WorldWideScience

Sample records for high angle-of-attack flying

  1. Non-linear Flight Dynamics at High Angles of Attack

    DEFF Research Database (Denmark)

    Granasy, P.; Sørensen, C.B.; Mosekilde, Erik

    1998-01-01

    The methods of nonlinear dynamics are applied to the longitudinal motion of a vectored thrust aircraft, in particular the behavior at high angles of attack. Our model contains analytic nonlinear aerodynamical coefficients based on NASA windtunnel experiments on the F-18 high-alpha research vehicle...... (HARV). When the aircraft is forced with small thrust deflections whilst in poststall equilibrium, chaotic motion is observed at certain frequencies. At other frequencies, several limiting states coexist....

  2. High angle of attack aerodynamics subsonic, transonic, and supersonic flows

    CERN Document Server

    Rom, Josef

    1992-01-01

    The aerodynamics of aircraft at high angles of attack is a subject which is being pursued diligently, because the modern agile fighter aircraft and many of the current generation of missiles must perform well at very high incidence, near and beyond stall. However, a comprehensive presentation of the methods and results applicable to the studies of the complex aerodynamics at high angle of attack has not been covered in monographs or textbooks. This book is not the usual textbook in that it goes beyond just presenting the basic theoretical and experimental know-how, since it contains reference material to practical calculation methods and technical and experimental results which can be useful to the practicing aerospace engineers and scientists. It can certainly be used as a text and reference book for graduate courses on subjects related to high angles of attack aerodynamics and for topics related to three-dimensional separation in viscous flow courses. In addition, the book is addressed to the aerodynamicist...

  3. Surface pressure model for simple delta wings at high angles of attack

    Indian Academy of Sciences (India)

    A A Pashilkar

    2001-12-01

    A new aerodynamic modelling approach is proposed for the longitudinal static characteristics of a simple delta wing. It captures the static variation of normal force and pitching moment characteristics throughout the angle of attack range. The pressure model is based on parametrizing the surface pressure distribution on a simple delta wing. The model is then extended to a wing/body combination where body-alone data are also available. The model is shown to be simple and consistent with experimental data. The pressure model can be used as a first approximation for the load estimation on the delta wing at high angles of attack.

  4. Magnus effects at high angles of attack and critical Reynolds numbers

    Science.gov (United States)

    Seginer, A.; Ringel, M.

    1983-01-01

    The Magnus force and moment experienced by a yawed, spinning cylinder were studied experimentally in low speed and subsonic flows at high angles of attack and critical Reynolds numbers. Flow-field visualization aided in describing a flow model that divides the Magnus phenomenon into a subcritical region, where reverse Magnus loads are experienced, and a supercritical region where these loads are not encountered. The roles of the spin rate, angle of attack, and crossflow Reynolds number in determining the boundaries of the subcritical region and the variations of the Magnus loads were studied.

  5. Bifurcation analysis of polynomial models for longitudinal motion at high angle of attack

    Institute of Scientific and Technical Information of China (English)

    Shi Zhongke; Fan Li

    2013-01-01

    To investigate the longitudinal motion stability of aircraft maneuvers conveniently,a new stability analysis approach is presented in this paper.Based on describing longitudinal aerodynamics at high angle-of-attack (α < 50°) motion by polynomials,a union structure of two-order differential equation is suggested.By means of nonlinear theory and method,analytical and global bifurcation analyses of the polynomial differential systems are provided for the study of the nonlinear phenomena of high angle-of-attack flight.Applying the theories of bifurcations,many kinds of bifurcations,such as equilibrium,Hopf,homoclinic (heteroclinic) orbit and double limit cycle bifurcations are discussed and the existence conditions for these bifurcations as well as formulas for calculating bifurcation curves are derived.The bifurcation curves divide the parameter plane into several regions; moreover,the complete bifurcation diagrams and phase portraits in different regions are obtained.Finally,our conclusions are applied to analyzing the stability and bifurcations of a practical example of a high angle-of-attack flight as well as the effects of elevator deflection on the asymptotic stability regions of equilibrium.The model and analytical methods presented in this paper can be used to study the nonlinear flight dynamic of longitudinal stall at high angle of attack.

  6. Wing-Alone Aerodynamic Characteristics to High Angles of Attack at Subsonic and Transonic Speeds.

    Science.gov (United States)

    1982-11-01

    indicators of symmetry since the wings were unbanked within the limits of tolerances and flow angularity. Longitudinal, spanwise, and vertical... unbanked wings at subsonic and transonic speeds from low to high angles of attack. The wing planforms varied in aspect ratio and taper ratio with

  7. COMPUTATION OF FIELD STRUCTURE AND AERODYNAMIC CHARACTERISTICS OF DELTA WINGS AT HIGH ANGLES OF ATTACK

    Institute of Scientific and Technical Information of China (English)

    YANG Li-zhi; GAO Zheng-hong

    2005-01-01

    A numerical investigation of the structure of the vortical flowfield over delta wings at high angles of attack in longitudinal and with small sideslip angle is presented.Three-dimensional Navier-Stokes numerical simulations were carried out to predict the complex leeward-side flowfield characteristics that are dominated by the effect of the breakdown of the leading-edge vortices. The methods that analyze the flowfield structure quantitatively were given by using flowfield data from the computational results. In the region before the vortex breakdown, the vortex axes are approximated as being straight line. As the angle of attack increases, the vortex axes are closer to the root chord, and farther away from the wing surface. Along the vortex axes, as the adverse pressure gradients occur, the axial velocity decreases, that is, λ is negative, so the vortex is unstable, and it is possible to breakdown. The occurrence of the breakdown results in the instability of lateral motion for a delta wing, and the lateral moment diverges after a small perturbation occurs at high angles of attack. However,after a critical angle of attack is reached, the vortices breakdown completely at the wing apex, and the instability resulting from the vortex breakdown disappears.

  8. Investigation on high angle of attack characteristics of hypersonic space vehicle

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei; LI ShiBin; LIU Jun; WANG ZhenGuo

    2012-01-01

    The high angle of attack characteristics play an important role in the aerodynamic performances of the hypersonic space vehicle.The three-dimensional Reynolds Averaged Navier-Stokes (RANS) equations and the two-equation RNG k-ε turbulence model have been employed to investigate the influence of the high angle of attack on the lift-to-drag ratio and the flow field characteristics of the hypersonic space vehicle,and the contributions of each component to the aerodynamic forces of the vehicle have been discussed as well.At the same time,in order to validate the numerical method,the predicted results have been compared with the available experimental data of a hypersonic slender vehicle,and the grid independency has been analyzed.The obtained results show that the predicted lift-to-drag ratio and pitching moment coefficient show very good agreement with the experimental data in the open literature,and the grid system makes only a slight difference to the numerical results.There exists an optimal angle of attack for the aerodynamic performance of the hypersonic space vehicle,and its value is 20°.When the angle of attack is 20°,the high pressure does not leak from around the leading edge to the upper surface.With the further increasing of the angle of attack,the high pressure spreads from the wing tips to the central area of the vehicle,and overflows from the leading edge again.Further,the head plays an important role in the drag performance of the vehicle,and the lift percentage of the flaperon is larger than that of the rudderevator.This illustrates that the optimization of the flaperon configuration is a great work for the improvement of the aerodynamic performance of the hypersonic space vehicle,especially for a high lift-to-drag ratio.

  9. Study on flow behavior and structure over chined fuselage at high angle of attack

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A study of leeward vortex structure over chined fuselage and the effects of micro tip perturbation on its vortex flow have been carried out in wind tunnel experiments at Reynolds numbers from 1.26×105 to 5.04×105 with PIV and pressure measurement techniques.Firstly,the experiment results have proved that micro tip perturbation has no effects on the vortex flow and its aerodynamic characteristics over chined fuselage at high angle of attack,in which there are not any non-deterministic flow behaviors.Secondly,the evolution of leeward vortex structure over chined fuselage along the axis of model can be divided into four flow regimes:linear conical developed regime,decay regime of leeward vortex intensity,asymmetric leeward vortex break down regime and completely break down regime.And a correlation between leeward vortex structure and sectional aerodynamic force was also revealed in the present paper.Thirdly,the experiment results show the behavior of leeward vortex core trajectories and zonal characteristics of leeward vortex structure with angles of attack.Finally,the experiment results of Reynolds number effect on the leeward vortex flow have further confirmed research conclusions from previous studies:the flows over chined fuselage at high angles of attack are insensitive to variation of Reynolds number,and there is a little effect on the secondary boundary layer separation and the suction peak induced by leeward vortex.

  10. Quasi-periodic dynamics of a high angle of attack aircraft

    Science.gov (United States)

    Rohith, G.; Sinha, Nandan K.

    2017-01-01

    High angle of attack maneuvers closer to stall is a commonly accessed flight regime especially in case of fighter aircrafts. Stall and post-stall dynamics are dominated by nonlinearities which make the analysis difficult. Presence of external factors such as wind makes the system even more complex. Rich nonlinearities point to the possibility of existence of chaotic solutions. Past studies in this area confirm the development of such solutions. These studies are mainly concentrated on very high angle of attack regimes, which may not be practically easily accessible. This paper examines the possibility of existence of chaotic solutions in the lower, more accessible areas in the post stall domain. The analysis is composed of the study of effect of external wind as an agent to drive the system towards the possibility of a chaotic solution. Investigations reveal presence of quasi-periodic solutions, which are characterized by two incommensurate frequencies. This solution appears in the time simulation by varying the control parameter viz., wind. The solutions correspond to the values in the lower region of the angle of attack versus elevator bifurcation curve in the post-stall region. A steady wind is considered for the analysis and explores the possibility of chaotic motion by increasing the wind in a step wise manner. It is found that wind adds extra energy to the system which in turn drives the system in to chaos. The analysis is done with the help of phase portrait, Poincare map and amplitude spectrum and a quasi-periodic route to chaos via torus doubling is also presented.

  11. Prediction of forces and moments on finned bodies at high angle of attack in transonic flow

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, W. L.

    1981-04-01

    This report describes a theoretical method for the prediction of fin forces and moments on bodies at high angle of attack in subsonic and transonic flow. The body is assumed to be a circular cylinder with cruciform fins (or wings) of arbitrary planform. The body can have an arbitrary roll (or bank) angle, and each fin can have individual control deflection. The method combines a body vortex flow model and lifting surface theory to predict the normal force distribution over each fin surface. Extensive comparisons are made between theory and experiment for various planform fins. A description of the use of the computer program that implements the method is given.

  12. Flight validation of ground-based assessment for control power requirements at high angles of attack

    Science.gov (United States)

    Ogburn, Marilyn E.; Ross, Holly M.; Foster, John V.; Pahle, Joseph W.; Sternberg, Charles A.; Traven, Ricardo; Lackey, James B.; Abbott, Troy D.

    1994-01-01

    A review is presented in viewgraph format of an ongoing NASA/U.S. Navy study to determine control power requirements at high angles of attack for the next generation high-performance aircraft. This paper focuses on recent flight test activities using the NASA High Alpha Research Vehicle (HARV), which are intended to validate results of previous ground-based simulation studies. The purpose of this study is discussed, and the overall program structure, approach, and objectives are described. Results from two areas of investigation are presented: (1) nose-down control power requirements and (2) lateral-directional control power requirements. Selected results which illustrate issues and challenges that are being addressed in the study are discussed including test methodology, comparisons between simulation and flight, and general lessons learned.

  13. 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.

  14. ASYMMETRIC VORTICES FLOW OVER SLENDER BODY AND ITS ACTIVE CONTROL AT HIGH ANGLE OF ATTACK

    Institute of Scientific and Technical Information of China (English)

    DENG Xueying; WANG Yankui

    2004-01-01

    The studies of asymmetric vortices flow over slender body and its active control at high angles of attack have significant importance for both academic field and engineering area. This paper attempts to provide an update state of art to the investigations on the fields of forebody asymmetric vortices. This review emphasizes the correlation between micro-perturbation on the model nose and its response and evolution behaviors of the asymmetric vortices. The critical issues are discussed,which include the formation and evolution mechanism of asymmetric multi-vortices; main behaviors of asymmetric vortices flow including its deterministic feature and vortices flow structure; the evolution and development of asymmetric vortices under the perturbation on the model nose; forebody vortex active control especially discussed micro-perturbation active control concept and technique in more detail. However present understanding in this area is still very limited and this paper tries to identify the key unknown problems in the concluding remarks.

  15. Delayed detached eddy simulations of fighter aircraft at high angle of attack

    Institute of Scientific and Technical Information of China (English)

    Guoliang Xu; Xiong Jiang; Gang Liu

    2016-01-01

    The massively separated flows over a realistic air-craft configuration at 40◦, 50◦, and 60◦angles of attack are studied using the delayed detached eddy simulation (DDES). The calculations are carried out at experimental conditions corresponding to a mean aerodynamic chord-based Reynolds number of 8.93 × 105 and Mach number of 0.088. The influ-ence of the grid size is investigated using two grids, 20.0×106 cells and 31.0 × 106 cells. At the selected conditions, the lift, drag, and pitching moment from DDES predictions agree with the experimental data better than that from the Reynolds-averaged Navier–Stokes. The effect of angle of attack on the flow structure over the general aircraft is also studied, and it is found that the dominated frequency associated with the vortex shedding process decreases with increasing angle of attack.

  16. Dynamic surface measurements on a model helicopter rotor during blade slap at high angles of attack

    Science.gov (United States)

    Hubbard, J. E., Jr.; Harris, W. L.

    1982-01-01

    The modern helicopter offers a unique operational capability to both the public and private sectors. However, the use of the helicopter may become severely limited due to the radiated noise generated by the rotor system. A description is presented of some of the experimental results obtained with a model helicopter rotor in an anechoic wind tunnel with regard to blade stall as a source mechanism of blade slap. Attention is given to dynamic rotor blade surface phenomena and the resulting far field impulsive noise from the model helicopter rotor at high angles of attack and low tip speed. The results of the investigation strongly implicates the boundary layer as playing an important role in blade slap due to blade/vortex interaction (BVI) in a highly loaded rotor. Intermittent stall cannot be ruled out as a possible source mechanism for blade slap. This implies that blade surface characteristics, airfoil shape and local Reynolds number may now be used as tools to reduce the resultant far-field sound pressure levels in helicopters.

  17. 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.

  18. High angle of attack: Forebody flow physics and design emphasizing directional stability

    Science.gov (United States)

    Ravi, R.

    A framework for understanding the fundamental physics of flowfields over forebody type shapes at low speed, high angle of attack conditions with special emphasis on sideslip has been established. Computational Fluid Dynamics (CFD) has been used to study flowfieids over experimentally investigated forebodies: the Lamont tangent-ogive forebody, the F-5A forebody and the Erickson chine forebody. A modified version of a current advanced code, CFL3D, was used to solve the Euler and thin-layer Navier-Stokes equations. The Navier-Stokes equations used a form of the Baldwin-Lomax turbulence model modified to account for massive crossflow separation. Using the insight provided by the solutions obtained using CFD, together with comparison with limited available data, the aerodynamics of forebodies with positive directional stability has been revealed. An unconventional way of presenting the results is used to illustrate how a positive contribution to directional stability arises. Based on this new understanding, a parametric study was then conducted to determine which shapes promote a positive contribution to directional stability. The effect of cross-sectional shape on directional stability was found to be very significant. Broad chine-shaped cross-sections were found to promote directional stability. Also, directional stability is improved if the chine is placed closer to the top of the cross-section. Planform shapes also played an important role in determining the forebody directional stability characteristics. This initial parametric study has been used to propose some guidelines for aerodynamic design to promote positive directional stability.

  19. An experimental study of an airfoil with a bio-inspired leading edge device at high angles of attack

    Science.gov (United States)

    Mandadzhiev, Boris A.; Lynch, Michael K.; Chamorro, Leonardo P.; Wissa, Aimy A.

    2017-09-01

    Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. Deployable aerodynamic surfaces from the wing leading or trailing edges are often used to extend the aerodynamic envelope (e.g. slats and flaps). Birds have also evolved feathers at the leading edge (LE) of their wings, known as the alula, which enables them to perform high angles of attack maneuvers. In this study, a series of wind tunnel experiments are performed to quantify the effect of various deployment parameters of an alula-like LE device on the aerodynamic performance of a cambered airfoil (S1223) at stall and post stall conditions. The alula relative angle of attack, measured from the mean chord of the airfoil, is varied to modulate tip-vortex strength, while the alula deflection angle is varied to modulate the distance between the tip vortex and the wing surface. Integrated lift force measurements were collected at various alula-inspired device configurations. The effect of the alula-inspired device on the boundary layer velocity profile and turbulence intensity were investigated through hot-wire anemometer measurements. Results show that as alula deflection angle increases, the lift coefficient also increase especially at lower alula relative angles of attack. Moreover, at post stall wing angles of attack, the wake velocity deficit is reduced in the presence of alula device, confirming the mitigation of the wing adverse pressure gradient. The results are in strong agreement with measurements taken on bird wings showing delayed flow reversal and extended range of operational angles of attack. An engineered alula-inspired device has the potential to improve mission adaptability in small unmanned air vehicles during low Reynolds number flight.

  20. X-29 High Angle-of-Attack Flying Qualities

    Science.gov (United States)

    1991-06-01

    flhit and closure rate. Limited military utility tesIs ith thw variable gain capability. Predicted large amplitude increased roll-rate .apability...33 ll! )3l 17, oq jimod [013110 qildmoitmii~pojiro paso 1/OS0 0Jo ( ptio3O5; jad saai1 £ LI 0 Zpuo00S iod sMp 0)qlU)141)1A1 43iq pajli uaaq 0A111 p

  1. Parametric approximation of airfoil aerodynamic coefficients at high angles of attack

    DEFF Research Database (Denmark)

    Skrzypinski, Witold Robert; Zahle, Frederik; Bak, Christian

    2014-01-01

    , and the third method, also utilizing trigonometric functions, was developed with the scope on stall-regulated turbines. The method of the even sine and cosine functions was further developed in the present work by using two independent harmonic approximations in the positive and negative α regions......Three methods for estimating the lift and drag curves in the 360° angle of attack (α) range with harmonic approximation functions were analyzed in the present work. The first method assumes aerodynamic response of a flat plate, the second utilizes even sine and even cosine approximation functions...

  2. Simulator study of the effectiveness of an automatic control system designed to improve the high-angle-of-attack characteristics of a fighter airplane

    Science.gov (United States)

    Gilbert, W. P.; Nguyen, L. T.; Vangunst, R. W.

    1976-01-01

    A piloted, fixed-base simulation was conducted to study the effectiveness of some automatic control system features designed to improve the stability and control characteristics of fighter airplanes at high angles of attack. These features include an angle-of-attack limiter, a normal-acceleration limiter, an aileron-rudder interconnect, and a stability-axis yaw damper. The study was based on a current lightweight fighter prototype. The aerodynamic data used in the simulation were measured on a 0.15-scale model at low Reynolds number and low subsonic Mach number. The simulation was conducted on the Langley differential maneuvering simulator, and the evaluation involved representative combat maneuvering. Results of the investigation show the fully augmented airplane to be quite stable and maneuverable throughout the operational angle-of-attack range. The angle-of-attack/normal-acceleration limiting feature of the pitch control system is found to be a necessity to avoid angle-of-attack excursions at high angles of attack. The aileron-rudder interconnect system is shown to be very effective in making the airplane departure resistant while the stability-axis yaw damper provided improved high-angle-of-attack roll performance with a minimum of sideslip excursions.

  3. Low-frequency unsteadiness of vortex wakes over slender bodies at high angle of attack

    Directory of Open Access Journals (Sweden)

    Ma Baofeng

    2014-08-01

    Full Text Available A type of flow unsteadiness with low frequencies and large amplitude was investigated experimentally for vortex wakes around an ogive-tangent cylinder. The experiments were carried out at angles of attack of 60–80° and subcritical Reynolds numbers of 0.6–1.8 × 105. The reduced frequencies of the unsteadiness are between 0.038 and 0.072, much less than the frequency of Karman vortex shedding. The unsteady flow induces large fluctuations of sectional side forces. The results of pressure measurements and particle image velocimetry indicate that the flow unsteadiness comes from periodic oscillation of the vortex wakes over the slender body. The time-averaged vortex patterns over the slender body are asymmetric, whose orientation is dependent on azimuthal locations of tip perturbations. Therefore, the vortex oscillation is a type of unsteady oscillation around a time-averaged asymmetric vortex structure.

  4. Development of microprocessor-based laser velocimeter and its application to measurement of jet exhausts and flows over missiles at high angles of attack

    Science.gov (United States)

    Harwell, K. E.; Farmer, W. M.; Hornkohl, J. O.; Stallings, E.

    1981-03-01

    During the past three years, personnel have developed a unique three-component laser velocimeter for the in situ measurement of particle and/or gas velocities in flow fields produced behind bodies at high angles of attack and in jet exhaust plumes. This report describes the development of the laser velocimeter and its subsequent application of the measurement of the velocity distribution and vortex structure in free jets and in flows over missiles at high angles of attack.

  5. Navy and the HARV: High angle of attack tactical utility issues

    Science.gov (United States)

    Sternberg, Charles A.; Traven, Ricardo; Lackey, James B.

    1994-01-01

    This presentation will highlight results from the latest Navy evaluation of the HARV (March 1994) and focus primarily on the impressions from a piloting standpoint of the tactical utility of thrust vectoring. Issue to be addressed will be mission suitability of high AOA flight, visual and motion feedback cues associated with operating at high AOA, and the adaptability of a pilot to effectively use the increased control power provided by the thrust vectoring system.

  6. Lattice Boltzmann Method used for the aircraft characteristics computation at high angle of attack

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Traditional Finite Volume Method(FVM)and Lattice Boltzmann Method(LBM)are both used to compute the high angle attack aerodynamic characteristics of the benchmark aircraft model named CT-1.Even though the software requires flow on the order of Ma<0.4,simulation at Ma=0.5 is run in PowerFLOW after theoretical analysis.The consistency with the wind tunnel testing is satisfied,especially for the LBM which can produce perfect results at high angle attack.PowerFLOW can accurately capture the detail of flows because it is inherently time-dependent and parallel and suits large-scale computation very well.

  7. 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.

  8. Ionospheric plasma flow over large high-voltage space platforms. I - Ion-plasma-time scale interactions of a plate at zero angle of attack. II - The formation and structure of plasma wake

    Science.gov (United States)

    Wang, J.; Hastings, D. E.

    1992-01-01

    The paper presents the theory and particle simulation results for the ionospheric plasma flow over a large high-voltage space platform at a zero angle of attack and at a large angle of attack. Emphasis is placed on the structures in the large, high-voltage regime and the transient plasma response on the ion-plasma time scale. Special consideration is given to the transient formation of the space-charge wake and its steady-state structure.

  9. BiGlobal linear stability analysis on low-Re flow past an airfoil at high angle of attack

    KAUST Repository

    Zhang, Wei

    2016-04-04

    We perform BiGlobal linear stability analysis on flow past a NACA0012 airfoil at 16° angle of attack and Reynolds number ranging from 400 to 1000. The steady-state two-dimensional base flows are computed using a well-tested finite difference code in combination with the selective frequency damping method. The base flow is characterized by two asymmetric recirculation bubbles downstream of the airfoil whose streamwise extent and the maximum reverse flow velocity increase with the Reynolds number. The stability analysis of the flow past the airfoil is carried out under very small spanwise wavenumber β = 10−4 to approximate the two-dimensional perturbation, and medium and large spanwise wavenumbers (β = 1–8) to account for the three-dimensional perturbation. Numerical results reveal that under small spanwise wavenumber, there are at most two oscillatory unstable modes corresponding to the near wake and far wake instabilities; the growth rate and frequency of the perturbation agree well with the two-dimensional direct numerical simulation results under all Reynolds numbers. For a larger spanwise wavenumber β = 1, there is only one oscillatory unstable mode associated with the wake instability at Re = 400 and 600, while at Re = 800 and 1000 there are two oscillatory unstable modes for the near wake and far wake instabilities, and one stationary unstable mode for the monotonically growing perturbation within the recirculation bubble via the centrifugal instability mechanism. All the unstable modes are weakened or even suppressed as the spanwise wavenumber further increases, among which the stationary mode persists until β = 4.

  10. Flight and wind-tunnel calibrations of a flush airdata sensor at high angles of attack and sideslip and at supersonic Mach numbers

    Science.gov (United States)

    Moes, Timothy R.; Whitmore, Stephen A.; Jordan, Frank L., Jr.

    1993-01-01

    A nonintrusive airdata-sensing system was calibrated in flight and wind-tunnel experiments to an angle of attack of 70 deg and to angles of sideslip of +/- 15 deg. Flight-calibration data have also been obtained to Mach 1.2. The sensor, known as the flush airdata sensor, was installed on the nosecap of an F-18 aircraft for flight tests and on a full-scale F-18 forebody for wind-tunnel tests. Flight tests occurred at the NASA Dryden Flight Research Facility, Edwards, California, using the F-18 High Alpha Research Vehicle. Wind-tunnel tests were conducted in the 30- by 60-ft wind tunnel at the NASA LaRC, Hampton, Virginia. The sensor consisted of 23 flush-mounted pressure ports arranged in concentric circles and located within 1.75 in. of the tip of the nosecap. An overdetermined mathematical model was used to relate the pressure measurements to the local airdata quantities. The mathematical model was based on potential flow over a sphere and was empirically adjusted based on flight and wind-tunnel data. For quasi-steady maneuvering, the mathematical model worked well throughout the subsonic, transonic, and low supersonic flight regimes. The model also worked well throughout the angles-of-attack and -sideslip regions studied.

  11. A source term model of perturbation in a numerical study on flows around a slender body of revolution at a high angle of attack

    Institute of Scientific and Technical Information of China (English)

    Yang Liu; Dongjun Ma; Dejun Sun; Xieyuan Yin

    2009-01-01

    A numerical study on flows around a slender body of revolution at a high angle of attack is conducted to investigate the influence of strength and circumferential angle of perturbation on flow asymmetry.A source term model is applied to simulate a real geometrical perturbation near the tip of the slender body.It can greatly facilitate the adjustment of perturbation strength.The results show that the bistable phenomenon does not appear any more at a small perturbation strength.For different perturbation strengths,the energy of the asymmetric perturbation flow experiences a similar spatial exponential growth regime with the same growth rate.The appearance of the bistable phenomenon is closely related to nonlinear saturation of the perturbation flow as perturbation strength increases.

  12. An experimental investigation of thrust vectoring two-dimensional convergent-divergent nozzles installed in a twin-engine fighter model at high angles of attack

    Science.gov (United States)

    Capone, Francis J.; Mason, Mary L.; Leavitt, Laurence D.

    1990-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine thrust vectoring capability of subscale 2-D convergent-divergent exhaust nozzles installed on a twin engine general research fighter model. Pitch thrust vectoring was accomplished by downward rotation of nozzle upper and lower flaps. The effects of nozzle sidewall cutback were studied for both unvectored and pitch vectored nozzles. A single cutback sidewall was employed for yaw thrust vectoring. This investigation was conducted at Mach numbers ranging from 0 to 1.20 and at angles of attack from -2 to 35 deg. High pressure air was used to simulate jet exhaust and provide values of nozzle pressure ratio up to 9.

  13. Fundamentals and Methods of High Angle-of-Attack Flying Qualities Research

    Science.gov (United States)

    1988-01-01

    Solving Equation (6) for the spin Radius, R, and substituting into equation (13), ay can be redefined in terms of fib 𔃼V as given by equation (17). (T...14) through (16) respectively) are functions of flb/2V, o, and a. Thus there are three equations to solve for three unknowns ( fib /2V, 1, a) in order...January 17,1983, pp. 57-62. 86. Markman, Steven R., "Capabilities of Airborne and Ground Based Flight Simulation," AIAA Paper 85-1944. 87. Knotts

  14. AEROX: Computer program for transonic aircraft aerodynamics to high angles of attack. Volume 1: Aerodynamic methods and program users' guide

    Science.gov (United States)

    Axelson, J. A.

    1977-01-01

    The AEROX program estimates lift, induced-drag and pitching moments to high angles (typ. 60 deg) for wings and for wingbody combinations with or without an aft horizontal tail. Minimum drag coefficients are not estimated, but may be input for inclusion in the total aerodynamic parameters which are output in listed and plotted formats. The theory, users' guide, test cases, and program listing are presented.

  15. High Angle of Attack Aerodynamics

    Science.gov (United States)

    1979-01-01

    autour du bond d’attaque au voisinage du fuselage rosto attachd, le bord d’attaquo 6tant At Ia fois arrondi ot cambr6. En quittant le fuselage le rayon ...ont Wt obtenus par d~u~l~ration on pallor aux diff~rents contrages . Pour offectuer une comparaison avec Ia soufflerle i1 oat n~cessaire do corriger les...Lo Longueur de l’ogive CL to de moment de roulis r Rayon de 1’Omoussement Cm de moment de tangage S Surface de r~f~rence :maltre - couple Cn de

  16. Analysis of the longitudinal handling qualities and pilot-induced-oscillation tendencies of the High-Angle-of-Attack Research Vehicle (HARV)

    Science.gov (United States)

    Hess, Ronald A.

    1994-01-01

    The NASA High-Angle-of Attack Research Vehicle (HARV), a modified F-18 aircraft, experienced handling qualities problems in recent flight tests at NASA Dryden Research Center. Foremost in these problems was the tendency of the pilot-aircraft system to exhibit a potentially dangerous phenomenon known as a pilot-induced oscillation (PIO). When they occur, PIO's can severely restrict performance, sharply dimish mission capabilities, and can even result in aircraft loss. A pilot/vehicle analysis was undertaken with the goal of reducing these PIO tendencies and improving the overall vehicle handling qualities with as few changes as possible to the existing feedback/feedforward flight control laws. Utilizing a pair of analytical pilot models developed by the author, a pilot/vehicle analysis of the existing longitudinal flight control system was undertaken. The analysis included prediction of overall handling qualities levels and PIO susceptability. The analysis indicated that improvement in the flight control system was warranted and led to the formulation of a simple control stick command shaping filter. Analysis of the pilot/vehicle system with the shaping filter indicated significant improvements in handling qualities and PIO tendencies could be achieved. A non-real time simulation of the modified control system was undertaken with a realistic, nonlinear model of the current HARV. Special emphasis was placed upon those details of the command filter implementation which could effect safety of flight. The modified system is currently awaiting evaluation in the real-time, pilot-in-the-loop, Dual-Maneuvering-Simulator (DMS) facility at Langley.

  17. High Angle-of-Attack Aerodynamics

    Science.gov (United States)

    1982-12-01

    of oil-streak lines toward a particular line. Whether this is also a sufficient con- dition is a matter of current debate. Of the many attempts to...ON THE SAAB-VIGGEN CANARD-WING AIRCRAFT AT 30-DEGREE AGA INORTHROP WATER TUNNEL) I ins viiribls flowus interactin al-5 occrs’r’ betwieens 41 ligslY...lead, with the missile mass in mind , to structures with minimal structural stiffness. Consequently, effects of aeroelasticity may play a role. Due to

  18. A hybrid system approach to airspeed, angle of attack and sideslip estimation in Unmanned Aerial Vehicles

    KAUST Repository

    Shaqura, Mohammad

    2015-06-01

    Fixed wing Unmanned Aerial Vehicles (UAVs) are an increasingly common sensing platform, owing to their key advantages: speed, endurance and ability to explore remote areas. While these platforms are highly efficient, they cannot easily be equipped with air data sensors commonly found on their larger scale manned counterparts. Indeed, such sensors are bulky, expensive and severely reduce the payload capability of the UAVs. In consequence, UAV controllers (humans or autopilots) have little information on the actual mode of operation of the wing (normal, stalled, spin) which can cause catastrophic losses of control when flying in turbulent weather conditions. In this article, we propose a real-time air parameter estimation scheme that can run on commercial, low power autopilots in real-time. The computational method is based on a hybrid decomposition of the modes of operation of the UAV. A Bayesian approach is considered for estimation, in which the estimated airspeed, angle of attack and sideslip are described statistically. An implementation on a UAV is presented, and the performance and computational efficiency of this method are validated using hardware in the loop (HIL) simulation and experimental flight data and compared with classical Extended Kalman Filter estimation. Our benchmark tests shows that this method is faster than EKF by up to two orders of magnitude. © 2015 IEEE.

  19. Effect of Mean Angle of Attack Modulation on Dynamic Stall

    Science.gov (United States)

    Heintz, Kyle; Corke, Thomas

    2016-11-01

    Wind tunnel experiments at M = 0 . 2 were conducted on a cambered airfoil instrumented with surface pressure transducers that was oscillated with two independent frequencies. The primary input, f1, corresponds to a range of reduced frequencies, while the slower, secondary input, f2, drives the modulation of the mean angle of attack, thus varying the stall-penetration angle, αpen. Various combinations transitioned different regimes of dynamic stall from "light" to "deep". Results suggest that when αpen is falling between consecutive cycles, the aerodynamic loads do not fully recover to the values seen when αpen is rising, even though the airfoil recedes to αpen load coefficients, aerodynamic damping, and their phase relationships to pitch angle. APS Fellow.

  20. Review of Research On Angle-of-Attack Indicator Effectiveness

    Science.gov (United States)

    Le Vie, Lisa R.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) conducted a literature review to determine the potential benefits of a display of angle-of-attack (AoA) on the flight deck of commercial transport that may aid a pilot in energy state awareness, upset recovery, and/or diagnosis of air data system failure. This literature review encompassed an exhaustive list of references available and includes studies on the benefits of displaying AoA information during all phases of flight. It also contains information and descriptions about various AoA indicators such as dial, vertical and horizontal types as well as AoA displays on the primary flight display and the head up display. Any training given on the use of an AoA indicator during the research studies or experiments is also included for review

  1. Determination of the angle of attack on rotor blades

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Hansen, Martin Otto Laver; Sørensen, Jens Nørkær

    2009-01-01

    Two simple methods for determining the angle of attack (AOA) on a section of a rotor blade are proposed. Both techniques consist of employing the Biot-Savart integral to determine the influence of the bound vorticity on the velocity field. In the first technique, the force distribution along...... the blade and the velocity at a monitor point in the vicinity of the blade are assumed to be known from experiments or CFD computations. The AOA is determined by subtracting the velocity induced by the bound circulation, determined from the loading, from the velocity at the monitor point. In the second...... to be located closer to the blade, and thus to determine the AOA with higher accuracy. Data from CFD computations for flows past the Tellus 95 kW wind turbine at different wind speeds are used to test both techniques. Comparisons show that the proposed methods are in good agreement with existing techniques...

  2. Effects of Sudden Changes in Inflow Conditions on the Angle of Attack on HAWT Blades

    CERN Document Server

    Stoevesandt, Bernhard

    2010-01-01

    In this paper changes in wind speed and wind direction from a measured wind field are being analyzed at high frequencies. This is used to estimate changes in the angle of attack (AOA) on a blade segment over short time periods for different estimated turbine concepts. Here a statistical approach is chosen to grasp the characteristics of the probability distributions to give an over all view of the magnitude and rate of the changes. The main interest is the generation of basic distributions for the calculation of dynamic stall effects and stall flutter due to wind fluctuations.

  3. Wind Tunnel Corrections for High Angle of Attack Models,

    Science.gov (United States)

    1981-02-01

    2) . De telles confrontations sont bien entendu specifiquss des maquettes utilises et en particulier devraient Stre developp^es dans le domaine des...d’essais, il y a lieu de tenir compte des qualitds de l’ecoulement aussi bien stationnaire (ascendance, gradient longitudinal de pression) qu’in...luence des divers parametres ne peut etre etudiee isolement car il n’est pas encore possiblt re les faire varier. L’ONERA a dejä public des travaux

  4. Wind-tunnel calibration and requirements for in-flight use of fixed hemispherical head angle-of-attack and angle-of-sideslip sensors

    Science.gov (United States)

    Montoya, E. J.

    1973-01-01

    Wind-tunnel tests were conducted with three different fixed pressure-measuring hemispherical head sensor configurations which were strut-mounted on a nose boom. The tests were performed at free-stream Mach numbers from 0.2 to 3.6. The boom-angle-of-attack range was -6 to 15 deg, and the angle-of-sideslip range was -6 to 6 deg. The test Reynolds numbers were from 3.28 million to 65.6 million per meter. The results were used to obtain angle-of-attack and angle-of-sideslip calibration curves for the configurations. Signal outputs from the hemispherical head sensor had to be specially processed to obtain accurate real-time angle-of-attack and angle-of-sideslip measurements for pilot displays or aircraft systems. Use of the fixed sensors in flight showed them to be rugged and reliable and suitable for use in a high temperature environment.

  5. Flow around a slotted circular cylinder at various angles of attack

    Science.gov (United States)

    Gao, Dong-Lai; Chen, Wen-Li; Li, Hui; Hu, Hui

    2017-10-01

    We experimentally investigated the flow characteristics around a circular cylinder with a slot at different angles of attack. The experimental campaign was performed in a wind tunnel at the Reynolds number of Re = 2.67 × 104. The cylindrical test model was manufactured with a slot at the slot width S = 0.075 D ( D is the diameter of the cylinder). The angle of attack α was varied from 0° to 90°. In addition to measuring the pressure distributions around the cylinder surface, a digital particle image velocimetry (PIV) system was employed to quantify the wake flow characteristics behind the baseline cylinder (i.e., baseline case of the cylinder without slot) and slotted cylinder at various angles of attack. Measurement results suggested that at low angles of attack, the passive jet flow generated by the slot would work as an effective control scheme to modify the wake flow characteristics and contribute to reducing the drag and suppressing the fluctuating lift. The flip-flop phenomenon was also identified and discussed with the slot at 0° angle of attack. As the angle of attack α became 45°, the effects of the slot were found to be minimal. When the angle of attack α of the slot approached 90°, the self-organized boundary layer suction and blowing were realized. As a result, the flow separations on both sides of the test model were found to be notably delayed, the wake width behind the slotted cylinder was decreased and the vortex formation length was greatly shrunk, in comparison with the baseline case. Instantaneous pressure measurement results revealed that the pressure difference between the two slot ends and the periodically fluctuating pressure distributions would cause the alternative boundary layer suction and blowing at α = 90°.

  6. Development of a method of analysis and computer program for calculating the inviscid flow about the windward surfaces of space shuttle configurations at large angles of attack

    Science.gov (United States)

    Maslen, S. H.

    1974-01-01

    A general method developed for the analysis of inviscid hypersonic shock layers is discussed for application to the case of the shuttle vehicle at high (65 deg) angle of attack. The associated extensive subsonic flow region caused convergence difficulties whose resolution is discussed. It is required that the solution be smoother than anticipated.

  7. In-blade angle of attack measurement and comparison with models

    Science.gov (United States)

    Gallant, T. E.; Johnson, D. A.

    2016-09-01

    The torque generated by a wind turbine blade is dependent on several parameters, one of which is the angle of attack. Several models for predicting the angle of attack in yawed conditions have been proposed in the literature, but there is a lack of experimental data to use for direct validation. To address this problem, experiments were conducted at the University of Waterloo Wind Generation Research Facility using a 3.4 m diameter test turbine. A five-hole pressure probe was installed in a modular 3D printed blade and was used to measure the angle of attack, a, as a function of several parameters. Measurements were conducted at radial positions of r/R = 0.55 and 0.72 at tip speed ratios of λ = 5.0, 3.6, and 3.1. The yaw offset of the turbine was varied from -15° to +15°. Experimental results were compared directly to angle of attack values calculated using a model proposed by Morote in 2015. Modeled values were found to be in close agreement with the experimental results. The angle of attack was shown to vary cyclically in the yawed case while remaining mostly constant when aligned with the flow, as expected. The quality of results indicates the potential of the developed instrument for wind turbine measurements.

  8. Influence of Thickness and Angle of Attack on the Dynamics of Rectangular Cylinder Wakes

    Science.gov (United States)

    Mohebi, Meraj

    Stereoscopic Particle Image Velocimetry measurements were taken in the turbulent wake of two-dimensional rectangular cylinders. The influence of post-stall angles of attack and Reynolds number on the flow behind a thin at plate, and for the normal case, the effect of thickness to chord (t=d) ratio over a family of rectangular cylinders were investigated. At all cases, quasi-periodic vortex shedding is observed, the normal direction Reynolds stress becomes very large just downstream of the mean recirculation zone, and the spanwise motions were uncorrelated to the main vortex shedding process. The data were processed to obtain the mean velocities, Reynolds stresses, and forces on the body. All terms in the turbulent kinetic energy equations were measured with the exception of dissipation which was found by difference. The pressure-related terms were estimated from the numerical solution of the Poisson equation for the instantaneous velocity field. Proper Orthogonal Decomposition modes are related via mean-field theory to construct generalized phase-averaging and low-order models capturing coherent cycle-to-cycle variations. The advection, production and pressure diffusion were all significant and mostly coherent. It is shown that high, average, and low amplitude vortex shedding cycles are different in terms of vortex street dimensions, vortex topology, circulation, and decay rate. It is also shown that these flows experience irregular significant decreases in the shedding amplitude associated with shedding of disorganized vortices in a large wake. Reynolds number was found to have imperceptible effects on the wake of a normal thin plate. A reduction in the angle of attack caused the wake to decrease in size and increase in shedding frequency but the global characteristics vary non-linearly. An increase in thickness from thin plate (t=d=0.05), caused the wake to shrink, low cycles to diminish, and local turbulence increase to a peak at t=d=1.0, identified as a

  9. Effects of Angle of Attack and Velocity on Trailing Edge Noise

    Science.gov (United States)

    Hutcheson, Florence V.; Brooks, Thomas F.

    2006-01-01

    Trailing edge (TE) noise measurements for a NACA 63-215 airfoil model are presented, providing benchmark experimental data for a cambered airfoil. The effects of flow Mach number and angle of attack of the airfoil model with different TE bluntnesses are shown. Far-field noise spectra and directivity are obtained using a directional microphone array. Standard and diagonal removal beamforming techniques are evaluated employing tailored weighting functions for quantitatively accounting for the distributed line character of TE noise. Diagonal removal processing is used for the primary database as it successfully removes noise contaminates. Some TE noise predictions are reported to help interpret the data, with respect to flow speed, angle of attack, and TE bluntness on spectral shape and peak levels. Important findings include the validation of a TE noise directivity function for different airfoil angles of attack and the demonstration of the importance of the directivity function s convective amplification terms.

  10. Measurement of Aerodynamic Forces for Various Mean Angles of Attack on an Airfoil Oscillating in Pitch and on Two Finite-span Wings Oscillating in Bending with Emphasis on Damping in the Stall

    Science.gov (United States)

    Rainey, A Gerald

    1957-01-01

    The oscillating air forces on a two-dimensional wing oscillating in pitch about the midchord have been measured at various mean angles of attack and at Mach numbers of 0.35 and 0.7. The magnitudes of normal-force and pitching-moment coefficients were much higher at high angles of attack than at low angles of attack for some conditions. Large regions of negative damping in pitch were found, and it was shown that the effect of increasing the Mach number 0.35 to 0.7 was to decrease the initial angle of attack at which negative damping occurred. Measurements of the aerodynamic damping of a 10-percent-thick and of a 3-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack. (author)

  11. Wind-tunnel investigation of the flow correction for a model-mounted angle of attack sensor at angles of attack from -10 deg to 110 deg. [Langley 12-foot low speed wind tunnel test

    Science.gov (United States)

    Moul, T. M.

    1979-01-01

    A preliminary wind tunnel investigation was undertaken to determine the flow correction for a vane angle of attack sensor over an angle of attack range from -10 deg to 110 deg. The sensor was mounted ahead of the wing on a 1/5 scale model of a general aviation airplane. It was shown that the flow correction was substantial, reaching about 15 deg at an angle of attack of 90 deg. The flow correction was found to increase as the sensor was moved closer to the wing or closer to the fuselage. The experimentally determined slope of the flow correction versus the measured angle of attack below the stall angle of attack agreed closely with the slope of flight data from a similar full scale airplane.

  12. Doppler radiation sensing of Shuttle angle of attack and TAS during entry

    Science.gov (United States)

    Foale, C. M.

    Space Shuttle true airspeed, angle of attack, and sideslip angle are currently derived from inertial guidance information. A new method is proposed which offers a potential improvement in Shuttle safety during entry. Angle of attack, sideslip angle and true airspeed could be measured directly at heights from 120 km down to 20 km by Doppler sensing three independent true airspeeds along the Shuttle body axes. Two types of Doppler measurement sensors, employing either passive detection of atmospheric radiation or coherent detection of scattered laser light are discussed. The proposed technique is essentially solid-state and robust, and is well suited for use in future small hypersonic vehicles that require flight control in the Upper Atmosphere of the earth or in probes destined for the other planets.

  13. Stability Analysis of Hypersonic Boundary Layer over a Cone at Small Angle of Attack

    Directory of Open Access Journals (Sweden)

    Feng Ji

    2014-04-01

    Full Text Available An investigation on the stability of hypersonic boundary layer over a cone at small angle of attack has been performed. After obtaining the steady base flow, linear stability theory (LST analysis has been made with local parallel assumption. The growth rates of the first mode and second mode waves at different streamwise locations and different azimuthal angles are obtained. The results show that the boundary layer stability was greatly influenced by small angles of attack. The maximum growth rate of the most unstable wave on the leeward is larger than that on the windward. Moreover, dominating second mode wave starts earlier on the leeward than that on the windward. The LST result also shows that there is a “valley” region around 120°~150° meridian in the maximum growth rates curve.

  14. Evaluation of electrolytic tilt sensors for measuring model angle of attack in wind tunnel tests

    Science.gov (United States)

    Wong, Douglas T.

    1992-01-01

    The results of a laboratory evaluation of electrolytic tilt sensors as potential candidates for measuring model attitude or angle of attack in wind tunnel tests are presented. The performance of eight electrolytic tilt sensors was compared with that of typical servo accelerometers used for angle-of-attack measurements. The areas evaluated included linearity, hysteresis, repeatability, temperature characteristics, roll-on-pitch interaction, sensitivity to lead-wire resistance, step response time, and rectification. Among the sensors being evaluated, the Spectron model RG-37 electrolytic tilt sensors have the highest overall accuracy in terms of linearity, hysteresis, repeatability, temperature sensitivity, and roll sensitivity. A comparison of the sensors with the servo accelerometers revealed that the accuracy of the RG-37 sensors was on the average about one order of magnitude worse. Even though a comparison indicates that the cost of each tilt sensor is about one-third the cost of each servo accelerometer, the sensors are considered unsuitable for angle-of-attack measurements. However, the potential exists for other applications such as wind tunnel wall-attitude measurements where the errors resulting from roll interaction, vibration, and response time are less and sensor temperature can be controlled.

  15. DSMC simulation for effects of angles of attack on rarefied hypersonic cavity flows

    Science.gov (United States)

    Jin, Xuhon; Huang, Fei; Shi, Jiatong; Cheng, Xiaoli

    2016-11-01

    The present work investigates rarefied hypersonic flows over a flat plate with two-dimensional and three-dimensional cavities by employing the direct simulation Monte Carlo (DSMC) method, focusing on the effect of angles of attack (AOAs) on flow structure inside the cavity and aerodynamic surface quantities. It was found that only one primary recirculation structure was formed inside the cavity at the angle of attack (AOA) of 0°, while a second vortex system was produced just beneath the primary one with the angle of attack increased to 30°. As AOAs grow, the freestream flow is able to penetrate deeper into the cavity and attach itself to the cavity base, making the "dead-water" region shrink. Meantime, with the increment in the AOA, both heat transfer and pressure coefficients show a similar and gradual quantitative behavior, and along centerlines of the two side surfaces of the cavity, both pressure and heat transfer coefficients become growing, indicating that the increase in the AOA does enhance momentum and energy transfer to both the two aforementioned surfaces. However, the heat flux over the cavity floor does not keep increasing with the growth of the AOA, while the pressure does, indicating that augmenting AOAs does not enhance momentum to the cavity floor, but does make compressibility stronger and stronger near the cavity base.

  16. Hydrodynamic performance of a vertical-axis tidal-current turbine with different preset angles of attack

    Institute of Scientific and Technical Information of China (English)

    ZHAO Guang; YANG Ran-sheng; LIU Yan; ZHAO Peng-fei

    2013-01-01

    The instantaneous angle of attack on the blade has a significant effect on the hydrodynamic performance of a vertical-axis tidal-current turbine with straight blades.This paper investigates the influence of different preset angles of attack on the hydrodynamic performance of a three-bladed,vertical-axis,tidal-current turbine both experimentally and numerically.Experiments are carried out in a towing tank.This tested turbine's solidity is 0.1146.The preset angles of attack on the blade are-3°,0°,3°,and 5°,in the experiments.Experimental results show that with the increase of the preset angle of attack from-3°,to 5°,the hydrodynamic performance of the turbine is improved significantly with the power coefficients being increased from 15.3% to 34.8%,respectively.Compared to the result of a 0° preset angle of attack,the performance of the turbine with positive preset angles of attack is experimentally demonstrated to be beneficial.This performance improvement is also shown by numerical simulations based on the Unsteady Reynolds Averaged Navier-Stokes (URANS) equations.In addition,the numerical results show that the optimal positive preset angle of attack is 7° for the turbine studied.The corresponding power coefficient is 38%.Beyond this optimal preset angle of attack,the hydrodynamic performance of the turbine decreases.Therefore,due to the dynamic stall phenomenon,an optimal preset angle of attack exists for any vertical-axis turbine.This value should be considered in the design of a vertical-axis tidal-current turbine.

  17. Mechanism of transition in a hypersonic sharp cone boundary layer with zero angle of attack

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Firstly, the steady laminar flow field of a hypersonic sharp cone boundary layer with zero angle of attack was computed. Then, two groups of finite amplitude T-S wave disturbances were introduced at the entrance of the computational field, and the spatial mode transition process was studied by direct numerical simulation (DNS) method.The mechanism of the transition process was analyzed. It was found that the change of the stability characteristics of the mean flow profile was the key issue. Furthermore, the characteristics of evolution for the disturbances of different modes in the hypersonic sharp cone boundary layer were discussed.

  18. Flight Test Techniques for Quantifying Pitch Rate and Angle of Attack Rate Dependencies

    Science.gov (United States)

    Grauer, Jared A.; Morelli, Eugene A.; Murri, Daniel G.

    2017-01-01

    Three different types of maneuvers were designed to separately quantify pitch rate and angle of attack rate contributions to the nondimensional aerodynamic pitching moment coefficient. These maneuvers combined pilot inputs and automatic multisine excitations, and were own with the subscale T-2 and Bat-4 airplanes using the NASA AirSTAR flight test facility. Stability and control derivatives, in particular C(sub mq) and C(sub m alpha(.)) were accurately estimated from the flight test data. These maneuvers can be performed with many types of aircraft, and the results can be used to increase simulation prediction fidelity and facilitate more accurate comparisons with wind tunnel experiments or numerical investigations.

  19. Transition prediction for supersonic and hypersonic boundary layers on a cone with angle of attack

    Institute of Scientific and Technical Information of China (English)

    SU CaiHong; ZHOU Heng

    2009-01-01

    Transition prediction for boundary layers has always been one of the urgent problems waiting for a solution for the development of aero-space technology, yet there is no reliable and effective method due to the complexity of the problem. The eN method has been regarded as an effective method for the transition prediction of boundary layers. However, it heavily relies on experiment or experience. And in cases with three-dimensional base flow, for instance, the boundary layer on a cone with angle of attack, the result of its application is not satisfactory. The authors have found its cause and proposed the method for its improvement, which did yield the fairly satisfactory result for a given test case, and also did not rely so much on experiment or experience. However, before people can really apply this method to practical problems, more test cases have to be studied. In this paper, more test cases for the appli- cation of the improved eN method to problems of transition prediction of supersonic and hypersonic boundary layers on cones with angle of attack will be studied. The results are compared with those obtained by experiments and/or direct numerical simulations, confirming that the improved eN method is effective and reliable. We also find that there may be more than one ZARF for each meridian plane, and which one should be chosen for the eN method has been clarified.

  20. Evaluation of electrolytic tilt sensors for wind tunnel model angle-of-attack (AOA) measurements

    Science.gov (United States)

    Wong, Douglas T.

    1991-01-01

    The results of a laboratory evaluation of three types of electrolytic tilt sensors as potential candidates for model attitude or angle of attack (AOA) measurements in wind tunnel tests are presented. Their performance was also compared with that from typical servo accelerometers used for AOA measurements. Model RG-37 electrolytic tilt sensors were found to have the highest overall accuracy among the three types. Compared with the servo accelerometer, their accuracies are about one order of magnitude worse and each of them cost about two-thirds less. Therefore, the sensors are unsuitable for AOA measurements although they are less expensive. However, the potential for other applications exists where the errors resulting from roll interaction, vibration, and response time are less, and sensor temperature can be controlled.

  1. Evaluation of electrolytic tilt sensors for wind tunnel model angle-of-attack (AOA) measurements

    Science.gov (United States)

    Wong, Douglas T.

    1991-01-01

    The results of a laboratory evaluation of three types of electrolytic tilt sensors as potential candidates for model attitude or angle of attack (AOA) measurements in wind tunnel tests are presented. Their performance was also compared with that from typical servo accelerometers used for AOA measurements. Model RG-37 electrolytic tilt sensors were found to have the highest overall accuracy among the three types. Compared with the servo accelerometer, their accuracies are about one order of magnitude worse and each of them cost about two-thirds less. Therefore, the sensors are unsuitable for AOA measurements although they are less expensive. However, the potential for other applications exists where the errors resulting from roll interaction, vibration, and response time are less, and sensor temperature can be controlled.

  2. Study of optical techniques for the Ames unitary wind tunnels. Part 3: Angle of attack

    Science.gov (United States)

    Lee, George

    1992-01-01

    A review of optical sensors that are capable of accurate angle of attack measurements in wind tunnels was conducted. These include sensors being used or being developed at NASA Ames and Langley Research Centers, Boeing Airplane Company, McDonald Aircraft Company, Arnold Engineering Development Center, National Aerospace Laboratory of the Netherlands, National Research Council of Canada, and the Royal Aircraft Establishment of England. Some commercial sensors that may be applicable to accurate angle measurements were also reviewed. It was found that the optical sensor systems were based on interferometers, polarized light detector, linear or area photodiode cameras, position sensing photodetectors, and laser scanners. Several of the optical sensors can meet the requirements of the Ames Unitary Plan Wind Tunnel. Two of these, the Boeing interferometer and the Complere lateral effect photodiode sensors are being developed for the Ames Unitary Plan Wind Tunnel.

  3. A computational/experimental study of the flow around a body of revolution at angle of attack

    Science.gov (United States)

    Zilliac, Gregory G.

    1986-01-01

    The incompressible Navier-Stokes equations are numerically solved for steady flow around an ogive-cylinder (fineness ration 4.5) at angle of attack. The three-dimensional vortical flow is investigated with emphasis on the tip and the near wake region. The implicit, finite-difference computation is performed on the CRAY X-MP computer using the method of pseudo-compressibility. Comparisons of computational results with results of a companion towing tank experiment are presented for two symmetric leeside flow cases of moderate angles of attack. The topology of the flow is discussed and conclusions are drawn concerning the growth and stability of the primary vortices.

  4. Identification of variations of angle of attack and lift coefficient for a large horizontal-axis wind turbine

    DEFF Research Database (Denmark)

    Rezaeiha, Abdolrahim; Arjomandi, Maziar; Kotsonis, Marios;

    2015-01-01

    The current paper investigates the effects of various elements including turbulence, wind shear, yawed inflow, tower shadow, gravity, mass and aerodynamic imbalances on variations of angle of attack and lift coefficient for a large horizontal-axis wind turbine. It will identify the individual...... and the aggregate effect of elements on variations of mean value and standard deviation of the angle of attack and lift coefficient in order to distinguish the major contributing factors. The results of the current study is of paramount importance in the design of active load control systems for wind turbine....

  5. Effect of angle of attack on the flow past a harbor seal vibrissa shaped cylinder

    Science.gov (United States)

    Kim, Hyo Ju; Yoon, Hyun Sik

    2016-11-01

    The present study considered the geometric disturbance inspired by a harbor seal vibrissa of which undulated surface structures are known as a detecting device to capture the water movement induced by prey fish. In addition, this vibrissa plays an important role to suppress vortex-induced vibration, which has been reported by the previous researches. The present study aims at finding the effect of the angle of attack (AOA) on flow characteristics around the harbor seal vibrissa shaped cylinder, since the flow direction facing the harbor seal vibrissa with the elliptic shape can be changed during the harbor seal's movements and surrounding conditions. Therefore, we considered a wide range of AOA varying from 0 to 90 degree. We carried out large eddy simulation (LES) to investigate the flow around inclined vibrissa shaped cylinder for the Reynolds number (Re) of 500 based hydraulic diameter of a harbor seal vibrissa shape. For comparison, the flow over the elliptic cylinder was also simulated according to AOA at the same Re. The vortical structures of both vibrissa shaped and elliptic cylinders have been compared to identify the fundamental mechanism making the difference flow quantities. This subject is supported by Korea Ministry of Environment (MOE) as "the Chemical Accident Prevention Technology Development Project.", National Research Foundation of Korea (NRF) Grant through GCRCSOP (No.20110030013) and (NRF-2015R1D1A3A01020867).

  6. Flow Control of the Stingray UAV at Low Angles of Attack

    Science.gov (United States)

    Farnsworth, John; Vaccaro, John; Amitay, Michael

    2007-11-01

    The effectiveness of active flow control, via synthetic jets and steady blowing jets, on the aerodynamic performance of the Stingray UAV was investigated experimentally in a wind tunnel. Global flow measurements were conducted using a six component sting balance, static pressure, and Particle Image Velocimetry (PIV) measurements. Using active control for trimming the Stingray UAV in pitch and roll at low angles of attack has similar effects to those with conventional control effectors. The synthetic jets were able to alter the local streamlines through the formation of a quasi-steady interaction region on the suction surface of the vehicle's wing. Phase locked data were acquired to provide insight into the growth, propagation, and decay of the synthetic jet impulse and its interaction with the cross-flow. The changes induced on the moments and forces can be proportionally controlled by either changing the momentum coefficient or by driving the synthetic jets with a pulse modulation waveform. This can lead the way for future development of closed-loop control models.

  7. Experimental investigation of separated shear layer from a leading edge subjected to various angles of attack with tail flap deflections

    Indian Academy of Sciences (India)

    K Anand; S Sarkar

    2015-05-01

    Shear layer development over a thick flat plate with a semi-circular leading edge is investigated for a range of angles of attack under different pressure gradients for a Reynolds number of 2.44×105 (based on chord and free-stream velocity). The characteristics of the separated shear layer are very well documented through a combination of surface pressure measurement and smoke flow visualization. The instability of the separated layer occurs because of enhanced receptivity of perturbations leading to the development of significant unsteadiness and three-dimensional motions in the second-half of the bubble. The onset of separation, transition and the point of reattachment are identified for varying angles of attack and pressure gradients imposed by tail flap deflections. The data concerning bubble length, laminar portion and reattachment points agree well with the literature.

  8. Validation of aerodynamic parameters at high angles of attack for RAE high incidence research models

    Science.gov (United States)

    Ross, A. Jean; Edwards, Geraldine F.; Klein, Vladislav; Batterson, James G.

    1987-01-01

    Two series of free-flight tests have been conducted for combat aircraft configuration research models in order to investigate flight behavior near departure conditions as well as to obtain response data from which aerodynamic characteristics can be derived. The structure of the mathematical model and values for the mathematical derivatives have been obtained through an analysis of the first series, using stepwise regression. The results thus obtained are the bases of the design of active control laws. Flight test results for a novel configuration are compared with predicted responses.

  9. Experimental Flight Characterization of Spin Stabilized Projectiles at High Angle of Attack

    Science.gov (United States)

    2017-08-07

    distribution is unlimited. 25 1 DEFENSE TECHNICAL ( PDF ) INFORMATION CTR DTIC OCA 2 DIRECTOR ( PDF ) US ARMY RSRCH LAB RDRL CIO L IMAL HRA...MAIL & RECORDS MGMT 1 GOVT PRINTG OFC ( PDF ) A MALHOTRA 47 DIR USARL ( PDF ) RDRL WM J S ZABINSKI RDRLWML P J PEREGINO RDRL...2 ARO ( PDF ) S STANTON M MUNSON 2 VTD ( PDF ) C KRONINGER B GLAZ 9 RDECOM AMRDEC ( PDF ) L AUMAN J DOYLE S DUNBAR R MATHUR

  10. Aerodynamic Characteristics of a 10 deg Sharp Cone at Hypersonic Speeds and High Angles of Attack

    Science.gov (United States)

    1975-06-01

    pump arrived at by trial and error. After an ex- and hypodermic needle , served as a self-seal- tensive pretrial period during which several :., Ing...lift and drag coefficients showed good agree- ment with the modified Ncwtonian theory . The ceneli P istributonwsnal the~ ~ ’nelný~(ontiasnuedrl...acceleration, ft/sec Newtonian theory . The centerline K Model geometry and m~iss function distribution was nearly independent of the L Model length, in

  11. Surface Pressure Estimates for Pitching Aircraft Model at High Angles-of-attack (Short Communication)

    OpenAIRE

    A.A. Pashilkar

    2002-01-01

    The surface pressure on a pitching delta wing aircraft is estimated from the normal force and the pitching moment characteristics. The pressure model is based on parametrising the surface pressure distribution on a simple delta wing. This model is useful as a first approximation of the load distribution on the aircraft wing. Leeward surface pressure distributions computed by this method are presented.

  12. Drag prediction for blades at high angle of attack using CFD

    DEFF Research Database (Denmark)

    Sørensen, Niels N.; Michelsen, J.A.

    2004-01-01

    In the present paper it is first demonstrated that state of the art 3D CFD codes are. capable of predicting the correct dependency of the integrated drag of a flat plate placed perpendicular to the flow. This is in strong contrast to previous 2D investigations of infinite plates, where computations...

  13. Aerodynamic characteristics of wind turbine blade airfoils at high angles-of-attack

    NARCIS (Netherlands)

    Timmer, W.A.

    2010-01-01

    Airfoil characteristics at deep stall angles were investigated. It appeared that the maximum drag coefficient as a function of the airfoil upwind y/c ordinate at x/c=0.0125 can be approximated by a straight line. The lift-drag ratios in deep stall of a number of airfoils with moderate lower surface

  14. Investigation of the High Angle of Attack Dynamics of the F-15B Using Bifurcation Analysis

    Science.gov (United States)

    1990-12-01

    region via limit points should not be expected due to asymmetric thrust alone. A large I perturbation may push the F-15 away from the stable branch and...engine thrust setting of 25,000 lbf was then tried in the simu- 3 lation. Fig. 5-16 shows that using the higher thrust asym- metry, the F-15 pushes ...ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION Air Force Institute of Tecnology REPORT NUMBER I WPAFB, OH 45433-6583 AFIT/GAE/ENY/90D-16 9

  15. Surface Pressure Estimates for Pitching Aircraft Model at High Angles-of-attack (Short Communication

    Directory of Open Access Journals (Sweden)

    A. A. Pashilkar

    2002-10-01

    Full Text Available The surface pressure on a pitching delta wing aircraft is estimated from the normal force and the pitching moment characteristics. The pressure model is based on parametrising the surface pressure distribution on a simple delta wing. This model is useful as a first approximation of the load distribution on the aircraft wing. Leeward surface pressure distributions computed by this method are presented.

  16. Numerical Calcultion on Hydrodynamic Characteristic of UUV with Cabin Door Opened at Small Angle of Attack%舱门开启状态下UUV小攻角水动力特性数值模拟

    Institute of Scientific and Technical Information of China (English)

    刘立栋; 张宇文

    2012-01-01

    In order to master hydrodynamic characteristic of UUV whose cabin door is opened at small angle of attack,based on wind tunnel model experiment firstly, it is proved that numerical computation method used is accurate and effective;then the drag,lift and moment characteristic of UUV whose cabin door is opened are calculated numerically by this method,and the influence of load cabin and cabin door on the surface pressure distribution of UUV is analysed after cabin door is opened. The computation result shows that the high pressure difference between the front end and the back end of the load cabin results in a significant increase of the pressare drag of load cabin dragin UUV's, and the drag about zero angle of attack are not symmetrical,the main reason of which is that the pressure drag of load cabin increases with the increase of absolute value of angle of attack on the condition of negative angle of attack. Because of fluid block function of the average pressure on the canbin door's down surface is higher that the up one when the angle of attack is zero degree,so zero lift of UUV is positive,and zero lift angle of attack is about -3 degrees,besides zero moment is positive. Zero moment angle of attack is about -1 degrees.%为了掌握舱门开启状态下UUV小攻角水动力特性,首先基于风洞模型实验验证了所用数值计算方法的准确性与有效性,进而采用该方法对舱门开启状态UUV阻力、升力及力矩特性进行了数值模拟研究,分析了舱门开启后载荷舱及舱门对UUV表面压力分布的影响.计算结果表明,载荷舱前后端面形成的较大压力差,导致舱门开启状态UUV阻力显著提升,且阻力关于零攻角表现为不对称性,主要原因在于负攻角条件下载荷舱粘压阻力随攻角绝对值的增大而增大;由于载荷舱的流体阻滞作用,零攻角工况下舱门下表面平均压力高于上表面,UUV零攻角升力为正,零升力攻角约为-3.,

  17. Convective heat transfer over a wall mounted cube at different angle of attack using large eddy simulation

    Directory of Open Access Journals (Sweden)

    Heidarzadeh Habibollah

    2014-01-01

    Full Text Available Turbulent fluid flow and convective heat transfer over the wall mounted cube in different flow angle of attack have been studied numerically using Large Eddy Simulation. Cube faces and plate have a constant heat flux. Dynamic Smagorinsky (DS subgrid scale model were used in this study. Angles were in the range 0≤θ≤45 and Reynolds number based on the cube height and free stream velocity was 4200. The numerical simulation results were compared with the experimental data of Nakamura et al [6, 7]. Characteristics of fluid flow field and heat transfer compared for four angles of attack. Flow around the cube was classified to four regimes. Results was represented in the form of time averaged normalized streamwise velocity and Reynolds stress in different positions, temperature contours, local and average Nusselt number over the faces of cube. Local convective heat transfer on cube faces was affected by flow pattern around the cube. The local convective heat transfer from the faces of the cube and plate are directly related to the complex phenomena such as horse shoe vortex, arch vortexes in behind the cube, separation and reattachment. Results show that overall convective heat transfer of cube and mean drag coefficient have maximum and minimum value at θ=0 deg and θ=25 deg respectively.

  18. Computational Aerodynamic Analysis of a Micro-CT Based Bio-Realistic Fruit Fly Wing.

    Science.gov (United States)

    Brandt, Joshua; Doig, Graham; Tsafnat, Naomi

    2015-01-01

    The aerodynamic features of a bio-realistic 3D fruit fly wing in steady state (snapshot) flight conditions were analyzed numerically. The wing geometry was created from high resolution micro-computed tomography (micro-CT) of the fruit fly Drosophila virilis. Computational fluid dynamics (CFD) analyses of the wing were conducted at ultra-low Reynolds numbers ranging from 71 to 200, and at angles of attack ranging from -10° to +30°. It was found that in the 3D bio-realistic model, the corrugations of the wing created localized circulation regions in the flow field, most notably at higher angles of attack near the wing tip. Analyses of a simplified flat wing geometry showed higher lift to drag performance values for any given angle of attack at these Reynolds numbers, though very similar performance is noted at -10°. Results have indicated that the simplified flat wing can successfully be used to approximate high-level properties such as aerodynamic coefficients and overall performance trends as well as large flow-field structures. However, local pressure peaks and near-wing flow features induced by the corrugations are unable to be replicated by the simple wing. We therefore recommend that accurate 3D bio-realistic geometries be used when modelling insect wings where such information is useful.

  19. EFFECT OF SWEEP ANGLE ON THE VORTICAL FLOW OVER DELTA WINGS AT AN ANGLE OF ATTACK OF 10°

    Directory of Open Access Journals (Sweden)

    JAMES BRETT

    2014-12-01

    Full Text Available CFD simulations have been used to analyse the vortical flows over sharp edged delta wings with differing sweep angles under subsonic conditions at an angle of attack of 10°. RANS simulations were validated against experimental data for a 65° sweep wing, with a flat cross-section, and the steadiness of the flow field was assessed by comparing the results against unsteady URANS and DES simulations. To assess the effect of sweep angle on the flow field, a range of sweep angles from 65° to 43° were simulated. For moderate sweep wings the primary vortex was observed to detach from the leading edge, undergoing vortex breakdown, and a weaker, replacement, "shadow" vortex was formed. The shadow vortex was observed for sweep angles of 50° and less, and resulted in reduced lift production near the wing tips loss of the stronger primary vortex.

  20. Vortex-induced vibrations of a DU96-W-180 airfoil at 90° angle of attack

    DEFF Research Database (Denmark)

    Skrzypinski, Witold Robert; Gaunaa, Mac; Sørensen, Niels N.;

    2014-01-01

    This work presents an analysis of vortex-induced vibrations of a DU96-W-180 airfoil in deep stall at a 90 degrees angle of attack, based on 2D and 3D Reynolds Averaged Navier Stokes and 3D Detached Eddy Simulation unsteady Computational Fluid Dynamics computations with non-moving, prescribed motion...... and elastically mounted airfoil suspensions. Stationary vortex-shedding frequencies computed in 2D and 3D Computational Fluid Dynamics differed. In the prescribed motion computations, the airfoil oscillated in the direction of the chord line. Negative aerodynamic damping, found in both 2D and 3D Computational...... Fluid Dynamics computations with moving airfoil, showed in the vicinity of the stationary vortex-shedding frequency computed by 2D Computational Fluid Dynamics. A shorter time series was sufficient to verify the sign of the aerodynamic damping in the case of the elastic computations than the prescribed...

  1. Flying qualities design criteria applicable to supersonic cruise aircraft

    Science.gov (United States)

    Chalk, C. R.

    1980-01-01

    A comprehensive set of flying qualities design criteria was prepared for use in the supersonic cruise research program. The framework for stating the design criteria is established and design criteria are included which address specific failures, approach to dangerous flight conditions, flight at high angle of attack, longitudinal and lateral directional stability and control, the primary flight control system, and secondary flight controls. Examples are given of lateral directional design criteria limiting lateral accelerations at the cockpit, time to roll through 30 deg of bank, and time delay in the pilot's command path. Flight test data from the Concorde certification program are used to substantiate a number of the proposed design criteria.

  2. The Effect of Trailing Vortices on the Production of Lift on an Airfoil Undergoing a Constant Rate of Change of Angle of Attack.

    Science.gov (United States)

    1983-12-01

    The purpose of this study was to investigate the effect a trailing vortex wake has on an airfoil undergoing a constant rate of change of angle of...When applied to the constant rate - of - change of angle-of-attack problem, the results showed that a trailing vortex wake has a measurable and

  3. Wing and body kinematics of forward flight in drone-flies.

    Science.gov (United States)

    Meng, Xue Guang; Sun, Mao

    2016-08-15

    Here, we present a detailed analysis of the wing and body kinematics in drone-flies in free flight over a range of speeds from hovering to about 8.5 m s(-1). The kinematics was measured by high-speed video techniques. As the speed increased, the body angle decreased and the stroke plane angle increased; the wingbeat frequency changed little; the stroke amplitude first decreased and then increased; the ratio of the downstroke duration to the upstroke duration increased; the mean positional angle increased at lower speeds but changed little at speeds above 3 m s(-1). At a speed above about 1.5 m s(-1), wing rotation at supination was delayed and that at pronation was advanced, and consequently the wing rotations were mostly performed in the upstroke. In the downstroke, the relative velocity of the wing increased and the effective angle of attack decreased with speed; in the upstroke, they both decreased with speed at lower speeds, and at higher speeds, the relative velocity became larger but the effective angle of attack became very small. As speed increased, the increasing inclination of the stroke plane ensured that the effective angle of attack in the upstroke would not become negative, and that the wing was in suitable orientations for vertical-force and thrust production.

  4. Uncertainty towards the use of the angle-of-attack corrections for eddy-covariance data processing in French ecosystems

    Science.gov (United States)

    Moreaux, Virginie; Delpierre, Nicolas; Dufrêne, Eric; Joffre, Richard; Klumpp, Katja; Loustau, Denis; Berveiller, Daniel; Darsonville, Olivier; Limousin, Jean-Marc; Ourcival, Jean-Marc; Piquemal, Karim; Longdoz, Bernard

    2017-04-01

    The production/absorption of the long lived greenhouse gas (GHG) and the albedo and evapotranspiration fluctuations in forests, grasslands and croplands are responsible of atmospheric radiative forcing but the quantification of these forcings remains uncertain. The CESEC program aims to quantify the impact of climatic drifts or anthropogenic and meteorological events on the ecosystem-atmosphere exchanges of French sites by analysing the long series (at least 9 years between 2003 and 2015) of eddy covariance (EC) fluxes. One part of the CESEC project is to repost-processed homogeneously the raw EC data across the sites and the years to try to reduce the influence of the methodology and experimental design on the temporal and spatial variability. These new processed data are put together with the corresponding climatic and edaphic data and with the carbon stock inventory. A number of French experimental sites have initially used a sonic anemometer from the GILL company, such as the GILL-R3 or the GILL R3-50, coupled with a GHG analyzer to perform EC measurements and deduce GHG exchanges from different ecosystems. Within the data processing procedure of eddy flux measurements, a recent type of correction has raised among the scientific community to account for the angle of attack error due to a distorsion of the flow when the wind approaches these GILL frame-type, resulting in an imperfect sine and cosine response. Nakai and co-authors proposed a correction to compensate for this error, which is expected to improve energy balance closure. No consensus has been clearly made on the application of this correction, but it has mostly been recommanded for recent data processing. The universal flux calculation EddyPro software that we are using in our project, incorporate and recommand this correction. Based on the analysis from two forests ecosystems (FR-Fon and FR-Pue) and a grassland (FR-Lq2) in France, we performed a re-analysis of EC measurements using the corrections

  5. A Simulator Study of the Effectiveness of a Pilot's Indicator which Combined Angle of Attack and Rate of Change of Total Pressure as Applied to the Take-Off Rotation and Climbout of a Supersonic Transport

    Science.gov (United States)

    Hall, Albert W.; Harris, Jack E.

    1961-01-01

    A simulator study has been made to determine the effectiveness of a single instrument presentation as an aid to the pilot in controlling both rotation and climbout path in take-off. The instrument was basically an angle-of-attack indicator, biased with a total-pressure-rate input as a means of suppressing the phugoid oscillation. Linearized six-degree-of-freedom equations of motion were utilized in simulating a hypothetical supersonic transport as the test vehicle. Each of several experienced pilots performed a number of simulated take-offs, using conventional flight instruments and either an angle-of-attack instrument or the combined angle-of-attack and total-pressure-rate instrument. The pilots were able to rotate the airplane, with satisfactory precision, to the 15 deg. angle of attack required for lift-off when using either an angle-of-attack instrument or the instrument which combined total-pressure-rate with angle of attack. At least 4 to 6 second-S appeared to be required for rotation to prevent overshoot, particularly with the latter instrument. The flight paths resulting from take-offs with simulated engine failures were relatively smooth and repeatable within a reasonably narrow band when the combined angle-of-attack and total-pressure-rate instrument presentation was used. Some of the flight paths resulting from take-offs with the same engine-failure conditions were very oscillatory when conventional instruments and an angle-of-attack instrument were used. The pilots considered the combined angle-of-attack and total- pressure-rate instrument a very effective aid. Even though they could, with sufficient practice, perform satisfactory climbouts after simulated engine failure by monitoring the conventional instruments and making correction based on their readings, it was much easier to maintain a smooth flight path with the single combined angle-of-attack and total-pressure-rate instrument.

  6. Physical cleaning of high carbon fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Gray, McMahan L.; Champagne, Kenneth J.; Soong, Yee; Killmeyer, Richard P. [National Energy Technology Laboratory, US Department of Energy, P.O. Box 10940, Cochran Mills Roads, 15236 Pittsburgh, PA (United States); Maroto-Valer, M. Mercedes; Andresen, John M. [The Energy Institute, The Pennsylvania State University, 405 Academic Activities Building, 16802-2308 University Park, PA (United States); Ciocco, Michael V.; Zandhuis, Paul H. [Parson Project Services Inc, National Energy Technology Laboratory, P.O. Box 618, 15129 Library, Pittsburgh, PA (United States)

    2002-04-20

    An industrial fly ash sample was cleaned by three different processes, which were triboelectrostatic separation, ultrasonic column agglomeration, and column flotation. The unburned carbon concentrates were collected at purities ranging up to 62% at recoveries of 62%. In addition, optical microscopy studies were conducted on the final carbon concentrates to determine the carbon forms (inertinite, isotropic coke and anisotropic coke) collected from these various physical-cleaning processes. The effects of the various cleaning processes on the production of different carbon forms from high carbon fly ashes will be discussed.

  7. Computer programs for the calculation of dual sting pitch and roll angles required for an articulated sting to obtain angles of attack and sideslip on wind-tunnel models

    Science.gov (United States)

    Peterson, John B., Jr.

    1991-01-01

    Two programs were developed to calculate the pitch and roll position of the conventional sting drive and the pitch of a high angle articulated sting to position a wind tunnel model at the desired angle of attack and sideslip and position the model as near as possible to the centerline of the tunnel. These programs account for the effects of sting offset angles, sting bending angles, and wind-tunnel stream flow angles. In addition, the second program incorporates inputs form on-board accelerometers that measure model pitch and roll with respect to gravity. The programs are presented and a description of the numerical operation of the programs with a definition of the variables used in the programs is given.

  8. MATHEMATICAL MODEL OF THE MOTION OF A LIGHT ATTACK AIRCRAFT WITH EXTERNAL LOAD SLINGS IN THE EXTREME AREA OF FLIGHT MODES ACCORDING TO THE ANGLE OF ATTACK

    Directory of Open Access Journals (Sweden)

    A. Popov Sergey

    2017-01-01

    Full Text Available For the time being, a combat-capable trainer aircraft has already been used as a light attack aircraft. The quality of mission effectiveness evaluation depends on the degree of relevance of mathematical models used. It is known that the mis- sion efficiency is largely determined by maneuvering capabilities of the aircraft which are realized most fully in extreme angle of attack flight modes. The article presents the study of the effect of Reynolds number, angle of attack and position on the external sling on the parameters characterizing the state of separated-vortex flow, which was conducted using soft- ware complexes such as Solid Works and Ansys Fluent. There given the dependences of the observed parameters for sta- tionary and nonstationary cases of light attack aircraft movement. The article considers the influence of time constants, which characterize the response rate and delaying of separated flow development and attached flow recovery on the state of separated-vortex flow. The author mentions how the speed of angle of attack change influences lift coefficient of a light attack aircraft with external slings due to response rate and delaying of separated flow development and attached flow recovery. The article describes the mathematical model invented by the authors. This is the model of the movements of light attack aircraft with external slings within a vertical flight maneuver, considering the peculiarities of separated-vortex flow. Using this model, there has been obtained the parameters of light attack aircraft output path from the pitch using large an- gles of attack. It is demonstrated that not considering the peculiarities of the separated-vortex flow model of light attack aircraft movements leads to certain increase of height loss at the pullout of the maneuver, which accordingly makes it pos- sible to decrease the height of the beginning of the pullout.

  9. Computer programs for calculation of sting pitch and roll angles required to obtain angles of attack and sideslip on wind tunnel models

    Science.gov (United States)

    Peterson, John B., Jr.

    1988-01-01

    Two programs have been developed to calculate the pitch and roll angles of a wind-tunnel sting drive system that will position a model at the desired angle of attack and and angle of sideslip in the wind tunnel. These programs account for the effects of sting offset angles, sting bending angles and wind-tunnel stream flow angles. In addition, the second program incorporates inputs from on-board accelerometers that measure model pitch and roll with respect to gravity. The programs are presented in the report and a description of the numerical operation of the programs with a definition of the variables used in the programs is given.

  10. Effects of wall cooling and angle of attack on boundary layer transition on sharp cones at free stream Mach 7.4

    Science.gov (United States)

    Mateer, G. G.

    1972-01-01

    Tests were conducted on 5 deg and 15 deg half-angle sharp cones at wall-to-total-temperature ratios of 0.08 to 0.4, and angles of attack from 0 deg to 20 deg. The results indicate that (1) transition Reynolds numbers decrease with decreasing temperature ratio, (2) local transition Reynolds numbers decrease from the windward to the leeward side of the model, and (3) transition data on the windward ray of cones can be correlated in terms of the crossflow velocity gradient, momentum thickness Reynolds number, local Mach number, and cone half-angle.

  11. Experimental study of heat transfer enhancement in solar air heater with different angle of attack of V-down continuous ribs

    Science.gov (United States)

    Istanto, Tri; Danardono, Dominicus; Yaningsih, Indri; Wijayanta, Agung Tri

    2016-06-01

    In this paper, an experimental study on the effect of angle attack in V-down continuous ribs on heat transfer and friction factor in an artificially roughened air heater duct is presented. The electric heater with a constant heat flux as a simulation of the indoor testing solar air heater is used to heat the roughened part of rectangular duct while other parts were insulated. The system and operating conditions were used to decide the range of parameters for the study. The ratio of the width to height of the duct (W/H) was 12, the relative roughness pitch (p/e) was 10, the relative roughness height (e/Dh) was 0.033 and the angle of attack of flow (α) was 30-80°. The air flow rate corresponded to Reynolds number between 3500 -10,000. The result of heat transfer and friction factor had been compared to those for smooth duct under similar flow and thermal boundary condition. The thermo-hydraulic performance also had been considered. As a result, the maximum enhancement of Nusselt number (Nu) and friction factor(f) were 2.34 and 2.45 times, respectively. For each variation of angle attack of flow, the thermo-hydraulic performance has been compared and the result shows that a V-down continuous rib with the angle of attack of flow as 60° gave the best thermo-hydraulic performance.

  12. Effect of aerodynamic and angle-of-attack uncertainties on the blended entry flight control system of the Space Shuttle from Mach 10 to 2.5

    Science.gov (United States)

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

    1984-01-01

    A six-degree-of-freedom simulation analysis has been performed for the Space Shuttle Orbiter during entry from Mach 10 to 2.5 with realistic off-nominal conditions using the entry flight control system specified in May 1978. The off-nominal conditions included the following: (1) aerodynamic uncertainties, (2) an error in deriving the angle of attack from onboard instrumentation, (3) the failure of two of the four reaction control-system thrusters on each side, and (4) a lateral center-of-gravity offset. With combinations of the above off-nominal conditions, the control system performed satisfactorily with a few exceptions. The cases that did not exhibit satisfactory performance displayed the following main weaknesses. Marginal performance was exhibited at hypersonic speeds with a sensed angle-of-attack error of 4 deg. At supersonic speeds the system tended to be oscillatory, and the system diverged for several cases because of the inability to hold lateral trim. Several system modifications were suggested to help solve these problems and to maximize safety on the first flight: alter the elevon-trim and speed-brake schedules, delay switching to rudder trim until the rudder effectiveness is adequate, and reduce the overall rudder loop gain. These and other modifications were incorporated in a flight-control-system redesign in May 1979.

  13. Transition prediction of a hypersonic boundary layer over a cone at small angle of attack--with the improvement of eN method

    Institute of Scientific and Technical Information of China (English)

    SU CaiHong; ZHOU Heng

    2009-01-01

    The problem of transition prediction for hypersonic boundary layers over a sharp cone has been stud-ied in this work. The Mach number of the oncoming flow is 6, the cone half-angle is 5Ω, and the angle of attack is 1Ω. The conventional eN method is used, but the transition location so obtained is obviously incorrect. The reason is that in the conventional method, only the amplifying waves are taken into ac-count, while in fact, for different meridians the decay processes of the disturbances before they begin to grow are different. Based on our own previous work, new interpretation and essential improvement for the eN method are proposed. Not only the amplification process but also the decay process is con-sidered. The location, where by linear stability theory, the amplitude of disturbance wave is amplified from its initial small value to 1%, is considered to be the transition location. The new result for transi-tion prediction thus obtained is found to be fairly satisfactory. It is also indicated that for the calculation of base flow, boundary layer equations can be used for a small angle of attack. Its computational cost is much smaller than those for DNS.

  14. High-Flying High-Poverty Schools

    Science.gov (United States)

    American Educator, 2013

    2013-01-01

    In discussing socioeconomic integration before audiences, the author is frequently asked: What about high-poverty schools that do work? Don't they suggest that economic segregation isn't much of a problem after all? High-poverty public schools that beat the odds paint a heartening story that often attracts considerable media attention. In 2000,…

  15. A computer program for the calculation of the flow field including boundary layer effects for mixed-compression inlets at angle of attack

    Science.gov (United States)

    Vadyak, J.; Hoffman, J. D.

    1982-01-01

    A computer program was developed which is capable of calculating the flow field in the supersonic portion of a mixed compression aircraft inlet operating at angle of attack. The supersonic core flow is computed using a second-order three dimensional method-of-characteristics algorithm. The bow shock and the internal shock train are treated discretely using a three dimensional shock fitting procedure. The boundary layer flows are computed using a second-order implicit finite difference method. The shock wave-boundary layer interaction is computed using an integral formulation. The general structure of the computer program is discussed, and a brief description of each subroutine is given. All program input parameters are defined, and a brief discussion on interpretation of the output is provided. A number of sample cases, complete with data listings, are provided.

  16. Wind-tunnel force and flow visualization data at Mach numbers from 1.6 to 4.63 for a series of bodies of revolution at angles of attack from minus 4 deg to 60 deg

    Science.gov (United States)

    Landrum, E. J.; Babb, C. D.

    1979-01-01

    Flow visualization and force data for a series of six bodies of revolution are presented without analysis. The data were obtained in the Langley Unitary Plan wind tunnel for angles of attack from -4 deg to 60 deg. The Reynolds number used for these tests was 6,600,000 per meter.

  17. Activated blended cement containing high volume coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Shi, C.J.; Qian, J.S. [CJS Technology Inc., Burlington, ON (Canada)

    2001-10-01

    This study investigated the strength and equilibrium water extraction of blended cement containing high volume coal fly ash and activator CaCl{sub 2}. The addition of CaCl{sub 2} increased the strength of cement very significantly. Equilibrium water extraction indicated that the addition of CaCl{sub 2} decreased the pH of the pore solution, but accelerated the pozzolanic reactions between coal fly ash and lime, which became more obvious when the volume of fly ash in the cement was increased from 50-70%. Results from both strength and water extraction testing could conclude that CaCl{sub 2} is a good activator for the activation of pozzolanic reactivity of fly ash and for the improvement of early properties of fly ash cement and concrete.

  18. A computer program for calculating the perfect gas inviscid flow field about blunt axisymmetric bodies at an angle of attack of 0 deg

    Science.gov (United States)

    Zoby, E. V.; Graves, R. A., Jr.

    1973-01-01

    A method for the rapid calculation of the inviscid shock layer about blunt axisymmetric bodies at an angle of attack of 0 deg has been developed. The procedure is of an inverse nature, that is, a shock wave is assumed and calculations proceed along rays normal to the shock. The solution is iterated until the given body is computed. The flow field solution procedure is programed at the Langley Research Center for the Control Data 6600 computer. The geometries specified in the program are sphores, ellipsoids, paraboloids, and hyperboloids which may conical afterbodies. The normal momentum equation is replaced with an approximate algebraic expression. This simplification significantly reduces machine computation time. Comparisons of the present results with shock shapes and surface pressure distributions obtained by the more exact methods indicate that the program provides reasonably accurate results for smooth bodies in axisymmetric flow. However, further research is required to establish the proper approximate form of the normal momentum equation for the two-dimensional case.

  19. Experimental Evaluation of the Effect of Angle-of-attack on the External Aerodynamics and Mass Capture of a Symmetric Three-engine Air-breathing Launch Vehicle Configuration at Supersonic Speeds

    Science.gov (United States)

    Kim, Hyun D.; Frate, Franco C.

    2001-01-01

    A subscale aerodynamic model of the GTX air-breathing launch vehicle was tested at NASA Glenn Research Center's 10- by 10-Foot Supersonic Wind Tunnel from Mach 2.0 to 3.5 at various angles-of-attack. The objective of the test was to investigate the effect of angle-of-attack on inlet mass capture, inlet diverter effectiveness, and the flowfield at the cowl lip plane. The flow-through inlets were tested with and without boundary-layer diverters. Quantitative measurements such as inlet mass flow rates and pitot-pressure distributions in the cowl lip plane are presented. At a 3deg angle-of-attack, the flow rates for the top and side inlets were within 8 percent of the zero angle-of-attack value, and little distortion was evident at the cowl lip plane. Surface oil flow patterns showing the shock/boundary-layer interaction caused by the inlet spikes are shown. In addition to inlet data, vehicle forebody static pressure distributions, boundary-layer profiles, and temperature-sensitive paint images to evaluate the boundary-layer transition are presented. Three-dimensional parabolized Navier-Stokes computational fluid dynamics calculations of the forebody flowfield are presented and show good agreement with the experimental static pressure distributions and boundary-layer profiles. With the boundary-layer diverters installed, no adverse aerodynamic phenomena were found that would prevent the inlets from operating at the required angles-of-attack. We recommend that phase 2 of the test program be initiated, where inlet contraction ratio and diverter geometry variations will be tested.

  20. 小迎角纵向不稳定飞机起飞安全性分析%Take-off safety analysis of aircraft with longitudinal static instability at low angles of attack

    Institute of Scientific and Technical Information of China (English)

    耿建中; 姚海林; 段卓毅

    2013-01-01

    由于螺旋桨滑流的影响,某运输机起飞构型在小迎角时纵向稳定性裕度不足,甚至不稳定,给飞机带来安全隐患.分析了某运输机起飞构型纵向力矩特性,讨论了螺旋桨滑流对纵向静稳定性的影响、影响飞机起飞时的安全因素和进入小迎角飞行的条件,建立了飞机起飞的数学仿真模型,通过大量的仿真计算,研究了突风和驾驶员误操纵对飞机起飞安全性的影响,给出了起飞时飞机所能抗御的最大突风速度.研究结果表明,某运输机小迎角稳定裕度不足,不稳定对飞机安全起飞的影响可以不予考虑.%The propeller slipstream result in longitudinal stability margin insufficient,even static instability at low angles of attack of an aircraft,which may cause potential problem. In order to study the effect of the static instability on take-off safety,the effect of propeller slipstream on longitudinal static stability was discussed. The pitching moment characteristic,the factor which has effect on safe take-off,and the con-ditons which may cause an aircraft flying at low angles attack were analyzed. Building dynamic model,the influence of gust and the pilot misoperation on the take-off safety were studied through computation and simulation. The maximum velocity of gust that an aircraft can resist was given. The result indicates the effect of the static instability on the take-off safety can be neglected.

  1. Three-Dimensional Inviscid Flow About Supersonic Blunt Cones at Angle of Attack - III: Coupled Subsonic and Supersonic Programs for Inviscid Three-Dimensional Flow

    Energy Technology Data Exchange (ETDEWEB)

    Abbett, M. J.; Fort, R.

    1968-09-01

    The three-dimensional ideal gas flow in the shock layer of a blunted supersonic cone at an angle of attack is calculated using two asymptotic solutions. The first solution calculates the steady state flow in the subsonic nose region by obtaining a time-dependent solution of the hyperbolic equations using numerical techniques. Internal, nonboundary points are calculated using a Lax-Wendroff numerical type technique. Boundary points, shock and body surface, are computed using a time-dependent method of characteristics. When a steady state solution is reached the flow properties on a surface of constant {theta}, (where the Mach number is everywhere > 1) are used for initial data for the afterbody solution. The afterbody solution, using polar coordinates (r, {theta}, {phi}) assumes at r{sub 0} an arbitrary set of initial conditions provided by the nose region solution and computes the downstream flow as a function of {theta}, {phi}, and r until an asymptotic state independent of r develops. The interior mesh points are again calculated using a Lax- Wendroff type technique and the boundary points by a method of characteristics. This report covers the coupling of the time-dependent and radius (r) dependent solutions. Instructions are given for the operation of the resulting Fortran code. The type of input data required is detailed and sample output is provided. Output data is given in two sets of coordinates. One is wind orientated; the other set is given in body orientated coordinates; The analytical transformation from one coordinate system to the other is given.

  2. Size fraction characterization of highly-calcareous fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Itskos, Grigorios; Koukouzas, Nikolaos [Institute for Solid Fuels Technology and Applications, Centre for Research and Technology Hellas, 357-359 Mesogeion Avenue, GR-152 31, Halandri, Athens (Greece); Itskos, Socrates [Department of Chemical Technology and the Environment, Steam Electric Station of Amynteon-Filotas, Public Power Corporation of Greece, GR-532 00, Amynteon (Greece)

    2010-11-15

    The chemical and mineralogical composition of lignite fly ash (FA) varies as a function of the prevalent conditions in both the processes of power production and lignite mining. The differentiation of the qualitative and quantitative composition of the highly-calcareous lignite fly ash, as a function of its particle size distribution, is verified in this paper. According to the results of the conducted research, a fine-grained fraction of considerable amount presents properties that obstruct the sustainable exploitation of calcareous lignite fly ash in cement industry applications. On the other hand, the same grain fraction (because of its hydraulic properties) can be utilized in other sort of applications, based on different criteria, i.e. in road constructions. The coarse-grained fraction (which reflects a low proportion to the total fly ash output) presents the same undesired characteristics as well. Rather, the intermediate grain fraction (75-150 {mu}m) presents the highly desirable properties when fly ash is utilized as a pozzolanic additive. In addition, the mechanism of the formation of the intermediate grain fraction strongly prevents the factors that cause the variation of fly ash-quality. It is therefore the optimum part of the whole amount of lignite FA, to be utilized as additive in cement manufacturing. The outcomes of this paper will hopefully contribute towards the crucial goal of the expansion of the utilization of calcareous lignite fly ash by proposing a more effective way of using this material, basically by taking advantage of its fundamental chemical and mineralogical properties. (author)

  3. High filler concrete using fly ash. Chloride penetration and microstructure

    NARCIS (Netherlands)

    Valcke, S.L.A.; Polder, R.B.; Nijland, T.G.; Leegwater, G.A.; Visser, J.H.M.; Bigaj-van Vliet, A.J.

    2012-01-01

    Most high filler concrete studies are based on relatively high contents of powder (cement + filler) (>400 kg m-3). This paper aims to increase the total fly ash content relative to the clinker content, while simultaneously minimizing the total powder content in the concrete to values lower than 300

  4. Avian wing geometry and kinematics of a free-flying barn owl in flapping flight

    Science.gov (United States)

    Wolf, Thomas; Konrath, Robert

    2015-02-01

    This paper presents results of high-resolution three-dimensional wing shape measurements performed on free-flying barn owls in flapping flight. The applied measurement technique is introduced together with a moving camera set-up, allowing for an investigation of the free flapping flight of birds with high spatial and temporal resolution. Based on the three-dimensional surface data, a methodology for parameterizing the wing profile along with wing kinematics during flapping flight has been developed. This allowed a description of the spanwise varying kinematics and aerodynamic parameters (e.g. effective angles of attack, camber, thickness) of the wing in dependence on the flapping phase. The results are discussed in detail using the data of a single flight, whereas a comparison of some kinematic parameters obtained from different flights is given too.

  5. Sorbents for CO2 capture from high carbon fly ashes.

    Science.gov (United States)

    Maroto-Valer, M Mercedes; Lu, Zhe; Zhang, Yinzhi; Tang, Zhong

    2008-11-01

    Fly ashes with high-unburned-carbon content, referred to as fly ash carbons, are an increasing problem for the utility industry, since they cannot be marketed as a cement extender and, therefore, have to be disposed. Previous work has explored the potential development of amine-enriched fly ash carbons for CO2 capture. However, their performance was lower than that of commercially available sorbents, probably because the samples investigated were not activated prior to impregnation and, therefore, had a very low surface area. Accordingly, the work described here focuses on the development of activated fly ash derived sorbents for CO2 capture. The samples were steam activated at 850 degrees C, resulting in a significant increase of the surface area (1075 m2/g). The activated samples were impregnated with different amine compounds, and the resultant samples were tested for CO2 capture at different temperatures. The CO2 adsorption of the parent and activated samples is typical of a physical adsorption process. The impregnation process results in a decrease of the surface areas, indicating a blocking of the porosity. The highest adsorption capacity at 30 and 70 degrees C for the amine impregnated activated carbons was probably due to a combination of physical adsorption inherent from the parent sample and chemical adsorption of the loaded amine groups. The CO2 adsorption capacities for the activated amine impregnated samples are higher than those previously published for fly ash carbons without activation (68.6 vs. 45 mg CO2/g sorbent).

  6. Understanding a way to fly high

    Science.gov (United States)

    Plummer, John

    2016-08-01

    David Rugg is the Senior Engineering Fellow in Materials at Rolls-Royce plc. He talks to Nature Materials about the need to understand scientific fundamentals to develop reliable and high-performance materials for jet engines, and the importance of university collaborations.

  7. Activation of fly ashes by the high temperature and high alkalinity in ASR tests

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    High temperature and high alkalinity are typical testing conditions to accelerate the appraisal process of the suppressing effect of fly ashes on alkali silica reaction(ASR),but the reaction mechanism of fly ashes would be quite different under such conditions compared to the normal condition of temperature and alkalinity.To make a reasonable analysis of the suppressing effect of fly ashes,13 types of fly ashes were tested in this paper by both the accelerated mortar bar test method and the 60°C accelerated concrete prism test method.The results showed that the effect of fly ashes would be magnified under the condition of high temperature and high alkalinity.The XRD analysis showed that all the phases of fly ash could react with the hot alkaline solution except for mullite and a small amount of quartz.Fly ash could be significantly activated by the 80°C 1 mol/L NaOH solution,and form mainly C-S-H phase and P type zeolite,but its effect on inhibiting ASR was exaggerated then.According to the mortar strength test and the ASR suppressing test results,C-S-H phase contributed to mortar strength,but its amount did not decide the ASR suppressing effect of fly ash.

  8. Radiological and material characterization of high volume fly ash concrete.

    Science.gov (United States)

    Ignjatović, I; Sas, Z; Dragaš, J; Somlai, J; Kovács, T

    2017-03-01

    The main goal of research presented in this paper was the material and radiological characterization of high volume fly ash concrete (HVFAC) in terms of determination of natural radionuclide content and radon emanation and exhalation coefficients. All concrete samples were made with a fly ash content between 50% and 70% of the total amount of cementitious materials from one coal burning power plant in Serbia. Physical (fresh and hardened concrete density) and mechanical properties (compressive strength, splitting tensile strength and modulus of elasticity) of concrete were tested. The radionuclide content ((226)Ra, (232)Th and (40)K) and radon massic exhalation of HVFAC samples were determined using gamma spectrometry. Determination of massic exhalation rates of HVFAC and its components using radon accumulation chamber techniques combined with a radon monitor was performed. The results show a beneficial effect of pozzolanic activity since the increase in fly ash content resulted in an increase in compressive strength of HVFAC by approximately 20% for the same mass of cement used in the mixtures. On the basis of the obtained radionuclide content of concrete components the I -indices of different HVFAC samples were calculated and compared with measured values (0.27-0.32), which were significantly below the recommended 1.0 index value. The prediction was relatively close to the measured values as the ratio between the calculated and measured I-index ranged between 0.89 and 1.14. Collected results of mechanical and radiological properties and performed calculations clearly prove that all 10 designed concretes with a certain type of fly ash are suitable for structural and non-structural applications both from a material and radiological point of view. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Numerical simulation of a delta wing at high angles of attack%三角翼大迎角绕流的数值模拟

    Institute of Scientific and Technical Information of China (English)

    康顺; 杜永乐; 祁明旭

    2005-01-01

    采用FINETM/HEXA非结构网格流场计算软件包对三角翼飞行器的低速大迎角绕流进行了数值模拟.结果表明,计算值与实验数据符合较好,采用Agglomeration 方法能大幅度提高收敛速度,而网格自适应方法用总体不大的网格单元数可较精细地模拟流场.本文还分析了前缘分离涡破裂前后的流动现象和旋涡横截面流线图谱的变化规律.

  10. The PELskin project-part V: towards the control of the flow around aerofoils at high angle of attack using a self-activated deployable flap

    OpenAIRE

    2016-01-01

    During the flight of birds, it is often possible to notice that some of the primaries and covert feathers on the upper side of the wing pop-up under critical flight conditions, such as the landing approach or when stalking their prey (see Fig. 1) . It is often conjectured that the feathers pop up plays an aerodynamic role by limiting the spread of flow separation . A combined experimental and numerical study was conducted to shed some light on the physical mechanism determining the feathers s...

  11. Investigation of the Influence of Rotary Aerodynamics on the Study of High Angle of Attack Dynamics of the F-15B Using Bifurcation Analysis

    Science.gov (United States)

    1991-12-01

    i. The equilibrium solutions are stable for 1ɘ and- unstable for X>O with a loss of stability at X=O. Using polar coordinates y = rcosO, y2 = sinO...PC(,23)BDE C9 =PC(I,24)*B*A + PC(I,25)*OM’DD + PC(,26)* BDD C10 = PC(,27)’OM*DR + PC(I,28)*DA*OMOM +PC(1,29)*DAA Cll = PC(1,30)’DD*DDB+PC(1,31 )0MOMA...PC(1,32)*OMOM*OM C12 = PC(1,33)ABB +i PC(,34)*B*AOM C13 = PC(,35)BA*DR + PC(,36)A* BDD + PC(1,37)B*BOM C14 = PC(,38)’DD*OMOM + PC(,39)*BDA*OM C15 = PC

  12. Fly Eye radar: detection through high scattered media

    Science.gov (United States)

    Molchanov, Pavlo; Gorwara, Ashok

    2017-05-01

    Longer radio frequency waves better penetrating through high scattered media than millimeter waves, but imaging resolution limited by diffraction at longer wavelength. Same time frequency and amplitudes of diffracted waves (frequency domain measurement) provides information of object. Phase shift of diffracted waves (phase front in time domain) consists information about shape of object and can be applied for reconstruction of object shape or even image by recording of multi-frequency digital hologram. Spectrum signature or refracted waves allows identify the object content. Application of monopulse method with overlap closely spaced antenna patterns provides high accuracy measurement of amplitude, phase, and direction to signal source. Digitizing of received signals separately in each antenna relative to processor time provides phase/frequency independence. Fly eye non-scanning multi-frequency radar system provides simultaneous continuous observation of multiple targets and wide possibilities for stepped frequency, simultaneous frequency, chaotic frequency sweeping waveform (CFS), polarization modulation for reliable object detection. Proposed c-band fly eye radar demonstrated human detection through 40 cm concrete brick wall with human and wall material spectrum signatures and can be applied for through wall human detection, landmines, improvised explosive devices detection, underground or camouflaged object imaging.

  13. Description of the High Resolution Fly's Eye Detector

    Science.gov (United States)

    HIRES Collaboration

    The High Resolution Fly's Eye experiment measures properties of the highest energy cosmic rays. The air fluorescence technique used in HiRes was previously demonstrated by the original Fly's Eye detector. The HiRes Observatory is the realization of the next stage of air fluorescence observation of ultra high energy cosmic rays. The observatory has been operating in various sub-configurations since spring of 1997. HiRes has been operating in its full design configuration utilizing two detector sites to provide stereoscopic observations since the fall of 1999. A brief description of the detectors as well as the techniques used to observe and measure ultra high energy cosmic ray showers are the subject of this paper. 1 The Technique Above 1017 eV, the flux of cosmic ray particles is so low that direct detection of the primary particles becomes in-feasible. The traditional method to extend measurements into this region has been to observe Extensive Air Showers (EAS), produced in the Earth's atmosphere, by the primary cosmic ray particles. An Ultra High Energy Cosmic Ray (UHECR) collides with a nucleus (nitrogen or oxygen) in the atmosphere resulting in the formation of an EAS containing billions of secondary particles. The EAS is a cascade of charged particles that develops over 10's of km eventually becoming a pancake a few hundred meters wide and a few meters thick moving at nearly the speed of light. As the EAS traverses the atmosphere, it excites air molecules. The molecules fall back into their ground state emitting light. The light is emitted almost exclusively from nitrogen molecules in the wavelength region from 300-400 nm. The amount of light emitted corresponds to roughly 4 5 photons per meter per ionizing particle. (Kakimoto 1996) There are such an enormous number of ionizing particles (billions at shower

  14. Production of fired construction brick from high sulfate-containing fly ash with boric acid addition.

    Science.gov (United States)

    Başpinar, M Serhat; Kahraman, Erhan; Görhan, Gökhan; Demir, Ismail

    2010-01-01

    The increase of power plant capacity has led to the production of an increasing amount of fly ash that causes high environmental impact in Turkey. Some of the fly ash is utilized within the fired brick industry but high sulfate-containing fly ash creates severe problems during sintering of the fired brick. This study attempted to investigate the potential for converting high sulfate-containing fly ash into useful material for the construction industry by the addition of boric acid. The chemical and mineralogical composition of fly ash and clay were investigated. Boric acid (H(3)BO(3)) was added to fly ash-clay mixtures with up to 5 wt.%. Six different series of test samples were produced by uniaxial pressing. The samples were fired at the industrial clay-brick firing temperatures of 800, 900 and 1000 degrees C. The microstructures of the fired samples were investigated by scanning electron microscopy and some physical and mechanical properties were measured. It was concluded that the firing at conventional brick firing temperature of high sulfate fly ash without any addition of boric acid resulted in very weak strength bricks. The addition of boric acid and clay simultaneously to the high sulfate- containing fly ash brick dramatically increased the compressive strength of the samples at a firing temperature of 1000 degrees C by modifying the sintering behaviour of high sulfate fly ash.

  15. Aerodynamic performances of cruise missile flying above local terrain

    Science.gov (United States)

    Ahmad, A.; Saad, M. R.; Che Idris, A.; Rahman, M. R. A.; Sujipto, S.

    2016-10-01

    Cruise missile can be classified as a smart bomb and also Unmanned Aerial Vehicle (UAV) due to its ability to move and manoeuvre by itself without a pilot. Cruise missile flies in constant velocity in cruising stage. Malaysia is one of the consumers of cruise missiles that are imported from other nations, which can have distinct geographic factors including their local terrains compared to Malaysia. Some of the aerodynamic performances of missile such as drag and lift coefficients can be affected by the local geographic conditions in Malaysia, which is different from the origin nation. Therefore, a detailed study must be done to get aerodynamic performance of cruise missiles that operate in Malaysia. The effect of aerodynamic angles such as angle of attack and side slip can be used to investigate the aerodynamic performances of cruise missile. Hence, subsonic wind tunnel testings were conducted to obtain the aerodynamic performances of the missile at various angle of attack and sideslip angles. Smoke visualization was also performed to visualize the behaviour of flow separation. The optimum angle of attack found was at α=21° and side slip, β=10° for optimum pitching and yawing motion of cruise missile.

  16. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash.

    Science.gov (United States)

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-08-21

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  17. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2015-08-01

    Full Text Available Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  18. Durability Study on High Calcium Fly Ash Based Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Ganesan Lavanya

    2015-01-01

    Full Text Available This study presents an investigation into the durability of geopolymer concrete prepared using high calcium fly ash along with alkaline activators when exposed to 2% solution of sulfuric acid and 5% magnesium sulphate for up to 45 days. The durability was also assessed by measuring water absorption and sorptivity. Ordinary Portland cement concrete was also prepared as control concrete. The grades chosen for the investigation were M20, M40, and M60. The alkaline solution used for present study is the combination of sodium silicate and sodium hydroxide solution with the ratio of 2.50. The molarity of sodium hydroxide was fixed as 12. The test specimens were 150×150×150 mm cubes, 100×200 mm cylinders, and 100×50 mm discs cured at ambient temperature. Surface deterioration, density, and strength over a period of 14, 28, and 45 days were observed. The results of geopolymer and ordinary Portland cement concrete were compared and discussed. After 45 days of exposure to the magnesium sulfate solution, the reduction in strength was up to 12% for geopolymer concrete and up to 25% for ordinary Portland cement concrete. After the same period of exposure to the sulphuric acid solution, the compressive strength decrease was up to 20% for geopolymer concrete and up to 28% for ordinary Portland cement concrete.

  19. Properties of High-Volume Fly Ash Concrete Reinforced with Natural Fibres

    Directory of Open Access Journals (Sweden)

    Rafat SIDDIQUE

    2012-12-01

    Full Text Available Properties of high-volume fly ash concrete incorporating san fibres are presented in this paper. For this investigation, initially, three concrete mixtures were made with 35%, 45%, and 55% of Class F fly as partial replacement of cement. After this, three percentages (0.25, 0.50, and 0.75% of san fibres (25 mm length were added in each of the fly ash concrete mixtures. San is a natural bast fibre, and is also known as Sunn Hemp (Botanical name: Crotalaria Juncea. It is grown in Indian Sub-Continent, Brazil, Eastern and Southern Africa, and also in some parts of U.S.A. Tests were performed for compressive strength, splitting tensile strength, flexural strength, and impact strength at the ages of 28, 91 and 365 days. Tests were also performed for fresh concrete properties. 28 days test results indicated that san fibres reduced the compressive strength of high-volume fly ash concrete by 2 to 13%, increased splitting tensile strength by 6 to 26%, flexural strength by 5 to 14%, and enhanced impact strength tremendously (by 100 to 300% depending upon the fly ash content and fibre percentage. Later age (91 and 365 days results showed continuous increase in strength properties of high-volume fly ash concrete. This was probably be possible due to the pozzolanic action of fly ash, leading to more densification of the concrete matrix, and development of more effective bond between fibres and fly ash concrete matrix.

  20. Adaptive-Repetitive Visual-Servo Control of Low-Flying Aerial Robots via Uncalibrated High-Flying Cameras

    Science.gov (United States)

    Guo, Dejun; Bourne, Joseph R.; Wang, Hesheng; Yim, Woosoon; Leang, Kam K.

    2017-08-01

    This paper presents the design and implementation of an adaptive-repetitive visual-servo control system for a moving high-flying vehicle (HFV) with an uncalibrated camera to monitor, track, and precisely control the movements of a low-flying vehicle (LFV) or mobile ground robot. Applications of this control strategy include the use of high-flying unmanned aerial vehicles (UAVs) with computer vision for monitoring, controlling, and coordinating the movements of lower altitude agents in areas, for example, where GPS signals may be unreliable or nonexistent. When deployed, a remote operator of the HFV defines the desired trajectory for the LFV in the HFV's camera frame. Due to the circular motion of the HFV, the resulting motion trajectory of the LFV in the image frame can be periodic in time, thus an adaptive-repetitive control system is exploited for regulation and/or trajectory tracking. The adaptive control law is able to handle uncertainties in the camera's intrinsic and extrinsic parameters. The design and stability analysis of the closed-loop control system is presented, where Lyapunov stability is shown. Simulation and experimental results are presented to demonstrate the effectiveness of the method for controlling the movement of a low-flying quadcopter, demonstrating the capabilities of the visual-servo control system for localization (i.e.,, motion capturing) and trajectory tracking control. In fact, results show that the LFV can be commanded to hover in place as well as track a user-defined flower-shaped closed trajectory, while the HFV and camera system circulates above with constant angular velocity. On average, the proposed adaptive-repetitive visual-servo control system reduces the average RMS tracking error by over 77% in the image plane and over 71% in the world frame compared to using just the adaptive visual-servo control law.

  1. 不同攻角下AUV回收过程中的水动力规律%Research on the Law of the Hydrodynamic During AUV Recovery under Different Angle of Attack

    Institute of Scientific and Technical Information of China (English)

    潘光; 王培; 杜晓旭

    2012-01-01

    通过对AUV(Autonomous Underwater Vehicle)回收过程中运动规律的研究和对纳维—斯托克斯方程(Navier-Stokes equations)及其求解方法的分析,基于CFD(Computational Fluid Dynamics)理论建立了AUV回收运动的三维计算模型,并使用CFD软件完成其物理模型的建立、网格的划分及求解设置.在此基础上对AUV回收过程中的阻力、升力干扰进行分析计算,得到不同攻角下AUV所受到的水动力干扰与AUV和回收平台之间距离的相互联系.%By studying the law of motion of AUV recovery process and analyzing Navier-Stokes equations (Navier-Stokes equations) and its solution.the three-dimensional model of the AUV recovery movement is established based on CFD Theory,and then CFD software is used to finish the build of the physical model,the partition of the mesh and solution set. On this basis, drag and lift interference have been calculated in the process of the AUV recovery. The relationship between AUV hydrodynamic interference suffered by different angle of attack and the distance between recovery platform and AUV is obtained.

  2. The Effects of High Alkaline Fly Ash on Strength Behaviour of a Cohesive Soil

    Directory of Open Access Journals (Sweden)

    A. Binal

    2016-01-01

    Full Text Available Contemporarily, there are 16 coal-burning thermal power plants currently operating in Turkey. This number is expected to rise to 46 in the future. Annually, about 15 million tons of fly ash are removed from the existing thermal power plants in Turkey, but a small proportion of it, 2%, is recyclable. Turkey’s plants are fired by lignite, producing Class C fly ash containing a high percentage of lime. Sulfate and alkali levels are also higher in Class C fly ashes. Therefore, fly ash is, commonly, unsuitable as an additive in cement or concrete in Turkey. In this study, highly alkaline fly ash obtained from the Yeniköy thermal power plants is combined with soil samples in different proportions (5%, 10%, 15%, 20%, and 25% and changes in the geomechanical properties of Ankara clay were investigated. The effect of curing time on the physicomechanical properties of the fly ash mixed soil samples was also analyzed. The soil classification of Ankara clay changed from CH to MH due to fly ash additives. Free swelling index values showed a decrease of 92.6%. Direct shear tests on the cohesion value of Ankara clay have shown increases by multiples of 15.85 and 3.01 in internal friction angle values. The California bearing ratio has seen a more drastic increase in value (68.7 times for 25% fly ash mix.

  3. DYNAMIC ANALYSIS OF PARTICLE FLYING VELOCITY IN HIGH VELOCITY OXYGEN FUEL SPRAY

    Institute of Scientific and Technical Information of China (English)

    Wang Zhiping; Dong Zujue; Huo Shubin

    2000-01-01

    Based on gas dynamics,thermodynamics,fluid dynamics of multiphase systems and other theories,the dynamic analyses of the particle flying velocity in a high velocity oxygen fuel spray (HVOF) is accomplished.The relationships between the flying velocity of a particle and the flying time or flying length,particle size,hot gas velocity,and pressure or density of the gas are proposed.Meanwhile,the influences of the velocity and mass rate of flow of the flame gas of a HVOF gun,and particle size on the particle flying velocity are discussed in detail.The dynamic pressure concept is introduced to express the flow capacity of hot gas of a HVOF gun,and the relationship between the dynamic pressure of a HVOF gun and the velocity of a particle for depositing is presented.

  4. Experimental static aerodynamic forces and moments at high subsonic speeds on a missile model during simulated launching from the midsemispan location of a 45 degree sweptback wing-fuselage-pylon combination

    Science.gov (United States)

    Alford, William J; King, Thomas, Jr

    1957-01-01

    An investigation was made at high subsonic speeds in the Langley high-speed 7- by 10-foot tunnel to determine the static aerodynamic forces and moments on a missile model during simulated launching from the midsemispan location of a 45 degree sweptback wing-fuselage-pylon combination. The results indicated significant variations in all the aerodynamic components with changes in chordwise location of the missile. Increasing the angle of attack caused increases in the induced effects on the missile model because of the wing-fuselage-pylon combination. Increasing the Mach number had little effect on the variations of the missile aerodynamic characteristics with angle of attack except that nonlinearities were incurred at smaller angles of attack for the higher Mach numbers. The effects of finite wing thickness on the missile characteristics, at zero angle of attack, increase with increasing Mach number. The effects of the pylon on the missile characteristics were to causeincreases in the rolling-moment variation with angle of attack and a negative displacement of the pitching-moment curves at zero angle of attack. The effects of skewing the missile in the lateral direction relative to and sideslipping the missile with the wing-fuselage-pylon combination were to cause additional increments in side force at zero angle of attack. For the missile yawing moments the effects of changes in skew or sideslip angles were qualitatively as would be expected from consideration of the isolated missile characteristics, although there existed differences in theyawing-moment magnitudes.

  5. Lift and wakes of flying snakes

    CERN Document Server

    Krishnan, Anush; Vlachos, Pavlos P; Barba, L A

    2013-01-01

    Flying snakes use a unique method of aerial locomotion: they jump from tree branches, flatten their bodies and undulate through the air to produce a glide. The shape of their body cross-section during the glide plays an important role in generating lift. This paper presents a computational investigation of the aerodynamics of the cross-sectional shape. We performed two-dimensional simulations of incompressible flow past the anatomically correct cross-section of the species Chrysopelea paradisi, showing that a significant enhancement in lift appears at an angle of attack of 35 degrees, above Reynolds numbers 2000. Previous experiments on physical models also obtained an increased lift, at the same angle of attack. The flow is inherently three-dimensional in physical experiments, due to fluid instabilities, and it is thus intriguing that the enhanced lift appears also in the two-dimensional simulations. The simulations point to the lift enhancement arising from the early separation of the boundary layer on the ...

  6. A Study on the Evaluation of Field Application of High-Fluidity Concrete Containing High Volume Fly Ash

    Directory of Open Access Journals (Sweden)

    Yun-Wang Choi

    2015-01-01

    Full Text Available In the recent concrete industry, high-fluidity concrete is being widely used for the pouring of dense reinforced concrete. Normally, in the case of high-fluidity concrete, it includes high binder contents, so it is necessary to replace part of the cement through admixtures such as fly ash to procure economic feasibility and durability. This study shows the mechanical properties and field applicability of high-fluidity concrete using mass of fly ash as alternative materials of cement. The high-fluidity concrete mixed with 50% fly ash was measured to manufacture concrete that applies low water/binder ratio to measure the mechanical characteristics as compressive strength and elastic modulus. Also, in order to evaluate the field applicability, high-fluidity concrete containing high volume fly ash was evaluated for fluidity, compressive strength, heat of hydration, and drying shrinkage of concrete.

  7. Multisensory systems integration for high-performance motor control in flies.

    Science.gov (United States)

    Frye, Mark A

    2010-06-01

    Engineered tracking systems 'fuse' data from disparate sensor platforms, such as radar and video, to synthesize information that is more reliable than any single input. The mammalian brain registers visual and auditory inputs to directionally localize an interesting environmental feature. For a fly, sensory perception is challenged by the extreme performance demands of high speed flight. Yet even a fruit fly can robustly track a fragmented odor plume through varying visual environments, outperforming any human engineered robot. Flies integrate disparate modalities, such as vision and olfaction, which are neither related by spatiotemporal spectra nor processed by registered neural tissue maps. Thus, the fly is motivating new conceptual frameworks for how low-level multisensory circuits and functional algorithms produce high-performance motor control.

  8. The Effect of Fly Ash Quality on the Engineering Properties of High-Performance Concrete

    Institute of Scientific and Technical Information of China (English)

    PENG Yuchu

    2012-01-01

    Abstract:Fly ash is the most inexpensive cementitious material,and its presence in concrete has increased in recent years because it has become more durable and environmentally friendly.This study examines densified mixture concrete and the effect of fly ash quality on high-flow,high-strength concrete.Tests show that when the same mixture achieves identical flow standards(slump > 250 mm;slump flow > 600 ram),the fly ash quality affects the nature of the concrete;additionally,and adding Class F fly ash to concrete(loss on ignition =6%)is more workable than adding Class C fly ash(loss on ignition =3%).However,adding fly ash with a high loss on ignition(9%)to concrete requires a substantial increase in the mixing water and a dose of superplasticizer to achieve the required workability.This reduces the quality of the concrete,which subsequently deteriorates its safety and durability.

  9. Properties of High Volume Fraction Fly Ash/Al Alloy Composites Produced by Infiltration Process

    Science.gov (United States)

    Kountouras, D. T.; Stergioudi, F.; Tsouknidas, A.; Vogiatzis, C. A.; Skolianos, S. M.

    2015-09-01

    In the present study, pressure infiltration is employed to synthesize aluminum alloy 7075-fly ash composites. The microstructure and chemical composition of the fly ash and the produced composite material was examined using optical and scanning electron microscopy, as well as x-ray diffraction. Several properties of the produced composite material were examined and evaluated including macro-hardness, wear, thermal expansion, and corrosion behavior. The wear characteristics of the composite, in the as-cast conditions, were studied by dry sliding wear tests. The corrosion behavior of composite material was evaluated by means of potentiodynamic corrosion experiments in a 3.5 wt.% NaCl solution. The composite specimens exhibit a homogeneous distribution of fly ash particles and present enhanced hardness values, compared to the matrix material. The high volume fraction of the fly ash reinforcement (>40%) in the composite material led to increased wear rates, attributed to the fragmentation of the fly ash particles. However, the presence of fly ash particles in the Al alloy matrix considerably decreased the coefficiency of thermal expansion, while resulting in an altered corrosion mechanism of the composite material with respect to the matrix alloy.

  10. Properties of High Volume Fly Ash Concrete Compensated by Metakaolin or Silica Fume

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The compressive strength and dynamic modulus of high volume fly ash concrete with incorporation of either metakaolin or silica fume were investigated. The water to cementitious materials ratio was kept at 0.4 for all mixtures. The use of high volume fly ash in concrete greatly reduces the strength and dynamic modulus during the first 28 days. The decreased properties during the short term of high volume fly ash concrete is effectively compensated by the incorporation of metakaolin or silica fume. The DTA results confirmed that metakaolin or silica fume increase the amount of the hydration products. An empirical relationship between dynamic modulus and compressive strength of concrete has been obtained. This relation provides a nondestructive evaluation for estimating the strength of concrete by use of the dynamic modulus.

  11. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    Directory of Open Access Journals (Sweden)

    Solikin Mochamad

    2017-01-01

    Full Text Available High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly Ash Concrete. The experiment and data analysis were prepared using minitab, a statistic software for design of experimental. The specimens were concrete cylinder with diameter of 15 cm and height of 30 cm, tested for its compressive strength at 56 days. The result of the research demonstrates that high volume fly ash concrete can produce comparable compressive strength which meets the strength of OPC design strength especially for high strength concrete. In addition, the best mix proportion to achieve the design strength is the combination of high strength concrete and 50% content of fly ash. Moreover, the use of spraying method for curing method of concrete on site is still recommended as it would not significantly reduce the compressive strength result.

  12. Concrete sustainability with very high amount of fly ash and slag

    Directory of Open Access Journals (Sweden)

    G. C. Isaia

    Full Text Available This article approaches concrete mix designs where cement is replaced by high amounts of slag and fly ash, with the purpose of turning it into a more sustainable construction material, that is, an authentic green concrete. Mix proportions with fly ash, ground-blasted furnace slag, and Portland cement were studied in binary and ternary mixtures for compressive strength levels of 40 MPa and 55 MPa. The replacement of cement with mineral additions ranged from 50% to 90% in mass. Mean decreases of 55% in the energy consumption, 78% in the CO² emissions, and 5% in the cost of the concrete m³, plus an increase of 40% in the mean index of durability were obtained, all ofwhich compared to the 40-MPa reference concrete. This study attests the technical, economical and environmental potentialities for theuse of concrete mixtures with until 90% of fly ash.

  13. High gradient magnetic filtration of cupric oxide and fly ash particles

    Energy Technology Data Exchange (ETDEWEB)

    Lua, A.C. [Nanyang Technological University (Singapore). School of Mechanical and Production Engineering

    1996-12-31

    High gradient magnetic filtration (HGMF) tests have been carried out on cupric oxide particles and power plant fly ash which were dispersed in air streams. An experimental test rig was set up to conduct these tests. Results showed that for cupric oxide particles, filtration efficiencies of up to 95% were obtained for submicron sizes with dust loadings of up to 0.36 time the matrix volume. For fly ash, filtration efficiencies of up to 65% were obtained for submicron particles. However, all particle sizes showed progressive deterioration in efficiencies with loading. At the end of the test, the matrix had collected 0.52 times its own mass of fly ash. 2 refs., 7 figs.

  14. Robert L. Gross, Well-Grounded in High-Flying Singapore

    Science.gov (United States)

    Goldman, Jay P.

    2005-01-01

    Could a North Dakota farm boy with a smallish frame, bookish appearance, understated speaking voice and aw-shucks humility possibly be a good fit to lead a powerhouse, cosmopolitan private school for American students living abroad, whose governing board consists mainly of high-flying corporate executives and well-heeled attorneys? The answer…

  15. Influence of Utilization of High-Volumes of Class F Fly Ash on the Abrasion Resistance of Concrete

    Directory of Open Access Journals (Sweden)

    William PRINCE

    2007-01-01

    Full Text Available Utilization of large volumes of fly ash in various concrete applications is a becoming a more general practice in an efforts towards using large quantities of fly ash. Around the world, Class C or Class F or both as available have been used in high volumes in cement-based materials. In India, majority of fly generated is of Class F type as per ASTM C 618. Yearly fly ash generation in India is approximately 95 million tonnes. Out of which around 15-20% is utilized in cement production and cement/concrete related activities. In order to increase its percentage utilization, an investigation was carried out to use it in concrete.In this paper, abrasion resistance of high volume fly ash (HVFA concretes made with 35, 45, 55, and 65% of cement replacement was evaluated in terms of its relation with compressive strength. Comparison was made between ordinary Portland cement and fly ash concrete. Test results indicated that abrasion resistance of concrete having cement replacement up to 35 percent was comparable to the normal concrete mix with out fly ash. Beyond 35% cement replacement, fly ash concretes exhibited slightly lower resistance to abrasion relative to non-fly ash concretes. Test results further indicated that abrasion resistance of concrete is closely related with compressive strength, and had a very good correlation between abrasion resistance and compressive strength (R2 value between 0.9018 and 0.9859 depending upon age.

  16. Hydrophobic high surface area zeolites derived from fly ash for oil spill remediation.

    Science.gov (United States)

    Sakthivel, Tamilselvan; Reid, David L; Goldstein, Ian; Hench, Larry; Seal, Sudipta

    2013-06-01

    Fly ash, a coal combustion byproduct with a predominantly aluminosilicate composition, is modified to develop an inexpensive sorbent for oil spill remediation. The as-produced fly ash is a hydrophilic material with poor sorption capacity. A simple two-step chemical modification process is designed to improve the oil sorption capacity. First, the fly ash was transformed to a zeolitic material via an alkali treatment, which increased the specific surface area up to 404 m(2) g(-1). Then, the material was surface functionalized to form a hydrophobic material with high contact angle up to 147° that floats on the surface of an oil-water mixture. The reported oil sorption capacities of X-type zeolite sorbent with different surface functionalization (propyl-, octyl-, octadecyl-trimethoxysilane and esterification) were estimated to 1.10, 1.02, 0.86, and 1.15 g g(-1), respectively. Oil sorption was about five times higher than the as-received fly ash (0.19 g g(-1)) and also had high buoyancy critical for economic cleanup of oil over water.

  17. Thermal treatment and utilization of Al-rich waste in high calcium fly ash geopolymeric materials

    Science.gov (United States)

    Chindaprasirt, Prinya; Rattanasak, Ubolluk; Vongvoradit, Pimdao; Jenjirapanya, Supichart

    2012-09-01

    The Al-rich waste with aluminium and hydrocarbon as the major contaminant is generated at the wastewater treatment unit of a polymer processing plant. In this research, the heat treatment of this Al-rich waste and its use to adjust the silica/alumina ratio of the high calcium fly ash geopolymer were studied. To recycle the raw Al-rich waste, the waste was dried at 110°C and calcined at 400 to 1000°C. Mineralogical analyses were conducted using X-ray diffraction (XRD) to study the phase change. The increase in calcination temperature to 600, 800, and 1000°C resulted in the phase transformation. The more active alumina phase of active γ-Al2O3 was obtained with the increase in calcination temperature. The calcined Al-rich waste was then used as an additive to the fly ash geopolymer by mixing with high calcium fly ash, water glass, 10 M sodium hydroxide (NaOH), and sand. Test results indicated that the calcined Al-rich waste could be used as an aluminium source to adjust the silica/alumina ratio and the strength of geopolymeric materials. The fly ash geopolymer mortar with 2.5wt% of the Al-rich waste calcined at 1000°C possessed the 7-d compressive strength of 34.2 MPa.

  18. A study of a three-dimensional self-propelled flying bird with flapping wings

    Science.gov (United States)

    Zhu, LinLin; Guan, Hui; Wu, ChuiJie

    2015-09-01

    In this paper, a study of a three-dimensional (3D) self-propelled bionic flying bird in a viscous flow is carried out. This bionic bird is propelled and lifted through flapping and rotating wings, and better flying can be achieved by adjusting the flapping and rotation motion of wings. In this study, we found that the bird can fly faster forward and upward with appropriate center of rotation and oscillation without more energy consumption and have perfect flight performance at a certain angle of attack by adjusting the center of oscillation. The study utilizes a 3D computational fluid dynamics package which constitutes combined immersed boundary method and the volume of fluid method. In addition, it includes adaptive multigrid finite volume method and control strategy of swimming and flying.

  19. Experimental wake survey behind Viking 1975 entry vehicle at angles of attack of 0 deg and 5 deg, Mach numbers from 1.60 to 3.95, and longitudinal stations from 1.0 to 8.39 body diameters

    Science.gov (United States)

    Brown, C. A., Jr.; Campbell, J. F.; Tudor, D. H.

    1971-01-01

    An investigation was conducted to obtain flow properties in the wake of the Viking '75 entry vehicle at Mach numbers from 1.60 to 3.95 and at angles of attack of 0 deg and 5 deg. The wake flow properties were calculated from total and static pressures measured with a pressure rake at longitudinal stations varying from 1.0 to 8.39 body diameters and lateral stations varying from -0.42 to 3.0 body diameters. These measurements showed a a consistent trend throughout the range of Mach numbers and longitudinal distances and an increase in dynamic pressure with increasing downstream position.

  20. Aerocapture Guidance and Performance at Mars for High-Mass Systems

    Science.gov (United States)

    Zumwalt, Carlie H.; Sostaric, Ronald r.; Westhelle, Carlos H.

    2009-01-01

    The Mars Entry, Descent, and Landing System Analysis (EDL-SA) project has been tasked with performing systems analysis to identify the optimal technologies required to land a 20-50 MT Exploration-class mission on Mars. It has been shown that it is not possible to safely land these large systems using heritage Mars EDL systems, or analogous Earth or Moon EDL systems. In 2007, NASA conducted a Mars Exploration Architecture Study which included an in depth review of the science motivations and engineering technology requirements for a human Mars mission campaign. This study resulted in an update to the Mars Design Reference Architecture (DRA 5.0). Among the primary findings and recommendations was the conclusion that landing of large payloads (greater than 1 MT) on the surface of Mars remains a key architectural challenge. Additionally, research and system studies of fundamental EDL technologies were highly recommended. The EDL-SA project identified the candidate technologies and assembled them into full capture and EDL sequences so that simulations could be developed to evaluate them. The chosen architectures combine the various technologies of interest in eight different ways. For aerocapture, only two scenarios were considered. The first is a rigid mid-L/D aeroshell (AS), which is represented in architectures 1, 4, 5, and 7. This scenario calls for a vehicle that flies at a 55-degree angle of attack, resulting in ballistic coefficient and L/D values of 490 kg/m 2 and 0.43, respectively. The second is a lifting hypersonic inflatable aerodynamic decelerator (HIAD), which is represented in architectures 2, 6, and 8. This scenario requires the vehicle to fly at a 22.2- degree angle of attack, which correlates to an L/D of 0.3 and was sized to provide a ballistic coefficient of 165 kg/m 2 . Architecture 3 is an all-propulsive sequence, and is not considered in this study.

  1. Mechanically activated fly ash as a high performance binder for civil engineering

    Science.gov (United States)

    Rieger, D.; Kullová, L.; Čekalová, M.; Novotný, P.; Pola, M.

    2017-01-01

    This study is aimed for investigation of fly ash binder with suitable properties for civil engineering needs. The fly ash from Czech brown coal power plant Prunerov II was used and mechanically activated to achieve suitable particle size for alkaline activation of hardening process. This process is driven by dissolution of aluminosilicate content of fly ash and by subsequent development of inorganic polymeric network called geopolymer. Hardening kinetics at 25 and 30 °C were measured by strain controlled small amplitude oscillatory rheometry with strain of 0.01 % and microstructure of hardened binder was evaluated by scanning electron microscopy. Strength development of hardened binder was investigated according to compressional and flexural strength for a period of 180 days. Our investigation finds out, that mechanically activated fly ash can be comparable to metakaolin geopolymers, according to setting time and mechanical parameters even at room temperature curing. Moreover, on the bases of long time strength development, achieved compressional strength of 134.5 after 180 days is comparable to performance of high grade Portland cement concretes.

  2. Self-healing of mechanically-loaded self consolidating concretes with high volumes of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa Sahmaran; Suleyman B. Keskin; Gozde Ozerkan; Ismail O. Yaman [University of Gaziantep, Gaziantep (Turkey). Department of Civil Engineering

    2008-11-15

    This article discusses the effects of self-healing on self consolidating concretes incorporating high volumes of fly ash (HVFA-SCC) when subjected to continuous water exposure. For this purpose, self consolidating concretes with fly ash replacement ratios of 0%, 35%, and 55% were prepared having a constant water-cementitious material ratio of 0.35. A uniaxial compression load was applied to generate microcracks in concrete where cylindrical specimens were pre-loaded up to 70% and 90% of the ultimate compressive load determined at 28 days. Later, the extent of damage was determined as percentage of loss in mechanical properties and percentage of increase in permeation properties. After pre-loading, concrete specimens were stored in water for a month and the mechanical and permeation properties are monitored at every two weeks. It was observed that HVFA-SCC mixtures initially lost 27% of their strength when pre-loaded up to 90% of their ultimate strength, and after 30 days of water curing that reduction was only 7%, indicating a substantial healing. On the other hand, for SCC specimens without fly ash that were pre-loaded to the same level, the loss in strength was initially 19%, and after a month of moist curing it was only 13%. Similar observations were also made on the permeation properties with greater effects. As the HVFA-SCCs studied have an important amount of unhydrated fly ash available in their microstructure, these observations are attributed to the self-healing of the pre-existing cracks, mainly by hydration of anhydrous fly ash particles on the crack surfaces.

  3. Flight orientation behaviors promote optimal migration trajectories in high-flying insects.

    Science.gov (United States)

    Chapman, Jason W; Nesbit, Rebecca L; Burgin, Laura E; Reynolds, Don R; Smith, Alan D; Middleton, Douglas R; Hill, Jane K

    2010-02-01

    Many insects undertake long-range seasonal migrations to exploit temporary breeding sites hundreds or thousands of kilometers apart, but the behavioral adaptations that facilitate these movements remain largely unknown. Using entomological radar, we showed that the ability to select seasonally favorable, high-altitude winds is widespread in large day- and night-flying migrants and that insects adopt optimal flight headings that partially correct for crosswind drift, thus maximizing distances traveled. Trajectory analyses show that these behaviors increase migration distances by 40% and decrease the degree of drift from seasonally optimal directions. These flight behaviors match the sophistication of those seen in migrant birds and help explain how high-flying insects migrate successfully between seasonal habitats.

  4. Experimental wake survey behind Viking 75 entry vehicle at angles of attack of 0 deg, 5 deg, and 10 deg, Mach numbers from 0.20 to 1.20, and longitudinal stations from 1.50 to 11.00 body diameters

    Science.gov (United States)

    Brown, C. A., Jr.; Campbell, J. F.

    1973-01-01

    An investigation was conducted to obtain flow properties in the wake of a preliminary configuration of the Viking '75 Entry Vehicle at Mach numbers from 0.20 to 1.20 and at angles of attack of 0 deg, 5 deg, and 10 deg. The wake flow properties were calculated from total and static pressures measured with a pressure rake at longitudinal stations varying from 1.50 to 11.00 body diameters, and are presented in tabulated and plotted form. The wake properties were essentially symmetrical about the X-axis at alpha = 0 deg and the profiles were shifted away from the X-axis at angles of attack. An unexpected reduction in wake property ratios occurred as the Mach number increased from 0.60 to 1.00; these ratios then increased as the Mach number increased to 1.20. The reduction was present for all the longitudinal stations of the tests and decreased with increased longitudinal distance.

  5. A Reflection on The Icarus Deception-How High Will You Fly Transla-tion Practice

    Institute of Scientific and Technical Information of China (English)

    WANG Ying

    2016-01-01

    This thesis is based on the author’s experience of English to Chinese translation practice of two parts of The Icarus De-ception—How High Will You Fly which is an economic motivation book by American best selling author Seth Godin published by Penguin Books Ltd Dec, 2012. The thesis is a reflection about the process of translation, from the perspectives of lexical, sen-tence structure, discourse and the understanding of the source text etc.

  6. Characterization of high-calcium fly ash and its influence on ettringite formation in portland cement pastes

    Science.gov (United States)

    Tishmack, Jody Kathleen

    High-calcium Class C fly ashes derived from Powder River Basin coal are currently used as supplementary cementing materials in portland cement concrete. These fly ashes tend to contain significant amounts of sulfur, calcium, and aluminum, thus they are potential sources of ettringite. Characterization of six high-calcium fly ashes originating from Powder River Basin coal have been carried out. The hydration products formed in pastes made from fly ash and water were investigated. The principal phases produced at room temperature were ettringite, monosulfate, and stratlingite. The relative amounts formed varied with the specific fly ash. Removal of the soluble crystalline sulfur bearing minerals indicated that approximately a third of the sulfur is located in the fly ash glass. Pore solution analyses indicated that sulfur concentrations increased at later ages. Three fly ashes were selected for further study based on their ability to form ettringite. Portland cement-fly ash pastes made with the selected fly ashes were investigated to evaluate ettringite and monosulfate formation. Each of the fly ashes were mixed with four different types of portland cements (Type I, I/II, II, and III) as well as three different Type I cements exhibiting a range of C3A and sulfate contents. The pastes had 25% or 35% fly ash by total weight of solids and a water:cement-fly ash ratio of 0.45. The samples were placed in a curing room (R.H. = 100, 23°C) and were then analyzed at various ages by x-ray diffraction (XRD) and differential scanning calorimetry (DSC) to determine the principal hydration products. The hydration products identified by XRD were portlandite, ettringite (an AFt phase), monosulfate, and generally smaller amounts of hemicarboaluminate and monocarboaluminate (all AFm phases). Although the amount of ettringite formed varied with the individual cement, only a modest correlation with cement sulfate content and no correlation with cement C3A content was observed. DSC

  7. Flying High.

    Science.gov (United States)

    Sherman, Lee; Paglin, Catherine; Jarrett, Denise; Kneidek, Tony

    1998-01-01

    Profiles 10 technology-based programs in Montana, Oregon, Washington, Alaska, and Idaho schools that use computers, the Internet, and multimedia to teach math, science, information skills, economics, English, history, and graphic design. Includes teacher comments on hardware, software, costs, the changing role of the teacher, Internet safety, and…

  8. Flying High

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The aviation sector is gearing up to handle the influx of visitors expected for the 2008 Olympics China’s civil aviation industry is preparing for the 2008 Olympics, with airports in cities that will host Olympic activities expanding and renovating their facilities to accommodate the influx of visitors to the Games. The Civil Aviation Administration of China (CAAC) has required such work at

  9. Flying High

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Eric Ransdell looks at the world through a softerfocus lens these days. The former war correspondent made his name interviewing machine-gun-toting rebels in Africa.Nowadays,the 44-year-old American is more likely to be found shooting corporate promotional videos in Shanghai.

  10. Resistance to Corrosion of Reinforcement of High Volume Fly Ash Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S. O.; Bae, S. H.; Lee, H. J. [Andong National University, Andong (Korea, Republic of); Lee, K. M. [Sungkyunkwan University, Suwon (Korea, Republic of); Jung, S. H. [Korea Confirmity Laboratories, Seoul (Korea, Republic of)

    2014-12-15

    Due to the increasing of interest about the eco-friendly concrete, it is increased to use concretes containing by-products of industry such as fly ash(FA), ground granulated blast furnace slag(GGBFS), silica fume(SF), and etc. Especially, these are well known for improving the resistances to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance against corrosion of reinforcement of high volume fly ash(HVFA) concrete which is replaced with high volume fly ash for cement volume. For this purpose, the concrete test specimens were made for various strength level and replacement ratio of FA, and then the compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91, and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that the compressive strength of HVFA concrete was decreased with increasing replacement ratio of FA but long-term resistances against reinforcement corrosion and chloride ion penetration of that were increased.

  11. Statistical evaluation of the mechanical properties of high-volume class F fly ash concretes

    KAUST Repository

    Yoon, Seyoon

    2014-03-01

    High-Volume Fly Ash (HVFA) concretes are seen by many as a feasible solution for sustainable, low embodied carbon construction. At the moment, fly ash is classified as a waste by-product, primarily of thermal power stations. In this paper the authors experimentally and statistically investigated the effects of mix-design factors on the mechanical properties of high-volume class F fly ash concretes. A total of 240 and 32 samples were produced and tested in the laboratory to measure compressive strength and Young\\'s modulus respectively. Applicability of the CEB-FIP (Comite Euro-international du Béton - Fédération Internationale de la Précontrainte) and ACI (American Concrete Institute) Building Model Code (Thomas, 2010; ACI Committee 209, 1982) [1,2] to the experimentally-derived mechanical property data for HVFA concretes was established. Furthermore, using multiple linear regression analysis, Mean Squared Residuals (MSRs) were obtained to determine whether a weight- or volume-based mix proportion is better to predict the mechanical properties of HVFA concrete. The significance levels of the design factors, which indicate how significantly the factors affect the HVFA concrete\\'s mechanical properties, were determined using analysis of variance (ANOVA) tests. The results show that a weight-based mix proportion is a slightly better predictor of mechanical properties than volume-based one. The significance level of fly ash substitution rate was higher than that of w/b ratio initially but reduced over time. © 2014 Elsevier Ltd. All rights reserved.

  12. Flexible Wing Kinematics of a Free-Flying Beetle (Rhinoceros Beetle Trypoxylus Dichotomus)

    Institute of Scientific and Technical Information of China (English)

    Tien Van Truong; Tuyen Quang Le; Doyoung Byun; Hoon Choel Park; Minjun Kim

    2012-01-01

    Detailed 3-Dimensional (3D) wing kinematics was experimentally presented in free flight of a beetle,Trypoxylus dichotomus,which has a pair of elytra (forewings) and flexible hind wings.The kinematic parameters such as the wing tip trajectory,angle of attack and camber deformation were obtained from a 3D reconstruction technique that involves the use of two synchronized high-speed cameras to digitize various points marked on the wings.Our data showed outstanding characteristics of deformation and flexibility of the beetle's hind wing compared with other measured insects,especially in the chordwise and spanwise directions during flapping motion.The hind wing produced 16% maximum positive camber deformation during the downstroke.It also experienced twisted shape showing large variation of the angle of attack from the root to the tip during the upstroke.

  13. Belite cement clinker from coal fly ash of high Ca content. Optimization of synthesis parameters

    Energy Technology Data Exchange (ETDEWEB)

    A. Guerrero; S. Goni; I. Campillo; A. Moragues [Instituto de Ciencias de la Construccion ' Eduardo Torroja' (CSIC), Madrid (Spain)

    2004-06-01

    The optimization of parameters of synthesis of belite cement clinker from Spanish coal fly ash of high Ca content is presented in this paper. The investigations were prompted by a need to reduce the CO{sub 2} emissions produced by the cement industry. Belite Ca{sub 2}SiO{sub 4} synthesis produces less CO{sub 2} than alite, the main component of Portland cement clinker. The synthesis process is based on the hydrothermal-calcination-route of the fly ash without extra additions. The hydrothermal treatment was carried out in demineralized water and a 1 M NaOH solution for 4 h at the temperatures of 100, 150, and 200{sup o} C. The precursors obtained during the hydrothermal treatment were heated at temperatures of 700, 800, 900, and 1000{sup o}C. The changes of fly ash composition after the different treatments were characterized by X-ray diffraction (XRD), FT infrared (FTIR) spectroscopy, surface area (BET-N{sub 2}), and thermal analyses. From the results obtained it was concluded that the optimum temperature of the hydrothermal treatment was 200{sup o}C, and the optimum temperature for obtaining the belite cement clinker was 800{sup o}C. 12 refs., 11 figs., 2 tabs.

  14. Orientation in high-flying migrant insects in relation to flows: mechanisms and strategies.

    Science.gov (United States)

    Reynolds, Andy M; Reynolds, Don R; Sane, Sanjay P; Hu, Gao; Chapman, Jason W

    2016-09-26

    High-flying insect migrants have been shown to display sophisticated flight orientations that can, for example, maximize distance travelled by exploiting tailwinds, and reduce drift from seasonally optimal directions. Here, we provide a comprehensive overview of the theoretical and empirical evidence for the mechanisms underlying the selection and maintenance of the observed flight headings, and the detection of wind direction and speed, for insects flying hundreds of metres above the ground. Different mechanisms may be used-visual perception of the apparent ground movement or mechanosensory cues maintained by intrinsic features of the wind-depending on circumstances (e.g. day or night migrations). In addition to putative turbulence-induced velocity, acceleration and temperature cues, we present a new mathematical analysis which shows that 'jerks' (the time-derivative of accelerations) can provide indicators of wind direction at altitude. The adaptive benefits of the different orientation strategies are briefly discussed, and we place these new findings for insects within a wider context by comparisons with the latest research on other flying and swimming organisms.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.

  15. Orientation in high-flying migrant insects in relation to flows: mechanisms and strategies

    Science.gov (United States)

    Reynolds, Andy M.; Reynolds, Don R.; Sane, Sanjay P.; Hu, Gao; Chapman, Jason W.

    2016-01-01

    High-flying insect migrants have been shown to display sophisticated flight orientations that can, for example, maximize distance travelled by exploiting tailwinds, and reduce drift from seasonally optimal directions. Here, we provide a comprehensive overview of the theoretical and empirical evidence for the mechanisms underlying the selection and maintenance of the observed flight headings, and the detection of wind direction and speed, for insects flying hundreds of metres above the ground. Different mechanisms may be used—visual perception of the apparent ground movement or mechanosensory cues maintained by intrinsic features of the wind—depending on circumstances (e.g. day or night migrations). In addition to putative turbulence-induced velocity, acceleration and temperature cues, we present a new mathematical analysis which shows that ‘jerks’ (the time-derivative of accelerations) can provide indicators of wind direction at altitude. The adaptive benefits of the different orientation strategies are briefly discussed, and we place these new findings for insects within a wider context by comparisons with the latest research on other flying and swimming organisms. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. PMID:27528782

  16. Changes in the timing of responses following spells of high speed flying

    Directory of Open Access Journals (Sweden)

    W.T.V. Adiseshiah

    1955-07-01

    Full Text Available One of the important signs of fatigue in pilots is prolongation of the time taken to respond to signals for action. Since promptness in action is essential in high speed flying, it was of interest to see whether any changes occur in the timing of response of IAF pilots after routing flying sorties. This study was carried out on a group of IAF jet fighter pilots stationed at Palam, New Delhi during the Summer months of 1954. The pilots were tested immediately before and after their flying exercises by measuring their response times to three arrangements of stimuli presented in rapid succession, so as to determine the time required for an immediate response, a discrimination and a choice. Analysis of results showed that there was slight prolongation in the post-flight values This difference was most marked after 'hard' stories. Of the various alternative explanations considered in order to account for this difference, 'transient, fatigue appears to be most plausible.

  17. Testing candidate genes for attention-deficit/hyperactivity disorder in fruit flies using a high throughput assay for complex behavior

    DEFF Research Database (Denmark)

    Rohde, Palle Duun; Madsen, Lisbeth Strøm; Arvidson, Sandra Marie Neumann

    2016-01-01

    Fruit flies are important model organisms for functional testing of candidate genes in multiple disciplines, including the study of human diseases. Here we use a high-throughput locomotor activity assay to test the response on activity behavior of gene disruption in Drosophila melanogaster. The aim...... was to investigate the impact of disruption of 14 candidate genes for human attention-deficit/hyperactivity disorder (ADHD) on fly behavior. By obtaining a range of correlated measures describing the space of variables for behavioral activity we show, that some mutants display similar phenotypic responses...... in fruit flies. Results provide additional support for the investigated genes being risk candidate genes for ADHD in humans....

  18. 三维机翼大迎角低速绕流及其涡控制的数值模拟%Numerical study on viscous flow and vortex control about finite span wings at high angles of attack

    Institute of Scientific and Technical Information of China (English)

    舒桃; 杨国伟; 陆夕云; 庄礼贤

    2002-01-01

    通过数值求解三维非定常可压缩雷诺平均Navier-Stokes方程,研究了三维机翼大迎角低速绕流及其带表面周期性吹吸气的流动控制,并探讨了非定常质量引射作为外激发手段对机翼气动力特性的影响.计算表明,在机翼前缘附近的小区域内施加周期性吹吸气进行流动控制,这类外激发手段对三维机翼的大迎角分离流动的控制是可行的,通过选择适当的控制参数,尤其是合适的周期性激振频率,可以有效地改善气动力特性.

  19. Sulfate and Chloride Resistance of High Fluidity Concrete including Fly Ash and GGBS for NPP

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Jea Myoung; Cho, Myung Sug [KEPCO Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    Fly ash mixed concrete has been used for NPP concrete structures in Korea in order to prevent aging and improve durability since the Shin.Kori no.1,2 in 2005. Concentrated efforts to develop technology for the streamlining of construction work and to affect labor savings have been conducted in construction. The application of high fluidity concrete for nuclear power plants has been the research subject with the aim of further rationalization of construction works. Since high fluidity concrete can have the characteristics of high density and high strength without compaction. However, high fluidity concrete can cause thermal cracking by heat of hydration. For this reason, the amount of pozzolan binder should be increased in high fluidity concrete for nuclear power plants. In this study, the resistance of high fluidity concrete on sulfate and chloride was compared with that of the concrete currently using for nuclear power plants

  20. Semi-analytical method for calculating aeroelastic effect of profiled rod flying at high velocity

    Directory of Open Access Journals (Sweden)

    Hui-jun Ning

    2015-03-01

    Full Text Available The key technique of a kinetic energy rod (KER warhead is to control the flight attitude of rods. The rods are usually designed to different shapes. A new conceptual KER named profiled rod which has large L/D ratio is described in this paper. The elastic dynamic equations of this profiled rod flying at high velocity after detonation are set up on the basis of Euler-Bernoulli beam, and the aeroelastic deformation of profiled rod is calculated by semi-analytical method for calculating the vibration characteristics of variable cross-section beam. In addition, the aeroelastic deformation of the undeformed profiled rod and the aeroelastic deformation of deformed profiled rod which is caused by the detonation of explosive are simulated by computational fluid dynamic and finite element method (CFD/FEM, respectively. A satisfactory agreement of these two methods is obtained by the comparison of two methods. The results show that the semi-analytical method for calculating the vibration characteristics of variable cross-section beam is applied to analyze the aeroelastic deformation of profiled rod flying at high velocity.

  1. Aerodynamic Characteristics of a Flying-Boat Hull Having a Length-Beam Ratio of 15, TED No. NACA 2206

    Science.gov (United States)

    Riebe, John M.; Naeseth, Rodger L.

    1951-01-01

    An investigation was made in the Langley 300 MPH 7- by 10-foot tunnel to determine the aerodynamic characteristics of a flying-boat hull of a length-beam ratio of 15 in the presence of a wing. The investigation was an extension of previous tests made on hulls of length-beam ratios of 6, 9, and 12; these hulls were designed to have approximately the same hydrodynamic performance with respect to spray and resistance characteristics. Comparison with the previous investigation at lower length-beam ratios indicated a reduction in minimum drag coefficients of 0.0006 (10 peroent)with fixed transition when the length-beam ratio was extended from 12 to 15. As with the hulls of lower length-beam ratio, the drag reduction with a length-beam ratio of 15 occurred throughout the range of angle of attack tested and the angle of attack for minimum drag was in the range from 2deg to 3deg. Increasing the length-beam ratio from 12 to 15 reduced the hull longitudinal instability by an mount corresponding to an aerodynamic-center shift of about 1/2 percent of the mean aerodynamic chord of the hypothetical flying boat. At an angle of attack of 2deg, the value of the variation of yawing-moment coefficient with angle of yaw for a length-beam ratio of 15 was 0.00144, which was 0.00007 larger than the value for a length-beam ratio of 12.

  2. High-carbon fly-ash as a binder for iron ore pellets

    Energy Technology Data Exchange (ETDEWEB)

    Kawatra, S.K.; Eisele, T.C.; Ripke, S.J.; Ramirez, G.

    1999-09-01

    The goal of this project was to convert currently unusable fly-ashes into a material that can be used as a binder for iron ore. Such a binder would also be useful for other high-volume markets, including foundry sand mold binders. Previously, the investigators used fly-ash in combination with calcium hydroxide as an additive while calcium chloride was added as a hardening accelerator. However, the addition of chloride salts have a detrimental effect because chlorine causes corrosion in processing equipment. Therefore, other potential hardening accelerators were investigated during this project. During production, dried iron-ore pellets are required to have crushing strength of at least 22.2 newtons (5 pounds force) per 12.7 mm (1/2 inch) diameter pellet. The pellets are then sintered at temperatures up to 1300 C and must not exhibit a significant degree of spalling or cracking. Pellets will therefore be tested to determine whether acceptable dry crushing strengths can be achieved.

  3. Compression Behavior of Confined Columns with High-Volume Fly Ash Concrete

    Directory of Open Access Journals (Sweden)

    Sung-Won Yoo

    2017-01-01

    Full Text Available The use of fly ash in ordinary concrete provides practical benefits to concrete structures, such as a gain in long-term strength, reduced hydration heat, improved resistance to chloride, and enhanced workability. However, few studies with high-volume fly ash (HVFA concrete have been conducted that focus on the structural applications such as a column. Thus, there is a need to promote field applications of HVFA concrete as a sustainable construction material. To this end, this study investigated the compressive behavior of reinforced concrete columns that contain HVFA with a 50 percent replacement rate. Six columns were fabricated for this study. The study variables were the HVFA replacement rate, tied steel ratio, and tie steel spacing. The computed ultimate strength by the American Concrete Institute (ACI code conservatively predicted the measured values, and, thus, the existing equation in the ACI code is feasible for confined RC columns that contain HVFA. In addition, an analysis model was calibrated based on the experimental results and is recommended for predicting the stress-strain relationship of confined reinforced concrete columns that contain HVFA.

  4. High Temperature Fission Chamber for He- and FLiBe-cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Zane W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, Dominic R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lance, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Roger G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warmack, Robert J. Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Harrison, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    We have evaluated candidate technologies for in-core fission chambers for high-temperature reactors to monitor power level via measurements of neutron flux from start-up through full power at up to 800°C. This research is important because there are no commercially available instruments capable of operating above 550 °C. Component materials and processes were investigated for fission chambers suitable for operation at 800 °C in reactors cooled by molten fluoride salt (FLiBe) or flowing He, with an emphasis placed on sensitivity (≥ 1 cps/nv), service lifetime (2 years at full power), and resistance to direct immersion in FLiBe. The latter gives the instrument the ability to survive accidents involving breach of a thimble. The device is envisioned to be a two-gap, three-electrode instrument constructed from concentric nickel-plated alumina cylinders and using a noble gas–nitrogen fill-gas. We report the results of measurements and calculations of the response of fill gasses, impurity migration in nickel alloy, brazing of the alumina insulator, and thermodynamic calculations.

  5. Properties of high calcium fly ash geopolymer pastes with Portland cement as an additive

    Science.gov (United States)

    Phoo-ngernkham, Tanakorn; Chindaprasirt, Prinya; Sata, Vanchai; Pangdaeng, Saengsuree; Sinsiri, Theerawat

    2013-02-01

    The effect of Portland cement (OPC) addition on the properties of high calcium fly ash geopolymer pastes was investigated in the paper. OPC partially replaced fly ash (FA) at the dosages of 0, 5%, 10%, and 15% by mass of binder. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions were used as the liquid portion in the mixture: NaOH 10 mol/L, Na2SiO3/NaOH with a mass ratio of 2.0, and alkaline liquid/binder (L/B) with a mass ratio of 0.6. The curing at 60°C for 24 h was used to accelerate the geopolymerization. The setting time of all fresh pastes, porosity, and compressive strength of the pastes at the stages of 1, 7, 28, and 90 d were tested. The elastic modulus and strain capacity of the pastes at the stage of 7 d were determined. It is revealed that the use of OPC as an additive to replace part of FA results in the decreases in the setting time, porosity, and strain capacity of the paste specimens, while the compressive strength and elastic modulus seem to increase.

  6. Potassium-based sorbents from fly ash for high-temperature CO2 capture.

    Science.gov (United States)

    Sanna, Aimaro; Maroto-Valer, M Mercedes

    2016-11-01

    Potassium-fly ash (K-FA) sorbents were investigated for high-temperature CO2 sorption. K-FAs were synthesised using coal fly ash as source of silica and aluminium. The synthesised materials were also mixed with Li2CO3 and Ca(OH)2 to evaluate their effect on CO2 capture. Temperature strongly affected the performance of the K-FA sorbents, resulting in a CO2 uptake of 1.45 mmol CO2/g sorbent for K-FA 1:1 at 700 °C. The CO2 sorption was enhanced by the presence of Li2CO3 (10 wt%), with the K-FA 1:1 capturing 2.38 mmol CO2/g sorbent at 700 °C in 5 min. This sorption was found to be similar to previously developed Li-Na-FA (2.54 mmol/g) and Li-FA (2.4 mmol/g) sorbents. The presence of 10 % Li2CO3 also accelerated sorption and desorption. The results suggest that the increased uptake of CO2 and faster reaction rates in presence of K-FA can be ascribed to the formation of K-Li eutectic phase, which favours the diffusion of potassium and CO2 in the material matrix. The cyclic experiments showed that the K-FA materials maintained stable CO2 uptake and reaction rates over 10 cycles.

  7. Impact of Micro Silca on the mechanical properties of high volume Fly Ash Concrete

    Science.gov (United States)

    Sripagadeesh, R.; Ramakrishnan, K.; Pugazhmani, G.; Ramasundram, S.; Muthu, D.; Venkatasubramanian, C.

    2017-07-01

    In the current situation, to overcome the difficulties of feasible construction, concrete made with various mixtures of Ordinary Portland Cement (OPC) and diverse mineral admixtures, is the wise choice for engineering construction. Mineral admixtures viz. Ground Granulated Blast Furnace Slag (GGBS), Meta kaolin (MK), Fly Ash (FA) and Silica Fume (SF) etc. are used as Supplementary Cementitious Materials (SCM) in binary and ternary blend cement system to enhance the mechanical and durability properties. Investigation on the effect of different replacement levels of OPC in M25 grade with FA + SF in ternary cement blend on the strength characteristics and beam behavior was studied. The OPC was partially replaced (by weight) with different combinations of SF (5%, 10%, 15%, 20% and 25%) and FA as 50% (High Volume Fly Ash - HVFA). The amount of FA addition is kept constant at 50% for all combinations. The compressive strength and tensile strength tests on cube and cylinder specimens, at 7 and 28 days were carried out. Based on the compressive strength results, optimum mix proportion was found out and flexural behaviour was studied for the optimum mix. It was found that all the mixes (FA + SF) showed improvement in compressive strength over that of the control mix and the mix with 50% FA + 10% SF has 20% increase over the control mix. The tensile strength was also increased over the control mix. Flexural behaviour also showed a significant improvement in the mix with FA and SF over the control mix.

  8. Flight style optimization in ski jumping on normal, large, and ski flying hills.

    Science.gov (United States)

    Jung, Alexander; Staat, Manfred; Müller, Wolfram

    2014-02-07

    In V-style ski jumping, aerodynamic forces are predominant performance factors and athletes have to solve difficult optimization problems in parts of a second in order to obtain their jump length maximum and to keep the flight stable. Here, a comprehensive set of wind tunnel data was used for optimization studies based on Pontryagin's minimum principle with both the angle of attack α and the body-ski angle β as controls. Various combinations of the constraints αmax and βmin(t) were analyzed in order to compare different optimization strategies. For the computer simulation studies, the Olympic hill profiles in Esto-Sadok, Russia (HS 106m, HS 140m), and in Harrachov, Czech Republic, host of the Ski Flying World Championships 2014 (HS 205m) were used. It is of high importance for ski jumping practice that various aerodynamic strategies, i.e. combinations of α- and β-time courses, can lead to similar jump lengths which enables athletes to win competitions using individual aerodynamic strategies. Optimization results also show that aerodynamic behavior has to be different at different hill sizes (HS). Optimized time courses of α and β using reduced drag and lift areas in order to mimic recent equipment regulations differed only in a negligible way. This indicates that optimization results presented here are not very sensitive to minor changes of the aerodynamic equipment features when similar jump length are obtained by using adequately higher in-run velocities. However, wind tunnel measurements with athletes including take-off and transition to stabilized flight, flight, and landing behavior would enable a more detailed understanding of individual flight style optimization.

  9. A brief on high-volume Class F fly ash as cement replacement – A guide for Civil Engineer

    OpenAIRE

    2015-01-01

    Disposal of fly ash (FA) resulting from the combustion of coal-fired electric power stations is one of the major environmental challenges. This challenge continues to increase with increasing the amount of FA and decreasing the capacity of landfill space. Therefore, studies have been carried out to re-use high-volumes of fly ash (HVFA) as cement replacement in building materials. This paper presents an overview of the previous studies carried out on the use of high volume Class F FA as a part...

  10. Observations of movement dynamics of flying insects using high resolution lidar

    DEFF Research Database (Denmark)

    Kirkeby, Carsten Thure; Wellenreuther, Maren; Brydegaard, Mikkel

    2016-01-01

    could distinguish three insect clusters based on morphology and found that two contained insects predominantly recorded above the field in the evening, whereas the third was formed by insects near the forest at around 21:30. Together our results demonstrate the capability of lidar for distinguishing......Insects are fundamental to ecosystem functioning and biodiversity, yet the study of insect movement, dispersal and activity patterns remains a challenge. Here we present results from a novel high resolution laser-radar (lidar) system for quantifying flying insect abundance recorded during one...... summer night in Sweden. We compare lidar recordings with data from a light trap deployed alongside the lidar. A total of 22808 insect were recorded, and the relative temporal quantities measured matched the quantities recorded with the light trap within a radius of 5 m. Lidar records showed that small...

  11. High performance fly ash mixed concrete in underground construction of Delhi metro

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, R.; Gupta, A.K.; Garg, R.; Gopalkrishnan, E. [DMRC, New Delhi (India)

    2003-07-01

    The paper describes the comprehensive concrete durability studies carried out for deciding the specifications for the MCIA contract for construction of 4 km of underground metro from Vishwa Vidyalaya station to Kashmere Gate station in India. The study involved adiabatic concrete temperature measurement tests to know the heat generation and temperature rising properties inside concrete mass. The paper describes the background for selection of fly ash as a part replacement up to 30% of cement in concrete including determination of specification, identification of source, collection and transportation by bulk carrier and transfer to storage silo at the concrete batching plant. Control of temperature of concrete during production and after placement requires detailed arrangements for cooling aggregates and water at batching plant and thermal insulation along with curing to the concrete placed at site. Fully tanked membrane waterproofing and special waterproofing details at construction joints also contribute towards achieving the high performance durable concrete structure. 3 refs., 6 figs., 11 tabs.

  12. Atmospheric studies using the high-resolution fly's eye xenon flasher array

    Science.gov (United States)

    Wiencke, Lawrence R.; Bird, D. J.; Chen, G. F.; Clay, R. W.; Dai, H. Y.; Dawson, B. R.; Huang, M. A.; Jui, C. C. H.; Kidd, M. J.; Kieda, D. B.; Ko, S.; Larsen, C. G.; Loh, Eugene C.; Smith, J. D.; Sokolsky, Pierre; Sommers, Paul; Tang, J. K.; Thomas, Stan B.; Wilkinson, C. R.; Yoshida, S.

    1996-11-01

    The High Resolution Fly's Eye (HiRes) cosmic ray detector at Dugway Utah, measures UV scintillation light from extensive air showers. The detection technique is calorimetric in that the amount of light produced is proportional to the energy of the primary particle. Primary particle energies range from 1017 to more than 1020 electron volts. The detector can measure air showers more than 30 km away, a distance of several atmospheric extinction lengths. Variations in the atmosphere can cause significant variations in the amount of light reaching the detector. Atmospheric monitoring is extremely important. This paper discusses a method, under development, that uses the HiRes detector to measure light scattered from pulsed collimated xenon flashbulb sources (Flashers). Discussion includes a description of the light sources and a preliminary data analysis to extract a measurement of atmospheric extinction length and scale height.

  13. Panofsky Prize Talk: The High Resolution Fly's Eye (HiRes) Experiment

    Science.gov (United States)

    Sokolsky, Pierre

    2008-04-01

    The High Resolution Fly's Eye (HiRes) experiment was the second-generation air fluorescence experiment proposed, built, and run by the HiRes collaboration, with members from the University of Utah, Columbia University, the University of Illinois, the University of New Mexico, Rutgers University, the University of Tokyo and the Los Alamos National Laboratory. I will report on the history of the project, the technical capabilities of the instrument built in the Utah desert and the physics results, culminating in the discovery of the Greisen-Zatsepin-Kuzmin cut-off. The HiRes experiment also pioneered many of the calibration and atmospheric monitoring techniques now in use by the Pierre Auger experiment and the Telescope Array experiment and I will describe a number of them in my talk.

  14. Influence of portland cement replacement in high calcium fly ash geopolymer paste

    Directory of Open Access Journals (Sweden)

    Tanakorn Phoo-ngernkham

    2014-03-01

    Full Text Available This article presents the influence of ordinary Portland cement (OPC replacement in high calcium fly ash (FA geopolymer paste. FA was used to replace OPC at the rate of 5, 10 and 15% by mass of binder. Sodium silicate (Na2SiO3 and 10 molar sodium hydroxide (NaOH solutions were used as the alkaline solution in the reaction. The Na2SiO3/NaOH ratio of 2.0 and the liquid/binder (L/B ratio of 0.60 were used in all mixtures. The results of increase OPC replacement, the setting time and compressive strain capacity decreased while the compressive strength and modulus of elasticity increased. The compressive strength and modulus of elasticity at 28 days of geopolymer pastes with 15% OPC replacement were 36.7 MPa and 13,300 MPa, respectively.

  15. Fresh properties of high-volume fly ash self consolidating concretes[ACI SP-235

    Energy Technology Data Exchange (ETDEWEB)

    Sahmaran, M.; Yaman, I.O.; Tokyay, M. [Middle East Technical Univ., (Turkey). Dept. of Civil Engineering

    2006-07-01

    Self-consolidating concrete (SCC) has excellent deformability, high resistance to segregation and can be filled into heavily reinforced molds without applying vibration. In addition to these technical advantages, SCC shortens construction time and guarantees higher durability and strength. Self consolidating characteristics are typically achieved using new generation superplasticizers to provide the required flowability. However, plasticizers reduce the viscosity of the SCC. The required cohesion can be achieved by a variety of methods, including the use of viscosity modifying admixtures, but all of the methods increase the cost of SCC. For that reason, mineral admixtures or inert materials such as limestone powder, natural pozzolans and fly ash (FA) are used to increase the viscosity and to reduce the cost of SCC. FA, a by-product of thermal power plants, has been shown to improve the mechanical properties and durability of concrete when used as a cement replacement material. This study evaluated the effects of adding high volumes of high-lime and low-lime FA on the fresh properties of SCCs. Properties of SCC in the fresh and hardened states with both high-lime and low-lime FA types were also examined. Following the mixing procedure, tests were performed on the fresh concrete to determine slump flow time to reach a concrete 500 mm spread circle and diameter, V-funnel flow time, L-box test, GTM sieve stability, setting times, and rheological parameters, relative yield stress and plastic viscosity. During the slump flow test, segregation and bleeding were also visually checked. The results of density and compressive strength of hardened SCC mixtures at 28 and 90 days were also presented. It was concluded that the addition of low-lime FA at high volumes reduced the water requirement of the SCC mixture. Slump flow time, V-funnel flow time and the relative plastic viscosity were related to the viscosity of concrete. The segregation resistance, L-box height ratio and

  16. Aerodynamic performance enhancement of a flying wing using nanosecond pulsed DBD plasma actuator

    Directory of Open Access Journals (Sweden)

    Han Menghu

    2015-04-01

    Full Text Available Experimental investigation of aerodynamic control on a 35° swept flying wing by means of nanosecond dielectric barrier discharge (NS-DBD plasma was carried out at subsonic flow speed of 20–40 m/s, corresponding to Reynolds number of 3.1 × 105–6.2 × 105. In control condition, the plasma actuator was installed symmetrically on the leading edge of the wing. Lift coefficient, drag coefficient, lift-to-drag ratio and pitching moment coefficient were tested with and without control for a range of angles of attack. The tested results indicate that an increase of 14.5% in maximum lift coefficient, a decrease of 34.2% in drag coefficient, an increase of 22.4% in maximum lift-to-drag ratio and an increase of 2° at stall angle of attack could be achieved compared with the baseline case. The effects of pulsed frequency, amplitude and chord Reynolds number were also investigated. And the results revealed that control efficiency demonstrated strong dependence on pulsed frequency. Moreover, the results of pitching moment coefficient indicated that the breakdown of leading edge vortices could be delayed by plasma actuator at low pulsed frequencies.

  17. Differential pressure measurement using a free-flying insect-like ornithopter with an MEMS sensor

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hidetoshi; Aoyama, Yuichiro; Ohsawa, Kazuharu; Iwase, Eiji; Matsumoto, Kiyoshi; Shimoyama, Isao [Department of Mechano-Informatics, Graduate School of Information Science and Technology, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Tanaka, Hiroto, E-mail: isao@leopard.t.u-tokyo.ac.j [School of Engineering and Applied Sciences, Harvard University, 60 Oxford Street, Cambridge, MA 02138 (United States)

    2010-09-15

    This paper presents direct measurements of the aerodynamic forces on the wing of a free-flying, insect-like ornithopter that was modeled on a hawk moth (Manduca sexta). A micro differential pressure sensor was fabricated with micro electro mechanical systems (MEMS) technology and attached to the wing of the ornithopter. The sensor chip was less than 0.1% of the wing area. The mass of the sensor chip was 2.0 mg, which was less than 1% of the wing mass. Thus, the sensor was both small and light in comparison with the wing, resulting in a measurement system that had a minimal impact on the aerodynamics of the wing. With this sensor, the 'pressure coefficient' of the ornithopter wing was measured during both steady airflow and actual free flight. The maximum pressure coefficient observed for steady airflow conditions was 1.4 at an angle of attack of 30{sup 0}. In flapping flight, the coefficient was around 2.0 for angles of attack that ranged from 25{sup 0} to 40{sup 0}. Therefore, a larger aerodynamic force was generated during the downstroke in free flight compared to steady airflow conditions.

  18. Differential pressure measurement using a free-flying insect-like ornithopter with an MEMS sensor.

    Science.gov (United States)

    Takahashi, Hidetoshi; Aoyama, Yuichiro; Ohsawa, Kazuharu; Tanaka, Hiroto; Iwase, Eiji; Matsumoto, Kiyoshi; Shimoyama, Isao

    2010-09-01

    This paper presents direct measurements of the aerodynamic forces on the wing of a free-flying, insect-like ornithopter that was modeled on a hawk moth (Manduca sexta). A micro differential pressure sensor was fabricated with micro electro mechanical systems (MEMS) technology and attached to the wing of the ornithopter. The sensor chip was less than 0.1% of the wing area. The mass of the sensor chip was 2.0 mg, which was less than 1% of the wing mass. Thus, the sensor was both small and light in comparison with the wing, resulting in a measurement system that had a minimal impact on the aerodynamics of the wing. With this sensor, the 'pressure coefficient' of the ornithopter wing was measured during both steady airflow and actual free flight. The maximum pressure coefficient observed for steady airflow conditions was 1.4 at an angle of attack of 30 degrees . In flapping flight, the coefficient was around 2.0 for angles of attack that ranged from 25 degrees to 40 degrees . Therefore, a larger aerodynamic force was generated during the downstroke in free flight compared to steady airflow conditions.

  19. Wind selection and drift compensation optimize migratory pathways in a high-flying moth.

    Science.gov (United States)

    Chapman, Jason W; Reynolds, Don R; Mouritsen, Henrik; Hill, Jane K; Riley, Joe R; Sivell, Duncan; Smith, Alan D; Woiwod, Ian P

    2008-04-01

    Numerous insect species undertake regular seasonal migrations in order to exploit temporary breeding habitats [1]. These migrations are often achieved by high-altitude windborne movement at night [2-6], facilitating rapid long-distance transport, but seemingly at the cost of frequent displacement in highly disadvantageous directions (the so-called "pied piper" phenomenon [7]). This has lead to uncertainty about the mechanisms migrant insects use to control their migratory directions [8, 9]. Here we show that, far from being at the mercy of the wind, nocturnal moths have unexpectedly complex behavioral mechanisms that guide their migratory flight paths in seasonally-favorable directions. Using entomological radar, we demonstrate that free-flying individuals of the migratory noctuid moth Autographa gamma actively select fast, high-altitude airstreams moving in a direction that is highly beneficial for their autumn migration. They also exhibit common orientation close to the downwind direction, thus maximizing the rectilinear distance traveled. Most unexpectedly, we find that when winds are not closely aligned with the moth's preferred heading (toward the SSW), they compensate for cross-wind drift, thus increasing the probability of reaching their overwintering range. We conclude that nocturnally migrating moths use a compass and an inherited preferred direction to optimize their migratory track.

  20. Transport and mechanical properties of self consolidating concrete with high volume fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa Sahmaran; Ismail O. Yaman; Mustafa Tokyay [Gaziantep University, Gaziantep (Turkey). Department of Civil Engineering

    2009-02-15

    This paper presents the transport and mechanical properties of self consolidating concrete that contain high percentages of low-lime and high-lime fly ash (FA). Self consolidating concretes (SCC) containing five different contents of high-lime FA and low-lime FA as a replacement of cement (30, 40, 50, 60 and 70 by weight of total cementitious material) are examined. For comparison, a control SCC mixture without any FA was also produced. The fresh properties of the SCCs were observed through, slump flow time and diameter, V-funnel flow time, L-box height ratio, and segregation ratio. The hardened properties included the compressive strength, split tensile strength, drying shrinkage and transport properties (absorption, sorptivity and rapid chloride permeability tests) up to 365 days. Test results confirm that it is possible to produce SCC with a 70% of cement replacement by both types of FA. The use of high volumes of FA in SCC not only improved the workability and transport properties but also made it possible to produce concretes between 33 and 40 MPa compressive strength at 28 days, which exceeds the nominal compressive strength for normal concrete (30 MPa).

  1. High stenghth concrete with high cement substitution by adding fly ash, CaCO3, silica sand, and superplasticizer

    Science.gov (United States)

    Wicaksono, Muchammad Ridho Sigit; Qoly, Amelia; Hidayah, Annisaul; Pangestuti, Endah Kanti

    2017-03-01

    Concrete is a mixture of cement, fine aggregate, coarse aggregate and water with or without additives. Concrete can be made with substitution of cement with materials like Fly Ash, CaCO3 and silica sand that can increase the binding on pasta and also increase the compressive strength of concrete. The Superplasticizer on a mixture is used to reduce the high water content, improve concrete durability, low permeability concrete by making it more resilient, and improve the quality of concrete. The combination between Fly Ash (30% of cement required), CaCO3 (10% of cement required) and silica sand (5% of cement required) with added MasterGlenium ACE 8595 as much as 1,2% from total cement will produces compressive strength of up to 1080 kN/cm2 or 73,34 Mpa when the concrete is aged at 28 day. By using this technique and innovation, it proves that the cost reduction is calculated at 27%, which is much more efficient. While the strength of the concrete is increased at 5% compared with normal mixture.

  2. Design of a high altitude long endurance flying-wing solar-powered unmanned air vehicle

    Science.gov (United States)

    Alsahlani, A. A.; Johnston, L. J.; Atcliffe, P. A.

    2017-06-01

    The low-Reynolds number environment of high-altitude §ight places severe demands on the aerodynamic design and stability and control of a high altitude, long endurance (HALE) unmanned air vehicle (UAV). The aerodynamic efficiency of a §ying-wing configuration makes it an attractive design option for such an application and is investigated in the present work. The proposed configuration has a high-aspect ratio, swept-wing planform, the wing sweep being necessary to provide an adequate moment arm for outboard longitudinal and lateral control surfaces. A design optimization framework is developed under a MATLAB environment, combining aerodynamic, structural, and stability analysis. Low-order analysis tools are employed to facilitate efficient computations, which is important when there are multiple optimization loops for the various engineering analyses. In particular, a vortex-lattice method is used to compute the wing planform aerodynamics, coupled to a twodimensional (2D) panel method to derive aerofoil sectional characteristics. Integral boundary-layer methods are coupled to the panel method in order to predict §ow separation boundaries during the design iterations. A quasi-analytical method is adapted for application to flyingwing con¦gurations to predict the wing weight and a linear finite-beam element approach is used for structural analysis of the wing-box. Stability is a particular concern in the low-density environment of high-altitude flight for flying-wing aircraft and so provision of adequate directional stability and control power forms part of the optimization process. At present, a modified Genetic Algorithm is used in all of the optimization loops. Each of the low-order engineering analysis tools is validated using higher-order methods to provide con¦dence in the use of these computationally-efficient tools in the present design-optimization framework. This paper includes the results of employing the present optimization tools in the design of a

  3. Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

    Energy Technology Data Exchange (ETDEWEB)

    Lopareva-Pohu, Alena [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Pourrut, Bertrand; Waterlot, Christophe [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Garcon, Guillaume [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Bidar, Geraldine; Pruvot, Christelle [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Shirali, Pirouz [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Douay, Francis, E-mail: f.douay@isa-lille.fr [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France)

    2011-01-01

    Sustainable management of large surface areas contaminated with trace elements is a real challenge, since currently applied remediation techniques are too expensive for these areas. Aided phytostabilisation appears to be a cost efficient technique to reduce metal mobility in contaminated soils and contaminated particle spread. In this context, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated with trace elements. The influence of afforestation and fly ash amendments to reduce metal mobility was investigated. Before being planted with a tree mix, the study site was divided into three plots: a reference plot with no amendment, the second amended with silico-aluminous fly ash and the third with sulfo-calcic fly ash. After eight years, some soil physico-chemical parameters, including cadmium (Cd), lead (Pb) and zinc (Zn) extractability were modified. In particular, pH decreased on the whole site while organic carbon content increased. The alteration of these parameters influencing trace element mobility is explained by afforestation. Over time, concentrations of CaCl{sub 2}-extractable metals increased and were correlated with the soil pH decrease. In the amended soils, extractable Cd, Pb and Zn concentrations were lower than in the reference soil. The results indicated that the two fly ashes buffered natural soil acidification due to vegetation development and limited trace element mobility and thus could limit their bioavailability. For long-term phytostabilisation, special attention should be focused on the soil pH, metal mobility and phytoavailability analysis. - Research Highlights: {yields} Afforestation leads to soil pH decrease and organic carbon content increase. {yields} Fly ashes buffered natural soil acidification. {yields} Fly ashes limited metal mobility.

  4. Evaluation of the Chemical and Mechanical Properties of Hardening High-Calcium Fly Ash Blended Concrete

    Directory of Open Access Journals (Sweden)

    Wei-Jie Fan

    2015-09-01

    Full Text Available High-calcium fly ash (FH is the combustion residue from electric power plants burning lignite or sub-bituminous coal. As a mineral admixture, FH can be used to produce high-strength concrete and high-performance concrete. The development of chemical and mechanical properties is a crucial factor for appropriately using FH in the concrete industry. To achieve sustainable development in the concrete industry, this paper presents a theoretical model to systematically evaluate the property developments of FH blended concrete. The proposed model analyzes the cement hydration, the reaction of free CaO in FH, and the reaction of phases in FH other than free CaO. The mutual interactions among cement hydration, the reaction of free CaO in FH, and the reaction of other phases in FH are also considered through the calcium hydroxide contents and the capillary water contents. Using the hydration degree of cement, the reaction degree of free CaO in FH, and the reaction degree of other phases in FH, the proposed model evaluates the calcium hydroxide contents, the reaction degree of FH, chemically bound water, porosity, and the compressive strength of hardening concrete with different water to binder ratios and FH replacement ratios. The evaluated results are compared to experimental results, and good consistencies are found.

  5. Evaluation of the Chemical and Mechanical Properties of Hardening High-Calcium Fly Ash Blended Concrete.

    Science.gov (United States)

    Fan, Wei-Jie; Wang, Xiao-Yong; Park, Ki-Bong

    2015-09-07

    High-calcium fly ash (FH) is the combustion residue from electric power plants burning lignite or sub-bituminous coal. As a mineral admixture, FH can be used to produce high-strength concrete and high-performance concrete. The development of chemical and mechanical properties is a crucial factor for appropriately using FH in the concrete industry. To achieve sustainable development in the concrete industry, this paper presents a theoretical model to systematically evaluate the property developments of FH blended concrete. The proposed model analyzes the cement hydration, the reaction of free CaO in FH, and the reaction of phases in FH other than free CaO. The mutual interactions among cement hydration, the reaction of free CaO in FH, and the reaction of other phases in FH are also considered through the calcium hydroxide contents and the capillary water contents. Using the hydration degree of cement, the reaction degree of free CaO in FH, and the reaction degree of other phases in FH, the proposed model evaluates the calcium hydroxide contents, the reaction degree of FH, chemically bound water, porosity, and the compressive strength of hardening concrete with different water to binder ratios and FH replacement ratios. The evaluated results are compared to experimental results, and good consistencies are found.

  6. Fly ash carbon passivation

    Science.gov (United States)

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  7. Impact Properties of Engineered Cementitious Composites with High Volume Fly Ash Using SHPB Test

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhitao; YANG Yingzi; YAO Yan

    2012-01-01

    The split Hopkinson pressure bar (SHPB) testing with diameter 40 mm was used to investigate the dynamic mechanical properties of engineered cementitious composites (ECCs) with different fly ash content.The basic properties including deformation,energy absorption capacity,strain-stress relationship and failure patterns were discussed.The ECCs showed strain-rate dependency and kept better plastic flow during impact process compared with reactive powder concrete (RPC) and concrete,but the critical compressive strength was lower than that of R-PC and concrete.The bridging effect of PVA fiber and addition of fly ash can significantly improve the deformation and energy absorption capacities of ECCs.With the increase of fly ash content in ECCs,the static and dynamic compressive strength lowered and the dynamic increase factor enhanced,Therefore,to meet different engineering needs,the content of fly ash can be an important index to control the static and dynamic mechanical properties of ECCs.

  8. Applying GIS and high performance agent-based simulation for managing an Old World Screwworm fly invasion of Australia.

    Science.gov (United States)

    Welch, M C; Kwan, P W; Sajeev, A S M

    2014-10-01

    Agent-based modelling has proven to be a promising approach for developing rich simulations for complex phenomena that provide decision support functions across a broad range of areas including biological, social and agricultural sciences. This paper demonstrates how high performance computing technologies, namely General-Purpose Computing on Graphics Processing Units (GPGPU), and commercial Geographic Information Systems (GIS) can be applied to develop a national scale, agent-based simulation of an incursion of Old World Screwworm fly (OWS fly) into the Australian mainland. The development of this simulation model leverages the combination of massively data-parallel processing capabilities supported by NVidia's Compute Unified Device Architecture (CUDA) and the advanced spatial visualisation capabilities of GIS. These technologies have enabled the implementation of an individual-based, stochastic lifecycle and dispersal algorithm for the OWS fly invasion. The simulation model draws upon a wide range of biological data as input to stochastically determine the reproduction and survival of the OWS fly through the different stages of its lifecycle and dispersal of gravid females. Through this model, a highly efficient computational platform has been developed for studying the effectiveness of control and mitigation strategies and their associated economic impact on livestock industries can be materialised.

  9. Dynamic Stress-Strain Behaviour of Steel Fiber Reinforced High-Performance Concrete with Fly Ash

    Directory of Open Access Journals (Sweden)

    Tan Chien Yet

    2012-01-01

    Full Text Available The addition of steel fibers into concrete mix can significantly improve the engineering properties of concrete. The mechanical behaviors of steel fiber reinforced high-performance concrete with fly ash (SFRHPFAC are studied in this paper through both static compression test and dynamic impact test. Cylindrical and cube specimens with three volume fractions of end-hooked steel fibers with volume fraction of 0.5%, 1.0%, and 1.5% (39.25, 78.50, and 117.75 kg/m3 and aspect ratio of 64 are used. These specimens are then tested for static compression and for dynamic impact by split Hopkinson pressure bar (SHPB at strain rate of 30–60 s−1. The results reveal that the failure mode of concrete considerably changes from brittle to ductile with the addition of steel fibers. The plain concrete may fail under low-strain-rate single impact whereas the fibrous concrete can resist impact at high strain rate loading. It is shown that strain rate has great influence on concrete strength. Besides, toughness energy is proportional to the fiber content in both static and dynamic compressions.

  10. Flying Things

    DEFF Research Database (Denmark)

    Cermak, Daniel

    2016-01-01

    Daniel Cermak-Sassenrath. Flying Things. Installation. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016.......Daniel Cermak-Sassenrath. Flying Things. Installation. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016....

  11. Synthesis of Mullite from High-alumina Fly Ash: a Case from the Jungar Power Plant in Inner Mongolia, Northern China

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiangfeng; SHAO Longyi; LU Jing

    2008-01-01

    In this paper, an experimental study was conducted in order to test the feasibility of sintering mullite directly from the high-alumina fly ash, without adding any extra material. The results show that the mullite contents in most sintered samples are over 70%. The samples sintered from the beneficiated fly ash have a higher content of mullite than those from the as-received fly ash under the same synthetic conditions. To obtain an equal amount of mullite, a higher sintering temperature is needed for the beneficiated fly ash than for the as-received fly ash. Considering the physical properties of sintered mullite, the favorable sintering temperature is 1400 ℃ for the as-received fly ash and 1500 ℃ for the beneficiated fly ash. A higher sintering temperature and a shorter holding time are profitable to sintering mullite. The orthogonal test confirmed that the dominant factor affecting mullite synthesis is sintering temperature, and that the most profitable matching conditions are 200 MPa-1500 ℃-3 h for the as-received fly ash and 200 MPa-1500 ℃-4 h for the beneficiated fly ash.

  12. Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

    Energy Technology Data Exchange (ETDEWEB)

    Pourrut, Bertrand [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Lopareva-Pohu, Alena [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); Pruvot, Christelle [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Garcon, Guillaume; Verdin, Anthony [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); Waterlot, Christophe; Bidar, Geraldine [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Shirali, Pirouz [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); and others

    2011-10-01

    Aided phytostabilisation is a cost-efficient technique to manage metal-contaminated areas, particularly in the presence of extensive pollution. Plant establishment and survival in highly metal-contaminated soils are crucial for phytostabilisation success, as metal toxicity for plants is widely reported. A relevant phytostabilisation solution must limit metal transfer through the food chain. Therefore, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated by cadmium, lead, and zinc. The influence of afforestation and fly ash amendments on reducing metal phytoavailability was investigated as were their effects on plant development. Before being planted with a tree mix, the site was divided into three plots: a reference plot with no amendment, a plot amended with silico-aluminous fly ash and one with sulfo-calcic fly ash. Unlike Salix alba and Quercus robur, Alnus glutinosa, Acer pseudoplatanus and Robinia pseudoacacia grew well on the site and accumulated, overall, quite low concentrations of metals in their leaves and young twigs. This suggests that these three species have an excluder phenotype for Cd, Zn and Pb. After 8 years, metal availability to A. glutinosa, A. pseudoplatanus and R. pseudoacacia, and translocation to their above-ground parts, strongly decreased in fly ash-amended soils. Such decreases fit well together with the depletion of CaCl{sub 2}-extractable metals in amended soils. Although both fly ashes were effective to decrease Cd, Pb and Zn concentrations in above-ground parts of trees, the sulfo-calcic ash was more efficient.

  13. Observations of movement dynamics of flying insects using high resolution lidar.

    Science.gov (United States)

    Kirkeby, Carsten; Wellenreuther, Maren; Brydegaard, Mikkel

    2016-07-04

    Insects are fundamental to ecosystem functioning and biodiversity, yet the study of insect movement, dispersal and activity patterns remains a challenge. Here we present results from a novel high resolution laser-radar (lidar) system for quantifying flying insect abundance recorded during one summer night in Sweden. We compare lidar recordings with data from a light trap deployed alongside the lidar. A total of 22808 insect were recorded, and the relative temporal quantities measured matched the quantities recorded with the light trap within a radius of 5 m. Lidar records showed that small insects (wing size 2.5 mm(2) in cross-section) were most abundant near the lidar beam before 22:00 and then moved towards the light trap between 22:00 and 23:30. We could distinguish three insect clusters based on morphology and found that two contained insects predominantly recorded above the field in the evening, whereas the third was formed by insects near the forest at around 21:30. Together our results demonstrate the capability of lidar for distinguishing different types of insect during flight and quantifying their movements.

  14. Cellular lightweight concrete containing high-calcium fly ash and natural zeolite

    Science.gov (United States)

    Jitchaiyaphum, Khamphee; Sinsiri, Theerawat; Jaturapitakkul, Chai; Chindaprasirt, Prinya

    2013-05-01

    Cellular lightweight concrete (CLC) with the controlled density of approximately 800 kg/m3 was made from a preformed foam, Type-I Portland cement (OPC), fly ash (FA), or natural zeolite (NZ), and its compressive strength, setting time, water absorption, and microstructure of were tested. High-calcium FA and NZ with the median particle sizes of 14.52 and 7.72 μm, respectively, were used to partially replace OPC at 0, 10wt%, 20wt%, and 30wt% of the binder (OPC and pozzolan admixture). A water-to-binder mass ratio (W/B) of 0.5 was used for all mixes. The testing results indicated that CLC containing 10wt% NZ had the highest compressive strength. The replacement of OPC with NZ decreased the total porosity and air void size but increased the capillary porosity of the CLC. The incorporation of a suitable amount of NZ decreased the setting time, total porosity, and pore size of the paste compared with the findings with the same amount of FA. The total porosity and cumulative pore volume decreased, whereas the gel and capillary pores increased as a result of adding both pozzolans at all replacement levels. The water absorption increased as the capillary porosity increased; this effect depended on the volume of air entrained and the type or amount of pozzolan.

  15. Observations of movement dynamics of flying insects using high resolution lidar

    Science.gov (United States)

    Kirkeby, Carsten; Wellenreuther, Maren; Brydegaard, Mikkel

    2016-07-01

    Insects are fundamental to ecosystem functioning and biodiversity, yet the study of insect movement, dispersal and activity patterns remains a challenge. Here we present results from a novel high resolution laser-radar (lidar) system for quantifying flying insect abundance recorded during one summer night in Sweden. We compare lidar recordings with data from a light trap deployed alongside the lidar. A total of 22808 insect were recorded, and the relative temporal quantities measured matched the quantities recorded with the light trap within a radius of 5 m. Lidar records showed that small insects (wing size insects (wing size >2.5 mm2 in cross-section) were most abundant near the lidar beam before 22:00 and then moved towards the light trap between 22:00 and 23:30. We could distinguish three insect clusters based on morphology and found that two contained insects predominantly recorded above the field in the evening, whereas the third was formed by insects near the forest at around 21:30. Together our results demonstrate the capability of lidar for distinguishing different types of insect during flight and quantifying their movements.

  16. DSP-based control of a high frequency three cell flying capacitor inverter

    Science.gov (United States)

    Flores-Fuentes, A. A.; Rossano-Díaz, I. O.; Peña-Eguiluz, R.; López-Callejas, R.; Mercado-Cabrera, A.; de la Piedad-Beneitez, A.; Barocio, S. R.; Valencia, R.

    2010-03-01

    The design, instrumentation and early operation results of a digitally controlled voltage source inverter (VSI) are described. This inverter has been structured from a three cell flying capacitor inverter (TCFCI). Two different inverter control modes - open-loop and closed-loop - are applied by a digital system based on a Texas Instrument TMS320C6713 digital signal processor (DSP) board. The VSI is able to generate AC voltage signals up to 120 V amplitudes at a maximal 6 A current, from ∼9 kHz to ∼60 kHz in ∼900 Hz steps in both controls by varying the signal period through the square-wave command strategy. The multi-cell structure of the inverter provides an output frequency nearly three times that of the TCFCI semiconductor commutation. The power output of the TCFCI can drive a high frequency step-up transformer which, in turn, is associated with a cylindrical reactor where dielectric barrier discharges (DBD) are conducted.

  17. R&D of Novel Materials for Animal Litters Using High Carbon Fly Ash Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Boxley, Chett J. [Ceramatec, Inc., Salt Lake City, UT (United States); Kadota, Rod [Ceramatec, Inc., Salt Lake City, UT (United States)

    2012-10-29

    This research program performed by Ceramatec may significantly increase the beneficial utilization of fly ash, and improve the overall performance of high quality animal litter products. Ceramatec has developed a novel high surface area material, which is capable of ammonia adsorption. High surface area zeolites when combined with agglomerated fly ash can significantly reduce the use of naturally mined materials (i.e. clay bentonite) for animal litter manufacture. This not only preserves natural resources and the natural environment, but it also will reduce CO2 emissions, via the reduced need for heavy mining equipment. This novel animal litter is made with over 85% of recycled materials, thus preventing their disposition to landfills. The novel litter material is similar to traditional clay-like litters, and it is clumpable and has superior odor control properties.

  18. High-resolution flying-PIV with optical fiber laser delivery

    Science.gov (United States)

    Weichselbaum, Noah A.; André, Matthieu A.; Rahimi-Abkenar, Morteza; Manzari, Majid T.; Bardet, Philippe M.

    2016-05-01

    Implementation of non-intrusive optical measurement techniques, such as particle image velocimetry (PIV), in harsh environments requires specialized techniques for introducing controlled laser sheets to the region of interest. Large earthquake shake tables are a particularly challenging environment. Lasers must be mounted away from the table, and the laser sheet has to be delivered precisely and stably to the measurement station. Here, high-power multi-mode step-index fiber optics enable introduction of light from an Nd:YLF pulsed laser to a remote test section. Such lasers are suitable for coupling to optical fibers, which presents a portable, flexible, and safe manner to deliver a PIV light sheet. Best practices for their implementation are reviewed. Particular attention is focused on obtaining a collimated beam of acceptable quality at the output of the fiber. To achieve high spatial resolution, the PIV camera is directly mounted on the moving shake table with care to minimize its vibrations. A special arrangement of PIV planes is deployed for precise in-situ PIV alignment and to monitor and account for residual structure vibrations and beam wandering. The design of the instruments is detailed. Here, an experimental facility for the study of nuclear fuel bundle response to seismic forcing near prototypical conditions is instrumented. Only through integration of a high-resolution flying-PIV system can velocity fields be acquired. Data indicate that in the presence of a mean axial flow, a secondary oscillatory flow develops as the bundle oscillates. Instantaneous, phase-averaged, and fluctuating velocity fields illustrate this phenomenon.

  19. A high unburned carbon fly ash concrete’s performance characteristics

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Valderrama

    2011-01-01

    Full Text Available Engineering today requires that structures are strong and durable; the latter concept is a decisive factor in their design and construction. The scientific community continues developing new cementitious materials and improving tra-ditional concrete’s properties, specifically reducing permeability by incorporating materials such as pozzolans. This paper analyses the effect of fly ash (FA added to concrete on mechanical strength regarding compression, capillary absorption and chloride permeability and their behaviour compared to concrete containing silica fume (SF. An optimum 10% mechanical strength was found for fly ash; however, this increased with addition, resulting in positive effects on durability. Fly ash had lower performance for all properties evaluated when compared to silica fume.

  20. Fly ash porous material using geopolymerization process for high temperature exposure.

    Science.gov (United States)

    Abdullah, Mohd Mustafa Al Bakri; Jamaludin, Liyana; Hussin, Kamarudin; Bnhussain, Mohamed; Ghazali, Che Mohd Ruzaidi; Ahmad, Mohd Izzat

    2012-01-01

    This paper presents the results of a study on the effect of temperature on geopolymers manufactured using pozzolanic materials (fly ash). In this paper, we report on our investigation of the performance of porous geopolymers made with fly ash after exposure to temperatures from 600 °C up to 1000 °C. The research methodology consisted of pozzolanic materials (fly ash) synthesized with a mixture of sodium hydroxide and sodium silicate solution as an alkaline activator. Foaming agent solution was added to geopolymer paste. The geopolymer paste samples were cured at 60 °C for one day and the geopolymers samples were sintered from 600 °C to 1000 °C to evaluate strength loss due to thermal damage. We also studied their phase formation and microstructure. The heated geopolymers samples were tested by compressive strength after three days. The results showed that the porous geopolymers exhibited strength increases after temperature exposure.

  1. High-resolution nanoprobe X-ray fluorescence characterization of heterogeneous calcium and heavy metal distributions in alkali-activated fly ash.

    Science.gov (United States)

    Provis, John L; Rose, Volker; Bernal, Susan A; van Deventer, Jannie S J

    2009-10-06

    The nanoscale distribution of elements within fly ash and the aluminosilicate gel products of its alkaline activation ("fly ash geopolymers") are analyzed by means of synchrotron X-ray fluorescence using a hard X-ray Nanoprobe instrument. The distribution of calcium within a hydroxide-activated (fly ash/KOH solution) geopolymer gel is seen to be highly heterogeneous, with these data providing for the first time direct evidence of the formation of discrete high-calcium particles within the binder structure of a geopolymer synthesized from a low-calcium (geopolymer gel binder structure surrounding the unreacted fly ash particles. This has important implications for the understanding of calcium chemistry within aluminosilicate geopolymer gel phases. Additionally, chromium and iron are seen to be very closely correlated within the structures of both fly ash and the geopolymer product and remain within the regions of the geopolymer which can be identified as unreacted fly ash particles. Given that the potential for chromium release has been one of the queries surrounding the widespread utilization of construction materials derived from fly ash, the observation that this element appears to be localized within the fly ash rather than dispersed throughout the gel binder indicates that it is unlikely to be released problematically into the environment.

  2. A brief on high-volume Class F fly ash as cement replacement – A guide for Civil Engineer

    Directory of Open Access Journals (Sweden)

    Alaa M. Rashad

    2015-12-01

    Full Text Available Disposal of fly ash (FA resulting from the combustion of coal-fired electric power stations is one of the major environmental challenges. This challenge continues to increase with increasing the amount of FA and decreasing the capacity of landfill space. Therefore, studies have been carried out to re-use high-volumes of fly ash (HVFA as cement replacement in building materials. This paper presents an overview of the previous studies carried out on the use of high volume Class F FA as a partial replacement of cement in traditional paste/mortar/concrete mixtures based on Portland cement (PC. Fresh properties, mechanical properties, abrasion resistance, thermal properties, drying shrinkage, porosity, water absorption, sorptivity, chemical resistance, carbonation resistance and electrical resistivity of paste/mortar/concrete mixtures containing HVFA (⩾45% as cement replacement have been reviewed. Furthermore, additives used to improve some properties of HVFA system have been reviewed.

  3. A fiber-optic-based calibration system for the High Resolution Fly's Eye cosmic ray observatory

    Energy Technology Data Exchange (ETDEWEB)

    Girard, J.H.V.; Wiencke, L.R. E-mail: wiencke@cosmic.utah.edu; Archbold, G.C.; Bellido, J.A.; Belov, K.; Boyer, J.H.; Everett, A.A.; Gray, R.C.; Jui, C.C.H.; Knapp, B.C.; Mannel, E.J.; Matthews, J.N.; Moore, S.A.; Mumford, J.R.; Roberts, M.D.; Shen, P.; Sokolsky, P.V.; Springer, R.W.; Thomas, S.B

    2001-03-21

    This article describes the fiber-optic-based calibration system installed at the High Resolution Fly's Eye (HiRes) astro-particle physics observatory. The HiRes detectors measure ultra violet scintillation light from distant extensive air showers. This automated calibration system delivers light from a frequency tripled 355 nm YAG laser to the 10,752 photo-multiplier tubes of the 42 HiRes-II detectors.

  4. Production of highly porous glass-ceramics from metallurgical slag, fly ash and waste glass

    Directory of Open Access Journals (Sweden)

    Mangutova Bianka V.

    2004-01-01

    Full Text Available Glass-ceramics composites were produced based on fly-ash obtained from coal power stations, metallurgical slag from ferronickel industry and waste glass from TV monitors, windows and flasks. Using 50% waste flask glass in combination with fly ash and 20% waste glass from TV screens in combination with slag, E-modulus and bending strength values of the designed systems are increased (system based on fly ash: E-modulus from 6 to 29 GPa, and bending strength from 9 to 75 MPa. The polyurethane foam was used as a pore creator which gave the material porosity of 70(5% (fly ash-glass composite and a porosity of 65( 5% (slag-glass composite. E-modulus values of the designed porous systems were 3.5(1.2 GPa and 8.1(3 GPa, while the bending strength values were 6.0(2 MPa and 13.2(3.5 MPa, respectively. These materials could be used for the production of tiles, wall bricks, as well as for the construction of air diffusers for waste water aeration.

  5. FOCUSING BY A HIGH-POWER, LOW-FRESNEL-NUMBER LENS - THE FLY FACET LENS

    NARCIS (Netherlands)

    STAVENGA, DG; VANHATEREN, JH

    1991-01-01

    Diffraction by fly facet lenses has been investigated by photographing the diffraction patterns at various distances from a facet lens whose power was estimated to be 2.03 x 10(4) D. We studied three different aperture diameters with Fresnel numbers of the order of unity. A large focal shift was pro

  6. Focusing by a high-power, low-Fresnel-number lens : the fly facet lens

    NARCIS (Netherlands)

    Stavenga, D.G.; Hateren, J.H. van

    1991-01-01

    Diffraction by fly facet lenses has been investigated by photographing the diffraction patterns at various distances from a facet lens whose power was estimated to be 2.03 x 10(4) D. We studied three different aperture diameters with Fresnel numbers of the order of unity. A large focal shift was pro

  7. A comparative study of self-consolidating concretes incorporating high-volume natural pozzolan or high-volume fly ash

    KAUST Repository

    Celik, Kemal

    2014-09-01

    The purpose of this study is to compare the effects of Portland cement replacement on the strength and durability of self-consolidating concretes (SSC). The two replacement materials used are high-volume natural pozzolan (HVNP), a Saudi Arabian aluminum-silica rich basaltic glass and high-volume Class-F fly ash (HVFAF), from Jim Bridger Power Plant, Wyoming, US. As an extension of the study, limestone filler (LF) is also used to replace Portland cement, alongside HVNP or HVFAF, forming ternary blends. Along with compressive strength tests, non-steady state chloride migration and gas permeability tests were performed, as durability indicators, on SCC specimens. The results were compared to two reference concretes; 100% ordinary Portland cement (OPC) and 85% OPC - 15% LF by mass. The HVNP and HVFAF concrete mixes showed strength and durability results comparable to those of the reference concretes; identifying that both can effectively be used to produce low-cost and environmental friendly SCC. © 2013 Elsevier Ltd. All rights reserved.

  8. Flow Control and High-Lift Performance for Flying-Wing Unmanned Combat Air Vehicle Configurations by inserting slots

    Directory of Open Access Journals (Sweden)

    U Ali

    2016-06-01

    Full Text Available The objectives of the present study on Unmanned Combat Air Vehicles (UCAVs are two-fold: first to control the flow by inserting leading-edge and cross-flow slots and analysing the viscous flow development over the outer panels of a flying-wing configuration to maximise the performance of the elevons control surfaces; second to predict high-lift performance particularly the maximum-lift characteristics. This is demonstrated using a variety of inviscid Vortex Lattice Method (VLM and Euler, and viscous CFD Reynolds Averaged Navier-Stokes (RANS methods. The computational results are validated against experiment measured in a wind tunnel. Two flying-wing planforms are considered based around a generic 40˚ edge-aligned configuration. The VLM predicts a linear variation of lift and pitching moment with incidence angle, and substantially under-predicts the induced drag. Results obtained from RANS and Euler agree well with experiment.

  9. Design of a smart optically controlled high-power switch for fly-by-light motor actuation systems

    Science.gov (United States)

    Bhadri, Prashant; Sukumaran, Deepti; Dasgupta, Samhita; Beyette, Fred R., Jr.

    2001-12-01

    In avionic systems, data integrity and high data rates are necessary for stable flight control. Unfortunately, conventional electronic control systems are susceptible to electromagnetic interference (EMI) that can reduce the clarity of flight control signals. Fly-by-Light systems that use optical signals to actuate the flight control surfaces of an aircraft have been suggested as a solution to the EMI problem in avionic systems. Fly-by-Light in avionic systems reduces electromagnetic interference hence improving the clarity of the control signals. A hybrid approach combining a silicon photoreceiver module with a SiC power transistor is proposed. The resulting device uses a 5 mW optical control signal to produce a 150 A current suitable for driving an electric motor.

  10. High genetic diversity in the offshore island populations of the tephritid fruit fly Bactrocera dorsalis.

    Science.gov (United States)

    Yi, Chunyan; Zheng, Chunyan; Zeng, Ling; Xu, Yijuan

    2016-10-13

    Geographic isolation is an important factor that limit species dispersal and thereby affects genetic diversity. Because islands are often small and surrounded by a natural water barrier to dispersal, they generally form discrete isolated habitats. Therefore, islands may play a key role in the distribution of the genetic diversity of insects, including flies. To characterize the genetic structure of island populations of Bactrocera dorsalis, we analyzed a dataset containing both microsatellite and mtDNA loci of B. dorsalis samples collected from six offshore islands in Southern China. The microsatellite data revealed a high level of genetic diversity among these six island populations based on observed heterozygosity (Ho), expected heterozygosity (HE), Nei's standard genetic distance (D), genetic identity (I) and the percentage of polymorphic loci (PIC). These island populations had low F ST values (F ST = 0.04161), and only 4.16 % of the total genetic variation in the species was found on these islands, as determined by an analysis of molecular variance. Based on the mtDNA COI data, high nucleotide diversity (0.9655) and haplotype diversity (0.00680) were observed in all six island populations. F-statistics showed that the six island populations exhibited low or medium levels of genetic differentiation among some island populations. To investigate the population differentiation between the sampled locations, a factorial correspondence analysis and both the unweighted pair-group method with arithmetic mean and Bayesian clustering methods were used to analyze the microsatellite data. The results showed that Hebao Island, Weizhou Island and Dong'ao Island were grouped together in one clade. Another clade consisted of Shangchuan Island and Naozhou Island, and a final, separate clade contained only the Wailingding Island population. Phylogenetic analysis of the mtDNA COI sequences revealed that the populations on each of these six islands were closely related to

  11. Utilize Cementitious High Carbon Fly Ash (CHCFA) to Stabilize Cold In-Place Recycled (CIR) Asphalt Pavement as Base Coarse

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Haifang; Li, Xiaojun; Edil, Tuncer; O' Donnell, Jonathan; Danda, Swapna

    2011-02-05

    The purpose of this study was to evaluate the performance of cementitious high carbon fly ash (CHCFA) stabilized recycled asphalt pavement as a base course material in a real world setting. Three test road cells were built at MnROAD facility in Minnesota. These cells have the same asphalt surface layers, subbases, and subgrades, but three different base courses: conventional crushed aggregates, untreated recycled pavement materials (RPM), and CHCFA stabilized RPM materials. During and after the construction of the three cells, laboratory and field tests were carried out to characterize the material properties. The test results were used in the mechanistic-empirical pavement design guide (MEPDG) to predict the pavement performance. Based on the performance prediction, the life cycle analyses of cost, energy consumption, and greenhouse gasses were performed. The leaching impacts of these three types of base materials were compared. The laboratory and field tests showed that fly ash stabilized RPM had higher modulus than crushed aggregate and RPM did. Based on the MEPDG performance prediction, the service life of the Cell 79 containing fly ash stabilized RPM, is 23.5 years, which is about twice the service life (11 years) of the Cell 77 with RPM base, and about three times the service life (7.5 years) of the Cell 78 with crushed aggregate base. The life cycle analysis indicated that the usage of the fly ash stabilized RPM as the base of the flexible pavement can significantly reduce the life cycle cost, the energy consumption, the greenhouse gases emission. Concentrations of many trace elements, particularly those with relatively low water quality standards, diminish over time as water flows through the pavement profile. For many elements, concentrations below US water drinking water quality standards are attained at the bottom of the pavement profile within 2-4 pore volumes of flow.

  12. Autogenous shrinkage prediction on high-performance concrete of fly ash based on BP neural network

    Science.gov (United States)

    Wang, Baomin; Zhang, Wenping; Wang, Lijiu

    2006-11-01

    The article adopts test data of neural network for autogenous shrinkage to train and predict on the data which doesn't join training. The article's prediction is on the basis of common medium sand, 5-31.5mm limestone rubble, second class fly-ash, P.O42.5 silicate cement, considering factors include five ones such as ratio of water and cement, sand rate, content of cement, content of fly ash, etc.By adjusting various parameters of neural network structure, it obtains three optimized results of neural network simulation. The error between concrete autogtenous shrinkage value of neural network prediction and trial value is within 3%, which can meet requirement of the concrete engineering.

  13. Conserved microsatellite markers of high cross-species utility for flying, ground and tree squirrels

    OpenAIRE

    Jumpa, S.; Dawson, D. A.; Horsburgh, G.J.; Walton, C

    2015-01-01

    Many squirrel species around the world are threatened by forest loss and fragmentation. To facilitate studies of squirrel biodiversity, particularly of flying squirrels in Southeast Asia, we identified Hylopetes, Menetes, Glaucomys and Sciurus squirrel microsatellite sequences with homologs in a second squirrel species (Spermophilus tridecemlineatus), designed 40 consensus markers and tested three squirrel species. When tested in four individuals per species, 26 markers were variable in Hylop...

  14. High chromosomal variation in wild horn fly Haematobia irritans (Linnaeus (Diptera, Muscidae populations

    Directory of Open Access Journals (Sweden)

    Natalia Forneris

    2015-02-01

    Full Text Available The horn fly, Haematobia irritans is an obligate haematophagous cosmopolitan insect pest. The first reports of attacks on livestock by H. irritans in Argentina and Uruguay occurred in 1991, and since 1993 it is considered an economically important pest. Knowledge on the genetic characteristics of the horn fly increases our understanding of the phenotypes resistant to insecticides that repeatedly develop in these insects. The karyotype of H. irritans, as previously described using flies from an inbred colony, shows a chromosome complement of 2n=10 without heterochromosomes (sex chromosomes. In this study, we analyze for the first time the chromosome structure and variation of four wild populations of H. irritans recently established in the Southern Cone of South America, collected in Argentina and Uruguay. In these wild type populations, we confirmed and characterized the previously published “standard” karyotype of 2n=10 without sex chromosomes; however, surprisingly a supernumerary element, called B-chromosome, was found in about half of mitotic preparations. The existence of statistically significant karyotypic diversity was demonstrated through the application of orcein staining, C-banding and H-banding. This study represents the first discovery and characterization of horn fly karyotypes with 2n=11 (2n=10+B. All spermatocytes analyzed showed 5 chromosome bivalents, and therefore, 2n=10 without an extra chromosome. Study of mitotic divisions showed that some chromosomal rearrangements affecting karyotype structure are maintained as polymorphisms, and multiple correspondence analyses demonstrated that genetic variation was not associated with geographic distribution. Because it was never observed during male meiosis, we hypothesize that B-chromosome is preferentially transmitted by females and that it might be related to sex determination.

  15. High chromosomal variation in wild horn fly Haematobia irritans (Linnaeus) (Diptera, Muscidae) populations

    Science.gov (United States)

    Forneris, Natalia S.; Otero, Gabriel; Pereyra, Ana; Repetto, Gustavo; Rabossi, Alejandro; Quesada-Allué, Luis A.; Basso, Alicia L.

    2015-01-01

    Abstract The horn fly, Haematobia irritans is an obligate haematophagous cosmopolitan insect pest. The first reports of attacks on livestock by Haematobia irritans in Argentina and Uruguay occurred in 1991, and since 1993 it is considered an economically important pest. Knowledge on the genetic characteristics of the horn fly increases our understanding of the phenotypes resistant to insecticides that repeatedly develop in these insects. The karyotype of Haematobia irritans, as previously described using flies from an inbred colony, shows a chromosome complement of 2n=10 without heterochromosomes (sex chromosomes). In this study, we analyze for the first time the chromosome structure and variation of four wild populations of Haematobia irritans recently established in the Southern Cone of South America, collected in Argentina and Uruguay. In these wild type populations, we confirmed and characterized the previously published “standard” karyotype of 2n=10 without sex chromosomes; however, surprisingly a supernumerary element, called B-chromosome, was found in about half of mitotic preparations. The existence of statistically significant karyotypic diversity was demonstrated through the application of orcein staining, C-banding and H-banding. This study represents the first discovery and characterization of horn fly karyotypes with 2n=11 (2n=10+B). All spermatocytes analyzed showed 5 chromosome bivalents, and therefore, 2n=10 without an extra chromosome. Study of mitotic divisions showed that some chromosomal rearrangements affecting karyotype structure are maintained as polymorphisms, and multiple correspondence analyses demonstrated that genetic variation was not associated with geographic distribution. Because it was never observed during male meiosis, we hypothesize that B-chromosome is preferentially transmitted by females and that it might be related to sex determination. PMID:25893073

  16. Flying Scared

    DEFF Research Database (Denmark)

    Dal Sie, Marco; Josiassen, Alexander

    service quality expectations and fear of flying affect travellers' flight choices on long-haul flights. The study was set in Bangkok and primary data were obtained from a large sample of travelers departing from Suvarnabhumi Airport. While service quality emerged as a relevant factor, fear of flying didn......’t turn out as a variable affecting travellers’ choices....

  17. Dust separation at high temperatures a method for cleaning fly ashes? Final report; Stoftavskiljning vid hoeg temperatur en metod foer rening av flygaska? Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Zintl, Frank [TPS Termiska Processer AB, Nykoeping (Sweden)

    2002-12-01

    An experimental study of separation of fly ashes by a filter at high temperatures, 300-650 deg C, with the purpose to study: Capture of heavy metals (Cd, Hg, Pb, Zn) in the fly ash; Relation between heavy metal capture and temperature; Relation between heavy metal capture and the availability of fuel chlorine. Pelletized forestry waste fuel was doped with heavy metals in two different forms. Pelletized Salix was also used, without doping. The study shows that: There is a strong inverse relation between the capture of heavy metals and the filter temperature; There is a strong relation between the availability of chlorine and the capture of heavy metals. Separation at 300-650 deg C gives much less heavy metals in the fly ash, however the ash is not clean enough to allow disposal in ordinary landfills. Thus, high temperature filtering does not seem to be a promising solution for producing 'clean' fly ash.

  18. The use of a non-standard high calcium fly ash in concrete and its response to accelerated curing

    Directory of Open Access Journals (Sweden)

    Atis, C. D.

    2002-09-01

    Full Text Available An experimental work was carried out to investigate the use of a non-standard high calcium fly ash in concrete. The response of the same fly ash to the accelerated curing was also explored. With three different cementitious material contents, a total of 48 concretes were produced. The water/ cement ratios were varied from 0.40 to 0.87. Compressive strengths of the moist cured cube specimens cast from the concrete mixtures made with 0%, 15%, 30% and 45% replacement of normal Portland cement with fly ash were measured at 28 days and 3 months. Accelerated compressive strengths were also measured using warmwater method and boiling-water method in accordance with the relevant ASTM and Turkish Standards. Despite the fact that the fly ash used was a non-standard, the laboratory test results showed that it could be utilized in concrete production at a replacement level between 15% and 30% by weight basis because fly ash concrete developed comparable or higher compressive strength than that of corresponding normal Portland cement concrete. The laboratory test results also indicated that the accelerated curing could be used to predict the compressive strength of fly ash concrete with 85% correlation coefficient. The amount of fly ash was found to be immaterial in the strength prediction. The relation between warm-water method and boiling-water method was of linear form with 93% correlation coefficient.

    Se llevó a cabo un trabajo experimental para investigar el uso de una ceniza volante de alto contenido en cal en el hormigón, la cual no cumple las especificaciones recogidas en norma. También, se estudió el comportamiento de la ceniza bajo un curado acelerado. Se elaboraron un total de 48 hormigones con tres proporciones diferentes de material cementante. Las relaciones agua/cemento (a/c usadas estaban comprendidas entre 0,40 y 0,87. A 28 días y 3 meses de curado, se determinaron las resistencias a compresión de probetas cúbicas de hormig

  19. "High-grade burial metamorphism of sedimentary mélange, Shoo Fly Complex, central Sierra Nevada, California"

    Science.gov (United States)

    Mendoza, Y.; Wakabayashi, J.

    2013-12-01

    The Shoo Fly Complex, California is a subduction complex metamorphosed at lower greenschist facies in much of the northern Sierra Nevada. Central Sierra Nevada exposures include higher grade assemblages. Previous studies have interpreted the higher grade rocks as gneissic granitoids representing the roots of a Paleozoic arc. Recent field work in the North Fork Mokelumne River drainage, shows that high-grade and low-grade metamorphic rocks were derived from similar subduction complex protoliths. The Shoo Fly in this region consists of mostly phyllite (metasiltstone, metasandstone, metachert), with some metabasite, and metaultramafic blocks. There is a metamorphic gradient from west to east in the field area, transitioning from sub to lower greenschist facies (white mica only) to middle and upper green schist facies (biotite) within the phyllites to amphibolite/upper amphibolite/granulite grade mica schists, gneisses, and amphibolites This gradient occurs across a zone about 1.5 km wide and this gradient is about 5 km west of the contact between the Shoo Fly Complex and plutons of the Sierra Nevada batholith. The higher-grade rocks do not have an apparent west-east metamorphic gradient. Accordingly the high-grade metamorphism does not appear to be a consequence of either contact metamorphism or raised regional geothermal gradients connected with the batholith. This conclusion is consistent with the fact that published metamorphic ages from probable correlative rocks within the central Sierra are much older than the Sierra Nevada batholith. Protoliths for the higher grade rocks appear identical to the lower grade rocks, for metaclastic rocks dominate with subordinate metacherts, metabasites, and metaultramafic rocks. The latter are represented by tremolite-talc schists. In the lower grade rocks some of the metabasite and metaultramafic blocks exhibit a higher grade of metamorphism than the surrounding metaclastic rocks and metacherts. Amphibolite and tremolite schist

  20. ICSC Problems and Perspectives of high-calcium fly ash from heat power plants in the composition of “green” building materials

    Directory of Open Access Journals (Sweden)

    Domanskaya Irina

    2016-01-01

    Full Text Available The peculiarities of the composition formation and hydraulic activity of high calcium fly ash got by burning of Kansk-Achinsk brown coals have been described. Fly ashes selected in dry state can be used as peculiar (specific binding agents (minerals on condition of their preliminary handling reducing nonuniform volume change of the ash stone during hydration and also the expansion range of their application in green building. The cavitation technologies, the organization of the fly ash granulation at heat power plants instead of hydraulic ash removal systems and enrichment by various means to extract rare-earth metals are considered to be the most perspective methods of fly ash conditioning.

  1. Evaluation of a Hopkinson bar fly-away technique for high amplitude shock accelerometer calibration

    Energy Technology Data Exchange (ETDEWEB)

    Togami, T.C.; Bateman, V.I.; Brown, F.A.

    1997-11-01

    A split Hopkinson bar technique has been developed to evaluate the performance of accelerometers that measure large amplitude pulses. An evaluation of this technique has been conducted in the Mechanical Shock Laboratory at Sandia National Laboratories (SNL) to determine its use in the practical calibration of accelerometers. This evaluation consisted of three tasks. First, the quartz crystal was evaluated in a split Hopkinson bar configuration to evaluate the quartz gage`s sensitivity and frequency response at force levels of 18,000, 35,000 and 53,000 N at ambient temperature, {minus}48 C and +74 C. Secondly, the fly away technique was evaluated at shock amplitudes of 50,000, 100,000, 150,000 and 200,000 G (1 G = 9.81 m/s{sup 2}) at ambient temperature, {minus}48 C and +74 C. Lastly, the technique was performed using a NIST calibrated reference accelerometer. Comparisons of accelerations calculated from the quartz gage data and the measured acceleration data have shown very good agreement. Based on this evaluation, the authors expect this split Hopkinson fly away technique to be certified by the SNL Primary Standards Laboratory.

  2. Mechanical properties of high dense coal fly-ash bulk materials by plasma spark sintering (SPS)

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, G.; Hasezaki, K.; Nakashita, A.; Kakuda, H. [Shimane University, Shimane (Japan). Dept. of Material Science

    2008-10-15

    Coal fly-ash bulk materials were prepared by spark plasma sintering (SPS). The as-received coal fly ash produced by Misumi Power Station (The Chugoku Electric Power Co. Inc.), had an average particle size of 19 mm and contained about 2% carbon from unburned coal. The sintering temperature was 1273 K for 10 min. The mass density of the sintered compact was 2.4 x 103 kg/m{sup 3}. After three-point flexural testing of the compact, the average flexural strength and Young's modulus were 25.6 MPa and 23.0 GPa, respectively. From the flexural strength, the Weibull modulus was found to be m = 6.13, indicating that the compact was a typical ceramics. Fractographic examination indicated that in all specimens the fracture origin was located on the bottom surface and was not an intrinsic flaw. Vickers indentation test showed that the fracture toughness was 0.61 MPa.m{sup 0.5} and the calculated critical flaw size c{sub 0}, was 0.18 mm. This c{sub 0} value was larger than that of the voids and the unburned carbon at the fracture surface. It is noteworthy that the mechanical strength of the sintered compact was not affected by the voids and unburned carbon.

  3. Effect of high temperature curing on the compressive strength of concrete incorporating large volumes of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Villarreal, R. [Universidad Autonoma de Nuevo Leon, Monterrey (Mexico)

    2001-07-01

    The effect of using different types of heat treatment on the compressive strength of concrete with and without large volumes of fly ash was studied. Curing of concrete is important to obtain a good quality concrete, but it is important to keep concrete from drying until the originally water-filled space in fresh cement paste has been filled to the desired extent by the products of hydration. In hot weather, high temperature promotes faster drying of concrete so a given degree of hydration is reached more rapidly than at lower temperatures. The provision of moist curing is advantageous because of a gradual gain in strength and because of reduced plastic shrinkage and drying shrinkage-cracking. The portland cement content in all the mixtures used in this study was 200 kg per cubic metre and the amount of fly ash varied from 0 to 33, 43, 50 and 56 per cent by mass of the total binder. A superplasticizer was used to obtain 200-220 mm slump. The compressive strength was tested at 3, 7, 14, 28, 56 days and at 6 months. Results showed that, using ASTM standard curing, the compressive strength of portland cement concrete made at 35 degrees C was reduced by about 12 per cent at 28 days compared to that of the concrete made at 23 degrees C. The AASHTO curing strength was found to be a bit higher than with the ASTM curing. The concrete made at 35 degrees C showed no loss of strength when continuous moist-curing was applied. The fly ash concrete mixtures that were cast at 35 degrees C were cured by covering them with membrane curing compounds and placed under ambient conditions. It was crucial to allow enough curing water to promote the pozzolanic reaction. The membrane curing did not allow the ingress of water to the concrete mass. 6 refs., 4 tabs., 13 figs.

  4. An improved quarantine method for mangoes against the Mexican fruit fly based on high-pressure processing combined with heat.

    Science.gov (United States)

    Velazquez, Gonzalo; Candelario, Hugo Ernesto; Ramírez, José A; Montoya, Pablo; Loera-Gallardo, Jesús; Vázquez, Manuel

    2010-05-01

    The Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae) is one of the most important insects infesting mangoes, citrus, and other fruits in Mexico and other Latin-American countries. Quarantine methods approved to destroy this insect decrease the shelf life of commodities. The objective of this study was to determine the effect of high-pressure processing using an initial temperature of 50 degrees C on the survivorship of eggs and larvae of the Mexican fruit fly. Eggs and larvae were pressurized at 25, 50, 75, 100, or 150 MPa for 0, 5, 10, or 20 min. The hatching ability of pressurized eggs of 1, 2, 3, and 4 days old and survivorship of the first, second, and third instars were registered. Further, the ability to pupate was studied in surviving third instars. The results showed that eggs were more resistant than larvae to the high-pressure processing. Treatments at 150 MPa at initial 50 degrees C for 10 min destroyed all eggs and larvae of A. ludens, indicating that this process might be useful as a quarantine method for infested mangoes or other fruits.

  5. Peculiar high temperature corrosion of martensite alloy under impact of Estonian oil shale fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Tallermo, H.; Klevtsov, I. [Thermal Engineering Department of Tallinn Technical University, Tallinn (Estonia)

    1998-12-31

    The superheaters` surfaces of oil shale steam boiler made of pearlitic and austenitic alloys, are subject to intensive corrosion, mainly due to presence of chlorine in external deposits. The applicability of martensitic alloys X1OCrMoVNb91 and X20CrMoV121 for superheaters is examined here and empirical equations allowing to predict alloys` corrosion resistance in the range of operational temperatures are established. Alloy X1OCrMoVNb91 is found been most perspective for superheaters of boilers firing fossil fuel that contain alkaline metals and chlorine. The abnormal dependence of corrosion resistance of martensitic alloys on temperature is revealed, namely, corrosion at 580 deg C in presence of oil shale fly ash is more intensive than at 620 deg C. (orig.) 2 refs.

  6. High temperature and hexane break pupal diapause in the flesh fly, Sarcophaga crassipalpis, by activating ERK/MAPK.

    Science.gov (United States)

    Fujiwara, Yoshihiro; Denlinger, David L

    2007-12-01

    Pupal diapause in the flesh fly, Sarcophaga crassipalpis, can be terminated by exposure to high temperatures or, artificially, with a topical application of organic solvents. To analyze the molecular mechanisms involved in diapause termination we explored the possibility that the mitogen-activated protein kinases (MAPK) are involved in this response. Levels of phospho-ERK increased within 10 min after hexane application. Extracellular signal-regulated kinase (ERK) was also activated when pupae were transferred from 20 to 25 degrees C, thus suggesting that ERK activation is a likely component of the signal transduction pathway used to initiate development in response to diapause-terminating signals. 20-Hydroxyecdysone and cyclic GMP terminate diapause in this fly, and the juvenile hormone analog methoprene shortens the diapause, but none of these agents activated ERK. ERK was readily activated in isolated abdomens treated with hexane, thus we conclude that ERK is directly activated by the hexane treatment. ERK activation was evident in the brain, epidermis, midgut and fat body, but not in the ventral nerve mass or ring gland, thus suggesting that ERK does not act directly on the ring gland to promote ecdysteroid synthesis but exerts its effect through stimulation of the brain.

  7. Tropical tephritid fruit fly community with high incidence of shared Wolbachia strains as platform for horizontal transmission of endosymbionts.

    Science.gov (United States)

    Morrow, J L; Frommer, M; Shearman, D C A; Riegler, M

    2014-12-01

    Wolbachia are endosymbiotic bacteria that infect 40-65% of arthropod species. They are primarily maternally inherited with occasional horizontal transmission for which limited direct ecological evidence exists. We detected Wolbachia in 8 out of 24 Australian tephritid species. Here, we have used multilocus sequence typing (MLST) to further characterize these Wolbachia strains, plus a novel quantitative polymerase chain reaction method for allele assignment in multiple infections. Based on five MLST loci and the Wolbachia surface protein gene (wsp), five Bactrocera and one Dacus species harboured two identical strains as double infections; furthermore, Bactrocera neohumeralis harboured both of these as single or double infections, and sibling species B. tryoni harboured one. Two Bactrocera species contained Wolbachia pseudogenes, potentially within the fruit fly genomes. A fruit fly parasitoid, Fopius arisanus shared identical alleles with two Wolbachia strains detected in one B. frauenfeldi individual. We report an unprecedented high incidence of four shared Wolbachia strains in eight host species from two trophic levels. This suggests frequent exposure to Wolbachia in this tropical tephritid community that shares host plant and parasitoid species, and also includes species that hybridize. Such insect communities may act as horizontal transmission platforms that contribute to the ubiquity of the otherwise maternally inherited Wolbachia.

  8. Assessment and comparison of three high-aluminum fly ash utilization scenarios in Inner Mongolia, China using an eco-efficiency indicator.

    Science.gov (United States)

    Yang, Shuo; Lin, Ling; Li, Shao Peng; Li, Qiang; Wang, Xiu Teng; Sun, Liang

    2017-05-01

    Utilization of fly ash is of great importance in China in the context of resource and environmental crises. Different fly ash utilization processes are proposed, and some have been practically applied. However, none of these fly ash utilization pathways has been evaluated comprehensively by integrating both environmental and economic perspectives. In this study, three high-aluminum fly ash utilization methods in Mongolia were assessed and compared based on the concept of eco-efficiency. The environmental assessment was conducted in accordance with life-cycle assessment principles, and a monetization-weighting approach was applied to obtain social willingness-to-pay as a reflection of environmental impact. The environmental assessment results revealed that the reuse of fly ash had significant advantage for saving primary resource, while solid waste, depletion of water, and global warming were the three highest environmental impacts from the life cycle perspective. The economic performance assessment showed positive net profits for fly ash utilization, but high value-added products were not necessarily indicative of better economic performance due to the relatively high operation cost. Comparison of the eco-efficiency indicators (EEIs) implied that the process of scenario 1#, which produced mullite ceramic and active calcium silicate, was the most recommended out of the three scenarios on the present scale. This judgment was consistent with the evaluation of the resource utilization rate. The present study showed that the EEI could be used to compare different fly ash utilization processes in a comprehensive and objective manner, thus providing definitive and insightful suggestions for decision-making and technical improvement.

  9. Photogrammetry and ballistic analysis of a high-flying projectile in the STS-124 space shuttle launch

    CERN Document Server

    Metzger, Philip T; Carilli, Robert A; Long, Jason M; Shawn, Kathy L

    2009-01-01

    A method combining photogrammetry with ballistic analysis is demonstrated to identify flying debris in a rocket launch environment. Debris traveling near the STS-124 Space Shuttle was captured on cameras viewing the launch pad within the first few seconds after launch. One particular piece of debris caught the attention of investigators studying the release of flame trench fire bricks because its high trajectory could indicate a flight risk to the Space Shuttle. Digitized images from two pad perimeter high-speed 16-mm film cameras were processed using photogrammetry software based on a multi-parameter optimization technique. Reference points in the image were found from 3D CAD models of the launch pad and from surveyed points on the pad. The three-dimensional reference points were matched to the equivalent two-dimensional camera projections by optimizing the camera model parameters using a gradient search optimization technique. Using this method of solving the triangulation problem, the xyz position of the o...

  10. Characterization of morphology and hydration products of high-volume fly ash paste by monochromatic scanning x-ray micro-diffraction (μ-SXRD)

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sungchul [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States); Meral, Cagla [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States); Department of Civil Engineering, Middle East Technical University, 06800 Ankara (Turkey); Oh, Jae-eun [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Moon, Juhyuk [Civil Engineering Program, Department of Mechanical Engineering, State University of New York at Stony Brook, NY 11794 (United States); Kunz, Martin [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Monteiro, Paulo J.M., E-mail: monteiro@ce.berkeley.edu [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)

    2014-05-01

    The present study focuses on identification and micro-structural characterization of the hydration products formed in high-volume fly ash (HVFA)/portland cement (PC) systems using monochromatic scanning x-ray micro-diffraction (μ-SXRD) and SEM-EDS. Pastes with up to 80% fly ash replacement were studied. Phase maps for HVFA samples using μ-SXRD patterns prove that μ-SXRD is an effective method to identify and visualize the distribution of phases in the matrix. μ-SXRD and SEM-EDS analysis shows that the C-S-H formed in HVFA system containing 50% or more of fly ash has a similar structure as C-S-H(I) with comparatively lower Ca/Si ratio than the one produced in PC system. Moreover, coexistence of C-S-H(I) and strätlingite is observed in the system containing 80% of fly ash, confirming that the amount of alumina and silicate phases provided by the fly ash is a major factor for the formation of C-S-H(I) and strätlingite in HVFA system. - Highlights: • High-volume fly ash (HVFA) paste was studied by scanning x-ray micro-diffraction. • Coexistence of C-S-H(I) and strätlingite in the HVFA system is clearly shown. • The distribution of minor phases in the HVFA system is shown. • Differences between inner and outer products of fly ash are observed by SEM-EDS.

  11. Fruit fly optimization algorithm based high efficiency and low NOx combustion modeling for a boiler

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenxing∗; SUN Baomin; XIN Jing

    2014-01-01

    In order to control NOx emissions and enhance boiler efficiency in coal-fired boilers,the thermal operating data from an ultra-supercritical 1 000 MW unit boiler were analyzed.On the basis of the support vector regression machine (SVM),the fruit fly optimization algorithm (FOA)was applied to optimize the penalty parameter C,ker-nel parameter g and insensitive loss coefficient of the model.Then,the FOA-SVM model was established to predict the NOx emissions and boiler efficiency,and the performance of this model was compared with that of the GA-SVM model optimized by genetic algorithm (GA).The results show the FOA-SVM model has better prediction accuracy and generalization capability,of which the maximum average relative error of testing set lies in the NOx emissions model,which is only 3 .5 9%.The above models can predict the NOx emissions and boiler efficiency accurately,so they are very suitable for on-line modeling prediction,which provides a good model foundation for further optimiza-tion operation of large capacity boilers.

  12. Time flies

    DEFF Research Database (Denmark)

    Wit, Janneke

    , the LS fly might be able to spend energy more generously on different tasks. Therefor, the capacity of LS and C lines to locate resources in a natural environment was tested. It turns out that LS flies are less likely to find food than C flies in such a setting, yet that as they age, their ability...... to locate food decreases slower than that of C lines. Gene expression of 10 candidate genes for longevity was quantified in two types of C and LS lines at three different ages. One of these genes, CG32638, indeed appears to be involved in life span determination in both males and females, regardless...... of mating status. Generalising studies on ageing in D. melanogaster can be cumbersome, especially in light of discrepancy between correlated responses between studies. To elucidate which mechanisms might be conserved due to evolutionary constraints, life span of 13 species of Drosophila was determined...

  13. Flying Cities

    DEFF Research Database (Denmark)

    Herbelin, Bruno; Lasserre, Sebastien; Ciger, Jan

    2008-01-01

    . This cross-modal interaction not only supports our artistic messages, but also aims at providing anyone with a pleasant and stimulating feedback from her/his speech activity. As the feedback we have received when presenting Flying Cities was very positive, our objective is now to cross the bridge between art......Flying Cities is an artistic installation which generates imaginary cities from the speech of its visitors. Thanks to an original interactive process analyzing people's vocal input to create 3D graphics, a tangible correspondence between speech and visuals opens new possibilities of interaction...

  14. Freeze-Thaw Resistance of Normal and High Strength Concretes Produced with Fly Ash and Silica Fume

    Directory of Open Access Journals (Sweden)

    Cenk Karakurt

    2015-01-01

    Full Text Available This study is based on determination of the freeze-thaw resistance of air-entrained and non-air-entrained normal strength concrete (NC and high strength concrete (HSC produced with fly ash and silica fume according to surface scaling. The procedure allows us to measure the amount of scaling per unit surface area due to a number of well defined freezing and thawing cycles in the presence of deicing salt. The weight loss, surface scaling, moisture uptake, and internal damage were measured after 0 and after every 4th freeze-thaw cycle. The test results showed that the freeze-thaw resistance is influenced directly by the compressive strength property of the concrete. Silica fume significantly reduced the resistance of normal strength concrete against freeze-thaw effect without plasticizing agent. The surface scaling of silica fume concrete without admixture was 22% higher than reference normal concrete.

  15. Dielectric properties of fly ash

    Indian Academy of Sciences (India)

    S C Raghavendra; R L Raibagkar; A B Kulkarni

    2002-02-01

    This paper reports the dielectric properties of fly ash. The dielectric measurements were performed as a function of frequency and temperature. The sample of fly ash shows almost similar behaviour in the frequency and temperature range studied. The large value of dielectric constant in the typical frequency range is because of orientation polarization and tight binding force between the ions or atoms in the fly ash. The sample of fly ash is of great scientific and technological interest because of its high value of dielectric constant (104).

  16. A high-throughput detection method for invasive fruit fly (Diptera: Tephritidae) species based on microfluidic dynamic array.

    Science.gov (United States)

    Jiang, Fan; Fu, Wei; Clarke, Anthony R; Schutze, Mark Kurt; Susanto, Agus; Zhu, Shuifang; Li, Zhihong

    2016-11-01

    Invasive species can be detrimental to a nation's ecology, economy and human health. Rapid and accurate diagnostics are critical to limit the establishment and spread of exotic organisms. The increasing rate of biological invasions relative to the taxonomic expertise available generates a demand for high-throughput, DNA-based diagnostics methods for identification. We designed species-specific qPCR primer and probe combinations for 27 economically important tephritidae species in six genera (Anastrepha, Bactrocera, Carpomya, Ceratitis, Dacus and Rhagoletis) based on 935 COI DNA barcode haplotypes from 181 fruit fly species publically available in BOLD, and then tested the specificity for each primer pair and probe through qPCR of 35 of those species. We then developed a standardization reaction system for detecting the 27 target species based on a microfluidic dynamic array and also applied the method to identify unknown immature samples from port interceptions and field monitoring. This method led to a specific and simultaneous detection for all 27 species in 7.5 h, using only 0.2 μL of reaction system in each reaction chamber. The approach successfully discriminated among species within complexes that had genetic similarities of up to 98.48%, while it also identified all immature samples consistent with the subsequent results of morphological examination of adults which were reared from larvae of cohorts from the same samples. We present an accurate, rapid and high-throughput innovative approach for detecting fruit flies of quarantine concern. This is a new method which has broad potential to be one of international standards for plant quarantine and invasive species detection. © 2016 John Wiley & Sons Ltd.

  17. Host Suitability of House Fly, Musca domestica (Diptera: Muscidae, Pupae Killed by High or Low Temperature Treatment for a Parastoid, Spalangia endius (Hymenoptera: Pteromalidae

    Directory of Open Access Journals (Sweden)

    Kohei Ogawa

    2012-01-01

    Full Text Available The objective of this study was to establish a high quality progeny production system for the house fly parasitoid, Spalangia endius (Hymenoptera: Pteromalidae, by stockpiling hosts. We performed two host killing methods before host storage: (i heat-killed by 30 min exposure to 50°C or (ii freeze-killed by 10 min exposure to −80°C. The average number of parasitoids that emerged from nonstored house fly pupae after heat- or freeze-killing was not significantly different from live pupae. When house fly pupae stored at −20°C after heat-killing were supplied to S. endius, progeny production was significantly less than live pupae. Moreover, productivity became very low when house fly pupae refrigerated at 3°C after heat- or freeze-killing were supplied to S. endius. On the other hand, when house fly pupae stored at −80°C for 1 year after heat-killing were supplied to S. endius, the average number of parasitoids that emerged was not significantly different from live pupae. The average number of parasitoids that emerged from freeze-killed hosts kept for more than 8 weeks at −80°C was significantly fewer than live pupae. Thus, this study clarified that a higher-quality host can be maintained not only by simply storing at –80°C but also by adding heat treatment before storage.

  18. Limits to the host range of the highly polyphagous tephritid fruit fly Anastrepha ludens in its natural habitat.

    Science.gov (United States)

    Birke, A; Acosta, E; Aluja, M

    2015-12-01

    Anastepha ludens (Diptera: Tephritidae) is a highly polyphagous fruit fly that is able to develop in a wide range of hosts. Understanding the limits of this pest's host range could provide valuable information for pest management and plant breeding for pest resistance. Previous studies have shown that guavas (Psidium guajava (Myrtaceae) L.), are not attacked under natural conditions by A. ludens. To understand this phenomenon, guavas were exposed to natural infestation by A. ludens and to other fruit fly species that infest guavas in nature (Anastrepha striata Schiner, Anastepha fraterculus (Wiedemann), Anastepha obliqua (Macquart)). Once the susceptible phenological stage of guavas was determined, fruit infestation levels were compared between A. ludens and A. striata. Choice and non-choice tests were performed under field-cage conditions. Under field conditions, guavas were susceptible to A. striata and A. fraterculus attack all the way from when fruit was undeveloped to when fruit began to ripen. No infestation by A. ludens was recorded under natural conditions. Similar results were obtained when forced exposures were performed, indicating that unripe guavas were preferred by A. striata over ripe fruit, and that infestation rates were higher at early fruit maturity stages. Under forced oviposition conditions, A. ludens larvae were unable to develop in unripe guavas but did so in fully ripe fruit. However, A. ludens fitness parameters were dramatically affected, exhibiting reduced survival and reduced pupal weight compared to conspecifics that developed in a natural host, grapefruit. We confirm that P. guajava should not be treated as a natural host of this pestiferous species, and suggest that both behavioral aspects and the fact that larvae are unable to adequately develop in this fruit, indeed represent clear limits to A. ludens's broad host range.

  19. Two new species of sympatric Fergusonina flies (Diptera: Fergusoninidae) from bud galls on high elevation snow gums (Eucalyptus pauciflora Sieb. ex Spreng. complex) in the Australian Alps

    Science.gov (United States)

    Two species of Fergusonina Malloch fly, F. daviesae Nelson sp.n. and F. taylori Nelson sp.n. (Diptera: Fergusoninidae), are described from terminal leaf bud galls on high elevation snow gums (Eucalyptus pauciflora complex) in the Australian Alps. These species occur in sympatry at the six locations...

  20. Flying Cities

    DEFF Research Database (Denmark)

    Ciger, Jan

    2006-01-01

    The Flying Cities artistic installation brings to life imaginary cities made from the speech input of visitors. In this article we describe the original interactive process generating real time 3D graphics from spectators' vocal inputs. This example of cross-modal interaction has the nice property...... of providing a tangible correspondence between the two spaces. This interaction mean has proved to suit the artistic expression well but it also aims at providing anyone with a pleasant and stimulating feedback from speech activity, a new medium for creativity and a way to visually perceive a vocal performance....... As the feedback we have received when presenting Flying Cities was very positive, our objective now is to cross the bridge between art and the potential applications to the rehabilitation of people with reduced mobility or for the treatment of language impairments....

  1. Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

    Science.gov (United States)

    Kristiawan, S. A.; Sunarmasto; Tyas, G. P.

    2016-02-01

    Concrete is susceptible to a variety of chemical attacks. In the sulfuric acid environment, concrete is subjected to a combination of sulfuric and acid attack. This research is aimed to investigate the degradation of self-compacting concrete (SCC) due to sulfuric acid attack based on measurement of compressive strength loss and diameter change. Since the proportion of SCC contains higher cement than that of normal concrete, the vulnerability of this concrete to sulfuric acid attack could be reduced by partial replacement of cement with fly ash at high volume level. The effect of high volume fly ash at 50-70% cement replacement levels on the extent of degradation owing to sulfuric acid will be assessed in this study. It can be shown that an increase in the utilization of fly ash to partially replace cement tends to reduce the degradation as confirmed by less compressive strength loss and diameter change. The effect of fly ash to reduce the degradation of SCC is more pronounced at a later age.

  2. High lift generation of low-aspect-ratio wings

    Science.gov (United States)

    Devoria, Adam; Mohseni, Kamran

    2016-11-01

    The time-averaged flow field in the center-span of low-aspect-ratio rectangular wings is experimentally measured. It is shown that lift stall is preceded by shedding of strong trailing-edge vorticity. The induced downwash of the tip vortices delays the growth of the attached boundary layer as well as leading-edge separation. Reattached flow occurs for sufficiently low aspect ratios and results in a smooth merging of the flow at the trailing edge thus assisting in satisfying a Kutta condition there. As a consequence, the strength of vorticity shed from the trailing edge is decreased and allows for continued lift generation at high angles of attack. When the reattachment point passes beyond the trailing edge, a strong shear layer is generated there and represents negative lift, leading to stall with a slight increase in angle of attack or aspect ratio.

  3. Susceptibility of low-chill blueberry cultivars to Mediterranean fruit fly, oriental fruit fly, and melon fly (Diptera: Tephritidae).

    Science.gov (United States)

    Follett, Peter A; Zee, Francis T; Hamasaki, Randall T; Hummer, Kim; Nakamoto, Stuart T

    2011-04-01

    No-choice tests were conducted to determine whether fruit of southern highbush blueberry, Vaccinium corymbosum L., hybrids are hosts for three invasive tephritid fruit flies in Hawaii. Fruit of various blueberry cultivars was exposed to gravid female flies of Bactrocera dorsalis Hendel (oriental fruit fly), Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), or Bactrocera cucurbitae Coquillet (melon fly) in screen cages outdoors for 6 h and then held on sand in the laboratory for 2 wk for pupal development and adult emergence. Each of the 15 blueberry cultivars tested were infested by oriental fruit fly and Mediterranean fruit fly, confirming that these fruit flies will oviposit on blueberry fruit and that blueberry is a suitable host for fly development. However, there was significant cultivar variation in susceptibility to fruit fly infestation. For oriental fruit fly, 'Sapphire' fruit produced an average of 1.42 puparia per g, twice as high as that of the next most susceptible cultivar 'Emerald' (0.70 puparia per g). 'Legacy', 'Biloxi', and 'Spring High' were least susceptible to infestation, producing only 0.20-0.25 oriental fruit fly puparia per g of fruit. For Mediterranean fruit fly, 'Blue Crisp' produced 0.50 puparia per g of fruit, whereas 'Sharpblue' produced only 0.03 puparia per g of fruit. Blueberry was a marginal host for melon fly. This information will aid in development of pest management recommendations for blueberry cultivars as planting of low-chill cultivars expands to areas with subtropical and tropical fruit flies. Planting of fruit fly resistant cultivars may result in lower infestation levels and less crop loss.

  4. Kinematics of turning maneuvers in the southern flying squirrel, Glaucomys volans.

    Science.gov (United States)

    Bishop, Kristin L; Brim-Deforest, Whitney

    2008-06-01

    The ability to change direction is essential to any animal that moves around in a complex, 3D environment. In this study we present the first 3D description of body positions during gliding turns in a mammalian gliding specialist, the southern flying squirrel, Glaucomys volans. In addition, we used these kinematic data to estimate the aerodynamic forces generated by the animals and rotational velocities and accelerations of the body while turning. These results were compared with similar measurements of flying squirrels during straight glides. The two individuals used in this study differed significantly in limb position asymmetries between the two sides of their bodies and also were significantly different in measures of turning performance. The individual with better performance used limb positions consistent with a primarily lift-based turning mechanism (banked turn), whereas the individual with poorer performance used limb positions consistent with a primarily drag-based turning mechanism (crabbed turn). Both individuals employed limb movements continuously through the gliding turn, but these movements did not have any consistent relationships with body rotations or lateral acceleration. As compared with straight glides, squirrels used significantly higher angles of attack and had lower lift-to-drag ratios, but did not differ in glide angle. Contrary to the typical view of maneuvering during gliding as a simple, static form of locomotion, the results presented here indicate that mammalian gliding is a complex behavior comprising the interplay of many components of limb position and wing shape that affect the balance of forces that control the turn.

  5. Pure, single phase, high crystalline, chamfered-edge zeolite 4A synthesized from coal fly ash for use as a builder in detergents.

    Science.gov (United States)

    Hui, K S; Chao, C Y H

    2006-09-01

    Single phase chamfered-edge zeolite 4A samples in pure form with a high crystallinity were synthesized by applying step-change of synthesis temperature during hydrothermal treatment of coal fly ash. The calcium binding capacity of these zeolite 4A samples (prepared from coal fly ash) and the commercial detergent grade zeolite 4A were tested for usage as a detergent builder. The results show that these zeolite 4A samples behaved similarly as the commercial one in removing calcium ions during the washing cycle. Moreover, from the leaching tests (evaluation of toxicological safety), the results show that these zeolite 4A samples leached the same elements (Sb, As, Se and Tl) as the commercial one with the concentrations in the same order of magnitude. This shows that the toxicological effect of the coal fly ash converted zeolite 4A was not worse than that of the commercial sample. Finally, economic and environmental aspects of converting coal fly ash to useful products were discussed.

  6. Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

    Science.gov (United States)

    Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  7. Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

    Full Text Available This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA as partial replacement of cement in presence of copolymer latexes. Portland cement (PC was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA and 2-hydroxymethylacrylate (2-HEMA. Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM. The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  8. The Energy Spectrum of Telescope Array's Middle Drum Detector and the Direct Comparison to the High Resolution Fly's Eye Experiment

    CERN Document Server

    Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Cheon, B G; Chiba, J; Chikawa, M; Cho, E J; Cho, W R; Fujii, H; Fujii, T; Fukuda, T; Fukushima, M; Gorbunov, D; Hanlon, W; Hayashi, K; Hayashi, Y; Hayashida, N; Hibino, K; Hiyama, K; Honda, K; Iguchi, T; Ikeda, D; Ikuta, K; Inoue, N; Ishii, T; Ishimori, R; Ivanov, D; Iwamoto, S; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kanbe, T; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kido, E; Kim, H B; Kim, H K; Kim, J H; Kim, J H; Kitamoto, K; Kitamura, S; Kitamura, Y; Kobayashi, K; Kobayashi, Y; Kondo, Y; Kuramoto, K; Kuzmin, V; Kwon, Y J; Lim, S I; Machida, S; Martens, K; Martineau, J; Matsuda, T; Matsuura, T; Matsuyama, T; Matthews, J N; Minamino, M; Miyata, K; Murano, Y; Nagataki, S; Nakamura, T; Nam, S W; Nonaka, T; Ogio, S; Ohnishi, M; Ohoka, H; Oki, K; Oku, D; Okuda, T; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Roh, S Y; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, J I; Shirahama, T; Smith, J D; Sokolsky, P; Sonley, T J; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T; Suzuki, S; Takahashi, Y; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Tsuyuguchi, Y; Uchihori, Y; Udo, S; Ukai, H; Vasiloff, G; Wada, Y; Wong, T; Wood, M; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zollinger, R; Zundel, Z

    2012-01-01

    The Telescope Array's Middle Drum fluorescence detector was instrumented with telescopes refurbished from the High Resolution Fly's Eye's HiRes-1 site. The data observed by Middle Drum in monocular mode was analyzed via the HiRes-1 profile-constrained geometry reconstruction technique and utilized the same calibration techniques enabling a direct comparison of the energy spectra and energy scales between the two experiments. The spectrum measured using the Middle Drum telescopes is based on a three-year exposure collected between December 16, 2007 and December 16, 2010. The calculated difference between the spectrum of the Middle Drum observations and the published spectrum obtained by the data collected by the HiRes-1 site allows the HiRes-1 energy scale to be transferred to Middle Drum. The HiRes energy scale is applied to the entire Telescope Array by making a comparison between Middle Drum monocular events and hybrid events that triggered both Middle Drum and the Telescope Array's scintillator Ground Arra...

  9. Performance of double-layer biofilter packed with coal fly ash ceramic granules in treating highly polluted river water.

    Science.gov (United States)

    Jing, Zhaoqian; Li, Yu-You; Cao, Shiwei; Liu, Yuyu

    2012-09-01

    To improve trickling filters' denitrification efficiency, a biofilter with a trickling upper layer and a submerged lower layer was developed and applied in treating highly polluted river water. It was packed with porous coal fly ash ceramic granules. Its start-up characteristics, influence of hydraulic loading rates (HLR), carbon/nitrogen (C/N) ratio and filter depth on pollutants removal were investigated. The results indicated this biofilter was started quickly in 16 days with river sediment as inoculum. Alternating nitrification and denitrification were achieved when water flowed downwards. COD and nitrogen were mainly removed in the upper layer and the lower layer, respectively. With HLR of 4.0-5.0m(3)/(m(2)d), chemical oxygen demand (COD), ammonium (NH(4)(+)-N) and total nitrogen (TN) in the effluent were below 50, 5 and 15 mg/L, respectively. This biofilter removed more than 80% of COD, 85% of NH(4)(+)-N and 60% of TN with C/N ratios ranging from 6 to 10.

  10. On-the-fly machine-learning for high-throughput experiments: search for rare-earth-free permanent magnets.

    Science.gov (United States)

    Kusne, Aaron Gilad; Gao, Tieren; Mehta, Apurva; Ke, Liqin; Nguyen, Manh Cuong; Ho, Kai-Ming; Antropov, Vladimir; Wang, Cai-Zhuang; Kramer, Matthew J; Long, Christian; Takeuchi, Ichiro

    2014-09-15

    Advanced materials characterization techniques with ever-growing data acquisition speed and storage capabilities represent a challenge in modern materials science, and new procedures to quickly assess and analyze the data are needed. Machine learning approaches are effective in reducing the complexity of data and rapidly homing in on the underlying trend in multi-dimensional data. Here, we show that by employing an algorithm called the mean shift theory to a large amount of diffraction data in high-throughput experimentation, one can streamline the process of delineating the structural evolution across compositional variations mapped on combinatorial libraries with minimal computational cost. Data collected at a synchrotron beamline are analyzed on the fly, and by integrating experimental data with the inorganic crystal structure database (ICSD), we can substantially enhance the accuracy in classifying the structural phases across ternary phase spaces. We have used this approach to identify a novel magnetic phase with enhanced magnetic anisotropy which is a candidate for rare-earth free permanent magnet.

  11. On-the-fly machine-learning for high-throughput experiments: search for rare-earth-free permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Kusne, Aaron Gilad [University of Maryland; Gao, Tieren [University of Maryland; Mehta, Apurva [SLAC National Accelerator Laboratory; Ke, Liqin [Ames Laboratory; Nguyen, Manh Cuong [Ames Laboratory; Ho, Kai-Ming [Ames Laboratory; Antropov, Vladimir [Ames Laboratory; Wang, Cai-Zhuang [Ames Laboratory; Kramer, Matthew J [Ames Laboratory; Long, Christian [University of Maryland; Takeuchi, Ichiro [University of Maryland

    2014-09-15

    Advanced materials characterization techniques with ever-growing data acquisition speed and storage capabilities represent a challenge in modern materials science, and new procedures to quickly assess and analyze the data are needed. Machine learning approaches are effective in reducing the complexity of data and rapidly homing in on the underlying trend in multi-dimensional data. Here, we show that by employing an algorithm called the mean shift theory to a large amount of diffraction data in high-throughput experimentation, one can streamline the process of delineating the structural evolution across compositional variations mapped on combinatorial libraries with minimal computational cost. Data collected at a synchrotron beamline are analyzed on the fly, and by integrating experimental data with the inorganic crystal structure database (ICSD), we can substantially enhance the accuracy in classifying the structural phases across ternary phase spaces. We have used this approach to identify a novel magnetic phase with enhanced magnetic anisotropy which is a candidate for rare-earth free permanent magnet.

  12. High tensile strength fly ash based geopolymer composite using copper coated micro steel fiber

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mehdi; Mehrali, Mohammad

    2016-01-01

    As a ceramic-like material, geopolymers show a high quasi-brittle behavior and relatively low fracture energy. To overcome this, the addition of fibers to a brittle matrix is a well-known method to improve the flexural strength. Moreover, the success of the reinforcements is dependent on the fibe...

  13. Flying Cities

    DEFF Research Database (Denmark)

    Ciger, Jan

    2006-01-01

    of providing a tangible correspondence between the two spaces. This interaction mean has proved to suit the artistic expression well but it also aims at providing anyone with a pleasant and stimulating feedback from speech activity, a new medium for creativity and a way to visually perceive a vocal performance......The Flying Cities artistic installation brings to life imaginary cities made from the speech input of visitors. In this article we describe the original interactive process generating real time 3D graphics from spectators' vocal inputs. This example of cross-modal interaction has the nice property...

  14. Flying Fortress

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    当欧洲的年轻人想到关于德国的两种熊,一个是传统的布娃娃熊,另一个就是充满欧洲街头墙上的Teddy熊涂鸦,而这个涂鸦熊的创作者就是著名的涂鸦艺术家“Flying Fortress”,他称这些熊军队为“Teddy Tmops”。

  15. The Kilimanjaro score for assessing fitness to fly paragliders at high altitude.

    Science.gov (United States)

    Wilkes, Matt; Simpson, Alistair; Knox, Matt; Summers, Luke

    2013-09-01

    Extreme sports such as paragliding are increasing in popularity, providing continued challenges for the development of safe practice techniques. In January and February 2013, the Wings of Kilimanjaro expedition aimed to launch 95 paragliders from the summit of Mount Kilimanjaro, 5790 m above sea level. A safe launch was paramount but risked being impaired by adverse environmental conditions, in particular the pathophysiological effects of high altitude. There are no existing scores to assess fitness for high-altitude paraglider launches present in the literature. A novel scoring system, the Kilimanjaro Score, was therefore developed to rapidly assess pilots pre-flight. The Kilimanjaro Score aimed to assess cognition, memory, and visual-spatial skill within the context of standard pre-flight checks. Further testing, including the Lake Louise Score, was to be performed if the pilot's Kilimanjaro Score was deemed unsatisfactory. We present the Kilimanjaro Score here for comment and refinement, and we invite other parties to consider its use in the field for high altitude paragliding activities.

  16. Total flying hours and risk of high systolic blood pressure in the civilian pilot in Indonesia

    Directory of Open Access Journals (Sweden)

    Ferdi Afian

    2016-07-01

    Full Text Available Abstrak Latar belakang: Tekanan darah sistolik tinggi di antara pilot sipil antara lain akan menyebabkan gangguan kardiovaskular sehingga akan mengganggu kelancaran penerbangan. Tujuan penelitian ini ialah untuk mengetahui faktor-faktor dominan terhadap tekanan darah sistolik tinggi pada pilot sipil. Metode: Penelitian potong lintang dengan metode sampling purposif pada pilot yang melakukan pemeriksaan kesehatan berkala di Balai Kesehatan Penerbangan pada tanggal 18-29 Mei 2015. Data yang dikumpulkan adalah karakteristik demografi dan pekerjaan, klinis, kebiasaan olahraga, kebiasaan makan, indeks massa tubuh dan riwayat penyakit. Tekanan darah sistolik tinggi ialah tekanan darah sistolik140 mmHg atau lebih. Hasil: Dari 690 pilot yang melakukan pemeriksaan kesehatan berkala, 428 pilot laki-laki bersedia berpartisipasi mengikuti penelitian ini. Usia dan riwayat penyakit hipertensi merupakan faktor risiko dominan yang berhubungan dengan tekanan darah sistolik tinggi. Jika dibandingkan dengan pilot usia 19-39 tahun, yang berusia 40-65 tahun mempunyai 15,1 kali lipat lebih besar risiko terkena tekanan darah sistolik tinggi [rasio odds suaian (ORa= 15,12; p= 0,001]. Pilot dengan riwayat penyakit hipertensi dibandingkan dengan yang tidak ada riwayat memiliki risiko tekanan darah sistolik tinggi 93,2 kali lipat lebih besar (ORa= 93,21; p= 0,001 Kesimpulan: Usia 40-65 tahun dan memiliki riwayat hipertensi meningkatkan risiko tekanan darah sistolik tinggi di antara pilot sipil di Indonesia. Kata kunci: tekanan darah sistolik, total jam terbang, pilot sipil, Indonesia.  Abstract Background: Systolic high blood pressure among civilian pilots among others will cause cardiovascular disease and this condition will disrupt the flight.The purpose of this study was to identified the dominant factors related to high systolic blood pressure in the civilian pilots. Methods: A cross-sectional study with a purposive sampling method on a pilot who performed periodic

  17. Total flying hours and risk of high systolic blood pressure in the civilian pilot in Indonesia

    Directory of Open Access Journals (Sweden)

    Ferdi Afian

    2016-07-01

    Full Text Available Abstrak Latar belakang: Tekanan darah sistolik tinggi di antara pilot sipil antara lain akan menyebabkan gangguan kardiovaskular sehingga akan mengganggu kelancaran penerbangan. Tujuan penelitian ini ialah untuk mengetahui faktor-faktor dominan terhadap tekanan darah sistolik tinggi pada pilot sipil. Metode: Penelitian potong lintang dengan metode sampling purposif pada pilot yang melakukan pemeriksaan kesehatan berkala di Balai Kesehatan Penerbangan pada tanggal 18-29 Mei 2015. Data yang dikumpulkan adalah karakteristik demografi dan pekerjaan, klinis, kebiasaan olahraga, kebiasaan makan, indeks massa tubuh dan riwayat penyakit. Tekanan darah sistolik tinggi ialah tekanan darah sistolik140 mmHg atau lebih. Hasil: Dari 690 pilot yang melakukan pemeriksaan kesehatan berkala, 428 pilot laki-laki bersedia berpartisipasi mengikuti penelitian ini. Usia dan riwayat penyakit hipertensi merupakan faktor risiko dominan yang berhubungan dengan tekanan darah sistolik tinggi. Jika dibandingkan dengan pilot usia 19-39 tahun, yang berusia 40-65 tahun mempunyai 15,1 kali lipat lebih besar risiko terkena tekanan darah sistolik tinggi [rasio odds suaian (ORa= 15,12; p= 0,001]. Pilot dengan riwayat penyakit hipertensi dibandingkan dengan yang tidak ada riwayat memiliki risiko tekanan darah sistolik tinggi 93,2 kali lipat lebih besar (ORa= 93,21; p= 0,001 Kesimpulan: Usia 40-65 tahun dan memiliki riwayat hipertensi meningkatkan risiko tekanan darah sistolik tinggi di antara pilot sipil di Indonesia. Kata kunci: tekanan darah sistolik, total jam terbang, pilot sipil, Indonesia.  Abstract Background: Systolic high blood pressure among civilian pilots among others will cause cardiovascular disease and this condition will disrupt the flight.The purpose of this study was to identified the dominant factors related to high systolic blood pressure in the civilian pilots. Methods: A cross-sectional study with a purposive sampling method on a pilot who performed periodic

  18. Two New Species of Black Flies (Diptera: Simuliidae) from the High Andes of Colombia.

    Science.gov (United States)

    Mantilla, Juan S; Moncada, Ligia I; Matta, Nubia E; Adler, Peter H

    2013-01-01

    The females, males, pupae, and larvae of two new species of Simulium are described and illustrated from a small stream 3950 m above sea level in the Lake Otún area of the Colombian Andes Mountains. Simulium (Pternaspatha) quimbayium n. sp. represents a 630-km northeastern extension of the distributional range of previously known members of the subgenus Pternaspatha, and Simulium (Psilopelmia) machetorum n. sp. represents the highest altitude recorded for a species of the subgenus Psilopelmia. These species illustrate the unique simuliid biodiversity in the páramo ecosystem of the high northern Andes.

  19. Quantitative proteomics on the fly

    NARCIS (Netherlands)

    Gouw, J.W.

    2009-01-01

    The development of multicellular organisms is characterized by complex processes that progressively transform essentially a single cell into a creature with complicated structures and highly specialized functions. The fruit fly Drosophila melanogaster provides an excellent model system to investigat

  20. Chemistry in plumes of high-flying aircraft with H2 combustion engines: a modelling study

    Directory of Open Access Journals (Sweden)

    G. Weibring

    Full Text Available Recent discussions on high-speed civil transport (HSCT systems have renewed the interest in the chemistry of supersonic-aircraft plumes. The engines of these aircraft emit large concentrations of radicals like O, H, OH, and NO. In order to study the effect of these species on the composition of the atmosphere, the detailed chemistry of an expanding and cooling plume is examined for different expansion models.

    For a representative flight at 26 km the computed trace gas concentrations do not differ significantly for different models of the expansion behaviour. However, it is shown that the distributions predicted by all these models differ significantly from those adopted in conventional meso-scale and global models in which the plume chemistry is not treated in detail. This applies in particular to the reservoir species HONO and H2O2.

  1. Orbit Control of Fly-around Satellite with Highly Eccentric Orbit Using Solar Radiation Pressure

    Science.gov (United States)

    Yong-gang, Hou; Chang-yin, Zhao; Ming-jiang, Zhang; Rong-yu, Sun

    2017-01-01

    The method of controlling highly eccentric accompanying flight orbit using the solar wing is proposed in this paper. The formation is maintained by controlling the orbit of the accompanying satellite (follower). The accompanying satellite rotates around its inertial principal axis with a constant angular velocity. The control on the accompanying satellite is divided into the in-plane control and out-of-plane control. The in-plane control is superior to the out-of-plane control. The out-of-plane control force is applied when the in-plane error is eliminated or the in-plane control force can not be supplied due to some geometrical factors. By the sliding mode control method, the magnitude and direction of the control force required by the in-plane orbit control are calculated. Then accordingly, the expression of the solar wing orientation with respect to the satellite body in the control process is derived, so that by adjusting the orientation of the solar wing, the required control force can be obtained. Finally, the verification on this method is performed by numerical simulations, including the orbit adjustment, error elimination, and the orbit maintenance. It is shown that this method can keep the error less than 5 m, and it is feasible for the space formation flight.

  2. SYNTHESIS AND CHARACTERIZATION OF HIGH BELITE SULFOALUMINATE CEMENT THROUGH RICH ALUMINA FLY ASH AND DESULFURIZATION GYPSUM

    Directory of Open Access Journals (Sweden)

    BING MA,

    2013-03-01

    Full Text Available The objective of this study was the preparation and characterization of high belite sulfoaluminate cement (HBSC from industrial residues. HBSC promises eco-friendly building materials with great mechanical performance at earlier ages than Ordinary Portland Cement (OPC. Preliminary results show the formation of main phase dicalcium silicate (C2S and ye’elimite (C4A3$ at 1250°C, as determined by X-ray diffraction (XRD, are promising. The formation of minerals in the clinker was analyzed by differential scanning calorimetry-thermogravimetry (DSC–TG. Likewise, Scanning electron microscope (SEM and XRD were used to carry out the analysis of the micro-structural and hydration products. The main HBSC hydration products, Ettringite and amorphous Al(OH3, were formed in the early stages; however, during the later stages, monosulfate and Strätlingite were formed. Isothermal conduction calorimetry measurements indicate that hydration properties of the cements are comparable to OPC; the total hydration heat after 3 days was 438 J/g. The optimum compressive strength values of the mortars after 1-, 3-, 7-, and 28-days were 24.9 MPa, 33.2 MPa, 35.6 MPa and 52.8 MPa which can meet the requirement of special structures.

  3. Earthworm populations of highly metal-contaminated soils restored by fly ash-aided phytostabilisation.

    Science.gov (United States)

    Grumiaux, Fabien; Demuynck, Sylvain; Pernin, Céline; Leprêtre, Alain

    2015-03-01

    Highly metal contaminated soils found in the North of France are the result of intense industrial past. These soils are now unfit for the cultivation of agricultural products for human consumption. Solutions have to be found to improve the quality of these soils, and especially to reduce the availability of trace elements (TEs). Phytostabilisation and ash-aided phytostabilisation applied since 2000 to an experimental site located near a former metallurgical site (Metaleurop-Nord) was shown previously as efficacious in reducing TEs mobility in soils. The aim of the study was to check whether this ten years trial had influenced earthworm communities. This experimental site was compared to plots located in the surroundings and differing by the use of soils. Main results are that: (1) whatever the use of soils, earthworm communities are composed of few species with moderate abundance in comparison with communities found in similar habitats outside the TEs-contaminated area, (2) the highest abundance and specific richness (4-5 species) were observed in afforested plots with various tree species, (3) ash amendments in afforested plots did not increase the species richness and modified the communities favoring anecic worms but disfavoring epigeic ones. These findings raised the questions of when and how to perform the addition of ashes firstly, to avoid negative effects on soil fauna and secondly, to keep positive effects on metal immobilization.

  4. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2013-01-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  5. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2012-05-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  6. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett [Park City, UT

    2012-05-15

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  7. Coupled-Mode Flutter of Bending-Bending Type in Highly-Flexible Uniform Airfoils

    Science.gov (United States)

    Pourazarm, Pariya; Modarres-Sadeghi, Yahya

    2016-11-01

    We study the behavior of a highly flexible uniform airfoil placed in wind both numerically and experimentally. It is shown that for a non-rotating highly-flexible cantilevered airfoil, placed at very small angles of attack (less than 1 degree), the airfoil loses its stability by buckling. For slightly higher angles of attack (more than 1 degree) a coupled-mode flutter in which the first and the second flapwise modes coalesce toward a flutter mode is observed, and thus the observed flutter has a bending-bending nature. The flutter onset and frequency found experimentally matched the numerical predictions. If the same airfoil is forced to rotate about its fixed end, the static deflection decreases and the observed couple-mode flutter becomes of flapwise-torsional type, same as what has already been observed for flutter of rotating wind turbine blades. The support provided by the National Science Foundation, CBET-1437988, is greatly acknowledged.

  8. Effect of Fly Ash on the Electrical Conductivity of Concretes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The fly ash occasionally has high content of iron oxide and carbon that are good electrical conducting components. This paper investigates the effect of the fly ash used as mineral admixtures on the electrical conductivity of concretes. The electrical properties of concretes using 3 kinds of fly ash with different iron oxide contents have been studied. Experimental results show that at the same fly ash dosage the resistivity of concrete using fly ash with high content of iron oxide is slightly lower than that with low content of iron oxide. However, the concrete resistivity after 14d increases as fly ash dosage increases regardless of iron oxide content in fly ash.

  9. High-Flying Telescope

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Scientists at the Space Telescope Science Institute,which operates the Hubble Space Telescope,have proposed a new telescope that would have twice the resolution of Hubble at about one-tenth the cost. It would hover seven miles above Earth,dangling below a football-field-size helium balloon

  10. Model order reduction for steady aerodynamics of high-lift configurations

    DEFF Research Database (Denmark)

    Vendl, Alexander; Faßbender, Heike; Goertz, Stefan

    2014-01-01

    In aerodynamic applications, many model reduction methods use proper orthogonal decomposition (POD). In this work, a POD-based method, called missing point estimation (MPE), is modified and applied to steady-state flows with variation of the angle of attack. The main idea of MPE is to select a su......-element high-lift airfoils, one which is normally adopted during landing and the other during take-off....

  11. An Experimntal Investigation of the 30P30N Multi-Element High-Lift Airfoil

    Science.gov (United States)

    Pascioni, Kyle A.; Cattafesta, Louis N.; Choudhari, Meelan M.

    2014-01-01

    High-lift devices often generate an unsteady flow field producing both broadband and tonal noise which radiates from the aircraft. In particular, the leading edge slat is often a dominant contributor to the noise signature. An experimental study of a simplified unswept high-lift configuration, the 30P30N, has been conducted to understand and identify the various flow-induced noise sources around the slat. Closed-wall wind tunnel tests are performed in the Florida State Aeroacoustic Tunnel (FSAT) to characterize the slat cove flow field using a combination of surface and off-body measurements. Mean surface pressures compare well with numerical predictions for the free-air configuration. Consistent with previous measurements and computations for 2D high-lift configurations, the frequency spectra of unsteady surface pressures on the slat surface display several narrowband peaks that decrease in strength as the angle of attack is increased. At positive angles of attack, there are four prominent peaks. The three higher frequency peaks correspond, approximately, to a harmonic sequence related to a feedback resonance involving unstable disturbances in the slat cove shear layer. The Strouhal numbers associated with these three peaks are nearly insensitive to the range of flow speeds (41-58 m/s) and the angles of attack tested (3-8.5 degrees). The first narrow-band peak has an order of magnitude lower frequency than the remaining peaks and displays noticeable sensitivity to the angle of attack. Stereoscopic particle image velocimetry (SPIV) measurements provide supplementary information about the shear layer characteristics and turbulence statistics that may be used for validating numerical simulations.

  12. Wolbachia association with the tsetse fly, Glossina fuscipes fuscipes, reveals high levels of genetic diversity and complex evolutionary dynamics

    Directory of Open Access Journals (Sweden)

    Symula Rebecca E

    2013-02-01

    Full Text Available Abstract Background Wolbachia pipientis, a diverse group of α-proteobacteria, can alter arthropod host reproduction and confer a reproductive advantage to Wolbachia-infected females (cytoplasmic incompatibility (CI. This advantage can alter host population genetics because Wolbachia-infected females produce more offspring with their own mitochondrial DNA (mtDNA haplotypes than uninfected females. Thus, these host haplotypes become common or fixed (selective sweep. Although simulations suggest that for a CI-mediated sweep to occur, there must be a transient phase with repeated initial infections of multiple individual hosts by different Wolbachia strains, this has not been observed empirically. Wolbachia has been found in the tsetse fly, Glossina fuscipes fuscipes, but it is not limited to a single host haplotype, suggesting that CI did not impact its population structure. However, host population genetic differentiation could have been generated if multiple Wolbachia strains interacted in some populations. Here, we investigated Wolbachia genetic variation in G. f. fuscipes populations of known host genetic composition in Uganda. We tested for the presence of multiple Wolbachia strains using Multi-Locus Sequence Typing (MLST and for an association between geographic region and host mtDNA haplotype using Wolbachia DNA sequence from a variable locus, groEL (heat shock protein 60. Results MLST demonstrated that some G. f. fuscipes carry Wolbachia strains from two lineages. GroEL revealed high levels of sequence diversity within and between individuals (Haplotype diversity = 0.945. We found Wolbachia associated with 26 host mtDNA haplotypes, an unprecedented result. We observed a geographical association of one Wolbachia lineage with southern host mtDNA haplotypes, but it was non-significant (p = 0.16. Though most Wolbachia-infected host haplotypes were those found in the contact region between host mtDNA groups, this association was non

  13. Catalytic oxidation of Methyl Orange by an amorphous FeOOH catalyst developed from a high iron-containing fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Yi Li; Fu-Shen Zhang [Chinese Academy of Sciences, Beijing (China). Research Center for Eco-Environmental Sciences

    2010-04-15

    Heterogeneous photo-Fenton process using an amorphous FeOOH as catalyst was studied to degrade Methyl Orange (MO) dye in aqueous solution. The amorphous FeOOH was prepared by dissolution and precipitation using a high iron-containing fly ash as raw material. The ash not only provided iron source but also acted as a supporter of amorphous FeOOH. Coating the fly ash particles with the amorphous FeOOH significantly enhanced the removal of MO, and 2.5 g of catalyst was sufficient to degrade 50 mg MO from 1 l of aqueous solution at pH 7.0 after 80 min. Oxidant concentration, solution pH, UV/dark/sunlight and recycling of the catalyst were investigated in order to evaluate the photo-Fenton effects. Moreover, variations of particle size before and after preparation, separation of solid-liquid and stability of the amorphous FeOOH in the catalyst were studied. It was testified that the amorphous FeOOH on the surface of fly ash was stable and the Fenton catalyst was easily separated from the aqueous system.

  14. High-Alfa Aerodynamics with Separated Flow Modeled as a Single Nascent Vortex

    Science.gov (United States)

    Antony, Samuel B.; Mukherjee, Rinku

    2017-04-01

    A numerical iterative vortex lattice method is developed to study flow past wing(s) at high angles of attack where the separated flow is modelled using NY nascent vortex filaments. The wing itself is modelled using NX × NY bound vortex rings, where NX and NY are the number of sections along the chord and span of the wing respectively. The strength and position of the nascent vortex along the chord corresponding to the local effective angle of attack are evaluated from the residuals in viscous and potential flow, i.e. (Cl)visc - (Cl)pot and (Cm)visc - (Cm)pot. Hence, the 2D airfoil viscous Cl - α and Cm - α is required as input (from experiment, numerical analysis or CFD). Aerodynamic characteristics and section distribution along span are predicted for 3D wings at a high angle of attack. Effect of initial conditions and existence of multiple solutions in the post-stall region is studied. Results are validated with experiment.

  15. 带升力风扇飞翼布局飞机机翼开口处二维气动特性研究%Two-dimensional Aerodynamics Characteristics Study on Lift-fan Aircraft Openings in Flying Wing Configuration

    Institute of Scientific and Technical Information of China (English)

    林玉祥; 王琦; 李卫; 杜琪

    2015-01-01

    The lift-fan aircraft in flying wing configuration not only can be capable of short distance/vertical takeoff and landing ( S/VTOL) ,but also have the aerodynamics advantages of the flying wing. In order to obtain the effect laws of the opening on the aerodynamic characteristics of the wing,the aerodynamics performance of the longitudinal center section of wing opening is studied by the aerodynamic simulation in horizontal flight. Moreover, the characteristics of lift coefficient,drag coefficient and moment coefficient changing with the change of flow velocity and angle of attack are also analyzed. The study shows that under the same angle of attack, with the increase of flow velocity,drag coefficient and moment coefficient are risen. Under the same flow velocity, with the increase of angle of attack,the lift coefficient is increased,the drag coefficient is decreased first and then increased,the moment coefficient is decreased, and always produce nose-down moment. The study results provide a basis for the further optimization of the opening position and shape.%带升力风扇飞翼布局飞机不仅可实现垂直/短距起降,还拥有飞翼布局飞机的气动优点. 为获得开口对机翼气动特性的影响规律,对平飞状态下机翼开口中心处的纵向剖面进行气动仿真,分析升力系数、阻力系数和力矩系数随来流速度和迎角的改变而变化的特性. 结果表明:在迎角一定的情况下,随着来流速度的增大,阻力系数和力矩系数呈上升趋势;来流速度一定时,随迎角加大,升力系数增大,阻力系数先减小后增大;力矩系数随之减小,且一直都产生低头力矩. 研究结果对开口位置和形状的进一步优化提供了依据.

  16. Speeding-up the computation of high-lift aerodynamics using a residual-based reduced-order model

    DEFF Research Database (Denmark)

    Mifsud, M.; Zimmermann, R.; Goertz, Stefan

    2014-01-01

    In this article, we propose a strategy for speeding-up the computation of the aerodynamics of industrial high-lift configurations using a residual-based reduced-order model (ROM). The ROM is based on the proper orthogonal decomposition (POD) of a set of solutions to the Navier–Stokes equations...... is augmented with the latest CFD computed flow solution. Using this strategy, a considerable reduction in the total number of iterations to reach the converged steady-state solution is achieved when compared with conventional computational techniques used in industry for a series of computations such as drag...... governing fluid flow at different parameter values, from which a set of orthogonal basis vectors is evaluated. By considering an initial set of few snapshots at different angles of attack, a ROM is constructed which is used to predict a solution at an angle of attack which is just outside the space spanned...

  17. Abundances and distribution of minerals and elements in high-alumina coal fly ash from the Jungar Power Plant, Inner Mongolia, China

    Science.gov (United States)

    Dai, S.; Zhao, L.; Peng, S.; Chou, C.-L.; Wang, X.; Zhang, Y.; Li, D.; Sun, Y.

    2010-01-01

    The fly ash from the Jungar Power Plant, Inner Mongolia, China, is unique because it is highly enriched in alumina (Al2O3>50%). The fly ash mainly consists of amorphous glass and mullite and trace amounts of corundum, quartz, char, calcite, K-feldspar, clay minerals, and Fe-bearing minerals. The mullite content in fly ash is as high as 37.4% because of high boehmite and kaolinite contents in feed coal. Corundum is a characteristic mineral formed during the combustion of boehmite-rich coal.Samples from the economizer were sieved into six size fractions (500 mesh) and separated into magnetic, mullite+corundum+quartz (MCQ) and glass phases for mineralogical and chemical analysis. The corundum content increases but amorphous glass decreases with decreasing particle size. Fractions of small particle sizes are relatively high in mullite, probably because mullite was formed from fine clay mineral particles under high-temperature combustion condition. Similarly, fine corundum crystals formed in the boiler from boehmite in feed coal. The magnetic phase consists of hematite, magnetite, magnesioferrite, and MgFeAlO4 crystals. The MCQ phase is composed of 89% mullite, 6.1% corundum, 4.5% quartz, and 0.5% K-feldspar.Overall, the fly ash from the power plant is significantly enriched in Al2O3 with an average of 51.9%, but poor in SiO2, Fe2O3, CaO, MgO, Na2O, P2O5, and As. Arsenic, TiO2, Th, Al2O3, Bi, La, Ga, Ni, and V are high in mullite, and the magnetic matter is enriched in Fe2O3, CaO, MnO, TiO2, Cs, Co, As, Cd, Ba, Ni, Sb, MgO, Zn, and V. The remaining elements are high in the glass fraction. The concentration of K2O, Na2O, P2O5, Nb, Cr, Ta, U, W, Rb, and Ni do not clearly vary with particle size, while SiO2 and Hg decrease and the remaining elements clearly increase with decreasing particle size. ?? 2009 Elsevier B.V.

  18. Estimating Orientation of Flying Fruit Flies.

    Directory of Open Access Journals (Sweden)

    Xi En Cheng

    Full Text Available The recently growing interest in studying flight behaviours of fruit flies, Drosophila melanogaster, has highlighted the need for developing tools that acquire quantitative motion data. Despite recent advance of video tracking systems, acquiring a flying fly's orientation remains a challenge for these tools. In this paper, we present a novel method for estimating individual flying fly's orientation using image cues. Thanks to the line reconstruction algorithm in computer vision field, this work can thereby focus on the practical detail of implementation and evaluation of the orientation estimation algorithm. The orientation estimation algorithm can be incorporated into tracking algorithms. We rigorously evaluated the effectiveness and accuracy of the proposed algorithm by running experiments both on simulation data and on real-world data. This work complements methods for studying the fruit fly's flight behaviours in a three-dimensional environment.

  19. Flying insects and Campylobacter

    DEFF Research Database (Denmark)

    Hald, Birthe; Sommer, Helle Mølgaard; Skovgård, Henrik

    Campylobacter in flies Flies of the Muscidae family forage on all kind of faeces – various fly species have different preferences. M domestica prefer pigs, horses and cattle faeces, animals which are all known to frequently excrete Campylobacter. As a result, the insects pick up pathogenic micro...... organisms, which may collect on their bodies or survive passage through the fly gut. Campylobacter and other pathogens are then easily transferred to other surfaces, for instance peoples food – or to broiler houses where they may be swallowed by chickens or contaminate the environment. On a large material...... of several species of flies collected outside broiler houses, merely ~1% of the flies were found Campylobacter positive. However, the prevalence varied considerably with fly species, time of the year, and availability of Campylobacter sources. Influx of flies to broiler houses As the influx of flies...

  20. Flying insects and Campylobacter

    DEFF Research Database (Denmark)

    Hald, Birthe; Sommer, Helle Mølgaard; Skovgård, Henrik

    to broiler houses may be counted in thousands per broiler rotation during summer periods, even a low prevalence of Campylobacter positive flies constitute a risk of introduction of Campylobacter to the chickens. M. domestica – the house fly is the most important vector fly for Campylobacter transmission...... organisms, which may collect on their bodies or survive passage through the fly gut. Campylobacter and other pathogens are then easily transferred to other surfaces, for instance peoples food – or to broiler houses where they may be swallowed by chickens or contaminate the environment. On a large material...... of several species of flies collected outside broiler houses, merely ~1% of the flies were found Campylobacter positive. However, the prevalence varied considerably with fly species, time of the year, and availability of Campylobacter sources. Influx of flies to broiler houses As the influx of flies...

  1. Identifying glass compositions in fly ash

    Directory of Open Access Journals (Sweden)

    Katherine eAughenbaugh

    2016-01-01

    Full Text Available In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS, calcium aluminosilicate glasses (CAS, a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

  2. Aerodynamic Characteristics of Three Deep-Stepped Planing-Tail Flying-Boat Hulls

    Science.gov (United States)

    Riebe, John M.; Naeseth, Rodger L.

    1947-01-01

    An investigation was made in the Langley 300 MPH 7- by 10-foot tunnel to determine the aerodynamic characteristics of three deep-stepped planing-tail flying-boat hulls differing only in the amount of step fairing. The hulls were derived by increasing the unfaired step depth of a planing-tail hull of a previous aerodynamic investigation to a depth about 92 percent of the hull beam. Tests were also made on a transverse-stepped hull with an extended afterbody for the purpose of comparison and in order to extend and verify the results of a previous investigation. The investigation indicated that the extended afterbody hull had a minimum drag coefficient about the same as a conventional hull, 0.0066, and an angle-of-attack range for minimum drag coefficient of 0.0057 which was 14 percent less than the transverse stepped hull with extended afterbody; the hulls with step fairing had up to 44 percent less minimum drag coefficient than the transverse-stepped hull, or slightly more drag than a streamlined body having approximately the same length and volume. Longitudinal and lateral instability varied little with step fairing and was about the same as a conventional hull.

  3. Use of a Viscous Flow Simulation Code for Static Aeroelastic Analysis of a Wing at High-Lift Conditions

    Science.gov (United States)

    Akaydin, H. Dogus; Moini-Yekta, Shayan; Housman, Jeffrey A.; Nguyen, Nhan

    2015-01-01

    In this paper, we present a static aeroelastic analysis of a wind tunnel test model of a wing in high-lift configuration using a viscous flow simulation code. The model wing was tailored to deform during the tests by amounts similar to a composite airliner wing in highlift conditions. This required use of a viscous flow analysis to predict the lift coefficient of the deformed wing accurately. We thus utilized an existing static aeroelastic analysis framework that involves an inviscid flow code (Cart3d) to predict the deformed shape of the wing, then utilized a viscous flow code (Overflow) to compute the aerodynamic loads on the deformed wing. This way, we reduced the cost of flow simulations needed for this analysis while still being able to predict the aerodynamic forces with reasonable accuracy. Our results suggest that the lift of the deformed wing may be higher or lower than that of the non-deformed wing, and the washout deformation of the wing is the key factor that changes the lift of the deformed wing in two distinct ways: while it decreases the lift at low to moderate angles of attack simply by lowering local angles of attack along the span, it increases the lift at high angles of attack by alleviating separation.

  4. Orientation cues for high-flying nocturnal insect migrants: do turbulence-induced temperature and velocity fluctuations indicate the mean wind flow?

    Directory of Open Access Journals (Sweden)

    Andy M Reynolds

    Full Text Available Migratory insects flying at high altitude at night often show a degree of common alignment, sometimes with quite small angular dispersions around the mean. The observed orientation directions are often close to the downwind direction and this would seemingly be adaptive in that large insects could add their self-propelled speed to the wind speed, thus maximising their displacement in a given time. There are increasing indications that high-altitude orientation may be maintained by some intrinsic property of the wind rather than by visual perception of relative ground movement. Therefore, we first examined whether migrating insects could deduce the mean wind direction from the turbulent fluctuations in temperature. Within the atmospheric boundary-layer, temperature records show characteristic ramp-cliff structures, and insects flying downwind would move through these ramps whilst those flying crosswind would not. However, analysis of vertical-looking radar data on the common orientations of nocturnally migrating insects in the UK produced no evidence that the migrants actually use temperature ramps as orientation cues. This suggests that insects rely on turbulent velocity and acceleration cues, and refocuses attention on how these can be detected, especially as small-scale turbulence is usually held to be directionally invariant (isotropic. In the second part of the paper we present a theoretical analysis and simulations showing that velocity fluctuations and accelerations felt by an insect are predicted to be anisotropic even when the small-scale turbulence (measured at a fixed point or along the trajectory of a fluid-particle is isotropic. Our results thus provide further evidence that insects do indeed use turbulent velocity and acceleration cues as indicators of the mean wind direction.

  5. Computational Fluid Dynamic Analyses for the High-Lift Common Research Model Using the USM3D and FUN3D Flow Solvers

    Science.gov (United States)

    Rivers, Melissa; Hunter, Craig; Vatsa, Veer

    2017-01-01

    Two Navier-Stokes codes were used to compute flow over the High-Lift Common Research Model (HL-CRM) in preparation for a wind tunnel test to be performed at the NASA Langley Research Center 14-by-22-Foot Subsonic Tunnel in fiscal year 2018. Both flight and wind tunnel conditions were simulated by the two codes at set Mach numbers and Reynolds numbers over a full angle-of-attack range for three configurations: cruise, landing and takeoff. Force curves, drag polars and surface pressure contour comparisons are shown for the two codes. The lift and drag curves compare well for the cruise configuration up to 10deg angle of attack but not as well for the other two configurations. The drag polars compare reasonably well for all three configurations. The surface pressure contours compare well for some of the conditions modeled but not as well for others.

  6. Effect of V2O5 on the properties of mullite ceramics synthesized from high-aluminum fly ash and bauxite.

    Science.gov (United States)

    Li, Jin-Hong; Ma, Hong-Wen; Huang, Wen-Hui

    2009-07-30

    In this communication, high-strength mullite ceramics was prepared from bauxite and high-aluminum fly ash that is a by-product of coal combustion in thermal power plants. The effects of the doping V(2)O(5) on the bulk density, apparent porosity, bending strength and microstructure of mullite ceramics were studied in detail. It was indicated that 5-10 mol% V(2)O(5) reduced the sintering temperature by 50 degrees C. The apparent porosity and water absorption of the mullite ceramics decreased with increasing V(2)O(5) content. Mullite ceramics with bending strength as high as 108 MPa were obtained at 1500 degrees C with the addition of 10 mol% V(2)O(5). X-ray diffraction analysis suggested that the prepared ceramics was mainly in phase of mullite, and scanning electron microscope images confirmed that it mostly existed in the shape of a long parallelepiped. This research may provide a new method in utilizing the vast resources of fly-ash waste from power plants in the production of low-cost mullite-based engineering materials.

  7. Flying qualities criteria and flight control design

    Science.gov (United States)

    Berry, D. T.

    1981-01-01

    Despite the application of sophisticated design methodology, newly introduced aircraft continue to suffer from basic flying qualities deficiencies. Two recent meetings, the DOD/NASA Workshop on Highly Augmented Aircraft Criteria and the NASA Dryden Flight Research Center/Air Force Flight Test Center/AIAA Pilot Induced Oscillation Workshop, addressed this problem. An overview of these meetings is provided from the point of view of the relationship between flying qualities criteria and flight control system design. Among the items discussed are flying qualities criteria development, the role of simulation, and communication between flying qualities specialists and control system designers.

  8. Ⅱ级灰对配制大掺量粉煤灰混凝土的性能影响%THE EFFECT OF THE Ⅱ GRADE FLY ASH ON PREPAREING HIGH-VOLUME FLY ASH CONCRETE

    Institute of Scientific and Technical Information of China (English)

    余丽武; 吴志平; 吴志强

    2009-01-01

    采用微观分析技术,研究了江西省当地产的Ⅱ级粉煤灰的性状,并选用当地典型原材料,采用超量取代的方法,选取5种不同掺量的粉煤灰,配制中等强度的大掺量粉煤灰混凝土(High Fly-ash ContentConcrete,简称HFCC),综合分析和探讨了大掺量粉煤灰混凝土的力学性能和耐久性.结果表明,与普通混凝土相比,采用江西省Ⅱ级灰配制的大掺量粉煤灰混凝土后期强度增幅显著,56d强度甚至能超过普通混凝土,弹性模量-强度比和抗渗性均高于普通混凝土,而抗冻性和抗碳化能力均有所下降.

  9. Physicochemical characterization of Spanish fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Querol, X.; Umana, J.C.; Alastuey, A.; Bertrana, C.; Lopez-Soler, A.; Plana, F.

    1999-12-01

    This article summarizes the results obtained from the physical, chemical, and mineralogical characterization of 14 fly ash samples. Major features that influence the utilization of each fly ash for zeolite synthesis are evidenced, and several fly ash types were selected as potential high-quality starting material for zeolite synthesis and ceramic applications. The main parameters influencing this selection were relatively small grain size; high Al and Si contents; high glass content; low CaO, S, and Fe contents; and relatively low heavy metal concentration. The Compostilla and Cou He fly ashes have high potential applications because of the low content of major impurities (such as Ca, Fe, and S) and the low content of soluble hazardous elements. The Espiel, Escucha, Los Barrios, As Pontes, Soto de Ribera, Meirama, Narcea, and Teruel fly ashes have important application potential, but this potential is slightly limited by the intermediate content of nonreactive impurities, such as Fe and Ca. The La Robla fly ash is of moderate interest, since the relatively high Ca and Fe oxide contents may reduce its potential applications. Finally, the Puertollano fly ash also has limited application because of the very high concentration of some heavy metals such as As, Cd, Ge, Hg, Pb, and Zn. From a mineralogical point of view, the Compostilla, Espiel, and Soto de Ribera fly ashes show the highest aluminum-silicate glass content and, consequently, the highest industrial application potential.

  10. Physiochemical characterization of Spanish fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Querol, X.; Umana, J.C.; Alastuey, A.; Bertrana, C.; Lopez Soler, A.; Plana, F.

    1999-12-01

    This article summarizes the results obtained from the physical, chemical, and mineralogical characterization of 14 fly ash samples. Major features that influence the utilization of each fly ash for zeolite synthesis are evidenced, and several fly ash types were selected as potential high-quality starting material for zeolite synthesis and ceramic applications. The main parameters influencing this selection were relatively small grain size; high Al and Si contents; high glass content; low CaO, S, and Fe contents; and relatively low heavy metal concentration. The Compostilla and Dou He fly ashes have high potential applications because of the low content of major impurities (such as Ca, Fe, and S) and the low content of soluble hazardous elements. The Espiel, Escucha, Los Barrios, As Pontes, Soto de Ribera, Meirama, Narcea, and Teruel fly ashes have important application potential, but this potential is slightly limited by the intermediate content of nonreactive impurities, such as Fe and Ca. The La Robla fly ash is of moderate interest, since the relatively high Ca and Fe oxide contents may reduce its potential applications. Finally, the Puertollano fly ash also has limited application because of the very high concentration of some heavy metals such as As, Cd, Ge, Hg, Pb, and Zn. From a mineralogical point of view, the Compostilla, Espiel, and Soto de Ribera fly ashes show the highest aluminum-silicate glass content and, consequently, the highest industrial application potential. (author)

  11. Wind tunnel studies of turns by flying dragonflies.

    Science.gov (United States)

    Alexander, D E

    1986-05-01

    High-speed movies of dragonflies turning in flight on flexible tethers show that there are two distinct modes of turning. In the 'conventional' mode, dragonflies use left-right asymmetries in the wing stroke amplitude, and occasionally in the angle of attack, to produce more lift and thrust on one side than the other. This causes the animal to roll into a bank, so that the lift vector has a sideward component; this sideward component produces the turn, much as in an airplane. This type of turn is probably most useful during fast forward flight. The second mode of turning in the 'yaw turn'. Yaw turns are accomplished without banking, and the dragonfly's long axis may turn more than 90 degrees in the period of two wing strokes. The kinematics of this turn could not be as closely analysed, but it appears that dragonflies use drag on the inner wing upstroke and the outer wing downstroke to turn, much like pivoting a rowing boat. This turn may be hampered by drag on the abdomen during fast forward flight and would be most useful at low speeds or during hovering.

  12. Possibilities of utilizing power plant fly ashes

    Directory of Open Access Journals (Sweden)

    Mezencevová Andrea

    2003-09-01

    mechanical action. It is known, that performance of fly ash in concrete improves with its increased fineness. Intensive milling of fly ash leads to the increasing fly ash fineness and to the enhancement of its hydration activity. The cement-fly ash composites with 25 wt.% of activated fly ash as cement replacement have exhibited a higher 28-day compressive strength in comparison with a reference concrete sample without fly ash. An unfavorable effect in milling process is the agglomeration of fine particles of fly ash. By high-energy milling of fly ash with addition of surfactants, the ultrafine products can be prepared. Concrete samples containing such fly ash have achieved higher compressive strengths than the reference sample without fly ash or with addition of non-milled fly ash. The considerable physical effect of ultrafine fly ash consists in superior filling of spaces between coarser cement particles and in the favorable influence of hardness of the mixtures at setting.The current research activities in mechanochemistry are oriented to the mechanical activation of poly-component systems. The knowledge in this field indicate that by high-energy milling of fly ash as a poly-component system and following heating of prepared metastable precursors, the cement minerals could be prepared.

  13. Use Of Fly Iarvae In Space Agriculture

    Science.gov (United States)

    Katayama, Naomi; Mitsuhashi, Jun; Hachiya, Natumi; Miyashita, Sachiko; Hotta, Atuko

    The concept of space agriculture is full use of biological and ecological components ot drive materials recycle loop. In an ecological system, producers, consumers and decomposers are its member. At limited resources acailable for space agriculture, full use of members' function is required to avoid food shortage and catastrophe.Fly is categrized to a decomposer at its eating excreta and rotten materials. However, is it could be edible, certainly it is eaten in several food culture of the world, it functions as a converter of inedible biomass ot edible substance. This conversion enhances the efficiency of usage of resource that will be attributed to space agriculture. In this context, we examine the value of melon fly, Dacus cucurbitae, as a candidate fly species ofr human food. Nutrients in 100g of melon fly larvae were protein 12g, lipid 4.6g Fe 4.74mg, Ca 275mg, Zn 6.37mg, Mn 4.00mg. Amino acids compositon in 100g of larvae was glutamic acid 1.43g and aspartic acid 1.12g. Because of high contents of these amino acids taste of fly larva might be good. Life time of adult melon fly is one to two month, and lays more than 1,000 eggs in total during the life. Larvae hatch after one to two days, and metamorphose after 8 to 15 days to pupae. Srxual maturity is reached after 22 days the earliest from it egg. Sixteen generations could be succeeded in a year for melon fly at maximum. The rate of proliferation of fly is quite high compared to silkworm that can have 8.7 generations per year. The wide food habit of fly, compared to mulberry leaf for silkworm, is another advantage to choose fly for entomophage. Rearing technology of melon fly is well established, since large scaled production of sterile male fly has been conducted in order ot exterminate melon fly in the field. Feeding substance for melon fly larvae in production line is a mixture of wheat, bran, raw sugar, olara, beer yeast, tissue paper, and additive chemicals. A 1 kg of feed substance can be converted to

  14. High performance forward swept wing aircraft

    Science.gov (United States)

    Koenig, David G. (Inventor); Aoyagi, Kiyoshi (Inventor); Dudley, Michael R. (Inventor); Schmidt, Susan B. (Inventor)

    1988-01-01

    A high performance aircraft capable of subsonic, transonic and supersonic speeds employs a forward swept wing planform and at least one first and second solution ejector located on the inboard section of the wing. A high degree of flow control on the inboard sections of the wing is achieved along with improved maneuverability and control of pitch, roll and yaw. Lift loss is delayed to higher angles of attack than in conventional aircraft. In one embodiment the ejectors may be advantageously positioned spanwise on the wing while the ductwork is kept to a minimum.

  15. 高强度等级粉煤灰水泥的试验研究%Experimental Rresearch on Fly Ash Cement Which Meet High Strength

    Institute of Scientific and Technical Information of China (English)

    易龙生; 齐莉娜; 李来顺; 冯泽平; 毛齐

    2015-01-01

    通过机械粉磨、化学药剂复合激发粉煤灰的活性,制得了粉煤灰掺量达50%的高掺量粉煤灰水泥。试验结果表明:最佳粉磨时间为30 min,激发剂选用NaOH。在粉煤灰、熟料、石膏与激发剂配比为50∶44∶5∶1下,制得的高掺量粉煤灰水泥强度达到52.5R等级,且各项性能均满足普通硅酸盐水泥的技术标准。%Through mechanical grinding and chemical excitation to stimulate the activity of lfy ash, the study prepared high volume lfy ash cement,which lfy ash prepared up to 50%. The results showed that:the optimum experiment conditions is that grinding for 30 min, the activator takes NaOH. The mix proportion is m(fly ash)∶m(clinker)∶m(plaster)∶m(activator)=50∶44∶5∶1, it prepared large volume fly ash cement which strength grade can reach 52.5R, and it meet the standard of portland cement.

  16. Research on Desilicating Process from High Aluminium Fly Ash%高铝粉煤灰脱硅反应的研究

    Institute of Scientific and Technical Information of China (English)

    宋说讲; 孔德顺

    2013-01-01

      Desilicating process of soluble sinlicon from high aluminium fly ash in certain concentration sodium hydroxide was re-searched with investagation of concentration of sodium hydroxide, temperature, time and solid content. The result showed that the optimization conditions were:concentration of sodium hydroxide 150g/L, temperature 120℃, time 30min and solid content 350g/L. Alumina silica ratio of desiliconized fly ash increased to more than 1.80.%  采用一定浓度的氢氧化钠溶液与高铝粉煤灰中可溶性二氧化硅进行反应,考察苛碱浓度、反应温度、反应时间、浆液固含条件对脱硅反应的影响。结果表明,脱硅反应的优化条件为苛碱浓度150g·L-1,温度120℃,反应时间30min,固含量350g·L-1,脱硅粉煤灰铝硅比由1.20提高到1.80以上。

  17. Power reduction and the radial limit of stall delay in revolving wings of different aspect ratio

    NARCIS (Netherlands)

    Kruyt, J.W.; Heijst, Van G.F.; Altshuler, D.L.; Lentink, David

    2015-01-01

    Airplanes and helicopters use high aspect ratio wings to reduce the power required to fly, but must operate at low angle of attack to prevent flow separation and stall. Animals capable of slow sustained flight, such as hummingbirds, have low aspect ratio wings and flap their wings at high angle o

  18. Power reduction and the radial limit of stall delay in revolving wings of different aspect ratio

    NARCIS (Netherlands)

    Kruyt, J.W.; Heijst, Van G.F.; Altshuler, D.L.; Lentink, David

    2015-01-01

    Airplanes and helicopters use high aspect ratio wings to reduce the power required to fly, but must operate at low angle of attack to prevent flow separation and stall. Animals capable of slow sustained flight, such as hummingbirds, have low aspect ratio wings and flap their wings at high angle o

  19. Flying Thoughts

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    ON a boundless stretch of wilderness, weeds sway in the breeze and riotous clouds float against the dark distant horizon. It seems that I am not myself. I feel as if I am the breeze sweeping the treetops, or the grasses being swayed. I feel I have mingled myself with the earth and the sky; my mind, like an eagle, soars up into the high heavens, roams through the universe and then disappears into the immense cosmos. I feel

  20. Influence of fly ash aided phytostabilisation of Pb, Cd and Zn highly contaminated soils on Lolium perenne and Trifolium repens metal transfer and physiological stress

    Energy Technology Data Exchange (ETDEWEB)

    Lopareva-Pohu, A.; Verdin, A.; Garcon, G.; Sahraoui, A.L.H.; Pourrut, B.; Debiane, D.; Waterlot, C.; Laruelle, F.; Bidar, G.; Douay, F.; Shirali, P. [University of Lille Nord France, Lille (France)

    2011-06-15

    Due to anthropogenic activities, large extends of soils are highly contaminated by Metal Trace Element (MTE). Aided phytostabilisation aims to establish a vegetation cover in order to promote in situ immobilisation of trace elements by combining the use of metal-tolerant plants and inexpensive mineral or organic soil amendments. Eight years after Coal Fly Ash (CFA) soil amendment, MTE bioavailability and uptake by two plants, Lolium perenne and Trifolium repens, were evaluated, as some biological markers reflecting physiological stress. Results showed that the two plant species under study were suitable to reduce the mobility and the availability of these elements. Moreover, the plant growth was better on CFA amended MTE-contaminated soils, and the plant sensitivity to MTE-induced physiological stress, as studied through photosynthetic pigment contents and oxidative damage was lower or similar. In conclusion, these results supported the usefulness of aided phytostabilisation of MTE-highly contaminated soils.

  1. F-18 high alpha research vehicle surface pressures: Initial in-flight results and correlation with flow visualization and wind-tunnel data

    Science.gov (United States)

    Fisher, David F.; Banks, Daniel W.; Richwine, David M.

    1990-01-01

    Pressure distributions measured on the forebody and the leading-edge extensions (LEX's) of the NASA F-18 high alpha research vehicle (HARV) were reported at 10 and 50 degree angles of attack and at Mach 0.20 to 0.60. The results were correlated with HARV flow visualization and 6-percent scale F-18 wind-tunnel-model test results. The general trend in the data from the forebody was for the maximum suction pressure peaks to first appear at an angle of attack (alpha) of approximately 19 degrees and increase in magnitude with angle of attack. The LEX pressure distribution general trend was the inward progression and increase in magnitude of the maximum suction peaks up to vortex core breakdown and then the decrease and general flattening of the pressure distribution beyond that. No significant effect of Mach number was noted for the forebody results. However, a substantial compressibility effect on the LEX's resulted in a significant reduction in vortex-induced suction pressure as Mach number increased. The forebody primary and the LEX secondary vortex separation lines, from surface flow visualization, correlated well with the end of pressure recovery, leeward and windward, respectively, of maximum suction pressure peaks. The flight to wind-tunnel correlations were generally good with some exceptions.

  2. Catch Composition of Tsetse Flies (Glossina: Glossinidae

    Directory of Open Access Journals (Sweden)

    K. E. Okoh

    2011-01-01

    Full Text Available Problem statement: A study to determine the composition of tsetse flies species was conducted between January and December, 2007 in Kamuku National Park, Nigeria, using Biconical and Nitse traps. Tsetse flies were trapped along gallery forest in five streams for two trapping days and were collected daily. Approach: All tsetse flies caught were identified to species level, sexed, separated into teneral and non-teneral, hunger staged and Mean Hunger Stage computed. Fly density were calculated, the age structure examined using wing fray techniques for males and ovarian technique for females; the reproductive status of female flies were assessed. Two species of tsetse flies (Glossina palpalis palpalis robineau-desvoidy and Glossina tachinoides Westwood were caught in total of five hundred and two (502 flies. Out of these, 309(61.6% Glossina tachinoides and 193(38.4% G. palpalis were caught. Male catches (309, 61.6% were significantly (P Results: The estimated mean age for males was 11 days and females were 8 days. The insemination rate of 93.8% generally was high, G. tachinoides recorded 95.5% more than G. palpalis of 91.6%. Whereas parity rate (25.8% was low; G. palpalis was 37.4% while G. tachinoides parity rate is 17.2%. Conclusion: The study shows that two species of tsetse flies abound in the park although at low densities their presence may bear semblance to Trypanosomiasis and its impact to ecotourism.

  3. Formation Flying Concept Issues

    Directory of Open Access Journals (Sweden)

    M. V. Palkin

    2015-01-01

    Full Text Available The term “formation flying” implies coordinated movement of at least two satellites on coplanar and non-coplanar orbits with a maximum distance between them being much less than the length of the orbit. Peculiarities of formation flying concept also include:- automatic coordination of satellites;- sub-group specialization of formation flying satellites;- equipment and data exchange technology unification in each specialized group or subgroup.Formation flying satellites can be classified according to the configuration stability level (order (array, cluster («swarm», intergroup specialization rules («central satellite», «leader», «slave», manoeuvrability («active» and «passive» satellites.Tasks of formation flying include:- experiments with payload, distributed in formation flying satellites;- various near-earth space and earth-surface research;- super-sized aperture antenna development;- land-based telescope calibration;- «space advertisement» (earth-surface observable satellite compositions of a logotype, word, etc.;- orbital satellite maintenance, etc.Main issues of formation flying satellite system design are:- development of an autonomous satellite group manoeuvring technology;- providing a sufficient characteristic velocity of formation flying satellites;- ballistic and navigation maintenance for satellite formation flying;- technical and economic assessment of formation flying orbital delivery and deployment;- standardization, unification, miniaturization and integration of equipment;- intergroup and intersatellite function redistribution.

  4. 磷高强石膏-粉煤灰-石灰的耐水性研究%Study on Water Resistance of Phosphogypsum Based on High Strength Gypsum-Fly Ash-Lime Materials

    Institute of Scientific and Technical Information of China (English)

    茹晓红; 汤琦; 马保国; 邹开波

    2015-01-01

    将粉煤灰及其激发剂石灰加入到磷石膏制备的高强石膏中制备出水硬性的磷石膏粉煤灰石灰( PGFL)复合胶凝材料。通过对比试验研究了石灰、粉煤灰、磷高强石膏(PGHH)掺量对产品软化系数、抗压强度性能的影响,结果表明:加入适量的粉煤灰、石灰可以显著提高PGFL的后期绝干抗压强度和软化系数,提高材料的耐水性,掺量过多则会带来不利影响。%Phosphogypsum-fly ash-lime cementitous materials ( PGFL) was prepared by phosphogypsum based high strength hemihydrate gypsum ( PGHH) mixed with fly ash and lime. Effects of lime, fly ash and PGHH additions to PGFL properties of compressive strength and softening coefficient were investigated through comparison testing. The results showed that water resistance of PGFL material was improved by long-term dry compressive strength and softening coefficient increased significantly with proper fly ash and lime contents. However, adverse impacts may caused by too much fly ash and lime additions.

  5. The whole genome sequence of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reveals insights into the biology and adaptive evolution of a highly invasive pest species.

    Science.gov (United States)

    Papanicolaou, Alexie; Schetelig, Marc F; Arensburger, Peter; Atkinson, Peter W; Benoit, Joshua B; Bourtzis, Kostas; Castañera, Pedro; Cavanaugh, John P; Chao, Hsu; Childers, Christopher; Curril, Ingrid; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dolan, Amanda; Dugan, Shannon; Friedrich, Markus; Gasperi, Giuliano; Geib, Scott; Georgakilas, Georgios; Gibbs, Richard A; Giers, Sarah D; Gomulski, Ludvik M; González-Guzmán, Miguel; Guillem-Amat, Ana; Han, Yi; Hatzigeorgiou, Artemis G; Hernández-Crespo, Pedro; Hughes, Daniel S T; Jones, Jeffery W; Karagkouni, Dimitra; Koskinioti, Panagiota; Lee, Sandra L; Malacrida, Anna R; Manni, Mosè; Mathiopoulos, Kostas; Meccariello, Angela; Murali, Shwetha C; Murphy, Terence D; Muzny, Donna M; Oberhofer, Georg; Ortego, Félix; Paraskevopoulou, Maria D; Poelchau, Monica; Qu, Jiaxin; Reczko, Martin; Robertson, Hugh M; Rosendale, Andrew J; Rosselot, Andrew E; Saccone, Giuseppe; Salvemini, Marco; Savini, Grazia; Schreiner, Patrick; Scolari, Francesca; Siciliano, Paolo; Sim, Sheina B; Tsiamis, George; Ureña, Enric; Vlachos, Ioannis S; Werren, John H; Wimmer, Ernst A; Worley, Kim C; Zacharopoulou, Antigone; Richards, Stephen; Handler, Alfred M

    2016-09-22

    The Mediterranean fruit fly (medfly), Ceratitis capitata, is a major destructive insect pest due to its broad host range, which includes hundreds of fruits and vegetables. It exhibits a unique ability to invade and adapt to ecological niches throughout tropical and subtropical regions of the world, though medfly infestations have been prevented and controlled by the sterile insect technique (SIT) as part of integrated pest management programs (IPMs). The genetic analysis and manipulation of medfly has been subject to intensive study in an effort to improve SIT efficacy and other aspects of IPM control. The 479 Mb medfly genome is sequenced from adult flies from lines inbred for 20 generations. A high-quality assembly is achieved having a contig N50 of 45.7 kb and scaffold N50 of 4.06 Mb. In-depth curation of more than 1800 messenger RNAs shows specific gene expansions that can be related to invasiveness and host adaptation, including gene families for chemoreception, toxin and insecticide metabolism, cuticle proteins, opsins, and aquaporins. We identify genes relevant to IPM control, including those required to improve SIT. The medfly genome sequence provides critical insights into the biology of one of the most serious and widespread agricultural pests. This knowledge should significantly advance the means of controlling the size and invasive potential of medfly populations. Its close relationship to Drosophila, and other insect species important to agriculture and human health, will further comparative functional and structural studies of insect genomes that should broaden our understanding of gene family evolution.

  6. Soybean Stem Fly, Melanagromyza sojae (Diptera: Agromyzidae), in the New World: detection of high genetic diversity from soybean fields in Brazil.

    Science.gov (United States)

    Arnemann, J A; Tay, W T; Walsh, T K; Brier, H; Gordon, K; Hickmann, F; Ugalde, G; Guedes, J V C

    2016-07-12

    Soybean Stem Fly (SSF), Melanagromyza sojae (Zehntner), belongs to the family Agromyzidae and is highly polyphagous, attacking many plant species of the family Fabaceae, including soybean and other beans. SSF is regarded as one of the most important pests in soybean fields of Asia (e.g., China, India), North East Africa (e.g., Egypt), parts of Russia, and South East Asia. Despite reports of Agromyzidae flies infesting soybean fields in Rio Grande do Sul State (Brazil) in 1983 and 2009 and periodic interceptions of SSF since the 1940s by the USA quarantine authorities, SSF has not been officially reported to have successfully established in the North and South Americas. In South America, M. sojae was recently confirmed using morphology and its complete mitochondrial DNA (mtDNA) was characterized. In the present study, we surveyed the genetic diversity of M. sojae, collected directly from soybean host plants, using partial mtDNA cytochrome oxidase I (COI) gene, and provide evidence of multiple (>10) maternal lineages in SSF populations in South America, potentially representing multiple incursion events. However, a single incursion involving multiple-female founders could not be ruled out. We identified a haplotype that was common in the fields of two Brazilian states and the individuals collected from Australia in 2013. The implications of SSF incursions in southern Brazil are discussed in relation to the current soybean agricultural practices, highlighting an urgent need for better understanding of SSF population movements in the New World, which is necessary for developing effective management options for this significant soybean pest.

  7. I-PFO: the new technology for simple and flexible implementation of high productive on-the-fly remote processes

    Science.gov (United States)

    Müllegger, Andreas; Ryba, Tracey

    2017-02-01

    Standardized production systems which can be implemented, programmed, maintained and sourced in a simple and efficient way are key for a successful global production of automobiles or related parts at component suppliers. This is also valid for systems, which are built by laser based processes. One of the key applications is remote laser welding (RLW) of "Body in White" (BIW) parts (such as hang-on parts, B-Pillars, side frames, etc.), but also builtin components (such as car seats, batteries, etc.). The majority of RLW applications are based on the implementation of a 3-D scanner optic (e.g. the PFO 3D from TRUMPF) which positions the laser beam on the various component surfaces to be welded. Over the past 10 years it has been proven that the most efficient way to build up the RLW process is to have a system where an industrial robot and a scanner optic are combined in one production cell. They usually cooperate within an "On-The-Fly" (OTF) process as this ensures minimum cycle times. Until now there are several technologies on the market which can coordinate both the robot and scanner in the OTF mode. But none of them meet all requirements of global standardized production solutions. With the introduction of the I-PFO (Intelligent Programmable Focusing Optics) technology the situation has changed. It is now possible to program or adopt complex remote processes in a fast and easy way by the "Teach-in" function via the robot teach pendant. Additionally a 3D offline designer software is an option for this system. It automatically creates the ideal remote process based on the part, fixture, production cell and required process parameters. The I-PFO technology doesn't need additional hardware due to the fact that it runs on the controller within the PFO 3D. Furthermore it works together with different types of industrial robots (e.g. ABB, Fanuc and KUKA) which allow highest flexibility for the production planning phase. Finally a single TRUMPF laser source can supply

  8. Aerodynamic coefficients of plain and helically filleted twin circular cylinders for varying wind angles of attack

    DEFF Research Database (Denmark)

    Acampora, Antonio; Georgakis, Christos T.

    2013-01-01

    Moderate vibrations continue to be recorded on the Øresund Bridge twin-stay cables. System identification techniques have been applied to investigate the aerodynamic characteristics of the cables based on ambient vibration measurements. As might be expected, the measured aerodynamic damping ratios...... vary from those estimated through use of aerodynamic coefficients of single circular cylinders, as reported in literature. To address this issue, wind tunnel tests were performed on a 1:2.3 scale section model of the Øresund Bridge cables, with and without the presence of helical fillets. In this paper...

  9. Non-Normal Impact and Penetration. Analysis for Hard Targets and Small Angles of Attack

    Science.gov (United States)

    1978-09-01

    NUMBER AU NO(S)_S. CONTRACT OR GRANT NUMBER(a) 9 PERORMIGOR XIM DDRESI1. PROGRAM ELEMENT PROJECT. TASK U. S Ary Eniner Waerwys EpermentStaion AREA A WORK...lrtrr a ,r, Mr. Ivnn h.nmInnq A ’N: Keith Amdernen -PI Library Room rG021 Genral Electric Company. TEMPO-Center :;yst. -me ,;(lence and Software f’,r

  10. Aerodynamic Numerical Testing of Megawatt Wind Turbine Blade to Find Optimum Angle of Attack

    OpenAIRE

    Sogukpinar, H.; Bozkurt, I.; Pala, M; Turkmenler, H.

    2016-01-01

    Wind energy is one of the oldest kinds of energy source used by mankind and it is dating back to thousand years. At the beginning of twentieth century, multi blades wind turbines were improved and used for charging in USA. After oil crisis in in the seventies, there was a surge of alternative energy sources in USA, Denmark and Germany. In terms of installed capacity, Germany had the leadership until 2007, then it passed to USA and finally China becomes the leader. Today, 6 MW capacity wind tu...

  11. Determination of the angle of attack on the mexico rotor using experimental data

    DEFF Research Database (Denmark)

    Yang, Hua; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2010-01-01

    characteristics from experimental data on the MEXICO (Model Experiments in controlled Conditions) rotor. Detailed surface pressure and Particle Image Velocimetry (PIV) flow field at different rotor azimuth positions were examined for determining the sectional airfoil data. It is worthwhile noting that the present...

  12. Numerical Simulation of Turbulent Flow Over of Semi-Cylindrical Profile at Zero Angle of Attack

    Directory of Open Access Journals (Sweden)

    Shebelev Alexander

    2016-01-01

    Full Text Available Results of unsteady two-dimensional numerical simulations for the turbulent flow over the semi-cylindrical profile at Reynolds number 45000 are presented. Three different turbulence RANS eddy viscosity models are used for the simulation. The calculations show the formation of alternating large-scale vortices shed in the wake of the body. The calculated averaged pressure distribution on the contour demonstrate a good agreement with the experimental data. A series of calculations have been performed for the estimation of influence of mesh resolution in the wake of streamlined body on the unsteady solution accuracy. It was found that a mesh size ~0.04 of chord length is sufficient to resolve the vortex street.

  13. An evaluation of several methods of determining the local angle of attack on wind turbine blades

    DEFF Research Database (Denmark)

    Guntur, Srinivas; Sørensen, Niels N.

    2014-01-01

    existing as well as new full rotor CFD computations of the MEXICO rotor are used in this analysis. A more accurate estimation of the AOA is possible from 3D full rotor CFD computations, but when working with experimental data, pressure measurements and sectional forces are often the only data available....... The aim of this work is to analyse the reliability of some of the simpler methods of estimating the 3D effective AOA compared some of the more rigorous CFD based methods....

  14. Ever Fly a Tetrahedron?

    Science.gov (United States)

    King, Kenneth

    2004-01-01

    Few things capture the spirit of spring like flying a kite. Watching a kite dance and sail across a cloud spotted sky is not only a visually appealing experience it also provides a foundation for studies in science and mathematics. Put simply, a kite is an airfoil surface that flies when the forces of lift and thrust are greater than the forces of…

  15. Response of composite laminates on impact of high velocity projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Siva Kumar, K.; Balakrishna Bhat, T. [Defence Metallurgical Research Lab., Hyderabad (India)

    1998-05-01

    Past work on damage of composites subjected to low velocity and hypervelocity impact has been briefly reviewed and some new results on the glass fibre reinforced plastic composite laminates impacted with high velocity projectiles are presented. The effect of thickness of the laminates and the angle of attack on the energy absorption by the composite laminates and the area of damage caused by impact are described. A correlation is made between the energy absorption and the area of damage. Also described is a new method called infiltration radiography useful for assessing the damage in laminated composites upon ballistic impact. (orig.) 28 refs.

  16. Flying and Your Child's Ears

    Science.gov (United States)

    ... Media Flying and Your Child's Ears KidsHealth > For Parents > Flying and Your Child's Ears Print A A A What's in this article? Flying's Effects on Ears Tips for Easing Ear Pain en español Como cuidar los oídos de su hijo(a) cuando vuele en avión Flying's Effects on ...

  17. 从高碳粉煤灰中浮选回收炭的试验研究%Carbon recovery by flotation from high-carbon fly ash

    Institute of Scientific and Technical Information of China (English)

    杨大兵; 陈萱

    2012-01-01

    Guided by process mineralogy, experimental study of carbon recovery by flotation from high-carbon fly ash in a certain power plant was carried out. The results show that the fineness of fly ash and the amount of flotation reagents are the factors that affect the flotation efficiency most. By the flotation process of " one roughing and one scavenging " , fine carbon with fixed carbon content of 58. 56% and 49. 20% can be obtained with a total recovery rate of 89. 32% and the fixed carbon content in tail ash decreases to 5. 86%, while, by the closed circuit flotation process test, fine carbon with fixed carbon content of 76. 93% can be obtained with a total recovery rate of 70. 17% and the fixed carbon content in tail ash decreases to 11. 89%. Fine carbon and the tail ash can be both comprehensively utilized again.%基于工艺矿物学原理,对某动力厂排放的高碳粉煤灰进行浮选回收炭的可选性试验.结果表明,粉煤灰细度和浮选药剂用量是影响其浮选效率的重要因素.经过“一粗一扫”的浮选流程,可得固定炭含量分别为58.56%和49.20%的精炭,总回收率达到89.32%,尾灰的固定炭含量降至5.86%;而经过浮选全流程试验后,可得固定炭含量为76.93%的精炭,总回收率为70.17%,尾灰固定炭含量为11.89%,且精炭和尾灰均可综合再利用.

  18. Flying in North America

    Directory of Open Access Journals (Sweden)

    Jaromír Procházka

    2013-01-01

    Full Text Available Flying all over the world is very challenging and demanding. Although ICAO is covering every specific detail by rules, there are some personal experiences which cannot be substituted. Some of them are point out in the article.

  19. Effect of Climate Change on Service Life of High Volume Fly Ash Concrete Subjected to Carbonation—A Korean Case Study

    Directory of Open Access Journals (Sweden)

    Ki-Bong Park

    2017-01-01

    Full Text Available The increase in CO2 concentrations and global warming will increase the carbonation depth of concrete. Furthermore, temperature rise will increase the rate of corrosion of steel rebar after carbonation. On the other hand, compared with normal concrete, high volume fly ash (HVFA concrete is more vulnerable to carbonation-induced corrosion. Carbonation durability design with climate change is crucial to the rational use of HVFA concrete. This study presents a probabilistic approach that predicts the service life of HVFA concrete structures subjected to carbonation-induced corrosion resulting from increasing CO2 concentrations and temperatures. First, in the corrosion initiation stage, a hydration-carbonation integration model is used to evaluate the contents of the carbonatable material, porosity, and carbonation depth of HVFA concrete. The Monte Carlo method is adopted to determine the probability of corrosion initiation. Second, in the corrosion propagation stage, an updated model is proposed to evaluate the rate of corrosion, degree of corrosion for cover cracking of concrete, and probability of corrosion cracking. Third, the whole service life is determined considering both corrosion initiation stage and corrosion propagation stage. The analysis results show that climate change creates a significant impact on the service life of durable concrete.

  20. Experimental study of high volume fly ash pumping concrete compressive strength early%大掺量粉煤灰泵送混凝土早期抗压强度的试验研究

    Institute of Scientific and Technical Information of China (English)

    刘思海; 侍克斌; 吴福飞

    2014-01-01

    通过理论分析和试验,研究了大掺量粉煤灰对混凝土早期抗压强度及成本的影响。试验所选用的胶凝材料总量为375 kg,以0~55%的粉煤灰替代水泥,减水剂的掺量固定为1.0%,引气剂的掺量固定为1.2‱。通过坍落度及不同龄期抗压强度等对比分析粉煤灰掺量对混凝土和易性及早期强度的影响。结果表明,混凝土早期抗压强度及成本随着粉煤灰掺量的增大而逐渐减小,运用粉煤灰等质量代替水泥(P·O 42.5级水泥)可配制出28 d抗压强度为20 MPa以上,成本大大降低的大掺量粉煤灰混凝土。研究的结论为新疆地区粉煤灰的应用提供了有效途径,有助于制备高性能混凝土。%Through theoretical analysis and test,studied the effect of high volume fly ash on concrete compressive strength and cost. To-tal cementitious materials test for the selected 375 kg,with 0~55%fly ash instead of cement,the amount of superplasticizer was fixed at 1%,dosage of air entraining agent was fixed at 1.2‱.Through the slump and compressive strength of comparative analysis of the influence of fly ash on concrete workability and early strength. The results showed that ,the concrete compressive strength and cost decreased gradu-ally with the increase in the amount of fly ash,fly ash and other quality instead of using cement (42.5 ordinary portland cement)can be made by 28 d compressive strength was more than 20 MPa,a large amount of fly ash can reduce the cost of concrete. Provided an effective way for research conclusion was the application of fly ash in Xinjiang ,contributed to the preparation of high performance concrete.

  1. The Fly Printer - Extended

    DEFF Research Database (Denmark)

    Beloff, Laura; Klaus, Malena

    2016-01-01

    Artist talk / Work-in-progress What is the purpose of a machine or an artifact, like the Fly Printer, that is dislocated, that produces images that have no meaning, no instrumentality, that depict nothing in the world? The biological and the cultural are reunited in this apparatus as a possibilit...... the results. The extended version of the Fly Printer containing the technological perception and DNNs is a collaboration between Laura Beloff and Malene Theres Klaus...

  2. Açai Palm Fruit (Euterpe oleracea Mart.) Pulp Improves Survival of Flies on a High Fat Diet

    OpenAIRE

    Sun, Xiaoping; Seeberger, Jeanne; Alberico, Thomas; Wang, Chunxu; Wheeler, Charles T.; Schauss, Alexander G.; Zou, Sige

    2010-01-01

    Reducing oxidative damage is thought to be an effective aging intervention. Açai, a fruit indigenous to the Amazon, is rich in phytochemicals that possesses high anti-oxidant activities, and has anti-inflammatory, anti-cancer and anti-cardiovascular disease properties. However, little is known about its potential anti-aging properties especially at the organismal level. Here we evaluated the effect of açai pulp on modulating lifespan in Drosophila melanogaster. We found that açai supplementat...

  3. Quantification of insect nitrogen utilization by the venus fly trap Dionaea muscipula catching prey with highly variable isotope signatures.

    Science.gov (United States)

    Schulze, W; Schulze, E D; Schulze, I; Oren, R

    2001-05-01

    Dionaea is a highly specialized carnivorous plant species with a unique mechanism for insect capture. The leaf is converted into an osmotically driven trap that closes when an insect triggers sensory trichomes. This study investigates the significance of insect capture for growth of Dionaea at different successional stages after a fire, under conditions where the prey is highly variable in its isotope signature. The contribution of insect-derived nitrogen (N) was estimated using the natural abundance of 15N. In contrast to previous 15N studies on carnivorous plants, the problem emerges that delta15N values of prey insects ranged between -4.47 per thousand (grasshoppers) and +7.21 per thousand (ants), a range that exceeds the delta15N values of non carnivorous reference plants (-4.2 per thousand) and soils (+3 per thousand). Thus, the isotope-mixing model used by Shearer and Kohl to estimate the amount of insect-derived N is not applicable. In a novel approach, the relationships of delta15N values of different organs with delta15N of trapping leaves were used to estimate N partitioning within the plant. It is estimated that soon after fire approximately 75% of the nitrogen is obtained from insects, regardless of plant size or developmental stage. The estimates are verified by calculating the average isotope signatures of insects from an isotope mass balance and comparing this with the average measured delta15N values of insects. It appears that for Dionaea to survive and reach the flowering stage, seedlings must first reach the 6th-leaf rosette stage, in which trap surface area nearly doubles and facilitates the capture of large insects. Large amounts of nitrogen thus made available to plants may facilitate an enhanced growth rate and the progressive production of additional large traps. Dionaea reaches a maximum abundance after fire when growth of the competing vegetation is suppressed. About 10 years after fire, when grasses and shrubs recover, Dionaea becomes

  4. A new black fly isolate of Bacillus thuringiensis autoagglutinating strain highly toxic to Simulium pertinax (Kollar (Diptera, Simuliidae larvae

    Directory of Open Access Journals (Sweden)

    Clara FG Cavados

    2005-11-01

    Full Text Available Formulations containing the entomopathogenic Bacillus thuringiensis serovar israelensis strain IPS-82 has been widely applied for mosquito control around the world. Strain IPS-82 is highly active against Aedes aegypti but less active against other well-known vectors such as Culex quinquefasciatus and Simulium spp. larvae. Eighteen strains of B. thuringiensis were isolated from Simulium pertinax larvae naturally occurring in rivers of Southeast Brazil with one demonstrating special toxic effects. Simulated field tests against S. pertinax larvae showed that the native Brazilian autoagglutinanting B. thuringiensis (LFB-FIOCRUZ 1035 has an LC50 at least 25 times lower than the standard IPS-82 strain. The same bacterial preparation was also tested against Ae. aegypti larvae in laboratory trials and the LC50 values obtained with LFB-FIOCRUZ 1035 were at least three times lower than the one for the IPS 82 strain. The results indicate that this strain is more toxic than the standard B. thuringiensis serovar israelensis (H14 in the two Dipteran species tested. It is noteworthy that differences between LC50 values were more pronounced in S. pertinax larvae, the source of the original isolation.

  5. Estimating the abundance of airborne pollen and fungal spores at variable elevations using an aircraft: how high can they fly?

    Science.gov (United States)

    Damialis, Athanasios; Kaimakamis, Evangelos; Konoglou, Maria; Akritidis, Ioannis; Traidl-Hoffmann, Claudia; Gioulekas, Dimitrios

    2017-03-01

    Airborne pollen and fungal spores are monitored mainly in highly populated, urban environments, for allergy prevention purposes. However, their sources can frequently be located outside cities’ fringes with more vegetation. So as to shed light to this paradox, we investigated the diversity and abundance of airborne pollen and fungal spores at various environmental regimes. We monitored pollen and spores using an aircraft and a car, at elevations from sea level to 2,000 m above ground, in the region of Thesssaloniki, Greece. We found a total of 24 pollen types and more than 15 spore types. Pollen and spores were detected throughout the elevational transect. Lower elevations exhibited higher pollen concentrations in only half of plant taxa and higher fungal spore concentrations in only Ustilago. Pinaceae and Quercus pollen were the most abundant recorded by airplane (>54% of the total). Poaceae pollen were the most abundant via car measurements (>77% of the total). Cladosporium and Alternaria spores were the most abundant in all cases (aircraft: >69% and >17%, car: >45% and >27%, respectively). We conclude that pollen and fungal spores can be diverse and abundant even outside the main source area, evidently because of long-distance transport incidents.

  6. Electrodialytic removal of Cd from biomass combustion fly ash suspensions

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor M.; Ottosen, Lisbeth M.; Damoe, Anne J.

    2013-01-01

    Due to relatively high concentrations of Cd, biomass combustion fly ashes often fail to meet Danish legislative requirements for recycling as fertilizer. In this study, the potential of using electrodialytic remediation for removal of Cd from four different biomass combustion fly ashes was invest......Due to relatively high concentrations of Cd, biomass combustion fly ashes often fail to meet Danish legislative requirements for recycling as fertilizer. In this study, the potential of using electrodialytic remediation for removal of Cd from four different biomass combustion fly ashes...

  7. Alkaline hydrothermal zeolites synthesized from high SiO{sub 2} and Al{sub 2}O{sub 3} co-disposal fly ash filtrates

    Energy Technology Data Exchange (ETDEWEB)

    Vernon S. Somerset; Leslie F. Petrik; Richard A. White; Michael J. Klink; David Key; Emmanuel I. Iwuoha

    2005-12-01

    A co-disposal reaction was used wherein fly ash (FA) was reacted with acid mine drainage (AMD), to collect filtrates for zeolite synthesis. Raw fly ash as well as fly ash leached with HCl were subjected to the same alkaline hydrothermal zeolite synthesis conditions, as for the co-disposal filtrates, in order to evaluate the zeolitic material obtained. The Si and Al contents of the fly ash (FA) filtrates were used as precursor species for the alkaline hydrothermal conversion of the fly ash filtrates into zeolites. These filtrates were then analysed by XRF spectrometry for quantitative determination of SiO{sub 2} and Al{sub 2}O{sub 3}. The (SiO{sub 2})/(Al{sub 2}O{sub 3}) ratio obtained in the filtrates range from 1.4 to 2.5. The (SiO{sub 2})/(Al{sub 2}O{sub 3}) ratio was used to predict whether the fly ash filtrates could successfully be converted into faujasite zeolitic material by the adopted synthesis procedures. If the (SiO{sub 2})/(Al{sub 2}O{sub 3}) ratio is higher than 1.5 in the co-disposal filtrates, it favours the formation of faujasite. The zeolite synthesis included an alkaline fusion of the co-disposal filtrates, followed by aging for 8 hours and hydrothermal conversion by crystallisation at 100{sup o}C. Different variables were investigated during the synthesis of zeolite to ascertain their influence on the end product. These variables include adding different amounts of deionised water to the FA-related starting material, using different compositions of FA related starting material and different FA:NaOH ratios in fusing the starting material. 15 refs., 3 figs., 2 tabs.

  8. Wolbachia in Anastrepha fruit flies (Diptera: Tephritidae).

    Science.gov (United States)

    Coscrato, Virginia E; Braz, Antônio S K; P Perondini, André L; Selivon, Denise; Marino, Celso L

    2009-09-01

    Endosymbiotic bacteria of the genus Wolbachia are widespread among arthropods and cause a variety of reproductive abnormalities, such as cytoplasmic incompatibility, thelytokous parthenogenesis, male-killing, and host feminization. In this study, we used three sets of Wolbachia-specific primers (16S rDNA, ftsZ, and wsp) in conjunction with the polymerase chain reaction (PCR), cloning and sequencing to study the infection of fruit flies (Anastrepha spp. and Ceratitis capitata) by Wolbachia. The flies were collected at several localities in Brazil and at Guayaquil, Ecuador. All of the fruit flies studied were infected with Wolbachia supergroup A, in agreement with the high prevalence of this group in South America. Phylogenetic analysis showed that the wsp gene was the most sensitive gene for studying the relationships among Wolbachia strains. The Wolbachia sequences detected in these fruit flies were similar to those such as wMel reported for other fruit flies. These results show that the infection of Anastrepha fruit flies by Wolbachia is much more widespread than previously thought.

  9. Tail buffet alleviation of high performance twin tail aircraft using offset piezoceramic stack actuators and acceleration feedback control

    Science.gov (United States)

    Bayon de Noyer, Maxime P.

    In High Performance Twin-Tail Aircraft (HPTTA), tail buffet occurs during high angles of attack maneuvers. At high angles of attack, flow separates and vortices are convected by the geometry of the wing-fuselage interface toward the vertical tails. This phenomenon, along with the aeroelastic coupling of the tail structural assembly, results in vibrations that can shorten the fatigue life of the empennage assembly and limit the flight envelope due to the large amplitude of the fin vibrations. The main goal of this research was to develop an active buffet alleviation system for HPTTA using Offset Piezoceramic Stack Actuators (OPSA) in combination with Acceleration Feedback Control (AFC) theory. In order to complete this task, the research work was divided into three main areas. First, two new methods for the design of non-collocated AFC controller parameters were developed for pure active damping applications and for quadratic performance criterion minimization. Second, a new type of moment inducing actuator based on piezoceramic stacks, the OPSA, was developed to provide high control authority while satisfying high reliability and maintainability requirements. A modal model of the OPSA acting on a benchmark structure was developed to create a low frequency approximation of the actuator and to optimize its offset distance and its placement. Third, because of the non-availability of reliable models for the controlled structure and the buffet-induced loads, a control system design method, based solely on the use of experimental data, was developed. Finally, two sets of experiments were conducted to show the feasibility of controlling buffet-induced vibrations during high angle of attack operations of a HPTTA. The first experiment validated both the effectiveness and the robustness of the active buffet alleviation system on an aeroelastically scaled model in wind tunnel tests. The second experiment showed that the combination of OPSA and AFC could suppress vibrations in

  10. A Novel Method for Tracking Individuals of Fruit Fly Swarms Flying in a Laboratory Flight Arena.

    Science.gov (United States)

    Cheng, Xi En; Qian, Zhi-Ming; Wang, Shuo Hong; Jiang, Nan; Guo, Aike; Chen, Yan Qiu

    2015-01-01

    The growing interest in studying social behaviours of swarming fruit flies, Drosophila melanogaster, has heightened the need for developing tools that provide quantitative motion data. To achieve such a goal, multi-camera three-dimensional tracking technology is the key experimental gateway. We have developed a novel tracking system for tracking hundreds of fruit flies flying in a confined cubic flight arena. In addition to the proposed tracking algorithm, this work offers additional contributions in three aspects: body detection, orientation estimation, and data validation. To demonstrate the opportunities that the proposed system offers for generating high-throughput quantitative motion data, we conducted experiments on five experimental configurations. We also performed quantitative analysis on the kinematics and the spatial structure and the motion patterns of fruit fly swarms. We found that there exists an asymptotic distance between fruit flies in swarms as the population density increases. Further, we discovered the evidence for repulsive response when the distance between fruit flies approached the asymptotic distance. Overall, the proposed tracking system presents a powerful method for studying flight behaviours of fruit flies in a three-dimensional environment.

  11. A Novel Method for Tracking Individuals of Fruit Fly Swarms Flying in a Laboratory Flight Arena.

    Directory of Open Access Journals (Sweden)

    Xi En Cheng

    Full Text Available The growing interest in studying social behaviours of swarming fruit flies, Drosophila melanogaster, has heightened the need for developing tools that provide quantitative motion data. To achieve such a goal, multi-camera three-dimensional tracking technology is the key experimental gateway. We have developed a novel tracking system for tracking hundreds of fruit flies flying in a confined cubic flight arena. In addition to the proposed tracking algorithm, this work offers additional contributions in three aspects: body detection, orientation estimation, and data validation. To demonstrate the opportunities that the proposed system offers for generating high-throughput quantitative motion data, we conducted experiments on five experimental configurations. We also performed quantitative analysis on the kinematics and the spatial structure and the motion patterns of fruit fly swarms. We found that there exists an asymptotic distance between fruit flies in swarms as the population density increases. Further, we discovered the evidence for repulsive response when the distance between fruit flies approached the asymptotic distance. Overall, the proposed tracking system presents a powerful method for studying flight behaviours of fruit flies in a three-dimensional environment.

  12. 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.

  13. The whole genome sequence of the Mediterranean fruit fly, Ceratitis capitata (Wiedmann), reveals insights into the biology and adaptive evolution of a highly invasive pest species

    Science.gov (United States)

    The Mediterranean fruit fly is one of the most destructive agricultural pests throughout the world due to its broad host plant range that includes more than 260 different fruits, flowers, vegetables, and nuts. Host preferences vary in different regions of the world, which can be associated with its ...

  14. Blood-meal identification in phlebotomine sand flies (Diptera: Psychodidae) from Valle Hermoso, a high prevalence zone for cutaneous leishmaniasis in Ecuador.

    Science.gov (United States)

    Anaguano, David F; Ponce, Patricio; Baldeón, Manuel E; Santander, Stephanie; Cevallos, Varsovia

    2015-12-01

    Cutaneous leishmaniasis is a neglected tropical disease transmitted by phlebotomine sand flies of the genus Lutzomyia. In South America, cutaneous leishmaniasis is endemic in the majority of countries. There are no previous reports of phlebotomine sand fly host feeding sources in Ecuador. We identified blood meal sources for phlebotomine sand fly species in Valle Hermoso, a hyper endemic area for leishmaniasis in Ecuador. Phlebotomine sand fly collections were carried out during the dry and rainy seasons. PCR and multiplex PCR were performed from DNA extracted from the abdomens of blood-fed females to specifically identify the avian and mammalian blood meal sources. Avian-blood (77%), mammalian-blood (16%) and mixed avian-mammalian blood (7%) were found in the samples. At the species level, blood from chickens (35.5%), humans (2.8%), cows (2.8%) and dogs (1.9%) was specifically detected. Nyssomyia trapidoi was the most common species of Lutzomyia found that fed on birds. The present results may aid the development of effective strategies to control leishmaniasis in Ecuador.

  15. Jetstar Asia's Growth Flies High

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ For budget travelers,low cost carriers(LCCs)are the best choice.But to the budget travelers in China,there are not many LCC options.According to APGDAT,a data por tal for accessing key aviation planning data,from 2006-11,despite a 57-percent growth in LCC China flights,LCCs represent only 3percent of flights in the country.

  16. ANALYSIS OF FLYING BIKE

    OpenAIRE

    Momin Irfan Ali Nasir Husain *1, Shah mohd. Rafique rahmatullah *2, Naumanulhaq Barkatullah Shaikh *3, Khatib Mohd. Azimuddin Najimuddin *4, Ansari Mohammad Naasir Shamsudduha *5, Ansari Mohammad Parvez Abdul Qayyum*6, Momin Mohammad Rayyan Mohammad Shakeel*7, Ansari Peer Mohammed Munna *8, Prof. Mohd. Musharraf Aamir

    2016-01-01

    Flying Bike vertical take-off and landing (VTOL) type machine which also follows Newton’s third law. It is thought of as a conventional type of aircraft with special features added to enable it to rise vertically during take-off and to land from a vertical descent.  It flies with two propellers located at front and back side. These propellers are having hovering abilities. The vehicle is controlled by tilting the propellers by using lever mechanism. Rotation is carried out by diffe...

  17. Fruit flies (Diptera, Tephritidae) and their associations with native host plants in a remnant area of the highly endangered Atlantic Rain Forest in the State of Espírito Santo, Brazil.

    Science.gov (United States)

    Uramoto, K; Martins, D S; Zucchi, R A

    2008-10-01

    The results presented in this paper refer to a host survey, lasting approximately three and a half years (February 2003-July 2006), undertaken in the Vale do Rio Doce Natural Reserve, a remnant area of the highly endangered Atlantic Rain Forest located in Linhares County, State of Espírito Santo, Brazil. A total of 330 fruit samples were collected from native plants, representing 248 species and 51 plant families. Myrtaceae was the most diverse family with 54 sampled species. Twenty-eight plant species, from ten families, are hosts of ten Anastrepha species and of Ceratitis capitata (Wiedemann). Among 33 associations between host plants and fruit flies, 20 constitute new records, including the records of host plants for A. fumipennis Lima and A. nascimentoi Zucchi. The findings were discussed in the light of their implications for rain forest conservation efforts and the study of evolutionary relationships between fruit flies and their hosts.

  18. 粉煤灰对C50高性能混凝土干缩的影响%Effect of Fly ash on Dry Shrinkage of C50 High-Performance Concrete

    Institute of Scientific and Technical Information of China (English)

    葛艳军; 王文林

    2012-01-01

      研究了粉煤灰掺量对C50高性能混凝土HPC工作性、抗压强度以及干缩的影响。试验结果表明:粉煤灰掺量在10%~20%范围内,提高了混凝土的工作性能、后期抗压强度,降低了混凝土的干缩值。%  This paper studied the impact of fly ash on the workability, compressive strength and dry shrinkage of C50 high-performance concrete. The results showed that the performance of the concrete and its late compressive strength were improved, the drying shrinkage value reduced when fly ash was mixed with 10%-20%.

  19. HiRISE/NEOCE: an ESA M5 formation flying proposed mission combining high resolution and coronagraphy for ultimate observations of the chromosphere, corona and interface

    Science.gov (United States)

    Damé, Luc; Von Fay-Siebenburgen (Erdélyi), Robert

    2016-07-01

    The global understanding of the solar environment through the magnetic field emergence and dissipation, and its influence on Earth, is at the centre of the four major thematics addressed by HiRISE/NEOCE (High Resolution Imaging and Spectroscopy Explorer/New Externally Occulted Coronagraph Experiment). They are interlinked and also complementary: the internal structure of the Sun determines the surface activity and dynamics that trigger magnetic field structuring which evolution, variation and dissipation will, in turn, explain the coronal heating onset and the major energy releases that feed the influence of the Sun on Earth. The 4 major themes of HiRISE/NEOCE are: - fine structure of the chromosphere-corona interface by 2D spectroscopy in FUV at very high resolution; - coronal heating roots in inner corona by ultimate externally-occulted coronagraphy; - resolved and global helioseismology thanks to continuity and stability of observing at L1 Lagrange point; - solar variability and space climate with a global comprehensive view of UV variability as well. Recent missions have shown the definite role of waves and of the magnetic field deep in the inner corona, at the chromosphere-corona interface, where dramatic changes occur. The dynamics of the chromosphere and corona is controlled by the emerging magnetic field, guided by the coronal magnetic field. Accordingly, the direct measurement of the chromospheric and coronal magnetic fields is of prime importance. This is implemented in HiRISE/NEOCE, to be proposed for ESA M5 ideally placed at the L1 Lagrangian point, providing FUV imaging and spectro-imaging, EUV and XUV imaging and spectroscopy, and ultimate coronagraphy by a remote external occulter (two satellites in formation flying 375 m apart minimizing scattered light) allowing to characterize temperature, densities and velocities up to the solar upper chromosphere, transition zone and inner corona with, in particular, 2D very high resolution multi

  20. Fiber optics that fly

    Science.gov (United States)

    Wilcox, Michael J.; Thelen, Donald C., Jr.

    1996-11-01

    The need for autonomous systems to work under unanticipated conditions requires the use of smart sensors. High resolution systems develop tremendous computational loads. Inspiration from animal vision systems can guide us in developing preprocessing approaches implementable in real time with high resolution and deduced computational load. Given a high quality optical path and a 2D array of photodetectors, the resolution of a digital image is determined by the density of photodetectors sampling the image. In order to reconstruct an image, resolution is limited by the distance between adjacent detectors. However, animal eyes resolve images 10-100 times better than either the acceptance angle of a single photodetector or the center-to-center distance between neighboring photodetectors. A new model of the fly's visual system emulates this improved performance, offering a different approach to subpixel resolution. That an animal without a cortex is capable of this performance suggests that high level computation is not involved. The model takes advantage of a photoreceptor cell's internal structure for capturing light. This organelle is a waveguide. Neurocircuitry exploits the waveguide's optical nonlinearities, namely in the shoulder region of its gaussian sensitivity-profile, to extract high resolution information from the visual scene. The receptive fields of optically disparate inputs overlap in space. Photoreceptor input is continuous rather than discretely sampled. The output of the integrating module is a signal proportional to the position of the target within the detector array. For tracking a point source, resolution is 10 times better than the detector spacing. For locating absolute position and orientation of an edge, the model performs similarly. Analog processing is used throughout. Each element is an independent processor of local luminance. Information processing is in real time with continuous update. This processing principle will be reproduced in an

  1. Experimental Study on Volume for Fly Ash of Building Block

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2013-04-01

    Full Text Available Fly ash is a waste substance from thermal power plants, steel mills, etc. That is found in abundance in the world. It has polluted the environment, wasting the cultivated land. This study introduces an experimental research on fly ash being reused effectively, the study introduces raw materials of fly ash brick, production process and product inspection, fly ash content could be amounted to 40%~75%. High doping fly ash bricks are manufactured, which selects wet fly ash from the power plants, adding aggregate with reasonable ratio and additives with reasonable dosage and do the experimental research on manufacture products for properties, production technology and selection about technology parameter of production equipment. Index of strength grade and freezing-thawing resisting etc and the high doping fly ash brick building which we are working on can achieve the national standard on building materials industry. Based on the tests, this achievement of research has a very wide practical prospect in using fly ash, industrial waste residue, environmental protection and reducing the cost of enterprises. The efficient reuse of fly ash from coal boiler and power plants has very vital significance of protecting the environment, benefiting descendants and developing of circular economy.

  2. How mosquitoes fly in the rain

    Science.gov (United States)

    Dickerson, Andrew; Shankles, Peter; Madhavan, Nihar; Hu, David

    2011-11-01

    Mosquitoes thrive during rainfall and high humidity. If raindrops are 50 times heavier than mosquitoes, how do mosquitoes fly in the rain? In this combined experimental and theoretical study, we measure the impact force between a falling drop and a free-flying mosquito. High-speed videography of mosquitoes and custom-built mimics reveals a mosquito's low inertia renders it impervious to falling drops. Drops do not splash on mosquitoes, but simply push past them allowing a mosquito to continue on its flight path undeterred. We rationalize the force imparted using scaling relations based on the time of rebound between a falling drop and a free body of significantly less mass.

  3. A novel highly divergent protein family identified from a viviparous insect by RNA-seq analysis: a potential target for tsetse fly-specific abortifacients.

    Directory of Open Access Journals (Sweden)

    Joshua B Benoit

    2014-04-01

    Full Text Available In tsetse flies, nutrients for intrauterine larval development are synthesized by the modified accessory gland (milk gland and provided in mother's milk during lactation. Interference with at least two milk proteins has been shown to extend larval development and reduce fecundity. The goal of this study was to perform a comprehensive characterization of tsetse milk proteins using lactation-specific transcriptome/milk proteome analyses and to define functional role(s for the milk proteins during lactation. Differential analysis of RNA-seq data from lactating and dry (non-lactating females revealed enrichment of transcripts coding for protein synthesis machinery, lipid metabolism and secretory proteins during lactation. Among the genes induced during lactation were those encoding the previously identified milk proteins (milk gland proteins 1-3, transferrin and acid sphingomyelinase 1 and seven new genes (mgp4-10. The genes encoding mgp2-10 are organized on a 40 kb syntenic block in the tsetse genome, have similar exon-intron arrangements, and share regions of amino acid sequence similarity. Expression of mgp2-10 is female-specific and high during milk secretion. While knockdown of a single mgp failed to reduce fecundity, simultaneous knockdown of multiple variants reduced milk protein levels and lowered fecundity. The genomic localization, gene structure similarities, and functional redundancy of MGP2-10 suggest that they constitute a novel highly divergent protein family. Our data indicates that MGP2-10 function both as the primary amino acid resource for the developing larva and in the maintenance of milk homeostasis, similar to the function of the mammalian casein family of milk proteins. This study underscores the dynamic nature of the lactation cycle and identifies a novel family of lactation-specific proteins, unique to Glossina sp., that are essential to larval development. The specificity of MGP2-10 to tsetse and their critical role during

  4. Kite-Flying Fun

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China’s kite capital welcomes flying enthusiasts from across the world to its annual carnival Tens of thousands of kite enthusiast from all over the world gathered under the growing swarm of brightly colored kites. Some of the floating and billowing forms had been fashioned into

  5. Hydration of fly ash cement

    Energy Technology Data Exchange (ETDEWEB)

    Etsuo Sakai; Shigeyoshi Miyahara; Shigenari Ohsawa; Seung-Heun Lee; Masaki Daimon [Tokyo Institute of Technology, Tokyo (Japan). Department of Metallurgy and Ceramics Science, Graduate School of Science and Engineering

    2005-06-01

    It is necessary to establish the material design system for the utilization of large amounts of fly ash as blended cement instead of disposing of it as a waste. Cement blended with fly ash is also required as a countermeasure to reduce the amount of CO{sub 2} generation. In this study, the influences of the glass content and the basicity of glass phase on the hydration of fly ash cement were clarified and hydration over a long curing time was characterized. Two kinds of fly ash with different glass content, one with 38.2% and another with 76.6%, were used. The hydration ratio of fly ash was increased by increasing the glass content in fly ash in the specimens cured for 270 days. When the glass content of fly ash is low, the basicity of glass phase tends to decrease. Reactivity of fly ash is controlled by the basicity of the glass phase in fly ash during a period from 28 to 270 days. However, at an age of 360 days, the reaction ratios of fly ash show almost identical values with different glass contents. Fly ash also affected the hydration of cement clinker minerals in fly ash cement. While the hydration of alite was accelerated, that of belite was retarded at a late stage.

  6. Microstructural and compositional change of NaOH-activated high calcium fly ash by incorporating Na-aluminate and co-existence of geopolymeric gel and C–S–H(I)

    KAUST Repository

    Oh, Jae Eun

    2012-05-01

    This study explores the reaction products of alkali-activated Class C fly ash-based aluminosilicate samples by means of high-resolution synchrotron X-ray diffraction (HSXRD), scanning electron microscope (SEM), and compressive strength tests to investigate how the readily available aluminum affects the reaction. Class C fly ash-based aluminosilicate raw materials were prepared by incorporating Na-aluminate into the original fly ashes, then alkali-activated by 10 M NaOH solution. Incorporating Na-aluminate reduced the compressive strength of samples, with the reduction magnitude relatively constant regardless of length of curing period. The HSXRD provides evidence of the co-existence of C-S-H with geopolymeric gels and strongly suggests that the C-S-H formed in the current system is C-S-H(I). The back-scattered electron images suggest that the C-S-H(I) phase exists as small grains in a finely intermixed form with geopolymeric gels. Despite providing extra source of aluminum, adding Na-aluminate to the mixes did not decrease the Si/Al ratio of the geopolymeric gel. © 2012 Elsevier Ltd.

  7. Protective method of flying control system under high altitude nuclear detonation%高空核爆环境下飞行控制系统的防护方法

    Institute of Scientific and Technical Information of China (English)

    林金永; 张春侠; 周春梅; 马继峰; 董文杰

    2012-01-01

    Strong electromagnetic radiation under high altitude nuclear detonation can cause the instantaneous and permanent degradation or failure of (he functions of spacecraft control system. The latent threat and damage effects on spacecraft flying control system under strong electromagnetic radiation environments are firstly analyzed, then the relevant protective concepts and methods for flying control system under strong electromagnetic pulse and strong radiation environments are investigated. The ability resisting strong electromagnetic radiation damage of spacecraft will be significantly improved when the protective method is applied to flying control system for radiation hardening design.%针对高空核爆引起的强电磁辐射使空间飞行器控制系统发生瞬时和持续的功能降级以及失效的问题,分析了强电磁辐射对空间飞行器飞行控制系统的潜在威胁和损伤效应,提出了强电磁脉冲辐射和强射线辐射环境下飞行控制系统的一些防护概念和方法.这些方法应用于飞行控制系统抗辐射加固设计,可显著提高空间飞行器抗强电磁辐射损伤能力.

  8. Visual and olfactory enhancement of stable fly trapping

    Science.gov (United States)

    BACKGROUND: Stable flies are considered to be one of themajor blood-feeding pests in theUS livestock industry, causing losses running into billions of dollars annually. Adult stable flies are highly attracted to Alsynite traps; however, Alsynite is becoming increasingly difficult to obtain and is ex...

  9. 'Information on the fly': Challenges in professional communication in high technological nursing. A focus group study from a radiotherapy department in Sweden.

    Science.gov (United States)

    Widmark, Catarina; Tishelman, Carol; Gustafsson, Helena; Sharp, Lena

    2012-07-23

    Radiotherapy (RT) units are high-tech nursing environments. In Sweden, RT registered nurses (RNs) provide and manage RT in close collaboration with other professional groups, as well as providing nursing care for patients with cancer. Communication demands on these RNs are thus particularly complex. In this study, we aimed to better understand problems, strengths and change needs related to professional communication with and within the RT department, as a basis for developing a situation-specific intervention. Focus groups discussions (FGDs) were conducted with different professional (RNs, assistant nurses, physicians, engineers and physicists) and user stakeholders. Transcripts of the FGDs were inductively analyzed by a team of researchers, to generate clinically relevant and useful data. These findings give insight into RT safety climate and are presented under three major headings: Conceptualization of professional domains; Organization and leadership issues; and Communication forms, strategies and processes. The impact of existing hierarchies, including how they are conceptualized and acted out in practice, was noted throughout these data. Despite other differences, participating professionals agreed about communication problems related to RT, i.e. a lack of systems and processes for information transfer, unclear role differentiation, a sense of mutual disrespect, and ad hoc communication taking place 'on the fly'. While all professional groups recognized extensive communication problems, none acknowledged the potential negative effects on patient safety or care described in the FGD with patient representatives. While RNs often initially denied the existence of a hierarchy, they placed themselves on a hierarchy in their descriptions, describing their own role as passive, with a sense of powerlessness. Potential safety hazards described in the FGDs include not reporting medical errors and silently ignoring or actively opposing new guidelines and regulations

  10. High Reynolds number test of a NACA 651-213, a equals 0.5 airfoil at transonic speeds

    Science.gov (United States)

    Burdges, K. P.; Blackwell, J. A., Jr.; Pounds, G. A.

    1975-01-01

    Wind-Tunnel tests were conducted in the Lockheed-Georgia Company's compressible flow facility to determine the transonic two-dimensional aerodynamic characteristics of a NACA 65 sub 1-213 a = 0.50 airfoil. The results are correlated with data obtained in the NASA-Langley 8-foot transonic pressure tunnel and the NAE high Reynolds number 15x60-inch two-dimensional test facility. The tests were conducted over a Mach number range from 0.60 to 0.80 and an angle of attack range from -1 deg to 8 deg. Reynolds numbers, based on the airfoil chord, were varied.

  11. An annotated checklist of the horse flies, deer flies, and yellow flies (Diptera: Tabanidae) of Florida

    Science.gov (United States)

    The family Tabanidae includes the horse flies, deer flies, and yellow flies and is considered a significant pest of livestock throughout the United States, including Florida. Tabanids can easily become a major pest of man, especially salt marsh species which are known to readily feed on humans and o...

  12. Pigments of fly agaric (Amanita muscaria).

    Science.gov (United States)

    Stintzing, Florian; Schliemann, Willibald

    2007-01-01

    The complex pigment pattern of fly agaric (Amanita muscaria) cap skins has been studied by LC-DAD and mass spectrometry. Among the betaxanthins the corresponding derivatives of serine, threonine, ethanolamine, alanine, Dopa, phenylalanine and tryptophan are reported for the first time to contribute to the pigment pattern of fly agarics. Betalamic acid, the chromophoric precursor of betaxanthins and betacyanins, muscaflavin and seco-dopas were also detected. Furthermore, the red-purple muscapurpurin and the red muscarubrin were tentatively assigned while further six betacyanin-like components could not be structurally allocated. Stability studies indicated a high susceptibility of pigment extracts to degradation which led to rapid colour loss thus rendering a complete characterization of betacyanin-like compounds impossible at present. Taking into account these difficulties the presented results may be a starting point for a comprehensive characterization of the pigment composition of fly agarics.

  13. Flying Drosophila stabilize their vision-based velocity controller by sensing wind with their antennae.

    Science.gov (United States)

    Fuller, Sawyer Buckminster; Straw, Andrew D; Peek, Martin Y; Murray, Richard M; Dickinson, Michael H

    2014-04-01

    Flies and other insects use vision to regulate their groundspeed in flight, enabling them to fly in varying wind conditions. Compared with mechanosensory modalities, however, vision requires a long processing delay (~100 ms) that might introduce instability if operated at high gain. Flies also sense air motion with their antennae, but how this is used in flight control is unknown. We manipulated the antennal function of fruit flies by ablating their aristae, forcing them to rely on vision alone to regulate groundspeed. Arista-ablated flies in flight exhibited significantly greater groundspeed variability than intact flies. We then subjected them to a series of controlled impulsive wind gusts delivered by an air piston and experimentally manipulated antennae and visual feedback. The results show that an antenna-mediated response alters wing motion to cause flies to accelerate in the same direction as the gust. This response opposes flying into a headwind, but flies regularly fly upwind. To resolve this discrepancy, we obtained a dynamic model of the fly's velocity regulator by fitting parameters of candidate models to our experimental data. The model suggests that the groundspeed variability of arista-ablated flies is the result of unstable feedback oscillations caused by the delay and high gain of visual feedback. The antenna response drives active damping with a shorter delay (~20 ms) to stabilize this regulator, in exchange for increasing the effect of rapid wind disturbances. This provides insight into flies' multimodal sensory feedback architecture and constitutes a previously unknown role for the antennae.

  14. Effect of fly ash on mechanical property of C80 high performance concrete%C80高性能混凝土力学性能的粉煤灰效应

    Institute of Scientific and Technical Information of China (English)

    尹宁; 王文孟; 熊芳; 崔自治

    2014-01-01

    在前期C80高性能混凝土试验研究确定的优化配合比基础上,以粉煤灰取代率和龄期为因素,应用具有位移传感器的SANS压力试验机,参照普通混凝土力学性能试验方法标准GB/T 50081-2002,进行了粉煤灰对C80高性能混凝土力学性能的作用效应试验研究。结果表明:掺适量的粉煤灰能够显著提高混凝土的抗拉强度和拉压比,就劈裂抗拉强度和拉压比而言,粉煤灰取代率存在一个最佳值;掺粉煤灰使混凝土的弹性模量降低,延性提高;掺适量粉煤灰的混凝土,其强度、拉压比和弹性模量均随龄期的增大而增大。混凝土中水化硅酸钙胶体的增多和Ca(OH)2晶体的减少是粉煤灰混凝土的抗拉强度和拉压比增大,弹性模量降低的主要原因。该研究为混凝土结构构件的抗裂设计和变形设计提供了理论支撑。%On the basis of the optimal mixture ratio of C80 high performance concrete determined by test in the early days ,with the fly ash replacement rate and age as the factors,application of SANS pressure testing machine with displacement sensor,according to the GB/T 50081-2002 Standard for test methods of mechanical properties of ordinary concrete,the effect of fly ash on the mechanical prop-erty of C80 high performance concrete was studied. The results showed that the right amount of fly ash can significantly improve the ten-sile strength,tension and compression ratio of concrete,in terms of splitting tensile strength,tension and compression ratio,fly ash replace-ment ratio is a best value.Mixing fly ash can decrease the elastic modulus ,improve ductility of concrete.Concrete with right amount of fly ash,its strength,tension and compression ratio,and elastic modulus increase with the increase of the age.About fly ash concrete,hydration calcium silicate colloid increasing and Ca(OH)2 crystals decreasing was the main reason for the tensile strength,tension and

  15. Flying Saucer? Aliens?

    Science.gov (United States)

    1961-01-01

    No, it's not a flying saucer, it is the domed top to a 70 foot long vacuum tank at the Lewis Research Center's Electric Propulsion Laboratory, Cleveland, Ohio. The three technicians shown here in protective clothing had just emerged from within the tank where they had been cleaning in the toxic mercury atmosphere, left after ion engine testing in the tank. Lewis has since been renamed the John H. Glenn Research Center.

  16. Effect of night time-intervals, height of traps and lunar phases on sand fly collection in a highly endemic area for canine leishmaniasis.

    Science.gov (United States)

    Gaglio, Gabriella; Brianti, Emanuele; Napoli, Ettore; Falsone, Luigi; Dantas-Torres, Filipe; Tarallo, Viviana D; Otranto, Domenico; Giannetto, Salvatore

    2014-05-01

    The activity of phlebotomine sand flies was monitored in a sub-urban area of Sicily in order to acquire data on seasonality and to elucidate the effect of the night time-intervals, height of traps from ground and lunar phases on the abundance of the capture. The study was conducted in the farm of the University of Messina (Italy). Light traps were placed as in the following: biweekly, from dusk to dawn, and from May to November; for three consecutive nights from 18:00 to 6:00, with the net bag being changed every 2h; for 30 days, at different heights from 18:00 to 6:00. A total of five species (i.e., Phlebotomus perniciosus, Phlebotomus neglectus, Phlebotomus sergenti, Phlebotomus perfiliewi, and Sergentomyia minuta), three of which are proven vectors of Leishmania infantum, were captured. The most abundant species was P. perniciosus (73.3%) followed by S. minuta (23.3%). The highest number of phlebotomine sand flies was collected in August and September with a peak of collection recorded in the evening (i.e., from 20:01 to 22.00). The number of phlebotomine sand flies collected at 50cm above the ground was significantly higher (P=0.041) than that captured at 150cm. Results of this study shed light on the ecology of main phlebotomine species in the Mediterranean area, and on the influence of some factors, such as time and height of traps, on the light trap capture efficiency.

  17. Diet modification and metformin have a beneficial effect in a fly model of obesity and mucormycosis.

    Science.gov (United States)

    Shirazi, Fazal; Farmakiotis, Dimitrios; Yan, Yuanqing; Albert, Nathaniel; Do, Kim-Anh; Kim-Anh, Do; Kontoyiannis, Dimitrios P

    2014-01-01

    In an experimental model of obesity and hyperglycemia in Drosophila melanogaster we studied the effect of diet modification and administration of metformin on systemic infection with Rhizopus, a common cause of mucormycosis in diabetic patients. Female Wt-type Drosophila flies were fed regular (RF) or high-fat diet (HFD; 30% coconut oil) food with or without metformin for 48 h and then injected with R. oryzae. Survival rates, glucose and triglyceride levels were compared between 1) normal-weight flies (RF), 2) obese flies (HFD), 3) obese flies fed with RF, 4) flies continuously fed on HFD + metformin, 5) flies fed on HFD + metformin, then transferred to RF, and 6) obese flies administered metformin after infection [corrected].Glucose levels were compared across groups of non-infected flies and across groups of infected flies. Survival was significantly decreased (P = 0.003) in obese flies, while post-infection glucose levels were significantly increased (P = 0.0001), compared to normal-weight flies. Diet and administration of metformin led to weight loss, normalized glucose levels during infection, and were associated with decreased mortality and tissue fungal burden. In conclusion, diet and metformin help control infection-associated hyperglycemia and improve survival in Drosophila flies with mucormycosis. Fly models of obesity bear intriguing similarities to the pathophysiology of insulin resistance and diabetes in humans, and can provide new insights into the pathogenesis and treatment of infections in obese and diabetic patients.

  18. Diet modification and metformin have a beneficial effect in a fly model of obesity and mucormycosis.

    Directory of Open Access Journals (Sweden)

    Fazal Shirazi

    Full Text Available In an experimental model of obesity and hyperglycemia in Drosophila melanogaster we studied the effect of diet modification and administration of metformin on systemic infection with Rhizopus, a common cause of mucormycosis in diabetic patients. Female Wt-type Drosophila flies were fed regular (RF or high-fat diet (HFD; 30% coconut oil food with or without metformin for 48 h and then injected with R. oryzae. Survival rates, glucose and triglyceride levels were compared between 1 normal-weight flies (RF, 2 obese flies (HFD, 3 obese flies fed with RF, 4 flies continuously fed on HFD + metformin, 5 flies fed on HFD + metformin, then transferred to RF, and 6 obese flies administered metformin after infection [corrected].Glucose levels were compared across groups of non-infected flies and across groups of infected flies. Survival was significantly decreased (P = 0.003 in obese flies, while post-infection glucose levels were significantly increased (P = 0.0001, compared to normal-weight flies. Diet and administration of metformin led to weight loss, normalized glucose levels during infection, and were associated with decreased mortality and tissue fungal burden. In conclusion, diet and metformin help control infection-associated hyperglycemia and improve survival in Drosophila flies with mucormycosis. Fly models of obesity bear intriguing similarities to the pathophysiology of insulin resistance and diabetes in humans, and can provide new insights into the pathogenesis and treatment of infections in obese and diabetic patients.

  19. TrackFly: virtual reality for a behavioral system analysis in free-flying fruit flies.

    Science.gov (United States)

    Fry, Steven N; Rohrseitz, Nicola; Straw, Andrew D; Dickinson, Michael H

    2008-06-15

    Modern neuroscience and the interest in biomimetic control design demand increasingly sophisticated experimental techniques that can be applied in freely moving animals under realistic behavioral conditions. To explore sensorimotor flight control mechanisms in free-flying fruit flies (Drosophila melanogaster), we equipped a wind tunnel with a Virtual Reality (VR) display system based on standard digital hardware and a 3D path tracking system. We demonstrate the experimental power of this approach by example of a 'one-parameter open loop' testing paradigm. It provided (1) a straightforward measure of transient responses in presence of open loop visual stimulation; (2) high data throughput and standardized measurement conditions from process automation; and (3) simplified data analysis due to well-defined testing conditions. Being based on standard hardware and software techniques, our methods provide an affordable, easy to replicate and general solution for a broad range of behavioral applications in freely moving animals. Particular relevance for advanced behavioral research tools originates from the need to perform detailed behavioral analyses in genetically modified organisms and animal models for disease research.

  20. 大掺量粉煤灰混凝土在海水中冻融循环后的试验研究%Experimental research on the freezing-thawing circle of high volume fly ash concrete in seawater

    Institute of Scientific and Technical Information of China (English)

    覃丽坤; 宋宏伟; 王秀伟

    2014-01-01

    为研究粉煤灰混凝土的抗冻性能,研究了水胶比为0.35,粉煤灰掺量为52%的大掺量粉煤灰混凝土在海水中的抗冻性能,利用混凝土快速冻融试验机,对海水中粉煤灰混凝土分别进行了0、100、200、300、400次快速冻融循环试验,并对冻融循环后的混凝土进行了单轴压力学性能试验。测得了冻融循环后混凝土的质量损失,动弹性模量以及单轴抗压强度。根据试验结果,系统地分析了冻融循环次数对大掺量粉煤灰混凝土单轴抗压强度的影响。结论表明:随冻融循环次数的增加,海水中大掺量粉煤灰混凝土的单轴强度逐渐降低,并具有一定规律性。这些结论可以为粉煤灰混凝土在寒冷地区海工混凝土构筑物的应用提供理论依据。%In order to study on frost resistance of fly ash concrete.The authors using the rapid freezing and thawing of concrete test ma-chine,tested the frost resistance performance of high volume fly ash concrete in seawater,whose water-binder ratio was 0.35,the amount of fly ash was 52%.The fast freezing-thawing test was carried on 0、100、200、300 and 400 cycles,then uniaxial compression test,the mass loss after freezing-thawing cycles,the dynamic elastic modulus and uniaxial compressive strength were tested.According to the test results, the systematic analysis of the influence of freezing-thawing cycles on the uniaxial compressive strength of high volume fly ash concrete. Conclusion:with the increase in the number of freezing-thawing cycles,the uniaxial strength mixed with high volume fly ash concrete in seawater decreased gradually,and which has certain regularity.These conclusions can provide a theoretical basis for the application of fly ash concrete in cold area of marine concrete qstructures.

  1. Flying over decades

    Science.gov (United States)

    Hoeller, Judith; Issler, Mena; Imamoglu, Atac

    Levy flights haven been extensively used in the past three decades to describe non-Brownian motion of particles. In this presentation I give an overview on how Levy flights have been used across several disciplines, ranging from biology to finance to physics. In our publication we describe how a single electron spin 'flies' when captured in quantum dot using the central spin model. At last I motivate the use of Levy flights for the description of anomalous diffusion in modern experiments, concretely to describe the lifetimes of quasi-particles in Josephson junctions. Finished PhD at ETH in Spring 2015.

  2. Vision in flying insects.

    Science.gov (United States)

    Egelhaaf, Martin; Kern, Roland

    2002-12-01

    Vision guides flight behaviour in numerous insects. Despite their small brain, insects easily outperform current man-made autonomous vehicles in many respects. Examples are the virtuosic chasing manoeuvres male flies perform as part of their mating behaviour and the ability of bees to assess, on the basis of visual motion cues, the distance travelled in a novel environment. Analyses at both the behavioural and neuronal levels are beginning to unveil reasons for such extraordinary capabilities of insects. One recipe for their success is the adaptation of visual information processing to the specific requirements of the behavioural tasks and to the specific spatiotemporal properties of the natural input.

  3. Feasibility study on solidification of municipal solid waste incinerator fly ash with circulating fluidized bed combustion coal fly ash.

    Science.gov (United States)

    Liu, Wenshi; Hou, Haobo; Zhang, Chuhao; Zhang, Dajie

    2009-05-01

    The objective of this study was to assess the feasibility of solidification of municipal solid waste incinerator (MSWI) fly ash with circulation fluidized bed combustion (CFBC) fly ash, which is unsuitable as a cement replacement due to its high amounts of carbon, lime and anhydrite. The solidification process was conducted on samples prepared from MSWI fly ash, binders (cement clinkers and CFBC fly ash were mixed at two replacement ratios) and water (water/solid weight ratio = 0.4), among which the MSWI fly ash replaced each binder at the ratio of 0, 20, 40, 60 and 80% by dry weight. The samples were subjected to compressive strength tests and Toxicity Characteristic Leaching Procedure and the results showed that all solidified MSWI fly ash can meet the landfill standard imposed by US EPA after 28 days of curing. Micro-analysis (X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrophotometry) revealed that the main hydrate products were C-S-H gel and ettringite, which have a positive effect on heavy metals retention. Therefore, this method provides a possibility to achieve a cheap and effective solution for MSWI fly ash management and use for CFBC fly ash.

  4. 纤维、粉煤灰复合高性能道面混凝土试验研究%Test study on fiber and fly powder conplex high performance pavement concrete

    Institute of Scientific and Technical Information of China (English)

    殷民动; 李光元

    2012-01-01

    Common airfield pavement concrete is poor endurable performance and easy craze in north cold and aridity area. This paper produce high performance pavement concrete by adding fiber and fly powder,it fit cold and aridity environment. Tests show:fiber or fly powder can raise the concrete performance of and craze,anti seep,anti freeze and anti-abrade. Especially when fiber and fly-powder are added together,super repeat domino effect can produced,synthesis performance can be advanced.%针对目前北方寒冷干旱地区普通道面混凝土耐久性差、易开裂的现象,通过在普通混凝土中掺纤维或粉煤灰以及纤维与粉煤灰双掺的技术路线,研究配制了适合寒冷干旱地区的高性能道面混凝土,并进行了相应的抗裂性、耐久性试验.研究结果表明,纤维或粉煤灰均能提高混凝土的抗裂、抗渗、抗冻、耐磨性能,尤其是纤维与粉煤灰复合产生了1+1>2的超叠加综合效应,更能够全面地提高道面混凝土的综合耐久性能.

  5. Sectional lift coefficient of a rotating wing at low Reynolds numbers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Eun [Hyundai Motor Company, Hwaseong (Korea, Republic of); Kweon, Ji Hoon [Asan Medical Center, Seoul (Korea, Republic of); Choi, Hae Cheon [Seoul National University, Seoul (Korea, Republic of)

    2015-11-15

    We study the characteristics of the sectional lift coefficient (C{sub L,S}) of low-aspect-ratio wings in rotating motion at low Reynolds number (Re = 136), by conducting three-dimensional numerical simulations. Three different shapes of thin-plate wings (fruit-fly, rectangular, and triangular wings) are considered but keeping their aspect ratio (wing span/wing chord) the same at 3.74. Each wing rotates at a constant angular velocity and the angle of attack (α) is fixed during rotation. During rotation, the wing is exposed to the downward flows generated from the previous rotation, and thus C{sub L,S} is overall reduced due to the decrease in the effective angle of attack. At low α's, C{sub L,S} becomes almost constant on the whole span. At high α's, C{sub L,S} on the wing mid-section is inversely proportional to the radial position. The radial distribution of the sectional lift coefficient is less affected by the wing planform, while the lift coefficient significantly depends on the wing planforms. Finally, we show that the effect of the Reynolds number on the sectional lift coefficient is insignificant at low angle of attack but becomes important at high angle of attack.

  6. Fly ash quality and utilization

    Energy Technology Data Exchange (ETDEWEB)

    Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  7. Fly-ash lobby design to convert the sceptics

    Energy Technology Data Exchange (ETDEWEB)

    Bile, P.

    1983-07-14

    New uses for pfa in structural concrete have been pioneered at Didcot power station. Twenty percent cost savings and significant gains in long-term strength are claimed for the new concrete, called high fly-ash content concrete (HFCC).

  8. Physics of flying

    Science.gov (United States)

    Vetrone, Jim

    2015-05-01

    Column editor's note: As the school year comes to a close, it is important to start thinking about next year. One area that you want to consider is field trips. Many institutions require that teachers plan for a field trip well in advance. Keeping that in mind, I asked Jim Vetrone to write an article about the fantastic field trip he takes his AP Physics students on. I had the awesome opportunity to attend a professional development day that Jim arranged at iFLY in the Chicago suburbs. The experience of "flying" in a wind tunnel was fabulous. Equally fun was watching the other physics teachers come up with experiments to have the professional "flyers" perform in the tube. I could envision my students being similarly excited about the experience and about the development of their own experiments. After I returned to school, I immediately began the process of trying to get this field trip approved for the 2015-16 school year. I suggest that you start your process as well if you hope to try a new field trip next year. The key to getting the approval, in my experience, is submitting a proposal early that includes supporting documentation from sources. Often I use NGSS or state standards as justifications for my field trips. I have also quoted College Board expectations for AP Physics 1 and 2 in my documents when requesting an unusual field trip.quote>

  9. 大掺量粉煤灰混凝土导温系数试验研究%Experimental Research on the Thermal Diffusivity of High Content Fly-ash Concrete

    Institute of Scientific and Technical Information of China (English)

    孙阳; 娄宗科; 朱为勇

    2014-01-01

    In order to study the thermal conductivity of high volume of fly ash concrete ,the changing rule of the thermal conductivity of concrete is quantitatively investigated by the orthogonal test .Such testing variables as the fly ash content ,water-cement ratio , sand ratio ,water reducing agent dosage and aggregate concrete of dry and wet condition are considered in this test .The results indi-cate that sand ratio ,the content of fly ash and water reducing agent are the significant factors .The significance of these factors is as follows :sand ratio ,fly ash ,water reducing agent dosage ,aggregate concrete of dry and wet condition ,water-cement ratio .Based on the optimal combination of the maximum and minimum of thermal conductivity ,a reference is provided for the estimated thermal dif-fusivity by the regression equation regression analysis .%为研究大掺量粉煤灰混凝土的导温系数,本文利用正交试验测定在粉煤灰掺量、水胶比、砂率、减水剂掺量以及骨料干湿状态5个因素影响下混凝土导温系数的变化规律。结果表明:各因素均为混凝土导温系数的显著性影响因素,其中砂率、粉煤灰和减水剂掺量为极显著影响因素,各因素的影响顺序为:砂率>粉煤灰掺量>减水剂掺量>>骨料干湿状态>水胶比,并得到导温系数取得最大和最小时的最优配合比,最后应用回归分析得到回归方程,为大掺量粉煤灰混凝土导温系数的预估提供参考。

  10. Functional genomics of the horn fly, Haematobia irritans (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Quiroz-Romero Héctor

    2011-02-01

    Full Text Available Abstract Background The horn fly, Haematobia irritans (Linnaeus, 1758 (Diptera: Muscidae is one of the most important ectoparasites of pastured cattle. Horn flies infestations reduce cattle weight gain and milk production. Additionally, horn flies are mechanical vectors of different pathogens that cause disease in cattle. The aim of this study was to conduct a functional genomics study in female horn flies using Expressed Sequence Tags (EST analysis and RNA interference (RNAi. Results A cDNA library was made from whole abdominal tissues collected from partially fed adult female horn flies. High quality horn fly ESTs (2,160 were sequenced and assembled into 992 unigenes (178 contigs and 814 singlets representing molecular functions such as serine proteases, cell metabolism, mitochondrial function, transcription and translation, transport, chromatin structure, vitellogenesis, cytoskeleton, DNA replication, cell response to stress and infection, cell proliferation and cell-cell interactions, intracellular trafficking and secretion, and development. Functional analyses were conducted using RNAi for the first time in horn flies. Gene knockdown by RNAi resulted in higher horn fly mortality (protease inhibitor functional group, reduced oviposition (vitellogenin, ferritin and vATPase groups or both (immune response and 5'-NUC groups when compared to controls. Silencing of ubiquitination ESTs did not affect horn fly mortality and ovisposition while gene knockdown in the ferritin and vATPse functional groups reduced mortality when compared to controls. Conclusions These results advanced the molecular characterization of this important ectoparasite and suggested candidate protective antigens for the development of vaccines for the control of horn fly infestations.

  11. Performance of fly ash concretes in accelerated and natural chloride exposure regimes

    Energy Technology Data Exchange (ETDEWEB)

    Sorn, V.; Oshiro, T.; Yamada, Y. [Ryukyus Univ., Okinawa (Japan). Dept. of Civil Engineering and Architecture; Sugiyama, T. [Gunma Univ. (Japan). Dept. of Civil Engineering; Matsufuji, Y. [Kyusyu Univ. (Japan). Dept. of Architecture

    2001-07-01

    Serious effort has been made in Japan to make use of the huge quantity of fly ash that is generated each year by coal-based thermal power plants. The produced fly ash contains unburned carbon, rendering it a low quality material classified as Japan Industrial Standard A 6201 class 3. The most efficient use of this kind of fly ash is to use it in concrete, where fly ash is added to the concrete without a corresponding reduction in the quantity of cement. A study was conducted to examine the penetrating characteristics of chloride ions into fly ash concrete and the corrosion of steel reinforcement in concrete, where portions of fine and coarse aggregates were replaced by fly ash. Compressive strength tests were conducted along with chloride penetration tests. Corrosion diagnosis of steel reinforcements was also performed. The physical properties and durability of fly ash concrete against aggressive environments was studied. It was determined that fly ash concretes have higher compressive strength than the control concrete. The strength development of fly ash concrete is very large, particularly on high-volume fly ash concretes. Chloride diffusion coefficients of fly ash concretes derived from the rapid chloride permeability test were found to decrease according to the volume of fly ash added. Chloride penetration of fly ash concretes also decreases with an increase in the volume of fly ash added. Corrosion diagnosis of steel reinforcement in concrete was shown to be effective for evaluating corrosive behaviour of steel reinforcement in fly ash concretes. The values of half-cell potential and polarization resistance measured on fly ash concretes become higher, suggesting no corrosion on steel reinforcement. 6 refs., 4 tabs., 10 figs.

  12. High-resolution GPS tracking reveals habitat selection and the potential for long-distance seed dispersal by Madagascan flying foxes Pteropus rufus

    Directory of Open Access Journals (Sweden)

    Ryszard Oleksy

    2015-01-01

    Full Text Available Long-distance seed dispersal can be important for the regeneration of forested habitats, especially in regions where deforestation has been severe. Old World fruit bats (Pteropodidae have considerable potential for long-distance seed dispersal. We studied the movement patterns and feeding behaviour of the endemic Madagascan flying fox Pteropus rufus, in Berenty Reserve, southeast Madagascar. Between July and September 2012 (the dry season nine males and six females were tagged with customised GPS loggers which recorded fixes every 2.5 min between 18.00 and 06.00 h. The combined home range of all of the tagged bats during 86 nights exceeded 58,000 ha. Females had larger home ranges and core foraging areas and foraged over longer distances (average 28.1 km; median 26.7 km than males (average 15.4 km; median 9.5 km. Because the study was conducted during the gestation period, the increased energy requirements of females may explain their greater mean foraging area. Compositional analysis revealed that bats show strong preferences for overgrown sisal (Agave sisalana plantations (a mix of shrub, trees and sisal plants and remnant riverside forest patches. Sisal nectar and pollen were abundant food sources during the tracking period and this probably contributed to the selective use of overgrown sisal plantations. The bats also ate large quantities of figs (Ficus grevei during the study, and dispersed seeds of this important pioneer species. The bats flew at an average speed of 9.13 m/s, perhaps to optimise gliding performance. The study confirms that P. rufus has the potential to be a long-distance seed disperser, and is able to fly over a large area, often crossing cleared parts of its habitat. It potentially plays an important role in the regeneration of threatened forest habitats in this biodiversity hotspot.

  13. Nonlinear feedback control of highly manoeuvrable aircraft

    Science.gov (United States)

    Garrard, William L.; Enns, Dale F.; Snell, S. A.

    1992-01-01

    This paper describes the application of nonlinear quadratic regulator (NLQR) theory to the design of control laws for a typical high-performance aircraft. The NLQR controller design is performed using truncated solutions of the Hamilton-Jacobi-Bellman equation of optimal control theory. The performance of the NLQR controller is compared with the performance of a conventional P + I gain scheduled controller designed by applying standard frequency response techniques to the equations of motion of the aircraft linearized at various angles of attack. Both techniques result in control laws which are very similar in structure to one another and which yield similar performance. The results of applying both control laws to a high-g vertical turn are illustrated by nonlinear simulation.

  14. Refractive Index of Fly Rhabdomeres

    NARCIS (Netherlands)

    Stavenga, D.G.

    1974-01-01

    The refractive index reported previously for the rhabdomeres of flies (1.349) has been corrected for waveguide effects. The presented correction method has yielded n1 = 1.365 ± 0.006. It is argued that an acceptable estimate for the refractive index of the inhomogeneous surroundings of fly

  15. Classical olfactory conditioning in the oriental fruit fly, Bactrocera dorsalis.

    Science.gov (United States)

    Liu, Jia Li; Chen, Xiao Yan; Zeng, Xin Nian

    2015-01-01

    The oriental fruit fly, Bactrocera dorsalis, is a serious pest of fruits and vegetables. Methyl eugenol (ME), a male attractant, is used to against this fly by mass trapping. Control effect may be influenced by learning, which could modify the olfactory response of the fly to this attractant. To collect the behavioral evidence, studies on the capability of this fly for olfactory learning are necessary. We investigated olfactory learning in male flies with a classical olfactory conditioning procedure using restrained individuals under laboratory conditions. The acquisition of the proboscis extension reflex was used as the criterion for conditioning. A high conditioned response level was found in oriental fruit flies when an odor was presented in paired association with a sucrose reward but not when the odor and sucrose were presented unpaired. We also found that the conditioning performance was influenced by the odor concentration, intertrial interval, and starvation time. A slight sensitization elicited by imbibing sucrose was observed. These results indicate that oriental fruit flies have a high capacity to form an olfactory memory as a result of classical conditioning.

  16. Inertia may limit efficiency of slow flapping flight, but mayflies show a strategy for reducing the power requirements of loiter

    Energy Technology Data Exchange (ETDEWEB)

    Usherwood, James R [Structure and Motion Lab., Royal Veterinary College, North Mymms, Hatfield, Herts AL9 7TA (United Kingdom)], E-mail: jusherwood@rvc.ac.uk

    2009-03-01

    Predictions from aerodynamic theory often match biological observations very poorly. Many insects and several bird species habitually hover, frequently flying at low advance ratios. Taking helicopter-based aerodynamic theory, wings functioning predominantly for hovering, even for quite small insects, should operate at low angles of attack. However, insect wings operate at very high angles of attack during hovering; reduction in angle of attack should result in considerable energetic savings. Here, I consider the possibility that selection of kinematics is constrained from being aerodynamically optimal due to the inertial power requirements of flapping. Potential increases in aerodynamic efficiency with lower angles of attack during hovering may be outweighed by increases in inertial power due to the associated increases in flapping frequency. For simple hovering, traditional rotary-winged helicopter-like micro air vehicles would be more efficient than their flapping biomimetic counterparts. However, flapping may confer advantages in terms of top speed and manoeuvrability. If flapping-winged micro air vehicles are required to hover or loiter more efficiently, dragonflies and mayflies suggest biomimetic solutions.

  17. Trapping tsetse flies on water

    Directory of Open Access Journals (Sweden)

    Laveissière C.

    2011-05-01

    Full Text Available Riverine tsetse flies such as Glossina palpalis gambiensis and G. tachinoides are the vectors of human and animal trypanosomoses in West Africa. Despite intimate links between tsetse and water, to our knowledge there has never been any attempt to design trapping devices that would catch tsetse on water. In mangrove (Guinea one challenging issue is the tide, because height above the ground for a trap is a key factor affecting tsetse catches. The trap was mounted on the remains of an old wooden dugout, and attached with rope to nearby branches, thereby allowing it to rise and fall with the tide. Catches showed a very high density of 93.9 flies/”water-trap”/day, which was significantly higher (p < 0.05 than all the catches from other habitats where the classical trap had been used. In savannah, on the Comoe river of South Burkina Faso, the biconical trap was mounted on a small wooden raft anchored to a stone, and catches were compared with the classical biconical trap put on the shores. G. p. gambiensis and G. tachinoides densities were not significantly different from those from the classical biconical one. The adaptations described here have allowed to efficiently catch tsetse on the water, which to our knowledge is reported here for the first time. This represents a great progress and opens new opportunities to undertake studies on the vectors of trypanosomoses in mangrove areas of Guinea, which are currently the areas showing the highest prevalences of sleeping sickness in West Africa. It also has huge potential for tsetse control using insecticide impregnated traps in savannah areas where traps become less efficient in rainy season. The Guinean National control programme has already expressed its willingness to use such modified traps in its control campaigns in Guinea, as has the national PATTEC programme in Burkina Faso during rainy season.

  18. Entomopathogenic Fungi in Flies Associated with Pastured Cattle in Denmark

    DEFF Research Database (Denmark)

    Steenberg, Tove; Jespersen, Jørgen B.; Jensen, Karl-Martin Vagn;

    2001-01-01

    in the Entomophthora muscae species complex (E. muscae sensu lato) caused high infection levels in several species of flies. However, only a few specimens of cattle flies were infected by E. muscae sensu stricto despite the fact that cattle flies were observed to perch on spear thistles, which acted as transmission...... site for all four Entomophthora species. Transmission experiments with E. muscae s.l. supported the field data. Of the two species considered host specific, E. syrphi caused substantial infection in a muscid, and E. scatophagae likewise could be transmitted to a muscid. This emphasizes the need...

  19. Usage of fly ash as a coal desulphurization reagent

    Energy Technology Data Exchange (ETDEWEB)

    Yaman, S.; Kuecuekbayrak, S. [Istanbul Technical Univ. (Turkey). Chemical and Metallurgical Engineering Faculty

    1996-12-31

    This paper covers the direct usage of fly ash to remove sulphur from coal. Experiments were carried out on a high sulphur Turkish lignite. 5 g of fly ash was extracted in 200 ml of water under pressure and the dilute solution containing water extractable parts of fly ash was used as desulphurization reagent. Oxygen pressure was created over desulphurization medium during the extraction period by which dissolved oxygen was concentrated in the solution. Effects of temperature, partial pressure of oxygen, and time were investigated in the ranges of 403--498 K, 0.0--1.5 MPa and 15--90 min, respectively.

  20. Electrodialytic removal of Cd from biomass combustion fly ash

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

    2004-01-01

    Due to a high concentration of Cd, biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. In this work the potential of using the method Electrodialytic Remediation to reduce the concentration of Cd in different biomass combustion...... fly ashes was studied. Four fly ashes were investigated, originating from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. One of the straw ashes had been pre-washed and was obtained suspended in water, the other ashes were obtained naturally dry...

  1. Pure zeolite synthesis from silica extracted from coal fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, N.; Querol, X.; Plana, F.; Andres, J.M.; Janssen, M.; Nugteren, H. [CSIC, Barcelona (Spain). Inst. Earth Science ' Jaume Almera'

    2002-07-01

    Pure zeolites can be synthesised from silica extracted from fly ash by alkaline leaching. If the process is optimised the solid residue arising from this extraction may also contain a relatively high content of zeolitic material mixed with residual fly ash components. Both the pure and the impure zeolitic material have a high potential for application in waste-water and flue gas-cleaning technologies. The silica extraction potential of 23 European coal fly ashes covering most of the possible fly ash types is investigated in this study. Optimisation of leaching processes, by varying temperature, time and alkali/fly ash rates, permitted extraction yields up to 140 g of SiO{sub 2} per kg using a single step process, but the extraction yields may reach up to 210 g kg{sup -1} by applying thermal pre-treatments prior to the extraction. The solid residue arising from the silica extraction experiments shows a high NaP1 zeolite content. A high Si/Al ratio of the glass matrix, the occurrence of easily soluble silica phases in the original fly ash and a high reactive surface area were found to be the major parameters influencing silica extraction. High purity 4A and X zeolitic material was obtained by combining the silica extracts from the Meirama fly ash and a waste solution from the Al-anodising industry. The results allowed conversion of the silica extraction yields to an equivalent 630 g of pure 4A-X zeolite per kg of fly ash with a cation exchange capacity of 4.7 meq g{sup -1}.

  2. Extraction of vanadium from athabasca tar sands fly ash

    Science.gov (United States)

    Gomez-Bueno, C. O.; Spink, D. R.; Rempel, G. L.

    1981-06-01

    The production of refinery grade oil from the Alberta tar sands deposits as currently practiced by Suncor (formally Great Canadian Oil Sands Ltd.—GCOS) generates a substantial amount of petroleum coke fly ash which contains appreciable amounts of valuable metals such as vanadium, nickel and titanium. Although the recovery of vanadium from petroleum ash is a well established commercial practice, it is shown in the present work that such processes are not suitable for recovery of vanadium from the GCOS fly ash. The fact that the GCOS fly ash behaves so differently when compared to other petroleum fly ash is attributed to its high silicon and aluminum contents which tie up the metal values in a silica-alumina matrix. Results of experiments carried out in this investigation indicate that such matrices can be broken down by application of a sodium chloride/water roast of the carbon-free fly ash. Based on results from a series of preliminary studies, a detailed investigation was undertaken in order to define optimum conditions for a vanadium extraction process. The process developed involves a high temperature (875 to 950 °C) roasting of the fly ash in the presence of sodium chloride and water vapor carried out in a rotary screw kiln, followed by dilute sodium hydroxide atmosphereic leaching (98 °C) to solublize about 85 pet of the vanadium originally present in the fly ash. It was found that the salt roasting operation, besides enhancing vanadium recovery, also inhibits silicon dissolution during the subsequent leaching step. The salt roasting treatment is found to improve vanadium recovery significantly when the fly ash is fully oxidized. This is easily achieved by burning off the carbon present in the “as received” fly ash under excess air. The basic leaching used in the new process selectively dissolves vanadium from the roasted ash, leaving nickel and titanium untouched.

  3. Potential fly-ash utilization in agriculture: A global review

    Institute of Scientific and Technical Information of China (English)

    Manisha Basu; Manish Pande; P.B.S. Bhadoria; S.C. Mahapatra

    2009-01-01

    Though in last four decades various alternate energy sources have come into the limelight, the hyperbolic use of coal as a prime energy source cannot be counterbalanced. Disposal of high amount of fly-ash from thermal power plants absorbs huge amount of water, energy and land area by ash ponds. In order to meet the growing energy demand, various environmental, economic and social problems associated with the disposal of fly-ash would continue to increase. Therefore, fly-ash management would remain a great concern of the century. Fly-ash has great potentiality in agriculture due to its efficacy in modification of soil health and crop performance. The high concentration of elements (K, Na, Zn, Ca, Mg and Fe) in fly-ash increases the yield of many agricultural crops. But compared to other sectors, the use of fly-ash in agriculture is limited. An exhaustive review of numerous studies of last four decades took place in this paper, which systematically covers the importance, scope and apprehension regarding utilization of fly-ash in agriculture. The authors concluded that though studies have established some solutions to handle the problems of radioactivity and heavy metal content in flyash, long-term confirmatory research and demonstration are necessary. This paper also identified some areas, like proper handling of dry ash in plants as well as in fields, ash pond management (i.e., faster decantation, recycling of water, vertical expansion rather than horizontal), monitoring of soil health, crop quality, and fate of fly-ash in time domain, where research thrust is required. Agricultural lime application contributes to global warming as Intergovernmental Panel on Climate Change (IPCC) assumes that all the carbon in agricultural lime is finally released as CO2to the atmosphere. It is expected that use of fly-ash instead of lime in agriculture can reduce net CO2emission, thus reduce global warming also.

  4. Adaptive Missile Flight Control for Complex Aerodynamic Phenomena

    Science.gov (United States)

    2017-08-09

    e.g., top -right fin at beginning of animation while the vehicle is at a high angle of attack). These data illustrate these complex aerodynamic...optimal controllers. The poor roll control performance of the optimal controller means that the airframe flies at those aerodynamic angles while spinning ...corrected spinning projectile. J Spacecraft Rockets. 1975;12(12):733–738. 2. Chandgadkar S, Costello M, Dano B, Liburdy J, Pence D. Performance of a

  5. Environmental hazard of oil shale combustion fly ash.

    Science.gov (United States)

    Blinova, Irina; Bityukova, Liidia; Kasemets, Kaja; Ivask, Angela; Käkinen, Aleksandr; Kurvet, Imbi; Bondarenko, Olesja; Kanarbik, Liina; Sihtmäe, Mariliis; Aruoja, Villem; Schvede, Hedi; Kahru, Anne

    2012-08-30

    The combined chemical and ecotoxicological characterization of oil shale combustion fly ash was performed. Ash was sampled from the most distant point of the ash-separation systems of the Balti and Eesti Thermal Power Plants in North-Eastern Estonia. The fly ash proved potentially hazardous for tested aquatic organisms and high alkalinity of the leachates (pH>10) is apparently the key factor determining its toxicity. The leachates were not genotoxic in the Ames assay. Also, the analysis showed that despite long-term intensive oil-shale combustion accompanied by considerable fly ash emissions has not led to significant soil contamination by hazardous trace elements in North-Eastern Estonia. Comparative study of the fly ash originating from the 'new' circulating fluidized bed (CFB) combustion technology and the 'old' pulverized-fired (PF) one showed that CFB fly ash was less toxic than PF fly ash. Thus, complete transfer to the 'new' technology will reduce (i) atmospheric emission of hazardous trace elements and (ii) fly ash toxicity to aquatic organisms as compared with the 'old' technology. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Focus characteristics of long distance flying optics

    Institute of Scientific and Technical Information of China (English)

    程兆谷; 蒋金波; 李现勤; 许国良; 夏金安; W.M.Steen; G.Dearden

    2000-01-01

    The ABCD law for the complex parameter q of the TEM00 Gaussian beam is generally not valid for high-order modes. It can be used for the high-order modes or their superposition when the spot size w in the virtual part of the parameter q is substituted by the Rayleigh range ZR of a certain resonator. The focus characteristics of long distance flying optics are studied in this paper theoretically and experimentally for the TEMmn Gaussian beams between the two types of resonators without and with distortion. It is very important for the applications of the flying optical processing, the laser space craft and the spatial filter in the large laser project.

  7. Fauna and relative frequency of synanthropic flies in the biggest Persian Gulf Island, Qeshm, Iran

    Directory of Open Access Journals (Sweden)

    Mehdi Khoobdel

    2015-09-01

    Full Text Available Objective: To identify the diversity and relative abundance of medically important species of synanthropic flies and their seasonal activity on Qeshm Island in Persian Gulf, Iran. Methods: Flies collection was performed during March 2011 to February 2012 in all different areas of the island by using the common fly trap and plastic water bottle fly trap, reverse-cone model, containing tainted lamb or beef meat as bait. The captured flies were identified by using valid flies systematic keys, checklists and species description. The relative abundances and seasonal activity of flies were estimated by means of flies captured per trap in every month. Results: In this study a total number of 11 species of medically important flies in three families including Calliphoridae, Sarcophagidae and Muscidae, were collected. The relative mean abundance of flies was estimated to be 6.3 ± 1.1 per trap. The most abundance was seen in rural areas in the south of Qeshm Island with 10.1 ± 1.5 per trap. In this island, medically impotent flies had two peaks of activity in early spring and early autumn, during April and October. Flies activity decreased in July and August due to the high increase of temperature and humidity of the weather. In February, the relative decrease in air temperature reduced the activity of the flies. Conclusions: Diversity and abundance of flies in spring and early autumn were higher than other seasons, especially in rural areas of Southern Qeshm Island. Insect control measures should be conducted during the peak of flies activity.

  8. Fauna and relative frequency of synanthropic flies in the biggest Persian Gulf Island, Qeshm, Iran

    Institute of Scientific and Technical Information of China (English)

    Mehdi Khoobdel; Kamran Akbarzadeh; Javad Rafinejad

    2015-01-01

    Objective: To identify the diversity and relative abundance of medically important species of synanthropic flies and their seasonal activity on Qeshm Island in Persian Gulf, Iran. Methods: Flies collection was performed during March 2011 to February 2012 in all different areas of the island by using the common fly trap and plastic water bottle fly trap, reverse-cone model, containing tainted lamb or beef meat as bait. The captured flies were identified by using valid flies systematic keys, checklists and species description. The relative abundances and seasonal activity of flies were estimated by means of flies captured per trap in every month. Results: In this study a total number of 11 species of medically important flies in three families including Calliphoridae, Sarcophagidae and Muscidae, were collected. The relative mean abundance of flies was estimated to be 6.3 ± 1.1 per trap. The most abundance was seen in rural areas in the south of Qeshm Island with 10.1 ± 1.5 per trap. In this island, medically impotent flies had two peaks of activity in early spring and early autumn, during April and October. Flies activity decreased in July and August due to the high increase of temperature and humidity of the weather. In February, the relative decrease in air temperature reduced the activity of the flies. Conclusions: Diversity and abundance of flies in spring and early autumn were higher than other seasons, especially in rural areas of Southern Qeshm Island. Insect control measures should be conducted during the peak of flies activity.

  9. Effects of elevated temperatures on the mechanical properties of high fly ash content concrete%高温作用对大掺量粉煤灰混凝土力学性能影响

    Institute of Scientific and Technical Information of China (English)

    贾福萍; 崔艳莉; 孙宜兵; 程勇

    2011-01-01

    In this paper, the effects of elevated temperatures on the mechanical properties of high fly ash content concrete (HFCC) are presented. The specimens were prepared with three different replacements of cement by fly ash 30%,40% and 50% and were tested after exposure to elevated temperature 250, 450, 550 and 650°C respectively, compared with plain Portland concrete. The results showed that as the elevated temperature increases, the residual compressive strength and the residual tensile strength both apparently decrease and the deterioration of tensile strength was much quicker than the deterioration in compressive strength. The results also showed the influence of fly ash replacement on the degraded ratio of strength is complicated. After an exposure to the elevated temperatures, the degraded ratio of compressive strength is less than plain ordinary Portland concrete (PC) and one of tensile strength, except 30% fly ash replacement, remains the same. Based on the experiments, the alternating simulation formula for determining the relationship between residual strength ratio, elevated temperature and fly ash, the replacement is developed by using regression of results, which provide the theoretical basis for the evaluation and repair of HFCC after elevated temperature.%研究了高温作用对大掺量粉煤灰混凝土(HFCC)立方体力学性能的影响,探讨了不同加热温度、不同粉煤灰掺量与HFCC残余强度的关系.将粉煤灰掺量30%、40%和50%的混凝土立方体试块加热至250,450,550和650℃进行强度测试,并与素混凝土(不掺粉煤灰)试块进行对比.研究结果表明,随着温度升高,HFCC残余抗压、劈裂抗拉强度均出现明显退化,劈裂抗拉强度退化尤为明显;随着粉煤灰的掺入,粉煤灰掺量对强度退化率的影响具有复杂性:高温后HFCC抗压强度退化率均低于普通混凝土强度退化率;劈裂抗拉强度退化率除粉煤灰掺量30%外均低于普通混凝土退化

  10. Burn Injury Arise From Flying Balloon Toys

    OpenAIRE

    Yalcin Kulahci; Fatih Zor; Mehmet Bozkurt; Serdar Ozturk; Mustafa Sengezer

    2007-01-01

    Many of peoples are faced minor or major burn injuries in their life. Even the most widespread burn cause is flame injuries, too different burn cause pointed out in literature like Acetylen burns. The cases which imply in literature, mostly causes from explosion of high pressure acetylene tube, metal oxygene patch flame or carbide lamp using from cave explorers. An interesting acetylene burn cause in Turkey was publised by the authors. This cases was to come into being from flying toy balloon...

  11. Influence of fly ash and desert Sand content on the compressive strength of high strength concrete%掺粉煤灰、沙漠砂高强混凝土抗压强度研究

    Institute of Scientific and Technical Information of China (English)

    陈云龙; 马菊荣; 刘海峰; 宋建夏

    2014-01-01

    The orthogonal experiment was designed to analyze the influence of water-binder ratio,fly ash content,sand ratio and desert sand replacement ratio on the compressive strength of high strength concrete at the different age.The optimum mix ratio of desert sand high-strength concrete was also given out.Experimental result showed that it is practical to use the desert sand from Mu Us desert sand to mix high strength concrete,the optimum mix ratio of which was that water-binder ratio,fly ash dosage,sand ratio and desert sand replace-ment ratio were 0.24,10%,30% and 30%,respectively.%通过正交试验,分析了水胶比、粉煤灰掺量、砂率、沙漠砂取代率对不同龄期高强混凝土抗压强度影响,并给出了配制高强混凝土的最优配合比。研究结果表明:用沙漠砂替代中砂配制高强混凝土是可行的;综合考虑各阶段的抗压强度,高强混凝土的最优配合比为水胶比0.24、粉煤灰掺量10%、砂率30%、沙漠砂取代率30%。

  12. Roll Control in Fruit Flies

    CERN Document Server

    Beatus, Tsevi; Cohen, Itai

    2014-01-01

    Due to aerodynamic instabilities, stabilizing flapping flight requires ever-present fast corrective actions. Here we investigate how flies control body roll angle, their most susceptible degree of freedom. We glue a magnet to each fly, apply a short magnetic pulse that rolls it in mid-air, and film the corrective maneuver. Flies correct perturbations of up to $100^{\\circ}$ within $30\\pm7\\mathrm{ms}$ by applying a stroke-amplitude asymmetry that is well described by a linear PI controller. The response latency is $\\sim5\\mathrm{ms}$, making the roll correction reflex one of the fastest in the animal kingdom.

  13. Symbiotic bacteria enable olive fly larvae to overcome host defences

    OpenAIRE

    Ben-Yosef, Michael; Pasternak, Zohar; Jurkevitch, Edouard; Yuval, Boaz

    2015-01-01

    Ripe fruit offer readily available nutrients for many animals, including fruit fly larvae (Diptera: Tephritidae) and their associated rot-inducing bacteria. Yet, during most of their ontogeny, fruit remain chemically defended and effectively suppress herbivores and pathogens by high levels of secondary metabolites. Olive flies (Bactrocera oleae) are uniquely able to develop in unripe olives. Unlike other frugivorous tephritids, the larvae maintain bacteria confined within their midgut caeca. ...

  14. Engineering Properties of Alkali-Activated Fly Ash Concrete

    OpenAIRE

    2006-01-01

    This paper reports the results of experimental research on certain engineering properties of a new (portland cement-free) concrete made with alkali-activated fly ash. Laboratory tests were conducted to determine its (bending and compression) mechanical strength, modulus of elasticity, bond strength, and shrinkage. The results show that mortar and concrete made with portland cement-free activated fly ash develop a high mechanical strength in short periods of time, have a moderate modulus of el...

  15. Application of mathematical model for high-temperature resistance of fly ash geopolymers%地聚物固化体抗高温性能及数学模型研究

    Institute of Scientific and Technical Information of China (English)

    金漫彤; 黄彩菊; 邵江平; 许杭俊; 王连军

    2011-01-01

    地聚物对焚烧飞灰中的重金属具有良好的固定作用.为了进一步探索固化飞灰后的地聚物固化体的抗环境侵蚀性能,开展了固化体高温-恒温时间-地聚物抗压强度的研究及经受高温后固化体的重金属浸出试验,探讨抗压强度与高温、恒温时间之间的关系以及地聚物固化垃圾焚烧飞灰的稳定性.通过对固化体试块的高温试验以及对不同温度、不同恒温时间下固化体抗压强度试验,分析这三者之间的关系,建立数学模型,并根据实验结果拟合温度-恒温时间-抗压强度的三维曲面.%Geopolymers can effectively immobilize the heavy metals in the municipal solid waste incineration fly ash.In order to further explore the environment corrosion resistance of fly ash geopolymer, high temperature test of geopolymer is presented, referring to the relationship between high-temperature, constant temperature and compressive strength.Through the compressive strength test of geopolymer test cubes at different temperature and different constant temperature time, the coupling relationship among temperature, constant temperature time and compressive strength of geopolymer is analyzed, and the mathematical models of these is established.Additionally the leaching concentractions of heavy metals in the fly ash-geopolymers after heating are determined to examine the stability.Based on the results of test, the 3D curved surface of temperature,constant temperature time and compressive strength of geopolymer is fitted.

  16. Performance of High-pressure-ratio Axial-flow Compressor Using Highly Cambered NACA 65-series Blower Blades at High Mach Numbers

    Science.gov (United States)

    Voit, Charles H; Guentert, Donald C; Dugan, James F

    1950-01-01

    A complete stage of an axial-flow compressor was designed and built to investigate the possibility of obtaining a high pressure ratio with an acceptable efficiency through the use of the optimum combination of high blade loading and high relative inlet Mach number. Over-all stage performance was investigated over a range of flows at equivalent tip speeds of 418 to 836 feet per second. At design speed (836 ft/sec), a peak total-pressure ration of 1.445 was obtained with an adiabatic efficiency of 0.89. For design angle of attack at the mean radius, a total-pressure ratio of 1.392 was obtained.

  17. Investigation of normal force and moment coefficients for an AUV at nonlinear angle of attack and sideslip range

    Digital Repository Service at National Institute of Oceanography (India)

    Barros, E.A. de; Dantas, J.L.D.; Pascoal, A.M.; Desa, E.S.

    . In the “PNA model” (Principles of Naval Architecture [27]), the interference between the fin and the bare hull is considered through the ef- fectiveaspect ratio, which is different from the geometric aspect ratio... of Naval Architecture. Jersey City, NJ: SNAME, 1988, vol. III, pp. 291–308. [29] H. J. Allen and E. W. Perkins, “A study on the effects of viscosity on flow over slender inclined bodies of revolution,” NACA Rep. 1048, 1951. [30] M. M. Munk, “The aerodynamic...

  18. Investigation of Load Prediction on the Mexico Rotor Using the Technique of Determination of the Angle of Attack

    DEFF Research Database (Denmark)

    Yang, Hua; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2012-01-01

    on rotor blades developed by SHEN, et al is successfully used to extract airfoil data from experimental characteristics on the MEXICO (Model experiments in controlled conditions) rotor. Detailed surface pressure and particle image velocimetry (PIV) flow fields at different rotor azimuth positions...

  19. Managing the Fruit Fly Experiment.

    Science.gov (United States)

    Jeszenszky, Arleen W.

    1997-01-01

    Describes a sophisticated version of the fruit fly experiment for teaching concepts about genetics to biology students. Provides students with the opportunity to work with live animals over an extended period. (JRH)

  20. The Hungry Fly: Hydrodynamics of feeding in the common house fly

    CERN Document Server

    Prakash, Manu

    2010-01-01

    A large number of insect species feed primarily on a fluid diet. To do so, they must overcome the numerous challenges that arise in the design of high-efficiency, miniature pumps. Although the morphology of insect feeding structures has been described for decades, their dynamics remain largely unknown even in the most well studied species (e.g. fruit fly). Here, in the fluid dynamics video, we demonstrate in-vivo imaging and microsurgery to elucidate the design principles of feeding structures of the common house fly. Using high-resolution X-ray absorption microscopy, we record in-vivo flow of sucrose solutions through the body over many hours during fly feeding. Borrowing from microsurgery techniques common in neurophysiology, we are able to perturb the pump to a stall position and thus evaluate function under load conditions. Furthermore, fluid viscosity-dependent feedback is observed for optimal pump performance. As the gut of the fly starts to fill up, feedback from the stretch receptors in the cuticle di...

  1. Subtropical Fruit Fly Invasions into Temperate Fruit Fly Territory in California's San Joaquin Valley

    Science.gov (United States)

    Subtropical fruit fly species including peach fruit fly, Bactrocera zonata (Saunders); melon fly, B. cucurbitae (Coquillett); oriental fruit fly, B. dorsalis (Hendel); and Mediterranean fruit fly, Ceratitis capitata Weidemann, have been detected in the past decade in the San Joaquin Valley of Califo...

  2. Performances and Mechanism of Geopolymers Prepared from Thermally-treated Sludge and High-calcium Fly Ash%热活化污泥-高钙粉煤灰地聚合物的性能与机理

    Institute of Scientific and Technical Information of China (English)

    郭晓潞; 施惠生

    2012-01-01

    A study was made of the feasibility to prepare a complex geopolymer by water glass-activated high-calcium fly ash and thermally-treated sludge, and the performance and mechanism of the geopolymer were also explored. The results show that compressive strength of the geopolymer is better when 10% fly ash is replaced by thermally-activated sludge (<45 μm) at 900 ℃ for 1 hour. In complex geopolymeric matrix, amorphous geopolymeric gel coveres around spherical fly ahs granule, the Zeolite-like mineral formes, meanwhile, the asymmetric stretching Al-O/Si-O bonds and Si-O-Si/ Si-O-Al bending band appear. This work is beneficial for extending raw materials of geopolymer, and also for utilizing of multi industrial wastes, especial the wastes containing silicate-aluminum phase and calcium.%研究采用水玻璃激发的高钙粉煤灰和热活化污泥制备复合地聚合物的可行性,并讨论制备的复合地聚合物的性能与机理.结果表明:经900℃焙烧lh的污泥(<45 μm)以10%质量分数的掺量取代高钙粉煤灰后研制成的地聚合物具有较好的抗压强度;在复合地聚合物体系中,无定形地聚合物凝胶包裹在球状粉煤灰颗粒周围,有类沸石矿物生成,出现Al-O/Si-O对称伸缩峰及Si-O-Si/Si-O-Al弯曲振动峰.这一研究可以丰富地聚合物原材料的选择,有助于含硅铝相和含钙工业废弃物的资源化利用.

  3. Flying in Two Dimensions

    CERN Document Server

    Prakash, Manu

    2011-01-01

    Diversity and specialization of behavior in insects is unmatched. Insects hop, walk, run, jump, row, swim, glide and fly to propel themselves in a variety of environments. We have uncovered an unusual mode of propulsion of aerodynamic flight in two dimensions in Waterlilly Beetles \\emph{(Galerucella)}. The adult beetles, often found in water lilly ponds, propel themselves strictly in a two-dimensional plane on the surface of water via flapping wing flight. Here we analyze the aerodynamics of this peculiar flight mode with respect to forces exerted on the organism during flight. The complexity of 2-D flight is captured by accounting for additional forces beyond gravitational, thrust, lift and drag, exerted on the insect body in 3D flight. Understanding this constrained propulsion mode requires accounting for viscous drag, surface tension, buoyancy force, and capillary-wave drag. Moreover, dramatic differences exist in the magnitude of the resultant forces in 2D vs. 3D flight. Here, in this fluid dynamics video...

  4. Fly ash. Quality recycling material

    Energy Technology Data Exchange (ETDEWEB)

    Blomster, D.; Leisio, C.

    1996-11-01

    Imatran Voima`s coal-fired power plants not only generate power and heat but also produce fly ash which is suitable raw material for recycling. This material for recycling is produced in the flue gas cleaning process. It is economical and, thanks to close quality control, is suitable for use as a raw material in the building materials industry, in asphalt production, and in earthworks. Structures made from fly ash are also safe from an environmental point of view. (orig.)

  5. Fly ash. Quality recycling material

    Energy Technology Data Exchange (ETDEWEB)

    Blomster, D.; Leisio, C.

    1996-11-01

    Imatran Voima`s coal-fired power plants not only generate power and heat but also produce fly ash which is suitable raw material for recycling. This material for recycling is produced in the flue gas cleaning process. It is economical and, thanks to close quality control, is suitable for use as a raw material in the building materials industry, in asphalt production, and in earthworks. Structures made from fly ash are also safe from an environmental point of view. (orig.)

  6. Improved Sorting Scheme of Microstructure of Fly Ash

    Institute of Scientific and Technical Information of China (English)

    王立刚; 彭苏平

    2002-01-01

    Aiming at the problem of the existing sorting for microstructure of flyash, an improved scheme was put forward in this paper. First, fly ash particles are divided into four groups as low-calcium, iron, high calcium and char particle acco rding to the substance components of fly ash. Then fly ash particles are divided into 14 sub-groups, for example: cenospheres, plerospheres, solid spheres, porous char and dense char based on their chemical composition, shape and the chara cteristics of inner-structure of fly ash. It has a distinct difference in granu le configuration, inner-structure and substance components. Some disadvantages of the existing scheme such as unilateralism and imprecision have been overcome in the advanced schemes.

  7. Pitch Perfect: How Fruit Flies Control their Body Pitch Angle

    CERN Document Server

    Whitehead, Samuel C; Canale, Luca; Cohen, Itai

    2015-01-01

    Flapping insect flight is a complex and beautiful phenomenon that relies on fast, active control mechanisms to counter aerodynamic instability. To directly investigate how freely-flying D. melanogaster control their body pitch angle against such instability, we perturb them using impulsive mechanical torques and film their corrective maneuvers with high-speed video. Combining experimental observations and numerical simulation, we find that flies correct for pitch deflections of up to 40 degrees in 29 +/- 8 ms by bilaterally modulating their wings' front-most stroke angle in a manner well-described by a linear proportional-integral (PI) controller. Flies initiate this corrective process after only 10 +/- 2 ms, indicating that pitch stabilization involves a fast reflex response. Remarkably, flies can also correct for very large-amplitude pitch perturbations--greater than 150 degrees--providing a regime in which to probe the limits of the linear-response framework. Together with previous studies regarding yaw an...

  8. Acidification of calf bedding reduces fly development and bacterial abundance.

    Science.gov (United States)

    Calvo, M S; Gerry, A C; McGarvey, J A; Armitage, T L; Mitloehner, F M

    2010-03-01

    Environmental stressors, such as high fly density, can affect calf well-being. Sodium bisulfate (SBS) is an acidifier that reduces the pH of flooring and bedding, creating a medium that neither bacteria nor immature flies (also known as larvae or maggots) can thrive in. Two experiments were conducted to investigate the application of SBS to a mixture of rice hull calf bedding and calf slurry (BED) to reduce house fly (Musca domestica L.) larval density and the abundance of bacteria. In experiment 1, dish pans containing 1L of BED and 3,000 house fly eggs were treated with SBS at concentrations of 0, 8.9, 17.7, and 26.5g of SBS/0.05m(2) of BED (CON, LOW, MED, and HIGH, respectively), with each SBS concentration applied to 4 individual pans (16 pans total). Reapplication of the same SBS concentrations in each pan occurred 3 times/wk throughout the 23-d trial. Larval house fly survival was significantly reduced in all pans with SBS relative to CON pans, with lowest survival rates in the MED and HIGH pans (99% and 100% reduction, respectively). The mean pH for each treatment was inversely related to the SBS concentration. In experiment 2, pans containing 1L of BED and 3,000 house fly eggs were treated with either 0g of SBS (CON), 8.9g of SBS/0.05m(2) of BED with reapplication of the acidifier 3 times/wk (SB3x), or 8.9g of SBS/0.05m(2) of BED applied only once at 48h before the end of the 8 d-trial (SB48). Larval house fly survival and bacterial concentrations were reduced (90% larval reduction and 68% bacterial reduction) in the SB3x treatment relative to the CON. Mean pH was also reduced in SB3x pans relative to CON or SB48 pans. Overall, acidification of calf BED using the acidifier SBS resulted in a reduction of bacteria and house fly larval survival. This form of fly control might be expected to reduce adult fly production and, therefore, fly-related stress in calves.

  9. FUNDAMENTAL STUDY OF LOW-NOx COMBUSTION FLY ASH UTILIZATION

    Energy Technology Data Exchange (ETDEWEB)

    ERIC M. SUUBERG; ROBERT H. HURT

    1998-10-19

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over fifty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives.

  10. Water repellency of fly ash-enriched forest soils from eastern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, P.; Fleige, H.; Horn, R. [Forest Research Institute, Freiburg (Germany). Dept. of Soils & Environment

    2010-12-15

    Fly ash-enriched soils occur widely throughout the industrial regions of eastern Germany and in other heavily industrialized areas. A limited amount of research has suggested that fly ash enrichment alters the water repellency (WR) characteristics of soil. This study concentrates on the influence of fly ash enrichment on WR of forest soils with a focus on forest floor horizons (FFHs). The soils were a Technosol developed from pure lignite fly ash, FFHs with lignite fly ash, and FFHs without lignite fly ash enrichment. Three different methods were used to characterize soil WR. Additionally, carbon composition was determined using {sup 13}C-NMR spectra to interpret the influence of the organic matter. This study showed that the actual WR characteristics of undisturbed, fly ash-enriched soils can be explained in terms of the composition of soil organic matter, with the fly ash content playing only a minimal role. Regardless of the huge amounts of mainly mineral fly ash enrichment, all undisturbed FFHs were comparable in their WR characteristics and their carbon compositions, which were dominated by recently-formed organic substances. The pure fly ash deposit was strongly influenced by lignite remains, with the topsoil having a greater content of recent plant residues. Thus, the undisturbed topsoil was more repellent than the subsoil. When homogenized samples were used, we found a distinct effect of fly ash enrichment and structure on WR. Water repellency of the pure fly ash horizons did not differ distinctly, while the fly ash enrichment in the FFHs caused a significant reduction in WR. These results led to the assumption that water-repellent structures of the topsoils were probably the result of hydrophobic coatings of recently formed organic substances, whereby the initially high wettability of the mainly mineral, hydrophilic fly ash particles was reduced.

  11. Production of inorganic pellet binders from fly-ash. Technical report, March 1--May 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Kawatra, S.K.; Eisele, T.C.

    1995-12-31

    Fly-ash is produced by all coal-fired utilities, and it must be removed from the plant exhaust gases, collected, and disposed of. While much work has been done in the past to utilize fly-ash rather than disposing of it, we nevertheless do not find widespread examples of successful industrial utilization. This is because past work has tended to find uses only for high-quality, easily-utilized fly-ashes, which account for less than 25% of the fly-ash that is produced. The main factor which makes fly-ashes unusable is a high unburned carbon content. In this project, physical separation technologies are being used to remove this carbon, and to convert these unusable fly-ashes into usable products. The main application being studied for the processed fly-ash is as a binder for inorganic materials, such as iron-ore pellets. In the second quarter, additional fly-ash samples were collected from the E. D. Edwards station (Bartonville, IL). Experimentation was begun to study the removal of carbon from these fly-ashes by froth flotation, and make and test pellets that use fly-ash as binder. During the current quarter, flotation experiments were continued on the fly- ashes. Three types of ashes were studied: 1. Ash from the disposal pond (``wet`` ash); 2. Dry fly-ash collected directly from the standard burners (``low-carbon`` ash); 3. Dry fly-ash collected from the low-NOx burners (``high-carbon`` ash). Each of these was chemically analyzed, and conventional flotation experiments were carried out to determine the optimum reagent dosages for carbon removal. Decarbonized ashes were then made from each ash type, in sufficient quantity to be used in pelletization experiments.

  12. Relativistic Tennis Using Flying Mirror

    Science.gov (United States)

    Pirozhkov, A. S.; Kando, M.; Esirkepov, T. Zh.; Ma, J.; Fukuda, Y.; Chen, L.-M.; Daito, I.; Ogura, K.; Homma, T.; Hayashi, Y.; Kotaki, H.; Sagisaka, A.; Mori, M.; Koga, J. K.; Kawachi, T.; Daido, H.; Bulanov, S. V.; Kimura, T.; Kato, Y.; Tajima, T.

    2008-06-01

    Upon reflection from a relativistic mirror, the electromagnetic pulse frequency is upshifted and the duration is shortened by the factor proportional to the relativistic gamma-factor squared due to the double Doppler effect. We present the results of the proof-of-principle experiment for frequency upshifting of the laser pulse reflected from the relativistic "flying mirror", which is a wake wave near the breaking threshold created by a strong driver pulse propagating in underdense plasma. Experimentally, the wake wave is created by a 2 TW, 76 fs Ti:S laser pulse from the JLITE-X laser system in helium plasma with the electron density of ≈4-6×1019 cm-3. The reflected signal is observed with a grazing-incidence spectrograph in 24 shots. The wavelength of the reflected radiation ranges from 7 to 14 nm, the corresponding frequency upshifting factors are ˜55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3×107 photons/sr. This effect can be used to generate coherent high-frequency ultrashort pulses that inherit temporal shape and polarization from the original (low-frequency) ones. Apart from this, the reflected radiation contains important information about the wake wave itself, e.g. location, size, phase velocity, etc.

  13. Examining the nature of fear of flying.

    Science.gov (United States)

    Hawkins-Gilligan, Janice; Dygdon, Judith A; Conger, Anthony J

    2011-10-01

    The nature of fear of flying (FOF) is not well understood. It is commonly assumed to be a fear learned from flight-specific experiences. However, existing literature suggests that FOF is a manifestation of fears of other stimuli (e.g., heights) embedded in the flying situation, but not specific to it. This study compared the level of prediction of FOF attained from flight-specific conditioning experiences (specifically, classical conditioning experiences in direct, observational, and verbal modes) with the level of prediction attained from flight-embedded fears. There were 109 university students who completed the Flight Anxiety Situations Questionnaire (FAS) and the Fear Survey Schedule, Version III (FSS) as well as demographic and flying experience questionnaires built for this study. All FOF measures were highly predicted by at least one flight-embedded fear. Conversely, conditioning experiences predicted only four of five FOF measures and this prediction was not strong. In general, conditioning experiences did not behave as in previous studies of conditioning and fear. The results suggest that FOF is based more on several flight-embedded innate fears than on learned fears. The implications of these results for FOF emergence and prevention are discussed.

  14. KINETICS OF FLY ASH BENEFICIATION BY CARBON BURNOUT

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Joseph N.D. Dodoo; Dr. Joseph M. Okoh

    2000-11-01

    Surface area analyses performed on fly ash samples reveal that the surface area is controlled by carbon content. The higher surface areas found in large particles are due to the presence of highly porous carbonaceous particles. Adsorption-desorption isotherms and t-plots of fly ash samples indicate that fly ash is porous. BJH Adsorption/Desorption pore size analysis reveal that pore diameters are independent of sieve size. They appear to be dependent only on the nature of the material which confers porosity. Based on the results of Brown and Dykstra (41) it is reasonable to assume that calculations of reaction rates at temperatures above 550 C were confounded by weight losses from processes other than carbon oxidation and, therefore, are not useful in determination of the temperature dependence of carbon oxidation in fly ash. The results of the present study indicate that temperatures below 550 C should be used for future studies in order to satisfactorily assess the temperature dependence of carbon oxidation in fly ash. Furthermore, it is also advisable that percent carbon determinations be performed on fly ash samples after the oxidation reactions to determine whether all carbon present in fly ash is oxidized. This will ensure that reaction rates are representative of the complete oxidation of carbon. An inverse relationship was determined between reaction rates and oxygen concentration for this study. As discussed, this may be due to volatilization of volatiles from fly ash and ease of transport of products away from the reaction sites by the action of the vacuum applied to the samples. A more accurate determination of oxygen dependence of carbon oxidation can be accomplished by the use of specialty gases containing different concentrations of oxygen which could eliminate the need to apply vacuum to the samples.

  15. Design and construction of a remote piloted flying wing. B.S. Thesis

    Science.gov (United States)

    Costa, Alfred J.; Koopman, Fritz; Soboleski, Craig; Trieu, Thai-Ba; Duquette, Jaime; Krause, Scott; Susko, David; Trieu, Thuyba

    1994-01-01

    Currently, there is a need for a high-speed, high-lift civilian transport. Although unconventional, a flying wing could fly at speeds in excess of Mach 2 and still retain the capacity of a 747. The design of the flying wing is inherently unstable since it lacks a fuselage and a horizontal tail. The project goal was to design, construct, fly, and test a remote-piloted scale model flying wing. The project was completed as part of the NASA/USRA Advanced Aeronautics Design Program. These unique restrictions required us to implement several fundamental design changes from last year's Elang configuration including wing sweepback and wingtip endplates. Unique features such as a single ducted fan engine, composite structural materials, and an electrostatic stability system were incorporated. The result is the Banshee '94. Our efforts will aid future projects in design and construction techniques so that a viable flying wing can become an integral part of the aviation industry.

  16. Analytical and computational investigations of airfoils undergoing high-frequency sinusoidal pitch and plunge motions at low Reynolds numbers

    Science.gov (United States)

    McGowan, Gregory Z.

    Current interests in Micro Air Vehicle (MAV) technologies call for the development of aerodynamic-design tools that will aid in the design of more efficient platforms that will also have adequate stability and control for flight in gusty environments. Influenced largely by nature MAVs tend to be very small, have low flight speeds, and utilize flapping motions for propulsion. For these reasons the focus is, specifically, on high-frequency motions at low Reynolds numbers. Toward the goal of developing design tools, it is of interest to explore the use of elementary flow solutions for simple motions such as pitch and plunge oscillations to predict aerodynamic performance for more complex motions. In the early part of this research, a validation effort was undertaken. Computations from the current effort were compared with experiments conducted in a parallel, collaborative effort at the Air Force Research Laboratory (AFRL). A set of pure-pitch and pure-plunge sinusoidal oscillations of the SD7003 airfoil were examined. Phase-averaged measurements using particle image velocimetry in a water tunnel were compared with computations using two flow solvers: (i) an incompressible Navier-Stokes Immersed Boundary Method and (ii) an unsteady compressible Reynolds-Averaged Navier-Stokes (RANS) solver. The motions were at a reduced frequency of k = 3.93, and pitch-angle amplitudes were chosen such that a kinematic equivalence in amplitudes of effective angle of attack (from plunge) was obtained. Plunge cases showed good qualitative agreement between computation and experiment, but in the pitch cases, the wake vorticity in the experiment was substantially different from that predicted by both computations. Further, equivalence between the pure-pitch and pure-plunge motions was not attained through matching effective angle of attack. With the failure of pitch/plunge equivalence using equivalent amplitudes of effective angle of attack, the effort shifted to include pitch-rate and

  17. Damping properties of fly ash/epoxy composites

    Institute of Scientific and Technical Information of China (English)

    Jian Gu; Gaohui Wu; Xiao Zhao

    2008-01-01

    An inexpensive fly ash (FA), which is from a waste product, was employed to prepare fly ash/epoxy composites. The purpose of this study is to characterize the contributions of matrix viscoelasticity, hollow structure characteristic (porosity), and filler/matrix interface friction to the high vibration damping capacity of such composites. The damping properties of the composites were investigated in the temperature range of-40 to 150℃C and in the frequency range of 10 to 800 Hz by using a tension-compression mode. The results indicate that the peak value of damping loss factor (tanδ) for the fly ash/epoxy composites can reach 0.70-0.90 in test specification, and the attenuation of damping loss factor is inconspicuous with increasing frequency. In addition, scanning electron microscope (SEM) was used to observe the morphology of the fly ash as well as its distribution in the matrix, which will help to analyze the effect of fly ash on the damping properties of the fly ash/epoxy composites.

  18. [Study on mercury re-emissions during fly ash utilization].

    Science.gov (United States)

    Meng, Yang; Wang, Shu-Xiao

    2012-09-01

    The amount of fly ash produced during coal combustion is around 400 million tons per year in China. About 65%-68% of fly ash is used in building material production, road construction, architecture and agriculture. Some of these utilization processes include high temperature procedures, which may lead to mercury re-emissions. In this study, experiments were designed to simulate the key process in cement production and steam-cured brick production. A temperature programmed desorption (TPD) method was used to study the mercury transformation in the major utilization processes. Mercury re-emission during the fly ash utilization in China was estimated based on the experimental results. It was found that mercury existed as HgCl2 (Hg2 Cl2), HgS and HgO in the fly ash. During the cement production process, more than 98% of the mercury in fly ash was re-emitted. In the steam-curing brick manufacturing process, the average mercury re-emission percentage was about 28%, which was dominated by the percentage of HgCl2 (Hg2 Cl2). It is estimated that the mercury re-emission during the fly ash utilization have increased from 4.07 t in 2002 to 9.18 t in 2008, of which cement industry contributes about 96.6%.

  19. Insulating brick from fly ash of thermal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S.N.; Majumdar, A.; Majumdar, S.K.

    1986-04-01

    Disposal of fly ash, a major byproduct of thermal power stations burning high ash pulverized fuel, has posed a serious problem of storage space required on one hand and the cost involved on the other. Fly ash possesses pozzolanic property. R and D work on utilization of fly ash in the form of sand-lime brick or cellular concrete has been already done. Other avenues of utilization are cement and concrete industry. All these are based on pozzolanic property of fly ash which decreases with the increase of unburnt carbon content in the same. The overall present consumption of fly ash is barely 5-7 per cent of the total production. A process has been developed to utilize fly ash with comparatively higher amount of carbonaceous matter in particular, to make insulating/semi-insulating bricks of standard size through use of other normal ingredients like clay (a plastic material), sulphite lye, molasses, etc. as binder along with some propertion of saw dust. The bricks made so far have been tested for their normal properties and these conform to a product of semi-insulating type. 21 refs., 2 tabs.

  20. 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.

  1. Oviposition Deterrence and Immature Survival of Filth Flies (Diptera: Muscidae) When Exposed to Commercial Fungal Products

    Science.gov (United States)

    Machtinger, E.T.; Weeks, E.N.I.; Geden, C. J.

    2016-01-01

    Filth flies are pests of livestock, and can transmit pathogens that cause disease to animals and their caretakers. Studies have shown successful infection of adult filth flies following exposure to different strains and formulations of entomopathogenic fungi. This study aimed to examine the effects of commercial formulations of Beauveria bassiana (Balsamo) (Moniliales: Moniliaceae) (i.e., BotaniGard ES, Mycotrol O, balEnce), and Metarhizium brunneum (Metsch.) (Ascomycota: Hypocreales) (i.e., Met52 EC), on filth fly oviposition and immature fly survival after exposure. House flies, Musca domestica L., laid significantly fewer eggs on Met52 EC-treated surfaces than on surfaces treated with all other products and the control. Similar numbers of eggs were laid on surfaces treated with all B. bassiana products, but egg production was half of the control. Stable flies, Stomoxys calcitrans (L.), laid the fewest eggs on Met52 EC- and Mycotrol O-treated surfaces. This species did not distinguish between the remaining products and the control. In a second experiment, house fly eggs were placed on treated cloths so that hatched larvae contacted the treatment prior to development. Met52 EC had the greatest effect on immature survival with a significant reduction in recovered pupae at the medium and high doses of fungi. Overall, Met52 EC, containing M. brunneum, had the greatest effect on house fly and stable fly oviposition deterrence and immature development of house flies. Management implications are discussed. PMID:27302955

  2. Effect of the Additives on the Desulphurization Rate of Flash Hydrated and Agglomerated CFB Fly Ash

    Science.gov (United States)

    Li, D. X.; Li, H. L.; Xu, M.; Lu, J. F.; Liu, Q.; Zhang, J. S.; Yue, G. X.

    CFB fly ash from separators was mixed with water or the mixture of water and additives under the temperature of 363K by use of a blender. Then, this compound of fly ash and water or additives was pumped into a CFB combustion chamber by a sludge pump. Because the temperature of flue gas was high in CFB, the fly ash was hydrated fast and agglomerated in the same time. Through this process, the size of agglomerating fly ash is larger than the original particle and the relative residence time of agglomerated fly ash in CFB becomes longer. Therefore, the rate of utility of calcium in fly ash improves and the content of carbon in fly ash decreases. This results in a low Ca/S and low operational cost for CFB boiler. The additive is one key factor, which affects the rate of desulfurization of agglomerated fly ash. Effect of different additives on rate of desulfurization is not same. Cement and limestone are beneficiated to sulfur removal of agglomerated fly ash, but sodium silicate does not devote to the rate of sulfur removal of agglomerated fly ash.

  3. Fly-in/Fly-out: Implications for Community Sustainability

    Directory of Open Access Journals (Sweden)

    Keith Storey

    2010-04-01

    Full Text Available “Fly-in/fly-out” is a form of work organization that has become the standard model for new mining, petroleum and other types of resource development in remote areas. In many places this “no town” model has replaced that of the “new town.” The work system has both beneficial and adverse implications for the sustainability of both existing communities near new resource developments and for the more distant communities from which workers are drawn. This paper explores these outcomes drawing upon examples from North America and Australia.

  4. 锂渣复合粉煤灰高性能混凝土早期抗压强度影响因素的比较分析%The Comparative Analysis of Influence on the Early Compressive strength of lithium Slag Compound Fly Ash High Performance Concrete

    Institute of Scientific and Technical Information of China (English)

    周海雷; 杨恒阳; 努尔开力·依孜特罗甫; 侍克斌

    2012-01-01

    Lithium slag compound fly ash high performance concrete was made by the orthogonal experiment design method, the preparation of the use of poor analysis and variance analysis method to analyze the impact that the water-binder ratio, lithium slag mix content and the fly ash for lithium slag compound fly ash of high performance concrete compressive strength of the early. Lithium slag on lithium slag compound fly ash high performance concrete compressive strength has significance effects Dmng early. Dmng analysis of the poor, poor relative difference degree was introduced the concept.%运用正交试验设计的方法配制锂渣复合粉煤灰高性能混凝土,运用极差分析和方差分析的方法分析了水胶比、锂渣掺量和粉煤灰掺量对锂渣复合粉煤灰高性能混凝土的早期抗压强度的影响,得出锂渣较粉煤灰对锂渣复合粉煤灰高性能混凝土早期抗压强度影响显著.在进行极差分析时,引入了极差相对差异度这一概念.

  5. Are flying-foxes coming to town? Urbanisation of the spectacled flying-fox (Pteropus conspicillatus in Australia.

    Directory of Open Access Journals (Sweden)

    Jessica Tait

    Full Text Available Urbanisation of wildlife populations is a process with significant conservation and management implications. While urban areas can provide habitat for wildlife, some urbanised species eventually come into conflict with humans. Understanding the process and drivers of wildlife urbanisation is fundamental to developing effective management responses to this phenomenon. In Australia, flying-foxes (Pteropodidae are a common feature of urban environments, sometimes roosting in groups of tens of thousands of individuals. Flying-foxes appear to be becoming increasingly urbanised and are coming into increased contact and conflict with humans. Flying-fox management is now a highly contentious issue. In this study we used monitoring data collected over a 15 year period (1998-2012 to examine the spatial and temporal patterns of association of spectacled flying-fox (Pteropus conspicillatus roost sites (camps with urban areas. We asked whether spectacled flying-foxes are becoming more urbanised and test the hypothesis that such changes are associated with anthropogenic changes to landscape structure. Our results indicate that spectacled flying-foxes were more likely to roost near humans than might be expected by chance, that over the period of the study the proportion of the flying-foxes in urban-associated camps increased, as did the number of urban camps. Increased urbanisation of spectacled flying-foxes was not related to changes in landscape structure or to the encroachment of urban areas on camps. Overall, camps tended to be found in areas that were more fragmented, closer to human habitation and with more urban land cover than the surrounding landscape. This suggests that urbanisation is a behavioural response rather than driven by habitat loss.

  6. Escherichia coli fliAZY operon.

    OpenAIRE

    Mytelka, D S; Chamberlin, M J

    1996-01-01

    We have cloned the Escherichia coli fliAZY operon, which contains the fliA gene (the alternative sigma factor sigma F) and two novel genes, fliZ and fliY. Transcriptional mapping of this operon shows two start sites, one of which is preceded by a canonical E sigma F-dependent consensus and is dependent on sigma F for expression in vivo and in vitro. We have overexpressed and purified sigma F and demonstrated that it can direct core polymerase to E sigma F-dependent promoters. FliZ and FliY ar...

  7. Bombykol receptors in the silkworm moth and the fruit fly.

    Science.gov (United States)

    Syed, Zainulabeuddin; Kopp, Artyom; Kimbrell, Deborah A; Leal, Walter S

    2010-05-18

    Male moths are endowed with odorant receptors (ORs) to detect species-specific sex pheromones with remarkable sensitivity and selectivity. We serendipitously discovered that an endogenous OR in the fruit fly, Drosophila melanogaster, is highly sensitive to the sex pheromone of the silkworm moth, bombykol. Intriguingly, the fruit fly detectors are more sensitive than the receptors of the silkworm moth, although its ecological significance is unknown. By expression in the "empty neuron" system, we identified the fruit fly bombykol-sensitive OR as DmelOR7a (= DmOR7a). The profiles of this receptor in response to bombykol in the native sensilla (ab4) or expressed in the empty neuron system (ab3 sensilla) are indistinguishable. Both WT and transgenic flies responded with high sensitivity, in a dose-dependent manner, and with rapid signal termination. In contrast, the same empty neuron expressing the moth bombykol receptor, BmorOR1, demonstrated low sensitivity and slow signal inactivation. When expressed in the trichoid sensilla T1 of the fruit fly, the neuron housing BmorOR1 responded with sensitivity comparable to that of the native trichoid sensilla in the silkworm moth. By challenging the native bombykol receptor in the fruit fly with high doses of another odorant to which the receptor responds with the highest sensitivity, we demonstrate that slow signal termination is induced by overdose of a stimulus. As opposed to the empty neuron system in the basiconic sensilla, the structural, biochemical, and/or biophysical features of the sensilla make the T1 trichoid system of the fly a better surrogate for the moth receptor.

  8. 粉煤灰-混凝-SBR法处理高浓度洗涤剂废水%Treatment of high-strength synthetic detergent wastewater by fly ash-coagulation and SBR process

    Institute of Scientific and Technical Information of China (English)

    李荣喜; 杨春平; 许第发; 宋勇

    2011-01-01

    Aiming at highly concentrated low biodegradability and highly load characteristics on the synthetic detergent wastewater, a method for treating it has been studied using fly ash adsorption and coagulation with pretreatment and then SBR processes treatment. The results showed that at normal temperature, the dosages of fly ash and PAC were the main influencing factors, and the pretreatment removal rates of COD and LAS could reach to 76.4% and 77.1% , respectively, when COD were 6 000 ~ 7 000 mg/L and LAS concentrations were 600 ~ 650 mg/L in the wastewater. The final effluent concentrations of COD and LAS were less than 500 mg/L and 17 mg/L after sequencing batch reactor (SBR) treatment, corresponding to the total removal rate could be up to over 92.4% and 97.3% , respectively. The effluent could meet the third degree of synthetic detergent wastewater required, and the process could be suitable for high-strength synthetic detergent wastewater.%针对车间合成洗涤剂生产废水浓度高、可生化性差、负荷大等特点,采用粉煤灰吸附-混凝进行物化处理和SBR法生物处理洗涤剂废水.运行结果表明:在常温下,当处理车间废水初始COD为6000~7000 mg/L、LAS为600~650 mg/L时,物化处理COD和LAS去除率分别为76.4%和77.1%,其中粉煤灰、PAC的投加量对去除效果影响较大.然后通过SBR处理后,COD≤500m/L和LAS≤17mg/L,总的去除效率分别达到92.4%和92.4%.出水水质达表面活性剂三级排放标准,可应用于高浓度洗涤剂废水处理.

  9. High-Energy Atmospheric Reentry Test Aerothermodynamic Analysis

    Science.gov (United States)

    Mazaheri, Alireza

    2013-01-01

    This paper presents an assessment of the aerothermodynamic environment around an 8.3 meter High Energy Atmospheric Reentry Test (HEART) vehicle. This study generated twelve nose shape configurations and compared their responses at the peak heating trajectory point against the baseline nose shape. The heat flux sensitivity to the angle of attack variations are also discussed. The possibility of a two-piece Thermal Protection System (TPS) design at the nose is also considered, as are the surface catalytic affects of the aeroheating environment of such configuration. Based on these analyses, an optimum nose shape is proposed to minimize the surface heating. A recommendation is also made for a two-piece TPS design, for which the surface catalytic uncertainty associated with the jump in heating at the nose-IAD juncture is reduced by a minimum of 93%. In this paper, the aeroshell is assumed to be rigid and the inflatable fluid interaction effect is left for future investigations

  10. Dermatobia, the neotropical warble fly.

    Science.gov (United States)

    Sancho, E

    1988-09-01

    The neotropical warble fly, Dermatobia hominis (Fig. 1), has plagued neotropical America since preColombian times, and has become an economically important pest causing substantial losses to the meat, milk and leather industries from northern Mexico down to northern Argentina. Its life cycle (Box 1) is astonishingly complex, requiring another insect as a phoretic carrier of its eggs to the skin of its mammal hosts. Here Eugenio Sancho discusses factors that contribute to the current economic and public health importance of this myiasis-causing fly.

  11. Slag-fly ash based cementitious materials special for high performance concrete%矿渣-粉煤灰基高性能混凝土专用胶凝材料

    Institute of Scientific and Technical Information of China (English)

    伏程红; 倪文; 张旭芳; 王中杰; 田明阳

    2011-01-01

    通过优化配比组分、粒级设计和使用外加剂,制备出一种高掺量矿渣、粉煤灰且使用水泥熟料较少的矿渣-粉煤灰基高性能混凝土专用胶凝材料.研究了物料粉磨方式、石膏掺量、矿渣与粉煤灰的掺量及比例对复合高性能胶凝材料体系强度的影响,并通过X射线衍射(XRD)和扫描电镜(SEM)微观分析手段观察其微观结构和水化产物,阐明了复合胶凝材料活性与级配协同优化效应.复合胶凝材料胶砂水胶比为0.36时具有较好的流动度,胶砂试块养护28 d抗压强度可以达到58.9MPa,抗折强度达到14.2 MPa,并具有良好的抗硫酸盐侵蚀性能,配制的混凝土具有良好的抗碳化性能.%Cementitious materials special for high performance concrete with high volume of fly ash and slag and less cement clinker were prepared by optimizing the proportion of ingredients and the size fraction and using an additive. The effects of grinding modes, gypsum amount and the mix proportion of slag to fly ash on the strength of the cementitious materials were studied. X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) were used to observe the microstructure and hydration products and investigate the collaborative optimization effect between the activity and grading of the cementitious materials. The results show that cementitious materials have good mortar fluidity when the water-binder ratio (W/C) is 0. 36, the compressive strength of colloidal mortar specimens cured for 28 d is 58.9 MPa and the 28 d fiexural strength is 14.2 MPa, which have favorable properties of erosion resistance to sulfates. The concrete made from the cementitious materials has a better ability of carbonation resistance.

  12. Effects of Water Reducer on the Properties of High-volume Fly Ash Cement Mortar%减水剂对高掺量粉煤灰砂浆性能的影响

    Institute of Scientific and Technical Information of China (English)

    郑大锋; 邱学青; 欧阳新平; 杨东杰; 楼宏铭

    2006-01-01

    Effects of FDN and Calcium lignosulfonate (LS) on the properties of high-volume fly ash cement mortar were studied. It was found that compared with FDN, the water-reducing ratio of LS was lower and the ability of retaining the fluidity of the cement mortar was better; for the stability of the cement mortar, the effect of LS was almost the same as that of FDN at the dosage of 0.4 %. The adsorption on the cementitious surface, the effect on the zeta potential of cement particle surface and the foaming capacity of FDN and LS were measured. The results showed that, for the reasons of stronger air-entraining capacity of LS and the incomplete adsorption of FDN on the surface of cementitious particles, the water-reducing ratio of LS was close to FDN when the dosage was lower than 0.4 %. The better fluidity retention capacity of LS was attributed to the more stable zeta potential of the cement surface and the retarding effect of mortar setting. The experimental results suggested that for the purpose of utilizing LS better in the high-volume fly ash cement mortar in the grouting, some modification should be conducted to increase its water-reducing ratio.%研究了萘系高效减水剂(FDN)和木质素磺酸钙(LS)对高掺量粉煤灰砂浆性能的影响,测定了减水剂在胶凝颗粒表面的吸附、对水泥颗粒表面zeta电位等方面的影响.结果表明,和FDN相比,LS对砂浆的减水率较低,而对砂浆流动度保持能力较优;当掺量为0.4 wt%时,两者对砂浆稳定性的影响几乎一样.当掺量低于0.4 %时,LS的减水率和FDN接近是因为其具有较强的引气作用和FDN在胶凝颗粒表面吸附不完全;LS保持砂浆流动性能力较好是由于它的缓凝作用以及吸附LS的水泥颗粒表面zeta电位较稳定导致的.为了更好地将LS应用在高掺量粉煤灰砂浆中,可以从提高其减水率方面对其进行改性.

  13. Producing a synthetic zeolite from secondary coal fly ash.

    Science.gov (United States)

    Zhou, Chunyu; Yan, Chunjie; Zhou, Qi; Wang, Hongquan; Luo, Wenjun

    2016-11-01

    Secondary coal fly ash is known as a by-product produced by the extracting alumina industry from high-alumina fly ash, which is always considered to be solid waste. Zeolitization of secondary coal fly ash offers an opportunity to create value-added products from this industrial solid waste. The influence of synthesis parameters on zeolite NaA such as alkalinity, the molar ratio of SiO2/Al2O3, crystallization time and temperature was investigated in this paper. It was found that the types of synthetic zeolites produced were to be highly dependent on the conditions of the crystallization process. Calcium ion exchange capacity and whiteness measurements revealed that the synthesized product meets the standard for being used as detergent, indicating a promising use as a builder in detergent, ion-exchangers or selective adsorbents. Yield of up to a maximum of 1.54 g/g of ash was produced for zeolite NaA from the secondary coal fly ash residue. This result presents a potential use of the secondary coal fly ash to obtain a high value-added product by a cheap and alternative zeolitization procedure.

  14. Are flying wildlife attracted to (or do they avoid) wind turbines?

    Energy Technology Data Exchange (ETDEWEB)

    Larkin, Ronald [Univ. of Illinois, Urbana, IL (United States). Board of Trustees

    2010-03-31

    A DOE-sponsored research project found strong evidence that flying wildlife avoid or are attracted to commercial-scale wind turbines from a distance. Some nocturnally migrating birds avoid flying near turbines and few or none change flight paths to approach them. High-flying bats less often avoid flying near turbines and some are attracted to them from a distance, although bats’ flight paths were often complex and convoluted. The findings are being prepared for submission to a peer-reviewed scientific journal (Larkin, in prep 2013).

  15. Fruit Flies Help Human Sleep Research

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Fruit Flies Help Human Sleep Research Past Issues / Summer 2007 ... courtesy of NIGMS Neuroscientist Chiara Cirelli uses experimental fruit flies to study sleep. Although it may be tough ...

  16. Abnormal expression of FLI1 protein is an adverse prognostic factor in acute myeloid leukemia

    Science.gov (United States)

    Qiu, Yi Hua; Zhang, Nianxiang; Singh, Neera; Faderl, Stefan; Ferrajoli, Alessandra; York, Heather; Qutub, Amina A.; Coombes, Kevin R.; Watson, Dennis K.

    2011-01-01

    Friend leukemia virus integration 1 (FLI1), an Ets transcription factor family member, is linked to acute myelogenous leukemia (AML) by chromosomal events at the FLI1 locus, but the biologic impact of FLI1 expression on AML is unknown. FLI1 protein expression was measured in 511 newly diagnosed AML patients. Expression was similar in peripheral blood (PB) and BM and higher at diagnosis than at relapse (P = .02). Compared with normal CD34+ cells, expression in AML was above or below normal in 32% and 5% of patients, respectively. Levels were negatively correlated with an antecedent hematologic disorder (P = .002) but not with age or cytogenetics. Mutated NPM1 (P = .0007) or FLT3-ITD (P 0.3) with 19 others. The FLI1 level was not predictive of remission attainment, but patients with low or high FLI1 expression had shorter remission duration (22.6 and 40.3 vs 51.1 weeks, respectively; P = .01) and overall survival (45.2 and 35.4 vs 59.4 weeks, respectively; P = .03). High FLI1 levels were adverse in univariate and multivariate analysis. FLI1 expression is frequently abnormal and prognostically adverse in AML. FLI1 and/or its response genes may be therapeutically targetable to interfere with AML cell biology. PMID:21917756

  17. Preparation of Zeolite From High Calcium and Solid Sulfate Fly Ash and Its Adsorption of Cu2+%高钙固硫粉煤灰制备分子筛及对Cu2+的吸附

    Institute of Scientific and Technical Information of China (English)

    陈龙; 曹旺均; 宋明光; 王群英

    2016-01-01

    An unnamed zeolite product was successfully prepared by an alkali-fusion & hydrothermal-crystallization method from high calcium and solid sulfate fly ash. The effect of NaOH/fly ash mass ratio on the product was studied,and the products were analyzed by means of XRD, SEM and SEM-EDX. The results show that NaOH/fly ash mass ratio of 1.5 is more appropriate. Adsorption process of Cu2+ from aqueous solution by the prepared product CAZ-1.5 attributes to Lagergren second-order kinetics model under the condition of room temperature, initial Cu2+ mass concentration 200 mg·L-1 and the ratio of zeolite to solution 0.005g·ml-1. The corresponding adsorption constant is 62.50g/ (mg·min). The equilibrium isotherm for Cu2+ uptake corresponds closely to the Langmuir model under the condition of room temperature and the ratio of zeolite to solution 0.005g·ml-1. The maximum adsorption capacity of CAZ-1.5 is up to 107.5mg·g-1.%以高钙固硫粉煤灰为原料,采用碱熔-水热晶化法制备了一种未命名分子筛产品,考察了不同碱灰比对合成产物的影响,并采用了XRD、SEM、SEM-EDX等手段对产物进行了表征分析,实验结果表明1.5为较为合适的碱灰比。在室温条件下、Cu2+离子浓度为200mg·L-1、分子筛样品用量比为0.005g·ml-1时,制备得到的分子筛产品CAZ-1.5对溶液中Cu2+离子的吸附过程符合Lagergren二级速率方程,相应的二级吸附速率常数为62.50g/(mg·min)。在室温条件下、分子筛样品用量比为0.005g·ml-1时,制备得到的分子筛产品对不同浓度Cu2+的等温吸附曲线均符合Langmuir方程,理论饱和吸附容量(Qm)可达107.5 mg·g-1。

  18. Investigation on the interference correction of flying wing aircraft rear sting support in high speed wind tunnel test%飞翼布局高速风洞尾支干扰试验修正技术研究

    Institute of Scientific and Technical Information of China (English)

    衣秉立; 曾凯; 王世红

    2016-01-01

    For the test of a flat-after-body flying wing aircraft model in high speed wind tun-nel,the after-body has to be modified to satisfied the attachment of the balance.The deformation and the means of tail support may have some effect on the aerodynamic characteristics of the air-craft,and further affect the cruising efficiency,the trimming angle and the location of the aero-dynamic center.On the other hand,there are no commonly used horizontal tail and vertical tail for a flying wing aircraft in order to reduce RCS,the interference of distorted after-body can not to be neglected compares to weak lateral controllability.With the help of CFD and test tech-nique,the distorted after-body support interference has been obtained,in which rear sting is the main support and ventral strut an auxiliary one.The research indicates that the result of the wind tunnel test is accurate and reliable,the correction method can be adopted for the similar configu-ration model test.The methods of both numerical simulation and wind tunnel tests have been used to correct tail support interference of a flying wing model successfully.%飞翼布局飞行器模型往往具有尾部扁平的结构特点,进行高速风洞尾支测力时,尾部需要局部放大,由此带来尾部畸变和尾支杆的气动干扰,直接影响对巡航效率、焦点位置以及配平迎角的预测;另外,飞翼布局飞机为改善隐身特性,取消了平尾和垂尾,侧力和偏航力矩量级比较小,模型尾部的局部变形必然会对飞机横、航向试验数据带来不利影响。本文针对某飞翼布局模型,采用风洞试验和 CFD 数值模拟相结合的手段,通过腹支撑作为辅助支撑的“两步法”获得了尾部畸变及尾支杆的纵、横向支撑干扰影响。研究结果表明:该飞翼布局模型尾部畸变支撑纵、横向支撑干扰修正结果合理、可靠,精准度较高;所建立的试验与 CFD 相结合的研究方法可以用于

  19. Research on Resource Utilization of Dyeing Sludge with High Calcium Fly Ash%利用高钙粉煤灰对印染污泥进行资源化利用的研究

    Institute of Scientific and Technical Information of China (English)

    周何铤; 钟振宇; 黄曼; 何江伟

    2016-01-01

    This paper aims to prepare a new geopolymer material using high calcium fly ash and dyeing sludge as raw materials, and water glass and sodium hydroxide as activator. By means of standard Vicat apparatus, universal testing machine, FTIR, SEM, EDS and ICP-MS, analysis of the effect of dyeing sludge on properties of the geopolymer material was taken out. The results indicated that the setting time of the fly ash geopolymer shortened with the increase of the admixture of dyeing sludge. When its mass ratio was higher than 20%, the setting time is too short and not conducive to sample preparation. The compressive strength increased when dyeing sludge content was about 10wt%, while dropped remarkably when greater than 20wt%. Heavy metal leaching test of samples with 20wt% of dyeing sludge showed that the geopolymer had good sealing performance of heavy metals and the leaching concentration of heavy metals was far below limits.%以高钙粉煤灰为主合成材料,掺入印染污泥,并以水玻璃和氢氧化钠为激发剂,制备地质聚合物材料,并借助标准维卡仪、万能试验机、FTIR、SEM、EDS和ICP-MS等手段,分析印染污泥对该地质聚合物材料性能的影响。结果表明:粉煤灰地质聚合物的凝结时间随着印染污泥掺量增加而缩短,在掺量高于20%时,由于凝结时间太短而不利于成型;其强度在掺量为10%左右时略有提高,而当掺量大于20%时,强度极大地下降;对掺量20%的试样进行重金属浸出含量测试发现,该地质聚合物具有很好的封固重金属的性能,试样重金属浸出含量远低于限量的要求。

  20. The Spider and the Fly

    Science.gov (United States)

    Mellinger, Keith E.; Viglione, Raymond

    2012-01-01

    The Spider and the Fly puzzle, originally attributed to the great puzzler Henry Ernest Dudeney, and now over 100 years old, asks for the shortest path between two points on a particular square prism. We explore a generalization, find that the original solution only holds in certain cases, and suggest how this discovery might be used in the…

  1. Electrodialytic treatment of fly ash

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Pedersen, Anne Juul; Kirkelund, Gunvor Marie

    Heavy metals are removed from the fly ashes by an electrodialytic treatment with the aim of up-grading the ashes for reuse in stead of disposal in landfill.A great potential for upgrading of bio- and waste incineration ashes by electrodialytic treatment exists. In the future, the applicability...

  2. DURABILITY OF HARDENED FLY ASH PASTE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The mechanical properties and durability ( mainly frost-resistance and carbonation resistance ) of fly ash-CaO-CaSO4 .2H2O hardened paste are studied. The relationship among durability of harden ed fly ash paste, the quantity and distribution of hydrates and the initial p aste texture of hardened fly ash paste is presented.

  3. Louse flies on birds of Baja California.

    Science.gov (United States)

    Tella, J L; Rodríguez-Estrella, R; Blanco, G

    2000-01-01

    Louse flies were collected from 401 birds of 32 species captured in autumn of 1996 in Baja California Sur (Mexico). Only one louse fly species (Microlynchia pusilla) was found. It occurred in four of the 164 common ground doves (Columbina passerina) collected. This is a new a host species for this louse fly.

  4. Flies and Campylobacter infection of broiler flocks

    DEFF Research Database (Denmark)

    Hald, Birthe; Skovgård, Henrik; Bang, Dang Duong

    2004-01-01

    A total of 8.2% of flies caught outside a broiler house in Denmark had the potential to transmit Campylobacter jejuni to chickens, and hundreds of flies per day passed through the ventilation system into the broiler house. Our study suggests that flies may be an important source of Campylobacter...

  5. Hierarchical zeolites from class F coal fly ash

    Science.gov (United States)

    Chitta, Pallavi

    Fly ash, a coal combustion byproduct is classified as types class C and class F. Class C fly ash is traditionally recycled for concrete applications and Class F fly ash often disposed in landfills. Class F poses an environmental hazard due to disposal and leaching of heavy metals into ground water and is important to be recycled in order to mitigate the environmental challenges. A major recycling option is to reuse the fly ash as a low-cost raw material for the production of crystalline zeolites, which serve as catalysts, detergents and adsorbents in the chemical industry. Most of the prior literature of fly ash conversion to zeolites does not focus on creating high zeolite surface area zeolites specifically with hierarchical pore structure, which are very important properties in developing a heterogeneous catalyst for catalysis applications. This research work aids in the development of an economical process for the synthesis of high surface area hierarchical zeolites from class F coal fly ash. In this work, synthesis of zeolites from fly ash using classic hydrothermal treatment approach and fusion pretreatment approach were examined. The fusion pretreatment method led to higher extent of dissolution of silica from quartz and mullite phases, which in turn led to higher surface area and pore size of the zeolite. A qualitative kinetic model developed here attributes the difference in silica content to Si/Al ratio of the beginning fraction of fly ash. At near ambient crystallization temperatures and longer crystallization times, the zeolite formed is a hierarchical faujasite with high surface area of at least 360 m2/g. This work enables the large scale recycling of class F coal fly ash to produce zeolites and mitigate environmental concerns. Design of experiments was used to predict surface area and pore sizes of zeolites - thus obviating the need for intense experimentation. The hierarchical zeolite catalyst supports tested for CO2 conversion, yielded hydrocarbons

  6. FliO Regulation of FliP in the Formation of the Salmonella enterica Flagellum

    OpenAIRE

    Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Samatey, Fadel A.

    2010-01-01

    The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extrageni...

  7. Illinois basin coal fly ashes. 1. Chemical characterization and solubility

    Science.gov (United States)

    Roy, W.R.; Griffin, R.A.; Dickerson, D.R.; Schuller, R.M.; Martin, S.M.C.

    1984-01-01

    Twelve precipitator-collected fly ash samples (nine derived from high-sulfur Illinois Basin coals and three from Western U.S. coals) were found to contain a variety of paraffins, aryl esters, phenols, and polynuclear aromatic hydrocarbons including phenanthrene, pyrene, and chrysene but all at very low concentrations. Less than 1% of the organic carbon in the samples was extractable into benzene. Solubility studies with a short-term (24-h) extraction procedure and a long-term (20-week) procedure indicate that the inorganic chemical composition of some types of fly ash effluent is time dependent and may be most toxic to aquatic ecosystems when initially mixed with water and pumped to disposal ponds. Some acidic, high-Cd fly ashes would be classified as hazardous wastes if coal ash was included in this waste category by future RCRA revisions. ?? 1984 American Chemical Society.

  8. High Step-Up 3-Phase Rectifier with Fly-Back Cells and Switched Capacitors for Small-Scaled Wind Generation Systems

    Directory of Open Access Journals (Sweden)

    Yi-Feng Wang

    2015-04-01

    Full Text Available This paper proposes and discusses a novel AC/DC converter suitable for small-scaled wind power generation system applications. By introducing flyback cells into the three-phase single-switch Boost circuit, the proposed converter is designed as single-stage and has both rectification and high step-up power conversion functions. It is able to obtain high voltage gain at low input voltage level, and high efficiency, low total harmonic distortion (THD at rated power. The inherent power factor correction (PFC is also determined, and can reach 0.99. Besides, since no electrolytic capacitor is employed and high voltage gain is achieved, the converter can also collect weak power at low input voltage in combination with energy storage devices, and contribute to a better low-wind-speed/low-power performance. Finally, a 400 W prototype is built to verify the theoretical analysis, and its efficiency is 87.6%, while THD is 7.4% at rated power.

  9. Breeding sites of Phlebotomus sergenti, the sand fly vector of cutaneous leishmaniasis in the Judean Desert.

    Directory of Open Access Journals (Sweden)

    Aviad Moncaz

    Full Text Available Phlebotomine sand flies transmit Leishmania, phlebo-viruses and Bartonella to humans. A prominent gap in our knowledge of sand fly biology remains the ecology of their immature stages. Sand flies, unlike mosquitoes do not breed in water and only small numbers of larvae have been recovered from diverse habitats that provide stable temperatures, high humidity and decaying organic matter. We describe studies designed to identify and characterize sand fly breeding habitats in a Judean Desert focus of cutaneous leishmaniasis. To detect breeding habitats we constructed emergence traps comprising sand fly-proof netting covering defined areas or cave openings. Large size horizontal sticky traps within the confined spaces were used to trap the sand flies. Newly eclosed male sand flies were identified based on their un-rotated genitalia. Cumulative results show that Phlebotomus sergenti the vector of Leishmania tropica rests and breeds inside caves that are also home to rock hyraxes (the reservoir hosts of L. tropica and several rodent species. Emerging sand flies were also trapped outside covered caves, probably arriving from other caves or from smaller, concealed cracks in the rocky ledges close by. Man-made support walls constructed with large boulders were also identified as breeding habitats for Ph. sergenti albeit less important than caves. Soil samples obtained from caves and burrows were rich in organic matter and salt content. In this study we developed and put into practice a generalized experimental scheme for identifying sand fly breeding habitats and for assessing the quantities of flies that emerge from them. An improved understanding of sand fly larval ecology should facilitate the implementation of effective control strategies of sand fly vectors of Leishmania.

  10. Spi-1, Fli-1 and Fli-3 (miR-17-92 oncogenes contribute to a single oncogenic network controlling cell proliferation in friend erythroleukemia.

    Directory of Open Access Journals (Sweden)

    Samer Kayali

    Full Text Available Clonal erythroleukemia developing in susceptible mice infected by Friend virus complex are associated with highly recurrent proviral insertions at one of three loci called Spi-1, Fli-1 or Fli-3, leading to deregulated expression of oncogenic Spi-1 or Fli-1 transcription factors or miR-17-92 miRNA cluster, respectively. Deregulated expression of each of these three oncogenes has been independently shown to contribute to cell proliferation of erythroleukemic clones. Previous studies showed a close relationship between Spi-1 and Fli-1, which belong to the same ETS family, Spi-1 activating fli-1 gene, and both Spi-1 and Fli-1 activating multiple common target genes involved in ribosome biogenesis. In this study, we demonstrated that Spi-1 and Fli-1 are also involved in direct miR-17-92 transcriptional activation through their binding to a conserved ETS binding site in its promoter. Moreover, we demonstrated that physiological re-expression of exogenous miR-17 and miR-20a are able to partially rescue the proliferation loss induced by Fli-1 knock-down and identified HBP1 as a target of these miRNA in erythroleukemic cells. These results establish that three of the most recurrently activated oncogenes in Friend erythroleukemia are actually involved in a same oncogenic network controlling cell proliferation. The putative contribution of a similar ETS-miR-17-92 network module in other normal or pathological proliferative contexts is discussed.

  11. Spi-1, Fli-1 and Fli-3 (miR-17-92) oncogenes contribute to a single oncogenic network controlling cell proliferation in friend erythroleukemia.

    Science.gov (United States)

    Kayali, Samer; Giraud, Guillaume; Morlé, François; Guyot, Boris

    2012-01-01

    Clonal erythroleukemia developing in susceptible mice infected by Friend virus complex are associated with highly recurrent proviral insertions at one of three loci called Spi-1, Fli-1 or Fli-3, leading to deregulated expression of oncogenic Spi-1 or Fli-1 transcription factors or miR-17-92 miRNA cluster, respectively. Deregulated expression of each of these three oncogenes has been independently shown to contribute to cell proliferation of erythroleukemic clones. Previous studies showed a close relationship between Spi-1 and Fli-1, which belong to the same ETS family, Spi-1 activating fli-1 gene, and both Spi-1 and Fli-1 activating multiple common target genes involved in ribosome biogenesis. In this study, we demonstrated that Spi-1 and Fli-1 are also involved in direct miR-17-92 transcriptional activation through their binding to a conserved ETS binding site in its promoter. Moreover, we demonstrated that physiological re-expression of exogenous miR-17 and miR-20a are able to partially rescue the proliferation loss induced by Fli-1 knock-down and identified HBP1 as a target of these miRNA in erythroleukemic cells. These results establish that three of the most recurrently activated oncogenes in Friend erythroleukemia are actually involved in a same oncogenic network controlling cell proliferation. The putative contribution of a similar ETS-miR-17-92 network module in other normal or pathological proliferative contexts is discussed.

  12. DETERMINING THE ROLE OF INDIVIDUAL FLY ASH PARTICLES IN INFLUENCING THE VARIATION IN THE OVERALL PHYSICAL, MORPHOLOGICAL, AND CHEMICAL PROPERTIES OF FLY ASH

    Directory of Open Access Journals (Sweden)

    Usman Haider

    2016-08-01

    Full Text Available The properties of fly ashes vary because of the differences in the properties of their individual particles, and the determination of variation in these properties is of interest to the industries which use pulverized raw fly ash in applications, such as in cementitious materials and in the recovery of certain rare elements from raw fly ash. To investigate the differences in individual particles, four pulverized raw fly ashes from thermal power plants of the Czech Republic were used in this research. It was observed from FE-SEM that all four fly ashes consist of glassy hollow spherical, solid spherical, porous spherical, bright spherical, porous slaggy and compact slaggy particles. Box and whisker diagrams were plotted from the data of EDX individual particle analyses, which showed that the data of percentages for the Si, Al, and Fe elements is more scattered as compared to other elements. It was further observed from ternary phase diagrams and pseudo coloured images, that nature of fly ash particles changes from alumino silicate glassy to alumino silicate calcite metallic to pure ferro-metallic,where glassy particles showed high percentages and pure calcite particles were absent in fly ashes. Furthermore, a comparison between the XRF, the EDX total area analyses, showed that the EDX individual particle analysis gives more realistic and reliable data with median, mean, and the standard deviation for percentages of each element present in the fly ashes.

  13. Large-Eddy Simulations of Flapping-Induced Lift Enhancement

    Science.gov (United States)

    Franck, Jennifer; Swartz, Sharon; Breuer, Kenneth

    2011-11-01

    This work isolates the heaving motion of flapping flight in order to numerically investigate the fluid-structure interaction at Reynolds numbers relevant to birds and bats. Although there has been much focus on insect flight, larger vertebrates fly at a higher Reynolds number, which leads to different dynamics in terms of flow separation, reattachment, and high-lift mechanisms. In this work, an incompressible large-eddy simulation is used to simulate the periodic heaving of a flat plate at various angles of attack. It is found that the heaving motion can increase the average lift when compared with the steady flow, more so than is expected from the relative angle of attack. The additional lift is attributed to the vortex dynamics at the leading edge. The lift enhancement and flow features are compared with experimental results.

  14. FliO Regulation of FliP in the Formation of the Salmonella enterica Flagellum

    Science.gov (United States)

    Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Samatey, Fadel A.

    2010-01-01

    The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO43–125 or FliO1–95 was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO43–125, should contain beta-structure and alpha-helices. FliO43–125-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners. PMID:20941389

  15. FliO regulation of FliP in the formation of the Salmonella enterica flagellum.

    Directory of Open Access Journals (Sweden)

    Clive S Barker

    2010-09-01

    Full Text Available The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO₄₃-₁₂₅ or FliO₁-₉₅ was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO₄₃-₁₂₅, should contain beta-structure and alpha-helices. FliO₄₃-₁₂₅-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners.

  16. Evaluation of cocomposted coal fly ash on dynamics of microbial populations and heavy metal uptake

    Energy Technology Data Exchange (ETDEWEB)

    Vallini, G.; Vaccari, F.; Pera, A.; Agnolucci, M.; Scatena, S.; Varallo, G. [University of Verona, Verona (Italy). Science and Technology Dept.

    1999-06-01

    Vicia faba, in a pot experiment with sandy and clayey soils under greenhouse conditions, was checked for growth response to different amendments with coal alkaline fly ash or cocomposted fly ash mixed with lignocellulosic residues. Soil microbial populations, pH and electrical conductivity as well as heavy metal uptake by plants were monitored. At rates of five and ten percent (on a dry matter basis) in both soils, neither fly ash alone nor cocomposted fly ash exerted any negative effect. Plant biomass production was not influenced in either clayey or sandy soil. Alkaline fly ash did not promote microbial growth when applied alone to the soils. However, cocomposted fly ash generally increased bacterial and actinomycetes counts in both soils. Fungi were not affected by ash. Due to the increase of soil pH by alkaline fly ash or cocomposted fly ash, plant uptake of heavy metals was depressed in the sandy soil. Heavy metal mobility did not cause change in the clayey soil where a high buffering capacity mitigated the effects of fly ash amendments.

  17. The genetic polymorphisms and colonization process of olive fly populations in Turkey.

    Science.gov (United States)

    Dogaç, Ersin; Kandemir, İrfan; Taskin, Vatan

    2013-01-01

    The olive fruit fly, Bactrocera oleae, is the most important pest of olives in olive growing regions worldwide, especially in the Mediterranean basin and North America. Despite the economic importance of the olive fly, the colonization route of this species is unclear. We used nuclear microsatellite markers and mitochondrial DNA to provide information about the population structure and invasion route of olive fly populations in Turkey, as representative of the Eastern Mediterranean region. Adult fly samples were collected from 38 sublocations covering all olive growing regions in Turkey. The simple sequence variability data revealed a significant genetic variability in olive fly populations and a certain degree of differentiation between Mediterranean and Aegean populations. Mediterranean populations harbor higher levels of microsatellite variation than Aegean populations, which points to the eastern part of the Mediterranean as the putative source of invasion. mtDNA results suggest olive flies from the western part of Turkey are closely related to Italo-Aegean flies of the Mediterranean basin and the olive fly populations have invaded the northern part of the Mediterranean basin through western Turkey. In addition, finding specific American haplotypes in high frequencies might indicate that Turkey is the possible source of American olive fly populations. In order to more precisely characterize the population structure and invasion routes of this organism, more DNA-based sequence analysis should be carried out worldwide.

  18. Augmenting laboratory rearing of stable fly (diptera: muscidae) larvae with ammoniacal salts

    Science.gov (United States)

    Stable flies are serious pests of livestock. The immature stages develop in decaying materials which frequently have high ammonium content. We added various ammonium salts to our laboratory stable fly rearing medium and measured their effect on size and survival as well as the physical properties o...

  19. Selection for Resistance to Imidacloprid in the House Fly (Diptera: Muscidae)

    Science.gov (United States)

    House flies, Musca domestica L., continue to be a primary pest of livestock facilities worldwide. This pest also has shown a propensity for pesticide resistance development when under high selection pressures. In this study a house fly strain, FDm was created by a 20% contribution from each of fiv...

  20. Aerodynamics of the Smallest Flying Insects

    CERN Document Server

    Miller, Laura A; Hedrick, Ty; Robinson, Alice; Santhanakrishnan, Arvind; Lowe, Audrey

    2011-01-01

    We present fluid dynamics videos of the flight of some of the smallest insects including the jewel wasp, \\textit{Ampulex compressa}, and thrips, \\textit{Thysanoptera} spp. The fruit fly, \\textit{Drosophila melanogaster}, is large in comparison to these insects. While the fruit fly flies at $Re \\approx 120$, the jewel wasp flies at $Re \\approx 60$, and thrips flies at $Re \\approx 10$. Differences in the general structures of the wakes generated by each species are observed. The differences in the wakes correspond to changes in the ratio of lift forces (vertical component) to drag forces (horizontal component) generated.

  1. Characteristics of the ultrafine component of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    M.R. Jones; A. McCarthy; A.P.P.G. Booth [University of Dundee, Dundee (United Kingdom). Concrete Technology Unit, Division of Civil Engineering

    2006-11-15

    Post-production processing of fly ash (FA) is an important issue for its use in concrete. Given (i) the need for environmental protection, (ii) the measures being applied on coal-fired power stations to reduce acidic gas emissions and (iii) the effect these have had on fly ash quality, there is a need to consider efficient post-production processing to enhance fly ash characteristics. This is particularly important for fly ash used as a cement in concrete production, since the additional residual carbon content and decreased fineness significantly affect its quality. This paper details the material characteristics of an ultrafine, low-lime fly ash (UF-FA), produced, in this case, by processing a coarse FA (referred to as parent FA) from a bituminous coal-fired power station via air-cyclonic separation. The UF-FA is shown to have much improved material characteristics compared to the parent FA in terms of morphology, mineralogy and chemical composition. Further results are presented on the effect of UF-FA on the properties of cementitious systems. Improved consistence and compressive strengths of combined Portland cement (PC) and UF-FA mortars were observed, whilst enhanced PC hydration and a high degree of FA reactivity were concluded from heat of hydration measurements and calcium hydroxide contents of pastes. 20 refs., 10 figs., 1 tab.

  2. The utilisation of fly ash in CO2 mineral carbonation

    Directory of Open Access Journals (Sweden)

    Jaschik Jolanta

    2016-03-01

    Full Text Available The fixation of CO2 in the form of inorganic carbonates, also known as mineral carbonation, is an interesting option for the removal of carbon dioxide from various gas streams. The captured CO2 is reacted with metal-oxide bearing materials, usually naturally occurring minerals. The alkaline industrial waste, such as fly ash can also be considered as a source of calcium or magnesium. In the present study the solubility of fly ash from conventional pulverised hard coal fired boilers, with and without desulphurisation products, and fly ash from lignite fluidised bed combustion, generated by Polish power stations was analysed. The principal objective was to assess the potential of fly ash used as a reactant in the process of mineral carbonation. Experiments were done in a 1 dm3 reactor equipped with a heating jacket and a stirrer. The rate of dissolution in water and in acid solutions was measured at various temperatures (20 - 80ºC, waste-to-solvent ratios (1:100 - 1:4 and stirrer speeds (300 - 1100 min-1. Results clearly show that fluidised lignite fly ash has the highest potential for carbonation due to its high content of free CaO and fast kinetics of dissolution, and can be employed in mineral carbonation of CO2.

  3. Fate of pharmaceuticals and pesticides in fly larvae composting

    Energy Technology Data Exchange (ETDEWEB)

    Lalander, C., E-mail: cecilia.lalander@slu.se [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Senecal, J.; Gros Calvo, M. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Ahrens, L.; Josefsson, S.; Wiberg, K. [Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (Sweden); Vinnerås, B. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden)

    2016-09-15

    A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (< 10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. - Highlights: • Degradation of pharmaceuticals and pesticides in fly larvae composting (FLC). • Half-life considerably shorter in FLC than in control with no larvae. • Half-life of carbamazepine was less than two days in FLC. • No bioaccumulation in larvae detected. • FLC could impede the spreading of pharmaceuticals and pesticide in the environment.

  4. Synthesis of Zeolites by Alkaline Activation of Fly Ash

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In terms of mineral transformation, and chemical composition of acid-soluble component as a function of reaction time, the effect of alkaline solution on zeolite-like fly ash was studied by employing fly ash and NaOH solution as starting materials. When fly ash and 1€? 0mol/L NaOH solution were processed at 100℃ for 24h with 1:10 W/S rat io in a relatively closed system, powder XRD patterns of resulting pro ducts indicated the formation of various zeolites. Zeolite P crystalli zed early at low alkaline concentration, which was replaced then by ze olites X and A. At high concentration, hydroxy sodalite was the only n ew phase. Quartz, in fly ash and NaOH solution system, gradually disso lved, and mullite, however, remained stable. It was concluded that, wi th Al/Si and Na/Si finally reaching equilibrium in molar ratio, compos ition of starting mixtures affects the crystallization of zeolite from fly ash.

  5. Binocular interactions underlying the classic optomotor responses of flying flies

    Directory of Open Access Journals (Sweden)

    Brian J Duistermars

    2012-02-01

    Full Text Available In response to imposed course deviations, the fast optomotor reactions of animals reduce motion blur and facilitate the maintenance of stable body posture. In flies, the monocular front-to-back (progressive and back-to-front (regressive visual motion components generated by horizontal rotation are selectively encoded, respectively, by homo and heterolateral motion sensitive circuits in the third optic ganglion, the lobula plate. To investigate the strength of such inter-ocular interactions and their role in compensatory sensory-motor transformations, we utilize a virtual reality flight simulator to record optomotor reactions by tethered flying flies in response to imposed binocular and monocular visual rotation. With stimulus parameters generating large contrast insensitive optomotor responses to binocular rotation, we find that responses to monocular progressive motion are larger than those to panoramic rotation but contrast sensitive. Conversely, responses to monocular regressive motion are slower than those to rotation and peak at the lowest tested contrast. Together our results suggest that contrast insensitive optomotor responses to binocular rotation result from the dynamic interplay of contralateral inhibitory as well as excitatory circuit interactions and serve to maintain a stable optomotor equilibrium across a range of visual contrasts.

  6. 基于灰关联熵分析的大掺量粉煤灰混凝土导热性能影响因素研究%Grey Correlation Entropy Method to Analyze Thermal Properties of High Volume Fly Ash Concrete

    Institute of Scientific and Technical Information of China (English)

    哈斯图雅

    2015-01-01

    为了探究各因素对大掺量粉煤灰混凝土导热性能的影响,通过试验,以导热系数为主要导热性能指标,运用灰关联熵分析的手段,定量分析了水胶比、粉煤灰掺量、减水剂掺量、砂率和骨料干湿状态对大掺量粉煤灰混凝土导热系数影响的显著程度。经计算分析得出:对大掺量粉煤灰混凝土导热性能影响最大的是砂率,其次依次为粉煤灰掺量、水胶比、减水剂掺量和骨料干湿状态。在进行大掺量粉煤灰混凝土配合比设计时,从导热性能方面考虑,必须严格控制砂率。%In order to explore the factors that influence the performance of high volume fly ash concrete heat conduction,through the test,use conductivity as the mainly thermal performance indicators, using the grey relation entropy analysis method,to analysis the effect of degree of water binder ratio,fly ash content,water reducing agent dosage,sand ratio and aggregate in dry and wet conditions to high vol-ume fly ash concrete heat conduction quantitativiy.Through calculation and analysis:the most significant factor influence on performance of high volume fly ash concrete heat conduction is sand rate,followed by the amount of fly ash,water binder ratio,dosage of water reducer and aggregate in dry and wet condi-tions.In high volume fly ash concrete mix design,considering thethermal conductivity performance,must strictly control therate of sand.

  7. Stability and leaching of cobalt smelter fly ash

    DEFF Research Database (Denmark)

    Vítková, Martina; Hyks, Jiri; Ettler, Vojtěch

    2013-01-01

    The leaching behaviour of fly ash from a Co smelter situated in the Zambian Copperbelt was studied as a function of pH (5–12) using the pH-static leaching test (CEN/TS 14997). Various experimental time intervals (48h and 168h) were evaluated. The leaching results were combined with the ORCHESTRA...... elements, the released concentrations were very similar after 48h and 168h, indicating near-equilibrium conditions in the system. Calcite, clinopyroxenes, quartz and amorphous phases predominated in the fly ash. Various metallic sulfides, alloys and the presence of Cu, Co and Zn in silicates and glass were...... and Cu. However, there is a high risk of Co, Cu, Pb and Zn mobility in the acidic soils around the smelter facility. Therefore, potential local options for “stabilisation” of the fly ash were evaluated on the basis of the modelling results using the PHREEQC code....

  8. Analysis of Content of Selected Critical Elements in Fly Ash

    Directory of Open Access Journals (Sweden)

    Makowska Dorota

    2016-03-01

    Full Text Available Pursuant to the new mineral policy of the European Union, searching for new sources of raw materials is required. Coal fly ash has long been considered as a potential source of a number of critical elements. Therefore, it is important to monitor the contents of the critical elements in fly ash from coal combustion. The paper presents the results of examinations of the contents of selected elements, i.e. beryllium, cobalt, chromium and germanium in fly ash from Polish power plants. The results of the conducted investigations indicate that the examined ash samples from bituminous coal combustion cannot be treated as a potential source of the analysed critical elements. The content of these elements in ash, though slightly higher than their average content in the sedimentary rocks, is, however, not high enough to make their recovery technologically and economically justified at this moment.

  9. Laser system for identification, tracking, and control of flying insects.

    Science.gov (United States)

    Mullen, Emma R; Rutschman, Phillip; Pegram, Nathan; Patt, Joseph M; Adamczyk, John J; Johanson, 3ric

    2016-05-30

    Flying insects are common vectors for transmission of pathogens and inflict significant harm to humans and agricultural production in many parts of the world. We present proof of principle for an optical system capable of highly specific vector control. This system utilizes a combination of optical sources, detectors, and sophisticated software to search, detect, and identify flying insects in real-time, with the capability of eradication using a lethal laser pulse. We present data on two insect species to show species distinction; Diaphorina citri, a vector of the causal agent of citrus greening disease, and Anopheles stephensi, a malaria vector.

  10. CO2 uptake capacity of coal fly ash

    DEFF Research Database (Denmark)

    Mazzella, Alessandro; Errico, Massimiliano; Spiga, Daniela

    2016-01-01

    -solid carbonation treatment on coal fly ash in order to assess the potential of the process in terms of sequestration of CO2 as well as its influence on the leaching behavior of metals and soluble salts. Laboratory tests, performed under different pressure and temperature conditions, showed that in the pressure......% corresponding to a maximum carbonation efficiency of 74%, estimated on the basis of the initial CaO content. The high degree of ash carbonation achieved in the present research, which was conducted under mild conditions, without add of water and without stirring, showed the potential use of coal fly ash in CO2...

  11. Energetic cost of bot fly parasitism in free-ranging eastern chipmunks.

    Science.gov (United States)

    Careau, Vincent; Thomas, Donald W; Humphries, Murray M

    2010-02-01

    The energy and nutrient demands of parasites on their hosts are frequently invoked as an explanation for negative impacts of parasitism on host survival and reproductive success. Although cuterebrid bot flies are among the physically largest and most-studied insect parasites of mammals, the only study conducted on metabolic consequences of bot fly parasitism revealed a surprisingly small effect of bot flies on host metabolism. Here we test the prediction that bot fly parasitism increases the resting metabolic rate (RMR) of free-ranging eastern chipmunks (Tamias striatus), particularly in juveniles who have not previously encountered parasites and have to allocate energy to growth. We found no effect of bot fly parasitism on adults. In juveniles, however, we found that RMR strongly increased with the number of bot fly larvae hosted. For a subset of 12 juveniles during a year where parasite prevalence was particularly high, we also compared the RMR before versus during the peak of bot fly prevalence, allowing each individual to act as its own control. Each bot fly larva resulted in a approximately 7.6% increase in the RMR of its host while reducing juvenile growth rates. Finally, bot fly parasitism at the juvenile stage was positively correlated with adult stage RMR, suggesting persistent effects of bot flies on RMR. This study is the first to show an important effect of bot fly parasitism on the metabolism and growth of a wild mammal. Our work highlights the importance of studying cost of parasitism over multiple years in natural settings, as negative effects on hosts are more likely to emerge in periods of high energetic demand (e.g. growing juveniles) and/or in harsh environmental conditions (e.g. low food availability).

  12. Flying over an infected landscape: distribution of highly pathogenic avian influenza H5N1 risk in South Asia and satellite tracking of wild waterfowl

    Science.gov (United States)

    Gilbert, Marius; Newman, Scott H.; Takekawa, John Y.; Loth, Leo; Biradar, Chandrashekhar; Prosser, Diann J.; Balachandran, Sivananinthaperumal; Rao, Mandava Venkata Subba; Mundkur, Taej; Yan, Baoping; Xing, Zhi; Hou, Yuansheng; Batbayar, Nyambayar; Tseveenmayadag, Natsagdorj; Hogerwerf, Lenny; Slingenbergh, Jan; Xiao, Xiangming

    2010-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus persists in Asia, posing a threat to poultry, wild birds, and humans. Previous work in Southeast Asia demonstrated that HPAI H5N1 risk is related to domestic ducks and people. Other studies discussed the role of migratory birds in the long distance spread of HPAI H5N1. However, the interplay between local persistence and long-distance dispersal has never been studied. We expand previous geospatial risk analysis to include South and Southeast Asia, and integrate the analysis with migration data of satellite-tracked wild waterfowl along the Central Asia flyway. We find that the population of domestic duck is the main factor delineating areas at risk of HPAI H5N1 spread in domestic poultry in South Asia, and that other risk factors, such as human population and chicken density, are associated with HPAI H5N1 risk within those areas. We also find that satellite tracked birds (Ruddy Shelduck and two Bar-headed Geese) reveal a direct spatio-temporal link between the HPAI H5N1 hot-spots identified in India and Bangladesh through our risk model, and the wild bird outbreaks in May,June,July 2009 in China(Qinghai Lake), Mongolia, and Russia. This suggests that the continental-scale dynamics of HPAI H5N1 are structured as a number of persistence areas delineated by domestic ducks, connected by rare transmission through migratory waterfowl.

  13. Mitochondrial DNA markers reveal high genetic diversity but low genetic differentiation in the black fly Simulium tani Takaoka & Davies along an elevational gradient in Malaysia.

    Directory of Open Access Journals (Sweden)

    Van Lun Low

    Full Text Available The population genetic structure of Simulium tani was inferred from mitochondria-encoded sequences of cytochrome c oxidase subunits I (COI and II (COII along an elevational gradient in Cameron Highlands, Malaysia. A statistical parsimony network of 71 individuals revealed 71 haplotypes in the COI gene and 43 haplotypes in the COII gene; the concatenated sequences of the COI and COII genes revealed 71 haplotypes. High levels of genetic diversity but low levels of genetic differentiation were observed among populations of S. tani at five elevations. The degree of genetic diversity, however, was not in accordance with an altitudinal gradient, and a Mantel test indicated that elevation did not have a limiting effect on gene flow. No ancestral haplotype of S. tani was found among the populations. Pupae with unique structural characters at the highest elevation showed a tendency to form their own haplotype cluster, as revealed by the COII gene. Tajima's D, Fu's Fs, and mismatch distribution tests revealed population expansion of S. tani in Cameron Highlands. A strong correlation was found between nucleotide diversity and the levels of dissolved oxygen in the streams where S. tani was collected.

  14. Mitochondrial DNA markers reveal high genetic diversity but low genetic differentiation in the black fly Simulium tani Takaoka & Davies along an elevational gradient in Malaysia.

    Science.gov (United States)

    Low, Van Lun; Adler, Peter H; Takaoka, Hiroyuki; Ya'cob, Zubaidah; Lim, Phaik Eem; Tan, Tiong Kai; Lim, Yvonne A L; Chen, Chee Dhang; Norma-Rashid, Yusoff; Sofian-Azirun, Mohd

    2014-01-01

    The population genetic structure of Simulium tani was inferred from mitochondria-encoded sequences of cytochrome c oxidase subunits I (COI) and II (COII) along an elevational gradient in Cameron Highlands, Malaysia. A statistical parsimony network of 71 individuals revealed 71 haplotypes in the COI gene and 43 haplotypes in the COII gene; the concatenated sequences of the COI and COII genes revealed 71 haplotypes. High levels of genetic diversity but low levels of genetic differentiation were observed among populations of S. tani at five elevations. The degree of genetic diversity, however, was not in accordance with an altitudinal gradient, and a Mantel test indicated that elevation did not have a limiting effect on gene flow. No ancestral haplotype of S. tani was found among the populations. Pupae with unique structural characters at the highest elevation showed a tendency to form their own haplotype cluster, as revealed by the COII gene. Tajima's D, Fu's Fs, and mismatch distribution tests revealed population expansion of S. tani in Cameron Highlands. A strong correlation was found between nucleotide diversity and the levels of dissolved oxygen in the streams where S. tani was collected.

  15. Incorporation of treated straw and wood fly ash into clay building brick

    DEFF Research Database (Denmark)

    Chen, Wan; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2016-01-01

    High Cd content in straw and wood fly ash, generated from biomass-fired power plants, prohibits its recycling as fertilizer spreading on the landfilled. To improve and alter the current mainstream of fly ash treatment by landfilling, different approaches were tried for treatment of straw and wood...... fly ash, such as washing with water to quickly recover the highly soluble salts (mainly K and Cl), and treatment of the washed fly ash with elevated heavy metal content resulted from washing by electrodialytic remediation (EDR). The finding that SiO2 (quartz) accounted for a significant portion...... in the treated ash, suggests the possibility of the ash reuse in sintered clay bricks. In this study, the straw and wood fly ash treated by washing and EDR was incorporated into yellow clay bricks at different substitution rates. The properties of the clay-ash bricks were studied in terms of shrinkage, water...

  16. Geopolymer Mortar with Fly Ash

    Directory of Open Access Journals (Sweden)

    Saloma

    2016-01-01

    Full Text Available The cement industry accounts for about 7% of all CO2 emissions caused by humans. Therefore, it is necessary to find another material in order to support sustainable material. An alternative way is replacing cement material with alternative material as fly ash. Fly ash as binder need to be added alkaline activator in the form of sodium silicate (Na2SiO3 or potassium silicate (K2SiO3 and sodium hydroxide (NaOH or potassium hydroxide (KOH. The purpose of this research is to analyze the effect of activator liquid concentration on geopolymer mortar properties and to know the value of compressive strength. Molarity variation of NaOH are 8, 12, 14, and 16 M with ratio of Na2SiO3/NaOH = 1.0. Ratio of sand/fly ash = 2.75 and ratio of activator/fly ash = 0.8. The cube-shaped specimen 50 × 50 × 50 mm is cured by steam curing with a temperature of 60°C for 48 hours. The experimental result of fresh mortar reported that the molarity of NaOH affect the slump flow and setting time, higher of NaOH produces the smaller value of slump and the faster time of setting. The experimental of density results reported that the increase of specific gravity when the molarity of NaOH increased. The experimental results of the compressive strength are showed that the maximum compressive strength of geopolymer mortar 14 M is 10.06 MPa and the lowest compressive strength produced by geopolymer mortar 8 M is 3.95 MPa. Testing the compressive strength of geopolymer mortar 16 M produces compressive strength lower than 14 M geopolymer mortar is 9.16 MPa.

  17. "Fly me to the moon"

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ China's first lunar probe Chang'e-I, named after a mythical Chinese goddess who, according to legend, made her home on the moon, blasted off on 24 October from the Xichang Satellite Launch Center in the southwestern province of Sichuan. In addition to making the dream cherished by Chinese people to fly to the moon come true, it is the first step into China's ambitious threestage moon mission, marking a new milestone in the country's space exploration history.

  18. Notes on flying and dying.

    Science.gov (United States)

    Meyer, B C

    1983-07-01

    Focused on selected details in the lives and creative works of Samuel Johnson, Edgar Allan Poe, and Houdini, this paper explores a seeming antinomy between claustrophobic annihilation and aviation. At first glance the latter appears as an antidote to the threat of entrapment and death. On a deeper level the distinction fades as the impression arises that in the examples cited, flying may represent an unconscious expression of a wish for death and ultimate reunion.

  19. Current Methods to Detoxify Fly Ash from Waste Incineration

    Energy Technology Data Exchange (ETDEWEB)

    Hallgren, Christine; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2004-07-01

    Fly ash from waste incineration contains large amounts of heavy metals and dioxins, which will cause a significant disposal problem within the coming years. The amount of fly ash produced in Sweden is currently approximately 60,000 tons/y. New technological options for the decontamination and/or inertization of incinerator fly ash are being developed with the objective of rendering a product that can be reused or, at least, be deposited at standard landfill sites with no risk. Many of these technologies have been tested at industrial scale or in pilot projects. The proposed alternatives include: Thermal treatments; Immobilization/stabilization by cement based techniques; Wet chemical treatments (extractions, immobilizations); Microbiological treatments. Of these, thermal treatments are the most promising solution. Depending on the temperature thermal treatments are classified in two main types: 1) low temperature (below 600 deg C) thermal treatments and 2) high temperature (above 1200 deg C) thermal treatments (vitrification). Most dioxins can be successfully destroyed at temperatures up to 400 deg C under oxygen deficient conditions and at temperatures up to 600 deg C under oxidising conditions. However most heavy metals remain in the fly ash after low temperature treatment. At a temperature of 900 deg C most heavy metals can also be removed in a 10% HCl atmosphere by forming volatile metal chlorides (CT-Fluapur process). During vitrification processes the fly ash melts and forms an inert glassy slag. The product does not leach any significant amount of heavy metals and is free from dioxin. The volume of the fly ash is significantly reduced. The product can be land filled at low costs or used as construction material. The properties of the product depend on the cooling process and on additives such as sand, limestone or waste glass. A series of vitrification methods at industrial size or in pilot scale using different furnaces are studied. Among these, plasma

  20. Flying To Mars

    Institute of Scientific and Technical Information of China (English)

    周铭杨

    2015-01-01

    <正>Do you know"Mars migration programme"by SpaceX?It’s an immigrant plan to a planet—Mars,Sounds incredible,isn’t it?After two-round tests,Li Dapeng,graduating from Handan NO.1 high school in 2001,was selected.There entered four Chinese in final test.To be more precise,Li is the only one who comes from the mainland of China.Last weekend,Li came to our school for a speech.Driven by

  1. Investigation on autoclaved fly-ash brick production technique

    Institute of Scientific and Technical Information of China (English)

    ZouJi

    2005-01-01

    The article through analyzing the raw material properties and the production process of the autociaved fly-ash building products, and every kinds of influencing factor on products quantity ,investigated the optimum parameter, such as optimum steam curingtechnique level, has got good expansion meaning.system etc, and indicated that the production line has high technique level, has got good expansion meaning.

  2. Screening coal combustion fly ashes for application in geopolymers

    NARCIS (Netherlands)

    Valcke, S.L.A.; Pipilikaki, P.; Sarabér, A.J.; Fischer, H.R.; Nugteren, H.W.

    2013-01-01

    Driven by cost and sustainability, secondary resource materials such as fly ash, blast furnace slag, and bottom ash are increasingly used for alternative types of concrete binders, such as geopolymers. Because secondary resources may be highly variable from the perspective of geopolymers, it is ofte

  3. A role for flies (Diptera) in the transmission of Campylobacter to broilers?

    Science.gov (United States)

    Royden, A; Wedley, A; Merga, J Y; Rushton, S; Hald, B; Humphrey, T; Williams, N J

    2016-11-01

    Campylobacter is the leading cause of bacterial diarrhoeal disease worldwide, with raw and undercooked poultry meat and products the primary source of infection. Colonization of broiler chicken flocks with Campylobacter has proved difficult to prevent, even with high levels of biosecurity. Dipteran flies are proven carriers of Campylobacter and their ingress into broiler houses may contribute to its transmission to broiler chickens. However, this has not been investigated in the UK. Campylobacter was cultured from 2195 flies collected from four UK broiler farms. Of flies cultured individually, 0·22% [2/902, 95% confidence interval (CI) 0-0·53] were positive by culture for Campylobacter spp. Additionally, 1293 flies were grouped by family and cultured in 127 batches: 4/127 (3·15%, 95% CI 0·11-6·19) from three broiler farms were positive for Campylobacter. Multilocus sequence typing of isolates demonstrated that the flies were carrying broiler-associated sequence types, responsible for human enteric illness. Malaise traps were used to survey the dipteran species diversity on study farms and also revealed up to 612 flies present around broiler-house ventilation inlets over a 2-h period. Therefore, despite the low prevalence of Campylobacter cultured from flies, the risk of transmission by this route may be high, particularly during summer when fly populations are greatest.

  4. Modes of thrust generation in flying animals

    Science.gov (United States)

    Luo, Haoxiang; Song, Jialei; Tobalske, Bret; Luo Team; Tobalske Team

    2016-11-01

    For flying animals in forward flight, thrust is usually much smaller as compared with weight support and has not been given the same amount of attention. Several modes of thrust generation are discussed in this presentation. For insects performing slow flight that is characterized by low advance ratios (i.e., the ratio between flight speed and wing speed), thrust is usually generated by a "backward flick" mode, in which the wings moves upward and backward at a faster speed than the flight speed. Paddling mode is another mode used by some insects like fruit flies who row their wings backward during upstroke like paddles (Ristroph et al., PRL, 2011). Birds wings have high advance ratios and produce thrust during downstroke by directing aerodynamic lift forward. At intermediate advance ratios around one (e.g., hummingbirds and bats), the animal wings generate thrust during both downstroke and upstroke, and thrust generation during upstroke may come at cost of negative weight support. These conclusions are supported by previous experiment studies of insects, birds, and bats, as well as our recent computational modeling of hummingbirds. Supported by the NSF.

  5. Burn Injury Arise From Flying Balloon Toys

    Directory of Open Access Journals (Sweden)

    Yalcin Kulahci

    2007-08-01

    Full Text Available Many of peoples are faced minor or major burn injuries in their life. Even the most widespread burn cause is flame injuries, too different burn cause pointed out in literature like Acetylen burns. The cases which imply in literature, mostly causes from explosion of high pressure acetylene tube, metal oxygene patch flame or carbide lamp using from cave explorers. An interesting acetylene burn cause in Turkey was publised by the authors. This cases was to come into being from flying toy balloons flame. 80 person was injured from flying toy ballons flame in a meeting in 2002. Although this potential risks of acetylene, helium have not any of some risk. But helium was provided from other countries and have more price. The injuries which caused from acetylene burns like 1st -2nd degree burns. Consequently that was known helium is more avaliable for using in toy sector, and never cause burn injuries like this. [TAF Prev Med Bull 2007; 6(4.000: 291-296

  6. Burn Injury Arise From Flying Balloon Toys

    Directory of Open Access Journals (Sweden)

    Yalcin Kulahci

    2007-08-01

    Full Text Available Many of peoples are faced minor or major burn injuries in their life. Even the most widespread burn cause is flame injuries, too different burn cause pointed out in literature like Acetylen burns. The cases which imply in literature, mostly causes from explosion of high pressure acetylene tube, metal oxygene patch flame or carbide lamp using from cave explorers. An interesting acetylene burn cause in Turkey was publised by the authors. This cases was to come into being from flying toy balloons flame. 80 person was injured from flying toy ballons flame in a meeting in 2002. Although this potential risks of acetylene, helium have not any of some risk. But helium was provided from other countries and have more price. The injuries which caused from acetylene burns like 1st -2nd degree burns. Consequently that was known helium is more avaliable for using in toy sector, and never cause burn injuries like this. [TAF Prev Med Bull. 2007; 6(4: 291-296

  7. On the Correlation between Air Content and Air Bubble Parameters Frost Resistance Performance of High Fly Ash Content Concrete%关于大掺量粉煤灰混凝土含气量、气泡参数表征抗冻能力相关性的探讨

    Institute of Scientific and Technical Information of China (English)

    艾红梅; 戴碧琳; 郭建华; 杨晨光

    2015-01-01

    鉴于冻融作用对大掺量粉煤灰混凝土( High Fly ash Content Concrete,HFCC)造成的破坏较为严重,对国内外的研究情况进行了分析,总结了现阶段大掺量粉煤灰混凝土抗冻性能的研究进展。主要对混凝土拌合物含气量和硬化混凝土气泡参数表征HFCC抗冻性的科学性和可行性进行了分析,并且对二者的相关性进行探讨。%Given the freeze-thaw effect on high fly ash content concrete ( HFCC ) is relatively serious,the paper analyzes the domestic and foreign research and summarizes the present research progress of antifreeze performance of concrete with high volume of fly ash. This paper mainly analyzes the science and feasibility of concrete mixture air content and hardened concrete bubble parameters HFCC frost resistance and explores the correlation between the two.

  8. 78 FR 31838 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: General...

    Science.gov (United States)

    2013-05-28

    ... for normal takeoff. The primary flight controls consist of hydraulically powered fly-by-wire elevators... envelope protection features include limitations on angle-of- attack, normal load factor, bank angle, pitch...

  9. 78 FR 5148 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: General...

    Science.gov (United States)

    2013-01-24

    ... for normal takeoff. The primary flight controls consist of hydraulically powered fly-by-wire elevators... envelope protection features include limitations on angle-of- attack, normal load factor, bank angle, pitch...

  10. High-Alpha Research Vehicle (HARV) longitudinal controller: Design, analyses, and simulation resultss

    Science.gov (United States)

    Ostroff, Aaron J.; Hoffler, Keith D.; Proffitt, Melissa S.; Brown, Philip W.; Phillips, Michael R.; Rivers, Robert A.; Messina, Michael D.; Carzoo, Susan W.; Bacon, Barton J.; Foster, John F.

    1994-01-01

    This paper describes the design, analysis, and nonlinear simulation results (batch and piloted) for a longitudinal controller which is scheduled to be flight-tested on the High-Alpha Research Vehicle (HARV). The HARV is an F-18 airplane modified for and equipped with multi-axis thrust vectoring. The paper includes a description of the facilities, a detailed review of the feedback controller design, linear analysis results of the feedback controller, a description of the feed-forward controller design, nonlinear batch simulation results, and piloted simulation results. Batch simulation results include maximum pitch stick agility responses, angle of attack alpha captures, and alpha regulation for full lateral stick rolls at several alpha's. Piloted simulation results include task descriptions for several types of maneuvers, task guidelines, the corresponding Cooper-Harper ratings from three test pilots, and some pilot comments. The ratings show that desirable criteria are achieved for almost all of the piloted simulation tasks.

  11. Integration effects of pylon geometry and rearward mounted nacelles for a high-wing transport

    Science.gov (United States)

    Carlson, John R.; Lamb, Milton

    1987-01-01

    Results of a wind-tunnel study of the effect of pylon cross-sectional shape and tow angle on airplane drag and an aft-mounted nacelle are presented. The 1/24-scale wide-body high-wing transport model was tested in the Langley 16-Foot Transonic Tunnel at free-stream Mach 0.7-0.8 and angles of attack from -3 to 4 degrees. A compression-type pylon is found to have the lowest drag at both Mach 0.7 and 0.8 and to be capable of suppressing the velocities in the inboard region of the pylon-wing junction, reducing the extent of supersonic flow and the probability of flow separation. It is also shown that the D-shaped aft-mounted nacelle has a low interference drag, as do previously tested circular nacelles in the same position.

  12. Integration effects of pylon geometry on a high-wing transport airplane

    Science.gov (United States)

    Carlson, John R.; Lamb, Milton

    1989-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the installation effects of a series of pylons that had differing cross-sectional shapes on the pressure distributions and aerodynamic characteristics of a 1/24-scale high wing transport. The tests were conducted at Mach numbers at 0.70 and 0.80 at angles of attack from -3 degrees to 4 degrees with the pylons tested at various toe angles between 5 degrees inboard and 5 degrees outboard. Results of this study indicate that the installed drag was lowest for the pylons with a compression pylon type design which kept the flow under the wing in the pylon/wing junction comparable to the clean wing velocities.

  13. Aerodynamic flow control of a high lift system with dual synthetic jet arrays

    Science.gov (United States)

    Alstrom, Robert Bruce

    Implementing flow control systems will mitigate the vibration and aeroacoustic issues associated with weapons bays; enhance the performance of the latest generation aircraft by reducing their fuel consumption and improving their high angle-of-attack handling qualities; facilitate steep climb out profiles for military transport aircraft. Experimental research is performed on a NACA 0015 airfoil with a simple flap at angle of attack of 16o in both clean and high lift configurations. The results of the active control phase of the project will be discussed. Three different experiments were conducted; they are Amplitude Modulated Dual Location Open Loop Control, Adaptive Control with Amplitude Modulation using Direct Sensor Feedback and Adaptive Control with Amplitude Modulation using Extremum Seeking Control. All the closed loop experiments are dual location. The analysis presented uses the spatial variation of the root mean square pressure fluctuations, power spectral density estimates, Fast Fourier Transforms (FFTs), and time frequency analysis which consists of the application of the Morlet and Mexican Hat wavelets. Additionally, during the course of high speed testing in the wind tunnel, some aeroacoustic phenomena were uncovered; those results will also be presented. A cross section of the results shows that the shape of the RMS pressure distributions is sensitive to forcing frequency. The application of broadband excitation in the case adaptive control causes the flow to select a frequency to lock in to. Additionally, open loop control results in global synchronization via switching between two stable states and closed loop control inhibits the switching phenomena, but rather synchronizes the flow about multiple stable shedding frequencies.

  14. Toxicity of fruit fly baits to beneficial insects in citrus

    Directory of Open Access Journals (Sweden)

    J.P. Michaud

    2003-03-01

    Full Text Available Two fruit fly baits, Nu-Lure®/malathion and GF-120 (Spinosad® were evaluated in the laboratory for non-target impacts on beneficial insects. Nu-Lure/malathion proved attractive and toxic to adults and larvae of the coccinellid species, Curinus coeruleus Mulsant, Cycloneda sanguinea L. and Harmonia axyridis Pallas, a lacewing species, Chrysoperla rufilabris Burmeister. The coccinellids Olla v-nigrum Mulsant, Scymnus sp. and nymphs of the insidious flower bug, Orius insidiosus (Say did not succumb to Nu-Lure baits, even in no-choice situations. Nu-Lure was also attractive and lethal to adults of two aphidophagous flies; Leucopis sp. and the syrphid fly Pseudodorus clavatus (F.. Both Nu-Lure and GF-120 caused significant mortality to the parasitoid wasps, Aphytis melinus De Bach and Lysiphlebus testaceipes Cresson, within 24 h of exposure. However, GF-120 caused no significant mortality to any coccinellid in either choice or no-choice situations, despite considerable consumption of baits. Adults of P. clavatus tended to avoid GF-120, although mortality was significant in no-choice tests. Although larvae and adults of the lacewing C. rufilabris consumed GF-120, mortality was delayed; adults died 48 -96 h post-exposure and those exposed as larvae died two weeks later in the pupal stage. The Nu-Lure bait did not appear palatable to any of the insects, but the high concentration of malathion (195,000 ppm caused rapid mortality to susceptible insects. Nu-Lure bait without malathion also caused significant mortality to flies and lacewings in cage trials. Although GF-120 bait appeared more benign overall, further research efforts are warranted to increase its selectivity for target fly species and reduce its attractiveness to parasitoids and lacewings. I conclude that the Florida "fly free zone" protocol in its current form is not compatible with an IPM approach to commercial citrus production.

  15. Detection of foodborne bacterial pathogens from individual filth flies.

    Science.gov (United States)

    Pava-Ripoll, Monica; Pearson, Rachel E G; Miller, Amy K; Ziobro, George C

    2015-02-13

    There is unanimous consensus that insects are important vectors of foodborne pathogens. However, linking insects as vectors of the pathogen causing a particular foodborne illness outbreak has been challenging. This is because insects are not being aseptically collected as part of an environmental sampling program during foodborne outbreak investigations and because there is not a standardized method to detect foodborne bacteria from individual insects. To take a step towards solving this problem, we adapted a protocol from a commercially available PCR-based system that detects foodborne pathogens from food and environmental samples, to detect foodborne pathogens from individual flies.Using this standardized protocol, we surveyed 100 wild-caught flies for the presence of Cronobacter spp., Salmonella enterica, and Listeria monocytogenes and demonstrated that it was possible to detect and further isolate these pathogens from the body surface and the alimentary canal of a single fly. Twenty-two percent of the alimentary canals and 8% of the body surfaces from collected wild flies were positive for at least one of the three foodborne pathogens. The prevalence of Cronobacter spp. on either body part of the flies was statistically higher (19%) than the prevalence of S. enterica (7%) and L.monocytogenes (4%). No false positives were observed when detecting S. enterica and L. monocytogenes using this PCR-based system because pure bacterial cultures were obtained from all PCR-positive results. However, pure Cronobacter colonies were not obtained from about 50% of PCR-positive samples, suggesting that the PCR-based detection system for this pathogen cross-reacts with other Enterobacteriaceae present among the highly complex microbiota carried by wild flies. The standardized protocol presented here will allow laboratories to detect bacterial foodborne pathogens from aseptically collected insects, thereby giving public health officials another line of evidence to find out how

  16. Zeolite from fly ash: synthesis and characterization

    Indian Academy of Sciences (India)

    Keka Ojha; Narayan C Pradhan; Amar Nath Samanta

    2004-12-01

    Coal fly ash was used to synthesize X-type zeolite by alkali fusion followed by hydrothermal treatment. The synthesized zeolite was characterized using various techniques such as X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, BET method for surface area measurement etc. The synthesis conditions were optimized to obtain highly crystalline zeolite with maximum BET surface area. The maximum surface area of the product was found to be 383 m2/g with high purity. The crystallinity of the prepared zeolite was found to change with fusion temperature and a maximum value was obtained at 823 K. The cost of synthesized zeolite was estimated to be almost one-fifth of that of commercial 13X zeolite available in the market.

  17. Flying High: The Aeromedical Aspects of Marihuana

    Science.gov (United States)

    A summary of the discussions from the Civil Aeromedical Institute Symposium on aeromedical aspects of marihuana is presented. The invited panel...discussed the legal aspects of marihuana use and aviation, the experiences of military aviation, and the acute and chronic effects of the drug. For civil...aviation, the panel proposed a 12-16 hour period between marihuana use and work in aviation, no radical changes in FAA policy towards marihuana use, and additional research on aeromedical aspects of marihuana .

  18. Flying High with the Bird Tetrahedron

    Science.gov (United States)

    Gjovik, Oistein

    2012-01-01

    This article presents an origami activity which can lead to rich tasks in several branches of mathematics. This activity is a good first step for preservice teachers to get to know one another, start talking to one another, and start discussing mathematics. It can also show them how mathematics teaching and learning have changed to a more…

  19. Jetstar Asia’s Growth Flies High

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    For budget travelers,low cost carriers (LCCs)are the best choice.But to the budget travelers in China,there are not many LCC options.According to APGDAT,a data portal for accessing key aviation planning data,from 2006-11,despite a 57-percent growth

  20. Ultrasonic vocalizations emitted by flying squirrels.

    Directory of Open Access Journals (Sweden)

    Meghan N Murrant

    Full Text Available Anecdotal reports of ultrasound use by flying squirrels have existed for decades, yet there has been little detailed analysis of their vocalizations. Here we demonstrate that two species of flying squirrel emit ultrasonic vocalizations. We recorded vocalizations from northern (Glaucomys sabrinus and southern (G. volans flying squirrels calling in both the laboratory and at a field site in central Ontario, Canada. We demonstrate that flying squirrels produce ultrasonic emissions through recorded bursts of broadband noise and time-frequency structured frequency modulated (FM vocalizations, some of which were purely ultrasonic. Squirrels emitted three types of ultrasonic calls in laboratory recordings and one type in the field. The variety of signals that were recorded suggest that flying squirrels may use ultrasonic vocalizations to transfer information. Thus, vocalizations may be an important, although still poorly understood, aspect of flying squirrel social biology.