Sample records for laminar-turbulent characteristic time

  1. 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.

  2. Numerical Aerodynamic Optimization Incorporating Laminar-Turbulent Transition Prediction

    E-print Network

    Zingg, David W.

    Numerical Aerodynamic Optimization Incorporating Laminar-Turbulent Transition Prediction J. Driver-dimensional Newton­Krylov aerodynamic shape optimization algorithm is applied to several optimization problems a striking demonstration of the capability of the Newton­ Krylov aerodynamic optimization algorithm to design

  3. 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.

  4. Hypersonic laminar–turbulent transition on circular cones and scramjet forebodies

    Microsoft Academic Search

    Steven P. Schneider

    2004-01-01

    Laminar–turbulent transition in hypersonic boundary layers has a dramatic effect on heat transfer, skin friction, and separation. This effect is critical to reentry vehicles and airbreathing cruise vehicles, yet the physics of the transition process is not yet well enough understood to be used for predictive purposes. The literature for transition on circular cones and scramjet forebodies is reviewed, from

  5. 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 : ?P~1Pa at few 100Hz in the laminar region and ?P~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.

  6. 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.

  7. 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.

  8. 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 ?x=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. PMID:21382820

  9. A theoretical model and experiments on the nonlinear dynamics of parallel plates subjected to laminar/turbulent squeeze-film forces

    NASA Astrophysics Data System (ADS)

    Piteau, Philippe; Antunes, José

    2012-08-01

    Squeeze film dynamical effects are relevant in many industrial contexts, bearings and seals being the most conspicuous applications, but also in other industrial contexts, for instance when dealing with the seismic excitation of spent fuel racks. The significant nonlinearity of the squeeze-film forces which arise prevents the use of linearized flow models, and a fully nonlinear formulation must be used for adequate computational predictions. Because it can easily accommodate both laminar and turbulence flow effects, a simplified bulk-flow model based on gap-averaged Navier-Stokes equations, incorporating all relevant inertial and dissipative terms was previously developed by the authors, assuming a constant skin-friction coefficient. In this paper we develop an improved theoretical formulation, where the dependence of the friction coefficient on the local flow velocity is explicitly accounted for, such that it can be applied to laminar, turbulent and mixed flows. Numerical solutions for both the basic and improved nonlinear one-dimensional time-domain formulations are presented in the paper. Furthermore, we present and discuss the results of an extensive series of experiments performed at CEA/Saclay, which were performed on a test rig consisting on a long gravity-driven instrumented plate of rectangular shape colliding with a planar surface. Theoretical results stemming from both theoretical flow models are confronted with the experimental measurements, in order to assert the strengths and drawbacks of the simpler original model, as well as the improvements brought by the new but more involved flow formulation.

  10. An experimental study on laminar-turbulent transition at high free-stream turbulence in boundary layers with pressure gradients

    NASA Astrophysics Data System (ADS)

    Niebles Atencio, Bercelay; Chernoray, Valery; Jahanmiri, Mohsen

    2012-04-01

    We report here the results of a study on measurements and prediction of laminar-turbulent transition at high free-stream turbulence in boundary layers of the airfoil-like geometries with presence of the external pressure gradient changeover. The experiments are performed for a number of flow cases with different flow Reynolds number, turbulence intensity and pressure gradient distributions. The results were then compared to numerical calculations for same geometries and flow conditions. The experiments and computations are performed for the flow parameters which are typical for turbomachinery applications and the major idea of the current study is the validation of the turbulence model which can be used for such engineering applications.

  11. 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.

  12. Timing characteristics of scintillator bars

    NASA Astrophysics Data System (ADS)

    Denisov, S.; Dzierba, A.; Heinz, R.; Klimenko, A.; Samoylenko, V.; Scott, E.; Shchukin, A.; Smith, P.; Steffen, C.; Teige, S.

    2002-02-01

    The proposed Hall D detector at Jefferson Lab will have a time-of-flight detector composed of long and narrow scintillator bars. We have evaluated the time resolution of two bar prototypes in particle beams at the Institute for High Energy Physics in Protvino, Russia. The bars are 2.0 m long and have square cross-sections of size 2.5 and 5.0 cm2. In this paper, we present results on how the time resolution of each of these bars depends on the entry position of the beam into the scintillator, on the material used for scintillator wrapping and on the phototube used for the readout.

  13. Studies of "Kapustinsky's" light pulser timing characteristics

    E-print Network

    B. K. Lubsandorzhiev; Y. E. Vyatchin

    2004-10-29

    We present the results of studies of a nanosecond light pulser built following J.S.Kapustinsky et al original design and using bright InGaN/GaN ultraviolet and blue LEDs produced by NICHIA CHEMICAL. It is shown how timing characteristics of the pulser depend on the type of LED and the value of power supply voltage.

  14. A continuous time random walk model with multiple characteristic times

    NASA Astrophysics Data System (ADS)

    Sau Fa, Kwok; Mendes, R. S.

    2010-04-01

    In this paper we consider a continuous time random walk (CTRW) model with a decoupled jump pdf. Further, we consider an approximate jump length pdf; for the waiting time pdf we do not use any approximation and we employ a function which depends on multiple characteristic times given by a sum of exponential functions. This waiting time pdf can reproduce power-law behavior for intermediate times. Using this specific waiting time probability density, we analyze the behavior of the second moment generated by the CTRW model. It is known that the waiting time pdf given by an exponential function generates a normal diffusion process, but for our waiting time pdf the second moment can give an anomalous diffusion process for intermediate times, and the normal diffusion process is maintained for the long-time limit. We note that systems which present subdiffusive behavior for intermediate times but reach normal diffusion at large times have been observed in biology.

  15. 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.

  16. 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.

  17. Chaotic characteristics of the Southern Oscillation Index time series

    Microsoft Academic Search

    Akira Kawamura; Alistair I. McKerchar; Robert H. Spigel; Kenji Jinno

    1998-01-01

    The monthly time series of the Southern Oscillation Index (SOI) is analysed to examine its chaotic characteristics. Three schemes, moving average, low-pass filter and nonlinear smoothing, were used to reduce noise and enhance chaotic properties. Autocorrelation and spectral characteristics, as well as three chaos-oriented properties — phase space trajectory, the largest Lyapunov exponent and correlation dimension — were then examined.No

  18. Characteristic Variability Time Scales of Long Gamma-Ray Bursts

    E-print Network

    R. F. Shen; L. M. Song

    2003-06-07

    We determined the characteristic variability time scales (\\Delta t_p) of 410 bright and long GRBs, by locating the peaks of their Power Density Spectra, defined and calculated in the time domain. We found that the averaged variability time scale decreases with the peak flux. This is consistent with the time-dilation effect expected for the cosmological origin of GRBs. We also found that the occurrence distribution of the characteristic variability time scale shows bimodality, which might be interpreted as that the long GRB sample is composed of two sub-classes with different variability time scales. However, we found no difference for some other characteristics of these two sub-classes.

  19. Statistical characteristics of detectable inhomogeneities in observed meteorological time series

    Microsoft Academic Search

    Peter Domonkos; Petr Št?pánek

    2009-01-01

    Statistical characteristics of detectable inhomogeneities [IHs] in more than 600 observed meteorological time series have\\u000a been investigated using 16 objective homogenisation methods. Forty and 100 year long series of monthly or annual characteristics\\u000a of surface air temperature, precipitation total and relative air humidity from the Czech Republic and Hungary were examined.\\u000a The area of the part of the Czech observing

  20. Tailoring explicit time-marching schemes to improve convergence characteristics

    NASA Technical Reports Server (NTRS)

    Powell, Kenneth G.; Vanleer, Bram

    1990-01-01

    Multi-stage time-stepping schemes, tailored to chosen spatial-differencing operators, are derived and tested. The schemes are constructed to give optimal damping of the high-frequency waves. They are ideal for use with multi-grid acceleration. The concept of characteristic time-stepping, necessary for the extension of the scalar analysis to systems of equations, is presented. The schemes show a marked improvement over Runge-Kutta schemes.

  1. The characteristic averaging time for the surface-layer fluxes

    NASA Astrophysics Data System (ADS)

    Calaf, M.; Iungo, V.; Oldroyd, H. J.; Giometto, M. G.; Parlange, M. B.

    2014-12-01

    The choice of the representative averaging time to compute surface-layer fluxes remains a source of discrepancy between studies. While the Ogive function (Oncley et al. 1996) has become the standard approach to determine the 'physically sound' averaging time, uncertainty remains on how to precisely select the minimum-necessary averaging time. Alternatives based on a multiresolution analysis exist and they can further provide a characteristic time-scale separating turbulence from mesoscale motions (Vickers and Mahrt, 2003, 2005). Yet little is learned from the inherent turbulent time scales and their corresponding contribution to the overall surface-layer fluxes. Here a new approach based on a Proper Orthogonal Decomposition (POD) will be presented, where the extracted characteristic averaging times are energy optimal. Consequently one can now select from these POD-provided characteristic times, the most relevant time scales depending on the desired application and based on the overall energy contribution to the surface-layer fluxes. One of the main advantages of the POD-technique compared to traditional Fourier analysis or wavelet decompositions is that the shape of the eigenfunctions is directly dictated by the input data and that the resultant eigenfunctions are energy ordered in the most optimal sense. Thus, one can really determine a-priori the most 'physically relevant' averaging time without source of ambiguity. Examples of the proposed approach in varied complex scenarios will be presented, spanning multiple atmospheric stratifications and topography driven flows. Further, results exploring the potential of the POD technique to determine the proper averaging times for tilt corrections will also be presented.

  2. Potentially hazardous comet warning times, characteristics, trends and countermeasures

    NASA Astrophysics Data System (ADS)

    Phelps, Lyrica L.

    This research seeks to determine orbital trends and characteristics of comets discovered over recorded history; specifically "warning times" associated with comets that come within 1.3 astronomical unit (AU) of the Earth, called Near-Earth Objects (NEOs), and Potentially Hazardous Objects (PHOs) which come within 0.05 AU of Earth's Minimum Orbit Intersection Distance (MOID) . In this work, "warning time" means the time from discovery to perigee/closest approach to Earth, including negative warning times when the comet is discovered after close approach. This study proposes that warning times for comets approaching Earth should be increasing with increased telescope technology and an increased number of surveys focused on NEOs in the past decades. Quantification occurs by investigating all known comets through recorded history, restricting this group to relevant Near-Earth Comets (NECs), and predicting appearance and warning times of future comets using discovered trends. Data for this study was obtained from the Jet Propulsion Laboratory's (JPL) online HORIZONS system. The system has highly accurate ephemerides for asteroids and comets (612829 and 3,196 respectively on April 12, 2013) as well as other Solar System objects as well as orbital parameters and visualization tool for those objects. HORIZONS was used to build a database of all discovered comets up until February 8, 2013. The database includes: date discovered, date and close approach distance, inclination, eccentricity, total and nuclear magnitude, and several other observations used in the orbital fit. The data was then analyzed for characteristics using both MATLAB and Excel for analysis and numerical computations.

  3. Remote sensing of liquid characteristics using time domain reflectometry

    NASA Astrophysics Data System (ADS)

    Cataldo, Andrea; Lay-Ekuakille, Aime; De Carlo, Carlo

    2002-09-01

    Time domain reflectometry (TDR) instrumentation is widely used in hydrology and soil science for accurate and flexible soil water content measurements. The most attractive advantages concerning the considered TDR measurement system are: good precision and accuracy, high reliability of the measuring head, an unique approach of pulsing a long coaxial probe and analysing the reflected voltage signature caused by changes in impedance, capability of multiplexing several probes, possibility of remotely acceding, controlling and electronically retrieving and transmitting data through existing telecommunications. A time domain reflectometer transmits the incident signal, an ultra short rise time (200 ps), step voltage pulse, along the transmission line and records the travel time and magnitude of all reflected signals (echo) returning from the controlled system. Changes in capacitance, impedance, inductance and resistance causing electromagnetic discontinuities that reflect voltage can be located, particularly, for liquid level and soil dielectric properties monitoring purposes, discontinuities result from impedance changes produced by changes in the dielectric constant. Moreover, different systems are currently used to measure liquid levels in stocking tanks or vessels. The time domain reflectometry method used in this research has the purpose to monitor the behavior of the different liquid interfaces, detecting their levels. One of the the goals of present paper is to enhance field measurement capabilities; miniature pulsing and sampling cards have been used to create a smaller and more rugged time domain reflectometer, associated to the special steel probes working like a closed circuit radar, detecting any mismatch along the measuring lines. Measurements can be performed in a wide range of environmental conditions, independently from the nature or properties of the involved substances, giving information about their characteristics, such as volumetric content, dielectric constant, emulsions, dispersions, etc. Agreements with current TDR research data have been found. Furthermore, by characterizing several complex systems, the main objective of the present work is to develop an interpretation method based on the changes in the reflected TDR signal caused by the presence of hydrocarbons and their concentration in a soil.

  4. 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.

  5. 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.

  6. Long Characteristic Method in Space and Time for Transport Problems 

    E-print Network

    Pandya, Tara M.

    2010-07-14

    Discretization and solving of the transport equation has been an area of great research where many methods have been developed. Under the deterministic transport methods, the method of characteristics, MOC, is one such ...

  7. Characteristic Times for Collisions of Minor Bodies With Terrestrial Planets

    NASA Astrophysics Data System (ADS)

    Ipatov, S. I.; Ozernoy, L. M.

    2001-12-01

    Previous analytical calculations of characteristic times, T, for collisions of Earth-crossing objects (ECOs) and comets with the Earth were mainly based on Öpik's formulas. However, this approach becomes very inaccurate whenever the periods of a minor body and the planet are close to each other. While taking into account this situation, we also abandon the limitations of other approaches, which consider bodies moving in their orbots with an invariable velocity. When a minor body moving in an orbit with semimajor axis a collides with a planet at a distance r from the Sun, then T is larger by a factor of k = ? {2a/r -1} compared to the approximation of a constant velocity. The obtained values of T (in Myr) and k (in parenthesis) are presented in the following table. Atens & Apollos & Amors & ECOs & JFCs Venus & 106 (1.2) & 186 (1.7) & & 154 (1.5) & 2900 (2.5) Earth &15 (0.9) & 164 (1.4) & 211 (2.0) & 67 (1.1) &2200 (2.3) Mars &475 (0.4) & 4250 (0.9) &5810 (1.1)&4710 (1.0) &17000 (1.8) Note that relatively small values of T for Atens and all ECOs colliding with the Earth are due to just several Atens with small inclinations i, which were discovered during last two years. If for the Aten object having 0.1o one takes i=1o, then for collisions with Earth one gets 28 Myr for Atens and T=97 Myr for ECOs. For Jupiter-family comets (JFCs) colliding with the terrestrial planets, k>=2. For three Halley-type comets with periods between 71 and 76 yr, we obtained T=350 Gyr and k=6 (collision with Earth) and T=3500 Gyr and k=5 (collision with Mars). We have performed a series of runs of orbital evolution of resonant asteroids and JFCs and computed values of T for those runs. The results demonstrate that the effect of non-constant velocity must be taken into account, especially when semimajor axes of a minor body and a planet differ considerably. We acknowledge support of this work by NASA grant NAG5-10776, the RFP ``Astronomy", RFBR (01-02-17540), and INTAS (00-240).

  8. 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…

  9. Student part-time employment: characteristics and consequences

    Microsoft Academic Search

    David Robotham

    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 stress. Design\\/methodology\\/approach – The research consisted of an institution-wide

  10. Characteristic-Based Clustering for Time Series Data

    Microsoft Academic Search

    Xiaozhe Wang; Kate A. Smith; Rob J. Hyndman

    2006-01-01

    With the growing importance of time series clustering research, particularly for similarity searches amongst long time series such as those arising in medicine or finance, it is critical for us to find a way to resolve the outstanding problems that make most clustering methods impractical under certain circumstances. When the time series is very long, some clustering algorithms may fail

  11. EMBAYMENT CHARACTERISTIC TIME AND BIOLOGY VIA TIDAL PRISM MODEL

    EPA Science Inventory

    Transport time scales in water bodies are classically based on their physical and chemical aspects rather than on their ecological and biological character. The direct connection between a physical time scale and ecological effects has to be investigated in order to quantitativel...

  12. Spawning by California Golden Trout: Characteristics of Spawning Fish, Seasonal and Daily Timing, Redd Characteristics, and Microhabitat Preferences

    Microsoft Academic Search

    Roland A. Knapp; Vance T. Vredenburg

    1996-01-01

    We investigated the spawning biology of California golden trout Oncorhynchus mykiss aguabonita, an endemic subspecies of rainbow trout, in the Golden Trout Wilderness, California. We investigated the influence of stream temperature on the seasonal and daily timing of spawning, measured characteristics of completed redds, and quantified microhabitat use and preferences by spawning females. We also quantified size at sexual maturity,

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

    SciTech Connect

    Bennett, D.H.; McKone, T.E. [Univ. of California, Berkeley, CA (United States)] [Univ. of California, Berkeley, CA (United States); [Lawrence Berkeley National Lab., CA (United States); Kastenberg, W.E. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering] [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering

    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.

  14. Comparison of temperature time characteristics of two indirect moxibustion products.

    PubMed

    Lim, Jinwoong; Lee, Sanghoon; Kim, Hyunho; Park, Kyungmo

    2012-12-01

    The aim of this experiment was to investigate the thermal properties of a new indirect ceramic moxibustion (ICM) in comparison with conventional indirect stick moxibustion (ISM) and to interpret the clinical implications of the data. A thermocouple was installed underneath each moxibustion unit to record temperature, and 10 units were burned for each moxibustion trial. The procedure began when the unit temperature reached 27 ± 1°C and finished when the temperature had returned to 27°C. The maximum unit temperature, time to reach maximum temperature, and duration of combustion were measured for each moxibustion modality. The maximum temperatures for ISM and ICM were 62.5 ± 2.59°C and 50.2 ± 2.53°C, respectively. The times to reach maximum temperature for ISM and ICM were 5.6 and 16.8 minutes, respectively. The two modalities exhibit different thermal properties as ISM showed a higher maximum temperature (p < 0.0001), which can immediately cause third-degree burns, and a steeper slope of temperature change. ICM, however, showed a lower maximum temperature, more slowly reached the maximum temperature (p < 0.0001), and had a longer and stable duration of combustion. This study suggests that ISM and ICM have statistically different thermal properties, and ICM showed safer thermal properties and a more stable heating pattern. Randomized controlled trials involving various moxibustion modalities are required for further clinical evaluation. PMID:23265081

  15. Characteristics of the melatonin signal that provide the photoperiodic code for timing seasonal

    E-print Network

    Boyer, Edmond

    Characteristics of the melatonin signal that provide the photoperiodic code for timing seasonal the photoperiodic code for daylength in regulating seasonal breeding in the Suffolk ewe. The first series utilize daylength to time their seasonal reproductive cycle. Introduction. The importance of the pineal

  16. Characteristic Variations of Sea Surface Temperature with Multiple Time Scales in the North Pacific

    Microsoft Academic Search

    Youichi Tanimoto; Kimio Hanawa; Yoshiaki Toba; Naoto Iwasaka

    1993-01-01

    Temporal evolution and spectral structure of sea surface temperature (SST) anomalies in the North Pacific over the last 37 years are investigated on the three characteristic time scales: shorter than 24 months (HF), 24-60 months (ES), and longer than 60 months (DC). The leading empirical-orthogonal function (EOF) for the DC time scale is characterized by a zonally elongated monopole centered

  17. 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. [Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation)

    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.

  18. A parametric study of time-domain characteristics of possible UWB antenna architectures

    Microsoft Academic Search

    Stanislav Licul; Joseph A. N. Noronha; William A. Davis; Dennis G. Sweeney; Christopher R. Anderson; T. M. Bielawa

    2003-01-01

    This paper is a step toward defining the characteristics of a suitable antenna to exploit the inherent advantages in pulsed communication systems, specifically that of ultra-wideband. In this respect, several traditional broadband antenna architectures are evaluated with an emphasis given towards a time-domain perspective. In addition, a good UWB antenna should be reasonably efficient over the entire frequency band allocated

  19. 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…

  20. Time reversal and Hermiticity characteristics of polarizability and optical activity operators

    Microsoft Academic Search

    Lutz Hecht; Laurence D. Barron

    1993-01-01

    Exact non-singular effective polarizability operators are introduced that exhibit well defined time reversal and Hermiticity characteristics and can therefore be applied to all forms of (optically active) light scattering including resonance phenomena. Dual circular polarization (DCP) and dual linear polarization (DLP) Raman optical activity (ROA) observables are reformulated in terms of matrix elements of these generalized scattering operators. Employing the

  1. Far-Infrared Characteristics of ZnS Nanoparticles Measured by Terahertz Time-Domain Spectroscopy

    E-print Network

    ARTICLES Far-Infrared Characteristics of ZnS Nanoparticles Measured by Terahertz Time Form: December 3, 2005 The optical and dielectric properties of ZnS nanoparticles are studied by use.6 ( 0.2 THz. Meanwhile, the low-frequency phonon resonance of ZnS nanoparticles is compared

  2. The Relationship Between Gun and Gun Buyer Characteristics and Firearm Time-to-Crime

    Microsoft Academic Search

    Steven G. Brandl; Meghan S. Stroshine

    2011-01-01

    Gun violence continues to be a major crime control problem in many metropolitan cities in America. To comprehend this problem more completely, this study seeks to develop an understanding of the dynamics of illegal firearm markets in one particular city: Milwaukee, Wisconsin. In particular, the characteristics of guns and gun buyers that are related to fast firearm time-to-crime are identified.

  3. Evaluation Of Displacement-time Characteristics Of Stirling Engine Drive Mechanisms

    Microsoft Academic Search

    T. V. Adinarayan; M. V. Narasimhan

    1990-01-01

    Mechanical efficiency is the single most important factor in the successful development of Stirling prime movers. The ideal displacement time characteristics of the Stirling cycle underlines the crucial role of the mechanical configuration. The relative merits of the mechanical configurations tried out so far in Stirling prime movers is critically examined in the present paper. Dead volume is not considered

  4. r Human Brain Mapping 30:34453460 (2009) r Time-Varied Characteristics of Acupuncture

    E-print Network

    Tian, Jie

    2009-01-01

    r Human Brain Mapping 30:3445­3460 (2009) r Time-Varied Characteristics of Acupuncture Effects in f, Gainesville, Florida r r Abstract: When studying the neural responses to acupuncture with a block associ- ating its psychophysiological response, numerous clinical reports suggest that acupuncture can

  5. The Development of a Portable Real-Time Display of Voice Source Characteristics

    Microsoft Academic Search

    S. V. Batty; Paul E. Garner; David M. Howard; P. Turner; A. D. White

    2000-01-01

    The use of real time visual displays by speech and language therapists for the representation of voice source characteristics such as fundamental frequency (F0) and electrolaryngographically (Lx) derived vocal fold closed quotient (CQ) is now well established. This trend has been made possible by the widespread availability of fast computers and dedicated signal processing devices. However, many users of such

  6. Iterative approach to the characteristic time for chemical reactions of type A + B ! C + D

    E-print Network

    R. Aldrovandi

    2013-10-13

    The analytic solution for the kinetic description of binary reactions can be seen as the continuum version of a basic discrete iterate mapping. This fact allows a clear definition of the reaction characteristic time which takes the backward effect into account.

  7. Iterative approach to the characteristic time for chemical reactions of type A + B ! C + D

    E-print Network

    Aldrovandi, R

    2013-01-01

    The analytic solution for the kinetic description of binary reactions can be seen as the continuum version of a basic discrete iterate mapping. This fact allows a clear definition of the reaction characteristic time which takes the backward effect into account.

  8. 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 ?m 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 ?s.

  9. The Camberwell Cohort 25 Years On: Characteristics and Changes in Skills over Time

    ERIC Educational Resources Information Center

    Beadle-Brown, Julie; Murphy, Glynis; Wing, Lorna

    2006-01-01

    Background: This study presents data on the characteristics of the Camberwell Cohort, 25 years after they were first assessed in the 1970s [Wing & Gould (1979) "Journal of Autism and Childhood Schizophrenia" vol. 9, pp. 11-29]. It also presents data on changes over time which adds to that presented in Beadle-Brown et al. ["Journal of Intellectual…

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

    PubMed Central

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

    2014-01-01

    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. PMID:25189200

  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

    2014-01-01

    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. PMID:25189200

  12. 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.

  13. The relationship among college science student achievement, engaged time, and personal characteristics

    NASA Astrophysics Data System (ADS)

    Johnson, T. Franklin; Butts, David P.

    The relationships among college student science achievement, engaged time (observed and perceived), and personal characteristics of academic aptitude, reasoning ability, attitude toward science, and locus of control were investigated. Measures of personal characteristics were obtained from the subjects (N= 76) of a private, liberal arts junior college before observations began in the lecture classes for the quarter. Instruments used to measure personal characteristics were Scholastic Aptitude Test, Test of Logical Thinking, Test of Scientific Attitude, and Leven-son's Multidimensional View of Locus of Control. Based on a random selection procedure, student engaged time was observed at least ten times for 11 lectures. Achievement tests were constructed and validated for the biology classes. Data were analyzed by multiple regression procedures. The average achievement scores were positively related to academic aptitude and reasoning ability. Positive relationships were found between observed engaged time and academic aptitude and a negative relationship was found between observed engaged time and reasoning ability. Also a positive relationship was found between perceived engaged time and achievement. Pearson product-moment correlations between achievement and observed engaged time were significant as were the correlations between perceived engaged time and achievement. Measure of engaged time (observed and perceived) were also related to each other. The study's data indicate that students who were observed to be engaged were low in reasoning ability or high in academic aptitude. Those who perceived themselves as being engaged achieved more. College instructors who have knowledge of student academic aptitude and reasoning ability may use this knowledge to improve achievement.Engaged time measures were significantly related to achievement, which indicates an instructor should endeavor to keep the students as engaged as possible to enhance achievement. Students who are engaged or pay attention or perceived they are engaged or paying attention during lecture classes achieve more than students who are observed as nonengaged or perceive themselves as nonengaged.

  14. 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.

  15. 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.

  16. 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 8min 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. PMID:26041200

  17. Time-dependent behaviour of high performance concrete: influence of coarse aggregate characteristics

    NASA Astrophysics Data System (ADS)

    Makani, A.; Vidal, T.; Pons, G.; Escadeillas, G.

    2010-06-01

    This paper examines the influence of coarse aggregate characteristics on the time-dependent deformations of High Performances Concretes (HPC). Four concretes made using the same cement paste but incorporating different types of aggregate (rolled siliceous gravel, crushed granite, crushed limestone and crushed siliceous gravels) were studied in order to investigate the effect of aggregate properties on the compressive strength, modulus of elasticity, shrinkage and creep. The results indicate that the aggregate type has a significant effect on creep and shrinkage deformations of HPC. An influence of the shape of aggregate on time-dependent deformations has also been observed. On the basis of these results, long-term behaviour seems to be correlated to the characteristics of the Interfacial Transition Zone (ITZ) strongly depending on the mineralogical nature and properties of aggregates. The experimental results are compared with the values calculated using the current Eurocode 2 model in order to assess the accuracy of the predictions.

  18. Baroreflex contribution to blood pressure and heart rate oscillations: time scales, time-variant characteristics and nonlinearities.

    PubMed

    Di Rienzo, M; Parati, G; Radaelli, A; Castiglioni, P

    2009-04-13

    The aim of this paper is to highlight the aspects of the baroreflex control of the cardiovascular system that could be relevant to the analysis and modelling of cardiovascular oscillations and regulation. In particular, complex and/or controversial issues of the baroreflex control are addressed on the basis of results obtained in previous studies by others as well as by our group. Attention has been focused on time-variant and nonlinear characteristics of the baroreflex function and on the influence of this physiological mechanism on different frequency regions of blood pressure and heart rate spectra. PMID:19324710

  19. Uniqueness results for ill posed characteristic problems in curved space-times

    E-print Network

    Alexandru D. Ionescu; Sergiu Klainerman

    2008-07-26

    We prove two uniqueness theorems for solutions of linear and nonlinear wave equations; the first theorem is in the Minkowski space while the second is in the domain of outer communication of a Kerr black hole. Both theorems concern ill posed Cauchy problems on smooth, bifurcate, characteristic hypersurfaces. In the case of the Kerr space-time this hypersurface is the event horizon of the black hole.

  20. Optical activity operators with ill defined time reversal and Hermiticity characteristics

    Microsoft Academic Search

    Lutz Hecht; Laurence D. Barron

    1993-01-01

    Our earlier work on non-singular effective polarizability and optical activity operators is generalized to remove the condition of well defined time reversal and Hermiticity characteristics of the optical activity operators. This enables depolarized right-angle incident (ICP) and scattered circular polarization (SCP) and polarized right-angle incident (ILP) and scattered linear polarization (SLP) Raman optical activity (ROA) observables to be formulated in

  1. Determining the optimal holding time at solutioning temperature from the structural characteristics of aluminum alloy castings

    Microsoft Academic Search

    V. S. Zolotorevskii; V. V. Teleshov

    1970-01-01

    1.For alloys AL8 and AL19 we obtained simple equations permitting fairly precise determination of the optimal holding time from the average thickness of the inclusions of excess phase in castings.2.We found a quantitative relationship between the cooling rate during solidification and the structural characteristics of AL8 castings.3.On the basis of data for AL8 alloys, we showed the possibility of obtaining

  2. [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-). PMID:21780572

  3. The characteristic time scale for basin hydrological response using radar data

    NASA Astrophysics Data System (ADS)

    Morin, Efrat; Enzel, Yehouda; Shamir, Uri; Garti, Rami

    2001-10-01

    The transformation of rainfall into runoff at a basin outlet is the combined effect of many hydrological processes, which occur at a wide range of spatial and temporal scales. However, determining the scale of the combined hydrological response of the basin is still problematic and concepts for its definition are yet to be identified. In this paper high-resolution meteorological radar data are used for the determination of a characteristic temporal scale for the hydrological response of the basin — the 'response time scale' (T s?). T s? is defined as the time scale at which the pattern of the time-averaged radar rainfall hietograph is most similar to the pattern of the measured outlet runoff hydrograph. The existence of such similarity at a relatively stable time scale for a specific basin indicates that it is an intrinsic property of the basin and is related to its hydrological response. The identification of the response time scale is carried out by analysis of observations only, without assuming a specific rainfall-runoff model. T s? is examined in four small basins (10-100 km 2) in Israel. The spatial scale is assumed as the entire basin. For all analyzed basins a stable response time scale is identified. Relatively short time scales are found for the urban and arid basins (15-30 min), while for the rural basins longer time scale are identified (90-180 min). The issues of relationship between the response time scale and basin properties and modeling at the response time scale have yet to be determined.

  4. Characteristic Evaluation of Synchronous Motors Using an Universal Drive System with a Real-Time Interface

    NASA Astrophysics Data System (ADS)

    Amano, Yoko; Ogasawara, Satoshi

    In this paper, a new universal drive system of synchronous motors used Real-Time Interface (RTI) performs characteristic evaluation of Synchronous Reluctance (SynR) motors and Surface Permanent Magnet (SPM) synchronous motors. The RTI connects directly a simulation model with experimental equipment, and makes it possible to use the simulation model for an experiment. The RTI is very effective in the early detection of an actual problem and examination of solution technique. Moreover, it concentrates on examination of control algorithm, and efficient research and development are enabled. A measuring system of synchronous motors is built by the universal drive system. The examination of various synchronous motors is possible for the measurement system using the same control algorithm. Characteristic evaluation of a SynR motor and a SPM synchronous motor that are the same gap length and stator was performed using the measuring system. The measurement result shows experimentally that motor loss of the SynR motor is smaller rather than the SPM synchronous motor, at the time of high speed and low load operation. For example, the SynR motor is suitable to hybrid cars with the comparatively long time of low load and high-speed operation.

  5. Optically controlled characteristics of III–V Nitride based MM-wave transit-time devices

    Microsoft Academic Search

    Moumita Mukherjee

    2009-01-01

    Extensive simulation experiments are carried out for the first time, to study the photo-irradiation effects on the high frequency characteristics of III-V GaN (Gallium Nitride) based Top-Mounted and Flip-Chip IMPATT oscillators at MM-wave window frequency (140.0 GHz). MM-wave properties of un-illuminated GaN IMPATTs are compared with those of conventional Si, GaAs and InP IMPATTs, under similar operating conditions. Superiority of

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

    SciTech Connect

    Talamo, Alberto, E-mail: alby@anl.gov [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States)] [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States)

    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.

  7. Spatial and temporal characteristics of transient anomalies on cGPS time series in Taiwan

    NASA Astrophysics Data System (ADS)

    Kuanhsiang Chen, Sean; Hsu, Ya-Ju; Wu, Yih-Min; Chan, Yu-Chang

    2015-04-01

    Transient anomaly on geodetic time series is a key constraint to understand physical behavior and mechanism of natural hazards. We first identify overall transient anomalies in Taiwan recorded by continuous GPS (cGPS) networks. Sparse estimation techniques is applied to estimate quantity of transient signals from cGPS time series. Systematic classification on transients for isolating each signal is established by weighting empirical trigger factors and criterion. Spatial and temporal characteristics of transient anomalies show contribution of seismic events, landslides, and slow slips. Seismic-related transients are sensitive to earthquakes on land (Mw > 5.5) in particular shallow source depths. Landslide-related transients in the Central Range are induced by typhoons and episodic heavy rainfalls. Slow-slip transients show remote triggering of surrounding great earthquakes. Preliminary linking between geodetic transient signals and natural hazards of Taiwan is well described. Unknown transients reveal surface and tectonic process may play important role in crustal deformation.

  8. 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.

  9. 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.

  10. A variable-order time-dependent neutron transport method for nuclear reactor kinetics using analytically-integrated space-time characteristics

    SciTech Connect

    Hoffman, A. J.; Lee, J. C. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI, 48109-2104 (United States)

    2013-07-01

    A new time-dependent neutron transport method based on the method of characteristics (MOC) has been developed. Whereas most spatial kinetics methods treat time dependence through temporal discretization, this new method treats time dependence by defining the characteristics to span space and time. In this implementation regions are defined in space-time where the thickness of the region in time fulfills an analogous role to the time step in discretized methods. The time dependence of the local source is approximated using a truncated Taylor series expansion with high order derivatives approximated using backward differences, permitting the solution of the resulting space-time characteristic equation. To avoid a drastic increase in computational expense and memory requirements due to solving many discrete characteristics in the space-time planes, the temporal variation of the boundary source is similarly approximated. This allows the characteristics in the space-time plane to be represented analytically rather than discretely, resulting in an algorithm comparable in implementation and expense to one that arises from conventional time integration techniques. Furthermore, by defining the boundary flux time derivative in terms of the preceding local source time derivative and boundary flux time derivative, the need to store angularly-dependent data is avoided without approximating the angular dependence of the angular flux time derivative. The accuracy of this method is assessed through implementation in the neutron transport code DeCART. The method is employed with variable-order local source representation to model a TWIGL transient. The results demonstrate that this method is accurate and more efficient than the discretized method. (authors)

  11. Effect of nitrogen source, rate and time of application on soil nitrogen status and on the characteristics of the plant 

    E-print Network

    Sadik, Mohamed Kamal

    1962-01-01

    EFFECT OF NITROGEN SOURCE, RATE AND TIME OF APPLICATION ON SOIL NITROGEN STATUS AND ON THE CHARACTERISTICS OF THE PLANT By Mohamed K. Sadik A Thesis Submitted to the Graduate School of the Agricultural and Mechanical College of Texxas... in partial, fulfillment of the requirements for the degree of MASTER OF SCIENCE Major Subject: Soil and Plant Sciences May, 1962 EFFECT F NITROGEN SOURCE, RATE AND TIME OF APPLICATION ON SOIL NITROGEN STATUS AND ON THE CHARACTERISTICS OF THE PI ANT' A...

  12. Time trends in the Characteristics of Patients Undergoing Primary Total Knee Arthroplasty

    PubMed Central

    Singh, Jasvinder A.; Lewallen, David G.

    2014-01-01

    Objective To study the time-trends in socio-demographic and clinical characteristics of patients undergoing primary total knee arthroplasty (TKA). Methods We used the Mayo Clinic Total Joint Registry to examine the time-trends in patient demographics (body mass index [BMI], age), underlying diagnosis, medical (Deyo-Charlson index) and psychological comorbidity (anxiety, depression) and examination findings of primary TKA patients from 1993–2005. We used chi-square test and analysis of variance. Results 7,229 patients constituted the primary TKA cohort; 55% were women. The mean age decreased by 1.3 years (69.3 to 68.0), BMI increased by 1.7 kg/m2 (30.1 to 31.8) and Deyo-Charlson index increased by 36% (1.1 to 1.5) over the 13-year study period (p<0.001 for all). Compared to 1993–95, significantly more patients (by 2–3 times) in 2002–05 had (p<0.001 for all): BMI ?40, 4.8% vs. 10.6%; age <50, 2.9% vs. 5.2%; Deyo-Charlson index of ?3, 12% vs. 22.3%; depression, 4.1% vs. 14.8%; anxiety, 4.1% vs. 8.9%; and a significantly fewer had an underlying diagnosis of rheumatoid/inflammatory arthritis, 6.4% vs. 1.5%. Compared to 1993–95, significant reductions were noted in 2002–05 for the physical examination findings of (p<0.001 for all): knee joint effusion, anterior-posterior knee instability, medial-lateral knee instability, moderate-severe knee synovitis, severe limp, fair or poor muscle strength and absent peripheral pulses. Conclusions In this large U.S. total joint registry study, we found significant time-trends in patient characteristics, diagnosis, comorbidity and knee/limb examination findings in primary TKA patients over 13-years. These secular trends should be taken into account when comparing outcomes over time and in policy-making decisions. PMID:24249702

  13. [Sensing characteristics of a real-time monitor using a photoionization detector on organic solvent vapors].

    PubMed

    Hori, Hajime; Ishematsu, Sumiyo; Fueta, Yukiko; Hinoue, Mitsuo; Ishidao, Toru

    2012-12-01

    Measurements of organic solvents in the work environment are carried out by either direct sampling using plastic bags/gas chromatography, solid sorbent adsorption using charcoal tubes/gas chromatography, or by a direct reading method using detector tubes. However, these methods cannot always measure the work environment accurately because the concentration of hazardous materials changes from time to time, and from space to space. In this study, the sensor characteristics of a real time monitor using a photoionization detector that can monitor vapor concentration continuously were investigated for 52 organic solvent vapors that are required to be measured in the work environment by the Ordinance of Organic Solvent Poisoning Prevention in Japan. The sensitivity of the monitor was high for the solvents with low ionization potential. However, the sensitivity for the solvents with high ionization potential was low, and the sensor could not detected 7 solvents. Calibration of the sensor using a standard gas was desirable before being used for measurement because the sensitivity of the sensor was variable. PMID:23270260

  14. CCMR: Quantifying the Relationship Between Nanofiber Web Pore Characteristics and Electrospinning Time

    NSDL National Science Digital Library

    Luginbuhl, Kelli M.

    2010-08-15

    Nonwoven, electrospun nanofibers have enjoyed increased research attention for many of their unique electrical, optical and mechanical properties; high surface to volume ratio; and ability to be designed to display a desired surface charge. In order to aid future research involving filtration and particle detection, the goal of this study was to quantify pore characteristics of polyvinyl alcohol (PVA) fabrics spun for low times. The two methods used were capillary flow porometry and scanning electron microscope image analysis. 8, 10 and 12 w% solutions of PVA with maleic anhydride (MA) and Polybrene additives for surface charge were spun at 0.01 mL/min with a 15 cm collecting distance and an applied charge of 12kV. The 10 w% for both solutions had better spinnability and fiber uniformity, although the PVA/MA had significantly greater fiber diameter uniformity over the PVA/Polybrene solution. The porometer returned a range of 30.9 ?m to 3.3 ?m and the image analysis a range of about 6 ?m to 1 ?m from 5 seconds to 5 minutes. Although capillary flow porometry cannot measure porosity, SEM image analysis found that the porosity of both solutions was reduced from 80% at 5 seconds to only 28% at 5 minutes. The uniformity of pores became apparent with roughly 1 minute of spinning time and increased with times greater than 1 minute.

  15. 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.

  16. Flow characteristics of a pilot-scale high temperature, short time pasteurizer.

    PubMed

    Tomasula, P M; Kozempel, M F

    2004-09-01

    In this study, we present a method for determining the fastest moving particle (FMP) and residence time distribution (RTD) in a pilot-scale high temperature, short time (HTST) pasteurizer to ensure that laboratory or pilot-scale HTST apparatus meets the Pasteurized Milk Ordinance standards for pasteurization of milk and can be used for obtaining thermal inactivation data. The overall dimensions of the plate in the pasteurizer were 75 x 115 mm, with a thickness of 0.5 mm and effective diameter of 3.0 mm. The pasteurizer was equipped with nominal 21.5- and 52.2-s hold tubes, and flow capacity was variable from 0 to 20 L/h. Tracer studies were used to determine FMP times and RTD data to establish flow characteristics. Using brine milk as tracer, the FMP time for the short holding section was 18.6 s and for the long holding section was 36 s at 72 degrees C, compared with the nominal times of 21.5 and 52.2 s, respectively. The RTD study indicates that the short hold section was 45% back mixed and 55% plug flow for whole milk at 72 degrees C. The long hold section was 91% plug and 9% back mixed for whole milk at 72 degrees C. This study demonstrates that continuous laboratory and pilot-scale pasteurizers may be used to study inactivation of microorganisms only if the flow conditions in the holding tube are established for comparison with commercial HTST systems. PMID:15375033

  17. 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. PMID:23287835

  18. Experimental investigation on channel characteristics in tunnel environment for Time Reversal Ultra Wide Band techniques

    NASA Astrophysics Data System (ADS)

    Garcia-Pardo, Concepcion; Lienard, Martine; Degauque, Pierre; Molina-Garcia-Pardo, Jose-Maria; Juan-LláCer, Leandro

    2012-02-01

    The objective of this paper is to investigate the potential advantages of the Time Reversal (TR) technique applied to Impulse Radio Ultra Wide Band (UWB) signals for communications in tunnels. Indeed, in an environment with significant multipaths, it has already been outlined that this technique allows mitigating intersymbol interference and increases the peak power received at a target antenna. However, in a tunnel, as a result of the guiding effect of the structure, the spatial diversity degree decreases as the distance between the transmitter and receiver increases. An in-depth analysis is therefore needed, and we first thus present the main characteristics of the UWB channel deduced from measurements made in a long straight arched tunnel and for a frequency band extending from 2.8 to 5 GHz. In the time domain, waveforms of the impulse radio signal are obtained through an inverse Fourier transform of the measured frequency response and examples are given for different distances varying from 50 m to 500 m. Delay spread and peak-to-peak gain are then studied, depending on the communication range. The case for multiple antenna transmission is also considered.

  19. Escape times for rigid Brownian rotators in a bistable potential from the time evolution of the Green function and the characteristic time of the probability evolution

    NASA Astrophysics Data System (ADS)

    Coffey, W. T.; Crothers, D. S. F.; Titov, S. V.

    2001-09-01

    The greatest relaxation time for an assembly of three-dimensional rigid rotators in an axially symmetric bistable potential is obtained exactly in terms of continued fractions as a sum of the zero frequency decay functions (averages of the Legendre polynomials) of the system. This is accomplished by studying the entire time evolution of the Green function (transition probability) by expanding the time dependent distribution as a Fourier series and proceeding to the zero frequency limit of the Laplace transform of that distribution. The procedure is entirely analogous to the calculation of the characteristic time of the probability evolution (the integral of the configuration space probability density function with respect to the position co-ordinate) for a particle undergoing translational diffusion in a potential; a concept originally used by Malakhov and Pankratov (Physica A 229 (1996) 109). This procedure allowed them to obtain exact solutions of the Kramers one-dimensional translational escape rate problem for piecewise parabolic potentials. The solution was accomplished by posing the problem in terms of the appropriate Sturm-Liouville equation which could be solved in terms of the parabolic cylinder functions. The method (as applied to rotational problems and posed in terms of recurrence relations for the decay functions, i.e., the Brinkman approach c.f. Blomberg, Physica A 86 (1977) 49, as opposed to the Sturm-Liouville one) demonstrates clearly that the greatest relaxation time unlike the integral relaxation time which is governed by a single decay function (albeit coupled to all the others in non-linear fashion via the underlying recurrence relation) is governed by a sum of decay functions. The method is easily generalized to multidimensional state spaces by matrix continued fraction methods allowing one to treat non-axially symmetric potentials, where the distribution function is governed by two state variables.

  20. Characteristics of Four SPE Classes According to Onset Timing and Proton Acceleration Patterns

    NASA Astrophysics Data System (ADS)

    Kim, Roksoon

    2015-04-01

    In our previous work (Kim et al., 2015), we suggested a new classification scheme, which categorizes the SPEs into four groups based on association with flare or CME inferred from onset timings as well as proton acceleration patterns using multienergy observations. In this study, we have tried to find whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (> 5000 pfu) even if the associated flare and CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. For the former, the sites are very low ( ~1 Rs) and close to the western limb, while the latter has a relatively higher (mean=6.05 Rs) and wider acceleration sites. (ii) When the proton acceleration starts from the higher energy, a SPE tends to be a relatively weak event (< 1000 pfu), in spite of its associated CME is relatively stronger than previous group. (iii) The SPEs categorized by the simultaneous proton acceleration in whole energy range within 10 minutes, tend to show the weakest proton flux (mean=327 pfu) in spite of strong related eruptions. Their acceleration heights are very close to the locations of type II radio bursts. Based on those results, we suggest that the different characteristics of the four groups are mainly due to the different mechanisms governing the acceleration pattern and interval, and different condition such as the acceleration location.

  1. Temporal direct numerical simulation of transitional natural-convection boundary layer under conditions of considerable external turbulence effects

    NASA Astrophysics Data System (ADS)

    Abramov, Alexey G.; Smirnov, Evgueni M.; Goryachev, Valery D.

    2014-08-01

    Results of direct numerical simulations for time-developing air natural-convection boundary layer are presented. Computations have been performed assuming periodicity conditions in both the directions parallel to the vertical isothermal hot plate. The contribution is mainly focused on understanding of laminar-turbulent transition peculiarities in the case of perturbation action of external turbulence that is modeled by isotropic disturbances initially introduced into the computational domain. Special attention is paid to identification and analysis of evolving three-dimensional vortices that clearly manifest themselves through the whole stages of laminar-turbulent transition in the boundary layer. A comparison of computed profiles of mean velocity, mean temperature and fluctuation characteristics for turbulent regimes of convection with experimental data is performed as well.

  2. Characteristics of first-time fathers of advanced age: a Norwegian population-based study

    PubMed Central

    2013-01-01

    Background The modern phenomenon of delayed parenthood applies not only to women but also to men, but less is known about what characterises men who are expecting their first child at an advanced age. This study investigates the sociodemographic characteristics, health behaviour, health problems, social relationships and timing of pregnancy in older first-time fathers. Methods A cross-sectional study was conducted of 14 832 men who were expecting their first child, based on data from the Norwegian Mother and Child Cohort Study (MoBa) carried out by the Norwegian Institute of Public Health. Data were collected in 2005–2008 by means of a questionnaire in gestational week 17–18 of their partner’s pregnancy, and from the Norwegian Medical Birth Register. The distribution of background variables was investigated across the age span of 25 years and above. Men of advanced age (35–39 years) and very advanced age (40 years or more) were compared with men aged 25–34 years by means of bivariate and multivariate logistic regression analyses. Results The following factors were found to be associated with having the first child at an advanced or very advanced age: being unmarried or non-cohabitant, negative health behaviour (overweight, obesity, smoking, frequent alcohol intake), physical and mental health problems (lower back pain, cardiovascular diseases, high blood pressure, sleeping problems, previous depressive symptoms), few social contacts and dissatisfaction with partner relationship. There were mixed associations for socioeconomic status: several proxy measures of high socioeconomic status (e.g. income >65 000 €, self-employment) were associated with having the first child at an advanced or very advanced age, as were several other proxy measures of low socioeconomic status (e.g. unemployment, low level of education, immigrant background).The odds of the child being conceived after in vitro fertilisation were threefold in men aged 34–39 and fourfold from 40 years and above. Conclusions Men who expect their first baby at an advanced or very advanced age constitute a socioeconomically heterogeneous group with more health problems and more risky health behaviour than younger men. Since older men often have their first child with a woman of advanced age, in whom similar characteristics have been reported, their combined risk of adverse perinatal outcomes needs further attention by clinicians and researchers. PMID:23363654

  3. Effect of turnoff time on characteristics of the output pulse in an AO Q-switched laser

    Microsoft Academic Search

    Wenchao Qiao; Shengzhi Zhao; Guiqiu Li; Kejian Yang; Ming Li; Jing An; Jing Wang

    2009-01-01

    A laser-end-diode-pumped actively Q-switched Nd:YVO4 laser with acoustic-optic (AO) modulator is realized. By changing the position of AO in the cavity for changing the transit time of the acoustic-wave, the effect of the AO turnoff time on the characteristics of the output Q-switched pulse is obtained. The experimental results show that the longer transit time leads to the wider pulse

  4. Effect of various loads on the force-time characteristics of the hang high pull.

    PubMed

    Suchomel, Timothy J; Beckham, George K; Wright, Glenn A

    2015-05-01

    The purpose of this study was to investigate the effect of various loads on the force-time characteristics associated with peak power during the hang high pull (HHP). Fourteen athletic men (age: 21.6 ± 1.3 years; height: 179.3 ± 5.6 cm; body mass: 81.5 ± 8.7 kg; 1 repetition maximum [1RM] hang power clean [HPC]: 104.9 ± 15.1 kg) performed sets of the HHP at 30, 45, 65, and 80% of their 1RM HPC. Peak force, peak velocity, peak power, force at peak power, and velocity at peak power were compared between loads. Statistical differences in peak force (p = 0.001), peak velocity (p < 0.001), peak power (p = 0.015), force at peak power (p < 0.001), and velocity at peak power (p < 0.001) existed, with the greatest values for each variable occurring at 80, 30, 45, 80, and 30% 1RM HPC, respectively. Effect sizes between loads indicated that larger differences in velocity at peak power existed as compared with those displayed by force at peak power. It seems that differences in velocity may contribute to a greater extent to differences in peak power production as compared with force during the HHP. Further investigation of both force and velocity at peak power during weightlifting variations is necessary to provide insight on the contributing factors of power production. Specific load ranges should be prescribed to optimally train the variables associated with power development during the HHP. PMID:25426514

  5. Power spectrum characteristics of body sway time series and velocity time series of the center of foot pressure during a static upright posture in preschool children

    Microsoft Academic Search

    S. Demura; T. Kitabayashi

    2008-01-01

    This study aimed to assess individual and gender differences in power spectra in the body sway time series and sway velocity\\u000a time series during a static upright standing posture using 30 preschool children and their spectrum distribution characteristics.\\u000a The center of pressure (COP) movement for 1 min was measured twice with a 1 min rest on an Anima stabilometer. The

  6. Maternal selenium supplementation and timing of nutrient restriction in pregnant sheep: Impacts on maternal endocrine status and placental characteristics.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to determine the effects of dietary selenium and nutrient restriction (level and timing) on serum hormone and metabolite levels and placental characteristics in mid- to late-pregnancy ewes. Pregnant ewe lambs (n = 64) were assigned to 1 of 8 treatments arranged in a 2 x 2 x 2 facto...

  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 California ISO load following and regulation requirements into the future • Value of fast responsive resources depending on their ramping capability • Potential impacts of the balancing authority area control error limit (BAAL), which is a part of the newly proposed NERC standard “Balancing Resources and Demand” • Potential impacts of the Western Electricity Coordinating Council (WECC) frequency responsive reserve (FRR) standard • Recommendations for the next phase of the project. The following main conclusions and suggestions for the future have been made: • The analysis of regulation ramping requirements shows that the regulation system should be able to provide ramps of at least 40-60 MW per minute for a period up to 6 minutes. • Evaluate if changes are needed in the California ISO AGC system to effectively accommodate new types of fast regulation resources and minimize the California ISO regulation procurement. • California ISO may consider creating better market opportunities for and incentives for fast responsive resources. • An additional study of low probability high ramp events can be recommended to the California ISO. • The California ISO may be willing to consider establishing a more relaxed target CPS2 compliance level. • A BAAL-related study can be recommended for the California ISO as soon as more clarity is achieved concerning the actual enforcement of the BAAL standard and its numerical values for the California ISO. The study may involve an assessment of advantages of the distributed frequency-based control for the California ISO system. The market-related issues that arise in this connection can be also investigated. • A FRR-related study can be recommended for the California ISO as soon as more clarity is achieved concerning the actual enforcement of the FRR standard and its numerical values for the California ISO.

  8. Study of the time-frequency characteristics of continuous gravity data sequence

    NASA Astrophysics Data System (ADS)

    Weimin, X.; Shi, C.; Lei, S.; Hongyan, L.

    2013-12-01

    The continuous gravity measurements contained much valuable signal which was maybe caused by internal and external change of the Earth, which offered abundant information to study activities of the Earth. In the past decades, researchers mostly focused on discussing the relationship between the gravity variation and geodynamical processes. Here we studied the temporal variation of the gravity field through the continuous gravity records. Our goal was to detect certain geophysical signal on the order of a few tens of micro-Gal from the gravity data sequence. The gravity data sequences were recorded by the Scintrex g-Phone relative gravimeters those were located at the numerous observation stations of mainland China which had well-controlled observation systems. We presented a two-step procedure to study the signal of gravity variation. Firstly, we developed a Linear Similarity filtering technique which could reduce the drift of gravity instrument effectively by using two relative gravimeters at the same station by the reason of the short-term liner drift feature of gravimeters. Based on the method above, we gained non-tidal gravity variation more accurate that contained much geophysical signal which was associated with geodynamical phenomena. Secondly, we employed the time-frequency analysis techniques to analyze the feature of different temporal variation signal and tried to find some periodic and non-periodic characteristics of the continuous gravity data sequence. Moreover, we compared the results to the mobile repeated gravity measurements on ground and acquired the spatial and temporal gravity variation at last. We also expected to find some anomaly signal related to the activities of tectogenesis and fault movement prior to the destructive earthquakes from the continuous gravity data sequence. Acknowledgment: We acknowledge the financial support of the Basic Scientific Research Foundation of Institute of Geophysics CEA (DQJB12B20, DQJB12C03 and DQJB12B14), the Scientific and Technological Support Foundation of CEA (2012BAK19B01-05-02) and the National Natural Science Foundation of China (41104046).

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

    SciTech Connect

    Paeng, Dongwoo; Grigoropoulos, Costas P., E-mail: cgrigoro@berkeley.edu [Department of Mechanical Engineering, University of California Berkeley, Berkeley, California 94720-1740 (United States); Lee, Daeho [Department of Mechanical Engineering, Gachon University, Seongnam-si, Gyeonggi-do 461-701 (Korea, Republic of)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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.

  11. First Time: Characteristics of Teens' First Sexual Relationships. Child Trends Research Brief.

    ERIC Educational Resources Information Center

    Ryan, Suzanne; Manlove, Jennifer; Franzetta, Kerry

    Understanding characteristics of teens' sexual relationships may help us to better understand how to reduce teens' risk of early unintended pregnancy and sexually transmitted diseases (STDs), as well as the psychological and emotional problems that may be associated with teenage romantic relationships and sexual activity. Using data from the…

  12. Spending Time with Teacher: Characteristics of Preschoolers Who Frequently Elicit versus Initiate Interactions with Teachers.

    ERIC Educational Resources Information Center

    Coplan, Robert J.; Prakash, Kavita

    2003-01-01

    Explored interface between preschoolers' socio-emotional characteristics and interactions with teachers during free play. Found that children who most frequently initiated teacher interaction behaved more aggressively than peers and were so rated by teachers. Children who most frequently received teacher initiations were more shy and anxious.…

  13. Quiet time solar illumination effects on the fluxes and characteristic energies of ionospheric outflow

    Microsoft Academic Search

    W. K. Peterson; H. L. Collin; O. W. Lennartsson; A. W. Yau

    2006-01-01

    We report on the characteristic energy, intensity, and flow rate of escaping ionospheric ions as a function of solar illumination. The data presented here were acquired with the Toroidal Ion Mass-Angle Spectrograph (TIMAS) instrument on the Polar satellite at altitudes of 6000 to 9000 km, during solar minimum. To obtain uniform coverage under various solar illumination conditions, data were restricted

  14. Time Course and Characteristics of Symptom Distress and Quality of Life at the End of Life

    Microsoft Academic Search

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

    2007-01-01

    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 ¼ 86), their nurses (n ¼ 86), and family caregivers (n ¼ 49) from 11 hospice\\/ palliative care organizations completed the Memorial Symptom Assessment Scale (MSAS) and McGill Quality of Life Questionnaire (MQOL) at hospice\\/palliative

  15. Time Course and Characteristics of Symptom Distress and Quality of Life at the End of Life

    Microsoft Academic Search

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

    2007-01-01

    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,

  16. Detector based on microchannel plates for monitoring space-time characteristics of a circulating beam at Nuclotron

    NASA Astrophysics Data System (ADS)

    Baldin, A. A.; Berlev, A. I.; Kudashkin, I. V.; Fedorov, A. N.

    2014-03-01

    In the framework of the NICA project preparation and experiments with the extracted Nuclotron beams, the development of an advanced system of circulating-beam diagnostics based on microchannel plates is presented. The detector prototype that has been developed, created, and tested on Nuclotron beams during four runs allows the space-time characteristics of a beam to be measured within a range of singly charged ion intensities from 106 to 109, which is not covered by the existing measuring tools.

  17. Time-domain finite difference approach to the calculation of the frequency-dependent characteristics of microstrip discontinuities

    Microsoft Academic Search

    Xiaolei Zhang; Kenneth K. Mei

    1988-01-01

    The frequency-dependent characteristics of the microstrip discontinuities have previously been analyzed using full-wave approaches. The time-domain finite-difference (TD-FD) method presented here is an independent approach and is relatively new in its application for obtaining the frequency-domain results for microwave components. The validity of the TD-FD method in modeling circuit components for MMIC CAD applications is established.

  18. Impact of real-time traffic characteristics on freeway crash occurrence: Systematic review and meta-analysis.

    PubMed

    Roshandel, Saman; Zheng, Zuduo; Washington, Simon

    2015-06-01

    The development of methods for real-time crash prediction as a function of current or recent traffic and roadway conditions is gaining increasing attention in the literature. Numerous studies have modeled the relationships between traffic characteristics and crash occurrence, and significant progress has been made. Given the accumulated evidence on this topic and the lack of an articulate summary of research status, challenges, and opportunities, there is an urgent need to scientifically review these studies and to synthesize the existing state-of-the-art knowledge. This paper addresses this need by undertaking a systematic literature review to identify current knowledge, challenges, and opportunities, and then conducts a meta-analysis of existing studies to provide a summary impact of traffic characteristics on crash occurrence. Sensitivity analyses were conducted to assess quality, publication bias, and outlier bias of the various studies; and the time intervals used to measure traffic characteristics were also considered. As a result of this comprehensive and systematic review, issues in study designs, traffic and crash data, and model development and validation are discussed. Outcomes of this study are intended to provide researchers focused on real-time crash prediction with greater insight into the modeling of this important but extremely challenging safety issue. PMID:25841161

  19. Error propagation in time-dependent probability of occurrence for characteristic earthquakes in Italy

    Microsoft Academic Search

    Laura Peruzza; Bruno Pace; Fabio Cavallini

    2010-01-01

    Time-dependent models for seismic hazard and earthquake probabilities are at the leading edge of research nowadays. In the\\u000a framework of a 2-year national Italian project (2005–2007), we have applied the Brownian passage time (BPT) renewal model\\u000a to the recently released Database of Individual Seismogenic Sources (DISS) to compute earthquake probability in the period\\u000a 2007–2036. Observed interevent times on faults in

  20. Evaluation of timing characteristics of a prototype system based on PROFINET IO RT_Class 3

    Microsoft Academic Search

    Paolo Ferrari; Alessandra Flammini; Daniele Marioli; Andrea Taroni; Francesco Venturini

    2007-01-01

    The PROFINET architecture can provide real-time, high-performance, isochronous communication regardless the presence of other real-time data exchange and TCP\\/IP traffic for a considerable portion of network bandwidth. In this work some experimental tests have been executed in order to evaluate timing performance of a PROFINET ASIC (ERTEC 400 chip) and its related development kits. Results shows that communication isochrony has

  1. Effect of different egg storage times on some egg quality characteristics and hatchability of pheasants (Phasianus colchicus).

    PubMed

    Demirel, S; Kirikçi, K

    2009-02-01

    In this study, some quality characteristics and hatchability characteristics of 1 to 2, 3 to 4, 5 to 6, 7 to 8, 9 to 10, 11 to 12, and 13 to 14 d stored pheasant eggs were investigated. Although it was determined that the effect of storage time on egg weight, shape index, and albumen weight was not significant, the effect of storage time on eggshell weight, shell thickness, yolk weight, albumen index, yolk index, Haugh unit, shell percentage, albumen percentage, and yolk percentage was significant (P<0.05). It was determined that prolonged storage time caused a decrease in the albumen index and Haugh unit value but an increase in the yolk index of pheasant eggs. There was no positive or negative effect of storage time on the fertility rates and hatchability of fertile eggs, but there was a negative effect of storage time on hatchability on d 8 (P<0.05). Pheasant eggs should not be stored more than 8 d. PMID:19151360

  2. 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.

  3. Characteristics of the ionospheric variability as a function of season, latitude, local time, and geomagnetic activity

    Microsoft Academic Search

    E. A. Araujo-Pradere; T. J. Fuller-Rowell; M. V. Codrescu; D. Bilitza

    2005-01-01

    An ionospheric F2 critical frequency database has been assembled to determine the variability of the F region as a function of local time, latitude, season, and geomagnetic activity. The database comprises observations from 75 ionosonde stations covering a range of geomagnetic latitude and includes 43 storm intervals. The database was previously used to develop the Storm-Time Empirical Ionospheric Correction Model

  4. Space - time diaries and travel characteristics for different levels of respondent aggregation

    Microsoft Academic Search

    D G Janelle; M F Goodchild; B Klinkenberg

    1988-01-01

    Significant progress has been made in the analysis of space - time diary data. Drawing on the flexibility that such data provide, in this study the authors group respondents at five different levels of aggregation, and compare them according to their mean and standard deviation values for selected measures of travel behaviour. The measures, derived from the time - geography

  5. Time Sensitivity Factor of Single Pulmonary Nodule: A New Cancer Characteristic Metabolic Parameter by 18F-FDG PET

    PubMed Central

    Cheng, Ching-Yuan; Lee, Kwo-Whei; Lee, Chiang-Hsuan; Tyan, Yeu-Sheng; Cheng, Cheng-Yi; Wang, Jhi-Joung; Yang, Chao-Wei; Huang, Wen-Sheng; Oliver Wong, Ching-Yee

    2014-01-01

    Objective. To calculate the time sensitivity factor (S) for discriminating the solitary pulmonary nodule (SPN) by FDG PET at different time points. Methods. The multiple time-point FDG PET images from 41 patients for evaluating SPN seen on chest X-ray or CT were prospectively analyzed to calculate and evaluate S against the gold standard of tissue histology (n = 38) or long term clinicoradiographic follow-up (n = 3). The maximal standardized uptake values (SUV) at the 3 hourly time points were measured. The S was calculated using S = d{ln?(SUV)}/d{ln?(t)} at 3 different time intervals. ROC analysis of the S parameters was performed to evaluate the optimal cut-off value and their accuracy in classifying the SPN. Results. The SUV in malignant SPN was higher than the corresponding value in benign lesions at all 3 hourly time points (P < 0.003). The S parameters using 3 different time intervals all significantly separated the two groups (P < 0.0005) with an optimal cut-off point near the theoretical value of zero with a high sensitivity of 100% and specificity of 86%. Conclusion. The S can be calculated for SPNs using multiple time-point FDG PET, providing a tumor characteristic metabolic parameter with high discrimination power using a simple positive value representing malignancy. PMID:24982908

  6. Characteristic-based algorithms for solving the Maxwell equations in the time domain

    Microsoft Academic Search

    J. S. Slrang; Wright-Patterson AFB

    1995-01-01

    Several numerical algorithms, developed in the computational-fluid-dynamics community for solving the Euler equations, are found to be equally effective for solving the Maxwell equations in the time domain. The basic approach of these numerical procedures is to achieve the Riemann approximation to the time-dependent, three-dimensional problem in each spatial direction. The three-dimensional equations are then solved by a sequence of

  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 (?=0.6), running speed during training (?=-3.7), and body mass index (?=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 (?=0.8) and running speed during training (?=-4.1) remained predictive. In women, body fat percentage (?=0.75) and speed during training (?=-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. 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. (Seattle National Fishery Research Center, Columbia River Field Station, Cook, WA)

    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.

  9. An 8 h characteristic time-scale in submillimetre light curves of Sagittarius A*

    NASA Astrophysics Data System (ADS)

    Dexter, Jason; Kelly, Brandon; Bower, Geoffrey C.; Marrone, Daniel P.; Stone, Jordan; Plambeck, Richard

    2014-08-01

    We compile and analyse long-term (?10 yr) submillimetre (submm - 1.3, 0.87, 0.43 mm) wavelength light curves of the Galactic Centre black hole, Sagittarius A*. The 0.87 and 0.43 mm data are taken from the literature, while the majority of the 1.3 mm light curve is from previously unpublished SMA and CARMA data. We show that on minute to a few hour time-scales, the variability is consistent with a red noise process with a 230 GHz power-spectrum slope of ? =2.3^{+0.8}_{-0.6} at 95 per cent confidence. The light curve is decorrelated (white noise) on long (month to year) times. We measure a transition time between red and white noise of ? = 8_{-4}^{+3} h at 230 GHz at 95 per cent confidence, with consistent results at 345 and 690 GHz. This corresponds to ?10 orbital times or ?1 inflow (viscous) time at R = 3Rs, a typical radius producing the 230 GHz emission as measured by very long baseline interferometry and found in theoretical accretion flow and jet models. This time-scale is shorter (longer) than those measured by some analyses of radio (near-infrared) light curves. It is roughly consistent with the analogous time-scale inferred in studies of quasar optical light curves after accounting for the difference in emission radius. We find evidence that the submm variability persists at least down to the innermost stable circular orbit, if not the event horizon. These results can be compared quantitatively with similar analyses at different wavebands to test for connections between the variability mechanisms, and with light curves from theoretical models of accreting black holes.

  10. The internal clock: evidence for a temporal oscillator underlying time perception with some estimates of its characteristic frequency.

    PubMed

    Treisman, M; Faulkner, A; Naish, P L; Brogan, D

    1990-01-01

    Evidence for the proposition that human time perception is determined by an internal clock is largely indirect. It would strengthen the case for this hypothesis if a model for the internal clock were available from which predictions could be derived and tested, and if the basic parameter of such a model, the frequency at which the clock runs, could be estimated. A model for an internal temporal pacemaker is briefly described and its properties are explored by computer simulation. Results are obtained that provide a basis for predicting that, under appropriate conditions, interference between an imposed rhythm and the frequency of a temporal oscillator may cause perturbations in temporal judgment which are related to the characteristic frequency of that oscillator. Experimental data are reported which appear to demonstrate such an interference pattern. These results allow some estimates of the characteristic frequency of the temporal oscillator to be obtained. PMID:2130371

  11. 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.

  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. The role of laminar-turbulent transition in gas turbine engines: A discussion

    SciTech Connect

    Walker, G.J. (Univ. of Tasmania, Hobart (Australia))

    1993-04-01

    An extended discussion of Mayle's critical study of transition phenomena in gas turbine engines is presented. Attention is focused on transition in decelerating flow regions, which are the major sources of loss production for axial turbomachine blades. The following points are examined in detail: (a) the physics of transition and its implications for the correlation of various transition phenomena; (b) the relative importance of pressure gradient and free-stream turbulence in controlling transition; (c) the influence of pressure gradient on periodic-unsteady transition; (d) the correlation of transition length under conditions of arbitrary pressure gradient and free-stream turbulence level; and (e) transition behavior in laminar separation bubbles. The discussion examines various differences in philosophy concerning the above phenomena and makes further suggestions for transition research, which may assist in resolving the issues raised.

  14. Laminar-turbulent separatrix in a boundary layer flow Damien BIAU

    E-print Network

    Paris-Sud XI, Université de

    aerodynamic drag. On the other hand, promoting transition permits an increase in mixing, heat transfer of the Prandtl boundary layer equations while the superposed small-scale fluctuations are a solution of the periodic Navier-Stokes equations. The model is validated with turbulent flow simulations and satisfactorily

  15. Space-Time Characteristics of Light Transmitted through Dense Clouds: A Green's Function Analysis

    Microsoft Academic Search

    Anthony B. Davis; Alexander Marshak

    2002-01-01

    Here, previous work using photon diffusion theory to describe radiative transfer through dense plane-parallel clouds at nonabsorbing wavelengths is extended. The focus is on the scaling of space- and time-domain moments for transmitted light with respect to cloud thickness H and optical depth ; and the new results are as follows: accurate prefactors for asymptotic scaling, preasymptotic correction terms in

  16. Time-Domain Modelling of Group-Delay and Amplitude Characteristics

    E-print Network

    Bornemann, Jens

    With the release of the 3.1­10.6 GHz band for ultra-wideband (UWB) operation, a variety of typical UWB applications of UWB antennas in printed-circuit technologies within relatively small substrate areas is of primary) method in the time domain is utilized to determine the group delay of two printed circuit UWB antennas

  17. Comparison of gender-specific human embryo development characteristics by time-lapse technology.

    PubMed

    Serdarogullari, Munevver; Findikli, Necati; Goktas, Cihan; Sahin, Oya; Ulug, Ulun; Yagmur, Erbil; Bahceci, Mustafa

    2014-08-01

    Numerous studies indicate that there might be differences in embryo growth dynamics between male and female embryos. However, current data in humans are scarce and the results are inconclusive or conflicting. This study asks whether there exist gender-specific embryo development kinetics or parameters between human male and female embryos that can be observed by time-lapse technology. Study included data from 139 consecutive cycles (177 embryos transferred, 179 sacs analysed) with positive pregnancy that resulted in 100% implantation. Single- or double-embryo transfers were performed. Cases were analysed for parameters including cleavage time points and duration in each cleavage from two cells to hatching blastocyst stages and time interval between cleavages. Morphokinetic parameters of 78 female and 60 male embryos from a total of 119 cycles (139 sacs were examined after transfer of 138 embryos) were processed for data analysis according to the gender group. A detailed analysis of the data regarding each time point or interval between consecutive events according to these groups showed them to be similar in cell division kinetics, from the early cleavage through their development to blastocyst stage. However, female embryos showed earlier cavitation than male embryos, but the results did not reach statistical significance. PMID:24925308

  18. The Cuffless Arterial Blood Pressure Estimation based on the Timing Characteristics of Second Heart Sound

    Microsoft Academic Search

    M. Y. M. Wong; X. Y. Zhang; Y. T. Zhang

    2006-01-01

    Continuous and non-invasive monitoring of blood pressure (BP) is important to prevent hypertensive patients from stroke and heart attack. However, most of the prevalent BP devices can provide solely intermittent measurements. In this study, a novel parameter RS2 , defined as the time interval from the R wave of electrocardiographic (ECG) signal to the peak of second heart sound of

  19. First-Time International and Domestic Freshmen: Enrollment Trends and Characteristics.

    ERIC Educational Resources Information Center

    Overall, J. U.

    Selected comparisons of first-time international and domestic freshmen at the University of Southern California (USC) were undertaken, using data from the annual Higher Education General Information Survey (HEGIS) and the American Council on Education Freshman Survey. On-campus enrollment data for these two student groups are presented by sex for…

  20. Multiscaling for systems with a broad continuum of characteristic lengths and times: Structural transitions in nanocomposites.

    PubMed

    Pankavich, S; Ortoleva, P

    2010-06-01

    The multiscale approach to N-body systems is generalized to address the broad continuum of long time and length scales associated with collective behaviors. A technique is developed based on the concept of an uncountable set of time variables and of order parameters (OPs) specifying major features of the system. We adopt this perspective as a natural extension of the commonly used discrete set of time scales and OPs which is practical when only a few, widely separated scales exist. The existence of a gap in the spectrum of time scales for such a system (under quasiequilibrium conditions) is used to introduce a continuous scaling and perform a multiscale analysis of the Liouville equation. A functional-differential Smoluchowski equation is derived for the stochastic dynamics of the continuum of Fourier component OPs. A continuum of spatially nonlocal Langevin equations for the OPs is also derived. The theory is demonstrated via the analysis of structural transitions in a composite material, as occurs for viral capsids and molecular circuits. PMID:20661319

  1. Multiscaling for systems with a broad continuum of characteristic lengths and times: Structural transitions in nanocomposites

    PubMed Central

    Pankavich, S.; Ortoleva, P.

    2010-01-01

    The multiscale approach to N-body systems is generalized to address the broad continuum of long time and length scales associated with collective behaviors. A technique is developed based on the concept of an uncountable set of time variables and of order parameters (OPs) specifying major features of the system. We adopt this perspective as a natural extension of the commonly used discrete set of time scales and OPs which is practical when only a few, widely separated scales exist. The existence of a gap in the spectrum of time scales for such a system (under quasiequilibrium conditions) is used to introduce a continuous scaling and perform a multiscale analysis of the Liouville equation. A functional-differential Smoluchowski equation is derived for the stochastic dynamics of the continuum of Fourier component OPs. A continuum of spatially nonlocal Langevin equations for the OPs is also derived. The theory is demonstrated via the analysis of structural transitions in a composite material, as occurs for viral capsids and molecular circuits. PMID:20661319

  2. Multiscaling for systems with a broad continuum of characteristic lengths and times: Structural transitions in nanocomposites

    NASA Astrophysics Data System (ADS)

    Pankavich, S.; Ortoleva, P.

    2010-06-01

    The multiscale approach to N-body systems is generalized to address the broad continuum of long time and length scales associated with collective behaviors. A technique is developed based on the concept of an uncountable set of time variables and of order parameters (OPs) specifying major features of the system. We adopt this perspective as a natural extension of the commonly used discrete set of time scales and OPs which is practical when only a few, widely separated scales exist. The existence of a gap in the spectrum of time scales for such a system (under quasiequilibrium conditions) is used to introduce a continuous scaling and perform a multiscale analysis of the Liouville equation. A functional-differential Smoluchowski equation is derived for the stochastic dynamics of the continuum of Fourier component OPs. A continuum of spatially nonlocal Langevin equations for the OPs is also derived. The theory is demonstrated via the analysis of structural transitions in a composite material, as occurs for viral capsids and molecular circuits.

  3. Evaluation of Timing Characteristics of Industrial Ethernet Networks Synchronized by means of IEEE 1588

    Microsoft Academic Search

    A. Depari; P. Ferrari; A. Flammini; D. Marioli; A. Taroni

    2007-01-01

    This paper deals with time synchronization of distributed systems over Industrial Ethernet network. A new simulation model of IEEE1588 PTP is presented and discussed. The development platform used for simulation is OPNETtrade. Architecture of the proposed model is explained in details, highlighting some special features introduced by authors: modelization of drift and rate variations in the local oscillator and packet

  4. 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…

  5. Global dynamical modeling of time series and application to restoration of broadband signal characteristics

    SciTech Connect

    Gribkov, D.A.; Gribkova, V.V.; Kuznetsov, Y.I.; Rzhanov, A.G. [Physical Department of Moscow State University, Moscow, 119899 (Russia)

    1996-06-01

    We show the principle possibility of the external complex action restoring using the nonlinear dynamics inverse problem solution. It is shown that broadband signal can be restored from the time series of the process generated by nonstationary chaotic system using the reconstructed model as the nonlinear filter. {copyright} {ital 1996 American Institute of Physics.}

  6. 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 ?Pa 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. PMID:22225022

  7. Systems approach to evaluating sensor characteristics for real-time monitoring of high-risk indoor contaminant releases

    NASA Astrophysics Data System (ADS)

    Sreedharan, Priya; Sohn, Michael D.; Gadgil, Ashok J.; Nazaroff, William W.

    Rapid detection of toxic agents in the indoor environment is essential for protecting building occupants from accidental or intentional releases. While there is much research dedicated to designing sensors to detect airborne toxic contaminants, little research has addressed how to incorporate such sensors into a monitoring system designed to protect building occupants. To design sensor systems, one must quantify design tradeoffs, such as response time and accuracy, and select values to optimize the performance of an overall system. We illustrate the importance of a systems approach for properly evaluating such tradeoffs, using data from tracer gas experiments conducted in a three-floor building at the Dugway Proving Grounds, Utah. We explore how well a Bayesian interpretation approach can characterize an indoor release using threshold sensor data. We use this approach to assess the effects of various sensor characteristics, such as response time, threshold level, and accuracy, on overall system performance. The system performance is evaluated in terms of the time needed to characterize the release (location, amount released, and duration). We demonstrate that a systems perspective enables selecting sensor characteristics that optimize the system as a whole.

  8. Impact of sow and litter characteristics on colostrum yield, time for onset of lactation, and milk yield of sows.

    PubMed

    Vadmand, C N; Krogh, U; Hansen, C F; Theil, P K

    2015-05-01

    The aim of the present study was to estimate the concurrent impact of sow and litter characteristics on sow productivity. Sow productivity was defined as colostrum yield (CY), onset of lactation (the time point when milk secretion increased steeply, approximately 31 h postpartum), transition milk yield (MY; 36-60 h postpartum), and the mean MY in wk 1 to 4 of lactation. Therefore, the study investigated how factors related with sow nutrition, litter characteristics, farrowing characteristics, and composition of mammary secreta affected sow productivity. Data obtained from 5 previous sow experiments were used. The variables describing sow productivity were all defined as dependent variables and Pearson coefficient of correlation was used to examine relations among dependent variables. The results showed that CY was positively correlated with transition MY and MY in wk 1 and 2 of lactation ( < 0.05), and time for onset of lactation was positively correlated with transition MY ( < 0.05) but negatively correlated with MY in wk 1, 2, and 4 of lactation ( < 0.05). Multivariate regression analyses with a backward elimination approach were performed for each dependent variable to investigate relations with characteristics of sow nutrition, litter size, farrowing, and composition of mammary secreta (independent variables). Litter size was positively related with both CY and MY in wk 1 to 4 ( < 0.001). Milk protein concentration was negatively correlated with MY in all 4 wk ( < 0.01), which indicated that high yielding sows were unable to maintain milk protein synthesis during lactation. Additionally, mean intake of ME prepartum ( < 0.05) was included in the regression model for transition MY and the BW of the sow on d 3 was included in the regression model for MY in wk 1 ( < 0.05). Except litter equlization, none of the observed independent variables were related with time for onset of lactation. In conclusion, when maximizing sow productivity in the future, it may be rewarding to pay attention to sow productivity in the colostrum period and around time for onset of lactation, and special attention should be given to dietary supplies of protein and essential AA. PMID:26020344

  9. Temporal propagation characteristics of ultrashort space- time Gaussian pulses in a laser satellite communication system

    Microsoft Academic Search

    Deborah Eliza Tjin Tham Sjin Kelly

    1998-01-01

    Tractable analytic expressions are obtained for the temporal broadening and scintillations of a narrowband, space-time Gaussian pulse propagating through clear-air weak atmospheric turbulence in a laser satellite communication system. The temporal broadening is deduced from the 1\\/e2 point of the temporal mean intensity and calculation of the temporal scintillations involves the second moment of intensity. Integral representations for the first

  10. 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.

  11. Effect of heating time and temperature on the chemical characteristics of biochar from poultry manure.

    PubMed

    Cimò, Giulia; Kucerik, Jiri; Berns, Anne E; Schaumann, Gabriele E; Alonzo, Giuseppe; Conte, Pellegrino

    2014-02-26

    Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical-physical characterization of the different PM chars was conducted by cross-polarization magic angle spinning (CPMAS) (13)C NMR spectroscopy and thermal analysis. CPMAS (13)C NMR spectra showed that the chemical composition of PM char is dependent on production temperature rather than on production duration. Aromatic and alkyl domains in the PM chars obtained at the lowest temperatures remained unchanged at all heating times applied for their production. The PM char obtained at the highest temperature consisted only of aromatic structures having chemical nature that also appeared invariant with heating time. Thermogravimetry revealed differences in the thermo-oxidative stability of the aromatic domains in the different PM chars. The PM char produced at the highest temperature appeared less stable than those produced at the lowest temperatures. This difference was explained by a protective effect of the alkyl groups, which are still present in chars formed at lower temperature. The analysis of the chemical and physicochemical character of poultry manure chars produced at different temperatures can increase understanding of the role of these materials in the properties and behavior of char-amended soils. PMID:24506474

  12. 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

  13. 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. PMID:25592738

  14. Timing of Malaria Infection during Pregnancy Has Characteristic Maternal, Infant and Placental Outcomes

    PubMed Central

    Kalilani-Phiri, Linda; Thesing, Phillip C.; Nyirenda, Osward M.; Mawindo, Patricia; Madanitsa, Mwayi; Membe, Gladys; Wylie, Blair; Masonbrink, Abbey; Makwakwa, Kingsley; Kamiza, Steve; Muehlenbachs, Atis; Taylor, Terrie E.; Laufer, Miriam K.

    2013-01-01

    We conducted a clinical study of pregnant women in Blantyre, Malawi to determine the effect of the timing of malaria infection during pregnancy on maternal, infant and placental outcomes. Women were enrolled in their first or second trimester of their first or second pregnancy and followed every four weeks until delivery. Three doses of sulfadoxine-pyrimethamine were given for intermittent preventive treatment for malaria, and all episodes of parasitemia were treated according to the national guidelines. Placentas were collected at delivery and examined for malaria parasites and pigment by histology. Pregnant women had 0.6 episodes of malaria per person year of follow up. Almost all episodes of malaria were detected at enrollment and malaria infection during the follow up period was rare. Malaria and anemia at the first antenatal visit were independently associated with an increased risk of placental malaria detected at delivery. When all episodes of malaria were treated with effective antimalarial medication, only peripheral malaria infection at the time of delivery was associated with adverse maternal and infant outcomes. One quarter of the analyzed placentas had evidence of malaria infection. Placental histology was 78% sensitive and 89% specific for peripheral malaria infection during pregnancy. This study suggests that in this setting of high antifolate drug resistance, three doses of sulfadoxine-pyrimethamine maintain some efficacy in suppressing microscopically detectable parasitemia, although placental infection remains frequent. Even in this urban setting, a large proportion of women have malaria infection at the time of their first antenatal care visit. Interventions to control malaria early and aggressive case detection are required to limit the detrimental effects of pregnancy-associated malaria. PMID:24058614

  15. 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.

  16. Physical characteristics of TTV03, a new high spatial resolution time-of-flight positron tomograph

    Microsoft Academic Search

    B. Mazoyer; R. Trebossen; C. Schoukroun; B. Verrey; A. Syrota; J. Vacher; P. Lemasson; O. Monnet; A. Bouvier; J. L. Lecomte

    1990-01-01

    TTV03, a novel high-spatial-resolution TOF-PET (time-of-flight positron emission tomography) system, is presented. The machine consists of four 89-cm-diameter rings made of 7-mm-wide, 18-mm-high, 45-mm-deep BaF2 crystals (324 per ring) individually coupled to 11-mm-diameter phototubes. The transaxial resolution (full width at half maximum or FWHM) in the reconstructed image is 5.7 mm at center, 5.7 mm (tangential), and 6.5 mm (radial)

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

    SciTech Connect

    Paulino, Arnold C., E-mail: apaulino@tmhs.or [Department of Radiology, Section of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States); Ahmed, Irfan M.; Mai, Wei Y.; Teh, Bin S. [Department of Radiology, Section of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States)

    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.

  18. SPACE-TIME CHARACTERISTICS OF DIURNAL RAINFALL VARIATION IN MATSUYAMA PLAIN

    NASA Astrophysics Data System (ADS)

    Fujimoto, Masato; Watanabe, Keiko; Moriwaki, Ryo

    We investigated the diurnal rainfall variation in Matsuyama plain using datasets from AMeDAS, MLIT, and local government. The evening maximum precipitation is especially remarkable in the inland region and along a river. It is known that a river is street of wind for land and sea breezes. Sea breeze would contribute to an increase in the water vapor content over inland regions through the moist air advection from coastal regions. During the period of 1980-2009, the time when the morning maximum precipitation appears shift two hours later every ten years. Similarly, the offshore land breeze is getting more significant at the rate of 200 ms-1h every ten years.

  19. 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 scale of a single block surface, with initial small-scale differences across a surface having larger scale consequences as weathering progresses. After cycle 10, group B blocks show a much smaller increase in mean permeability, and the range stays relatively steady — this may be explained by the capillary conditions set up by the smaller volume of the stone, allowing salts to migrate to the 'back' of the blocks and effectively relieving stress at the 'front' face.

  20. Storm-time characteristics of the equatorial ionization anomaly in the East African sector

    NASA Astrophysics Data System (ADS)

    Kassa, T.; Damtie, B.; Bires, A.; Yizengaw, E.; Cilliers, P.

    2015-07-01

    The equatorial ionization anomaly (EIA), inferred from the electron density profile, was used to study the ionospheric effect of 11 March 2011, 06 April 2011, 09 March 2012 and 01 October 2012 geomagnetic storms in the East African sector. The electron density profile was reconstructed from slant total electron content (sTEC) measurements using statistical linear inversion method. The sTEC measurements were recorded by a chain of ten ground-based GPS receivers deployed in the East African region in the latitude range of 6° S-20° N GeoLat (15.29° S-10.62° N geomagnetic latitude). The analysis of the effect of the storms on the EIA has demonstrated that the effect could be positive or negative. The sudden positive effects of the EIA, in terms of increasing the peak and widening the width, during storm events of 06 April 2011, 09 March 2012 and 01 October 2012 were observed dominantly due to prompt penetration electric fields to the magnetic equator, which were caused by a southward turning of the interplanetary magnetic field (Bz). The prolonged effects after the onset of the storm were attributed to disturbance dynamo electric field due to the storm-time neutral wind circulation. The depletion on the electron density profile during 11 March 2011 storm was due to a decrease in [O] to [N2 ] ratio in the thermosphere composition.

  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. Plasticity in timing of migration in response to climatic conditions and plant phenology may be an adaptive behavioral strategy, which should reduce the detrimental effects of trophic mismatches between resources and other life-history events of large herbivores. Failure to consider effects of nutrition and other life-history traits may cloud interpretation of phenological patterns of mammals and conceal relationships associated with climate change.

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

    Microsoft Academic Search

    W. Edward Montz; William C. Card; Roy L. Kirkpatrick

    1982-01-01

    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

  3. 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 communities. Oikos. 2012;121(11):1810-1820 10.1111/j.1600-0706.2011.20423.x Scheuring, I., Riedi, R.H., 1994. Application of multifractals to the analysis of vegetation pattern. J. Veg. Sci. 5, 489-496. Solé RV, Bascompte J.: Self-organization in complex ecosystems. Princeton University Press,2006. Acknowledgements First author acknowledges the Research Grant obtained from CEIGRAM in 2014

  4. Effects of adding whole body vibration to squat training on isometric force/time characteristics.

    PubMed

    Lamont, Hugh S; Cramer, Joel T; Bemben, Debra A; Shehab, Randa L; Anderson, Mark A; Bemben, Michael G

    2010-01-01

    Resistance training interventions aimed at increasing lower-body power and rates of force development have produced varying results. Recent studies have suggested that whole-body low-frequency vibration (WBLFV) may elicit an acute postactivation potentiation response, leading to acute improvements in power and force development. Potentially, the use of WBLFV between sets of resistance training rather than during training itself may lead to increased recruitment and synchronization of high-threshold motor units, minimize fatigue potential, and facilitate the chronic adaptation to resistance exercise. The purpose of this study was to determine the effects of applying TriPlaner, WBLFV, prior to and then intermittently between sets of Smith machine squats on short-term adaptations in explosive isometric force expression. Thirty recreationally resistance trained men aged 18-30 were randomly assigned to 1 of 3 groups: resistance training only (SQT, n = 11), resistance plus whole-body vibration (SQTV, n = 13), or active control (CON, n = 6). An isometric squat test was performed prior to and following a 6-week periodized Smith machine squat program. Whole-body low-frequency vibration was applied 180 seconds prior to the first work set (50 Hz, 2-4 mm, 30 seconds) and intermittently (50 Hz, 4-6 mm, 3 x 10 seconds, 60 seconds between exposures) within a 240-second interset rest period. Subjects were instructed to assume a quarter squat posture while positioning their feet directly under their center of mass, which was modified using a handheld goniometer to a knee angle of 135 +/- 5 degrees . Instructions were given to subjects to apply force as fast and as hard as possible for 3.5 seconds. Isometric force (N) and rates of force development (N.s(-1)) were recorded from the onset of contraction (F(0)) to time points corresponding to 30, 50, 80, 100, 150, and 250 milliseconds, as well as the peak isometric rate of force development (PISORFD), and rate of force development to initial peak in force (RFDinitial). Repeated measures analysis of variance and analysis of covariance revealed no significant group by trial interactions for isometric rate of force development (ISORFD) between 0-30, 0-50, 0-80, 0-100, 0-150, and 0-250 milliseconds and PISORFD (p > 0.05). A significant group x trial interaction was seen for RFDinitial with SQTV >CG (p = 0.04, mean difference 997.2 N.s(-1)) and SQTV >SQT (p = 0.04, mean difference 1,994.22 N.s(-1)). Significant trial by covariate interactions (week one measures for ISORFD) and main effects for trial were observed for ISORFD between 0-80, 0-100, 0-and 150 milliseconds; PISORFD; and RFDinitial (p < 0.01). A significant trial effect was seen for Finitial (%) when expressed as a relative percentage of maximal voluntary contraction (MVC) (MVC = 100%) (p = 0.015; week 1 > week 7, mean difference, 5.82%). No significant differences were seen for any other force variables from the onset of contraction to MVC between weeks 1 and 7 (p > 0.05). The data suggest that there was a significant benefit afforded by adding WBLFV to a short-term resistance training protocol with regard to "explosive" strength expression. The addition of vibration prior to and between sets of resistance exercise may be a viable alternative to vibration applied during resistance exercise when trying to improve "explosive" isometric strength. PMID:19924007

  5. The JDRF CCTN CGM TIME Trial: Timing of Initiation of continuous glucose Monitoring in Established pediatric type 1 diabetes: study protocol, recruitment and baseline characteristics

    PubMed Central

    2014-01-01

    Background Continuous glucose monitoring (CGM) has been shown to improve glucose control in adults with type 1 diabetes. Effectiveness of CGM is directly linked with CGM adherence, which can be challenging to maintain in children and adolescents. We hypothesize that initiating CGM at the same time as starting insulin pump therapy in pump naïve children and adolescents with type 1 diabetes will result in greater CGM adherence and effectiveness compared to delaying CGM introduction by 6 months, and that this is related to greater readiness for making behaviour change at the time of pump initiation. Methods/Design The CGM TIME Trial is a multicenter randomized controlled trial. Eligible children and adolescents (5-18 years) with established type 1 diabetes were randomized to simultaneous initiation of pump (Medtronic Veo©) and CGM (Enlite©) or to standard pump therapy with delayed CGM introduction. Primary outcomes are CGM adherence and hemoglobin A1C at 6 and 12 months post pump initiation. Secondary outcomes include glycemic variability, stage of readiness, and other patient-reported outcomes with follow-up to 24 months. 144 (95%) of the 152 eligible patients were enrolled and randomized. Allowing for 10% withdrawals, this will provide 93% power to detect a between group difference in CGM adherence and 86% power to detect a between group difference in hemoglobin A1C. Baseline characteristics were similar between the treatment groups. Analysis of 12 month primary outcomes will begin in September 2014. Discussion The CGM TIME Trial is the first study to examine the relationship between timing of CGM initiation, readiness for behaviour change, and subsequent CGM adherence in pump naïve children and adolescents. Its findings will advance our understanding of when and how to initiate CGM in children and adolescents with type 1 diabetes. Trial registration ClinicalTrial.gov NCT01295788. Registered 14 February 2011. PMID:25034216

  6. Donor Heart Utilization following Cardiopulmonary Arrest and Resuscitation: Influence of Donor Characteristics and Wait Times in Transplant Regions

    PubMed Central

    Wolfe, Luke; Kasirajan, Vigneshwar

    2014-01-01

    Background. Procurement of hearts from cardiopulmonary arrest and resuscitated (CPR) donors for transplantation is suboptimal. We studied the influences of donor factors and regional wait times on CPR donor heart utilization. Methods. From UNOS database (1998 to 2012), we identified 44,744 heart donors, of which 4,964 (11%) received CPR. Based on procurement of heart for transplantation, CPR donors were divided into hearts procured (HP) and hearts not procured (HNP) groups. Logistic regression analysis was used to identify predictors of heart procurement. Results. Of the 4,964 CPR donors, 1,427 (28.8%) were in the HP group. Donor characteristics that favored heart procurement include younger age (25.5?±?15?yrs versus 39?±?18?yrs, P ? 0.0001), male gender (34% versus 23%, P ? 0.0001), shorter CPR duration (<15?min versus >30?min, P ? 0.0001), and head trauma (60% versus 15%). Among the 11 UNOS regions, the highest procurement was in Region 1 (37%) and the lowest in Region 3 (24%). Regional transplant volumes and median waiting times did not influence heart procurement rates. Conclusions. Only 28.8% of CPR donor hearts were procured for transplantation. Factors favoring heart procurement include younger age, male gender, short CPR duration, and traumatic head injury. Heart procurement varied by region but not by transplant volumes or wait times. PMID:25114798

  7. 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. PMID:25642025

  8. 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.

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

    NASA Astrophysics Data System (ADS)

    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

    2014-02-01

    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.

  10. Long-Characteristics Methods with Piecewise Linear Sources in Space and Time for Transport on Unstructured Grids 

    E-print Network

    Pandya, Tara M 1984-

    2012-10-23

    The method of characteristics (MOC) is a deterministic transport method that has been applied to large-scale problems including those in reactor physics and radiative transfer. Long characteristics, (LC) methods, have been used extensively...

  11. A study of Time\\/Current Characteristics of the Ignition Processes in Cellulosic Material Caused by Electrical Arcing for Application in 240V Arc-Fault Circuit Interrupters

    Microsoft Academic Search

    D. Kolker; S. Campolo; N. DiSalvo

    2007-01-01

    In the development of Arc-Fault Circuit interrupters (AFCIs), one of the most important parameters is the time that an arcing fault could persist before the device will interrupt the current flow and hopefully mitigate fire propagation. In 1996 Underwriters laboratories (UL) published a report on time\\/current ignition characteristics of arcs at 120 V. Despite the very limited number of tests

  12. Time and frequency requirement for the earth and ocean physics applications program. [characteristics and orbital mechanics of artificial satellites for data acquisition

    NASA Technical Reports Server (NTRS)

    Vonbun, F. O.

    1972-01-01

    The application of time and frequency standards to the Earth and Ocean Physics Applications Program (EOPAP) is discussed. The goals and experiments of the EOPAP are described. Methods for obtaining frequency stability and time synchronization are analyzed. The orbits, trajectories, and characteristics of the satellites used in the program are reported.

  13. 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 the time-synchronization procedures shown here, arrays may be built out of stand-alone recorders that simplify the deployment logistics and can be arranged in multiple configurations. Given increasing economic pressures worldwide, anthropogenic activities in the ocean are only expected to expand, and their ambient noise contributions will continue to rise. These studies provide baseline knowledge and practical tools to help properly assess the impact of such source mechanisms in shallow-water acoustic environments.

  14. Effects of slaughter time post-second injection on carcass cutting yields and bacon characteristics of immunologically castrated male pigs.

    PubMed

    Boler, D D; Killefer, J; Meeuwse, D M; King, V L; McKeith, F K; Dilger, A C

    2012-01-01

    Body weights of finishing pigs can be variable within a finishing barn near the time of slaughter; therefore, it is common to market pigs over a period of time. This allows lighter pigs more time to gain BW and approach a desired end point. Use of immunological castration late in life to control boar taint, as an alternative to physical castration early in life, increases cutting yields of finishing male pigs compared with physical castrates. Because of common marketing strategies, it is important for advantages in cutting yields to span a broad spectrum of slaughter ages and BW. The primary objectives in this study were to evaluate carcass cutting yields, pork quality, belly quality, and bacon processing characteristics of immunologically castrated (IC) male pigs fed a moderate level of distillers dried grains with solubles and slaughtered at either 4 wk (early slaughter group) or 6 wk (late slaughter group) post-second injection. A total of 156 male pigs (physical castrates or IC males) were selected from a population of 1,200 finishing pigs. Data were analyzed with the MIXED procedure of SAS as a split-split plot design. Body weights of IC males were 3.60 kg heavier (P = 0.03) than physical castrates when slaughtered at 4 wk post-second injection and 7.52 kg heavier (P < 0.0001) than physical castrates when slaughtered at 6 wk post-second injection. Because of a lack of interaction (P > 0.05) between sex and time of slaughter post-second injection, some response variables were pooled. Hot carcass weights were not different (P = 0.57) between physical castrates (91.98 kg) and IC males (92.52 kg). There was a 2.77 percentage unit decrease (P < 0.001) in dressing percentage of IC males (71.78%) compared with physical castrates (74.55%). Lean cutting yields of IC males were 2.62 percentage units greater (P < 0.0001) than physical castrates and carcass cutting yields were 2.27 percentage units greater (P < 0.0001) for IC males when compared with physical castrates. There were no differences between IC males and physical castrates for shear force (P = 0.09), ultimate pH (P = 0.57), objective color (P ? 0.31), subjective color score (P = 0.64), or drip loss (P = 0.30). Bellies from IC males were thinner (P = 0.01) and had narrower belly flops (P < 0.0001) than bellies from physical castrates. There were no differences (P = 0.74) in cured belly cooked yield between IC males and physical castrates. Overall, immunological castration improved cutting yields, did not affect pork quality, made fresh bellies thinner, and did not affect cured belly characteristics when pigs were fed a moderate level of distillers dried grains with solubles during the finishing phase of production. PMID:21890506

  15. 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. PMID:22750493

  16. Time-frequency characteristics and dynamics of sleep spindles in WAG/Rij rats with absence epilepsy.

    PubMed

    Sitnikova, Evgenia; Hramov, Alexander E; Grubov, Vadim; Koronovsky, Alexey A

    2014-01-16

    In rat models of absence epilepsy, epileptic spike-wave discharges appeared in EEG spontaneously, and the incidence of epileptic activity increases with age. Spike-wave discharges and sleep spindles are known to share common thalamo-cortical mechanism, suggesting that absence seizures might affect some intrinsic properties of sleep spindles. This paper examines time-frequency EEG characteristics of anterior sleep spindles in non-epileptic Wistar and epileptic WAG/Rij rats at the age of 7 and 9 months. Considering non-stationary features of sleep spindles, EEG analysis was performed using Morlet-based continuous wavelet transform. It was found, first, that the average frequency of sleep spindles in non-epileptic Wistar rats was higher than in WAG/Rij (13.2 vs 11.2 Hz). Second, the instantaneous frequency ascended during a spindle event in Wistar rats, but it was constant in WAG/Rij. Third, in WAG/Rij rats, the number and duration of epileptic discharges increased in a period between 7 and 9 months of age, but duration and mean value of intra-spindle frequency did not change. In general, age-dependent aggravation of absence seizures in WAG/Rij rats did not affect EEG properties of sleep spindles; it was suggested that pro-epileptic changes in thalamo-cortical network in WAG/Rij rats might prevent dynamic changes of sleep spindles that were detected in Wistar. PMID:24231550

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

    NASA Astrophysics Data System (ADS)

    Namys?owska-Wilczy?ska, 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+ ion content. The kriging estimation results were used to determine the levels of elevated values Z* of the water quality parameters in the years 2007 ÷ 2011 and to forecast these values for the years 2012 ÷ 2014. The maximum values Z* of the quality parameters were stated for the years: 2007, 2008 ÷ 2009 and 2012 (the decreasing trend in Fe iron content averages Z* variation towards the year 2012, the increasing trend in Mn content averages Z* variation towards the year 2012 and the increasing trend in NH4+ ion content averages Z* variation towards the years 2008÷2009 and then the decreasing trend towards the year 2012). Thanks to the (3D) geostatistical model of quality variability parameters, precise characteristics of the studied parameters throughout the Klodzko city water supply system for the years 2007 ÷ 2011 have been obtained.

  18. Stability criterion of angle tracking systems in real time under conditions of interference distorting direction finding characteristic

    Microsoft Academic Search

    Evgeny Markin

    2010-01-01

    The article considers stability of the automatic angle tracking systems under conditions of interference distorting direction finding characteristic. The automatic angle tracking is described in the system state. Since the estimation of the modulus of continuity in the theorem on continuous dependence of the characteristic roots on matrix elements accepts very significant roots change under small matrix perturbations of the

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

    Microsoft Academic Search

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

    2010-01-01

    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)

  20. 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.

  1. 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

  2. Characteristics of the maritime periods during Gosan 2006 and Gosan 2008 The time periods when the HYSPLIT (Draxler et al., 2002) back trajectories for 500, 1000 and 1500

    E-print Network

    Meskhidze, Nicholas

    Characteristics of the maritime periods during Gosan 2006 and Gosan 2008 The time periods when no contact with land surface for five days were classified as maritime. Such periods were found only during Gosan 2006 and Gosan 2008: for Gosan 2006, 15:00, Aug. 21 - 03:00, Aug. 22 (Maritime 1) and 21:00, Aug

  3. Influence of static injection timing on combustion, emission and performance characteristics of DI diesel engine fuelled with honne oil methyl ester

    Microsoft Academic Search

    Venkanna Krishnamurthy Belagur; Venkataramana Reddy Chitimini

    2012-01-01

    This study is aimed to investigate experimentally the combustion, exhaust emissions and performance characteristics of a direct injection (DI) diesel engine, typically used in the agricultural sector, when fuelled with neat diesel (ND), and abundantly available but untapped honne oil methyl ester (HOME) is used in diesel engines. The static injection timing (SIT) is varied from 23 crank angle (CA)

  4. Influence of static injection timing on combustion, emission and performance characteristics of DI diesel engine fuelled with honne oil methyl ester

    Microsoft Academic Search

    Venkanna Krishnamurthy Belagur; Venkataramana Reddy Chitimini

    2011-01-01

    This study is aimed to investigate experimentally the combustion, exhaust emissions and performance characteristics of a direct injection (DI) diesel engine, typically used in the agricultural sector, when fuelled with neat diesel (ND), and abundantly available but untapped honne oil methyl ester (HOME) is used in diesel engines. The static injection timing (SIT) is varied from 23 crank angle (CA)

  5. Time response characteristics of an oxide-confined GaAs /AlGaAs resonant cavity-enhanced photodetector

    NASA Astrophysics Data System (ADS)

    Estacio, E.; Alonzo, C.; Samson, A.; Garcia, A.; Somintac, A.; Salvador, A.

    2004-10-01

    This work compares the speed characteristics of a ˜135-?m-diam GaAs /AlGaAs resonant cavity-enhanced (RCE) detector-emitter device with its laterally oxidized ˜80-?m-diam counterpart. The full width at half-maximum of the photocurrent spectrum exhibited no degradation in wavelength selectivity. Moreover, oxide confinement caused no current bottleneck that was inferred to adversely affect the device speed. The measured pulse responses were 65 and 75ps for the unoxidized and oxidized devices, respectively. Oxide-confined RCE photodetectors show relevant application in concentric hybrid RCE vertical cavity laser devices, this work deals with the speed characteristics of laterally oxidized resonant cavity-enhanced devices.

  6. The Eect of Exposure Time to Clean Room Air on Characteristic Parameters of Au \\/Epilayer n-Si Schottky Diodes

    Microsoft Academic Search

    M. Saðlam; Ç. Nuhoðlu; E. Ayyildiz; A. Türüt; H. A. Çetýnkara

    1998-01-01

    A study has been made on determination and comparison of current-voltage (I-V) and capacitance-voltage (C-V) characteristics parameters of Au\\/n-Si Schottky barrier diodes (SBDs) with and without thin native oxide layer fabricated on n-type Si grown by LPE (Liquid-phase Epitaxy) technique. The native oxide layer with different thicknesses on chemically cleaned on Si surface were obtained by exposing the surfaces to

  7. 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)

  8. Short-term peak demand forecasting in fast developing utility with inherit dynamic load characteristics; Application of classical time-series methods

    SciTech Connect

    Barakat, E.H.; Qayyum, M.A.; Hamed, M.N.; Al Rashed, S.A. (Saudi Consolidated Electric Co., P.O. Box 57, Al Riyadh 11411 (SA))

    1990-08-01

    The intrinsic uncertainties associated with demand forecasting become more acute when it is required to provide an invaluable dimension to the decision making process in a period characterized by fast and dynamic changes. In this paper, estimates of the peak demand, pertaining to a typical fast growing system with inherit dynamic load characteristics, have been derived from three classical time-series forecasting methods. These demand estimates are compared with corresponding actual values.

  9. Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: Influence of lapse time of reaction

    Microsoft Academic Search

    Kyong-Hwan. Lee; Dae-Hyun Shin

    2007-01-01

    Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene=3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350°C) and high (400°C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid

  10. 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

    NASA Astrophysics Data System (ADS)

    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.

  11. 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.

  12. 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.

  13. Do Diligent Students Perform Better? Complex Relations between Student and Course Characteristics, Study Time, and Academic Performance in Higher Education

    ERIC Educational Resources Information Center

    Masui, Chris; Broeckmans, Jan; Doumen, Sarah; Groenen, Anne; Molenberghs, Geert

    2014-01-01

    Research has reported equivocal results regarding the relationship between study time investment and academic performance in higher education. In the setting of the active, assignment-based teaching approach at Hasselt University (Belgium), the present study aimed (a) to further clarify the role of study time in academic performance, while taking…

  14. Relative timing characteristics of the one pulse per second (1PPS) output pulse of three GPS receivers

    Microsoft Academic Search

    P. J. Mumford

    2003-01-01

    The atomic clocks orbiting around the earth in GPS satellites can be utilised by anyone to obtain accurate timing. All that is required is an inexpensive GPS receiver and a clear view of the sky. This has enabled a revolution in applications requiring synchronization such as cellular networks, telecommunications timing, digital TV and radio transmission, calibration laboratory systems and the

  15. Characteristic time series and operation region of the system of two tank reactors (CSTR) with variable division of recirculation stream

    Microsoft Academic Search

    Henryk Merta

    2006-01-01

    The paper deals with a system of a cascade of two tank reactors, being characterized by the variable stream of recirculating fluid at each stage. The assumed mathematical model enables one to determine the system’s dynamics for the case when there is no time delay and for the opposite case. The time series of the conversion degree and of the

  16. 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...

  17. 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

  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. Performance characteristics of a real-time direct deposition supercritical fluid chromatography-Fourier transform infrared spectrophotometry system

    Microsoft Academic Search

    Kelly L Norton; Peter R Griffiths

    1995-01-01

    In this paper, real-time, on-line measurements of direct deposition capillary supercritical fluid chromatography-Fourier transform infrared spectra of subnanogram quantities of analytes is demonstrated for the first time. The minimum identifiable quantity for caffeine (a strong infrared absorber) obtained with this interface was 600 pg (injected) and 1–10 ng for weaker absorbers. Spectra over the entire mid-infrared region of compounds separated

  20. Numerical and experimental studies of mixing characteristics in a T-junction microchannel using residence-time distribution

    Microsoft Academic Search

    John T. Adeosun; Adeniyi Lawal

    2009-01-01

    The mixing behavior in laminar flow in microchannels is investigated using numerical and experimental approaches. The concept of residence-time distribution (RTD) was applied to indirectly characterize flow and mixing in a T-junction microchannel chosen as a model microchannel mixer\\/reactor. The residence-time distribution used in this study, although a well-known method for characterizing mixing behavior in conventional macro mixers\\/reactors, is still

  1. 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.

  2. Characteristic precipitation patterns of El Niño/La Niña in time-variable gravity fields by GRACE

    NASA Astrophysics Data System (ADS)

    Morishita, Yu; Heki, Kosuke

    2008-08-01

    El Niño and La Niña are known to bring about characteristic patterns of anomalous precipitation in various regions of the world. We extracted temporary and regional gravity changes from monthly gravity fields recovered by the GRACE satellites, and converted them to the changes in surface mass, possibly ground or subsurface water in land area. Such mass changes in the 2006-2007 El Niño and 2005-2006 La Niña episodes agreed well with precipitation anomaly patterns inferred from meteorological records in tens of past such episodes. We further compared them with anomalies of soil moisture numerically simulated by integrating monthly precipitation and evapotranspiration. They agree quantitatively with the GRACE data, suggesting that temporal changes in terrestrial water storage in low-latitude region are largely governed by precipitation. This study demonstrates the potential of satellite gravimetry as a sensor of inter-annual climate changes.

  3. 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.

  4. 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.

  5. Real-time monitoring of the mitophagy process by a photostable fluorescent mitochondrion-specific bioprobe with AIE characteristics.

    PubMed

    Zhang, Weijie; Kwok, Ryan T K; Chen, Yilong; Chen, Sijie; Zhao, Engui; Yu, Chris Y Y; Lam, Jacky W Y; Zheng, Qichang; Tang, Ben Zhong

    2015-05-14

    An isothiocyanate-functionalized tetraphenylethene is synthesized and used as a fluorescent bioprobe for mitochondrion imaging with high specificity and photostability. The covalent conjugation of the bioprobe to mitochondrial proteins endows it with high resistance to microenvironmental changes, enabling it for real-time monitoring of mitophagy. PMID:25939788

  6. Influence of Extraction Time and Different Sage Varieties on Sensory Characteristics of a Novel Functional Beverage by RSM

    Microsoft Academic Search

    B. Özcelik; A. Karadag; T. Cinbas; P. Yolci

    2009-01-01

    An optimized formulation was developed for the preparation of an `ice-sage tea' which might be considered to be a new healthy functional product and designed as an alternative to other cold-served drinks in the market. A central composite design was used for modeling of the experiment with two independent variables (extraction time and blending ratios of two different sage varieties:

  7. High-frequency forward scattering from the sea surface: the characteristic scales of time and angle spreading

    Microsoft Academic Search

    Peter H. Dahl

    2001-01-01

    Forward scattering from the sea surface is discussed in the contest of a forward bounce path, or channel, through which high-frequency sound energy is transmitted. Such a channel might be used in an underwater communication or imaging task. Both time and angle spreading are inherent to the process of forward scattering by a roughened sea surface. Spreading in each domain

  8. 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,…

  9. Influence of milk type, coagulant, salting procedure and ripening time on the final characteristics of Picante cheese

    Microsoft Academic Search

    A. Cristina Freitas; F. Xavier Malcata

    1996-01-01

    Picante da Beira Baixa cheese is a hard, spicy, salty traditional cheese with a minimum ripening time of 120 d that is manufactured in Portugal at a farm level only. The purpose of this work was to study the influence of several manufacturing conditions (viz. mixture of ovine and caprine milks, source of coagulant, level of NaCl addition, and duration

  10. Estimating forest structural characteristics with airborne lidar scanning and a near-real time profiling laser systems 

    E-print Network

    Zhao, Kaiguang

    2009-05-15

    -the-fly airborne profiling LiDAR system to inventory regional forest resources in real- or near real- time. The system was developed based on an existing portable airborne laser system (PALS) that has been previously assembled at NASA by Dr. Ross Nelson. Key issues...

  11. Modulated drug release using iontophoresis through heterogeneous cation-exchange membranes. 2. Influence of cation-exchanger content on membrane resistance and characteristic times.

    PubMed

    Schwendeman, S P; Amidon, G L; Labhasetwar, V; Levy, R J

    1994-10-01

    An implantable drug delivery method using iontophoresis through cation-selective membranes was further developed. Heterogeneous cation-exchange membranes (HCMs) were prepared by mixing conductive sulfonated polystyrene beads into a nonconductive silicone rubber matrix. The membrane resistivity and lag time to steady-state transport of two salts, (+/-)-phenylpropanolamine hydrochloride (PPA) and NaCl, were evaluated during constant current iontophoresis at 37 degrees C as a function of the resin content in the HCMs. A continuous decline in membrane resistivity was observed as fractional resin content (l) was increased over the entire usable region (l = 0.29-0.52), a characteristic that could be described by a percolation scaling law (for an infinite lattice, 3-D geometry). Morphological analysis of the membranes before and after swelling strongly suggested that the conducting clusters of resin beads form during the swelling period prior to use. The response time to steady-state transport of PPA into NaCl during a 40 microA constant current (0.27 cm2) was found to increase with increasing l, but not without decreasing the permselectivity of the HCMs for the drug cation. The lag time effect could be explained in terms of an increasing number of fixed charge groups in the membrane available for transport (mfcA), which was derived from a macroscopic mass balance model. The values of mfcA were also found to be related to the characteristic time of diffusion in a homogeneous transport projection of the HCM (or an effective medium), an essential parameter for future non-steady-state simulations. The characteristic time of diffusion was found to be invariant with changing resin content, suggesting that the membranes are fairly nontortuous (ca. seven beads thick). By assuming that the thickness of the HCM approaches the thickness of its homogeneous projection, an expression was derived to predict lag time to steady-state PPA transport requiring resistance measurements only (provided that the resin capacity is known). There was excellent agreement between the theoretical and experimental lag time to steady-state transport of PPA (r = 0.96, p < 0.001), further implicating the role of membrane resistance in the bi-ionic system. These modeling approaches have already found utility in iontophoretic implant design for prevention of cardiac arrhythmias and may be valuable in future non-steady-state analysis to further develop on-line detection-implant response technology. PMID:7884674

  12. Time characteristics of the effect of alcohol cessation on the risk of stomach cancer – a meta-analysis

    PubMed Central

    2013-01-01

    Background In the Bagnardi et al. (2001) meta-analysis, it was found that alcohol consumption increases the risk of stomach cancer (OR?=?1.32 for heavy drinkers). However, it is unknown if drinking cessation reverses this alcohol-elevated risk. Methods A systematic literature review was performed to provide the information for a meta-analysis where the dose-risk trend was estimated for years since drinking cessation and the risk of stomach cancer. A random effect generalised least squares model for trend estimation was used, employing study characteristics to control for heterogeneity. Results Nineteen observational studies were identified in the literature review, of which five studies quantified duration of cessation and risk of stomach cancer, giving a total of 1947 cancer cases. No significant effect of drinking cessation on the risk of stomach cancer could be found (OR?=?0.99 CI: 0.97-1.02). Conclusions This result should be interpreted with caution due to the limited number of studies in this area. Recent findings suggest a link between heavy drinking and stomach cancer, especially gastric noncardia, but not for moderate drinking. Since all but one of the included studies in this meta-analysis failed to control for consumption level, the current study could not test if the risk decline following drinking cessation differs between moderate and high consumers. PMID:23786883

  13. Visualization of the laminar-turbulent transition in the flow over an airfoil using the smoke-wire technique

    NASA Technical Reports Server (NTRS)

    Batill, S. M.; Mueller, T. J.

    1980-01-01

    A flow visualization technique, referred to as the smoke-wire, was used for visualization of the transition of the free shear layer associated with the laminar separation bubble of a NACA 66 sub 3-018 airfoil section at low Reynolds number (50,000-130,000). The smoke-wire technique allows the introduction of fine smoke streaklines into the flow field through the electrical resistive heating of a very fine wire which has been coated with oil and which is located upstream from the leading edge of the airfoil section. Streakline data were collected using both high speed still and motion picture photography.

  14. A Methodology for Flight-Time Identification of Helicopter-Slung Load Frequency Response Characteristics Using CIFER

    NASA Technical Reports Server (NTRS)

    Sahai, Ranjana; Pierce, Larry; Cicolani, Luigi; Tischler, Mark

    1998-01-01

    Helicopter slung load operations are common in both military and civil contexts. The slung load adds load rigid body modes, sling stretching, and load aerodynamics to the system dynamics, which can degrade system stability and handling qualities, and reduce the operating envelope of the combined system below that of the helicopter alone. Further, the effects of the load on system dynamics vary significantly among the large range of loads, slings, and flight conditions that a utility helicopter will encounter in its operating life. In this context, military helicopters and loads are often qualified for slung load operations via flight tests which can be time consuming and expensive. One way to reduce the cost and time required to carry out these tests and generate quantitative data more readily is to provide an efficient method for analysis during the flight, so that numerous test points can be evaluated in a single flight test, with evaluations performed in near real time following each test point and prior to clearing the aircraft to the next point. Methodology for this was implemented at Ames and demonstrated in slung load flight tests in 1997 and was improved for additional flight tests in 1999. The parameters of interest for the slung load tests are aircraft handling qualities parameters (bandwidth and phase delay), stability margins (gain and phase margin), and load pendulum roots (damping and natural frequency). A procedure for the identification of these parameters from frequency sweep data was defined using the CIFER software package. CIFER is a comprehensive interactive package of utilities for frequency domain analysis previously developed at Ames for aeronautical flight test applications. It has been widely used in the US on a variety of aircraft, including some primitive flight time analysis applications.

  15. An experimental approach to estimate real-time characteristic of PROFINET IO versus PROFIBUS DP V2

    Microsoft Academic Search

    P. Ferrari; A. Flammini; D. Marioli; A. Taroni

    2006-01-01

    This paper investigates performances of PROFINET IO Class 1, based on Ethernet@100Mbit\\/s, as a replacement of PROFIBUS DP V2, based on RS485 @ 12Mbit\\/s, for the realization of time-critical and isochronous systems. In this work, two test systems have been built. In the first one, the same experimental setup with the same application has been implemented using PROFINET and PROFIBUS

  16. Characteristics of official and experimental GRACE time series by GFZ and CSR - with applications to polar signals

    NASA Astrophysics Data System (ADS)

    Horvath, Alexander; Horwath, Martin; Pail, Roland

    2014-05-01

    The Release-05 monthly solutions by the three centers of the GRACE Science and Data System are a significant improvement with respect to the previous Release 4. Meanwhile, previous assessments have revealed different noise levels between the solutions by CSR, GFZ and JPL, and also different amplitudes of interannual signal in the solutions by GFZ as compared to the two other centers. Encouraged by the science community, GFZ and CSR have kindly provided additional sets of time series. GFZ has reprocessed the RL05 monthly solutions (up to degree and order 90) with revised processing. CSR has made available monthly solutions with standard processing up to degree and order 96, in addition to their solutions up to degree and order 60. We compare these different time series with respect to their signal and noise content and analyze them on global and regional scale. For the regional scale our special interest is paid on Antarctica and on revealing polar signals such as ice mass trends and GIA. Following the necessity of destriping, an optimal choice for the setup of the Swenson & Wahr filter approach is evaluated to adapt to the specific signal and noise level in Antarctica. Furthermore we analyze the potential benefit of mixed time series solutions in order to combine the strengths of the solutions available. Concerning the question for an optimal maximum degree we suggest that for resolving large polar ice mass changes, it would be beneficial to provide gravity field variations even beyond degree 90.

  17. 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.

  18. Improvements of Real Time First Motion Focal Mechanism and Noise Characteristics of New Sites at the Puerto Rico Seismic Network

    NASA Astrophysics Data System (ADS)

    Williams, D. M.; Lopez, A. M.; Huerfano, V.; Lugo, J.; Cancel, J.

    2011-12-01

    Seismic networks need quick and efficient ways to obtain information related to seismic events for the purposes of seismic activity monitoring, risk assessment, and scientific knowledge among others. As part of an IRIS summer internship program, two projects were performed to provide a tool for quick faulting mechanism and improve seismic data at the Puerto Rico Seismic Network (PRSN). First, a simple routine to obtain a focal mechanisms, the geometry of the fault, based on first motions was developed and implemented for data analysts routine operations at PRSN. The new tool provides the analyst a quick way to assess the probable faulting mechanism that occurred while performing the interactive earthquake location procedure. The focal mechanism is generated on-the-fly when data analysts pick P wave arrivals onsets and motions. Once first motions have been identified, an in-house PRSN utility is employed to obtain the double couple representation and later plotted using GMT's psmeca utility. Second, we addressed the issue of seismic noise related to thermal fluctuations inside seismic vaults. Seismic sites can be extremely noisy due to proximity to cultural activities and unattended thermal fluctuations inside sensor housings, thus resulting in skewed readings. In the past, seismologists have used different insulation techniques to reduce the amount of unwanted noise that a seismometers experience due to these thermal changes with items such as Styrofoam, and fiber glass among others. PRSN traditionally uses Styrofoam boxes to cover their seismic sensors, however, a proper procedure to test how these method compare to other new techniques has never been approached. The deficiency of properly testing these techniques in the Caribbean and especially Puerto Rico is that these thermal fluctuations still happen because of the intense sun and humidity. We conducted a test based on the methods employed by the IRIS Transportable Array, based on insulation by sand burial of the sensor. Two Guralps CMG-3T's connected to RefTek's 150 digitizers were used at PRSN's MPR site seismic vault to compare the two types of insulation. Two temperature loggers were placed along each seismic sensor for a period of one week to observe how much thermal fluctuations occur in each insulation method and then compared its capability for noise reduction due to thermal fluctuations. With only a single degree Celsius fluctuation inside the sand (compared to almost twice that value for the foam) the sensor buried in sand provided the best insulation for the seismic vault. In addition, the quality of the data was analyzed by comparing both sensors using PQLX. We show results of this analysis and also provide a site characteristic of new stations to be included in the daily earthquake location operations at the PRSN.

  19. 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., II; 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.

  20. 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).

  1. 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.

  2. Height and time characteristics of seasonal and diurnal variations in PMWE based on 1 year observations by the PANSY radar (69.0°S, 39.6°E)

    NASA Astrophysics Data System (ADS)

    Nishiyama, Takanori; Sato, Kaoru; Nakamura, Takuji; Tsutsumi, Masaki; Sato, Toru; Kohma, Masashi; Nishimura, Koji; Tomikawa, Yoshihiro; Ejiri, Mitsumu K.; Tsuda, Takuo T.

    2015-04-01

    We report height and time variations in polar mesosphere winter echoes (PMWE) based on the Program of the Antarctic Syowa mesosphere-stratosphere-troposphere/incoherent scatter (PANSY) radar observations. PMWE were identified for 110 days from March to September 2013. PMWE occurrence frequency increased abruptly in May when two solar proton events occurred. PMWE were also observed even during periods without any solar proton events, suggesting that a possible cause of the PMWE is ionization by energetic electron precipitations. The monthly mean PMWE characteristics showed that occurrence of PMWE were mainly restricted to sunlit time. This fact indicates that electrons detached from negatively charged particles play an important role. While PMWE below 72 km in altitude completely disappeared before sunset, it was detected above that altitude for a few hours even after sunset. This height dependence in the altitude range of 60-80 km can be explained qualitatively by empirical effective recombination rates.

  3. Time-dependent effects of isoflurane and dexmedetomidine on functional connectivity, spectral characteristics, and spatial distribution of spontaneous BOLD fluctuations

    PubMed Central

    Magnuson, Matthew Evan; Thompson, Garth John; Pan, Wen-Ju; Keilholz, Shella Dawn

    2015-01-01

    Anesthesia is often necessary to perform fMRI experiments in the rodent model; however, commonly used anesthetic protocols may manifest changing brain conditions over the duration of the study. This possibility was explored in the current work. Eleven rats were anesthetized with 2% isoflurane anesthesia; four rats were anesthetized for a short period (30min, simulating induction and fMRI setup) and seven rats were anesthetized for a long period (3 h, simulating surgical preparation). Following the initial anesthetic period, isoflurane was discontinued, and a dexmedetomidine bolus (0.025 mg/kg) and continuous subcutaneous infusion (0.05 mg/kg/h) were administered. Blood-oxygen-level dependent resting state imaging was performed every 30 min from 0.75 h post dexmedetomidine bolus until 5.75 h post-bolus. Evaluation of power spectra obtained from time courses in the primary somatosensory cortex revealed, in general, a monotonic increase in low-frequency power (0.05–0.3 Hz) in both groups over the duration of resting state imaging. Greater low-band spectral power (0.05–0.15 Hz) is present in the short isoflurane group for the first 2.75 h, but the spectra become highly uniform at 3.25 h. The emergence of a ~0.18 Hz peak, beginning at the 3.75 h time point, exists in both groups and evolves similarly, increasing in strength as the duration of dexmedetomidine sedation (and time since isoflurane cessation) extends. In the long isoflurane group only, bilateral functional connectivity strengthens with anesthetic duration, and correlation is linearly linked to low-band spectral power. Convergence of connectivity and spectral metrics between the short and long isoflurane groups occurs at ~3.25 h, suggesting the effects of isoflurane have subsided. Researchers using dexmedetomidine following isoflurane for functional studies should be aware of the duration specific effects of the pre-scan isoflurane durations as well as the continuing influences of long-term imaging under dexmedetomidine. PMID:24449532

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

    PubMed

    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 -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. PMID:25117078

  5. 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.

  6. Over time and space changing characteristics of estuarine suspended particles in the German Weser and Elbe estuaries

    NASA Astrophysics Data System (ADS)

    Papenmeier, Svenja; Schrottke, Kerstin; Bartholomä, Alexander

    2014-01-01

    Fine cohesive, suspended sediments appear in all estuarine environments in a predominately flocculated state. The transport and deposition of these flocs is influenced by their in-situ and primary particle size distribution. Especially the size of the inorganic particles influences the density and hence the settling velocity of the flocculated material. To describe both the changes in primary particle size of suspended particulate matter as well as the variability of floc sizes over time and space, the data of In-Situ Particle-Size Distributions (ISPSDs), Primary Particle Size Distributions (PPSDs) and Suspended Sediment Concentrations (SSCs) were collected. For this, Laser In-Situ Scattering and Transmissiometry (LISST) measurements as well as the water samples were collected in the German Elbe and Weser estuaries, covering seasonal variability of the SSC. The data of the ISPSDs show that the inorganic and organic Suspended Particulate Matter (SPM), as found in the Elbe and Weser estuaries, mostly appears in a flocculated state. The substrate for organic matter is mainly imported from the seaside and transported into the estuaries as indicated by an upstream decrease of the amount of fine particles. In winter, when the freshwater discharge is high, different PPSDs are found in the case of the Elbe estuary in the Turbidity Maximum Zone (TMZ) as well as in the landward and in the seaward sections close to the TMZ. In summer, the distance between the seaward and the landward section is too low to obtain an individual PPSD within the Elbe TMZ. A missing correlation between the PPSD and ISPSD shows that the inorganic constituents do not have an influence on the in-situ floc size. Although flocs aggregate and disaggregate over a tidal cycle and with changing SSC, they do not change their PPSD. The microflocs are therefore strong enough to withstand further breakage into their inorganic constituents.

  7. Impact of patient characteristics, complications, and facility volume on the costs and time of cardiac catheterization and coronary angioplasty in 70 catheterization laboratories.

    PubMed

    Cohen, D J; Becker, E R; Culler, S D; Ellis, S; Green, L M; Schnitzler, R N; Simon, A W; Weintraub, W S

    2000-09-15

    Although over 1 million procedures are performed in cardiac catheterization laboratories (CCLs) annually, little comparative data exist on costs or resource use in these settings. In this study, data from 70 CCLs were used to profile CCL times and total direct costs for 2 high-volume procedures: left heart catheterization (LHC) and percutaneous transluminal coronary angioplasty (PTCA) with or without stent placement. In total, 70,677 consecutive patient examinations for a 12-month period from January 1, 1998 to December 31, 1998 were analyzed. For LHC mean total direct costs averaged $306, whereas for PTCA catheterization laboratory costs averaged $3,172. The average total times for these procedures were 63 and 108 minutes, respectively. Seventy-two percent of the PTCA patients underwent coronary stenting with an associated incremental cost of $1,244. By multivariate linear regression, baseline patient characteristics such as age, gender, and clinical factors had little impact on total time and total costs. The major determinants of CCL time and cost were procedural factors (e.g., number and type of interventions) and in-lab complications, including profound hypotension, abrupt vessel closure, and emergency bypass surgery. Using facility procedure volume as a proxy for potential economies of scale, we found no relation between CCL volume and total direct CCL costs. There did appear to be a significant inverse relation between facility volume and total procedural time with CCLs that performed the highest volumes of LHC and PTCA procedures saving an average of 5 to 9 minutes per procedure. These findings may be useful in defining specific time and cost benchmarks for these commonly performed procedures and serve to underscore the critical role of reducing complications in both quality improvement and cost-saving efforts. PMID:10980207

  8. Times

    NSDL National Science Digital Library

    In this activity learners explore the connections of digital time displays with numeric and geometric properties. Students look for times that have bilateral or rotational symmetry, or have a certain digital sum, etc. Ideas for implementation, extension and support are included.

  9. Study on hydrofluoric acid-based clad etching and chemical sensing characteristics of fiber Bragg gratings of different reflectivity fabricated under different UV exposure times

    NASA Astrophysics Data System (ADS)

    Kumar, Jitendra; Mahakud, Ramakant; Prakash, Om; Dixit, Sudhir Kumar

    2013-05-01

    An experimental study on hydrofluoric acid (HF)-based clad etching and chemical sensing characteristics of fiber Bragg gratings (FBG) of different reflectivity fabricated under different UV (255 nm) exposure times is presented. Two FBGs of reflectivity 11% and 93% were inscribed by phase mask-based exposition of the photosensitive fibers by a 5.5 kHz repetition rate of 255 nm UV pulses for 15 s and 10 min, respectively. These two FBGs, employed in an HF-based clad etching experiment, revealed a much higher etching rate of 2.03 ?m/min for the grating of reflectivity 11% as compared to 1.69 ?m/min for the grating of reflectivity 93%. The performance of these etched FBGs were also studied for refractive index sensing of the chemicals ethanol and ethylene glycol under different fiber etching times, hence of different residual cladding diameter. It was observed that the same refractive index sensitivity for both the chemicals could be achieved under smaller etching time, i.e., larger residual cladding diameter, for the FBG with lower reflectivity. This differentiating behavior of FBGs under etching and sensing may be linked to the different degree of densification in fused silica fiber cladding under different UV fluence exposures.

  10. 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.

  11. Direct observations in the dusk hours of the characteristics of the storm-time ring current particles during the beginning of magnetic storms

    NASA Technical Reports Server (NTRS)

    Smith, P. H.; Hoffman, R. A.

    1973-01-01

    The characteristic features of the initial enhancement of the storm-time ring current particles in the evening hours are consistent with flow patterns resulting from a combination of inward convection, gradient drift, and corotation which carries plasma sheet protons into low L-values near midnight and the higher energy proton component into the plasmasphere and through the evening hours. Data from four magnetic storms during the early life of Explorer 45, when the local time of apogee was in the afternoon and evening hours, show that protons with lower magnetic moments penetrate deeper into the magnetosphere until a low limit, determined by the corotation and gradient drift forces, is reached. Such particle motions produce the stable energy dependent inner boundary of the ring current protons inside the plasmapause in the dusk sector and also provide the mechanism for energy injection into the ring current region. From the analyses of the pitch angle distributions it is evident that charge exchange and wave particle interactions are not the dominant causes of this inner boundary.

  12. Characteristics of individual rain events and its dependency on the minimum inter-event time in a dry desert area in north China

    NASA Astrophysics Data System (ADS)

    Wang, X.

    2009-04-01

    The rain event characteristics was analysed using a pluviograph record of 2008 from an arid desert area of Shapotou in the Tengger Desert, China. Changing the minimum inter-event time (MIT) from 30 min to 24 h alters the number of rain events from 72 to 21. The mean rain rate declines from 0.85 mm h-1 to 0.4 mm h-1, and the geometric mean event duration rises from 0.64 h to 5.04 h. The number of rain events, the mean rain rate, and the geometric mean event duration differed under different criteria of individual rain depth (e.g., 0.1, 0.5, 1.0, 5.0 mm), except that for an individual rain depth of 0.5, 1.0, and 5.0 mm, the features (the number of rain events, the mean rain rate, and the geometric mean event duration) mentioned above are identical for MIT=2 and 3 h. Therefore, there is no need for further identification to set MIT at two or three hours in this specific arid desert area. This wide variation in the properties of rain events indicates that more attention needs to be paid to the selection and reporting of event criteria in studies that adopt event-based data analysis. The selection of a MIT criterion is shown to involve a compromise between the independence of widely-spaced events and their increasingly variable intra-event characteristics (Dunkerley, Hydrological Processes, 2008, 22(26): 5024-5036).

  13. 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 (?2) and new non-Gaussian (?) 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. PMID:25612718

  14. 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

    NASA Astrophysics Data System (ADS)

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-01

    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 (?2) and new non-Gaussian (?) 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.

  15. [Establishment of a complete daily time series of precipitation and its change characteristics in forest region of eastern China during 1961-2010].

    PubMed

    Chi, Ya-fei; Zhang, Cheng-yi; Liang, Cun-zhu; Hong, Wu

    2013-04-01

    To accurately interpolate the missing precipitation data from meteorological observation stations within a region to obtain a complete precipitation series is of significance in improving the spatial and temporal resolution in analyzing the effects of climate change. By using spatial correlation and stepwise regression techniques, this paper interpolated the missing precipitation data for an individual day or less than 7 days in a month from the 853 meteorological stations in the forest region of Eastern China in 1961-2010, as a consequent establishment of the complete time series precipitation datasets of the observation stations in 1961-2010 established. Based on these, trend analysis approach was applied to analyze the variation characteristics of the annual precipitation, annual precipitation days, and extreme precipitation events in the region in 1961-2010. During the study period, the annual precipitation in the region presented an insignificant increasing trend, with a tendency of 5.58 mm (10 a) -1, but the decadal variation was obvious. The annual precipitation days reduced significantly, while the annual extreme precipitation days and extreme precipitation volumes increased significantly, with a tendency of 0.12 d (10 a) -1 and 10. 22 mm (10 a)-1, respectively. Since the 1990s, the extreme precipitation events became frequently and intensively, and the proportion of the volumes of extreme precipitation to total precipitation increased significantly. Both the extreme precipitation days and the volumes of extreme precipitation had an abrupt change in 1993. PMID:23898664

  16. When holding your horses meets the deer in the headlights: time-frequency characteristics of global and selective stopping under conditions of proactive and reactive control.

    PubMed

    Lavallee, Christina F; Meemken, Marie T; Herrmann, Christoph S; Huster, Rene J

    2014-01-01

    The ability to inhibit unwanted thoughts or actions is crucial for successful functioning in daily life; however, this ability is often impaired in a number of psychiatric disorders. Despite the relevance of inhibition in everyday situations, current models of inhibition are rather simplistic and provide little generalizability especially in the face of clinical disorders. Thus, given the importance of inhibition for proper cognitive functioning, the need for a paradigm, which incorporates factors that will subsequently improve the current model for understanding inhibition, is of high demand. A popular paradigm used to assess motor inhibition, the stop-signal paradigm, can be modified to further advance the current conceptual model of inhibitory control and thus provide a basis for better understanding different facets of inhibition. Namely, in this study, we have developed a novel version of the stop-signal task to assess how preparation (that is, whether reactive or proactive) and selectivity of the stopping behavior effect well-known time-frequency characteristics associated with successful inhibition and concomitant behavioral measures. With this innovative paradigm, we demonstrate that the selective nature of the stopping task modulates theta and motoric beta activity and we further provide the first account of delta activity as an electrophysiological feature sensitive to both manipulations of selectivity and preparatory control. PMID:25540615

  17. The relationship between biological cognitive and psychosocial characteristics of parents and the weight of infant at the time of birth in Isfahan

    PubMed Central

    Talebian, Mohammad Hassan; Afrooz, Gholam Ali; Hooman, Heidar Ali; Aghaei, Asghar

    2013-01-01

    Introduction: The present study was connected in order to evaluate the relationship between biological, cognitive and psychosocial characteristics of mothers and the weight of infant at the time of birth. Materials and Methods: In order to conduct this research a sample of 910 women among recently delivered mothers of Isfahan province in 2009 were selected. From stratified sampling and cluster sampling according to the percentage of population in each of the cities of Isfahan Province was used. The data was gathered with a questionnaire prepared by the researcher in order to evaluate the biological cognitive and psychosocial characteristics of mothers, in addition to the Enrich marital satisfaction test. After collecting data, the analysis of the data was done with SPSS software in two categories of descriptive and inferential statistics by using logistic regression model. Results: The results showed that the prevalence of low weight infants was 9.5 percent and 38.7 percent of pregnancies was unwanted. Twenty-nine percent of mothers had marital dissatisfaction. 15/6 percent of pregnancies were below 20 years old and 22 percent was above of 35 years old. 38.9 percent of mothers were exposed to cigarette smoke. The average of weight gain during pregnancies was 9 kilograms. Thirty three percent of mothers had high blood pressure during pregnancy, 26.7 percent had history of abortion and 31.9 percent had history of bleeding. 23/1percent of women was employed during pregnancy, 19.8 percent gave twin birth and 21/1 percent of parents were relative of each other, 29.7 percent of deliveries were done in cesarean way. Conclusion: The results of this study showed that severe marital dissatisfaction, abnormal blood pressure during pregnancy, being employed during pregnancy, weight gain less than 5 Kg during pregnancy, pregnancy below the age of 20 can meaning fully increase the possibility of low birth weight in infant (?=0.05). The results were consisting with the previous findings and indicated that some of the applicable benefits of this research can be recording of information about each delivery in the whole country with holding training workshops of before and during pregnancy skills by welfare organization. PMID:24251279

  18. 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 scour pool developed at the outlet of the T14 CSO. Reaeration coefficients determined from the field tracer-gas method were compared to values calculated by two other methods, one that is based on theoretical equations using physical properties of the stream as variables and the other that is based on equations using the timing of measured daily maximum DO concentrations in the stream. Reaeration coefficients from the two alternate methods were most similar to values determined from the field tracer-gas method for the upstream portion of the study reach, characterized by free-flowing riffle and pools. Values of reaeration coefficients determined by the tracer-gas method were 2 to 10 times higher than values determined by 2 alternate methods for most subreaches hydraulically affected by man-made structures. In addition to the tracer gas, propane, the gas analysis also included methane, ethane, and ethene, of which only methane was measured in concentrations above a few micrograms per liter. Methane, thought to occur naturally or because of ongoing processes in the stream, was measured in concentrations ranging from 6.6 to 78 micrograms per liter; the concentrations were greatest in sub-reaches dominated by pools.

  19. Estimating the Timing of Long Bone Fractures: Correlation Between the Postmortem Interval, Bone Moisture Content, and Blunt Force Trauma Fracture Characteristics

    Microsoft Academic Search

    Danielle A. M. Wieberg; Daniel J. Wescott

    2008-01-01

    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 mor- phology, and

  20. 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.

  1. Identification of Extreme Events Under Climate Change Conditions Over Europe and The Northwest-atlantic Region: Spatial Patterns and Time Series Characteristics

    NASA Astrophysics Data System (ADS)

    Leckebusch, G.; Ulbrich, U.; Speth, P.

    In the context of climate change and the resulting possible impacts on socio-economic conditions for human activities it seems that due to a changed occurrence of extreme events more severe consequences have to be expected than from changes in the mean climate. These extreme events like floods, excessive heats and droughts or windstorms possess impacts on human social and economic life in different categories such as forestry, agriculture, energy use, tourism and the reinsurance business. Reinsurances are affected by nearly 70% of all insured damages over Europe in the case of wind- storms. Especially the December 1999 French windstorms caused damages about 10 billion. A new EU-founded project (MICE = Modelling the Impact of Climate Ex- tremes) will focus on these impacts caused by changed occurrences of extreme events over Europe. Based upon the output of general circulation models as well as regional climate models, investigations are carried out with regard to time series characteristics as well as the spatial patterns of extremes under climate changed conditions. After the definition of specific thresholds for climate extremes, in this talk we will focus on the results of the analysis for the different data sets (HadCM3 and CGCMII GCM's and RCM's, re-analyses, observations) with regard to windstorm events. At first the results of model outputs are validated against re-analyses and observations. Especially a comparison of the stormtrack (2.5 to 8 day bandpass filtered 500 hPa geopotential height), cyclone track, cyclone frequency and intensity is presented. Highly relevant to damages is the extreme wind near the ground level, so the 10 m wind speed will be investigated additionally. of special interest to possible impacts is the changed spatial occurrence of windspeed maxima under 2xCO2-induced climate change.

  2. Comparison of the physiological responses and time-motion characteristics of young soccer players in small-sided games: the effect of goalkeeper.

    PubMed

    Köklü, Yusuf; Sert, Özcan; Alemdaro?lu, Utku; Arslan, Yunus

    2015-04-01

    The purpose of this study was to investigate the effect of "with goalkeeper" (SSGwith) and "without goalkeeper" (SSGwithout) conditions on players' physiological responses and time-motion characteristics in small-sided games. Sixteen young soccer players (age: 16.5 ± 1.5 years; height: 175.5 ± 5.2 cm; body mass: 63.0 ± 6.9 kg; training experience: 6.3 ± 1.3 years) participated in 2 different 2-a-side, 3-a-side, and 4-a-side games: SSGwith and SSGwithout. The players underwent anthropometric measurements (height and body mass) followed by the Yo-Yo intermittent recovery test (level 1). Then they played 2-a-side, 3-a-side, and 4-a-side SSGwith and SSGwithout soccer-specific SSGs in random order at 2-day intervals. Heart rate (HR) responses and distance covered in different speed zones (walking [WLK, 0-6.9 km·h(-1)], low-intensity running [LIR, 7.0-12.9 km·h(-1)], moderate-intensity running [MIR, 13.0-17.9 km·h(-1)], and high-intensity running [HIR, >18 km·h(-1)]) were measured during the SSGs, whereas the rating of perceived exertion (RPE) and blood lactate (La) were determined at the end of the last bout of each SSG. During the SSGwithout players showed higher %HR, La, and RPE (p ? 0.05), greater distance covered in LIR, MIR, HIR, and total distance (p ? 0.05) compared with the SSGwith during the 2-a-side, 3-a-side, and 4-a-side games. The results of this study suggest that both SSGwith and SSGwithout could be used for the physiological adaptations required for soccer-specific aerobic endurance. However, if coaches want both higher physiological responses and greater distance covered in the intensity running zone from their teams, SSGwithout should be organized. In addition, this study also suggests that smaller format games (i.e., 2-a-side) may promote some anaerobic adaptations for youth soccer players. PMID:23942169

  3. Teacher Characteristics.

    ERIC Educational Resources Information Center

    Darr, Ralph F., Jr.

    This paper focuses primarily on the more prominent teacher characteristics research published in the latter half of the 1980s. Literature on the characteristics of elementary, secondary, and college-level teachers is reviewed. Demographic data suggest that today's public school teachers are older and more experienced, and have more years of…

  4. Dependence of the time- and frequency-domain response of BCI injection probes on the common- mode characteristic impedance of the cable bundle

    Microsoft Academic Search

    James McLean; Robert Sutton

    2010-01-01

    The common-mode characteristic impedance of a typical cable bundle has been suggested to be approximately 150 Ohms. However, standard test fixtures for BCI probes employ 50 Ohm coaxial ports. Here a representative injection probe (transformer) intended for bulk current injection applications is characterized experimentally in the frequency domain using a 2-port vector network analyzer and a standard (50 Ohm) test

  5. Measurement of Sparkover Voltage and Time Lag Characteristics in CF3I-N2 and CF3I-Air Gas Mixtures by using Steep-front Square Voltage

    NASA Astrophysics Data System (ADS)

    Toyota, Hiroyuki; Matsuoka, Shigeyasu; Hidaka, Kunihiko

    A square pulse voltage is useful for studying electrical discharge physics or very fast transient overvoltage issues. This paper describes sparkover voltages and time lag (V-t) characteristics of CF3I gas, which has very low environmental effects and high dielectric strength, and its mixtures with nitrogen gas or air in a very short time range below a microsecond. They are measured by using a steep-front square voltage with a rise time of 16 nanoseconds and a peak value of 200 kilovolts. Pure CF3I gas has 20 % higher dielectric strength than SF6 gas. V-t characteristics of CF3I-N2 or CF3I-air gas mixtures, which contain 60% CF3I gas, are equivalent to those of pure SF6 gas at the same total pressure. A quantitative evaluation of V-t characteristics by the equal area criterion is also performed. The equal area parameter which is obtained by applying a voltage enough high to make the formative time lag dominant should be chosen.

  6. The reverse temper embrittlement characteristics of two sets of CrMo steel high temperature turbine bolts with different service times

    SciTech Connect

    Bulloch, J.H. [Electricity Supply Board, Power Generation, Dublin (Ireland)

    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.

  7. Effect of transit time on characteristics of the output pulse in an actively Q-switched Nd:YVO4 laser with acoustic-optic modulator

    Microsoft Academic Search

    Haikun Zhang; Xiufeng Chen; Feng Yu; Zhongshi Zhang; Shengzhi Zhao

    2008-01-01

    By considering the AO switch as a low speed switch and the AO turnoff time including the transit time of the acousticwave and the electronic turnoff time as well as the Gaussian spatial distribution of the intra-cavity photon density, the coupled equations of a Laser-diode pumped actively Q-switched Nd:YVO4 laser with acoustic-optic modulator are given. By changing the position of

  8. SPECIAL ISSUE DEVOTED TO MULTIPLE RADIATION SCATTERING IN RANDOM MEDIA: Time-domain diffuse optical tomography using analytic statistical characteristics of photon trajectories

    NASA Astrophysics Data System (ADS)

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

    2006-11-01

    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.

  9. 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)

  10. 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].

  11. Characteristics of pressure waves

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Air blast characteristics generated by most types of explosions are discussed. Data cover both negative and positive blast load phases and net transverse pressure as a function of time. The effects of partial or total confinement, atmospheric propagation, absorption of energy by ground shock or cratering, and transmission over irregular terrain on blast wave properties were also considered.

  12. Real-time holographic analysis of the modal and dynamic characteristics of an advanced graphite-epoxy missile flight control structure

    Microsoft Academic Search

    Howard Fein

    1997-01-01

    Holographic Interferometry has been successfully employed to characterize the materials and behavior of diverse types of structures under stress. Specialized variations of this technology have also been applied to define dynamic and vibration related structural behavior. Such applications of holographic technique offer some of the most effective methods of modal and dynamic analysis available. Real-time dynamic testing of the model

  13. Impact of patient characteristics, complications, and facility volume on the costs and time of cardiac catheterization and coronary angioplasty in 70 catheterization laboratories

    Microsoft Academic Search

    David J Cohen; Edmund R Becker; Steven D Culler; Stephen Ellis; LuAnn M Green; Robert N Schnitzler; April W Simon; William S Weintraub

    2000-01-01

    Although over 1 million procedures are performed in cardiac catheterization laboratories (CCLs) annually, little comparative data exist on costs or resource use in these settings. In this study, data from 70 CCLs were used to profile CCL times and total direct costs for 2 high-volume procedures: left heart catheterization (LHC) and percutaneous transluminal coronary angioplasty (PTCA) with or without stent

  14. HEDONIC PRICE ESTIMATION FOR KANSAS WHEAT CHARACTERISTICS

    Microsoft Academic Search

    Juan Andres Espinosa; Barry K. Goodwin

    1991-01-01

    A hedonic price model is applied to a cross-sectional time-series data set of Kansas wheat characteristics. Results indicate that prices received by wheat producers reflect the presence of conventional quality characteristics of wheat and also milling and dough characteristics. Furthermore, the results indicate that the alternative sets of characteristics exhibit quality information that is, to some degree, independent of one

  15. Finite-Difference Time-Domain Analysis of Wavelength-Selective Characteristics in Weighted Acoustooptic Switches for Wavelength-Division-Multiplexed Photonic Routing

    Microsoft Academic Search

    Nobuo Goto; Yasumitsu Miyazaki

    2004-01-01

    Waveguide-type acoustooptic (AO) switches can switch optical waves wavelength-selectively for wavelength-division-multiplexed (WDM) signals. The switches can be expected to be used in WDM photonic networks. In this paper, finite-difference time-domain (FDTD) analysis is presented for wavelength-selective switching with a collinear weighted AO device consisting of an optical directional coupler, input\\/output Y-branches and a tapered surface acoustic wave (SAW) waveguide. The

  16. Real-time numerical simulations and experimental research for the propagation characteristics of shock waves and gas flow during coal and gas outburst

    Microsoft Academic Search

    Kai Wang; Aitao Zhou; Jianfang Zhang; Pin Zhang

    When coal and gas outburst occurs, high-speed gas flow and air shock wave with high kinetic energy could be created. In this paper, the formation process of outburst shock waves and gas flow has been analyzed firstly. Afterwards, the numerical simulation models of the roadways with right-angled intersection have been established, by which real-time simulation of the propagation of outburst

  17. Wentzel-Kramer-Brillouin and finite-difference time-domain analysis of Terahertz band electromagnetic characteristics of target coated with unmagnetized plasma

    Microsoft Academic Search

    Liu Shaobin; Zhou Tao; Liu Meilin; Hong Wei

    2008-01-01

    We investigate computationally the attenuation and reflection of Terahertz (THz) wave using targets coated with plasmas. The simulators are the Wentzel-Kramer-Brillouin (WKB) method and finite-difference time-domain (FDTD) method. The relation between the frequency of the incident electromagnetic (EM) wave and the attenuation caused by unmagnitized plasma is analyzed. The results demonstrate that the amount of absorbed power is a decreasing

  18. Scan-pattern and signal processing for microvasculature visualization with complex SD-OCT: tissue-motion artifacts robustness and decorrelation time - blood vessel characteristics

    NASA Astrophysics Data System (ADS)

    Matveev, Lev A.; Zaitsev, Vladimir Y.; Gelikonov, Grigory V.; Matveyev, Alexandr L.; Moiseev, Alexander A.; Ksenofontov, Sergey Y.; Gelikonov, Valentin M.; Demidov, Valentin; Vitkin, Alex

    2015-03-01

    We propose a modification of OCT scanning pattern and corresponding signal processing for 3D visualizing blood microcirculation from complex-signal B-scans. We describe the scanning pattern modifications that increase the methods' robustness to bulk tissue motion artifacts, with speed up to several cm/s. Based on these modifications, OCT-based angiography becomes more realistic under practical measurement conditions. For these scan patterns, we apply novel signal processing to separate the blood vessels with different decorrelation times, by varying of effective temporal diversity of processed signals.

  19. 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 savings of up to 3 kg/pig. Although several heavyweight pigs were removed before trial commencement and the variable number of remaining pigs per pen may have influenced the response to feed withdrawal, the present data indicates that finishing pigs can experience between 24 and 36 h of feed withdrawal without negatively affecting carcass composition. However, the increased incidence of leaking ingesta beyond 12 h of feed withdrawal is concerning. PMID:24987068

  20. The Effect of Spacing and Time of Thinning on the Yield, Growth, and Fruiting Characteristics of the Cotton Plant in 1925.

    E-print Network

    Stansel, R. H. (Roy Harrison)

    1927-01-01

    due to late thinning and close spacing. Three out of nine in Louisiana obtained results in favor of early, or normal thin- ning. In all cases the gain mas negligible. This mork is open to the serious criticism that two variables, rate and time... the plants are stunted by undue crowding." Hall and Armstrong (22) report mork at Florence, South Carolina, comparing early and delayed thinning in 1923 and 1924. The plants were spaced 12 inches apart in the row and the late thinning mas done...

  1. Influence of the Observation Geometry on the Estimation of Gravity Wave Amplitudes using TIMED-SABER, NDMC and Radiosonde Measurements and Conclusions concerning Wave Characteristics

    NASA Astrophysics Data System (ADS)

    Wüst, S.; Wendt, V.; Schmidt, C.; Yee, J. H.; Mlynczak, M. G.; Russell, J. M., III; Bittner, M.

    2014-12-01

    Gravity wave parameters can be derived by means of different instrumental techniques. Due to instrumental-specific limitations, information about the waves' amplitudes is averaged individually in time and space; this leads to an underestimation of amplitudes depending on wavelengths and periods, respectively. Global TIMED-SABER temperature data from 2002 to 2013 are analysed with respect to gravity wave activity in the strato- and mesosphere as well as in the mesopause region. Depending on geographical position significant differences for the ascending and descending part of the orbit can be observed when gravity wave activity is averaged over one yaw cycle. Due to the specific orientation of the fields-of-view at polar latitudes the result might be explained by a preferred horizontal wave orientation. Analyses of radiosondes released at ALOMAR, Northern Norway in late winter / early spring 2012 confirm a preferred orientation of wave fronts which is parallel to the mountain ridge. The analysis is repeated for Oberpfaffenhofen, Southern Germany in the vicinity of the Alps. The underestimation of amplitudes by SABER is quantified for both locations on a statistical base. Finally, gravity wave activity in the mesopause is derived from NDMC (Network for the Detection of Mesospheric Change) data including amongst others the stations at ALOMAR and Oberpfaffenhofen. The effects of the size and orientation of the different fields-of-view are discussed. Conclusions how to make use of the different instrumental averaging effects in terms of gravity wave characterization - especially for polar latitudes - are drawn.

  2. Influence of the Observation Geometry on the Estimation of Gravity Wave Amplitudes using TIMED-SABER, NDMC and Radiosonde Measurements and Conclusions concerning Wave Characteristics

    NASA Astrophysics Data System (ADS)

    Wüst, Sabine; Wendt, Verena; Schmidt, Carsten; Yee, Sam; Mlynczak, Martin; Russell, James M., III; Bittner, Michael

    2015-04-01

    Gravity wave parameters can be derived by means of different instrumental techniques. Due to instrumentalspecific limitations, information about the waves' amplitudes is averaged individually in time and space; this leads to an underestimation of amplitudes depending on wavelengths and periods, respectively. Global TIMED-SABER temperature data from 2002 to 2013 are analysed with respect to gravity wave activity in the strato- and mesosphere as well as in the mesopause region. Depending on geographical position significant differences for the ascending and descending part of the orbit can be observed when gravity wave activity is averaged over one Yaw-cycle. Due to the specific orientation of the fields-of-view at polar latitudes the result might be explained by a preferred horizontal wave orientation. Analyses of radiosondes released at ALOMAR, Northern Norway in late winter / early spring 2012 confirm a preferred orientation of wave fronts which is parallel to the mountain ridge. The analysis is repeated for Oberpfaffenhofen, Southern Germany in the vicinity of the Alps. The underestimation of amplitudes by SABER is quantified for both locations on a statistical base. Finally, gravity wave activity in the mesopause is derived from NDMC data including amongst others the stations at ALOMAR and Oberpfaffenhofen. The effects of the size and orientation of the different fields-of-view are discussed. Conclusions how to make use of the different instrumental averaging effects in terms of gravity wave characterization are drawn.

  3. Resolving the EGF-EGFR interaction characteristics through a multiple-temperature, multiple-inhibitor, real-time interaction analysis approach

    PubMed Central

    BJÖRKELUND, HANNA; GEDDA, LARS; MALMQVIST, MAGNUS; ANDERSSON, KARL

    2013-01-01

    Overexpression and aberrant activity of the epidermal growth factor (EGF) have been observed in various cancer types, rendering it an important target in oncology research. The interaction between EGF and its receptor (EGFR), as well as subsequent internalization, is complex and may be affected by various factors including tyrosine kinase inhibitors (TKIs). By combining real-time binding curves produced in LigandTracer® with internalization assays conducted at different temperatures and with different TKIs, the processes of ligand binding, internalization and excretion was visualized. SKOV3 cells had a slower excretion rate compared to A431 and U343 cells, and the tested TKIs (gefitinib, lapatinib, AG1478 and erlotinib) reduced the degree of internalization. The kinetic analysis of the binding curves further demonstrated TKI-dependent balances of EGFR monomer and dimer populations, where lapatinib promoted the monomeric form, while the other TKIs induced dimers. The dimer levels were found to be associated with the apparent affinity of the EGF-EGFR interaction, with EGF binding stronger to EGFR dimers compared to monomers. This study analyzed how real-time molecular interaction analysis may be utilized in combination with perturbations in order to understand the kinetics of a ligand-receptor interaction, as well as some of its associated intracellular processes. Our multiple-temperature and -inhibitor assay setup renders it possible to follow the EGFR monomer, dimer and internalized populations in a detailed manner, allowing for a new perspective of the EGFR biology. PMID:24649173

  4. A new technique for measuring the temporal characteristics of the carbon fibre microelectrodes in in vivo voltammetry at millisecond time intervals.

    PubMed

    Yavich, L

    1998-10-01

    A common approach to test the time-response of carbon fibre microelectrodes entails the use of a flow injection system which allows delivery of a bolus of test compound in the flow stream to a detector electrode. The introduced bolus is distorted from its original form by convective and dispersive forces during the period of transport from the injector to the detector electrode in the connection tubing and couplings. Thus, the flow injection system allows one to change the medium in the vicinity of the electrode in about 100-200 ms. We describe here a simple falling drop system, which is an easy to use for calibration of the carbon fibre microelectrodes with respect to their sensitivity and time-response. This system does not have a loop injector and minimizes problems associated with convective and dispersive bolus distortion. It allows one to change the medium in the vicinity of the electrode in less than 10 ms. With this system, the sensitivity and the temporal resolution of the electrodes may be easily and rapidly estimated in a single experiment. The temporal resolution of the untreated, uncoated carbon fibre cylinder electrode of 300 microns tip length in response to dopamine was estimated as 1.49 +/- 0.1 microM/ms (M +/- SEM, n = 36, rise) and 0.051 +/- 0.003 microM/ms (n = 36, wash-out) on the half of amplitude of electrochemical response which was monitored by constant potential amperometry. PMID:9821630

  5. 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).

  6. The characteristic Rossby frequency

    NASA Technical Reports Server (NTRS)

    Straus, David M.; Lindzen, Richard S.; Dasilva, Arlindo Moraes

    1987-01-01

    The characteristic Rossby frequency is defined for a fixed zonal wavenumber perturbation as the variational integral of the Rayleigh-Ritz method. It is a measure of the time scale of the disturbance. For a disturbance which locally has the shape of an eigenfunction but is not global in extent, the characteristic Rossby frequency is very close to the true eigenvalue, and additionally remains unchanged under linear inviscid dynamics. Results are presented for the shallow water equations, both with and without a mean zonal wind. The characteristic Rossby frequency of a wavenumber 1 perturbation having the shape of the second symmetric Rossby mode but confined to the Northern Hemisphere is close to the corresponding Rossby frequency. This finding is helpful in understanding the behavior of the observed wavenumber 1 pattern of January 1979, which propagated westward with nearly the pure Rossby frequency but was discernible only in the Northern Hemisphere (as discussed by Daley and Williamson).

  7. The Characteristics and Climate Forcing Implication of the Multi-time Scale Fluctuations in the Air Temperature in Xiamen, China From 1954 to 2007

    NASA Astrophysics Data System (ADS)

    Li, X.; Huang, S.; Ye, H.; Zhang, R.; Li, S.

    2009-05-01

    Xiamen (also known as Amoy) is a coastal city with a population of over 1.5 millions located in the southeast Fujian Province across the Taiwan Strait from Taiwan. The monthly and annual surface air temperature (SAT) time series from 1954 on from its meteorological observatory (24.48 °N, 118.07 °E, 139.0m) are available at the National Meteorological Information Centre of China Meteorological Administration and the Global Historical Climatology Network online database. Over the 54-year period from 1954 to 2007, Xiamen experienced diverse seasonal trends in SAT: warming at a rate of 0.14 K/10a in winter and 0.05 K/10a in spring, as opposed to cooling at -0.04 and -0.03 K/10a in summer and fall, respectively. Overall, the trend in the annual SAT series over the 54-year period is an insignificant warming rate of 0.03 K/a, which is substantially smaller than the nation-wide and global averages. Nevertheless, the fluctuations in the SAT may bear important clues about climate forcing in this region. Our Morlet wavelet analysis reveals three principle time scales -- 42-year, 30-year, and 13-year -- in the Xiamen annual series. Interestingly, the periodic component of around 13-year, ranging from 9 to 15 years, exhibits not only in the annual series, but also in the four seasonal series. Moreover, the components of roughly same scale have been detected from several nearby meteorological stations including Fuzhou and Nanping in Fujian Province, and Tainan, Kaohsiung and Hengchun in Taiwan. The possible attribution of this 9- to 15-year temperature fluctuation to the solar activity cycling remains under investigation.

  8. A C60 primary ion beam system for time of flight secondary ion mass spectrometry: its development and secondary ion yield characteristics.

    PubMed

    Weibel, Daniel; Wong, Steve; Lockyer, Nicholas; Blenkinsopp, Paul; Hill, Rowland; Vickerman, John C

    2003-04-01

    A buckminsterfullerene (C60)-based primary ion beam system has been developed for routine application in TOF-SIMS analysis of organic materials. The ion beam system is described, and its performance is characterized. Nanoamp beam currents of C60+ are obtainable in continuous current mode. C60(2+) can be obtained in pulsed mode. At 10 keV, the beam can be focused to less than 3 microm with 0.1 nA currents. TOF-SIMS studies of a series of molecular solids and a number of polymer systems in monolayer and thick film forms are reported. Very significant enhancement of secondary ion yields, particularly at higher mass, were observed using 10-keV C60+ for all samples other than PTFE, as compared to those observed from 10 keV Ga+ primary ions. Three materials (PS2000, Irganox 1010, PET) were studied in detail to investigate primary ion-induced disappearance (damage) cross sections to determine the increase in secondary ion formation efficiency. The C60 disappearance cross sections observed from monolayer film PS2000 and self-supporting PET film are close to those observed from Ga+. The resulting C60 efficiencies are 30-100 times those observed from gallium. The cross sections observed from C60 bombardment of multilayer molecular solids are approximately 100 times less, such that essentially zero damage sputtering is possible. The resulting efficiencies are > 10(3) greater than from gallium. It is also shown that C60 primary ions do not generate any more low-mass fragments than any other ion beam system does. C60 is shown to be a very favorable ion beam system for TOF-SIMS, delivering high yield, close to 10% total yield, favoring high-mass ions, and on thick samples, offering the possibility of analysis well beyond the static limit. PMID:12705613

  9. 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

  10. 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)

  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

    2014-12-01

    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. PMID:25474335

  12. Time characteristics of laser initiation of PETN

    Microsoft Academic Search

    A. A. Volkova; A. D. Zinchenko; I. V. Sanin; V. I. Tarzhanov; B. B. Tokarev

    1977-01-01

    Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a We have investigated the dependence of the initiation-energy threshold for PETN on the length of the initiating laser pulse\\u000a (?=1.06 ?) over the interval 7.5–100 nsec for both direct photo-initiation of the charge and indirect initiation by means\\u000a of an intervening metal film (300 ). In these two cases the initiation-energy threshold increases with pulse length by factors

  13. Structural test with functional characteristics

    Microsoft Academic Search

    B. Nadeau-Dosti; Muhiuzzaman Mahmud; Jean-François Côté; F. Maamaril

    2005-01-01

    A novel structural test clocking architecture is proposed to reproduce characteristics of the functional mode of operation that are essential to a high-quality test. Bursts of functional mode clocks are controlled to provide accurate timing tests taking into account functional timing constraints such as multi-cycle paths and false paths. Any mix of asynchronous and synchronous clocks is supported. Long term

  14. 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.

  15. IT'S ABOUT TIME Characteristic times in biogeochemistry and climate

    E-print Network

    Schwartz, Stephen E.

    concentration over the last thousand years Polar ice cores #12;THE GLOBAL CARBON CYCLE Preindustrial fuel emissions. 2 100 ppm #12;THE GLOBAL CARBON CYCLE Preindustrial and anthropogenic perturbation. Total in reservoir 762 Total flux out of reservoir 215 3.5 years #12;THE GLOBAL CARBON CYCLE

  16. Clinical characteristics, and time course of pancreatic beta-cell function and glutamic acid decarboxylase antibodies in Thai patients with adult-onset Type 1 diabetes: distinction between patients of rapid- and slow-onset.

    PubMed

    Rattarasarn, C; Diosdado, M A

    1999-05-01

    In order to study the clinical characteristics, time course of beta cell function and glutamic acid decarboxylase antibodies (GAD65Ab) in Thai patients with adult-onset Type 1 diabetes and to examine the distinctive features between patients with rapid-and slow-onset, 61 Thai patients with Type 1 diabetes who had age of disease onset at or after 20 years were studied. All patients were treated with insulin at the time of study and had fasting C-peptide levels +/-0.33 nmol/l. Twenty-six (42.6%) were in rapid-onset and 35 (57.4%) were in slow-onset groups. Fourty-four of 61 (70.5%) were male. About three-fourths had body mass index (BMI) < 19 kg/m2 at the time of insulin therapy. Only 7 of 61 (11.5%) patients had ketoacidosis at first presentation. Five patients had associated autoimmune thyroid disease and 10 (16.7%) patients had family history of diabetes in first-degree relatives. GAD65Ab was positive in 31 patients (50.8%); 10 (38.5%) were in rapid-onset and 21 (60.0%) were in slow-onset groups. GAD65Ab particularly of high levels were persistently elevated during 3-4 years follow-up period. The persistence of GAD65Ab were not associated with changes in fasting C-peptide levels. At the time of insulin dependency, there were no distinctive clinical features between rapid- and slow-onset patients except higher fasting C-peptide (0.08+/-0.08 vs. 0.14+/-0.10 nmol/l; p = 0.023) and GAD65Ab levels (19.6+/-17.4 vs. 46.1+/-49.7 U/ml; p = 0.036) in slow-onset patients. Fasting C-peptide levels of patients in the latter group were also demonstrated to be higher after 3-4 years of follow-up. In conclusion, most Thai patients with adult-onset Type 1 diabetes in this study were male and had significant degree of weight loss and lean BMI prior to insulin therapy. The presence of GAD65Ab did not predict clinical features or rate of beta cell loss. Patients in rapid-onset group had lower fasting C-peptide and GAD65Ab levels than those of slow-onset group which confirms the slower process of beta cell failure in the latter. PMID:10422726

  17. Characteristics of plasmaspehrtic hiss

    NASA Astrophysics Data System (ADS)

    Laakso, Harri; Santolik, Ondrej; Kolmasova, Ivana; Horne, Richard; Escoubet, Philippe; Masson, Arnaud; Taylor, Matt

    2015-04-01

    The plasmaspheric hiss is regularly observed in the inner magnetosphere, particularly in the plasmasphere and in the related high-density regions such as in the plumes. Even the phenomenon is well known for long time, the generation mechanism of hiss has remained open. Neither its characteristics are well known. The hiss is important because it is believed to cause loss of radiation belt particles. We have investigated the hiss emission during the Cluster perigee passes and found enhanced emission to occur both in the plasmaspheric plumes and in the plasmasphere. However, their wave characteristics differ significantly. Due to the polar orbits of the four Cluster spacecraft, each spacecraft provides two snapshots of hiss, separated by a few hours, on the two opposing hemispheres, so differences in wave characteristics between two hemispheres can be discerned. Furthermore the four spacecraft follow each other within an hour, so the temporal variation of hiss over the same hemisphere can be observed as well. Occasionally the spacecraft are simultaneously located in the same flux tube in the both hemispheres. Most of the time hiss does not vary much within an hour (except for some spatial variations) even if the geomagnetic conditions vary. However, hemispheric differences are significant: all observations in the plumes show that the wave vector is parallel with the local magnetic field vector and the waves propagate away from the equatorial region of the plumes. In the plasmasphere at lower L shells the hiss is observed as well but here over both hemispheres the waves propagate towards the equator and the wave vector has a larger angle with the magnetic field. We conclude that the equatorial plume region is a source region of plasmaspheric hiss and the waves propagate towards the polar regions where they are refracted and reflected towards lower L shells and into the plasmasphere.

  18. 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. PMID:25661991

  19. Effect of bulk viscosity on Kelvin-Helmholtz instability

    Microsoft Academic Search

    Yu. N. Grigor’ev; I. V. Ershov

    2008-01-01

    An energy functional leading to a resolvable variational problem for determining the critical Reynolds number of laminar-turbulent\\u000a transition Re\\u000a \\u000a cr\\u000a is constructed within the framework of the nonlinear energy stability theory of compressible flows. Asymptotic estimates\\u000a containing the characteristic dependence $$\\\\operatorname{Re} _{cr} \\\\sim \\\\sqrt {\\\\alpha + 4\\/3} (\\\\alpha = \\\\eta _b \\/\\\\eta )$$ in the main order are obtained for

  20. 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.

  1. Seasonal vegetation characteristics of the United States

    Microsoft Academic Search

    Bradley C. Reed; Limin Yang

    1997-01-01

    The U.S. Geological Survey's EROS Data Center has created a prototype 1?km resolution data base of vegetation seasonal characteristics. The characteristics are derived from time?series NDVI data collected by the AVHRR satellite sensor. Information covering the 5 years 1989–1993 is included in the data base. Although quantitative validation of the seasonal characteristics cannot be made until several evaluation efforts are

  2. 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.

  3. Small signal frequency characteristic of electroluminescent diodes

    Microsoft Academic Search

    L. Kucera; V. Snejdar; H. Barankova

    1979-01-01

    Under simplifying assumptions the small signal frequency characteristic of the planar geometry electroluminescent diode is derived. It has been found that it is generally determined by the diode impedance, by transit-time phenomena of injected carriers and by absorption losses, which depend on the a.c. photon generation rate distribution in the diode volume. The dependence of the frequency characteristic on the

  4. Geologic Time

    NSDL National Science Digital Library

    This Classroom Connectors lesson plan discusses the characteristics of geologic time, including the law of superposition, fossil preservation, casts and molds, and various events through the history of the Earth. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

  5. Takeoff characteristics of turbofan engines

    Microsoft Academic Search

    Young B. Suh

    1990-01-01

    The present derivation of reliable formulas for the takeoff characteristics of turbofan-powered aircraft, encompassing ground-roll distance and time, fuel consumption, etc, incorporates ground effect-induced drag reduction. This drag reduction factor is varied according to type of aircraft; the turbofans in question may be of high-bypass transport-aircraft type or of low bypass and afterburner-employing configuration, as is typically the case in

  6. MR characteristics of iophendylate (Pantopaque).

    PubMed

    Hackney, D B; Grossman, R I; Zimmerman, R A; Joseph, P M; Goldberg, H I; Bilaniuk, L T

    1986-01-01

    Although iophendylate (Pantopaque) has been largely replaced by water soluble agents for myelography, retained intracranial or intraspinal Pantopaque remains a common occurrence. Pantopaque has signal characteristics similar to fat with both short T1 and T2 relaxation times. In vitro measurements revealed T1 = 170 ms and T2 = 27 ms. Spine radiography is recommended in patients with a history of previous myelography and magnetic resonance abnormalities similar to fat. PMID:3486195

  7. Characteristic Evolution and Matching

    E-print Network

    Jeffrey Winicour

    2005-12-08

    I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black spacetime. A prime application of characteristic evolution is to compute waveforms via Cauchy-characteristic matching, which is also reviewed.

  8. Wide-Bandgap III–V nitride based avalanche transit-time diode in Terahertz regime: Studies on the effects of punch through on high frequency characteristics and series resistance of the device

    Microsoft Academic Search

    Moumita Mukherjee; Sitesh Kumar Roy

    2010-01-01

    Extensive simulation investigations on III–V nitride (Gallium Nitride, GaN) based Single Drift (p++ n n++) avalanche transit-time diode clearly establishes the potential of GaN material system in Terahertz region. Further, the effects of punch through on the Terahertz behavior of the GaN IMPATT (IMPact Avalanche Transit-Time diode) are studied for the first time, through a generalized simulation technique. The computed

  9. Cognitive characteristics and homosexuality

    Microsoft Academic Search

    Martin Willmott; Harry Brierley

    1984-01-01

    There have been many studies of psychological characteristics of homosexuals, but cognitive characteristics have been relatively neglected. This study investigated the verbal intelligence of 20 homosexual males, 20 heterosexual males, and 20 females, taking into account variables likely to affect verbal ability such as social class and handedness. There were no differences in overall IQ, but group differences in verbal

  10. Vibration Characteristics of Thermoplastic Composite

    NASA Astrophysics Data System (ADS)

    Haldar, Amit Kumar; Singh, Satnam; Prince

    2011-12-01

    Unreinforced, Long fiber and Short fiber polypropylene composites are being used in many antivibration applications, due to their time and temperature dependent specific mechanical properties. Their good damping behavior accounts for many engineering applications. For utilization of these materials in specific engineering applications, there is a need to understand the damping behavior of composites under dynamic load. For this work, unreinforced and 20% long and short reinforced glass fiber polypropylene composite materials were tested for forced transverse vibration damping characteristics under static as well as fatigue loading conditions. The damping characteristics are quantified by forced frequency response of the test material. Presence of reinforced fibers increases the damping capacity. Among reinforcements, short fiber reinforced polypropylene shows increased damping capacity then long glass fiber reinforced.

  11. Starting Over: Characteristics of Adult Literacy Learners.

    ERIC Educational Resources Information Center

    Smith-Burke, M. Trika; And Others

    A study examined the characteristics of those individuals who participate in New York City's adult literacy programs. Interviews were conducted with 32 native-born U.S. citizens (native speakers of English) who had enrolled in a literacy program for the first time and had been reading somewhere up to the 4.9 grade level at the time they entered…

  12. Improved modelling of system dynamic load characteristics

    SciTech Connect

    Barakat, E.H.; Qayyum, M.A.; Hamed, M.N.; Al Rashed, S.A. (Saudi Consolidated Electric Co., P.O. Box 57, Al Riyadh 11411 (SA))

    1990-08-01

    In this paper, system load characteristics have been modified in order to allow for the load contribution associated with three cyclic events. The adjusted time-series load data are further analyzed using classical forecasting methods. Statistical errors associated with the demand forecasts obtained by the classical methods using original and adjusted time-series are compared.

  13. 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 ?. 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.

  14. Characteristic Evolution and Matching

    E-print Network

    Jeffrey Winicour

    2012-01-12

    I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.

  15. 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.

  16. Time After Time

    NSDL National Science Digital Library

    National Security Agency Central Security Service

    2009-04-22

    Students use a variety of strategies and techniques to develop an understanding of telling time. They use estimation to tell time, using seconds, hours, and minutes in order to choose reasonable time estimates for given activities. Students use pictures, words, and symbols in order to read, write, and represent time to the nearest minute. Students determine elapsed time when given a start time, counting up using minutes and hours.

  17. Lead attenuation characteristics models.

    PubMed

    Lee, K L; Schick, D

    2009-12-01

    Lead attenuation characteristic curves are often consulted in premises radiation shielding assessments employing the non-destructive testing (NDT) method. This study developed lead attenuation characteristics mathematical models for the radionuclide Co-57. These models take into account the statistical variation of the attenuation characteristics. The results are a set of equations that a NDT assessor can use to predict the range of transmission factors for the NDT measurement or, using the inverse functions, to gauge the lead equivalence (with the associated uncertainty) of a radiation barrier. This study showed that the combined effect of types of statistical variations can form an uncertainty region on the transmission characteristics such that the relative uncertainty decreases for values of lead mass per unit area up to approximately 20 kg/m2 and 15 kg/m2 for the Ludlum 18 and Ludlum 2241-2 survey meters respectively but thereafter increases. PMID:20169840

  18. AEROSOL CHARACTERISTICS AND VISIBILITY

    EPA Science Inventory

    This report summarizes progress in measuring the optical properties of aerosols and in relating aerosol characteristics to visibility reduction made in the author's laboratory during the period 1965-1971. An instrument, the integrating nephelometer, which measures the scattering ...

  19. 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.

  20. Housing characteristics 1993

    SciTech Connect

    NONE

    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.

  1. Residential Housing Characteristics Survey 1997

    NSDL National Science Digital Library

    1998-01-01

    Specific information such as how many homes have PCs, modems and FAX machines or how home appliance usage has changed over time (1978-1997) can now be obtained in this recently-released Residential Housing Characteristics Survey by the US Energy Information Administration. Nearly two decades of Regional Energy Consumption Surveys (RECS) on US households and their energy is contained on site in addition to supplementary maps, a glossary of terms, and documentation of EIA survey methods and data quality. To further facilitate research, the EIA provides a Data Table Home Page where users may choose variables and access data tables directly on site.

  2. Mixtures and Characteristic Functions*

    PubMed Central

    Klonecki, Witold

    1970-01-01

    Let g(u|c,y) = exp {y?ck(uk - 1)} with y > 0, ?k=0?ck = 1,|u| < 1, and c standing for {ck}, be a probability generating function of a nonnegative integer-valued random variable. Let S be a distribution function on (0, ?) non-degenerate at zero. The functions g and S determine another probability generating function, G(u|Sc) = ?0? gdS(y). One of the results obtained asserts that, if the sequence c is finite and the characteristic function of S is entire, then G determines uniquely both S and c. The assertion does not hold if these conditions are not satisfied. Another group of results refers to properties of characteristic functions. Let P(z) be a polynomial of degree m and f(z|y) = exp- {yP(z)}. The theorem of Marcinkiewicz asserts that with m > 2 the function f cannot be a characteristic function. It is shown that, if the characteristic function of S is entire, then F(z) = ?0? f(z|y)dS(y) can be characteristic function only if m ? 2. Again the assertion need not be true if the characteristic function of S is not entire. PMID:16591826

  3. Observation of a metal-to-insulator transition with both Mott-Hubbard and Slater characteristics in Sr2IrO4 from time-resolved photocarrier dynamics

    E-print Network

    Hsieh, David

    We perform a time-resolved optical study of Sr[subscript 2]IrO[subscript 4] to understand the influence of magnetic ordering on the low energy electronic structure of a strongly spin-orbit coupled J[subscript eff] = 1/2 ...

  4. 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 blaKPC-2, rmtB, blaCTX-M-65, blaSHV-11, oqxA, oqxB, and aac(6')-Ib-cr and even harbored additional other resistance genes, such as armA, blaCTX-M-1, blaTEM-1. blaKPC-2, rmtB, and blaCTX-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 - polyacrylamide 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. PMID:25865067

  5. 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.

  6. 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. PMID:25539774

  7. On recent developments in marginal separation theory.

    PubMed

    Braun, S; Scheichl, S

    2014-07-28

    Thin aerofoils are prone to localized flow separation at their leading edge if subjected to moderate angles of attack ?. Although 'laminar separation bubbles' at first do not significantly alter the aerofoil performance, they tend to 'burst' if ? is increased further or if perturbations acting upon the flow reach a certain intensity. This then either leads to global flow separation (stall) or triggers the laminar-turbulent transition process within the boundary layer flow. This paper addresses the asymptotic analysis of the early stages of the latter phenomenon in the limit as the characteristic Reynolds number [Formula: see text], commonly referred to as marginal separation theory. A new approach based on the adjoint operator method is presented that enables the fundamental similarity laws of marginal separation theory to be derived and the analysis to be extended 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 on its resolution being based on asymptotic arguments. The passage to the subsequent triple-deck stage is described in detail, which is a prerequisite for carrying out a future numerical treatment of this stage in a proper way. Moreover, a composite asymptotic model is developed in order for the inherent ill-posedness of the Cauchy problems associated with the current flow description to be resolved. PMID:24936013

  8. Aircraft equilibrium spin characteristics

    NASA Technical Reports Server (NTRS)

    Adams, W. M., Jr.

    1980-01-01

    Program provides analytic solutions to nonlinear equations of motion describing spin conditions. Stability characteristics also are determined. Program can be used to study effects of aerodynamic and inertial parameters on spin and could be modified to compute equilibrium conditions for steady maneuvers. Program is written in FORTRAN IV for batch execution on CYBER 173.

  9. Interrelationships of Watershed Characteristics

    Microsoft Academic Search

    Don M. Gray

    1961-01-01

    The application of the principles of dimensional analysis to obtain the relationships between characteristics of the unit hydrograph and topographic and morphometric properties of a watershed is not possible unless careful consideration is given to the selection of variables. Evidence is presented which shows that, in small watersheds, drainage-area size A, length of the main stream L, and length to

  10. Malting Barley Characteristics

    E-print Network

    Malting Barley Characteristics for Craft Brewers Executive Summary The brewing industry is evolving rapidly, and the barley malt supply chain should likewise evolve rapidly to meet the very different needs as a potential impediment to growing their brands. To produce all-malt beer brands, craft brewers seek barley

  11. 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.

  12. 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.

  13. Characteristic Curves of PEMFC

    NSDL National Science Digital Library

    This in-class exercise will allow students hands-on experience working with a proton exchange membrane fuel cell, or PEMFC. The class will examine the characteristic curve of one of these fuel cells and measure the voltage and current output of the cell. Step by step instructions are provided for the experiment. This document may be downloaded in PDF file format.

  14. Concrete Pavement Surface Characteristics

    E-print Network

    Improving Concrete Pavement Surface Characteristics Pooled Fund TPF-5(139) National Concrete, Broom, Belt, Carpet) Shot Peened Exposed Aggregate Porous (Pervious) Concrete Milled HMA and Surface do with this knowledge? #12;Better Design and Construction Practices for Texturing Concrete Pavement

  15. Characteristics of Instructional Technologists.

    ERIC Educational Resources Information Center

    Gagne, Robert M.

    A thoroughly planned program for instructional technologists--one including selection, education, and on-the-job training--must take into consideration the competencies and characteristics desirable in such technologists. Such requirements fall into three categories: attitudes or values, specialized knowledge, and intellectual skills or…

  16. Employment Characteristics of Families

    NSDL National Science Digital Library

    The Bureau of Labor Statistics site offers data on the employment characteristics of American families. The statistics include data on employment and unemployment in families by race, relationship, sex, marital status, presence of children in the family, and presence of children under three, among others. The data can be accessed from a table of contents or reviewed in an extensive news release.

  17. Yet another time about time

    E-print Network

    Simeonov, Plamen L

    2015-01-01

    This paper presents yet another personal reflection on one the most important concepts in both science and the humanities: time. This elusive notion has been not only bothering philosophers since Plato and Aristotle and goes throughout human history embracing all analytical and creative (anthropocentric) disciplines from mathematics through physical and life sciences to philosophy, psychology, music and art, with a vast body of knowledge across different theories and categories concerning its nature (rational, irrational, arational), appearances/qualia, degrees, dimensions and scales of conceptualization (internal, external, rational, irrational, fractal, discrete, continuous, mechanical, quantum, local, global, etc.), duration ranges, resolutions, modes (present, now, past, future), variety of tenses (e.g. present perfect, present progressive, etc.) and some intuitive, but also fancy phenomenological characteristics such as arrow, stream, texture, width, depth, and perhaps the most distinct one of them, the ...

  18. The Essential Characteristics of Academic Advisors

    ERIC Educational Resources Information Center

    Ward, Mary L.

    2011-01-01

    What started as an activity valued for its oversight, the work of academic advisors have become a means leading to other ends, such as retention, student engagement, student satisfaction, persistence, and time to degree. The purpose of this research was to identify the essential characteristics of academic advisors; this was achieved by asking a…

  19. Compression ignition characteristics of coal slurry fuels

    Microsoft Academic Search

    Brehob

    1985-01-01

    Slow and medium speed compression ignition engines are devices with the potential for conversion to coal fueling. Recent work focuses on coal slurried in a liquid carrier. Engine studies on coal slurry to date have investigated the slurries' wear, thermal efficiency, and injection performance. Previously lacking information on the compression ignition characteristics of coal slurries, specifically, the ignition delay times

  20. Photodetector and Receiver Characteristics

    NSDL National Science Digital Library

    In this video from the ICT Center, learn about fiber optic receivers. Investigate the components of an optical receiver; how a photodetector converts an optical signal to an electrical one; and the characteristics of PIN, avalanche, and metal-semiconductor-metal photodiodes.The video runs 2:07 and is accompanied by a background essay, standards alignment, and discussion questions. Users who sign up for a free account can save the resource and download the video as well.

  1. Characteristics of healthcare wastes

    SciTech Connect

    Diaz, L.F. [CalRecovery, Inc., Concord, California (United States)], E-mail: ludiaz@calrecovery.com; Eggerth, L.L. [CalRecovery, Inc., Concord, California (United States); Enkhtsetseg, Sh. [Ministry of Health, Ulaanbaatar (Mongolia); Savage, G.M. [CalRecovery, Inc., Concord, California (United States)

    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 facilitate comparative analyses among different facilities, studies and countries.

  2. Wave Types and Characteristics

    NSDL National Science Digital Library

    Cooperative Program for Operational Meteorology (the COMET Program)

    This site created by the COMET program (Cooperative Program for Operational Meteorology, Education and Training) explains the attributes of waves found in large bodies of water. Using audio text, video clips and photographs, the site discusses the origins, types, and characteristics of waves, as well as mathematical expressions and statistical traits such as wave spectrum and height classifications. The site is also available in text form, and features a glossary, a bibliography and a quiz.

  3. Fibre Optic Sensors for Selected Wastewater Characteristics

    PubMed Central

    Chong, Su Sin; Abdul Aziz, A. R.; Harun, Sulaiman W.

    2013-01-01

    Demand for online and real-time measurements techniques to meet environmental regulation and treatment compliance are increasing. However the conventional techniques, which involve scheduled sampling and chemical analysis can be expensive and time consuming. Therefore cheaper and faster alternatives to monitor wastewater characteristics are required as alternatives to conventional methods. This paper reviews existing conventional techniques and optical and fibre optic sensors to determine selected wastewater characteristics which are colour, Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). The review confirms that with appropriate configuration, calibration and fibre features the parameters can be determined with accuracy comparable to conventional method. With more research in this area, the potential for using FOS for online and real-time measurement of more wastewater parameters for various types of industrial effluent are promising. PMID:23881131

  4. LED and Transmitter Characteristics

    NSDL National Science Digital Library

    In this video from the ICT Center, learn about fiber optic transmitters. Explore the components of a fiber optic transmitter, including a source, a modulator, an electrical driving circuit, and fiber coupling mechanics. Animations illustrate how the process of spontaneous emission converts electrical information to an optical signal in a light-emitting diode, or LED. In addition, learn about characteristics that make a source suitable for fiber optic communications.The video runs 3:12 and is accompanied by a background essay, standards alignment, and discussion questions. Users who sign up for a free account can save the resource and download the video as well.

  5. Magnesium battery disposal characteristics

    NASA Astrophysics Data System (ADS)

    Soffer, Louis; Atwater, Terrill

    1994-12-01

    This study assesses the disposal characteristics of U.S. Army procured military magnesium batteries under current Resource Conservation and Recovery Act (RCRA) hazardous waste identification regulations administered by the U.S. Environmental Protection Agency. Magnesium batteries were tested at 100, 50, 10 and 0 percent remaining state of charge. Present findings indicate that magnesium batteries with less than 50 percent remaining charge do not exceed the federal regulatory limit of 5.0 mg/L for chromium. All other RCRA contaminates were below regulatory limits at all levels of remaining charge. Assay methods, findings, disposal requirements and design implications are discussed.

  6. The characteristics of success

    Microsoft Academic Search

    Scattolini

    1986-01-01

    The advent of personal computers can bring powerful analytical techniques to individuals for relatively little expense. As with any computer work, database building can be tedious and time consuming. Putting aside the time spent, the way such a database is used is most important. For interpretation work, the effort invested can be a valuable addition to understanding the earth, its

  7. Characteristics of success

    Microsoft Academic Search

    Scattolini

    1988-01-01

    The advent of personal computers can bring powerful analytical techniques to individuals for relatively little expense. As with any computer work, database building can be tedious and time consuming. Putting aside the time spent, the way such a database is used is most important. For interpretation work, the effort invested can be a valuable addition to understanding the earth, its

  8. Modeling Pulse Characteristics in Xenon with NEST

    E-print Network

    Mock, Jeremy; Kazkaz, Kareem; Szydagis, Matthew; Tripathi, Mani; Uvarov, Sergey; Woods, Michael; Walsh, Nicholas

    2013-01-01

    A comprehensive model for describing the characteristics of pulsed signals, generated by particle interactions in xenon detectors, is presented. An emphasis is laid on two-phase time projection chambers, but the models presented are also applicable to single phase detectors. In order to simulate the pulse shape due to primary scintillation light, effects such as the ratio of singlet and triplet dimer state populations, as well as their corresponding decay times, and the recombination time are incorporated into the model. In a two phase time projection chamber, when simulating the pulse caused by electroluminescence light, parameters such as ionization electron mean free path in gas, the drift velocity, singlet and triplet decay times, diffusion constants, and the electron trapping time, have been implemented. This modeling has been incorporated into a complete software package, which realistically simulates the expected pulse shapes for these types of detectors.

  9. Modeling pulse characteristics in Xenon with NEST

    NASA Astrophysics Data System (ADS)

    Mock, J.; Barry, N.; Kazkaz, K.; Stolp, D.; Szydagis, M.; Tripathi, M.; Uvarov, S.; Woods, M.; Walsh, N.

    2014-04-01

    A comprehensive model for describing the characteristics of pulsed signals, generated by particle interactions in xenon detectors, is presented. An emphasis is laid on two-phase time projection chambers, but the models presented are also applicable to single phase detectors. In order to simulate the pulse shape due to primary scintillation light, the effects of the ratio of singlet and triplet dimer state populations, as well as their corresponding decay times, and the recombination time are incorporated into the model. In a two phase time projection chamber, when simulating the pulse caused by electroluminescence light, the ionization electron mean free path in gas, the drift velocity, singlet and triplet decay times, diffusion constants, and the electron trapping time, have been implemented. This modeling has been incorporated into a complete software package, which realistically simulates the expected pulse shapes for these types of detectors.

  10. Firm characteristics, total quality management, and financial performance

    Microsoft Academic Search

    Kevin B. Hendricks; Vinod R. Singhal

    2000-01-01

    This paper uses a sample of quality award winners to empirically test hypotheses that relate changes in operating income associated with effective implementation of total quality management (TQM) to various firm characteristics. The characteristics examined are firm size, the degree of capital intensity, the degree of diversification, the timing of TQM implementation, and the maturity of the program. We find

  11. Firm characteristics, total quality management, and financial performance

    Microsoft Academic Search

    Kevin B Hendricks; Vinod R Singhal

    2001-01-01

    This paper uses a sample of quality award winners to empirically test hypotheses that relate changes in operating income associated with effective implementation of total quality management (TQM) to various firm characteristics. The characteristics examined are firm size, the degree of capital intensity, the degree of diversification, the timing of TQM implementation, and the maturity of the program. We find

  12. Characteristics and Perspectives of Faculty at Public 2-Year Colleges

    ERIC Educational Resources Information Center

    Hardy, David E.; Laanan, Frankie Santos

    2006-01-01

    This descriptive study makes use of the 1999 National Study of Postsecondary Faculty (NSOPF:99) public access database. It examines the demographic characteristics of full-time faculty in American public 2-year colleges at the close of the 20th century and how these characteristics differ across and within age groups. This study also examines…

  13. Direct simulation of pumping characteristics for a model diffusion pump

    Microsoft Academic Search

    YK Lee; JW Lee

    1996-01-01

    The pumping characteristics of a single\\/multi-stage diffusion pump were simulated using the Direct Simulation Monte Carlo (DSMC) method. The hard sphere model is used as a molecular model and the No Time Counter (NTC) scheme is employed as a collision sampling technique. Steady state flow characteristics such as velocity, temperature, density distributions of the pumped gas and oil vapor are

  14. Telling Time

    NSDL National Science Digital Library

    Miss Lerdahl

    2010-01-26

    Practice telling time with these fun games and activities! Match the time on the clocks with this game! Match the clocks game! Primary Games Match the Clocks Tell time with a dragon. Stop the clock! Make the right time! Time to the Hour Quiz Time Test Time to the Minute Quiz Practice telling what time it will be later. Elapsed Time Work on Elapsed Time Test your skills with the Matching Elapsed Time Game ...

  15. An Implicit Characteristic Based Method for Electromagnetics

    NASA Technical Reports Server (NTRS)

    Beggs, John H.; Briley, W. Roger

    2001-01-01

    An implicit characteristic-based approach for numerical solution of Maxwell's time-dependent curl equations in flux conservative form is introduced. This method combines a characteristic based finite difference spatial approximation with an implicit lower-upper approximate factorization (LU/AF) time integration scheme. This approach is advantageous for three-dimensional applications because the characteristic differencing enables a two-factor approximate factorization that retains its unconditional stability in three space dimensions, and it does not require solution of tridiagonal systems. Results are given both for a Fourier analysis of stability, damping and dispersion properties, and for one-dimensional model problems involving propagation and scattering for free space and dielectric materials using both uniform and nonuniform grids. The explicit Finite Difference Time Domain Method (FDTD) algorithm is used as a convenient reference algorithm for comparison. The one-dimensional results indicate that for low frequency problems on a highly resolved uniform or nonuniform grid, this LU/AF algorithm can produce accurate solutions at Courant numbers significantly greater than one, with a corresponding improvement in efficiency for simulating a given period of time. This approach appears promising for development of dispersion optimized LU/AF schemes for three dimensional applications.

  16. 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)

  17. Correlating Aluminum Burning Times

    Microsoft Academic Search

    M. W. Beckstead

    2005-01-01

    Characteristics of aluminum combustion are summarized in an overview of the subject, focusing on the burning time of individual particles. Combustion data from over ten different sources with almost 400 datum points have been cataloged and correlated. Available models have also been used to evaluate combustion trends with key environmental parameters. The fundamental concepts that control aluminum combustion are discussed,

  18. Young Children's Sibling Relationship Interactional Types: Associations with Family Characteristics, Parenting, and Child Characteristics

    ERIC Educational Resources Information Center

    Gamble, Wendy C.; Yu, Jeong Jin

    2014-01-01

    Research Findings: This study examines patterns of sibling relationship qualities or interactional types and their association with family characteristics, parenting, and the characteristics of 1 of those children. Participants were 65 children (34 boys; Time 1 mean age = 51 months), their mothers, fathers, and Head Start teachers. Approximately…

  19. Long Characteristic Method in Space and Time for Transport Problems

    E-print Network

    Pandya, Tara M.

    2010-07-14

    and using the relationship in Eq. (2.1) the actual distance traveled (#3;s) can be related to the distance along the u axis as shown in Eq. (2.4): 2/ sin 1u s sq mD = D = D + (2.4). In this work it is assumed that the distance between adjacent parallel... originating : at 1 , 0 rays originating 1 on left or right : , boundaries k k k initial k k k k k k x x t x x t t allv w m m w m m mw m m - - - #2; = + D + >#3; #4; #5; #6;#7; #4; = - D + <#8; #3; #2; +#4; #4; = + D#5; #6; #4; #4;#8;#7; (2.5) Figure 2...

  20. Time characteristics of olfaction in a single breath

    Microsoft Academic Search

    Daisuke Noguchi; Sayumi Sugimoto; Yuichi Bannai; Ken-ichi Okada

    2011-01-01

    The transmission of olfactory information together with audiovisual information is now attracting much attention. However, the information is difficult to synchronize because of problems of scent lingering in the air and olfactory adaptation. We aimed at minimizing the amount of odorant presented to users in order to mitigate these problems, and developed an olfactory display that is able to present

  1. animals --produce characteristic, heritable incubation times and patterns of brain

    E-print Network

    Hays, Graeme

    into hamsters, the animals died rapidly. So the infectious agent had silently replicated for several years to hamsters, it is hard to understand why -- in thisinstance--theyretainedtheirinfectivity. It would seem

  2. Wafer characteristics via reflectometry

    SciTech Connect

    Sopori, Bhushan L. (Denver, CO)

    2010-10-19

    Various exemplary methods (800, 900, 1000, 1100) are directed to determining wafer thickness and/or wafer surface characteristics. An exemplary method (900) includes measuring reflectance of a wafer and comparing the measured reflectance to a calculated reflectance or a reflectance stored in a database. Another exemplary method (800) includes positioning a wafer on a reflecting support to extend a reflectance range. An exemplary device (200) has an input (210), analysis modules (222-228) and optionally a database (230). Various exemplary reflectometer chambers (1300, 1400) include radiation sources positioned at a first altitudinal angle (1308, 1408) and at a second altitudinal angle (1312, 1412). An exemplary method includes selecting radiation sources positioned at various altitudinal angles. An exemplary element (1650, 1850) includes a first aperture (1654, 1854) and a second aperture (1658, 1858) that can transmit reflected radiation to a fiber and an imager, respectfully.

  3. Adaptive Mesh Refinement for Characteristic Grids

    E-print Network

    Jonathan Thornburg

    2010-05-14

    I consider techniques for Berger-Oliger adaptive mesh refinement (AMR) when numerically solving partial differential equations with wave-like solutions, using characteristic (double-null) grids. Such AMR algorithms are naturally recursive, and the best-known past Berger-Oliger characteristic AMR algorithm, that of Pretorius & Lehner (J. Comp. Phys. 198 (2004), 10), recurses on individual "diamond" characteristic grid cells. This leads to the use of fine-grained memory management, with individual grid cells kept in 2-dimensional linked lists at each refinement level. This complicates the implementation and adds overhead in both space and time. Here I describe a Berger-Oliger characteristic AMR algorithm which instead recurses on null \\emph{slices}. This algorithm is very similar to the usual Cauchy Berger-Oliger algorithm, and uses relatively coarse-grained memory management, allowing entire null slices to be stored in contiguous arrays in memory. The algorithm is very efficient in both space and time. I describe discretizations yielding both 2nd and 4th order global accuracy. My code implementing the algorithm described here is included in the electronic supplementary materials accompanying this paper, and is freely available to other researchers under the terms of the GNU general public license.

  4. Time of Time

    NASA Astrophysics Data System (ADS)

    Allen Emerson, E.

    In his landmark 1977 paper "The Temporal Logic of Programs", Amir Pnueli gave a fundamental recognition that the ideally nonterminating behavior of ongoing concurrent programs, such as operating systems and protocols, was a vital aspect of program reasoning. As classical approaches to program correctness were based on initial-state/final-state semantics for terminating programs, these approaches were inapplicable to programs where infinite behavior was the norm. To address this shortcoming, Pnueli suggested the use of temporal logic, a formalism for reasoning about change over time originally studied by philosophers, to meaningfully describe and reason about the infinite behavior of programs. This suggestion turned out to be remarkably fruitful. It struck a resonant chord within the formal verification community, and it has had an enormous impact on the development of the area. It matured into an extremely effective mathematical tool for specifying and verifying a vast class of synchronization and coordination problems common in concurrency. Pnueli thus caused a sea-change in the field of program verification, founding the time of reasoning about time, which has been the most successful period in formal methods yet.

  5. Three-dimensional modeling of diesel engine intake flow, combustion and emissions

    SciTech Connect

    Reitz, R.D.; Rutland, C.J. [Wisconsin Univ., Madison, WI (United States). Engine Research Center

    1992-03-01

    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/well 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 have been 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 data, comparisons have been made with measured engine cylinder pressure and heat flux data for homogeneous charge, spark-ignited and compression-ignited engines, and also limited comparisons for diesel engines. The model results are in good agreement with the experiments.

  6. Three-dimensional modeling of diesel engine intake flow, combustion and emissions

    SciTech Connect

    Reitz, R.D.; Rutland, C.J. (Wisconsin Univ., Madison, WI (United States). Engine Research Center)

    1992-03-01

    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/well 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 have been 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 data, comparisons have been made with measured engine cylinder pressure and heat flux data for homogeneous charge, spark-ignited and compression-ignited engines, and also limited comparisons for diesel engines. The model results are in good agreement with the experiments.

  7. Electrical environmental characteristics for automotive electric systems

    Microsoft Academic Search

    Shin Yamamoto; OSAMU OZEKI; TERUO YAMANAKA; HIROSHI KONDO

    1983-01-01

    The electrical environment is one of the most important factors in the design of high reliability electronic systems mounted on automobiles. Studies were made of the generation mechanisms and characteristics of both transients and high-frequency conducted noise generated in automotive electrical components. The high-frequency conducted noise data were obtained in terms of amplitude-frequency through real-time statistical treatment of the acquired

  8. The Characteristics Method and Cusped Flame Fronts

    Microsoft Academic Search

    F. BAILLOT; A. BOUREHLA; D. DUROX

    1996-01-01

    The kinematic effects of a space-time forced velocity field upon a thin premixed flame, stabilized above a circular cross-section burner, are studied in order to point out the non-linearities due to a sufficiently high velocity perturbation level whose RMS amplitudes remain nonetheless inferior to the normal burning velocity. The present calculation proposes to seek a solution using the characteristics method,

  9. Characteristics of mode-coupled lasers

    Microsoft Academic Search

    M. Crowell

    1965-01-01

    The effects of mode-coupling in a gas laser resulting from a time-varying loss within the optical cavity or from the non-linear characteristics of the inverted population are investigated both theoretically and experimentally. The dominant effect resulting from this mode-coupling is that the laser operates as a pulse regenerative oscillator which produces a periodic train of subnanosecond width pulses. The exact

  10. Uses And Characteristics Of Dynamic Tradeoff Evaluation

    NASA Technical Reports Server (NTRS)

    Schwuttke, Ursula M.

    1995-01-01

    Report discusses basic concepts, some applications, and performance characteristics of dynamic tradeoff evaluation (DTE). Basic concepts of DTE also described in "Dynamic Restructuring of Problems in Artificial Intelligence" (NPO-18488). DTE is method of enhancing real-time performance of artificial-intelligence system such as might be used to monitor data from multiple sensors in factory, aircraft, spacecraft, or other complex system of equipment. Report presents evaluation of DTE as applied to spacecraft-monitoring problems.

  11. Radiographic amplifier screens: Fabrication process and characteristics

    NASA Technical Reports Server (NTRS)

    Szepesi, Z. P.

    1977-01-01

    The fabrication process and transfer characteristics for solid state radiographic image transducers (radiographic amplifier screens) is described. These screens were developed for use in real time nondestructive evaluation procedures that require large format radiographic images with contrast and resolution capabilities unavailable with conventional fluoroscopic screens. This work was directed toward screens usable for inmotion, on-line radiographic inspection by means of closed circuit television.

  12. Characteristics of flight simulator visual systems

    NASA Technical Reports Server (NTRS)

    Statler, I. C. (editor)

    1981-01-01

    The physical parameters of the flight simulator visual system that characterize the system and determine its fidelity are identified and defined. The characteristics of visual simulation systems are discussed in terms of the basic categories of spatial, energy, and temporal properties corresponding to the three fundamental quantities of length, mass, and time. Each of these parameters are further addressed in relation to its effect, its appropriate units or descriptors, methods of measurement, and its use or importance to image quality.

  13. Characteristic Scales During Reionization

    E-print Network

    Steven R. Furlanetto; Matthew McQuinn; Lars Hernquist

    2005-11-23

    One of the key observables of the reionization era is the distribution of neutral and ionized gas. Recently, Furlanetto, Zaldarriaga, & Hernquist developed a simple analytic model to describe the growth of HII regions during this era. Here, we examine some of the fundamental simplifying assumptions behind this model and generalise it in several important ways. The model predicts that the ionized regions attain a well-defined characteristic size R_c that ranges from R_c~1 Mpc in the early phases to R_c>10 Mpc in the late phases. We show that R_c is determined primarily by the bias of the galaxies driving reionization; hence measurements of this scale constrain a fundamental property of the first galaxies. The variance around R_c, on the other hand, is determined primarily by the underlying matter power spectrum. We then show that increasing the ionizing efficiency of massive galaxies shifts R_c to significantly larger scales and decreases the importance of recombinations. These differences can be observed with forthcoming redshifted 21 cm surveys (increasing the brightness temperature fluctuations by up to a factor of two on large scales) and with measurements of small-scale anisotropies in the cosmic microwave background. Finally, we show that stochastic fluctuations in the galaxy population only broaden the bubble size distribution significantly if massive galaxies are responsible for most of the ionizing photons. We argue that the key results of this model are robust to many of our uncertainties about the reionization process.

  14. Sensor Characteristics Reference Guide

    SciTech Connect

    Cree, Johnathan V.; Dansu, A.; Fuhr, P.; Lanzisera, Steven M.; McIntyre, T.; Muehleisen, Ralph T.; Starke, M.; Banerjee, Pranab; Kuruganti, T.; Castello, C.

    2013-04-01

    The Buildings Technologies Office (BTO), within the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE), is initiating a new program in Sensor and Controls. The vision of this program is: • Buildings operating automatically and continuously at peak energy efficiency over their lifetimes and interoperating effectively with the electric power grid. • Buildings that are self-configuring, self-commissioning, self-learning, self-diagnosing, self-healing, and self-transacting to enable continuous peak performance. • Lower overall building operating costs and higher asset valuation. The overarching goal is to capture 30% energy savings by enhanced management of energy consuming assets and systems through development of cost-effective sensors and controls. One step in achieving this vision is the publication of this Sensor Characteristics Reference Guide. The purpose of the guide is to inform building owners and operators of the current status, capabilities, and limitations of sensor technologies. It is hoped that this guide will aid in the design and procurement process and result in successful implementation of building sensor and control systems. DOE will also use this guide to identify research priorities, develop future specifications for potential market adoption, and provide market clarity through unbiased information

  15. Autoignition characteristics of no. 2 diesel fuel

    NASA Technical Reports Server (NTRS)

    Tevelde, J. A.; Spadaccini, L. J.

    1981-01-01

    Parametric tests to map the ignition delay characteristics were conducted at pressures of 3, 4, and 5 atm, inlet air temperatures up to 1150 K and fuel air equivalence ratios ranging from 0.2 to 1.0. Ignition delay times in the range of 6 msec to 60 msec at freestream flow velocities ranging from 10 m/sec to 40 m/sec were obtained. The ignition delay times appeared to correlate with the inverse of pressure and the inverse exponent of temperature.

  16. Autoignition characteristics of no. 2 diesel fuel

    NASA Astrophysics Data System (ADS)

    Tevelde, J. A.; Spadaccini, L. J.

    1981-06-01

    Parametric tests to map the ignition delay characteristics were conducted at pressures of 3, 4, and 5 atm, inlet air temperatures up to 1150 K and fuel air equivalence ratios ranging from 0.2 to 1.0. Ignition delay times in the range of 6 msec to 60 msec at freestream flow velocities ranging from 10 m/sec to 40 m/sec were obtained. The ignition delay times appeared to correlate with the inverse of pressure and the inverse exponent of temperature.

  17. Characterization of Neonatal Personnel Time Inputs and Prediction From Clinical Variables — A Time and Motion Study

    Microsoft Academic Search

    John A F Zupancic; Douglas K Richardson

    2002-01-01

    OBJECTIVE: To characterize and predict personnel time inputs to neonatal intensive care using infant characteristics from chart review.STUDY DESIGN: For 12 hours each day, observers timed all direct care, charting, discussions, and procedures for 154 infants. Time inputs were correlated with 40 infant characteristics and resource markers, as well as the Score for Neonatal Acute Physiology (SNAP) for that day

  18. SYMBOLS FOR TIME = time variable

    E-print Network

    Duchowski, Andrew T.

    SYMBOLS FOR TIME = time variable t = time now, T = target date T* = modeling limit (t=forever) Cost spent to build variation point i at time i = index over variation points #12;SYMBOLS FOR TIME = time variable t = time now, T = target date T* = modeling limit (t=forever) ...adjusted by a factor

  19. Characteristics Data Base

    SciTech Connect

    Lewis, E.D.; Moore, R.S. (Automated Sciences Group, Inc., Oak Ridge, TN (USA))

    1990-08-01

    The LWR Serial Numbers Database System (SNDB) contains detailed data about individual, historically discharged LWR spent fuel assemblies. This data includes the reactor where used, the year the assemblies were discharged, the pool where they are currently stored, assembly type, burnup, weight, enrichment, and an estimate of their radiological properties. This information is distributed on floppy disks to users in the nuclear industry to assist in planning for the permanent nuclear waste repository. This document describes the design and development of the SNDB. It provides a complete description of the file structures and an outline of the major code modules. It serves as a reference for a programmer maintaining the system, or for others interested in the technical detail of this database. This is the initial version of the SNDB. It contains historical data through December 31, 1987, obtained from the Energy Information Administration (EIA). EIA obtains the data from the utility companies via the RW-859 Survey Form. It evaluates and standardizes the data and distributes the resulting batch level database as a large file on magnetic tape. The Characteristics Data Base obtains this database for use in the LWR Quantities Data Base. Additionally, the CDB obtains the individual assembly level detail from EIA for use in the SNDB. While the Quantities Data Base retains only the level of detail necessary for its reporting, the SNDB does retain and use the batch level data to assist in the identification of a particular assembly serial number. We expect to update the SNDB on an annual basis, as new historical data becomes available.

  20. LASERS: Study of characteristics of single-frequency GaAs\\/AlGaAs semiconductor lasers

    Microsoft Academic Search

    V. D. Kurnosov; K. V. Kurnosov; Roman V. Chernov

    2002-01-01

    The characteristics of single-frequency lasers are investigated experimentally and theoretically. It is shown that the model of spectral hole burning with a varying interband relaxation time adequately describes the spectral and modulation characteristics of the laser (taking into account the transport of carriers). The time of carrier capture in a quantum well is 4 ps and the time of their

  1. Modeling urban runoff characteristics 

    E-print Network

    Garcia, Alfred

    1987-01-01

    . Comparison of the Computed and Observed Hydrographs. . 18 5. Unit Hydrographs for a Channel n = 0. 05. . . 6. Unit Hydrographs for a Channel n = 0. 10. . . 7. Unit Hydrographs for a Channel n = 0. 15. . . 21 22 23 8. Peak Discharge versus Percent... a ~ t ~+em ~ e e 0 20 40 60 80 100 120 140 160 TIme (Minutes) FIG. 4. -Comparison of the Computed and Observed Hydrographs 19 the magnitude of the observed peak discharge was measured as 89 cfs. This 1s a difference of approximately 5. 6X...

  2. Time Constraints Verification Methods Based on Time Petri Nets

    Microsoft Academic Search

    Joel Toussaint; Françoise Simonot-lion; Jean-pierre Thomesse

    1997-01-01

    The study is concerned with the development of real time distributed applications and more precisely with the verification of temporal properties in a distributed context (taking into account the characteristics of the real architecture). We show how to use a time Petri net based model of the application in order to prove that a communication system (networks, protocols) and a

  3. Gases: Characteristics and Properties

    NSDL National Science Digital Library

    Brieske, Joel A.

    The first site related to ideal gas, called Ideal and Real Gas Laws, is maintained by Liina Ladon of Townsen University (1). Visitors can read about the properties of ideal gases, what the ideal gas law is, how to use it, and much more. The next site, titled Gas Laws, (2) is offered by the Ohio State University Department of Chemistry. This interactive site contains Shockwave movies of animations and audio files that describe what a gas is, the Ideal Gas Law equation, mixtures of gases, and problems using the ideal gas law. The University of Oregon site, Virtual Laboratory, teaches about the ideal gas law on the Welcome to the Pressure Chamber page (3). Those who enjoy online interaction will enjoy being able to control the action of a piston in a pressure chamber to see how the gases inside react. The fourth site includes another fun multimedia activity related to ideal gases provided by the Department of Physics and Astronomy at Western Washington University. The Air Filled Balloon in Liquid Nitrogen (4) movie shows an actual experiment of the effects on a balloon that's covered with liquid nitrogen. The page contains some additional information on the science behind the observations. The next site, called Ideal Gas Equations (5) is an online calculator that's part of Kean University's Department of Geology and Meteorology Web site. Users can calculate the pressure, volume, or temperature of a gas by inputting known variables into the various forms. Several methods and variations of calculating the values are provided as well as brief instructions. The next page from North Carolina State University's Basic Concepts in Environmental Science Web site is called Characteristics of Gases (6). Part of a larger learning module, the lesson plans objective is to use the ideal gas law to determine gas volumes at different absolute temperatures and absolute pressures. Everything needed to conduct the activity is provided including links to a volume calculator and practice problems. The seventh site is another animation that illustrates how gases react, called Molecular Model for an Ideal Gas (7). By changing the number of molecules in the chamber, their velocity, and the pressure and width of the container, users get to see how the molecules react to the conditions. The last site, Gases and Their Properties, is maintained by the Electronic Teaching Assistance Program(8). Students learn about the history of gas science, how gas laws describe ideal gases, what Dalton's Law and Graham's Law are, and much more.

  4. Trend of airplane flight characteristics

    NASA Technical Reports Server (NTRS)

    Von Koppen, Joachim

    1933-01-01

    This report describes the development of airplane characteristics since the war and indicates the direction development should take in the immediate future. Some of the major topics include: the behavior of an airplane about its lateral, vertical, and longitudinal axes. Behavior at large angles of attack and landing characteristics are also included.

  5. Perceptual Characteristics of Female Voices.

    ERIC Educational Resources Information Center

    Batstone, Susan; Tuomi, Seppo K.

    1981-01-01

    Male and females listeners rated 21 young female voices on seven scales representing unique vocal features. Voices were described as "passive", or traditionally female, and "active," characterized as "lively,""colorful," and "sexy." Females found active characteristics more salient; males preferred the passive characteristics. Implications for…

  6. Neck characteristic parameters mathematical model

    Microsoft Academic Search

    Lijun Jiang; Wenbin Zhang; Ming Xia; Xuanyi Hou

    2008-01-01

    This study aims to develop some neck characteristic parameters and to build virtual neck model of individual that can be used in the collar design of virtual fashion design. Through principal component factor analysis for the 3D neck anthropometric measurements of 200 female graduate students aged between 22 and 27, the paper presents some neck characteristic parameters, such as neck

  7. A Taxonomy of Usability Characteristics

    E-print Network

    Gabbard, Joseph L.

    A Taxonomy of Usability Characteristics in Virtual Environments Deliverable to Office of Naval This document can be found at http://csgrad.cs.vt.edu/jgabbard/ve/taxonomy/ #12;#12;A Taxonomy of Usability accomplished, yielding a comprehensive multi-dimensional taxonomy of usability characteristics specifically

  8. Voltage/temperature charge characteristics

    NASA Technical Reports Server (NTRS)

    Betz, F. E.

    1978-01-01

    A series of nickel cadmium batteries were tested to determine the effects of boltages and various temperatures on the charge discharge ratios and the recharge percentage. It was concluded that the selection of a proper temperature should consider the satellite orbit characteristics, the cell operating characteristics, the battery operating temperature range, and the final taper charge current.

  9. High-power laser-beam characteristics

    NASA Astrophysics Data System (ADS)

    Isarie, Claudiu; Isarie, Ilie

    2004-06-01

    Applications of high-power lasers are very important, especially for cutting and welding. As it is known, laser-beam characteristics have not constant value in time. So we may have suitable testing methods which allow us to determine the principal beam characteristics. The testing methods have to be very accurate, very efficient and in the same time very short as duration. We must apply a 3-dimensional intensity analysis, to the photonic beam we are studying. The number of industrial applications of lasers is increasing. An important thing is to know the optical characteristics of the laser that we study. Only the complete knowledge of the laser parameters allows controlling the process. For each laser system is very important to know the parameters i.e. their dynamic, in order to establish the correct performances. The correct information about the beam is not always possible to obtain. Various physical models help to understand the behavior of the laser beam. The best is if we have complete quantitative information about the photon beam. The definition of the beam diameter is not standardized. In order to do a comparison between different lasers, it is important to know the method that was applied to determine the beam diameter.

  10. The Variance Reaction Time Model

    ERIC Educational Resources Information Center

    Sikstrom, Sverker

    2004-01-01

    The variance reaction time model (VRTM) is proposed to account for various recognition data on reaction time, the mirror effect, receiver-operating-characteristic (ROC) curves, etc. The model is based on simple and plausible assumptions within a neural network: VRTM is a two layer neural network where one layer represents items and one layer…

  11. Measuring spatial variability in soil characteristics

    DOEpatents

    Hoskinson, Reed L. (Rigby, ID); Svoboda, John M. (Idaho Falls, ID); Sawyer, J. Wayne (Hampton, VA); Hess, John R. (Ashton, ID); Hess, J. Richard (Idaho Falls, ID)

    2002-01-01

    The present invention provides systems and methods for measuring a load force associated with pulling a farm implement through soil that is used to generate a spatially variable map that represents the spatial variability of the physical characteristics of the soil. An instrumented hitch pin configured to measure a load force is provided that measures the load force generated by a farm implement when the farm implement is connected with a tractor and pulled through or across soil. Each time a load force is measured, a global positioning system identifies the location of the measurement. This data is stored and analyzed to generate a spatially variable map of the soil. This map is representative of the physical characteristics of the soil, which are inferred from the magnitude of the load force.

  12. Characteristics of gamma-ray line flares

    NASA Technical Reports Server (NTRS)

    Bai, T.; Dennis, B.

    1983-01-01

    Observations of solar gamma rays by the Solar Maximum Mission (SMM) demonstrate that energetic protons and ions are rapidly accelerated during the impulsive phase. To understand the acceleration mechanisms for these particles, the characteristics of the gamma ray line flares observed by SMM were studied. Some very intense hard X-ray flares without detectable gamma ray lines were also investigated. Gamma ray line flares are distinguished from other flares by: (1) intense hard X-ray and microwave emissions; (2) delay of high energy hard X-rays; (3) emission of type 2 and/or type 4 radio bursts; and (4) flat hard X-ray spectra (average power law index: 3.1). The majority of the gamma ray line flares shared all these characteristics, and the remainder shared at least three of them. Positive correlations were found between durations of spike bursts and spatial sizes of flare loops as well as between delay times and durations of spike bursts.

  13. Anomalous Characteristics of a PVDC Carbon Adsorbant

    NASA Astrophysics Data System (ADS)

    Wexler, Carlos; Beckner, Matthew; Romanos, Jimmy; Rash, Tyler; Pfeifer, Peter; Olsen, Raina

    2011-03-01

    Nanoporous carbon produced by the pyrolisis of poly(vinylidene chloride-co-vinyl chloride) shows remarkably high adsorption of molecular hydrogen despite its relatively low surface area. In particular, its room temperature volumetric storage is significantly higher than other carbons with surface areas four times higher. In this talk we will present experimental hydrogen adsorption isotherms (and low-temperature isosteric heats of adsorption), subcritical nitrogen adsorption, real space images (TEM), and inelastic neutron scattering. In all cases, the sample characteristics are quite unusual. Whereas the sample under consideration is quite unusual in its high hydrogen sorption capacity, other samples in the literature also show similar unusual characteristics, suggesting the presence of phenomena not fully understood by standard adsorption theory. This material is based upon work supported in part by the Department of Energy under Award Nos. DE-FG02-07ER46411, DE-FG36-08GO18142, and DE-AC02-06CH11357.

  14. Analytic prediction of airplane equilibrium spin characteristics

    NASA Technical Reports Server (NTRS)

    Adams, W. M., Jr.

    1972-01-01

    The nonlinear equations of motion are solved algebraically for conditions for which an airplane is in an equilibrium spin. Constrained minimization techniques are employed in obtaining the solution. Linear characteristics of the airplane about the equilibrium points are also presented and their significance in identifying the stability characteristics of the equilibrium points is discussed. Computer time requirements are small making the method appear potentially applicable in airplane design. Results are obtained for several configurations and are compared with other analytic-numerical methods employed in spin prediction. Correlation with experimental results is discussed for one configuration for which a rather extensive data base was available. A need is indicated for higher Reynolds number data taken under conditions which more accurately simulate a spin.

  15. 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.

  16. Characteristics of sheltered homeless families.

    PubMed Central

    Bassuk, E L; Rubin, L; Lauriat, A S

    1986-01-01

    To describe the characteristics of homeless families, we interviewed 80 homeless mothers and 151 children living in 14 family shelters in Massachusetts (two-thirds of the shelters in the state). Ninety-four per cent of the families were headed by women, 91 per cent were on AFDC (aid to families with dependent children), with twice as many as the state average having been on AFDC for at least two years; most had long histories of residential instability. Although 60 per cent had completed high school, only a third had worked for longer than one month. One-third of the mothers reported having been abused during their childhood, and two-thirds had experienced a major family disruption. At the time of the interview, almost two-thirds either lacked or had minimal supportive relationships and one-fourth of these named their child as the major support. Eighteen mothers were involved with the Department of Social Services because of probable child abuse or neglect. Seventy-one per cent of the mothers had personality disorders. In contrast to many adult homeless individuals, however, deinstitutionalized persons or those suffering from psychoses were not overrepresented. About 50 percent of the homeless children were found to have developmental lags, anxiety, depression, and learning difficulties, and about half required further psychiatric evaluation. Two-thirds described housing and social welfare agencies as not helpful. Given the many serious problems of the mothers and the difficulties already manifested by their children, comprehensive psychosocial and economic interventions must be made to interrupt a cycle of extreme instability and family breakdown. PMID:3740332

  17. Characteristics of synchrotron radiation

    SciTech Connect

    Thomlinson, W.

    1984-01-01

    Synchrotron radiation is having a very significant impact on the many disciplines that make use of the radiation in the x-ray, vacuum ultraviolet, and infra-red regions of the spectrum. The rapidly increasing demand for beam time at existing facilities, the construction and commissioning of new facilities, and the world wide planning for future sources is clear testimony to the unique, interdisciplinary nature of the research applications. The nature of synchrotron radiation research continues to change and expand. This conference on the application of synchrotron radiation (SR) to polymer research illustrates that point. In this introductory paper it is impossible to cover in depth any of the applications. The intent, instead, is to give a brief, condensed summary of the properties of SR which have brought it to the fore as a research tool. No single source can provide the proper radiation for all applications. This paper should provide enough information and references to allow anyone contemplating a particular experiment to understand the widely varying parameters from different facilities, and thereby make some initial decisions concerning feasibility, and proper source. The NSLS will, in general, be used for illustration purposes since the conference is being held at Brookhaven where the attendees can get first hand familiarity with the facility.

  18. Simulation and Experimental Investigation of Structural Dynamic Frequency Characteristics Control

    PubMed Central

    Zhang, Xingwu; Chen, Xuefeng; You, Shangqin; He, Zhengjia; Li, Bing

    2012-01-01

    In general, mechanical equipment such as cars, airplanes, and machine tools all operate with constant frequency characteristics. These constant working characteristics should be controlled if the dynamic performance of the equipment demands improvement or the dynamic characteristics is intended to change with different working conditions. Active control is a stable and beneficial method for this, but current active control methods mainly focus on vibration control for reducing the vibration amplitudes in the time domain or frequency domain. In this paper, a new method of dynamic frequency characteristics active control (DFCAC) is presented for a flat plate, which can not only accomplish vibration control but also arbitrarily change the dynamic characteristics of the equipment. The proposed DFCAC algorithm is based on a neural network including two parts of the identification implement and the controller. The effectiveness of the DFCAC method is verified by several simulation and experiments, which provide desirable results. PMID:22666072

  19. IRRADIATION EFFECTS ON THE PHYSICAL CHARACTERISTICS OF SEWAGE SLUDGE

    SciTech Connect

    Lee, M-J.; Lee, J-K.; Yoo, D-H.; Ho, K.

    2004-10-05

    The radiation effects on the physical characteristic of the sewage sludge were studied in order to obtain information which will be used for study on the enhancement of the sludge's dewaterability. Water contents, capillary suction time, zeta potential, irradiation dose, sludge acidity, total solid concentration, sludge particle size and microbiology before and after irradiation were investigated. Irradiation gave an effect on physical characteristics sludge. Water content in sludge cake could be reduced by irradiation at the dose of 10kGy.

  20. Financial characteristics of hospitals purchased by investor-owned chains.

    PubMed Central

    McCue, M J; Furst, R W

    1986-01-01

    This article focuses on the preacquisition financial condition of not-for-profit hospitals acquired by investor-owned hospital chains. Financial ratios are used to determine if not-for-profit hospitals acquired by investor-owned hospital systems have common financial characteristics which make them a likely target for a takeover. The results indicate that during the time period studied, investor-owned hospital systems did tend to purchase hospitals with common financial characteristics and that these characteristics provide a reasonable description of a financially distressed hospital. This finding has important consequences for our health care delivery system. PMID:3771232

  1. Virtual time

    Microsoft Academic Search

    David R. Jefferson

    1985-01-01

    Virtual time is a new paradigm for organizing and synchronizing distributed systems which can be applied to such problems as distributed discrete event simulation and distributed database concurrency control. Virtual time provides a flexible abstraction of real time in much the same way that virtual memory provides an abstraction of real memory. It is implemented using the Time Warp mechanism,

  2. 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…

  3. Dynamic analysis of evaporator characteristics

    Microsoft Academic Search

    Jae-Dol Kim; Jung-In Yoon; Hag-Geun Ku

    1997-01-01

    An analysis of the dynamic characteristics in an evaporator was numerically performed for control and design of the refrigeration\\u000a and air conditioning systems. The important factors, such as refrigerant flow rate, inlet enthalpy, inlet air velocity and\\u000a air temperature, are incorporated with this analysis. An evaporator is modeled for the dynamic characteristics analysis separated\\u000a into three regions which are the

  4. Heat transfer characteristics of an emergent strand

    NASA Technical Reports Server (NTRS)

    Simon, W. E.; Witte, L. C.; Hedgcoxe, P. G.

    1974-01-01

    A mathematical model was developed to describe the heat transfer characteristics of a hot strand emerging into a surrounding coolant. A stable strand of constant efflux velocity is analyzed, with a constant (average) heat transfer coefficient on the sides and leading surface of the strand. After developing a suitable governing equation to provide an adequate description of the physical system, the dimensionless governing equation is solved with Laplace transform methods. The solution yields the temperature within the strand as a function of axial distance and time. Generalized results for a wide range of parameters are presented, and the relationship of the results and experimental observations is discussed.

  5. Coal-water slurry atomization characteristics

    SciTech Connect

    Caton, J.A.; Kihm, K.D.

    1994-04-01

    The overall objective of this work was to fully characterize the CWS fuel sprays of a medium-speed diesel engine injection system. Specifically, the spray plume penetration as a function of time was determined for a positive-displacement fuel injection system. The penetration was determined as a function of orifice diameter, coal loading, gas density in the engine, and fuel line pressure. Preliminary droplet information also was obtained. The results of this study will assist CWS engine development by providing much needed insight about the fuel spray. In addition, the results will aid the development and use of CWS engine cycle simulations which require information on the fuel spray characteristics.

  6. [Characteristics analysis of human tongue reflectance spectra].

    PubMed

    Zhao, Jing; Liu, Ming; Lu, Xiao-zuo; Li, Gang

    2014-08-01

    The present paper presents the spectroscopic analysis method. Eighty samples of spectra data of tongue parts with coating and without coating were collected by Usb4000 spectrometer of Ocean Optics, then comparing the spectra data of the different parts of tongue we found that there was a relation between the spectra characteristics and tongue coating, and further analysis of the spectra data showed that there was a big difference between the two parts within the wavelength range between 500 and 600 nm. It was also found that the biggest differences appear when the wavelength is 579.39 nm, and at the same time, different colors of tongue coating were also compared, and the spectrum was also quite different because of different color and thickness of the tongue coating. The experiment results show that different color, thickness, and dryness of the human tongue coating lead to different spectral characteristics, and compared with the current colorimetric method of tongue characterization, spectral reflectance can reflect more physiological and pathological information. The experiment results also indicated that the different spectral characteristics of tongue property and tongue coating will be used for further separation of these two parts, and to provide an objective analysis index for tongue coating qualitative and quantitative analysis, so as to promote the objectivity of the TCM. PMID:25508742

  7. [Characteristics analysis of human tongue reflectance spectra].

    PubMed

    Zhao, Jing; Liu, Ming; Lu, Xiao-zuo; Li, Gang

    2014-08-01

    The present paper presents the spectroscopic analysis method. Eighty samples of spectra data of tongue parts with coating and without coating were collected by Usb4000 spectrometer of Ocean Optics, then comparing the spectra data of the different parts of tongue we found that there was a relation between the spectra characteristics and tongue coating, and further analysis of the spectra data showed that there was a big difference between the two parts within the wavelength range between 500 and 600 nm. It was also found that the biggest differences appear when the wavelength is 579.39 nm, and at the same time, different colors of tongue coating were also compared, and the spectrum was also quite different because of different color and thickness of the tongue coating. The experiment results show that different color, thickness, and dryness of the human tongue coating lead to different spectral characteristics, and compared with the current colorimetric method of tongue characterization, spectral reflectance can reflect more physiological and pathological information. The experiment results also indicated that the different spectral characteristics of tongue property and tongue coating will be used for further separation of these two parts, and to provide an objective analysis index for tongue coating qualitative and quantitative analysis, so as to promote the objectivity of the TCM. PMID:25474963

  8. TIME MANAGEMENT Time Management Questionnaire

    E-print Network

    TIME MANAGEMENT WORKSHOP #12;2 Time Management Questionnaire Self Assessment: Answer "Yes" or "No you tend to complete your assignments on time? 3. ____ Have you estimated how long it takes to read schedule time to study for exams? 8. ____ Do you have a job that requires more than 20 hours a week? 9

  9. Noise in pulsar timing arrays

    NASA Astrophysics Data System (ADS)

    Wang, Yan

    2015-05-01

    To successfully detect gravitational waves with pulsar timing arrays, we need to have a comprehensive understanding of the physical origins and statistical characteristics of the noise in pulse arrival times and identify mitigation methods to reduce the noise. In this paper we will review radiometer noise, phase jitter noise and timing noise in the noise budget of pulsar timing and show various efforts used to reduce them. We will briefly discuss the results of an overall assessment of the components and physical causes of the timing residuals for millisecond pulsars in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav).

  10. Noise in pulsar timing arrays

    E-print Network

    Wang, Yan

    2015-01-01

    To successfully detect gravitational waves with pulsar timing arrays, we need to have a comprehensive understanding of the physical origins and statistical characteristics of the noise in pulse arrival times and identify mitigation methods to reduce the noise. In this paper we will review radiometer noise, phase jitter noise and timing noise in the noise budget of pulsar timing and show various efforts used to reduce them. We will briefly discuss the results of an overall assessment of the components and physical causes of the timing residuals for millisecond pulsars in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav).

  11. Elapsed Time

    NSDL National Science Digital Library

    2007-01-01

    This interactive Java applet allows the user to practice finding elapsed time using analog or digital clocks. Using the "See" mode the user advances a clock from the beginning time to the ending time and the applet calculates the elapsed time. Using the "Guess" mode, the user must calculate the elapsed time between the given beginning and ending times. Three difficulty levels allow the user to practice with hour, five minute, or single minute increments. An optional scoring feature allows the user to keep track of number correct, though this feature is optional.

  12. Characteristics of the Internet for criminal child sexual abuse by online groomers

    Microsoft Academic Search

    Julia Davidson; Petter Gottschalk

    2011-01-01

    This paper presents a number of characteristics of the Internet that makes it attractive to online groomers. Relevant Internet characteristics include disconnected personal communication, mediating technology, universality, network externalities, distribution channel, time moderator, low?cost standard, electronic double, electronic double manipulation, information asymmetry, infinite virtual capacity, independence in time and space, cyberspace, and dynamic social network. Potential sex offenders join virtual

  13. Regional characteristics of long-term sea level variations from satellite altimetry and tide gauges

    Microsoft Academic Search

    S. Barbosa; O. Andersen; P. Knudsen

    2006-01-01

    TOPEX\\/POSEIDON and JASON-1 sea level observations over the most recent 12 years have qualitatively been used to study regional characteristics in sea level variations over this period. EOFs of annual anomalies have been derived using different periods of time and compared. Furthermore, spatial characteristics have been derived for sea level slopes computed over different time intervals. Finally, Tide gauge data

  14. The causal relationships between job characteristics, burnout, and psychological health: a two-wave panel study

    Microsoft Academic Search

    Yu-Hwa Huang; Chin-Hui Chen; Pey-Lan Du; Ing-Chung Huang

    2012-01-01

    Researchers conducted a two-wave panel study to test the hypothesis of the normal and reversed causal relationships of job characteristics, burnout, and psychological health. The hypotheses are as follows: job characteristics lead to burnout and psychological health over time; and vice versa, burnout and psychological health were expected to result in perceived job stress over time. Nearly 513 participants were

  15. The causal relationships between job characteristics, burnout, and psychological health: a two-wave panel study

    Microsoft Academic Search

    Yu-Hwa Huang; Chin-Hui Chen; Pey-Lan Du; Ing-Chung Huang

    2011-01-01

    Researchers conducted a two-wave panel study to test the hypothesis of the normal and reversed causal relationships of job characteristics, burnout, and psychological health. The hypotheses are as follows: job characteristics lead to burnout and psychological health over time; and vice versa, burnout and psychological health were expected to result in perceived job stress over time. Nearly 513 participants were

  16. Thrombin Time

    MedlinePLUS

    ... tests: PT and INR ; PTT ; Reptilase Time ; Fibrinogen ; Coagulation Factors ; D-dimer ; Lupus Anticoagulant Testing At a ... miscarriages, or has unexplained prolonged results on primary coagulation tests such as prothrombin time (PT) or partial ...

  17. Evaluation of emergency ambulance characteristics under several criteria.

    PubMed Central

    Siler, K F

    1979-01-01

    A methodology and analysis are presented for evaluating response time characteristics of emergency ambulance systems. The methodology is based on a Monte Carlo simulation technique and a heuristic optimal-seeking technique for locating emergency ambulances under several criteria based on response time distribution. Optimization criteria include minimum mean system response time, minimum system fractile response time and minimum level-loaded response time. The evaluation methodology is applied to the metropolitan area of Los Angeles County. Ambulance response characteristics and loads are discussed in detail. From these results alternative dispatch polices can be evaluated. Complementing the analysis is a presentation of a sensitivity analysis and an analysis of existing ambulance sites. Unique to the methodology is the adaption of the heuristic optimal-seeking technique to include any of the three criteria and the effectiveness of the methodology for analyzing small or large ambulance systems. PMID:511579

  18. Sequencing Time

    NSDL National Science Digital Library

    2007-12-12

    In this activity, students gain an understanding of relative and numerical time by placing events in sequence and assigning relative times to the events. This will familarize them with the methods used by scientists to develop the geologic time scale. This activity contains objectives, materials, procedure, and extensions.

  19. Time lapse

    NSDL National Science Digital Library

    Olivia Worland (Purdue University; Biological Sciences)

    2008-06-16

    Time lapse videos and photography allow us to visualize parts of certain events that we wouldn't normally be able to piece together. Since decay takes time, the causal relationships of this phenomenon can be seen through the use of time lapse videos.

  20. Reaction Time

    NSDL National Science Digital Library

    New York Hall of Science

    1999-01-01

    In this activity, learners explore reaction time and challenge themselves to improve their coordination. Do you want to move faster? Catch that ball that you never seem to see in time? Use a simple test to help you improve your reaction (or response) time.

  1. Fluorescence spectroscopy characteristics of nasopharyngeal carcinoma cells

    NASA Astrophysics Data System (ADS)

    Li, Buhong; Zhang, Zhenxi; Xie, Shusen; Lin, Huiyun

    2005-01-01

    The spectroscopic characteristics of autofluorescence for the nasopharyngeal carcinoma in vitro and nasopharyngeal carcinoma cells (CNE cells) were investigated, respectively. The characteristics of fluorescence agree with the results that deduced from the nasopharyngeal carcinoma in vivo, and the optimal excitation-emission wavelength was found at 350-500 nm. Secondly, the selectivity and optimal time for optical diagnosis of nasopharyngeal carcinoma by using the new photosensitizer of Hematoporphyrin Monomethyl Ether (HMME) has been demonstrated and determined by incubated CNE cells with HMME. The fluorescence emission peaks of 615 and 675 nm characterized the selective accumulation of HMME in CNE cells, and the optimal time for optical diagnostics with HMME was about 140 mins after clinic intravenous administration. Moreover, when the concentration of HMME in CNE cells below 32 ?g/mL, the fluorescence intensity versus HMME concentration reveals an obvious linearity. Finally, the fluorescence intensity of CNE cells increases linearly with concentration over the entire range up to 9.0E+05 cells/mL. These results can be used to helpfully improve the accuracy of optical diagnosis for nasopharyngeal carcinoma.

  2. [Collage work characteristics and personality].

    PubMed

    Sato, Shizuka

    2002-06-01

    The purpose of this study was to investigate the relationship between personality and characteristics in collage work. Seventy undergraduates filled the Yatabe-Guilford (YG) personality test and produced a piece of collage work. The YG personality types were not different in terms of collage work characteristics. However, emotional adaptation and introvert/extrovert scores were reflected in the number of cuttings used in the piece. General activity score was reflected in the number of vehicle pictures used. Those who used an eye picture had a tendency to be depressed and lacking in confidence. Those who used a "stone circle" picture tended to be more emotionally adapted and extroverted. The results suggested a possibility that personality traits were reflected in specific characteristics in collage work. PMID:12199065

  3. Dynamic Characteristics of Retinal Ganglion Cell Responses in Goldfish

    PubMed Central

    Schellart, Nico A. M.; Spekreijse, Henk

    1972-01-01

    A cross-correlation technique has been applied to quantify the dependence of the dynamic characteristics of retinal ganglion cell responses in goldfish on intensity, wavelength, spatial configuration, and spot size. Both theoretical and experimental evidence justify the use of the cross-correlation procedure which allows the completion of rather extensive measurements in a relatively short time. The findings indicate the following. (a) The shape of the amplitude characteristics depends on the energy per unit of time (power) falling within the center of a receptive field rather than on the intensity of the stimulus spot. For spot diameters of up to 1 mm, identical amplitude characteristics can be obtained by interchanging area and intensity. Therefore the receptor processes do not contribute to the change in the amplitude characteristics as a function of the power of the stimulus light. (b) For high frequencies the amplitude characteristics obtained as a function of power join together in a common envelope if plotted on an absolute sensitivity scale. For spontaneous ganglion cells this envelope holds over a range of three log units and the shape is identical for central and peripheral processes. (c) The amplitude characteristics of the central and peripheral processes converging to a ganglion cell are identical, irrespective of the sign (on or off) and the spectral coding of the response. Therefore we have no evidence for interneurons in the goldfish retina unique to the periphery of the receptive field. PMID:5007262

  4. Progress towards diesel combustion modeling

    SciTech Connect

    Rutland, C.J.; Ayoub, N.; Han, Z. [Univ. of Wisconsin, Madison, WI (United States)] [and others

    1995-12-31

    Progress on the development and validation of a CFD model for diesel engine combustion and flow is described. A modified version of the KIVA code is used for the computations, with improved submodels for liquid breakup, drop distortion and drag, spray/wall impingement with rebounding, sliding and breaking-up drops, wall heat transfer with unsteadiness and compressibility, multistep kinetics ignition and laminar-turbulent characteristic time combustion models, Zeldovich NOx formation, and soot formation with Nagle Strickland-Constable oxidation. The code also considers piston-cylinder-liner crevice flows and allows computations of the intake flow process in the realistic engine geometry with two moving intake valves. Significant progress has been made using a modified RNG {kappa}-{var_epsilon} turbulence model, and a multicomponent fuel vaporization model and a flamelet combustion model have been implemented. Model validation experiments have been performed using a single-cylinder heavy duty truck engine that features state-of-the-art high pressure electronic fuel injection and emissions instrumentation. In addition to cylinder pressure, heat release, and emissions measurements, new combustion visualization experiments have also been performed using an endoscope system that takes the place of one of the exhaust valves. Modifications to the engine geometry for optical access were minimal, thus ensuring that the results represent the actual engine. The intake flow CFD modeling results show that the details of the intake flow process influence the engine performance. Comparisons with the measured engine cylinder pressure, heat release, soot and NOx emission data, and the combustion visualization flame images show that the CFD model results are generally in good agreement with the experiments. In particular, the model is able to correctly predict the soot-NOx trade-off trend as a function of injection timing. 44 refs., 21 figs., 6 tabs.

  5. Adjoint analysis for receptivity prediction

    Microsoft Academic Search

    Alexander Y. Dobrinsky

    2003-01-01

    Physical knowledge of the laminar-turbulent transition process, prediction of the transition location, as well as the ability to control transition are essential in many engineering applications. However, control of the laminar-turbulent transition depends critically on various environmental sources and their ability to excite the instability waves in the flow, which are responsible for the laminar-turbulent transition. The process by which

  6. Geosynchronous platform definition study. Volume 3: Geosynchronous mission characteristics

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The objectives of the study were to examine the nature of currently planned and new evolutionary geosynchronous programs, to analyze alternative ways of conducting missions, to establish concepts for new systems to support geosynchronous programs in an effective and economical manner, and to define the logistic support to carry out these programs. In order to meet these objectives, it was necessary to define and examine general geosynchronous mission characteristics and the potentially applicable electromagnetic spectrum characteristics. An organized compilation of these data is given with emphasis on the development and use of the data. Fundamental geosynchronous orbit time histories, mission profile characteristics, and delivery system characteristics are presented. In addition, electromagnetic spectrum utilization is discussed in terms of the usable frequency spectrum, the spectrum potentially available considering established frequency allocations, and the technology status as it affects the ability to operate within specific frequency bands.

  7. Highly segmented, high resolution time-of-flight system

    SciTech Connect

    Nayak, T.K.; Nagamiya, S.; Vossnack, O.; Wu, Y.D.; Zajc, W.A. [Columbia Univ., New York, NY (United States); Miake, Y.; Ueno, S.; Kitayama, H.; Nagasaka, Y.; Tomizawa, K.; Arai, I.; Yagi, K [Univ. of Tsukuba, (Japan)

    1991-12-31

    The light attenuation and timing characteristics of time-of-flight counters constructed of 3m long scintillating fiber bundles of different shapes and sizes are presented. Fiber bundles made of 5mm diameter fibers showed good timing characteristics and less light attenuation. The results for a 1.5m long scintillator rod are also presented.

  8. Characteristics of the Federal Executive.

    ERIC Educational Resources Information Center

    Civil Service Commission, Washington, DC.

    The personal characteristics, educational background, occupations, and attitudes of 54 Federal Executives who attended Session IX of the Federal Executive Institute, U. S. Civil Service Commission, are given. The average age of the group was 47.6 years (range 36 to 61). The federal grades were 18% in GS-5, 66% in GS-16 and equivalent, and 16% in…

  9. Tourette's Syndrome: Characteristics and Interventions.

    ERIC Educational Resources Information Center

    Prestia, Kelly

    2003-01-01

    This article overviews the characteristics of children and youth with Tourette syndrome and provides suggestions that can be used in the school setting for addressing academic concerns, social-emotional concerns, and physical concerns. Teachers are urged to break down assignments, allow computer use to complete work, and give preferential seating.…

  10. Dynamic characteristics of vortex levitation

    Microsoft Academic Search

    Xin Li; Kenji Kawashima; Toshiharu Kagawa

    2008-01-01

    Vortex levitation can achieve non-contact handling by blowing air into a vortex cup through a tangential nozzle to generate a swirling air flow. In this paper, its dynamic characteristics are analyzed and discussions are laid upon the behavior of a work piece at the moment when it is picked up by the vortex cup. From the dynamic handling experiment, it

  11. Partner Attachment and Interpersonal Characteristics

    Microsoft Academic Search

    Peter R. Kilmann; Holmes Finch; Michele M. Parnell; Jason T. Downer

    2012-01-01

    This study investigated partner attachment and interpersonal characteristics in 134 non-clinical couples in long-term marriages. Irrespective of gender, spouses with greater “anxiety over abandonment” or “discomfort with closeness” endorsed dysfunctional relationship beliefs to a greater extent. On the “anxiety over abandonment” dimension, husbands with higher scores were rated less aggressive, less controlling, and more rebellious, while wives with higher scores

  12. Artistic Understanding and Motivational Characteristics

    ERIC Educational Resources Information Center

    Lekue, Pablo

    2015-01-01

    This study aims to analyse artistic understanding in primary and secondary education and the relationship between this understanding and motivational characteristics such as goal orientation, engagement in art activities and attitude to art education at school, which determine (according to prior research) learners' academic achievement, in…

  13. Supervisor Accessibility and Job Characteristics.

    ERIC Educational Resources Information Center

    Dallinger, Judith M.; Hample, Dale

    A study examined the relationship between dyadic and normative accessibility of work supervisors and task characteristics of autonomy, variety, and identity (whether the task is part of a process or results in a finished product). Dyadic accessibility refers to workers' estimates of their supervisors' accessibility. Normative accessibility is the…

  14. Submarine Coaxial Cable Pressure Characteristics

    Microsoft Academic Search

    K. Aida; M. Aiki

    1978-01-01

    In equalization design of submarine coaxial cable system, the cable attenuation deviation due to pressure in deep sea bottom has significant weight. This paper treats the submarine coaxial cable characteristics pressure dependency. By using an artificial ocean test facility, 1.7 inch submarine coaxial cable attenuation, phase, capacitance and insulator core diameter were studied and their pressure coefficients under a pressure

  15. Characteristics of shared service centers

    Microsoft Academic Search

    Veit Schulz; Walter Brenner

    2010-01-01

    Purpose – Even though a lot of publications focusing on shared service center (SSC) exist, there is no unique understanding of the term “SSC”. The aim of this paper is to obtain an overview of definitions of the term “SSC” and an overview of relevant literature. It also aims to derive a common understanding with the help of SSC characteristics

  16. Characteristics of Echinacea seed oil

    Microsoft Academic Search

    B. Dave Oomah; Delphine Dumon; Anaberta Cardador-Martínez; David V. Godfrey

    2006-01-01

    Seed oils from three commonly cultivated Echinacea species, Echinacea Angustifolia, Echinacea Pallida and Echinacea Purpurea, harvested in 1998 and 1999, were evaluated for physicochemical characteristics. Oil yield ranged from 13% to 23%, depending on Echinacea species and seed weight. UV\\/VIS and fluorescence spectra distinguished Echinacea seed oil by species. Vitamin E content of the oils ranged from 29 to 85

  17. CHARACTERISTICS Picric acid is a

    E-print Network

    Wilcock, William

    CHARACTERISTICS · Picric acid is a trinitroaromatic compound that is a flammable solid when purchased wet with 30% water, by mass. · Picric acid is a high-powered explosive when allowed to dehydrate. As an explosive, picric acid is not shock sensitive, but when in contact with metals can form shock sensitive

  18. School Choice with Chinese Characteristics

    ERIC Educational Resources Information Center

    Wu, Xiaoxin

    2012-01-01

    This paper explores the major characteristics of school choice in the Chinese context. It highlights the involvement of cultural and economic capital, such as choice fees, donations, prize-winning certificates and awards in gaining school admission, as well as the use of social capital in the form of "guanxi". The requirement for these resources…

  19. PSYCHOLOGICAL CHARACTERISTICS AND INTERPERSONAL DISTANCE

    Microsoft Academic Search

    William J. Ickinger; Sandra Morris

    2001-01-01

    Locus of control and Mach IV scores are found to be correlated with standing interpersonal distancing behavior in a behavioral game. Correlations between interpersonal distance and factors of these scales suggest that interpersonal distance is not generally manipulated actively to influence others but that greater distance is used as a defense against perceived negative characteristics of others. Scores on Vando's

  20. Attitudes and Characteristics of Nonusers.

    ERIC Educational Resources Information Center

    Stein, Ann; Kahn, Malcolm

    The attitudes and life-style characteristics of 58 undergraduate nonusers of illegal drugs were evaluated through comparisons with 47 regular marijuana users. The nonusers were found to be more settled in their values, more goal-directed, and more involved academically. They also had higher Grade Point Averages. The nonusers appeared to be both…

  1. Persistence Characteristics of Stormwater BMPs

    E-print Network

    Characteristics Temperature Conductivity pH Dissolved Oxygen Turbidity Nutrients Organic Carbon #12;6 What Gross Solids 7 Impervious #12;The Initial Effects of Urbanization on Stream Channels Channel becomes 16 #12;Dry vs Wet Weather Water Quality (TON, Fecal Coli) Scatterplot of paired Fecal Coliform

  2. Concrete Pavement Surface Characteristics Program

    E-print Network

    Concrete Pavement Surface Characteristics Program Site Evaluation Report Site 211-1 (Pre- and Post- Grinding/Grooving, Pre-Traffic) Site 211-2 (Post-Traffic, 1 week) Two-Lift Concrete Paving Demonstration, near Solomon, Kansas Two-Lift Concrete Paving Demonstration Project Surface A, Longitudinal Tining

  3. Computerized Investigations of Battery Characteristics.

    ERIC Educational Resources Information Center

    Hinrichsen, P. F.

    2001-01-01

    Uses a computer interface to measure terminal voltage versus current characteristic of a variety of batteries, their series and parallel combinations, and the variation with discharge. The concept of an internal resistance demonstrates that current flows through the battery determine the efficiency and serve to introduce Thevenin's theorem.…

  4. Health-Compromising Behaviors characteristics

    E-print Network

    Meagher, Mary

    Health-Compromising Behaviors characteristics substance abuse and dependence alcohol abuse at once" ! Substance abuse of all kinds are predicted by some of the same factors ! Interventions need to be matched to stage of vulnerability #12;Substance abuse: Links ! Conflict with parents and family problems

  5. Perceived Characteristics of an Innovation.

    ERIC Educational Resources Information Center

    Holloway, Robert E.

    This study investigated the characteristics of an innovative cooperative high school-college program as perceived by principals of adopting and nonadopting schools. The data from survey questionnaires with 24 Likert-type items were reduced to six factors: observability, status, simplicity, cost, trialability, and relative…

  6. NIR optical characteristics of Deoxynivalenol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have developed rapid near infra red (NIR) techniques for nondestructive automatic sorting of Fusarium damaged wheat kernels and for estimation of deoxynivalenol (DON) levels in single wheat kernels. We studied NIR optical characteristics of DON to identify NIR absorption bands and to assess the a...

  7. BELLCOMM, INC. GEOLOGIC CHARACTERISTICS OF

    E-print Network

    Rathbun, Julie A.

    BELLCOMM, INC. GEOLOGIC CHARACTERISTICS OF THE NINE LUNAR LANDING MISSION SITES RECOMMENDED BY THE GROUP FOR LUNAR EXPLORATION PLANNING May 31, 1968 TR-68-340-1 Farouk EI-Baz Work performed for Office Landing Site for Hyginus Crater and Rille. . . . . . . Proposed Landing Site in the Littrow Area 12

  8. THE CHARACTERISTICS OF HARTNELL STUDENTS.

    ERIC Educational Resources Information Center

    SANDGREN, DUANE

    FOUR MAJOR STUDIES OF THE CHARACTERISTICS OF HARTNELL COLLEGE STUDENTS WERE MADE DURING THE 1965-66 YEAR. (1) SCORES WERE REPORTED FOR A VARIETY OF ENTRANCE TESTS (AMERICAN COLLEGE TESTING PROGRAM, SCHOLASTIC APTITUDE TEST, SCHOOL AND COLLEGE ABILITY TESTS, COOPERATIVE ENGLISH TEST, AND DAVIS READING TEST), AND A PROFILE OF THE TYPICAL ENTERING…

  9. Propagation Characteristics of Boolean Functions

    Microsoft Academic Search

    Bart Preneel; Werner Van Leekwijck; Luc Van Linden; René Govaerts; Joos Vandewalle

    1990-01-01

    The relation between the Walsh-Hadamard transform and the autocorrelation function of Boolean functions is used to study propagation characteristics of these functions. The Strict Avalanche Criterion and the Perfect Nonlinearity Crite- rion are generalized in a Propagation Criterion of degree k. New properties and constructions for Boolean bent functions are given and also the extension of the deflnition to odd

  10. Geologic Time

    NSDL National Science Digital Library

    William L. Newman

    1997-01-01

    The Earth is very old -- 4.5 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.

  11. 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.

  12. Time Machine

    NSDL National Science Digital Library

    Larry Flammer

    In this lesson students will experience how geological and biological events have occurred in a clear sequence of vast but measured time. Students are taken on a simulated voyage backward in time, to the beginning of our planet. They witness that beginning, the origin of life, and a number of key events leading to the present. This becomes a dramatic experience, involving body and mind, helping students to relate physically at least to the relative timing of events in geological and biological history, if not to the absolute vastness of that time.

  13. A Class of Discrete Time Models for a Continuous Time System

    Microsoft Academic Search

    T. Mori; P. N. Nikiforuk; M. M. Gupta; N. Hori

    1987-01-01

    An equivalence class, called the T-equivalence class in this study, is introduced for discrete time models of a continuous time system such that any member of this class has the same input-output characteristics when the discrete time interval approaches zero. This concept provides a systematic way of viewing the various discrete time models including those already proposed in the literature.

  14. New Trends in Real Time Operating Systems

    Microsoft Academic Search

    Shraddha S. Nakate; B. Meshram; Jayamala P. Chavan

    2012-01-01

    Most of today's embedded systems are required to work in dynamic environments, where the characteristics of the computational load cannot always be predicted in advance. Still timely responses to events have to be provided within precise timing constraints in order to guarantee a desired level of performance. Hence, embedded systems are, by nature, inherently real-time. Moreover, most of embedded systems

  15. Identity verification by keystroke timing

    E-print Network

    Usnick, Mark C.

    1988-01-01

    . He proposed to associate a unique phrase with each individual and to use phrase content, time between keystrokes, and force of each keystroke as identifying attributes. However, such a system was never designed [Spillane 1984]. In 1977, the United.... The Garcia Investigation During the same time frame, a patent was granted to Garcia for a system similar to the one proposed by the Air Force in 1977 which would identify an individual based upon the typing characteristics shown when the user typed his...

  16. Part-Time Faculty Handbook.

    ERIC Educational Resources Information Center

    College of the Mainland, Texas City, TX.

    This document contains comprehensive information designed to orient the part-time faculty member to the College of the Mainland. Information included in the handbook covers the history and philosophy of the college; student and instructor rights; a description of social and economic characteristics of the students; a description of the faculty;…

  17. A Traffic Measurement System Using Time Synchronization Mechanism

    Microsoft Academic Search

    Toyonori Fujiura; Shozo Naito; Satoshi Ono

    1999-01-01

    This paper presents a time synchronization mechanism and its application to a multipoint traffic measurement system. The time synchronization system uses the time delivered from GPS as source and the ISDN for delivering the time to multipoints. The traffic measurement system incorporated with the time synchronization system is used for analyzing characteristics of traffic dynamics. The measurement system adds time-stamp

  18. 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…

  19. Virtual Time

    Microsoft Academic Search

    David Jefferson

    1983-01-01

    Virtual time is a broad, new paradigm for organizing and synchronizing distributed systems, subsuming such heretofore distantly related problems as distributed discrete event simulation and distributed database concurrency control. It is an abstraction of real time in much the same way that virtual memory is an abstraction of real memory, and it reorganizes the concepts of concurrency and synchronization in

  20. 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 ...

  1. Geological Time

    NSDL National Science Digital Library

    "Why do engineers need to know about geologic time?" That question is answered in this resource from the University of Saskatchewan's Department of Civil and Geological Engineering. Provided here is a discussion of the concepts of geological time; relative dating methods, such as correlation; and absolute dating methods, such as radiometric methods. Diagrams and charts are included to demonstrate these complex concepts.

  2. Quantum Time

    E-print Network

    Vittorio Giovannetti; Seth Lloyd; Lorenzo Maccone

    2015-06-04

    We give a consistent quantum description of time, based on Page and Wootters' conditional probabilities mechanism, that overcomes the criticisms that were raised against similar previous proposals. In particular we show how the model allows to reproduce the correct statistics of sequential measurements performed on a system at different times.

  3. Managing Time.

    ERIC Educational Resources Information Center

    Murphy, Linda; Della Corte, Suzanne

    1991-01-01

    This newsletter issue discusses time management techniques for parents of special needs children. Techniques include changing one's attitudes about perfection, prioritizing tasks, having a back-up plan, learning to say "no," asking for help, keeping things simple, hiring others, using waiting time wisely, and doing two things at once. Household…

  4. Screen Time

    NSDL National Science Digital Library

    OMSI

    2007-01-01

    This game asks you a series of questions about how much time you spend in front of a screen, not being active. It begins by pointing out that since we spend a lot of time in front of computer screens at work or school, additional time at home can really affect how healthy we are. It asks how much time you spend watching TV, playing computer games, and using the computer each day. It then adds up the total amount of screen time you spend every day, and calculates how many hours you spend a year in front of a screen. It also tells you if that's a healthy amount, and suggests ways to stay active while in front of screens.

  5. Time Clocks

    NSDL National Science Digital Library

    Stephen Greb

    This exercise can be used to demonstrate changes in the Earth through time, and the length of time it took for those changes to take place. A list of Important Dates in Earth History is provided that contains the dates of the events shown on a time clock. The teacher can pick events from the list of key events and calculate (or have students calculate) the time for the key events they wish to use. A page-size image of the clock can be printed and turned into an overhead transparency. To better demonstrate the changes since the beginning of the Paleozoic Era, the same exercise could be done the second day of class, using only the last 570 million years of time.

  6. Characteristics of hydrogen–hydrocarbon composite fuel turbulent jet flames

    Microsoft Academic Search

    Ahsan R. Choudhuri; S. R. Gollahalli

    2003-01-01

    The characteristics (flame length, pollutant emission, radiative heat loss fraction, and volumetric soot concentration) of hydrogen–hydrocarbon composite fuel turbulent jet diffusion flames are presented. A correlation of flame length with hydrogen concentration in the fuel mixture is shown. The reactivity of fuel mixture increases with the increase of hydrogen concentration, which ultimately shortens the combustion time, and thereby reduces the

  7. Relationship between occupational commitment and ascribed importance of organisational characteristics

    Microsoft Academic Search

    Sheldene Simola

    2011-01-01

    Purpose – This purpose of this paper is to investigate the relationship between dimensions of commitment to the profession of business, and ascribed importance of various organisational characteristics to the first full-time job following graduation. Design\\/methodology\\/approach – Business administration students (n=446) completed surveys on dimensions of their commitment to the profession of business and the importance they ascribed to having

  8. Rail gun performance and plasma characteristics due to wall ablation

    NASA Technical Reports Server (NTRS)

    Ray, P. K.

    1986-01-01

    The experiment of Bauer, et al. (1982) is analyzed by considering wall ablation and viscous drag in the plasma. Plasma characteristics are evaluated through a simple fluid-mechanical analysis considering only wall ablation. By equating the energy dissipated in the plasma with the radiation heat loss, the average properties of the plasma are determined as a function of time.

  9. Short-Term Temporal Stability in Observed Retail Food Characteristics

    ERIC Educational Resources Information Center

    Zenk, Shannon N.; Grigsby-Toussaint, Diana S.; Curry, Susan J.; Berbaum, Michael; Schneider, Linda

    2010-01-01

    Objective: Use of direct observation to characterize neighborhood retail food environments is increasing, but to date most studies have relied on a single observation. If food availability, prices, and quality vary over short time periods, repeated measures may be needed to portray these food characteristics. This study evaluated short-term…

  10. Rhythmic Characteristics of Improvisational Drumming among Preschool Children

    ERIC Educational Resources Information Center

    Whitcomb, Rachel

    2010-01-01

    A call-and-response drumming activity was carried out to determine the rhythmic characteristics of improvised patterns created by preschool children. Specific goals of the study were to: (1) determine the durations, start and stop times, and rhythmic patterns of improvised responses to a simple given call using drums; (2) determine the presence or…

  11. Exploiting Program Microarchitecture Independent Characteristics and Phase Behavior for Reduced

    E-print Network

    Calder, Bradley

    Exploiting Program Microarchitecture Independent Characteristics and Phase Behavior for Reduced of each program in the benchmark suite. However, even with this sampling approach, simulating the full simulation time by finding similarity between benchmarks and program inputs at the level of samples (100M

  12. VANET Topology Characteristics under Realistic Mobility and Channel Models

    E-print Network

    Özkasap, Öznur

    VANET Topology Characteristics under Realistic Mobility and Channel Models Nabeel Akhtar, Oznur--Developing real-time safety and non-safety applica- tions for vehicular ad hoc networks (VANET) requires under the performance of routing protocols and the feasibility of an application over VANET. Using various key metrics

  13. On Chinese College Students' Suicide: Characteristics, Prevention and Crisis Intervention

    ERIC Educational Resources Information Center

    Li, Xiaohong

    2012-01-01

    Nowadays, some characteristics have been detected among Chinese students' suicide including an increasing rate, obvious differences in different grades and genders, relatively integrated suicide methods and a regular time pattern for suicide as well. The principle of selection at registration, dynamic renewal and classified precaution should be…

  14. Spatiotemporal characteristics of calcium dynamics in astrocytes Minchul Kang1

    E-print Network

    Othmer, Hans

    are 10­15 times more numerous than neurons, make up about half of the total brain weight. AstrocytesSpatiotemporal characteristics of calcium dynamics in astrocytes Minchul Kang1 and Hans G. Othmer2 Cai 2+ waves in networks of astrocytes in vivo are well documented, propagation in vivo is much more

  15. Evaluating thermal aging characteristics of electric power transmission lines

    Microsoft Academic Search

    M. M. I. Bhuiyan; P. Musilek; J. Heckenbergerova; D. Koval

    2010-01-01

    Assessment of aging characteristics of conductors and other components of power transmission networks plays an important role in asset management systems. Due to adverse effects of conductor aging caused by annealing, the conductors lose their tensile strength. Although the loss of strength is gradual, it accumulates over time and increases the probability of outages and blackouts. Therefore, the most important

  16. Characteristics of Convergence Learning Experience Using an Educational Documentary Film

    ERIC Educational Resources Information Center

    Shin, Jongho; Cho, Eunbyul

    2015-01-01

    The purpose of the study was to investigate the characteristics of convergence learning experience when learners study integrated learning contents from various academic subjects. Specifically, cognitive and emotional experiences and their changes over time were investigated. Eight undergraduate and graduate students participated in the study.…

  17. Exploring Relationships between School Counselors' Intrapersonal Characteristics and Program Implementation

    ERIC Educational Resources Information Center

    Bazemore, Tracey W.

    2013-01-01

    This study sought to determine if certain personality factors, time management characteristics, or demographics of school counselors were associated with comprehensive program implementation based on the ASCA National Model. Statistical analyses were conducted on the sample and subgroups based on whether ASCA Model use was required. While subgroup…

  18. Degradation Mechanism Of Electron Emission Characteristics In Silicon Field Emitters

    Microsoft Academic Search

    Yoon-Ho Song; Yong-Min Kim; Byung Sung O; Jin Ho Lee; Kyoung Ik Cho; Hyung Joun Yoo

    1997-01-01

    Abstiract - Degradation of electron emission characteristics in silicon field emitters and its mechanism have been studied. The silicon field emitters with a triode type were fabricated by using a chemical-mechanical-polishing process. There exists a critical biasing time, t,, at which the anode current starts to be degraded predominantly. The t, is shortened as the anode current increases. Also, the

  19. Microbenchmarkbased Extraction of Local and Global Disk Characteristics

    E-print Network

    Arpaci-Dusseau, Remzi

    Leakey Sustained innovation in the hard­drive industry has spurred incredible advances in disk technology Obtaining timely and accurate information about the low­level characteristics of disk drives presents, and capacity is growing at nearly the same rate. The disk drive industry moves quickly as well; a new drive

  20. Microbenchmark-based Extraction of Local and Global Disk Characteristics

    E-print Network

    Arpaci-Dusseau, Andrea

    Leakey Sustained innovation in the hard-drive industry has spurred incredible advances in disk technology Obtaining timely and accurate information about the low-level characteristics of disk drives presents, and capacity is growing at nearly the same rate. The disk drive industry moves quickly as well; a new drive

  1. A time domain technique for mechanism extraction

    NASA Technical Reports Server (NTRS)

    Dominek, Allen K.; Peters, Leon, Jr.; Burnside, Walter D.

    1987-01-01

    The properties of scattered fields from a structure can be better evaluated from the characteristics of the individual scatterers. Decomposition techniques can be classified either as a matrix or an integral formulation. With either formulation, aspect pattern of frequency information of a scattering center can be obtained. Emphasis is placed on an integral (time domain) isolation extraction technique to obtain the frequency characteristics of scattering mechanisms. This technique has its origins in the time domain interpretation of scattered fields.

  2. Thermal characteristics of the moon.

    NASA Technical Reports Server (NTRS)

    Lucas, J. W.

    1972-01-01

    The papers describe earth-based and in situ surface measurements of the thermal characteristics of lunar-type materials. A geophysical interpretation of the thermal history of the moon is given. Microwave emission from the moon and radar mapping of lunar surface roughness are studied. Lunar thermal aspects from Surveyor data, lunar surface temperatures from Apollo 11 data, the development of an in situ thermal conductivity measurement for the lunar heat flow experiment, and the Apollo 15 lunar heat flow measurement are reviewed. Thermal properties of granulated materials, thermal property measurements on lunar material returned by Apollo 11 and 12 missions, and thermal characteristics of lunar surface roughness are discussed. Individual items are abstracted in this issue.

  3. Unsteady characteristics of inlet vortices

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Gursul, I.

    2012-10-01

    An experimental study of the unsteady characteristics of inlet vortices has been conducted using a high-frame rate digital particle image velocimetry system. The results revealed the formation of a pair of counter-rotating inlet vortices for the no-wind configuration and one single inlet vortex when there was crosswind. In all measurement planes, from near the ground to the inlet, evidence of vortex meandering with quasi-periodicity was found. The vortex meander is dominant in the direction of the crosswind, and its amplitude increases with crosswind velocity. The proper orthogonal decomposition analysis of the instantaneous velocity field suggested that the most energetic mode was a helical displacement wave, corresponding to the first helical mode. Similarities with the meandering of the trailing vortices from wings were noted. The present results also suggest that the unsteady characteristics of the focus of separation formed on the ground might be responsible for the unsteady nature of the inlet vortex.

  4. Electric arc radius and characteristics

    SciTech Connect

    Fang, T.M.

    1980-09-30

    The heat transfer equation of an arc discharge has been solved. The arc is assumed to be a cylinder with negligible axial variation and the dominant heat transfer process is conduction radially inside the column and radiation/convection at the outside edge. The symmetric consideration allows a simple one-dimensional formulation. By taking into account proper variation of the electrical conductivity as function of temperature, the heat balance equation has been solved analytically. The radius of the arc and its current-field characteristics have also been obtained. The conventional results that E approx. I/sup 0/ /sup 5385/ and R approx. I/sup 0/ /sup 7693/ with E being the applied field, I the current, and R the radius of the cylindrical arc, have been proved to be simply limiting cases of our more general characteristics. The results can be applied quite widely including, among others, the neutral beam injection project in nuclear fusion and MHD energy conversion.

  5. Study of characteristics of single-frequency GaAs/AlGaAs semiconductor lasers

    SciTech Connect

    Kurnosov, V D; Kurnosov, K V; Chernov, Roman V [M.F. Stel'makh Polyus Research and Development Institute, Moscow (Russian Federation)

    2002-04-30

    The characteristics of single-frequency lasers are investigated experimentally and theoretically. It is shown that the model of spectral hole burning with a varying interband relaxation time adequately describes the spectral and modulation characteristics of the laser (taking into account the transport of carriers). The time of carrier capture in a quantum well is 4 ps and the time of their escape is 80 ps. (lasers)

  6. On Time

    NSDL National Science Digital Library

    This online exhibit from a prominent American museum explores the character of time -- its impact on our daily lives and its ability to shape and reform human consciousness. The site is from the National Museum of American History and concentrates on how humans have measured time from 1700 to the present. The exhibit presents text and images describing the history of keeping time from the century immediately preceding the industrial revolution -- when sundials were still in use -- to our present age of digital access and a global village that never sleeps.

  7. Diurnal and seasonal characteristics of Schumann resonance

    NASA Astrophysics Data System (ADS)

    Rawat, Rahul; Singh, Anand Kumar; Pathan, B. M.; Sinha, Ashwini Kumar; Jeeva, K.; Labde, Sachin; Patil, A. G.

    2012-07-01

    Schumann resonances (SR) are lightening generated global electromagnetic modes in extremely low frequency (ELF) range operating in the Earth-ionosphere cavity. The 1st harmonic is at nearly 7.8 Hz and subsequent harmonics are separated by approximately 6 Hz. In this paper an attempt has been made to study the characteristics of SR using ground magnetic data from searchcoil magnetometers operating at a low latitude station Shillong (geographic co-ordinate lat 25.92 N, long 91.88 E) and a sub-auroral Indian Antarctic station Maitri (geographic co-ordinate lat 70.75 S, long 11.75 E). The universal time (UT) diurnal patterns of amplitudes of different harmonics show the dominance of thunderstorm activities in three major sectors viz. south-east Asia, Africa and South America, whereas the frequency variation pattern suggests the tidal influence. The seasonal variation of SR amplitude shows increase during local summer at Shillong as well as Maitri. Amplitudes as well as frequency exhibit distinct seasonal characteristics at both the stations, there by exhibiting the local influence on global SR modes. noindent

  8. Analysis of the characteristics of competitive badminton

    PubMed Central

    Cabello, M; Gonzalez-Badillo, J

    2003-01-01

    Objective: To describe the characteristics of badminton in order to determine the energy requirements, temporal structure, and movements in the game that indicate performance level. To use the findings to plan training with greater precision. Methods: Eleven badminton players (mean (SD) age 21.8 (3.26) years) with international experience from four different countries (France, Italy, Spain, and Portugal) were studied. Two of the Spanish players were monitored in several matches, giving a total of 14 samples, all during the 1999 Spanish International Tournament. Blood lactate concentration was measured with a reflective photometer. Maximum and average heart rates were recorded with a heart rate monitor. Temporal structure and actions during the matches were determined from video recordings. All variables were measured during and after the game and later analysed using a descriptive study. Results: The results confirmed the high demands of the sport, with a maximum heart rate of 190.5 beats/min and an average of 173.5 beats/min during matches over 28 minutes long and performance intervals of 6.4 seconds and rest time of 12.9 seconds between exchanges. Conclusions: The results suggest that badminton is characterised by repetitive efforts of alactic nature and great intensity which are continuously performed throughout the match. An awareness of these characteristics, together with data on the correlations between certain actions such as unforced errors and winning shots and the final result of the match, will aid in more appropriate planning and monitoring of specific training. PMID:12547746

  9. Pulsed plasma thruster ignitor plug ignition characteristics

    NASA Technical Reports Server (NTRS)

    Brady, M. E.; Aston, G.

    1982-01-01

    The operating characteristics of the semiconductor spark gap ignitor plug used to initiate the discharge in a pulsed plasma thruster are investigated. Current and voltage waveform measurements for the ignitor plug alone, and for the plug mounted in the thruster cathode indicate an average dynamic impedance of 0.2 ohms for a wide range of operating conditions, and a trigger circuit energy transfer efficiency to the plug on the order of 25%. Two modes of trigger ignition are found which are related to the rise time of the applied voltage pulse. Analysis of plasma characteristics reveals plug erosion to occur primarily in the semiconductor and anode regions, by mechanisms including plug metal embrittlement, plasma sputtering and vaporization caused by the discharge current pulse. Measurements also indicate a plume velocity on the order of 1580,000 cm/sec which increases with trigger circuit stored energy. The results establish levels of performance for future applications of semiconductor spark gap ignitor plugs in plasma devices.

  10. Characteristics of the Texas Aged. 

    E-print Network

    Skrabanek, R. L.; Dickerson, B. E. (Ben Edward); Upham, W. Kennedy (William Kennedy)

    1966-01-01

    for older people will be expanded as will retirement homes for the aged. Means of combating loneliness in the lives of aged persons will receive close study. Much thought will be directed toward keeping larger numbers of older people occupationally... With current retirement policies in effect, this mennt increasing numbers of Texans will have 35 year! nr more of "doing nothing." T HIS PUBLICATION ANALYZES some significant demo- graphic characteristics of the aged population of Texas...

  11. Spontaneous imbibition characteristics of diatomite

    Microsoft Academic Search

    S Akin; J. M Schembre; S. K Bhat; A. R Kovscek

    2000-01-01

    A systematic investigation of fluid flow characteristics within diatomite (a high porosity, low permeability, siliceous rock) is reported. Using an X-ray computerized tomography (CT) scanner, and a novel, CT-compatible imbibition cell, we study spontaneous cocurrent water imbibition into diatomite samples. Air–water and oil–water systems are used and the initial water saturation is variable. Mercury porosimetry and a scanning electron microscope

  12. Descendant invariants and characteristic numbers

    Microsoft Academic Search

    Thomas Benjamin Graber; Joachim Kock; Rahul Pandharipande

    2002-01-01

    On a stack of stable maps, the psi classes are modified by subtracting\\u000acertain boundary divisors. These modified psi classes are compatible with\\u000aforgetful morphisms, and are well-suited to enumerative geometry: tangency\\u000aconditions allow simple expressions in terms of modified psi classes.\\u000aTopological recursion relations are established among their top products in\\u000agenus zero, yielding effective recursions for characteristic numbers

  13. Personality characteristics and sleep variables.

    PubMed

    Nakazawa, Y; Kotorii, M; Arikawa, K; Horikawa, S; Hasuzawa, H

    1975-01-01

    In a sleep study of 14 normal healthy adults an investigation was made of sleep measurements of a baseline record for its eventual relationship to the percentage of increase of REM percentage of the 1st recovery night following partial differential REM deprivation (PDRD), as well as to personality characteristics. The percentage of change in NREM sleep of the 1st recovery night was compared with the baseline record andthen compared with corresponding values of REM sleep. The results are summarized as follows. No significant correlation exists between the percentage of increase in the REM percentage of the 1st recovery night and sleep measures of the baseline record. An investigation of the relationship between sleep measures of the baseline record and personality characteristics revealed that stage SWS(%) was significantly greater in the introvert than in the extrovert, in the neurotic than in the non-neurotic, and in the nervous than in the optimistic. Comparison of the changes in NREM and REM sleep percentages of the 1st recovery night with the baseline record was made between paired personality characteristics. A significantly high percentage of increase in REM percentage was almost always associated with a significantly high percentage of decrease in stage 2 percentage. From these results it was inferred that an increase in REM percentage occurs at the expense of stage 2 percentage. PMID:170175

  14. Creative Time

    NSDL National Science Digital Library

    2012-08-31

    Creative Time curates, funds, and organizes public art projects, so their website is a reference of the form dating back to 1975. You can browse by program name, date or artist's name (the most common of these being "multiple artists.") Creative Time's roster also includes familiar names such as Marina Abramovic, Doug Aitken, Laurie Anderson, David Byrne, Paul Chan, Jenny Holzer, Gary Hume, Vik Muniz, Takashi Murakami, Shirin Neshat, Steve Powers, and Cai Guo-Qiang. For example, Creative Time worked with Cai Guo-Qiang to present Light Cycle, in 2003, to celebrate the 150th anniversary of New York City's Central Park; in 2008 David Byrne's Playing the Building transformed the Battery Maritime Building in Lower Manhattan into a massive sound sculpture that visitors could play using a keyboard; and in summer 2012 Creative Time and multiple artists hosted a sandcastle competition at Far Rockaway, possibly the start of a new New York summer tradition.

  15. Time Management

    NSDL National Science Digital Library

    MindTools (MindTools)

    2012-01-20

    This section of Mind Tools teaches you time management skills. These are the simple, practical techniques that have helped the leading people in business, sport and public service reach the pinnacles of their careers.

  16. Time outs

    MedlinePLUS

    ... Time-out technique for discipline. Children's Health Network web site. http://www.childrenshealthnetwork.org/CRS/CRS/pa_ ... a break from negative behavior. Massachusetts Medical Society web site. http://www.massmed.org/patient-care/health- ...

  17. Characteristics of magnetospheric radio noise spectra

    NASA Technical Reports Server (NTRS)

    Herman, J. R.

    1976-01-01

    Magnetospheric radio noise spectra (30 kHz to 10 MHz) taken by IMP-6 and RAE-2 exhibit time varying characteristics which are related to spacecraft position and magnetospheric processes. In the midfrequency range (100-1000 kHz) intense noise peaks rise a factor of 100 or more above background; 80% of the peak frequencies are within the band 125 kHz to 600 kHz, and the peak occurs most often (18% of the time) at 280 kHz. Bandwidths of the peaks range from about 100 kHz to more than 500 kHz; most often the lower cutoff is at about 100 kHz and the upper at 380 kHz for a total bandwidth of 280 kHz. This intense mid-frequency noise was detected at radial distances from 1.3 Re to 60 Re on all sides of the earth (i.e., all local times) during magnetically quiet as well as disturbed periods. Maximum occurrence of the mid-frequency noise is in the evening to midnight hours where splash-type energetic particle precipitation takes place.

  18. Electric current characteristic of anodic bonding

    NASA Astrophysics Data System (ADS)

    He, Jun; Yang, Fang; Wang, Wei; Zhang, Li; Huang, Xian; Zhang, Dacheng

    2015-06-01

    In this paper, a novel current–time model of anodic bonding is proposed and verified experimentally in order to investigate underlying mechanisms of anodic bonding and to achieve real-time monitoring of bonding procedure. The proposed model provides a thorough explanation for the electric current characteristic of anodic bonding. More significantly, it explains two issues which other models cannot explain. One is the sharp rise in current when a voltage is initially applied during anodic bonding. The other is the unexpected large width of depletion layers. In addition, enlargement of the intimately contacted area during anodic bonding can be obtained from the proposed model, which can be utilized to monitor the bonding process. To verify the proposed model, Borofloat33 glass and silicon wafers were adopted in bonding experiments in SUSS SB6 with five different bonding conditions (350?°C 1200?V 370?°C 1200?V 380?°C 1200?V 380?°C 1000?V and 380?°C 1400?V). The results indicate that the observed current data highly coincide with the proposed current-time model. For widths of depletion layers, depth profiling using secondary ion mass spectrometry demonstrates that the calculated values by the model are basically consistent with the experimental values as well.

  19. INITIAL CHARACTERISTICS OF KEPLER SHORT CADENCE DATA

    SciTech Connect

    Gilliland, Ronald L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Jenkins, Jon M.; Caldwell, Douglas A.; Clarke, Bruce D.; Quintana, Elisa V.; Twicken, Joseph D.; Van Cleve, Jeffrey E. [SETI Institute/NASA Ames Research Center, MS 244-30, Moffett Field, CA 94035 (United States); Borucki, William J.; Bryson, Stephen T.; Dotson, Jessie L.; Haas, Michael R.; Koch, David [NASA Ames Research Center, MS 244-30, Moffett Field, CA 94035 (United States); Hall, Jennifer; Klaus, Todd; McCauliff, Sean [Orbital Sciences Corporation/NASA Ames Research Center, MS 244-30, Moffett Field, CA 94035 (United States)], E-mail: gillil@stsci.edu

    2010-04-20

    The Kepler Mission offers two options for observations-either long cadence (LC) used for the bulk of core mission science, or short cadence (SC) which is used for applications such as asteroseismology of solar-like stars and transit timing measurements of exoplanets where the 1 minute sampling is critical. We discuss the characteristics of SC data obtained in the 33.5 day long Quarter 1 observations with Kepler which completed on 2009 June 15. The truly excellent time series precisions are nearly Poisson limited at 11th magnitude providing per-point measurement errors of 200 parts-per-million per minute. For extremely saturated stars near seventh magnitude precisions of 40 ppm are reached, while for background limited measurements at 17th magnitude precisions of 7 mmag are maintained. We note the presence of two additive artifacts, one that generates regularly spaced peaks in frequency, and one that involves additive offsets in the time domain inversely proportional to stellar brightness. The difference between LC and SC sampling is illustrated for transit observations of TrES-2.

  20. Microbiological characteristics of Pacific shrimp (Pandalus jordani).

    PubMed Central

    Lee, J S; Pfeifer, D K

    1977-01-01

    Microorganisms associated with Pacific shrimp (Pandalus jordani) were isolated and identified. Those on the iced raw shrimp, which yielded an average count of 1.6 x 10(6), were predominantly Moraxella, Pseudomonas, Acinetobacter, Arthrobacter, and Flavobacterium-Cytophaga spp. The blanching and peeling reduced the microbial level to 3.3 x 10(4) and also selectively eliminated Moraxella spp. The microbial flora changed after each processing sequence, and the heat sensitivity and growth characteristics of the representative microbial groups suggested that the presence of Arthrobacter and Acinetobacter spp. in peeled shrimp may indicate inadequate cleaning of raw shrimp or a shorter blanching time. The presence of Moraxella and Flavobacterium-Cytophaga spp. would indicate the degree of secondary contamination, and the presence of Pseudomonas spp. would indicate the shelf-age of the processed shrimp. PMID:869532

  1. Study of hydrodynamic characteristics in tubular photobioreactors.

    PubMed

    Zhang, Qinghua; Wu, Xia; Xue, Shengzhang; Liang, Kehong; Cong, Wei

    2013-02-01

    In this work, the hydrodynamic characteristics in tubular photobioreactors with a series of helical static mixers built-in were numerically investigated using computational fluid dynamics (CFD). The influences of height and screw pitch of the helical static mixer and fluid inlet velocity on the cell trajectories, swirl numbers and energy consumption were examined. In order to verify the actual results for cultivation of microalgae, cultivation experiments of freshwater Chlorella sp. were carried out in photobioreactor with and without helical static mixer built-in at the same time. It was shown that with built-in helical static mixer, the mixing of fluid could be intensified, and the light/dark cycle could also be achieved which is of benefit for the growth of microalgae. The biomass productivity of Chlorella sp. in tubular photobioreactor with helical static mixer built-in was 37.26 % higher than that in the photobioreactor without helical static mixer. PMID:22729676

  2. [Infrared spectrum characteristics of vehicle body paint].

    PubMed

    Chen, Tao; Long, Xian-Jun; Wei, Lang; Gong, Biao; Li, Chun-Ming

    2012-07-01

    Two hundred eighty seven samples of vehicle paint were collected, and 940 spectra were obtained by Fourier transform infrared micro spectrometer. The spectral features of varnish, finish layer, and coated layers of different models and different color were analyzed, and the spectra similarities were compared. The results show that the varnish similarity on the same models with different color is 99.5%, and some similar model with the same manufacturer had high similarity. The finish spectra have remarkable differences with different model and different color, and the similarity degree is under 70%. The coated layer similarity varies between 83.33% and 96.91% among the common lacquer putty, and it ranges between 70.12% and 96.44% among the water-based lacquer putty. The metal components of paint will influence the spectrum characteristics. The spectra of the vehicle paint will change with the usage time. PMID:23016329

  3. Modeling waterborne passenger transportation user characteristics

    SciTech Connect

    Berkowitz, C.M.

    1985-01-01

    This dissertation examines potential new directions for the utilization of the waterborne passenger transportation mode. The research provides the analytical and managerial tools that will encourage and support the future development of this mode. Special emphasis is given to the analysis of waterborne transportation demand characteristics and mode potential, using a logit based waterborne passenger transportation demand model. The model was calibrated using data collected in Staten Island, New York. The data were collected utilizing a mailback questionnaire designed exclusively for the worktrip. Utilizing the results of the calibrated logit model, tests were preformed to determine the sensitivity of demand to changes in travel time, trip cost, and comfort and convenience. Based on the relationships developed from the sensitivity evaluation, a profitability analysis was conducted for the implementation of a high-speed ferry service replacing the existing Staten Island Ferry System. The high-speed service's effect on total ferry users and the impact of different fare levels were also examined.

  4. Occurrences of palindromes in characteristic Sturmian words

    E-print Network

    Glen, Amy

    2006-01-01

    This paper is concerned with palindromes occurring in characteristic Sturmian words $c_\\alpha$ of slope $\\alpha$, where $\\alpha \\in (0,1)$ is an irrational. As $c_\\alpha$ is a uniformly recurrent infinite word, any (palindromic) factor of $c_\\alpha$ occurs infinitely many times in $c_\\alpha$ with bounded gaps. Our aim is to completely describe where palindromes occur in $c_\\alpha$. In particular, given any palindromic factor $u$ of $c_\\alpha$, we shall establish a decomposition of $c_\\alpha$ with respect to the occurrences of $u$. Such a decomposition shows precisely where $u$ occurs in $c_\\alpha$, and this is directly related to the continued fraction expansion of $\\alpha$.

  5. Maternal Characteristics Predicting Young Girls’ Disruptive Behavior

    PubMed Central

    van der Molen, Elsa; Hipwell, Alison E.; Vermeiren, Robert; Loeber, Rolf

    2011-01-01

    Little is known about the relative predictive utility of maternal characteristics and parenting skills on the development of girls’ disruptive behavior. The current study used five waves of parent and child-report data from the ongoing Pittsburgh Girls Study to examine these relationships in a sample of 1,942 girls from age 7 to 12 years. Multivariate Generalized Estimating Equation (GEE) analyses indicated that European American race, mother’s prenatal nicotine use, maternal depression, maternal conduct problems prior to age 15, and low maternal warmth explained unique variance. Maladaptive parenting partly mediated the effects of maternal depression and maternal conduct problems. Both current and early maternal risk factors have an impact on young girls’ disruptive behavior, providing support for the timing and focus of the prevention of girls’ disruptive behavior. PMID:21391016

  6. Rehabilitation time before disability pension

    PubMed Central

    2012-01-01

    Background The decision to grant a disability pension is usually the end of a long process of medical examinations, treatment and rehabilitation attempts. This study investigates to what extent the time spent on rehabilitation time prior to disability pension is associated with characteristics of the individual or the local employment and welfare office, measured as municipality variance. Methods A study of 2,533 40 to 42 year olds who received disability pension over a period of 18 years. The logarithm of the rehabilitation time before granting a disability pension was analysed with multilevel regression. Results The rehabilitation time before a disability pension was granted ranged from 30 to 5,508 days. Baseline health characteristics were only moderately associated with rehabilitation time. Younger people and people with unemployment periods had longer rehabilitation time before a disability pension was granted. There were only minor differences in rehabilitation time between men and women and between different levels of education. Approximately 2% of the total variance in rehabilitation time could be attributed to the municipality of residence. Conclusions There is a higher threshold for granting a disability pension to younger persons and those who are expecting periods of unemployment, which is reflected in the extended rehabilitation requirements for these groups. The longer rehabilitation period for persons with psychiatric disorders might reflect a lack of common knowledge on the working capacity of and the fitted rehabilitation programs for people with psychiatric disorders. PMID:23110397

  7. Timing & Time Code Reference REFERENCE GUIDE

    E-print Network

    Berns, Hans-Gerd

    ...........................................................................................................1 Universal Time (UT0....................................................................................................................2 Coordinated Universal TimeTiming & Time Code Reference REFERENCE GUIDE #12;i Time Scales of Measurement Introduction

  8. Direct measurements of neutral wave characteristics in the thermosphere

    NASA Technical Reports Server (NTRS)

    Potter, W. E.; Kayser, D. C.; Mauersberger, K.

    1976-01-01

    The elliptical and circular phases of the Atmosphere Explorer-C satellite have provided the basis for a study of the neutral wave characteristics in the thermosphere using data collected by the open source mass spectrometer used to measure both reactive (O,N) and nonreactive (O2, N2, He, Ar) constituents. The phase relationships between the constituents are discussed and the results of a wave occurrence and amplitude survey covering 338 despun orbits in which the local time and latitude characteristics of the waves are presented are discussed. Conclusions based on this survey are tested in a study of waves measured at high latitudes during a geomagnetic storm.

  9. Time 100

    NSDL National Science Digital Library

    1998-01-01

    This Time Warner Pathfinder (discussed in the November 11, 1994 Scout Report) Time Magazine site, released to coincide with a Time cover story of the same title, is the first in what is to be a five part site that will eventually cover 100 of the 20th Century's most influential people. At present the site contains profiles of 20 of the century's most influential "leaders & revolutionaries," including Margaret Sanger, Vladimir Lenin, Winston Churchill, Dr. Martin Luther King, Jr., Ayatolla Ruholla Khomeini, and the anonymous Chinese protester who blocked the tank in the Tienanmen Square protest in 1989. Stories about the personalities by such authors as Gloria Steinem, Arthur Schlesinger, Jr., Salman Rushdie, Elie Wiesel, and Stanley Karnow, among others, highlight the site. There is also a timeline of each personality, as well as a timeline of the century. For the personalities who were covered by Time, an original in-depth story from the Time archives is available. Forthcoming throughout 1998 and 1999 are sections on "entertainers & artists, builders & titans, scientists & thinkers, and heroes and inspirations." The site is also available in a Shockwave Flash version.

  10. accelerates Slow time Fast time

    E-print Network

    of the Earth, but it still remains finite. 4 #12;"INFINITE" speed up! (no limit) infinite gravitational pull on time). Clocks higher in a gravitational well tick faster. 2 #12;Earth GPS general positioning system P

  11. Determination of internal quantum efficiency of a photodetector through its voltage-current characteristics

    Microsoft Academic Search

    Aleksey Mikryukov; Alexander Kovalev; Anatoly A. Liberman; Sergey Moskaluk

    2011-01-01

    This paper, for the first time, suggests a method of determining internal quantum efficiency of an opaque p+nn+ photodetector and some of its characteristics based on a comparison between experimental measurements of photodetector's voltage-current characteristics and characteristics calculated with PC1D. For our research we chose a silicon photodetector Hamamatsu 1337. It was necessary that reflection coefficient of the front surface

  12. Acoustic characteristics of English fricatives

    E-print Network

    Jongman, Allard; Wayland, Ratree; Wong, Serena

    2000-09-01

    - search on relative amplitude has focused on its role in per- ception ~e.g., Stevens, 1985; Hedrick and Ohde, 1993; He- drick, 1997; Hedrick and Carney, 1997!. For example, in order to create appropriate synthetic stimuli, Hedrick and Ohde ~1993! measured...Acoustic characteristics of English fricatives sa G 30 J si h p ec eq c p re ge athe identification of acoustic cues which uniquely character- ize particular ~classes of! speech sounds is a serious chal- lenge. A major obstacle in this endeavor...

  13. Pheochromocytoma and paraganglioma: imaging characteristics

    PubMed Central

    Jagannathan, Jyothi P.; Krajewski, Katherine; O’Regan, Kevin; Zukotynski, Katherine; Kulke, Matthew; Ramaiya, Nikhil H.

    2012-01-01

    Abstract The accurate diagnosis of adult pheochromocytoma and paraganglioma necessitates a multidisciplinary approach that includes clinical history, biochemical testing, and multimodality imaging such as computed tomography, magnetic resonance imaging, and nuclear medicine studies. This review illustrates the different imaging characteristics of primary adult pheochromocytomas as well as both sympathetic and parasympathetic paragangliomas. The review also describes known genetic associations and shows common metastatic patterns. Knowledge of the diverse appearance of pheochromocytomas and paragangliomas can result in early initial diagnosis or detection of disease recurrence thereby affecting patient management and prognosis. PMID:22571874

  14. [Molecular biological characteristics of cancer].

    PubMed

    Kushlinski?, N E; Nemtsova, M V

    2014-01-01

    The review presents the main and additional features that distinguish tumor cells from normal tissue cells. They include sustained proliferative signaling, evasion from growth suppressors, resisting cell death, enabling replicative immortality, angiogenesis induction, and invasion and metastasis activation. Basis for the formation of these features is provided by tumor genome instability. Tumors are complex tissues that consist of different cell types interacting with each other as well as with normal cells. An important characteristic of tumor cells is the ability to interact with the tumor microenvironment and the formation of tumor stroma. PMID:25055553

  15. Solar image characteristics of concentrators

    SciTech Connect

    Phillips, P.; Bayazitoglu, Y.

    1981-01-01

    A model is developed to study solar image characteristics of solar concentrators. The reflecting and absorbing surfaces of the concentrator are represented by finite elements. Each element is considered to have nine nodes. A piecewise ray tracing method is studied such that, instead of representing the reflected beam from an element with one ray, nine rays are used. At each node the solar beam is assumed to be reflected with the same solid angle of the solar disk, which provides a diverging reflected image of the element. 5 refs.

  16. Gaultheria: Phytochemical and pharmacological characteristics.

    PubMed

    Liu, Wei-Rui; Qiao, Wen-Lin; Liu, Zi-Zhen; Wang, Xiao-Hong; Jiang, Rui; Li, Shu-Yi; Shi, Ren-Bing; She, Gai-Mei

    2013-01-01

    The genus Gaultheria, comprised of approximately 134 species, is mostly used in ethnic drugs to cure rheumatism and relieve pain. Phytochemical investigations of the genus Gaultheria have revealed the presence of methyl salicylate derivatives, C?-C? constituents, organic acids, terpenoids, steroids, and other compounds. Methyl salicylate glycoside is considered as a characteristic ingredient in this genus, whose anti-rheumatic effects may have a new mechanism of action. In this review, comprehensive information on the phytochemistry, volatile components and the pharmacology of the genus Gaultheria is provided to explore its potential and advance research. PMID:24084015

  17. [Ultrafiltration characteristics of immunobiological preparations].

    PubMed

    Perepechkina, N P; Mats, A N; Köhler, H U; Schulze, H A; Gur'ev, I S

    1986-06-01

    The removal of ammonium sulfate from the bulk product of fermented antitoxic serum by continuous diafiltration was not accompanied by changes in the stability of the solution. To concentrate immunoglobulin, eluted from DEAE cellulose, by diafiltration, the stabilization of the solution by adding sodium chloride at high concentration was necessary. The use of membranes purchased from different manufacturers and having similar selectivity characteristics permitted obtaining transfer factor preparations somewhat differing in their biological activity. The process of ultrafiltration, carried out in the atmosphere of compressed carbon dioxide, made it possible to obtain such preparations from donor blood plasma. PMID:3751399

  18. The characteristics of successful wells

    Microsoft Academic Search

    Scattolini

    1989-01-01

    As with any computer work, database building can be tedious and time consuming. The time spent aside, the way such a database is used is most important. for interpretation work, the effort investigated can be a valuable addition to understanding the earth, its hydrocarbon resources and its drillable prospects. Using an interactive relational database program and files with discovery-well information,

  19. Hardware implementation of associative memory characteristics with analogue-type resistive-switching device.

    PubMed

    Moon, Kibong; Park, Sangsu; Jang, Junwoo; Lee, Daeseok; Woo, Jiyong; Cha, Euijun; Lee, Sangheon; Park, Jaesung; Song, Jeonghwan; Koo, Yunmo; Hwang, Hyunsang

    2014-12-12

    We have investigated the analogue memory characteristics of an oxide-based resistive-switching device under an electrical pulse to mimic biological spike-timing-dependent plasticity synapse characteristics. As a synaptic device, a TiN/Pr0.7Ca0.3MnO3-based resistive-switching device exhibiting excellent analogue memory characteristics was used to control the synaptic weight by applying various pulse amplitudes and cycles. Furthermore, potentiation and depression characteristics with the same spikes can be achieved by applying negative and positive pulses, respectively. By adopting complementary metal-oxide-semiconductor devices as neurons and TiN/PCMO devices as synapses, we implemented neuromorphic hardware that mimics associative memory characteristics in real time for the first time. Owing to their excellent scalability, resistive-switching devices, shows promise for future high-density neuromorphic applications. PMID:25414164

  20. Hardware implementation of associative memory characteristics with analogue-type resistive-switching device

    NASA Astrophysics Data System (ADS)

    Moon, Kibong; Park, Sangsu; Jang, Junwoo; Lee, Daeseok; Woo, Jiyong; Cha, Euijun; Lee, Sangheon; Park, Jaesung; Song, Jeonghwan; Koo, Yunmo; Hwang, Hyunsang

    2014-12-01

    We have investigated the analogue memory characteristics of an oxide-based resistive-switching device under an electrical pulse to mimic biological spike-timing-dependent plasticity synapse characteristics. As a synaptic device, a TiN/Pr0.7Ca0.3MnO3-based resistive-switching device exhibiting excellent analogue memory characteristics was used to control the synaptic weight by applying various pulse amplitudes and cycles. Furthermore, potentiation and depression characteristics with the same spikes can be achieved by applying negative and positive pulses, respectively. By adopting complementary metal-oxide-semiconductor devices as neurons and TiN/PCMO devices as synapses, we implemented neuromorphic hardware that mimics associative memory characteristics in real time for the first time. Owing to their excellent scalability, resistive-switching devices, shows promise for future high-density neuromorphic applications.

  1. Fundamental Gridding Related Dispersion Effects in Multiresolution Time Domain Schemes

    E-print Network

    Fundamental Gridding Related Dispersion Effects in Multiresolution Time Domain Schemes Costas D node arrangement on the dispersion characteristics of the Multiresolution Time Domain technique is investigated in this paper. It is first noted that by multiresolution analysis principles, introducing one

  2. Relationship between Time Perception and Kirton's Adaption-Innovation Inventory.

    ERIC Educational Resources Information Center

    Walling, M.; And Others

    Time production is an experimental paradigm that compares the accuracy with which a subject can produce a specified time interval relative to actual clock time. Higgins (1987) found that subjects perceived the passage of time as faster or slower, compared to actual time, as an interrelation of personality characteristics and experimental…

  3. Geologic Time

    NSDL National Science Digital Library

    Timothy Heaton

    This site contains 24 questions on the topic of geologic time, which covers dating techniques and unconformities. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate feedback.

  4. Deep Time

    NSDL National Science Digital Library

    WPSU

    2010-05-04

    In this video a Penn State professor refers to National Park canyons carved out by water and wind as he explains “deep time” - the notion that the earth is billions of years old; another professor states how the theory of evolution is supported by evidence of an ancient Earth recorded in rocks.

  5. Time out

    MedlinePLUS

    "Time out" is a technique used by parents and teachers in response to undesired behavior in a child. It involves removing the child from the environment and activities in which the inappropriate behavior occurred, and placing the child in a specific ...

  6. Charge Characteristics of Rechargeable Batteries

    NASA Astrophysics Data System (ADS)

    Maheswaranathan, Ponn; Kelly, Cormac

    2014-03-01

    Rechargeable batteries play important role in technologies today and they are critical for the future. They are used in many electronic devices and their capabilities need to keep up with the accelerated pace of technology. Efficient energy capture and storage is necessary for the future rechargeable batteries. Charging and discharging characteristics of three popular commercially available re-chargeable batteries (NiCd, NiMH, and Li Ion) are investigated and compared with regular alkaline batteries. Pasco's 850 interface and their voltage & current sensors are used to monitor the current through and the potential difference across the battery. The discharge current and voltage stayed fairly constant until the end, with a slightly larger drop in voltage than current, which is more pronounced in the alkaline batteries. After 25 charge/discharge cycling there is no appreciable loss of charge capacities in the Li Ion battery. Energy densities, cycle characteristics, and memory effects will also be presented. Sponsored by the South Carolina Governor's school for Science and Mathematics under the Summer Program for Research Interns program.

  7. Hazardous waste landfill leachate characteristics

    SciTech Connect

    Pavelka, C. (Woodward-Clyde Consultants, Maryland Heights, MO (United States)); Loehr, R.C. (Univ. of Texas, Austin, TX (United States). Environmental and Water Resources Engineering Program); Haikola, B. (Remediation Technologies, Inc., Austin, TX (United States))

    1993-01-01

    Leachate data from 18 commercial hazardous waste landfills or cells were evaluated to determine overall leachate characteristics and parameters that may affect leachate generation and characteristics. The landfills studied have a wide range of practices, none of which are necessarily representative of the most current landfill design, operating or closure practice in the United States. The leachate samples were from landfills that represented varying waste types, waste age, geographic locations and climate. The parameters evaluated included chemical properties, co-disposal of hazardous and municipal solid wastes, climatic conditions, and waste age in the landfills. The leachate samples had been analyzed for 62 volatiles, 107 semi-volatiles, 16 metals, 28 pesticides, herbicides and insecticides, and 17 other chemicals. The results indicate that: (a) the organics in the leachate with high concentrations had high solubilities and low octanol-water coefficients, (b) landfills in arid climates produced less leachate than those in temperate and sub-tropical climates, and (c) leachate production appeared to be related to use of a cap or cover.

  8. Female Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time

    E-print Network

    Suzuki, Masatsugu

    Female Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time 1 Amy:56:27.6 Deborah Mc Eligot Deborah Storrings Male Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time 1 Macon Fessenden 20 1 5:42.2 2 0:26.9 1 34:29.7 3:23 1 0:12.8 1 17:41.1 3

  9. Forecasting daily time series using periodic unobserved components time series models

    Microsoft Academic Search

    Siem Jan Koopman; Marius Ooms

    2006-01-01

    We explore a periodic analysis in the context of unobserved components time series models that decompose time series into components of interest such as trend, seasonal and irregular. Periodic time series models allow dynamic characteristics such as auto- covariances to depend on the period of the year, month, week or day. In the standard multivariate approach one can interpret periodic

  10. Estimation of Characteristic Period for Energy Based Seismic Design

    SciTech Connect

    Hancloglu, Baykal; Polat, Zekeriya; Kircil, Murat Serdar [Yildiz Technical University, Department of Civil Engineering, Besiktass 34349 Istanbul (Turkey)

    2008-07-08

    Estimation of input energy using approximate methods has been always a considerable research topic of energy based seismic design. Therefore several approaches have been proposed by many researchers to estimate the energy input to SDOF systems in the last decades. The characteristic period is the key parameter of most of these approaches and it is defined as the period at which the peak value of the input energy occurs. In this study an equation is proposed for estimating the characteristic period considering an extensive earthquake ground motion database which includes a total of 268 far-field records, two horizontal components from 134 recording stations located on both soft and firm soil sites. For this purpose statistical regression analyses are performed to develop an equation in terms of a number of structural parameters, and it is found that the developed equation yields satisfactory results comparing the characteristic periods calculated from time history analyses of SDOF systems.

  11. Measuring the real-time operating system performance

    Microsoft Academic Search

    Krzysztof M. Sacha

    1995-01-01

    Tests for measuring the real time operating system performance belong to the software technology. They give quantitative measures for the most important characteristics and allow the implementer to compare the efficiency of various operating systems. The paper presents a set of simple tests for measuring the real time operating system characteristics. The tests require no specialized hardware, and are based

  12. Pedotransfer functions: bridging the gap between available basic soil data and missing soil hydraulic characteristics

    Microsoft Academic Search

    J. H. M. Wösten; Ya. A. Pachepsky; W. J. Rawls

    2001-01-01

    Water retention and hydraulic conductivity are crucial input parameters in any modelling study on water flow and solute transport in soils. Due to inherent temporal and spatial variability in these hydraulic characteristics, large numbers of samples are required to properly characterise areas of land. Hydraulic characteristics can be obtained from direct laboratory and field measurements. However, these measurements are time

  13. Food Characteristics of Recipes Using Stevia Sweetner - A Proposed Herbal Sugar Substitute

    Microsoft Academic Search

    L. Kerzicnik; N. Stendell; M. McMuny; D. Hagan

    1999-01-01

    Stevia rebaudiana is a perennial herb with claimed medicinal and culinary characteristics. It is approximately 300 times sweeter than sucrose (table sugar). Thirty-two volunteer participants evaluated three different food products for the following sensory characteristics:.tenderness, aroma, color, grain size or consistency, and overall appearance. Standard food testing evaluation methods were used, including ink prints and standing height measurements. Data was

  14. The Measurement of Carcass Characteristics of Goats Using the Ultrasound Method

    Microsoft Academic Search

    G. Corral de Mesta; Paul A. Will; J. M. Gonzalez

    2004-01-01

    The objective of this study was to determine if ante mortem carcass characteristics measured via the ultrasound method in live goats is associated with carcass characteristic measured postmortem. Forty crossbred Spanish goats were evaluated at five different time periods for a total of 80 days. Ante mortem measurements of fat thickness (FTU), longissimus muscle area (LMAU), longissimus muscle width (LMWU),

  15. General-Purpose Characteristic Basis Finite Element Method for Multi-Scale Electrostatic and Electromagnetic Problems

    Microsoft Academic Search

    Ozlem Ozgun; Raj Mittra; Mustafa Kuzuoglu

    2010-01-01

    This article presents a noniterative and parallel finite element technique that is tailored for a wide class of electromagnetic boundary problems, covering both quasi-static and time-harmonic regimes. This approach, called the characteristic basis finite element method, combines the domain decomposition technique with the use of characteristic basis functions that are generated by employing a finite number of point charges or

  16. Analysis of rainfall characteristics of the Madden–Julian oscillation using TRMM satellite data

    Microsoft Academic Search

    Juntaro Morita; Yukari N. Takayabu; Shoichi Shige; Yasumasa Kodama

    2006-01-01

    Rainfall characteristics of the Madden–Julian oscillation (MJO) are analyzed primarily using tropical rainfall measuring mission (TRMM) precipitation radar (PR), TRMM microwave imager (TMI) and lighting imaging sensor (LIS) data. Latent heating structure is also examined using latent heating data estimated with the spectral latent heating (SLH) algorithm.The zonal structure, time evolution, and characteristic stages of the MJO precipitation system are

  17. Electrochemical models for the discharge characteristics of the nickel cadmium cell

    NASA Technical Reports Server (NTRS)

    Spritzer, M. S.

    1981-01-01

    The potential time characteristics of a preconditioned fully charged cell discharge at constant current was studied. Electrochemical principles applied to the sealed nickel cadmium cell and its behavior and to predict operating characteristics were described. A thermodynamic approach to arrive at several related but different equations and its discharge are reported.

  18. Statistical characteristics of pedestrians' motion and effects on teletraffic of mobile communication networks

    Microsoft Academic Search

    Yuka Nagai; Takehiko Kobayashi

    2005-01-01

    Motion of mobile terminals greatly affects traffic characteristics (cell dwell time, handoff rates, channel occupancy lime of each base station, etc.) in mobile communication networks. Motion of vehicles was previously measured and characterized using the Global Positioning System, and its effects on traffic characteristics were examined. In this study, the authors measured pedestrian motion using an autonomous navigation system, analyzed

  19. Calculation of angular trajectory characteristics using inclinations of electron-density isosurfaces

    Microsoft Academic Search

    T. S. Kerblai; O. V. Chernyshev

    1978-01-01

    The paper presents a method for calculating the angular characteristics of radio-wave trajectories in the ionosphere from inclinations of electron-density isosurfaces. The method gives the angular characteristics of trajectories of different orientation for different periods of time.

  20. Parents' Developmental Expectations and Child Characteristics: Longitudinal Study of Children with Developmental Delays and Their Families.

    ERIC Educational Resources Information Center

    Clare, Lindsay; Garnier, Helen; Gallimore, Ronald

    1998-01-01

    This study examined the relationship between child characteristics and parents' developmental expectations for their children with developmental delays at ages 3, 7, and 11. Overall, parents' developmental expectations were associated with child characteristics, were moderately stable over time, and tended to decline as children matured.…