (ADS)

    Lin, Aijing; Liu, Kang K. L.; Bartsch, Ronny P.; Ivanov, Plamen Ch.

    2016-05-01

    Within the framework of `Network Physiology', we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain-heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain-heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems.

  14. The influence of travel time on breast cancer characteristics, receipt of primary therapy, and surveillance mammography.

    PubMed

    Onega, Tracy; Cook, Andrea; Kirlin, Beth; Shi, Xun; Alford-Teaster, Jennifer; Tuzzio, Leah; Buist, Diana S M

    2011-08-01

    Travel time has been shown to influence some aspects of cancer characteristics at diagnosis and care for women with breast cancer, but important gaps remain in our understanding of its impact. We examined the influence of travel time to the nearest radiology facility on breast cancer characteristics, treatment, and surveillance for women with early-stage invasive breast cancer. We included 1,012 women with invasive breast cancer (stages I and II) who had access to care within an integrated health care delivery system in western Washington State. The travel times to the nearest radiology facility were calculated for all the U.S. Census blocks within the study area and assigned to women based on residence at diagnosis. We collected cancer characteristics, primary and adjuvant therapies, and surveillance mammography for at least 2.5 years post diagnosis and used multivariable analyses to test the associations of travel time. The majority of women (68.6%) lived within 20 min of the nearest radiology facility, had stage I disease (72.7%), received breast conserving therapy (68.7%), and had annual surveillance mammography the first 2 years after treatment (73.7%). The travel time was not significantly associated with the stage or surveillance mammography after adjusting for covariates. Primary therapy was significantly related to travel time, with greater travel time (>30 min vs. ≤ 10 min) associated with a higher likelihood of mastectomy compared to breast conserving surgery (RR = 1.53; 95% CI, 1.16-2.01). The travel time was not associated with the stage at diagnosis or surveillance mammography receipt. The travel time does seem to influence the type of primary therapy among women with breast cancer, suggesting that women may prefer low frequency services, such as mastectomy, if geographic access to a radiology facility is limited.

  15. Characteristic Time of the Magnetospheric Ring Current Decay FROM EXPIREMENT AND THEORY

    NASA Astrophysics Data System (ADS)

    Biktash(Sizova), L. Z.; Korotova, G. I.

    2006-12-01

    The magnetospheric ring current particles are the most dynamic part of the Earth's radiation belts especially during geomagnetic storms. The processes of the magnetospheric ring current decay are studied as a function of the solar wind electric field. It is shown that the ring current dissipation rate is different during the main and recovery phase of geomagnetic storms. The characteristic time of the ring current decay in the main phase is independent of storm intensity and equals 4 hours. The characteristic time of the ring current decay in a recovery phase increases with storm intensity. We examine the ring current ion lifetimes for the possible mechanisms of its decay. Coulomb scattering, charge exchange and plasma instability mechanisms are used for estimation of lifetime of electrons, protons, helium, and oxygen ions. The values of the characteristic lifetime of ring current dissipation obtained from experiment and theory are compared. It is shown that during main and recovery phase of magnetic storm the different mechanisms can play main role in dissipation of the ring current. Very short characteristic decay time during main phase of geomagnetic storms is associated with plasma instabilities. The available ion composition data of the ring current make possible to assume that the ring current decay is accounted for by ion composition variations with changing the intensity (and hence position) of the ring current and/or by a rise of energetic ion fraction on low L-shells.

  16. Learning characteristics of a space-time neural network as a tether skiprope observer

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

    1992-01-01

    The Software Technology Laboratory at JSC is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

  17. Learning characteristics of a space-time neural network as a tether skiprope observer

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

    1993-01-01

    The Software Technology Laboratory at the Johnson Space Center is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

  18. Modified timing characteristic of a scintillation detection system with photonic crystal structures.

    PubMed

    Liu, Jinliang; Liu, Bo; Zhu, Zhichao; Chen, Liang; Hu, Jing; Xu, Mengxuan; Cheng, Chuanwei; Ouyang, Xiaoping; Zhang, Zhongbing; Ruan, Jinlu; He, Shiyi; Liu, Linyue; Gu, Mu; Chen, Hong

    2017-03-01

    It is intuitively expected that an enhanced light extraction of a scintillator can be easily achieved by photonic crystal structures. Here, we demonstrate a modified timing characteristic for a detection system induced by enhanced light extraction with photonic crystal structures. Such improvement is due to the enhanced light extraction which can be clearly proven by the independent measurements of the light output and the timing resolution. The present investigation is advantageous to promote the development of a scintillation detection system performance based on the time-of-flight measurement.

  19. Time-Varying Multifractal Characteristics and Formation Mechanism of Loaded Coal Electromagnetic Radiation

    NASA Astrophysics Data System (ADS)

    Hu, Shaobin; Wang, Enyuan; Li, Zhonghui; Shen, Rongxi; Liu, Jie

    2014-09-01

    Dynamic collapses of deeply mined coal rocks are severe threats to miners. To predict the collapses more accurately using electromagnetic radiation (EMR), we investigate the time-varying multifractal characteristics and formation mechanism of EMR induced by underground coal mining. A series of uniaxial compression and multi-stage loading experiments with coal samples of different mechanical properties were carried out. The EMR signals during their damage evolution were monitored in real-time; the inherent law of EMR time series was analyzed by fractal theory. The results show that the time-varying multifractal characteristics of EMR are determined by damage evolutions process, the dissipated energy caused by damage evolutions such as crack propagation, fractal sliding and shearing can be regard as the fingerprint of various EMR micro-mechanics. Based on the Irreversible thermodynamics and damage mechanics, we introduced the damage internal variable, constructed the dissipative potential function and established the coupled model of the EMR and the dissipative energy, which revealed the nature of dynamic nonlinear characteristics of EMR. Dynamic multifractal spectrum is the objective response of EMR signals, thus it can be used to evaluate the coal deformation and fracture process.

  20. Analysis of the kinetics of lipid peroxidation in terms of characteristic time-points.

    PubMed

    Pinchuk, Ilya; Lichtenberg, Dov

    2014-02-01

    Measuring peroxidation of aggregated lipids in model systems (liposomes, micelles, emulsions or microemulsions) as well as in samples of biological origin ex vivo (isolated lipoproteins, blood sera or plasma) is widely used in medical and biological investigations, to evaluate the oxidative stress, antioxidants' efficiency and lipid oxidizability in different pathophysiological states. To avoid possible artifacts, such investigations must be based on the time course of peroxidation (i.e. on kinetic studies). To be able to compare complex kinetic profiles, it is important to characterize them in terms of mechanistically meaningful and experimentally unequivocal parameters. In this review, we characterize the typically observed continuous kinetic profiles in terms of a limited number of characteristic time-points (both commonly used and additional time-points and their combinations) that can be derived from experimental time-dependencies. The meaning of each of the experimentally observed characteristic parameters is presented in terms of rate constants and concentrations, derived on the basis of mechanistic considerations. Theoretical expressions for these characteristic parameters are based on a model that includes both the inhibited peroxidation and the uninhibited peroxidation occurring after consumption of the antioxidant(s). Comparison between theoretically predicted dependencies and experimental data support our treatment considered with special emphasis on transition metals-induced peroxidation of lipoproteins.

  1. IR image quality assessment and real-time optimum seeking method based on dynamic visual characteristics

    NASA Astrophysics Data System (ADS)

    Li, Bin; Liu, Gang; Gao, Yongmin; Lei, Hao; Wu, Haiying; Wang, Yu; Rong, Xiaolong

    2016-10-01

    Image quality is an important factor that influences the dynamic target information perception; it is the key factor of real-time target state analysis and judgment. In order to solve the multi-observation station comparison and video optimum seeking problem in the process of target information perception and recognition, an image quality assessment method based on visual characteristics is proposed for infrared target tracking. First, it analyses the basic infrared target image characteristics and application requirements, analyses the status and problems of the multi station optimum seeking technology. According to the expected research results, the processing flow of image processing is established. Then, the image quality objective assessment index is established, which reflects the basic characteristics of the target image, and the assessment index is integrated into the normalized assessment function. According to the quality assessment function, the infrared image quality assessment based on infrared target recognition and image analysis processing is realized, which is mainly characterized by the region of interest and dynamic visual characteristics. And on the basis of this technology, the real-time optimum seeking of multi station infrared target tracking image is completed. In order to verify the effectiveness of the method and the practical application effect, it designs the quality assessment and comparison of different station infrared images. Example shows that the method proposed in this paper can realize multi-observation station infrared image assessment comparison, image quality sorting, the optimum seeking of the infrared image based on the quality assessment. The results accord with the characteristics of infrared target image and dynamic visual characteristics.

  2. Application of characteristic time concepts for hydraulic fracture configuration design, control, and optimization. Final report

    SciTech Connect

    Advani, S.H.; Lee, T.S.; Moon, H.

    1992-10-01

    The analysis of pertinent energy components or affiliated characteristic times for hydraulic stimulation processes serves as an effective tool for fracture configuration designs optimization, and control. This evaluation, in conjunction with parametric sensitivity studies, provides a rational base for quantifying dominant process mechanisms and the roles of specified reservoir properties relative to controllable hydraulic fracture variables for a wide spectrum of treatment scenarios. Results are detailed for the following multi-task effort: (a) Application of characteristic time concept and parametric sensitivity studies for specialized fracture geometries (rectangular, penny-shaped, elliptical) and three-layered elliptic crack models (in situ stress, elastic moduli, and fracture toughness contrasts). (b) Incorporation of leak-off effects for models investigated in (a). (c) Simulation of generalized hydraulic fracture models and investigation of the role of controllable vaxiables and uncontrollable system properties. (d) Development of guidelines for hydraulic fracture design and optimization.

  3. Application of characteristic time concepts for hydraulic fracture configuration design, control, and optimization

    SciTech Connect

    Advani, S.H.; Lee, T.S. ); Moon, H. )

    1992-10-01

    The analysis of pertinent energy components or affiliated characteristic times for hydraulic stimulation processes serves as an effective tool for fracture configuration designs optimization, and control. This evaluation, in conjunction with parametric sensitivity studies, provides a rational base for quantifying dominant process mechanisms and the roles of specified reservoir properties relative to controllable hydraulic fracture variables for a wide spectrum of treatment scenarios. Results are detailed for the following multi-task effort: (a) Application of characteristic time concept and parametric sensitivity studies for specialized fracture geometries (rectangular, penny-shaped, elliptical) and three-layered elliptic crack models (in situ stress, elastic moduli, and fracture toughness contrasts). (b) Incorporation of leak-off effects for models investigated in (a). (c) Simulation of generalized hydraulic fracture models and investigation of the role of controllable vaxiables and uncontrollable system properties. (d) Development of guidelines for hydraulic fracture design and optimization.

  4. Effect of mixing time on the structural characteristics of noodle dough under vacuum.

    PubMed

    Liu, Rui; Xing, Yanan; Zhang, Yingquan; Zhang, Bo; Jiang, Xuju; Wei, Yimin

    2015-12-01

    The structural characteristics of noodle dough under different vacuum mixing times were investigated using three flour samples by texture profile analysis (TPA), SEM, FTIR micro-imaging, and by measuring the glutenin macropolymer and free -SH content. The sheeted dough mixed for 8 min presented better textural properties and a more compact and even microstructure. Insufficient mixing resulted in an uneven distribution and an inadequately developed gluten network, especially for weak-gluten flour (Jimai 22). Excessive mixing was detrimental to the developed dough network and decreased the uniformity of component spatial distribution. Furthermore, excessive mixing led to a decrease in GMP content as well as the increase in free -SH content. Flours with different protein characteristics behaved differently. The TPA, microstructure and free -SH content of dough of Zhengmai 366 was less affected by mixing time than that of Jimai 22, suggesting that strong-gluten flour has better noodle dough mixing tolerance.

  5. Sociodemographic Characteristics and Waking Activities and their Role in the Timing and Duration of Sleep

    PubMed Central

    Basner, Mathias; Spaeth, Andrea M.; Dinges, David F.

    2014-01-01

    Study Objectives: Chronic sleep restriction is prevalent in the U.S. population and associated with increased morbidity and mortality. The primary reasons for reduced sleep are unknown. Using population data on time use, we sought to identify individual characteristics and behaviors associated with short sleep that could be targeted for intervention programs. Design: Analysis of the American Time Use Survey (ATUS). Setting: Cross-sectional annual survey conducted by the U.S. Bureau of Labor Statistics. Participants: Representative cohort (N = 124,517) of Americans 15 years and older surveyed between 2003 and 2011. Interventions: None. Measurements and Results: Telephone survey of activities over 24 hours. Relative to all other waking activities, paid work time was the primary waking activity exchanged for sleep. Time spent traveling, which included commuting to/from work, and immediate pre- and post-sleep activities (socializing, grooming, watching TV) were also reciprocally related to sleep duration. With every hour that work or educational training started later in the morning, sleep time increased by approximately 20 minutes. Working multiple jobs was associated with the highest odds for sleeping ≤ 6 hours on weekdays (adjusted OR 1.61, 95% CI 1.44; 1.81). Self-employed respondents were less likely to be short sleepers compared to private sector employees (OR 0.83, 95% CI 0.72; 0.95). Sociodemographic characteristics associated with paid work (age 25-64, male sex, high income, and employment per se) were consistently associated with short sleep. Conclusions: U.S. population time use survey findings suggest that interventions to increase sleep time should concentrate on delaying the morning start time of work and educational activities (or making them more flexible), increasing sleep opportunities, and shortening morning and evening commute times. Reducing the need for multiple jobs may increase sleep time, but economic disincentives from working fewer hours

  6. Investigation of time characteristics of photodetectors based on Ge/Si nanoheterostructures

    NASA Astrophysics Data System (ADS)

    Donchenko, V. A.; Yakimov, A. I.; Zemlyanov, A. A.; Kirienko, V. V.

    2010-10-01

    Results of investigations into the time characteristics of photosensitive layers based on Ge/Si nanoheterostructures excited by femtosecond laser pulses with a wavelength of 1.55 μm are given. It is demonstrated that the leading front duration of the photoresponse pulse for the examined specimens excited by laser pulses of 120 fs duration does not exceed 30-40 пs.

  7. Associations of various family characteristics and time use with children's body mass index.

    PubMed

    Forshee, Richard A; Anderson, Patricia A; Storey, Maureen L

    2009-04-01

    This study used multiple regression models to estimate associations of various family characteristics and time use with the body mass index (BMI) z-scores of 734 boys and 725 girls aged 5-18y from the Panel Study of Income Dynamics Child Development Supplement 2003. The strongest relationship in the data was between the BMI of the head of household and a child's BMI z-score (p < 0.001). Time spent sleeping, performing sedentary behaviors, and participating in physical activities was not associated with a child's BMI z-score. This suggests that a family-oriented approach to prevent and treat childhood and adolescent overweight is required.

  8. Development of a system for transition characterization. [for aerodynamic simulations

    NASA Technical Reports Server (NTRS)

    Bertelrud, Arild; Graves, Sharon; Diamond, John

    1993-01-01

    The present system for real-time boundary layer transition detection and characterization encompasses aerodynamic simulations, sensor characteristics, and a hybrid analog/digital system for signal analysis, verification, and compression. By using artificial, intermittently laminar/turbulent signals, in conjunction with trajectory simulation, it becomes possible to conduct algorithm development which is independent of, and in advance of, sensor buildup. Attention is given to the illustrative case of the Pegasus launch vehicle's trajectory.

  9. A benchmark test of accuracy and precision in estimating dynamical systems characteristics from a time series.

    PubMed

    Rispens, S M; Pijnappels, M; van Dieën, J H; van Schooten, K S; Beek, P J; Daffertshofer, A

    2014-01-22

    Characteristics of dynamical systems are often estimated to describe physiological processes. For instance, Lyapunov exponents have been determined to assess the stability of the cardio-vascular system, respiration, and, more recently, human gait and posture. However, the systematic evaluation of the accuracy and precision of these estimates is problematic because the proper values of the characteristics are typically unknown. We fill this void with a set of standardized time series with well-defined dynamical characteristics that serve as a benchmark. Estimates ought to match these characteristics, at least to good approximation. We outline a procedure to employ this generic benchmark test and illustrate its capacity by examining methods for estimating the maximum Lyapunov exponent. In particular, we discuss algorithms by Wolf and co-workers and by Rosenstein and co-workers and evaluate their performances as a function of signal length and signal-to-noise ratio. In all scenarios, the precision of Rosenstein's algorithm was found to be equal to or greater than Wolf's algorithm. The latter, however, appeared more accurate if reasonably large signal lengths are available and noise levels are sufficiently low. Due to its modularity, the presented benchmark test can be used to evaluate and tune any estimation method to perform optimally for arbitrary experimental data.

  10. Predictors of race time in male Ironman triathletes: physical characteristics, training, or prerace experience?

    PubMed

    Knechtle, Beat; Wirth, Andrea; Rosemann, Thomas

    2010-10-01

    The aim of the present study was to assess whether physical characteristics, training, or prerace experience were related to performance in recreational male Ironman triathletes using bi- and multivariate analysis. 83 male recreational triathletes who volunteered to participate in the study (M age 41.5 yr., SD = 8.9) had a mean body height of 1.80 m (SD = 0.06), mean body mass of 77.3 kg (SD = 8.9), and mean Body Mass Index of 23.7 kg/m2 (SD = 2.1) at the 2009 IRONMAN SWITZERLAND competition. Speed in running during training, personal best marathon time, and personal best time in an Olympic distance triathlon were related to the Ironman race time. These three variables explained 64% of the variance in Ironman race time. Personal best marathon time was significantly and positively related to the run split time in the Ironman race. Faster running while training and both a fast personal best time in a marathon and in an Olympic distance triathlon were associated with a fast Ironman race time.

  11. Characteristic Times of Gradual Solar Energetic Particle Events and Their Dependence on Associated Coronal Mass Ejection Properties

    DTIC Science & Technology

    2005-08-01

    2. REPORT TYPE 3. DATES COVERED (From - To) 01-08-2005 REPRINT 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Characteristic Times of Gradual Solar ...coronagraph on SOHO observed during 1998-2002 to statistically determine three characteristic times of gradual solar energetic particle (SEP) events as...functions of solar source longitude: (1) To, the time from associated CME launch to SEP onset at I AU, (2) TR, the rise time from SEO onset to the time when

  12. Program and Teacher Characteristics Predicting the Implementation of Banking Time with Preschoolers Who Display Disruptive Behaviors.

    PubMed

    Williford, Amanda P; Wolcott, Catherine Sanger; Whittaker, Jessica Vick; Locasale-Crouch, Jennifer

    2015-11-01

    This study examined the relationship among baseline program and teacher characteristics and subsequent implementation of Banking Time. Banking Time is a dyadic intervention intended to improve a teacher's interaction quality with a specific child. Banking Time implementation was examined in the current study using a sample of 59 teachers and preschool children displaying disruptive behaviors in the classroom (~three children per classroom). Predictors included preschool program type, teacher demographic characteristics (personal and professional), and teacher beliefs (self-efficacy, authoritarian beliefs, and negative attributions about child disruptive behavior). Multiple measures and methods (i.e., teacher report, consultant report, independent observations) were used to assess implementation. We created three implementation composite measures (dosage, quality, and generalized practice) that had high internal consistencies within each composite but were only modestly associated with one another, suggesting unique constructs of implementation. We found that type of preschool program was associated with dosage and quality. Aspects of teacher demographics related to all three implementation composites. Teacher beliefs predicted dosage and generalized practice. Results suggest that the factors that predict the implementation of Banking Time vary as a function of the type of implementation being assessed.

  13. Usefulness of precise time stamping for exposing network characteristics on high-speed links

    NASA Astrophysics Data System (ADS)

    Kitatsuji, Yoshinori; Tsuru, Masato; Katsuno, Satoshi; Oie, Yuji

    2004-09-01

    To expose network characteristics by active/passive measurements, measuring some timing issues such as one-way delay, one-way queuing delay, and inter-packet time is essential, and is conducted by time-stamping for packets passing through an observation point. However, emerging high-speed networks require very high precision of time-stamping, far beyond the precision of conventional software-based time-stamping systems such as 'tcpdump'. For example, the inter-packet time of two consecutive 64-byte length packets on a giga-bit link can be less than 0.001 msec. In this paper, to demonstrate the usefulness and strong necessity of precise time-stamping on high-speed links, experiments of network measurements over a nation-wide IPv6 testbed in Japan have been performed, using a hardware-based time-stamping system that can synchronize to GPS with a high resolution of 0.0001 msec and within a small error of 0.0003 msec. In our experiments, several interesting results are seen, e.g., i) the distribution of one-way queuing delay exhibits a considerable difference depending on the size and the type (UDP/ICMP) of packets; ii) the minimal one-way delays for various sizes of UDP/ICMP packets give an accurate estimate of the transmission delay and the propagation delay; iii) the correlation between interpacket times at the sender and the receiver sides in a sequence of TCP ACK packets clearly shows the degree of ACK compression; iv) the inter-packet time in a UDP stream generated by a DV streaming application shows three dominant sending rates and a very rare peak rate, which might provide crucial information to bandwidth dimensioning; all of which would indicate the usefulness of precise time-stamping.

  14. Acoustic signal characteristics of laser induced cavitation in DDFP droplet: Spectrum and time-frequency analysis.

    PubMed

    Feng, Yi; Qin, Dui; Zhang, Jun; Ma, Chenxiang; Wan, Mingxi

    2015-01-01

    Cavitation has great application potential in microvessel damage and targeted drug delivery. Concerning cavitation, droplet vaporization has been widely investigated in vitro and in vivo with plasmonic nanoparticles. Droplets with a liquid dodecafluoropentane (DDFP) core enclosed in an albumin shell have a stable and simple structure with good characteristics of laser absorbing; thus, DDFP droplets could be an effective aim for laser-induced cavitation. The DDPF droplet was prepared and perfused in a mimic microvessel in the optical microscopic system with a passive acoustic detection module. Three patterns of laser-induced cavitation in the droplets were observed. The emitted acoustic signals showed specific spectrum components at specific time points. It was suggested that a nanosecond laser pulse could induce cavitation in DDPF droplets, and specific acoustic signals would be emitted. Analyzing its characteristics could aid in monitoring the laser-induced cavitation process in droplets, which is meaningful to theranostic application.

  15. Adults’ reports of their earliest memories: Consistency in events, ages, and narrative characteristics over time

    PubMed Central

    Bauer, Patricia J.; Tasdemir-Ozdes, Aylin; Larkina, Marina

    2014-01-01

    Earliest memories have been of interest since the late 1800s, when it was first noted that most adults do not have memories from the first years of life (so-called childhood amnesia). Several characteristics of adults’ earliest memories have been investigated, including emotional content, the perspective from which they are recalled, and vividness. The focus of the present research was a feature of early memories heretofore relatively neglected in the literature, namely, their consistency. Adults reported their earliest memories 2 to 4 times over a 4-year period. Reports of earliest memories were highly consistent in the events identified as the bases for earliest memories, the reported age at the time of the event, and in terms of qualities of the narrative descriptions. These findings imply stability in the boundary that marks the offset of childhood amnesia, as well as in the beginning of a continuous sense of self over time. PMID:24836979

  16. [Atmospheric pollution characteristic during fireworks burning time in spring festival in Quanzhou suburb].

    PubMed

    Zhao, Jin-ping; Xu, Ya; Zhang, Fu-wang; Chen, Jin-sheng

    2011-05-01

    Atmospheric pollution characteristics during fireworks burning time in 2009 Spring Festival in Quangzhou suburb were studied. Particulate aerosol has been monitored and collected using real-time monitor and middle-volume sampler during fireworks burning time. The objectives of this study were to identify the contents and distributing characteristics of particles, polycyclic aromatic hydrocarbon (PAHs) and water-soluble ions and to discuss sources of these pollutants. The results showed that PM2.5 and PM10 were increased significantly during fireworks burning time. The highest concentration of particles presented time of 00:57-01:27 on New Year's Eve, which the average concentration of PM2.5 and PM10 were reached 1102.43 microm(-3) and 1610.22 microg x m(-3) in 30 min. The concentration of particle- and gas-PAHs were 54.18 ng x m(-1) and 47.10 ng x m(-3), respectively, during fireworks burning time in New Year's Eve, which were higher than that in the normal day. It can be judged by the diagnostic ratios that the primary source of PAHs in Quanzhou suburb were the combustion of coal, biomass and the exhaust emission from diesel vehicles in this region. Results of water-soluble ions indicated that fireworks burning were the main reason to lead to higher concentration of these ions during Spring Festival. Moreover, pollution gases of NOx and SO2 that were origined from fireworks burning, coal combustion and exhaust emission from motor vehicle were supplied precursors to form secondary pollutants, such as NO3- and SO4(2-).

  17. Characteristic coupling time between axial and transverse energy modes for anti-hydrogen in magnetostatic traps

    NASA Astrophysics Data System (ADS)

    Zhong, Mike; Fajans, Joel

    2016-10-01

    For upcoming ALPHA collaboration laser spectroscopy and gravity experiments, the nature of the chaotic trajectories of individual antihydrogen atoms trapped in the octupole Ioffe magnetic trap is of importance. Of particular interest for experimental design is the coupling time between the axial and transverse modes of energy for the antihydrogen atoms. Using Monte Carlo simulations of semiclassical dynamics of antihydrogen trajectories, we quantify this characteristic coupling time between axial and transverse modes of energy. There appear to be two classes of trajectories: for orbits whose axial energy is higher than 10% of the total energy, the axial energy varies chaotically on the order of 1-10 seconds, whereas for orbits whose axial energy is around 10% of the total energy, the axial energy remains nearly constant on the order of 1000 seconds or longer. Furthermore, we search through parameter -space to find parameters of the magnetic trap that minimize and maximize this characteristic coupling time. This work was supported by the UC Berkeley Summer Undergraduate Research Fellowship, the Berkeley Research Computing program, the Department of Energy contract DE-FG02-06ER54904, and the National Science Foundation Grant 1500538-PHY.

  18. Flow visualization of time-varying structural characteristics of dean vortices in a curved channel

    NASA Astrophysics Data System (ADS)

    Bella, David Wayne

    1988-12-01

    The time varying development and structure of Dean vortices were studied using flow visualization. Observations were made over a range of Dean numbers from 40 to 200 using a transparent channel with mild curvature, 40:1 aspect ratio, and an inner to outer radius ratio of 0.979. Seven flow visualization techniques were tried but only one, a wood burning smoke generator, produced usable results. Different vortex characteristics were observed and documented in sequences of photographs spaced one quarter of a second apart at locations ranging from 85 to 135 degrees from the start of curvature. Evidence is presented that supports the twisting/rocking nature of the flow.

  19. Characteristics of the boundary-layer equations of the minimum time-to-climb problem

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.

    1976-01-01

    In many singular perturbation solutions of optimal control problems, the most difficult numerical task is to solve the boundary-layer equations. However, these equations have a special structure that may often be used to expedite their solution. This paper begins by noting the general nature of the boundary-layer equations for optimal control problems. These results are then applied to the aircraft minimum time-to-climb problem. A specific numerical example is considered to illustrate the characteristics of the solution of the boundary-layer equations for this problem.

  20. Study of distribution and characteristics of the time average of pressure of a water cushion pool

    NASA Astrophysics Data System (ADS)

    Guo, Y. H.; Fu, J. F.

    2016-08-01

    When a dam discharges flood water, the plunging flow with greater kinetic energy, will scour the riverbed, resulting in erosion damage. In order to improve the anti-erosion capacity of a riverbed, the cushion pool created. This paper is based on turbulent jet theoryto deduce the semi-empirical formula of the time average of pressure in the impinging portion of the cushion pool. Additionally, MATLAB numerical is used to conduct a simulation analysis according to turbulent jet energy and watercushion depth when water floods into the water cushion pool, to determine the regularities of distribution and related characteristics.

  1. Associations of Neighborhood Characteristics with Sleep Timing and Quality: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    DeSantis, Amy S.; Diez Roux, Ana V.; Moore, Kari; Baron, Kelly G.; Mujahid, Mahasin S.; Nieto, F. Javier

    2013-01-01

    Study Objectives: To investigate the associations of specific neighborhood features (disorder, safety, social cohesion, physical environment, and socioeconomic status) with sleep duration and quality. Design: Cross-sectional. One wave of a population-based study (Multi-Ethnic Study of Atherosclerosis). Setting: Community-dwelling participants in New York, NY and Los Angeles, CA. Participants: There were 1,406 participants (636 males, 770 females). Interventions: NA. Measurements and Results: Sleep was assessed using reported hours of sleep, the Epworth Sleepiness Scale, and insomnia symptoms. Neighborhood characteristics were assessed via questionnaires administered to neighbors of study participants and were aggregated to the neighborhood (census tract) level using empirical Bayes estimation. An adverse social environment (characterized by high disorder, and low safety and social cohesion) was associated with shorter sleep duration after adjustment for the physical environment, neighborhood and individual-level socioeconomic status (SES), and other short sleep risk factors (mean difference per standard deviation increase in summary social environment scale 0.24 h 95% confidence interval 0.08, 0.43). Adverse neighborhood social and physical environments, and neighborhood SES were associated with greater sleepiness, but associations with physical environments were no longer statistically significant after adjustment for sociodemographic characteristics. Neighborhood SES was a weaker and less consistent predictor of specific measures of neighborhood social and physical environments. Neighborhood characteristics were not associated with insomnia. Conclusions: Shortened sleep related to adverse social environments represents one potential pathway through which neighborhoods may influence health. Citation: DeSantis AS; Diez Roux AV; Moore K; Baron KG; Mujahid MS; Nieto FJ. Associations of neighborhood characteristics with sleep timing and quality: the multi-ethnic study

  2. Exploring the Relationship Between Hydrograph Characteristics and the Time Evolution of Sand Bed Morphology

    NASA Astrophysics Data System (ADS)

    Ockelford, A.; Parsons, D. R.; Hardy, R. J.; Ashworth, P. J.; Best, J.

    2015-12-01

    The development of sand bed morphology in response to steady flow is adequately described in most bedform phase diagrams. This includes the prediction of bedform wavelength, height and shape, all important parameters in estimating flow resistance. However, during time-varying flow, such as that experienced during the passage of a flood wave, the implicit assumption that bedform adjustment tracks changes in flow depth and velocity does not hold true due to bedform hysteresis. Consequently, there is a need to understand which characteristics of unsteady flow drive the disequilibrium dynamics between bedform geometry and hydraulic conditions. This paper describes a series of experiments designed to identify the impacts of hydrograph characteristics on the morphodynamic evolution of alluvial dunes. Mobile sand bed (D50 of 450μm) experiments were undertaken in a 16m long, 1.6m wide flume. Sediment was water worked under steady unidirectional flow until equilibrium bed conditions were achieved, after which a hydrograph was applied. At the end of the hydrograph, a period of steady flow was once again run until equilibrium conditions were attained. Hydrograph one consisted of steeply rising (80 minutes) and falling (65 minutes) limbs with hydrograph two characterised by longer rising (170 minutes) and falling (230 minutes) limbs. During the hydrograph discharge was changed in discrete steps. Bed morphology profiles were measured continuously along a 5m by 0.6m, centreline transect using twelve ultrasonic sensors. Three-dimensional flow was measured with a stack of Acoustic Doppler Velocimeters downstream of the transect. Suspended sediment was quantified using a three-frequency set of Acoustic Backscatter Sensors. The impact of these differing hydrograph characteristics are discussed in terms of differences between equilibrium bed morphologies, evolving flow field characteristics and the dynamics of suspended sediment concentrations through the hydrographs.

  3. A New Characteristic Function for Fast Time-Reverse Seismic Event Location

    NASA Astrophysics Data System (ADS)

    Hendriyana, Andri; Bauer, Klaus; Weber, Michael; Jaya, Makky; Muksin, Muksin

    2015-04-01

    Microseismicity produced by natural activities is usually characterized by low signal-to-noise ratio and huge amount of data as recording is conducted for a long period of time. Locating microseismic events is preferably carried out using migration-based methods such as time-reverse modeling (TRM). The original TRM is based on backpropagating the wavefield from the receiver down to the source location. Alternatively, we are using a characteristic function (CF) derived from the measured wavefield as input for the TRM. The motivation for such a strategy is to avoid undesired contributions from secondary arrivals which may generate artifacts in the final images. In this presentation, we introduce a new CF as input for TRM method. To obtain this CF, initially we apply kurtosis-based automatic onset detection and convolution with a given wavelet. The convolution with low frequency wavelets allows us to conduct time-reverse modeling using coarser sampling hence it will reduce computing time. We apply the method to locate seismic events measured along an active part of the Sumatra Fault around the Tarutung pull-apart basin (North Sumatra, Indonesia). The results show that seismic events are well-determined since they are concentrated along the Sumatran fault. Internal details of the Tarutung basin structure could be derived. Our results are consistent with those obtained from inversion of manually picked travel time data.

  4. The application of time decay characteristics of laser-induced fluorescence in the classification of vegetation.

    PubMed

    Gong, Wei; Yang, Jian; Shi, Shuo; Du, Lin; Sun, Jia; Song, Shalei

    2017-02-01

    In this study, the time decay of the chlorophyll fluorescence intensity (TDCFI) of vegetation was measured based on laser-induced fluorescence (LIF) technology with a 355 nm laser serving as the excitation light source. The pseudo-color diagram of the TDCFI (PDTDCFIs) was proposed for use as a characteristic fingerprint for the analysis of various plant species based on variations in the fluorescence intensity over time. Compared with the steady-state fluorescence spectra, two-dimensional PDTDCFIs contained more spectral information, including variations in both the shape of the laser-induced fluorescence spectra and the relative intensity. The experimental results demonstrated that the PDTDCFIs of various plant species show distinct differences, and this was successfully applied in the classification of plant species. Therefore, the PDTDCFIs of plants could provide researchers with a more reliable and useful tool for the characterization of vegetation. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Numerical solution of the time dependent neutron transport equation by the method of the characteristics

    NASA Astrophysics Data System (ADS)

    Talamo, Alberto

    2013-05-01

    This study presents three numerical algorithms to solve the time dependent neutron transport equation by the method of the characteristics. The algorithms have been developed taking into account delayed neutrons and they have been implemented into the novel MCART code, which solves the neutron transport equation for two-dimensional geometry and an arbitrary number of energy groups. The MCART code uses regular mesh for the representation of the spatial domain, it models up-scattering, and takes advantage of OPENMP and OPENGL algorithms for parallel computing and plotting, respectively. The code has been benchmarked with the multiplication factor results of a Boiling Water Reactor, with the analytical results for a prompt jump transient in an infinite medium, and with PARTISN and TDTORT results for cross section and source transients. The numerical simulations have shown that only two numerical algorithms are stable for small time steps.

  6. Early-time plasma expansion characteristics of ionized clouds in the ionosphere

    NASA Technical Reports Server (NTRS)

    Schunk, R. W.; Szuszczewicz, E. P.

    1988-01-01

    A series of Vlasov-Poisson simulations were conducted with barium and lithium gas mixtures expanding into an O(+) background plasma, with the values for the Ba(+)/Li(+) composition ratios and the cloud/background density ratios based on anticipated release values in the upcoming Combined Release and Radiation Effects Satellite (CRRES) experiment. The results obtained on the early-time expansion of high-density Ba(+), Li(+), and Ba(+)-Li(+) plasma clouds into low-density O(+) background plasma complement the H(+)-O(+) expansions of Gurevich et al. (1973) and Singh and Schunk (1982, 1983), and the characteristic features observed apply to the very-early-time expansion phase of the CRRES releases.

  7. EFFECTS OF PLATING DENSITY AND CULTURE TIME ON BONE MARROW STROMAL CELL CHARACTERISTICS

    PubMed Central

    Neuhuber, Birgit; Swanger, Sharon A.; Howard, Linda; Mackay, Alastair; Fischer, Itzhak

    2008-01-01

    Objective Bone marrow stromal cells (MSC) are multipotent adult stem cells that have emerged as promising candidates for cell therapy in disorders including cardiac infarction, stroke and spinal cord injury. While harvesting methods used by different laboratories are relatively standard, MSC culturing protocols vary widely. This study is aimed at evaluating the effects of initial plating density and total time in culture on proliferation, cell morphology, and differentiation potential of heterogeneous MSC cultures and more homogeneous cloned subpopulations. Methods Rat MSC were plated at 20, 200 and 2000 cells/cm2 and grown to 50% confluency. The numbers of population doublings and doubling times were determined within and across multiple passages. Changes in cell morphology and differentiation potential to adipogenic, chondrogenic, and osteogenic lineages were evaluated and compared among early, intermediate and late passages, as well as between heterogeneous and cloned MSC populations. Results We found optimal cell growth at a plating density of 200 cells/cm2. Cultures derived from all plating densities developed increased proportions of flat cells over time. Assays for chondrogenesis, osteogenesis and adipogenesis showed that heterogeneous MSC plated at all densities sustained the potential for all three mesenchymal phenotypes through at least passage 5; the flat subpopulation lost adipogenic and chondrogenic potential. Conclusion Our findings suggest that the initial plating density is not critical for maintaining a well-defined, multipotent MSC population. Time in culture, however, affects cell characteristics, suggesting that cell expansion should be limited, especially until the specific characteristics of different MSC subpopulations are better understood. PMID:18495329

  8. Norm stability in Jirisan National Park: effects of time, existing conditions, and background characteristics.

    PubMed

    Kim, Sang-Oh; Shelby, Bo

    2008-04-01

    Norm stability is an important issue to consider in using the normative approach as a component of resource management decision making. This study examines three major questions related to norm stability: (1) Do norms change over time? (2) Do existing conditions affect norms? (3) Do background characteristics and visitation patterns affect norms? Data used in this study were collected at a campground in the Jirisan National Park (JNP) of Korea in 1993, 1994, and 2003. A total of 396 subjects were used for the study (120 for 1993, 106 for 1994, and 170 for 2003). Changes in the standards for "quiet time" and "seeing others littering" were statistically significant, but there was no change in the standard for "number of other tents." There was little change in norm agreement or norm prevalence. Existing conditions were strongly correlated with standards for number of other tents but results were mixed for the other two indicators. Users' demographic characteristics and visitation patterns were not generally related to norms. Findings of the study are discussed.

  9. Time domain characteristics of wave motion in dispersive and anisotropic continuum acoustic metamaterials.

    PubMed

    Wang, Zhaojun; Zhou, Xiaoming

    2016-12-01

    The authors study the wave propagation in continuum acoustic metamaterials whose all or not all of the principal elements of the mass tensor or the scalar compressibility can be negative due to wave dispersion. Their time-domain wave characteristics are particularly investigated by the finite-difference time-domain (FDTD) method, in which algorithms for the Drude and Lorentz dispersion pertinent to acoustic metamaterials are provided necessarily. Wave propagation nature of anisotropic acoustic metamaterials with all admissible material parameters are analyzed in a general manner. It is found that anomalous negative refraction phenomena can appear in several dispersion regimes, and their unique time-domain signatures have been discovered by the FDTD modeling. It is further proposed that two different metamaterial layers with specially assigned dispersions could comprise a conjugate pair that permits wave propagation only at specific points in the wave vector space. The time-domain pulse simulation verifies that acoustic directive radiation capable of modulating radiation angle with the wave frequency can be realized with this conjugate pair. The study provides the detailed analysis of wave propagation in anisotropic and dispersive acoustic mediums, which makes a further step toward dispersion engineering and transient wave control through acoustic metamaterials.

  10. Lean burn limit and time to light characteristics of laser ignition in gas turbines

    NASA Astrophysics Data System (ADS)

    Griffiths, J.; Riley, M.; Kirk, A.; Borman, A.; Lawrence, J.; Dowding, C.

    2014-04-01

    This work details a study of laser ignition in a low pressure combustion test rig, representative of an industrial gas turbine (SGT-400, Siemens Industrial Turbomachinery Ltd.) and for the first time investigates the effect of air mass flow rate on combustion characteristics at air/fuel ratios at the lean burn limit. Both the lean burn limit and time taken to light are essential in determining the suitability of a specified air/fuel ratio, especially in multi-chamber ignition applications. Through extension of the lean burn limit and reduction of the time taken to light, the operating window for ignition with regards to the air/fuel ratio can be increased, leading to greater reliability and repeatability of ignition. Ignition of a natural gas and air mixture at atmospheric pressure was conducted using both a standard high energy igniter and a laser ignition system utilizing a Q-switched Nd:YAG laser source operating at 1064 nm wavelength. A detailed comparison of the lean burn limit and time taken to light for standard ignition and laser ignition is presented.

  11. Stratigraphy and Characteristic Time Scales of Northern Polar and Circumpolar Deposits on Mars

    NASA Astrophysics Data System (ADS)

    Kreslavsky, M. A.; Head, J. W.

    2002-05-01

    The north polar region is dominated by the polar cap cut by troughs and Chasma Boreale, surrounded by the north polar erg and overlying the Vastitas Borealis Formation. A thin layer of mantle with characteristic "basketball" texture typical for high latitudes covers the surface of Vastitas Borealis Formation. Study of the high-resolution MGS MOC images showed that the dunes migrate over this mantle. The stratigraphic relationships of this mantle and icy deposits, as well as Chasma Boreale-related deposits are more complex. Chasma Boreale has been interpreted to be initiated as an outflow event (Fishbaugh and Head, JGR, JE001351, 2002). We estimate that the time scale of the meltwater accumulation at the base of the polar cap and the time scale of establishing the thermal equilibrium in the cap are on the order of 0.5 Myr or greater. We compare this time scale with the characteristic astronomically predicted time scales: the time scale of obliquity oscillations (0.05 Myr), the period of obliquity oscillations about 25 deg (3.5 Myr), and the time scale of chaotic obliquity variations (5 Myr). During the period 3.5 - 5 Myr ago the obliquity oscillated around 35 deg, which led to noticeably higher polar cap temperatures and a shallower depth of the melting isotherm than during the present epoch. Predictions of obliquity in the earlier epochs beyond 5 Myr are impossible. We conclude that the period of intensive reshaping of the polar cap and formation of Chasma Boreale occurred 3.5 Myr ago or earlier. During the last 3.5 Myr the cap was rather similar to present; minor erosion and deposition of the upper layers could occur, along with modest trough migration in the short epochs of the highest obliquity. The accumulation of the main mass of the finely layered deposits occurred at least 0.5 - 1 Myr (and may be much earlier) than the Chasma Boreale flood. The accumulation could occur in response to some obliquity-driven climate variation or due to some endogenic discharge

  12. Time-Frequency Characteristics of Tsunami Magnetic Signals from Four Pacific Ocean Events

    NASA Astrophysics Data System (ADS)

    Schnepf, N. R.; Manoj, C.; An, C.; Sugioka, H.; Toh, H.

    2016-12-01

    The recent deployment of highly sensitive seafloor magnetometers coinciding with the deep solar minimum has provided excellent opportunities for observing tsunami electromagnetic signals. These fluctuating signals (periods ranging from 10-20 min) are generally found to be within ± ˜1 nT and coincide with the arrival of the tsunami waves. Previous studies focused on tsunami electromagnetic characteristics, as well as modeling the signal for individual events. This study instead aims to provide the time-frequency characteristics for a range of tsunami signals and a method to separate the data's noise using additional data from a remote observatory. We focus on four Pacific Ocean events of varying tsunami signal amplitude: (1) the 2011 Tohoku, Japan event (M9.0), (2) the 2010 Chile event (M8.8), (3) the 2009 Samoa event (M8.0) and, (4) the 2007 Kuril Islands event (M8.1). We find possible tsunami signals in high-pass filtered data and successfully isolate the signals from noise using a cross-wavelet analysis. The cross-wavelet analysis reveals that the longer period signals precede the stronger, shorter period signals. Our results are very encouraging for using tsunami magnetic signals in warning systems.

  13. Characteristic distribution of finite-time Lyapunov exponents for chimera states

    PubMed Central

    Botha, André E.

    2016-01-01

    Our fascination with chimera states stems partially from the somewhat paradoxical, yet fundamental trait of identical, and identically coupled, oscillators to split into spatially separated, coherently and incoherently oscillating groups. While the list of systems for which various types of chimeras have already been detected continues to grow, there is a corresponding increase in the number of mathematical analyses aimed at elucidating the fundamental reasons for this surprising behaviour. Based on the model systems, there are strong indications that chimera states may generally be ubiquitous in naturally occurring systems containing large numbers of coupled oscillators – certain biological systems and high-Tc superconducting materials, for example. In this work we suggest a new way of detecting and characterising chimera states. Specifically, it is shown that the probability densities of finite-time Lyapunov exponents, corresponding to chimera states, have a definite characteristic shape. Such distributions could be used as signatures of chimera states, particularly in systems for which the phases of all the oscillators cannot be measured directly. For such cases, we suggest that chimera states could perhaps be detected by reconstructing the characteristic distribution via standard embedding techniques, thus making it possible to detect chimera states in systems where they could otherwise exist unnoticed. PMID:27374473

  14. Impact of sludge retention time on sludge characteristics and microbial community in MBR.

    PubMed

    Su, Yuchun; Pan, Jill Ruhsing; Huang, Chihpin; Chang, Chialing

    2011-01-01

    In this study, the impact of sludge retention time (SRT) on sludge characteristics and microbial community and the effect on membrane fouling in membrane bioreactor (MBR) was investigated. The results show that MBR with longer SRT has less fouling propensity, in agreement with other studies, despite the fact that the MBR with longer SRT contained higher MLSS and smaller particle size. However, much more soluble microbial products (SMPs) were released in MBR with shorter SRT. More slime on the membrane surface was observed in MBR with shorter SRT while sludge cakes formed on the membrane surface in MBR with longer SRT. The results show that SMP contributes to the severe fouling observed in MBR with shorter SRT, which is in agreement with other studies showing that SMPs were the major foulants in MBR. Under different SRTs of operation, the bacterial community structures of the sludge obtained by use of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were almost identical, but those on the membrane surface differed substantially. It suggests that, although SRT has impact on sludge characteristics, it doesn't affect the microbial community in the suspension.

  15. Norm Stability in Jirisan National Park: Effects of Time, Existing Conditions, and Background Characteristics

    NASA Astrophysics Data System (ADS)

    Kim, Sang-Oh; Shelby, Bo

    2008-04-01

    Norm stability is an important issue to consider in using the normative approach as a component of resource management decision making. This study examines three major questions related to norm stability: (1) Do norms change over time? (2) Do existing conditions affect norms? (3) Do background characteristics and visitation patterns affect norms? Data used in this study were collected at a campground in the Jirisan National Park (JNP) of Korea in 1993, 1994, and 2003. A total of 396 subjects were used for the study (120 for 1993, 106 for 1994, and 170 for 2003). Changes in the standards for “quiet time” and “seeing others littering” were statistically significant, but there was no change in the standard for “number of other tents.” There was little change in norm agreement or norm prevalence. Existing conditions were strongly correlated with standards for number of other tents but results were mixed for the other two indicators. Users’ demographic characteristics and visitation patterns were not generally related to norms. Findings of the study are discussed.

  16. Characteristic distribution of finite-time Lyapunov exponents for chimera states

    NASA Astrophysics Data System (ADS)

    Botha, André E.

    2016-07-01

    Our fascination with chimera states stems partially from the somewhat paradoxical, yet fundamental trait of identical, and identically coupled, oscillators to split into spatially separated, coherently and incoherently oscillating groups. While the list of systems for which various types of chimeras have already been detected continues to grow, there is a corresponding increase in the number of mathematical analyses aimed at elucidating the fundamental reasons for this surprising behaviour. Based on the model systems, there are strong indications that chimera states may generally be ubiquitous in naturally occurring systems containing large numbers of coupled oscillators – certain biological systems and high-Tc superconducting materials, for example. In this work we suggest a new way of detecting and characterising chimera states. Specifically, it is shown that the probability densities of finite-time Lyapunov exponents, corresponding to chimera states, have a definite characteristic shape. Such distributions could be used as signatures of chimera states, particularly in systems for which the phases of all the oscillators cannot be measured directly. For such cases, we suggest that chimera states could perhaps be detected by reconstructing the characteristic distribution via standard embedding techniques, thus making it possible to detect chimera states in systems where they could otherwise exist unnoticed.

  17. Characteristic distribution of finite-time Lyapunov exponents for chimera states.

    PubMed

    Botha, André E

    2016-07-04

    Our fascination with chimera states stems partially from the somewhat paradoxical, yet fundamental trait of identical, and identically coupled, oscillators to split into spatially separated, coherently and incoherently oscillating groups. While the list of systems for which various types of chimeras have already been detected continues to grow, there is a corresponding increase in the number of mathematical analyses aimed at elucidating the fundamental reasons for this surprising behaviour. Based on the model systems, there are strong indications that chimera states may generally be ubiquitous in naturally occurring systems containing large numbers of coupled oscillators - certain biological systems and high-Tc superconducting materials, for example. In this work we suggest a new way of detecting and characterising chimera states. Specifically, it is shown that the probability densities of finite-time Lyapunov exponents, corresponding to chimera states, have a definite characteristic shape. Such distributions could be used as signatures of chimera states, particularly in systems for which the phases of all the oscillators cannot be measured directly. For such cases, we suggest that chimera states could perhaps be detected by reconstructing the characteristic distribution via standard embedding techniques, thus making it possible to detect chimera states in systems where they could otherwise exist unnoticed.

  18. Time-averaged Turbulent Flow Characteristics over a Highly Spatially Heterogeneous Gravel-Bed

    NASA Astrophysics Data System (ADS)

    Sarkar, Sankar

    2016-10-01

    The present study focuses on the time-averaged turbulence characteristics over a highly spatially-heterogeneous gravel-bed. The timeaveraged streamwise velocity, Reynolds shear and normal stresses, turbulent kinetic energy, higher-order moments of velocity fluctuations, length scales, and the turbulent bursting were measured over a gravel-bed with an array of larger gravels. It was observed that the turbulence characteristics do not vary significantly above the crest level of the array as compared to those below the array. The nondimensional streamwise velocity decreases considerably with a decrease in depth below the array. Below the array, the Reynolds shear stress (RSS) deviates from the gravity- law of RSS distributions. Turbulence intensities reduce below the crest level of the gravel-bed. The third-order moments of velocity fluctuations increase below the crest level of the gravel-bed and give a clear indication of sweeps as the predominating event which were further verified with the quadrant analysis plots. The turbulent length scales values change significantly below the crest level of the gravel-bed.

  19. Time-variable Earth's albedo model characteristics and applications to satellite sampling errors

    NASA Technical Reports Server (NTRS)

    Bartman, F. L.

    1981-01-01

    Characteristics of the time variable Earth albedo model are described. With the cloud cover multiplying factor adjusted to produce a global annual average albedo of 30.3, the global annual average cloud cover is 45.5 percent. Global annual average sunlit cloud cover is 48.5 percent; nighttime cloud cover is 42.7 percent. Month-to-month global average albedo is almost sinusoidal with maxima in June and December and minima in April and October. Month-to-month variation of sunlit cloud cover is similar, but not in all details. The diurnal variation of global albedo is greatest from November to March; the corresponding variation of sunlit cloud cover is greatest from May to October. Annual average zonal albedos and monthly average zonal albedos are in good agreement with satellite-measured values, with notable differences in the polar regions in some months and at 15 S. The albedo of some 10 deg by 10 deg. areas of the Earth versus zenith angle are described. Satellite albedo measurement sampling effects are described in local time and in Greenwich mean time.

  20. Effects of subthalamic nucleus stimulation on characteristics of EMG activity underlying reaction time in Parkinson's disease.

    PubMed

    Kumru, Hatice; Summerfield, Christopher; Valldeoriola, Francesc; Valls-Solé, Josep

    2004-01-01

    We examined the effects of high-frequency deep brain stimulation of the subthalamic nucleus (STN-DBS) on characteristics of electromyographic (EMG) activity of the agonist muscle in 8 patients with Parkinson's disease (PD). Patients were examined during STN-DBS (ON), and 30 minutes after switching off both stimulators (OFF). They were asked to make a ballistic movement in paradigms of simple reaction time (SRT) and choice reaction time (CRT) tasks. Onset of movement (MOVonset) was measured as the latency of the initial displacement from baseline of the signal from an accelerometer attached to the dorsum of the hand. In the associated EMG activity, recorded from wrist extensor muscles, we measured onset latency (EMGonset), size of the first EMG burst (EMGsize), and number of EMG bursts (EMGbursts) counted between EMGonset and task execution. MOVonset and EMGonset were significantly shorter in ON than in OFF conditions in CRT. EMGsize was larger, EMGbursts were reduced, and peak of the acceleration profile was larger in ON compared with OFF conditions in both SRT and CRT. Our results indicate that STN-DBS induces a significant improvement in motor performance of reaction time tasks in PD patients. Such improvement is associated with a change in features of the EMG activity suggesting an increase in the excitability of the motor pathways engaged in ballistic movements.

  1. Thermal characteristics of time-periodic electroosmotic flow in a circular microchannel

    NASA Astrophysics Data System (ADS)

    Moghadam, Ali Jabari

    2015-10-01

    A theoretical analysis is performed to explore the thermal characteristics of electroosmotic flow in a circular microchannel under an alternating electric field. An analytical approach is presented to solve energy equation, and then, the exact solution of temperature profiles is obtained by using the Green's function method. This study reveals that the temperature field repeats itself for each half-period. Frequency has a strong influence on the thermal behavior of the flow field. For small values of the dimensionless frequency (small channel size, large kinematic viscosity, or small frequency), the advection mechanism is dominant in the whole domain and the resultant heating (Joule heating and wall heat flux) can be transferred by the complete flow field in the axial direction; while, the middle portion of the flow field at high dimensionless frequencies does not have sufficient time to transfer heat by advection, and the bulk fluid temperature, especially in heating, may consequently become greater than the wall temperature. In a particular instance of cooling mode, a constant surface temperature case is temporarily occurred in which the axial temperature gradient will be zero. For relatively high frequencies, the unsteady bulk fluid temperature in some radial positions at some moments may be equal to the wall temperature; hence instantaneous cylindrical surfaces with zero radial heat flux may occur over a period of time. Depending on the value and sign of the thermal scale ratio, the quasi-steady-state Nusselt number (time-averaged at one period) approaches a specific value as the electrokinetic radius becomes infinity.

  2. Gender, Parenthood and Wage Differences: The Importance of Time-Consuming Job Characteristics.

    PubMed

    Magnusson, Charlotta; Nermo, Magnus

    2017-01-01

    Using data from the Swedish Level of Living Survey (2000, 2010), we investigate how the gender wage gap varies with occupational prestige and family status and also examine the extent to which this gap is explained by time-consuming working conditions. In addition, we investigate whether there is an association between parenthood, job characteristics and wage (as differentiated by gender). The analyses indicate that there are gender differences regarding prestige-based pay-offs among parents that are partly explained by fathers' greater access to employment characterized by time-consuming conditions. Separate analyses for men and women demonstrate the presence of a marriage wage premium for both genders, although only men have a parenthood wage premium. This fatherhood premium is however only present in high-prestigious occupations. Compared with childless men, fathers are also more advantaged in terms of access to jobs with time-consuming working conditions, but the wage gap between fathers and childless men is not explained by differences in access to such working conditions.

  3. [Stormflow hydrochemical characteristics at different time scales in a typical karst catchment of northwest Guangxi, China].

    PubMed

    Liu, Chun; Yang, Jing; Nie, Yun-peng; Chen, Hong-song; Fu, Zhi-yong

    2015-09-01

    Through in situ observation and indoor tests, the hydrochemical characteristics of a typical karst watershed at three different time scales (diurnal, single storm, and seasonal scales) from June 2013 to March 2014 were investigated, and their influencing factors were analyzed. The results showed that the diurnal variations of the hydrochemistry exhibited a regular changing pattern resulting from the shifting of the main vegetation physiological activity from photosynthesis in the day to respiration in the night. At single storm scale, however, the hydrochemical processes were mainly determined by the number of consecutive rainless days and rainfall intensity, while the diurnal scale effect was weakened. As to the seasonal scale, the overall hydrochemical processes showed quick responses to rainfall events although they responded more quickly in the rainy season than in the dry season. The temperature and the yearly rainfall distribution regime were the two main influencing factors at this scale.

  4. Measurements of admittances and characteristic combustion times of reactive gaseous propellant coaxial injectors

    NASA Technical Reports Server (NTRS)

    Janardan, B. A.; Daniel, B. R.; Zinn, B. T.

    1979-01-01

    The results of an experimental investigation that was concerned with the quantitative determination of the capabilities of combustion processes associated with coaxial injectors to amplify and sustain combustor oscillations was described. The driving provided by the combustion process was determined by employing the modified standing-wave method utilizing coaxial injectors and air-acetylene mixtures. Analyses of the measured data indicate that the investigated injectors are capable of initiating and amplifying combustion instabilities under favorable conditions of injector-combustion coupling and over certain frequency ranges. These frequency ranges and the frequency at which an injector's driving capacity is maximum are observed to depend upon the equivalence ratio, the pressure drop across the injector orifices and the number of injector elements. The characteristic combustion times of coaxial injectors were determined from steady state temperature measurements.

  5. Nonlinear parametrically excited vibration and active control of gear pair system with time-varying characteristic

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Wang, Jin-Jin; Liu, Jin-Jie; Li, Ya-Qian

    2015-10-01

    In the present work, we investigate the nonlinear parametrically excited vibration and active control of a gear pair system involving backlash, time-varying meshing stiffness and static transmission error. Firstly, a gear pair model is established in a strongly nonlinear form, and its nonlinear vibration characteristics are systematically investigated through different approaches. Several complicated phenomena such as period doubling bifurcation, anti period doubling bifurcation and chaos can be observed under the internal parametric excitation. Then, an active compensation controller is designed to suppress the vibration, including the chaos. Finally, the effectiveness of the proposed controller is verified numerically. Project supported by the National Natural Science Foundation of China (Grant No. 61104040), the Natural Science Foundation of Hebei Province, China (Grant No. E2012203090), and the University Innovation Team of Hebei Province Leading Talent Cultivation Project, China (Grant No. LJRC013).

  6. Discovering the Impact of Preceding Units' Characteristics on the Wait Time of Cardiac Surgery Unit from Statistic Data

    PubMed Central

    Liu, Jiming; Tao, Li; Xiao, Bo

    2011-01-01

    Introduction Prior research shows that clinical demand and supplier capacity significantly affect the throughput and the wait time within an isolated unit. However, it is doubtful whether characteristics (i.e., demand, capacity, throughput, and wait time) of one unit would affect the wait time of subsequent units on the patient flow process. Focusing on cardiac care, this paper aims to examine the impact of characteristics of the catheterization unit (CU) on the wait time of cardiac surgery unit (SU). Methods This study integrates published data from several sources on characteristics of the CU and SU units in 11 hospitals in Ontario, Canada between 2005 and 2008. It proposes a two-layer wait time model (with each layer representing one unit) to examine the impact of CU's characteristics on the wait time of SU and test the hypotheses using the Partial Least Squares-based Structural Equation Modeling analysis tool. Results Results show that: (i) wait time of CU has a direct positive impact on wait time of SU (); (ii) capacity of CU has a direct positive impact on demand of SU (); (iii) within each unit, there exist significant relationships among different characteristics (except for the effect of throughput on wait time in SU). Conclusion Characteristics of CU have direct and indirect impacts on wait time of SU. Specifically, demand and wait time of preceding unit are good predictors for wait time of subsequent units. This suggests that considering such cross-unit effects is necessary when alleviating wait time in a health care system. Further, different patient risk profiles may affect wait time in different ways (e.g., positive or negative effects) within SU. This implies that the wait time management should carefully consider the relationship between priority triage and risk stratification, especially for cardiac surgery. PMID:21818282

  7. Summer-time thermal environment characteristics in central Korea using Landsat TM data

    NASA Astrophysics Data System (ADS)

    Park, Jin-Ki; Park, Jong-Hwa; Na, Sang-il

    2010-10-01

    Urban heat island(UHI) effect is the temperature increase in urban areas compared to that in surrounding rural areas and is caused by a number of factors, such as land use / land cover (LULC)change, increase fuel consumption and lack of vegetation in urban core areas. The replacement of natural surface types from soil and vegetation to impervious materials such as asphalt and concrete structures affects the albedo and runoff characteristics of the urban land surface. The impervious materials have a lower albedo than soil and vegetation and hold more solar energy, which increase land surface temperature (LST) during the summer season. UHI effects on the center region of South Korea were analyzed using remotely sensed data. The objectives of this study are to examine the summer-time thermal environment of the Cheongju city in Korea, review the satellite assessment of the thermal environment of LULC, and compare thermal environment in 1991 to 2006. Chang detection of thermal environment is performed to determine whether a significant change has occurred. The average of LST of study area has increased 2.7°C during 15years because of changed land cover from paddy field and forest to barren, factory, and concrete. This case study indicates that barren, factory, and residential apartment over on the Cheongju and Ochang increased in the late 1990s and that vegetation area are changing predominantly in the direction of decreased forest and paddy fields. Decreasing forest and paddy fields are an important result, as it suggests that directional changes are occurring on the Cheongju and Ochang that are consistent with experimental urban warming. The most influential factors for controlling the summer-time thermal environment are the distribution of surface cover characteristics (e.g. LULC) and urban morphology, such as urban consistence materials, geometry, development stage, and density.

  8. Characteristics of Real-Time, Non-Critical Incident Debriefing Practices in the Emergency Department

    PubMed Central

    Nadir, Nur-Ain; Bentley, Suzanne; Papanagnou, Dimitrios; Bajaj, Komal; Rinnert, Stephan; Sinert, Richard

    2017-01-01

    Introduction Benefits of post-simulation debriefings as an educational and feedback tool have been widely accepted for nearly a decade. Real-time, non-critical incident debriefing is similar to post-simulation debriefing; however, data on its practice in academic emergency departments (ED), is limited. Although tools such as TeamSTEPPS® (Team Strategies and Tools to Enhance Performance and Patient Safety) suggest debriefing after complicated medical situations, they do not teach debriefing skills suited to this purpose. Anecdotal evidence suggests that real-time debriefings (or non-critical incident debriefings) do in fact occur in academic EDs;, however, limited research has been performed on this subject. The objective of this study was to characterize real-time, non-critical incident debriefing practices in emergency medicine (EM). Methods We conducted this multicenter cross-sectional study of EM attendings and residents at four large, high-volume, academic EM residency programs in New York City. Questionnaire design was based on a Delphi panel and pilot testing with expert panel. We sought a convenience sample from a potential pool of approximately 300 physicians across the four sites with the goal of obtaining >100 responses. The survey was sent electronically to the four residency list-serves with a total of six monthly completion reminder emails. We collected all data electronically and anonymously using SurveyMonkey.com; the data were then entered into and analyzed with Microsoft Excel. Results The data elucidate various characteristics of current real-time debriefing trends in EM, including its definition, perceived benefits and barriers, as well as the variety of formats of debriefings currently being conducted. Conclusion This survey regarding the practice of real-time, non-critical incident debriefings in four major academic EM programs within New York City sheds light on three major, pertinent points: 1) real-time, non-critical incident debriefing

  9. Determinants of Timely Completion: The Impact of Bachelor's Degree Programme Characteristics and Student Motivation on Study Progress

    ERIC Educational Resources Information Center

    Suhre, Cor J. M.; Jansen, Ellen P. W. A.; Torenbeek, M.

    2013-01-01

    Timely completion of university degree programmes is a topic of growing concern to higher education institutions and their students. This paper reports on a study about the impact of degree programme characteristics and student motivation on study progress. The setting for the study is a Dutch law school. Data on degree programme characteristics,…

  10. Measurements of the Mechanisms of Laminar-Turbulent Transition in the Mach-6 Quiet Tunnel

    DTIC Science & Technology

    2012-02-28

    a highly polished nozzle with bleed slots for the contraction-wall boundary layer, and a large settling chamber with screens and sintered -mesh plates...2.628 m z = 2.679 m z = 2.730 m z = 2.781 m z = 2.831 m (b) Figure 5: Ensemble-averaged disturbances from spark perturbations, Re = 8.25×106/m; (a...z = 2.730 m; (c) z = 2.781 m; (d) z = 2.831 m. These measurements give a visualization of the growth and breakdown of spark -induced wave packets into

  11. Numerical investigation of laminar-turbulent transition in a flat plate wake

    NASA Technical Reports Server (NTRS)

    Fasel, Hermann F.; Newell, Alan C.; Dratler, David I.

    1990-01-01

    Lamina-turbulent transition of high-deficit flat plate wakes is investigated by direct numerical simulations using the complete Navier Stokes equations. The simulations are based on a spatial model so that both the base flow and the disturbance flow can develop in the downstream direction. The Navier Stokes equations are used in a vorticity-velocity form and are solved using a combination of finite difference and spectral approximations. Fourier series are used in the spanwise direction. Second-order finite-differences are used to approximate the spatial derivatives in the streamwise and transverse directions. For the temporal discretion, a combination of ADI, Crank-Nicolson, and Adams-Bashforth methods is employed. The discretized velocity equations are solved using fast Helmholtz solvers. Code validation is accomplished by comparison of the numerical results to both linear stability and to experiments. Calculations of two- and/or three-dimensional sinuous and mode disturbances in the wake of flat plate are undertaken. For calculations of two-dimensional disturbances, the wake is forced at an amplitude level so that nonlinear disturbance development may be observed. In addition, the forcing amplitude is varied in order to determine its effect on the disturbance behavior. To investigate the onset of three-dimensionality, the wake is forced with a small-amplitude three-dimensional disturbance and a larger amplitude two-dimensional disturbance. The two-dimensional forcing amplitude is varied in order to determine its influence on the three-dimensional flow field.

  12. Experimental study of the laminar-turbulent transition of a concave wall in a parallel flow

    NASA Technical Reports Server (NTRS)

    Bippes, H.

    1978-01-01

    The instability of the laminar boundary layer flow along a concave wall was studied. Observations of these three-dimensional boundary layer phenomena were made using the hydrogen-bubble visualization technique. With the application of stereo-photogrammetric methods in the air-water system it was possible to investigate the flow processes qualitatively and quantitatively. In the case of a concave wall of sufficient curvature, a primary instability occurs first in the form of Goertler vortices with wave lengths depending upon the boundary layer thickness and the wall curvature. At the onset the amplification rate is in agreement with the linear theory. Later, during the non-linear amplification stage, periodic spanwise vorticity concentrations develop in the low velocity region between the longitudinal vortices. Then a meandering motion of the longitudinal vortex streets subsequently ensues, leading to turbulence.

  13. Is there universal predator-prey dynamics at the laminar-turbulent phase transition?

    NASA Astrophysics Data System (ADS)

    Shih, Hong-Yan; Goldenfeld, Nigel

    2016-11-01

    Direct numerical simulation of pipe flow shows that transitional turbulence is dominated by two collective modes: a longitudinal mode for small-scale turbulent fluctuations whose anisotropy induces an emergent large-scale azimuthal mode (so-called zonal flow) that inhibits anisotropic Reynolds stress. This activation-inhibition interaction leads to stochastic predator-prey-like dynamics, from which it follows that the transition to turbulence belongs to the directed percolation universality class. Here we show how predator-prey dynamics arises by deriving phenomenologically an effective field theory of the transition from a coarse-graining of the Reynolds equation. The rigorous mapping between the conserved currents in Rayleigh-Benard convection (RBC), Taylor-Couette and pipe flows suggests that the zonal flow-turbulence scenario might occur in these systems, consistent with observations of zonal flows in two-dimensional RBC, and bursts of transitional turbulence in Couette flow that follow the critical scalings of directed percolation.

  14. DNS of Laminar-Turbulent Transition in Swept-Wing Boundary Layers

    NASA Technical Reports Server (NTRS)

    Duan, L.; Choudhari, M.; Li, F.

    2014-01-01

    Direct numerical simulation (DNS) is performed to examine laminar to turbulent transition due to high-frequency secondary instability of stationary crossflow vortices in a subsonic swept-wing boundary layer for a realistic natural-laminar-flow airfoil configuration. The secondary instability is introduced via inflow forcing and the mode selected for forcing corresponds to the most amplified secondary instability mode that, in this case, derives a majority of its growth from energy production mechanisms associated with the wall-normal shear of the stationary basic state. An inlet boundary condition is carefully designed to allow for accurate injection of instability wave modes and minimize acoustic reflections at numerical boundaries. Nonlinear parabolized stability equation (PSE) predictions compare well with the DNS in terms of modal amplitudes and modal shape during the strongly nonlinear phase of the secondary instability mode. During the transition process, the skin friction coefficient rises rather rapidly and the wall-shear distribution shows a sawtooth pattern that is analogous to the previously documented surface flow visualizations of transition due to stationary crossflow instability. Fully turbulent features are observed in the downstream region of the flow.

  15. An asymptotic analysis of the laminar-turbulent transition of yield stress fluids in pipes

    NASA Astrophysics Data System (ADS)

    Myers, Tim G.; Mitchell, Sarah L.; Slatter, Paul

    2017-02-01

    The work in this paper concerns the axisymmetric pipe flow of a Herschel-Bulkley fluid, with the aim of determining a relation between the critical velocity (defining the transition between laminar and turbulent flow) and the pipe diameter in terms of the Reynolds number Re 3. The asymptotic behaviour for large and small pipes is examined and simple expressions for the leading order terms are presented. Results are then compared with experimental data. A nonlinear regression analysis shows that for the tested fluids the transition occurs at similar values to the Newtonian case, namely in the range 2100 < Re 3 < 2500.

  16. On role of kinetic fluctuations in laminar-turbulent transition in chemically nonequilibrium boundary layer flows

    NASA Astrophysics Data System (ADS)

    Tumin, Anatoli

    2015-11-01

    Zavol'skii and Reutov (1983), Luchini (2008, 2010), Fedorov (2010, 2012, 2014) explored potential role of kinetic fluctuations (KF) in incompressible and calorically perfect gas boundary layer flows. The results indicate that role of KF is comparable with other disturbance sources in flight experiments and in quiet wind tunnels. The analysis is based on the Landau and Lifshitz (1957) concept of fluctuating hydrodynamics representing the dissipative fluxes as an average and fluctuating parts. We are extending analysis of the receptivity problem to the fluctuating dissipative fluxes in chemically reacting nonequilibrium boundary layer flows of binary mixtures. There are new terms in the energy, and the species equations. The species conservation equation includes the dissipative diffusion flux and the species generation due to dissociation. The momentum equation includes fluctuating stress tensor. The energy equation includes fluctuating heat flux, energy flux due to diffusion of the species, and fluctuating dissipative flux due to viscosity. The effects are compared for the cases stemming from constraints of the HTV project (Klentzman and Tumin, AIAA Paper 2013-2882). Supported by AFOSR.

  17. High-speed laminar-turbulent boundary layer transition induced by a discrete roughness element

    NASA Astrophysics Data System (ADS)

    Iyer, Prahladh; Mahesh, Krishnan

    2013-11-01

    Direct numerical simulation (DNS) is used to study laminar to turbulent transition induced by a discrete hemispherical roughness element in a high-speed laminar boundary layer. The simulations are performed under conditions matching the experiments of Danehy et al. (AIAA Paper 2009-394, 2009) for free-stream Mach numbers of 3.37, 5.26 and 8.23. It is observed that the Mach 8.23 flow remains laminar downstream of the roughness, while the lower Mach numbers undergo transition. The Mach 3.37 flow undergoes transition closer to the bump when compared with Mach 5.26, in agreement with experimental observations. Transition is accompanied by an increase in Cf and Ch (Stanton number). Even for the case that did not undergo transition (Mach 8.23), streamwise vortices induced by the roughness cause a significant rise in Cf until 20 D downstream. The mean van Driest transformed velocity and Reynolds stress for Mach 3.37 and 5.26 show good agreement with available data. A local Reynolds number based on the wall properties is seen to correlate with the onset of transition for the cases considered. Partially supported by NASA.

  18. Large-Eddy Simulation of Laminar-Turbulent Transition in a Swept-Wing Boundary Layer

    NASA Technical Reports Server (NTRS)

    Huai, X.; Joslin, R. D.; Piomelli, U.

    2004-01-01

    A continuous adjoint approach for obtaining sensitivity derivatives on unstructured grids is developed and analyzed. The derivation of the costate equations is presented, and a second-order accurate discretization method is described. The relationship between the continuous formulation and a discrete formulation is explored for inviscid, as well as for viscous flow. Several limitations in a strict adherence to the continuous approach are uncovered, and an approach that circumvents these difficulties is presented. The issue of grid sensitivities, which do not arise naturally in the continuous formulation, is investigated and is observed to be of importance when dealing with geometric singularities. A method is described for modifying inviscid and viscous meshes during the design cycle to accommodate changes in the surface shape. The accuracy of the sensitivity derivatives is established by comparing with finite-difference gradients and several design examples are presented.

  19. Time-motion analysis, heart rate, and physiological characteristics of international canoe polo athletes.

    PubMed

    Forbes, Scott C; Kennedy, Michael D; Bell, Gordon J

    2013-10-01

    To evaluate the time international canoe polo players spend performing various game activities, measure heart rate (HR) responses during games, and describe the physiological profile of elite players. Eight national canoe polo players were videotaped and wore HR monitors during 3 games at a World Championship and underwent fitness testing. The mean age, height, and weight were 25 ± 1 years, 1.82 ± 0.04 m, and 81.9 ± 10.9 kg, respectively. Time-motion analysis of 3 games indicated that the players spent 29 ± 3% of the game slow and moderate forward paddling, 28 ± 5% contesting, 27 ± 5% resting and gliding, 7 ± 1% turning, 5 ± 1% backward paddling, 2 ± 1% sprinting, and 2 ± 1% dribbling. Sixty-nine (±20)% of the game time was played at an HR intensity above the HR that corresponded to the ventilatory threshold (VT) that was determined during the peak V[Combining Dot Above]O2 test. Peak oxygen uptake and VT were 3.3 ± 0.3 and 2.2 ± 0.3 L·min, respectively, on a modified Monark arm crank ergometer. Arm crank peak 5-second anaerobic power was 379 W. The majority of the time spent during international canoe polo games involved slow-to-moderate forward paddling, contesting for the ball, and resting and gliding. Canoe polo games are played at a high intensity indicated by the HR responses, and the physiological characteristics suggest that these athletes had high levels of upper body aerobic and anaerobic fitness levels.

  20. Time-varying spectral characteristics of ENSO over the Last Millennium

    NASA Astrophysics Data System (ADS)

    Hope, Pandora; Henley, Benjamin J.; Gergis, Joelle; Brown, Josephine; Ye, Hua

    2016-10-01

    The characteristics of El Nino-Southern Oscillation (ENSO) spectra over the Last Millennium are examined to characterise variability over past centuries. Seven published palaeo-ENSO reconstructions and Nino3.4 from six Coupled Model Intercomparison Project-Phase 5 and Paleoclimate Modelling Intercomparison Project-Phase 3 (CMIP5-PMIP3) Last Millennium simulations were analysed. The corresponding Historical and pre-industrial Control CMIP5-PMIP3 simulations were also considered. The post-1850 spectrum of each modelled or reconstructed ENSO series captures aspects of the observed spectrum to varying degrees. We note that no single model or ENSO reconstruction completely reproduces the instrumental spectral characteristics. The spectral power across the 2-3 years (near biennial), 3-8 years (classical ENSO) and 8-25 years (decadal) periodicity bands was calculated in a sliding 50 year window, revealing temporal variability in the spectra. There was strong temporal variability in the spectral power of each periodicity band in observed Nino3.4 and SOI and for all reconstructions and simulations of ENSO. Significant peaks in spectral power such as observed in recent decades also occur in some of the reconstructed palaeo-ENSO (around 1600, the early 1700s and 1900) and modelled series (around the major volcanic eruptions of 1258 and 1452). While the recent increase in spectral power might be in response to enhanced greenhouse gas levels, the increase lies within the range of variability across the suite of ENSO reconstructions and simulations examined here. This study demonstrates that the analysis of a suite of ENSO reconstructions and model simulations can build a broader understanding of the time-varying nature of ENSO spectra, and how the nature of the past spectra of ENSO is to some extent dependant on the climate model or palaeo-ENSO reconstruction chosen.

  1. Investigation of hydrological time series using copulas for detecting catchment characteristics and anthropogenic impacts

    NASA Astrophysics Data System (ADS)

    Sugimoto, Takayuki; Bárdossy, András; Pegram, Geoffrey G. S.; Cullmann, Johannes

    2016-07-01

    Global climate change can have impacts on characteristics of rainfall-runoff events and subsequently on the hydrological regime. Meanwhile, the catchment itself changes due to anthropogenic influences. However, it is not easy to prove the link between the hydrology and the forcings. In this context, it might be meaningful to detect the temporal changes of catchments independent from climate change by investigating existing long-term discharge records. For this purpose, a new stochastic system based on copulas for time series analysis is introduced in this study.A statistical tool like copula has the advantage to scrutinize the dependence structure of the data and, thus, can be used to attribute the catchment behavior by focusing on the following aspects of the statistics defined in the copula domain: (1) copula asymmetry, which can capture the nonsymmetric property of discharge data, differs from one catchment to another due to the intrinsic nature of both runoff and catchment; and (2) copula distances can assist in identifying catchment change by revealing the variability and interdependency of dependence structures.These measures were calculated for 100 years of daily discharges for the Rhine River and these analyses detected epochs of change in the flow sequences. In a follow-up study, we compared the results of copula asymmetry and copula distance applied to two flow models: (i) antecedent precipitation index (API) and (ii) simulated discharge time series generated by a hydrological model. The results of copula-based analysis of hydrological time series seem to support the assumption that the Neckar catchment had started to change around 1976 and stayed unusual until 1990.

  2. Neighborhood contextual characteristics and leisure-time physical activity: Pró-Saúde Study

    PubMed Central

    Boclin, Karine de Lima Sírio; Faerstein, Eduardo; de Leon, Antônio Carlos Monteiro Ponce

    2014-01-01

    OBJECTIVE To estimate the association between neighborhood contextual variables and leisure-time physical activity. METHODS Data were analyzed for 2,674 adults from Rio de Janeiro, RJ, Southeastern Brazil, participating in the longitudinal study in 1999. Leisure-time physical activity in the two preceding weeks was assessed dichotomously. Sex, age, income, education and marital status were analyzed as individual variables. Neighborhood contextual characteristics were the social development index, the Theil index and the proportion of the area occupied by parks, squares and gardens, categorized in quintiles. The unadjusted and adjusted odds ratios and 95% confidence intervals were estimated using multilevel logistic regression. RESULTS The prevalence of leisure-time physical activity was higher in residents in neighborhoods with higher indices of social development (between 32.3% and 53.1%) and a greater proportion of parks, squares and gardens (between 35.8% and 53.1%). Regarding the social development index, the adjusted odds ratios for physical activity were 1.22 (95%CI 0.93;1.61), 1.44 (95%CI 1.09;1.89), 1.75 (95%CI 1.31;2.34) and 2.25 (95%CI 1.70;3.00) for residents in neighborhoods in the second, third, fourth and fifth quintiles, respectively, compared with residents in neighborhoods in the first quintile. The odds ratios for the proportion of parks, squares and gardens were 0.90 (95%CI 0.69;1.19), 1.41 (95%CI 1.04;1.90), 1.63 (95%CI 1.24;2.14) and 1.05 (95%CI 0.80;1.38) for residents in neighborhoods in the second, third, fourth and fifth quintiles. After adjusting for the other variables, only the social development index continued to be associated with leisure-time physical activity, with odds ratios of 1.41 (95%CI 1.02;1.95); 1.54 (95%CI 1.12;2.12); 1.65 (95%CI 1.14;2.39) and 2.13 (95%CI 1.40;3.25) for residents in neighborhoods in the second, third, fourth and fifth quintiles. CONCLUSIONS Leisure-time physical activity was more common in residents in

  3. Evaluation of the amperex 56 TVP photomultiplier. [characteristics: photoelectron time spread, anode pulse amplitude and photocathode sensing area

    NASA Technical Reports Server (NTRS)

    Lo, C. C.; Leskovar, B.

    1976-01-01

    Characteristics were measured for the Amperex 56 TVP 42 mm-diameter photomultiplier. Some typical photomultiplier characteristics-such as gain, dark current, transit and rise times-are compared with data provided. Photomultiplier characteristics generally not available such as the single photoelectron time spread, the relative collection efficiency, the relative anode pulse amplitude as a function of the voltage between the photocathode and focusing electrode, and the position of the photocathode sensing area were measured and are discussed for two 56 TVP's. The single photoelectron time spread, the relative collection efficiency, and the transit time difference as a function of the voltage between photocathode and focusing electrode were also measured and are discussed, particularly with respect to the optimization of photomultiplier operating conditions for timing applications.

  4. As time goes by: reasons and characteristics of prolonged episodes of mechanical restraint in forensic psychiatry.

    PubMed

    Gildberg, Frederik A; Fristed, Peter; Makransky, Guido; Moeller, Elsebeth H; Nielsen, Lea D; Bradley, Stephen K

    2015-01-01

    Evidence suggests the prevalence and duration of mechanical restraint are particularly high among forensic psychiatric inpatients. However, only sparse knowledge exists regarding the reasons for, and characteristics of, prolonged use of mechanical restraint in forensic psychiatry. This study therefore aimed to investigate prolonged episodes of mechanical restraint on forensic psychiatric inpatients. Documentary data from medical records were thematically analyzed. Results show that the reasons for prolonged episodes of mechanical restraint on forensic psychiatric inpatients can be characterized by multiple factors: "confounding" (behaviors associated with psychiatric conditions, substance abuse, medical noncompliance, etc.), "risk" (behaviors posing a risk for violence), and "alliance parameters" (qualities of the staff-patient alliance and the patients' openness to alliance with staff), altogether woven into a mechanical restraint spiral that in itself becomes a reason for prolonged mechanical restraint. The study also shows lack of consistent clinical assessment during periods of restraint. Further investigation is indicated to develop an assessment tool with the capability to reduce time spent in mechanical restraint.

  5. Incidence, clinical characteristics, and timing of objectively diagnosed venous thromboembolism during pregnancy.

    PubMed

    Gherman; Goodwin; Leung; Byrne; Montoro

    1998-07-01

    Objective: To determine the incidence, timing, and associated clinical characteristics of objectively diagnosed pregnancy-associated venous thromboembolism (VTE).Methods: A retrospective review of VTE cases occurring between 1978 and 1996 was performed. Cases of deep venous thrombosis (DVT) and pulmonary embolism (PE) were identified by ICD-9 discharge diagnosis code and review of antepartum and coagulation laboratory databases. Study inclusion criteria required the objective diagnosis of VTE with either Doppler ultrasound, impedance plethysmography, pulmonary angiography, ventilation-perfusion scanning, or CT/MRI.Results: Among 268,525 deliveries there were 165 (0.06%) episodes of VTE (1/1627 births). There were 127 cases of DVT and 38 cases of PE. Only 14% (23/165) had a prior history of DVT or PE. Most DVTs occurred in the left leg (104/127, 81.9%). Nearly three quarters of the DVTs (95/127, 74.8%) occurred in the antepartum period. Among the antepartum DVT cases, half were detected prior to 15 weeks of gestation (47/95, 49.5%), with only 28 cases occurring after 20 weeks (P <.0001). The majority of the PEs occurred in the postpartum period (23/38, 60.5%). There were only 3 maternal deaths due to PE, all associated with cesarean section. Only 1 patient developed PE while on heparin therapy for DVT while 11 others had complications attributable to heparin use.Conclusion: Most pregnancy-related VTE occurs in the antepartum period. The risk of deep venous thrombosis appears to begin early in pregnancy, even before the second trimester. The highest risk period for pulmonary embolism is after cesarean delivery. Maternal complications of heparin anticoagulation during pregnancy are rare.

  6. Spatial gravity wave characteristics obtained from multiple OH(3-1) airglow temperature time series

    NASA Astrophysics Data System (ADS)

    Wachter, Paul; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael

    2015-12-01

    We present a new approach for the detection of gravity waves in OH-airglow observations at the measurement site Oberpfaffenhofen (11.27°E, 48.08°N), Germany. The measurements were performed at the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) during the period from February 4th, 2011 to July 6th, 2011. In this case study the observations were carried out by three identical Ground-based Infrared P-branch Spectrometers (GRIPS). These instruments provide OH(3-1) rotational temperature time series, which enable spatio-temporal investigations of gravity wave characteristics in the mesopause region. The instruments were aligned in such a way that their fields of view (FOV) formed an equilateral triangle in the OH-emission layer at a height of 87 km. The Harmonic Analysis is applied in order to identify joint temperature oscillations in the three individual datasets. Dependent on the specific gravity wave activity in a single night, it is possible to detect up to four different wave patterns with this method. The values obtained for the waves' periods and phases are then used to derive further parameters, such as horizontal wavelength, phase velocity and the direction of propagation. We identify systematic relationships between periods and amplitudes as well as between periods and horizontal wavelengths. A predominant propagation direction towards the East and North-North-East characterizes the waves during the observation period. There are also indications of seasonal effects in the temporal development of the horizontal wavelength and the phase velocity. During late winter and early spring the derived horizontal wavelengths and the phase velocities are smaller than in the subsequent period from early April to July 2011.

  7. Assessing the Value of Regulation Resources Based on Their Time Response Characteristics

    SciTech Connect

    Makarov, Yuri V.; Lu, Shuai; Ma, Jian; Nguyen, Tony B.

    2008-06-01

    Fast responsive regulation resources are potentially more valuable as a power system regulation resource (more efficient) because they allow applying controls at the exact moment and in the exact amount as needed. Faster control is desirable because it facilitates more reliable compliance with the NERC Control Performance Standards at relatively lesser regulation capacity procurements. The current California ISO practices and markets do not provide a differentiation among the regulation resources based on their speed of response (with the exception of some minimum ramping capabilities). Some demand response technologies, including some generation and energy storage resources, can provide quicker control actions. California ISO practices and markets could be updated to welcome more fast regulation resources into the California ISO service area. The project work reported in this work was pursuing the following objectives: • Develop methodology to assess the relative value of generation resources used for regulation and load following California ISO functions • This assessment should be done based on physical characteristics including the ability to quickly change their output following California ISO signals • Evaluate what power is worth on different time scales • Analyze the benefits of new regulation resources to provide effective compliance with the mandatory NERC Control Performance Standards • Evaluate impacts of the newly proposed BAAL and FRR standards on the potential value of fast regulation and distributed regulation resources • Develop a scope for the follow-up projects to pave a road for the new efficient types of balancing resources in California. The work included the following studies: • Analysis of California ISO regulating units characteristics • California ISO automatic generation system (AGC) analysis • California ISO regulation procurement and market analysis • Fast regulation efficiency analysis • Projection of the

  8. Characteristics and sensitivity analysis of multiple-time-resolved source patterns of PM2.5 with real time data using Multilinear Engine 2

    NASA Astrophysics Data System (ADS)

    Peng, Xing; Shi, Guo-Liang; Gao, Jian; Liu, Jia-Yuan; HuangFu, Yan-Qi; Ma, Tong; Wang, Hai-Ting; Zhang, Yue-Chong; Wang, Han; Li, Hui; Ivey, Cesunica E.; Feng, Yin-Chang

    2016-08-01

    With real time resolved data of Particulate matter (PM) and chemical species, understanding the source patterns and chemical characteristics is critical to establish controlling of PM. In this work, PM2.5 and chemical species were measured by corresponding online instruments with 1-h time resolution in Beijing. Multilinear Engine 2 (ME2) model was applied to explore the sources, and four sources (vehicle emission, crustal dust, secondary formation and coal combustion) were identified. To investigate the sensitivity of time resolution on the source contributions and chemical characteristics, ME2 was conducted with four time resolution runs (1-h, 2-h, 4-h, and 8-h). Crustal dust and coal combustion display large variation in the four time resolutions runs, with their contributions ranging from 6.7 to 10.4 μg m-3 and from 6.4 to 12.2 μg m-3, respectively. The contributions of vehicle emission and secondary formation range from 7.5 to 10.5 and from 14.7 to 16.7 μg m-3, respectively. The sensitivity analyses were conducted by principal component analysis-plot (PCA-plot), coefficient of divergence (CD), average absolute error (AAE) and correlation coefficients. For the four time resolution runs, the source contributions and profiles of crustal dust and coal combustion were more unstable than other source categories, possibly due to the lack of key markers of crustal dust and coal combustion (e.g. Si, Al). On the other hand, vehicle emission and crustal dust were more sensitive to time series of source contributions at different time resolutions. Findings in this study can improve our knowledge of source contributions and chemical characteristics at different time solutions.

  9. A comparison of catch phase force-time characteristics during clean derivatives from the knee.

    PubMed

    Comfort, Paul; Williams, Robert; Suchomel, Timothy J; Lake, Jason P

    2016-09-27

    The aim of this study was to compare load-absorption force-time characteristics of the clean from the knee (CK), power clean from the knee (PCK) and clean pull from the knee (CPK). Ten collegiate athletes (age 27.5 ± 4.2 years; height 180.4 ± 6.7 cm; mass 84.4 ± 7.8 kg), performed three repetitions each of the CK, PCK and CPK with 90% of their 1RM power clean on a force platform. The CK load-absorption duration (0.95 ± 0.35 s) was significantly longer compared to the CPK (0.44 ± 0.15 s; p < 0.001, d = 2.53), but not compared to the PCK (0.56 ± 0.11 s; p > 0.05, d = 1.08), with no differences between PCK and CPK (p > 0.05, d = 0.91). The CPK demonstrated the greatest mean force (2039 ± 394 N), which was significantly greater than the PCK (1771 ± 325 N; p = 0.012, d = 0.83), but not significantly different to the CK (1830 ± 331 N; p > 0.05, d = 0.60); CK and PCK were not different (p > 0.05, d = 0.18). Significantly more load-absorption work was performed during the CK (655 ± 276 J) compared to the PCK (288 ± 109 J; d = 1.75, p < 0.001); but not compared to the CPK (518 ± 132 J; d = 0.80, p > 0.05). Additionally, more load-absorption work was performed during the CPK compared to the PCK (d = 1.90, p = 0.032). Inclusion of the catch phase during the CK does not provide any additional stimulus in terms of mean force or work during the load-absorption phase compared to the CPK, while the CPK may be beneficial in training rapid force absorption due to high force and a short duration.

  10. [Research on Time-frequency Characteristics of Magneto-acoustic Signal of Different Thickness Medium Based on Wave Summing Method].

    PubMed

    Zhang, Shunqi; Yin, Tao; Ma, Ren; Liu, Zhipeng

    2015-08-01

    Functional imaging method of biological electrical characteristics based on magneto-acoustic effect gives valuable information of tissue in early tumor diagnosis, therein time and frequency characteristics analysis of magneto-acoustic signal is important in image reconstruction. This paper proposes wave summing method based on Green function solution for acoustic source of magneto-acoustic effect. Simulations and analysis under quasi 1D transmission condition are carried out to time and frequency characteristics of magneto-acoustic signal of models with different thickness. Simulation results of magneto-acoustic signal were verified through experiments. Results of the simulation with different thickness showed that time-frequency characteristics of magneto-acoustic signal reflected thickness of sample. Thin sample, which is less than one wavelength of pulse, and thick sample, which is larger than one wavelength, showed different summed waveform and frequency characteristics, due to difference of summing thickness. Experimental results verified theoretical analysis and simulation results. This research has laid a foundation for acoustic source and conductivity reconstruction to the medium with different thickness in magneto-acoustic imaging.

  11. Quality characteristics of a dry-cured lamb leg as affected by tumbling after dry-salting and processing time.

    PubMed

    Villalobos-Delgado, Luz H; Caro, Irma; Blanco, Carolina; Morán, Lara; Prieto, Nuria; Bodas, Raul; Giráldez, Francisco J; Mateo, Javier

    2014-05-01

    The aim of this study was to evaluate selected quality characteristics of a dry-cured lamb leg with different tumbling treatments after salting. The characteristics were measured at different processing times. Three batches of dry-cured lamb legs (nine legs per batch) were prepared with no-, short- and long-tumbling treatments, and microbial counts, NaCl, aw, proximate composition, pH, free fatty acids, water soluble nitrogen, volatile compounds, texture and colour were evaluated at days 1, 22 and 71 of processing. Furthermore, a descriptive sensory analysis (flavour and texture) was performed in the final product (day 71). Time-related changes were observed for most of the characteristics studied. The effect of tumbling was only observed for the sensory attribute pastiness that was higher in tumbled legs. Methyl-branched butanal was only detected in tumbled legs.

  12. Metrological characteristics of the flat voltammetric electrode in time domain with a reversible electrochemical reaction running on the surface

    NASA Astrophysics Data System (ADS)

    Suchocki, Krzysztof

    2016-11-01

    The study deals with metrological characteristics of the flat voltammetric electrode used for determination of ions concentration by the DC voltammetric method, where a reversible reaction of electrochemical oxidation/reduction takes place on the surface. The analysis shows that such voltammetric electrode acts as a transducer of the first order, where the input signal is a concentration of marked ions in tested solution and the output signal is the current associated with a reversible reaction of oxidation / reduction. Metrological characteristics of such electrode in the time domain are determined by its sensitivity and time constant. The values of these parameters are defined by measurements of characteristics of the voltammetric electrode, polarization voltage and marked ions. To determine the effect of a particular volume of each of these parameters several numerical simulations are presented.

  13. Nurse Staffing and Hospital Characteristics Predictive of Time to Diagnostic Evaluation for Patients in the Emergency Department.

    PubMed

    Shindul-Rothschild, Judith; Read, Catherine Y; Stamp, Kelly D; Flanagan, Jane

    2016-10-20

    In the 2014 Emergency Department Benchmarking Alliance Summit, for the first time, participants recommended tracking nursing and advanced practice nurse hours. Performance data from the Centers for Medicare and Medicaid Services provides an opportunity to analyze factors associated with delays in emergency care. The purpose of this study was to investigate hospital characteristics associated with time to a diagnostic evaluation in 67 Massachusetts emergency departments from 2013 to 2014.

  14. Do Participants Differ in Their Cognitive Abilities, Task Motivation, or Personality Characteristics as a Function of Time of Participation?

    ERIC Educational Resources Information Center

    Robison, Matthew K.; Unsworth, Nash

    2016-01-01

    Four experiments tested the conventional wisdom in experimental psychology that participants who complete laboratory tasks systematically differ in their cognitive abilities, motivational levels, and personality characteristics as a function of the time at which they participate during an academic term. Across 4 experiments with over 2,900…

  15. English Learner Student Characteristics and Time to Reclassification: An Example from Washington State. REL 2016-128

    ERIC Educational Resources Information Center

    Greenberg Motamedi, Jason; Singh, Malkeet; Thompson, Karen D.

    2016-01-01

    How long does it typically take English learner students to develop English language proficiency? And how does this time vary by student characteristics such as English proficiency at entry to kindergarten, gender, and home language? The answers to these questions can provide valuable information to districts and schools. Regional Educational…

  16. Spectral and amplitude-time characteristics of radiation of plasma of a repetitively pulsed discharge initiated by runaway electrons

    NASA Astrophysics Data System (ADS)

    Lomaev, M. I.; Beloplotov, D. V.; Sorokin, D. A.; Tarasenko, V. F.

    2016-02-01

    Spectral and amplitude-time characteristics of radiation of plasma of a repetitively pulsed discharge initiated by runaway electrons were studied experimentally in nitrogen. Intense emission lines of copper atoms, nitrogen atoms, and ions, as well as the first and the second positive systems of nitrogen, NO, and CN, were observed in the regime of repetitively pulsed excitation.

  17. Are Middle Schools Harmful? The Role of Transition Timing, Classroom Quality and School Characteristics

    ERIC Educational Resources Information Center

    Holas, Igor; Huston, Aletha C.

    2012-01-01

    Are middle schools ill-suited for early adolescents, or can school characteristics account for any differences in student functioning? Achievement, school engagement, and perceived competence of children starting middle schools in 5th and 6th grades were compared to those of their same-grade peers in elementary schools in a national, longitudinal…

  18. Selective Influence of Circadian Modulation and Task Characteristics on Motor Imagery Time

    ERIC Educational Resources Information Center

    Debarnot, Ursula; Sahraoui, Djafar; Champely, Stephane; Collet, Christian; Guillot, Aymeric

    2012-01-01

    In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no…

  19. Hawaii PTTI test bed. [characteristics and operation on time measurement facility

    NASA Technical Reports Server (NTRS)

    Murray, J. A.

    1972-01-01

    The development and installation of a test bed for a Precise Time and Time Interval (PTTI). A prime goal in the effort is to develop a repertoire of techniques and equipment that will permit communications facilities to be served most effectively by their ties to a common time reference. The test bed provides guidance for the implementation of precise time and frequency discipline at other facilities. One product of the test-bed problem is an assessment of the accuracy of the time-discipline chain from the observatory to each level of use.

  20. Differentiating Blood, Lymph, and Primo Vessels by Residual Time Characteristic of Fluorescent Nanoparticles in a Tumor Model

    PubMed Central

    Lee, Sungwoo; Lim, Jaekwan; Cha, Jinmyung; Lee, Jin-Kyu; Ryu, Yeon Hee; Kim, SungChul; Soh, Kwang-Sup

    2013-01-01

    Fluorescent nanoparticles (FNPs) which were injected into a tumor tissue flowed out through the blood and lymph vessels. The FNPs in blood vessels remained only in the order for few minutes while those in lymph vessels remained for a long time disappearing completely in 25 hours. We found a primo vessel inside a lymph vessel near a blood vessel, and FNPs remained in the primo vessel for longer than 25 hours. In addition, we examined in detail the residual time characteristics of lymph vessels because it could be useful in a future study of fluid dynamical comparison of the three conduits. These residual time characteristics of FNPs in the three kinds of vessels may have implications for the dynamics of nanoparticle drugs for cancer chemotherapy. PMID:23662147

  1. On a distinctive feature of problems of calculating time-average characteristics of nuclear reactor optimal control sets

    NASA Astrophysics Data System (ADS)

    Trifonenkov, A. V.; Trifonenkov, V. P.

    2017-01-01

    This article deals with a feature of problems of calculating time-average characteristics of nuclear reactor optimal control sets. The operation of a nuclear reactor during threatened period is considered. The optimal control search problem is analysed. The xenon poisoning causes limitations on the variety of statements of the problem of calculating time-average characteristics of a set of optimal reactor power off controls. The level of xenon poisoning is limited. There is a problem of choosing an appropriate segment of the time axis to ensure that optimal control problem is consistent. Two procedures of estimation of the duration of this segment are considered. Two estimations as functions of the xenon limitation were plot. Boundaries of the interval of averaging are defined more precisely.

  2. Characteristic time scales of coalescence of silver nanocomposite and nanoparticle films induced by continuous wave laser irradiation

    SciTech Connect

    Paeng, Dongwoo; Grigoropoulos, Costas P.; Lee, Daeho

    2014-08-18

    In-situ optical probing has been performed to analyze and compare the characteristic coalescence time scales of silver ion-doped polyvinylalcohol nanocomposite (Ag-PVA NC) and polyvinylpyrrolidone-capped silver nanoparticle (Ag-PVP NP) films subjected to continuous wave laser irradiation. The Ag-PVA NC yielded conductive metallic patterns by photothermal reduction of PVA, formation of nanoparticles from silver ions and their subsequent coalescence. On the other hand, Ag-PVP NP thin films produced conductive patterns through only coalescence of nanoparticles. Upon laser irradiation, Ag-PVA NC and Ag-PVP NP films exhibited different coalescence characteristics.

  3. Are middle schools harmful? The role of transition timing, classroom quality and school characteristics.

    PubMed

    Holas, Igor; Huston, Aletha C

    2012-03-01

    Are middle schools ill-suited for early adolescents, or can school characteristics account for any differences in student functioning? Achievement, school engagement, and perceived competence of children starting middle schools in 5th and 6th grades were compared to those of their same-grade peers in elementary schools in a national, longitudinal sample (NICHD Study of Early Child Care and Youth Development, n = 855; 52% Female, 82% White). Classroom quality (observed and teacher-reported) and school characteristics (composition and size) were considered as explanations for any relationships between school-level and student functioning. Fifth grade middle school students did not differ from those in elementary school, but students entering middle school in 6th grade, compared to those in elementary school, experienced lower classroom quality, which in turn predicted slightly lower achievement. They also had lower school engagement, explained by larger school size. Classroom quality and school characteristics predicted youth functioning regardless of school type. We suggest reshaping the research and policy debate with renewed focus on classroom quality and school size instead of grade organization.

  4. The effect of quantity and timing of brine addition on water binding and textural characteristics of cooked beef rolls.

    PubMed

    Pietrasik, Z; Shand, P J

    2003-10-01

    The combined influence of quantity and timing of water/sodium chloride/phosphate addition on quality characteristics of beef rolls processed with 25 or 50% brine level was investigated. Properties of beef rolls were determined by measuring hydration and textural characteristics. The higher level of brine addition (50%) had detrimental effects on product water binding and textural characteristics. Late addition of brine/water during tumbling (i.e. during the last hour) resulted in rolls which were less hard, chewy and elastic, and had poorer water holding properties. Addition of brine in two parts favourably affected hydration properties and thermal stability, yielding lower cooking loss and purge and higher WHC, irrespective of level of brine addition. It also increased hardness and chewiness and improved springiness, cohesiveness and bind of cooked beef rolls.

  5. Sex and Racial/Ethnic Characteristics of Full-Time Vocational Education Instructional Staff.

    ERIC Educational Resources Information Center

    National Center for Education Statistics Bulletin, 1982

    1982-01-01

    Men dominated the teaching positions in five of nine vocational program areas during 1979-80: industrial-arts (96.6 percent of full time positions), agriculture (93.5 percent), technical (92.8 percent), trade and industrial (91.4 percent), and distribution (69.5 percent) according to a survey of 282,292 full time instructional staff analyzed…

  6. Part Time Faculty: A Comparative Profile of Characteristics and Effectiveness at Corning Community College.

    ERIC Educational Resources Information Center

    Turgeon, Mary L.

    A study was conducted at Corning Community College (CCC) to develop profiles of full- and part-time faculty based on survey data and student evaluations. All full- and part-time faculty who taught credit courses during the 1982-83 academic year were surveyed and requested to permit the use of their student evaluations as part of their aggregate…

  7. Characteristic time-stepping or local preconditioning of the Euler equations

    NASA Technical Reports Server (NTRS)

    Van Leer, Bram; Lee, Wen-Tzong; Roe, Philip L.

    1991-01-01

    A derivation is presented of a local preconditioning matrix for multidimensional Euler equations, that reduces the spread of the characteristic speeds to the lowest attainable value. Numerical experiments with this preconditioning matrix are applied to an explicit upwind discretization of the two-dimensional Euler equations, showing that this matrix significantly increases the rate of convergence to a steady solution. It is predicted that local preconditioning will also simplify convergence-acceleration boundary procedures such as the Karni (1991) procedure for the far field and the Mazaheri and Roe (1991) procedure for a solid wall.

  8. Correlation Analyses Between the Characteristic Times of Gradual Solar Energetic Particle Events and the Properties of Associated Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Pan, Z. H.; Wang, C. B.; Wang, Yuming; Xue, X. H.

    2011-06-01

    It is generally believed that gradual solar energetic particles (SEPs) are accelerated by shocks associated with coronal mass ejections (CMEs). Using an ice-cream cone model, the radial speed and angular width of 95 CMEs associated with SEP events during 1998 - 2002 are calculated from SOHO/LASCO observations. Then, we investigate the relationships between the kinematic properties of these CMEs and the characteristic times of the intensity-time profile of their accompanied SEP events observed at 1 AU. These characteristic times of SEP are i) the onset time from the accompanying CME eruption at the Sun to the SEP arrival at 1 AU, ii) the rise time from the SEP onset to the time when the SEP intensity is one-half of peak intensity, and iii) the duration over which the SEP intensity is within a factor of two of the peak intensity. It is found that the onset time has neither significant correlation with the radial speed nor with the angular width of the accompanying CME. For events that are poorly connected to the Earth, the SEP rise time and duration have no significant correlation with the radial speed and angular width of the associated CMEs. However, for events that are magnetically well connected to the Earth, the SEP rise time and duration have significantly positive correlations with the radial speed and angular width of the associated CMEs. This indicates that a CME event with wider angular width and higher speed may more easily drive a strong and wide shock near to the Earth-connected interplanetary magnetic field lines, may trap and accelerate particles for a longer time, and may lead to longer rise time and duration of the ensuing SEP event.

  9. Selective influence of circadian modulation and task characteristics on motor imagery time.

    PubMed

    Debarnot, Ursula; Sahraoui, Djafar; Champely, Stéphane; Collet, Christian; Guillot, Aymeric

    2012-09-01

    In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no effect of circadian rhythm in the complex, short or long walking conditions. We concluded that motor imagery time is modulated during the course of the day, but the effect of task difficulty is stronger than circadian modulation in altering the temporal congruence between physical practice and MI performance. Practical applications in motor learning and rehabilitation are discussed.

  10. Operational characteristics of single-particle heat engines and refrigerators with time-asymmetric protocol

    NASA Astrophysics Data System (ADS)

    Pal, P. S.; Saha, Arnab; Jayannavar, A. M.

    2016-09-01

    We have studied the single-particle heat engine and refrigerator driven by time-asymmetric protocol of finite duration. Our system consists of a particle in a harmonic trap with time-periodic strength that drives the particle cyclically between two baths. Each cycle consists of two isothermal steps at different temperatures and two adiabatic steps connecting them. The system works in irreversible mode of operation even in the quasistatic regime. This is indicated by finite entropy production even in the large cycle time limit. Consequently, Carnot efficiency for heat engine or Carnot coefficient of performance (COP) for refrigerators is not achievable. We further analyzed the phase diagram of heat engines and refrigerators. They are sensitive to time-asymmetry of the protocol. Phase diagram shows several interesting features, often counterintuitive. The distribution of stochastic efficiency and COP is broad and exhibits power-law tails.

  11. Muscle Activation Characteristics of the Front Leg During Baseball Swings with Timing Correction for Sudden Velocity Decrease

    PubMed Central

    Ohta, Yoichi; Nakamoto, Hiroki; Ishii, Yasumitsu; Ikudome, Sachi; Takahashi, Kyohei; Shima, Norihiro

    2015-01-01

    This study aimed to clarify the activation characteristics of the vastus lateralis muscle in the front leg during timing correction for a sudden decrease in the velocity of a target during baseball swings. Eleven male collegiate baseball players performed coincident timing tasks that comprised constant velocity of 8 m/s (unchanged) and a sudden decrease in velocity from 8 to 4 m/s (decreased velocity). Electromyography (EMG) revealed that the muscle activation was typically monophasic when responding unchanged conditions. The type of muscle activation during swings in response to decreased velocity condition was both monophasic and biphasic. When biphasic activation appeared in response to decreased velocity, the impact time and the time to peak EMG amplitude were significantly prolonged and the timing error was significantly smaller than that of monophasic activation. However, the EMG onset from the target start was consistent both monophasic and biphasic activation in response to conditions of decreased velocity. In addition, batters with small timing errors in response to decreased velocity were more likely to generate biphasic EMG activation. These findings indicated that timing correction for a sudden decrease in the velocity of an oncoming target is achieved by modifying the muscle activation characteristics of the vastus lateralis muscle of front leg from monophasic to biphasic to delay reaching peak muscle activation and thus prolong impact time. Therefore, the present findings suggests that the extent of timing errors in response to decreased velocity is influenced by the ability to correct muscle activation after its initiation rather than by delaying the initiation timing of muscle activation during baseball swings. PMID:25918848

  12. SU-E-T-755: Timing Characteristics of Proton and Carbon Ion Treatments Using a Synchrotron and Modulated Scanning

    SciTech Connect

    Zhao, J; Li, Y; Huang, Z; Deng, Y; Sun, L; Moyers, M; Hsi, W; Wu, X

    2015-06-15

    Purpose: The time required to deliver a treatment impacts not only the number of patients that can be treated each day but also the accuracy of delivery due to potential movements of patient tissues. Both macroscopic and microscopic timing characteristics of a beam delivery system were studied to examine their impacts on patient treatments. Methods: 35 patients were treated during a clinical trial to demonstrate safety and efficacy of a Siemens Iontris system prior to receiving approval from the Chinese Food and Drug Administration. The system has a variable cycle time and can provide proton beams from 48 to 221 MeV/n and carbon ions from 86 to 430 MeV/n. A modulated scanning beam delivery technique is used where the beam remains stationary at each spot aiming location and is not turned off while the spot quickly moves from one aiming location to the next. The treatment log files for 28 of the trial patients were analyzed to determine several timing characteristics. Results: The average portal time per target dose was 172.5 s/Gy for protons and 150.7 s/Gy for carbon ions. The maximum delivery time for any portal was less than 300 s. The average dwell time per spot was 12 ms for protons and 3.0 ms for carbon ions. The number of aiming positions per energy layer varied from 1 to 258 for protons and 1 to 621 for carbon ions. The average spill time and cycle time per energy layer were 1.20 and 2.68 s for protons and 0.95 and 4.73 s for carbon ions respectively. For 3 of the patients, the beam was gated on and off to reduce the effects of respiration. Conclusion: For a typical target volume of 153 cc as used in this clinical trial, the portal delivery times were acceptable.

  13. Leisure Time of Young Due to Some Socio-Demographic Characteristics

    ERIC Educational Resources Information Center

    Ðuranovic, Marina; Opic, Siniša

    2014-01-01

    The aim of this paper is to explore the prevalence of activities in leisure time of the young. A survey was conducted on 1062 students in 8 primary (n=505; 47,6%) and high schools (n=557; 52,4%) in Sisak - Moslavina County in the Republic of Croatia. The questionnaire of spending leisure time used was made up of 30 variables on a five-degree scale…

  14. Relationship between Emergency Restoration Time of Power Distribution Line after a Disaster and Geographical Characteristics of its Area

    NASA Astrophysics Data System (ADS)

    Sagai, Shigeo; Terano, Takao

    The effect of an outage caused by a disaster is serious to the society, because the power distribution line is a common basic infrastructure for life support. And the time estimation of emergency restoration process of power distribution line after a disaster is an emerging problem for the safety and security of the society. But the time estimation is a difficult problem and the only practical method in use is a simple approximation method, which doesn't take account of geographical characteristics of the objective area. So, we developed a method which can take account of the influences caused by the geographical characteristics of the objective area on the estimation of the emergency restoration. In this article, we describe an experimental analysis by the method.

  15. Hydrological connectivity of hillslopes and streams: Characteristic time scales and nonlinearities

    NASA Astrophysics Data System (ADS)

    McGuire, Kevin J.; McDonnell, Jeffrey J.

    2010-10-01

    Subsurface flow from hillslopes is widely recognized as an important contributor to streamflow generation; however, processes that control how and when hillslopes connect to streams remain unclear. We investigated stream and hillslope runoff dynamics through a wet-up period in watershed 10 of the H. J. Andrews Experimental Forest in the western Cascades of Oregon where the riparian zone has been removed by debris flows. We examined the controls on hillslope-stream connectivity on the basis of observations of hydrometric, stable isotope, and applied tracer responses and computed transit times for multiple runoff components for a series of storms during the wet-up phase of the 2002-2003 winter rainy season. Hillslope discharge was distinctly threshold-like with a near linear response and average quick flow ratio of 0.58 when antecedent rainfall was greater than 20 mm. Hillslope and stream stormflow varied temporally and showed strong hysteretic relationships. Event water mean transit times (8-34 h) and rapid breakthrough from applied hillslope tracer additions demonstrated that subsurface contributing areas extend far upslope during events. Despite rapid hillslope transport processes during events, soil water and runoff mean transit times during nonstorm conditions were greater than the time scale of storm events. Soil water mean transit times ranged between 10 and 25 days. Hillslope seepage and catchment base flow mean transit times were between 1 and 2 years. We describe a conceptual model that captures variable physical flow pathways, their synchronicity, threshold activation, hysteresis, and transit times through changing antecedent wetness conditions that illustrate the different stages of hillslope and stream connectivity.

  16. Heart rate time series characteristics for early detection of infections in critically ill patients.

    PubMed

    Tambuyzer, T; Guiza, F; Boonen, E; Meersseman, P; Vervenne, H; Hansen, T K; Bjerre, M; Van den Berghe, G; Berckmans, D; Aerts, J M; Meyfroidt, G

    2017-04-01

    It is difficult to make a distinction between inflammation and infection. Therefore, new strategies are required to allow accurate detection of infection. Here, we hypothesize that we can distinguish infected from non-infected ICU patients based on dynamic features of serum cytokine concentrations and heart rate time series. Serum cytokine profiles and heart rate time series of 39 patients were available for this study. The serum concentration of ten cytokines were measured using blood sampled every 10 min between 2100 and 0600 hours. Heart rate was recorded every minute. Ten metrics were used to extract features from these time series to obtain an accurate classification of infected patients. The predictive power of the metrics derived from the heart rate time series was investigated using decision tree analysis. Finally, logistic regression methods were used to examine whether classification performance improved with inclusion of features derived from the cytokine time series. The AUC of a decision tree based on two heart rate features was 0.88. The model had good calibration with 0.09 Hosmer-Lemeshow p value. There was no significant additional value of adding static cytokine levels or cytokine time series information to the generated decision tree model. The results suggest that heart rate is a better marker for infection than information captured by cytokine time series when the exact stage of infection is not known. The predictive value of (expensive) biomarkers should always be weighed against the routinely monitored data, and such biomarkers have to demonstrate added value.

  17. Time-domain diffuse optical tomography using analytic statistical characteristics of photon trajectories

    SciTech Connect

    Konovalov, Aleksandr B; Vlasov, V V; Kalintsev, A G; Lyubimov, Vladimir V; Kravtsenyuk, Olga V

    2006-11-30

    The inverse problem of diffuse optical tomography (DOT) is reduced by the method of photon average trajectories (PAT) to the solution of the integral equation integrated along the conditional mean statistical photon trajectory. The PAT bending near the flat boundary of a scattering medium is estimated analytically. These estimates are used to determine the analytic statistical characteristics of photon trajectories for the flat layer geometry. The inverse DOT problem is solved by using the multiplicative algebraic algorithm modified to improve the convergence of the iteration reconstruction process. The numerical experiment shows that the modified PAT method permits the reconstruction of near-surface optical inhomogeneities virtually without distortions. (special issue devoted to multiple radiation scattering in random media)

  18. Correlation of Biological Characteristics of Smolts with Survival and Travel Time, 1987 Technical Report.

    SciTech Connect

    Rondorf, Dennis W.; Beeman, John W.; Free, Mary E.

    1988-06-01

    The biological characteristics of smolts were examined to determine their effect on estimates of survival in the Columbia and Snake rivers. Freeze branded groups of steelhead trout (Salmo gairdneri) from Lyons Ferry State Fish Hatchery (SFH) and Wells SFH and spring chinook salmon (Oncorhynchus tshawytscha) from Winthrop National Fish Hatchery (NFH) were used to estimate survival. Past estimates of survival, using a ratio of test and control fish recaptured at McNary Dam, have resulted in estimates > 100%, presumably due to some unknown bias. Study objectives were to determine if stress and descaling, degree of smoltification, and prevalence of bacterial kidney disease (BKD) differed among test and control groups of fish, thereby biasing survival estimates. 19 refs., 20 figs., 10 tabs.

  19. Time course and characteristics of symptom distress and quality of life at the end of life.

    PubMed

    Kutner, Jean S; Bryant, Lucinda L; Beaty, Brenda L; Fairclough, Diane L

    2007-09-01

    This study sought to describe the characteristics and correlates of symptom distress and quality of life (QOL) among persons receiving hospice/palliative care. English-speaking adults (n=86), their nurses (n=86), and family caregivers (n=49) from 11 hospice/palliative care organizations completed the Memorial Symptom Assessment Scale (MSAS) and McGill Quality of Life Questionnaire (MQOL) at hospice/palliative care enrollment, at one week, two weeks, then monthly until death or discharge. Mixed effects modeling using proxy reports to impute missing patient-reported data were used to describe predictors of symptom distress and QOL. Given study population attrition due to death, analyses are limited to the first 17 days following hospice/palliative care admission. While lack of energy and pain were the most prevalent and distressing symptoms (prevalence 92% and 82%, respectively; mean MSAS scores 3.27 and 2.71, respectively), pain was identified as the most distressing symptom based on its contribution to MSAS summary scores and responses to a single-item "most distressing symptom" question. Pain, nonpain symptom distress, and MQOL scores remained fairly stable throughout the study period. Distress from all other physical symptoms was significantly associated with distress due to pain. There were no significant associations between patient characteristics and distress due to pain. While greater psychological symptom distress had a negative association with QOL, neither pain nor other physical symptom distress was associated with QOL. The persistence of significant symptom distress, particularly due to pain, argues for the need for enhanced evidence to guide care provided in the last days and weeks of life.

  20. Characteristics of zinc sulphide nanostructures grown onsilica modified-polyaniline with polymerization time-dependent

    NASA Astrophysics Data System (ADS)

    Potestas, M.; Alguno, A.; Vequizo, R.; Sambo, B. R.; Odarve, M. K.

    2015-06-01

    Growth of zinc sulphide (ZnS) nanostructures on silica modified-polyaniline (SM- PAni) with polymerization time-dependent was prepared using chemical bath deposition (CBD) technique. The grown samples were characterized by scanning electron microscopy (SEM) equipped with energy dispersive x-ray spectroscopy (EDS) and fourier transform infrared spectroscopy (FTIR). SEM images revealed that polyaniline rod-like nanostructures and ZnS nanospheres were successfully grown. The average diameter of the grown ZnS nanospheres did not significantly change by changing the growth time of the polyaniline. However, ZnS nanospheres grown with longer polymerization time of PAni is less dense and loosely bound as compared to shorter polymerization time of PAni. The less density of ZnS nanostructures with longer polymerization time of PAni may be due to the presence of PAni agglomerates that hinders the growth of ZnS nanospheres. Furthermore, FTIR spectra confirmed that the grown polyaniline is of emeraldine salt oxidation state which is the most conductive state of PAni.

  1. Study of Electromagnetic Repulsion Switch to High Speed Reclosing and Recover Time Characteristics of Superconductor

    NASA Astrophysics Data System (ADS)

    Koyama, Tomonori; Kaiho, Katsuyuki; Yamaguchi, Iwao; Yanabu, Satoru

    Using a high-temperature superconductor, we constructed and tested a model superconducting fault current limiter (SFCL). The superconductor and vacuum interrupter as the commutation switch were connected in parallel using a bypass coil. When the fault current flows in this equipment, the superconductor is quenched and the current is then transferred to the parallel coil due to the voltage drop in the superconductor. This large current in the parallel coil actuates the magnetic repulsion mechanism of the vacuum interrupter and the current in the superconductor is broken. Using this equipment, the current flow time in the superconductor can be easily minimized. On the other hand, the fault current is also easily limited by large reactance of the parallel coil. This system has many merits. So, we introduced to electromagnetic repulsion switch. There is duty of high speed re-closing after interrupting fault current in the electrical power system. So the SFCL should be recovered to superconducting state before high speed re-closing. But, superconductor generated heat at the time of quench. It takes time to recover superconducting state. Therefore it is a matter of recovery time. In this paper, we studied recovery time of superconductor. Also, we proposed electromagnetic repulsion switch with reclosing system.

  2. Review of Thawing Time Prediction Models Depending
on Process Conditions and Product Characteristics

    PubMed Central

    Kluza, Franciszek; Spiess, Walter E. L.; Kozłowicz, Katarzyna

    2016-01-01

    Summary Determining thawing times of frozen foods is a challenging problem as the thermophysical properties of the product change during thawing. A number of calculation models and solutions have been developed. The proposed solutions range from relatively simple analytical equations based on a number of assumptions to a group of empirical approaches that sometimes require complex calculations. In this paper analytical, empirical and graphical models are presented and critically reviewed. The conditions of solution, limitations and possible applications of the models are discussed. The graphical and semi--graphical models are derived from numerical methods. Using the numerical methods is not always possible as running calculations takes time, whereas the specialized software and equipment are not always cheap. For these reasons, the application of analytical-empirical models is more useful for engineering. It is demonstrated that there is no simple, accurate and feasible analytical method for thawing time prediction. Consequently, simplified methods are needed for thawing time estimation of agricultural and food products. The review reveals the need for further improvement of the existing solutions or development of new ones that will enable accurate determination of thawing time within a wide range of practical conditions of heat transfer during processing. PMID:27904387

  3. Characteristics and control response of the TOPAZ II Reactor System Real-time Dynamic Simulator

    SciTech Connect

    Kwok, K.S.

    1993-11-12

    A dynamic simulator of the TOPAZ II reactor system has been developed for the Nuclear Electric Propulsion Space Test Program. The simulator combines first-principle modeling and empirical correlations in its algorithm to attain the modeling accuracy and computational through-put that are required for real-time execution. The overall execution time of the simulator for each time step is 15 ms when no data is written to the disk, and 18 ms when nine double precision data points are written to the disk once in every time step. The simulation program has been tested and it is able to handle a step decrease of $8 worth of reactivity. It also provides simulations of fuel, emitter, collector, stainless steel, and ZrH moderator failures. Presented in this paper are the models used in the calculations, a sample simulation session, and a discussion of the performance and limitations of the simulator. The simulator has been found to provide realistic real-time dynamic response of the TOPAZ II reactor system under both normal and casualty conditions.

  4. Review of Thawing Time Prediction Models Depending
on Process Conditions and Product Characteristics.

    PubMed

    Góral, Dariusz; Kluza, Franciszek; Spiess, Walter E L; Kozłowicz, Katarzyna

    2016-03-01

    Determining thawing times of frozen foods is a challenging problem as the thermophysical properties of the product change during thawing. A number of calculation models and solutions have been developed. The proposed solutions range from relatively simple analytical equations based on a number of assumptions to a group of empirical approaches that sometimes require complex calculations. In this paper analytical, empirical and graphical models are presented and critically reviewed. The conditions of solution, limitations and possible applications of the models are discussed. The graphical and semi--graphical models are derived from numerical methods. Using the numerical methods is not always possible as running calculations takes time, whereas the specialized software and equipment are not always cheap. For these reasons, the application of analytical-empirical models is more useful for engineering. It is demonstrated that there is no simple, accurate and feasible analytical method for thawing time prediction. Consequently, simplified methods are needed for thawing time estimation of agricultural and food products. The review reveals the need for further improvement of the existing solutions or development of new ones that will enable accurate determination of thawing time within a wide range of practical conditions of heat transfer during processing.

  5. Characteristics of DUI recidivists: a 12-year follow-up study of first time DUI offenders.

    PubMed

    Cavaiola, Alan A; Strohmetz, David B; Abreo, Sandra D

    2007-04-01

    77 individuals convicted of a drinking and driving (DUI) offense were screened for recidivism approximately 12 years following their first offense. At the time of the initial DUI conviction, participants were administered the MAST and the MMPI-2. Participants' drinking history and driving history and arrest at the time of screening and at a 12-year follow-up were also reviewed. The results indicate that, among DUI recidivists, on average 6 years elapsed between their first and second DUI offenses. Driving history prior to the first DUI offense was predictive of later recidivism. The only significant finding from the MAST and MMPI results was that repeat offenders tended to have higher scores on the L and K validity scales of the MMPI. These results are discussed in the context of Jessor's Problem-Behavior Theory and as well their clinical implications for screening and treatment decisions involving first time DUI offenders.

  6. Taekwondo techniques and competition characteristics involved in time-loss injuries.

    PubMed

    Beis, Konstantinos; Pieter, Willy; Abatzides, George

    2007-01-01

    The purpose of this study was to assess time-loss injuries in young and adult taekwondo athletes. Participants were 2739 children (11-13 years), Junior (14-17 years) and adult males and females (18 years and older) competing in the national Greek championships. Injury data were collected by project staff with all diagnoses made by the tournament physician. Odds ratios were computed as well as 95% confidence intervals around the injury rates. The female Juniors had a higher time-loss injury rate (Fisher's Exact Test p = 0.033) than their adult counterparts. However, they were not at a higher risk of incurring a time-loss injury: OR = 0.143, 95% CI: 0.018-1.124. Collapsed over age, the females as a group recorded more time-loss injuries [11.36/1,000 A-E (95% CI: 6.25-16.47) versus 7.40/1,000 A-E (95% CI: 4.44-10.36)], but this was not significant (OR = 0.703, 95% CI: 0.383-1.293). In the Juniors, the boys only incurred time-loss injuries to the head and neck. There was no difference in the Junior girls in the distribution of time-loss injuries across body region, although they were at higher risk of sustaining an injury to the head and neck (OR = 1.510, 95% CI: 0.422-5.402) but this was not statistically significant. Although there were no statistical differences among age groups within gender, the Junior boys and girls (11-13 years) sustained more cerebral concussions. The Junior boys were at a higher risk of incurring a cerebral concussion than the boys (OR = 7.871, 95% CI: 0.917-67.583, Fisher's Exact Test p = 0.036). In the males, there was no difference between the men and Junior boys in injury rate for swing kicks compared to other techniques (OR = 2.000, 95% CI = 0.397-28.416). There also was no difference between the men and boys (OR = 4.800, 95% CI: 0.141-58.013). To help reduce the incidence of time-loss injuries in taekwondo, especially cerebral concussions, it is suggested for coaches to emphasize blocking skills. Educating referees, coaches and athletes

  7. Taekwondo Techniques and Competition Characteristics Involved in Time-Loss Injuries

    PubMed Central

    Beis, Konstantinos; Pieter, Willy; Abatzides, George

    2007-01-01

    The purpose of this study was to assess time-loss injuries in young and adult taekwondo athletes. Participants were 2739 children (11-13 years), Junior (14-17 years) and adult males and females (18 years and older) competing in the national Greek championships. Injury data were collected by project staff with all diagnoses made by the tournament physician. Odds ratios were computed as well as 95% confidence intervals around the injury rates. The female Juniors had a higher time-loss injury rate (Fisher’s Exact Test p = 0.033) than their adult counterparts. However, they were not at a higher risk of incurring a time-loss injury: OR = 0.143, 95% CI: 0.018-1.124. Collapsed over age, the females as a group recorded more time-loss injuries [11.36/1,000 A-E (95% CI: 6.25-16.47) versus 7.40/1,000 A-E (95% CI: 4.44-10.36)], but this was not significant (OR = 0.703, 95% CI: 0.383-1.293). In the Juniors, the boys only incurred time-loss injuries to the head and neck. There was no difference in the Junior girls in the distribution of time-loss injuries across body region, although they were at higher risk of sustaining an injury to the head and neck (OR = 1.510, 95% CI: 0.422-5.402) but this was not statistically significant. Although there were no statistical differences among age groups within gender, the Junior boys and girls (11-13 years) sustained more cerebral concussions. The Junior boys were at a higher risk of incurring a cerebral concussion than the boys (OR = 7.871, 95% CI: 0.917-67.583, Fisher’s Exact Test p = 0.036). In the males, there was no difference between the men and Junior boys in injury rate for swing kicks compared to other techniques (OR = 2.000, 95% CI = 0.397-28.416). There also was no difference between the men and boys (OR = 4.800, 95% CI: 0.141-58.013). To help reduce the incidence of time-loss injuries in taekwondo, especially cerebral concussions, it is suggested for coaches to emphasize blocking skills. Educating referees, coaches and

  8. Effect of reaction time on the characteristics of catalytically grown boron nitride nanotubes

    SciTech Connect

    Mohamed, Norani Muti E-mail: pervaiz-pas@yahoo.com E-mail: zainabh@petronas.com.my; Ahmad, Pervaiz E-mail: pervaiz-pas@yahoo.com E-mail: zainabh@petronas.com.my; Saheed, Mohamed Shuaib Mohamed E-mail: pervaiz-pas@yahoo.com E-mail: zainabh@petronas.com.my; Burhanudin, Zainal Arif E-mail: pervaiz-pas@yahoo.com E-mail: zainabh@petronas.com.my

    2014-10-24

    The paper reports on the growth of boron nitride nanotube (BNNTs) on Si substrate by catalytic chemical vapor deposition technique and the effect of reaction time and temperature on the size and purity were investigated. Scanning electron microscopy image revealed the bamboo-like BNNTs of multiwalled type with interlayer spacing of 0.34 nm. EDX analysis described the presence of a small percentage of Mg in the sample, indicating the combination of base-tip growth model for the sample synthesized at 1200°C. The reaction time has an effect of extending the length of the BNNTs until the catalyst is oxidized or covered by growth precursor.

  9. Effect of reaction time on the characteristics of catalytically grown boron nitride nanotubes

    NASA Astrophysics Data System (ADS)

    Mohamed, Norani Muti; Ahmad, Pervaiz; Saheed, Mohamed Shuaib Mohamed; Burhanudin, Zainal Arif

    2014-10-01

    The paper reports on the growth of boron nitride nanotube (BNNTs) on Si substrate by catalytic chemical vapor deposition technique and the effect of reaction time and temperature on the size and purity were investigated. Scanning electron microscopy image revealed the bamboo-like BNNTs of multiwalled type with interlayer spacing of 0.34 nm. EDX analysis described the presence of a small percentage of Mg in the sample, indicating the combination of base-tip growth model for the sample synthesized at 1200°C. The reaction time has an effect of extending the length of the BNNTs until the catalyst is oxidized or covered by growth precursor.

  10. Characteristic recovery times of Forbush-type decreases in the cosmic radiation. I - Observations at earth at different energies

    NASA Technical Reports Server (NTRS)

    Lockwood, J. A.; Webber, W. R.; Jokipii, J. R.

    1986-01-01

    Data on 30 asymmetric Forbush decreases recorded by the IMP spacecraft at 1 AU and the Mt. Washington neutron monitor over the period 1972-84 are examined to characterize the recovery characteristics of cosmic rays after the events. The spacecraft data are concentrated at energies of 1.7 GV, while the terrestrial instruments recorded events at 5 GV. Attention is paid to the relative amplitudes of the recorded transient decreases, the characteristic recovery times, and the energy dependence of the amplitudes and recovery time. The recovery times were found to be equal at both energy levels, supporting a concept of energy independence for the recoveries. Also, no correlations were found between the recovery times and the occurrences of a solar magnetic field reversal or with phase in the solar modulation cycle. A time-dependent, two-dimensional model is defined, which expresses the cosmic ray particle distributions as a function of the decay of the disturbance, with a small dependence on the transport parameters of the cosmic rays.

  11. The impact of fragility fractures on work and characteristics associated with time to return to work.

    PubMed

    Rotondi, N K; Beaton, D E; Ilieff, M; Adhihetty, C; Linton, D; Bogoch, E; Sale, J; Hogg-Johnson, S; Jaglal, S; Jain, R; Weldon, J

    2017-01-01

    We examined the impact of fragility fractures on the work outcomes of employed patients. The majority successfully returned to their previous jobs in a short amount of time, and productivity loss at work was low. Our findings underscore the fast recovery rates of working fragility fracture patients.

  12. Temporal Characteristics of the Predictive Synchronous Firing Modeled by Spike-Timing-Dependent Plasticity

    ERIC Educational Resources Information Center

    Kitano, Katsunori; Fukai, Tomoki

    2004-01-01

    When a sensory cue was repeatedly followed by a behavioral event with fixed delays, pairs of premotor and primary motor neurons showed significant increases of coincident spikes at times a monkey was expecting the event. These results provided evidence that neuronal firing synchrony has predictive power. To elucidate the underlying mechanism, here…

  13. An Investigation of the Erosion in New Major Innovation Characteristics over Time

    ERIC Educational Resources Information Center

    O'Donnell, Joseph B.; Sauer, Paul L.

    2009-01-01

    A recent study by O'Donnell and Sauer (2008) indicated, that over time, the benefit of launching new majors to reduce freshman attrition dissipated. In 2004, new majors had a significant effect on reducing attrition. By 2007, however, these same new majors were no longer significant predictors of attrition. What happened between 2004 and 2007 to…

  14. Characteristics of Disfluency Clusters over Time in Preschool Children Who Stutter

    ERIC Educational Resources Information Center

    Sawyer, Jean; Yairi, Ehud

    2010-01-01

    Purpose: Disfluency clusters in preschool children were analyzed to determine whether they occurred at rates above chance, whether they changed over time, and whether they could differentiate children who would later persist in, or recover from, stuttering. Method: Thirty-two children recruited near stuttering onset were grouped on the basis of…

  15. A characteristic space-time conservation element and solution element method for conservation laws

    NASA Astrophysics Data System (ADS)

    Shen, Hua; Wen, Chih-Yung; Zhang, De-Liang

    2015-05-01

    In this paper, an upwind space-time conservation element and solution element (CE/SE) method is developed to solve conservation laws. In the present method, the mesh quantity and spatial derivatives are the independent marching variables, which is consistent with the original CE/SE method proposed by Chang (1995) [5]. The staggered time marching strategy and the definition of conservation element (CE) also follow Chang's propositions. Nevertheless, the definition of solution element (SE) is modified from that of Chang. The numerical flux through the interface of two different conservation elements is not directly derived by a Taylor expansion in the reversed time direction as proposed by Chang, but determined by an upwind procedure. This modification does not change the local and global conservative features of the original method. Although, the time marching scheme of mesh variables is the same with the original method, the upwind fluxes are involved in the calculation of spatial derivatives, yielding a totally different approach from that of Chang's method. The upwind procedure breaks the space-time inversion invariance of the original scheme, so that the new scheme can be directly applied to capture discontinuities without spurious oscillations. In addition, the present method maintains low dissipation in a wide range of CFL number (from 10-6 to 1). Furthermore, we extend the upwind CE/SE method to solve the Euler equations by adopting three different approximate Riemann solvers including Harten, Lax and van Leer (HLL) Riemann solver, contact discontinuity restoring HLLC Riemann solver and mathematically rigorous Roe Riemann solver. Extensive numerical examples are carried out to demonstrate the robustness of the present method. The numerical results show that the new CE/SE solvers perform improved resolutions.

  16. Statistical characteristics of storm interevent time, depth, and duration for eastern New Mexico, Oklahoma, and Texas

    USGS Publications Warehouse

    Asquith, William H.; Roussel, Meghan C.; Cleveland, Theodore G.; Fang, Xing; Thompson, David B.

    2006-01-01

    The design of small runoff-control structures, from simple floodwater-detention basins to sophisticated best-management practices, requires the statistical characterization of rainfall as a basis for cost-effective, risk-mitigated, hydrologic engineering design. The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, has developed a framework to estimate storm statistics including storm interevent times, distributions of storm depths, and distributions of storm durations for eastern New Mexico, Oklahoma, and Texas. The analysis is based on hourly rainfall recorded by the National Weather Service. The database contains more than 155 million hourly values from 774 stations in the study area. Seven sets of maps depicting ranges of mean storm interevent time, mean storm depth, and mean storm duration, by county, as well as tables listing each of those statistics, by county, were developed. The mean storm interevent time is used in probabilistic models to assess the frequency distribution of storms. The Poisson distribution is suggested to model the distribution of storm occurrence, and the exponential distribution is suggested to model the distribution of storm interevent times. The four-parameter kappa distribution is judged as an appropriate distribution for modeling the distribution of both storm depth and storm duration. Preference for the kappa distribution is based on interpretation of L-moment diagrams. Parameter estimates for the kappa distributions are provided. Separate dimensionless frequency curves for storm depth and duration are defined for eastern New Mexico, Oklahoma, and Texas. Dimension is restored by multiplying curve ordinates by the mean storm depth or mean storm duration to produce quantile functions of storm depth and duration. Minimum interevent time and location have slight influence on the scale and shape of the dimensionless frequency curves. Ten example problems and solutions to possible applications are

  17. Effect of extraction time and temperature on the characteristics of loosely bound pectins from Japanese plum.

    PubMed

    Basanta, María F; Ponce, Nora M A; Rojas, Ana M; Stortz, Carlos A

    2012-06-05

    The cell wall composition of Japanese plums (Prunus salicina) at six developmental stages was previously evaluated (Ponce et al., J. Agric. Food Chem. 2010, 58, 2562-2570). This fruit is an interesting source of pectins, polysaccharides of valuable functionality for pharmaceutical and food formulations. In the present work it was investigated how the different conditions for the aqueous extraction of pectins from Japanese plums affect the yield as well as their chemical and rheological characteristics. It has been determined that extraction with water at room temperature for periods longer than 2h did not produce additional increment of yield (12%) but decreased the average molecular weights of the extracted pectins. Pectins with a degree of methylation ≈40% with high viscosity in water and with adequate molecular weights (≈72,000) were obtained. Conversely, utilization of boiling water for extraction increased considerably the yields (33-38%) but the extracted pectins showed significant lower viscosity in water in spite of their higher molecular weights. The poorer thickening ability was associated to the lower proportion of arabinose residues present in the hairy regions of the pectin macromolecules extracted by hot water, which led the polymers to interact more transiently in a 2% w/v water solution.

  18. Vocal characteristics of pygmy blue whales and their change over time.

    PubMed

    Gavrilov, Alexander N; McCauley, Robert D; Salgado-Kent, Chandra; Tripovich, Joy; Burton, Chris

    2011-12-01

    Vocal characteristics of pygmy blue whales of the eastern Indian Ocean population were analyzed using data from a hydroacoustic station deployed off Cape Leeuwin in Western Australia as part of the Comprehensive Nuclear-Test-Ban Treaty monitoring network, from two acoustic observatories of the Australian Integrated Marine Observing System, and from individual sea noise loggers deployed in the Perth Canyon. These data have been collected from 2002 to 2010, inclusively. It is shown that the themes of pygmy blue whale songs consist of ether three or two repeating tonal sounds with harmonics. The most intense sound of the tonal theme was estimated to correspond to a source level of 179 ± 2 dB re 1 μPa at 1 m measured for 120 calls from seven different animals. Short-duration calls of impulsive downswept sound from pygmy blue whales were weaker with the source level estimated to vary between 168 to 176 dB. A gradual decrease in the call frequency with a mean rate estimated to be 0.35 ± 0.3 Hz/year was observed over nine years in the frequency of the third harmonic of tonal sound 2 in the whale song theme, which corresponds to a negative trend of about 0.12 Hz/year in the call fundamental frequency.

  19. [Real-time UV imaging of chloramphenicol intrinsic dissolution characteristics from ophthalmic in situ gel].

    PubMed

    Chen, Jian-Xiu; Guo, Zhen; Li, Hai-Yan; Wu, Li; He, Zhong-Gui; Hu, Rong-Feng; Zhang, Ji-Wen

    2013-07-01

    In this paper, chloramphenicol was selected as a model drug to prepare in situ gels. The intrinsic dissolution rate of chloramphenicol from in situ gel was evaluated using the surface dissolution imaging system. The results indicated that intrinsic dissolution rate of chloramphenicol thermosensitive in situ gel decreased significantly when the poloxamer concentration increased. The addition of the thickener reduced the intrinsic dissolution rate of chloramphenicol thermosensitive gel, wherein carbomer had the most impact. Different dilution ratios of simulated tear fluid greatly affected gel temperature, and had little influence on the intrinsic dissolution rate of chloramphenicol from the thermosensitive in situ gel. The pH of simulated tear fluid had little influence on the intrinsic dissolution rate of chloramphenicol thermosensitive in situ gel. For the pH sensitive in situ gel, the dissolution rates of chloramphenicol in weak acidic and neutral simulated tear fluids were slower than that in weak alkaline simulated tear fluid. In conclusion, the intrinsic dissolution of chloramphenicol from in situ gel was dependent on formulation and physiological factors. With advantages of small volume sample required and rapid detection, the UV imaging method can be an efficient tool for the evaluation of drug release characteristics of ophthalmic in situ gel.

  20. Deformation characteristics and time-dependent notch sensitivity of Udimet 700 at intermediate temperatures

    NASA Technical Reports Server (NTRS)

    Wilson, D. J.

    1974-01-01

    Time dependent notch sensitivity was observed in Udimet 700 sheet, bar, and investment castings between 1000 and 1400 F (538 -760 C), but not at 1600 F (871 C). As was the case for modified Waspaloy, Waspaloy and Inconel 718, it occurred in notched specimens loaded below the yield strength when the creep deformation was localized. For each alloy and notched specimen geometry, a stress-average particle size zone can be defined that characterizes the notch sensitive behavior.

  1. Spectral characteristics of steady quiet-time EMIC waves observed at geosynchronous orbit

    NASA Astrophysics Data System (ADS)

    Kim, Khan-Hyuk; Park, Jong-Sun; Omura, Yoshiharu; Shiokawa, Kazuo; Lee, Dong-Hun; Kim, Gi-Jeong; Jin, Ho; Lee, Ensang; Kwon, Hyuck-Jin

    2016-09-01

    We have studied the spectral properties of quiet-time electromagnetic ion cyclotron (EMIC) waves following a steady quiet condition, which is defined with Kp values ≤1 during 12 h, using GOES 10, 11, and 12 magnetometer data for solar minimum years 2007-2008. We identified 6584 steady quiet-time EMIC wave samples using a semiautomated procedure. Approximately 82% of the samples were observed in the morning-to-early afternoon sector (0700-1500 magnetic local time) with a maximum occurrence near noon, and their peak frequencies were mostly in the He band. We found that the occurrence rate of steady quiet-time EMIC waves is higher than that of EMIC waves for all or quiet geomagnetic conditions (Dst > 0 nT or AE < 100 nT) reported in previous studies by a factor of 2 or more. The frequency ratio fpeak (sample's peak frequency)/fH+ (the local proton gyrofrequency) of the He-band waves (˜0.11-0.16) under steady quiet conditions is lower than that (˜0.14-0.24) in previous studies. These results may be due to the fact that the plasmasphere expanded more frequently to the geosynchronous region under extremely quiet geomagnetic conditions in 2007-2008 than the periods selected in previous studies. The amplitude and frequency of He-band EMIC waves for nonlinear wave growth are examined as changing cold plasma density at geosynchronous orbit. We confirm that the spectral properties of observed EMIC waves are in good agreement with the nonlinear theory.

  2. Extracting Concrete Thermal Characteristics from Temperature Time History of RC Column Exposed to Standard Fire

    PubMed Central

    2014-01-01

    A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC) columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The thermal conductivity of concrete was then determined by optimizing the numerical solution of the model to meet the observed time history of temperature variations. The determined thermal conductivity with respect to temperature was then verified against standard thermal conductivity measurements of concrete bricks. It is concluded that the proposed method can be used to conservatively estimate thermal conductivity of concrete for design purpose. Finally, the thermal radiation properties of concrete for the RC column were estimated from the thermal equilibrium at the surface of the column. The radiant heat transfer ratio of concrete representing absorptivity to emissivity ratio of concrete during fire was evaluated and is suggested as a concrete criterion that can be used in fire safety assessment. PMID:25180197

  3. Time- and spectrally resolved characteristics of flavin fluorescence in U87MG cancer cells in culture

    NASA Astrophysics Data System (ADS)

    Horilova, Julia; Cunderlikova, Beata; Marcek Chorvatova, Alzbeta

    2015-05-01

    Early detection of cancer is crucial for the successful diagnostics of its presence and its subsequent treatment. To improve cancer detection, we tested the progressive multimodal optical imaging of U87MG cells in culture. A combination of steady-state spectroscopic methods with the time-resolved approach provides a new insight into the native metabolism when focused on endogenous tissue fluorescence. In this contribution, we evaluated the metabolic state of living U87MG cancer cells in culture by means of endogenous flavin fluorescence. Confocal microscopy and time-resolved fluorescence imaging were employed to gather spectrally and time-resolved images of the flavin fluorescence. We observed that flavin fluorescence in U87MG cells was predominantly localized outside the cell nucleus in mitochondria, while exhibiting a spectral maximum under 500 nm and fluorescence lifetimes under 1.4 ns, suggesting the presence of bound flavins. In some cells, flavin fluorescence was also detected inside the cell nuclei in the nucleoli, exhibiting longer fluorescence lifetimes and a red-shifted spectral maximum, pointing to the presence of free flavin. Extra-nuclear flavin fluorescence was diminished by 2-deoxyglucose, but failed to increase with 2,4-dinitrophenol, the uncoupler of oxidative phosphorylation, indicating that the cells use glycolysis, rather than oxidative phosphorylation for functioning. These gathered data are the first step toward monitoring the metabolic state of U87MG cancer cells.

  4. Characteristics of the near-Earth magnetotail variations at the time of substorm onset

    NASA Astrophysics Data System (ADS)

    Machida, S.; Miyashita, Y.; Ieda, A.; Saito, Y.

    2013-12-01

    From the result of our statistical analysis with GEOTAIL and THEMIS data, we confirmed that tailward plasma flows are created in association with the plasma flows that propagate from X ~ -12 Re toward the earth at the time of substorm onset. To understand the physical mechanism of the formation of such tailward flows, we have performed a case study of substorm event occurred at 10:46 UT on June 22, 1997 when the GEOTAIL was located at (X, Y) ~ (-9, 6) Re and encountered with the flow bursts. The event started with earthward flows for about 2 min with the northward magnetic field enhancement, followed by slow tailward flows. Such an earthward and tailward flow sequence repeated three times. By calculating the electric current from electron and ion moment data, we found the variation in the X-component of JxB force that can be interpreted to have close relationship with the enhancement of earthward flows. Namely, the flows are not simply generated at a distant location and reach the GEOTAIL, but they are still under acceleration at X ~ -10 Re. After the passage of the flow front, the (JxB)x term takes negative values. The time derivative of Vx does not necessarily correspond to (JxB)x/mn. This inconsistency might be due to the contribution of the terms such as -grad P or (Vgrad) V. It is also necessary to check the possibility of the decoupling between electrons and ions as well as the effect of anomalous resistivity.

  5. Extracting concrete thermal characteristics from temperature time history of RC column exposed to standard fire.

    PubMed

    Kim, Jung J; Youm, Kwang-Soo; Reda Taha, Mahmoud M

    2014-01-01

    A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC) columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The thermal conductivity of concrete was then determined by optimizing the numerical solution of the model to meet the observed time history of temperature variations. The determined thermal conductivity with respect to temperature was then verified against standard thermal conductivity measurements of concrete bricks. It is concluded that the proposed method can be used to conservatively estimate thermal conductivity of concrete for design purpose. Finally, the thermal radiation properties of concrete for the RC column were estimated from the thermal equilibrium at the surface of the column. The radiant heat transfer ratio of concrete representing absorptivity to emissivity ratio of concrete during fire was evaluated and is suggested as a concrete criterion that can be used in fire safety assessment.

  6. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    PubMed

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

  7. A Comparison of Anthropometric and Training Characteristics between Female and Male Half-Marathoners and the Relationship to Race Time

    PubMed Central

    Friedrich, Miriam; Rüst, Christoph A.; Rosemann, Thomas; Knechtle, Patrizia; Barandun, Ursula; Lepers, Romuald; Knechtle, Beat

    2013-01-01

    Purpose Lower limb skin-fold thicknesses have been differentially associated with sex in elite runners. Front thigh and medial calf skin-fold appear to be related to 1,500m and 10,000m time in men but 400m time in women. The aim of the present study was to compare anthropometric and training characteristics in recreational female and male half-marathoners. Methods The association between both anthropometry and training characteristics and race time was investigated in 83 female and 147 male recreational half marathoners using bi- and multi-variate analyses. Results In men, body fat percentage (β=0.6), running speed during training (β=-3.7), and body mass index (β=1.9) were related to half-marathon race time after multi-variate analysis. After exclusion of body mass index, r2 decreased from 0.51 to 0.49, but body fat percentage (β=0.8) and running speed during training (β=-4.1) remained predictive. In women, body fat percentage (β=0.75) and speed during training (β=-6.5) were related to race time (r2=0.73). For women, the exclusion of body mass index had no consequence on the predictive variables for half-marathon race time. Conclusion To summarize, in both female and male recreational half-marathoners, both body fat percentage and running speed during training sessions were related to half-marathon race times when corrected with co-variates after multi-variate regression analyses. PMID:24868427

  8. Physicochemical and toxicological characteristics of welding fume derived particles generated from real time welding processes.

    PubMed

    Chang, Cali; Demokritou, Philip; Shafer, Martin; Christiani, David

    2013-01-01

    Welding fume particles have been well studied in the past; however, most studies have examined welding fumes generated from machine models rather than actual exposures. Furthermore, the link between physicochemical and toxicological properties of welding fume particles has not been well understood. This study aims to investigate the physicochemical properties of particles derived during real time welding processes generated during actual welding processes and to assess the particle size specific toxicological properties. A compact cascade impactor (Harvard CCI) was stationed within the welding booth to sample particles by size. Size fractionated particles were extracted and used for both off-line physicochemical analysis and in vitro cellular toxicological characterization. Each size fraction was analyzed for ions, elemental compositions, and mass concentration. Furthermore, real time optical particle monitors (DustTrak™, TSI Inc., Shoreview, Minn.) were used in the same welding booth to collect real time PM2.5 particle number concentration data. The sampled particles were extracted from the polyurethane foam (PUF) impaction substrates using a previously developed and validated protocol, and used in a cellular assay to assess oxidative stress. By mass, welding aerosols were found to be in coarse (PM 2.5–10), and fine (PM 0.1–2.5) size ranges. Most of the water soluble (WS) metals presented higher concentrations in the coarse size range with some exceptions such as sodium, which presented elevated concentration in the PM 0.1 size range. In vitro data showed size specific dependency, with the fine and ultrafine size ranges having the highest reactive oxygen species (ROS) activity. Additionally, this study suggests a possible correlation between welders' experience, the welding procedure and equipment used and particles generated from welding fumes. Mass concentrations and total metal and water soluble metal concentrations of welding fume particles may be

  9. Deformation characteristics and time-dependent notch sensitivity of Udimet 700 at intermediate temperatures

    NASA Technical Reports Server (NTRS)

    Wilson, D. J.

    1975-01-01

    Time-dependent notch sensitivity of Udimet 700 sheet, bar, and investment castings was observed between 1000 and 1400 F (538-760 C) but not at 1600 F (871 C). As was the case for Modified Waspaloy, Waspaloy, Rene 41, Inconel 718, and TD-NiCr, it occurred when notched specimens were loaded below the yield strength and when creep deformation was localized. For each gamma-prime strengthened alloy and notched specimen geometry, a stress-average particle size zone can be defined to characterize the notch-sensitive behavior.

  10. Characteristics of chiral and racemic ketoprofen drugs using terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Du, Yong; Liu, Jianjun; Hong, Zhi

    2013-08-01

    Absorption spectra of chiral S-(+)- and racemic RS-ketoprofen pharmaceutical molecules in crystalline form were recorded in the terahertz region between 6 and 66 cm-1 (0.2 ~ 2.0 THz) by using time-domain terahertz spectroscopic (THz-TDS) measurement. Different distinctive absorption features were observed which are strikingly sensitive to the change of subtle conformational structures within such isostructural crystal molecules. The results suggest that the THz-TDS technique can be definitely used for distinguishing between chiral and racemic compounds in pharmaceutical and biological fields.

  11. TEMPORAL COHERENCE AND FREQUENCY VS TIME CHARACTERISTICS OF A Q-SPOILED RUBY LASER,

    DTIC Science & Technology

    of change of the laser frequency during the Q-spoiled emission pulse is approximately twenty times the rate of change during a single spike of an...linear in the change in the number of excited states in the laser. Since the rate of change of population inversion during Q-spoiled emission is much...larger than for normal lasing it was expected, prior to this work, that a greater rate of change of frequency should be observed. This has now been confirmed. (Author)

  12. Tunnelling current-voltage characteristics of Angstrom gaps measured with terahertz time-domain spectroscopy

    PubMed Central

    Kim, Joon-Yeon; Kang, Bong Joo; Bahk, Young-Mi; Kim, Yong Seung; Park, Joohyun; Kim, Won Tae; Rhie, Jiyeah; Han, Sanghoon; Jeon, Hyeongtag; Park, Cheol-Hwan; Rotermund, Fabian; Kim, Dai-Sik

    2016-01-01

    Quantum tunnelling becomes inevitable as gap dimensions in metal structures approach the atomic length scale, and light passing through these gaps can be used to examine the quantum processes at optical frequencies. Here, we report on the measurement of the tunnelling current through a 3-Å-wide metal-graphene-metal gap using terahertz time-domain spectroscopy. By analysing the waveforms of the incident and transmitted terahertz pulses, we obtain the tunnelling resistivity and the time evolution of the induced current and electric fields in the gap and show that the ratio of the applied voltage to the tunnelling current is constant, i.e., the gap shows ohmic behaviour for the strength of the incident electric field up to 30 kV/cm. We further show that our method can be extended and applied to different types of nanogap tunnel junctions using suitable equivalent RLC circuits for the corresponding structures by taking an array of ring-shaped nanoslots as an example. PMID:27357346

  13. Investigating time-efficiency of forward masking paradigms for estimating basilar membrane input-output characteristics

    PubMed Central

    Fereczkowski, Michal; Jepsen, Morten L.; Dau, Torsten; MacDonald, Ewen N.

    2017-01-01

    It is well known that pure-tone audiometry does not sufficiently describe individual hearing loss (HL) and that additional measures beyond pure-tone sensitivity might improve the diagnostics of hearing deficits. Specifically, forward masking experiments to estimate basilar-membrane (BM) input-output (I/O) function have been proposed. However, such measures are very time consuming. The present study investigated possible modifications of the temporal masking curve (TMC) paradigm to improve time and measurement efficiency. In experiment 1, estimates of knee point (KP) and compression ratio (CR) of individual BM I/Os were derived without considering the corresponding individual “off-frequency” TMC. While accurate estimation of KPs was possible, it is difficult to ensure that the tested dynamic range is sufficient. Therefore, in experiment 2, a TMC-based paradigm, referred to as the “gap method”, was tested. In contrast to the standard TMC paradigm, the maker level was kept fixed and the “gap threshold” was obtained, such that the masker just masks a low-level (12 dB sensation level) signal. It is argued that this modification allows for better control of the tested stimulus level range, which appears to be the main drawback of the conventional TMC method. The results from the present study were consistent with the literature when estimating KP levels, but showed some limitations regarding the estimation of the CR values. Perspectives and limitations of both approaches are discussed. PMID:28355275

  14. Aerodynamics of cyclist posture, bicycle and helmet characteristics in time trial stage.

    PubMed

    Chabroux, Vincent; Barelle, Caroline; Favier, Daniel

    2012-07-01

    The present work is focused on the aerodynamic study of different parameters, including both the posture of a cyclist's upper limbs and the saddle position, in time trial (TT) stages. The aerodynamic influence of a TT helmet large visor is also quantified as a function of the helmet inclination. Experiments conducted in a wind tunnel on nine professional cyclists provided drag force and frontal area measurements to determine the drag force coefficient. Data statistical analysis clearly shows that the hands positioning on shifters and the elbows joined together are significantly reducing the cyclist drag force. Concerning the saddle position, the drag force is shown to be significantly increased (about 3%) when the saddle is raised. The usual helmet inclination appears to be the inclination value minimizing the drag force. Moreover, the addition of a large visor on the helmet is shown to provide a drag coefficient reduction as a function of the helmet inclination. Present results indicate that variations in the TT cyclist posture, the saddle position and the helmet visor can produce a significant gain in time (up to 2.2%) during stages.

  15. Breed, slaughter weight and ageing time effects on physico-chemical characteristics of lamb meat.

    PubMed

    Martínez-Cerezo, S; Sañudo, C; Panea, B; Medel, I; Delfa, R; Sierra, I; Beltrán, J A; Cepero, R; Olleta, J L

    2005-02-01

    The effects of breed, slaughter weight and ageing time on the meat quality of the three most important Spanish breeds were considered. Two hundred and twenty-five lambs of Rasa Aragonesa-local meat breed-, Churra-local dairy breed- and Spanish Merino were used. Animals (75 of each breed) were slaughtered at three different live weights (10-12, 20-22 or 30-32 kg), and the meat was aged for 1, 2, 4, 8 or 16 days. The meat pH, colour, amount of haem pigments, intramuscular fat, moisture, hydroxyproline content and sarcomere length were measured at 24 h post-mortem. Meat texture was measured by compression after each ageing time. The pH of the samples ranged from 5.50 to 5.58. Meat colour varied with breed and slaughter weight (P⩽0.01), the M. longissimus thoracis was lighter in the youngest animals and in the Churra breed and redder in Merinos. Intramuscular fat increased and moisture decreased for heavier lambs. Differences in collagen were associated with breed (P⩽0.01); total and insoluble collagen contents were higher in the Churra breed. Sarcomere length was only slightly affected by slaughter weight. Meat from the Churra breed had the highest values at high levels of compression. Suckling lambs (10-12 kg) had greater myofibrillar toughness than heavier lambs and ageing strongly influenced myofibrillar tenderness.

  16. Ultrafast terahertz modulation characteristic of tungsten doped vanadium dioxide nanogranular film revealed by time-resolved terahertz spectroscopy

    SciTech Connect

    Xiao, Yang; Zhai, Zhao-Hui; Zhu, Li-Guo E-mail: huangwanxia@scu.edu.cn; Li, Jun; Peng, Qi-Xian; Li, Ze-Ren; Shi, Qi-Wu; Huang, Wan-Xia E-mail: huangwanxia@scu.edu.cn; Yue, Fang; Hu, Yan-Yan

    2015-07-20

    The ultrafast terahertz (THz) modulation characteristic during photo-induced insulator-to-metal transition (IMT) of undoped and tungsten (W)-doped VO{sub 2} film was investigated at picoseconds time scale using time-resolved THz spectroscopy. W-doping slows down the photo-induced IMT dynamic processes (both the fast non-thermal process and the slow metallic phase propagation process) in VO{sub 2} film and also reduces the pump fluence threshold of photo-induced IMT in VO{sub 2} film. Along with the observed broadening of phase transition temperature window of IMT in W-doped VO{sub 2}, we conclude that W-doping prevents metallic phase domains from percolation. By further extracting carrier properties from photo-induced THz conductivity at several phase transition times, we found that the electron-electron correlation during IMT is enhanced in W-doped VO{sub 2}.

  17. Modal and characteristics-based approaches for modeling elastic waves induced by time-dependent boundary conditions

    NASA Astrophysics Data System (ADS)

    Lowe, Robert L.; John Yu, Sheng-Tao; Yang, Lixiang; Bechtel, Stephen E.

    2014-02-01

    In this paper, we present a characteristics-based approach for solving elastic wave problems with time-dependent traction boundary conditions. A generalized mathematical model for this important class of problems is expressed as a set of first-order, linear, hyperbolic partial differential equations. We analyze the mathematical structure of this first-order linear system, verify its hyperbolicity, derive its characteristic form, and deduce its eigenvalues, eigenvectors, and Riemann invariants. The eigenvalues correspond to the wave speeds, while the Riemann invariants are used to construct a solution by the method of characteristics. We benchmark the method of characteristics against several popular modal approaches. Two of these, which we refer to as the concentrated body force method (CBFM) and the homogeneous eigenfunction expansion method (HEEM), were developed to simplify the well-established but tedious Mindlin-Goodman method. To homogenize the boundary conditions and enable modal analysis, the CBFM and HEEM forgo the usual formalism of linear transformations (à la Mindlin-Goodman) in favor of intuitive modeling assumptions and postulated solution structures. We find, however, that these approaches introduce an artificial stress discontinuity at the forced boundary in their reformulated problems. When these reformulated problems are solved by modal analysis, spurious oscillations and significant overshoot, similar to the Gibbs phenomenon, emerge in the stress profile at the artificial discontinuity. We demonstrate that these oscillations and overshoot are physical manifestations of a series solution for stress, obtained from term-by-term differentiation, that is not uniformly convergent, as required by the formalism of mathematical analysis. The method of characteristics solution, on the other hand, is exact to within machine precision, yielding no artificial discontinuities, spurious oscillations, or unphysical overshoot. Unlike the modal approaches, the

  18. Characteristics of Settling Coral Reef Fish Are Related to Recruitment Timing and Success

    PubMed Central

    Rankin, Tauna L.; Sponaugle, Su

    2014-01-01

    Many marine populations exhibit high variability in the recruitment of young into the population. While environmental cycles and oceanography explain some patterns of replenishment, the role of other growth-related processes in influencing settlement and recruitment is less clear. Examination of a 65-mo. time series of recruitment of a common coral reef fish, Stegastes partitus, to the reefs of the upper Florida Keys revealed that during peak recruitment months, settlement stage larvae arriving during dark lunar phases grew faster as larvae and were larger at settlement compared to those settling during the light lunar phases. However, the strength and direction of early trait-mediated selective mortality also varied by settlement lunar phase such that the early life history traits of 2–4 week old recruit survivors that settled across the lunar cycle converged to more similar values. Similarly, within peak settlement periods, early life history traits of settling larvae and selective mortality of recruits varied by the magnitude of the settlement event: larvae settling in larger events had longer PLDs and consequently were larger at settlement than those settling in smaller pulses. Traits also varied by recruitment habitat: recruits surviving in live coral habitat (vs rubble) or areas with higher densities of adult conspecifics were those that were larger at settlement. Reef habitats, especially those with high densities of territorial conspecifics, are more challenging habitats for young fish to occupy and small settlers (due to lower larval growth and/or shorter PLDs) to these habitats have a lower chance of survival than they do in rubble habitats. Settling reef fish are not all equal and the time and location of settlement influences the likelihood that individuals will survive to contribute to the population. PMID:25250964

  19. Timing Effects of Heat-Stress on Plant Ecophysiological Characteristics and Growth

    PubMed Central

    Wang, Dan; Heckathorn, Scott A.; Mainali, Kumar; Tripathee, Rajan

    2016-01-01

    Heat-waves with higher intensity and frequency and longer durations are expected in the future due to global warming, which could have dramatic impacts in agriculture, economy and ecology. This field study examined how plant responded to heat-stress (HS) treatment at different timing in naturally occurring vegetation. HS treatment (5 days at 40.5°C) were applied to 12 1 m2 plots in restored prairie vegetation dominated by a warm-season C4 grass, Andropogon gerardii, and a warm-season C3 forb, Solidago canadensis, at different growing stages. During and after each heat stress (HS) treatment, temperature were monitored for air, canopy, and soil; net CO2 assimilation (Anet), quantum yield of photosystem II (ΦPSII), stomatal conductance (gs), and internal CO2 level (Ci), specific leaf area (SLA), and chlorophyll content of the dominant species were measured. One week after the last HS treatment, all plots were harvested and the biomass of above-ground tissue and flower weight of the two dominant species were determined. HS decreased physiological performance and growth for both species, with S. canadensis being affected more than A. gerardii, indicated by negative HS effect on both physiological and growth responses for S. canadensis. There were significant timing effect of HS on the two species, with greater reductions in the net photosynthetic rate and productivity occurred when HS was applied at later-growing season. The reduction in aboveground productivity in S. canadensis but not A. gerardii could have important implications for plant community structure by increasing the competitive advantage of A. gerardii in this grassland. The present experiment showed that HS, though ephemeral, may promote long-term effects on plant community structure, vegetation dynamics, biodiversity, and ecosystem functioning of terrestrial biomes when more frequent and severe HS occur in the future. PMID:27853463

  20. Characteristics of settling coral reef fish are related to recruitment timing and success.

    PubMed

    Rankin, Tauna L; Sponaugle, Su

    2014-01-01

    Many marine populations exhibit high variability in the recruitment of young into the population. While environmental cycles and oceanography explain some patterns of replenishment, the role of other growth-related processes in influencing settlement and recruitment is less clear. Examination of a 65-mo. time series of recruitment of a common coral reef fish, Stegastes partitus, to the reefs of the upper Florida Keys revealed that during peak recruitment months, settlement stage larvae arriving during dark lunar phases grew faster as larvae and were larger at settlement compared to those settling during the light lunar phases. However, the strength and direction of early trait-mediated selective mortality also varied by settlement lunar phase such that the early life history traits of 2-4 week old recruit survivors that settled across the lunar cycle converged to more similar values. Similarly, within peak settlement periods, early life history traits of settling larvae and selective mortality of recruits varied by the magnitude of the settlement event: larvae settling in larger events had longer PLDs and consequently were larger at settlement than those settling in smaller pulses. Traits also varied by recruitment habitat: recruits surviving in live coral habitat (vs rubble) or areas with higher densities of adult conspecifics were those that were larger at settlement. Reef habitats, especially those with high densities of territorial conspecifics, are more challenging habitats for young fish to occupy and small settlers (due to lower larval growth and/or shorter PLDs) to these habitats have a lower chance of survival than they do in rubble habitats. Settling reef fish are not all equal and the time and location of settlement influences the likelihood that individuals will survive to contribute to the population.

  1. The Impact of Ripening Time on Technological Quality Traits, Chemical Change and Sensory Characteristics of Dry-cured Loin

    PubMed Central

    Seong, Pil Nam; Park, Kyoung Mi; Kang, Geun Ho; Cho, Soo Hyun; Park, Beom Young; Van Ba, Hoa

    2015-01-01

    The effect of ripening time on the technological quality traits, fatty acid compositions and sensory characteristics of dry-cured loin was studied. Pork loins (n = 102) at 24 h post-mortem were used to produce dry-cured loins. The dry-cured loins were assessed at 30, 60, and 90 days of ripening for the aforementioned characteristics. Our results showed that the water activity (aw) decreased (p<0.05) up to 60 days and did not change thereafter. The lipid oxidation and weight loss levels significantly (p<0.05) increased with increased ripening time. The Commission Internationale de l’Eclairage (CIE) L* decreased for 90 days while CIE a* increased for 60 days and did not increase thereafter. More noticeably, the levels of most of unsaturated fatty acids and total polyunsaturated fatty acids significantly decreased as increasing ripening time up to 90 days. The 30 days-ripened loins had lower (p<0.05) color, flavor and overall acceptability scores than the loins ripened for 60 and 90 days, however, no differences in sensory traits occurred between the 60 and 90 day-ripened samples. Based on the results obtained in the present study, it is suggested that the ripening duration between 30 and 60 days could be more appropriate for producing dry-cured loin product with higher quality and economic benefits. PMID:25715685

  2. The Impact of Ripening Time on Technological Quality Traits, Chemical Change and Sensory Characteristics of Dry-cured Loin.

    PubMed

    Seong, Pil Nam; Park, Kyoung Mi; Kang, Geun Ho; Cho, Soo Hyun; Park, Beom Young; Van Ba, Hoa

    2015-05-01

    The effect of ripening time on the technological quality traits, fatty acid compositions and sensory characteristics of dry-cured loin was studied. Pork loins (n = 102) at 24 h post-mortem were used to produce dry-cured loins. The dry-cured loins were assessed at 30, 60, and 90 days of ripening for the aforementioned characteristics. Our results showed that the water activity (aw) decreased (p<0.05) up to 60 days and did not change thereafter. The lipid oxidation and weight loss levels significantly (p<0.05) increased with increased ripening time. The Commission Internationale de l'Eclairage (CIE) L* decreased for 90 days while CIE a* increased for 60 days and did not increase thereafter. More noticeably, the levels of most of unsaturated fatty acids and total polyunsaturated fatty acids significantly decreased as increasing ripening time up to 90 days. The 30 days-ripened loins had lower (p<0.05) color, flavor and overall acceptability scores than the loins ripened for 60 and 90 days, however, no differences in sensory traits occurred between the 60 and 90 day-ripened samples. Based on the results obtained in the present study, it is suggested that the ripening duration between 30 and 60 days could be more appropriate for producing dry-cured loin product with higher quality and economic benefits.

  3. Dynamical instability in surface permeability characteristics of building sandstones in response to salt accumulation over time

    NASA Astrophysics Data System (ADS)

    McCabe, S.; McKinley, J. M.; Gomez-Heras, M.; Smith, B. J.

    2011-07-01

    This paper explores how the surface permeability of sandstone blocks changes over time in response to repeated salt weathering cycles. Surface permeability controls the amount of moisture and dissolved salt that can penetrate in and facilitate decay. Connected pores permit the movement of moisture (and hence soluble salts) into the stone interior, and where areas are more or less permeable soluble salts may migrate along preferred pathways at differential rates. Previous research has shown that salts can accumulate in the near-surface zone and lead to partial pore blocking which influences subsequent moisture ingress and causes rapid salt accumulation in the near-surface zone. Two parallel salt weathering simulations were carried out on blocks of Peakmoor Sandstone of different volumes. Blocks were removed from simulations after 2, 5, 10, 20 and 60 cycles. Permeability measurements were taken for these blocks at a resolution of 20 mm, providing a grid of 100 permeability values for each surface. The geostatistical technique of ordinary kriging was applied to the data to produce a smoothed interpolation of permeability for these surfaces, and hence improve understanding of the evolution of permeability over time in response to repeated salt weathering cycles. Results illustrate the different responses of the sandstone blocks of different volumes to repeated salt weathering cycles. In both cases, after an initial subtle decline in the permeability (reflecting pore blocking), the permeability starts to increase — reflected in a rise in mean, maximum and minimum values. However, between 10 and 20 cycles, there is a jump in the mean and range permeability of the group A block surfaces coinciding with the onset of meaningful debris release. After 60 cycles, the range of permeability in the group A block surface had increased markedly, suggesting the development of a secondary permeability. The concept of dynamic instability and divergent behaviour is applied at the

  4. Effect of storage time and temperature on the physicochemical and sensory characteristics of commercial apricot jam.

    PubMed

    Touati, Noureddine; Tarazona-Díaz, Martha Patricia; Aguayo, Encarna; Louaileche, Hayette

    2014-02-15

    Storage conditions are important factors for jam quality. The objective of this study was to monitor the physicochemical stability and sensorial profile of apricot jam during storage for 60 days at 5 °C, 25 °C and 37 °C. For that purpose, special attention was paid to total soluble solids (TSS), titratable acidity (TA), colour, free amino acids (FAA), total sugars (TS) and hydroxymethylfurfural (HMF). The decreasing parameter for jam at the end of storage under 5 °C, 25 °C and 37 °C, respectively, were 16.81%, 34.30% and 56.01% for FAA, and 5.52%, 9.02% and 7.46% for TS; likewise, the increasing were 19.81%, 22.94% and 25.07% for TA, 3.15%, 4.08% and 4.47% for TSS, 15.96%, 112.76% and 150% for HMF. Jam stability was better at 5 °C than 25 °C and 37 °C. The interaction time-temperature factor had significant effects on pH, TS, FAA and HMF, unlike TA, TSS and sensorial profile.

  5. The time-frequency characteristics of violin vibrato: modal distribution analysis and synthesis

    PubMed

    Mellody; Wakefield

    2000-01-01

    A high-resolution time-frequency distribution, the modal distribution, is applied to the study of violin vibrato. The analysis indicates that the frequency modulation induced by the motion of the stopped finger on the string is accompanied by a significant amplitude variation in each partial of that note. Amplitude and frequency estimates for each partial are extracted from the modal distribution of ten pitches that span the range of the violin instrument. The frequency modulation is well-represented by a single sinusoid with a mean rate of 5.9 Hz and a mean excursion of +/- 15.2 cents. A spectral decomposition of the amplitude envelopes of the partials shows that the peaks lie primarily at integer multiples of the vibrato rate. These amplitude and frequency estimates are used in an additive synthesis model to generate synthetic replicates of violin vibrato. Simple approximations to these estimates are created, and synthesized sounds using these are evaluated perceptually by seven subjects using discrimination, nonmetric multidimensional scaling (MDS), and sound quality scoring tasks. It is found that the absence of frequency modulation has little effect on the perceptual response to violin vibrato, while the absence of amplitude modulation causes marked changes in both sound quality and MDS results. Low-order spectral decompositions of the amplitude and frequency estimates also occupy the same perceptual space as the original recording for a subset of the pitches studied.

  6. Time-dependent low-field MRI characteristics of canine blood: an in vitro study.

    PubMed

    Jeong, Jimo; Park, Sangjun; Jeong, Eunseok; Kim, Namsoo; Kim, Minsu; Jung, Yechan; Cho, Youngkwon; Lee, Kichang

    2016-03-01

    This study was conducted to assess time-sensitive magnetic resonance (MR) changes in canine blood using low-field MR. Arterial and venous blood samples were collected from eight healthy beagle dogs. Samples were placed in 5-mL tubes and imaged within 3 hours of collection at 1 day intervals from day 1 to day 30. The following sequences were used: T1-weighted (T1W), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR), short tau inversion recovery (STIR), and T2-star gradient-echo (T2(*)-GRE). Visual comparison of the images revealed that four relatively homogenous blood clots and twelve heterogeneous blood clots developed. The margination of the clot and plasma changed significantly on day 2 and day 13. On day 2, heterogeneous blood clots were differentiated into 2 to 3 signal layers in the T2W, T1W, and especially the STIR images. Hypointense signal layers were also detected in the blood clots in STIR images, which have T2 hypo, FLAIR hypo, and T1 hyper intense signals. In all images, these signal layers remained relatively unchanged until day 13. Overall, the results suggest that hematomas are complex on low-field MRI. Accordingly, it may not be feasible to accurately characterize hemorrhages and predict clot age based on low-field MRI.

  7. Breed, slaughter weight and ageing time effects on sensory characteristics of lamb.

    PubMed

    Martínez-Cerezo, S; Sañudo, C; Medel, I; Olleta, J L

    2005-03-01

    The longissimus lumborum (right and left) from 180 entire male lambs were tasted by a nine-member trained taste panel. The samples were from lambs from three Spanish breeds; Rasa Aragonesa (local meat breed), Churra (local dairy breed) and Spanish Merino. Within breed, three slaughter live weights were considered (10-12, 20-22 or 30-32 kg) and meat was aged in a vacuum package for 1, 2, 4, 8 or 16 days. Panellists assessed a total of eight descriptors. Lamb odour and lamb flavour intensities increased with slaughter weight. However, fat flavour intensity was significantly influenced by breed, with the highest score for Rasa Aragonesa. Off-flavour intensity was influenced by breed and ageing, with higher scores for Rasa Aragonesa and longer ageing times. Tenderness and juiciness were influenced by all three effects (P⩽0.001, each) and there was a significant interaction between breed and slaughter live weight. Meat was juicier and more tender in the lightest Churra lambs, and in the Spanish Merino lambs for the heavier weight animals. Tenderness and juiciness increased with ageing. The best quality flavour was for the Spanish Merino and the intermediate and heavier lambs.

  8. Time-spectral characteristics of large-scale cloud systems in the tropical Pacific.

    NASA Technical Reports Server (NTRS)

    Sikdar, D. N.; Young, J. A.; Suomi, V. E.

    1972-01-01

    Study of time series of areal cloud coverage over the central Pacific to determine the large-scale variations of tropical disturbance activity for a four-month period in 1967. The persistent and fluctuating components are found to be more prevalent in regions of high and low mean cloudiness, respectively, with major longitudinal variations in activity most evident in the Southern Hemisphere. Normalized power spectra show that the transient activity occurring in the equatorial zone is dominated by shorter periods of about four days, while longer periods are dominant away from the equator. Coherency magnitudes and phases between different locations indicate that propagating cloud systems are most identifiable at lower frequencies in the Southern Hemisphere, and at somewhat higher frequencies in the Northern Hemisphere. Activity with periods in excess of five days consists largely of both westward and eastward propagation on the planetary wave scale. The shorter periods appear to consist of both synoptic-scale and planetary-scale modes, with westward propagation dominant near the equator.

  9. Oil Sands Characteristics and Time-Lapse and P-SV Seismic Steam Monitoring, Athabasca, Canada

    NASA Astrophysics Data System (ADS)

    Takahashi, A.; Nakayama, T.; Kashihara, K.; Skinner, L.; Kato, A.

    2008-12-01

    -injection. The differences of the seismic responses between the time-lapse seismic volumes can be quantitatively explained by P-wave velocity decrease of the oil sands layers due to steam-injection. In addition, the data suggests that a larger area would be influenced by pressure than temperature. We calculate several seismic attributes such as RMS values of amplitude difference, maximum cross correlations, and interval velocity differences. These attributes are integrated by using self-organization maps (SOM) and K-means methods. By this analysis, we are able to distinguish areas of steam chamber growth from transitional and non-affected areas. In addition, 3D P-SV converted-wave processing and analysis are applied on the second 3D data set (recorded with three-component digital sensor). Low Vp/Vs values in the P-SV volume show areas of steam chamber development, and high Vp/Vs values indicate transitional zones. Our analysis of both time-lapse 3D seismic and 3D P-SV data along with the rock physics model can be used to monitor qualitatively and quantitatively the rock property changes of the inter-well reservoir sands in the field.

  10. Impacts of sludge retention time on sludge characteristics and membrane fouling in a submerged anaerobic-oxic membrane bioreactor.

    PubMed

    Zhang, Xiaomei; Yue, Xiuping; Liu, Zhiqiang; Li, Qingqing; Hua, Xiufu

    2015-06-01

    Anaerobic-oxic membrane bioreactor (AOMBR) has been proposed as a highly effective method in municipal and industrial wastewater treatment. In this study, according to the sewage treatment system in a campus, long-term experiments were conducted to assess the impacts of the sludge retention time (SRT) on sludge characteristics and membrane fouling, and the sludge parameters include biomass concentration, particle size distribution, extracellular polymeric substances (EPS), soluble microbial products (SMPs), and specific resistance to filtration (SRF). Our results clearly demonstrated that SRT was one of the most important factors influencing sludge characteristics, and different sludge characteristics resulted in different membrane fouling degrees. A better treatment and filtration performances were observed at the SRT of 30 days compared to two SRTs of 10 and 90 days. Among these parameters, SMP had the most significant correlation with the membrane fouling rate (dTMP/dt), and it had a negative impact on membrane filtration performance. The impact of SRT on membrane fouling process was discussed further by filtration models. At 10 days SRT, the complete-standard blocking model curve had a comparatively higher goodness-of-fit with the fouling process, and at 30 and 90 days SRT, the cake-standard blocking model curve had a relatively higher goodness-of-fit with respective fouling process.

  11. Multifractal characteristics of NDVI maps in space and time in the Community of Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Sotoca, Juan J. Martin; Saa-Requejo, Antonio; Grau, Juan B.; Tarquis, Ana M.

    2015-04-01

    Satellite information has contributed to improve our understanding of the spatial variability of hydro-climatic and ecological processes. Vegetation activity is tightly coupled with climate, hydro-ecological fluxes, and terrain dynamics in river basins at a wide range of space-time scales (Scheuring and Riedi, 1994). Indices of vegetation activity are constructed using satellite information of reflectance of the relevant spectral bands which enhance the contribution of vegetation being Normalized Difference Vegetation Index (NDVI) widely used. How can we study such a complex system? Multifractals and fractals are related techniques mainly used in physics to characterize the scaling behaviour of a system; they differ in that fractals look at the geometry of presence/absence patterns, while multifractals look at the arrangement of quantities such as population or biomass densities (Saravia et al., 2012). Scaling laws are an emergent general feature of ecological systems; they reflect constraints in their organization that can provide tracks about the underlying mechanisms (Solé and Bascompte, 2006). In this work, we have applied these techniques to study the spatial pattern through one year of NDVI maps. A rectangular area that includes the Community of Madrid and part of the surroundings, consisting of 300 x 280 pixels with a resolution of 500 x 500 m2 has been selected and monthly NDVI maps analyzed using the multifractal spectrum and the map of singularities (Cheng and Agterberg, 1996). The results show a cyclical pattern in the multifractal behaviour and singularity points related to river basin networks (Martín-Sotoca, 2014). References Cheng, Q. and Agterberg, F.P. (1996). Multifractal modeling and spatial statistics. Math. Geol. Vol 28, 1-16. Martín-Sotoca, J.J. (2014) Estructura Espacial de la Sequía en Pastos y sus Aplicaciones en el Seguro Agrario. Master Thesis, UPM (In Spanish). Saravia LA, Giorgi A, Momo F.: Multifractal growth in periphyton

  12. Rapidly differentiating grape seeds from different sources based on characteristic fingerprints using direct analysis in real time coupled with time-of-flight mass spectrometry combined with chemometrics.

    PubMed

    Song, Yuqiao; Liao, Jie; Dong, Junxing; Chen, Li

    2015-09-01

    The seeds of grapevine (Vitis vinifera) are a byproduct of wine production. To examine the potential value of grape seeds, grape seeds from seven sources were subjected to fingerprinting using direct analysis in real time coupled with time-of-flight mass spectrometry combined with chemometrics. Firstly, we listed all reported components (56 components) from grape seeds and calculated the precise m/z values of the deprotonated ions [M-H](-) . Secondly, the experimental conditions were systematically optimized based on the peak areas of total ion chromatograms of the samples. Thirdly, the seven grape seed samples were examined using the optimized method. Information about 20 grape seed components was utilized to represent characteristic fingerprints. Finally, hierarchical clustering analysis and principal component analysis were performed to analyze the data. Grape seeds from seven different sources were classified into two clusters; hierarchical clustering analysis and principal component analysis yielded similar results. The results of this study lay the foundation for appropriate utilization and exploitation of grape seed samples. Due to the absence of complicated sample preparation methods and chromatographic separation, the method developed in this study represents one of the simplest and least time-consuming methods for grape seed fingerprinting.

  13. The Influence of Pretreatment Characteristics and Radiotherapy Parameters on Time Interval to Development of Radiation-Associated Meningioma

    SciTech Connect

    Paulino, Arnold C.; Ahmed, Irfan M.; Mai, Wei Y.; Teh, Bin S.

    2009-12-01

    Purpose: To identify pretreatment characteristics and radiotherapy parameters which may influence time interval to development of radiation-associated meningioma (RAM). Methods and Materials: A Medline/PUBMED search of articles dealing with RAM yielded 66 studies between 1981 and 2006. Factors analyzed included patient age and gender, type of initial tumor treated, radiotherapy (RT) dose and volume, and time interval from RT to development of RAM. Results: A total of 143 patients with a median age at RT of 12 years form the basis of this report. The most common initial tumors or conditions treated with RT were medulloblastoma (n = 27), pituitary adenoma (n = 20), acute lymphoblastic leukemia (n = 20), low-grade astrocytoma (n = 19), and tinea capitis (n = 14). In the 116 patients whose RT fields were known, 55 (47.4%) had a portion of the brain treated, whereas 32 (27.6%) and 29 (25.0%) had craniospinal and whole-brain fields. The median time from RT to develop a RAM or latent time (LT) was 19 years (range, 1-63 years). Male gender (p = 0.001), initial diagnosis of leukemia (p = 0.001), and use of whole brain or craniospinal field (p <= 0.0001) were associated with a shorter LT, whereas patients who received lower doses of RT had a longer LT (p < 0.0001). Conclusions: The latent time to develop a RAM was related to gender, initial tumor type, radiotherapy volume, and radiotherapy dose.

  14. Digestibility, fecal characteristics, and plasma glucose and urea in dogs fed a commercial dog food once or three times daily

    PubMed Central

    Brambillasca, Sebastián; Purtscher, Frederick; Britos, Alejandro; Repetto, José L.; Cajarville, Cecilia

    2010-01-01

    Digestibility, fecal characteristics, and levels of glucose and urea in the plasma were determined in 8 dogs that received 2 different dog foods once or 3 times daily. One dog food (A) was 5 times more expensive than the other (B). Fecal pH and consistency, digestibility of dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) were determined. Blood samples were taken from 30 min before to 60 min after a meal. Digestibilities of DM, OM, and CP, and fecal consistency were higher, and daily fecal excretion and fecal pH were lower when dogs were fed food A (P < 0.001). The feeding schedule had no effect on plasma glucose and urea. Neither feeding frequency nor food × frequency interactions was significant for the parameters studied. PMID:20440906

  15. Engineering estimation of time-dependent deformation characteristics as bending moment relaxation and released unfolding motion of creased paperboard

    NASA Astrophysics Data System (ADS)

    Nagasawa, Sh

    2017-02-01

    Paperboards are recognized to be important raw materials for packaging industry due to their advantages such as high strength-to-weight ratio, recyclability. Regarding the development of advanced packaging materials and the requirement of smart formed products, a study of sheet’s response behaviour is necessary for expanding the advanced converting industry. After introducing a couple of past research works concerned crease technologies, a fundamental mechanisms of crease deformation is reviewed using the scoring depth and the folding angle of a paperboard. Since one of important forming characteristics is a time-dependent stress relaxation or time-delayed strain during a fold/unfold process, the author’s experimental approaches for estimating a short term (less than 10 seconds) dynamic deformation behaviour of creased paperboard are discussed.

  16. Investigation on broadband propagation characteristic of terahertz electromagnetic wave in anisotropic magnetized plasma in frequency and time domain

    SciTech Connect

    Tian, Yuan; Han, Yiping; Ai, Xia; Liu, Xiuxiang

    2014-12-15

    In this paper, we investigate the propagation of terahertz (THz) electromagnetic wave in an anisotropic magnetized plasma by JE convolution-finite difference time domain method. The anisotropic characteristic of the plasma, which leads to right-hand circularly polarized (RCP) and right-hand circularly polarized (LCP) waves, has been taken into account. The interaction between electromagnetic waves and magnetized plasma is illustrated by reflection and transmission coefficients for both RCP and LCP THz waves. The effects of both the magnetized plasma thickness and the external magnetized field are analyzed and numerical results demonstrate that the two factors could influence the THz wave greatly. It is worthy to note that besides the reflection and transmission coefficients in the frequency domain, the waveform of the electric field in the time domain varying with thicknesses and external magnetic fields for different polarized direction has been studied.

  17. Time evolution of the general characteristics and Cu retention capacity in an acid soil amended with a bentonite winery waste.

    PubMed

    Fernández-Calviño, David; Rodríguez-Salgado, Isabel; Pérez-Rodríguez, Paula; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel

    2015-03-01

    The effect of bentonite waste added to a "poor" soil on its general characteristic and copper adsorption capacity was assessed. The soil was amended with different bentonite waste concentrations (0, 10, 20, 40 and 80 Mg ha(-1)) in laboratory pots, and different times of incubation of samples were tested (one day and one, four and eight months). The addition of bentonite waste increased the pH, organic matter content and phosphorus and potassium concentrations in the soil, being stable for P and K, whereas the organic matter decreased with time. Additionally, the copper sorption capacity of the soil and the energy of the Cu bonds increased with bentonite waste additions. However, the use of this type of waste in soil presented important drawbacks for waste dosages higher than 20 Mg ha(-1), such as an excessive increase of the soil pH and an increase of copper in the soil solution.

  18. A characteristic space-time conservation element and solution element method for conservation laws II. Multidimensional extension

    NASA Astrophysics Data System (ADS)

    Shen, Hua; Wen, Chih-Yung

    2016-01-01

    The characteristic space-time conservation element and solution element (CE/SE) schemes proposed by Shen et al. (2015) [15] are straightforward extended to multidimensional schemes on 2D rectangular meshes which strictly follow the space-time conservation law. The schemes for solving both scalar conservation laws and compressible Euler equations with shock waves are developed. They are accurate and robust with CFL widely ranging from 0 to nearly 1. In Euler solvers, the frequently-used Harten, Lax and van Leer (HLL) Riemann solver, contact discontinuity restoring HLLC Riemann solver and Roe Riemann solver are employed to calculate the upwind fluxes as examples. When standard grid-aligned Riemann solvers are employed, the carbuncle phenomena are significantly suppressed when comparing with conventional upwind schemes. If rotated Riemann solvers are employed, nearly carbuncle-free results are obtained. Several well understood numerical examples are carried out to demonstrate that the 2D characteristic CE/SE schemes can simultaneously capture shocks and details of complex flow structures very well.

  19. Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage

    NASA Astrophysics Data System (ADS)

    Li, Xuebao; Cui, Xiang; Lu, Tiebing; Ma, Wenzuo; Bian, Xingming; Wang, Donglai; Hiziroglu, Huseyin

    2016-03-01

    The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.

  20. Change in working characteristics of the steam turbine metal with operating time of more than 330000 hours

    NASA Astrophysics Data System (ADS)

    Gladshteyn, V. I.; Troitskiy, A. I.

    2017-01-01

    Research of a metal of the stop valve case (SVC) of the K-300-23.5 LMZ turbine (steel grade 15Kh1M1FL), destroyed after operation for 331000 hours, is performed. It's chemical composition and properties are determined as follows: a short-term mechanical tensile stress at 20°C and at elevated temperature, critical temperature, fragility, critical crack opening at elevated temperature, and long-term strength. Furthermore, nature of the microstructure, packing density of carbide particles and their size, and chemical composition of carbide sediment are estimated. A manifestation of metal properties for the main case components by comparison with a forecast of the respective characteristics made for the operating time of 331000 hours is tested. Property-time relationships are built for the forecast using statistical treatment of the test results for the samples cut out from more than 300 parts. Representativeness of the research results is proved: the statistical treatment of their differences are within the range of ±5%. It has been found that, after 150000 hours of operation, only the tensile strength insignificantly depends on the operating time at 20°C, whereas indicators of strength at elevated temperature significantly reduce, depending on the operating time. A brittle-to-ductile transition temperature (BDTT) raises, a critical notch opening changes in a complicated way, a long-term strength reduces. It has been found empirically that the limit of a long-term strength of the SVC metal at 540°C and the operating time of 105 hours is almost 1.6 times less than the required value in the as-delivered state. It is possible to evaluate a service life of the operating valves with the operating time of more than 330000 hours with respect to the long-term strength of the metal taking into account the actual temperature and stress. Guidelines for the control of similar parts are provided.

  1. Timing of seasonal migration in mule deer: effects of climate, plant phenology, and life-history characteristics

    USGS Publications Warehouse

    Monteith, Kevin L.; Bleich, Vernon C.; Stephenson, Thomas R.; Pierce, Beck M.; Conner, Mary M.; Klaver, Robert W.; Bowyer, R. Terry

    2011-01-01

    Phenological events of plants and animals are sensitive to climatic processes. Migration is a life-history event exhibited by most large herbivores living in seasonal environments, and is thought to occur in response to dynamics of forage and weather. Decisions regarding when to migrate, however, may be affected by differences in life-history characteristics of individuals. Long-term and intensive study of a population of mule deer (Odocoileus hemionus) in the Sierra Nevada, California, USA, allowed us to document patterns of migration during 11 years that encompassed a wide array of environmental conditions. We used two new techniques to properly account for interval-censored data and disentangle effects of broad-scale climate, local weather patterns, and plant phenology on seasonal patterns of migration, while incorporating effects of individual life-history characteristics. Timing of autumn migration varied substantially among individual deer, but was associated with the severity of winter weather, and in particular, snow depth and cold temperatures. Migratory responses to winter weather, however, were affected by age, nutritional condition, and summer residency of individual females. Old females and those in good nutritional condition risked encountering severe weather by delaying autumn migration, and were thus risk-prone with respect to the potential loss of foraging opportunities in deep snow compared with young females and those in poor nutritional condition. Females that summered on the west side of the crest of the Sierra Nevada delayed autumn migration relative to east-side females, which supports the influence of the local environment on timing of migration. In contrast, timing of spring migration was unrelated to individual life-history characteristics, was nearly twice as synchronous as autumn migration, differed among years, was related to the southern oscillation index, and was influenced by absolute snow depth and advancing phenology of plants

  2. Luminescence and scintillation timing characteristics of (LuxGd2-x)SiO5:Ce single crystals

    NASA Astrophysics Data System (ADS)

    Yawai, Nattasuda; Chewpraditkul, Warut; Sakthong, Ongsa; Chewpraditkul, Weerapong; Wantong, Kriangkrai; Szczesniak, Tomasz; Swiderski, Lukasz; Moszynski, Marek; Sidletskiy, Oleg

    2017-02-01

    The luminescence and scintillation characteristics of cerium-doped lutetium-gadolinium orthosilicate (LuxGd2-xSiO5:Ce; x=0, 0.8, 1.8) single crystals were investigated. At 662 keV γ-rays, the light yield of 29,800±3000 ph MeV-1 obtained for Lu1.8Gd0.2SiO5:Ce is higher than that of 20,200±2000 and 11,800±1200 ph MeV-1 obtained for Lu0.8Gd1.2SiO5:Ce and Gd2SiO5:Ce, respectively. The fast component decay time of 32, 18 and 17 ns was measured in the scintillation decay of Gd2SiO5:Ce, Lu0.8Gd1.2SiO5:Ce and Lu1.8Gd0.2SiO5:Ce, respectively. The coincidence time spectra for 511 keV annihilation quanta were measured in reference to a fast BaF2 detector and time resolution was discussed in terms of a number of photoelectrons and decay time of the fast component. The mass attenuation coefficient for studied crystals at 60 and 662 keV γ-rays was also evaluated and discussed.

  3. Characteristic Time Model Validation

    DTIC Science & Technology

    1988-09-01

    combustors (Rizk and Mongia , 1986). The only practical m.thod for ascertaining the validity of these models it to develop a well defined experimental datum...layer around the recirculation zone found in the primary zone of a gas turbine combustor . Experi- mental results are used to investigate CTM parameters...Length Scale ....................................... 80 4.3.6 Relation of rsglobal to Combustors ............................... 80 4.4 Spray

  4. Space-time clustering analysis of wildfires: The influence of dataset characteristics, fire prevention policy decisions, weather and climate.

    PubMed

    Parente, Joana; Pereira, Mário G; Tonini, Marj

    2016-07-15

    The present study focuses on the dependence of the space-time permutation scan statistics (STPSS) (1) on the input database's characteristics and (2) on the use of this methodology to assess changes on the fire regime due to different type of climate and fire management activities. Based on the very strong relationship between weather and the fire incidence in Portugal, the detected clusters will be interpreted in terms of the atmospheric conditions. Apart from being the country most affected by the fires in the European context, Portugal meets all the conditions required to carry out this study, namely: (i) two long and comprehensive official datasets, i.e. the Portuguese Rural Fire Database (PRFD) and the National Mapping Burnt Areas (NMBA), respectively based on ground and satellite measurements; (ii) the two types of climate (Csb in the north and Csa in the south) that characterizes the Mediterranean basin regions most affected by the fires also divide the mainland Portuguese area; and, (iii) the national plan for the defence of forest against fires was approved a decade ago and it is now reasonable to assess its impacts. Results confirmed (1) the influence of the dataset's characteristics on the detected clusters, (2) the existence of two different fire regimes in the country promoted by the different types of climate, (3) the positive impacts of the fire prevention policy decisions and (4) the ability of the STPSS to correctly identify clusters, regarding their number, location, and space-time size in spite of eventual space and/or time splits of the datasets. Finally, the role of the weather on days when clustered fires were active was confirmed for the classes of small, medium and large fires.

  5. Sex differences in anthropometric characteristics, motor and cognitive functioning in preschool children at the time of school enrolment.

    PubMed

    Bala, Gustav; Katić, Ratko

    2009-12-01

    The study included a sample of 333 preschool children (162 male and 171 female) at the time of school enrolment. Study subjects were recruited from the population of children in kindergartens in the cities of Novi Sad, Sombor, Sremska Mitrovica and Backa Palanka (Province of Voivodina, Serbia). Eight anthropometric variables, seven motor variables and one cognitive variable were analyzed to identify quantitative and qualitative sex differences in anthropometric characteristics, motor and cognitive functioning. Study results showed statistically significant sex differences in anthropometric characteristics and motor abilities in favor of male children, whereas no such difference was recorded in cognitive functioning. Sex differences found in morphological and motor spaces contributed to structuring proper general factors according to space and sex. Somewhat stronger structures were observed in male children. The cognitive aspect of functioning yielded better correlation with motor functioning in female than in male children. Motor functioning correlated better with morphological growth and development in male children, whereas cognitive functioning was relatively independent. These results are not fully in accordance with the current concept of general conditions in preschool children, nor they fully confirm the theory of integral development of children, hence they should be re-examined in future studies. Although these study results cannot be applied to sports practice in general, since we believe that it is too early for preschool children to take up sports and sport competitions, they are relevant for pointing to the need of developing general motor ability and motor behavior in preschool children.

  6. Listening to different speakers: on the time-course of perceptual compensation for vocal-tract characteristics.

    PubMed

    Sjerps, Matthias J; Mitterer, Holger; McQueen, James M

    2011-12-01

    This study used an active multiple-deviant oddball design to investigate the time-course of normalization processes that help listeners deal with between-speaker variability. Electroencephalograms were recorded while Dutch listeners heard sequences of non-words (standards and occasional deviants). Deviants were [ipapu] or [ɛpapu], and the standard was [(I)(ɛ)papu], where [(I)(ɛ)] was a vowel that was ambiguous between [ɛ] and [i]. These sequences were presented in two conditions, which differed with respect to the vocal-tract characteristics (i.e., the average 1st formant frequency) of the [papu] part, but not of the initial vowels [i], [ɛ] or [(I)(ɛ)] (these vowels were thus identical across conditions). Listeners more often detected a shift from [(I)(ɛ)papu] to [ɛpapu] than from [(I)(ɛ)papu] to [ipapu] in the high F(1) context condition; the reverse was true in the low F(1) context condition. This shows that listeners' perception of vowels differs depending on the speaker's vocal-tract characteristics, as revealed in the speech surrounding those vowels. Cortical electrophysiological responses reflected this normalization process as early as about 120 ms after vowel onset, which suggests that shifts in perception precede influences due to conscious biases or decision strategies. Listeners' abilities to normalize for speaker-vocal-tract properties are for an important part the result of a process that influences representations of speech sounds early in the speech processing stream.

  7. An Examination of the Transition of Fracture Characteristics in Long Bones from Fresh to Dry in Central Florida: Evaluating the Timing of Injury.

    PubMed

    Green, Ashley E; Schultz, John J

    2017-03-01

    It is important to conduct timing of injury research analyzing fracture characteristics at known postmortem intervals (PMI) because bone can retain fresh characteristics throughout the PMI. Defleshed pig (Sus scrofa) long bones were fractured weekly in two environments (full sun and shade) over 14 weeks in Central Florida and fracture characteristics were categorized (N = 136) for analysis. Results of analysis of variance (ANOVA) using time in weeks (PMI) as a dependent variable indicate significant relationships between PMI and Fracture Angle (p < 0.001), Fracture Surface (p < 0.001), and Fracture Outline (p < 0.001). Fracture characteristics associated with perimortem trauma (smooth Fracture Surfaces and curved or V-shaped Fracture Outlines) were commonly observed. Analysis of fracture characteristics for each environment demonstrated similar patterns. Overall, the loss of only fresh fracture characteristics for each bone was noted earlier in the PMI for the Central Florida region than previously reported.

  8. Effects of ramp slope on physiological characteristic and performance time of healthy adults propelling and pushing wheelchairs.

    PubMed

    Choi, Young Oh; Lee, Ho Young; Lee, Myoung Hee; Kwon, Oh Hyun

    2015-01-01

    [Purpose] This study examined the effects of ramp slope (1:12, 1:10, 1:8, and 1:6) on physiological characteristics and performance times of wheelchair users and the performance times of caregivers to determine which slope would be the best for wheelchairs, in order to propose a ramp slope that incorporates a universal design. [Subjects and Methods] Twenty-four healthy subjects were enrolled in this study. Fifteen of these subjects also volunteered to participate as caregivers. A wooden ramp with an adjustable slope was constructed. As manual wheelchair users, the participants performed propulsion of a wheelchair up the ramp at a self-selected pace. Four ramp slopes (1:12, 1:10, 1:8, and 1:6) were used, and the participants sequentially ascended them in order from the gentlest to the steepest slope. The caregivers also pushed a wheelchair up the ramp at a self-selected pace. The blood pressure and pulse of participants after the ascent, as well as the performance times of the caregivers and manual wheelchair users, were measured on each of the different ramp slopes. The measured data, pulse, blood pressure, and performance time, were analyzed using repeated ANOVA. [Results] Systolic blood pressure was significantly higher after ascending the 1:6 slope than after ascending the 1:12 and 1:8 slopes. Diastolic blood pressure was significantly higher after ascending the 1:6 slope than after ascending the 1:12 and 1:8 slopes. The participants' pulses tended to increase significantly with an increase in slope. An assessment of the propulsion performance times revealed significant differences among the slopes. [Conclusion] Considering the results of the wheelchair users and caregivers, the 1:12 and 1:10 slopes are suitable ramp slopes for wheelchairs.

  9. Predictive factors in patients with hepatocellular carcinoma receiving sorafenib therapy using time-dependent receiver operating characteristic analysis

    PubMed Central

    Nishikawa, Hiroki; Nishijima, Norihiro; Enomoto, Hirayuki; Sakamoto, Azusa; Nasu, Akihiro; Komekado, Hideyuki; Nishimura, Takashi; Kita, Ryuichi; Kimura, Toru; Iijima, Hiroko; Nishiguchi, Shuhei; Osaki, Yukio

    2017-01-01

    Aims: To investigate variables before sorafenib therapy on the clinical outcomes in hepatocellular carcinoma (HCC) patients receiving sorafenib and to further assess and compare the predictive performance of continuous parameters using time-dependent receiver operating characteristics (ROC) analysis. Patients and methods: A total of 225 HCC patients were analyzed. We retrospectively examined factors related to overall survival (OS) and progression free survival (PFS) using univariate and multivariate analyses. Subsequently, we performed time-dependent ROC analysis of continuous parameters which were significant in the multivariate analysis in terms of OS and PFS. Total sum of area under the ROC in all time points (defined as TAAT score) in each case was calculated. Results: Our cohort included 175 male and 50 female patients (median age, 72 years) and included 158 Child-Pugh A and 67 Child-Pugh B patients. The median OS time was 0.68 years, while the median PFS time was 0.24 years. On multivariate analysis, gender, body mass index (BMI), Child-Pugh classification, extrahepatic metastases, tumor burden, aspartate aminotransferase (AST) and alpha-fetoprotein (AFP) were identified as significant predictors of OS and ECOG-performance status, Child-Pugh classification and extrahepatic metastases were identified as significant predictors of PFS. Among three continuous variables (i.e., BMI, AST and AFP), AFP had the highest TAAT score for the entire cohort. In subgroup analyses, AFP had the highest TAAT score except for Child-Pugh B and female among three continuous variables. Conclusion: In continuous variables, AFP could have higher predictive accuracy for survival in HCC patients undergoing sorafenib therapy. PMID:28261338

  10. Experimental measure of transmission characteristics of low-frequency surface plasmon polaritons in frequency and time domains.

    PubMed

    Hou, Da Jun; Wu, Jin-Jei; Wu, Chien-Jang; Shen, Jian Qi; Chiueh, Her-Lih; Cheng, Li-Yi; Lin, Hung-Erh

    2016-04-04

    In this work, based on the use of the concept of spoof surface plasmon polaritons (spoof SPPs), we propose a novel kind of microstrips to suppress the interference between bended parallel microstrips. This novel structure is implemented by introducing subwavelength periodic structures onto the sides of a conventional microstrip. We numerically analyze the transmission characteristics of such new microstrips. We also measure the suppression arising from crosstalk between the bended corrugated microstrip and the conventional microstrip in both frequency and time domains. Experimental results show that such transmission line structure has superb interference restraining properties. Additionally, transmission properties have been investigated using circuit model. It is found that the coupling effect between the corrugated microstrip and the conventional microstrip can be efficiently suppressed in high speed digital signal transmission application.

  11. Studies on Liquefaction Time and Proteins Involved in the Improvement of Seminal Characteristics in Dromedary Camels (Camelus dromedarius).

    PubMed

    Mal, Gorakh; Vyas, Sumant; Srinivasan, Alagiri; Patil, Nitin Vasant Rao; Pathak, Krishan Murari Lal

    2016-01-01

    Semen was collected from six dromedary camels using artificial vagina during rutting season. Liquefaction of the viscous semen occurred in 23.89 ± 1.49 h. During liquefaction, proteins with molecular masses of 24.55 kDa and 22.07 kDa appeared in conjunction with the disappearance of intact 26.00 kDa protein after 18-24 h. These proteins were identified as β-nerve growth factors (β-NGFs) in liquefied camel semen. Guanidine-HCL improves the rheological characteristics of dromedary camel semen along with significant (P < 0.01) increase in sperm motility. No significant differences were found in viability of spermatozoa indicating no visible detrimental effects on spermatozoa. The cause of semen viscosity, as well as proteins that are present in liquefied dromedary camel seminal plasma, is described for the first time.

  12. Studies on Liquefaction Time and Proteins Involved in the Improvement of Seminal Characteristics in Dromedary Camels (Camelus dromedarius)

    PubMed Central

    Mal, Gorakh; Vyas, Sumant; Srinivasan, Alagiri; Patil, Nitin Vasant Rao; Pathak, Krishan Murari Lal

    2016-01-01

    Semen was collected from six dromedary camels using artificial vagina during rutting season. Liquefaction of the viscous semen occurred in 23.89 ± 1.49 h. During liquefaction, proteins with molecular masses of 24.55 kDa and 22.07 kDa appeared in conjunction with the disappearance of intact 26.00 kDa protein after 18–24 h. These proteins were identified as β-nerve growth factors (β-NGFs) in liquefied camel semen. Guanidine-HCL improves the rheological characteristics of dromedary camel semen along with significant (P < 0.01) increase in sperm motility. No significant differences were found in viability of spermatozoa indicating no visible detrimental effects on spermatozoa. The cause of semen viscosity, as well as proteins that are present in liquefied dromedary camel seminal plasma, is described for the first time. PMID:27022505

  13. Impacts of sludge retention time on sludge characteristics and membrane fouling in a submerged osmotic membrane bioreactor.

    PubMed

    Wang, Xinhua; Chen, Yao; Yuan, Bo; Li, Xiufen; Ren, Yueping

    2014-06-01

    Sludge retention time (SRT) is a feasible method to alleviate the salt accumulation in the osmotic membrane bioreactor (OMBR) by discharging the waste activated sludge. In this study, effects of SRT on sludge characteristics and membrane fouling were investigated using a submerged OMBR under two SRTs of 10 and 15d. The results showed that the lower SRT was helpful for alleviating the salt accumulation and flux decline. Besides that, the removal of NH3-N was significantly influenced by SRT. SRT also had a strong effect on soluble microbial products (SMP) and microbial activity due to the variation of salinity. Microbial diversity analysis indicated that the high salinity environment in the OMBR significantly affected the microbial communities. The flux decline in the OMBR was mainly attributed to the reduced driving force resulting from the salt accumulation, and the reversible fouling was the dominant forward osmosis (FO) membrane fouling in the OMBR.

  14. Real-time microseismic monitoring and its characteristic analysis in working face with high-intensity mining

    NASA Astrophysics Data System (ADS)

    Li, Yang; Yang, Tian-Hong; Liu, Hong-Lei; Wang, Hong; Hou, Xian-Gang; Zhang, Peng-Hai; Wang, Pei-Tao

    2016-09-01

    Xiaojihan coal mine is a typical high-intensity mining in Western China. The real-time monitoring of deformation and failure for the working face was carried out by using IMS microseismic monitoring system. The change process of microseismic parameters such as microseismic event rate, energy release, apparent volume, energy index, Schmidt number, b value and coefficient of seismic response and the relationships with the surrounding rock failure were studied. This research indicates that some parameters have obvious precursory characteristics before the large scale failure. The predictive periods were divided by these parameters, and Schmidt number has the highest predictive sensitivity, b value the second, energy index the third. Coefficient of seismic response and energy release have no direct contact with the excavation volume of ore body, but depend on the mine pressure behavior of working face.

  15. Demographic and HIV-specific characteristics of participants enrolled in the INSIGHT Strategic Timing of AntiRetroviral Treatment trial

    PubMed Central

    Sharma, S; Babiker, AG; Emery, S; Gordin, FM; Lundgren, JD; Neaton, JN; Bakowska, E; Schechter, M; Wiselka, MJ; Wolff, MJ

    2014-01-01

    Objectives The risks and benefits of initiating antiretroviral treatment (ART) at high CD4 cell counts have not been reliably quantified. The Strategic Timing of AntiRetroviral Treatment (START) study is a randomised international clinical trial that compares immediate with deferred initiation of ART for HIV-positive individuals with CD4 cell counts above 500 cells/μL. We describe the demographics, HIV-specific characteristics and medical history of this cohort. Methods Data collected at baseline include demographics, HIV-specific laboratory values, prior medical diagnoses and concomitant medications. Baseline characteristics were compared by geographical region, gender, and age. Results START enrolled 4685 HIV-positive participants from 215 sites in 35 countries. The median age is 36 years (IQR: 29-44), 27% are female, 45% self-identify as white, 30% black, 14% Latino/Hispanic, 8% Asian and 3% other. HIV acquisition is reported as 55% men who have sex with men, 38% heterosexual sex, 1% injecting drug use, and 5% other/unknown. Median time since HIV diagnosis is 1.0 year (IQR: 0.4-3.0) and the median CD4 and HIV RNA values at study entry are 651 cells/μL (584-765) and 12,754 copies/mL (IQR: 3,014-43,607), respectively. Conclusion START has enrolled a diverse group of ART-naïve individuals with high CD4 cell counts who are comparable to the HIV-positive population from the regions they were enrolled. The information collected with this robust study design will provide a database to evaluate the risks and benefits of early ART use for many important outcomes. PMID:25711321

  16. Characteristic length scales and time-averaged transport velocities of suspended sediment in the mid-Atlantic Region, USA

    USGS Publications Warehouse

    Pizzuto, James; Schenk, Edward R.; Hupp, Cliff R.; Gellis, Allen; Noe, Greg; Williamson, Elyse; Karwan, Diana L.; O'Neal, Michael; Marquard, Julia; Aalto, Rolf; Newbold, Denis

    2014-01-01

    Watershed Best Management Practices (BMPs) are often designed to reduce loading from particle-borne contaminants, but the temporal lag between BMP implementation and improvement in receiving water quality is difficult to assess because particles are only moved downstream episodically, resting for long periods in storage between transport events. A theory is developed that describes the downstream movement of suspended sediment particles accounting for the time particles spend in storage given sediment budget data (by grain size fraction) and information on particle transit times through storage reservoirs. The theory is used to define a suspended sediment transport length scale that describes how far particles are carried during transport events, and to estimate a downstream particle velocity that includes time spent in storage. At 5 upland watersheds of the mid-Atlantic region, transport length scales for silt-clay range from 4 to 60 km, while those for sand range from 0.4 to 113 km. Mean sediment velocities for silt-clay range from 0.0072 km/yr to 0.12 km/yr, while those for sand range from 0.0008 km/yr to 0.20 km/yr, 4–6 orders of magnitude slower than the velocity of water in the channel. These results suggest lag times of 100–1000 years between BMP implementation and effectiveness in receiving waters such as the Chesapeake Bay (where BMPs are located upstream of the characteristic transport length scale). Many particles likely travel much faster than these average values, so further research is needed to determine the complete distribution of suspended sediment velocities in real watersheds.

  17. Characteristics of a fast rise time power supply for a pulsed plasma reactor for chemical vapor destruction

    SciTech Connect

    Lawless, P.A.; Yamamoto, Toshiaki; Shofran, S.P.; Boss, C.B.; Nunez, C.M.; Ramsey, G.H.; Engels, R.L.

    1996-11-01

    Rotating spark gap devices for switching high-voltage direct current (dc) into a corona plasma reactor can achieve pulse rise times in the range of tens of nanoseconds. The fast rise times lead to vigorous plasma generation without sparking at instantaneous applied voltages higher than can be obtained with dc. The resulting energetic plasma is effective for destroying a variety of molecules. The spark gap circuit configuration plays an important role in the effectiveness of the plasma generation. A single-gap circuit is effective for generating moderate peak voltages, but is limited by a multiple sparking phenomenon. A double-gap circuit can achieve equal peak voltages with every spark, but with a reduced number of pulses, compared to the single gap. Both configurations have an upper voltage imposed by the changing impedance of the reactor as voltage and frequency are varied. The pulse characteristics are reported for both types of circuits. The general performance of the reactors for destruction of some compounds with both circuits is also reported.

  18. Time-dependent of characteristics of Cu/CuS/n-GaAs/In structure produced by SILAR method

    SciTech Connect

    Sağlam, M.; Güzeldir, B.

    2016-09-15

    Highlights: • The CuS thin film used at Cu/n-GaAs structure is grown by SILAR method. • There has been no report on ageing of characteristics of this junction in the literature. • The properties of Cu/CuS/n-GaAs/In structure are examined with different methods. • It has been shown that Cu/CuS/n-GaAs/In structure has a stable interface. - Abstract: The aim of this study is to explain effects of the ageing on the electrical properties of Cu/n-GaAs Shottky barrier diode with Copper Sulphide (CuS) interfacial layer. CuS thin films are deposited on n-type GaAs substrate by Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The structural and the morphological properties of the films have been carried out by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) techniques. The XRD analysis of as-grown films showed the single-phase covellite, with hexagonal crystal structure built around two preferred orientations corresponding to (102) and (108) atomic planes. The ageing effects on the electrical properties of Cu/CuS/n-GaAs/In structure have been investigated. The current–voltage (I–V) measurements at room temperature have been carried out to study the change in electrical characteristics of the devices as a function of ageing time. The main electrical parameters, such as ideality factor (n), barrier height (Φ{sub b}), series resistance (R{sub s}), leakage current (I{sub 0}), and interface states (N{sub ss}) for this structure have been calculated. The results show that the main electrical parameters of device remained virtually unchanged.

  19. Storage characteristics, nutritive value, and fermentation characteristics of alfalfa packaged in large-round bales and wrapped in stretch film after extended time delays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The production of baled silage is attractive to producers because it offers advantages over dry hay, particularly by limiting risks associated with wet or unstable weather conditions. Our objectives were to test the effects of delayed wrapping on silage fermentation, storage characteristics, and the...

  20. Timing of nest vegetation measurement may obscure adaptive significance of nest-site characteristics: A simulation study.

    PubMed

    McConnell, Mark D; Monroe, Adrian P; Burger, Loren Wes; Martin, James A

    2017-02-01

    Advances in understanding avian nesting ecology are hindered by a prevalent lack of agreement between nest-site characteristics and fitness metrics such as nest success. We posit this is a result of inconsistent and improper timing of nest-site vegetation measurements. Therefore, we evaluated how the timing of nest vegetation measurement influences the estimated effects of vegetation structure on nest survival. We simulated phenological changes in nest-site vegetation growth over a typical nesting season and modeled how the timing of measuring that vegetation, relative to nest fate, creates bias in conclusions regarding its influence on nest survival. We modeled the bias associated with four methods of measuring nest-site vegetation: Method 1-measuring at nest initiation, Method 2-measuring at nest termination regardless of fate, Method 3-measuring at nest termination for successful nests and at estimated completion for unsuccessful nests, and Method 4-measuring at nest termination regardless of fate while also accounting for initiation date. We quantified and compared bias for each method for varying simulated effects, ranked models for each method using AIC, and calculated the proportion of simulations in which each model (measurement method) was selected as the best model. Our results indicate that the risk of drawing an erroneous or spurious conclusion was present in all methods but greater with Method 2 which is the most common method reported in the literature. Methods 1 and 3 were similarly less biased. Method 4 provided no additional value as bias was similar to Method 2 for all scenarios. While Method 1 is seldom practical to collect in the field, Method 3 is logistically practical and minimizes inherent bias. Implementation of Method 3 will facilitate estimating the effect of nest-site vegetation on survival, in the least biased way, and allow reliable conclusions to be drawn.

  1. Studies of ambient noise in shallow water environments off Mexico and Alaska: characteristics, metrics and time-synchronization applications

    NASA Astrophysics Data System (ADS)

    Guerra, Melania

    Sound in the ocean originates from multiple mechanisms, both natural and anthropogenic. Collectively, underwater ambient noise accumulates valuable information about both its sources and the oceanic environment that propagates this noise. Characterizing the features of ambient noise source mechanisms is challenging, but essential, for properly describing an acoustic environment. Disturbances to a local acoustic environment may affect many aquatic species that have adapted to be heavily dependent on this particular sense for survival functions. In the case of marine mammals, which are federally protected, demand exists for understanding such potential impacts, which drives important scientific efforts that utilize passive acoustic monitoring (PAM) tools to inform regulatory decisions. This dissertation presents two independent studies that use PAM data to investigate the characteristics of source mechanisms that dominate ambient noise in two diverse shallow water environments. The study in Chapter 2 directly addresses the concern of how anthropogenic activities can degrade the effectiveness of PAM. In the Alaskan Beaufort Sea, an environment where ambient noise is normally dominated by natural causes, seismic surveys create impulsive sounds to map the composition of the bottom. By inspecting single-sensor PAM data, the spectral characteristics of seismic survey airgun reverberation are measured, and their contribution to the overall ambient noise is quantified. This work is relevant to multiple ongoing mitigation protocols that rely on PAM to acoustically detect marine mammal presence during industrial operations. Meanwhile, Chapter 3 demonstrates that by analyzing data from multiple PAM sensors, features embedded in both directional and omnidirectional ambient noise can be used to develop new time-synchronization processing techniques for aligning autonomous elements of an acoustic array, a tool commonly used in PAM for detecting and tracking marine mammals. Using

  2. Effects of 2HZ Imposed Bulk Flow Unsteadiness on Laminar/Turbulent Transition in a Straight Channel

    DTIC Science & Technology

    1989-12-01

    stainless steel tube ( hypodermic needle ) which allows the wire to move freely. The smoke wire is connected to an A/C-D/C converter and this in turn has...describe the onset of transition is the Reynolds number. In channel flows, linear stability theory predicts that the laminar flow becomes unstable to...linear theory indicates that the flow is stable. Experimental clarification of these points is needed, along with the verification of the sequence of

  3. Dynamic characteristics of a coastal area of lateral spreading using ambient noise time series - Anchor Bay, Malta

    NASA Astrophysics Data System (ADS)

    Galea, Pauline; D'Amico, Sebastiano; Farrugia, Daniela

    2013-04-01

    Anchor Bay and surrounding regions are located on the northwest coast of the island of Malta, Central Mediterranean. The area is characterized by a coastal cliff environment having an outcropping layer of hard coralline limestone (UCL) resting on a thick (up to 50m) layer of clays and marls (Blue Clay, BC). This configuration gives rise to a number of processes leading to coastal instability, in particular lateral spreading phenomena and rock falls. Previous and ongoing studies have identified both lateral spreading rates and vertical motions of up to 27mm per year (Mantovani et al, 2012). The area is an interesting natural laboratory as coastal detachment processes in a number of different stages can be identified and are easily accessible. We investigate the site dynamic characteristics of this study area by recording ambient noise time series (20 minutes long) at over 20 points, over an area of 0.07 km2, using a portable 3-component seismograph (Tromino ) The time series are processed to give both horizontal-to-vertical spectral ratio graphs (HVSR) as well as frequency-dependent polarisation analysis as proposed by Burjanek (2011, 2012). The HVSR graphs illustrate and quantify aspects of site resonance effects due both to underlying geology as well as to mechanical resonance of partly or wholly detached boulders or blocks. The polarization diagrams indicate predominant directions of vibrational effects. Results from this study show an unambiguous distinction between the behavior of "stable" areas, away from the cliff edges, the region of the unstable cliff edge and the actual rockfall areas. Stable regions are characterized by a single and pronounced HVSR resonance peak at around 1.5Hz that are characteristic of all other areas in the Maltese islands having the same underlying geological sequence, while HVSR curves closer to the cliff edge show more complex responses at higher frequencies characteristic of the dynamic behavior of individual detached blocks

  4. Exploring changes over time and characteristics associated with data retrieval across individual participant data meta-analyses: systematic review.

    PubMed

    Nevitt, Sarah J; Marson, Anthony G; Davie, Becky; Reynolds, Sally; Williams, Lisa; Smith, Catrin Tudur

    2017-04-05

    Objective To investigate whether the success rate of retrieving individual participant data (IPD) for use in IPD meta-analyses has increased over time, and to explore the characteristics associated with IPD retrieval.Design Systematic review of published IPD meta-analyses, supplemented by a reflection of the Cochrane Epilepsy Group's 20 years' experience of requesting IPD.Data sources Medline, CENTRAL, Scopus, Web of Science, CINAHL Plus, and PsycINFO.Eligibility criteria for study selection IPD meta-analyses of studies of all designs and all clinical areas published in English.Results 760 IPD meta-analyses which identified studies by systematic methods that had been published between 1987 and 2015 were included. Only 188 (25%) of these IPD meta-analyses retrieved 100% of the eligible IPD for analysis, with 324 (43%) of these IPD meta-analyses retrieving 80% or more of relevant IPD. There is insufficient evidence to suggest that IPD retrieval rates have improved over time. IPD meta-analyses that included only randomised trials, had an authorship policy, included fewer eligible participants, and were conducted outside of the Cochrane Database of Systematic Reviews were associated with a high or complete IPD retrieval rate. There was no association between the source of funding of the IPD meta-analyses and IPD retrieval rate. The IPD retrieval rate of the Cochrane Epilepsy Group has declined from 83% (up to 2005) to 65% (between 2012 and 2015) and the reported reasons for lack of data availability have changed in recent years.Conclusions IPD meta-analyses are considered to be the "gold standard" for the synthesis of data from clinical research studies; however, only 25% of published IPD meta-analyses have had access to all IPD.

  5. Time-dependent adaptations to posture and movement characteristics during the development of repetitive reaching induced fatigue.

    PubMed

    Fuller, Jason R; Fung, Joyce; Côté, Julie N

    2011-05-01

    Repetitive movements are common to many daily activities but often lead to the development of fatigue. We have previously shown that fatigue leads to changes in tridimensional spatial characteristics of the whole body. However, temporal aspects of these posture and movement adaptations have yet to be investigated. Healthy subjects (N = 14) performed a continuous reaching task by pointing between two targets placed at shoulder height, at 100 and 30% arm's length, anterior to the subject's midline until fatigue (assessed using the Borg CR-10 scale). Whole body kinematics and upper Trapezius EMG were recorded and analyzed at 1-min intervals to document the progression of fatigue on outcome variables. For all upper limb and postural variables analyzed, changes began to occur approximately midway to fatigue and were followed by an increase in Trapezius activity from baseline. Reach-to-reach variability of joint average positions and range of motion (ROM) increased in multiple directions for shoulder and elbow parameters. Reach-to-reach variability of the center-of-mass ROM also increased in several directions. Changes were also observed in within-movement inter-segmental timing. The peak velocities of elbow and endpoint occurred closer together in time during fatigue while the shoulder peak velocity occurrence showed a greater reach-to-reach variability. Our results suggest that the effects of fatigue on repetitive movement kinematics can be observed across three temporal dimensions of the task: (1) within individual movements, (2) from one movement to the next, and (3) as fatigue develops. Each observed change is discussed as a potential contributor to task-specific control strategies to prolong task performance.

  6. Clinical characteristics of bacteremia caused by Helicobacter cinaedi and time required for blood cultures to become positive.

    PubMed

    Araoka, Hideki; Baba, Masaru; Kimura, Muneyoshi; Abe, Masahiro; Inagawa, Hiroko; Yoneyama, Akiko

    2014-05-01

    The aim of this study was to clarify the clinical characteristics of patients with Helicobacter cinaedi bacteremia and the time required for blood cultures to become positive. The medical records of all patients with H. cinaedi bacteremia at Toranomon Hospital and Toranomon Hospital Kajigaya between March 2009 and March 2013 were retrospectively reviewed. Sixty-three patients, 34 men and 29 women with a median age of 67 years (range, 37 to 88 years), were diagnosed with H. cinaedi bacteremia. A total of 51,272 sets of blood cultures were obtained during the study period, of which 5,769 sets of blood cultures were positive for some organism and 126 sets were H. cinaedi positive. The time required for blood cultures to become positive for H. cinaedi was ≤5 days in 69 sets (55%) and >5 days in 57 sets (45%). Most patients had an underlying disease, including chronic kidney disease (21 cases), solid tumor (19 cases), hematological malignancy (13 cases), diabetes mellitus (8 cases), chronic liver disease (6 cases), and postorthopedic surgery (3 cases). Only 1 patient had no apparent underlying disease. The clinical symptoms included cellulitis in 24 cases, colitis in 7 cases, and fever only in 27 cases, including 7 cases of febrile neutropenia. The 30-day mortality rate of H. cinaedi bacteremia was 6.3%. In conclusion, most cases of H. cinaedi bacteremia occurred in immunocompromised patients. We might have overlooked nearly half of the H. cinaedi bacteremia cases if the duration of monitored blood culture samples had been within 5 days. Therefore, when clinicians suspect H. cinaedi bacteremia, the observation period for blood cultures should be extended.

  7. Arctic underwater noise transients from sea ice deformation: Characteristics, annual time series, and forcing in Beaufort Sea.

    PubMed

    Kinda, G Bazile; Simard, Yvan; Gervaise, Cédric; Mars, Jérôme I; Fortier, Louis

    2015-10-01

    A 13-month time series of Arctic Ocean noise from the marginal ice zone of the Eastern Beaufort Sea is analyzed to detect under-ice acoustic transients isolated from ambient noise with a dedicated algorithm. Noise transients due to ice cracking, fracturing, shearing, and ridging are sorted out into three categories: broadband impulses, frequency modulated (FM) tones, and high-frequency broadband noise. Their temporal and acoustic characteristics over the 8-month ice covered period, from November 2005 to mid-June 2006, are presented and their generation mechanisms are discussed. Correlations analyses showed that the occurrence of these ice transients responded to large-scale ice motion and deformation rates forced by meteorological events, often leading to opening of large-scale leads at main discontinuities in the ice cover. Such a sequence, resulting in the opening of a large lead, hundreds by tens of kilometers in size, along the margin of landfast ice and multiyear ice plume in the Beaufort-Chukchi seas is detailed. These ice transients largely contribute to the soundscape properties of the Arctic Ocean, for both its ambient and total noise components. Some FM tonal transients can be confounded with marine mammal songs, especially when they are repeated, with periods similar to wind generated waves.

  8. Biomass characteristics and simultaneous nitrification-denitrification under long sludge retention time in an integrated reactor treating rural domestic sewage.

    PubMed

    Gong, Lingxiao; Jun, Li; Yang, Qing; Wang, Shuying; Ma, Bin; Peng, Yongzhen

    2012-09-01

    In this work, a novel integrated reactor incorporating anoxic fixed bed biofilm reactor (FBBR), oxic moving bed biofilm reactor (MBBR) and settler sequentially was proposed for nitrogen removal from rural domestic sewage. For purposes of achieving high efficiency, low costs and easy maintenance, biomass characteristics and simultaneous nitrification-denitrification (SND) were investigated under long sludge retention time during a 149-day period. The results showed that enhanced SND with proportions of 37.7-42.2% tapped the reactor potentials of efficiency and economy both, despite of C/N ratio of 2.5-4.0 in influent. TN was removed averagely by 69.3% at least, even under internal recycling ratio of 200% and less proportions of biomass assimilation (<3%). Consequently, lower internal recycle and intermittent wasted sludge discharge were feasible to save costs, together with cancellations of sludge return and anoxic stir. Furthermore, biomass with low observed heterotrophic yields (0.053 ± 0.035 g VSS/g COD) and VSS/TSS ratio (<0.55) in MBBR, simplified wasted sludge disposal.

  9. Development of Real-Time Frame Selector 2 and the Characteristic Convective Structure in the Emerging Flux Region

    NASA Astrophysics Data System (ADS)

    Kozu, Hiromichi; Kitai, Reizaburo; Funakoshi, Yasuhiro

    2005-02-01

    A new image-grabbing system, Real-Time Frame Selector 2 (RTFS2), was developed and installed in the Domeless Solar Telescope at Hida Observatory. The purpose of this system is to acquire high-quality images in ground-based observations. We observed the emerging flux region NOAA 8582 in the G-band wavelengths from 20:59 UT to 23:32 UT on 1999 June 11 with RTFS2. Simultaneous Hα line center and wing wavelength observations with a Lyot filter system showed emerging flux loops and surge activities in this region. We applied a Local Correlation Tracking Method to the G-band data set in order to derive the horizontal convective structure in the upper convective zone. In addition to a meso-scale convective structure, we found divergent-flow structures under emerging flux loops, which were stable during the whole observation period, and located at the middle of the foot points of each flux loop. We suggest that the divergent-flow structure is a newly found characteristic of emerging flux regions.

  10. Spatial and temporal image characteristics of a real-time large area a-Se x-ray detector

    NASA Astrophysics Data System (ADS)

    Tousignant, Olivier; Demers, Yves; Laperriere, Luc; Mani, Habib; Gauthier, Philippe; Leboeuf, Jonathan

    2005-04-01

    Large area, real-time, amorphous selenium (a-Se) based Flat Panel Detectors (FPD) were recently equipped with low noise front end electronics. In full resolution, 14"x14" detectors (FPD14) and 9"x9" detectors (FPD9) show an electronic noise of 1400 electrons. To evaluate the positive impact of such low noise on image quality, a dedicated report on spatial characteristics (MTF, NPS and DQE) covering the low dose range from 0.6 μR to 12 μR per frame, will be presented in the first section of this paper. For one RQA5 beam quality, DQE corrected for lag extrapolated at zero spatial frequency was equal to 0.6 for quantum noise limited exposure and equal to 0.4 for 0.6 μR. Almost no difference was found between 1x1 and 2x2 resolution mode giving the opportunity to 1x1 fluoroscopy. Recent advances to reduce image temporal artifacts such as lag and ghost will make the second part of this paper. It is demonstrated that the most significant contribution to detector lag is coming from the PIN selenium structure. Above electric field of 10 V/μm charges release from traps following one x-ray exposure could not explain selenium lag. Active ghost correction based on deep trapped charge recombination was developed giving good preliminary results in showing no residual ghost for a high dose rate of 33 mR/min.

  11. Geostatistical characteristic of space-time variation in quality parameters in Klodzko water supply system (SW part of Poland)

    NASA Astrophysics Data System (ADS)

    Namysłowska-Wilczyńska, Barbara

    2015-04-01

    Selected results of research connected with the development of a (3D) geostatistical hydrogeochemical model of the Klodzko city area, dedicated to the spatial and time variation in the quality parameters in the Klodzko water supply system (SW part of Poland) will be presented. The research covers the period 2007 ÷ 2011. Spatial analyses of the variation in three different quality parameters, i.e. Fe iron [g/m3] content, Mn manganese [g/m3] content and NH4+ ammonium ion [g/m3] content, were carried out. Spatial and time variation in the parameters was analyzed on the basis of the data (2007 ÷ 2011). Thematic databases, containing original data on coordinates X, Y (latitude and longitude) and Z (time - years) and on regionalized variables, i.e. the water quality parameters in the Klodzko water supply system, were created. The input for the studies were the chemical determinations of the quality parameters of water samples taken in the Klodzko water supply system area in different periods of time. These data were subjected to spatial analyses using geostatistical methods. The geostatistical parameters of the assumed theoretical models of directional semivariograms functions of the studied water quality parameters, calculated for the time (years) interval, were used in the ordinary (block) kriging estimation. Generally, the behaviour of the quality parameters in the Klodzko water supply system has been found to vary in space and time. Thanks to the multidirectional spatial analyses some regularities in the variation in the water supply system in the Klodzko city area have been identified. In the considered time interval, the shapes of the directional Fe iron content semivariogram show a tendency to vary periodically. The courses of the directional semivariograms of Mn manganese content and NH4+ ammonium ion content show some tendencies towards directional variation over the passing years: distinctly expressed trends of variability for Mn content and stronger for NH4

  12. Demand characteristics, pre-test attitudes and time-on-task trends in the effects of chewing gum on attention and reported mood in healthy volunteers.

    PubMed

    Allen, A P; Smith, A P

    2012-10-01

    Previous research has indicated that chewing gum enhances reported alertness, but has variable effects on attention. Demand characteristics may explain these effects. The current study investigated the effects of gum and demand characteristics on attention and reported mood over time. Participants completed measures of mood and attention, with and without chewing gum. To manipulate demand characteristics, they were told that the hypothesised effect of gum was either positive or negative, or no hypothesis was mentioned. Attitudes towards gum were assessed pre- and post-manipulation. Gum increased reported alertness; this effect was only significant for positive and neutral demand characteristics. Vigilance accuracy was reduced for chewing gum, but only in the fourth minute of the task, and gum reduced focussed attention accuracy, but only for the first 64 trials. Demand characteristics did not moderate time-on-task effects. Gum improved selective attention. A positive effect on response organisation was observed; this was significant when demand characteristics and pre-test attitudes to gum were both negative. The results suggest that demand characteristics moderate effects on self-reported alertness and response organisation, but cannot explain time-on-task effects or variable main effects on other aspects of attention.

  13. Development of the Glenn-Heat-Transfer (Glenn-HT) Computer Code to Enable Time-Filtered Navier Stokes (TFNS) Simulations and Application to Film Cooling on a Flat Plate Through Long Cooling Tubes

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.; Shyam, Vikram; Rigby, David; Poinsatte, Phillip; Thurman, Douglas; Steinthorsson, Erlendur

    2014-01-01

    Computational fluid dynamics (CFD) analysis using Reynolds-averaged Navier-Stokes (RANS) formulation for turbomachinery-related flows has enabled improved engine component designs. RANS methodology has limitations that are related to its inability to accurately describe the spectrum of flow phenomena encountered in engines. Examples of flows that are difficult to compute accurately with RANS include phenomena such as laminar/turbulent transition, turbulent mixing due to mixing of streams, and separated flows. Large eddy simulation (LES) can improve accuracy but at a considerably higher cost. In recent years, hybrid schemes that take advantage of both unsteady RANS and LES have been proposed. This study investigated an alternative scheme, the time-filtered Navier-Stokes (TFNS) method applied to compressible flows. The method developed by Shih and Liu was implemented in the Glenn-Heat-Transfer (Glenn-HT) code and applied to film-cooling flows. In this report the method and its implementation is briefly described. The film effectiveness results obtained for film cooling from a row of 30deg holes with a pitch of 3.0 diameters emitting air at a nominal density ratio of unity and two blowing ratios of 0.5 and 1.0 are shown. Flow features under those conditions are also described.

  14. Development of the Glenn Heat-Transfer (Glenn-HT) Computer Code to Enable Time-Filtered Navier-Stokes (TFNS) Simulations and Application to Film Cooling on a Flat Plate Through Long Cooling Tubes

    NASA Technical Reports Server (NTRS)

    Ameri, Ali; Shyam, Vikram; Rigby, David; Poinsatte, Phillip; Thurman, Douglas; Steinthorsson, Erlendur

    2014-01-01

    Computational fluid dynamics (CFD) analysis using Reynolds-averaged Navier-Stokes (RANS) formulation for turbomachinery-related flows has enabled improved engine component designs. RANS methodology has limitations that are related to its inability to accurately describe the spectrum of flow phenomena encountered in engines. Examples of flows that are difficult to compute accurately with RANS include phenomena such as laminar/turbulent transition, turbulent mixing due to mixing of streams, and separated flows. Large eddy simulation (LES) can improve accuracy but at a considerably higher cost. In recent years, hybrid schemes that take advantage of both unsteady RANS and LES have been proposed. This study investigated an alternative scheme, the time-filtered Navier-Stokes (TFNS) method applied to compressible flows. The method developed by Shih and Liu was implemented in the Glenn-Heat-Transfer (Glenn-HT) code and applied to film-cooling flows. In this report the method and its implementation is briefly described. The film effectiveness results obtained for film cooling from a row of 30deg holes with a pitch of 3.0 diameters emitting air at a nominal density ratio of unity and two blowing ratios of 0.5 and 1.0 are shown. Flow features under those conditions are also described.

  15. Time dependent and temperature dependent properties of the forward voltage characteristic of InGaN high power LEDs

    NASA Astrophysics Data System (ADS)

    Fulmek, P. L.; Haumer, P.; Wenzl, F. P.; Nemitz, W.; Nicolics, J.

    2017-03-01

    Estimating the junction temperature and its dynamic behavior in dependence of various operating conditions is an important issue, since these properties influence the optical characteristics as well as the aging processes of a light-emitting diode (LED). Particularly for high-power LEDs and pulsed operation, the dynamic behavior and the resulting thermal cycles are of interest. The forward voltage method relies on the existence of a time-independent unique triple of forward-voltage, forward-current, and junction temperature. These three figures should as well uniquely define the optical output power and spectrum, as well as the loss power of the LED, which is responsible for an increase of the junction temperature. From transient FEM-simulations one may expect an increase of the temperature of the active semiconductor layer of some 1/10 K within the first 10 μs. Most of the well-established techniques for junction temperature measurement via forward voltage method evaluate the measurement data several dozens of microseconds after switching on or switching off and estimate the junction temperature by extrapolation towards the time of switching. In contrast, the authors developed a measurement procedure with the focus on the first microseconds after switching. Besides a fast data acquisition system, a precise control of the switching process is required, i.e. a precisely defined current pulse amplitude with fast rise-time and negligible transient by-effects. We start with a short description of the measurement setup and the newly developed control algorithm for the generation of short current pulses. The thermal characterization of the LED chip during the measurement procedures is accomplished by an IR thermography system and transient finite element simulations. The same experimental setup is used to investigate the optical properties of the LED in an Ulbricht-sphere. Our experiments are performed on InGaN LED chips mounted on an Al based insulated metal substrate

  16. Estimating the timing of long bone fractures: correlation between the postmortem interval, bone moisture content, and blunt force trauma fracture characteristics*.

    PubMed

    Wieberg, Danielle A M; Wescott, Daniel J

    2008-09-01

    There is very limited knowledge about how long perimortem fracture characteristics persist into the postmortem interval (PMI). Therefore, in this study, 60 porcine long bones were exposed to natural taphonomic conditions and fractured with a steel bone breaking apparatus every 28 days throughout a 141-day period. Differences between macroscopic blunt force trauma fracture characteristics (fracture angle, surface morphology, and outline) were examined to determine if they varied over time or in relationship to bone moisture content (ash weight) and overall assessment. There are significant relationships between (1) PMI and percent ash weight (%AW), fracture surface, and fracture angle and (2) %AW and fracture surface and fracture angle. Bone moisture content correlates significantly with fracture morphology and other characteristics commonly used by forensic anthropologists to determine the timing of traumatic injuries. However, fracture characteristics normally associated with perimortem trauma can persist long into the PMI.

  17. A simple method to estimate the time-dependent receiver operating characteristic curve and the area under the curve with right censored data.

    PubMed

    Li, Liang; Greene, Tom; Hu, Bo

    2016-11-27

    The time-dependent receiver operating characteristic curve is often used to study the diagnostic accuracy of a single continuous biomarker, measured at baseline, on the onset of a disease condition when the disease onset may occur at different times during the follow-up and hence may be right censored. Due to right censoring, the true disease onset status prior to the pre-specified time horizon may be unknown for some patients, which causes difficulty in calculating the time-dependent sensitivity and specificity. We propose to estimate the time-dependent sensitivity and specificity by weighting the censored data by the conditional probability of disease onset prior to the time horizon given the biomarker, the observed time to event, and the censoring indicator, with the weights calculated nonparametrically through a kernel regression on time to event. With this nonparametric weighting adjustment, we derive a novel, closed-form formula to calculate the area under the time-dependent receiver operating characteristic curve. We demonstrate through numerical study and theoretical arguments that the proposed method is insensitive to misspecification of the kernel bandwidth, produces unbiased and efficient estimators of time-dependent sensitivity and specificity, the area under the curve, and other estimands from the receiver operating characteristic curve, and outperforms several other published methods currently implemented in R packages.

  18. Noise characteristics in DORIS station positions time series derived from IGN-JPL, INASAN and CNES-CLS analysis centres

    NASA Astrophysics Data System (ADS)

    Khelifa, S.

    2014-12-01

    Using wavelet transform and Allan variance, we have analysed the solutions of weekly position residuals of 09 high latitude DORIS stations in STCD (STation Coordinate Difference) format provided from the three Analysis Centres : IGN-JPL (solution ign11wd01), INASAN (solution ina10wd01) and CNES-CLS (solution lca11wd02), in order to compare the spectral characteristics of their residual noise. The temporal correlations between the three solutions, two by two and station by station, for each component (North, East and Vertical) reveal a high correlation in the horizontal components (North and East). For the North component, the correlation average is about 0.88, 0.81 and 0.79 between, respectively, IGN-INA, IGN-LCA and INA-LCA solutions, then for the East component it is about 0.84, 0.82 and 0.76, respectively. However, the correlations for the Vertical component are moderate with an average of 0.64, 0.57 and 0.58 in, respectively, IGN-INA, IGN-LCA and INA-LCA solutions. After removing the trends and seasonal components from the analysed time series, the Allan variance analysis shows that the three solutions are dominated by a white noise in the all three components (North, East and Vertical). The wavelet transform analysis, using the VisuShrink method with soft thresholding, reveals that the noise level in the LCA solution is less important compared to IGN and INA solutions. Indeed, the standard deviation of the noise for the three components is in the range of 5-11, 5-12 and 4-9mm in the IGN, INA, and LCA solutions, respectively.

  19. Time 2 tlk 2nite: use of electronic media by adolescents during family meals and associations with demographic characteristics, family characteristics, and foods served.

    PubMed

    Fulkerson, Jayne A; Loth, Katie; Bruening, Meg; Berge, Jerica; Eisenberg, Marla E; Neumark-Sztainer, Dianne

    2014-07-01

    We examined the frequency of adolescents' use of electronic media (ie, television/movie watching, text messaging, talking on the telephone, listening to music with headphones, and playing with hand-held games) at family meals and examined associations with demographic characteristics, rules about media use, family characteristics, and the types of foods served at meals using an observational, cross-sectional design. Data were drawn from two coordinated, population-based studies of adolescents (Project Eating Among Teens 2010) and their parents (Project Families and Eating Among Teens). Surveys were completed during 2009-2010. Frequent television/movie watching during family meals by youth was reported by 25.5% of parents. Multivariate logistic regression analyses indicated significantly higher odds of mealtime media use (P<0.05) for girls and older teens. In addition, higher odds of mealtime media use (P<0.05) were also seen among those whose parents had low education levels or were black or Asian; having parental rules about media use significantly reduced these odds. Frequent mealtime media use was significantly associated with lower scores on family communication (P<0.05) and scores indicating less importance placed on mealtimes (P<0.001). Furthermore, frequent mealtime media use was associated with lower odds of serving green salad, fruit, vegetables, 100% juice, and milk at meals, whereas higher odds were seen for serving sugar-sweetened beverages (P<0.05). The ubiquitous use of mealtime media by adolescents and differences by sex, race/ethnicity, age, and parental rules suggest that supporting parents in their efforts to initiate and follow-through on setting mealtime media use rules may be an important public health strategy.

  20. On the output characteristics of a semiconductor optical amplifier driven by an ultrafast optical time division multiplexing pulse train

    NASA Astrophysics Data System (ADS)

    Zoiros, K. E.; Chasioti, R.; Koukourlis, C. S.; Houbavlis, T.

    2007-03-01

    A comprehensive theoretical analysis of a semiconductor optical amplifier (SOA) that is subject to an ultrafast optical time division multiplexing pulse stream is presented with the help of a simple but efficient model developed for this purpose. The model combines the necessary set of mathematical equations with the appropriate simplifying assumptions to describe in the time domain gain saturation and recovery for the case of multiple incoming pulses. In this manner, analytical expressions can be obtained for the power and chirp profile of the amplified pulses, essentially extending the work that has been performed for a single pulse only. This allows to identify the critical operational parameters and to investigate and evaluate their effect on these two output characteristics. The derived simulation curves are thoroughly studied to specify the limitations imposed on the SOA small signal gain and carrier lifetime as well as on the full-width at half-maximum (FWHM) and energy of the input pulses and, based on a series of logical arguments, to extract useful rules concerning their selection so as to achieve improved performance with respect to the practical applications of all-optical switching and pulse compression. The obtained results indicate that due to the continuous insertion of pulses, the requirements for the SOA small signal gain and the input pulse energy are stringent than those for the case of isolated pulse amplification. The combination of these two parameters determines also the regime in which the amplifier must be biased to operate in order to ensure distortionless pulse amplification and enhanced chirp for efficient pulse compression and it has been found that low saturation is necessary for the former case whilst heavy saturation for the latter. The scopes of the corresponding requirements for the carrier lifetime and the FWHM are also tight but to a less extent and can be simply satisfied with the available photonics technology. These results

  1. Relationships between functional genes in Lactobacillus delbrueckii ssp. bulgaricus isolates and phenotypic characteristics associated with fermentation time and flavor production in yogurt elucidated using multilocus sequence typing.

    PubMed

    Liu, Wenjun; Yu, Jie; Sun, Zhihong; Song, Yuqin; Wang, Xueni; Wang, Hongmei; Wuren, Tuoya; Zha, Musu; Menghe, Bilige; Heping, Zhang

    2016-01-01

    Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) is well known for its worldwide application in yogurt production. Flavor production and acid producing are considered as the most important characteristics for starter culture screening. To our knowledge this is the first study applying functional gene sequence multilocus sequence typing technology to predict the fermentation and flavor-producing characteristics of yogurt-producing bacteria. In the present study, phenotypic characteristics of 35 L. bulgaricus strains were quantified during the fermentation of milk to yogurt and during its subsequent storage; these included fermentation time, acidification rate, pH, titratable acidity, and flavor characteristics (acetaldehyde concentration). Furthermore, multilocus sequence typing analysis of 7 functional genes associated with fermentation time, acid production, and flavor formation was done to elucidate the phylogeny and genetic evolution of the same L. bulgaricus isolates. The results showed that strains significantly differed in fermentation time, acidification rate, and acetaldehyde production. Combining functional gene sequence analysis with phenotypic characteristics demonstrated that groups of strains established using genotype data were consistent with groups identified based on their phenotypic traits. This study has established an efficient and rapid molecular genotyping method to identify strains with good fermentation traits; this has the potential to replace time-consuming conventional methods based on direct measurement of phenotypic traits.

  2. Time Variability of Surface-Layer Characteristics over a Mountain Ridge in the Central Himalayas During the Spring Season

    NASA Astrophysics Data System (ADS)

    Solanki, Raman; Singh, Narendra; Kiran Kumar, N. V. P.; Rajeev, K.; Dhaka, S. K.

    2016-03-01

    We present the diurnal variations of surface-layer characteristics during spring (March-May 2013) observed near a mountain ridge at Nainital (29.4°N, 79.5°E, 1926 m above mean sea level), a hill station located in the southern part of the central Himalayas. During spring, this region generally witnesses fair-weather conditions and significant solar heating of the surface, providing favourable conditions for the systematic diurnal evolution of the atmospheric boundary layer. We mainly utilize the three-dimensional wind components and virtual temperature observed with sonic anemometers (sampling at 25 Hz) mounted at 12- and 27-m heights on a meteorological tower. Tilt corrections using the planar-fit method have been applied to convert the measurements to streamline-following coordinate system before estimating turbulence parameters. The airflow at this ridge site is quite different from slope flows. Notwithstanding the prevalence of strong large-scale north-westerly winds, the diurnal variation of the mountain circulation is clearly discernible with the increase of wind speed and a small but distinct change in wind direction during the afternoon period. Such an effect further modulates the surface-layer water vapour content, which increases during the daytime and results in the development of boundary-layer clouds in the evening. The sensible heat flux ( H) shows peak values around noon, with its magnitude increasing from March (222± 46 W m^{-2}) to May (353± 147 W m^{-2}). The diurnal variation of turbulent kinetic energy ( e) is insignificant during March while its mean value is enhanced by 30-50 % of the post-midnight value during the afternoon (1400-1600 IST), delayed by {≈ }2 h compared to the peak in H. This difference between the phase variations of incoming shortwave flux, H and e primarily arise due to the competing effects of turbulent eddies produced by thermals and wind shear, the latter increase significantly with time until nighttime during April

  3. BRIEF COMMUNICATIONS: Influence of the profile of the spectral line of vibrations of a medium on the time characteristics of stimulated scattering

    NASA Astrophysics Data System (ADS)

    Bel'dyugin, Igor'M.; Zolotarev, M. V.; Sviridov, K. A.

    1985-01-01

    A theoretical analysis is made of the problem of the time taken to establish steady-state lasing as a result of various types of stimulated scattering (Raman, Brillouin, and excited by heat evolution in a medium) and of the law governing amplification of Stokes waves after times much shorter than the relaxation time of vibrations of the medium for an arbitrary spectral line profile. It is shown that the characteristic times for the establishment of steady-state lasing in the case of stimulated scattering near the maximum of the gain profile are of the same type for different spectral lines profiles and have similar values.

  4. Time Series Analysis of Sexual Assault Case Characteristics and the 2007–2008 Period of Post-Election Violence in Kenya

    PubMed Central

    Anastario, Michael P.; Adhiambo Onyango, Monica; Nyanyuki, Joan; Naimer, Karen; Muthoga, Rachel; Sirkin, Susannah; Barrick, Kelle; van Hasselt, Martijn; Aruasa, Wilson; Kibet, Cynthia; Omollo, Grace

    2014-01-01

    Background Following the declaration that President Mwai Kibaki was the winner of the Kenyan presidential election held on December 27, 2007, a period of post-election violence (PEV) took place. In this study, we aimed to identify whether the period of PEV in Kenya was associated with systematic changes in sexual assault case characteristics. Methods and Findings Medical records of 1,615 patients diagnosed with sexual assault between 2007 and 2011 at healthcare facilities in Eldoret (n = 569), Naivasha (n = 534), and Nakuru (n = 512) were retrospectively reviewed to examine characteristics of sexual assault cases over time. Time series and linear regression were used to examine temporal variation in case characteristics relative to the period of post-election violence in Kenya. Key informant interviews with healthcare workers at the sites were employed to triangulate findings. The time series of sexual assault case characteristics at these facilities were examined, with a specific focus on the December 2007–February 2008 period of post-election violence. Prais-Winsten estimates indicated that the three-month period of post-election violence was associated with a 22 percentage-point increase in cases where survivors did not know the perpetrator, a 20 percentage-point increase in cases with more than one perpetrator, and a 4 percentage-point increase in cases that had evidence of abdominal injury. The post-election violence period was also associated with an 18 percentage-point increase in survivors waiting >1 month to report to a healthcare facility. Sensitivity analyses confirmed that these characteristics were specific to the post-election violence time period. Conclusion These results demonstrate systematic patterns in sexual assault characteristics during the PEV period in Kenya. PMID:25170917

  5. It Takes Two to Tango, Doesn't It? The Influence of Couple Characteristics on the Timing of the Birth of the First Child.

    ERIC Educational Resources Information Center

    Corijn, Martine

    1996-01-01

    The timing of the first childbirth is studied using information about characteristics of both partners. The context specificity of the determinants of childbearing is examined by comparing couples with and without cohabitation experience. The sociocultural specificity is studied using data from the Netherlands and Flanders. Discusses findings. (KW)

  6. Effects of Time-Specific F-strain Mycoplasma gallisepticum Inoculation Overlays on Prelay ts-11-strain M. gallisepticum Vaccination on Blood Characteristics of Commercial Laying Hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two trials were conducted to determine the effects of a prelay ts-11-strain Mycoplasma gallisepticum (ts-11MG) vaccination alone or in combination with subsequent time specific F-strain M. gallisepticum (FMG) inoculations on the blood characteristics of commercial laying hens. The following 4 treat...

  7. Influencing Work-Related Learning: The Role of Job Characteristics and Self-Directed Learning Orientation in Part-Time Vocational Education

    ERIC Educational Resources Information Center

    Gijbels, David; Raemdonck, Isabel; Vervecken, Dries

    2010-01-01

    Based on the Demand-Control-Support (DCS) model, the present paper aims to investigate the influence of job characteristics such as job demands, job control, social support at work and self-directed learning orientation on the work-related learning behaviour of workers. The present study was conducted in a centre for part-time vocational education…

  8. Effects of transportation time, distance, stocking density, temperature and lairage time on incidences of pale soft exudative (PSE) and the physico-chemical characteristics of pork.

    PubMed

    Gajana, C S; Nkukwana, T T; Marume, U; Muchenje, V

    2013-11-01

    The study determined the effects of transportation time, distance, stocking density, temperature and lairage time on incidences of PSE and pork quality. Frequencies of PSE cases in stocking density categories within transport duration classes were determined. General linear models, regression and the principal component (PC) analysis were used to analyse the data. Highest incidences of PSE were recorded in autumn season while lowest incidences were recorded in the spring season. Transportation time and stocking density significantly affected pHu and ultimately PSE incidences although there were no interactive effects. Highest risks of PSE occurrence were observed with more space allowance. The highest incidences of PSE were observed for animals that had travelled for two hours while the PSE cases were lower in animals that travelled for longer times. Distance travelled and transportation time had significant effects (P<0.05) on thawing loss (TL) % of pork. No relationships were reported between the other pre-slaughter variables and pork quality attributes. With the exception of transportation time and distance travelled which had a positive relationship with TL%, variation in other pre-slaughter variables did not affect meat quality variables. The risks of PSE occurrence were dependent on stocking density and transportation time.

  9. The Influence of Student Demographics and Internal Characteristics on GPA, Persistence, and Academic Success of First-Time College Students

    ERIC Educational Resources Information Center

    Rodriguez, David B.

    2013-01-01

    Employing a non-experimental, ex-post facto design, the study examined the relationship of student demographic information and internal characteristics identified from the Learning and Study Strategies Inventory (LASSI) to student persistence, grade point average, and academic success. Cognitive Learning Theory (CLT), which focuses on the internal…

  10. Three list scheduling temporal partitioning algorithm of time space characteristic analysis and compare for dynamic reconfigurable computing

    NASA Astrophysics Data System (ADS)

    Chen, Naijin

    2013-03-01

    Level Based Partitioning (LBP) algorithm, Cluster Based Partitioning (CBP) algorithm and Enhance Static List (ESL) temporal partitioning algorithm based on adjacent matrix and adjacent table are designed and implemented in this paper. Also partitioning time and memory occupation based on three algorithms are compared. Experiment results show LBP partitioning algorithm possesses the least partitioning time and better parallel character, as far as memory occupation and partitioning time are concerned, algorithms based on adjacent table have less partitioning time and less space memory occupation.

  11. Correlation between bioaerosol microbial community characteristics and real-time measurable environmental items: A case study from KORUS-AQ pre-campaign in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Yoo, H.

    2015-12-01

    Due to global climate change, bioaerosols are more globally mixed with a more random manner. During a long-distance traveling dust event, the number of microbes significantly increases in bioaerosol, and the chance for bioaerosol to contain human pathogenic microorganisms may also increase. Recently, we have found that bioaerosol microbial community characteristics (copy number of total bacterial 16S rRNA genes, and population diversity and composition) are correlated with the quantitative detection of potential human pathogens. However, bioaerosol microbial community characteristics cannot be directly used in real-time monitoring because the DNA-based detection method requires at least couple days or a week to get reliable data. To circumvent this problem, a correlation of microbial community characteristics with real-time measurable environmental items (PM10, PM2.5, temperature, humidity, NOx, O3 etc.), if any, will be useful in frequent assessment of microbial risk from available real-time measured environmental data. In this work, we monitored bioaerosol microbial communities using a high-throughput DNA sequencing method (Mi-seq) during the KORUS-AQ (KoreaUS-Air Quality) pre-campaign (May to June, 2015) in Seoul, and investigated whether any correlation exists between the bioaerosol microbial community characteristics and the real-time measureable environmental items simultaneously attained during the pre-campaign period. At the pre-campaign site (Korea Institute of Science and Technology, Seoul), bioaerosol samples were collected using high volume air sampler, and their 16S rRNA gene based bacterial communities were analyzed by Miseq sequencing and bioinformatics. Simultaneously, atmosphere environmental items were monitored at the same site. Using Decision Tree, a non-linear multi-variant correlation was observed between the bioaerosol microbial community characteristics and the real-time measured atmosphere chemistry data, and a rule induction was developed

  12. Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe

    SciTech Connect

    Prevosto, L.; Mancinelli, B.; Kelly, H.

    2013-12-15

    This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core.

  13. Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe.

    PubMed

    Prevosto, L; Kelly, H; Mancinelli, B

    2013-12-01

    This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core.

  14. A National Picture of Part-Time Community College Faculty: Changing Trends in Demographics and Employment Characteristics

    ERIC Educational Resources Information Center

    Eagan, Kevin

    2007-01-01

    Although part-time faculty continue to dominate the instructional workforce of community colleges, relatively little is known about this diverse group of individuals. Part-timers are often portrayed as being "free-way flyers" who constantly seek full-time appointments in postsecondary education institutions. However, as this article demonstrates,…

  15. CHARACTERISTICS OF A FAST RISE TIME POWER SUPPLY FOR A PULSED PLASMA REACTOR FOR CHEMICAL VAPOR DESTRUCTION

    EPA Science Inventory

    Rotating spark gap devices for switching high-voltage direct current (dc) into a corona plasma reactor can achieve pulse rise times in the range of tens of nanoseconds. The fast rise times lead to vigorous plasma generation without sparking at instantaneous applied voltages highe...

  16. Characteristic-Galerkin and Galerkin/Least-Squares Space-Time Formulations for the Advection-Diffusion Equation with Time-Dependent Domains

    DTIC Science & Technology

    1992-01-01

    formulations for the advection- diffusion equation with time-dependent domains 0. Pironneau Universite Paris 6. Analyse Numerique . T 55-65/5. 4 place...solution of the advection- dissipation equation, Correspondence to: Dr. 0. Pironneau, Universit6 Paris 6, Analyse Numerique . T 55-65/5, 4 place...for Partial Differential Equations (Cambridize Univ. Press. Cambridge. 1989). 1121 TE. Tezduvar. .I. Behr and J. Liou. A new strategy for finite

  17. Effects of time after a second dose of immunization against GnRF (Improvest) independent of age at slaughter on commercial bacon slicing characteristics of immunologically castrated barrows.

    PubMed

    Tavárez, M A; Bohrer, B M; Herrick, R T; Mellencamp, M A; Matulis, R J; Ellis, M; Boler, D D; Dilger, A C

    2016-01-01

    The objective was to determine the effects of time after a second dose of anti-GnRF immunization on fresh belly characteristics and slicing yields of immunologically castrated (IC) barrows, physically castrated (PC) barrows and gilts slaughtered at 24 weeks of age. The second dose was staggered so that IC barrows were slaughtered at 4, 6, 8, or 10 weeks after the second dose. Fresh belly characteristics (N=141) were collected at slaughter and bacon was manufactured commercially. The main effects in the model were treatment and the random effects of block and block within replication. Thickness, flop distance, and lipid content increased (L; P<0.04) and iodine value tended to decrease (L; P=0.08) with time after the second dose in IC barrows. Slicing yields increased with time after the second dose (L; P<0.01), but were similar (P=0.11) among sexes. Increasing time of slaughter after second anti-GnRF dose improves fresh belly and bacon slicing characteristics in IC barrows.

  18. Relationship of mechanical characteristics and microstructural features to the time-dependent edge notch sensitivity of inconel 718 sheet

    NASA Technical Reports Server (NTRS)

    Wilson, D. J.

    1971-01-01

    Time-dependent notch sensitivity of Inconel 718 sheet was observed at 900 F to 1200 F (482 - 649 C). It occurred when edge-notched specimens were loaded below the yield strength and smooth specimen tests showed that small amounts of creep consumed large rupture life fractions. The severity of the notch sensitivity was reduced by decreasing the solution temperature, increasing the time and/or temperature of aging and increasing the test temperature to 1400 F (760 C). Elimination of time-dependent notch sensitivity correlated with a change in dislocation motion mechanism from shearing to by-passing precipitate particles.

  19. Engaging nursing home residents with dementia in activities: The effects of modeling, presentation order, time of day, and setting characteristics

    PubMed Central

    Cohen-Mansfield, Jiska; Thein, Khin; Dakheel-Ali, Maha; Marx, Marcia S.

    2011-01-01

    We examined the impact of setting characteristics and presentation effects on engagement with stimuli in a group of 193 nursing home residents with dementia (recruited from a total of seven nursing homes). Engagement was assessed through systematic observations using the Observational Measurement of Engagement (OME), and data pertaining to setting characteristics (background noise, light, and number of persons in proximity) were recorded via the environmental portion of the Agitation Behavior Mapping Inventory (ABMI; Cohen-Mansfield, Werner, & Marx, (1989). An observational study of agitation in agitated nursing home residents. International Psychogeriatrics, 1, 153–165). Results revealed that study participants were engaged more often with moderate levels of sound and in the presence of a small group of people (from four to nine people). As to the presentation effects, multiple presentations of the same stimulus were found to be appropriate for the severely impaired as well as the moderately cognitively impaired. Moreover, modeling of the appropriate behavior significantly increased engagement, with the severely cognitively impaired residents receiving the greatest benefit from modeling. These findings have direct implications for the way in which caregivers could structure the environment in the nursing home and how they could present stimuli to residents in order to optimize engagement in persons with dementia. PMID:20455123

  20. Real-time demonstration of the main characteristics of chaos in the motion of a real double pendulum

    NASA Astrophysics Data System (ADS)

    Vadai, Gergely; Gingl, Zoltán; Mellár, János

    2012-07-01

    Several studies came to the conclusion that chaotic phenomena are worth including in high school and undergraduate education. The double pendulum is one of the simplest systems that is chaotic; therefore, numerical simulations and theoretical studies of it have been given large publicity, and thanks to its spectacular motion, it has become one of the most famous demonstration tools of chaos, either through simulations or in real experiments. Although several attempts have been made to use the experiment in laboratory exercises, as the friction in the real experiment changes the nature of the motion and the values of characteristic parameters during the motion, examining the measured (dissipative) motion and comparing it with theoretical results raises several questions. In our review, we present a measurement system which is able to analyse these questions. The system, which consists of simple yet precise data acquisition electronics, easily attainable sensors, a Bluetooth module (to communicate with the PC) and open-source software, demonstrates on-line the main characteristics of chaos and the methods of its study and allows us to analyse the dissipative motion. Further information (including downloadable software) is provided on a dedicated page, http://www.inf.u-szeged.hu/noise/Research/DoublePendulum/.

  1. Turbulence characteristics of the noise producing region of an excited round jet. I - Time-average flow properties

    NASA Technical Reports Server (NTRS)

    Baltas, C.; Morris, P. J.

    1984-01-01

    Experiments were conducted to determine the mean turbulence characteristics of the noise-producing region of a 3 in. cold excited round jet. The jet was excited by plane acoustic waves with a high amplitude of excitation (2 percent of the jet dynamic head), and at a Strouhal number of 0.5. The flow Reynolds number was 280,000. The exit boundary layer was made turbulent by artificially tripping it with sandpaper strips. The data were obtained with single and X-hot-wires and processed in digital form. Mean and higher order statistics were also deduced. The results showed an increase in all three velocity components and stresses. However, most of the increase was noticed from the longitudinal component, while the changes in the radial velocity and the azimuthal component were much smaller. Substantial widening of the jet occurred, accompanied by a shortening of the potential core. Increased rates of production of energy close to the lip-line were a characteristic feature of the mixing region behavior.

  2. The effect of varying Co layer thickness on the time-temperature characteristics of Co/Sb semimetal embedded magnetic nanoparticles

    SciTech Connect

    Madden, M. R.; Alshammary, T.; Grove, B.; Phillips, J.; Reaz, K.; Hensley, S.; Kenning, G. G.

    2015-03-14

    We report the effect of varying cobalt thickness on the temperature-dependent time decay of the electrical resistance of Co/Sb multilayer samples. We find that for a given temperature, a five fold change in the Co thickness produces a 100 fold change in the characteristic decay time of the resistance. We find that the characteristic decay time, as a function of temperature, follows an Arrhenius law. During deposition, the Co evolves single domain magnetic nanoparticles, on the Sb, in either a Volmer-Weber or Stranski-Krastanov growth mode. This metastable state is then encased in 2.5 nm of Sb producing an embedded nanoparticle system. Scanning tunneling microscopy measurements taken before sample aging (annealing at a given temperature for enough time to complete the resistance decay) and after aging show that these nanoparticles undergo morphological transformations during aging. These transformations lead to well defined time dependent decays in both the magnetization and the electrical resistance, making this material an excellent candidate for an electronic time-temperature sensor.

  3. Mapping forest height, foliage height profiles and disturbance characteristics with time series of gap-filled Landsat and ALI imagery

    NASA Astrophysics Data System (ADS)

    Helmer, E.; Ruzycki, T. S.; Wunderle, J. M.; Kwit, C.; Ewert, D. N.; Voggesser, S. M.; Brandeis, T. J.

    2011-12-01

    We mapped tropical dry forest height (RMSE = 0.9 m, R2 = 0.84, range 0.6-7 m) and foliage height profiles with a time series of gap-filled Landsat and Advanced Land Imager (ALI) imagery for the island of Eleuthera, The Bahamas. We also mapped disturbance type and age with decision tree classification of the image time series. Having mapped these variables in the context of studies of wintering habitat of an endangered Nearctic-Neotropical migrant bird, the Kirtland's Warbler (Dendroica kirtlandii), we then illustrated relationships between forest vertical structure, disturbance type and counts of forage species important to the Kirtland's Warbler. The ALI imagery and the Landsat time series were both critical to the result for forest height, which the strong relationship of forest height with disturbance type and age facilitated. Also unique to this study was that seven of the eight image time steps were cloud-gap-filled images: mosaics of the clear parts of several cloudy scenes, in which cloud gaps in a reference scene for each time step are filled with image data from alternate scenes. We created each cloud-cleared image, including a virtually seamless ALI image mosaic, with regression tree normalization of the image data that filled cloud gaps. We also illustrated how viewing time series imagery as red-green-blue composites of tasseled cap wetness (RGB wetness composites) aids reference data collection for classifying tropical forest disturbance type and age.

  4. Effects of polychlorinated biphenyls and nutritional restriction on barbituate-induced sleeping times and selected blood characteristics in raccoons (Procyon lotor)

    SciTech Connect

    Montz, W.E.; Card, W.C.; Kirkpatrick, R.L.

    1982-05-01

    Hepatic microsomal enzyme activity was induced in wild-trapped raccoons (Procyon lotor) and selected blood characteristics were measured in an effort to detect responses due to PCB ingestion, nutritional restriction, and their interactions. Barbiturate-induced sleeping times were used as an index of hepatic microsomal activity because they have been used reliably by other workers. Blood characteristics examined in the study were nonesterified fatty acids (NEFA), cholesterol, and three ketone bodies (D-(-)-3-hydroxybutyrate, acetoacetate, and acetone). Results show a reduction in sleeping times, elevated NEFA and D-(-)-3-hydroxybutyrate concentrations, and lower cholesterol concentrations in PCB-treated groups. A highly significant interaction between PCB treatment and nutritional restriction was observed in acetoacetate concentrations. (JMT)

  5. Time-Series Analyses of Supergranule Characteristics Compared Between SDO/HMI, SOHO/MDI and Simulated Datasets

    NASA Astrophysics Data System (ADS)

    Williams, P. E.; Pesnell, W. D.

    2011-12-01

    Supergranulation is a well-observed solar phenomenon despite its underlying mechanisms remaining a mystery. Originally considered to arise due to convective motions, alternative mechanisms have been suggested such as the cumulative downdrafts of granules as well as displaying wave-like properties. Supergranule characteristics are well documented, however. Supergranule cells are approximately 35 Mm across, have lifetimes on the order of a day and have divergent horizontal velocities of around 300 m/s, a factor of 10 higher than their central radial components. While they have been observed using Doppler methods for more than half a century, their existence is also observed in other datasets such as magnetograms and Ca II K images. These datasets clearly show the influence of supergranulation on solar magnetism and how the local field is organized by the flows of supergranule cells. The Heliospheric and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO) continues to produce Doppler images enabling the continuation of supergranulation studies made with SOHO/MDI, but with superior temporal and spatial resolution. The size-distribution of divergent cellular flows observed on the photosphere now reaches down to granular scales, allowing contemporaneous comparisons between the two flow components. SOHO/MDI Doppler observations made during the minima of cycles 22/23 and 23/24 exhibit fluctuations of supergranule characteristics (global averages of the supergranule size, size-range and horizontal velocity) with periods of 3-5 days. Similar fluctuations have been observed in SDO/HMI Dopplergrams and the high correlation between co-temporal HMI & MDI suggest a solar origin. Their nature has been probed by invoking data simulations that produce realistic Dopplergrams based on MDI data.

  6. Time-Series Analyses of Supergranule Characteristics Compared Between SDO/HMI, SOHO/MDI and Simulated Datasets

    NASA Technical Reports Server (NTRS)

    Williams, Peter E.; Pesnell, William Dean

    2012-01-01

    Supergranulation is a well-observed solar phenomenon despite its underlying mechanisms remaining a mystery. Originally considered to arise due to convective motions, alternative mechanisms have been suggested such as the cumulative downdrafts of granules as well as displaying wave-like properties. Supergranule characteristics are well documented, however. Supergranule cells are approximately 35 Mm across, have lifetimes on the order of a day and have divergent horizontal velocities of around 300 mis, a factor of 10 higher than their central radial components. While they have been observed using Doppler methods for more than half a century, their existence is also observed in other datasets such as magneto grams and Ca II K images. These datasets clearly show the influence of supergranulation on solar magnetism and how the local field is organized by the flows of supergranule cells. The Heliospheric and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO) continues to produce Doppler images enabling the continuation of supergranulation studies made with SOHO/MDI, but with superior temporal and spatial resolution. The size-distribution of divergent cellular flows observed on the photosphere now reaches down to granular scales, allowing contemporaneous comparisons between the two flow components. SOHO/MDI Doppler observations made during the minima of cycles 22/23 and 23/24 exhibit fluctuations of supergranule characteristics (global averages of the supergranule size, size-range and horizontal velocity) with periods of 3-5 days. Similar fluctuations have been observed in SDO/HMI Dopplergrams and the high correlation between co-temporal HMI & MOl suggest a solar origin. Their nature has been probed by invoking data simulations that produce realistic Dopplergrams based on MOl data.

  7. Investigation of Thermal Conductivity and Heat Characteristics of Oil Sands Using Ultrasound Irradiation for Shortening the Preheating Time

    NASA Astrophysics Data System (ADS)

    Kamagata, Shingo; Kawamura, Youhei; Okawa, Hirokazu; Mizutani, Koichi

    2012-07-01

    Oil sands are attractive as an energy resource. Bitumen, which is found in oil sands, has high viscosity, so that it does not flow. Most oil sands are underground and are developed with a method called steam-assisted gravity drainage (SAGD). Hot steam is injected underground to fluidize bitumen and promote its recovery. However, the preheating time is too long. One way of reducing running costs is by shortening the preheating time. Previous studies have found that bitumen can be extracted from oil sands efficiently by applying ultrasonic irradiation, but SAGD was not applied directly in these cases. Thus, the purpose of this study is to apply ultrasonic irradiation to SAGD, thereby shortening the preheating time of oil sands. As a model experiment for SAGD, heat transfer experiments in a sand layer made with Toyoura sand and silicone oil were conducted and the thermal effect with ultrasound was investigated.

  8. Characteristics of THz carrier dynamics in GaN thin film and ZnO nanowires by temperature dependent terahertz time domain spectroscopy measurement

    NASA Astrophysics Data System (ADS)

    Balci, Soner; Baughman, William; Wilbert, David S.; Shen, Gang; Kung, Patrick; Kim, Seongsin Margaret

    2012-12-01

    We present a comprehensive study of the characteristics of carrier dynamics using temperature dependent terahertz time domain spectroscopy. By utilizing this technique in combination with numerical calculations, the complex refractive index, dielectric function, and conductivity of n-GaN, undoped ZnO NWs, and Al-doped ZnO NWs were obtained. The unique temperature dependent behaviors of major material parameters were studied at THz frequencies, including plasma frequency, relaxation time, carrier concentration and mobility. Frequency and temperature dependent carrier dynamics were subsequently analyzed in these materials through the use of the Drude and the Drude-Smith models.

  9. Real-time analysis of endogenous protoporphyrin IX fluorescence from δ-aminolevulinic acid and its derivatives reveals distinct time- and dose-dependent characteristics in vitro

    NASA Astrophysics Data System (ADS)

    Kiesslich, Tobias; Helander, Linda; Illig, Romana; Oberdanner, Christian; Wagner, Andrej; Lettner, Herbert; Jakab, Martin; Plaetzer, Kristjan

    2014-08-01

    Photodynamic therapy (PDT) and photodiagnosis based on the intracellular production of the photosensitizer protoporphyrin IX (PPIX) by administration of its metabolic precursor δ-aminolevulinic acid (ALA) achieved their breakthrough upon the clinical approval of MAL (ALA methyl ester) and HAL (ALA hexyl ester). For newly developed ALA derivatives or application in new tumor types, in vitro determination of PPIX formation involves multiparametric experiments covering variable pro-drug concentrations, medium composition, time points of analysis, and cell type(s). This study uses a fluorescence microplate reader with a built-in temperature and atmosphere control to investigate the high-resolution long-term kinetics (72 h) of cellular PPIX fueled by administration of either ALA, MAL, or HAL for each 10 different concentrations. For simultaneous proliferation correction, A431 cells were stably transfected with green fluorescent protein. The results indicate that the peak PPIX level is a function of both, incubation concentration and period: maximal PPIX is generated with 1 to 2-mM ALA/MAL or 0.125-mM HAL; also, the PPIX peak shifts to longer incubation periods with increasing pro-drug concentrations. The results underline the need for detailed temporal analysis of PPIX formation to optimize ALA (derivative)-based PDT or photodiagnosis and highlight the value of environment-controlled microplate readers for automated in vitro analysis.

  10. Space-time clustering characteristics of dengue based on ecological, socio-economic and demographic factors in northern Sri Lanka.

    PubMed

    Anno, Sumiko; Imaoka, Keiji; Tadono, Takeo; Igarashi, Tamotsu; Sivaganesh, Subramaniam; Kannathasan, Selvam; Kumaran, Vaithehi; Surendran, Sinnathamby Noble

    2015-11-26

    The aim of the present study was to identify geographical areas and time periods of potential clusters of dengue cases based on ecological, socio-economic and demographic factors in northern Sri Lanka from January 2010 to December 2013. Remote sensing (RS) was used to develop an index comprising rainfall, humidity and temperature data. Remote sensing data gathered by the AVNIR-2 instrument onboard the ALOS satellite were used to detect urbanisation, and a digital land cover map was used to extract land cover information. Other data on relevant factors and dengue outbreaks were collected through institutions and extant databases. The analysed RS data and databases were integrated into a geographical information system (GIS) enabling space-time clustering analysis. Our results indicate that increases in the number of combinations of ecological, socio-economic and demographic factors that are present or above the average contribute to significantly high rates of space-time dengue clusters. The spatio-temporal association that consolidates the two kinds of associations into one can ensure a more stable model for forecasting. An integrated spatiotemporal prediction model at a smaller level using ecological, socioeconomic and demographic factors could lead to substantial improvements in dengue control and prevention by allocating the right resources to the appropriate places at the right time.

  11. Compliance to a Cell Phone-Based Ecological Momentary Assessment Study: The Effect of Time and Personality Characteristics

    ERIC Educational Resources Information Center

    Courvoisier, Delphine S.; Eid, Michael; Lischetzke, Tanja

    2012-01-01

    Ecological momentary assessment (EMA) is a method that is now widely used to study behavior and mood in the settings in which they naturally occur. It maximizes ecological validity and avoids the limitations of retrospective self-reports. Compliance patterns across time have not been studied. Consistent compliance patterns could lead to data not…

  12. Variations on a Theme: Characteristics of Out-of-School Time Science Programs Offered by Distinct Organization Types

    ERIC Educational Resources Information Center

    Laursen, Sandra L.; Thiry, Heather; Archie, Tim; Crane, Rebecca

    2013-01-01

    The out-of-school time (OST) domain offers a promising resource for enriching young people's experience of science, technology, and engineering. Belief is widespread that OST programs are ideal locations in which to learn science and that youth participation may increase access to science for underrepresented groups, such as girls or minorities,…

  13. The Effect of Loans on Time to Doctorate Degree: Differences by Race/Ethnicity, Field of Study, and Institutional Characteristics

    ERIC Educational Resources Information Center

    Kim, Dongbin; Otts, Cindy

    2010-01-01

    Much of the focus of research on the impact of financial aid (debt in particular) has focused on undergraduate students. It is equally important to understand the impact of financial aid on graduate students, particularly since graduate students incur much higher levels of debt due to their prolonged time in higher education and because the rate…

  14. Closed Loop Real-Time Evaluation of Missile Guidance and Control Components: Simulator Hardware/Software Characteristics and Use

    DTIC Science & Technology

    1974-08-01

    attached. The MIOP ( Multiplexer input/Output Processor) transfers data In parallel with CPU operation and occupies the CPU only during the time required to...D6 HH H D7 ocr -a Figure 2.14 Logic Board for External Clock Control 2-23 Comcor 500 Analog and logic patchboards of the Ci-500 computer contain

  15. Real-time simulation of jet engines with digital computer. 1: Fabrication and characteristics of the simulator

    NASA Technical Reports Server (NTRS)

    Nishio, K.; Sugiyama, N.; Koshinuma, T.; Hashimoto, T.; Ohata, T.; Ichikawa, H.

    1983-01-01

    The fabrication and performance of a real time jet engine simulator using a digital computer are discussed. The use of the simulator in developing the components and control system of a jet engine is described. Comparison of data from jet engine simulation tests with actual engine tests was conducted with good agreement.

  16. Spectral representation: a core aspect of modelling the response characteristics of time-domain EMI mine detectors

    NASA Astrophysics Data System (ADS)

    West, G. F.; Bailey, R. C.

    2006-05-01

    Most modern EMI mine detectors can detect the very small conductive and/or ferromagnetic parts of typical mines with relative ease. However, they also respond significantly to certain soils that contain lossy ferromagnetic minerals. In some special environments such as ocean beaches, conductivity of the host soil may also cause a response. Characterizing and modelling both the various target response mechanisms and the EMI detectors quantitatively would be relatively straightforward if it were not for the fact that most modern EMI detectors operate in time domain and use different current waveforms and time gates to observe response. Furthermore, much of the information about targets and interferences and even instrumental spectral limitations is observational rather than analytical data. In this paper, we put forward a spectral representation method that can be incorporated into both EMI data gathering and instrument modelling and which facilitates efficient quantitative simulation of arbitrary time- domain detection systems. The methodology and examples of its use are presented. Pure induction response from the ground is modelled with a sum-over-N-elements transfer function in which the kernel elements are single pole, pure damping responses which are log-spaced over the spectral range of interest. Instrument transfer functions can be described with a standard sparse pole and zero representation (located anywhere in the damped frequency half plane), if required. Model fitting techniques employing generalized inversion controls are used to go back and forth between frequency and time domain and the set of model parameters.

  17. Outside School Time: An Examination of Science Achievement and Non-Cognitive Characteristics of 15-Year Olds in Several Countries

    ERIC Educational Resources Information Center

    Suter, Larry E.

    2016-01-01

    Elementary and secondary students spend more hours outside of class than in formal school and thus have more time for interaction with everyday science. However, evidence from a large international survey, Program of International Student Assessment (PISA) (OECD 2012), found a negative relationship between number of hours attending after-school…

  18. Effects of microwave power and microwave irradiation time on pretreatment efficiency and characteristics of corn stover using combination of steam explosion and microwave irradiation (SE-MI) pretreatment.

    PubMed

    Pang, Feng; Xue, Shulin; Yu, Shengshuan; Zhang, Chao; Li, Bing; Kang, Yong

    2012-08-01

    The effects of microwave power and microwave irradiation time on pretreatment efficiency and characteristics of corn stover were investigated based on a new process named combination of steam explosion and microwave irradiation (SE-MI) pretreatment. Results showed that with microwave power and microwave irradiation time increasing, glucose and xylose that released into hydrolyzate, as well as enzymatic hydrolysis yields and sugar yields of glucose and xylose were all slightly increased after SE-MI pretreatment. The maximum sugar yield was 72.1 g per 100 g glucose and xylose in feedstock, achieved at 540 W microwave power and 5 min microwave irradiation time. XRD analysis showed that the crystallinity of biomass was 15.6-19.9% lower for SE-MI pretreatment with microwave effect than that without microwave effect. However, low microwave power and short microwave irradiation time were favorable for SE-MI pretreatment considering energy consumption.

  19. Second mode unstable disturbance measurement of hypersonic boundary layer on cone by wavelet transform

    NASA Astrophysics Data System (ADS)

    Han, Jian; Jiang, Nan; Tian, Yan

    2011-08-01

    Experimental investigation of hypersonic boundary layer instability on a cone is performed at Mach number 6 in a hypersonic wind tunnel. Time series signals of instantaneous fluctuating surface-thermal-flux are measured by Pt-thin-film thermocouple temperature sensors mounted at 28 stations on the cone surface in the streamwise direction to investigate the development of the unstable disturbance. Wavelet transform is employed as a mathematical tool to obtain the multi-scale characteristics of fluctuating surface-thermal-flux both in the temporal and spectrum space. The conditional sampling algorithm using wavelet coefficient as an index is put forward to extract the unstable disturbance waveform from the fluctuating surface-thermal-flux signals. The generic waveform for the second mode unstable disturbance is obtained by a phase-averaging technique. The development of the unstable disturbance in the streamwise direction is assessed both in the temporal and spectrum space. Our study shows that the local unstable disturbance detection method based on wavelet transformation offers an alternative powerful tool in studying the hypersonic unstable mode of laminar-turbulent transition. It is demonstrated that, at hypersonic speeds, the dominant flow instability is the second mode, which governs the course of laminar-turbulent transition of sharp cone boundary layer.

  20. The effects of Bombyx mori silk strain and extraction time on the molecular and biological characteristics of sericin.

    PubMed

    Siritientong, Tippawan; Bonani, Walter; Motta, Antonella; Migliaresi, Claudio; Aramwit, Pornanong

    2016-01-01

    Sericin was extracted from three strains of Thai Bombyx mori silk cocoons (white shell Chul1/1, greenish shell Chul3/2, and yellow shell Chul4/2) by a high-pressure and high-temperature technique. The characteristics of sericin extracted from different fractions (15, 45, and 60 min extraction process) were compared. No differences in amino acid composition were observed among the three fractions. For all silk strains, sericin extracted from a 15-min process presented the highest molecular weight. The biological potential of the different sericin samples as a bioadditive for 3T3 fibroblast cells was assessed. When comparing sericin extracted from three silk strains, sericin fractions extracted from Chul4/2 improved cell proliferation, while sericin from Chul 1/1 activated Type I collagen production to the highest extent. This study allows the natural variability of sericin obtained from different sources and extraction conditions to be addressed and provides clues for the selection of sericin sources.

  1. Multitalker Speech Perception with Ideal Time-Frequency Segregation: Effects of Voice Characteristics and Number of Talkers

    DTIC Science & Technology

    2009-03-23

    Science, The Ohio State University, Columbus, Ohio 43210 Received 11 December 2007; revised 6 March 2009; accepted 23 March 2009 When a target voice is...frequency regions of a multitalker mixture but eliminated all the time-frequency regions dominated by the maskers. The results show that target...masker similarity has a small but systematic impact on energetic masking, with roughly a 1 dB release from masking for same-sex maskers versus same-talker

  2. Structural and technological characteristics of starch isolated from sorghum as a function of drying temperature and storage time.

    PubMed

    Cruz, David Bandeira da; Silva, Wagner Schellin Vieira da; Santos, Ivonir Petrarca Dos; Zavareze, Elessandra da Rosa; Elias, Moacir Cardoso

    2015-11-20

    The quality of sorghum grains can vary according to the conditions of the drying temperature and storage time. The objective of this study was to evaluate the effects of the drying temperature and storage time of sorghum grain on the structure and technological properties of starch. The sorghum grains were dried at 45, 65, and 85°C and stored for six months. The grains were stored in an environment with a controlled temperature and humidity, and the starch from sorghum grains was isolated in initial time, after three and six months. The sorghum starches grains dried at 45 and 65°C present higher relative crystallinity than the starches of sorghum grains dried at 85°C in three months of storage. A reduction in the solubility of the starches of the sorghum grains dried at 85°C was observed when the grains were stored during six months. The breakdown and swelling power of the starches were reduced with the increase of the drying temperature.

  3. X-ray Variability Characteristics of the Narrow line SEYFERT 1 MKN 766 I: Energy Dependent Timing Properties

    NASA Technical Reports Server (NTRS)

    Markowitz, A.; Turner, T. J.; Papadakis, I.; Arevalo, P.; Reeves, J. N.; Miller, L.

    2007-01-01

    We present the energy-dependent power spectral density (PSD) and cross-spectral properties of Mkn 766 obtained from a six-revolution XMM-Newton observation in 2005. The resulting PSDs, which have highest temporal frequency resolution for an AGN PSD to date, show breaks which increase in temporal frequency as photon energy increases; break frequencies differ by an average of approx.0.4 in the log between the softest and hardest bands. The consistency of the 2001 and 2005 observations variability properties, namely PSD shapes and the linear rms-flux relation, suggests the 2005 observation is simply a low-flux extension of the 2001 observation. The coherence function is measured to be approx.0.6-0.9 at temporal frequencies below the PSD break, and is lower for relatively larger energy band separation; coherence also drops significantly towards zero above the PSD break frequency. Temporal frequency-dependent soft-to-hard time lags are detected in this object for the first time: lags increase towards longer time scales and as energy separation increases. Cross-spectral properties are the thus consistent with previous measurements for Mkn 766 (Vaughan & Fabian 2003) and other accreting black hole systems. The results are discussed in the context of several variability models, including those based on inwardly-propagating viscosity variations in the accretion disk.

  4. Circadian regulation of human sleep and age-related changes in its timing, consolidation and EEG characteristics

    NASA Technical Reports Server (NTRS)

    Dijk, D. J.; Duffy, J. F.

    1999-01-01

    The light-entrainable circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus regulates the timing and consolidation of sleep by generating a paradoxical rhythm of sleep propensity; the circadian drive for wakefulness peaks at the end of the day spent awake, ie close to the onset of melatonin secretion at 21.00-22.00 h and the circadian drive for sleep crests shortly before habitual waking-up time. With advancing age, ie after early adulthood, sleep consolidation declines, and time of awakening and the rhythms of body temperature, plasma melatonin and cortisol shift to an earlier clock hour. The variability of the phase relationship between the sleep-wake cycle and circadian rhythms increases, and in old age sleep is more susceptible to internal arousing stimuli associated with circadian misalignment. The propensity to awaken from sleep advances relative to the body temperature nadir in older people, a change that is opposite to the phase delay of awakening relative to internal circadian rhythms associated with morningness in young people. Age-related changes do not appear to be associated with a shortening of the circadian period or a reduction of the circadian drive for wake maintenance. These changes may be related to changes in the sleep process itself, such as reductions in slow-wave sleep and sleep spindles as well as a reduced strength of the circadian signal promoting sleep in the early morning hours. Putative mediators and modulators of circadian sleep regulation are discussed.

  5. Enhanced fluorescence and structural characteristics of carboxymethyl cellulose/Eu(III) nano-complex: Influence of reaction time.

    PubMed

    Ye, Jun; Wang, Ben; Xiong, Jian; Sun, Runcang

    2016-01-01

    CMC/Eu(III) nano-complexes were synthesized by reacting Eu(3+) with carboxymethyl cellulose (CMC). The SEM and EDS showed that particle size was less than 100nm and evenly distributed. FTIR and XPS indicated that the oxygen atoms in COO (-), OH, and COC were involved in the complexation with Eu(3+), yet, the O atoms were involved in different positions on anhydroglucose rings depending on reaction time. It was found that there were good energy matches between energy levels on ground state of CMC and (5)D0 Eu(III). Moreover, the intensities of (5)D0→(7)F2 of the nano-complexes were stronger than that of (5)D0→(7)F1, which indicated that the Eu(III) was not in the center of symmetry. The optimized reaction time was 35min, at this reaction time the smallest particle size and uniform distribution was obtained, the coordination structure was advantageous for the energy absorption transfer and emission.

  6. Characteristics of variations of climate change and atmospheric CO2 concentration at different time scales over the past 500 Ma

    NASA Astrophysics Data System (ADS)

    LIU, Z.; Huang, S. S. X. E. C.; Tang, X.

    2015-12-01

    It is generally believed that current global warming is due to the persistent rise of atmospheric greenhouse gas CO2. The consensus is based mostly on the observational data of past decades and the polar ice core records. To understand the relationship between climate change and atmospheric CO2, their behaviors over a longer interval at different time scales need to be appreciated. Here, we collect and analyze past 500 Ma records of atmospheric CO2 and temperature in six time periods, namely Phanerozoic, Cenozoic, middle Pleistocene, last deglaciation, past millennium, and recent decades. According to the carriers and time spans, we divide these records into three categories: 1.The millionaire and longer records from model calculation and paleosols/paleobotany proxies. Although the trends of both variables are generally consistent on this time scale, it is difficult to establish a clear causal relationship because of great uncertainties and low resolutions of both sets of data. 2.The orbital scale mainly from the polar ice core. High precise CO2 and temperature reconstructions allow for an examination of the possible role of atmospheric CO2 in the glacial-interglacial transformation. 3.The records at centennial and shorter time scales over the past millennium from ice, snow, and instrumental data. The past millennium records are most abundant and accurate, especially CO2 has been measured directly in recent decades. However, due to the difficulties in distinguishing the effect of CO2 from other factors, there are great uncertainties in the interpretation of climate change versus CO2. Overall, we come to the following conclusions:1.Paleoclimatic reconstructions show that both temperature and atmospheric CO2 have generally decreased over the past 500 Ma. However, there are no consistent sequential orders in the changes between these two variables. 2.The Earth's atmospheric CO2 has a drastic oscillation history. There were many high CO2 periods when the values were

  7. Effects of storage medium and UV photofunctionalization on time-related changes of titanium surface characteristics and biocompatibility.

    PubMed

    Shen, Jian-Wei; Chen, Yun; Yang, Guo-Li; Wang, Xiao-Xiang; He, Fu-Ming; Wang, Hui-Ming

    2016-07-01

    Storage in aqueous solution and ultraviolet (UV) photofunctionalization are two applicable methods to overcome the biological aging and increase the bioactivity of titanium. As information regarding the combined effects of storage medium and UV photofunctionalization has never been found in published literatures, this study focused on whether appropriate storage methods and UV photofunctionalization have synergistic effects on the biological properties of aged titanium surfaces. Titanium plates and discs were sandblasted and acid etched and then further prepared in five different modes as using different storage mediums (air or dH2 O) for 4 weeks and then with or without UV treatment. The surface characteristics were evaluated with scanning electron microscopy, contact angle measurements, and X-ray photoelectron spectroscopy. MC3T3-E1 cells were cultured on the surfaces, and cellular morphology, proliferation, alkaline phosphatase activity, and osteocalcin release were evaluated. The results showed that nanostructures were observed on water-stored titanium surfaces with a size of about 15 × 20 nm(2) . UV treatment was effective to remove the hydrocarbon contamination on titanium surfaces stored in either air or water. UV photofunctionalization further enhanced the already increased bioactivity of modSLA on initial cell attachment, proliferation, alkaline phosphatase activity, and osteocalcin release. Overall, UV photofunctionalization was effective in further enhancing the already increased bioactivity by using dH2 O as storage medium, and the effect of UV treatment was much more overwhelming than that of the storage medium. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 932-940, 2016.

  8. Characteristics of B2O3 and Fe added into BaFe12O19 permanent magnets prepared at different milling time and sintering temperature

    NASA Astrophysics Data System (ADS)

    Sebayang, Perdamean; Sari, Ayu Yuswita; Ginting, Delovita; Allan, Yola; Nasruddin M., N.; Sebayang, Kerista

    2016-02-01

    The objective of present work is to investigate the characteristic of BaFe12O19, B2O3-BaFe12O19 and Fe-BaFe12O19 magnets fabricated at different milling time and sintering temperature. The characteristic of perrmanen magnet BaFe12O19 with different content of B2O3 and Fe which was fabricated at different milling time and sintering temperature were investigated. The powder mixtures were prepared by dry and wet milling at various milling time. The powder were mixtured and prepared by dry and wet milling at various milling time. The mixture powder was then compacted by anisotropic with compressive pressure of 50 N/cm2. The green bodies were sinter at 1050, 1100, 1150 and 1200°C and hold for 1 h, separately. The density, magnetic flux density and B-H curve were measured by Archimedes principle, Gauss meter and Permagraph, respectively. The microstructure and phase composition characterization were performed by SEM and XRD. The results of this study are presented in this paper. It shows that addition of Fe (in wet milling) and B2O3 (in dry milling) respectively give a potential benefit to reduce the sintering temperature and improve the magnetic flux density of barium hexaferrite.

  9. Application of the Monte Carlo methods and variational procedure for optimizing time-of-flight neutron diffractometer characteristics

    NASA Astrophysics Data System (ADS)

    Khrushchinsky, A. A.; Kuten, S. A.; Viarenich, K. A.; Speransky, P. A.

    2016-05-01

    Based on variational calculus, a procedure for the optimal approximation of detector surface of the time-of-flight neutron diffractometer has been suggested. The exact solution for a point sample and zero thickness detector has been obtained. Using the shape of the detector surface, an optimized Monte Carlo simulation has been performed for the parameters of the spectrometer depending on the sample size and detector thickness, its azimuthal and Bragg's angular dimensions, and taking into account the neutron absorption in the sample and detector.

  10. Calibrating passive acoustic monitoring: correcting humpback whale call detections for site-specific and time-dependent environmental characteristics.

    PubMed

    Helble, Tyler A; D'Spain, Gerald L; Campbell, Greg S; Hildebrand, John A

    2013-11-01

    This paper demonstrates the importance of accounting for environmental effects on passive underwater acoustic monitoring results. The situation considered is the reduction in shipping off the California coast between 2008-2010 due to the recession and environmental legislation. The resulting variations in ocean noise change the probability of detecting marine mammal vocalizations. An acoustic model was used to calculate the time-varying probability of detecting humpback whale vocalizations under best-guess environmental conditions and varying noise. The uncorrected call counts suggest a diel pattern and an increase in calling over a two-year period; the corrected call counts show minimal evidence of these features.

  11. Effect of cationic surfactants on characteristics and colorimetric behavior of polydiacetylene/silica nanocomposite as time-temperature indicator

    NASA Astrophysics Data System (ADS)

    Nopwinyuwong, Atchareeya; Kitaoka, Takuya; Boonsupthip, Waraporn; Pechyen, Chiravoot; Suppakul, Panuwat

    2014-09-01

    Polydiacetylene (PDA)/silica nanocomposites were synthesized by self-assembly method using polymerizable amphiphilic diacetylene monomers, 10,12-pentacosadiynoic acid (PCDA). Addition of cationic surfactants (PDADMAC and CTAB) to PDA/SiO2 nanocomposites induced higher intermolecular force which affected their size, shape and color transition. Pure PDA, PDA/SiO2, PDA/SiO2/PDADMAC and PDA/SiO2/CTAB were investigated by particle size analysis, TEM, SEM, UV-vis spectroscopy and FT-IR. It was found that the PDA/SiO2 nanocomposites exhibited slightly larger particle sizes than those of other samples. The PDA/SiO2 nanocomposites with a core-shell structure were almost regarded as spherical-shaped particles. Cationic surfactants, especially CTAB, presumably affected the particle size and shape of PDA/SiO2 nanocomposites due to the disruption of hydrogen bonding between PDA head group and ammonium group. The colorimetric response of both PDA/SiO2/surfactant and surfactant-free PDA/SiO2 aqueous solutions directly changed in relation to time and temperature; thus they were expected to be applied as a new polymer-based time-temperature indicator (TTI).

  12. Storage capacity, detention time, and selected sediment deposition characteristics for Gull and Silver Lakes, Mono County, California

    USGS Publications Warehouse

    Blodgett, J.C.

    1996-01-01

    Bathymetric surveys made in September 1994 indicate the maximum storage capacity of Gull and Silver Lakes, California, is about 2,400 and 3,000 acre-feet, respectively. During March through October 1994, the lake level dropped 0.7 feet at both Gull Lake and Silver Lake. The associated change in storage was 60 acre-feet at Gull Lake and 80 acre-feet at Silver Lake. The flow detention time for average annual flow conditions at Gull Lake is about 2.5 years and for Silver Lake, the average detention time is about 19 days. Sediment deposition at the inlet to Silver Lake has been monitored since 1951 using aerial photography. During 1963 through 1994, the area of sediment deposition increased from 0.32 to about 2.4 acres. Analyses of these data indicate that the rate of deposition was lower during 1951-72 than the rate during 1973-94. Sediment deposition at the lake inlet is a continuing phenomenon.

  13. The Energy-Dependent X-Ray Timing Characteristics of the Narrow Line Seyfert 1 MKN 766

    NASA Technical Reports Server (NTRS)

    Markowitz, A.; Papadakis, I.; Arevalo, P.; Turner, T. J.; Miller, L.; Reeves, J. N.

    2007-01-01

    We present the energy-dependent power spectral density (PSD) and cross-spectral properties of Mkn 766, obtained from combining data obtained during an XMM-Newton observation spanning six revolutions in 2005 with data obtained from an XMM-Newton long-look in 2001. The PSD shapes and rms-flux relations are found to be consistent between the 2001 and 2005 observations, suggesting the 2005 observation is simply a low-flux extension of the 2001 observation and permitting us to combine the two data sets. The resulting PSD has the highest temporal frequency resolution for any AGN PSD measured to date. Applying a broken power-law model yields break frequencies which increase in temporal frequency with photon energy. Obtaining a good fit when assuming energy-independent break frequencies requires the presence of a Lorentzian at 4.6 +/- 0.4 x 10(exp -4)Hz whose strength increases with photon energy, a behavior seen in black hole X-ray binaries. The cross-spectral properties are measured; temporal frequency-dependent soft-to-hard time lags are detected in this object for the first time. Cross-spectral results are consistent with those for other accreting black hole systems. The results are discussed in the context of several variability models, including those based on inwardly-propagating viscosity variations in the accretion disk.

  14. Effects of cutting time, stump height, parent tree characteristics, and harvest variables on development of bigleaf maple sprout clumps

    USGS Publications Warehouse

    Tappeiner, J. C.; Zasada, J.; Maxwell, B.

    1996-01-01

    In order to determine the effects of stump height, year of cutting, parent-tree size, logging damage, and deer browsing on bigleaf maple (Acer macrophyllum) sprout clump development, maple trees were cut to two stump heights at three different times. Stump height had the greatest impact on sprout clump size. Two years after clearcutting, the sprout clump volume for short stumps was significantly less than that for tall stumps. The sprout clump volume, area, and number of sprouts were significantly less for trees cut 1 and 2 yr before harvest than for trees cut at harvest. Sprout clump size was positively correlated with parent tree stem diameter and stump volume, and negatively correlated with the percentage of bark removed during logging. Browsing had no significant impact on average clump size. Uncut trees produced sprout clumps at their base and epicormic branches along the length of their stems; thus their crown volume averaged four to five times that of cut trees. Cutting maple in clearcuts to low stumps may reduce maple competition with Douglas-fir regeneration and still maintain maple in the next stand.

  15. Characteristics and Function of AN Electron Attachment Spectrometer: Pulse Formation Time and Gain Effects in P-10 Gas

    NASA Astrophysics Data System (ADS)

    Orchard, Gloria M.; Waker, Anthony J.

    2014-02-01

    An Electron Attachment Spectrometer (EAS) has been designed to measure electron attachment in air and other gases. The aim of the EAS is to observe how parameters such as the electric field, reduced electric field and type of gas can influence electron attachment. The overall objective of this work is to investigate if the gas-gain of a proportional counter can be optimized by minimizing electron attachment with oxygen to improve the measurement of tritium-in-air. Current research interests include the measurement of the time between the generation of the electron-ion pairs and arrival of the electrons at the wire anode. Additionally, the study of the multiplication properties of the detector as a function of pulse formation time, P-10 gas flow rate and electric field will be presented. The EAS is a cylinder with a length of approximately 92 mm and diameter of 41 mm comprised of cylindrical hollow brass electrodes and Teflon spacers. A uniform electric field within the tube is applied and guides electrons and/or ions towards their respective electrodes. A proportional counter with a 50 μm diameter wire anode is used to detect the electrons and/or ions created by an 241Am source located at the opposite end.

  16. A SPITZER SURVEY OF PROTOPLANETARY DISK DUST IN THE YOUNG SERPENS CLOUD: HOW DO DUST CHARACTERISTICS EVOLVE WITH TIME?

    SciTech Connect

    Oliveira, Isa; Van Dishoeck, Ewine F.; Lahuis, Fred; Pontoppidan, Klaus M.; MerIn, Bruno; Geers, Vincent C.; Joergensen, Jes K.; Olofsson, Johan; Augereau, Jean-Charles; Brown, Joanna M.

    2010-05-01

    We present Spitzer InfraRed Spectrograph (IRS) mid-infrared (5-35 {mu}m) spectra of a complete flux-limited sample ({>=}3 mJy at 8 {mu}m) of young stellar object (YSO) candidates selected on the basis of their infrared colors in the Serpens Molecular Cloud. Spectra of 147 sources are presented and classified. Background stars (with slope consistent with a reddened stellar spectrum and silicate features in absorption), galaxies (with redshifted polycyclic aromatic hydrocarbon (PAH) features), and a planetary nebula (with high ionization lines) amount to 22% of contamination in this sample, leaving 115 true YSOs. Sources with rising spectra and ice absorption features, classified as embedded Stage I protostars, amount to 18% of the sample. The remaining 82% (94) of the disk sources are analyzed in terms of spectral energy distribution shapes, PAHs, and silicate features. The presence, strength, and shape of these silicate features are used to infer disk properties for these systems. About 8% of the disks have 30/13 {mu}m flux ratios consistent with cold disks with inner holes or gaps, and 3% of the disks show PAH emission. Comparison with models indicates that dust grains in the surface of these disks have sizes of at least a few {mu}m. The 20 {mu}m silicate feature is sometimes seen in the absence of the 10 {mu}m feature, which may be indicative of very small holes in these disks. No significant difference is found in the distribution of silicate feature shapes and strengths between sources in clusters and in the field. Moreover, the results in Serpens are compared with other well-studied samples: the c2d IRS sample distributed over five clouds and a large sample of disks in the Taurus star-forming region. The remarkably similar distributions of silicate feature characteristics in samples with different environment and median ages-if significant-imply that the dust population in the disk surface results from an equilibrium between dust growth and destructive

  17. Influence of multi-deposition multi-annealing on time-dependent dielectric breakdown characteristics of PMOS with high-k/metal gate last process

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Rong; Yang, Hong; Xu, Hao; Wang, Xiao-Lei; Luo, Wei-Chun; Qi, Lu-Wei; Zhang, Shu-Xiang; Wang, Wen-Wu; Yan, Jiang; Zhu, Hui-Long; Zhao, Chao; Chen, Da-Peng; Ye, Tian-Chun

    2015-11-01

    A multi-deposition multi-annealing technique (MDMA) is introduced into the process of high-k/metal gate MOSFET for the gate last process to effectively reduce the gate leakage and improve the device’s performance. In this paper, we systematically investigate the electrical parameters and the time-dependent dielectric breakdown (TDDB) characteristics of positive channel metal oxide semiconductor (PMOS) under different MDMA process conditions, including the deposition/annealing (D&A) cycles, the D&A time, and the total annealing time. The results show that the increases of the number of D&A cycles (from 1 to 2) and D&A time (from 15 s to 30 s) can contribute to the results that the gate leakage current decreases by about one order of magnitude and that the time to fail (TTF) at 63.2% increases by about several times. However, too many D&A cycles (such as 4 cycles) make the equivalent oxide thickness (EOT) increase by about 1 Å and the TTF of PMOS worsen. Moreover, different D&A times and numbers of D&A cycles induce different breakdown mechanisms. Project supported by the National High Technology Research and Development Program of China (Grant No. SS2015AA010601) and the National Natural Science Foundation of China (Grant Nos. 61176091 and 61306129).

  18. Imaging time-resolved fluorescence characteristics of organelle specific fluorophores and photosensitizers using ps pulsed diode lasers and TCSPC techniques

    NASA Astrophysics Data System (ADS)

    Scalfi-Happ, Claudia; Dolp, Frank; Forster, Florian; Rueck, Angelika

    2004-09-01

    A time-correlated single photon counting (TCSPC) module (SPC-730, Becker & Hickl, Germany) was connected to a laser scanning microscope (Zeiss, Germany) equipped with an ultrafast photomultiplier. Short pulse excitation was achieved with two laser diodes emitting at 398nm and 434nm with a pulse duration of 70ps and 60 ps (PicoQuant, Germany) to allow intracellular fluorescence lifetime imaging (FLIM). With this setup, fluorescence lifetime of the mitochondrial marker Rhodamine 123 could be studied in solution under the same instrumental conditions as used for fluorescence lifetime imaging of cell monolayers. With the same set of parameters, fluorescence lifetime of Rhodamine 123 was calculated with good reproducibility in mitochondria of living cells. We present here a comparison of different fitting routines, including a multiexponential fitting based on the method of Laplace transformation. Fluorescence lifetimes calculated with the multiexponential fitting routine proved to be particularly useful to study the distribution of 5-ALA metabolites in cell monolayers.

  19. Influence of reaction time and temperature on product formation and characteristics associated with the hydrothermal carbonization of cellulose.

    PubMed

    Lu, Xiaowei; Pellechia, Perry J; Flora, Joseph R V; Berge, Nicole D

    2013-06-01

    Studies have demonstrated that hydrothermal carbonization of biomass and waste streams results in the formation of beneficial materials/resources with minimal greenhouse gas production. Data necessary to understand how critical process conditions influence carbonization mechanisms, product formation, and associated environmental implications are currently lacking. The purpose of this work is to hydrothermally carbonize cellulose at different temperatures and to systematically sample over a 96-h period to determine how changes in reaction temperature influence product evolution. Understanding cellulose carbonization will provide insight to carbonization of cellulosic biomass and waste materials. Results from batch experiments indicate that the majority of cellulose conversion occurs between the first 0.5-4h, and faster conversion occurs at higher temperatures. Data collected over time suggest cellulose solubilization occurs prior to conversion. The composition of solids recovered after 96h is similar at all temperatures, consisting primarily of sp(2) carbons (furanic and aromatic groups) and alkyl groups.

  20. Egg laying characteristics, egg weight, embryo development, hatching weight and post-hatch growth in relation to oviposition time of broiler breeders.

    PubMed

    Akil, R; Zakaria, A H

    2015-05-01

    Two experiments were conducted to determine egg laying characteristics and the effects of oviposition time on egg weight, embryo development and post-hatch growth in broiler breeders. In experiment 1, eggs collected for 3 consecutive days on hourly basis between 06:30 and 17:30h were categorized to early, middle and late oviposition times in the clutch. In experiment 2, eggs were incubated to study embryo development, remaining albumen, liver weight, heart weight and the tibia length of embryos at 12, 14, 16 and 18 days of incubation as well as the body weight of hatchlings and chickens at 7, 21 and 42 days of age in relation to oviposition time. About 76% of nest eggs were laid from 06:30 to 11:30h. A similar pattern was observed in floor eggs. Egg weight decreased (P<0.01) with advanced position in the clutch. Generally, oviposition time had no effect on embryo growth parameters. At hatch, body weight of chicks derived from eggs of late oviposition times was less (P<0.01) than that of chicks from eggs produced earlier in the clutch. From 3-week-old onwards, chickens of early oviposition time sustained heavier (P<0.05) weight than chickens of middle oviposition time whereas chickens of late oviposition time obtained a middle weight. Differences in egg weights, body weight at hatch and post-hatch growth due to time of oviposition suggest that oviposition time together with incubation conditions should be considered for obtaining greater uniformity and growth of chickens.

  1. Learning new movement patterns: a study on good and poor writers comparing learning conditions emphasizing spatial, timing or abstract characteristics.

    PubMed

    Overvelde, Anneloes; Hulstijn, Wouter

    2011-08-01

    In the earliest stages of motor-skill learning cognitive, visuo-spatial and dynamic processes play an important role. Which of these should be addressed first when children need to learn a new complex movement sequence? This study compares three learning methods in a within-subject design by having 18 good and 18 poor 8-year-old writers master unfamiliar, letter-like patterns by (1) tracing a trajectory on a screen, (2) tracking a moving target (pursuit), and (3) performing the pattern using written explicit instructions. Following each 10-trial learning phase, the children completed a short test phase. Besides errors and kinematic data, Dynamic Time Warping (DTW) was used to calculate the deviation for each pattern from the ideal shape (DTW-distance). As predicted, the number of errors and DTW-distance were very low during the learning phase of the tracing and pursuit conditions and higher in the explicit condition. Conversely, in the test phase, tracing yielded the highest DTW-distance and the explicit condition the lowest DTW-distance and error percentages. The results were remarkably similar for the good and poor writers. The poor learning results of the tracing condition and the good results of the explicit condition have important implications for the teaching of handwriting and remedial therapy.

  2. Outside school time: an examination of science achievement and non-cognitive characteristics of 15-year olds in several countries

    NASA Astrophysics Data System (ADS)

    Suter, Larry E.

    2016-03-01

    Elementary and secondary students spend more hours outside of class than in formal school and thus have more time for interaction with everyday science. However, evidence from a large international survey, Program of International Student Assessment (PISA) (OECD 2012), found a negative relationship between number of hours attending after-school science and science assessment scores in many countries, raising questions about why. The secondary analysis of the 2006, 2009, and 2012 PISA surveys found that in most Western countries the longer students attended after-school science programs (in a typical week), the lower their PISA standardized science test score, but the higher their positive attitudes toward future science careers, interest in science, and self-confidence in science. Several potential hypotheses for this relationship are examined and rejected. Further analysis of a causal relationship between frequent attendance in after-school programs and student achievement and attitudes should clearly identify the content of the program so that the analysis could distinguish experiences closely related to regular school curricula from the informal science activities that are not. A new analysis also should include carefully designed longitudinal surveys to test the effectiveness of informal experiences on later life choices in career and study. Revision of a Paper prepared for AERA meetings in Chicago, 19 April 2015.

  3. Global Characteristics of the Correlation and Time Lag Between Solar and Ionospheric Parameters in the 27-day Period

    NASA Technical Reports Server (NTRS)

    Lee, Choon-Ki; Han, Shin-Chan; Dieter,Bilitza; Ki-Weon,Seo

    2012-01-01

    The 27-day variations of topside ionosphere are investigated using the in-situ electron density measurements from the CHAMP planar Langmuir probe and GRACE K-band ranging system. As the two satellite systems orbit at the altitudes of approx. 370 km and approx. 480 km, respectively, the satellite data sets are greatly valuable for examining the electron density variations in the vicinity of F2-peak. In a 27-day period, the electron density measurements from the satellites are in good agreements with the solar flux, except during the solar minimum period. The time delays are mostly 1-2 day and represent the hemispherical asymmetry. The globally-estimated spatial patterns of the correlation between solar flux and in-situ satellite measurements show poor correlations in the (magnetic) equatorial region, which are not found from the ground measurements of vertically-integrated electron content. We suggest that the most plausible cause for the poor correlation is the vertical movement of ionization due to atmospheric dynamic processes that is not controlled by the solar extreme ultraviolet radiation.

  4. Clinical characteristics of patients with type 2 diabetes mellitus at the time of insulin initiation: INSTIGATE observational study in Spain

    PubMed Central

    Dilla, Tatiana; Reviriego, Jesús; Castell, Conxa; Goday, Albert

    2009-01-01

    Little information is available on the management of patients with type 2 diabetes mellitus (DM2) in regular clinical practice, prior to and at the point of initiating treatment with insulin. The INSTIGATE study provides a description of the clinical profile of the patient with DM2 who begins treatment with insulin in both primary and secondary care. A total of 224 patients who had been diagnosed with DM2, were not responding to oral treatment, and began receiving insulin were included in the INSTIGATE study in Spain. Demographic data were collected, as well as data on macro- and microvascular complications of diabetes and comorbidities, past medical history of diabetes and oral treatment administered, the clinical severity of diabetes (HbA1c concentration) and insulin treatment initiated. Mean age of the sample was 65.4 years and 56.7% were men. There were 87% of patients who had a diagnosis of at least one significant comorbidity, notably hypertension and hyperlipidemia. The patient profile for metabolic syndrome was met by 75.1% of the patients. There was a higher incidence of macrovascular complications (38.4%) than microvascular complications (16.1%). Prior to insulin initiation, the most recent mean HbA1c was 9.2%. The majority of patients had been treated in the last 12 months with sulfonylureas and/or metformin (69.6 and 57.6%). The most common treatment prior to insulinization was the co-administration of two oral antidiabetics (OADs) (37.5%). Patients with DM2 observed in the study presented with elevated mean HbA1c and body mass index levels, comorbidities and complications related to diabetes at the time of insulin initiation. Changes and adjustments in treatment from diagnosis of diabetes occur when HbA1c levels are far above those recommended by the IDF (International Diabetes Federation), a factor which could be contributing to the development of both macrovascular and microvascular complications in the patient profile described in the study. PMID

  5. The effects of noradrenaline on the amplitude-time characteristics of multiquantum endplate currents and the kinetics of induced secretion of transmitter quanta.

    PubMed

    Bukharaeva, E A; Gainulov, R Kh; Nikol'skii, E E

    2002-01-01

    Experiments on frog neuromuscular junctions using a two-electrode membrane potential clamping method were used to study the effects of noradrenaline on the amplitude-time characteristics of multiquantum endplate current (EPC) parameters and the time course of secretion of transmitter quanta during the process of EPC generation. Noradrenaline (10 microM) induced significant increases in EPC amplitude (by 16%), with a decrease in the ratio of the duration of the leading front of the EPC to the duration of the leading front of the miniature endplate current (mEPC). Analysis of the time course of induced secretion, based on sequential subtraction of signals with displacement on the time scale, showed that noradrenaline induced synchronization of the process of secretion of quanta involved in generating multiquantum EPC, resulting in a 25% decrease in parameter P90, which characterizes the extent of synchronization of quantum release. The quantum composition of EPC, measured by dividing the area of induced and spontaneous signals and by analysis of the time course of the secretion of quanta, showed no changes in response to noradrenaline. Thus, in conditions in which responses to single stimuli applied to the motor nerve results in the release of several tens of quanta, noradrenaline can lead to increases in the amplitude of multiquantum EPC by increasing the level of synchronization of secretion of the transmitter quanta forming this signal.

  6. Effect of gamma irradiation and storage time on microbial growth and physicochemical characteristics of pumpkin (Cucurbita Moschata Duchesne ex Poiret) puree.

    PubMed

    Gliemmo, María F; Latorre, María E; Narvaiz, Patricia; Campos, Carmen A; Gerschenson, Lía N

    2014-01-01

    The effect of gamma irradiation (0-2 kGy) and storage time (0-28 days) on microbial growth and physicochemical characteristics of a packed pumpkin puree was studied. For that purpose, a factorial design was applied. The puree contained potassium sorbate, glucose and vanillin was stored at 25°C . Gamma irradiation diminished and storage time increased microbial growth. A synergistic effect between both variables on microbial growth was observed. Storage time decreased pH and color of purees. Sorbate content decreased with storage time and gamma irradiation. Mathematical models of microbial growth generated by the factorial design allowed estimating that a puree absorbing 1.63 kGy would have a shelf-life of 4 days. In order to improve this time, some changes in the applied hurdles were assayed. These included a thermal treatment before irradiation, a reduction of irradiation dose to 0.75 kGy and a decrease in storage temperature at 20°C . As a result, the shelf-life of purees increased to 28 days.

  7. Association of Environment and Policy Characteristics on Children’s Moderate-to-Vigorous Physical Activity and Time Spent Sedentary in Afterschool Programs

    PubMed Central

    Ajja, Rahma; Clennin, Morgan N.; Weaver, R. Glenn; Moore, Justin B.; Huberty, Jennifer L.; Ward, Dianne S.; Pate, Russell R.; Beets, Michael W.

    2014-01-01

    Background Afterschool programs (ASPs) are an important setting in which to promote children’s physical activity. This study examines the association of environmental and policy characteristics on the moderate-to-vigorous physical activity (MVPA) and sedentary behavior of children attending ASPs. Methods A total of 1,302 children attending 20 ASPs across South Carolina wore accelerometers (ActiGraph GT3X+) for up to 4 non-consecutive days. Policy-level characteristics were evaluated using the Healthy Afterschool Program Index-Physical Activity (HAPI-PA) scale. Physical activity space was measured using a measuring wheel (indoor, ft2) and GIS (outdoor, acres). The structure (free-play or organized) of activity opportunities, was evaluated via direct observation. Time spent in MVPA and sedentary, both indoors and outdoors, was estimated using accelerometry. Results For every 5000ft2 of utilized indoor activity space an additional 2.4 and 3.3 minutes/day of sedentary behavior was observed among boys and girls, respectively. A higher ratio of free-play to organized play was associated with higher indoor sedentary behavior among boys and girls (3.9 minutes/day and 10.0 minutes/day, respectively). For every one acre of outdoor activity space used, an additional 2.7 minutes/day of MVPA was observed for boys. A higher free-play to organized play ratio was associated with higher outdoor MVPA for boys and girls (4.4 and 3.4 minutes/day increase, respectively). Policy characteristics were unrelated to MVPA levels and time spent sedentary. Conclusion Findings indicate that policies and the size of activity space had limited influence on MVPA and sedentary behavior, suggesting that programmatic structure may be a more effective option to improve MVPA levels of children attending ASPs. PMID:25251100

  8. VIIRS S-NPP Nighttime DNB Spectral Response Function (SRF): The At-launch Characteristics and How the SRF Changes with Time Due to Tungsten Oxides Chromaticity

    NASA Astrophysics Data System (ADS)

    Guenther, B.; Lei, N.; Moeller, C.

    2015-12-01

    The VIIRS Day-Night Band (DNB) is designed with 3 gain stages: Low (LGS), Mid (MGS) and High (HGS) to span bright daytime to moonlit night earth scene signal levels. The published at-launch DNB relative spectral response (RSR) is based upon the LGS spectral measurements, since it was well measured in the pre-launch test program and the LGS can be calibrated by the on-board solar diffuser (MGS and HGS saturate on the SD). The LGS RSR however does not fully represent the spectral characteristics of nighttime DNB data from the MGS and HGS. Nighttime data users who apply the detailed DNB spectral characteristics in their analyses should use modulated RSR appropriate to the MGS and HGS observations. The RSR modulation is due to spectral darkening of the 4 mirrors of the S-NPP VIIRS telescope, which were contaminated with tungsten oxides in fabrication. These tungsten oxides are 'in family' with transition lenses on eyeglasses that darken when exposed to sunlight but do not recover when VIIRS goes into darkness because VIIRS in space is in a vacuum (transition lenses require atmospheric oxygen to recover). The on-going mirror darkening has caused a time-dependent shift in DNB RSR towards blue wavelengths. This presentation will provide access to the correct RSR to use for S-NPP DNB nighttime data over the mission time on-orbit. The changes in characteristics will be described in engineering terms to facilitate clear user understanding of how to handle RSR for nighttime observations over the mission lifetime.

  9. Chemical Characteristics of Particulate Matter from Vehicle emission using High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS)

    NASA Astrophysics Data System (ADS)

    Park, T.; Lee, T.; Kang, S.; Lee, J.; Kim, J.; Son, J.; Yoo, H. M.; Kim, K.; Park, G.

    2015-12-01

    Car emissions are major contributors of particulate matter (PM) in the urban environment and effects of air pollution, climate change, and human activities. By increasing of interest in research of car emission for assessment of the PM control, it became require to understand the chemical composition and characteristics of the car exhaust gases and particulate matter. To understand car emission characteristics of PM, we will study PM of car emissions for five driving modes (National Institute Environmental Research (NIER)-5, NIER-9, NIER-12, NIER-14) and three fixed speed driving modes (30km/h, 70km/h, 110km/h) using different fuel types (gasoline, diesel, and LPG) at Transportation Pollution Research Center (TPRC) of NIER in Incheon, South Korea. PM chemical composition of car emission was measured for concentrations of organics, sulfate, nitrate, ammonium, PAHs, oxidation states and size distribution using an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and engine exhaust particle sizer (EEPS) on real-time. In the study, organics concentration was dominated for all cases of driving modes and the concentration of organics was increased in 110km/h fixed speed mode for gasoline and diesel. The presentation will provide an overview of the chemical composition of PM in the car emissions.

  10. [Epidemiological characteristics of children aged 1-4 years without timely birth dose of hepatitis B vaccine vaccination in China, 2014].

    PubMed

    Wang, F Z; Zhang, G M; Shen, L P; Liu, J H; Zheng, H; Wang, F; Miao, N; Sun, X J; Liang, X F; Cui, F Q

    2017-01-10

    Objective: To evaluate the epidemiological characteristics of the children aged 1-4 years without timely birth dose of hepatitis B vaccine (HepB(1)) vaccination. Methods: Based on the data from 160 disease surveillance points in 31 provinces of China, two-stage cluster random sampling was used to select the target population aged 1-4 years. A standard questionnaire was used to collect the information about the birth date, gender, ethnic group, place of birth, HepB immunization history of the children selected. A blood sample (3 ml) was taken from each subject for HBsAg testing. SAS software (Version 9.4) was used in our study. We analyzed the age, gender, ethnic group, area specific distributions of the children aged 1-4 years without timely HepB(1) vaccination and the influencing factors, and the relationship between the HepB(1) vaccination time and HBsAg prevalence rate. Results: A total of 12 587 children aged 1-4 years were analyzed and the non-timely HepB(1) vaccination rate was 10.12%. The place of birth, ethnic group, urban/rural area, eastern/central/western area, age were the main influencing factor of the non-timely HepB(1) vaccination. The non-timely HepB(1) vaccination rate was higher in 3-4 years old children (11.13%) than in 1-2 years old children (8.97%), in rural area (12.05%) than in urban area (8.19%), in western area (13.41%) than in central area (9.27%) and eastern area (7.72%), in minority ethnic group (18.06%) than in Han ethnic group (8.77%) and in children born outside hospital (57.66%) than in children born in hospital (9.27%). The HBsAg prevalence rate among 1-4 years children was 0.31%. The HBsAg prevalence rate of the children with timely HepB(1) vaccination (0.25%) was lower than that of the children without timely HepB(1) vaccination (0.89%). Conclusions: In China, the HBsAg prevalence rate among 1-4 years children with HepB vaccination decreased to <0.5% and the timely HepB(1) vaccination rate reached to 90%. We should strengthen the

  11. Slaughter plant location, USDA quality grade, external fat thickness, and aging time effects on sensory characteristics of beef loin strip steak.

    PubMed

    Miller, M F; Kerth, C R; Wise, J W; Lansdell, J L; Stowell, J E; Ramsey, C B

    1997-03-01

    A boneless beef strip loin (IMPS #180) was fabricated from each of 320 carcasses to study the effects of slaughter plant location, quality grade, fat thickness, and aging time on beef tenderness and palatability. Carcasses were selected for fat thickness (< .5 cm or > or = .5 cm fat thickness) and USDA quality grade (Select or Low Choice) from two slaughter facilities (IBP, Inc., Garden City, KS or Excel Inc., Plainview, TX), and the strips were aged for either 7 or 14 d. Aging steaks 14 d improved all sensory traits and Warner-Bratzler shear (WBS) values regardless of all other main effects (P < .05). Steaks from Choice carcasses that were processed in Kansas had higher initial and sustained tenderness ratings than steaks from carcasses that were processed in Texas or Select steaks from Kansas after 7 d of aging (P < .05). However, aging for 14 d removed differences from all sensory characteristics of steaks from Kansas and Texas. All sensory scores for steaks from carcasses that graded Choice were higher than those from carcasses that graded Select (P < .05). The USDA quality grade did not affect WBS values, and fat thickness did not affect sensory characteristics or WBS values (P > .05). Therefore, aging beef strip loin steaks for 14 compared with 7 d improved sensory score and decreased WBS values, but fat thickness had no effect on the palatability of loin strip steaks processed under these conditions.

  12. Long-term timing and glitch characteristics of anomalous X-ray pulsar 1RXS J170849.0–400910

    SciTech Connect

    Muş, Sinem Şaşmaz; Göğüş, Ersin

    2013-12-01

    We present the results of our detailed timing studies of an anomalous X-ray pulsar, 1RXS J170849.0–400910, using Rossi X-ray Timing Explorer (RXTE) observations spanning over ∼6 yr from 2005 until the end of the RXTE mission. We constructed the long-term spin characteristics of the source and investigated the time and energy dependence of the pulse profile and pulsed count rates. We find that the pulse profile and pulsed count rates in the 2-10 keV band do not show any significant variations in ∼6 yr. 1RXS J170849.0–400910 has been the most frequently glitching anomalous X-ray pulsar: three spin-up glitches and three candidate glitches were observed prior to 2005. Our extensive search for glitches later in the timeline resulted in no unambiguous glitches, though we identified two glitch candidates (with Δν/ν ∼ 10{sup –6}) in two data gaps: a strong candidate around MJD 55532 and another one around MJD 54819, which is slightly less robust. We discuss our results in the context of pulsar glitch models and expectancy of glitches within the vortex unpinning model.

  13. Characteristic Time Scales of Transport Processes for Chemotactic Bacteria in Groundwater: Analysis of Pore-scale to Field-scale Experimental Data

    NASA Astrophysics Data System (ADS)

    Ford, R. M.

    2010-12-01

    Many processes contribute to the transport of microorganisms in groundwater environments. One process of interest is chemotaxis, whereby motile bacteria are able to detect and swim toward increasing concentrations of industrial hydrocarbons that they perceive as food sources. By enabling bacteria to migrate to the sources of pollutants that they degrade, chemotaxis has the potential to enhance bioremediation efforts, especially in less permeable zones where contamination may persist. To determine the field conditions under which chemotaxis might be exploited in a bioremediation scheme requires an understanding of the characteristic time scales in the system. We defined a dimensionless chemotaxis number that compares the time over which a bacterial population is exposed to a chemical gradient to the time required for a bacterial population to migrate a significant distance in response to a chemical gradient. The exposure time and the response time are dependent upon the experimental conditions and properties of the bacteria and chemical attractant. Experimental data was analyzed for a range of groundwater flow rates over a wide scope of experimental systems including a single-pore with NAPL source, a microfluidic channel with and without a porous matrix, a laboratory column, a bench-scale microcosm and a field-scale study. Chemical gradients were created transverse to the flow direction. Distributions of chemotactic and nonchemotactic bacteria were compared to determine the extent of migration due to chemotaxis. Under some conditions at higher flow rates, the effect of chemotaxis was diminished to the point of not being detected. The goal of the study was to determine a critical value for the dimensionless chemotaxis number (which is independent of scale) that can be used as a design criterion to ascertain a priori the conditions under which a chemotactic response will impact bacterial transport relative to other processes such as advection and dispersion.

  14. Characteristics and Time-Dependent Instability of Ga-Doped ZnO Thin Film Transistor Fabricated by Radio Frequency Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Huang, Hai-Qin; Sun, Jian; Liu, Feng-Juan; Zhao, Jian-Wei; Hu, Zuo-Fu; Li, Zhen-Jun; Zhang, Xi-Qing; Wang, Yong-Sheng

    2011-12-01

    We report on the fabrication and electrical characteristics of Ga-doped ZnO thin film transistors (TFTs). Low Ga-doped (0.7wt%) ZnO thin films were deposited on SiO2/p-Si substrates by rf magnetron sputtering. The GZO TFTs show a mobility of 1.76 cm2/V·s, an on/off ratio of 1.0 × 106, and a threshold voltage of 35 V. The time-dependent instability of the TFT is studied. The VTH shifts negatively. In addition, the device shows a decrease of the on/off ratio, mainly due to the increase of the off-current. The mechanisms of instability are discussed.

  15. Series resistance effect on time zero dielectrics breakdown characteristics of MOSCAP with ultra-thin EOT high-k/metal gate stacks

    NASA Astrophysics Data System (ADS)

    Hao, Xu; Hong, Yang; Yanrong, Wang; Wenwu, Wang; Guangxing, Wan; Shangqing, Ren; Weichun, Luo; Luwei, Qi; Chao, Zhao; Dapeng, Chen; Xinyu, Liu; Tianchun, Ye

    2016-05-01

    The time zero dielectric breakdown characteristics of MOSCAP with ultra-thin EOT high-k metal gate stacks are studied. The TZDB results show an abnormal area dependence due to the series resistance effect. The series resistance components extracted from the Fowler-Nordheim tunneling relation are attributed to the spreading resistance due to the asymmetry electrodes. Based on a series model to eliminate the series resistance effect, an area acceleration dependence is obtained by correcting the TZDB results. The area dependence follows Poisson area scaling rules, which indicates that the mechanism of TZDB is the same as TDDB and could be considered as a trap generation process. Project supported by the National High Technology Research and Development Program (863 Program) of China (No. SS2015AA010601), the National Natural Science Foundation of China (Nos. 61176091, 61306129), and the Opening Project of the Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences.

  16. Mechanical characteristics of ultra-long horizontal nanocantilevers grown by real-time feedback control on focused-ion-beam chemical vapour deposition

    NASA Astrophysics Data System (ADS)

    Guo, Dengji; Warisawa, Shin'ichi; Ishihara, Sunao; Kometani, Reo

    2015-12-01

    Focused-ion-beam chemical vapour deposition (FIB-CVD) has been repeatedly proved to be a useful tool for the growth of three-dimensional (3D) micro- and nano-structures. The strategy of real-time feedback control on FIB-CVD was previously proposed and experimentally demonstrated to be effective for growing ultra-long horizontal nanocantilevers. To fabricate various nanoelectromechanical systems that consist of such types of nanocantilever structures, the mechanical characteristics of ultra-long horizontal nanocantilevers should be investigated. In this study, nanocantilevers with an overhang length of up to 35 μm were grown by using a 30 kV Ga+ FIB, a beam current of 0.50 pA and phenanthrene (C14H10) as the gas source to deposit a diamond-like carbon structure. The Young’s modulus of each nanocantilever was measured by bending the nanocantilever with a nanopillar whose Young’s modulus was known. The average density of each nanocantilever was calculated from the Young’s modulus and the measured resonant frequency. We found that the mechanical characteristics of each nanocantilever depended on the length of the nanocantilever if the strategy of real-time feedback control was applied in fabrication. The Young’s moduli and the averaged densities of the nanocantilevers with a length of 11 to 34 μm were found to be 86 to 254 GPa and 1950 to 5750 kg m-3, respectively. With the increase of the overhang length, the Young’s modulus and the average density were found to gradually increase.

  17. In-silico experiments on characteristic time scale at a shear-free gas-liquid interface in fully developed turbulence

    NASA Astrophysics Data System (ADS)

    Nagaosa, Ryuichi; Handler, Robert A.

    2011-12-01

    The purpose of this study is to model scalar transfer mechanisms in a fully developed turbulence for accurate predictions of the turbulent scalar flux across a shear-free gas-liquid interface. The concept of the surface-renewal approximation (Dankwerts, 1951) is introduced in this study to establish the predictive models for the interfacial scalar flux. Turbulent flow realizations obtained by a direct numerical simulation technique are employed to prepare details of three-dimensional information on turbulence in the region very close to the interface. Two characteristic time scales at the interface have been examined for exact prediction of the scalar transfer flux. One is the time scale which is reciprocal of the root-mean-square surface divergence, Tγ = langleγγrangle-1/2, where γ is the surface divergence. The other time scale to be examined is TS = Λ/V, where Λ is the zero-correlation length of the surface divergence as the interfacial length scale, and V is the root-mean-square velocity fluctuation in the streamwise direction as the interfacial velocity scale. The results of this study suggests that Tγ is slightly unsatisfactory to correlate the turbulent scalar flux at the gas-liquid interface based on the surface-renewal approximation. It is also found that the proportionality constant appear to be 0.19, which is different with that observed in the laboratory experiments, 0.34 (Komori, Murakami, & Ueda, 1989). It is concluded that the time scale, Tγ, is considered a different kind of the time scale observed in the laboratory experiments. On the other hand, the present in-silico experiments indicate that Ts predicts the turbulent scalar flux based on the surface-renewal approximation in a satisfactory manner. It is also elucidated that the proportionality constant for Ts is approximately 0.36, which is very close to that found by the laboratory experiments. This fact shows that the time scale Ts appears to be essentially the same as the time scale the

  18. Time scale dependence of the center of pressure entropy: What characteristics of the neuromuscular postural control system influence stabilographic entropic half-life?

    PubMed

    Federolf, Peter; Zandiyeh, Payam; von Tscharner, Vinzenz

    2015-12-01

    The center of pressure (COP) movement in studies of postural control reveals a highly regular structure (low entropy) over short time periods and a highly irregular structure over large time scales (high entropy). Entropic half-life (EnHL) is a novel measure that quantifies the time over which short-term temporal correlations in a time series deteriorate to an uncorrelated, random structure. The current study suggested and tested three hypotheses about how characteristics of the neuromuscular postural control system may affect stabilometric EnHL: (H1) control system activity hypothesis: EnHL decreases with increased frequency of control system interventions adjusting COP motion; (H2) abundance of states hypothesis: EnHL decreases with increased number of mechanically equivalent states available to the postural system; and (H3) neurologic process hierarchy hypothesis: EnHL increases if postural control functions shift from the spinal level to the motor cortex. Thirty healthy participants performed quiet stance tests for 90 s in 18 different conditions: stance (bipedal, one-legged, and tandem); footwear (bare foot, regular sports shoe, and rocker sole shoes); and simultaneous cognitive task (two-back working memory task, no challenge). A four-way repeated-measures ANOVA revealed significant changes in EnHL for the different stance positions and for different movement directions (medio-lateral, anterior-posterior). These changes support H1 and H2. Significant differences were also found between rocker sole shoes and normal or barefoot standing, which supports H3. This study contributes to the understanding of how and why EnHL is a useful measure to monitor neuromuscular control of balance.

  19. [Effect of food deprivation on quantitative and time characteristics of feeding of goldfish Carassius auratus in norm and under action of adrenaline].

    PubMed

    Garina, D V

    2011-01-01

    There was studied effect of intraperitoneally administered adrenaline (0.14 mg/kg) on volume and time characteristics of feeding (duration of single, grouped, and total nutrition) of goldfish Carassius auratus (L.) previously maintained on normal and restricted (for 10 and 15 days) diet. The fish on restricted diet demonstrated the biphasic alimentary response to the adrenaline administration, similar with that in the normally fed fish: a decrease of volume, duration of the grouped and total feeding at the first phase of action of hormone and an increase--at the second phase; however, the value of the response at the first phase of the hormone action was lower, whereas at the second phase--higher than in the fish obtaining a sufficient amount of food prior to the experiment. Duration of the single feeding rose in fish of all groups including the control one, the maximum increase being observed in the goldfish submitted to food deprivation. The glycogen content in hepatopancreas of the normally fed goldfish exceeded by the end of the experiment 4.5-6 times that in the food-deprived ones. The obtained results confirm suggestion that a decrease of the level of reserve substances in the body leads to a decrease of the fish receptivity to the stress hormone--adrenaline and, hence, to a change of the value of its effects on the food-searching goldfish activity, with preservation of dynamics of the parameters.

  20. The Relationship Between Background Characteristics and Death Anxiety in Times of War: A Comparison Between Three Generations Arab and Jewish Families in Israel.

    PubMed

    Ron, Pnina

    2016-11-01

    (a) To compare the levels of death anxiety between the Jewish and Arab population in Israel after the Second Lebanon War and the Casting Lead Operation. (b) To compare the levels of death anxiety between three families' generations: elderly parents, their adult children and their adult grandchildren and (c) to learn about the relationship between background characteristics and death anxiety in times of war. The sample included 172 trios of elderly parents (ages 65 and up), their middle aged children (ages 41-64) and, their young adult children (ages 20-40) living at the northern and southern of Israel. Three quarters of the participants were Jews and the others were Arabs (including Muslims, Christians and Druze). Participants answered a self-report questioner. Death anxiety levels were measured by the Carmel and Mutran's instrument (1999). In general, the highest levels of death anxiety were found among the elderly parents (p < 0.01). Regarding the nationality and the gender variables, the highest levels of death anxiety were found among the adult Jewish daughters' group (p < 0.001). Nationality was found to be the most contributive variable for predicting death anxiety levels among the three generations; the sense of mastery was the second contributor, to predict death anxiety levels among the three generations' participants. Elderly population, Arab population and women, are at high risk to suffer from high levels of death anxiety in times of war in Israel. Special attention should be given to this population groups.

  1. Single molecule tracking of Ace1p in Saccharomyces cerevisiae defines a characteristic residence time for non-specific interactions of transcription factors with chromatin

    PubMed Central

    Ball, David A.; Mehta, Gunjan D.; Salomon-Kent, Ronit; Mazza, Davide; Morisaki, Tatsuya; Mueller, Florian; McNally, James G.; Karpova, Tatiana S.

    2016-01-01

    In vivo single molecule tracking has recently developed into a powerful technique for measuring and understanding the transient interactions of transcription factors (TF) with their chromatin response elements. However, this method still lacks a solid foundation for distinguishing between specific and non-specific interactions. To address this issue, we took advantage of the power of molecular genetics of yeast. Yeast TF Ace1p has only five specific sites in the genome and thus serves as a benchmark to distinguish specific from non-specific binding. Here, we show that the estimated residence time of the short-residence molecules is essentially the same for Hht1p, Ace1p and Hsf1p, equaling 0.12–0.32 s. These three DNA-binding proteins are very different in their structure, function and intracellular concentration. This suggests that (i) short-residence molecules are bound to DNA non-specifically, and (ii) that non-specific binding shares common characteristics between vastly different DNA-bound proteins and thus may have a common underlying mechanism. We develop new and robust procedure for evaluation of adverse effects of labeling, and new quantitative analysis procedures that significantly improve residence time measurements by accounting for fluorophore blinking. Our results provide a framework for the reliable performance and analysis of single molecule TF experiments in yeast. PMID:27566148

  2. Time trends in the prevalence and epidemiological characteristics of neural tube defects in Liaoning Province, China, 2006-2015: A population-based study.

    PubMed

    Zhang, Tie-Ning; Gong, Ting-Ting; Chen, Yan-Ling; Wu, Qi-Jun; Zhang, Yuan; Jiang, Cheng-Zhi; Li, Jing; Li, Li-Li; Zhou, Chen; Huang, Yan-Hong

    2017-02-03

    To evaluate the time trends in the prevalence of neural tube defects and all their subtypes as well as to identify the epidemiological characteristics of these malformations documented in the Liaoning Province of northeast China from 2006 to 2015. This was a population-based observational study using data from 3,248,954 live births as well as from 6217 cases of neural tube defects, 1,600 cases of anencephaly, 2,029 cases of spina bifida, 404 cases of encephalocele, and 3,008 cases of congenital hydrocephalus from 14 cities in Liaoning Province from 2006 to 2015. All analyses were conducted using SPSS software. During the observational period, the prevalence of neural tube defects, anencephaly, spina bifida, encephalocele, and congenital hydrocephalus was 19.1, 4.9, 6.2, 1.2, and 9.3 per 10,000 live births, respectively. Significantly decreasing trends were observed in the prevalence of all these malformations except for encephalocele. Notably, relatively higher prevalence rates were found in isolated compared with non-isolated malformations, with significant differences in selected characteristics (e.g., prognosis status, gestational age, and birth weight) between isolated and non-isolated cases of these malformations. The prevalence of neural tube defects showed a downward trend in Liaoning Province from 2006 to 2015. However, more attention should be focused on non-isolated cases in the future because of the severe clinical manifestations. Future prevention efforts should be strengthened to reduce the risk of these malformations, especially the non-isolated subtype, in areas with high prevalence.

  3. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): time-resolved fluorescence measurements and all-atom molecular dynamics simulations.

    PubMed

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-21

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH3CONH2) and urea (NH2CONH2) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH3CONH2 + (1 - f)NH2CONH2] have been studied in a temperature range of 328-353 K which is ∼120-145 K above the measured glass transition temperatures (∼207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (∼70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (α2) and new non-Gaussian (γ) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems.

  4. Use of Self-Matching to Control for Stable Patient Characteristics While Addressing Time-Varying Confounding on Treatment Effect: A Case Study of Older Intensive Care Patients.

    PubMed

    Han, Ling; Pisani, M A; Araujo, K L B; Allore, Heather G

    Exposure-crossover design offers a non-experimental option to control for stable baseline confounding through self-matching while examining causal effect of an exposure on an acute outcome. This study extends this approach to longitudinal data with repeated measures of exposure and outcome using data from a cohort of 340 older medical patients in an intensive care unit (ICU). The analytic sample included 92 patients who received ≥1 dose of haloperidol, an antipsychotic medication often used for patients with delirium. Exposure-crossover design was implemented by sampling the 3-day time segments prior (Induction) and posterior (Subsequent) to each treatment episode of receiving haloperidol. In the full cohort, there was a trend of increasing delirium severity scores (Mean±SD: 4.4±1.7) over the course of the ICU stay. After exposure-crossover sampling, the delirium severity score decreased from the Induction (4.9) to the Subsequent (4.1) intervals, with the treatment episode falling in-between (4.5). Based on a GEE Poisson model accounting for self-matching and within-subject correlation, the unadjusted mean delirium severity scores was -0.55 (95% CI: -1.10, -0.01) points lower for the Subsequent than the Induction intervals. The association diminished by 32% (-0.38, 95%CI: -0.99, 0.24) after adjusting only for ICU confounding, while being slightly increased by 7% (-0.60, 95%CI: -1.15, -0.04) when adjusting only for baseline characteristics. These results suggest that longitudinal exposure-crossover design is feasible and capable of partially removing stable baseline confounding through self-matching. Loss of power due to eliminating treatment-irrelevant person-time and uncertainty around allocating person-time to comparison intervals remain methodological challenges.

  5. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): Time-resolved fluorescence measurements and all-atom molecular dynamics simulations

    SciTech Connect

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-21

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH{sub 3}CONH{sub 2}) and urea (NH{sub 2}CONH{sub 2}) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH{sub 3}CONH{sub 2} + (1 − f)NH{sub 2}CONH{sub 2}] have been studied in a temperature range of 328-353 K which is ∼120-145 K above the measured glass transition temperatures (∼207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (∼70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (α{sub 2}) and new non-Gaussian (γ) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems.

  6. Physiological responses and time-motion characteristics of 4-a-side small-sided game in young soccer players: the influence of different team formation methods.

    PubMed

    Köklü, Yusuf; Ersöz, Gülfem; Alemdaroğlu, Utku; Aşç, Alper; Ozkan, Ali

    2012-11-01

    The purpose of this study was to examine the influence of different team formation methods on the physiological responses to and time-motion characteristics of 4-a-side small-sided games (SSG4) in young soccer players. Thirty-two young soccer players (age 16.2 ± 0.7 years; height 172.9 ± 6.1 cm; body mass 64.1 ± 7.7 kg) voluntarily participated in this study. Anthropometric measurements, technical tests, and maximum oxygen uptake (V[Combining Dot Above]O2max) tests were carried out on the players. The SSG4 teams were then created using 4 different methods: according to the coaches' subjective evaluation (CE), technical scores (TS), V[Combining Dot Above]O2max (AP), and V[Combining Dot Above]O2max multiplied by TSs (CG). The teams thus created played 4 bouts of SSG4 at 2-day intervals. During the SSG4, heart rate (HR) responses, distance covered, and time spent in HRmax zones were recorded. In addition, rating of perceived exertion (RPE) and blood lactate level (La) were determined at the end of the last bout of each SSG4. Percent of HRmax (%HRmax), La, and RPE responses during SSG4 were significantly higher for teams chosen according to AP and CG compared with that according to CE and TS (p < 0.05). In addition, teams chosen by AP and CG spent significantly more time in zone 4 (>90% HRmax ) and covered a greater distance in the high-intensity running zone (>18 km·h) than did teams formed according to TS. Moreover, AP teams covered significantly greater total distance than TS teams did (p < 0.05). In conclusion, to spend more time in both the high-intensity HR zone and the high-intensity running zone, the teams in SSG4 should be formed according to the players' V[Combining Dot Above]O2max values or the values calculated using both the V[Combining Dot Above]O2max and technique scores.

  7. Effect of chamber characteristics, loading and analysis time on motility and kinetic variables analysed with the CASA-mot system in goat sperm.

    PubMed

    Del Gallego, R; Sadeghi, S; Blasco, E; Soler, C; Yániz, J L; Silvestre, M A

    2017-02-01

    Several factors unrelated to the semen samples could be influencing in the sperm motility analysis. The aim of the present research was to study the effect of four chambers with different characteristics, namely; slide-coverslip, Spermtrack, ISAS D4C10, and ISAS D4C20 on the sperm motility. The filling procedure (drop or capillarity) and analysis time (0, 120 and 240s), depth of chamber (10 or 20μm) and field on motility variables were analysed by use of the CASA-mot system in goat sperm. Use of the drop-filling chambers resulted in greater values than capillarity-filling chambers for all sperm motility and kinetic variables, except for LIN (64.5% compared with 56.3% of motility for drop- and capillarity-filling chambers respectively, P<0.05). There were no significant differences in total sperm motility between different chamber depths, however, use of the 20μm-chambers resulted in greater sperm progressive motility rate, VSL and LIN, and less VCL and VAP than chambers with a lesser depth. There was less sperm motility and lesser values for kinetic variables as time that elapsed increased between sample loading and sperm evaluation. For sperm motility, use of droplet-loaded chambers resulted in similar values of MOT in all microscopic fields, but sperm motility assessed in capillarity-loaded chambers was less in the central fields than in the outermost microscopic fields. For goats, it is recommended that sperm motility be analysed using the CASA-mot system with a drop-loaded chamber within 2min after filling the chamber.

  8. Mapping crop based on phenological characteristics using time-series NDVI of operational land imager data in Tadla irrigated perimeter, Morocco

    NASA Astrophysics Data System (ADS)

    Ouzemou, Jamal-eddine; El Harti, Abderrazak; EL Moujahid, Ali; Bouch, Naima; El Ouazzani, Rabii; Lhissou, Rachid; Bachaoui, El Mostafa

    2015-10-01

    Morocco is a primarily arid to semi-arid country. These climatic conditions make irrigation an imperative and inevitable technique. Especially, agriculture has a paramount importance for the national economy. Retrieving of crops and their location as well as their spatial extent is useful information for agricultural planning and better management of irrigation water resource. Remote sensing technology was often used in management and agricultural research. Indeed, it's allows crops extraction and mapping based on phenological characteristics, as well as yield estimation. The study area of this work is the Tadla irrigated perimeter which is characterized by heterogeneous areas and extremely small size fields. Our principal objectives are: (1) the delimitation of the major crops for a good water management, (2) the insulation of sugar beet parcels for modeling its yields. To achieve the traced goals, we have used Landsat-8 OLI (Operational Land Imager) data pan-sharpened to 15 m. Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) classifications were applied to the Normalized Difference Vegetation Index (NDVI) time-series of 10 periods. Classifications were calculated for a site of more than 124000 ha. This site was divided into two parts: the first part for selecting, training datasets and the second one for validating the classification results. The SVM and SAM methods classified the principal crops with overall accuracies of 85.27% and 57.17% respectively, and kappa coefficient of 80% and 43% respectively. The study showed the potential of using time-series OLI NDVI data for mapping different crops in irrigated, heterogeneous and undersized parcels in arid and semi-arid environment.

  9. Long-term impact of anaerobic reaction time on the performance and granular characteristics of granular denitrifying biological phosphorus removal systems.

    PubMed

    Wang, Yayi; Guo, Gang; Wang, Hong; Stephenson, Tom; Guo, Jianhua; Ye, Liu

    2013-09-15

    Removal of nitrogen and phosphorus (P) from wastewater is successfully and widely practiced in systems employing both granular sludge technology and enhanced biological P removal (EBPR) processes; however, the key parameter, anaerobic reaction time (AnRT), has not been thoroughly investigated. Successful EBPR is highly dependent on an appropriate AnRT, which induces carbon and polyphosphate metabolism by phosphorus accumulating organisms (PAOs). Therefore, the long-term impact of AnRT on denitrifying P removal performance and granular characteristics was investigated in three identical granular sludge sequencing batch reactors with AnRTs of 90 (R1), 120 (R2) and 150 min (R3). The microbial community structures and anaerobic stoichiometric parameters related to various AnRTs were monitored over time. Free nitrite acid (FNA) accumulation (e.g., 0.0008-0.0016 mg HNO2-N/L) occurred frequently owing to incomplete denitrification in the adaptation period, especially in R3, which influenced the anaerobic/anoxic intracellular intermediate metabolites and activities of intracellular enzymes negatively, resulting in lower levels of poly-P and reduced activity of polyphosphate kinase. As a result, the Accumulibacter-PAOs population decreased from 51 ± 2.5% to 43 ± 2.1% when AnRT was extended from 90 to 150 min, leading to decreased denitrifying P removal performance. Additionally, frequent exposure of microorganisms to the FNA accumulation and anaerobic endogenous conditions in excess AnRT cases (e.g., 150 min) stimulated increased extracellular polymeric substances (EPS) production by microorganisms, resulting in enhanced granular formation and larger granules (size of 0.6-1.2 mm), but decreasing anaerobic PHA synthesis and glycogen hydrolysis. Phosphorus removal capacity was mediated to some extent by EPS adsorption in granular sludge systems that possessed more EPS, longer AnRT and relatively higher GAOs.

  10. Determination of time-of-travel, dispersion characteristics, and oxygen reaeration coefficients during low streamflows--Lower Tacony/Frankford Creek, Philadelphia, Pennsylvania

    USGS Publications Warehouse

    Senior, Lisa A.; Gyves, Matthew C.

    2010-01-01

    Time-of-travel, dispersion characteristics, and oxygen reaeration coefficients were determined by use of dye and gas tracing for a 2-mile reach of Tacony/Frankford Creek in Philadelphia, southeastern Pennsylvania. The reach frequently has concentrations of dissolved oxygen (DO) below the water-quality standard of 4 milligrams per liter during warm months. Several large combined sewer overflows (CSOs), including one of the largest in Philadelphia (former Wingohocking Creek), discharge to the study reach in this urbanized watershed, affecting water quality and the timing and magnitude of storm peaks. In addition, a dam that commonly results in backwater conditions and reduced natural reaeration is present a few hundred feet from the end of the study reach. Time-of-travel and reaeration data were collected under base-flow conditions in August and September 2009 for three sub-reaches from Roosevelt Boulevard (U.S. Route 1) to Castor Avenue. Determination of traveltimes to the centroid of the dye cloud were needed for calculation of the reaeration coefficients. Results of the dye study in Tacony/Frankford Creek indicate that traveltimes were affected by the presence of man-made structures, such as the large scour hole and pool developed at the outfall of the T14 CSO and the dam, both of which reduce stream velocities. Mean stream velocities during the dye-tracer tests ranged from a maximum of 0.44 to 0.04 foot per second through a large pool. The dispersion efficiency of the stream was determined from relations between normalized unit concentrations to time to peak for use in water-quality modeling. Oxygen reaeration coefficients determined by a constant rate-injection method using propane as the tracer gas were as low as 0.04 unit per hour in a long pool affected by backwater conditions behind a dam. The highest reaeration coefficient was 2.29 units per hour for a steep-gradient reach with multiple winding channels through gravel deposits, just downstream of a large

  11. Real-time electrocardiogram P-QRS-T detection-delineation algorithm based on quality-supported analysis of characteristic templates.

    PubMed

    Karimipour, Atiyeh; Homaeinezhad, Mohammad Reza

    2014-09-01

    The main objective of this study is to introduce a simple, low-latency, and accurate algorithm for real-time detection of P-QRS-T waves in the electrocardiogram (ECG) signal. In the proposed method, real-time signal preprocessing, which includes high frequency noise filtering and baseline wander reduction, is performed by applying discrete wavelet transform (DWT). A method based on signal first-order derivative and adaptive threshold adjustment is employed for real-time detection of the QRS complex. Moreover, detection and delineation of P- and T-waves are achieved by correlation analysis conducted between signal and their templates. Besides, signal quality is investigated online, and if the quality of the analysis window is unacceptable, then the algorithm will guess (estimate) the locations of P- and T-waves. The operating characteristics of the proposed algorithm are evaluated by its implementation to an artificially generated ECG signal whose quality is adjustable from the best (Quality, 100%) to the worst (Quality, ≤40%) cases based on the random-walk noise theory. The algorithm was applied to the MIT-BIH arrhythmia database, QT database, and Physionet/CinC challenge 2011competition database. The obtained results, which were based on the QT database, showed sensitivity and positive predictivity of Se=99.63% and P+=99.83%, Se=99.83% and P+=99.98%, and Se=99.74% and P+=99.89% for the detection of P-, QRS-, and T-waves, respectively, and the obtained results, which were based on the MIT-BIH arrhythmia database, showed Se=99.81% and P+=99.70% for the detection of the QRS complex. Moreover, it will be shown that the results of the proposed method are reliable for a minimum signal quality value of 70%. According to numerical assessments, 8-ms after the occurrence of R-wave, its location will be identified by the computer code of the proposed algorithm. This parameter is 198-ms and 177-ms for P- and T-waves, respectively.

  12. Dynamic characteristic mechanism of atrial septal defect using real-time three-dimensional echocardiography and evaluation of right ventricular functions.

    PubMed

    Sharen, Gao-Wa; Zhang, Jun; Qin, Chuan; Lv, Qing

    2017-02-01

    The dynamic characteristics of the area of the atrial septal defect (ASD) were evaluated using the technique of real-time three-dimensional echocardiography (RT 3DE), the potential factors responsible for the dynamic characteristics of the area of ASD were observed, and the overall and local volume and functions of the patients with ASD were measured. RT 3DE was performed on the 27 normal controls and 28 patients with ASD. Based on the three-dimensional data workstations, the area of ASD was measured at P wave vertex, R wave vertex, T wave starting point, and T wave terminal point and in the T-P section. The right atrial volume in the same time phase of the cardiac cycle and the motion displacement distance of the tricuspid annulus in the corresponding period were measured. The measured value of the area of ASD was analyzed. The changes in the right atrial volume and the motion displacement distance of the tricuspid annulus in the normal control group and the ASD group were compared. The right ventricular ejection fractions in the normal control group and the ASD group were compared using the RT 3DE long-axis eight-plane (LA 8-plane) method. Real-time three-dimensional volume imaging was performed in the normal control group and ASD group (n=30). The right ventricular inflow tract, outflow tract, cardiac apex muscular trabecula dilatation, end-systolic volume, overall dilatation, end-systolic volume, and appropriate local and overall ejection fractions in both two groups were measured with the four-dimensional right ventricular quantitative analysis method (4D RVQ) and compared. The overall right ventricular volume and the ejection fraction measured by the LA 8-plane method and 4D RVQ were subjected to a related analysis. Dynamic changes occurred to the area of ASD in the cardiac cycle. The rules for dynamic changes in the area of ASD and the rules for changes in the right atrial volume in the cardiac cycle were consistent. The maximum value of the changes in the

  13. A Nonlinear Theory for Predicting the Effects of Unsteady Laminar, Turbulent, or Transitional Boundary Layers on the Attenuation of Shock Waves in a Shock Tube with Experimental Comparison

    NASA Technical Reports Server (NTRS)

    Trimpi, Robert L.; Cohen, Nathaniel B.

    1961-01-01

    The linearized attenuation theory of NACA Technical Note 3375 is modified in the following manner: (a) an unsteady compressible local skin-friction coefficient is employed rather than the equivalent steady-flow incompressible coefficient; (b) a nonlinear approach is used to permit application of the theory to large attenuations; and (c) transition effects are considered. Curves are presented for predicting attenuation for a shock pressure ratio up to 20 and a range of shock-tube Reynolds numbers. Comparison of theory and experimental data for shock-wave strengths between 1.5 and 10 over a wide range of Reynolds numbers shows good agreement with the nonlinear theory evaluated for a transition Reynolds number of 2.5 X 10(exp 5).

  14. On the Evaluation of Axisymmetric Forebody Shapes for Delaying Laminar-Turbulent Transition. Part 1. Background and Analysis of the Problem.

    DTIC Science & Technology

    1977-08-01

    Farabee 1 1942 Geib , 2 ARL, Penn State Univ. 1 1942 Gordon 1 Dr . B. Parkin 1 1942 Granum 1 Dr . R. Arndt 1 1942 Lewis 1 1942 Mathews 2 Princeton...It has been brought to our attention by Dr . von KerczeK that 3>1 can occur on flat faced bodies of revolution downstream of the stagnation point. 7...stability. Much gratitude is expressed to Dr . John Niedzwecki for providing us with a ’ preliminarycopy of the derivation of the transformation

  15. Effect of the ripening time under vacuum and packaging film permeability on processing and quality characteristics of low-fat fermented sausages.

    PubMed

    Liaros, N G; Katsanidis, E; Bloukas, J G

    2009-12-01

    The effect of vacuum ripening of low-fat fermented sausages packaged in films with different permeabilities on their microbiological, physicochemical and sensorial characteristics was studied. High-fat control sausages were produced with 30% initial fat and low-fat sausages with 10% initial fat. The low-fat sausages were separated into: (a) non-packaged (control) and (b) packaged under vacuum on 7th, 12th and 17th day of processing, remaining under vacuum during the ripening period for 21, 16 and 11days, respectively, in three different oxygen (100, 38 and⩽5cm(3)/m(2)/24h/1atm) and water vapour (4.5, <2.5 and 1g/m(2)24h) permeability plastic bags. Vacuum packaging reduced (p<0.05) the weight loss, the hardness and extent of lipid oxidation in the sausages, increased (p<0.05) their lightness, but had no effect (p>0.05) on the redness, compared to the control sausages. Packaging low-fat fermented sausages under vacuum for the last 11days of ripening in packaging film with high permeability increased (p<0.05) the lactic acid bacteria count. The same product packaged in film with medium permeability had a higher (p<0.05) Micrococcaceae count and the same (p>0.05) hardness and overall acceptability as the high-fat control sausages. A ripening time of 11days and the medium packaging film permeability were the most appropriate conditions for the vacuum packaging of low-fat fermented sausages.

  16. Step-changes in the physical, chemical and biological characteristics of the Gulf of Maine, as documented by the GNATS time series

    USGS Publications Warehouse

    Balch, William M.; Drapeau, D.T.; Bowler, B.C.; Huntington, Thomas G.

    2012-01-01

    We identify step-changes in the physical, chemical and biological characteristics of the Gulf of Maine (GoM) using the Gulf of Maine North Atlantic Time Series (GNATS), a series of oceanographic measurements obtained between September 1998 and December 2010 along a transect in the GoM running from Portland, ME, to Yarmouth, NS. GNATS sampled a period of extremes in precipitation and river discharge (4 of the 8 wettest years of the last century occurred between 2005 and 2010). Coincident with increased precipitation, we observed the following shifts: (1) decreased salinity and density within the surface waters of the western GoM; (2) both reduced temperature and vertical temperature gradients in the upper 50 m; (3) increased colored dissolved organic matter (CDOM) concentrations and particle scattering in the western GoM; (4) increased concentrations of nitrate and phosphate across all but the eastern GoM; (5) increased silicate, particularly in the western GoM, with a sharp increase in the ratio of silicate to dissolved inorganic nitrogen; (6) sharply decreased carbon fixation by phytoplankton; (7) moderately decreased chlorophyll, particulate organic carbon (POC) and particulate inorganic carbon (PIC) in the central GoM and (8) decreased POC- and PIC-specific growth rates. Gulf-wide anomaly analyses suggest that (1) the surface density changes were predominantly driven by temperature, (2) dissolved nutrients, as well as POC/PON, varied in Redfield ratios and (3) anomalies for salinity, density, CDOM, particle backscattering and silicate were significantly correlated with river discharge. Precipitation and river discharge appear to be playing a critical role in controlling the long-term productivity of the Gulf of Maine by supplying CDOM and detrital material, which ultimately competes with phytoplankton for light absorption.

  17. [Impact of hydraulic retention time (HRT) in ABR on its operation performance and granular sludge characteristics when treating low-strength wastewater].

    PubMed

    Du, Jie-Di; Wang, Yi-Li; Li, Jiong; Xu, Xin-Zhao; Wei, Ke-Ji

    2009-07-15

    The impact of hydraulic retention time (HRT) in an anaerobic baffled reactor (ABR) on its operation performance and granular sludge characteristics was investigated through both testing its operation and analyzing the particle size distribution (PSD) and fractal dimensions of these sludge granules when treating low-strength wastewater. As HRT was gradually reduced from 24 h to 5 h, ABR had good performance on the organics removal and could reach about 90% for the COD removal, the VFA contents in ABR effluent and their pH values showed opposite trends. Most COD in wastewater was removed in the first two compartments of ABR during the running period of HRT from 24 h to 12 h, after that, the middle three compartments in ABR performed the most removal work. The MISS in latter compartments of ABR increased and the tendency of MLVSS/MISS ratios in the former three compartments were higher than that in the latter two ones appeared more and more remarkable along with the decrease of HRT. At HRT 24 h and 18 h, the granules grew bigger than before start-up,whose one-dimensional fractal dimension (D) decreased and two-dimensional fractal dimension (D2) increased, implying the smoother surface and more compact structure. As the HRT changed to 12 h and 8 h, the increasing D1 and decreasing D2 of granular sludge indicated its rougher surface and looser structure, and the bigger granules were formed with holes in their center. At HRT 5 h, smoother and more compact granules formed with smaller number median diameters of 0.72-0.82 mm than that at HRT 8 h. The looser granules were broken-up and some granules were discharged from ABR under the hydraulic disturbance and screening effect, at the same time, the growth of microorganism and their EPS (extracellular polymer substance) secretion could smooth the surface of the fragmentized granules. The fractal dimensions of granular sludge in the one-dimensional and two-dimensional topological spaces behaved inversely in each compartment

  18. Wavelet analysis of paleomagnetic data: 1. Characteristic average times (5 10 kyr) of variations in the geomagnetic field during and immediately before and after the Early Jaramillo reversal (Western Turkmenistan)

    NASA Astrophysics Data System (ADS)

    Gurarii, G. Z.; Aleksyutin, M. V.; Ataev, N.

    2007-10-01

    Joint wavelet analysis of complete and downsampled series of paleomagnetic and petromagnetic characteristics of rocks in the Matuyama-Jaramillo transitional zone in the Adzhidere section is used to extract paleomagnetic data whose variations are associated with the geomagnetic field alone and data correlating with variations in petromagnetic parameters. It supposed that this correlation can be caused by an external factor affecting weak variations in the magnetic field and climatic changes reflected in the composition and amount of the ferromagnetic fraction in rocks. Preliminary data are obtained for the characteristic times of field variations at the time of accumulation of rocks in the transitional zone.

  19. Wavelet analysis of paleomagnetic data: 5. Early Jaramillo reversal and main characteristic times in the interval from 3 to 70 ka in the variations of the elements of geomagnetic field (Western Turkmenia)

    NASA Astrophysics Data System (ADS)

    Gurarii, G. Z.

    2013-01-01

    The data on the variations in the elements of the geomagnetic field with the characteristic times of 3-70 ka during the 180-ka interval that includes the final stage of the Matuyama chron, the Jaramillo subchron, and the Early Jaramillo reversal are presented. A series of particular features are revealed in the variations. It is shown that such detailed characteristics of the variations, which might be critical for identifying the causes of the reversals, can only be derived by thorough investigation of the sedimentary rocks that were accumulated during very long time intervals (many hundreds of years) and slowly cooling intrusions.

  20. Comparison of performance characteristics of three real-time reverse transcription-PCR test systems for detection and quantification of hepatitis C virus.

    PubMed

    Sábato, M Fernanda; Shiffman, Mitchell L; Langley, Michael R; Wilkinson, David S; Ferreira-Gonzalez, Andrea

    2007-08-01

    We evaluated the performance characteristics of three real-time reverse transcription-PCR test systems for detection and quantification of hepatitis C virus (HCV) and performed a direct comparison of the systems on the same clinical specimens. Commercial HCV panels (genotype 1b) were used to evaluate linear range, sensitivity, and precision. The Roche COBAS TaqMan HCV test for research use only (RUO) with samples processed on the MagNA Pure LC instrument (Roche RUO-MPLC) and Abbott analyte-specific reagents (ASR) with QIAGEN sample processing (Abbott ASR-Q) showed a sensitivity of 1.0 log(10) IU/ml with a linear dynamic range of 1.0 to 7.0 log(10) IU/ml. The Roche ASR in combination with the High Pure system (Roche ASR-HP) showed a sensitivity of 1.4 log(10) IU/ml with a linear dynamic range of 2.0 to 7.0 log(10) IU/ml. All of the systems showed acceptable reproducibility, the Abbott ASR-Q being the most reproducible of the three systems. Seventy-six clinical specimens (50 with detectable levels of HCV RNA and various titers and genotypes) were tested, and results were compared to those of the COBAS Amplicor HCV Monitor v2.0. Good correlation was obtained for the Roche RUO-MPLC and Abbott ASR-Q (R(2) = 0.84 and R(2) = 0.93, respectively), with better agreement for the Abbott ASR-Q. However, correlation (R(2) = 0.79) and agreement were poor for Roche ASR-HP, with bias relative to concentration and genotype. Roche ASR-HP underestimated HCV RNA for genotypes 3 and 4 as much as 2.19 log(10) IU/ml. Our study demonstrates that Roche RUO-MPLC and Abbott ASR-Q provided acceptable results and agreed sufficiently with the COBAS Amplicor HCV Monitor v2.0.

  1. Biomechanical characteristics of skeletal muscles and associations between running speed and contraction time in 8- to 13-year-old children.

    PubMed

    Završnik, Jernej; Pišot, Rado; Šimunič, Boštjan; Kokol, Peter; Blažun Vošner, Helena

    2017-02-01

    Objective To investigate associations between running speeds and contraction times in 8- to 13-year-old children. Method This longitudinal study analyzed tensiomyographic measurements of vastus lateralis and biceps femoris muscles' contraction times and maximum running speeds in 107 children (53 boys, 54 girls). Data were evaluated using multiple correspondence analysis. Results A gender difference existed between the vastus lateralis contraction times and running speeds. The running speed was less dependent on vastus lateralis contraction times in boys than in girls. Analysis of biceps femoris contraction times and running speeds revealed that running speeds of boys were much more structurally associated with contraction times than those of girls, for whom the association seemed chaotic. Conclusion Joint category plots showed that contraction times of biceps femoris were associated much more closely with running speed than those of the vastus lateralis muscle. These results provide insight into a new dimension of children's development.

  2. The reverse temper embrittlement characteristics of two sets of CrMo steel high temperature turbine bolts with different service times

    SciTech Connect

    Bulloch, J.H.

    1996-08-01

    This article describes a reverse temper embrittlement (RTE) assessment of two series of Cr-Mo turbine bolts that had experienced differing service times at operating temperatures of around 670 K. It was established that when RTE was identified, the condition was one of only partial embrittlement, and two distinct regimens, partial and nonembrittled, were clearly identified using a plot of average grain size, d, versus percent bulk phosphorus. The interface between the two stages of embrittlement could be described by the simple expression, d {times} (%P) = Constant. It was observed that the bolts with the longer service time, approx 1.76 {times} 10{sup 5} h, were more prone to embrittlement than those that had only been subjected to approx 6 {times} 10{sup 4} h of service. Finally, it was suggested that such embrittlement differences were the result of accumulated strain during service and not a result of service time per se.

  3. Production of nanocrystalline cellulose from an empty fruit bunches using sulfuric acid hydrolysis: Effect of reaction time on the molecular characteristics

    NASA Astrophysics Data System (ADS)

    Al-Dulaimi, Ahmed A.; R, Rohaizu; D, Wanrosli W.

    2015-06-01

    Nanocrystalline cellulose (NCC) was isolated from OPEFB pulp via sulfuric acid hydrolysis. The influence of reaction time to the molecular weight and surface charge of the NCC was investigated. Characterization of the product was carried out using zeta potential measurement and gel permeation chromatography test. Zeta potential measurement showed that the surface negative charge significantly increases with increasing reaction time. Gel permeation chromatography test indicates that molecular weight of NCC change variably with increasing of hydrolysis time. (Keywords: Nanocrystalline cellulose; acid hydrolysis; sulfate content; molecular weight)

  4. Answer to Critical Remarks or one More Time About the Mechanism of Limitation on the Energy Characteristics of a Copper Vapor Laser

    NASA Astrophysics Data System (ADS)

    Yudin, N. A.

    2014-05-01

    This work presents an additional analysis of the main positions of the publication by N. A. Yudin, M. R. Tret'yakova, and N. N. Yudin, "Influence of electrophysical processes in the discharge circuit on the energy characteristics of a copper vapor laser" (Russ. Phys. J., 55, No. 9, 1080 - 1090 (2013)) in response to the conclusion drawn in the work of P. A. Bokhan "On the question of the existence of high-frequency oscillations in the power supply circuits of a copper vapor laser and their influence on the lasing mechanism" (Russ. Phys. J., 57, No. 1, 124 - 127 (2014)) that the main positions of the given publication are in error. The analysis performed here confirms the validity of the main positions of publication [2].

  5. Quantifying the residence time and flushing characteristics of a shallow, back-barrier estuary: Application of hydrodynamic and particle tracking models

    USGS Publications Warehouse

    Defne, Zafer; Ganju, Neil K.

    2015-01-01

    Estuarine residence time is a major driver of eutrophication and water quality. Barnegat Bay-Little Egg Harbor (BB-LEH), New Jersey, is a lagoonal back-barrier estuary that is subject to anthropogenic pressures including nutrient loading, eutrophication, and subsequent declines in water quality. A combination of hydrodynamic and particle tracking modeling was used to identify the mechanisms controlling flushing, residence time, and spatial variability of particle retention. The models demonstrated a pronounced northward subtidal flow from Little Egg Inlet in the south to Pt. Pleasant Canal in the north due to frictional effects in the inlets, leading to better flushing of the southern half of the estuary and particle retention in the northern estuary. Mean residence time for BB-LEH was 13 days but spatial variability was between ∼0 and 30 days depending on the initial particle location. Mean residence time with tidal forcing alone was 24 days (spatial variability between ∼0 and 50 days); the tides were relatively inefficient in flushing the northern end of the Bay. Scenarios with successive exclusion of physical processes from the models revealed that meteorological and remote offshore forcing were stronger drivers of exchange than riverine inflow. Investigations of water quality and eutrophication should take into account spatial variability in hydrodynamics and residence time in order to better quantify the roles of nutrient loading, production, and flushing.

  6. Characteristics of the m2000 Automated Sample Preparation and Multiplex Real-Time PCR System for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae▿

    PubMed Central

    Marshall, R.; Chernesky, M.; Jang, D.; Hook, E. W.; Cartwright, C. P.; Howell-Adams, B.; Ho, S.; Welk, J.; Lai-Zhang, J.; Brashear, J.; Diedrich, B.; Otis, K.; Webb, E.; Robinson, J.; Yu, H.

    2007-01-01

    We evaluated a new real-time PCR-based prototype assay for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae developed by Abbott Molecular Inc. This assay is designed to be performed on an Abbott m2000 real-time instrument system, which consists of an m2000sp instrument for sample preparation and an m2000rt instrument for real-time PCR amplification and detection. The limit of detection of this prototype assay was determined to be 20 copies of target DNA for both C. trachomatis and N. gonorrhoeae, using serially diluted linearized plasmids. No cross-reactivity could be detected when 55 nongonococcal Neisseria isolates and 3 non-C. trachomatis Chlamydia isolates were tested at 1 million genome equivalents per reaction. Concordance with the Roche Amplicor, BDProbeTec ET, and Gen-Probe APTIMA Combo 2 tests was assessed using unlinked/deidentified surplus clinical specimens previously analyzed with these tests. For C. trachomatis, concordance for positive results ranged from 93.7% to 100%, while concordance for negative results ranged from 98.2% to 100%. For N. gonorrhoeae, concordance for positive and negative results ranged from 91.4% to 100% and 99.3% to 100%, respectively. A workflow analysis of the prototype assay was conducted to obtain information on throughput under laboratory conditions. At 48 samples/run, the time to first result for both C. trachomatis and N. gonorrhoeae was 4.5 h. A total of 135 patient specimens could be analyzed in 8.9 h, with 75 min of hands-on time. This study demonstrated the technical and clinical feasibility of the new Abbott real-time PCR C. trachomatis/N. gonorrhoeae assay. PMID:17202273

  7. Determination of the time delay in the case of two-path propagation on the basis of the attenuation characteristics for two adjacent frequencies

    NASA Technical Reports Server (NTRS)

    Gilroi, H. G.

    1979-01-01

    Pronounced fading occurring in the line of sight radio links at frequencies below 10 GHz can be traced to the effects of multipath propagation. Modulation disturbances depend on travel time differences between the direct wave and the wave which is reflected at atmospheric layers. A method described for the determination of the time delay is based on an indirect approach which utilizes the difference in fading at various frequencies. The method was employed in measurements involving a distance of 181 km. The results obtained in the measurement are discussed.

  8. Physico-chemical, textural and structural characteristics of sous-vide cooked pork cheeks as affected by vacuum, cooking temperature, and cooking time.

    PubMed

    Sánchez Del Pulgar, José; Gázquez, Antonio; Ruiz-Carrascal, Jorge

    2012-03-01

    This paper describes the influence of different factors on sous-vide cooked pork. Pork cheeks were cooked at different combinations of temperature (60°C or 80°C), time (5 or 12h) and vacuum (vacuum or air packaged). Weight losses were lower and moisture content higher in samples cooked for a shorter time (P=0.054) and at a lower temperature (P<0.001). Samples cooked at 60°C showed more lightness (L*) and redness (a*) (P<0.001). Lipid oxidation showed an interaction between cooking time and temperature (P=0.007), with higher TBARs values for samples cooked for 12h at 60°C and lower for those cooked for 12h at 80°C. Samples cooked at 80°C for 12h showed lower (P<0.05) values for most textural parameters than all the other types of samples. Vacuum packaging showed no influence on any of the studied variables. For the treatments evaluated, cooking temperature×time combination seems to be more important than vacuum packaging in the textural and colour parameters of pork cheeks.

  9. Influence of Selected Personal Characteristics and County Situational Factors on Time Allocated to Dairy Subjects by Extension Agents in Selected Tennessee Counties.

    ERIC Educational Resources Information Center

    Northcutt, Sherwin Dean; And Others

    The study deals with various predictors of time spent on dairy subjects by Extension agents and predictors of contacts made by agents with dairy clientele. Purposes were to determine the relationships, if any, between various independent variables and groups of independent variables (agents' background and training, county dairy situation, agents'…

  10. Investigating the Impact of Orientation and Detected Characteristics of First-Time Online Students on Their Success Rate in a Community College Setting

    ERIC Educational Resources Information Center

    Akpom, Reginald

    2013-01-01

    It is evident that the failure rate is higher among online students than in-class students at Hopkinsville Community College. An analysis of the academic records of students who enrolled in online courses for the first time at Hopkinsville indicated a 13% higher withdrawal and failure rate than those who took in-class courses over the same period…

  11. Annealing time dependence of the physical, electrical and pH response characteristics of spin coated TiO2 thin films

    NASA Astrophysics Data System (ADS)

    Zulkefle, M. A.; Rahman, R. A.; Yusoff, K. A.; Abdullah, W. F. H.; Rusop, M.; Herman, S. H.

    2015-11-01

    Titanium dioxide (TiO2) thin film was deposited on indium tin oxide (ITO) substrate and used as sensing membrane of EGFET pH sensor. The thin film was fabricated using sol- gel spin coating method. All samples were annealed at 400 °C but the annealing time was varied. This is done to study the effects of annealing time on physical and electrical properties of titanium dioxide thin film. The sensitivity of each sample towards H+ ion was measured and result shows that sample annealed for 45 minutes has the highest sensitivity (52.6 mV/pH). It is found that increasing annealing duration will increase the pH sensitivity but a limit will be reached at certain point. Longer annealing processes done beyond this point will results in lower pH sensitivity.

  12. Characteristics of radiation and propagation of seismic waves in the Baikal Rift Zone estimated by simulations of acceleration time histories of the recorded earthquakes

    NASA Astrophysics Data System (ADS)

    Pavlenko, O. V.; Tubanov, Ts. A.

    2017-01-01

    The regularities in the radiation and propagation of seismic waves within the Baikal Rift Zone in Buryatia are studied to estimate the ground motion parameters from the probable future strong earthquakes. The regional parameters of seismic radiation and propagation are estimated by the stochastic simulation (which provides the closest agreement between the calculations and observations) of the acceleration time histories of the earthquakes recorded by the Ulan-Ude seismic station. The acceleration time histories of the strongest earthquakes ( M W 3.4-4.8) that occurred in 2006-2011 at the epicentral distances of 96-125 km and had source depths of 8-12 km have been modeled. The calculations are conducted with estimates of the Q-factor which were previously obtained for the region. The frequency-dependent attenuation and geometrical spreading are estimated from the data on the deep structure of the crust and upper mantle (velocity sections) in the Ulan-Ude region, and the parameters determining the wave forms and duration of acceleration time histories are found by fitting. These parameters fairly well describe all the considered earthquakes. The Ulan-Ude station can be considered as the reference bedrock station with minimum local effects. The obtained estimates for the parameters of seismic radiation and propagation can be used for forecasting the ground motion from the future strong earthquakes and for constructing the seismic zoning maps for Buryatia.

  13. Characteristics of the time course of evoked secretion of transmitter quanta in different parts of the motor nerve ending in the frog.

    PubMed

    Nikol'kii, E E; Bukharaeva, E A; Samigullin, D V; Gainulo, R Kh

    2002-01-01

    Experiments were performed on neuromuscular preparations from frogs, in which three extracellular microelectrodes were used to record nerve ending currents and single-quantum endplate currents simultaneously from the proximal, central, and distal parts of single synaptic contacts. The rate of propagation of excitation across terminals was measured. along with the minimum synaptic delay, the intensity. and the degree of synchronicity of the secretion of transmitter quanta in different parts of the nerve ending, and the relationships between these factors and the calcium ion concentration in the medium. These studies showed that along with gradients in the rate of conduction of excitation and the intensity of secretion in different parts of the ending. there were also differences in the kinetics of the release of transmitter quanta. As the distance from the end of the myelinated part of the axon increased, the rate of conduction of the nerve impulse and the duration of the synaptic delay decreased, while the synchronicity of the release of quanta increased. Increases in the calcium concentration in the medium produced greater increases in the synchronicity of transmitter quantum release in the distal parts of the synapse than in the proximal parts. Mathematical modeling of multiple-quantum endplate currents showed that the characteristics of the kinetics of the secretion process observed here in different parts of the nerve ending represent a factor which partially compensates for the decrease in the amplitude and extending of the duration of the leading front of the multiple-quantum endplate current which are associated with the low rate of conduction of excitation across the nerve ending. The contribution of this compensation increases as the intensity of secretion of transmitter quanta increases in the distal parts of the synaptic contact.

  14. Geostatistical Characteristic of Space -Time Variation in Underground Water Selected Quality Parameters in Klodzko Water Intake Area (SW Part of Poland)

    NASA Astrophysics Data System (ADS)

    Namysłowska-Wilczyńska, Barbara

    2016-04-01

    This paper presents selected results of research connected with the development of a (3D) geostatistical hydrogeochemical model of the Klodzko Drainage Basin, dedicated to the spatial and time variation in the selected quality parameters of underground water in the Klodzko water intake area (SW part of Poland). The research covers the period 2011÷2012. Spatial analyses of the variation in various quality parameters, i.e, contents of: ammonium ion [gNH4+/m3], NO3- (nitrate ion) [gNO3/m3], PO4-3 (phosphate ion) [gPO4-3/m3], total organic carbon C (TOC) [gC/m3], pH redox potential and temperature C [degrees], were carried out on the basis of the chemical determinations of the quality parameters of underground water samples taken from the wells in the water intake area. Spatial and time variation in the quality parameters was analyzed on the basis of archival data (period 1977÷1999) for 22 (pump and siphon) wells with a depth ranging from 9.5 to 38.0 m b.g.l., later data obtained (November 2011) from tests of water taken from 14 existing wells. The wells were built in the years 1954÷1998. The water abstraction depth (difference between the terrain elevation and the dynamic water table level) is ranged from 276÷286 m a.s.l., with an average of 282.05 m a.s.l. Dynamic water table level is contained between 6.22 m÷16.44 m b.g.l., with a mean value of 9.64 m b.g.l. The latest data (January 2012) acquired from 3 new piezometers, with a depth of 9÷10m, which were made in other locations in the relevant area. Thematic databases, containing original data on coordinates X, Y (latitude, longitude) and Z (terrain elevation and time - years) and on regionalized variables, i.e. the underground water quality parameters in the Klodzko water intake area determined for different analytical configurations (22 wells, 14 wells, 14 wells + 3 piezometers), were created. Both archival data (acquired in the years 1977÷1999) and the latest data (collected in 2011÷2012) were analyzed

  15. Diagnostic stability of autism spectrum disorder in toddlers prospectively identified in a community-based setting: Behavioural characteristics and predictors of change over time.

    PubMed

    Barbaro, Josephine; Dissanayake, Cheryl

    2016-07-28

    Autism spectrum disorder diagnoses in toddlers have been established as accurate and stable across time in high-risk siblings and clinic-referred samples. Few studies have investigated diagnostic stability in children prospective identified in community-based settings. Furthermore, there is a dearth of evidence on the individual behaviours that predict diagnostic change over time. The stability and change of autism spectrum disorder diagnoses were investigated from 24 to 48 months in 77 children drawn from the Social Attention and Communication Study. Diagnostic stability was high, with 88.3% overall stability and 85.5% autism spectrum disorder stability. The behavioural markers at 24 months that contributed to diagnostic shift off the autism spectrum by 48 months included better eye contact, more directed vocalisations, the integration of gaze and directed vocalisations/gestures and higher non-verbal developmental quotient. These four variables correctly predicted 88.7% of children into the autism spectrum disorder-stable and autism spectrum disorder-crossover groups overall, with excellent prediction for the stable group (96.2%) and modest prediction for the crossover group (44.4%). Furthermore, non-verbal developmental quotient at 24 months accounted for the significant improvement across time in 'Social Affect' scores on the Autism Diagnostic Observation Schedule for both groups and was the only unique predictor of diagnostic crossover. These findings contribute to the body of evidence on the feasibility of diagnoses at earlier ages to facilitate children's access to interventions to promote positive developmental outcomes.

  16. Effects of preslaughter feed withdrawal time on finishing pig carcass, body weight gain, and food safety characteristics in a commercial environment.

    PubMed

    Frobose, H L; Dritz, S S; Tokach, M D; Prusa, K J; DeRouchey, J M; Goodband, R D; Nelssen, J L

    2014-08-01

    The effects of feed withdrawal time before slaughter on finishing pig carcass composition were evaluated in 2 studies. In Exp. 1, 728 pigs (BW = 128.9 ± 1.2 kg) were allotted to 1 of 4 treatments in a randomized design with number of pigs per pen and location within barn balanced across treatment. The 4 treatments were feed withdrawal times of 8, 24, 36, or 48 h and there were 12 replicate pens per treatment. Before feed withdrawal, pigs were fed a standard corn-soybean meal diet containing dried distillers grains with solubles (DDGS), bakery coproducts, and 5.0 mg/kg ractopamine HCl. Feed withdrawal time decreased (linear; P < 0.02) live weight, HCW, and backfat while increasing percentage yield (quadratic; P < 0.01) and fat-free lean index (FFLI; linear; P < 0.001). In Exp. 2, 843 pigs (BW = 125.4 ± 1.6 kg) were used to determine the impact of feed withdrawal on growth, carcass, blood lactate, and meat quality. There were 4 treatments: withholding feed for 8, 12, 24, or 36 h, with 10 replicates per treatment. Pigs were fed a common corn-soybean meal-based diet containing 20% DDGS and 5.0 mg/kg ractopamine HCl. Withholding feed decreased (linear; P < 0.001) live weight, ultimately resulting in decreased (P < 0.01) HCW. There were no differences in FFLI or backfat, but percentage yield (linear; P < 0.001) increased with longer withdrawal times. Carcass contaminations by stomach contents escaping from the oral cavity after shackling (leaking ingesta) or visible fecal contamination of the exterior of the carcass (runny bung) were also measured. Although withholding feed did not affect runny bung, it increased (linear; P < 0.001) the incidence of leaking ingesta, whereas blood lactate, visual color score, and purge loss were unaffected. Withholding feed increased 45-min pH (quadratic; P > 0.02) and ultimate pH (linear; P < 0.01) and increased (quadratic; P < 0.03) visual marbling score. Withholding feed decreased (linear; P < 0.001) feed intake, resulting in feed

  17. Effect of different alcohols, gelatinizing times, calcination and microwave on characteristics of TiO2 nanoparticles synthesized by sol-gel method

    NASA Astrophysics Data System (ADS)

    Bahar, Mahmoud; Mozaffari, Masoud; Esmaeili, Sahar

    2017-02-01

    In this work, nanoparticles of titanium dioxide (TiO2) were synthesized by means of TiCl4 as precursor. Effects of alcohol type, calcination, gelatinizing time and microwave exposure on the particle size, morphology, crystallinity and particle phase are studied using XRD patterns and SEM images. Results showed that alcohols such as ethanol increased the particle size; calcination increased the particle size and improved the crystallinity of particles. Microwave exposure of particles resulted in smaller particles; adding water increased the impact of microwave. Effect of microwave exposure in rutile phase formation is also observed during this study.

  18. Influence of soil properties and climate characteristics on transpirable soil water for two varieties with differences in their crop cycle timing

    NASA Astrophysics Data System (ADS)

    Ramos, Maria C.

    2014-05-01

    This paper presents an analysis of soil water content in two vineyards planted with Chardonnay and Cabernet Sauvignon in the Penedès Designation of Origin (DO). Climate is Mediterranean with maritime influence. The main soil types are Typic Xerorthent and Fluventic Haploxerept and soil is bare most of the time to avoid the competition of weeds for water. The plantation pattern was uniform in both cultivars, 1.3*3m. Soil moisture was analysed at each area from 10 to 90 cm every 20 cm, using TDF probes during two crop growing cycles (2010-2012). Soil water balance for years with different rainfall amount and distribution throughout the year was simulated using the Soil and Water Assessment Tool (SWAT). Differences in phenology of about one month existed among both varieties. In addition, the soil hydrological properties variability, resulted from land levelling operations before vineyard establishment, affects crop's soil water availability. These two facts made that, under the same rainfall amount and distribution, water available during the crop cycle were different for both varieties. The transpirable soil water fraction reached very low values, close to 0.1, particularly in the variety with early phenology timing. This pattern was repeated in different years depending on rainfall distribution, which affected grape production with significant yield reductions (up to 38% in relation to the average were found in some years).

  19. Effect of mean cell residence time on transmembrane flux, mixed-liquor characteristics and overall performance of a submerged anaerobic membrane bioreactor.

    PubMed

    Pacheco-Ruiz, Santiago; Heaven, Sonia; Banks, Charles J

    2017-05-01

    Kinetic control of Mean Cell Residence Time (MCRT) was shown to have a significant impact on membrane flux under steady-state conditions. Two laboratory-scale flat-plate submerged anaerobic membrane bioreactors were operated for 245 days on a low-to-intermediate strength substrate with high suspended solids. Transmembrane pressure was maintained at 2.2 kPa throughout four experimental phases, while MCRT in one reactor was progressively reduced. This allowed very accurate measurement of sustainable membrane flux rates at different MCRTs, and hence the degree of membrane fouling. Performance data were gathered on chemical oxygen demand (COD) removal efficiency, and a COD mass balance was constructed accounting for carbon converted into new biomass and that lost in the effluent as dissolved methane. Measurements of growth yield at each MCRT were made, with physical characterisation of each mixed liquor based on capillary suction time. The results showed membrane flux and MLSS filterability was highest at short MCRT, although specific methane production (SMP) was lower since a proportion of COD removal was accounted for by higher biomass yield. There was no advantage in operating at an MCRT <25 days. When considering the most suitable MCRT there is thus a trade-off between membrane performance, SMP and waste sludge yield.

  20. Embedded Protostars in the Dust, Ice, and Gas In Time (DIGIT) Herschel Key Program: Continuum SEDs, and an Inventory of Characteristic Far-infrared Lines from PACS Spectroscopy

    NASA Astrophysics Data System (ADS)

    Green, Joel D.; Evans, Neal J., II; Jørgensen, Jes K.; Herczeg, Gregory J.; Kristensen, Lars E.; Lee, Jeong-Eun; Dionatos, Odysseas; Yildiz, Umut A.; Salyk, Colette; Meeus, Gwendolyn; Bouwman, Jeroen; Visser, Ruud; Bergin, Edwin A.; van Dishoeck, Ewine F.; Rascati, Michelle R.; Karska, Agata; van Kempen, Tim A.; Dunham, Michael M.; Lindberg, Johan E.; Fedele, Davide; DIGIT Team

    2013-06-01

    We present 50-210 μm spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 μm spectral energy distributions, as part of the Dust, Ice, and Gas in Time Key Program. Some sources exhibit up to 75 H2O lines ranging in excitation energy from 100 to 2000 K, 12 transitions of OH, and CO rotational lines ranging from J = 14 → 13 up to J = 40 → 39. [O I] is detected in all but one source in the entire sample; among the sources with detectable [O I] are two very low luminosity objects. The mean 63/145 μm [O I] flux ratio is 17.2 ± 9.2. The [O I] 63 μm line correlates with L bol, but not with the time-averaged outflow rate derived from low-J CO maps. [C II] emission is in general not local to the source. The sample L bol increased by 1.25 (1.06) and T bol decreased to 0.96 (0.96) of mean (median) values with the inclusion of the Herschel data. Most CO rotational diagrams are characterized by two optically thin components ({\\langle { {N}}\\rangle} = (0.70 +/- 1.12){{} \\times 10^{49}} total particles). { {N}}_CO correlates strongly with L bol, but neither T rot nor { {N}}_CO(warm)/{ {N}}_CO(hot) correlates with L bol, suggesting that the total excited gas is related to the current source luminosity, but that the excitation is primarily determined by the physics of the interaction (e.g., UV-heating/shocks). Rotational temperatures for H2O ({\\langle {T_rot}\\rangle } = 194 +/- 85 K) and OH ({\\langle {T_rot}\\rangle } =183 +/- 117 K) are generally lower than for CO, and much of the scatter in the observations about the best fit is attributed to differences in excitation conditions and optical depths among the detected lines. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. Time-domain analysis of bandgap characteristics of two-dimensional periodic structures by use of a source-model technique.

    PubMed

    Ludwig, Alon; Leviatan, Yehuda

    2008-02-01

    We introduce a time-domain source-model technique for analysis of two-dimensional, transverse-magnetic, plane-wave scattering by a photonic crystal slab composed of a finite number of identical layers, each comprising a linear periodic array of dielectric cylinders. The proposed technique takes advantage of the periodicity of the slab by solving the problem within a unit cell of the periodic structure. A spectral analysis of the temporal behavior of the fields scattered by the slab shows a clear agreement between frequency bands where the spectral density of the transmitted energy is low and the bandgaps of the corresponding two-dimensionally infinite periodic structure. The effect of the bandwidth of the incident pulse and its center frequency on the manner it is transmitted through and reflected by the slab is studied via numerical examples.

  2. Sentinel site-enhanced near-real time surveillance documenting West Nile virus circulation in two Culex mosquito species indicating different transmission characteristics, Djibouti City, Djibouti.

    PubMed

    Faulde, Michael K; Spiesberger, Michael; Abbas, Babiker

    2012-08-01

    The Horn of Africa represents a region formerly known to be highly susceptible to mosquito-borne infectious diseases. In order to investigate whether autochthonous WNV transmission occurs in the Djibouti City area, in how far, and which of, the endemic Culex mosquito species are involved in WNV circulation activity,and whether sentinel site-enhanced near-real time surveillance (SSE-NRTS) may increase WNV detection sensitivity, mosquito vector monitoring was conducted from January 2010 to June 2012. Six monitoring locations, including two identified sentinel sites, considered most probable for potential anthroponotic and zoonotic virus circulation activity, have been continuously employed. Among the 20431 mosquitoes collected, 19069 (93.4%) were Cx. quinquefasciatus, and 1345 (6.6%) Cx. pipiens ssp. torridus. WNV lineage 2 circulation activity was detected between December 20th, 2010 and January 7th, 2011. Overall, 19 WNV RNA-positive mosquito pools were detected. Generally, urban environment-specific WNV-RNA circulation took place in Cx. pipiens ssp. torridus, whereas periurban and rural area-linked circulation was detected only in Cx. quinquefasciatus. Serological investigation data from 10 volunteers employed at the dislocated zoonotic WNV transmission sentinel site suggest that six persons (60%) had an acute, or recent, WNV infection. Results show that WNV should be considered endemic for Djibouti and sentinel site-enhanced near-real time surveillance is an elegant and highly effective epidemiological tool. In Djibouti, the endemicity level, public health impact and transmission modes of vector-borne diseases in concordance with locally optimized monitoring and control regimen deserve further investigation.

  3. EMBEDDED PROTOSTARS IN THE DUST, ICE, AND GAS IN TIME (DIGIT) HERSCHEL KEY PROGRAM: CONTINUUM SEDs, AND AN INVENTORY OF CHARACTERISTIC FAR-INFRARED LINES FROM PACS SPECTROSCOPY

    SciTech Connect

    Green, Joel D.; Evans, Neal J. II; Rascati, Michelle R.; Jorgensen, Jes K.; Dionatos, Odysseas; Lindberg, Johan E.; Herczeg, Gregory J.; Kristensen, Lars E.; Yildiz, Umut A.; Van Kempen, Tim A.; Lee, Jeong-Eun; Salyk, Colette; Meeus, Gwendolyn; Bouwman, Jeroen; Visser, Ruud; Bergin, Edwin A.; Van Dishoeck, Ewine F.; Karska, Agata; Fedele, Davide; Dunham, Michael M.; Collaboration: DIGIT Team1

    2013-06-20

    We present 50-210 {mu}m spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 {mu}m spectral energy distributions, as part of the Dust, Ice, and Gas in Time Key Program. Some sources exhibit up to 75 H{sub 2}O lines ranging in excitation energy from 100 to 2000 K, 12 transitions of OH, and CO rotational lines ranging from J = 14 {yields} 13 up to J = 40 {yields} 39. [O I] is detected in all but one source in the entire sample; among the sources with detectable [O I] are two very low luminosity objects. The mean 63/145 {mu}m [O I] flux ratio is 17.2 {+-} 9.2. The [O I] 63 {mu}m line correlates with L{sub bol}, but not with the time-averaged outflow rate derived from low-J CO maps. [C II] emission is in general not local to the source. The sample L{sub bol} increased by 1.25 (1.06) and T{sub bol} decreased to 0.96 (0.96) of mean (median) values with the inclusion of the Herschel data. Most CO rotational diagrams are characterized by two optically thin components ( = (0.70 {+-} 1.12) x 10{sup 49} total particles). N{sub CO} correlates strongly with L{sub bol}, but neither T{sub rot} nor N{sub CO}(warm)/N{sub CO}(hot) correlates with L{sub bol}, suggesting that the total excited gas is related to the current source luminosity, but that the excitation is primarily determined by the physics of the interaction (e.g., UV-heating/shocks). Rotational temperatures for H{sub 2}O ( = 194 +/- 85 K) and OH ( = 183 +/- 117 K) are generally lower than for CO, and much of the scatter in the observations about the best fit is attributed to differences in excitation conditions and optical depths among the detected lines.

  4. Highly time-resolved urban aerosol characteristics during springtime in Yangtze River Delta, China: insights from soot particle aerosol mass spectrometry

    NASA Astrophysics Data System (ADS)

    Wang, Junfeng; Ge, Xinlei; Chen, Yanfang; Shen, Yafei; Zhang, Qi; Sun, Yele; Xu, Jianzhong; Ge, Shun; Yu, Huan; Chen, Mindong

    2016-07-01

    In this work, the Aerodyne soot particle - aerosol mass spectrometer (SP-AMS) was deployed for the first time during the spring of 2015 in urban Nanjing, a megacity in the Yangtze River Delta (YRD) of China, for online characterization of the submicron aerosols (PM1). The SP-AMS enables real-time and fast quantification of refractory black carbon (rBC) simultaneously with other non-refractory species (ammonium, sulfate, nitrate, chloride, and organics). The average PM1 concentration was found to be 28.2 µg m-3, with organics (45 %) as the most abundant component, following by sulfate (19.3 %), nitrate (13.6 %), ammonium (11.1 %), rBC (9.7 %), and chloride (1.3 %). These PM1 species together can reconstruct ˜ 44 % of the light extinction during this campaign based on the IMPROVE method. Chemically resolved mass-based size distributions revealed that small particles especially ultrafine ones (< 100 nm vacuum aerodynamic diameter) were dominated by organics and rBC, while large particles had significant contributions from secondary inorganic species. Source apportionment of organic aerosols (OA) yielded four OA subcomponents, including hydrocarbon-like OA (HOA), cooking-related OA (COA), semi-volatile oxygenated OA (SV-OOA), and low-volatility oxygenated OA (LV-OOA). Overall, secondary organic aerosol (SOA, equal to the sum of SV-OOA and LV-OOA) dominated the total OA mass (55.5 %), but primary organic aerosol (POA, equal to the sum of HOA and COA) can outweigh SOA in the early morning and evening due to enhanced human activities. High OA concentrations were often associated with high mass fractions of POA and rBC, indicating the important role of anthropogenic emissions during heavy pollution events. The diurnal cycles of nitrate, chloride, and SV-OOA both showed good anti-correlations with air temperatures, suggesting their variations were likely driven by thermodynamic equilibria and gas-to-particle partitioning. On the other hand, in contrast to other species

  5. Comparison of the detection characteristics of trace species using laser-induced breakdown spectroscopy and laser breakdown time-of-flight mass spectrometry.

    PubMed

    Wang, Zhenzhen; Deguchi, Yoshihiro; Yan, Junjie; Liu, Jiping

    2015-03-11

    The rapid and precise element measurement of trace species, such as mercury, iodine, strontium, cesium, etc. is imperative for various applications, especially for industrial needs. The elements mercury and iodine were measured by two detection methods for comparison of the corresponding detection features. A laser beam was focused to induce plasma. Emission and ion signals were detected using laser-induced breakdown spectroscopy (LIBS) and laser breakdown time-of-flight mass spectrometry (LB-TOFMS). Multi-photon ionization and electron impact ionization in the plasma generation process can be controlled by the pressure and pulse width. The effect of electron impact ionization on continuum emission, coexisting molecular and atomic emissions became weakened in low pressure condition. When the pressure was less than 1 Pa, the plasma was induced by laser dissociation and multi-photon ionization in LB-TOFMS. According to the experimental results, the detection limits of mercury and iodine in N2 were 3.5 ppb and 60 ppb using low pressure LIBS. The mercury and iodine detection limits using LB-TOFMS were 1.2 ppb and 9.0 ppb, which were enhanced due to different detection features. The detection systems of LIBS and LB-TOFMS can be selected depending on the condition of each application.

  6. Comparison of the Detection Characteristics of Trace Species Using Laser-Induced Breakdown Spectroscopy and Laser Breakdown Time-of-Flight Mass Spectrometry

    PubMed Central

    Wang, Zhenzhen; Deguchi, Yoshihiro; Yan, Junjie; Liu, Jiping

    2015-01-01

    The rapid and precise element measurement of trace species, such as mercury, iodine, strontium, cesium, etc. is imperative for various applications, especially for industrial needs. The elements mercury and iodine were measured by two detection methods for comparison of the corresponding detection features. A laser beam was focused to induce plasma. Emission and ion signals were detected using laser-induced breakdown spectroscopy (LIBS) and laser breakdown time-of-flight mass spectrometry (LB-TOFMS). Multi-photon ionization and electron impact ionization in the plasma generation process can be controlled by the pressure and pulse width. The effect of electron impact ionization on continuum emission, coexisting molecular and atomic emissions became weakened in low pressure condition. When the pressure was less than 1 Pa, the plasma was induced by laser dissociation and multi-photon ionization in LB-TOFMS. According to the experimental results, the detection limits of mercury and iodine in N2 were 3.5 ppb and 60 ppb using low pressure LIBS. The mercury and iodine detection limits using LB-TOFMS were 1.2 ppb and 9.0 ppb, which were enhanced due to different detection features. The detection systems of LIBS and LB-TOFMS can be selected depending on the condition of each application. PMID:25769051

  7. Effects of in ovo injection of organic trace minerals and post-hatch holding time on broiler performance and bone characteristics.

    PubMed

    Oliveira, T F B; Bertechini, A G; Bricka, R M; Hester, P Y; Kim, E J; Gerard, P D; Peebles, E D

    2015-11-01

    Effects of the in ovo injection of organic Mn, Zn, and Cu in association with post-hatch (POH) feed and water restriction on the performance and physical-chemical bone parameters of male Ross × Ross 708 broilers were examined. On 17 d of incubation, a total of 1,872 eggs were subjected to in ovo injection using a commercial multi-egg injector. Treatments (TRT) includingd non-injected and diluent-injected controls. The respective Zn, Mn, and Cu levels (mg/mL) added to the diluent of the low (LMD) and high mineral (HMD) TRT groups were 0.181, 0.087, and 0.010, and 0.544, 0.260, and 0.030, respectively. The 4 TRT groups were then sub-divided into 2 POH holding time (HT) groups, with 15 birds randomly allocated to each of 6 replicate pens in each of the 8 groups. The first HT group (0HT) had immediate access to water and feed, and the second HT group (24HT) contained birds that were kept in transport baskets for 24 h before being released. Performance was determined and selected birds were subsequently necropsied and their tibiae extracted for analysis. In comparison to birds from 24HT group, those in the 0HT group had a higher BW gain and feed intake, and a lower FCR through 21 d POH. The percentage of bone ash of the birds belonging to the HMD group was higher than all other TRT on d 1 POH and was higher than the non-injection control group on d 21 POH. On d 1, the LMD and HMD groups had higher tibial Mn concentrations than those of the control groups. On d 7, bones from the HMD group had a higher concentration of Mn than did the non-injected control group, and likewise, on d 21 POH, had a higher concentration of Zn than did the control groups. In conclusion, a 24HT negatively affected the performance of the birds during the first 2 wk POH; however, the LMD and HMD TRT had a positive influence on bone mineralization.

  8. Study on influences of TiN capping layer on time-dependent dielectric breakdown characteristic of ultra-thin EOT high-k metal gate NMOSFET with kMC TDDB simulations

    NASA Astrophysics Data System (ADS)

    Xu, Hao; Yang, Hong; Luo, Wei-Chun; Xu, Ye-Feng; Wang, Yan-Rong; Tang, Bo; Wang, Wen-Wu; Qi, Lu-Wei; Li, Jun-Feng; Yan, Jiang; Zhu, Hui-Long; Zhao, Chao; Chen, Da-Peng; Ye, Tian-Chun

    2016-08-01

    The thickness effect of the TiN capping layer on the time dependent dielectric breakdown (TDDB) characteristic of ultra-thin EOT high-k metal gate NMOSFET is investigated in this paper. Based on experimental results, it is found that the device with a thicker TiN layer has a more promising reliability characteristic than that with a thinner TiN layer. From the charge pumping measurement and secondary ion mass spectroscopy (SIMS) analysis, it is indicated that the sample with the thicker TiN layer introduces more Cl passivation at the IL/Si interface and exhibits a lower interface trap density. In addition, the influences of interface and bulk trap density ratio N it/N ot are studied by TDDB simulations through combining percolation theory and the kinetic Monte Carlo (kMC) method. The lifetime reduction and Weibull slope lowering are explained by interface trap effects for TiN capping layers with different thicknesses. Project supported by the National High Technology Research and Development Program of China (Grant No. SS2015AA010601), the National Natural Science Foundation of China (Grant Nos. 61176091 and 61306129), and the Opening Project of Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of MicroElectronics of Chinese Academy of Sciences.

  9. Observation of thermal effects due to an optical incident signal and high fluence on InGaAs/InP multiple-quantum-well saturable absorber nonlinear mirrors: evolution of characteristics and time constants.

    PubMed

    Le Cren, Elodie; Lobo, Sébastien; Fève, Sylvain; Simon, Jean-Claude

    2006-09-10

    We observe the effects of a temperature increase on the characteristics of an InGaAs/InP multiple-quantum-well (MQW) saturable absorber (SA) in a microcavity provided by an optical input signal under normal incidence. The temperature increase on the nonlinear mirror (NLM) due to an optical signal depends on the energy time filling factor (FF) of this input signal (analogous to the signal's duty cycle, which is the ratio between the repetition period and the pulse duration) and hence depends on the repetition rate of the signal for a given pulse time width. This increase in temperature is mostly responsible for a shift in the reflectivity spectrum of the device toward higher wavelengths. In this experimental study, we show the shift of the resonance cavity versus the optical input power at high FF, and we evaluate the thermal time constant of an Fe-doped InGaAs/InP MQW NLM. Finally, we report the consequences of such thermal effects and high fluence on the reflectivity and contrast of two different InGaAs/InP NLMs when the input signal FF rises up to 25%, which gets close to telecommunication transmission conditions.

  10. A retrospective study on anthropometrical, physical fitness, and motor coordination characteristics that influence dropout, contract status, and first-team playing time in high-level soccer players aged eight to eighteen years.

    PubMed

    Deprez, Dieter N; Fransen, Job; Lenoir, Matthieu; Philippaerts, Renaat M; Vaeyens, Roel

    2015-06-01

    The goal of this article was twofold, and a 2-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance, and motor coordination characteristics that influence dropout from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a "club group" or a "dropout group." In the second study, cross-sectional data of anthropometry, physical performance, and motor coordination were retrospectively explored to investigate which characteristics influence future contract status (contract vs. no contract group) and first-team playing time for 72 high-level youth soccer players (mean age = 16.2 years). Generally, club players outperformed their dropout peers for motor coordination, soccer-specific aerobic endurance, and speed. Anthropometry and estimated maturity status did not discriminate between club and dropout players. Contract players jumped further (p = 0.011) and had faster times for a 5-m sprint (p = 0.041) than no contract players. The following prediction equation explains 16.7% of the variance in future playing minutes in adolescent youth male soccer players: -2,869.3 + 14.6 × standing broad jump. Practitioners should include the evaluation of motor coordination, aerobic endurance, and speed performances to distinguish high-level soccer players further succeeding a talent development program and future dropout players, between 8 and 16 years. From the age of 16 years, measures of explosivity are supportive when selecting players into a future professional soccer career.

  11. A retrospective study on anthropometrical, physical fitness and motor coordination characteristics that influence drop out, contract status and first-team playing time in high-level soccer players, aged 8 to 18 years.

    PubMed

    Deprez, Dieter; Fransen, Job; Lenoir, Matthieu; Philippaerts, Renaat M; Vaeyens, Roel

    2014-12-02

    The goal of this manuscript was twofold and a two-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance and motor coordination characteristics that influence drop out from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a 'club group' or a 'drop out group'. In the second study, cross-sectional data of anthropometry, physical performance and motor coordination were retrospectively explored to investigate which characteristics influence future contract status (contract vs. no contract group) and first-team playing time for 72 high-level youth soccer players (mean age=16.2 y).Generally, club players outperformed their drop out peers for motor coordination, soccer-specific aerobic endurance and speed. Anthropometry and estimated maturity status did not discriminate between club and drop out players. Contract players jumped further (p=0.011) and had faster times for a 5m sprint (p=0.041) than no contract players. The following prediction equation explains 16.7% of the variance in future playing minutes in adolescent youth male soccer players: -2869.3 + 14.6 * standing broad jump.Practitioners should include the evaluation of motor coordination, aerobic endurance and speed performances to distinguish high-level soccer players further succeeding a talent development program and future drop out players, between 8 and 16 years. From the age of 16 years, measures of explosivity are supportive when selecting players into a future professional soccer career.

  12. Characteristic Curves.

    ERIC Educational Resources Information Center

    Walkiewicz, Thomas A.; Kirk, James R.

    1994-01-01

    Describes an experiment designed to help students gain a better understanding of the characteristics of various electronic components by incorporating a dual-trace oscilloscope in the X-Y mode in addition to direct observations of phase shifts of various signals into a laboratory exercise. (ZWH)

  13. Decay time characteristics of La2O2S:Eu and La2O2S:Tb for use within an optical sensor for human skin temperature measurement.

    PubMed

    Yap, Sook Voon; Ranson, Robert M; Cranton, Wayne M; Koutsogeorgis, Demosthenes

    2008-09-20

    We focus on the development of a remote temperature sensing technology, i.e., an optical laser-based sensor, using thermographic phosphors for medical applications, particularly within an electromagnetically hostile magnetic resonance imaging (MRI) environment. A MRI scanner uses a strong magnetic field and radio waves to generate images of the inside of the body. The quality of the image improves with increasing magnetic resonance; however, the drawback of applying a greater magnetic strength is the inducement of heat into the body tissue. Therefore, monitoring the patient's temperature inside MRI is vital, but until now, a practical solution for temperature measurement did not exist. We show europium doped lanthanum oxysulphide (La(2)O(2)S:Eu) and terbium doped lanthanum oxysulphide (La(2)O(2)S:Tb) are both temperature sensitive to a low temperature range of 10-50 degrees C when under ultraviolet (UV) excitation. The emission spectra and decay time characteristics of these phosphors were demonstrated. The results indicate that La(2)O(2)S:Eu has a quenching rate of 13.7 m degrees C(-1) and 4 m degrees C(-1) at 512 nm and 538 nm, respectively. In addition, La(2)O(2)S:Tb has a lower quenching rate of 4.19 m degrees C(-1) at 548 nm due to its faster decay time.

  14. Decay time characteristics of La2O2S:Eu and La2O2S:Tb for use within an optical sensor for human skin temperature measurement

    SciTech Connect

    Yap, Sook Voon; Ranson, Robert M.; Cranton, Wayne M.; Koutsogeorgis, Demosthenes

    2008-09-20

    We focus on the development of a remote temperature sensing technology, i.e., an optical laser-based sensor, using thermographic phosphors for medical applications, particularly within an electromagnetically hostile magnetic resonance imaging (MRI) environment. A MRI scanner uses a strong magnetic field and radio waves to generate images of the inside of the body. The quality of the image improves with increasing magnetic resonance; however, the drawback of applying a greater magnetic strength is the inducement of heat into the body tissue. Therefore, monitoring the patient's temperature inside MRI is vital, but until now, a practical solution for temperature measurement did not exist. We show europium doped lanthanum oxysulphide (La2O2S:Eu) and terbium doped lanthanum oxysulphide (La2O2S:Tb) are both temperature sensitive to a low temperature range of 10-50 deg. C when under ultraviolet (UV) excitation. The emission spectra and decay time characteristics of these phosphors were demonstrated. The results indicate that La2O2S:Eu has a quenching rate of 13.7 m deg. C{sup -1} and 4 m deg. C{sup -1} at 512 nm and 538 nm, respectively. In addition, La2O2S:Tb has a lower quenching rate of 4.19 m deg. C{sup -1} at 548 nm due to its faster decay time.

  15. Predictors of delay discounting among smokers: education level and a Utility Measure of Cigarette Reinforcement Efficacy are better predictors than demographics, smoking characteristics, executive functioning, impulsivity, or time perception.

    PubMed

    Wilson, A George; Franck, Christopher T; Mueller, E Terry; Landes, Reid D; Kowal, Benjamin P; Yi, Richard; Bickel, Warren K

    2015-06-01

    Ninety-four smokers completed the delay discounting procedure for either hypothetical amounts of money, $10 (money) and $1000 (money) or hypothetical amounts of cigarettes ($10 and $1000 worth of cigarettes). We investigated how variables previously found to be related to rates of delay discounting accounted for the observed results. These variables included the following: demographic information, smoking characteristics, executive function abilities, impulsivity, time perception, and the Utility Measure of Cigarette Reinforcing Efficacy (UMCE). Education level and UMCE were each significantly correlated with 3 out of 4 of the discounting measures. Moreover, the largest effect sizes observed were between these two measures and the four discounting measures. All potential discounting predictors were also investigated using step-wise linear regression with Bayesian Information Criterion (BIC) analysis—these BIC models revealed that education level and UMCE accounted for large portions of the variance. We conclude that education level and UMCE were the most consistent predictors of discounting. This data is discussed within the framework of a widely accepted neuroeconomic model that suggests that two brain systems separately assess two separate facets of decision-making, and the interplay between these two systems determines self-control in smokers. We hypothesize that education level and UMCE may serve as surrogate measures of the functionality of these two systems and that discounting may be a sentinel measure of self-control.

  16. Effect of reducing and replacing pork fat on the physicochemical, instrumental and sensory characteristics throughout storage time of small caliber non-acid fermented sausages with reduced sodium content.

    PubMed

    Mora-Gallego, Héctor; Serra, Xavier; Guàrdia, Maria Dolors; Arnau, Jacint

    2014-05-01

    The effect of pork fat reduction (from 44% to 20% final fat content) and its partial substitution by sunflower oil (3% addition) on the physicochemical, instrumental and sensory properties throughout storage time of small caliber non-acid fermented sausages (fuet type) with reduced sodium content (with partial substitution of NaCl by KCl and K-lactate) and without direct addition of nitrate and nitrite (natural nitrate source used instead) was studied. Results showed that sausages with reduced fat (10% initial fat content) and with acceptable sensory characteristics can be obtained by adding to the shoulder lean (8% fat content) during the grinding, either 3.3% backfat (3% fat content) or 3% sunflower oil, both previously finely comminuted with lean. Furthermore, sunflower oil showed to be suitable for partial pork backfat substitution in very lean fermented sausages, conferring desirable sensory properties similar to those of sausages with standard fat content. The sensory quality of the sausages was maintained after three-month cold storage in modified atmosphere.

  17. Predictors of delay discounting among smokers: Education level and a Utility Measure of Cigarette Reinforcement Efficacy are better predictors than demographics, smoking characteristics, executive functioning, impulsivity, or time perception

    PubMed Central

    Wilson, A. George; Franck, Christopher T.; Mueller, E. Terry; Landes, Reid D.; Kowal, Benjamin P.; Yi, Richard; Bickel, Warren K.

    2015-01-01

    Ninety-four smokers completed the delay discounting procedure for either hypothetical amounts of money, $10 (money) and $1000 (money) or hypothetical amounts of cigarettes ($10 and $1000 worth of cigarettes). We investigated how variables previously found to be related to rates of delay discounting accounted for the observed results. These variables included the following: demographic information, smoking characteristics, executive function abilities, impulsivity, time perception, and the Utility Measure of Cigarette Reinforcing Efficacy (UMCE). Education level and UMCE were each significantly correlated with 3 out of 4 of the discounting measures. Moreover, the largest effect sizes observed were between these two measures and the four discounting measures. All potential discounting predictors were also investigated using step-wise linear regression with Bayesian Information Criterion (BIC) analysis — these BIC models revealed that education level and UMCE accounted for large portions of the variance. We conclude that education level and UMCE were the most consistent predictors of discounting. This data is discussed within the framework of a widely accepted neuroeconomic model that suggests that two brain systems separately assess two separate facets of decision-making, and the interplay between these two systems determines self-control in smokers. We hypothesize that education level and UMCE may serve as surrogate measures of the functionality of these two systems and that discounting may be a sentinel measure of self-control. PMID:25661991

  18. Three-dimensional modeling of diesel engine intake flow, combustion and emissions

    NASA Technical Reports Server (NTRS)

    Reitz, R. D.; Rutland, C. J.

    1992-01-01

    A three-dimensional computer code (KIVA) is being modified to include state-of-the-art submodels for diesel engine flow and combustion: spray atomization, drop breakup/coalescence, multi-component fuel vaporization, spray/wall interaction, ignition and combustion, wall heat transfer, unburned HC and NOx formation, soot and radiation, and the intake flow process. Improved and/or new submodels which were completed are: wall heat transfer with unsteadiness and compressibility, laminar-turbulent characteristic time combustion with unburned HC and Zeldo'vich NOx, and spray/wall impingement with rebounding and sliding drops. Results to date show that adding the effects of unsteadiness and compressibility improves the accuracy of heat transfer predictions; spray drop rebound can occur from walls at low impingement velocities (e.g., in cold-starting); larger spray drops are formed at the nozzle due to the influence of vaporization on the atomization process; a laminar-and-turbulent characteristic time combustion model has the flexibility to match measured engine combustion data over a wide range of operating conditions; and finally, the characteristic time combustion model can also be extended to allow predictions of ignition. The accuracy of the predictions is being assessed by comparisons with available measurements. Additional supporting experiments are also described briefly. To date, comparisons with measured engine cylinder pressure and heat flux data were made for homogeneous charge, spark-ignited and compression-ignited engines. The model results are in good agreement with the experiments.

  19. Hypersonic Laminar-Turbulent Transition on Slender Cones at Zero Angle of Attack: Measurements in Support of Mechanism-Based Models for Scaling Ground-Test Data to Flight

    DTIC Science & Technology

    2011-03-04

    Public Release, Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Maintaining low laminar heating may be critical to hypersonic gliding ...critical to hypersonic gliding reentry vehicles such as the several which have been proposed for the Prompt Global Strike (PGS) mission. Tran- sition...transition is critical to gliding hypersonic reentry vehicles and hyper- sonic airbreathing cruise vehicles, such as those presently being developed under

  20. Experimental investigation on aero-optical aberration of shock wave/boundary layer interactions

    NASA Astrophysics Data System (ADS)

    Ding, Haolin; Yi, Shihe; Fu, Jia; He, Lin

    2016-10-01

    After streaming through the flow field which including the expansion, shock wave, boundary, etc., the optical wave would be distorted by fluctuations in the density field. Interactions between laminar/turbulent boundary layer and shock wave contain large number complex flow structures, which offer a condition for studying the influences that different flow structures of the complex flow field have on the aero-optical aberrations. Interactions between laminar/turbulent boundary layer and shock wave are investigated in a Mach 3.0 supersonic wind tunnel, based on nanoparticle-tracer planar laser scattering (NPLS) system. Boundary layer separation/attachment, induced suppression waves, induced shock wave, expansion fan and boundary layer are presented by NPLS images. Its spatial resolution is 44.15 μm/pixel. Time resolution is 6ns. Based on the NPLS images, the density fields with high spatial-temporal resolution are obtained by the flow image calibration, and then the optical path difference (OPD) fluctuations of the original 532nm planar wavefront are calculated using Ray-tracing theory. According to the different flow structures in the flow field, four parts are selected, (1) Y=692 600pixel; (2) Y=600 400pixel; (3) Y=400 268pixel; (4) Y=268 0pixel. The aerooptical effects of different flow structures are quantitatively analyzed, the results indicate that: the compressive waves such as incident shock wave, induced shock wave, etc. rise the density, and then uplift the OPD curve, but this kind of shock are fixed in space position and intensity, the aero-optics induced by it can be regarded as constant; The induced shock waves are induced by the coherent structure of large size vortex in the interaction between turbulent boundary layer, its unsteady characteristic decides the induced waves unsteady characteristic; The space position and intensity of the induced shock wave are fixed in the interaction between turbulent boundary layer; The boundary layer aero-optics are

  1. Laser Microprobe Mass Spectrometry 1: Basic Principles and Performance Characteristics.

    ERIC Educational Resources Information Center

    Denoyer, Eric; And Others

    1982-01-01

    Describes the historical development, performance characteristics (sample requirements, analysis time, ionization characteristics, speciation capabilities, and figures of merit), and applications of laser microprobe mass spectrometry. (JN)

  2. Effects of Time Specific F-strain Mycoplasma gallisepticum Inoculation Overlays on Prelay ts-11-strain M. gallisepticum Vaccination on Digestive and Reproductive Organ Characteristics of Commercial Egg-Laying Hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two trials were conducted to determine the effects of a prelay ts11-strain M. gallisepticum (ts11MG) vaccination alone or in conjunction with F-strain M. gallisepticum (FMG) inoculation overlays at 2 different age periods during lay on the digestive and reproductive organ characteristics of commerci...

  3. ILLIAC 4 systems characteristics and programming manual

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The latest edition is presented of the Systems Characteristics and Programming Manual of the ILLIAC 4 array and parallel disc memory system. The major aspects of the array described include: the array systems characteristics, programming characteristics, definition and flow charts, and timing. A glossary of terms, and an instruction index are included.

  4. Adjoint operator approach in marginal separation theory

    NASA Astrophysics Data System (ADS)

    Braun, Stefan; Scheichl, Stefan; Kluwick, Alfred

    2013-10-01

    Thin airfoils are prone to localized flow separation at their leading edge if subjected to moderate angles of attack α. Although 'laminar separation bubbles' at first do not significantly alter the airfoil performance, they tend to 'burst' if a is increased further or perturbations acting upon the flow reach a certain intensity. This then leads either to global flow separation (stall) or triggers the laminar-turbulent transition process within the boundary layer flow. The present paper addresses the asymptotic analysis of the early stages of the latter phenomenon in the limit as the characteristic Reynolds number Re → ∞, commonly referred to as marginal separation theory (MST). A new approach based on the adjoint operator method is presented to derive the fundamental similarity laws of MST and to extend the analysis to higher order. Special emphasis is placed on the breakdown of the flow description, i.e. the formation of finite time singularities (a manifestation of the bursting process), and its resolution based on asymptotic reasoning. The computation of the spatio-temporal evolution of the flow in the subsequent triple deck stage is performed by means of a Chebyshev spectral method. The associated numerical treatment of fractional integrals characteristic of MST is based on barycentric Lagrange interpolation, which is described in detail.

  5. Wavelet analysis of paleomagnetic data: 4. Characteristic short times (0.4-4.5 ky) of variations in the elements of the geomagnetic field during the early Jaramillo reversal and in the stationary field during the Matuyama and Jaramillo chrons (Western Turkmenia)

    NASA Astrophysics Data System (ADS)

    Gurarii, G. Z.; Aleksyutin, M. V.; Ataev, N. M.

    2012-04-01

    The geomagnetic variations with characteristic times ranging from 0.4 to 15 ka are shown to be largely stochastic. Variations with different characteristic times appear during different time intervals and reflect accelerating and decelerating processes. The variations do not exhibit any predominant times. At the same time, almost periodic variations in the lithological characteristics are clearly seen in the wavelet diagrams of the parameters that reflect the changes in the composition (quantitative and qualitative) of ferrimagnetic material; i.e., the changes in the conditions of sedimentation related to climate variations. The variations with periods of 5, 8.5, and 13 ka are concurrent with the similar variations in the paleomagnetic data, while the variations with a period of 3.5 ka are only observed in the magnetic parameters. We suggest that the first mentioned oscillations reflect the changes of the external (relative to the Earth) origin, whereas the changes with a period of 3.5 ka are caused by some terrestrial factors.

  6. Optical characteristics of lightning

    NASA Technical Reports Server (NTRS)

    Goodman, S. J.

    1985-01-01

    A study of the optical characteristics of cloud-to-ground dischargers and how they compare with intracloud flashes was completed. Time resolved optical (7774A) and electric field-change waveforms were measured above clouds from a U2 airplane coincident with ground-based measurements of lightning. The optical pulse trains are studied for within and between flash variability. Specifically, for each flash researchers examine the 10, 50 (full width half maximum), and 90 percent pulse widths; the 10-10, 10-50, 10-90, and 10-peak percent amplitude rise times; the radiances (optical power densities); radiant energy densities; and pulse intervals. The optical pulse characteristics of first strokes, subsequent strokes, the intracloud components of cloud-to-ground flashes and intracloud flashes as viewed from above cloud are shown to exhibit very similar waveshapes, radiances and radiant energy densities. Descriptive statistics on these pulse categories were tabulated for 25 visually confirmed cloud-to-ground flashes (229 optical pulses) and 232 intracloud flashes (3126 optical pulses). A companion study of lightning observations above and below cloud in storms, storm complexes, and mesoscale convective systems has also been completed. Researchers compared the mapping of total lightning activity from above clouds with ground-based measurements and storm evolution. Although the total (IC + CG) lightning activity is the more representative indication of thunderstorm growth and decay, the ground strike data can be used to locate, diagnose, and track storm evolution in a number of instances.

  7. The Use of a priori Information in ICA-Based Techniques for Real-Time fMRI: An Evaluation of Static/Dynamic and Spatial/Temporal Characteristics

    PubMed Central

    Soldati, Nicola; Calhoun, Vince D.; Bruzzone, Lorenzo; Jovicich, Jorge

    2013-01-01

    Real-time brain functional MRI (rt-fMRI) allows in vivo non-invasive monitoring of neural networks. The use of multivariate data-driven analysis methods such as independent component analysis (ICA) offers an attractive trade-off between data interpretability and information extraction, and can be used during both task-based and rest experiments. The purpose of this study was to assess the effectiveness of different ICA-based procedures to monitor in real-time a target IC defined from a functional localizer which also used ICA. Four novel methods were implemented to monitor ongoing brain activity in a sliding window approach. The methods differed in the ways in which a priori information, derived from ICA algorithms, was used to monitor a target independent component (IC). We implemented four different algorithms, all based on ICA. One Back-projection method used ICA to derive static spatial information from the functional localizer, off-line, which was then back-projected dynamically during the real-time acquisition. The other three methods used real-time ICA algorithms that dynamically exploited temporal, spatial, or spatial-temporal priors during the real-time acquisition. The methods were evaluated by simulating a rt-fMRI experiment that used real fMRI data. The performance of each method was characterized by the spatial and/or temporal correlation with the target IC component monitored, computation time, and intrinsic stochastic variability of the algorithms. In this study the Back-projection method, which could monitor more than one IC of interest, outperformed the other methods. These results are consistent with a functional task that gives stable target ICs over time. The dynamic adaptation possibilities offered by the other ICA methods proposed may offer better performance than the Back-projection in conditions where the functional activation shows higher spatial and/or temporal variability. PMID:23483841

  8. [The evolution over time of the in-vitro resistance of Plasmodium falciparum to antimalarial drugs in 2 areas of the Brazilian Amazonia with distinct socioeconomic and geographic characteristics].

    PubMed

    Couto, A A; Calvosa, V S; Santos, M A; de Souza, J M

    1995-01-01

    We evaluated the temporal progression of in vitro P. falciparum resistance to chloroquine, amodiaquine, quinine and mefloquine in two areas with distinct socioeconomical and geographical characteristics: Lourenço, in Amapá state and Paragominas, in Pará state. The former region is essentially an "open" gold mining camp, whereas the latter is one currently undergoing a colonization settlement process, in addition to expanding economical activities which mainly include cattle raising and wood exploitation. Our results show high resistance rates to chloroquine in the two study areas: 79.8% and 68.4% in Lourenço and Paragominas, respectively. Variations in the response of P. falciparum to both amodiaquine and quinine were recorded throughout the study period. On the other hand, no mefloquine P. falciparum resistant strains could be identified, despite the tact we had noted a decrease in sensitivity to this antimalarial drug throughout the study period.

  9. Analytical and clinical performance characteristics of the Abbott RealTime MTB RIF/INH Resistance, an assay for the detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis in pulmonary specimens.

    PubMed

    Kostera, Joshua; Leckie, Gregor; Tang, Ning; Lampinen, John; Szostak, Magdalena; Abravaya, Klara; Wang, Hong

    2016-12-01

    Clinical management of drug-resistant tuberculosis patients continues to present significant challenges to global health. To tackle these challenges, the Abbott RealTime MTB RIF/INH Resistance assay was developed to accelerate the diagnosis of rifampicin and/or isoniazid resistant tuberculosis to within a day. This article summarizes the performance of the Abbott RealTime MTB RIF/INH Resistance assay; including reliability, analytical sensitivity, and clinical sensitivity/specificity as compared to Cepheid GeneXpert MTB/RIF version 1.0 and Hain MTBDRplus version 2.0. The limit of detection (LOD) of the Abbott RealTime MTB RIF/INH Resistance assay was determined to be 32 colony forming units/milliliter (cfu/mL) using the Mycobacterium tuberculosis (MTB) strain H37Rv cell line. For rifampicin resistance detection, the Abbott RealTime MTB RIF/INH Resistance assay demonstrated statistically equivalent clinical sensitivity and specificity as compared to Cepheid GeneXpert MTB/RIF. For isoniazid resistance detection, the assay demonstrated statistically equivalent clinical sensitivity and specificity as compared to Hain MTBDRplus. The performance data presented herein demonstrate that the Abbott RealTime MTB RIF/INH Resistance assay is a sensitive, robust, and reliable test for realtime simultaneous detection of first line anti-tuberculosis antibiotics rifampicin and isoniazid in patient specimens.

  10. Flowfield-Dependent Mixed Explicit-Implicit (FDMEL) Algorithm for Computational Fluid Dynamics

    NASA Technical Reports Server (NTRS)

    Garcia, S. M.; Chung, T. J.

    1997-01-01

    Despite significant achievements in computational fluid dynamics, there still remain many fluid flow phenomena not well understood. For example, the prediction of temperature distributions is inaccurate when temperature gradients are high, particularly in shock wave turbulent boundary layer interactions close to the wall. Complexities of fluid flow phenomena include transition to turbulence, relaminarization separated flows, transition between viscous and inviscid incompressible and compressible flows, among others, in all speed regimes. The purpose of this paper is to introduce a new approach, called the Flowfield-Dependent Mixed Explicit-Implicit (FDMEI) method, in an attempt to resolve these difficult issues in Computational Fluid Dynamics (CFD). In this process, a total of six implicitness parameters characteristic of the current flowfield are introduced. They are calculated from the current flowfield or changes of Mach numbers, Reynolds numbers, Peclet numbers, and Damkoehler numbers (if reacting) at each nodal point and time step. This implies that every nodal point or element is provided with different or unique numerical scheme according to their current flowfield situations, whether compressible, incompressible, viscous, inviscid, laminar, turbulent, reacting, or nonreacting. In this procedure, discontinuities or fluctuations of an variables between adjacent nodal points are determined accurately. If these implicitness parameters are fixed to certain numbers instead of being calculated from the flowfield information, then practically all currently available schemes of finite differences or finite elements arise as special cases. Some benchmark problems to be presented in this paper will show the validity, accuracy, and efficiency of the proposed methodology.

  11. A proposal of the diagnosis-dynamic characteristic (DDC) model describing the relation between search time and confidence levels for a dichotomous judgment, and its application to ROC curve generation

    NASA Astrophysics Data System (ADS)

    Matsumoto, Toru; Fukuda, Nobuo; Furukawa, Akira; Suwa, Koji; Wada, Shinichi; Matsumoto, Mitsuomi; Sone, Shusuke

    2006-03-01

    When physicians inspect an image, they make up a certain degree of confidence that the image are abnormal; p(t), or normal; n(t)[n(t)=1-p(t)]. After infinite time of the inspection, they reach the equilibrium levels of the confidence of p*=p(∞) and n*=n(∞). There are psychological conflicts between the decisions of normal and abnormal. We assume that the decision of "normal" is distracted by the decision of "abnormal" by a factor of k(1 + ap), and in an inverse direction by a factor of k(1 + bn), where k ( > 0) is a parameter that relates with image quality and skill of the physicians, and a and b are unknown constants. After the infinite time of inspection, the conflict reaches the equilibrium, which satisfies the equation, k(1 + ap*)n* = k(1 + bn*)p*. Here we define a parameter C, which is 2p*/[p*(1 - p*)]. After the infinite time of inspection, the conflict reaches the equilibrium, which satisfies t that changes in the confidence level with the time (dp/dt) is proportional to [k(1+ap)n - k(1+bn)p], i.e. k[-cp2 + (c - 2)p + 1]. Solving the differential equation, we derived the equation; t(p) and p(t) depending with the parameters; k, c, S. S (0-1) is the value arbitrary selected and related with probability of "abnormal" before the image inspection (S = p(0)). Image reading studies were executed for CT images. ROC curves were generated both by the traditional 4-step score-based method and by the confidence level; p estimated from the equation t(p) of the DDC model using observed judgment time. It was concluded that ROC curves could be generated by measuring time for dichotomous judgment without the subjective scores of diagnostic confidence and applying the DDC model.

  12. Characteristics of Male Alcohol Offenders.

    ERIC Educational Resources Information Center

    Ratliff, Katharine G.; Ellis, Thomas E.

    Because most studies investigating psychological profiles of subjects convicted of driving under the influence of alcohol (DUI) have been conducted at the time of arrest or treatment, it is unclear whether subjects' anxiety, depression, and hostility represent "trait" characteristics central to alcohol abuse or "state"…

  13. An outbreak of infections caused by extensively drug-resistant Klebsiella pneumoniae strains during a short period of time in a Chinese teaching hospital: epidemiology study and molecular characteristics.

    PubMed

    Zhou, Tieli; Zhang, Yapei; Li, Meimei; Yu, Xiao; Sun, Yao; Xu, Jiru

    2015-07-01

    In this study, we comprehensively described the clinical risk factors, outcome, epidemiology, and molecular basis associated with an outbreak of extensively drug-resistant KPC-2-producing Klebsiella pneumoniae involving 15 patients in a teaching hospital from May 1 to June 27, 2013. Most of the patients were elderly and received long-term hospital treatment, and 40.0% (6/15) of them were dead. All strains carried bla(KPC-2), rmtB, bla(CTX-M-65), bla(SHV-11), oqxA, oqxB, and aac(6')-Ib-cr and even harbored additional other resistance genes, such as armA, bla(CTX-M-1), bla(TEM-1). bla(KPC-2), rmtB, and bla(CTX-M-65) were located on the same ~54.2-kb plasmid, and conjugation experiments further proved the cotransferable characteristic. Alterations of outer membrane proteins were confirmed by sodium dodecyl sulfate--olyacrylamide gelelectrophoresis and sequencing, which can lead to a drastic change in the permeability of cells. All isolates belonged to the clone complex 258, spreading rapidly across the world. Our study demonstrated that a high degree of awareness and surveillance of those drug resistance determinants is urgently needed.

  14. Characteristics of Yerevan High Transparency Scintillators

    SciTech Connect

    Zorn, Carl; Asryan, Gegham; Egiyan, Kim; Tarverdyan, M.; Amaryan, Moscov; Amaryan, Moskov; Demirchyan, Raphael; Stepanyan, Stepan; Burkert, Volker; Sharabian, Youri

    1992-08-01

    Optical transmission, light output and time characteristics are given for long scintillator strips fabricated at the Yerevan Physics Institute using the extrusion method. It is shown that at 45% relative (to anthracene) light output, good transmission (2.5/2.9 m attenuation length with photomultiplier direct readout and 3/3.5 m attenuation length fiber readout) and time characteristics (average decay time 2.8 nsec) were obtained.

  15. TaqMan real-time PCR assays to assess arbuscular mycorrhizal responses to field manipulation of grassland biodiversity: effects of soil characteristics, plant species richness, and functional traits.

    PubMed

    König, Stephan; Wubet, Tesfaye; Dormann, Carsten F; Hempel, Stefan; Renker, Carsten; Buscot, François

    2010-06-01

    Large-scale (temporal and/or spatial) molecular investigations of the diversity and distribution of arbuscular mycorrhizal fungi (AMF) require considerable sampling efforts and high-throughput analysis. To facilitate such efforts, we have developed a TaqMan real-time PCR assay to detect and identify AMF in environmental samples. First, we screened the diversity in clone libraries, generated by nested PCR, of the nuclear ribosomal DNA internal transcribed spacer (ITS) of AMF in environmental samples. We then generated probes and forward primers based on the detected sequences, enabling AMF sequence type-specific detection in TaqMan multiplex real-time PCR assays. In comparisons to conventional clone library screening and Sanger sequencing, the TaqMan assay approach provided similar accuracy but higher sensitivity with cost and time savings. The TaqMan assays were applied to analyze the AMF community composition within plots of a large-scale plant biodiversity manipulation experiment, the Jena Experiment, primarily designed to investigate the interactive effects of plant biodiversity on element cycling and trophic interactions. The results show that environmental variables hierarchically shape AMF communities and that the sequence type spectrum is strongly affected by previous land use and disturbance, which appears to favor disturbance-tolerant members of the genus Glomus. The AMF species richness of disturbance-associated communities can be largely explained by richness of plant species and plant functional groups, while plant productivity and soil parameters appear to have only weak effects on the AMF community.

  16. Characteristics of Pulsating Aurora

    NASA Astrophysics Data System (ADS)

    Humberset, B. K.; Gjerloev, J. W.; Mann, I. R.; Samara, M.; Michell, R.

    2013-12-01

    We have investigated the spatiotemporal characteristics of pulsating auroral patches observed with an all-sky imager located at Poker Flat, Alaska. Pulsating aurora often covers the entire sky with intermixed large and small-scale patches that vary in intensity or disappear and reappear on different time scales and timings. The broad definition of pulsating aurora covers patches and bands from tens to several tens of km which have a quasi-periodic temporal variation from 1 s to tens of seconds. In this paper we examine >15 patches from different events. We analyze all-sky movies (557.7 nm, 3.31 Hz) with a simple, yet robust, technique that allows us to determine the scale size dependent variability of the >15 individual patches. A spatial 2D Fourier Transform is used to separate the aurora into different horizontal scale sizes, and by correlating each patch for all image separations and available scale sizes smaller than the patch itself, we reveal what scale sizes are pulsating and their variability. The patches are found to be persistent, meaning that we can follow them for typically 5 minutes. The period of the pulsations is often remarkably variable and it seems that only certain scale sizes pulsate (typically the size of the patch). The patches drift with the background ExB plasma drift indicating that the magnetospheric source mechanism drifts with the field lines.

  17. Exploring Lightning Jump Characteristics

    NASA Technical Reports Server (NTRS)

    Chronis, Themis; Carey, Larry D.; Schultz, Christopher J.; Schultz, Elise; Calhoun, Kristin; Goodman, Steven J.

    2014-01-01

    This study is concerned with the characteristics of storms exhibiting an abrupt temporal increase in the total lightning flash rate (i.e., lightning jump, LJ). An automated storm tracking method is used to identify storm "clusters" and total lightning activity from three different lightning detection systems over Oklahoma, northern Alabama and Washington, D.C. On average and for different employed thresholds, the clusters that encompass at least one LJ (LJ1) last longer, relate to higher Maximum Expected Size of Hail, Vertical Integrated Liquid and lightning flash rates (area-normalized) than the clusters that did not exhibit any LJ (LJ0). The respective mean values for LJ1 (LJ0) clusters are 80 min (35 min), 14 mm (8 mm), 25 kg per square meter (18 kg per square meter) and 0.05 flash per min per square kilometer (0.01 flash per min per square kilometer). Furthermore, the LJ1 clusters are also characterized by slower decaying autocorrelation functions, a result that implies a less "random" behavior in the temporal flash rate evolution. In addition, the temporal occurrence of the last LJ provides an estimate of the time remaining to the storm's dissipation. Depending of the LJ strength (i.e., varying thresholds), these values typically range between 20-60 min, with stronger jumps indicating more time until storm decay. This study's results support the hypothesis that the LJ is a proxy for the storm's kinematic and microphysical state rather than a coincidental value.

  18. Thermistor Characteristics and Stability.

    ERIC Educational Resources Information Center

    Fricker, H. S.

    1987-01-01

    Discusses the uses of thermistors in teaching electronics and semiconductors. Describes how to experimentally measure and graph the characteristics of a thermistor. Suggests one possible approach to understand the shapes of the characteristics. (CW)

  19. Theory of Characteristics

    NASA Technical Reports Server (NTRS)

    Tollmien, W.

    1949-01-01

    The theory of characteristics will be presented generally for quasilinear differential equations of the second order in two variables. This is necessary because of the manifold requirements to be demanded from the theory of characteristics.

  20. Wetland Characteristics and Denitrification

    EPA Science Inventory

    This presentation serves as an initial summary of our wetland field work's watershed characteristics hydrologic characteristics, water quality measurements, and denitrification assays. We present our measurement results in the context of wetland type (Estuarine, Freshwater Mars...

  1. Timing and characteristics of Late Pleistocene and Holocene wetter periods in the Eastern Desert and Sinai of Egypt, based on 14C dating and stable isotope analysis of spring tufa deposits

    NASA Astrophysics Data System (ADS)

    Hamdan, Mohamed A.; Brook, George A.

    2015-12-01

    There is very little dated evidence on wet periods in the Eastern Desert and Sinai Peninsula of Egypt during the Late Pleistocene and Holocene. To obtain such information, we have studied the petrography, isotope geochemistry and AMS radiocarbon ages of mostly relict tufas deposited by springs draining perched ground water bodies in metamorphic and volcanic rocks. The tufas unconformably overly Precambrian basic igneous rocks (basalt, diabase and gabbro). As the ages of tufa carbonate are frequently older than the true ages of the deposits because of the incorporation of old, 14C-dead carbon, we have dated both the carbonate matrix and insoluble organic material of the tufas. These ages show that the tufas were largely formed during two broad time periods, the most recent from 12,058 to 6678 cal yr BP (African Humid Period), and the other from ˜31,200-22,500 cal yr BP, with preferential growth during the coldest times of this period namely during Heinrich Events 2 and 3 (H2 and H3) and the Last Glacial Maximum (LGM). The time span between 19,000-9000 cal yr BP, including the YD and H1, appears to have been relatively more arid than the earlier LGM or H2 periods or the later Holocene. The Late Pleistocene tufas are depleted in 18O relative to the Holocene tufas and were deposited at a lower temperature (˜14.0°-20.8 °C vs. 18.4°-23.4 °C). We believe that the Holocene tufas in the Sinai were formed by rainfall from the Mediterranean and those in the southern part of the Eastern Desert by African monsoon rainfall derived from the Red Sea-Gulf of Aden and Indian Ocean. In contrast, the moisture that fed the Late Pleistocene tufas, which are depleted in 18O relative to Holocene deposits, and progressively depleted from north to south, was probably brought by the Westerlies from the Atlantic-Mediterranean Sea when the Westerly circulation was pushed southwards during the coldest periods of the Late Pleistocene. Periods of tufa deposition correlate with major

  2. Time Dependent Fluids

    ERIC Educational Resources Information Center

    Collyer, A. A.

    1974-01-01

    Discusses the flow characteristics of thixotropic and negative thixotropic fluids; various theories underlying the thixotropic behavior; and thixotropic phenomena exhibited in drilling muds, commercial paints, pastes, and greases. Inconsistencies in the terminology used to label time dependent effects are revealed. (CC)

  3. The First Time

    ERIC Educational Resources Information Center

    Black, Beth

    2011-01-01

    In this article, the author narrates her experience of meeting a Montessori kid for the first time and shares the characteristics she observed in Montessori students. The author was working as director of academic resources in university housing at the University of Wisconsin-Madison and met Jason, a pre-med sophomore who was the resident…

  4. Time outs

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000756.htm Time outs To use the sharing features on this ... children, 2 to 12 years old. Why Does Time out Work? When you put children in time ...

  5. Switching Characteristics of Ferroelectric Transistor Inverters

    NASA Technical Reports Server (NTRS)

    Laws, Crystal; Mitchell, Coey; MacLeod, Todd C.; Ho, Fat D.

    2010-01-01

    This paper presents the switching characteristics of an inverter circuit using a ferroelectric field effect transistor, FeFET. The propagation delay time characteristics, phl and plh are presented along with the output voltage rise and fall times, rise and fall. The propagation delay is the time-delay between the V50% transitions of the input and output voltages. The rise and fall times are the times required for the output voltages to transition between the voltage levels V10% and V90%. Comparisons are made between the MOSFET inverter and the ferroelectric transistor inverter.

  6. Using vein fabric and fluid inclusion characteristics as an integrated proxy to constrain the relative timing of non cross-cutting, syn- to late-orogenic quartz vein generations

    NASA Astrophysics Data System (ADS)

    Jacques, Dominique; Muchez, Philippe; Sintubin, Manuel

    2014-05-01

    Research on ancient fluid systems mainly focuses on veins, because they offer the opportunity to combine macro- and microstructural data with geochemical data to gain insight into the P-T-X conditions present during veining. By applying such an integrated petrographic and microthermometric methodology to syn- to late-orogenic quartz veins in the Palaeozoic High-Ardenne slate belt (Belgium), we were able to define the relative timing and related P-T-X conditions of different quartz vein generations, despite of the absence of any mutual cross-cutting relationships in the field (Jacques et al., 2014). The different quartz vein generations represent the meso-scale brittle accommodation during fold initiation, amplification and locking. The presence of free polycrystal growth in cavities at a midcrustal depth, and fluid-assisted brecciation indicate that veining occurred under overpressured fluid conditions during the orogeny. Significant differences in crystal-plastic deformation microstructures and P-T trapping conditions indicate that the different processes accommodating folding occurred in a progressive manner along a retrograde deformation path. While vein quartz in an extrados vein and in the peripheral part of a lenticular, fault-accommodating vein shows moderate crystal-plastic deformation (e.g. bulging recrystallisation, deformation lamellae, shear bands), crystal-plastic deformation is relatively absent in the vein quartz of a saddle reef and the core of the lenticular vein (i.e. no to minor undulose extinction). Successive veining occurred from peak metamorphic conditions (ca. 300 ° C and 190 MPa), measured in the extrados vein, to lower P-T conditions in the periphery of the lenticular vein (ca. 275 ° C and 180 MPa), the late-orogenic saddle reef (ca. 245 ° C and 160 MPa) and the core of the lenticular vein (ca. 220 ° C and 150 MPa). The relative timing and accompanying decrease in P-T conditions of the different quartz vein generations reflect the

  7. Structural and Environmental Characteristics of Stereotyped Behaviors.

    ERIC Educational Resources Information Center

    Hall, Scott; Thorns, Tracy; Oliver, Chris

    2003-01-01

    This study examined structural characteristics and environmental variables in the stereotypic behaviors of eight individuals with developmental disabilities. Findings indicated that structural characteristics (percentage of time, bout length, and bout length variability) were highly correlated. Also, stereotyped behaviors were more likely to occur…

  8. Time Out for Time Management.

    ERIC Educational Resources Information Center

    Herr, Judy; And Others

    1995-01-01

    Discusses time management skills, noting that effective time management entails awareness of such things as how we use time and when our mental energy peaks and falls. Offers time management suggestions for day-care administrators such as developing a realistic "to-do" list, scheduling uninterrupted time to engage in important tasks, and limiting…

  9. Experimental investigation of the effect of polymer matrices on polymer fibre optic oxygen sensors and their time response characteristics using a vacuum testing chamber and a liquid flow apparatus.

    PubMed

    Chen, Rongsheng; Formenti, Federico; McPeak, Hanne; Obeid, Andrew N; Hahn, Clive; Farmery, Andrew

    2016-01-01

    Very fast sensors that are able to track rapid changes in oxygen partial pressure (PO2) in the gas and liquid phases are increasingly required in scientific research - particularly in the life sciences. Recent interest in monitoring very fast changes in the PO2 of arterial blood in some respiratory failure conditions is one such example. Previous attempts to design fast intravascular electrochemical oxygen sensors for use in physiology and medicine have failed to meet the criteria that are now required in modern investigations. However, miniature photonic devices are capable of meeting this need. In this article, we present an inexpensive polymer type fibre-optic, oxygen sensor that is two orders of magnitude faster than conventional electrochemical oxygen sensors. It is constructed with biologically inert polymer materials and is both sufficiently small and robust for direct insertion in to a human artery. The sensors were tested and evaluated in both a gas testing chamber and in a flowing liquid test system. The results showed a very fast T90 response time, typically circa 20 ms when tested in the gas phase, and circa 100 ms in flowing liquid.

  10. Experimental investigation of the effect of polymer matrices on polymer fibre optic oxygen sensors and their time response characteristics using a vacuum testing chamber and a liquid flow apparatus

    PubMed Central

    Chen, Rongsheng; Formenti, Federico; McPeak, Hanne; Obeid, Andrew N.; Hahn, Clive; Farmery, Andrew

    2016-01-01

    Very fast sensors that are able to track rapid changes in oxygen partial pressure (PO2) in the gas and liquid phases are increasingly required in scientific research – particularly in the life sciences. Recent interest in monitoring very fast changes in the PO2 of arterial blood in some respiratory failure conditions is one such example. Previous attempts to design fast intravascular electrochemical oxygen sensors for use in physiology and medicine have failed to meet the criteria that are now required in modern investigations. However, miniature photonic devices are capable of meeting this need. In this article, we present an inexpensive polymer type fibre-optic, oxygen sensor that is two orders of magnitude faster than conventional electrochemical oxygen sensors. It is constructed with biologically inert polymer materials and is both sufficiently small and robust for direct insertion in to a human artery. The sensors were tested and evaluated in both a gas testing chamber and in a flowing liquid test system. The results showed a very fast T90 response time, typically circa 20 ms when tested in the gas phase, and circa 100 ms in flowing liquid. PMID:26726286

  11. Flushing Time

    EPA Science Inventory

    The flushing time of an estuary is generally defined as the turnover time of fresh water in the estuary, that is, the time required to replace the fresh water contained in the estuary with freshwater inflow. Thus, the flushing time of an estuary is the ratio of the volume of fres...

  12. Reinventing Time

    ERIC Educational Resources Information Center

    Technology Teacher, 2004

    2004-01-01

    What do planet Earth, a swinging pendulum, a quartz crystal, and a Cesium atom have in common? They have all been used by humans to measure time. They represent humanity's progress through time in measuring time itself. But what is it, really, that humans set out to measure? Before time could be measured, somebody had to decide what to actually…

  13. Phylogenetic and molecular characteristics of Eurasian H9 avian influenza viruses and their detection by two different H9-specific RealTime reverse transcriptase polymerase chain reaction tests.

    PubMed

    Slomka, M J; Hanna, A; Mahmood, S; Govil, J; Krill, D; Manvell, R J; Shell, W; Arnold, M E; Banks, J; Brown, I H

    2013-03-23

    Avian influenza viruses (AIVs) of the H9 haemagglutinin subtype are endemic in many Asian and Middle-East countries, causing mortality and morbidity in poultry. Consequently there is a need for accurate and sensitive detection of Eurasian H9 subtype viruses. Two H9 RealTime reverse transcriptase polymerase chain reaction (RRT-PCR) tests, developed by Monne et al. (2008) and Ben Shabat et al. (2010), were originally validated with a limited number of H9 specimens. In the present study, the two tests have been assessed using 66 diverse H9 isolates and 139 clinical specimens from six H9 poultry outbreaks in four geographically disparate Eurasian countries. The Monne et al. (2008) test was modified and successfully detected all H9 viruses from all three Eurasian H9 lineages. Bayesian analysis of the clinical specimens' results revealed this test to be more sensitive (97%) than the Ben Shabat et al. (2010) test (31%). The latter test detected most H9 isolates of the G1 lineage, but no isolates from other H9 lineages. Mismatches in the primer/probe binding sequences accounted for sensitivity differences between the two H9 RRT-PCRs. Genetic analysis of 34 sequenced H9 haemagglutinin genes showed the South Asian and Middle-East H9 isolates to belong to the H9 G1 lineage, and possessed residues that appear to preferably bind alpha 2,6-linked sialic acid receptors which indicate a potential for human infection. European H9s clustered phylogenetically in a broader geographical group that includes recent North American H9 wild bird isolates and contemporary Asian viruses in the Y439 H9 lineage.

  14. Chua's Time

    NASA Astrophysics Data System (ADS)

    Buscarino, Arturo; Fortuna, Luigi; Frasca, Mattia

    2013-01-01

    We discuss the relationship between the idea of time of the philosopher Bergson and the concept of time recurrence in chaotic systems. By taking into account the Chua's circuit, we saw that the "Chua's time", i.e., the average recurrence time of trajectories in the Chua's circuit, is able to qualitatively represent the features of the Bergon's time. Numerical and experimental results are presented.

  15. VARIABLE TIME DELAY MEANS

    DOEpatents

    Clemensen, R.E.

    1959-11-01

    An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

  16. Fetal Alcohol Syndrome: Characteristics, Prevention, Treatment and Long Term Outlook.

    ERIC Educational Resources Information Center

    Seward, Cynthia A.; Barber, William H.

    1991-01-01

    This article discusses fetal alcohol syndrome (FAS) including causes, common characteristics, secondary characteristics, prevention, and treatment. Economic implications are noted which suggest that treatment costs are 100 times the cost of prevention programs. (DB)

  17. Inflight lightning characteristics measurement system

    NASA Technical Reports Server (NTRS)

    Pitts, F. L.; Thomas, M. E.; Campbell, R. E.; Thomas, R. M.; Zaepfel, K. P.

    1979-01-01

    A research data-gathering system being developed for inflight measurement of direct and nearby lightning strike characteristics is described. Wideband analog recorders used to record the lightning scenario are supplemented with high-sample-rate digital transient recorders with augmented memory capacity for increased time resolution of specific times of interest. The endless-loop data storage technique employed by the transient recorders circumvents problems associated with oscilloscopic techniques and allows unattended operation. System integrity and immunity from induced effects is accomplished by fiber-optics signal-transmission links, shielded system enclosures, and the use of a dynamotor for power system isolation.

  18. Entropic Time

    SciTech Connect

    Caticha, Ariel

    2011-03-14

    The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.

  19. Time Honoured

    ERIC Educational Resources Information Center

    Campbell, Mora; Timmerman, Peter

    2007-01-01

    The vast majority of literature and practices in environmental education focuses on places and spaces. Little attention has been paid to time and temporalities as elements of environments, and the ways in which how we experience time affects our experience of place. This paper is an examination of the ways in which reflection on time can be…

  20. Geologic Time.

    ERIC Educational Resources Information Center

    Newman, William L.

    One of a series of general interest publications on science topics, the booklet provides those interested in geologic time with an introduction to the subject. Separate sections discuss the relative time scale, major divisions in geologic time, index fossils used as guides for telling the age of rocks, the atomic scale, and the age of the earth.…

  1. Characteristics of Successful Entrepreneurs.

    ERIC Educational Resources Information Center

    McClelland, David C.

    1987-01-01

    Comparison of characteristics of 12 average and 12 superior small business people in three developing nations (India, Malawi, and Ecuador) found proactive qualities such as initiative and assertiveness, achievement orientation, and commitment to others characteristic of successful entrepreneurs. Other expected qualities (self-confidence,…

  2. Analysis of the Breakout Time

    SciTech Connect

    Medina, Brandon Michael

    2016-04-15

    The motivation to precisely determine breakout time is to better understand initial motion. An analysis on the baseline is conducted to determine breakout time. The power in the baseline drops by a factor of ~6 after the breakout time occurs. The characteristic rounded step function of the baseline power can be modeled to calculate the breakout time. The characteristic rounded step function of the phase change in the baseline can be modeled to calculate the breakout time. Power and phase both seem to be viable sources that can be used to find breakout time effectively. The phase and power methods complement one another, so whenever one method does not work, the other can still be used. In some cases, the breakout time can be slightly shifted between phase and power. In the future, it would be good to develop a way to quantify the breakout time as well as the associated precision and accuracy.

  3. Identification of Nonlinear Times Series from First Order Cumulative Characteristics.

    DTIC Science & Technology

    1991-08-01

    Jj by Aj. It can be checked that A = (Aj) converges in distribution to a Gaussian random vector with mean zero and covariance matrix having rl th...and order determination. Biometrika 77 669-687. Bartlett, M. S. (1954). Probl~mes de l’analyse spectrale des series temporelles stationnaires. Pub... series . Stoch. Process. Appl. 36 85-106. Hall, P. and Heyde, C. C. (1980). Martingale Limit Theory and its Applications. Academic Press, New York. Hall

  4. Characteristic time for halo current growth and rotation

    NASA Astrophysics Data System (ADS)

    Boozer, Allen

    2015-11-01

    Halo currents, Ih, flow in part through plasma on open magnetic lines and in part through the walls. A halo current has the same function as the wall current of a resistive wall mode and arises when a kink cannot be wall stabilized. When flowing in the plasma, the halo current can produce no forces, so j->h = (j∥ / B) B-> with B-> . ∇ -> j∥ / B = 0 . To avoid too strong a coupling to stable kinks, the wall interception must be of sufficient toroidal extent, which implies the width of the halo current channel Δh aIh /Ip , where aIh /Ip is the amplitude of the kink, a is the minor radius, and Ip is the plasma current. The equation for the growth of the halo current is dIh / dt =Ip /τg , where τg (μ0 /ηh) (a2 / 4) /seff and seff is a dimensionless stability coefficient. The rocket effect of the plasma flowing out of the two ends of the magnetic field lines in the halo can set the magnetic perturbation into toroidal rotation at a Mach number, Mh, comparable to unity. The rotation period is τr = (2 πR0 /Cs) /Mh , where R0 is the major radius and Cs =√{ (Te +Ti) /mi } is the speed of sound. NSTX results appear consistent for seff 0 . 5 , Mh 1 , and Te , i = 10 eV. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Award Number De-FG02-03ER54696.

  5. TIMING APPARATUS

    DOEpatents

    Bennett, A.E.; Geisow, J.C.H.

    1956-04-17

    The timing device comprises an escapement wheel and pallet, a spring drive to rotate the escapement wheel to a zero position, means to wind the pretensioned spring proportional to the desired signal time, and a cam mechanism to control an electrical signal switch by energizing the switch when the spring has been wound to the desired position, and deenergizing it when it reaches the zero position. This device produces an accurately timed signal variably witain the control of the operator.

  6. Geologic time

    USGS Publications Warehouse

    Newman, William L.

    2000-01-01

    The Earth is very old 4 1/2 billion years or more according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.

  7. Time Management

    ERIC Educational Resources Information Center

    Stoilov, Todor, Ed.

    2012-01-01

    The time management is worthy goal of many human activities. It concerns variety problems related to goals definition, assessment of available resources, control of management policies, scheduling of decisions. This book is an attempt to illustrate the decision making process in time management for different success stories, which can be used as…

  8. On Time

    NASA Astrophysics Data System (ADS)

    Cattaneo, Alberto S.; Schiavina, Michele

    2017-02-01

    This note describes the restoration of time in one-dimensional parameterization-invariant (hence timeless) models, namely, the classically equivalent Jacobi action and gravity coupled to matter. It also serves as a timely introduction by examples to the classical and quantum BV-BFV formalism as well as to the AKSZ method.

  9. Turnover Time

    EPA Science Inventory

    Ecosystems contain energy and materials such as carbon, nitrogen, phosphorus, and water, and are open to their flow-through. Turnover time refers to the amount of time required for replacement by flow-through of the energy or substance of interest contained in the system, and is ...

  10. Aircraft compass characteristics

    NASA Technical Reports Server (NTRS)

    Peterson, John B; Smith, Clyde W

    1937-01-01

    A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Characteristics of Navy aircraft compasses IV to IX and some other compasses are shown for the range of temperatures experienced in flight. Results of flight tests are presented. These results indicate that the characteristic most desired in a steering compass is a short period and, in a check compass, a low overswing.

  11. Utilizing Fractal Time

    NASA Astrophysics Data System (ADS)

    Marks-Tarlow, Terry

    Linear concepts of time plus the modern capacity to track history emerged out of circular conceptions characteristic of ancient and traditional cultures. A fractal concept of time lies implicitly within the analog clock, where each moment is treated as unique. With fractal geometry the best descriptor of nature, qualities of self-similarity and scale invariance easily model her endless variety and recursive patterning, both in time and across space. To better manage temporal aspects of our lives, a fractal concept of time is non-reductive, based more on the fullness of being than on fragments of doing. By using a fractal concept of time, each activity or dimension of life is multiply and vertically nested. Each nested cycle remains simultaneously present, operating according to intrinsic dynamics and time scales. By adding the vertical axis of simultaneity to the horizontal axis of length, time is already full and never needs to be filled. To attend to time's vertical dimension is to tap into the imaginary potential for infinite depth. To switch from linear to fractal time allows us to relax into each moment while keeping in mind the whole.

  12. Overview of NASA supported Stirling thermodynamic loss research

    NASA Astrophysics Data System (ADS)

    Tew, Roy C.; Geng, Steven M.

    NASA is funding research to characterize Stirling machine thermodynamic losses. NASA's primary goal is to improve Stirling design codes to support engine development for space and terrestrial power. However, much of the fundamental data is applicable to Stirling cooling and heat pump applications. The research results are reviewed. Much was learned about oscillating flow hydrodynamics, including laminar/turbulent transition, and tabulated data was documented for further analysis. Now, with a better understanding of the oscillating flow field, it is time to begin measuring the effects of oscillating flow and oscillating pressure level on heat transfer in heat exchanger flow passages and in cylinders.

  13. Overview of NASA supported Stirling thermodynamic loss research

    NASA Technical Reports Server (NTRS)

    Tew, Roy C.; Geng, Steven M.

    1992-01-01

    NASA is funding research to characterize Stirling machine thermodynamic losses. NASA's primary goal is to improve Stirling design codes to support engine development for space and terrestrial power. However, much of the fundamental data is applicable to Stirling cooling and heat pump applications. The research results are reviewed. Much was learned about oscillating flow hydrodynamics, including laminar/turbulent transition, and tabulated data was documented for further analysis. Now, with a better understanding of the oscillating flow field, it is time to begin measuring the effects of oscillating flow and oscillating pressure level on heat transfer in heat exchanger flow passages and in cylinders.

  14. Algorithm implementation on the Navier-Stokes computer

    NASA Technical Reports Server (NTRS)

    Krist, Steven E.; Zang, Thomas A.

    1987-01-01

    The Navier-Stokes Computer is a multi-purpose parallel-processing supercomputer which is currently under development at Princeton University. It consists of multiple local memory parallel processors, called Nodes, which are interconnected in a hypercube network. Details of the procedures involved in implementing an algorithm on the Navier-Stokes computer are presented. The particular finite difference algorithm considered in this analysis was developed for simulation of laminar-turbulent transition in wall bounded shear flows. Projected timing results for implementing this algorithm indicate that operation rates in excess of 42 GFLOPS are feasible on a 128 Node machine.

  15. Algorithms for international atomic time.

    PubMed

    Panfilo, Gianna; Arias, E Felicitas

    2010-01-01

    This article reviews the creation and technical evolution of atomic time scales. In particular, we focus our attention on the method of calculation and the characteristics of International Atomic Time (TAI), and show how it is disseminated at the ultimate level of precision.

  16. Onboard Navigation Systems Characteristics

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The space shuttle onboard navigation systems characteristics are described. A standard source of equations and numerical data for use in error analyses and mission simulations related to space shuttle development is reported. The sensor characteristics described are used for shuttle onboard navigation performance assessment. The use of complete models in the studies depend on the analyses to be performed, the capabilities of the computer programs, and the availability of computer resources.

  17. Housing characteristics 1993

    SciTech Connect

    1995-06-01

    This report, Housing Characteristics 1993, presents statistics about the energy-related characteristics of US households. These data were collected in the 1993 Residential Energy Consumption Survey (RECS) -- the ninth in a series of nationwide energy consumption surveys conducted since 1978 by the Energy Information Administration of the US Department of Energy. Over 7 thousand households were surveyed, representing 97 million households nationwide. A second report, to be released in late 1995, will present statistics on residential energy consumption and expenditures.

  18. Pluto Time

    NASA Video Gallery

    If you stood on Pluto at noon and looked around, the landscape would be illuminated about as brightly as on Earth soon after sunset. The team for NASA's New Horizons mission dubbed this "Pluto Time...

  19. Time out

    MedlinePlus

    ... but no more than 5 minutes. Once your child shows bad behavior, explain clearly what the unacceptable behavior is, and ... time out. Be ready with praise if your child stops the behavior. If the behavior does not stop, tell your ...

  20. About time

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1990-01-01

    Time has historically been a measure of progress of recurrent physical processes. Coordination of future actions, prediction of future events, and assigning order to events are three practical reasons for implementing clocks and signalling mechanisms. In large networks of computers, these needs lead to the problem of synchronizing the clocks throughout the network. Recent methods allow this to be done in large networks with precision around 1 millisecond despite mean message exchange times near 5 milliseconds. These methods are discussed.

  1. Part-time Work in International Perspective.

    ERIC Educational Resources Information Center

    Thurman, Joseph E.; Trah, Gabriele

    1990-01-01

    Examines the reasons for part-time work and characteristics of part-time workers, legislative protection, national incentives to increase access to part-time jobs, and forms of part-time work. Explores arguments for and against part-time employment. (SK)

  2. Variable nonlinear transfer characteristics of MSLM

    NASA Astrophysics Data System (ADS)

    Kobayashi, Yuji; Hara, Tsutomu; Suzuki, Yoshiji

    1990-08-01

    Variable nonlinear transfer characteristics (gamma characteristics) of microchannel spatial light modulator (MSLM) are investigated theoretically and experimentally. The MSLM structure and the principle of operation are discussed, and experimental results are presented. It is shown that the thresholding nonlinearities of the MSLM can be controlled by either the mesh voltage or by writing the time change in the thresholding operation. The resulting variable nonlinear transfer characteristics can be used in various optical processings such as a sigmoid function on optical neural networks and an analog operating on optical information processing.

  3. Brain Time and Physical Time

    NASA Astrophysics Data System (ADS)

    Fidelman, Uri

    The hemispheric paradigm verifies Kant's suggestion that time and space are our subjective modes of perceiving experience. Time and space are two modes of organizing the sensory input by the l- and right-hemispheric neural mechanisms, respectively. The neural structures of the l- and right-hemispheric mechanisms force our consciousness to perceive time as one-dimensional and propagating from the past towards the future, and space as a simultaneously perceived multidimensional structure. The introduction of temporal propagation from the future towards the past by Feynman and other physicists caused the transfer of the concept time from the l hemisphere (which cannot perceive this change of the temporal direction) to the right one. This transfer requires and allows for the introduction of additional temporal axes in order to solve paradoxes in physics.

  4. Number Time

    ERIC Educational Resources Information Center

    Herrera, Terese A.

    2004-01-01

    This article features Number Time, a site developed by the British Broadcasting Corporation (BBC) for young mathematics learners, located at www.bbc.co.uk/schools/numbertime. The site uses interactive animation to help children in pre-K through grade 2 understand and practice number basics. Users will find online games, videos that tell number…

  5. Geologic Time.

    ERIC Educational Resources Information Center

    Albritton, Claude C., Jr.

    1984-01-01

    Discusses the historical development of the concept of geologic time. Develops the topic by using the major discoveries of geologists, beginning with Steno and following through to the discovery and use of radiometric dating. An extensive reference list is provided. (JM)

  6. Characteristics of intuitive nurses.

    PubMed

    Miller, V G

    1995-06-01

    A description is provided of the process used to verify characteristics of intuitive nurses that had been reported in the literature. These characteristics supplied the framework for construction of the Miller Intuitiveness Instrument (MII) reported earlier (Miller, 1993). Evidence for validity of the MII was provided in the Miller (1993) study by examining factor analyses and correlations with the intuitive component of the Myers-Briggs Type Indicator (MBTI). The following characteristics were subsequently verified: Intuitive nurses are willing to act on their intuitions, are skilled clinicians, and incorporate a spiritual component in their practices. In addition, intuitive nurses express an interest in the abstract nature of things and are risk takers. Intuitive nurses prefer intuition to sensing (as reflected by the MBTI) as a way to take in information. They are extroverted and express confidence in their intuitions. Likewise, nurses who delay making decisions until all the information is in are more intuitive than those who make decisions abruptly.

  7. Commercial Buildings Characteristics, 1992

    SciTech Connect

    Not Available

    1994-04-29

    Commercial Buildings Characteristics 1992 presents statistics about the number, type, and size of commercial buildings in the United States as well as their energy-related characteristics. These data are collected in the Commercial Buildings Energy Consumption Survey (CBECS), a national survey of buildings in the commercial sector. The 1992 CBECS is the fifth in a series conducted since 1979 by the Energy Information Administration. Approximately 6,600 commercial buildings were surveyed, representing the characteristics and energy consumption of 4.8 million commercial buildings and 67.9 billion square feet of commercial floorspace nationwide. Overall, the amount of commercial floorspace in the United States increased an average of 2.4 percent annually between 1989 and 1992, while the number of commercial buildings increased an average of 2.0 percent annually.

  8. Watershed geomorphological characteristics

    USGS Publications Warehouse

    Fitzpatrick, Faith

    2016-01-01

    This chapter describes commonly used geomorphological characteristics that are useful for analyzing watershed-scale hydrology and sediment dynamics. It includes calculations and measurements for stream network features and areal basin characteristics that cover a range of spatial and temporal scales and dimensions of watersheds. Construction and application of longitudinal profiles are described in terms of understanding the three-dimensional development of stream networks. A brief discussion of outstanding problems and directions for future work, particularly as they relate to water-resources management, is provided. Notations with preferred units are given.

  9. Runoff characteristics of California streams

    USGS Publications Warehouse

    Rantz, S.E.

    1972-01-01

    runoff occurs during the 6 months, October through March. Base flow (ground-water outflow), as a factor in the regimen of streamflow, is qualified on the basis of the percentage of the mean annual runoff that occurs during the fair-weather months of August and September. If the sum of the August and September runoff exceeds 3.0 percent of the annual runoff, base flow is considered to be well sustained; if the percentage is between 1.5 and 3.0, base flow is considered to be fairly well sustained; if the percentage is less than 1.5, baseflow is considered to be poorly sustained. The characteristics of duration curves of daily streamflow are influenced by the regimen of runoff. The distribution of daily flow is skewed for all streams, but it is more skewed for streams whose flow is predominantly storm runoff than for streams that carry significantly large quantities of snowmelt. Least skewed is the distribution for streams that carry large quantities of base flow. Either of two characteristics of the duration curve may be used as an index of skew--the percentage of time that the mean discharge is equaled or exceeded or the ratio of the median discharge to the mean discharge. As for variability of daily discharge, the variability of storm-runoff streams is greater than that of snowmelt streams, and the lowest values of variability are associated with streams that carry large quantities of base flow. The index of variability used in this study was the ratio of the discharge equaled or exceeded 10 percent of the time to the discharge equaled or exceeded 90 percent of the time. The identification of streamflow characteristics by numerical index figures greatly facilitates comparison of the diverse runoff regimens of streams in the California Region.

  10. Metering Characteristics of Carburetors

    NASA Technical Reports Server (NTRS)

    Tice, Percival S; Dickinson, H C

    1919-01-01

    Report presents the results of an extensive experimental investigation of the performance of different types of carburetors as effecting the maintenance under all conditions of correct ratio between the weights of fuel and air. It also gives a description of the Bureau of Standards carburetor test plant, test equipment and measuring instruments used to determine the metering characteristics of carburetors.

  11. Gender and Learner Characteristics

    ERIC Educational Resources Information Center

    Hindal, Huda; Reid, Norman; Whitehead, Rex

    2013-01-01

    It is well established that girls and boys perform differently in traditional examinations in most countries. This study looks at a sample of 754 school students in Kuwait (aged about 13) and explores how boys and girls differ in the performance in a range of tests related to learner characteristics. The fundamental question is how boys and girls…

  12. Personality Characteristics of Engineers

    ERIC Educational Resources Information Center

    van der Molen, Henk T.; Schmidt, Henk G.; Kruisman, Gerard

    2007-01-01

    The objective of the current study was to investigate the personality characteristics of a group of engineers with a variety of years of experience. It was executed to remedy shortcomings of the literature concerning this issue and to produce suggestions for a postgraduate training programme for engineers. A total of 103 engineers were tested with…

  13. Characteristics of USB noise

    NASA Technical Reports Server (NTRS)

    Gibson, J. S.; Searle, N.

    1976-01-01

    An extensive series of noise measurements, for a variety of geometric and operational parameters, was made on models of upper surface blowing (USB) powered lift systems. The data obtained were analyzed and the effects and trends of parametric variation defined. The behavior and nature of USB noise and the design of USB systems with low noise characteristics is examined.

  14. Characteristics of Excellent Principals.

    ERIC Educational Resources Information Center

    Batsis, Thomas M.

    Recent business and education publications have stressed the excellence concept and the pivotal role of the executive. While effective business leaders are thought to possess certain characteristics, no consensus exists concerning educational leaders' roles. Although instructional leadership has received most attention in education literature,…

  15. Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L., Jr.

    2010-01-01

    Time-distance helioseismology is a method of ambient noise imaging using the solar oscillations. The basic realization that led to time-distance helioseismology was that the temporal cross correlation of the signals at two 'surface' (or photospheric) locations should show a feature at the time lag corresponding to the subsurface travel time between the locations. The temporal cross correlation, as a function of the location separation, is the Fourier transform of the spatio-temporal power spectrum of the solar oscillations, a commonly used function in helioseismology. It is therefore likely the characteristic ridge structure of the correlation function had been seen before without appreciation of its significance. Travel times are measured from the cross correlations. The times are sensitive to a number of important subsurface solar phenomena. These include sound speed variations, flows, and magnetic fields. There has been much interesting progress in the 17 years since the first paper on this subject (Duvall et al., Nature, 1993, 362, 430-432). This progress will be reviewed in this paper.

  16. Time Critical

    NASA Technical Reports Server (NTRS)

    Covault, Craig

    2005-01-01

    NASA's decision to slip launch of the space shuttle return-to-flight mission to no earlier than May 22 will provide engineers more time to complete final, rigorous assessments before the orbiter Discovery's final Flight Readiness Review (FRR). That FRR is now planned for May 10-11. It will be used by NASA and contractor managers to reaffirm the readiness of all program elements to support the new target to return the U.S. space program to manned launch operations. It will also enable them to better raise any final issues that could slip the target again, if necessary, to complete more work and documentation.

  17. Mexican-American Adolescents' Gender-Typed Characteristics: The Role of Sibling and Friend Characteristics.

    PubMed

    Perez-Brena, Norma J; Wheeler, Lorey A; Updegraff, Kimberly A; Schaefer, David R

    2015-07-01

    This study examined the role of sibling and friend characteristics in Mexican-American youth's gender-typed characteristics (i.e., attitudes, interests, and leisure activities) in early versus middle adolescence using a sibling design. Mexican-American 7th graders (M = 12.51 years; SD = .58) and their older siblings (M = 15.48 years; SD = 1.57) from 246 families participated in home interviews and a series of seven nightly phone calls. Results revealed that younger/early adolescent siblings reported more traditional gender role attitudes than their older/middle adolescent siblings and older brothers were more traditional in their attitudes than older sisters. When comparing siblings' gender-typed interests and leisure activities, boys reported more masculine orientations than girls and girls reported more feminine orientations than boys. Older brothers' gender-typed characteristics were associated with the amount of time spent with and gender characteristics of their friendship group, but for younger brothers, sibling characteristics were associated with their gender-typed characteristics. In contrast, both sibling and friendship characteristics were significantly associated with older and younger sisters' gender-typed characteristics. The discussion addressed the different correlates of older and younger sisters' and brothers' gender-typed characteristics.

  18. Mexican-American Adolescents’ Gender-Typed Characteristics: The Role of Sibling and Friend Characteristics

    PubMed Central

    Wheeler, Lorey A.; Updegraff, Kimberly A.; Schaefer, David R.

    2016-01-01

    This study examined the role of sibling and friend characteristics in Mexican-American youth’s gender-typed characteristics (i.e., attitudes, interests, and leisure activities) in early versus middle adolescence using a sibling design. Mexican-American 7th graders (M = 12.51 years; SD = .58) and their older siblings (M = 15.48 years; SD = 1.57) from 246 families participated in home interviews and a series of seven nightly phone calls. Results revealed that younger/early adolescent siblings reported more traditional gender role attitudes than their older/middle adolescent siblings and older brothers were more traditional in their attitudes than older sisters. When comparing siblings’ gender-typed interests and leisure activities, boys reported more masculine orientations than girls and girls reported more feminine orientations than boys. Older brothers’ gender-typed characteristics were associated with the amount of time spent with and gender characteristics of their friendship group, but for younger brothers, sibling characteristics were associated with their gender-typed characteristics. In contrast, both sibling and friendship characteristics were significantly associated with older and younger sisters’ gender-typed characteristics. The discussion addressed the different correlates of older and younger sisters’ and brothers’ gender-typed characteristics. PMID:25539774

  19. Characteristics of healthcare wastes

    SciTech Connect

    Diaz, L.F. Eggerth, L.L.; Enkhtsetseg, Sh.; Savage, G.M.

    2008-07-01

    A comprehensive understanding of the quantities and characteristics of the material that needs to be managed is one of the most basic steps in the development of a plan for solid waste management. In this case, the material under consideration is the solid waste generated in healthcare facilities, also known as healthcare waste. Unfortunately, limited reliable information is available in the open literature on the quantities and characteristics of the various types of wastes that are generated in healthcare facilities. Thus, sound management of these wastes, particularly in developing countries, often is problematic. This article provides information on the quantities and properties of healthcare wastes in various types of facilities located in developing countries, as well as in some industrialized countries. Most of the information has been obtained from the open literature, although some information has been collected by the authors and from reports available to the authors. Only data collected within approximately the last 15 years and using prescribed methodologies are presented. The range of hospital waste generation (both infectious and mixed solid waste fractions) varies from 0.016 to 3.23 kg/bed-day. The relatively wide variation is due to the fact that some of the facilities surveyed in Ulaanbaatar include out-patient services and district health clinics; these facilities essentially provide very basic services and thus the quantities of waste generated are relatively small. On the other hand, the reported amount of infectious (clinical, yellow bag) waste varied from 0.01 to 0.65 kg/bed-day. The characteristics of the components of healthcare wastes, such as the bulk density and the calorific value, have substantial variability. This literature review and the associated attempt at a comparative analysis point to the need for worldwide consensus on the terms and characteristics that describe wastes from healthcare facilities. Such a consensus would greatly

  20. Advanced turboprop vibratory characteristics

    NASA Technical Reports Server (NTRS)

    Srinivasan, A. V.; Fulton, G. B.

    1984-01-01

    The assembly of SR5 advanced turboprop blades to develop a structural dynamic data base for swept props is reported. Steady state blade deformation under centrifugal loading and vibratory characteristics of the rotor assembly were measured. Vibration was induced through a system of piezoelectric crystals attached to the blades. Data reduction procedures are used to provide deformation, mode shape, and frequencies of the assembly at predetermined speeds.