WorldWideScience

Sample records for longitudinal stability characteristics

  1. Longitudinal stability of asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study

    OpenAIRE

    Silkoff, P E; Laviolette, M.; Singh, D.; FitzGerald, J M; Kelsen, S.; Backer, V.; Porsbjerg, C; Girodet, P. O.; Berger, P; Kline, J. N.; Khatri, S.; Chanez, P.; Susulic, V S; Barnathan, E. S.; Baribaud, F.

    2016-01-01

    BACKGROUND: Asthma is a biologically heterogeneous disease and development of novel therapeutics requires understanding of pathophysiologic phenotypes. There is uncertainty regarding the stability of clinical characteristics and biomarkers in asthma over time. This report presents the longitudinal stability over 12 months of clinical characteristics and clinically accessible biomarkers from ADEPT.METHODS: Mild, moderate, and severe asthma subjects were assessed at 5 visits over 12 months. Ass...

  2. An experimental study of the longitudinal aerodynamic and static stability characteristics of hang gliders

    OpenAIRE

    Kilkenny, E. A.

    1986-01-01

    A mobile experimental test facility has been developed to carry out the aerodynamic evaluation of hang glider wings normally performed in a wind tunnel. Longitudinal aerodynamic data obtained using this facility is presented for three modern hang glider wings, a Silhouette, Demon 175 and Magic 166, together with surface flow patterns for the latter two wings. The longitudinal stability criterion are studied and alternatives established, equivalent to the stick fixed an...

  3. Effects of a sweptback hydrofoil on the force and longitudinal stability characteristics of a typical high-speed airplane

    Science.gov (United States)

    Wood, Raymond B

    1948-01-01

    An investigation was conducted in the Langley 8-foot high-speed tunnel to determine the effects of a sweptback hydrofoil on the force and longitudinal stability characteristics of a typical high-speed airplane. The Mach number range for this investigation was from 0.60 to 0.95 and at M = 1.20. The effects of the hydrofoil on the lift, drag, and pitching-moment characteristics are presented.

  4. Stability characteristics of ring-stiffened cylindrical shells under different longitudinal and transverse external pressures

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Tian; YAO Wen; LIANG Chao; JI Nan

    2007-01-01

    Because ring-stiffened cylindrical shell structures have many merits, they are widely used in many areas. However, as the strength of steel increase continuously, ensuring of the structure stability is becoming more and more important. Therefore, it is necessary to carry on a more particular analysis. Based on the understanding and analysis of the characteristics of stability for a ring-stiffened cylindrical shell under uniform external pressure and under external single pressure, the characteristics under different cross uniform external pressures are analyzed, and the regularity of it is also gotten. The curve of stability given various geometrical parameters under different cross uniform external pressures is protracted by the analysis of the theory. The conclusion not only improves the theory structural mechanics, it also was important effects on engineering calculation and design.

  5. Guidelines for Computing Longitudinal Dynamic Stability Characteristics of a Subsonic Transport

    Science.gov (United States)

    Thompson, Joseph R.; Frank, Neal T.; Murphy, Patrick C.

    2010-01-01

    A systematic study is presented to guide the selection of a numerical solution strategy for URANS computation of a subsonic transport configuration undergoing simulated forced oscillation about its pitch axis. Forced oscillation is central to the prevalent wind tunnel methodology for quantifying aircraft dynamic stability derivatives from force and moment coefficients, which is the ultimate goal for the computational simulations. Extensive computations are performed that lead in key insights of the critical numerical parameters affecting solution convergence. A preliminary linear harmonic analysis is included to demonstrate the potential of extracting dynamic stability derivatives from computational solutions.

  6. Wind-tunnel tests of a 1/4 scale model of the Bell XS-1 transonic airplane. 1: Longitudinal stability and control characteristics

    Science.gov (United States)

    Donlan, C. J.; Kemp, W. B., Jr.; Polhamus, E. C.

    1976-01-01

    A 1/4 scale model of the Bell XS-1 transonic aircraft was tested in the Langley 300 mile-per-hour 7 by 10 foot tunnel to determine its low speed longitudinal stability and control characteristics. Pertinent longitudinal flying qualities expected of the XS-1 research airplane were estimated from the results of these tests including the effects of compressibility likely to be encountered at speeds below the force break. It appears that the static longitudinal stability and elevator control power will be adequate, but that the elevator control force gradient in steady flight will be undesirably low for all configurations. It is suggested that a centering spring be incorporated in the elevator control system of the airplane in order to increase the control force gradient in steady flight and in maneuvers.

  7. Low-speed wind-tunnel investigation of the longitudinal stability characteristics of a model equipped with a variable-speed wing, 23 May 1949

    Science.gov (United States)

    Donlan, C. J.; Sleeman, W. C., Jr.

    1976-01-01

    The longitudinal stability characteristics of a complete model equipped with a variable sweep wings at angles of sweepback of 45 deg, 30 deg, 15 deg, and 0 deg investigated. Various wing modifications and an extern 1 flap arrangement designed to minimize the shift in neutral point accompanying the change in sweep angle were studied. The results indicate that stability at the stall was obtained at a sweep angle of 15 deg without recourse to stall control devices. The basic neutral point movement accompanying the change in sweep angle from 45 deg to 15 deg amounted to 56 percent of the mean aerodynamic chord (at zero sweep angle) and the most effective modification investigated only reduced this change to 47 percent of the chord. It appears, therefore, that for designs in which the fuselage is the major load carrying element some relative movement between the wing and center of gravity will be required to assure satisfactory stability at all sweep angles.

  8. Static Longitudinal Stability and Control Characteristics At A Mach Number of 1.99 of a Lenticular-Shaped Reentry Vehicle

    Science.gov (United States)

    Jackson, Charles M., Jr.; Harris, Roy V., Jr.

    1960-01-01

    An investigation has been made in the Langley 4- by 4-foot supersonic pressure tunnel at a Mach number of 1.99 to determine the longitudinal stability and control characteristics of a reentry model consisting of a lenticular-shaped body with two fin configurations (horizontal fins with end plates). Effects of deflecting the larger size fins as pitch-control surfaces were also investigated. The results indicate that the body alone was unstable from an angle of attack of 0 deg to about 55 deg where it became stable and remained so to 90 deg. The addition of fins provided positive longitudinal stability throughout the angle-of-attack range and increased the lift-drag ratio of the configuration. Reducing the horizontal-fin area at the inboard trailing edge of the fin had only a small effect on the aerodynamic characteristics of the vehicle for the condition of no fin deflection. Deflecting the fins, appeared to be an effective means of pitch control and had only a small effect on lift-drag ratio.

  9. Low-Subsonic-Speed Static Longitudinal Stability and Control Characteristics of a Winged Reentry-Vehicle Configuration Having Wingtip Panels that Fold up for High-Drag Reentry

    Science.gov (United States)

    Ware, George M.

    1960-01-01

    An investigation of the low-subsonic-speed static longitudinal stability and control characteristics of a model of a manned reentry-vehicle configuration capable of high-drag reentry and glide landing has been a made in the Langley free-flight tunnel. The model had a modified 63 deg delta plan-form wing with a fuselage on the upper surface. This configuration had wingtip panels designed to fold up 90 deg for the high-drag reentry phase of the flight and to extend horizontally for the glide landing. Data for the basic configurations and modifications to determine the effects of plan form, wingtip panel incidence, dihedral, and vertical position of the wingtip panels are presented without analysis.

  10. Longitudinal and lateral static stability and control characteristics of a 1/6-scale model of a remotely piloted research vehicle with a supercritical wing

    Science.gov (United States)

    Byrdsong, T. A.; Hallissy, J. B.

    1979-01-01

    An investigation was conducted in the Langley 8-foot transonic pressure tunnel to determine the longitudinal and lateral-directional static stability and control characteristics of a 1/6-scale force model of a remotely piloted research vehicle. The model was equipped with a supercritical wing and employed elevons for pitch and roll control. Test conditions were as follows: Reynolds number of about 6.6 x 10 to the 6th power per meter, variations of sideslip from -6 deg to 6 deg, elevon deflection angle (symmetrically and asymmetrically) from -9 deg to 3 deg, and rudder deflection angle from 0 deg to -10 deg. The model was longitudinally statically stable at angles of attack up to about 7 deg, which is significantly greater than the angle of attack for the cruise condition (approximately 4 deg). In the range of test Mach numbers, the model was directionally stable and had positive effective dihedral, sufficient pitch control, and positive effectiveness of roll and yaw control.

  11. The longitudinal static stability of tailless aircraft

    OpenAIRE

    de Castro, Helena V.

    2001-01-01

    This paper describes the development of a simple theory of the longitudinal controls fixed static stability of tailless aeroplanes. The classical theory, as developed for the conventional aircraft, is modified to accommodate the particular features of the tailless aeroplanes. The theory was then applied to a particular blended-wing-body tailless civil transport aircraft, BWB-98. Cranfield University

  12. Wind-tunnel investigation of longitudinal and lateral-directional stability and control characteristics of a 0.237-scale model of a remotely piloted research vehicle with a thick, high-aspect-ratio supercritical wing

    Science.gov (United States)

    Byrdsong, T. A.; Brooks, C. W., Jr.

    1980-01-01

    A 0.237-scale model of a remotely piloted research vehicle equipped with a thick, high-aspect-ratio supercritical wing was tested in the Langley 8-foot transonic tunnel to provide experimental data for a prediction of the static stability and control characteristics of the research vehicle as well as to provide an estimate of vehicle flight characteristics for a computer simulation program used in the planning and execution of specific flight-research mission. Data were obtained at a Reynolds number of 16.5 x 10 to the 6th power per meter for Mach numbers up to 0.92. The results indicate regions of longitudinal instability; however, an adequate margin of longitudinal stability exists at a selected cruise condition. Satisfactory effectiveness of pitch, roll, and yaw control was also demonstrated.

  13. LHC Longitudinal Single-Bunch Stability Threshold

    CERN Document Server

    Esteban Muller, Juan Federico; Baudrenghien, Philippe; Lasheen, Alexandre; Roggen, Toon; Shaposhnikova, Elena; Timko, Helga; CERN. Geneva. ATS Department

    2016-01-01

    The aim of the MD studies presented here was to determine with a reasonable accuracy the single-bunch longitudinal stability threshold in the LHC. The measurements were performed by placing along the ring 8 or 20 ‘single’ bunches with different intensities but similar longitudinal emittances. Then they were accelerated and bunch stability was observed at arrival to flat top. Combining the results of two measurement sessions, the single bunch stability threshold is estimated to be (2.4 ± 0.2) × 10^11 ppb for an emittance of 1.89 eVs (1.0 ns) at 6.5 TeV with 12 MV RF voltage. Measurements were taken during the MD session MD472 from 22:00 on 20th to 05:00 on 21st July 2015 and session MD365 from 17:00 on 26th to 01:00 on 27th August 2015.

  14. Longitudinal stability in multiharmonic standing wave linacs

    Science.gov (United States)

    Carver, L. R.; Jones, R. M.; Jiang, Y.; Hirshfield, J. L.

    2016-09-01

    Accelerating cavities that excite multiple modes at integer harmonics of the fundamental frequency have the potential to be used to suppress the onset of rf breakdown and reduce the pulsed surface heating at high accelerating gradients. Understanding the effect of an additional harmonic cavity mode on the longitudinal beam dynamics is important to their development and use. A Hamiltonian that describes the longitudinal motion of a particle as it traverses a chain of multiharmonic cavities has been derived and is applied to the case of a second harmonic cavity. The Hamiltonian is based upon formalisms found in literature for the fundamental harmonic and is extended to include different longitudinal field distributions and harmonic frequencies. The study initially explores the longitudinal motion for moderate accelerating gradients with high-β protons, as this will allow fundamental properties of the stable region (acceptance and shape of the rf bucket) to be determined. High accelerating gradients are also investigated but the focus will be on phase stability throughout. This work concludes by considering the longitudinal dynamics of a modified European Spallation Source accelerator, comprised of multiharmonic cavities that has specifications broadly consistent with the accelerator.

  15. Longitudinal dynamic stability of a shuttle vehicle.

    Science.gov (United States)

    Vinh, N. X.; Laitone, E. V.

    1972-01-01

    Analytical study of the longitudinal dynamic stability of a nonrolling, lifting vehicle gliding at hypersonic speeds. The analysis applies to shuttle vehicles designed for operating up to the rim of a planetary atmosphere. A general nondimensional time transformation is introduced to derive a unified second-order linear differential equation for the angle of attack, valid for all types of reentry of a general type of vehicle. The stability of motion is discussed for two fundamental regimes of flight that are based on widely different assumptions. For near ballistic entry along a straight line trajectory, the equation reduces to a confluent hypergeometric equation, the solution of which can be expressed in terms of Whittaker's function. Using a theorem in the theory of stability of differential equations, criteria for damped oscillations are derived. It is shown that the aerodynamic criteria for stability are the same as for the case of ballistic entry. In addition, for each vehicle configuration, and specified planetary atmosphere, there exists an altitude range where the angle of attack frequency is nearly equal to the orbital frequency causing instability in pitch. This resonance instability is due to the ellipticity of the orbit. Criteria for eccentricity instability are derived.

  16. State Dependence and Trait Stability of Perfectionism: A Short-Term Longitudinal Study

    Science.gov (United States)

    Rice, Kenneth G.; Aldea, Mirela A.

    2006-01-01

    The authors examined state dependency on depression, trait stability, and state-trait characteristics of perfectionism in a short-term longitudinal study of university students. Relative stability of perfectionism was assessed with test-retest correlations across 3 time points, and results showed higher rank order and relative stability for…

  17. Effects of relaxed static longitudinal stability on a single-stage-to-orbit vehicle design

    Science.gov (United States)

    Freeman, D. C., Jr.; Wilhite, A. W.

    1979-01-01

    The effects of relaxing longitudinal stability requirements on single stage to orbit space vehicles is studied. A comparison of the mass and performance characteristics of two vehicles, one designed for positive levels of longitudinal stability and the other designed with relaxed stability requirements in a computer aided design process is presented. Both vehicles, required to meet the same mission characteristics are described. Wind tunnel tests, conducted over a Mach number range from 0.3 to 4.63 to verify estimated aerodynamic characteristics, are discussed.

  18. Longitudinal static stability requirements for wing in ground effect vehicle

    Science.gov (United States)

    Yang, Wei; Yang, Zhigang; Collu, Maurizio

    2015-06-01

    The issue of the longitudinal stability of a WIG vehicle has been a very critical design factor since the first experimental WIG vehicle has been built. A series of studies had been performed and focused on the longitudinal stability analysis. However, most studies focused on the longitudinal stability of WIG vehicle in cruise phase, and less is available on the longitudinal static stability requirement of WIG vehicle when hydrodynamics are considered: WIG vehicle usually take off from water. The present work focuses on stability requirement for longitudinal motion from taking off to landing. The model of dynamics for a WIG vehicle was developed taking into account the aerodynamic, hydrostatic and hydrodynamic forces, and then was analyzed. Following with the longitudinal static stability analysis, effect of hydrofoil was discussed. Locations of CG, aerodynamic center in pitch, aerodynamic center in height and hydrodynamic center in heave were illustrated for a stabilized WIG vehicle. The present work will further improve the longitudinal static stability theory for WIG vehicle.

  19. Longitudinal static stability requirements for wing in ground effect vehicle

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2015-03-01

    Full Text Available The issue of the longitudinal stability of a WIG vehicle has been a very critical design factor since the first experimental WIG vehicle has been built. A series of studies had been performed and focused on the longitudinal stability analysis. However, most studies focused on the longitudinal stability of WIG vehicle in cruise phase, and less is available on the longitudinal static stability requirement of WIG vehicle when hydrodynamics are considered: WIG vehicle usually take off from water. The present work focuses on stability requirement for longitudinal motion from taking off to landing. The model of dynamics for a WIG vehicle was developed taking into account the aerodynamic, hydrostatic and hydrodynamic forces, and then was analyzed. Following with the longitudinal static stability analysis, effect of hydrofoil was discussed. Locations of CG, aerodynamic center in pitch, aerodynamic center in height and hydrodynamic center in heave were illustrated for a stabilized WIG vehicle. The present work will further improve the longitudinal static stability theory for WIG vehicle.

  20. Longitudinal static stability requirements for wing in ground effect vehicle

    Directory of Open Access Journals (Sweden)

    Yang Wei

    2015-06-01

    Full Text Available The issue of the longitudinal stability of a WIG vehicle has been a very critical design factor since the first experimental WIG vehicle has been built. A series of studies had been performed and focused on the longitudinal stability analysis. However, most studies focused on the longitudinal stability of WIG vehicle in cruise phase, and less is available on the longitudinal static stability requirement of WIG vehicle when hydrodynamics are considered: WIG vehicle usually take off from water. The present work focuses on stability requirement for longitudinal motion from taking off to landing. The model of dynamics for a WIG vehicle was developed taking into account the aerodynamic, hydrostatic and hydrodynamic forces, and then was analyzed. Following with the longitudinal static stability analysis, effect of hydrofoil was discussed. Locations of CG, aerodynamic center in pitch, aerodynamic center in height and hydrodynamic center in heave were illustrated for a stabilized WIG vehicle. The present work will further improve the longitudinal static stability theory for WIG vehicle.

  1. Longitudinal Stability Criteria for a Propeller-Driven Aircraft

    OpenAIRE

    Gil Iosilevskii

    2010-01-01

    The Routh criterion is used to assess longitudinal dynamic stability of a propeller-driven aircraft. Under a few plausible assumptions on possible ranges of the pertinent stability derivatives, it reduces to a pair of simple conditions imposing a traditional aft limit (the forward of the maneuver and the neutral-speed-stability points) on the center-of-gravity position and an upper limit on the longitudinal moment of inertia. It is demonstrated that most aircraft have sufficiently small inert...

  2. Studies of longitudinal single bunch stability

    CERN Document Server

    Argyropoulos, T; Bhat, C; Baudrenghien, P; Esteban Muller, J; Hofle, W; Papotti, G; Shaposhnikova, E; Tuckmantel, J; Valuch, D; Venturini Delsolaro, W; Wehrle, U

    2011-01-01

    The goal of this MD was to study a single bunch longitudinal instability observed during the acceleration ramp in the LHC in 2010 for bunches with nominal intensity and small injected longitudinal emittance. During this MD there were two fills, the first without acceleration and the second with acceleration. In the first each ring was filled with 8 high intensity bunches with small longitudinal emittance. During the second 8 high intensity bunches were injected into each ring with longitudinal emittances varying from 0.9 eVs to 0.3 eVs. Two longitudinal instability modes (dipole and quadrupole) were observed in different parts of the cycle with both beams. Measurements of phase and bunch length oscillations, as well as data extracted from bunch profile acquisitions during the cycle, are presented in this Note together with an analysis of the growth rate dependence on bunch emittances and intensity.

  3. The longitudinal controls fixed static stability of tailless aircraft

    OpenAIRE

    de Castro, Helena V.

    2000-01-01

    This paper describes the development of a simple theory of the longitudinal controls fixed static stability of tailless aeroplanes. The classical theory, as developed for the conventional aircraft, is modified to accommodate the particular features of the tailless aeroplanes. The theory was then applied to a particular blended-wing-body tailless civil transport aircraft, BWB-98. Cranfield University

  4. Longitudinal Stability in Genetic Effects on Children's Conversational Language Productivity

    Science.gov (United States)

    DeThorne, Laura Segebart; Harlaar, Nicole; Petrill, Stephen A.; Deater-Deckard, Kirby

    2012-01-01

    Purpose: The authors examined the longitudinal stability of genetic and environmental influences on children's productive language sample measures during the early school-age years. Method: Twin study methodology with structural equation modeling was used to derive univariate estimates of additive genetic (A), shared environmental (C), and…

  5. Longitudinal Stability Criteria for a Propeller-Driven Aircraft

    Directory of Open Access Journals (Sweden)

    Gil Iosilevskii

    2010-01-01

    Full Text Available The Routh criterion is used to assess longitudinal dynamic stability of a propeller-driven aircraft. Under a few plausible assumptions on possible ranges of the pertinent stability derivatives, it reduces to a pair of simple conditions imposing a traditional aft limit (the forward of the maneuver and the neutral-speed-stability points on the center-of-gravity position and an upper limit on the longitudinal moment of inertia. It is demonstrated that most aircraft have sufficiently small inertia to remain stable as long as their center-of-gravity is properly placed. At the same time, sailplane-like aircraft (as, e.g., long endurance UAVs, with an engine installed at the rear extremity of the aircraft, may have sufficiently high inertia to become unstable regardless of their center-of-gravity placement.

  6. EXPERIMENTAL INVESTIGATIONS ON LONGITUDINAL DISPERSION CHARACTERISTICS OF TIDAL RIVERS

    Institute of Scientific and Technical Information of China (English)

    Fan Jing-yu; Wang Dao-zeng; Zhong Bao-chang

    2003-01-01

    The longitudinal dispersion characteristics of tidal rivers are experimentally investigated in a water channel. The longitudinal dispersion features and influential factors on pollutant in various stages of a tidal period in natural rivers are studied, the value ranges and variation trends of the longitudinal dispersion coefficient are obtained by means of concentration measurement. The results can provide important parameters for establishing the water quality mathematical models in tidal rivers.

  7. 14 CFR 27.175 - Demonstration of static longitudinal stability.

    Science.gov (United States)

    2010-01-01

    ... speeds from 0.8 VNE − 10 kt to 0.8 VNE + 10 kt or, if VH is less than 0.8 VNE, from VH −10 kt to VH + 10... or VH, whichever is less; (4) The landing gear retracted; and (5) The rotorcraft trimmed at 0.8 VNE or VH, whichever is less. (c) V NE. Static longitudinal stability must be shown at speeds from...

  8. 14 CFR 29.175 - Demonstration of static longitudinal stability.

    Science.gov (United States)

    2010-01-01

    ... speeds from 0.8 VNE−10 kt to 0.8 VNE + 10 kt or, if VH is less than 0.8 VNE, from VH − 10 kt to VH + 10... or VH, whichever is less; (4) The landing gear retracted; and (5) The rotorcraft trimmed at 0.8 VNE or VH, whichever is less. (c) V NE. Static longitudinal stability must be shown at speeds from...

  9. Longitudinal measurement invariance, stability and change of anger and cynicism.

    Science.gov (United States)

    Hakulinen, Christian; Jokela, Markus; Keltikangas-Järvinen, Liisa; Merjonen, Päivi; Raitakari, Olli T; Hintsanen, Mirka

    2014-06-01

    Anger and hostility are key concepts in behavioral medicine, but little is known about their stability over life course. A sample of 3,074 individuals from six age groups (aged 15-30 at the baseline) were selected from a population-based study to examine longitudinal measurement invariance, stability and change in anger and cynicism from early to middle adulthood over 15 years. Cynicism, a facet of hostility, and anger were measured 4 times in 1992, 1997, 2001 and 2007. Final longitudinal measurement invariance models achieved partial strict measurement invariance, indicating good measurement consistency over time. Rank-order stability of anger and cynicism was found to be moderate. Mean levels of anger and cynicism decreased over time, but in anger the decline was faster among women. The variance of anger and cynicism also increased over time, but in cynicism the rate of change was higher among men. Altogether, anger and cynicism show measurement invariance and moderate stability from early adulthood to middle adulthood.

  10. Longitudinal stability in genetic effects on children's conversational language productivity.

    Science.gov (United States)

    DeThorne, Laura Segebart; Harlaar, Nicole; Petrill, Stephen A; Deater-Deckard, Kirby

    2012-06-01

    The authors examined the longitudinal stability of genetic and environmental influences on children's productive language sample measures during the early school-age years. Twin study methodology with structural equation modeling was used to derive univariate estimates of additive genetic (A), shared environmental (C), and nonshared environmental (E) effects on language measures at each of 2 time points, based on 487 twins at the 1st-grade time point and 387 twins at the 2nd-grade time point. To address questions of stability over time, the authors used longitudinal latent factor analysis. Stability in the Conversational Language factor was accounted for almost entirely by shared genetic effects between 1st and 2nd grade, meaning no new genetic effects were observed at the 2nd time point. In contrast, nonshared environmental effects were entirely time point specific, meaning whatever nonshared environmental influences were operating at the first time point were not influencing individual variation in the language factor at the second time point. The discussion in this article centers on possible candidates for both genetic and nonshared environmental effects as well as implications for clinical practice and future research.

  11. Entry dynamics of space shuttle orbiter with longitudinal stability and control uncertainties at supersonic and hypersonic speeds

    Science.gov (United States)

    Stone, H. W.; Powell, R. W.

    1977-01-01

    A six-degree-of-freedom simulation analysis was conducted to examine the effects of longitudinal static aerodynamic stability and control uncertainties on the performance of the space shuttle orbiter automatic (no manual inputs) entry guidance and control systems. To establish the acceptable boundaries, the static aerodynamic characteristics were varied either by applying a multiplier to the aerodynamic parameter or by adding an increment. With either of two previously identified control system modifications included, the acceptable longitudinal aerodynamic boundaries were determined.

  12. SOME ASPECTS OF THE DEFINITION OF EMPTY CARS STABILITY FROM SQUEEZING THEIR LONGITUDINAL FORCES IN THE FREIGHT TRAIN

    Directory of Open Access Journals (Sweden)

    A. O. Shvets

    2015-06-01

    Full Text Available Purpose. Despite of the implementation various programs to improve the safety of train traffic problem of reducing gatherings rolling stock off the rails is still relevant. The study aims to clarify the existing method of determining the factor of stability from the tire longitudinal forces to ensure the sustainability of cars with increasing speeds of the rolling stock. Methodology. Research was conducted by the method of mathematical modeling of loading freight car when driving at different speeds on straight and curved track sections. Findings. Analysis of the results shows that, for all selected freight cars for the calculation, the value of the safety factor by squeezing is smaller than the formulas of Standards. Corrections made to the formula for determining the safety factor by squeezing longitudinal forces, would achieve: 1 a higher safety factor of lightweight cars, excluding them squeezing longitudinal forces in the entire range of speeds of freight trains; 2 to develop and implement measures to prevent squeezing of cars in the entire range of motion; 3 to determine the degree of stability of the empty car in the head, middle and tail laden trains; 4 to offer optimal scheme of mixed trains formation. Originality. The analysis of existing methods for determining stability coefficient cars in freight trains from squeezing their longitudinal forces is presented in studies. Proposals are developed for the refinement of the design phase, construction and operation. Practical value. This study clarifies the existing method of determining the safety factor of stability from the squeezing longitudinal forces, as well as the influence on the magnitude of the coefficient of speed of movement of the rolling stock. Developed proposals for the refinement of existing methods for determining stability coefficient of longitudinal forces squeezing cars in a train, can reduce the number of retirements cars derailed by taking into account in the

  13. AN OVERVIEW OF LONGITUDINAL CHARACTERISTICS OF ROAD TRAFFIC FLOW

    Directory of Open Access Journals (Sweden)

    Banihan GÜNAY

    2002-02-01

    Full Text Available As multi-lane roadways have been widely used in many countries for years, analysis of two-dimensional vehicular interactions acquires special importance in highway design and operation. The simultaneous consideration of both lateral and longitudinal movements of traffic flow becomes vital in many aspects of traffic engineering, like modelling. The former component was reviewed elsewhere. In this paper, previous work on longitudinal characteristics of multi-lane traffic flow is scrutinised. Non-existence of such a review in recent literature was the main motive of the work, and it is hoped that it forms a reference report for other traffic analysts. In addition, the paper underlines a number of possible areas for future research.

  14. Longitudinal associations between personality profile stability and adjustment in college students: distinguishing among overall stability, distinctive stability, and within-time normativeness.

    Science.gov (United States)

    Klimstra, Theo A; Luyckx, Koen; Hale, William W; Goossens, Luc; Meeus, Wim H J

    2010-08-01

    In the present study, longitudinal associations of 3 aspects of personality profile stability (i.e., overall stability, distinctive stability, and within-time normativeness) with 3 adjustment measures (i.e., depressive symptoms, self-esteem, and delinquency) were examined, using 4 waves of longitudinal data on a Belgian college sample (N=565). Longitudinal path models revealed strong longitudinal associations between adjustment and overall stability. Subsequent analyses showed that it is not the degree to which one's personality profile consistently diverges from the average personality profile within a population (i.e., distinctive stability) that is related to adjustment but the degree to which a personality profile of an individual matches the average personality profile within the sample at a certain point in time (i.e., within-time normativeness). The current study thereby underscores the importance of distinguishing normativeness and distinctiveness when examining personality profile stability.

  15. Static Longitudinal Stability of a Rocket Vehicle Having a Rear-Facing Step Ahead of the Stabilizing Fins

    Science.gov (United States)

    Keynton, Robert J.

    1961-01-01

    Tests were conducted at Mach numbers of 3.96 and 4.65 in the Langley Unitary Plan wind tunnel to determine the static longitudinal stability characteristics of a fin-stabilized rocket-vehicle configuration which had a rearward facing step located upstream of the fins. Two fin sizes and planforms, a delta and a clipped delta, were tested. The angle of attack was varied from 6 deg to -6 deg and the Reynolds number based on model 6 length was about 10 x 10. The configuration with the larger fins (clipped delta) had a center of pressure slightly rearward of and an initial normal-force-curve slope slightly higher than that of the configuration with the smaller fins (delta) as would be expected. Calculations of the stability parameters gave a slightly lower initial slope of the normal-force curve than measured data, probably because of boundary-layer separation ahead of the step. The calculated center of pressure agreed well with the measured data. Measured and calculated increments in the initial slope of the normal-force curve and in the center of pressure, due to changing fins, were in excellent agreement indicating that separated flow downstream of the step did not influence flow over the fins. This result was consistent with data from schlieren photographs.

  16. The effect of the abdomen deformation on the longitudinal stability of flying insects

    Science.gov (United States)

    Choi, Sang-Yeon; Kim, Joong-Kwan; Han, Jong-seob; Han, Jae-Hung

    2015-03-01

    In this paper, we derive longitudinal nonlinear equations of motion of a hovering insect with deformable abdomen to investigate the effect of the abdominal motion to the longitudinal dynamics. The blade-element theory, which is based on experimentally obtained aerodynamic coefficients, is used for the periodic force and moment excitation to the system. Here, we focus on the role of the deformable abdomen to investigate whether or not the flexible body is a decisive factor to the longitudinal flight dynamic stability. Three cases: 1) rigid connection between the thorax and abdomen, 2) flexible connection, and 3) active connection with a feedback control, are compared to check the role of the abdomen deformation on the longitudinal flight dynamic stability, by examining eigenvalues of the linearized system model of each case. The results show that an active control of the abdominal angle can stabilize the longitudinal flight dynamics of the insect modeled in this study.

  17. Longitudinal Stability of the Beck Depression Inventory II: A Latent Trait-State-Occasion Model

    Science.gov (United States)

    Wu, Pei-Chen

    2016-01-01

    In a six-wave longitudinal study with two cohorts (660 adolescents and 630 young adults), this study investigated the longitudinal stability of the Beck Depression Inventory II (BDI-II) using the Trait-State-Occasion (TSO) model. The results revealed that the full TSO model was the best fitting representation of the depression measured by the…

  18. Longitudinal Stability Study for the FACET-II e+ Damping Ring

    CERN Document Server

    Bane, Karl

    2016-01-01

    This is an initial study of the longitudinal, single-bunch stability in the proposed FACET-II e+ damping ring. It is preliminary because many vacuum chamber objects of the ring have not yet been designed.

  19. Prediction of the effects of propeller operation on the static longitudinal stability of single-engine tractor monoplanes with flaps retracted

    Science.gov (United States)

    Weil, Joseph; Sleeman, William C , Jr

    1949-01-01

    The effects of propeller operation on the static longitudinal stability of single-engine tractor monoplanes are analyzed, and a simple method is presented for computing power-on pitching-moment curves for flap-retracted flight conditions. The methods evolved are based on the results of powered-model wind-tunnel investigations of 28 model configurations. Correlation curves are presented from which the effects of power on the downwash over the tail and the stabilizer effectiveness can be rapidly predicted. The procedures developed enable prediction of power-on longitudinal stability characteristics that are generally in very good agreement with experiment.

  20. Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack

    Directory of Open Access Journals (Sweden)

    Xin Qi

    2015-02-01

    Full Text Available Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To predict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynamics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurcation and dynamic bifurcation for high-dimensional system. Case study shows that the F-8 longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders series of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

  1. Stability and Change in Work Values: A Meta-Analysis of Longitudinal Studies

    Science.gov (United States)

    Jin, Jing; Rounds, James

    2012-01-01

    A meta-analysis of longitudinal studies was conducted to investigate stability and change in work values across the life span. Both rank-order stability and mean-level change were investigated using an integrative classification for intrinsic, extrinsic, social and status work values (Ross, Schwartz, & Surkis, 1999). Results of rank-order…

  2. Longitudinal data analysis in support of functional stability concepts for leachate management at closed municipal landfills

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, Robert D., E-mail: rdg@uchicago.edu [Center for Health Statistics, University of Chicago, 5841 S. Maryland Avenue, Chicago, IL 60637 (United States); Morris, Jeremy W.F., E-mail: jmorris@geosyntec.com [Geosyntec Consultants, 10220 Old Columbia Road, Suite A, Columbia, MD 21046 (United States); Prucha, Christopher P., E-mail: cprucha@wm.com [Groundwater Protection Program, Waste Management, 1550 Balmer Road, Box 200, Model City, NY 14107 (United States); Caldwell, Michael D., E-mail: mcaldwell@wm.com [Groundwater Protection Program, Waste Management, 3623 Wilson Road, Humble, TX 77396 (United States); Staley, Bryan F., E-mail: BStaley@erefdn.org [Environmental Research and Education Foundation, 3301 Benson Drive, Suite 301, Raleigh, NC 27609 (United States)

    2014-09-15

    Highlights: • Longitudinal data analysis using a mixed-effects regression model. • Dataset consisted of a total of 1402 samples from 101 closed municipal landfills. • Target analytes and classes generally showed predictable degradation trends. • Validates historical studies focused on macro organic indicators such as BOD. • BOD can serve as “gateway” indicator for planning leachate management. - Abstract: Landfill functional stability provides a target that supports no environmental threat at the relevant point of exposure in the absence of active control systems. With respect to leachate management, this study investigates “gateway” indicators for functional stability in terms of the predictability of leachate characteristics, and thus potential threat to water quality posed by leachate emissions. Historical studies conducted on changes in municipal solid waste (MSW) leachate concentrations over time (longitudinal analysis) have concentrated on indicator compounds, primarily chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, validation of these studies using an expanded database and larger constituent sets has not been performed. This study evaluated leachate data using a mixed-effects regression model to determine the extent to which leachate constituent degradation can be predicted based on waste age or operational practices. The final dataset analyzed consisted of a total of 1402 samples from 101 MSW landfills. Results from the study indicated that all leachate constituents exhibit a decreasing trend with time in the post-closure period, with 16 of the 25 target analytes and aggregate classes exhibiting a statistically significant trend consistent with well-studied indicators such as BOD. Decreasing trends in BOD concentration after landfill closure can thus be considered representative of trends for many leachate constituents of concern.

  3. Periodic Tail Motion Linked to Wing Motion Affects the Longitudinal Stability of Ornithopter Flight

    Institute of Scientific and Technical Information of China (English)

    Jun-seong Lee; Joong-kwan Kim; Jae-hung Han; Charles P. Ellington

    2012-01-01

    During slow level flight of a pigeon,a caudal muscle involved in tail movement,the levator caudae pars vertebralis,is activated at a particular phase with the pectoralis wing muscle.Inspired by mechanisms for the control of stability in flying animals,especially the role of the tail in avian flight,we investigated how periodic tail motion linked to motion of the wings affects the longitudinal stability of omithopter flight.This was achieved by using an integrative ornithopter flight simulator that included aeroelastic behaviour of the flexible wings and tail.Trim flight trajectories of the simulated ornithopter model were calculated by time integration of the nonlinear equations of a flexible multi-body dynamics coupled with a semi-empirical flapping-wing and tail aerodynamic models.The unique trim flight characteristics of ornithopter,Limit-Cycle Oscillation,were found under the sets of wingbeat frequency and tail elevation angle,and the appropriate phase angle of tail motion was determined by parameter studies minimizing the amplitude of the oscillations.The numerical simulation results show that tail actuation synchronized with wing motion suppresses the oscillation of body pitch angle over a wide range of wingbeat frequencies.

  4. Locus of Control and Marital Stability: A Longitudinal Study.

    Science.gov (United States)

    Constantine, John A.; Bahr, Stephen J.

    1980-01-01

    Investigated relationship between locus of control and marital stability of young men. Factors derived from locus of control measures included leadership, personal, and fate scales. Results indicated the only significant difference was on the leadership scale between men remaining married and those who did not. (RC)

  5. Longitudinal Stability of the Leadership Scale for Sports

    Science.gov (United States)

    Fletcher, Richard B.; Roberts, Margaret H.

    2013-01-01

    This study evaluated the invariance properties of the Leadership Scale for Sport in a sample of 219 female netball players over four time points within a 10-week playing season. Support was found for Chelladurai and Saleh's (1980) hypothesized 5-factor structure of the Leadership Scale for Sport. Furthermore, differential stability and partial…

  6. Longitudinal Beam Stability in the SUPER B-FACTORY

    Energy Technology Data Exchange (ETDEWEB)

    Novokhatski, A.; /SLAC; Zobov, M.; /Frascati

    2009-07-06

    We give an overview of wake fields and impedances in a proposed Super B project, which is based on extremely low emittance beams colliding at a large angle with a crab waist transformation. Understanding the effects that wake fields have on the beam is critical for a successful machine operation. We use our combined experience from the operation of the SLAC B-factory and DA{Phi}NE {Phi}-factory to eliminate strong HOM sources and minimize the chamber impedance in the Super B design. Based on a detailed study of the wake fields in this design we have developed a quasi-Green's function for the entire ring that is used to study bunch lengthening and beam stability. In particular, we check the stability threshold using numerical solutions of the Fokker-Plank equation. We also make a comparison of numerical simulations with the bunch lengthening data in the B- factory.

  7. Longitudinal Stability Study for the FACET-II e+ Damping Ring

    Energy Technology Data Exchange (ETDEWEB)

    Bane, Karl [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2016-11-29

    This is an initial study of the longitudinal, single-bunch stability in the proposed FACET-II e+ damping ring. It is preliminary because, at present, only a few specific features of the vacuum chamber are known.

  8. Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack

    Institute of Scientific and Technical Information of China (English)

    Xin Qi; Shi Zhongke

    2015-01-01

    Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To pre-dict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynam-ics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurca-tion and dynamic bifurcation for high-dimensional system. Case study shows that the F-8 longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders ser-ies of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

  9. A Longitudinal Multilevel Study of Individual Characteristics and Classroom Norms in Explaining Bullying Behaviors

    NARCIS (Netherlands)

    Sentse, Miranda; Veenstra, Rene; Kiuru, Noona; Salmivalli, Christina

    2015-01-01

    This three-wave longitudinal study was set out to examine the interplay between individual characteristics (social standing in the classroom) and descriptive and injunctive classroom norms (behavior and attitudes, respectively) in explaining subsequent bullying behavior, defined as initiating, assis

  10. Baseline patient characteristics and mortality associated with longitudinal intervention compliance.

    Science.gov (United States)

    Lin, Julia Y; Ten Have, Thomas R; Bogner, Hillary R; Elliott, Michael R

    2007-12-10

    Lin et al. (http://www.biostatsresearch.com/upennbiostat/papers/, 2006) proposed a nested Markov compliance class model in the Imbens and Rubin compliance class model framework to account for time-varying subject noncompliance in longitudinal randomized intervention studies. We use superclasses, or latent compliance class principal strata, to describe longitudinal compliance patterns, and time-varying compliance classes are assumed to depend on the history of compliance. In this paper, we search for good subject-level baseline predictors of these superclasses and also examine the relationship between these superclasses and all-cause mortality. Since the superclasses are completely latent in all subjects, we utilize multiple imputation techniques to draw inferences. We apply this approach to a randomized intervention study for elderly primary care patients with depression.

  11. Mild Cognitive Impairment is Associated with Selected Functional Markers: Integrating Concurrent, Longitudinal, and Stability Effects

    Science.gov (United States)

    Dolcos, Sanda; MacDonald, Stuart W.S.; Braslavsky, Anna; Camicioli, Richard; Dixon, Roger A.

    2013-01-01

    Objective We examined functional performance on multiple indicators for two cognitive status groups: (a) not impaired controls (NIC) and (b) mild cognitive impairment (MCI). We identified functional markers associated with differences, changes, and stability in cognitive status. Method In the Victoria Longitudinal Study (VLS) we examined cognitive status group effects in (a) cross-sectional functional performance, (b) longitudinal stability, (c) longitudinal functional performance change, and (d) functional marker prediction of later cognitive status. We assembled markers from five continuous clusters of MCI-related functional factors: biological vitality, activity lifestyle, psychosocial affect, subjective health, and global cognition. We used a cross-sectional sample and a two-wave longitudinal sample, stratified by age (mid-old, old-old) and cognitive status (MCI, NIC). Results First, cross-sectional results showed that eight markers differentiated MCI and NIC adults, with the latter performing uniformly better. The groups differed on diastolic blood pressure, body mass index, positive and negative affect, MMSE, and the lifestyle indicators of self-maintenance, travel, and novel cognitive activities. Second, Wave1 to Wave2 stabilities in cognitive status classification were high. Third, several markers differentiated the stable (NIC-to-NIC, MCI-to-MCI) from the unstable (NIC-to-MCI, MCI-to-NIC) cognitive status groups. Fourth, five relevant markers for identifying older adults at risk for cognitive status changes were: diastolic blood pressure, self-maintenance activities, novel cognitive activities, positive affect, and global cognitive status. Conclusion Selected risk and protective factors differentiate persons classified with MCI from those not currently cognitively impaired, both cross-sectionally and longitudinally. PMID:22251311

  12. Longitudinal stability of Flat Bunches with Space-Charge or Inductive Impedance

    CERN Document Server

    Santiago Gonzalez, I

    2008-01-01

    We study the loss of Landau damping for the longitudinal plane via the "Sacherer formalism". Stability limits are calculated for several longitudinal beam distributions, in particular for two types of flat bunches, which could be of interest to the LHC upgrade. The resulting stability diagrams are computed and displayed for different azimuthal modes. A general recipe is given for calculating the threshold intensity in the case of a capacitive impedance below transition or, equivalently, for a purely inductive impedance above transition. The formalism was applied to the case of the PS Booster, as an example of space-charge impedance below transition, and to the SPS, as an example of inductive impedance above transition.

  13. Study of fuzzy adaptive PID controller on thermal frequency stabilizing laser with double longitudinal modes

    Science.gov (United States)

    Mo, Qingkai; Zhang, Tao; Yan, Yining

    2016-10-01

    There are contradictions among speediness, anti-disturbance performance, and steady-state accuracy caused by traditional PID controller in the existing light source systems of thermal frequency stabilizing laser with double longitudinal modes. In this paper, a new kind of fuzzy adaptive PID controller was designed by combining fuzzy PID control technology and expert system to make frequency stabilizing system obtain the optimal performance. The experiments show that the frequency stability of the designed PID controller is similar to the existing PID controller (the magnitude of frequency stability is less than 10-9 in constant temperature and 10-7 in open air). But the preheating time is shortened obviously (from 10 minutes to 5 minutes) and the anti-disturbance capability is improved significantly (the recovery time needed after strong interference is reduced from 1 minute to 10 seconds).

  14. Longitudinal Absolute Stability of a BWB Aircraft-Pilot System with Saturated Actuator Model

    Directory of Open Access Journals (Sweden)

    Claudia Alice STATE

    2013-09-01

    Full Text Available This paper deals with the analysis of the P(ilot I(n-the-Loop O(scillations of the second category (with rate and position liming in the closed loop pilot-vehicle system, caused by the dynamic coupling between the human pilot and the aircraft. The analysis is made in the context of the longitudinal motion and the theoretical model of the airplane presented in this article is a (Blended(Wing (Body tailless configuration. In what concerns the human operator, this is expressed by the Synchronous Pilot Model, which is represented by a simple gain, without a specific delay. The Routh-Hurwitz criterion is used in order to analyze the longitudinal stability of the low-order pilot-airplane system without the influence of actuator nonlinearity (this means that the unsaturated actuator model is employed for the mentioned algebraic criterion. Most emphasis is put on the frequency Popov criterion, which is used to investigate the absolute stability property of the short-period model in the presence of the actuator rate saturation, in the condition of the Lurie problem. The transfer function of the longitudinal BWB model, obtained from open-loop analysis, has a double pole at the origin and, for the absolute stability feedback structure that contains the nonlinearity of the saturation type, the Popov frequency-domain inequalities are applied to the PIO II problem in this critical case.

  15. Investigation of the Static Longitudinal and Lateral Stability Characteristics of a 0.10-Scale Model of a Three-Stage Configuration of the Scout Research Vehicle at Mach Numbers of 2.29, 2.96, 3.96, and 4.65

    Science.gov (United States)

    Jernell, Lloyd S.

    1961-01-01

    An investigation w a s made i n the Langley Unitary Plan wind tunnel o determine the effects of fin area and the effects of antennas and w iring tunnels on the static longitudinal and lateral stability of a 0 .10- scale model of a three- stage configuration of the Scout vehicle. The tests were performed at Mach numbers of 2.29, 2.96, 3.96, and 4. 65 6 and at Reynolds numbers of about 3.5 X 10 per foot.

  16. Etiology of the stability of reading difficulties: the longitudinal twin study of reading disabilities.

    Science.gov (United States)

    Astrom, Raven L; Wadsworth, Sally J; DeFries, John C

    2007-06-01

    Results obtained from previous longitudinal studies of reading difficulties indicate that reading deficits are generally stable. However, little is known about the etiology of this stability. Thus, the primary objective of this first longitudinal twin study of reading difficulties is to provide an initial assessment of genetic and environmental influences on the stability of reading deficits. Data were analyzed from a sample of 56 twin pairs, 18 identical (monozygotic, MZ) and 38 fraternal (dizygotic, DZ), in which at least one member of each pair was classified as reading-disabled in the Colorado Learning Disabilities Research Center, and on whom follow-up data were available. The twins were tested at two time points (average age of 10.3 years at initial assessment and 16.1 years at follow-up). A composite measure of reading performance (PIAT Reading Recognition, Reading Comprehension and Spelling) was highly stable, with a stability correlation of .84. Data from the initial time point were first subjected to univariate DeFries-Fulker multiple regression analysis and the resulting estimate of the heritability of the group deficit (h2g) was .84 (+/-.26). When the initial and follow-up data were then fitted to a bivariate extension of the basic DF model, bivariate heritability was estimated at .65, indicating that common genetic influences account for approximately 75% of the stability between reading measures at the two time points.

  17. Robust stabilization control based on guardian maps theory for a longitudinal model of hypersonic vehicle.

    Science.gov (United States)

    Liu, Yanbin; Liu, Mengying; Sun, Peihua

    2014-01-01

    A typical model of hypersonic vehicle has the complicated dynamics such as the unstable states, the nonminimum phases, and the strong coupling input-output relations. As a result, designing a robust stabilization controller is essential to implement the anticipated tasks. This paper presents a robust stabilization controller based on the guardian maps theory for hypersonic vehicle. First, the guardian maps theories are provided to explain the constraint relations between the open subsets of complex plane and the eigenvalues of the state matrix of closed-loop control system. Then, a general control structure in relation to the guardian maps theories is proposed to achieve the respected design demands. Furthermore, the robust stabilization control law depending on the given general control structure is designed for the longitudinal model of hypersonic vehicle. Finally, a simulation example is provided to verify the effectiveness of the proposed methods.

  18. Longitudinal stability in reading comprehension is largely heritable from grades 1 to 6.

    Science.gov (United States)

    Soden, Brooke; Christopher, Micaela E; Hulslander, Jacqueline; Olson, Richard K; Cutting, Laurie; Keenan, Janice M; Thompson, Lee A; Wadsworth, Sally J; Willcutt, Erik G; Petrill, Stephen A

    2015-01-01

    Reading comprehension is a foundational academic skill and significant attention has focused on reading development. This report is the first to examine the stability and change in genetic and environmental influences on reading comprehension across Grades 1 to 6. This developmental range is particularly important because it encompasses the timespan in which most children move from learning how to read to using reading for learning. Longitudinal simplex models were fitted separately for two independent twin samples (N = 706; N = 976). Results suggested that the shared environment contributed to variance in early but not later reading. Instead, stability in reading development was largely mediated by continuous genetic influences. Thus, although reading is clearly a learned skill and the environment remains important for reading development, individual differences in reading comprehension appear to be also influenced by a core of genetic stability that persists through the developmental course of reading.

  19. Longitudinal stability in reading comprehension is largely heritable from grades 1 to 6.

    Directory of Open Access Journals (Sweden)

    Brooke Soden

    Full Text Available Reading comprehension is a foundational academic skill and significant attention has focused on reading development. This report is the first to examine the stability and change in genetic and environmental influences on reading comprehension across Grades 1 to 6. This developmental range is particularly important because it encompasses the timespan in which most children move from learning how to read to using reading for learning. Longitudinal simplex models were fitted separately for two independent twin samples (N = 706; N = 976. Results suggested that the shared environment contributed to variance in early but not later reading. Instead, stability in reading development was largely mediated by continuous genetic influences. Thus, although reading is clearly a learned skill and the environment remains important for reading development, individual differences in reading comprehension appear to be also influenced by a core of genetic stability that persists through the developmental course of reading.

  20. Psychological Characteristics of Chronic Depression : A Longitudinal Cohort Study

    NARCIS (Netherlands)

    Wiersma, Jenneke E.; van Oppen, Patricia; van Schaik, Digna J. F.; van der Does, A. J. Willem; Beekman, Aartjan T. E.; Penninx, Brenda W. J. H.

    Background: Few studies have investigated the importance of psychological characteristics for chronicity of depression. Knowledge about psychological differences between chronically depressed persons and nonchronically depressed persons may help to improve treatment of chronic depression. This is

  1. Characteristics, stability and outcomes of the 2011 GOLD COPD groups in the ECLIPSE cohort

    DEFF Research Database (Denmark)

    Agusti, Alvar; Edwards, Lisa D; Celli, Bartolomé

    2013-01-01

    The 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifies patients with chronic obstructive pulmonary disease (COPD) into four groups (A to D). We explored the characteristics, stability and relationship to outcomes of these groups within the ECLIPSE study (Evaluation....... The prevalence of comorbidities and persistent systemic inflammation were highest in group B. The different longitudinal behaviour of group A versus B and C versus D (each pair with similar forced expiratory volume in1 s (FEV1) values supports the 2011 GOLD proposal of assessing COPD patients by more than FEV1...

  2. Effect of winglets on a first-generation jet transport wing. 4: Stability characteristics for a full-span model at Mach 0.30

    Science.gov (United States)

    Meyer, R. R., Jr.

    1978-01-01

    The static longitudinal and lateral directional characteristics of a 0.035 scale model of a first generation jet transport were obtained with and without upper winglets. The data were obtained for take off and landing configurations at a free stream Mach number of 0.30. The results generally indicated that upper winglets had favorable effects on the stability characteristics of the aircraft.

  3. Longitudinal vibration and stability analysis of carbon nanotubes conveying viscous fluid

    Science.gov (United States)

    Oveissi, Soheil; Toghraie, Davood; Eftekhari, Seyyed Ali

    2016-09-01

    Nowadays, carbon nanotubes (CNT) play an important role in practical applications in fluidic devices. To this end, researchers have studied various aspects of vibration analysis of a behavior of CNT conveying fluid. In this paper, based on nonlocal elasticity theory, single-walled carbon nanotube (SWCNT) is simulated. To investigate and analyze the effect of internal fluid flow on the longitudinal vibration and stability of SWCNT, the equation of motion for longitudinal vibration is obtained by using Navier-Stokes equations. In the governing equation of motion, the interaction of fluid-structure, dynamic and fluid flow velocity along the axial coordinate of the nanotube and the nano-scale effect of the structure are considered. To solve the nonlocal longitudinal vibration equation, the approximate Galerkin method is employed and appropriate simply supported boundary conditions are applied. The results show that the axial vibrations of the nanotubesstrongly depend on the small-size effect. In addition, the fluid flowing in nanotube causes a decrease in the natural frequency of the system. It is obvious that the system natural frequencies reach zero at lower critical flow velocities as the wave number increases. Moreover, the critical flow velocity decreases as the nonlocal parameter increases.

  4. Floquet stability analysis of the longitudinal dynamics of two hovering model insects.

    Science.gov (United States)

    Wu, Jiang Hao; Sun, Mao

    2012-09-07

    Because of the periodically varying aerodynamic and inertial forces of the flapping wings, a hovering or constant-speed flying insect is a cyclically forcing system, and, generally, the flight is not in a fixed-point equilibrium, but in a cyclic-motion equilibrium. Current stability theory of insect flight is based on the averaged model and treats the flight as a fixed-point equilibrium. In the present study, we treated the flight as a cyclic-motion equilibrium and used the Floquet theory to analyse the longitudinal stability of insect flight. Two hovering model insects were considered-a dronefly and a hawkmoth. The former had relatively high wingbeat frequency and small wing-mass to body-mass ratio, and hence very small amplitude of body oscillation; while the latter had relatively low wingbeat frequency and large wing-mass to body-mass ratio, and hence relatively large amplitude of body oscillation. For comparison, analysis using the averaged-model theory (fixed-point stability analysis) was also made. Results of both the cyclic-motion stability analysis and the fixed-point stability analysis were tested by numerical simulation using complete equations of motion coupled with the Navier-Stokes equations. The Floquet theory (cyclic-motion stability analysis) agreed well with the simulation for both the model dronefly and the model hawkmoth; but the averaged-model theory gave good results only for the dronefly. Thus, for an insect with relatively large body oscillation at wingbeat frequency, cyclic-motion stability analysis is required, and for their control analysis, the existing well-developed control theories for systems of fixed-point equilibrium are no longer applicable and new methods that take the cyclic variation of the flight dynamics into account are needed.

  5. Parenting characteristics and adolescent psychological well-being: a longitudinal study in a Chinese context.

    Science.gov (United States)

    Shek, D T

    1999-02-01

    In this longitudinal study, the relationships between perceived parenting characteristics and adolescent psychological well-being were examined in a sample of Hong Kong Chinese adolescents (N = 378). The results indicated that global parenting styles and specific parenting behaviors are concurrently related to hopelessness, life satisfaction, self-esteem, purpose in life, and general psychiatric morbidity at Time 1 and Time 2. Longitudinal and prospective analyses (Time 1 predictors of Time 2 criterion variables) suggested that the relations between parenting characteristics and adolescent psychological well-being are bidirectional in nature. The results indicated that the strengths of association between perceived parenting characteristics and adolescent psychological well-being are stronger in female than in male adolescents. Relative to maternal parenting characteristics, paternal parenting was found to exert a stronger influence on adolescent psychological well-being.

  6. Individual and Environmental Characteristics Associated with Cognitive Development in Down Syndrome: A Longitudinal Study

    Science.gov (United States)

    Couzens, Donna; Haynes, Michele; Cuskelly, Monica

    2012-01-01

    Background: Associations among cognitive development and intrapersonal and environmental characteristics were investigated for 89 longitudinal study participants with Down syndrome to understand developmental patterns associated with cognitive strengths and weaknesses. Materials and Methods: Subtest scores of the Stanford-Binet IV collected…

  7. Individual and Environmental Characteristics Associated with Cognitive Development in Down Syndrome: A Longitudinal Study

    Science.gov (United States)

    Couzens, Donna; Haynes, Michele; Cuskelly, Monica

    2012-01-01

    Background: Associations among cognitive development and intrapersonal and environmental characteristics were investigated for 89 longitudinal study participants with Down syndrome to understand developmental patterns associated with cognitive strengths and weaknesses. Materials and Methods: Subtest scores of the Stanford-Binet IV collected…

  8. The effect of winglets on the static aerodynamic stability characteristics of a representative second generation jet transport model

    Science.gov (United States)

    Jacobs, P. F.; Flechner, S. G.

    1976-01-01

    A baseline wing and a version of the same wing fitted with winglets were tested. The longitudinal aerodynamic characteristics were determined through an angle-of-attack range from -1 deg to 10 deg at an angle of sideslip of 0 deg for Mach numbers of 0.750, 0.800, and 0.825. The lateral aerodynamic characteristics were determined through the same angle-of-attack range at fixed sideslip angles of 2.5 deg and 5 deg. Both configurations were investigated at Reynolds numbers of 13,000,000, per meter (4,000,000 per foot) and approximately 20,000,000 per meter (6,000,000 per foot). The winglet configuration showed slight increases over the baseline wing in static longitudinal and lateral aerodynamic stability throughout the test Mach number range for a model design lift coefficient of 0.53. Reynolds number variation had very little effect on stability.

  9. Measurements of control stability characteristics of a wind-tunnel model using a transfer function method

    Science.gov (United States)

    Chopra, I.; Ballard, J. D.

    1980-01-01

    Recent state-of-the-art techniques in rotor systems include the use of active feedback to augment the dynamic control characteristics of an aircraft system. A recent test of a stoppable rotor with blade circulation blowing was conducted in the Ames Research Center's 40by 80-ft wind tunnel. A major part of the test schedule was dedicated to the acquisition of data to determine the stability of a closed-loop hub-moment feedback control system. Therefore, the open-loop control response was measured at several flight conditions to ascertain the stability of the system prior to the final closed-loop feedback control test. Measurements were made during both the stopped and rotating rotor modes, and open-loop Bode plots were obtained for the control loops associated with the moments about the longitudinal and lateral axis.

  10. PROPAGATION CHARACTERISTICS OF HIGH ORDER LONGITUDINAL MODES IN STEEL STRANDS AND THEIR APPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    Zenghua Liu; Su Liu; Bin Wu; Yinong Zhang; Cunfu He

    2008-01-01

    Propagation characteristics of high order longitudinal modes of ultrasonic guided waves in seven-wire steel strands are investigated theoretically and experimentally. According to these analysis results, proper longitudinal modes are selected for defect detection in steel strands.Dispersion curves for helical and central wires in a 17.80 mm nominal diameter seven-wire steel strand are numerically obtained firstly, and propagation characteristics of high-order longitudinal modes, such as wave structures, attenuation and dispersion, are analyzed. In experiments, the signals of ultrasonic guided wave at different high frequencies are excited and received at one end of a steel strand by using the same single piezoelectric transducer. The identification of longitudinal modes in the received signals is achieved based on short time Fourier transform. Furthermore,appropriate L(0, 5) mode at 2.54 MHz is chosen for detecting an artificial defect in a helical wire of the steel strand. Results show that high order longitudinal modes in a high frequency range with low dispersion and attenuation whose energy propagates mainly in the center of the wires can be used for defect detection in long range steel strands.

  11. A longitudinal investigation into the progression of dynamic postural stability performance in adolescents.

    Science.gov (United States)

    Holden, Sinéad; Boreham, Colin; Doherty, Cailbhe; Wang, Dana; Delahunt, Eamonn

    2016-07-01

    Adolescent female athletes have a higher incidence of certain non-contact lower limb injuries compared to their male counterparts. Decreased postural stability is an established risk factor for lower limb injuries; however developmental-related sex differences in postural stability during adolescence have not been investigated. The objectives of this study were to longitudinally examine changes over time, and potential sex differences in dynamic postural stability performance in adolescents. One hundred and eighty four adolescent athletes participated (mean age=13±0.34 years). Participants were assessed, using the Star Excursion Balance Test (SEBT) at baseline (T1) and at 6 (T2), 12 (T3), 18 (T4) and 24 (T5) months. At each time-point, participants performed 3 trials of the anterior, posterior-medial and posterior-lateral directions of the SEBT on each limb. Reach distance for each direction was averaged across the 3 trials normalised to leg length. General linear mixed model analyses were carried out on each of the dependant variables (reach directions) with sex and time as the categorical independent variables. There was a significant sex×time interaction for the posterior-lateral reach distance scores. There were no significant sex×time interactions for any of the other reach directions. Males increased performance on the posterior-lateral reach direction from T1 to T5, while females only increased performance until T3. Young males and females demonstrate diverging postural stability profiles during adolescence.

  12. Stabilizing effects on 2D channel flow due to longitudinal wall oscillation

    Science.gov (United States)

    Atobe, Takashi

    2017-01-01

    Stabilizing effect of longitudinal wall oscillation on two dimensional channel flow is analytically investigated. Model flow considered here is constituted of a superposition of the plane Poiseuille flow and the Stokes layer. The two walls are periodically oscillated in phase. Since the present system has a periodicity, the Floquet method is employed for the stability analysis. For this, a partial difference equation with a periodic function is derived from the time dependent version of the Orr-Sommerfeld equation using the Chebyshev spectral collocation method. The parameters governing the present system are the Reynolds number Re, the period Ω and amplitude Uw of the wall oscillation. Depending on the parameters, it is found that the 2D Tollmein-Shlichtin (TS) modes can be stabilized by the wall oscillation. Furthermore there are some case that 2D TS modes are more stabilized than the oblique TS mode. These results suggest that the oblique TS mode can appear earlier than the TS mode contrary to the Squire's Theorem.

  13. Wind-Tunnel Investigation of Effects of Unsymmetrical Horizontal-Tail Arrangements on Power-on Static Longitudinal Stability of a Single-Engine Airplane Model

    Science.gov (United States)

    Purser, Paul E.; Spear, Margaret F.

    1947-01-01

    A wind-tunnel investigation has been made to determine the effects of unsymmetrical horizontal-tail arrangements on the power-on static longitudinal stability of a single-engine single-rotation airplane model. Although the tests and analyses showed that extreme asymmetry in the horizontal tail indicated a reduction in power effects on longitudinal stability for single-engine single-rotation airplanes, the particular "practical" arrangement tested did not show marked improvement. Differences in average downwash between the normal tail arrangement and various other tail arrangements estimated from computed values of propeller-slipstream rotation agreed with values estimated from pitching-moment test data for the flaps-up condition (low thrust and torque) and disagreed for the flaps-down condition (high thrust and torque). This disagreement indicated the necessity for continued research to determine the characteristics of the slip-stream behind various propeller-fuselage-wing combinations. Out-of-trim lateral forces and moments of the unsymmetrical tail arrangements that were best from consideration of longitudinal stability were no greater than those of the normal tail arrangement.

  14. Stability characteristics of the 500 mw Indian PFBR

    Directory of Open Access Journals (Sweden)

    Anuraj Vijayan L.

    2015-01-01

    Full Text Available After the successful operation of the fast breeder test reactor for over two decades, India is now nearing the completion of a 500 MW (electrical prototype fast breeder reactor. This commercial scale power reactor is a sodium-cooled, pool-type, mixed-oxide fuelled fast reactor. The stability characteristics of the reactor are an important safety aspect to be studied. In the present work, linear stability of the prototype fast breeder reactor analysis is carried out using the transfer function method, while the stability of the system is checked via the Nyquist criteria. For the completeness of the study, transient analysis with various kinds of reactivity perturbations was carried out. The response of the system in both cases indicated that the system is stable.

  15. Euclidean distance and Kolmogorov-Smirnov analyses of multi-day auditory event-related potentials: a longitudinal stability study

    Science.gov (United States)

    Durato, M. V.; Albano, A. M.; Rapp, P. E.; Nawang, S. A.

    2015-06-01

    The validity of ERPs as indices of stable neurophysiological traits is partially dependent on their stability over time. Previous studies on ERP stability, however, have reported diverse stability estimates despite using the same component scoring methods. This present study explores a novel approach in investigating the longitudinal stability of average ERPs—that is, by treating the ERP waveform as a time series and then applying Euclidean Distance and Kolmogorov-Smirnov analyses to evaluate the similarity or dissimilarity between the ERP time series of different sessions or run pairs. Nonlinear dynamical analysis show that in the absence of a change in medical condition, the average ERPs of healthy human adults are highly longitudinally stable—as evaluated by both the Euclidean distance and the Kolmogorov-Smirnov test.

  16. Characteristics, stability and outcomes of the 2011 GOLD COPD groups in the ECLIPSE cohort.

    Science.gov (United States)

    Agusti, Alvar; Edwards, Lisa D; Celli, Bartolomé; Macnee, William; Calverley, Peter M A; Müllerova, Hana; Lomas, David A; Wouters, Emiel; Bakke, Per; Rennard, Steve; Crim, Courtney; Miller, Bruce E; Coxson, Harvey O; Yates, Julie C; Tal-Singer, Ruth; Vestbo, Jørgen

    2013-09-01

    The 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifies patients with chronic obstructive pulmonary disease (COPD) into four groups (A to D). We explored the characteristics, stability and relationship to outcomes of these groups within the ECLIPSE study (Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points) (n = 2101). Main results showed that: 1) these groups differed in several clinical, functional, imaging and biological characteristics in addition to those used for their own definition; 2) A and D groups were relatively stable over time, whereas groups B and C showed more temporal variability; 3) the risk of exacerbation over 3 years increased progressively from A to D, whereas that of hospitalisation and mortality were lowest in A, highest in D and intermediate and similar in B and C, despite the former having milder airflow limitation. The prevalence of comorbidities and persistent systemic inflammation were highest in group B. The different longitudinal behaviour of group A versus B and C versus D (each pair with similar forced expiratory volume in1 s (FEV1) values supports the 2011 GOLD proposal of assessing COPD patients by more than FEV1 only. However the assumption that symptoms do not equate to risk appears to be naïve, as groups B and C carry equally poor clinical outcomes, though for different reasons.

  17. A Longitudinal Study of Reading Comprehension Achievement from Grades 3 to 10: Investigating Models of Stability, Cumulative Growth, and Compensation

    Science.gov (United States)

    Kwiatkowska-White, Bozena; Kirby, John R.; Lee, Elizabeth A.

    2016-01-01

    This longitudinal study of 78 Canadian English-speaking students examined the applicability of the stability, cumulative, and compensatory models in reading comprehension development. Archival government-mandated assessments of reading comprehension at Grades 3, 6, and 10, and the Canadian Test of Basic Skills measure of reading comprehension…

  18. Stability and Change in Executive Function Abilities from Late Adolescence to Early Adulthood: A Longitudinal Twin Study

    Science.gov (United States)

    Friedman, Naomi P.; Miyake, Akira; Altamirano, Lee J.; Corley, Robin P.; Young, Susan E.; Rhea, Sally Ann; Hewitt, John K.

    2016-01-01

    Executive functions (EFs)--the higher level cognitive abilities that enable us to control our own thoughts and actions--continue to develop into early adulthood, yet no longitudinal study has examined their stability during the important life transition from late adolescence to young adulthood. In this twin study (total N = 840 individuals from…

  19. A Longitudinal Study of Reading Comprehension Achievement from Grades 3 to 10: Investigating Models of Stability, Cumulative Growth, and Compensation

    Science.gov (United States)

    Kwiatkowska-White, Bozena; Kirby, John R.; Lee, Elizabeth A.

    2016-01-01

    This longitudinal study of 78 Canadian English-speaking students examined the applicability of the stability, cumulative, and compensatory models in reading comprehension development. Archival government-mandated assessments of reading comprehension at Grades 3, 6, and 10, and the Canadian Test of Basic Skills measure of reading comprehension…

  20. Review of Combustion Stability Characteristics of Swirl Coaxial Element Injectors

    Science.gov (United States)

    Hulka, J. R.; Casiano, M. J.

    2013-01-01

    Liquid propellant rocket engine injectors using coaxial elements where the center liquid is swirled have become more common in the United States over the past several decades, although primarily for technology or advanced development programs. Currently, only one flight engine operates with this element type in the United States (the RL10 engine), while the element type is very common in Russian (and ex-Soviet) liquid propellant rocket engines. In the United States, the understanding of combustion stability characteristics of swirl coaxial element injectors is still very limited, despite the influx of experimental and theoretical information from Russia. The empirical and theoretical understanding is much less advanced than for the other prevalent liquid propellant rocket injector element types, the shear coaxial and like-on-like paired doublet. This paper compiles, compares and explores the combustion stability characteristics of swirl coaxial element injectors tested in the United States, dating back to J-2 and RL-10 development, and extending to very recent programs at the NASA MSFC using liquid oxygen and liquid methane and kerosene propellants. Included in this study are several other relatively recent design and test programs, including the Space Transportation Main Engine (STME), COBRA, J-2X, and the Common Extensible Cryogenic Engine (CECE). A presentation of the basic data characteristics is included, followed by an evaluation by several analysis techniques, including those included in Rocket Combustor Interactive Design and Analysis Computer Program (ROCCID), and methodologies described by Hewitt and Bazarov.

  1. Free-flight investigation of the stability and control characteristics of a STOL model with an externally blown jet flap

    Science.gov (United States)

    Parlett, L. P.; Emerling, S. J.; Phelps, A. E., III

    1974-01-01

    The stability and control characteristics of a four-engine turbofan STOL transport model having an externally blown jet flap have been investigated by means of the flying-model technique in the Langley full-scale tunnel. The flight characteristics of the model were investigated under conditions of symmetric and asymmetric (one engine inoperative) thrust at lift coefficients up to 9.5 and 5.5, respectively. Static characteristics were studied by conventional power-on force tests over the flight-test angle-of-attack range including the stall. In addition to these tests, dynamic longitudinal and lateral stability calculations were performed for comparison with the flight-test results and for use in correlating the model results with STOL handling-qualities criteria.

  2. Longitudinal Vibration Characteristics Required to Cut a Circle by Ultrasonic Vibration

    Science.gov (United States)

    Takuya Asami,; Hikaru Miura,

    2010-07-01

    Currently, lasers and water jets are used to cut circles in brittle materials such as ceramics. However, a disadvantage of these methods is that the conventional equipment is large and complex. To resolve this issue, a method using the ultrasonic vibration of a hollow-type stepped horn for cutting is developed. We consider that this equipment can be simplified and miniaturized. The shape of the hollow-type stepped horn and the characteristics of the longitudinal vibration required to obtain excellent cutting properties were examined. As a result, the most appropriate depth of the hollow part is one-quarter of the wavelength for a hollow-type stepped horn that vibrates longitudinally. The amplification factor is proportional to the cross-sectional ratio providing the cross-sectional ratio does not exceed 4.6. The characteristics of the longitudinal vibration of the hollow-type stepped horn when the static pressing force at the tip of the horn is varied were also examined. It was clarified that the ultrasonic vibration of a hollow-type stepped horn can be used to cut brittle materials.

  3. Unstructured Grid Euler Method Assessment for Longitudinal and Lateral/Directional Stability Analysis of the HSR Reference H Configuration at Transonic Speeds

    Science.gov (United States)

    Ghaffari, Farhad

    1999-01-01

    Transonic Euler computations, based on unstructured grid methodology, are performed for a proposed High Speed Civil Transport (HSCT) configuration, designated as the Reference H configuration within the High Speed Research (HSR) Program. The predicted results are correlated with appropriate experimental wind-tunnel data for the baseline configuration with and without control surface deflections for a range of angle of attack at M(sub infinity) = 0.95. Good correlations between the predictions and measured data have been obtained for the longitudinal aerodynamic characteristics of the baseline configuration. The incremental effects in the longitudinal aerodynamic characteristics due to horizontal rail deflections as well as wing leading-edge and trailing-edge flap deflections have also been predicted reasonably well. Computational results and correlations with data are also presented for the lateral and directional stability characteristics for a range of angle of attack at a constant sideslip angle as well as a range of sideslip angles at a constant angle of attack. In addition, the results are presented to assess the computational method performance and convergence characteristics.

  4. Personality traits below facets: The consensual validity, longitudinal stability, heritability, and utility of personality nuances.

    Science.gov (United States)

    Mõttus, René; Kandler, Christian; Bleidorn, Wiebke; Riemann, Rainer; McCrae, Robert R

    2017-03-01

    It has been argued that facets do not represent the bottom of the personality hierarchy-even more specific personality characteristics, nuances, could be useful for describing and understanding individuals and their differences. Combining 2 samples of German twins, we assessed the consensual validity (correlations across different observers), rank-order stability, and heritability of nuances. Personality nuances were operationalized as the 240 items of the Revised NEO Personality Inventory (NEO-PI-R). Their attributes were examined by analyzing item residuals, controlling for the variance of the facet the item had been assigned to and all other facets. Most nuances demonstrated significant (p personality traits, with median estimates of rank-order stability and heritability being .77 and .52, respectively. Few nuances demonstrated robust associations with age and gender, but many showed incremental, conceptually meaningful, and replicable (across methods and/or samples) predictive validity for a range of interest domains and body mass index. We argue that these narrow personality characteristics constitute a valid level of the personality hierarchy. They may be especially useful for providing a deep and contextualized description of the individual, but also for the prediction of specific outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Stabilized and tunable single-longitudinal-mode erbium fiber laser employing ytterbium-doped fiber based interference filter

    Science.gov (United States)

    Yeh, Chien-Hung; Tsai, Ning; Zhuang, Yuan-Hong; Chow, Chi-Wai; Chen, Jing-Heng

    2017-02-01

    In this demonstration, to achieve stabilized and wavelength-selectable single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser, a short length of ytterbium-doped fiber (YDF) is utilized to serve as a spatial multi-mode interference (MMI) inside a fiber cavity for suppressing multi-longitudinal-mode (MLM) significantly. In the measurement, the output powers and optical signal to noise ratios (OSNRs) of proposed EDF ring laser are measured between -9.85 and -5.71 dBm; and 38.03 and 47.95 dB, respectively, in the tuning range of 1530.0-1560.0 nm. In addition, the output SLM and stability performance are also analyzed and discussed experimentally.

  6. Characteristic systolic waveform of left ventricular longitudinal strain rate in patients with hypertrophic cardiomyopathy.

    Science.gov (United States)

    Okada, Kazunori; Kaga, Sanae; Mikami, Taisei; Masauzi, Nobuo; Abe, Ayumu; Nakabachi, Masahiro; Yokoyama, Shinobu; Nishino, Hisao; Ichikawa, Ayako; Nishida, Mutsumi; Murai, Daisuke; Hayashi, Taichi; Shimizu, Chikara; Iwano, Hiroyuki; Yamada, Satoshi; Tsutsui, Hiroyuki

    2016-10-18

    We analyzed the waveform of systolic strain and strain-rate curves to find a characteristic left ventricular (LV) myocardial contraction pattern in patients with hypertrophic cardiomyopathy (HCM), and evaluated the utility of these parameters for the differentiation of HCM and LV hypertrophy secondary to hypertension (HT). From global strain and strain-rate curves in the longitudinal and circumferential directions, the time from mitral valve closure to the peak strains (T-LS and T-CS, respectively) and the peak systolic strain rates (T-LSSR and T-CSSR, respectively) were measured in 34 patients with HCM, 30 patients with HT, and 25 control subjects. The systolic strain-rate waveform was classified into 3 patterns ("V", "W", and "√" pattern). In the HCM group, T-LS was prolonged, but T-LSSR was shortened; consequently, T-LSSR/T-LS ratio was distinctly lower than in the HT and control groups. The "√" pattern of longitudinal strain-rate waveform was more frequently seen in the HCM group (74 %) than in the control (4 %) and HT (20 %) groups. Similar but less distinct results were obtained in the circumferential direction. To differentiate HCM from HT, the sensitivity and specificity of the T-LSSR/T-LS ratio waveform were 85 and 63 %, and 74 and 80 %, respectively. In conclusion, in patients with HCM, a reduced T-LSSR/T-LS ratio and a characteristic "√"-shaped waveform of LV systolic strain rate was seen, especially in the longitudinal direction. The timing and waveform analyses of systolic strain rate may be useful to distinguish between HCM and HT.

  7. Dynamic-Stability Characteristics of Premixed Methane Oxy-Combustion

    KAUST Repository

    Shroll, Andrew P.

    2012-01-01

    This work explores the dynamic stability characteristics of premixed CH 4/O 2/CO 2 mixtures in a 50 kW swirl stabilized combustor. In all cases, the methane-oxygen mixture is stoichiometric, with different dilution levels of carbon dioxide used to control the flame temperature (T ad). For the highest T ad\\'s, the combustor is unstable at the first harmonic of the combustor\\'s natural frequency. As the temperature is reduced, the combustor jumps to fundamental mode and then to a low-frequency mode whose value is well below the combustor\\'s natural frequency, before eventually reaching blowoff. Similar to the case of CH 4/air mixtures, the transition from one mode to another is predominantly a function of the T ad of the reactive mixture, despite significant differences in laminar burning velocity and/or strained flame consumption speed between air and oxy-fuel mixtures for a given T ad. High speed images support this finding by revealing similar vortex breakdown modes and thus similar turbulent flame geometries that change as a function of flame temperature. Copyright © 2012 American Society of Mechanical Engineers.

  8. Some constructions and characteristics of rod-type piezoelectric ultrasonic motors using longitudinal and torsional vibrations.

    Science.gov (United States)

    Tomikawa, Y; Adachi, K; Aoyagi, M; Sagae, T; Takano, T

    1992-01-01

    Ultrasonic motors using longitudinal and torsional motions of rod vibrators have previously been proposed. Several motor constructions, whose forms are different from the previous ones, are proposed and their characteristics are experimentally examined in order to develop the ultrasonic motors of this type; that is, they are expected to have much different uses, according to how their forms are modified. Two groups of motor are dealt with: one contains motors basically suited to the relatively high torque of 2-3 kgf-cm and the other contains motors for small or medium torque below about 1.0 kgf-cm. As the result, operational characteristics of motors are totally revealed. These are useful in developing the rod type ultrasonic motors and in their practical applications.

  9. Coupled flexural-longitudinal vibration of delaminated composite beams with local stability analysis

    Science.gov (United States)

    Szekrényes, András

    2014-09-01

    A novel analytical model is developed to solve the problem of free vibration of delaminated composite beams. The beam with a single delamination was modelled by six equivalent single layers by establishing the kinematic continuity in the undelaminated portion of the system. In the delaminated region the layers were captured by the traditional theories. First, Timoshenko beam theory is applied to solve the problem, then by reducing the model, the corresponding Euler-Bernoulli solution is presented. Both the free and constrained models were considered. The most important aspect of the present analysis is that the beams of the delaminated region are subjected to normal forces, as well. That is the essential reason for leading to a coupled flexural-longitudinal vibration problem. It is also concluded that delamination buckling can take place if the normal force is compressive in one of the half-periods of the vibration and reaches a critical value. The problem was also investigated experimentally by modal hammer and sweep excitation tests on beams made of E-glass/polyester in order to measure the natural frequencies and mode shapes. The comparison of the analytical and experimental results indicates the importance of the independent rotations provided by Timoshenko beams over the simple beam theory. The delamination buckling of the beams was captured based on the static stability analysis in the first step. Further results show that the problem is more complex than it was thought before, e.g., some nonlinearity, time-dependent stiffness as well as parametric excitation aspects were discovered during the present analysis.

  10. Wind-Tunnel Investigation of Subsonic Longitudinal Aerodynamic Characteristics of a Tiltable-Wing Vertical-Take-Off-and-Landing Supersonic Bomber Configuration Including Turbojet Power Effects

    Science.gov (United States)

    Thompson, Robert F.; Vogler, Raymond D.; Moseley, William C., Jr.

    1959-01-01

    Jet-powered model tests were made to determine the low-speed longitudinal aerodynamic characteristics of a vertical-take-off and-landing supersonic bomber configuration. The configuration has an unique engine-wing arrangement wherein six large turbojet engines (three on each side of the fuselage) are buried in a low-aspect-ratio wing which is tilted into the vertical plane for take-off. An essentially two-dimensional variable inlet, spanning the leading edge of each wing semispan, provides air for the engines. Jet flow conditions were simulated for a range of military (nonafterburner) and afterburner turbojet-powered flight at subsonic speeds. Three horizontal tails were tested at a station down-stream of the jet exit and at three heights above the jet axes. A semi-span model was used and test parameters covered wing-fuselage incidence angles from 0 deg to 15 deg, wing angles of attack from -4 deg to 36 deg, a variable range of horizontal-tail incidence angles, and some variations in power simulation conditions. Results show that, with all horizontal tails tested, there were large variations in static stability throughout the lift range. When the wing and fuselage were alined, the model was statically stable throughout the test range only with the largest tail tested (tail span of 1.25 wing span) and only when the tail was located in the low test position which placed the tail nearest to the undeflected jet. For transition flight conditions, none of the tail configurations provided satisfactory longitudinal stability or trim throughout the lift range. Jet flow was destabilizing for most of the test conditions, and varying the jet-exit flow conditions at a constant thrust coefficient had little effect on the stability of this model. Wing leading-edge simulation had some important effects on the longitudinal aerodynamic characteristics.

  11. Seismotectonic characteristics of the northernmost part of the Longitudinal Valley suture, eastern Taiwan

    Science.gov (United States)

    Shyu, J. H.; Chen, C.; Wu, Y.

    2012-12-01

    The island of Taiwan is located at the collisional boundary between the Philippine Sea and the Eurasian plates. In eastern Taiwan, the Longitudinal Valley between the Central Range and the Coastal Range is generally considered as the suture zone. The Ryukyu subduction system, on the other hand, extends southwestward from offshore eastern Taiwan, and intersects with the northernmost Longitudinal Valley suture. As a result, this area is characterized by frequent earthquakes and complex geological structures. Although there have been several tectonic investigations in this area, detailed knowledge of seismotectonic characteristics of this complicated region is still very limited. Recently, we have obtained high resolution earthquake data by combining records from seismic stations of the Japan Meteorological Agency (JMA) and data from Taiwan Central Weather Bureau Seismic Network (CWBSN) and Taiwan Strong Motion Instrumentation Program (TSMIP). Therefore, we attempted to analyze this area in detail using these high resolution seismic data, together with tectonic geomorphic investigations. The distribution of background seismicity shows that many earthquakes occurred at about 10 km deep in this area, and a linear seismicity band extends to the surface west of the Hualien City. We infer that this band of seismicity represents a structure that crops out within the eastern flank of the Central Range. This structure would be different from the Milun fault, which is a known structure in the Hualien area and ruptured during an M7.3 earthquake in October 1951. Another major feature in this area is a listric band of seismicity that appears to extend to the surface near the Liwu River mouth, north of the Hualien City. This seismicity band likely represents an E-W striking structure that dips to the south. Based on the focal mechanisms of several recent moderate earthquakes that occurred within these seismic bands, we suggest that these two structures are reverse faults. These

  12. Effect of Artificial Pitch Damping on the Longitudinal and Rolling Stability of Aircraft with Negative Static Margins

    Science.gov (United States)

    Moul, Martin T.; Brown, Lawrence W.

    1959-01-01

    A preliminary theoretical investigation has been made of the short-period longitudinal and steady-rolling (inertia coupling) stability of a hypersonic glider configuration for center-of-gravity locations rear-ward of the airplane neutral point. Such center-of-gravity positions for subsonic flight would improve performance by reducing supersonic and hypersonic static margins and trim drag. Results are presented of stability calculations and a simulator study for a velocity of 700 ft/sec and an altitude of 401,000 feet. With no augmentation, the airplane was rapidly divergent and was considered unsatisfactory in the simulator study. When a pitch damper was employed as a stability augmenter, the short-period mode became overdamped, and the airplane was easily controlled on the simulator. A steady-rolling analysis showed that the airplane can be made free of rolling divergence for all roll rates with an appropriate damper gain.

  13. New literal approximations for the longitudinal dynamic characteristics of flexible flight vehicles

    Science.gov (United States)

    Livneh, Rafael; Schmidt, David K.

    1992-01-01

    The goal of the literal approximation method is to obtain simple literal (analytical) approximations for key dynamic characteristics of flexible flight vehicles. A basic question regarding the method is its usefulness as an additional design tool for existing design and simulation procedures. Two aspects of this question are: (1) ease of derivation and use of the literal approximations, and (2) the suitability of one set of literal approximations to describe the dynamics of a large set of significantly different vehicles. These issues are addressed by incorporating symbolic manipulation software into the literal approximation method for the analysis of a fifth order model of the longitudinal dynamics of a flexible flight vehicle. The automated literal approximation generated in this fashion reduces the manual derivation time by an approximate factor of four. A single set of literal approximations is shown to provide adequate approximations for the dynamics of significantly different flight vehicles configurations, such as an aircraft, a missile, and a hypersonic vehicle.

  14. East-West Couples: Distribution, Characteristics and Stability

    Directory of Open Access Journals (Sweden)

    Daniel Lois

    2014-12-01

    Full Text Available Der Originalbeitrag in deutscher Sprache ist verfügbar unter: Bd. 40 (2015: Ausgewählte deutsche Beiträge.SOEP data were used to examine relationships consisting of one partner socialised in West Germany and one in East Germany and who presently reside in the “old” (former West German or “new” (newly formed East German federal states. The estimated share of east-west couples among all marriages or cohabiting couples rises continuously within the observed period reaching approximately two and eleven percent respectively by 2009. The specific characteristics of east-west couples are that their employment-related division of labour is relatively egalitarian, above-average the partners are of different confessions and practice different religions, at least one of the partners is frequently divorced and there is also a strong tendency towards unmarried cohabitation. Besides the place of socialisation, the present place of residence has an independent impact on the economic situation, division of labour and marriage propensity. Analyses of relationship stability reveal that east-west couples exhibit a relatively high risk of separation. This is partly due to religious differences between the partners, but primarily to the low marriage propensity and the overrepresentation of divorced persons within this type of relationship.

  15. How changes in psychosocial job characteristics impact burnout in nurses: a longitudinal analysis.

    Directory of Open Access Journals (Sweden)

    Renato Pisanti

    2016-07-01

    Full Text Available The main aim of this longitudinal study was to test the Job Demand-Control-Support (JDCS model and to analyze whether changes in psychosocial job characteristics are related to (changes in burnout. Previous studies on the effects of JDCS variables on burnout dimensions have indicated that the iso strain hypothesis (i.e., high job demands, low control and low support additively predict high stress reactions and the buffer hypotheses (i.e., high job control and/or social support is expected to moderate the negative impact of high demands on stress reactions have hardly been examined concurrently in a longitudinal design; and that the effects of changes of psychosocial job variables on burnout dimensions have hardly been analysed. This two wave study was carried out over a period of 14 months in a sample of 217 Italian nurses.Method: Hierarchical regression analyses were used to test the cross lagged main and interactive effects of JDCS variables, and to analyse the across-time effects of changes in JDCS dimensions on burnout variables.The Time 1 job characteristics explained 2 to 8% of the variance in the Time 2 burnout dimensions, but no support for the additive or the buffer hypothesis of the JDCS model was found. Changes in job characteristics explained an additional 3 to 20% of variance in the Time 2 burnout dimensions. Specifically, high levels of emotional exhaustion at Time 2 were explained by high levels of social support at Time 1, and unfavourable changes in demands, control and support over time; high depersonalisation at Time 2 was explained by high social support at time 1 and by an increase in demands over time; and high personal accomplishment at Time 2 was predicted by high demands, high control, interactive effect demands X control X social support, at Time 1, and by a decrease in demands over time. No reversed effects of burnout on work characteristics have been found.Our findings suggest that the work environment is subject to

  16. Longitudinal hierarchical linear modeling analyses of California Psychological Inventory data from age 33 to 75: an examination of stability and change in adult personality.

    Science.gov (United States)

    Jones, Constance J; Livson, Norman; Peskin, Harvey

    2003-06-01

    Twenty aspects of personality assessed via the California Psychological Inventory (CPI; Gough & Bradley, 1996) from age 33 to 75 were examined in a sample of 279 individuals. Oakland Growth Study and Berkeley Guidance Study members completed the CPI a maximum of 4 times. We used longitudinal hierarchical linear modeling (HLM) to ask the following: Which personality characteristics change and which do not? Five CPI scales showed uniform lack of change, 2 showed heterogeneous change giving an averaged lack of change, 4 showed linear increases with age, 2 showed linear decreases with age, 4 showed gender or sample differences in linear change, 1 showed a quadratic peak, and 2 showed a quadratic nadir. The utility of HLM becomes apparent in portraying the complexity of personality change and stability.

  17. K-ABC Stability in a Preschool Sample: A Longitudinal Study.

    Science.gov (United States)

    Smith, Douglas K.; And Others

    Over a 2-year period, stability of performance on the Kaufman Assessment Battery for Children of 25 nonhandicapped preschool children was examined. Overall, results indicated a high level of stability for both global scale scores and subtest scores. Less stability was indicated for performance patterns and subtest strengths and weaknesses. (PCB)

  18. Technique of calculating and studying stability of three dimensional velocity fields of longitudinal waves

    Energy Technology Data Exchange (ETDEWEB)

    Pivovarova, N.B.; Slavina, L.B.

    1981-01-01

    The features of a technique for determining the velocity of spread of longitudinal waves in the epicenter zone are briefly formulated. Results are presented from studying the technique in the example of model and experimental data in the focal zone of Kamchatka.

  19. Are eating and psychosocial characteristics in early teenage years useful predictors of eating characteristics in early adulthood? A 7-year longitudinal study.

    Science.gov (United States)

    Calam, R; Waller, G

    1998-12-01

    This longitudinal research aimed to determine the utility of psychosocial and eating characteristics in early teenage years in predicting eating attitudes and behaviors in early adulthood. Self-esteem, perfectionism, family function, and eating attitudes were measured at 12 years and eating attitudes and behavior were assessed at 19 years. Sixty-three women (71.6%) remained in the study over the 7 years. Bulimic attitudes in early teenage years were related to subsequent bulimic features, while restrictive attitudes were more closely related to later purging behaviors. Self-esteem and perfectionism were only weakly linked with subsequent eating. However, different perceived family characteristics at the first stage were associated with specific aspects of eating in early adulthood. There is consistency of eating characteristics across time, but psychosocial characteristics have a more limited predictive power. Future longitudinal studies should begin earlier in childhood if psychosocial factors are to be useful predictors of eating psychopathology in adulthood.

  20. Hurricane Isaac: A Longitudinal Analysis of Storm Characteristics and Power Outage Risk.

    Science.gov (United States)

    Tonn, Gina L; Guikema, Seth D; Ferreira, Celso M; Quiring, Steven M

    2016-10-01

    In August 2012, Hurricane Isaac, a Category 1 hurricane at landfall, caused extensive power outages in Louisiana. The storm brought high winds, storm surge, and flooding to Louisiana, and power outages were widespread and prolonged. Hourly power outage data for the state of Louisiana were collected during the storm and analyzed. This analysis included correlation of hourly power outage figures by zip code with storm conditions including wind, rainfall, and storm surge using a nonparametric ensemble data mining approach. Results were analyzed to understand how correlation of power outages with storm conditions differed geographically within the state. This analysis provided insight on how rainfall and storm surge, along with wind, contribute to power outages in hurricanes. By conducting a longitudinal study of outages at the zip code level, we were able to gain insight into the causal drivers of power outages during hurricanes. Our analysis showed that the statistical importance of storm characteristic covariates to power outages varies geographically. For Hurricane Isaac, wind speed, precipitation, and previous outages generally had high importance, whereas storm surge had lower importance, even in zip codes that experienced significant surge. The results of this analysis can inform the development of power outage forecasting models, which often focus strictly on wind-related covariates. Our study of Hurricane Isaac indicates that inclusion of other covariates, particularly precipitation, may improve model accuracy and robustness across a range of storm conditions and geography.

  1. Stabilization of oral anticoagulant therapy in hospitalized patients and characteristics associated with lack of stabilization

    NARCIS (Netherlands)

    van den Bemt, PMLA; Joosten, P; Risselada, A; van den Boogaart, MHA; Egberts, ACG; Brouwers, JRBJ

    2000-01-01

    The initiation and stabilization of oral anticoagulant therapy in hospitalized patients in a setting without specialized medical or pharmaceutical advice, was studied. In addition, potential risk factors for lack of stabilization were studied. All patients from three wards (orthopaedic surgery, gene

  2. Process for stabilizing the viscosity characteristics of coal derived materials and the stabilized materials obtained thereby

    Energy Technology Data Exchange (ETDEWEB)

    Bronfenbrenner, James C. (Allentown, PA); Foster, Edward P. (Allentown, PA); Tewari, Krishna (Allentown, PA)

    1985-01-01

    A process is disclosed for stabilizing the viscosity of coal derived materials such as an SRC product by adding up to 5.0% by weight of a light volatile phenolic viscosity repressor. The viscosity will remain stabilized for a period of time of up to 4 months.

  3. Process for stabilizing the viscosity characteristics of coal derived materials and the stabilized materials obtained thereby

    Energy Technology Data Exchange (ETDEWEB)

    Bronfenbrenner, J.C.; Foster, E.P.

    1985-11-26

    A process is disclosed for stabilizing the viscosity of coal derived materials such as an SRC product by adding up to 5.0% by weight of a light volatile phenolic viscosity repressor. The viscosity will remain stabilized for a period of time of up to 4 months.

  4. Stability of dental implants in grafted bone in the anterior maxilla: longitudinal study.

    LENUS (Irish Health Repository)

    Al-Khaldi, Nasser

    2010-06-06

    We aimed to assess the stability over time of dental implants placed in grafted bone in the maxilla using resonance frequency analysis, and to compare the stability of implants placed in grafted and non-grafted bone. Data were collected from 23 patients (15 test and 8 controls) in whom 64 implants (Brånemark system, Nobel Biocare, Göteborg, Sweden) were placed in accordance with the two-stage surgical protocol. In the test group 36 fixtures were placed in grafted bone, and in the control group 28 fixtures were placed in non-grafted bone. Resonance frequency analysis was used to assess the test sites at implant placement and abutment connection. The mean (SD) implant stability quotient (ISQ) for test sites at the time of implant placement was 61.91 (6.68), indicating excellent primary stability, and was 63.53 (5.76) at abutment connection. ISQ values at abutment connection were similar for test and control sites. Implants placed in grafted bone compared favourably with those in non-grafted bone, and showed excellent stability.

  5. A study of cortisol reactivity and recovery among young adolescents: Heterogeneity and longitudinal stability and change.

    Science.gov (United States)

    Ji, Juye; Negriff, Sonya; Kim, Hansung; Susman, Elizabeth J

    2016-04-01

    The dominance of reactivity-based theories of the cortisol response and lack of attention to cortisol recovery makes it difficult to compile an integrated theory of the stress response. This report examined a reactivity and recovery model of the cortisol response using variable-centered and person-centered approaches. Age and sex differences and heterogeneity in the pattern of cortisol response were examined. Participants were 135 healthy young adolescents participating in a three-wave longitudinal study of puberty and psychological development. At each wave, five saliva-cortisol samples were collected prior to and following a modified Trier Social Stressor Test for Children. Linear, quadratic, and piece-wise models of latent growth curve analyses and latent class analyses were conducted. Age differences in cortisol reactivity and recovery were found at wave 1 and sex differences in cortisol reactivity emerged at wave 3. Meaningful heterogeneity in the pattern of cortisol response was found cross-sectionally and longitudinally. The implications of heterogeneity in the cortisol response during early adolescence for developmental science are discussed.

  6. Longitudinal/Lateral Stability Analysis of Vehicle Motion in the Nonlinear Region

    Directory of Open Access Journals (Sweden)

    Keji Chen

    2016-01-01

    Full Text Available We focus on the study of motion stability of vehicle nonlinear dynamics. The dynamic model combining with Burckhardt tire model is firstly derived. By phase portrait method, the vehicle stability differences of three cases, front wheels steering/four-wheel steering case, front/rear/four-wheel braking case, and high/low road friction case, are characterized. With the Jacobian matrix, the stable equilibrium point is found and stable areas are calculated out. Similarly, the stability boundaries corresponding to different working conditions are also captured. With vehicle braking or accelerating in the steering process, the relationship between front/rear wheel slippage and the stable area is examined. Comparing with current literatures, the research method and its results present the novelty and provide a guideline for new vehicle controller design.

  7. The characteristic clinical symptoms of C-4 radiculopathy caused by ossification of the posterior longitudinal ligament.

    Science.gov (United States)

    Katsumi, Keiichi; Yamazaki, Akiyoshi; Watanabe, Kei; Hirano, Toru; Ohashi, Masayuki; Endo, Naoto

    2014-05-01

    Cervical radiculopathy of the C2-4 spinal nerves is a rare condition and is poorly documented in terms of clinical symptoms, hindering its detection during initial patient screening based on imaging diagnostics. The authors describe in detail the clinical symptoms and successful surgical treatment of a patient diagnosed with isolated C-4 radiculopathy. This 41-year-old man suffered from sleep disturbance because of pain behind the right ear, along the right clavicle, and at the back of his neck on the right side. The Jackson and Spurling tests were positive, with pain radiating to the area behind the patient's ear. Unlike in cases of radiculopathy involving the C5-8 spinal nerves, no loss of upper-extremity motor function was seen. Magnetic resonance imaging showed foraminal stenosis at the C3-4 level on the right side, and multiplanar reconstruction CT revealed a beak-type ossification of the posterior longitudinal ligament in the foraminal region at the same level. In the absence of intracranial lesions or spinal cord compressive lesions, the positive Jackson and Spurling tests and the C3-4 foraminal stenosis were indicative of isolated C-4 radiculopathy. Microscopic foraminotomy was performed at the C3-4 vertebral level and the ossified lesion was resected. The patient's symptoms completely resolved immediately after surgery. To the authors' knowledge, this report is the first to describe the symptomatic features of isolated C-4 radiculopathy, in a case in which the diagnosis has been confirmed by both radiological findings and surgical outcome. Based on this case study, the authors conclude that the characteristic symptoms of C-4 radiculopathy are the presence of pain behind the ear and in the clavicular region in the absence of upper-limb involvement.

  8. Stability and Change in Educational and Occupational Aspirations: Longitudinal Analyses from Preadolescence to Young Adulthood.

    Science.gov (United States)

    Howell, Frank M.; Frese, Wolfgang

    Using two panel studies which collectively covered the preadolescent-to-young adulthood period in the life cycle, the study focused on the issues of level of aspiration formation, stability, and race-sex subgroup invariance. The panel studies collected data from youths from (1) rural areas with towns of 2,500 or less and urban areas with cities of…

  9. Stability characteristics of jets in linearly-stratified, rotating fluids

    Science.gov (United States)

    Chen, Rui-Rong; Boyer, Don L.; Tao, Lijun

    A series of laboratory experiments are conducted concerning an azimuthal jet of a linearly stratified rotating fluid in a cylindrical geometry. The jet is characterized by vertical and horizontal shear and the question of the stability of the flow is considered experimentally. The jet is driven by a source-sink method characterized by a volume flow rate of strength Q. BecauseQ has no direct geophysical significance a combined external set of dimensionless parameters is introduced. These include the Rossby, Richardson and Ekman numbers, the jet aspect ratio and two geometrical parameters. A RossbyRo against RichardsonRi number flow regime diagram is presented which shows that the wave mode of the instability generally decreases with increasingRo andRi, for fixedRi andRo, respectively. In accordance with Killworth's (1980) linear stability analysis, the wave mode for smallRi (Ri ⪉ 15) depends principally onRi with the instability being largely a baroclinic one. For largerRi(Ri ⪉ 100), again as predicted by Killworth's theory, the wave mode depends primarily onRo, the instability being a barotropic one. The regime diagram can be used to estimate the wave-length of jet instabilities in the atmosphere and oceans. These estimates suggest that the wave-lengths decrease with increasing jet velocity, decreasing jet width (equivalent to increasing horizontal shear) and increasing vertical shear, other parameters being fixed. An azimuthal topography aligned along the jet has the tendency to stabilize the jet in the sense that the amplitude of the instability is shown to be dramatically smaller in the presence of the topography, other parameters being fixed. The topography also tends to increase the wave-length of the instability. A scaling analysis is advanced, and supporting experimental data presented, relating the external and internal parameters utilized.

  10. Change and stability in childhood clique membership, isolation from cliques, and associated child characteristics

    NARCIS (Netherlands)

    Witvliet, M.; Lier, van P.A.C.; Cuijpers, P.; Koot, H.M.

    2010-01-01

    This study explored the role of clique membership and clique isolation in children’s psychosocial adjustment. We identified change and stability in early elementary school clique membership and investigated behavioral characteristics related to this change and stability. Participants were first-grad

  11. Longitudinal Stability and Growth in Literacy and Numeracy in Australian School Students.

    Science.gov (United States)

    Grasby, Katrina L; Coventry, William L

    2016-09-01

    We explored the genetic and environmental influence on both stability and growth in literacy and numeracy in 1927 Australian twin pairs from Grade 3 to Grade 9. Participants were tested on reading, spelling, grammar and punctuation, writing, and numeracy. In each domain, performance across time was highly correlated and this stability in performance was primary due to genes. Key findings on growth showed that reading followed a compensatory growth pattern that was largely due to genetic effects, while variation in growth in the other literacy domains was predominantly due to environmental influences. Genes and the shared environment influenced growth in numeracy for girls, while for boys it was influenced by the shared and unique environment. These results suggest that individual differences in growth of reading are primarily due to a genetically influenced developmental delay in the acquisition of necessary skills, while environmental influences, perhaps including different schools or teachers, are more important for the other domains.

  12. Interpretation bias and anxiety in childhood: stability, specificity and longitudinal associations

    OpenAIRE

    Creswell, Cathy; O'Connor, Thomas G

    2011-01-01

    Background: Biases in the interpretation of ambiguous material are central to cognitive models of anxiety; however, understanding of the association between interpretation and anxiety in childhood is limited. To address this, a prospective investigation of the stability and specificity of anxious cognitions and anxiety and the relationship between these factors was conducted. Method: Sixty-five children (10–11 years) from a community sample completed measures of self-reported anxiety, depress...

  13. Thermodynamic stability and flexibility characteristics of antibody fragment complexes.

    Science.gov (United States)

    Li, Tong; Verma, Deeptak; Tracka, Malgorzata B; Casas-Finet, Jose; Livesay, Dennis R; Jacobs, Donald J

    2014-01-01

    Free energy landscapes, backbone flexibility and residue-residue couplings for being co-rigid or co-flexible are calculated from the minimal Distance Constraint Model (mDCM) on an exploratory dataset consisting of VL, scFv and Fab antibody fragments. Experimental heat capacity curves are reproduced markedly well, and an analysis of quantitative stability/flexibility relationships (QSFR) is applied to a representative VL domain and several complexes in the scFv and Fab forms. Global flexibility in the denatured ensemble typically decreases in the larger complexes due to domain-domain interfaces. Slight decreases in global flexibility also occur in the native state of the larger fragments, but with a concurrent large increase in correlated flexibility. Typically, a VL fragment has more co-rigid residue pairs when isolated compared to the scFv and Fab forms, where correlated flexibility appears upon complex formation. This context dependence on residue- residue couplings in the VL domain across length scales of a complex is consistent with the evolutionary hypothesis of antibody maturation. In comparing two scFv mutants with similar thermodynamic stability, local and long-ranged changes in backbone flexibility are observed. In the case of anti-p24 HIV-1 Fab, a variety of QSFR metrics were found to be atypical, which includes comparatively greater co-flexibility in the VH domain and less co-flexibility in the VL domain. Interestingly, this fragment is the only example of a polyspecific antibody in our dataset. Finally, the mDCM method is extended to cases where thermodynamic data is incomplete, enabling high throughput QSFR studies on large numbers of antibody fragments and their complexes.

  14. Cognitive Performance in Older Adults with Stable Heart Failure: Longitudinal Evidence for Stability and Improvement

    Science.gov (United States)

    Alosco, Michael L.; Garcia, Sarah; Spitznagel, Mary Beth; van Dulmen, Manfred; Cohen, Ronald; Sweet, Lawrence H.; Josephson, Richard; Hughes, Joel; Rosneck, Jim; Gunstad, John

    2013-01-01

    Cognitive impairment is prevalent in heart failure (HF), though substantial variability in the pattern of cognitive impairment is found across studies. To clarify the nature of cognitive impairment in HF, we examined longitudinal trajectories across multiple domains of cognition in HF patients using latent growth class modeling. 115 HF patients completed a neuropsychological battery at baseline, 3-months and 12-months. Participants also completed the Beck Depression Inventory-II (BDI-II). Latent class growth analyses revealed a three-class model for attention/executive function, four-class model for memory, and a three-class model for language. The slope for attention/executive function and language remained stable, while improvements were noted in memory performance. Education and BDI-II significantly predicted the intercept for attention/executive function and language abilities. The BDI-II also predicted baseline memory. The current findings suggest that multiple performance-based classes of neuropsychological test performance exist within cognitive domains, though case-controlled prospective studies with extended follow-ups are needed to fully elucidate changes and predictors of cognitive function in HF. PMID:23906182

  15. Effect of the Various Impedances on Longitudinal Beam Stability in the CERN SPS

    CERN Document Server

    Lasheen, Alexandre; Repond, Joël; Shaposhnikova, Elena

    2016-01-01

    The High Luminosity (HL)-LHC project at CERN aims at a luminosity increase by a factor ten and one of the necessary ingredients is doubling the bunch intensity to 2.4x10¹¹ ppb for beams with 25 ns bunch spacing. Many improvements are already foreseen in the frame of the LHC Injector Upgrade (LIU) project, but probably this intensity would still not be reachable in the SPS due to longitudinal instabilities. Recently a lot of effort went into finding the impedance sources of the instabilities. Particle simulations based on the latest SPS impedance model are now able to reproduce the measured instability thresholds and were used to determine the most critical impedance sources by removing them one by one from the model. It was found that impedance of vacuum flanges and of the already damped 630 MHz HOM of the main RF system gave for 72 bunches the comparable intensity thresholds. Possible intensity gains are defined for realistic impedance modifications and for various beam configurations (number of bunches, l...

  16. Longitudinal Stability of Genetic and Environmental Influences on Irritability: From Childhood to Young Adulthood.

    Science.gov (United States)

    Roberson-Nay, Roxann; Leibenluft, Ellen; Brotman, Melissa A; Myers, John; Larsson, Henrik; Lichtenstein, Paul; Kendler, Kenneth S

    2015-07-01

    Little is known about genetic influences on juvenile irritability and whether such influences are developmentally stable and/or dynamic. This study examined the temporal pattern of genetic and environmental effects on irritability using data from a prospective, four-wave longitudinal twin study. Parents and their twin children (N=2,620 children) from the Swedish Twin Study of Child and Adolescent Development reported on the children's irritability, defined using a previously identified scale from the Child Behavior Checklist. Genetic effects differed across the sexes, with males exhibiting increasing heritability from early childhood through young adulthood and females exhibiting decreasing heritability. Genetic innovation was also more prominent in males than in females, with new genetic risk factors affecting irritability in early and late adolescence for males. Shared environment was not a primary influence on irritability for males or females. Unique, nonshared environmental factors suggested strong effects early for males followed by an attenuating influence, whereas unique environmental factors were relatively stable for females. Genetic effects on irritability are developmentally dynamic from middle childhood through young adulthood, with males and females displaying differing patterns. As males age, genetic influences on irritability increase while nonshared environmental influences weaken. Genetic contributions are quite strong in females early in life but decline in importance with age. In girls, nonshared environmental influences are fairly stable throughout development.

  17. Personality traits, interpersonal identity, and relationship stability: longitudinal linkages in late adolescence and young adulthood.

    Science.gov (United States)

    Klimstra, Theo A; Luyckx, Koen; Branje, Susan; Teppers, Eveline; Goossens, Luc; Meeus, Wim H J

    2013-11-01

    Adolescence and young adulthood are characterized by important changes in personality, changes toward a more stable identity, and the establishment of intimate relationships. We examined the role of personality traits in establishing intimate relationships, the interplay between personality traits and interpersonal identity processes during these relationships, and the role of interpersonal identity processes and personality traits in the dissolution thereof. For this purpose, we used longitudinal data on 424 female college students (mean age at T1 = 18.6 years; Sample 1) and 390 late adolescents drawn from a community sample (56.7% female; mean age at T1 = 19.7 years; Sample 2). Especially highly extraverted individuals were likely to become involved in a relationship. Neuroticism was associated negatively, and Agreeableness and Conscientiousness were associated positively with a stronger sense of interpersonal identity within intimate relationships. Finally, the importance of interpersonal identity processes was underscored by the fact that these processes, and not so much personality traits, predicted relational breakups. Overall, the present study provides important insights into the role of personality and identity in the initiation, maintenance, and dissolution of intimate relationships in late adolescence and young adulthood.

  18. Stability characteristics of hyper-concentration flow in open channel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The flow instability is related to many engineering problems and belongs to a wide-ranging research field. When the problem on the transition from the laminar to the turbulence caused by the instability of the laminar is studied,the "neutral line" and the critical Reynolds number are always taken as the criterion to judge whether a certain kind of flow is stable,whose corresponding flow medium is the clear water,that is,the single-phase Newtonian fluid. And it is not studied in the traditional in-stability theory that the hyper-concentration flow widely exists in rivers. This shortage can be covered by this research. Study shows that the instability of non-Newtonian fluid such as hyper-concentration fluid,compared with Newtonian fluid such as clear water,is influenced by not only Reynolds number,the ratio of the inertia force and the viscous force,but also many other factors such as the sediment concentration,the concentration distribution,the grain size,the volu-metric weight of the sediment and so on,which make the mechanical principle even more complex. So the results of the research can supply the scientific basis for the explanations of "slurrying river",the turbulence intensity of the flow carrying sediment and the variance of the turbulence structure.

  19. Stability characteristics of hyper-concentration flow in open channel

    Institute of Scientific and Technical Information of China (English)

    XU HaiJue; BAI YuChuan

    2008-01-01

    The flow instability is related to many engineering problems and belongs to a wide-rankling research field. When the problem on the transition from the laminar to the turbulence caused by the instability of the laminar is studied, the "neutral line" and the critical Reynolds number are always taken as the criterion to judge whether a certain kind of flow is stable, whose corresponding flow medium is the clear water, that is, the single-phase Newtonian fluid. And it is not studied in the traditional in-stability theory that the hyper-concentration flow widely exists in rivers. This shortage can be covered by this research. Study shows that the instability of non-Newtonian fluid such as hyper-concentration fluid, compared with Newtonian fluid such as clear water, is influenced by not only Reynolds number, the ratio of the inertia force and the viscous force, but also many other factors such as the sediment concentration, the concentration distribution, the grain size, the volu-metric weight of the sediment and so on, which make the mechanical principle even more complex. So the results of the research can supply the scientific basis for the explanations of "slurrying river", the turbulence intensity of the flow carrying sediment and the variance of the turbulence structure.

  20. Effects of excitation area of longitudinal transducer on the flexural vibration characteristics of a rectangular plate in stripe mode.

    Science.gov (United States)

    He, Xiping; Yao, Jing; Zhang, Haidao; Liu, Doudou; Li, Jiaxing

    2015-04-01

    The flexural vibration characteristics of a rectangular plate in stripe mode, driven at its center by a different longitudinal vibration ultrasonic transducer (LVUT) with different excitation area are investigated. The variation in the nodal lines and corresponding resonant frequency of the rectangular plate under different excitation area are calculated by using finite element method (FEM). The results show that the resonant frequency increases with the excitation area of the LVUT increasing, and the nodal lines bend obviously when the radius r of excitation area is greater than a certain value. The experimental tests are carried out by the aid of Polytec PSV-400 Scanning laser Vibrometer, and the results agree well those of numerically calculated. It indicates that the larger excitation area of longitudinal transducer may affect the ultrasonic field radiated by the rectangular plate.

  1. The applicability of Lyapunov characteristic numbers in the study of the stability of satellite orbits

    Science.gov (United States)

    Broucke, R.

    1982-01-01

    It is pointed out that the Lyapunov Characteristic Numbers constitute a new tool for determining stability of trajectories of dynamical systems, or, even more generally, of solutions of systems of ordinary differential equations. In contrast with the characteristic exponents, which apply only to periodic solutions, the Lyapunov Characteristic Numbers apply to arbitrary nonperiodic solutions as well. A description is presented of the numerical experiments which have been made in order to investigate the practical value of the Lyapunov Characteristic Number and the Kolmogorov Entropy for the purpose of estimating the stability of trajectories and/or numerical integration methods in celestial mechanics. It is found that the Lyapunov Characteristic Numbers are extremely useful for the classification of the solutions of nonintegrable dynamical systems, especially in order to distinguish between quasi-periodic and chaotic solutions. However, the Lyapunov Characteristics Numbers do not appear to be useful for the purpose of evaluating numerical integration methods.

  2. The applicability of Lyapunov characteristic numbers in the study of the stability of satellite orbits

    Science.gov (United States)

    Broucke, R.

    1982-01-01

    It is pointed out that the Lyapunov Characteristic Numbers constitute a new tool for determining stability of trajectories of dynamical systems, or, even more generally, of solutions of systems of ordinary differential equations. In contrast with the characteristic exponents, which apply only to periodic solutions, the Lyapunov Characteristic Numbers apply to arbitrary nonperiodic solutions as well. A description is presented of the numerical experiments which have been made in order to investigate the practical value of the Lyapunov Characteristic Number and the Kolmogorov Entropy for the purpose of estimating the stability of trajectories and/or numerical integration methods in celestial mechanics. It is found that the Lyapunov Characteristic Numbers are extremely useful for the classification of the solutions of nonintegrable dynamical systems, especially in order to distinguish between quasi-periodic and chaotic solutions. However, the Lyapunov Characteristics Numbers do not appear to be useful for the purpose of evaluating numerical integration methods.

  3. Technical Note: Spot characteristic stability for proton pencil beam scanning.

    Science.gov (United States)

    Chen, Chin-Cheng; Chang, Chang; Moyers, Michael F; Gao, Mingcheng; Mah, Dennis

    2016-02-01

    The spot characteristics for proton pencil beam scanning (PBS) were measured and analyzed over a 16 month period, which included one major site configuration update and six cyclotron interventions. The results provide a reference to establish the quality assurance (QA) frequency and tolerance for proton pencil beam scanning. A simple treatment plan was generated to produce an asymmetric 9-spot pattern distributed throughout a field of 16 × 18 cm for each of 18 proton energies (100.0-226.0 MeV). The delivered fluence distribution in air was measured using a phosphor screen based CCD camera at three planes perpendicular to the beam line axis (x-ray imaging isocenter and up/down stream 15.0 cm). The measured fluence distributions for each energy were analyzed using in-house programs which calculated the spot sizes and positional deviations of the Gaussian shaped spots. Compared to the spot characteristic data installed into the treatment planning system, the 16-month averaged deviations of the measured spot sizes at the isocenter plane were 2.30% and 1.38% in the IEC gantry x and y directions, respectively. The maximum deviation was 12.87% while the minimum deviation was 0.003%, both at the upstream plane. After the collinearity of the proton and x-ray imaging system isocenters was optimized, the positional deviations of the spots were all within 1.5 mm for all three planes. During the site configuration update, spot positions were found to deviate by 6 mm until the tuning parameters file was properly restored. For this beam delivery system, it is recommended to perform a spot size and position check at least monthly and any time after a database update or cyclotron intervention occurs. A spot size deviation tolerance of <15% can be easily met with this delivery system. Deviations of spot positions were <2 mm at any plane up/down stream 15 cm from the isocenter.

  4. Placebo effect characteristics observed in a single, international, longitudinal study in Huntington's disease.

    NARCIS (Netherlands)

    Cubo, E.; Gonzalez, M.; Puerto, I. del; Yebenes, J.G. de; Arconada, O.F.; Gabriel y Galan, J.M.; Kremer, H.P.H.; Warrenburg, B.P.C. van de

    2012-01-01

    BACKGROUND: Classically, clinical trials are based on the placebo-control design. Our aim was to analyze the placebo effect in Huntington's disease. METHODS: Placebo data were obtained from an international, longitudinal, placebo-controlled trial for Huntington's disease (European Huntington's Disea

  5. Placebo effect characteristics observed in a single, international, longitudinal study in Huntington's disease.

    NARCIS (Netherlands)

    Cubo, E.; Gonzalez, M.; Puerto, I. del; Yebenes, J.G. de; Arconada, O.F.; Gabriel y Galan, J.M.; Kremer, H.P.H.; Warrenburg, B.P.C. van de

    2012-01-01

    BACKGROUND: Classically, clinical trials are based on the placebo-control design. Our aim was to analyze the placebo effect in Huntington's disease. METHODS: Placebo data were obtained from an international, longitudinal, placebo-controlled trial for Huntington's disease (European Huntington's

  6. Stability and Heat Transfer Characteristics of Condensing Films

    Science.gov (United States)

    Hermanson, J. C.; Pedersen, P. C.; Allen, J. S.; Shear, M. A.; Chen, Z. Q.; Alexandrou, A. N.

    2002-11-01

    The overall objective of this research is to investigate the fundamental physics of film condensation in reduced gravity. The condensation of vapor on a cool surface is important in many engineering problems,including spacecraft thermal control and also the behavior of condensate films that may form on the interior surfaces of spacecraft. To examine the effects of body force on condensing films, two different geometries have been tested in the laboratory: (1) a stabilizing gravitational body force (+1g, or condensing surface facing 'upwards') and (2) de-stabilizing gravitational body force (-1g, or 'downwards'). For each geometry, different fluid configurations are employed to help isolate the fluid mechanical and thermal mechanisms operative in condensing films. The fluid configurations are (a) a condensing film, and (b) a non-condensing film with film growth by mass addition by through the plate surface. Condensation experiments are conducted in a test cell containing a cooled copper or brass plate with an exposed diameter of 12.7 cm. The metal surface is polished to allow for double-pass shadowgraph imaging, and the test surface is instrumented with imbedded heat transfer gauges and thermocouples. Representative shadowgraph images of a condensing, unstable (-1g) n-pentane film are shown. The interfacial disturbances associated with the de-stabilizing body force leading to droplet formation and break-off can be clearly seen. The heat transfer coefficient associated with the condensing film is shown. The heat transfer coefficient is seen to initially decrease, consistent with the increased thermal resistance due to layer growth. For sufficiently long time, a steady value of heat transfer is observed, accompanied by continuous droplet formation and break-off. The non-condensing cell consists of a stack of thin stainless steel disks 10 cm in diameter mounted in a brass enclosure. The disks are perforated with a regular pattern of 361 holes each 0.25 mm in diameter

  7. An Investigation of Two-Propeller Tilt Wing V/STOL Aircraft Flight Characteristics

    Science.gov (United States)

    1992-01-01

    aerodynamic input files or using manual input data. The output provides static aircraft longitudinal parameters for determining performance...wing aircraft so configured, the NASA Ames computer code TWANG is used for simulation of aircraft longitudinal stability and performance characteristics

  8. Technical Note: Spot characteristic stability for proton pencil beam scanning

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chin-Cheng, E-mail: chen.ccc@gmail.com; Chang, Chang; Mah, Dennis [ProCure Treatment Center, Somerset, New Jersey 08873 (United States); Moyers, Michael F. [ProCure Treatment Center, Somerset, New Jersey 08873 and Shanghai Proton and Heavy Ion Center, Shanghai 201321 (China); Gao, Mingcheng [CDH Proton Center, Warrenville, Illinois 60555 (United States)

    2016-02-15

    Purpose: The spot characteristics for proton pencil beam scanning (PBS) were measured and analyzed over a 16 month period, which included one major site configuration update and six cyclotron interventions. The results provide a reference to establish the quality assurance (QA) frequency and tolerance for proton pencil beam scanning. Methods: A simple treatment plan was generated to produce an asymmetric 9-spot pattern distributed throughout a field of 16 × 18 cm for each of 18 proton energies (100.0–226.0 MeV). The delivered fluence distribution in air was measured using a phosphor screen based CCD camera at three planes perpendicular to the beam line axis (x-ray imaging isocenter and up/down stream 15.0 cm). The measured fluence distributions for each energy were analyzed using in-house programs which calculated the spot sizes and positional deviations of the Gaussian shaped spots. Results: Compared to the spot characteristic data installed into the treatment planning system, the 16-month averaged deviations of the measured spot sizes at the isocenter plane were 2.30% and 1.38% in the IEC gantry x and y directions, respectively. The maximum deviation was 12.87% while the minimum deviation was 0.003%, both at the upstream plane. After the collinearity of the proton and x-ray imaging system isocenters was optimized, the positional deviations of the spots were all within 1.5 mm for all three planes. During the site configuration update, spot positions were found to deviate by 6 mm until the tuning parameters file was properly restored. Conclusions: For this beam delivery system, it is recommended to perform a spot size and position check at least monthly and any time after a database update or cyclotron intervention occurs. A spot size deviation tolerance of <15% can be easily met with this delivery system. Deviations of spot positions were <2 mm at any plane up/down stream 15 cm from the isocenter.

  9. Dynamic characteristics and seismic stability of expanded polystyrene geofoam embankments

    Science.gov (United States)

    Amini, Zahra A.

    Expanded Polystyrene (EPS) geofoam has become a preferred material in various construction applications due to its light weight. Application of EPS accelerates the projects particularly on soft soils. The focus of this research is on the application of the EPS in embankments and its behavior mainly under harmonic vibration. The goal of this study was to investigate dynamic characteristics of freestanding vertical EPS geofoam embankment and address potential seismic issues that result from the distinguished dynamic behavior of such systems due to the layered and discrete block structure. A series of experimental studies on EPS 19 and a commercially available adhesive was conducted. Two-dimensional numerical analyses were performed to replicate the response of EPS geofoam embankment to horizontal and vertical harmonic motions. The results of the analyses have shown that for some acceleration amplitude levels interlayer sliding is expected to occur in EPS geofoam embankments almost immediately after the start of the base excitation; however, as a highly efficient energy dissipation mechanism sliding ceases rapidly. Shear keys and adhesive may be used to prevent interlayer sliding if they cover the proper extent of area of the embankment. EPS blocks placed in the corners of the embankment and at the edges of the segment prohibited from sliding may experience high stress concentrations. The embankment may show horizontal sway and rocking once sliding is prevented.

  10. Externalizing Behaviors in Toddlerhood: A Longitudinal Study on the Role of Child and Parental Characteristics

    NARCIS (Netherlands)

    van Aken, A.A.A.M.

    2008-01-01

    According to recent theories, both person characteristics and environmental characteristics have to be taken into account in order to understand individual development. In line with these theories, the present thesis focused on the ways in which child characteristics and parental characteristics int

  11. Longitudinal stability and predictive utility of the visual P3 response in adults with externalizing psychopathology.

    Science.gov (United States)

    Yoon, Henry H; Malone, Stephen M; Iacono, William G

    2015-12-01

    We determined whether time-domain P3 amplitude and time-frequency principal component (TF-PC) reductions could serve as stable and predictive developmental endophenotypes of externalizing psychopathology. Participants from the Minnesota Twin Family Study were assessed at age 17 and again at age 29 for lifetime externalizing (EXT) disorders. Comparisons of P3 amplitude and TF-PCs at delta and theta frequencies were made between EXT and unaffected comparison subjects. P3 amplitude and all five extracted TF-PCs were significantly reduced in those presenting lifetime EXT disorders at both ages 17 and 29 and showed substantial 12-year rank-order stability. P3 amplitude and delta TF-PCs measured at age 17 also predicted subsequent development of EXT by age 29, with every 1-microvolt decrease in age 17 amplitude associated with an approximately 5% increase in risk for an EXT diagnosis by age 29. Overall, results from this study further confirm that these P3-derived brain measures maintain their potential as putative EXT endophenotypes through the third decade of life.

  12. Longitudinal stability of temperamental exuberance and social-emotional outcomes in early childhood.

    Science.gov (United States)

    Degnan, Kathryn A; Hane, Amie Ashley; Henderson, Heather A; Moas, Olga Lydia; Reeb-Sutherland, Bethany C; Fox, Nathan A

    2011-05-01

    The goals of the current study were to investigate the stability of temperamental exuberance across infancy and toddlerhood and to examine the associations between exuberance and social-emotional outcomes in early childhood. The sample consisted of 291 4-month-olds followed at 9, 24, and 36 months and again at 5 years of age. Behavioral measures of exuberance were collected at 9, 24, and 36 months. At 36 months, frontal electroencephalogram (EEG) asymmetry was assessed. At 5 years, maternal reports of temperament and behavior problems were collected, as were observational measures of social behavior during an interaction with an unfamiliar peer in the laboratory. Latent profile analysis revealed a high, stable exuberance profile that was associated with greater ratings of 5-year externalizing behavior and surgency, as well as observed disruptive behavior and social competence with unfamiliar peers. These associations were particularly true for children who displayed left frontal EEG asymmetry. Multiple factors supported an approach bias for exuberant temperament but did not differentiate between adaptive and maladaptive social-emotional outcomes at 5 years of age.

  13. Power Effects on the Longitudinal Characteristics of Single-Engine Propeller-Driven Aircraft

    Science.gov (United States)

    1983-02-01

    Operations and Airwoithiness Division STATUTORY AND STATE AUTHORITIES AND INDUSTRY Trans-Australia Airlines, Library Qantas Airways Limited SEC of Victoria...CONTENTS Page No. NOTATION 1. INTRODUCTIONI 2. LONGITUDINAL FLYING QUALITIES 2 3. METHOD OF ANALYSIS 4 Ř. SMAILL ANGLE ASSUMPTION 10 5. LISCUSSION 0...development of computational methods for the analysis of fluid dynamic problems of increasing complexity, the establishment of morc rigorous estimation

  14. Effect of winglets on a first-generation jet transport wing. 6: Stability characteristics for a full-span model at subsonic speeds. [conducted in Langley 8 foot transonic pressure tunnel

    Science.gov (United States)

    Flechner, S. G.

    1979-01-01

    A wind tunnel investigation to identify changes in stability and control characteristics of a model KC-135A due to the addition of winglets is presented. Static longitudinal and lateral-directional aerodynamic characteristics were determined for the model with and without winglets. Variations in the aerodynamic characteristics at various Mach numbers, angles of attack, and angles of slidslip are discussed. The effect of the winglets on the drag and lift coefficients are evaluated and the low speed and high speed characteristics of the model are reported.

  15. Change and stability in work-family conflict and mothers' and fathers' mental health: Longitudinal evidence from an Australian cohort.

    Science.gov (United States)

    Cooklin, A R; Dinh, H; Strazdins, L; Westrupp, E; Leach, L S; Nicholson, J M

    2016-04-01

    Work-family conflict (WFC) occurs when work or family demands are 'mutually incompatible', with detrimental effects on mental health. This study contributes to the sparse longitudinal research, addressing the following questions: Is WFC a stable or transient feature of family life for mothers and fathers? What happens to mental health if WFC increases, reduces or persists? What work and family characteristics predict WFC transitions and to what extent are they gendered? Secondary analyses of 5 waves of data (child ages 4-5 to 12-13 years) from employed mothers (n = 2693) and fathers (n = 3460) participating in the Longitudinal Study of Australian Children were conducted. WFC transitions, across four two-year intervals (Waves 1-2, 2-3, 3-4, and 4-5) were classified as never, conscript, exit or chronic. Significant proportions of parents experienced change in WFC, between 12 and 16% of mothers and fathers for each transition 'type'. Parents who remained in chronic WFC reported the poorest mental health (adjusted multiple regression analyses), followed by those who conscripted into WFC. When WFC was relieved (exit), both mothers' and fathers' mental health improved significantly. Predictors of conscript and chronic WFC were somewhat distinct for mothers and fathers (adjusted logit regressions). Poor job quality, a skilled occupation and having more children differentiated chronic fathers' from those who exited WFC. For mothers, work factors only (skilled occupation; work hours; job insecurity) predicted chronic WFC. Findings reflect the persistent, gendered nature of work and care shaped by workplaces, but also offer tailored opportunities to redress WFC for mothers and fathers. We contribute novel evidence that mental health is directly influenced by the WFC interface, both positively and negatively, highlighting WFC as a key social determinant of health.

  16. Self Q-switched characteristic based on single longitudinal DBR erbium-doped fiber laser with narrow linewidth pulse output

    Science.gov (United States)

    Lyu, Chengang; Zhang, Shuai; Zhang, Xugeng; Gao, Jiale; Jie, Jin

    2017-09-01

    The self Q-switched characteristic of the single longitudinal-mode distributed Bragg reflector (DBR) erbium-doped fiber laser (EDFL) with narrow linewidth pulse output is demonstrated without any extra saturable absorber or electro-optic and acoustic-optic modulator, and it is provided with a simpler structure and lower cost. The proposed pulse laser operates at approximately 1550.33 nm with a 20 dB bandwidth of 0.56 nm and signal-to-noise ratio of about 55 dB. By increasing the 980 nm pump power from 80-330 mW, the repetition rate of the output pulse increases from 73.53-147.1 kHz while the pulse width decreases from 1.4-0.2 µs, which shows the feature of the narrow linewidth ideally. The maximum pulse energy of 0.379 nJ and peak power of 1897.2 µW are generated with a repetition rate and pulse width of 147.1 kHz and 0.2 µs, respectively. The result shows that the self Q-switched pulse of the DBR EDFL is obviously dependent on the applied pump power and possesses the characteristic of the single longitudinal mode and the narrow linewidth, offering potential utilization in industrial processing and scientific research.

  17. Multidimensional performance characteristics and standard of performance in talented youth field hockey players : A longitudinal study

    NARCIS (Netherlands)

    Elferink-Gemser, Marije T.; Visscher, Chris; Lemmink, Koen A. P. M.; Mulder, Theo

    2007-01-01

    To identify performance characteristics that could help predict future elite field hockey players, we measured the anthropometric, physiological, technical, tactical, and psychological characteristics of 30 elite and 35 sub-elite youth players at the end of three consecutive seasons. The mean age of

  18. Invariance Property of the Stability Test with respect to the Characteristic Impedance

    Directory of Open Access Journals (Sweden)

    Amr A. Ibrahim

    2012-01-01

    Full Text Available Stability of electrical amplifiers is of crucial importance. Among the popular stability tests is the μ-test which has many advantages over other tests like the K-Δ test. However, the value of μ parameter is dependent on the input/output terminal characteristic impedance used and this raises the concern that the predictions of the test are dependent on the choice of . This paper proves that the conclusions of the μ-test regarding stability/instability remain invariant with . This proof is necessary for gaining confidence in the results of the μ-test and should benefit circuit designers. Similar proofs should be extended to all other stability tests for additional insights into their validity under different circuit termination.

  19. Stabilization

    Directory of Open Access Journals (Sweden)

    Muhammad H. Al-Malack

    2016-07-01

    Full Text Available Fuel oil flyash (FFA produced in power and water desalination plants firing crude oils in the Kingdom of Saudi Arabia is being disposed in landfills, which increases the burden on the environment, therefore, FFA utilization must be encouraged. In the current research, the effect of adding FFA on the engineering properties of two indigenous soils, namely sand and marl, was investigated. FFA was added at concentrations of 5%, 10% and 15% to both soils with and without the addition of Portland cement. Mixtures of the stabilized soils were thoroughly evaluated using compaction, California Bearing Ratio (CBR, unconfined compressive strength (USC and durability tests. Results of these tests indicated that stabilized sand mixtures could not attain the ACI strength requirements. However, marl was found to satisfy the ACI strength requirement when only 5% of FFA was added together with 5% of cement. When the FFA was increased to 10% and 15%, the mixture’s strength was found to decrease to values below the ACI requirements. Results of the Toxicity Characteristics Leaching Procedure (TCLP, which was performed on samples that passed the ACI requirements, indicated that FFA must be cautiously used in soil stabilization.

  20. A preliminary study of longitudinal differences in local dynamic stability between recently concussed and healthy athletes during single and dual-task gait.

    Science.gov (United States)

    Fino, Peter C

    2016-06-14

    Concussed individuals commonly exhibit locomotor deficits during dual-task gait that can last substantially longer than clinical signs and symptoms. Previous studies have examined traditional stability measures, but nonlinear stability may offer further information about the health of the motor control system post-concussion. For up to one year post-concussion, this study longitudinally examined the local dynamic stability of five concussed athletes and four matched healthy controls during single- and dual-task gait. Local dynamic stability (LDS) was estimated using short-term, finite-time maximum Lyapunov exponents calculated from tri-axial accelerometers placed on the trunk and head. No main effects of group or task were found for LDS or stride time variability, but significant group*task interactions were apparent for trunk stability and stride time variability. Concussed individuals exhibited decreased trunk LDS and increased stride time variability during dual-task walking compared to matched controls despite similar single-task stability and variability. These preliminary results reinforce previous reports that concussions persistently affect dual-task processes even when single-tasks may be unaffected. Furthermore, the decreased local dynamic stability during dual-task gait indicates the concussed group attenuated local disturbances less than their healthy teammates. The decreased dynamic stability during dual-task activities was present after the athletes were cleared for competition and may be a contributing factor in the higher rates of musculoskeletal injuries in athletes post-concussion.

  1. Effect of winglets on a first-generation jet transport wing. 5: Stability characteristics of a full-span wing with a generalized fuselage at high subsonic speeds

    Science.gov (United States)

    Jacobs, P. F.

    1978-01-01

    The effects of winglets on the static aerodynamic stability characteristics of a KC-135A jet transport model at high subsonic speeds are presented. The investigation was conducted in the Langley 8 foot transonic pressure tunnel using 0.035-scale wing panels mounted on a generalized research fuselage. Data were taken over a Mach number range from 0.50 to 0.95 at angles of attack ranging from -12 deg to 20 deg and sideslip angles of 0 deg, 5 deg, and -5 deg. The model was tested at two Reynolds number ranges to achieve a wide angle of attack range and to determine the effect of Reynolds number on stability. Results indicate that adding the winglets to the basic wing configuration produces small increases in both lateral and longitudinal aerodynamic stability and that the model stability increases slightly with Reynolds number. The winglets do increase the wing bending moments slightly, but the buffet onset characteristics of the model are not affected by the winglets.

  2. Adolescent Bariatric Surgery Program Characteristics: The Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Study Experience

    Science.gov (United States)

    Michalsky, M.P.; Inge, T.H.; Teich, S.; Eneli, I.; Miller, R.; Brandt, M.L.; Helmrath, M.; Harmon, C.M.; Zeller, M.H.; Jenkins, T.M.; Courcoulas, A.; Buncher, C.R.

    2013-01-01

    Background The number of adolescents undergoing weight loss surgery (WLS) has increased in response to the increasing prevalence of severe childhood obesity. Adolescents undergoing WLS require unique support, which may differ from adult programs. The aim of this study was to describe institutional and programmatic characteristics of centers participating in Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS), a prospective study investigating safety and efficacy of adolescent WLS. Methods Data were obtained from the Teen-LABS database and site survey completed by Teen-LABS investigators. The survey queried (1) institutional characteristics, (2) multidisciplinary team composition, (3) clinical program characteristics, and (4) clinical research infrastructure. Results All centers had extensive multidisciplinary involvement in the assessment, preoperative education and post-operative management of adolescents undergoing WLS. Eligibility criteria, pre-operative clinical and diagnostic evaluations were similar between programs. All programs have well developed clinical research infrastructure, use adolescent-specific educational resources, and maintain specialty equipment, including high weight capacity diagnostic imaging equipment. Conclusions The composition of clinical team and institutional resources are consistent with current clinical practice guidelines. These characteristics, coupled with dedicated research staff, have facilitated enrollment of 242 participants into Teen-LABS. PMID:24491361

  3. Adolescent bariatric surgery program characteristics: the Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study experience.

    Science.gov (United States)

    Michalsky, Marc P; Inge, Thomas H; Teich, Steven; Eneli, Ihuoma; Miller, Rosemary; Brandt, Mary L; Helmrath, Michael; Harmon, Carroll M; Zeller, Meg H; Jenkins, Todd M; Courcoulas, Anita; Buncher, Ralph C

    2014-02-01

    The number of adolescents undergoing weight loss surgery (WLS) has increased in response to the increasing prevalence of severe childhood obesity. Adolescents undergoing WLS require unique support, which may differ from adult programs. The aim of this study was to describe institutional and programmatic characteristics of centers participating in Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS), a prospective study investigating safety and efficacy of adolescent WLS. Data were obtained from the Teen-LABS database, and site survey completed by Teen-LABS investigators. The survey queried (1) institutional characteristics, (2) multidisciplinary team composition, (3) clinical program characteristics, and (4) clinical research infrastructure. All centers had extensive multidisciplinary involvement in the assessment, pre-operative education, and post-operative management of adolescents undergoing WLS. Eligibility criteria and pre-operative clinical and diagnostic evaluations were similar between programs. All programs have well-developed clinical research infrastructure, use adolescent-specific educational resources, and maintain specialty equipment, including high weight capacity diagnostic imaging equipment. The composition of clinical team and institutional resources is consistent with current clinical practice guidelines. These characteristics, coupled with dedicated research staff, have facilitated enrollment of 242 participants into Teen-LABS. © 2013 Published by Elsevier Inc.

  4. Asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) longitudinal profiling study

    OpenAIRE

    Silkoff, P E; I. Strambu; Laviolette, M.; Singh, D.; FitzGerald, J M; Lam, S.; Kelsen, S.; Eich, A.; Ludwig-Sengpiel, A.; hupp, G. C.; Backer, V.; Porsbjerg, C; Girodet, P. O.; Berger, P; Leigh, R.

    2015-01-01

    Background Asthma is a heterogeneous disease and development of novel therapeutics requires an understanding of pathophysiologic phenotypes. The purpose of the ADEPT study was to correlate clinical features and biomarkers with molecular characteristics, by profiling asthma (NCT01274507). This report presents for the first time the study design, and characteristics of the recruited subjects. Methods Patients with a range of asthma severity and healthy non-atopic controls were enrolled. The ast...

  5. Asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) longitudinal profiling study

    DEFF Research Database (Denmark)

    Silkoff, P E; Strambu, I; Laviolette, M

    2015-01-01

    BACKGROUND: Asthma is a heterogeneous disease and development of novel therapeutics requires an understanding of pathophysiologic phenotypes. The purpose of the ADEPT study was to correlate clinical features and biomarkers with molecular characteristics, by profiling asthma (NCT01274507). This re......BACKGROUND: Asthma is a heterogeneous disease and development of novel therapeutics requires an understanding of pathophysiologic phenotypes. The purpose of the ADEPT study was to correlate clinical features and biomarkers with molecular characteristics, by profiling asthma (NCT01274507...

  6. Rheological Characteristics of Weak Rock Mass and Effects on the Long-Term Stability of Slopes

    Science.gov (United States)

    Yang, Tianhong; Xu, Tao; Liu, Hongyuan; Zhang, Chunming; Wang, Shanyong; Rui, Yongqin; Shen, Li

    2014-11-01

    The creep deformation behavior of the northern slope of an open-pit mine is introduced. Direct shear creep tests are then conducted for the samples taken from the northern slope to study the rheological characteristics of the rock mass. The experimental results are analyzed afterwards using an empirical method to develop a rheological model for the rock mass. The proposed rheological model is finally applied to understand the creep behavior of the northern slope, predict the long-term stability, and guide appropriate measures to be taken at suitable times to increase the factor of safety to ensure stability. Through this study, a failure criterion is proposed to predict the long-term stability of the slope based on the rheological characteristics of the rock mass and a critical deformation rate is adopted to determine when appropriate measures should be taken to ensure slope stability. The method has been successfully applied for stability analysis and engineering management of the toppling and slippage of the northern slope of the open-pit mine. This success in application indicates that it is theoretically accurate, practically feasible, and highly cost-effective.

  7. Temporal stability of epigenetic markers: sequence characteristics and predictors of short-term DNA methylation variations.

    Directory of Open Access Journals (Sweden)

    Hyang-Min Byun

    Full Text Available BACKGROUND: DNA methylation is an epigenetic mechanism that has been increasingly investigated in observational human studies, particularly on blood leukocyte DNA. Characterizing the degree and determinants of DNA methylation stability can provide critical information for the design and conduction of human epigenetic studies. METHODS: We measured DNA methylation in 12 gene-promoter regions (APC, p16, p53, RASSF1A, CDH13, eNOS, ET-1, IFNγ, IL-6, TNFα, iNOS, and hTERT and 2 of non-long terminal repeat elements, i.e., L1 and Alu in blood samples obtained from 63 healthy individuals at baseline (Day 1 and after three days (Day 4. DNA methylation was measured by bisulfite-PCR-Pyrosequencing. We calculated intraclass correlation coefficients (ICCs to measure the within-individual stability of DNA methylation between Day 1 and 4, subtracted of pyrosequencing error and adjusted for multiple covariates. RESULTS: Methylation markers showed different temporal behaviors ranging from high (IL-6, ICC = 0.89 to low stability (APC, ICC = 0.08 between Day 1 and 4. Multiple sequence and marker characteristics were associated with the degree of variation. Density of CpG dinucleotides nearby the sequence analyzed (measured as CpG(o/e or G+C content within ±200 bp was positively associated with DNA methylation stability. The 3' proximity to repeat elements and range of DNA methylation on Day 1 were also positively associated with methylation stability. An inverted U-shaped correlation was observed between mean DNA methylation on Day 1 and stability. CONCLUSIONS: The degree of short-term DNA methylation stability is marker-dependent and associated with sequence characteristics and methylation levels.

  8. Stability Emulsion and Sensory Characteristics Low Fat Mayonnaise Using Kefir as Emulsifier Replacer

    Directory of Open Access Journals (Sweden)

    Herly Evanuarini

    2017-03-01

    Full Text Available Mayonnaise is a kind of semi solid oil in water (o/w emulsion which containing pasteurized egg yolk as an emulsifier. The consumers have demanded that the use of egg yolk be reduced. Kefir was used to develop a low fat mayonnaise as emulsifier replacer to egg yolk. The objective of this research was to observe the emulsion stability, sensory characteristics of low fat mayonnaise prepare during kefir as emulsifier replacer. The research method was using experimental design. The result showed that formulation of low fat mayonnaise by using Rice bran oil 40%, kefir 20% produces the optimal low fat mayonnaise in emulsion stability and accepted by the panelist.

  9. Supersonic longitudinal aerodynamic characteristics of two space shuttle orbiter configurations. [conducted in the Langley Unitary Plan wind tunnel

    Science.gov (United States)

    Ellison, J. C.

    1977-01-01

    An investigation was conducted to determine the supersonic longitudinal aerodynamic characteristics of 0.015 scale models of the Rockwell International 089B and 139B space shuttle orbiter configurations and the 139B orbiter with a modifier forebody. The models each had a 45 deg swept delta wing that was blended into the body with an 81 deg swept fillet to form a double delta planform. The vertical tail had a split rudder deflected 27.5 deg on each side to form a speed brake. Tests were conducted at Mach numbers of 2.5, 3.9, and 4.6 at a Reynolds number, based on the body length of the 089B model, of 4,150,000. Angles of attack varied from -4 deg to 44 deg at 0 deg sideslip.

  10. Characteristics of Double Exponentially Tapered Slot Antenna (DETSA) Conformed in the Longitudinal Direction Around a Cylindrical Structure

    Science.gov (United States)

    Ponchak, George E.; Jordan, Jennifer L.; Chevalier, Christine T.

    2006-01-01

    The characteristics of a double exponentially tapered slot antenna (DETSA) as a function of the radius that the DETSA is conformed to in the longitudinal direction is presented. It is shown through measurements and simulations that the radiation pattern of the conformed antenna rotates in the direction through which the antenna is curved, and that diffraction affects the radiation pattern if the radius of curvature is too small or the frequency too high. The gain of the antenna degrades by only 1 dB if the radius of curvature is large and more than 2 dB for smaller radii. The main effect due to curving the antenna is an increased cross-polarization in the E-plane.

  11. Effect of tail size reductions on longitudinal aerodynamic characteristics of a three surface F-15 model with nonaxisymmetric nozzles

    Science.gov (United States)

    Frassinelli, Mark C.; Carson, George T., Jr.

    1990-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of horizontal and vertical tail size reductions on the longitudinal aerodynamic characteristics of a modified F-15 model with canards and 2-D convergent-divergent nozzles. Quantifying the drag decrease at low angles of attack produced by tail size reductions was the primary focus. The model was tested at Mach numbers of 0.40, 0.90, and 1.20 over an angle of attack of -2 degree to 10 degree. The nozzle exhaust flow was simulated using high pressure air at nozzle pressure ratios varying from 1.0 (jet off) to 7.5. Data were obtained on the baseline configuration with and without tails as well as with reduced horizontal and/or vertical tail sizes that were 75, 50, and 25 percent of the baseline tail areas.

  12. Effects of Rainfall Characteristics on the Stability of Tropical Residual Soil Slope

    Directory of Open Access Journals (Sweden)

    Rahardjo Harianto

    2016-01-01

    Full Text Available Global climate change has a significant impact on rainfall characteristics, sea water level and groundwater table. Changes in rainfall characteristics may affect stability of slopes and have severe impacts on sustainable urban living. Information on the intensity, frequency and duration of rainfall is often required by geotechnical engineers for performing slope stability analyses. Many seepage analyses are commonly performed using the most extreme rainfall possible which is uneconomical in designing a slope repair or slope failure preventive measure. In this study, the historical rainfall data were analyzed and investigated to understand the characteristics of rainfall in Singapore. The frequency distribution method was used to estimate future rainfall characteristics in Singapore. New intensity-duration-frequency (IDF curves for rainfall in Singapore were developed for six different durations (10, 20, 30 min and 1, 2 and 24 h and six frequencies (2, 5, 10, 25, 50 and 100 years. The new IDF curves were used in the seepage and slope stability analyses to determine the variation of factor of safety of residual soil slopes under different rainfall intensities in Singapore.

  13. Borderline personality disorder symptoms and newlyweds' observed communication, partner characteristics, and longitudinal marital outcomes.

    Science.gov (United States)

    Lavner, Justin A; Lamkin, Joanna; Miller, Joshua D

    2015-11-01

    Given borderline personality disorder's (BPD) relation with interpersonal dysfunction, there is substantial interest in understanding BPD's effect on marriage. The current study used data from a community sample of 172 newlywed couples to examine spouses' BPD symptoms in relation to their observed communication, partner BPD symptoms, 4-year marital quality trajectories, and 10-year divorce rates. BPD symptoms were correlated cross-sectionally with more negative skills during observational problem-solving and social support tasks, and spouses reporting more BPD symptoms were married to partners reporting more BPD symptoms. Longitudinally, hierarchical linear modeling of newlyweds' 4-year marital trajectories indicated that BPD symptoms predicted the intercept of marital quality for spouses and their partners, reflecting lower levels of marital satisfaction and higher levels of marital problems. BPD symptoms did not predict 10-year divorce rates. These findings highlight the chronic relationship impairment associated with BPD symptoms, indicate that distress begins early in marriage, and suggest that partners with higher levels of BPD symptoms remain in more troubled marriages. (c) 2015 APA, all rights reserved).

  14. The importance of job characteristics in determining medical care-seeking in the Dutch working population, a longitudinal survey study

    Directory of Open Access Journals (Sweden)

    Steenbeek Romy

    2012-08-01

    Full Text Available Abstract Background The working population is ageing, which will increase the number of workers with chronic health complaints, and, as a consequence, the number of workers seeking health care. It is very important to understand factors that influence medical care-seeking in order to control the costs. I will investigate which work characteristics independently attribute to later care-seeking in order to find possibilities to prevent unnecessary or inefficient care-seeking. Methods Data were collected in a longitudinal two-wave study (n = 2305 workers. The outcome measures were visits (yes/no and frequency to a general practitioner (GP, a physical therapist, a medical specialist and/or a mental health professional. Multivariate regression analyses were carried out separately for men and women for workers with health complaints. Results In the Dutch working population, personal, health, and work characteristics, but not sickness absence, were associated with later care-seeking. Work characteristics independently attributed to medical care-seeking but only for men and only for the frequency of visits to the GP. Women experience more health complaints and seek health care more often than men. For women, experiencing a work handicap (health complaints that impede work performance was the only work characteristic associated with more care-seeking (GP. For men, work characteristics that led to less care-seeking were social support by colleagues (GP frequency, high levels of decision latitude (GP frequency and high levels of social support by the supervisor (medical specialist. Other work characteristics led to more care-seeking: high levels of engagement (GP, full time work (GP frequency and experiencing a work handicap (physical therapist. Conclusions We can conclude that personal and health characteristics are most important when explaining medical care-seeking in the Dutch working population. Work characteristics independently attributed to

  15. The importance of job characteristics in determining medical care-seeking in the Dutch working population, a longitudinal survey study.

    Science.gov (United States)

    Steenbeek, Romy

    2012-08-31

    The working population is ageing, which will increase the number of workers with chronic health complaints, and, as a consequence, the number of workers seeking health care. It is very important to understand factors that influence medical care-seeking in order to control the costs. I will investigate which work characteristics independently attribute to later care-seeking in order to find possibilities to prevent unnecessary or inefficient care-seeking. Data were collected in a longitudinal two-wave study (n = 2305 workers). The outcome measures were visits (yes/no and frequency) to a general practitioner (GP), a physical therapist, a medical specialist and/or a mental health professional. Multivariate regression analyses were carried out separately for men and women for workers with health complaints. In the Dutch working population, personal, health, and work characteristics, but not sickness absence, were associated with later care-seeking. Work characteristics independently attributed to medical care-seeking but only for men and only for the frequency of visits to the GP. Women experience more health complaints and seek health care more often than men. For women, experiencing a work handicap (health complaints that impede work performance) was the only work characteristic associated with more care-seeking (GP). For men, work characteristics that led to less care-seeking were social support by colleagues (GP frequency), high levels of decision latitude (GP frequency) and high levels of social support by the supervisor (medical specialist). Other work characteristics led to more care-seeking: high levels of engagement (GP), full time work (GP frequency) and experiencing a work handicap (physical therapist). We can conclude that personal and health characteristics are most important when explaining medical care-seeking in the Dutch working population. Work characteristics independently attributed to medical care-seeking but only for men and only for the

  16. Lifetime improvement and beam stabilization by longitudinal phase modulation at the DELTA electron storage ring; Lebensdauerverbesserung und Strahlstabilisierung durch longitudinale Phasenmodulation am Elektronenspreicherring DELTA

    Energy Technology Data Exchange (ETDEWEB)

    Fuersch, Jonathan

    2014-10-16

    In DELTA especially at high beam currents often the occurence of an instability of a longitudinal oscillation mode is observed. In the framework of the present thesis first with different procedure the cause of the longitudinal oscillation mode, which is especially strongly excited at high beam currents, is searched for. Thereby connections between the occurrence of this mode and parameters from the region of the storage-ring high-frequency system is observed. It is shown by comparison of different procedures, simulation calculations, and experimental pre-examinations, that especially by a phase modulation of the storage-ring high frequency an essential improvement of especially the longitudinal beam stability and the beam lifetime can be reached. For the durable and reliable improvement of these beam properties in the framework of the present thesis a system for the longitudinal phase modulation of the after-acceleration voltage in the cavity resonator of the DELTA storage ring is concipated, developed, constructed, taken in operation, and tested. Finally the results aimed hereby are presented and discussed.

  17. Thin-Section CT Characteristics and Longitudinal CT Follow-up of Chemotherapy Induced Interstitial Pneumonitis

    Science.gov (United States)

    Lee, Han Na; Kim, Mi Young; Koo, Hyun Jung; Kim, Sung-Soo; Yoon, Dok Hyun; Lee, Jae Cheol; Song, Jin Woo

    2016-01-01

    Abstract To describe the computed tomography (CT) features of chemotherapy-induced interstitial pneumonitis (CIIP) with longitudinal follow-up. The study was approved by the local ethics committee. One hundred consecutive patients with CIIP between May 2005 and March 2015 were retrospectively enrolled. The initial CT was reviewed by 2 independent chest radiologists and categorized into 1 of 4 CT patterns in accordance with the 2013 guidelines for idiopathic interstitial pneumonia: nonspecific interstitial pneumonia (NSIP), organizing pneumonia (OP), hypersensitivity pneumonitis (HP) mimicking desquamative interstitial pneumonitis, and diffuse alveolar damage (DAD). We assessed semiquantitative analysis on a 5% scale to assess the extent of parenchymal abnormalities (emphysema, reticulation, ground-glass opacity, consolidation, honeycombing cyst) and their distribution on initial (n = 100), subsequent (n = 87), and second follow-up CT (n = 48). Interval changes in extent on follow-up CT were compared using paired t test. The clinic-radiologic factors were compared between Group 1 (NSIP and OP patterns) and Group 2 (HP and DAD patterns) using χ2 and independent t tests. The most common pattern of CIIP on the initial CT was HP (51%), followed by NSIP (23%), OP (20%), and DAD (6%). Diffuse ground-glass opacity was the most common pulmonary abnormality. The predominant distribution was bilateral (99%) and symmetric (82%), with no craniocaudal (60%) or axial (79%) dominance. Subsequent and second follow-up CTs showed decreased extent of total pulmonary abnormalities (P CIIP, Group 2 CIIP was more likely to be caused by molecularly targeted drugs (P = 0.030), appeared earlier (P = 0.034), and underwent more complete resolution (P CIIP is appropriate and practical in interpreting radiological findings. PMID:26765442

  18. Autodyne characteristics of stabilized UHF-oscillators at a strong reflected signal

    Directory of Open Access Journals (Sweden)

    Noskov V. Ya.

    2011-11-01

    Full Text Available Calculations and examinations of phase, amplitude, frequency and amplitude-frequency characteristics are fulfilled for the autodyne system stabilized by the external high-Q cavity as well as spectral characteristics under condition of exact and non-exact cavity tuning and the variations of distance to reflector. The distinguished peculiarities of the autodyne response at the small and large reflected signal are described. Experimental research results are discussed fulfilled on an example of the hybrid-integrated oscillator on Gunn diode of 8-mm-range, which confirm qualitatively the theoretic results.

  19. Longitudinal Changes in Nursing Home Resident-Reported Quality of Life: The Role of Facility Characteristics.

    Science.gov (United States)

    Shippee, Tetyana P; Hong, Hwanhee; Henning-Smith, Carrie; Kane, Robert L

    2015-08-01

    Improving quality of nursing homes (NHs) is a major social priority, yet few studies examine the role of facility characteristics for residents' quality of life (QOL). This study goes beyond cross-sectional analyses by examining the predictors of NH residents' QOL on the facility level over time. We used three data sources, namely resident interviews using a multidimensional measure of QOL collected in all Medicaid-certified NHs in Minnesota (N = 369), resident clinical data from the minimum data set, and facility-level characteristics. We examined change in six QOL domains from 2007 to 2010, using random coefficient models. Eighty-one facilities improved across most domains and 85 facilities declined. Size, staffing levels (especially activities staff), and resident case mix are some of the most salient predictors of QOL over time, but predictors differ by facility performance status. Understanding the predictors of facility QOL over time can help identify facility characteristics most appropriate for targeting with policy and programmatic interventions. © The Author(s) 2014.

  20. Effects of pH on rheological characteristics and stability of petroleum coke water slurry

    Directory of Open Access Journals (Sweden)

    Fu-Yan Gao

    2016-10-01

    Full Text Available Abstract In this study, the effects of pH on slurrying properties of petroleum coke water slurry (PCWS were investigated. The slurrying concentration, rheological characteristics and stability of PCWS were studied with four different types of additives at pH varying from 5 to 11. The results showed that the slurrying concentration, rheological characteristics and stability of PCWS all increased at first and then decreased with increasing pH from 5 to 11, and a pH of around 9 was found to be the most favorable acid–alkali environment to all these three slurrying properties. It was also indicated that only in a moderate alkaline environment can the additives be active enough to react with particle surfaces sufficiently to obtain good slurrying concentration and form a stable three-dimensional network structure, which can support strong pseudoplastic characteristics and good stability. An acid environment was a very unfavorable factor to the slurrying properties of PCWS.

  1. 高超声速巡航飞行器纵向气动特性分析%Longitudinal Aerodynamic Characteristics Analysis of Hypersonic Cruise Vehicle

    Institute of Scientific and Technical Information of China (English)

    邢永刚; 唐硕

    2011-01-01

    The airframe integrated nature of the scramjet engine with airbreathing hypersonic cruise vehicle (HCV) results in a strong couplings between aerodynamics and propulsive system. The couplings have an effect on vehicle aerodynamic performance, stability and control. Aiming at the effects, the model of airframe integrated scramjet engine has been developed and aero-propulsion interface separated. Based on the forgoing work,longitudinal aerodynamic characteristics of HCV inlet open, scramjet engine powered and unpowered have been computed separately. Simulation reveals the couplings between aerodynamics and propulsive system and the effect on vehicle characteristics.%吸气式高超声速巡航飞行器机身/发动机一体化特性使得气动一推进系统之间存在强的耦合作用,这种耦合影响着飞行器气动性能、稳定性和控制.针对耦合对飞行器特性的影响,建立了机身一发动机一体化模型,并进行了气动-推进界面划分.在此基础上,分别计算了高超声速巡航飞行器在进气道打开,发动机不工作以及进气道打开,发动机工作两种状态下的纵向气动特性.仿真结果揭示了高超声速巡航飞行器气动一推进系统之间的耦合以及耦合作用对飞行器气动性能、稳定性的影响.

  2. Quality characteristics and stability of Moringa oleifera seed oil of Indian origin.

    Science.gov (United States)

    Ogunsina, Babatunde S; Indira, T N; Bhatnagar, A S; Radha, C; Debnath, S; Gopala Krishna, A G

    2014-03-01

    Cold pressed and hexane extracted moringa seed oils (CPMSO and HEMSO) were evaluated for their physico-chemical and stability characteristics. The iodine value, saponification value and unsaponifiable matter of CPMSO and HEMSO were found to be 67.8 and 68.5 g I2 / 100 g oil, 190.4 and 191.2 mg KOH / g oil and 0.59 and 0.65%, respectively. The total tocopherols of CPMSO and HEMSO were found to be 95.5 and 90.2 mg/Kg. The fatty acid composition of CPMSO and HEMSO showed oleic acid as the major fatty acid (78-79%). The oxidative, thermal and frying stabilities of the CPMSO were compared with commercial raw and refined groundnut oil (GNO and RGNO). The CPMSO was of adequate thermal stability and better oxidative stability as it showed 79% lesser peroxide formation than GNO. The frying stability of CPMSO was better as it showed lower increase in free fatty acid (28%), peroxide value (10 meq O2/Kg) and color (25%) than RGNO (48%, 22 meq O2/kg and 52%, respectively) after frying.

  3. Impact of aerobic stabilization on the characteristics of treatment sludge in the leather tanning industry.

    Science.gov (United States)

    Cokgor, Emine Ubay; Aydinli, Ebru; Tas, Didem Okutman; Zengin, Gulsum Emel; Orhon, Derin

    2014-01-01

    The efficiency of aerobic stabilization on the treatment sludge generated from the leather industry was investigated to meet the expected characteristics and conditions of sludge prior to landfill. The sludge types subjected to aerobic stabilization were chemical treatment sludge, biological excess sludge, and the mixture of both chemical and biological sludges. At the end of 23 days of stabilization, suspended solids, volatile suspended solids and total organic carbon removal efficiencies were determined as 17%, 19% and 23% for biological sludge 31%, 35% and 54% for chemical sludge, and 32%, 34% and 63% for the mixture of both chemical and biological sludges, respectively. Model simulations of the respirometric oxygen uptake rate measurements showed that the ratio of active biomass remained the same at the end of the stabilization for all the sludge samples. Although mixing the chemical and biological sludges resulted in a relatively effective organic carbon and solids removal, the level of stabilization achieved remained clearly below the required level of organic carbon content for landfill. These findings indicate the potential risk of setting numerical restrictions without referring to proper scientific support.

  4. Common mental disorders and sociodemographic characteristics: baseline findings of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    Science.gov (United States)

    Nunes, Maria A; Pinheiro, Andréa P; Bessel, Marina; Brunoni, André R; Kemp, Andrew H; Benseñor, Isabela M; Chor, Dora; Barreto, Sandhi; Schmidt, Maria I

    2016-01-01

    To assess the prevalence of common mental disorders (CMD) and the association of CMD with sociodemographic characteristics in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort. We analyzed data from the cross-sectional baseline assessment of the ELSA-Brasil, a cohort study of 15,105 civil servants from six Brazilian cities. The Clinical Interview Schedule-Revised (CIS-R) was used to investigate the presence of CMD, with a score ≥ 12 indicating a current CMD (last week). Specific diagnostic algorithms for each disorder were based on the ICD-10 diagnostic criteria. Prevalence ratios (PR) of the association between CMD and sociodemographic characteristics were estimated by Poisson regression. CMD (CIS-R score ≥ 12) was found in 26.8% (95% confidence intervals [95%CI] 26.1-27.5). The highest burden occurred among women (PR 1.9; 95%CI 1.8-2.0), the youngest (PR 1.7; 95%CI 1.5-1.9), non-white individuals, and those without a university degree. The most frequent diagnostic category was anxiety disorders (16.2%), followed by depressive episodes (4.2%). The burden of CMD was high, particularly among the more socially vulnerable groups. These findings highlight the need to strengthen public policies aimed to address health inequities related to mental disorders.

  5. Longitudinal MRI evaluation of intracranial development and vascular characteristics of breast cancer brain metastases in a mouse model.

    Directory of Open Access Journals (Sweden)

    Heling Zhou

    Full Text Available Longitudinal MRI was applied to monitor intracranial initiation and development of brain metastases and assess tumor vascular volume and permeability in a mouse model of breast cancer brain metastases. Using a 9.4T system, high resolution anatomic MRI and dynamic susceptibility contrast (DSC perfusion MRI were acquired at different time points after an intracardiac injection of brain-tropic breast cancer MDA-MB231BR-EGFP cells. Three weeks post injection, multifocal brain metastases were first observed with hyperintensity on T2-weighted images, but isointensity on T1-weighted post contrast images, indicating that blood-tumor-barrier (BTB at early stage of brain metastases was impermeable. Follow-up MRI revealed intracranial tumor growth and increased number of metastases that distributed throughout the whole brain. At the last scan on week 5, T1-weighted post contrast images detected BTB disruption in 160 (34% of a total of 464 brain metastases. Enhancement in some of the metastases was only seen in partial regions of the tumor, suggesting intratumoral heterogeneity of BTB disruption. DSC MRI measurements of relative cerebral blood volume (rCBV showed that rCBV of brain metastases was significantly lower (mean= 0.89±0.03 than that of contralateral normal brain (mean= 1.00±0.03; p<0.005. Intriguingly, longitudinal measurements revealed that rCBV of individual metastases at early stage was similar to, but became significantly lower than that of contralateral normal brain with tumor growth (p<0.05. The rCBV data were concordant with histological analysis of microvascular density (MVD. Moreover, comprehensive analysis suggested no significant correlation among tumor size, rCBV and BTB permeability. In conclusion, longitudinal MRI provides non-invasive in vivo assessments of spatial and temporal development of brain metastases and their vascular volume and permeability. The characteristic rCBV of brain metastases may have a diagnostic value.

  6. Error Estimate of the Ares I Vehicle Longitudinal Aerodynamic Characteristics Based on Turbulent Navier-Stokes Analysis

    Science.gov (United States)

    Abdol-Hamid, Khaled S.; Ghaffari, Farhad

    2011-01-01

    Numerical predictions of the longitudinal aerodynamic characteristics for the Ares I class of vehicles, along with the associated error estimate derived from an iterative convergence grid refinement, are presented. Computational results are based on the unstructured grid, Reynolds-averaged Navier-Stokes flow solver USM3D, with an assumption that the flow is fully turbulent over the entire vehicle. This effort was designed to complement the prior computational activities conducted over the past five years in support of the Ares I Project with the emphasis on the vehicle s last design cycle designated as the A106 configuration. Due to a lack of flight data for this particular design s outer mold line, the initial vehicle s aerodynamic predictions and the associated error estimates were first assessed and validated against the available experimental data at representative wind tunnel flow conditions pertinent to the ascent phase of the trajectory without including any propulsion effects. Subsequently, the established procedures were then applied to obtain the longitudinal aerodynamic predictions at the selected flight flow conditions. Sample computed results and the correlations with the experimental measurements are presented. In addition, the present analysis includes the relevant data to highlight the balance between the prediction accuracy against the grid size and, thus, the corresponding computer resource requirements for the computations at both wind tunnel and flight flow conditions. NOTE: Some details have been removed from selected plots and figures in compliance with the sensitive but unclassified (SBU) restrictions. However, the content still conveys the merits of the technical approach and the relevant results.

  7. The repeatability and characteristics of right ventricular longitudinal strain imaging by speckle-tracking echocardiography in healthy dogs.

    Science.gov (United States)

    Morita, T; Nakamura, K; Osuga, T; Yokoyama, N; Khoirun, N; Morishita, K; Sasaki, N; Ohta, H; Takiguchi, M

    2017-08-01

    To assess the repeatability and characteristics of echocardiographic indices of the right ventricular (RV) function derived from speckle-tracking echocardiography. Fourteen laboratory Beagles and 103 privately owned dogs without cardiac disease were involved in this study. Right ventricular longitudinal strain, strain rate, and a strain-related index for assessing RV dyssynchrony derived from speckle-tracking echocardiography were obtained by two different observers using five Beagles. Within-day, between-day, and interobserver coefficients of variation and the intraclass correlation coefficient of speckle-tracking echocardiography indices were determined. Both speckle-tracking echocardiography and conventional indices of RV function, including the peak velocity of systolic tricuspid annular motion, tricuspid annulus plane systolic excursion, fractional area change, and the Tei index, were obtained from 14 Beagles and 103 privately owned dogs. Relationships between echocardiographic indices and the body weight, heart rate, age, and sex were estimated by regression analysis. Speckle-tracking echocardiographic indices showed good within-day repeatability, between-day and interobserver repeatability were moderate to good. In large dogs, RV longitudinal strain, strain rate, and fractional area change were significantly decreased, while the index of RV dyssynchrony, systolic tricuspid annular motion, tricuspid annulus plane systolic excursion, and the Tei index were increased. All speckle-tracking and conventional echocardiographic indices were correlated with the body weight. The speckle-tracking echocardiography indices were highly repeatable and body weight affected speckle-tracking echocardiography indices in dogs. Further studies are needed to apply speckle-tracking echocardiography indices in dogs with cardiac disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. The transverse and longitudinal beam characteristics of the PHIN photo-injector at CERN

    CERN Document Server

    Mete, Ö; Dabrowski, A; Divall, M; Döbert, S; Egger, D; Elsener, K; Fedosseev, V; Lefèvre, T; Petrarca, M

    2010-01-01

    A new photo-injector, capable to deliver a long pulse train with a high charge per bunch for CTF3, has been designed and installed by a collaboration between LAL, CCLRC and CERN within the framework of the second Joint Research Activity PHIN of the European CARE program. The demonstration of the high charge and the stability along the pulse train are the important goals for CTF3 and the CLIC drive beam. The nominal beam for CTF3 has an average current of 3.5 A, a 1.5 GHz bunch repetation frequency and a pulse length of 1.27 μs (1908 bunches). The existing CTF3 injector consists of a thermionic gun and a subharmonic bunching system. The PHIN photo-injector is being tested in a dedicated test-stand at CERN to replace the existing CTF3 injector that is producing unwanted satellite bunches during the bunching process. A phase-coding scheme is planned to be implemented to the PHIN laser system providing the required beam temporal structure by CTF3. RF photo-injectors are high-brightness, low-emittance electron so...

  9. Longitudinal effects of menopausal hormone treatments on platelet characteristics and cell-derived microvesicles.

    Science.gov (United States)

    Miller, Virginia M; Lahr, Brian D; Bailey, Kent R; Heit, John A; Harman, S Mitchell; Jayachandran, Muthuvel

    2016-01-01

    Activated platelets serve as a catalyst for thrombin generation and a source of vasoactive and mitogenic factors affecting vascular remodeling. Oral menopausal hormone treatments (MHT) may carry greater thrombotic risk than transdermal products. This study compared effects of oral and transdermal MHT on platelet characteristics, platelet proteins, and platelet-derived microvesicles (MV) in recently menopausal women. Platelets and MV were prepared from blood of a subset of women (n = 117) enrolled in the Kronos Early Estrogen Prevention Study prior to and after 48 months of treatment with either oral conjugated equine estrogen (0.45 mg/day), transdermal 17β-estradiol (50 µg/day), each with intermittent progesterone (200 mg/day for 12 days a month), or placebo pills and patch. Platelet count and expression of platelet P-selectin and fibrinogen receptors were similar across groups. An aggregate measure of 4-year change in vasoactive and mitogenic factors in platelet lysate, by principle component analysis, indicated significantly lower values in both MHT groups compared to placebo. Increases in numbers of tissue factor positive and platelet-derived MV were significantly greater in the transdermal compared to placebo group. MHT was associated with significantly reduced platelet content of vasoactive and mitogenic factors representing a potential mechanism by which MHT may affect vascular remodeling. Various hormonal compositions and doses of MHT could differentially regulate nuclear transcription in bone marrow megakaryocytes and non-genomic pathways in circulating platelets thus determining numbers and characteristics of circulating MV. Thrombotic risk associated with oral MHT most likely involves liver-derived inflammatory/coagulation proteins rather than circulating platelets per se.

  10. Characteristics of premixed flames stabilized in an axisymmetric curved-wall jet burner with tip modification

    KAUST Repository

    Kim, Daejoong

    2009-11-10

    The stabilization characteristics of premixed flames in an axisymmetric curved-wall jet burner have been experimentally investigated. This burner utilized the Coanda effect on top of a burner tip. The initially spherical burner tip was modified to a flat tip and a concave tip in order to improve flame stabilization by providing enough space for flow recirculation above the burner tip region. The flow characteristics have been visualized using a schlieren technique. Small-scale turbulence structure has been observed mainly in the interaction jet region (located downstream of the recirculation region) for large jet velocity (Reynolds number >11,500). An appreciable amount of air entrainment was exhibited from the half-angle of the jet spread, approximately 20. The averaged planar laser-induced fluorescence images of the flames for this large velocity demonstrated that the strong signal of OH radicals, representing reaction zones, existed in the recirculation zone, while it was weak in the interaction jet region due to intermittency and local extinction by the generation of small scale turbulence. The OH radical signals strengthened again in the merged jet region (downstream of the interaction jet region). In extreme cases of Reynolds number over 19,000, a unique flame exhibiting OH radicals only in the recirculation zone was observed for the concave tip. The flame stabilization has been mapped by varying jet velocity and equivalence ratio, and the result showed that the stabilization characteristics were improved appreciably from the initial spherical tip design, especially for rich mixtures. The flow fields measured by a laser Doppler velocimetry confirmed the existence of recirculation zone and the expansion of the recirculation zones for the modified tips. The temperature profile measured by a coherent anti-Stokes Raman spectroscopy exhibited an intermittent nature, especially near the recirculation zone.

  11. Response and Dynamical Stability of Oscillators with Discontinuous or Steep First Derivative of Restoring Characteristic

    Directory of Open Access Journals (Sweden)

    Željko Božić

    2009-01-01

    Full Text Available Response and dynamical stability of oscillators with discontinuous or steep first derivative of restoring characteristic is considered in this paper. For that purpose, a simple single-degree-of-freedom system with piecewise-linear force-displacement relationship subjected to a harmonic force excitation is analysed by the method of piecing the exact solutions (MPES in the time domain and by the incremental harmonic balance method (IHBM in the frequency domain. The stability of the periodic solutions obtained in the frequency domain by IHBM is estimated by the Floquet-Lyapunov theorem. Obtained frequency response characteristic is very complex and includes multi-frequency response for a single frequency excitation, jump phenomenon, multi-valued and non-periodic solutions. Determining of frequency response characteristic in the time domain by MPES is exceptionally time consuming, particularly inside the frequency ranges of co-existence of multiple stable solutions. In the frequency domain, IHBM is very efficient and very well suited for obtaining wide range frequency response characteristics, parametric studies and bifurcation analysis. On the other hand, neglecting of very small harmonic terms (which in-significantly influence the r.m.s. values of the response and are very small in comparison to other terms of the spectrum can cause very large error in evaluation of the eigenvalues of the monodromy matrix, and so they can lead to incorrect prediction of the dynamical stability of the solution. Moreover, frequency ranges are detected inside which the procedure of evaluation of eigenvalues of the monodromy matrix does not converge with increasing the number of harmonics included in the supposed approximate solution.

  12. The reciprocal relationship between work characteristics and employee burnout and engagement: a longitudinal study of firefighters.

    Science.gov (United States)

    Ângelo, R P; Chambel, M J

    2015-04-01

    The paradigm of this study is positive occupational psychology, with the job demands-resources model as the research model and the Conservation of Resources theory as the general stress theory. The research design analyses the job demands-resources model's dynamic nature with normal and reversed causation effects between work characteristics and psychological well-being among Portuguese firefighters. In addition, we analyse a positive (engagement) dimension and a negative (burnout) dimension in the firefighters' well-being, because previously, studies have merely focused on the strain or stress of these professionals. The research questionnaire was distributed to a sample of 651 firefighters, and a two-wave full panel design was used. Cross-lagged panel analyses indicated that the causal direction of the relationship between organizational demands and burnout is reciprocal. Also, we found that the reciprocal model, including cross-lagged reciprocal relationships between organizational demands/supervisory support and burnout/engagement, respectively, is what fits the data best. Practical implications to develop organizational change programmes and suggestions for future research regarding the promotion of occupational health are discussed. Copyright © 2013 John Wiley & Sons, Ltd.

  13. Longitudinal heterogeneity of sediment characteristics during southwest monsoon season in hyper-eutrophic Krishnagiri reservoir, India.

    Science.gov (United States)

    Sudha, Velu; Ambujam, Neelakantapillai Kanniperumal

    2012-03-01

    Krishnagiri reservoir is a hyper-eutrophicated reservoir located in Krishnagiri district which is one of the drought-prone districts in Tamil Nadu, India. The reservoir water is being used for various purposes such as irrigation, drinking, fish rearing, livestock rearing, and recreation. Since there is no an evidence of investigation on bottom sediments in Krishnagiri reservoir, the present study was carried out during southwest monsoon season in 2008. This study examined the physical and chemical characteristics of the bottom sediments such as composition, redox potential, moisture content, organic carbon, organic matter, total phosphorus, and total iron at 15 locations in the reservoir. Phosphorus fractionation study was carried out to find out different fractions such as loosely adsorbed phosphorous, iron and aluminium-bound phosphorus, calcium-bound phosphorous, and organic phosphorous. Results indicated that there was spatial variation in the composition of sediments and low values of redox potential. The significant positive correlation exists between the organic carbon and organic phosphorus concentration. The lacustrine zone of the reservoir showed high accumulation of total phosphorus and total iron when compared to riverine and transition zones. This study concludes an allogenic origin of majority of inorganic phosphorus in the reservoir during the study period and this might have been derived from the catchment during the erosion process. The high concentration of surface sediment phosphorus clearly indicates a greater threat of eutrophication in Krishnagiri reservoir.

  14. A numerical investigation into the aerodynamic characteristics and aeroelastic stability of a footbridge

    Science.gov (United States)

    Taylor, I. J.; Vezza, M.

    2009-01-01

    The results of a numerical investigation into the aerodynamic characteristics and aeroelastic stability of a proposed footbridge across a highway in the north of England are presented. The longer than usual span, along with the unusual nature of the pedestrian barriers, indicated that the deck configuration was likely to be beyond the reliable limits of the British design code BD 49/01. The calculations were performed using the discrete vortex method, DIVEX, developed at the Universities of Glasgow and Strathclyde. DIVEX has been successfully validated on a wide range of problems, including the aeroelastic response of bridge deck sections. In particular, the investigation focussed on the effects of non-standard pedestrian barriers on the structural integrity of the bridge. The proposed deck configuration incorporated a barrier comprised of angled flat plates, and the bridge was found to be unstable at low wind speeds, with the plates having a strong turning effect on the flow at the leading edge of the deck. These effects are highlighted in both a static and dynamic analysis of the bridge deck, along with modifications to the design that aim to improve the aeroelastic stability of the deck. Proper orthogonal decomposition (POD) was also used to investigate the unsteady pressure field on the upper surface of the static bridge deck. The results of the flutter investigation and the POD analysis highlight the strong influence of the pedestrian barriers on the overall aerodynamic characteristics and aeroelastic stability of the bridge.

  15. Metastable Electrical Characteristics of Polycrystalline Thin-Film Photovoltaic Modules upon Exposure and Stabilization: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Deline, C. A.; del Cueto, J. A.; Albin, D. S.; Rummel, S. R.

    2011-09-01

    The significant features of a series of stabilization experiments conducted at the National Renewable Energy Laboratory (NREL) between May 2009 and the present are reported. These experiments evaluated a procedure to stabilize the measured performance of thin-film polycrystalline cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS) thin-film photovoltaic (PV) modules. The current-voltage (I-V) characteristics of CdTe and CIGS thin-film PV devices and modules exhibit transitory changes in electrical performance after thermal exposure in the dark and/or bias and light exposures. We present the results of our case studies of module performance versus exposure: light-soaked at 65 degrees C; exposed in the dark under forward bias at 65 degrees C; and, finally, longer-term outdoor exposure. We find that stabilization can be achieved to varying degrees using either light-soaking or dark bias methods and that the existing IEC 61646 light-soaking interval may be appropriate for CdTe and CIGS modules with one caveat: it is likely that at least three exposure intervals are required for stabilization.

  16. WISC-R Verbal and Performance IQ Discrepancy in an Unselected Cohort: Clinical Significance and Longitudinal Stability.

    Science.gov (United States)

    Moffitt, Terrie E.; Silva, P. A.

    1987-01-01

    Examined children whose Wechsler Intelligence Scale for Children-Revised (WISC-R) verbal and performance Intelligence Quotient discrepancies placed them beyond the 90th percentile. Longitudinal study showed 23 percent of the discrepant cases to be discrepant at two or more ages. Studied frequency of perinatal difficulties, early childhood…

  17. Selected psychological characteristics and health behaviors of aging marathon runners: a longitudinal study.

    Science.gov (United States)

    Morgan, W P; Costill, D L

    1996-05-01

    This report summarizes the health behaviors and psychological characteristics of fifteen male marathon runners who were first tested in 1969 (N = 8) and 1976 (N = 7). The participants in this study averaged 29 years of age at the outset, and the mean age at the time of follow-up was 50 years. These subjects were found to score in the normal range on all of the psychological variables, and they were characterized by the "iceberg" profile described earlier for elite athletes in various sports. This profile includes scores that fall below the population average on mood states such as tension, depression, anger, fatigue and confusion along with above average scores on vigor. Also, the psychological traits of these former runners have been remarkably stable across the past two decades, with the exception that a uniform decline has been observed for the neuroticism measure. Earlier research by Eysenck has shown that neuroticism decreases with age. These former marathon runners continue to be moderately active, and it is noteworthy that they first became involved as runners while in high school. All but one of the participants had attended college, and each had participated in competitive running while in college. Training for marathon competition took place following the college years. It is likely that much of the early success enjoyed by this group was governed to a substantial degree by heredity. This sample possessed an average aerobic power of 70 ml.kg-1.min-1 along with a unique somatotype when first tested, and these factors are known to have a substantial heritability component. The health behaviors studied in this group were uniformly positive. They were found to be physically active, and their physical self-esteem fell above that of other men in their age group. The subjects reported moderate use of alcohol, no insomnia, few physical problems and good overall mood. The sample of former marathon runners described in this report is unique in a number of respects

  18. Characteristics of stress distribution in floor strata and control of roadway stability under coal pillars

    Institute of Scientific and Technical Information of China (English)

    Tongqiang Xiao; Bai Jianbiao; Xu Lei; Zhang Xuebin

    2011-01-01

    Given the difficulties encountered in roadway support under coal pillars, we studied the characteristics of stress distribution and their effect on roadway stability, using theoretical analysis and numerical simulation. The results show that, under a coal pillar, vertical stress in a floor stratum increases while horizontal stress decreases. We conclude that the increased difference between vertical and horizontal stress is an important reason for deformation of the surrounding rock and failures of roadways under coal pillars. Based on this, we propose control technologies of the surrounding rock of a roadway under a coal pillar, such as high strength and high pre-stressed bolt support, cable reinforcement support,single hydraulic prop with beam support and reinforcement by grouting of the surrounding rock, which have been successfully applied in a stability control project of a roadway under a coal pillar.

  19. Thermal stability and structural characteristics of PTHF–Mmt organophile nanocomposite

    Directory of Open Access Journals (Sweden)

    Youcef Hattab

    2015-05-01

    The objective of this study is to use organophilized montmorillonites in the presence of monomer tetrahydrofuran to obtain polytétrahydrofuran montmorillonites (PTHF–Mmt of composites by polymerization in situ. The organophilisation of the Mmt is formed by active cationic surface. The obtained results show an increase in the distance inside the reticular in the diffractograms of X-rays (DRX and the appearance of absorption bands of the characteristics of polytétrahydrofuran on the spectra of infrared spectroscopy (IR, which indicate pre-polymerization of tetrahydrofuran in the galleries of clay and, therefore, the obtaining of a nanocomposite. We have also studied the thermal stability of the samples by differential analysis calorimetric (DSC analysis, and we can conclude that the nanocomposites are stabilized thermally by the presence of clay in the matrix.

  20. Change and stability in childhood clique membership, isolation from cliques, and associated child characteristics.

    Science.gov (United States)

    Witvliet, Miranda; van Lier, Pol A C; Cuijpers, Pim; Koot, Hans M

    2010-01-01

    This study explored the role of clique membership and clique isolation in children's psychosocial adjustment. We identified change and stability in early elementary school clique membership and investigated behavioral characteristics related to this change and stability. Participants were first-grade pupils (N = 300), followed over a 1-year period. Clique membership was identified through social network analysis. Differences between children with a stable versus changing clique membership status were tested using peer nominations and teacher ratings. Clique members were better adjusted than nonclique members. Externalizing behavior, less prosocial behavior, and low social preference preceded clique estrangement. Stable-isolates increased in externalizing behavior, whereas children who became part of a dyad or included in a clique showed a decrease in externalizing behavior.

  1. Stability characteristics of the open channel flow above the asymmetrical irregular sand ripples

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Sandy bed cannot keep its original smoothness as the flows pass. With the increase of the flow intensity, the bed forms will appear as sand ripples and dune in turn. Among these morphologies, the sand ripple scale is the smallest, which is generally symmetrical when it just appears, but as time goes on, the asymmetrical form gradually develops. Just because of this sand ripples asymmetry, it manifests the influence of the flow on the bed morphology and also the impact on the laminar flow dynamical process, especially the stability characteristics. The stability features of laminar flow on open channels with the asymmetrical sand ripples are discussed, and also the results on the symmetrical sand ripples are compared in detail.

  2. Characteristics of vertical stability of the body of hard hearing primary school children during physical education

    Directory of Open Access Journals (Sweden)

    Storozhik A.І.

    2013-06-01

    Full Text Available Studied the specific features of the motor areas of hearing children of primary school age - the vertical stability of their body. In pedagogical experiment involved 58 hearing children of primary school age and 52 healthy student. The analysis of the amplitude-frequency characteristics of the common center of gravity of the body. Revealed a statistically significant difference in the sagittal and frontal planes between the studied parameters of the surveyed population. The data obtained can be used for quantitative assessment of the vertical stability of the body younger students. The results of the experiment can serve as a basis for the development of technology aimed at the formation of the orthograde posture younger students this nosology.

  3. Node Disjoint Multipath Routing Considering Link and Node Stability protocol: A characteristic Evaluation

    CERN Document Server

    Upadhayaya, Shuchita

    2010-01-01

    Mobile Ad hoc Networks are highly dynamic networks. Quality of Service (QoS) routing in such networks is usually limited by the network breakage due to either node mobility or energy depletion of the mobile nodes. Also, to fulfill certain quality parameters, presence of multiple node-disjoint paths becomes essential. Such paths aid in the optimal traffic distribution and reliability in case of path breakages. Thus, to cater various challenges in QoS routing in Mobile Add hoc Networks, a Node Disjoint Multipath Routing Considering Link and Node Stability (NDMLNR) protocol has been proposed by the authors. The metric used to select the paths takes into account the stability of the nodes and the corresponding links. This paper studies various challenges in the QoS routing and presents the characteristic evaluation of NDMLNR w.r.t various existing protocols in this area.

  4. Association between children's exposure to a violent event and objectively and subjectively measured sleep characteristics: a pilot longitudinal study.

    Science.gov (United States)

    Spilsbury, James C; Babineau, Denise C; Frame, Jennifer; Juhas, Kimberly; Rork, Kristine

    2014-10-01

    Although sleep disturbances are commonly reported among children exposed to violence, objective evidence of such disturbances is rare. This longitudinal, home-based study assessed the effects of a known community- or family-violence incident on both actigraphy-derived and subjectively reported sleep outcomes of an ethnically mixed, urban sample of children aged 8-16 years. We hypothesized that increased event severity (child physical assault, witnessed homicide) would be associated with lower sleep duration and poorer sleep quality both at baseline and at 3-month follow-up. Covariate-adjusted analyses based on a generalized estimating equations approach showed that children physically assaulted during the event showed lower sleep duration and sleep efficiency and greater wake after sleep onset than those not physically assaulted. Physically assaulted children were more likely to have a later bedtime than non-assaulted children, but this difference decreased at 3 months. Children witnessing a homicide showed greater wake after sleep onset at baseline and reported greater sleep problems than those witnessing a non-homicide event, but these differences decreased at 3 months. They were also somewhat more likely to have greater nightly variation in sleep duration. Collectively, results suggest that violence exposure influences children's sleep, but that specific dimensions of sleep may exhibit different susceptibility to different characteristics of violence, especially over time.

  5. Effect of Longitudinal-External-Fins on Fluid Flow Characteristics for Wing-Shaped Tubes Bundle in Crossflow

    Directory of Open Access Journals (Sweden)

    Sayed Ahmed E. Sayed Ahmed

    2015-01-01

    Full Text Available A numerical study is conducted to clarify fluid-flow characteristics, pressure drop coefficient (Pdc, and the average skin friction coefficient (Cf,m for wing-shaped-tubes bundle with longitudinal fins at downstream side of the tube using the commercial CFD FLUENT software package. The air-side Rea ranges from 1800 to 9700. The tubes are employed with various fin heights (hf and fin thicknesses (δ such as 2 mm ≤ hf ≤ 12 mm and 1.5 mm ≤ δ ≤ 3.5 mm at the considered Rea range. Results indicate that ΔPa increases with Rea for all hf. Pdc decreases with Rea for all hf values for 1800 ≤ Rea ≤ 4200 and then increases for 4200 ≤ Rea ≤ 10000. Lowest values of ΔPa, Pdc, and pumping power (PP occurred at hf = 6 mm. Values of Pdc for hf = 6 mm are lower than those of NOF and hf = 2 mm by about 73 % and 32 %, respectively, at Rea = 4000. Cf,m decreases with Rea. δ has negligible effect on Cf,m. ΔPa increases for 1.5 mm ≤ δ ≤ 2.5 mm while ΔPa decreases with 2.5 mm < δ ≤ 3.5 mm for the considered Rea range except for Rea = 1850.

  6. Characteristics of Cervical Spine Trauma in Patients with Ankylosing Spondylitis and Ossification of the Posterior Longitudinal Ligament.

    Science.gov (United States)

    Lee, Chang Kyu; Yoon, Do Heum; Kim, Keung Nyun; Yi, Seong; Shin, Dong Ah; Kim, Byeongwoo; Lee, Nam; Ha, Yoon

    2016-12-01

    To compare the clinical characteristics of cervical spine trauma in patients with ankylosing spondylitis (AS) and cervical ossification of the posterior longitudinal ligament (OPLL) with those of a control group. A total of 124 patients with cervical spine trauma from January 2004 to December 2013 were reviewed. Fourteen patients were diagnosed with AS and 25 patients were diagnosed with OPLL; 85 patients were controls. C-spine plain radiography, computed tomography, and magnetic resonance imaging were obtained for evaluation of cervical spine trauma. The American Spinal Injury Association impairment scale and Subaxial Cervical Spine Injury Classification were used to evaluate the neurologic status of patients and the fracture mechanism. Patients with AS or OPLL had more spinal injuries associated with minor trauma than did the control group. All patients with AS had spinal fracture injuries after cervical spine trauma, but patients with OPLL mostly had spinal cord injuries without bony fractures. After cervical spine trauma, delayed diagnosis occurred in 3 patients with AS (21.4%) and 4 patients with OPLL (15.6%). Improvement from neurologic deficit after treatment showed better outcomes in patients with AS and OPLL than in controls (P = 0.106). Patients with AS or OPLL who had cervical spine trauma showed different characteristics and outcomes than control patients. Proper surgical treatment led to better outcomes in both patients with AS and patients with OPLL than in control patients. Moreover, it is important to thoroughly examine patients with AS or OPLL after cervical trauma so as not to delay diagnosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Characteristics of thermal hydraulic stability in a HYPER system with enhanced natural circulation potential

    Energy Technology Data Exchange (ETDEWEB)

    Tak, Nam Il; Park, Won S.; Han, Seok Jung

    1999-06-01

    Pb-Bi eutectic chosen as a coolant of HYPER is an excellent heat transfer medium but requires relatively large pumping power. Thus the mixed cooling concept to increase economy and safety is being considered for HYPER. In this cooling concept, a large fraction of total thermal power is carried by natural circulation. However, the mixed cooling concept has been considered for conceptual designs only an it has never been applied to real reactors. The purpose of the present study is to provide simple tools to analyze mixed flow and to examine fundamental stability characteristics of mixed flow. Conventional one-dimensional approaches using mass, momentum, and energy conservation are used to describe a forced circulating flow affected by a large buoyancy force. The results of simple analysis using preliminary design parameters of HYPER show that cooling by mixed flow is possible only when the total pressure loss of system is sufficiently low. The stability behavior of mixed flow in a simple rectangular loop has been studied using numerical solutions of the governing equations. As in the case of natural circulation, three types of flow regions, such as stable, neutrally stable, and unstable regions, were found. The stability map of mixed flow has been obtained using the results of calculations. Forced flow due to the pump is found to increase the stability of the loop, since the stable portion of the stability map is increased. However, the unstable region of the mixed flow does not completely disappear, even though the pump exists. (author). 37 refs., 4 tabs., 23 figs.

  8. Technique for Assessing the Stability and Controllability Characteristics of Naval Aircraft Systems Based on the Rational Combination of Modeling, Identification and Flight Experiments

    Directory of Open Access Journals (Sweden)

    S. V. Nikolaev

    2015-01-01

    Full Text Available The aim of this work is to improve test quality and reliability of modern naval aircraft for assessment of stability and controllability characteristics and test shortening. To achieve this goal it is necessary to develop an algorithmic, mathematical and methodological support of the flight trials and the mathematical modeling of controlled flight modes to determine the stability and controllability characteristics of the naval aircraft.The article analyses the problems related to determining the stability and controllability characteristics under flight tests, describes the technique to correct a mathematical model of aerodynamic characteristics and engine thrust forces of modern naval aircraft. It shows the importance of using algorithm to control the correctness of onboard measurements of flight parameters. The article presents new results of identification of the aircraft aerodynamic coefficients and proves that in identifying characteristics of the longitudinal control channel it is necessary to take into account the engine thrust forces. In the article the aerodynamic coefficients, obtained by identification methods, are compared with those in the original aerodynamic data Bank.An important and new component of the work described in the fourth part of the article, is a set of computer programmes, integrated into a common interface. The development of this software has greatly improved a processing technology of the flight experiment materials and identification of the aerodynamic characteristics of the aircraft.When applying the work results in the testing phase, the required characteristics of stability and controllability are determined by simulation, and identification provides the model refinement according to the flight data.The created technology of practical identification is used to verify and refine the mathematical models according to the flight experiment data. Thus, the result is a proven and refined model of the aircraft

  9. A Longitudinal Study of Predictors of Housing Stability, Housing Quality, and Mental Health Functioning Among Single Homeless Individuals Staying in Emergency Shelters.

    Science.gov (United States)

    Aubry, Tim; Duhoux, Arnaud; Klodawsky, Fran; Ecker, John; Hay, Elizabeth

    2016-09-01

    The current study examined risk and resilience factors at multiple levels that affect homeless individuals' ability to exit homelessness and achieve housing stability. It also examined the relationship between housing status, housing quality and mental health functioning. The methodology is a longitudinal study of single homeless individuals staying in emergency shelters in a medium-sized Canadian city who were followed for a 2 year period. Data were collected from participants at a baseline interview when they were homeless and at a 2-year follow-up. There were 329 participants interviewed at baseline and 197 (59.9%) participants interviewed at follow-up. Results from a structural equation modelling analysis found that having interpersonal and community resources were predictive of achieving housing stability. Specifically, having a larger social support network, access to subsidized housing, and greater income was related to achieving housing stability. On the other hand, having a substance use problem was a risk factor associated with a failure to achieving housing stability. Being female, feeling personally empowered, having housing that is perceived of being of higher quality were directly predictive of mental health functioning at follow-up. Findings are discussed in the context of previous research and their policy implications.

  10. Stability of electric characteristics of solar cells for continuous power supply

    Directory of Open Access Journals (Sweden)

    Stojanović Nebojša M.

    2015-01-01

    Full Text Available This paper investigates the output characteristics of photovoltaic solar cells working in hostile working conditions. Examined cells, produced by different innovative procedures, are available in the market. The goal was to investigate stability of electric characteristics of solar cells, which are used today in photovoltaic solar modules for charging rechargeable batteries which, coupled with batteries, supply various electronic systems such as radio repeaters on mountains tops, airplanes, mobile communication stations and other remote facilities. Charging of rechargeable batteries requires up to 25 % higher voltage compared to nominal output voltage of the battery. This paper presents results of research of solar cells, which also apply to cases in which continuous power supply is required. [Projekat Ministarstva nauke Republike Srbije, br. III 171007

  11. Characteristics of Bamboo Leaf Ash Stabilization on Lateritic Soil in Highway Construction

    Directory of Open Access Journals (Sweden)

    Akinwole A. Adetuberu

    2010-08-01

    Full Text Available This research was carried out to study the characteristics of bamboo leaf ash stabilization on lateritic soil in highway construction. Preliminary tests were performed on three samples, A, B, and C foridentification and classification purposes followed by the consistency limit tests. Geotechnical property tests (compaction, California bearing ratio (CBR, and triaxial were also performed on the samples, both at the stabilized and unstabilized states by adding 2, 4, 6, 8 and 10% bamboo leaf ash (BLA by weight of sample tothe soils. The results showed that the addition of BLA improved the strengths of the samples. Optimum moisture contents reduced to 20.20, 19.60 and 9.32% at 8, 4 and 6% BLA additions in samples A, B and Crespectively while MDD increased to 1400, 1676 and 1941 kg/m3 respectively at 8, 2 and 4% BLA additions in samples A, B, and C. The unsoaked CBR values of samples A and B increased from 5.44 to 38.21% and from 11.42 to 34.99% respectively. The shear strengths of samples A and B also increased from 181.31 to 199.00 kN/m2 and from 144.81 to 155.90 kN/m2 respectively. It was therefore concluded that bamboo leaf ash has a good potential for stabilizing lateritic soils in highway construction.

  12. Leaching characteristics of heavy metals during cement stabilization of fly ash from municipal solid waste incinerators

    Institute of Scientific and Technical Information of China (English)

    Shunwen LIANG; Jianguo JIANG; Yan ZHANG; Xin XU

    2008-01-01

    The leaching characteristics of heavy metals in products of cement stabilization of fly ash from a muni-cipal solid waste incinerator were investigated in this paper. The stabilization of heavy metals such as Cd, Pb, Cu, and Zn in fly ash from such incinerators was exam-ined through the national standard method in China based on the following-factors: additive quantity of cement and Na2S, curing time, and pH of leaching liquor. The results showed that as more additives were used, less heavy metals were leached except for Pb, which is sensitive to pH of the leachate, and the worse effect was observed for Cd. The mass ratio of cement to fly ash=10% is the most appropriate parameter according to the national standard method. When the hydration of cement was basically finished, stabilization of heavy metals did not vary after curing for 1 d. The mixtures of cement and fly ash had excellent adaptability to environmental pH. The pH of leachate was maintained at 7 when pH of leaching liquor varied from 3 to 11.

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

    Science.gov (United States)

    Kim, Sang-Oh; Shelby, Bo

    2008-04-01

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

  14. Longitudinal Stability of Social Competence Indicators in a Portuguese Sample: Q-Sort Profiles of Social Competence, Measures of Social Engagement, and Peer Sociometric Acceptance

    Science.gov (United States)

    Santos, António J.; Vaughn, Brian E.; Peceguina, Inês; Daniel, João R.

    2014-01-01

    This study examines the temporal stability (over 3 years) of individual differences in 3 domains relevant to preschool children's social competence: social engagement/motivation, profiles of behavior and personality attributes characteristic of socially competent young children, and peer acceptance. Each domain was measured with multiple…

  15. Longitudinal Stability of Social Competence Indicators in a Portuguese Sample: Q-Sort Profiles of Social Competence, Measures of Social Engagement, and Peer Sociometric Acceptance

    Science.gov (United States)

    Santos, António J.; Vaughn, Brian E.; Peceguina, Inês; Daniel, João R.

    2014-01-01

    This study examines the temporal stability (over 3 years) of individual differences in 3 domains relevant to preschool children's social competence: social engagement/motivation, profiles of behavior and personality attributes characteristic of socially competent young children, and peer acceptance. Each domain was measured with multiple…

  16. Morphologic characteristics and growth interface stability of nano-micron FeS_2 whiskers

    Institute of Scientific and Technical Information of China (English)

    HUANG Fei; WANG RuCheng; ZHANG WenLan; YAO YuZeng; PENG YanDong; KOU DaMing

    2009-01-01

    Micromorphology is further studied on the basis of our previous researches concerned with the na-no-micron FeS_2 whisker. There are obvious differences in the intensive degree, diameter and micro-morphology among the FeS_2 whiskers growing in different stages. From the early to late stage, the intensive degree increases, the diameter decreases, and the surface micro-morphology changes fol-lowing the regularity: protrusive nodulation → coarse → smooth → flat. According to the theory of crystal growth, the geological setting and processes of whisker formation, we discuss the stability and evolution of crystal growth interface of FeS_2 whisker occurring in Gengzhuang gold deposit (Shanxi Province, China). The results suggest that the negative temperature gradient and the supercooling appear in the early stage of the whisker growth, whereas the positive temperature gradient of reposeful state appears in the late stage. In the whisker growth stage, the component concentration changes through the three stages: severely nonhomogeneous in the early stage, relatively homogeneous in the middle stage, more homogeneous in the late stage. The general changing process of the interracial state is from unstable to stable. Micromorphology of FeS_2 whisker in Gengzhuang is the result of syn-ergism of temperature, component concentration and stability of crystal interface phase in hydro-thermal system. The micromorphology not only reflects the physical and chemical characteristics of the hydrothermal system during the whisker growth, but also indicates the stability characteristics of the interface phase and records the changing process of the whisker growth.

  17. Investigation of the Influence of Fuselage and Tail Surfaces on Low-speed Static Stability and Rolling Characteristics of a Swept-wing Model

    Science.gov (United States)

    Bird, John D; Lichtenstein, Jacob H; Jaquet, Byron M

    1952-01-01

    Results are presented of a wind-tunnel investigation to determine influence of the fuselage and tail on static stability and rotary derivatives in roll of a model having 45 degrees sweptback wing and tail surfaces. The wing alone and the model without the horizontal tail showed marginal longitudinal stability near maximum lift. The longitudinal stability of the complete model was satisfactory. The vertical tail produced larger increments of rate of change of lateral-force and yawing-moment coefficients with wing-tip helix angle than the fuselage or the horizontal tail.

  18. Trunk motion and gait characteristics of pregnant women when walking: report of a longitudinal study with a control group.

    Science.gov (United States)

    Gilleard, Wendy L

    2013-03-20

    A longitudinal repeated measures design over pregnancy and post-birth, with a control group would provide insight into the mechanical adaptations of the body under conditions of changing load during a common female human lifespan condition, while minimizing the influences of inter human differences. The objective was to investigate systematic changes in the range of motion for the pelvic and thoracic segments of the spine, the motion between these segments (thoracolumbar spine) and temporospatial characteristics of step width, stride length and velocity during walking as pregnancy progresses and post-birth. Nine pregnant women were investigated when walking along a walkway at a self-selected velocity using an 8 camera motion analysis system on four occasions throughout pregnancy and once post birth. A control group of twelve non-pregnant nulliparous women were tested on three occasions over the same time period. The existence of linear trends for change was investigated. As pregnancy progresses there was a significant linear trend for increase in step width (p = 0.05) and a significant linear trend for decrease in stride length (p = 0.05). Concurrently there was a significant linear trend for decrease in the range of motion of the pelvic segment (p = 0.03) and thoracolumbar spine (p = 0.01) about a vertical axis (side to side rotation), and the pelvic segment (p = 0.04) range of motion around an anterio-posterior axis (side tilt). Post-birth, step width readapted whereas pelvic (p = 0.02) and thoracic (p changes was greater than that accounted for with natural variability with re testing. As pregnancy progressed and post-birth there were significant linear trends seen in biomechanical changes when walking at a self-determined natural speed that were greater than that accounted for by natural variability with repeated testing. Not all adaptations were resolved by eight weeks post birth.

  19. Relationship between the medial longitudinal arch and the thoracic and lumbar curvatures with the static and dynamic stability in obese females

    Directory of Open Access Journals (Sweden)

    Abbas Rahimi

    2012-07-01

    Full Text Available Background and Aim: Reviewing the literature reveals a possible correlation between the obesity and the potential foot, spine and stability problems. Investigating the important parameters affecting the balance of obese people and prevention from falling are of high importance to reduce the resulting expenditures. This study aimed to assess the acts and the counter acts between the medial longitudinal arch (MLA and the thoracic and lumbar curvatures with the static and dynamic stability in obese females. Materials and Methods: Twenty eight obese females (age= 25±8 years old, BMI=37±4 and twenty nine non-obese females (age= 23±4 years old, BMI=23±3 were recruited in this case-control study with the cross-sectional technique. The MLA, spinal curve angles and the static or dynamic balance index of the subjects were measured using the navicular drop, flexible ruler and Biodex balance system tools, respectively. The static balance test was carried out using a modified Clinical Test of Sensory Interaction and Balance (CTSIB test in both the open and closed eyes while the subjects stood on their dominant legs. The order of the dynamic and static tests was selected randomly.Results: The findings of this study showed that in closed eye condition, most changes happened between the global Stability Index (SI and BMI; while in open eye condition, most changes occurred between the lateral-medial stability index and BMI (r=0.5. Also during an open eye condition, a moderate correlation was found between the navicular drop and lateral-medial stability index (r=0.05. In closed eyes condition, no significant changes were found between the SI and lumbar lordosis (r=0.0004; while a weak correlation was found between the thoracic curve angle and lateral-medial stability index (r=0.04.Conclusion: The dynamic stability is not only correlated to their BMI, but is highly dependent on their foot curvature types and slightly on their thoracic curve angle. Abdominal

  20. Effects of lysine residues on structural characteristics and stability of tau proteins

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myeongsang; Baek, Inchul; Choi, Hyunsung; Kim, Jae In; Na, Sungsoo, E-mail: nass@korea.ac.kr

    2015-10-23

    Pathological amyloid proteins have been implicated in neuro-degenerative diseases, specifically Alzheimer's, Parkinson's, Lewy-body diseases and prion related diseases. In prion related diseases, functional tau proteins can be transformed into pathological agents by environmental factors, including oxidative stress, inflammation, Aβ-mediated toxicity and covalent modification. These pathological agents are stable under physiological conditions and are not easily degraded. This un-degradable characteristic of tau proteins enables their utilization as functional materials to capturing the carbon dioxides. For the proper utilization of amyloid proteins as functional materials efficiently, a basic study regarding their structural characteristic is necessary. Here, we investigated the basic tau protein structure of wild-type (WT) and tau proteins with lysine residues mutation at glutamic residue (Q2K) on tau protein at atomistic scale. We also reported the size effect of both the WT and Q2K structures, which allowed us to identify the stability of those amyloid structures. - Highlights: • Lysine mutation effect alters the structure conformation and characteristic of tau. • Over the 15 layers both WT and Q2K models, both tau proteins undergo fractions. • Lysine mutation causes the increment of non-bonded energy and solvent accessible surface area. • Structural instability of Q2K model was proved by the number of hydrogen bonds analysis.

  1. 电动汽车驱动工况下纵向冲击问题研究%Study on electric vehicles’ longitudinal impact Characteristics under driving condition

    Institute of Scientific and Technical Information of China (English)

    甄子健; 陈潇凯; 夏超英; 林逸

    2016-01-01

    To solve the longitudinal impact problem of electric vehicles under the drive accelerating condition , the analy-ses of whole vehicle ’ s longitudinal dynamics and motor ’ s driving characteristics were conducted , and the major factors leading to the longitudinal impact problem of electric vehicles under the driving condition were found out . Then , the longitudinal impacts suffered by electric vehicles at the starting stage and the fast accelerating stage were studied by the electromechanical coupling simulations for integrative multi-body dynamics and motor control , and the method for suppressing longitudinal impacts of electric vehicles was presented .The method can reduce the lon-gitudinal impacts and improve vehicles ’ riding comfortableness .%针对电动汽车在驱动加速工况下存在纵向冲击的问题,进行了整车纵向动力学特性分析和电机驱动特性分析,找出了引起电动汽车在驱动工况下的纵向冲击的主要因素,并结合整车多体动力学和电机驱动控制进行机电耦合仿真,开展了电动汽车整车在起步阶段和加速过程控制策略转换阶段的纵向冲击研究,提出了抑制电动汽车纵向冲击的方法。该方法能在保证整车驱动性能的前提下,减小了纵向冲击度,提高了平顺性和舒适性。

  2. Using Simulations to Investigate the Longitudinal Stability of Alternative Schemes for Classifying and Identifying Children with Reading Disabilities

    Science.gov (United States)

    Schatschneider, Christopher; Wagner, Richard K.; Hart, Sara A.; Tighe, Elizabeth L.

    2016-01-01

    The present study employed data simulation techniques to investigate the 1-year stability of alternative classification schemes for identifying children with reading disabilities. Classification schemes investigated include low performance, unexpected low performance, dual-discrepancy, and a rudimentary form of constellation model of reading…

  3. Personality Types in Adolescence: Change and Stability and Links with Adjustment and Relationships--A Five-Wave Longitudinal Study

    Science.gov (United States)

    Meeus, Wim; Van de Schoot, Rens; Klimstra, Theo; Branje, Susan

    2011-01-01

    We examined change and stability of the 3 personality types identified by Block and Block (1980) and studied their links with adjustment and relationships. We used data from a 5-wave study of 923 early-to-middle and 390 middle-to-late adolescents, thereby covering the ages of 12-20 years. In Study 1, systematic evidence for personality change was…

  4. Improvement of activity, thermo-stability and fruit juice clarification characteristics of fungal exo-polygalacturonase.

    Science.gov (United States)

    Amin, Faiza; Bhatti, Haq Nawaz; Bilal, Muhammad; Asgher, Muhammad

    2017-02-01

    An extracellular exo-polygalacturonase (exo-PG) from Penicillium notatum was immobilized in sodium-alginate matrix through two different protocols, viz. covalent bonding and adsorption to enhance its catalytic activity, thermal stability and life-time properties for industrial applications. Covalent immobilization was more efficient in terms of high relative activity (45.89%) and immobilization yield (71.6%) as compared to adsorption. Immobilized exo-PG derivatives displayed maximum activities at pH 5.5 and 55°C as compared to free enzyme which showed its optimum activity at pH 6.0 and 50°C. The affinity of enzyme towards its substrate (Km(app)) was reduced after immobilization and Vmax of covalently immobilized exo-PG decreased to 66.7% while the Vmax value of adsorbed enzyme increased up to 150% as compared to free counterpart. Both immobilization techniques greatly enhanced the thermal stability profile of the enzyme. At 60°C, immobilized exo-PGs retained more than 90% of their residual activities after 60min of heating, while free enzyme did not show any activity at the same temperature. Thermodynamic properties (i.e., Ea, ΔH*, ΔS*and ΔG*) of the free and immobilized enzymes were also investigated. Sodium-alginate covalently immobilized and adsorbed enzymes showed excellent recycling efficiencies and retained 50.0% and 41.0% of original activities, respectively after seven consecutive batch reactions. Moreover, the immobilized enzymes treatment achieved promising results in turbidity and viscosity reduction as well as clarity amelioration in various fruit juices. Altogether catalytic, thermo-stability and fruit juices clarification characteristics of the immobilized ex-PGs suggest a high potential for biotechnological exploitability. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. AC over-current characteristics of YBCO coated conductor with copper stabilizer layer considering insulation layer

    Science.gov (United States)

    Du, H.-I.; Kim, M.-J.; Kim, Y.-J.; Lee, D.-H.; Han, B.-S.; Song, S.-S.

    2010-11-01

    Compared with the first-generation BSCCO wire, the YBCO thin-film wire boasts low material costs and high Jc and superior magnetic-field properties, among other strengths. Meanwhile, the previous BSCCO wire material for superconducting cables has been researched on considerably with regard to its post-wire quenching characteristics during the application of an alternating over-current. In this regard, the promising YBCO thin-film wire has yet to be further researched on. Moreover, still lacking is research on the YBCO thin-film wire with insulating layers, which is essential in the manufacture of superconducting cables, along with the testing of the application of an alternating over-current to the wire. In this study, YBCO thin-film wires with copper-stabilizing layers were used in testing alternating over-current application according to the presence or absence of insulating layers and to the thickness of such layers, to examine the post-quenching wire resistance increase and quenching trends. The YBCO thin-film wire with copper-stabilizing layers has a critical temperature of 90 K and a critical current of 85 A rms. Moreover, its current application cycle is 5.5 cycles, and its applied currents are 354, 517, 712, and 915 A peak. These figures enabled the YBCO thin-film wires with copper-stabilizing layers to reach 90, 180, 250, and 300 K, respectively, in this study. These temperatures serve as a relative reference to examine the post-quenching wire properties following the application of an alternating over-current.

  6. Effects of Waste Glass (WG on the Strength Characteristics of Cement Stabilized Expansive Soil

    Directory of Open Access Journals (Sweden)

    I.A.Ikara

    2015-11-01

    Full Text Available The study investigates the suitability of using waste glass (WG as admixture to cement stabilized black cotton soil (BCS for roads, fills and embankment. The soil was classified as A-7-5 and CH according to the American Association of State Highway and Transport Officials (AASHTO and the Unified Soil Classification System (USCS Classifications. Chemical analysis revealed that WG is rich in main oxides such as Silicon Oxide (69.2, Aluminium Oxide (2.29, Iron Oxide (1.57, Calcium Oxide (15.1 and Sodium Oxide (8.75. The soil was stabilized with 0, 2, 4, 6 and 8% cement and 0, 5 10, 15 and 20% WG by weight of the dry soil. Laboratory tests were carried out using the Standard Proctor (SP compactive efforts, California Bearing Ratio (CBR, Unconfined Compressive Strength (UCS, and compaction characteristics tests to evaluate the effectiveness of WG on Ordinary Portland cement (OPC stabilized BCS. The results obtained showed a decrease in the plasticity index (PI, liquid limit (LL, plastic limit (PL and increase Maximum Dry Density (MDD with increase in WG content in all cement proportions used and as compared to the values obtained for the natural soil. The peak 7 days UCS values of 1152kN/m2 was obtained at 8% OPC and 20% WG. Similarly, highest CBR value of 53.8% was obtained at an optimum blend of 8% OPC/20%WG. The results indicate that there is a potential in the use of WG as admixture to strengthen Black cotton soils.

  7. Leaching characteristics of construction materials and stabilization products containing waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Van der Sloot, H.A.; De Groot, G.J.; Wijkstra, J.

    1987-06-01

    Construction materials prepared with an admixture of waste material(s) and various stabilized waste products have been subjected to leaching studies. Static and dynamic leach tests are applied, in which the specimen to be studied is fully submerged in demineralized water or in seawater. At increasing time intervals the contact solution is renewed and the flux of elements into solution is measured. By studying a wide range of products containing waste materials attempts have been made to find common leaching characteristics. Materials studied to date comprise mortar specimen with a 20% cement replacement by pulverized coal ash, phosphate slag, light weight concrete with 50% of pulverized coal ash, stabilized phosphogypsum and stabilized products prepared from combinations of pulverized coal ash, phosphogypsum, incinerator ash, blast furnace slag, lime or cement. The alkalinity of the material, the open porosity of the product and the surface to volume ratio prove to be important factors in controlling the release of potential hazardous elements from materials containing waste products. In these studies leach parameters on (trace) elements are related to those of sodium. Since the interaction of sodium with the solid phase is usually small, sodium can be used as an indicator for the tortuosity of the product. Elements leached from cement-based waste products are mainly anionic species, like Mo, B, V, F and SO/sub 4/-ions, whereas leaching of metals, like Cu, Cd, Zn and Pb, is limited due to the high pH in the pore solution. The leaching experiments have been verified by scanning electron microscopy for major components on field samples and by measuring depth profiles in waste products for trace constituents using apparatus developed for this purpose.

  8. Developing methods and means to improve the sensitivity and stability characteristics of microwave sensors.

    Directory of Open Access Journals (Sweden)

    S. A. Vasyukov

    2014-01-01

    Full Text Available The paper considers the issues of designing the two-zone digital microwave sensors for the car alarm systems with high stability characteristics and capable of adaptation to external noise.The existing analog circuit-based microwave sensors for car alarm systems have a number of essential drawbacks:-- high level of intrinsic noise to cause the "false" alarm of response sensors;-- non-stable characteristics caused by the application of analog components at the environmental temperatures from -30 tо +60 С. This requires sensor readjustment during the transition from the summer season to the winter one, that is, essentially, hard to implement;-- uneasy adjustment of a mounted sensor with variable resistors;-- adjustment characterstic nonlinearity and high power consumption;-- impossible to implement the auto-compensation and adjustment algorithms to the repetitive external actions.To overcome abovementioned drawbacks the paper offers a circuit of digital microprocessor-based (PIC12F683 processor sensor with HF oscillator running in pulse operation mode (pulse ratio 20. It allows 6-8 times decrease of power consumption up to 2.1 mA and twice reduction of noise amplitude. Filters with useful output signal are of digital implementation. This enables us to reduce the number of electric components of sensor in half and to increase characteristics stability.For remote adjustment of sensor (with the key fob of car alarm or by GSM link 16 gradations of sensitivity are entered for zones of warning and alarm. The reference levels of digital comparators at each gradation of sensitivity are so generated that the sensor has a linear adjustment characteristic (distance of movable object detection versus gradation number.An application of digital signal processing and sensor capability of data exchange with the main alarm module through the bus allows us to implement the original algorithm of automatic correction of sensitivity across the warning zone of

  9. Characteristics and Stability of Mercury Vapor Adsorption over Two Kinds of Modified Semicoke

    Directory of Open Access Journals (Sweden)

    Zhang Huawei

    2014-01-01

    Full Text Available In an attempt to produce effective and lower price gaseous Hg0 adsorbents, two methods of HCl and KMnO4/heat treatment were used respectively for the surface modification of liginite semicoke from inner Mongolia. The different effects of modification process on the surface physical and chemical properties were analyzed. The characteristics and stability of mercury vapor adsorption over two kinds of modified semicoke were investigated. The results indicated that modification process caused lower micropore quantity and volume capacity of semicoke; the C-Cl functional groups, C=O bond and delocalized electron π on the surface of Cl-SC, the amorphous higher valency Mnx+, and O=C–OH functional groups on the surface of Mn-H-SC were the active sites for oxidation and adsorption of gaseous Hg0. Modification process led to higher mercury removal efficiency of semicoke at 140°C and reduced the stability of adsorbed mercury of semicoke in simulated water circumstance simultaneously.

  10. Characteristics and stability of mercury vapor adsorption over two kinds of modified semicoke.

    Science.gov (United States)

    Huawei, Zhang; Xiuli, Liu; Li, Wang; Peng, Liang

    2014-01-01

    In an attempt to produce effective and lower price gaseous Hg(0) adsorbents, two methods of HCl and KMnO4/heat treatment were used respectively for the surface modification of liginite semicoke from inner Mongolia. The different effects of modification process on the surface physical and chemical properties were analyzed. The characteristics and stability of mercury vapor adsorption over two kinds of modified semicoke were investigated. The results indicated that modification process caused lower micropore quantity and volume capacity of semicoke; the C-Cl functional groups, C=O bond and delocalized electron π on the surface of Cl-SC, the amorphous higher valency Mn (x+) , and O=C-OH functional groups on the surface of Mn-H-SC were the active sites for oxidation and adsorption of gaseous Hg(0). Modification process led to higher mercury removal efficiency of semicoke at 140°C and reduced the stability of adsorbed mercury of semicoke in simulated water circumstance simultaneously.

  11. GEOTECHNICAL CHARACTERISTICS OF LATERITIC SOIL STABILIZED WITH SAWDUST ASH-LIME MIXTURES

    Directory of Open Access Journals (Sweden)

    Emeka Segun Nnochiri

    2017-04-01

    Full Text Available This study assesses the geotechnical characteristics of lateritic soil and sawdust ash lime (SDAL mixtures. Preliminary tests were carried out on the natural soil sample for identification and classification purposes. The sawdust was mixed with lime for stabilization in the ratio 2:1. This mixture was thereafter added to the lateritic soil in varying proportions of 2, 4, 6, 8 and 10% by weight of soil. Addition of SDAL increased values of Optimum Moisture Content (OMC from 17.0% at 0% SDAL to 26.5% at 10% SDAL by weight of soil, also, values of Maximum Dry Density (MDD decreased from 2040 kg/m3 at 0% SDAL to 1415 kg/m3 at 10% SDAL. Values of Unconfined Compressive Strength (UCS increased from 38.58 kN/m2 at 0% SDAL to highest value of 129.63 kN/m2 at 6% SDAL. The values of liquid limits and plasticity index of the soil were effectively reduced with the addition of the SDAL, from 54.0% at 0% SDAL to 49.0% at 10% SDAL and from 13.7% at 0% SDAL to 12.5% at 10% SDAL respectively. It was therefore concluded that the sawdust ash lime (SDAL mixture can serve as a cheap soil stabilizing agent for poor lateritic soil.

  12. Combustion stability characteristics of the model chamber with various configurations of triplet impinging-jet injectors

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Chae Hoon [Chosun University, Gwangju (Korea, Republic of); Seol, Woo Seok [Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Shibanov, Alexander A. [Research Institute of Chemical Machine Building, Sergiev Posad (Russian Federation)

    2006-06-15

    Combustion stability characteristics in actual full-scale combustion chamber of a rocket engine are investigated by experimental tests with the model (sub-scale) chamber. The present hot-fire tests adopt the combustion chamber with three configurations of triplet impinging-jet injectors such as F-O-O-F, F-O-F, and O-F-O configurations. Combustion stability boundaries are obtained and presented by the parameters of combustion-chamber pressure and mixture (oxidizer/fuel) ratio. From the experimental tests, two instability regions are observed and the pressure oscillations have the similar patterns irrespective of injector configuration. But, the O-F-O injector configuration shows broader upper-instability region than the other configurations. To verify the instability mechanism for the lower and upper instability regions, air-purge acoustic test is conducted and the photograph of the flames is taken. As a result, it is found that the pressure oscillations in the two regions can be characterized by the first impinging point of hydraulic jets and pre-blowout combustion, respectively.

  13. 车辆调车纵向冲击特性研究%Research on Longitudinal Characteristics of Vehicle Shunting Impact

    Institute of Scientific and Technical Information of China (English)

    孙树磊; 李芾; 黄运华; 周张义; 丁军君

    2014-01-01

    基于车辆在编组连挂时的缓冲器冲击修正模型,通过建立多组列车冲击模型、车体刚度串联模型以及车体-钩缓装置-车体的串联模型,分别研究不同列车编组数量、不同冲击工况、不同车体刚度及不同阻抗特性的车辆缓冲器的组合对车辆纵向冲击特性的影响。结果表明,当冲击车和被冲击车的数量均大于2时,最大车钩力与车辆的数量间不存在明显关联,且此时冲击面的车钩力比编组为其他数量时的车钩力大,因此在进行车辆冲击试验及缓冲器性能测试时,冲击车和被冲击车的数量均大于2较为合理。当车体刚度较小、冲击速度较高时,车体刚度会对车钩力产生较大影响;冲击车和被冲击车具有不同阻抗特性的缓冲器组合冲击时,其最大车钩力和缓冲器行程会不同。因此,新型缓冲器的阻抗特性应设计为在低速冲击时具有柔性,从而保证低速冲击时的车钩力平缓增长,而在高速冲击时应体现为刚性,以限制缓冲器的最大行程。%On the basis of the vehicle impact equation and corrected draft gear model,the vehicle impact model, vehicle structure stiffness series model and vehicle-coupler-vehicle series model of multi-group vehicles were built to study the effect of different numbers of grouped vehicles,different conditions of vehicle impacting and vehicle body stiffness and combinations of draft gears of different resistance characteristics on longitudinal vehi-cle impulses.The results indicate as follows:when both the impacting train and impacted train consist of more than two vehicles,the maximum coupler force is not significantly related to the number of vehicles and the cou-pler force is larger than those of other grouping of vehicles so it is more rational to select the impacting train and impacted train of more than two vehicles in vehicle impact and gear performance tests;the small vehicle structure

  14. Effects of freeze-thaw on characteristics of new KMP binder stabilized Zn- and Pb-contaminated soils.

    Science.gov (United States)

    Wei, Ming-Li; Du, Yan-Jun; Reddy, Krishna R; Wu, Hao-Liang

    2015-12-01

    For viable and sustainable reuse of solidified/stabilized heavy metal-contaminated soils as roadway subgrade materials, long-term durability of these soils should be ensured. A new binder, KMP, has been developed for solidifying/stabilizing soils contaminated with high concentrations of heavy metals. However, the effects of long-term extreme weather conditions including freeze and thaw on the leachability and strength of the KMP stabilized contaminated soils have not been investigated. This study presents a systematic investigation on the impacts of freeze-thaw cycle on leachability, strength, and microstructural characteristics of the KMP stabilized soils spiked with Zn and Pb individually and together. For comparison purpose, Portland cement is also tested as a conventional binder. Several series of tests are conducted including the toxicity characteristic leaching procedure (TCLP), modified European Community Bureau of Reference (BCR) sequential extraction procedure, unconfined compression test (UCT), and mercury intrusion porosimetry (MIP). The results demonstrate that the freeze-thaw cycles have much less impact on the leachability and strength of the KMP stabilized soils as compared to the PC stabilized soils. After the freeze-thaw cycle tests, the KMP stabilized soils display much lower leachability, mass loss, and strength loss. These results are assessed based on the chemical speciation of Zn and Pb, and pore size distribution of the soils. Overall, this study demonstrates that the KMP stabilized heavy metal-contaminated soils perform well under the freeze-thaw conditions.

  15. Effect of spanwise pressure gradient on flow and heat transfer characteristics of longitudinal vortices embedded in a turbulent boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Min; Moon, Joo Hyun; Park, Jae Yong; Kim, Dae Yun; Lee, Seong Hyuk [Chung-Ang University, Seoul (Korea, Republic of)

    2015-02-15

    This study numerically investigated the influence of spanwise pressure gradient on heat transfer of a 3D turbulent boundary layer with longitudinal vortices. A 30° bend in the passage provided the spanwise pressure gradient. The longitudinal pair vortices were generated using a pair of delta winglets. The Reynolds-averaged Navier-Stokes and energy equations based on the conventional Reynolds stress model were used. The predictions agreed well with the experimental data for the straight plate. The turbulent boundary layer was significantly perturbed with the longitudinal vortices. The spanwise pressure gradient contributed to faster degradation of the longitudinal vortices and widened the perturbed flow region. The local Stanton number distributions were asymmetric because of the difference in the evolution of the longitudinal vortices in the curved region. Moreover, comparison showed that the local Stanton number in the downstream of the straight channel increased near the surface because of the secondary re-circulating vortex. The thickness of the thermal boundary layers increased in the streamwise direction because of the significant flow mixing and heat transfer.

  16. Heat transfer characteristics and entropy generation for wing-shaped-tubes with longitudinal external fins in cross-flow

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Sayed Ahmed E. Sayed; Mesalhy, Osama M.; Abdelatief, Mohamed A. [Zagazig University, Zagazig (Egypt)

    2016-06-15

    A numerical study is conducted to clarify heat transfer characteristics, effectiveness and entropy generation for a bundle of wingshaped-tubes attached to Longitudinal fins (LF) at downstream side. The air-side Re{sub a} ranged from 1.8 x 10{sup 3} to 9.7 x 10{sup 3} . The fin height (h{sub f}) and fin thickness (δ) have been changed as: (2 mm <= hf <= 12 mm) and (1.5 mm <= δ <= 3.5 mm). The analysis of entropy generation is based on the principle of minimizing the rate of total entropy generation that includes the generation of entropy due to heat transfer and friction losses. The temperature field around the wing-shaped-tubes with (LF) is predicted using commercial CFD FLUENT 6.3.26 software package. Correlations of Nu{sub a}, St{sub a}, and Bejan number (Be), as well as the irreversibility distribution ratio (Φ) in terms of Re{sub a} and design parameters for the studied bundle are presented. Results indicated that, installing fins with heights from 2 to 12 mm results in an increase in Nu{sub a} from 11 to 36% comparing with that of wing-shaped tubes without fins (NOF). The highest and lowest values of effectiveness(ε) at every value of the considered Re{sub a} range are occurred at hf = 6 mm and (NOF), espectively. The wing-shaped-tubes heat exchanger with hf = 6 mm has the highest values of (ε), efficiency index (η) and area goodness factor (G{sub a}) and also the lowest values of Φ and hence the best performance comparing with other arrangements. The minimum values of Φ are occurred at hf = 6 mm. (Be) decreases with increasing Re{sub a} for all studied hf. The heat transfer irreversibility predominates for (1800 <= Re{sub a} <= 4200) while the opposite is true for (6950 < Re{sub a} <= 9700). δ has negligible effect on Nu{sub a} and heat transfer irreversibility. Comparisons between the experimental and numerical results of the present study and those, previously, obtained for similar available studies showed good agreements.

  17. Disability acquisition and mental health: effect modification by demographic and socioeconomic characteristics using data from an Australian longitudinal study.

    Science.gov (United States)

    Aitken, Zoe; Simpson, Julie Anne; Bentley, Rebecca; Kavanagh, Anne Marie

    2017-09-18

    There is evidence of a causal relationship between disability acquisition and poor mental health, but the substantial heterogeneity in the magnitude of the effect is poorly understood and may be aetiologically informative. This study aimed to identify demographic and socioeconomic factors that modify the effect of disability acquisition on mental health. The Household, Income and Labour Dynamics in Australia Survey is a nationally representative longitudinal survey of Australian households that has been conducted annually since 2001. Four waves of data were included in this analysis, from 2011 to 2014. Individuals who acquired a disability (n=387) were compared with those who remained disability-free in all four waves (n=7936). Mental health was measured using the mental health subscale of the Short Form 36 (SF-36) general health questionnaire, which measures symptoms of depression, anxiety and psychological well-being. Linear regression models were fitted to estimate the effect of disability acquisition on mental health, testing for effect modification by key demographic and socioeconomic characteristics. To maximise causal inference, we used a propensity score approach with inverse probability of treatment weighting to control for confounding and multiple imputation using chained equations to assess the impact of missing data. On average, disability acquisition was associated with a 5-point decline in mental health score (estimated mean difference: -5.1, 95% CI -7.2 to -3.0). There was strong evidence that income and relationship status modified the effect, with more detrimental effects in the lowest (-12.5, 95% CI -18.5 to -6.5) compared with highest income quintile (-1.1, 95% CI -4.9 to 2.7) and for people not in a relationship (-8.8, 95% CI -12.9 to -4.8) compared with those who were (-3.7, 95% CI -6.1 to -1.4). Our results suggest that the detrimental effect of disability acquisition on mental health is substantially greater for socioeconomic

  18. Structure stability and water retention near saturation characteristics as affected by soil texture, and polyacrylamide concentration

    Science.gov (United States)

    Mamedov, Amrakh I.; Ekberli, Imanverdi A.; Ozturk, Hasan S.; Wagner, Larry E.; Norton, Darrell L.; Levy, Guy J.

    2017-04-01

    Studying the effects of soil properties and amendment application on soil structure stability is important for the development of effective soil management and conservation practices for sustaining semi-arid soil and water quality under climate change scenarios. Two sets of experiments were conducted to evaluate the effects of soil texture and soil amendment polyacrylamide (PAM) rate on soil structural stability expressed in terms of near saturation soil water retention and aggregate stability using the high energy (0-5 J kg-1) moisture characteristic (HEMC) method. Contribution of (i) soil type were assessed using 30 soil samples varying in texture from sandy to clay taken from long term cultivated lands, covering a range of crop and land management practices, and (ii) anionic PAM concentration (0, 10, 25, 50, 100 & 200 mg l-1) were tested on selected loam and clay soils. The water retention curves of slow and fast wetted soil samples were characterized by a modified van Genuchten (1980) model that provides (i) model parameters α and n, which represent the location of the inflection point and the steepness of the S-shaped water retention curves, and (ii) a composite soil structure index (SI =VDP/MS; VDP-volume of drainable pores, MS-modal suction). The studied treatments had, generally, considerable effects on the shape of the water retention curves (α and n). Soil type, PAM concentration and their interaction had significantly effects on the stability indices (SI, VDP and MS) and the model parameters (α and n). The SI and α increased, and ndecreased exponentially with the increase in soil clay content and PAM concentration, but the shape of curves were soil texture and management dependent, since predominant changes were observed in the various range of studied macropores (pore size > 60 μm). An exponential type of relationship existed between SI and α and n. Effect of PAM contribution and wetting condition was more pronounced in the loam soil at low PAM

  19. Quality Characteristics, Nutraceutical Profile, and Storage Stability of Aloe Gel-Papaya Functional Beverage Blend

    Directory of Open Access Journals (Sweden)

    Pushkala Ramachandran

    2014-01-01

    Full Text Available Aloe vera gel, well known for its nutraceutical potential, is being explored as a functional ingredient in a wide array of health foods and drinks. Processing of exotic fruits and herbal botanicals into functional beverage is an emerging sector in food industry. The present study was undertaken to develop a spiced functional RTS beverage blend using Aloe gel (AG and papaya. Aloe gel (30%, papaya pulp (15%, spice extract (5%, and citric acid (0.1% were mixed in given proportion to prepare the blend with TSS of 15 °Brix. The product was bottled, pasteurized, and stored at room temperature. The quality characteristics and storage stability of the spiced beverage blend (SAGPB were compared with spiced papaya RTS beverage (SPB. Periodic analysis was carried out up to five months for various physicochemical parameters, sugar profile, bioactive compounds, microbial quality, instrumental color, and sensory acceptability. The SAGPB exhibited superior quality characteristics compared to SPB both in fresh and in stored samples. The SPB was acceptable up to four months and SAGPB for five months. The results indicate that nutraceutical rich AG could be successfully utilized to develop functional fruit beverages with improved quality and shelf life.

  20. Characteristics of Oxidative Storage Stability of Canola Fatty Acid Methyl Ester Stabilised with Antioxidants

    Directory of Open Access Journals (Sweden)

    Tirto Prakoso

    2012-11-01

    Full Text Available The storage effects on the oxidation characteristics of fatty acid methyl ester of canola oil (CME were investigated in this study. CME stabilised with two antioxidants, i.e. 2,6-di-tert-bytyl-p-cresol (BHT and 6,6-di-tert-butyl-2, 2’-methylendi-p-cresol (BPH, was stored at 20, 40 and 60°C. The oxidation stability data were measured by the Rancimat test method and it was found that both BHT and BPH addition increased the oxidation resistance of the CME. The results showed that when BPH or BHT was added at a concentration of 100 ppm, the oxidation induction period of the neat CME samples increased from 5.53 h to 6.93 h and 6.14 h, respectively. Comparing both antioxidants, BPH proved to be more effective in increasing the oxidation resistance when both antioxidants were added at the same concentration. Furthermore, the oxidation induction time decreased linearly with the storage time. It was shown that the oxidation occurred rapidly in the first 8 weeks of storage. Later, a kinetic study was undertaken and first-order kinetics were applied to explain the oxidation characteristics of the CME added with antioxidants. This kinetic study focused on exploiting the activation energy values obtained from the Arrhenius equations. Also, the oxidation effects on other quality parameters, including acid value, peroxide value, kinematic viscosity, and water content, were examined.

  1. Stability of response characteristics of a Delphi panel: application of bootstrap data expansion

    Directory of Open Access Journals (Sweden)

    Cole Bryan R

    2005-12-01

    Full Text Available Abstract Background Delphi surveys with panels of experts in a particular area of interest have been widely utilized in the fields of clinical medicine, nursing practice, medical education and healthcare services. Despite this wide applicability of the Delphi methodology, there is no clear identification of what constitutes a sufficient number of Delphi survey participants to ensure stability of results. Methods The study analyzed the response characteristics from the first round of a Delphi survey conducted with 23 experts in healthcare quality and patient safety. The panel members had similar training and subject matter understanding of the Malcolm Baldrige Criteria for Performance Excellence in Healthcare. The raw data from the first round sampling, which usually contains the largest diversity of responses, were augmented via bootstrap sampling to obtain computer-generated results for two larger samples obtained by sampling with replacement. Response characteristics (mean, trimmed mean, standard deviation and 95% confidence intervals for 54 survey items were compared for the responses of the 23 actual study participants and two computer-generated samples of 1000 and 2000 resampling iterations. Results The results from this study indicate that the response characteristics of a small expert panel in a well-defined knowledge area are stable in light of augmented sampling. Conclusion Panels of similarly trained experts (who possess a general understanding in the field of interest provide effective and reliable utilization of a small sample from a limited number of experts in a field of study to develop reliable criteria that inform judgment and support effective decision-making.

  2. Flight-Determined Subsonic Longitudinal Stability and Control Derivatives of the F-18 High Angle of Attack Research Vehicle (HARV) with Thrust Vectoring

    Science.gov (United States)

    Iliff, Kenneth W.; Wang, Kon-Sheng Charles

    1997-01-01

    The subsonic longitudinal stability and control derivatives of the F-18 High Angle of Attack Research Vehicle (HARV) are extracted from dynamic flight data using a maximum likelihood parameter identification technique. The technique uses the linearized aircraft equations of motion in their continuous/discrete form and accounts for state and measurement noise as well as thrust-vectoring effects. State noise is used to model the uncommanded forcing function caused by unsteady aerodynamics over the aircraft, particularly at high angles of attack. Thrust vectoring was implemented using electrohydraulically-actuated nozzle postexit vanes and a specialized research flight control system. During maneuvers, a control system feature provided independent aerodynamic control surface inputs and independent thrust-vectoring vane inputs, thereby eliminating correlations between the aircraft states and controls. Substantial variations in control excitation and dynamic response were exhibited for maneuvers conducted at different angles of attack. Opposing vane interactions caused most thrust-vectoring inputs to experience some exhaust plume interference and thus reduced effectiveness. The estimated stability and control derivatives are plotted, and a discussion relates them to predicted values and maneuver quality.

  3. Microstructural evolution and thermal stability of thin CoCrTa/Cr films for longitudinal magnetic recording media

    Energy Technology Data Exchange (ETDEWEB)

    Ross, C.A.; Bertero, G. [Komag, Inc., Milpitas, CA (United States); Ross, F.M. [Lawrence Berkeley National Lab., CA (United States). National Center for Electron Microscopy; Tang, K. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering

    1998-01-01

    The microstructure and time-dependent magnetic properties of 2.8--60-nm-thick films of CoCrTa sputtered onto a Cr underlayer were measured. The thinnest films have a discontinuous microstructure with several CoCrTa nuclei forming on each Cr grain, with small angular misalignments from the exact epitaxial crystal orientation. For films of 10-nm thickness and above, the grains coalesce. There is evidence for stacking faults at all thicknesses although their appearance in atomic resolution micrographs changes with thickness. Magnetic switching volumes were measured from the change in coercivity with the scan rate of the external magnetic field. The ratio KV/kT of magnetic-to-thermal energy within the switching volume decreases as the film thickness decreases, and films thinner than 10 nm have KV/kT < 60 and would show significant decay of recorded data if used in longitudinal media applications. The magnetic switching volumes are similar in magnitude but generally larger than the physical grain volume indicating magnetic interactions between the grains.

  4. Some Audiological, Psychological, Educational and Behavioral Characteristics of Children with Bilateral Otitis Media with Effusion: A Longitudinal Study.

    Science.gov (United States)

    Silva, Phil A.; And Others

    1986-01-01

    A longitudinal study of 47 children with bilateral otitis media with effusion (OME) at age five compared with a group of non-OME children revealed that OME Ss continued to have significant hearing loss at subsequent ages, as well as language, speech, behavior, and reading difficulties. (Author/CL)

  5. The electric characteristics simulation and structural parameters calculation of Si-based stabilitron with stabilizing voltage 6,5 V

    Directory of Open Access Journals (Sweden)

    Koritko N. N.

    2009-06-01

    Full Text Available The results of an optimization simulation of original manufacturing process and electric characteristics of stabilitrons with stabilizing voltage Ust=(6,5±0,5 V are presented. The flow of manufacturing process of simulated stabilitron includes the n+-type guard rings regions formation in the р-type substrate; the р–n-junction formation in the р-type substrate; intermediate oxide formation; metal deposition. The stabilizing voltage and differential resistance of the stabilitron voltage-current characteristic reverse branch values were received as the result of calculations at the normal, reduced and high temperature.

  6. Experimental and analytical study of stability characteristics of natural circulation boiling water reactors during startup transient

    Science.gov (United States)

    Woo, Kyoungsuk

    Two-phase natural circulation loops are unstable at low pressure operating conditions. New reactor design relying on natural circulation for both normal and abnormal core cooling is susceptible to different types of flow instabilities. In contrast to forced circulation boiling water reactor (BWR), natural circulation BWR is started up without recirculation pumps. The tall chimney placed on the top of the core makes the system susceptible to flashing during low pressure start-up. In addition, the considerable saturation temperature variation may induce complicated dynamic behavior driven by thermal non-equilibrium between the liquid and steam. The thermal-hydraulic problems in two-phase natural circulation systems at low pressure and low power conditions are investigated through experimental methods. Fuel heat conduction, neutron kinetics, flow kinematics, energetics and dynamics that govern the flow behavior at low pressure, are formulated. A dimensionless analysis is introduced to obtain governing dimensionless groups which are groundwork of the system scaling. Based on the robust scaling method and start-up procedures of a typical natural circulation BWR, the simulation strategies for the transient with and without void reactivity feedback is developed. Three different heat-up rates are applied to the transient simulations to study characteristics of the stability during the start-up. Reducing heat-up rate leads to increase in the period of flashing-induced density wave oscillation and decrease in the system pressurization rate. However, reducing the heat-up rate is unable to completely prevent flashing-induced oscillations. Five characteristic regions of stability are discovered at low pressure conditions. They are stable single-phase, flashing near the separator, intermittent oscillation, sinusoidal oscillation and low subcooling stable regions. Stability maps were acquired for system pressures ranging 100 kPa to 400 kPa. According to experimental investigation

  7. Combustion Stability Characteristics of the Project Morpheus Liquid Oxygen / Liquid Methane Main Engine

    Science.gov (United States)

    Melcher, John C.; Morehead, Robert L.

    2014-01-01

    The project Morpheus liquid oxygen (LOX) / liquid methane (LCH4) main engine is a Johnson Space Center (JSC) designed 5,000 lbf-thrust, 4:1 throttling, pressure-fed cryogenic engine using an impinging element injector design. The engine met or exceeded all performance requirements without experiencing any in- ight failures, but the engine exhibited acoustic-coupled combustion instabilities during sea-level ground-based testing. First tangential (1T), rst radial (1R), 1T1R, and higher order modes were triggered by conditions during the Morpheus vehicle derived low chamber pressure startup sequence. The instability was never observed to initiate during mainstage, even at low power levels. Ground-interaction acoustics aggravated the instability in vehicle tests. Analysis of more than 200 hot re tests on the Morpheus vehicle and Stennis Space Center (SSC) test stand showed a relationship between ignition stability and injector/chamber pressure. The instability had the distinct characteristic of initiating at high relative injection pressure drop at low chamber pressure during the start sequence. Data analysis suggests that the two-phase density during engine start results in a high injection velocity, possibly triggering the instabilities predicted by the Hewitt stability curves. Engine ignition instability was successfully mitigated via a higher-chamber pressure start sequence (e.g., 50% power level vs 30%) and operational propellant start temperature limits that maintained \\cold LOX" and \\warm methane" at the engine inlet. The main engine successfully demonstrated 4:1 throttling without chugging during mainstage, but chug instabilities were observed during some engine shutdown sequences at low injector pressure drop, especially during vehicle landing.

  8. Study of recovery characteristics of 2nd generation HTS tapes with different stabilizers for resistive type superconducting fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Jie, E-mail: 1988725sheng@163.com; Zeng, Weina; Ma, Jun; Yao, Zhihao; Li, Zhuyong; Jin, Zhijian; Hong, Zhiyong

    2016-02-15

    Highlights: • Three methods of measuring the recovery time of HTS tapes are compared. • Four tapes with different stabilizers were tested to compare their recovery characteristics. • The HTS tapes with thinner stabilizers have better recovery characteristics. • Encapsulation makes the recovery characteristics of HTS tapes worse. • The results can be reference of the re-reclosed operation time interval. - Abstract: The resistive type superconducting fault current limiter (SFCL) is one of the most important superconducting power applications nowadays. As known, this type of SFCL is settled directly in the power transmission line. When a short fault happens, the temperature of the superconductors in the SFCL will increase sharply due to the huge generated heat. This means the superconductors need time to recover the superconducting properties and be ready for the next short fault. So the recovery characteristics become one of the most crucial features of the resistive type SFCL. In this paper, several different kinds of measuring methods are presented to calculate the recovery time of the HTS tapes, and comparison of these methods is also carried out by a standard test. On basis of this, samples with different kinds of stabilizers are used to explore the influence of stabilizer on their recovery characteristics. In addition, the influence of the encapsulation technology is also discussed in this paper.

  9. Loading Conditions and Longitudinal Strength

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1995-01-01

    Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength.......Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength....

  10. Loading Conditions and Longitudinal Strength

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1995-01-01

    Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength.......Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength....

  11. Long-term stability, reproducibility, and statistical sensitivity of a telemetry-instrumented dog model: A 27-month longitudinal assessment.

    Science.gov (United States)

    Fryer, Ryan M; Ng, Khing Jow; Chi, Liguo; Jin, Xidong; Reinhart, Glenn A

    2015-01-01

    ICH guidelines, as well as best-practice and ethical considerations, provide strong rationale for use of telemetry-instrumented dog colonies for cardiovascular safety assessment. However, few studies have investigated the long-term stability of cardiovascular function at baseline, reproducibility in response to pharmacologic challenge, and maintenance of statistical sensitivity to define the usable life of the colony. These questions were addressed in 3 identical studies spanning 27months and were performed in the same colony of dogs. Telemetry-instrumented dogs (n=4) received a single dose of dl-sotalol (10mg/kg, p.o.), a β1 adrenergic and IKr blocker, or vehicle, in 3 separate studies spanning 27months. Systemic hemodynamics, cardiovascular function, and ECG parameters were monitored for 18h post-dose; plasma drug concentrations (Cp) were measured at 1, 3, 5, and 24h post-dose. Baseline hemodynamic/ECG values were consistent across the 27-month study with the exception of modest age-dependent decreases in heart rate and the corresponding QT-interval. dl-Sotalol elicited highly reproducible effects in each study. Reductions in heart rate after dl-sotalol treatment ranged between -22 and -32 beats/min, and slight differences in magnitude could be ascribed to variability in dl-sotalol Cp (range=3230-5087ng/mL); dl-sotalol also reduced LV-dP/dtmax 13-22%. dl-Sotalol increased the slope of the PR-RR relationship suggesting inhibition of AV-conduction. Increases in the heart-rate corrected QT-interval were not significantly different across the 3 studies and results of a power analysis demonstrated that the detection limit for QTc values was not diminished throughout the 27month period and across a range of power assumptions despite modest, age-dependent changes in heart rate. These results demonstrate the long-term stability of a telemetry dog colony as evidenced by a stability of baseline values, consistently reproducible response to pharmacologic challenge and no

  12. Stability of vocational interests among the intellectually gifted from adolescence to adulthood: a 15-year longitudinal study.

    Science.gov (United States)

    Lubinski, D; Benbow, C P; Ryan, J

    1995-02-01

    A sample of 162 intellectually gifted adolescents (top 1%) were administered the Strong-Campbell Interest Inventory at age 13. Fifteen years later, they were administered the Strong again. This study evaluated the intra- and interindividual temporal stability of the 6 RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, Conventional) themes and the Strong's 23 Basic Interest Scales. Over the 15-year test-retest interval, RIASEC's median interindividual correlation for the 6 themes was .46; the median of all 162 intraindividual correlations was .57. Configural analyses of the most dominant theme at age 13 revealed that this theme was significantly more likely than chance to be either dominant or adjacent to the dominant theme at age 28--following RIASEC's hexagonal structure. For intellectually gifted individuals, it appears to be possible to forecast salient features of their adult RIASEC profile by assessing their vocational interests during early adolescence, but some RIASEC themes seem more stable than others.

  13. The breeding of two polyploid rice lines with the characteristic of polyploid meiosis stability

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Polyploidization is a basic feature of plant evolution. Nearly all of the main food, cotton and oil crops are polyploid. When ploidy levels increase, yields double; this phenomenon suggested a new strategy of rice breeding that utilizes wide crosses and polyploidization dual advantages to breed super rice. Because low seed set rates in polyploid rice usually makes it difficult to breed, the selection of Ph-liked gene lines was emphasized. After progenies of indica-japonica were identified and selected, two poly- ploid lines, PMeS-1 and PMeS-2 with Polyploid Meiosis Stability (PMeS) genes were bred. The proce- dure included seven steps: selecting parents, crossing or multiple crossing, back-crossing, doubling chromosomes, identifying the polyploid, and choosing plants with high seed set rates that can breed themselves into stable lines. The characteristics of PMeS were determined by observing meiotic be- haviors and by cross-identification of seed sets. PMeS-1 and PMeS-2, (japonica rice), have several characteristics different from other polyploid rice lines, including a higher rate of seed set (more than 65%, increasing to more than 70% in their F1 offspring); and stable meiotic behaviors (pairing with bi- valents and quarivalents nearly without over-quarivalent in prophase, nearly without lagging chromo- somes in metaphase and without micronuclei in anaphase and telophase). The latter was obviously different from control polyploid line Dure-4X, which displayed abnormal meiotic behaviors including a higher rate of multivalents, univalents and trivalents in prophase, lagging chromosomes in metaphase and micronuclei in anaphase and telophase. There were also three differences of the breeding method between PMeS lines and normal diploid lines: chromosomes doubling, polyploidism identifying and higher seed set testing. The selection of PMeS lines is the first step in polyploid rice breeding; their use will advance the progress of polyploid rice breeding, which will in

  14. The breeding of two polyploid rice lines with the characteristic of polyploid meiosis stability

    Institute of Scientific and Technical Information of China (English)

    CAI DeTian; HE YuChi; ZHANG DaoSheng; HE GuangCun; ZHU YingGuo; CHEN JianGuo; CHEN DongLing; DAI BingCheng; ZHANG Wei; SONG ZhaoJian; YANG ZhiFan; DU ChaoQun; TANG ZhiQiang

    2007-01-01

    Polyploidization is a basic feature of plant evolution. Nearly all of the main food, cotton and oil crops are polyploid. When ploidy levels increase, yields double; this phenomenon suggested a new strategy of rice breeding that utilizes wide crosses and polyploidization dual advantages to breed super rice.Because low seed set rates in polyploid rice usually makes it difficult to breed, the selection of Ph-liked gene lines was emphasized. After progenies of indica-japonica were identified and selected, two polyploid lines, PMeS-1 and PMeS-2 with Polyploid Meiosis Stability (PMeS) genes were bred. The procedure included seven steps: selecting parents, crossing or multiple crossing, back-crossing, doubling chromosomes, identifying the polyploid, and choosing plants with high seed set rates that can breed themselves into stable lines. The characteristics of PMeS were determined by observing meiotic behaviors and by cross-identification of seed sets. PMeS-1 and PMeS-2, (japonica rice), have several characteristics different from other polyploid rice lines, including a higher rate of seed set (more than 65%, increasing to more than 70% in their F1 offspring); and stable meiotic behaviors (pairing with bivalents and quarivalents nearly without over-quarivalent in prophase, nearly without lagging chromosomes in metaphase and without micronuclei in anaphase and telophase). The latter was obviously different from control polyploid line Dure-4X, which displayed abnormal meiotic behaviors including a higher rate of multivalents, univalents and trivalents in prophase, lagging chromosomes in metaphase and micronuclei in anaphase and telophase. There were also three differences of the breeding method between PMeS lines and normal diploid lines: chromosomes doubling, polyploidism identifying and higher seed set testing. The selection of PMeS lines is the first step in polyploid rice breeding; their use will advance the progress of polyploid rice breeding, which will in turn offer

  15. Effect of phase stability degradation of bismuth on sensor characteristics of nano-bismuth fixed electrode.

    Science.gov (United States)

    Lee, Gyoung-Ja; Kim, Chang Kyu; Lee, Min Ku; Rhee, Chang Kyu

    2010-12-15

    Effect of phase stability degradation of bismuth on sensor characteristics of nano-bismuth fixed electrode has been investigated using square-wave anodic stripping voltammetry technique, scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectroscopy. From the analyses of square-wave anodic stripping voltammograms (SWASV) repetitively measured on the nano-bismuth fixed electrode, it was found that the oxidation peak currents dropped by 81%, 68% and 59% for zinc, cadmium and lead, respectively, after the 100th measurement (about 400 min of operation time). The sphere bismuth nanoparticles gradually changed to the agglomerates with petal shape as the operation time increased. From the analyses of SEM images and XRD patterns, it is confirmed that the oxidation of Bi into BiOCl/Bi(2)O(2)CO(3) and the agglomeration of bismuth nanoparticles caused by the phase change decrease a reproducibility of the stripping voltammetric response. Moreover, most of the bismuth becomes BiOCl at pH 3.0 and bismuth hydroxide, Bi(OH)(3) at pH 7.0, which results in a significant decrease in sensitivity of the nano-bismuth fixed electrode.

  16. Contrasting the beam interaction characteristics of selected lasers with a partially stabilized zirconia bio-ceramic

    Science.gov (United States)

    Lawrence, J.

    2002-08-01

    Differences in the beam interaction characteristics of a CO2 laser, a Nd : YAG laser, a high power diode laser (HPDL) and an excimer laser with a partially stabilized zirconia bio-ceramic have been studied. A derivative of Beer-Lambert's law was applied and the laser beam absorption lengths of the four lasers were calculated as 33.55×10-3 cm for the CO2 laser, 18.22×10-3 cm for the Nd : YAG laser, 17.17×10-3 cm for the HPDL and 8.41×10-6 cm for the excimer laser. It was determined graphically that the fluence threshold values at which significant material removal was effected by the CO2 laser, the Nd : YAG laser, the HPDL and the excimer laser were 52 J cm-2, 97 J cm-2, 115 J cm-2 and 0.48 J cm-2, respectively. The thermal loading value for the CO2 laser, the Nd : YAG laser, the HPDL and the excimer laser were calculated as being 1.55 kJ cm-3, 5.32 kJ cm3, 6.69 kJ cm-3 and 57.04 kJ cm-3, respectively.

  17. Stability of active mantle upwelling revealed by net characteristics of plate tectonics.

    Science.gov (United States)

    Conrad, Clinton P; Steinberger, Bernhard; Torsvik, Trond H

    2013-06-27

    Viscous convection within the mantle is linked to tectonic plate motions and deforms Earth's surface across wide areas. Such close links between surface geology and deep mantle dynamics presumably operated throughout Earth's history, but are difficult to investigate for past times because the history of mantle flow is poorly known. Here we show that the time dependence of global-scale mantle flow can be deduced from the net behaviour of surface plate motions. In particular, we tracked the geographic locations of net convergence and divergence for harmonic degrees 1 and 2 by computing the dipole and quadrupole moments of plate motions from tectonic reconstructions extended back to the early Mesozoic era. For present-day plate motions, we find dipole convergence in eastern Asia and quadrupole divergence in both central Africa and the central Pacific. These orientations are nearly identical to the dipole and quadrupole orientations of underlying mantle flow, which indicates that these 'net characteristics' of plate motions reveal deeper flow patterns. The positions of quadrupole divergence have not moved significantly during the past 250 million years, which suggests long-term stability of mantle upwelling beneath Africa and the Pacific Ocean. These upwelling locations are positioned above two compositionally and seismologically distinct regions of the lowermost mantle, which may organize global mantle flow as they remain stationary over geologic time.

  18. Experimental Investigation on the Characteristics of Hydrodynamic Stabilities in Francis Hydroturbine Models

    Directory of Open Access Journals (Sweden)

    Wen-Tao Su

    2014-03-01

    Full Text Available This paper presents an experimental investigation of flow phenomena related to the characteristic frequencies of pressure fluctuation in Francis hydroturbine models. The experiments were carried out on two test rigs with two model runners having hydraulic similarities. Flow field around the guide vanes was measured with a particle image velocimetry (PIV on the first PIV test rig. Flow structures at the inlet region of runner and in draft tube at different operating conditions were visualized on another hydrodynamic test rig. Analyses of dominant frequency of unsteady hydraulic behaviors in the tested hydroturbines were performed. It was observed that the main frequency of flow over the guide vanes and the dominant frequency of channel vortex equal the blade passing frequency; the dominant frequency of flow separation at the suction side of blade inlet equals the vane passing frequency; the vortex rope in the draft tube displays a low-frequency nature. The flow instabilities and fluctuations directly influence the running of hydroturbine, thus these experimental results could provide important evidence for the stability study of a real hydroturbine.

  19. Influence of Brake Characteristics on Longitudinal Impulse of Train%制动特性对列车纵向冲动的影响

    Institute of Scientific and Technical Information of China (English)

    魏伟; 武星宇

    2012-01-01

    针对大秦线重载列车实际运用中出现的纵向冲动过大的问题,使用基于气体流动理论的空气制动特性仿真和基于刚体动力学的列车纵向动力学联合仿真方法,研究制动波传播的均匀性、制动波速、制动缸升压特性等制动系统特性对纵向冲动的影响.结果表明在制动波速不变条件下,制动波匀速传播与非匀速传播时列车纵向冲动水平基本一致;制动波速对列车车钩力影响显著,波速越高,车钩力越小;在列车制动能力不变的条件下,随着列车首尾车制动缸压强曲线开口度的收敛,纵向冲动明显降低,最大车钩力发生位置向列车后部移动.%Referring to excessive longitudinal impulse of Da-Qin heavy haul trains in practice, co-simulation of air braking characteristics based on gas flow theory and train longitudinal dynamics based on rigid body kinetics are used to study the effects of braking system characteristics (uniformity of brake propagation, brake propagation speed and pressure increasing speed of brake cylinder, etc. )on longitudinal impulse. The results show that under the conditions of same brake propagation speed, train longitudinal impulse of uniform and non-uniform brake propagation are basically consistent, and brake propagation speed affects coupler force significantly. The faster the brake speed is, the smaller the coupler force is. Under the conditions of same stopping distance with the convergence of front and rear vehicle's brake cylinder pressure curves, longitudinal impulse is reduced significantly, and the locations of maximum coupler force are moved towards the rear of train.

  20. Stability of the lower hybrid instability excited by longitudinal currents in a collisional, multi-ion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Venugopal, Chandu [School of Pure and Applied Physics, Mahatma Gandhi University, Priyadarshini Hills, Kottayam-686 560, Kerala (India); Kurian, M J [School of Pure and Applied Physics, Mahatma Gandhi University, Priyadarshini Hills, Kottayam-686 560, Kerala (India); Antony, S [School of Pure and Applied Physics, Mahatma Gandhi University, Priyadarshini Hills, Kottayam-686 560, Kerala (India); Anilkumar, C P [Indian Institute of Geomagnetism, Tirunelveli-627 011, Tamil Nadu (India); Renuka, G [Department of Physics, University of Kerala, Kariavattom, Thiruvananthapuram-695 581, Kerala (India)

    2007-05-15

    We have investigated the stability of the lower hybrid wave in a collisional plasma containing hydrogen and positively and negatively charged oxygen ions. The collisions of all the species in the plasma have been considered. The electrons, streaming parallel to the magnetic field, can excite the instability if their drift velocity exceeds the parallel phase velocity of the wave. This is true for both the weakly as well as the strongly collisional cases. If the ion collisions are neglected, the growth/damping rate depends on the electron collision frequency and is modified by a factor dependent directly on the number densities and square of the charges on the oxygen ions and inversely on the masses of these ions. Ion collisions, however only damp the wave; this damping being dependent also on the ion collision frequencies, in addition to the above dependencies. We find that the dispersion relation in the low collisional limit can account for lower hybrid waves in the observed frequency range.

  1. Genetic and environmental influences on personality trait stability and growth during the transition to adulthood: A three wave longitudinal study

    Science.gov (United States)

    Hopwood, Christopher J.; Donnellan, M. Brent; Blonigen, Daniel M.; Krueger, Robert F.; McGue, Matt; Iacono, William G.; Burt, S. Alexandra

    2010-01-01

    During the transition to adulthood individuals typically settle into adult roles in love and work. This transition also involves significant changes in personality traits that are generally in the direction of greater maturity and increased stability. Competing hypotheses have been offered to account for these personality changes: the intrinsic maturation hypothesis suggests that change trajectories are endogenous, whereas the life-course hypothesis suggests that these changes occur because of transactions with the social environment. This study investigated the patterns and origins of personality trait changes from ages 17 to 29 using 3 waves of Multidimensional Personality Questionnaire data provided by twins. Results suggest that a) trait changes were more profound in the first relative to the second half of the transition to adulthood; b) traits tend to become more stable during the second half of this transition, with all the traits yielding retest correlations between .74 and .78; c) negative affectivity declined over time and constraint increased over time; minimal change was observed on agentic or communal aspects of positive affectivity; and d) both genetic and non-shared environmental factors accounted for personality changes. Overall, these genetically-informed results support a life-course perspective on personality development during the transition to adulthood. PMID:21244174

  2. Complexity confers stability: Climate variability, vegetation response and sand transport on longitudinal sand dunes in Australia's deserts

    Science.gov (United States)

    Hesse, Paul P.; Telfer, Matt W.; Farebrother, Will

    2017-04-01

    The relationship between antecedent precipitation, vegetation cover and sand movement on sand dunes in the Simpson and Strzelecki Deserts was investigated by repeated (up to four) surveys of dune crest plots (≈25 × 25 m) over a drought cycle (2002-2012) in both winter (low wind) and spring (high wind). Vegetation varied dramatically between surveys on vegetated and active dune crests. Indices of sand movement had significant correlations with vegetation cover: the depth of loose sand has a strong inverse relationship with crust (cyanobacterial and/or physical) while the area covered by ripples has a strong inverse relationship with the areal cover of vascular plants. However, the relationship between antecedent rainfall and vegetation cover was found to be complex. We tentatively identify two thresholds; (1) >10 mm of rainfall in the preceding 90 days leads to rapid and near total cover of crust and/or small plants 400 mm of rainfall in the preceding three years leads to higher cover of persistent and longer-lived plants >50 cm tall. These thresholds were used to predict days of low vegetation cover on dune crests. The combination of seasonality of predicted bare-crest days, potential sand drift and resultant sand drift direction explains observed patterns of sand drift on these dunes. The complex vegetation and highly variable rainfall regime confer meta-stability on the dunes through the range of responses to different intervals of antecedent rainfall and non-linear growth responses. This suggests that the geomorphic response of dunes to climate variation is complex and non-linear.

  3. Utilizing dual-pass composite-ring architecture for a stabilized and wavelength-selectable single-longitudinal-mode erbium-doped fiber laser

    Science.gov (United States)

    Yeh, Chien-Hung; Zhuang, Yuan-Hong; Tsai, Ning; Chen, Jing-Heng; Chow, Chi-Wai

    2016-10-01

    In this paper, we propose using a dual-pass composite-ring construction for a stable and wavelength-tunable erbium-doped fiber (EDF) laser with a single-longitudinal-mode (SLM) output. According to the proposed laser architecture, a flattened output power spectrum within a 0.57 dB power variation can be obtained in the tuning range of 1530 to 1560 nm. In addition, the measured optical signal-to-noise ratio (OSNR) of each output wavelength can be larger than 62.1 dB. Furthermore, a stable and tunable dual-wavelength output of the proposed EDF laser scheme can also be achieved in the same operation range by using two optical filters inside a ring cavity. Here, the maximum and minimum mode spacing of dual-wavelength lasing in the proposed EDF laser are 28.01 and 1.04 nm, respectively. In this measurement, the SLM performance and output stability of the proposed EDF laser are analyzed and discussed experimentally.

  4. Dynamics of snow cover characteristics exerting influence on stability of the Svalbard permafrost

    Directory of Open Access Journals (Sweden)

    N. I. Osokin

    2016-01-01

    Full Text Available Climate variations result in changes of the snow cover characteristics which have a certain influence upon thermal state and stability of permafrost. Analysis of data of meteorological station Barentsburg (Svalbard and our own observations has revealed small change in the snow cover thickness for the period 1984–2015. At the same time, duration of the snow cover presence has shortened by 8%. In recent years, more than 60% of the snow cover thickness was formed during the early third of the cold season which adversely affects a rate of the ground freezing. Durations of thaws increased from 12 to 22 days, and the rainfall amount decreased during the cold period from 60 to 120 mm. The largest increase in the thaw duration (by a factor of 7 and decrease of the rainfall amount (by a factor of 8 fall on January and February. Summing up of the thaw duration and the rainfall amount for the 5‑year periods demonstrated significant growth of both. It should be noted also that, according to data of the Barentsburg station and our ones, in a few last years, these parameters reached anomalously high values. Appearance of anomalous values of the snow cover thickness as well as of the dates of its onset became more frequent. For the last decade, recurrence of anomalous values of the snow cover thickness increased: one event for 2.4 years before 2000, and one occurrence of anomalous thickness for 1.4 years since 2001. The later onset of snow cover resulted in shortening of duration of its presence. Occurrence of anomalous duration of the snow cover presence was observed once for 4.3 years before 2001, and once for 3.3 years after 2000.

  5. Effect of Channel Layer Thickness on Characteristics and Stability of Amorphous Hafnium-Indium-Zinc Oxide Thin Film Transistors

    Science.gov (United States)

    Kim, Sun-Jae; Lee, Soo-Yeon; Lee, Young-Wook; Lee, Woo-Geun; Yoon, Kap-Soo; Kwon, Jang-Yeon; Han, Min-Koo

    2011-02-01

    We investigated the channel layer thickness dependence of the characteristics and stability in amorphous hafnium indium zinc-oxide (HIZO) thin film transistors (TFTs). HIZO TFTs were prepared with various channel thicknesses from 400 to 700 Å. In HIZO TFTs, carrier concentration is considerably high, which leads to channel layer thickness dependence. The threshold voltages of TFTs negatively shifted as the channel thickness increased. The threshold voltage shift at a high temperature is more severe in TFTs with thicker channel layers. The channel thickness dependence of the bias stability of HIZO TFTs is closely related to the back interface, rather than the bulk state.

  6. Longitudinal and latitudinal variations in dynamic characteristics of the MLT (70−95km: a study involving the CUJO network

    Directory of Open Access Journals (Sweden)

    Y. Murayama

    2004-01-01

    Full Text Available The newly-installed MFR (medium frequency radar at Platteville (40°N, 105°W has provided the opportunity and impetus to create an operational network of middle- latitude MFRs stretching from 81°W–142°E. CUJO (Canada U.S. Japan Opportunity comprises systems at London (43°N, 81°W, Platteville (40°N, 105°W, Saskatoon (52°N, 107°W, Wakkanai (45°N, 142°E and Yamagawa (31°N, 131°E. It offers a significant 7000km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12–14° at two longitudes. Annual climatologies involving both height and frequency versus time contour plots for periods from 8h to 30 days, show that the changes with longitude are very significant and distinctive, often exceeding the local latitudinal variations. Comparisons with models and the recent UARS-HRDI global analysis of tides are discussed. The fits of the horizontal wave numbers of the longer period oscillations are provided in unique frequency versus time contour plots and shown to be consistent with the expected dominant modes. Annual climatologies of planetary waves (16 day, 2 day and gravity waves reveal strong seasonal and longitudinal variations. Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides; climatology

  7. Longitudinal and latitudinal variations in dynamic characteristics of the MLT (70-95km): a study involving the CUJO network

    Science.gov (United States)

    Manson, A.; Meek, C.; Chshyolkova, T.; Avery, S.; Thorsen, D.; MacDougall, J.; Hocking, W.; Murayama, Y.; Igarashi, K.; Namboothiri, S.; Kishore, P.

    2004-02-01

    . The newly-installed MFR (medium frequency radar) at Platteville (40N, 105W) has provided the opportunity and impetus to create an operational network of middle- latitude MFRs stretching from W-E. CUJO (Canada U.S. Japan Opportunity) comprises systems at London (N, 81W), Platteville (40N, 105W), Saskatoon (52N, 107W), Wakkanai (45N, 142E) and Yamagawa (31N, 131E). It offers a significant 7000km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12-14) at two longitudes. Annual climatologies involving both height and frequency versus time contour plots for periods from 8h to 30 days, show that the changes with longitude are very significant and distinctive, often exceeding the local latitudinal variations. Comparisons with models and the recent UARS-HRDI global analysis of tides are discussed. The fits of the horizontal wave numbers of the longer period oscillations are provided in unique frequency versus time contour plots and shown to be consistent with the expected dominant modes. Annual climatologies of planetary waves (16 day, 2 day) and gravity waves reveal strong seasonal and longitudinal variations.

  8. A Novel Strategy for Designing and Manufacturing a Fixed Wing MAV for the Purpose of Increasing Maneuverability and Stability in Longitudinal Axis

    Directory of Open Access Journals (Sweden)

    Mohammadreza Radmanesh

    2014-01-01

    Full Text Available In this study, a novel simple strategy is proposed to choose and accommodate an airfoil based on the effects of airfoil type and plan-form shape on the flight performance of a micro air vehicle. In this strategy, after defining flight mission, the weight of the micro air vehicle is estimated and then, aerodynamic parameters and thrust force are calculated. In the next step, some different plan-forms and airfoils are investigated to be selected for decreasing the stall region in high attack anglesby open source software named XFLR5. Having calculated the aerodynamic center, the pitching moment needed to stabilize the micro air vehicle is computed. Due to the static margin, the airfoil camber line is changed to stabilize the micro air vehicle and then, its thickness is improved to reach to a high aerodynamic characteristic. To evaluate the software results, some flight tests are performed which then compared to the software results that show a good agreement. Finally, some adjustments and improvements are made on the micro air vehicle and then, its performance is obtained by the flight tests. The flight test results show it has an excellent aerodynamic performance, stability and maneuverability.

  9. The longitudinal association of venue stability with consistent condom use among female sex workers in two Mexico-USA border cities.

    Science.gov (United States)

    Gaines, T L; Rudolph, A E; Brouwer, K C; Strathdee, S A; Lozada, R; Martinez, G; Goldenberg, S M; Rusch, M L A

    2013-07-01

    We examined the relationship between venue stability and consistent condom use (CCU) among female sex workers who inject drugs (FSW-IDUs; n = 584) and were enrolled in a behavioural intervention in two Mexico-USA border cities. Using a generalized estimating equation approach stratified by client type and city, we found venue stability affected CCU. In Tijuana, operating primarily indoors was significantly associated with a four-fold increase in the odds of CCU among regular clients (odds ratio [OR]: 3.77, 95% confidence interval [CI]: 1.44, 9.89), and a seven-fold increase among casual clients (OR: 7.18, 95% CI: 2.32, 22.21), relative to FSW-IDUs spending equal time between indoor and outdoor sex work venues. In Ciudad Juarez, the trajectory of CCU increased over time and was highest among those operating primarily indoors. Results from this analysis highlight the importance of considering local mobility, including venue type and venue stability, as these characteristics jointly influence HIV risk behaviours.

  10. The longitudinal association of venue stability with consistent condom use among female sex workers in two Mexico–USA border cities

    Science.gov (United States)

    Gaines, T L; Rudolph, A E; Brouwer, K C; Strathdee, S A; Lozada, R; Martinez, G; Goldenberg, S M; Rusch, M L A

    2014-01-01

    Summary We examined the relationship between venue stability and consistent condom use (CCU) among female sex workers who inject drugs (FSW-IDUs; n = 584) and were enrolled in a behavioural intervention in two Mexico–USA border cities. Using a generalized estimating equation approach stratified by client type and city, we found venue stability affected CCU. In Tijuana, operating primarily indoors was significantly associated with a four-fold increase in the odds of CCU among regular clients (odds ratio [OR]: 3.77, 95% confidence interval [CI]: 1.44, 9.89), and a seven-fold increase among casual clients (OR: 7.18, 95% CI: 2.32, 22.21), relative to FSW-IDUs spending equal time between indoor and outdoor sex work venues. In Ciudad Juarez, the trajectory of CCU increased over time and was highest among those operating primarily indoors. Results from this analysis highlight the importance of considering local mobility, including venue type and venue stability, as these characteristics jointly influence HIV risk behaviours. PMID:23970766

  11. Stability

    Directory of Open Access Journals (Sweden)

    Nada S. Abdelwahab

    2017-05-01

    Full Text Available The present work concerns with the development of stability indicating the RP-HPLC method for simultaneous determination of guaifenesin (GUF and pseudoephedrine hydrochloride (PSH in the presence of guaifenesin related substance (Guaiacol. GUC, and in the presence of syrup excepients with minimum sample pre-treatment. In the developed RP-HPLC method efficient chromatographic separation was achieved for GUF, PSH, GUC and syrup excepients using ODS column as a stationary phase and methanol: water (50:50, v/v, pH = 4 with orthophosphoric acid as a mobile phase with a flow rate of 1 mL min−1 and UV detection at 210 nm. The chromatographic run time was approximately 10 min. Calibration curves were drawn relating the integrated area under peak to the corresponding concentrations of PSH, GUF and GUC in the range of 1–8, 1–20, 0.4–8 μg mL−1, respectively. The developed method has been validated and met the requirements delineated by ICH guidelines with respect to linearity, accuracy, precision, specificity and robustness. The validated method was successfully applied for determination of the studied drugs in triaminic chest congestion® syrup; moreover its results were statistically compared with those obtained by the official method and no significant difference was found between them.

  12. Power Effects on High Lift, Stability and Control Characteristics of the TCA Model Tested in the LaRC 14 x 22 Ft Wind Tunnel

    Science.gov (United States)

    Glessner, Paul T.

    1999-01-01

    The TCA-2 wind-tunnel test was the second in a series of planned tests utilizing the 5% Technology Concept Airplane (TCA) model. Each of the tests was planned to utilize the unique capabilities of the NASA Langley 14'x22' and the NASA Ames 12' test facilities, in order to assess specific aspects of the high lift and stability and control characteristics of the TCA configuration. However, shortly after the completion of the TCA-1 test, an early projection of the Technology Configuration (TC) identified the need for several significant changes to the baseline TCA configuration. These changes were necessary in order to meet more stringent noise certification levels, as well as, to provide a means to control dynamic structural modes. The projected changes included a change to the outboard wing (increased aspect ratio and lower sweep) and a reconfiguration of the longitudinal control surfaces to include a medium size canard and a reduced horizontal tail. The impact of these proposed changes did not affect the TCA-2 test, because it was specifically planned to address power effects on the empennage and a smaller horizontal tail was in the plan to be tested. However, the focus of future tests was reevaluated and the emphasis was shifted away from assessment of TCA specific configurations to a more general assessment of configurations that encompass the projected design space for the TC.

  13. Estabilidad de la capacidad antioxidante y pH en leche humana refrigerada durante 72 horas: estudio longitudinal Stability of the antioxidant capacity and pH of human milk refrigerated for 72 hours: longitudinal study

    Directory of Open Access Journals (Sweden)

    M. Miranda

    2011-08-01

    infant at least for the first six months of life. Its properties include nutrients intake and, particularly, to provide the infant with several beneficial compounds improving his growth and protecting him from the diseases typical of this time period. These properties justify the manipulating processes before its intake in order to promote and warrant the adherence to it, both at the hospital and at home, being more important in premature infants and/or with low birth weight given their increased vulnerability, is spite of the fact that during these processes some of its properties may be partially lost. There exist, therefore, an interest in knowing the impact of the procedures applied to human milk on its qualitative properties, such as the antioxidant capacity. Objective: This work assesses the stability of the antioxidant capacity of human milk during its storage at 4º C, longitudinally from its extraction until 48 h of refrigeration, as well as the pH changes. Method: the milk from 30 healthy women was analyzed. The milk's antioxidant capacity was assessed by the following parameters: total antioxidant capacity and level of malondialdehyde. The results obtained showed that pH decreases gradually from the storage beginning, whereas the antioxidant capacity remains constant for the first 24 hours, with a different result depending on the parameter used, and thereafter significant changes were observed. Conclusions: In case of needing extraction and storage of maternal milk before its consumption, the storage time should be minimized, preferably less than 24 hours in order to preserve the oxidative stress.

  14. Effects of dune stabilization on vegetation characteristics and soil properties at multiple scales in Horqin Sandy Land, Northern China

    Institute of Scientific and Technical Information of China (English)

    XiaoAn Zuo; XueYong Zhao; ShaoKun Wang; Xin Zhou; Peng Lv; Jing Zhang

    2015-01-01

    Ecological patterns and processes in dune ecosystems have been a research focus in recent years, however information on how dune stabilization influences vegetation and soil at different spatial scales is still lacking. In this study, we measured vegetation characteristics and soil properties across three spatial scales (10, 100 and 1,000 m2) along gradient dune stabi-lization stages (mobile dune, semi-fixed dune and fixed dune) in Horqin Sandy Land, Northern China. Vegetation cover over all scales significantly increased with degree of dune stabilization, as well as species richness and C/N ratio at 10 m2 scale. Species richness significantly increased with the increase in measured scales at each stage of dune stabilization and was higher in fixed dune than that in mobile dune and semi-fixed dune at 100 and 1,000 m2 scales. Over all scales, aboveground biomass was lower in mobile dune than that in semi-fixed dune and fixed dune, and soil organic C, total N, EC, very fine sand and silt+clay contents were higher in fixed dune than those in mobile dune and semi-fixed dune. These results suggest that along the gradient dune stabilization, species richness has strong spatial scale-dependence, but vege-tation cover, aboveground biomass and soil properties is generally scale independent (i.e., the pattern of response is con-sistent across all scales). Effect of dune stabilization on vegetation and soil over all spatial scales results in the positive correlation among vegetation cover, species richness, biomass, soil organic C, total N, C/N, EC, very fine sand and silt+clay along the gradient dune stabilization. In addition, species richness at the smallest scale (10 m2) has more sensitive response to dune stabilization. Thus, the monitoring strategies at small scales are essential to detect changes of species diversity in semiarid dune ecosystems.

  15. Longitudinal and latitudinal variations in dynamic characteristics of the MLT (70−95km): a study involving the CUJO network

    OpenAIRE

    Manson, A. H.; Meek, C. E.; Chshyolkova, T.; Avery, S. K.; Thorsen, D.; MacDougall, J.W.; Hocking, W.; Murayama, Y.; Igarashi, K; Namboothiri, S. P.; P Kishore

    2004-01-01

    The newly-installed MFR (medium frequency radar) at Platteville (40°N, 105°W) has provided the opportunity and impetus to create an operational network of middle- latitude MFRs stretching from 81°W–142°E. CUJO (Canada U.S. Japan Opportunity) comprises systems at London (43°N, 81°W), Platteville (40°N, 105°W), Saskatoon (52°N, 107°W), Wakkanai (45°N, 142°E) and Yamagawa (31°N, 131°E). It offers a significant 7000km longitudinal sector in the North American-Pacific region, and...

  16. Longitudinal and latitudinal variations in dynamic characteristics of the MLT (70?95km): a study involving the CUJO network

    OpenAIRE

    Manson, A. H.; Meek, C. E.; Chshyolkova, T.; Avery, S. K.; Thorsen, D.; MacDougall, J.W.; Hocking, W.; Murayama, Y.; Igarashi, K; Namboothiri, S. P.; P Kishore

    2004-01-01

    International audience; The newly-installed MFR (medium frequency radar) at Platteville (40°N, 105°W) has provided the opportunity and impetus to create an operational network of middle- latitude MFRs stretching from 81°W?142°E. CUJO (Canada U.S. Japan Opportunity) comprises systems at London (43°N, 81°W), Platteville (40°N, 105°W), Saskatoon (52°N, 107°W), Wakkanai (45°N, 142°E) and Yamagawa (31°N, 131°E). It offers a significant 7000km longitudinal sector in the North American-Pacific regio...

  17. Polymer Nanofibers with Outstanding Thermal Conductivity and Thermal Stability: Fundamental Linkage between Molecular Characteristics and Macroscopic Thermal Properties

    CERN Document Server

    Zhang, Teng; Luo, Tengfei

    2014-01-01

    Polymer nanofibers with high thermal conductivities and outstanding thermal stabilities are highly desirable in heat transfer-critical applications such as thermal management, heat exchangers and energy storage. In this work, we unlock the fundamental relations between the thermal conductivity and thermal stability of polymer nanofibers and their molecular characteristics by studying the temperature-induced phase transitions and thermal transport of a series of polymer nanofibers. Ten different polymer nanofibers with systematically chosen molecular structures are studied using large scale molecular dynamics simulations. We found that high thermal conductivity and good thermal stability can be achieved in polymers with rigid backbones, exemplified by {\\pi}-conjugated polymers, due to suppressed segmental rotations and large phonon group velocities. The low probability of segmental rotation does not only prevent temperature-induced phase transition but also enables long phonon mean free paths due to reduced di...

  18. Emission characteristics and combustion instabilities in an oxy-fuel swirl-stabilized combustor

    Institute of Scientific and Technical Information of China (English)

    Guo-neng LI; Hao ZHOU; Ke-fa CEN

    2008-01-01

    This paper presents an experimental study on the emission characteristics and combustion instabilities of oxy-fuel combustions in a swirl-stabilized combustor.Different oxygen concentrations(Xoxy=25%-45%,where Xoxy is oxygen concentra-tion by volume),equivalence ratios(=0.75~1.15)and combustion powers(CP=1.08~2.02kW)were investigated in the oxy-fuel (CH4/CO2/O2)combustions,and reference cases(Xoxy=25%~35%,Cha/N2/O2 flames)were covered.The results show that the oxygen concentration in the oxidant stream significantly affects the combustion delay in the oxy-fuel flames,and the equivalence ratio has a slight effect,whereas the combustion power shows no impact.The temperature levels of the oxy-fuel flames inside the combustion chamber are much higher(up to 38.7%)than those of the reference cases.Carbon monoxide was vastly producedwhen Xoxy>35% or >0.95 in the oxy-fuel flames,while no nitric oxide was found in the exhaust gases because no N2 participates in the combustion process.The combustion instability of the oxy-fuel combustion is very different from those of the reference cases with similar oxygen content.Oxy-fuel combustions excite strong oscillations in all cases studied Xoxy=25%~45%.However,no pressure fluctuations were detected in the reference cases when Xoxy>28.6% accomplished by heavily sooting flames which were not found in the oxy-fuel combustions.Spectrum analysis shows that the frequency of dynamic pressure oscillations exhibits randomness in the range of 50~250 Hz,therefore resulting in a very small resultant amplitude.Temporal oscillations are very strong with amplitudes larger than 200 Pa,even short time fast Fourier transform(FFT)analysis(0.08 s)shows that the pressure amplitude can be larger than 40 Pa.

  19. Longitudinal change in the use of services in autism spectrum disorder: understanding the role of child characteristics, family demographics, and parent cognitions.

    Science.gov (United States)

    Siller, Michael; Reyes, Nuri; Hotez, Emily; Hutman, Ted; Sigman, Marian

    2014-05-01

    The aim of this study was to identify child characteristics, family demographics, and parent cognitions that may affect access to early intervention, special education, and related services. The sample included 70 families of young children with autism spectrum disorders. All parents were enrolled in a short education program, providing them with basic information and resources on advocating for a young child with autism spectrum disorders (Parent Advocacy Coaching). Longitudinal change in children's intervention program in the community was evaluated over a period of about 27 months, starting 12 months prior to enrollment in Parent Advocacy Coaching. Results revealed large individual differences in the intensity of children's individual and school-based services. Despite this variability, only two child characteristics (age, gender) emerged as independent predictors. In contrast, the intensity of children's intervention programs was independently predicted by a broad range of demographic characteristics, including parental education, child ethnicity and race, and family composition. Finally, even after child characteristics and family demographics were statistically controlled, results revealed associations between specific parental cognitions (parenting efficacy, understanding of child development) and the subsequent rate of change in the intensity of children's intervention programs. Implications for improving educational programs that aim to enhance parent advocacy are discussed.

  20. Impact of atomization technique on the stability and transport efficiency of nebulized liposomes harboring different surface characteristics.

    Science.gov (United States)

    Lehofer, Bernhard; Bloder, Florian; Jain, Pritesh P; Marsh, Leigh M; Leitinger, Gerd; Olschewski, Horst; Leber, Regina; Olschewski, Andrea; Prassl, Ruth

    2014-11-01

    The objective of this study was to evaluate the impact of nebulization on liposomes with specific surface characteristics by applying three commercially available inhaler systems (air-jet, ultrasonic and vibrating-mesh). Conventional liposome formulations composed of phosphatidylcholine and cholesterol were compared to sterically stabilized PEGylated liposomes and cationic polymer coated liposomes.Liposomes of similar size (between 140 and 165 nm in diameter with polydispersity indices atomization process, while polymer coated and especially positively charged liposomes showed enhanced leakage. The release rates for the hydrophilic model drug system were highest for the vibrating-mesh nebulizers regardless of the surface characteristics of the liposomes (increasing from 10% to 20% and 50% for the conventional, PEGylated and positively charged formulations, respectively). In view of surface modified liposomes our data suggest that drug delivery via nebulization necessitates the finding of a compromise between nebulizer efficiency, formulation stability and drug release profile to accomplish the development of tailored formulations suitable for advanced inhalation therapy.

  1. Trapped Field Characteristics of Stacked YBCO Thin Plates for Compact NMR Magnets: Spatial Field Distribution and Temporal Stability.

    Science.gov (United States)

    Hahn, Seungyong; Kim, Seok Beom; Ahn, Min Cheol; Voccio, John; Bascuñán, Juan; Iwasa, Yukikazu

    2010-06-01

    This paper presents experimental and analytical results of trapped field characteristics of a stack of square YBCO thin film plates for compact NMR magnets. Each YBCO plate, 40 mm × 40 mm × 0.08 mm, has a 25-mm diameter hole at its center. A total of 500 stacked plates were used to build a 40-mm long magnet. Its trapped field, in a bath of liquid nitrogen, was measured for spatial field distribution and temporal stability. Comparison of measured and analytical results is presented: the effects on trapped field characteristics of the unsaturated nickel substrate and the non-uniform current distribution in the YBCO plate are discussed.

  2. Longitudinal stability control of orchard cable-driven hanging transport system%果园钢索牵引货运系统负载纵向稳定性控制

    Institute of Scientific and Technical Information of China (English)

    杨洲; 李伟; 李君; 李雪平; 薛坤鹏

    2015-01-01

    为有效抑制果园钢索牵引悬挂式货运系统吊重的纵向偏摆,该文采用根轨迹校正法设计了系统纵向运行稳定性控制器。在忽略侧向运动影响的前提下,利用拉格朗日方程建立了线性化的纵向动力学模型。通过在左半复平面添加2个零点,对系统的根轨迹进行了校正。仿真和试验结果表明:所提出的只考虑吊重在纵向平面内运动的数学模型能够表述原系统运动特性,设计的控制器可快速衰减纵向偏摆,抑制吊重纵向摆动角度在±1.5°以内,将摆角角速度幅度极值减小至10%。该研究为悬挂货运系统的纵向稳定性控制提供了参考依据。%A cable-driven hanging transport system has the characteristics of labor saving, economic efficiency and good revenue, along with good prospect for increasing orchard utilization. Compared with the wheeled carrier and crawler, it can meet the demand of the complex mountainous topography. Both during and after transfer, the load motion of the hanging system can cause load swings, which is undesirable especially in the variations of acceleration. The longitudinal oscillations may lead to the instability of system and damage of agricultural goods. The aim of this paper is to develop an effective control method for the load motion that produces short travel time with suppressed load swing and satisfies operational constraints. Due to the nonlinearities of spatial three-dimensional motion of transferred load, the dynamics of the cable-driven hanging transport system showed complexity with coupled motion of load. In fact, the lateral movement had little effect on the longitudinal stability due to the low transport speed of cable and lager curvature radius of rails, which could be ignored in the development of plant equations. In order to effectively suppress the longitudinal load swings, the Lagrange equations were utilized and a mathematical model of the transport system was

  3. Effects of Homofermentative Lactic Acid Bacterial Inoculants on the Fermentation and Aerobic Stability Characteristics of Low Dry Matter Corn Silages

    OpenAIRE

    SUCU, Ekin; FİLYA, İsmail

    2014-01-01

    This study was carried out to determine the effects of homofermentative lactic acid bacterial inoculants on the fermentation and aerobic stability characteristics of low dry matter corn silages. Corn was harvested at the milk stage. Inoculant-1188 (Pioneer®, USA; Inoculant A) and Maize-All (Alltech, UK; Inoculant B) were used as homofermentative lactic acid bacterial inoculants. Inoculants were applied to silages 1.5 x 106 colony forming units/g levels. Silages with no additive served as co...

  4. Extension of Characteristic Equation Method to Stability Analysis of Equilibrium Points for Closed—Loop PWM Power Switching Converters8

    Institute of Scientific and Technical Information of China (English)

    YanfengCHEN; ShuishengQIU; 等

    1999-01-01

    An extension of characteristic equation analysis method to the stability analysis of equilibrium points for closed-loop PWM power switching converters is introduced based on equivalent small parameter method.The basic principle of the method is described in detail.The provided example shows that the method,incorporating with the system's state-plane trajectories,offers the advantages of both simplicity and practicality.

  5. Spatiotemporal characteristics of atrial fibrillation electrograms: A novel marker for arrhythmia stability and termination

    Directory of Open Access Journals (Sweden)

    Shivshankar Thanigaimani, PhD

    2017-02-01

    Conclusions: Spatiotemporal stabilization of CFAE favors AF sustenance and its destabilization heralds AF termination. The STSI of CFE-m is more representative of AF dynamics than are the STSI of DF, sequential mean CFE-m, or median DF.

  6. Influences of NOM composition and bacteriological characteristics on biological stability in a full-scale drinking water treatment plant.

    Science.gov (United States)

    Park, Ji Won; Kim, Hyun-Chul; Meyer, Anne S; Kim, Sungpyo; Maeng, Sung Kyu

    2016-10-01

    The influences of natural organic matter (NOM) and bacteriological characteristics on the biological stability of water were investigated in a full-scale drinking water treatment plant. We found that prechlorination decreased the hydrophobicity of the organic matter and significantly increased the high-molecular-weight (MW) dissolved organic matter, such as biopolymers and humic substances. High-MW organic matter and structurally complex compounds are known to be relatively slowly biodegradable; however, because of the prechlorination step, the indigenous bacteria could readily utilise these fractions as assimilable organic carbon. Sequential coagulation and sedimentation resulted in the substantial removal of biopolymer (74%), humic substance (33%), bacterial cells (79%), and assimilable organic carbon (67%). Rapid sand and granular activated carbon filtration induced an increase in the low-nucleic-acid content bacteria; however, these bacteria were biologically less active in relation to enzymatic activity and ATP. The granular activated carbon step was essential to securing biological stability (the ability to prevent bacterial growth) by removing the residual assimilable organic carbon that had formed during the ozone treatment. The growth potential of Escherichia coli and indigenous bacteria were found to differ in respect to NOM characteristics. In comparison with E. coli, the indigenous bacteria utilised a broader range of NOM as a carbon source. Principal component analysis demonstrated that the measured biological stability of water could differ, depending on the NOM characteristics, as well as on the bacterial inoculum selected for the analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Simulations of foot stability during gait characteristic of ankle dorsiflexor weakness in the elderly.

    Science.gov (United States)

    Gefen, A

    2001-12-01

    Falls are common among the elderly and often cause injuries. They most frequently occut during walking and are associated with the chronic deterioration in neuromuscular and sensory systems, as well as with ankle dorsiflexor muscular weakness and lowered endurance of these muscles to fatigue. In the present study, a three-dimensional (3-D) finite element model of the structure of the foot was utilized to determine the effects of ankle dorsiflexor muscle weakness on the structural stability of the foot and, consequently, on the risk of falls during gait. The medial-lateral tendency of instability of the foot during gait in such conditions of weakness was analyzed by means of this model to identify the most important muscles used in controlling foot stability in affected individuals. The values of the eccentricity of the center of pressure under the heel during foot placement were used to indicate the degree of foot stability. The computational analysis indicated that it is the tibialis anterior muscle's weakness that dramatically decreases foot stability. Clinical investigation is now needed to correlate the significance of tibialis anterior muscle weakness with other known risk factors affecting the tendency to falls among the elderly, e.g., deterioration of sensory abilities. Rehabilitation practitioners and physical therapists may apply the present analytic approach to evaluate the stability of a foot before treatment and compare the predicted with the actual therapeutic results in terms of optimization of foot-ground pressure.

  8. Analog-Computer Investigation of Effects of Friction and Preload on the Dynamic Longitudinal Characteristics of a Pilot-Airplane Combination

    Science.gov (United States)

    Crane, Harold L.

    1961-01-01

    With an electric analog computer, an investigation has been made of the effects of control frictions and preloads on the transient longitudinal response of a fighter airplane during abrupt small attitude corrections. The simulation included the airplane dynamics, powered control system, feel system, and a simple linearized pseudopilot. Control frictions at the stick pivot and at the servo valve as well as preloads of the stick and valve were considered individually and in combinations. It is believed that the results which are presented in the form of time histories and vector diagrams present a more detailed illustration of the effects of stray forces and compensating forces in the longitudinal control system than has previously been available. Consistent with the results of previous studies, the present results show that any of these four friction and preload forces caused some deterioration of the response. However, even a small amount of valve friction caused an oscillatory pitching response during which the phasing of the valve friction was such that it caused energy to be fed into the pitching oscillation of the air-plane. Of the other friction and preload forces which were considered, it was found that stick preload was close to 180 deg. out of phase with valve friction and thus could compensate in large measure for valve friction as long as the cycling of the stick encompassed the trim point. Either stick friction or valve preload provided a smaller stabilizing effect primarily through a reduction in the amplitude of the resultant force vector acting on the control system. Some data were obtained on the effects of friction when the damping or inertia of the control system or the pilot lag was varied.

  9. Correlations between biochemical characteristics and foam-forming and -stabilizing ability of whey and casein hydrolysates.

    Science.gov (United States)

    van der Ven, Cornelly; Gruppen, Harry; de Bont, Dries B A; Voragen, Alphons G J

    2002-05-08

    Whey protein and casein were hydrolyzed with 11 commercially available enzymes. Foam properties of 44 samples were measured and were related to biochemical properties of the hydrolysates using statistical data analysis. All casein hydrolysates formed high initial foam levels, whereas whey hydrolysates differed in their foam-forming abilities. Regression analysis using the molecular weight distribution of whey hydrolysates as predictors showed that the hydrolysate fraction containing peptides of 3-5 kDa was most strongly related to foam formation. Foam stability of whey hydrolysates and of most casein hydrolysates was inferior to that of the intact proteins. The foam stability of casein hydrolysate foams was correlated to the molecular weight distribution of the hydrolysates; a high proportion of peptides >7 kDa, composed of both intact casein and high molecular weight peptides, was positively related to foam stability.

  10. Impact of physicochemical characteristics on the oxidative stability of fish oil microencapsulated by spray-drying.

    Science.gov (United States)

    Drusch, Stephan; Serfert, Yvonne; Scampicchio, Matteo; Schmidt-Hansberg, Benjamin; Schwarz, Karin

    2007-12-26

    The aim of the present research was to identify principal parameters determining the oxidative stability of microencapsulated fish oil. Microcapsules were prepared by spray-drying using different types of n-octenylsuccinate-derivatized starch, gum Arabic, sugar beet pectin, sodium caseinate, and/or glucose syrup. Two principal components to classify the different microcapsules accounting for up to 79% of the variance were identified. The principal components were determined by physicochemical parameters reflecting the emulsifying ability of the encapsulant and the drying behavior of the parent emulsion. Microcapsules, which were identified by principal component analysis to be significantly different, exhibited a low stability upon storage, showing that the principal components and, thus, the underlying physicochemical parameters analyzed in the present study are correlated with core material stability.

  11. The study of stability, combustion characteristics and performance of water in diesel emulsion fuel

    Directory of Open Access Journals (Sweden)

    Syafiq Zulkifli

    2017-01-01

    Full Text Available A single cylinder diesel engine study of water in diesel emulsions was conducted to investigate the stability effect of emulsion fuel on three different fuel blends and the water emulsification effect on the engine performance. Emulsified fuels contained 2% of surfactant including Span 80 Tween 80 and tested 10 HLB number. The blends also varied of 5%, 10% and 15% of water in diesel ratios namely as BSW5, BSW10 and BSW15. The fuel blends performance was tested using a single cylinder, direct injection diesel engine, operating at 1860 rpm. The results on stability reveal that high shear homogenizer yields more stability on emulsion fuel than mechanical stirrer and ultrasonic water bath. The engine performance results show that the ignition delay and peak pressure increase with the increment of water percentage up to 15%. However, the results indicate the increment of water percentage is also shows a significant decrease in engine power.

  12. More than the "X" Factor! A Longitudinal Investigation of the Psychological Characteristics of Developing Excellence in Musical Development

    Science.gov (United States)

    Macnamara, Aine; Collins, Dave

    2009-01-01

    Current findings in talent identification and development research have acknowledged that potential for future performance cannot be identified from single evaluations of performance or anthropometric factors (e.g. Abbott and Collins 2004). Recognising the role of psychological characteristics at elite levels, it is pertinent to consider the role…

  13. Clinical characteristics and evaluation of LDL-cholesterol treatment of the Spanish Familial Hypercholesterolemia Longitudinal Cohort Study (SAFEHEART)

    Science.gov (United States)

    Familial hypercholesterolemia (FH) patients are at high risk for premature coronary heart disease (CHD). Despite the use of statins, most patients do not achieve an optimal LDL-cholesterol goal. The aims of this study are to describe baseline characteristics and to evaluate Lipid Lowering Therapy (L...

  14. Thin-Section CT Characteristics and Longitudinal CT Follow-up of Chemotherapy Induced Interstitial Pneumonitis: A Retrospective Cohort Study.

    Science.gov (United States)

    Lee, Han Na; Kim, Mi Young; Koo, Hyun Jung; Kim, Sung-Soo; Yoon, Dok Hyun; Lee, Jae Cheol; Song, Jin Woo

    2016-01-01

    To describe the computed tomography (CT) features of chemotherapy-induced interstitial pneumonitis (CIIP) with longitudinal follow-up.The study was approved by the local ethics committee. One hundred consecutive patients with CIIP between May 2005 and March 2015 were retrospectively enrolled. The initial CT was reviewed by 2 independent chest radiologists and categorized into 1 of 4 CT patterns in accordance with the 2013 guidelines for idiopathic interstitial pneumonia: nonspecific interstitial pneumonia (NSIP), organizing pneumonia (OP), hypersensitivity pneumonitis (HP) mimicking desquamative interstitial pneumonitis, and diffuse alveolar damage (DAD). We assessed semiquantitative analysis on a 5% scale to assess the extent of parenchymal abnormalities (emphysema, reticulation, ground-glass opacity, consolidation, honeycombing cyst) and their distribution on initial (n = 100), subsequent (n = 87), and second follow-up CT (n = 48). Interval changes in extent on follow-up CT were compared using paired t test. The clinic-radiologic factors were compared between Group 1 (NSIP and OP patterns) and Group 2 (HP and DAD patterns) using χ and independent t tests.The most common pattern of CIIP on the initial CT was HP (51%), followed by NSIP (23%), OP (20%), and DAD (6%). Diffuse ground-glass opacity was the most common pulmonary abnormality. The predominant distribution was bilateral (99%) and symmetric (82%), with no craniocaudal (60%) or axial (79%) dominance. Subsequent and second follow-up CTs showed decreased extent of total pulmonary abnormalities (P CIIP, Group 2 CIIP was more likely to be caused by molecularly targeted drugs (P = 0.030), appeared earlier (P = 0.034), and underwent more complete resolution (P CIIP is appropriate and practical in interpreting radiological findings.

  15. Which psychological, social and physical environmental characteristics predict changes in physical activity and sedentary behaviors during early retirement? A longitudinal study

    Directory of Open Access Journals (Sweden)

    Delfien Van Dyck

    2017-05-01

    Full Text Available Background In the context of healthy ageing, it is necessary to identify opportunities to implement health interventions in order to develop an active lifestyle with sufficient physical activity and limited sedentary time in middle-aged and older adults. The transition to retirement is such an opportunity, as individuals tend to establish new routines at the start of retirement. Before health interventions can be developed, the psychological, social and physical environmental determinants of physical activity and sedentary behaviors during early retirement should be identified, ideally with longitudinal studies. The aim of this paper was first to examine whether psychological, social and physical environmental factors at the start of retirement predict longitudinal changes in physical activity and sedentary behaviors during the first years of retirement. Second, moderating effects of gender and educational levels were examined. Methods This longitudinal study was conducted in Flanders, Belgium. In total, 180 recently retired (>1 month, <2 years at baseline adults completed a postal questionnaire twice (in 2012–2013 and two years later in 2014–2015. The validated questionnaire assessed socio-demographic information, physical activity, sedentary behaviors, and psychological, social and physical environmental characteristics. Multiple moderated hierarchic regression analyses were conducted in SPSS 22.0. Results Higher perceived residential density (p < 0.001 and lower aesthetics (p = 0.08 predicted an increase in active transportation (adjusted R2 = 0.18. Higher baseline self-efficacy was associated with an increase in leisure-time physical activity (p = 0.001, adjusted R2 = 0.13. A more positive perception of old age (p = 0.04 and perceiving less street connectivity (p = 0.001 were associated with an increase in screen time (adjusted R2 = 0.06. Finally, higher baseline levels of modeling from friends (p = 0.06 and lower

  16. Characteristics of sugar surfactants in stabilizing proteins during freeze-thawing and freeze-drying.

    Science.gov (United States)

    Imamura, Koreyoshi; Murai, Katsuyuki; Korehisa, Tamayo; Shimizu, Noriyuki; Yamahira, Ryo; Matsuura, Tsutashi; Tada, Hiroko; Imanaka, Hiroyuki; Ishida, Naoyuki; Nakanishi, Kazuhiro

    2014-06-01

    Sugar surfactants with different alkyl chain lengths and sugar head groups were compared for their protein-stabilizing effect during freeze-thawing and freeze-drying. Six enzymes, different in terms of tolerance against inactivation because of freeze-thawing and freeze-drying, were used as model proteins. The enzyme activities that remained after freeze-thawing and freeze-drying in the presence of a sugar surfactant were measured for different types and concentrations of sugar surfactants. Sugar surfactants stabilized all of the tested enzymes both during freeze-thawing and freeze-drying, and a one or two order higher amount of added sugar surfactant was required for achieving protein stabilization during freeze-drying than for the cryoprotection. The comprehensive comparison showed that the C10-C12 esters of sucrose or trehalose were the most effective through the freeze-drying process: the remaining enzyme activities after freeze-thawing and freeze-drying increased at the sugar ester concentrations of 1-10 and 10-100 μM, respectively, and increased to a greater extent than for the other surfactants at higher concentrations. Results also indicate that, when a decent amount of sugar was also added, the protein-stabilizing effect of a small amount of sugar ester through the freeze-drying process could be enhanced. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  17. Structure, electrical characteristics, and high-temperature stability of aerosol jet printed silver nanoparticle films

    Science.gov (United States)

    Rahman, Md Taibur; McCloy, John; Ramana, C. V.; Panat, Rahul

    2016-08-01

    Printed electronics has emerged as a versatile eco-friendly fabrication technique to create sintered nanoparticle (NP) films on arbitrary surfaces with an excellent control over the film microstructure. While applicability of such films for high-temperature applications is not explored previously, herein we report the high-temperature electrical stability of silver (Ag) metal NP films fabricated using an Aerosol Jet based printing technique and demonstrate that this behavior is dictated by changes in the film microstructure. In-situ high temperature (24-500 °C) impedance spectroscopy measurements show that the real part of the impedance increases with increasing temperature up to 150 °C, at which point a decreasing trend prevails until 300 °C, followed again by an increase in impedance. The electrical behavior is correlated with the in-situ grain growth of the Ag NP films, as observed afterwards by scanning electron microscopy and X-ray diffraction (XRD), and could be tailored by controlling the initial microstructure through sintering conditions. Using combined diffraction and spectroscopic analytical methods, it is demonstrated the Aerosol Jet printed Ag NP films exhibit enhanced thermal stability and oxidation resistance. In addition to establishing the conditions for stability of Ag NP films, the results provide a fundamental understanding of the effect of grain growth and reduction in grain boundary area on the electrical stability of sintered NP films.

  18. Performance characteristics and long-term calibration stability of a beam monitor for a proton scanning gantry

    Energy Technology Data Exchange (ETDEWEB)

    Nichiporov, D.F., E-mail: nichipor@indiana.ed [Indiana University Cyclotron Facility, 2401 Milo B. Sampson Ln., Bloomington, IN 47408 (United States); Klyachko, A.V.; Solberg, K.A. [Indiana University Cyclotron Facility, 2401 Milo B. Sampson Ln., Bloomington, IN 47408 (United States); Zhao, Q. [Midwest Proton Radiotherapy Institute, 2425 Milo B. Sampson Ln., Bloomington, IN 47408 (United States)

    2011-02-15

    A monitor for a uniformly scanned beam was designed and constructed by the Indiana University Cyclotron Facility for use in a clinical proton gantry at the Midwest Proton Radiotherapy Institute. The beam monitor is a thin-walled, wide-aperture ionization chamber, which provides information about dose, beam size, symmetry, flatness, and position. Several characteristics of the monitor's performance were studied, including linearity in dose rate, reproducibility, recombination correction, and dependence on both radiation field size and gantry angle. Additionally, stability of the detector output was analyzed using daily monitor calibrations performed over a period of 21 months. The beam monitor was found to meet design requirements for linearity ({+-}1%), calibration stability ({+-}2%), and stability of response as a function of gantry angle ({+-}1%). Beam monitor calibration statistics also revealed a sine-like yearly trend with a {+-}2% maximum deviation from the average. These and other beam monitor test results are presented and discussed in the context of the detector design. Design changes aimed at further improving the detector's performance characteristics are proposed.

  19. The Nonlinear Stability Prediction and FEM Modeling of High-Speed Spindle System with Joints Dynamic Characteristics

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2014-01-01

    Full Text Available When predicting the nonlinear stability of high-speed spindle system, it is necessary to create an accurate model that reflects the dynamic characteristics of the whole system, including the spindle-bearing joint and spindle-holder-tool joints. In this paper, the distribution spring model of spindle-holder-tool joints was built with the consideration of its dynamic characteristics; the five-DOF dynamic model of the angle contact ball bearing was also established to study the influence of speed and preload on the spindle-bearing joint, both of which were used in the general whole complete spindle system FEM model. The rationality of the model was verified by comparison with the FRF of traditional rigid model and experiments. At last, the influences of speed and cutting force on the nonlinear stability were analyzed by amplitude spectrum, bifurcation, and Poincaré mapping. The results provided a theoretical basis and an evaluating criterion for nonlinear stability prediction and product surface quality improvement.

  20. Thermal stability and energy harvesting characteristics of Au nanorods: harsh environment chemical sensing

    Science.gov (United States)

    Karker, Nicholas; Dharmalingam, Gnanaprakash; Carpenter, Michael A.

    2015-05-01

    Monitoring the levels of polluting gases such as CO and NOx from high temperature (500°C and higher) combustion environments requires materials with high thermal stability and resilience that can withstand harsh oxidizing and reducing environments. Au nanorods (AuNRs) have shown potential in plasmonic gas sensing due to their catalytic activity, high oxidation stability, and absorbance sensitivity to changes in the surrounding environment. By using electron beam lithography, AuNR geometries can be patterned with tight control of the rod dimensions and spacings, allowing tunability of their optical properties. Methods such as NR encapsulation within an yttria-stabilized zirconia overcoat layer with subsequent annealing procedures will be shown to improve temperature stability within a simulated harsh environment. Since light sources and spectrometers are typically required to obtain optical measurements, integration is a major barrier for harsh environment sensing. Plasmonic sensing results will be presented where thermal energy is harvested by the AuNRs, which replaces the need for an external incident light source. Results from gas sensing experiments that utilize thermal energy harvesting are in good agreement with experiments which use an external incident light source. Principal component analysis results demonstrate that by selecting the most "active" wavelengths in a plasmonic band, the wavelength space can be reduced from hundreds of monitored wavelengths to just four, without loss of information about selectivity of the AuNRs. By combining thermal stability, the thermal energy harvesting capability, and the selectivity in gas detection (achieved through multivariate analysis), integration of plasmonic sensors into combustion environments can be greatly simplified.

  1. Impact of silage additives on aerobic stability and characteristics of high-moisture maize during exposure to air, and on fermented liquid feed

    DEFF Research Database (Denmark)

    Canibe, Nuria; Kristensen, Niels Bastian; Jensen, Bent Borg

    2014-01-01

    Aims To (i) measure the aerobic stability- and describe the characteristics, during aeration, of high-moisture maize (HMM) treated with various additives, and (ii) describe the microbial characteristics of fermented liquid feed (FLF) added HMM. Methods and Results Four treatments were prepared...... during aeration- and impact of additives on the aerobic stability of HMM depended on the characteristics of the samples. No blooming of Enterobacteriaceae was observed in FLF containing c. 20 g HMM 100 g−1. Significance and Impact of the Study The impact of silage additives on aerobic stability of HMM...

  2. Reliable characteristics and stabilization of on-membrane SOI MOSFET-based components heated up to 335 °C

    Science.gov (United States)

    Amor, S.; André, N.; Gérard, P.; Ali, S. Z.; Udrea, F.; Tounsi, F.; Mezghani, B.; Francis, L. A.; Flandre, D.

    2017-01-01

    In this work we investigate the characteristics and critical operating temperatures of on-membrane embedded MOSFETs from an experimental and analytical point of view. This study permits us to conclude the possibility of integrating electronic circuitry in the close vicinity of micro-heaters and hot operation transducers. A series of calibrations and measurements has been performed to examine the behaviors of transistors, inverters and diodes, actuated at high temperature, on a membrane equipped with an on-chip integrated micro-heater. The studied n- and p-channel body-tied partially-depleted MOSFETs and CMOS inverter are embedded in a 5 μm-thick membrane fabricated by back-side MEMS micromachining using SOI technology. It has been noted that a pre-stabilization step after the harsh post-CMOS processing, through an in situ high-temperature annealing using the micro-heater, is mandatory in order to stabilize the MOSFETs characteristics. The electrical characteristics and performance of the on-membrane MOS components are discussed when heated up to 335 °C. This study supports the possibility of extending the potential of the micro-hotplate concept, under certain conditions, by embedding more electronic functionalities on the interface of on-membrane-based sensors leading to better sensing and actuation performances and a total area reduction, particularly for environmental or industrial applications.

  3. Electrodynamic stabilization conditions for high-temperature superconducting composites with different types of current-voltage characteristic nonlinearity

    Science.gov (United States)

    Arkharov, A. M.; Lavrov, N. A.; Romanovskii, V. R.

    2014-06-01

    The current instability is studied in high-temperature superconducting current-carrying elements with I- V characteristics described by power or exponential equations. Stability analysis of the macroscopic states is carried out in terms of a stationary zero-dimensional model. In linear temperature approximation criteria are derived that allow one to find the maximum allowable values of the induced current, induced electric field intensity, and overheating of the superconductor. A condition is formulated for the complete thermal stabilization of the superconducting composite with regard to the nonlinearity of its I- V characteristic. It is shown that both subcritical and supercritical stable states may arise. In the latter case, the current and electric field intensity are higher than the preset critical parameters of the superconductor. Conditions for these states depending on the properties of the matrix, superconductor's critical current, fill factor, and nonlinearity of the I- V characteristic are discussed. The obtained results considerably augment the class of allowable states for high-temperature superconductors: it is demonstrated that there exist stable resistive conditions from which superconductors cannot pass to the normal state even if the parameters of these conditions are supercritical.

  4. Yield stability and adaptability of maize hybrids based on GGE biplot analysis characteristics

    Directory of Open Access Journals (Sweden)

    Marcio Balestre

    2009-01-01

    Full Text Available The objective of this study was to evaluate stability and adaptability of the grain yield of commercial intervarietalmaize hybrids by the GGE (Genotype and Genotype by Environment Interaction biplot and AMMI (Additive Main Effects andMultiplicative Interaction analyses. Two intervarietal hybrids (BIO 2 and BIO4 were evaluated together with single, doubleand three-way cross hybrids. The performance of the intervarietal hybrid BIO 4 was superior to all double and three-waycross hybrids and outmatched the single-cross hybrids by 43%. In terms of stability, BIO 2 was more stable than BIO4, whichis desirable, but biological stability, which is not necessarily desirable, was also observed, since the yield was below theenvironmental mean. The graphical GGE biplot analysis was superior to the AMMI1 since a greater portion of the sum ofsquares of GE and G+GE was captured and the predictive accuracy was higher. On the other hand, the AMMI2 graphoutperformed the GGE biplot in predictive accuracy and explanation of G + GE and GE, although the difference in accuracywas smaller than between GGE2 and AMMI1.

  5. Effect of discontinuities characteristics on coal mine stability and sustainability:A rock fall prediction approach

    Institute of Scientific and Technical Information of China (English)

    Oraee Kazem; Oraee Nikzad; Goodarzi Arash; Khajehpour Parham

    2016-01-01

    Rock fall related accidents continue to occur in coal mines, although artificial support mechanisms have been used extensively. Roof stability is primarily determined in many underground mines by a limited number of methods that often resort to subjective criteria. It is argued in this paper that stability condi-tions of mine roof strata, as a key factor in sustainability in coal mines, must be determined by a survey which proactively investigates fundamental aspects of said mine. Failure of rock around the opening hap-pens as a result of both high rock stress conditions and the presence of structural discontinuities. The properties of such discontinuities affect the engineering behavior of rock masses causing wedges or blocks to fall from the roof or sliding out of the walls. A practical rule-based approach to assess the risk of a roof fall is proposed in the paper. The method is based on the analysis of structural data and the geometry and stability of wedges in underground coal mines. In this regard, an accident causing a huge collapse in a coal mine leading to 4 fatalities is illustrated by way of a case study. Horizontal and vertical profiles are prepared by geophysical methods to define the falling zone and its boundaries. The collapse is then modeled by the use of sophisticated computer programs in order to identify the causes of the accident.

  6. Investigation of moisture stability and PL characteristics of terpineol-passivated organic–inorganic hybrid perovskite

    Directory of Open Access Journals (Sweden)

    Xin Guo

    2016-09-01

    Full Text Available Abstract This work presents a novel method for preparing perovskite films using a simple processing technique. Perovskite paste was prepared by dispersing an equimolar mix of PbI2 and methyl ammonium iodide powders into terpineol with stirring. From these precursors, perovskite films were fabricated using doctor blading and drying for 24 h at room temperature. The prepared films were then placed into relative humidity (RH levels of 30, 50, and 70 % to test the moisture stability. The crystal structure, phases, and morphology were investigated with XRD and SEM/EDX. These samples exhibited good stability against long time exposure to moisture for 70 days. The XRD results showed that samples stored at RH 70 % contained only a small amount of hydrate compound after 70 days storage, while in the sample stored at RH 50 %, the formation of PbI2 was observed. The sample at RH 30 % manifested almost no change when stored for the same storage period. We attribute the enhanced moisture stability, compared with the spin-coated samples, to a passivated surface of the perovskite film by terpineol which exhibits a hydrophobic moiety. Time-resolved photoluminescence measurements show that the passivation of surface defect states by the formation of either PbI2 or hydrated compound leads to prolonged charge carrier recombination times. Graphical Abstract

  7. A longitudinal ecological study of the influences of political, economic, and health services characteristics on under-five mortality in less-developed countries.

    Science.gov (United States)

    Chuang, Ying-Chih; Sung, Pei-Wei; Chao, Hsing Jasmine; Bai, Chyi-Huey; Chang, Chia-Jung

    2013-09-01

    This study used a longitudinal dataset and lagged dependent-variable panel regression models to examine whether political and economic characteristics directly predict under-5-year mortality rates (U5MR), and moderate the effects of health services and environment on U5MR. We used a sample of 46 less-developed countries from 1980 to 2009. Our results showed that the effects of political and economic characteristics on U5MR varied by non-sub-Saharan and sub-Saharan countries. After controlling for baseline U5MR and other socioeconomic variables, while foreign investment and health services were negatively associated U5MR, democracy was positively associated with U5MR in nonsub-Saharan countries. In contrast, debt was positively associated with and democracy and foreign investment were negatively associated with U5MR in sub-Saharan countries. The interaction analyses indicated that for sub-Saharan countries, the effects of health services on U5MR only existed for countries with low foreign investment.

  8. Contactable Non-responders Show Different Characteristics Compared to Lost to Follow-Up Participants: Insights from an Australian Longitudinal Birth Cohort Study.

    Science.gov (United States)

    Ng, Shu-Kay; Scott, Rani; Scuffham, Paul A

    2016-07-01

    Objective This research aims to identify predictors of attrition in a longitudinal birth cohort study in Australia and assess differences in baseline characteristics and responses in subsequent follow-up phases between contactable non-responders and uncontactable non-responders deemed "lost to follow-up (LTF)". Methods 3368 women recruited from three public hospitals in Southeast Queensland and Northern New South Wales during antenatal visits in 2006-2011 completed a baseline questionnaire to elicit information on multiple domains of exposures. A follow-up questionnaire was posted to each participant at 1 year after birth to obtain mother's and child's health and development information. Multivariate logistic regression was used to model the association between exposures and respondents' status at 1 year. The effect of an inverse-probability-weighting method to adjust for non-response was studied. Results Overall attrition at 1-year was 35.4 %; major types of attrition were "contactable non-response" (27.6 %) and "LTF" (6.7 %). These two attrition types showed different responses at the 3-year follow-up and involved different predictors. Besides shared predictors (first language not English, higher risk of psychological distress, had smoked during pregnancy, higher levels of family conflict), distinguishable predictors of contactable non-responders were younger age, having moved home in the past year and having children under 16 in the household. Attrition rates increased substantially from 20 % in 2006 to 54 % in 2011. Conclusions This observed trend of increased attrition rates raises concern about the use of traditional techniques, such as "paper-based" questionnaires, in longitudinal cohort studies. The supplementary use of electronic communications, such as online survey tools and smart-device applications, could provide a better alternative.

  9. The Effects of Bacterial Inoculants on the Fermentation, Aerobic Stability and Rumen Degradability Characteristics of Wheat Silages

    OpenAIRE

    SUCU, Ekin; FİLYA, İsmail

    2006-01-01

    This study was carried out to determine the effects of lactic acid bacteria (LAB) inoculants on the fermentation, aerobic stability and in situ rumen degradability characteristics of wheat silages. Wheat was harvested at the early dough stage. Inoculant-1188 (Pioneer®, USA) and Sil-All (Alltech, UK) were used as LAB inoculants. Inoculants were applied to silages at 1.5 x 106 cfu/g levels. Wheat material was ensiled in 1.5-l special anaerobic jars, equipped with a lid enabling gas release on...

  10. Temporal Stability of the Human Skin Microbiome.

    Science.gov (United States)

    Oh, Julia; Byrd, Allyson L; Park, Morgan; Kong, Heidi H; Segre, Julia A

    2016-05-05

    Biogeography and individuality shape the structural and functional composition of the human skin microbiome. To explore these factors' contribution to skin microbial community stability, we generated metagenomic sequence data from longitudinal samples collected over months and years. Analyzing these samples using a multi-kingdom, reference-based approach, we found that despite the skin's exposure to the external environment, its bacterial, fungal, and viral communities were largely stable over time. Site, individuality, and phylogeny were all determinants of stability. Foot sites exhibited the most variability; individuals differed in stability; and transience was a particular characteristic of eukaryotic viruses, which showed little site-specificity in colonization. Strain and single-nucleotide variant-level analysis showed that individuals maintain, rather than reacquire, prevalent microbes from the environment. Longitudinal stability of skin microbial communities generates hypotheses about colonization resistance and empowers clinical studies exploring alterations observed in disease states.

  11. Lesion stability characteristics outperform degree of stenosis in predicting outcomes following stenting for symptomatic intracranial atherosclerosis.

    Science.gov (United States)

    Alexander, M D; Cooke, D L; Meyers, P M; Amans, M R; Dowd, C F; Halbach, V V; Higashida, R T; Hetts, S W

    2016-01-01

    Intracranial atherosclerotic disease (ICAD) causes substantial morbidity and mortality. Treatment decisions have most commonly been driven by the degree of luminal stenosis. This study compares ICAD lesion stability features with percentage stenosis for associations with adverse outcomes following treatment with stents. Retrospective analysis was performed of prospectively maintained procedure logs. Lesions were classified by symptom type as hypoperfusion, non-hypoperfusion, or indeterminate, and pretreatment asymptomatic intervals were noted. Hypoperfusion lesions and indeterminate or non-hypoperfusion lesions with ≥14 days of asymptomatic interval were classified as stable. Percentage stenosis was calculated and compared against these other symptom features for value in predicting technical complication, ischemic stroke, disability, or death at 90 days and 2 years using univariate and multivariate analysis. 130 lesions were treated in 124 patients. The only statistically significant percent stenosis finding was lesions with 60-99% stenosis were less likely to have technical complications. In univariate analysis, stroke at 2 years was less common with hypoperfusion and stable lesions. In multivariate analysis, only hypoperfusion status was associated with lower stroke rates at 2 years. Lesion stability features, particularly non-hypoperfusion symptomatology, outperform percentage stenosis in predicting outcomes following treatment of ICAD with stents. Further examination is needed to better classify the natural history of ICAD and more precisely classify lesion stability. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  12. River Embankment and Bank Failure: A Study on Geotechnical Characteristics and Stability Analysis

    Directory of Open Access Journals (Sweden)

    M. B. Hossain

    2011-01-01

    Full Text Available Problem statement: Embankment failure and riverbank erosion are common problem in Bangladesh. Almost every year earthen embankments and riverbanks are facing problems like erosion, breaching or retirements. Among many reasons the major causes are considered due to the use of geotechnically unstable materials, improper method of construction, seepage and sliding. In this study the problem is considered geotechnical point of view where the geotechnical properties of failed Jamuna river embankment material and Padma riverbank material were investigated. Moreover, stability analysis technique of embankment has been reviewed through a case study of Manu river embankement. Approach: Sample materials were collected during field investigation and tested at laboratory according to Japanese Industrial Standard (JIS. Limit equilibrium stability analysis and steady state seepage analysis was conducted for Manu river embankment to review the existing design procedure of embankment. Results: Study results reveal that the soil of Jamuna river embankment is not well graded sand and the permeability is found minimum of 1.29×10-5 cm sec−1 (at w = 24% which increases rapidly in submerge condition. The maximum strength is found 51.8 kN m−2 which is not preferable as embankment material. Moreover, the slope is not well protected that makes the embankment vulnerable to erosion. In contrast, the soil of Padma riverbank contains mostly sand with 25% clay content. Both permeability and strength of bank material decrease rapidly with the increase of water content. Nevertheless, tension crack and toe erosion also accelerate the mass failure mechanism of riverbank. From case study the Factor of Safety (FS is found overestimated of about 22-24% in stability analysis of embankment in usual practice. Conclusion: Embankment soil needs to be improved geotechnically to minimize mass failure. Geo-bags, cement composites with reinforcement could be used for

  13. Stability Characteristics of "Aerobic" Acetyl-CoA Synthetase of Yeast

    Science.gov (United States)

    Satyanarayana, T.; Klein, Harold P.

    1976-01-01

    During the purification of the "aerobic" acetyl-CoA synthetase (ACS) of Saccharomyces cerevisiae, strain LK2Gl2, it was noted that stronge at 4 C resulted in the loss of enzyme activity within 24 hr. Similar losses were observed during column chromatography. Addition of boiled extracts from either aerobic or anerobic cells completely prevents this. The stabilizing factor (SF) in these extracts is non-dialyzable and organic in nature. SF is excluded on G-25 and G-50 Sephadex columns and is slightly retarded on G-75 columns. On G-100 columns, SF elutes as a peak exactly coincident with that of cytochrome c, indicating a molecular weight of 13,000. SF activity was not destroyed by Pronase treatment, was adsorbed onto Norite, and absorbed in the UV with a single maximum at 260 nm. The action of SF could be replaced by a number of nucleotides. At 0.01 M, the order of effectiveness was: ATP>ADP>AMP>GTP>CTP>/=UTP>XTP. Even at 2 x 10(exp -4) M, ATP and ADP, but not AMP, cyclic AMP, adenosine or adenine, were effective in stabilizing this ACS. The mechanism of stabilization by ATP and AMP appears to be the same, since AMP competitively inhibited the ACS with respect to ATP in in vitro assays, while ADP gave a mixed type of inhibition, thus indicating a different mechanism. ACS from nonaerobic cells is also unstable in the absence of SF but, unlike aerobic ACS, is not affected by ATP or other nucleotides.

  14. Spatiotemporal characteristics of atrial fibrillation electrograms: A novel marker for arrhythmia stability and termination.

    Science.gov (United States)

    Thanigaimani, Shivshankar; Brooks, Anthony G; Kuklik, Pawel; Twomey, Darragh J; Franklin, Samantha; Noschka, Erik; Chapman, Darius; Pathak, Rajeev K; Mahajan, Rajiv; Sanders, Prashanthan; Lau, Dennis H

    2017-02-01

    Sequentially mapped complex fractionated atrial electrograms (CFAE) and dominant frequency (DF) sites have been targeted during catheter ablation for atrial fibrillation (AF). However, these strategies have yielded variable success and have not been shown to correlate consistently with AF dynamics. Here, we evaluated whether the spatiotemporal stability of CFAE and DF may be a better marker of AF sustenance and termination. Eighteen sheep with 12 weeks of "one-kidney, one-clip" hypertension underwent open-chest studies. A total of 42 self-terminating (28-100 s) and 6 sustained (>15 min) AF episodes were mapped using a custom epicardial plaque and analyzed in 4-s epochs for CFAE, using the NavX CFE-m algorithm, and DF, using a Fast Fourier Transform. The spatiotemporal stability index (STSI) was calculated using the intraclass correlation coefficient of consecutive AF epochs. A total of 67,733 AF epochs were analyzed. During AF initiation, mean CFE-m and the STSI of CFE-m/DF were similar between sustained and self-terminating episodes, although median DF was higher in sustained AF (p=0.001). During sustained AF, the STSI of CFE-m increased significantly (p=0.02), whereas mean CFE-m (p=0.5), median DF (p=0.07), and the STSI of DF remained unchanged (p=0.5). Prior to AF termination, the STSI of CFE-m was significantly lower (pCFE-m (p=0.14) or the STSI of DF (p=0.06). Spatiotemporal stabilization of CFAE favors AF sustenance and its destabilization heralds AF termination. The STSI of CFE-m is more representative of AF dynamics than are the STSI of DF, sequential mean CFE-m, or median DF.

  15. Crystallographic Characteristics of Grain Boundaries in Dense Yttria-Stabilized Zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Lam Helmick; Shen J. Dillon; Kirk Gerdes; Randall Gemmen; Gregory S. Rohrer; Sridhar Seetharaman; Paul A. Salvador

    2010-04-01

    Grain-boundary plane, misorientation angle, grain size, and grain-boundary energy distributions were quantified using electron backscatter diffraction data for dense polycrystalline yttria-stabilized zirconia, to understand interfacial crystallography in solid oxide fuel cells. Tape-cast samples were sintered at 14501C for 4 h and annealed for at least 100 h between 8001C and 16501C. Distributions obtained from both three-dimensional (3D) reconstructions and stereological analyses of 2D sections demonstrated that the (100) boundary planes {(111)} have relative areas larger {smaller} than expected in a random distribution, and that the boundary plane distribution is inversely correlated to the boundary energy distribution.

  16. Oxygen stabilization induced enhancement in superconducting characteristics of high-Tc oxides

    Science.gov (United States)

    Wu, M. K.; Chen, J. T.; Huang, C. Y.

    1991-01-01

    In an attempt to enhance the electrical and mechanical properties of the high temperature superconducting oxides, high T(sub c) composites were prepared composed of the 123 compounds and AgO. The presence of extra oxygen due to the decomposition of AgO at high temperature is found to stabilize the superconducting 123 phase. Ag is found to serve as clean flux for grain growth and precipitates as pinning center. Consequently, almost two orders of magnitude enhancement in critical current densities were also observed in these composites. In addition, these composites also show much improvement in workability and shape formation. On the other hand, proper oxygen treatment of Y5Ba6Cu11Oy was found to possibly stabilize superconducting phase with T(sub c) near 250 K. I-V, ac susceptibility, and electrical resistivity measurements indicate the existence of this ultra high T(sub c) phase in this compound. Detailed structure, microstructure, electrical, magnetic and thermal studies of the superconducting composites and the ultra high T(sub c) compound are presented and discussed.

  17. Affect consciousness and eating disorders. Short term stability and subgroup characteristics.

    Science.gov (United States)

    Lech, Börje; Holmqvist, Rolf; Andersson, Gerhard

    2012-01-01

    The aim of the study was to analyse differences in observer rated affect consciousness (AC) between subgroups of patients diagnosed with eating disorders (N = 44; 30 with anorexia nervosa and 14 with bulimia nervosa), and a non-clinical group (N = 40). Another aim was to study the short-term stability of AC over 10-11 weeks of treatment and its relation to self-reported eating pathology and general psychopathology. A moderate short-term stability of AC was found but the levels were not correlated with eating pathology or psychopathology. No differences between the two diagnostic categories were found, but the eating disorder group as whole had significantly lower AC compared with a non-eating disorder reference group. AC seems to be a moderately stable ability that differentiates patients diagnosed with eating disorders from a non-clinical population. However, AC is not related to symptoms of eating disorder or general psychiatric symptoms in this group of patients. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.

  18. Polyacrylamide Gel-Entrapped Fungal Manganese Peroxidase with Enhanced Catalytic, Stability and Reusability Characteristics.

    Science.gov (United States)

    Bilal, Muhammad; Asgher, Muhammad; Iqbal, Hafiz M N

    2016-07-19

    In the present study, polyacrylamide gel (PAG) was utilized as bolster material for the immobilization of in-house extracted and partially purified manganese peroxidase (MnP) through entrapment technique. The entrapment technique impelled incredibly compelling MnP immobilization (87.3±3.3%) and conferred remarkable stability to the enzyme (37.2±2.4%) following two months of storage at 4°C. The PAG-assisted immobilization expanded the reaction time of MnP after 10 min of response when contrasted with a partially purified free MnP counterpart, which demonstrated the highest activity after 5.0 min. Following PAG-assisted immobilization, an improvement in the optimal temperature and a chemical (an alkaline) shift in the pH optima of MnP were recorded. Moreover, a significant enhancement in the thermo-stability was also observed after immobilization. After 72 h, PAG-entrapped-MnP exhibited 41.2% residual activity at 50°C, whereas the free counterpart lost its activity completely under the same conditions. Furthermore, the PAG-entrapped-MnP also showed an excellent recycling efficiency and retained more than 50% of its initial activity after five consecutive reaction cycles. In conclusion, owing to the economic feasibility, carrier-supported MnP may be a promising candidate for various applications in different sectors of the modern world.

  19. Performance characteristics and output power stability of a multichannel fibre laser

    Science.gov (United States)

    Kuzmenkov, A. I.; Lukinykh, S. N.; Nanii, O. E.; Odintsov, A. I.; Smirnov, A. P.; Fedoseev, A. I.; Treshchikov, V. N.

    2016-09-01

    The effect of the density and number of spectral channels on the output power stability in a multichannel cw laser has been studied theoretically and experimentally. In our calculations, we used a model in which the interaction between channels due to gain medium saturation was determined by channel frequency spacingdependent cross-saturation coefficients. The key features of lasing have been analysed and illustrated by the examples of three-, fiveand nine-channel lasers. It has been shown that, at a given excess of the pump power over threshold, the channel powers can be equalised by introducing additional losses into the highest power channels. At a sufficiently high channel density, raising the pump power then leads to termination of lasing in the even channels. As the number of channels increases, the laser system retains its stability, but the time needed for the transition to a steady state increases sharply. In our experiments, we used an erbium-doped fibre laser whose design ensured independent control over the powers of up to 40 spectral channels anchored on the telecommunication frequency grid. Our experimental data are in qualitative agreement with the calculation results. In particular, a long-term relative instability less than 3 dB was only observed at a number of channels less than seven and channel frequency spacings above 400 GHz. Instability was shown to increase with an increase in the number and density of channels.

  20. Sodium alginate stabilized silver nanoparticles-silica nanohybrid and their antibacterial characteristics.

    Science.gov (United States)

    Pandey, Sadanand; Ramontja, James

    2016-12-01

    Due to the problem of resistance of many infectious agents to the usual treatments, this study addresses the ways of obtaining and using new sodium alginate stabilized-silver/mesoporous silica (Na-Alg-s-AgNPs@SiO2) nanohybrid as antimicrobial agents. Capping AgNPs with a shell of mesoporous SiO2 is a system to build the increase biocompatibility of AgNPs. In this work, we report a simple and green way to deal with setting up a uniform sodium alginate-stabilized silver nanoparticles embedded mesoporous silica (Na-Alg-s-AgNPs@SiO2 nanohybrid). The synthesized nanocomposite was characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra, and ultraviolet-visible (UV-vis) absorption spectra, which exhibited that AgNPs with average of size of ∼7nm were consistently and compactly deposited in the nanocomposite. The nanohybrid demonstrated excellent antibacterial activity against both Gram negative (-ve) and Gram positive (+ve) bacteria. Thus, the developed Na-Alg-s-AgNPs@SiO2 nanohybrid has a potential to be used for various antibacterial applications in biotechnology and biomedical fields.

  1. Influence of characteristics of stabilized zirconia electrolyte on performance of cermet supported tubular SOFCs

    Institute of Scientific and Technical Information of China (English)

    LI Changjiu; LI Chengxin; XING Yazhe; XIE Yingxin; LONG Huiguo

    2006-01-01

    Ni-Al2O3 cermet supported tubular SOFC was fabricated by thermal spraying. Flame-sprayed Al2O3-Ni cermet coating plays dual roles of a support tube and an anode current collector. 4.5mol.% yttria-stabilized zirconia (YSZ) and 10mol.% scandia-stabilized zirconia (ScSZ) coatings were deposited by atmospheric plasma spraying (APS) as the electrolyte in present study. The electrical conductivity of electrolyte was measured using DC method. The post treatment was employed using nitrate solution infiltration to densify APS electrolyte layer for improvement of gas permeability. The electrical conductivity of electrolyte and the performance of single cell were investigated to optimize SOFC performance. The electrical conductivity of the as-sprayed YSZ and ScSZ coating is about 0.03 and 0.07 S·cm-1 at 1000 ℃, respectively. The ohmic polarization significantly influences the performance of SOFC. The maximum output power density at 1000 ℃ increases from 0.47 to 0.76 W·cm-2 as the YSZ electrolyte thickness reduces from 100 μm to 40 μm. Using APS ScSZ coating of about 40 μm as the electrolyte, the test cell presents a maximum power output density of over 0.89 W·m-2 at 1000 ℃.

  2. Clinical characteristics and evaluation of LDL-cholesterol treatment of the Spanish Familial Hypercholesterolemia Longitudinal Cohort Study (SAFEHEART

    Directory of Open Access Journals (Sweden)

    Piedecausa Mar

    2011-06-01

    Full Text Available Abstract Aim Familial hypercholesterolemia (FH patients are at high risk for premature coronary heart disease (CHD. Despite the use of statins, most patients do not achieve an optimal LDL-cholesterol goal. The aims of this study are to describe baseline characteristics and to evaluate Lipid Lowering Therapy (LLT in FH patients recruited in SAFEHEART. Methods and Results A cross-sectional analysis of cases recruited in the Spanish FH cohort at inclusion was performed. Demographic, lifestyle, medical and therapeutic data were collected by specific surveys. Blood samples for lipid profile and DNA were obtained. Genetic test for FH was performed through DNA-microarray. Data from 1852 subjects (47.5% males over 19 years old were analyzed: 1262 (68.1%, mean age 45.6 years had genetic diagnosis of FH and 590 (31.9%, mean age 41.3 years were non-FH. Cardiovascular disease was present in 14% of FH and in 3.2% of non-FH subjects (P Conclusion Although most of this high risk population is receiving LLT, prevalence of cardiovascular disease and LDL-c levels are still high and far from the optimum LDL-c therapeutic goal. However, LDL-c levels could be reduced by using more intensive LLT such as combined therapy with maximum statin dose and ezetimibe.

  3. 基于Nyquist稳定判据的磨合过程稳定性研究%Stability Characteristics of Running -in Process Based on Nyquist Stability Criterion

    Institute of Scientific and Technical Information of China (English)

    李国宾; 黄业华; 魏海军

    2012-01-01

    在销-盘摩擦磨损试验机上进行了船用柴油机缸套-活塞环摩擦配副磨合磨损试验,采集磨合过程中摩擦振动信号,应用Nyquist稳定判据,通过摩擦振动Nyquist曲线对磨合系统稳定性进行分析.结果表明:摩擦振动Nyquist曲线反映了磨合系统稳定性变化.当摩擦副磨合开始时(0~10 min),摩擦振动Nyquist曲线不包围(-1,j0)点,磨合系统处于稳定磨损阶段;在摩擦副磨合进行过程中(10~40 min),摩擦振动Nyquist曲线包围(-1,j0),磨合系统处于不稳定磨损阶段;当摩擦副达到磨合时(40 min后),摩擦振动Nyquist曲线不包围(-1,j0),磨合系统处于稳定磨损阶段.因此,磨合系统的特性可揭示磨合过程稳定性变化规律.%The running - in and wear tests of a piston ring against a cylinder available from marine diesel engine are conducted on a pin - on - disc tester. The friction vibration signals from the running - in process are collected. The nyquist stability criterion is used for analyzing the stability characteristics of the running - in system through the nyquist curve of the friction vibration. It is shown that the stability of the running - in system can be characterized by he nyquist curve of the friction vibration. When the friction pairs start running (0 ~ 10 min) , the point ( - 1, j0) is not surrounded by the nyquist curve of the friction vibration, the running - in system runs under the stable wear state. When the friction pairs run during the running - in and wear process ( 10 -40 min) , the point ( - 1, j0) is surrounded by the nyquist curve of the friction vibration, the running - in system runs under the unstable wear state. When the friction pairs achieve the running - in ( after 40 min) , the point ( - 1, j0) is not surrounded by the nyquist curve of the friction vibration, the running - in system runs under the stable wear state. Therefore the stability characteristics of

  4. CHARACTERISTICS, STABILITY AND ANTIMICROBIAL ACTIVITY OF LACTIC ACID BACTERIA (Leuconostoc sp ISOLATED FROM BROILER’S CAECUM DURING STORAGE

    Directory of Open Access Journals (Sweden)

    S. Sumarsih

    2014-10-01

    Full Text Available Lactic acid bacteria (LAB is one of the natural microbe which widely used as fermentation agents.The purpose of this study was to examine the characteristics, stability and antimicrobial properties oflactic acid bacteria (Leuconostoc sp isolated from broiler’s caecum during storage. This research wasconducted by the Complete Randomized Design with 4 treatments (time of storage: 0, 2, 4 dan 6 weekswith 12 replications. Parameters observed were total number and stability properties of Leuconostoc spisolate which known as lactic acid bacteria. The results obtained total number of Leuconostoc sp isolatewere significantly (P<0.05 decreased from 8 x 107 to 1 x 103 Colony Forming Unit (CFU/mL duringstorage. Stability properties of Leuconostoc sp isolate were not affected by the time of storage.Antimicrobial activity of Leuconostoc sp were significantly (P<0.05 decreased from 9.94 to 8.68, 7.23and 6.14 mm during storage at 2, 4 and 6 weeks.

  5. The Analytic Solutions to the Task of Maintaining the Specified Characteristics Stability in Aircraft Flight Control System Reconfiguration

    Directory of Open Access Journals (Sweden)

    Efanov Dmitry

    2017-01-01

    Full Text Available The paper sets out the conceptual issues of methods of analytical solution of the problem of defined aircraft stability characteristics conservation during flight control system reconfiguration under actuating subsystem failure. It is shown that the use of the reconfiguration technique with analytic set of stabilizing control laws synthesized by the decomposition method taking into account the cross-linking between the control channels allows to fully compensate the effects of failures of the actuating subsystem in each of the control channels under the conditions of complete controllability of aircraft as a dynamic system. It thus makes it possible to reconfigure the flight control system that always ensures the stability of the motion of the aircraft with a precisely prescribed poles. During study of failures in the form of a gradual reduction of the effectiveness of control surfaces it found that the synthesized analytical control law is a corresponding automatic increase feedback gain serviceable channel actuating subsystem, as well as the reallocation of control signals between the drives within the existing cross-connections between the control channels. Some of the solutions obtained by reconfiguring the control laws are not satisfactory, because of significantly limited possibility of maneuvering.

  6. Soy protein isolate added to vacuum-packaged chorizos: effect on drip loss, quality characteristics and stability during refrigerated storage.

    Science.gov (United States)

    Porcella, M I; Sánchez, G; Vaudagna, S R; Zanelli, M L; Descalzo, A M; Meichtri, L H; Gallinger, M M; Lasta, J A

    2001-04-01

    Chorizo is a raw sausage, which is manufactured with beef, pork meat and pork fat, additives and spices. In Argentina, the expenditure of chorizo is through butchery and supermarkets where the product can be found packaged in both polyethylene films and vacuum sealed pouches. In the latter type of packaging an appearance problem has been detected in relation to drip loss. The aim of the work was to solve such problem through the incorporation of soy protein isolate (SPI). The sensory, microbiological and chemical stability of the product and its drip loss during a storage period of 14 days were studied. By adding a 2.5% SPI, the drip loss was prevented without introducing any change in the flavour, aroma and juiciness characteristics of the product. These sensory attributes were kept stable during the storage period studied. Chemical composition, oxidative and microbiological stability were not affected by the addition of SPI during the storage period, being similar for added and non-added SPI samples. Finally, SPI can be used in chorizos to improve their overall appearance during refrigerated storage while the product quality characteristics are not altered.

  7. Comparison of meat quality characteristics and oxidative stability between conventional and free-range chickens.

    Science.gov (United States)

    Funaro, A; Cardenia, V; Petracci, M; Rimini, S; Rodriguez-Estrada, M T; Cavani, C

    2014-06-01

    The aim of this research was to evaluate quality traits and oxidative stability of meat products from free-range (FR) and conventionally (C) raised chickens as they actually reach consumers in the Italian retail market. Free-range female and male chickens (n = 1,500 + 1,500), medium growing ISA strain, were raised under commercial conditions for 56 (1.8 kg of live weight) and 70 d (3.1 kg of live weight), respectively; C female and male birds (n = 5,000 + 5,000) were a fast growing hybrid (Ross 708) and were separately raised for 39 (1.9 kg of live weight) and 50 d (3.1 kg of live weight), respectively. A total of 96 chickens (equally divided by production system and sex) were slaughtered in 2 separate sessions to obtain the main 2 commercial categories (rotisserie and cut-up, respectively). After slaughtering, 12 carcasses of each treatment group were randomly selected and used to assess quality properties, chemical composition, and oxidation stability of breast and leg meat. The C birds had dramatic higher carcass and breast meat yield, whereas FR had higher wing and leg yields. The FR birds exhibited higher water holding capacity in both breast and leg meat. Although shear force did not differ in breast meat, legs from FR birds were tougher. Fatty acid composition of FR breast and thigh meat of both categories were characterized by a higher polyunsaturated fatty acid n-6-/n-3 ratio. In general, a low lipid oxidation level (peroxide value < 1.3 mEq O2/kg of lipid and TBA reactive substances < 0.2 mg malondialdehyde/kg of sample) was found in breast and legs, regardless of the commercial category. However, the C system significantly increased peroxide value in rotisserie thigh meat, whereas FR led to a significantly higher TBA reactive substances in breast meat. Our results demonstrated that free range can modify the properties of chicken meat and also highlighted the importance of the bird genetic background to select nutritional strategies to improve meat

  8. Stabilization of gas-filled surge arrester’s characteristics by use of ionizing radiation

    Directory of Open Access Journals (Sweden)

    Brajović Dragan V.

    2012-01-01

    Full Text Available This paper investigates the stabilization of electrical discharges in gases by means of external ionizing radiation. Discharges in a gas-filled surge arrester model were studied in both passive and active regimes of the device. An originally developed model of the gas-filled surge arrester was used. Gas pressure and the interelectrode gap were the variable parameters in our measurements. Applied radiation types included α-particles, γ-rays, X-rays, and neutrons. Measurements were performed under highly controlled laboratory conditions. The combined measurement uncertainty of the applied procedure was estimated as being under the 5% level. The results obtained are followed by a theoretical explanation. The crucial result is the conclusion that ionizing radiation does not necessarily degrade the gas-filled surge arrester’s functionality but that it, rather, improves it under certain conditions.

  9. Effect of fibrolytic enzymes on the fermentation characteristics, aerobic stability, and digestibility of bermudagrass silage.

    Science.gov (United States)

    Dean, D B; Adesogan, A T; Krueger, N; Littell, R C

    2005-03-01

    The aim of this study was to determine if the nutritive value and aerobic stability of bermudagrass (Cynodon dactylon) silage could be improved by addition of proprietary, exogenous cellulase/hemicellulase enzyme preparations at ensiling. A 5-wk regrowth of Tifton 85 bermudagrass was conserved without treatment (control) or after treatment with exogenous fibrolytic enzymes including Promote NET (Pr), Biocellulase X-20 (X20), Biocellulase A-20 (A20), and Enzyme CT. The respective enzymes were applied at half the recommended rate, the recommended rate, or twice the recommended rate corresponding to 0.65, 1.3, and 2.6 g/kg of DM, 7.3, 14.5, and 29 mg/kg of DM, at 7.3, 14.4, and 29 mg/kg of DM, and 89, 178, and 356 mg/kg of DM, for Pr, X20, A20, and CT, respectively. The enzymes were sprayed on the bermudagrass at ensiling (not added at feeding as suggested by the manufacturers) to test the objectives of the study. Six 1-kg replicates of chopped (5 cm) forage were ensiled for 145 d in 2.8-L mini silos. Three silos per treatment were used for chemical analysis and 3 for aerobic stability monitoring. The silage juice was analyzed for organic acids, pH, water-soluble carbohydrates (WSC), ammonia-N, and soluble N. Freeze-dried samples were analyzed for crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF). In vitro digestibility of DM (IVDMD), NDF (IVNDFD), and ADF (IVADFD) were determined after digesting the silages in buffered rumen fluid for 6 or 48 h in 2 ANKOM(II) Daisy Incubators. Compared with the other silages, those treated with Pr had lower DM losses, and lower pH and ammonia-N concentration than control silages. Residual WSC concentration was greater in Pr- and CT-treated silages than in control silages and greater in Pr-treated silages than CT-treated silages. Compared with control silages, NDF concentration was lower in silages treated with Pr, X20, and CT, and ADF concentration was lower in silages treated with Pr, X20, and A20

  10. Dew formation characteristics in a revegetation-stabilized desert ecosystem in Shapotou area, Northern China

    Science.gov (United States)

    Pan, Yan-xia; Wang, Xin-ping; Zhang, Ya-feng

    2010-06-01

    SummarySoil moisture in the upper layer plays an important role in arid desert ecosystems. Dew as an additional source of fresh water, may have a positive impact upon the ecosystems in arid and semi-arid zones. Measurements on dew formation amount and duration were carried out in the whole October of 2008 at different condensing surface types (bare dune sands, physical soil crusts and biological soil crusts) associated with different inter-space positions between plants, and at the area under plant canopy in a revegetation-stabilized arid desert ecosystem in Shapotou area, China. The results indicated that there was a positive linear correlation between dew amounts and relative humidity, while mean temperature was negatively linearly related to dew amounts and no significant relationship was found between dew amounts and wind speed. Clear and foggy mornings were characterized by higher dew amounts and longer dew duration, whereas less dew was recorded during cloudy and especially windy mornings. Crusts, especially the biological soil crusts, obtained significantly higher amounts of dew than that of bare moving sand dunes. It was more difficult for dew to condense under the canopy of the plants than on the bare sand dunes. At the first stage of ecological engineering projects, dew can renew the moisture losing through the evaporation of soil and transpiration of leaves, and thus can supply important source of water for xerophytic shrubs. The higher dew amount at the inter-space of re-vegetated plants is an important driving factor for the growth of microorganisms and spore plants, which further accelerate the formation of biological soil crusts and stabilization of moving sand dunes. The presence of biological soil crusts, in turn, helps to facilitate the formation of dew. Therefore, a mutual enhanced effect exists between dew and artificially revegetation ecosystems.

  11. Characteristics, composition and oxidative stability of Lannea microcarpa seed and seed oil.

    Science.gov (United States)

    Bazongo, Patrice; Bassolé, Imaël Henri Nestor; Nielsen, Søren; Hilou, Adama; Dicko, Mamoudou Hama; Shukla, Vijai K S

    2014-02-24

    The proximate composition of seeds and main physicochemical properties and thermal stability of oil extracted from Lannea microcarpa seeds were evaluated. The percentage composition of the seeds was: ash (3.11%), crude oil (64.90%), protein (21.14%), total carbohydrate (10.85%) and moisture (3.24%). Physicochemical properties of the oil were: refractive index, 1.473; melting point, 22.60°C; saponification value, 194.23 mg of KOH/g of oil; iodine value, 61.33 g of I2/100 g of oil; acid value, 1.21 mg of KOH/g of oil; peroxide value, 1.48 meq of O2/kg of oil and oxidative stability index, 43.20 h. Oleic (43.45%), palmitic (34.45%), linoleic (11.20%) and stearic (8.35%) acids were the most dominant fatty acids. Triacylglycerols with equivalent carbon number (ECN) 48 and ECN 46 were dominant (46.96% and 37.31%, respectively). The major triacylglycerol constituents were palmitoyl diolein (POO) (21.23%), followed by dipalmitoyl olein (POP) (16.47%), palmitoyl linoleyl olein (PLO) (12.03%), dipalmitoyl linolein (PLP) (10.85%) and dioleoyl linolein (LOO) (9.30%). The total polyphenol and tocopherol contents were 1.39 mg GAE g-1 DW and 578.56 ppm, respectively. γ-Tocopherol was the major tocopherol (437.23 ppm). These analytical results indicated that the L. microcarpa seed oil could be used as a frying oil and in the cosmetic industry.

  12. The Effect of Microbial Inoculants Applied at Ensiling on Sorghum Silage Characteristics and Aerobic Stability

    Institute of Scientific and Technical Information of China (English)

    GUAN Wu-tai; Ashbell G; Hen Y; Weinberg Z G

    2002-01-01

    Whole crop forage sorghum (Saccharatum) cultivar FS5 was harvested at the soft dough stage of maturity. The sorghum was chopped to approximately 2 cm pieces and ensiled under laboratory conditions in 1.5 L Weck glass jars. At ensiling, it was treated with two commercial microbial inoculants: inoculant A and inoculant B. The inoculants were applied at 2 × 105 colony forming units g- 1 DM. Silage with no additives served as a control. Three jars per treatment were opened on days 2, 4, 8, 15 and 60 post-ensiling to study fermentation dynamics. After 60 days of ensiling, the silages were analyzed and subjected to an aerobic stability test lasting 5 days. Results showed that both inoculants caused a more rapid rate of pH decline and a higher amount of lactic acid production. Silages treated with each inoculant produced a little more CO2 and resulted in more glucose loss as compared with the control. Addition of inoculants did not influence ( P > 0.05) the ash and crude protein contents, but tended to decrease the concentration of acetic acid (P < 0.05), butyric acid (P < 0.01) and propionic acid ( P < 0.01 ), and increase the lactic acid concentration ( P < 0.01 ). Silages treated with inoculant A possess the more DM loss, and the higher yeast counts upon aerobic exposure. Silage treated with inoculant B had the most DM (P < 0.05), lactic acid contents (P < 0.01 ), the least acetic acid content (P < 0.05). Inoculant B reduced the ADF (P < 0.01), ADL and NDF ( P < 0.05) contents. It was concluded that lactic bacteria inoculants may improve the fermentation but might impair the aerobic stability for sorghum ensilage.

  13. Characteristics, Composition and Oxidative Stability of Lannea microcarpa Seed and Seed Oil

    Directory of Open Access Journals (Sweden)

    Patrice Bazongo

    2014-02-01

    Full Text Available The proximate composition of seeds and main physicochemical properties and thermal stability of oil extracted from Lannea microcarpa seeds were evaluated. The percentage composition of the seeds was: ash (3.11%, crude oil (64.90%, protein (21.14%, total carbohydrate (10.85% and moisture (3.24%. Physicochemical properties of the oil were: refractive index, 1.473; melting point, 22.60°C; saponification value, 194.23 mg of KOH/g of oil; iodine value, 61.33 g of I2/100 g of oil; acid value, 1.21 mg of KOH/g of oil; peroxide value, 1.48 meq of O2/kg of oil and oxidative stability index, 43.20 h. Oleic (43.45%, palmitic (34.45%, linoleic (11.20% and stearic (8.35% acids were the most dominant fatty acids. Triacylglycerols with equivalent carbon number (ECN 48 and ECN 46 were dominant (46.96% and 37.31%, respectively. The major triacylglycerol constituents were palmitoyl diolein (POO (21.23%, followed by dipalmitoyl olein (POP (16.47%, palmitoyl linoleyl olein (PLO (12.03%, dipalmitoyl linolein (PLP (10.85% and dioleoyl linolein (LOO (9.30%. The total polyphenol and tocopherol contents were 1.39 mg GAE g−1 DW and 578.56 ppm, respectively. γ-Tocopherol was the major tocopherol (437.23 ppm. These analytical results indicated that the L. microcarpa seed oil could be used as a frying oil and in the cosmetic industry.

  14. Changes in the Game Characteristics of a Badminton Match: A Longitudinal Study through the Olympic Game Finals Analysis in Men’s Singles

    Directory of Open Access Journals (Sweden)

    Guillaume Laffaye, Michael Phomsoupha, Frédéric Dor

    2015-09-01

    Full Text Available The goal of this study was to analyze, through a longitudinal study, the Olympic Badminton Men’s singles finals from the Barcelona Games (1992 to the London Games (2012 to assess some changes of the Badminton game characteristics. Six Olympic finals have been analyzed based on the official video of the Olympic Games (OG through the temporal structure and with a notational approach. In total, 537 rallies and 5537 strokes have been analyzed. The results show a change in the game’s temporal structure: a significant difference in the rally time, rest time and number of shots per rally (all p<0.0001; 0.09 < η2 < 0.16. Moreover, the shot frequency shows a 34.0% increase (p<0.000001; η2 = 0.17, whereas the work density revealed a 58.2% decrease (from 78% to 30.8% as well as the effective playing time (-34.5% from 34.7±1.4% to 22.7±1.4%. This argues for an increase in the intensity of the game and a necessity for the player to use a longer resting time to recover. Lastly, the strokes distribution and the percentage of unforced and forced mistakes did not show any differences throughout the OG analysis, except for the use of the clear. This results impact on the way the training of Badminton players should be designed, especially in the temporal structure and intensity.

  15. Longitudinal associations of neighborhood socioeconomic characteristics and alcohol availability on drinking: Results from the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Brenner, Allison B; Borrell, Luisa N; Barrientos-Gutierrez, Tonatiuh; Diez Roux, Ana V

    2015-11-01

    Neighborhood socioeconomic characteristics and alcohol availability may affect alcohol consumption, but adequate longitudinal research to support these hypotheses does not exist. We used data from the Multi-Ethnic Study of Atherosclerosis (MESA) (N = 6163) to examine associations of changes in neighborhood socioeconomic status (SES) and alcohol outlet density, with current, weekly, and heavy daily alcohol consumption in hybrid effects models. We also examined whether these associations were moderated by gender, race/ethnicity, and income. Increases in neighborhood SES were associated with decreases in the probability of current alcohol use after adjustment for age, gender, race/ethnicity, individual SES, marital status and time since baseline [probability ratio (PR) per SD increase in neighborhood SES = 0.96, 95% confidence interval (CI) (0.96.0.99)]. Increases in liquor store densities were associated with increases in weekly alcohol consumption [ratio of weekly drinks per SD increase in outlet density = 1.07, 95% CI (1.01.1.05) for men, PR = 1.11, 95% CI (1.01.1.21) for women]. Relationships between current alcohol use and neighborhood SES and between weekly beer consumption and neighborhood SES were generally stronger among those with higher incomes. Neighborhood socioeconomic context and the availability of alcohol may be important for understanding patterns of alcohol use over time, and for targeting interventions and policies to reduce harmful alcohol use.

  16. Correlation between serum uric acid levels and clinical characteristics in patients with longitudinally extensive transverse myelitis A case-control study

    Institute of Scientific and Technical Information of China (English)

    Xiaofan You; Wei Qin; Jing Ye; Yonggang Hao; Wenhui Zhao; Wenli Hu

    2011-01-01

    Uric acid is reduced in demyelinating diseases, including multiple sclerosis and neuromyelitis optica (NMO).Longitudinally extensive transverse myelitis (LETM) is often an early manifestation of NMO.Whether uric acid levels are reduced at presentation of LETM remains unknown.The present study investigated serum uric acid levels by evaluating 35 patients with LETM, 64 with NMO, 62 with multiple sclerosis, 63 Mth other neurological diseases and 65 healthy controls.In addition, we tested the correlation between serum uric acid and the clinical characteristics of LETM.All patients were in the acute phase, defined as less than 1 month from onset or relapse.The results revealed that serum uric acid levels in LETM were significantly lower than in multiple sclerosis, other neurological diseases and healthy controls, but no difference was found between LETM and NMO.A negative correlation between uric acid levels and Expanded Disability Status Scale scores was found in LETM patients (r=-0.545, P < 0.05).The results suggest that uric acid levels are reduced in patients with LETM, raising the possibility that lower uric acid levels are an indicator of disease disability.Moreover, reduced uric acid levels may be a risk factor in NMO.

  17. Health behaviors and family characteristics in early childhood influence caries development. A longitudinal study based on data from MoBa

    Directory of Open Access Journals (Sweden)

    Tove I. Wigen

    2014-12-01

    Full Text Available Background: Lifestyle diseases including dental caries are partly preventable, and associated with health behavior. Establishing favorable health behavior is one main challenge both in general and dental health services. The purpose of this paper was to focus on cross-disciplinary research that has the potential to prevent development of both dental caries and other lifestyle diseases. More specifically the aim was to study how family characteristics and health behavior in pregnancy and early childhood influence caries development in preschool children.Material and methods: Data from dental examination of 5 year old children in the public dental services was linked to data from MoBa. In total, 1348 children were followed from pregnancy to 5 years of age. The data has provided opportunity to follow longitudinally the development of oral health behavior in early childhood in a large sample, and to study associations between caries development during preschool age and information in the MoBa database.Results: Results from the studies showed that tooth brushing frequency established at 1.5 year of age was stable through preschool age. Caries development in preschool age was related to child and maternal risk behavior in early childhood and to characteristics of risk families.Conclusion: Cross-disciplinary research using MoBa data has given new knowledge on dental caries development in early childhood in Norway. This knowledge can be used in clinical practice both in general and dental health services to improve preventive efforts towards early childhood caries and other lifestyle diseases.

  18. Longitudinal Patterns of Stability and Change in Tenacious Goal Pursuit and Flexible Goal Adjustment among Older People over a 9-Year Period

    National Research Council Canada - National Science Library

    Guillaume Martinent; Nathalie Bailly; Claude Ferrand; Kamel Gana; Caroline Giraudeau; Michèle Joulain

    2017-01-01

    ... from distinct TGP and FGA trajectories differed in indicators of well-being and depression. Latent class growth analysis was used in a five-wave longitudinal design among an older population of 747 participants over 65 years. Results highlight (1...

  19. Adolescents of the US National Longitudinal Lesbian Family Study: the impact of having a known or an unknown donor on the stability of psychological adjustment

    NARCIS (Netherlands)

    Bos, H.M.W.; Gartrell, N.K.

    2011-01-01

    Background: The current study is based on the US National Longitudinal Lesbian Family Study (NLLFS), which was designed to document the development of the first generation of lesbian families with children conceived through donor insemination. Data were collected in five waves, first at insemination

  20. Influence of grain boundary characteristics on thermal stability in nanotwinned copper

    Science.gov (United States)

    Niu, Rongmei; Han, Ke; Su, Yi-Feng; Besara, Tiglet; Siegrist, Theo M.; Zuo, Xiaowei

    2016-08-01

    High density grain boundaries provide high strength, but may introduce undesirable features, such as high Fermi levels and instability. We investigated the kinetics of recovery and recrystallization of Cu that was manufactured to include both nanotwins (NT) and high-angle columnar boundaries. We used the isothermal Johnson-Mehl-Avrami-Kolmogorov (JMAK) model to estimate activation energy values for recovery and recrystallization and compared those to values derived using the non-isothermal Kissinger equation. The JMAK model hinges on an exponent that expresses the growth mechanism of a material. The exponent for this Cu was close to 0.5, indicating low-dimensional microstructure evolution, which is associated with anisotropic twin coarsening, heterogeneous recrystallization, and high stability. Since this Cu was of high purity, there was a negligible impurity-drag-effect on boundaries. The twin coarsening and heterogeneous recrystallization resulted from migration of high-angle columnar boundaries with their triple junctions in one direction, assisted by the presence of high concentration vacancies at boundaries. Analyses performed by electron energy loss spectroscopy of atomic columns at twin boundaries (TBs) and in the interior showed similar plasma peak shapes and L3 edge positions. This implies that values for conductivity and Fermi level are equal for atoms at TBs and in the interior.

  1. Catalase-only nanoparticles prepared by shear alone: Characteristics, activity and stability evaluation.

    Science.gov (United States)

    Huang, Xiao-Nan; Du, Xin-Ying; Xing, Jin-Feng; Ge, Zhi-Qiang

    2016-09-01

    Catalase is a promising therapeutic enzyme; however, it carries risks of inactivation and rapid degradation when it is used in practical bioprocess, such as delivery in vivo. To overcome the issue, we made catalase-only nanoparticles using shear stress alone at a moderate shear rate of 217s(-1) in a coaxial cylinder flow cell. Properties of nanoparticles, including particle size, polydispersity index and zeta potential, were characterized. The conformational changes of pre- and post-sheared catalase were determined using spectroscopy techniques. The results indicated that the conformational changes of catalase and reduction in α-helical content caused by shear alone were less significant than that by desolvation method. Catalase-only nanoparticles prepared by single shear retained over 90% of its initial activity when compared with the native catalase. Catalase nanoparticles lost only 20% of the activity when stored in phosphate buffer solution for 72h at 4°C, whereas native catalase lost 53% under the same condition. Especially, the activity of nanogranulated catalase was decreased only slightly in the simulated intestinal fluid containing α-chymotrypsin during 4h incubation at 37°C, implying that the catalase nanoparticle was more resistant to the degradation of proteases than native catalase molecules. Overall, catalase-only nanoparticles offered a great potential to stabilize enzymes for various pharmaceutical applications.

  2. Experimental study of the stability and flow characteristics of floating liquid columns confined between rotating disks

    Science.gov (United States)

    Fowle, A. A.; Soto, L.; Strong, P. F.; Wang, C. A.

    1980-01-01

    A low Bond number simulation technique was used to establish the stability limits of cylindrical and conical floating liquid columns under conditions of isorotation, equal counter rotation, rotation of one end only, and parallel axis offset. The conditions for resonance in cylindrical liquid columns perturbed by axial, sinusoidal vibration of one end face are also reported. All tests were carried out under isothermal conditions with water and silicone fluids of various viscosities. A technique for the quantitative measurement of stream velocity within a floating, isothermal, liquid column confined between rotatable disks was developed. In the measurement, small, light scattering particles were used as streamline markers in common arrangement, but the capability of the measurement was extended by use of stereopair photography system to provide quantitative data. Results of velocity measurements made under a few selected conditions, which established the precision and accuracy of the technique, are given. The general qualitative features of the isothermal flow patterns under various conditions of end face rotation resulting from both still photography and motion pictures are presented.

  3. Internet Addiction: Stability and Change

    Science.gov (United States)

    Huang, Chiungjung

    2010-01-01

    This longitudinal study examined five indices of stability and change in Internet addiction: structural stability, mean-level stability, differential stability, individual-level stability, and ipsative stability. The study sample was 351 undergraduate students from end of freshman year to end of junior year. Convergent findings revealed stability…

  4. Internet Addiction: Stability and Change

    Science.gov (United States)

    Huang, Chiungjung

    2010-01-01

    This longitudinal study examined five indices of stability and change in Internet addiction: structural stability, mean-level stability, differential stability, individual-level stability, and ipsative stability. The study sample was 351 undergraduate students from end of freshman year to end of junior year. Convergent findings revealed stability…

  5. Brazilian meningococcal C conjugate vaccine: physicochemical, immunological, and thermal stability characteristics.

    Science.gov (United States)

    Bastos, Renata Chagas; Corrêa, Marilza Batista; de Souza, Iaralice Medeiros; da Silva, Milton Neto; da Silva Gomes Pereira, Denise; Martins, Fernanda Otaviano; da Silva Faria, Camila; Ano Bom, Ana Paula Dinis; de Lourdes Leal, Maria; Jessouroun, Ellen; da Silva, José Godinho; de Andrade Medronho, Ricardo; da Silveira, Ivna Alana Freitas Brasileiro

    2017-09-19

    High temperature is known to cause some instability in polysaccharide-protein conjugated vaccines and studies under stress conditions may be useful in determining whether short-term accidental exposure to undesired conditions can compromise product quality. In this study, we examined the structural stability of three industrial batches of Brazilian Meningococcal C conjugate bulk (MPCT) incubated at 4, 37, and 55 °C for 5 weeks. The effect of exposure to the storage temperatures was monitored by HPLC-SEC, CZE, CD and NMR techniques. The immunological significance of any physicochemical changes observed in MPCT was determined by SBA and ELISA assays of serum from immunized mice. Fluorescence emission spectra at 4 and 37 °C were similar among all samples and compatible with the native fold of the carrier protein. Fluorescence spectra of MPCT stored at 55 °C decreased in intensity and had a significant red-shift, indicating conformational changes. Far-UV CD spectra revealed a trend toward loss of structural conformation as storage temperature was increased to 55 °C. The NMR data showed modified signal intensity of the aromatic and aliphatic residues, mainly for samples incubated at 55 °C, suggesting a partial loss of tertiary structure. About 50% free saccharide content was found in bulks stored at 55 °C, but no difference was observed in the IgG or SBA titers. The present study showed physicochemical methods alone are insufficient to predict the biological activity of a MPCT conjugate vaccine without extensive validation against immunological data. However, they provide a sensitive means of detecting changes induced in a vaccine exposed to adverse environmental condition.

  6. Water properties in fern spores: sorption characteristics relating to water affinity, glassy states, and storage stability.

    Science.gov (United States)

    Ballesteros, Daniel; Walters, Christina

    2007-01-01

    Ex situ conservation of ferns may be accomplished by maintaining the viability of stored spores for many years. Storage conditions that maximize spore longevity can be inferred from an understanding of the behaviour of water within fern spores. Water sorption properties were measured in spores of five homosporeous species of ferns and compared with properties of pollen, seeds, and fern leaf tissue. Isotherms were constructed at 5, 25, and 45 degrees C and analysed using different physicochemical models in order to quantify chemical affinity and heat (enthalpy) of sorption of water in fern spores. Fern spores hydrate slowly but dry rapidly at ambient relative humidity. Low Brunauer-Emmet-Teller monolayer values, few water-binding sites according to the D'Arcy-Watt model, and limited solute-solvent compatibility according to the Flory-Huggins model suggest that fern spores have low affinity for water. Despite the low water affinity, fern spores demonstrate relatively high values of sorption enthalpy (DeltaH(sorp)). Parameters associated with binding sites and DeltaH(sorp) decrease with increasing temperature, suggesting temperature- and hydration-dependent changes in volume of spore macromolecules. Collectively, these data may relate to the degree to which cellular structures within fern spores are stabilized during drying and cooling. Water sorption properties within fern spores suggest that storage at subfreezing temperatures will give longevities comparable with those achieved with seeds. However, the window of optimum water contents for fern spores is very narrow and much lower than that measured in seeds, making precise manipulation of water content imperative for achieving maximum longevity.

  7. Perceptions of variability in facial emotion influence beliefs about the stability of psychological characteristics.

    Science.gov (United States)

    Weisbuch, Max; Grunberg, Rebecca L; Slepian, Michael L; Ambady, Nalini

    2016-10-01

    Beliefs about the malleability versus stability of traits (incremental vs. entity lay theories) have a profound impact on social cognition and self-regulation, shaping phenomena that range from the fundamental attribution error and group-based stereotyping to academic motivation and achievement. Less is known about the causes than the effects of these lay theories, and in the current work the authors examine the perception of facial emotion as a causal influence on lay theories. Specifically, they hypothesized that (a) within-person variability in facial emotion signals within-person variability in traits and (b) social environments replete with within-person variability in facial emotion encourage perceivers to endorse incremental lay theories. Consistent with Hypothesis 1, Study 1 participants were more likely to attribute dynamic (vs. stable) traits to a person who exhibited several different facial emotions than to a person who exhibited a single facial emotion across multiple images. Hypothesis 2 suggests that social environments support incremental lay theories to the extent that they include many people who exhibit within-person variability in facial emotion. Consistent with Hypothesis 2, participants in Studies 2-4 were more likely to endorse incremental theories of personality, intelligence, and morality after exposure to multiple individuals exhibiting within-person variability in facial emotion than after exposure to multiple individuals exhibiting a single emotion several times. Perceptions of within-person variability in facial emotion-rather than perceptions of simple diversity in facial emotion-were responsible for these effects. Discussion focuses on how social ecologies shape lay theories. (PsycINFO Database Record

  8. 小展弦比飞翼标模纵航向气动特性低速实验研究%Low speed experiment on longitudinal and lateral aerodynamic characteristics of the low aspect ratio flying wing calibration model

    Institute of Scientific and Technical Information of China (English)

    吴军飞; 秦永明; 黄湛; 魏忠武; 贾毅

    2016-01-01

    对小展弦比飞翼气动布局外形,通过常规测力风洞实验方法得到其纵向气动特性和偏航控制特性,在分析其气动特性后,选取典型的状态采用 PIV 实验方法对其流动机理进行研究,研究表明小展弦比飞翼在较小的迎角下即出现前缘分离涡,随着迎角的增大,前缘分离涡强度增大,且逐渐往机体对称面方向移动,随着迎角进一步增大,分离涡变得不稳定,涡核开始摆动,最终破裂,破裂位置从后缘开始,逐渐前移。对小展弦比飞翼气动布局飞机的控制难点偏航控制进行研究,结果表明该飞翼布局模型在实验迎角范围内偏航方向是静稳定的,在小迎角下具有可操纵性,迎角大于6°后嵌入面处于破裂的前缘涡尾迹之中,操纵性降低。%longitudinal and lateral aerodynamic characteristics of the low aspect ratio flying wing calibration model are investigated in a low speed wind tunnel.Normal force measuring ex-periment is conducted to gain the longitudinal aerodynamic characteristics and yaw control charac-teristics,and the PIV test is also conducted to investigate the flow mechanism of the low aspect ratio flying wing.The results indicate that the leading-edge separation vortex appears on the wing’s spine surface when the attack angle is at 6 degree.The vortex intensity increases and the vortex core shifts to the symmetric plane of flying wing with the increase of attack angle.Increas-ing the attack angle further,the vortex core becomes unsteady and begins to oscillate,finally break entirely.The broken position shifts from the ending edge to the leading edge.Yaw control characteristics of low aspect ratio flying wing is also studied in this paper.The results indicate that the flying wing is static stabile at the test attack angle.When the attack angle is less than 6 degree,it is controllable in yaw direction.And when attack angle is more than 6 degree,the yaw control

  9. Advanced oxidation protein products in plasma: stability during storage and correlation with other clinical characteristics.

    Science.gov (United States)

    Matteucci, E; Biasci, E; Giampietro, O

    2001-12-01

    Proteins are susceptible to free radical damage. We measured advanced oxidation protein products (AOPP) in the plasma of 56 hospitalised patients. Concentrations of AOPP were expressed as chloramine-T equivalents by measuring absorbance in acidic conditions at 340 nm in the presence of potassium iodide. We also determined erythrocyte sedimentation rate (ESR), circulating urea, creatinine, glucose, uric acid, electrolytes, lipids, total proteins and fractions and fibrinogen. Twenty-four samples were processed both immediately and after 7, 15, 30, 90, 180 and 438 days of storage at both at -20 degrees C and -80 degrees C (aliquots were frozen and thawed only once) to evaluate AOPP stability. The remaining 32 samples were also processed for thiobarbituric-acid-reactive substances (TBARS). Mean AOPP concentration in all 56 patients was 48.3+/-37.2 microM. Mean basal concentration of AOPP in the 24 plasma samples (55.0+/-47.1 microM) showed no significant change at each intermediate determination, yet significantly increased after 438 days of storage both at -80 degrees C (96.6+/-83.2, p<0.01) and, markedly, at -20 degrees C (171.3+/-94.6, p<0.001). TBARS concentration was 1.59+/-0.65 micromol/l. Multiple regression analysis evidenced that AOPP concentration was positively correlated (multiple r=0.62, p<0.001) with serum urea and triglycerides, but negatively correlated with patient age (indeed, serum albumin and total proteins decreased with increasing age, r=0.3, p<0.05). TBARS concentration was associated with ESR and serum glucose (multiple r=0.73, p<0.001), yet positively with AOPP (r=0.39, simple p<0.05). We conclude that AOPP remain stable during sample storage both at -20 degrees C and -80 degrees C for 6 months. Renal failure and hypertriglyceridemia probably enhance the in vivo process of AOPP formation. Oxidative damage as measured by TBARS may be increased because of exposure to hyperglycemia causing nonenzymatic glycation of plasma proteins.

  10. The i-V curve characteristics of burner-stabilized premixed flames: detailed and reduced models

    KAUST Repository

    Han, Jie

    2016-07-17

    The i-V curve describes the current drawn from a flame as a function of the voltage difference applied across the reaction zone. Since combustion diagnostics and flame control strategies based on electric fields depend on the amount of current drawn from flames, there is significant interest in modeling and understanding i-V curves. We implement and apply a detailed model for the simulation of the production and transport of ions and electrons in one-dimensional premixed flames. An analytical reduced model is developed based on the detailed one, and analytical expressions are used to gain insight into the characteristics of the i-Vcurve for various flame configurations. In order for the reduced model to capture the spatial distribution of the electric field accurately, the concept of a dead zone region, where voltage is constant, is introduced, and a suitable closure for the spatial extent of the dead zone is proposed and validated. The results from the reduced modeling framework are found to be in good agreement with those from the detailed simulations. The saturation voltage is found to depend significantly on the flame location relative to the electrodes, and on the sign of the voltage difference applied. Furthermore, at sub-saturation conditions, the current is shown to increase linearly or quadratically with the applied voltage, depending on the flame location. These limiting behaviors exhibited by the reduced model elucidate the features of i-V curves observed experimentally. The reduced model relies on the existence of a thin layer where charges are produced, corresponding to the reaction zone of a flame. Consequently, the analytical model we propose is not limited to the study of premixed flames, and may be applied easily to others configurations, e.g.~nonpremixed counterflow flames.

  11. Characteristics of Cu stabilized Nb3Al strands with low Cu ratio

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, A.; Yamada, R.; Barzi, E.; Kobayashi, M.; Lamm, M.; Nakagawa, K.; Sasaki, K.; Takeuchi, T.; Turrioni, D.; Zlobin, A.V.; /NIMC, Tsukuba /Fermilab /Hitachi, Tsuchiura Works /KEK, Tsukuba

    2008-12-01

    Characteristics of recently developed F4-Nb{sub 3}Al strand with low Cu ratio are described. The overall J{sub c} of the Nb{sub 3}Al strand could be easily increased by decreasing of the Cu ratio. Although the quench of a pulse-like voltage generation is usually observed in superconducting unstable conductor, the F4 strand with a low Cu ratio of 0.61 exhibited an ordinary critical transition of gradual voltage generation. The F4 strand does not have magnetic instabilities at 4.2 K because of the tantalum interfilament matrix. The overall J{sub c} of the F4 strand achieved was 80-85% of the RRP strand. In the large mechanical stress above 100 MPa, the overall J{sub c} of the F4 strand might be comparable to that of high J{sub c} RRP-Nb{sub 3}Sn strands. The Rutherford cable with a high packing factor of 86.5% has been fabricated using F4 strands. The small racetrack magnet, SR07, was also fabricated by a 14 m F4 cable. The quench current, I{sub q}, of SR07 were obtained 22.4 kA at 4.5 K and 25.2 kA at 2.2 K. The tantalum matrix Nb{sub 3}Al strands are promising for the application of super-cooled high-field magnets as well as 4.2 K operation magnets.

  12. Propagation and stability characteristics of a 500-m-long laser-based fiducial line for high-precision alignment of long-distance linear accelerators.

    Science.gov (United States)

    Suwada, Tsuyoshi; Satoh, Masanori; Telada, Souichi; Minoshima, Kaoru

    2013-09-01

    A laser-based alignment system with a He-Ne laser has been newly developed in order to precisely align accelerator units at the KEKB injector linac. The laser beam was first implemented as a 500-m-long fiducial straight line for alignment measurements. We experimentally investigated the propagation and stability characteristics of the laser beam passing through laser pipes in vacuum. The pointing stability at the last fiducial point was successfully obtained with the transverse displacements of ±40 μm level in one standard deviation by applying a feedback control. This pointing stability corresponds to an angle of ±0.08 μrad. This report contains a detailed description of the experimental investigation for the propagation and stability characteristics of the laser beam in the laser-based alignment system for long-distance linear accelerators.

  13. Longitudinal aerodynamic characteristics at Mach numbers from 1.60 to 2.86 for a fixed-span missile with three wing planforms. [conducted in the Langley Unitary Plan wind tunnel

    Science.gov (United States)

    Spearman, M. L.; Sawyer, W. W.

    1977-01-01

    Effects of wing planform modifications on the longitudinal aerodynamic characteristics of a fixed span, maneuverable cruciform missile configuration were determined. A basic delta planform and two alternate trapezoidal planforms having progressively increasing tip chords were included. Data were obtained for angles of attack up to approximately -32 deg, model roll angles of 0 deg to 45 deg, and tail control deflections of 0 deg and -20 deg. The experimental drag due to lift was compared with linear values.

  14. Fermentation characteristics and aerobic stability of wet corn distillers grains with solubles ensiled in combination with whole plant corn.

    Science.gov (United States)

    Mjoun, Kamal; Kalscheur, Kenneth F; Garcia, Alvaro D

    2011-05-01

    Wet corn distillers grains with solubles (WDG) are prone to aerobic spoilage when stored for an extended period of time. The objective of this study was to evaluate the fermentation characteristics of ensiling WDG with whole plant corn (WPC) using the following combinations: (1) 100% WPC; (2) 75% WPC + 25% WDG; (3) 50% WPC + 50% WDG; and (4) 100% WDG. The initial pH was greatest for 100% WPC and lowest for 100% WDG (5.7, 4.6, 4.0, and 3.1, respectively). Concentrations of ammonia nitrogen (12.0, 26.8, 40.7, and 50.8 g kg(-1) dry matter (DM)) and Crude protein (CP) (98.7, 155.8, 206.8, and 307.9 g kg(-1) of DM) increased with increasing concentrations of WDG. Lactic acid concentration prior to ensiling was greatest for 100% WDG (9.0 g kg(-1) DM) and decreased with WPC in the silage. Acetic, propionic, and butyric acids were not present prior to ensiling. The pH of the ensiled feeds dropped below 4.0 by day 3, with no further decrease over time. Acetic acid increased from undetected amounts at day 0 to 38.8, 43.9, 43.2, and 2.2 g kg(-1) of DM at day 129 as concentration of WDG increased. Aerobic stability was enhanced with increasing WDG concentration in the silage. Fermentation, nutrient profile, and aerobic stability can be improved when ensiling wet distillers grains with whole plant corn. Copyright © 2011 Society of Chemical Industry.

  15. Longitudinal Patterns of Stability and Change in Tenacious Goal Pursuit and Flexible Goal Adjustment among Older People over a 9-Year Period

    Directory of Open Access Journals (Sweden)

    Guillaume Martinent

    2017-01-01

    Full Text Available Using the dual-process model of assimilative-tenacity (TGP and accommodative-flexibility (FGA, the study aims to identify trajectories of TGP and FGA over five time points within a 9-year period, explore the relationships between the trajectories of TGP and FGA, and explore if participants from distinct TGP and FGA trajectories differed in indicators of well-being and depression. Latent class growth analysis was used in a five-wave longitudinal design among an older population of 747 participants over 65 years. Results highlight (1 emergence of four trajectories for flexibility (low and increasing, moderate and increasing, moderately high and stable, and high and stable trajectories and three trajectories for tenacity (low and stable, moderate and stable, and high and decreasing trajectories, (2 that older people belonging to particular trajectories of FGA are not more likely to belong to particular trajectories of TGP, and (3 that participants from the high and decreasing TGP and high or moderately high and stable FGA trajectories were characterized by high score of perceived health, satisfaction with life, and self-esteem and low score of depression moods. These results highlight that the heterogeneity in longitudinal TGP and FGA scores throughout the life span needs to be accounted for in future research.

  16. Impact of pulsed-electric field and high-voltage electrical discharges on red wine microbial stabilization and quality characteristics.

    Science.gov (United States)

    Delsart, C; Grimi, N; Boussetta, N; Miot Sertier, C; Ghidossi, R; Vorobiev, E; Mietton Peuchot, M

    2016-01-01

    In this study, pulsed-electric fields (PEF) and high-voltage electrical discharges (HVED) are proposed as new techniques for the microbial stabilization of red wines before bottling. The efficiency of the treatment was then evaluated. PEF and HVED-treatments have been applied to wine for the inactivation of Oenococcus oeni CRBO 9304, O. oeni CRBO 0608, Pediococcus parvulus CRBO 2.6 and Brettanomyces bruxellensis CB28. Different treatment times (1, 2, 4, 6, 8 and 10 ms) were used at 20 kV cm(-1) for the PEF treatments and at 40 kV for the HVED treatments, which correspond to applied energies from 80 to 800 kJ l(-1) . The effects of the treatments on the microbial inactivation rate and on various characteristics of red wines (phenolic composition, chromatic characteristics and physico-chemical parameters) were measured. The application of PEF or HVED treatments on red wine allowed the inactivation of alteration yeasts (B. bruxellensis CB28) and bacteria (O. oeni CRBO 9304, O. oeni CRBO 0608 and P. parvulus CRBO 2.6). The electric discharges at 40 kV were less effective than the PEF even after 10 ms of treatments. Indeed, 4 ms of PEF treatment at 20 kV cm(-1) were sufficient to inactivate all micro-organisms present in the wines. Also, the use of PEF had no negative impact on the composition of wines compared to the HVED treatments. Contrary to PEF, the phenolics compounds were degraded after the HVED treatment and the physico-chemical composition of wine were modified with HVED. PEF technology seems to be an interesting alternative to stabilize microbiologically wines before bottling and without modifying their composition. This process offers many advantages for winemakers: no chemical inputs, low energy consumption (320 kJ l(-1) ), fast (treatment time of 4 ms) and athermal (ΔT ≈ 10°C). © 2015 The Society for Applied Microbiology.

  17. Amphiphilic cellulose nanocrystals from acid-free oxidative treatment: physicochemical characteristics and use as an oil-water stabilizer.

    Science.gov (United States)

    Visanko, Miikka; Liimatainen, Henrikki; Sirviö, Juho Antti; Heiskanen, Juha Pentti; Niinimäki, Jouko; Hormi, Osmo

    2014-07-14

    A chemical pretreatment for producing cellulose nanocrystals (CNCs) with periodate oxidation and reductive amination is reported. This new functionalization of cellulose fibers dispenses an alternative method for fabricating individual CNCs without the widely used acid hydrolysis process. CNCs can be directly modified during the pretreatment step, and no additional post-treatments are required to tune the surface properties. Three butylamine isomers were tested to fabricate CNCs with amphiphilic features. After mechanical homogenization, CNCs occurred as individual crystallinities without aggregation where high uniformity in terms of shape and size was obtained. The elemental analysis and (1)H NMR measurement show that iso- and n-butylamine attach the highest number of butylamino groups to the cellulose fibers. Linking the alkyl groups increases the hydrophobic nature of the CNCs, where water contact angles from self-standing films up to 110.5° are reported. Since these butylamino-functionalized CNCs have hydrophobic characteristics in addition to the hydrophilic backbone of cellulose, the stabilization impact on oil/water emulsions is demonstrated as a potential application.

  18. A longitudinal study of the effects of premarital communication, relationship stability, and self-esteem on sexual satisfaction in the first year of marriage.

    Science.gov (United States)

    Larson, J H; Anderson, S M; Holman, T B; Niemann, B K

    1998-01-01

    This study examined select premarital factors from the ecosystemic perspective hypothesized to influence marital sexual satisfaction in the first year of marriage. A sample of 70 couples was administered by the Preparation of Marriage Questionnaire (PREP-M) a few months prior to marriage to measure premarital levels of empathy, self-disclosure, open communication, relationship stability, and self-esteem. At 1 year of marriage, their sexual satisfaction was assessed using the Index of Sexual Satisfaction (ISS). Using multiple regression analyses it was found that the best premarital predictors of husband's marital sexual satisfaction were wives' self-esteem, wives' open communication, and wives' relationship stability. The best predictors for wives' marital sexual satisfaction were wives' self-esteem, wives' open communication, and husbands' empathic communication. Conclusions and implications for premarital counselling and family life education are discussed.

  19. Genetic and Environmental Contributions to Stability and Change of ADHD Symptoms between 8 and 13 Years of Age: A Longitudinal Twin Study

    Science.gov (United States)

    Larsson, Jan-Olov; Larsson, Henrik; Lichtenstein, Paul

    2004-01-01

    Objective: To study the genetic and environmental contributions to stability and change of attention-deficit/hyperactivity disorder (ADHD) symptoms between 8 and 9 and 13 and 14 years of age. Method: The sample included 1,480 twin pairs born in Sweden between May 1985 and December 1986. At wave 1 in 1994, when twins were 8-9 years old, 1,106 (75%)…

  20. Effects of types and amounts of stabilizers on physical and sensory characteristics of cloudy ready-to-drink mulberry fruit juice.

    Science.gov (United States)

    Akkarachaneeyakorn, Suthida; Tinrat, Sirikhwan

    2015-05-01

    In this study, the pH of mulberry juice was optimized for high anthocyanin content and an attractive red color. Mulberry juice pH values of 2.5, 4.0, 6.0, and 8.0 were evaluated. A pH of 2.5 gave an anthocyanin content of 541.39 ± 106.43 mg of cyanidin-3-glucoside per liter, and the a* value was 14 ± 1.00. The effects of stabilizers (CMC and xanthan gum) on the physical characteristics of cloudy ready-to-drink mulberry fruit juice (via the addition of mulberry fruit pulp at a mass fraction of 5%) during storage (4°C for 1 week) were also determined using different mass fractions of the stabilizers (0.1%, 0.3%, and 0.5%). Increasing the stabilizer mass fraction increased the viscosity, turbidity, stability of turbidity, and h* value. Using xanthan gum as the stabilizer produced better results for these parameters than CMC. The type of stabilizer and its mass fraction had no effect on most sensory characteristics, including appearance, color, taste, texture, and overall acceptability (P ≥ 0.05), but did affect the odor (P ≥ 0.05). Xanthan gum stabilizer gave the juice a better odor than CMC. Cloudy mulberry juice containing 0.5% xanthan gum as the stabilizer had the highest acceptance rate among panelists (average acceptance was 6.90 ± 1.37 points) and produced no precipitate during storage.

  1. Psychometric Characteristics and Clinical Correlates of NEO-PI-R Fearless Dominance and Impulsive Antisociality in the Collaborative Longitudinal Personality Disorders Study

    Science.gov (United States)

    Witt, Edward A.; Hopwood, Christopher J.; Morey, Leslie C.; Markowitz, John C.; McGlashan, Thomas H.; Grilo, Carlos M.; Sanislow, Charles A.; Shea, M. Tracie; Skodol, Andrew E.; Gunderson, John G.; Donnellan, M. Brent

    2010-01-01

    This study evaluates the validity of derived measures of the psychopathic personality traits of Fearless Dominance and Impulsive Antisociality from the NEO Personality Inventory-Revised (NEO-PI-R; Costa & McCrae, 1992) using data from the Collaborative Longitudinal Personality Disorders Study (baseline N = 733). These 3 issues were examined:…

  2. Genetic Risk and Outcome of Psychosis (GROUP), a multi site longitudinal cohort study focused on gene-environment interaction : objectives, sample characteristics, recruitment and assessment methods

    NARCIS (Netherlands)

    Korver, Nikie; Quee, Piotr J.; Boos, Heleen B. M.; Simons, Claudia J. P.; de Haan, Lieuwe

    2012-01-01

    Objective A longitudinal focus on geneenvironment vulnerability and resilience in both patients, their unaffected family members and non-related controls offers the opportunity to elucidate etiological and pathogenetic factors influencing the onset and course of psychotic disorders. The current pape

  3. Psychometric Characteristics and Clinical Correlates of NEO-PI-R Fearless Dominance and Impulsive Antisociality in the Collaborative Longitudinal Personality Disorders Study

    Science.gov (United States)

    Witt, Edward A.; Hopwood, Christopher J.; Morey, Leslie C.; Markowitz, John C.; McGlashan, Thomas H.; Grilo, Carlos M.; Sanislow, Charles A.; Shea, M. Tracie; Skodol, Andrew E.; Gunderson, John G.; Donnellan, M. Brent

    2010-01-01

    This study evaluates the validity of derived measures of the psychopathic personality traits of Fearless Dominance and Impulsive Antisociality from the NEO Personality Inventory-Revised (NEO-PI-R; Costa & McCrae, 1992) using data from the Collaborative Longitudinal Personality Disorders Study (baseline N = 733). These 3 issues were examined: (a)…

  4. A First Look at the Characteristics of Children and Families Entering Early Intervention Services. Data Report. National Early Intervention Longitudinal Study (NEILS).

    Science.gov (United States)

    Hebbeler, Kathleen; Wagner, Mary; Spiker, Donna; Scarborough, Anita; Simeonsson, Rune; Collier, Marnie

    The National Early Intervention Longitudinal Study (NEILS) is being conducted to address important questions related to the implementation and outcomes of Part C of the Individuals with Disabilities Education Act (IDEA). NEILS is following a nationally representative sample of children from birth to 3 years old and their families through and after…

  5. Colorado Longitudinal Twin Study of Reading Disability

    Science.gov (United States)

    Wadsworth, Sally J.; DeFries, John C.; Olson, Richard K.; Willcutt, Erik G.

    2007-01-01

    The primary objectives of the present study are to introduce the Colorado Longitudinal Twin Study of Reading Disability, the first longitudinal twin study in which subjects have been specifically selected for having a history of reading difficulties, and to present some initial assessments of the stability of reading performance and cognitive…

  6. 具有时滞的非线性纵向飞行模型稳定性和分支分析%Stability and bifurcation analysis of nonlinear model for longitudinal motion with time delay

    Institute of Scientific and Technical Information of China (English)

    范丽; 史忠科

    2013-01-01

      研究一类具有时滞的非线性飞行模型的稳定性和分支问题。首先考虑数据测量的时间延迟,给出了含时滞的大迎角纵向多项式飞行模型;然后应用泛函微分方程Hopf分支理论和中心流形等非线性方法给出了该模型稳定性和分支的解析分析,得到了由时滞引起的Hopf分支存在条件、分支点计算公式以及分支周期解的稳定性判别准则;最后利用所得结论进行了飞行实例分析,分析结果表明,数据测量延时可能会引起飞行稳定性的改变,而且延时超过一定临界值时将产生Hopf分支,出现纵向周期振荡,其结论具有实际参考意义。%  The stability and bifurcations of a nonlinear flight system with time delay are investigated. Firstly, considering the time delay in measurement of angle of attack, a polynomial differential system with time delay for aircraft longitudinal motion is suggested. Then by applying Hopf bifurcation and center manifold theories of functional differential equations, the stability and bifurcations of the time-delayed system are studied analytically, and existence conditions for Hopf bifurcations as well as formulas for calculating bifurcation points and stability of the bifurcation limit cycle are derived. Finally, the theoretical conclusions are applied to analyze a practical example of high angle-of-attack flight. The results show that the delay in the measurement of angle of attack can cause instability, moreover, the Hopf bifurcation occurs and the periodic oscillation of longitudinal direction arises when the measurement delay exceeds the critical value. The conclusion has the reference significance in practice.

  7. 超高速水下航行器纵向运动稳定性分析%Analysis on Motion Stability of High Speed Underwater Vehicle in Longitudinal Plane

    Institute of Scientific and Technical Information of China (English)

    邹启明; 王改娣

    2013-01-01

    In order to study cavitation drag reduction of a high speed underwater vehicle, we establish a longitudinal motion model of the vehicle in supercavitation condition, analyze the step responses of attack angle and pitch angular velocity of the vehicle under turbulence in the balance state of cruise phase, and also analyze the motion stability through the root locus method. The results show that the vehicle can exhibit static stabilization under given balanceable attack angle and rudder angle, which is beneficial to keeping stability of a high speed underwater vehicle with straight running trajectory.%为了进一步研究超高速航行器空化减阻问题,建立了空化状态下超高速水下航行器纵向运动数学模型,对该航行器在巡航段平衡状态下受扰动时的攻角和俯仰角速度的阶跃响应进行了分析,并通过根轨迹法分析了运动的稳定性。分析结果表明,通过给定平衡攻角和平衡舵角,航行器能够呈现一定的静稳定性,该特性有利于以直航弹道为主的超高速水下航行器保持超空泡稳定。

  8. Stability of the DSM-5 Section III pathological personality traits and their longitudinal associations with psychosocial functioning in personality disordered individuals.

    Science.gov (United States)

    Wright, Aidan G C; Calabrese, William R; Rudick, Monica M; Yam, Wern How; Zelazny, Kerry; Williams, Trevor F; Rotterman, Jane H; Simms, Leonard J

    2015-02-01

    This study was conducted to establish (a) the stability of the DSM-5 Section III personality disorder (PD) traits, (b) whether these traits predict future psychosocial functioning, and (c) whether changes in traits track with changes in psychosocial functioning across time. Ninety-three outpatients (61% female) diagnosed with at least 1 PD completed patient-report measures at 2 time-points (M time between assessments = 1.44 years), including the Personality Inventory for the DSM-5 and several measures of psychosocial functioning. Effect sizes of rank-order and mean-level change were calculated. In addition, Time 1 traits were used to predict functioning measures at Time 2. Finally, latent change score models were estimated for DSM-5 Section III traits and functioning measures, and correlations among latent change scores were calculated to establish the relationship between change in traits and functional outcomes. Findings demonstrated that the DSM-5 Section III traits were highly stable in terms of normative (i.e., mean-level) change and rank-order stability over the course of the study. Furthermore, traits prospectively predicted psychosocial functioning. However, at the individual level traits and functioning were not entirely static over the study, and change in individuals' functioning tracked with changes in trait levels. These findings demonstrate that the DSM-5 Section III traits are highly stable consistent with the definition of PD, prospectively predictive of psychosocial functioning, and are dynamically associated with functioning over time. This study provides important evidence in support of the DSM-5 Section III PD model.

  9. Study of the stability of electrode metal melting and transfer in the process of consumable electrode welding powered by supplies with differing dynamic characteristics

    Science.gov (United States)

    Saraev, Y. N.; Chinakhov, D. A.; Il'yashchenko, D. P.; Kiselev, A. S.; Gardiner, A. S.; Raev, I. V.

    2016-11-01

    In the paper we present the results of the study of the power supply characteristics effect upon the stability of electrode metal melting and transfer into the weld pool in the process of consumable electrode welding. It was shown that application of inverter type welding power supplies of the new generation results in changing the characteristics of the heat and mass transfer which has a decisive impact upon the heat content of the weld pool, reduction of residual stresses in the heat-affected zone (HAZ). The authors also substantiate the tendency to the reduction of the structural constituents in the area of the permanent joint.

  10. Immunochemical faecal occult blood tests have superior stability and analytical performance characteristics over guaiac-based tests in a controlled in vitro study.

    LENUS (Irish Health Repository)

    Lee, Chun Seng

    2011-06-01

    The aims of this study were (1) to determine the measurement accuracy of a widely used guaiac faecal occult blood test (gFOBT) compared with an immunochemical faecal occult blood test (iFOBT) during in vitro studies, including their analytical stability over time at ambient temperature and at 4°C; and (2) to compare analytical imprecision and other characteristics between two commercially available iFOBT methods.

  11. Physical characteristics of the coastal waters between Navapur and Umbharat, West coast of India. Part 3. Stability and dispersion

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.; Vijayakumar, C.V.

    Vertical profiles of currents of the coastal waters between Navapur and Umbharat were analysed. Dynamic stability as well as the diffusion capacity of the water columns were estimated from the vertical distribution of temperature, salinity...

  12. Factorial invariance and stability of the Effort-Reward Imbalance Scales: a longitudinal analysis of two samples with different time lags.

    Science.gov (United States)

    de Jonge, Jan; van der Linden, Sjaak; Schaufeli, Wilmar; Peter, Richard; Siegrist, Johannes

    2008-01-01

    Key measures of Siegrist's (1996) Effort-Reward Imbalance (ERI) Model (i.e., efforts, rewards, and overcommitment) were psychometrically tested. To study change in organizational interventions, knowledge about the type of change underlying the instruments used is needed. Next to assessing baseline factorial validity and reliability, the factorial stability over time - known as alpha-beta-gamma change - of the ERI scales was examined. Psychometrics were tested among 383 and 267 healthcare workers from two Dutch panel surveys with different time lags. Baseline results favored a five-factor model (i.e., efforts, esteem rewards, financial/career-related aspects, job security, and overcommitment) over and above a three-factor solution (i.e., efforts, composite rewards, and overcommitment). Considering changes as a whole, particularly the factor loadings of the three ERI scales were not equal over time. Findings suggest in general that moderate changes in the ERI factor structure did not affect the interpretation of mean changes over time. Occupational health researchers utilizing the ERI scales can feel confident that self-reported changes are more likely to be due to factors other than structural change of the ERI scales over time, which has important implications for evaluating job stress and health interventions.

  13. Genetic and environmental influences on personality trait stability and growth during the transition to adulthood: a three-wave longitudinal study.

    Science.gov (United States)

    Hopwood, Christopher J; Donnellan, M Brent; Blonigen, Daniel M; Krueger, Robert F; McGue, Matt; Iacono, William G; Burt, S Alexandra

    2011-03-01

    During the transition to adulthood individuals typically settle into adult roles in love and work. This transition also involves significant changes in personality traits that are generally in the direction of greater maturity and increased stability. Competing hypotheses have been offered to account for these personality changes: The intrinsic maturation hypothesis suggests that change trajectories are endogenous, whereas the life-course hypothesis suggests that these changes occur because of transactions with the social environment. This study investigated the patterns and origins of personality trait changes from ages 17 to 29 using 3 waves of Multidimensional Personality Questionnaire data provided by twins. Results suggest that (a) trait changes were more profound in the first relative to the second half of the transition to adulthood; (b) traits tend to become more stable during the second half of this transition, with all the traits yielding retest correlations between .74 and .78; (c) Negative Affectivity declined over time, and Constraint increased over time; minimal change was observed on agentic or communal aspects of Positive Emotionality; and (d) both genetic and nonshared environmental factors accounted for personality changes. Overall, these genetically informed results support a life-course perspective on personality development during the transition to adulthood.

  14. On the effect of a longitudinal magnetic field on oscillatory characteristics of a subnormal region in discharge in argon

    Indian Academy of Sciences (India)

    D C Jana; S S Pradhan

    2003-06-01

    Oscillating nature of current pulses under d.c. excitation in subnormal region with longitudinal magnetic field at pressure range 0.20 torr to 0.85 torr have been studied. The frequency, bandwidth, peak–peak voltage, cut-off current and rise time of the current pulses have been observed with pressure, average tube current and magnetic field. A study of these oscillograms in magnetic field, average tube current and pressure are presented. The probable mechanism for the generation of oscillation based on space-charge field modification with magnetic field is discussed.

  15. Uncertainty of the Soil–Water Characteristic Curve and Its Effects on Slope Seepage and Stability Analysis under Conditions of Rainfall Using the Markov Chain Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Weiping Liu

    2017-10-01

    Full Text Available It is important to determine the soil–water characteristic curve (SWCC for analyzing slope seepage and stability under the conditions of rainfall. However, SWCCs exhibit high uncertainty because of complex influencing factors, which has not been previously considered in slope seepage and stability analysis under conditions of rainfall. This study aimed to evaluate the uncertainty of the SWCC and its effects on the seepage and stability analysis of an unsaturated soil slope under conditions of rainfall. The SWCC model parameters were treated as random variables. An uncertainty evaluation of the parameters was conducted based on the Bayesian approach and the Markov chain Monte Carlo (MCMC method. Observed data from granite residual soil were used to test the uncertainty of the SWCC. Then, different confidence intervals for the model parameters of the SWCC were constructed. The slope seepage and stability analysis under conditions of rainfall with the SWCC of different confidence intervals was investigated using finite element software (SEEP/W and SLOPE/W. The results demonstrated that SWCC uncertainty had significant effects on slope seepage and stability. In general, the larger the percentile value, the greater the reduction of negative pore-water pressure in the soil layer and the lower the safety factor of the slope. Uncertainties in the model parameters of the SWCC can lead to obvious errors in predicted pore-water pressure profiles and the estimated safety factor of the slope under conditions of rainfall.

  16. WE-D-204-03: A Six-Year Longitudinal Evaluation of the DICOM GSDF Conformance Stability of LCD Monitors

    Energy Technology Data Exchange (ETDEWEB)

    McKenney, S; Bevins, N; Flynn, M [Henry Ford Health System, Detroit, MI (United States); Olariu, E [William Beaumont Hospital, Royal Oak, MI (United States)

    2015-06-15

    Purpose: The calibration of monitors in radiology is critical to ensure a standardized reading environment. If left unchecked, monitors initially calibrated to follow the DICOM Grayscale Standard Display Function (GSDF) can fall out of calibration. This work presents a quantitative evaluation of the stability of a cohort of monitors with similar deployment times and clinical utilization. Methods: Fifty-four liquid crystal display (LCD) monitors (NEC L200ME) were deployed for clinical use in 2009. At that time, a subset of eight of these monitors were used to generate a look-up table (LUT) using the open-source software pacsDisplay. The software was used to load the LUT to the graphics card of the computer in order to make the monitors compliant with the GSDF. The luminance response of the monitors was evaluated twice over six years, once in 2011 and again in 2015. Results: As expected, the maximum luminance of the monitors decreased over time, with an average reduction from 2009 of 35% in 2011, and 53% in 2015. The luminance ratio (maximum luminance divided by the minimum) also decreased, with the all of the decrease occurring in the first two years (average 20%). There was an overall increase in relative error compared with the DICOM GSDF from measurement to measurement, indicating that deviation from the GSDF increases with monitor luminance reduction. Along with changes in luminance, several other issues were identified during the testing, including non-uniformities, bad pixels, and missing calibration software. Conclusion: From the initial installation of these monitors, most of the degradation occurred during the first two years, highlighting the importance of routine clinical testing of displays. Following such quality assurance, displays could be either re-calibrated or replaced depending on different thresholds. In addition, other issues not related to luminance could be identified and corrected.

  17. Internato Longitudinal

    Directory of Open Access Journals (Sweden)

    Marcelo Marcos Piva Demarzo

    Full Text Available O internato médico tem gerado recorrente debate frente às transformações curriculares em andamento no País. A despeito das discussões, um modelo de internato consonante com essas mudanças ainda não foi consistentemente delineado. Neste ensaio, trazemos uma proposta de matriz estruturante para o internato médico. Propomos que o internato médico seja realizado durante os seis anos do curso, de forma longitudinal, tendo como eixo estruturante a clínica da Atenção Básica (AB. Esse modelo de "internato longitudinal" prevê a introdução progressiva na prática clínica, iniciando-se pela AB nos dois primeiros anos, acrescentando-se progressivamente os ambulatórios de especialidades, os estágios hospitalares e demais atividades práticas, alcançando-se, dessa forma, o rol de diversidade e complexidade previsto para o egresso da escola médica.

  18. Exponential stability and control of vehicle longitudinal following system with impulsive effects and time-varying delays%脉冲变时滞车辆纵向跟随系统的群指数稳定性与控制

    Institute of Scientific and Technical Information of China (English)

    徐晓惠; 张继业; 张克跃

    2012-01-01

    On the assumption that all the isolated subsystems of the interconnected system are exponentially stable,the exponential stability analysis and control for a class of look-ahead vehicle longitudinal following system with impulsive effects and time-varying delays are studied. Firstly,some sufficient conditions for exponential stability of the system are obtained by applying vector Lyapunov function method and mathematical induction method. Then,the controller for the look-ahead vehicle following system with impulsive effects and time-varying delays is designed by sliding mode control method based on the obtained results. Finally,a simulation example illustrates how to apply the obtained results in practice.%针对具有脉冲扰动和变时滞的顾前车辆纵向跟随系统,在假设各孤立子系统指数稳定的前提下,分析了该系统的群指数稳定性与控制.首先利用向量Lyapunov函数法和数学归纳法给出确保该系统群指数稳定的充分条件;然后基于得到的稳定性条件,采用滑模变结构控制策略对脉冲变时滞车辆纵向跟随系统进行控制器设计;最后通过一个数值仿真算例验证了所得结论的正确性以及在实际中如何应用.

  19. Parametric Trends in the Combustion Stability Characteristics of a Single-Element Gas-Gas Rocket Engine

    Science.gov (United States)

    2013-12-01

    toroidal recirculation zone which promotes flame stabilization.16 For rocket applications swirl injectors are less sensitive to manufacturing defects and...were there are geometric changes. The mesh contains 5 of 22 American Institute of Aeronautics and Astronautics Figure 2: Geometric details of the

  20. Total ionizing dose effect of γ-ray radiation on the switching characteristics and filament stability of HfOx resistive random access memory

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Runchen; Yu, Shimeng, E-mail: shimengy@asu.edu [School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, Arizona 85281 (United States); School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Gonzalez Velo, Yago; Chen, Wenhao; Holbert, Keith E.; Kozicki, Michael N.; Barnaby, Hugh [School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)

    2014-05-05

    The total ionizing dose (TID) effect of gamma-ray (γ-ray) irradiation on HfOx based resistive random access memory was investigated by electrical and material characterizations. The memory states can sustain TID level ∼5.2 Mrad (HfO{sub 2}) without significant change in the functionality or the switching characteristics under pulse cycling. However, the stability of the filament is weakened after irradiation as memory states are more vulnerable to flipping under the electrical stress. X-ray photoelectron spectroscopy was performed to ascertain the physical mechanism of the stability degradation, which is attributed to the Hf-O bond breaking by the high-energy γ-ray exposure.

  1. Analysis of excitation mechanisms of Ho3+ upconversion luminescence in Ho3+:LiYbF4 (0.2 at %) crystal via photographs of its longitudinal cross sections and via spectral and kinetic characteristics

    Science.gov (United States)

    Kazakov, B. N.; Mikheev, A. V.; Goriev, O. G.; Korableva, S. L.; Semashko, V. V.

    2016-10-01

    The results of a complex analysis of the excitation mechanisms of the up conversion luminescence of Ho3+:LiYbF4 (0.2 at %) crystal are presented. The spatial distribution of the upconversion luminescence intensity is studied by the photographs of longitudinal cross sections at different positions of the laser beam waist with respect to the sample. The surface power density of the pump laser diode radiation (0.755 W, λ = 933 nm) was changed by focusing the beam (similar to Z-scanning). The dependences of the longitudinal luminescence cross sections, as well as of the spectral and kinetic characteristics of Ho3+ and Yb3+ luminescence, on the position of the laser beam waist are determined. It is found that there exist two different mechanisms of the population of the energy levels of Ho3+ ions from which green and red luminescence occur, namely, cooperative sensitization of luminescence and absorption of induced photon groups (JETP Letters, 102 (5), 279 (2015)). It is shown that the contributions of these mechanisms vary both in time and over the crystal volume. All the observed spatial, spectral, and temporal specific features of the upconversion luminescence of Ho3+:LiYbF4 (0.2 at %) crystal are qualitatively explained.

  2. Do neighborhood economic characteristics, racial composition, and residential stability predict perceptions of stress associated with the physical and social environment? Findings from a multilevel analysis in Detroit.

    Science.gov (United States)

    Schulz, Amy J; Zenk, Shannon N; Israel, Barbara A; Mentz, Graciela; Stokes, Carmen; Galea, Sandro

    2008-09-01

    As the body of evidence linking disparities in the health of urban residents to disparate social, economic and environmental contexts grows, efforts to delineate the pathways through which broader social and economic inequalities influence health have burgeoned. One hypothesized pathway connects economic and racial and ethnic inequalities to differentials in stress associated with social and physical environments, with subsequent implications for health. Drawing on data from Detroit, Michigan, we examined contributions of neighborhood-level characteristics (e.g., poverty rate, racial and ethnic composition, residential stability) and individual-level characteristics (e.g., age, gender) to perceived social and physical environmental stress. We found that neighborhood percent African American was positively associated with perceptions of both social and physical environmental stress; neighborhood percent poverty and percent Latino were positively associated with perceived physical environmental stress; and neighborhood residential stability was negatively associated with perceived social environmental stress. At the individual level, whites perceived higher levels of both social and physical environmental stress compared to African American residents of the same block groups, after accounting for other variables included in the models. Our findings suggest the importance of understanding and addressing contributions of neighborhood structural characteristics to perceptions of neighborhood stress. The consistency of the finding that neighborhood racial composition and individual-level race influence perceptions of both social and physical environments suggests the continuing importance of understanding the role played by structural conditions and by personal and collective histories that vary systematically by race and ethnicity within the United States.

  3. Hypersonic characteristics of an advanced aerospace plane

    Science.gov (United States)

    Mccandless, R. S.; Cruz, C. I.

    1985-01-01

    A series of hypersonic wind-tunnel tests have been conducted in the NASA Langley Hypersonic Facilities Complex to obtain the static longitudinal and lateral-directional aerodynamic characteristics of an advanced aerospace plane. Data were obtained at 0 to 20 deg angles of attack and -3 to 3 deg angles of sideslip at Mach numbers of 6 and 10 in air and 20 in helium. Results show that stable trim capability exists at angles of attack near maximum lift-drag ratio (L/D). Both performance and stability exhibited some Mach number dependency. The vehicle was longitudinally unstable at low angles of attack but stable at angles of attack near and above maximum L/D. It was directionally unstable with positive dihedral effect. The rudder showed an inability to provide lateral-directional control, and removing the vertical tail resulted in increased directional instability. Analytical predictions of the static longitudinal aerodynamic coefficients gave relatively good comparisons with the experimental data.

  4. 摩擦式缓冲器阻抗特性在列车纵向动力学中的应用%Application of Dynamic Impedance Characteristics of Frictional Draft Gear in Longitudinal Train Dynamics

    Institute of Scientific and Technical Information of China (English)

    齐朝晖; 黄志浩; 孔宪超

    2011-01-01

    The dynamics characteristics of the draft gear determine the longitudinal train dynamics performance to a great extent. The relation between the resistance force and the penetration velocity obtained by traditional methods is not accurate enough. Moreover,the discontinuity with respect to the penetration velocity results in many insurmountable numerical difficulties in the longitudinal train dynamics applications. In this paper, on the basis of the achievement of contact mechanics,the modified model of frictional draft gear characteristics is presented, in which the discontinuity is smoothed according to the method of dealing with the switching effects in the Coulomb s law. The numerical example validates the proposed method.%缓冲器的动力学特性在较大程度上决定着列车纵向动力学性能.传统缓冲器的阻抗特性曲线未能完整描述阻抗力与缓冲器行程变化率之间的关系,并且存在间断点.在列车纵向动力学应用中,引起很多难以克服的困难.本文以摩擦式缓冲器为研究对象,利用接触力学方法,给出阻抗力与缓冲器行程变化率之间的关系;根据处理静摩擦开关效应的相关理论,提出一种处理阻抗力曲线间断点的实用方法.数值算例验证了所提方法的合理性.

  5. Studies on Immature Embryo Culture in vitro in Wheat:Genetic Stability analysis of Somatic variation in main agronomic characteristics

    Institute of Scientific and Technical Information of China (English)

    LiWenxiang; Zenghanbing; 等

    1995-01-01

    The genetic stablility of variations of main agronomic characteristics in progenies from the regenerated plants of immature embryo culture in vitro was studied.The results showed that the variations of earliness in maturity,high 1000-grain weight,plant height and grain weight per spike were heritable and tended to be stable in IE3 and completely stable in IE4,The wide variation of main agronomic characteristics induced by embryo culture in vitro provided the probability of sclection in wheat improvement.Some somaclonal lines with useful variations could be used directly in wheat production.

  6. Health, job characteristics, skills, and social and financial factors in relation to early retirement: results from a longitudinal study in the Netherlands

    NARCIS (Netherlands)

    Wind, A. de; Geuskens, G.A.; Ybema, J.F.; Blatter, B.M.; Burdorf, A.; Bongers, P.M.; Beek, A.J. van der

    2014-01-01

    Objectives This study aimed to investigate the relative contribution of health, job characteristics, skills and knowledge, and social and financial factors to the transition from work to (non-disability) early retirement. Methods Employees aged 59–63 years (N=2317) were selected from the Study on

  7. The Role of Students' Personality Characteristics, Self-Perceived Competence and Learning Conceptions in the Acquisition and Development of Social Communicative Competence: A Longitudinal Study

    Science.gov (United States)

    Bakx, A. W. E. A.; Van der Sanden, J. M. M.; Sijtsma, K.; Croon, M. A.; Vermetten, Y. J. M.

    2006-01-01

    An important purpose of higher social work education is to guide students to acquire and develop social-communicative competencies. The purpose of this study was to investigate the role students' personality characteristics, self-perceived communicative competence and learning conceptions play in the acquisition and development of…

  8. The Longitudinal Effects of Network Characteristics on the Mental Health of Mothers of Children with ASD: The Mediating Role of Parent Cognitions

    Science.gov (United States)

    Benson, Paul R.

    2016-01-01

    Employing a cohort sequential design, the effects of network characteristics on maternal cognitions (perceived social support and parenting self-efficacy) and mental health (depression and well-being) were assessed over 7 years when children with ASD of mothers in the study were age 7-14. Findings indicated that network size, network emotional…

  9. Health, job characteristics, skills, and social and financial factors in relation to early retirement: results from a longitudinal study in the Netherlands

    NARCIS (Netherlands)

    Wind, A. de; Geuskens, G.A.; Ybema, J.F.; Blatter, B.M.; Burdorf, A.; Bongers, P.M.; Beek, A.J. van der

    2014-01-01

    Objectives This study aimed to investigate the relative contribution of health, job characteristics, skills and knowledge, and social and financial factors to the transition from work to (non-disability) early retirement. Methods Employees aged 59–63 years (N=2317) were selected from the Study on Tr

  10. Health, job characteristics, skills, and social and financial factors in relation to early retirement - Results from a longitudinal study in the Netherlands

    NARCIS (Netherlands)

    de Wind, Astrid; Geuskens, Goedele A.; Ybema, Jan Fekke; Blatter, Birgitte M.; Burdorf, Alex; Bongers, Paulien M.; van der Beek, Allard J.

    2014-01-01

    Objective This study aimed to investigate the relative contribution of health, job characteristics, skills and knowledge, and social and financial factors to the transition from work to (non-disability) early retirement. Methods Employees aged 59-63 years (N=2317) were selected from the Study on Tra

  11. Aging Characteristics of PBXN-106E as a Function of Various Stabilizers and the Mixed Energetic Nitroplasticizer BDNPA and BDNPF

    Science.gov (United States)

    1986-08-26

    methane ( irganox 1010 ), 2,4-bis(N-octylthio)-6-(4-hydroxy-3,5-di-t6ertbutylanilino)-1,3,5-triazine ( irganox 565), tris(2,4-di-tert-butylphenyl-phosphite...dinitropropyl)acetal (BDNPA). The PBXN-106E stabilizer study was undertaken to evaluate the use of irganox 565, irganox 1010 , and irgafos 168 (obtained... Irganox 1010 ). tris(2,4-di-tert-butylpehnyl-phosphite (Irgafos 168)--all obtained from Ciba Geigy, 2,2’-methylene-bis-(4-methyl-6-tert-butyl phenol

  12. Relation between Dispersion Characteristics over Surfaces with Dissimilar Roughness and Atmospheric Stability, under Conditions of Equal Geostrophic Winds

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Larsen, Søren Ejling

    1981-01-01

    A simple model was described that related the dispersion of material from ground-level sources at 2 areas, taking into account dissimilarities in the surface roughness parameter (z0) and the atmospheric stability characterized by the Monin-Obukhov length (L). The geostrophic wind speed was assumed...... that travelled a distance x; .hivin.z/L was found when z0/L and x/z0 were known. The model was reduced to 3 dimensionless parameters by merging .hivin.z/L for the 2 areas into a composite parameter. Dimensionless results from the model were illustrated for discrete values of this composite parameter....

  13. Longitudinal analysis reveals characteristically high proportions of bacterial vaginosis-associated bacteria and temporal variability of vaginal microbiota in northern pig-tailed macaques (Macaca leonina).

    Science.gov (United States)

    Zhu, Lin; Lei, Ai-Hua; Zheng, Hong-Yi; Lyu, Long-Bao; Zhang, Zhi-Gang; Zheng, Yong-Tang

    2015-09-18

    The complex and dynamic vaginal microbial ecosystem is critical to both health and disease of the host. Studies focusing on how vaginal microbiota influences HIV-1 infection may face limitations in selecting proper animal models. Given that northern pig-tailed macaques (Macaca leonina) are susceptible to HIV-1 infection, they may be an optimal animal model for elucidating the mechanisms by which vaginal microbiota contributes to resistance and susceptibility to HIV-1 infection. However, little is known about the composition and temporal variability of vaginal microbiota of the northern pig-tailed macaque. Here, we present a comprehensive catalog of the composition and temporal dynamics of vaginal microbiota of two healthy northern pig-tailed macaques over 19 weeks using 454-pyrosequencing of 16S rRNA genes. We found remarkably high proportions of a diverse array of anaerobic bacteria associated with bacterial vaginosis. Atopobium and Sneathia were dominant genera, and interestingly, we demonstrated the presence of Lactobacillus-dominated vaginal microbiota. Moreover, longitudinal analysis demonstrated that the temporal dynamics of the vaginal microbiota were considerably individualized. Finally, network analysis revealed that vaginal pH may influence the temporal dynamics of the vaginal microbiota, suggesting that inter-subject variability of vaginal bacterial communities could be mirrored in inter-subject variation in correlation profiles of species with each other and with vaginal pH over time. Our results suggest that the northern pig-tailed macaque could be an ideal animal model for prospective investigation of the mechanisms by which vaginal microbiota influence susceptibility and resistance to HIV-1 infection in the context of highly polymicrobial and Lactobacillus-dominated states.

  14. Longitudinal analysis reveals characteristically high proportions of bacterial vaginosis-associated bacteria and temporal variability of vaginal microbiota in northern pig-tailed macaques (Macaca leonina)

    Science.gov (United States)

    ZHU, Lin; LEI, Ai-Hua; ZHENG, Hong-Yi; LYU, Long-Bao; ZHANG, Zhi-Gang; ZHENG, Yong-Tang

    2015-01-01

    The complex and dynamic vaginal microbial ecosystem is critical to both health and disease of the host. Studies focusing on how vaginal microbiota influences HIV-1 infection may face limitations in selecting proper animal models. Given that northern pig-tailed macaques (Macaca leonina) are susceptible to HIV-1 infection, they may be an optimal animal model for elucidating the mechanisms by which vaginal microbiota contributes to resistance and susceptibility to HIV-1 infection. However, little is known about the composition and temporal variability of vaginal microbiota of the northern pig-tailed macaque. Here, we present a comprehensive catalog of the composition and temporal dynamics of vaginal microbiota of two healthy northern pig-tailed macaques over 19 weeks using 454-pyrosequencing of 16S rRNA genes. We found remarkably high proportions of a diverse array of anaerobic bacteria associated with bacterial vaginosis. Atopobium and Sneathia were dominant genera, and interestingly, we demonstrated the presence of Lactobacillus-dominated vaginal microbiota. Moreover, longitudinal analysis demonstrated that the temporal dynamics of the vaginal microbiota were considerably individualized. Finally, network analysis revealed that vaginal pH may influence the temporal dynamics of the vaginal microbiota, suggesting that inter-subject variability of vaginal bacterial communities could be mirrored in inter-subject variation in correlation profiles of species with each other and with vaginal pH over time. Our results suggest that the northern pig-tailed macaque could be an ideal animal model for prospective investigation of the mechanisms by which vaginal microbiota influence susceptibility and resistance to HIV-1 infection in the context of highly polymicrobial and Lactobacillus-dominated states. PMID:26452693

  15. Polyacrylamide Gel-Entrapped Fungal Manganese Peroxidase from Ganoderma lucidum IBL-05 with Enhanced Catalytic, Stability, and Reusability Characteristics.

    Science.gov (United States)

    Bilal, Muhammad; Asgher, Muhammad; Iqbal, Hafiz M N

    2016-01-01

    In the present study, polyacrylamide gel (PAG) was utilized as bolster material for the immobilization of in-house extracted and partially purified manganese peroxidase (MnP) through an entrapment technique yielding significant MnP immobilization (87.3±3.3 %) and remarkable stability of the enzyme (37.2±2.4 %) after a storage period of two months at 4°C. The immobilization also increased the optimal temperature by 10 °C and provided an alkaline shift of the pH optimum. Moreover, a significant enhancement in the thermo-stability was observed. After an incubation period of 72 h at 50°C, the PAG-entrapped-MnP still exhibited 41.2 % of the initial activity, whereas the free enzyme was completely inactive. Furthermore, PAG-entrapped-MnP showed an excellent recycling efficiency and retained more than 50% of its initial activity after five consecutive reaction cycles. In conclusion, owing to the economic feasibility, carrier-supported MnP may be a promising candidate for various applications in different industrial sectors.

  16. Design and analysis pertaining to the aerodynamic and stability characteristics of a hybrid wing-body cargo aircraft

    Directory of Open Access Journals (Sweden)

    Ishaan PRAKASH

    2017-09-01

    Full Text Available Recent trends in aircraft design research have resulted in development of many unconventional configurations mostly aimed at improving aerodynamic efficiency. The blended wing body (BWB is one such configuration that holds potential in this regard. In its current form the BWB although promises a better lift to drag (L/D ratio it is still not able to function to its maximum capability due to design modifications such as twist and reflexed airfoils to overcome stability problems in the absence of a tail. This work aims to maximize the impact of a BWB. A design approach of morphing the BWB with a conventional aft fuselage is proposed. Such a configuration intends to impart full freedom to the main wing and the blended forward fuselage to contribute in lift production while the conventional tail makes up for stability. The aft fuselage, meanwhile, also ensures that the aircraft is compatible with current loading and airdrop operations. This paper is the culmination of obtained models results and inferences from the first phase of the project wherein development of aerodynamic design and analysis methodologies and mission specific optimization have been undertaken.

  17. Methods of lab silos sealing and fermentation characteristics and aerobic stability of sugarcane silage treated with microbial additive

    Directory of Open Access Journals (Sweden)

    Charles Ortiz Novinski

    2012-02-01

    Full Text Available The present experimental assay evaluated the effect of lab silo sealing methods on the ensilage of the sugarcane, with or without microbial additives (Lactobacillus plantarum and Propionibacterium acidipropionici. Twenty-liter plastic buckets were used as experimental silos, which were sealed with either a polyethylene sheet (silo cover with a mesh size of 200 µm or an appropriate plastic lid equipped with Bunsen valve. Silos were stored for 30, 60, or 90 days. Fermentative losses, chemical composition, organic acids, ethanol and aerobic stability were evaluated. The sealing method employed did not influence most of evaluated variables, showing a small decrease of effluent production in silos covered with polyethylene sheet. The microbial additive did not avoid dry matter (DM fermentative losses in sugarcane silages (216 g kg-1, nor affected aerobic stability (44.6 hours. The levels of neutral and acid detergent fiber of fresh sugarcane increased after ensiling due to DM losses as gases and effluent. The ethanol content of silages was not influenced by treatments (mean 146 g kg-1 of DM. The sealing methods of experimental silos were not affected by the evaluated variables; polyethylene sheet and plastic lid show the same performance on the fermentative model and both methods represent well the conditions of large scale farm silos.

  18. Stability characteristics of thin film dewetting with insoluble surfactant%含活性剂液膜去润湿演化的稳定性特征

    Institute of Scientific and Technical Information of China (English)

    李春曦; 姜凯; 叶学民

    2013-01-01

    Considering the process of insoluble-surfactant-laden film dewetting on a solid substrate, we have established the base state and disturbance evolution equations for the film thickness and interfacial surfactant concentrations based on the lubrication approximation. Transient growth analysis (TGA) was carried out to investigate the stability characteristics of evolution process, and the effects of intermolecular forces were discussed. Results indicate that the introduction of disturbance wave for k=1 is conducive to enhance the stability of film evolution, and the disturbance energy gradually decays;however, the effect changes unexpectedly with the increment of wave number: when k>2, the stability of dewetting process is deteriorated while disturbance energy grows by degrees and the film flow shows unstable characteristics. Thickening the initial film thickness can effectively improve the stability of film dewetting. Van der Waals force enlarges the disturbance on the film surface and leads to the decline of stability. Conversely, Born force and electrostatic force are propitious for the film evolving stably.%针对含非溶性活性剂的液膜在固体基底上的去润湿过程,基于润滑理论建立了基态和扰动态下液膜厚度和表面活性剂浓度的演化模型,应用非模态理论分析了演化过程的稳定性特征,探讨了分子间力对液膜去润湿过程的影响。研究表明,微扰动波的引入(k=1)有利于液膜去润湿过程的稳定进行,扰动能量逐渐衰减,然而,该效果随着扰动波数的增加而显著改变,k>2时,液膜演化的稳定性反而恶化,扰动能量被逐步放大,演化呈现出非稳定特征。增大初始液膜厚度可以有效改善液膜流动的稳定性。范德华力放大了液膜表面的微扰动,使得液膜演化的稳定性下降;相反, Born斥力和静电斥力具有增强去润湿稳定性的作用。

  19. CHARACTERISTICS ANALYSIS OF DRAGON FRUIT EXTRACT SKIN BETACYANIN OF HYLOCEREUS POLYRHIZUS AND HYLOCEREUS UNDATUS WITH TEST OF STABILITY ORGANOLEPTIC JELLY AS ATLAS MEDIA

    Directory of Open Access Journals (Sweden)

    Tutut Puji Lestari

    2016-03-01

    Full Text Available Dragon fruit Hylocereus polyrhizus and Hylocereus undatus are familiy of cactus, grown in Malang. The high consumption of dragon fruit, have an impact on the fruit skin buildup that simply disposed of as trash. Dragon fruit skin is known to have a source of natural red dye, which is Betacyanin. The purpose of this study was to determine the characteristics of the dragon fruit peel extract Betacyanin Hylocereus polyrhizus and Hylocereus undatus as well as the stability of the organoleptic jelly, which will be developed into a learning materials atlas for class VIII Junior High School. The study was conducted in September-October 2015. The study was conducted in three stages. This type of research phase I and II is True Experimental, and phase III is development. The results of phase I shows that various concentrations of ethanol (70% and 90% have an effect on the characteristics of the extract Betacyanin skin dragon fruit Hylocereus polyrhizus and Hylocereus undatus, but very significant effect on skin extract dragon fruit Hylocereus undatus the treatment of N2, EI at pH 4,5. Later in the phase II study results showed that different concentrations of extracts of the best Betacyanin significantly affect the organoleptic stability of jelly. The results of phase III is the development of phase I and II studies into Atlas media for 8th grade of Junior High School.

  20. Effect of aluminum addition on electrical properties, dielectric characteristics, and its stability of (Pr, Co, Cr, Y)-added zinc oxide-based varistors

    Indian Academy of Sciences (India)

    Choon-W Nahm

    2010-06-01

    The electrical properties, dielectric characteristics, and its stability against d.c. accelerated aging stress of (Pr, Co, Cr, Y)-added zinc oxide-based varistors were investigated for different aluminum concentrations under a sintering temperature of 1280°C. As the aluminum concentration increased, the average grain size () increased in the range of 4.3–5.5 m and the sintered density increased in the range of 5.63–5.67 g/cm3. As the aluminum concentration increased, the breakdown field decreased in the range of 6327–710 V/cm and the maximum nonlinear coefficient (46.9) was obtained for 0.005 mol% in aluminum concentration, further additions impaired the nonlinear properties. As the aluminum concentration increased, the apparent dielectric constant increased in the range of 500.5–1327.4 and dissipation factor increased in the range of 0.00493–0.0724. The varistor added with 0.001 mol% Al exhibited the highest stability for – characteristics in which % 1\\ mA is +1.4% and % is –5.7%, under stress state of 0.95 1\\ mA/150° C/24 h.

  1. Impact of bidentate chelators on lipophilicity, stability, and biodistribution characteristics of cationic 99mTc-nitrido complexes.

    Science.gov (United States)

    Kim, Young-Seung; He, Zhengjie; Hsieh, Wen-Yuan; Liu, Shuang

    2007-01-01

    This report describes synthesis and evaluation of novel cationic 99mTc-nitrido complexes, [99mTcN(L)(PNP)](+) (L = ma, ema, tma, etma and mpo; PNP = PNP5, PNP6, and L6), as potential radiotracers for heart imaging. Cationic complexes [99mTcN(L)(PNP)](+) were prepared in two steps. For example, reaction of succinic dihydrazide with 99mTcO4(-) in the presence of excess stannous chloride and PDTA resulted in the [99mTcN(PDTA)n] intermediate, which then reacted Hmpo and PNP6 at 100 degrees C for 10-15 min to give [99mTcN(mpo)(PNP6)](+) in >90% yield. It was found that bidentate chelators have a significant impact on lipophilicity, solution stability, biodistribution, and metabolic stability of cationic 99mTc-nitrido complexes. The fact that [99mTcN(ema)(PNP6)](+) decomposes rapidly in the presence of cysteine (1 mg/mL) while [99mTcN(etma)(PNP6)](+) and [99mTcN(mpo)(PNP6)](+) remain stable for >6 h under the same conditions strongly suggests that thione-S donors in bidentate chelators increase the solution stability of their cationic 99mTc-nitrido complexes. Biodistribution studies were performed on four cationic 99mTc-nitrido complexes in Sprague-Dawley rats. [99mTcN(etma)(PNP5)](+) is of particular interest due to its high initial heart uptake (1.81 +/- 0.35 %ID/g at 5 min postinjection), and long myocardial retention (1.99 +/- 0.47 %ID/g at 120 min postinjection). The heart/liver ratio of [99mTcN(etma)(PNP5)](+) (6.06 +/- 1.48) at 30 min postinjection is almost identical that of 99mTcN-DBODC5 (6.01 +/- 1.45), and is >2 times better than that of 99mTc-sestamibi (2.90 +/- 0.22). Results from metabolism studies show that [99mTcN(etma)(PNP5)](+) has no significant metabolism in the urine, but it does show significant metabolism in feces samples at 120 min postinjection. Planar imaging studies suggest that [99mTcN(etma)(PNP5)](+) might be able to give clinically useful images of the heart as early as 30 min postinjection. [99mTcN(etma)(PNP5)](+) is a very promising

  2. Risk Attitudes, Sample Selection and Attrition in a Longitudinal Field Experiment

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten Igel

    Longitudinal experiments allow one to compare inferences about behavior over time for the same individuals, and evaluate the temporal stability of latent preferences. But longitudinal experiments entail the possibility of sample selection and sample attrition over time, confounding inferences abo...

  3. Simultaneously enhanced device efficiency, stabilized chromaticity of organic light emitting diodes with lambertian emission characteristic by random convex lenses

    Science.gov (United States)

    Lee, Keunsoo; Lee, Jonghee; Kim, Eunhye; Lee, Jeong-Ik; Cho, Doo-Hee; Lim, Jong Tae; Joo, Chul Woong; Kim, Joo Yeon; Yoo, Seunghyup; Ju, Byeong-Kwon; Moon, Jaehyun

    2016-02-01

    An optical functional film applicable to various lighting devices is demonstrated in this study. The phase separation of two immiscible polymers in a common solvent was used to fabricate the film. In this paper, a self-organized lens-like structure is realized in this manner with optical OLED functional film. For an OLED, there are a few optical drawbacks, including light confinement or viewing angle distortion. By applying the optical film to an OLED, the angular spectra distortion resulting from the designed organic stack which produced the highest efficiency was successfully stabilized, simultaneously enhancing the efficiency of the OLED. We prove the effect of the film on the efficiency of OLEDs through an optical simulation. With the capability to overcome the main drawbacks of OLEDs, we contend that the proposed film can be applied to various lighting devices.

  4. Characteristics and Modification of Non-metallic Inclusions in Titanium-Stabilized AISI 409 Ferritic Stainless Steel

    Science.gov (United States)

    Kruger, Dirk; Garbers-Craig, Andrie

    2017-06-01

    This study describes an investigation into the improvement of castability, final surface quality and formability of titanium-stabilized AISI 409 ferritic stainless steel on an industrial scale. Non-metallic inclusions found in this industrially produced stainless steel were first characterized using SEM-EDS analyses through the INCA-Steel software platform. Inclusions were found to consist of a MgO·Al2O3 spinel core, which acted as heterogeneous nucleation site for titanium solubility products. Plant-scale experiments were conducted to either prevent the formation of spinel, or to modify it by calcium treatment. Modification to spherical dual-phase spinel-liquid matrix inclusions was achieved with calcium addition, which eliminated submerged entry nozzle clogging for this grade. Complete modification to homogeneous liquid calcium aluminates was achieved at high levels of dissolved aluminum. A mechanism was suggested to explain the extent of modification achieved.

  5. Characteristics and Modification of Non-metallic Inclusions in Titanium-Stabilized AISI 409 Ferritic Stainless Steel

    Science.gov (United States)

    Kruger, Dirk; Garbers-Craig, Andrie

    2017-02-01

    This study describes an investigation into the improvement of castability, final surface quality and formability of titanium-stabilized AISI 409 ferritic stainless steel on an industrial scale. Non-metallic inclusions found in this industrially produced stainless steel were first characterized using SEM-EDS analyses through the INCA-Steel software platform. Inclusions were found to consist of a MgO·Al2O3 spinel core, which acted as heterogeneous nucleation site for titanium solubility products. Plant-scale experiments were conducted to either prevent the formation of spinel, or to modify it by calcium treatment. Modification to spherical dual-phase spinel-liquid matrix inclusions was achieved with calcium addition, which eliminated submerged entry nozzle clogging for this grade. Complete modification to homogeneous liquid calcium aluminates was achieved at high levels of dissolved aluminum. A mechanism was suggested to explain the extent of modification achieved.

  6. Influence of ensiling temperature, simulated rainfall, and delayed sealing on fermentation characteristics and aerobic stability of corn silage.

    Science.gov (United States)

    Kim, S C; Adesogan, A T

    2006-08-01

    The aim of this study was to determine how delayed silo sealing, high ensiling temperatures, and rainfall at harvest affect the fermentation and aerobic stability of corn silage. One-half of each of 4 replicated, 6 x 1.5 m plots of a corn hybrid was harvested at 35% dry matter (Dry), and each of the other halves was harvested after they were sprinkled with sufficient water to simulate 4 mm of rainfall (Wet). Six representative (2 kg) subsamples were taken from the Wet and Dry forage piles and ensiled immediately (Prompt). Three hours later, 6 additional representative (2 kg) samples were taken from each pile and ensiled (Delay). Half of the bags from each moisture x sealing time treatment combination were stored for 82 d in a 40 degrees C incubator (Hot) and the other half were stored in a 20 degrees C air-conditioned room (Cool). A 2 (moisture treatments) x 2 (sealing times) x 2 (ensiling temperatures) factorial design with 3 replicates per treatment was used for the study. Wetting the corn silage increased concentrations of NH(3)-N, ethanol, and acetic acid. Ensiling at 40 instead of 20 degrees C increased pH, in vitro digestibility, and concentrations of NH(3)-N, residual water-soluble carbohydrates and acid detergent insoluble crude protein. The higher ensiling temperature also reduced concentrations of neutral and acid detergent fiber and lactic and acetic acid. Delayed sealing reduced concentrations of NH(3)-N and total volatile fatty acids. Wetting, high temperature ensiling, and delayed sealing each reduced yeast counts slightly, and marginally (8 h) increased aerobic stability. Hot-Wet-Delay silages were more stable than other silages but had the lowest lactic to acetic acid ratio, and total volatile fatty acid concentration. This study indicates that the fermentation of corn silage is adversely affected by wet conditions at harvest and high ensiling temperatures, whereas delayed silo sealing for 3 h caused no adverse effects.

  7. Charge Transfer Modulated Self-Assembly in Poly(aryl ether) Dendron Derivatives with Improved Stability and Transport Characteristics.

    Science.gov (United States)

    Satapathy, Sitakanta; Prasad, Edamana

    2016-10-05

    Alteration of native gelation properties of anthracene and pyrene cored first generation poly(aryl ether) dendrons, G1-An and G1-Py, by introducing a common acceptor, 2,4,7-trinitro-9H-fluoren-9-one (TNF), results in forming charge transfer gels in long chain alcoholic solvents. This strategy leads to significant perturbation of optical and electronic properties within the gel matrix. Consequently, a noticeable increase of their electrical conductivities is observed, making these poly(aryl ether) dendron based gels potential candidates for organic electronics. While the dc-conductivity (σ) value for the native gel from G1-An is 2.8 × 10(-4) S m(-1), the value increased 3 times (σ = 8.7 × 10(-4) S m(-1)) for its corresponding charge transfer gel. Further, the dc-conductivity for the native gel self-assembled from G1-Py dramatically enhanced by approximately an order of magnitude from 4.9 × 10(-4) to 1.3 × 10(-3) S m(-1), under the influence of an acceptor. Apart from H-bonding and π···π interactions, charge transfer results in the formation of a robust 3D network of fibers, with improved aspect ratio, providing high thermo-mechanical stability to the gels compared to the native ones. The charge transfer gels self-assembled from G1-An/TNF (1:1) and G1-Py/TNF exhibit a 7.3- and 2.5-fold increase in their yield stress, respectively, compared to their native assemblies. A similar trend follows in the case of their thermal stabilities. This is attributed to the typical bilayer self-assembly of the former which is not present in the case of G1-Py/TNF charge transfer gel. Density functional calculations provide deeper insights accounting for the role of charge transfer interactions in the mode of self-assembly. The 1D potential energy surface for the G1-An/TNF dimer and G1-Py/TNF dimer is found to be 11.8 and 1.9 kcal mol(-1) more stable than their corresponding native gel dimers, G1-An/G1-An and G1-Py/G1-Py, respectively.

  8. Characteristics of a novel polymer gel dosimeter formula for MRI scanning: Dosimetry, toxicity and temporal stability of response.

    Science.gov (United States)

    Abtahi, S M

    2016-09-01

    The present study intended to investigate the composition of a new polymer gel dosimeter. The new composition would be more suitable for a wide range of applications in comparison to polyacrylamide gel dosimeter since its extremely toxic acrylamide has been replaced with less harmful monomer i.e. 2-Acrylamido-2-MethylPropane Sulfonic acid (AMPS). To this end, the PAGAT gel dosimeter formula was used as a basis to test the new formulation of polymer gel dosimeter with a different monomer (AMPS) instead of acrylamide by using the %6T and %50C to the formula. The new formulation was named PAMPSGAT (Poly AMPS, Gelatin and THPC) polymer gel dosimeter. Moreover, the MRI response (R2) of dosimeters was analyzed in terms of different dose range as well as post-irradiation time. The results indicated that the dose-response (R2) of AMPS/Bis had a linear trend over a wide dose range. Furthermore, the results showed an acceptable temporal stability for the new polymer gel dosimeter.

  9. Stability of Hydrated Methylamine: Structural Characteristics and H2N···H–O Hydrogen Bonds

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Sha-Sha; Liu, Yi-Rong; Huang, Teng; Feng, Ya-Juan; Jiang, Shuai; Huang, Wei

    2015-04-23

    Methylamine is the simplest aliphatic amine found in human urine, blood, and tissues. It is thought to play a significant part in central nervous system disturbances observed during renal and hepatic disease. In this work we have investigated the methylamine hydration clusters using a basin hopping (BH) algorithm with the density functional theory (DFT). The results presented herein yield a detailed understanding of the structure and stability for a system consisting of one methylamine molecule and up to seven waters: the most stable geometries arise from a fusion of tetramer or pentamer rings; by the geometrical parameters and topological parameters analysis, the strengths of the H2N···H–O hydrogen bonds of the global minima increase as the sizes of clusters increase, except for n = 5 where there is a slight fluctuation. This work may shed light on the form mechanism of methylamine existing in organisms and the hydration structures of larger molecules containing amino functional groups and their interaction with the water molecules nearby.

  10. Characteristic microbial community of a dry thermophilic methanogenic digester: its long-term stability and change with feeding.

    Science.gov (United States)

    Tang, Yue-Qin; Ji, Pan; Hayashi, Junpei; Koike, Yoji; Wu, Xiao-Lei; Kida, Kenji

    2011-09-01

    Thermophilic dry anaerobic digestion of sludge for cellulose methanization was acclimated at 53 °C for nearly 5 years using a waste paper-based medium. The stability of the microbial community structure and the microbial community responsible for the cellulose methanization were studied by 16S rRNA gene-based clone library analysis. The microbial community structure remained stable during the long-term acclimation period. Hydrogenotrophic methanogens dominated in methanogens and Methanothermobacter, Methanobacterium, Methanoculleus, and Methanosarcina were responsible for the methane production. Bacteria showed relatively high diversity and distributed mainly in the phyla Firmicutes, Bacteroidetes, and Synergistetes. Ninety percent of operational taxonomic units (OTUs) were affiliated with the phylum Firmicutes, indicating the crucial roles of this phylum in the digestion. Relatives of Clostridium stercorarium, Clostridium thermocellum, and Halocella cellulosilytica were dominant cellulose degraders. The acclimated stable sludge was used to treat garbage stillage discharged from a fuel ethanol production process, and the shift of microbial communities with the change of feed was analyzed. Both archaeal and bacterial communities had obviously changed: Methanoculleus spp. and Methanothermobacter spp. and the protein- and fatty acid-degrading bacteria became dominant. Accumulation of ammonia as well as volatile fatty acids led to the inhibition of microbial activity and finally resulted in the deterioration of methane fermentation of the garbage stillage.

  11. Stiffness Characteristics of Joshi’s External Stabilization System under Axial Compression: a Finite Element Method Based Study

    Directory of Open Access Journals (Sweden)

    Rajeev Kumar

    2014-07-01

    Full Text Available A finite element model of fractured tibia with Joshi’s External Stabilizing System (JESS mounted on it was developed using 3D beam elements in the ANSYS software. The model was loaded in axial compression and the average axial stiffness of the model was calculated. The analytical value of axial stiffness was compared with reported experimental value to validate the finite element model. The validated model was used to carry out parametric studies on the model to determine the axial properties of JESS. It was observed that axial stiffness of JESS increased by 58% when k-wire diameter was varied from 2 mm to 4 mm while keeping other geometric configurations of the device constant; however, the axial stiffness of the device does not show any significant improvement when the diameter of medio-lateral pins in diaphyseal hold were increased. The findings should help in understanding the axial properties of JESS so that it can be used judiciously in clinical applications.

  12. Storage stability and physical characteristics of tea-polyphenol-bearing nanoliposomes prepared with milk fat globule membrane phospholipids.

    Science.gov (United States)

    Gülseren, Ibrahim; Corredig, Milena

    2013-04-03

    The objective of this work was to better understand the functional properties of milk phospholipids when used as ingredients to prepare liposomes. Liposomal dispersions (10%) were prepared using high-pressure homogenization, and their physical properties as well as their ability to encapsulate tea polyphenols were investigated. The extent of encapsulation, measured by HPLC, increased with tea polyphenol concentration up to about 4 mg·mL(-1). At polyphenol concentrations ≥ 6 mg·mL(-1), the liposome dispersions were no longer stable. The influence of pH (3-7), storage temperature (room temperature or refrigeration), and addition of sugars (0-15%) were studied for liposomes containing 4 mg·mL(-1) polyphenols. The liposomal dispersions were also stable in the presence of peptides. The storage stability of the systems prepared with milk phospholipids was compared to that of liposomes made with soy phospholipids. Soy liposomes were smaller in size than milk phospholipid liposomes, the encapsulation efficiency was higher, and the extent of release of tea polyphenols during storage was lower for milk phospholipid liposomes compared to soy liposomes. The results suggest that milk phospholipids could be employed to prepare tea-polyphenol-bearing liposomes and that the tea catechins may be incorporated in the milk phospholipid bilayer more efficiently than in the case of a soy phospholipid bilayer.

  13. The Longitudinal Effects of Network Characteristics on the Mental Health of Mothers of Children with ASD: The Mediating Role of Parent Cognitions.

    Science.gov (United States)

    Benson, Paul R

    2016-05-01

    Employing a cohort sequential design, the effects of network characteristics on maternal cognitions (perceived social support and parenting self-efficacy) and mental health (depression and well-being) were assessed over 7 years when children with ASD of mothers in the study were age 7-14. Findings indicated that network size, network emotional support, and network instrumental support were positively related to perceived support, while network availability and emotional support were positively linked to self-efficacy. In addition, network support exerted direct and indirect effects on maternal depression and well-being, with cognitive resources mediating the social network-mental health relationship. Finally, consistent with the support-efficacy model, parenting efficacy partially mediated the effects of perceived support on maternal mental health outcomes. Study findings and implications are discussed.

  14. Effect of different levels of corn steep liquor addition on fermentation characteristics and aerobic stability of fresh rice straw silage

    Directory of Open Access Journals (Sweden)

    Xinxin Li

    2016-12-01

    Full Text Available The object of this study was to determine the proper mixing ratio of fresh rice straw to corn steep liquor (CSL to obtain a high protein content silage feed. The following experimental silages were generated: the control (C1, composed of fresh rice straw without CSL additive, mixed with CSL in the ratios of 4:1 (C4, 3:1 (C3 and 2:1 (C2. Lactic acid bacteria (LAB inoculant was applied at the rate of 50 mL/kg (fresh basis of forage to achieve a final application rate of 1 × 106 cfu/g of fresh matter (FM. Duplicate silos for each treatment were opened after 0, 3, 7, 10, 20, 30, 45 and 60 d for microbiological and chemical analysis. The results showed that the addition of CSL significantly increased crude protein (CP contents, and decreased neutral detergent fiber (NDF and acid detergent fiber (ADF contents of treatments after 60 d of ensiling (P < 0.05. The lactic acid contents in C4 and C3 were significantly higher than that in C1 (P < 0.05. In summary, mixing fresh rice straw with CSL at addition levels of 4:1 (C4 and 3:1 (C3 can improve the fermentation quality and nutrient composition of fresh rice straw silage. However, a large proportion of CSL (C3 had a negative impact on the aerobic stability of fresh rice straw.

  15. Latitudinal and longitudinal variation in aerosol characteristics from Sun photometer and MODIS over the Bay of Bengal and Arabian Sea during ICARB

    Indian Academy of Sciences (India)

    Sumita Kedia; S Ramachandran

    2008-07-01

    Spatial variations in aerosol optical properties as function of latitude and longitude are analysed over the Bay of Bengal and Arabian Sea during ICARB cruise period of March–May 2006 from in situ sun photometer and MODIS (Terra, Aqua) satellite measurements. Monthly mean 550 nm aerosol optical depths (AODs) over the Bay of Bengal and Arabian Sea show an increase from March to May both in spatial extent and magnitude. AODs are found to increase with latitude from 4°N to 20°N over the Bay of Bengal while over Arabian Sea, variations are not significant. Sun photometer and MODIS AODs agree well within ± 1 variation. Bay of Bengal AOD (0.28) is higher than the Arabian Sea (0.24) latitudinally. Aerosol fine mode fraction (FMF) is higher than 0.6 over Bay of Bengal, while FMF in the Arabian Sea is about 0.5. Bay of Bengal (∼1) is higher than the Arabian Sea value of 0.7, suggesting the dominance of fine mode aerosols over Bay of Bengal which is corroborated by higher FMF values over Bay of Bengal. Air back trajectory analyses suggest that aerosols from different source regions contribute differently to the optical characteristics over the Bay of Bengal and Arabian Sea.

  16. Numerical simulations on convective heat transfer characteristics of laminar flow with longitudinal vortex induced by winglets%翼片诱导纵向涡强化层流对流传热数值模拟

    Institute of Scientific and Technical Information of China (English)

    车翠翠; 田茂诚; 冷学礼

    2013-01-01

    3-D numerical simulations were presented for studying the flow structures and convective heat transfer charac-teristics in a cylinder tube embedded with wing-finned vortex generators.In the numerical simulation, the winglet was upstream placed at an angle of 45 to the tube wall and 1/6 of channel was selected for studying due to symmetry.The results showed that two counter-rotating longitudinal vortices were induced downstream the winglet, forming a symmet-ric vortex pair.The flow inner vortex pair was towards the wall while the flow outer vortex pair was backwards the wall.The longitudinal vortex could improve the magnitude of velocity in the radial direction, and the maximum value in near wall region reached 80% of the average mainstream velocity downstream the winglet.As a result, the winglet booted the disturbance of the velocity boundary layer.The improved velocity field could make the temperature field in the tube more uniform.Compared with the smooth tube, the temperature gradient near the wall could improve approxi-mately an order of magnitude.The flow induced by the longitudinal vortex rushed to the wall, which strengthened the convective heat transfer significantly.The maximum value of the local Nu on the wall surface could reach 50 times of the smooth tube.The improved convective heat transfer performance lead by longitudinal vortex enhanced with the Reynolds numbers increasing.%利用三维数值模拟,分析了圆管内添加翼片后流体的流动结构和对流传热特性。模拟中,翼片与壁面呈45°倾斜放置,选取包含1个翼片的1/6通道进行研究。结果表明,翼片可在下游诱导产生2个旋转方向相反的纵向涡,形成对称的涡偶,涡偶外侧为背壁流,内侧为向壁流。纵向涡结构提高了流体在径向上的速度波动,在翼片下游靠近管壁处,最大速度可达到主流平均速度的80%,增强了对速度边界层的扰动。流场的改善使通道内的温度场分布

  17. Microencapsulation of borage oil with blends of milk protein, β-glucan and maltodextrin through spray drying: physicochemical characteristics and stability of the microcapsules.

    Science.gov (United States)

    Li, Ru-Yi; Shi, Yan

    2017-07-07

    Borage oil is a rich commercial source of γ-linolenic acid (18:3n-6). However, borage oil is rich in omega-6 polyunsaturated fatty acids and vulnerable to oxidation. Thus, selecting appropriate wall materials is critical to the encapsulation of borage oil. The present study investigated the influence of wall materials on the physicochemical characteristics and stability of microencapsulated borage oil by spray drying. Blends of milk protein [sodium caseinate (CAS) or whey protein concentrate], β-glucan (GLU) and maltodextrin (MD) were used as the wall materials for encapsulating borage oil. The microencapsulation of borage oil with different wall materials attained high encapsulation efficiencies. The microencapsulated borage oil prepared with CAS-MD achieved the optimal encapsulation efficiency of 96.62%. The oxidative stabilities of borage oil and microencapsulated borage oil were measured by accelerated storage test at 45 °C and 33% relative humidity for 30 days. The microencapsulated borage oil presented lower peroxide values than those of borage oil, and the microcapsules prepared with CAS-10GLU-MD (consisting of CAS 50 g kg(-1) , GLU 100 g kg(-1) and MD 475 g kg(-1) of microencapsulation) conferred borage oil with high protection against lipid oxidation. The results of the present study demonstrate that the CAS-GLU-MD blend is appropriate for microencapsulating borage oil. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  18. Earthworm eco-physiological characteristics and quantification of earthworm feeding in vermifiltration system for sewage sludge stabilization using stable isotopic natural abundance

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaowei; Xing, Meiyan, E-mail: lixiaowei419@163.com; Yang, Jian; Dai, Xiaohu

    2014-07-15

    Highlights: • Earthworm growth biomass and activity decreased with the VF depth. • Earthworm gut microbial communities were dominated by Gammaproteobacteria. • δ{sup 15}N and δ{sup 13}C in earthworms decreased with time, and increased with the VF depth. • Effect of earthworm feeding in enhanced VSS reduction was analyzed quantitatively. • Earthworm feeding had low contribution to the enhanced VSS reduction. - Abstract: Previous studies showed that the presence of earthworm improves treatment performance of vermifilter (VF) for sewage sludge stabilization, but earthworm eco-physiological characteristics and effects in VF were not fully investigated. In this study, earthworm population, enzymatic activity, gut microbial community and stable isotopic abundance were investigated in the VF. Results showed that biomass, average weight, number and alkaline phosphatase activity of the earthworms tended to decrease, while protein content and activities of peroxidase and catalase had an increasing tendency as the VF depth. Earthworm gut microbial communities were dominated by Gammaproteobacteria, and the percentages arrived to 76–92% of the microbial species detected. {sup 15}N and {sup 13}C natural abundance of the earthworms decreased with operation time, and increased as the VF depth. Quantitative analysis using δ{sup 15}N showed that earthworm feeding and earthworm–microorganism interaction were responsible for approximately 21% and 79%, respectively, of the enhanced volatile suspended solid reduction due to the presence of earthworm. The finding provides a quantitative insight into how earthworms influence on sewage sludge stabilization in vermifiltration system.

  19. The i-V curve curve characteristics of burner-stabilized premixed flames: detailed and reduced models

    CERN Document Server

    Han, Jie; Casey, Tiernan A; Bisetti, Fabrizio; Im, Hong G; Chen, Jyh-Yuan

    2016-01-01

    The i-V curve describes the current drawn from a flame as a function of the voltage difference applied across the reaction zone. Since combustion diagnostics and flame control strategies based on electric fields depend on the amount of current drawn from flames, there is significant interest in modeling and understanding i-V curves. We implement and apply a detailed model for the simulation of the production and transport of ions and electrons in one dimensional premixed flames. An analytical reduced model is developed based on the detailed one, and analytical expressions are used to gain insight into the characteristics of the i-V curve for various flame configurations. In order for the reduced model to capture the spatial distribution of the electric field accurately, the concept of a dead zone region, where voltage is constant, is introduced, and a suitable closure for the spatial extent of the dead zone is proposed and validated. The results from the reduced modeling framework are found to be in good agre...

  20. Characteristics and stability of soliton crystals in optical fibres for the purpose of optical frequency comb generation

    Science.gov (United States)

    Zajnulina, M.; Böhm, M.; Bodenmüller, D.; Blow, K.; Boggio, J. M. Chavez; Rieznik, A. A.; Roth, M. M.

    2017-06-01

    We study the properties of a soliton crystal, a bound state of several optical pulses that propagate with a fixed temporal separation through the optical fibres of the proposed approach for generation of optical frequency combs (OFC) for astronomical spectrograph calibration. This approach - also being suitable for subpicosecond pulse generation for other applications - consists of a conventional single-mode fibre and a suitably pumped Erbium-doped fibre. Two continuous-wave lasers are used as light source. The soliton crystal arises out of the initial deeply modulated laser field at low input powers; for higher input powers, it dissolves into free solitons. We study the soliton crystal build-up in the first fibre stage with respect to different fibre parameters (group-velocity dispersion, nonlinearity, and optical losses) and to the light source characteristics (laser frequency separation and intensity difference). We show that the soliton crystal can be described by two quantities, its fundamental frequency and the laser power-threshold at which the crystal dissolves into free solitons. The soliton crystal exhibits features of a linear and nonlinear optical pattern at the same time and is insensitive to the initial laser power fluctuations. We perform our studies using the numerical technique called Soliton Radiation Beat Analysis.

  1. Applied longitudinal analysis

    CERN Document Server

    Fitzmaurice, Garrett M; Ware, James H

    2012-01-01

    Praise for the First Edition "". . . [this book] should be on the shelf of everyone interested in . . . longitudinal data analysis.""-Journal of the American Statistical Association   Features newly developed topics and applications of the analysis of longitudinal data Applied Longitudinal Analysis, Second Edition presents modern methods for analyzing data from longitudinal studies and now features the latest state-of-the-art techniques. The book emphasizes practical, rather than theoretical, aspects of methods for the analysis of diverse types of lo

  2. Wind tunnel test of the 0.015-scale Rockwell International space shuttle vehicle orbiter in the Ames 6 by 6 foot supersonic wind tunnel. [to determine longitudinal and lateral-directional characteristics

    Science.gov (United States)

    Milam, M. D.; Dziubala, T. J.

    1973-01-01

    Experimental investigations were performed in a 6- by 6-Foot Supersonic wind tunnel on a 0.015-scale model of the Rockwell International space shuttle vehicle (SSV) 2A orbiter. The purpose of the test was to investigate the longitudinal and lateral-directional characteristics of the vehicle. In addition, hinge moments were measured on the rudder and elevons. Buffet onset was investigated using wing trailing edge pressures and a strain gauge instrumented panel mounted in the wing. The model was tested through a Mach range from 0.6 to 2.0 at a constant unit Reynolds number of 2.5 million. Pitch runs were made at angles of attack from minus 2 deg to +26 deg with beta = 0 deg and 5 deg; yaw runs were made in the range from minus 5 deg to 10 deg of sideslip at angles of attack of 0 deg and 10 deg. Static pressures were measured at the fuselage base and the trailing edges of the wing and rudder. Boundary layer transition was fixed for some runs using distributed roughness strips.

  3. The Relation between Job Characteristics and Job Engagement of New Science Researchers:A Longitudinal Study%新进科研人员工作特征与工作投入之间关系的纵向研究

    Institute of Scientific and Technical Information of China (English)

    孙灵希; 滕飞

    2013-01-01

    通过对新进科研人员进行跟踪调查以及多层线性模型方法的应用,对新进科研人员工作投入的变化趋势以及工作特征对工作投入的影响进行研究。研究结果表明:(1)新进科研人员刚入职的三年内的工作投入水平存在显著下降趋势;(2)工作特征的任务完整性和工作自主性两因子对工作投入的预测效应显著,而技能多样性、任务重要性、工作反馈三因子的预测效应不显著;(3)工作特征五个因子中,技能多样性、任务完整性、任务重要性对科研人员工作投入主要表现为直接效应,工作自主性、工作反馈更多表现为调节作用。%Data on new science researchers’ job characteristics and job engagement were collected in three years by using UWES and JDS of Chinese context.The study used Hierarchical Linear Model to analyze the changing trends of new sci-ence researchers’job engagement and explore the longitudinal effects of job characteristics on job engagement. Results showed that:(1 )new science researchers’job engagement had dropped significantly in three years;(2)task identity and job autonomy of job characteristics had a significantly positive effect on new science researchers’ job engagement change,but skill variety,task significance and feedback of job characteristics had no significant effect;(3)skill varie-ty,task identity and task significance showed a larger direct effect and job autonomy,and feedback showed a larger moder-ating effect.

  4. The use of autocorrelation analysis in the longitudinal study of mood patterns in depressed patients.

    Science.gov (United States)

    Huba, G J; Lawlor, W G; Stallone, F; Fieve, R R

    1976-02-01

    The statistical method of autocorrelation, commonly used in econometrics and engineering, was applied to the daily mood scores of ten depressive hospital in-patients. The analyses made possible the quantification of two aspects of the longitudinal course of individual patients' psychopathology, the degree of day-to-day stability and the degree of periodicity in mood. Quantification of the degree of day-to-day mood stability yielded wide variations between patients and suggested that patients might be usefully categorized in terms of this characteristic. Mood stability during periods of severe depression was found to be less pronounced than during periods of relatively moderate depression. Furthermore, the existence of 'mini-cycles', cyclical fluctuations in mood of one to two weeks' duration occurring during the course of depressive episodes, was demonstrated in three cases.

  5. Growth characteristic, guest distribution, guest ordering and the stability of urea inclusion compounds with 1-decene, n-decane and mixture of 1-decene and n-decane

    Science.gov (United States)

    Wang, Yan; Ge, Xihui; Zhang, Minqing; Zhu, Huaigong; Zhang, Zijian; Wang, Ming

    2014-01-01

    Growth characteristics of urea inclusion compounds with 1-decene, n-decane and mixture of 1-decene and n-decane (relative mass ratio = 1:1) were studied by CCD high-speed Camera. The present studies show that the speed of UICs growth in tunnel direction is faster than in vertical direction and the length of UICs with 1-decene is shorter than UICs with n-decane, and the length of UICs with mixture is between them due to the influence of the vinyl in 1-decene. The value of R = I(CH2)/I(CH3) and M = I(CHCH2)/I(CH3) in FTIR spectrum of UICs increasing with growth time demonstrates that urea prefers to include n-decane than 1-decene. 13C CP/MAS NMR studies of UICs indicate that the arrangement of 1-decene in UICs is CH3⋯CH3 and CHCH2⋯CH2CH. The arrangement of 1-decene in UICs leads to short chain of UICs with 1-decene in tunnel direction. The 13C CP/MAS NMR spectra of UICs with MIX reveal that there are three different types of arrangement: CH3⋯CH3, CHCH2⋯CH3 and CHCH2⋯CH2CH. The methods of FTIR and DSC were used to test the stability of UICs with different guests. The result shows that UICs with n-decane are stable than UICs with 1-decene. And the stability of UICs with mixture is in the middle.

  6. Effects of air exposure, temperature and additives on fermentation characteristics, yeast count, aerobic stability and volatile organic compounds in corn silage.

    Science.gov (United States)

    Weiss, K; Kroschewski, B; Auerbach, H

    2016-10-01

    Ensiling conditions strongly influence fermentation characteristics, yeast count, and aerobic stability. Numerous volatile organic compounds including esters are produced, which may negatively affect feed intake and animal performance and air quality. In addition to a farm survey, 3 laboratory experiments were carried out to study the effects of air (by delayed sealing or by air infiltration during anaerobic storage), temperature (20 and 35°C), and various types of additives [blends of either sodium benzoate and sodium propionate (SBSP) or of sodium benzoate and potassium sorbate (SBPS); buffered mixture of formic and propionic acids (FAPA); homofermentative inoculant (LAB)]. After additive treatment, chopped whole corn plants were packed into 1.5-L glass jars and stored for several months. For treatments with air infiltration, glass jars with holes in the lid and body were used. The farm survey in 2009 revealed large variation in lactate, acetate, ethanol, n-propanol, and 1,2-propanediol concentrations. Whereas ethyl esters were detected in all silages, the mean ethyl lactate concentrations were higher than those for ethyl acetate (474 vs. 38mg/kg of dry matter). In the ensiling experiments, few unequivocal effects of the tested factors on the analyzed parameters were observed due to many interactions. Delayed ensiling without additives decreased lactic acid production but, in one trial, increased acetic acid and had no effect on ethanol. The effect of delayed sealing on yeast counts and aerobic stability differed widely among experiments. Air infiltration during fermentation tested in one trial did not alter lactic acid production, but resulted in more acetic acid in delayed and more ethanol than in promptly sealed untreated silages. Greater ethanol production was associated with increased yeast numbers. Storage at high temperature resulted in lower lactic acid and n-propanol, and a trend toward reduced ethanol production was observed. The additive FAPA

  7. Parameterized Linear Longitudinal Airship Model

    Science.gov (United States)

    Kulczycki, Eric; Elfes, Alberto; Bayard, David; Quadrelli, Marco; Johnson, Joseph

    2010-01-01

    A parameterized linear mathematical model of the longitudinal dynamics of an airship is undergoing development. This model is intended to be used in designing control systems for future airships that would operate in the atmospheres of Earth and remote planets. Heretofore, the development of linearized models of the longitudinal dynamics of airships has been costly in that it has been necessary to perform extensive flight testing and to use system-identification techniques to construct models that fit the flight-test data. The present model is a generic one that can be relatively easily specialized to approximate the dynamics of specific airships at specific operating points, without need for further system identification, and with significantly less flight testing. The approach taken in the present development is to merge the linearized dynamical equations of an airship with techniques for estimation of aircraft stability derivatives, and to thereby make it possible to construct a linearized dynamical model of the longitudinal dynamics of a specific airship from geometric and aerodynamic data pertaining to that airship. (It is also planned to develop a model of the lateral dynamics by use of the same methods.) All of the aerodynamic data needed to construct the model of a specific airship can be obtained from wind-tunnel testing and computational fluid dynamics

  8. Continuity and change in infants' sleep from 8 to 14 months: a longitudinal actigraphy study.

    Science.gov (United States)

    Scher, Anat

    2012-12-01

    In this report changes and stability in sleep-wake characteristics, at the latter part of infancy, were examined. The sample comprised of 34 healthy infants whose sleep was assessed by means of actigraphy at 8, 10, 12 and 14 months. The results indicated that while sleep schedules did not change significantly from 8 to 14 months, sleep consolidation continued across time. Age 12 months stands out in that sleep disruption was unrelated to whether or not the child was a frequent nightwaker before and/or after the 1st birthday. The findings demonstrate the importance of investigating sleep longitudinally using multiple time scales.

  9. 纵向涡发生器作用下矩形通道内流动换热性能研究%Study on Flow and Heat Transfer Characteristic in Rectangular Channel With Longitudinal Vortex Generator

    Institute of Scientific and Technical Information of China (English)

    唐凌虹; 谭思超; 高璞珍

    2014-01-01

    In this study , the effects of three types of longitudinal vortex generator (LVG) configurations on the flow and heat transfer characteristics in a rectangular channel were investigated and analyzed by field synergy principle .The results show that the temperature of plate fuel assembly can be decreased and the critical heat flux (CHF) of the reactor will be increased .Compared by the performance evaluation parameter ,JF factor ,the results indicate that “common flow up”combined with ellipse pole configura-tion can bring about more enhancement of heat transfer at a modest expense of the addi-tional pressure-loss .%对渐缩式纵向涡发生器与椭圆支柱共同作用下矩形通道内的流动换热性能进行了研究,与渐缩式纵向涡发生器、渐扩式纵向涡发生器和光通道的流动换热性能进行了对比,并利用场协同原理对其换热机理进行了分析。结果表明:纵向涡发生器可增强换热,有利于降低加热板的表面温度,从而提高反应堆堆芯的C H F值。采用JF因子对各矩形通道的综合流动换热性能进行了比较,结果表明,渐缩式纵向涡发生器与椭圆支柱组合结构能以较小的阻力代价得到较大的换热效果,是一种理想的强化换热方式。

  10. Rapid fabrication of superhydrophobic Al/Fe2O3 nanothermite film with excellent energy-release characteristics and long-term storage stability

    Science.gov (United States)

    Ke, Xiang; Zhou, Xiang; Hao, Gaozi; Xiao, Lei; Liu, Jie; Jiang, Wei

    2017-06-01

    One of the challenges for the application of energetic materials is their energy-retaining capabilities after long-term storage. In this study, we report a facile method to fabricate superhydrophobic Al/Fe2O3 nanothermite film by combining electrophoretic deposition and surface modification technologies. Different concentrations of dispersion solvents and additives are investigated to optimize the deposition parameters. Meanwhile, the dependence of deposition rates on nanoparticle concentrations is also studied. The surface morphology and chemical composition are characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. A static contact angles as high as 156° shows the superhydrophobicity of the nanothermite film. Natural and accelerated aging tests are performed and the thermal behavior is analyzed. Thermal analysis shows that the surface modification contributes to significantly improved energy-release characteristics for both fresh and aged samples, which is supposed to be attributed to the preignition reaction between Al2O3 shell and FAS-17. Superhydrophobic Al/Fe2O3 nanothermite film exhibits excellent long-time storage stability with 83.4% of energy left in natural aging test and 60.5% in accelerated aging test. This study is instructive to the practical applications of nanothermites, especially in highly humid environment.

  11. Distinct Expression of Immunoglobulin-Binding Proteins in Shiga Toxin-Producing Escherichia coli Implicates High Protein Stability and a Characteristic Phenotype

    Directory of Open Access Journals (Sweden)

    Dennis Rubin

    2017-04-01

    Full Text Available Several immunoglobulin-binding proteins of Escherichia coli (Eib have been isolated from both non-pathogenic and pathogenic E. coli strains. Shiga toxin (Stx-producing E. coli (STEC contain eibG either as a single gene or in combination with eibC, while other E. coli strains harbour single or multiple eib genes. The Eib proteins bind human immunoglobulins in a non-immune manner and contribute to bacterial chain-like adherence to human epithelial cells. In this study, the EibG expression in several STEC strains was analysed under different environmental conditions. STEC produced high levels of EibG in complex media and lower levels in low-grade and minimal media under static growth conditions. This characteristic was independent on the Eib subtypes. Microscopically, EibG-expressing STEC exhibited chain formation and aggregation in all employed media, while aggregates were only visible after growth in complex medium. Once expressed, EibG proteins demonstrate high stability during prolonged incubation. Our findings indicate that the regulation of the expression of Eib proteins is highly complex, although the protein levels vary among STEC strains. However, positive upregulation conditions generally result in distinct phenotypes of the isolates.

  12. Longitudinal oscillation of launch vehicles

    Science.gov (United States)

    Glaser, R. F.

    1973-01-01

    During powered flight a vehicle may develop longitudinal self-excited oscillations, so-called oscillations, of its structure. The energy supplying the vibration is tapped from the thrust by the activity of the system itself; that is, oscillation of the structure causes oscillation of the propellant system, especially of the pumps. In this way an oscillating thrust can be created that, by a feedback loop, may sustain the structural oscillation under certain circumstances. Two special features of the system proved to be essential for creation of instability. One is the effect of the inherent time interval that the thrust oscillation is lagging behind the structural oscillation. The other is the decreased of system mass caused by the exhausting of gas. The latter feature may cause an initially stable system to become unstable. To examine the stability of the system, a single mass-spring model, which is the result of a one-term Galerkin approach to the equation of motion, has been considered. The Nyquist stability criterion leads to a stability graph that shows the stability conditions in terms of the system parameter and also demonstrates the significance of time lag, feedback magnitude, and loss of mass. An important conclusion can be drawn from the analysis: large relative displacements of the pump-engine masses favor instability. This is also confirmed by flight measurements.

  13. Static and dynamic stability analysis of the space shuttle vehicle-orbiter

    Science.gov (United States)

    Chyu, W. J.; Cavin, R. K.; Erickson, L. L.

    1978-01-01

    The longitudinal static and dynamic stability of a Space Shuttle Vehicle-Orbiter (SSV Orbiter) model is analyzed using the FLEXSTAB computer program. Nonlinear effects are accounted for by application of a correction technique in the FLEXSTAB system; the technique incorporates experimental force and pressure data into the linear aerodynamic theory. A flexible Orbiter model is treated in the static stability analysis for the flight conditions of Mach number 0.9 for rectilinear flight (1 g) and for a pull-up maneuver (2.5 g) at an altitude of 15.24 km. Static stability parameters and structural deformations of the Orbiter are calculated at trim conditions for the dynamic stability analysis, and the characteristics of damping in pitch are investigated for a Mach number range of 0.3 to 1.2. The calculated results for both the static and dynamic stabilities are compared with the available experimental data.

  14. Longitudinal impedance of RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, J. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The longitudinal impedance of the two RHIC rings has been measured using the effect of potential well distortion on longitudinal Schottky measurements. For the blue RHIC ring Im(Z/n) = 1.5±0.2Ω. For the yellow ring Im(Z/n) = 5.4±1Ω.

  15. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    Kristensen, Leif

    1979-01-01

    It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between...

  16. Longitudinal categorical data analysis

    CERN Document Server

    Sutradhar, Brajendra C

    2014-01-01

    This is the first book in longitudinal categorical data analysis with parametric correlation models developed based on dynamic relationships among repeated categorical responses. This book is a natural generalization of the longitudinal binary data analysis to the multinomial data setup with more than two categories. Thus, unlike the existing books on cross-sectional categorical data analysis using log linear models, this book uses multinomial probability models both in cross-sectional and longitudinal setups. A theoretical foundation is provided for the analysis of univariate multinomial responses, by developing models systematically for the cases with no covariates as well as categorical covariates, both in cross-sectional and longitudinal setups. In the longitudinal setup, both stationary and non-stationary covariates are considered. These models have also been extended to the bivariate multinomial setup along with suitable covariates. For the inferences, the book uses the generalized quasi-likelihood as w...

  17. Thermal treatment of stabilized air pollution control residues in a waste incinerator pilot plant. Part 2: Leaching characteristics of bottom ashes.

    Science.gov (United States)

    Baun, Dorthe L; Christensen, Thomas H; Bergfeldt, Brita; Vehlow, Jürgen; Mogensen, Erhardt P B

    2004-02-01

    With the perspective of generating only one solid residue from waste incineration, co-feeding of municipal solid waste and air pollution control residues stabilized by the Ferrox process was investigated in the TAMARA pilot plant incinerator as described in Bergfeldt et al. (Waste Management Research, 22, 49-57, 2004). This paper reports on leaching from the combined bottom ashes. Batch leaching test, pH-static leaching tests, availability tests and column leaching tests were used to characterize the leaching properties. The leaching properties are key information in the context of reuse in construction or in landfilling of the combined residue. In general, the combined bottom ashes had leaching characteristics similar to the reference bottom ash, which contained no APC residue. However, As and Pb showed slightly elevated leaching from the combined bottom ashes, while Cr showed less leaching. The investigated combined bottom ashes had contents of metals comparable to what is expected at steady state after continuous co-feeding of APC residues. Only Cd and Pb were partly volatilized (30-40%) during the incineration process and thus the combined bottom ashes had lower contents of Cd and Pb than expected at steady state. Furthermore, a major loss of Hg was, not surprisingly, seen and co-feeding of Ferrox-products together with municipal solid waste will require dedicated removal of Hg in the flue gas to prevent a build up of Hg in the system. In spite of this, a combined single solid residue from waste incineration seems to be a significant environmental improvement to current technology.

  18. Comparison of Cobra perilaryngeal airway (CobraPLA TM with flexible laryngeal mask airway in terms of device stability and ventilation characteristics in pediatric ophthalmic surgery

    Directory of Open Access Journals (Sweden)

    Rani A Sunder

    2012-01-01

    Full Text Available Background: Supraglottic airway devices play an important role in ophthalmic surgery. The flexible laryngeal mask airway (LMA TM is generally the preferred airway device. However, there are no studies comparing it with the Cobra perilaryngeal airway (CobraPLA TM in pediatric ophthalmic procedures. Aims: To analyze the intraoperative device stability and ability to maintain normocarbia of CobraPLA TM and compare it to that with flexible LMA TM . Materials and Methods: Ninety children of American Society for Anesthesiologists physical status 1 and 2, aged 3-15 years scheduled for elective ophthalmic surgeries were randomly assigned to either the CobraPLA TM or the flexible LMA TM group. After placement of each airway device, oropharyngeal leak pressure (OLP was noted. Adequate seal of the devices was confirmed at an inspired pressure of 15 cm H 2 O and pressure-controlled ventilation was initiated. Device displacement was diagnosed if there was a change in capnograph waveform, audible or palpable gas leak, change in expired tidal volume to 6 kPa, or need to increase inspired pressure to >18 cm H 2 O to maintain normocarbia. Results: Demographic data, duration, and type of surgery in both the groups were similar. A higher incidence of intraoperative device displacement was noted with the CobraPLA TM in comparison to flexible LMA TM (P < 0.001. Incidence of displacement was higher in strabismus surgery (7/12. Insertion characteristics and ventilation parameters were comparable. The OLP was significantly higher in CobraPLA TM group (28 ± 6.8 cm H 2 O compared to the flexible LMA TM group (19.9 ± 4.5 cm H 2 O (P < 0.001. Higher surgeon dissatisfaction (65.9% was seen in the CobraPLA TM group. Conclusion: The high incidence of device displacement and surgeon dissatisfaction make CobraPLA TM a less favorable option than flexible LMA TM in ophthalmic surgery.

  19. Improving stability and curving passing performance for railway vehicles with a variable stiffness MRF rubber joint

    Science.gov (United States)

    Harris, B. J.; Sun, S. S.; Li, W. H.

    2017-03-01

    With the growing need for effective intercity transport, the need for more advanced rail vehicle technology has never been greater. The conflicting primary longitudinal suspension requirements of high speed stability and curving performance limit the development of rail vehicle technology. This paper presents a novel magnetorheological fluid based joint with variable stiffness characteristics for the purpose of overcoming this parameter conflict. Firstly, the joint design and working principle is developed. Following this, a prototype is tested by MTS to characterize its variable stiffness properties under a range of conditions. Lastly, the performance of the proposed MRF rubber joint with regard to improving train stability and curving performance is numerically evaluated.

  20. Analysis of the Relationship Between Dynamic Load Characteristics and Voltage Stability%浅析负荷动态特性与电压稳定性的关系

    Institute of Scientific and Technical Information of China (English)

    廖青华; 张锐

    2011-01-01

    阐述了电压稳定的定义与电压失稳机理,对电压稳定与负荷动态特性的关系进行了定性分析,强调了负荷动态特性在电压稳定分析中的重要作用,指出了目前用于电压稳定分析的动态负荷模型存在的问题,说明建立恰当的动态负荷模型是确保电压稳定分析准确性的关键。%Definition of voltage stability and mechanics of voltage collapse are presented. The relationship between voltage stability and Dynamic Load Characteristics is qualitatively analyzed. The importance of Dynamic Load Characteristics in voltage stability analysis is emphasized. The problems of Dynamic Load model in voltage stability analysis at present are pointed out. Appropriate modeling of Dynamic Load is crucial in accurate voltage stability analysis.

  1. Inequalities in socio-economic characteristics and health and wellbeing of men with and without disabilities: a cross-sectional analysis of the baseline wave of the Australian Longitudinal Study on Male Health

    Directory of Open Access Journals (Sweden)

    Anne M. Kavanagh

    2016-10-01

    Full Text Available Abstract Background Internationally, men with disabilities have higher rates of social and economic disadvantage and poorer health and wellbeing than men without disabilities. No single study has provided comprehensive, population-level information about the magnitude of such differences among adult men using a well-validated instrument to measure disability. Methods We analysed baseline data from Ten to Men – an Australian longitudinal study of male health. Ten to Men used a stratified multi-stage cluster random sample design to recruit a national sample of males aged 10 to 55 years residing in private dwellings. Data were collected between October 2013 and July 2014 from 15,988 males. This analysis was restricted to 18–55 year old participants with data available on age and disability (n = 13,569. We compared the demographic, socio-economic characteristics and health and wellbeing of men with and without disabilities using chi squared tests for proportions and t tests for continuous variables. Linear regression adjusted for age was used to assess the association between disability status and health and wellbeing, which were measured using the SF-12 mental and physical health component scores and the Personal Wellbeing Index. Results Men with disabilities were older and more likely to be born in Australia, speak English at home, be Aboriginal and Torres Strait Islander and were less likely to be married or de facto, or to live in urban areas. They were less likely to have completed secondary school, be employed and live in affordable housing, and were more likely to live on low incomes, in more socio-economically disadvantaged areas, and in rental accommodation and to experience shortages of money. Among employed men, those with disabilities were less likely to be in high skilled jobs, worked less hours on average, and were more likely to report that they would prefer to work more. Men with disabilities had lower levels of social

  2. [Posterior longitudinal ligament ossification: case report].

    Science.gov (United States)

    Tella, Oswaldo Inácio de; Herculano, Marco Antonio; Paiva Neto, Manoel Antonio; Faedo Neto, Atílio; Crosera, João Francisco

    2006-03-01

    Posterior longitudinal ligament ossification of cervical spine is a rare condition among caucasians. A 42 years old japanese patient with progressive walking difficulty was diagnosed with this pathology by CT scan and MRI and treated surgically by an anterior approach with arthrodesis. Pathophysiology, racial prevalence, clinical picture, radiological characteristics and surgical approaches options are revised.

  3. The Stability of Perceived Pubertal Timing across Adolescence

    Science.gov (United States)

    Cance, Jessica Duncan; Ennett, Susan T.; Morgan-Lopez, Antonio A.; Foshee, Vangie A.

    2011-01-01

    It is unknown whether perceived pubertal timing changes as puberty progresses or whether it is an important component of adolescent identity formation that is fixed early in pubertal development. The purpose of this study is to examine the stability of perceived pubertal timing among a school-based sample of rural adolescents aged 11 to 17 (N=6,425; 50% female; 53% White). Two measures of pubertal timing were used, stage-normative, based on the Pubertal Development Scale, a self-report scale of secondary sexual characteristics, and peer-normative, a one-item measure of perceived pubertal timing. Two longitudinal methods were used: one-way random effects ANOVA models and latent class analysis. When calculating intraclass correlation coefficients using the one-way random effects ANOVA models, which is based on the average reliability from one time point to the next, both measures had similar, but poor, stability. In contrast, latent class analysis, which looks at the longitudinal response pattern of each individual and treats deviation from that pattern as measurement error, showed three stable and distinct response patterns for both measures: always early, always on-time, and always late. Study results suggest instability in perceived pubertal timing from one age to the next, but this instability is likely due to measurement error. Thus, it may be necessary to take into account the longitudinal pattern of perceived pubertal timing across adolescence rather than measuring perceived pubertal timing at one point in time. PMID:21983873

  4. Effects of Longitudinal Photons

    CERN Document Server

    Friberg, C; Friberg, Christer; Sjöstrand, Torbjörn

    2000-01-01

    The description of longitudinal photons is far from trivial, and their phenomenological importance is largely unknown. While the cross section for direct interactions is calculable, an even more important contribution could come from resolved states. In the development of our model for the interactions of (real and) virtual photons, we have modeled resolved longitudinal effects by simple multiplicative factors on the resolved transverse-photon contributions. Recently, a first set of parton distributions for longitudinal virtual photons has been presented by Ch\\'yla. We therefore compare their impact on some representative distributions, relative to the simpler approaches.

  5. Motor performance after neonatal extracorporeal membrane oxygenation: a longitudinal evaluation

    NARCIS (Netherlands)

    Cammen-Zijp, M.H. van der; Janssen, A.J.W.M.; Raets, M.M.; Rosmalen, J. van; Govaert, P.; Steiner, K.; Gischler, S.J.; Tibboel, D.; Heijst, A.F.J. van; Ijsselstijn, H.

    2014-01-01

    OBJECTIVE: To assess longitudinally children's motor performance 5 to 12 years after neonatal extracorporeal membrane oxygenation (ECMO) and to evaluate associations between clinical characteristics and motor performance. METHODS: Two hundred fifty-four neonatal ECMO survivors in the Netherlands wer

  6. Longitudinal control effectiveness and entry dynamics of a single-stage-to-orbit vehicle

    Science.gov (United States)

    Vinh, N. X.; Lin, C. F.

    1982-01-01

    The classical theory of flight dynamics for airplane longitudinal stability and control analysis was extended to the case of a hypervelocity reentry vehicle. This includes the elements inherent in supersonic and hypersonic flight such as the influence of the Mach number on aerodynamic characteristics, and the effect of the reaction control system and aerodynamic controls on the trim condition through a wide range of speed. Phugoid motion and angle of attack oscillation for typical cases of cruising flight, ballistic entry, and glide entry are investigated. In each case, closed form solutions for the variations in altitude, flight path angle, speed and angle of attack are obtained. The solutions explicitly display the influence of different regions design parameters and trajectory variables on the stability of the motion.

  7. Role of ADME characteristics in drug discovery and their in silico evaluation: in silico screening of chemicals for their metabolic stability.

    Science.gov (United States)

    Gombar, Vijay K; Silver, Ivin S; Zhao, Zhiyang

    2003-01-01

    Drug discovery is a long, arduous process broadly grouped into disease target identification, target validation, high-throughput identification of "hits" and "leads", lead optimization, and pre-clinical and clinical evaluation. Each area is a vast discipline in itself. However, all but the first two stages involve, to varying degrees, the characterization of absorption, distribution, metabolism, excretion, (ADME), and toxicity (T) of the molecules being pursued as potential drug candidates. Clinical failures of about 50% of the Investigational New Drug (IND) filings are attributed to their inadequate ADMET attributes. It is, therefore, no surprise that, in the current climate of social and regulatory pressure on healthcare costs, the pharmaceutical industry is searching for any means to minimize this attrition. Building mathematical models, called in silico screens, to reliably predict ADMET attributes solely from molecular structure is at the heart of this effort in reducing costs as well as development cycle times. This article reviews the emerging field of in silico evaluation of ADME characteristics. For different approaches that have been employed in this area, a critique of the scope and limitations of their descriptors, statistical methods, and reliability are presented. For instance, are geometry-based descriptors absolutely essential or is lower-level structure quantification equally good? What advantages, if any, do we have for methods like artificial neural networks over the least squares optimization methods with rigorous statistical diagnostics? Is any in silico screen worth application, let alone interpretation, if it is not adequately validated? Once deemed acceptable, what good is an in silico screen if it cannot be made available at the workbench of drug discovery teams distributed across the globe throughout multi-national pharmaceutical companies? These are not mere discussion points, rather this article embarks on the stepwise mechanics of

  8. Studies of the Effect of Load Static Characteristics on Node Static Voltage Stability%负荷静态特性对节点静态电压稳定性影响规律的分析

    Institute of Scientific and Technical Information of China (English)

    傅旭; 付翀丽; 黄明良

    2015-01-01

    The effect of ZIP load characteristics on node static voltage stability is analyzed in detail. It is pointed out that the constant power component in ZIP load determines the degree of static voltage stability of the node. A new index for voltage stability based on locally measurable quantities considering the load static characteristics is presented. A simple calculation method for calculating the Thevenin equivalent parameter is provided. The proposed index is tested on IEEE 57-bus systems, and the simulation results indicate that this index can correctly reflect the effect of load static characteristics on node voltage stability, and the calculation of the Thevenin equivalent parameter is simple, thus it is suitable for the on-line monitoring of static voltage stability.%详细分析ZIP负荷特性对节点静态电压稳定性的影响规律,指出ZIP负荷中的恒定功率分量决定了该节点的静态电压稳定程度,提出一种基于局部测量的计及负荷静态特性的电压稳定指标,并给出一种简单的计算节点戴维南等值参数的计算方法。IEEE 57节点仿真表明所提指标可以很好地考虑负荷静态特性对节点电压稳定性的影响,并且戴维南等值参数计算简单,适合于静态电压稳定的在线监控。

  9. Longitudinal automatic control system for a light weight aircraft

    Directory of Open Access Journals (Sweden)

    Cristian VIDAN

    2016-12-01

    Full Text Available This paper presents the design of an automatic control system for longitudinal axis of a light weight aircraft. To achieve this goal it is important to start from the mathematical model in longitudinal plane and then to determine the steady-state parameters for a given velocity and altitude. Using MATLAB Software the mathematical model in longitudinal plane was linearized and the system transfer functions were obtained. To determine the automatic control design we analyzed the stability of the linearized model for each input. After the stability problem was solved, using MATLAB-Simulink Software we designed the control system architecture and we considered that the objective for a stable flight was to continuously adjust the pitch angle θ through control of elevator and velocity through control of the throttle. Finally, we analyzed the performance of the designed longitudinal control system and the results highlighted in graphs outline that the purpose for which it was designed was fulfilled.

  10. Plutonium inventories for stabilization and stabilized materials

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.K.

    1996-05-01

    The objective of the breakout session was to identify characteristics of materials containing plutonium, the need to stabilize these materials for storage, and plans to accomplish the stabilization activities. All current stabilization activities are driven by the Defense Nuclear Facilities Safety Board Recommendation 94-1 (May 26, 1994) and by the recently completed Plutonium ES&H Vulnerability Assessment (DOE-EH-0415). The Implementation Plan for accomplishing stabilization of plutonium-bearing residues in response to the Recommendation and the Assessment was published by DOE on February 28, 1995. This Implementation Plan (IP) commits to stabilizing problem materials within 3 years, and stabilizing all other materials within 8 years. The IP identifies approximately 20 metric tons of plutonium requiring stabilization and/or repackaging. A further breakdown shows this material to consist of 8.5 metric tons of plutonium metal and alloys, 5.5 metric tons of plutonium as oxide, and 6 metric tons of plutonium as residues. Stabilization of the metal and oxide categories containing greater than 50 weight percent plutonium is covered by DOE Standard {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides{close_quotes} December, 1994 (DOE-STD-3013-94). This standard establishes criteria for safe storage of stabilized plutonium metals and oxides for up to 50 years. Each of the DOE sites and contractors with large plutonium inventories has either started or is preparing to start stabilization activities to meet these criteria.

  11. Longitudinal Magnification Drawing Mistake

    Science.gov (United States)

    Rabal, Héctor; Cap, Nelly; Trivi, Marcelo

    2004-01-01

    Lateral magnification in image formation by positive lenses, mirrors, and dioptrics is usually appropriately developed in most optics textbooks.1-9 However, the image of a three-dimensional object occupies a three-dimensional region of space. The optical system affects both the transverse and the longitudinal dimensions of the object and, in general, does it in different ways. The magnification in the direction of the optical axis (the longitudinal magnification) is seldom treated. In several texts, the concept of longitudinal magnification is not even considered. Symmetrical objects (such as arrows) are used and their images appear laterally inverted. It is not shown how a longitudinally nonsymmetric object is imaged. One of the few books where this subject is well treated is in the textbook by Hecht.10 We have repeatedly verified in our classes that there is some confusion related to this subject. Students tend to believe that the image is longitudinally symmetric with respect to the lens optic center. Some prestigious texts commit the same mistake. In addition, a very nice optics book,11 a catalogue of optical hardware,12 a worldwide scientific magazine,13 a paper in an optics journal,14 and a Spanish encyclopedia,15 for example, have also been found to contain this error in drawing the image of a three-dimensional object formed by a positive lens. In this paper we suggest that the teaching of longitudinal magnification should be done with some care and we include a figure showing a properly drawn image.

  12. Integral Characteristics of Stability of Coal-Water Slurries and Coal-Water Slurries Containing Petrochemicals By Evaluation of Separation Into Layers

    Directory of Open Access Journals (Sweden)

    Dmitrienko Margarita A.

    2016-01-01

    Full Text Available For wide use of coal and oil processing wastes in heat power industry we investigated the structural stability of coal-water slurries (CWS and coal-water slurries containing petrochemicals (CWSP. Three methods of evaluating slurry stability were considered. The method of evaluation of separation (into layers of the slurry was chosen to determine the stability of fuel compositions based on bituminous and brown coal, filter cakes of bituminous coals, waste motor, turbine, transformer, compressor oils, oil, oiled mixture and mazut. The experiments shown, that the addition of waste oils (with mass fraction of 10 % to investigated fuel compositions leads to increase of slurry segmental stability is almost by 2 times.

  13. Nanoemulsions produced by varying the type of emulsifier and oil content: Effect of formulation and process parameters on the characteristics and physical stability

    OpenAIRE

    Đorđević Sanela M.; Cekić Nebojša D.; Isailović Tanja M.; Milić Jela R.; Vuleta Gordana M.; Lazić Miodrag L.; Savić Snežana D.

    2013-01-01

    The aim of the present study was to prepare oil-in-water nanoemulsions stabilized with a novel natural alkyl polyglucoside surfactant and to compare them with corresponding lecithin/polysorbate 80 - based nanoemulsions in terms of physicochemical properties and physical stability. Nanoemulsions were prepared by high pressure homogenization, using 20, 30 and 40% (w/w) medium chain triglyceride as oil phase, and 4, 6 and 8% (w/w) lecithin/polysorbate 80 mixtu...

  14. Longitudinal control laws design for a flying wing aircraft

    OpenAIRE

    Zhu, Yan

    2012-01-01

    This research is concerned with the flight dynamic, pitch flight control and flying qualities assessment for the reference BWB aircraft. It aims to develop the longitudinal control laws which could satisfy the flying and handing qualities over the whole flight envelope with added consideration of centre of gravity (CG) variation. In order to achieve this goal, both the longitudinal stability augmentation system (SAS) and autopilot control laws are studied in this thesis. Usi...

  15. Longitudinal control laws design for a flying wing aircraft

    OpenAIRE

    Zhu, Yan

    2012-01-01

    This research is concerned with the flight dynamic, pitch flight control and flying qualities assessment for the reference BWB aircraft. It aims to develop the longitudinal control laws which could satisfy the flying and handing qualities over the whole flight envelope with added consideration of centre of gravity (CG) variation. In order to achieve this goal, both the longitudinal stability augmentation system (SAS) and autopilot control laws are studied in this thesis. Usi...

  16. Elastic Dynamic Stability of Big-Span Power Transmission Tower Subjected to Seismic Excitations

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hang; LI Li; FANG Qin-han; YE Kun

    2009-01-01

    By combining the time-history response analysis and the eigenvalue buckling analysis,this paper developed a computational procedure to study the elastic dynamic stability of a transmission tower by APDL language in ANSYS.The influences of different input directions of seismic excitations and damping ratio on the elastic dynamic stability of tower were discussed.The following conclusions were obtained:(1) Longitudinal direction of the transmission lines is the worst input direction of seismic excitation for the transmission tower.(2) Dead load has no significant effect on the critical load and the occurrence time of buckling.(3) Vertical input of seismic excitations has no great effect on the dynamic stability of the transmission tower.(4) Damping effect has an influence on the dynamic stability of the transmission tower; however,the inherent characteristics of dynamic buckling is not changed.

  17. Statistical models for stability studies

    OpenAIRE

    Uwimpuhwe, Germaine

    2015-01-01

    Stability studies are conducted at all phases of the drug development cycle, with the main objective of having a stable product on market. In this project we aimed at evaluating if the shelf life could be extended from 24 (current shelf life) to 36 months, quantifying pharmaceutical stability such as shelf life, release limit, degradation rate ( annually and at the end of both shelf lives) and consumer/producer risk. The assay data are longitudinal from 50 different batches, whi...

  18. Tunable Single-Longitudinal-Mode High-Power Fiber Laser

    Directory of Open Access Journals (Sweden)

    Jonas K. Valiunas

    2012-01-01

    Full Text Available We report a novel CW tunable high-power single-longitudinal-mode fiber laser with a linewidth of ∼9 MHz. A tunable fiber Bragg grating provided wavelength selection over a 10 nm range. An all-fiber Fabry-Perot filter was used to increase the longitudinal mode spacing of the laser cavity. An unpumped polarization-maintaining erbium-doped fiber was used inside the cavity to eliminate mode hopping and increase stability. A maximum output power of 300 mW was produced while maintaining single-longitudinal-mode operation.

  19. 大展弦比飞翼布局飞机的三轴稳定特性%Three-axis stability characteristics of flying wing with high aspect ratio

    Institute of Scientific and Technical Information of China (English)

    张子军; 王磊; 王立新; 王晋军

    2012-01-01

    飞翼布局飞机取消了平尾和垂尾,构型的改变和阻力方向舵的使用使其呈现出与常规布局飞机不同的三轴稳定特性.以大展弦比飞翼布局飞机为研究对象,开展了其三轴静、动稳定特性的研究;通过与常规大展弦比飞机进行对比,揭示了飞翼构型参数、典型飞行状态对其稳定性的影响规律;分析了阻力方向舵的偏转对此类飞机稳定性的影响.研究结果表明,大展弦比飞翼布局飞机的本体稳定性存在诸多的不足.%A flying wing cancels horizontal and vertical tails, but the changes of configuration and the use of drag rudder make it differ much from the conventional configuration aircraft in three-axis stability characteristics. The aircraft chosen for the study is a flying wing with high aspect ratio. Its three-axis static and dynamic stability characteristics are studied. Comparing with the conventional configuration aircraft with high aspect ratio, the effects of configuration parameters and typical flight condition on the stabilities of the flying wing are discussed. The impact of the drag rudder on the stabilities of such aircraft types is also analyzed. Results show that there are many deficiencies in the inherent three-axis stabilities of the high aspect ratio flying wing.

  20. Multivariate analysis of longitudinal rates of change.

    Science.gov (United States)

    Bryan, Matthew; Heagerty, Patrick J

    2016-12-10

    Longitudinal data allow direct comparison of the change in patient outcomes associated with treatment or exposure. Frequently, several longitudinal measures are collected that either reflect a common underlying health status, or characterize processes that are influenced in a similar way by covariates such as exposure or demographic characteristics. Statistical methods that can combine multivariate response variables into common measures of covariate effects have been proposed in the literature. Current methods for characterizing the relationship between covariates and the rate of change in multivariate outcomes are limited to select models. For example, 'accelerated time' methods have been developed which assume that covariates rescale time in longitudinal models for disease progression. In this manuscript, we detail an alternative multivariate model formulation that directly structures longitudinal rates of change and that permits a common covariate effect across multiple outcomes. We detail maximum likelihood estimation for a multivariate longitudinal mixed model. We show via asymptotic calculations the potential gain in power that may be achieved with a common analysis of multiple outcomes. We apply the proposed methods to the analysis of a trivariate outcome for infant growth and compare rates of change for HIV infected and uninfected infants. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Colour stability and water-holding capacity of M. longissimus and carcass characteristics in fallow deer (Dama dama grazed on natural pasture or fed barley

    Directory of Open Access Journals (Sweden)

    Eva Wiklund

    2005-03-01

    Full Text Available The effects of feeding regimen on carcass characteristics, meat colour and water-holding capacity of M. longissimus were studied in 24 female fallow deer (Dama dama. All animals were farm raised; twelve were grazed on pasture and twelve were fed barley and a small amount of hay prior to slaughter. The animals were slaughtered at two occasions (during the Southern Hemisphere spring; after 19 weeks of feeding (n=12; 6 grazing and 6 barley fed animals; group 1 and after 24 weeks of feeding (n=12; 6 grazing and 6 barley fed animals; group 2. The barley/hay-fed deer had significantly higher body condition scores and carcass weights than the pasture raised group. No difference in meat ultimate pH values between the treatment groups was recorded. The meat from the pasture raised deer had significantly longer colour display life after 2 and 3 weeks of refrigerated storage (+ 2.0 ºC in vacuum bags. There was no difference in drip loss between the two treatment groups. However, significantly lower drip losses were found in meat from the animals in group 2 compared with the ones in group 1 (P ≤ 0.001. It was concluded that the feeding regimen of the animals is an important factor that contributes to the variation in quality of fresh chilled deer meat (venison, mainly the colour stability and display life of vacuum packaged meat.Abstract in Swedish / Sammanfattning: I denna undersökning ingick 24 dovhjortshindar (Dama dama för att studera effekterna av olika typer av foder (bete och korn på slaktkroppskvalitet samt färg och vattenhållande förmåga i köttet (M. longissimus. Alla djur var uppfödda på en hjortfarm, 12 betade gräs och 12 utfodrades med korn och en liten mängd hö före slakt. Djuren slaktades vid två olika tillfällen (under våren på det södra halvklotet; efter 19 veckors utfodring (n=12; 6 betesdjur och 6 kornfodrade djur; grupp 1 och efter 24 veckors utfodring (n=12; 6 betesdjur och 6 kornfodrade djur; grupp 2. De dovhjortar

  2. Longitudinal analysis of the vaginal microflora in pregnancy suggests that L. crispatus promotes the stability of the normal vaginal microflora and that L. gasseri and/or L. iners are more conducive to the occurrence of abnormal vaginal microflora

    Directory of Open Access Journals (Sweden)

    Temmerman Marleen

    2009-06-01

    Full Text Available Abstract Background Despite their antimicrobial potential, vaginal lactobacilli often fail to retain dominance, resulting in overgrowth of the vagina by other bacteria, as observed with bacterial vaginosis. It remains elusive however to what extent interindividual differences in vaginal Lactobacillus community composition determine the stability of this microflora. In a prospective cohort of pregnant women we studied the stability of the normal vaginal microflora (assessed on Gram stain as a function of the presence of the vaginal Lactobacillus index species (determined through culture and molecular analysis with tRFLP. Results From 100 consecutive Caucasian women vaginal swabs were obtained at mean gestational ages of 8.6 (SD 1.4, 21.2 (SD 1.3, and 32.4 (SD 1.7 weeks, respectively. Based on Gram stain, 77 women had normal or Lactobacillus-dominated vaginal microflora (VMF during the first trimester, of which 18 had grade Ia (L. crispatus cell morphotypes VMF (23.4%, 16 grade Iab (L. crispatus and other Lactobacillus cell morphotypes VMF (20.8%, and 43 grade Ib (non-L. crispatus cell morphotypes VMF (55.8%. Thirteen women with normal VMF at baseline, converted in the second or third trimester (16.9% to abnormal VMF defined as VMF dominated by non-Lactobacillus bacteria. Compared to grade Ia and grade Iab VMF, grade Ib VMF were 10 times (RR = 9.49, 95% CI 1.30 – 69.40 more likely to convert from normal to abnormal VMF (p = 0.009. This was explained by the observation that normal VMF comprising L. gasseri/iners incurred a ten-fold increased risk of conversion to abnormal VMF relative to non-L. gasseri/iners VMF (RR 10.41, 95% CI 1.39–78.12, p = 0.008, whereas normal VMF comprising L. crispatus had a five-fold decreased risk of conversion to abnormal VMF relative to non-L. crispatus VMF (RR 0.20, 95% CI 0.05–0.89, p = 0.04. Conclusion The presence of different Lactobacillus species with the normal vaginal microflora is a major determinant to

  3. Nanoemulsions produced with varied type of emulsifier and oil content: An influence of formulation and process parameters on the characteristics and physical stability

    Directory of Open Access Journals (Sweden)

    Đorđević Sanela M.

    2013-01-01

    Full Text Available The aim of the present study was to prepare oil-in-water nanoemulsions stabilized with a novel natural alkyl polyglucoside surfactant and to compare them with corresponding lecithin/polysorbate 80 - based nanoemulsions in terms of physicochemical properties and physical stability. Nanoemulsions were prepared by high pressure homogenization, using 20, 30 and 40% (w/w medium chain triglyceride as oil phase, and 4, 6 and 8% (w/w lecithin/polysorbate 80 mixture (1/1 or caprylyl/capryl glucoside as emulsifiers. The influence of emulsifier type, emulsifier concentration and oil content was investigated with respect to changes in particle size, particle size distribution, surface charge and physical stability. The influence of production parameters (number of homogenization cycles, type of homogenization process, homogenization pressure on particle size was also investigated. Analysis was performed by photon correlation spectroscopy, laser diffraction, zeta potential, pH and electrical conductivity measurements. All formulations produced revealed a small droplet size ranging from 147 to 228 nm and a very narrow size distribution (polydispersity index range 0,072-0,124. Zeta potentials were about -20 mV and -50 mV for nanoemulsions stabilized with lecithin/polysorbate 80 and caprylyl/capryl glucoside, respectively. The results obtained during the stability studies (6 months at 25°C and 1 month at 40°C indicated that nanoemulsion stability was influenced by their composition. Acquired results also suggested the most appropriate production parameters: 9 homogenization cycles, homogenization pressure of 500 bar and discontinuous process of homogenization.

  4. Axial Liquid Dispersion Characteristics in Magnetically Stabilized Bed%磁稳定床轴向液体分散特性

    Institute of Scientific and Technical Information of China (English)

    张东利; 张艳君; 张金利; 李晓芳; 卢立祥; 孟祥坤; 慕旭宏

    2006-01-01

    Axial liquid dispersion was experimentally studied in liquid-solid and gas-liquid-solid magnetically stabilized beds using the ferromagnetic catalyst of SRNA-4 as the solid phase. The effects of operating factors and fluid characters, such as superficial liquid velocity, superficial gas velocity, magnetic field intensity, liquid viscosity and surface tension, on axial dispersion coefficients of liquid were investigated. The dispersion coefficients increased with the increase of superficial liquid velocity and superficial gas velocity, and decreased with the increase of liquid viscosity, liquid surface tension and magnetic field intensity. A correlation equation of Peclet number was obtained for both liquid-solid and gas-liquid-solid magnetically stabilized bed.

  5. Investigation of longitudinal aerodynamic parameters identification method for fly-by-wire passenger airliners

    Institute of Scientific and Technical Information of China (English)

    Wu Zhao; Wang Lixin; Xu Zijian; Tan Xiangsheng

    2013-01-01

    The flight control system of a fly-by-wire (FBW) passenger airliner with a complex frame-work and high feedback gain augmentation would change the original characteristic of a loaded sig-nal and suppress the excitation of an airplane’s pertinent motion modes. Taking a research example of an FBW passenger airliner model with longitudinal relaxed-static-stability, a new method of signal type selection and signal parameter design is proposed, through analysis of signal energy distribution and plane body’s frequency response. According to CCAR60--the Appraisal and Use Regulation of Flight Simulator Device, the simulation validation of the FBW passenger airliner’s longitudinal aerodynamic parameters identification is put forward. The validation result indicates that the designed signal could excite the longitudinal motion mode of the FBW passenger airliner adequately and the multiparameter comparison in simulation meets the objective test request of CCAR60. Meanwhile, the relative errors of aerodynamic parameters are less than 10%.

  6. Effect of salt and acidic pH on the stability of virulence plasmid (pYV) in Yersinia enterocolitica and expression of virulence-associated characteristics

    Science.gov (United States)

    The stability of the Yersinia enterocolitica virulence plasmid (pYV) under different NaCl concentrations and under acidic pH conditions was investigated. Exposure of five strains representing five serotypes of pYV-bearing virulent Y. enterocolitica to 0.5, 2 and 5% NaCl and under conditions of pH 4...

  7. Primary rotational stability of various megaprostheses in a biomechanical sawbone model with proximal femoral defects extending to the isthmus.

    Directory of Open Access Journals (Sweden)

    Stefan Kinkel

    Full Text Available Fixation of proximal femoral megaprostheses is achieved in the diaphyseal isthmus. We hypothesized that after extended bone resection including the proximal part of the isthmus a reduced length of fixation will affect the stability and fixation characteristics of these megaprostheses. The aim of this study was to analyze in a validated sawbone model with extended proximal femoral defects which types of implants have sufficient primary stability to allow osteointegration and to describe their fixation characteristics.Four different cementless megaprostheses were implanted into 16 Sawbones with an AAOS type III defect after resection 11 cm below the lesser trochanter involving the proximal isthmus. To determine the primary implant stability relative micromotions between bone and implant were measured in relation to a cyclic torque of 7Nm applied on the longitudinal axis of the implant. We determined the fixation characteristics of the different implant designs by comparing these relative micromotions along the longitudinal stem axis.In the tested sawbones all studied implants showed sufficient primary stability to admit bone integration with relative micromotions below 150 µm after adapting our results to physiologic hip joint loadings. Different fixation characteristics of the megaprostheses were determined, which could be explained by their differing design and fixation concepts.Cementless megaprostheses of different designs seem to provide sufficient primary stability to bridge proximal femoral defects if the diaphyseal isthmus is partially preserved. In our sawbone model the different implant fixation patterns can be related to their stem designs. No evidence can be provided to favor one of the studied implants in this setting. However, femoral morphology is variable and in different isthmus configurations specific implant designs might be appropriate to achieve the most favorable primary stability, which enables bone integration and

  8. Diagnostic stability of autism spectrum disorder in toddlers prospectively identified in a community-based setting: Behavioural characteristics and predictors of change over time.

    Science.gov (United States)

    Barbaro, Josephine; Dissanayake, Cheryl

    2016-07-28

    Autism spectrum disorder diagnoses in toddlers have been established as accurate and stable across time in high-risk siblings and clinic-referred samples. Few studies have investigated diagnostic stability in children prospective identified in community-based settings. Furthermore, there is a dearth of evidence on the individual behaviours that predict diagnostic change over time. The stability and change of autism spectrum disorder diagnoses were investigated from 24 to 48 months in 77 children drawn from the Social Attention and Communication Study. Diagnostic stability was high, with 88.3% overall stability and 85.5% autism spectrum disorder stability. The behavioural markers at 24 months that contributed to diagnostic shift off the autism spectrum by 48 months included better eye contact, more directed vocalisations, the integration of gaze and directed vocalisations/gestures and higher non-verbal developmental quotient. These four variables correctly predicted 88.7% of children into the autism spectrum disorder-stable and autism spectrum disorder-crossover groups overall, with excellent prediction for the stable group (96.2%) and modest prediction for the crossover group (44.4%). Furthermore, non-verbal developmental quotient at 24 months accounted for the significant improvement across time in 'Social Affect' scores on the Autism Diagnostic Observation Schedule for both groups and was the only unique predictor of diagnostic crossover. These findings contribute to the body of evidence on the feasibility of diagnoses at earlier ages to facilitate children's access to interventions to promote positive developmental outcomes.

  9. 换热器通道内反向旋转纵向涡间的干涉特性%Interaction characteristics between longitudinal vortices with counter-rotating directions in heat exchanger channel

    Institute of Scientific and Technical Information of China (English)

    宋克伟; 刘松; 王良璧

    2016-01-01

    Longitudinal vortices can enhance heat transfer with small pressure loss penalty and has been widely applied in heat transfer enhancement of tube bank fin heat exchangers. Setting winglet vortex generator (VG) that can generate longitudinal vortices on the fin surface is a promising technique to enhance the airside heat transfer. In order to obtain better heat transfer performance, lots of VGs are punched out of the fin surface, so several longitudinal vortices appear in the flow channel. The interaction of vortices affects the intensity of longitudinal vortices and their effect on heat transfer enhancement. In this paper, the interaction of counter rotating longitudinal vortices generated by winglet VGs is quantitatively analyzed under different transversal distances between VGs. The effects of interaction of vortices on the intensity of vortices, flow field structure and heat transfer are discussed in detail by using the longitudinal vortex intensity parameterSe. The results show that the interaction of counter rotating longitudinal vortices increases with the decrease of transversal distance between VGs. When the distance between VGs is zero, the interaction between counter rotating vortices is the most serious, while the values ofΔSe,ΔNu andΔf get the minimum values. The maximum decreasing percentage ofΔSe,ΔNu andΔf are 45%, 50% and 38%, respectively. The interaction between counter rotating vortices does not necessarily decrease the heat transfer of longitudinal vortices. The heat transfer performance depends on not only the intensity of vortices but also their structure. The common flow region formed between counter rotating longitudinal vortices is beneficial for heat transfer enhancement. Due to the interactions of counter rotating longitudinal vortices and their effect on heat transfer enhancement, an optimum arrangement of VGs exists for better heat transfer performance. The best heat transfer performance can be obtained when the transversal

  10. 纵振换能器式圆筒型超声电机振动特性的研究%Research on the vibration characteristics of cylindrical type ultrasonic motor using longitudinal vibration transducers

    Institute of Scientific and Technical Information of China (English)

    刘英想; 陈维山; 杨小辉; 刘军考

    2012-01-01

    In a previous research, the authors have presented and developed a cylindrical type ultrasonic motor using longitudinal vibration transducers. Four uniform longitudinal vibration transducers are adopted in this motor to excite a bending vibration traveling wave in a cylinder with teeth. The simulation and experiment results of this motor indicate that the vibration state of the transducer is not single longitudinal vibration, but longitudinal and bending coupled vibration. This study focuses the research on the vibration state of the transducer in the previous motor. Firstly, the reason for the bending vibration of the transducer is given. Then, the effect of the coupling bending vibration on the electromechanical coupling factor of the motor and the distortion of traveling wave are studied. The study results state that the coupling bending vibration of the transducer can make the resonance frequency of the stator deviate from the resonance of the transducer and cause a distortion of traveling wave in the cylinder. Finally, new mode to excite the radial bending vibration of a cylinder by using the bending vibration of a transducer is presented.%以纵振夹心换能器式圆筒型超声电机为研究对象,对换能器的振动状态进行了分析,给出了换能器弯曲振动的产生原因;研究了耦生弯振对电机机电耦合系数以及圆筒中弯振行波质量所带来的影响,耦生弯振的存在使得定子模态特征频率偏离换能器谐振频率,并使得定子圆筒中的弯振行波产生了畸变.最后,提出一种采用换能器弯振激励圆筒径向弯振的模态组合方式.

  11. LONGITUDINAL SOLUTIONS IN RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BLASKIEWICZ,M.BRENNAN,J.M.FISCHER,W.CAMERON,P.WEI,J.LUQUE,A.SCHAMEL,H.

    2003-05-12

    Stable, coherent, longitudinal oscillations have been observed in the RHIC accelerator. Within the context of perturbation theory, the beam parameters and machine impedance suggest these oscillations should be Landau damped. When nonlinear effects are included, long lived, stable oscillations become possible for low intensity beams. Simulations and theory are compared with data.

  12. Influence of different sugar cryoprotectants on the stability and physico-chemical characteristics of freeze-dried 5-fluorouracil plurilamellar vesicles

    Directory of Open Access Journals (Sweden)

    Mohamed Mahmoud Nounou

    2005-07-01

    Full Text Available Lyophilization increases the shelf-life of liposomes by preserving it in a dry form as lyophilized cake to be reconstituted with water immediately prior to administration. Aiming at increasing stability and availability of 5-Fluorouracil liposomal products, 5-Fluorouacil Stable Plurilamellar Vesicles were prepared. Freeze dried liposomal dispersions were prepared with or without cryoprotectants. The cryoprotectants used were glucose, mannitol or trehalose in 1, 2 and 4 grams per gram phospholipids. The results showed that lyophilized cake of liposomes without cryoprotectants was compact and difficult to reconstitute, in comparison with fluffy cakes which reconstituted easily and quickly when using cryoprotectants. The percentage of 5-Fluorouracil retained in liposomes freeze-dried without cryoprotectants was 18.29% ± 0.96% and the percentage of 5-Fluorouracil retained in stable plurilamellar vesicles was 31.22% ± 0.62% using 4 grams trehalose as cryoprotectant per gram of lipid. Physico-chemical and release stability studies showed superior potentials of the lyophilized product after reconstitution in comparison to dispersion product. It may be concluded that all tested sugars have cryoprotectant effects that stabilized liposomes in the freeze dried state, where trehalose offered the most superior cryoprotectant effect for freeze dried 5-fluorouracil liposomes.

  13. 基于群特性分析的DC-DC变换器级联系统稳定性判据%Stability Criterion about Cascaded System of DC-DC Converter Based on Their Group Characteristics

    Institute of Scientific and Technical Information of China (English)

    张波

    2012-01-01

    Stability analysis about cascaded system of power converters is an unsolved problem yet, the impedance ratio criteria applied in linear circuits is not suitable for analysis and study on cascaded systems of switched circuit. Therefore, this paper introduces group theory which researches symmetry into analysis of cascaded system of DC-DC converters, defines their group set, discusses their group characteristics, reveals the relationship and physical significance between their group and cascade characteristics. As a result, this paper develops a stability criterion about cascaded system of DC-DC converters based on group characteristics, gives a novel mathematical tool to solve stability problem of cascaded system of DC-DC converters.%电力电子变换器级联的稳定性分析是一个尚未解决的问题,线性电路的阻抗匹配规律不适合开关电路级联系统的分析和研究。为此,论文尝试将研究对称性的基本理论--群论引入到DC-DC变换器级联系统的分析中,试图根据DC-DC变换器级联系统的物理结构,定义基本DC-DC变换器级联系统的群集合.探讨它们的群特性,揭示群特性与级联特性之间的联系及物理意义,由此初步提出一个基于群特性分析的DC-DC变换器级联系统的稳定性判据,为解决DC-DC变换器级联的问题提供一个新的数学工具。

  14. Voltage stability analysis considering the load dynamic characteristics and the voltage control devices; Analisis de estabilidad de voltaje considerando las caracteristicas dinamicas de la carga y dispositivos de control de voltaje

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Alvarez, Enrique

    2001-09-15

    The research work presented in this thesis, is centered in the voltage stability analysis of medium term considering the effect of the load characteristics and its interaction with the voltage control device models in the transmission network. More concretely, a type of load model is defined and studied with desirable characteristics for the study of the voltage stability, the generic load models derived from field tests and from the application of identification techniques and it is analyzed the influence of the application of control systems to improve the system stability margins. Also, alternatives to the power system modeling for the voltage stability study in complex systems are reviewed. In the first place a fundamental analysis of the voltage characteristics and stability in a simplified power system is presented and the method of adopted analysis is introduced. It is shown that the instability phenomenon is manifested as a singular type bifurcation induced from the critical way of voltage when the system is operated under stress conditions. Next, the contribution of the action of the control devices to the stability margin is analyzed and criteria of the stability analyses are deducted based on the study of such mode. Following a linear model of the power system with desirable characteristics for the study of the voltage stability of medium term is proposed and the characteristics of stability in the context of the study of complex systems are interpreted. The proposed analysis tool is based on the physical notion that the behavior of the voltage control systems in the generators is very rapid with regard to the behavior of the load and has its main application in the preliminary study of the voltage stability of medium and long term. From this model, an analytical tool based on the application of techniques of linear analysis is proposed to approach the problem of determination of critical voltage areas and the contribution of control devices to the

  15. Investigation of longitudinal control system for a small hydrofoil boat

    Science.gov (United States)

    Phillips, W. H.; Shaughnessy, J. D.

    1976-01-01

    An analysis of a hydromechanical system for longitudinal control of a small hydrofoil boat is presented. The system incorporates height and acceleration sensors operating flaps on the foils through a mechanical linkage. Effects of some of the system parameters on the stability and response to waves are shown. The results indicate that the system is capable of providing adequate stability, but the response to stern waves at low frequencies is larger than desired.

  16. Executive Functions in Preschool Children With ADHD and DBD : An 18-Month Longitudinal Study

    NARCIS (Netherlands)

    Schoemaker, Kim; Bunte, Tessa; Espy, Kimberly Andrews; Dekovic, Maja; Matthys, Walter

    2014-01-01

    In this longitudinal study, we examined the stability of the association between executive functions and externalizing behavior problems, and the developmental change of executive functions in a predominately clinically diagnosed preschool sample (N = 200). Inhibition and working memory performance

  17. Executive Functions in Preschool Children With ADHD and DBD : An 18-Month Longitudinal Study

    NARCIS (Netherlands)

    Schoemaker, Kim; Bunte, Tessa; Espy, Kimberly Andrews; Dekovic, Maja; Matthys, Walter

    2014-01-01

    In this longitudinal study, we examined the stability of the association between executive functions and externalizing behavior problems, and the developmental change of executive functions in a predominately clinically diagnosed preschool sample (N = 200). Inhibition and working memory performance

  18. Droop Characteristics Effect on Small Signal Stability of Directly Driven Permanent Magnet Wind Power System%下垂特性对直驱永磁风电系统的小扰动稳定影响

    Institute of Scientific and Technical Information of China (English)

    李军军; 吴政球; 谭勋琼

    2011-01-01

    为了研究频率、幅值下垂特性对直驱型永磁风电系统小扰动稳定性的影响,建立了包含永磁同步电机(permanentmagnet synchronous generator,PMSG)的单机无穷大系统小扰动稳定性分析的数学模型;采用最大功率点跟踪控制(maximum power point tracking,MPPT),保证风力发电机输出功率最大;研究了网侧变换器基于下垂特性的控制方案,理论分析表明,下垂特性对系统的小扰动稳定性有较大影响;利用Matlab建模,对系统在不同下垂特性系数条件下进行了时域分析.仿真结果验证了理论分析的正确性,为采用下垂特性控制的直驱型永磁风力发电系统安全稳定的并网运行提供了一些可借鉴的理论依据.%Frequency and magnitude droop characteristics effect on stability of direct-driven permanent magnet wind farm power system were researched, a small signal stability analysis mathematical model of single machine infinite system including permanent magnet synchronous generator (PMSG)was presented; In order to maximize output power, wind power system was controlled by a maximum power point tracking (MPPT) scheme; droop characteristics control scheme of grid side converter was studied, theory analysis shows: droop characteristics have great effect on system small signal stability;a simulation model was built by Matlab, analysis were performed under different slopes of droop characteristics conditions in time domain. Theory analysis was proved, which provides useful theory reference for stable and safe connected operation of direct-driven permanent magnet wind power system base on droop characteristics controlled.

  19. Towards electrical resistivity soundings in eco-engineering: A non-invasive and fast method to model the near-subsurface characteristics on stabilized alpine slopes.

    Science.gov (United States)

    Bast, Alexander; Meyer, Christine; Meier, Wolfgang; Wilcke, Wolfgang; Lüscher, Peter; Graf, Frank; Gärtner, Holger

    2014-05-01

    The observation and monitoring of the aboveground plant development is a common practice in eco-engineering to estimate the plant's influence on the stabilization process. In contrast to this aboveground "sphere", the near subsurface is invisible and therefore difficult to address. To get an impression of the near subsurface and to model slope stability, (soil)samples are taken or a soil profile is dug and root traits (e.g., tensile strength) are determined. Other parameters as rooting depth, root length density, root clustering or the type of root in general are also of interest. However, soil samples or soil profiles only provide limited point-by-point data, alter parts of the study site, and are often time-consuming and expensive. The development of plants results a complex spatial and temporal distribution of the root network along a slope. This network causes shear strength variations and hydrological heterogeneities in the near subsurface within short distances. In contrast to the common point data, geophysical methods provide minimally-invasive, spatial and, via a time-lapse approach (monitoring), also temporal information of the near subsurface conditions. Hence, by measuring physical properties of the near subsurface, the root system, i.e. root distribution and rooting depth can be modeled. Furthermore, if a correlation between root traits and the measured physical properties is determined, the corresponding root trait can be estimated. To test this approach we applied electrical resistivity tomography (ERT) in a subalpine catchment in the Prättigau valley/Eastern Swiss Alps. Different ERT-soundings were conducted using varying electrode spacings (5cm, 25cm, 50cm and 100cm), electrode arrays (Wenner and Wenner-Schlummberger) and locations (eco-engineered slopes, stabilized two, three and 17 years ago; two forest stands of different stand densities). Furthermore, we took soil samples along the electrical profiles, and dug out several soil profiles to

  20. Teacher Stability and Turnover in Los Angeles: The Influence of Teacher and School Characteristics. Los Angeles School Infrastructure Project. Working Paper

    Science.gov (United States)

    Newton, Xiaoxia A.; Rivero, Rosario; Fuller, Bruce; Dauter, Luke

    2011-01-01

    In this paper, we investigate the effects of teacher characteristics and school context on the timing of teachers' decisions to exit schools where they teach. The two-level discrete time survival analysis framework allows for simultaneous examinations of who exits, when, and under what conditions. Our results for a large sample of teachers in the…

  1. Study on Thermal Stability and Energy Characteristics of Propellant for MEMS-SPMT%MEMS-SPMT用推进剂的热稳定性和能量特性研究

    Institute of Scientific and Technical Information of China (English)

    吴素丽; 胡松启; 张斌; 刘迎吉; 徐秋丽

    2011-01-01

    Propellants for MEMS-based solid microthruster should have low thermal stability. The propellant for MEMS-SPMT is a propellant compond of four ingredients, lead styphnate as the main ingredient, nitrocellulose as the hinder, ammonium perchlorate and superfine aluminium powder as additives. The effects of ammonium perchlorate, aluminium powder and nitrocellulose on the thermal stability of lead styphnate and the thermal decomposition characteristics of four propellants were investigated by DSC. The energy characteristics of four propellants with two expansion ratios(area ratios) of the nozzle were evaluated by using CEA software. The results show that: The effects of ammonium perchlorate and aluminium powder on the thermal stability of lead styphnate is little. The nitrocellulose makes the thermal stability of lead styphnate decrease. The thermal stability of the propellants decreases when the the mass ratio of nitrocellulose to ammonium perchlorate increase. The specific impulse of the propellant can be improved in two cases, one is when the mass content of nitrocellulose and ammonium perchlorate increase, the other is when the expansion ratio of the nozzle is enlarged.%以斯蒂芬酸铅作为推进剂的主要组分,硝化棉为粘接剂,通过添加高氯酸铵、细铝粉,得到了可用于MEMS-SPMT的推进剂.采用DSC研究了高氯酸铵、铝粉、硝化棉对斯蒂芬酸铅热稳定性的影响,研究了4种推进剂配方的热解特性,并利用CEA软件进行热力计算,研究了2种喷管扩张比(面积比)下4种推进剂配方的能量特性.结果表明,高氯酸铵和铝对斯蒂芬酸铅的热稳定性无明显影响,硝化棉能降低斯蒂芬酸铅的热稳定性.硝化棉与高氯酸铵质量比大的推进剂热稳定性较低.增加硝化棉、高氯酸铵的质量含量和增大喷管扩张比均能提高推进剂比冲.

  2. Hypersonic characteristics of an advanced aerospace plane at Mach 20.3

    Science.gov (United States)

    Mccandless, R. S.

    1985-01-01

    Wind-tunnel studies have been performed in the Langley Hypersonic Helium Tunnel Facility to obtain static longitudinal and lateral-directional aerodynamic characteristics of an advanced aerospace plane concept. The nominal test conditions are a Mach number of 20.3 and a Reynolds number of 6.8 x 10 to the 6th power per foot at angles of attack from 0 to 25 deg and angles of sideslip of -3 and 0 deg. Stability and control characteristics are obtained for several deflections of the elevators, elevons, and rudder. In addition, a modified canopy is examined. The results indicate that this vehicle is longitudinally stable at angles of attack near the maximum lift-drag ratio. Also, the vehicle is shown to be directionally unstable with positive dihedral effect.

  3. Long-term stability assessment of AlGaN/GaN field effect transistors modified with peptides: Device characteristics vs. surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Rohrbaugh, Nathaniel; Bryan, Isaac; Bryan, Zachary; Collazo, Ramon; Ivanisevic, Albena, E-mail: ivanisevic@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

    2015-09-15

    AlGaN/GaN Field Effect Transistors (FETs) are promising biosensing devices. Functionalization of these devices is explored in this study using an in situ approach with phosphoric acid etchant and a phosphonic acid derivative. Devices are terminated on peptides and soaked in water for up to 168 hrs to examine FETs for both device responses and surface chemistry changes. Measurements demonstrated threshold voltage shifting after the functionalization and soaking processes, but demonstrated stable FET behavior throughout. X-ray photoelectron spectroscopy and atomic force microscopy confirmed peptides attachment to device surfaces before and after water soaking. Results of this work point to the stability of peptide coated functionalized AlGaN/GaN devices in solution and support further research of these devices as disposable, long term, in situ biosensors.

  4. Characteristics of rose hip (Rosa canina L.) cold-pressed oil and its oxidative stability studied by the differential scanning calorimetry method.

    Science.gov (United States)

    Grajzer, Magdalena; Prescha, Anna; Korzonek, Katarzyna; Wojakowska, Anna; Dziadas, Mariusz; Kulma, Anna; Grajeta, Halina

    2015-12-01

    Two new commercially available high linolenic oils, pressed at low temperature from rose hip seeds, were characterised for their composition, quality and DPPH radical scavenging activity. The oxidative stability of oils was assessed using differential scanning calorimetry (DSC). Phytosterols, tocopherols and carotenoids contents were up to 6485.4; 1124.7; and 107.7 mg/kg, respectively. Phenolic compounds determined for the first time in rose hip oil totalled up to 783.55 μg/kg, with a predominant presence of p-coumaric acid methyl ester. Antiradical activity of the oils reached up to 3.00 mM/kg TEAC. The acid, peroxide and p-anisidine values as well as iron and copper contents indicated good quality of the oils. Relatively high protection against oxidative stress in the oils seemed to be a result of their high antioxidant capacity and the level of unsaturation of fatty acids.

  5. Experimental investigation of influence of acid rain on leaching and hydraulic characteristics of cement-based solidified/stabilized lead contaminated clay.

    Science.gov (United States)

    Du, Yan-Jun; Jiang, Ning-Jun; Shen, Shui-Long; Jin, Fei

    2012-07-30

    Remediation of contaminated lands in China urban areas is of great concern. Degradation of construction facilities caused by acid rain is a serious environmental pollution issue in China. This paper presents an investigation of the effects of acid rain on leaching and hydraulic properties of cement-based solidified/stabilized lead contaminated soil. Laboratory tests including infiltration test and soaking test are conducted. It is found that the soil hydraulic conductivity decreases with increase in the pore volume of flow of permeant liquids (acid rain and distilled water). The decreasing rate in the case of the acid rain is lower than that in the case of the distilled water. The soaking test results show that pH and the presence of sulfate ions of acid rain have considerable influence on the leached concentrations and leaching rate of calcium.

  6. Effect of Grid on Characteristics of Stratification Stability in Density Lock%密度锁栅格结构对分层稳定特性影响

    Institute of Scientific and Technical Information of China (English)

    王升飞; 阎昌琪; 谷海峰

    2011-01-01

    对密度锁内流场进行理论分析和实验观察,研究了栅格结构对密度锁分层稳定特性的影响.结果表明:在无分层时,密度锁内为涡旋流动;有分层时,涡旋被限制在分层上方,涡旋与分层相互作用,直至达到平衡;无栅格时,密度锁存在多个平衡点,分层容易从一个平衡点过渡到下个平衡点,很难稳定;有栅格时,分层能较快地达到平衡点,且由于栅格增强了能量耗散,分层界面更靠上.%The research of effect of grid on stratification stability in densi ty lock is carried out, through the theoretical analysis and experimental observation on the flow field in density lock. The results showed that,the flow in density lock is eddy flow; eddy flow is limited to the top of stratification when the stratification exists; the eddy and stratification interacted with each other until equilibrium, there are more than one equilibrium points in density lock without grid, the stratification is hard to stabilize because it will transit to next equilibrium point easily; but it easy to reach stable with the grid, and the stratification interface will higher with grid than without grid because the grid enhanced the energy dissipation.

  7. Ideal Stabilization

    CERN Document Server

    Nesterenko, Mikhail

    2009-01-01

    We define and explore the concept of ideal stabilization. The program is ideally stabilizing if its every state is legitimate. Ideal stabilization allows the specification designer to prescribe with arbitrary degree of precision not only the fault-free program behavior but also its recovery operation. Specifications may or may not mention all possible states. We identify approaches to designing ideal stabilization to both kinds of specifications. For the first kind, we state the necessary condition for an ideally stabilizing solution. On the basis of this condition we prove that there is no ideally stabilizing solution to the leader election problem. We illustrate the utility of the concept by providing examples of well-known programs and proving them ideally stabilizing. Specifically, we prove ideal stabilization of the conflict manager, the alternator, the propagation of information with feedback and the alternating bit protocol.

  8. The stability of elementary school contexts from kindergarten to third grade.

    Science.gov (United States)

    Lowenstein, Amy E; Wolf, Sharon; Gershoff, Elizabeth T; Sexton, Holly R; Raver, C Cybele; Aber, J Lawrence

    2015-08-01

    The nature and measurement of school contexts have been the foci of interest in community, developmental, and school psychology for decades. In this paper, we tested the stability of six elementary school-context factors over time, using a nationally representative and longitudinal sample of schools from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999 (ECLS-K), and systems theories as a conceptual framework. Confirmatory factor analyses and tests of measurement equivalence revealed that six latent factors fit the data equally well across kindergarten, first grade, and third grade: school strain, school safety practices, school academic performance, school instructional resources, positive school climate, and school violence and crime. The factors were highly stable across the early elementary school years, with standardized stability coefficients ranging from .87 to .99 between kindergarten and first grade and from .71 to .98 between the first and third grades. Equivalence in the two sets of stability coefficients was also found across time. Both the magnitude and equivalence of the stability coefficients were robust to the inclusion of five key exogenous school characteristics as covariates in the model. Results suggest that elementary school contexts are remarkably stable over time and shed light on methodological considerations regarding the treatment of school-level measures in analyses that examine links between school context and children's academic and developmental trajectories. Copyright © 2015 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  9. Four-wave mixing stability in hybrid photonic crystal fibers with two zero-dispersion wavelengths.

    Science.gov (United States)

    Sévigny, Benoit; Vanvincq, Olivier; Valentin, Constance; Chen, Na; Quiquempois, Yves; Bouwmans, Géraud

    2013-12-16

    The four-wave mixing process in optical fibers is generally sensitive to dispersion uniformity along the fiber length. However, some specific phase matching conditions show increased robustness to longitudinal fluctuations in fiber dimensions, which affect the dispersion, even for signal and idler wavelengths far from the pump. In this paper, we present the method by which this point is found, how the fiber design characteristics impact on the stable point and demonstrate the stability through propagation simulations using the non-linear Schrödinger equation.

  10. Characteristic Stabilized Nonconforming Finite Element Metho d for the Unsteady Incompressible Navier-Stokes Equations%非定常不可压缩Navier-Stokes方程的特征稳定化非协调有限元方法

    Institute of Scientific and Technical Information of China (English)

    荆菲菲; 苏剑; 张晓旭; 刘小民

    2014-01-01

    数值求解非定常不可压缩Navier-Stokes方程的难点之一在于强烈的非线性容易引发非物理震荡,本文结合可以有效减弱此种震荡的特征线离散方法,基于局部Gauss积分之差的稳定化格式,采用最低等阶非协调混合有限元对NCP1-P1,构造出求解非定常不可压缩Navier-Stokes方程的特征稳定化非协调混合有限元方法。证明了该方法的全离散格式是无条件稳定的,并给出逼近解的相应误差估计。%One of the difficulties for numerical simulation of the unsteady Navier-Stokes equa-tions is the nonlinearity, when characteristic discretization can effectively weaken the non-physical concussion caused by nonlinear form. Based on the local Gauss quadrature, this paper proposes a characteristic stabilized nonconforming finite ele-ment method to solve the unsteady incompressible Navier-Stokes equations, where the characteristic method and lowest equal-order nonconforming pair NCP1-P1 are employed. We obtain the unconditional stability of its full discrete format and the corresponding error analysis of the approximate solutions.

  11. Effects of storage and industrial oilseed extraction methods on the quality and stability characteristics of crude sunflower oil (Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Demirci, M.

    2011-12-01

    Full Text Available The influence of industrial oilseed extraction methods on the quality and stability of crude sunflower oil (pre-pressed, solvent-extracted, full-pressed and mixed oils was studied by means of the determination of free fatty acids, peroxide value, color value, iron, phosphorus, total and individual tocopherol contents, their stability against oxidation (Rancimat induction time and the fatty acid composition with special emphasis on trans fatty acids. In addition, these crude oils were stored for a period of four months at 40 ± 2°C and analyzed at monthly intervals for free fatty acids, peroxide value, and Rancimat induction time to evaluate their storage stability. The results revealed that the crude sunflower oils obtained by the full-pressed extraction method had worse quality and stability parameters than the crude oils obtained by other extraction methods. Tocopherol content showed a drastic decrease with full-pressed extraction. Also, the crude sunflower oils obtained by the full-pressed extraction presented a higher total trans fatty acid content than the others. On the contrary, the solvent extraction method influenced the phosphorus and iron contents more than the others. The results indicated, however, that pre-pressing the oil appeared to be better than other methods. This study suggests that it is absolutely necessary for the vegetable oil industry to reevaluate the full pressing method as well as the solvent extraction conditions used for sunflowerseeds in order to retain both nutritive value and oxidative stability.La influencia de los métodos industriales de extracción de semillas oleaginosas sobre la calidad y la estabilidad de aceites crudos de girasol (pre-prensado, extraídos con disolventes, prensado completo y mezclas de aceites se ha estudiado mediante la determinación de los ácidos grasos libres, índice de peróxidos, valor del color, hierro, fósforo, contenido de tocoferoles totales e individuales, así como su

  12. Van Kampen modes for bunch longitudinal motion

    Energy Technology Data Exchange (ETDEWEB)

    Burov, A.; /Fermilab

    2010-09-01

    Conditions for existence, uniqueness and stability of bunch steady states are considered. For the existence uniqueness problem, simple algebraic equations are derived, showing the result both for the action and Hamiltonian domain distributions. For the stability problem, van Kampen theory is used. Emerging of discrete van Kampen modes show either loss of Landau damping, or instability. This method can be applied for an arbitrary impedance, RF shape and beam distribution function Available areas on intensity-emittance plane are shown for resistive wall wake and single harmonic, bunch shortening and bunch lengthening RF configurations. Language of van Kampen modes is a powerful tool for studying beam stability. Its unique efficiency reveals itself in those complicated cases, when the dielectric function cannot be obtained, as it is for the longitudinal bunch motion. Emergence of a discrete mode means either loss of Landau damping or instability. By definition, the discrete modes lie outside the continuous incoherent spectrum, but they still may stay within the bucket. In the last case, the discrete mode would disappear after a tiny portion of resonant particles would be added. However, if the discrete mode lie outside the bucket, the Landau damping cannot be restored by tiny perturbation of the particle distribution; LLD is called radical in that case. For a given bunch emittance and RF voltage, the intensity is limited either by reduction of the bucket acceptance or by (radical) LLD. In this paper, results are presented for longitudinal bunch stability in weak head-tail approximation and resistive wall impedance; three RF configurations are studied: single harmonic, bunch shortening and bunch lengthening. It is shown that every RF configuration may be preferable, depending on the bunch emittance and intensity.

  13. Supplementary Investigation to Determine the Effects of Center-of-Gravity Position on the Spin, Longitudinal-Trim, and Tumbling Characteristics of a 1/20-Scale Model of the Consolidated Vultee 7002 Airplane (Flying Mock-up of XF-92)

    Science.gov (United States)

    Klinar, Walter J.; Jones, Ira P., Jr.

    1948-01-01

    A supplementary wind-tunnel investigation has been conducted to determine the effect of rearward positions of the center of gravity on the spin, longitudinal-trim, and tumbling characteristics of the 1/20-scale model of the Consolidated Vultee 7002 airplane equipped with the single vertical tail. A few tests were also made with dual vertical tails added to the model. The model was ballasted to represent, the airplane in its approximate design gross weight for two center-of-gravity positions, 3O and 35 percent of the mean aerodynamic chord. The original tests previously reported were for a center-of-gravity position of 24 percent of the mean aerodynamic chord.

  14. Characteristics of recursive backstepping algorithm and active damping of oscillations in feedback linearization for electromechanical system with extended stability analysis and perturbation rejection.

    Science.gov (United States)

    Anand, V; Narendran, R

    2016-09-01

    In this paper, a technique for estimation of state variables and control of a class of electromechanical system is proposed. Initially, an attempt is made on rudimentary pole placement technique for the control of rotor position and angular velocity profiles of Permanent Magnet Stepper Motor. Later, an alternative approach is analyzed using feedback linearization method to reduce the error in tracking performances. A damping control scheme was additionally incorporated into the feedback linearization system in order to nullify the persistent oscillations present in the system. Furthermore, a robust backstepping controller with high efficacy is put forth to enhance the overall performance and to carry out disturbance rejection. The predominant advantage of this control technique is that it does not require the DQ Transformation of the motor dynamics. A Lyapunov candidate was employed to ensure global asymptotical stability criterion. Also, a nonlinear observer is presented to estimate the unknown states namely load torque and rotor angular velocity, even under load uncertainty conditions. Finally, the performances of all the aforementioned control schemes and estimation techniques are compared and analyzed extensively through simulation.

  15. Stability of Strength and Deformation Characteristics of Expanded Polystyrene (EPS within the Time of Long-Term Investigation of Creep Strain under Permanent Compressive Loading

    Directory of Open Access Journals (Sweden)

    Saulius VAITKUS

    2013-05-01

    Full Text Available The results of investigation of strength (s10 %, scr and deformability (E characteristics of expanded polystyrene specimens are presented. The results are based on the short-term compression in the organization of long-term creep study. For the experiments identical specimens stored 5 years at ambient temperature (23 ±2 °C and relative humidity (50 ±5 % as well specimens after removal long-term loading were used. There were established, that difference between experimental values of stress and initial modulus of tested expanded polystyrene specimens with confidence probability P = 90 % (on-sided test is negligible (random.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4442

  16. Water-holding capacity, colour stability and sensory characteristics in meat (M. longissimus dorsi from reindeer fed two different commercial feeds

    Directory of Open Access Journals (Sweden)

    Eva Wiklund

    2011-04-01

    Full Text Available Twenty reindeer calves (age 10 months were included in the study. They were all fed one of two different pelleted feed mixtures ad libitum for two months before slaughter. Ten calves were fed a control diet of conventional pellets (CPD (Renfor Bas, Lantmännen, Holmsund, Sweden and ten calves received pellets enriched with linseed cake (LPD. The reindeer were slaughtered according to standard procedure at Arvidsjaur Renslakt AB, a reindeer slaughter plant in Arvidsjaur, Sweden. At 1 day post mortem, both longissimus dorsi (LD muscles from each carcass were excised. The left LD was used for sensory evaluation and the right LD for colour and water-holding capacity measurements. The right LD was cut in 4 pieces that were randomly allocated to storage times of 1 day, 1, 2, or 3 weeks at + 4 °C. Samples allocated for storage were vacuum packaged. Evaluation of meat colour was carried out after each of the four storage times while drip loss/purge was registered after 1, 2, and 3 weeks storage at + 4 °C. The left LD muscles were vacuum packaged, frozen at -20 °C and kept frozen until preparation for sensory evaluation. No significant differences were found in carcass quality (carcass weight, EUROP carcass conformation and fat scores, meat colour stability and water-holding capacity of LD samples when comparing the two treatment groups LPD and CPD. However, sensory panellists judged samples from LPD fed reindeer to have a tendency (not significant to be more tender (P= 0.06 and juicy (P=0.07 than the meat samples from CPD fed reindeer. No flavour differences were found when comparing meat samples from the two treatment groups.

  17. Artificial wetlands as tools for frog conservation: stability and variability of reproduction characteristics in Sahara frog populations in Tunisian man-made lakes.

    Science.gov (United States)

    Bellakhal, Meher; Neveu, André; Fertouna-Bellakhal, Mouna; Aleya, Lotfi

    2017-09-27

    Amphibian populations are in decline principally due to climate change, environmental contaminants, and the reduction in wetlands. Even though data concerning current population trends are scarce, artificial wetlands appear to play a vital role in amphibian conservation. This study concerns the reproductive biology of the Sahara frog over a 2-year period in four Tunisian man-made lakes. Each month, gonad state (parameters: K, GSI, LCI), fecundity, and fertility of females (using 1227 clutches) were evaluated in the field under controlled conditions. Clutches were present for 110-130 days at two of the sites, but only for 60-80 days at the other two. Maximum egg laying occurred in May, corresponding to the highest point in the gonad somatic index. Clutch densities were higher in the smaller lakes. Female fecundity was in relation to body size; mean clutch fecundity attained 1416 eggs, with no differences observed according to site. Egg fertility varied over a 1-year period, with a maximum in May followed by a decrease when water temperature was at its highest. Eggs were smaller at the beginning of spawning; maximum size was in May, which might explain the higher fertility, but no maternal influence was detected. Embryonic development was strictly dependent on temperature. The population at each site appeared as a small patch within a metapopulation in overall good health, as shown by the relative temporal stability in reproduction variables. Constructed wetlands may therefore play an important role in the conservation of amphibians, especially in semi-arid zones.

  18. New design of longitudinal ultrasonic vibrator for wire drawing

    Science.gov (United States)

    Yang, Yuancai; Yuan, Jiangbo; Liu, Shen; Shan, Xiaobiao

    2017-04-01

    This paper presents a quarter-wave longitudinal vibrator which is applied to ultrasonic assisted wire drawing. The characteristic of this vibrator is only driven by an axially polarized sandwich PZT stack, which converts electrical energy into mechanical vibration energy. The transducer and horn were designed at the same side of the nodal section to achieve greater vibration at the front of the horn. The four-terminal network method was used to design the vibrator. The finite element method (FEM) was adopted to verify the above design and used for the further analysis about the vibration performances of this vibrator. The numberial caculation results match well with the simulation results. The simulation indicates that the resonance frequency of the longitudinal vibration is about 19.6188 kHz and the amplitude of longitudinal vibration at the end of the horn is about 11.48 μm. The present work provides a new longitudinal vibrator for ultrasonic wire drawing.

  19. Coupling of transverse and longitudinal waves in piano strings.

    Science.gov (United States)

    Etchenique, Nikki; Collin, Samantha R; Moore, Thomas R

    2015-04-01

    The existence of longitudinal waves in vibrating piano strings has been previously established, as has their importance in producing the characteristic sound of the piano. Modeling of the coupling between the transverse and longitudinal motion of strings indicates that the amplitude of the longitudinal waves are quadratically related to the transverse displacement of the string, however, experimental verification of this relationship is lacking. In the work reported here this relationship is tested by driving the transverse motion of a piano string at only two frequencies, which simplifies the task of unambiguously identifying the constituent signals. The results indicate that the generally accepted relationship between the transverse motion and the longitudinal motion is valid. It is further shown that this dependence on transverse displacement is a good approximation when a string is excited by the impact of the hammer during normal play.

  20. Impact of vitamin and mineral supplement withdrawal and wheat middling inclusion on finishing pig growth performance, fecal mineral concentration, carcass characteristics, and the nutrient content and oxidative stability of pork.

    Science.gov (United States)

    Shaw, D T; Rozeboom, D W; Hill, G M; Booren, A M; Link, J E

    2002-11-01

    A study was conducted to determine if supplement withdrawal (omission of dietary vitamin and trace mineral premixes and a two-thirds reduction in dietary inorganic phosphorus) for 28 d preslaughter and the feeding of wheat middlings (dietary concentrations of 5, 15, and 30% from weaning to 16, 16 to 28, and 28 kg to slaughter, respectively) affect growth performance, carcass characteristics, and fecal mineral concentrations ofthe pig, as well as the nutrient content and oxidative stability of the longissimus dorsi muscle. Crossbred pigs (n = 64) were blocked by weight and assigned to one of four dietary treatments in a 2 x 2 factorial design (with or without supplement withdrawal, and with or without wheat middlings). Supplement withdrawal and wheat middling inclusion did not influence average daily gain (ADG), average daily feed intake, gain/feed, or carcass traits, except for a decrease (P pigs from 28 to 65 kg when fed wheat middlings. Supplement withdrawal decreased (P mineral supplementation, wheat middling inclusion decreased (P Supplement withdrawal decreased (P 0.05) longissimus dorsi Ca, P, Fe, and Zn concentrations. Dietary treatment did not affect either Cu/Zn superoxide dismutase or glutathione peroxidase activity in the longissimus dorsi. The results from this study indicate that supplement withdrawal and dietary wheat middling inclusion alter pork nutrient content and fecal mineral concentration, but not the oxidative stability of pork.

  1. Influence of Photovoltaic Micro-Source Characteristics on Voltage Stability of the Series Micro-Grid%光伏微源特性对串联型微网电压稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    杨维满; 王兴贵

    2013-01-01

    The influences of photovoltaic micro-source characteristics on voltage stability of the series micro-grids (SMGs), whose inverters are connected in series, are analyzed. Firstly the system architecture of SMGs is analyzed; then a photovoltaic array model under complex environment is established and the relations between output voltage of SMGs and micro-source dc link voltages are discussed; finally the influencing mechanism of micro-source characteristics on output voltage of SMGs is analyzed in detail, and a voltage stability control strategy of SMGs based on hybrid energy storage is researched. The validity of the proposed control strategy is verified by results of simulation and experiments.%针对微源逆变器串联连接的微网系统,分析了光伏微源特性对串联型微网(series micro-grids,SMGs)系统电压稳定性的影响。首先分析了系统结构;其次建立了复杂环境条件下光伏阵列模型,讨论了各微源直流链电压与系统输出电压之间的关系;最后分析了微源特性对 SMGs 输出电压的影响机理,并研究了基于混合储能的稳定性控制策略。算例结果验证了该控制策略的有效性。

  2. Stability characteristics and structural properties of single- and double-walled boron-nitride nanotubes under physical adsorption of Flavin mononucleotide (FMN) in aqueous environment using molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, R., E-mail: r_ansari@guilan.ac.ir; Ajori, S., E-mail: Shahram_ajori1366@yahoo.com; Ameri, A.

    2016-03-15

    Graphical abstract: Structural properties and stability characteristics of single- and double-walled boron-nitride nanotubes functionalized with Flavin mononucleotide (FMN) in aqueous environment are investigated employing molecular dynamics simulations. - Highlights: • Structural and buckling analysis of boron-nitride nanotubes under physical adsorption of Flavin mononucleotide (FMN). • Gyration radius increases linearly as the weight percentage of FMN increases. • Presence of water molecules results in more expansion of FMN around BNNTs. • Critical buckling force of functionalized BNNTs is higher than that of pure BNNTs. • The critical strain of functionalized BNNTs is found to be lower than that of pure ones. - Abstract: The non-cytotoxic properties of Boron-nitride nanotubes (BNNTs) and the ability of stable interaction with biomolecules make them so promising for biological applications. In this research, molecular dynamics (MD) simulations are performed to investigate the structural properties and stability characteristics of single- and double-walled BNNTs under physical adsorption of Flavin mononucleotide (FMN) in vacuum and aqueous environments. According to the simulation results, gyration radius increases by rising the weight percentage of FMN. Also, the results demonstrate that critical buckling force of functionalized BNNTs increases in vacuum. Moreover, it is observed that by increasing the weight percentage of FMN, critical force of functionalized BNNTs rises. By contrast, critical strain reduces by functionalization of BNNTs in vacuum. Considering the aqueous environment, it is observed that gyration radius and critical buckling force of functionalized BNNTs increase more considerably than those of functionalized BNNTs in vacuum, whereas the critical strains approximately remain unchanged.

  3. Longitudinal data assessment of global stability index in kale leaves

    National Research Council Canada - National Science Library

    Azevedo, Alcinei Mistico; Andrade Júnior, Valter Carvalho de; Pedrosa, Carlos Enrrik; Valadares, Nermy Ribeiro; Ferreira, Marcos Aurélio Miranda; Cecon, Paulo Roberto

    2016-01-01

    ABSTRACT Kale plants are usually sold "in natura" in street markets and malls. Kale leaves can have their appearance compromised by dehydration and discoloration due to increased post-harvest time exposure...

  4. Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia

    Science.gov (United States)

    Peterson, Robin L.; Pennington, Bruce F.; Olson, Richard K.; Wadsworth, Sally J.

    2014-01-01

    Limited evidence supports the external validity of the distinction between developmental phonological and surface dyslexia. We previously identified children ages 8 to 13 meeting criteria for these subtypes (Peterson, Pennington, & Olson, 2013) and now report on their reading and related skills approximately 5 years later. Longitudinal…

  5. Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia

    Science.gov (United States)

    Peterson, Robin L.; Pennington, Bruce F.; Olson, Richard K.; Wadsworth, Sally J.

    2014-01-01

    Limited evidence supports the external validity of the distinction between developmental phonological and surface dyslexia. We previously identified children ages 8 to 13 meeting criteria for these subtypes (Peterson, Pennington, & Olson, 2013) and now report on their reading and related skills approximately 5 years later. Longitudinal…

  6. Temporal Stability, Correlates, and Longitudinal Outcomes of Career Indecision Factors

    Science.gov (United States)

    Nauta, Margaret M.

    2012-01-01

    A confirmatory factor analysis (CFA) tested the fit of Kelly and Lee's six-factor model of career decision problems among 188 college students. The six-factor model did not fit the data well, but a five-factor (Lack of Information, Need for Information, Trait Indecision, Disagreement with Others, and Choice Anxiety) model did provide a good fit.…

  7. Catalytic characteristics and stability of thiol protease from Hayward kiwifruit%海沃德猕猴桃巯基蛋白酶的催化特性

    Institute of Scientific and Technical Information of China (English)

    张倩; 陈彦; 林晓艳; 林金凤

    2012-01-01

    对以海沃德猕猴桃残次果提取的巯基蛋白酶进行了动力学研究,考察了一些外加剂对酶活的影响,同时初步探讨了酶液的稳定性。结果表明:以酪蛋白为底物的猕猴桃巯基蛋白酶的K。值为6.56×10^-3mmol,Vmax为163.93mg·mL^-1·min;在其底物浓度为1.O∥L时,该酶的最适温度和pH分别为55℃和5.5;L-半胱氨酸、2一巯基乙醇、硫代硫酸钠、EDTA以及葡萄糖等外加剂对酶具有明显的激活效果,且EDTA的激活作用最强;抗坏血酸、碘乙酸和过氧化氢等外加剂对酶则具有抑制作用。在最适酶促反应条件下,于4℃温度存放的酶液活性随时间延长呈急剧的降低,并以pH为3.5存放条件下的降低最少,约可保存80%的酶活性。%The kinetics of thiol protease(TP)from defective Hayward fruits were investigated, as well as the impact of some additives on the activity and stability of enzyme solution.The results showed that Km value of TP was 6.56 x 10-3 mmol, casein as substrate,and its Vmax was 163.93mg · mL -1· min-1 .The optimum conditions of TP reactions were 55℃ and pH 5.5 at L0g/L casein concentration.The additives such as L-cysteine, 2-mercaptoethanol (2-ME), sodium thiosulfate, EDTA and glucose had significant promotion effect on TP activity, among which EDTA exhibited the best activation.However,the addition of ascorbic acid (AA), iodoacetic acid and hydrogen peroxide had inhibitory effect.Under the optimum enzymatic reaction conditions, the activity of protease had a sharp drop when storage time of protease solution increased at 4cC.The drop was least when pH was 3.5, and about 80% of the activity could still be reserved.

  8. Risk Attitudes, Sample Selection and Attrition in a Longitudinal Field Experiment

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten Igel

    Longitudinal experiments allow one to compare inferences about behavior over time for the same individuals, and evaluate the temporal stability of latent preferences. But longitudinal experiments entail the possibility of sample selection and sample attrition over time, confounding inferences about...... to findings of temporal stability in overall risk aversion. However, that stability is around different levels of risk aversion than one might naively infer without the controls for sample selection and attrition we are able to implement. This evidence of “randomization bias” from sample selection...... is important given the popularity of field experiments that rely on randomization, and the effects that risk attitudes have for economic behavior in general....

  9. Identity Formation in Adolescence: Change or Stability?

    Science.gov (United States)

    Klimstra, Theo A.; Hale, William W., III; Raaijmakers, Quinten A. W.; Branje, Susan J. T.; Meeus, Wim H. J.

    2010-01-01

    The aim of this five-wave longitudinal study of 923 early to middle adolescents (50.7% boys; 49.3% girls) and 390 middle to late adolescents (43.3% boys and 56.7% girls) is to provide a comprehensive view on change and stability in identity formation from ages 12 to 20. Several types of change and stability (i.e., mean-level change, rank-order…

  10. Automatic stabilization of velocity for ultrasonic vibration system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Describes the structure of a current feedback ultrasonicgeneration system with such characteristic as velocity stabilization and automatic frequency tracking, discusses the velocity stabilization principle, and points out that successful frequency tracking is precondition for velocity stabilization.

  11. On Fitting Nonlinear Latent Curve Models to Multiple Variables Measured Longitudinally

    Science.gov (United States)

    Blozis, Shelley A.

    2007-01-01

    This article shows how nonlinear latent curve models may be fitted for simultaneous analysis of multiple variables measured longitudinally using Mx statistical software. Longitudinal studies often involve observation of several variables across time with interest in the associations between change characteristics of different variables measured…

  12. Stability Functions

    CERN Document Server

    Burns, Daniel; Wang, Zuoqin

    2008-01-01

    In this article we discuss the role of stability functions in geometric invariant theory and apply stability function techniques to problems in toric geometry. In particular we show how one can use these techniques to recover results of Burns-Guillemin-Uribe and Shiffman-Tate-Zelditch on asymptotic properties of sections of holomorphic line bundles over toric varieties.

  13. Longitudinal measurement of physical activity following kidney transplantation.

    NARCIS (Netherlands)

    Dontje, M.L.; Greef, M.H. de; Krijnen, W.P.; Corpeleijn, E.; Kok, T.; Bakker, S.J.; Stolk, R.P.; Schans, C.P. van der

    2014-01-01

    purpose of this longitudinal observational study was to (i) examine the change of daily physical activity in 28 adult kidney transplant recipients over the first 12 months following transplantation; and (ii) to examine the change in metabolic characteristics and renal function. Accelerometer-based d

  14. Sensitivity Analysis of Mixed Models for Incomplete Longitudinal Data

    Science.gov (United States)

    Xu, Shu; Blozis, Shelley A.

    2011-01-01

    Mixed models are used for the analysis of data measured over time to study population-level change and individual differences in change characteristics. Linear and nonlinear functions may be used to describe a longitudinal response, individuals need not be observed at the same time points, and missing data, assumed to be missing at random (MAR),…

  15. A Bayesian Approach for Analyzing Longitudinal Structural Equation Models

    Science.gov (United States)

    Song, Xin-Yuan; Lu, Zhao-Hua; Hser, Yih-Ing; Lee, Sik-Yum

    2011-01-01

    This article considers a Bayesian approach for analyzing a longitudinal 2-level nonlinear structural equation model with covariates, and mixed continuous and ordered categorical variables. The first-level model is formulated for measures taken at each time point nested within individuals for investigating their characteristics that are dynamically…

  16. A Longitudinal Study of Children's Social Adjustment during Elementary School.

    Science.gov (United States)

    Battistich, Victor; Solomon, Daniel

    A 7-year, longitudinal study of children's social development from kindergarten through sixth grade was designed to identify unusually prosocial children and characteristics that differentiated them from average and antisocial peers. Another objective was to identify functional socioemotional predictors of changes in children's social adjustment.…

  17. Study on modeling of vehicle dynamic stability and control technique

    Institute of Scientific and Technical Information of China (English)

    GAO Yun-ting; LI Pan-feng

    2012-01-01

    In order to solve the problem of enhancing the vehicle driving stability and safety,which has been the hot question researched by scientific and engineering in the vehicle industry,the new control method was investigated.After the analysis of tire moving characteristics and the vehicle stress analysis,the tire model based on the extension pacejka magic formula which combined longitudinal motion and lateral motion was developed and a nonlinear vehicle dynamical stability model with seven freedoms was made.A new model reference adaptive control project which made the slip angle and yaw rate of vehicle body as the output and feedback variable in adjusting the torque of vehicle body to control the vehicle stability was designed.A simulation model was also built in Matlab/Simulink to evaluate this control project.It was made up of many mathematical subsystem models mainly including the tire model module,the yaw moment calculation module,the center of mass parameter calculation module,tire parameter calculation module of multiple and so forth.The severe lane change simulation result shows that this vehicle model and the model reference adaptive control method have an excellent performance.

  18. Entrepreneurship and Employment Stability

    DEFF Research Database (Denmark)

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke

    2017-01-01

    are identified and empirically explored: (i) job matching, (ii) labour market value, and (iii) personal commitment. Entrepreneurs appear to be more productive and thus better matched compared to wageworkers. However, they also appear to be locked in entrepreneurship because of their anticipated lower value...... in the labour market and because of their personal attachment to the venture. The counter-intuitive finding – entrepreneurship yields greater employment stability – only holds with respect to subsequent transitions to wagework and not for new venture founding. The results have implications for our understanding......This paper challenges the conventional belief that entrepreneurship is an unstable career path. Using longitudinal matched employer–employee data from Denmark, the analysis reveals that a transition to entrepreneurship decreases individual's employment turnover tendency. Three explanations...

  19. Ensuring Stability

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    "Stable"will be a key word for China’s economy in 2012.That’s the beat set at the annual Central Economic Work Conference held in Beijing on December 12-14,which reviewed this year’s development and mapped out plans for the next year.Policymakers at the conference decided to keep macroeconomic policies stable,seek a stable and relatively fast economic growth,stabilize consumer prices and maintain social stability in 2012.On the basis of stability,the government will transform the development model,deepen reform and improve people’s livelihood.

  20. A Longitudinal Study of Objectively Measured Built Environment as Determinant of Physical Activity in Young Adults

    DEFF Research Database (Denmark)

    Schipperijn, Jasper; Ried-Larsen, Mathias; Nielsen, Merete S;

    2015-01-01

    BACKGROUND: This longitudinal study aimed to examine if a Moveability Index (MI), based on objectively measured built environment characteristics, was a determinant for objectively measured physical activity (PA) among young adults. METHOD: Data collected from 177 persons participating...