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1

Stability characteristics of a supersonic boundary layer and their relation to the position of the laminar-turbulent transition point  

NASA Technical Reports Server (NTRS)

By comparing the calculated results with experimental data, it is demonstrated that the position of the laminar-boundary transition point of a boundary layer can be estimated by using the e-exp-n method. The effect of the Mach number, pressure gradient, and heat transfer on the laminar-turbulent transition is discussed. It is found that under conditions of strong cooling, the effect of the pressure gradient on the position of the transition point is less pronounced than in the absence of heat transfer.

Lysenko, V. I.

1987-01-01

2

Laminar-turbulent cycles in inclined lock-exchange flows.  

PubMed

We consider strongly confined, stably stratified shear flows generated as a lock exchange in a tube inclined at an angle of ?=45(?). This paper focuses on a transitional regime, in which the flow alternates between two distinct states: laminar, parallel shear flow and intense transverse motion characteristic of turbulence. Laminar-turbulent cycles were captured at Atwood numbers At?(?(2)-?(1))/(?(1)+?(2)) ranging from 2.45×10(-3) to 4.0×10(-3), where (?(1),?(2)) are the initial densities of the two fluids, with multiple cycles observed at At=2.55×10(-3). The evolution of the density and velocity fields in these flows was measured simultaneously using laser-induced fluorescence and particle image velocimetry. During each laminar-turbulent cycle, the axial velocity exhibits a distinctive ramp-cliff pattern, indicating that the flow accelerates as it relaminarizes, then decelerates rapidly as the Kelvin-Helmholtz billows break down. Within the range of experimental conditions, transverse stratification does not directly determine the onset of instability. Instead, the data suggest that a necessary criterion for the onset of instability is for the local Reynolds number to exceed 2200, with only a weak dependence on the Richardson number. PMID:23005207

Tanino, Yukie; Moisy, Frédéric; Hulin, Jean-Pierre

2012-06-01

3

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

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

4

Streamwise vortices in laminar-turbulent transition  

NASA Astrophysics Data System (ADS)

The characteristics of a single streamwise vortex embedded in plane Poiseuille flow were analyzed. On short time scales, computations show that velocity profiles evolve similarly to those previously derived in unbounded Couette flow. As boundary effects begin to be felt at later times, a perturbation solution is derived whose profiles and decay rates are found to agree with calculations. Both solutions are used to answer questions about the strength and motion of the vortex, the presence and strength of any counterrotating vortices induced at the viscous boundary, and the possible, or impossible, role of such induced vortices in transition. Time scale arguments are used to derive a neutral curve with a minimum critical Reynolds number close to 1000. The dynamics of a simple model of an isolated polymer molecule embedded in a single vortex flow were also investigated. First, a streamwise vortex embedded in plane Poiseuille flow was numerically simulated, including the effects of streamwise gradients. Then the dynamics of an embedded polymer molecule were introduced using a hybrid ellipsoid-dumbbell model. Regions of positive streamwise strain rate develop within the flow which are of sufficient strength to stretch the polymer to experimentally observed elongations, and then to allow the polymer to relax or entangle. The resulting local increase in viscosity is interpreted within the context of the single streamwise vortex model to infer the local decrease in strength of the associated vortex, the reduced inflectional velocity profiles within the vortex core, and the increased stability of the flow in that region.

Myers, Joseph Dwan

1990-08-01

5

Streamwise Vortices in Laminar-Turbulent Transition.  

NASA Astrophysics Data System (ADS)

The characteristics of a single streamwise vortex embedded in plane Poiseuille flow have been analyzed. On short time scales, computations show that velocity profiles evolve similarly to those previously derived in unbounded Couette flow. As boundary effects begin to be felt at later times, a perturbation solution is derived whose profiles and decay rates are found to agree with calculations. Both solutions are used to answer questions about the strength and motion of the vortex, the presence and strength of any counterrotating vortices induced at the viscous boundary, and the possible--or impossible--role of such induced vortices in transition. Time scale arguments are used to derive a neutral curve (neutrally stable Reynolds number as a function of vertical position in the flow) with a minimum critical Reynolds number close to 1000. The dynamics of a simple model of an isolated polymer molecule embedded in a single streamwise vortex flow have also been investigated. First, a streamwise vortex embedded in plane Poiseuille flow has been numerically simulated, including the effects of streamwise gradients. Then the dynamics of an embedded polymer molecule have been introduced using a hybrid ellipsoid-dumbbell model. Regions of positive streamwise strain rate develop within the flow which are of sufficient strength to stretch the polymer to experimentally observed elongations, and then to allow the polymer to relax or entangle. The resulting local increase in viscosity is interpreted within the context of the single streamwise vortex model to infer the local decrease in strength of the associated vortex, the reduced inflectional velocity profiles within the vortex core, and the increased stability of the flow in that region.

Myers, Joseph Dwan

1990-01-01

6

Nature of laminar-turbulence intermittency in shear flows.  

PubMed

In pipe, channel, and boundary layer flows turbulence first occurs intermittently in space and time: at moderate Reynolds numbers domains of disordered turbulent motion are separated by quiescent laminar regions. Based on direct numerical simulations of pipe flow we argue here that the spatial intermittency has its origin in a nearest neighbor interaction between turbulent regions. We further show that in this regime turbulent flows are intrinsically intermittent with a well-defined equilibrium turbulent fraction but without ever assuming a steady pattern. This transition scenario is analogous to that found in simple models such as coupled map lattices. The scaling observed implies that laminar intermissions of the turbulent flow will persist to arbitrarily large Reynolds numbers. PMID:23848777

Avila, M; Hof, B

2013-06-01

7

Supersonic quiet-tunnel development for laminar-turbulent transition research  

NASA Technical Reports Server (NTRS)

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

Schneider, Steven P.

1995-01-01

8

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

Microsoft Academic Search

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 : DeltaP~1Pa at few 100Hz in the laminar region and DeltaP~10Pa at few kHz in the turbulent region. Intermittent

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

2010-01-01

9

Constrained large-eddy simulation of laminar-turbulent transition in channel flow  

NASA Astrophysics Data System (ADS)

A constrained large-eddy simulation (CLES) of a laminar-turbulent transition in a temporally developing channel flow is performed. First, we confirm the capability of CLES to simulate this transition problem using the a priori Reynolds stress estimated from a direct numerical simulation. Based on the analysis of the Reynolds stress during the transition process, an intermittency factor is introduced in the Reynolds-averaged Navier-Stokes equation (RANS) model to account for the transition property. Two simple approaches are used to construct the intermittency factor. One is based on the shape factor, and the other is based on the coefficients of Smagorinsky models. The CLES results using the intermittency modified RANS model can accurately predict the onset of the transition and the basic transition process, in a manner similar to a large eddy simulation with dynamics Smagorinsky model (LES-DSM). Meanwhile, CLES preserves its advantage over LES-DSM in the turbulent state. The present work illustrates that CLES can be used to simulate transitional flows.

Zhao, Yaomin; Xia, Zhenhua; Shi, Yipeng; Xiao, Zuoli; Chen, Shiyi

2014-09-01

10

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

NASA Technical Reports Server (NTRS)

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

Schneider, Steven P.

1994-01-01

11

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

NASA Technical Reports Server (NTRS)

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.

El-Hady, Nabil M.

1993-01-01

12

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

13

Agricultural Airplane Mission Time Structure Characteristics  

NASA Technical Reports Server (NTRS)

The time structure characteristics of agricultural airplane missions were studied by using records from NASA VGH flight recorders. Flight times varied from less than 3 minutes to more than 103 minutes. There was a significant reduction in turning time between spreading runs as pilot experience in the airplane type increased. Spreading runs accounted for only 25 to 29 percent of the flight time of an agricultural airplane. Lowering the longitudinal stick force appeared to reduce both the turning time between spreading runs and pilot fatigue at the end of a working day.

Jewel, J. W., Jr.

1982-01-01

14

Characteristic Time Scales of Characteristic Magmatic Processes and Systems  

NASA Astrophysics Data System (ADS)

Every specific magmatic process, regardless of spatial scale, has an associated characteristic time scale. Time scales associated with crystals alone are rates of growth, dissolution, settling, aggregation, annealing, and nucleation, among others. At the other extreme are the time scales associated with the dynamics of the entire magmatic system. These can be separated into two groups: those associated with system genetics (e.g., the production and transport of magma, establishment of the magmatic system) and those due to physical characteristics of the established system (e.g., wall rock failure, solidification front propagation and instability, porous flow). The detailed geometry of a specific magmatic system is particularly important to appreciate; although generic systems are useful, care must be taken to make model systems as absolutely realistic as possible. Fuzzy models produce fuzzy science. Knowledge of specific time scales is not necessarily useful or meaningful unless the hierarchical context of the time scales for a realistic magmatic system is appreciated. The age of a specific phenocryst or ensemble of phenocrysts, as determined from isotopic or CSD studies, is not meaningful unless something can be ascertained of the provenance of the crystals. For example, crystal size multiplied by growth rate gives a meaningful crystal age only if it is from a part of the system that has experienced semi-monotonic cooling prior to chilling; crystals entrained from a long-standing cumulate bed that were mechanically sorted in ascending magma may not reveal this history. Ragged old crystals rolling about in the system for untold numbers of flushing times record specious process times, telling more about the noise in the system than the life of typical, first generation crystallization processes. The most helpful process-related time scales are those that are known well and that bound or define the temporal style of the system. Perhaps the most valuable of these times comes from the observed durations and rates of volcanism. There can be little doubt that the temporal styles of volcanism are the same as those of magmatism in general. Volcano repose times, periodicity, eruptive fluxes, acoustic emission structures, lava volumes, longevity, etc. must also be characteristic of pluton-dominated systems. We must therefore give up some classical concepts (e.g., instantaneous injection of crystal-free magma as an initial condition) for any plutonic/chambered system and move towards an integrated concept of magmatism. Among the host of process-related time scales, probably the three most fundamental of any magmatic system are (1) the time scale associated with crystal nucleation (J) and growth (G) (tx}=C{1(G3 J)-{1}/4; Zieg & Marsh, J. Pet. 02') along with the associated scales for mean crystal size (L) and population (N), (2) the time scale associated with conductive cooling controlled by a local length scale (d) (tc}=C{2 d2/K; K is thermal diffusivity), and (3) the time scale associated with intra-crystal diffusion (td}=C{3 L2/D; D is chemical diffusivity). It is the subtle, clever, and insightful application of time scales, dovetailed with realistic system geometry and attention paid to the analogous time scales of volcanism, that promises to reveal the true dynamic integration of magmatic systems.

Marsh, B. D.

2004-05-01

15

Stochastic Modeling of Laminar-Turbulent Transition  

NASA Technical Reports Server (NTRS)

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.

Rubinstein, Robert; Choudhari, Meelan

2002-01-01

16

Predicting river travel time from hydraulic characteristics  

USGS Publications Warehouse

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.

Jobson, H.E.

2001-01-01

17

Characteristics of anisometropic suppression: Simple reaction time measurements  

Microsoft Academic Search

The characteristics of artificially induced anisometropic suppression were investigated in observers with normal and abnormal\\u000a binocular vision (anisometropic amblyopia) by using a simple reaction time paradigm. Reaction time was measured as a function\\u000a of stimulus intensity for various stimulus durations. For all conditions, the reaction time increased as stimulus intensity\\u000a decreased toward threshold. We found that traditional techniques for modeling

Michael J. Planta; Michael Kalloniatis

1998-01-01

18

Macroscopic effects of reaction time on traffic flow characteristics  

NASA Astrophysics Data System (ADS)

Reaction time is defined as a physiological parameter reflecting the period of time between perceiving a stimulus and performing a relevant action. In the traffic flow theory literature, the effects of reaction time on string stability have been described using the microscopic modeling approach. This paper presents a distinct approach to investigate how reaction time influences traffic flow stability using a macroscopic model. In the paper, the distinction between string stability and flow stability is defined. The flow stability conditions are derived based on the macroscopic model, which is developed from a gas-kinetic principle. From linear analysis, we find that at macroscopic scale the reaction time influences how instabilities propagate but does not contribute to whether those (linear) instabilities occur. Nevertheless, nonlinear analysis might give a different view on the impact of reaction time on traffic flow stability, but the effect is nonlinear. We argue that the findings provide a better understanding of the effects of reaction time on traffic flow characteristics.

Ngoduy, D.; Tampere, C.

2009-08-01

19

Time-varying characteristics of visually induced postural sway.  

PubMed

To study potential time-varying dynamics of postural sway as measured via center-of-pressure (COP) under the feet, we applied time-frequency analysis to COP data from ten vestibularly impaired subjects and 13 nonimpaired controls, during quiet stance and in response to visual perturbation. This analysis revealed that 1) the spectral characteristics of COP change over time; 2) there are time-dependent and frequency-dependent differences in COP between impaired and nonimpaired populations during visual perturbation, and 3) there is no difference in COP during quiet stance (eyes opne) between impaired and nonimpaired populations for the parameters investigated. A novel finding of this research is that controls appear to adapt to constant frequency visual perturbation, while vestibularly impaired subjects do not. This difference could not have been observed with conventional Fourier analysis, which is commonly used in COP data analysis, because time is not a parameter of the spectrum and adaptation is, by nature, a time-varying process. These results suggest that time-frequency analysis of COP data is useful for studying temporal dynamics of postural control, and in particular the differences between vestibularly impaired subjects and healthy controls during visual perturbation. PMID:8973968

Loughlin, P J; Redfern, M S; Furman, J M

1996-12-01

20

Effects of Accuracy Feedback on Fractal Characteristics of Time Estimation  

PubMed Central

The current experiment investigated the effect of visual accuracy feedback on the structure of variability of time interval estimates in the continuation tapping paradigm. Participants were asked to repeatedly estimate a 1-s interval for a prolonged period of time by tapping their index finger. In some conditions, participants received accuracy feedback after every estimate, whereas in other conditions, no feedback was given. Also, the likelihood of receiving visual feedback was manipulated by adjusting the tolerance band around the 1-s target interval so that feedback was displayed only if the temporal estimate deviated from the target interval by more than 50, 100, or 200?ms respectively. We analyzed the structure of variability of the inter-tap intervals with fractal and multifractal methods that allow for a quantification of complex long-range correlation patterns in the timing performance. Our results indicate that feedback changes the long-range correlation structure of time estimates: Increased amounts of feedback lead to a decrease in fractal long-range correlations, as well to a decrease in the magnitude of local fluctuations in the performance. The multifractal characteristics of the time estimates were not impacted by the presence of accuracy feedback. Nevertheless, most of the data sets show significant multifractal signatures. We interpret these findings as showing that feedback acts to constrain and possibly reorganize timing performance. Implications for mechanistic and complex systems-based theories of timing behavior are discussed. PMID:22046149

Kuznetsov, Nikita A.; Wallot, Sebastian

2011-01-01

21

Potentially hazardous comet warning times, characteristics, trends and countermeasures  

NASA Astrophysics Data System (ADS)

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.

Phelps, Lyrica L.

22

Characteristic distributions of finite-time Lyapunov exponents.  

PubMed

We study the probability densities of finite-time or local Lyapunov exponents in low-dimensional chaotic systems. While the multifractal formalism describes how these densities behave in the asymptotic or long-time limit, there are significant finite-size corrections, which are coordinate dependent. Depending on the nature of the dynamical state, the distribution of local Lyapunov exponents has a characteristic shape. For intermittent dynamics, and at crises, dynamical correlations lead to distributions with stretched exponential tails, while for fully developed chaos the probability density has a cusp. Exact results are presented for the logistic map, x-->4x(1-x). At intermittency the density is markedly asymmetric, while for "typical" chaos, it is known that the central limit theorem obtains and a Gaussian density results. Local analysis provides information on the variation of predictability on dynamical attractors. These densities, which are used to characterize the nonuniform spatial organization on chaotic attractors, are robust to noise and can, therefore, be measured from experimental data. PMID:11970080

Prasad, A; Ramaswamy, R

1999-09-01

23

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

ERIC Educational Resources Information Center

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

Frech, Adrianne; Kimbro, Rachel Tolbert

2011-01-01

24

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...

25

Embayment characteristic time and biology via tidal prism model  

Microsoft Academic Search

Transport time scales are often offered by scientists, and accepted by ecologists, as qualitative indicators of the susceptibility of ecological components within an embayment. However, rigorous quantitative methods were never presented to confirm this intuition. Transport time scales in water bodies are classically based on their physical and chemical aspects rather than their ecological and biological character. The direct connection

Mohamed A. Abdelrhman

2007-01-01

26

A bypass wake induced laminar\\/turbulent transition  

Microsoft Academic Search

The process of laminar to turbulent transition induced by a von Karman vortex street wake, was studied for the case of a flat plate boundary layer. The boundary layer developed under zero pressure gradient conditions. The vortex street was generated by a cylinder positioned in the free stream. An X-type hot-wire probe located in the boundary layer, measured the streamwise

N. K. Kyriakides; E. G. Kastrinakis; S. G. Nychas; A. Goulas

1999-01-01

27

Laminar/turbulent oscillating flow in circular pipes  

NASA Technical Reports Server (NTRS)

A two-dimensional oscillating flow analysis was conducted simulating the gas flow inside Stirling engine heat exchangers. Both laminar and turbulent oscillating pipe flow were investigated numerically for Re(max) = 1920 (Va = 80), 10,800 (Va = 272), 19,300 (Va = 272), and 60,800 (Va = 126). The results are compared with experimental results of previous investigators. Predictions of the flow regime are also checked by comparing velocity amplitudes and phase difference with those from laminar theory and quasi-steady profile. A high Reynolds number k-epsilon turbulence model was used for turbulent oscillating pipe flow. Finally, the performance of the k-epsilon model was evaluated to explore the applicability of quasi-steady turbulent models to unsteady oscillating flow analysis.

Ahn, Kyung H.; Ibrahim, Mounir B.

1992-01-01

28

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

Microsoft Academic Search

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,

Roland A. Knapp; Vance T. Vredenburg

1996-01-01

29

Time Domain Reflectometry Technique for Monitoring of Liquid Characteristics  

Microsoft Academic Search

Time domain reflectometry (TDR) technique 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, a unique approach of pulsing a long coaxial probe and analysing the reflected voltage signature caused by changes

A. Cataldo; L. Tarricone; A. Trotta; F. Attivissimo; C. Urso

2005-01-01

30

Long Characteristic Method in Space and Time for Transport Problems  

E-print Network

................................................................................................ 87 Figure 18 STLC Scalar Flux Solution (c = 0.9999999) (a) Non-TWC (b) Time Profile ................................................................................................ 88 Figure 19 Comparison of Solutions at T = 5 ms (a) Full... T B R L i m n i m n i m n i m n m t i m n n i i ns i n i n v t x mQ i I y y y ym s y s y y #16; #17; #16; #17;- -+ + #18; #19; #18; #19;D D #20; #21; #20; #21; == + + = (2.26) ( ) , , , , , , , , , , , , , , , ,1, ,2, 21 3 1,2, 1,...2 2 T x B x R L...

Pandya, Tara M.

2010-07-14

31

Space--time characteristics of single-mode injection lasers  

SciTech Connect

In this paper we discuss results from a study of space-time nonuniformity of light from injection lasers with a short emitting region (less than 10 ..mu..m long) operating in the fundmental transverse mode. In the experiments we tested injection lasers with a transverse p-n junction or with a mesastripe contact of width 5 ..mu..m fabricated by selective etching of the contact layer. The samples formed a Fabry--Perot cavity of length 200--250 ..mu.. and were mounted by an n-type contact on a crystal holder. The threshold currents I/sub thr/ in the tested lasers were 30-35 mA for lasers with a transverse p--n junction and 45-60 mA for lasers with a mesastripe contact.(AIP)

Borodulin, V.I.; Zverkov, M.V.; Konyaev, V.P.; Lamanov, A.L.; Pashko, S.A.; Trapeznikov, M.B.; Shveikin, V.I.

1983-12-01

32

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

SciTech Connect

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.

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

33

Robust blind dereverberation of speech signals based on characteristics of short-time speech segments  

Microsoft Academic Search

This paper addresses blind dereverberation techniques based on the inherent characteristics of speech signals. Two challenging issues for speech dereverberation involve decomposing reverberant observed signals into colored sources and room transfer functions (RTFs), and making the inverse filtering robust as regards acoustic and system noise. We show that short-time speech characteristics are very important for this task, and that multi-channel

Tomohiro Nakatani; Takafumi Hikichi; Keisuke Kinoshita; Takuya Yoshioka; Marc Delcroix; Masato Miyoshi; Biing-hwang Juang

2007-01-01

34

The Impact of Item Format and Examinee Characteristics on Response Times  

ERIC Educational Resources Information Center

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

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

2013-01-01

35

The Effects of Time Lapse on Personality Characteristics and Stress on Divorced Women.  

ERIC Educational Resources Information Center

Hypothesized that maladjustment and stress are present in divorced women but diminish over time. Four groups divorced for different time spans were studied. Personality characteristics of the groups were analyzed. Results indicated that psychological maladjustment in women diminishes over time. (Author)

Spivey, Patricia B.; Scherman, Avraham

1980-01-01

36

Estimation of characteristic parameters in region-time-length algorithm and its application  

NASA Astrophysics Data System (ADS)

On the basis of gap’s temporal-spatial characteristics in and around source area before an earthquake, we propose a method to estimate characteristic parameters (characteristic distance and time) in the region-time-length (RTL) algorithm and introduce the method of correlation coefficient developed by some authors in 2006 to determine the characteristic parameters. The anomalous seismic activities before four moderately strong earthquakes occurred in the northwestern and southwestern China in recent years are studied by the two methods. The results show that the method to estimate characteristic parameters advanced in this paper is a simple one, which possesses a physical meaning and is well applicable to the four moderately strong earthquakes studied.

Rong, Dai-Lu; Li, Ya-Rong

2007-05-01

37

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-Domain Spectroscopy Jiaguang Han, Weili Zhang,*, Wei Chen,§ L. Thamizhmani, Abul K. Azad, and Zhiyuan Zhu Shanghai of terahertz time-domain spectroscopy (THz-TDS) over the frequency range from 0.3 to 3.0 THz. The effective

38

Time-current characteristics and minimum fusing current of R-113 on a horizontal wire  

SciTech Connect

This paper reports on an experimental and analytical investigation to determine the time-current characteristics and the minimum fusing current for a horizontal submerged metallic (Cu, Pb) wire, undergoing a step in Joule heating applied by ac current leading to boiling on its surface. The experiment were performed using R-113 at atmospheric pressure with a pool temperature of about 30K subcooled, and also in air. The time-current characteristic with boiling had a steep slope, and the minimum fusing current was very large compared to that obtained in air. The fusion of the wire with boiling was a physical burn-out phenomenon, and the time to interruption was in the region of film boiling. The time-current characteristics were simulated for various wires by using a thermal network.

Fujii, M.; Ikeuchi, M. (Mitsubishi Electric Corp. (JP))

1991-01-01

39

Relationships among time orientation, consumer innovativeness, and innovative behavior: the moderating role of product characteristics  

Microsoft Academic Search

Consumer innovativeness is a critical factor that determines the success of new product introductions. An important but underexplored\\u000a antecedent of consumer innovativeness is time orientation. In this article, we propose a conceptual model of the relationships\\u000a among time orientation, consumer innovativeness, and consumer innovative behavior. We further examine the moderating role\\u000a of several important product characteristics on these relationships. These

Kiran Karande; Altaf Merchant; K. Sivakumar

40

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

Microsoft Academic Search

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.

Steven G. Brandl; Meghan S. Stroshine

2011-01-01

41

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

ERIC Educational Resources Information Center

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…

Hyun, Eunsook; Kretovics, Mark; Crowe, Alicia

2006-01-01

42

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

E-print Network

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.

R. Aldrovandi

2013-10-13

43

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

E-print Network

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

Tian, Jie

44

Backgrounds and Characteristics of New Full-Time Community College Faculty Members.  

ERIC Educational Resources Information Center

This paper reports the results of an 11 item questionnaire designed to ascertain the personal characteristics and backgrounds of newly-hired faculty in the 19 state North Central region. Useable responses were obtained from 406 full-time community college faculty who were hired for the 1973-74 school year. Ninety-six percent were white, 57 percent…

Brown, James L.

45

Computing Quantitative Characteristics of Finite State RealTime Systems \\Lambda  

E-print Network

by the Avionics Laboratory, Wright Research and Development Center, Aeronautical Systems Division (AFSC), U.S. AirComputing Quantitative Characteristics of Finite State Real­Time Systems \\Lambda S. Campos, E and should not be interpreted as representing the official policies, either expressed or implied of the U.S

Marrero, Will

46

Response Time of Broiler Chickens to Cimaterol: Meat Tenderness, Muscle Composition, Fiber Size, and Carcass Characteristics  

Microsoft Academic Search

The response time to cimaterol (CIM), a P-adrenergic agonist, by broiler chickens for carcass characteristics, muscle composition, muscle fiber size, catheptic enzyme activity, and tenderness was determined. Two trials were con- ducted in which chickens were fed a control diet (CON) containing 0 ppm of CIM or a diet contain- ing 1 ppm of CIM. Trial 1 consisted of 55,

B. L. Gwartney; S. J. Jones; C. R. Calkins

2010-01-01

47

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

ERIC Educational Resources Information Center

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

Mero, Antti

1988-01-01

48

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

PubMed

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

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

2014-01-01

49

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

NASA Astrophysics Data System (ADS)

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

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

50

Estimating characteristic phase and delay from broadband interaural time difference tuning curves.  

PubMed

Characteristic delay and characteristic phase are shape parameters of interaural time difference tuning curves. The standard procedure for the estimation of these parameters is based on the measurement of delay curves measured for tonal stimuli with varying frequencies. Common to all procedures is the detection of a linear behavior of the phase spectrum. Hence a reliable estimate can only be expected if sufficiently many relevant frequencies are tested. Thus, the estimation precision depends on the given bandwidth. Based on a linear model, we develop and implement methods for the estimation of characteristic phase and delay from a single broadband tuning curve. We present two different estimation algorithms, one based on a Fourier-analytic interpretation of characteristic delay and phase, and the other based on mean square error minimization. Estimation precision and robustness of the algorithms are tested on artificially generated data with predetermined characteristic delay and phase values, and on sample data from electrophysiological measurements in birds and in mammals. Increasing the signal-to-noise ratio or the bandwidth increases the estimation accuracy of the algorithms. Frequency band location and strong rectification also affect the estimation accuracy. For realistic bandwidths and signal-to-noise ratios, the minimization algorithm reliably and robustly estimates characteristic delay and phase and is superior to the Fourier-analytic method. Bandwidth-dependent significance thresholds allow to assess whether the estimated characteristic delay and phase values are meaningful shape parameters of a measured tuning curve. These thresholds also indicate the sampling rates needed to obtain reliable estimates from interaural time difference tuning curves. PMID:25278284

Lehmann, Jessica; Tellers, Philipp; Wagner, Hermann; Führ, Hartmut

2015-02-01

51

Chemical modification of proroot mta to improve handling characteristics and decrease setting time.  

PubMed

Mineral trioxide aggregate (MTA) fulfills many of the ideal properties of a root-end filling material. However, the composition of this material often makes MTA difficult to use, a direct result of its granular consistency, slow setting time, and initial looseness. Additives used by the Portland cement (PC) industry to increase PC's plasticity and decrease its setting time were added first to PC and then to gray MTA in an attempt to improve MTA's handling characteristics, with the combination providing the best handling characteristics tested for its effect on compressive strength (for changes in the original material's properties) and decrease in setting time. An admix of 1% methylcellulose and 2% calcium chloride resulted in a mix of chemically modified MTA that, when compared with unmodified MTA, (1) handled similarly to a reinforced zinc oxide-eugenol cement, (2) gave an approximately equal compressive strength, and (3) set one third faster (57 +/- 3 minutes). PMID:17889696

Ber, Benjamin S; Hatton, John F; Stewart, Gregory P

2007-10-01

52

Characteristics and stability of aerobic granules cultivated with different starvation time  

Microsoft Academic Search

The characteristics of aerobic granules at steady state and the effects of starvation time on the stability of aerobic granules\\u000a during the long-term operation were investigated in three sequencing batch reactors (SBRs R1–R3). The SBRs were operated with\\u000a a cycle time of 1.5, 4.0, and 8.0 h, respectively, which resulted in a starvation time of 0.8, 3.3, and 7.3 h in three

Yong-Qiang Liu; Joo-Hwa Tay

2007-01-01

53

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

54

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

SciTech Connect

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

Advani, S.H.; Lee, T.S. (Lehigh Univ., Bethlehem, PA (United States)); Moon, H. (Ohio State Univ., Columbus, OH (United States))

1992-10-01

55

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

SciTech Connect

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

Advani, S.H.; Lee, T.S. [Lehigh Univ., Bethlehem, PA (United States); Moon, H. [Ohio State Univ., Columbus, OH (United States)

1992-10-01

56

Breakdown and Voltage–Time Characteristics of Turn-to-Turn Models for an HTS Transformer  

Microsoft Academic Search

The breakdown and voltage-time characteristics of turn-to-turn models for point contact geometry and surface contact geometry using copper multiwrapped with polyimide film for a high-temperature superconducting transformer were investigated under ac and impulse voltage at 77 K. Polyimide film (Kapton) 0.025 mm thick is used for multiwrapping of the electrode. As expected, the breakdown voltages for the surface contact geometry

Seung Myeong Baek; Sang Hyun Kim

2008-01-01

57

Determining Optimal Processor Speeds for Periodic Real-Time Tasks with Different Power Characteristics  

Microsoft Academic Search

In this paper, we provide an efficient solution for peri- odic real-time tasks with (potentially) different power consumption characteristics. We show that, a task T, can run at a constant speed 5';. at every instance without hurting optimality. We sketch an O(n2 log n) algorithm to compute the optimal S;. values. We also prove that the EDF (Earliest Deadline First)

Hakan Aydin; Rami G. Melhem; Daniel Mossé; Pedro Mejia-Alvarezt

2001-01-01

58

Electron irradiation for adjusting the reverse recovery time and forward voltage drop characteristics of fast diodes  

NASA Astrophysics Data System (ADS)

The electron linear accelerator ALIN-10 has been used to irradiate at room temperature and high temperature silicon diodes type BA159, BAX157 and 6DRR1 (manufacturer - Baneasa S.A.-factory 2300, Romania). The influence of 10 MeV electron irradiation upon the main electrical characteristics (reverse recovery time, forward voltage, reverse current) has been examined for different absorbed doses (10-50 kGy) and different irradiation temperatures (25°C, 175°C, 250°C). The dependence of the minority carrier lifetime, reverse recovery time and forward voltage on the radiation dose, and the percentage distribution (%) of the reverse recovery time and of the reverse current for the irradiated diodes are presented. A comparison between the electrical performances of the fast diodes obtained by electron irradiation and the electrical performances of the fast diodes obtained by gold or platinum diffusion has been made.

Iliescu, Elena; Niculescu, Anastase; Banu, Viorel; Nichita, Anca; Sturzu, Nicoleta

1998-04-01

59

Performance characteristics and clinical evaluation of an in vitro bleeding time device--Thrombostat 4000.  

PubMed

The performance characteristics of an in vitro bleeding time device--Thrombostat 4000 were evaluated and compared with the Simplate bleeding time in healthy individuals and patients with disorders of primary hemostasis. Reference ranges were established using 30 normal volunteers. Although there were variations between different filter batches, reproducibility was good within a single batch. There were no differences between the two channels of the instrument and between male and female subjects. Hematocrit correlated negatively with the initial flow (IF) and IF correlated positively with closure time (T) and bleeding volume (V). Aspirin could be detected only when the traditional addition of ADP was replaced with CaCl2. Both, closure time (T) or bleeding volume (V) were more sensitive than Simplate bleeding time and T was more sensitive than V in detecting patients with disorders of primary hemostasis. We conclude that the Thrombostat 4000 is a reproducible, reliable, sensitive and easy to use instrument. It is superior to the traditional in vivo bleeding times for investigations of disorders of primary hemostasis (screening, diagnosis, monitoring, etc.). PMID:8533123

Alshameeri, R S; Mammen, E F

1995-08-01

60

Time-dependent radiation characteristics of Nannochloropsis oculata during batch culture  

NASA Astrophysics Data System (ADS)

This paper reports the temporal evolution of the scattering and absorbing cross-sections of marine eustigmatophycease Nannochloropsis oculata grown in a flat-plate photobioreactor (PBR). The PBR was operated in batch mode under constant irradiance of 7500 or 10,000 lux provided by red LEDs emitting at 630 nm. The radiation characteristics between 400 and 750 nm and pigment concentrations of N. oculata were measured systematically every 24 h for up to 18 days. They were found to vary significantly with time in response to changes in light and nutrients availability. The results were interpreted in terms of up- and down-regulations of pigments and other intracellular components. Finally, this study demonstrates that the light transfer in the PBR could be predicted using constant radiation characteristics measured during the exponential growth phase with reasonable accuracy provided that the cultures were not nitrogen limited. During nitrogen starvation, pigment concentrations decreased and radiation characteristics evolved rapidly. These results will be useful in the design and operation of PBRs for biofuel production at both small and large scales.

Heng, Ri-Liang; Pilon, Laurent

2014-09-01

61

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

PubMed Central

Study Objectives: To investigate the associations of specific neighborhood features (disorder, safety, social cohesion, physical environment, and socioeconomic status) with sleep duration and quality. Design: Cross-sectional. One wave of a population-based study (Multi-Ethnic Study of Atherosclerosis). Setting: Community-dwelling participants in New York, NY and Los Angeles, CA. Participants: There were 1,406 participants (636 males, 770 females). Interventions: NA. Measurements and Results: Sleep was assessed using reported hours of sleep, the Epworth Sleepiness Scale, and insomnia symptoms. Neighborhood characteristics were assessed via questionnaires administered to neighbors of study participants and were aggregated to the neighborhood (census tract) level using empirical Bayes estimation. An adverse social environment (characterized by high disorder, and low safety and social cohesion) was associated with shorter sleep duration after adjustment for the physical environment, neighborhood and individual-level socioeconomic status (SES), and other short sleep risk factors (mean difference per standard deviation increase in summary social environment scale 0.24 h 95% confidence interval 0.08, 0.43). Adverse neighborhood social and physical environments, and neighborhood SES were associated with greater sleepiness, but associations with physical environments were no longer statistically significant after adjustment for sociodemographic characteristics. Neighborhood SES was a weaker and less consistent predictor of specific measures of neighborhood social and physical environments. Neighborhood characteristics were not associated with insomnia. Conclusions: Shortened sleep related to adverse social environments represents one potential pathway through which neighborhoods may influence health. Citation: DeSantis AS; Diez Roux AV; Moore K; Baron KG; Mujahid MS; Nieto FJ. Associations of neighborhood characteristics with sleep timing and quality: the multi-ethnic study of atherosclerosis. SLEEP 2013;36(10):1543-1551. PMID:24082314

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

2013-01-01

62

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

63

Evaluation for EAPSM life time by ArF pellicle characteristic  

NASA Astrophysics Data System (ADS)

As the nano-lithography technology continues to develop towards advanced generation of ArF immersion lithography, the quality of ArF EAPSM becomes the most valuable factor for worldwide Maskshop. Therefore outturn of ArF EAPMS increase continuously, and people who work in the fields of semiconductor engineering give consequence to good quality of ArF EAPSM until the EUV lithography generation. Because 300mm wafer litho-facility use higher exposure energy, wider shot field and more shots per a wafer for achieving more memory(DRAM or Flash) chips than 200mm exposure facility, photo engineer wants unchanged initial condition of mask quality(CD MTT, CD Uniformity, repeating defect, phase shift and transmittance). In other words, mask manufacturer must focus on the concept of ArF EAPSM 'life time'. We have investigated the influence grade inducing the lithographic variation between the growth of exposure energy based Haze phenomena, thin organic pellicle membrane characteristics, and we have verified that the ArF pellicle durability is one of the most important evidence for improvement of life time of ArF EAPSM. In this study, related with ArF EAPSM life time, we tried to evaluate the influence of ArF pellicle characteristic consisting of pellicle membrane transmittance strength (durability against ArF laser source) and non acid mask condition for the period of non Haze contamination without added re-pellicle --> re-cleaning cycle. Metrological inspection and evaluation was conducted with several equipment and analysis including mask inspection, Scatterometer, IC, ArF laser accelerator.

Seo, Kang Joon; Ryu, Ji Sun; Jeong, Goo Min; Kang, Shin Cheol; Kim, Yong Dae; Kim, Sang Chul; Kim, Chang Yeol

2009-04-01

64

Observed spatiotemporal characteristics of drought on various time scales over the Czech Republic  

NASA Astrophysics Data System (ADS)

This paper analyses the observed spatiotemporal characteristics of drought in the Czech Republic during the growing season (April to September) as quantified using the Standardised Precipitation Evapotranspiration Index (SPEI) on various time scales. The SPEI was calculated for various lags (1, 3, 6, 12, and 24 months) from monthly records of mean temperature and precipitation totals using a dense network of 184 climatological stations for the period 1961-2010. The characteristics of drought were analysed in terms of the temporal evolution of the SPEI, the frequency distribution and duration of drought at the country level, and for three regions delimited by station altitude. The driest and the wettest years during the growing season were identified. The frequency distribution of the SPEI values for seven drought category classes (in per cent) indicates that normal moisture conditions represent approximately 65 % of the total SPEI values for all time scales in all three regions, whereas moderate drought and moderate wet conditions are almost equally distributed around 10.5 %. Differences in extremely dry conditions (5 %) compared with extremely wet conditions (1.5 %) were observed with increasing SPEI time scales. The results of the non-parametric Mann-Kendall trend test applied to the SPEI series indicate prevailing negative trends (drought) at the majority of the stations. The percentage of stations displaying a significant negative trend for the 90, 95, 99, and 99.9 % confidence levels is approximately 40 %. An Empirical Orthogonal Functions (EOF) analysis was used to identify the principal patterns of variability of the SPEI during the growing season that accounted for the highest amount of statistical variance. The variance explained by the leading EOF range 66 to 56 %, whereas for EOF2 and EOF3, the value is between 7 and 11 % and between 4 and 7 %, respectively, for the SPEI is calculated for 1- to 24-month lags.

Potop, Vera; Boronean?, Constan?a; Možný, Martin; Št?pánek, Petr; Skalák, Petr

2014-02-01

65

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

ERIC Educational Resources Information Center

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

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

2013-01-01

66

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

PubMed Central

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

Singh, Jasvinder A.; Lewallen, David G.

2014-01-01

67

Research of Amplitude - Time Characteristic of Television Signal Reflected From a Meteoric Trail in Spased Radar System  

Microsoft Academic Search

In this paper the technique of processing the television signal reflected from a meteoric trail for research of parameters of amplitude-time characteristics of signals in the spased radar system is considered.

A. N. Oleynikov; D. M. Sosnovchik

2006-01-01

68

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

PubMed

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

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

2012-12-01

69

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

NSDL National Science Digital Library

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 μm to 3.3 μm and the image analysis a range of about 6 μm to 1 μm 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.

Luginbuhl, Kelli M.

2010-08-15

70

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

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

71

Characteristics and performance of aerobic granular sludge treating rubber wastewater at different hydraulic retention time.  

PubMed

The influence of hydraulic retention time (HRT, 24, 12, and 6h) on the physical characteristics of granules and performance of a sequencing batch reactor (SBR) treating rubber wastewater was investigated. Results showed larger granular sludge formation at HRT of 6h with a mean size of 2.0±0.1mm, sludge volume index of 20.1mLg(-1), settling velocity of 61mh(-1), density of 78.2gL(-1) and integrity coefficient of 9.54. Scanning electron microscope analyses revealed different morphology of microorganisms and structural features of granules when operated at various HRT. The results also demonstrated that up to 98.4% COD reduction was achieved when the reactor was operated at low HRT (6h). Around 92.7% and 89.5% removal efficiency was noted for ammonia and total nitrogen in the granular SBR system during the treatment of rubber wastewater. PMID:24704837

Rosman, Noor Hasyimah; Nor Anuar, Aznah; Chelliapan, Shreeshivadasan; Md Din, Mohd Fadhil; Ujang, Zaini

2014-06-01

72

Second order modified method of characteristics mixed defect-correction finite element method for time dependent Navier–Stokes problems  

Microsoft Academic Search

In this paper, a second order modified method of characteristics defect-correction (SOMMOCDC) mixed finite element method\\u000a for the time dependent Navier–Stokes problems is presented. In this method, the hyperbolic part (the temporal and advection\\u000a term) are treated by a second order characteristics tracking scheme, and the non-linear term is linearized at the same time.\\u000a Then, we solve the equations with

Zhiyong Si

73

Influence of age and aerobic fitness on the multifractal characteristics of electrocardiographic RR time-series  

PubMed Central

Multifractal properties of electrocardiographic inter-beat (RR) time-series offer insight into its long-term correlation structure, independently of RR variability. Here we quantify multifractal characteristics of RR data during 24-h diurnal-nocturnal activity in healthy participants. We tested the hypotheses that (1) age, gender and aerobic fitness influence RR multifractal properties, and that (2) these are influenced by circadian variation. Seventy adults (39 males) aged 19–58 years and of various fitness levels were monitored using 24-h ECG. Participants were dichotomized by median age and fitness for sub-group analysis. Gender and fitness were independent of age (p = 0.1, p > 0.5). Younger/older group ages were substantially different (p < 0.0005) and were independent of gender and fitness. Multifractality was quantified using the probability spectrum of Hölder exponents (h), from which modal h (h*) and the full-width and half-widths at half-maximum measures (FWHM, HWHM+, and HWHM?) were derived. FWHM decreased (p = 0.004) and h* increased (p = 0.011) in older people, indicating diminished long-range RR correlations and weaker anti-persistent behavior. Anti-persistent correlation (h*) was strongest in the youngest/fittest individuals and weakest in the oldest/least fit individuals (p = 0.015). Long-range correlation (HWHM+/FWHM) was strongest in the fittest males and weakest in the least fit females (p = 0.007–0.033). Multifractal RR characteristics in our healthy participants showed strong age-dependence, with diminished long-range anti-persistent correlation in older people. Circadian variation of these characteristics was influenced by fitness and gender: fitter males and females of all ages had the greatest degree of multifractality or long-range order. Multifractal characterization appears to be a useful method for exploring the physiological basis of long-term correlation structure in RR time-series as well as the benefits thereon of physical fitness training. PMID:23717283

Lewis, Michael J.; McNarry, Melitta A.

2013-01-01

74

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

PubMed

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

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

2013-10-01

75

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

NASA Technical Reports Server (NTRS)

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

Lo, C. C.; Leskovar, B.

1976-01-01

76

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

PubMed Central

OBJECTIVE To estimate the association between neighborhood contextual variables and leisure-time physical activity. METHODS Data were analyzed for 2,674 adults from Rio de Janeiro, RJ, Southeastern Brazil, participating in the longitudinal study in 1999. Leisure-time physical activity in the two preceding weeks was assessed dichotomously. Sex, age, income, education and marital status were analyzed as individual variables. Neighborhood contextual characteristics were the social development index, the Theil index and the proportion of the area occupied by parks, squares and gardens, categorized in quintiles. The unadjusted and adjusted odds ratios and 95% confidence intervals were estimated using multilevel logistic regression. RESULTS The prevalence of leisure-time physical activity was higher in residents in neighborhoods with higher indices of social development (between 32.3% and 53.1%) and a greater proportion of parks, squares and gardens (between 35.8% and 53.1%). Regarding the social development index, the adjusted odds ratios for physical activity were 1.22 (95%CI 0.93;1.61), 1.44 (95%CI 1.09;1.89), 1.75 (95%CI 1.31;2.34) and 2.25 (95%CI 1.70;3.00) for residents in neighborhoods in the second, third, fourth and fifth quintiles, respectively, compared with residents in neighborhoods in the first quintile. The odds ratios for the proportion of parks, squares and gardens were 0.90 (95%CI 0.69;1.19), 1.41 (95%CI 1.04;1.90), 1.63 (95%CI 1.24;2.14) and 1.05 (95%CI 0.80;1.38) for residents in neighborhoods in the second, third, fourth and fifth quintiles. After adjusting for the other variables, only the social development index continued to be associated with leisure-time physical activity, with odds ratios of 1.41 (95%CI 1.02;1.95); 1.54 (95%CI 1.12;2.12); 1.65 (95%CI 1.14;2.39) and 2.13 (95%CI 1.40;3.25) for residents in neighborhoods in the second, third, fourth and fifth quintiles. CONCLUSIONS Leisure-time physical activity was more common in residents in neighborhoods with higher social development indices. No association was observed between access to leisure areas and income inequality. PMID:24897046

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

2014-01-01

77

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

PubMed Central

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

2013-01-01

78

Identification of Land-Cover Characteristics Using MODIS Time Series Data: An Application in the Yangtze River Estuary  

PubMed Central

Land-cover characteristics have been considered in many ecological studies. Methods to identify these characteristics by using remotely sensed time series data have previously been proposed. However, these methods often have a mathematical basis, and more effort is required to better illustrate the ecological meanings of land-cover characteristics. In this study, a method for identifying these characteristics was proposed from the ecological perspective of sustained vegetation growth trend. Improvement was also made in parameter extraction, inspired by a method used for determining the hyperspectral red edge position. Five land-cover types were chosen to represent various ecosystem growth patterns and MODIS time series data were adopted for analysis. The results show that the extracted parameters can reflect ecosystem growth patterns and portray ecosystem traits such as vegetation growth strategy and ecosystem growth situations. PMID:23894594

Zhang, Mo-Qian; Guo, Hai-Qiang; Xie, Xiao; Zhang, Ting-Ting; Ouyang, Zu-Tao; Zhao, Bin

2013-01-01

79

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

80

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

Microsoft Academic Search

The north polar region is dominated by the polar cap cut by troughs and Chasma Boreale, surrounded by the north polar erg and overlying the Vastitas Borealis Formation. A thin layer of mantle with characteristic \\

M. A. Kreslavsky; J. W. Head

2002-01-01

81

The Research of Static Var Compensator's Time Characteristics and System-level Model of Controlled Current Source  

NASA Astrophysics Data System (ADS)

In the status of lacking research on response time of static var compensator (SVC), this paper established the controlled current source model which can achieve the same effect in response time and reactive compensation with the physical model of SVC by analyzing of characteristics in reactive power compensation and the response of the static var compensator (SVC) physical model. Through the time module in control signal of controlled current source, it can accurately calculate the response time of SVC. It tested the consistency of two models through the simulation of a rolling mill start experiment in PSCAD.

Zhang, Chao; Jiang, Qi-rong; Sun, Shou-xin

82

The time-domain characteristics of a traveling-wave linear antenna with linear and nonlinear parallel loads  

Microsoft Academic Search

The time-domain characteristics of a traveling-wave linear antenna with linear and nonlinear parallel loads are discussed. The fast Fourier transform (FFT) is used to analyze the antenna with a linear parallel load. A numerical time-stepping finite-difference equation method is used to analyze the antenna with a nonlinear parallel load. The nonlinear effect is treated by the Newton-Raphson iteration technique. The

M. Kanda

1980-01-01

83

Direct measurement of the characteristic three-body electron attachment time in the atmospheric air in direct current electric field  

SciTech Connect

We report the results of theoretical and experimental study of the characteristic time for three-body attachment of electrons produced by 100 fs UV laser pulse in the atmosphere air in the external DC electric field ranged from 0.2 to 10 kV/cm.

Shutov, A. V.; Smetanin, I. V.; Ionin, A. A.; Levchenko, A. O.; Seleznev, L. V.; Sinitsyn, D. V.; Ustinovskii, N. N.; Zvorykin, V. D. [P. N. Lebedev Physical Institute, Leninskii Prospect 53, Moscow 119991 (Russian Federation)

2013-07-15

84

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...

85

Nitrifier characteristics in submerged membrane bioreactors under different sludge retention times.  

PubMed

Three submerged membrane bioreactors (MBRs) were operated continuously for 230 days by feeding with synthetic inorganic wastewater (NH(4)(+)-N, 100 mg L(-1)) under different solids retention times (SRTs. M(30d), 30 days; M(90d), 90 days; M(infinite), no sludge purge) to examine the influence of SRT on nitrification performance and microbial characteristics. All the reactors could oxidize NH(4)(+)-N to NO(3)(-)-N effectively without accumulation of NO(2)(-)-N. M(30d) with the shortest SRT showed significantly higher specific ammonium oxidizing rate (SAOR, 0.22 kg NH(4)(+)-N kg(-1) MLSS day(-1)) and specific nitrate forming rate (SNFR, 0.13 kg NO(3)(-)-N kg(-1) MLSS day(-1)) than the other two MBRs (0.12-0.14 kg NO(3)(-)-N kg(-1) MLSS day(-1) and 0.042-0.068kg NO(3)(-)-N kg(-1) MLSS day(-1), respectively). Short SRT led to low extracellular polymeric substances (EPS) concentration and long operating cycle. The nitrite oxidizing bacteria (NOB) ratios by both the fluorescence in situ hybridization (FISH) (3.6% for M(30d) and 2.1-2.2% for M(90d) and M(infinite)) and MPN (1.4 x 10(7)cells g(-1) MLSS for M(30d) and 6.2 x 10(5) and 2.7 x 10(4)cells g(-1) MLSS for M(90d) and M(infinite)) analyses showed that M(30d) favored the accumulation of NOB, which was in accordance with the SNFR result. However, the ammonia oxidizing bacteria (AOB) ratios (3.5%, 3.2% and 4.9% for M(30d), M(90d) and M(infinite)) were not in accordance with the SAOR result. PCR-DGGE, clone library and FISH results showed that the fast-growing Nitrosomonas and Nitrobacter sp. were the dominant AOB and NOB, respectively for M(30d), while considerable slow-growing Nitrosospira and Nitrospira sp. existed in M(infinite), which might be an important reason why M(infinite) had a low SAOR and SNFR. PMID:20227741

Yu, Tao; Qi, Rong; Li, Dong; Zhang, Yu; Yang, Min

2010-05-01

86

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

87

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

PubMed Central

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

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

2013-01-01

88

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

ERIC Educational Resources Information Center

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…

Ryan, Suzanne; Manlove, Jennifer; Franzetta, Kerry

89

Unsupervised identification of damage and load characteristics in time-varying systems  

NASA Astrophysics Data System (ADS)

Parameters identification of nonstationary systems is a very challenging topic that has only recently received critical attention from the research community. Aim of the paper is the structural health monitoring of bridge-like structures excited by a massive moving load, whose characteristics, such as the mass and speed, are unknown, in the presence of a localized damage along the structure. A novel method for the simultaneous identification of both the load characteristics and damage parameters from vibration measurements is proposed: the data processing relies on the ensemble empirical mode decomposition and the normalized Hilbert transform. Neither a priori information about the response of the undamaged structure nor the free decay of the damaged system is required, only a single-point measurement is needed. The empirical instantaneous frequency is firstly employed to estimate the load characteristics; secondly, the effect of the moving mass is filtered from the instantaneous frequency, and then, the damage position is identified. The performance of the technique are studied varying the load characteristics, damage locations, and crack depths. The effect of ambient noise is also taken into account. Numerical experiments show the identification is rather accurate, results are not very sensitive to the crack location and depth, while they are sensibly affected by the speed of the moving load.

Roveri, N.; Carcaterra, A.

2013-12-01

90

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

Microsoft Academic Search

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

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

2006-01-01

91

Effect of blade tenderization and tumbling time on the processing characteristics and tenderness of injected cooked roast beef.  

PubMed

The combined effect of blade tenderization (T, NT) and tumbling time (0, 2, 16 h) on quality characteristics of cooked beef roasts processed with 20 or 40% injection level was investigated. Properties of the beef roasts were determined by measuring processing and textural characteristics (shear force, texture profile analysis). Extended tumbling (to 16 h) favorably affected hydration properties and thermal stability, yielding lower cooking loss and purge and higher WHC for beef roasts. It also decreased shear force and hardness of beef samples by 50-60%, but was unable to increase cohesiveness. Blade tenderization prior to injection generally was found to be beneficial for textural characteristics, tended to improve cook yield, but did not influence other hydration properties. An interaction between tenderization and tumbling was observed for shear force. Blade tenderization decreased shear values by 15-20% for roasts tumbled for 0 or 2 h, but did not improve tenderness with extended tumbling. PMID:22061020

Pietrasik, Z; Shand, P J

2004-04-01

92

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

ERIC Educational Resources Information Center

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

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

2012-01-01

93

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

94

Transmission characteristic improvement of two-channel wavelength division multiplexed solitons by controlling initial time offset  

Microsoft Academic Search

We propose a novel configuration of a 2-channel WDM soliton transmission system which cancels collision-induced frequency shifts at each amplifier. We analyze its transmission characteristic numerically with regard to the varying group velocity dispersion (GVD), and predict that a 100 Gb\\/s×2 system utilizing 51 ps solitons amplified every 25 km maintains a BER of 10-9 over 500 km if GVD

T. Matsuzono; J. Maeda; S. Kogoshi; H. Abe

1996-01-01

95

Lapse time and frequency-dependent attenuation characteristics of coda waves in the Northwestern Himalayas  

Microsoft Academic Search

We analyzed the local earthquakes waveform recorded on a broadband seismic network in the northwestern Himalayan Region to\\u000a compute lapse time and frequency dependence of coda Q (Q\\u000a c). The observed Q\\u000a c values increase with increasing lapse time at all frequency bands. The increase in Q\\u000a c values with lapse time is attributed to an increase in Q\\u000a c

S. Mukhopadhyay; C. Tyagi

2007-01-01

96

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

Microsoft Academic Search

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.

Xiaolei Zhang; Kenneth K. Mei

1988-01-01

97

Aperture synthesis of time-limited X waves and analysis of their propagation characteristics  

E-print Network

January 1998 The feasibility of exciting a localized X-wave pulse from a finite aperture is addressed-energy approximation to an X-wave pulse is explored. The analysis is carried out by using a Gaussian time window wave is compared to that of a quasi-monochromatic signal. It is shown that the finite-time X-wave

Lu, Jian-yu

98

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

E-print Network

utilize daylength to time their seasonal reproductive cycle. Introduction. The importance of the pineal gland in mediating the effects of photoperiod on timing the seasonal reproductive cycle of mammals of the pineal is enforced through its rhythmic secretion of melatonin, a hormone secreted principally at night

Boyer, Edmond

99

Time Course Characteristics of Acute Tolerance Development to Continuously Infused Alfentanil in Rats  

Microsoft Academic Search

The time course of the development of acute tolerance to alfentanil was characterized in rat experiments using various algorithms of continuous infusion of the drug. To maintain analgesia at a constant level (tail compres- sion test), alfentanil use was steadily increased: Time to 50% increase in alfentanil use was 255 ? 98 min with analgesia maintained at a level of

Igor Kissin; Sandra S. Lee; G. Richard Arthur; Edwin L. Bradley

1996-01-01

100

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

Microsoft Academic Search

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

D G Janelle; M F Goodchild; B Klinkenberg

1988-01-01

101

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

PubMed

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

Demirel, S; Kirikçi, K

2009-02-01

102

Investigation of doped calcium aluminosilicate glass: A coupling between thermal-expansion and thermal-diffusion models for assessment of nonradiative relaxation time and characteristic diffusion time  

NASA Astrophysics Data System (ADS)

This paper discusses the use of photoacoustic models to obtain the nonradiative relaxation time (?) and characteristic diffusion time (??) for a sample showing visible absorption bands from fluorescent ion-doped low-silica calcium aluminosilicate glass. Two models allowing phase shift analyses, the thermal-expansion and thermal-diffusion models, are briefly reviewed. These models have limitations when the photoacoustic signal depends on both factors, in a coupling mechanism. An alternative model is proposed to take both thermal expansion and thermal diffusion into account with a single temperature solution for the heat-coupled differential equation. This model is simulated for absorbing samples near the thermally thick region. The model is applied to Eu-V codoped glass showing intermediate signal dependence from ?-1.0 to ?-3/2. The nonradiative time and characteristic diffusion time are derived with 33

Souza Filho, N. E.; Nogueira, A. C.; Rohling, J. H.; Baesso, M. L.; Medina, A. N.; Siqueira, A. P. L.; Sampaio, J. A.; Vargas, H.; Bento, A. C.

2009-11-01

103

Time and Difficulty with Tasks and Illness Characteristics Among Caregivers of Individuals Receiving Daily Home Hemodialysis  

E-print Network

Receiving Daily Home Hemodialysis Hannah B. Henderson, Janet L. Welch Indiana University School of Nursing hemodialysis (HHD). Examining relationships between caregivers age, caregiver income, length of time, strategies, and advice of daily home hemodialysis caregivers. Participants included 16 caregivers, recruited

Zhou, Yaoqi

104

Time-varying characteristics of cross-market linkages with empirical application to Gulf stock markets  

Microsoft Academic Search

Purpose – The purpose of this paper is to propose an empirical procedure for examining the time-varying features of cross-market correlations in selected Gulf stock markets. Design\\/methodology\\/approach – The paper directly infers the cross-market linkages from the stock data using a multivariate dynamic conditional correlation GARCH model (DCC-GARCH). The paper attempts to date the structural breaks in the time-paths of

Mohamed El Hedi Arouri; Duc Khuong Nguyen

2010-01-01

105

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

SciTech Connect

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.

Rondorf, Dennis W.; Beeman, John W.; Free, Mary E. (Seattle National Fishery Research Center, Columbia River Field Station, Cook, WA)

1988-06-01

106

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

107

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

SciTech Connect

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

Kwok, K.S.

1993-11-12

108

BLAST Training: Estimating Channel Characteristics for High Capacity Space-Time Wireless  

Microsoft Academic Search

BLAST (Bell Labs Layered Space-Time) is a multiple-antenna communicationscheme whose outage capacity in a Rayleigh flat fading environment grows linearlywith the minimum of the number of transmit and receive antennas, with no increasein bandwidth or transmitted power. Based on its knowledge of the matrix ofpropagation coefficients, the receiver performs two critical operations: nulling andcancellation, that in effect create independent virtual

Thomas L. Marzetta

1999-01-01

109

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

NASA Astrophysics Data System (ADS)

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.

Pankavich, S.; Ortoleva, P.

2010-06-01

110

Search for characteristic features of low-energy quiet-time H, He and heavy nuclei fluxes, 1973-1977  

NASA Technical Reports Server (NTRS)

Results of a survey of the 0.5-10 MeV/nucleon fluxes of H, He and heavier ions during interplanetary 'quiet-times' over the period 1973-1977 using the ULET telescope on IMP-8 are reported. It is found that in this energy range no characteristic flux level, or, e.g., proton/alpha ratio emerges during quiet periods in any year, thus precluding systematic long-term studies of the time behavior of the quiet-time component at these energies. Spectra for a uniquely quiet period in May 1977 and a less restrictively chosen set of quiet periods in 1976-1977 are presented and compared with previous results.

Mason, G. M.; Gloeckler, G.; Hovestadt, D.

1980-01-01

111

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

112

DNS of laminar/turbulent boundary layer transition induced by solid obstacles  

NASA Astrophysics Data System (ADS)

Direct numerical simulation is used to investigate how boundary layer transition is affected by the shape and size of an isolated obstacle whose size is of the order of the boundary layer thickness. The Navier-Stokes equations are discretized by means of an energy-conserving second-order staggered finite-difference method, and the geometrical complexity associated with the obstacle is handled through the immersed-boundary technique. A series of simulations have been performed by varying: i) the obstacle shape (cylinders and prisms with rectangular and triangular base); ii) the roughness height (as a fraction of the boundary layer thickness); iii) the width of the obstacle; iv) the Reynolds number of the incoming boundary layer. We have monitored the vorticity dynamics of the structures which are shed past the obstacle, and observed the concurrence of two mechanisms which promote transition to turbulence, namely the unsteady shear layer separation at the top edge of the obstacle, and the regeneration of quasi-streamwise vortices at the sides of the obstacle. The validity of semi-empirical transition criteria based on a suitably defined roughness Reynolds number will also be discussed, and associated with the physical mechanisms responsible for the self-sustainment of the disturbances.

Orlandi, Paolo; Bernardini, Matteo; Pirozzoli, Sergio

2011-11-01

113

Laminar, turbulent, and inertial shear-thickening regimes in channel flow of neutrally buoyant particle suspensions.  

PubMed

The aim of this Letter is to characterize the flow regimes of suspensions of finite-size rigid particles in a viscous fluid at finite inertia. We explore the system behavior as a function of the particle volume fraction and the Reynolds number (the ratio of flow and particle inertia to viscous forces). Unlike single-phase flows, where a clear distinction exists between the laminar and the turbulent states, three different regimes can be identified in the presence of a particulate phase, with smooth transitions between them. At low volume fractions, the flow becomes turbulent when increasing the Reynolds number, transitioning from the laminar regime dominated by viscous forces to the turbulent regime characterized by enhanced momentum transport by turbulent eddies. At larger volume fractions, we identify a new regime characterized by an even larger increase of the wall friction. The wall friction increases with the Reynolds number (inertial effects) while the turbulent transport is weakly affected, as in a state of intense inertial shear thickening. This state may prevent the transition to a fully turbulent regime at arbitrary high speed of the flow. PMID:25554885

Lashgari, Iman; Picano, Francesco; Breugem, Wim-Paul; Brandt, Luca

2014-12-19

114

Laminar Turbulent Transition in a Boundary Layer Subjected to Weak Free Stream Turbulence  

NASA Astrophysics Data System (ADS)

For revealing the transition process in a flat plate boundary layer subjected to a weak free stream turbulence, flow visualization and hot-wire measurements were performed. A weak free stream turbulence was generated by a turbulence grid mounted upstream of the contraction. The flow visualization clearly displayed a transition scenario in which a local two-dimensional wave packet rapidly forms a ? shape structure and then breaks down to turbulence, resulting in the generation of a turbulent spot. Quantitative measurements performed by using a hot-wire anemometer also confirmed the existence of local Tollmien-Schlichting waves that agreed with the parallel linear theory in terms of their frequency, phase velocity, and the wall-normal distribution of band-pass-filtered fluctuations. For comparison, a boundary layer subjected to a moderate-intensity free stream turbulence was investigated. This investigation showed that streaky structures play an important role in the boundary layer transition, as shown by Matsubara et al. [J. Fluid Mech., 430, (2001), 149-168.] A drastic change occurred in the transition process and this change could be sensitively determined by employing the intensity and/or spectra of the free stream turbulence.

Kenchi, Toshiaki; Matsubara, Masaharu; Ikeda, Toshihiko

115

Laminar-Turbulent Transition: The Change of the Flow State Temperature with the Reynolds Number  

NASA Astrophysics Data System (ADS)

Representing the fluid flow as a collection of coherent structures of various size, the statistical temperature of the flow state is determined as a function of the Reynolds number. It is shown that at small Reynolds numbers, associated with laminar states, the temperature is positive, while at large Reynolds numbers, associated with turbulent states, it is negative. At intermediate Reynolds numbers, the temperature changes from positive to negative as the size of the coherent structures increases, similar to what was predicted by Onsager for a system of parallel point-vortices in an inviscid fluid. It is also shown that in the range of intermediate Reynolds numbers the temperature exhibits a critical divergence.

Chekmarev, Sergei F.

2014-12-01

116

Laminar-turbulent transition calculations of heat transfer at hypersonic Mach numbers over sharp cones  

NASA Technical Reports Server (NTRS)

Computations of the hypersonic flow around sharp cones were carried out using the PNS code with attention given to the heat transfer predictions around the transition region. Results of calculations performed over 5, 8, and 10 deg half-angle sharp cones in the Mach number range of 7 to 10 are presented. It is noted that calculations of this type have become an integral part of the general design procedure for hypersonic vehicles such as the National Aerospace Plane and the Space Shuttle.

Kaul, U. K.

1988-01-01

117

Laminar, Turbulent, and Inertial Shear-Thickening Regimes in Channel Flow of Neutrally Buoyant Particle Suspensions  

NASA Astrophysics Data System (ADS)

The aim of this Letter is to characterize the flow regimes of suspensions of finite-size rigid particles in a viscous fluid at finite inertia. We explore the system behavior as a function of the particle volume fraction and the Reynolds number (the ratio of flow and particle inertia to viscous forces). Unlike single-phase flows, where a clear distinction exists between the laminar and the turbulent states, three different regimes can be identified in the presence of a particulate phase, with smooth transitions between them. At low volume fractions, the flow becomes turbulent when increasing the Reynolds number, transitioning from the laminar regime dominated by viscous forces to the turbulent regime characterized by enhanced momentum transport by turbulent eddies. At larger volume fractions, we identify a new regime characterized by an even larger increase of the wall friction. The wall friction increases with the Reynolds number (inertial effects) while the turbulent transport is weakly affected, as in a state of intense inertial shear thickening. This state may prevent the transition to a fully turbulent regime at arbitrary high speed of the flow.

Lashgari, Iman; Picano, Francesco; Breugem, Wim-Paul; Brandt, Luca

2014-12-01

118

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

PubMed

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

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

2011-12-01

119

Regional tendencies of extreme wind characteristics from measured, reanalysis and simulated time series over Hungary  

NASA Astrophysics Data System (ADS)

It is widely known that changing global climate may trigger a disproportionate response in extremes. Therefore, it is a key issue to understand climate variability and climate change and analyze observed extreme events that could link to changing regional climate. Nowadays, there is a great interest to document and evaluate the extremes of near-surface wind that could assist in estimating the regional effects of climate change in Hungary. Our study, focused on observed wind speed and wind gust values, is based on 36-year-long (1975-2010) wind data set of 36 Hungarian synoptic meteorological stations. Complex analysis of wind climate was carried out, spatial and temporal (monthly and seasonal) distributions of mean and extreme wind characteristics were estimated. Measured and ERA Interim reanalysis data (1997-2010) were compared in order to prove the adaptability of contemporary climate simulation results in estimation of regional climate change effects. Finally, monthly and seasonal wind field projections of ECHAM regional climate model were mapped and analyzed (2021-2050 and 2071-2100) for the Carpathian Basin.

Péliné, Cs. N.; Radics, K.; Bartholy, J.

2012-04-01

120

Spectral characteristics of time-dependent orbit errors in altimeter height measurements  

NASA Technical Reports Server (NTRS)

A mean reference surface and time-dependent orbit errors are estimated simultaneously for each exact-repeat ground track from the first two years of Geosat sea level estimates based on the Goddard Earth model (GEM)-T2 orbits. Motivated by orbit theory and empirical analysis of Geosat data, the time-dependent orbit errors are modeled as 1 cycle per revolution (cpr) sinusoids with slowly varying amplitude and phase. The method recovers the known 'bow tie effect' introduced by the existence of force model errors within the precision orbit determination (POD) procedure used to generate the GEM-T2 orbits. The bow tie pattern of 1-cpr orbit errors is characterized by small amplitudes near the middle and larger amplitudes (up to 160 cm in the 2 yr of data considered here) near the ends of each 5- to 6-day orbit arc over which the POD force model is integrated. A detailed examination of these bow tie patterns reveals the existence of daily modulations of the amplitudes of the 1-cpr sinusoid orbit errors with typical and maximum peak-to-peak ranges of about 14 cm and 30 cm, respectively. The method also identifies a daily variation in the mean orbit error with typical and maximum peak-to-peak ranges of about 6 and 30 cm, respectively, that is unrelated to the predominant 1-cpr orbit error. Application of the simultaneous solution method to the much less accurate Geosat height estimates based on the Naval Astronautics Group orbits concludes that the accuracy of POD is not important for collinear altimetric studies of time-dependent mesoscale variability (wavelengths shorter than 1000 km), as long as the time-dependent orbit errors are dominated by 1-cpr variability and a long-arc (several orbital periods) orbit error estimation scheme such as that presented here is used.

Chelton, Dudley B.; Schlax, Michael G.

1993-01-01

121

The effects of corridor characteristics on motorists' decisions to divert in resonse to time saving messages  

E-print Network

OP FIGURES Page Study Area, Central Section of the North Central Expressway Corridor 14 Southbound Travel Times on North Central Expressway from Lyndon B. Johnson Freeway Exit to the Central Business District . 29 Percentage of Diversion... agencies and jurisdictions. ATMS also provides the necessary infrastructure for all IVHS cotnponents such as the communication network, control center hardware and software, and operation and maintenance activities. Advanced Traveler Information Systems...

Robbins, Charles John

1993-01-01

122

Spectral characteristics of time-dependent orbit errors in altimeter height measurements  

NASA Astrophysics Data System (ADS)

A mean reference surface and time-dependent orbit errors are estimated simultaneously for each exact-repeat ground track from the first two years of Geosat sea level estimates based on the Goddard Earth model (GEM)-T2 orbits. Motivated by orbit theory and empirical analysis of Geosat data, the time-dependent orbit errors are modeled as 1 cycle per revolution (cpr) sinusoids with slowly varying amplitude and phase. The method recovers the known 'bow tie effect' introduced by the existence of force model errors within the precision orbit determination (POD) procedure used to generate the GEM-T2 orbits. The bow tie pattern of 1-cpr orbit errors is characterized by small amplitudes near the middle and larger amplitudes (up to 160 cm in the 2 yr of data considered here) near the ends of each 5- to 6-day orbit arc over which the POD force model is integrated. A detailed examination of these bow tie patterns reveals the existence of daily modulations of the amplitudes of the 1-cpr sinusoid orbit errors with typical and maximum peak-to-peak ranges of about 14 cm and 30 cm, respectively. The method also identifies a daily variation in the mean orbit error with typical and maximum peak-to-peak ranges of about 6 and 30 cm, respectively, that is unrelated to the predominant 1-cpr orbit error. Application of the simultaneous solution method to the much less accurate Geosat height estimates based on the Naval Astronautics Group orbits concludes that the accuracy of POD is not important for collinear altimetric studies of time-dependent mesoscale variability (wavelengths shorter than 1000 km), as long as the time-dependent orbit errors are dominated by 1-cpr variability and a long-arc (several orbital periods) orbit error estimation scheme such as that presented here is used.

Chelton, Dudley B.; Schlax, Michael G.

1993-07-01

123

The Real Time Diagnostics of Combustion Characteristics of Solid Propellant by Remote Sensing FTIR System  

Microsoft Academic Search

The flame infrared emission spectra between 4700 and 800 cm of nitroguanidine solid propellant combustion were recorded using a real time, remote sensing Fourier transform infrared (FTIR) spectrometer with a spectral resolution of 2 cm. The combustion flame temperature of this high intensity IR propellant combustion was studied via the fine structure of the rotational vibrational emission bands of HF (4400?3950 cm) and

Yan Li; Junde Wang

2003-01-01

124

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

125

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

PubMed

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

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

2014-01-01

126

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

PubMed Central

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

2014-01-01

127

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

NASA Astrophysics Data System (ADS)

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.

Du, Yong; Liu, Jianjun; Hong, Zhi

2013-08-01

128

Fall detection and classifications based on time-scale radar signal characteristics  

NASA Astrophysics Data System (ADS)

Unattended catastrophic falls result in risk to the lives of elderly. There are growing efforts and rising interest in detecting falls of the aging population, especially those living alone. Radar serves as an effective non-intrusive sensor for detecting human activities. For radar to be effective, it is important to achieve low false alarms, i.e., the system can reliably differentiate between a fall and other human activities. In this paper, we discuss the time-scale based signal analysis of the radar returns from a human target. Reliable features are extracted from the scalogram and are used for fall classifications. The classification results and the advantages of using a wavelet transform are discussed.

Gadde, Ajay; Amin, Moeness G.; Zhang, Yimin D.; Ahmad, Fauzia

2014-05-01

129

Space-time characteristics of radiation of single-mode injection lasers  

SciTech Connect

The space-time nonuniformity of the emission of injection lasers operating in the fundamental transverse mode and having emission-region lengths less than 10 microns is investigated experimentally using the techniques described by Koval et al. (1981). The devices analyzed are GaAs/GaAlAs transverse p-n-junction or mesa-stripe-contact injection lasers with cavity lengths 200-250 microns and threshold currents 30-35 and 45-60 mA, respectively. The results are presented in graphs and discussed. It is found that the divergence of the laser light near the threshold can be determined by combining the directional patterns of the spontaneous and stimulated emissions. T.K.(IAA)

Borodulin, V.I.; Zverkov, M.V.; Konyayev, V.P.; Lamanov, A.L.; Pashko, S.A.; Trapeznikov, M.B.; Shveykin, V.I.

1984-08-01

130

Conformational characteristics of chiral and racemic naproxen molecules investigated by terahertz time-domain spectroscopy  

NASA Astrophysics Data System (ADS)

Absorption spectra in the terahertz region between 6 and 66 cm-1 (0.2 ~ 2.0 THz) were measured for S-(+)-, R-(-) and RS-naproxen pharmaceutical molecules in crystalline form using time-domain terahertz spectroscopic (THz-TDS) technique at room temperature. Different absorption features were observed for the racemic RS-naproxen and its corresponding enantiomers (S-(+)- and R-(-)-naproxen). The observed THz absorption bands are strikingly sensitive to the change of subtle conformational structures despite that the isostructurality exists within such crystal molecules. The results show that the THz-TDS technique can be definitely used for distinguishing between chiral and racemic compounds in pharmaceutical and biological fields.

Du, Yong; Zhao, Rongjiao; Hao, Guohui; Guo, Changsheng; Hong, Zhi

2011-11-01

131

Conformational characteristics of chiral and racemic naproxen molecules investigated by terahertz time-domain spectroscopy  

NASA Astrophysics Data System (ADS)

Absorption spectra in the terahertz region between 6 and 66 cm-1 (0.2 ~ 2.0 THz) were measured for S-(+)-, R-(-) and RS-naproxen pharmaceutical molecules in crystalline form using time-domain terahertz spectroscopic (THz-TDS) technique at room temperature. Different absorption features were observed for the racemic RS-naproxen and its corresponding enantiomers (S-(+)- and R-(-)-naproxen). The observed THz absorption bands are strikingly sensitive to the change of subtle conformational structures despite that the isostructurality exists within such crystal molecules. The results show that the THz-TDS technique can be definitely used for distinguishing between chiral and racemic compounds in pharmaceutical and biological fields.

Du, Yong; Zhao, Rongjiao; Hao, Guohui; Guo, Changsheng; Hong, Zhi

2012-03-01

132

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

PubMed

The effect of bentonite waste added to a "poor" soil on its general characteristic and copper adsorption capacity was assessed. The soil was amended with different bentonite waste concentrations (0, 10, 20, 40 and 80 Mg ha(-1)) in laboratory pots, and different times of incubation of samples were tested (one day and one, four and eight months). The addition of bentonite waste increased the pH, organic matter content and phosphorus and potassium concentrations in the soil, being stable for P and K, whereas the organic matter decreased with time. Additionally, the copper sorption capacity of the soil and the energy of the Cu bonds increased with bentonite waste additions. However, the use of this type of waste in soil presented important drawbacks for waste dosages higher than 20 Mg ha(-1), such as an excessive increase of the soil pH and an increase of copper in the soil solution. PMID:25560662

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

2015-03-01

133

Relating low-flow characteristics to the base flow recession time constant at partial record stream gauges  

USGS Publications Warehouse

Base flow recession information is helpful for regional estimation of low-flow characteristics. However, analyses that exploit such information generally require a continuous record of streamflow at the estimation site to characterize base flow recession. Here we propose a simple method for characterizing base flow recession at low-flow partial record stream gauges (i.e., sites with very few streamflow measurements under low-streamflow conditions), and we use that characterization as the basis for a practical new approach to low-flow regression. In a case study the introduction of a base flow recession time constant, estimated from a single pair of strategically timed streamflow measurements, approximately halves the root-mean-square estimation error relative to that of a conventional drainage area regression. Additional streamflow measurements can be used to reduce the error further.

Eng, K.; Milly, P.C.D.

2007-01-01

134

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

135

Trap densities and transport properties of pentacene metal-oxide-semiconductor transistors. I. Analytical modeling of time-dependent characteristics  

NASA Astrophysics Data System (ADS)

Metal-oxide-semiconductor (MOS) transistors fabricated with pentacene thin films were characterized by temperature-dependent current-voltage (I-V) characteristics, time-dependent current measurements, and admittance spectroscopy. The channel mobility shows almost linear variation with temperature, suggesting that only shallow traps are present in the semiconductor and at the oxide/semiconductor interface. The admittance spectra feature a broad peak, which can be modeled as the sum of a continuous distribution of relaxation times. The activation energy of this peak is comparable to the polaron binding energy in pentacene. The absence of trap signals in the admittance spectra confirmed that both the semiconductor and the oxide/semiconductor interface have negligible density of deep traps, likely owing to the passivation of SiO2 before pentacene growth. Nevertheless, current instabilities were observed in time-dependent current measurements following the application of gate-voltage pulses. The corresponding activation energy matches the energy of a hole trap in SiO2. We show that hole trapping in the oxide can explain both the temperature and the time dependences of the current instabilities observed in pentacene MOS transistors. The combination of these experimental techniques allows us to derive a comprehensive model for charge transport in hybrid architectures where trapping processes occur at various time and length scales.

Basile, A. F.; Cramer, T.; Kyndiah, A.; Biscarini, F.; Fraboni, B.

2014-06-01

136

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

SciTech Connect

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.

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

137

Space-time characteristics of earthquake sources in various tectonic environments  

NASA Astrophysics Data System (ADS)

Earthquake hazards are difficult to accurately evaluate along slow plate boundaries and in plate interiors because the locations of recorded earthquakes appear to have a higher probability of earthquakes than locations where none have been recorded. In these regions, a non-uniform earthquake hazard is often assumed. Assuming that the hazard is uniform, earthquake simulations created synthetic earthquake records with an average time between earthquakes. The results showed that non-uniform hazard cannot be assumed when the earthquake record is short. Giant earthquakes (Mw>8.5) extend earthquake destruction from a regional hazard to a global hazard by creating a tsunami. Giant earthquakes occur at subduction zones but have not been recorded along all subduction zones. Ruff and Kanamori (1980) showed the subduction zone convergence rate and lithosphere age need to be fast and young, respectively, to create giant earthquakes. To examine the relationship using recent data, the thermal parameter (?), defined as the produce of the convergence rate and the lithospheric age, was compared with the largest earthquake magnitude recorded along each subduction zone. There was no correlation between the thermal parameter and the magnitude. Hence, the convergence rate and lithospheric age do not predict which subduction zones can create giant earthquakes. While giant earthquakes are thrust earthquakes, comparing earthquakes with different focal mechanisms can increase understanding of earthquakes themselves. To examine how earthquake stress drops varies with focal mechanism and tectonic environment, a relative stress drop was calculated for earthquakes from the observed seismic moment and the source time function duration. Earthquakes with different focal mechanisms and tectonic environments did not show significant differences in stress drop. It is not known why these results did not duplicate previously published results, which showed different stress drops for different focal mechanisms (Stein and Pelayo, 1991). Focal mechanisms also yield stress directions but may not be precisely calculated. The resolution of focal mechanisms was tested in Java to study subsurface fracture orientations and stress directions. The P-wave polarities at each station were used to calculate the precision of focal mechanisms. Strike and dip of focal mechanisms were reliably identified from these data, but slip directions were not precisely calculated.

Swafford, Laura C.

138

The relationship between isometric force-time curve characteristics and club head speed in recreational golfers.  

PubMed

The primary purpose of the present investigation was to examine the relationships between club head speed, isometric midthigh pull performance, and vertical jump performance in a cohort of recreational golfers. Twelve recreational golfers (age, 20.4 ± 1.0 years; weight, 77.0 ± 9.8 kg; height, 177.8 ± 6.3 cm; body fat, 17.1 ± 7.6%; handicap, 14.5 ± 7.3; experience, 8.9 ± 3.6 years) completed 3 testing sessions: (a) familiarization session and body composition measurements; (b) measurement of force-time curves in the isometric midthigh pull, countermovement, and static vertical jump (SJ); and (c) measurement of club head speed. During sessions 1 and 2, subjects performed 5 countermovement jumps, 5 SJ, and 2 isometric midthigh pulls. Isometric peak force was measured at 30, 50, 90, 100, 200, and 250 milliseconds. Rate of force development was measured among 0-30, 0-50, 0-90, 0-100, 0-200, and 0-250 milliseconds. Peak rate of force development was determined as the highest value in a 10-millisecond sampling windows. During session 3, subjects performed 10 maximal golf swings with a driver to measure club head speed; peak and average club head speed were analyzed across the 10 swings. Golf handicap was moderately correlated with average (r = -0.52, p = 0.04) and maximal club head speed (r = -0.45, p = 0.07). Force at 150 milliseconds during the isomeric midthigh pull test was moderately correlated with average (r = 0.46, p = 0.07) and maximal club head speed (r = 0.47, p = 0.06). Moderate correlations were also found between the rate of force development from 0 to 150 milliseconds and average (r = 0.38, p = 0.11) and maximal club head speed (r = 0.36, p = 0.12). The present findings suggest that the ability to exhibit high ground reaction forces in time frames <200 milliseconds are related to high club head speeds. PMID:22797001

Leary, Brian K; Statler, Jason; Hopkins, Britton; Fitzwater, Rachael; Kesling, Tucker; Lyon, Jacob; Phillips, Brett; Bryner, Randall W; Cormie, Prue; Haff, G Gregory

2012-10-01

139

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

NASA Astrophysics Data System (ADS)

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.

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

2011-07-01

140

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

PubMed

Storage conditions are important factors for jam quality. The objective of this study was to monitor the physicochemical stability and sensorial profile of apricot jam during storage for 60 days at 5 °C, 25 °C and 37 °C. For that purpose, special attention was paid to total soluble solids (TSS), titratable acidity (TA), colour, free amino acids (FAA), total sugars (TS) and hydroxymethylfurfural (HMF). The decreasing parameter for jam at the end of storage under 5 °C, 25 °C and 37 °C, respectively, were 16.81%, 34.30% and 56.01% for FAA, and 5.52%, 9.02% and 7.46% for TS; likewise, the increasing were 19.81%, 22.94% and 25.07% for TA, 3.15%, 4.08% and 4.47% for TSS, 15.96%, 112.76% and 150% for HMF. Jam stability was better at 5 °C than 25 °C and 37 °C. The interaction time-temperature factor had significant effects on pH, TS, FAA and HMF, unlike TA, TSS and sensorial profile. PMID:24128444

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

2014-02-15

141

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

NASA Astrophysics Data System (ADS)

A vast amount of oil sands exists in the Athabasca area, Alberta, Canada. These oil sands consist of bitumen (extra-heavy oil) and unconsolidated sand distributed from surface to a depth of 750 meters. Including conventional crude oil, the total number of proved remaining oil reserves in Canada ranks second place in the world after Saudi Arabia. For the production of bitumen from the reservoir 200 to 500 meters in depth, the Steam Assisted Gravity Drainage (SAGD) method (Steam Injection EOR) has been adopted as bitumen is not movable at original temperatures. It is essential to understand the detailed reservoir distribution and steam chamber development extent for optimizing the field development. Oil sands reservoir characterization is conducted using 3D seismic data acquired in February 2002. Conducting acoustic impedance inversion to improve resolution and subsequent multi-attribute analysis integrating seismic data with well data facilitates an understanding of the detailed reservoir distribution. These analyses enable the basement shale to be imaged, and enables identification to a certain degree of thin shale within the reservoir. Top and bottom depths of the reservoir are estimated in the range of 2.0 meters near the existing wells even in such a complex channel sands environment characterized by abrupt lateral sedimentary facies changes. In March 2006, monitoring 3D seismic data was acquired to delineate steam-affected areas. The 2002 baseline data is used as a reference data and the 2006 monitoring data is calibrated to the 2002 seismic data. Apparent differences in the two 3D seismic data sets with the exception of production related response changes are removed during the calibration process. P-wave and S-wave velocities of oil sands core samples are also measured with various pressures and temperatures, and the laboratory measurement results are then combined to construct a rock physics model used to predict velocity changes induced by steam-injection. The differences of the seismic responses between the time-lapse seismic volumes can be quantitatively explained by P-wave velocity decrease of the oil sands layers due to steam-injection. In addition, the data suggests that a larger area would be influenced by pressure than temperature. We calculate several seismic attributes such as RMS values of amplitude difference, maximum cross correlations, and interval velocity differences. These attributes are integrated by using self-organization maps (SOM) and K-means methods. By this analysis, we are able to distinguish areas of steam chamber growth from transitional and non-affected areas. In addition, 3D P-SV converted-wave processing and analysis are applied on the second 3D data set (recorded with three-component digital sensor). Low Vp/Vs values in the P-SV volume show areas of steam chamber development, and high Vp/Vs values indicate transitional zones. Our analysis of both time-lapse 3D seismic and 3D P-SV data along with the rock physics model can be used to monitor qualitatively and quantitatively the rock property changes of the inter-well reservoir sands in the field.

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

2008-12-01

142

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

Microsoft Academic Search

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

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

1982-01-01

143

Effect of the composition of film-forming solutions and the temperature and time regimes on the colorimetric characteristics of film coatings  

SciTech Connect

The calorimetric characteristics of film coatings obtained from iron-containing industrial waste are determined by instrumental methods. The relationship between the composition of the film-forming solution, the temperature and time regimes of treatment and the calorimetric characteristics of film coatings such as lightness, brightness, and intensity (purity) of hue is described.

Sytnik, R.D.; Kiuila, I.G.; Ignatyuk, O.A. [Kharkov State Polytechnical Univ., Kharkov (Ukraine)

1995-11-01

144

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

PubMed Central

[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.

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

2015-01-01

145

A bottom-up approach: using residence time distributions and characteristic biogeochemical timescales to upscale multiphysics models of hyporheic exchange  

NASA Astrophysics Data System (ADS)

Residence time distributions (RTDs) and characteristic biogeochemical time scales (CBTSs) are integrated metrics that can be used to describe the biogeochemical evolution of water within hydrologic systems. RTDs describe the time that water and solutes are in contact with the system and strongly depend on the forcing and geomorphic features driving exchange and the system's hydraulic properties. On the other hand, CBTSs describe the time necessary for a biogeochemical transformation to take place and depend on the reaction type, solute concentrations entering the system, and chemical kinetics (or thermodynamics). Comparing RTDs and CBTSs allow us to evaluate the potential for transformation within the hydrologic system. In this work, we illustrate this approach with sinuosity-driven hyporheic zones; however, these concepts can be applied to other hydrologic systems. A two-dimensional, transient, numerical flow and transport model is used to illustrate the effect that dynamics, caused by deterministically generated flood events, has on flow fields and RTDs, and therefore on the character of the hyporheic zone as a biogeochemical reactor. A simple analytical model is used to estimate the CBTSs associated to the degradation of dissolved organic carbon in these hydrologic systems, which are compared to numerically-modeled RTDs and used to estimate the biogeochemical zonation within the HZ and its net biogeochemical response. Additionally, we use a multispecies, reactive transport model to assess this approach, paying special attention to those portions of the system with intermittent hyporheic contributions. In particular, transient flow results in time-varying hot-spot for biogeochemical reactions and induces the emergence of new modes on the dynamic RTDs, which are observed within the system and at the outlet. This parsimonious approach can be used as a predictive tool to quantify the potential of meanders as biogeochemical reactors at the watershed scale with the aid of historic discharge data, remote sensing data, and GIS processing techniques.

Gomez, Jesus D.; Wilson, John L.

2013-04-01

146

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

NASA Astrophysics Data System (ADS)

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.

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

147

Time-Varying Characteristics Analysis and Fuzzy Controller Systematic Design Method for Pressurized Water Reactor Power Control  

SciTech Connect

In this paper a systematic design method of fuzzy control systems is applied to the pressurized water reactor's (PWR) power control. The paper includes three parts. In the first part, a simplified time-varying linear model of the PWR power system is constructed, and its inner structure and time-varying characteristics are analyzed. That provides a solid basis for study and design of the nuclear reactor power control system. In the second part, a systematic design method of fuzzy control systems is introduced and applied to control the nuclear reactor power process. The design procedures and parameters are given in detail. This systematic design method has some notable advantages. The control of a global fuzzy model can be decomposed into controlling a set of linear submodels. Each submodel controller can be independently designed by using a linear quadratic regulator approach. This systematic design method gives a sufficient and necessary condition to guarantee the stability of fuzzy control systems; thus, better control performance can be obtained due to the accurate control gains. In the third part, the control performance of the nuclear reactor fuzzy control system is examined by simulation experiments, including nuclear reactor power shutdown, start-up, and adjustment operations. The satisfactory experiment results have shown that the systematic design method for fuzzy control systems is effective and feasible.

Liu Shengzhi; Zhang Naiyao; Cui Zhenhua [Tsinghua University (China)

2004-11-15

148

Investigating the spectral characteristics of backscattering from heterogeneous spherical nuclei using broadband finite-difference time-domain simulations  

NASA Astrophysics Data System (ADS)

Reflectance spectra measured from epithelial tissue have been used to extract size distribution and refractive index of cell nuclei for noninvasive detection of precancerous changes. Despite many in vitro and in vivo experimental results, the underlying mechanism of sizing nuclei based on modeling nuclei as homogeneous spheres and fitting the measured data with Mie theory has not been fully explored. We describe the implementation of a three-dimensional finite-difference time-domain (FDTD) simulation tool using a Gaussian pulse as the light source to investigate the wavelength-dependent characteristics of backscattered light from a nuclear model consisting of a nucleolus and clumps of chromatin embedded in homogeneous nucleoplasm. The results show that small-sized heterogeneities within the nuclei generate about five times higher backscattering than homogeneous spheres. More interestingly, backscattering spectra from heterogeneous spherical nuclei show periodic oscillations similar to those from homogeneous spheres, leading to high accuracy of estimating the nuclear diameter by comparison with Mie theory. In addition to the application in light scattering spectroscopy, the reported FDTD method could be adapted to study the relations between measured spectral data and nuclear structures in other optical imaging and spectroscopic techniques for in vivo diagnosis.

Chao, Guo-Shan; Sung, Kung-Bin

2010-01-01

149

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

NASA Astrophysics Data System (ADS)

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.

Guerra, Melania

150

Performance Characteristics and Comparison of Abbott and artus Real-Time Systems for Hepatitis B Virus DNA Quantification ?  

PubMed Central

Virological monitoring of hepatitis B virus (HBV) DNA is critical to the management of HBV infection. With several HBV DNA quantification assays available, it is important to use the most efficient testing system for virological monitoring. In this study, we evaluated the performance characteristics and comparability of three HBV DNA quantification systems: Abbott HBV real-time PCR (Abbott PCR), artus HBV real-time PCR with QIAamp DNA blood kit purification (artus-DB), and artus HBV real-time PCR with the QIAamp DSP virus kit purification (artus-DSP). The lower limits of detection of these systems were established against the WHO international standards for HBV DNA and were found to be 1.43, 82, and 9 IU/ml, respectively. The intra-assay and interassay coefficients of variation of plasma samples (1 to 6 log10 IU/ml) ranged between 0.05 to 8.34% and 0.16 to 3.48% for the Abbott PCR, 1.53 to 26.85% and 0.50 to 12.89% for artus-DB, and 0.29 to 7.42% and 0.94 to 3.01% for artus-DSP, respectively. Ninety HBV clinical samples were used for comparison of assays, and paired quantitative results showed strong correlation by linear regression analysis (artus-DB with Abbott PCR, r = 0.95; Abbott PCR with artus-DSP, r = 0.97; and artus-DSP with artus-DB, r = 0.94). Bland-Altman analysis showed a good level of agreement for Abbott PCR and artus-DSP, with a mean difference of 0.10 log10 IU/ml and limits of agreement of ?0.91 to 1.11 log10 IU/ml. No genotype-specific bias was seen in all three systems for HBV genotypes A, C, and D, which are predominant in this region. This finding illustrates that the Abbott real-time HBV and artus-DSP systems show more comparable performance than the artus-DB system, meeting the current guidelines for assays to be used in the management of hepatitis B. PMID:21795507

Ismail, Ashrafali M.; Sivakumar, Jayashree; Anantharam, Raghavendran; Dayalan, Sujitha; Samuel, Prasanna; Fletcher, Gnanadurai J.; Gnanamony, Manu; Abraham, Priya

2011-01-01

151

Comparing single vehicle and multivehicle fatal road crashes: a joint analysis of road conditions, time variables and driver characteristics.  

PubMed

The difference between single vehicle crashes and multivehicle crashes was investigated in a collection of fatal crashes from six European countries. Variables with respect to road conditions, time variables, and participant characteristics were studied separately at first and then jointly in a logistic multiple regression model allowing to weigh different accounts of single vehicle as opposed to multivehicle crash occurrence. The most important variables to differentiate between single and multivehicle crashes were traffic flow, the presence of a junction and the presence of a physical division between carriageways. Heavy good vehicles and motorcycles were less likely to be involved in single vehicle crashes than cars. Moreover crashes of impaired drivers with more passengers were more likely to be single vehicle crashes than those of other drivers. Young drivers, rural roads, nights and weekends were all shown to have a higher proportion of single vehicle crashes but in the multivariate analysis these effects were demonstrated to be mediated by the road conditions named above. PMID:23622842

Martensen, Heike; Dupont, Emmanuelle

2013-11-01

152

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

PubMed

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

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

2012-09-01

153

Investigating the spectral characteristics of backscattering from heterogeneous spheroidal nuclei using broadband finite-difference time-domain simulations  

NASA Astrophysics Data System (ADS)

Backscattered light spectra have been used to extract size distribution of cell nuclei in epithelial tissues for noninvasive detection of precancerous lesions. In existing experimental studies, size estimation is achieved by assuming nuclei as homogeneous spheres or spheroids and fitting the measured data with models based on Mie theory. However, the validity of simplifying nuclei as homogeneous spheres has not been thoroughly examined. In this study, we investigate the spectral characteristics of backscattering from models of spheroidal nuclei under plane wave illumination using three-dimensional finite-difference time-domain (FDTD) simulation. A modulated Gaussian pulse is used to obtain wavelength dependent scattering intensity with a single FDTD run. The simulated model of nuclei consists of a nucleolus and randomly distributed chromatin condensation in homogeneous cytoplasm and nucleoplasm. The results show that backscattering spectra from spheroidal nuclei have similar oscillating patterns to those from homogeneous spheres with the diameter equal to the projective length of the spheroidal nucleus along the propagation direction. The strength of backscattering is enhanced in heterogeneous spheroids as compared to homogeneous spheroids. The degree of which backscattering spectra of heterogeneous nuclei deviate from Mie theory is highly dependent on the distribution of chromatin/nucleolus but not sensitive to nucleolar size, refractive index fluctuation or chromatin density.

Chao, Guo-Shan; Sung, Kung-Bin

2010-02-01

154

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

PubMed

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

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

2014-01-16

155

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

PubMed

We examined the frequency of adolescents' use of electronic media (ie, television/movie watching, text messaging, talking on the telephone, listening to music with headphones, and playing with hand-held games) at family meals and examined associations with demographic characteristics, rules about media use, family characteristics, and the types of foods served at meals using an observational, cross-sectional design. Data were drawn from two coordinated, population-based studies of adolescents (Project Eating Among Teens 2010) and their parents (Project Families and Eating Among Teens). Surveys were completed during 2009-2010. Frequent television/movie watching during family meals by youth was reported by 25.5% of parents. Multivariate logistic regression analyses indicated significantly higher odds of mealtime media use (P<0.05) for girls and older teens. In addition, higher odds of mealtime media use (P<0.05) were also seen among those whose parents had low education levels or were black or Asian; having parental rules about media use significantly reduced these odds. Frequent mealtime media use was significantly associated with lower scores on family communication (P<0.05) and scores indicating less importance placed on mealtimes (P<0.001). Furthermore, frequent mealtime media use was associated with lower odds of serving green salad, fruit, vegetables, 100% juice, and milk at meals, whereas higher odds were seen for serving sugar-sweetened beverages (P<0.05). The ubiquitous use of mealtime media by adolescents and differences by sex, race/ethnicity, age, and parental rules suggest that supporting parents in their efforts to initiate and follow-through on setting mealtime media use rules may be an important public health strategy. PMID:24361006

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

2014-07-01

156

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

NASA Astrophysics Data System (ADS)

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.

Khelifa, S.

2014-12-01

157

Statistical characteristics of the electric and magnetic fields and their time derivatives 15 m and 30 m from triggered  

E-print Network

environment, return stroke, statistical characteristics of lightning, electromagnetic fields, ICLRT Citation ground rods). INDEX TERMS: 0619 Electromagnetics: Electromagnetic theory; 0634 Electromagnetics Meteorology and Atmospheric Dynamics: Lightning; KEYWORDS: rocket-triggered lightning, electromagnetic

Florida, University of

158

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

PubMed Central

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

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

159

Simulation of vegetation, soil characteristics, and topography effects on soil water distribution and streamflow timing over a semi-arid mountain catchment  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil water (', m3m-3) and soil characteristics act as intermediaries, along with plants and climate, modifying and modulating streamflow timing and quantity—the majority in the intermountain US west resulting from spring-melt events of accumulated winter snow. The antecedent soil water conditions al...

160

Propagation through nonlinear time-dependent bubble clouds and the estimation of bubble populations from measured acoustic characteristics  

Microsoft Academic Search

For several decades the propagation characteristics of acoustic pulses (attenuation and sound speed) have been inverted in attempts to measure the size distributions of gas bubbles in liquids. While this has biomedical and industrial applications, most notably it has been attempted in the ocean for defence and environmental purposes, where the bubbles are predominantly generated by breaking waves. Such inversions

T. G. Leighton; S. D. Meers; P. R. White

2004-01-01

161

Time  

ERIC Educational Resources Information Center

When a teacher gives their time to a student, it is more significant to that student than anything else one could do for him or her. Music teachers deal with time all the time. Someone once said that "time is like money: we never have enough." This may seem true; however, time is not like money. One can make more money, but one cannot "make time."…

Circle, David

2005-01-01

162

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

SciTech Connect

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)

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

1982-05-01

163

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)

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.

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

2013-12-01

164

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

SciTech Connect

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.

Prevosto, L.; Mancinelli, B. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina)] [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina) [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina)

2013-12-15

165

Investigation of mode characteristics for a square cavity with a pedestal by a three-dimensional finite-difference time-domain technique  

Microsoft Academic Search

Mode characteristics of a strongly confined square cavity suspended in air via a pedestal on the substrate are investigated by a three-dimensional finite-difference time-domain technique. The mode wavelengths and mode quality factors (Q factors) are calculated as the functions of the size of the pedestal and the slope angle theta of the sidewalls of the square slab, respectively. For the

Qin Chen; Yong-Zhen Huang

2006-01-01

166

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

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…

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

2014-01-01

167

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

NASA Technical Reports Server (NTRS)

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

Baltas, C.; Morris, P. J.

1984-01-01

168

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

NASA Technical Reports Server (NTRS)

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.

Wilson, D. J.

1971-01-01

169

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

E-print Network

on July Z4. A sumxnary of the analysis of variance on soil nitrogen (NO3 and NH+4) as affected by source, rate and time of nitrogen application. 17 A summary of the analysis of variance on the dry weight of the plant organs and the yield of seed... cotton as affected by source, rate and time of nitrogen application, 17 A summary of the analysis of variance on ni- trogen (T. N. , NO3 and NH4) content of the different parts of the plant as affected by source, rate and time of nitrogen application...

Sadik, Mohamed Kamal

2012-06-07

170

Time trends of clinical characteristics in hepatocellular carcinoma patients with chronic hepatitis B virus infection: A field survey between 2000 and 2012  

PubMed Central

The hepatitis B virus (HBV) carrier rate has decreased in Japan; however, the incidence of HBV infection among hepatocellular carcinoma (HCC) patients has not decreased accordingly. In this study, we aimed to assess the time trends of the clinical characteristics in HCC patients with chronic HBV infection. Between 2000 and 2012, we enrolled a total of 156 HCC patients with chronic HBV infection in our field survey. The HCC risk was evaluated using the HCC prediction score, which is constructed from the characteristics of age, presence of liver cirrhosis and serum levels of albumin, bilirubin and HBV DNA. Lifestyle factors and the presence of diabetes mellitus were also evaluated. The time trends of patient characteristics were analyzed using the Jonckheere-Terpstra proportion trend test. Among HCC patients with chronic HBV infection, the proportion of patients at high risk according to the HCC prediction score significantly decreased during the study period (P=0.0005). Similarly, the proportion of patients with liver cirrhosis, ?3.5 g/dl serum albumin level, >4 log copies/ml serum HBV DNA level and ?60 g/day alcohol intake were also significantly decreased. The proportion of male and obese patients was not significantly altered, whereas the proportion of elderly (?65 years) and diabetic patients tended to increase during the study period (P=0.0654 and P=0.0528, respectively). In this study, we analyzed the time trends of the clinical characteristics in HCC patients with chronic HBV infection and demonstrated that aging and diabetes mellitus may be involved in the hepatocarcinogenesis in patients with chronic HBV infection. PMID:25279176

AMANO, KEISUKE; KAWAGUCHI, TAKUMI; KUROMATSU, RYOKO; KAWAGUCHI, ATSUSHI; MIYAJIMA, ICHIRO; IDE, TATSUYA; KAKUMA, TATSUYUKI; SATA, MICHIO

2014-01-01

171

Time trends of clinical characteristics in hepatocellular carcinoma patients with chronic hepatitis B virus infection: A field survey between 2000 and 2012.  

PubMed

The hepatitis B virus (HBV) carrier rate has decreased in Japan; however, the incidence of HBV infection among hepatocellular carcinoma (HCC) patients has not decreased accordingly. In this study, we aimed to assess the time trends of the clinical characteristics in HCC patients with chronic HBV infection. Between 2000 and 2012, we enrolled a total of 156 HCC patients with chronic HBV infection in our field survey. The HCC risk was evaluated using the HCC prediction score, which is constructed from the characteristics of age, presence of liver cirrhosis and serum levels of albumin, bilirubin and HBV DNA. Lifestyle factors and the presence of diabetes mellitus were also evaluated. The time trends of patient characteristics were analyzed using the Jonckheere-Terpstra proportion trend test. Among HCC patients with chronic HBV infection, the proportion of patients at high risk according to the HCC prediction score significantly decreased during the study period (P=0.0005). Similarly, the proportion of patients with liver cirrhosis, ?3.5 g/dl serum albumin level, >4 log copies/ml serum HBV DNA level and ?60 g/day alcohol intake were also significantly decreased. The proportion of male and obese patients was not significantly altered, whereas the proportion of elderly (?65 years) and diabetic patients tended to increase during the study period (P=0.0654 and P=0.0528, respectively). In this study, we analyzed the time trends of the clinical characteristics in HCC patients with chronic HBV infection and demonstrated that aging and diabetes mellitus may be involved in the hepatocarcinogenesis in patients with chronic HBV infection. PMID:25279176

Amano, Keisuke; Kawaguchi, Takumi; Kuromatsu, Ryoko; Kawaguchi, Atsushi; Miyajima, Ichiro; Ide, Tatsuya; Kakuma, Tatsuyuki; Sata, Michio

2014-11-01

172

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

E-print Network

inventory, and therefore, documented an initial step toward developing airborne-laser-based, on-the-fly, real-time, forest inventory systems. Results from this work demonstrated the utility and effectiveness of airborne scanning or profiling laser systems...

Zhao, Kaiguang

2009-05-15

173

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)

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.

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

2014-01-01

174

New space-time perspectives on the propagation characteristics of the Black Death epidemic and its relation to bubonic plague  

Microsoft Academic Search

This work presents, for the first time, a series of detailed space-time maps of Black Death mortality and infected area propagation\\u000a throughout the fourteenth century AD Europe. The maps integrate a variety of interdisciplinary knowledge bases about the devastating\\u000a epidemic and provide researchers and the interested public with an informative description of the Black Death dynamics (temporal\\u000a evolution, local and

George Christakos; Ricardo A. Olea

2005-01-01

175

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

NASA Technical Reports Server (NTRS)

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.

Williams, Peter E.; Pesnell, William Dean

2012-01-01

176

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

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

177

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

Microsoft Academic Search

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

Peter H. Dahl

2001-01-01

178

Changes in characteristics of soluble microbial products in membrane bioreactors associated with different solid retention times: Relation to membrane fouling  

Microsoft Academic Search

A membrane bioreactor (MBR) is a promising wastewater treatment technology, but there is a need for efficient control of membrane fouling, which increases operational and maintenance costs. Soluble microbial products (SMP) have been reported to act as major foulants in the operation of MBRs used for wastewater treatment. In this study, SMP in MBRs operated with different sludge retention times

Katsuki Kimura; Takuro Naruse; Yoshimasa Watanabe

2009-01-01

179

Use of time characteristics of laser emission in the determination of the optical density and absorption nonlinearity of matter  

Microsoft Academic Search

An internal resonator method is suggested for the determination of the optical density and absorption nonlinearity of matter. The method is based on the change in the Q factor of the resonator due to introduction of an absorbing medium and on the corresponding changes in the rise time and repetition period of laser pulses. Expressions are derived for the calculation

V. S. Burakov; A. F. Bokhonov; V. V. Zhukovskii; I. S. Zakharova; N. G. Kondrashov

1974-01-01

180

Compliance to a Cell Phone-Based Ecological Momentary Assessment Study: The Effect of Time and Personality Characteristics  

ERIC Educational Resources Information Center

Ecological momentary assessment (EMA) is a method that is now widely used to study behavior and mood in the settings in which they naturally occur. It maximizes ecological validity and avoids the limitations of retrospective self-reports. Compliance patterns across time have not been studied. Consistent compliance patterns could lead to data not…

Courvoisier, Delphine S.; Eid, Michael; Lischetzke, Tanja

2012-01-01

181

Effect of post-mortem time on post-thaw characteristics of Spanish ibex (Capra pyrenaica) spermatozoa.  

PubMed

Viable epididymal sperm can be obtained in the Spanish ibex during 24h after death, but it has been observed a significant effect of the post-mortem time on fertility success, so only goats inseminated with semen recovery during the first 8h became pregnant. The aim of this study was to determine the effect of post-mortem time on epididymal semen samples from of Spanish ibex. For this purpose, sperm samples from 36 males were collected at different post-mortem times, from 2 to 24h, and cryopreserved. Thawed samples were incubated for 2h at 37°C without dilution or after dilution in a modified Tyrode medium, in order to study the sperm resistance to dilution. Moreover, flow cytometry was used to assess the sperm viability (PI), phospolipid disorder of the plasma membrane (M540), mitochondrial membrane potential (Mitotracker Deep Red), indirect apoptosis markers (YOPRO-1) and sperm chromatin stability (SCSA(®)). Sperm motility was evaluated by computer-assisted sperm analysis (CASA). Our results have shown that post-mortem time caused a reduction in mitochondrial membrane potential. In this regard, the loss of energy could be responsible for the loss of maintenance of the membrane with a consequent increase in permeability leading to a decrease in sperm viability and motility, losing linearity and speed. Moreover, the loss of maintenance of the membrane influence the extent to which sperm will survive the cryopreservation process, as it shows the results obtained from the dilution-incubation resistance test. Finally, one important finding of this study is the demonstration of no effect of post-mortem time on post-thaw DNA integrity, giving us the possibility of using sperm samples from valuable males, even if it was not possible to process during the first 8h. PMID:22014412

Fernández-Santos, M R; Soler, A J; Ramón, M; Ros-Santaella, J L; Maroto-Morales, A; García-Álvarez, O; Bisbal, A; Garde, J J; Coloma, M A; Santiago-Moreno, J

2011-11-01

182

Interaural cross-correlation coefficient, apparent source width, and time/frequency characteristics of binaural running cross-correlation  

NASA Astrophysics Data System (ADS)

The interaural cross-correlation coefficient (IACC) descriptors attempt to characterize in a single number the binaural cross-correlation function at the expense of losing much detail in a manner similar to, but more problematic than, such descriptors as NC, STC, and NRC because much frequency- and rich time-domain information is lost. Recent computer simulations by Mason illuminated these problems and further stimulated the present study. Old binaural impulse recordings run through an analog computer algorithm (drawn from physiological modeling) were re-examined in an attempt to reveal trends and relationships that the current descriptors cannot. Issues of the time and frequency variance of the measured running coefficient are discussed in terms of apparent source width (ASW) for music in Troy Music Hall and simpler spaces.

Conant, David A.

2004-10-01

183

X-ray spectral and timing characteristics of the stars in the young open cluster IC 2391  

NASA Astrophysics Data System (ADS)

We present X-ray spectral and timing analysis of members of the young open cluster IC 2391 observed with the XMM-Newton observatory. We detected 99 X-ray sources by analysing the summed data obtained from MOS1, MOS2 and pn detectors of the EPIC camera; 24 of them are members, or probable members, of the cluster. Stars of all spectral types have been detected, from the early-types to the late-M dwarfs. Despite the capability of the instrument to recognize up to 3 thermal components, the X-ray spectra of the G, K and M members of the cluster are well described with two thermal components (at kT1 ˜ 0.3-0.5 keV and kT2 ˜ 1.0-1.2 keV respectively) while the X-ray spectra of F members require only a softer 1-T model. The Kolmogorov-Smirnov test applied to the X-ray photon time series shows that approximately 46% of the members of IC 2391 are variable with a confidence level >99%. The comparison of our data with those obtained with ROSAT/PSPC, nine years earlier, and ROSAT/HRI, seven years earlier, shows that there is no evidence of significant variability on these time scales, suggesting that long-term variations due to activity cycles similar to that on the Sun are not common, if present at all, among these young stars.

Marino, A.; Micela, G.; Peres, G.; Pillitteri, I.; Sciortino, S.

2005-01-01

184

Investigation of the laminar turbulent boundary layer transition on the rotor blades of the 25 m wind turbine HAT  

NASA Astrophysics Data System (ADS)

Measurements were performed on a 25m horizontal axis wind turbine to see if blade contraction is sufficiently smooth for laminar flow after 2 years of weather exposure. Small microphones fixed on the blade detected fluctuating pressure signals in the turbulent boundary layer. The results show that laminar flow is possible without blade maintenance, and that centrifugal forces do not play a big role in the development of the turbulent boundary layer. The transition layer position agrees well with the results of a two dimensional calculation method, which also gives reasonable results in the determination of the critical toughness height.

Vangroenewoud, G. J. H.; Boermans, L. M. M.; Vaningen, J. L.

1983-05-01

185

Characteristics and Time-Dependent Instability of Ga-Doped ZnO Thin Film Transistor Fabricated by Radio Frequency Magnetron Sputtering  

Microsoft Academic Search

We report on the fabrication and electrical characteristics of Ga-doped ZnO thin film transistors (TFTs). Low Ga-doped (0.7wt%) ZnO thin films were deposited on SiO2\\/p-Si substrates by rf magnetron sputtering. The GZO TFTs show a mobility of 1.76 cm2\\/V·s, an on\\/off ratio of 1.0 × 106, and a threshold voltage of 35 V. The time-dependent instability of the TFT is

Huang Hai-Qin; Sun Jian; Liu Feng-Juan; Zhao Jian-Wei; Hu Zuo-Fu; Li Zhen-Jun; Zhang Xi-Qing; Wang Yong-Sheng

2011-01-01

186

Write-once-read-many-times characteristics of Pt/Al2O3/ITO memory devices  

NASA Astrophysics Data System (ADS)

Nonvolatile write-once-read-many-times (WORM) Pt/Al2O3/ITO memory devices prepared at room temperature were demonstrated. The WORM memory devices show irreversible transition from the initial low resistance (ON) state to the high resistance (OFF) state, high ON/OFF ratio, long data retention, and good reading endurance in air at room temperature. The high performances are promising for employing the Pt/Al2O3/ITO WORM memory devices in permanent storage of information. The nonvolatile memory behaviors could be attributed to the formation and permanent rupture of conductive filament consisting of positively charged oxygen vacancies.

Wu, Shuxiang; Chen, Xinman; Ren, Lizhu; Hu, Wei; Yu, Fengmei; Yang, Kungan; Yang, Mei; Wang, Yunjia; Meng, Meng; Zhou, Wenqi; Bao, Dinghua; Li, Shuwei

2014-08-01

187

Mestif -- a Study of the Characteristics of Matter-Energy Space-Time and Information-Field  

NASA Astrophysics Data System (ADS)

In this paper, the concept of Information-Field (IF) is proposed and discussed in relation to Matter-Energy (ME) and Space-Time (ST). IF is the system of the organization and process of potential events. IF interacts and influences mutually with ME and hence also with ST. IF is pertinent in science in general, and is particularly significant in quantum cosmology, quantum computing, genome, information theory. The increasing understanding of cosmology and genome, the advancement in the information technology and the availability of tools to manage large data sets provide the platform and impetus for further research in the field.

Tan, James A. K.

2014-04-01

188

Calibrating passive acoustic monitoring: correcting humpback whale call detections for site-specific and time-dependent environmental characteristics.  

PubMed

This paper demonstrates the importance of accounting for environmental effects on passive underwater acoustic monitoring results. The situation considered is the reduction in shipping off the California coast between 2008-2010 due to the recession and environmental legislation. The resulting variations in ocean noise change the probability of detecting marine mammal vocalizations. An acoustic model was used to calculate the time-varying probability of detecting humpback whale vocalizations under best-guess environmental conditions and varying noise. The uncorrected call counts suggest a diel pattern and an increase in calling over a two-year period; the corrected call counts show minimal evidence of these features. PMID:24181982

Helble, Tyler A; D'Spain, Gerald L; Campbell, Greg S; Hildebrand, John A

2013-11-01

189

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

190

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)

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.

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

2011-12-01

191

Influence of autoignition delay time characteristics of different fuels on pressure waves and knock in reciprocating engines  

SciTech Connect

The functional relationship of autoignition delay time with temperature and pressure is employed to derive the propagation velocities of autoignitive reaction fronts for particular reactivity gradients, once autoignition has been initiated. In the present study of a variety of premixtures, with different functional relationships, such gradients comprise fixed initial temperature gradients. The smaller is the ratio of the acoustic speed through the mixture to the localised velocity of the autoignitive front, the greater are the amplitude and frequency of the induced pressure wave. This might lead to damaging engine knock. At higher values of the ratio, the autoignition can be benign with only small over-pressures. This approach to the effects of autoignition is confirmed by its application to a variety of experimental studies involving: (i)Imposed temperature gradients in a rapid compression and expansion machine. (ii)Onset of knock in an engine with advancing spark timing. (iii)Development of autoignition at a single hot spot in an engine. (iv)Autoignition fronts initiated by several hot spots. There is much diversity in the effects that can be produced by different fuels in different ranges of temperature and pressure. Higher values of autoignitive propagation speeds lead to increasingly severe engine knock. Such effects cannot always be predicted from the Research and Motor octane numbers. (author)

Bradley, D.; Kalghatgi, G.T. [Shell Global Solutions (UK), Shell Technology Centre Thornton, P.O. Box 1, Chester CH1 3SH (United Kingdom)

2009-12-15

192

Effect of cationic surfactants on characteristics and colorimetric behavior of polydiacetylene/silica nanocomposite as time-temperature indicator  

NASA Astrophysics Data System (ADS)

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).

Nopwinyuwong, Atchareeya; Kitaoka, Takuya; Boonsupthip, Waraporn; Pechyen, Chiravoot; Suppakul, Panuwat

2014-09-01

193

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

E-print Network

Vacuum (time- dependent) using PWL-LC (a) ? ?7.0,8.0vt cm? (b) ? ?24.0,25.0vt cm? ... 153 Figure 37. Fully-Implicit PWC-LC Cell-Average Scalar Flux for Beam in Pure Absorber with ?t = 2.0 ?s (a) ? ?0.0,2.0t s?? (b) ? ?18.0,20.0t s... Absorber with ?t = 2.0 ?s (a) ? ?0.0,2.0t s?? (b) ? ?18.0,20.0t s?? ......... 158 Figure 40. Fully-Implicit PWL-LC Cell-Average Scalar Flux for Beam in Pure Absorber with ?t = 0.1 ?s (a) ? ?1.9,2.0t s?? (b) ? ?19.9,20.0t s?? ......... 160...

Pandya, Tara M 1984-

2012-10-23

194

A characteristic time sequence of epileptic activity in EEG during dynamic penicillin-induced focal epilepsy--a preliminary study.  

PubMed

Penicillin-induced focal epilepsy is a well-known model in experimental epilepsy. However, the dynamic evolution of waveforms, DC-level changes, spectral content and coherence are rarely reported. Stimulated by earlier fMRI findings, we also seek for the early signs preceding spiking activity from frequency domain of EEG signal. In this study, EEG data is taken from previous EEG/fMRI series (six pigs, 20-24kg) of an experimental focal epilepsy model, which includes dynamic induction of epileptic activity with penicillin (6000IU) injection into the somatosensory cortex during deep isoflurane anaesthesia. No ictal discharges were recorded with this dose. Spike waveforms, DC-level, time-frequency content and coherence of EEG were analysed. Development of penicillin induced focal epileptic activity was not preceded with specific spectral changes. The beginning of interictal spiking was related to power increase in the frequencies below 6Hz or 20Hz, and continued to a widespread spectral increase. DC-level and coherence changes were clear in one animal. Morphological evolution of epileptic activity was a collection of the low-amplitude monophasic, bipolar, triple or double spike-wave forms, with an increase in amplitude, up to large monophasic spiking. In conclusion, in the time sequence of induced epileptic activity, immediate shifts in DC-level EEG are plausible, followed by the spike activity-related widespread increase in spectral content. Morphological evolution does not appear to follow a clear continuum; rather, intermingled and variable spike or multispike waveforms generally lead to stabilised activity of high-amplitude monophasic spikes. PMID:21511498

Silfverhuth, Minna J; Kortelainen, Jukka; Ruohonen, Jyrki; Suominen, Kalervo; Niinimäki, Jaakko; Sonkajärvi, Eila; Kiviniemi, Vesa; Alahuhta, Seppo; Jäntti, Ville; Tervonen, Osmo; Seppänen, Tapio

2011-09-01

195

Mesoscale characteristics  

Microsoft Academic Search

The spatial length, time, and propagation characteristics of the ocean mesoscale variability are examined throughout the globe. Sea surface height (SSH) variations from a combination of the Geosat Exact Repeat Mission, ERS-1, ERS-2, and TOPEX\\/Poseidon altimeter satellites are used to compute the observed covariance of the mesoscale. The mesoscale is defined as the residual SSH after removing a filtered large-scale

G. A. Jacobs; C. N. Barron; R. C. Rhodes

2001-01-01

196

Effect of aluminum and silicon reactants and HIP soak time on characteristics of glass-ceramic waste forms  

SciTech Connect

The high level liquid waste (HLLW) from nuclear fuel reprocessing is being calcined into solid granules and being stored onsite at the Idaho Chemical Processing Plant (ICPP) since 1963. Final disposal of the calcined waste in a geologic repository requires further consolidation of the calcine in to a solid waste form. One of the solid waste forms being considered for immobilization of the ICPP calcines is the glass-ceramic. The glass-ceramic waste form is a promising option because it can potentially reduce the calcined high level waste (HLW) volume significantly compared to glass waste forms while maintaining similar leach rates. Based on technical evaluations, and laboratory and pilot plant mockup tests, the Environmental Protection Agency (EPA) believes that the glass-ceramic process is more efficient than the glass process for ICPP calcine waste forms. The EPA has determined that the glass-ceramic waste form technology is an acceptable technology to meet the Best Demonstrated Acceptable Technology (BDAT) for ICPP HLW calcine. In this progress report, the impact of aluminum and silicon reactants and HIP soak time on leach rates, microstructure and phase composition of glass-ceramic waste forms are discussed.

Vinjamuri, K.

1993-04-01

197

Global Characteristics of the Correlation and Time Lag Between Solar and Ionospheric Parameters in the 27-day Period  

NASA Technical Reports Server (NTRS)

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.

Lee, Choon-Ki; Han, Shin-Chan; Dieter,Bilitza; Ki-Weon,Seo

2012-01-01

198

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

NASA Astrophysics Data System (ADS)

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.

Papenmeier, Svenja; Schrottke, Kerstin; Bartholomä, Alexander

2014-01-01

199

The impact of dietary fat withdrawal on carcass iodine value, belly characteristics, and changes in body fat over time.  

PubMed

The inclusion of unsaturated fats in pig diets has raised issues related to pork carcass fat quality. The objective of this experiment was to understand how withdrawal from the diet of unsaturated dietary fat before slaughter impacts the composition of jowl fat during the growth cycle and at market. Fifty individually housed pigs (PIC 337 × C22/29; initial BW = 59.3 ± 0.55 kg) were allotted based on sex and initial BW to 10 treatments for an 82-d experiment as follows: 3 dietary fat withdrawal times before slaughter (21, 42, or 63 d) by 3 dietary fat unsaturation loads (DFUL), which includea high intake of unsaturated fatty acids supplied through an inclusion of 5% corn oil (HIGH), a high intake of a mixture of saturated and unsaturated fatty acids supplied through an inclusion of 5% animal-vegetable blend (MED), and a moderate intake of unsaturated fatty acids supplied through an inclusion of 2.5% corn oil (LOW). Pigs were weighed and jowl adipose samples were collected on d 0, 21, 42, and 63 and at harvest on d 82. Data were analyzed using PROC MIXED with treatment and sex as fixed effects. At market (d 82), increasing the withdrawal of dietary fat further away from market increased 18:1 (P = 0.045) and tended to increase 14:0 concentrations (P = 0.054). It also significantly decreased 18:2 (P < 0.001) and tended to decrease 18:3 concentrations (P = 0.081). A HIGH DFUL resulted in the greatest 18:2 concentrations in jowl fat followed by LOW; MED resulted in the lowest 18:2 levels (P < 0.001). Dietary fat withdrawal before market significantly reduced carcass iodine value (IV) measured at d 82 (P = 0.006). In conclusion, elevated 18:2 intake makes lowering carcass IV in the depot fat very difficult and may take as long as 61 d. The withdrawal of unsaturated dietary fat apparently altered the fat depot to be more reflective of fat synthesized de novo, resulting in a more saturated depot fat. Importantly, this alteration of deposited fat composition did not translate into improved belly firmness, depth, weight, or fat color. PMID:25568373

Kellner, T A; Prusa, K J; Patience, J F

2015-01-01

200

Slaughter plant location, USDA quality grade, external fat thickness, and aging time effects on sensory characteristics of beef loin strip steak.  

PubMed

A boneless beef strip loin (IMPS #180) was fabricated from each of 320 carcasses to study the effects of slaughter plant location, quality grade, fat thickness, and aging time on beef tenderness and palatability. Carcasses were selected for fat thickness (< .5 cm or > or = .5 cm fat thickness) and USDA quality grade (Select or Low Choice) from two slaughter facilities (IBP, Inc., Garden City, KS or Excel Inc., Plainview, TX), and the strips were aged for either 7 or 14 d. Aging steaks 14 d improved all sensory traits and Warner-Bratzler shear (WBS) values regardless of all other main effects (P < .05). Steaks from Choice carcasses that were processed in Kansas had higher initial and sustained tenderness ratings than steaks from carcasses that were processed in Texas or Select steaks from Kansas after 7 d of aging (P < .05). However, aging for 14 d removed differences from all sensory characteristics of steaks from Kansas and Texas. All sensory scores for steaks from carcasses that graded Choice were higher than those from carcasses that graded Select (P < .05). The USDA quality grade did not affect WBS values, and fat thickness did not affect sensory characteristics or WBS values (P > .05). Therefore, aging beef strip loin steaks for 14 compared with 7 d improved sensory score and decreased WBS values, but fat thickness had no effect on the palatability of loin strip steaks processed under these conditions. PMID:9078481

Miller, M F; Kerth, C R; Wise, J W; Lansdell, J L; Stowell, J E; Ramsey, C B

1997-03-01

201

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)

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.

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

2013-05-01

202

Time-dependent characteristic of negative feedback optical amplifier at bit rates 10-Gbit/s based on an optical triode  

NASA Astrophysics Data System (ADS)

We proposed and demonstrated an all-optical triode based on a tandem wavelength converter using cross-gain modulation (XGM) in semiconductor optical amplifiers (SOAs). Negative feedback optical amplification scheme, which has the key advantages of reducing bit error rate and waveform reshaping at the output, was employed in this optical triode. This scheme utilizes an input signal and a negative feedback signal (a signal with reverse intensity to the input) and they were fed together into the optical amplifier. Manipulating the intensity of negative feedback signal enabled the noise suppression effect to be optimized and the outputs recorded improvements in bit error rate (BER) and also undergone waveform reshaping shown by the eye-pattern. In negative feedback optical amplifier, the negative feedback signal and input signal were fed into the SOA. However, due to XGM mechanism, there is a setback in which both signals could not be simultaneously fed. Therefore, by using an optical delay, negative feedback timing was manipulated and we investigate timing characteristics of negative feedback optical amplifier with BER and eye-pattern waveforms at 10 Gb/s.

Harada, Yuki; Azmi, Mohamad Syafiq; Azizan, Siti Aisyah; Matsutani, Takaomi; Maeda, Yoshinobu

2015-01-01

203

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

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

Das, Anuradha; Das, Suman; Biswas, Ranjit

2015-01-21

204

Enhancement Characteristics and Impact on Image Quality of Two Gadolinium Chelates at Equimolar Doses for Time-Resolved 3-Tesla MR-Angiography of the Calf Station  

PubMed Central

Purpose To compare enhancement characteristics and image quality of two macrocyclic gadolinium chelates, gadoterate meglumine and gadobutrol, in low-dose, time-resolved MRA of the calf station. Materials and Methods 100 consecutive patients with peripheral arterial disease (stages II-IV) were retrospectively analysed. Fifty patients were included in each group - 32 men and 18 women for gadobutrol (mean age 67 years) and 34 men, 16 women for gadoterate meglumine (mean age 64 years). 0.03 mmol/kg bw of either gadobutrol or gadoterate meglumine was injected. Gadobutrol was diluted 1?1 with normal saline (0.9% NaCl) to provide similar injection volume and bolus geometry compared to the undiluted 0.5 M dose of gadoterate meglumine. Signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR) and image quality were analysed and compared between the two groups. Results Mean SNR ranged from 83.0±46.7 (peroneal artery) to 96.4±64.5 (anterior tibial artery) for gadobutrol, and from 37.6±13.8 (peroneal artery) to 45.3±16.4 (anterior tibial artery) for the gadoterate meglumine group (p<0.0001). CNR values ranged from 30.1±20.1 (peroneal artery) to 37.6±26.0 (anterior tibial artery) for gadobutrol and from 14.9±8.0 (peroneal artery) to 18.6±16.4 (anterior tibial artery) for gadoterate meglumine (p<0.0001). No significant difference in image quality was found except for the peroneal arteries (p?=?0.006 and p?=?0.04). Interreader agreement was excellent (kappa 0.87–0.93) Conclusion The significantly better enhancement as assessed by SNR and CNR provided by gadobutrol compared to gadoterate meglumine does not translate into substantial differences in image quality in an equimolar, low-dose, time-resolved MRA protocol of the calves. PMID:24893292

Hansmann, Jan; Michaely, Henrik J.; Morelli, John N.; Luckscheiter, André; Schoenberg, Stefan O.; Attenberger, Ulrike I.

2014-01-01

205

Long-term impact of anaerobic reaction time on the performance and granular characteristics of granular denitrifying biological phosphorus removal systems.  

PubMed

Removal of nitrogen and phosphorus (P) from wastewater is successfully and widely practiced in systems employing both granular sludge technology and enhanced biological P removal (EBPR) processes; however, the key parameter, anaerobic reaction time (AnRT), has not been thoroughly investigated. Successful EBPR is highly dependent on an appropriate AnRT, which induces carbon and polyphosphate metabolism by phosphorus accumulating organisms (PAOs). Therefore, the long-term impact of AnRT on denitrifying P removal performance and granular characteristics was investigated in three identical granular sludge sequencing batch reactors with AnRTs of 90 (R1), 120 (R2) and 150 min (R3). The microbial community structures and anaerobic stoichiometric parameters related to various AnRTs were monitored over time. Free nitrite acid (FNA) accumulation (e.g., 0.0008-0.0016 mg HNO2-N/L) occurred frequently owing to incomplete denitrification in the adaptation period, especially in R3, which influenced the anaerobic/anoxic intracellular intermediate metabolites and activities of intracellular enzymes negatively, resulting in lower levels of poly-P and reduced activity of polyphosphate kinase. As a result, the Accumulibacter-PAOs population decreased from 51 ± 2.5% to 43 ± 2.1% when AnRT was extended from 90 to 150 min, leading to decreased denitrifying P removal performance. Additionally, frequent exposure of microorganisms to the FNA accumulation and anaerobic endogenous conditions in excess AnRT cases (e.g., 150 min) stimulated increased extracellular polymeric substances (EPS) production by microorganisms, resulting in enhanced granular formation and larger granules (size of 0.6-1.2 mm), but decreasing anaerobic PHA synthesis and glycogen hydrolysis. Phosphorus removal capacity was mediated to some extent by EPS adsorption in granular sludge systems that possessed more EPS, longer AnRT and relatively higher GAOs. PMID:23863379

Wang, Yayi; Guo, Gang; Wang, Hong; Stephenson, Tom; Guo, Jianhua; Ye, Liu

2013-09-15

206

Time-dependent characteristics of the dielectric barrier discharge in Xe-Cl2 mixture and kinetics of the XeCl? molecules  

NASA Astrophysics Data System (ADS)

Time-dependent characteristics of the dielectric barrier discharge in Xe-Cl2 mixture at chlorine concentration of 0.5% and kinetic processes governing the generation of XeCl? molecules are studied using the 1D fluid model. It is shown that at low voltage amplitude (5 kV) a one-peak mode of the discharge is observed and at high voltage amplitude (7 kV) a two-peak mode of the discharge appears. The radiation power of the XeCl? band increases with amplitude of the supply voltage. It is demonstrated that the harpoon reaction Xe? + Cl2 ? XeCl? + Cl provides the greatest contribution into generation of XeCl? exciplex molecules during short current pulses and the ion-ion recombination Xe+ 2 + Cl- ? XeCl* + Xe provides the greatest contribution during afterglow. Quenching of XeCl? molecules is a result of the radiative decay XeCl? ? Xe + Cl + hv (308 nm). During current spike the great contribution into quenching of XeCl? provides also the dissociative ionization e + XeCl? ? Xe+ + Cl + 2e.

Avtaeva, Svetlana

2014-04-01

207

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 Central

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

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

2014-01-01

208

Real-time electrocardiogram P-QRS-T detection-delineation algorithm based on quality-supported analysis of characteristic templates.  

PubMed

The main objective of this study is to introduce a simple, low-latency, and accurate algorithm for real-time detection of P-QRS-T waves in the electrocardiogram (ECG) signal. In the proposed method, real-time signal preprocessing, which includes high frequency noise filtering and baseline wander reduction, is performed by applying discrete wavelet transform (DWT). A method based on signal first-order derivative and adaptive threshold adjustment is employed for real-time detection of the QRS complex. Moreover, detection and delineation of P- and T-waves are achieved by correlation analysis conducted between signal and their templates. Besides, signal quality is investigated online, and if the quality of the analysis window is unacceptable, then the algorithm will guess (estimate) the locations of P- and T-waves. The operating characteristics of the proposed algorithm are evaluated by its implementation to an artificially generated ECG signal whose quality is adjustable from the best (Quality, 100%) to the worst (Quality, ?40%) cases based on the random-walk noise theory. The algorithm was applied to the MIT-BIH arrhythmia database, QT database, and Physionet/CinC challenge 2011competition database. The obtained results, which were based on the QT database, showed sensitivity and positive predictivity of Se=99.63% and P+=99.83%, Se=99.83% and P+=99.98%, and Se=99.74% and P+=99.89% for the detection of P-, QRS-, and T-waves, respectively, and the obtained results, which were based on the MIT-BIH arrhythmia database, showed Se=99.81% and P+=99.70% for the detection of the QRS complex. Moreover, it will be shown that the results of the proposed method are reliable for a minimum signal quality value of 70%. According to numerical assessments, 8-ms after the occurrence of R-wave, its location will be identified by the computer code of the proposed algorithm. This parameter is 198-ms and 177-ms for P- and T-waves, respectively. PMID:25063881

Karimipour, Atiyeh; Homaeinezhad, Mohammad Reza

2014-09-01

209

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

Microsoft Academic Search

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

Danielle A. M. Wieberg; Daniel J. Wescott

2008-01-01

210

Step-changes in the physical, chemical and biological characteristics of the Gulf of Maine, as documented by the GNATS time series  

USGS Publications Warehouse

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.

Balch, William M.; Drapeau, D.T.; Bowler, B.C.; Huntington, Thomas G.

2012-01-01

211

Epidemiology of leisure-time physical activity in socio-demographic, lifestyle and psychological characteristics of men and women in Greece: the ATTICA Study  

PubMed Central

Background We aimed to evaluate the prevalence, frequency and type of leisure-time physical activity (LTPA) among adults in Greece, as well as its relationship with socio-demographic, lifestyle and clinical characteristics of these people. Methods From May 2001 to December 2002 we randomly enrolled 1514 men and 1528 women, without any evidence of cardiovascular or any other chronic disease. The sampling was stratified by the age – gender distribution of (census 2001) of the greater area of Athens. Weekly energy expenditure assessed by considering frequency, duration (in minutes) and intensity of sports related physical activity during a usual week. Results 53% of men and 48% of women were classified as physically active. Men were more likely to be active as compared to women (p < 0.05), while the lowest activity rates were observed in 40 to 49 years old participants (p < 0.01). Physically active people had higher occupation skills, were more likely to live in rural areas, to be unmarried, non smokers and they were devoted to a healthier dietary pattern, as compared to sedentary, irrespective of age and sex (all p < 0.05). In addition, the cumulative risk factors score of obesity, hypertension, hypercholesterolemia and diabetes, was inversely associated with activity status (p < 0.001). Finally, physically active men and women were less likely to report depressive symptoms (p < 0.01), after various adjustments were made. Conclusion Half of the studied population reported physically inactive, indicating that sedentary lifestyle becomes a serious epidemic in Greece. High occupation skills, non-smoking, devotion to a healthier dietary pattern and a better cardiovascular risk factors profile were some of the determinants of physically active people. PMID:15836794

Pitsavos, Christos; Panagiotakos, Demosthenes B; Lentzas, Yannis; Stefanadis, Christodoulos

2005-01-01

212

Comparison of sludge characteristics and performance of a submerged membrane bioreactor and an activated sludge process at high solids retention time.  

PubMed

This work aims to compare biomass structure and performance of a submerged membrane bioreactor (SMBR) and an activated sludge process (ASP) treating the same domestic wastewater. The influence of the separation technique (membrane filtration or settling) and operation at high sludge-retention time (SRT) were investigated. Over the entire range of SRT (10-110 days), the SMBR achieved very good organic removal efficiencies, ranging from 90.8+/-0.2% to 94.2+/-1.6% based on total COD (TCOD), whereas those of ASP were between 87.4+/-1.8% and 90.3+/-0.8%. The contribution of the membrane in the increase in performance was due to total suspended solid retention and also partly due to retention of proteins and polysaccharides of the sludge supernatant. No significant difference in excess sludge production was observed between the two processes operated at the same SRT, but sludge production in SMBR decreased from 0.31 to 0.13 g(VSS)g(COD)(-1) as SRT increased from 9 to 110 days. The difference in sludge characteristics and performance was especially pronounced as SRT increased, resulting in deterioration of sludge settleability and effluent quality of the ASP (filamentous bacteria, increase of protein and polysaccharide release). Membrane filtration induced accumulation of soluble and colloidal proteins and polysaccharides which were progressively degraded in the supernatant as the SRT increased. At similar SRT, no significant difference was observed in the amount of extractable exocellular polymeric substances (bound EPS) from ASP and SMBR sludge. However as the SRT increased, the total specific amount of bound EPS in flocs decreased and the ratio proteins/polysaccharides also decreased. Concomitantly, laser diffraction analysis, microscopic observations, turbidity and DSVI measurement showed that the SRT increase induced significant modifications in sludge morphology in SMBR: decrease in floc size, densification of aggregates, and development of non-flocculating organisms. PMID:16759682

Massé, Anthony; Spérandio, Mathieu; Cabassud, Corinne

2006-07-01

213

The Influence of Temperature-Time Parameter of Welded Joints Thermal Treatment on Strength-Related Characteristics of Chromium-Molybdenum and Low-Alloy Manganese Steels  

Microsoft Academic Search

The article deals with the analysis of the dependence of strength-related characteristics of welded joints from chromium-molybdenum steel (ASTM A335 Grd. P5) and low-alloy manganese steel (S355J2G3 EN10025-2) upon the parameters of heat treatment. Steel mechanical properties after post-weld heat treatment were analyzed. Chromium- molybdenum (Cr - 5 %) steel and structural low-alloy manganese steel (Mn - 1.4 %) was

Algirdas Vaclovas VALIULIS

2007-01-01

214

Active play and screen time in US children aged 4 to 11 years in relation to sociodemographic and weight status characteristics: a nationally representative cross-sectional analysis  

Microsoft Academic Search

BACKGROUND: The high prevalence of childhood obesity underscores the importance of monitoring population trends in children's activity and screen time, and describing associations with child age, gender, race\\/ethnicity, and weight status. Our objective was to estimate the proportion of young children in the US who have low levels of active play or high levels of screen time, or who have

Sarah E Anderson; Christina D Economos; Aviva Must

2008-01-01

215

Marination with natural curing ingredients, storage time, and serving temperature effects on the sensory characteristics of forage-finished or commercially-sourced beef roasts.  

PubMed

Beef inside round roasts (n=144) were cut from rounds obtained from both forage-finished cattle (n=72) and commercially-sourced beef (n=72). Roasts were portioned to weigh 0.45-0.68kg each. Each roast was then randomly assigned one of the following treatments: control, injected-no cure, or injected-cured. Additionally, roasts were assigned a serving temperature (hot or cold) and storage treatments (0d or 28d post cooking). Roasts from forage-fed beef had a more red interior color and higher shear values, and also retained more brine than commercially-sourced beef (P<0.05). Curing roasts improved TBARS values in roasts served hot and significantly reduced sensory warmed-over and grassy flavors (P<0.05). Marinating forage-finished beef roasts significantly improves tenderness and flavor characteristics. PMID:22118983

McMurtrie, K E; Kerth, C R; Bratcher, C L; Curtis, P A; Smith, B

2012-03-01

216

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)

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].

Yudin, N. A.

2014-05-01

217

The Effect of Beaver Activity on the Ammonium Uptake and Water Residence Time Characteristics of a Third-Order Stream Reach  

NASA Astrophysics Data System (ADS)

Increasing beaver populations within low gradient basins in the northeastern United States are fundamentally changing the way water and dissolved nutrients are exported through these stream networks to the coast. Beaver dams can increase water residence time and contact with organic material, promote anoxic conditions and enhance both surface and hyporheic transient storage; all of these may have an impact on biogeochemical reactivity and nutrient retention. To quantitatively assess some of these effects we co-injected NaCl and NH4+ into the same 3rd-order stream reach in Massachusetts, USA under pre- and post-dam conditions. These experiments were done at similar discharge rates to isolate the impacts of a large natural beaver dam (7 m X 1.3 m) on the low-gradient (0.002) system where variable discharge also imparts a strong control on residence time. During the post-dam experiment there was an estimated 2300 m3 of water impounded behind the structure, which influenced more than 300 m of the 650 m stream reach. Our results showed that median transport time through the reach increased by 160% after dam construction. Additionally the tracer tailing time normalized to the corresponding median transport time increased from 1.08 to 1.51, indicating a pronounced tailing of the tracer signal in the post-dam condition. Data collected within the beaver pond just upstream of the dam indicated poor mixing and the presence of preferential flow paths through the generally stagnant zone. The uptake length (Sw) for NH4+ was 1250 m under the pre-dam condition, and may have changed for the post-dam reach in part because of the observed changes in residence time. As beaver population growth continues within these basins the consequences may be a smoothing of the outlet hydrograph and increased nutrient and organic matter removal and storage along the stream network.

Briggs, M.; Gooseff, M. N.; Wollheim, W. M.; Peterson, B. J.; Morkeski, K.

2009-12-01

218

Determination of the time delay in the case of two-path propagation on the basis of the attenuation characteristics for two adjacent frequencies  

NASA Technical Reports Server (NTRS)

Pronounced fading occurring in the line of sight radio links at frequencies below 10 GHz can be traced to the effects of multipath propagation. Modulation disturbances depend on travel time differences between the direct wave and the wave which is reflected at atmospheric layers. A method described for the determination of the time delay is based on an indirect approach which utilizes the difference in fading at various frequencies. The method was employed in measurements involving a distance of 181 km. The results obtained in the measurement are discussed.

Gilroi, H. G.

1979-01-01

219

Timing matters.  

PubMed

Cells are entities in space and time. Systems biology strives to understand their composition, structural organization as well as dynamic behavior under different conditions. Here, measures for dynamic properties such as characteristic times, time hierarchy and time-dependent response are reviewed. Using a number of examples from yeast and micro-organism systems biology, the importance of considering the timing in experimental and theoretical research is discussed. PMID:19941864

Klipp, Edda

2009-12-17

220

EVALUATING THE EFFECT OF PATTERN OF INFLATION AND DEFLATION AND CYCLE TIME ON THE PRESSURE RELIEVING CHARACTERISTIC OF A DYNAMIC SEAT CUSHION USING SEAT INTERFACE PRESSURE MEASUREMENTS  

E-print Network

the Xsensor pressure mapping system. Peak and mean pressures, percent surface area in contact under 30 mmHg for a cumulative time of at least 5 minutes (S>5), mean percentage of activated sensors under three thresholds (20, 30 and 40 mmHg; P5), mean percentage...

Mandala, Mahender

2011-08-31

221

Slaughter Plant Location, USDA Quality Grade, External Fat Thickness, and Aging Time Effects on Sensory Characteristics of Beef Loin Strip Steak1  

Microsoft Academic Search

A boneless beef strip loin (IMPS #180) was fabricated from each of 320 carcasses to study the effects of slaughter plant location, quality grade, fat thickness, and aging time on beef tender- ness and palatability. Carcasses were selected for fat thickness (< .5 cm or ? .5 cm fat thickness) and USDA quality grade (Select or Low Choice) from two

M. F. Miller; C. R. Kerth; J. W. Wise; J. L. Lansdell; J. E. Stowell; C. B. Ramsey

2010-01-01

222

Determination of the correct migration time and other parameters of the Haarhoff-van der Linde function from the peak geometry characteristics.  

PubMed

For Gaussian peaks, the migration time of the analyte results as the position of the top of the peak and the zone variance is proportional to the peak width. Similar relations have not yet been derived for the Haarhoff-van der Linde (HVL) function, which appears as a fundamental peak shape function in electrophoresis. We derive the relations between the geometrical measures of the HVL-shaped peak, i.e. the position of its maximum, its width and a measure of its asymmetry, and the respective parameters, a1 , a2 and a3 , of the corresponding HVL function. Under the condition of the HVL-shaped peak, the a1 parameter reflects the true migration time of the analyte, which may differ from the peak top position significantly. Our procedure allows us to express the parameters without the need of any external data processing (nonlinear regression). We demonstrate our approach on simulated peaks and on experimental data integrated by the ChemStation software (delivered with the CE instrumentation by Agilent Technologies). A significant improvement is achieved reading the migration time of the experimental and simulated peaks, which draws the error of the HVL-shaped peak migration time evaluation down to the resolution of the data sampling rate. This article is protected by copyright. All rights reserved. PMID:25475400

Dubský, Pavel; Dvo?ák, Martin; M?llerová, Ludmila; Gaš, Bohuslav

2014-12-01

223

Artificial Neural Network based prediction of performance and emission characteristics of a variable compression ratio CI engine using WCO as a biodiesel at different injection timings  

Microsoft Academic Search

Due to the increasing demand for fossil fuels and environmental threat due to pollution a number renewable sources of energy have been studied worldwide. In the present investigation influence of injection timing on the performance and emissions of a single cylinder, four stroke stationary, variable compression ratio, diesel engine was studied using waste cooking oil (WCO) as the biodiesel blended

Shivakumar; P. Srinivasa Pai; B. R. Shrinivasa Rao

2011-01-01

224

Physico-chemical, textural and structural characteristics of sous-vide cooked pork cheeks as affected by vacuum, cooking temperature, and cooking time.  

PubMed

This paper describes the influence of different factors on sous-vide cooked pork. Pork cheeks were cooked at different combinations of temperature (60°C or 80°C), time (5 or 12h) and vacuum (vacuum or air packaged). Weight losses were lower and moisture content higher in samples cooked for a shorter time (P=0.054) and at a lower temperature (P<0.001). Samples cooked at 60°C showed more lightness (L*) and redness (a*) (P<0.001). Lipid oxidation showed an interaction between cooking time and temperature (P=0.007), with higher TBARs values for samples cooked for 12h at 60°C and lower for those cooked for 12h at 80°C. Samples cooked at 80°C for 12h showed lower (P<0.05) values for most textural parameters than all the other types of samples. Vacuum packaging showed no influence on any of the studied variables. For the treatments evaluated, cooking temperature×time combination seems to be more important than vacuum packaging in the textural and colour parameters of pork cheeks. PMID:22154568

Sánchez Del Pulgar, José; Gázquez, Antonio; Ruiz-Carrascal, Jorge

2012-03-01

225

Water characteristics  

Microsoft Academic Search

Recent research on water characteristics is cited in this review article. Acid precipitation has been noted as one of the major environmental problems of the current decade. It poses a serious challenge to national and international bodies to protect water quality. Considerable interest was voiced in 1980 over the causes and effects, prevention and control of acid rain. One study

1981-01-01

226

Electrical interface characteristics (IV), optical time of flight measurements, and the x-ray (20 keV) signal response of amorphous-selenium\\/crystalline-silicon heterojunction structures  

Microsoft Academic Search

We have investigated the dark current, optical TOF (time of flight) properties, and the X-ray response of amorphousselenium (a-Se)\\/crystalline-silicon (c-Si) heterostructures for application in digital radiography. The structures have been studied to determine if an x-ray generated electron signal, created in an a-Se layer, could be directly transferred to a c-Si based readout device such as a back-thinned CCD (charge

David M. Hunter; Chu An Ho; George Belev; Giovanni de Crescenzo; Safa O. Kasap; Martin J. Yaffe

2011-01-01

227

Mancozeb wash-off from apple seedlings by simulated rainfall as affected by drying time of fungicide deposit and rain characteristics  

Microsoft Academic Search

In our studies apple seedlings (Malus domestica Borkh.) were used as model plants to elucidate the influence of drying time of the deposit, rain intensity, and rain volume on rainfastness of the contact fungicide mancozeb. Light (0.5mmh?1), heavy (5mmh?1), and torrential (48mmh?1) rain events were simulated using a laboratory rain simulator. In a first experiment, wash-off of mancozeb independent of

Mauricio Hunsche; Lutz Damerow; Michaela Schmitz-Eiberger; Georg Noga

2007-01-01

228

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

Microsoft Academic Search

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

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

2009-01-01

229

A Nonlinear Theory for Predicting the Effects of Unsteady Laminar, Turbulent, or Transitional Boundary Layers on the Attenuation of Shock Waves in a Shock Tube with Experimental Comparison  

NASA Technical Reports Server (NTRS)

The linearized attenuation theory of NACA Technical Note 3375 is modified in the following manner: (a) an unsteady compressible local skin-friction coefficient is employed rather than the equivalent steady-flow incompressible coefficient; (b) a nonlinear approach is used to permit application of the theory to large attenuations; and (c) transition effects are considered. Curves are presented for predicting attenuation for a shock pressure ratio up to 20 and a range of shock-tube Reynolds numbers. Comparison of theory and experimental data for shock-wave strengths between 1.5 and 10 over a wide range of Reynolds numbers shows good agreement with the nonlinear theory evaluated for a transition Reynolds number of 2.5 X 10(exp 5).

Trimpi, Robert L.; Cohen, Nathaniel B.

1961-01-01

230

Embedded Protostars in the Dust, Ice, and Gas In Time (DIGIT) Key Program: Continuum SEDs, and an Inventory of Characteristic Far-Infrared Lines from PACS Spectroscopy  

E-print Network

We present 50-210 um spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 um SEDs, as part of the Dust, Ice, and Gas in Time (DIGIT) Key Program. Some sources exhibit up to 75 H2O lines ranging in excitation energy from 100-2000 K, 12 transitions of OH, and CO rotational lines ranging from J=14-13 up to J=40-39. [O I] is detected in all but one source in the entire sample; among the sources with detectable [O I] are two Very Low Luminosity Objects (VeLLOs). The mean 63/145 um [O I] flux ratio is 17.2 +/- 9.2. The [O I] 63 um line correlates with Lbol, but not with the time-averaged outflow rate derived from low-J CO maps. [C II] emission is in general not local to the source. The sample Lbol increased by 1.25 (1.06) and Tbol decreased to 0.96 (0.96) of mean (median) values with the inclusion of the Herschel data. Most CO rotational diagrams are characterized by two optically thin components ( = (0.70 +/- 1.12) x 10^49 total particles). N_CO correlates strongly with Lb...

Green, Joel D; Jørgensen, Jes K; Herczeg, Gregory J; Kristensen, Lars E; Lee, Jeong-Eun; Dionatos, Odysseas; Yildiz, Umut A; Salyk, Colette; Meeus, Gwendolyn; Bouwman, Jeroen; Visser, Ruud; Bergin, Edwin A; van Dishoeck, Ewine F; Rascati, Michelle R; Karska, Agata; van Kempen, Tim A; Dunham, Michael M; Lindberg, Johan E; Fedele, Davide

2013-01-01

231

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)

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).

Ramos, Maria C.

2014-05-01

232

EMBEDDED PROTOSTARS IN THE DUST, ICE, AND GAS IN TIME (DIGIT) HERSCHEL KEY PROGRAM: CONTINUUM SEDs, AND AN INVENTORY OF CHARACTERISTIC FAR-INFRARED LINES FROM PACS SPECTROSCOPY  

SciTech Connect

We present 50-210 {mu}m spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 {mu}m spectral energy distributions, as part of the Dust, Ice, and Gas in Time Key Program. Some sources exhibit up to 75 H{sub 2}O lines ranging in excitation energy from 100 to 2000 K, 12 transitions of OH, and CO rotational lines ranging from J = 14 {yields} 13 up to J = 40 {yields} 39. [O I] is detected in all but one source in the entire sample; among the sources with detectable [O I] are two very low luminosity objects. The mean 63/145 {mu}m [O I] flux ratio is 17.2 {+-} 9.2. The [O I] 63 {mu}m line correlates with L{sub bol}, but not with the time-averaged outflow rate derived from low-J CO maps. [C II] emission is in general not local to the source. The sample L{sub bol} increased by 1.25 (1.06) and T{sub bol} decreased to 0.96 (0.96) of mean (median) values with the inclusion of the Herschel data. Most CO rotational diagrams are characterized by two optically thin components ( = (0.70 {+-} 1.12) x 10{sup 49} total particles). N{sub CO} correlates strongly with L{sub bol}, but neither T{sub rot} nor N{sub CO}(warm)/N{sub CO}(hot) correlates with L{sub bol}, suggesting that the total excited gas is related to the current source luminosity, but that the excitation is primarily determined by the physics of the interaction (e.g., UV-heating/shocks). Rotational temperatures for H{sub 2}O ( = 194 +/- 85 K) and OH ( = 183 +/- 117 K) are generally lower than for CO, and much of the scatter in the observations about the best fit is attributed to differences in excitation conditions and optical depths among the detected lines.

Green, Joel D.; Evans, Neal J. II; Rascati, Michelle R. [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Jorgensen, Jes K.; Dionatos, Odysseas; Lindberg, Johan E. [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Herczeg, Gregory J. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Kristensen, Lars E.; Yildiz, Umut A.; Van Kempen, Tim A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Lee, Jeong-Eun [Department of Astronomy and Space Science, Kyung Hee University, Gyeonggi 446-701 (Korea, Republic of); Salyk, Colette [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Meeus, Gwendolyn [Dpt. Fisica Teorica, Universidad Autonoma de Madrid, Campus Cantoblanco, E-28049 Madrid (Spain); Bouwman, Jeroen [Max Planck Institute for Astronomy, D-69117 Heidelberg (Germany); Visser, Ruud; Bergin, Edwin A. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Van Dishoeck, Ewine F.; Karska, Agata; Fedele, Davide [Max-Planck Institute for Extraterrestrial Physics, Postfach 1312, D-85741 Garching (Germany); Dunham, Michael M., E-mail: joel@astro.as.utexas.edu [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Collaboration: DIGIT Team1

2013-06-20

233

Effect of very fast chilling and aging time on ultra-structure and meat quality characteristics of Chinese Yellow cattle M. Longissimus lumborum.  

PubMed

Objectives of the current study were to evaluate meat ultra-structure and tenderness variation at different chilling regimes and aging times. Hot boned longissimus lumborum of 18 Chinese crossbred cattle were divided into 4 portions per side. One portion underwent very fast chilling (VFC, at -21 °C to achieve core temperature of 0 °C, then transferred to another incubator at 2 °C), whereas other treatments were held at 14, 7 and 0 °C for 10 h postmortem, respectively. At 10 h postmortem, all muscles were vacuum aged at 2 °C for 21 d. Cold shortened muscles had greatest absolute amount of tenderization during aging. VFC caused lowest sarcomere length, with super-contractions, ruptured Z-lines and myofibril cleavage, but improved myofibril fragmentation index (MFI), with no significant negative effect on toughness. Overall, aging improved the meat quality of cold shortened beef. Moreover, it should be prudent in some applications to apply VFC to excised muscles from a food safety perspective, and to improve tenderness compared to cold-shortened muscles. PMID:22857853

Li, Ke; Zhang, Yimin; Mao, Yanwei; Cornforth, Daren; Dong, Pengcheng; Wang, Renhuan; Zhu, He; Luo, Xin

2012-12-01

234

Real-Time Digital Data-Acquisition System for determining load characteristics. Volume 2. Operating, programming, and maintenance instructions. Final report  

SciTech Connect

The work sponsored under this contract included the design and construction of a Real-Time Digital Data Acquisition System (RTDDAS) to be used in substations for on-site recording and pre-processing load response data. The gathered data can be partially processed on site to compute the apparent, active and reactive powers, voltage and current rms values, and instantaneous values of phase voltages and currents. On-site processing capability is provided for rapid monitoring of the field data to ensure that the test setup is suitable. Production analysis of field data is accomplished off-line on a central computer from data recorded on a dual-density (800/1600) magnetic tape which is IBM-compatible. Parallel channels of data can be recorded at a variable rate from 480 to 9000 samples per second per channel. The RTDDAS is housed in a 9.1 m (30-ft) trailer which is shielded from electromagnetic interference and protected by isolators from switching surges; therefore, it can operate safely in a high-voltage substation environment where the tests must sometimes be performed. Information pertaining to the installation, software operation, and maintenance of the RTDDAS designed by IREQ is presented. A list of supporting documentation supplied by Data General Corporation is given.

Podesto, B.; Lapointe, A.; Larose, G.; Robichaud, Y.; Vaillancourt, C.

1981-03-01

235

HEDONIC PRICE ESTIMATION FOR KANSAS WHEAT CHARACTERISTICS  

Microsoft Academic Search

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

Juan Andres Espinosa; Barry K. Goodwin

1991-01-01

236

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

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

Deprez, Dieter; Fransen, Job; Lenoir, Matthieu; Philippaerts, Renaat M; Vaeyens, Roel

2014-12-01

237

Laser Microprobe Mass Spectrometry 1: Basic Principles and Performance Characteristics.  

ERIC Educational Resources Information Center

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)

Denoyer, Eric; And Others

1982-01-01

238

Decay time characteristics of La2O2S:Eu and La2O2S:Tb for use within an optical sensor for human skin temperature measurement.  

PubMed

We focus on the development of a remote temperature sensing technology, i.e., an optical laser-based sensor, using thermographic phosphors for medical applications, particularly within an electromagnetically hostile magnetic resonance imaging (MRI) environment. A MRI scanner uses a strong magnetic field and radio waves to generate images of the inside of the body. The quality of the image improves with increasing magnetic resonance; however, the drawback of applying a greater magnetic strength is the inducement of heat into the body tissue. Therefore, monitoring the patient's temperature inside MRI is vital, but until now, a practical solution for temperature measurement did not exist. We show europium doped lanthanum oxysulphide (La(2)O(2)S:Eu) and terbium doped lanthanum oxysulphide (La(2)O(2)S:Tb) are both temperature sensitive to a low temperature range of 10-50 degrees C when under ultraviolet (UV) excitation. The emission spectra and decay time characteristics of these phosphors were demonstrated. The results indicate that La(2)O(2)S:Eu has a quenching rate of 13.7 m degrees C(-1) and 4 m degrees C(-1) at 512 nm and 538 nm, respectively. In addition, La(2)O(2)S:Tb has a lower quenching rate of 4.19 m degrees C(-1) at 548 nm due to its faster decay time. PMID:18806849

Yap, Sook Voon; Ranson, Robert M; Cranton, Wayne M; Koutsogeorgis, Demosthenes

2008-09-20

239

Decay time characteristics of La2O2S:Eu and La2O2S:Tb for use within an optical sensor for human skin temperature measurement  

SciTech Connect

We focus on the development of a remote temperature sensing technology, i.e., an optical laser-based sensor, using thermographic phosphors for medical applications, particularly within an electromagnetically hostile magnetic resonance imaging (MRI) environment. A MRI scanner uses a strong magnetic field and radio waves to generate images of the inside of the body. The quality of the image improves with increasing magnetic resonance; however, the drawback of applying a greater magnetic strength is the inducement of heat into the body tissue. Therefore, monitoring the patient's temperature inside MRI is vital, but until now, a practical solution for temperature measurement did not exist. We show europium doped lanthanum oxysulphide (La2O2S:Eu) and terbium doped lanthanum oxysulphide (La2O2S:Tb) are both temperature sensitive to a low temperature range of 10-50 deg. C when under ultraviolet (UV) excitation. The emission spectra and decay time characteristics of these phosphors were demonstrated. The results indicate that La2O2S:Eu has a quenching rate of 13.7 m deg. C{sup -1} and 4 m deg. C{sup -1} at 512 nm and 538 nm, respectively. In addition, La2O2S:Tb has a lower quenching rate of 4.19 m deg. C{sup -1} at 548 nm due to its faster decay time.

Yap, Sook Voon; Ranson, Robert M.; Cranton, Wayne M.; Koutsogeorgis, Demosthenes

2008-09-20

240

Seasonal characteristics of fine particulate matter (PM) based on high resolution time-of-flight aerosol mass spectrometric (HR-ToF-AMS) measurements at the HKUST Supersite in Hong Kong  

NASA Astrophysics Data System (ADS)

Atmospheric particulate matter (PM) remains poorly understood due to the lack of comprehensive measurements at high time resolution for tracking its dynamic features and the lack of long-term observation for tracking its seasonal variability. Here, we present highly time-resolved and seasonal compositions and characteristics of non-refractory components in PM with diameter less than 1 ?m (NR-PM1) at a suburban site in Hong Kong. The measurements were made with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) at the Hong Kong University of Science and Technology (HKUST) Air Quality Research Supersite for four months, with one in each season of the year. The average NR-PM1 concentration of ~15 ?g m-3 is higher than those AMS measurements made in South Korea and Japan, but lower than those in North China, the Yangtze River Delta and the nearby Pearl River Delta. The seasonal dependence of the total NR-PM1 monthly averaged concentrations was small but that of the fractions of the species in NR-PM1 was significant. Site characteristic plays an important role in the relative fractions of species in NR-PM1 and our results are generally consistent with measurements at other non-urban sites in this regard. Detailed analyses were conducted on the AMS data in the aspects of (1) species concentrations, (2) size distributions, (3) degree of oxygenation of organics, and (4) positive matrix factorization (PMF)-resolved organic factors in a seasonal context, as well as with air mass origin from back-trajectory analysis. Sulfate had the highest fraction in NR-PM1 (> 40%) and the surrogates of secondary organic species, semi-volatile oxygenated organic aerosol (SVOOA) and low-volatility oxygenated organic aerosol (LVOOA), prevailed (~80%) in the organic portion of NR-PM1. Local contributions to the organic portion of NR-PM1 at this suburban site was strongly dependent on season. The hydrocarbon-like organic aerosol (HOA) factor related to local traffic emissions contributed > 10% to organic aerosols in spring and summer, but only 6-7% in autumn and winter. The cooking organic aerosol (COA) factor contributed > 10% to organic aerosols in winter. With the aid of highly time-resolved data, diurnal patterns of the degree of oxygenation of organic aerosols were used to determine the sources and formation processes of the least understood organic portion of PM. The oxygen-to-carbon atomic ratio (O : C) and average carbon oxidation state (OSC) showed little variation in autumn and winter when the long-range transport of oxidized organics dominated, whereas they peaked in the afternoon in spring and summer when locally produced secondary organic aerosol prevailed. Air mass origin, in contrast, had a strong influence on both NR-PM1 concentrations and the fractions of species in NR-PM1. The findings of the current study provide a better understanding of the role of air mass origin in the seasonal characteristics of the PM composition and the relative importance of local vs. transported organic aerosols in this region.

Li, Y. J.; Lee, B. P.; Su, L.; Fung, J. C. H.; Chan, C. K.

2014-08-01

241

Seasonal characteristics of fine particulate matter (PM) based on high-resolution time-of-flight aerosol mass spectrometric (HR-ToF-AMS) measurements at the HKUST Supersite in Hong Kong  

NASA Astrophysics Data System (ADS)

Atmospheric particulate matter (PM) remains poorly understood due to the lack of comprehensive measurements at high time resolution for tracking its dynamic features and the lack of long-term observation for tracking its seasonal variability. Here, we present highly time-resolved and seasonal compositions and characteristics of non-refractory components in PM with a diameter less than 1 ?m (NR-PM1) at a suburban site in Hong Kong. The measurements were made with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) at the Hong Kong University of Science and Technology (HKUST) Air Quality Research Supersite for 4 months, with one in each season of the year. The average NR-PM1 concentration of ~ 15 ?g m-3 is higher than those AMS measurements made in South Korea and Japan, but lower than those in North China, the Yangtze River Delta and the nearby Pearl River Delta. The seasonal dependence of the total NR-PM1 monthly averaged concentrations was small, but that of the fractions of the species in NR-PM1 was significant. Site characteristic plays an important role in the relative fractions of species in NR-PM1 and our results are generally consistent with measurements at other non-urban sites in this regard. Detailed analyses were conducted on the AMS data in the aspects of (1) species concentrations, (2) size distributions, (3) degree of oxygenation of organics, and (4) positive matrix factorization (PMF)-resolved organic factors in a seasonal context, as well as with air mass origin from back-trajectory analysis. Sulfate had the highest fraction in NR-PM1 (> 40%), and the surrogates of secondary organic species - semi-volatile oxygenated organic aerosol (SVOOA) and low-volatility oxygenated organic aerosol (LVOOA) - prevailed (~ 80%) in the organic portion of NR-PM1. Local contributions to the organic portion of NR-PM1 at this suburban site was strongly dependent on season. The hydrocarbon-like organic aerosol (HOA) factor related to local traffic emissions contributed > 10% to organic aerosols in spring and summer but only 6-7% in autumn and winter. The cooking organic aerosol (COA) factor contributed > 10% to organic aerosols in winter. With the aid of highly time-resolved data, diurnal patterns of the degree of oxygenation of organic aerosols were used to determine the sources and formation processes of the least understood organic portion of PM. The oxygen-to-carbon atomic ratio (O : C) and average carbon oxidation state OS C) showed little variation in autumn and winter, when the long-range transport of oxidized organics dominated, whereas they peaked in the afternoon in spring and summer, when locally produced secondary organic aerosol prevailed. Air mass origin, in contrast, had a strong influence on both NR-PM1 concentrations and the fractions of species in NR-PM1. The findings of the current study provide a better understanding of the role of air mass origin in the seasonal characteristics of the PM composition and the relative importance of local vs. transported organic aerosols in this region.

Li, Y. J.; Lee, B. P.; Su, L.; Fung, J. C. H.; Chan, C. K.

2015-01-01

242

IT'S ABOUT TIME Characteristic times in biogeochemistry and climate  

E-print Network

,days AEROCOM, Textor et al., ACP, 2006 Characterize and compare processes in chemical transport modelsconcentration(ppm) 180 200 220 240 260 280 300 320 340 360 380 800 1000 1200 1400 1600 1800 2000 Law Dome Adelie

Schwartz, Stephen E.

243

GEOLOGICAL CHARACTERISTICS  

E-print Network

CAPSULE DESCRIPTION: Ilmenite, hemo-ilmenite or titaniferous magnetite accumulations as cross-cutting lenses or dike-like bodies, Ia> ers or disseminations within anorthositiclgabbroicinoritic rocks. These deposits can be subdivided into an ilmenite subtype (anorthosite-hosted titanium-iron) and a titaniferous magnetite subtype (gabbro-anorthosite-hosted iron-titanium). TECTONIC SETTING: Commonly associated with anorthosite-gabbro-norite-monzonite (mangerite)charnockite granite (AMCG) suites that are conventionally interpreted to be anorogenic and/or extensional. Some of the iron-titanium deposits occur at continental margins related to island arc magmatism followed by an episode of erogenic compression. DEPOSITIONAL ENVIRONMENT i GEOLOGICAL SETTING: Deposits occur in intrusive complexes which typically are emplaced at deeper levels in the crust. Progressive differentiation of liquids residual from anorthosite-norite magmas leads to late stage intrusions enriched in Fe and Ti oxides and apatite. AGE OF MINERALIZATION: Mainly Mesoproterozoic (1.65 to 0.90 Ga) for the ihnenite deposits, but this may be a consequence of a particular combination of tectonic circumstances, rather than any a priori temporal control. The Fe-Ti deposits with titaniferous magnetite do not appear to be restricted in time. HOST/ASSOCIATED ROCKS: Hosted by massive, layered or zoned intrusive complexes- anorthosite, norite,

G. A. Gross; C. F. Gower; D. V. Lefebure; Commodities (byproducts) Ti

244

Student Characteristics Report, Fall 1977.  

ERIC Educational Resources Information Center

As part of a continuing survey of student characteristics at the Metropolitan Community Colleges, this report presents data from 14,918 regular credit enrollment students for fall 1977 and compares them to data from 1972. For the first time in the district's history, the majority of students (54%) were female, a shift that has only occurred in the…

Metropolitan Community Colleges of Kansas City, MO. Div. of Planning and Development.

245

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

NASA Technical Reports Server (NTRS)

A three-dimensional computer code (KIVA) is being modified to include state-of-the-art submodels for diesel engine flow and combustion: spray atomization, drop breakup/coalescence, multi-component fuel vaporization, spray/wall interaction, ignition and combustion, wall heat transfer, unburned HC and NOx formation, soot and radiation, and the intake flow process. Improved and/or new submodels which were completed are: wall heat transfer with unsteadiness and compressibility, laminar-turbulent characteristic time combustion with unburned HC and Zeldo'vich NOx, and spray/wall impingement with rebounding and sliding drops. Results to date show that adding the effects of unsteadiness and compressibility improves the accuracy of heat transfer predictions; spray drop rebound can occur from walls at low impingement velocities (e.g., in cold-starting); larger spray drops are formed at the nozzle due to the influence of vaporization on the atomization process; a laminar-and-turbulent characteristic time combustion model has the flexibility to match measured engine combustion data over a wide range of operating conditions; and finally, the characteristic time combustion model can also be extended to allow predictions of ignition. The accuracy of the predictions is being assessed by comparisons with available measurements. Additional supporting experiments are also described briefly. To date, comparisons with measured engine cylinder pressure and heat flux data were made for homogeneous charge, spark-ignited and compression-ignited engines. The model results are in good agreement with the experiments.

Reitz, R. D.; Rutland, C. J.

1992-01-01

246

Study on electromagnetic damp characteristics of permanent magnet synchronous generator  

Microsoft Academic Search

The electromagnetic damp characteristics, namely, the characteristics of electromagnetic torque varying according to angular velocity, of permanent magnet synchronous generator (PMSG) were derived by phasor method. The relationships between the characteristics and PMSG interior parameters were discussed. Transient process and electromechanical time constant were proposed. Both the analysis result and the simulation in MATLAB demonstrate that approximately linear characteristics and

Ningning Zhou; Guoxin Ma

2008-01-01

247

An assessment on seasonal analysis of wind energy characteristics and wind turbine characteristics  

Microsoft Academic Search

This paper presents seasonal variations of the wind characteristics and wind turbine characteristics in the regions around Elazig, namely Maden, Agin and Keban. Mean wind speed data in measured hourly time series format is statistically analyzed for the six year period 1998–2003. The probability density distributions are derived from the time series data and their distributional parameters are identified. Two

E. Kavak Akpinar; S. Akpinar

2005-01-01

248

Effects of Time Specific F-strain Mycoplasma gallisepticum Inoculation Overlays on Prelay ts-11-strain M. gallisepticum Vaccination on Digestive and Reproductive Organ Characteristics of Commercial Egg-Laying Hens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two trials were conducted to determine the effects of a prelay ts11-strain M. gallisepticum (ts11MG) vaccination alone or in conjunction with F-strain M. gallisepticum (FMG) inoculation overlays at 2 different age periods during lay on the digestive and reproductive organ characteristics of commerci...

249

Thermistor Characteristics and Stability.  

ERIC Educational Resources Information Center

Discusses the uses of thermistors in teaching electronics and semiconductors. Describes how to experimentally measure and graph the characteristics of a thermistor. Suggests one possible approach to understand the shapes of the characteristics. (CW)

Fricker, H. S.

1987-01-01

250

Wetland Characteristics and Denitrification  

EPA Science Inventory

This presentation serves as an initial summary of our wetland field work's watershed characteristics hydrologic characteristics, water quality measurements, and denitrification assays. We present our measurement results in the context of wetland type (Estuarine, Freshwater Mars...

251

Theory of Characteristics  

NASA Technical Reports Server (NTRS)

The theory of characteristics will be presented generally for quasilinear differential equations of the second order in two variables. This is necessary because of the manifold requirements to be demanded from the theory of characteristics.

Tollmien, W.

1949-01-01

252

Characteristics of Pulsating Aurora  

NASA Astrophysics Data System (ADS)

We have investigated the spatiotemporal characteristics of pulsating auroral patches observed with an all-sky imager located at Poker Flat, Alaska. Pulsating aurora often covers the entire sky with intermixed large and small-scale patches that vary in intensity or disappear and reappear on different time scales and timings. The broad definition of pulsating aurora covers patches and bands from tens to several tens of km which have a quasi-periodic temporal variation from 1 s to tens of seconds. In this paper we examine >15 patches from different events. We analyze all-sky movies (557.7 nm, 3.31 Hz) with a simple, yet robust, technique that allows us to determine the scale size dependent variability of the >15 individual patches. A spatial 2D Fourier Transform is used to separate the aurora into different horizontal scale sizes, and by correlating each patch for all image separations and available scale sizes smaller than the patch itself, we reveal what scale sizes are pulsating and their variability. The patches are found to be persistent, meaning that we can follow them for typically 5 minutes. The period of the pulsations is often remarkably variable and it seems that only certain scale sizes pulsate (typically the size of the patch). The patches drift with the background ExB plasma drift indicating that the magnetospheric source mechanism drifts with the field lines.

Humberset, B. K.; Gjerloev, J. W.; Mann, I. R.; Samara, M.; Michell, R.

2013-12-01

253

Characteristic Evolution and Matching  

E-print Network

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 current 3D black codes that simulate binary black holes. A prime application of characteristic evolution is Cauchy-characteristic matching, which is also reviewed.

J. Winicour

2001-02-20

254

The Influence of Classroom Characteristics on High School Teacher Turnover  

Microsoft Academic Search

This paper examines the effect of class load and other factors on teacher turnover. Unlike previous studies, class load characteristics--class size, number of classes taught, and percentage of class time spent in areas outside a teacher's certification area--are included along with salary, personal characteristics, and district characteristics in a discrete time hazard model to simulate the effects of changing classroom

Daniel Mont; Daniel I. Rees

1996-01-01

255

Globally mapping baseflow characteristics  

NASA Astrophysics Data System (ADS)

Characterizing baseflow, the slowly varying portion of streamflow, is important for water resources management, hydropower generation, tracking contaminant transport, and other applications. Most previous studies of baseflow have analyzed small groups of catchments with similar characteristics. Now, to develop globally applicable models of baseflow characteristics, Beck et al. studied observations from 3394 catchments around the world with a variety of climatic, hydrological, and physiographic characteristics. Their novel approach investigates the relationship between catchment characteristics and baseflow characteristics, showing how baseflow is related to annual potential evaporation, mean snow water equivalent depth, abundance of surface water bodies, and other landscape characteristics. Their global maps of baseflow characteristics—which could be useful for benchmarking and calibrating hydrological models and for a variety of other hydrological applications—are freely available at http://www.hydrology-amsterdam.nl.

Balcerak, Ernie

2013-12-01

256

Sleep Characteristics in Breastfeeding and Formula-Feeding Mothers  

E-print Network

characteristics of light sleep, deep sleep, and REM sleep while controlling for age, education and nicotine use, and a t-test on total sleep time, did not demonstrate any significant differences between groups. The variance of sleep characteristics measured...

Rosen, Elizabeth Anne Averill

2009-12-09

257

Time After Time  

NSDL National Science Digital Library

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.

Service, National S.

2009-04-22

258

Characteristic Evolution and Matching  

E-print Network

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.

Jeffrey Winicour

2005-12-08

259

Educators' professional characteristics  

Microsoft Academic Search

Purpose – To develop a comprehensive model of professional characteristics of an educator that will prepare them for high standards of professional achievements, as all professions demand standardization and formulation of guidelines in today's competitive environment. Design\\/methodology\\/approach – Literature on essentials of an educator was sourced to collect the various characteristics for diverse academic oriented goals. A set of ten

R. Krishnaveni; J. Anitha

2007-01-01

260

The Use of a priori Information in ICA-Based Techniques for Real-Time fMRI: An Evaluation of Static/Dynamic and Spatial/Temporal Characteristics  

PubMed Central

Real-time brain functional MRI (rt-fMRI) allows in vivo non-invasive monitoring of neural networks. The use of multivariate data-driven analysis methods such as independent component analysis (ICA) offers an attractive trade-off between data interpretability and information extraction, and can be used during both task-based and rest experiments. The purpose of this study was to assess the effectiveness of different ICA-based procedures to monitor in real-time a target IC defined from a functional localizer which also used ICA. Four novel methods were implemented to monitor ongoing brain activity in a sliding window approach. The methods differed in the ways in which a priori information, derived from ICA algorithms, was used to monitor a target independent component (IC). We implemented four different algorithms, all based on ICA. One Back-projection method used ICA to derive static spatial information from the functional localizer, off-line, which was then back-projected dynamically during the real-time acquisition. The other three methods used real-time ICA algorithms that dynamically exploited temporal, spatial, or spatial-temporal priors during the real-time acquisition. The methods were evaluated by simulating a rt-fMRI experiment that used real fMRI data. The performance of each method was characterized by the spatial and/or temporal correlation with the target IC component monitored, computation time, and intrinsic stochastic variability of the algorithms. In this study the Back-projection method, which could monitor more than one IC of interest, outperformed the other methods. These results are consistent with a functional task that gives stable target ICs over time. The dynamic adaptation possibilities offered by the other ICA methods proposed may offer better performance than the Back-projection in conditions where the functional activation shows higher spatial and/or temporal variability. PMID:23483841

Soldati, Nicola; Calhoun, Vince D.; Bruzzone, Lorenzo; Jovicich, Jorge

2013-01-01

261

A proposal of the diagnosis-dynamic characteristic (DDC) model describing the relation between search time and confidence levels for a dichotomous judgment, and its application to ROC curve generation  

NASA Astrophysics Data System (ADS)

When physicians inspect an image, they make up a certain degree of confidence that the image are abnormal; p(t), or normal; n(t)[n(t)=1-p(t)]. After infinite time of the inspection, they reach the equilibrium levels of the confidence of p*=p(?) and n*=n(?). There are psychological conflicts between the decisions of normal and abnormal. We assume that the decision of "normal" is distracted by the decision of "abnormal" by a factor of k(1 + ap), and in an inverse direction by a factor of k(1 + bn), where k ( > 0) is a parameter that relates with image quality and skill of the physicians, and a and b are unknown constants. After the infinite time of inspection, the conflict reaches the equilibrium, which satisfies the equation, k(1 + ap*)n* = k(1 + bn*)p*. Here we define a parameter C, which is 2p*/[p*(1 - p*)]. After the infinite time of inspection, the conflict reaches the equilibrium, which satisfies t that changes in the confidence level with the time (dp/dt) is proportional to [k(1+ap)n - k(1+bn)p], i.e. k[-cp2 + (c - 2)p + 1]. Solving the differential equation, we derived the equation; t(p) and p(t) depending with the parameters; k, c, S. S (0-1) is the value arbitrary selected and related with probability of "abnormal" before the image inspection (S = p(0)). Image reading studies were executed for CT images. ROC curves were generated both by the traditional 4-step score-based method and by the confidence level; p estimated from the equation t(p) of the DDC model using observed judgment time. It was concluded that ROC curves could be generated by measuring time for dichotomous judgment without the subjective scores of diagnostic confidence and applying the DDC model.

Matsumoto, Toru; Fukuda, Nobuo; Furukawa, Akira; Suwa, Koji; Wada, Shinichi; Matsumoto, Mitsuomi; Sone, Shusuke

2006-03-01

262

Characteristic Evolution and Matching  

E-print Network

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.

Jeffrey Winicour

2012-01-12

263

[10] S. V. Campos, E. M. Clarke, W. Marrero, M. Minea, and H. Hiraishi. Computing quantitative characteristics of finitestate realtime systems. In IEEE RealTime Systems Symposium, 1994.  

E-print Network

. In IEEE Real­Time Systems Symposium, 1993. [17] T. A. Henzinger, P. H. Ho, and H. Wong­Toi. Hy--427. Springer­Verlag, 1994. [12] E. M. Clarke and E. A. Emerson. Synthesis of synchronization skeletons­Verlag, 1981. Lecture Notes in Computer Science, volume 131. [13] E. M. Clarke, E. A. Emerson, and A. P. Sistla

Clarke, Edmund M.

264

Adjoint operator approach in marginal separation theory  

NASA Astrophysics Data System (ADS)

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.

Braun, Stefan; Scheichl, Stefan; Kluwick, Alfred

2013-10-01

265

Time division multiplexing  

Microsoft Academic Search

The characteristics of time division multiplexing are explained for both pulse amplitude modulation and pulse code modulation systems. An analysis of word synchronization in asynchronous numerical multiplexing is included. The hierarchy in numerical multiplexing is discussed. The strategy for frame aligning, frame dimensioning, and the jitter of waiting time are treated. Bibtex entry for this abstract Preferred format for this

M. Decina; C. Rossi

1980-01-01

266

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 ...

267

A Characteristic Particle Length  

E-print Network

It is argued that there are characteristic intervals associated with any particle that can be derived without reference to the speed of light $c$. Such intervals are inferred from zeros of wavefunctions which are solutions to the Schr\\"odinger equation. The characteristic length is $\\ell=\\beta^2\\hbar^2/(8Gm^3)$, where $\\beta=3.8\\dots$; this length might lead to observational effects on objects the size of a virus.

Mark D. Roberts

2014-06-14

268

Hydrodynamic characteristics of UASB bioreactors.  

PubMed

The hydrodynamic characteristics of UASB bioreactors operated under different organic loading and hydraulic loading rates were studied, using three laboratory scale models treating concocted sucrose wastewater. Residence time distribution (RTD) analysis using dispersion model and tanks-in-series model was directed towards the characterization of the fluid flow pattern in the reactors and correlation of the hydraulic regime with the biomass content and biogas production. Empty bed reactors followed a plug flow pattern and the flow pattern changed to a large dispersion mixing with biomass and gas production. Effect of increase in gas production on the overall hydraulics was insignificant. PMID:23505813

John, Siby; Tare, Vinod

2011-10-01

269

Propagation characteristics of satellite links  

NASA Astrophysics Data System (ADS)

Lower and upper atmospheric effects on signal characteristics of satellite transmissions are reviewed. The effects of importance produced by the ionosphere are the fading, caused by irregularities in the equatorial and high latitude ionospheres, the time delay errors produced by the passage of radiowaves through the ionospheric electrons, and absorption of the lower ionosphere at auroral and polar cap latitudes. The tropospheric effects include absorption by constituents and the problem of scattering of energy into unwanted polarizations. In some applications low angle effects of refraction and scintillation are also of importance.

Aarons, J.

1982-04-01

270

Commercial Buildings Characteristics, 1992  

SciTech Connect

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.

Not Available

1994-04-29

271

Hypergol engine restart characteristics.  

NASA Technical Reports Server (NTRS)

Several hard restarts and two failures to restart occurred during simulated high-altitude testing of the three Apollo spacecraft primary propulsion engines. Abnormal restarts resulted from flow perturbations by trapped propellants, ignition characteristics of partially frozen propellants, and fuel nitrate retention. Engine restart characteristics are correlated with thermodynamic phenomena that occur after engine shutdown; these include desorption of dissolved pressurant gases and evaporative freezing of propellant residuals. These results are applied to conceptual space shuttle OMS hypergol engines to identify potential restart problems.

Kerkam, B. F.; Kahl, R. C.

1972-01-01

272

Metering Characteristics of Carburetors  

NASA Technical Reports Server (NTRS)

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.

Tice, Percival S; Dickinson, H C

1919-01-01

273

Interrelationships of Watershed Characteristics  

Microsoft Academic Search

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

Don M. Gray

1961-01-01

274

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.

2001-01-01

275

Attractive characteristics of mirrors  

SciTech Connect

A summary of the attractive characteristics of mirror devices is presented. Recent progress in development of axisymmetric mirror devices is described. Potentialities of mirrors as a basis for D{sup 3}He fusion power generators and high-flux neutron sources for fusion material tests are discussed.

Post, R.F.; Ryutov, D.D.

1994-12-15

276

Characteristics of Cheetahs  

NSDL National Science Digital Library

What are some characteristics of cheetahs? First, go to Graphic Organizer and use this graphic organizer to organize your answers to the following questions. Second, go to Cheetah Pictures and look at these pictures of cheetahs. Write five things that describe what cheetahs look like and record your answers in your graphic organizer under "What They Look Like" Third, ...

Ms.weathers

2012-04-05

277

Characteristics of Hypermedia Presentations.  

ERIC Educational Resources Information Center

This paper addresses those characteristics of effective and efficient hypermedia presentations that are important for consideration by educators in developing and/or selecting such presentations. Definitions of hypertext, hypermedia, and multimedia are provided, and the relationships among these terms are described. Four other terms useful to…

Lewis, Wiley B.; Jansen, Duane G.

278

Behavioural characteristics of rapists  

Microsoft Academic Search

A substantial proportion of past research on rapists has focused on their motives. This paper reports on two studies that investigated the behavioural characteristics of rapists. The first study gathered behavioural data from police rape files to determine the types of behaviours exhibited by 130 men charged with rape. The second study was designed to validate the behavioural clusters found

Marita P. McCabe; Michelle Wauchope

2005-01-01

279

Profiling Freshman Academic Characteristics.  

ERIC Educational Resources Information Center

An academic characteristics profile database for freshmen at the Pennsylvania State University is briefly described. The database was constructed through the Freshman Testing, Counseling, and Advising Program (FTCAP), which is designed to assist new freshmen in evaluating their educational plans by providing them, prior to initial registration, a…

Kelly, James J.; White, Eric R.

280

Thermal counterflow experiments on superfluid helium at temperatures close to T/sub lambda/  

SciTech Connect

We have studied the relation between the heat-current density W and the temperature gradient delT in the laminar, turbulent, and transition regions in superfluid helium for temperatures close to T/sub lambda/ in channels of circular cross section. For temperatures T/sub lambda/-T<0.05 K, we do find simple exponentional relationships. In the turbulent region, W/delT is independent of channel diameter and is proportional to (T/sub lambda/-T)/sup 0.85/. The critical heat flow W/sub c/ is proportional to (T/sub lambda/-T)/sup ..beta../ with ..beta.. = -0.75 +- 0.05. For the diameter (d) dependence of W/sub c/, we found W/sub c/proportionald/sup ..nu../, with ..nu.. = -0.80 +- 0.03. The transition from the linear region to the turbulent region is very steep but not discontinuous. In the transition region the characteristic times related to the buildup of the turbulence become extremely long, especially for the narrowest channel and for T close to T/sub lambda/.

Dorscheidt, A.G.F.; van Kempen, H.; Wyder, P.; Frederking, T.H.K.

1985-05-01

281

On recent developments in marginal separation theory  

PubMed Central

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 , 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

Braun, S.; Scheichl, S.

2014-01-01

282

On recent developments in marginal separation theory.  

PubMed

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

Braun, S; Scheichl, S

2014-07-28

283

Experimental study of resonant interactions of instability waves in self-similar boundary layer with an adverse pressure gradient: II. Detuned resonances*  

NASA Astrophysics Data System (ADS)

This experimental study is of the initial nonlinear stages of the laminar-turbulent transition of a self-similar boundary layer with an adverse pressure gradient (Hartree parameter ßH?=?-0.115). All measurements were performed at controlled disturbance conditions at various initial spectra of excited 3D (in general) instability waves. The results are presented in three papers: part 1 (Borodulin V I, Kachanov Y S and Koptsev D B 2002 J. Turbulence3 062), part 2 (this paper), and part 3 (Borodulin V I, Kachanov Y S and Koptsev D B 2002 J. Turbulence3 064). The experimental procedure, the basic flow characteristics, the disturbance generator, the regimes of measurements (related to all parts), and the results of measurements obtained in cases of tuned resonant interactions of Tollmien Schlichting (TS) waves are presented in part 1. The results of investigation of resonant amplification of broadband, continuous-spectrum instability waves (random in time and space), which simulate some background perturbations, are described in part 3.

Borodulin, V. I.; Kachanov, Y. S.; Koptsev, D. B.; Roschektayev, A. P.

2002-12-01

284

Telling Time  

NSDL National Science Digital Library

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 ...

Lerdahl, Miss

2010-01-26

285

Black time … white time: My time … your time  

Microsoft Academic Search

Indigenous time began with the Era of Creation. White time began with the invention of the calendar, sundial and clock. White time was, and still is, influenced by the calendar, clock or watch. Time to go to sleep, time to get up, time to go to work...go home, time for dinner and time to watch the football or cricket. Even

Yalmambirra

2000-01-01

286

Shape Characteristics Analysis for Papaya Size Classification  

Microsoft Academic Search

Prior to export, papaya are subjected to inspection for the purpose of quality control and grading. For size grading, the fruit is weighed manually hence the practice is tedious, time consuming and labor intensive. Therefore, this paper will discuss the development of a computer vision system for papaya size grading using shape characteristic analysis. The methodology involves data acquisition to

Slamet Riyadi; A. A. A. Rahni; M. M. Mustafa; A. Hussain

2007-01-01

287

Aerodynamic characteristics of the Fiat UNO car  

Microsoft Academic Search

The purpose of this article is to describe the work conducted in the aerodynamic field throughout the 4-year development and engineering time span required by the project of the UNO car. A description is given of all the parametric studies carried out. Through these studies two types of cars at present in production were defined and the characteristics of a

Costelli

1984-01-01

288

Coplanar stripline propagation characteristics and bandpass filter  

Microsoft Academic Search

In this paper, a coplanar stripline bandpass filter is developed. The propagation characteristics of the coplanar stripline used for the construction of the filter are presented in the form of phase constant and attenuation constant. The filter is characterized experimentally as well as theoretically by use of the finite-difference time-domain (FDTD) technique. The agreement between the measured and modeled filter

Kavita Goverdhanam; Rainee N. Simons; Linda P. B. Katehi

1997-01-01

289

Advanced turboprop vibratory characteristics  

NASA Technical Reports Server (NTRS)

The assembly of SR5 advanced turboprop blades to develop a structural dynamic data base for swept props is reported. Steady state blade deformation under centrifugal loading and vibratory characteristics of the rotor assembly were measured. Vibration was induced through a system of piezoelectric crystals attached to the blades. Data reduction procedures are used to provide deformation, mode shape, and frequencies of the assembly at predetermined speeds.

Srinivasan, A. V.; Fulton, G. B.

1984-01-01

290

Characteristics of healthcare wastes  

SciTech Connect

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.

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

291

The First Time  

ERIC Educational Resources Information Center

In this article, the author narrates her experience of meeting a Montessori kid for the first time and shares the characteristics she observed in Montessori students. The author was working as director of academic resources in university housing at the University of Wisconsin-Madison and met Jason, a pre-med sophomore who was the resident…

Black, Beth

2011-01-01

292

Correlating Aluminum Burning Times  

Microsoft Academic Search

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,

M. W. Beckstead

2005-01-01

293

Penetration electric fields: Efficiency and characteristic time scale  

Microsoft Academic Search

Penetration of the interplanetary electric field (IEF) to the middle- and low-latitude ionosphere has been investigated for nearly four decades. Most previous studies focused on the correlation between the interplanetary and ionospheric electric field perturbations. Very little attention has been paid to a quantitative relationship except for a recent case analysis by Kelley et al. [2003. Penetration of the solar

Chao-Song Huang; Stanislav Sazykin; Jorge L. Chau; Naomi Maruyama; Michael C. Kelley

2007-01-01

294

Fixed-time life tests based on fuzzy life characteristics  

NASA Astrophysics Data System (ADS)

This paper deals with a reliability demonstration test with type-I censoring and presents a formulation based on fuzzy-set theory. Acceptable and rejectable MTBFs are represented in terms of a fuzzy concept, and Bayes' theorem plays an important role in the formulation. The proposed life test is useful when it is difficult to specify acceptable and rejectable MTBFs strictly.

Kanagawa, Akihiro; Ohta, Hiroshi

1992-06-01

295

Fibre Optic Sensors for Selected Wastewater Characteristics  

PubMed Central

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

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

2013-01-01

296

Seasonal Characteristics of Light  

NSDL National Science Digital Library

This module introduces students to the seasonal characteristics of light and its effects on Earth and living systems. It consists of a set of lessons in which they conduct direct hands-on field and laboratory investigations using graphing calculators and other scientific equipment. The activities are grouped by topic: life sciences, physical sciences, and mathematics. Students will use spreadsheet and modeling software to investigate how Earth's rotation around the sun affects light intensity, angle, and the Earth-Sun distance; and its effects on plants and animals, by collecting, modeling, and analyzing data.

297

Wave Types and Characteristics  

NSDL National Science Digital Library

This is the first in a series of new marine meteorology modules based on COMET’s old laser disk and CD-ROM modules on marine meteorology. This module is an introduction to waves and their associated characteristics. Several types of waves are presented, from the common wind wave to the rare tsunami wave. The basic physical, mathematical, and statistical traits of waves are discussed, along with how they change once waves become swell. This material serves as a building block to subsequent modules on wave generation, propagation, and dispersion.

COMET

2003-07-31

298

Gender, work roles and psychosocial work characteristics as determinants of health  

Microsoft Academic Search

This paper aims to identify gender similarities and differences in psychosocial work characteristics for those in and out of paid employment, to inform research on possible health-related effects. Specifically five questions are addressed: do women report poorer work characteristics than men; are gender differences related to specific characteristics; do work characteristics differ between full- and part-time women workers and between

Sharon Matthews; Clyde Hertzman; Aleck Ostry; Chris Power

1998-01-01

299

SYMBOLS FOR TIME = time variable  

E-print Network

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

Duchowski, Andrew T.

300

Letter-Matrix of Compact Representation of two-Dimensional Data Multitude for Visualization of Modal Parameters' Time-History With Implication to Seismic Survey of Life-Time and Characteristics of Excited Modal States of a Wide Range of Dynamic Structures  

NASA Astrophysics Data System (ADS)

The PSWT technique assumes definition of modal parameters on the basis of modal differential equation by processing of a segment of seismic response with stationary properties by a set of modulate functions. Thus, calculating necessary convolution integrals in the limits of the time-window with a modulate function and its claimed derivatives fixed within the window with zero values on its edges and having a limited transparent spectral window, a system of algebraic equation regard to looking for parameters can be formed. Leading correct conception of moving window analysis, total parametric scanning of the records in both time and frequency domains when the time-window should be moving by a certain step while varying its width in some boundaries that corresponds to shifting the spectral window in frequency domain allowing to find dominant filtration of the fundamental mode, should be proceeded. Revealed time segments with steady series of parameters' estimations are evidence of stationary of the modal state and that trial estimations are true, otherwise, non-stationary of dynamic properties and, or ill-filtration on some segments are the cause of the series of estimations to be dispersed. Final numeric output of the scanning require a vast storage paper space and it is time consuming of its graphic representation and interpretation. But the following idea allows the representation to be a completely formalized one. Thus, the numeric multitude of estimations should be grouping for each parameter and represented by corresponding compact symbolic, letter fields. Symbolic conform representation can be accomplished by assuming a quantum symbolic scale limited by accepted set of 53 symbols: +ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!?#$%&@(/{<|>})*- which is coherent to appropriate domain of continuous numeric measure scale of each parameter estimations' multitude. A certain step is admitted for quantization, and a respective symbol is assigned in sequence to each quantum unit. All numbers which fall within particular unit of the scale should be represented by the unit's symbol, numbers out of scale by + -. Therefore, the output would be a Letter-Matrix of Parametric Scanning of Seismogram, accompanying with deciphering formula, the means of visualization of life-time of stationary states. Zaurov 1977, 1994, 2011.

Zaurov, D.

2013-12-01

301

TIMED Doppler Interferometer  

NASA Technical Reports Server (NTRS)

The Timed Doppler Interferometer (TIDI) will accurately and precisely determine the global vector MLTI (Mesosphere and Lower Thermosphere) wind, temperature, and density profiles. It will measure characteristics of the gravity wave and planetary wave spectra. The tidal characteristics of temperature, density, and wind in the MLTI will be determined. The neutral and ion winds will be measured to characterize the electrodynamical behavior of the MLTI. Oxygen and O2 abundances and nocticulent cloud activity will be measured. This review goes into the calibration and error sources, optical design, mechanisms design, detector design, electronics design, microprocessor and flight software design, and quality assurance and parts.

Killeen, Timothy L. (Principal Investigator)

1995-01-01

302

Video Game Structural Characteristics: A New Psychological Taxonomy  

Microsoft Academic Search

Excessive video game playing behaviour may be influenced by a variety of factors including the structural characteristics\\u000a of video games. Structural characteristics refer to those features inherent within the video game itself that may facilitate\\u000a initiation, development and maintenance of video game playing over time. Numerous structural characteristics that influence\\u000a gambling frequency and expenditure have been identified in the gambling

Daniel King; Paul Delfabbro; Mark Griffiths

2010-01-01

303

Modeling Pulse Characteristics in Xenon with NEST  

E-print Network

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.

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

2013-01-01

304

Patient experience of time duration: strategies for 'slowing time' and 'accelerating time' in general practices.  

PubMed

Approaches to time management in general practices characteristically focus on objective 'clock time', for example, through appointment scheduling. No less important, however, is how patients experience time duration. Time is experienced as having passed slowly (time prolongation), quickly (time compression) or in rough synchronization with clock time. Duration has been theorized to be positively associated with information processing. This paper builds on that theory to suggest how practices can influence patients' subjective experience of duration in the practice environment, for example, by making waiting times appear to quicken and consultations appear to slow. PMID:14731148

Buetow, Stephen

2004-02-01

305

Large system interaction characteristics of superconducting generators  

NASA Astrophysics Data System (ADS)

The objective of this paper is to 'set the agenda' with respect to system interaction characteristics of superconducting generators. It identifies and highlights differences between these and conventional machines and shows ways in which superconducting machines will offer both advantages and problems. Superconducting generators, which are under development in several countries, including U.S., Germany, and Japan, will have system interaction characteristics somewhat different from those of their conventional counterparts. In general, the low reactances and long time constants of superconducting machines will improve transient stability and voltage regulation, but these will also produce large fault currents and torques. If care is not taken, these machines may produce destructive resonant effects on shaft lines. In this paper we build simple models that make it possible to discuss and understand several important system integration characteristics of synchronous machines, including the differences between conventional and superconducting machines. These include reactive power capability, transient stability, damping, voltage control, fault currents, and torques.

Kirtley, James L., Jr.

1993-03-01

306

[Mechanical buffering characteristics of feline paw pads].  

PubMed

In the long time of natural evolution, the bodies of some animals, such as feline, that live in the wild and complicate surroundings have evolved to possess outstanding buffering characteristics, which make the animals adapt to the environment perfectly. These animals generally have well-developed paw pads under their soles to play an important role in attenuating the intensity of impact when they land on the ground. Investigating the buffering characteristics of these animals' paw pads could help us to design "bionic" buffering and energy-absorption devices. In this paper, based on observations of animal jumping test, a simple mass-spring-buffer model was proposed to explore the buffering characteristics of the animals' paw pads. By analytically solving the differential equations of this model, the parameters concerned with paw pads functions were discussed and some significant results were obtained. PMID:23469538

Zhang, Xiaopeng; Yang, Jialing; Yu, Hui

2012-12-01

307

Matter wave pulses characteristics  

E-print Network

We study the properties of quantum single-particle wave pulses created by sharp-edged or apodized shutters with single or periodic openings. In particular, we examine the visibility of diffraction fringes depending on evolution time and temperature; the purity of the state depending on the opening-time window; the accuracy of a simplified description which uses ``source'' boundary conditions instead of solving an initial value problem; and the effects of apodization on the energy width.

A. del Campo; J. G. Muga

2005-06-14

308

SEXTANT 151 Characteristic A B C D E F G  

E-print Network

SEXTANT 151 Characteristic A B C D E F G SEXTANT yes yes yes yes yes yes yes/no Table 9.1: Linguistic characteristics which can be detected by the SEXTANT Parser. See Table 9.2 for an explanation, we used our original SEXTANT parser on the IPSM'95 test beds. Due to time constraints, we only

Sutcliffe, Richard

309

Video Game Structural Characteristics: A New Psychological Taxonomy  

ERIC Educational Resources Information Center

Excessive video game playing behaviour may be influenced by a variety of factors including the structural characteristics of video games. Structural characteristics refer to those features inherent within the video game itself that may facilitate initiation, development and maintenance of video game playing over time. Numerous structural…

King, Daniel; Delfabbro, Paul; Griffiths, Mark

2010-01-01

310

8-, 16-, and 32-Bit Processors: Characteristics and Appropriate Applications.  

ERIC Educational Resources Information Center

Defines and describes the components and functions that constitute a microcomputer--bits, bytes, address register, cycle time, data path, and bus. Characteristics of 8-, 16-, and 32-bit machines are explained in detail, and microprocessor evolution, architecture, and implementation are discussed. Application characteristics or types for each bit…

Williams, James G.

1984-01-01

311

Anthropometric characteristics evolution in elite rhythmic gymnasts.  

PubMed

The aims of this research were to assess anthropometric characteristics of high-level senior and junior rhythmic gymnasts; and was to investigate the changes of anthropometric characteristics over a 4 years period, in different senior and junior groups of the same technical level. Twenty anthropometric variables of 63 participants were collected and body composition and sitting-height-to-stature-ratio measures were calculated. The two-way (gymnast category and time) ANOVA of the anthropometric characteristics showed significant main effect of time period for biacromial and bicristal diameters indicating that the majority of variables had similar values in 2002 and 2006. A significant main effect of category (junior or senior) was present in most the analyzed variables with higher values in senior gymnasts than juniors. The significant category by time interaction for height, weight, limbs' length, and fat-free mass, indicated that some differences between junior and senior gymnasts increased over the 4 yr time period. The training hours per week were significantly higher in seniors, but did not differ over the 4 yr period. The study shows that the criteria, followed for the recruitment of elite gymnasts, in the two different periods considered (2002 and 2006) were almost the same. Moreover, higher differences between seniors and juniors of FFM values in 2006 indicated the more intensive training of the second period for seniors. PMID:18491452

di Cagno, Alessandra; Baldari, Carlo; Battaglia, Claudia; Guidetti, Laura; Piazza, Marina

2008-01-01

312

Wafer characteristics via reflectometry  

DOEpatents

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.

Sopori, Bhushan L. (Denver, CO)

2010-10-19

313

Growth Characteristics of Organisms  

NASA Astrophysics Data System (ADS)

In this chapter a systems viewpoint is taken of the growth characteristics of normal and malignant tissue. We find that such growth is well analyzed by the concepts of Shannon and Fisher information. In Section 3.1 conventional mechanisms of information transmission via DNA, RNA, and proteins are identified, as well as unconventional structures such as lipids and ion gradients. Information storage, flow, and utilization are analyzed, both within cells and over a system of cells. In Section 3.2, malignant tissue growth is found to be accurately described by the use of Fisher information in particular. Cancer growth is seen to occur as a disease of information, in fact an information catastrophe due to the regression of cells to a minimally ordered state consistent with life. The analysis yields many predictions about the growth of healthy tissue and cancerous tissue, some of which are nonintuitive and have a strong bearing on cancer diagnosis and treatment.

Gatenby, Robert A.; Frieden, B. Roy

314

Fracture characteristics in weathered granites  

NASA Astrophysics Data System (ADS)

The variability of weathered materials is an important factor in the geotechnical characterization of rock for engineering purposes. Most engineering rock mass classifications include weathering schemes that separate the weathering profile into zones or grades that depend upon the engineering and geological properties of the rock. Many geotechnical characteristics, including weathering, are controlled by the density and arrangement of fractures within the rock, but the relationships between fracture patterns and weathering grades are typically not addressed. Fracture characteristics were investigated in 13 exposures in five study areas in weathered granite in eastern Asia. All weathering grades were present, but never in the same exposure. Two approaches were used to evaluate the field data: (1) joint spacings were tabulated and examined within each weathering grade (tabulated classification); and (2) each exposure was classified according to the dominant weathering grade (visual classification). Mean and median joint spacings and joint spacing frequency distributions were analyzed and compared statistically for each approach. The box fractal dimensions for joint spacing were calculated for exposures classified visually in each weathering grade. Three-dimensional models of fresh and weathered granite were also generated and sampled for comparison to the field data. Mean joint spacing is usually 25% or more closer in weathered granite than it is in fresh granite, and the difference between the mean spacings for weathered granite and fresh granite tend to be statistically significant. There are no significant differences between any distribution medians. The joint spacing distributions for weathered granite and fresh granite are also not statistically significantly different, and there are no significant differences among the joint spacing frequency distributions for the different grades of weathered granite. Fractal analysis of joint spacings, however, suggests spacing characteristics of fresh and slightly weathered (SW) granite are very different from those in moderately, highly, and completely weathered granite, and sampling of three-dimensional models for weathered and fresh granite supports this. In an engineering context, this suggests that joint spacing relationships in the various grades of weathered granite can be treated as the same regardless of weathering grade and that joint patterns in fresh granite must be evaluated separately. This knowledge could result in significant time and cost savings in the geotechnical characterization of these materials.

Ehlen, Judy

1999-12-01

315

Screen heat exchanger performance comparison  

NASA Astrophysics Data System (ADS)

The performance of stainless steel screen regenerator stacks (500 mesh) has been investigated at relatively small flow rates in comparison to conventional operation close to the laminar-turbulent transition range. A modified 'single blow' technique was used initially, and an additional comparative procedure is employed to deduce heat transfer rate ratios with respect to a single-wire reference case of heat transfer. The data obtained are two orders of magnitude below 'classical' room temperature values at low Reynolds number (Re); (Re based on the Darcy law-related characteristic length; Re less than 1). The fluid is cold nitrogen from a liquid bath at atmospheric pressure.

Luna, J.; Ravikumar, K. V.; Frederking, T. H. K.

316

Adaptive mesh refinement for characteristic grids  

NASA Astrophysics Data System (ADS)

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 and Lehner (J Comp Phys 198:10, 2004), recurses on individual "diamond" characteristic grid cells. This leads to the use of fine-grained memory management, with individual grid cells kept in two-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 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 second and fourth 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.

Thornburg, Jonathan

2011-05-01

317

Job characteristics: their relationship to job satisfaction, stress and depression  

PubMed Central

This study investigated the influences of job characteristics on job satisfaction, stress and depression among South African white collar workers. Participants were managers in full-time employment with large organisations. They completed the Job Diagnostic Survey, the Perceived Stress Scale and the Beck Depression Inventory. A regression approach was used to predict job satisfaction, stress and depression from job characteristics. Job characteristics (skill variety, task identity, task significance, autonomy and feedback) predicted job satisfaction, as well as stress and depression. Job characteristics are weak predictors of perceived stress and depression. Work related factors, such as interpersonal relations and organisational culture, may better predict mental health in work settings.

Steyn, Renier; Vawda, Naseema

2015-01-01

318

Seismic Pulses Derivation from the Study of Source Signature Characteristics  

SciTech Connect

This paper deals with a deterministic technique for the derivation of seismic pulses by the study of source characteristics. The spectral characteristics of the directly or the nearest detected seismic signal is analyzed and considered as the principle source signature. Using this signature seismic pulses are derived with accurate time position in the seismic traces. The technique is applied on both synthetic and field refraction seismic traces. In both cases it has estimated that the accurate time shifts along with amplitude coefficients.

Rahman, Syed Mustafizur; Nawawi, M. N. Mohd.; Saad, Rosli [School of Physics, Univeristi Sains Malaysia, 11800 USM, Pulau Pinang (Malaysia)

2010-07-07

319

Radiographic amplifier screens: Fabrication process and characteristics  

NASA Technical Reports Server (NTRS)

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.

Szepesi, Z. P.

1977-01-01

320

Wetting Characteristics of Immiscibles  

NASA Technical Reports Server (NTRS)

Early microgravity experiments with immiscible alloys were usually carried out with the intent of forming dispersed microstructures. By processing under microgravity conditions, the main mechanism leading to gross phase separation could be eliminated. However, analysis of flight samples revealed a separated structure where the minor phase was present along the outer surface, while the major phase was present in the center. The Wetting Characteristics of Immiscibles (WCI) project, which flew aboard the USMP-4 (United States Microgravity Payload) mission in November of 1997, was designed to gain insight into the mechanisms causing segregation of these alloys. This investigation utilized an immiscible transparent organic alloy system and a transparent container in order to facilitate direct observation of the separation process. A range of immiscible alloy compositions was utilized in order to obtain variations in the minor and major phases present and observe the influence on the segregation processes. A small composition range was found where the minor liquid phase perfectly wet the cell gasket. Unexplained observations were made at the extremes of the composition range.

Andrews, J. B.; Little, L. J.

1999-01-01

321

Arcjet load characteristics  

NASA Technical Reports Server (NTRS)

Experiments were conducted to define the interface characteristics and constraints of 1 kW class arcjets run on simulated decomposition products of hydrazine and power processors. The impacts of power supply output current ripple on arcjet performance were assessed by variation of the ripple frequency from 100 Hz to 100 kHz with 10 percent peak-to-peak ripple amplitude at 1.2 kW. Ripple had no significant effects on thrust, specific impulse or efficiency. The impact of output ripple on thruster lifetime was not assessed. The static and dynamic impedances of the arcjet were quantified with two thrusters of nearly identical configuration. Superposition of an AC component on the DC arc current was used to characterize the dynamic impedance as a function of flow rate and DC current level. A mathematical model was formulated from these data. Both the static and dynamic impedance magnitude were found to be dependent on mass flow rate. The amplitude of the AC component was found to have little effect on the dynamic impedance. Reducing the DC level from 10 to 8 amps led to a large change in the magnitude of the dynamic impedance with no observable phase change. The impedance data compared favorably between the two thrusters.

Hamley, John A.

1990-01-01

322

Reaction times  

Microsoft Academic Search

Reviews 11 studies dealing with reaction times (1910-1911). Reaction time has been utilized to study a variety of problems. The studies indicate that accurate results can not be obtained without careful attention to the technique of the method of reaction time. The topics covered include effect of intensity of stimulus on reaction time, rapidity of perception of sound and light

Herbert Woodrow

1911-01-01

323

Virtual time  

Microsoft Academic Search

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,

David R. Jefferson

1985-01-01

324

Autoignition characteristics of no. 2 diesel fuel  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

325

Pharmacological characteristics of metamizole.  

PubMed

Metamizole (dipyrone) is a popular analgetic, non-opioid drug, commonly used in human and veterinary medicine. In some cases, this agent is still incorrectly classified as a non-steroidal anti-inflammatory drug (NSAID). Metamizole is a pro-drug, which spontaneously breaks down after oral administration to structurally related pyrazolone compounds. Apart from its analgesic effect, the medication is an antipyretic and spasmolytic agent. The mechanism responsible for the analgesic effect is a complex one, and most probably rests on the inhibition of a central cyclooxygenase-3 and activation of the opioidergic system and cannabinoid system. Metamizole can block both PG-dependent and PG-independent pathways of fever induced by LPS, which suggests that this drug has a profile of antipyretic action distinctly different from that of NSAIDs. The mechanism responsible for the spasmolytic effect of metamizole is associated with the inhibited release of intracellular Ca2+ as a result of the reduced synthesis of inositol phosphate. Metamizole is predominantly applied in the therapy of pain of different etiology, of spastic conditions, especially affecting the digestive tract, and of fever refractory to other treatments. Co-administration of morphine and metamizole produces superadditive, antinociceptive effects. Metamizole is a relatively safe pharmaceutical preparation although it is not completely free from undesirable effects. Among these side-effects, the most serious one that raises most controversy is the myelotoxic effect. It seems that in the past the risk of metamizole-induced agranulocytosis was exaggerated. Despite the evidence showing no risk of teratogenic and embryotoxic effects, the drug must not be administered to pregnant women, although it is allowed to be given to pregnant and lactating animals. This paper seeks to describe the characteristics of metamizole in the light of current knowledge. PMID:24724493

Jasiecka, A; Ma?lanka, T; Jaroszewski, J J

2014-01-01

326

Elapsed Time  

NSDL National Science Digital Library

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.

2007-01-01

327

Gases: Characteristics and Properties  

NSDL National Science Digital Library

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.

Brieske, Joel A.

328

Universal Time  

NSDL National Science Digital Library

This is a lesson plan for an activity that explores time zone math. Learners will translate their local time to times in other zones around the world and work with the concept of Universal Time, specifically in reference to the reporting, description and analysis of solar flares and coronal mass ejections. This is activity 10 from Exploring Magnetism Guide 3: Magnetic Mysteries of the Aurora educator guide.

329

A Taxonomy of Usability Characteristics  

E-print Network

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

Gabbard, Joseph L.

330

Characteristics of taste disorders.  

PubMed

Aim of this retrospective study was to obtain information about the frequency of taste disorders, their most frequent causes, and typical symptoms. A total of 491 out of 4,680 patients (presenting for the first time between 1998 and 2011) exhibited taste disorders (10.5 %). All patients underwent a thorough physical otorhinolaryngological examination including detailed assessment of smell and taste functions. The three most frequent causes of disorders were idiopathic (34 %), posttraumatic (24 %), and postoperative (15 %). Patients with idiopathic and postoperative taste disorders complained mainly about hypogeusia and parageusia; in comparison, patients with posttraumatic taste disorders exhibited a relatively higher degree of partial, local, or complete ageusia. Among patients with phantogeusia and parageusia, 38 % reported salty, and 22 % mixed sensations like bitter-salty or sour-sweet. In approximately 1/3 of this group of patients the cause of dysgeusia is unknown. Twenty-one percent of the patients complained of qualitative rather than quantitative taste problems. PMID:23229645

Fark, T; Hummel, C; Hähner, A; Nin, T; Hummel, T

2013-05-01

331

Modelling Time  

E-print Network

We briefly review two concepts of time - the usual time associated with "being" and more recent ideas, answering to the description of "becoming". The approximation involved in the former is examined. Finally we argue that it is (unpredictable) fluctuations that underlie time.

Burra G. Sidharth

2008-09-03

332

Geologic Time.  

ERIC Educational Resources Information Center

One of a series of general interest publications on science topics, the booklet provides those interested in geologic time with an introduction to the subject. Separate sections discuss the relative time scale, major divisions in geologic time, index fossils used as guides for telling the age of rocks, the atomic scale, and the age of the earth.…

Newman, William L.

333

Reaction Time  

NSDL National Science Digital Library

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.

Science, New Y.

1999-01-01

334

Telling Time  

NSDL National Science Digital Library

Help your child learn how to tell time on a digital and analog clock. Practice Telling Time with this fun game! Then, match the apple clock with the digital clock to show the correct Time! Finally, is it A.M. or P.M.? Practice with this fun game! ...

Popwell, Ms.

2010-10-03

335

Making Time  

ERIC Educational Resources Information Center

This article presents several tips that teachers can use to teach children about time. One activity, investigating 24-hour time, aims to familiarise upper primary students with converting a.m. and p.m. notations to 24-hour time. Another activity requires students to construct a calendar month in order to familiarize themselves with the components…

Gorham, Gail; Bobis, Janette

2005-01-01

336

Time Honoured  

ERIC Educational Resources Information Center

The vast majority of literature and practices in environmental education focuses on places and spaces. Little attention has been paid to time and temporalities as elements of environments, and the ways in which how we experience time affects our experience of place. This paper is an examination of the ways in which reflection on time can be…

Campbell, Mora; Timmerman, Peter

2007-01-01

337

Quantum Time  

E-print Network

Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do this, we generalize the paths in the Feynman path integral to include paths that vary in time as well as in space. We use Morlet wavelet decomposition to ensure convergence and normalization of the path integrals. We derive the Schr\\"odinger equation in four dimensions from the short time limit of the path integral expression. We verify that we recover standard quantum theory in the non-relativistic, semi-classical, and long time limits. Quantum time is an experiment factory: most foundational experiments in quantum mechanics can be modified in a way that makes them tests of quantum time. We look at single and double slits in time, scattering by time-varying electric and magnetic fields, and the Aharonov-Bohm effect in time.

John Ashmead

2010-05-05

338

[Characteristics of war wound infection].  

PubMed

War wounds are the most complex type of non-targeted injuries due to uncontrolled tissue damage of varied and multifold localizations, exposing sterile body areas to contamination with a huge amount of bacteria. Wound contamination is caused by both the host microflora and exogenous agents from the environment (bullets, cloth fragments, dust, dirt, water) due to destruction of the host protective barriers. War wounds are the consequence of destructive effects of various types of projectiles, which result in massive tissue devitalization, hematomas, and compromised circulation with tissue ischemia or anoxia. This environment is highly favorable for proliferation of bacteria and their invasion in the surrounding tissue over a relatively short period of time. War wounds are associated with a high risk of local and systemic infection. The infection will develop unless a timely combined treatment is undertaken, including surgical intervention within 6 hours of wounding and antibiotic therapy administered immediately or at latest in 3 hours of wound infliction. Time is a crucial factor in this type of targeted combined treatment consisting of surgical debridement, appropriate empirical antimicrobial therapy, and specific antitetanic prophylaxis. Apart from exposure factors, there are a number of predisposing factors that favor the development of polymicrobial aerobic-anaerobic infection. These are shock, pain, blood loss, hypoxia, hematomas, type and amount of traumatized tissue, age, and comorbidity factors in the wounded. The determinants that define the spectrum of etiologic agents in contaminated war wounds are: wound type, body region involved, time interval between wounding and primary surgical treatment, climate factors, season, geographical area, hygienic conditions, and patient habits. The etiologic agents of infection include gram-positive aerobic cocci, i. e. Staphylococcus spp, Streptococcus spp and Enterococcus spp, which belong to the physiological flora of the human skin and mucosa; gram-negative facultative aerobic rods; members of the family Enterobacteriacea (Escherichia coil, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter cloacae), which predominate in the physiological flora of the intestines, transitory flora of the skin and environment; gram-negative bacteria, i. e. Pseudomonas aeruginosa, Serratia marcescens, Acinetobacter calcoaceticus - A. baumanii complex; environmental bacteria associated with humid environment and dust; anaerobic gram-positive sporogeneous rods Clostridium spp, gram-negative asporogeneous rods Bacteroides spp and gram-positive anaerobic cocci; Peptostreptococcus spp and Peptococcus spp. The latter usually colonize the intestine, primarily the colon, and the skin, while clostridium spores are also found in the environment. Early empirical antibiotic therapy is used instead of standard antibiotic prophylaxis. Empirical antimicrobial therapy is administered to prevent the development of systemic infection, gas gangrene, necrotizing infection of soft tissue, intoxication and death. The choice of antibiotics is determined by the presumed infective agents and localization of the wound. It is used in all types of war wounds over 5-7-10 days. The characteristics of antibiotics used in war wounds are the following: broad spectrum of activity, ability to penetrate deep into the tissue, low toxicity, long half-life, easy storage and application, and cost effectiveness. The use of antibiotics is not a substitution for surgical treatment. The expected incidence of infection, according to literature data, is 35%-40%. If the time elapsed until surgical debridement exceeds 12 hours, or the administration of antibiotics exceeds 6 hours of wound infliction, primary infection of the war wound occurs (early infection) in more than 50% of cases. The keys for the prevention of infection are prompt and thorough surgical exploration of the wound, administration of antibiotics and antitetanic prophylaxis, awareness of the probable pathogens with respect to localization of the wound, and optimal choi

Kucisec-Tepes, Nastja; Bejuk, Danijela; Kosuta, Dragutin

2006-09-01

339

Timing analysis and conditional scheduling in a real-time system design environment  

Microsoft Academic Search

This paper presents an approach to carry out timing analysis and scheduling in a real-time system design environment for flexible manufacturing systems. It is built based on a formal model for specifying real-time systems using extended timed Petri nets. The designer uses the model to specify a design at a given level. The functional characteristics as well as timing properties

Zebo Peng; A. Torne

1994-01-01

340

Measuring spatial variability in soil characteristics  

DOEpatents

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.

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

341

Surface characteristics of thermally treated titanium surfaces  

PubMed Central

Purpose The characteristics of oxidized titanium (Ti) surfaces varied according to treatment conditions such as duration time and temperature. Thermal oxidation can change Ti surface characteristics, which affect many cellular responses such as cell adhesion, proliferation, and differentiation. Thus, this study was conducted to evaluate the surface characteristics and cell response of thermally treated Ti surfaces. Methods The samples were divided into 4 groups. Control: machined smooth titanium (Ti-S) was untreated. Group I: Ti-S was treated in a furnace at 300? for 30 minutes. Group II: Ti-S was treated at 500? for 30 minutes. Group III: Ti-S was treated at 750? for 30 minutes. A scanning electron microscope, atomic force microscope, and X-ray diffraction were used to assess surface characteristics and chemical composition. The water contact angle and surface energy were measured to assess physical properties. Results The titanium dioxide (TiO2) thickness increased as the treatment temperature increased. Additional peaks belonging to rutile TiO2 were only found in group III. The contact angle in group III was significantly lower than any of the other groups. The surface energy significantly increased as the treatment temperature increased, especially in group III. In the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, after 24 hours of incubation, the assessment of cell viability showed that the optical density of the control had a higher tendency than any other group, but there was no significant difference. However, the alkaline phosphatase activity increased as the temperature increased, especially in group III. Conclusions Consequently, the surface characteristics and biocompatibility increased as the temperature increased. This indicates that surface modification by thermal treatment could be another useful method for medical and dental implants. PMID:22803009

Lee, Yang-Jin; Cui, De-Zhe; Jeon, Ha-Ra; Chung, Hyun-Ju; Park, Yeong-Joon; Kim, Ok-Su

2012-01-01

342

Rainfall characteristics along mountainous transect  

NASA Astrophysics Data System (ADS)

The HYdrological cycle in Mediterranean EXperiment is an experiment framework that aims at improving our understanding and quantification of processes related to the hydrological cycle in the Mediterranean region at different scales (from the individual event scale to seasonal and inter-annual variability). During the Special Observation Period (SOP-1) conducted from September 5th to November 6th 2012, an important and complementary remote sensing network (operational radars, X band research radars, Micro Rain Radars, disdrometers, and a dense network of rain gauges) has been deployed in the Cévennes-Vivarais region (South of France). This network was specifically designed to investigate the structure and the heterogeneity of precipitations as well as, in particular, the impact of orography on this structure and it has provided us with high resolution data (time and space) along strong topographic gradients (small hills, foothills and mountain). Hence, these data will support our research to precisely describe the precipitation systems and their structures over a complex terrain. In this work, we will describe the characteristics of rainfall along two topographic gradients based on the major events observed during the fall 2012 campaign period. A classification according to the type of precipitation (convective, stratiform and orographic) which can affect the region has been made to investigate orographic impact under different rainfall regimes. We will also examine the influence of the relief on the vertical and horizontal structure of precipitation. In particular, we will illustrate the modification of the drop size distribution toward smaller droplets as we go from the small hills to the mountains.

Zwiebel, Jimmy; Van Baelen, Joël; Anquetin, Sandrine; Pointin, Yves; Boudevillain, Brice

2014-05-01

343

A Comparison of Bicyclists' Performance Characteristics at Urban, Suburban, and  

E-print Network

intersection. · Performance Characteristics Of This Research: ­ Perception/Reaction Time ­ Acceleration Rates - Video Unit Source Image: NACTO Urban Bikeway Design Guide #12;Performance Methodology · Perception/Reaction and performance varies significantly and has not been well quantified Outdated signal timing for bikes could

Bertini, Robert L.

344

Characteristics of Students Who Reenroll after Serving a Disciplinary Suspension  

ERIC Educational Resources Information Center

The purpose of this study was to examine if students who reenroll following a disciplinary suspension had significant common characteristics. Gender, GPA at time of suspension, class status at time of suspension, type of violation(s) that resulted in suspension, number of disciplinary incidents prior to suspension, and length of suspension were…

Stimpson, Matthew T.; Janosik, Steven M.

2007-01-01

345

Real time automated inspection  

DOEpatents

A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.

Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.

1985-05-21

346

The Physical Characteristics of Minerals  

NSDL National Science Digital Library

Offered by Amethyst Galleries, Inc. (an online minerals store), the Physical Characteristics of Minerals Web site offers a detailed description of how minerals are identified. Each page gives good information and examples of a particular characteristic (e.g, color, hardness, cleavage, feel, and taste). Also, on the first page are links to dozens of minerals that are categorized by name, class, interesting groupings, and great localities. These give the class, subclass, group, uses, physical characteristics, and sample photographs of that particular mineral. Anyone interested in geology, minerals, or gemstones will find this site very informative and fun to explore.

1998-01-01

347

Simulation and Experimental Investigation of Structural Dynamic Frequency Characteristics Control  

PubMed Central

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

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

2012-01-01

348

Time Machine  

NSDL National Science Digital Library

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.

Larry Flammer

349

Geologic Time  

NSDL National Science Digital Library

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.

Newman, William L.

1997-01-01

350

Geologic time  

USGS Publications Warehouse

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.

Newman, William L.

2000-01-01

351

Clock Time  

NSDL National Science Digital Library

You will have practice reading the time on a clock and pairing it up with its digital or written text match. Complete this as quickly as you can in order to beat the clock! Stop the Clock 1 Stop the Clock 2 Stop the Clock 6 Each of these links varies in degree of difficulty. They progressively go up in difficulty in the time you are telling. The first starts out telling time in half hour intervals. The following activity progress to fifteen minutes. The final activity is matching up the time on the clock to ...

Miss Greene

2010-04-26

352

Time interpolator  

NASA Astrophysics Data System (ADS)

A time interpolator for the measurement of time difference using digital and analog techniques is described. Emitter Coupled Logic (ECL) and high frequency techniques were used. The difficulty with ECL is to keep the connections as short as possible and to properly terminate the output to avoid reflections. The digital part of the interpolator consists of a continuous clock and logic which converts the input signal into a start and stop signal. The analog part consists of a time to amplitude converter and an analog to digital convertor. The maximum measuring time is 6.4 microns with a 100 ps resolution.

Deblok, M.

1990-06-01

353

CHARACTERISTICS OF THE BLOOD OF ADULT PINK SALMON AT THREE STAGES OF MATURITY  

E-print Network

on changes in blood characteristics at this time of the life cycle. Lysaya (1951) found several physiologicalCHARACTERISTICS OF THE BLOOD OF ADULT PINK SALMON AT THREE STAGES OF MATURITY By KENNETH E. HUTTON characteristics of the blood of adult pink salmon (Oncorhynchus gorbuschtl) were studied in fish at three stages

354

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.

2008-04-17

355

Virtual Time  

Microsoft Academic Search

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

David Jefferson

1983-01-01

356

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 ...

357

Various characteristic of Carbon nanotubes film methane Gas sensor  

Microsoft Academic Search

Various sensing characteristic of carbon nanotube synthesized by low press chemical vapor deposit (LPCVD) method have been studied. The composite sensing film of silicon dioxide and multi-wall nanotubes (SiO 2-MWNTs) is sensitive to methane. The various characteristic such as sensitivity, repeatability, reliability and cross-sensitivity of SiO2-MWNTs composite film gas sensor have been studied. Having been tested in methane 3 times,

Xin Li; Junhua Liu; Changchun Zhu

2006-01-01

358

IRRADIATION EFFECTS ON THE PHYSICAL CHARACTERISTICS OF SEWAGE SLUDGE  

SciTech Connect

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.

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

2004-10-05

359

Characteristics of Populations (title provided or enhanced by cataloger)  

NSDL National Science Digital Library

The concept that populations are dynamic with identifiable characteristics and measurable growth patterns is addressed in this lesson plan. Population characteristics are explained, including biotic potential, density, natality, mortality, and age distribution. The lesson plan provides objectives, skills, time needed, a content outline, materials, significant terms, and questions for the class. The main goal of the lesson plan is for students to develop an understanding of the interdependence of all organisms and the need for conserving natural resources.

360

Time Clocks  

NSDL National Science Digital Library

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.

Greb, Stephen

361

Screen Time  

NSDL National Science Digital Library

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.

Omsi

2007-01-01

362

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.

363

Characterization and characteristics of degradable polymer sacks  

SciTech Connect

This paper reviews the categories and characteristics of degradable polymers used to manufacture sacks for the collection and subsequent treatment of organic wastes from householders. The characteristics of polyethylene (PE) and starch-based sacks were examined using a number of different methods, including scanning electron microscopy (SEM), chemical analysis and mechanical strength testing of the sacks during their use. The analyses revealed that the characteristics of the PE and starch-based sacks were very different. Photomicrographs indicated that the surface of the PE sack was much smoother than the surface of the starch-based sacks. Polyethylene sacks exhibited a greater mechanical strength, both in the unused state and over time during householder use. The severe loss of mechanical strength during use of the starch-based sacks indicated that only thicker gauge sacks were suitable for the fortnightly kerbside collection of biodegradable municipal waste (BMW). Chemical analysis of two different PE sacks indicated that transition metals and other elements were commonly incorporated into the PE structure in order to facilitate increased polymer degradation.

Davis, Georgina

2003-10-15

364

[Characteristics analysis of human tongue reflectance spectra].  

PubMed

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

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

2014-08-01

365

[Characteristics analysis of human tongue reflectance spectra].  

PubMed

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

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

2014-08-01

366

Pulsar Timing Arrays  

NASA Astrophysics Data System (ADS)

In the last decade, the use of an ensemble of radio pulsars to constrain the characteristic strain caused by a stochastic gravitational wave background has advanced the cause of detection of very low frequency gravitational waves (GWs) significantly. This electromagnetic means of GW detection, called Pulsar Timing Array (PTA), is reviewed in this paper. The principle of operation of PTA, the current operating PTAs and their status are presented along with a discussion of the main challenges in the detection of GWs using PTA.

Joshi, Bhal Chandra

2013-01-01

367

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- ...

368

Time Management  

NSDL National Science Digital Library

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.

MindTools (MindTools)

2012-01-20

369

Creative Time  

NSDL National Science Digital Library

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.

2012-08-31

370

Bleeding time  

MedlinePLUS

Bleeding time is a blood test that looks at how fast small blood vessels in the skin close to stop you from bleeding. ... deep enough to cause a tiny amount of bleeding. The blood pressure cuff is immediately deflated. Blotting ...

371

Calibration of a ?- Re ? transition model and its application in low-speed flows  

NASA Astrophysics Data System (ADS)

The prediction of laminar-turbulent transition in boundary layer is very important for obtaining accurate aerodynamic characteristics with computational fluid dynamic (CFD) tools, because laminar-turbulent transition is directly related to complex flow phenomena in boundary layer and separated flow in space. Unfortunately, the transition effect isn't included in today's major CFD tools because of non-local calculations in transition modeling. In this paper, Menter's ?- Re ? transition model is calibrated and incorporated into a Reynolds-Averaged Navier-Stokes (RANS) code — Trisonic Platform (TRIP) developed in China Aerodynamic Research and Development Center (CARDC). Based on the experimental data of flat plate from the literature, the empirical correlations involved in the transition model are modified and calibrated numerically. Numerical simulation for low-speed flow of Trapezoidal Wing (Trap Wing) is performed and compared with the corresponding experimental data. It is indicated that the ?- Re ? transition model can accurately predict the location of separation-induced transition and natural transition in the flow region with moderate pressure gradient. The transition model effectively imporves the simulation accuracy of the boundary layer and aerodynamic characteristics.

Wang, YunTao; Zhang, YuLun; Meng, DeHong; Wang, GunXue; Li, Song

2014-12-01

372

About time  

NASA Technical Reports Server (NTRS)

Time has historically been a measure of progress of recurrent physical processes. Coordination of future actions, prediction of future events, and assigning order to events are three practical reasons for implementing clocks and signalling mechanisms. In large networks of computers, these needs lead to the problem of synchronizing the clocks throughout the network. Recent methods allow this to be done in large networks with precision around 1 millisecond despite mean message exchange times near 5 milliseconds. These methods are discussed.

Denning, Peter J.

1990-01-01

373

Wuda Time  

NSDL National Science Digital Library

The Wuda Time project management tool is designed to help individuals keep track of their dedication to various tasks and operations. Visitors can sign up right on the site to have instant access to this powerful tool. It's easy to use and users can prioritize certain tasks with a color-coded system or designate certain task completion times. This version is compatible with all operating systems.

374

Characteristics of magnetospheric radio noise spectra  

NASA Technical Reports Server (NTRS)

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 mid-frequency range (100-1,000 kHz) intense noise peaks rise by 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. This intense mid-frequency noise has been detected at radial distances from 1.3 Re to 60 Re on all sides of the Earth 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. ""Magnetospheric lightning'' can be invoked to explain the spectral shape of the observed spectra.

Herman, J. R.

1976-01-01

375

New Trends in Real Time Operating Systems  

Microsoft Academic Search

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

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

2012-01-01

376

A global evaluation of streamflow drought characteristics  

NASA Astrophysics Data System (ADS)

How drought is characterised depends on the region under study, the purpose of the study and the available data. In case of regional applications or global comparison a standardisation of the methodology is preferable. In this study several methods to derive streamflow drought characteristics are evaluated based on their application to daily streamflow series from a wide range of hydrological regimes. Drought deficit characteristics, such as drought duration and deficit volume, are derived with the threshold level method. When it is applied to daily time series an additional pooling procedure is required and three different pooling procedures are evaluated, the moving average procedure (MA-procedure), the inter event time method (IT-method), and the sequent peak algorithm (SPA). The MA-procedure proved to be a flexible approach for the different series, and its parameter, the averaging interval, can easily be optimised for each stream. However, it modifies the discharge series and might introduce dependency between drought events. For the IT-method it is more difficult to find an optimal value for its parameter, the length of the excess period, in particular for flashy streams. The SPA can only be recommended for the selection of annual maximum series of deficit characteristics and for very low threshold levels due to the high degree of pooling. Furthermore, a frequency analysis of deficit volume and duration is conducted based on partial duration series of drought events. According to extreme value theory, excesses over a certain limit are Generalized Pareto (GP) distributed. It was found that this model indeed performed better than or equally to other distribution models. In general, the GP-model could be used for streams in all regime types. However, for intermittent streams, zero-flow periods should be treated as censored data. For catchments with frost during the winter season, summer and winter droughts have to be analysed separately.

Fleig, A. K.; Tallaksen, L. M.; Hisdal, H.; Demuth, S.

2005-11-01

377

Time 100  

NSDL National Science Digital Library

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.

1998-01-01

378

Physicochemical characteristics of microbial granules.  

PubMed

Microbial granules play an important role in the field of biological wastewater treatment due to their advantages over the conventional sludge flocs, such as a denser and stronger aggregate structure, better settleability and ensured solid-effluent separation, higher biomass concentration, and greater ability to withstand shock loadings. A better understanding of microbial granules may help in engineering biological wastewater treatment systems. Recent studies have greatly expanded our vision over the physicochemical characteristics of microbial granules. This paper provides an up-to-date review on recent work in the understanding of physicochemical characteristics of both anaerobic and aerobic granules with regard to settleability, permeability, morphology, mechanical stability, rheology, porosity, surface adsorbability, surface hydrophobicity and thermodynamics, and extracellular polymeric substances. Our growing knowledge on such characteristics might facilitate the engineering and optimization of microbial granulation as one of the most promising techniques in biological wastewater treatment. PMID:19464355

Liu, Xian-Wei; Sheng, Guo-Ping; Yu, Han-Qing

2009-01-01

379

Characteristics of a numerical fluid dynamics simulator  

SciTech Connect

John von Neumann envisioned scientists and mathematicians analyzing and controlling their numerical experiments on nonlinear dynamic systems interactively. We describe our concept of a real-time Numerical Fluid Dynamics Simulator NFDS, and derive its characteristics adopting the following as guiding principles: (a) that the performance characteristics (information output, throughput and storage) of the NFDS be defined by the maximum rate at which the researcher can absorb the results of his/her simulation, thus establishing an impedance match between man and machine, (b) that the NFDS off-load from the researcher's brain in every way possible the routine tasks of data analysis that can be done automatically, and (c) that the NFDS is operated as a dedicated experimental device, much as a wind tunnel, and that the researcher has complete control over the apparatus and experiment. We envision the NFDS to be composed of simulation processors, data storage devices, and image processing devices of extremely high power and capacity, interconnected by very high throughput communication channels. We present individual component performance requirements for both real-time and playback operating modes of the NFDS, using problems of current interest in fluid dynamics as examples.

Winkler, K.H.A.; Norman, M.L.; Norton, J.L.

1985-01-01

380

Macroscopic characteristics of hacking trauma.  

PubMed

Hacking trauma is often encountered in forensic cases, but little experimental research has been conducted that would allow for the recognition of wounds caused by specific weapon types. In this paper, we report the results of a hacking trauma caused by machete, cleaver, and axe weapons and the characteristics of each weapon type on bone. Each weapon type was employed in multiple trials on pig (Sus scrofa) bones and then the wounds were examined macroscopically for several characteristics that serve to differentiate the weapons. PMID:11305423

Humphrey, J H; Hutchinson, D L

2001-03-01

381

Rhizosphere Characteristics of the Arsenic Hyperaccumulator Pteris  

E-print Network

Rhizosphere Characteristics of the Arsenic Hyperaccumulator Pteris vittata L. and Monitoring investigated changes in the rhizosphere characteristics of Pteris vittata (Chinese Brake fern) relevant for its

Ma, Lena

382

Reaction Time  

NSDL National Science Digital Library

In this activity, learners conduct an experiment to test how fast they can react. Learners try to catch a piece of paper with a ruler printed on it (or a ruler) as quickly as they can. Learners collect data and compare the reaction times of friends and family.

Boston, Wgbh

2003-01-01

383

Deep Time  

NSDL National Science Digital Library

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.

WPSU

2010-05-04

384

Reaction Time  

NSDL National Science Digital Library

This lab is not an inquiry activity. There are some students whose reaction times will not allow them to catch a 12 inch ruler. They may use a dowel, stick, strip of cardboard, etc. Although the students are led to believe that the point of the lab is to

Horton, Michael

2009-05-30

385

Geologic Time  

NSDL National Science Digital Library

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.

Heaton, Timothy

386

Geological Time  

Microsoft Academic Search

IN his Presidential Address to Section C at Dover, Sir A. Geikie has offered a bold challenge to Lord Kelvin and those who agree with him by calling upon them to give due weight to geological phenomena in forming an estimate of geological time. Permit me to say what I think about it.

O. Fisher

1899-01-01

387

Geosynchronous platform definition study. Volume 3: Geosynchronous mission characteristics  

NASA Technical Reports Server (NTRS)

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.

1973-01-01

388

ARTICLE / ARTICLE Rumenreticulum characteristics, scaling  

E-print Network

-tailed deer (Odocoileus virginianus) R.S. Luna, A. Duarte, and F.W. Weckerly Abstract: Scaling relationships­reticulum characteristics in white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) because little is known about how réticulo-rumen chez le cerf de Virginie (Odocoileus virginianus (Zimmermann, 1780)), puisque les

Aspbury, Andrea S. - Department of Biology, Texas State University

389

Supervisor Accessibility and Job Characteristics.  

ERIC Educational Resources Information Center

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…

Dallinger, Judith M.; Hample, Dale

390

Characteristics of Effective Instructional Technology.  

ERIC Educational Resources Information Center

Effective technology empowers learners and helps them assume responsibility for their own learning. Characteristics of effective instructional technology should guide the development of computer software and other types of technology. Software should provide for interaction since adults learn through active engagement. Feedback should be…

Bixler, Brett; Askov, Eunice N.

1994-01-01

391

Submarine Coaxial Cable Pressure Characteristics  

Microsoft Academic Search

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

K. Aida; M. Aiki

1978-01-01

392

Tourette's Syndrome: Characteristics and Interventions.  

ERIC Educational Resources Information Center

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.…

Prestia, Kelly

2003-01-01

393

Idiopathic Transverse Myelitis: MR Characteristics  

Microsoft Academic Search

PURPOSE: To describe the MR characteristics that can distinguish idiopathic transverse myelitis from other intramedullary lesions. METHODS: A total of 32 initial and follow-up MR studies in 17 patients with clinically proved transverse myelitis were reviewed retrospectively. The location, size, pattern, and segmental length of areas of hyperintensity were estimated on T2-weighted axial and sagittal images. In 15 of the

Kyu Ho Choi; Kwang Soo Lee; Sun Ok Chung; Jung Mee Park; Young Joo Kim; Hyun Sook Kim; Kyung Sub Shinn

394

Geometric Langlands in prime characteristic  

E-print Network

Let C be a smooth projective curve over an algebraically closed field k of sufficiently large characteristic. Let G be a semisimple algebraic group over k and let GV be its Langlands dual group over k. Denote by BunG the ...

Chen, Tsao-Hsien

2012-01-01

395

Characteristics and Uses for Ash  

E-print Network

Planes and east to the Atlantic Ocean, except the Florida peninsula and southern Canada Green Ash) #12;Physical Properties M.C./Drying 130Sycamore 106Yellow Poplar 69Red Oak 44White Ash Green SapwoodCharacteristics and Uses for Ash Daniel Cassens Department of Forestry and Natural Resources Purdue

396

Epidemiological characteristics of platelet aggregability  

Microsoft Academic Search

The epidemiological characteristics of platelet aggregability were established in 958 participants in the Northwick Park Heart Study. The main analyses were based on the dose of adenosine diphosphate at which primary aggregation occurred at half its maximum velocity. Aggregability increased with age in both sexes, was greater in whites than blacks (particularly among men), and tended to decrease with the

T W Meade; M V Vickers; S G Thompson; Y Stirling; A P Haines; G J Miller

1985-01-01

397

Handbook of sensor technical characteristics  

NASA Technical Reports Server (NTRS)

Space and terrestrial applications remote sensor systems are described. Each sensor is presented separately. Information is included on its objectives, description, technical characteristics, data products obtained, data archives location, period of operation, and measurement and potential derived parameters. Each sensor is cross indexed.

Tanner, S.

1982-01-01

398

Stationary plasma thruster plume characteristics  

Microsoft Academic Search

Stationary Plasma Thrusters (SPT's) are being investigated for application to a variety of near-term missions. This paper presents the results of a preliminary study of the thruster plume characteristics which are needed to assess spacecraft integration requirements. Langmuir probes, planar probes, Faraday cups, and a retarding potential analyzer were used to measure plume properties. For the design operating voltage of

Roger M. Myers; David H. Manzella

1994-01-01

399

Characteristics of the neurotically predisposed  

Microsoft Academic Search

A. F. Riggs lists the special characteristics of the so-called psychoneurotic as follows: (1) oversensitiveness to emotions and sensations; (2) relative imbalance of instincts; (3) suggestibility with a tendency to dissociation of function; and (4) character faults resulting in an egoistic type of maladaptation. This classification suggests a number of points which the writer discusses. Oversensitiveness may be used in

W. S. Taylor

1926-01-01

400

Computerized Investigations of Battery Characteristics.  

ERIC Educational Resources Information Center

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.…

Hinrichsen, P. F.

2001-01-01

401

Leadership Characteristics of Adult Educators  

Microsoft Academic Search

The purpose of this study was to assess self-perceived leadership behaviors and related leadership styles practiced in a sample of adult educators. Adopting transformational leadership theory embodied in the Full Range of Leadership Model the leadership characteristics of adult educators were examined using the Multifactor Leadership Questionnaire Form 5x (Bass & Avolio, 2000). The possibility of significant differences between respondent

Frederick P. Bartling; Kenneth R. Bartlett

402

Fatigue characteristics of metallic biomaterials  

Microsoft Academic Search

It is essential to determine the fatigue characteristics of metallic biomaterials for long-term safe usage of implants in living body such as hip joints, bone plates, and dental implants. On the basis of reported data, the fatigue strength, fretting fatigue strength, and fatigue crack propagation rate of metallic biomaterials – mainly titanium alloys, Co alloys, and stainless steels – in

M. Niinomi

2007-01-01

403

Plasticity characteristic obtained by indentation  

Microsoft Academic Search

A dimensionless parameter ?H = ?p\\/?t (where ?p and ?t are the average values of plastic and total deformation of material on the contact area indenter–specimen) may be used as the plasticity characteristic of materials, which made it possible to characterize the plasticity of materials that are brittle in standard mechanical tests. ?H may be calculated from the values of

Yu V Milman

2008-01-01

404

The Characteristics of Incestuous Fathers.  

ERIC Educational Resources Information Center

This research was designed to find out more about the characteristics of fathers who sexually abuse their daughters, with the goal of helping to prevent such abuse and to identify possibly high risk populations. The sample consisted of 118 recently identified incestuous biological fathers and a matched comparison group of 116 non-abusive…

Williams, Linda Meyer; Finkelhor, David

405

The prediction of airfoil characteristics  

NASA Technical Reports Server (NTRS)

This report describes and develops methods by which the aerodynamic characteristics of an airfoil may be calculated with sufficient accuracy for use in airplane design. These methods for prediction are based on the present aerodynamic theory and on empirical formulas derived from data obtained in the N. A. C. A. variable density wind tunnel at a Reynolds number corresponding approximately to full scale. (author)

Higgins, George J

1930-01-01

406

The DIII-D Computing Environment: Characteristics and Recent Changes  

SciTech Connect

The DIII-D tokamak national fusion research facility along with its predecessor Doublet III has been operating for over 21 years. The DIII-D computing environment consists of real-time systems controlling the tokamak, heating systems, and diagnostics, and systems acquiring experimental data from instrumentation; major data analysis server nodes performing short term and long term data access and data analysis; and systems providing mechanisms for remote collaboration and the dissemination of information over the world wide web. Computer systems for the facility have undergone incredible changes over the course of time as the computer industry has changed dramatically. Yet there are certain valuable characteristics of the DIII-D computing environment that have been developed over time and have been maintained to this day. Some of these characteristics include: continuous computer infrastructure improvements, distributed data and data access, computing platform integration, and remote collaborations. These characteristics are being carried forward as well as new characteristics resulting from recent changes which have included: a dedicated storage system and a hierarchical storage management system for raw shot data, various further infrastructure improvements including deployment of Fast Ethernet, the introduction of MDSplus, LSF and common IDL based tools, and improvements to remote collaboration capabilities. This paper will describe this computing environment, important characteristics that over the years have contributed to the success of DIII-D computing systems, and recent changes to computer systems.

McHarg, B.B., Jr.

1999-07-01

407

Time Traveler  

NSDL National Science Digital Library

This NOVA website simulates travel to distant stars and back in a spaceship that can move at various percentages of the speed of light. You set the spaceship speed and choose your destination star, and the simulation calculates the time of travel as measured on Earth and inside the spaceship. Text describes the "twin paradox" of the theory of relativity and also the 1971 test of its prediction using airliners and atomic clocks.

2011-10-15

408

Real-time flutter identification  

NASA Technical Reports Server (NTRS)

The techniques and a FORTRAN 77 MOdal Parameter IDentification (MOPID) computer program developed for identification of the frequencies and damping ratios of multiple flutter modes in real time are documented. Physically meaningful model parameterization was combined with state of the art recursive identification techniques and applied to the problem of real time flutter mode monitoring. The performance of the algorithm in terms of convergence speed and parameter estimation error is demonstrated for several simulated data cases, and the results of actual flight data analysis from two different vehicles are presented. It is indicated that the algorithm is capable of real time monitoring of aircraft flutter characteristics with a high degree of reliability.

Roy, R.; Walker, R.

1985-01-01

409

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

E-print Network

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

Suzuki, Masatsugu

410

Electrical properties and humidity sensor characteristics of lead hydroxyapatite material  

NASA Astrophysics Data System (ADS)

Crystalline lead hydroxyapatite is obtained by direct precipitation from aqueous solution, the method being easy, fast and reproducible. The synthesis route which does not involve sodium salts or sulfates makes the material suitable for applications in catalysis. The electrical characteristics of lead hydroxyapatite material treated at different temperatures, made us focus on the analysis of the influence of water vapors upon the electrical characteristics. Thus, the electrical response to humidity adsorptive processes of lead hydroxyapatite material suggested us to analyze the material characteristics in terms of its use as a humidity sensor. The hydrophilic properties of lead hydroxyapatite material are reflected especially in high sensitivity and reduced time of response of the humidity sensors but also in long time of recovery, which suggests that Pb10(PO4)6(OH)2 material can be used for humidity sensors specialized in monitoring fluctuating humidity environments.

Tudorache, Florin; Petrila, Iulian; Popa, Karin; Catargiu, Ana Maria

2014-06-01

411

Analysis of benchmark characteristics and benchmark performance prediction  

Microsoft Academic Search

Standard benchmarking provides to run-times for given programs on given machines, but fails to provide insight as to why those results were obtained (either in terms of machine or program characteristics) and fails to provide run-times for that program on some other machine, or some other programs on that machine. We have developed a machine-imdependent model of program execution to

Rafael H. Saavedra; Alan Jay Smith

1996-01-01

412

Acceleration of Computation of Determinants and Characteristic Polynomials without Divisions  

Microsoft Academic Search

Algorithms are proposed that compute determinants and characteristic polynomials of n × n matrices without divisions in \\u000a$$ \\\\leqslant \\\\frac{9}{7} \\\\cdot $$\\u000a·n3+1\\/2 ring operations and adjoint matrices in three times more ring operations.

T. R. Seifullin

2003-01-01

413

Computation of Determinants, Adjoint Matrices, and Characteristic Polynomials without Division  

Microsoft Academic Search

Algorithms are proposed for computing the characteristic polynomial, determinant, and adjoint matrix for a n × n matrix and for solving a system of n-1 linear homogeneous equations in n variables by Cramer's rule using O(n4) ring operations (without the division operation) over an arbitrary commutative ring. The exponent in the estimate of the computation time can be additionally reduced

T. R. Seifullin

2002-01-01

414

On the Characteristic impedance of the TEM horn antenna  

Microsoft Academic Search

Some time ago, Carrel presented an analytical formula, based on conformal mapping, for the characteristic impedance of the transverse electromagnetic horn antenna . Later, results from this formula were shown to be in error, and Lambert et al. offered a new analytical formula, also based on conformal mapping . This formula also contains an error that is easily corrected. Independently,

R. T. Lee; G. S. Smith

2004-01-01

415

Seasonal Rhinitis, Clinical Characteristics and Risk Factors for Asthma  

Microsoft Academic Search

Background: The aim was to determine the clinical characteristics of patients with seasonal rhinitis (SR) and to disclose differences in the treatment of SR between an adult allergy clinic and other clinics over time. Methods: A retrospective study was conducted based on clinical records of 774 out of 955 patients diagnosed with SR in an adult allergy clinic between 1

B. Bozkurt; G. Karakaya; A. F. Kalyoncu

2005-01-01

416

EISCAT - An updated description of technical characteristics and operational capabilities  

Microsoft Academic Search

This paper describes the European Incoherent Scatter Installations in North Scandinavia. Technical characteristics are given and the procedures designed for preparing and running experiments are outlined. Features of a set of adopted standard programmes and the method of data analysis are sketched along with the principles established for allocating observing time. The paper briefly reviews the operation of the facility

Kristen Folkestad; Tor Hagfors; Svante Westerlund

1983-01-01

417

Evaluating thermal aging characteristics of electric power transmission lines  

Microsoft Academic Search

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

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

2010-01-01

418

Rail gun performance and plasma characteristics due to wall ablation  

NASA Technical Reports Server (NTRS)

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.

Ray, P. K.

1986-01-01

419

Short-Term Temporal Stability in Observed Retail Food Characteristics  

ERIC Educational Resources Information Center

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…

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

2010-01-01

420

Roughness characteristics of natural channels  

USGS Publications Warehouse

Color photographs and descriptive data are presented for 50 stream channels for which roughness coefficients have been determined. All hydraulic computations involving flow in open channels require an evaluation of the roughness characteristics of the channel. In the absence of a satisfactory quantitative procedure this evaluation remains chiefly an art. The ability to evaluate roughness coefficients must be developed through experience. One means of gaining this experience is by examining and becoming acquainted with the appearance of some typical channels whose roughness coefficients are known. The photographs and data contained in this report represent a wide range of channel conditions. Familiarity with the appearance, geometry, and roughness characteristics of these channels will improve the engineer's ability to select roughness coefficients for other channels .

Barnes, Harry Hawthorne

1967-01-01

421

Impact characteristics of articular cartilage.  

PubMed

A rigid l m high stainless steel drop tower employing linear bearings has been used to study the impact characteristics of human articular cartilage. Instrumentation included a specially designed optoelctronic position transducer, piezoelectric force transducer, and high speed storage oscilloscope. Forty-eight 9 mm diameter samples of living articular cartilage and subchondral bone from the tibial plateaus of 4 human donors have been impacted at strains from 10 to 50%, and strain rates of 500s-1 and 1000 s-1. The integral bone/cartilage samples were mounted in polymethyl methacrylate for testing. Bone and cement impact characteristics have been studied separately. Stress, strain, and energy absorption data have been assembled for all the samples. Chondrocyte viability subsequent to impact has been investigated with the use of tritum labeled proline and autoradiography. Viability has been studied in relation to both the mechanical data and structural damage. PMID:700994

Finlay, J B; Repo, R U

1978-01-01

422

Fracture characteristics of balloon films  

NASA Technical Reports Server (NTRS)

An attempt was made to determine the failure modes of high altitude scientific balloons through an investigation of the fracture characteristics of the thin polyethylene films. Two films were the subject of the evaluation, Winzen Int.'s Stratafilm SF-85 and Raven Industries' Astro-E. Research began with an investigation of the film's cold brittleness point and it's effect on the ultimate strength and elasticity of the polyethylene film. A series of preliminary investigations were conducted to develop an understanding of the material characteristics. The primary focus of this investigation was on the notch sensitivity of the films. Simple stress strain tests were also conducted to enable analysis employing fracture toughness parameters. Studies were conducted on both film types at 23 C (room temperature), -60 C, -90 C, and -120 C.

Portanova, Marc A.

1989-01-01

423

Map characteristics of Landsat mosaics  

NASA Technical Reports Server (NTRS)

Map characteristics of the Landsat mosaics developed at JPL are considered. Procedures for digital mosaicking of Landsat frames to standard map projections were used to mosaic at full resolution ten scenes over the California desert region and twenty-one scenes over Arizona. The procedures are analyzed for horizontal positioning error (global and local) and the potential for classification error associated with the adjustment of brightness of Z values between frames; the use of this technology for the mapping of extensive features is discussed. Mosaicking facilities, techniques, mapping accuracy, and thematic mapping characteristics are described. A comparative analysis of Landsat mosaicking technology developed at Goddard Space Flight Center, IBM Gaithersburg, and USGS Flagstaff is made, and suggestions are given for algorithm development to improve systems capacity and ability to handle a variety of cases.

Zobrist, A. L.; Bryant, N. A.

1979-01-01

424

Radiative characteristics of plant leaf  

Microsoft Academic Search

Existing leaf radiation models are reviewed. A new concept of the optical model of the leaf as a multiphase system containing\\u000a three aggregate ensembles of particles significantly different in microphysical and optical characteristics is proposed. The\\u000a proposed model is based on the reconstruction of the particle size distribution function from the experimental leaf absorption\\u000a spectrum. Based on the obtained microphysical

G. M. Krekov; M. M. Krekova; A. A. Lisenko; A. Ya. Sukhanov

2009-01-01

425

Vibration characteristics of circular nanoplates  

NASA Astrophysics Data System (ADS)

This article deals with free vibration of circular nanoplates with consideration of surface properties due to high surface to volume ratio. Classical laminated plate is employed with inclusion of surface elasticity and surface residual stress effects. Solution of the resulting differential equation leads to size dependent behavior of natural frequencies and mode shapes of vibration to be demonstrated. Deviation of the results from conventional theories is shown to be due to changes in the arguments of Bessel functions in the corresponding characteristic equations.

Assadi, Abbas; Farshi, Behrooz

2010-10-01

426

Three-dimensional modeling of diesel engine intake flow, combustion and emissions-2  

NASA Technical Reports Server (NTRS)

A three-dimensional computer code, KIVA, is being modified to include state-of-the-art submodels for diesel engine flow and combustion. Improved and/or new submodels which have already been implemented and previously reported are: wall heat transfer with unsteadiness and compressibility, laminar-turbulent characteristic time combustion with unburned HC and Zeldo'vich NO(x), and spray/wall impingement with rebounding and sliding drops. Progress on the implementation of improved spray drop drag and drop breakup models, the formulation and testing of a multistep kinetics ignition model, and preliminary soot modeling results are described. In addition, the use of a block structured version of KIVA to model the intake flow process is described. A grid generation scheme was developed for modeling realistic (complex) engine geometries, and computations were made of intake flow in the ports and combustion chamber of a two-intake-value engine. The research also involves the use of the code to assess the effects of subprocesses on diesel engine performance. The accuracy of the predictions is being tested by comparisons with engine experiments. To date, comparisons were made with measured engine cylinder pressure, temperature and heat flux data, and the model results are in good agreement with the experiments. Work is in progress that will allow validation of in-cylinder flow and soot formation predictions. An engine test facility is described that is being used to provide the needed validation data. Test results were obtained showing the effect of injection rate and split injections on engine performance and emissions.

Reitz, R. D.; Rutland, C. J.

1993-01-01

427

Analyzing characteristics of hybrid rice seed  

NASA Astrophysics Data System (ADS)

Incompletely closed glumes, germ on panicle and disease are three characteristics of hybrid rice seed, which are actual reasons of poor seed quality. To find how many and which categories should be classified to meet the demand of produce actually, the effects of various degree of incompletely closed glumes, germ on panicle and disease on ratio of germination in changed storage periods were studied with standard germination rate test. An electronic scanning microscope was used for micro-observation and measurement. Then the possibility of automation inspection was tested with a machine vision system. The measures of increasing quality of hybrid rice seed were discussed in the paper at last. In the light of the periods of treatment and the classification of characteristics, difference steps should be taken. Before storage, Seeds with germ or severe disease should be rejected at first. Then seeds with incompletely closed glumes or spot disease might be stored separately for a shorter time in dried condition and treated with antisepsis before using for some special fields with lower quality demand. The seeds with fine fissure between glumes should be stored in a strictly controlled condition separately and inspected before use, just like other normal and healthy seeds.

Cheng, Fang; Ying, Yibin

2004-03-01

428

Directional Characteristics of Complex Surf Zone Waves  

NASA Astrophysics Data System (ADS)

Variation in wave direction prior to, during, and subsequent to breaking is often substantial and can result from a variety of mechanisms. In addition to well-known changes brought about by reflection and refraction, changes in directional spread may also occur near the breakpoint due to processes not directly related to bathymetric variation. To accurately quantify breaker angle characteristics across a surf zone region, data adaptive methods for resolving directional wave spectra have been applied to measurements collected during October and November 1999 at Duck NC. These measurements included time series from in-situ "PUV" instrumentation along a cross-shore transect and high-resolution digital imagery of the surf zone region recorded from both fixed and airborne cameras. The use of multiple types of measurements (e.g. pressure, velocity, intensity) with good coverage enabled the computation of directional spectra at numerous locations over an approximately 300 m x 300 m region extending from outside the breakpoint to the shoreline. Directional broadening was found to increase closer to the shoreline under moderate to high-energy wave conditions. In some cases, scattering patterns were observed with wave components propagating obliquely relative to the mean propagation direction. The most complicated wave patterns occurred just offshore of the shore-parallel sand bar that was also roughly coincident with the temporally averaged breakpoint location. The characteristics of these waves and their possible generation mechanisms are discussed.

Holland, K. T.; Kaihatu, J. M.; Dugan, J. P.; Williams, J. Z.

2001-12-01

429

Arbitrarily high order nodal and characteristic methods  

SciTech Connect

The quest for higher computational efficiency initially led researchers in the neutron transport area to develop and implement high-order approximations for solving the linear Boltzmann equational. This drive aimed at achieving higher accuracy on coarse meshes, thereby resulting in a net savings of computational resources represented by execution time and memory. Many endeavors succeeded in reaching this goal, producing a variety of elegent, albeit complicated, formalisms, that proved extremely accurate and efficient in solving test, as well as practical applications, problems. The two main classes of high order transport methods that recieved the most attention are the Nodal and Characteristic methods. A de facto linear order standard for the spatial approximation (even though Quadratic Nodal Methods were also considered) was dictated by the algebraic complexity of the derivation of the discrete variable equations, the programming complexity of implementing and verifying them in codes, and limitations on computational resources available to run such codes. The significant advances in computational resources in terms of hardware capacity and speed, as well as architectural innovations such as vector and parallel processing, all but eliminated the third (above) obstacle towards the development and implementation of even higher order methods. The algebraic and programming complexities, on the other hand, were alleviated to some extent by the development of Arbitrarily High Order Transport methods of the Nodal and the Characteristic types, which are discussed in this report.

Azmy, Y.Y.

1994-09-01

430

Overcurrent time delay determination using gain scheduled PID controllers  

Microsoft Academic Search

The inverse time overcurrent relay operation is based upon the current setpoint and also the time multiplier setting. Depending on the ratio of the value of the current and the setpoint current together with the value of the time multiplier setting, the amount of time delay for the trip command is determined using the inverse time characteristics. This would mean

A. A. Zainul; A. Ramasamy; I. Z. Abidin; F. H. Nagi

2009-01-01

431

[Infrared spectrum characteristics of vehicle body paint].  

PubMed

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

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

2012-07-01

432

Aerodynamic characteristics of the Fiat UNO car  

SciTech Connect

The purpose of this article is to describe the work conducted in the aerodynamic field throughout the 4-year development and engineering time span required by the project of the UNO car. A description is given of all the parametric studies carried out. Through these studies two types of cars at present in production were defined and the characteristics of a possible future sports version laid down. A movable device, to be fitted in the back window, was also set up and patented. When actuated it reduces soiling of back window. A description is also provided of the measurements made in the car flow field and some considerations are outlined about the method applied. This method is still in development phase but it already permits some considerations and in-depth investigations to be made on the vehicle wake.

Costelli, A.F.

1984-01-01

433

Maternal Characteristics Predicting Young Girls’ Disruptive Behavior  

PubMed Central

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

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

2011-01-01

434

Maternal characteristics predicting young girls' disruptive behavior.  

PubMed

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 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

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

2011-01-01

435

Microbiological characteristics of Pacific shrimp (Pandalus jordani).  

PubMed Central

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

Lee, J S; Pfeifer, D K

1977-01-01

436

Polarization characteristics of the Jensch coelostat.  

NASA Astrophysics Data System (ADS)

The polarization characteristics of Jensch coelostats are investigated with the coelostat of the Sayan Observatory service-forecast solar telescope (STOP) as an example. The theory of coelostats of this design is examined briefly, and the basic relationships needed for practical calculation of Stokes-parameter transformations on reflection of light from the mirrors a functions of the Sun's declination and hour angle are presented. Note is taken of the highly important dependence of the instrumental polarization (IP) on the coordinates of the Sun and on the latitude of the coelostat station. At the same time, the IP depends quite weakly on the errors of adjustment of the coelostat. The results of theoretical IP calculations for Jensch coelostats are illustrated with actual observations made at the STOP.

Demidov, M. L.

437

Study on fluorescence characteristics of duloxetine hydrochloride  

NASA Astrophysics Data System (ADS)

The fluorescence characteristics of duloxetine hydrochloride are studied in this paper. The fluorescence emission spectra of duloxetine demonstrate that intramolecular charge-transfer takes place between thiophene ring and napthalenyloxy group upon irradiation. The effects of excitation light, solvent system, variation of solution pH value, metal ions and vitamin C on the fluorescence spectra of duloxetine hydrochloride are elucidated, respectively. A spectrofluorometric method of quantitative determination of duloxetine in dosage form is reported for the first time, the linear range is 7.14 × 10 -8 mol/L to 1.43 × 10 -5 mol/L, the linear correlation coefficient r is equal to 0.9997, and the detection limit is 3.5 × 10 -8 mol/L. The accuracy and the precision are satisfactory.

Liu, Xiangping; Du, Yingxiang; Wu, Xiulan

2008-12-01

438

Behavioral characteristics of effective crew leaders  

NASA Technical Reports Server (NTRS)

The behaviors of effective versus less effective captains as they form and lead their crews in line operations are analyzed. The research examines real work groups in an actual organization with a specific and consequential task to perform and is based on a normative model of work group effectiveness. Selection of captains is outlined, as well as data collection over the course of six months of crew and cockpit observations including over 300 hours of direct crew observations and 110 hours of actual flight time. Common characteristics of the effective leaders as well as the deviations of the less effective are described, and organizational implications are assessed. The concept of 'shells' depicted as a series of concentric circles moving outward from the group's task execution at the center is introduced and discussed.

Ginnett, Robert C.

1989-01-01

439

Control of time delay processes with uncertain delays: Time delay stability margins  

Microsoft Academic Search

In this paper, the stability of time delay processes that have uncertain delays is considered, and the maximum allowable perturbation which may occur in the time delays so as to maintain stability are determined. In particular, the characteristic equations of time delay systems are quasipolynomials, whose roots determine the stability of such systems, and the root-locus of these equations in

Mohammad Bozorg; Edward J. Davison

2006-01-01

440

Assessment of a parabolic analysis for axisymmetric internal flows in rocket and turbomachinery ducts  

NASA Astrophysics Data System (ADS)

The flow paths in gas turbine passages encompass a wide range of flow properties such as Reynolds number and Mach number as well as many other variable flow conditions such as swirl, free-stream turbulence, and laminar/turbulent transition. An existing computer program, the Axisymmetric Diffuser Duct (ADD) code, which calculates compressible, turbulent, swirling flow through axisymmetric ducts has been modified to include the effects of free-stream turbulence and laminar/turbulent transition. The program has been evaluated on a matrix of test cases to determine its accuracy, robustness, and limits of applicability. This improved version of the ADD code calculates solutions which compare well with available data and can now be applied to a wider range of problems than previously possible. In addition a concept called local enhancement was developed and tested on a simple two-dimensional geometry in order to demonstrate a method to reduce computer time. In this concept the pressure distribution is calculated on a coarse grid using the ADD code and the viscous layer is locally enhanced using a boundary layer analysis. By applying this concept, an order of magnitude reduction in computer time was possible without any loss in accuracy.

Power, G. D.; Anderson, O. L.

1986-06-01

441

Characteristics of Extreme Auroral Charging Events  

NASA Technical Reports Server (NTRS)

The highest level spacecraft charging observed in low Earth orbit (LEO) occurs when spacecraft are exposed to energetic auroral electrons. Since auroral charging has been identified as a mechanism responsible for on-orbit anomalies and even possible satellite failures it is important to consider extreme auroral charging events as design and test environments for spacecraft to be used in high inclination LEO orbits. This paper will report on studies of extreme auroral charging events using data from the SSJ/4 and SSJ/5 precipitating electron and ion sensors on the Defense Meteorology Satellite Program (DMSP) satellites. Early studies of DMSP charging to negative potentials =100 V focused on statistics of the electron environment responsible for charging. Later statistical studies of auroral charging have generally focused on solar cycle dependence of charging behavior and magnitude of the maximum potential and duration of the charging events. We extend these studies to focus on more detailed investigations of extreme charging event characteristics that are required to evaluate potential threats to spacecraft systems. A collection of example auroral charging events is assembled from the DMSP data set using the criteria that "extreme auroral charging" is defined as periods with spacecraft negative potentials =400 V. Specific characteristics to be treated include (but are not limited to) maximum and mean potentials, time history of spacecraft potentials through the events, total charging duration and the time potentials exceed voltage thresholds, frame charging/discharging rates, and information on geographic and geomagnetic latitudes at which the events are observed. Finally, we will comment on the implications of these studies for potential auroral charging risks to the International Space Station.

Minow, Joseph I.; Willis, Emily M.; Parker, Linda Neergard

2014-01-01

442

Discrete-time demodulation of continuous-time signals.  

NASA Technical Reports Server (NTRS)

Nonlinear stochastic estimation theory is applied to the problem of obtaining discrete-time demodulator structures for the common types of analog communication signals. A stochastic communication model is presented that can be treated with current results in estimation theory. Approximate algorithms are developed for the estimation problem that yield mathematically realizable receiver structures for the cases of AM, PC, and FM. The digital receivers yield performance characteristics that compare favorably with those of their analog counterparts.

Kelly, C. N.; Gupta, S. C.

1972-01-01

443

Unbinding Time: Alternate Work Schedules and Work-Life Balance  

Microsoft Academic Search

We examine the possibility that alternate work schedules affect perceived work-life imbalance—the “time bind.” The results show that alternate schedules per se do not “unbind” time. However, perceived control of work schedules increases work-life balance net of family and work characteristics. The most consistent family characteristic predicting imbalance is being a parent. The most consistent work characteristic predicting imbalance is

Mark Tausig; Rudy Fenwick

2001-01-01

444

Measuring the real-time operating system performance  

Microsoft Academic Search

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

Krzysztof M. Sacha

1995-01-01

445

Characteristics of individuals with integrated pensions.  

PubMed

Employer pensions that integrate benefits with Social Security have been the focus of relatively little research. Since changes in Social Security benefit levels and other program characteristics can affect the benefit levels and other features of integrated pension plans, it is important to know who is covered by these plans. This article examines the characteristics of workers covered by integrated pension plans, compared to those with nonintegrated plans and those with no pension coverage. Integrated pension plans are those that explicitly adjust their benefit structure to help compensate for the employer's contributions to the Social Security program. There are two basic integration methods used by defined benefit (DB) plans. The offset method causes a reduction in employer pension benefits by up to half of the Social Security retirement benefit; the excess rate method is characterized by an accrual rate that is lower for earnings below the Social Security taxable maximum than above it. Defined contribution (DC) pension plans can be integrated along the lines of the excess rate method. To date, research on integrated pensions has focused on plan characteristics, as reported to the Bureau of Labor Statistics (BLS) through its Employee Benefits Survey (EBS). This research has examined the prevalence of integration among full-time, private sector workers by industry, firm size, and broad occupational categories. However, because the EBS provides virtually no data on worker characteristics, analyses of the effects of pension integration on retirement benefits have used hypothetical workers, varying according to assumed levels of earnings and job tenure. This kind of analysis is not particularly helpful in examining the potential effects of changes in the Social Security program on workers' pension benefits. However, data on pension integration at the individual level are available, most recently from the Health and Retirement Study (HRS), a nationally representative survey of individuals aged 51-61 in 1992. This dataset provides the basis for the analysis presented here. The following are some of the major findings from this analysis. The incidence of pension integration in the HRS sample is 32 percent of all workers with a pension (14 percent of all workers). The HRS can also identify integrated DC plans, a statistic that is not available from BLS data. The rate of integration for workers with only DC plans is 8 percent. After controlling for other variables, several socio-demographic characteristics are significantly related to the incidence of integration. The probability of having an integrated pension is 4.6 percentage points less for men compared to women. Non-Hispanic blacks are 6.4 percentage points less likely than non-Hispanic whites to have integrated pensions. Union members are 14 percentage points less likely to have integrated pensions, while workers with less than a graduate level education are at least 15 percentage points more likely to have a pension that is integrated. Some earnings and pension characteristics are also significantly correlated with pension integration. Earnings are positively related, with the probability of having an integrated pension increasing by 2 percentage points for an increase of $1,000 in annual pay. An even larger effect comes from earning at or above the Social Security taxable maximum. Workers at or above this income level are 10 percentage points more likely to have an integrated plan, but for those with more than one plan the probability of pension integration goes up by 13 percentage points. PMID:10732369

Bender, K A

1999-01-01

446

Tools for real time system design  

Microsoft Academic Search

This paper describes the development of a toolset that supports the specification and design of large real time systems. The starting point is the evolution of a method suitable for use in practical environments; for example in the specification of telecommunication systems. The characteristics that are required of a good specification method for real time systems are discussed and a

R. A. Orr; M. T. Norris; R. Tinker; C. D. V. Rouch

1988-01-01

447

Time Travellers: Adventure to the Archaean  

NSDL National Science Digital Library

In this activity, students play the roles of time travelers and travel to the Archaean era to learn what early Earth was like during that time. They collect information on the Archaean atmosphere, life forms, and landscape, and write a report that summarizes its characteristics. A scoring rubric for the report is provided.

Weaver, Marion

448

Fractal analysis of time varying data  

DOEpatents

Characteristics of time varying data, such as an electrical signal, are analyzed by converting the data from a temporal domain into a spatial domain pattern. Fractal analysis is performed on the spatial domain pattern, thereby producing a fractal dimension D.sub.F. The fractal dimension indicates the regularity of the time varying data.

Vo-Dinh, Tuan (Knoxville, TN); Sadana, Ajit (Oxford, MS)

2002-01-01

449

Spectral Characteristics of Titan's Surface  

NASA Astrophysics Data System (ADS)

Cassini/Huygens and ground-based measurements of Titan reveal an eroded surface, with lakes, dunes, and sinuous washes. These features, coupled with measurements of clouds and rain, indicate the transfer of methane between Titan’s surface and atmosphere. The presence of methane-damp lowlands suggests further that the atmospheric methane (which is continually depleted through photolysis) may be supplied by sub-surface reservoirs. The byproducts of methane photolysis condense onto the surface, leaving layers of organic sediments that record Titan’s past atmospheres.Thus knowledge of the source and history of Titan's atmosphere requires measurements of the large scale compositional makeup of Titan's surface, which is shrouded by a thick and hazy atmosphere. Towards this goal, we analyzed roughly 100,000 spectra recorded by Cassini’s Visual and Infrared Mapping Spectrometer (VIMS). Our study is confined to the latitude region (20S—20N) surrounding the landing site of the Huygens probe (at 10S, 192W), which supplied only measurement of the vertical profiles of the methane abundance and haze scattering characteristics. VIMS near-IR spectral images indicate subtle latitudinal and temporal variations in the haze characteristics in the tropics. We constrain these small changes with full radiative transfer analyses of each of the thousands of VIMS spectra, which were recorded of different terrains and at different lighting conditions. The resulting models of Titan’s atmosphere as a function of latitude and year indicate the seasonal migration of Titan’s tropical haze and enable the derivation of Titan’s surface albedo at 8 near-IR wavelength regions where Titan’s atmosphere is transparent enough to allow visibility to the surface. The resultant maps of Titan’s surface indicate a number of terrain types with distinct spectral characteristics that are suggestive of atmospheric and surficial processes, including the deposition of organic material, erosion of sediments and potential sources of methane.

Griffith, Caitlin A.; Turner, Jake D.; Penteado, Paulo; Khamsi, Tymon B.; Soderblom, Jason M.

2014-11-01

450

Characteristics of early, long recovery VLF scattering events  

NASA Astrophysics Data System (ADS)

Experimental observations of early, long recovery VLF events (LOREs) and their causative radio atmospherics (sferics) are analyzed -- 49 events are presented, including over-sea and over-land events. We demonstrate that the phasor addition of ambient and scattered VLF fields may lead to amplitude and phase changes that have different perturbation characteristics (onset duration, recovery time, etc.), and conclude that VLF perturbations are best categorized by their associated normalized scattered field phasor. Additionally, we present observations which demonstrate that normalized scattered field characteristics can depend upon the receiving antenna orientation.

Kotovsky, D. A.; Moore, R. C.

2013-12-01

451

Performance characteristics of an S-600 portable atomic absorption spectrophotometer  

SciTech Connect

Performance characteristics of an S-600 portable atomic absorption spectrophotometer are discussed. The optimum analysis conditions, characteristic mass, and detection limit for determining Be, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in solutions and in powders are specified. Direct analysis of solid-state samples (standard soil samples) is described. The relative error of measurement by the calibration graph method lies, with few exceptions, within 7-30%, and by the addition method, within 4-20%. The time needed for a single element determination is 10-20 min.

Pelieva, L.A.; Dyndar, Zh.I. [Elektron Co., Sumy (Russian Federation)

1995-12-01

452

Hydrologic Characteristics of Alder Creek, Iron County, Wisconsin  

USGS Publications Warehouse

The purpose of this study was to determine the hydrologic characteristics of Alder Creek, Iron County, Wisconsin, which are needed by water-resource planners to evaluate a reservoir site proposed by the Whitecap Mountain Corporation on Alder Creek. The hydrologic characteristics estimated were the mean flows, low flows, flood peaks, suspended-sediment discharge, and depth to bedrock. Also included is an estimate of the time required to fill the proposed reservoir. The study was done in cooperation with the Wisconsin Department of Natural Resources.

Holmstrom, B.K.; Gebert, W.A.; Borman, R.G.

1973-01-01

453

Pheochromocytoma and paraganglioma: imaging characteristics.  

PubMed

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

Baez, Juan C; Jagannathan, Jyothi P; Krajewski, Katherine; O'Regan, Kevin; Zukotynski, Katherine; Kulke, Matthew; Ramaiya, Nikhil H

2012-01-01

454

Fairytale Characteristics in Medieval Romances  

E-print Network

of California Press, 1977), pp.7-10. See also Linda Dégh, „Folk Narrative?, in Folklore and Folklife: An Introduction, ed. by Richard M. Dorson (London: University of Chicago Press, 1972), pp.53-83 (pp.58-80). 3 Sir Isumbras is one example: see... , their structure, style, and so on. The field of exploration most relevant to this study in this respect, though it is not the only one, is Folklore Studies. 9 The first significant explication of the characteristics of folktale in general was Axel Olrik...

Burton, Julie

2010-01-01

455

Saturation characteristics of fast photodetectors  

Microsoft Academic Search

Saturation of photodetectors is measured in the time domain using optical pulses of different duration and in the frequency domain using amplitude-modulated optical carriers. In the time domain, saturation is characterized by a reduction in peak photocurrent and growth of a pulse tail indicating that significant carrier velocity reduction is occurring as the opposing space-charge field persists. In the frequency

Pao-Lo Liu; Keith J. Williams; Michael Y. Frankel; Ronald D. Esman

1999-01-01

456

Adaptive guidance law design based on characteristic model for reentry vehicles  

Microsoft Academic Search

In this paper an adaptive guidance law based on the characteristic model is designed to track a reference drag acceleration\\u000a for reentry vehicles like the Shuttle. The characteristic modeling method of linear constant systems is extended for single-input\\u000a and single-output (SISO) linear time-varying systems so that the characteristic model can be established for reentry vehicles.\\u000a A new nonlinear differential golden-section

Junchun Yang; Jun Hu; Maolin Ni

2008-01-01

457

Clinical characteristics of alternaria keratitis.  

PubMed

Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

Hsiao, Ching-Hsi; Yeh, Lung-Kun; Chen, Hung-Chi; Lin, Hsin-Chiung; Chen, Phil Y F; Ma, David H K; Tan, Hsin-Yuan

2014-01-01

458

Clinical Characteristics of Alternaria Keratitis  

PubMed Central

Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

Lin, Hsin-Chiung; Chen, Phil Y. F.; Ma, David H. K.; Tan, Hsin-Yuan

2014-01-01

459

Novel features of a fully developed mixing-layer between co-flowing laminar and turbulent Couette flows  

NASA Astrophysics Data System (ADS)

A new flow configuration has been proposed in which a bilateral mixing-layer exists in the junction between co-flowing laminar and turbulent plane Couette flows. Contrary to a classical plane mixing-layer, the present mixing-layer did neither grow in time nor in streamwise direction. However, the mixing zone varied with the distance from the stationary wall. A direct numerical simulation showed that very-large-scale flow structures were found in the turbulent part of the flow with Reynolds number 1300 based on half the velocity U1 of the fastest-moving wall and half of the distance 2h between the walls. The laminar-turbulent interface exhibited a large-scale meandering motion with frequency 0.014U1/h and wavelength about 25h. Large-scale Taylor-Görtler-like roll cells were observed in the nominally laminar flow region with Reynolds number 260. This tailor-made flow is particularly well suited for explorations of momentum transfer and intermittency in the vicinity of the laminar-turbulent interface.

Narasimhamurthy, Vagesh D.; Andersson, Helge I.; Pettersen, Bjørnar

2014-03-01

460

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

NASA Astrophysics Data System (ADS)

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.

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